bpf: Refactor sock_ops_convert_ctx_access

The next patch will introduce a new "struct bpf_tcp_sock" which
exposes the same tcp_sock's fields already exposed in
"struct bpf_sock_ops".

This patch refactor the existing convert_ctx_access() codes for
"struct bpf_sock_ops" to get them ready to be reused for
"struct bpf_tcp_sock".  The "rtt_min" is not refactored
in this patch because its handling is different from other
fields.

The SOCK_OPS_GET_TCP_SOCK_FIELD is new. All other SOCK_OPS_XXX_FIELD
changes are code move only.

Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

diff --git a/net/core/filter.c b/net/core/filter.c
index 01bb64b..c0d7b9e 100644 (file)
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -5030,6 +5030,54 @@ static const struct bpf_func_proto bpf_lwt_seg6_adjust_srh_proto = {
 };
 #endif /* CONFIG_IPV6_SEG6_BPF */
 
+#define CONVERT_COMMON_TCP_SOCK_FIELDS(md_type, CONVERT)               \
+do {                                                                   \
+       switch (si->off) {                                              \
+       case offsetof(md_type, snd_cwnd):                               \
+               CONVERT(snd_cwnd); break;                               \
+       case offsetof(md_type, srtt_us):                                \
+               CONVERT(srtt_us); break;                                \
+       case offsetof(md_type, snd_ssthresh):                           \
+               CONVERT(snd_ssthresh); break;                           \
+       case offsetof(md_type, rcv_nxt):                                \
+               CONVERT(rcv_nxt); break;                                \
+       case offsetof(md_type, snd_nxt):                                \
+               CONVERT(snd_nxt); break;                                \
+       case offsetof(md_type, snd_una):                                \
+               CONVERT(snd_una); break;                                \
+       case offsetof(md_type, mss_cache):                              \
+               CONVERT(mss_cache); break;                              \
+       case offsetof(md_type, ecn_flags):                              \
+               CONVERT(ecn_flags); break;                              \
+       case offsetof(md_type, rate_delivered):                         \
+               CONVERT(rate_delivered); break;                         \
+       case offsetof(md_type, rate_interval_us):                       \
+               CONVERT(rate_interval_us); break;                       \
+       case offsetof(md_type, packets_out):                            \
+               CONVERT(packets_out); break;                            \
+       case offsetof(md_type, retrans_out):                            \
+               CONVERT(retrans_out); break;                            \
+       case offsetof(md_type, total_retrans):                          \
+               CONVERT(total_retrans); break;                          \
+       case offsetof(md_type, segs_in):                                \
+               CONVERT(segs_in); break;                                \
+       case offsetof(md_type, data_segs_in):                           \
+               CONVERT(data_segs_in); break;                           \
+       case offsetof(md_type, segs_out):                               \
+               CONVERT(segs_out); break;                               \
+       case offsetof(md_type, data_segs_out):                          \
+               CONVERT(data_segs_out); break;                          \
+       case offsetof(md_type, lost_out):                               \
+               CONVERT(lost_out); break;                               \
+       case offsetof(md_type, sacked_out):                             \
+               CONVERT(sacked_out); break;                             \
+       case offsetof(md_type, bytes_received):                         \
+               CONVERT(bytes_received); break;                         \
+       case offsetof(md_type, bytes_acked):                            \
+               CONVERT(bytes_acked); break;                            \
+       }                                                               \
+} while (0)
+
 #ifdef CONFIG_INET
 static struct sock *sk_lookup(struct net *net, struct bpf_sock_tuple *tuple,
                              int dif, int sdif, u8 family, u8 proto)
@@ -7196,6 +7244,85 @@ static u32 sock_ops_convert_ctx_access(enum bpf_access_type type,
        struct bpf_insn *insn = insn_buf;
        int off;
 
+/* Helper macro for adding read access to tcp_sock or sock fields. */
+#define SOCK_OPS_GET_FIELD(BPF_FIELD, OBJ_FIELD, OBJ)                        \
+       do {                                                                  \
+               BUILD_BUG_ON(FIELD_SIZEOF(OBJ, OBJ_FIELD) >                   \
+                            FIELD_SIZEOF(struct bpf_sock_ops, BPF_FIELD));   \
+               *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(                       \
+                                               struct bpf_sock_ops_kern,     \
+                                               is_fullsock),                 \
+                                     si->dst_reg, si->src_reg,               \
+                                     offsetof(struct bpf_sock_ops_kern,      \
+                                              is_fullsock));                 \
+               *insn++ = BPF_JMP_IMM(BPF_JEQ, si->dst_reg, 0, 2);            \
+               *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(                       \
+                                               struct bpf_sock_ops_kern, sk),\
+                                     si->dst_reg, si->src_reg,               \
+                                     offsetof(struct bpf_sock_ops_kern, sk));\
+               *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(OBJ,                   \
+                                                      OBJ_FIELD),            \
+                                     si->dst_reg, si->dst_reg,               \
+                                     offsetof(OBJ, OBJ_FIELD));              \
+       } while (0)
+
+#define SOCK_OPS_GET_TCP_SOCK_FIELD(FIELD) \
+               SOCK_OPS_GET_FIELD(FIELD, FIELD, struct tcp_sock)
+
+/* Helper macro for adding write access to tcp_sock or sock fields.
+ * The macro is called with two registers, dst_reg which contains a pointer
+ * to ctx (context) and src_reg which contains the value that should be
+ * stored. However, we need an additional register since we cannot overwrite
+ * dst_reg because it may be used later in the program.
+ * Instead we "borrow" one of the other register. We first save its value
+ * into a new (temp) field in bpf_sock_ops_kern, use it, and then restore
+ * it at the end of the macro.
+ */
+#define SOCK_OPS_SET_FIELD(BPF_FIELD, OBJ_FIELD, OBJ)                        \
+       do {                                                                  \
+               int reg = BPF_REG_9;                                          \
+               BUILD_BUG_ON(FIELD_SIZEOF(OBJ, OBJ_FIELD) >                   \
+                            FIELD_SIZEOF(struct bpf_sock_ops, BPF_FIELD));   \
+               if (si->dst_reg == reg || si->src_reg == reg)                 \
+                       reg--;                                                \
+               if (si->dst_reg == reg || si->src_reg == reg)                 \
+                       reg--;                                                \
+               *insn++ = BPF_STX_MEM(BPF_DW, si->dst_reg, reg,               \
+                                     offsetof(struct bpf_sock_ops_kern,      \
+                                              temp));                        \
+               *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(                       \
+                                               struct bpf_sock_ops_kern,     \
+                                               is_fullsock),                 \
+                                     reg, si->dst_reg,                       \
+                                     offsetof(struct bpf_sock_ops_kern,      \
+                                              is_fullsock));                 \
+               *insn++ = BPF_JMP_IMM(BPF_JEQ, reg, 0, 2);                    \
+               *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(                       \
+                                               struct bpf_sock_ops_kern, sk),\
+                                     reg, si->dst_reg,                       \
+                                     offsetof(struct bpf_sock_ops_kern, sk));\
+               *insn++ = BPF_STX_MEM(BPF_FIELD_SIZEOF(OBJ, OBJ_FIELD),       \
+                                     reg, si->src_reg,                       \
+                                     offsetof(OBJ, OBJ_FIELD));              \
+               *insn++ = BPF_LDX_MEM(BPF_DW, reg, si->dst_reg,               \
+                                     offsetof(struct bpf_sock_ops_kern,      \
+                                              temp));                        \
+       } while (0)
+
+#define SOCK_OPS_GET_OR_SET_FIELD(BPF_FIELD, OBJ_FIELD, OBJ, TYPE)           \
+       do {                                                                  \
+               if (TYPE == BPF_WRITE)                                        \
+                       SOCK_OPS_SET_FIELD(BPF_FIELD, OBJ_FIELD, OBJ);        \
+               else                                                          \
+                       SOCK_OPS_GET_FIELD(BPF_FIELD, OBJ_FIELD, OBJ);        \
+       } while (0)
+
+       CONVERT_COMMON_TCP_SOCK_FIELDS(struct bpf_sock_ops,
+                                      SOCK_OPS_GET_TCP_SOCK_FIELD);
+
+       if (insn > insn_buf)
+               return insn - insn_buf;
+
        switch (si->off) {
        case offsetof(struct bpf_sock_ops, op) ...
             offsetof(struct bpf_sock_ops, replylong[3]):
@@ -7353,175 +7480,15 @@ static u32 sock_ops_convert_ctx_access(enum bpf_access_type type,
                                      FIELD_SIZEOF(struct minmax_sample, t));
                break;
 
-/* Helper macro for adding read access to tcp_sock or sock fields. */
-#define SOCK_OPS_GET_FIELD(BPF_FIELD, OBJ_FIELD, OBJ)                        \
-       do {                                                                  \
-               BUILD_BUG_ON(FIELD_SIZEOF(OBJ, OBJ_FIELD) >                   \
-                            FIELD_SIZEOF(struct bpf_sock_ops, BPF_FIELD));   \
-               *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(                       \
-                                               struct bpf_sock_ops_kern,     \
-                                               is_fullsock),                 \
-                                     si->dst_reg, si->src_reg,               \
-                                     offsetof(struct bpf_sock_ops_kern,      \
-                                              is_fullsock));                 \
-               *insn++ = BPF_JMP_IMM(BPF_JEQ, si->dst_reg, 0, 2);            \
-               *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(                       \
-                                               struct bpf_sock_ops_kern, sk),\
-                                     si->dst_reg, si->src_reg,               \
-                                     offsetof(struct bpf_sock_ops_kern, sk));\
-               *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(OBJ,                   \
-                                                      OBJ_FIELD),            \
-                                     si->dst_reg, si->dst_reg,               \
-                                     offsetof(OBJ, OBJ_FIELD));              \
-       } while (0)
-
-/* Helper macro for adding write access to tcp_sock or sock fields.
- * The macro is called with two registers, dst_reg which contains a pointer
- * to ctx (context) and src_reg which contains the value that should be
- * stored. However, we need an additional register since we cannot overwrite
- * dst_reg because it may be used later in the program.
- * Instead we "borrow" one of the other register. We first save its value
- * into a new (temp) field in bpf_sock_ops_kern, use it, and then restore
- * it at the end of the macro.
- */
-#define SOCK_OPS_SET_FIELD(BPF_FIELD, OBJ_FIELD, OBJ)                        \
-       do {                                                                  \
-               int reg = BPF_REG_9;                                          \
-               BUILD_BUG_ON(FIELD_SIZEOF(OBJ, OBJ_FIELD) >                   \
-                            FIELD_SIZEOF(struct bpf_sock_ops, BPF_FIELD));   \
-               if (si->dst_reg == reg || si->src_reg == reg)                 \
-                       reg--;                                                \
-               if (si->dst_reg == reg || si->src_reg == reg)                 \
-                       reg--;                                                \
-               *insn++ = BPF_STX_MEM(BPF_DW, si->dst_reg, reg,               \
-                                     offsetof(struct bpf_sock_ops_kern,      \
-                                              temp));                        \
-               *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(                       \
-                                               struct bpf_sock_ops_kern,     \
-                                               is_fullsock),                 \
-                                     reg, si->dst_reg,                       \
-                                     offsetof(struct bpf_sock_ops_kern,      \
-                                              is_fullsock));                 \
-               *insn++ = BPF_JMP_IMM(BPF_JEQ, reg, 0, 2);                    \
-               *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(                       \
-                                               struct bpf_sock_ops_kern, sk),\
-                                     reg, si->dst_reg,                       \
-                                     offsetof(struct bpf_sock_ops_kern, sk));\
-               *insn++ = BPF_STX_MEM(BPF_FIELD_SIZEOF(OBJ, OBJ_FIELD),       \
-                                     reg, si->src_reg,                       \
-                                     offsetof(OBJ, OBJ_FIELD));              \
-               *insn++ = BPF_LDX_MEM(BPF_DW, reg, si->dst_reg,               \
-                                     offsetof(struct bpf_sock_ops_kern,      \
-                                              temp));                        \
-       } while (0)
-
-#define SOCK_OPS_GET_OR_SET_FIELD(BPF_FIELD, OBJ_FIELD, OBJ, TYPE)           \
-       do {                                                                  \
-               if (TYPE == BPF_WRITE)                                        \
-                       SOCK_OPS_SET_FIELD(BPF_FIELD, OBJ_FIELD, OBJ);        \
-               else                                                          \
-                       SOCK_OPS_GET_FIELD(BPF_FIELD, OBJ_FIELD, OBJ);        \
-       } while (0)
-
-       case offsetof(struct bpf_sock_ops, snd_cwnd):
-               SOCK_OPS_GET_FIELD(snd_cwnd, snd_cwnd, struct tcp_sock);
-               break;
-
-       case offsetof(struct bpf_sock_ops, srtt_us):
-               SOCK_OPS_GET_FIELD(srtt_us, srtt_us, struct tcp_sock);
-               break;
-
        case offsetof(struct bpf_sock_ops, bpf_sock_ops_cb_flags):
                SOCK_OPS_GET_FIELD(bpf_sock_ops_cb_flags, bpf_sock_ops_cb_flags,
                                   struct tcp_sock);
                break;
 
-       case offsetof(struct bpf_sock_ops, snd_ssthresh):
-               SOCK_OPS_GET_FIELD(snd_ssthresh, snd_ssthresh, struct tcp_sock);
-               break;
-
-       case offsetof(struct bpf_sock_ops, rcv_nxt):
-               SOCK_OPS_GET_FIELD(rcv_nxt, rcv_nxt, struct tcp_sock);
-               break;
-
-       case offsetof(struct bpf_sock_ops, snd_nxt):
-               SOCK_OPS_GET_FIELD(snd_nxt, snd_nxt, struct tcp_sock);
-               break;
-
-       case offsetof(struct bpf_sock_ops, snd_una):
-               SOCK_OPS_GET_FIELD(snd_una, snd_una, struct tcp_sock);
-               break;
-
-       case offsetof(struct bpf_sock_ops, mss_cache):
-               SOCK_OPS_GET_FIELD(mss_cache, mss_cache, struct tcp_sock);
-               break;
-
-       case offsetof(struct bpf_sock_ops, ecn_flags):
-               SOCK_OPS_GET_FIELD(ecn_flags, ecn_flags, struct tcp_sock);
-               break;
-
-       case offsetof(struct bpf_sock_ops, rate_delivered):
-               SOCK_OPS_GET_FIELD(rate_delivered, rate_delivered,
-                                  struct tcp_sock);
-               break;
-
-       case offsetof(struct bpf_sock_ops, rate_interval_us):
-               SOCK_OPS_GET_FIELD(rate_interval_us, rate_interval_us,
-                                  struct tcp_sock);
-               break;
-
-       case offsetof(struct bpf_sock_ops, packets_out):
-               SOCK_OPS_GET_FIELD(packets_out, packets_out, struct tcp_sock);
-               break;
-
-       case offsetof(struct bpf_sock_ops, retrans_out):
-               SOCK_OPS_GET_FIELD(retrans_out, retrans_out, struct tcp_sock);
-               break;
-
-       case offsetof(struct bpf_sock_ops, total_retrans):
-               SOCK_OPS_GET_FIELD(total_retrans, total_retrans,
-                                  struct tcp_sock);
-               break;
-
-       case offsetof(struct bpf_sock_ops, segs_in):
-               SOCK_OPS_GET_FIELD(segs_in, segs_in, struct tcp_sock);
-               break;
-
-       case offsetof(struct bpf_sock_ops, data_segs_in):
-               SOCK_OPS_GET_FIELD(data_segs_in, data_segs_in, struct tcp_sock);
-               break;
-
-       case offsetof(struct bpf_sock_ops, segs_out):
-               SOCK_OPS_GET_FIELD(segs_out, segs_out, struct tcp_sock);
-               break;
-
-       case offsetof(struct bpf_sock_ops, data_segs_out):
-               SOCK_OPS_GET_FIELD(data_segs_out, data_segs_out,
-                                  struct tcp_sock);
-               break;
-
-       case offsetof(struct bpf_sock_ops, lost_out):
-               SOCK_OPS_GET_FIELD(lost_out, lost_out, struct tcp_sock);
-               break;
-
-       case offsetof(struct bpf_sock_ops, sacked_out):
-               SOCK_OPS_GET_FIELD(sacked_out, sacked_out, struct tcp_sock);
-               break;
-
        case offsetof(struct bpf_sock_ops, sk_txhash):
                SOCK_OPS_GET_OR_SET_FIELD(sk_txhash, sk_txhash,
                                          struct sock, type);
                break;
-
-       case offsetof(struct bpf_sock_ops, bytes_received):
-               SOCK_OPS_GET_FIELD(bytes_received, bytes_received,
-                                  struct tcp_sock);
-               break;
-
-       case offsetof(struct bpf_sock_ops, bytes_acked):
-               SOCK_OPS_GET_FIELD(bytes_acked, bytes_acked, struct tcp_sock);
-               break;
-
        }
        return insn - insn_buf;
 }