ipv6: Add reasons for skb drops to __udp6_lib_rcv

Add reasons to __udp6_lib_rcv for skb drops. The only twist is that the
NO_SOCKET takes precedence over the CSUM or other counters for that
path (motivation behind this patch - csum counter was misleading).

Signed-off-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index c687259..7f0fa9b 100644 (file)
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -912,6 +912,7 @@ static int udp6_unicast_rcv_skb(struct sock *sk, struct sk_buff *skb,
 int __udp6_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
                   int proto)
 {
+       enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED;
        const struct in6_addr *saddr, *daddr;
        struct net *net = dev_net(skb->dev);
        struct udphdr *uh;
@@ -988,6 +989,8 @@ int __udp6_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
                return udp6_unicast_rcv_skb(sk, skb, uh);
        }
 
+       reason = SKB_DROP_REASON_NO_SOCKET;
+
        if (!uh->check)
                goto report_csum_error;
 
@@ -1000,10 +1003,12 @@ int __udp6_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
        __UDP6_INC_STATS(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
        icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
 
-       kfree_skb(skb);
+       kfree_skb_reason(skb, reason);
        return 0;
 
 short_packet:
+       if (reason == SKB_DROP_REASON_NOT_SPECIFIED)
+               reason = SKB_DROP_REASON_PKT_TOO_SMALL;
        net_dbg_ratelimited("UDP%sv6: short packet: From [%pI6c]:%u %d/%d to [%pI6c]:%u\n",
                            proto == IPPROTO_UDPLITE ? "-Lite" : "",
                            saddr, ntohs(uh->source),
@@ -1014,10 +1019,12 @@ short_packet:
 report_csum_error:
        udp6_csum_zero_error(skb);
 csum_error:
+       if (reason == SKB_DROP_REASON_NOT_SPECIFIED)
+               reason = SKB_DROP_REASON_UDP_CSUM;
        __UDP6_INC_STATS(net, UDP_MIB_CSUMERRORS, proto == IPPROTO_UDPLITE);
 discard:
        __UDP6_INC_STATS(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
-       kfree_skb(skb);
+       kfree_skb_reason(skb, reason);
        return 0;
 }