net: fix the counter ICMP_MIB_INERRORS/ICMP6_MIB_INERRORS

When dealing with ICMPv[46] Error Message, function icmp_socket_deliver()
and icmpv6_notify() do some valid checks on packet's length, but then some
protocols check packet's length redaudantly. So remove those duplicated
statements, and increase counter ICMP_MIB_INERRORS/ICMP6_MIB_INERRORS in
function icmp_socket_deliver() and icmpv6_notify() respectively.

In addition, add missed counter in udp6/udplite6 when socket is NULL.

Signed-off-by: Duan Jiong <duanj.fnst@cn.fujitsu.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

5 files changed, 17 insertions, 18 deletions

diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
index 42b7bcf8045b..092400ef88d0 100644
--- a/net/ipv4/icmp.c
+++ b/net/ipv4/icmp.c
@@ -663,8 +663,10 @@ static void icmp_socket_deliver(struct sk_buff *skb, u32 info)
         /* Checkin full IP header plus 8 bytes of protocol to
          * avoid additional coding at protocol handlers.
          */
-        if (!pskb_may_pull(skb, iph->ihl * 4 + 8))
+        if (!pskb_may_pull(skb, iph->ihl * 4 + 8)) {
+                ICMP_INC_STATS_BH(dev_net(skb->dev), ICMP_MIB_INERRORS);
                 return;
+        }
 
         raw_icmp_error(skb, protocol, info);
 
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 1edc739b9da5..d0ba39537d5c 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -344,11 +344,6 @@ void tcp_v4_err(struct sk_buff *icmp_skb, u32 info)
         int err;
         struct net *net = dev_net(icmp_skb->dev);
 
-        if (icmp_skb->len < (iph->ihl << 2) + 8) {
-                ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS);
-                return;
-        }
-
         sk = inet_lookup(net, &tcp_hashinfo, iph->daddr, th->dest,
                         iph->saddr, th->source, inet_iif(icmp_skb));
         if (!sk) {
diff --git a/net/ipv6/icmp.c b/net/ipv6/icmp.c
index f6c84a6eb238..06ba3e58320b 100644
--- a/net/ipv6/icmp.c
+++ b/net/ipv6/icmp.c
@@ -626,9 +626,10 @@ void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info)
         int inner_offset;
         __be16 frag_off;
         u8 nexthdr;
+        struct net *net = dev_net(skb->dev);
 
         if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
-                return;
+                goto out;
 
         nexthdr = ((struct ipv6hdr *)skb->data)->nexthdr;
         if (ipv6_ext_hdr(nexthdr)) {
@@ -636,14 +637,14 @@ void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info)
                 inner_offset = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr),
                                                 &nexthdr, &frag_off);
                 if (inner_offset<0)
-                        return;
+                        goto out;
         } else {
                 inner_offset = sizeof(struct ipv6hdr);
         }
 
         /* Checkin header including 8 bytes of inner protocol header. */
         if (!pskb_may_pull(skb, inner_offset+8))
-                return;
+                goto out;
 
         /* BUGGG_FUTURE: we should try to parse exthdrs in this packet.
            Without this we will not able f.e. to make source routed
@@ -652,13 +653,15 @@ void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info)
            --ANK (980726)
          */
 
-        rcu_read_lock();
         ipprot = rcu_dereference(inet6_protos[nexthdr]);
         if (ipprot && ipprot->err_handler)
                 ipprot->err_handler(skb, NULL, type, code, inner_offset, info);
-        rcu_read_unlock();
 
         raw6_icmp_error(skb, nexthdr, type, code, inner_offset, info);
+        return;
+
+out:
+        ICMP6_INC_STATS_BH(net, __in6_dev_get(skb->dev), ICMP6_MIB_INERRORS);
 }
 
 /*
diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index 5b6091de5868..c6941a1ac977 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -533,11 +533,15 @@ void __udp6_lib_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
         struct udphdr *uh = (struct udphdr*)(skb->data+offset);
         struct sock *sk;
         int err;
+        struct net *net = dev_net(skb->dev);
 
-        sk = __udp6_lib_lookup(dev_net(skb->dev), daddr, uh->dest,
+        sk = __udp6_lib_lookup(net, daddr, uh->dest,
                                saddr, uh->source, inet6_iif(skb), udptable);
-        if (sk == NULL)
+        if (sk == NULL) {
+                ICMP6_INC_STATS_BH(net, __in6_dev_get(skb->dev),
+                                   ICMP6_MIB_INERRORS);
                 return;
+        }
 
         if (type == ICMPV6_PKT_TOOBIG) {
                 if (!ip6_sk_accept_pmtu(sk))
diff --git a/net/sctp/input.c b/net/sctp/input.c
index f2e2cbd2d750..c1b991294516 100644
--- a/net/sctp/input.c
+++ b/net/sctp/input.c
@@ -575,11 +575,6 @@ void sctp_v4_err(struct sk_buff *skb, __u32 info)
         int err;
         struct net *net = dev_net(skb->dev);
 
-        if (skb->len < ihlen + 8) {
-                ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS);
-                return;
-        }
-
         /* Fix up skb to look at the embedded net header. */
         saveip = skb->network_header;
         savesctp = skb->transport_header;