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>
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.
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>
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;
33 void dccp_options_init(struct dccp_options *dccpo)
35 dccpo->dccpo_sequence_window = dccp_feat_default_sequence_window;
36 dccpo->dccpo_rx_ccid = dccp_feat_default_rx_ccid;
37 dccpo->dccpo_tx_ccid = dccp_feat_default_tx_ccid;
38 dccpo->dccpo_ack_ratio = dccp_feat_default_ack_ratio;
39 dccpo->dccpo_send_ack_vector = dccp_feat_default_send_ack_vector;
40 dccpo->dccpo_send_ndp_count = dccp_feat_default_send_ndp_count;
43 static u32 dccp_decode_value_var(const unsigned char *bf, const u8 len)
59 int dccp_parse_options(struct sock *sk, struct sk_buff *skb)
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: ";
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 +
72 struct dccp_options_received *opt_recv = &dp->dccps_options_received;
73 unsigned char opt, len;
79 memset(opt_recv, 0, sizeof(*opt_recv));
81 while (opt_ptr != opt_end) {
86 /* Check if this isn't a single byte option */
87 if (opt > DCCPO_MAX_RESERVED) {
88 if (opt_ptr == opt_end)
89 goto out_invalid_option;
93 goto out_invalid_option;
95 * Remove the type and len fields, leaving
102 if (opt_ptr > opt_end)
103 goto out_invalid_option;
109 case DCCPO_MANDATORY:
111 goto out_invalid_option;
112 if (pkt_type != DCCP_PKT_DATA)
115 case DCCPO_NDP_COUNT:
117 goto out_invalid_option;
119 opt_recv->dccpor_ndp = dccp_decode_value_var(value, len);
120 dccp_pr_debug("%sNDP count=%d\n", debug_prefix,
121 opt_recv->dccpor_ndp);
127 goto out_invalid_option;
128 rc = dccp_feat_change_recv(sk, opt, *value, value + 1,
131 * When there is a change error, change_recv is
132 * responsible for dealing with it. i.e. reply with an
134 * If the change was mandatory, then we need to die.
137 goto out_invalid_option;
139 case DCCPO_CONFIRM_L:
141 case DCCPO_CONFIRM_R:
143 goto out_invalid_option;
144 if (dccp_feat_confirm_recv(sk, opt, *value,
146 goto out_invalid_option;
148 case DCCPO_ACK_VECTOR_0:
149 case DCCPO_ACK_VECTOR_1:
150 if (pkt_type == DCCP_PKT_DATA)
153 if (dp->dccps_options.dccpo_send_ack_vector &&
154 dccp_ackvec_parse(sk, skb, opt, value, len))
155 goto out_invalid_option;
157 case DCCPO_TIMESTAMP:
159 goto out_invalid_option;
161 opt_recv->dccpor_timestamp = ntohl(*(__be32 *)value);
163 dp->dccps_timestamp_echo = opt_recv->dccpor_timestamp;
164 dccp_timestamp(sk, &dp->dccps_timestamp_time);
166 dccp_pr_debug("%sTIMESTAMP=%u, ackno=%llu\n",
167 debug_prefix, opt_recv->dccpor_timestamp,
169 DCCP_SKB_CB(skb)->dccpd_ack_seq);
171 case DCCPO_TIMESTAMP_ECHO:
172 if (len != 4 && len != 6 && len != 8)
173 goto out_invalid_option;
175 opt_recv->dccpor_timestamp_echo = ntohl(*(__be32 *)value);
177 dccp_pr_debug("%sTIMESTAMP_ECHO=%u, len=%d, ackno=%llu, ",
179 opt_recv->dccpor_timestamp_echo,
182 DCCP_SKB_CB(skb)->dccpd_ack_seq);
189 elapsed_time = ntohs(*(__be16 *)(value + 4));
191 elapsed_time = ntohl(*(__be32 *)(value + 4));
193 /* Give precedence to the biggest ELAPSED_TIME */
194 if (elapsed_time > opt_recv->dccpor_elapsed_time)
195 opt_recv->dccpor_elapsed_time = elapsed_time;
197 case DCCPO_ELAPSED_TIME:
198 if (len != 2 && len != 4)
199 goto out_invalid_option;
201 if (pkt_type == DCCP_PKT_DATA)
205 elapsed_time = ntohs(*(__be16 *)value);
207 elapsed_time = ntohl(*(__be32 *)value);
209 if (elapsed_time > opt_recv->dccpor_elapsed_time)
210 opt_recv->dccpor_elapsed_time = elapsed_time;
212 dccp_pr_debug("%sELAPSED_TIME=%d\n", debug_prefix,
216 * From draft-ietf-dccp-spec-11.txt:
218 * Option numbers 128 through 191 are for
219 * options sent from the HC-Sender to the
220 * HC-Receiver; option numbers 192 through 255
221 * are for options sent from the HC-Receiver to
225 const u16 idx = value - options;
227 if (ccid_hc_rx_parse_options(dp->dccps_hc_rx_ccid, sk,
230 goto out_invalid_option;
234 const u16 idx = value - options;
236 if (ccid_hc_tx_parse_options(dp->dccps_hc_tx_ccid, sk,
239 goto out_invalid_option;
243 pr_info("DCCP(%p): option %d(len=%d) not "
244 "implemented, ignoring\n",
249 if (opt != DCCPO_MANDATORY)
253 /* mandatory was the last byte in option list -> reset connection */
255 goto 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 pr_info("DCCP(%p): invalid option %d, len=%d\n", sk, opt, len);
266 EXPORT_SYMBOL_GPL(dccp_parse_options);
268 static void dccp_encode_value_var(const u32 value, unsigned char *to,
269 const unsigned int len)
272 *to++ = (value & 0xFF000000) >> 24;
274 *to++ = (value & 0xFF0000) >> 16;
276 *to++ = (value & 0xFF00) >> 8;
278 *to++ = (value & 0xFF);
281 static inline int dccp_ndp_len(const int ndp)
283 return likely(ndp <= 0xFF) ? 1 : ndp <= 0xFFFF ? 2 : 3;
286 void dccp_insert_option(struct sock *sk, struct sk_buff *skb,
287 const unsigned char option,
288 const void *value, const unsigned char len)
292 if (DCCP_SKB_CB(skb)->dccpd_opt_len + len + 2 > DCCP_MAX_OPT_LEN) {
293 LIMIT_NETDEBUG(KERN_INFO "DCCP: packet too small to insert "
294 "%d option!\n", option);
298 DCCP_SKB_CB(skb)->dccpd_opt_len += len + 2;
300 to = skb_push(skb, len + 2);
304 memcpy(to, value, len);
307 EXPORT_SYMBOL_GPL(dccp_insert_option);
309 static void dccp_insert_option_ndp(struct sock *sk, struct sk_buff *skb)
311 struct dccp_sock *dp = dccp_sk(sk);
312 int ndp = dp->dccps_ndp_count;
314 if (dccp_non_data_packet(skb))
315 ++dp->dccps_ndp_count;
317 dp->dccps_ndp_count = 0;
321 const int ndp_len = dccp_ndp_len(ndp);
322 const int len = ndp_len + 2;
324 if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
327 DCCP_SKB_CB(skb)->dccpd_opt_len += len;
329 ptr = skb_push(skb, len);
330 *ptr++ = DCCPO_NDP_COUNT;
332 dccp_encode_value_var(ndp, ptr, ndp_len);
336 static inline int dccp_elapsed_time_len(const u32 elapsed_time)
338 return elapsed_time == 0 ? 0 : elapsed_time <= 0xFFFF ? 2 : 4;
341 void dccp_insert_option_elapsed_time(struct sock *sk,
345 #ifdef CONFIG_IP_DCCP_DEBUG
346 struct dccp_sock *dp = dccp_sk(sk);
347 const char *debug_prefix = dp->dccps_role == DCCP_ROLE_CLIENT ?
348 "CLIENT TX opt: " : "server TX opt: ";
350 const int elapsed_time_len = dccp_elapsed_time_len(elapsed_time);
351 const int len = 2 + elapsed_time_len;
354 if (elapsed_time_len == 0)
357 if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN) {
358 LIMIT_NETDEBUG(KERN_INFO "DCCP: packet too small to "
359 "insert elapsed time!\n");
363 DCCP_SKB_CB(skb)->dccpd_opt_len += len;
365 to = skb_push(skb, len);
366 *to++ = DCCPO_ELAPSED_TIME;
369 if (elapsed_time_len == 2) {
370 const __be16 var16 = htons((u16)elapsed_time);
371 memcpy(to, &var16, 2);
373 const __be32 var32 = htonl(elapsed_time);
374 memcpy(to, &var32, 4);
377 dccp_pr_debug("%sELAPSED_TIME=%u, len=%d, seqno=%llu\n",
378 debug_prefix, elapsed_time,
380 (unsigned long long) DCCP_SKB_CB(skb)->dccpd_seq);
383 EXPORT_SYMBOL_GPL(dccp_insert_option_elapsed_time);
385 void dccp_timestamp(const struct sock *sk, struct timeval *tv)
387 const struct dccp_sock *dp = dccp_sk(sk);
390 tv->tv_sec -= dp->dccps_epoch.tv_sec;
391 tv->tv_usec -= dp->dccps_epoch.tv_usec;
393 while (tv->tv_usec < 0) {
395 tv->tv_usec += USEC_PER_SEC;
399 EXPORT_SYMBOL_GPL(dccp_timestamp);
401 void dccp_insert_option_timestamp(struct sock *sk, struct sk_buff *skb)
406 dccp_timestamp(sk, &tv);
407 now = htonl(timeval_usecs(&tv) / 10);
408 /* yes this will overflow but that is the point as we want a
409 * 10 usec 32 bit timer which mean it wraps every 11.9 hours */
411 dccp_insert_option(sk, skb, DCCPO_TIMESTAMP, &now, sizeof(now));
414 EXPORT_SYMBOL_GPL(dccp_insert_option_timestamp);
416 static void dccp_insert_option_timestamp_echo(struct sock *sk,
419 struct dccp_sock *dp = dccp_sk(sk);
420 #ifdef CONFIG_IP_DCCP_DEBUG
421 const char *debug_prefix = dp->dccps_role == DCCP_ROLE_CLIENT ?
422 "CLIENT TX opt: " : "server TX opt: ";
427 int len, elapsed_time_len;
430 dccp_timestamp(sk, &now);
431 elapsed_time = timeval_delta(&now, &dp->dccps_timestamp_time) / 10;
432 elapsed_time_len = dccp_elapsed_time_len(elapsed_time);
433 len = 6 + elapsed_time_len;
435 if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN) {
436 LIMIT_NETDEBUG(KERN_INFO "DCCP: packet too small to insert "
437 "timestamp echo!\n");
441 DCCP_SKB_CB(skb)->dccpd_opt_len += len;
443 to = skb_push(skb, len);
444 *to++ = DCCPO_TIMESTAMP_ECHO;
447 tstamp_echo = htonl(dp->dccps_timestamp_echo);
448 memcpy(to, &tstamp_echo, 4);
451 if (elapsed_time_len == 2) {
452 const __be16 var16 = htons((u16)elapsed_time);
453 memcpy(to, &var16, 2);
454 } else if (elapsed_time_len == 4) {
455 const __be32 var32 = htonl(elapsed_time);
456 memcpy(to, &var32, 4);
459 dccp_pr_debug("%sTIMESTAMP_ECHO=%u, len=%d, seqno=%llu\n",
460 debug_prefix, dp->dccps_timestamp_echo,
462 (unsigned long long) DCCP_SKB_CB(skb)->dccpd_seq);
464 dp->dccps_timestamp_echo = 0;
465 dp->dccps_timestamp_time.tv_sec = 0;
466 dp->dccps_timestamp_time.tv_usec = 0;
469 static int dccp_insert_feat_opt(struct sk_buff *skb, u8 type, u8 feat,
474 if (DCCP_SKB_CB(skb)->dccpd_opt_len + len + 3 > DCCP_MAX_OPT_LEN) {
475 LIMIT_NETDEBUG(KERN_INFO "DCCP: packet too small"
476 " to insert feature %d option!\n", feat);
480 DCCP_SKB_CB(skb)->dccpd_opt_len += len + 3;
482 to = skb_push(skb, len + 3);
488 memcpy(to, val, len);
489 dccp_pr_debug("option %d feat %d len %d\n", type, feat, len);
494 static void dccp_insert_feat(struct sock *sk, struct sk_buff *skb)
496 struct dccp_sock *dp = dccp_sk(sk);
497 struct dccp_opt_pend *opt, *next;
500 /* confirm any options [NN opts] */
501 list_for_each_entry_safe(opt, next, &dp->dccps_options.dccpo_conf,
503 dccp_insert_feat_opt(skb, opt->dccpop_type,
504 opt->dccpop_feat, opt->dccpop_val,
506 /* fear empty confirms */
508 kfree(opt->dccpop_val);
511 INIT_LIST_HEAD(&dp->dccps_options.dccpo_conf);
513 /* see which features we need to send */
514 list_for_each_entry(opt, &dp->dccps_options.dccpo_pending,
516 /* see if we need to send any confirm */
517 if (opt->dccpop_sc) {
518 dccp_insert_feat_opt(skb, opt->dccpop_type + 1,
520 opt->dccpop_sc->dccpoc_val,
521 opt->dccpop_sc->dccpoc_len);
523 BUG_ON(!opt->dccpop_sc->dccpoc_val);
524 kfree(opt->dccpop_sc->dccpoc_val);
525 kfree(opt->dccpop_sc);
526 opt->dccpop_sc = NULL;
529 /* any option not confirmed, re-send it */
530 if (!opt->dccpop_conf) {
531 dccp_insert_feat_opt(skb, opt->dccpop_type,
532 opt->dccpop_feat, opt->dccpop_val,
539 * If this is the master listening sock, we don't set a timer on it. It
540 * should be fine because if the dude doesn't receive our RESPONSE
541 * [which will contain the CHANGE] he will send another REQUEST which
542 * will "retrnasmit" the change.
544 if (change && dp->dccps_role != DCCP_ROLE_LISTEN) {
545 dccp_pr_debug("reset feat negotiation timer %p\n", sk);
547 /* XXX don't reset the timer on re-transmissions. I.e. reset it
548 * only when sending new stuff i guess. Currently the timer
549 * never backs off because on re-transmission it just resets it!
551 inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
552 inet_csk(sk)->icsk_rto, DCCP_RTO_MAX);
556 void dccp_insert_options(struct sock *sk, struct sk_buff *skb)
558 struct dccp_sock *dp = dccp_sk(sk);
560 DCCP_SKB_CB(skb)->dccpd_opt_len = 0;
562 if (dp->dccps_options.dccpo_send_ndp_count)
563 dccp_insert_option_ndp(sk, skb);
565 if (!dccp_packet_without_ack(skb)) {
566 if (dp->dccps_options.dccpo_send_ack_vector &&
567 dccp_ackvec_pending(dp->dccps_hc_rx_ackvec))
568 dccp_insert_option_ackvec(sk, skb);
569 if (dp->dccps_timestamp_echo != 0)
570 dccp_insert_option_timestamp_echo(sk, skb);
573 if (dp->dccps_hc_rx_insert_options) {
574 ccid_hc_rx_insert_options(dp->dccps_hc_rx_ccid, sk, skb);
575 dp->dccps_hc_rx_insert_options = 0;
577 if (dp->dccps_hc_tx_insert_options) {
578 ccid_hc_tx_insert_options(dp->dccps_hc_tx_ccid, sk, skb);
579 dp->dccps_hc_tx_insert_options = 0;
582 /* Feature negotiation */
583 switch(DCCP_SKB_CB(skb)->dccpd_type) {
584 /* Data packets can't do feat negotiation */
586 case DCCP_PKT_DATAACK:
589 dccp_insert_feat(sk, skb);
593 /* XXX: insert other options when appropriate */
595 if (DCCP_SKB_CB(skb)->dccpd_opt_len != 0) {
596 /* The length of all options has to be a multiple of 4 */
597 int padding = DCCP_SKB_CB(skb)->dccpd_opt_len % 4;
600 padding = 4 - padding;
601 memset(skb_push(skb, padding), 0, padding);
602 DCCP_SKB_CB(skb)->dccpd_opt_len += padding;