Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c
new file mode 100644
index 0000000..85b279f
--- /dev/null
+++ b/net/ipv4/tcp_timer.c
@@ -0,0 +1,656 @@
+/*
+ * INET An implementation of the TCP/IP protocol suite for the LINUX
+ * operating system. INET is implemented using the BSD Socket
+ * interface as the means of communication with the user level.
+ *
+ * Implementation of the Transmission Control Protocol(TCP).
+ *
+ * Version: $Id: tcp_timer.c,v 1.88 2002/02/01 22:01:04 davem Exp $
+ *
+ * Authors: Ross Biro, <bir7@leland.Stanford.Edu>
+ * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
+ * Mark Evans, <evansmp@uhura.aston.ac.uk>
+ * Corey Minyard <wf-rch!minyard@relay.EU.net>
+ * Florian La Roche, <flla@stud.uni-sb.de>
+ * Charles Hedrick, <hedrick@klinzhai.rutgers.edu>
+ * Linus Torvalds, <torvalds@cs.helsinki.fi>
+ * Alan Cox, <gw4pts@gw4pts.ampr.org>
+ * Matthew Dillon, <dillon@apollo.west.oic.com>
+ * Arnt Gulbrandsen, <agulbra@nvg.unit.no>
+ * Jorge Cwik, <jorge@laser.satlink.net>
+ */
+
+#include <linux/module.h>
+#include <net/tcp.h>
+
+int sysctl_tcp_syn_retries = TCP_SYN_RETRIES;
+int sysctl_tcp_synack_retries = TCP_SYNACK_RETRIES;
+int sysctl_tcp_keepalive_time = TCP_KEEPALIVE_TIME;
+int sysctl_tcp_keepalive_probes = TCP_KEEPALIVE_PROBES;
+int sysctl_tcp_keepalive_intvl = TCP_KEEPALIVE_INTVL;
+int sysctl_tcp_retries1 = TCP_RETR1;
+int sysctl_tcp_retries2 = TCP_RETR2;
+int sysctl_tcp_orphan_retries;
+
+static void tcp_write_timer(unsigned long);
+static void tcp_delack_timer(unsigned long);
+static void tcp_keepalive_timer (unsigned long data);
+
+#ifdef TCP_DEBUG
+const char tcp_timer_bug_msg[] = KERN_DEBUG "tcpbug: unknown timer value\n";
+EXPORT_SYMBOL(tcp_timer_bug_msg);
+#endif
+
+/*
+ * Using different timers for retransmit, delayed acks and probes
+ * We may wish use just one timer maintaining a list of expire jiffies
+ * to optimize.
+ */
+
+void tcp_init_xmit_timers(struct sock *sk)
+{
+ struct tcp_sock *tp = tcp_sk(sk);
+
+ init_timer(&tp->retransmit_timer);
+ tp->retransmit_timer.function=&tcp_write_timer;
+ tp->retransmit_timer.data = (unsigned long) sk;
+ tp->pending = 0;
+
+ init_timer(&tp->delack_timer);
+ tp->delack_timer.function=&tcp_delack_timer;
+ tp->delack_timer.data = (unsigned long) sk;
+ tp->ack.pending = 0;
+
+ init_timer(&sk->sk_timer);
+ sk->sk_timer.function = &tcp_keepalive_timer;
+ sk->sk_timer.data = (unsigned long)sk;
+}
+
+void tcp_clear_xmit_timers(struct sock *sk)
+{
+ struct tcp_sock *tp = tcp_sk(sk);
+
+ tp->pending = 0;
+ sk_stop_timer(sk, &tp->retransmit_timer);
+
+ tp->ack.pending = 0;
+ tp->ack.blocked = 0;
+ sk_stop_timer(sk, &tp->delack_timer);
+
+ sk_stop_timer(sk, &sk->sk_timer);
+}
+
+static void tcp_write_err(struct sock *sk)
+{
+ sk->sk_err = sk->sk_err_soft ? : ETIMEDOUT;
+ sk->sk_error_report(sk);
+
+ tcp_done(sk);
+ NET_INC_STATS_BH(LINUX_MIB_TCPABORTONTIMEOUT);
+}
+
+/* Do not allow orphaned sockets to eat all our resources.
+ * This is direct violation of TCP specs, but it is required
+ * to prevent DoS attacks. It is called when a retransmission timeout
+ * or zero probe timeout occurs on orphaned socket.
+ *
+ * Criterium is still not confirmed experimentally and may change.
+ * We kill the socket, if:
+ * 1. If number of orphaned sockets exceeds an administratively configured
+ * limit.
+ * 2. If we have strong memory pressure.
+ */
+static int tcp_out_of_resources(struct sock *sk, int do_reset)
+{
+ struct tcp_sock *tp = tcp_sk(sk);
+ int orphans = atomic_read(&tcp_orphan_count);
+
+ /* If peer does not open window for long time, or did not transmit
+ * anything for long time, penalize it. */
+ if ((s32)(tcp_time_stamp - tp->lsndtime) > 2*TCP_RTO_MAX || !do_reset)
+ orphans <<= 1;
+
+ /* If some dubious ICMP arrived, penalize even more. */
+ if (sk->sk_err_soft)
+ orphans <<= 1;
+
+ if (orphans >= sysctl_tcp_max_orphans ||
+ (sk->sk_wmem_queued > SOCK_MIN_SNDBUF &&
+ atomic_read(&tcp_memory_allocated) > sysctl_tcp_mem[2])) {
+ if (net_ratelimit())
+ printk(KERN_INFO "Out of socket memory\n");
+
+ /* Catch exceptional cases, when connection requires reset.
+ * 1. Last segment was sent recently. */
+ if ((s32)(tcp_time_stamp - tp->lsndtime) <= TCP_TIMEWAIT_LEN ||
+ /* 2. Window is closed. */
+ (!tp->snd_wnd && !tp->packets_out))
+ do_reset = 1;
+ if (do_reset)
+ tcp_send_active_reset(sk, GFP_ATOMIC);
+ tcp_done(sk);
+ NET_INC_STATS_BH(LINUX_MIB_TCPABORTONMEMORY);
+ return 1;
+ }
+ return 0;
+}
+
+/* Calculate maximal number or retries on an orphaned socket. */
+static int tcp_orphan_retries(struct sock *sk, int alive)
+{
+ int retries = sysctl_tcp_orphan_retries; /* May be zero. */
+
+ /* We know from an ICMP that something is wrong. */
+ if (sk->sk_err_soft && !alive)
+ retries = 0;
+
+ /* However, if socket sent something recently, select some safe
+ * number of retries. 8 corresponds to >100 seconds with minimal
+ * RTO of 200msec. */
+ if (retries == 0 && alive)
+ retries = 8;
+ return retries;
+}
+
+/* A write timeout has occurred. Process the after effects. */
+static int tcp_write_timeout(struct sock *sk)
+{
+ struct tcp_sock *tp = tcp_sk(sk);
+ int retry_until;
+
+ if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
+ if (tp->retransmits)
+ dst_negative_advice(&sk->sk_dst_cache);
+ retry_until = tp->syn_retries ? : sysctl_tcp_syn_retries;
+ } else {
+ if (tp->retransmits >= sysctl_tcp_retries1) {
+ /* NOTE. draft-ietf-tcpimpl-pmtud-01.txt requires pmtu black
+ hole detection. :-(
+
+ It is place to make it. It is not made. I do not want
+ to make it. It is disguisting. It does not work in any
+ case. Let me to cite the same draft, which requires for
+ us to implement this:
+
+ "The one security concern raised by this memo is that ICMP black holes
+ are often caused by over-zealous security administrators who block
+ all ICMP messages. It is vitally important that those who design and
+ deploy security systems understand the impact of strict filtering on
+ upper-layer protocols. The safest web site in the world is worthless
+ if most TCP implementations cannot transfer data from it. It would
+ be far nicer to have all of the black holes fixed rather than fixing
+ all of the TCP implementations."
+
+ Golden words :-).
+ */
+
+ dst_negative_advice(&sk->sk_dst_cache);
+ }
+
+ retry_until = sysctl_tcp_retries2;
+ if (sock_flag(sk, SOCK_DEAD)) {
+ int alive = (tp->rto < TCP_RTO_MAX);
+
+ retry_until = tcp_orphan_retries(sk, alive);
+
+ if (tcp_out_of_resources(sk, alive || tp->retransmits < retry_until))
+ return 1;
+ }
+ }
+
+ if (tp->retransmits >= retry_until) {
+ /* Has it gone just too far? */
+ tcp_write_err(sk);
+ return 1;
+ }
+ return 0;
+}
+
+static void tcp_delack_timer(unsigned long data)
+{
+ struct sock *sk = (struct sock*)data;
+ struct tcp_sock *tp = tcp_sk(sk);
+
+ bh_lock_sock(sk);
+ if (sock_owned_by_user(sk)) {
+ /* Try again later. */
+ tp->ack.blocked = 1;
+ NET_INC_STATS_BH(LINUX_MIB_DELAYEDACKLOCKED);
+ sk_reset_timer(sk, &tp->delack_timer, jiffies + TCP_DELACK_MIN);
+ goto out_unlock;
+ }
+
+ sk_stream_mem_reclaim(sk);
+
+ if (sk->sk_state == TCP_CLOSE || !(tp->ack.pending & TCP_ACK_TIMER))
+ goto out;
+
+ if (time_after(tp->ack.timeout, jiffies)) {
+ sk_reset_timer(sk, &tp->delack_timer, tp->ack.timeout);
+ goto out;
+ }
+ tp->ack.pending &= ~TCP_ACK_TIMER;
+
+ if (skb_queue_len(&tp->ucopy.prequeue)) {
+ struct sk_buff *skb;
+
+ NET_ADD_STATS_BH(LINUX_MIB_TCPSCHEDULERFAILED,
+ skb_queue_len(&tp->ucopy.prequeue));
+
+ while ((skb = __skb_dequeue(&tp->ucopy.prequeue)) != NULL)
+ sk->sk_backlog_rcv(sk, skb);
+
+ tp->ucopy.memory = 0;
+ }
+
+ if (tcp_ack_scheduled(tp)) {
+ if (!tp->ack.pingpong) {
+ /* Delayed ACK missed: inflate ATO. */
+ tp->ack.ato = min(tp->ack.ato << 1, tp->rto);
+ } else {
+ /* Delayed ACK missed: leave pingpong mode and
+ * deflate ATO.
+ */
+ tp->ack.pingpong = 0;
+ tp->ack.ato = TCP_ATO_MIN;
+ }
+ tcp_send_ack(sk);
+ NET_INC_STATS_BH(LINUX_MIB_DELAYEDACKS);
+ }
+ TCP_CHECK_TIMER(sk);
+
+out:
+ if (tcp_memory_pressure)
+ sk_stream_mem_reclaim(sk);
+out_unlock:
+ bh_unlock_sock(sk);
+ sock_put(sk);
+}
+
+static void tcp_probe_timer(struct sock *sk)
+{
+ struct tcp_sock *tp = tcp_sk(sk);
+ int max_probes;
+
+ if (tp->packets_out || !sk->sk_send_head) {
+ tp->probes_out = 0;
+ return;
+ }
+
+ /* *WARNING* RFC 1122 forbids this
+ *
+ * It doesn't AFAIK, because we kill the retransmit timer -AK
+ *
+ * FIXME: We ought not to do it, Solaris 2.5 actually has fixing
+ * this behaviour in Solaris down as a bug fix. [AC]
+ *
+ * Let me to explain. probes_out is zeroed by incoming ACKs
+ * even if they advertise zero window. Hence, connection is killed only
+ * if we received no ACKs for normal connection timeout. It is not killed
+ * only because window stays zero for some time, window may be zero
+ * until armageddon and even later. We are in full accordance
+ * with RFCs, only probe timer combines both retransmission timeout
+ * and probe timeout in one bottle. --ANK
+ */
+ max_probes = sysctl_tcp_retries2;
+
+ if (sock_flag(sk, SOCK_DEAD)) {
+ int alive = ((tp->rto<<tp->backoff) < TCP_RTO_MAX);
+
+ max_probes = tcp_orphan_retries(sk, alive);
+
+ if (tcp_out_of_resources(sk, alive || tp->probes_out <= max_probes))
+ return;
+ }
+
+ if (tp->probes_out > max_probes) {
+ tcp_write_err(sk);
+ } else {
+ /* Only send another probe if we didn't close things up. */
+ tcp_send_probe0(sk);
+ }
+}
+
+/*
+ * The TCP retransmit timer.
+ */
+
+static void tcp_retransmit_timer(struct sock *sk)
+{
+ struct tcp_sock *tp = tcp_sk(sk);
+
+ if (!tp->packets_out)
+ goto out;
+
+ BUG_TRAP(!skb_queue_empty(&sk->sk_write_queue));
+
+ if (!tp->snd_wnd && !sock_flag(sk, SOCK_DEAD) &&
+ !((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV))) {
+ /* Receiver dastardly shrinks window. Our retransmits
+ * become zero probes, but we should not timeout this
+ * connection. If the socket is an orphan, time it out,
+ * we cannot allow such beasts to hang infinitely.
+ */
+#ifdef TCP_DEBUG
+ if (net_ratelimit()) {
+ struct inet_sock *inet = inet_sk(sk);
+ printk(KERN_DEBUG "TCP: Treason uncloaked! Peer %u.%u.%u.%u:%u/%u shrinks window %u:%u. Repaired.\n",
+ NIPQUAD(inet->daddr), htons(inet->dport),
+ inet->num, tp->snd_una, tp->snd_nxt);
+ }
+#endif
+ if (tcp_time_stamp - tp->rcv_tstamp > TCP_RTO_MAX) {
+ tcp_write_err(sk);
+ goto out;
+ }
+ tcp_enter_loss(sk, 0);
+ tcp_retransmit_skb(sk, skb_peek(&sk->sk_write_queue));
+ __sk_dst_reset(sk);
+ goto out_reset_timer;
+ }
+
+ if (tcp_write_timeout(sk))
+ goto out;
+
+ if (tp->retransmits == 0) {
+ if (tp->ca_state == TCP_CA_Disorder || tp->ca_state == TCP_CA_Recovery) {
+ if (tp->rx_opt.sack_ok) {
+ if (tp->ca_state == TCP_CA_Recovery)
+ NET_INC_STATS_BH(LINUX_MIB_TCPSACKRECOVERYFAIL);
+ else
+ NET_INC_STATS_BH(LINUX_MIB_TCPSACKFAILURES);
+ } else {
+ if (tp->ca_state == TCP_CA_Recovery)
+ NET_INC_STATS_BH(LINUX_MIB_TCPRENORECOVERYFAIL);
+ else
+ NET_INC_STATS_BH(LINUX_MIB_TCPRENOFAILURES);
+ }
+ } else if (tp->ca_state == TCP_CA_Loss) {
+ NET_INC_STATS_BH(LINUX_MIB_TCPLOSSFAILURES);
+ } else {
+ NET_INC_STATS_BH(LINUX_MIB_TCPTIMEOUTS);
+ }
+ }
+
+ if (tcp_use_frto(sk)) {
+ tcp_enter_frto(sk);
+ } else {
+ tcp_enter_loss(sk, 0);
+ }
+
+ if (tcp_retransmit_skb(sk, skb_peek(&sk->sk_write_queue)) > 0) {
+ /* Retransmission failed because of local congestion,
+ * do not backoff.
+ */
+ if (!tp->retransmits)
+ tp->retransmits=1;
+ tcp_reset_xmit_timer(sk, TCP_TIME_RETRANS,
+ min(tp->rto, TCP_RESOURCE_PROBE_INTERVAL));
+ goto out;
+ }
+
+ /* Increase the timeout each time we retransmit. Note that
+ * we do not increase the rtt estimate. rto is initialized
+ * from rtt, but increases here. Jacobson (SIGCOMM 88) suggests
+ * that doubling rto each time is the least we can get away with.
+ * In KA9Q, Karn uses this for the first few times, and then
+ * goes to quadratic. netBSD doubles, but only goes up to *64,
+ * and clamps at 1 to 64 sec afterwards. Note that 120 sec is
+ * defined in the protocol as the maximum possible RTT. I guess
+ * we'll have to use something other than TCP to talk to the
+ * University of Mars.
+ *
+ * PAWS allows us longer timeouts and large windows, so once
+ * implemented ftp to mars will work nicely. We will have to fix
+ * the 120 second clamps though!
+ */
+ tp->backoff++;
+ tp->retransmits++;
+
+out_reset_timer:
+ tp->rto = min(tp->rto << 1, TCP_RTO_MAX);
+ tcp_reset_xmit_timer(sk, TCP_TIME_RETRANS, tp->rto);
+ if (tp->retransmits > sysctl_tcp_retries1)
+ __sk_dst_reset(sk);
+
+out:;
+}
+
+static void tcp_write_timer(unsigned long data)
+{
+ struct sock *sk = (struct sock*)data;
+ struct tcp_sock *tp = tcp_sk(sk);
+ int event;
+
+ bh_lock_sock(sk);
+ if (sock_owned_by_user(sk)) {
+ /* Try again later */
+ sk_reset_timer(sk, &tp->retransmit_timer, jiffies + (HZ / 20));
+ goto out_unlock;
+ }
+
+ if (sk->sk_state == TCP_CLOSE || !tp->pending)
+ goto out;
+
+ if (time_after(tp->timeout, jiffies)) {
+ sk_reset_timer(sk, &tp->retransmit_timer, tp->timeout);
+ goto out;
+ }
+
+ event = tp->pending;
+ tp->pending = 0;
+
+ switch (event) {
+ case TCP_TIME_RETRANS:
+ tcp_retransmit_timer(sk);
+ break;
+ case TCP_TIME_PROBE0:
+ tcp_probe_timer(sk);
+ break;
+ }
+ TCP_CHECK_TIMER(sk);
+
+out:
+ sk_stream_mem_reclaim(sk);
+out_unlock:
+ bh_unlock_sock(sk);
+ sock_put(sk);
+}
+
+/*
+ * Timer for listening sockets
+ */
+
+static void tcp_synack_timer(struct sock *sk)
+{
+ struct tcp_sock *tp = tcp_sk(sk);
+ struct tcp_listen_opt *lopt = tp->listen_opt;
+ int max_retries = tp->syn_retries ? : sysctl_tcp_synack_retries;
+ int thresh = max_retries;
+ unsigned long now = jiffies;
+ struct open_request **reqp, *req;
+ int i, budget;
+
+ if (lopt == NULL || lopt->qlen == 0)
+ return;
+
+ /* Normally all the openreqs are young and become mature
+ * (i.e. converted to established socket) for first timeout.
+ * If synack was not acknowledged for 3 seconds, it means
+ * one of the following things: synack was lost, ack was lost,
+ * rtt is high or nobody planned to ack (i.e. synflood).
+ * When server is a bit loaded, queue is populated with old
+ * open requests, reducing effective size of queue.
+ * When server is well loaded, queue size reduces to zero
+ * after several minutes of work. It is not synflood,
+ * it is normal operation. The solution is pruning
+ * too old entries overriding normal timeout, when
+ * situation becomes dangerous.
+ *
+ * Essentially, we reserve half of room for young
+ * embrions; and abort old ones without pity, if old
+ * ones are about to clog our table.
+ */
+ if (lopt->qlen>>(lopt->max_qlen_log-1)) {
+ int young = (lopt->qlen_young<<1);
+
+ while (thresh > 2) {
+ if (lopt->qlen < young)
+ break;
+ thresh--;
+ young <<= 1;
+ }
+ }
+
+ if (tp->defer_accept)
+ max_retries = tp->defer_accept;
+
+ budget = 2*(TCP_SYNQ_HSIZE/(TCP_TIMEOUT_INIT/TCP_SYNQ_INTERVAL));
+ i = lopt->clock_hand;
+
+ do {
+ reqp=&lopt->syn_table[i];
+ while ((req = *reqp) != NULL) {
+ if (time_after_eq(now, req->expires)) {
+ if ((req->retrans < thresh ||
+ (req->acked && req->retrans < max_retries))
+ && !req->class->rtx_syn_ack(sk, req, NULL)) {
+ unsigned long timeo;
+
+ if (req->retrans++ == 0)
+ lopt->qlen_young--;
+ timeo = min((TCP_TIMEOUT_INIT << req->retrans),
+ TCP_RTO_MAX);
+ req->expires = now + timeo;
+ reqp = &req->dl_next;
+ continue;
+ }
+
+ /* Drop this request */
+ write_lock(&tp->syn_wait_lock);
+ *reqp = req->dl_next;
+ write_unlock(&tp->syn_wait_lock);
+ lopt->qlen--;
+ if (req->retrans == 0)
+ lopt->qlen_young--;
+ tcp_openreq_free(req);
+ continue;
+ }
+ reqp = &req->dl_next;
+ }
+
+ i = (i+1)&(TCP_SYNQ_HSIZE-1);
+
+ } while (--budget > 0);
+
+ lopt->clock_hand = i;
+
+ if (lopt->qlen)
+ tcp_reset_keepalive_timer(sk, TCP_SYNQ_INTERVAL);
+}
+
+void tcp_delete_keepalive_timer (struct sock *sk)
+{
+ sk_stop_timer(sk, &sk->sk_timer);
+}
+
+void tcp_reset_keepalive_timer (struct sock *sk, unsigned long len)
+{
+ sk_reset_timer(sk, &sk->sk_timer, jiffies + len);
+}
+
+void tcp_set_keepalive(struct sock *sk, int val)
+{
+ if ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))
+ return;
+
+ if (val && !sock_flag(sk, SOCK_KEEPOPEN))
+ tcp_reset_keepalive_timer(sk, keepalive_time_when(tcp_sk(sk)));
+ else if (!val)
+ tcp_delete_keepalive_timer(sk);
+}
+
+
+static void tcp_keepalive_timer (unsigned long data)
+{
+ struct sock *sk = (struct sock *) data;
+ struct tcp_sock *tp = tcp_sk(sk);
+ __u32 elapsed;
+
+ /* Only process if socket is not in use. */
+ bh_lock_sock(sk);
+ if (sock_owned_by_user(sk)) {
+ /* Try again later. */
+ tcp_reset_keepalive_timer (sk, HZ/20);
+ goto out;
+ }
+
+ if (sk->sk_state == TCP_LISTEN) {
+ tcp_synack_timer(sk);
+ goto out;
+ }
+
+ if (sk->sk_state == TCP_FIN_WAIT2 && sock_flag(sk, SOCK_DEAD)) {
+ if (tp->linger2 >= 0) {
+ int tmo = tcp_fin_time(tp) - TCP_TIMEWAIT_LEN;
+
+ if (tmo > 0) {
+ tcp_time_wait(sk, TCP_FIN_WAIT2, tmo);
+ goto out;
+ }
+ }
+ tcp_send_active_reset(sk, GFP_ATOMIC);
+ goto death;
+ }
+
+ if (!sock_flag(sk, SOCK_KEEPOPEN) || sk->sk_state == TCP_CLOSE)
+ goto out;
+
+ elapsed = keepalive_time_when(tp);
+
+ /* It is alive without keepalive 8) */
+ if (tp->packets_out || sk->sk_send_head)
+ goto resched;
+
+ elapsed = tcp_time_stamp - tp->rcv_tstamp;
+
+ if (elapsed >= keepalive_time_when(tp)) {
+ if ((!tp->keepalive_probes && tp->probes_out >= sysctl_tcp_keepalive_probes) ||
+ (tp->keepalive_probes && tp->probes_out >= tp->keepalive_probes)) {
+ tcp_send_active_reset(sk, GFP_ATOMIC);
+ tcp_write_err(sk);
+ goto out;
+ }
+ if (tcp_write_wakeup(sk) <= 0) {
+ tp->probes_out++;
+ elapsed = keepalive_intvl_when(tp);
+ } else {
+ /* If keepalive was lost due to local congestion,
+ * try harder.
+ */
+ elapsed = TCP_RESOURCE_PROBE_INTERVAL;
+ }
+ } else {
+ /* It is tp->rcv_tstamp + keepalive_time_when(tp) */
+ elapsed = keepalive_time_when(tp) - elapsed;
+ }
+
+ TCP_CHECK_TIMER(sk);
+ sk_stream_mem_reclaim(sk);
+
+resched:
+ tcp_reset_keepalive_timer (sk, elapsed);
+ goto out;
+
+death:
+ tcp_done(sk);
+
+out:
+ bh_unlock_sock(sk);
+ sock_put(sk);
+}
+
+EXPORT_SYMBOL(tcp_clear_xmit_timers);
+EXPORT_SYMBOL(tcp_delete_keepalive_timer);
+EXPORT_SYMBOL(tcp_init_xmit_timers);
+EXPORT_SYMBOL(tcp_reset_keepalive_timer);