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;
114 case DCCPO_NDP_COUNT:
116 goto out_invalid_option;
118 opt_recv->dccpor_ndp = dccp_decode_value_var(value, len);
119 dccp_pr_debug("%sNDP count=%d\n", debug_prefix,
120 opt_recv->dccpor_ndp);
126 goto out_invalid_option;
127 rc = dccp_feat_change_recv(sk, opt, *value, value + 1,
130 * When there is a change error, change_recv is
131 * responsible for dealing with it. i.e. reply with an
133 * If the change was mandatory, then we need to die.
136 goto out_invalid_option;
138 case DCCPO_CONFIRM_L:
140 case DCCPO_CONFIRM_R:
142 goto out_invalid_option;
143 if (dccp_feat_confirm_recv(sk, opt, *value,
145 goto out_invalid_option;
147 case DCCPO_ACK_VECTOR_0:
148 case DCCPO_ACK_VECTOR_1:
149 if (pkt_type == DCCP_PKT_DATA)
152 if (dp->dccps_options.dccpo_send_ack_vector &&
153 dccp_ackvec_parse(sk, skb, opt, value, len))
154 goto out_invalid_option;
156 case DCCPO_TIMESTAMP:
158 goto out_invalid_option;
160 opt_recv->dccpor_timestamp = ntohl(*(__be32 *)value);
162 dp->dccps_timestamp_echo = opt_recv->dccpor_timestamp;
163 dccp_timestamp(sk, &dp->dccps_timestamp_time);
165 dccp_pr_debug("%sTIMESTAMP=%u, ackno=%llu\n",
166 debug_prefix, opt_recv->dccpor_timestamp,
168 DCCP_SKB_CB(skb)->dccpd_ack_seq);
170 case DCCPO_TIMESTAMP_ECHO:
171 if (len != 4 && len != 6 && len != 8)
172 goto out_invalid_option;
174 opt_recv->dccpor_timestamp_echo = ntohl(*(__be32 *)value);
176 dccp_pr_debug("%sTIMESTAMP_ECHO=%u, len=%d, ackno=%llu, ",
178 opt_recv->dccpor_timestamp_echo,
181 DCCP_SKB_CB(skb)->dccpd_ack_seq);
188 elapsed_time = ntohs(*(__be16 *)(value + 4));
190 elapsed_time = ntohl(*(__be32 *)(value + 4));
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;
196 case DCCPO_ELAPSED_TIME:
197 if (len != 2 && len != 4)
198 goto out_invalid_option;
200 if (pkt_type == DCCP_PKT_DATA)
204 elapsed_time = ntohs(*(__be16 *)value);
206 elapsed_time = ntohl(*(__be32 *)value);
208 if (elapsed_time > opt_recv->dccpor_elapsed_time)
209 opt_recv->dccpor_elapsed_time = elapsed_time;
211 dccp_pr_debug("%sELAPSED_TIME=%d\n", debug_prefix,
215 * From draft-ietf-dccp-spec-11.txt:
217 * Option numbers 128 through 191 are for
218 * options sent from the HC-Sender to the
219 * HC-Receiver; option numbers 192 through 255
220 * are for options sent from the HC-Receiver to
224 const u16 idx = value - options;
226 if (ccid_hc_rx_parse_options(dp->dccps_hc_rx_ccid, sk,
229 goto out_invalid_option;
233 const u16 idx = value - options;
235 if (ccid_hc_tx_parse_options(dp->dccps_hc_tx_ccid, sk,
238 goto out_invalid_option;
242 pr_info("DCCP(%p): option %d(len=%d) not "
243 "implemented, ignoring\n",
248 if (opt != DCCPO_MANDATORY)
255 DCCP_INC_STATS_BH(DCCP_MIB_INVALIDOPT);
256 DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_OPTION_ERROR;
257 pr_info("DCCP(%p): invalid option %d, len=%d\n", sk, opt, len);
261 EXPORT_SYMBOL_GPL(dccp_parse_options);
263 static void dccp_encode_value_var(const u32 value, unsigned char *to,
264 const unsigned int len)
267 *to++ = (value & 0xFF000000) >> 24;
269 *to++ = (value & 0xFF0000) >> 16;
271 *to++ = (value & 0xFF00) >> 8;
273 *to++ = (value & 0xFF);
276 static inline int dccp_ndp_len(const int ndp)
278 return likely(ndp <= 0xFF) ? 1 : ndp <= 0xFFFF ? 2 : 3;
281 void dccp_insert_option(struct sock *sk, struct sk_buff *skb,
282 const unsigned char option,
283 const void *value, const unsigned char len)
287 if (DCCP_SKB_CB(skb)->dccpd_opt_len + len + 2 > DCCP_MAX_OPT_LEN) {
288 LIMIT_NETDEBUG(KERN_INFO "DCCP: packet too small to insert "
289 "%d option!\n", option);
293 DCCP_SKB_CB(skb)->dccpd_opt_len += len + 2;
295 to = skb_push(skb, len + 2);
299 memcpy(to, value, len);
302 EXPORT_SYMBOL_GPL(dccp_insert_option);
304 static void dccp_insert_option_ndp(struct sock *sk, struct sk_buff *skb)
306 struct dccp_sock *dp = dccp_sk(sk);
307 int ndp = dp->dccps_ndp_count;
309 if (dccp_non_data_packet(skb))
310 ++dp->dccps_ndp_count;
312 dp->dccps_ndp_count = 0;
316 const int ndp_len = dccp_ndp_len(ndp);
317 const int len = ndp_len + 2;
319 if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
322 DCCP_SKB_CB(skb)->dccpd_opt_len += len;
324 ptr = skb_push(skb, len);
325 *ptr++ = DCCPO_NDP_COUNT;
327 dccp_encode_value_var(ndp, ptr, ndp_len);
331 static inline int dccp_elapsed_time_len(const u32 elapsed_time)
333 return elapsed_time == 0 ? 0 : elapsed_time <= 0xFFFF ? 2 : 4;
336 void dccp_insert_option_elapsed_time(struct sock *sk,
340 #ifdef CONFIG_IP_DCCP_DEBUG
341 struct dccp_sock *dp = dccp_sk(sk);
342 const char *debug_prefix = dp->dccps_role == DCCP_ROLE_CLIENT ?
343 "CLIENT TX opt: " : "server TX opt: ";
345 const int elapsed_time_len = dccp_elapsed_time_len(elapsed_time);
346 const int len = 2 + elapsed_time_len;
349 if (elapsed_time_len == 0)
352 if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN) {
353 LIMIT_NETDEBUG(KERN_INFO "DCCP: packet too small to "
354 "insert elapsed time!\n");
358 DCCP_SKB_CB(skb)->dccpd_opt_len += len;
360 to = skb_push(skb, len);
361 *to++ = DCCPO_ELAPSED_TIME;
364 if (elapsed_time_len == 2) {
365 const __be16 var16 = htons((u16)elapsed_time);
366 memcpy(to, &var16, 2);
368 const __be32 var32 = htonl(elapsed_time);
369 memcpy(to, &var32, 4);
372 dccp_pr_debug("%sELAPSED_TIME=%u, len=%d, seqno=%llu\n",
373 debug_prefix, elapsed_time,
375 (unsigned long long) DCCP_SKB_CB(skb)->dccpd_seq);
378 EXPORT_SYMBOL_GPL(dccp_insert_option_elapsed_time);
380 void dccp_timestamp(const struct sock *sk, struct timeval *tv)
382 const struct dccp_sock *dp = dccp_sk(sk);
385 tv->tv_sec -= dp->dccps_epoch.tv_sec;
386 tv->tv_usec -= dp->dccps_epoch.tv_usec;
388 while (tv->tv_usec < 0) {
390 tv->tv_usec += USEC_PER_SEC;
394 EXPORT_SYMBOL_GPL(dccp_timestamp);
396 void dccp_insert_option_timestamp(struct sock *sk, struct sk_buff *skb)
401 dccp_timestamp(sk, &tv);
402 now = htonl(timeval_usecs(&tv) / 10);
403 /* yes this will overflow but that is the point as we want a
404 * 10 usec 32 bit timer which mean it wraps every 11.9 hours */
406 dccp_insert_option(sk, skb, DCCPO_TIMESTAMP, &now, sizeof(now));
409 EXPORT_SYMBOL_GPL(dccp_insert_option_timestamp);
411 static void dccp_insert_option_timestamp_echo(struct sock *sk,
414 struct dccp_sock *dp = dccp_sk(sk);
415 #ifdef CONFIG_IP_DCCP_DEBUG
416 const char *debug_prefix = dp->dccps_role == DCCP_ROLE_CLIENT ?
417 "CLIENT TX opt: " : "server TX opt: ";
422 int len, elapsed_time_len;
425 dccp_timestamp(sk, &now);
426 elapsed_time = timeval_delta(&now, &dp->dccps_timestamp_time) / 10;
427 elapsed_time_len = dccp_elapsed_time_len(elapsed_time);
428 len = 6 + elapsed_time_len;
430 if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN) {
431 LIMIT_NETDEBUG(KERN_INFO "DCCP: packet too small to insert "
432 "timestamp echo!\n");
436 DCCP_SKB_CB(skb)->dccpd_opt_len += len;
438 to = skb_push(skb, len);
439 *to++ = DCCPO_TIMESTAMP_ECHO;
442 tstamp_echo = htonl(dp->dccps_timestamp_echo);
443 memcpy(to, &tstamp_echo, 4);
446 if (elapsed_time_len == 2) {
447 const __be16 var16 = htons((u16)elapsed_time);
448 memcpy(to, &var16, 2);
449 } else if (elapsed_time_len == 4) {
450 const __be32 var32 = htonl(elapsed_time);
451 memcpy(to, &var32, 4);
454 dccp_pr_debug("%sTIMESTAMP_ECHO=%u, len=%d, seqno=%llu\n",
455 debug_prefix, dp->dccps_timestamp_echo,
457 (unsigned long long) DCCP_SKB_CB(skb)->dccpd_seq);
459 dp->dccps_timestamp_echo = 0;
460 dp->dccps_timestamp_time.tv_sec = 0;
461 dp->dccps_timestamp_time.tv_usec = 0;
464 static int dccp_insert_feat_opt(struct sk_buff *skb, u8 type, u8 feat,
469 if (DCCP_SKB_CB(skb)->dccpd_opt_len + len + 3 > DCCP_MAX_OPT_LEN) {
470 LIMIT_NETDEBUG(KERN_INFO "DCCP: packet too small"
471 " to insert feature %d option!\n", feat);
475 DCCP_SKB_CB(skb)->dccpd_opt_len += len + 3;
477 to = skb_push(skb, len + 3);
483 memcpy(to, val, len);
484 dccp_pr_debug("option %d feat %d len %d\n", type, feat, len);
489 static void dccp_insert_feat(struct sock *sk, struct sk_buff *skb)
491 struct dccp_sock *dp = dccp_sk(sk);
492 struct dccp_opt_pend *opt, *next;
495 /* confirm any options [NN opts] */
496 list_for_each_entry_safe(opt, next, &dp->dccps_options.dccpo_conf,
498 dccp_insert_feat_opt(skb, opt->dccpop_type,
499 opt->dccpop_feat, opt->dccpop_val,
501 /* fear empty confirms */
503 kfree(opt->dccpop_val);
506 INIT_LIST_HEAD(&dp->dccps_options.dccpo_conf);
508 /* see which features we need to send */
509 list_for_each_entry(opt, &dp->dccps_options.dccpo_pending,
511 /* see if we need to send any confirm */
512 if (opt->dccpop_sc) {
513 dccp_insert_feat_opt(skb, opt->dccpop_type + 1,
515 opt->dccpop_sc->dccpoc_val,
516 opt->dccpop_sc->dccpoc_len);
518 BUG_ON(!opt->dccpop_sc->dccpoc_val);
519 kfree(opt->dccpop_sc->dccpoc_val);
520 kfree(opt->dccpop_sc);
521 opt->dccpop_sc = NULL;
524 /* any option not confirmed, re-send it */
525 if (!opt->dccpop_conf) {
526 dccp_insert_feat_opt(skb, opt->dccpop_type,
527 opt->dccpop_feat, opt->dccpop_val,
534 * If this is the master listening sock, we don't set a timer on it. It
535 * should be fine because if the dude doesn't receive our RESPONSE
536 * [which will contain the CHANGE] he will send another REQUEST which
537 * will "retrnasmit" the change.
539 if (change && dp->dccps_role != DCCP_ROLE_LISTEN) {
540 dccp_pr_debug("reset feat negotiation timer %p\n", sk);
542 /* XXX don't reset the timer on re-transmissions. I.e. reset it
543 * only when sending new stuff i guess. Currently the timer
544 * never backs off because on re-transmission it just resets it!
546 inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
547 inet_csk(sk)->icsk_rto, DCCP_RTO_MAX);
551 void dccp_insert_options(struct sock *sk, struct sk_buff *skb)
553 struct dccp_sock *dp = dccp_sk(sk);
555 DCCP_SKB_CB(skb)->dccpd_opt_len = 0;
557 if (dp->dccps_options.dccpo_send_ndp_count)
558 dccp_insert_option_ndp(sk, skb);
560 if (!dccp_packet_without_ack(skb)) {
561 if (dp->dccps_options.dccpo_send_ack_vector &&
562 dccp_ackvec_pending(dp->dccps_hc_rx_ackvec))
563 dccp_insert_option_ackvec(sk, skb);
564 if (dp->dccps_timestamp_echo != 0)
565 dccp_insert_option_timestamp_echo(sk, skb);
568 if (dp->dccps_hc_rx_insert_options) {
569 ccid_hc_rx_insert_options(dp->dccps_hc_rx_ccid, sk, skb);
570 dp->dccps_hc_rx_insert_options = 0;
572 if (dp->dccps_hc_tx_insert_options) {
573 ccid_hc_tx_insert_options(dp->dccps_hc_tx_ccid, sk, skb);
574 dp->dccps_hc_tx_insert_options = 0;
577 /* Feature negotiation */
578 switch(DCCP_SKB_CB(skb)->dccpd_type) {
579 /* Data packets can't do feat negotiation */
581 case DCCP_PKT_DATAACK:
584 dccp_insert_feat(sk, skb);
588 /* XXX: insert other options when appropriate */
590 if (DCCP_SKB_CB(skb)->dccpd_opt_len != 0) {
591 /* The length of all options has to be a multiple of 4 */
592 int padding = DCCP_SKB_CB(skb)->dccpd_opt_len % 4;
595 padding = 4 - padding;
596 memset(skb_push(skb, padding), 0, padding);
597 DCCP_SKB_CB(skb)->dccpd_opt_len += padding;