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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 | ||
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 | ||
48918a4d HX |
29 | static inline void dccp_skb_entail(struct sock *sk, struct sk_buff *skb) |
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 */ | |
51 | const int dccp_header_size = sizeof(*dh) + | |
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 | |
7c657876 ACM |
66 | case DCCP_PKT_SYNC: |
67 | case DCCP_PKT_SYNCACK: | |
68 | ackno = dcb->dccpd_seq; | |
edc9e819 HX |
69 | /* fall through */ |
70 | default: | |
71 | /* | |
72 | * Only data packets should come through with skb->sk | |
73 | * set. | |
74 | */ | |
75 | WARN_ON(skb->sk); | |
76 | skb_set_owner_w(skb, sk); | |
7c657876 ACM |
77 | break; |
78 | } | |
24117727 ACM |
79 | |
80 | dcb->dccpd_seq = dp->dccps_gss; | |
81 | dccp_insert_options(sk, skb); | |
7c657876 ACM |
82 | |
83 | skb->h.raw = skb_push(skb, dccp_header_size); | |
84 | dh = dccp_hdr(skb); | |
fda0fd6c | 85 | |
7c657876 ACM |
86 | /* Build DCCP header and checksum it. */ |
87 | memset(dh, 0, dccp_header_size); | |
88 | dh->dccph_type = dcb->dccpd_type; | |
89 | dh->dccph_sport = inet->sport; | |
90 | dh->dccph_dport = inet->dport; | |
91 | dh->dccph_doff = (dccp_header_size + dcb->dccpd_opt_len) / 4; | |
92 | dh->dccph_ccval = dcb->dccpd_ccval; | |
93 | /* XXX For now we're using only 48 bits sequence numbers */ | |
94 | dh->dccph_x = 1; | |
95 | ||
96 | dp->dccps_awh = dp->dccps_gss; | |
97 | dccp_hdr_set_seq(dh, dp->dccps_gss); | |
98 | if (set_ack) | |
99 | dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), ackno); | |
100 | ||
101 | switch (dcb->dccpd_type) { | |
102 | case DCCP_PKT_REQUEST: | |
7690af3f | 103 | dccp_hdr_request(skb)->dccph_req_service = |
67e6b629 | 104 | dp->dccps_service; |
7c657876 ACM |
105 | break; |
106 | case DCCP_PKT_RESET: | |
7690af3f ACM |
107 | dccp_hdr_reset(skb)->dccph_reset_code = |
108 | dcb->dccpd_reset_code; | |
7c657876 ACM |
109 | break; |
110 | } | |
111 | ||
57cca05a | 112 | icsk->icsk_af_ops->send_check(sk, skb->len, skb); |
7c657876 | 113 | |
7ad07e7c | 114 | if (set_ack) |
7c657876 ACM |
115 | dccp_event_ack_sent(sk); |
116 | ||
117 | DCCP_INC_STATS(DCCP_MIB_OUTSEGS); | |
118 | ||
49c5bfaf | 119 | memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); |
57cca05a | 120 | err = icsk->icsk_af_ops->queue_xmit(skb, 0); |
7c657876 ACM |
121 | if (err <= 0) |
122 | return err; | |
123 | ||
124 | /* NET_XMIT_CN is special. It does not guarantee, | |
125 | * that this packet is lost. It tells that device | |
126 | * is about to start to drop packets or already | |
127 | * drops some packets of the same priority and | |
128 | * invokes us to send less aggressively. | |
129 | */ | |
130 | return err == NET_XMIT_CN ? 0 : err; | |
131 | } | |
132 | return -ENOBUFS; | |
133 | } | |
134 | ||
135 | unsigned int dccp_sync_mss(struct sock *sk, u32 pmtu) | |
136 | { | |
137 | struct dccp_sock *dp = dccp_sk(sk); | |
57cca05a ACM |
138 | int mss_now = (pmtu - inet_csk(sk)->icsk_af_ops->net_header_len - |
139 | sizeof(struct dccp_hdr) - sizeof(struct dccp_hdr_ext)); | |
7c657876 ACM |
140 | |
141 | /* Now subtract optional transport overhead */ | |
142 | mss_now -= dp->dccps_ext_header_len; | |
143 | ||
144 | /* | |
145 | * FIXME: this should come from the CCID infrastructure, where, say, | |
146 | * TFRC will say it wants TIMESTAMPS, ELAPSED time, etc, for now lets | |
147 | * put a rough estimate for NDP + TIMESTAMP + TIMESTAMP_ECHO + ELAPSED | |
148 | * TIME + TFRC_OPT_LOSS_EVENT_RATE + TFRC_OPT_RECEIVE_RATE + padding to | |
149 | * make it a multiple of 4 | |
150 | */ | |
151 | ||
152 | mss_now -= ((5 + 6 + 10 + 6 + 6 + 6 + 3) / 4) * 4; | |
153 | ||
154 | /* And store cached results */ | |
155 | dp->dccps_pmtu_cookie = pmtu; | |
156 | dp->dccps_mss_cache = mss_now; | |
157 | ||
158 | return mss_now; | |
159 | } | |
160 | ||
f21e68ca ACM |
161 | EXPORT_SYMBOL_GPL(dccp_sync_mss); |
162 | ||
c530cfb1 ACM |
163 | void dccp_write_space(struct sock *sk) |
164 | { | |
165 | read_lock(&sk->sk_callback_lock); | |
166 | ||
167 | if (sk->sk_sleep && waitqueue_active(sk->sk_sleep)) | |
168 | wake_up_interruptible(sk->sk_sleep); | |
169 | /* Should agree with poll, otherwise some programs break */ | |
170 | if (sock_writeable(sk)) | |
171 | sk_wake_async(sk, 2, POLL_OUT); | |
172 | ||
173 | read_unlock(&sk->sk_callback_lock); | |
174 | } | |
175 | ||
d6809c12 ACM |
176 | /** |
177 | * dccp_wait_for_ccid - Wait for ccid to tell us we can send a packet | |
178 | * @sk: socket to wait for | |
179 | * @timeo: for how long | |
180 | */ | |
181 | static int dccp_wait_for_ccid(struct sock *sk, struct sk_buff *skb, | |
182 | long *timeo) | |
183 | { | |
184 | struct dccp_sock *dp = dccp_sk(sk); | |
185 | DEFINE_WAIT(wait); | |
186 | long delay; | |
187 | int rc; | |
188 | ||
189 | while (1) { | |
190 | prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE); | |
191 | ||
192 | if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN)) | |
193 | goto do_error; | |
194 | if (!*timeo) | |
195 | goto do_nonblock; | |
196 | if (signal_pending(current)) | |
197 | goto do_interrupted; | |
198 | ||
199 | rc = ccid_hc_tx_send_packet(dp->dccps_hc_tx_ccid, sk, skb, | |
200 | skb->len); | |
201 | if (rc <= 0) | |
202 | break; | |
203 | delay = msecs_to_jiffies(rc); | |
204 | if (delay > *timeo || delay < 0) | |
205 | goto do_nonblock; | |
206 | ||
207 | sk->sk_write_pending++; | |
208 | release_sock(sk); | |
209 | *timeo -= schedule_timeout(delay); | |
210 | lock_sock(sk); | |
211 | sk->sk_write_pending--; | |
212 | } | |
213 | out: | |
214 | finish_wait(sk->sk_sleep, &wait); | |
215 | return rc; | |
216 | ||
217 | do_error: | |
218 | rc = -EPIPE; | |
219 | goto out; | |
220 | do_nonblock: | |
221 | rc = -EAGAIN; | |
222 | goto out; | |
223 | do_interrupted: | |
224 | rc = sock_intr_errno(*timeo); | |
225 | goto out; | |
226 | } | |
227 | ||
228 | int dccp_write_xmit(struct sock *sk, struct sk_buff *skb, long *timeo) | |
27258ee5 ACM |
229 | { |
230 | const struct dccp_sock *dp = dccp_sk(sk); | |
d6809c12 ACM |
231 | int err = ccid_hc_tx_send_packet(dp->dccps_hc_tx_ccid, sk, skb, |
232 | skb->len); | |
233 | ||
234 | if (err > 0) | |
235 | err = dccp_wait_for_ccid(sk, skb, timeo); | |
27258ee5 ACM |
236 | |
237 | if (err == 0) { | |
27258ee5 | 238 | struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb); |
d6809c12 | 239 | const int len = skb->len; |
27258ee5 ACM |
240 | |
241 | if (sk->sk_state == DCCP_PARTOPEN) { | |
242 | /* See 8.1.5. Handshake Completion */ | |
243 | inet_csk_schedule_ack(sk); | |
244 | inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK, | |
245 | inet_csk(sk)->icsk_rto, | |
246 | DCCP_RTO_MAX); | |
247 | dcb->dccpd_type = DCCP_PKT_DATAACK; | |
ae31c339 | 248 | } else if (dccp_ack_pending(sk)) |
27258ee5 ACM |
249 | dcb->dccpd_type = DCCP_PKT_DATAACK; |
250 | else | |
251 | dcb->dccpd_type = DCCP_PKT_DATA; | |
252 | ||
253 | err = dccp_transmit_skb(sk, skb); | |
254 | ccid_hc_tx_packet_sent(dp->dccps_hc_tx_ccid, sk, 0, len); | |
ffa29347 HX |
255 | } else |
256 | kfree_skb(skb); | |
27258ee5 ACM |
257 | |
258 | return err; | |
259 | } | |
260 | ||
7c657876 ACM |
261 | int dccp_retransmit_skb(struct sock *sk, struct sk_buff *skb) |
262 | { | |
57cca05a | 263 | if (inet_csk(sk)->icsk_af_ops->rebuild_header(sk) != 0) |
7c657876 ACM |
264 | return -EHOSTUNREACH; /* Routing failure or similar. */ |
265 | ||
266 | return dccp_transmit_skb(sk, (skb_cloned(skb) ? | |
267 | pskb_copy(skb, GFP_ATOMIC): | |
268 | skb_clone(skb, GFP_ATOMIC))); | |
269 | } | |
270 | ||
271 | struct sk_buff *dccp_make_response(struct sock *sk, struct dst_entry *dst, | |
272 | struct request_sock *req) | |
273 | { | |
274 | struct dccp_hdr *dh; | |
67e6b629 | 275 | struct dccp_request_sock *dreq; |
7c657876 ACM |
276 | const int dccp_header_size = sizeof(struct dccp_hdr) + |
277 | sizeof(struct dccp_hdr_ext) + | |
278 | sizeof(struct dccp_hdr_response); | |
279 | struct sk_buff *skb = sock_wmalloc(sk, MAX_HEADER + DCCP_MAX_OPT_LEN + | |
280 | dccp_header_size, 1, | |
281 | GFP_ATOMIC); | |
282 | if (skb == NULL) | |
283 | return NULL; | |
284 | ||
285 | /* Reserve space for headers. */ | |
286 | skb_reserve(skb, MAX_HEADER + DCCP_MAX_OPT_LEN + dccp_header_size); | |
287 | ||
288 | skb->dst = dst_clone(dst); | |
289 | skb->csum = 0; | |
290 | ||
67e6b629 | 291 | dreq = dccp_rsk(req); |
7c657876 | 292 | DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_RESPONSE; |
67e6b629 | 293 | DCCP_SKB_CB(skb)->dccpd_seq = dreq->dreq_iss; |
7c657876 ACM |
294 | dccp_insert_options(sk, skb); |
295 | ||
296 | skb->h.raw = skb_push(skb, dccp_header_size); | |
297 | ||
298 | dh = dccp_hdr(skb); | |
299 | memset(dh, 0, dccp_header_size); | |
300 | ||
301 | dh->dccph_sport = inet_sk(sk)->sport; | |
302 | dh->dccph_dport = inet_rsk(req)->rmt_port; | |
7690af3f ACM |
303 | dh->dccph_doff = (dccp_header_size + |
304 | DCCP_SKB_CB(skb)->dccpd_opt_len) / 4; | |
7c657876 ACM |
305 | dh->dccph_type = DCCP_PKT_RESPONSE; |
306 | dh->dccph_x = 1; | |
67e6b629 ACM |
307 | dccp_hdr_set_seq(dh, dreq->dreq_iss); |
308 | dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), dreq->dreq_isr); | |
309 | dccp_hdr_response(skb)->dccph_resp_service = dreq->dreq_service; | |
7c657876 | 310 | |
95b81ef7 YN |
311 | dh->dccph_checksum = dccp_v4_checksum(skb, inet_rsk(req)->loc_addr, |
312 | inet_rsk(req)->rmt_addr); | |
7c657876 ACM |
313 | |
314 | DCCP_INC_STATS(DCCP_MIB_OUTSEGS); | |
315 | return skb; | |
316 | } | |
317 | ||
f21e68ca ACM |
318 | EXPORT_SYMBOL_GPL(dccp_make_response); |
319 | ||
7c657876 ACM |
320 | struct sk_buff *dccp_make_reset(struct sock *sk, struct dst_entry *dst, |
321 | const enum dccp_reset_codes code) | |
322 | ||
323 | { | |
324 | struct dccp_hdr *dh; | |
325 | struct dccp_sock *dp = dccp_sk(sk); | |
326 | const int dccp_header_size = sizeof(struct dccp_hdr) + | |
327 | sizeof(struct dccp_hdr_ext) + | |
328 | sizeof(struct dccp_hdr_reset); | |
329 | struct sk_buff *skb = sock_wmalloc(sk, MAX_HEADER + DCCP_MAX_OPT_LEN + | |
330 | dccp_header_size, 1, | |
331 | GFP_ATOMIC); | |
332 | if (skb == NULL) | |
333 | return NULL; | |
334 | ||
335 | /* Reserve space for headers. */ | |
336 | skb_reserve(skb, MAX_HEADER + DCCP_MAX_OPT_LEN + dccp_header_size); | |
337 | ||
338 | skb->dst = dst_clone(dst); | |
339 | skb->csum = 0; | |
340 | ||
341 | dccp_inc_seqno(&dp->dccps_gss); | |
342 | ||
343 | DCCP_SKB_CB(skb)->dccpd_reset_code = code; | |
344 | DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_RESET; | |
345 | DCCP_SKB_CB(skb)->dccpd_seq = dp->dccps_gss; | |
346 | dccp_insert_options(sk, skb); | |
347 | ||
348 | skb->h.raw = skb_push(skb, dccp_header_size); | |
349 | ||
350 | dh = dccp_hdr(skb); | |
351 | memset(dh, 0, dccp_header_size); | |
352 | ||
353 | dh->dccph_sport = inet_sk(sk)->sport; | |
354 | dh->dccph_dport = inet_sk(sk)->dport; | |
7690af3f ACM |
355 | dh->dccph_doff = (dccp_header_size + |
356 | DCCP_SKB_CB(skb)->dccpd_opt_len) / 4; | |
7c657876 ACM |
357 | dh->dccph_type = DCCP_PKT_RESET; |
358 | dh->dccph_x = 1; | |
359 | dccp_hdr_set_seq(dh, dp->dccps_gss); | |
360 | dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), dp->dccps_gsr); | |
361 | ||
362 | dccp_hdr_reset(skb)->dccph_reset_code = code; | |
363 | ||
95b81ef7 YN |
364 | dh->dccph_checksum = dccp_v4_checksum(skb, inet_sk(sk)->saddr, |
365 | inet_sk(sk)->daddr); | |
7c657876 ACM |
366 | |
367 | DCCP_INC_STATS(DCCP_MIB_OUTSEGS); | |
368 | return skb; | |
369 | } | |
370 | ||
371 | /* | |
372 | * Do all connect socket setups that can be done AF independent. | |
373 | */ | |
374 | static inline void dccp_connect_init(struct sock *sk) | |
375 | { | |
f21e68ca | 376 | struct dccp_sock *dp = dccp_sk(sk); |
7c657876 ACM |
377 | struct dst_entry *dst = __sk_dst_get(sk); |
378 | struct inet_connection_sock *icsk = inet_csk(sk); | |
379 | ||
380 | sk->sk_err = 0; | |
381 | sock_reset_flag(sk, SOCK_DONE); | |
382 | ||
383 | dccp_sync_mss(sk, dst_mtu(dst)); | |
384 | ||
f21e68ca ACM |
385 | dccp_update_gss(sk, dp->dccps_iss); |
386 | /* | |
387 | * SWL and AWL are initially adjusted so that they are not less than | |
388 | * the initial Sequence Numbers received and sent, respectively: | |
389 | * SWL := max(GSR + 1 - floor(W/4), ISR), | |
390 | * AWL := max(GSS - W' + 1, ISS). | |
391 | * These adjustments MUST be applied only at the beginning of the | |
392 | * connection. | |
393 | */ | |
394 | dccp_set_seqno(&dp->dccps_awl, max48(dp->dccps_awl, dp->dccps_iss)); | |
7c657876 ACM |
395 | |
396 | icsk->icsk_retransmits = 0; | |
397 | } | |
398 | ||
399 | int dccp_connect(struct sock *sk) | |
400 | { | |
401 | struct sk_buff *skb; | |
402 | struct inet_connection_sock *icsk = inet_csk(sk); | |
403 | ||
404 | dccp_connect_init(sk); | |
405 | ||
406 | skb = alloc_skb(MAX_DCCP_HEADER + 15, sk->sk_allocation); | |
407 | if (unlikely(skb == NULL)) | |
408 | return -ENOBUFS; | |
409 | ||
410 | /* Reserve space for headers. */ | |
411 | skb_reserve(skb, MAX_DCCP_HEADER); | |
412 | ||
413 | DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_REQUEST; | |
7c657876 | 414 | skb->csum = 0; |
7c657876 | 415 | |
48918a4d | 416 | dccp_skb_entail(sk, skb); |
7c657876 ACM |
417 | dccp_transmit_skb(sk, skb_clone(skb, GFP_KERNEL)); |
418 | DCCP_INC_STATS(DCCP_MIB_ACTIVEOPENS); | |
419 | ||
420 | /* Timer for repeating the REQUEST until an answer. */ | |
27258ee5 ACM |
421 | inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, |
422 | icsk->icsk_rto, DCCP_RTO_MAX); | |
7c657876 ACM |
423 | return 0; |
424 | } | |
425 | ||
f21e68ca ACM |
426 | EXPORT_SYMBOL_GPL(dccp_connect); |
427 | ||
7c657876 ACM |
428 | void dccp_send_ack(struct sock *sk) |
429 | { | |
430 | /* If we have been reset, we may not send again. */ | |
431 | if (sk->sk_state != DCCP_CLOSED) { | |
432 | struct sk_buff *skb = alloc_skb(MAX_DCCP_HEADER, GFP_ATOMIC); | |
433 | ||
434 | if (skb == NULL) { | |
435 | inet_csk_schedule_ack(sk); | |
436 | inet_csk(sk)->icsk_ack.ato = TCP_ATO_MIN; | |
7690af3f ACM |
437 | inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK, |
438 | TCP_DELACK_MAX, | |
439 | DCCP_RTO_MAX); | |
7c657876 ACM |
440 | return; |
441 | } | |
442 | ||
443 | /* Reserve space for headers */ | |
444 | skb_reserve(skb, MAX_DCCP_HEADER); | |
445 | skb->csum = 0; | |
446 | DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_ACK; | |
7c657876 ACM |
447 | dccp_transmit_skb(sk, skb); |
448 | } | |
449 | } | |
450 | ||
451 | EXPORT_SYMBOL_GPL(dccp_send_ack); | |
452 | ||
453 | void dccp_send_delayed_ack(struct sock *sk) | |
454 | { | |
455 | struct inet_connection_sock *icsk = inet_csk(sk); | |
456 | /* | |
457 | * FIXME: tune this timer. elapsed time fixes the skew, so no problem | |
458 | * with using 2s, and active senders also piggyback the ACK into a | |
459 | * DATAACK packet, so this is really for quiescent senders. | |
460 | */ | |
461 | unsigned long timeout = jiffies + 2 * HZ; | |
462 | ||
463 | /* Use new timeout only if there wasn't a older one earlier. */ | |
464 | if (icsk->icsk_ack.pending & ICSK_ACK_TIMER) { | |
465 | /* If delack timer was blocked or is about to expire, | |
466 | * send ACK now. | |
467 | * | |
468 | * FIXME: check the "about to expire" part | |
469 | */ | |
470 | if (icsk->icsk_ack.blocked) { | |
471 | dccp_send_ack(sk); | |
472 | return; | |
473 | } | |
474 | ||
475 | if (!time_before(timeout, icsk->icsk_ack.timeout)) | |
476 | timeout = icsk->icsk_ack.timeout; | |
477 | } | |
478 | icsk->icsk_ack.pending |= ICSK_ACK_SCHED | ICSK_ACK_TIMER; | |
479 | icsk->icsk_ack.timeout = timeout; | |
480 | sk_reset_timer(sk, &icsk->icsk_delack_timer, timeout); | |
481 | } | |
482 | ||
e92ae93a ACM |
483 | void dccp_send_sync(struct sock *sk, const u64 seq, |
484 | const enum dccp_pkt_type pkt_type) | |
7c657876 ACM |
485 | { |
486 | /* | |
487 | * We are not putting this on the write queue, so | |
488 | * dccp_transmit_skb() will set the ownership to this | |
489 | * sock. | |
490 | */ | |
491 | struct sk_buff *skb = alloc_skb(MAX_DCCP_HEADER, GFP_ATOMIC); | |
492 | ||
493 | if (skb == NULL) | |
494 | /* FIXME: how to make sure the sync is sent? */ | |
495 | return; | |
496 | ||
497 | /* Reserve space for headers and prepare control bits. */ | |
498 | skb_reserve(skb, MAX_DCCP_HEADER); | |
499 | skb->csum = 0; | |
e92ae93a | 500 | DCCP_SKB_CB(skb)->dccpd_type = pkt_type; |
7c657876 ACM |
501 | DCCP_SKB_CB(skb)->dccpd_seq = seq; |
502 | ||
7c657876 ACM |
503 | dccp_transmit_skb(sk, skb); |
504 | } | |
505 | ||
7690af3f ACM |
506 | /* |
507 | * Send a DCCP_PKT_CLOSE/CLOSEREQ. The caller locks the socket for us. This | |
508 | * cannot be allowed to fail queueing a DCCP_PKT_CLOSE/CLOSEREQ frame under | |
509 | * any circumstances. | |
7c657876 | 510 | */ |
7ad07e7c | 511 | void dccp_send_close(struct sock *sk, const int active) |
7c657876 ACM |
512 | { |
513 | struct dccp_sock *dp = dccp_sk(sk); | |
514 | struct sk_buff *skb; | |
7d877f3b | 515 | const gfp_t prio = active ? GFP_KERNEL : GFP_ATOMIC; |
7c657876 | 516 | |
7ad07e7c ACM |
517 | skb = alloc_skb(sk->sk_prot->max_header, prio); |
518 | if (skb == NULL) | |
519 | return; | |
7c657876 ACM |
520 | |
521 | /* Reserve space for headers and prepare control bits. */ | |
522 | skb_reserve(skb, sk->sk_prot->max_header); | |
523 | skb->csum = 0; | |
7690af3f ACM |
524 | DCCP_SKB_CB(skb)->dccpd_type = dp->dccps_role == DCCP_ROLE_CLIENT ? |
525 | DCCP_PKT_CLOSE : DCCP_PKT_CLOSEREQ; | |
7c657876 | 526 | |
7ad07e7c | 527 | if (active) { |
48918a4d | 528 | dccp_skb_entail(sk, skb); |
7ad07e7c ACM |
529 | dccp_transmit_skb(sk, skb_clone(skb, prio)); |
530 | } else | |
531 | dccp_transmit_skb(sk, skb); | |
7c657876 | 532 | } |