1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
2 /* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of version 2 of the GNU General Public
6 * License as published by the Free Software Foundation.
8 #ifndef _UAPI__LINUX_BPF_H__
9 #define _UAPI__LINUX_BPF_H__
11 #include <linux/types.h>
12 #include <linux/bpf_common.h>
14 /* Extended instruction set based on top of classic BPF */
16 /* instruction classes */
17 #define BPF_JMP32 0x06 /* jmp mode in word width */
18 #define BPF_ALU64 0x07 /* alu mode in double word width */
21 #define BPF_DW 0x18 /* double word (64-bit) */
22 #define BPF_XADD 0xc0 /* exclusive add */
25 #define BPF_MOV 0xb0 /* mov reg to reg */
26 #define BPF_ARSH 0xc0 /* sign extending arithmetic shift right */
28 /* change endianness of a register */
29 #define BPF_END 0xd0 /* flags for endianness conversion: */
30 #define BPF_TO_LE 0x00 /* convert to little-endian */
31 #define BPF_TO_BE 0x08 /* convert to big-endian */
32 #define BPF_FROM_LE BPF_TO_LE
33 #define BPF_FROM_BE BPF_TO_BE
36 #define BPF_JNE 0x50 /* jump != */
37 #define BPF_JLT 0xa0 /* LT is unsigned, '<' */
38 #define BPF_JLE 0xb0 /* LE is unsigned, '<=' */
39 #define BPF_JSGT 0x60 /* SGT is signed '>', GT in x86 */
40 #define BPF_JSGE 0x70 /* SGE is signed '>=', GE in x86 */
41 #define BPF_JSLT 0xc0 /* SLT is signed, '<' */
42 #define BPF_JSLE 0xd0 /* SLE is signed, '<=' */
43 #define BPF_CALL 0x80 /* function call */
44 #define BPF_EXIT 0x90 /* function return */
46 /* Register numbers */
62 /* BPF has 10 general purpose 64-bit registers and stack frame. */
63 #define MAX_BPF_REG __MAX_BPF_REG
66 __u8 code; /* opcode */
67 __u8 dst_reg:4; /* dest register */
68 __u8 src_reg:4; /* source register */
69 __s16 off; /* signed offset */
70 __s32 imm; /* signed immediate constant */
73 /* Key of an a BPF_MAP_TYPE_LPM_TRIE entry */
74 struct bpf_lpm_trie_key {
75 __u32 prefixlen; /* up to 32 for AF_INET, 128 for AF_INET6 */
76 __u8 data[]; /* Arbitrary size */
79 struct bpf_cgroup_storage_key {
80 __u64 cgroup_inode_id; /* cgroup inode id */
81 __u32 attach_type; /* program attach type */
84 /* BPF syscall commands, see bpf(2) man-page for details. */
99 BPF_PROG_GET_FD_BY_ID,
100 BPF_MAP_GET_FD_BY_ID,
101 BPF_OBJ_GET_INFO_BY_FD,
103 BPF_RAW_TRACEPOINT_OPEN,
105 BPF_BTF_GET_FD_BY_ID,
107 BPF_MAP_LOOKUP_AND_DELETE_ELEM,
110 BPF_MAP_LOOKUP_BATCH,
111 BPF_MAP_LOOKUP_AND_DELETE_BATCH,
112 BPF_MAP_UPDATE_BATCH,
113 BPF_MAP_DELETE_BATCH,
122 BPF_MAP_TYPE_PROG_ARRAY,
123 BPF_MAP_TYPE_PERF_EVENT_ARRAY,
124 BPF_MAP_TYPE_PERCPU_HASH,
125 BPF_MAP_TYPE_PERCPU_ARRAY,
126 BPF_MAP_TYPE_STACK_TRACE,
127 BPF_MAP_TYPE_CGROUP_ARRAY,
128 BPF_MAP_TYPE_LRU_HASH,
129 BPF_MAP_TYPE_LRU_PERCPU_HASH,
130 BPF_MAP_TYPE_LPM_TRIE,
131 BPF_MAP_TYPE_ARRAY_OF_MAPS,
132 BPF_MAP_TYPE_HASH_OF_MAPS,
134 BPF_MAP_TYPE_SOCKMAP,
137 BPF_MAP_TYPE_SOCKHASH,
138 BPF_MAP_TYPE_CGROUP_STORAGE,
139 BPF_MAP_TYPE_REUSEPORT_SOCKARRAY,
140 BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE,
143 BPF_MAP_TYPE_SK_STORAGE,
144 BPF_MAP_TYPE_DEVMAP_HASH,
145 BPF_MAP_TYPE_STRUCT_OPS,
148 /* Note that tracing related programs such as
149 * BPF_PROG_TYPE_{KPROBE,TRACEPOINT,PERF_EVENT,RAW_TRACEPOINT}
150 * are not subject to a stable API since kernel internal data
151 * structures can change from release to release and may
152 * therefore break existing tracing BPF programs. Tracing BPF
153 * programs correspond to /a/ specific kernel which is to be
154 * analyzed, and not /a/ specific kernel /and/ all future ones.
157 BPF_PROG_TYPE_UNSPEC,
158 BPF_PROG_TYPE_SOCKET_FILTER,
159 BPF_PROG_TYPE_KPROBE,
160 BPF_PROG_TYPE_SCHED_CLS,
161 BPF_PROG_TYPE_SCHED_ACT,
162 BPF_PROG_TYPE_TRACEPOINT,
164 BPF_PROG_TYPE_PERF_EVENT,
165 BPF_PROG_TYPE_CGROUP_SKB,
166 BPF_PROG_TYPE_CGROUP_SOCK,
167 BPF_PROG_TYPE_LWT_IN,
168 BPF_PROG_TYPE_LWT_OUT,
169 BPF_PROG_TYPE_LWT_XMIT,
170 BPF_PROG_TYPE_SOCK_OPS,
171 BPF_PROG_TYPE_SK_SKB,
172 BPF_PROG_TYPE_CGROUP_DEVICE,
173 BPF_PROG_TYPE_SK_MSG,
174 BPF_PROG_TYPE_RAW_TRACEPOINT,
175 BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
176 BPF_PROG_TYPE_LWT_SEG6LOCAL,
177 BPF_PROG_TYPE_LIRC_MODE2,
178 BPF_PROG_TYPE_SK_REUSEPORT,
179 BPF_PROG_TYPE_FLOW_DISSECTOR,
180 BPF_PROG_TYPE_CGROUP_SYSCTL,
181 BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE,
182 BPF_PROG_TYPE_CGROUP_SOCKOPT,
183 BPF_PROG_TYPE_TRACING,
184 BPF_PROG_TYPE_STRUCT_OPS,
189 enum bpf_attach_type {
190 BPF_CGROUP_INET_INGRESS,
191 BPF_CGROUP_INET_EGRESS,
192 BPF_CGROUP_INET_SOCK_CREATE,
194 BPF_SK_SKB_STREAM_PARSER,
195 BPF_SK_SKB_STREAM_VERDICT,
198 BPF_CGROUP_INET4_BIND,
199 BPF_CGROUP_INET6_BIND,
200 BPF_CGROUP_INET4_CONNECT,
201 BPF_CGROUP_INET6_CONNECT,
202 BPF_CGROUP_INET4_POST_BIND,
203 BPF_CGROUP_INET6_POST_BIND,
204 BPF_CGROUP_UDP4_SENDMSG,
205 BPF_CGROUP_UDP6_SENDMSG,
209 BPF_CGROUP_UDP4_RECVMSG,
210 BPF_CGROUP_UDP6_RECVMSG,
211 BPF_CGROUP_GETSOCKOPT,
212 BPF_CGROUP_SETSOCKOPT,
218 __MAX_BPF_ATTACH_TYPE
221 #define MAX_BPF_ATTACH_TYPE __MAX_BPF_ATTACH_TYPE
223 /* cgroup-bpf attach flags used in BPF_PROG_ATTACH command
225 * NONE(default): No further bpf programs allowed in the subtree.
227 * BPF_F_ALLOW_OVERRIDE: If a sub-cgroup installs some bpf program,
228 * the program in this cgroup yields to sub-cgroup program.
230 * BPF_F_ALLOW_MULTI: If a sub-cgroup installs some bpf program,
231 * that cgroup program gets run in addition to the program in this cgroup.
233 * Only one program is allowed to be attached to a cgroup with
234 * NONE or BPF_F_ALLOW_OVERRIDE flag.
235 * Attaching another program on top of NONE or BPF_F_ALLOW_OVERRIDE will
236 * release old program and attach the new one. Attach flags has to match.
238 * Multiple programs are allowed to be attached to a cgroup with
239 * BPF_F_ALLOW_MULTI flag. They are executed in FIFO order
240 * (those that were attached first, run first)
241 * The programs of sub-cgroup are executed first, then programs of
242 * this cgroup and then programs of parent cgroup.
243 * When children program makes decision (like picking TCP CA or sock bind)
244 * parent program has a chance to override it.
246 * With BPF_F_ALLOW_MULTI a new program is added to the end of the list of
247 * programs for a cgroup. Though it's possible to replace an old program at
248 * any position by also specifying BPF_F_REPLACE flag and position itself in
249 * replace_bpf_fd attribute. Old program at this position will be released.
251 * A cgroup with MULTI or OVERRIDE flag allows any attach flags in sub-cgroups.
252 * A cgroup with NONE doesn't allow any programs in sub-cgroups.
254 * cgrp1 (MULTI progs A, B) ->
255 * cgrp2 (OVERRIDE prog C) ->
256 * cgrp3 (MULTI prog D) ->
257 * cgrp4 (OVERRIDE prog E) ->
258 * cgrp5 (NONE prog F)
259 * the event in cgrp5 triggers execution of F,D,A,B in that order.
260 * if prog F is detached, the execution is E,D,A,B
261 * if prog F and D are detached, the execution is E,A,B
262 * if prog F, E and D are detached, the execution is C,A,B
264 * All eligible programs are executed regardless of return code from
267 #define BPF_F_ALLOW_OVERRIDE (1U << 0)
268 #define BPF_F_ALLOW_MULTI (1U << 1)
269 #define BPF_F_REPLACE (1U << 2)
271 /* If BPF_F_STRICT_ALIGNMENT is used in BPF_PROG_LOAD command, the
272 * verifier will perform strict alignment checking as if the kernel
273 * has been built with CONFIG_EFFICIENT_UNALIGNED_ACCESS not set,
274 * and NET_IP_ALIGN defined to 2.
276 #define BPF_F_STRICT_ALIGNMENT (1U << 0)
278 /* If BPF_F_ANY_ALIGNMENT is used in BPF_PROF_LOAD command, the
279 * verifier will allow any alignment whatsoever. On platforms
280 * with strict alignment requirements for loads ands stores (such
281 * as sparc and mips) the verifier validates that all loads and
282 * stores provably follow this requirement. This flag turns that
283 * checking and enforcement off.
285 * It is mostly used for testing when we want to validate the
286 * context and memory access aspects of the verifier, but because
287 * of an unaligned access the alignment check would trigger before
288 * the one we are interested in.
290 #define BPF_F_ANY_ALIGNMENT (1U << 1)
292 /* BPF_F_TEST_RND_HI32 is used in BPF_PROG_LOAD command for testing purpose.
293 * Verifier does sub-register def/use analysis and identifies instructions whose
294 * def only matters for low 32-bit, high 32-bit is never referenced later
295 * through implicit zero extension. Therefore verifier notifies JIT back-ends
296 * that it is safe to ignore clearing high 32-bit for these instructions. This
297 * saves some back-ends a lot of code-gen. However such optimization is not
298 * necessary on some arches, for example x86_64, arm64 etc, whose JIT back-ends
299 * hence hasn't used verifier's analysis result. But, we really want to have a
300 * way to be able to verify the correctness of the described optimization on
301 * x86_64 on which testsuites are frequently exercised.
303 * So, this flag is introduced. Once it is set, verifier will randomize high
304 * 32-bit for those instructions who has been identified as safe to ignore them.
305 * Then, if verifier is not doing correct analysis, such randomization will
306 * regress tests to expose bugs.
308 #define BPF_F_TEST_RND_HI32 (1U << 2)
310 /* The verifier internal test flag. Behavior is undefined */
311 #define BPF_F_TEST_STATE_FREQ (1U << 3)
313 /* When BPF ldimm64's insn[0].src_reg != 0 then this can have
316 * insn[0].src_reg: BPF_PSEUDO_MAP_FD BPF_PSEUDO_MAP_VALUE
317 * insn[0].imm: map fd map fd
318 * insn[1].imm: 0 offset into value
321 * ldimm64 rewrite: address of map address of map[0]+offset
322 * verifier type: CONST_PTR_TO_MAP PTR_TO_MAP_VALUE
324 #define BPF_PSEUDO_MAP_FD 1
325 #define BPF_PSEUDO_MAP_VALUE 2
327 /* when bpf_call->src_reg == BPF_PSEUDO_CALL, bpf_call->imm == pc-relative
328 * offset to another bpf function
330 #define BPF_PSEUDO_CALL 1
332 /* flags for BPF_MAP_UPDATE_ELEM command */
334 BPF_ANY = 0, /* create new element or update existing */
335 BPF_NOEXIST = 1, /* create new element if it didn't exist */
336 BPF_EXIST = 2, /* update existing element */
337 BPF_F_LOCK = 4, /* spin_lock-ed map_lookup/map_update */
340 /* flags for BPF_MAP_CREATE command */
342 BPF_F_NO_PREALLOC = (1U << 0),
343 /* Instead of having one common LRU list in the
344 * BPF_MAP_TYPE_LRU_[PERCPU_]HASH map, use a percpu LRU list
345 * which can scale and perform better.
346 * Note, the LRU nodes (including free nodes) cannot be moved
347 * across different LRU lists.
349 BPF_F_NO_COMMON_LRU = (1U << 1),
350 /* Specify numa node during map creation */
351 BPF_F_NUMA_NODE = (1U << 2),
353 /* Flags for accessing BPF object from syscall side. */
354 BPF_F_RDONLY = (1U << 3),
355 BPF_F_WRONLY = (1U << 4),
357 /* Flag for stack_map, store build_id+offset instead of pointer */
358 BPF_F_STACK_BUILD_ID = (1U << 5),
360 /* Zero-initialize hash function seed. This should only be used for testing. */
361 BPF_F_ZERO_SEED = (1U << 6),
363 /* Flags for accessing BPF object from program side. */
364 BPF_F_RDONLY_PROG = (1U << 7),
365 BPF_F_WRONLY_PROG = (1U << 8),
367 /* Clone map from listener for newly accepted socket */
368 BPF_F_CLONE = (1U << 9),
370 /* Enable memory-mapping BPF map */
371 BPF_F_MMAPABLE = (1U << 10),
374 /* Flags for BPF_PROG_QUERY. */
376 /* Query effective (directly attached + inherited from ancestor cgroups)
377 * programs that will be executed for events within a cgroup.
378 * attach_flags with this flag are returned only for directly attached programs.
380 #define BPF_F_QUERY_EFFECTIVE (1U << 0)
382 enum bpf_stack_build_id_status {
383 /* user space need an empty entry to identify end of a trace */
384 BPF_STACK_BUILD_ID_EMPTY = 0,
385 /* with valid build_id and offset */
386 BPF_STACK_BUILD_ID_VALID = 1,
387 /* couldn't get build_id, fallback to ip */
388 BPF_STACK_BUILD_ID_IP = 2,
391 #define BPF_BUILD_ID_SIZE 20
392 struct bpf_stack_build_id {
394 unsigned char build_id[BPF_BUILD_ID_SIZE];
401 #define BPF_OBJ_NAME_LEN 16U
404 struct { /* anonymous struct used by BPF_MAP_CREATE command */
405 __u32 map_type; /* one of enum bpf_map_type */
406 __u32 key_size; /* size of key in bytes */
407 __u32 value_size; /* size of value in bytes */
408 __u32 max_entries; /* max number of entries in a map */
409 __u32 map_flags; /* BPF_MAP_CREATE related
410 * flags defined above.
412 __u32 inner_map_fd; /* fd pointing to the inner map */
413 __u32 numa_node; /* numa node (effective only if
414 * BPF_F_NUMA_NODE is set).
416 char map_name[BPF_OBJ_NAME_LEN];
417 __u32 map_ifindex; /* ifindex of netdev to create on */
418 __u32 btf_fd; /* fd pointing to a BTF type data */
419 __u32 btf_key_type_id; /* BTF type_id of the key */
420 __u32 btf_value_type_id; /* BTF type_id of the value */
421 __u32 btf_vmlinux_value_type_id;/* BTF type_id of a kernel-
422 * struct stored as the
427 struct { /* anonymous struct used by BPF_MAP_*_ELEM commands */
432 __aligned_u64 next_key;
437 struct { /* struct used by BPF_MAP_*_BATCH commands */
438 __aligned_u64 in_batch; /* start batch,
439 * NULL to start from beginning
441 __aligned_u64 out_batch; /* output: next start batch */
443 __aligned_u64 values;
444 __u32 count; /* input/output:
445 * input: # of key/value
447 * output: # of filled elements
454 struct { /* anonymous struct used by BPF_PROG_LOAD command */
455 __u32 prog_type; /* one of enum bpf_prog_type */
458 __aligned_u64 license;
459 __u32 log_level; /* verbosity level of verifier */
460 __u32 log_size; /* size of user buffer */
461 __aligned_u64 log_buf; /* user supplied buffer */
462 __u32 kern_version; /* not used */
464 char prog_name[BPF_OBJ_NAME_LEN];
465 __u32 prog_ifindex; /* ifindex of netdev to prep for */
466 /* For some prog types expected attach type must be known at
467 * load time to verify attach type specific parts of prog
468 * (context accesses, allowed helpers, etc).
470 __u32 expected_attach_type;
471 __u32 prog_btf_fd; /* fd pointing to BTF type data */
472 __u32 func_info_rec_size; /* userspace bpf_func_info size */
473 __aligned_u64 func_info; /* func info */
474 __u32 func_info_cnt; /* number of bpf_func_info records */
475 __u32 line_info_rec_size; /* userspace bpf_line_info size */
476 __aligned_u64 line_info; /* line info */
477 __u32 line_info_cnt; /* number of bpf_line_info records */
478 __u32 attach_btf_id; /* in-kernel BTF type id to attach to */
479 __u32 attach_prog_fd; /* 0 to attach to vmlinux */
482 struct { /* anonymous struct used by BPF_OBJ_* commands */
483 __aligned_u64 pathname;
488 struct { /* anonymous struct used by BPF_PROG_ATTACH/DETACH commands */
489 __u32 target_fd; /* container object to attach to */
490 __u32 attach_bpf_fd; /* eBPF program to attach */
493 __u32 replace_bpf_fd; /* previously attached eBPF
494 * program to replace if
495 * BPF_F_REPLACE is used
499 struct { /* anonymous struct used by BPF_PROG_TEST_RUN command */
502 __u32 data_size_in; /* input: len of data_in */
503 __u32 data_size_out; /* input/output: len of data_out
504 * returns ENOSPC if data_out
507 __aligned_u64 data_in;
508 __aligned_u64 data_out;
511 __u32 ctx_size_in; /* input: len of ctx_in */
512 __u32 ctx_size_out; /* input/output: len of ctx_out
513 * returns ENOSPC if ctx_out
516 __aligned_u64 ctx_in;
517 __aligned_u64 ctx_out;
520 struct { /* anonymous struct used by BPF_*_GET_*_ID */
531 struct { /* anonymous struct used by BPF_OBJ_GET_INFO_BY_FD */
537 struct { /* anonymous struct used by BPF_PROG_QUERY command */
538 __u32 target_fd; /* container object to query */
542 __aligned_u64 prog_ids;
546 struct { /* anonymous struct used by BPF_RAW_TRACEPOINT_OPEN command */
551 struct { /* anonymous struct for BPF_BTF_LOAD */
553 __aligned_u64 btf_log_buf;
560 __u32 pid; /* input: pid */
561 __u32 fd; /* input: fd */
562 __u32 flags; /* input: flags */
563 __u32 buf_len; /* input/output: buf len */
564 __aligned_u64 buf; /* input/output:
565 * tp_name for tracepoint
567 * filename for uprobe
569 __u32 prog_id; /* output: prod_id */
570 __u32 fd_type; /* output: BPF_FD_TYPE_* */
571 __u64 probe_offset; /* output: probe_offset */
572 __u64 probe_addr; /* output: probe_addr */
575 struct { /* struct used by BPF_LINK_CREATE command */
576 __u32 prog_fd; /* eBPF program to attach */
577 __u32 target_fd; /* object to attach to */
578 __u32 attach_type; /* attach type */
579 __u32 flags; /* extra flags */
582 struct { /* struct used by BPF_LINK_UPDATE command */
583 __u32 link_fd; /* link fd */
584 /* new program fd to update link with */
586 __u32 flags; /* extra flags */
587 /* expected link's program fd; is specified only if
588 * BPF_F_REPLACE flag is set in flags */
592 } __attribute__((aligned(8)));
594 /* The description below is an attempt at providing documentation to eBPF
595 * developers about the multiple available eBPF helper functions. It can be
596 * parsed and used to produce a manual page. The workflow is the following,
597 * and requires the rst2man utility:
599 * $ ./scripts/bpf_helpers_doc.py \
600 * --filename include/uapi/linux/bpf.h > /tmp/bpf-helpers.rst
601 * $ rst2man /tmp/bpf-helpers.rst > /tmp/bpf-helpers.7
602 * $ man /tmp/bpf-helpers.7
604 * Note that in order to produce this external documentation, some RST
605 * formatting is used in the descriptions to get "bold" and "italics" in
606 * manual pages. Also note that the few trailing white spaces are
607 * intentional, removing them would break paragraphs for rst2man.
609 * Start of BPF helper function descriptions:
611 * void *bpf_map_lookup_elem(struct bpf_map *map, const void *key)
613 * Perform a lookup in *map* for an entry associated to *key*.
615 * Map value associated to *key*, or **NULL** if no entry was
618 * int bpf_map_update_elem(struct bpf_map *map, const void *key, const void *value, u64 flags)
620 * Add or update the value of the entry associated to *key* in
621 * *map* with *value*. *flags* is one of:
624 * The entry for *key* must not exist in the map.
626 * The entry for *key* must already exist in the map.
628 * No condition on the existence of the entry for *key*.
630 * Flag value **BPF_NOEXIST** cannot be used for maps of types
631 * **BPF_MAP_TYPE_ARRAY** or **BPF_MAP_TYPE_PERCPU_ARRAY** (all
632 * elements always exist), the helper would return an error.
634 * 0 on success, or a negative error in case of failure.
636 * int bpf_map_delete_elem(struct bpf_map *map, const void *key)
638 * Delete entry with *key* from *map*.
640 * 0 on success, or a negative error in case of failure.
642 * int bpf_probe_read(void *dst, u32 size, const void *unsafe_ptr)
644 * For tracing programs, safely attempt to read *size* bytes from
645 * kernel space address *unsafe_ptr* and store the data in *dst*.
647 * Generally, use bpf_probe_read_user() or bpf_probe_read_kernel()
650 * 0 on success, or a negative error in case of failure.
652 * u64 bpf_ktime_get_ns(void)
654 * Return the time elapsed since system boot, in nanoseconds.
658 * int bpf_trace_printk(const char *fmt, u32 fmt_size, ...)
660 * This helper is a "printk()-like" facility for debugging. It
661 * prints a message defined by format *fmt* (of size *fmt_size*)
662 * to file *\/sys/kernel/debug/tracing/trace* from DebugFS, if
663 * available. It can take up to three additional **u64**
664 * arguments (as an eBPF helpers, the total number of arguments is
667 * Each time the helper is called, it appends a line to the trace.
668 * Lines are discarded while *\/sys/kernel/debug/tracing/trace* is
669 * open, use *\/sys/kernel/debug/tracing/trace_pipe* to avoid this.
670 * The format of the trace is customizable, and the exact output
671 * one will get depends on the options set in
672 * *\/sys/kernel/debug/tracing/trace_options* (see also the
673 * *README* file under the same directory). However, it usually
674 * defaults to something like:
678 * telnet-470 [001] .N.. 419421.045894: 0x00000001: <formatted msg>
682 * * ``telnet`` is the name of the current task.
683 * * ``470`` is the PID of the current task.
684 * * ``001`` is the CPU number on which the task is
686 * * In ``.N..``, each character refers to a set of
687 * options (whether irqs are enabled, scheduling
688 * options, whether hard/softirqs are running, level of
689 * preempt_disabled respectively). **N** means that
690 * **TIF_NEED_RESCHED** and **PREEMPT_NEED_RESCHED**
692 * * ``419421.045894`` is a timestamp.
693 * * ``0x00000001`` is a fake value used by BPF for the
694 * instruction pointer register.
695 * * ``<formatted msg>`` is the message formatted with
698 * The conversion specifiers supported by *fmt* are similar, but
699 * more limited than for printk(). They are **%d**, **%i**,
700 * **%u**, **%x**, **%ld**, **%li**, **%lu**, **%lx**, **%lld**,
701 * **%lli**, **%llu**, **%llx**, **%p**, **%s**. No modifier (size
702 * of field, padding with zeroes, etc.) is available, and the
703 * helper will return **-EINVAL** (but print nothing) if it
704 * encounters an unknown specifier.
706 * Also, note that **bpf_trace_printk**\ () is slow, and should
707 * only be used for debugging purposes. For this reason, a notice
708 * bloc (spanning several lines) is printed to kernel logs and
709 * states that the helper should not be used "for production use"
710 * the first time this helper is used (or more precisely, when
711 * **trace_printk**\ () buffers are allocated). For passing values
712 * to user space, perf events should be preferred.
714 * The number of bytes written to the buffer, or a negative error
715 * in case of failure.
717 * u32 bpf_get_prandom_u32(void)
719 * Get a pseudo-random number.
721 * From a security point of view, this helper uses its own
722 * pseudo-random internal state, and cannot be used to infer the
723 * seed of other random functions in the kernel. However, it is
724 * essential to note that the generator used by the helper is not
725 * cryptographically secure.
727 * A random 32-bit unsigned value.
729 * u32 bpf_get_smp_processor_id(void)
731 * Get the SMP (symmetric multiprocessing) processor id. Note that
732 * all programs run with preemption disabled, which means that the
733 * SMP processor id is stable during all the execution of the
736 * The SMP id of the processor running the program.
738 * int bpf_skb_store_bytes(struct sk_buff *skb, u32 offset, const void *from, u32 len, u64 flags)
740 * Store *len* bytes from address *from* into the packet
741 * associated to *skb*, at *offset*. *flags* are a combination of
742 * **BPF_F_RECOMPUTE_CSUM** (automatically recompute the
743 * checksum for the packet after storing the bytes) and
744 * **BPF_F_INVALIDATE_HASH** (set *skb*\ **->hash**, *skb*\
745 * **->swhash** and *skb*\ **->l4hash** to 0).
747 * A call to this helper is susceptible to change the underlying
748 * packet buffer. Therefore, at load time, all checks on pointers
749 * previously done by the verifier are invalidated and must be
750 * performed again, if the helper is used in combination with
751 * direct packet access.
753 * 0 on success, or a negative error in case of failure.
755 * int bpf_l3_csum_replace(struct sk_buff *skb, u32 offset, u64 from, u64 to, u64 size)
757 * Recompute the layer 3 (e.g. IP) checksum for the packet
758 * associated to *skb*. Computation is incremental, so the helper
759 * must know the former value of the header field that was
760 * modified (*from*), the new value of this field (*to*), and the
761 * number of bytes (2 or 4) for this field, stored in *size*.
762 * Alternatively, it is possible to store the difference between
763 * the previous and the new values of the header field in *to*, by
764 * setting *from* and *size* to 0. For both methods, *offset*
765 * indicates the location of the IP checksum within the packet.
767 * This helper works in combination with **bpf_csum_diff**\ (),
768 * which does not update the checksum in-place, but offers more
769 * flexibility and can handle sizes larger than 2 or 4 for the
770 * checksum to update.
772 * A call to this helper is susceptible to change the underlying
773 * packet buffer. Therefore, at load time, all checks on pointers
774 * previously done by the verifier are invalidated and must be
775 * performed again, if the helper is used in combination with
776 * direct packet access.
778 * 0 on success, or a negative error in case of failure.
780 * int bpf_l4_csum_replace(struct sk_buff *skb, u32 offset, u64 from, u64 to, u64 flags)
782 * Recompute the layer 4 (e.g. TCP, UDP or ICMP) checksum for the
783 * packet associated to *skb*. Computation is incremental, so the
784 * helper must know the former value of the header field that was
785 * modified (*from*), the new value of this field (*to*), and the
786 * number of bytes (2 or 4) for this field, stored on the lowest
787 * four bits of *flags*. Alternatively, it is possible to store
788 * the difference between the previous and the new values of the
789 * header field in *to*, by setting *from* and the four lowest
790 * bits of *flags* to 0. For both methods, *offset* indicates the
791 * location of the IP checksum within the packet. In addition to
792 * the size of the field, *flags* can be added (bitwise OR) actual
793 * flags. With **BPF_F_MARK_MANGLED_0**, a null checksum is left
794 * untouched (unless **BPF_F_MARK_ENFORCE** is added as well), and
795 * for updates resulting in a null checksum the value is set to
796 * **CSUM_MANGLED_0** instead. Flag **BPF_F_PSEUDO_HDR** indicates
797 * the checksum is to be computed against a pseudo-header.
799 * This helper works in combination with **bpf_csum_diff**\ (),
800 * which does not update the checksum in-place, but offers more
801 * flexibility and can handle sizes larger than 2 or 4 for the
802 * checksum to update.
804 * A call to this helper is susceptible to change the underlying
805 * packet buffer. Therefore, at load time, all checks on pointers
806 * previously done by the verifier are invalidated and must be
807 * performed again, if the helper is used in combination with
808 * direct packet access.
810 * 0 on success, or a negative error in case of failure.
812 * int bpf_tail_call(void *ctx, struct bpf_map *prog_array_map, u32 index)
814 * This special helper is used to trigger a "tail call", or in
815 * other words, to jump into another eBPF program. The same stack
816 * frame is used (but values on stack and in registers for the
817 * caller are not accessible to the callee). This mechanism allows
818 * for program chaining, either for raising the maximum number of
819 * available eBPF instructions, or to execute given programs in
820 * conditional blocks. For security reasons, there is an upper
821 * limit to the number of successive tail calls that can be
824 * Upon call of this helper, the program attempts to jump into a
825 * program referenced at index *index* in *prog_array_map*, a
826 * special map of type **BPF_MAP_TYPE_PROG_ARRAY**, and passes
827 * *ctx*, a pointer to the context.
829 * If the call succeeds, the kernel immediately runs the first
830 * instruction of the new program. This is not a function call,
831 * and it never returns to the previous program. If the call
832 * fails, then the helper has no effect, and the caller continues
833 * to run its subsequent instructions. A call can fail if the
834 * destination program for the jump does not exist (i.e. *index*
835 * is superior to the number of entries in *prog_array_map*), or
836 * if the maximum number of tail calls has been reached for this
837 * chain of programs. This limit is defined in the kernel by the
838 * macro **MAX_TAIL_CALL_CNT** (not accessible to user space),
839 * which is currently set to 32.
841 * 0 on success, or a negative error in case of failure.
843 * int bpf_clone_redirect(struct sk_buff *skb, u32 ifindex, u64 flags)
845 * Clone and redirect the packet associated to *skb* to another
846 * net device of index *ifindex*. Both ingress and egress
847 * interfaces can be used for redirection. The **BPF_F_INGRESS**
848 * value in *flags* is used to make the distinction (ingress path
849 * is selected if the flag is present, egress path otherwise).
850 * This is the only flag supported for now.
852 * In comparison with **bpf_redirect**\ () helper,
853 * **bpf_clone_redirect**\ () has the associated cost of
854 * duplicating the packet buffer, but this can be executed out of
855 * the eBPF program. Conversely, **bpf_redirect**\ () is more
856 * efficient, but it is handled through an action code where the
857 * redirection happens only after the eBPF program has returned.
859 * A call to this helper is susceptible to change the underlying
860 * packet buffer. Therefore, at load time, all checks on pointers
861 * previously done by the verifier are invalidated and must be
862 * performed again, if the helper is used in combination with
863 * direct packet access.
865 * 0 on success, or a negative error in case of failure.
867 * u64 bpf_get_current_pid_tgid(void)
869 * A 64-bit integer containing the current tgid and pid, and
871 * *current_task*\ **->tgid << 32 \|**
872 * *current_task*\ **->pid**.
874 * u64 bpf_get_current_uid_gid(void)
876 * A 64-bit integer containing the current GID and UID, and
877 * created as such: *current_gid* **<< 32 \|** *current_uid*.
879 * int bpf_get_current_comm(void *buf, u32 size_of_buf)
881 * Copy the **comm** attribute of the current task into *buf* of
882 * *size_of_buf*. The **comm** attribute contains the name of
883 * the executable (excluding the path) for the current task. The
884 * *size_of_buf* must be strictly positive. On success, the
885 * helper makes sure that the *buf* is NUL-terminated. On failure,
886 * it is filled with zeroes.
888 * 0 on success, or a negative error in case of failure.
890 * u32 bpf_get_cgroup_classid(struct sk_buff *skb)
892 * Retrieve the classid for the current task, i.e. for the net_cls
893 * cgroup to which *skb* belongs.
895 * This helper can be used on TC egress path, but not on ingress.
897 * The net_cls cgroup provides an interface to tag network packets
898 * based on a user-provided identifier for all traffic coming from
899 * the tasks belonging to the related cgroup. See also the related
900 * kernel documentation, available from the Linux sources in file
901 * *Documentation/admin-guide/cgroup-v1/net_cls.rst*.
903 * The Linux kernel has two versions for cgroups: there are
904 * cgroups v1 and cgroups v2. Both are available to users, who can
905 * use a mixture of them, but note that the net_cls cgroup is for
906 * cgroup v1 only. This makes it incompatible with BPF programs
907 * run on cgroups, which is a cgroup-v2-only feature (a socket can
908 * only hold data for one version of cgroups at a time).
910 * This helper is only available is the kernel was compiled with
911 * the **CONFIG_CGROUP_NET_CLASSID** configuration option set to
912 * "**y**" or to "**m**".
914 * The classid, or 0 for the default unconfigured classid.
916 * int bpf_skb_vlan_push(struct sk_buff *skb, __be16 vlan_proto, u16 vlan_tci)
918 * Push a *vlan_tci* (VLAN tag control information) of protocol
919 * *vlan_proto* to the packet associated to *skb*, then update
920 * the checksum. Note that if *vlan_proto* is different from
921 * **ETH_P_8021Q** and **ETH_P_8021AD**, it is considered to
922 * be **ETH_P_8021Q**.
924 * A call to this helper is susceptible to change the underlying
925 * packet buffer. Therefore, at load time, all checks on pointers
926 * previously done by the verifier are invalidated and must be
927 * performed again, if the helper is used in combination with
928 * direct packet access.
930 * 0 on success, or a negative error in case of failure.
932 * int bpf_skb_vlan_pop(struct sk_buff *skb)
934 * Pop a VLAN header from the packet associated to *skb*.
936 * A call to this helper is susceptible to change the underlying
937 * packet buffer. Therefore, at load time, all checks on pointers
938 * previously done by the verifier are invalidated and must be
939 * performed again, if the helper is used in combination with
940 * direct packet access.
942 * 0 on success, or a negative error in case of failure.
944 * int bpf_skb_get_tunnel_key(struct sk_buff *skb, struct bpf_tunnel_key *key, u32 size, u64 flags)
946 * Get tunnel metadata. This helper takes a pointer *key* to an
947 * empty **struct bpf_tunnel_key** of **size**, that will be
948 * filled with tunnel metadata for the packet associated to *skb*.
949 * The *flags* can be set to **BPF_F_TUNINFO_IPV6**, which
950 * indicates that the tunnel is based on IPv6 protocol instead of
953 * The **struct bpf_tunnel_key** is an object that generalizes the
954 * principal parameters used by various tunneling protocols into a
955 * single struct. This way, it can be used to easily make a
956 * decision based on the contents of the encapsulation header,
957 * "summarized" in this struct. In particular, it holds the IP
958 * address of the remote end (IPv4 or IPv6, depending on the case)
959 * in *key*\ **->remote_ipv4** or *key*\ **->remote_ipv6**. Also,
960 * this struct exposes the *key*\ **->tunnel_id**, which is
961 * generally mapped to a VNI (Virtual Network Identifier), making
962 * it programmable together with the **bpf_skb_set_tunnel_key**\
965 * Let's imagine that the following code is part of a program
966 * attached to the TC ingress interface, on one end of a GRE
967 * tunnel, and is supposed to filter out all messages coming from
968 * remote ends with IPv4 address other than 10.0.0.1:
973 * struct bpf_tunnel_key key = {};
975 * ret = bpf_skb_get_tunnel_key(skb, &key, sizeof(key), 0);
977 * return TC_ACT_SHOT; // drop packet
979 * if (key.remote_ipv4 != 0x0a000001)
980 * return TC_ACT_SHOT; // drop packet
982 * return TC_ACT_OK; // accept packet
984 * This interface can also be used with all encapsulation devices
985 * that can operate in "collect metadata" mode: instead of having
986 * one network device per specific configuration, the "collect
987 * metadata" mode only requires a single device where the
988 * configuration can be extracted from this helper.
990 * This can be used together with various tunnels such as VXLan,
991 * Geneve, GRE or IP in IP (IPIP).
993 * 0 on success, or a negative error in case of failure.
995 * int bpf_skb_set_tunnel_key(struct sk_buff *skb, struct bpf_tunnel_key *key, u32 size, u64 flags)
997 * Populate tunnel metadata for packet associated to *skb.* The
998 * tunnel metadata is set to the contents of *key*, of *size*. The
999 * *flags* can be set to a combination of the following values:
1001 * **BPF_F_TUNINFO_IPV6**
1002 * Indicate that the tunnel is based on IPv6 protocol
1004 * **BPF_F_ZERO_CSUM_TX**
1005 * For IPv4 packets, add a flag to tunnel metadata
1006 * indicating that checksum computation should be skipped
1007 * and checksum set to zeroes.
1008 * **BPF_F_DONT_FRAGMENT**
1009 * Add a flag to tunnel metadata indicating that the
1010 * packet should not be fragmented.
1011 * **BPF_F_SEQ_NUMBER**
1012 * Add a flag to tunnel metadata indicating that a
1013 * sequence number should be added to tunnel header before
1014 * sending the packet. This flag was added for GRE
1015 * encapsulation, but might be used with other protocols
1016 * as well in the future.
1018 * Here is a typical usage on the transmit path:
1022 * struct bpf_tunnel_key key;
1024 * bpf_skb_set_tunnel_key(skb, &key, sizeof(key), 0);
1025 * bpf_clone_redirect(skb, vxlan_dev_ifindex, 0);
1027 * See also the description of the **bpf_skb_get_tunnel_key**\ ()
1028 * helper for additional information.
1030 * 0 on success, or a negative error in case of failure.
1032 * u64 bpf_perf_event_read(struct bpf_map *map, u64 flags)
1034 * Read the value of a perf event counter. This helper relies on a
1035 * *map* of type **BPF_MAP_TYPE_PERF_EVENT_ARRAY**. The nature of
1036 * the perf event counter is selected when *map* is updated with
1037 * perf event file descriptors. The *map* is an array whose size
1038 * is the number of available CPUs, and each cell contains a value
1039 * relative to one CPU. The value to retrieve is indicated by
1040 * *flags*, that contains the index of the CPU to look up, masked
1041 * with **BPF_F_INDEX_MASK**. Alternatively, *flags* can be set to
1042 * **BPF_F_CURRENT_CPU** to indicate that the value for the
1043 * current CPU should be retrieved.
1045 * Note that before Linux 4.13, only hardware perf event can be
1048 * Also, be aware that the newer helper
1049 * **bpf_perf_event_read_value**\ () is recommended over
1050 * **bpf_perf_event_read**\ () in general. The latter has some ABI
1051 * quirks where error and counter value are used as a return code
1052 * (which is wrong to do since ranges may overlap). This issue is
1053 * fixed with **bpf_perf_event_read_value**\ (), which at the same
1054 * time provides more features over the **bpf_perf_event_read**\
1055 * () interface. Please refer to the description of
1056 * **bpf_perf_event_read_value**\ () for details.
1058 * The value of the perf event counter read from the map, or a
1059 * negative error code in case of failure.
1061 * int bpf_redirect(u32 ifindex, u64 flags)
1063 * Redirect the packet to another net device of index *ifindex*.
1064 * This helper is somewhat similar to **bpf_clone_redirect**\
1065 * (), except that the packet is not cloned, which provides
1066 * increased performance.
1068 * Except for XDP, both ingress and egress interfaces can be used
1069 * for redirection. The **BPF_F_INGRESS** value in *flags* is used
1070 * to make the distinction (ingress path is selected if the flag
1071 * is present, egress path otherwise). Currently, XDP only
1072 * supports redirection to the egress interface, and accepts no
1075 * The same effect can also be attained with the more generic
1076 * **bpf_redirect_map**\ (), which uses a BPF map to store the
1077 * redirect target instead of providing it directly to the helper.
1079 * For XDP, the helper returns **XDP_REDIRECT** on success or
1080 * **XDP_ABORTED** on error. For other program types, the values
1081 * are **TC_ACT_REDIRECT** on success or **TC_ACT_SHOT** on
1084 * u32 bpf_get_route_realm(struct sk_buff *skb)
1086 * Retrieve the realm or the route, that is to say the
1087 * **tclassid** field of the destination for the *skb*. The
1088 * indentifier retrieved is a user-provided tag, similar to the
1089 * one used with the net_cls cgroup (see description for
1090 * **bpf_get_cgroup_classid**\ () helper), but here this tag is
1091 * held by a route (a destination entry), not by a task.
1093 * Retrieving this identifier works with the clsact TC egress hook
1094 * (see also **tc-bpf(8)**), or alternatively on conventional
1095 * classful egress qdiscs, but not on TC ingress path. In case of
1096 * clsact TC egress hook, this has the advantage that, internally,
1097 * the destination entry has not been dropped yet in the transmit
1098 * path. Therefore, the destination entry does not need to be
1099 * artificially held via **netif_keep_dst**\ () for a classful
1100 * qdisc until the *skb* is freed.
1102 * This helper is available only if the kernel was compiled with
1103 * **CONFIG_IP_ROUTE_CLASSID** configuration option.
1105 * The realm of the route for the packet associated to *skb*, or 0
1106 * if none was found.
1108 * int bpf_perf_event_output(void *ctx, struct bpf_map *map, u64 flags, void *data, u64 size)
1110 * Write raw *data* blob into a special BPF perf event held by
1111 * *map* of type **BPF_MAP_TYPE_PERF_EVENT_ARRAY**. This perf
1112 * event must have the following attributes: **PERF_SAMPLE_RAW**
1113 * as **sample_type**, **PERF_TYPE_SOFTWARE** as **type**, and
1114 * **PERF_COUNT_SW_BPF_OUTPUT** as **config**.
1116 * The *flags* are used to indicate the index in *map* for which
1117 * the value must be put, masked with **BPF_F_INDEX_MASK**.
1118 * Alternatively, *flags* can be set to **BPF_F_CURRENT_CPU**
1119 * to indicate that the index of the current CPU core should be
1122 * The value to write, of *size*, is passed through eBPF stack and
1123 * pointed by *data*.
1125 * The context of the program *ctx* needs also be passed to the
1128 * On user space, a program willing to read the values needs to
1129 * call **perf_event_open**\ () on the perf event (either for
1130 * one or for all CPUs) and to store the file descriptor into the
1131 * *map*. This must be done before the eBPF program can send data
1132 * into it. An example is available in file
1133 * *samples/bpf/trace_output_user.c* in the Linux kernel source
1134 * tree (the eBPF program counterpart is in
1135 * *samples/bpf/trace_output_kern.c*).
1137 * **bpf_perf_event_output**\ () achieves better performance
1138 * than **bpf_trace_printk**\ () for sharing data with user
1139 * space, and is much better suitable for streaming data from eBPF
1142 * Note that this helper is not restricted to tracing use cases
1143 * and can be used with programs attached to TC or XDP as well,
1144 * where it allows for passing data to user space listeners. Data
1147 * * Only custom structs,
1148 * * Only the packet payload, or
1149 * * A combination of both.
1151 * 0 on success, or a negative error in case of failure.
1153 * int bpf_skb_load_bytes(const void *skb, u32 offset, void *to, u32 len)
1155 * This helper was provided as an easy way to load data from a
1156 * packet. It can be used to load *len* bytes from *offset* from
1157 * the packet associated to *skb*, into the buffer pointed by
1160 * Since Linux 4.7, usage of this helper has mostly been replaced
1161 * by "direct packet access", enabling packet data to be
1162 * manipulated with *skb*\ **->data** and *skb*\ **->data_end**
1163 * pointing respectively to the first byte of packet data and to
1164 * the byte after the last byte of packet data. However, it
1165 * remains useful if one wishes to read large quantities of data
1166 * at once from a packet into the eBPF stack.
1168 * 0 on success, or a negative error in case of failure.
1170 * int bpf_get_stackid(void *ctx, struct bpf_map *map, u64 flags)
1172 * Walk a user or a kernel stack and return its id. To achieve
1173 * this, the helper needs *ctx*, which is a pointer to the context
1174 * on which the tracing program is executed, and a pointer to a
1175 * *map* of type **BPF_MAP_TYPE_STACK_TRACE**.
1177 * The last argument, *flags*, holds the number of stack frames to
1178 * skip (from 0 to 255), masked with
1179 * **BPF_F_SKIP_FIELD_MASK**. The next bits can be used to set
1180 * a combination of the following flags:
1182 * **BPF_F_USER_STACK**
1183 * Collect a user space stack instead of a kernel stack.
1184 * **BPF_F_FAST_STACK_CMP**
1185 * Compare stacks by hash only.
1186 * **BPF_F_REUSE_STACKID**
1187 * If two different stacks hash into the same *stackid*,
1188 * discard the old one.
1190 * The stack id retrieved is a 32 bit long integer handle which
1191 * can be further combined with other data (including other stack
1192 * ids) and used as a key into maps. This can be useful for
1193 * generating a variety of graphs (such as flame graphs or off-cpu
1196 * For walking a stack, this helper is an improvement over
1197 * **bpf_probe_read**\ (), which can be used with unrolled loops
1198 * but is not efficient and consumes a lot of eBPF instructions.
1199 * Instead, **bpf_get_stackid**\ () can collect up to
1200 * **PERF_MAX_STACK_DEPTH** both kernel and user frames. Note that
1201 * this limit can be controlled with the **sysctl** program, and
1202 * that it should be manually increased in order to profile long
1203 * user stacks (such as stacks for Java programs). To do so, use:
1207 * # sysctl kernel.perf_event_max_stack=<new value>
1209 * The positive or null stack id on success, or a negative error
1210 * in case of failure.
1212 * s64 bpf_csum_diff(__be32 *from, u32 from_size, __be32 *to, u32 to_size, __wsum seed)
1214 * Compute a checksum difference, from the raw buffer pointed by
1215 * *from*, of length *from_size* (that must be a multiple of 4),
1216 * towards the raw buffer pointed by *to*, of size *to_size*
1217 * (same remark). An optional *seed* can be added to the value
1218 * (this can be cascaded, the seed may come from a previous call
1221 * This is flexible enough to be used in several ways:
1223 * * With *from_size* == 0, *to_size* > 0 and *seed* set to
1224 * checksum, it can be used when pushing new data.
1225 * * With *from_size* > 0, *to_size* == 0 and *seed* set to
1226 * checksum, it can be used when removing data from a packet.
1227 * * With *from_size* > 0, *to_size* > 0 and *seed* set to 0, it
1228 * can be used to compute a diff. Note that *from_size* and
1229 * *to_size* do not need to be equal.
1231 * This helper can be used in combination with
1232 * **bpf_l3_csum_replace**\ () and **bpf_l4_csum_replace**\ (), to
1233 * which one can feed in the difference computed with
1234 * **bpf_csum_diff**\ ().
1236 * The checksum result, or a negative error code in case of
1239 * int bpf_skb_get_tunnel_opt(struct sk_buff *skb, void *opt, u32 size)
1241 * Retrieve tunnel options metadata for the packet associated to
1242 * *skb*, and store the raw tunnel option data to the buffer *opt*
1245 * This helper can be used with encapsulation devices that can
1246 * operate in "collect metadata" mode (please refer to the related
1247 * note in the description of **bpf_skb_get_tunnel_key**\ () for
1248 * more details). A particular example where this can be used is
1249 * in combination with the Geneve encapsulation protocol, where it
1250 * allows for pushing (with **bpf_skb_get_tunnel_opt**\ () helper)
1251 * and retrieving arbitrary TLVs (Type-Length-Value headers) from
1252 * the eBPF program. This allows for full customization of these
1255 * The size of the option data retrieved.
1257 * int bpf_skb_set_tunnel_opt(struct sk_buff *skb, void *opt, u32 size)
1259 * Set tunnel options metadata for the packet associated to *skb*
1260 * to the option data contained in the raw buffer *opt* of *size*.
1262 * See also the description of the **bpf_skb_get_tunnel_opt**\ ()
1263 * helper for additional information.
1265 * 0 on success, or a negative error in case of failure.
1267 * int bpf_skb_change_proto(struct sk_buff *skb, __be16 proto, u64 flags)
1269 * Change the protocol of the *skb* to *proto*. Currently
1270 * supported are transition from IPv4 to IPv6, and from IPv6 to
1271 * IPv4. The helper takes care of the groundwork for the
1272 * transition, including resizing the socket buffer. The eBPF
1273 * program is expected to fill the new headers, if any, via
1274 * **skb_store_bytes**\ () and to recompute the checksums with
1275 * **bpf_l3_csum_replace**\ () and **bpf_l4_csum_replace**\
1276 * (). The main case for this helper is to perform NAT64
1277 * operations out of an eBPF program.
1279 * Internally, the GSO type is marked as dodgy so that headers are
1280 * checked and segments are recalculated by the GSO/GRO engine.
1281 * The size for GSO target is adapted as well.
1283 * All values for *flags* are reserved for future usage, and must
1286 * A call to this helper is susceptible to change the underlying
1287 * packet buffer. Therefore, at load time, all checks on pointers
1288 * previously done by the verifier are invalidated and must be
1289 * performed again, if the helper is used in combination with
1290 * direct packet access.
1292 * 0 on success, or a negative error in case of failure.
1294 * int bpf_skb_change_type(struct sk_buff *skb, u32 type)
1296 * Change the packet type for the packet associated to *skb*. This
1297 * comes down to setting *skb*\ **->pkt_type** to *type*, except
1298 * the eBPF program does not have a write access to *skb*\
1299 * **->pkt_type** beside this helper. Using a helper here allows
1300 * for graceful handling of errors.
1302 * The major use case is to change incoming *skb*s to
1303 * **PACKET_HOST** in a programmatic way instead of having to
1304 * recirculate via **redirect**\ (..., **BPF_F_INGRESS**), for
1307 * Note that *type* only allows certain values. At this time, they
1312 * **PACKET_BROADCAST**
1313 * Send packet to all.
1314 * **PACKET_MULTICAST**
1315 * Send packet to group.
1316 * **PACKET_OTHERHOST**
1317 * Send packet to someone else.
1319 * 0 on success, or a negative error in case of failure.
1321 * int bpf_skb_under_cgroup(struct sk_buff *skb, struct bpf_map *map, u32 index)
1323 * Check whether *skb* is a descendant of the cgroup2 held by
1324 * *map* of type **BPF_MAP_TYPE_CGROUP_ARRAY**, at *index*.
1326 * The return value depends on the result of the test, and can be:
1328 * * 0, if the *skb* failed the cgroup2 descendant test.
1329 * * 1, if the *skb* succeeded the cgroup2 descendant test.
1330 * * A negative error code, if an error occurred.
1332 * u32 bpf_get_hash_recalc(struct sk_buff *skb)
1334 * Retrieve the hash of the packet, *skb*\ **->hash**. If it is
1335 * not set, in particular if the hash was cleared due to mangling,
1336 * recompute this hash. Later accesses to the hash can be done
1337 * directly with *skb*\ **->hash**.
1339 * Calling **bpf_set_hash_invalid**\ (), changing a packet
1340 * prototype with **bpf_skb_change_proto**\ (), or calling
1341 * **bpf_skb_store_bytes**\ () with the
1342 * **BPF_F_INVALIDATE_HASH** are actions susceptible to clear
1343 * the hash and to trigger a new computation for the next call to
1344 * **bpf_get_hash_recalc**\ ().
1348 * u64 bpf_get_current_task(void)
1350 * A pointer to the current task struct.
1352 * int bpf_probe_write_user(void *dst, const void *src, u32 len)
1354 * Attempt in a safe way to write *len* bytes from the buffer
1355 * *src* to *dst* in memory. It only works for threads that are in
1356 * user context, and *dst* must be a valid user space address.
1358 * This helper should not be used to implement any kind of
1359 * security mechanism because of TOC-TOU attacks, but rather to
1360 * debug, divert, and manipulate execution of semi-cooperative
1363 * Keep in mind that this feature is meant for experiments, and it
1364 * has a risk of crashing the system and running programs.
1365 * Therefore, when an eBPF program using this helper is attached,
1366 * a warning including PID and process name is printed to kernel
1369 * 0 on success, or a negative error in case of failure.
1371 * int bpf_current_task_under_cgroup(struct bpf_map *map, u32 index)
1373 * Check whether the probe is being run is the context of a given
1374 * subset of the cgroup2 hierarchy. The cgroup2 to test is held by
1375 * *map* of type **BPF_MAP_TYPE_CGROUP_ARRAY**, at *index*.
1377 * The return value depends on the result of the test, and can be:
1379 * * 0, if the *skb* task belongs to the cgroup2.
1380 * * 1, if the *skb* task does not belong to the cgroup2.
1381 * * A negative error code, if an error occurred.
1383 * int bpf_skb_change_tail(struct sk_buff *skb, u32 len, u64 flags)
1385 * Resize (trim or grow) the packet associated to *skb* to the
1386 * new *len*. The *flags* are reserved for future usage, and must
1389 * The basic idea is that the helper performs the needed work to
1390 * change the size of the packet, then the eBPF program rewrites
1391 * the rest via helpers like **bpf_skb_store_bytes**\ (),
1392 * **bpf_l3_csum_replace**\ (), **bpf_l3_csum_replace**\ ()
1393 * and others. This helper is a slow path utility intended for
1394 * replies with control messages. And because it is targeted for
1395 * slow path, the helper itself can afford to be slow: it
1396 * implicitly linearizes, unclones and drops offloads from the
1399 * A call to this helper is susceptible to change the underlying
1400 * packet buffer. Therefore, at load time, all checks on pointers
1401 * previously done by the verifier are invalidated and must be
1402 * performed again, if the helper is used in combination with
1403 * direct packet access.
1405 * 0 on success, or a negative error in case of failure.
1407 * int bpf_skb_pull_data(struct sk_buff *skb, u32 len)
1409 * Pull in non-linear data in case the *skb* is non-linear and not
1410 * all of *len* are part of the linear section. Make *len* bytes
1411 * from *skb* readable and writable. If a zero value is passed for
1412 * *len*, then the whole length of the *skb* is pulled.
1414 * This helper is only needed for reading and writing with direct
1417 * For direct packet access, testing that offsets to access
1418 * are within packet boundaries (test on *skb*\ **->data_end**) is
1419 * susceptible to fail if offsets are invalid, or if the requested
1420 * data is in non-linear parts of the *skb*. On failure the
1421 * program can just bail out, or in the case of a non-linear
1422 * buffer, use a helper to make the data available. The
1423 * **bpf_skb_load_bytes**\ () helper is a first solution to access
1424 * the data. Another one consists in using **bpf_skb_pull_data**
1425 * to pull in once the non-linear parts, then retesting and
1426 * eventually access the data.
1428 * At the same time, this also makes sure the *skb* is uncloned,
1429 * which is a necessary condition for direct write. As this needs
1430 * to be an invariant for the write part only, the verifier
1431 * detects writes and adds a prologue that is calling
1432 * **bpf_skb_pull_data()** to effectively unclone the *skb* from
1433 * the very beginning in case it is indeed cloned.
1435 * A call to this helper is susceptible to change the underlying
1436 * packet buffer. Therefore, at load time, all checks on pointers
1437 * previously done by the verifier are invalidated and must be
1438 * performed again, if the helper is used in combination with
1439 * direct packet access.
1441 * 0 on success, or a negative error in case of failure.
1443 * s64 bpf_csum_update(struct sk_buff *skb, __wsum csum)
1445 * Add the checksum *csum* into *skb*\ **->csum** in case the
1446 * driver has supplied a checksum for the entire packet into that
1447 * field. Return an error otherwise. This helper is intended to be
1448 * used in combination with **bpf_csum_diff**\ (), in particular
1449 * when the checksum needs to be updated after data has been
1450 * written into the packet through direct packet access.
1452 * The checksum on success, or a negative error code in case of
1455 * void bpf_set_hash_invalid(struct sk_buff *skb)
1457 * Invalidate the current *skb*\ **->hash**. It can be used after
1458 * mangling on headers through direct packet access, in order to
1459 * indicate that the hash is outdated and to trigger a
1460 * recalculation the next time the kernel tries to access this
1461 * hash or when the **bpf_get_hash_recalc**\ () helper is called.
1463 * int bpf_get_numa_node_id(void)
1465 * Return the id of the current NUMA node. The primary use case
1466 * for this helper is the selection of sockets for the local NUMA
1467 * node, when the program is attached to sockets using the
1468 * **SO_ATTACH_REUSEPORT_EBPF** option (see also **socket(7)**),
1469 * but the helper is also available to other eBPF program types,
1470 * similarly to **bpf_get_smp_processor_id**\ ().
1472 * The id of current NUMA node.
1474 * int bpf_skb_change_head(struct sk_buff *skb, u32 len, u64 flags)
1476 * Grows headroom of packet associated to *skb* and adjusts the
1477 * offset of the MAC header accordingly, adding *len* bytes of
1478 * space. It automatically extends and reallocates memory as
1481 * This helper can be used on a layer 3 *skb* to push a MAC header
1482 * for redirection into a layer 2 device.
1484 * All values for *flags* are reserved for future usage, and must
1487 * A call to this helper is susceptible to change the underlying
1488 * packet buffer. Therefore, at load time, all checks on pointers
1489 * previously done by the verifier are invalidated and must be
1490 * performed again, if the helper is used in combination with
1491 * direct packet access.
1493 * 0 on success, or a negative error in case of failure.
1495 * int bpf_xdp_adjust_head(struct xdp_buff *xdp_md, int delta)
1497 * Adjust (move) *xdp_md*\ **->data** by *delta* bytes. Note that
1498 * it is possible to use a negative value for *delta*. This helper
1499 * can be used to prepare the packet for pushing or popping
1502 * A call to this helper is susceptible to change the underlying
1503 * packet buffer. Therefore, at load time, all checks on pointers
1504 * previously done by the verifier are invalidated and must be
1505 * performed again, if the helper is used in combination with
1506 * direct packet access.
1508 * 0 on success, or a negative error in case of failure.
1510 * int bpf_probe_read_str(void *dst, u32 size, const void *unsafe_ptr)
1512 * Copy a NUL terminated string from an unsafe kernel address
1513 * *unsafe_ptr* to *dst*. See bpf_probe_read_kernel_str() for
1516 * Generally, use bpf_probe_read_user_str() or bpf_probe_read_kernel_str()
1519 * On success, the strictly positive length of the string,
1520 * including the trailing NUL character. On error, a negative
1523 * u64 bpf_get_socket_cookie(struct sk_buff *skb)
1525 * If the **struct sk_buff** pointed by *skb* has a known socket,
1526 * retrieve the cookie (generated by the kernel) of this socket.
1527 * If no cookie has been set yet, generate a new cookie. Once
1528 * generated, the socket cookie remains stable for the life of the
1529 * socket. This helper can be useful for monitoring per socket
1530 * networking traffic statistics as it provides a global socket
1531 * identifier that can be assumed unique.
1533 * A 8-byte long non-decreasing number on success, or 0 if the
1534 * socket field is missing inside *skb*.
1536 * u64 bpf_get_socket_cookie(struct bpf_sock_addr *ctx)
1538 * Equivalent to bpf_get_socket_cookie() helper that accepts
1539 * *skb*, but gets socket from **struct bpf_sock_addr** context.
1541 * A 8-byte long non-decreasing number.
1543 * u64 bpf_get_socket_cookie(struct bpf_sock_ops *ctx)
1545 * Equivalent to bpf_get_socket_cookie() helper that accepts
1546 * *skb*, but gets socket from **struct bpf_sock_ops** context.
1548 * A 8-byte long non-decreasing number.
1550 * u32 bpf_get_socket_uid(struct sk_buff *skb)
1552 * The owner UID of the socket associated to *skb*. If the socket
1553 * is **NULL**, or if it is not a full socket (i.e. if it is a
1554 * time-wait or a request socket instead), **overflowuid** value
1555 * is returned (note that **overflowuid** might also be the actual
1556 * UID value for the socket).
1558 * u32 bpf_set_hash(struct sk_buff *skb, u32 hash)
1560 * Set the full hash for *skb* (set the field *skb*\ **->hash**)
1565 * int bpf_setsockopt(struct bpf_sock_ops *bpf_socket, int level, int optname, void *optval, int optlen)
1567 * Emulate a call to **setsockopt()** on the socket associated to
1568 * *bpf_socket*, which must be a full socket. The *level* at
1569 * which the option resides and the name *optname* of the option
1570 * must be specified, see **setsockopt(2)** for more information.
1571 * The option value of length *optlen* is pointed by *optval*.
1573 * This helper actually implements a subset of **setsockopt()**.
1574 * It supports the following *level*\ s:
1576 * * **SOL_SOCKET**, which supports the following *optname*\ s:
1577 * **SO_RCVBUF**, **SO_SNDBUF**, **SO_MAX_PACING_RATE**,
1578 * **SO_PRIORITY**, **SO_RCVLOWAT**, **SO_MARK**.
1579 * * **IPPROTO_TCP**, which supports the following *optname*\ s:
1580 * **TCP_CONGESTION**, **TCP_BPF_IW**,
1581 * **TCP_BPF_SNDCWND_CLAMP**.
1582 * * **IPPROTO_IP**, which supports *optname* **IP_TOS**.
1583 * * **IPPROTO_IPV6**, which supports *optname* **IPV6_TCLASS**.
1585 * 0 on success, or a negative error in case of failure.
1587 * int bpf_skb_adjust_room(struct sk_buff *skb, s32 len_diff, u32 mode, u64 flags)
1589 * Grow or shrink the room for data in the packet associated to
1590 * *skb* by *len_diff*, and according to the selected *mode*.
1592 * There are two supported modes at this time:
1594 * * **BPF_ADJ_ROOM_MAC**: Adjust room at the mac layer
1595 * (room space is added or removed below the layer 2 header).
1597 * * **BPF_ADJ_ROOM_NET**: Adjust room at the network layer
1598 * (room space is added or removed below the layer 3 header).
1600 * The following flags are supported at this time:
1602 * * **BPF_F_ADJ_ROOM_FIXED_GSO**: Do not adjust gso_size.
1603 * Adjusting mss in this way is not allowed for datagrams.
1605 * * **BPF_F_ADJ_ROOM_ENCAP_L3_IPV4**,
1606 * **BPF_F_ADJ_ROOM_ENCAP_L3_IPV6**:
1607 * Any new space is reserved to hold a tunnel header.
1608 * Configure skb offsets and other fields accordingly.
1610 * * **BPF_F_ADJ_ROOM_ENCAP_L4_GRE**,
1611 * **BPF_F_ADJ_ROOM_ENCAP_L4_UDP**:
1612 * Use with ENCAP_L3 flags to further specify the tunnel type.
1614 * * **BPF_F_ADJ_ROOM_ENCAP_L2**\ (*len*):
1615 * Use with ENCAP_L3/L4 flags to further specify the tunnel
1616 * type; *len* is the length of the inner MAC header.
1618 * A call to this helper is susceptible to change the underlying
1619 * packet buffer. Therefore, at load time, all checks on pointers
1620 * previously done by the verifier are invalidated and must be
1621 * performed again, if the helper is used in combination with
1622 * direct packet access.
1624 * 0 on success, or a negative error in case of failure.
1626 * int bpf_redirect_map(struct bpf_map *map, u32 key, u64 flags)
1628 * Redirect the packet to the endpoint referenced by *map* at
1629 * index *key*. Depending on its type, this *map* can contain
1630 * references to net devices (for forwarding packets through other
1631 * ports), or to CPUs (for redirecting XDP frames to another CPU;
1632 * but this is only implemented for native XDP (with driver
1633 * support) as of this writing).
1635 * The lower two bits of *flags* are used as the return code if
1636 * the map lookup fails. This is so that the return value can be
1637 * one of the XDP program return codes up to XDP_TX, as chosen by
1638 * the caller. Any higher bits in the *flags* argument must be
1641 * See also bpf_redirect(), which only supports redirecting to an
1642 * ifindex, but doesn't require a map to do so.
1644 * **XDP_REDIRECT** on success, or the value of the two lower bits
1645 * of the *flags* argument on error.
1647 * int bpf_sk_redirect_map(struct sk_buff *skb, struct bpf_map *map, u32 key, u64 flags)
1649 * Redirect the packet to the socket referenced by *map* (of type
1650 * **BPF_MAP_TYPE_SOCKMAP**) at index *key*. Both ingress and
1651 * egress interfaces can be used for redirection. The
1652 * **BPF_F_INGRESS** value in *flags* is used to make the
1653 * distinction (ingress path is selected if the flag is present,
1654 * egress path otherwise). This is the only flag supported for now.
1656 * **SK_PASS** on success, or **SK_DROP** on error.
1658 * int bpf_sock_map_update(struct bpf_sock_ops *skops, struct bpf_map *map, void *key, u64 flags)
1660 * Add an entry to, or update a *map* referencing sockets. The
1661 * *skops* is used as a new value for the entry associated to
1662 * *key*. *flags* is one of:
1665 * The entry for *key* must not exist in the map.
1667 * The entry for *key* must already exist in the map.
1669 * No condition on the existence of the entry for *key*.
1671 * If the *map* has eBPF programs (parser and verdict), those will
1672 * be inherited by the socket being added. If the socket is
1673 * already attached to eBPF programs, this results in an error.
1675 * 0 on success, or a negative error in case of failure.
1677 * int bpf_xdp_adjust_meta(struct xdp_buff *xdp_md, int delta)
1679 * Adjust the address pointed by *xdp_md*\ **->data_meta** by
1680 * *delta* (which can be positive or negative). Note that this
1681 * operation modifies the address stored in *xdp_md*\ **->data**,
1682 * so the latter must be loaded only after the helper has been
1685 * The use of *xdp_md*\ **->data_meta** is optional and programs
1686 * are not required to use it. The rationale is that when the
1687 * packet is processed with XDP (e.g. as DoS filter), it is
1688 * possible to push further meta data along with it before passing
1689 * to the stack, and to give the guarantee that an ingress eBPF
1690 * program attached as a TC classifier on the same device can pick
1691 * this up for further post-processing. Since TC works with socket
1692 * buffers, it remains possible to set from XDP the **mark** or
1693 * **priority** pointers, or other pointers for the socket buffer.
1694 * Having this scratch space generic and programmable allows for
1695 * more flexibility as the user is free to store whatever meta
1698 * A call to this helper is susceptible to change the underlying
1699 * packet buffer. Therefore, at load time, all checks on pointers
1700 * previously done by the verifier are invalidated and must be
1701 * performed again, if the helper is used in combination with
1702 * direct packet access.
1704 * 0 on success, or a negative error in case of failure.
1706 * int bpf_perf_event_read_value(struct bpf_map *map, u64 flags, struct bpf_perf_event_value *buf, u32 buf_size)
1708 * Read the value of a perf event counter, and store it into *buf*
1709 * of size *buf_size*. This helper relies on a *map* of type
1710 * **BPF_MAP_TYPE_PERF_EVENT_ARRAY**. The nature of the perf event
1711 * counter is selected when *map* is updated with perf event file
1712 * descriptors. The *map* is an array whose size is the number of
1713 * available CPUs, and each cell contains a value relative to one
1714 * CPU. The value to retrieve is indicated by *flags*, that
1715 * contains the index of the CPU to look up, masked with
1716 * **BPF_F_INDEX_MASK**. Alternatively, *flags* can be set to
1717 * **BPF_F_CURRENT_CPU** to indicate that the value for the
1718 * current CPU should be retrieved.
1720 * This helper behaves in a way close to
1721 * **bpf_perf_event_read**\ () helper, save that instead of
1722 * just returning the value observed, it fills the *buf*
1723 * structure. This allows for additional data to be retrieved: in
1724 * particular, the enabled and running times (in *buf*\
1725 * **->enabled** and *buf*\ **->running**, respectively) are
1726 * copied. In general, **bpf_perf_event_read_value**\ () is
1727 * recommended over **bpf_perf_event_read**\ (), which has some
1728 * ABI issues and provides fewer functionalities.
1730 * These values are interesting, because hardware PMU (Performance
1731 * Monitoring Unit) counters are limited resources. When there are
1732 * more PMU based perf events opened than available counters,
1733 * kernel will multiplex these events so each event gets certain
1734 * percentage (but not all) of the PMU time. In case that
1735 * multiplexing happens, the number of samples or counter value
1736 * will not reflect the case compared to when no multiplexing
1737 * occurs. This makes comparison between different runs difficult.
1738 * Typically, the counter value should be normalized before
1739 * comparing to other experiments. The usual normalization is done
1744 * normalized_counter = counter * t_enabled / t_running
1746 * Where t_enabled is the time enabled for event and t_running is
1747 * the time running for event since last normalization. The
1748 * enabled and running times are accumulated since the perf event
1749 * open. To achieve scaling factor between two invocations of an
1750 * eBPF program, users can can use CPU id as the key (which is
1751 * typical for perf array usage model) to remember the previous
1752 * value and do the calculation inside the eBPF program.
1754 * 0 on success, or a negative error in case of failure.
1756 * int bpf_perf_prog_read_value(struct bpf_perf_event_data *ctx, struct bpf_perf_event_value *buf, u32 buf_size)
1758 * For en eBPF program attached to a perf event, retrieve the
1759 * value of the event counter associated to *ctx* and store it in
1760 * the structure pointed by *buf* and of size *buf_size*. Enabled
1761 * and running times are also stored in the structure (see
1762 * description of helper **bpf_perf_event_read_value**\ () for
1765 * 0 on success, or a negative error in case of failure.
1767 * int bpf_getsockopt(struct bpf_sock_ops *bpf_socket, int level, int optname, void *optval, int optlen)
1769 * Emulate a call to **getsockopt()** on the socket associated to
1770 * *bpf_socket*, which must be a full socket. The *level* at
1771 * which the option resides and the name *optname* of the option
1772 * must be specified, see **getsockopt(2)** for more information.
1773 * The retrieved value is stored in the structure pointed by
1774 * *opval* and of length *optlen*.
1776 * This helper actually implements a subset of **getsockopt()**.
1777 * It supports the following *level*\ s:
1779 * * **IPPROTO_TCP**, which supports *optname*
1780 * **TCP_CONGESTION**.
1781 * * **IPPROTO_IP**, which supports *optname* **IP_TOS**.
1782 * * **IPPROTO_IPV6**, which supports *optname* **IPV6_TCLASS**.
1784 * 0 on success, or a negative error in case of failure.
1786 * int bpf_override_return(struct pt_regs *regs, u64 rc)
1788 * Used for error injection, this helper uses kprobes to override
1789 * the return value of the probed function, and to set it to *rc*.
1790 * The first argument is the context *regs* on which the kprobe
1793 * This helper works by setting setting the PC (program counter)
1794 * to an override function which is run in place of the original
1795 * probed function. This means the probed function is not run at
1796 * all. The replacement function just returns with the required
1799 * This helper has security implications, and thus is subject to
1800 * restrictions. It is only available if the kernel was compiled
1801 * with the **CONFIG_BPF_KPROBE_OVERRIDE** configuration
1802 * option, and in this case it only works on functions tagged with
1803 * **ALLOW_ERROR_INJECTION** in the kernel code.
1805 * Also, the helper is only available for the architectures having
1806 * the CONFIG_FUNCTION_ERROR_INJECTION option. As of this writing,
1807 * x86 architecture is the only one to support this feature.
1811 * int bpf_sock_ops_cb_flags_set(struct bpf_sock_ops *bpf_sock, int argval)
1813 * Attempt to set the value of the **bpf_sock_ops_cb_flags** field
1814 * for the full TCP socket associated to *bpf_sock_ops* to
1817 * The primary use of this field is to determine if there should
1818 * be calls to eBPF programs of type
1819 * **BPF_PROG_TYPE_SOCK_OPS** at various points in the TCP
1820 * code. A program of the same type can change its value, per
1821 * connection and as necessary, when the connection is
1822 * established. This field is directly accessible for reading, but
1823 * this helper must be used for updates in order to return an
1824 * error if an eBPF program tries to set a callback that is not
1825 * supported in the current kernel.
1827 * *argval* is a flag array which can combine these flags:
1829 * * **BPF_SOCK_OPS_RTO_CB_FLAG** (retransmission time out)
1830 * * **BPF_SOCK_OPS_RETRANS_CB_FLAG** (retransmission)
1831 * * **BPF_SOCK_OPS_STATE_CB_FLAG** (TCP state change)
1832 * * **BPF_SOCK_OPS_RTT_CB_FLAG** (every RTT)
1834 * Therefore, this function can be used to clear a callback flag by
1835 * setting the appropriate bit to zero. e.g. to disable the RTO
1838 * **bpf_sock_ops_cb_flags_set(bpf_sock,**
1839 * **bpf_sock->bpf_sock_ops_cb_flags & ~BPF_SOCK_OPS_RTO_CB_FLAG)**
1841 * Here are some examples of where one could call such eBPF
1845 * * When a packet is retransmitted.
1846 * * When the connection terminates.
1847 * * When a packet is sent.
1848 * * When a packet is received.
1850 * Code **-EINVAL** if the socket is not a full TCP socket;
1851 * otherwise, a positive number containing the bits that could not
1852 * be set is returned (which comes down to 0 if all bits were set
1855 * int bpf_msg_redirect_map(struct sk_msg_buff *msg, struct bpf_map *map, u32 key, u64 flags)
1857 * This helper is used in programs implementing policies at the
1858 * socket level. If the message *msg* is allowed to pass (i.e. if
1859 * the verdict eBPF program returns **SK_PASS**), redirect it to
1860 * the socket referenced by *map* (of type
1861 * **BPF_MAP_TYPE_SOCKMAP**) at index *key*. Both ingress and
1862 * egress interfaces can be used for redirection. The
1863 * **BPF_F_INGRESS** value in *flags* is used to make the
1864 * distinction (ingress path is selected if the flag is present,
1865 * egress path otherwise). This is the only flag supported for now.
1867 * **SK_PASS** on success, or **SK_DROP** on error.
1869 * int bpf_msg_apply_bytes(struct sk_msg_buff *msg, u32 bytes)
1871 * For socket policies, apply the verdict of the eBPF program to
1872 * the next *bytes* (number of bytes) of message *msg*.
1874 * For example, this helper can be used in the following cases:
1876 * * A single **sendmsg**\ () or **sendfile**\ () system call
1877 * contains multiple logical messages that the eBPF program is
1878 * supposed to read and for which it should apply a verdict.
1879 * * An eBPF program only cares to read the first *bytes* of a
1880 * *msg*. If the message has a large payload, then setting up
1881 * and calling the eBPF program repeatedly for all bytes, even
1882 * though the verdict is already known, would create unnecessary
1885 * When called from within an eBPF program, the helper sets a
1886 * counter internal to the BPF infrastructure, that is used to
1887 * apply the last verdict to the next *bytes*. If *bytes* is
1888 * smaller than the current data being processed from a
1889 * **sendmsg**\ () or **sendfile**\ () system call, the first
1890 * *bytes* will be sent and the eBPF program will be re-run with
1891 * the pointer for start of data pointing to byte number *bytes*
1892 * **+ 1**. If *bytes* is larger than the current data being
1893 * processed, then the eBPF verdict will be applied to multiple
1894 * **sendmsg**\ () or **sendfile**\ () calls until *bytes* are
1897 * Note that if a socket closes with the internal counter holding
1898 * a non-zero value, this is not a problem because data is not
1899 * being buffered for *bytes* and is sent as it is received.
1903 * int bpf_msg_cork_bytes(struct sk_msg_buff *msg, u32 bytes)
1905 * For socket policies, prevent the execution of the verdict eBPF
1906 * program for message *msg* until *bytes* (byte number) have been
1909 * This can be used when one needs a specific number of bytes
1910 * before a verdict can be assigned, even if the data spans
1911 * multiple **sendmsg**\ () or **sendfile**\ () calls. The extreme
1912 * case would be a user calling **sendmsg**\ () repeatedly with
1913 * 1-byte long message segments. Obviously, this is bad for
1914 * performance, but it is still valid. If the eBPF program needs
1915 * *bytes* bytes to validate a header, this helper can be used to
1916 * prevent the eBPF program to be called again until *bytes* have
1921 * int bpf_msg_pull_data(struct sk_msg_buff *msg, u32 start, u32 end, u64 flags)
1923 * For socket policies, pull in non-linear data from user space
1924 * for *msg* and set pointers *msg*\ **->data** and *msg*\
1925 * **->data_end** to *start* and *end* bytes offsets into *msg*,
1928 * If a program of type **BPF_PROG_TYPE_SK_MSG** is run on a
1929 * *msg* it can only parse data that the (**data**, **data_end**)
1930 * pointers have already consumed. For **sendmsg**\ () hooks this
1931 * is likely the first scatterlist element. But for calls relying
1932 * on the **sendpage** handler (e.g. **sendfile**\ ()) this will
1933 * be the range (**0**, **0**) because the data is shared with
1934 * user space and by default the objective is to avoid allowing
1935 * user space to modify data while (or after) eBPF verdict is
1936 * being decided. This helper can be used to pull in data and to
1937 * set the start and end pointer to given values. Data will be
1938 * copied if necessary (i.e. if data was not linear and if start
1939 * and end pointers do not point to the same chunk).
1941 * A call to this helper is susceptible to change the underlying
1942 * packet buffer. Therefore, at load time, all checks on pointers
1943 * previously done by the verifier are invalidated and must be
1944 * performed again, if the helper is used in combination with
1945 * direct packet access.
1947 * All values for *flags* are reserved for future usage, and must
1950 * 0 on success, or a negative error in case of failure.
1952 * int bpf_bind(struct bpf_sock_addr *ctx, struct sockaddr *addr, int addr_len)
1954 * Bind the socket associated to *ctx* to the address pointed by
1955 * *addr*, of length *addr_len*. This allows for making outgoing
1956 * connection from the desired IP address, which can be useful for
1957 * example when all processes inside a cgroup should use one
1958 * single IP address on a host that has multiple IP configured.
1960 * This helper works for IPv4 and IPv6, TCP and UDP sockets. The
1961 * domain (*addr*\ **->sa_family**) must be **AF_INET** (or
1962 * **AF_INET6**). Looking for a free port to bind to can be
1963 * expensive, therefore binding to port is not permitted by the
1964 * helper: *addr*\ **->sin_port** (or **sin6_port**, respectively)
1965 * must be set to zero.
1967 * 0 on success, or a negative error in case of failure.
1969 * int bpf_xdp_adjust_tail(struct xdp_buff *xdp_md, int delta)
1971 * Adjust (move) *xdp_md*\ **->data_end** by *delta* bytes. It is
1972 * only possible to shrink the packet as of this writing,
1973 * therefore *delta* must be a negative integer.
1975 * A call to this helper is susceptible to change the underlying
1976 * packet buffer. Therefore, at load time, all checks on pointers
1977 * previously done by the verifier are invalidated and must be
1978 * performed again, if the helper is used in combination with
1979 * direct packet access.
1981 * 0 on success, or a negative error in case of failure.
1983 * int bpf_skb_get_xfrm_state(struct sk_buff *skb, u32 index, struct bpf_xfrm_state *xfrm_state, u32 size, u64 flags)
1985 * Retrieve the XFRM state (IP transform framework, see also
1986 * **ip-xfrm(8)**) at *index* in XFRM "security path" for *skb*.
1988 * The retrieved value is stored in the **struct bpf_xfrm_state**
1989 * pointed by *xfrm_state* and of length *size*.
1991 * All values for *flags* are reserved for future usage, and must
1994 * This helper is available only if the kernel was compiled with
1995 * **CONFIG_XFRM** configuration option.
1997 * 0 on success, or a negative error in case of failure.
1999 * int bpf_get_stack(void *ctx, void *buf, u32 size, u64 flags)
2001 * Return a user or a kernel stack in bpf program provided buffer.
2002 * To achieve this, the helper needs *ctx*, which is a pointer
2003 * to the context on which the tracing program is executed.
2004 * To store the stacktrace, the bpf program provides *buf* with
2005 * a nonnegative *size*.
2007 * The last argument, *flags*, holds the number of stack frames to
2008 * skip (from 0 to 255), masked with
2009 * **BPF_F_SKIP_FIELD_MASK**. The next bits can be used to set
2010 * the following flags:
2012 * **BPF_F_USER_STACK**
2013 * Collect a user space stack instead of a kernel stack.
2014 * **BPF_F_USER_BUILD_ID**
2015 * Collect buildid+offset instead of ips for user stack,
2016 * only valid if **BPF_F_USER_STACK** is also specified.
2018 * **bpf_get_stack**\ () can collect up to
2019 * **PERF_MAX_STACK_DEPTH** both kernel and user frames, subject
2020 * to sufficient large buffer size. Note that
2021 * this limit can be controlled with the **sysctl** program, and
2022 * that it should be manually increased in order to profile long
2023 * user stacks (such as stacks for Java programs). To do so, use:
2027 * # sysctl kernel.perf_event_max_stack=<new value>
2029 * A non-negative value equal to or less than *size* on success,
2030 * or a negative error in case of failure.
2032 * int bpf_skb_load_bytes_relative(const void *skb, u32 offset, void *to, u32 len, u32 start_header)
2034 * This helper is similar to **bpf_skb_load_bytes**\ () in that
2035 * it provides an easy way to load *len* bytes from *offset*
2036 * from the packet associated to *skb*, into the buffer pointed
2037 * by *to*. The difference to **bpf_skb_load_bytes**\ () is that
2038 * a fifth argument *start_header* exists in order to select a
2039 * base offset to start from. *start_header* can be one of:
2041 * **BPF_HDR_START_MAC**
2042 * Base offset to load data from is *skb*'s mac header.
2043 * **BPF_HDR_START_NET**
2044 * Base offset to load data from is *skb*'s network header.
2046 * In general, "direct packet access" is the preferred method to
2047 * access packet data, however, this helper is in particular useful
2048 * in socket filters where *skb*\ **->data** does not always point
2049 * to the start of the mac header and where "direct packet access"
2052 * 0 on success, or a negative error in case of failure.
2054 * int bpf_fib_lookup(void *ctx, struct bpf_fib_lookup *params, int plen, u32 flags)
2056 * Do FIB lookup in kernel tables using parameters in *params*.
2057 * If lookup is successful and result shows packet is to be
2058 * forwarded, the neighbor tables are searched for the nexthop.
2059 * If successful (ie., FIB lookup shows forwarding and nexthop
2060 * is resolved), the nexthop address is returned in ipv4_dst
2061 * or ipv6_dst based on family, smac is set to mac address of
2062 * egress device, dmac is set to nexthop mac address, rt_metric
2063 * is set to metric from route (IPv4/IPv6 only), and ifindex
2064 * is set to the device index of the nexthop from the FIB lookup.
2066 * *plen* argument is the size of the passed in struct.
2067 * *flags* argument can be a combination of one or more of the
2070 * **BPF_FIB_LOOKUP_DIRECT**
2071 * Do a direct table lookup vs full lookup using FIB
2073 * **BPF_FIB_LOOKUP_OUTPUT**
2074 * Perform lookup from an egress perspective (default is
2077 * *ctx* is either **struct xdp_md** for XDP programs or
2078 * **struct sk_buff** tc cls_act programs.
2080 * * < 0 if any input argument is invalid
2081 * * 0 on success (packet is forwarded, nexthop neighbor exists)
2082 * * > 0 one of **BPF_FIB_LKUP_RET_** codes explaining why the
2083 * packet is not forwarded or needs assist from full stack
2085 * int bpf_sock_hash_update(struct bpf_sock_ops *skops, struct bpf_map *map, void *key, u64 flags)
2087 * Add an entry to, or update a sockhash *map* referencing sockets.
2088 * The *skops* is used as a new value for the entry associated to
2089 * *key*. *flags* is one of:
2092 * The entry for *key* must not exist in the map.
2094 * The entry for *key* must already exist in the map.
2096 * No condition on the existence of the entry for *key*.
2098 * If the *map* has eBPF programs (parser and verdict), those will
2099 * be inherited by the socket being added. If the socket is
2100 * already attached to eBPF programs, this results in an error.
2102 * 0 on success, or a negative error in case of failure.
2104 * int bpf_msg_redirect_hash(struct sk_msg_buff *msg, struct bpf_map *map, void *key, u64 flags)
2106 * This helper is used in programs implementing policies at the
2107 * socket level. If the message *msg* is allowed to pass (i.e. if
2108 * the verdict eBPF program returns **SK_PASS**), redirect it to
2109 * the socket referenced by *map* (of type
2110 * **BPF_MAP_TYPE_SOCKHASH**) using hash *key*. Both ingress and
2111 * egress interfaces can be used for redirection. The
2112 * **BPF_F_INGRESS** value in *flags* is used to make the
2113 * distinction (ingress path is selected if the flag is present,
2114 * egress path otherwise). This is the only flag supported for now.
2116 * **SK_PASS** on success, or **SK_DROP** on error.
2118 * int bpf_sk_redirect_hash(struct sk_buff *skb, struct bpf_map *map, void *key, u64 flags)
2120 * This helper is used in programs implementing policies at the
2121 * skb socket level. If the sk_buff *skb* is allowed to pass (i.e.
2122 * if the verdeict eBPF program returns **SK_PASS**), redirect it
2123 * to the socket referenced by *map* (of type
2124 * **BPF_MAP_TYPE_SOCKHASH**) using hash *key*. Both ingress and
2125 * egress interfaces can be used for redirection. The
2126 * **BPF_F_INGRESS** value in *flags* is used to make the
2127 * distinction (ingress path is selected if the flag is present,
2128 * egress otherwise). This is the only flag supported for now.
2130 * **SK_PASS** on success, or **SK_DROP** on error.
2132 * int bpf_lwt_push_encap(struct sk_buff *skb, u32 type, void *hdr, u32 len)
2134 * Encapsulate the packet associated to *skb* within a Layer 3
2135 * protocol header. This header is provided in the buffer at
2136 * address *hdr*, with *len* its size in bytes. *type* indicates
2137 * the protocol of the header and can be one of:
2139 * **BPF_LWT_ENCAP_SEG6**
2140 * IPv6 encapsulation with Segment Routing Header
2141 * (**struct ipv6_sr_hdr**). *hdr* only contains the SRH,
2142 * the IPv6 header is computed by the kernel.
2143 * **BPF_LWT_ENCAP_SEG6_INLINE**
2144 * Only works if *skb* contains an IPv6 packet. Insert a
2145 * Segment Routing Header (**struct ipv6_sr_hdr**) inside
2147 * **BPF_LWT_ENCAP_IP**
2148 * IP encapsulation (GRE/GUE/IPIP/etc). The outer header
2149 * must be IPv4 or IPv6, followed by zero or more
2150 * additional headers, up to **LWT_BPF_MAX_HEADROOM**
2151 * total bytes in all prepended headers. Please note that
2152 * if **skb_is_gso**\ (*skb*) is true, no more than two
2153 * headers can be prepended, and the inner header, if
2154 * present, should be either GRE or UDP/GUE.
2156 * **BPF_LWT_ENCAP_SEG6**\ \* types can be called by BPF programs
2157 * of type **BPF_PROG_TYPE_LWT_IN**; **BPF_LWT_ENCAP_IP** type can
2158 * be called by bpf programs of types **BPF_PROG_TYPE_LWT_IN** and
2159 * **BPF_PROG_TYPE_LWT_XMIT**.
2161 * A call to this helper is susceptible to change the underlying
2162 * packet buffer. Therefore, at load time, all checks on pointers
2163 * previously done by the verifier are invalidated and must be
2164 * performed again, if the helper is used in combination with
2165 * direct packet access.
2167 * 0 on success, or a negative error in case of failure.
2169 * int bpf_lwt_seg6_store_bytes(struct sk_buff *skb, u32 offset, const void *from, u32 len)
2171 * Store *len* bytes from address *from* into the packet
2172 * associated to *skb*, at *offset*. Only the flags, tag and TLVs
2173 * inside the outermost IPv6 Segment Routing Header can be
2174 * modified through this helper.
2176 * A call to this helper is susceptible to change the underlying
2177 * packet buffer. Therefore, at load time, all checks on pointers
2178 * previously done by the verifier are invalidated and must be
2179 * performed again, if the helper is used in combination with
2180 * direct packet access.
2182 * 0 on success, or a negative error in case of failure.
2184 * int bpf_lwt_seg6_adjust_srh(struct sk_buff *skb, u32 offset, s32 delta)
2186 * Adjust the size allocated to TLVs in the outermost IPv6
2187 * Segment Routing Header contained in the packet associated to
2188 * *skb*, at position *offset* by *delta* bytes. Only offsets
2189 * after the segments are accepted. *delta* can be as well
2190 * positive (growing) as negative (shrinking).
2192 * A call to this helper is susceptible to change the underlying
2193 * packet buffer. Therefore, at load time, all checks on pointers
2194 * previously done by the verifier are invalidated and must be
2195 * performed again, if the helper is used in combination with
2196 * direct packet access.
2198 * 0 on success, or a negative error in case of failure.
2200 * int bpf_lwt_seg6_action(struct sk_buff *skb, u32 action, void *param, u32 param_len)
2202 * Apply an IPv6 Segment Routing action of type *action* to the
2203 * packet associated to *skb*. Each action takes a parameter
2204 * contained at address *param*, and of length *param_len* bytes.
2205 * *action* can be one of:
2207 * **SEG6_LOCAL_ACTION_END_X**
2208 * End.X action: Endpoint with Layer-3 cross-connect.
2209 * Type of *param*: **struct in6_addr**.
2210 * **SEG6_LOCAL_ACTION_END_T**
2211 * End.T action: Endpoint with specific IPv6 table lookup.
2212 * Type of *param*: **int**.
2213 * **SEG6_LOCAL_ACTION_END_B6**
2214 * End.B6 action: Endpoint bound to an SRv6 policy.
2215 * Type of *param*: **struct ipv6_sr_hdr**.
2216 * **SEG6_LOCAL_ACTION_END_B6_ENCAP**
2217 * End.B6.Encap action: Endpoint bound to an SRv6
2218 * encapsulation policy.
2219 * Type of *param*: **struct ipv6_sr_hdr**.
2221 * A call to this helper is susceptible to change the underlying
2222 * packet buffer. Therefore, at load time, all checks on pointers
2223 * previously done by the verifier are invalidated and must be
2224 * performed again, if the helper is used in combination with
2225 * direct packet access.
2227 * 0 on success, or a negative error in case of failure.
2229 * int bpf_rc_repeat(void *ctx)
2231 * This helper is used in programs implementing IR decoding, to
2232 * report a successfully decoded repeat key message. This delays
2233 * the generation of a key up event for previously generated
2236 * Some IR protocols like NEC have a special IR message for
2237 * repeating last button, for when a button is held down.
2239 * The *ctx* should point to the lirc sample as passed into
2242 * This helper is only available is the kernel was compiled with
2243 * the **CONFIG_BPF_LIRC_MODE2** configuration option set to
2248 * int bpf_rc_keydown(void *ctx, u32 protocol, u64 scancode, u32 toggle)
2250 * This helper is used in programs implementing IR decoding, to
2251 * report a successfully decoded key press with *scancode*,
2252 * *toggle* value in the given *protocol*. The scancode will be
2253 * translated to a keycode using the rc keymap, and reported as
2254 * an input key down event. After a period a key up event is
2255 * generated. This period can be extended by calling either
2256 * **bpf_rc_keydown**\ () again with the same values, or calling
2257 * **bpf_rc_repeat**\ ().
2259 * Some protocols include a toggle bit, in case the button was
2260 * released and pressed again between consecutive scancodes.
2262 * The *ctx* should point to the lirc sample as passed into
2265 * The *protocol* is the decoded protocol number (see
2266 * **enum rc_proto** for some predefined values).
2268 * This helper is only available is the kernel was compiled with
2269 * the **CONFIG_BPF_LIRC_MODE2** configuration option set to
2274 * u64 bpf_skb_cgroup_id(struct sk_buff *skb)
2276 * Return the cgroup v2 id of the socket associated with the *skb*.
2277 * This is roughly similar to the **bpf_get_cgroup_classid**\ ()
2278 * helper for cgroup v1 by providing a tag resp. identifier that
2279 * can be matched on or used for map lookups e.g. to implement
2280 * policy. The cgroup v2 id of a given path in the hierarchy is
2281 * exposed in user space through the f_handle API in order to get
2282 * to the same 64-bit id.
2284 * This helper can be used on TC egress path, but not on ingress,
2285 * and is available only if the kernel was compiled with the
2286 * **CONFIG_SOCK_CGROUP_DATA** configuration option.
2288 * The id is returned or 0 in case the id could not be retrieved.
2290 * u64 bpf_get_current_cgroup_id(void)
2292 * A 64-bit integer containing the current cgroup id based
2293 * on the cgroup within which the current task is running.
2295 * void *bpf_get_local_storage(void *map, u64 flags)
2297 * Get the pointer to the local storage area.
2298 * The type and the size of the local storage is defined
2299 * by the *map* argument.
2300 * The *flags* meaning is specific for each map type,
2301 * and has to be 0 for cgroup local storage.
2303 * Depending on the BPF program type, a local storage area
2304 * can be shared between multiple instances of the BPF program,
2305 * running simultaneously.
2307 * A user should care about the synchronization by himself.
2308 * For example, by using the **BPF_STX_XADD** instruction to alter
2311 * A pointer to the local storage area.
2313 * int bpf_sk_select_reuseport(struct sk_reuseport_md *reuse, struct bpf_map *map, void *key, u64 flags)
2315 * Select a **SO_REUSEPORT** socket from a
2316 * **BPF_MAP_TYPE_REUSEPORT_ARRAY** *map*.
2317 * It checks the selected socket is matching the incoming
2318 * request in the socket buffer.
2320 * 0 on success, or a negative error in case of failure.
2322 * u64 bpf_skb_ancestor_cgroup_id(struct sk_buff *skb, int ancestor_level)
2324 * Return id of cgroup v2 that is ancestor of cgroup associated
2325 * with the *skb* at the *ancestor_level*. The root cgroup is at
2326 * *ancestor_level* zero and each step down the hierarchy
2327 * increments the level. If *ancestor_level* == level of cgroup
2328 * associated with *skb*, then return value will be same as that
2329 * of **bpf_skb_cgroup_id**\ ().
2331 * The helper is useful to implement policies based on cgroups
2332 * that are upper in hierarchy than immediate cgroup associated
2335 * The format of returned id and helper limitations are same as in
2336 * **bpf_skb_cgroup_id**\ ().
2338 * The id is returned or 0 in case the id could not be retrieved.
2340 * struct bpf_sock *bpf_sk_lookup_tcp(void *ctx, struct bpf_sock_tuple *tuple, u32 tuple_size, u64 netns, u64 flags)
2342 * Look for TCP socket matching *tuple*, optionally in a child
2343 * network namespace *netns*. The return value must be checked,
2344 * and if non-**NULL**, released via **bpf_sk_release**\ ().
2346 * The *ctx* should point to the context of the program, such as
2347 * the skb or socket (depending on the hook in use). This is used
2348 * to determine the base network namespace for the lookup.
2350 * *tuple_size* must be one of:
2352 * **sizeof**\ (*tuple*\ **->ipv4**)
2353 * Look for an IPv4 socket.
2354 * **sizeof**\ (*tuple*\ **->ipv6**)
2355 * Look for an IPv6 socket.
2357 * If the *netns* is a negative signed 32-bit integer, then the
2358 * socket lookup table in the netns associated with the *ctx* will
2359 * will be used. For the TC hooks, this is the netns of the device
2360 * in the skb. For socket hooks, this is the netns of the socket.
2361 * If *netns* is any other signed 32-bit value greater than or
2362 * equal to zero then it specifies the ID of the netns relative to
2363 * the netns associated with the *ctx*. *netns* values beyond the
2364 * range of 32-bit integers are reserved for future use.
2366 * All values for *flags* are reserved for future usage, and must
2369 * This helper is available only if the kernel was compiled with
2370 * **CONFIG_NET** configuration option.
2372 * Pointer to **struct bpf_sock**, or **NULL** in case of failure.
2373 * For sockets with reuseport option, the **struct bpf_sock**
2374 * result is from *reuse*\ **->socks**\ [] using the hash of the
2377 * struct bpf_sock *bpf_sk_lookup_udp(void *ctx, struct bpf_sock_tuple *tuple, u32 tuple_size, u64 netns, u64 flags)
2379 * Look for UDP socket matching *tuple*, optionally in a child
2380 * network namespace *netns*. The return value must be checked,
2381 * and if non-**NULL**, released via **bpf_sk_release**\ ().
2383 * The *ctx* should point to the context of the program, such as
2384 * the skb or socket (depending on the hook in use). This is used
2385 * to determine the base network namespace for the lookup.
2387 * *tuple_size* must be one of:
2389 * **sizeof**\ (*tuple*\ **->ipv4**)
2390 * Look for an IPv4 socket.
2391 * **sizeof**\ (*tuple*\ **->ipv6**)
2392 * Look for an IPv6 socket.
2394 * If the *netns* is a negative signed 32-bit integer, then the
2395 * socket lookup table in the netns associated with the *ctx* will
2396 * will be used. For the TC hooks, this is the netns of the device
2397 * in the skb. For socket hooks, this is the netns of the socket.
2398 * If *netns* is any other signed 32-bit value greater than or
2399 * equal to zero then it specifies the ID of the netns relative to
2400 * the netns associated with the *ctx*. *netns* values beyond the
2401 * range of 32-bit integers are reserved for future use.
2403 * All values for *flags* are reserved for future usage, and must
2406 * This helper is available only if the kernel was compiled with
2407 * **CONFIG_NET** configuration option.
2409 * Pointer to **struct bpf_sock**, or **NULL** in case of failure.
2410 * For sockets with reuseport option, the **struct bpf_sock**
2411 * result is from *reuse*\ **->socks**\ [] using the hash of the
2414 * int bpf_sk_release(struct bpf_sock *sock)
2416 * Release the reference held by *sock*. *sock* must be a
2417 * non-**NULL** pointer that was returned from
2418 * **bpf_sk_lookup_xxx**\ ().
2420 * 0 on success, or a negative error in case of failure.
2422 * int bpf_map_push_elem(struct bpf_map *map, const void *value, u64 flags)
2424 * Push an element *value* in *map*. *flags* is one of:
2427 * If the queue/stack is full, the oldest element is
2428 * removed to make room for this.
2430 * 0 on success, or a negative error in case of failure.
2432 * int bpf_map_pop_elem(struct bpf_map *map, void *value)
2434 * Pop an element from *map*.
2436 * 0 on success, or a negative error in case of failure.
2438 * int bpf_map_peek_elem(struct bpf_map *map, void *value)
2440 * Get an element from *map* without removing it.
2442 * 0 on success, or a negative error in case of failure.
2444 * int bpf_msg_push_data(struct sk_msg_buff *msg, u32 start, u32 len, u64 flags)
2446 * For socket policies, insert *len* bytes into *msg* at offset
2449 * If a program of type **BPF_PROG_TYPE_SK_MSG** is run on a
2450 * *msg* it may want to insert metadata or options into the *msg*.
2451 * This can later be read and used by any of the lower layer BPF
2454 * This helper may fail if under memory pressure (a malloc
2455 * fails) in these cases BPF programs will get an appropriate
2456 * error and BPF programs will need to handle them.
2458 * 0 on success, or a negative error in case of failure.
2460 * int bpf_msg_pop_data(struct sk_msg_buff *msg, u32 start, u32 len, u64 flags)
2462 * Will remove *len* bytes from a *msg* starting at byte *start*.
2463 * This may result in **ENOMEM** errors under certain situations if
2464 * an allocation and copy are required due to a full ring buffer.
2465 * However, the helper will try to avoid doing the allocation
2466 * if possible. Other errors can occur if input parameters are
2467 * invalid either due to *start* byte not being valid part of *msg*
2468 * payload and/or *pop* value being to large.
2470 * 0 on success, or a negative error in case of failure.
2472 * int bpf_rc_pointer_rel(void *ctx, s32 rel_x, s32 rel_y)
2474 * This helper is used in programs implementing IR decoding, to
2475 * report a successfully decoded pointer movement.
2477 * The *ctx* should point to the lirc sample as passed into
2480 * This helper is only available is the kernel was compiled with
2481 * the **CONFIG_BPF_LIRC_MODE2** configuration option set to
2486 * int bpf_spin_lock(struct bpf_spin_lock *lock)
2488 * Acquire a spinlock represented by the pointer *lock*, which is
2489 * stored as part of a value of a map. Taking the lock allows to
2490 * safely update the rest of the fields in that value. The
2491 * spinlock can (and must) later be released with a call to
2492 * **bpf_spin_unlock**\ (\ *lock*\ ).
2494 * Spinlocks in BPF programs come with a number of restrictions
2497 * * **bpf_spin_lock** objects are only allowed inside maps of
2498 * types **BPF_MAP_TYPE_HASH** and **BPF_MAP_TYPE_ARRAY** (this
2499 * list could be extended in the future).
2500 * * BTF description of the map is mandatory.
2501 * * The BPF program can take ONE lock at a time, since taking two
2502 * or more could cause dead locks.
2503 * * Only one **struct bpf_spin_lock** is allowed per map element.
2504 * * When the lock is taken, calls (either BPF to BPF or helpers)
2506 * * The **BPF_LD_ABS** and **BPF_LD_IND** instructions are not
2507 * allowed inside a spinlock-ed region.
2508 * * The BPF program MUST call **bpf_spin_unlock**\ () to release
2509 * the lock, on all execution paths, before it returns.
2510 * * The BPF program can access **struct bpf_spin_lock** only via
2511 * the **bpf_spin_lock**\ () and **bpf_spin_unlock**\ ()
2512 * helpers. Loading or storing data into the **struct
2513 * bpf_spin_lock** *lock*\ **;** field of a map is not allowed.
2514 * * To use the **bpf_spin_lock**\ () helper, the BTF description
2515 * of the map value must be a struct and have **struct
2516 * bpf_spin_lock** *anyname*\ **;** field at the top level.
2517 * Nested lock inside another struct is not allowed.
2518 * * The **struct bpf_spin_lock** *lock* field in a map value must
2519 * be aligned on a multiple of 4 bytes in that value.
2520 * * Syscall with command **BPF_MAP_LOOKUP_ELEM** does not copy
2521 * the **bpf_spin_lock** field to user space.
2522 * * Syscall with command **BPF_MAP_UPDATE_ELEM**, or update from
2523 * a BPF program, do not update the **bpf_spin_lock** field.
2524 * * **bpf_spin_lock** cannot be on the stack or inside a
2525 * networking packet (it can only be inside of a map values).
2526 * * **bpf_spin_lock** is available to root only.
2527 * * Tracing programs and socket filter programs cannot use
2528 * **bpf_spin_lock**\ () due to insufficient preemption checks
2529 * (but this may change in the future).
2530 * * **bpf_spin_lock** is not allowed in inner maps of map-in-map.
2534 * int bpf_spin_unlock(struct bpf_spin_lock *lock)
2536 * Release the *lock* previously locked by a call to
2537 * **bpf_spin_lock**\ (\ *lock*\ ).
2541 * struct bpf_sock *bpf_sk_fullsock(struct bpf_sock *sk)
2543 * This helper gets a **struct bpf_sock** pointer such
2544 * that all the fields in this **bpf_sock** can be accessed.
2546 * A **struct bpf_sock** pointer on success, or **NULL** in
2549 * struct bpf_tcp_sock *bpf_tcp_sock(struct bpf_sock *sk)
2551 * This helper gets a **struct bpf_tcp_sock** pointer from a
2552 * **struct bpf_sock** pointer.
2554 * A **struct bpf_tcp_sock** pointer on success, or **NULL** in
2557 * int bpf_skb_ecn_set_ce(struct sk_buff *skb)
2559 * Set ECN (Explicit Congestion Notification) field of IP header
2560 * to **CE** (Congestion Encountered) if current value is **ECT**
2561 * (ECN Capable Transport). Otherwise, do nothing. Works with IPv6
2564 * 1 if the **CE** flag is set (either by the current helper call
2565 * or because it was already present), 0 if it is not set.
2567 * struct bpf_sock *bpf_get_listener_sock(struct bpf_sock *sk)
2569 * Return a **struct bpf_sock** pointer in **TCP_LISTEN** state.
2570 * **bpf_sk_release**\ () is unnecessary and not allowed.
2572 * A **struct bpf_sock** pointer on success, or **NULL** in
2575 * struct bpf_sock *bpf_skc_lookup_tcp(void *ctx, struct bpf_sock_tuple *tuple, u32 tuple_size, u64 netns, u64 flags)
2577 * Look for TCP socket matching *tuple*, optionally in a child
2578 * network namespace *netns*. The return value must be checked,
2579 * and if non-**NULL**, released via **bpf_sk_release**\ ().
2581 * This function is identical to **bpf_sk_lookup_tcp**\ (), except
2582 * that it also returns timewait or request sockets. Use
2583 * **bpf_sk_fullsock**\ () or **bpf_tcp_sock**\ () to access the
2586 * This helper is available only if the kernel was compiled with
2587 * **CONFIG_NET** configuration option.
2589 * Pointer to **struct bpf_sock**, or **NULL** in case of failure.
2590 * For sockets with reuseport option, the **struct bpf_sock**
2591 * result is from *reuse*\ **->socks**\ [] using the hash of the
2594 * int bpf_tcp_check_syncookie(struct bpf_sock *sk, void *iph, u32 iph_len, struct tcphdr *th, u32 th_len)
2596 * Check whether *iph* and *th* contain a valid SYN cookie ACK for
2597 * the listening socket in *sk*.
2599 * *iph* points to the start of the IPv4 or IPv6 header, while
2600 * *iph_len* contains **sizeof**\ (**struct iphdr**) or
2601 * **sizeof**\ (**struct ip6hdr**).
2603 * *th* points to the start of the TCP header, while *th_len*
2604 * contains **sizeof**\ (**struct tcphdr**).
2607 * 0 if *iph* and *th* are a valid SYN cookie ACK, or a negative
2610 * int bpf_sysctl_get_name(struct bpf_sysctl *ctx, char *buf, size_t buf_len, u64 flags)
2612 * Get name of sysctl in /proc/sys/ and copy it into provided by
2613 * program buffer *buf* of size *buf_len*.
2615 * The buffer is always NUL terminated, unless it's zero-sized.
2617 * If *flags* is zero, full name (e.g. "net/ipv4/tcp_mem") is
2618 * copied. Use **BPF_F_SYSCTL_BASE_NAME** flag to copy base name
2619 * only (e.g. "tcp_mem").
2621 * Number of character copied (not including the trailing NUL).
2623 * **-E2BIG** if the buffer wasn't big enough (*buf* will contain
2624 * truncated name in this case).
2626 * int bpf_sysctl_get_current_value(struct bpf_sysctl *ctx, char *buf, size_t buf_len)
2628 * Get current value of sysctl as it is presented in /proc/sys
2629 * (incl. newline, etc), and copy it as a string into provided
2630 * by program buffer *buf* of size *buf_len*.
2632 * The whole value is copied, no matter what file position user
2633 * space issued e.g. sys_read at.
2635 * The buffer is always NUL terminated, unless it's zero-sized.
2637 * Number of character copied (not including the trailing NUL).
2639 * **-E2BIG** if the buffer wasn't big enough (*buf* will contain
2640 * truncated name in this case).
2642 * **-EINVAL** if current value was unavailable, e.g. because
2643 * sysctl is uninitialized and read returns -EIO for it.
2645 * int bpf_sysctl_get_new_value(struct bpf_sysctl *ctx, char *buf, size_t buf_len)
2647 * Get new value being written by user space to sysctl (before
2648 * the actual write happens) and copy it as a string into
2649 * provided by program buffer *buf* of size *buf_len*.
2651 * User space may write new value at file position > 0.
2653 * The buffer is always NUL terminated, unless it's zero-sized.
2655 * Number of character copied (not including the trailing NUL).
2657 * **-E2BIG** if the buffer wasn't big enough (*buf* will contain
2658 * truncated name in this case).
2660 * **-EINVAL** if sysctl is being read.
2662 * int bpf_sysctl_set_new_value(struct bpf_sysctl *ctx, const char *buf, size_t buf_len)
2664 * Override new value being written by user space to sysctl with
2665 * value provided by program in buffer *buf* of size *buf_len*.
2667 * *buf* should contain a string in same form as provided by user
2668 * space on sysctl write.
2670 * User space may write new value at file position > 0. To override
2671 * the whole sysctl value file position should be set to zero.
2675 * **-E2BIG** if the *buf_len* is too big.
2677 * **-EINVAL** if sysctl is being read.
2679 * int bpf_strtol(const char *buf, size_t buf_len, u64 flags, long *res)
2681 * Convert the initial part of the string from buffer *buf* of
2682 * size *buf_len* to a long integer according to the given base
2683 * and save the result in *res*.
2685 * The string may begin with an arbitrary amount of white space
2686 * (as determined by **isspace**\ (3)) followed by a single
2687 * optional '**-**' sign.
2689 * Five least significant bits of *flags* encode base, other bits
2690 * are currently unused.
2692 * Base must be either 8, 10, 16 or 0 to detect it automatically
2693 * similar to user space **strtol**\ (3).
2695 * Number of characters consumed on success. Must be positive but
2696 * no more than *buf_len*.
2698 * **-EINVAL** if no valid digits were found or unsupported base
2701 * **-ERANGE** if resulting value was out of range.
2703 * int bpf_strtoul(const char *buf, size_t buf_len, u64 flags, unsigned long *res)
2705 * Convert the initial part of the string from buffer *buf* of
2706 * size *buf_len* to an unsigned long integer according to the
2707 * given base and save the result in *res*.
2709 * The string may begin with an arbitrary amount of white space
2710 * (as determined by **isspace**\ (3)).
2712 * Five least significant bits of *flags* encode base, other bits
2713 * are currently unused.
2715 * Base must be either 8, 10, 16 or 0 to detect it automatically
2716 * similar to user space **strtoul**\ (3).
2718 * Number of characters consumed on success. Must be positive but
2719 * no more than *buf_len*.
2721 * **-EINVAL** if no valid digits were found or unsupported base
2724 * **-ERANGE** if resulting value was out of range.
2726 * void *bpf_sk_storage_get(struct bpf_map *map, struct bpf_sock *sk, void *value, u64 flags)
2728 * Get a bpf-local-storage from a *sk*.
2730 * Logically, it could be thought of getting the value from
2731 * a *map* with *sk* as the **key**. From this
2732 * perspective, the usage is not much different from
2733 * **bpf_map_lookup_elem**\ (*map*, **&**\ *sk*) except this
2734 * helper enforces the key must be a full socket and the map must
2735 * be a **BPF_MAP_TYPE_SK_STORAGE** also.
2737 * Underneath, the value is stored locally at *sk* instead of
2738 * the *map*. The *map* is used as the bpf-local-storage
2739 * "type". The bpf-local-storage "type" (i.e. the *map*) is
2740 * searched against all bpf-local-storages residing at *sk*.
2742 * An optional *flags* (**BPF_SK_STORAGE_GET_F_CREATE**) can be
2743 * used such that a new bpf-local-storage will be
2744 * created if one does not exist. *value* can be used
2745 * together with **BPF_SK_STORAGE_GET_F_CREATE** to specify
2746 * the initial value of a bpf-local-storage. If *value* is
2747 * **NULL**, the new bpf-local-storage will be zero initialized.
2749 * A bpf-local-storage pointer is returned on success.
2751 * **NULL** if not found or there was an error in adding
2752 * a new bpf-local-storage.
2754 * int bpf_sk_storage_delete(struct bpf_map *map, struct bpf_sock *sk)
2756 * Delete a bpf-local-storage from a *sk*.
2760 * **-ENOENT** if the bpf-local-storage cannot be found.
2762 * int bpf_send_signal(u32 sig)
2764 * Send signal *sig* to the process of the current task.
2765 * The signal may be delivered to any of this process's threads.
2767 * 0 on success or successfully queued.
2769 * **-EBUSY** if work queue under nmi is full.
2771 * **-EINVAL** if *sig* is invalid.
2773 * **-EPERM** if no permission to send the *sig*.
2775 * **-EAGAIN** if bpf program can try again.
2777 * s64 bpf_tcp_gen_syncookie(struct bpf_sock *sk, void *iph, u32 iph_len, struct tcphdr *th, u32 th_len)
2779 * Try to issue a SYN cookie for the packet with corresponding
2780 * IP/TCP headers, *iph* and *th*, on the listening socket in *sk*.
2782 * *iph* points to the start of the IPv4 or IPv6 header, while
2783 * *iph_len* contains **sizeof**\ (**struct iphdr**) or
2784 * **sizeof**\ (**struct ip6hdr**).
2786 * *th* points to the start of the TCP header, while *th_len*
2787 * contains the length of the TCP header.
2790 * On success, lower 32 bits hold the generated SYN cookie in
2791 * followed by 16 bits which hold the MSS value for that cookie,
2792 * and the top 16 bits are unused.
2794 * On failure, the returned value is one of the following:
2796 * **-EINVAL** SYN cookie cannot be issued due to error
2798 * **-ENOENT** SYN cookie should not be issued (no SYN flood)
2800 * **-EOPNOTSUPP** kernel configuration does not enable SYN cookies
2802 * **-EPROTONOSUPPORT** IP packet version is not 4 or 6
2804 * int bpf_skb_output(void *ctx, struct bpf_map *map, u64 flags, void *data, u64 size)
2806 * Write raw *data* blob into a special BPF perf event held by
2807 * *map* of type **BPF_MAP_TYPE_PERF_EVENT_ARRAY**. This perf
2808 * event must have the following attributes: **PERF_SAMPLE_RAW**
2809 * as **sample_type**, **PERF_TYPE_SOFTWARE** as **type**, and
2810 * **PERF_COUNT_SW_BPF_OUTPUT** as **config**.
2812 * The *flags* are used to indicate the index in *map* for which
2813 * the value must be put, masked with **BPF_F_INDEX_MASK**.
2814 * Alternatively, *flags* can be set to **BPF_F_CURRENT_CPU**
2815 * to indicate that the index of the current CPU core should be
2818 * The value to write, of *size*, is passed through eBPF stack and
2819 * pointed by *data*.
2821 * *ctx* is a pointer to in-kernel struct sk_buff.
2823 * This helper is similar to **bpf_perf_event_output**\ () but
2824 * restricted to raw_tracepoint bpf programs.
2826 * 0 on success, or a negative error in case of failure.
2828 * int bpf_probe_read_user(void *dst, u32 size, const void *unsafe_ptr)
2830 * Safely attempt to read *size* bytes from user space address
2831 * *unsafe_ptr* and store the data in *dst*.
2833 * 0 on success, or a negative error in case of failure.
2835 * int bpf_probe_read_kernel(void *dst, u32 size, const void *unsafe_ptr)
2837 * Safely attempt to read *size* bytes from kernel space address
2838 * *unsafe_ptr* and store the data in *dst*.
2840 * 0 on success, or a negative error in case of failure.
2842 * int bpf_probe_read_user_str(void *dst, u32 size, const void *unsafe_ptr)
2844 * Copy a NUL terminated string from an unsafe user address
2845 * *unsafe_ptr* to *dst*. The *size* should include the
2846 * terminating NUL byte. In case the string length is smaller than
2847 * *size*, the target is not padded with further NUL bytes. If the
2848 * string length is larger than *size*, just *size*-1 bytes are
2849 * copied and the last byte is set to NUL.
2851 * On success, the length of the copied string is returned. This
2852 * makes this helper useful in tracing programs for reading
2853 * strings, and more importantly to get its length at runtime. See
2854 * the following snippet:
2858 * SEC("kprobe/sys_open")
2859 * void bpf_sys_open(struct pt_regs *ctx)
2861 * char buf[PATHLEN]; // PATHLEN is defined to 256
2862 * int res = bpf_probe_read_user_str(buf, sizeof(buf),
2865 * // Consume buf, for example push it to
2866 * // userspace via bpf_perf_event_output(); we
2867 * // can use res (the string length) as event
2868 * // size, after checking its boundaries.
2871 * In comparison, using **bpf_probe_read_user()** helper here
2872 * instead to read the string would require to estimate the length
2873 * at compile time, and would often result in copying more memory
2876 * Another useful use case is when parsing individual process
2877 * arguments or individual environment variables navigating
2878 * *current*\ **->mm->arg_start** and *current*\
2879 * **->mm->env_start**: using this helper and the return value,
2880 * one can quickly iterate at the right offset of the memory area.
2882 * On success, the strictly positive length of the string,
2883 * including the trailing NUL character. On error, a negative
2886 * int bpf_probe_read_kernel_str(void *dst, u32 size, const void *unsafe_ptr)
2888 * Copy a NUL terminated string from an unsafe kernel address *unsafe_ptr*
2889 * to *dst*. Same semantics as with bpf_probe_read_user_str() apply.
2891 * On success, the strictly positive length of the string, including
2892 * the trailing NUL character. On error, a negative value.
2894 * int bpf_tcp_send_ack(void *tp, u32 rcv_nxt)
2896 * Send out a tcp-ack. *tp* is the in-kernel struct tcp_sock.
2897 * *rcv_nxt* is the ack_seq to be sent out.
2899 * 0 on success, or a negative error in case of failure.
2901 * int bpf_send_signal_thread(u32 sig)
2903 * Send signal *sig* to the thread corresponding to the current task.
2905 * 0 on success or successfully queued.
2907 * **-EBUSY** if work queue under nmi is full.
2909 * **-EINVAL** if *sig* is invalid.
2911 * **-EPERM** if no permission to send the *sig*.
2913 * **-EAGAIN** if bpf program can try again.
2915 * u64 bpf_jiffies64(void)
2917 * Obtain the 64bit jiffies
2919 * The 64 bit jiffies
2921 * int bpf_read_branch_records(struct bpf_perf_event_data *ctx, void *buf, u32 size, u64 flags)
2923 * For an eBPF program attached to a perf event, retrieve the
2924 * branch records (struct perf_branch_entry) associated to *ctx*
2925 * and store it in the buffer pointed by *buf* up to size
2928 * On success, number of bytes written to *buf*. On error, a
2931 * The *flags* can be set to **BPF_F_GET_BRANCH_RECORDS_SIZE** to
2932 * instead return the number of bytes required to store all the
2933 * branch entries. If this flag is set, *buf* may be NULL.
2935 * **-EINVAL** if arguments invalid or **size** not a multiple
2936 * of sizeof(struct perf_branch_entry).
2938 * **-ENOENT** if architecture does not support branch records.
2940 * int bpf_get_ns_current_pid_tgid(u64 dev, u64 ino, struct bpf_pidns_info *nsdata, u32 size)
2942 * Returns 0 on success, values for *pid* and *tgid* as seen from the current
2943 * *namespace* will be returned in *nsdata*.
2945 * On failure, the returned value is one of the following:
2947 * **-EINVAL** if dev and inum supplied don't match dev_t and inode number
2948 * with nsfs of current task, or if dev conversion to dev_t lost high bits.
2950 * **-ENOENT** if pidns does not exists for the current task.
2952 * int bpf_xdp_output(void *ctx, struct bpf_map *map, u64 flags, void *data, u64 size)
2954 * Write raw *data* blob into a special BPF perf event held by
2955 * *map* of type **BPF_MAP_TYPE_PERF_EVENT_ARRAY**. This perf
2956 * event must have the following attributes: **PERF_SAMPLE_RAW**
2957 * as **sample_type**, **PERF_TYPE_SOFTWARE** as **type**, and
2958 * **PERF_COUNT_SW_BPF_OUTPUT** as **config**.
2960 * The *flags* are used to indicate the index in *map* for which
2961 * the value must be put, masked with **BPF_F_INDEX_MASK**.
2962 * Alternatively, *flags* can be set to **BPF_F_CURRENT_CPU**
2963 * to indicate that the index of the current CPU core should be
2966 * The value to write, of *size*, is passed through eBPF stack and
2967 * pointed by *data*.
2969 * *ctx* is a pointer to in-kernel struct xdp_buff.
2971 * This helper is similar to **bpf_perf_eventoutput**\ () but
2972 * restricted to raw_tracepoint bpf programs.
2974 * 0 on success, or a negative error in case of failure.
2976 * u64 bpf_get_netns_cookie(void *ctx)
2978 * Retrieve the cookie (generated by the kernel) of the network
2979 * namespace the input *ctx* is associated with. The network
2980 * namespace cookie remains stable for its lifetime and provides
2981 * a global identifier that can be assumed unique. If *ctx* is
2982 * NULL, then the helper returns the cookie for the initial
2983 * network namespace. The cookie itself is very similar to that
2984 * of bpf_get_socket_cookie() helper, but for network namespaces
2985 * instead of sockets.
2987 * A 8-byte long opaque number.
2989 * u64 bpf_get_current_ancestor_cgroup_id(int ancestor_level)
2991 * Return id of cgroup v2 that is ancestor of the cgroup associated
2992 * with the current task at the *ancestor_level*. The root cgroup
2993 * is at *ancestor_level* zero and each step down the hierarchy
2994 * increments the level. If *ancestor_level* == level of cgroup
2995 * associated with the current task, then return value will be the
2996 * same as that of **bpf_get_current_cgroup_id**\ ().
2998 * The helper is useful to implement policies based on cgroups
2999 * that are upper in hierarchy than immediate cgroup associated
3000 * with the current task.
3002 * The format of returned id and helper limitations are same as in
3003 * **bpf_get_current_cgroup_id**\ ().
3005 * The id is returned or 0 in case the id could not be retrieved.
3007 * int bpf_sk_assign(struct sk_buff *skb, struct bpf_sock *sk, u64 flags)
3009 * Assign the *sk* to the *skb*. When combined with appropriate
3010 * routing configuration to receive the packet towards the socket,
3011 * will cause *skb* to be delivered to the specified socket.
3012 * Subsequent redirection of *skb* via **bpf_redirect**\ (),
3013 * **bpf_clone_redirect**\ () or other methods outside of BPF may
3014 * interfere with successful delivery to the socket.
3016 * This operation is only valid from TC ingress path.
3018 * The *flags* argument must be zero.
3020 * 0 on success, or a negative errno in case of failure.
3022 * * **-EINVAL** Unsupported flags specified.
3023 * * **-ENOENT** Socket is unavailable for assignment.
3024 * * **-ENETUNREACH** Socket is unreachable (wrong netns).
3025 * * **-EOPNOTSUPP** Unsupported operation, for example a
3026 * call from outside of TC ingress.
3027 * * **-ESOCKTNOSUPPORT** Socket type not supported (reuseport).
3029 #define __BPF_FUNC_MAPPER(FN) \
3031 FN(map_lookup_elem), \
3032 FN(map_update_elem), \
3033 FN(map_delete_elem), \
3037 FN(get_prandom_u32), \
3038 FN(get_smp_processor_id), \
3039 FN(skb_store_bytes), \
3040 FN(l3_csum_replace), \
3041 FN(l4_csum_replace), \
3043 FN(clone_redirect), \
3044 FN(get_current_pid_tgid), \
3045 FN(get_current_uid_gid), \
3046 FN(get_current_comm), \
3047 FN(get_cgroup_classid), \
3048 FN(skb_vlan_push), \
3050 FN(skb_get_tunnel_key), \
3051 FN(skb_set_tunnel_key), \
3052 FN(perf_event_read), \
3054 FN(get_route_realm), \
3055 FN(perf_event_output), \
3056 FN(skb_load_bytes), \
3059 FN(skb_get_tunnel_opt), \
3060 FN(skb_set_tunnel_opt), \
3061 FN(skb_change_proto), \
3062 FN(skb_change_type), \
3063 FN(skb_under_cgroup), \
3064 FN(get_hash_recalc), \
3065 FN(get_current_task), \
3066 FN(probe_write_user), \
3067 FN(current_task_under_cgroup), \
3068 FN(skb_change_tail), \
3069 FN(skb_pull_data), \
3071 FN(set_hash_invalid), \
3072 FN(get_numa_node_id), \
3073 FN(skb_change_head), \
3074 FN(xdp_adjust_head), \
3075 FN(probe_read_str), \
3076 FN(get_socket_cookie), \
3077 FN(get_socket_uid), \
3080 FN(skb_adjust_room), \
3082 FN(sk_redirect_map), \
3083 FN(sock_map_update), \
3084 FN(xdp_adjust_meta), \
3085 FN(perf_event_read_value), \
3086 FN(perf_prog_read_value), \
3088 FN(override_return), \
3089 FN(sock_ops_cb_flags_set), \
3090 FN(msg_redirect_map), \
3091 FN(msg_apply_bytes), \
3092 FN(msg_cork_bytes), \
3093 FN(msg_pull_data), \
3095 FN(xdp_adjust_tail), \
3096 FN(skb_get_xfrm_state), \
3098 FN(skb_load_bytes_relative), \
3100 FN(sock_hash_update), \
3101 FN(msg_redirect_hash), \
3102 FN(sk_redirect_hash), \
3103 FN(lwt_push_encap), \
3104 FN(lwt_seg6_store_bytes), \
3105 FN(lwt_seg6_adjust_srh), \
3106 FN(lwt_seg6_action), \
3109 FN(skb_cgroup_id), \
3110 FN(get_current_cgroup_id), \
3111 FN(get_local_storage), \
3112 FN(sk_select_reuseport), \
3113 FN(skb_ancestor_cgroup_id), \
3114 FN(sk_lookup_tcp), \
3115 FN(sk_lookup_udp), \
3117 FN(map_push_elem), \
3119 FN(map_peek_elem), \
3120 FN(msg_push_data), \
3122 FN(rc_pointer_rel), \
3127 FN(skb_ecn_set_ce), \
3128 FN(get_listener_sock), \
3129 FN(skc_lookup_tcp), \
3130 FN(tcp_check_syncookie), \
3131 FN(sysctl_get_name), \
3132 FN(sysctl_get_current_value), \
3133 FN(sysctl_get_new_value), \
3134 FN(sysctl_set_new_value), \
3137 FN(sk_storage_get), \
3138 FN(sk_storage_delete), \
3140 FN(tcp_gen_syncookie), \
3142 FN(probe_read_user), \
3143 FN(probe_read_kernel), \
3144 FN(probe_read_user_str), \
3145 FN(probe_read_kernel_str), \
3147 FN(send_signal_thread), \
3149 FN(read_branch_records), \
3150 FN(get_ns_current_pid_tgid), \
3152 FN(get_netns_cookie), \
3153 FN(get_current_ancestor_cgroup_id), \
3156 /* integer value in 'imm' field of BPF_CALL instruction selects which helper
3157 * function eBPF program intends to call
3159 #define __BPF_ENUM_FN(x) BPF_FUNC_ ## x
3161 __BPF_FUNC_MAPPER(__BPF_ENUM_FN)
3164 #undef __BPF_ENUM_FN
3166 /* All flags used by eBPF helper functions, placed here. */
3168 /* BPF_FUNC_skb_store_bytes flags. */
3170 BPF_F_RECOMPUTE_CSUM = (1ULL << 0),
3171 BPF_F_INVALIDATE_HASH = (1ULL << 1),
3174 /* BPF_FUNC_l3_csum_replace and BPF_FUNC_l4_csum_replace flags.
3175 * First 4 bits are for passing the header field size.
3178 BPF_F_HDR_FIELD_MASK = 0xfULL,
3181 /* BPF_FUNC_l4_csum_replace flags. */
3183 BPF_F_PSEUDO_HDR = (1ULL << 4),
3184 BPF_F_MARK_MANGLED_0 = (1ULL << 5),
3185 BPF_F_MARK_ENFORCE = (1ULL << 6),
3188 /* BPF_FUNC_clone_redirect and BPF_FUNC_redirect flags. */
3190 BPF_F_INGRESS = (1ULL << 0),
3193 /* BPF_FUNC_skb_set_tunnel_key and BPF_FUNC_skb_get_tunnel_key flags. */
3195 BPF_F_TUNINFO_IPV6 = (1ULL << 0),
3198 /* flags for both BPF_FUNC_get_stackid and BPF_FUNC_get_stack. */
3200 BPF_F_SKIP_FIELD_MASK = 0xffULL,
3201 BPF_F_USER_STACK = (1ULL << 8),
3202 /* flags used by BPF_FUNC_get_stackid only. */
3203 BPF_F_FAST_STACK_CMP = (1ULL << 9),
3204 BPF_F_REUSE_STACKID = (1ULL << 10),
3205 /* flags used by BPF_FUNC_get_stack only. */
3206 BPF_F_USER_BUILD_ID = (1ULL << 11),
3209 /* BPF_FUNC_skb_set_tunnel_key flags. */
3211 BPF_F_ZERO_CSUM_TX = (1ULL << 1),
3212 BPF_F_DONT_FRAGMENT = (1ULL << 2),
3213 BPF_F_SEQ_NUMBER = (1ULL << 3),
3216 /* BPF_FUNC_perf_event_output, BPF_FUNC_perf_event_read and
3217 * BPF_FUNC_perf_event_read_value flags.
3220 BPF_F_INDEX_MASK = 0xffffffffULL,
3221 BPF_F_CURRENT_CPU = BPF_F_INDEX_MASK,
3222 /* BPF_FUNC_perf_event_output for sk_buff input context. */
3223 BPF_F_CTXLEN_MASK = (0xfffffULL << 32),
3226 /* Current network namespace */
3228 BPF_F_CURRENT_NETNS = (-1L),
3231 /* BPF_FUNC_skb_adjust_room flags. */
3233 BPF_F_ADJ_ROOM_FIXED_GSO = (1ULL << 0),
3234 BPF_F_ADJ_ROOM_ENCAP_L3_IPV4 = (1ULL << 1),
3235 BPF_F_ADJ_ROOM_ENCAP_L3_IPV6 = (1ULL << 2),
3236 BPF_F_ADJ_ROOM_ENCAP_L4_GRE = (1ULL << 3),
3237 BPF_F_ADJ_ROOM_ENCAP_L4_UDP = (1ULL << 4),
3241 BPF_ADJ_ROOM_ENCAP_L2_MASK = 0xff,
3242 BPF_ADJ_ROOM_ENCAP_L2_SHIFT = 56,
3245 #define BPF_F_ADJ_ROOM_ENCAP_L2(len) (((__u64)len & \
3246 BPF_ADJ_ROOM_ENCAP_L2_MASK) \
3247 << BPF_ADJ_ROOM_ENCAP_L2_SHIFT)
3249 /* BPF_FUNC_sysctl_get_name flags. */
3251 BPF_F_SYSCTL_BASE_NAME = (1ULL << 0),
3254 /* BPF_FUNC_sk_storage_get flags */
3256 BPF_SK_STORAGE_GET_F_CREATE = (1ULL << 0),
3259 /* BPF_FUNC_read_branch_records flags. */
3261 BPF_F_GET_BRANCH_RECORDS_SIZE = (1ULL << 0),
3264 /* Mode for BPF_FUNC_skb_adjust_room helper. */
3265 enum bpf_adj_room_mode {
3270 /* Mode for BPF_FUNC_skb_load_bytes_relative helper. */
3271 enum bpf_hdr_start_off {
3276 /* Encapsulation type for BPF_FUNC_lwt_push_encap helper. */
3277 enum bpf_lwt_encap_mode {
3279 BPF_LWT_ENCAP_SEG6_INLINE,
3283 #define __bpf_md_ptr(type, name) \
3287 } __attribute__((aligned(8)))
3289 /* user accessible mirror of in-kernel sk_buff.
3290 * new fields can only be added to the end of this structure
3296 __u32 queue_mapping;
3302 __u32 ingress_ifindex;
3312 /* Accessed by BPF_PROG_TYPE_sk_skb types from here to ... */
3314 __u32 remote_ip4; /* Stored in network byte order */
3315 __u32 local_ip4; /* Stored in network byte order */
3316 __u32 remote_ip6[4]; /* Stored in network byte order */
3317 __u32 local_ip6[4]; /* Stored in network byte order */
3318 __u32 remote_port; /* Stored in network byte order */
3319 __u32 local_port; /* stored in host byte order */
3323 __bpf_md_ptr(struct bpf_flow_keys *, flow_keys);
3327 __bpf_md_ptr(struct bpf_sock *, sk);
3331 struct bpf_tunnel_key {
3335 __u32 remote_ipv6[4];
3339 __u16 tunnel_ext; /* Padding, future use. */
3343 /* user accessible mirror of in-kernel xfrm_state.
3344 * new fields can only be added to the end of this structure
3346 struct bpf_xfrm_state {
3348 __u32 spi; /* Stored in network byte order */
3350 __u16 ext; /* Padding, future use. */
3352 __u32 remote_ipv4; /* Stored in network byte order */
3353 __u32 remote_ipv6[4]; /* Stored in network byte order */
3357 /* Generic BPF return codes which all BPF program types may support.
3358 * The values are binary compatible with their TC_ACT_* counter-part to
3359 * provide backwards compatibility with existing SCHED_CLS and SCHED_ACT
3362 * XDP is handled seprately, see XDP_*.
3370 /* >127 are reserved for prog type specific return codes.
3372 * BPF_LWT_REROUTE: used by BPF_PROG_TYPE_LWT_IN and
3373 * BPF_PROG_TYPE_LWT_XMIT to indicate that skb had been
3374 * changed and should be routed based on its new L3 header.
3375 * (This is an L3 redirect, as opposed to L2 redirect
3376 * represented by BPF_REDIRECT above).
3378 BPF_LWT_REROUTE = 128,
3388 /* IP address also allows 1 and 2 bytes access */
3391 __u32 src_port; /* host byte order */
3392 __u32 dst_port; /* network byte order */
3398 struct bpf_tcp_sock {
3399 __u32 snd_cwnd; /* Sending congestion window */
3400 __u32 srtt_us; /* smoothed round trip time << 3 in usecs */
3402 __u32 snd_ssthresh; /* Slow start size threshold */
3403 __u32 rcv_nxt; /* What we want to receive next */
3404 __u32 snd_nxt; /* Next sequence we send */
3405 __u32 snd_una; /* First byte we want an ack for */
3406 __u32 mss_cache; /* Cached effective mss, not including SACKS */
3407 __u32 ecn_flags; /* ECN status bits. */
3408 __u32 rate_delivered; /* saved rate sample: packets delivered */
3409 __u32 rate_interval_us; /* saved rate sample: time elapsed */
3410 __u32 packets_out; /* Packets which are "in flight" */
3411 __u32 retrans_out; /* Retransmitted packets out */
3412 __u32 total_retrans; /* Total retransmits for entire connection */
3413 __u32 segs_in; /* RFC4898 tcpEStatsPerfSegsIn
3414 * total number of segments in.
3416 __u32 data_segs_in; /* RFC4898 tcpEStatsPerfDataSegsIn
3417 * total number of data segments in.
3419 __u32 segs_out; /* RFC4898 tcpEStatsPerfSegsOut
3420 * The total number of segments sent.
3422 __u32 data_segs_out; /* RFC4898 tcpEStatsPerfDataSegsOut
3423 * total number of data segments sent.
3425 __u32 lost_out; /* Lost packets */
3426 __u32 sacked_out; /* SACK'd packets */
3427 __u64 bytes_received; /* RFC4898 tcpEStatsAppHCThruOctetsReceived
3428 * sum(delta(rcv_nxt)), or how many bytes
3431 __u64 bytes_acked; /* RFC4898 tcpEStatsAppHCThruOctetsAcked
3432 * sum(delta(snd_una)), or how many bytes
3435 __u32 dsack_dups; /* RFC4898 tcpEStatsStackDSACKDups
3436 * total number of DSACK blocks received
3438 __u32 delivered; /* Total data packets delivered incl. rexmits */
3439 __u32 delivered_ce; /* Like the above but only ECE marked packets */
3440 __u32 icsk_retransmits; /* Number of unrecovered [RTO] timeouts */
3443 struct bpf_sock_tuple {
3460 struct bpf_xdp_sock {
3464 #define XDP_PACKET_HEADROOM 256
3466 /* User return codes for XDP prog type.
3467 * A valid XDP program must return one of these defined values. All other
3468 * return codes are reserved for future use. Unknown return codes will
3469 * result in packet drops and a warning via bpf_warn_invalid_xdp_action().
3479 /* user accessible metadata for XDP packet hook
3480 * new fields must be added to the end of this structure
3486 /* Below access go through struct xdp_rxq_info */
3487 __u32 ingress_ifindex; /* rxq->dev->ifindex */
3488 __u32 rx_queue_index; /* rxq->queue_index */
3496 /* user accessible metadata for SK_MSG packet hook, new fields must
3497 * be added to the end of this structure
3500 __bpf_md_ptr(void *, data);
3501 __bpf_md_ptr(void *, data_end);
3504 __u32 remote_ip4; /* Stored in network byte order */
3505 __u32 local_ip4; /* Stored in network byte order */
3506 __u32 remote_ip6[4]; /* Stored in network byte order */
3507 __u32 local_ip6[4]; /* Stored in network byte order */
3508 __u32 remote_port; /* Stored in network byte order */
3509 __u32 local_port; /* stored in host byte order */
3510 __u32 size; /* Total size of sk_msg */
3513 struct sk_reuseport_md {
3515 * Start of directly accessible data. It begins from
3516 * the tcp/udp header.
3518 __bpf_md_ptr(void *, data);
3519 /* End of directly accessible data */
3520 __bpf_md_ptr(void *, data_end);
3522 * Total length of packet (starting from the tcp/udp header).
3523 * Note that the directly accessible bytes (data_end - data)
3524 * could be less than this "len". Those bytes could be
3525 * indirectly read by a helper "bpf_skb_load_bytes()".
3529 * Eth protocol in the mac header (network byte order). e.g.
3530 * ETH_P_IP(0x0800) and ETH_P_IPV6(0x86DD)
3533 __u32 ip_protocol; /* IP protocol. e.g. IPPROTO_TCP, IPPROTO_UDP */
3534 __u32 bind_inany; /* Is sock bound to an INANY address? */
3535 __u32 hash; /* A hash of the packet 4 tuples */
3538 #define BPF_TAG_SIZE 8
3540 struct bpf_prog_info {
3543 __u8 tag[BPF_TAG_SIZE];
3544 __u32 jited_prog_len;
3545 __u32 xlated_prog_len;
3546 __aligned_u64 jited_prog_insns;
3547 __aligned_u64 xlated_prog_insns;
3548 __u64 load_time; /* ns since boottime */
3549 __u32 created_by_uid;
3551 __aligned_u64 map_ids;
3552 char name[BPF_OBJ_NAME_LEN];
3554 __u32 gpl_compatible:1;
3555 __u32 :31; /* alignment pad */
3558 __u32 nr_jited_ksyms;
3559 __u32 nr_jited_func_lens;
3560 __aligned_u64 jited_ksyms;
3561 __aligned_u64 jited_func_lens;
3563 __u32 func_info_rec_size;
3564 __aligned_u64 func_info;
3567 __aligned_u64 line_info;
3568 __aligned_u64 jited_line_info;
3569 __u32 nr_jited_line_info;
3570 __u32 line_info_rec_size;
3571 __u32 jited_line_info_rec_size;
3573 __aligned_u64 prog_tags;
3576 } __attribute__((aligned(8)));
3578 struct bpf_map_info {
3585 char name[BPF_OBJ_NAME_LEN];
3587 __u32 btf_vmlinux_value_type_id;
3591 __u32 btf_key_type_id;
3592 __u32 btf_value_type_id;
3593 } __attribute__((aligned(8)));
3595 struct bpf_btf_info {
3599 } __attribute__((aligned(8)));
3601 /* User bpf_sock_addr struct to access socket fields and sockaddr struct passed
3602 * by user and intended to be used by socket (e.g. to bind to, depends on
3603 * attach attach type).
3605 struct bpf_sock_addr {
3606 __u32 user_family; /* Allows 4-byte read, but no write. */
3607 __u32 user_ip4; /* Allows 1,2,4-byte read and 4-byte write.
3608 * Stored in network byte order.
3610 __u32 user_ip6[4]; /* Allows 1,2,4,8-byte read and 4,8-byte write.
3611 * Stored in network byte order.
3613 __u32 user_port; /* Allows 4-byte read and write.
3614 * Stored in network byte order
3616 __u32 family; /* Allows 4-byte read, but no write */
3617 __u32 type; /* Allows 4-byte read, but no write */
3618 __u32 protocol; /* Allows 4-byte read, but no write */
3619 __u32 msg_src_ip4; /* Allows 1,2,4-byte read and 4-byte write.
3620 * Stored in network byte order.
3622 __u32 msg_src_ip6[4]; /* Allows 1,2,4,8-byte read and 4,8-byte write.
3623 * Stored in network byte order.
3625 __bpf_md_ptr(struct bpf_sock *, sk);
3628 /* User bpf_sock_ops struct to access socket values and specify request ops
3629 * and their replies.
3630 * Some of this fields are in network (bigendian) byte order and may need
3631 * to be converted before use (bpf_ntohl() defined in samples/bpf/bpf_endian.h).
3632 * New fields can only be added at the end of this structure
3634 struct bpf_sock_ops {
3637 __u32 args[4]; /* Optionally passed to bpf program */
3638 __u32 reply; /* Returned by bpf program */
3639 __u32 replylong[4]; /* Optionally returned by bpf prog */
3642 __u32 remote_ip4; /* Stored in network byte order */
3643 __u32 local_ip4; /* Stored in network byte order */
3644 __u32 remote_ip6[4]; /* Stored in network byte order */
3645 __u32 local_ip6[4]; /* Stored in network byte order */
3646 __u32 remote_port; /* Stored in network byte order */
3647 __u32 local_port; /* stored in host byte order */
3648 __u32 is_fullsock; /* Some TCP fields are only valid if
3649 * there is a full socket. If not, the
3650 * fields read as zero.
3653 __u32 srtt_us; /* Averaged RTT << 3 in usecs */
3654 __u32 bpf_sock_ops_cb_flags; /* flags defined in uapi/linux/tcp.h */
3663 __u32 rate_delivered;
3664 __u32 rate_interval_us;
3667 __u32 total_retrans;
3671 __u32 data_segs_out;
3675 __u64 bytes_received;
3677 __bpf_md_ptr(struct bpf_sock *, sk);
3680 /* Definitions for bpf_sock_ops_cb_flags */
3682 BPF_SOCK_OPS_RTO_CB_FLAG = (1<<0),
3683 BPF_SOCK_OPS_RETRANS_CB_FLAG = (1<<1),
3684 BPF_SOCK_OPS_STATE_CB_FLAG = (1<<2),
3685 BPF_SOCK_OPS_RTT_CB_FLAG = (1<<3),
3686 /* Mask of all currently supported cb flags */
3687 BPF_SOCK_OPS_ALL_CB_FLAGS = 0xF,
3690 /* List of known BPF sock_ops operators.
3691 * New entries can only be added at the end
3695 BPF_SOCK_OPS_TIMEOUT_INIT, /* Should return SYN-RTO value to use or
3696 * -1 if default value should be used
3698 BPF_SOCK_OPS_RWND_INIT, /* Should return initial advertized
3699 * window (in packets) or -1 if default
3700 * value should be used
3702 BPF_SOCK_OPS_TCP_CONNECT_CB, /* Calls BPF program right before an
3703 * active connection is initialized
3705 BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB, /* Calls BPF program when an
3706 * active connection is
3709 BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB, /* Calls BPF program when a
3710 * passive connection is
3713 BPF_SOCK_OPS_NEEDS_ECN, /* If connection's congestion control
3716 BPF_SOCK_OPS_BASE_RTT, /* Get base RTT. The correct value is
3717 * based on the path and may be
3718 * dependent on the congestion control
3719 * algorithm. In general it indicates
3720 * a congestion threshold. RTTs above
3721 * this indicate congestion
3723 BPF_SOCK_OPS_RTO_CB, /* Called when an RTO has triggered.
3724 * Arg1: value of icsk_retransmits
3725 * Arg2: value of icsk_rto
3726 * Arg3: whether RTO has expired
3728 BPF_SOCK_OPS_RETRANS_CB, /* Called when skb is retransmitted.
3729 * Arg1: sequence number of 1st byte
3731 * Arg3: return value of
3732 * tcp_transmit_skb (0 => success)
3734 BPF_SOCK_OPS_STATE_CB, /* Called when TCP changes state.
3738 BPF_SOCK_OPS_TCP_LISTEN_CB, /* Called on listen(2), right after
3739 * socket transition to LISTEN state.
3741 BPF_SOCK_OPS_RTT_CB, /* Called on every RTT.
3745 /* List of TCP states. There is a build check in net/ipv4/tcp.c to detect
3746 * changes between the TCP and BPF versions. Ideally this should never happen.
3747 * If it does, we need to add code to convert them before calling
3748 * the BPF sock_ops function.
3751 BPF_TCP_ESTABLISHED = 1,
3761 BPF_TCP_CLOSING, /* Now a valid state */
3762 BPF_TCP_NEW_SYN_RECV,
3764 BPF_TCP_MAX_STATES /* Leave at the end! */
3768 TCP_BPF_IW = 1001, /* Set TCP initial congestion window */
3769 TCP_BPF_SNDCWND_CLAMP = 1002, /* Set sndcwnd_clamp */
3772 struct bpf_perf_event_value {
3779 BPF_DEVCG_ACC_MKNOD = (1ULL << 0),
3780 BPF_DEVCG_ACC_READ = (1ULL << 1),
3781 BPF_DEVCG_ACC_WRITE = (1ULL << 2),
3785 BPF_DEVCG_DEV_BLOCK = (1ULL << 0),
3786 BPF_DEVCG_DEV_CHAR = (1ULL << 1),
3789 struct bpf_cgroup_dev_ctx {
3790 /* access_type encoded as (BPF_DEVCG_ACC_* << 16) | BPF_DEVCG_DEV_* */
3796 struct bpf_raw_tracepoint_args {
3800 /* DIRECT: Skip the FIB rules and go to FIB table associated with device
3801 * OUTPUT: Do lookup from egress perspective; default is ingress
3804 BPF_FIB_LOOKUP_DIRECT = (1U << 0),
3805 BPF_FIB_LOOKUP_OUTPUT = (1U << 1),
3809 BPF_FIB_LKUP_RET_SUCCESS, /* lookup successful */
3810 BPF_FIB_LKUP_RET_BLACKHOLE, /* dest is blackholed; can be dropped */
3811 BPF_FIB_LKUP_RET_UNREACHABLE, /* dest is unreachable; can be dropped */
3812 BPF_FIB_LKUP_RET_PROHIBIT, /* dest not allowed; can be dropped */
3813 BPF_FIB_LKUP_RET_NOT_FWDED, /* packet is not forwarded */
3814 BPF_FIB_LKUP_RET_FWD_DISABLED, /* fwding is not enabled on ingress */
3815 BPF_FIB_LKUP_RET_UNSUPP_LWT, /* fwd requires encapsulation */
3816 BPF_FIB_LKUP_RET_NO_NEIGH, /* no neighbor entry for nh */
3817 BPF_FIB_LKUP_RET_FRAG_NEEDED, /* fragmentation required to fwd */
3820 struct bpf_fib_lookup {
3821 /* input: network family for lookup (AF_INET, AF_INET6)
3822 * output: network family of egress nexthop
3826 /* set if lookup is to consider L4 data - e.g., FIB rules */
3831 /* total length of packet from network header - used for MTU check */
3834 /* input: L3 device index for lookup
3835 * output: device index from FIB lookup
3840 /* inputs to lookup */
3841 __u8 tos; /* AF_INET */
3842 __be32 flowinfo; /* AF_INET6, flow_label + priority */
3844 /* output: metric of fib result (IPv4/IPv6 only) */
3850 __u32 ipv6_src[4]; /* in6_addr; network order */
3853 /* input to bpf_fib_lookup, ipv{4,6}_dst is destination address in
3854 * network header. output: bpf_fib_lookup sets to gateway address
3855 * if FIB lookup returns gateway route
3859 __u32 ipv6_dst[4]; /* in6_addr; network order */
3863 __be16 h_vlan_proto;
3865 __u8 smac[6]; /* ETH_ALEN */
3866 __u8 dmac[6]; /* ETH_ALEN */
3869 enum bpf_task_fd_type {
3870 BPF_FD_TYPE_RAW_TRACEPOINT, /* tp name */
3871 BPF_FD_TYPE_TRACEPOINT, /* tp name */
3872 BPF_FD_TYPE_KPROBE, /* (symbol + offset) or addr */
3873 BPF_FD_TYPE_KRETPROBE, /* (symbol + offset) or addr */
3874 BPF_FD_TYPE_UPROBE, /* filename + offset */
3875 BPF_FD_TYPE_URETPROBE, /* filename + offset */
3879 BPF_FLOW_DISSECTOR_F_PARSE_1ST_FRAG = (1U << 0),
3880 BPF_FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL = (1U << 1),
3881 BPF_FLOW_DISSECTOR_F_STOP_AT_ENCAP = (1U << 2),
3884 struct bpf_flow_keys {
3887 __u16 addr_proto; /* ETH_P_* of valid addrs */
3901 __u32 ipv6_src[4]; /* in6_addr; network order */
3902 __u32 ipv6_dst[4]; /* in6_addr; network order */
3909 struct bpf_func_info {
3914 #define BPF_LINE_INFO_LINE_NUM(line_col) ((line_col) >> 10)
3915 #define BPF_LINE_INFO_LINE_COL(line_col) ((line_col) & 0x3ff)
3917 struct bpf_line_info {
3919 __u32 file_name_off;
3924 struct bpf_spin_lock {
3929 __u32 write; /* Sysctl is being read (= 0) or written (= 1).
3930 * Allows 1,2,4-byte read, but no write.
3932 __u32 file_pos; /* Sysctl file position to read from, write to.
3933 * Allows 1,2,4-byte read an 4-byte write.
3937 struct bpf_sockopt {
3938 __bpf_md_ptr(struct bpf_sock *, sk);
3939 __bpf_md_ptr(void *, optval);
3940 __bpf_md_ptr(void *, optval_end);
3948 struct bpf_pidns_info {
3952 #endif /* _UAPI__LINUX_BPF_H__ */
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