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 | ||
7c657876 | 13 | #include <linux/dccp.h> |
48918a4d | 14 | #include <linux/kernel.h> |
7c657876 ACM |
15 | #include <linux/skbuff.h> |
16 | ||
14c85021 | 17 | #include <net/inet_sock.h> |
7c657876 ACM |
18 | #include <net/sock.h> |
19 | ||
ae31c339 | 20 | #include "ackvec.h" |
7c657876 ACM |
21 | #include "ccid.h" |
22 | #include "dccp.h" | |
23 | ||
24 | static inline void dccp_event_ack_sent(struct sock *sk) | |
25 | { | |
26 | inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK); | |
27 | } | |
28 | ||
c25a18ba | 29 | static void dccp_skb_entail(struct sock *sk, struct sk_buff *skb) |
48918a4d HX |
30 | { |
31 | skb_set_owner_w(skb, sk); | |
32 | WARN_ON(sk->sk_send_head); | |
33 | sk->sk_send_head = skb; | |
34 | } | |
35 | ||
7c657876 ACM |
36 | /* |
37 | * All SKB's seen here are completely headerless. It is our | |
38 | * job to build the DCCP header, and pass the packet down to | |
39 | * IP so it can do the same plus pass the packet off to the | |
40 | * device. | |
41 | */ | |
48918a4d | 42 | static int dccp_transmit_skb(struct sock *sk, struct sk_buff *skb) |
7c657876 ACM |
43 | { |
44 | if (likely(skb != NULL)) { | |
45 | const struct inet_sock *inet = inet_sk(sk); | |
57cca05a | 46 | const struct inet_connection_sock *icsk = inet_csk(sk); |
7c657876 ACM |
47 | struct dccp_sock *dp = dccp_sk(sk); |
48 | struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb); | |
49 | struct dccp_hdr *dh; | |
50 | /* XXX For now we're using only 48 bits sequence numbers */ | |
118b2c95 | 51 | const u32 dccp_header_size = sizeof(*dh) + |
7c657876 | 52 | sizeof(struct dccp_hdr_ext) + |
7690af3f | 53 | dccp_packet_hdr_len(dcb->dccpd_type); |
7c657876 ACM |
54 | int err, set_ack = 1; |
55 | u64 ackno = dp->dccps_gsr; | |
56 | ||
7c657876 ACM |
57 | dccp_inc_seqno(&dp->dccps_gss); |
58 | ||
7c657876 ACM |
59 | switch (dcb->dccpd_type) { |
60 | case DCCP_PKT_DATA: | |
61 | set_ack = 0; | |
edc9e819 HX |
62 | /* fall through */ |
63 | case DCCP_PKT_DATAACK: | |
7c657876 | 64 | break; |
edc9e819 | 65 | |
afe00251 AB |
66 | case DCCP_PKT_REQUEST: |
67 | set_ack = 0; | |
68 | /* fall through */ | |
69 | ||
7c657876 ACM |
70 | case DCCP_PKT_SYNC: |
71 | case DCCP_PKT_SYNCACK: | |
72 | ackno = dcb->dccpd_seq; | |
edc9e819 HX |
73 | /* fall through */ |
74 | default: | |
75 | /* | |
76 | * Only data packets should come through with skb->sk | |
77 | * set. | |
78 | */ | |
79 | WARN_ON(skb->sk); | |
80 | skb_set_owner_w(skb, sk); | |
7c657876 ACM |
81 | break; |
82 | } | |
24117727 ACM |
83 | |
84 | dcb->dccpd_seq = dp->dccps_gss; | |
2d0817d1 ACM |
85 | |
86 | if (dccp_insert_options(sk, skb)) { | |
87 | kfree_skb(skb); | |
88 | return -EPROTO; | |
89 | } | |
7c657876 | 90 | |
fda0fd6c | 91 | |
7c657876 | 92 | /* Build DCCP header and checksum it. */ |
9b42078e | 93 | dh = dccp_zeroed_hdr(skb, dccp_header_size); |
7c657876 ACM |
94 | dh->dccph_type = dcb->dccpd_type; |
95 | dh->dccph_sport = inet->sport; | |
96 | dh->dccph_dport = inet->dport; | |
97 | dh->dccph_doff = (dccp_header_size + dcb->dccpd_opt_len) / 4; | |
98 | dh->dccph_ccval = dcb->dccpd_ccval; | |
6f4e5fff | 99 | dh->dccph_cscov = dp->dccps_pcslen; |
7c657876 ACM |
100 | /* XXX For now we're using only 48 bits sequence numbers */ |
101 | dh->dccph_x = 1; | |
102 | ||
103 | dp->dccps_awh = dp->dccps_gss; | |
104 | dccp_hdr_set_seq(dh, dp->dccps_gss); | |
105 | if (set_ack) | |
106 | dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), ackno); | |
107 | ||
108 | switch (dcb->dccpd_type) { | |
109 | case DCCP_PKT_REQUEST: | |
7690af3f | 110 | dccp_hdr_request(skb)->dccph_req_service = |
67e6b629 | 111 | dp->dccps_service; |
7c657876 ACM |
112 | break; |
113 | case DCCP_PKT_RESET: | |
7690af3f ACM |
114 | dccp_hdr_reset(skb)->dccph_reset_code = |
115 | dcb->dccpd_reset_code; | |
7c657876 ACM |
116 | break; |
117 | } | |
118 | ||
6f4e5fff | 119 | icsk->icsk_af_ops->send_check(sk, 0, skb); |
7c657876 | 120 | |
7ad07e7c | 121 | if (set_ack) |
7c657876 ACM |
122 | dccp_event_ack_sent(sk); |
123 | ||
124 | DCCP_INC_STATS(DCCP_MIB_OUTSEGS); | |
125 | ||
49c5bfaf | 126 | memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); |
93173112 | 127 | err = icsk->icsk_af_ops->queue_xmit(skb, sk, 0); |
7c657876 ACM |
128 | if (err <= 0) |
129 | return err; | |
130 | ||
131 | /* NET_XMIT_CN is special. It does not guarantee, | |
132 | * that this packet is lost. It tells that device | |
133 | * is about to start to drop packets or already | |
134 | * drops some packets of the same priority and | |
135 | * invokes us to send less aggressively. | |
136 | */ | |
137 | return err == NET_XMIT_CN ? 0 : err; | |
138 | } | |
139 | return -ENOBUFS; | |
140 | } | |
141 | ||
142 | unsigned int dccp_sync_mss(struct sock *sk, u32 pmtu) | |
143 | { | |
d83d8461 | 144 | struct inet_connection_sock *icsk = inet_csk(sk); |
7c657876 | 145 | struct dccp_sock *dp = dccp_sk(sk); |
d83d8461 | 146 | int mss_now = (pmtu - icsk->icsk_af_ops->net_header_len - |
57cca05a | 147 | sizeof(struct dccp_hdr) - sizeof(struct dccp_hdr_ext)); |
7c657876 ACM |
148 | |
149 | /* Now subtract optional transport overhead */ | |
d83d8461 | 150 | mss_now -= icsk->icsk_ext_hdr_len; |
7c657876 ACM |
151 | |
152 | /* | |
153 | * FIXME: this should come from the CCID infrastructure, where, say, | |
154 | * TFRC will say it wants TIMESTAMPS, ELAPSED time, etc, for now lets | |
155 | * put a rough estimate for NDP + TIMESTAMP + TIMESTAMP_ECHO + ELAPSED | |
156 | * TIME + TFRC_OPT_LOSS_EVENT_RATE + TFRC_OPT_RECEIVE_RATE + padding to | |
157 | * make it a multiple of 4 | |
158 | */ | |
159 | ||
160 | mss_now -= ((5 + 6 + 10 + 6 + 6 + 6 + 3) / 4) * 4; | |
161 | ||
162 | /* And store cached results */ | |
d83d8461 | 163 | icsk->icsk_pmtu_cookie = pmtu; |
7c657876 ACM |
164 | dp->dccps_mss_cache = mss_now; |
165 | ||
166 | return mss_now; | |
167 | } | |
168 | ||
f21e68ca ACM |
169 | EXPORT_SYMBOL_GPL(dccp_sync_mss); |
170 | ||
c530cfb1 ACM |
171 | void dccp_write_space(struct sock *sk) |
172 | { | |
173 | read_lock(&sk->sk_callback_lock); | |
174 | ||
175 | if (sk->sk_sleep && waitqueue_active(sk->sk_sleep)) | |
176 | wake_up_interruptible(sk->sk_sleep); | |
177 | /* Should agree with poll, otherwise some programs break */ | |
178 | if (sock_writeable(sk)) | |
179 | sk_wake_async(sk, 2, POLL_OUT); | |
180 | ||
181 | read_unlock(&sk->sk_callback_lock); | |
182 | } | |
183 | ||
d6809c12 ACM |
184 | /** |
185 | * dccp_wait_for_ccid - Wait for ccid to tell us we can send a packet | |
186 | * @sk: socket to wait for | |
187 | * @timeo: for how long | |
188 | */ | |
189 | static int dccp_wait_for_ccid(struct sock *sk, struct sk_buff *skb, | |
190 | long *timeo) | |
191 | { | |
192 | struct dccp_sock *dp = dccp_sk(sk); | |
193 | DEFINE_WAIT(wait); | |
194 | long delay; | |
195 | int rc; | |
196 | ||
197 | while (1) { | |
198 | prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE); | |
199 | ||
97e5848d | 200 | if (sk->sk_err) |
d6809c12 ACM |
201 | goto do_error; |
202 | if (!*timeo) | |
203 | goto do_nonblock; | |
204 | if (signal_pending(current)) | |
205 | goto do_interrupted; | |
206 | ||
207 | rc = ccid_hc_tx_send_packet(dp->dccps_hc_tx_ccid, sk, skb, | |
208 | skb->len); | |
209 | if (rc <= 0) | |
210 | break; | |
211 | delay = msecs_to_jiffies(rc); | |
212 | if (delay > *timeo || delay < 0) | |
213 | goto do_nonblock; | |
214 | ||
215 | sk->sk_write_pending++; | |
216 | release_sock(sk); | |
217 | *timeo -= schedule_timeout(delay); | |
218 | lock_sock(sk); | |
219 | sk->sk_write_pending--; | |
220 | } | |
221 | out: | |
222 | finish_wait(sk->sk_sleep, &wait); | |
223 | return rc; | |
224 | ||
225 | do_error: | |
226 | rc = -EPIPE; | |
227 | goto out; | |
228 | do_nonblock: | |
229 | rc = -EAGAIN; | |
230 | goto out; | |
231 | do_interrupted: | |
232 | rc = sock_intr_errno(*timeo); | |
233 | goto out; | |
234 | } | |
235 | ||
97e5848d IM |
236 | static void dccp_write_xmit_timer(unsigned long data) { |
237 | struct sock *sk = (struct sock *)data; | |
238 | struct dccp_sock *dp = dccp_sk(sk); | |
239 | ||
240 | bh_lock_sock(sk); | |
241 | if (sock_owned_by_user(sk)) | |
242 | sk_reset_timer(sk, &dp->dccps_xmit_timer, jiffies+1); | |
243 | else | |
244 | dccp_write_xmit(sk, 0); | |
245 | bh_unlock_sock(sk); | |
246 | sock_put(sk); | |
247 | } | |
248 | ||
249 | void dccp_write_xmit(struct sock *sk, int block) | |
27258ee5 | 250 | { |
97e5848d IM |
251 | struct dccp_sock *dp = dccp_sk(sk); |
252 | struct sk_buff *skb; | |
f45b3ec4 IM |
253 | long timeo = DCCP_XMIT_TIMEO; /* If a packet is taking longer than |
254 | this we have other issues */ | |
97e5848d IM |
255 | |
256 | while ((skb = skb_peek(&sk->sk_write_queue))) { | |
257 | int err = ccid_hc_tx_send_packet(dp->dccps_hc_tx_ccid, sk, skb, | |
d6809c12 ACM |
258 | skb->len); |
259 | ||
97e5848d IM |
260 | if (err > 0) { |
261 | if (!block) { | |
262 | sk_reset_timer(sk, &dp->dccps_xmit_timer, | |
263 | msecs_to_jiffies(err)+jiffies); | |
264 | break; | |
f45b3ec4 | 265 | } else { |
97e5848d | 266 | err = dccp_wait_for_ccid(sk, skb, &timeo); |
f45b3ec4 IM |
267 | timeo = DCCP_XMIT_TIMEO; |
268 | } | |
97e5848d IM |
269 | if (err) { |
270 | printk(KERN_CRIT "%s:err at dccp_wait_for_ccid" | |
271 | " %d\n", __FUNCTION__, err); | |
272 | dump_stack(); | |
273 | } | |
274 | } | |
27258ee5 | 275 | |
97e5848d IM |
276 | skb_dequeue(&sk->sk_write_queue); |
277 | if (err == 0) { | |
278 | struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb); | |
279 | const int len = skb->len; | |
27258ee5 | 280 | |
97e5848d IM |
281 | if (sk->sk_state == DCCP_PARTOPEN) { |
282 | /* See 8.1.5. Handshake Completion */ | |
283 | inet_csk_schedule_ack(sk); | |
284 | inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK, | |
27258ee5 ACM |
285 | inet_csk(sk)->icsk_rto, |
286 | DCCP_RTO_MAX); | |
97e5848d IM |
287 | dcb->dccpd_type = DCCP_PKT_DATAACK; |
288 | } else if (dccp_ack_pending(sk)) | |
289 | dcb->dccpd_type = DCCP_PKT_DATAACK; | |
290 | else | |
291 | dcb->dccpd_type = DCCP_PKT_DATA; | |
292 | ||
293 | err = dccp_transmit_skb(sk, skb); | |
294 | ccid_hc_tx_packet_sent(dp->dccps_hc_tx_ccid, sk, 0, len); | |
295 | if (err) { | |
296 | printk(KERN_CRIT "%s:err from " | |
297 | "ccid_hc_tx_packet_sent %d\n", | |
298 | __FUNCTION__, err); | |
299 | dump_stack(); | |
300 | } | |
301 | } else | |
302 | kfree(skb); | |
303 | } | |
27258ee5 ACM |
304 | } |
305 | ||
7c657876 ACM |
306 | int dccp_retransmit_skb(struct sock *sk, struct sk_buff *skb) |
307 | { | |
57cca05a | 308 | if (inet_csk(sk)->icsk_af_ops->rebuild_header(sk) != 0) |
7c657876 ACM |
309 | return -EHOSTUNREACH; /* Routing failure or similar. */ |
310 | ||
311 | return dccp_transmit_skb(sk, (skb_cloned(skb) ? | |
312 | pskb_copy(skb, GFP_ATOMIC): | |
313 | skb_clone(skb, GFP_ATOMIC))); | |
314 | } | |
315 | ||
316 | struct sk_buff *dccp_make_response(struct sock *sk, struct dst_entry *dst, | |
317 | struct request_sock *req) | |
318 | { | |
319 | struct dccp_hdr *dh; | |
67e6b629 | 320 | struct dccp_request_sock *dreq; |
118b2c95 | 321 | const u32 dccp_header_size = sizeof(struct dccp_hdr) + |
7c657876 ACM |
322 | sizeof(struct dccp_hdr_ext) + |
323 | sizeof(struct dccp_hdr_response); | |
118b2c95 | 324 | struct sk_buff *skb = sock_wmalloc(sk, sk->sk_prot->max_header, 1, |
7c657876 ACM |
325 | GFP_ATOMIC); |
326 | if (skb == NULL) | |
327 | return NULL; | |
328 | ||
329 | /* Reserve space for headers. */ | |
118b2c95 | 330 | skb_reserve(skb, sk->sk_prot->max_header); |
7c657876 ACM |
331 | |
332 | skb->dst = dst_clone(dst); | |
7c657876 | 333 | |
67e6b629 | 334 | dreq = dccp_rsk(req); |
e11d9d30 GR |
335 | if (inet_rsk(req)->acked) /* increase ISS upon retransmission */ |
336 | dccp_inc_seqno(&dreq->dreq_iss); | |
7c657876 | 337 | DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_RESPONSE; |
67e6b629 | 338 | DCCP_SKB_CB(skb)->dccpd_seq = dreq->dreq_iss; |
2d0817d1 ACM |
339 | |
340 | if (dccp_insert_options(sk, skb)) { | |
341 | kfree_skb(skb); | |
342 | return NULL; | |
343 | } | |
7c657876 | 344 | |
9b42078e | 345 | dh = dccp_zeroed_hdr(skb, dccp_header_size); |
7c657876 ACM |
346 | |
347 | dh->dccph_sport = inet_sk(sk)->sport; | |
348 | dh->dccph_dport = inet_rsk(req)->rmt_port; | |
7690af3f ACM |
349 | dh->dccph_doff = (dccp_header_size + |
350 | DCCP_SKB_CB(skb)->dccpd_opt_len) / 4; | |
7c657876 ACM |
351 | dh->dccph_type = DCCP_PKT_RESPONSE; |
352 | dh->dccph_x = 1; | |
67e6b629 ACM |
353 | dccp_hdr_set_seq(dh, dreq->dreq_iss); |
354 | dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), dreq->dreq_isr); | |
355 | dccp_hdr_response(skb)->dccph_resp_service = dreq->dreq_service; | |
7c657876 | 356 | |
6f4e5fff GR |
357 | dccp_csum_outgoing(skb); |
358 | ||
e11d9d30 GR |
359 | /* We use `acked' to remember that a Response was already sent. */ |
360 | inet_rsk(req)->acked = 1; | |
7c657876 ACM |
361 | DCCP_INC_STATS(DCCP_MIB_OUTSEGS); |
362 | return skb; | |
363 | } | |
364 | ||
f21e68ca ACM |
365 | EXPORT_SYMBOL_GPL(dccp_make_response); |
366 | ||
017487d7 ACM |
367 | static struct sk_buff *dccp_make_reset(struct sock *sk, struct dst_entry *dst, |
368 | const enum dccp_reset_codes code) | |
7c657876 ACM |
369 | |
370 | { | |
371 | struct dccp_hdr *dh; | |
372 | struct dccp_sock *dp = dccp_sk(sk); | |
118b2c95 | 373 | const u32 dccp_header_size = sizeof(struct dccp_hdr) + |
7c657876 ACM |
374 | sizeof(struct dccp_hdr_ext) + |
375 | sizeof(struct dccp_hdr_reset); | |
118b2c95 | 376 | struct sk_buff *skb = sock_wmalloc(sk, sk->sk_prot->max_header, 1, |
7c657876 ACM |
377 | GFP_ATOMIC); |
378 | if (skb == NULL) | |
379 | return NULL; | |
380 | ||
381 | /* Reserve space for headers. */ | |
118b2c95 | 382 | skb_reserve(skb, sk->sk_prot->max_header); |
7c657876 ACM |
383 | |
384 | skb->dst = dst_clone(dst); | |
7c657876 ACM |
385 | |
386 | dccp_inc_seqno(&dp->dccps_gss); | |
387 | ||
388 | DCCP_SKB_CB(skb)->dccpd_reset_code = code; | |
389 | DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_RESET; | |
390 | DCCP_SKB_CB(skb)->dccpd_seq = dp->dccps_gss; | |
2d0817d1 ACM |
391 | |
392 | if (dccp_insert_options(sk, skb)) { | |
393 | kfree_skb(skb); | |
394 | return NULL; | |
395 | } | |
7c657876 | 396 | |
9b42078e | 397 | dh = dccp_zeroed_hdr(skb, dccp_header_size); |
7c657876 ACM |
398 | |
399 | dh->dccph_sport = inet_sk(sk)->sport; | |
400 | dh->dccph_dport = inet_sk(sk)->dport; | |
7690af3f ACM |
401 | dh->dccph_doff = (dccp_header_size + |
402 | DCCP_SKB_CB(skb)->dccpd_opt_len) / 4; | |
7c657876 ACM |
403 | dh->dccph_type = DCCP_PKT_RESET; |
404 | dh->dccph_x = 1; | |
405 | dccp_hdr_set_seq(dh, dp->dccps_gss); | |
406 | dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), dp->dccps_gsr); | |
407 | ||
408 | dccp_hdr_reset(skb)->dccph_reset_code = code; | |
6f4e5fff | 409 | inet_csk(sk)->icsk_af_ops->send_check(sk, 0, skb); |
7c657876 ACM |
410 | |
411 | DCCP_INC_STATS(DCCP_MIB_OUTSEGS); | |
412 | return skb; | |
413 | } | |
414 | ||
017487d7 ACM |
415 | int dccp_send_reset(struct sock *sk, enum dccp_reset_codes code) |
416 | { | |
417 | /* | |
418 | * FIXME: what if rebuild_header fails? | |
419 | * Should we be doing a rebuild_header here? | |
420 | */ | |
421 | int err = inet_sk_rebuild_header(sk); | |
422 | ||
423 | if (err == 0) { | |
424 | struct sk_buff *skb = dccp_make_reset(sk, sk->sk_dst_cache, | |
425 | code); | |
426 | if (skb != NULL) { | |
427 | memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); | |
93173112 | 428 | err = inet_csk(sk)->icsk_af_ops->queue_xmit(skb, sk, 0); |
017487d7 ACM |
429 | if (err == NET_XMIT_CN) |
430 | err = 0; | |
431 | } | |
432 | } | |
433 | ||
434 | return err; | |
435 | } | |
436 | ||
7c657876 ACM |
437 | /* |
438 | * Do all connect socket setups that can be done AF independent. | |
439 | */ | |
440 | static inline void dccp_connect_init(struct sock *sk) | |
441 | { | |
f21e68ca | 442 | struct dccp_sock *dp = dccp_sk(sk); |
7c657876 ACM |
443 | struct dst_entry *dst = __sk_dst_get(sk); |
444 | struct inet_connection_sock *icsk = inet_csk(sk); | |
445 | ||
446 | sk->sk_err = 0; | |
447 | sock_reset_flag(sk, SOCK_DONE); | |
448 | ||
449 | dccp_sync_mss(sk, dst_mtu(dst)); | |
450 | ||
f21e68ca ACM |
451 | /* |
452 | * SWL and AWL are initially adjusted so that they are not less than | |
453 | * the initial Sequence Numbers received and sent, respectively: | |
454 | * SWL := max(GSR + 1 - floor(W/4), ISR), | |
455 | * AWL := max(GSS - W' + 1, ISS). | |
456 | * These adjustments MUST be applied only at the beginning of the | |
457 | * connection. | |
458 | */ | |
d7f7365f | 459 | dccp_update_gss(sk, dp->dccps_iss); |
f21e68ca | 460 | dccp_set_seqno(&dp->dccps_awl, max48(dp->dccps_awl, dp->dccps_iss)); |
7c657876 | 461 | |
d7f7365f GR |
462 | /* S.GAR - greatest valid acknowledgement number received on a non-Sync; |
463 | * initialized to S.ISS (sec. 8.5) */ | |
464 | dp->dccps_gar = dp->dccps_iss; | |
465 | ||
7c657876 | 466 | icsk->icsk_retransmits = 0; |
97e5848d IM |
467 | init_timer(&dp->dccps_xmit_timer); |
468 | dp->dccps_xmit_timer.data = (unsigned long)sk; | |
469 | dp->dccps_xmit_timer.function = dccp_write_xmit_timer; | |
7c657876 ACM |
470 | } |
471 | ||
472 | int dccp_connect(struct sock *sk) | |
473 | { | |
474 | struct sk_buff *skb; | |
475 | struct inet_connection_sock *icsk = inet_csk(sk); | |
476 | ||
477 | dccp_connect_init(sk); | |
478 | ||
118b2c95 | 479 | skb = alloc_skb(sk->sk_prot->max_header, sk->sk_allocation); |
7c657876 ACM |
480 | if (unlikely(skb == NULL)) |
481 | return -ENOBUFS; | |
482 | ||
483 | /* Reserve space for headers. */ | |
118b2c95 | 484 | skb_reserve(skb, sk->sk_prot->max_header); |
7c657876 ACM |
485 | |
486 | DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_REQUEST; | |
7c657876 | 487 | |
48918a4d | 488 | dccp_skb_entail(sk, skb); |
7c657876 ACM |
489 | dccp_transmit_skb(sk, skb_clone(skb, GFP_KERNEL)); |
490 | DCCP_INC_STATS(DCCP_MIB_ACTIVEOPENS); | |
491 | ||
492 | /* Timer for repeating the REQUEST until an answer. */ | |
27258ee5 ACM |
493 | inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, |
494 | icsk->icsk_rto, DCCP_RTO_MAX); | |
7c657876 ACM |
495 | return 0; |
496 | } | |
497 | ||
f21e68ca ACM |
498 | EXPORT_SYMBOL_GPL(dccp_connect); |
499 | ||
7c657876 ACM |
500 | void dccp_send_ack(struct sock *sk) |
501 | { | |
502 | /* If we have been reset, we may not send again. */ | |
503 | if (sk->sk_state != DCCP_CLOSED) { | |
118b2c95 ACM |
504 | struct sk_buff *skb = alloc_skb(sk->sk_prot->max_header, |
505 | GFP_ATOMIC); | |
7c657876 ACM |
506 | |
507 | if (skb == NULL) { | |
508 | inet_csk_schedule_ack(sk); | |
509 | inet_csk(sk)->icsk_ack.ato = TCP_ATO_MIN; | |
7690af3f ACM |
510 | inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK, |
511 | TCP_DELACK_MAX, | |
512 | DCCP_RTO_MAX); | |
7c657876 ACM |
513 | return; |
514 | } | |
515 | ||
516 | /* Reserve space for headers */ | |
118b2c95 | 517 | skb_reserve(skb, sk->sk_prot->max_header); |
7c657876 | 518 | DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_ACK; |
7c657876 ACM |
519 | dccp_transmit_skb(sk, skb); |
520 | } | |
521 | } | |
522 | ||
523 | EXPORT_SYMBOL_GPL(dccp_send_ack); | |
524 | ||
525 | void dccp_send_delayed_ack(struct sock *sk) | |
526 | { | |
527 | struct inet_connection_sock *icsk = inet_csk(sk); | |
528 | /* | |
529 | * FIXME: tune this timer. elapsed time fixes the skew, so no problem | |
530 | * with using 2s, and active senders also piggyback the ACK into a | |
531 | * DATAACK packet, so this is really for quiescent senders. | |
532 | */ | |
533 | unsigned long timeout = jiffies + 2 * HZ; | |
534 | ||
535 | /* Use new timeout only if there wasn't a older one earlier. */ | |
536 | if (icsk->icsk_ack.pending & ICSK_ACK_TIMER) { | |
537 | /* If delack timer was blocked or is about to expire, | |
538 | * send ACK now. | |
539 | * | |
540 | * FIXME: check the "about to expire" part | |
541 | */ | |
542 | if (icsk->icsk_ack.blocked) { | |
543 | dccp_send_ack(sk); | |
544 | return; | |
545 | } | |
546 | ||
547 | if (!time_before(timeout, icsk->icsk_ack.timeout)) | |
548 | timeout = icsk->icsk_ack.timeout; | |
549 | } | |
550 | icsk->icsk_ack.pending |= ICSK_ACK_SCHED | ICSK_ACK_TIMER; | |
551 | icsk->icsk_ack.timeout = timeout; | |
552 | sk_reset_timer(sk, &icsk->icsk_delack_timer, timeout); | |
553 | } | |
554 | ||
e92ae93a ACM |
555 | void dccp_send_sync(struct sock *sk, const u64 seq, |
556 | const enum dccp_pkt_type pkt_type) | |
7c657876 ACM |
557 | { |
558 | /* | |
559 | * We are not putting this on the write queue, so | |
560 | * dccp_transmit_skb() will set the ownership to this | |
561 | * sock. | |
562 | */ | |
118b2c95 | 563 | struct sk_buff *skb = alloc_skb(sk->sk_prot->max_header, GFP_ATOMIC); |
7c657876 ACM |
564 | |
565 | if (skb == NULL) | |
566 | /* FIXME: how to make sure the sync is sent? */ | |
567 | return; | |
568 | ||
569 | /* Reserve space for headers and prepare control bits. */ | |
118b2c95 | 570 | skb_reserve(skb, sk->sk_prot->max_header); |
e92ae93a | 571 | DCCP_SKB_CB(skb)->dccpd_type = pkt_type; |
7c657876 ACM |
572 | DCCP_SKB_CB(skb)->dccpd_seq = seq; |
573 | ||
7c657876 ACM |
574 | dccp_transmit_skb(sk, skb); |
575 | } | |
576 | ||
b61fafc4 ACM |
577 | EXPORT_SYMBOL_GPL(dccp_send_sync); |
578 | ||
7690af3f ACM |
579 | /* |
580 | * Send a DCCP_PKT_CLOSE/CLOSEREQ. The caller locks the socket for us. This | |
581 | * cannot be allowed to fail queueing a DCCP_PKT_CLOSE/CLOSEREQ frame under | |
582 | * any circumstances. | |
7c657876 | 583 | */ |
7ad07e7c | 584 | void dccp_send_close(struct sock *sk, const int active) |
7c657876 ACM |
585 | { |
586 | struct dccp_sock *dp = dccp_sk(sk); | |
587 | struct sk_buff *skb; | |
7d877f3b | 588 | const gfp_t prio = active ? GFP_KERNEL : GFP_ATOMIC; |
7c657876 | 589 | |
7ad07e7c ACM |
590 | skb = alloc_skb(sk->sk_prot->max_header, prio); |
591 | if (skb == NULL) | |
592 | return; | |
7c657876 ACM |
593 | |
594 | /* Reserve space for headers and prepare control bits. */ | |
595 | skb_reserve(skb, sk->sk_prot->max_header); | |
7690af3f ACM |
596 | DCCP_SKB_CB(skb)->dccpd_type = dp->dccps_role == DCCP_ROLE_CLIENT ? |
597 | DCCP_PKT_CLOSE : DCCP_PKT_CLOSEREQ; | |
7c657876 | 598 | |
7ad07e7c | 599 | if (active) { |
97e5848d | 600 | dccp_write_xmit(sk, 1); |
48918a4d | 601 | dccp_skb_entail(sk, skb); |
7ad07e7c | 602 | dccp_transmit_skb(sk, skb_clone(skb, prio)); |
97e5848d | 603 | /* FIXME do we need a retransmit timer here? */ |
7ad07e7c ACM |
604 | } else |
605 | dccp_transmit_skb(sk, skb); | |
7c657876 | 606 | } |