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Diffstat (limited to 'net/ipv4/tcp_output.c')
-rw-r--r--net/ipv4/tcp_output.c109
1 files changed, 57 insertions, 52 deletions
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 1100ffe4a722..9bfc39ff2285 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -357,14 +357,10 @@ static void tcp_ecn_clear_syn(struct sock *sk, struct sk_buff *skb)
}
static void
-tcp_ecn_make_synack(const struct request_sock *req, struct tcphdr *th,
- struct sock *sk)
+tcp_ecn_make_synack(const struct request_sock *req, struct tcphdr *th)
{
- if (inet_rsk(req)->ecn_ok) {
+ if (inet_rsk(req)->ecn_ok)
th->ece = 1;
- if (tcp_ca_needs_ecn(sk))
- INET_ECN_xmit(sk);
- }
}
/* Set up ECN state for a packet on a ESTABLISHED socket that is about to
@@ -612,12 +608,11 @@ static unsigned int tcp_syn_options(struct sock *sk, struct sk_buff *skb,
}
/* Set up TCP options for SYN-ACKs. */
-static unsigned int tcp_synack_options(struct sock *sk,
- struct request_sock *req,
- unsigned int mss, struct sk_buff *skb,
- struct tcp_out_options *opts,
- const struct tcp_md5sig_key *md5,
- struct tcp_fastopen_cookie *foc)
+static unsigned int tcp_synack_options(struct request_sock *req,
+ unsigned int mss, struct sk_buff *skb,
+ struct tcp_out_options *opts,
+ const struct tcp_md5sig_key *md5,
+ struct tcp_fastopen_cookie *foc)
{
struct inet_request_sock *ireq = inet_rsk(req);
unsigned int remaining = MAX_TCP_OPTION_SPACE;
@@ -1827,7 +1822,7 @@ static bool tcp_tso_should_defer(struct sock *sk, struct sk_buff *skb,
/* Ok, it looks like it is advisable to defer. */
- if (cong_win < send_win && cong_win < skb->len)
+ if (cong_win < send_win && cong_win <= skb->len)
*is_cwnd_limited = true;
return true;
@@ -2060,7 +2055,6 @@ static bool tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle,
cwnd_quota = tcp_cwnd_test(tp, skb);
if (!cwnd_quota) {
- is_cwnd_limited = true;
if (push_one == 2)
/* Force out a loss probe pkt. */
cwnd_quota = 1;
@@ -2142,6 +2136,7 @@ repair:
/* Send one loss probe per tail loss episode. */
if (push_one != 2)
tcp_schedule_loss_probe(sk);
+ is_cwnd_limited |= (tcp_packets_in_flight(tp) >= tp->snd_cwnd);
tcp_cwnd_validate(sk, is_cwnd_limited);
return false;
}
@@ -2165,7 +2160,7 @@ bool tcp_schedule_loss_probe(struct sock *sk)
/* Don't do any loss probe on a Fast Open connection before 3WHS
* finishes.
*/
- if (sk->sk_state == TCP_SYN_RECV)
+ if (tp->fastopen_rsk)
return false;
/* TLP is only scheduled when next timer event is RTO. */
@@ -2175,7 +2170,7 @@ bool tcp_schedule_loss_probe(struct sock *sk)
/* Schedule a loss probe in 2*RTT for SACK capable connections
* in Open state, that are either limited by cwnd or application.
*/
- if (sysctl_tcp_early_retrans < 3 || !tp->srtt_us || !tp->packets_out ||
+ if (sysctl_tcp_early_retrans < 3 || !tp->packets_out ||
!tcp_is_sack(tp) || inet_csk(sk)->icsk_ca_state != TCP_CA_Open)
return false;
@@ -2184,9 +2179,10 @@ bool tcp_schedule_loss_probe(struct sock *sk)
return false;
/* Probe timeout is at least 1.5*rtt + TCP_DELACK_MAX to account
- * for delayed ack when there's one outstanding packet.
+ * for delayed ack when there's one outstanding packet. If no RTT
+ * sample is available then probe after TCP_TIMEOUT_INIT.
*/
- timeout = rtt << 1;
+ timeout = rtt << 1 ? : TCP_TIMEOUT_INIT;
if (tp->packets_out == 1)
timeout = max_t(u32, timeout,
(rtt + (rtt >> 1) + TCP_DELACK_MAX));
@@ -2659,8 +2655,6 @@ int tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb)
net_dbg_ratelimited("retrans_out leaked\n");
}
#endif
- if (!tp->retrans_out)
- tp->lost_retrans_low = tp->snd_nxt;
TCP_SKB_CB(skb)->sacked |= TCPCB_RETRANS;
tp->retrans_out += tcp_skb_pcount(skb);
@@ -2668,10 +2662,6 @@ int tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb)
if (!tp->retrans_stamp)
tp->retrans_stamp = tcp_skb_timestamp(skb);
- /* snd_nxt is stored to detect loss of retransmitted segment,
- * see tcp_input.c tcp_sacktag_write_queue().
- */
- TCP_SKB_CB(skb)->ack_seq = tp->snd_nxt;
} else if (err != -EBUSY) {
NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPRETRANSFAIL);
}
@@ -2949,20 +2939,22 @@ int tcp_send_synack(struct sock *sk)
* Allocate one skb and build a SYNACK packet.
* @dst is consumed : Caller should not use it again.
*/
-struct sk_buff *tcp_make_synack(struct sock *sk, struct dst_entry *dst,
+struct sk_buff *tcp_make_synack(const struct sock *sk, struct dst_entry *dst,
struct request_sock *req,
- struct tcp_fastopen_cookie *foc)
+ struct tcp_fastopen_cookie *foc,
+ bool attach_req)
{
- struct tcp_out_options opts;
struct inet_request_sock *ireq = inet_rsk(req);
- struct tcp_sock *tp = tcp_sk(sk);
- struct tcphdr *th;
- struct sk_buff *skb;
+ const struct tcp_sock *tp = tcp_sk(sk);
struct tcp_md5sig_key *md5 = NULL;
+ struct tcp_out_options opts;
+ struct sk_buff *skb;
int tcp_header_size;
+ struct tcphdr *th;
+ u16 user_mss;
int mss;
- skb = sock_wmalloc(sk, MAX_TCP_HEADER, 1, GFP_ATOMIC);
+ skb = alloc_skb(MAX_TCP_HEADER, GFP_ATOMIC);
if (unlikely(!skb)) {
dst_release(dst);
return NULL;
@@ -2970,11 +2962,21 @@ struct sk_buff *tcp_make_synack(struct sock *sk, struct dst_entry *dst,
/* Reserve space for headers. */
skb_reserve(skb, MAX_TCP_HEADER);
+ if (attach_req) {
+ skb_set_owner_w(skb, req_to_sk(req));
+ } else {
+ /* sk is a const pointer, because we want to express multiple
+ * cpu might call us concurrently.
+ * sk->sk_wmem_alloc in an atomic, we can promote to rw.
+ */
+ skb_set_owner_w(skb, (struct sock *)sk);
+ }
skb_dst_set(skb, dst);
mss = dst_metric_advmss(dst);
- if (tp->rx_opt.user_mss && tp->rx_opt.user_mss < mss)
- mss = tp->rx_opt.user_mss;
+ user_mss = READ_ONCE(tp->rx_opt.user_mss);
+ if (user_mss && user_mss < mss)
+ mss = user_mss;
memset(&opts, 0, sizeof(opts));
#ifdef CONFIG_SYN_COOKIES
@@ -2988,8 +2990,9 @@ struct sk_buff *tcp_make_synack(struct sock *sk, struct dst_entry *dst,
rcu_read_lock();
md5 = tcp_rsk(req)->af_specific->req_md5_lookup(sk, req_to_sk(req));
#endif
- tcp_header_size = tcp_synack_options(sk, req, mss, skb, &opts, md5,
- foc) + sizeof(*th);
+ skb_set_hash(skb, tcp_rsk(req)->txhash, PKT_HASH_TYPE_L4);
+ tcp_header_size = tcp_synack_options(req, mss, skb, &opts, md5, foc) +
+ sizeof(*th);
skb_push(skb, tcp_header_size);
skb_reset_transport_header(skb);
@@ -2998,7 +3001,7 @@ struct sk_buff *tcp_make_synack(struct sock *sk, struct dst_entry *dst,
memset(th, 0, sizeof(struct tcphdr));
th->syn = 1;
th->ack = 1;
- tcp_ecn_make_synack(req, th, sk);
+ tcp_ecn_make_synack(req, th);
th->source = htons(ireq->ir_num);
th->dest = ireq->ir_rmt_port;
/* Setting of flags are superfluous here for callers (and ECE is
@@ -3012,8 +3015,8 @@ struct sk_buff *tcp_make_synack(struct sock *sk, struct dst_entry *dst,
th->ack_seq = htonl(tcp_rsk(req)->rcv_nxt);
/* RFC1323: The window in SYN & SYN/ACK segments is never scaled. */
- th->window = htons(min(req->rcv_wnd, 65535U));
- tcp_options_write((__be32 *)(th + 1), tp, &opts);
+ th->window = htons(min(req->rsk_rcv_wnd, 65535U));
+ tcp_options_write((__be32 *)(th + 1), NULL, &opts);
th->doff = (tcp_header_size >> 2);
TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_OUTSEGS);
@@ -3147,7 +3150,7 @@ static int tcp_send_syn_data(struct sock *sk, struct sk_buff *syn)
{
struct tcp_sock *tp = tcp_sk(sk);
struct tcp_fastopen_request *fo = tp->fastopen_req;
- int syn_loss = 0, space, err = 0, copied;
+ int syn_loss = 0, space, err = 0;
unsigned long last_syn_loss = 0;
struct sk_buff *syn_data;
@@ -3185,17 +3188,18 @@ static int tcp_send_syn_data(struct sock *sk, struct sk_buff *syn)
goto fallback;
syn_data->ip_summed = CHECKSUM_PARTIAL;
memcpy(syn_data->cb, syn->cb, sizeof(syn->cb));
- copied = copy_from_iter(skb_put(syn_data, space), space,
- &fo->data->msg_iter);
- if (unlikely(!copied)) {
- kfree_skb(syn_data);
- goto fallback;
- }
- if (copied != space) {
- skb_trim(syn_data, copied);
- space = copied;
+ if (space) {
+ int copied = copy_from_iter(skb_put(syn_data, space), space,
+ &fo->data->msg_iter);
+ if (unlikely(!copied)) {
+ kfree_skb(syn_data);
+ goto fallback;
+ }
+ if (copied != space) {
+ skb_trim(syn_data, copied);
+ space = copied;
+ }
}
-
/* No more data pending in inet_wait_for_connect() */
if (space == fo->size)
fo->data = NULL;
@@ -3405,7 +3409,7 @@ static int tcp_xmit_probe_skb(struct sock *sk, int urgent, int mib)
*/
tcp_init_nondata_skb(skb, tp->snd_una - !urgent, TCPHDR_ACK);
skb_mstamp_get(&skb->skb_mstamp);
- NET_INC_STATS_BH(sock_net(sk), mib);
+ NET_INC_STATS(sock_net(sk), mib);
return tcp_transmit_skb(sk, skb, 0, GFP_ATOMIC);
}
@@ -3500,13 +3504,14 @@ void tcp_send_probe0(struct sock *sk)
TCP_RTO_MAX);
}
-int tcp_rtx_synack(struct sock *sk, struct request_sock *req)
+int tcp_rtx_synack(const struct sock *sk, struct request_sock *req)
{
const struct tcp_request_sock_ops *af_ops = tcp_rsk(req)->af_specific;
struct flowi fl;
int res;
- res = af_ops->send_synack(sk, NULL, &fl, req, 0, NULL);
+ tcp_rsk(req)->txhash = net_tx_rndhash();
+ res = af_ops->send_synack(sk, NULL, &fl, req, NULL, true);
if (!res) {
TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_RETRANSSEGS);
NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPSYNRETRANS);
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.