@@ -469,6 +469,10 @@ enum skb_drop_reason {
SKB_DROP_REASON_PKT_TOO_BIG, /* packet size is too big (maybe exceed
* the MTU)
*/
+ SKB_DROP_REASON_LISTENOVERFLOWS, /* accept queue of the listen socket is full */
+ SKB_DROP_REASON_TCP_REQQFULLDROP, /* request queue of the listen
+ * socket is full
+ */
SKB_DROP_REASON_MAX,
};
@@ -80,6 +80,8 @@
EM(SKB_DROP_REASON_IP_INADDRERRORS, IP_INADDRERRORS) \
EM(SKB_DROP_REASON_IP_INNOROUTES, IP_INNOROUTES) \
EM(SKB_DROP_REASON_PKT_TOO_BIG, PKT_TOO_BIG) \
+ EM(SKB_DROP_REASON_LISTENOVERFLOWS, LISTENOVERFLOWS) \
+ EM(SKB_DROP_REASON_TCP_REQQFULLDROP, TCP_REQQFULLDROP) \
EMe(SKB_DROP_REASON_MAX, MAX)
#undef EM
@@ -6411,7 +6411,7 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb)
struct inet_connection_sock *icsk = inet_csk(sk);
const struct tcphdr *th = tcp_hdr(skb);
struct request_sock *req;
- int queued = 0;
+ int err, queued = 0;
bool acceptable;
SKB_DR(reason);
@@ -6438,13 +6438,16 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb)
*/
rcu_read_lock();
local_bh_disable();
- acceptable = icsk->icsk_af_ops->conn_request(sk, skb) >= 0;
+ err = icsk->icsk_af_ops->conn_request(sk, skb);
local_bh_enable();
rcu_read_unlock();
- if (!acceptable)
+ if (err < 0)
return 1;
- consume_skb(skb);
+ if (err)
+ kfree_skb_reason(skb, err);
+ else
+ consume_skb(skb);
return 0;
}
SKB_DR_SET(reason, TCP_FLAGS);
@@ -6878,6 +6881,7 @@ int tcp_conn_request(struct request_sock_ops *rsk_ops,
bool want_cookie = false;
struct dst_entry *dst;
struct flowi fl;
+ SKB_DR(reason);
/* TW buckets are converted to open requests without
* limitations, they conserve resources and peer is
@@ -6886,12 +6890,15 @@ int tcp_conn_request(struct request_sock_ops *rsk_ops,
if ((net->ipv4.sysctl_tcp_syncookies == 2 ||
inet_csk_reqsk_queue_is_full(sk)) && !isn) {
want_cookie = tcp_syn_flood_action(sk, rsk_ops->slab_name);
- if (!want_cookie)
+ if (!want_cookie) {
+ SKB_DR_SET(reason, TCP_REQQFULLDROP);
goto drop;
+ }
}
if (sk_acceptq_is_full(sk)) {
NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
+ SKB_DR_SET(reason, LISTENOVERFLOWS);
goto drop;
}
@@ -6947,6 +6954,7 @@ int tcp_conn_request(struct request_sock_ops *rsk_ops,
*/
pr_drop_req(req, ntohs(tcp_hdr(skb)->source),
rsk_ops->family);
+ SKB_DR_SET(reason, TCP_REQQFULLDROP);
goto drop_and_release;
}
@@ -7007,6 +7015,6 @@ int tcp_conn_request(struct request_sock_ops *rsk_ops,
__reqsk_free(req);
drop:
tcp_listendrop(sk);
- return 0;
+ return reason;
}
EXPORT_SYMBOL(tcp_conn_request);
@@ -1470,7 +1470,7 @@ int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
drop:
tcp_listendrop(sk);
- return 0;
+ return SKB_DROP_REASON_IP_INADDRERRORS;
}
EXPORT_SYMBOL(tcp_v4_conn_request);
@@ -1158,7 +1158,7 @@ static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
if (ipv6_addr_v4mapped(&ipv6_hdr(skb)->saddr)) {
__IP6_INC_STATS(sock_net(sk), NULL, IPSTATS_MIB_INHDRERRORS);
- return 0;
+ return SKB_DROP_REASON_IP_INADDRERRORS;
}
return tcp_conn_request(&tcp6_request_sock_ops,
@@ -1166,7 +1166,7 @@ static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
drop:
tcp_listendrop(sk);
- return 0; /* don't send reset */
+ return SKB_DROP_REASON_IP_INADDRERRORS; /* don't send reset */
}
static void tcp_v6_restore_cb(struct sk_buff *skb)