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 EXPORT_SYMBOL_GPL(sysctl_dccp_feat_sequence_window);
34 void dccp_minisock_init(struct dccp_minisock *dmsk)
36 dmsk->dccpms_sequence_window = sysctl_dccp_feat_sequence_window;
37 dmsk->dccpms_rx_ccid = sysctl_dccp_feat_rx_ccid;
38 dmsk->dccpms_tx_ccid = sysctl_dccp_feat_tx_ccid;
39 dmsk->dccpms_ack_ratio = sysctl_dccp_feat_ack_ratio;
40 dmsk->dccpms_send_ack_vector = sysctl_dccp_feat_send_ack_vector;
41 dmsk->dccpms_send_ndp_count = sysctl_dccp_feat_send_ndp_count;
44 static u32 dccp_decode_value_var(const unsigned char *bf, const u8 len)
60 int dccp_parse_options(struct sock *sk, struct sk_buff *skb)
62 struct dccp_sock *dp = dccp_sk(sk);
63 const struct dccp_hdr *dh = dccp_hdr(skb);
64 const u8 pkt_type = DCCP_SKB_CB(skb)->dccpd_type;
65 unsigned char *options = (unsigned char *)dh + dccp_hdr_len(skb);
66 unsigned char *opt_ptr = options;
67 const unsigned char *opt_end = (unsigned char *)dh +
69 struct dccp_options_received *opt_recv = &dp->dccps_options_received;
70 unsigned char opt, len;
76 memset(opt_recv, 0, sizeof(*opt_recv));
79 while (opt_ptr != opt_end) {
84 /* Check if this isn't a single byte option */
85 if (opt > DCCPO_MAX_RESERVED) {
86 if (opt_ptr == opt_end)
87 goto out_invalid_option;
91 goto out_invalid_option;
93 * Remove the type and len fields, leaving
100 if (opt_ptr > opt_end)
101 goto out_invalid_option;
107 case DCCPO_MANDATORY:
109 goto out_invalid_option;
110 if (pkt_type != DCCP_PKT_DATA)
113 case DCCPO_NDP_COUNT:
115 goto out_invalid_option;
117 opt_recv->dccpor_ndp = dccp_decode_value_var(value, len);
118 dccp_pr_debug("%s rx opt: NDP count=%d\n", dccp_role(sk),
119 opt_recv->dccpor_ndp);
125 goto out_invalid_option;
126 rc = dccp_feat_change_recv(sk, opt, *value, value + 1,
129 * When there is a change error, change_recv is
130 * responsible for dealing with it. i.e. reply with an
132 * If the change was mandatory, then we need to die.
135 goto out_invalid_option;
137 case DCCPO_CONFIRM_L:
139 case DCCPO_CONFIRM_R:
141 goto out_invalid_option;
142 if (dccp_feat_confirm_recv(sk, opt, *value,
144 goto out_invalid_option;
146 case DCCPO_ACK_VECTOR_0:
147 case DCCPO_ACK_VECTOR_1:
148 if (pkt_type == DCCP_PKT_DATA)
151 if (dccp_msk(sk)->dccpms_send_ack_vector &&
152 dccp_ackvec_parse(sk, skb, opt, value, len))
153 goto out_invalid_option;
155 case DCCPO_TIMESTAMP:
157 goto out_invalid_option;
159 opt_recv->dccpor_timestamp = ntohl(*(__be32 *)value);
161 dp->dccps_timestamp_echo = opt_recv->dccpor_timestamp;
162 dccp_timestamp(sk, &dp->dccps_timestamp_time);
164 dccp_pr_debug("%s rx opt: TIMESTAMP=%u, ackno=%llu\n",
165 dccp_role(sk), opt_recv->dccpor_timestamp,
167 DCCP_SKB_CB(skb)->dccpd_ack_seq);
169 case DCCPO_TIMESTAMP_ECHO:
170 if (len != 4 && len != 6 && len != 8)
171 goto out_invalid_option;
173 opt_recv->dccpor_timestamp_echo = ntohl(*(__be32 *)value);
175 dccp_pr_debug("%s rx opt: TIMESTAMP_ECHO=%u, len=%d, "
176 "ackno=%llu, ", dccp_role(sk),
177 opt_recv->dccpor_timestamp_echo,
180 DCCP_SKB_CB(skb)->dccpd_ack_seq);
187 elapsed_time = ntohs(*(__be16 *)(value + 4));
189 elapsed_time = ntohl(*(__be32 *)(value + 4));
191 /* Give precedence to the biggest ELAPSED_TIME */
192 if (elapsed_time > opt_recv->dccpor_elapsed_time)
193 opt_recv->dccpor_elapsed_time = elapsed_time;
195 case DCCPO_ELAPSED_TIME:
196 if (len != 2 && len != 4)
197 goto out_invalid_option;
199 if (pkt_type == DCCP_PKT_DATA)
203 elapsed_time = ntohs(*(__be16 *)value);
205 elapsed_time = ntohl(*(__be32 *)value);
207 if (elapsed_time > opt_recv->dccpor_elapsed_time)
208 opt_recv->dccpor_elapsed_time = elapsed_time;
210 dccp_pr_debug("%s rx opt: ELAPSED_TIME=%d\n",
211 dccp_role(sk), elapsed_time);
214 * From RFC 4340, sec. 10.3:
216 * Option numbers 128 through 191 are for
217 * options sent from the HC-Sender to the
218 * HC-Receiver; option numbers 192 through 255
219 * are for options sent from the HC-Receiver to
223 const u16 idx = value - options;
225 if (ccid_hc_rx_parse_options(dp->dccps_hc_rx_ccid, sk,
228 goto out_invalid_option;
232 const u16 idx = value - options;
234 if (ccid_hc_tx_parse_options(dp->dccps_hc_tx_ccid, sk,
237 goto out_invalid_option;
241 DCCP_CRIT("DCCP(%p): option %d(len=%d) not "
242 "implemented, ignoring", sk, opt, len);
246 if (opt != DCCPO_MANDATORY)
250 /* mandatory was the last byte in option list -> reset connection */
252 goto out_invalid_option;
257 DCCP_INC_STATS_BH(DCCP_MIB_INVALIDOPT);
258 DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_OPTION_ERROR;
259 DCCP_WARN("DCCP(%p): invalid option %d, len=%d", sk, opt, len);
263 EXPORT_SYMBOL_GPL(dccp_parse_options);
265 static void dccp_encode_value_var(const u32 value, unsigned char *to,
266 const unsigned int len)
269 *to++ = (value & 0xFF000000) >> 24;
271 *to++ = (value & 0xFF0000) >> 16;
273 *to++ = (value & 0xFF00) >> 8;
275 *to++ = (value & 0xFF);
278 static inline int dccp_ndp_len(const int ndp)
280 return likely(ndp <= 0xFF) ? 1 : ndp <= 0xFFFF ? 2 : 3;
283 int dccp_insert_option(struct sock *sk, struct sk_buff *skb,
284 const unsigned char option,
285 const void *value, const unsigned char len)
289 if (DCCP_SKB_CB(skb)->dccpd_opt_len + len + 2 > DCCP_MAX_OPT_LEN)
292 DCCP_SKB_CB(skb)->dccpd_opt_len += len + 2;
294 to = skb_push(skb, len + 2);
298 memcpy(to, value, len);
302 EXPORT_SYMBOL_GPL(dccp_insert_option);
304 static int 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);
333 static inline int dccp_elapsed_time_len(const u32 elapsed_time)
335 return elapsed_time == 0 ? 0 : elapsed_time <= 0xFFFF ? 2 : 4;
338 int dccp_insert_option_elapsed_time(struct sock *sk, struct sk_buff *skb,
341 const int elapsed_time_len = dccp_elapsed_time_len(elapsed_time);
342 const int len = 2 + elapsed_time_len;
345 if (elapsed_time_len == 0)
348 if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
351 DCCP_SKB_CB(skb)->dccpd_opt_len += len;
353 to = skb_push(skb, len);
354 *to++ = DCCPO_ELAPSED_TIME;
357 if (elapsed_time_len == 2) {
358 const __be16 var16 = htons((u16)elapsed_time);
359 memcpy(to, &var16, 2);
361 const __be32 var32 = htonl(elapsed_time);
362 memcpy(to, &var32, 4);
368 EXPORT_SYMBOL_GPL(dccp_insert_option_elapsed_time);
370 void dccp_timestamp(const struct sock *sk, struct timeval *tv)
372 const struct dccp_sock *dp = dccp_sk(sk);
375 tv->tv_sec -= dp->dccps_epoch.tv_sec;
376 tv->tv_usec -= dp->dccps_epoch.tv_usec;
378 while (tv->tv_usec < 0) {
380 tv->tv_usec += USEC_PER_SEC;
384 EXPORT_SYMBOL_GPL(dccp_timestamp);
386 int dccp_insert_option_timestamp(struct sock *sk, struct sk_buff *skb)
391 dccp_timestamp(sk, &tv);
392 now = htonl(timeval_usecs(&tv) / 10);
393 /* yes this will overflow but that is the point as we want a
394 * 10 usec 32 bit timer which mean it wraps every 11.9 hours */
396 return dccp_insert_option(sk, skb, DCCPO_TIMESTAMP, &now, sizeof(now));
399 EXPORT_SYMBOL_GPL(dccp_insert_option_timestamp);
401 static int dccp_insert_option_timestamp_echo(struct sock *sk,
404 struct dccp_sock *dp = dccp_sk(sk);
408 int len, elapsed_time_len;
411 dccp_timestamp(sk, &now);
412 elapsed_time = timeval_delta(&now, &dp->dccps_timestamp_time) / 10;
413 elapsed_time_len = dccp_elapsed_time_len(elapsed_time);
414 len = 6 + elapsed_time_len;
416 if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
419 DCCP_SKB_CB(skb)->dccpd_opt_len += len;
421 to = skb_push(skb, len);
422 *to++ = DCCPO_TIMESTAMP_ECHO;
425 tstamp_echo = htonl(dp->dccps_timestamp_echo);
426 memcpy(to, &tstamp_echo, 4);
429 if (elapsed_time_len == 2) {
430 const __be16 var16 = htons((u16)elapsed_time);
431 memcpy(to, &var16, 2);
432 } else if (elapsed_time_len == 4) {
433 const __be32 var32 = htonl(elapsed_time);
434 memcpy(to, &var32, 4);
437 dp->dccps_timestamp_echo = 0;
438 dp->dccps_timestamp_time.tv_sec = 0;
439 dp->dccps_timestamp_time.tv_usec = 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;
559 if (dp->dccps_hc_tx_insert_options) {
560 if (ccid_hc_tx_insert_options(dp->dccps_hc_tx_ccid, sk, skb))
562 dp->dccps_hc_tx_insert_options = 0;
565 /* Feature negotiation */
566 /* Data packets can't do feat negotiation */
567 if (DCCP_SKB_CB(skb)->dccpd_type != DCCP_PKT_DATA &&
568 DCCP_SKB_CB(skb)->dccpd_type != DCCP_PKT_DATAACK &&
569 dccp_insert_options_feat(sk, skb))
572 /* XXX: insert other options when appropriate */
574 if (DCCP_SKB_CB(skb)->dccpd_opt_len != 0) {
575 /* The length of all options has to be a multiple of 4 */
576 int padding = DCCP_SKB_CB(skb)->dccpd_opt_len % 4;
579 padding = 4 - padding;
580 memset(skb_push(skb, padding), 0, padding);
581 DCCP_SKB_CB(skb)->dccpd_opt_len += padding;