From 1122702f02678597c4f1c7d316365ef502aafe08 Mon Sep 17 00:00:00 2001 From: Jakub Sitnicki Date: Fri, 17 Jul 2020 12:35:27 +0200 Subject: inet6: Run SK_LOOKUP BPF program on socket lookup Following ipv4 stack changes, run a BPF program attached to netns before looking up a listening socket. Program can return a listening socket to use as result of socket lookup, fail the lookup, or take no action. Suggested-by: Marek Majkowski Signed-off-by: Jakub Sitnicki Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20200717103536.397595-7-jakub@cloudflare.com --- net/ipv6/inet6_hashtables.c | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) (limited to 'net/ipv6') diff --git a/net/ipv6/inet6_hashtables.c b/net/ipv6/inet6_hashtables.c index 03942eef8ab6..2d3add9e6116 100644 --- a/net/ipv6/inet6_hashtables.c +++ b/net/ipv6/inet6_hashtables.c @@ -21,6 +21,8 @@ #include #include +extern struct inet_hashinfo tcp_hashinfo; + u32 inet6_ehashfn(const struct net *net, const struct in6_addr *laddr, const u16 lport, const struct in6_addr *faddr, const __be16 fport) @@ -159,6 +161,31 @@ static struct sock *inet6_lhash2_lookup(struct net *net, return result; } +static inline struct sock *inet6_lookup_run_bpf(struct net *net, + struct inet_hashinfo *hashinfo, + struct sk_buff *skb, int doff, + const struct in6_addr *saddr, + const __be16 sport, + const struct in6_addr *daddr, + const u16 hnum) +{ + struct sock *sk, *reuse_sk; + bool no_reuseport; + + if (hashinfo != &tcp_hashinfo) + return NULL; /* only TCP is supported */ + + no_reuseport = bpf_sk_lookup_run_v6(net, IPPROTO_TCP, + saddr, sport, daddr, hnum, &sk); + if (no_reuseport || IS_ERR_OR_NULL(sk)) + return sk; + + reuse_sk = lookup_reuseport(net, sk, skb, doff, saddr, sport, daddr, hnum); + if (reuse_sk) + sk = reuse_sk; + return sk; +} + struct sock *inet6_lookup_listener(struct net *net, struct inet_hashinfo *hashinfo, struct sk_buff *skb, int doff, @@ -170,6 +197,14 @@ struct sock *inet6_lookup_listener(struct net *net, struct sock *result = NULL; unsigned int hash2; + /* Lookup redirect from BPF */ + if (static_branch_unlikely(&bpf_sk_lookup_enabled)) { + result = inet6_lookup_run_bpf(net, hashinfo, skb, doff, + saddr, sport, daddr, hnum); + if (result) + goto done; + } + hash2 = ipv6_portaddr_hash(net, daddr, hnum); ilb2 = inet_lhash2_bucket(hashinfo, hash2); -- cgit v1.2.3