@@ -1289,7 +1289,7 @@ int udpv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel);
- dst = ip6_sk_dst_lookup_flow(sk, &fl6, final_p, 0);
+ dst = ip6_sk_dst_lookup_flow(sk, &fl6, final_p, connected);
if (IS_ERR(dst)) {
err = PTR_ERR(dst);
dst = NULL;
@@ -1314,7 +1314,7 @@ int udpv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
err = PTR_ERR(skb);
if (!IS_ERR_OR_NULL(skb))
err = udp_v6_send_skb(skb, &fl6);
- goto release_dst;
+ goto out;
}
lock_sock(sk);
@@ -1348,23 +1348,6 @@ int udpv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
err = np->recverr ? net_xmit_errno(err) : 0;
release_sock(sk);
-release_dst:
- if (dst) {
- if (connected) {
- ip6_dst_store(sk, dst,
- ipv6_addr_equal(&fl6.daddr, &sk->sk_v6_daddr) ?
- &sk->sk_v6_daddr : NULL,
-#ifdef CONFIG_IPV6_SUBTREES
- ipv6_addr_equal(&fl6.saddr, &np->saddr) ?
- &np->saddr :
-#endif
- NULL);
- } else {
- dst_release(dst);
- }
- dst = NULL;
- }
-
out:
dst_release(dst);
fl6_sock_release(flowlabel);
A new RTF_CACHE route can be created between ip6_sk_dst_lookup_flow() and ip6_dst_store() calls in udpv6_sendmsg(), when datagram sending results to ICMPV6_PKT_TOOBIG error: udp_v6_send_skb(), for example with vti6 tunnel: vti6_xmit(), get ICMPV6_PKT_TOOBIG error skb_dst_update_pmtu(), can create a RTF_CACHE clone icmpv6_send() ... udpv6_err() ip6_sk_update_pmtu() ip6_update_pmtu(), can create a RTF_CACHE clone ... ip6_datagram_dst_update() ip6_dst_store() And after commit 33c162a980fe ("ipv6: datagram: Update dst cache of a connected datagram sk during pmtu update"), the UDPv6 error handler can update socket's dst cache, but it can happen before the update in the end of udpv6_sendmsg(), preventing getting the new dst cache on the next udpv6_sendmsg() calls. In order to fix it, save dst in a connected socket only if the current socket's dst cache is invalid. The previous patch prepared ip6_sk_dst_lookup_flow() to do that with the new argument, and this patch enables it in udpv6_sendmsg(). Fixes: 33c162a980fe ("ipv6: datagram: Update dst cache of a connected datagram sk during pmtu update") Fixes: 45e4fd26683c ("ipv6: Only create RTF_CACHE routes after encountering pmtu exception") Signed-off-by: Alexey Kodanev <alexey.kodanev@oracle.com> --- net/ipv6/udp.c | 21 ++------------------- 1 file changed, 2 insertions(+), 19 deletions(-)