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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: | |
ee1a1592 | 64 | case DCCP_PKT_RESET: |
7c657876 | 65 | break; |
edc9e819 | 66 | |
afe00251 AB |
67 | case DCCP_PKT_REQUEST: |
68 | set_ack = 0; | |
69 | /* fall through */ | |
70 | ||
7c657876 ACM |
71 | case DCCP_PKT_SYNC: |
72 | case DCCP_PKT_SYNCACK: | |
b0d045ca | 73 | ackno = dcb->dccpd_ack_seq; |
edc9e819 HX |
74 | /* fall through */ |
75 | default: | |
76 | /* | |
ee1a1592 GR |
77 | * Set owner/destructor: some skbs are allocated via |
78 | * alloc_skb (e.g. when retransmission may happen). | |
79 | * Only Data, DataAck, and Reset packets should come | |
80 | * through here with skb->sk set. | |
edc9e819 HX |
81 | */ |
82 | WARN_ON(skb->sk); | |
83 | skb_set_owner_w(skb, sk); | |
7c657876 ACM |
84 | break; |
85 | } | |
24117727 ACM |
86 | |
87 | dcb->dccpd_seq = dp->dccps_gss; | |
2d0817d1 ACM |
88 | |
89 | if (dccp_insert_options(sk, skb)) { | |
90 | kfree_skb(skb); | |
91 | return -EPROTO; | |
92 | } | |
c9eaf173 | 93 | |
fda0fd6c | 94 | |
7c657876 | 95 | /* Build DCCP header and checksum it. */ |
9b42078e | 96 | dh = dccp_zeroed_hdr(skb, dccp_header_size); |
7c657876 ACM |
97 | dh->dccph_type = dcb->dccpd_type; |
98 | dh->dccph_sport = inet->sport; | |
99 | dh->dccph_dport = inet->dport; | |
100 | dh->dccph_doff = (dccp_header_size + dcb->dccpd_opt_len) / 4; | |
101 | dh->dccph_ccval = dcb->dccpd_ccval; | |
6f4e5fff | 102 | dh->dccph_cscov = dp->dccps_pcslen; |
7c657876 ACM |
103 | /* XXX For now we're using only 48 bits sequence numbers */ |
104 | dh->dccph_x = 1; | |
105 | ||
106 | dp->dccps_awh = dp->dccps_gss; | |
107 | dccp_hdr_set_seq(dh, dp->dccps_gss); | |
108 | if (set_ack) | |
109 | dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), ackno); | |
110 | ||
111 | switch (dcb->dccpd_type) { | |
112 | case DCCP_PKT_REQUEST: | |
7690af3f | 113 | dccp_hdr_request(skb)->dccph_req_service = |
67e6b629 | 114 | dp->dccps_service; |
7c657876 ACM |
115 | break; |
116 | case DCCP_PKT_RESET: | |
7690af3f ACM |
117 | dccp_hdr_reset(skb)->dccph_reset_code = |
118 | dcb->dccpd_reset_code; | |
7c657876 ACM |
119 | break; |
120 | } | |
121 | ||
6f4e5fff | 122 | icsk->icsk_af_ops->send_check(sk, 0, skb); |
7c657876 | 123 | |
7ad07e7c | 124 | if (set_ack) |
7c657876 ACM |
125 | dccp_event_ack_sent(sk); |
126 | ||
127 | DCCP_INC_STATS(DCCP_MIB_OUTSEGS); | |
128 | ||
49c5bfaf | 129 | memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); |
e89862f4 | 130 | err = icsk->icsk_af_ops->queue_xmit(skb, 0); |
b9df3cb8 | 131 | return net_xmit_eval(err); |
7c657876 ACM |
132 | } |
133 | return -ENOBUFS; | |
134 | } | |
135 | ||
136 | unsigned int dccp_sync_mss(struct sock *sk, u32 pmtu) | |
137 | { | |
d83d8461 | 138 | struct inet_connection_sock *icsk = inet_csk(sk); |
7c657876 | 139 | struct dccp_sock *dp = dccp_sk(sk); |
d83d8461 | 140 | int mss_now = (pmtu - icsk->icsk_af_ops->net_header_len - |
57cca05a | 141 | sizeof(struct dccp_hdr) - sizeof(struct dccp_hdr_ext)); |
7c657876 ACM |
142 | |
143 | /* Now subtract optional transport overhead */ | |
d83d8461 | 144 | mss_now -= icsk->icsk_ext_hdr_len; |
7c657876 ACM |
145 | |
146 | /* | |
147 | * FIXME: this should come from the CCID infrastructure, where, say, | |
148 | * TFRC will say it wants TIMESTAMPS, ELAPSED time, etc, for now lets | |
149 | * put a rough estimate for NDP + TIMESTAMP + TIMESTAMP_ECHO + ELAPSED | |
150 | * TIME + TFRC_OPT_LOSS_EVENT_RATE + TFRC_OPT_RECEIVE_RATE + padding to | |
151 | * make it a multiple of 4 | |
152 | */ | |
153 | ||
154 | mss_now -= ((5 + 6 + 10 + 6 + 6 + 6 + 3) / 4) * 4; | |
155 | ||
156 | /* And store cached results */ | |
d83d8461 | 157 | icsk->icsk_pmtu_cookie = pmtu; |
7c657876 ACM |
158 | dp->dccps_mss_cache = mss_now; |
159 | ||
160 | return mss_now; | |
161 | } | |
162 | ||
f21e68ca ACM |
163 | EXPORT_SYMBOL_GPL(dccp_sync_mss); |
164 | ||
c530cfb1 ACM |
165 | void dccp_write_space(struct sock *sk) |
166 | { | |
167 | read_lock(&sk->sk_callback_lock); | |
168 | ||
169 | if (sk->sk_sleep && waitqueue_active(sk->sk_sleep)) | |
170 | wake_up_interruptible(sk->sk_sleep); | |
171 | /* Should agree with poll, otherwise some programs break */ | |
172 | if (sock_writeable(sk)) | |
8d8ad9d7 | 173 | sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT); |
c530cfb1 ACM |
174 | |
175 | read_unlock(&sk->sk_callback_lock); | |
176 | } | |
177 | ||
d6809c12 ACM |
178 | /** |
179 | * dccp_wait_for_ccid - Wait for ccid to tell us we can send a packet | |
bc849872 GR |
180 | * @sk: socket to wait for |
181 | * @skb: current skb to pass on for waiting | |
182 | * @delay: sleep timeout in milliseconds (> 0) | |
183 | * This function is called by default when the socket is closed, and | |
184 | * when a non-zero linger time is set on the socket. For consistency | |
d6809c12 | 185 | */ |
bc849872 | 186 | static int dccp_wait_for_ccid(struct sock *sk, struct sk_buff *skb, int delay) |
d6809c12 ACM |
187 | { |
188 | struct dccp_sock *dp = dccp_sk(sk); | |
189 | DEFINE_WAIT(wait); | |
bc849872 | 190 | unsigned long jiffdelay; |
d6809c12 ACM |
191 | int rc; |
192 | ||
bc849872 GR |
193 | do { |
194 | dccp_pr_debug("delayed send by %d msec\n", delay); | |
195 | jiffdelay = msecs_to_jiffies(delay); | |
196 | ||
d6809c12 ACM |
197 | prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE); |
198 | ||
bc849872 GR |
199 | sk->sk_write_pending++; |
200 | release_sock(sk); | |
201 | schedule_timeout(jiffdelay); | |
202 | lock_sock(sk); | |
203 | sk->sk_write_pending--; | |
204 | ||
97e5848d | 205 | if (sk->sk_err) |
d6809c12 | 206 | goto do_error; |
d6809c12 ACM |
207 | if (signal_pending(current)) |
208 | goto do_interrupted; | |
209 | ||
6b57c93d | 210 | rc = ccid_hc_tx_send_packet(dp->dccps_hc_tx_ccid, sk, skb); |
bc849872 | 211 | } while ((delay = rc) > 0); |
d6809c12 ACM |
212 | out: |
213 | finish_wait(sk->sk_sleep, &wait); | |
214 | return rc; | |
215 | ||
216 | do_error: | |
217 | rc = -EPIPE; | |
218 | goto out; | |
d6809c12 | 219 | do_interrupted: |
5cc3741d | 220 | rc = -EINTR; |
d6809c12 ACM |
221 | goto out; |
222 | } | |
223 | ||
97e5848d | 224 | void dccp_write_xmit(struct sock *sk, int block) |
27258ee5 | 225 | { |
97e5848d IM |
226 | struct dccp_sock *dp = dccp_sk(sk); |
227 | struct sk_buff *skb; | |
97e5848d IM |
228 | |
229 | while ((skb = skb_peek(&sk->sk_write_queue))) { | |
6b57c93d | 230 | int err = ccid_hc_tx_send_packet(dp->dccps_hc_tx_ccid, sk, skb); |
d6809c12 | 231 | |
97e5848d IM |
232 | if (err > 0) { |
233 | if (!block) { | |
234 | sk_reset_timer(sk, &dp->dccps_xmit_timer, | |
235 | msecs_to_jiffies(err)+jiffies); | |
236 | break; | |
5cc3741d | 237 | } else |
bc849872 | 238 | err = dccp_wait_for_ccid(sk, skb, err); |
f6282f4d | 239 | if (err && err != -EINTR) |
59348b19 | 240 | DCCP_BUG("err=%d after dccp_wait_for_ccid", err); |
97e5848d | 241 | } |
27258ee5 | 242 | |
97e5848d IM |
243 | skb_dequeue(&sk->sk_write_queue); |
244 | if (err == 0) { | |
245 | struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb); | |
246 | const int len = skb->len; | |
27258ee5 | 247 | |
97e5848d IM |
248 | if (sk->sk_state == DCCP_PARTOPEN) { |
249 | /* See 8.1.5. Handshake Completion */ | |
250 | inet_csk_schedule_ack(sk); | |
251 | inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK, | |
27258ee5 ACM |
252 | inet_csk(sk)->icsk_rto, |
253 | DCCP_RTO_MAX); | |
97e5848d IM |
254 | dcb->dccpd_type = DCCP_PKT_DATAACK; |
255 | } else if (dccp_ack_pending(sk)) | |
256 | dcb->dccpd_type = DCCP_PKT_DATAACK; | |
257 | else | |
258 | dcb->dccpd_type = DCCP_PKT_DATA; | |
259 | ||
260 | err = dccp_transmit_skb(sk, skb); | |
261 | ccid_hc_tx_packet_sent(dp->dccps_hc_tx_ccid, sk, 0, len); | |
59348b19 GR |
262 | if (err) |
263 | DCCP_BUG("err=%d after ccid_hc_tx_packet_sent", | |
264 | err); | |
f6282f4d | 265 | } else { |
6626e362 | 266 | dccp_pr_debug("packet discarded due to err=%d\n", err); |
b08d5840 | 267 | kfree_skb(skb); |
f6282f4d | 268 | } |
97e5848d | 269 | } |
27258ee5 ACM |
270 | } |
271 | ||
7c657876 ACM |
272 | int dccp_retransmit_skb(struct sock *sk, struct sk_buff *skb) |
273 | { | |
57cca05a | 274 | if (inet_csk(sk)->icsk_af_ops->rebuild_header(sk) != 0) |
7c657876 ACM |
275 | return -EHOSTUNREACH; /* Routing failure or similar. */ |
276 | ||
277 | return dccp_transmit_skb(sk, (skb_cloned(skb) ? | |
278 | pskb_copy(skb, GFP_ATOMIC): | |
279 | skb_clone(skb, GFP_ATOMIC))); | |
280 | } | |
281 | ||
282 | struct sk_buff *dccp_make_response(struct sock *sk, struct dst_entry *dst, | |
283 | struct request_sock *req) | |
284 | { | |
285 | struct dccp_hdr *dh; | |
67e6b629 | 286 | struct dccp_request_sock *dreq; |
118b2c95 | 287 | const u32 dccp_header_size = sizeof(struct dccp_hdr) + |
7c657876 ACM |
288 | sizeof(struct dccp_hdr_ext) + |
289 | sizeof(struct dccp_hdr_response); | |
118b2c95 | 290 | struct sk_buff *skb = sock_wmalloc(sk, sk->sk_prot->max_header, 1, |
7c657876 ACM |
291 | GFP_ATOMIC); |
292 | if (skb == NULL) | |
293 | return NULL; | |
294 | ||
295 | /* Reserve space for headers. */ | |
118b2c95 | 296 | skb_reserve(skb, sk->sk_prot->max_header); |
7c657876 ACM |
297 | |
298 | skb->dst = dst_clone(dst); | |
7c657876 | 299 | |
67e6b629 | 300 | dreq = dccp_rsk(req); |
e11d9d30 GR |
301 | if (inet_rsk(req)->acked) /* increase ISS upon retransmission */ |
302 | dccp_inc_seqno(&dreq->dreq_iss); | |
7c657876 | 303 | DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_RESPONSE; |
67e6b629 | 304 | DCCP_SKB_CB(skb)->dccpd_seq = dreq->dreq_iss; |
2d0817d1 ACM |
305 | |
306 | if (dccp_insert_options(sk, skb)) { | |
307 | kfree_skb(skb); | |
308 | return NULL; | |
309 | } | |
7c657876 | 310 | |
09dbc389 | 311 | /* Build and checksum header */ |
9b42078e | 312 | dh = dccp_zeroed_hdr(skb, dccp_header_size); |
7c657876 ACM |
313 | |
314 | dh->dccph_sport = inet_sk(sk)->sport; | |
315 | dh->dccph_dport = inet_rsk(req)->rmt_port; | |
7690af3f ACM |
316 | dh->dccph_doff = (dccp_header_size + |
317 | DCCP_SKB_CB(skb)->dccpd_opt_len) / 4; | |
7c657876 ACM |
318 | dh->dccph_type = DCCP_PKT_RESPONSE; |
319 | dh->dccph_x = 1; | |
67e6b629 ACM |
320 | dccp_hdr_set_seq(dh, dreq->dreq_iss); |
321 | dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), dreq->dreq_isr); | |
322 | dccp_hdr_response(skb)->dccph_resp_service = dreq->dreq_service; | |
7c657876 | 323 | |
6f4e5fff GR |
324 | dccp_csum_outgoing(skb); |
325 | ||
e11d9d30 GR |
326 | /* We use `acked' to remember that a Response was already sent. */ |
327 | inet_rsk(req)->acked = 1; | |
7c657876 ACM |
328 | DCCP_INC_STATS(DCCP_MIB_OUTSEGS); |
329 | return skb; | |
330 | } | |
331 | ||
f21e68ca ACM |
332 | EXPORT_SYMBOL_GPL(dccp_make_response); |
333 | ||
e356d37a GR |
334 | /* answer offending packet in @rcv_skb with Reset from control socket @ctl */ |
335 | struct sk_buff *dccp_ctl_make_reset(struct socket *ctl, struct sk_buff *rcv_skb) | |
336 | { | |
337 | struct dccp_hdr *rxdh = dccp_hdr(rcv_skb), *dh; | |
338 | struct dccp_skb_cb *dcb = DCCP_SKB_CB(rcv_skb); | |
339 | const u32 dccp_hdr_reset_len = sizeof(struct dccp_hdr) + | |
340 | sizeof(struct dccp_hdr_ext) + | |
341 | sizeof(struct dccp_hdr_reset); | |
342 | struct dccp_hdr_reset *dhr; | |
343 | struct sk_buff *skb; | |
344 | ||
345 | skb = alloc_skb(ctl->sk->sk_prot->max_header, GFP_ATOMIC); | |
346 | if (skb == NULL) | |
347 | return NULL; | |
348 | ||
349 | skb_reserve(skb, ctl->sk->sk_prot->max_header); | |
350 | ||
351 | /* Swap the send and the receive. */ | |
352 | dh = dccp_zeroed_hdr(skb, dccp_hdr_reset_len); | |
353 | dh->dccph_type = DCCP_PKT_RESET; | |
354 | dh->dccph_sport = rxdh->dccph_dport; | |
355 | dh->dccph_dport = rxdh->dccph_sport; | |
356 | dh->dccph_doff = dccp_hdr_reset_len / 4; | |
357 | dh->dccph_x = 1; | |
358 | ||
359 | dhr = dccp_hdr_reset(skb); | |
360 | dhr->dccph_reset_code = dcb->dccpd_reset_code; | |
361 | ||
362 | switch (dcb->dccpd_reset_code) { | |
363 | case DCCP_RESET_CODE_PACKET_ERROR: | |
364 | dhr->dccph_reset_data[0] = rxdh->dccph_type; | |
365 | break; | |
366 | case DCCP_RESET_CODE_OPTION_ERROR: /* fall through */ | |
367 | case DCCP_RESET_CODE_MANDATORY_ERROR: | |
368 | memcpy(dhr->dccph_reset_data, dcb->dccpd_reset_data, 3); | |
369 | break; | |
370 | } | |
371 | /* | |
372 | * From RFC 4340, 8.3.1: | |
373 | * If P.ackno exists, set R.seqno := P.ackno + 1. | |
374 | * Else set R.seqno := 0. | |
375 | */ | |
376 | if (dcb->dccpd_ack_seq != DCCP_PKT_WITHOUT_ACK_SEQ) | |
377 | dccp_hdr_set_seq(dh, ADD48(dcb->dccpd_ack_seq, 1)); | |
378 | dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), dcb->dccpd_seq); | |
379 | ||
380 | dccp_csum_outgoing(skb); | |
381 | return skb; | |
382 | } | |
383 | ||
384 | EXPORT_SYMBOL_GPL(dccp_ctl_make_reset); | |
385 | ||
ee1a1592 | 386 | /* send Reset on established socket, to close or abort the connection */ |
017487d7 ACM |
387 | int dccp_send_reset(struct sock *sk, enum dccp_reset_codes code) |
388 | { | |
ee1a1592 | 389 | struct sk_buff *skb; |
017487d7 ACM |
390 | /* |
391 | * FIXME: what if rebuild_header fails? | |
392 | * Should we be doing a rebuild_header here? | |
393 | */ | |
f53dc67c | 394 | int err = inet_csk(sk)->icsk_af_ops->rebuild_header(sk); |
017487d7 | 395 | |
ee1a1592 GR |
396 | if (err != 0) |
397 | return err; | |
398 | ||
399 | skb = sock_wmalloc(sk, sk->sk_prot->max_header, 1, GFP_ATOMIC); | |
400 | if (skb == NULL) | |
401 | return -ENOBUFS; | |
402 | ||
403 | /* Reserve space for headers and prepare control bits. */ | |
404 | skb_reserve(skb, sk->sk_prot->max_header); | |
405 | DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_RESET; | |
406 | DCCP_SKB_CB(skb)->dccpd_reset_code = code; | |
017487d7 | 407 | |
ee1a1592 | 408 | return dccp_transmit_skb(sk, skb); |
017487d7 ACM |
409 | } |
410 | ||
7c657876 ACM |
411 | /* |
412 | * Do all connect socket setups that can be done AF independent. | |
413 | */ | |
414 | static inline void dccp_connect_init(struct sock *sk) | |
415 | { | |
f21e68ca | 416 | struct dccp_sock *dp = dccp_sk(sk); |
7c657876 ACM |
417 | struct dst_entry *dst = __sk_dst_get(sk); |
418 | struct inet_connection_sock *icsk = inet_csk(sk); | |
419 | ||
420 | sk->sk_err = 0; | |
421 | sock_reset_flag(sk, SOCK_DONE); | |
c9eaf173 | 422 | |
7c657876 ACM |
423 | dccp_sync_mss(sk, dst_mtu(dst)); |
424 | ||
8109b02b | 425 | /* |
f21e68ca ACM |
426 | * SWL and AWL are initially adjusted so that they are not less than |
427 | * the initial Sequence Numbers received and sent, respectively: | |
428 | * SWL := max(GSR + 1 - floor(W/4), ISR), | |
429 | * AWL := max(GSS - W' + 1, ISS). | |
430 | * These adjustments MUST be applied only at the beginning of the | |
431 | * connection. | |
8109b02b | 432 | */ |
d7f7365f | 433 | dccp_update_gss(sk, dp->dccps_iss); |
f21e68ca | 434 | dccp_set_seqno(&dp->dccps_awl, max48(dp->dccps_awl, dp->dccps_iss)); |
7c657876 | 435 | |
d7f7365f GR |
436 | /* S.GAR - greatest valid acknowledgement number received on a non-Sync; |
437 | * initialized to S.ISS (sec. 8.5) */ | |
438 | dp->dccps_gar = dp->dccps_iss; | |
439 | ||
7c657876 ACM |
440 | icsk->icsk_retransmits = 0; |
441 | } | |
442 | ||
443 | int dccp_connect(struct sock *sk) | |
444 | { | |
445 | struct sk_buff *skb; | |
446 | struct inet_connection_sock *icsk = inet_csk(sk); | |
447 | ||
448 | dccp_connect_init(sk); | |
449 | ||
118b2c95 | 450 | skb = alloc_skb(sk->sk_prot->max_header, sk->sk_allocation); |
7c657876 ACM |
451 | if (unlikely(skb == NULL)) |
452 | return -ENOBUFS; | |
453 | ||
454 | /* Reserve space for headers. */ | |
118b2c95 | 455 | skb_reserve(skb, sk->sk_prot->max_header); |
7c657876 ACM |
456 | |
457 | DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_REQUEST; | |
7c657876 | 458 | |
48918a4d | 459 | dccp_skb_entail(sk, skb); |
7c657876 ACM |
460 | dccp_transmit_skb(sk, skb_clone(skb, GFP_KERNEL)); |
461 | DCCP_INC_STATS(DCCP_MIB_ACTIVEOPENS); | |
462 | ||
463 | /* Timer for repeating the REQUEST until an answer. */ | |
27258ee5 ACM |
464 | inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, |
465 | icsk->icsk_rto, DCCP_RTO_MAX); | |
7c657876 ACM |
466 | return 0; |
467 | } | |
468 | ||
f21e68ca ACM |
469 | EXPORT_SYMBOL_GPL(dccp_connect); |
470 | ||
7c657876 ACM |
471 | void dccp_send_ack(struct sock *sk) |
472 | { | |
473 | /* If we have been reset, we may not send again. */ | |
474 | if (sk->sk_state != DCCP_CLOSED) { | |
118b2c95 ACM |
475 | struct sk_buff *skb = alloc_skb(sk->sk_prot->max_header, |
476 | GFP_ATOMIC); | |
7c657876 ACM |
477 | |
478 | if (skb == NULL) { | |
479 | inet_csk_schedule_ack(sk); | |
480 | inet_csk(sk)->icsk_ack.ato = TCP_ATO_MIN; | |
7690af3f ACM |
481 | inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK, |
482 | TCP_DELACK_MAX, | |
483 | DCCP_RTO_MAX); | |
7c657876 ACM |
484 | return; |
485 | } | |
486 | ||
487 | /* Reserve space for headers */ | |
118b2c95 | 488 | skb_reserve(skb, sk->sk_prot->max_header); |
7c657876 | 489 | DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_ACK; |
7c657876 ACM |
490 | dccp_transmit_skb(sk, skb); |
491 | } | |
492 | } | |
493 | ||
494 | EXPORT_SYMBOL_GPL(dccp_send_ack); | |
495 | ||
727ecc5f | 496 | /* FIXME: Is this still necessary (11.3) - currently nowhere used by DCCP. */ |
7c657876 ACM |
497 | void dccp_send_delayed_ack(struct sock *sk) |
498 | { | |
499 | struct inet_connection_sock *icsk = inet_csk(sk); | |
500 | /* | |
501 | * FIXME: tune this timer. elapsed time fixes the skew, so no problem | |
502 | * with using 2s, and active senders also piggyback the ACK into a | |
503 | * DATAACK packet, so this is really for quiescent senders. | |
504 | */ | |
505 | unsigned long timeout = jiffies + 2 * HZ; | |
506 | ||
507 | /* Use new timeout only if there wasn't a older one earlier. */ | |
508 | if (icsk->icsk_ack.pending & ICSK_ACK_TIMER) { | |
509 | /* If delack timer was blocked or is about to expire, | |
510 | * send ACK now. | |
511 | * | |
512 | * FIXME: check the "about to expire" part | |
513 | */ | |
514 | if (icsk->icsk_ack.blocked) { | |
515 | dccp_send_ack(sk); | |
516 | return; | |
517 | } | |
518 | ||
519 | if (!time_before(timeout, icsk->icsk_ack.timeout)) | |
520 | timeout = icsk->icsk_ack.timeout; | |
521 | } | |
522 | icsk->icsk_ack.pending |= ICSK_ACK_SCHED | ICSK_ACK_TIMER; | |
523 | icsk->icsk_ack.timeout = timeout; | |
524 | sk_reset_timer(sk, &icsk->icsk_delack_timer, timeout); | |
525 | } | |
526 | ||
b0d045ca | 527 | void dccp_send_sync(struct sock *sk, const u64 ackno, |
e92ae93a | 528 | const enum dccp_pkt_type pkt_type) |
7c657876 ACM |
529 | { |
530 | /* | |
531 | * We are not putting this on the write queue, so | |
532 | * dccp_transmit_skb() will set the ownership to this | |
533 | * sock. | |
534 | */ | |
118b2c95 | 535 | struct sk_buff *skb = alloc_skb(sk->sk_prot->max_header, GFP_ATOMIC); |
7c657876 | 536 | |
b0d045ca | 537 | if (skb == NULL) { |
7c657876 | 538 | /* FIXME: how to make sure the sync is sent? */ |
b0d045ca | 539 | DCCP_CRIT("could not send %s", dccp_packet_name(pkt_type)); |
7c657876 | 540 | return; |
b0d045ca | 541 | } |
7c657876 ACM |
542 | |
543 | /* Reserve space for headers and prepare control bits. */ | |
118b2c95 | 544 | skb_reserve(skb, sk->sk_prot->max_header); |
e92ae93a | 545 | DCCP_SKB_CB(skb)->dccpd_type = pkt_type; |
b0d045ca | 546 | DCCP_SKB_CB(skb)->dccpd_ack_seq = ackno; |
7c657876 | 547 | |
7c657876 ACM |
548 | dccp_transmit_skb(sk, skb); |
549 | } | |
550 | ||
b61fafc4 ACM |
551 | EXPORT_SYMBOL_GPL(dccp_send_sync); |
552 | ||
7690af3f ACM |
553 | /* |
554 | * Send a DCCP_PKT_CLOSE/CLOSEREQ. The caller locks the socket for us. This | |
555 | * cannot be allowed to fail queueing a DCCP_PKT_CLOSE/CLOSEREQ frame under | |
556 | * any circumstances. | |
7c657876 | 557 | */ |
7ad07e7c | 558 | void dccp_send_close(struct sock *sk, const int active) |
7c657876 ACM |
559 | { |
560 | struct dccp_sock *dp = dccp_sk(sk); | |
561 | struct sk_buff *skb; | |
7d877f3b | 562 | const gfp_t prio = active ? GFP_KERNEL : GFP_ATOMIC; |
7c657876 | 563 | |
7ad07e7c ACM |
564 | skb = alloc_skb(sk->sk_prot->max_header, prio); |
565 | if (skb == NULL) | |
566 | return; | |
7c657876 ACM |
567 | |
568 | /* Reserve space for headers and prepare control bits. */ | |
569 | skb_reserve(skb, sk->sk_prot->max_header); | |
7690af3f ACM |
570 | DCCP_SKB_CB(skb)->dccpd_type = dp->dccps_role == DCCP_ROLE_CLIENT ? |
571 | DCCP_PKT_CLOSE : DCCP_PKT_CLOSEREQ; | |
7c657876 | 572 | |
7ad07e7c | 573 | if (active) { |
97e5848d | 574 | dccp_write_xmit(sk, 1); |
48918a4d | 575 | dccp_skb_entail(sk, skb); |
7ad07e7c | 576 | dccp_transmit_skb(sk, skb_clone(skb, prio)); |
97e5848d | 577 | /* FIXME do we need a retransmit timer here? */ |
7ad07e7c ACM |
578 | } else |
579 | dccp_transmit_skb(sk, skb); | |
7c657876 | 580 | } |