selftests/bpf: Rewrite test_sock_addr bind bpf into C

I'm planning to extend it in the next patches. It's much easier to
work with C than BPF assembly.

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20201202172516.3483656-2-sdf@google.com

diff --git a/tools/testing/selftests/bpf/progs/bind4_prog.c b/tools/testing/selftests/bpf/progs/bind4_prog.c
new file mode 100644 (file)
index 0000000..0951302
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/bind4_prog.c
@@ -0,0 +1,71 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <string.h>
+
+#include <linux/stddef.h>
+#include <linux/bpf.h>
+#include <linux/in.h>
+#include <linux/in6.h>
+#include <sys/socket.h>
+#include <netinet/tcp.h>
+#include <linux/if.h>
+#include <errno.h>
+
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_endian.h>
+
+#define SERV4_IP               0xc0a801feU /* 192.168.1.254 */
+#define SERV4_PORT             4040
+#define SERV4_REWRITE_IP       0x7f000001U /* 127.0.0.1 */
+#define SERV4_REWRITE_PORT     4444
+
+SEC("cgroup/bind4")
+int bind_v4_prog(struct bpf_sock_addr *ctx)
+{
+       struct bpf_sock *sk;
+       __u32 user_ip4;
+       __u16 user_port;
+
+       sk = ctx->sk;
+       if (!sk)
+               return 0;
+
+       if (sk->family != AF_INET)
+               return 0;
+
+       if (ctx->type != SOCK_STREAM && ctx->type != SOCK_DGRAM)
+               return 0;
+
+       if (ctx->user_ip4 != bpf_htonl(SERV4_IP) ||
+           ctx->user_port != bpf_htons(SERV4_PORT))
+               return 0;
+
+       // u8 narrow loads:
+       user_ip4 = 0;
+       user_ip4 |= ((volatile __u8 *)&ctx->user_ip4)[0] << 0;
+       user_ip4 |= ((volatile __u8 *)&ctx->user_ip4)[1] << 8;
+       user_ip4 |= ((volatile __u8 *)&ctx->user_ip4)[2] << 16;
+       user_ip4 |= ((volatile __u8 *)&ctx->user_ip4)[3] << 24;
+       if (ctx->user_ip4 != user_ip4)
+               return 0;
+
+       user_port = 0;
+       user_port |= ((volatile __u8 *)&ctx->user_port)[0] << 0;
+       user_port |= ((volatile __u8 *)&ctx->user_port)[1] << 8;
+       if (ctx->user_port != user_port)
+               return 0;
+
+       // u16 narrow loads:
+       user_ip4 = 0;
+       user_ip4 |= ((volatile __u16 *)&ctx->user_ip4)[0] << 0;
+       user_ip4 |= ((volatile __u16 *)&ctx->user_ip4)[1] << 16;
+       if (ctx->user_ip4 != user_ip4)
+               return 0;
+
+       ctx->user_ip4 = bpf_htonl(SERV4_REWRITE_IP);
+       ctx->user_port = bpf_htons(SERV4_REWRITE_PORT);
+
+       return 1;
+}
+
+char _license[] SEC("license") = "GPL";

diff --git a/tools/testing/selftests/bpf/progs/bind6_prog.c b/tools/testing/selftests/bpf/progs/bind6_prog.c
new file mode 100644 (file)
index 0000000..16da1cf
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/bind6_prog.c
@@ -0,0 +1,88 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <string.h>
+
+#include <linux/stddef.h>
+#include <linux/bpf.h>
+#include <linux/in.h>
+#include <linux/in6.h>
+#include <sys/socket.h>
+#include <netinet/tcp.h>
+#include <linux/if.h>
+#include <errno.h>
+
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_endian.h>
+
+#define SERV6_IP_0             0xfaceb00c /* face:b00c:1234:5678::abcd */
+#define SERV6_IP_1             0x12345678
+#define SERV6_IP_2             0x00000000
+#define SERV6_IP_3             0x0000abcd
+#define SERV6_PORT             6060
+#define SERV6_REWRITE_IP_0     0x00000000
+#define SERV6_REWRITE_IP_1     0x00000000
+#define SERV6_REWRITE_IP_2     0x00000000
+#define SERV6_REWRITE_IP_3     0x00000001
+#define SERV6_REWRITE_PORT     6666
+
+SEC("cgroup/bind6")
+int bind_v6_prog(struct bpf_sock_addr *ctx)
+{
+       struct bpf_sock *sk;
+       __u32 user_ip6;
+       __u16 user_port;
+       int i;
+
+       sk = ctx->sk;
+       if (!sk)
+               return 0;
+
+       if (sk->family != AF_INET6)
+               return 0;
+
+       if (ctx->type != SOCK_STREAM && ctx->type != SOCK_DGRAM)
+               return 0;
+
+       if (ctx->user_ip6[0] != bpf_htonl(SERV6_IP_0) ||
+           ctx->user_ip6[1] != bpf_htonl(SERV6_IP_1) ||
+           ctx->user_ip6[2] != bpf_htonl(SERV6_IP_2) ||
+           ctx->user_ip6[3] != bpf_htonl(SERV6_IP_3) ||
+           ctx->user_port != bpf_htons(SERV6_PORT))
+               return 0;
+
+       // u8 narrow loads:
+       for (i = 0; i < 4; i++) {
+               user_ip6 = 0;
+               user_ip6 |= ((volatile __u8 *)&ctx->user_ip6[i])[0] << 0;
+               user_ip6 |= ((volatile __u8 *)&ctx->user_ip6[i])[1] << 8;
+               user_ip6 |= ((volatile __u8 *)&ctx->user_ip6[i])[2] << 16;
+               user_ip6 |= ((volatile __u8 *)&ctx->user_ip6[i])[3] << 24;
+               if (ctx->user_ip6[i] != user_ip6)
+                       return 0;
+       }
+
+       user_port = 0;
+       user_port |= ((volatile __u8 *)&ctx->user_port)[0] << 0;
+       user_port |= ((volatile __u8 *)&ctx->user_port)[1] << 8;
+       if (ctx->user_port != user_port)
+               return 0;
+
+       // u16 narrow loads:
+       for (i = 0; i < 4; i++) {
+               user_ip6 = 0;
+               user_ip6 |= ((volatile __u16 *)&ctx->user_ip6[i])[0] << 0;
+               user_ip6 |= ((volatile __u16 *)&ctx->user_ip6[i])[1] << 16;
+               if (ctx->user_ip6[i] != user_ip6)
+                       return 0;
+       }
+
+       ctx->user_ip6[0] = bpf_htonl(SERV6_REWRITE_IP_0);
+       ctx->user_ip6[1] = bpf_htonl(SERV6_REWRITE_IP_1);
+       ctx->user_ip6[2] = bpf_htonl(SERV6_REWRITE_IP_2);
+       ctx->user_ip6[3] = bpf_htonl(SERV6_REWRITE_IP_3);
+       ctx->user_port = bpf_htons(SERV6_REWRITE_PORT);
+
+       return 1;
+}
+
+char _license[] SEC("license") = "GPL";

diff --git a/tools/testing/selftests/bpf/test_sock_addr.c b/tools/testing/selftests/bpf/test_sock_addr.c
index b8c72c1..dcb83ab 100644 (file)
--- a/tools/testing/selftests/bpf/test_sock_addr.c
+++ b/tools/testing/selftests/bpf/test_sock_addr.c
@@ -31,6 +31,8 @@
 #define CONNECT6_PROG_PATH     "./connect6_prog.o"
 #define SENDMSG4_PROG_PATH     "./sendmsg4_prog.o"
 #define SENDMSG6_PROG_PATH     "./sendmsg6_prog.o"
+#define BIND4_PROG_PATH                "./bind4_prog.o"
+#define BIND6_PROG_PATH                "./bind6_prog.o"
 
 #define SERV4_IP               "192.168.1.254"
 #define SERV4_REWRITE_IP       "127.0.0.1"
@@ -660,190 +662,6 @@ static int load_insns(const struct sock_addr_test *test,
        return ret;
 }
 
-/* [1] These testing programs try to read different context fields, including
- * narrow loads of different sizes from user_ip4 and user_ip6, and write to
- * those allowed to be overridden.
- *
- * [2] BPF_LD_IMM64 & BPF_JMP_REG are used below whenever there is a need to
- * compare a register with unsigned 32bit integer. BPF_JMP_IMM can't be used
- * in such cases since it accepts only _signed_ 32bit integer as IMM
- * argument. Also note that BPF_LD_IMM64 contains 2 instructions what matters
- * to count jumps properly.
- */
-
-static int bind4_prog_load(const struct sock_addr_test *test)
-{
-       union {
-               uint8_t u4_addr8[4];
-               uint16_t u4_addr16[2];
-               uint32_t u4_addr32;
-       } ip4, port;
-       struct sockaddr_in addr4_rw;
-
-       if (inet_pton(AF_INET, SERV4_IP, (void *)&ip4) != 1) {
-               log_err("Invalid IPv4: %s", SERV4_IP);
-               return -1;
-       }
-
-       port.u4_addr32 = htons(SERV4_PORT);
-
-       if (mk_sockaddr(AF_INET, SERV4_REWRITE_IP, SERV4_REWRITE_PORT,
-                       (struct sockaddr *)&addr4_rw, sizeof(addr4_rw)) == -1)
-               return -1;
-
-       /* See [1]. */
-       struct bpf_insn insns[] = {
-               BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
-
-               /* if (sk.family == AF_INET && */
-               BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
-                           offsetof(struct bpf_sock_addr, family)),
-               BPF_JMP_IMM(BPF_JNE, BPF_REG_7, AF_INET, 32),
-
-               /*     (sk.type == SOCK_DGRAM || sk.type == SOCK_STREAM) && */
-               BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
-                           offsetof(struct bpf_sock_addr, type)),
-               BPF_JMP_IMM(BPF_JNE, BPF_REG_7, SOCK_DGRAM, 1),
-               BPF_JMP_A(1),
-               BPF_JMP_IMM(BPF_JNE, BPF_REG_7, SOCK_STREAM, 28),
-
-               /*     1st_byte_of_user_ip4 == expected && */
-               BPF_LDX_MEM(BPF_B, BPF_REG_7, BPF_REG_6,
-                           offsetof(struct bpf_sock_addr, user_ip4)),
-               BPF_JMP_IMM(BPF_JNE, BPF_REG_7, ip4.u4_addr8[0], 26),
-
-               /*     2nd_byte_of_user_ip4 == expected && */
-               BPF_LDX_MEM(BPF_B, BPF_REG_7, BPF_REG_6,
-                           offsetof(struct bpf_sock_addr, user_ip4) + 1),
-               BPF_JMP_IMM(BPF_JNE, BPF_REG_7, ip4.u4_addr8[1], 24),
-
-               /*     3rd_byte_of_user_ip4 == expected && */
-               BPF_LDX_MEM(BPF_B, BPF_REG_7, BPF_REG_6,
-                           offsetof(struct bpf_sock_addr, user_ip4) + 2),
-               BPF_JMP_IMM(BPF_JNE, BPF_REG_7, ip4.u4_addr8[2], 22),
-
-               /*     4th_byte_of_user_ip4 == expected && */
-               BPF_LDX_MEM(BPF_B, BPF_REG_7, BPF_REG_6,
-                           offsetof(struct bpf_sock_addr, user_ip4) + 3),
-               BPF_JMP_IMM(BPF_JNE, BPF_REG_7, ip4.u4_addr8[3], 20),
-
-               /*     1st_half_of_user_ip4 == expected && */
-               BPF_LDX_MEM(BPF_H, BPF_REG_7, BPF_REG_6,
-                           offsetof(struct bpf_sock_addr, user_ip4)),
-               BPF_JMP_IMM(BPF_JNE, BPF_REG_7, ip4.u4_addr16[0], 18),
-
-               /*     2nd_half_of_user_ip4 == expected && */
-               BPF_LDX_MEM(BPF_H, BPF_REG_7, BPF_REG_6,
-                           offsetof(struct bpf_sock_addr, user_ip4) + 2),
-               BPF_JMP_IMM(BPF_JNE, BPF_REG_7, ip4.u4_addr16[1], 16),
-
-               /*     whole_user_ip4 == expected && */
-               BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
-                           offsetof(struct bpf_sock_addr, user_ip4)),
-               BPF_LD_IMM64(BPF_REG_8, ip4.u4_addr32), /* See [2]. */
-               BPF_JMP_REG(BPF_JNE, BPF_REG_7, BPF_REG_8, 12),
-
-               /*     1st_byte_of_user_port == expected && */
-               BPF_LDX_MEM(BPF_B, BPF_REG_7, BPF_REG_6,
-                           offsetof(struct bpf_sock_addr, user_port)),
-               BPF_JMP_IMM(BPF_JNE, BPF_REG_7, port.u4_addr8[0], 10),
-
-               /*     1st_half_of_user_port == expected && */
-               BPF_LDX_MEM(BPF_H, BPF_REG_7, BPF_REG_6,
-                           offsetof(struct bpf_sock_addr, user_port)),
-               BPF_JMP_IMM(BPF_JNE, BPF_REG_7, port.u4_addr16[0], 8),
-
-               /*     user_port == expected) { */
-               BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
-                           offsetof(struct bpf_sock_addr, user_port)),
-               BPF_LD_IMM64(BPF_REG_8, port.u4_addr32), /* See [2]. */
-               BPF_JMP_REG(BPF_JNE, BPF_REG_7, BPF_REG_8, 4),
-
-               /*      user_ip4 = addr4_rw.sin_addr */
-               BPF_MOV32_IMM(BPF_REG_7, addr4_rw.sin_addr.s_addr),
-               BPF_STX_MEM(BPF_W, BPF_REG_6, BPF_REG_7,
-                           offsetof(struct bpf_sock_addr, user_ip4)),
-
-               /*      user_port = addr4_rw.sin_port */
-               BPF_MOV32_IMM(BPF_REG_7, addr4_rw.sin_port),
-               BPF_STX_MEM(BPF_W, BPF_REG_6, BPF_REG_7,
-                           offsetof(struct bpf_sock_addr, user_port)),
-               /* } */
-
-               /* return 1 */
-               BPF_MOV64_IMM(BPF_REG_0, 1),
-               BPF_EXIT_INSN(),
-       };
-
-       return load_insns(test, insns, sizeof(insns) / sizeof(struct bpf_insn));
-}
-
-static int bind6_prog_load(const struct sock_addr_test *test)
-{
-       struct sockaddr_in6 addr6_rw;
-       struct in6_addr ip6;
-
-       if (inet_pton(AF_INET6, SERV6_IP, (void *)&ip6) != 1) {
-               log_err("Invalid IPv6: %s", SERV6_IP);
-               return -1;
-       }
-
-       if (mk_sockaddr(AF_INET6, SERV6_REWRITE_IP, SERV6_REWRITE_PORT,
-                       (struct sockaddr *)&addr6_rw, sizeof(addr6_rw)) == -1)
-               return -1;
-
-       /* See [1]. */
-       struct bpf_insn insns[] = {
-               BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
-
-               /* if (sk.family == AF_INET6 && */
-               BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
-                           offsetof(struct bpf_sock_addr, family)),
-               BPF_JMP_IMM(BPF_JNE, BPF_REG_7, AF_INET6, 18),
-
-               /*            5th_byte_of_user_ip6 == expected && */
-               BPF_LDX_MEM(BPF_B, BPF_REG_7, BPF_REG_6,
-                           offsetof(struct bpf_sock_addr, user_ip6[1])),
-               BPF_JMP_IMM(BPF_JNE, BPF_REG_7, ip6.s6_addr[4], 16),
-
-               /*            3rd_half_of_user_ip6 == expected && */
-               BPF_LDX_MEM(BPF_H, BPF_REG_7, BPF_REG_6,
-                           offsetof(struct bpf_sock_addr, user_ip6[1])),
-               BPF_JMP_IMM(BPF_JNE, BPF_REG_7, ip6.s6_addr16[2], 14),
-
-               /*            last_word_of_user_ip6 == expected) { */
-               BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
-                           offsetof(struct bpf_sock_addr, user_ip6[3])),
-               BPF_LD_IMM64(BPF_REG_8, ip6.s6_addr32[3]),  /* See [2]. */
-               BPF_JMP_REG(BPF_JNE, BPF_REG_7, BPF_REG_8, 10),
-
-
-#define STORE_IPV6_WORD(N)                                                    \
-               BPF_MOV32_IMM(BPF_REG_7, addr6_rw.sin6_addr.s6_addr32[N]),     \
-               BPF_STX_MEM(BPF_W, BPF_REG_6, BPF_REG_7,                       \
-                           offsetof(struct bpf_sock_addr, user_ip6[N]))
-
-               /*      user_ip6 = addr6_rw.sin6_addr */
-               STORE_IPV6_WORD(0),
-               STORE_IPV6_WORD(1),
-               STORE_IPV6_WORD(2),
-               STORE_IPV6_WORD(3),
-
-               /*      user_port = addr6_rw.sin6_port */
-               BPF_MOV32_IMM(BPF_REG_7, addr6_rw.sin6_port),
-               BPF_STX_MEM(BPF_W, BPF_REG_6, BPF_REG_7,
-                           offsetof(struct bpf_sock_addr, user_port)),
-
-               /* } */
-
-               /* return 1 */
-               BPF_MOV64_IMM(BPF_REG_0, 1),
-               BPF_EXIT_INSN(),
-       };
-
-       return load_insns(test, insns, sizeof(insns) / sizeof(struct bpf_insn));
-}
-
 static int load_path(const struct sock_addr_test *test, const char *path)
 {
        struct bpf_prog_load_attr attr;
@@ -865,6 +683,16 @@ static int load_path(const struct sock_addr_test *test, const char *path)
        return prog_fd;
 }
 
+static int bind4_prog_load(const struct sock_addr_test *test)
+{
+       return load_path(test, BIND4_PROG_PATH);
+}
+
+static int bind6_prog_load(const struct sock_addr_test *test)
+{
+       return load_path(test, BIND6_PROG_PATH);
+}
+
 static int connect4_prog_load(const struct sock_addr_test *test)
 {
        return load_path(test, CONNECT4_PROG_PATH);