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| author |   Nikita V. Shirokov <tehnerd@fb.com> | 2018-08-30 07:51:53 -0700 |
|---|---|---|
| committer |   Daniel Borkmann <daniel@iogearbox.net> | 2018-09-01 01:35:59 +0200 |
| commit | 1e215300f1384072c62459a1c194a08dbe05ff2c (patch) | |
| tree | c6cf00bf6e1509ebc1e829952ff8712ce067baaa | |
| parent | xdp: remove redundant variable 'headroom' (diff) | |
| download | linux-dev-1e215300f1384072c62459a1c194a08dbe05ff2c.tar.xz linux-dev-1e215300f1384072c62459a1c194a08dbe05ff2c.zip | |
bpf: add TCP_SAVE_SYN/TCP_SAVED_SYN options for bpf_(set|get)sockopt
Adding support for two new bpf get/set sockopts: TCP_SAVE_SYN (set)
and TCP_SAVED_SYN (get). This would allow for bpf program to build
logic based on data from ingress SYN packet (e.g. doing tcp's tos/
tclass reflection (see sample prog)) and do it transparently from
userspace program point of view.
Signed-off-by: Nikita V. Shirokov <tehnerd@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| -rw-r--r-- | net/core/filter.c | 25 |
1 files changed, 21 insertions, 4 deletions
diff --git a/net/core/filter.c b/net/core/filter.c index c25eb36f1320..feb578506009 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -4007,6 +4007,12 @@ BPF_CALL_5(bpf_setsockopt, struct bpf_sock_ops_kern *, bpf_sock, tp->snd_ssthresh = val; } break; + case TCP_SAVE_SYN: + if (val < 0 || val > 1) + ret = -EINVAL; + else + tp->save_syn = val; + break; default: ret = -EINVAL; } @@ -4032,21 +4038,32 @@ static const struct bpf_func_proto bpf_setsockopt_proto = { BPF_CALL_5(bpf_getsockopt, struct bpf_sock_ops_kern *, bpf_sock, int, level, int, optname, char *, optval, int, optlen) { + struct inet_connection_sock *icsk; struct sock *sk = bpf_sock->sk; + struct tcp_sock *tp; if (!sk_fullsock(sk)) goto err_clear; - #ifdef CONFIG_INET if (level == SOL_TCP && sk->sk_prot->getsockopt == tcp_getsockopt) { - if (optname == TCP_CONGESTION) { - struct inet_connection_sock *icsk = inet_csk(sk); + switch (optname) { + case TCP_CONGESTION: + icsk = inet_csk(sk); if (!icsk->icsk_ca_ops || optlen <= 1) goto err_clear; strncpy(optval, icsk->icsk_ca_ops->name, optlen); optval[optlen - 1] = 0; - } else { + break; + case TCP_SAVED_SYN: + tp = tcp_sk(sk); + + if (optlen <= 0 || !tp->saved_syn || + optlen > tp->saved_syn[0]) + goto err_clear; + memcpy(optval, tp->saved_syn + 1, optlen); + break; + default: goto err_clear; } } else if (level == SOL_IP) { |