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_minisock_init(struct dccp_minisock *dmsk)
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;
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));
82 while (opt_ptr != opt_end) {
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;
94 goto out_invalid_option;
96 * Remove the type and len fields, leaving
103 if (opt_ptr > opt_end)
104 goto out_invalid_option;
110 case DCCPO_MANDATORY:
112 goto out_invalid_option;
113 if (pkt_type != DCCP_PKT_DATA)
116 case DCCPO_NDP_COUNT:
118 goto out_invalid_option;
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);
128 goto out_invalid_option;
129 rc = dccp_feat_change_recv(sk, opt, *value, value + 1,
132 * When there is a change error, change_recv is
133 * responsible for dealing with it. i.e. reply with an
135 * If the change was mandatory, then we need to die.
138 goto out_invalid_option;
140 case DCCPO_CONFIRM_L:
142 case DCCPO_CONFIRM_R:
144 goto out_invalid_option;
145 if (dccp_feat_confirm_recv(sk, opt, *value,
147 goto out_invalid_option;
149 case DCCPO_ACK_VECTOR_0:
150 case DCCPO_ACK_VECTOR_1:
151 if (pkt_type == DCCP_PKT_DATA)
154 if (dccp_msk(sk)->dccpms_send_ack_vector &&
155 dccp_ackvec_parse(sk, skb, opt, value, len))
156 goto out_invalid_option;
158 case DCCPO_TIMESTAMP:
160 goto out_invalid_option;
162 opt_recv->dccpor_timestamp = ntohl(*(__be32 *)value);
164 dp->dccps_timestamp_echo = opt_recv->dccpor_timestamp;
165 dccp_timestamp(sk, &dp->dccps_timestamp_time);
167 dccp_pr_debug("%sTIMESTAMP=%u, ackno=%llu\n",
168 debug_prefix, opt_recv->dccpor_timestamp,
170 DCCP_SKB_CB(skb)->dccpd_ack_seq);
172 case DCCPO_TIMESTAMP_ECHO:
173 if (len != 4 && len != 6 && len != 8)
174 goto out_invalid_option;
176 opt_recv->dccpor_timestamp_echo = ntohl(*(__be32 *)value);
178 dccp_pr_debug("%sTIMESTAMP_ECHO=%u, len=%d, ackno=%llu, ",
180 opt_recv->dccpor_timestamp_echo,
183 DCCP_SKB_CB(skb)->dccpd_ack_seq);
190 elapsed_time = ntohs(*(__be16 *)(value + 4));
192 elapsed_time = ntohl(*(__be32 *)(value + 4));
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;
198 case DCCPO_ELAPSED_TIME:
199 if (len != 2 && len != 4)
200 goto out_invalid_option;
202 if (pkt_type == DCCP_PKT_DATA)
206 elapsed_time = ntohs(*(__be16 *)value);
208 elapsed_time = ntohl(*(__be32 *)value);
210 if (elapsed_time > opt_recv->dccpor_elapsed_time)
211 opt_recv->dccpor_elapsed_time = elapsed_time;
213 dccp_pr_debug("%sELAPSED_TIME=%d\n", debug_prefix,
217 * From draft-ietf-dccp-spec-11.txt:
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
226 const u16 idx = value - options;
228 if (ccid_hc_rx_parse_options(dp->dccps_hc_rx_ccid, sk,
231 goto out_invalid_option;
235 const u16 idx = value - options;
237 if (ccid_hc_tx_parse_options(dp->dccps_hc_tx_ccid, sk,
240 goto out_invalid_option;
244 pr_info("DCCP(%p): option %d(len=%d) not "
245 "implemented, ignoring\n",
250 if (opt != DCCPO_MANDATORY)
254 /* mandatory was the last byte in option list -> reset connection */
256 goto 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);
267 EXPORT_SYMBOL_GPL(dccp_parse_options);
269 static void dccp_encode_value_var(const u32 value, unsigned char *to,
270 const unsigned int len)
273 *to++ = (value & 0xFF000000) >> 24;
275 *to++ = (value & 0xFF0000) >> 16;
277 *to++ = (value & 0xFF00) >> 8;
279 *to++ = (value & 0xFF);
282 static inline int dccp_ndp_len(const int ndp)
284 return likely(ndp <= 0xFF) ? 1 : ndp <= 0xFFFF ? 2 : 3;
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)
293 if (DCCP_SKB_CB(skb)->dccpd_opt_len + len + 2 > DCCP_MAX_OPT_LEN)
296 DCCP_SKB_CB(skb)->dccpd_opt_len += len + 2;
298 to = skb_push(skb, len + 2);
302 memcpy(to, value, len);
306 EXPORT_SYMBOL_GPL(dccp_insert_option);
308 static int dccp_insert_option_ndp(struct sock *sk, struct sk_buff *skb)
310 struct dccp_sock *dp = dccp_sk(sk);
311 int ndp = dp->dccps_ndp_count;
313 if (dccp_non_data_packet(skb))
314 ++dp->dccps_ndp_count;
316 dp->dccps_ndp_count = 0;
320 const int ndp_len = dccp_ndp_len(ndp);
321 const int len = ndp_len + 2;
323 if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
326 DCCP_SKB_CB(skb)->dccpd_opt_len += len;
328 ptr = skb_push(skb, len);
329 *ptr++ = DCCPO_NDP_COUNT;
331 dccp_encode_value_var(ndp, ptr, ndp_len);
337 static inline int dccp_elapsed_time_len(const u32 elapsed_time)
339 return elapsed_time == 0 ? 0 : elapsed_time <= 0xFFFF ? 2 : 4;
342 int dccp_insert_option_elapsed_time(struct sock *sk, struct sk_buff *skb,
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)
355 DCCP_SKB_CB(skb)->dccpd_opt_len += len;
357 to = skb_push(skb, len);
358 *to++ = DCCPO_ELAPSED_TIME;
361 if (elapsed_time_len == 2) {
362 const __be16 var16 = htons((u16)elapsed_time);
363 memcpy(to, &var16, 2);
365 const __be32 var32 = htonl(elapsed_time);
366 memcpy(to, &var32, 4);
372 EXPORT_SYMBOL_GPL(dccp_insert_option_elapsed_time);
374 void dccp_timestamp(const struct sock *sk, struct timeval *tv)
376 const struct dccp_sock *dp = dccp_sk(sk);
379 tv->tv_sec -= dp->dccps_epoch.tv_sec;
380 tv->tv_usec -= dp->dccps_epoch.tv_usec;
382 while (tv->tv_usec < 0) {
384 tv->tv_usec += USEC_PER_SEC;
388 EXPORT_SYMBOL_GPL(dccp_timestamp);
390 int dccp_insert_option_timestamp(struct sock *sk, struct sk_buff *skb)
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 */
400 return dccp_insert_option(sk, skb, DCCPO_TIMESTAMP, &now, sizeof(now));
403 EXPORT_SYMBOL_GPL(dccp_insert_option_timestamp);
405 static int dccp_insert_option_timestamp_echo(struct sock *sk,
408 struct dccp_sock *dp = dccp_sk(sk);
412 int len, elapsed_time_len;
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;
420 if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
423 DCCP_SKB_CB(skb)->dccpd_opt_len += len;
425 to = skb_push(skb, len);
426 *to++ = DCCPO_TIMESTAMP_ECHO;
429 tstamp_echo = htonl(dp->dccps_timestamp_echo);
430 memcpy(to, &tstamp_echo, 4);
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);
441 dp->dccps_timestamp_echo = 0;
442 dp->dccps_timestamp_time.tv_sec = 0;
443 dp->dccps_timestamp_time.tv_usec = 0;
447 static int dccp_insert_feat_opt(struct sk_buff *skb, u8 type, u8 feat,
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);
458 DCCP_SKB_CB(skb)->dccpd_opt_len += len + 3;
460 to = skb_push(skb, len + 3);
466 memcpy(to, val, len);
467 dccp_pr_debug("option %d feat %d len %d\n", type, feat, len);
472 static int dccp_insert_options_feat(struct sock *sk, struct sk_buff *skb)
474 struct dccp_sock *dp = dccp_sk(sk);
475 struct dccp_minisock *dmsk = dccp_msk(sk);
476 struct dccp_opt_pend *opt, *next;
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,
484 /* fear empty confirms */
486 kfree(opt->dccpop_val);
489 INIT_LIST_HEAD(&dmsk->dccpms_conf);
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,
497 opt->dccpop_sc->dccpoc_val,
498 opt->dccpop_sc->dccpoc_len);
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;
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,
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.
521 if (change && dp->dccps_role != DCCP_ROLE_LISTEN) {
522 dccp_pr_debug("reset feat negotiation timer %p\n", sk);
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!
528 inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
529 inet_csk(sk)->icsk_rto, DCCP_RTO_MAX);
535 int dccp_insert_options(struct sock *sk, struct sk_buff *skb)
537 struct dccp_sock *dp = dccp_sk(sk);
538 struct dccp_minisock *dmsk = dccp_msk(sk);
540 DCCP_SKB_CB(skb)->dccpd_opt_len = 0;
542 if (dmsk->dccpms_send_ndp_count &&
543 dccp_insert_option_ndp(sk, skb))
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))
552 if (dp->dccps_timestamp_echo != 0 &&
553 dccp_insert_option_timestamp_echo(sk, skb))
557 if (dp->dccps_hc_rx_insert_options) {
558 if (ccid_hc_rx_insert_options(dp->dccps_hc_rx_ccid, sk, skb))
560 dp->dccps_hc_rx_insert_options = 0;
562 if (dp->dccps_hc_tx_insert_options) {
563 if (ccid_hc_tx_insert_options(dp->dccps_hc_tx_ccid, sk, skb))
565 dp->dccps_hc_tx_insert_options = 0;
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))
575 /* XXX: insert other options when appropriate */
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;
582 padding = 4 - padding;
583 memset(skb_push(skb, padding), 0, padding);
584 DCCP_SKB_CB(skb)->dccpd_opt_len += padding;