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authorNikita V. Shirokov <tehnerd@fb.com>2018-08-30 07:51:53 -0700
committerDaniel Borkmann <daniel@iogearbox.net>2018-08-31 13:08:49 +0200
commit9452048c79404e23f08678aec15fc04c7752923b (patch)
treec6cf00bf6e1509ebc1e829952ff8712ce067baaa
parent175eba5962b4df58431049d9942170c3324886e6 (diff)
downloadmachiattobin-xdp-9452048c79404e23f08678aec15fc04c7752923b.tar.gz
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>
-rw-r--r--net/core/filter.c25
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) {