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Diffstat (limited to 'net/ipv4')
-rw-r--r--net/ipv4/tcp_input.c42
-rw-r--r--net/ipv4/tcp_ipv4.c32
2 files changed, 56 insertions, 18 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 92e65d56dc2c..2088f93fa37b 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -4684,10 +4684,16 @@ static bool tcp_ooo_try_coalesce(struct sock *sk,
return res;
}
-static void tcp_drop(struct sock *sk, struct sk_buff *skb)
+static void tcp_drop_reason(struct sock *sk, struct sk_buff *skb,
+ enum skb_drop_reason reason)
{
sk_drops_add(sk, skb);
- __kfree_skb(skb);
+ kfree_skb_reason(skb, reason);
+}
+
+static void tcp_drop(struct sock *sk, struct sk_buff *skb)
+{
+ tcp_drop_reason(sk, skb, SKB_DROP_REASON_NOT_SPECIFIED);
}
/* This one checks to see if we can put data from the
@@ -4773,7 +4779,7 @@ static void tcp_data_queue_ofo(struct sock *sk, struct sk_buff *skb)
if (unlikely(tcp_try_rmem_schedule(sk, skb, skb->truesize))) {
NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPOFODROP);
sk->sk_data_ready(sk);
- tcp_drop(sk, skb);
+ tcp_drop_reason(sk, skb, SKB_DROP_REASON_PROTO_MEM);
return;
}
@@ -4836,7 +4842,8 @@ coalesce_done:
/* All the bits are present. Drop. */
NET_INC_STATS(sock_net(sk),
LINUX_MIB_TCPOFOMERGE);
- tcp_drop(sk, skb);
+ tcp_drop_reason(sk, skb,
+ SKB_DROP_REASON_TCP_OFOMERGE);
skb = NULL;
tcp_dsack_set(sk, seq, end_seq);
goto add_sack;
@@ -4855,7 +4862,8 @@ coalesce_done:
TCP_SKB_CB(skb1)->end_seq);
NET_INC_STATS(sock_net(sk),
LINUX_MIB_TCPOFOMERGE);
- tcp_drop(sk, skb1);
+ tcp_drop_reason(sk, skb1,
+ SKB_DROP_REASON_TCP_OFOMERGE);
goto merge_right;
}
} else if (tcp_ooo_try_coalesce(sk, skb1,
@@ -4883,7 +4891,7 @@ merge_right:
tcp_dsack_extend(sk, TCP_SKB_CB(skb1)->seq,
TCP_SKB_CB(skb1)->end_seq);
NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPOFOMERGE);
- tcp_drop(sk, skb1);
+ tcp_drop_reason(sk, skb1, SKB_DROP_REASON_TCP_OFOMERGE);
}
/* If there is no skb after us, we are the last_skb ! */
if (!skb1)
@@ -4982,6 +4990,7 @@ void tcp_data_ready(struct sock *sk)
static void tcp_data_queue(struct sock *sk, struct sk_buff *skb)
{
struct tcp_sock *tp = tcp_sk(sk);
+ enum skb_drop_reason reason;
bool fragstolen;
int eaten;
@@ -5000,6 +5009,7 @@ static void tcp_data_queue(struct sock *sk, struct sk_buff *skb)
skb_dst_drop(skb);
__skb_pull(skb, tcp_hdr(skb)->doff * 4);
+ reason = SKB_DROP_REASON_NOT_SPECIFIED;
tp->rx_opt.dsack = 0;
/* Queue data for delivery to the user.
@@ -5008,6 +5018,7 @@ static void tcp_data_queue(struct sock *sk, struct sk_buff *skb)
*/
if (TCP_SKB_CB(skb)->seq == tp->rcv_nxt) {
if (tcp_receive_window(tp) == 0) {
+ reason = SKB_DROP_REASON_TCP_ZEROWINDOW;
NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPZEROWINDOWDROP);
goto out_of_window;
}
@@ -5017,6 +5028,7 @@ queue_and_out:
if (skb_queue_len(&sk->sk_receive_queue) == 0)
sk_forced_mem_schedule(sk, skb->truesize);
else if (tcp_try_rmem_schedule(sk, skb, skb->truesize)) {
+ reason = SKB_DROP_REASON_PROTO_MEM;
NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPRCVQDROP);
sk->sk_data_ready(sk);
goto drop;
@@ -5053,6 +5065,7 @@ queue_and_out:
if (!after(TCP_SKB_CB(skb)->end_seq, tp->rcv_nxt)) {
tcp_rcv_spurious_retrans(sk, skb);
/* A retransmit, 2nd most common case. Force an immediate ack. */
+ reason = SKB_DROP_REASON_TCP_OLD_DATA;
NET_INC_STATS(sock_net(sk), LINUX_MIB_DELAYEDACKLOST);
tcp_dsack_set(sk, TCP_SKB_CB(skb)->seq, TCP_SKB_CB(skb)->end_seq);
@@ -5060,13 +5073,16 @@ out_of_window:
tcp_enter_quickack_mode(sk, TCP_MAX_QUICKACKS);
inet_csk_schedule_ack(sk);
drop:
- tcp_drop(sk, skb);
+ tcp_drop_reason(sk, skb, reason);
return;
}
/* Out of window. F.e. zero window probe. */
- if (!before(TCP_SKB_CB(skb)->seq, tp->rcv_nxt + tcp_receive_window(tp)))
+ if (!before(TCP_SKB_CB(skb)->seq,
+ tp->rcv_nxt + tcp_receive_window(tp))) {
+ reason = SKB_DROP_REASON_TCP_OVERWINDOW;
goto out_of_window;
+ }
if (before(TCP_SKB_CB(skb)->seq, tp->rcv_nxt)) {
/* Partial packet, seq < rcv_next < end_seq */
@@ -5076,6 +5092,7 @@ drop:
* remembering D-SACK for its head made in previous line.
*/
if (!tcp_receive_window(tp)) {
+ reason = SKB_DROP_REASON_TCP_ZEROWINDOW;
NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPZEROWINDOWDROP);
goto out_of_window;
}
@@ -5781,6 +5798,7 @@ discard:
*/
void tcp_rcv_established(struct sock *sk, struct sk_buff *skb)
{
+ enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED;
const struct tcphdr *th = (const struct tcphdr *)skb->data;
struct tcp_sock *tp = tcp_sk(sk);
unsigned int len = skb->len;
@@ -5869,6 +5887,7 @@ void tcp_rcv_established(struct sock *sk, struct sk_buff *skb)
tp->rcv_rtt_last_tsecr = tp->rx_opt.rcv_tsecr;
return;
} else { /* Header too small */
+ reason = SKB_DROP_REASON_PKT_TOO_SMALL;
TCP_INC_STATS(sock_net(sk), TCP_MIB_INERRS);
goto discard;
}
@@ -5924,8 +5943,10 @@ slow_path:
if (len < (th->doff << 2) || tcp_checksum_complete(skb))
goto csum_error;
- if (!th->ack && !th->rst && !th->syn)
+ if (!th->ack && !th->rst && !th->syn) {
+ reason = SKB_DROP_REASON_TCP_FLAGS;
goto discard;
+ }
/*
* Standard slow path.
@@ -5951,12 +5972,13 @@ step5:
return;
csum_error:
+ reason = SKB_DROP_REASON_TCP_CSUM;
trace_tcp_bad_csum(skb);
TCP_INC_STATS(sock_net(sk), TCP_MIB_CSUMERRORS);
TCP_INC_STATS(sock_net(sk), TCP_MIB_INERRS);
discard:
- tcp_drop(sk, skb);
+ tcp_drop_reason(sk, skb, reason);
}
EXPORT_SYMBOL(tcp_rcv_established);
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 6873f46fc8ba..d42824aedc36 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1412,7 +1412,8 @@ EXPORT_SYMBOL(tcp_v4_md5_hash_skb);
/* Called with rcu_read_lock() */
static bool tcp_v4_inbound_md5_hash(const struct sock *sk,
const struct sk_buff *skb,
- int dif, int sdif)
+ int dif, int sdif,
+ enum skb_drop_reason *reason)
{
#ifdef CONFIG_TCP_MD5SIG
/*
@@ -1445,11 +1446,13 @@ static bool tcp_v4_inbound_md5_hash(const struct sock *sk,
return false;
if (hash_expected && !hash_location) {
+ *reason = SKB_DROP_REASON_TCP_MD5NOTFOUND;
NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND);
return true;
}
if (!hash_expected && hash_location) {
+ *reason = SKB_DROP_REASON_TCP_MD5UNEXPECTED;
NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED);
return true;
}
@@ -1462,6 +1465,7 @@ static bool tcp_v4_inbound_md5_hash(const struct sock *sk,
NULL, skb);
if (genhash || memcmp(hash_location, newhash, 16) != 0) {
+ *reason = SKB_DROP_REASON_TCP_MD5FAILURE;
NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5FAILURE);
net_info_ratelimited("MD5 Hash failed for (%pI4, %d)->(%pI4, %d)%s L3 index %d\n",
&iph->saddr, ntohs(th->source),
@@ -1704,6 +1708,7 @@ INDIRECT_CALLABLE_DECLARE(struct dst_entry *ipv4_dst_check(struct dst_entry *,
*/
int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb)
{
+ enum skb_drop_reason reason;
struct sock *rsk;
if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
@@ -1726,6 +1731,7 @@ int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb)
return 0;
}
+ reason = SKB_DROP_REASON_NOT_SPECIFIED;
if (tcp_checksum_complete(skb))
goto csum_err;
@@ -1753,7 +1759,7 @@ int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb)
reset:
tcp_v4_send_reset(rsk, skb);
discard:
- kfree_skb(skb);
+ kfree_skb_reason(skb, reason);
/* Be careful here. If this function gets more complicated and
* gcc suffers from register pressure on the x86, sk (in %ebx)
* might be destroyed here. This current version compiles correctly,
@@ -1762,6 +1768,7 @@ discard:
return 0;
csum_err:
+ reason = SKB_DROP_REASON_TCP_CSUM;
trace_tcp_bad_csum(skb);
TCP_INC_STATS(sock_net(sk), TCP_MIB_CSUMERRORS);
TCP_INC_STATS(sock_net(sk), TCP_MIB_INERRS);
@@ -1807,7 +1814,8 @@ int tcp_v4_early_demux(struct sk_buff *skb)
return 0;
}
-bool tcp_add_backlog(struct sock *sk, struct sk_buff *skb)
+bool tcp_add_backlog(struct sock *sk, struct sk_buff *skb,
+ enum skb_drop_reason *reason)
{
u32 limit, tail_gso_size, tail_gso_segs;
struct skb_shared_info *shinfo;
@@ -1833,6 +1841,7 @@ bool tcp_add_backlog(struct sock *sk, struct sk_buff *skb)
if (unlikely(tcp_checksum_complete(skb))) {
bh_unlock_sock(sk);
trace_tcp_bad_csum(skb);
+ *reason = SKB_DROP_REASON_TCP_CSUM;
__TCP_INC_STATS(sock_net(sk), TCP_MIB_CSUMERRORS);
__TCP_INC_STATS(sock_net(sk), TCP_MIB_INERRS);
return true;
@@ -1921,6 +1930,7 @@ no_coalesce:
if (unlikely(sk_add_backlog(sk, skb, limit))) {
bh_unlock_sock(sk);
+ *reason = SKB_DROP_REASON_SOCKET_BACKLOG;
__NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPBACKLOGDROP);
return true;
}
@@ -1971,13 +1981,13 @@ static void tcp_v4_fill_cb(struct sk_buff *skb, const struct iphdr *iph,
int tcp_v4_rcv(struct sk_buff *skb)
{
struct net *net = dev_net(skb->dev);
+ enum skb_drop_reason drop_reason;
int sdif = inet_sdif(skb);
int dif = inet_iif(skb);
const struct iphdr *iph;
const struct tcphdr *th;
bool refcounted;
struct sock *sk;
- int drop_reason;
int ret;
drop_reason = SKB_DROP_REASON_NOT_SPECIFIED;
@@ -2025,7 +2035,8 @@ process:
struct sock *nsk;
sk = req->rsk_listener;
- if (unlikely(tcp_v4_inbound_md5_hash(sk, skb, dif, sdif))) {
+ if (unlikely(tcp_v4_inbound_md5_hash(sk, skb, dif, sdif,
+ &drop_reason))) {
sk_drops_add(sk, skb);
reqsk_put(req);
goto discard_it;
@@ -2057,6 +2068,8 @@ process:
iph = ip_hdr(skb);
tcp_v4_fill_cb(skb, iph, th);
nsk = tcp_check_req(sk, skb, req, false, &req_stolen);
+ } else {
+ drop_reason = SKB_DROP_REASON_SOCKET_FILTER;
}
if (!nsk) {
reqsk_put(req);
@@ -2092,10 +2105,12 @@ process:
}
}
- if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
+ if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb)) {
+ drop_reason = SKB_DROP_REASON_XFRM_POLICY;
goto discard_and_relse;
+ }
- if (tcp_v4_inbound_md5_hash(sk, skb, dif, sdif))
+ if (tcp_v4_inbound_md5_hash(sk, skb, dif, sdif, &drop_reason))
goto discard_and_relse;
nf_reset_ct(skb);
@@ -2124,7 +2139,7 @@ process:
if (!sock_owned_by_user(sk)) {
ret = tcp_v4_do_rcv(sk, skb);
} else {
- if (tcp_add_backlog(sk, skb))
+ if (tcp_add_backlog(sk, skb, &drop_reason))
goto discard_and_relse;
}
bh_unlock_sock(sk);
@@ -2166,6 +2181,7 @@ discard_and_relse:
do_time_wait:
if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) {
+ drop_reason = SKB_DROP_REASON_XFRM_POLICY;
inet_twsk_put(inet_twsk(sk));
goto discard_it;
}
generated by cgit (git 2.34.1) at 2025-09-06 06:35:23 +0000