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Diffstat (limited to 'net/ipv4/tcp_input.c')
-rw-r--r--net/ipv4/tcp_input.c113
1 files changed, 60 insertions, 53 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index a12b455928e5..075ab4d5af5e 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -81,6 +81,7 @@ int sysctl_tcp_window_scaling __read_mostly = 1;
int sysctl_tcp_sack __read_mostly = 1;
int sysctl_tcp_fack __read_mostly = 1;
int sysctl_tcp_reordering __read_mostly = TCP_FASTRETRANS_THRESH;
+int sysctl_tcp_max_reordering __read_mostly = 300;
EXPORT_SYMBOL(sysctl_tcp_reordering);
int sysctl_tcp_dsack __read_mostly = 1;
int sysctl_tcp_app_win __read_mostly = 31;
@@ -833,7 +834,7 @@ static void tcp_update_reordering(struct sock *sk, const int metric,
if (metric > tp->reordering) {
int mib_idx;
- tp->reordering = min(TCP_MAX_REORDERING, metric);
+ tp->reordering = min(sysctl_tcp_max_reordering, metric);
/* This exciting event is worth to be remembered. 8) */
if (ts)
@@ -2315,6 +2316,35 @@ static inline bool tcp_packet_delayed(const struct tcp_sock *tp)
/* Undo procedures. */
+/* We can clear retrans_stamp when there are no retransmissions in the
+ * window. It would seem that it is trivially available for us in
+ * tp->retrans_out, however, that kind of assumptions doesn't consider
+ * what will happen if errors occur when sending retransmission for the
+ * second time. ...It could the that such segment has only
+ * TCPCB_EVER_RETRANS set at the present time. It seems that checking
+ * the head skb is enough except for some reneging corner cases that
+ * are not worth the effort.
+ *
+ * Main reason for all this complexity is the fact that connection dying
+ * time now depends on the validity of the retrans_stamp, in particular,
+ * that successive retransmissions of a segment must not advance
+ * retrans_stamp under any conditions.
+ */
+static bool tcp_any_retrans_done(const struct sock *sk)
+{
+ const struct tcp_sock *tp = tcp_sk(sk);
+ struct sk_buff *skb;
+
+ if (tp->retrans_out)
+ return true;
+
+ skb = tcp_write_queue_head(sk);
+ if (unlikely(skb && TCP_SKB_CB(skb)->sacked & TCPCB_EVER_RETRANS))
+ return true;
+
+ return false;
+}
+
#if FASTRETRANS_DEBUG > 1
static void DBGUNDO(struct sock *sk, const char *msg)
{
@@ -2410,6 +2440,8 @@ static bool tcp_try_undo_recovery(struct sock *sk)
* is ACKed. For Reno it is MUST to prevent false
* fast retransmits (RFC2582). SACK TCP is safe. */
tcp_moderate_cwnd(tp);
+ if (!tcp_any_retrans_done(sk))
+ tp->retrans_stamp = 0;
return true;
}
tcp_set_ca_state(sk, TCP_CA_Open);
@@ -2430,35 +2462,6 @@ static bool tcp_try_undo_dsack(struct sock *sk)
return false;
}
-/* We can clear retrans_stamp when there are no retransmissions in the
- * window. It would seem that it is trivially available for us in
- * tp->retrans_out, however, that kind of assumptions doesn't consider
- * what will happen if errors occur when sending retransmission for the
- * second time. ...It could the that such segment has only
- * TCPCB_EVER_RETRANS set at the present time. It seems that checking
- * the head skb is enough except for some reneging corner cases that
- * are not worth the effort.
- *
- * Main reason for all this complexity is the fact that connection dying
- * time now depends on the validity of the retrans_stamp, in particular,
- * that successive retransmissions of a segment must not advance
- * retrans_stamp under any conditions.
- */
-static bool tcp_any_retrans_done(const struct sock *sk)
-{
- const struct tcp_sock *tp = tcp_sk(sk);
- struct sk_buff *skb;
-
- if (tp->retrans_out)
- return true;
-
- skb = tcp_write_queue_head(sk);
- if (unlikely(skb && TCP_SKB_CB(skb)->sacked & TCPCB_EVER_RETRANS))
- return true;
-
- return false;
-}
-
/* Undo during loss recovery after partial ACK or using F-RTO. */
static bool tcp_try_undo_loss(struct sock *sk, bool frto_undo)
{
@@ -4365,7 +4368,7 @@ int tcp_send_rcvq(struct sock *sk, struct msghdr *msg, size_t size)
if (tcp_try_rmem_schedule(sk, skb, skb->truesize))
goto err_free;
- if (memcpy_fromiovec(skb_put(skb, size), msg->msg_iov, size))
+ if (memcpy_from_msg(skb_put(skb, size), msg, size))
goto err_free;
TCP_SKB_CB(skb)->seq = tcp_sk(sk)->rcv_nxt;
@@ -4418,7 +4421,7 @@ static void tcp_data_queue(struct sock *sk, struct sk_buff *skb)
__set_current_state(TASK_RUNNING);
local_bh_enable();
- if (!skb_copy_datagram_iovec(skb, 0, tp->ucopy.iov, chunk)) {
+ if (!skb_copy_datagram_msg(skb, 0, tp->ucopy.msg, chunk)) {
tp->ucopy.len -= chunk;
tp->copied_seq += chunk;
eaten = (chunk == skb->len);
@@ -4938,10 +4941,9 @@ static int tcp_copy_to_iovec(struct sock *sk, struct sk_buff *skb, int hlen)
local_bh_enable();
if (skb_csum_unnecessary(skb))
- err = skb_copy_datagram_iovec(skb, hlen, tp->ucopy.iov, chunk);
+ err = skb_copy_datagram_msg(skb, hlen, tp->ucopy.msg, chunk);
else
- err = skb_copy_and_csum_datagram_iovec(skb, hlen,
- tp->ucopy.iov);
+ err = skb_copy_and_csum_datagram_msg(skb, hlen, tp->ucopy.msg);
if (!err) {
tp->ucopy.len -= chunk;
@@ -5028,7 +5030,7 @@ static bool tcp_validate_incoming(struct sock *sk, struct sk_buff *skb,
/* step 3: check security and precedence [ignored] */
/* step 4: Check for a SYN
- * RFC 5691 4.2 : Send a challenge ack
+ * RFC 5961 4.2 : Send a challenge ack
*/
if (th->syn) {
syn_challenge:
@@ -5229,7 +5231,7 @@ slow_path:
if (len < (th->doff << 2) || tcp_checksum_complete_user(sk, skb))
goto csum_error;
- if (!th->ack && !th->rst)
+ if (!th->ack && !th->rst && !th->syn)
goto discard;
/*
@@ -5648,7 +5650,7 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
goto discard;
}
- if (!th->ack && !th->rst)
+ if (!th->ack && !th->rst && !th->syn)
goto discard;
if (!tcp_validate_incoming(sk, skb, th, 0))
@@ -5851,12 +5853,12 @@ static inline void pr_drop_req(struct request_sock *req, __u16 port, int family)
struct inet_request_sock *ireq = inet_rsk(req);
if (family == AF_INET)
- LIMIT_NETDEBUG(KERN_DEBUG pr_fmt("drop open request from %pI4/%u\n"),
- &ireq->ir_rmt_addr, port);
+ net_dbg_ratelimited("drop open request from %pI4/%u\n",
+ &ireq->ir_rmt_addr, port);
#if IS_ENABLED(CONFIG_IPV6)
else if (family == AF_INET6)
- LIMIT_NETDEBUG(KERN_DEBUG pr_fmt("drop open request from %pI6/%u\n"),
- &ireq->ir_v6_rmt_addr, port);
+ net_dbg_ratelimited("drop open request from %pI6/%u\n",
+ &ireq->ir_v6_rmt_addr, port);
#endif
}
@@ -5865,7 +5867,7 @@ static inline void pr_drop_req(struct request_sock *req, __u16 port, int family)
* If we receive a SYN packet with these bits set, it means a
* network is playing bad games with TOS bits. In order to
* avoid possible false congestion notifications, we disable
- * TCP ECN negociation.
+ * TCP ECN negotiation.
*
* Exception: tcp_ca wants ECN. This is required for DCTCP
* congestion control; it requires setting ECT on all packets,
@@ -5875,20 +5877,22 @@ static inline void pr_drop_req(struct request_sock *req, __u16 port, int family)
*/
static void tcp_ecn_create_request(struct request_sock *req,
const struct sk_buff *skb,
- const struct sock *listen_sk)
+ const struct sock *listen_sk,
+ const struct dst_entry *dst)
{
const struct tcphdr *th = tcp_hdr(skb);
const struct net *net = sock_net(listen_sk);
bool th_ecn = th->ece && th->cwr;
- bool ect, need_ecn;
+ bool ect, need_ecn, ecn_ok;
if (!th_ecn)
return;
ect = !INET_ECN_is_not_ect(TCP_SKB_CB(skb)->ip_dsfield);
need_ecn = tcp_ca_needs_ecn(listen_sk);
+ ecn_ok = net->ipv4.sysctl_tcp_ecn || dst_feature(dst, RTAX_FEATURE_ECN);
- if (!ect && !need_ecn && net->ipv4.sysctl_tcp_ecn)
+ if (!ect && !need_ecn && ecn_ok)
inet_rsk(req)->ecn_ok = 1;
else if (ect && need_ecn)
inet_rsk(req)->ecn_ok = 1;
@@ -5953,13 +5957,7 @@ int tcp_conn_request(struct request_sock_ops *rsk_ops,
if (security_inet_conn_request(sk, skb, req))
goto drop_and_free;
- if (!want_cookie || tmp_opt.tstamp_ok)
- tcp_ecn_create_request(req, skb, sk);
-
- if (want_cookie) {
- isn = cookie_init_sequence(af_ops, sk, skb, &req->mss);
- req->cookie_ts = tmp_opt.tstamp_ok;
- } else if (!isn) {
+ if (!want_cookie && !isn) {
/* VJ's idea. We save last timestamp seen
* from the destination in peer table, when entering
* state TIME-WAIT, and check against it before
@@ -6007,6 +6005,15 @@ int tcp_conn_request(struct request_sock_ops *rsk_ops,
goto drop_and_free;
}
+ tcp_ecn_create_request(req, skb, sk, dst);
+
+ if (want_cookie) {
+ isn = cookie_init_sequence(af_ops, sk, skb, &req->mss);
+ req->cookie_ts = tmp_opt.tstamp_ok;
+ if (!tmp_opt.tstamp_ok)
+ inet_rsk(req)->ecn_ok = 0;
+ }
+
tcp_rsk(req)->snt_isn = isn;
tcp_openreq_init_rwin(req, sk, dst);
fastopen = !want_cookie &&
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.