net: tcp: use kfree_skb_reason() for tcp_v6_rcv()

Replace kfree_skb() used in tcp_v6_rcv() with kfree_skb_reason().

Reviewed-by: Mengen Sun <mengensun@tencent.com>
Reviewed-by: Hao Peng <flyingpeng@tencent.com>
Signed-off-by: Menglong Dong <imagedong@tencent.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 0c648bf..0aa1707 100644 (file)
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1627,6 +1627,7 @@ static void tcp_v6_fill_cb(struct sk_buff *skb, const struct ipv6hdr *hdr,
 
 INDIRECT_CALLABLE_SCOPE int tcp_v6_rcv(struct sk_buff *skb)
 {
+       enum skb_drop_reason drop_reason;
        int sdif = inet6_sdif(skb);
        int dif = inet6_iif(skb);
        const struct tcphdr *th;
@@ -1636,6 +1637,7 @@ INDIRECT_CALLABLE_SCOPE int tcp_v6_rcv(struct sk_buff *skb)
        int ret;
        struct net *net = dev_net(skb->dev);
 
+       drop_reason = SKB_DROP_REASON_NOT_SPECIFIED;
        if (skb->pkt_type != PACKET_HOST)
                goto discard_it;
 
@@ -1649,8 +1651,10 @@ INDIRECT_CALLABLE_SCOPE int tcp_v6_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;
 
@@ -1706,6 +1710,8 @@ process:
                        hdr = ipv6_hdr(skb);
                        tcp_v6_fill_cb(skb, hdr, th);
                        nsk = tcp_check_req(sk, skb, req, false, &req_stolen);
+               } else {
+                       drop_reason = SKB_DROP_REASON_SOCKET_FILTER;
                }
                if (!nsk) {
                        reqsk_put(req);
@@ -1741,14 +1747,18 @@ process:
                }
        }
 
-       if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
+       if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) {
+               drop_reason = SKB_DROP_REASON_XFRM_POLICY;
                goto discard_and_relse;
+       }
 
        if (tcp_v6_inbound_md5_hash(sk, skb, dif, sdif))
                goto discard_and_relse;
 
-       if (tcp_filter(sk, skb))
+       if (tcp_filter(sk, skb)) {
+               drop_reason = SKB_DROP_REASON_SOCKET_FILTER;
                goto discard_and_relse;
+       }
        th = (const struct tcphdr *)skb->data;
        hdr = ipv6_hdr(skb);
        tcp_v6_fill_cb(skb, hdr, th);
@@ -1779,6 +1789,7 @@ put_and_return:
        return ret ? -1 : 0;
 
 no_tcp_socket:
+       drop_reason = SKB_DROP_REASON_NO_SOCKET;
        if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
                goto discard_it;
 
@@ -1786,6 +1797,7 @@ no_tcp_socket:
 
        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:
@@ -1795,7 +1807,7 @@ bad_packet:
        }
 
 discard_it:
-       kfree_skb(skb);
+       kfree_skb_reason(skb, drop_reason);
        return 0;
 
 discard_and_relse:
@@ -1806,6 +1818,7 @@ discard_and_relse:
 
 do_time_wait:
        if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
+               drop_reason = SKB_DROP_REASON_XFRM_POLICY;
                inet_twsk_put(inet_twsk(sk));
                goto discard_it;
        }