From: Eric Dumazet <edumazet@google.com>
Date: Tue, 1 Oct 2019 10:49:06 -0700
Subject: tcp: add ipv6_addr_v4mapped_loopback() helper
Patch-mainline: v5.5-rc1
Git-commit: be2644aac3e1db02d09f45d56206bbdafca582a2
References: bsc#1154353
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 <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
include/net/ipv6.h | 5 +++++
net/ipv4/tcp_ipv4.c | 6 ++----
2 files changed, 7 insertions(+), 4 deletions(-)
--- a/include/net/ipv6.h
+++ b/include/net/ipv6.h
@@ -696,6 +696,11 @@ static inline bool ipv6_addr_v4mapped(co
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)
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -121,11 +121,9 @@ int tcp_twsk_unique(struct sock *sk, str
#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