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); | |
46 | struct dccp_sock *dp = dccp_sk(sk); | |
47 | struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb); | |
48 | struct dccp_hdr *dh; | |
49 | /* XXX For now we're using only 48 bits sequence numbers */ | |
50 | const int dccp_header_size = sizeof(*dh) + | |
51 | sizeof(struct dccp_hdr_ext) + | |
7690af3f | 52 | dccp_packet_hdr_len(dcb->dccpd_type); |
7c657876 ACM |
53 | int err, set_ack = 1; |
54 | u64 ackno = dp->dccps_gsr; | |
55 | ||
7c657876 ACM |
56 | dccp_inc_seqno(&dp->dccps_gss); |
57 | ||
7c657876 ACM |
58 | switch (dcb->dccpd_type) { |
59 | case DCCP_PKT_DATA: | |
60 | set_ack = 0; | |
edc9e819 HX |
61 | /* fall through */ |
62 | case DCCP_PKT_DATAACK: | |
7c657876 | 63 | break; |
edc9e819 | 64 | |
7c657876 ACM |
65 | case DCCP_PKT_SYNC: |
66 | case DCCP_PKT_SYNCACK: | |
67 | ackno = dcb->dccpd_seq; | |
edc9e819 HX |
68 | /* fall through */ |
69 | default: | |
70 | /* | |
71 | * Only data packets should come through with skb->sk | |
72 | * set. | |
73 | */ | |
74 | WARN_ON(skb->sk); | |
75 | skb_set_owner_w(skb, sk); | |
7c657876 ACM |
76 | break; |
77 | } | |
24117727 ACM |
78 | |
79 | dcb->dccpd_seq = dp->dccps_gss; | |
80 | dccp_insert_options(sk, skb); | |
7c657876 ACM |
81 | |
82 | skb->h.raw = skb_push(skb, dccp_header_size); | |
83 | dh = dccp_hdr(skb); | |
fda0fd6c | 84 | |
7c657876 ACM |
85 | /* Build DCCP header and checksum it. */ |
86 | memset(dh, 0, dccp_header_size); | |
87 | dh->dccph_type = dcb->dccpd_type; | |
88 | dh->dccph_sport = inet->sport; | |
89 | dh->dccph_dport = inet->dport; | |
90 | dh->dccph_doff = (dccp_header_size + dcb->dccpd_opt_len) / 4; | |
91 | dh->dccph_ccval = dcb->dccpd_ccval; | |
92 | /* XXX For now we're using only 48 bits sequence numbers */ | |
93 | dh->dccph_x = 1; | |
94 | ||
95 | dp->dccps_awh = dp->dccps_gss; | |
96 | dccp_hdr_set_seq(dh, dp->dccps_gss); | |
97 | if (set_ack) | |
98 | dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), ackno); | |
99 | ||
100 | switch (dcb->dccpd_type) { | |
101 | case DCCP_PKT_REQUEST: | |
7690af3f | 102 | dccp_hdr_request(skb)->dccph_req_service = |
67e6b629 | 103 | dp->dccps_service; |
7c657876 ACM |
104 | break; |
105 | case DCCP_PKT_RESET: | |
7690af3f ACM |
106 | dccp_hdr_reset(skb)->dccph_reset_code = |
107 | dcb->dccpd_reset_code; | |
7c657876 ACM |
108 | break; |
109 | } | |
110 | ||
95b81ef7 YN |
111 | dh->dccph_checksum = dccp_v4_checksum(skb, inet->saddr, |
112 | inet->daddr); | |
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)); |
7c657876 ACM |
120 | err = ip_queue_xmit(skb, 0); |
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); | |
138 | int mss_now; | |
139 | ||
140 | /* | |
7690af3f ACM |
141 | * FIXME: we really should be using the af_specific thing to support |
142 | * IPv6. | |
143 | * mss_now = pmtu - tp->af_specific->net_header_len - | |
144 | * sizeof(struct dccp_hdr) - sizeof(struct dccp_hdr_ext); | |
7c657876 | 145 | */ |
7690af3f ACM |
146 | mss_now = pmtu - sizeof(struct iphdr) - sizeof(struct dccp_hdr) - |
147 | sizeof(struct dccp_hdr_ext); | |
7c657876 ACM |
148 | |
149 | /* Now subtract optional transport overhead */ | |
150 | mss_now -= dp->dccps_ext_header_len; | |
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 */ | |
163 | dp->dccps_pmtu_cookie = pmtu; | |
164 | dp->dccps_mss_cache = mss_now; | |
165 | ||
166 | return mss_now; | |
167 | } | |
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 | { | |
269 | if (inet_sk_rebuild_header(sk) != 0) | |
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; |
7c657876 ACM |
282 | const int dccp_header_size = sizeof(struct dccp_hdr) + |
283 | sizeof(struct dccp_hdr_ext) + | |
284 | sizeof(struct dccp_hdr_response); | |
285 | struct sk_buff *skb = sock_wmalloc(sk, MAX_HEADER + DCCP_MAX_OPT_LEN + | |
286 | dccp_header_size, 1, | |
287 | GFP_ATOMIC); | |
288 | if (skb == NULL) | |
289 | return NULL; | |
290 | ||
291 | /* Reserve space for headers. */ | |
292 | skb_reserve(skb, MAX_HEADER + DCCP_MAX_OPT_LEN + dccp_header_size); | |
293 | ||
294 | skb->dst = dst_clone(dst); | |
295 | skb->csum = 0; | |
296 | ||
67e6b629 | 297 | dreq = dccp_rsk(req); |
7c657876 | 298 | DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_RESPONSE; |
67e6b629 | 299 | DCCP_SKB_CB(skb)->dccpd_seq = dreq->dreq_iss; |
7c657876 ACM |
300 | dccp_insert_options(sk, skb); |
301 | ||
302 | skb->h.raw = skb_push(skb, dccp_header_size); | |
303 | ||
304 | dh = dccp_hdr(skb); | |
305 | memset(dh, 0, dccp_header_size); | |
306 | ||
307 | dh->dccph_sport = inet_sk(sk)->sport; | |
308 | dh->dccph_dport = inet_rsk(req)->rmt_port; | |
7690af3f ACM |
309 | dh->dccph_doff = (dccp_header_size + |
310 | DCCP_SKB_CB(skb)->dccpd_opt_len) / 4; | |
7c657876 ACM |
311 | dh->dccph_type = DCCP_PKT_RESPONSE; |
312 | dh->dccph_x = 1; | |
67e6b629 ACM |
313 | dccp_hdr_set_seq(dh, dreq->dreq_iss); |
314 | dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), dreq->dreq_isr); | |
315 | dccp_hdr_response(skb)->dccph_resp_service = dreq->dreq_service; | |
7c657876 | 316 | |
95b81ef7 YN |
317 | dh->dccph_checksum = dccp_v4_checksum(skb, inet_rsk(req)->loc_addr, |
318 | inet_rsk(req)->rmt_addr); | |
7c657876 ACM |
319 | |
320 | DCCP_INC_STATS(DCCP_MIB_OUTSEGS); | |
321 | return skb; | |
322 | } | |
323 | ||
324 | struct sk_buff *dccp_make_reset(struct sock *sk, struct dst_entry *dst, | |
325 | const enum dccp_reset_codes code) | |
326 | ||
327 | { | |
328 | struct dccp_hdr *dh; | |
329 | struct dccp_sock *dp = dccp_sk(sk); | |
330 | const int dccp_header_size = sizeof(struct dccp_hdr) + | |
331 | sizeof(struct dccp_hdr_ext) + | |
332 | sizeof(struct dccp_hdr_reset); | |
333 | struct sk_buff *skb = sock_wmalloc(sk, MAX_HEADER + DCCP_MAX_OPT_LEN + | |
334 | dccp_header_size, 1, | |
335 | GFP_ATOMIC); | |
336 | if (skb == NULL) | |
337 | return NULL; | |
338 | ||
339 | /* Reserve space for headers. */ | |
340 | skb_reserve(skb, MAX_HEADER + DCCP_MAX_OPT_LEN + dccp_header_size); | |
341 | ||
342 | skb->dst = dst_clone(dst); | |
343 | skb->csum = 0; | |
344 | ||
345 | dccp_inc_seqno(&dp->dccps_gss); | |
346 | ||
347 | DCCP_SKB_CB(skb)->dccpd_reset_code = code; | |
348 | DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_RESET; | |
349 | DCCP_SKB_CB(skb)->dccpd_seq = dp->dccps_gss; | |
350 | dccp_insert_options(sk, skb); | |
351 | ||
352 | skb->h.raw = skb_push(skb, dccp_header_size); | |
353 | ||
354 | dh = dccp_hdr(skb); | |
355 | memset(dh, 0, dccp_header_size); | |
356 | ||
357 | dh->dccph_sport = inet_sk(sk)->sport; | |
358 | dh->dccph_dport = inet_sk(sk)->dport; | |
7690af3f ACM |
359 | dh->dccph_doff = (dccp_header_size + |
360 | DCCP_SKB_CB(skb)->dccpd_opt_len) / 4; | |
7c657876 ACM |
361 | dh->dccph_type = DCCP_PKT_RESET; |
362 | dh->dccph_x = 1; | |
363 | dccp_hdr_set_seq(dh, dp->dccps_gss); | |
364 | dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), dp->dccps_gsr); | |
365 | ||
366 | dccp_hdr_reset(skb)->dccph_reset_code = code; | |
367 | ||
95b81ef7 YN |
368 | dh->dccph_checksum = dccp_v4_checksum(skb, inet_sk(sk)->saddr, |
369 | inet_sk(sk)->daddr); | |
7c657876 ACM |
370 | |
371 | DCCP_INC_STATS(DCCP_MIB_OUTSEGS); | |
372 | return skb; | |
373 | } | |
374 | ||
375 | /* | |
376 | * Do all connect socket setups that can be done AF independent. | |
377 | */ | |
378 | static inline void dccp_connect_init(struct sock *sk) | |
379 | { | |
380 | struct dst_entry *dst = __sk_dst_get(sk); | |
381 | struct inet_connection_sock *icsk = inet_csk(sk); | |
382 | ||
383 | sk->sk_err = 0; | |
384 | sock_reset_flag(sk, SOCK_DONE); | |
385 | ||
386 | dccp_sync_mss(sk, dst_mtu(dst)); | |
387 | ||
388 | /* | |
389 | * FIXME: set dp->{dccps_swh,dccps_swl}, with | |
390 | * something like dccp_inc_seq | |
391 | */ | |
392 | ||
393 | icsk->icsk_retransmits = 0; | |
394 | } | |
395 | ||
396 | int dccp_connect(struct sock *sk) | |
397 | { | |
398 | struct sk_buff *skb; | |
399 | struct inet_connection_sock *icsk = inet_csk(sk); | |
400 | ||
401 | dccp_connect_init(sk); | |
402 | ||
403 | skb = alloc_skb(MAX_DCCP_HEADER + 15, sk->sk_allocation); | |
404 | if (unlikely(skb == NULL)) | |
405 | return -ENOBUFS; | |
406 | ||
407 | /* Reserve space for headers. */ | |
408 | skb_reserve(skb, MAX_DCCP_HEADER); | |
409 | ||
410 | DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_REQUEST; | |
7c657876 | 411 | skb->csum = 0; |
7c657876 | 412 | |
48918a4d | 413 | dccp_skb_entail(sk, skb); |
7c657876 ACM |
414 | dccp_transmit_skb(sk, skb_clone(skb, GFP_KERNEL)); |
415 | DCCP_INC_STATS(DCCP_MIB_ACTIVEOPENS); | |
416 | ||
417 | /* Timer for repeating the REQUEST until an answer. */ | |
27258ee5 ACM |
418 | inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, |
419 | icsk->icsk_rto, DCCP_RTO_MAX); | |
7c657876 ACM |
420 | return 0; |
421 | } | |
422 | ||
423 | void dccp_send_ack(struct sock *sk) | |
424 | { | |
425 | /* If we have been reset, we may not send again. */ | |
426 | if (sk->sk_state != DCCP_CLOSED) { | |
427 | struct sk_buff *skb = alloc_skb(MAX_DCCP_HEADER, GFP_ATOMIC); | |
428 | ||
429 | if (skb == NULL) { | |
430 | inet_csk_schedule_ack(sk); | |
431 | inet_csk(sk)->icsk_ack.ato = TCP_ATO_MIN; | |
7690af3f ACM |
432 | inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK, |
433 | TCP_DELACK_MAX, | |
434 | DCCP_RTO_MAX); | |
7c657876 ACM |
435 | return; |
436 | } | |
437 | ||
438 | /* Reserve space for headers */ | |
439 | skb_reserve(skb, MAX_DCCP_HEADER); | |
440 | skb->csum = 0; | |
441 | DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_ACK; | |
7c657876 ACM |
442 | dccp_transmit_skb(sk, skb); |
443 | } | |
444 | } | |
445 | ||
446 | EXPORT_SYMBOL_GPL(dccp_send_ack); | |
447 | ||
448 | void dccp_send_delayed_ack(struct sock *sk) | |
449 | { | |
450 | struct inet_connection_sock *icsk = inet_csk(sk); | |
451 | /* | |
452 | * FIXME: tune this timer. elapsed time fixes the skew, so no problem | |
453 | * with using 2s, and active senders also piggyback the ACK into a | |
454 | * DATAACK packet, so this is really for quiescent senders. | |
455 | */ | |
456 | unsigned long timeout = jiffies + 2 * HZ; | |
457 | ||
458 | /* Use new timeout only if there wasn't a older one earlier. */ | |
459 | if (icsk->icsk_ack.pending & ICSK_ACK_TIMER) { | |
460 | /* If delack timer was blocked or is about to expire, | |
461 | * send ACK now. | |
462 | * | |
463 | * FIXME: check the "about to expire" part | |
464 | */ | |
465 | if (icsk->icsk_ack.blocked) { | |
466 | dccp_send_ack(sk); | |
467 | return; | |
468 | } | |
469 | ||
470 | if (!time_before(timeout, icsk->icsk_ack.timeout)) | |
471 | timeout = icsk->icsk_ack.timeout; | |
472 | } | |
473 | icsk->icsk_ack.pending |= ICSK_ACK_SCHED | ICSK_ACK_TIMER; | |
474 | icsk->icsk_ack.timeout = timeout; | |
475 | sk_reset_timer(sk, &icsk->icsk_delack_timer, timeout); | |
476 | } | |
477 | ||
e92ae93a ACM |
478 | void dccp_send_sync(struct sock *sk, const u64 seq, |
479 | const enum dccp_pkt_type pkt_type) | |
7c657876 ACM |
480 | { |
481 | /* | |
482 | * We are not putting this on the write queue, so | |
483 | * dccp_transmit_skb() will set the ownership to this | |
484 | * sock. | |
485 | */ | |
486 | struct sk_buff *skb = alloc_skb(MAX_DCCP_HEADER, GFP_ATOMIC); | |
487 | ||
488 | if (skb == NULL) | |
489 | /* FIXME: how to make sure the sync is sent? */ | |
490 | return; | |
491 | ||
492 | /* Reserve space for headers and prepare control bits. */ | |
493 | skb_reserve(skb, MAX_DCCP_HEADER); | |
494 | skb->csum = 0; | |
e92ae93a | 495 | DCCP_SKB_CB(skb)->dccpd_type = pkt_type; |
7c657876 ACM |
496 | DCCP_SKB_CB(skb)->dccpd_seq = seq; |
497 | ||
7c657876 ACM |
498 | dccp_transmit_skb(sk, skb); |
499 | } | |
500 | ||
7690af3f ACM |
501 | /* |
502 | * Send a DCCP_PKT_CLOSE/CLOSEREQ. The caller locks the socket for us. This | |
503 | * cannot be allowed to fail queueing a DCCP_PKT_CLOSE/CLOSEREQ frame under | |
504 | * any circumstances. | |
7c657876 | 505 | */ |
7ad07e7c | 506 | void dccp_send_close(struct sock *sk, const int active) |
7c657876 ACM |
507 | { |
508 | struct dccp_sock *dp = dccp_sk(sk); | |
509 | struct sk_buff *skb; | |
7d877f3b | 510 | const gfp_t prio = active ? GFP_KERNEL : GFP_ATOMIC; |
7c657876 | 511 | |
7ad07e7c ACM |
512 | skb = alloc_skb(sk->sk_prot->max_header, prio); |
513 | if (skb == NULL) | |
514 | return; | |
7c657876 ACM |
515 | |
516 | /* Reserve space for headers and prepare control bits. */ | |
517 | skb_reserve(skb, sk->sk_prot->max_header); | |
518 | skb->csum = 0; | |
7690af3f ACM |
519 | DCCP_SKB_CB(skb)->dccpd_type = dp->dccps_role == DCCP_ROLE_CLIENT ? |
520 | DCCP_PKT_CLOSE : DCCP_PKT_CLOSEREQ; | |
7c657876 | 521 | |
7ad07e7c | 522 | if (active) { |
48918a4d | 523 | dccp_skb_entail(sk, skb); |
7ad07e7c ACM |
524 | dccp_transmit_skb(sk, skb_clone(skb, prio)); |
525 | } else | |
526 | dccp_transmit_skb(sk, skb); | |
7c657876 | 527 | } |