Commit | Line | Data |
---|---|---|
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: | |
b0d045ca | 72 | ackno = dcb->dccpd_ack_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; | |
6626e362 | 197 | dccp_pr_debug("delayed send by %d msec\n", rc); |
d6809c12 | 198 | delay = msecs_to_jiffies(rc); |
d6809c12 ACM |
199 | sk->sk_write_pending++; |
200 | release_sock(sk); | |
5cc3741d | 201 | schedule_timeout(delay); |
d6809c12 ACM |
202 | lock_sock(sk); |
203 | sk->sk_write_pending--; | |
204 | } | |
205 | out: | |
206 | finish_wait(sk->sk_sleep, &wait); | |
207 | return rc; | |
208 | ||
209 | do_error: | |
210 | rc = -EPIPE; | |
211 | goto out; | |
d6809c12 | 212 | do_interrupted: |
5cc3741d | 213 | rc = -EINTR; |
d6809c12 ACM |
214 | goto out; |
215 | } | |
216 | ||
97e5848d | 217 | void dccp_write_xmit(struct sock *sk, int block) |
27258ee5 | 218 | { |
97e5848d IM |
219 | struct dccp_sock *dp = dccp_sk(sk); |
220 | struct sk_buff *skb; | |
97e5848d IM |
221 | |
222 | while ((skb = skb_peek(&sk->sk_write_queue))) { | |
6b57c93d | 223 | int err = ccid_hc_tx_send_packet(dp->dccps_hc_tx_ccid, sk, skb); |
d6809c12 | 224 | |
97e5848d IM |
225 | if (err > 0) { |
226 | if (!block) { | |
227 | sk_reset_timer(sk, &dp->dccps_xmit_timer, | |
228 | msecs_to_jiffies(err)+jiffies); | |
229 | break; | |
5cc3741d IM |
230 | } else |
231 | err = dccp_wait_for_ccid(sk, skb); | |
f6282f4d | 232 | if (err && err != -EINTR) |
59348b19 | 233 | DCCP_BUG("err=%d after dccp_wait_for_ccid", err); |
97e5848d | 234 | } |
27258ee5 | 235 | |
97e5848d IM |
236 | skb_dequeue(&sk->sk_write_queue); |
237 | if (err == 0) { | |
238 | struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb); | |
239 | const int len = skb->len; | |
27258ee5 | 240 | |
97e5848d IM |
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, | |
27258ee5 ACM |
245 | inet_csk(sk)->icsk_rto, |
246 | DCCP_RTO_MAX); | |
97e5848d IM |
247 | dcb->dccpd_type = DCCP_PKT_DATAACK; |
248 | } else if (dccp_ack_pending(sk)) | |
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); | |
59348b19 GR |
255 | if (err) |
256 | DCCP_BUG("err=%d after ccid_hc_tx_packet_sent", | |
257 | err); | |
f6282f4d | 258 | } else { |
6626e362 | 259 | dccp_pr_debug("packet discarded due to err=%d\n", err); |
b08d5840 | 260 | kfree_skb(skb); |
f6282f4d | 261 | } |
97e5848d | 262 | } |
27258ee5 ACM |
263 | } |
264 | ||
7c657876 ACM |
265 | int dccp_retransmit_skb(struct sock *sk, struct sk_buff *skb) |
266 | { | |
57cca05a | 267 | if (inet_csk(sk)->icsk_af_ops->rebuild_header(sk) != 0) |
7c657876 ACM |
268 | return -EHOSTUNREACH; /* Routing failure or similar. */ |
269 | ||
270 | return dccp_transmit_skb(sk, (skb_cloned(skb) ? | |
271 | pskb_copy(skb, GFP_ATOMIC): | |
272 | skb_clone(skb, GFP_ATOMIC))); | |
273 | } | |
274 | ||
275 | struct sk_buff *dccp_make_response(struct sock *sk, struct dst_entry *dst, | |
276 | struct request_sock *req) | |
277 | { | |
278 | struct dccp_hdr *dh; | |
67e6b629 | 279 | struct dccp_request_sock *dreq; |
118b2c95 | 280 | const u32 dccp_header_size = sizeof(struct dccp_hdr) + |
7c657876 ACM |
281 | sizeof(struct dccp_hdr_ext) + |
282 | sizeof(struct dccp_hdr_response); | |
118b2c95 | 283 | struct sk_buff *skb = sock_wmalloc(sk, sk->sk_prot->max_header, 1, |
7c657876 ACM |
284 | GFP_ATOMIC); |
285 | if (skb == NULL) | |
286 | return NULL; | |
287 | ||
288 | /* Reserve space for headers. */ | |
118b2c95 | 289 | skb_reserve(skb, sk->sk_prot->max_header); |
7c657876 ACM |
290 | |
291 | skb->dst = dst_clone(dst); | |
7c657876 | 292 | |
67e6b629 | 293 | dreq = dccp_rsk(req); |
e11d9d30 GR |
294 | if (inet_rsk(req)->acked) /* increase ISS upon retransmission */ |
295 | dccp_inc_seqno(&dreq->dreq_iss); | |
7c657876 | 296 | DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_RESPONSE; |
67e6b629 | 297 | DCCP_SKB_CB(skb)->dccpd_seq = dreq->dreq_iss; |
2d0817d1 ACM |
298 | |
299 | if (dccp_insert_options(sk, skb)) { | |
300 | kfree_skb(skb); | |
301 | return NULL; | |
302 | } | |
7c657876 | 303 | |
09dbc389 | 304 | /* Build and checksum header */ |
9b42078e | 305 | dh = dccp_zeroed_hdr(skb, dccp_header_size); |
7c657876 ACM |
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 | |
6f4e5fff GR |
317 | dccp_csum_outgoing(skb); |
318 | ||
e11d9d30 GR |
319 | /* We use `acked' to remember that a Response was already sent. */ |
320 | inet_rsk(req)->acked = 1; | |
7c657876 ACM |
321 | DCCP_INC_STATS(DCCP_MIB_OUTSEGS); |
322 | return skb; | |
323 | } | |
324 | ||
f21e68ca ACM |
325 | EXPORT_SYMBOL_GPL(dccp_make_response); |
326 | ||
017487d7 ACM |
327 | static struct sk_buff *dccp_make_reset(struct sock *sk, struct dst_entry *dst, |
328 | const enum dccp_reset_codes code) | |
7c657876 ACM |
329 | { |
330 | struct dccp_hdr *dh; | |
331 | struct dccp_sock *dp = dccp_sk(sk); | |
118b2c95 | 332 | const u32 dccp_header_size = sizeof(struct dccp_hdr) + |
7c657876 ACM |
333 | sizeof(struct dccp_hdr_ext) + |
334 | sizeof(struct dccp_hdr_reset); | |
118b2c95 | 335 | struct sk_buff *skb = sock_wmalloc(sk, sk->sk_prot->max_header, 1, |
7c657876 ACM |
336 | GFP_ATOMIC); |
337 | if (skb == NULL) | |
338 | return NULL; | |
339 | ||
340 | /* Reserve space for headers. */ | |
118b2c95 | 341 | skb_reserve(skb, sk->sk_prot->max_header); |
7c657876 ACM |
342 | |
343 | skb->dst = dst_clone(dst); | |
7c657876 ACM |
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; | |
2d0817d1 ACM |
350 | |
351 | if (dccp_insert_options(sk, skb)) { | |
352 | kfree_skb(skb); | |
353 | return NULL; | |
354 | } | |
7c657876 | 355 | |
9b42078e | 356 | dh = dccp_zeroed_hdr(skb, dccp_header_size); |
7c657876 ACM |
357 | |
358 | dh->dccph_sport = inet_sk(sk)->sport; | |
359 | dh->dccph_dport = inet_sk(sk)->dport; | |
7690af3f ACM |
360 | dh->dccph_doff = (dccp_header_size + |
361 | DCCP_SKB_CB(skb)->dccpd_opt_len) / 4; | |
7c657876 ACM |
362 | dh->dccph_type = DCCP_PKT_RESET; |
363 | dh->dccph_x = 1; | |
364 | dccp_hdr_set_seq(dh, dp->dccps_gss); | |
365 | dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), dp->dccps_gsr); | |
366 | ||
367 | dccp_hdr_reset(skb)->dccph_reset_code = code; | |
6f4e5fff | 368 | inet_csk(sk)->icsk_af_ops->send_check(sk, 0, skb); |
7c657876 ACM |
369 | |
370 | DCCP_INC_STATS(DCCP_MIB_OUTSEGS); | |
371 | return skb; | |
372 | } | |
373 | ||
017487d7 ACM |
374 | int dccp_send_reset(struct sock *sk, enum dccp_reset_codes code) |
375 | { | |
376 | /* | |
377 | * FIXME: what if rebuild_header fails? | |
378 | * Should we be doing a rebuild_header here? | |
379 | */ | |
380 | int err = inet_sk_rebuild_header(sk); | |
381 | ||
382 | if (err == 0) { | |
383 | struct sk_buff *skb = dccp_make_reset(sk, sk->sk_dst_cache, | |
384 | code); | |
385 | if (skb != NULL) { | |
386 | memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); | |
e89862f4 | 387 | err = inet_csk(sk)->icsk_af_ops->queue_xmit(skb, 0); |
b9df3cb8 | 388 | return net_xmit_eval(err); |
017487d7 ACM |
389 | } |
390 | } | |
391 | ||
392 | return err; | |
393 | } | |
394 | ||
7c657876 ACM |
395 | /* |
396 | * Do all connect socket setups that can be done AF independent. | |
397 | */ | |
398 | static inline void dccp_connect_init(struct sock *sk) | |
399 | { | |
f21e68ca | 400 | struct dccp_sock *dp = dccp_sk(sk); |
7c657876 ACM |
401 | struct dst_entry *dst = __sk_dst_get(sk); |
402 | struct inet_connection_sock *icsk = inet_csk(sk); | |
403 | ||
404 | sk->sk_err = 0; | |
405 | sock_reset_flag(sk, SOCK_DONE); | |
c9eaf173 | 406 | |
7c657876 ACM |
407 | dccp_sync_mss(sk, dst_mtu(dst)); |
408 | ||
8109b02b | 409 | /* |
f21e68ca ACM |
410 | * SWL and AWL are initially adjusted so that they are not less than |
411 | * the initial Sequence Numbers received and sent, respectively: | |
412 | * SWL := max(GSR + 1 - floor(W/4), ISR), | |
413 | * AWL := max(GSS - W' + 1, ISS). | |
414 | * These adjustments MUST be applied only at the beginning of the | |
415 | * connection. | |
8109b02b | 416 | */ |
d7f7365f | 417 | dccp_update_gss(sk, dp->dccps_iss); |
f21e68ca | 418 | dccp_set_seqno(&dp->dccps_awl, max48(dp->dccps_awl, dp->dccps_iss)); |
7c657876 | 419 | |
d7f7365f GR |
420 | /* S.GAR - greatest valid acknowledgement number received on a non-Sync; |
421 | * initialized to S.ISS (sec. 8.5) */ | |
422 | dp->dccps_gar = dp->dccps_iss; | |
423 | ||
7c657876 ACM |
424 | icsk->icsk_retransmits = 0; |
425 | } | |
426 | ||
427 | int dccp_connect(struct sock *sk) | |
428 | { | |
429 | struct sk_buff *skb; | |
430 | struct inet_connection_sock *icsk = inet_csk(sk); | |
431 | ||
432 | dccp_connect_init(sk); | |
433 | ||
118b2c95 | 434 | skb = alloc_skb(sk->sk_prot->max_header, sk->sk_allocation); |
7c657876 ACM |
435 | if (unlikely(skb == NULL)) |
436 | return -ENOBUFS; | |
437 | ||
438 | /* Reserve space for headers. */ | |
118b2c95 | 439 | skb_reserve(skb, sk->sk_prot->max_header); |
7c657876 ACM |
440 | |
441 | DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_REQUEST; | |
7c657876 | 442 | |
48918a4d | 443 | dccp_skb_entail(sk, skb); |
7c657876 ACM |
444 | dccp_transmit_skb(sk, skb_clone(skb, GFP_KERNEL)); |
445 | DCCP_INC_STATS(DCCP_MIB_ACTIVEOPENS); | |
446 | ||
447 | /* Timer for repeating the REQUEST until an answer. */ | |
27258ee5 ACM |
448 | inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, |
449 | icsk->icsk_rto, DCCP_RTO_MAX); | |
7c657876 ACM |
450 | return 0; |
451 | } | |
452 | ||
f21e68ca ACM |
453 | EXPORT_SYMBOL_GPL(dccp_connect); |
454 | ||
7c657876 ACM |
455 | void dccp_send_ack(struct sock *sk) |
456 | { | |
457 | /* If we have been reset, we may not send again. */ | |
458 | if (sk->sk_state != DCCP_CLOSED) { | |
118b2c95 ACM |
459 | struct sk_buff *skb = alloc_skb(sk->sk_prot->max_header, |
460 | GFP_ATOMIC); | |
7c657876 ACM |
461 | |
462 | if (skb == NULL) { | |
463 | inet_csk_schedule_ack(sk); | |
464 | inet_csk(sk)->icsk_ack.ato = TCP_ATO_MIN; | |
7690af3f ACM |
465 | inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK, |
466 | TCP_DELACK_MAX, | |
467 | DCCP_RTO_MAX); | |
7c657876 ACM |
468 | return; |
469 | } | |
470 | ||
471 | /* Reserve space for headers */ | |
118b2c95 | 472 | skb_reserve(skb, sk->sk_prot->max_header); |
7c657876 | 473 | DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_ACK; |
7c657876 ACM |
474 | dccp_transmit_skb(sk, skb); |
475 | } | |
476 | } | |
477 | ||
478 | EXPORT_SYMBOL_GPL(dccp_send_ack); | |
479 | ||
727ecc5f | 480 | /* FIXME: Is this still necessary (11.3) - currently nowhere used by DCCP. */ |
7c657876 ACM |
481 | void dccp_send_delayed_ack(struct sock *sk) |
482 | { | |
483 | struct inet_connection_sock *icsk = inet_csk(sk); | |
484 | /* | |
485 | * FIXME: tune this timer. elapsed time fixes the skew, so no problem | |
486 | * with using 2s, and active senders also piggyback the ACK into a | |
487 | * DATAACK packet, so this is really for quiescent senders. | |
488 | */ | |
489 | unsigned long timeout = jiffies + 2 * HZ; | |
490 | ||
491 | /* Use new timeout only if there wasn't a older one earlier. */ | |
492 | if (icsk->icsk_ack.pending & ICSK_ACK_TIMER) { | |
493 | /* If delack timer was blocked or is about to expire, | |
494 | * send ACK now. | |
495 | * | |
496 | * FIXME: check the "about to expire" part | |
497 | */ | |
498 | if (icsk->icsk_ack.blocked) { | |
499 | dccp_send_ack(sk); | |
500 | return; | |
501 | } | |
502 | ||
503 | if (!time_before(timeout, icsk->icsk_ack.timeout)) | |
504 | timeout = icsk->icsk_ack.timeout; | |
505 | } | |
506 | icsk->icsk_ack.pending |= ICSK_ACK_SCHED | ICSK_ACK_TIMER; | |
507 | icsk->icsk_ack.timeout = timeout; | |
508 | sk_reset_timer(sk, &icsk->icsk_delack_timer, timeout); | |
509 | } | |
510 | ||
b0d045ca | 511 | void dccp_send_sync(struct sock *sk, const u64 ackno, |
e92ae93a | 512 | const enum dccp_pkt_type pkt_type) |
7c657876 ACM |
513 | { |
514 | /* | |
515 | * We are not putting this on the write queue, so | |
516 | * dccp_transmit_skb() will set the ownership to this | |
517 | * sock. | |
518 | */ | |
118b2c95 | 519 | struct sk_buff *skb = alloc_skb(sk->sk_prot->max_header, GFP_ATOMIC); |
7c657876 | 520 | |
b0d045ca | 521 | if (skb == NULL) { |
7c657876 | 522 | /* FIXME: how to make sure the sync is sent? */ |
b0d045ca | 523 | DCCP_CRIT("could not send %s", dccp_packet_name(pkt_type)); |
7c657876 | 524 | return; |
b0d045ca | 525 | } |
7c657876 ACM |
526 | |
527 | /* Reserve space for headers and prepare control bits. */ | |
118b2c95 | 528 | skb_reserve(skb, sk->sk_prot->max_header); |
e92ae93a | 529 | DCCP_SKB_CB(skb)->dccpd_type = pkt_type; |
b0d045ca | 530 | DCCP_SKB_CB(skb)->dccpd_ack_seq = ackno; |
7c657876 | 531 | |
7c657876 ACM |
532 | dccp_transmit_skb(sk, skb); |
533 | } | |
534 | ||
b61fafc4 ACM |
535 | EXPORT_SYMBOL_GPL(dccp_send_sync); |
536 | ||
7690af3f ACM |
537 | /* |
538 | * Send a DCCP_PKT_CLOSE/CLOSEREQ. The caller locks the socket for us. This | |
539 | * cannot be allowed to fail queueing a DCCP_PKT_CLOSE/CLOSEREQ frame under | |
540 | * any circumstances. | |
7c657876 | 541 | */ |
7ad07e7c | 542 | void dccp_send_close(struct sock *sk, const int active) |
7c657876 ACM |
543 | { |
544 | struct dccp_sock *dp = dccp_sk(sk); | |
545 | struct sk_buff *skb; | |
7d877f3b | 546 | const gfp_t prio = active ? GFP_KERNEL : GFP_ATOMIC; |
7c657876 | 547 | |
7ad07e7c ACM |
548 | skb = alloc_skb(sk->sk_prot->max_header, prio); |
549 | if (skb == NULL) | |
550 | return; | |
7c657876 ACM |
551 | |
552 | /* Reserve space for headers and prepare control bits. */ | |
553 | skb_reserve(skb, sk->sk_prot->max_header); | |
7690af3f ACM |
554 | DCCP_SKB_CB(skb)->dccpd_type = dp->dccps_role == DCCP_ROLE_CLIENT ? |
555 | DCCP_PKT_CLOSE : DCCP_PKT_CLOSEREQ; | |
7c657876 | 556 | |
7ad07e7c | 557 | if (active) { |
97e5848d | 558 | dccp_write_xmit(sk, 1); |
48918a4d | 559 | dccp_skb_entail(sk, skb); |
7ad07e7c | 560 | dccp_transmit_skb(sk, skb_clone(skb, prio)); |
97e5848d | 561 | /* FIXME do we need a retransmit timer here? */ |
7ad07e7c ACM |
562 | } else |
563 | dccp_transmit_skb(sk, skb); | |
7c657876 | 564 | } |