From be2644aac3e1db02d09f45d56206bbdafca582a2 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Tue, 1 Oct 2019 10:49:06 -0700 Subject: [PATCH] tcp: add ipv6_addr_v4mapped_loopback() helper tcp_twsk_unique() has a hard coded assumption about ipv4 loopback being 127/8 Lets instead use the standard ipv4_is_loopback() method, in a new ipv6_addr_v4mapped_loopback() helper. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- include/net/ipv6.h | 5 +++++ net/ipv4/tcp_ipv4.c | 6 ++---- 2 files changed, 7 insertions(+), 4 deletions(-) diff --git a/include/net/ipv6.h b/include/net/ipv6.h index 009605c56f20..d04b7abe2a4c 100644 --- a/include/net/ipv6.h +++ b/include/net/ipv6.h @@ -696,6 +696,11 @@ static inline bool ipv6_addr_v4mapped(const struct in6_addr *a) cpu_to_be32(0x0000ffff))) == 0UL; } +static inline bool ipv6_addr_v4mapped_loopback(const struct in6_addr *a) +{ + return ipv6_addr_v4mapped(a) && ipv4_is_loopback(a->s6_addr32[3]); +} + static inline u32 ipv6_portaddr_hash(const struct net *net, const struct in6_addr *addr6, unsigned int port) diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 2ee45e3755e9..27dc3c1e9094 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -121,11 +121,9 @@ int tcp_twsk_unique(struct sock *sk, struct sock *sktw, void *twp) #if IS_ENABLED(CONFIG_IPV6) if (tw->tw_family == AF_INET6) { if (ipv6_addr_loopback(&tw->tw_v6_daddr) || - (ipv6_addr_v4mapped(&tw->tw_v6_daddr) && - (tw->tw_v6_daddr.s6_addr[12] == 127)) || + ipv6_addr_v4mapped_loopback(&tw->tw_v6_daddr) || ipv6_addr_loopback(&tw->tw_v6_rcv_saddr) || - (ipv6_addr_v4mapped(&tw->tw_v6_rcv_saddr) && - (tw->tw_v6_rcv_saddr.s6_addr[12] == 127))) + ipv6_addr_v4mapped_loopback(&tw->tw_v6_rcv_saddr)) loopback = true; } else #endif