From: Paolo Abeni <pabeni@redhat.com>
Date: Thu, 28 Sep 2017 15:51:36 +0200
Subject: IPv4: early demux can return an error code
Patch-mainline: v4.14-rc4
Git-commit: 7487449c86c65202b3b725c4524cb48dd65e4e6f
References: bsc#1076830
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>
Acked-by: Michal Kubecek <mkubecek@suse.cz>
---
include/net/protocol.h | 4 ++--
include/net/tcp.h | 2 +-
include/net/udp.h | 2 +-
net/ipv4/ip_input.c | 25 +++++++++++++++----------
net/ipv4/tcp_ipv4.c | 9 +++++----
net/ipv4/udp.c | 11 ++++++-----
6 files changed, 30 insertions(+), 23 deletions(-)
diff --git a/include/net/protocol.h b/include/net/protocol.h
index 65ba335b0e7e..4fc75f7ae23b 100644
--- a/include/net/protocol.h
+++ b/include/net/protocol.h
@@ -39,8 +39,8 @@
/* This is used to register protocols. */
struct net_protocol {
- void (*early_demux)(struct sk_buff *skb);
- void (*early_demux_handler)(struct sk_buff *skb);
+ int (*early_demux)(struct sk_buff *skb);
+ int (*early_demux_handler)(struct sk_buff *skb);
int (*handler)(struct sk_buff *skb);
void (*err_handler)(struct sk_buff *skb, u32 info);
unsigned int no_policy:1,
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 82e9251323cc..9c0515f33ae9 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -345,7 +345,7 @@ 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);
diff --git a/include/net/udp.h b/include/net/udp.h
index f7eb9ecee482..7e12b8588f4c 100644
--- a/include/net/udp.h
+++ b/include/net/udp.h
@@ -259,7 +259,7 @@ static inline struct sk_buff *skb_recv_udp(struct sock *sk, unsigned int flags,
return __skb_recv_udp(sk, flags, noblock, &peeked, &off, err);
}
-void udp_v4_early_demux(struct sk_buff *skb);
+int udp_v4_early_demux(struct sk_buff *skb);
bool udp_sk_rx_dst_set(struct sock *sk, struct dst_entry *dst);
int udp_get_port(struct sock *sk, unsigned short snum,
int (*saddr_cmp)(const struct sock *,
diff --git a/net/ipv4/ip_input.c b/net/ipv4/ip_input.c
index fa2dc8f692c6..57fc13c6ab2b 100644
--- a/net/ipv4/ip_input.c
+++ b/net/ipv4/ip_input.c
@@ -311,9 +311,10 @@ static inline bool ip_rcv_options(struct sk_buff *skb)
static int ip_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
{
const struct iphdr *iph = ip_hdr(skb);
- struct rtable *rt;
+ int (*edemux)(struct sk_buff *skb);
struct net_device *dev = skb->dev;
- void (*edemux)(struct sk_buff *skb);
+ struct rtable *rt;
+ int err;
/* if ingress device is enslaved to an L3 master device pass the
* skb to its handler for processing
@@ -331,7 +332,9 @@ static int ip_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
ipprot = rcu_dereference(inet_protos[protocol]);
if (ipprot && (edemux = READ_ONCE(ipprot->early_demux))) {
- edemux(skb);
+ err = edemux(skb);
+ if (unlikely(err))
+ goto drop_error;
/* must reload iph, skb->head might have changed */
iph = ip_hdr(skb);
}
@@ -342,13 +345,10 @@ static int ip_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
* how the packet travels inside Linux networking.
*/
if (!skb_valid_dst(skb)) {
- int err = ip_route_input_noref(skb, iph->daddr, iph->saddr,
- iph->tos, dev);
- if (unlikely(err)) {
- if (err == -EXDEV)
- __NET_INC_STATS(net, LINUX_MIB_IPRPFILTER);
- goto drop;
- }
+ err = ip_route_input_noref(skb, iph->daddr, iph->saddr,
+ iph->tos, dev);
+ if (unlikely(err))
+ goto drop_error;
}
#ifdef CONFIG_IP_ROUTE_CLASSID
@@ -399,6 +399,11 @@ static int ip_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
drop:
kfree_skb(skb);
return NET_RX_DROP;
+
+drop_error:
+ if (err == -EXDEV)
+ __NET_INC_STATS(net, LINUX_MIB_IPRPFILTER);
+ goto drop;
}
/*
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index c9845859fe94..51e440c54944 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1448,23 +1448,23 @@ int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb)
}
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,
@@ -1483,6 +1483,7 @@ void tcp_v4_early_demux(struct sk_buff *skb)
skb_dst_set_noref(skb, dst);
}
}
+ return 0;
}
bool tcp_add_backlog(struct sock *sk, struct sk_buff *skb)
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 018ef826f37b..25c108218b54 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -2158,7 +2158,7 @@ static struct sock *__udp4_lib_demux_lookup(struct net *net,
return NULL;
}
-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;
@@ -2170,7 +2170,7 @@ void udp_v4_early_demux(struct sk_buff *skb)
/* 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);
@@ -2180,14 +2180,14 @@ void udp_v4_early_demux(struct sk_buff *skb)
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,
@@ -2198,7 +2198,7 @@ void udp_v4_early_demux(struct sk_buff *skb)
}
if (!sk || !atomic_inc_not_zero_hint(&sk->sk_refcnt, 2))
- return;
+ return 0;
skb->sk = sk;
skb->destructor = sock_efree;
@@ -2213,6 +2213,7 @@ void udp_v4_early_demux(struct sk_buff *skb)
*/
skb_dst_set_noref(skb, dst);
}
+ return 0;
}
int udp_rcv(struct sk_buff *skb)
--
2.16.0