[ 131/150] ipv4: fix error handling in icmp_protocol.

Greg Kroah-Hartman
2013-02-27T00:49:17Z

From: Li Wei <lw@cn.fujitsu.com>

[ Upstream commit 5b0520425e5ea81ba95ec486dd6bbb59a09fff0e ]

Now we handle icmp errors in each transport protocol's err_handler,
for icmp protocols, that is ping_err. Since this handler only care
of those icmp errors triggered by echo request, errors triggered
by echo reply(which sent by kernel) are sliently ignored.

So wrap ping_err() with icmp_err() to deal with those icmp errors.

Signed-off-by: Li Wei <lw@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
include/net/icmp.h | 1 +
net/ipv4/af_inet.c | 2 +-
net/ipv4/icmp.c | 23 +++++++++++++++++++++++
3 files changed, 25 insertions(+), 1 deletion(-)

--- a/include/net/icmp.h
+++ b/include/net/icmp.h
@@ -41,6 +41,7 @@ struct net;

extern void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info);
extern int icmp_rcv(struct sk_buff *skb);
+extern void icmp_err(struct sk_buff *, u32 info);
extern int icmp_init(void);
extern void icmp_out_count(struct net *net, unsigned char type);

--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -1595,7 +1595,7 @@ static const struct net_offload udp_offl

static const struct net_protocol icmp_protocol = {
.handler = icmp_rcv,
- .err_handler = ping_err,
+ .err_handler = icmp_err,
.no_policy = 1,
.netns_ok = 1,
};
--- a/net/ipv4/icmp.c
+++ b/net/ipv4/icmp.c
@@ -934,6 +934,29 @@ error:
goto drop;
}

+void icmp_err(struct sk_buff *skb, u32 info)
+{
+ struct iphdr *iph = (struct iphdr *)skb->data;
+ struct icmphdr *icmph = (struct icmphdr *)(skb->data+(iph->ihl<<2));
+ int type = icmp_hdr(skb)->type;
+ int code = icmp_hdr(skb)->code;
+ struct net *net = dev_net(skb->dev);
+
+ /*
+ * Use ping_err to handle all icmp errors except those
+ * triggered by ICMP_ECHOREPLY which sent from kernel.
+ */
+ if (icmph->type != ICMP_ECHOREPLY) {
+ ping_err(skb, info);
+ return;
+ }
+
+ if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED)
+ ipv4_update_pmtu(skb, net, info, 0, 0, IPPROTO_ICMP, 0);
+ else if (type == ICMP_REDIRECT)
+ ipv4_redirect(skb, net, 0, 0, IPPROTO_ICMP, 0);
+}
+
/*
* This table is the definition of how we handle ICMP.
*/