net: Add MIB counters for checksum errors
Add MIB counters for checksum errors in IP layer,
and TCP/UDP/ICMP layers, to help diagnose problems.
$ nstat -a | grep Csum
IcmpInCsumErrors 72 0.0
TcpInCsumErrors 382 0.0
UdpInCsumErrors 463221 0.0
Icmp6InCsumErrors 75 0.0
Udp6InCsumErrors 173442 0.0
IpExtInCsumErrors 10884 0.0
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 2278669..8ea9751 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1866,6 +1866,7 @@
return 0;
csum_err:
+ TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_CSUMERRORS);
TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_INERRS);
goto discard;
}
@@ -1985,7 +1986,7 @@
* provided case of th->doff==0 is eliminated.
* So, we defer the checks. */
if (!skb_csum_unnecessary(skb) && tcp_v4_checksum_init(skb))
- goto bad_packet;
+ goto csum_error;
th = tcp_hdr(skb);
iph = ip_hdr(skb);
@@ -2051,6 +2052,8 @@
goto discard_it;
if (skb->len < (th->doff << 2) || tcp_checksum_complete(skb)) {
+csum_error:
+ TCP_INC_STATS_BH(net, TCP_MIB_CSUMERRORS);
bad_packet:
TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
} else {
@@ -2072,10 +2075,13 @@
goto discard_it;
}
- if (skb->len < (th->doff << 2) || tcp_checksum_complete(skb)) {
- TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
+ if (skb->len < (th->doff << 2)) {
inet_twsk_put(inet_twsk(sk));
- goto discard_it;
+ goto bad_packet;
+ }
+ if (tcp_checksum_complete(skb)) {
+ inet_twsk_put(inet_twsk(sk));
+ goto csum_error;
}
switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) {
case TCP_TW_SYN: {
