From b13b8787c95c156b093305e9f006a6fb7d9119b1 Mon Sep 17 00:00:00 2001 From: Andrey Ignatov Date: Wed, 7 Nov 2018 13:36:07 -0800 Subject: [PATCH] bpf: Fix IPv6 dport byte order in bpf_sk_lookup_udp Lookup functions in sk_lookup have different expectations about byte order of provided arguments. Specifically __inet_lookup, __udp4_lib_lookup and __udp6_lib_lookup expect dport to be in network byte order and do ntohs(dport) internally. At the same time __inet6_lookup expects dport to be in host byte order and correspondingly name the argument hnum. sk_lookup works correctly with __inet_lookup, __udp4_lib_lookup and __inet6_lookup with regard to dport. But in __udp6_lib_lookup case it uses host instead of expected network byte order. It makes result returned by bpf_sk_lookup_udp for IPv6 incorrect. The patch fixes byte order of dport passed to __udp6_lib_lookup. Originally sk_lookup properly handled UDPv6, but not TCPv6. 5ef0ae84f02a fixes TCPv6 but breaks UDPv6. Fixes: 5ef0ae84f02a ("bpf: Fix IPv6 dport byte-order in bpf_sk_lookup") Signed-off-by: Andrey Ignatov Acked-by: Joe Stringer Acked-by: Martin KaFai Lau Signed-off-by: Daniel Borkmann --- net/core/filter.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/net/core/filter.c b/net/core/filter.c index e521c5ebc7d1..9a1327eb25fa 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -4852,18 +4852,17 @@ static struct sock *sk_lookup(struct net *net, struct bpf_sock_tuple *tuple, } else { struct in6_addr *src6 = (struct in6_addr *)&tuple->ipv6.saddr; struct in6_addr *dst6 = (struct in6_addr *)&tuple->ipv6.daddr; - u16 hnum = ntohs(tuple->ipv6.dport); int sdif = inet6_sdif(skb); if (proto == IPPROTO_TCP) sk = __inet6_lookup(net, &tcp_hashinfo, skb, 0, src6, tuple->ipv6.sport, - dst6, hnum, + dst6, ntohs(tuple->ipv6.dport), dif, sdif, &refcounted); else if (likely(ipv6_bpf_stub)) sk = ipv6_bpf_stub->udp6_lib_lookup(net, src6, tuple->ipv6.sport, - dst6, hnum, + dst6, tuple->ipv6.dport, dif, sdif, &udp_table, skb); #endif