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-rw-r--r--Documentation/networking/net_cachelines/snmp.rst1
-rw-r--r--include/net/dropreason-core.h9
-rw-r--r--include/net/sock.h2
-rw-r--r--include/uapi/linux/snmp.h1
-rw-r--r--net/ipv4/proc.c1
-rw-r--r--net/ipv4/tcp_input.c48
-rw-r--r--tools/testing/selftests/net/packetdrill/tcp_ooo_rcv_mss.pkt27
-rw-r--r--tools/testing/selftests/net/packetdrill/tcp_rcv_big_endseq.pkt44
-rw-r--r--tools/testing/selftests/net/packetdrill/tcp_rcv_toobig.pkt33
9 files changed, 152 insertions, 14 deletions
diff --git a/Documentation/networking/net_cachelines/snmp.rst b/Documentation/networking/net_cachelines/snmp.rst
index bd44b3eebbef..bce4eb35ec48 100644
--- a/Documentation/networking/net_cachelines/snmp.rst
+++ b/Documentation/networking/net_cachelines/snmp.rst
@@ -36,6 +36,7 @@ unsigned_long LINUX_MIB_TIMEWAITRECYCLED
unsigned_long LINUX_MIB_TIMEWAITKILLED
unsigned_long LINUX_MIB_PAWSACTIVEREJECTED
unsigned_long LINUX_MIB_PAWSESTABREJECTED
+unsigned_long LINUX_MIB_BEYOND_WINDOW
unsigned_long LINUX_MIB_TSECR_REJECTED
unsigned_long LINUX_MIB_PAWS_OLD_ACK
unsigned_long LINUX_MIB_PAWS_TW_REJECTED
diff --git a/include/net/dropreason-core.h b/include/net/dropreason-core.h
index b9e78290269e..229bb1826f2a 100644
--- a/include/net/dropreason-core.h
+++ b/include/net/dropreason-core.h
@@ -45,6 +45,7 @@
FN(TCP_LISTEN_OVERFLOW) \
FN(TCP_OLD_SEQUENCE) \
FN(TCP_INVALID_SEQUENCE) \
+ FN(TCP_INVALID_END_SEQUENCE) \
FN(TCP_INVALID_ACK_SEQUENCE) \
FN(TCP_RESET) \
FN(TCP_INVALID_SYN) \
@@ -303,9 +304,15 @@ enum skb_drop_reason {
SKB_DROP_REASON_TCP_LISTEN_OVERFLOW,
/** @SKB_DROP_REASON_TCP_OLD_SEQUENCE: Old SEQ field (duplicate packet) */
SKB_DROP_REASON_TCP_OLD_SEQUENCE,
- /** @SKB_DROP_REASON_TCP_INVALID_SEQUENCE: Not acceptable SEQ field */
+ /** @SKB_DROP_REASON_TCP_INVALID_SEQUENCE: Not acceptable SEQ field. */
SKB_DROP_REASON_TCP_INVALID_SEQUENCE,
/**
+ * @SKB_DROP_REASON_TCP_INVALID_END_SEQUENCE:
+ * Not acceptable END_SEQ field.
+ * Corresponds to LINUX_MIB_BEYOND_WINDOW.
+ */
+ SKB_DROP_REASON_TCP_INVALID_END_SEQUENCE,
+ /**
* @SKB_DROP_REASON_TCP_INVALID_ACK_SEQUENCE: Not acceptable ACK SEQ
* field because ack sequence is not in the window between snd_una
* and snd_nxt
diff --git a/include/net/sock.h b/include/net/sock.h
index 0f2443d4ec58..c8a4b283df6f 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -1553,7 +1553,7 @@ __sk_rmem_schedule(struct sock *sk, int size, bool pfmemalloc)
}
static inline bool
-sk_rmem_schedule(struct sock *sk, struct sk_buff *skb, int size)
+sk_rmem_schedule(struct sock *sk, const struct sk_buff *skb, int size)
{
return __sk_rmem_schedule(sk, size, skb_pfmemalloc(skb));
}
diff --git a/include/uapi/linux/snmp.h b/include/uapi/linux/snmp.h
index 1d234d7e1892..49f5640092a0 100644
--- a/include/uapi/linux/snmp.h
+++ b/include/uapi/linux/snmp.h
@@ -186,6 +186,7 @@ enum
LINUX_MIB_TIMEWAITKILLED, /* TimeWaitKilled */
LINUX_MIB_PAWSACTIVEREJECTED, /* PAWSActiveRejected */
LINUX_MIB_PAWSESTABREJECTED, /* PAWSEstabRejected */
+ LINUX_MIB_BEYOND_WINDOW, /* BeyondWindow */
LINUX_MIB_TSECRREJECTED, /* TSEcrRejected */
LINUX_MIB_PAWS_OLD_ACK, /* PAWSOldAck */
LINUX_MIB_PAWS_TW_REJECTED, /* PAWSTimewait */
diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c
index ea2f01584379..65b0d0ab0084 100644
--- a/net/ipv4/proc.c
+++ b/net/ipv4/proc.c
@@ -189,6 +189,7 @@ static const struct snmp_mib snmp4_net_list[] = {
SNMP_MIB_ITEM("TWKilled", LINUX_MIB_TIMEWAITKILLED),
SNMP_MIB_ITEM("PAWSActive", LINUX_MIB_PAWSACTIVEREJECTED),
SNMP_MIB_ITEM("PAWSEstab", LINUX_MIB_PAWSESTABREJECTED),
+ SNMP_MIB_ITEM("BeyondWindow", LINUX_MIB_BEYOND_WINDOW),
SNMP_MIB_ITEM("TSEcrRejected", LINUX_MIB_TSECRREJECTED),
SNMP_MIB_ITEM("PAWSOldAck", LINUX_MIB_PAWS_OLD_ACK),
SNMP_MIB_ITEM("PAWSTimewait", LINUX_MIB_PAWS_TW_REJECTED),
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 9b03c44c12b8..9c5baace4b7b 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -4391,14 +4391,22 @@ static enum skb_drop_reason tcp_disordered_ack_check(const struct sock *sk,
* (borrowed from freebsd)
*/
-static enum skb_drop_reason tcp_sequence(const struct tcp_sock *tp,
+static enum skb_drop_reason tcp_sequence(const struct sock *sk,
u32 seq, u32 end_seq)
{
+ const struct tcp_sock *tp = tcp_sk(sk);
+
if (before(end_seq, tp->rcv_wup))
return SKB_DROP_REASON_TCP_OLD_SEQUENCE;
- if (after(seq, tp->rcv_nxt + tcp_receive_window(tp)))
- return SKB_DROP_REASON_TCP_INVALID_SEQUENCE;
+ if (after(end_seq, tp->rcv_nxt + tcp_receive_window(tp))) {
+ if (after(seq, tp->rcv_nxt + tcp_receive_window(tp)))
+ return SKB_DROP_REASON_TCP_INVALID_SEQUENCE;
+
+ /* Only accept this packet if receive queue is empty. */
+ if (skb_queue_len(&sk->sk_receive_queue))
+ return SKB_DROP_REASON_TCP_INVALID_END_SEQUENCE;
+ }
return SKB_NOT_DROPPED_YET;
}
@@ -4880,10 +4888,20 @@ static void tcp_ofo_queue(struct sock *sk)
static bool tcp_prune_ofo_queue(struct sock *sk, const struct sk_buff *in_skb);
static int tcp_prune_queue(struct sock *sk, const struct sk_buff *in_skb);
-static int tcp_try_rmem_schedule(struct sock *sk, struct sk_buff *skb,
+/* Check if this incoming skb can be added to socket receive queues
+ * while satisfying sk->sk_rcvbuf limit.
+ */
+static bool tcp_can_ingest(const struct sock *sk, const struct sk_buff *skb)
+{
+ unsigned int new_mem = atomic_read(&sk->sk_rmem_alloc) + skb->truesize;
+
+ return new_mem <= sk->sk_rcvbuf;
+}
+
+static int tcp_try_rmem_schedule(struct sock *sk, const struct sk_buff *skb,
unsigned int size)
{
- if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf ||
+ if (!tcp_can_ingest(sk, skb) ||
!sk_rmem_schedule(sk, skb, size)) {
if (tcp_prune_queue(sk, skb) < 0)
@@ -4915,6 +4933,7 @@ static void tcp_data_queue_ofo(struct sock *sk, struct sk_buff *skb)
return;
}
+ tcp_measure_rcv_mss(sk, skb);
/* Disable header prediction. */
tp->pred_flags = 0;
inet_csk_schedule_ack(sk);
@@ -5498,7 +5517,7 @@ static bool tcp_prune_ofo_queue(struct sock *sk, const struct sk_buff *in_skb)
tcp_drop_reason(sk, skb, SKB_DROP_REASON_TCP_OFO_QUEUE_PRUNE);
tp->ooo_last_skb = rb_to_skb(prev);
if (!prev || goal <= 0) {
- if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf &&
+ if (tcp_can_ingest(sk, skb) &&
!tcp_under_memory_pressure(sk))
break;
goal = sk->sk_rcvbuf >> 3;
@@ -5532,12 +5551,12 @@ static int tcp_prune_queue(struct sock *sk, const struct sk_buff *in_skb)
NET_INC_STATS(sock_net(sk), LINUX_MIB_PRUNECALLED);
- if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf)
+ if (!tcp_can_ingest(sk, in_skb))
tcp_clamp_window(sk);
else if (tcp_under_memory_pressure(sk))
tcp_adjust_rcv_ssthresh(sk);
- if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf)
+ if (tcp_can_ingest(sk, in_skb))
return 0;
tcp_collapse_ofo_queue(sk);
@@ -5547,7 +5566,7 @@ static int tcp_prune_queue(struct sock *sk, const struct sk_buff *in_skb)
NULL,
tp->copied_seq, tp->rcv_nxt);
- if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf)
+ if (tcp_can_ingest(sk, in_skb))
return 0;
/* Collapsing did not help, destructive actions follow.
@@ -5555,7 +5574,7 @@ static int tcp_prune_queue(struct sock *sk, const struct sk_buff *in_skb)
tcp_prune_ofo_queue(sk, in_skb);
- if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf)
+ if (tcp_can_ingest(sk, in_skb))
return 0;
/* If we are really being abused, tell the caller to silently
@@ -5881,7 +5900,7 @@ static bool tcp_validate_incoming(struct sock *sk, struct sk_buff *skb,
step1:
/* Step 1: check sequence number */
- reason = tcp_sequence(tp, TCP_SKB_CB(skb)->seq, TCP_SKB_CB(skb)->end_seq);
+ reason = tcp_sequence(sk, TCP_SKB_CB(skb)->seq, TCP_SKB_CB(skb)->end_seq);
if (reason) {
/* RFC793, page 37: "In all states except SYN-SENT, all reset
* (RST) segments are validated by checking their SEQ-fields."
@@ -5892,6 +5911,7 @@ step1:
if (!th->rst) {
if (th->syn)
goto syn_challenge;
+ NET_INC_STATS(sock_net(sk), LINUX_MIB_BEYOND_WINDOW);
if (!tcp_oow_rate_limited(sock_net(sk), skb,
LINUX_MIB_TCPACKSKIPPEDSEQ,
&tp->last_oow_ack_time))
@@ -6110,6 +6130,10 @@ void tcp_rcv_established(struct sock *sk, struct sk_buff *skb)
if (tcp_checksum_complete(skb))
goto csum_error;
+ if (after(TCP_SKB_CB(skb)->end_seq,
+ tp->rcv_nxt + tcp_receive_window(tp)))
+ goto validate;
+
if ((int)skb->truesize > sk->sk_forward_alloc)
goto step5;
@@ -6165,7 +6189,7 @@ slow_path:
/*
* Standard slow path.
*/
-
+validate:
if (!tcp_validate_incoming(sk, skb, th, 1))
return;
diff --git a/tools/testing/selftests/net/packetdrill/tcp_ooo_rcv_mss.pkt b/tools/testing/selftests/net/packetdrill/tcp_ooo_rcv_mss.pkt
new file mode 100644
index 000000000000..7e6bc5fb0c8d
--- /dev/null
+++ b/tools/testing/selftests/net/packetdrill/tcp_ooo_rcv_mss.pkt
@@ -0,0 +1,27 @@
+// SPDX-License-Identifier: GPL-2.0
+
+--mss=1000
+
+`./defaults.sh
+sysctl -q net.ipv4.tcp_rmem="4096 131072 $((32*1024*1024))"`
+
+ +0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
+ +0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
+ +0 bind(3, ..., ...) = 0
+ +0 listen(3, 1) = 0
+
+ +0 < S 0:0(0) win 65535 <mss 1000,nop,nop,sackOK,nop,wscale 7>
+ +0 > S. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK,nop,wscale 10>
+ +.1 < . 1:1(0) ack 1 win 257
+
+ +0 accept(3, ..., ...) = 4
+
+ +0 < . 2001:11001(9000) ack 1 win 257
+ +0 > . 1:1(0) ack 1 win 81 <nop,nop,sack 2001:11001>
+
+// check that ooo packet properly updates tcpi_rcv_mss
+ +0 %{ assert tcpi_rcv_mss == 1000, tcpi_rcv_mss }%
+
+ +0 < . 11001:21001(10000) ack 1 win 257
+ +0 > . 1:1(0) ack 1 win 81 <nop,nop,sack 2001:21001>
+
diff --git a/tools/testing/selftests/net/packetdrill/tcp_rcv_big_endseq.pkt b/tools/testing/selftests/net/packetdrill/tcp_rcv_big_endseq.pkt
new file mode 100644
index 000000000000..7e170b94fd36
--- /dev/null
+++ b/tools/testing/selftests/net/packetdrill/tcp_rcv_big_endseq.pkt
@@ -0,0 +1,44 @@
+// SPDX-License-Identifier: GPL-2.0
+
+--mss=1000
+
+`./defaults.sh`
+
+ 0 `nstat -n`
+
+// Establish a connection.
+ +0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
+ +0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
+ +0 setsockopt(3, SOL_SOCKET, SO_RCVBUF, [10000], 4) = 0
+ +0 bind(3, ..., ...) = 0
+ +0 listen(3, 1) = 0
+
+ +0 < S 0:0(0) win 32792 <mss 1000,nop,wscale 7>
+ +0 > S. 0:0(0) ack 1 <mss 1460,nop,wscale 0>
+ +.1 < . 1:1(0) ack 1 win 257
+
+ +0 accept(3, ..., ...) = 4
+
+ +0 < P. 1:4001(4000) ack 1 win 257
+ +0 > . 1:1(0) ack 4001 win 5000
+
+// packet in sequence : SKB_DROP_REASON_TCP_INVALID_END_SEQUENCE / LINUX_MIB_BEYOND_WINDOW
+ +0 < P. 4001:54001(50000) ack 1 win 257
+ +0 > . 1:1(0) ack 4001 win 5000
+
+// ooo packet. : SKB_DROP_REASON_TCP_INVALID_END_SEQUENCE / LINUX_MIB_BEYOND_WINDOW
+ +1 < P. 5001:55001(50000) ack 1 win 257
+ +0 > . 1:1(0) ack 4001 win 5000
+
+// SKB_DROP_REASON_TCP_INVALID_SEQUENCE / LINUX_MIB_BEYOND_WINDOW
+ +0 < P. 70001:80001(10000) ack 1 win 257
+ +0 > . 1:1(0) ack 4001 win 5000
+
+ +0 read(4, ..., 100000) = 4000
+
+// If queue is empty, accept a packet even if its end_seq is above wup + rcv_wnd
+ +0 < P. 4001:54001(50000) ack 1 win 257
+ +.040 > . 1:1(0) ack 54001 win 0
+
+// Check LINUX_MIB_BEYOND_WINDOW has been incremented 3 times.
++0 `nstat | grep TcpExtBeyondWindow | grep -q " 3 "`
diff --git a/tools/testing/selftests/net/packetdrill/tcp_rcv_toobig.pkt b/tools/testing/selftests/net/packetdrill/tcp_rcv_toobig.pkt
new file mode 100644
index 000000000000..f575c0ff89da
--- /dev/null
+++ b/tools/testing/selftests/net/packetdrill/tcp_rcv_toobig.pkt
@@ -0,0 +1,33 @@
+// SPDX-License-Identifier: GPL-2.0
+
+--mss=1000
+
+`./defaults.sh`
+
+ 0 `nstat -n`
+
+// Establish a connection.
+ +0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
+ +0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
+ +0 setsockopt(3, SOL_SOCKET, SO_RCVBUF, [20000], 4) = 0
+ +0 bind(3, ..., ...) = 0
+ +0 listen(3, 1) = 0
+
+ +0 < S 0:0(0) win 32792 <mss 1000,nop,wscale 7>
+ +0 > S. 0:0(0) ack 1 win 18980 <mss 1460,nop,wscale 0>
+ +.1 < . 1:1(0) ack 1 win 257
+
+ +0 accept(3, ..., ...) = 4
+
+ +0 < P. 1:20001(20000) ack 1 win 257
+ +.04 > . 1:1(0) ack 20001 win 18000
+
+ +0 setsockopt(4, SOL_SOCKET, SO_RCVBUF, [12000], 4) = 0
+ +0 < P. 20001:80001(60000) ack 1 win 257
+ +0 > . 1:1(0) ack 20001 win 18000
+
+ +0 read(4, ..., 20000) = 20000
+// A too big packet is accepted if the receive queue is empty
+ +0 < P. 20001:80001(60000) ack 1 win 257
+ +0 > . 1:1(0) ack 80001 win 0
+
generated by cgit (git 2.34.1) at 2026-01-08 10:52:14 +0000