net: wl12xx: care for optional operations
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / net / dccp / timer.c
blob7587870b7040d0d997a54efd4d2c0786a1bb8a7d
1 /*
2 * net/dccp/timer.c
4 * An implementation of the DCCP protocol
5 * Arnaldo Carvalho de Melo <acme@conectiva.com.br>
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version
10 * 2 of the License, or (at your option) any later version.
13 #include <linux/dccp.h>
14 #include <linux/skbuff.h>
16 #include "dccp.h"
18 /* sysctl variables governing numbers of retransmission attempts */
19 int sysctl_dccp_request_retries __read_mostly = TCP_SYN_RETRIES;
20 int sysctl_dccp_retries1 __read_mostly = TCP_RETR1;
21 int sysctl_dccp_retries2 __read_mostly = TCP_RETR2;
23 static void dccp_write_err(struct sock *sk)
25 sk->sk_err = sk->sk_err_soft ? : ETIMEDOUT;
26 sk->sk_error_report(sk);
28 dccp_send_reset(sk, DCCP_RESET_CODE_ABORTED);
29 dccp_done(sk);
30 DCCP_INC_STATS_BH(DCCP_MIB_ABORTONTIMEOUT);
33 /* A write timeout has occurred. Process the after effects. */
34 static int dccp_write_timeout(struct sock *sk)
36 const struct inet_connection_sock *icsk = inet_csk(sk);
37 int retry_until;
39 if (sk->sk_state == DCCP_REQUESTING || sk->sk_state == DCCP_PARTOPEN) {
40 if (icsk->icsk_retransmits != 0)
41 dst_negative_advice(sk);
42 retry_until = icsk->icsk_syn_retries ?
43 : sysctl_dccp_request_retries;
44 } else {
45 if (icsk->icsk_retransmits >= sysctl_dccp_retries1) {
46 /* NOTE. draft-ietf-tcpimpl-pmtud-01.txt requires pmtu
47 black hole detection. :-(
49 It is place to make it. It is not made. I do not want
50 to make it. It is disguisting. It does not work in any
51 case. Let me to cite the same draft, which requires for
52 us to implement this:
54 "The one security concern raised by this memo is that ICMP black holes
55 are often caused by over-zealous security administrators who block
56 all ICMP messages. It is vitally important that those who design and
57 deploy security systems understand the impact of strict filtering on
58 upper-layer protocols. The safest web site in the world is worthless
59 if most TCP implementations cannot transfer data from it. It would
60 be far nicer to have all of the black holes fixed rather than fixing
61 all of the TCP implementations."
63 Golden words :-).
66 dst_negative_advice(sk);
69 retry_until = sysctl_dccp_retries2;
71 * FIXME: see tcp_write_timout and tcp_out_of_resources
75 if (icsk->icsk_retransmits >= retry_until) {
76 /* Has it gone just too far? */
77 dccp_write_err(sk);
78 return 1;
80 return 0;
84 * The DCCP retransmit timer.
86 static void dccp_retransmit_timer(struct sock *sk)
88 struct inet_connection_sock *icsk = inet_csk(sk);
91 * More than than 4MSL (8 minutes) has passed, a RESET(aborted) was
92 * sent, no need to retransmit, this sock is dead.
94 if (dccp_write_timeout(sk))
95 return;
98 * We want to know the number of packets retransmitted, not the
99 * total number of retransmissions of clones of original packets.
101 if (icsk->icsk_retransmits == 0)
102 DCCP_INC_STATS_BH(DCCP_MIB_TIMEOUTS);
104 if (dccp_retransmit_skb(sk) != 0) {
106 * Retransmission failed because of local congestion,
107 * do not backoff.
109 if (--icsk->icsk_retransmits == 0)
110 icsk->icsk_retransmits = 1;
111 inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
112 min(icsk->icsk_rto,
113 TCP_RESOURCE_PROBE_INTERVAL),
114 DCCP_RTO_MAX);
115 return;
118 icsk->icsk_backoff++;
120 icsk->icsk_rto = min(icsk->icsk_rto << 1, DCCP_RTO_MAX);
121 inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, icsk->icsk_rto,
122 DCCP_RTO_MAX);
123 if (icsk->icsk_retransmits > sysctl_dccp_retries1)
124 __sk_dst_reset(sk);
127 static void dccp_write_timer(unsigned long data)
129 struct sock *sk = (struct sock *)data;
130 struct inet_connection_sock *icsk = inet_csk(sk);
131 int event = 0;
133 bh_lock_sock(sk);
134 if (sock_owned_by_user(sk)) {
135 /* Try again later */
136 sk_reset_timer(sk, &icsk->icsk_retransmit_timer,
137 jiffies + (HZ / 20));
138 goto out;
141 if (sk->sk_state == DCCP_CLOSED || !icsk->icsk_pending)
142 goto out;
144 if (time_after(icsk->icsk_timeout, jiffies)) {
145 sk_reset_timer(sk, &icsk->icsk_retransmit_timer,
146 icsk->icsk_timeout);
147 goto out;
150 event = icsk->icsk_pending;
151 icsk->icsk_pending = 0;
153 switch (event) {
154 case ICSK_TIME_RETRANS:
155 dccp_retransmit_timer(sk);
156 break;
158 out:
159 bh_unlock_sock(sk);
160 sock_put(sk);
164 * Timer for listening sockets
166 static void dccp_response_timer(struct sock *sk)
168 inet_csk_reqsk_queue_prune(sk, TCP_SYNQ_INTERVAL, DCCP_TIMEOUT_INIT,
169 DCCP_RTO_MAX);
172 static void dccp_keepalive_timer(unsigned long data)
174 struct sock *sk = (struct sock *)data;
176 /* Only process if socket is not in use. */
177 bh_lock_sock(sk);
178 if (sock_owned_by_user(sk)) {
179 /* Try again later. */
180 inet_csk_reset_keepalive_timer(sk, HZ / 20);
181 goto out;
184 if (sk->sk_state == DCCP_LISTEN) {
185 dccp_response_timer(sk);
186 goto out;
188 out:
189 bh_unlock_sock(sk);
190 sock_put(sk);
193 /* This is the same as tcp_delack_timer, sans prequeue & mem_reclaim stuff */
194 static void dccp_delack_timer(unsigned long data)
196 struct sock *sk = (struct sock *)data;
197 struct inet_connection_sock *icsk = inet_csk(sk);
199 bh_lock_sock(sk);
200 if (sock_owned_by_user(sk)) {
201 /* Try again later. */
202 icsk->icsk_ack.blocked = 1;
203 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_DELAYEDACKLOCKED);
204 sk_reset_timer(sk, &icsk->icsk_delack_timer,
205 jiffies + TCP_DELACK_MIN);
206 goto out;
209 if (sk->sk_state == DCCP_CLOSED ||
210 !(icsk->icsk_ack.pending & ICSK_ACK_TIMER))
211 goto out;
212 if (time_after(icsk->icsk_ack.timeout, jiffies)) {
213 sk_reset_timer(sk, &icsk->icsk_delack_timer,
214 icsk->icsk_ack.timeout);
215 goto out;
218 icsk->icsk_ack.pending &= ~ICSK_ACK_TIMER;
220 if (inet_csk_ack_scheduled(sk)) {
221 if (!icsk->icsk_ack.pingpong) {
222 /* Delayed ACK missed: inflate ATO. */
223 icsk->icsk_ack.ato = min(icsk->icsk_ack.ato << 1,
224 icsk->icsk_rto);
225 } else {
226 /* Delayed ACK missed: leave pingpong mode and
227 * deflate ATO.
229 icsk->icsk_ack.pingpong = 0;
230 icsk->icsk_ack.ato = TCP_ATO_MIN;
232 dccp_send_ack(sk);
233 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_DELAYEDACKS);
235 out:
236 bh_unlock_sock(sk);
237 sock_put(sk);
241 * dccp_write_xmitlet - Workhorse for CCID packet dequeueing interface
242 * See the comments above %ccid_dequeueing_decision for supported modes.
244 static void dccp_write_xmitlet(unsigned long data)
246 struct sock *sk = (struct sock *)data;
248 bh_lock_sock(sk);
249 if (sock_owned_by_user(sk))
250 sk_reset_timer(sk, &dccp_sk(sk)->dccps_xmit_timer, jiffies + 1);
251 else
252 dccp_write_xmit(sk);
253 bh_unlock_sock(sk);
256 static void dccp_write_xmit_timer(unsigned long data)
258 dccp_write_xmitlet(data);
259 sock_put((struct sock *)data);
262 void dccp_init_xmit_timers(struct sock *sk)
264 struct dccp_sock *dp = dccp_sk(sk);
266 tasklet_init(&dp->dccps_xmitlet, dccp_write_xmitlet, (unsigned long)sk);
267 setup_timer(&dp->dccps_xmit_timer, dccp_write_xmit_timer,
268 (unsigned long)sk);
269 inet_csk_init_xmit_timers(sk, &dccp_write_timer, &dccp_delack_timer,
270 &dccp_keepalive_timer);
273 static ktime_t dccp_timestamp_seed;
275 * dccp_timestamp - 10s of microseconds time source
276 * Returns the number of 10s of microseconds since loading DCCP. This is native
277 * DCCP time difference format (RFC 4340, sec. 13).
278 * Please note: This will wrap around about circa every 11.9 hours.
280 u32 dccp_timestamp(void)
282 s64 delta = ktime_us_delta(ktime_get_real(), dccp_timestamp_seed);
284 do_div(delta, 10);
285 return delta;
287 EXPORT_SYMBOL_GPL(dccp_timestamp);
289 void __init dccp_timestamping_init(void)
291 dccp_timestamp_seed = ktime_get_real();