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>
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/dccp.h>
15 #include <linux/module.h>
16 #include <linux/types.h>
17 #include <linux/kernel.h>
18 #include <linux/skbuff.h>
25 int sysctl_dccp_feat_sequence_window = DCCPF_INITIAL_SEQUENCE_WINDOW;
26 int sysctl_dccp_feat_rx_ccid = DCCPF_INITIAL_CCID;
27 int sysctl_dccp_feat_tx_ccid = DCCPF_INITIAL_CCID;
28 int sysctl_dccp_feat_ack_ratio = DCCPF_INITIAL_ACK_RATIO;
29 int sysctl_dccp_feat_send_ack_vector = DCCPF_INITIAL_SEND_ACK_VECTOR;
30 int sysctl_dccp_feat_send_ndp_count = DCCPF_INITIAL_SEND_NDP_COUNT;
32 void dccp_minisock_init(struct dccp_minisock *dmsk)
34 dmsk->dccpms_sequence_window = sysctl_dccp_feat_sequence_window;
35 dmsk->dccpms_rx_ccid = sysctl_dccp_feat_rx_ccid;
36 dmsk->dccpms_tx_ccid = sysctl_dccp_feat_tx_ccid;
37 dmsk->dccpms_ack_ratio = sysctl_dccp_feat_ack_ratio;
38 dmsk->dccpms_send_ack_vector = sysctl_dccp_feat_send_ack_vector;
39 dmsk->dccpms_send_ndp_count = sysctl_dccp_feat_send_ndp_count;
42 static u32 dccp_decode_value_var(const unsigned char *bf, const u8 len)
58 int dccp_parse_options(struct sock *sk, struct sk_buff *skb)
60 struct dccp_sock *dp = dccp_sk(sk);
61 const struct dccp_hdr *dh = dccp_hdr(skb);
62 const u8 pkt_type = DCCP_SKB_CB(skb)->dccpd_type;
63 u64 ackno = DCCP_SKB_CB(skb)->dccpd_ack_seq;
64 unsigned char *options = (unsigned char *)dh + dccp_hdr_len(skb);
65 unsigned char *opt_ptr = options;
66 const unsigned char *opt_end = (unsigned char *)dh +
68 struct dccp_options_received *opt_recv = &dp->dccps_options_received;
69 unsigned char opt, len;
75 memset(opt_recv, 0, sizeof(*opt_recv));
78 while (opt_ptr != opt_end) {
83 /* Check if this isn't a single byte option */
84 if (opt > DCCPO_MAX_RESERVED) {
85 if (opt_ptr == opt_end)
86 goto out_invalid_option;
90 goto out_invalid_option;
92 * Remove the type and len fields, leaving
99 if (opt_ptr > opt_end)
100 goto out_invalid_option;
106 case DCCPO_MANDATORY:
108 goto out_invalid_option;
109 if (pkt_type != DCCP_PKT_DATA)
112 case DCCPO_NDP_COUNT:
114 goto out_invalid_option;
116 opt_recv->dccpor_ndp = dccp_decode_value_var(value, len);
117 dccp_pr_debug("%s rx opt: NDP count=%d\n", dccp_role(sk),
118 opt_recv->dccpor_ndp);
124 goto out_invalid_option;
125 rc = dccp_feat_change_recv(sk, opt, *value, value + 1,
128 * When there is a change error, change_recv is
129 * responsible for dealing with it. i.e. reply with an
131 * If the change was mandatory, then we need to die.
134 goto out_invalid_option;
136 case DCCPO_CONFIRM_L:
138 case DCCPO_CONFIRM_R:
140 goto out_invalid_option;
141 if (dccp_feat_confirm_recv(sk, opt, *value,
143 goto out_invalid_option;
145 case DCCPO_ACK_VECTOR_0:
146 case DCCPO_ACK_VECTOR_1:
147 if (pkt_type == DCCP_PKT_DATA)
150 if (dccp_msk(sk)->dccpms_send_ack_vector &&
151 dccp_ackvec_parse(sk, skb, &ackno, opt, value, len))
152 goto out_invalid_option;
154 case DCCPO_TIMESTAMP:
156 goto out_invalid_option;
158 opt_recv->dccpor_timestamp = ntohl(*(__be32 *)value);
160 dp->dccps_timestamp_echo = opt_recv->dccpor_timestamp;
161 dp->dccps_timestamp_time = ktime_get_real();
163 dccp_pr_debug("%s rx opt: TIMESTAMP=%u, ackno=%llu\n",
164 dccp_role(sk), opt_recv->dccpor_timestamp,
166 DCCP_SKB_CB(skb)->dccpd_ack_seq);
168 case DCCPO_TIMESTAMP_ECHO:
169 if (len != 4 && len != 6 && len != 8)
170 goto out_invalid_option;
172 opt_recv->dccpor_timestamp_echo = ntohl(*(__be32 *)value);
174 dccp_pr_debug("%s rx opt: TIMESTAMP_ECHO=%u, len=%d, "
175 "ackno=%llu", dccp_role(sk),
176 opt_recv->dccpor_timestamp_echo,
179 DCCP_SKB_CB(skb)->dccpd_ack_seq);
183 dccp_pr_debug_cat("\n");
188 elapsed_time = ntohs(*(__be16 *)(value + 4));
190 elapsed_time = ntohl(*(__be32 *)(value + 4));
192 dccp_pr_debug_cat(", ELAPSED_TIME=%d\n", elapsed_time);
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("%s rx opt: ELAPSED_TIME=%d\n",
214 dccp_role(sk), elapsed_time);
217 * From RFC 4340, sec. 10.3:
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 DCCP_CRIT("DCCP(%p): option %d(len=%d) not "
245 "implemented, ignoring", sk, opt, len);
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 DCCP_WARN("DCCP(%p): invalid option %d, len=%d", 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 int 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)
295 DCCP_SKB_CB(skb)->dccpd_opt_len += len + 2;
297 to = skb_push(skb, len + 2);
301 memcpy(to, value, len);
305 EXPORT_SYMBOL_GPL(dccp_insert_option);
307 static int dccp_insert_option_ndp(struct sock *sk, struct sk_buff *skb)
309 struct dccp_sock *dp = dccp_sk(sk);
310 int ndp = dp->dccps_ndp_count;
312 if (dccp_non_data_packet(skb))
313 ++dp->dccps_ndp_count;
315 dp->dccps_ndp_count = 0;
319 const int ndp_len = dccp_ndp_len(ndp);
320 const int len = ndp_len + 2;
322 if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
325 DCCP_SKB_CB(skb)->dccpd_opt_len += len;
327 ptr = skb_push(skb, len);
328 *ptr++ = DCCPO_NDP_COUNT;
330 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 int dccp_insert_option_elapsed_time(struct sock *sk, struct sk_buff *skb,
344 const int elapsed_time_len = dccp_elapsed_time_len(elapsed_time);
345 const int len = 2 + elapsed_time_len;
348 if (elapsed_time_len == 0)
351 if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
354 DCCP_SKB_CB(skb)->dccpd_opt_len += len;
356 to = skb_push(skb, len);
357 *to++ = DCCPO_ELAPSED_TIME;
360 if (elapsed_time_len == 2) {
361 const __be16 var16 = htons((u16)elapsed_time);
362 memcpy(to, &var16, 2);
364 const __be32 var32 = htonl(elapsed_time);
365 memcpy(to, &var32, 4);
371 EXPORT_SYMBOL_GPL(dccp_insert_option_elapsed_time);
373 void dccp_timestamp(const struct sock *sk, struct timeval *tv)
375 const struct dccp_sock *dp = dccp_sk(sk);
378 tv->tv_sec -= dp->dccps_epoch.tv_sec;
379 tv->tv_usec -= dp->dccps_epoch.tv_usec;
381 while (tv->tv_usec < 0) {
383 tv->tv_usec += USEC_PER_SEC;
387 EXPORT_SYMBOL_GPL(dccp_timestamp);
389 int dccp_insert_option_timestamp(struct sock *sk, struct sk_buff *skb)
394 dccp_timestamp(sk, &tv);
395 now = htonl(timeval_usecs(&tv) / 10);
396 /* yes this will overflow but that is the point as we want a
397 * 10 usec 32 bit timer which mean it wraps every 11.9 hours */
399 return dccp_insert_option(sk, skb, DCCPO_TIMESTAMP, &now, sizeof(now));
402 EXPORT_SYMBOL_GPL(dccp_insert_option_timestamp);
404 static int dccp_insert_option_timestamp_echo(struct sock *sk,
407 struct dccp_sock *dp = dccp_sk(sk);
409 int len, elapsed_time_len;
411 const suseconds_t delta = ktime_us_delta(ktime_get_real(),
412 dp->dccps_timestamp_time);
413 u32 elapsed_time = delta / 10;
414 elapsed_time_len = dccp_elapsed_time_len(elapsed_time);
415 len = 6 + elapsed_time_len;
417 if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
420 DCCP_SKB_CB(skb)->dccpd_opt_len += len;
422 to = skb_push(skb, len);
423 *to++ = DCCPO_TIMESTAMP_ECHO;
426 tstamp_echo = htonl(dp->dccps_timestamp_echo);
427 memcpy(to, &tstamp_echo, 4);
430 if (elapsed_time_len == 2) {
431 const __be16 var16 = htons((u16)elapsed_time);
432 memcpy(to, &var16, 2);
433 } else if (elapsed_time_len == 4) {
434 const __be32 var32 = htonl(elapsed_time);
435 memcpy(to, &var32, 4);
438 dp->dccps_timestamp_echo = 0;
439 dp->dccps_timestamp_time = ktime_set(0, 0);
443 static int dccp_insert_feat_opt(struct sk_buff *skb, u8 type, u8 feat,
448 if (DCCP_SKB_CB(skb)->dccpd_opt_len + len + 3 > DCCP_MAX_OPT_LEN) {
449 DCCP_WARN("packet too small for feature %d option!\n", feat);
453 DCCP_SKB_CB(skb)->dccpd_opt_len += len + 3;
455 to = skb_push(skb, len + 3);
461 memcpy(to, val, len);
463 dccp_pr_debug("%s(%s (%d), ...), length %d\n",
464 dccp_feat_typename(type),
465 dccp_feat_name(feat), feat, len);
469 static int dccp_insert_options_feat(struct sock *sk, struct sk_buff *skb)
471 struct dccp_sock *dp = dccp_sk(sk);
472 struct dccp_minisock *dmsk = dccp_msk(sk);
473 struct dccp_opt_pend *opt, *next;
476 /* confirm any options [NN opts] */
477 list_for_each_entry_safe(opt, next, &dmsk->dccpms_conf, dccpop_node) {
478 dccp_insert_feat_opt(skb, opt->dccpop_type,
479 opt->dccpop_feat, opt->dccpop_val,
481 /* fear empty confirms */
483 kfree(opt->dccpop_val);
486 INIT_LIST_HEAD(&dmsk->dccpms_conf);
488 /* see which features we need to send */
489 list_for_each_entry(opt, &dmsk->dccpms_pending, dccpop_node) {
490 /* see if we need to send any confirm */
491 if (opt->dccpop_sc) {
492 dccp_insert_feat_opt(skb, opt->dccpop_type + 1,
494 opt->dccpop_sc->dccpoc_val,
495 opt->dccpop_sc->dccpoc_len);
497 BUG_ON(!opt->dccpop_sc->dccpoc_val);
498 kfree(opt->dccpop_sc->dccpoc_val);
499 kfree(opt->dccpop_sc);
500 opt->dccpop_sc = NULL;
503 /* any option not confirmed, re-send it */
504 if (!opt->dccpop_conf) {
505 dccp_insert_feat_opt(skb, opt->dccpop_type,
506 opt->dccpop_feat, opt->dccpop_val,
513 * If this is the master listening sock, we don't set a timer on it. It
514 * should be fine because if the dude doesn't receive our RESPONSE
515 * [which will contain the CHANGE] he will send another REQUEST which
516 * will "retrnasmit" the change.
518 if (change && dp->dccps_role != DCCP_ROLE_LISTEN) {
519 dccp_pr_debug("reset feat negotiation timer %p\n", sk);
521 /* XXX don't reset the timer on re-transmissions. I.e. reset it
522 * only when sending new stuff i guess. Currently the timer
523 * never backs off because on re-transmission it just resets it!
525 inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
526 inet_csk(sk)->icsk_rto, DCCP_RTO_MAX);
532 int dccp_insert_options(struct sock *sk, struct sk_buff *skb)
534 struct dccp_sock *dp = dccp_sk(sk);
535 struct dccp_minisock *dmsk = dccp_msk(sk);
537 DCCP_SKB_CB(skb)->dccpd_opt_len = 0;
539 if (dmsk->dccpms_send_ndp_count &&
540 dccp_insert_option_ndp(sk, skb))
543 if (!dccp_packet_without_ack(skb)) {
544 if (dmsk->dccpms_send_ack_vector &&
545 dccp_ackvec_pending(dp->dccps_hc_rx_ackvec) &&
546 dccp_insert_option_ackvec(sk, skb))
549 if (dp->dccps_timestamp_echo != 0 &&
550 dccp_insert_option_timestamp_echo(sk, skb))
554 if (dp->dccps_hc_rx_insert_options) {
555 if (ccid_hc_rx_insert_options(dp->dccps_hc_rx_ccid, sk, skb))
557 dp->dccps_hc_rx_insert_options = 0;
560 /* Feature negotiation */
561 /* Data packets can't do feat negotiation */
562 if (DCCP_SKB_CB(skb)->dccpd_type != DCCP_PKT_DATA &&
563 DCCP_SKB_CB(skb)->dccpd_type != DCCP_PKT_DATAACK &&
564 dccp_insert_options_feat(sk, skb))
568 * Obtain RTT sample from Request/Response exchange.
569 * This is currently used in CCID 3 initialisation.
571 if (DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_REQUEST &&
572 dccp_insert_option_timestamp(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;