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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 | ||
6179983a GR |
136 | /** |
137 | * dccp_determine_ccmps - Find out about CCID-specfic packet-size limits | |
138 | * We only consider the HC-sender CCID for setting the CCMPS (RFC 4340, 14.), | |
139 | * since the RX CCID is restricted to feedback packets (Acks), which are small | |
140 | * in comparison with the data traffic. A value of 0 means "no current CCMPS". | |
141 | */ | |
142 | static u32 dccp_determine_ccmps(const struct dccp_sock *dp) | |
143 | { | |
144 | const struct ccid *tx_ccid = dp->dccps_hc_tx_ccid; | |
145 | ||
146 | if (tx_ccid == NULL || tx_ccid->ccid_ops == NULL) | |
147 | return 0; | |
148 | return tx_ccid->ccid_ops->ccid_ccmps; | |
149 | } | |
150 | ||
7c657876 ACM |
151 | unsigned int dccp_sync_mss(struct sock *sk, u32 pmtu) |
152 | { | |
d83d8461 | 153 | struct inet_connection_sock *icsk = inet_csk(sk); |
7c657876 | 154 | struct dccp_sock *dp = dccp_sk(sk); |
6179983a GR |
155 | u32 ccmps = dccp_determine_ccmps(dp); |
156 | int cur_mps = ccmps ? min(pmtu, ccmps) : pmtu; | |
7c657876 | 157 | |
6179983a GR |
158 | /* Account for header lengths and IPv4/v6 option overhead */ |
159 | cur_mps -= (icsk->icsk_af_ops->net_header_len + icsk->icsk_ext_hdr_len + | |
160 | sizeof(struct dccp_hdr) + sizeof(struct dccp_hdr_ext)); | |
7c657876 ACM |
161 | |
162 | /* | |
163 | * FIXME: this should come from the CCID infrastructure, where, say, | |
164 | * TFRC will say it wants TIMESTAMPS, ELAPSED time, etc, for now lets | |
165 | * put a rough estimate for NDP + TIMESTAMP + TIMESTAMP_ECHO + ELAPSED | |
166 | * TIME + TFRC_OPT_LOSS_EVENT_RATE + TFRC_OPT_RECEIVE_RATE + padding to | |
167 | * make it a multiple of 4 | |
168 | */ | |
169 | ||
6179983a | 170 | cur_mps -= ((5 + 6 + 10 + 6 + 6 + 6 + 3) / 4) * 4; |
7c657876 ACM |
171 | |
172 | /* And store cached results */ | |
d83d8461 | 173 | icsk->icsk_pmtu_cookie = pmtu; |
6179983a | 174 | dp->dccps_mss_cache = cur_mps; |
7c657876 | 175 | |
6179983a | 176 | return cur_mps; |
7c657876 ACM |
177 | } |
178 | ||
f21e68ca ACM |
179 | EXPORT_SYMBOL_GPL(dccp_sync_mss); |
180 | ||
c530cfb1 ACM |
181 | void dccp_write_space(struct sock *sk) |
182 | { | |
183 | read_lock(&sk->sk_callback_lock); | |
184 | ||
185 | if (sk->sk_sleep && waitqueue_active(sk->sk_sleep)) | |
186 | wake_up_interruptible(sk->sk_sleep); | |
187 | /* Should agree with poll, otherwise some programs break */ | |
188 | if (sock_writeable(sk)) | |
8d8ad9d7 | 189 | sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT); |
c530cfb1 ACM |
190 | |
191 | read_unlock(&sk->sk_callback_lock); | |
192 | } | |
193 | ||
d6809c12 ACM |
194 | /** |
195 | * dccp_wait_for_ccid - Wait for ccid to tell us we can send a packet | |
bc849872 GR |
196 | * @sk: socket to wait for |
197 | * @skb: current skb to pass on for waiting | |
198 | * @delay: sleep timeout in milliseconds (> 0) | |
199 | * This function is called by default when the socket is closed, and | |
200 | * when a non-zero linger time is set on the socket. For consistency | |
d6809c12 | 201 | */ |
bc849872 | 202 | static int dccp_wait_for_ccid(struct sock *sk, struct sk_buff *skb, int delay) |
d6809c12 ACM |
203 | { |
204 | struct dccp_sock *dp = dccp_sk(sk); | |
205 | DEFINE_WAIT(wait); | |
bc849872 | 206 | unsigned long jiffdelay; |
d6809c12 ACM |
207 | int rc; |
208 | ||
bc849872 GR |
209 | do { |
210 | dccp_pr_debug("delayed send by %d msec\n", delay); | |
211 | jiffdelay = msecs_to_jiffies(delay); | |
212 | ||
d6809c12 ACM |
213 | prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE); |
214 | ||
bc849872 GR |
215 | sk->sk_write_pending++; |
216 | release_sock(sk); | |
217 | schedule_timeout(jiffdelay); | |
218 | lock_sock(sk); | |
219 | sk->sk_write_pending--; | |
220 | ||
97e5848d | 221 | if (sk->sk_err) |
d6809c12 | 222 | goto do_error; |
d6809c12 ACM |
223 | if (signal_pending(current)) |
224 | goto do_interrupted; | |
225 | ||
6b57c93d | 226 | rc = ccid_hc_tx_send_packet(dp->dccps_hc_tx_ccid, sk, skb); |
bc849872 | 227 | } while ((delay = rc) > 0); |
d6809c12 ACM |
228 | out: |
229 | finish_wait(sk->sk_sleep, &wait); | |
230 | return rc; | |
231 | ||
232 | do_error: | |
233 | rc = -EPIPE; | |
234 | goto out; | |
d6809c12 | 235 | do_interrupted: |
5cc3741d | 236 | rc = -EINTR; |
d6809c12 ACM |
237 | goto out; |
238 | } | |
239 | ||
97e5848d | 240 | void dccp_write_xmit(struct sock *sk, int block) |
27258ee5 | 241 | { |
97e5848d IM |
242 | struct dccp_sock *dp = dccp_sk(sk); |
243 | struct sk_buff *skb; | |
97e5848d IM |
244 | |
245 | while ((skb = skb_peek(&sk->sk_write_queue))) { | |
6b57c93d | 246 | int err = ccid_hc_tx_send_packet(dp->dccps_hc_tx_ccid, sk, skb); |
d6809c12 | 247 | |
97e5848d IM |
248 | if (err > 0) { |
249 | if (!block) { | |
250 | sk_reset_timer(sk, &dp->dccps_xmit_timer, | |
251 | msecs_to_jiffies(err)+jiffies); | |
252 | break; | |
5cc3741d | 253 | } else |
bc849872 | 254 | err = dccp_wait_for_ccid(sk, skb, err); |
f6282f4d | 255 | if (err && err != -EINTR) |
59348b19 | 256 | DCCP_BUG("err=%d after dccp_wait_for_ccid", err); |
97e5848d | 257 | } |
27258ee5 | 258 | |
97e5848d IM |
259 | skb_dequeue(&sk->sk_write_queue); |
260 | if (err == 0) { | |
261 | struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb); | |
262 | const int len = skb->len; | |
27258ee5 | 263 | |
97e5848d IM |
264 | if (sk->sk_state == DCCP_PARTOPEN) { |
265 | /* See 8.1.5. Handshake Completion */ | |
266 | inet_csk_schedule_ack(sk); | |
267 | inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK, | |
27258ee5 ACM |
268 | inet_csk(sk)->icsk_rto, |
269 | DCCP_RTO_MAX); | |
97e5848d IM |
270 | dcb->dccpd_type = DCCP_PKT_DATAACK; |
271 | } else if (dccp_ack_pending(sk)) | |
272 | dcb->dccpd_type = DCCP_PKT_DATAACK; | |
273 | else | |
274 | dcb->dccpd_type = DCCP_PKT_DATA; | |
275 | ||
276 | err = dccp_transmit_skb(sk, skb); | |
277 | ccid_hc_tx_packet_sent(dp->dccps_hc_tx_ccid, sk, 0, len); | |
59348b19 GR |
278 | if (err) |
279 | DCCP_BUG("err=%d after ccid_hc_tx_packet_sent", | |
280 | err); | |
f6282f4d | 281 | } else { |
6626e362 | 282 | dccp_pr_debug("packet discarded due to err=%d\n", err); |
b08d5840 | 283 | kfree_skb(skb); |
f6282f4d | 284 | } |
97e5848d | 285 | } |
27258ee5 ACM |
286 | } |
287 | ||
7c657876 ACM |
288 | int dccp_retransmit_skb(struct sock *sk, struct sk_buff *skb) |
289 | { | |
57cca05a | 290 | if (inet_csk(sk)->icsk_af_ops->rebuild_header(sk) != 0) |
7c657876 ACM |
291 | return -EHOSTUNREACH; /* Routing failure or similar. */ |
292 | ||
293 | return dccp_transmit_skb(sk, (skb_cloned(skb) ? | |
294 | pskb_copy(skb, GFP_ATOMIC): | |
295 | skb_clone(skb, GFP_ATOMIC))); | |
296 | } | |
297 | ||
298 | struct sk_buff *dccp_make_response(struct sock *sk, struct dst_entry *dst, | |
299 | struct request_sock *req) | |
300 | { | |
301 | struct dccp_hdr *dh; | |
67e6b629 | 302 | struct dccp_request_sock *dreq; |
118b2c95 | 303 | const u32 dccp_header_size = sizeof(struct dccp_hdr) + |
7c657876 ACM |
304 | sizeof(struct dccp_hdr_ext) + |
305 | sizeof(struct dccp_hdr_response); | |
118b2c95 | 306 | struct sk_buff *skb = sock_wmalloc(sk, sk->sk_prot->max_header, 1, |
7c657876 ACM |
307 | GFP_ATOMIC); |
308 | if (skb == NULL) | |
309 | return NULL; | |
310 | ||
311 | /* Reserve space for headers. */ | |
118b2c95 | 312 | skb_reserve(skb, sk->sk_prot->max_header); |
7c657876 ACM |
313 | |
314 | skb->dst = dst_clone(dst); | |
7c657876 | 315 | |
67e6b629 | 316 | dreq = dccp_rsk(req); |
e11d9d30 GR |
317 | if (inet_rsk(req)->acked) /* increase ISS upon retransmission */ |
318 | dccp_inc_seqno(&dreq->dreq_iss); | |
7c657876 | 319 | DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_RESPONSE; |
67e6b629 | 320 | DCCP_SKB_CB(skb)->dccpd_seq = dreq->dreq_iss; |
2d0817d1 | 321 | |
af3b867e | 322 | if (dccp_insert_options_rsk(dreq, skb)) { |
2d0817d1 ACM |
323 | kfree_skb(skb); |
324 | return NULL; | |
325 | } | |
7c657876 | 326 | |
09dbc389 | 327 | /* Build and checksum header */ |
9b42078e | 328 | dh = dccp_zeroed_hdr(skb, dccp_header_size); |
7c657876 ACM |
329 | |
330 | dh->dccph_sport = inet_sk(sk)->sport; | |
331 | dh->dccph_dport = inet_rsk(req)->rmt_port; | |
7690af3f ACM |
332 | dh->dccph_doff = (dccp_header_size + |
333 | DCCP_SKB_CB(skb)->dccpd_opt_len) / 4; | |
7c657876 ACM |
334 | dh->dccph_type = DCCP_PKT_RESPONSE; |
335 | dh->dccph_x = 1; | |
67e6b629 ACM |
336 | dccp_hdr_set_seq(dh, dreq->dreq_iss); |
337 | dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), dreq->dreq_isr); | |
338 | dccp_hdr_response(skb)->dccph_resp_service = dreq->dreq_service; | |
7c657876 | 339 | |
6f4e5fff GR |
340 | dccp_csum_outgoing(skb); |
341 | ||
e11d9d30 GR |
342 | /* We use `acked' to remember that a Response was already sent. */ |
343 | inet_rsk(req)->acked = 1; | |
7c657876 ACM |
344 | DCCP_INC_STATS(DCCP_MIB_OUTSEGS); |
345 | return skb; | |
346 | } | |
347 | ||
f21e68ca ACM |
348 | EXPORT_SYMBOL_GPL(dccp_make_response); |
349 | ||
e356d37a GR |
350 | /* answer offending packet in @rcv_skb with Reset from control socket @ctl */ |
351 | struct sk_buff *dccp_ctl_make_reset(struct socket *ctl, struct sk_buff *rcv_skb) | |
352 | { | |
353 | struct dccp_hdr *rxdh = dccp_hdr(rcv_skb), *dh; | |
354 | struct dccp_skb_cb *dcb = DCCP_SKB_CB(rcv_skb); | |
355 | const u32 dccp_hdr_reset_len = sizeof(struct dccp_hdr) + | |
356 | sizeof(struct dccp_hdr_ext) + | |
357 | sizeof(struct dccp_hdr_reset); | |
358 | struct dccp_hdr_reset *dhr; | |
359 | struct sk_buff *skb; | |
360 | ||
361 | skb = alloc_skb(ctl->sk->sk_prot->max_header, GFP_ATOMIC); | |
362 | if (skb == NULL) | |
363 | return NULL; | |
364 | ||
365 | skb_reserve(skb, ctl->sk->sk_prot->max_header); | |
366 | ||
367 | /* Swap the send and the receive. */ | |
368 | dh = dccp_zeroed_hdr(skb, dccp_hdr_reset_len); | |
369 | dh->dccph_type = DCCP_PKT_RESET; | |
370 | dh->dccph_sport = rxdh->dccph_dport; | |
371 | dh->dccph_dport = rxdh->dccph_sport; | |
372 | dh->dccph_doff = dccp_hdr_reset_len / 4; | |
373 | dh->dccph_x = 1; | |
374 | ||
375 | dhr = dccp_hdr_reset(skb); | |
376 | dhr->dccph_reset_code = dcb->dccpd_reset_code; | |
377 | ||
378 | switch (dcb->dccpd_reset_code) { | |
379 | case DCCP_RESET_CODE_PACKET_ERROR: | |
380 | dhr->dccph_reset_data[0] = rxdh->dccph_type; | |
381 | break; | |
382 | case DCCP_RESET_CODE_OPTION_ERROR: /* fall through */ | |
383 | case DCCP_RESET_CODE_MANDATORY_ERROR: | |
384 | memcpy(dhr->dccph_reset_data, dcb->dccpd_reset_data, 3); | |
385 | break; | |
386 | } | |
387 | /* | |
388 | * From RFC 4340, 8.3.1: | |
389 | * If P.ackno exists, set R.seqno := P.ackno + 1. | |
390 | * Else set R.seqno := 0. | |
391 | */ | |
392 | if (dcb->dccpd_ack_seq != DCCP_PKT_WITHOUT_ACK_SEQ) | |
393 | dccp_hdr_set_seq(dh, ADD48(dcb->dccpd_ack_seq, 1)); | |
394 | dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), dcb->dccpd_seq); | |
395 | ||
396 | dccp_csum_outgoing(skb); | |
397 | return skb; | |
398 | } | |
399 | ||
400 | EXPORT_SYMBOL_GPL(dccp_ctl_make_reset); | |
401 | ||
ee1a1592 | 402 | /* send Reset on established socket, to close or abort the connection */ |
017487d7 ACM |
403 | int dccp_send_reset(struct sock *sk, enum dccp_reset_codes code) |
404 | { | |
ee1a1592 | 405 | struct sk_buff *skb; |
017487d7 ACM |
406 | /* |
407 | * FIXME: what if rebuild_header fails? | |
408 | * Should we be doing a rebuild_header here? | |
409 | */ | |
f53dc67c | 410 | int err = inet_csk(sk)->icsk_af_ops->rebuild_header(sk); |
017487d7 | 411 | |
ee1a1592 GR |
412 | if (err != 0) |
413 | return err; | |
414 | ||
415 | skb = sock_wmalloc(sk, sk->sk_prot->max_header, 1, GFP_ATOMIC); | |
416 | if (skb == NULL) | |
417 | return -ENOBUFS; | |
418 | ||
419 | /* Reserve space for headers and prepare control bits. */ | |
420 | skb_reserve(skb, sk->sk_prot->max_header); | |
421 | DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_RESET; | |
422 | DCCP_SKB_CB(skb)->dccpd_reset_code = code; | |
017487d7 | 423 | |
ee1a1592 | 424 | return dccp_transmit_skb(sk, skb); |
017487d7 ACM |
425 | } |
426 | ||
7c657876 ACM |
427 | /* |
428 | * Do all connect socket setups that can be done AF independent. | |
429 | */ | |
430 | static inline void dccp_connect_init(struct sock *sk) | |
431 | { | |
f21e68ca | 432 | struct dccp_sock *dp = dccp_sk(sk); |
7c657876 ACM |
433 | struct dst_entry *dst = __sk_dst_get(sk); |
434 | struct inet_connection_sock *icsk = inet_csk(sk); | |
435 | ||
436 | sk->sk_err = 0; | |
437 | sock_reset_flag(sk, SOCK_DONE); | |
c9eaf173 | 438 | |
7c657876 ACM |
439 | dccp_sync_mss(sk, dst_mtu(dst)); |
440 | ||
8109b02b | 441 | /* |
f21e68ca ACM |
442 | * SWL and AWL are initially adjusted so that they are not less than |
443 | * the initial Sequence Numbers received and sent, respectively: | |
444 | * SWL := max(GSR + 1 - floor(W/4), ISR), | |
445 | * AWL := max(GSS - W' + 1, ISS). | |
446 | * These adjustments MUST be applied only at the beginning of the | |
447 | * connection. | |
8109b02b | 448 | */ |
d7f7365f | 449 | dccp_update_gss(sk, dp->dccps_iss); |
f21e68ca | 450 | dccp_set_seqno(&dp->dccps_awl, max48(dp->dccps_awl, dp->dccps_iss)); |
7c657876 | 451 | |
d7f7365f GR |
452 | /* S.GAR - greatest valid acknowledgement number received on a non-Sync; |
453 | * initialized to S.ISS (sec. 8.5) */ | |
454 | dp->dccps_gar = dp->dccps_iss; | |
455 | ||
7c657876 ACM |
456 | icsk->icsk_retransmits = 0; |
457 | } | |
458 | ||
459 | int dccp_connect(struct sock *sk) | |
460 | { | |
461 | struct sk_buff *skb; | |
462 | struct inet_connection_sock *icsk = inet_csk(sk); | |
463 | ||
464 | dccp_connect_init(sk); | |
465 | ||
118b2c95 | 466 | skb = alloc_skb(sk->sk_prot->max_header, sk->sk_allocation); |
7c657876 ACM |
467 | if (unlikely(skb == NULL)) |
468 | return -ENOBUFS; | |
469 | ||
470 | /* Reserve space for headers. */ | |
118b2c95 | 471 | skb_reserve(skb, sk->sk_prot->max_header); |
7c657876 ACM |
472 | |
473 | DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_REQUEST; | |
7c657876 | 474 | |
48918a4d | 475 | dccp_skb_entail(sk, skb); |
7c657876 ACM |
476 | dccp_transmit_skb(sk, skb_clone(skb, GFP_KERNEL)); |
477 | DCCP_INC_STATS(DCCP_MIB_ACTIVEOPENS); | |
478 | ||
479 | /* Timer for repeating the REQUEST until an answer. */ | |
27258ee5 ACM |
480 | inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, |
481 | icsk->icsk_rto, DCCP_RTO_MAX); | |
7c657876 ACM |
482 | return 0; |
483 | } | |
484 | ||
f21e68ca ACM |
485 | EXPORT_SYMBOL_GPL(dccp_connect); |
486 | ||
7c657876 ACM |
487 | void dccp_send_ack(struct sock *sk) |
488 | { | |
489 | /* If we have been reset, we may not send again. */ | |
490 | if (sk->sk_state != DCCP_CLOSED) { | |
118b2c95 ACM |
491 | struct sk_buff *skb = alloc_skb(sk->sk_prot->max_header, |
492 | GFP_ATOMIC); | |
7c657876 ACM |
493 | |
494 | if (skb == NULL) { | |
495 | inet_csk_schedule_ack(sk); | |
496 | inet_csk(sk)->icsk_ack.ato = TCP_ATO_MIN; | |
7690af3f ACM |
497 | inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK, |
498 | TCP_DELACK_MAX, | |
499 | DCCP_RTO_MAX); | |
7c657876 ACM |
500 | return; |
501 | } | |
502 | ||
503 | /* Reserve space for headers */ | |
118b2c95 | 504 | skb_reserve(skb, sk->sk_prot->max_header); |
7c657876 | 505 | DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_ACK; |
7c657876 ACM |
506 | dccp_transmit_skb(sk, skb); |
507 | } | |
508 | } | |
509 | ||
510 | EXPORT_SYMBOL_GPL(dccp_send_ack); | |
511 | ||
727ecc5f | 512 | /* FIXME: Is this still necessary (11.3) - currently nowhere used by DCCP. */ |
7c657876 ACM |
513 | void dccp_send_delayed_ack(struct sock *sk) |
514 | { | |
515 | struct inet_connection_sock *icsk = inet_csk(sk); | |
516 | /* | |
517 | * FIXME: tune this timer. elapsed time fixes the skew, so no problem | |
518 | * with using 2s, and active senders also piggyback the ACK into a | |
519 | * DATAACK packet, so this is really for quiescent senders. | |
520 | */ | |
521 | unsigned long timeout = jiffies + 2 * HZ; | |
522 | ||
523 | /* Use new timeout only if there wasn't a older one earlier. */ | |
524 | if (icsk->icsk_ack.pending & ICSK_ACK_TIMER) { | |
525 | /* If delack timer was blocked or is about to expire, | |
526 | * send ACK now. | |
527 | * | |
528 | * FIXME: check the "about to expire" part | |
529 | */ | |
530 | if (icsk->icsk_ack.blocked) { | |
531 | dccp_send_ack(sk); | |
532 | return; | |
533 | } | |
534 | ||
535 | if (!time_before(timeout, icsk->icsk_ack.timeout)) | |
536 | timeout = icsk->icsk_ack.timeout; | |
537 | } | |
538 | icsk->icsk_ack.pending |= ICSK_ACK_SCHED | ICSK_ACK_TIMER; | |
539 | icsk->icsk_ack.timeout = timeout; | |
540 | sk_reset_timer(sk, &icsk->icsk_delack_timer, timeout); | |
541 | } | |
542 | ||
b0d045ca | 543 | void dccp_send_sync(struct sock *sk, const u64 ackno, |
e92ae93a | 544 | const enum dccp_pkt_type pkt_type) |
7c657876 ACM |
545 | { |
546 | /* | |
547 | * We are not putting this on the write queue, so | |
548 | * dccp_transmit_skb() will set the ownership to this | |
549 | * sock. | |
550 | */ | |
118b2c95 | 551 | struct sk_buff *skb = alloc_skb(sk->sk_prot->max_header, GFP_ATOMIC); |
7c657876 | 552 | |
b0d045ca | 553 | if (skb == NULL) { |
7c657876 | 554 | /* FIXME: how to make sure the sync is sent? */ |
b0d045ca | 555 | DCCP_CRIT("could not send %s", dccp_packet_name(pkt_type)); |
7c657876 | 556 | return; |
b0d045ca | 557 | } |
7c657876 ACM |
558 | |
559 | /* Reserve space for headers and prepare control bits. */ | |
118b2c95 | 560 | skb_reserve(skb, sk->sk_prot->max_header); |
e92ae93a | 561 | DCCP_SKB_CB(skb)->dccpd_type = pkt_type; |
b0d045ca | 562 | DCCP_SKB_CB(skb)->dccpd_ack_seq = ackno; |
7c657876 | 563 | |
7c657876 ACM |
564 | dccp_transmit_skb(sk, skb); |
565 | } | |
566 | ||
b61fafc4 ACM |
567 | EXPORT_SYMBOL_GPL(dccp_send_sync); |
568 | ||
7690af3f ACM |
569 | /* |
570 | * Send a DCCP_PKT_CLOSE/CLOSEREQ. The caller locks the socket for us. This | |
571 | * cannot be allowed to fail queueing a DCCP_PKT_CLOSE/CLOSEREQ frame under | |
572 | * any circumstances. | |
7c657876 | 573 | */ |
7ad07e7c | 574 | void dccp_send_close(struct sock *sk, const int active) |
7c657876 ACM |
575 | { |
576 | struct dccp_sock *dp = dccp_sk(sk); | |
577 | struct sk_buff *skb; | |
7d877f3b | 578 | const gfp_t prio = active ? GFP_KERNEL : GFP_ATOMIC; |
7c657876 | 579 | |
7ad07e7c ACM |
580 | skb = alloc_skb(sk->sk_prot->max_header, prio); |
581 | if (skb == NULL) | |
582 | return; | |
7c657876 ACM |
583 | |
584 | /* Reserve space for headers and prepare control bits. */ | |
585 | skb_reserve(skb, sk->sk_prot->max_header); | |
b8599d20 GR |
586 | if (dp->dccps_role == DCCP_ROLE_SERVER && !dp->dccps_server_timewait) |
587 | DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_CLOSEREQ; | |
588 | else | |
589 | DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_CLOSE; | |
7c657876 | 590 | |
7ad07e7c | 591 | if (active) { |
97e5848d | 592 | dccp_write_xmit(sk, 1); |
48918a4d | 593 | dccp_skb_entail(sk, skb); |
7ad07e7c | 594 | dccp_transmit_skb(sk, skb_clone(skb, prio)); |
92d31920 GR |
595 | /* |
596 | * Retransmission timer for active-close: RFC 4340, 8.3 requires | |
597 | * to retransmit the Close/CloseReq until the CLOSING/CLOSEREQ | |
598 | * state can be left. The initial timeout is 2 RTTs. | |
599 | * Since RTT measurement is done by the CCIDs, there is no easy | |
600 | * way to get an RTT sample. The fallback RTT from RFC 4340, 3.4 | |
601 | * is too low (200ms); we use a high value to avoid unnecessary | |
602 | * retransmissions when the link RTT is > 0.2 seconds. | |
603 | * FIXME: Let main module sample RTTs and use that instead. | |
604 | */ | |
605 | inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, | |
606 | DCCP_TIMEOUT_INIT, DCCP_RTO_MAX); | |
7ad07e7c ACM |
607 | } else |
608 | dccp_transmit_skb(sk, skb); | |
7c657876 | 609 | } |