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 dccp_timestamp(sk, &dp->dccps_timestamp_time);
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);
186 elapsed_time = ntohs(*(__be16 *)(value + 4));
188 elapsed_time = ntohl(*(__be32 *)(value + 4));
190 /* Give precedence to the biggest ELAPSED_TIME */
191 if (elapsed_time > opt_recv->dccpor_elapsed_time)
192 opt_recv->dccpor_elapsed_time = elapsed_time;
194 case DCCPO_ELAPSED_TIME:
195 if (len != 2 && len != 4)
196 goto out_invalid_option;
198 if (pkt_type == DCCP_PKT_DATA)
202 elapsed_time = ntohs(*(__be16 *)value);
204 elapsed_time = ntohl(*(__be32 *)value);
206 if (elapsed_time > opt_recv->dccpor_elapsed_time)
207 opt_recv->dccpor_elapsed_time = elapsed_time;
209 dccp_pr_debug("%s rx opt: ELAPSED_TIME=%d\n",
210 dccp_role(sk), elapsed_time);
213 * From RFC 4340, sec. 10.3:
215 * Option numbers 128 through 191 are for
216 * options sent from the HC-Sender to the
217 * HC-Receiver; option numbers 192 through 255
218 * are for options sent from the HC-Receiver to
222 const u16 idx = value - options;
224 if (ccid_hc_rx_parse_options(dp->dccps_hc_rx_ccid, sk,
227 goto out_invalid_option;
231 const u16 idx = value - options;
233 if (ccid_hc_tx_parse_options(dp->dccps_hc_tx_ccid, sk,
236 goto out_invalid_option;
240 DCCP_CRIT("DCCP(%p): option %d(len=%d) not "
241 "implemented, ignoring", sk, opt, len);
245 if (opt != DCCPO_MANDATORY)
249 /* mandatory was the last byte in option list -> reset connection */
251 goto out_invalid_option;
256 DCCP_INC_STATS_BH(DCCP_MIB_INVALIDOPT);
257 DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_OPTION_ERROR;
258 DCCP_WARN("DCCP(%p): invalid option %d, len=%d", sk, opt, len);
262 EXPORT_SYMBOL_GPL(dccp_parse_options);
264 static void dccp_encode_value_var(const u32 value, unsigned char *to,
265 const unsigned int len)
268 *to++ = (value & 0xFF000000) >> 24;
270 *to++ = (value & 0xFF0000) >> 16;
272 *to++ = (value & 0xFF00) >> 8;
274 *to++ = (value & 0xFF);
277 static inline int dccp_ndp_len(const int ndp)
279 return likely(ndp <= 0xFF) ? 1 : ndp <= 0xFFFF ? 2 : 3;
282 int dccp_insert_option(struct sock *sk, struct sk_buff *skb,
283 const unsigned char option,
284 const void *value, const unsigned char len)
288 if (DCCP_SKB_CB(skb)->dccpd_opt_len + len + 2 > DCCP_MAX_OPT_LEN)
291 DCCP_SKB_CB(skb)->dccpd_opt_len += len + 2;
293 to = skb_push(skb, len + 2);
297 memcpy(to, value, len);
301 EXPORT_SYMBOL_GPL(dccp_insert_option);
303 static int dccp_insert_option_ndp(struct sock *sk, struct sk_buff *skb)
305 struct dccp_sock *dp = dccp_sk(sk);
306 int ndp = dp->dccps_ndp_count;
308 if (dccp_non_data_packet(skb))
309 ++dp->dccps_ndp_count;
311 dp->dccps_ndp_count = 0;
315 const int ndp_len = dccp_ndp_len(ndp);
316 const int len = ndp_len + 2;
318 if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
321 DCCP_SKB_CB(skb)->dccpd_opt_len += len;
323 ptr = skb_push(skb, len);
324 *ptr++ = DCCPO_NDP_COUNT;
326 dccp_encode_value_var(ndp, ptr, ndp_len);
332 static inline int dccp_elapsed_time_len(const u32 elapsed_time)
334 return elapsed_time == 0 ? 0 : elapsed_time <= 0xFFFF ? 2 : 4;
337 int dccp_insert_option_elapsed_time(struct sock *sk, struct sk_buff *skb,
340 const int elapsed_time_len = dccp_elapsed_time_len(elapsed_time);
341 const int len = 2 + elapsed_time_len;
344 if (elapsed_time_len == 0)
347 if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
350 DCCP_SKB_CB(skb)->dccpd_opt_len += len;
352 to = skb_push(skb, len);
353 *to++ = DCCPO_ELAPSED_TIME;
356 if (elapsed_time_len == 2) {
357 const __be16 var16 = htons((u16)elapsed_time);
358 memcpy(to, &var16, 2);
360 const __be32 var32 = htonl(elapsed_time);
361 memcpy(to, &var32, 4);
367 EXPORT_SYMBOL_GPL(dccp_insert_option_elapsed_time);
369 void dccp_timestamp(const struct sock *sk, struct timeval *tv)
371 const struct dccp_sock *dp = dccp_sk(sk);
374 tv->tv_sec -= dp->dccps_epoch.tv_sec;
375 tv->tv_usec -= dp->dccps_epoch.tv_usec;
377 while (tv->tv_usec < 0) {
379 tv->tv_usec += USEC_PER_SEC;
383 EXPORT_SYMBOL_GPL(dccp_timestamp);
385 int dccp_insert_option_timestamp(struct sock *sk, struct sk_buff *skb)
390 dccp_timestamp(sk, &tv);
391 now = htonl(timeval_usecs(&tv) / 10);
392 /* yes this will overflow but that is the point as we want a
393 * 10 usec 32 bit timer which mean it wraps every 11.9 hours */
395 return dccp_insert_option(sk, skb, DCCPO_TIMESTAMP, &now, sizeof(now));
398 EXPORT_SYMBOL_GPL(dccp_insert_option_timestamp);
400 static int dccp_insert_option_timestamp_echo(struct sock *sk,
403 struct dccp_sock *dp = dccp_sk(sk);
407 int len, elapsed_time_len;
410 dccp_timestamp(sk, &now);
411 elapsed_time = timeval_delta(&now, &dp->dccps_timestamp_time) / 10;
412 elapsed_time_len = dccp_elapsed_time_len(elapsed_time);
413 len = 6 + elapsed_time_len;
415 if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
418 DCCP_SKB_CB(skb)->dccpd_opt_len += len;
420 to = skb_push(skb, len);
421 *to++ = DCCPO_TIMESTAMP_ECHO;
424 tstamp_echo = htonl(dp->dccps_timestamp_echo);
425 memcpy(to, &tstamp_echo, 4);
428 if (elapsed_time_len == 2) {
429 const __be16 var16 = htons((u16)elapsed_time);
430 memcpy(to, &var16, 2);
431 } else if (elapsed_time_len == 4) {
432 const __be32 var32 = htonl(elapsed_time);
433 memcpy(to, &var32, 4);
436 dp->dccps_timestamp_echo = 0;
437 dp->dccps_timestamp_time.tv_sec = 0;
438 dp->dccps_timestamp_time.tv_usec = 0;
442 static int dccp_insert_feat_opt(struct sk_buff *skb, u8 type, u8 feat,
447 if (DCCP_SKB_CB(skb)->dccpd_opt_len + len + 3 > DCCP_MAX_OPT_LEN) {
448 DCCP_WARN("packet too small for feature %d option!\n", feat);
452 DCCP_SKB_CB(skb)->dccpd_opt_len += len + 3;
454 to = skb_push(skb, len + 3);
460 memcpy(to, val, len);
462 dccp_pr_debug("%s(%s (%d), ...), length %d\n",
463 dccp_feat_typename(type),
464 dccp_feat_name(feat), feat, len);
468 static int dccp_insert_options_feat(struct sock *sk, struct sk_buff *skb)
470 struct dccp_sock *dp = dccp_sk(sk);
471 struct dccp_minisock *dmsk = dccp_msk(sk);
472 struct dccp_opt_pend *opt, *next;
475 /* confirm any options [NN opts] */
476 list_for_each_entry_safe(opt, next, &dmsk->dccpms_conf, dccpop_node) {
477 dccp_insert_feat_opt(skb, opt->dccpop_type,
478 opt->dccpop_feat, opt->dccpop_val,
480 /* fear empty confirms */
482 kfree(opt->dccpop_val);
485 INIT_LIST_HEAD(&dmsk->dccpms_conf);
487 /* see which features we need to send */
488 list_for_each_entry(opt, &dmsk->dccpms_pending, dccpop_node) {
489 /* see if we need to send any confirm */
490 if (opt->dccpop_sc) {
491 dccp_insert_feat_opt(skb, opt->dccpop_type + 1,
493 opt->dccpop_sc->dccpoc_val,
494 opt->dccpop_sc->dccpoc_len);
496 BUG_ON(!opt->dccpop_sc->dccpoc_val);
497 kfree(opt->dccpop_sc->dccpoc_val);
498 kfree(opt->dccpop_sc);
499 opt->dccpop_sc = NULL;
502 /* any option not confirmed, re-send it */
503 if (!opt->dccpop_conf) {
504 dccp_insert_feat_opt(skb, opt->dccpop_type,
505 opt->dccpop_feat, opt->dccpop_val,
512 * If this is the master listening sock, we don't set a timer on it. It
513 * should be fine because if the dude doesn't receive our RESPONSE
514 * [which will contain the CHANGE] he will send another REQUEST which
515 * will "retrnasmit" the change.
517 if (change && dp->dccps_role != DCCP_ROLE_LISTEN) {
518 dccp_pr_debug("reset feat negotiation timer %p\n", sk);
520 /* XXX don't reset the timer on re-transmissions. I.e. reset it
521 * only when sending new stuff i guess. Currently the timer
522 * never backs off because on re-transmission it just resets it!
524 inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
525 inet_csk(sk)->icsk_rto, DCCP_RTO_MAX);
531 int dccp_insert_options(struct sock *sk, struct sk_buff *skb)
533 struct dccp_sock *dp = dccp_sk(sk);
534 struct dccp_minisock *dmsk = dccp_msk(sk);
536 DCCP_SKB_CB(skb)->dccpd_opt_len = 0;
538 if (dmsk->dccpms_send_ndp_count &&
539 dccp_insert_option_ndp(sk, skb))
542 if (!dccp_packet_without_ack(skb)) {
543 if (dmsk->dccpms_send_ack_vector &&
544 dccp_ackvec_pending(dp->dccps_hc_rx_ackvec) &&
545 dccp_insert_option_ackvec(sk, skb))
548 if (dp->dccps_timestamp_echo != 0 &&
549 dccp_insert_option_timestamp_echo(sk, skb))
553 if (dp->dccps_hc_rx_insert_options) {
554 if (ccid_hc_rx_insert_options(dp->dccps_hc_rx_ccid, sk, skb))
556 dp->dccps_hc_rx_insert_options = 0;
559 /* Feature negotiation */
560 /* Data packets can't do feat negotiation */
561 if (DCCP_SKB_CB(skb)->dccpd_type != DCCP_PKT_DATA &&
562 DCCP_SKB_CB(skb)->dccpd_type != DCCP_PKT_DATAACK &&
563 dccp_insert_options_feat(sk, skb))
566 /* XXX: insert other options when appropriate */
568 if (DCCP_SKB_CB(skb)->dccpd_opt_len != 0) {
569 /* The length of all options has to be a multiple of 4 */
570 int padding = DCCP_SKB_CB(skb)->dccpd_opt_len % 4;
573 padding = 4 - padding;
574 memset(skb_push(skb, padding), 0, padding);
575 DCCP_SKB_CB(skb)->dccpd_opt_len += padding;