diff options
author | Martin KaFai Lau <kafai@fb.com> | 2019-02-09 23:22:24 -0800 |
---|---|---|
committer | Alexei Starovoitov <ast@kernel.org> | 2019-02-10 19:46:17 -0800 |
commit | 655a51e536c09d15ffa3603b1b6fce2b45b85a1f (patch) | |
tree | c918f6f95d890735a86370630fd7791f2a5a5360 /include/linux | |
parent | bpf: Refactor sock_ops_convert_ctx_access (diff) | |
download | linux-dev-655a51e536c09d15ffa3603b1b6fce2b45b85a1f.tar.xz linux-dev-655a51e536c09d15ffa3603b1b6fce2b45b85a1f.zip |
bpf: Add struct bpf_tcp_sock and BPF_FUNC_tcp_sock
This patch adds a helper function BPF_FUNC_tcp_sock and it
is currently available for cg_skb and sched_(cls|act):
struct bpf_tcp_sock *bpf_tcp_sock(struct bpf_sock *sk);
int cg_skb_foo(struct __sk_buff *skb) {
struct bpf_tcp_sock *tp;
struct bpf_sock *sk;
__u32 snd_cwnd;
sk = skb->sk;
if (!sk)
return 1;
tp = bpf_tcp_sock(sk);
if (!tp)
return 1;
snd_cwnd = tp->snd_cwnd;
/* ... */
return 1;
}
A 'struct bpf_tcp_sock' is also added to the uapi bpf.h to provide
read-only access. bpf_tcp_sock has all the existing tcp_sock's fields
that has already been exposed by the bpf_sock_ops.
i.e. no new tcp_sock's fields are exposed in bpf.h.
This helper returns a pointer to the tcp_sock. If it is not a tcp_sock
or it cannot be traced back to a tcp_sock by sk_to_full_sk(), it
returns NULL. Hence, the caller needs to check for NULL before
accessing it.
The current use case is to expose members from tcp_sock
to allow a cg_skb_bpf_prog to provide per cgroup traffic
policing/shaping.
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'include/linux')
-rw-r--r-- | include/linux/bpf.h | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/include/linux/bpf.h b/include/linux/bpf.h index a60463b45b54..7f58828755fd 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -204,6 +204,7 @@ enum bpf_return_type { RET_PTR_TO_MAP_VALUE, /* returns a pointer to map elem value */ RET_PTR_TO_MAP_VALUE_OR_NULL, /* returns a pointer to map elem value or NULL */ RET_PTR_TO_SOCKET_OR_NULL, /* returns a pointer to a socket or NULL */ + RET_PTR_TO_TCP_SOCK_OR_NULL, /* returns a pointer to a tcp_sock or NULL */ }; /* eBPF function prototype used by verifier to allow BPF_CALLs from eBPF programs @@ -259,6 +260,8 @@ enum bpf_reg_type { PTR_TO_SOCKET_OR_NULL, /* reg points to struct bpf_sock or NULL */ PTR_TO_SOCK_COMMON, /* reg points to sock_common */ PTR_TO_SOCK_COMMON_OR_NULL, /* reg points to sock_common or NULL */ + PTR_TO_TCP_SOCK, /* reg points to struct tcp_sock */ + PTR_TO_TCP_SOCK_OR_NULL, /* reg points to struct tcp_sock or NULL */ }; /* The information passed from prog-specific *_is_valid_access @@ -956,4 +959,31 @@ static inline u32 bpf_sock_convert_ctx_access(enum bpf_access_type type, } #endif +#ifdef CONFIG_INET +bool bpf_tcp_sock_is_valid_access(int off, int size, enum bpf_access_type type, + struct bpf_insn_access_aux *info); + +u32 bpf_tcp_sock_convert_ctx_access(enum bpf_access_type type, + const struct bpf_insn *si, + struct bpf_insn *insn_buf, + struct bpf_prog *prog, + u32 *target_size); +#else +static inline bool bpf_tcp_sock_is_valid_access(int off, int size, + enum bpf_access_type type, + struct bpf_insn_access_aux *info) +{ + return false; +} + +static inline u32 bpf_tcp_sock_convert_ctx_access(enum bpf_access_type type, + const struct bpf_insn *si, + struct bpf_insn *insn_buf, + struct bpf_prog *prog, + u32 *target_size) +{ + return 0; +} +#endif /* CONFIG_INET */ + #endif /* _LINUX_BPF_H */ |