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-rw-r--r--include/net/tcp.h7
-rw-r--r--net/ipv4/tcp.c3
-rw-r--r--net/ipv4/tcp_input.c15
-rw-r--r--net/ipv4/tcp_ipv4.c3
-rw-r--r--net/ipv6/tcp_ipv6.c3
5 files changed, 14 insertions, 17 deletions
diff --git a/include/net/tcp.h b/include/net/tcp.h
index ecbadcb3a744..98848db62894 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -65,8 +65,6 @@ static inline void tcp_orphan_count_dec(void)
this_cpu_dec(tcp_orphan_count);
}
-DECLARE_PER_CPU(u32, tcp_tw_isn);
-
void tcp_time_wait(struct sock *sk, int state, int timeo);
#define MAX_TCP_HEADER L1_CACHE_ALIGN(128 + MAX_HEADER)
@@ -1102,10 +1100,13 @@ struct tcp_skb_cb {
__u32 seq; /* Starting sequence number */
__u32 end_seq; /* SEQ + FIN + SYN + datalen */
union {
- /* Note :
+ /* Notes :
+ * tcp_tw_isn is used in input path only
+ * (isn chosen by tcp_timewait_state_process())
* tcp_gso_segs/size are used in write queue only,
* cf tcp_skb_pcount()/tcp_skb_mss()
*/
+ u32 tcp_tw_isn;
struct {
u16 tcp_gso_segs;
u16 tcp_gso_size;
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 432fa28e47d4..389a7cc17110 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -299,9 +299,6 @@ enum {
DEFINE_PER_CPU(unsigned int, tcp_orphan_count);
EXPORT_PER_CPU_SYMBOL_GPL(tcp_orphan_count);
-DEFINE_PER_CPU(u32, tcp_tw_isn);
-EXPORT_PER_CPU_SYMBOL_GPL(tcp_tw_isn);
-
long sysctl_tcp_mem[3] __read_mostly;
DEFINE_PER_CPU(int, tcp_memory_per_cpu_fw_alloc);
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index d5c9e65d9760..de9f68a9c0cf 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -7589,6 +7589,7 @@ int tcp_conn_request(struct request_sock_ops *rsk_ops,
struct sock *sk, struct sk_buff *skb)
{
struct tcp_fastopen_cookie foc = { .len = -1 };
+ u32 isn = TCP_SKB_CB(skb)->tcp_tw_isn;
struct tcp_options_received tmp_opt;
const struct tcp_sock *tp = tcp_sk(sk);
struct net *net = sock_net(sk);
@@ -7599,20 +7600,16 @@ int tcp_conn_request(struct request_sock_ops *rsk_ops,
struct dst_entry *dst;
struct flowi fl;
u8 syncookies;
- u32 isn;
#ifdef CONFIG_TCP_AO
const struct tcp_ao_hdr *aoh;
#endif
- isn = __this_cpu_read(tcp_tw_isn);
- if (isn) {
- /* TW buckets are converted to open requests without
- * limitations, they conserve resources and peer is
- * evidently real one.
- */
- __this_cpu_write(tcp_tw_isn, 0);
- } else {
+ /* If isn is non-zero, this SYN originally matched a TIME_WAIT socket.
+ * TW sockets are converted to open requests without limitations,
+ * we skip the queue limits and syncookie checks in the block below.
+ */
+ if (!isn) {
syncookies = READ_ONCE(net->ipv4.sysctl_tcp_syncookies);
if (syncookies == 2 || inet_csk_reqsk_queue_is_full(sk)) {
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index c0526cc03980..fdc81150ff6c 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -2198,6 +2198,7 @@ lookup:
}
}
+ isn = 0;
process:
if (static_branch_unlikely(&ip4_min_ttl)) {
/* min_ttl can be changed concurrently from do_ip_setsockopt() */
@@ -2227,6 +2228,7 @@ process:
th = (const struct tcphdr *)skb->data;
iph = ip_hdr(skb);
tcp_v4_fill_cb(skb, iph, th);
+ TCP_SKB_CB(skb)->tcp_tw_isn = isn;
skb->dev = NULL;
@@ -2313,7 +2315,6 @@ do_time_wait:
sk = sk2;
tcp_v4_restore_cb(skb);
refcounted = false;
- __this_cpu_write(tcp_tw_isn, isn);
goto process;
}
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index d13d49bfef19..36d75fb50a70 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1839,6 +1839,7 @@ lookup:
}
}
+ isn = 0;
process:
if (static_branch_unlikely(&ip6_min_hopcount)) {
/* min_hopcount can be changed concurrently from do_ipv6_setsockopt() */
@@ -1868,6 +1869,7 @@ process:
th = (const struct tcphdr *)skb->data;
hdr = ipv6_hdr(skb);
tcp_v6_fill_cb(skb, hdr, th);
+ TCP_SKB_CB(skb)->tcp_tw_isn = isn;
skb->dev = NULL;
@@ -1956,7 +1958,6 @@ do_time_wait:
sk = sk2;
tcp_v6_restore_cb(skb);
refcounted = false;
- __this_cpu_write(tcp_tw_isn, isn);
goto process;
}