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Commit | Line | Data |
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7c657876 ACM |
1 | /* |
2 | * net/dccp/output.c | |
8109b02b | 3 | * |
7c657876 ACM |
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 | } | |
c9eaf173 | 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)); |
e89862f4 | 127 | err = icsk->icsk_af_ops->queue_xmit(skb, 0); |
b9df3cb8 | 128 | return net_xmit_eval(err); |
7c657876 ACM |
129 | } |
130 | return -ENOBUFS; | |
131 | } | |
132 | ||
133 | unsigned int dccp_sync_mss(struct sock *sk, u32 pmtu) | |
134 | { | |
d83d8461 | 135 | struct inet_connection_sock *icsk = inet_csk(sk); |
7c657876 | 136 | struct dccp_sock *dp = dccp_sk(sk); |
d83d8461 | 137 | int mss_now = (pmtu - icsk->icsk_af_ops->net_header_len - |
57cca05a | 138 | sizeof(struct dccp_hdr) - sizeof(struct dccp_hdr_ext)); |
7c657876 ACM |
139 | |
140 | /* Now subtract optional transport overhead */ | |
d83d8461 | 141 | mss_now -= icsk->icsk_ext_hdr_len; |
7c657876 ACM |
142 | |
143 | /* | |
144 | * FIXME: this should come from the CCID infrastructure, where, say, | |
145 | * TFRC will say it wants TIMESTAMPS, ELAPSED time, etc, for now lets | |
146 | * put a rough estimate for NDP + TIMESTAMP + TIMESTAMP_ECHO + ELAPSED | |
147 | * TIME + TFRC_OPT_LOSS_EVENT_RATE + TFRC_OPT_RECEIVE_RATE + padding to | |
148 | * make it a multiple of 4 | |
149 | */ | |
150 | ||
151 | mss_now -= ((5 + 6 + 10 + 6 + 6 + 6 + 3) / 4) * 4; | |
152 | ||
153 | /* And store cached results */ | |
d83d8461 | 154 | icsk->icsk_pmtu_cookie = pmtu; |
7c657876 ACM |
155 | dp->dccps_mss_cache = mss_now; |
156 | ||
157 | return mss_now; | |
158 | } | |
159 | ||
f21e68ca ACM |
160 | EXPORT_SYMBOL_GPL(dccp_sync_mss); |
161 | ||
c530cfb1 ACM |
162 | void dccp_write_space(struct sock *sk) |
163 | { | |
164 | read_lock(&sk->sk_callback_lock); | |
165 | ||
166 | if (sk->sk_sleep && waitqueue_active(sk->sk_sleep)) | |
167 | wake_up_interruptible(sk->sk_sleep); | |
168 | /* Should agree with poll, otherwise some programs break */ | |
169 | if (sock_writeable(sk)) | |
170 | sk_wake_async(sk, 2, POLL_OUT); | |
171 | ||
172 | read_unlock(&sk->sk_callback_lock); | |
173 | } | |
174 | ||
d6809c12 ACM |
175 | /** |
176 | * dccp_wait_for_ccid - Wait for ccid to tell us we can send a packet | |
177 | * @sk: socket to wait for | |
d6809c12 | 178 | */ |
5cc3741d | 179 | static int dccp_wait_for_ccid(struct sock *sk, struct sk_buff *skb) |
d6809c12 ACM |
180 | { |
181 | struct dccp_sock *dp = dccp_sk(sk); | |
182 | DEFINE_WAIT(wait); | |
5cc3741d | 183 | unsigned long delay; |
d6809c12 ACM |
184 | int rc; |
185 | ||
186 | while (1) { | |
187 | prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE); | |
188 | ||
97e5848d | 189 | if (sk->sk_err) |
d6809c12 | 190 | goto do_error; |
d6809c12 ACM |
191 | if (signal_pending(current)) |
192 | goto do_interrupted; | |
193 | ||
6b57c93d | 194 | rc = ccid_hc_tx_send_packet(dp->dccps_hc_tx_ccid, sk, skb); |
d6809c12 ACM |
195 | if (rc <= 0) |
196 | break; | |
197 | delay = msecs_to_jiffies(rc); | |
d6809c12 ACM |
198 | sk->sk_write_pending++; |
199 | release_sock(sk); | |
5cc3741d | 200 | schedule_timeout(delay); |
d6809c12 ACM |
201 | lock_sock(sk); |
202 | sk->sk_write_pending--; | |
203 | } | |
204 | out: | |
205 | finish_wait(sk->sk_sleep, &wait); | |
206 | return rc; | |
207 | ||
208 | do_error: | |
209 | rc = -EPIPE; | |
210 | goto out; | |
d6809c12 | 211 | do_interrupted: |
5cc3741d | 212 | rc = -EINTR; |
d6809c12 ACM |
213 | goto out; |
214 | } | |
215 | ||
97e5848d | 216 | void dccp_write_xmit(struct sock *sk, int block) |
27258ee5 | 217 | { |
97e5848d IM |
218 | struct dccp_sock *dp = dccp_sk(sk); |
219 | struct sk_buff *skb; | |
97e5848d IM |
220 | |
221 | while ((skb = skb_peek(&sk->sk_write_queue))) { | |
6b57c93d | 222 | int err = ccid_hc_tx_send_packet(dp->dccps_hc_tx_ccid, sk, skb); |
d6809c12 | 223 | |
97e5848d IM |
224 | if (err > 0) { |
225 | if (!block) { | |
226 | sk_reset_timer(sk, &dp->dccps_xmit_timer, | |
227 | msecs_to_jiffies(err)+jiffies); | |
228 | break; | |
5cc3741d IM |
229 | } else |
230 | err = dccp_wait_for_ccid(sk, skb); | |
f6282f4d | 231 | if (err && err != -EINTR) |
59348b19 | 232 | DCCP_BUG("err=%d after dccp_wait_for_ccid", err); |
97e5848d | 233 | } |
27258ee5 | 234 | |
97e5848d IM |
235 | skb_dequeue(&sk->sk_write_queue); |
236 | if (err == 0) { | |
237 | struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb); | |
238 | const int len = skb->len; | |
27258ee5 | 239 | |
97e5848d IM |
240 | if (sk->sk_state == DCCP_PARTOPEN) { |
241 | /* See 8.1.5. Handshake Completion */ | |
242 | inet_csk_schedule_ack(sk); | |
243 | inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK, | |
27258ee5 ACM |
244 | inet_csk(sk)->icsk_rto, |
245 | DCCP_RTO_MAX); | |
97e5848d IM |
246 | dcb->dccpd_type = DCCP_PKT_DATAACK; |
247 | } else if (dccp_ack_pending(sk)) | |
248 | dcb->dccpd_type = DCCP_PKT_DATAACK; | |
249 | else | |
250 | dcb->dccpd_type = DCCP_PKT_DATA; | |
251 | ||
252 | err = dccp_transmit_skb(sk, skb); | |
253 | ccid_hc_tx_packet_sent(dp->dccps_hc_tx_ccid, sk, 0, len); | |
59348b19 GR |
254 | if (err) |
255 | DCCP_BUG("err=%d after ccid_hc_tx_packet_sent", | |
256 | err); | |
f6282f4d GR |
257 | } else { |
258 | dccp_pr_debug("packet discarded\n"); | |
b08d5840 | 259 | kfree_skb(skb); |
f6282f4d | 260 | } |
97e5848d | 261 | } |
27258ee5 ACM |
262 | } |
263 | ||
7c657876 ACM |
264 | int dccp_retransmit_skb(struct sock *sk, struct sk_buff *skb) |
265 | { | |
57cca05a | 266 | if (inet_csk(sk)->icsk_af_ops->rebuild_header(sk) != 0) |
7c657876 ACM |
267 | return -EHOSTUNREACH; /* Routing failure or similar. */ |
268 | ||
269 | return dccp_transmit_skb(sk, (skb_cloned(skb) ? | |
270 | pskb_copy(skb, GFP_ATOMIC): | |
271 | skb_clone(skb, GFP_ATOMIC))); | |
272 | } | |
273 | ||
274 | struct sk_buff *dccp_make_response(struct sock *sk, struct dst_entry *dst, | |
275 | struct request_sock *req) | |
276 | { | |
277 | struct dccp_hdr *dh; | |
67e6b629 | 278 | struct dccp_request_sock *dreq; |
118b2c95 | 279 | const u32 dccp_header_size = sizeof(struct dccp_hdr) + |
7c657876 ACM |
280 | sizeof(struct dccp_hdr_ext) + |
281 | sizeof(struct dccp_hdr_response); | |
118b2c95 | 282 | struct sk_buff *skb = sock_wmalloc(sk, sk->sk_prot->max_header, 1, |
7c657876 ACM |
283 | GFP_ATOMIC); |
284 | if (skb == NULL) | |
285 | return NULL; | |
286 | ||
287 | /* Reserve space for headers. */ | |
118b2c95 | 288 | skb_reserve(skb, sk->sk_prot->max_header); |
7c657876 ACM |
289 | |
290 | skb->dst = dst_clone(dst); | |
7c657876 | 291 | |
67e6b629 | 292 | dreq = dccp_rsk(req); |
e11d9d30 GR |
293 | if (inet_rsk(req)->acked) /* increase ISS upon retransmission */ |
294 | dccp_inc_seqno(&dreq->dreq_iss); | |
7c657876 | 295 | DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_RESPONSE; |
67e6b629 | 296 | DCCP_SKB_CB(skb)->dccpd_seq = dreq->dreq_iss; |
2d0817d1 ACM |
297 | |
298 | if (dccp_insert_options(sk, skb)) { | |
299 | kfree_skb(skb); | |
300 | return NULL; | |
301 | } | |
7c657876 | 302 | |
09dbc389 | 303 | /* Build and checksum header */ |
9b42078e | 304 | dh = dccp_zeroed_hdr(skb, dccp_header_size); |
7c657876 ACM |
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 | |
6f4e5fff GR |
316 | dccp_csum_outgoing(skb); |
317 | ||
e11d9d30 GR |
318 | /* We use `acked' to remember that a Response was already sent. */ |
319 | inet_rsk(req)->acked = 1; | |
7c657876 ACM |
320 | DCCP_INC_STATS(DCCP_MIB_OUTSEGS); |
321 | return skb; | |
322 | } | |
323 | ||
f21e68ca ACM |
324 | EXPORT_SYMBOL_GPL(dccp_make_response); |
325 | ||
017487d7 ACM |
326 | static struct sk_buff *dccp_make_reset(struct sock *sk, struct dst_entry *dst, |
327 | const enum dccp_reset_codes code) | |
7c657876 ACM |
328 | { |
329 | struct dccp_hdr *dh; | |
330 | struct dccp_sock *dp = dccp_sk(sk); | |
118b2c95 | 331 | const u32 dccp_header_size = sizeof(struct dccp_hdr) + |
7c657876 ACM |
332 | sizeof(struct dccp_hdr_ext) + |
333 | sizeof(struct dccp_hdr_reset); | |
118b2c95 | 334 | struct sk_buff *skb = sock_wmalloc(sk, sk->sk_prot->max_header, 1, |
7c657876 ACM |
335 | GFP_ATOMIC); |
336 | if (skb == NULL) | |
337 | return NULL; | |
338 | ||
339 | /* Reserve space for headers. */ | |
118b2c95 | 340 | skb_reserve(skb, sk->sk_prot->max_header); |
7c657876 ACM |
341 | |
342 | skb->dst = dst_clone(dst); | |
7c657876 ACM |
343 | |
344 | dccp_inc_seqno(&dp->dccps_gss); | |
345 | ||
346 | DCCP_SKB_CB(skb)->dccpd_reset_code = code; | |
347 | DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_RESET; | |
348 | DCCP_SKB_CB(skb)->dccpd_seq = dp->dccps_gss; | |
2d0817d1 ACM |
349 | |
350 | if (dccp_insert_options(sk, skb)) { | |
351 | kfree_skb(skb); | |
352 | return NULL; | |
353 | } | |
7c657876 | 354 | |
9b42078e | 355 | dh = dccp_zeroed_hdr(skb, dccp_header_size); |
7c657876 ACM |
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; | |
6f4e5fff | 367 | inet_csk(sk)->icsk_af_ops->send_check(sk, 0, skb); |
7c657876 ACM |
368 | |
369 | DCCP_INC_STATS(DCCP_MIB_OUTSEGS); | |
370 | return skb; | |
371 | } | |
372 | ||
017487d7 ACM |
373 | int dccp_send_reset(struct sock *sk, enum dccp_reset_codes code) |
374 | { | |
375 | /* | |
376 | * FIXME: what if rebuild_header fails? | |
377 | * Should we be doing a rebuild_header here? | |
378 | */ | |
379 | int err = inet_sk_rebuild_header(sk); | |
380 | ||
381 | if (err == 0) { | |
382 | struct sk_buff *skb = dccp_make_reset(sk, sk->sk_dst_cache, | |
383 | code); | |
384 | if (skb != NULL) { | |
385 | memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); | |
e89862f4 | 386 | err = inet_csk(sk)->icsk_af_ops->queue_xmit(skb, 0); |
b9df3cb8 | 387 | return net_xmit_eval(err); |
017487d7 ACM |
388 | } |
389 | } | |
390 | ||
391 | return err; | |
392 | } | |
393 | ||
7c657876 ACM |
394 | /* |
395 | * Do all connect socket setups that can be done AF independent. | |
396 | */ | |
397 | static inline void dccp_connect_init(struct sock *sk) | |
398 | { | |
f21e68ca | 399 | struct dccp_sock *dp = dccp_sk(sk); |
7c657876 ACM |
400 | struct dst_entry *dst = __sk_dst_get(sk); |
401 | struct inet_connection_sock *icsk = inet_csk(sk); | |
402 | ||
403 | sk->sk_err = 0; | |
404 | sock_reset_flag(sk, SOCK_DONE); | |
c9eaf173 | 405 | |
7c657876 ACM |
406 | dccp_sync_mss(sk, dst_mtu(dst)); |
407 | ||
8109b02b | 408 | /* |
f21e68ca ACM |
409 | * SWL and AWL are initially adjusted so that they are not less than |
410 | * the initial Sequence Numbers received and sent, respectively: | |
411 | * SWL := max(GSR + 1 - floor(W/4), ISR), | |
412 | * AWL := max(GSS - W' + 1, ISS). | |
413 | * These adjustments MUST be applied only at the beginning of the | |
414 | * connection. | |
8109b02b | 415 | */ |
d7f7365f | 416 | dccp_update_gss(sk, dp->dccps_iss); |
f21e68ca | 417 | dccp_set_seqno(&dp->dccps_awl, max48(dp->dccps_awl, dp->dccps_iss)); |
7c657876 | 418 | |
d7f7365f GR |
419 | /* S.GAR - greatest valid acknowledgement number received on a non-Sync; |
420 | * initialized to S.ISS (sec. 8.5) */ | |
421 | dp->dccps_gar = dp->dccps_iss; | |
422 | ||
7c657876 ACM |
423 | icsk->icsk_retransmits = 0; |
424 | } | |
425 | ||
426 | int dccp_connect(struct sock *sk) | |
427 | { | |
428 | struct sk_buff *skb; | |
429 | struct inet_connection_sock *icsk = inet_csk(sk); | |
430 | ||
431 | dccp_connect_init(sk); | |
432 | ||
118b2c95 | 433 | skb = alloc_skb(sk->sk_prot->max_header, sk->sk_allocation); |
7c657876 ACM |
434 | if (unlikely(skb == NULL)) |
435 | return -ENOBUFS; | |
436 | ||
437 | /* Reserve space for headers. */ | |
118b2c95 | 438 | skb_reserve(skb, sk->sk_prot->max_header); |
7c657876 ACM |
439 | |
440 | DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_REQUEST; | |
7c657876 | 441 | |
48918a4d | 442 | dccp_skb_entail(sk, skb); |
7c657876 ACM |
443 | dccp_transmit_skb(sk, skb_clone(skb, GFP_KERNEL)); |
444 | DCCP_INC_STATS(DCCP_MIB_ACTIVEOPENS); | |
445 | ||
446 | /* Timer for repeating the REQUEST until an answer. */ | |
27258ee5 ACM |
447 | inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, |
448 | icsk->icsk_rto, DCCP_RTO_MAX); | |
7c657876 ACM |
449 | return 0; |
450 | } | |
451 | ||
f21e68ca ACM |
452 | EXPORT_SYMBOL_GPL(dccp_connect); |
453 | ||
7c657876 ACM |
454 | void dccp_send_ack(struct sock *sk) |
455 | { | |
456 | /* If we have been reset, we may not send again. */ | |
457 | if (sk->sk_state != DCCP_CLOSED) { | |
118b2c95 ACM |
458 | struct sk_buff *skb = alloc_skb(sk->sk_prot->max_header, |
459 | GFP_ATOMIC); | |
7c657876 ACM |
460 | |
461 | if (skb == NULL) { | |
462 | inet_csk_schedule_ack(sk); | |
463 | inet_csk(sk)->icsk_ack.ato = TCP_ATO_MIN; | |
7690af3f ACM |
464 | inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK, |
465 | TCP_DELACK_MAX, | |
466 | DCCP_RTO_MAX); | |
7c657876 ACM |
467 | return; |
468 | } | |
469 | ||
470 | /* Reserve space for headers */ | |
118b2c95 | 471 | skb_reserve(skb, sk->sk_prot->max_header); |
7c657876 | 472 | DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_ACK; |
7c657876 ACM |
473 | dccp_transmit_skb(sk, skb); |
474 | } | |
475 | } | |
476 | ||
477 | EXPORT_SYMBOL_GPL(dccp_send_ack); | |
478 | ||
479 | void dccp_send_delayed_ack(struct sock *sk) | |
480 | { | |
481 | struct inet_connection_sock *icsk = inet_csk(sk); | |
482 | /* | |
483 | * FIXME: tune this timer. elapsed time fixes the skew, so no problem | |
484 | * with using 2s, and active senders also piggyback the ACK into a | |
485 | * DATAACK packet, so this is really for quiescent senders. | |
486 | */ | |
487 | unsigned long timeout = jiffies + 2 * HZ; | |
488 | ||
489 | /* Use new timeout only if there wasn't a older one earlier. */ | |
490 | if (icsk->icsk_ack.pending & ICSK_ACK_TIMER) { | |
491 | /* If delack timer was blocked or is about to expire, | |
492 | * send ACK now. | |
493 | * | |
494 | * FIXME: check the "about to expire" part | |
495 | */ | |
496 | if (icsk->icsk_ack.blocked) { | |
497 | dccp_send_ack(sk); | |
498 | return; | |
499 | } | |
500 | ||
501 | if (!time_before(timeout, icsk->icsk_ack.timeout)) | |
502 | timeout = icsk->icsk_ack.timeout; | |
503 | } | |
504 | icsk->icsk_ack.pending |= ICSK_ACK_SCHED | ICSK_ACK_TIMER; | |
505 | icsk->icsk_ack.timeout = timeout; | |
506 | sk_reset_timer(sk, &icsk->icsk_delack_timer, timeout); | |
507 | } | |
508 | ||
e92ae93a ACM |
509 | void dccp_send_sync(struct sock *sk, const u64 seq, |
510 | const enum dccp_pkt_type pkt_type) | |
7c657876 ACM |
511 | { |
512 | /* | |
513 | * We are not putting this on the write queue, so | |
514 | * dccp_transmit_skb() will set the ownership to this | |
515 | * sock. | |
516 | */ | |
118b2c95 | 517 | struct sk_buff *skb = alloc_skb(sk->sk_prot->max_header, GFP_ATOMIC); |
7c657876 ACM |
518 | |
519 | if (skb == NULL) | |
520 | /* FIXME: how to make sure the sync is sent? */ | |
521 | return; | |
522 | ||
523 | /* Reserve space for headers and prepare control bits. */ | |
118b2c95 | 524 | skb_reserve(skb, sk->sk_prot->max_header); |
e92ae93a | 525 | DCCP_SKB_CB(skb)->dccpd_type = pkt_type; |
7c657876 ACM |
526 | DCCP_SKB_CB(skb)->dccpd_seq = seq; |
527 | ||
7c657876 ACM |
528 | dccp_transmit_skb(sk, skb); |
529 | } | |
530 | ||
b61fafc4 ACM |
531 | EXPORT_SYMBOL_GPL(dccp_send_sync); |
532 | ||
7690af3f ACM |
533 | /* |
534 | * Send a DCCP_PKT_CLOSE/CLOSEREQ. The caller locks the socket for us. This | |
535 | * cannot be allowed to fail queueing a DCCP_PKT_CLOSE/CLOSEREQ frame under | |
536 | * any circumstances. | |
7c657876 | 537 | */ |
7ad07e7c | 538 | void dccp_send_close(struct sock *sk, const int active) |
7c657876 ACM |
539 | { |
540 | struct dccp_sock *dp = dccp_sk(sk); | |
541 | struct sk_buff *skb; | |
7d877f3b | 542 | const gfp_t prio = active ? GFP_KERNEL : GFP_ATOMIC; |
7c657876 | 543 | |
7ad07e7c ACM |
544 | skb = alloc_skb(sk->sk_prot->max_header, prio); |
545 | if (skb == NULL) | |
546 | return; | |
7c657876 ACM |
547 | |
548 | /* Reserve space for headers and prepare control bits. */ | |
549 | skb_reserve(skb, sk->sk_prot->max_header); | |
7690af3f ACM |
550 | DCCP_SKB_CB(skb)->dccpd_type = dp->dccps_role == DCCP_ROLE_CLIENT ? |
551 | DCCP_PKT_CLOSE : DCCP_PKT_CLOSEREQ; | |
7c657876 | 552 | |
7ad07e7c | 553 | if (active) { |
97e5848d | 554 | dccp_write_xmit(sk, 1); |
48918a4d | 555 | dccp_skb_entail(sk, skb); |
7ad07e7c | 556 | dccp_transmit_skb(sk, skb_clone(skb, prio)); |
97e5848d | 557 | /* FIXME do we need a retransmit timer here? */ |
7ad07e7c ACM |
558 | } else |
559 | dccp_transmit_skb(sk, skb); | |
7c657876 | 560 | } |