diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c index 4e4c401e3bc6..08a188ffe070 100644 --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -864,6 +864,64 @@ discard: return 0; } +static struct sock *__udp6_lib_demux_lookup(struct net *net, + __be16 loc_port, const struct in6_addr *loc_addr, + __be16 rmt_port, const struct in6_addr *rmt_addr, + int dif) +{ + struct sock *sk; + + rcu_read_lock(); + sk = __udp6_lib_lookup(net, rmt_addr, rmt_port, loc_addr, loc_port, + dif, &udp_table, NULL); + if (sk && !atomic_inc_not_zero(&sk->sk_refcnt)) + sk = NULL; + rcu_read_unlock(); + + return sk; +} + +static void udp_v6_early_demux(struct sk_buff *skb) +{ + struct net *net = dev_net(skb->dev); + const struct udphdr *uh; + struct sock *sk; + struct dst_entry *dst; + int dif = skb->dev->ifindex; + + if (!pskb_may_pull(skb, skb_transport_offset(skb) + + sizeof(struct udphdr))) + return; + + uh = udp_hdr(skb); + + if (skb->pkt_type == PACKET_HOST) + sk = __udp6_lib_demux_lookup(net, uh->dest, + &ipv6_hdr(skb)->daddr, + uh->source, &ipv6_hdr(skb)->saddr, + dif); + else + return; + + if (!sk) + return; + + skb->sk = sk; + skb->destructor = sock_efree; + dst = READ_ONCE(sk->sk_rx_dst); + + if (dst) + dst = dst_check(dst, inet6_sk(sk)->rx_dst_cookie); + if (dst) { + if (dst->flags & DST_NOCACHE) { + if (likely(atomic_inc_not_zero(&dst->__refcnt))) + skb_dst_set(skb, dst); + } else { + skb_dst_set_noref(skb, dst); + } + } +} + static __inline__ int udpv6_rcv(struct sk_buff *skb) { return __udp6_lib_rcv(skb, &udp_table, IPPROTO_UDP); @@ -1379,6 +1437,7 @@ int compat_udpv6_getsockopt(struct sock *sk, int level, int optname, #endif static const struct inet6_protocol udpv6_protocol = { + .early_demux = udp_v6_early_demux, .handler = udpv6_rcv, .err_handler = udpv6_err, .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,