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NetLabel: add tag verification when adding new CIPSOv4 DOI definitions
[firewire-audio.git] / net / dccp / options.c
blob7e50678e247159bb0d5b8568c7bfaf5ea9defeea
1 /*
2 * net/dccp/options.c
3 *
4 * An implementation of the DCCP protocol
5 * Copyright (c) 2005 Aristeu Sergio Rozanski Filho <aris@cathedrallabs.org>
6 * Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
7 * Copyright (c) 2005 Ian McDonald <ian.mcdonald@jandi.co.nz>
8 *
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License
11 * as published by the Free Software Foundation; either version
12 * 2 of the License, or (at your option) any later version.
13 */
14 #include <linux/dccp.h>
15 #include <linux/module.h>
16 #include <linux/types.h>
17 #include <linux/kernel.h>
18 #include <linux/skbuff.h>
19
20 #include "ackvec.h"
21 #include "ccid.h"
22 #include "dccp.h"
23 #include "feat.h"
24
25 int sysctl_dccp_feat_sequence_window = DCCPF_INITIAL_SEQUENCE_WINDOW;
26 int sysctl_dccp_feat_rx_ccid = DCCPF_INITIAL_CCID;
27 int sysctl_dccp_feat_tx_ccid = DCCPF_INITIAL_CCID;
28 int sysctl_dccp_feat_ack_ratio = DCCPF_INITIAL_ACK_RATIO;
29 int sysctl_dccp_feat_send_ack_vector = DCCPF_INITIAL_SEND_ACK_VECTOR;
30 int sysctl_dccp_feat_send_ndp_count = DCCPF_INITIAL_SEND_NDP_COUNT;
31
32 EXPORT_SYMBOL_GPL(sysctl_dccp_feat_sequence_window);
33
34 void dccp_minisock_init(struct dccp_minisock *dmsk)
35 {
36 dmsk->dccpms_sequence_window = sysctl_dccp_feat_sequence_window;
37 dmsk->dccpms_rx_ccid = sysctl_dccp_feat_rx_ccid;
38 dmsk->dccpms_tx_ccid = sysctl_dccp_feat_tx_ccid;
39 dmsk->dccpms_ack_ratio = sysctl_dccp_feat_ack_ratio;
40 dmsk->dccpms_send_ack_vector = sysctl_dccp_feat_send_ack_vector;
41 dmsk->dccpms_send_ndp_count = sysctl_dccp_feat_send_ndp_count;
42 }
43
44 static u32 dccp_decode_value_var(const unsigned char *bf, const u8 len)
45 {
46 u32 value = 0;
47
48 if (len > 3)
49 value += *bf++ << 24;
50 if (len > 2)
51 value += *bf++ << 16;
52 if (len > 1)
53 value += *bf++ << 8;
54 if (len > 0)
55 value += *bf;
56
57 return value;
58 }
59
60 int dccp_parse_options(struct sock *sk, struct sk_buff *skb)
61 {
62 struct dccp_sock *dp = dccp_sk(sk);
63 const struct dccp_hdr *dh = dccp_hdr(skb);
64 const u8 pkt_type = DCCP_SKB_CB(skb)->dccpd_type;
65 unsigned char *options = (unsigned char *)dh + dccp_hdr_len(skb);
66 unsigned char *opt_ptr = options;
67 const unsigned char *opt_end = (unsigned char *)dh +
68 (dh->dccph_doff * 4);
69 struct dccp_options_received *opt_recv = &dp->dccps_options_received;
70 unsigned char opt, len;
71 unsigned char *value;
72 u32 elapsed_time;
73 int rc;
74 int mandatory = 0;
75
76 memset(opt_recv, 0, sizeof(*opt_recv));
77
78 opt = len = 0;
79 while (opt_ptr != opt_end) {
80 opt = *opt_ptr++;
81 len = 0;
82 value = NULL;
83
84 /* Check if this isn't a single byte option */
85 if (opt > DCCPO_MAX_RESERVED) {
86 if (opt_ptr == opt_end)
87 goto out_invalid_option;
88
89 len = *opt_ptr++;
90 if (len < 3)
91 goto out_invalid_option;
92 /*
93 * Remove the type and len fields, leaving
94 * just the value size
95 */
96 len -= 2;
97 value = opt_ptr;
98 opt_ptr += len;
99
100 if (opt_ptr > opt_end)
101 goto out_invalid_option;
102 }
103
104 switch (opt) {
105 case DCCPO_PADDING:
106 break;
107 case DCCPO_MANDATORY:
108 if (mandatory)
109 goto out_invalid_option;
110 if (pkt_type != DCCP_PKT_DATA)
111 mandatory = 1;
112 break;
113 case DCCPO_NDP_COUNT:
114 if (len > 3)
115 goto out_invalid_option;
116
117 opt_recv->dccpor_ndp = dccp_decode_value_var(value, len);
118 dccp_pr_debug("%s rx opt: NDP count=%d\n", dccp_role(sk),
119 opt_recv->dccpor_ndp);
120 break;
121 case DCCPO_CHANGE_L:
122 /* fall through */
123 case DCCPO_CHANGE_R:
124 if (len < 2)
125 goto out_invalid_option;
126 rc = dccp_feat_change_recv(sk, opt, *value, value + 1,
127 len - 1);
128 /*
129 * When there is a change error, change_recv is
130 * responsible for dealing with it. i.e. reply with an
131 * empty confirm.
132 * If the change was mandatory, then we need to die.
133 */
134 if (rc && mandatory)
135 goto out_invalid_option;
136 break;
137 case DCCPO_CONFIRM_L:
138 /* fall through */
139 case DCCPO_CONFIRM_R:
140 if (len < 2)
141 goto out_invalid_option;
142 if (dccp_feat_confirm_recv(sk, opt, *value,
143 value + 1, len - 1))
144 goto out_invalid_option;
145 break;
146 case DCCPO_ACK_VECTOR_0:
147 case DCCPO_ACK_VECTOR_1:
148 if (pkt_type == DCCP_PKT_DATA)
149 break;
150
151 if (dccp_msk(sk)->dccpms_send_ack_vector &&
152 dccp_ackvec_parse(sk, skb, opt, value, len))
153 goto out_invalid_option;
154 break;
155 case DCCPO_TIMESTAMP:
156 if (len != 4)
157 goto out_invalid_option;
158
159 opt_recv->dccpor_timestamp = ntohl(*(__be32 *)value);
160
161 dp->dccps_timestamp_echo = opt_recv->dccpor_timestamp;
162 dccp_timestamp(sk, &dp->dccps_timestamp_time);
163
164 dccp_pr_debug("%s rx opt: TIMESTAMP=%u, ackno=%llu\n",
165 dccp_role(sk), opt_recv->dccpor_timestamp,
166 (unsigned long long)
167 DCCP_SKB_CB(skb)->dccpd_ack_seq);
168 break;
169 case DCCPO_TIMESTAMP_ECHO:
170 if (len != 4 && len != 6 && len != 8)
171 goto out_invalid_option;
172
173 opt_recv->dccpor_timestamp_echo = ntohl(*(__be32 *)value);
174
175 dccp_pr_debug("%s rx opt: TIMESTAMP_ECHO=%u, len=%d, "
176 "ackno=%llu, ", dccp_role(sk),
177 opt_recv->dccpor_timestamp_echo,
178 len + 2,
179 (unsigned long long)
180 DCCP_SKB_CB(skb)->dccpd_ack_seq);
181
182
183 if (len == 4)
184 break;
185
186 if (len == 6)
187 elapsed_time = ntohs(*(__be16 *)(value + 4));
188 else
189 elapsed_time = ntohl(*(__be32 *)(value + 4));
190
191 /* Give precedence to the biggest ELAPSED_TIME */
192 if (elapsed_time > opt_recv->dccpor_elapsed_time)
193 opt_recv->dccpor_elapsed_time = elapsed_time;
194 break;
195 case DCCPO_ELAPSED_TIME:
196 if (len != 2 && len != 4)
197 goto out_invalid_option;
198
199 if (pkt_type == DCCP_PKT_DATA)
200 continue;
201
202 if (len == 2)
203 elapsed_time = ntohs(*(__be16 *)value);
204 else
205 elapsed_time = ntohl(*(__be32 *)value);
206
207 if (elapsed_time > opt_recv->dccpor_elapsed_time)
208 opt_recv->dccpor_elapsed_time = elapsed_time;
209
210 dccp_pr_debug("%s rx opt: ELAPSED_TIME=%d\n",
211 dccp_role(sk), elapsed_time);
212 break;
213 /*
214 * From RFC 4340, sec. 10.3:
215 *
216 * Option numbers 128 through 191 are for
217 * options sent from the HC-Sender to the
218 * HC-Receiver; option numbers 192 through 255
219 * are for options sent from the HC-Receiver to
220 * the HC-Sender.
221 */
222 case 128 ... 191: {
223 const u16 idx = value - options;
224
225 if (ccid_hc_rx_parse_options(dp->dccps_hc_rx_ccid, sk,
226 opt, len, idx,
227 value) != 0)
228 goto out_invalid_option;
229 }
230 break;
231 case 192 ... 255: {
232 const u16 idx = value - options;
233
234 if (ccid_hc_tx_parse_options(dp->dccps_hc_tx_ccid, sk,
235 opt, len, idx,
236 value) != 0)
237 goto out_invalid_option;
238 }
239 break;
240 default:
241 pr_info("DCCP(%p): option %d(len=%d) not "
242 "implemented, ignoring\n",
243 sk, opt, len);
244 break;
245 }
246
247 if (opt != DCCPO_MANDATORY)
248 mandatory = 0;
249 }
250
251 /* mandatory was the last byte in option list -> reset connection */
252 if (mandatory)
253 goto out_invalid_option;
254
255 return 0;
256
257 out_invalid_option:
258 DCCP_INC_STATS_BH(DCCP_MIB_INVALIDOPT);
259 DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_OPTION_ERROR;
260 pr_info("DCCP(%p): invalid option %d, len=%d\n", sk, opt, len);
261 return -1;
262 }
263
264 EXPORT_SYMBOL_GPL(dccp_parse_options);
265
266 static void dccp_encode_value_var(const u32 value, unsigned char *to,
267 const unsigned int len)
268 {
269 if (len > 3)
270 *to++ = (value & 0xFF000000) >> 24;
271 if (len > 2)
272 *to++ = (value & 0xFF0000) >> 16;
273 if (len > 1)
274 *to++ = (value & 0xFF00) >> 8;
275 if (len > 0)
276 *to++ = (value & 0xFF);
277 }
278
279 static inline int dccp_ndp_len(const int ndp)
280 {
281 return likely(ndp <= 0xFF) ? 1 : ndp <= 0xFFFF ? 2 : 3;
282 }
283
284 int dccp_insert_option(struct sock *sk, struct sk_buff *skb,
285 const unsigned char option,
286 const void *value, const unsigned char len)
287 {
288 unsigned char *to;
289
290 if (DCCP_SKB_CB(skb)->dccpd_opt_len + len + 2 > DCCP_MAX_OPT_LEN)
291 return -1;
292
293 DCCP_SKB_CB(skb)->dccpd_opt_len += len + 2;
294
295 to = skb_push(skb, len + 2);
296 *to++ = option;
297 *to++ = len + 2;
298
299 memcpy(to, value, len);
300 return 0;
301 }
302
303 EXPORT_SYMBOL_GPL(dccp_insert_option);
304
305 static int dccp_insert_option_ndp(struct sock *sk, struct sk_buff *skb)
306 {
307 struct dccp_sock *dp = dccp_sk(sk);
308 int ndp = dp->dccps_ndp_count;
309
310 if (dccp_non_data_packet(skb))
311 ++dp->dccps_ndp_count;
312 else
313 dp->dccps_ndp_count = 0;
314
315 if (ndp > 0) {
316 unsigned char *ptr;
317 const int ndp_len = dccp_ndp_len(ndp);
318 const int len = ndp_len + 2;
319
320 if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
321 return -1;
322
323 DCCP_SKB_CB(skb)->dccpd_opt_len += len;
324
325 ptr = skb_push(skb, len);
326 *ptr++ = DCCPO_NDP_COUNT;
327 *ptr++ = len;
328 dccp_encode_value_var(ndp, ptr, ndp_len);
329 }
330
331 return 0;
332 }
333
334 static inline int dccp_elapsed_time_len(const u32 elapsed_time)
335 {
336 return elapsed_time == 0 ? 0 : elapsed_time <= 0xFFFF ? 2 : 4;
337 }
338
339 int dccp_insert_option_elapsed_time(struct sock *sk, struct sk_buff *skb,
340 u32 elapsed_time)
341 {
342 const int elapsed_time_len = dccp_elapsed_time_len(elapsed_time);
343 const int len = 2 + elapsed_time_len;
344 unsigned char *to;
345
346 if (elapsed_time_len == 0)
347 return 0;
348
349 if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
350 return -1;
351
352 DCCP_SKB_CB(skb)->dccpd_opt_len += len;
353
354 to = skb_push(skb, len);
355 *to++ = DCCPO_ELAPSED_TIME;
356 *to++ = len;
357
358 if (elapsed_time_len == 2) {
359 const __be16 var16 = htons((u16)elapsed_time);
360 memcpy(to, &var16, 2);
361 } else {
362 const __be32 var32 = htonl(elapsed_time);
363 memcpy(to, &var32, 4);
364 }
365
366 return 0;
367 }
368
369 EXPORT_SYMBOL_GPL(dccp_insert_option_elapsed_time);
370
371 void dccp_timestamp(const struct sock *sk, struct timeval *tv)
372 {
373 const struct dccp_sock *dp = dccp_sk(sk);
374
375 do_gettimeofday(tv);
376 tv->tv_sec -= dp->dccps_epoch.tv_sec;
377 tv->tv_usec -= dp->dccps_epoch.tv_usec;
378
379 while (tv->tv_usec < 0) {
380 tv->tv_sec--;
381 tv->tv_usec += USEC_PER_SEC;
382 }
383 }
384
385 EXPORT_SYMBOL_GPL(dccp_timestamp);
386
387 int dccp_insert_option_timestamp(struct sock *sk, struct sk_buff *skb)
388 {
389 struct timeval tv;
390 __be32 now;
391
392 dccp_timestamp(sk, &tv);
393 now = htonl(timeval_usecs(&tv) / 10);
394 /* yes this will overflow but that is the point as we want a
395 * 10 usec 32 bit timer which mean it wraps every 11.9 hours */
396
397 return dccp_insert_option(sk, skb, DCCPO_TIMESTAMP, &now, sizeof(now));
398 }
399
400 EXPORT_SYMBOL_GPL(dccp_insert_option_timestamp);
401
402 static int dccp_insert_option_timestamp_echo(struct sock *sk,
403 struct sk_buff *skb)
404 {
405 struct dccp_sock *dp = dccp_sk(sk);
406 struct timeval now;
407 __be32 tstamp_echo;
408 u32 elapsed_time;
409 int len, elapsed_time_len;
410 unsigned char *to;
411
412 dccp_timestamp(sk, &now);
413 elapsed_time = timeval_delta(&now, &dp->dccps_timestamp_time) / 10;
414 elapsed_time_len = dccp_elapsed_time_len(elapsed_time);
415 len = 6 + elapsed_time_len;
416
417 if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
418 return -1;
419
420 DCCP_SKB_CB(skb)->dccpd_opt_len += len;
421
422 to = skb_push(skb, len);
423 *to++ = DCCPO_TIMESTAMP_ECHO;
424 *to++ = len;
425
426 tstamp_echo = htonl(dp->dccps_timestamp_echo);
427 memcpy(to, &tstamp_echo, 4);
428 to += 4;
429
430 if (elapsed_time_len == 2) {
431 const __be16 var16 = htons((u16)elapsed_time);
432 memcpy(to, &var16, 2);
433 } else if (elapsed_time_len == 4) {
434 const __be32 var32 = htonl(elapsed_time);
435 memcpy(to, &var32, 4);
436 }
437
438 dp->dccps_timestamp_echo = 0;
439 dp->dccps_timestamp_time.tv_sec = 0;
440 dp->dccps_timestamp_time.tv_usec = 0;
441 return 0;
442 }
443
444 static int dccp_insert_feat_opt(struct sk_buff *skb, u8 type, u8 feat,
445 u8 *val, u8 len)
446 {
447 u8 *to;
448
449 if (DCCP_SKB_CB(skb)->dccpd_opt_len + len + 3 > DCCP_MAX_OPT_LEN) {
450 LIMIT_NETDEBUG(KERN_INFO "DCCP: packet too small"
451 " to insert feature %d option!\n", feat);
452 return -1;
453 }
454
455 DCCP_SKB_CB(skb)->dccpd_opt_len += len + 3;
456
457 to = skb_push(skb, len + 3);
458 *to++ = type;
459 *to++ = len + 3;
460 *to++ = feat;
461
462 if (len)
463 memcpy(to, val, len);
464
465 dccp_pr_debug("%s(%s (%d), ...), length %d\n",
466 dccp_feat_typename(type),
467 dccp_feat_name(feat), feat, len);
468 return 0;
469 }
470
471 static int dccp_insert_options_feat(struct sock *sk, struct sk_buff *skb)
472 {
473 struct dccp_sock *dp = dccp_sk(sk);
474 struct dccp_minisock *dmsk = dccp_msk(sk);
475 struct dccp_opt_pend *opt, *next;
476 int change = 0;
477
478 /* confirm any options [NN opts] */
479 list_for_each_entry_safe(opt, next, &dmsk->dccpms_conf, dccpop_node) {
480 dccp_insert_feat_opt(skb, opt->dccpop_type,
481 opt->dccpop_feat, opt->dccpop_val,
482 opt->dccpop_len);
483 /* fear empty confirms */
484 if (opt->dccpop_val)
485 kfree(opt->dccpop_val);
486 kfree(opt);
487 }
488 INIT_LIST_HEAD(&dmsk->dccpms_conf);
489
490 /* see which features we need to send */
491 list_for_each_entry(opt, &dmsk->dccpms_pending, dccpop_node) {
492 /* see if we need to send any confirm */
493 if (opt->dccpop_sc) {
494 dccp_insert_feat_opt(skb, opt->dccpop_type + 1,
495 opt->dccpop_feat,
496 opt->dccpop_sc->dccpoc_val,
497 opt->dccpop_sc->dccpoc_len);
498
499 BUG_ON(!opt->dccpop_sc->dccpoc_val);
500 kfree(opt->dccpop_sc->dccpoc_val);
501 kfree(opt->dccpop_sc);
502 opt->dccpop_sc = NULL;
503 }
504
505 /* any option not confirmed, re-send it */
506 if (!opt->dccpop_conf) {
507 dccp_insert_feat_opt(skb, opt->dccpop_type,
508 opt->dccpop_feat, opt->dccpop_val,
509 opt->dccpop_len);
510 change++;
511 }
512 }
513
514 /* Retransmit timer.
515 * If this is the master listening sock, we don't set a timer on it. It
516 * should be fine because if the dude doesn't receive our RESPONSE
517 * [which will contain the CHANGE] he will send another REQUEST which
518 * will "retrnasmit" the change.
519 */
520 if (change && dp->dccps_role != DCCP_ROLE_LISTEN) {
521 dccp_pr_debug("reset feat negotiation timer %p\n", sk);
522
523 /* XXX don't reset the timer on re-transmissions. I.e. reset it
524 * only when sending new stuff i guess. Currently the timer
525 * never backs off because on re-transmission it just resets it!
526 */
527 inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
528 inet_csk(sk)->icsk_rto, DCCP_RTO_MAX);
529 }
530
531 return 0;
532 }
533
534 int dccp_insert_options(struct sock *sk, struct sk_buff *skb)
535 {
536 struct dccp_sock *dp = dccp_sk(sk);
537 struct dccp_minisock *dmsk = dccp_msk(sk);
538
539 DCCP_SKB_CB(skb)->dccpd_opt_len = 0;
540
541 if (dmsk->dccpms_send_ndp_count &&
542 dccp_insert_option_ndp(sk, skb))
543 return -1;
544
545 if (!dccp_packet_without_ack(skb)) {
546 if (dmsk->dccpms_send_ack_vector &&
547 dccp_ackvec_pending(dp->dccps_hc_rx_ackvec) &&
548 dccp_insert_option_ackvec(sk, skb))
549 return -1;
550
551 if (dp->dccps_timestamp_echo != 0 &&
552 dccp_insert_option_timestamp_echo(sk, skb))
553 return -1;
554 }
555
556 if (dp->dccps_hc_rx_insert_options) {
557 if (ccid_hc_rx_insert_options(dp->dccps_hc_rx_ccid, sk, skb))
558 return -1;
559 dp->dccps_hc_rx_insert_options = 0;
560 }
561 if (dp->dccps_hc_tx_insert_options) {
562 if (ccid_hc_tx_insert_options(dp->dccps_hc_tx_ccid, sk, skb))
563 return -1;
564 dp->dccps_hc_tx_insert_options = 0;
565 }
566
567 /* Feature negotiation */
568 /* Data packets can't do feat negotiation */
569 if (DCCP_SKB_CB(skb)->dccpd_type != DCCP_PKT_DATA &&
570 DCCP_SKB_CB(skb)->dccpd_type != DCCP_PKT_DATAACK &&
571 dccp_insert_options_feat(sk, skb))
572 return -1;
573
574 /* XXX: insert other options when appropriate */
575
576 if (DCCP_SKB_CB(skb)->dccpd_opt_len != 0) {
577 /* The length of all options has to be a multiple of 4 */
578 int padding = DCCP_SKB_CB(skb)->dccpd_opt_len % 4;
579
580 if (padding != 0) {
581 padding = 4 - padding;
582 memset(skb_push(skb, padding), 0, padding);
583 DCCP_SKB_CB(skb)->dccpd_opt_len += padding;
584 }
585 }
586
587 return 0;
588 }
AMDTP streaming driver for the Linux FireWire stack (Juju)