3.16.52-rc1 review patch. If anyone has any objections, please let me know.
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From: Paolo Abeni pabeni@redhat.com
commit 7487449c86c65202b3b725c4524cb48dd65e4e6f upstream.
Currently no error is emitted, but this infrastructure will used by the next patch to allow source address validation for mcast sockets. Since early demux can do a route lookup and an ipv4 route lookup can return an error code this is consistent with the current ipv4 route infrastructure.
Signed-off-by: Paolo Abeni pabeni@redhat.com Signed-off-by: David S. Miller davem@davemloft.net [bwh: Backported to 3.16: - Drop change to net_protocol::early_demux_handler - Keep using NET_INC_STATS_BH() in ip_rcv_finish() - Fix up additional return statement in udp_v4_early_demux() - Adjust context] Signed-off-by: Ben Hutchings ben@decadent.org.uk --- --- a/include/net/protocol.h +++ b/include/net/protocol.h @@ -39,7 +39,7 @@
/* This is used to register protocols. */ struct net_protocol { - void (*early_demux)(struct sk_buff *skb); + int (*early_demux)(struct sk_buff *skb); int (*handler)(struct sk_buff *skb); void (*err_handler)(struct sk_buff *skb, u32 info); unsigned int no_policy:1, --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -350,7 +350,7 @@ void tcp_v4_err(struct sk_buff *skb, u32
void tcp_shutdown(struct sock *sk, int how);
-void tcp_v4_early_demux(struct sk_buff *skb); +int tcp_v4_early_demux(struct sk_buff *skb); int tcp_v4_rcv(struct sk_buff *skb);
int tcp_v4_tw_remember_stamp(struct inet_timewait_sock *tw); --- a/include/net/udp.h +++ b/include/net/udp.h @@ -177,7 +177,7 @@ int udp_lib_get_port(struct sock *sk, un unsigned int hash2_nulladdr);
/* net/ipv4/udp.c */ -void udp_v4_early_demux(struct sk_buff *skb); +int udp_v4_early_demux(struct sk_buff *skb); int udp_get_port(struct sock *sk, unsigned short snum, int (*saddr_cmp)(const struct sock *, const struct sock *)); --- a/net/ipv4/ip_input.c +++ b/net/ipv4/ip_input.c @@ -313,6 +313,7 @@ static int ip_rcv_finish(struct sk_buff { const struct iphdr *iph = ip_hdr(skb); struct rtable *rt; + int err;
if (sysctl_ip_early_demux && !skb_dst(skb) && skb->sk == NULL) { const struct net_protocol *ipprot; @@ -320,7 +321,9 @@ static int ip_rcv_finish(struct sk_buff
ipprot = rcu_dereference(inet_protos[protocol]); if (ipprot && ipprot->early_demux) { - ipprot->early_demux(skb); + err = ipprot->early_demux(skb); + if (unlikely(err)) + goto drop_error; /* must reload iph, skb->head might have changed */ iph = ip_hdr(skb); } @@ -331,14 +334,10 @@ static int ip_rcv_finish(struct sk_buff * how the packet travels inside Linux networking. */ if (!skb_dst(skb)) { - int err = ip_route_input_noref(skb, iph->daddr, iph->saddr, - iph->tos, skb->dev); - if (unlikely(err)) { - if (err == -EXDEV) - NET_INC_STATS_BH(dev_net(skb->dev), - LINUX_MIB_IPRPFILTER); - goto drop; - } + err = ip_route_input_noref(skb, iph->daddr, iph->saddr, + iph->tos, skb->dev); + if (unlikely(err)) + goto drop_error; }
#ifdef CONFIG_IP_ROUTE_CLASSID @@ -368,6 +367,11 @@ static int ip_rcv_finish(struct sk_buff drop: kfree_skb(skb); return NET_RX_DROP; + +drop_error: + if (err == -EXDEV) + NET_INC_STATS_BH(dev_net(skb->dev), LINUX_MIB_IPRPFILTER); + goto drop; }
/* --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -1616,23 +1616,23 @@ csum_err: } EXPORT_SYMBOL(tcp_v4_do_rcv);
-void tcp_v4_early_demux(struct sk_buff *skb) +int tcp_v4_early_demux(struct sk_buff *skb) { const struct iphdr *iph; const struct tcphdr *th; struct sock *sk;
if (skb->pkt_type != PACKET_HOST) - return; + return 0;
if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct tcphdr))) - return; + return 0;
iph = ip_hdr(skb); th = tcp_hdr(skb);
if (th->doff < sizeof(struct tcphdr) / 4) - return; + return 0;
sk = __inet_lookup_established(dev_net(skb->dev), &tcp_hashinfo, iph->saddr, th->source, @@ -1651,6 +1651,7 @@ void tcp_v4_early_demux(struct sk_buff * skb_dst_set_noref(skb, dst); } } + return 0; }
/* Packet is added to VJ-style prequeue for processing in process --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -1950,7 +1950,7 @@ static struct sock *__udp4_lib_demux_loo return result; }
-void udp_v4_early_demux(struct sk_buff *skb) +int udp_v4_early_demux(struct sk_buff *skb) { struct net *net = dev_net(skb->dev); const struct iphdr *iph; @@ -1962,7 +1962,7 @@ void udp_v4_early_demux(struct sk_buff *
/* validate the packet */ if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct udphdr))) - return; + return 0;
iph = ip_hdr(skb); uh = udp_hdr(skb); @@ -1972,14 +1972,14 @@ void udp_v4_early_demux(struct sk_buff * struct in_device *in_dev = __in_dev_get_rcu(skb->dev);
if (!in_dev) - return; + return 0;
/* we are supposed to accept bcast packets */ if (skb->pkt_type == PACKET_MULTICAST) { ours = ip_check_mc_rcu(in_dev, iph->daddr, iph->saddr, iph->protocol); if (!ours) - return; + return 0; }
sk = __udp4_lib_mcast_demux_lookup(net, uh->dest, iph->daddr, @@ -1988,11 +1988,11 @@ void udp_v4_early_demux(struct sk_buff * sk = __udp4_lib_demux_lookup(net, uh->dest, iph->daddr, uh->source, iph->saddr, dif); } else { - return; + return 0; }
if (!sk) - return; + return 0;
skb->sk = sk; skb->destructor = sock_edemux; @@ -2009,6 +2009,7 @@ void udp_v4_early_demux(struct sk_buff * skb_dst_set_noref(skb, dst); } } + return 0; }
int udp_rcv(struct sk_buff *skb)