?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
[ARM] 3487/1: IXP4xx: Support non-PCI systems
[linux-2.6/mini2440.git] / net / dccp / options.c
blobe9feb2a0c7706ef1a464d3d7428dac77cc36013d
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 <iam4@cs.waikato.ac.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/config.h>
15 #include <linux/dccp.h>
16 #include <linux/module.h>
17 #include <linux/types.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 dccp_feat_default_sequence_window = DCCPF_INITIAL_SEQUENCE_WINDOW;
27 int dccp_feat_default_rx_ccid = DCCPF_INITIAL_CCID;
28 int dccp_feat_default_tx_ccid = DCCPF_INITIAL_CCID;
29 int dccp_feat_default_ack_ratio = DCCPF_INITIAL_ACK_RATIO;
30 int dccp_feat_default_send_ack_vector = DCCPF_INITIAL_SEND_ACK_VECTOR;
31 int dccp_feat_default_send_ndp_count = DCCPF_INITIAL_SEND_NDP_COUNT;
32
33 void dccp_minisock_init(struct dccp_minisock *dmsk)
34 {
35 dmsk->dccpms_sequence_window = dccp_feat_default_sequence_window;
36 dmsk->dccpms_rx_ccid = dccp_feat_default_rx_ccid;
37 dmsk->dccpms_tx_ccid = dccp_feat_default_tx_ccid;
38 dmsk->dccpms_ack_ratio = dccp_feat_default_ack_ratio;
39 dmsk->dccpms_send_ack_vector = dccp_feat_default_send_ack_vector;
40 dmsk->dccpms_send_ndp_count = dccp_feat_default_send_ndp_count;
41 }
42
43 static u32 dccp_decode_value_var(const unsigned char *bf, const u8 len)
44 {
45 u32 value = 0;
46
47 if (len > 3)
48 value += *bf++ << 24;
49 if (len > 2)
50 value += *bf++ << 16;
51 if (len > 1)
52 value += *bf++ << 8;
53 if (len > 0)
54 value += *bf;
55
56 return value;
57 }
58
59 int dccp_parse_options(struct sock *sk, struct sk_buff *skb)
60 {
61 struct dccp_sock *dp = dccp_sk(sk);
62 #ifdef CONFIG_IP_DCCP_DEBUG
63 const char *debug_prefix = dp->dccps_role == DCCP_ROLE_CLIENT ?
64 "CLIENT rx opt: " : "server rx opt: ";
65 #endif
66 const struct dccp_hdr *dh = dccp_hdr(skb);
67 const u8 pkt_type = DCCP_SKB_CB(skb)->dccpd_type;
68 unsigned char *options = (unsigned char *)dh + dccp_hdr_len(skb);
69 unsigned char *opt_ptr = options;
70 const unsigned char *opt_end = (unsigned char *)dh +
71 (dh->dccph_doff * 4);
72 struct dccp_options_received *opt_recv = &dp->dccps_options_received;
73 unsigned char opt, len;
74 unsigned char *value;
75 u32 elapsed_time;
76 int rc;
77 int mandatory = 0;
78
79 memset(opt_recv, 0, sizeof(*opt_recv));
80
81 opt = len = 0;
82 while (opt_ptr != opt_end) {
83 opt = *opt_ptr++;
84 len = 0;
85 value = NULL;
86
87 /* Check if this isn't a single byte option */
88 if (opt > DCCPO_MAX_RESERVED) {
89 if (opt_ptr == opt_end)
90 goto out_invalid_option;
91
92 len = *opt_ptr++;
93 if (len < 3)
94 goto out_invalid_option;
95 /*
96 * Remove the type and len fields, leaving
97 * just the value size
98 */
99 len -= 2;
100 value = opt_ptr;
101 opt_ptr += len;
102
103 if (opt_ptr > opt_end)
104 goto out_invalid_option;
105 }
106
107 switch (opt) {
108 case DCCPO_PADDING:
109 break;
110 case DCCPO_MANDATORY:
111 if (mandatory)
112 goto out_invalid_option;
113 if (pkt_type != DCCP_PKT_DATA)
114 mandatory = 1;
115 break;
116 case DCCPO_NDP_COUNT:
117 if (len > 3)
118 goto out_invalid_option;
119
120 opt_recv->dccpor_ndp = dccp_decode_value_var(value, len);
121 dccp_pr_debug("%sNDP count=%d\n", debug_prefix,
122 opt_recv->dccpor_ndp);
123 break;
124 case DCCPO_CHANGE_L:
125 /* fall through */
126 case DCCPO_CHANGE_R:
127 if (len < 2)
128 goto out_invalid_option;
129 rc = dccp_feat_change_recv(sk, opt, *value, value + 1,
130 len - 1);
131 /*
132 * When there is a change error, change_recv is
133 * responsible for dealing with it. i.e. reply with an
134 * empty confirm.
135 * If the change was mandatory, then we need to die.
136 */
137 if (rc && mandatory)
138 goto out_invalid_option;
139 break;
140 case DCCPO_CONFIRM_L:
141 /* fall through */
142 case DCCPO_CONFIRM_R:
143 if (len < 2)
144 goto out_invalid_option;
145 if (dccp_feat_confirm_recv(sk, opt, *value,
146 value + 1, len - 1))
147 goto out_invalid_option;
148 break;
149 case DCCPO_ACK_VECTOR_0:
150 case DCCPO_ACK_VECTOR_1:
151 if (pkt_type == DCCP_PKT_DATA)
152 break;
153
154 if (dccp_msk(sk)->dccpms_send_ack_vector &&
155 dccp_ackvec_parse(sk, skb, opt, value, len))
156 goto out_invalid_option;
157 break;
158 case DCCPO_TIMESTAMP:
159 if (len != 4)
160 goto out_invalid_option;
161
162 opt_recv->dccpor_timestamp = ntohl(*(__be32 *)value);
163
164 dp->dccps_timestamp_echo = opt_recv->dccpor_timestamp;
165 dccp_timestamp(sk, &dp->dccps_timestamp_time);
166
167 dccp_pr_debug("%sTIMESTAMP=%u, ackno=%llu\n",
168 debug_prefix, opt_recv->dccpor_timestamp,
169 (unsigned long long)
170 DCCP_SKB_CB(skb)->dccpd_ack_seq);
171 break;
172 case DCCPO_TIMESTAMP_ECHO:
173 if (len != 4 && len != 6 && len != 8)
174 goto out_invalid_option;
175
176 opt_recv->dccpor_timestamp_echo = ntohl(*(__be32 *)value);
177
178 dccp_pr_debug("%sTIMESTAMP_ECHO=%u, len=%d, ackno=%llu, ",
179 debug_prefix,
180 opt_recv->dccpor_timestamp_echo,
181 len + 2,
182 (unsigned long long)
183 DCCP_SKB_CB(skb)->dccpd_ack_seq);
184
185
186 if (len == 4)
187 break;
188
189 if (len == 6)
190 elapsed_time = ntohs(*(__be16 *)(value + 4));
191 else
192 elapsed_time = ntohl(*(__be32 *)(value + 4));
193
194 /* Give precedence to the biggest ELAPSED_TIME */
195 if (elapsed_time > opt_recv->dccpor_elapsed_time)
196 opt_recv->dccpor_elapsed_time = elapsed_time;
197 break;
198 case DCCPO_ELAPSED_TIME:
199 if (len != 2 && len != 4)
200 goto out_invalid_option;
201
202 if (pkt_type == DCCP_PKT_DATA)
203 continue;
204
205 if (len == 2)
206 elapsed_time = ntohs(*(__be16 *)value);
207 else
208 elapsed_time = ntohl(*(__be32 *)value);
209
210 if (elapsed_time > opt_recv->dccpor_elapsed_time)
211 opt_recv->dccpor_elapsed_time = elapsed_time;
212
213 dccp_pr_debug("%sELAPSED_TIME=%d\n", debug_prefix,
214 elapsed_time);
215 break;
216 /*
217 * From draft-ietf-dccp-spec-11.txt:
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 pr_info("DCCP(%p): option %d(len=%d) not "
245 "implemented, ignoring\n",
246 sk, opt, len);
247 break;
248 }
249
250 if (opt != DCCPO_MANDATORY)
251 mandatory = 0;
252 }
253
254 /* mandatory was the last byte in option list -> reset connection */
255 if (mandatory)
256 goto out_invalid_option;
257
258 return 0;
259
260 out_invalid_option:
261 DCCP_INC_STATS_BH(DCCP_MIB_INVALIDOPT);
262 DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_OPTION_ERROR;
263 pr_info("DCCP(%p): invalid option %d, len=%d\n", sk, opt, len);
264 return -1;
265 }
266
267 EXPORT_SYMBOL_GPL(dccp_parse_options);
268
269 static void dccp_encode_value_var(const u32 value, unsigned char *to,
270 const unsigned int len)
271 {
272 if (len > 3)
273 *to++ = (value & 0xFF000000) >> 24;
274 if (len > 2)
275 *to++ = (value & 0xFF0000) >> 16;
276 if (len > 1)
277 *to++ = (value & 0xFF00) >> 8;
278 if (len > 0)
279 *to++ = (value & 0xFF);
280 }
281
282 static inline int dccp_ndp_len(const int ndp)
283 {
284 return likely(ndp <= 0xFF) ? 1 : ndp <= 0xFFFF ? 2 : 3;
285 }
286
287 int dccp_insert_option(struct sock *sk, struct sk_buff *skb,
288 const unsigned char option,
289 const void *value, const unsigned char len)
290 {
291 unsigned char *to;
292
293 if (DCCP_SKB_CB(skb)->dccpd_opt_len + len + 2 > DCCP_MAX_OPT_LEN)
294 return -1;
295
296 DCCP_SKB_CB(skb)->dccpd_opt_len += len + 2;
297
298 to = skb_push(skb, len + 2);
299 *to++ = option;
300 *to++ = len + 2;
301
302 memcpy(to, value, len);
303 return 0;
304 }
305
306 EXPORT_SYMBOL_GPL(dccp_insert_option);
307
308 static int dccp_insert_option_ndp(struct sock *sk, struct sk_buff *skb)
309 {
310 struct dccp_sock *dp = dccp_sk(sk);
311 int ndp = dp->dccps_ndp_count;
312
313 if (dccp_non_data_packet(skb))
314 ++dp->dccps_ndp_count;
315 else
316 dp->dccps_ndp_count = 0;
317
318 if (ndp > 0) {
319 unsigned char *ptr;
320 const int ndp_len = dccp_ndp_len(ndp);
321 const int len = ndp_len + 2;
322
323 if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
324 return -1;
325
326 DCCP_SKB_CB(skb)->dccpd_opt_len += len;
327
328 ptr = skb_push(skb, len);
329 *ptr++ = DCCPO_NDP_COUNT;
330 *ptr++ = len;
331 dccp_encode_value_var(ndp, ptr, ndp_len);
332 }
333
334 return 0;
335 }
336
337 static inline int dccp_elapsed_time_len(const u32 elapsed_time)
338 {
339 return elapsed_time == 0 ? 0 : elapsed_time <= 0xFFFF ? 2 : 4;
340 }
341
342 int dccp_insert_option_elapsed_time(struct sock *sk, struct sk_buff *skb,
343 u32 elapsed_time)
344 {
345 const int elapsed_time_len = dccp_elapsed_time_len(elapsed_time);
346 const int len = 2 + elapsed_time_len;
347 unsigned char *to;
348
349 if (elapsed_time_len == 0)
350 return 0;
351
352 if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
353 return -1;
354
355 DCCP_SKB_CB(skb)->dccpd_opt_len += len;
356
357 to = skb_push(skb, len);
358 *to++ = DCCPO_ELAPSED_TIME;
359 *to++ = len;
360
361 if (elapsed_time_len == 2) {
362 const __be16 var16 = htons((u16)elapsed_time);
363 memcpy(to, &var16, 2);
364 } else {
365 const __be32 var32 = htonl(elapsed_time);
366 memcpy(to, &var32, 4);
367 }
368
369 return 0;
370 }
371
372 EXPORT_SYMBOL_GPL(dccp_insert_option_elapsed_time);
373
374 void dccp_timestamp(const struct sock *sk, struct timeval *tv)
375 {
376 const struct dccp_sock *dp = dccp_sk(sk);
377
378 do_gettimeofday(tv);
379 tv->tv_sec -= dp->dccps_epoch.tv_sec;
380 tv->tv_usec -= dp->dccps_epoch.tv_usec;
381
382 while (tv->tv_usec < 0) {
383 tv->tv_sec--;
384 tv->tv_usec += USEC_PER_SEC;
385 }
386 }
387
388 EXPORT_SYMBOL_GPL(dccp_timestamp);
389
390 int dccp_insert_option_timestamp(struct sock *sk, struct sk_buff *skb)
391 {
392 struct timeval tv;
393 __be32 now;
394
395 dccp_timestamp(sk, &tv);
396 now = htonl(timeval_usecs(&tv) / 10);
397 /* yes this will overflow but that is the point as we want a
398 * 10 usec 32 bit timer which mean it wraps every 11.9 hours */
399
400 return dccp_insert_option(sk, skb, DCCPO_TIMESTAMP, &now, sizeof(now));
401 }
402
403 EXPORT_SYMBOL_GPL(dccp_insert_option_timestamp);
404
405 static int dccp_insert_option_timestamp_echo(struct sock *sk,
406 struct sk_buff *skb)
407 {
408 struct dccp_sock *dp = dccp_sk(sk);
409 struct timeval now;
410 __be32 tstamp_echo;
411 u32 elapsed_time;
412 int len, elapsed_time_len;
413 unsigned char *to;
414
415 dccp_timestamp(sk, &now);
416 elapsed_time = timeval_delta(&now, &dp->dccps_timestamp_time) / 10;
417 elapsed_time_len = dccp_elapsed_time_len(elapsed_time);
418 len = 6 + elapsed_time_len;
419
420 if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
421 return -1;
422
423 DCCP_SKB_CB(skb)->dccpd_opt_len += len;
424
425 to = skb_push(skb, len);
426 *to++ = DCCPO_TIMESTAMP_ECHO;
427 *to++ = len;
428
429 tstamp_echo = htonl(dp->dccps_timestamp_echo);
430 memcpy(to, &tstamp_echo, 4);
431 to += 4;
432
433 if (elapsed_time_len == 2) {
434 const __be16 var16 = htons((u16)elapsed_time);
435 memcpy(to, &var16, 2);
436 } else if (elapsed_time_len == 4) {
437 const __be32 var32 = htonl(elapsed_time);
438 memcpy(to, &var32, 4);
439 }
440
441 dp->dccps_timestamp_echo = 0;
442 dp->dccps_timestamp_time.tv_sec = 0;
443 dp->dccps_timestamp_time.tv_usec = 0;
444 return 0;
445 }
446
447 static int dccp_insert_feat_opt(struct sk_buff *skb, u8 type, u8 feat,
448 u8 *val, u8 len)
449 {
450 u8 *to;
451
452 if (DCCP_SKB_CB(skb)->dccpd_opt_len + len + 3 > DCCP_MAX_OPT_LEN) {
453 LIMIT_NETDEBUG(KERN_INFO "DCCP: packet too small"
454 " to insert feature %d option!\n", feat);
455 return -1;
456 }
457
458 DCCP_SKB_CB(skb)->dccpd_opt_len += len + 3;
459
460 to = skb_push(skb, len + 3);
461 *to++ = type;
462 *to++ = len + 3;
463 *to++ = feat;
464
465 if (len)
466 memcpy(to, val, len);
467 dccp_pr_debug("option %d feat %d len %d\n", type, feat, len);
468
469 return 0;
470 }
471
472 static int dccp_insert_options_feat(struct sock *sk, struct sk_buff *skb)
473 {
474 struct dccp_sock *dp = dccp_sk(sk);
475 struct dccp_minisock *dmsk = dccp_msk(sk);
476 struct dccp_opt_pend *opt, *next;
477 int change = 0;
478
479 /* confirm any options [NN opts] */
480 list_for_each_entry_safe(opt, next, &dmsk->dccpms_conf, dccpop_node) {
481 dccp_insert_feat_opt(skb, opt->dccpop_type,
482 opt->dccpop_feat, opt->dccpop_val,
483 opt->dccpop_len);
484 /* fear empty confirms */
485 if (opt->dccpop_val)
486 kfree(opt->dccpop_val);
487 kfree(opt);
488 }
489 INIT_LIST_HEAD(&dmsk->dccpms_conf);
490
491 /* see which features we need to send */
492 list_for_each_entry(opt, &dmsk->dccpms_pending, dccpop_node) {
493 /* see if we need to send any confirm */
494 if (opt->dccpop_sc) {
495 dccp_insert_feat_opt(skb, opt->dccpop_type + 1,
496 opt->dccpop_feat,
497 opt->dccpop_sc->dccpoc_val,
498 opt->dccpop_sc->dccpoc_len);
499
500 BUG_ON(!opt->dccpop_sc->dccpoc_val);
501 kfree(opt->dccpop_sc->dccpoc_val);
502 kfree(opt->dccpop_sc);
503 opt->dccpop_sc = NULL;
504 }
505
506 /* any option not confirmed, re-send it */
507 if (!opt->dccpop_conf) {
508 dccp_insert_feat_opt(skb, opt->dccpop_type,
509 opt->dccpop_feat, opt->dccpop_val,
510 opt->dccpop_len);
511 change++;
512 }
513 }
514
515 /* Retransmit timer.
516 * If this is the master listening sock, we don't set a timer on it. It
517 * should be fine because if the dude doesn't receive our RESPONSE
518 * [which will contain the CHANGE] he will send another REQUEST which
519 * will "retrnasmit" the change.
520 */
521 if (change && dp->dccps_role != DCCP_ROLE_LISTEN) {
522 dccp_pr_debug("reset feat negotiation timer %p\n", sk);
523
524 /* XXX don't reset the timer on re-transmissions. I.e. reset it
525 * only when sending new stuff i guess. Currently the timer
526 * never backs off because on re-transmission it just resets it!
527 */
528 inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
529 inet_csk(sk)->icsk_rto, DCCP_RTO_MAX);
530 }
531
532 return 0;
533 }
534
535 int dccp_insert_options(struct sock *sk, struct sk_buff *skb)
536 {
537 struct dccp_sock *dp = dccp_sk(sk);
538 struct dccp_minisock *dmsk = dccp_msk(sk);
539
540 DCCP_SKB_CB(skb)->dccpd_opt_len = 0;
541
542 if (dmsk->dccpms_send_ndp_count &&
543 dccp_insert_option_ndp(sk, skb))
544 return -1;
545
546 if (!dccp_packet_without_ack(skb)) {
547 if (dmsk->dccpms_send_ack_vector &&
548 dccp_ackvec_pending(dp->dccps_hc_rx_ackvec) &&
549 dccp_insert_option_ackvec(sk, skb))
550 return -1;
551
552 if (dp->dccps_timestamp_echo != 0 &&
553 dccp_insert_option_timestamp_echo(sk, skb))
554 return -1;
555 }
556
557 if (dp->dccps_hc_rx_insert_options) {
558 if (ccid_hc_rx_insert_options(dp->dccps_hc_rx_ccid, sk, skb))
559 return -1;
560 dp->dccps_hc_rx_insert_options = 0;
561 }
562 if (dp->dccps_hc_tx_insert_options) {
563 if (ccid_hc_tx_insert_options(dp->dccps_hc_tx_ccid, sk, skb))
564 return -1;
565 dp->dccps_hc_tx_insert_options = 0;
566 }
567
568 /* Feature negotiation */
569 /* Data packets can't do feat negotiation */
570 if (DCCP_SKB_CB(skb)->dccpd_type != DCCP_PKT_DATA &&
571 DCCP_SKB_CB(skb)->dccpd_type != DCCP_PKT_DATAACK &&
572 dccp_insert_options_feat(sk, skb))
573 return -1;
574
575 /* XXX: insert other options when appropriate */
576
577 if (DCCP_SKB_CB(skb)->dccpd_opt_len != 0) {
578 /* The length of all options has to be a multiple of 4 */
579 int padding = DCCP_SKB_CB(skb)->dccpd_opt_len % 4;
580
581 if (padding != 0) {
582 padding = 4 - padding;
583 memset(skb_push(skb, padding), 0, padding);
584 DCCP_SKB_CB(skb)->dccpd_opt_len += padding;
585 }
586 }
587
588 return 0;
589 }
Support for the Chinese Samsung S3C2440 based development boards