diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index ef0870abc791..c9c97b0d0fe9 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -313,6 +313,10 @@ struct sk_buff; */ enum skb_drop_reason { SKB_DROP_REASON_NOT_SPECIFIED, + SKB_DROP_REASON_NO_SOCKET, + SKB_DROP_REASON_PKT_TOO_SMALL, + SKB_DROP_REASON_TCP_CSUM, + SKB_DROP_REASON_TCP_FILTER, SKB_DROP_REASON_MAX, }; diff --git a/include/trace/events/skb.h b/include/trace/events/skb.h index 294c61bbe44b..faa7d068a7bc 100644 --- a/include/trace/events/skb.h +++ b/include/trace/events/skb.h @@ -11,6 +11,10 @@ #define TRACE_SKB_DROP_REASON \ EM(SKB_DROP_REASON_NOT_SPECIFIED, NOT_SPECIFIED) \ + EM(SKB_DROP_REASON_NO_SOCKET, NO_SOCKET) \ + EM(SKB_DROP_REASON_PKT_TOO_SMALL, PKT_TOO_SMALL) \ + EM(SKB_DROP_REASON_TCP_CSUM, TCP_CSUM) \ + EM(SKB_DROP_REASON_TCP_FILTER, TCP_FILTER) \ EMe(SKB_DROP_REASON_MAX, MAX) #undef EM diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 9861786b8336..b3f34e366b27 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -1971,8 +1971,10 @@ int tcp_v4_rcv(struct sk_buff *skb) const struct tcphdr *th; bool refcounted; struct sock *sk; + int drop_reason; int ret; + drop_reason = SKB_DROP_REASON_NOT_SPECIFIED; if (skb->pkt_type != PACKET_HOST) goto discard_it; @@ -1984,8 +1986,10 @@ int tcp_v4_rcv(struct sk_buff *skb) th = (const struct tcphdr *)skb->data; - if (unlikely(th->doff < sizeof(struct tcphdr) / 4)) + if (unlikely(th->doff < sizeof(struct tcphdr) / 4)) { + drop_reason = SKB_DROP_REASON_PKT_TOO_SMALL; goto bad_packet; + } if (!pskb_may_pull(skb, th->doff * 4)) goto discard_it; @@ -2090,8 +2094,10 @@ int tcp_v4_rcv(struct sk_buff *skb) nf_reset_ct(skb); - if (tcp_filter(sk, skb)) + if (tcp_filter(sk, skb)) { + drop_reason = SKB_DROP_REASON_TCP_FILTER; goto discard_and_relse; + } th = (const struct tcphdr *)skb->data; iph = ip_hdr(skb); tcp_v4_fill_cb(skb, iph, th); @@ -2124,6 +2130,7 @@ int tcp_v4_rcv(struct sk_buff *skb) return ret; no_tcp_socket: + drop_reason = SKB_DROP_REASON_NO_SOCKET; if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) goto discard_it; @@ -2131,6 +2138,7 @@ int tcp_v4_rcv(struct sk_buff *skb) if (tcp_checksum_complete(skb)) { csum_error: + drop_reason = SKB_DROP_REASON_TCP_CSUM; trace_tcp_bad_csum(skb); __TCP_INC_STATS(net, TCP_MIB_CSUMERRORS); bad_packet: @@ -2141,7 +2149,7 @@ int tcp_v4_rcv(struct sk_buff *skb) discard_it: /* Discard frame. */ - kfree_skb(skb); + kfree_skb_reason(skb, drop_reason); return 0; discard_and_relse: