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[TFRC]: New rx history code
[linux-2.6/x86.git] / net / dccp / options.c
blob523250b45ea5be66220791a0ef72ac75a3ed1356
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 <asm/unaligned.h>
18 #include <linux/kernel.h>
19 #include <linux/skbuff.h>
20
21 #include "ackvec.h"
22 #include "ccid.h"
23 #include "dccp.h"
24 #include "feat.h"
25
26 int sysctl_dccp_feat_sequence_window = DCCPF_INITIAL_SEQUENCE_WINDOW;
27 int sysctl_dccp_feat_rx_ccid = DCCPF_INITIAL_CCID;
28 int sysctl_dccp_feat_tx_ccid = DCCPF_INITIAL_CCID;
29 int sysctl_dccp_feat_ack_ratio = DCCPF_INITIAL_ACK_RATIO;
30 int sysctl_dccp_feat_send_ack_vector = DCCPF_INITIAL_SEND_ACK_VECTOR;
31 int sysctl_dccp_feat_send_ndp_count = DCCPF_INITIAL_SEND_NDP_COUNT;
32
33 static u32 dccp_decode_value_var(const unsigned char *bf, const u8 len)
34 {
35 u32 value = 0;
36
37 if (len > 3)
38 value += *bf++ << 24;
39 if (len > 2)
40 value += *bf++ << 16;
41 if (len > 1)
42 value += *bf++ << 8;
43 if (len > 0)
44 value += *bf;
45
46 return value;
47 }
48
49 int dccp_parse_options(struct sock *sk, struct sk_buff *skb)
50 {
51 struct dccp_sock *dp = dccp_sk(sk);
52 const struct dccp_hdr *dh = dccp_hdr(skb);
53 const u8 pkt_type = DCCP_SKB_CB(skb)->dccpd_type;
54 u64 ackno = DCCP_SKB_CB(skb)->dccpd_ack_seq;
55 unsigned char *options = (unsigned char *)dh + dccp_hdr_len(skb);
56 unsigned char *opt_ptr = options;
57 const unsigned char *opt_end = (unsigned char *)dh +
58 (dh->dccph_doff * 4);
59 struct dccp_options_received *opt_recv = &dp->dccps_options_received;
60 unsigned char opt, len;
61 unsigned char *value;
62 u32 elapsed_time;
63 __be32 opt_val;
64 int rc;
65 int mandatory = 0;
66
67 memset(opt_recv, 0, sizeof(*opt_recv));
68
69 opt = len = 0;
70 while (opt_ptr != opt_end) {
71 opt = *opt_ptr++;
72 len = 0;
73 value = NULL;
74
75 /* Check if this isn't a single byte option */
76 if (opt > DCCPO_MAX_RESERVED) {
77 if (opt_ptr == opt_end)
78 goto out_invalid_option;
79
80 len = *opt_ptr++;
81 if (len < 3)
82 goto out_invalid_option;
83 /*
84 * Remove the type and len fields, leaving
85 * just the value size
86 */
87 len -= 2;
88 value = opt_ptr;
89 opt_ptr += len;
90
91 if (opt_ptr > opt_end)
92 goto out_invalid_option;
93 }
94
95 switch (opt) {
96 case DCCPO_PADDING:
97 break;
98 case DCCPO_MANDATORY:
99 if (mandatory)
100 goto out_invalid_option;
101 if (pkt_type != DCCP_PKT_DATA)
102 mandatory = 1;
103 break;
104 case DCCPO_NDP_COUNT:
105 if (len > 3)
106 goto out_invalid_option;
107
108 opt_recv->dccpor_ndp = dccp_decode_value_var(value, len);
109 dccp_pr_debug("%s rx opt: NDP count=%d\n", dccp_role(sk),
110 opt_recv->dccpor_ndp);
111 break;
112 case DCCPO_CHANGE_L:
113 /* fall through */
114 case DCCPO_CHANGE_R:
115 if (len < 2)
116 goto out_invalid_option;
117 rc = dccp_feat_change_recv(sk, opt, *value, value + 1,
118 len - 1);
119 /*
120 * When there is a change error, change_recv is
121 * responsible for dealing with it. i.e. reply with an
122 * empty confirm.
123 * If the change was mandatory, then we need to die.
124 */
125 if (rc && mandatory)
126 goto out_invalid_option;
127 break;
128 case DCCPO_CONFIRM_L:
129 /* fall through */
130 case DCCPO_CONFIRM_R:
131 if (len < 2)
132 goto out_invalid_option;
133 if (dccp_feat_confirm_recv(sk, opt, *value,
134 value + 1, len - 1))
135 goto out_invalid_option;
136 break;
137 case DCCPO_ACK_VECTOR_0:
138 case DCCPO_ACK_VECTOR_1:
139 if (dccp_packet_without_ack(skb)) /* RFC 4340, 11.4 */
140 break;
141
142 if (dccp_msk(sk)->dccpms_send_ack_vector &&
143 dccp_ackvec_parse(sk, skb, &ackno, opt, value, len))
144 goto out_invalid_option;
145 break;
146 case DCCPO_TIMESTAMP:
147 if (len != 4)
148 goto out_invalid_option;
149
150 opt_val = get_unaligned((__be32 *)value);
151 opt_recv->dccpor_timestamp = ntohl(opt_val);
152
153 dp->dccps_timestamp_echo = opt_recv->dccpor_timestamp;
154 dp->dccps_timestamp_time = ktime_get_real();
155
156 dccp_pr_debug("%s rx opt: TIMESTAMP=%u, ackno=%llu\n",
157 dccp_role(sk), opt_recv->dccpor_timestamp,
158 (unsigned long long)
159 DCCP_SKB_CB(skb)->dccpd_ack_seq);
160 break;
161 case DCCPO_TIMESTAMP_ECHO:
162 if (len != 4 && len != 6 && len != 8)
163 goto out_invalid_option;
164
165 opt_val = get_unaligned((__be32 *)value);
166 opt_recv->dccpor_timestamp_echo = ntohl(opt_val);
167
168 dccp_pr_debug("%s rx opt: TIMESTAMP_ECHO=%u, len=%d, "
169 "ackno=%llu", dccp_role(sk),
170 opt_recv->dccpor_timestamp_echo,
171 len + 2,
172 (unsigned long long)
173 DCCP_SKB_CB(skb)->dccpd_ack_seq);
174
175 value += 4;
176
177 if (len == 4) { /* no elapsed time included */
178 dccp_pr_debug_cat("\n");
179 break;
180 }
181
182 if (len == 6) { /* 2-byte elapsed time */
183 __be16 opt_val2 = get_unaligned((__be16 *)value);
184 elapsed_time = ntohs(opt_val2);
185 } else { /* 4-byte elapsed time */
186 opt_val = get_unaligned((__be32 *)value);
187 elapsed_time = ntohl(opt_val);
188 }
189
190 dccp_pr_debug_cat(", ELAPSED_TIME=%u\n", elapsed_time);
191
192 /* Give precedence to the biggest ELAPSED_TIME */
193 if (elapsed_time > opt_recv->dccpor_elapsed_time)
194 opt_recv->dccpor_elapsed_time = elapsed_time;
195 break;
196 case DCCPO_ELAPSED_TIME:
197 if (dccp_packet_without_ack(skb)) /* RFC 4340, 13.2 */
198 break;
199
200 if (len == 2) {
201 __be16 opt_val2 = get_unaligned((__be16 *)value);
202 elapsed_time = ntohs(opt_val2);
203 } else if (len == 4) {
204 opt_val = get_unaligned((__be32 *)value);
205 elapsed_time = ntohl(opt_val);
206 } else {
207 goto out_invalid_option;
208 }
209
210 if (elapsed_time > opt_recv->dccpor_elapsed_time)
211 opt_recv->dccpor_elapsed_time = elapsed_time;
212
213 dccp_pr_debug("%s rx opt: ELAPSED_TIME=%d\n",
214 dccp_role(sk), elapsed_time);
215 break;
216 /*
217 * From RFC 4340, sec. 10.3:
218 *
219 * Option numbers 128 through 191 are for
220 * options sent from the HC-Sender to the
221 * HC-Receiver; option numbers 192 through 255
222 * are for options sent from the HC-Receiver to
223 * the HC-Sender.
224 */
225 case 128 ... 191: {
226 const u16 idx = value - options;
227
228 if (ccid_hc_rx_parse_options(dp->dccps_hc_rx_ccid, sk,
229 opt, len, idx,
230 value) != 0)
231 goto out_invalid_option;
232 }
233 break;
234 case 192 ... 255: {
235 const u16 idx = value - options;
236
237 if (ccid_hc_tx_parse_options(dp->dccps_hc_tx_ccid, sk,
238 opt, len, idx,
239 value) != 0)
240 goto out_invalid_option;
241 }
242 break;
243 default:
244 DCCP_CRIT("DCCP(%p): option %d(len=%d) not "
245 "implemented, ignoring", sk, opt, len);
246 break;
247 }
248
249 if (opt != DCCPO_MANDATORY)
250 mandatory = 0;
251 }
252
253 /* mandatory was the last byte in option list -> reset connection */
254 if (mandatory)
255 goto out_invalid_option;
256
257 return 0;
258
259 out_invalid_option:
260 DCCP_INC_STATS_BH(DCCP_MIB_INVALIDOPT);
261 DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_OPTION_ERROR;
262 DCCP_WARN("DCCP(%p): invalid option %d, len=%d", sk, opt, len);
263 return -1;
264 }
265
266 EXPORT_SYMBOL_GPL(dccp_parse_options);
267
268 static void dccp_encode_value_var(const u32 value, unsigned char *to,
269 const unsigned int len)
270 {
271 if (len > 3)
272 *to++ = (value & 0xFF000000) >> 24;
273 if (len > 2)
274 *to++ = (value & 0xFF0000) >> 16;
275 if (len > 1)
276 *to++ = (value & 0xFF00) >> 8;
277 if (len > 0)
278 *to++ = (value & 0xFF);
279 }
280
281 static inline int dccp_ndp_len(const int ndp)
282 {
283 return likely(ndp <= 0xFF) ? 1 : ndp <= 0xFFFF ? 2 : 3;
284 }
285
286 int dccp_insert_option(struct sock *sk, struct sk_buff *skb,
287 const unsigned char option,
288 const void *value, const unsigned char len)
289 {
290 unsigned char *to;
291
292 if (DCCP_SKB_CB(skb)->dccpd_opt_len + len + 2 > DCCP_MAX_OPT_LEN)
293 return -1;
294
295 DCCP_SKB_CB(skb)->dccpd_opt_len += len + 2;
296
297 to = skb_push(skb, len + 2);
298 *to++ = option;
299 *to++ = len + 2;
300
301 memcpy(to, value, len);
302 return 0;
303 }
304
305 EXPORT_SYMBOL_GPL(dccp_insert_option);
306
307 static int dccp_insert_option_ndp(struct sock *sk, struct sk_buff *skb)
308 {
309 struct dccp_sock *dp = dccp_sk(sk);
310 int ndp = dp->dccps_ndp_count;
311
312 if (dccp_non_data_packet(skb))
313 ++dp->dccps_ndp_count;
314 else
315 dp->dccps_ndp_count = 0;
316
317 if (ndp > 0) {
318 unsigned char *ptr;
319 const int ndp_len = dccp_ndp_len(ndp);
320 const int len = ndp_len + 2;
321
322 if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
323 return -1;
324
325 DCCP_SKB_CB(skb)->dccpd_opt_len += len;
326
327 ptr = skb_push(skb, len);
328 *ptr++ = DCCPO_NDP_COUNT;
329 *ptr++ = len;
330 dccp_encode_value_var(ndp, ptr, ndp_len);
331 }
332
333 return 0;
334 }
335
336 static inline int dccp_elapsed_time_len(const u32 elapsed_time)
337 {
338 return elapsed_time == 0 ? 0 : elapsed_time <= 0xFFFF ? 2 : 4;
339 }
340
341 int dccp_insert_option_elapsed_time(struct sock *sk, struct sk_buff *skb,
342 u32 elapsed_time)
343 {
344 const int elapsed_time_len = dccp_elapsed_time_len(elapsed_time);
345 const int len = 2 + elapsed_time_len;
346 unsigned char *to;
347
348 if (elapsed_time_len == 0)
349 return 0;
350
351 if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
352 return -1;
353
354 DCCP_SKB_CB(skb)->dccpd_opt_len += len;
355
356 to = skb_push(skb, len);
357 *to++ = DCCPO_ELAPSED_TIME;
358 *to++ = len;
359
360 if (elapsed_time_len == 2) {
361 const __be16 var16 = htons((u16)elapsed_time);
362 memcpy(to, &var16, 2);
363 } else {
364 const __be32 var32 = htonl(elapsed_time);
365 memcpy(to, &var32, 4);
366 }
367
368 return 0;
369 }
370
371 EXPORT_SYMBOL_GPL(dccp_insert_option_elapsed_time);
372
373 int dccp_insert_option_timestamp(struct sock *sk, struct sk_buff *skb)
374 {
375 __be32 now = htonl(dccp_timestamp());
376 /* yes this will overflow but that is the point as we want a
377 * 10 usec 32 bit timer which mean it wraps every 11.9 hours */
378
379 return dccp_insert_option(sk, skb, DCCPO_TIMESTAMP, &now, sizeof(now));
380 }
381
382 EXPORT_SYMBOL_GPL(dccp_insert_option_timestamp);
383
384 static int dccp_insert_option_timestamp_echo(struct sock *sk,
385 struct sk_buff *skb)
386 {
387 struct dccp_sock *dp = dccp_sk(sk);
388 __be32 tstamp_echo;
389 int len, elapsed_time_len;
390 unsigned char *to;
391 const suseconds_t delta = ktime_us_delta(ktime_get_real(),
392 dp->dccps_timestamp_time);
393 u32 elapsed_time = delta / 10;
394 elapsed_time_len = dccp_elapsed_time_len(elapsed_time);
395 len = 6 + elapsed_time_len;
396
397 if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
398 return -1;
399
400 DCCP_SKB_CB(skb)->dccpd_opt_len += len;
401
402 to = skb_push(skb, len);
403 *to++ = DCCPO_TIMESTAMP_ECHO;
404 *to++ = len;
405
406 tstamp_echo = htonl(dp->dccps_timestamp_echo);
407 memcpy(to, &tstamp_echo, 4);
408 to += 4;
409
410 if (elapsed_time_len == 2) {
411 const __be16 var16 = htons((u16)elapsed_time);
412 memcpy(to, &var16, 2);
413 } else if (elapsed_time_len == 4) {
414 const __be32 var32 = htonl(elapsed_time);
415 memcpy(to, &var32, 4);
416 }
417
418 dp->dccps_timestamp_echo = 0;
419 dp->dccps_timestamp_time = ktime_set(0, 0);
420 return 0;
421 }
422
423 static int dccp_insert_feat_opt(struct sk_buff *skb, u8 type, u8 feat,
424 u8 *val, u8 len)
425 {
426 u8 *to;
427
428 if (DCCP_SKB_CB(skb)->dccpd_opt_len + len + 3 > DCCP_MAX_OPT_LEN) {
429 DCCP_WARN("packet too small for feature %d option!\n", feat);
430 return -1;
431 }
432
433 DCCP_SKB_CB(skb)->dccpd_opt_len += len + 3;
434
435 to = skb_push(skb, len + 3);
436 *to++ = type;
437 *to++ = len + 3;
438 *to++ = feat;
439
440 if (len)
441 memcpy(to, val, len);
442
443 dccp_pr_debug("%s(%s (%d), ...), length %d\n",
444 dccp_feat_typename(type),
445 dccp_feat_name(feat), feat, len);
446 return 0;
447 }
448
449 static int dccp_insert_options_feat(struct sock *sk, struct sk_buff *skb)
450 {
451 struct dccp_sock *dp = dccp_sk(sk);
452 struct dccp_minisock *dmsk = dccp_msk(sk);
453 struct dccp_opt_pend *opt, *next;
454 int change = 0;
455
456 /* confirm any options [NN opts] */
457 list_for_each_entry_safe(opt, next, &dmsk->dccpms_conf, dccpop_node) {
458 dccp_insert_feat_opt(skb, opt->dccpop_type,
459 opt->dccpop_feat, opt->dccpop_val,
460 opt->dccpop_len);
461 /* fear empty confirms */
462 if (opt->dccpop_val)
463 kfree(opt->dccpop_val);
464 kfree(opt);
465 }
466 INIT_LIST_HEAD(&dmsk->dccpms_conf);
467
468 /* see which features we need to send */
469 list_for_each_entry(opt, &dmsk->dccpms_pending, dccpop_node) {
470 /* see if we need to send any confirm */
471 if (opt->dccpop_sc) {
472 dccp_insert_feat_opt(skb, opt->dccpop_type + 1,
473 opt->dccpop_feat,
474 opt->dccpop_sc->dccpoc_val,
475 opt->dccpop_sc->dccpoc_len);
476
477 BUG_ON(!opt->dccpop_sc->dccpoc_val);
478 kfree(opt->dccpop_sc->dccpoc_val);
479 kfree(opt->dccpop_sc);
480 opt->dccpop_sc = NULL;
481 }
482
483 /* any option not confirmed, re-send it */
484 if (!opt->dccpop_conf) {
485 dccp_insert_feat_opt(skb, opt->dccpop_type,
486 opt->dccpop_feat, opt->dccpop_val,
487 opt->dccpop_len);
488 change++;
489 }
490 }
491
492 /* Retransmit timer.
493 * If this is the master listening sock, we don't set a timer on it. It
494 * should be fine because if the dude doesn't receive our RESPONSE
495 * [which will contain the CHANGE] he will send another REQUEST which
496 * will "retrnasmit" the change.
497 */
498 if (change && dp->dccps_role != DCCP_ROLE_LISTEN) {
499 dccp_pr_debug("reset feat negotiation timer %p\n", sk);
500
501 /* XXX don't reset the timer on re-transmissions. I.e. reset it
502 * only when sending new stuff i guess. Currently the timer
503 * never backs off because on re-transmission it just resets it!
504 */
505 inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
506 inet_csk(sk)->icsk_rto, DCCP_RTO_MAX);
507 }
508
509 return 0;
510 }
511
512 int dccp_insert_options(struct sock *sk, struct sk_buff *skb)
513 {
514 struct dccp_sock *dp = dccp_sk(sk);
515 struct dccp_minisock *dmsk = dccp_msk(sk);
516
517 DCCP_SKB_CB(skb)->dccpd_opt_len = 0;
518
519 if (dmsk->dccpms_send_ndp_count &&
520 dccp_insert_option_ndp(sk, skb))
521 return -1;
522
523 if (!dccp_packet_without_ack(skb)) {
524 if (dmsk->dccpms_send_ack_vector &&
525 dccp_ackvec_pending(dp->dccps_hc_rx_ackvec) &&
526 dccp_insert_option_ackvec(sk, skb))
527 return -1;
528
529 if (dp->dccps_timestamp_echo != 0 &&
530 dccp_insert_option_timestamp_echo(sk, skb))
531 return -1;
532 }
533
534 if (dp->dccps_hc_rx_insert_options) {
535 if (ccid_hc_rx_insert_options(dp->dccps_hc_rx_ccid, sk, skb))
536 return -1;
537 dp->dccps_hc_rx_insert_options = 0;
538 }
539
540 /* Feature negotiation */
541 /* Data packets can't do feat negotiation */
542 if (DCCP_SKB_CB(skb)->dccpd_type != DCCP_PKT_DATA &&
543 DCCP_SKB_CB(skb)->dccpd_type != DCCP_PKT_DATAACK &&
544 dccp_insert_options_feat(sk, skb))
545 return -1;
546
547 /*
548 * Obtain RTT sample from Request/Response exchange.
549 * This is currently used in CCID 3 initialisation.
550 */
551 if (DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_REQUEST &&
552 dccp_insert_option_timestamp(sk, skb))
553 return -1;
554
555 /* XXX: insert other options when appropriate */
556
557 if (DCCP_SKB_CB(skb)->dccpd_opt_len != 0) {
558 /* The length of all options has to be a multiple of 4 */
559 int padding = DCCP_SKB_CB(skb)->dccpd_opt_len % 4;
560
561 if (padding != 0) {
562 padding = 4 - padding;
563 memset(skb_push(skb, padding), 0, padding);
564 DCCP_SKB_CB(skb)->dccpd_opt_len += padding;
565 }
566 }
567
568 return 0;
569 }
x86 "subsystem" repository