Commit | Line | Data |
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7c657876 ACM |
1 | /* |
2 | * net/dccp/output.c | |
3 | * | |
4 | * An implementation of the DCCP protocol | |
5 | * Arnaldo Carvalho de Melo <acme@conectiva.com.br> | |
6 | * | |
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. | |
11 | */ | |
12 | ||
13 | #include <linux/config.h> | |
14 | #include <linux/dccp.h> | |
48918a4d | 15 | #include <linux/kernel.h> |
7c657876 ACM |
16 | #include <linux/skbuff.h> |
17 | ||
14c85021 | 18 | #include <net/inet_sock.h> |
7c657876 ACM |
19 | #include <net/sock.h> |
20 | ||
ae31c339 | 21 | #include "ackvec.h" |
7c657876 ACM |
22 | #include "ccid.h" |
23 | #include "dccp.h" | |
24 | ||
25 | static inline void dccp_event_ack_sent(struct sock *sk) | |
26 | { | |
27 | inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK); | |
28 | } | |
29 | ||
c25a18ba | 30 | static void dccp_skb_entail(struct sock *sk, struct sk_buff *skb) |
48918a4d HX |
31 | { |
32 | skb_set_owner_w(skb, sk); | |
33 | WARN_ON(sk->sk_send_head); | |
34 | sk->sk_send_head = skb; | |
35 | } | |
36 | ||
7c657876 ACM |
37 | /* |
38 | * All SKB's seen here are completely headerless. It is our | |
39 | * job to build the DCCP header, and pass the packet down to | |
40 | * IP so it can do the same plus pass the packet off to the | |
41 | * device. | |
42 | */ | |
48918a4d | 43 | static int dccp_transmit_skb(struct sock *sk, struct sk_buff *skb) |
7c657876 ACM |
44 | { |
45 | if (likely(skb != NULL)) { | |
46 | const struct inet_sock *inet = inet_sk(sk); | |
57cca05a | 47 | const struct inet_connection_sock *icsk = inet_csk(sk); |
7c657876 ACM |
48 | struct dccp_sock *dp = dccp_sk(sk); |
49 | struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb); | |
50 | struct dccp_hdr *dh; | |
51 | /* XXX For now we're using only 48 bits sequence numbers */ | |
118b2c95 | 52 | const u32 dccp_header_size = sizeof(*dh) + |
7c657876 | 53 | sizeof(struct dccp_hdr_ext) + |
7690af3f | 54 | dccp_packet_hdr_len(dcb->dccpd_type); |
7c657876 ACM |
55 | int err, set_ack = 1; |
56 | u64 ackno = dp->dccps_gsr; | |
57 | ||
7c657876 ACM |
58 | dccp_inc_seqno(&dp->dccps_gss); |
59 | ||
7c657876 ACM |
60 | switch (dcb->dccpd_type) { |
61 | case DCCP_PKT_DATA: | |
62 | set_ack = 0; | |
edc9e819 HX |
63 | /* fall through */ |
64 | case DCCP_PKT_DATAACK: | |
7c657876 | 65 | break; |
edc9e819 | 66 | |
afe00251 AB |
67 | case DCCP_PKT_REQUEST: |
68 | set_ack = 0; | |
69 | /* fall through */ | |
70 | ||
7c657876 ACM |
71 | case DCCP_PKT_SYNC: |
72 | case DCCP_PKT_SYNCACK: | |
73 | ackno = dcb->dccpd_seq; | |
edc9e819 HX |
74 | /* fall through */ |
75 | default: | |
76 | /* | |
77 | * Only data packets should come through with skb->sk | |
78 | * set. | |
79 | */ | |
80 | WARN_ON(skb->sk); | |
81 | skb_set_owner_w(skb, sk); | |
7c657876 ACM |
82 | break; |
83 | } | |
24117727 ACM |
84 | |
85 | dcb->dccpd_seq = dp->dccps_gss; | |
86 | dccp_insert_options(sk, skb); | |
7c657876 ACM |
87 | |
88 | skb->h.raw = skb_push(skb, dccp_header_size); | |
89 | dh = dccp_hdr(skb); | |
fda0fd6c | 90 | |
7c657876 ACM |
91 | /* Build DCCP header and checksum it. */ |
92 | memset(dh, 0, dccp_header_size); | |
93 | dh->dccph_type = dcb->dccpd_type; | |
94 | dh->dccph_sport = inet->sport; | |
95 | dh->dccph_dport = inet->dport; | |
96 | dh->dccph_doff = (dccp_header_size + dcb->dccpd_opt_len) / 4; | |
97 | dh->dccph_ccval = dcb->dccpd_ccval; | |
98 | /* XXX For now we're using only 48 bits sequence numbers */ | |
99 | dh->dccph_x = 1; | |
100 | ||
101 | dp->dccps_awh = dp->dccps_gss; | |
102 | dccp_hdr_set_seq(dh, dp->dccps_gss); | |
103 | if (set_ack) | |
104 | dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), ackno); | |
105 | ||
106 | switch (dcb->dccpd_type) { | |
107 | case DCCP_PKT_REQUEST: | |
7690af3f | 108 | dccp_hdr_request(skb)->dccph_req_service = |
67e6b629 | 109 | dp->dccps_service; |
7c657876 ACM |
110 | break; |
111 | case DCCP_PKT_RESET: | |
7690af3f ACM |
112 | dccp_hdr_reset(skb)->dccph_reset_code = |
113 | dcb->dccpd_reset_code; | |
7c657876 ACM |
114 | break; |
115 | } | |
116 | ||
57cca05a | 117 | icsk->icsk_af_ops->send_check(sk, skb->len, skb); |
7c657876 | 118 | |
7ad07e7c | 119 | if (set_ack) |
7c657876 ACM |
120 | dccp_event_ack_sent(sk); |
121 | ||
122 | DCCP_INC_STATS(DCCP_MIB_OUTSEGS); | |
123 | ||
49c5bfaf | 124 | memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); |
57cca05a | 125 | err = icsk->icsk_af_ops->queue_xmit(skb, 0); |
7c657876 ACM |
126 | if (err <= 0) |
127 | return err; | |
128 | ||
129 | /* NET_XMIT_CN is special. It does not guarantee, | |
130 | * that this packet is lost. It tells that device | |
131 | * is about to start to drop packets or already | |
132 | * drops some packets of the same priority and | |
133 | * invokes us to send less aggressively. | |
134 | */ | |
135 | return err == NET_XMIT_CN ? 0 : err; | |
136 | } | |
137 | return -ENOBUFS; | |
138 | } | |
139 | ||
140 | unsigned int dccp_sync_mss(struct sock *sk, u32 pmtu) | |
141 | { | |
d83d8461 | 142 | struct inet_connection_sock *icsk = inet_csk(sk); |
7c657876 | 143 | struct dccp_sock *dp = dccp_sk(sk); |
d83d8461 | 144 | int mss_now = (pmtu - icsk->icsk_af_ops->net_header_len - |
57cca05a | 145 | sizeof(struct dccp_hdr) - sizeof(struct dccp_hdr_ext)); |
7c657876 ACM |
146 | |
147 | /* Now subtract optional transport overhead */ | |
d83d8461 | 148 | mss_now -= icsk->icsk_ext_hdr_len; |
7c657876 ACM |
149 | |
150 | /* | |
151 | * FIXME: this should come from the CCID infrastructure, where, say, | |
152 | * TFRC will say it wants TIMESTAMPS, ELAPSED time, etc, for now lets | |
153 | * put a rough estimate for NDP + TIMESTAMP + TIMESTAMP_ECHO + ELAPSED | |
154 | * TIME + TFRC_OPT_LOSS_EVENT_RATE + TFRC_OPT_RECEIVE_RATE + padding to | |
155 | * make it a multiple of 4 | |
156 | */ | |
157 | ||
158 | mss_now -= ((5 + 6 + 10 + 6 + 6 + 6 + 3) / 4) * 4; | |
159 | ||
160 | /* And store cached results */ | |
d83d8461 | 161 | icsk->icsk_pmtu_cookie = pmtu; |
7c657876 ACM |
162 | dp->dccps_mss_cache = mss_now; |
163 | ||
164 | return mss_now; | |
165 | } | |
166 | ||
f21e68ca ACM |
167 | EXPORT_SYMBOL_GPL(dccp_sync_mss); |
168 | ||
c530cfb1 ACM |
169 | void dccp_write_space(struct sock *sk) |
170 | { | |
171 | read_lock(&sk->sk_callback_lock); | |
172 | ||
173 | if (sk->sk_sleep && waitqueue_active(sk->sk_sleep)) | |
174 | wake_up_interruptible(sk->sk_sleep); | |
175 | /* Should agree with poll, otherwise some programs break */ | |
176 | if (sock_writeable(sk)) | |
177 | sk_wake_async(sk, 2, POLL_OUT); | |
178 | ||
179 | read_unlock(&sk->sk_callback_lock); | |
180 | } | |
181 | ||
d6809c12 ACM |
182 | /** |
183 | * dccp_wait_for_ccid - Wait for ccid to tell us we can send a packet | |
184 | * @sk: socket to wait for | |
185 | * @timeo: for how long | |
186 | */ | |
187 | static int dccp_wait_for_ccid(struct sock *sk, struct sk_buff *skb, | |
188 | long *timeo) | |
189 | { | |
190 | struct dccp_sock *dp = dccp_sk(sk); | |
191 | DEFINE_WAIT(wait); | |
192 | long delay; | |
193 | int rc; | |
194 | ||
195 | while (1) { | |
196 | prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE); | |
197 | ||
198 | if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN)) | |
199 | goto do_error; | |
200 | if (!*timeo) | |
201 | goto do_nonblock; | |
202 | if (signal_pending(current)) | |
203 | goto do_interrupted; | |
204 | ||
205 | rc = ccid_hc_tx_send_packet(dp->dccps_hc_tx_ccid, sk, skb, | |
206 | skb->len); | |
207 | if (rc <= 0) | |
208 | break; | |
209 | delay = msecs_to_jiffies(rc); | |
210 | if (delay > *timeo || delay < 0) | |
211 | goto do_nonblock; | |
212 | ||
213 | sk->sk_write_pending++; | |
214 | release_sock(sk); | |
215 | *timeo -= schedule_timeout(delay); | |
216 | lock_sock(sk); | |
217 | sk->sk_write_pending--; | |
218 | } | |
219 | out: | |
220 | finish_wait(sk->sk_sleep, &wait); | |
221 | return rc; | |
222 | ||
223 | do_error: | |
224 | rc = -EPIPE; | |
225 | goto out; | |
226 | do_nonblock: | |
227 | rc = -EAGAIN; | |
228 | goto out; | |
229 | do_interrupted: | |
230 | rc = sock_intr_errno(*timeo); | |
231 | goto out; | |
232 | } | |
233 | ||
234 | int dccp_write_xmit(struct sock *sk, struct sk_buff *skb, long *timeo) | |
27258ee5 ACM |
235 | { |
236 | const struct dccp_sock *dp = dccp_sk(sk); | |
d6809c12 ACM |
237 | int err = ccid_hc_tx_send_packet(dp->dccps_hc_tx_ccid, sk, skb, |
238 | skb->len); | |
239 | ||
240 | if (err > 0) | |
241 | err = dccp_wait_for_ccid(sk, skb, timeo); | |
27258ee5 ACM |
242 | |
243 | if (err == 0) { | |
27258ee5 | 244 | struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb); |
d6809c12 | 245 | const int len = skb->len; |
27258ee5 ACM |
246 | |
247 | if (sk->sk_state == DCCP_PARTOPEN) { | |
248 | /* See 8.1.5. Handshake Completion */ | |
249 | inet_csk_schedule_ack(sk); | |
250 | inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK, | |
251 | inet_csk(sk)->icsk_rto, | |
252 | DCCP_RTO_MAX); | |
253 | dcb->dccpd_type = DCCP_PKT_DATAACK; | |
ae31c339 | 254 | } else if (dccp_ack_pending(sk)) |
27258ee5 ACM |
255 | dcb->dccpd_type = DCCP_PKT_DATAACK; |
256 | else | |
257 | dcb->dccpd_type = DCCP_PKT_DATA; | |
258 | ||
259 | err = dccp_transmit_skb(sk, skb); | |
260 | ccid_hc_tx_packet_sent(dp->dccps_hc_tx_ccid, sk, 0, len); | |
ffa29347 HX |
261 | } else |
262 | kfree_skb(skb); | |
27258ee5 ACM |
263 | |
264 | return err; | |
265 | } | |
266 | ||
7c657876 ACM |
267 | int dccp_retransmit_skb(struct sock *sk, struct sk_buff *skb) |
268 | { | |
57cca05a | 269 | if (inet_csk(sk)->icsk_af_ops->rebuild_header(sk) != 0) |
7c657876 ACM |
270 | return -EHOSTUNREACH; /* Routing failure or similar. */ |
271 | ||
272 | return dccp_transmit_skb(sk, (skb_cloned(skb) ? | |
273 | pskb_copy(skb, GFP_ATOMIC): | |
274 | skb_clone(skb, GFP_ATOMIC))); | |
275 | } | |
276 | ||
277 | struct sk_buff *dccp_make_response(struct sock *sk, struct dst_entry *dst, | |
278 | struct request_sock *req) | |
279 | { | |
280 | struct dccp_hdr *dh; | |
67e6b629 | 281 | struct dccp_request_sock *dreq; |
118b2c95 | 282 | const u32 dccp_header_size = sizeof(struct dccp_hdr) + |
7c657876 ACM |
283 | sizeof(struct dccp_hdr_ext) + |
284 | sizeof(struct dccp_hdr_response); | |
118b2c95 | 285 | struct sk_buff *skb = sock_wmalloc(sk, sk->sk_prot->max_header, 1, |
7c657876 ACM |
286 | GFP_ATOMIC); |
287 | if (skb == NULL) | |
288 | return NULL; | |
289 | ||
290 | /* Reserve space for headers. */ | |
118b2c95 | 291 | skb_reserve(skb, sk->sk_prot->max_header); |
7c657876 ACM |
292 | |
293 | skb->dst = dst_clone(dst); | |
294 | skb->csum = 0; | |
295 | ||
67e6b629 | 296 | dreq = dccp_rsk(req); |
7c657876 | 297 | DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_RESPONSE; |
67e6b629 | 298 | DCCP_SKB_CB(skb)->dccpd_seq = dreq->dreq_iss; |
7c657876 ACM |
299 | dccp_insert_options(sk, skb); |
300 | ||
301 | skb->h.raw = skb_push(skb, dccp_header_size); | |
302 | ||
303 | dh = dccp_hdr(skb); | |
304 | memset(dh, 0, dccp_header_size); | |
305 | ||
306 | dh->dccph_sport = inet_sk(sk)->sport; | |
307 | dh->dccph_dport = inet_rsk(req)->rmt_port; | |
7690af3f ACM |
308 | dh->dccph_doff = (dccp_header_size + |
309 | DCCP_SKB_CB(skb)->dccpd_opt_len) / 4; | |
7c657876 ACM |
310 | dh->dccph_type = DCCP_PKT_RESPONSE; |
311 | dh->dccph_x = 1; | |
67e6b629 ACM |
312 | dccp_hdr_set_seq(dh, dreq->dreq_iss); |
313 | dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), dreq->dreq_isr); | |
314 | dccp_hdr_response(skb)->dccph_resp_service = dreq->dreq_service; | |
7c657876 | 315 | |
7c657876 ACM |
316 | DCCP_INC_STATS(DCCP_MIB_OUTSEGS); |
317 | return skb; | |
318 | } | |
319 | ||
f21e68ca ACM |
320 | EXPORT_SYMBOL_GPL(dccp_make_response); |
321 | ||
017487d7 ACM |
322 | static struct sk_buff *dccp_make_reset(struct sock *sk, struct dst_entry *dst, |
323 | const enum dccp_reset_codes code) | |
7c657876 ACM |
324 | |
325 | { | |
326 | struct dccp_hdr *dh; | |
327 | struct dccp_sock *dp = dccp_sk(sk); | |
118b2c95 | 328 | const u32 dccp_header_size = sizeof(struct dccp_hdr) + |
7c657876 ACM |
329 | sizeof(struct dccp_hdr_ext) + |
330 | sizeof(struct dccp_hdr_reset); | |
118b2c95 | 331 | struct sk_buff *skb = sock_wmalloc(sk, sk->sk_prot->max_header, 1, |
7c657876 ACM |
332 | GFP_ATOMIC); |
333 | if (skb == NULL) | |
334 | return NULL; | |
335 | ||
336 | /* Reserve space for headers. */ | |
118b2c95 | 337 | skb_reserve(skb, sk->sk_prot->max_header); |
7c657876 ACM |
338 | |
339 | skb->dst = dst_clone(dst); | |
340 | skb->csum = 0; | |
341 | ||
342 | dccp_inc_seqno(&dp->dccps_gss); | |
343 | ||
344 | DCCP_SKB_CB(skb)->dccpd_reset_code = code; | |
345 | DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_RESET; | |
346 | DCCP_SKB_CB(skb)->dccpd_seq = dp->dccps_gss; | |
347 | dccp_insert_options(sk, skb); | |
348 | ||
349 | skb->h.raw = skb_push(skb, dccp_header_size); | |
350 | ||
351 | dh = dccp_hdr(skb); | |
352 | memset(dh, 0, dccp_header_size); | |
353 | ||
354 | dh->dccph_sport = inet_sk(sk)->sport; | |
355 | dh->dccph_dport = inet_sk(sk)->dport; | |
7690af3f ACM |
356 | dh->dccph_doff = (dccp_header_size + |
357 | DCCP_SKB_CB(skb)->dccpd_opt_len) / 4; | |
7c657876 ACM |
358 | dh->dccph_type = DCCP_PKT_RESET; |
359 | dh->dccph_x = 1; | |
360 | dccp_hdr_set_seq(dh, dp->dccps_gss); | |
361 | dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), dp->dccps_gsr); | |
362 | ||
363 | dccp_hdr_reset(skb)->dccph_reset_code = code; | |
017487d7 | 364 | inet_csk(sk)->icsk_af_ops->send_check(sk, skb->len, skb); |
7c657876 ACM |
365 | |
366 | DCCP_INC_STATS(DCCP_MIB_OUTSEGS); | |
367 | return skb; | |
368 | } | |
369 | ||
017487d7 ACM |
370 | int dccp_send_reset(struct sock *sk, enum dccp_reset_codes code) |
371 | { | |
372 | /* | |
373 | * FIXME: what if rebuild_header fails? | |
374 | * Should we be doing a rebuild_header here? | |
375 | */ | |
376 | int err = inet_sk_rebuild_header(sk); | |
377 | ||
378 | if (err == 0) { | |
379 | struct sk_buff *skb = dccp_make_reset(sk, sk->sk_dst_cache, | |
380 | code); | |
381 | if (skb != NULL) { | |
382 | memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); | |
383 | err = inet_csk(sk)->icsk_af_ops->queue_xmit(skb, 0); | |
384 | if (err == NET_XMIT_CN) | |
385 | err = 0; | |
386 | } | |
387 | } | |
388 | ||
389 | return err; | |
390 | } | |
391 | ||
7c657876 ACM |
392 | /* |
393 | * Do all connect socket setups that can be done AF independent. | |
394 | */ | |
395 | static inline void dccp_connect_init(struct sock *sk) | |
396 | { | |
f21e68ca | 397 | struct dccp_sock *dp = dccp_sk(sk); |
7c657876 ACM |
398 | struct dst_entry *dst = __sk_dst_get(sk); |
399 | struct inet_connection_sock *icsk = inet_csk(sk); | |
400 | ||
401 | sk->sk_err = 0; | |
402 | sock_reset_flag(sk, SOCK_DONE); | |
403 | ||
404 | dccp_sync_mss(sk, dst_mtu(dst)); | |
405 | ||
f21e68ca ACM |
406 | dccp_update_gss(sk, dp->dccps_iss); |
407 | /* | |
408 | * SWL and AWL are initially adjusted so that they are not less than | |
409 | * the initial Sequence Numbers received and sent, respectively: | |
410 | * SWL := max(GSR + 1 - floor(W/4), ISR), | |
411 | * AWL := max(GSS - W' + 1, ISS). | |
412 | * These adjustments MUST be applied only at the beginning of the | |
413 | * connection. | |
414 | */ | |
415 | dccp_set_seqno(&dp->dccps_awl, max48(dp->dccps_awl, dp->dccps_iss)); | |
7c657876 ACM |
416 | |
417 | icsk->icsk_retransmits = 0; | |
418 | } | |
419 | ||
420 | int dccp_connect(struct sock *sk) | |
421 | { | |
422 | struct sk_buff *skb; | |
423 | struct inet_connection_sock *icsk = inet_csk(sk); | |
424 | ||
425 | dccp_connect_init(sk); | |
426 | ||
118b2c95 | 427 | skb = alloc_skb(sk->sk_prot->max_header, sk->sk_allocation); |
7c657876 ACM |
428 | if (unlikely(skb == NULL)) |
429 | return -ENOBUFS; | |
430 | ||
431 | /* Reserve space for headers. */ | |
118b2c95 | 432 | skb_reserve(skb, sk->sk_prot->max_header); |
7c657876 ACM |
433 | |
434 | DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_REQUEST; | |
7c657876 | 435 | skb->csum = 0; |
7c657876 | 436 | |
48918a4d | 437 | dccp_skb_entail(sk, skb); |
7c657876 ACM |
438 | dccp_transmit_skb(sk, skb_clone(skb, GFP_KERNEL)); |
439 | DCCP_INC_STATS(DCCP_MIB_ACTIVEOPENS); | |
440 | ||
441 | /* Timer for repeating the REQUEST until an answer. */ | |
27258ee5 ACM |
442 | inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, |
443 | icsk->icsk_rto, DCCP_RTO_MAX); | |
7c657876 ACM |
444 | return 0; |
445 | } | |
446 | ||
f21e68ca ACM |
447 | EXPORT_SYMBOL_GPL(dccp_connect); |
448 | ||
7c657876 ACM |
449 | void dccp_send_ack(struct sock *sk) |
450 | { | |
451 | /* If we have been reset, we may not send again. */ | |
452 | if (sk->sk_state != DCCP_CLOSED) { | |
118b2c95 ACM |
453 | struct sk_buff *skb = alloc_skb(sk->sk_prot->max_header, |
454 | GFP_ATOMIC); | |
7c657876 ACM |
455 | |
456 | if (skb == NULL) { | |
457 | inet_csk_schedule_ack(sk); | |
458 | inet_csk(sk)->icsk_ack.ato = TCP_ATO_MIN; | |
7690af3f ACM |
459 | inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK, |
460 | TCP_DELACK_MAX, | |
461 | DCCP_RTO_MAX); | |
7c657876 ACM |
462 | return; |
463 | } | |
464 | ||
465 | /* Reserve space for headers */ | |
118b2c95 | 466 | skb_reserve(skb, sk->sk_prot->max_header); |
7c657876 ACM |
467 | skb->csum = 0; |
468 | DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_ACK; | |
7c657876 ACM |
469 | dccp_transmit_skb(sk, skb); |
470 | } | |
471 | } | |
472 | ||
473 | EXPORT_SYMBOL_GPL(dccp_send_ack); | |
474 | ||
475 | void dccp_send_delayed_ack(struct sock *sk) | |
476 | { | |
477 | struct inet_connection_sock *icsk = inet_csk(sk); | |
478 | /* | |
479 | * FIXME: tune this timer. elapsed time fixes the skew, so no problem | |
480 | * with using 2s, and active senders also piggyback the ACK into a | |
481 | * DATAACK packet, so this is really for quiescent senders. | |
482 | */ | |
483 | unsigned long timeout = jiffies + 2 * HZ; | |
484 | ||
485 | /* Use new timeout only if there wasn't a older one earlier. */ | |
486 | if (icsk->icsk_ack.pending & ICSK_ACK_TIMER) { | |
487 | /* If delack timer was blocked or is about to expire, | |
488 | * send ACK now. | |
489 | * | |
490 | * FIXME: check the "about to expire" part | |
491 | */ | |
492 | if (icsk->icsk_ack.blocked) { | |
493 | dccp_send_ack(sk); | |
494 | return; | |
495 | } | |
496 | ||
497 | if (!time_before(timeout, icsk->icsk_ack.timeout)) | |
498 | timeout = icsk->icsk_ack.timeout; | |
499 | } | |
500 | icsk->icsk_ack.pending |= ICSK_ACK_SCHED | ICSK_ACK_TIMER; | |
501 | icsk->icsk_ack.timeout = timeout; | |
502 | sk_reset_timer(sk, &icsk->icsk_delack_timer, timeout); | |
503 | } | |
504 | ||
e92ae93a ACM |
505 | void dccp_send_sync(struct sock *sk, const u64 seq, |
506 | const enum dccp_pkt_type pkt_type) | |
7c657876 ACM |
507 | { |
508 | /* | |
509 | * We are not putting this on the write queue, so | |
510 | * dccp_transmit_skb() will set the ownership to this | |
511 | * sock. | |
512 | */ | |
118b2c95 | 513 | struct sk_buff *skb = alloc_skb(sk->sk_prot->max_header, GFP_ATOMIC); |
7c657876 ACM |
514 | |
515 | if (skb == NULL) | |
516 | /* FIXME: how to make sure the sync is sent? */ | |
517 | return; | |
518 | ||
519 | /* Reserve space for headers and prepare control bits. */ | |
118b2c95 | 520 | skb_reserve(skb, sk->sk_prot->max_header); |
7c657876 | 521 | skb->csum = 0; |
e92ae93a | 522 | DCCP_SKB_CB(skb)->dccpd_type = pkt_type; |
7c657876 ACM |
523 | DCCP_SKB_CB(skb)->dccpd_seq = seq; |
524 | ||
7c657876 ACM |
525 | dccp_transmit_skb(sk, skb); |
526 | } | |
527 | ||
b61fafc4 ACM |
528 | EXPORT_SYMBOL_GPL(dccp_send_sync); |
529 | ||
7690af3f ACM |
530 | /* |
531 | * Send a DCCP_PKT_CLOSE/CLOSEREQ. The caller locks the socket for us. This | |
532 | * cannot be allowed to fail queueing a DCCP_PKT_CLOSE/CLOSEREQ frame under | |
533 | * any circumstances. | |
7c657876 | 534 | */ |
7ad07e7c | 535 | void dccp_send_close(struct sock *sk, const int active) |
7c657876 ACM |
536 | { |
537 | struct dccp_sock *dp = dccp_sk(sk); | |
538 | struct sk_buff *skb; | |
7d877f3b | 539 | const gfp_t prio = active ? GFP_KERNEL : GFP_ATOMIC; |
7c657876 | 540 | |
7ad07e7c ACM |
541 | skb = alloc_skb(sk->sk_prot->max_header, prio); |
542 | if (skb == NULL) | |
543 | return; | |
7c657876 ACM |
544 | |
545 | /* Reserve space for headers and prepare control bits. */ | |
546 | skb_reserve(skb, sk->sk_prot->max_header); | |
547 | skb->csum = 0; | |
7690af3f ACM |
548 | DCCP_SKB_CB(skb)->dccpd_type = dp->dccps_role == DCCP_ROLE_CLIENT ? |
549 | DCCP_PKT_CLOSE : DCCP_PKT_CLOSEREQ; | |
7c657876 | 550 | |
7ad07e7c | 551 | if (active) { |
48918a4d | 552 | dccp_skb_entail(sk, skb); |
7ad07e7c ACM |
553 | dccp_transmit_skb(sk, skb_clone(skb, prio)); |
554 | } else | |
555 | dccp_transmit_skb(sk, skb); | |
7c657876 | 556 | } |