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Diffstat (limited to 'net/ipv4/tcp_output.c')
-rw-r--r--net/ipv4/tcp_output.c152
1 files changed, 90 insertions, 62 deletions
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 376b2cfbb685..803cbfe82fbc 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -34,6 +34,8 @@
*
*/
+#define pr_fmt(fmt) "TCP: " fmt
+
#include <net/tcp.h>
#include <linux/compiler.h>
@@ -78,9 +80,8 @@ static void tcp_event_new_data_sent(struct sock *sk, const struct sk_buff *skb)
tp->frto_counter = 3;
tp->packets_out += tcp_skb_pcount(skb);
- if (!prior_packets)
- inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
- inet_csk(sk)->icsk_rto, TCP_RTO_MAX);
+ if (!prior_packets || tp->early_retrans_delayed)
+ tcp_rearm_rto(sk);
}
/* SND.NXT, if window was not shrunk.
@@ -369,7 +370,7 @@ static void tcp_init_nondata_skb(struct sk_buff *skb, u32 seq, u8 flags)
TCP_SKB_CB(skb)->end_seq = seq;
}
-static inline int tcp_urg_mode(const struct tcp_sock *tp)
+static inline bool tcp_urg_mode(const struct tcp_sock *tp)
{
return tp->snd_una != tp->snd_up;
}
@@ -563,13 +564,13 @@ static void tcp_options_write(__be32 *ptr, struct tcp_sock *tp,
/* Compute TCP options for SYN packets. This is not the final
* network wire format yet.
*/
-static unsigned tcp_syn_options(struct sock *sk, struct sk_buff *skb,
+static unsigned int tcp_syn_options(struct sock *sk, struct sk_buff *skb,
struct tcp_out_options *opts,
struct tcp_md5sig_key **md5)
{
struct tcp_sock *tp = tcp_sk(sk);
struct tcp_cookie_values *cvp = tp->cookie_values;
- unsigned remaining = MAX_TCP_OPTION_SPACE;
+ unsigned int remaining = MAX_TCP_OPTION_SPACE;
u8 cookie_size = (!tp->rx_opt.cookie_out_never && cvp != NULL) ?
tcp_cookie_size_check(cvp->cookie_desired) :
0;
@@ -663,15 +664,15 @@ static unsigned tcp_syn_options(struct sock *sk, struct sk_buff *skb,
}
/* Set up TCP options for SYN-ACKs. */
-static unsigned tcp_synack_options(struct sock *sk,
+static unsigned int tcp_synack_options(struct sock *sk,
struct request_sock *req,
- unsigned mss, struct sk_buff *skb,
+ unsigned int mss, struct sk_buff *skb,
struct tcp_out_options *opts,
struct tcp_md5sig_key **md5,
struct tcp_extend_values *xvp)
{
struct inet_request_sock *ireq = inet_rsk(req);
- unsigned remaining = MAX_TCP_OPTION_SPACE;
+ unsigned int remaining = MAX_TCP_OPTION_SPACE;
u8 cookie_plus = (xvp != NULL && !xvp->cookie_out_never) ?
xvp->cookie_plus :
0;
@@ -742,13 +743,13 @@ static unsigned tcp_synack_options(struct sock *sk,
/* Compute TCP options for ESTABLISHED sockets. This is not the
* final wire format yet.
*/
-static unsigned tcp_established_options(struct sock *sk, struct sk_buff *skb,
+static unsigned int tcp_established_options(struct sock *sk, struct sk_buff *skb,
struct tcp_out_options *opts,
struct tcp_md5sig_key **md5)
{
struct tcp_skb_cb *tcb = skb ? TCP_SKB_CB(skb) : NULL;
struct tcp_sock *tp = tcp_sk(sk);
- unsigned size = 0;
+ unsigned int size = 0;
unsigned int eff_sacks;
#ifdef CONFIG_TCP_MD5SIG
@@ -770,9 +771,9 @@ static unsigned tcp_established_options(struct sock *sk, struct sk_buff *skb,
eff_sacks = tp->rx_opt.num_sacks + tp->rx_opt.dsack;
if (unlikely(eff_sacks)) {
- const unsigned remaining = MAX_TCP_OPTION_SPACE - size;
+ const unsigned int remaining = MAX_TCP_OPTION_SPACE - size;
opts->num_sack_blocks =
- min_t(unsigned, eff_sacks,
+ min_t(unsigned int, eff_sacks,
(remaining - TCPOLEN_SACK_BASE_ALIGNED) /
TCPOLEN_SACK_PERBLOCK);
size += TCPOLEN_SACK_BASE_ALIGNED +
@@ -801,7 +802,7 @@ static int tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, int clone_it,
struct tcp_sock *tp;
struct tcp_skb_cb *tcb;
struct tcp_out_options opts;
- unsigned tcp_options_size, tcp_header_size;
+ unsigned int tcp_options_size, tcp_header_size;
struct tcp_md5sig_key *md5;
struct tcphdr *th;
int err;
@@ -1096,6 +1097,7 @@ static void __pskb_trim_head(struct sk_buff *skb, int len)
eat = min_t(int, len, skb_headlen(skb));
if (eat) {
__skb_pull(skb, eat);
+ skb->avail_size -= eat;
len -= eat;
if (!len)
return;
@@ -1149,7 +1151,7 @@ int tcp_trim_head(struct sock *sk, struct sk_buff *skb, u32 len)
}
/* Calculate MSS. Not accounting for SACKs here. */
-int tcp_mtu_to_mss(const struct sock *sk, int pmtu)
+int tcp_mtu_to_mss(struct sock *sk, int pmtu)
{
const struct tcp_sock *tp = tcp_sk(sk);
const struct inet_connection_sock *icsk = inet_csk(sk);
@@ -1160,6 +1162,14 @@ int tcp_mtu_to_mss(const struct sock *sk, int pmtu)
*/
mss_now = pmtu - icsk->icsk_af_ops->net_header_len - sizeof(struct tcphdr);
+ /* IPv6 adds a frag_hdr in case RTAX_FEATURE_ALLFRAG is set */
+ if (icsk->icsk_af_ops->net_frag_header_len) {
+ const struct dst_entry *dst = __sk_dst_get(sk);
+
+ if (dst && dst_allfrag(dst))
+ mss_now -= icsk->icsk_af_ops->net_frag_header_len;
+ }
+
/* Clamp it (mss_clamp does not include tcp options) */
if (mss_now > tp->rx_opt.mss_clamp)
mss_now = tp->rx_opt.mss_clamp;
@@ -1178,7 +1188,7 @@ int tcp_mtu_to_mss(const struct sock *sk, int pmtu)
}
/* Inverse of above */
-int tcp_mss_to_mtu(const struct sock *sk, int mss)
+int tcp_mss_to_mtu(struct sock *sk, int mss)
{
const struct tcp_sock *tp = tcp_sk(sk);
const struct inet_connection_sock *icsk = inet_csk(sk);
@@ -1189,6 +1199,13 @@ int tcp_mss_to_mtu(const struct sock *sk, int mss)
icsk->icsk_ext_hdr_len +
icsk->icsk_af_ops->net_header_len;
+ /* IPv6 adds a frag_hdr in case RTAX_FEATURE_ALLFRAG is set */
+ if (icsk->icsk_af_ops->net_frag_header_len) {
+ const struct dst_entry *dst = __sk_dst_get(sk);
+
+ if (dst && dst_allfrag(dst))
+ mtu += icsk->icsk_af_ops->net_frag_header_len;
+ }
return mtu;
}
@@ -1258,7 +1275,7 @@ unsigned int tcp_current_mss(struct sock *sk)
const struct tcp_sock *tp = tcp_sk(sk);
const struct dst_entry *dst = __sk_dst_get(sk);
u32 mss_now;
- unsigned header_len;
+ unsigned int header_len;
struct tcp_out_options opts;
struct tcp_md5sig_key *md5;
@@ -1374,33 +1391,33 @@ static int tcp_init_tso_segs(const struct sock *sk, struct sk_buff *skb,
}
/* Minshall's variant of the Nagle send check. */
-static inline int tcp_minshall_check(const struct tcp_sock *tp)
+static inline bool tcp_minshall_check(const struct tcp_sock *tp)
{
return after(tp->snd_sml, tp->snd_una) &&
!after(tp->snd_sml, tp->snd_nxt);
}
-/* Return 0, if packet can be sent now without violation Nagle's rules:
+/* Return false, if packet can be sent now without violation Nagle's rules:
* 1. It is full sized.
* 2. Or it contains FIN. (already checked by caller)
* 3. Or TCP_CORK is not set, and TCP_NODELAY is set.
* 4. Or TCP_CORK is not set, and all sent packets are ACKed.
* With Minshall's modification: all sent small packets are ACKed.
*/
-static inline int tcp_nagle_check(const struct tcp_sock *tp,
+static inline bool tcp_nagle_check(const struct tcp_sock *tp,
const struct sk_buff *skb,
- unsigned mss_now, int nonagle)
+ unsigned int mss_now, int nonagle)
{
return skb->len < mss_now &&
((nonagle & TCP_NAGLE_CORK) ||
(!nonagle && tp->packets_out && tcp_minshall_check(tp)));
}
-/* Return non-zero if the Nagle test allows this packet to be
+/* Return true if the Nagle test allows this packet to be
* sent now.
*/
-static inline int tcp_nagle_test(const struct tcp_sock *tp, const struct sk_buff *skb,
- unsigned int cur_mss, int nonagle)
+static inline bool tcp_nagle_test(const struct tcp_sock *tp, const struct sk_buff *skb,
+ unsigned int cur_mss, int nonagle)
{
/* Nagle rule does not apply to frames, which sit in the middle of the
* write_queue (they have no chances to get new data).
@@ -1409,24 +1426,25 @@ static inline int tcp_nagle_test(const struct tcp_sock *tp, const struct sk_buff
* argument based upon the location of SKB in the send queue.
*/
if (nonagle & TCP_NAGLE_PUSH)
- return 1;
+ return true;
/* Don't use the nagle rule for urgent data (or for the final FIN).
* Nagle can be ignored during F-RTO too (see RFC4138).
*/
if (tcp_urg_mode(tp) || (tp->frto_counter == 2) ||
(TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN))
- return 1;
+ return true;
if (!tcp_nagle_check(tp, skb, cur_mss, nonagle))
- return 1;
+ return true;
- return 0;
+ return false;
}
/* Does at least the first segment of SKB fit into the send window? */
-static inline int tcp_snd_wnd_test(const struct tcp_sock *tp, const struct sk_buff *skb,
- unsigned int cur_mss)
+static bool tcp_snd_wnd_test(const struct tcp_sock *tp,
+ const struct sk_buff *skb,
+ unsigned int cur_mss)
{
u32 end_seq = TCP_SKB_CB(skb)->end_seq;
@@ -1459,7 +1477,7 @@ static unsigned int tcp_snd_test(const struct sock *sk, struct sk_buff *skb,
}
/* Test if sending is allowed right now. */
-int tcp_may_send_now(struct sock *sk)
+bool tcp_may_send_now(struct sock *sk)
{
const struct tcp_sock *tp = tcp_sk(sk);
struct sk_buff *skb = tcp_send_head(sk);
@@ -1529,7 +1547,7 @@ static int tso_fragment(struct sock *sk, struct sk_buff *skb, unsigned int len,
*
* This algorithm is from John Heffner.
*/
-static int tcp_tso_should_defer(struct sock *sk, struct sk_buff *skb)
+static bool tcp_tso_should_defer(struct sock *sk, struct sk_buff *skb)
{
struct tcp_sock *tp = tcp_sk(sk);
const struct inet_connection_sock *icsk = inet_csk(sk);
@@ -1589,11 +1607,11 @@ static int tcp_tso_should_defer(struct sock *sk, struct sk_buff *skb)
/* Ok, it looks like it is advisable to defer. */
tp->tso_deferred = 1 | (jiffies << 1);
- return 1;
+ return true;
send_now:
tp->tso_deferred = 0;
- return 0;
+ return false;
}
/* Create a new MTU probe if we are ready.
@@ -1735,11 +1753,11 @@ static int tcp_mtu_probe(struct sock *sk)
* snd_up-64k-mss .. snd_up cannot be large. However, taking into
* account rare use of URG, this is not a big flaw.
*
- * Returns 1, if no segments are in flight and we have queued segments, but
- * cannot send anything now because of SWS or another problem.
+ * Returns true, if no segments are in flight and we have queued segments,
+ * but cannot send anything now because of SWS or another problem.
*/
-static int tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle,
- int push_one, gfp_t gfp)
+static bool tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle,
+ int push_one, gfp_t gfp)
{
struct tcp_sock *tp = tcp_sk(sk);
struct sk_buff *skb;
@@ -1753,7 +1771,7 @@ static int tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle,
/* Do MTU probing. */
result = tcp_mtu_probe(sk);
if (!result) {
- return 0;
+ return false;
} else if (result > 0) {
sent_pkts = 1;
}
@@ -1812,7 +1830,7 @@ static int tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle,
if (likely(sent_pkts)) {
tcp_cwnd_validate(sk);
- return 0;
+ return false;
}
return !tp->packets_out && tcp_send_head(sk);
}
@@ -2011,22 +2029,22 @@ static void tcp_collapse_retrans(struct sock *sk, struct sk_buff *skb)
}
/* Check if coalescing SKBs is legal. */
-static int tcp_can_collapse(const struct sock *sk, const struct sk_buff *skb)
+static bool tcp_can_collapse(const struct sock *sk, const struct sk_buff *skb)
{
if (tcp_skb_pcount(skb) > 1)
- return 0;
+ return false;
/* TODO: SACK collapsing could be used to remove this condition */
if (skb_shinfo(skb)->nr_frags != 0)
- return 0;
+ return false;
if (skb_cloned(skb))
- return 0;
+ return false;
if (skb == tcp_send_head(sk))
- return 0;
+ return false;
/* Some heurestics for collapsing over SACK'd could be invented */
if (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_ACKED)
- return 0;
+ return false;
- return 1;
+ return true;
}
/* Collapse packets in the retransmit queue to make to create
@@ -2037,7 +2055,7 @@ static void tcp_retrans_try_collapse(struct sock *sk, struct sk_buff *to,
{
struct tcp_sock *tp = tcp_sk(sk);
struct sk_buff *skb = to, *tmp;
- int first = 1;
+ bool first = true;
if (!sysctl_tcp_retrans_collapse)
return;
@@ -2051,7 +2069,7 @@ static void tcp_retrans_try_collapse(struct sock *sk, struct sk_buff *to,
space -= skb->len;
if (first) {
- first = 0;
+ first = false;
continue;
}
@@ -2166,8 +2184,7 @@ int tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb)
#if FASTRETRANS_DEBUG > 0
if (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_RETRANS) {
- if (net_ratelimit())
- printk(KERN_DEBUG "retrans_out leaked.\n");
+ net_dbg_ratelimited("retrans_out leaked\n");
}
#endif
if (!tp->retrans_out)
@@ -2192,18 +2209,18 @@ int tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb)
/* Check if we forward retransmits are possible in the current
* window/congestion state.
*/
-static int tcp_can_forward_retransmit(struct sock *sk)
+static bool tcp_can_forward_retransmit(struct sock *sk)
{
const struct inet_connection_sock *icsk = inet_csk(sk);
const struct tcp_sock *tp = tcp_sk(sk);
/* Forward retransmissions are possible only during Recovery. */
if (icsk->icsk_ca_state != TCP_CA_Recovery)
- return 0;
+ return false;
/* No forward retransmissions in Reno are possible. */
if (tcp_is_reno(tp))
- return 0;
+ return false;
/* Yeah, we have to make difficult choice between forward transmission
* and retransmission... Both ways have their merits...
@@ -2214,9 +2231,9 @@ static int tcp_can_forward_retransmit(struct sock *sk)
*/
if (tcp_may_send_now(sk))
- return 0;
+ return false;
- return 1;
+ return true;
}
/* This gets called after a retransmit timeout, and the initially
@@ -2401,7 +2418,7 @@ int tcp_send_synack(struct sock *sk)
skb = tcp_write_queue_head(sk);
if (skb == NULL || !(TCP_SKB_CB(skb)->tcp_flags & TCPHDR_SYN)) {
- printk(KERN_DEBUG "tcp_send_synack: wrong queue state\n");
+ pr_debug("%s: wrong queue state\n", __func__);
return -EFAULT;
}
if (!(TCP_SKB_CB(skb)->tcp_flags & TCPHDR_ACK)) {
@@ -2561,7 +2578,7 @@ struct sk_buff *tcp_make_synack(struct sock *sk, struct dst_entry *dst,
EXPORT_SYMBOL(tcp_make_synack);
/* Do all connect socket setups that can be done AF independent. */
-static void tcp_connect_init(struct sock *sk)
+void tcp_connect_init(struct sock *sk)
{
const struct dst_entry *dst = __sk_dst_get(sk);
struct tcp_sock *tp = tcp_sk(sk);
@@ -2616,9 +2633,12 @@ static void tcp_connect_init(struct sock *sk)
tp->snd_una = tp->write_seq;
tp->snd_sml = tp->write_seq;
tp->snd_up = tp->write_seq;
- tp->rcv_nxt = 0;
- tp->rcv_wup = 0;
- tp->copied_seq = 0;
+ tp->snd_nxt = tp->write_seq;
+
+ if (likely(!tp->repair))
+ tp->rcv_nxt = 0;
+ tp->rcv_wup = tp->rcv_nxt;
+ tp->copied_seq = tp->rcv_nxt;
inet_csk(sk)->icsk_rto = TCP_TIMEOUT_INIT;
inet_csk(sk)->icsk_retransmits = 0;
@@ -2641,7 +2661,6 @@ int tcp_connect(struct sock *sk)
/* Reserve space for headers. */
skb_reserve(buff, MAX_TCP_HEADER);
- tp->snd_nxt = tp->write_seq;
tcp_init_nondata_skb(buff, tp->write_seq++, TCPHDR_SYN);
TCP_ECN_send_syn(sk, buff);
@@ -2790,6 +2809,15 @@ static int tcp_xmit_probe_skb(struct sock *sk, int urgent)
return tcp_transmit_skb(sk, skb, 0, GFP_ATOMIC);
}
+void tcp_send_window_probe(struct sock *sk)
+{
+ if (sk->sk_state == TCP_ESTABLISHED) {
+ tcp_sk(sk)->snd_wl1 = tcp_sk(sk)->rcv_nxt - 1;
+ tcp_sk(sk)->snd_nxt = tcp_sk(sk)->write_seq;
+ tcp_xmit_probe_skb(sk, 0);
+ }
+}
+
/* Initiate keepalive or window probe from timer. */
int tcp_write_wakeup(struct sock *sk)
{
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