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 #ifdef CONFIG_IP_DCCP_DEBUG
64 const char *debug_prefix = dp->dccps_role == DCCP_ROLE_CLIENT ?
65 "CLIENT rx opt: " : "server rx opt: ";
67 const struct dccp_hdr *dh = dccp_hdr(skb);
68 const u8 pkt_type = DCCP_SKB_CB(skb)->dccpd_type;
69 unsigned char *options = (unsigned char *)dh + dccp_hdr_len(skb);
70 unsigned char *opt_ptr = options;
71 const unsigned char *opt_end = (unsigned char *)dh +
73 struct dccp_options_received *opt_recv = &dp->dccps_options_received;
74 unsigned char opt, len;
80 memset(opt_recv, 0, sizeof(*opt_recv));
83 while (opt_ptr != opt_end) {
88 /* Check if this isn't a single byte option */
89 if (opt > DCCPO_MAX_RESERVED) {
90 if (opt_ptr == opt_end)
91 goto out_invalid_option;
95 goto out_invalid_option;
97 * Remove the type and len fields, leaving
104 if (opt_ptr > opt_end)
105 goto out_invalid_option;
111 case DCCPO_MANDATORY:
113 goto out_invalid_option;
114 if (pkt_type != DCCP_PKT_DATA)
117 case DCCPO_NDP_COUNT:
119 goto out_invalid_option;
121 opt_recv->dccpor_ndp = dccp_decode_value_var(value, len);
122 dccp_pr_debug("%sNDP count=%d\n", debug_prefix,
123 opt_recv->dccpor_ndp);
129 goto out_invalid_option;
130 rc = dccp_feat_change_recv(sk, opt, *value, value + 1,
133 * When there is a change error, change_recv is
134 * responsible for dealing with it. i.e. reply with an
136 * If the change was mandatory, then we need to die.
139 goto out_invalid_option;
141 case DCCPO_CONFIRM_L:
143 case DCCPO_CONFIRM_R:
145 goto out_invalid_option;
146 if (dccp_feat_confirm_recv(sk, opt, *value,
148 goto out_invalid_option;
150 case DCCPO_ACK_VECTOR_0:
151 case DCCPO_ACK_VECTOR_1:
152 if (pkt_type == DCCP_PKT_DATA)
155 if (dccp_msk(sk)->dccpms_send_ack_vector &&
156 dccp_ackvec_parse(sk, skb, opt, value, len))
157 goto out_invalid_option;
159 case DCCPO_TIMESTAMP:
161 goto out_invalid_option;
163 opt_recv->dccpor_timestamp = ntohl(*(__be32 *)value);
165 dp->dccps_timestamp_echo = opt_recv->dccpor_timestamp;
166 dccp_timestamp(sk, &dp->dccps_timestamp_time);
168 dccp_pr_debug("%sTIMESTAMP=%u, ackno=%llu\n",
169 debug_prefix, opt_recv->dccpor_timestamp,
171 DCCP_SKB_CB(skb)->dccpd_ack_seq);
173 case DCCPO_TIMESTAMP_ECHO:
174 if (len != 4 && len != 6 && len != 8)
175 goto out_invalid_option;
177 opt_recv->dccpor_timestamp_echo = ntohl(*(__be32 *)value);
179 dccp_pr_debug("%sTIMESTAMP_ECHO=%u, len=%d, ackno=%llu, ",
181 opt_recv->dccpor_timestamp_echo,
184 DCCP_SKB_CB(skb)->dccpd_ack_seq);
191 elapsed_time = ntohs(*(__be16 *)(value + 4));
193 elapsed_time = ntohl(*(__be32 *)(value + 4));
195 /* Give precedence to the biggest ELAPSED_TIME */
196 if (elapsed_time > opt_recv->dccpor_elapsed_time)
197 opt_recv->dccpor_elapsed_time = elapsed_time;
199 case DCCPO_ELAPSED_TIME:
200 if (len != 2 && len != 4)
201 goto out_invalid_option;
203 if (pkt_type == DCCP_PKT_DATA)
207 elapsed_time = ntohs(*(__be16 *)value);
209 elapsed_time = ntohl(*(__be32 *)value);
211 if (elapsed_time > opt_recv->dccpor_elapsed_time)
212 opt_recv->dccpor_elapsed_time = elapsed_time;
214 dccp_pr_debug("%sELAPSED_TIME=%d\n", debug_prefix,
218 * From RFC 4340, sec. 10.3:
220 * Option numbers 128 through 191 are for
221 * options sent from the HC-Sender to the
222 * HC-Receiver; option numbers 192 through 255
223 * are for options sent from the HC-Receiver to
227 const u16 idx = value - options;
229 if (ccid_hc_rx_parse_options(dp->dccps_hc_rx_ccid, sk,
232 goto out_invalid_option;
236 const u16 idx = value - options;
238 if (ccid_hc_tx_parse_options(dp->dccps_hc_tx_ccid, sk,
241 goto out_invalid_option;
245 pr_info("DCCP(%p): option %d(len=%d) not "
246 "implemented, ignoring\n",
251 if (opt != DCCPO_MANDATORY)
255 /* mandatory was the last byte in option list -> reset connection */
257 goto out_invalid_option;
262 DCCP_INC_STATS_BH(DCCP_MIB_INVALIDOPT);
263 DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_OPTION_ERROR;
264 pr_info("DCCP(%p): invalid option %d, len=%d\n", sk, opt, len);
268 EXPORT_SYMBOL_GPL(dccp_parse_options);
270 static void dccp_encode_value_var(const u32 value, unsigned char *to,
271 const unsigned int len)
274 *to++ = (value & 0xFF000000) >> 24;
276 *to++ = (value & 0xFF0000) >> 16;
278 *to++ = (value & 0xFF00) >> 8;
280 *to++ = (value & 0xFF);
283 static inline int dccp_ndp_len(const int ndp)
285 return likely(ndp <= 0xFF) ? 1 : ndp <= 0xFFFF ? 2 : 3;
288 int dccp_insert_option(struct sock *sk, struct sk_buff *skb,
289 const unsigned char option,
290 const void *value, const unsigned char len)
294 if (DCCP_SKB_CB(skb)->dccpd_opt_len + len + 2 > DCCP_MAX_OPT_LEN)
297 DCCP_SKB_CB(skb)->dccpd_opt_len += len + 2;
299 to = skb_push(skb, len + 2);
303 memcpy(to, value, len);
307 EXPORT_SYMBOL_GPL(dccp_insert_option);
309 static int dccp_insert_option_ndp(struct sock *sk, struct sk_buff *skb)
311 struct dccp_sock *dp = dccp_sk(sk);
312 int ndp = dp->dccps_ndp_count;
314 if (dccp_non_data_packet(skb))
315 ++dp->dccps_ndp_count;
317 dp->dccps_ndp_count = 0;
321 const int ndp_len = dccp_ndp_len(ndp);
322 const int len = ndp_len + 2;
324 if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
327 DCCP_SKB_CB(skb)->dccpd_opt_len += len;
329 ptr = skb_push(skb, len);
330 *ptr++ = DCCPO_NDP_COUNT;
332 dccp_encode_value_var(ndp, ptr, ndp_len);
338 static inline int dccp_elapsed_time_len(const u32 elapsed_time)
340 return elapsed_time == 0 ? 0 : elapsed_time <= 0xFFFF ? 2 : 4;
343 int dccp_insert_option_elapsed_time(struct sock *sk, struct sk_buff *skb,
346 const int elapsed_time_len = dccp_elapsed_time_len(elapsed_time);
347 const int len = 2 + elapsed_time_len;
350 if (elapsed_time_len == 0)
353 if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
356 DCCP_SKB_CB(skb)->dccpd_opt_len += len;
358 to = skb_push(skb, len);
359 *to++ = DCCPO_ELAPSED_TIME;
362 if (elapsed_time_len == 2) {
363 const __be16 var16 = htons((u16)elapsed_time);
364 memcpy(to, &var16, 2);
366 const __be32 var32 = htonl(elapsed_time);
367 memcpy(to, &var32, 4);
373 EXPORT_SYMBOL_GPL(dccp_insert_option_elapsed_time);
375 void dccp_timestamp(const struct sock *sk, struct timeval *tv)
377 const struct dccp_sock *dp = dccp_sk(sk);
380 tv->tv_sec -= dp->dccps_epoch.tv_sec;
381 tv->tv_usec -= dp->dccps_epoch.tv_usec;
383 while (tv->tv_usec < 0) {
385 tv->tv_usec += USEC_PER_SEC;
389 EXPORT_SYMBOL_GPL(dccp_timestamp);
391 int dccp_insert_option_timestamp(struct sock *sk, struct sk_buff *skb)
396 dccp_timestamp(sk, &tv);
397 now = htonl(timeval_usecs(&tv) / 10);
398 /* yes this will overflow but that is the point as we want a
399 * 10 usec 32 bit timer which mean it wraps every 11.9 hours */
401 return dccp_insert_option(sk, skb, DCCPO_TIMESTAMP, &now, sizeof(now));
404 EXPORT_SYMBOL_GPL(dccp_insert_option_timestamp);
406 static int dccp_insert_option_timestamp_echo(struct sock *sk,
409 struct dccp_sock *dp = dccp_sk(sk);
413 int len, elapsed_time_len;
416 dccp_timestamp(sk, &now);
417 elapsed_time = timeval_delta(&now, &dp->dccps_timestamp_time) / 10;
418 elapsed_time_len = dccp_elapsed_time_len(elapsed_time);
419 len = 6 + elapsed_time_len;
421 if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
424 DCCP_SKB_CB(skb)->dccpd_opt_len += len;
426 to = skb_push(skb, len);
427 *to++ = DCCPO_TIMESTAMP_ECHO;
430 tstamp_echo = htonl(dp->dccps_timestamp_echo);
431 memcpy(to, &tstamp_echo, 4);
434 if (elapsed_time_len == 2) {
435 const __be16 var16 = htons((u16)elapsed_time);
436 memcpy(to, &var16, 2);
437 } else if (elapsed_time_len == 4) {
438 const __be32 var32 = htonl(elapsed_time);
439 memcpy(to, &var32, 4);
442 dp->dccps_timestamp_echo = 0;
443 dp->dccps_timestamp_time.tv_sec = 0;
444 dp->dccps_timestamp_time.tv_usec = 0;
448 static int dccp_insert_feat_opt(struct sk_buff *skb, u8 type, u8 feat,
453 if (DCCP_SKB_CB(skb)->dccpd_opt_len + len + 3 > DCCP_MAX_OPT_LEN) {
454 LIMIT_NETDEBUG(KERN_INFO "DCCP: packet too small"
455 " to insert feature %d option!\n", feat);
459 DCCP_SKB_CB(skb)->dccpd_opt_len += len + 3;
461 to = skb_push(skb, len + 3);
467 memcpy(to, val, len);
469 dccp_pr_debug("%s(%s (%d), ...), length %d\n",
470 dccp_feat_typename(type),
471 dccp_feat_name(feat), feat, len);
475 static int dccp_insert_options_feat(struct sock *sk, struct sk_buff *skb)
477 struct dccp_sock *dp = dccp_sk(sk);
478 struct dccp_minisock *dmsk = dccp_msk(sk);
479 struct dccp_opt_pend *opt, *next;
482 /* confirm any options [NN opts] */
483 list_for_each_entry_safe(opt, next, &dmsk->dccpms_conf, dccpop_node) {
484 dccp_insert_feat_opt(skb, opt->dccpop_type,
485 opt->dccpop_feat, opt->dccpop_val,
487 /* fear empty confirms */
489 kfree(opt->dccpop_val);
492 INIT_LIST_HEAD(&dmsk->dccpms_conf);
494 /* see which features we need to send */
495 list_for_each_entry(opt, &dmsk->dccpms_pending, dccpop_node) {
496 /* see if we need to send any confirm */
497 if (opt->dccpop_sc) {
498 dccp_insert_feat_opt(skb, opt->dccpop_type + 1,
500 opt->dccpop_sc->dccpoc_val,
501 opt->dccpop_sc->dccpoc_len);
503 BUG_ON(!opt->dccpop_sc->dccpoc_val);
504 kfree(opt->dccpop_sc->dccpoc_val);
505 kfree(opt->dccpop_sc);
506 opt->dccpop_sc = NULL;
509 /* any option not confirmed, re-send it */
510 if (!opt->dccpop_conf) {
511 dccp_insert_feat_opt(skb, opt->dccpop_type,
512 opt->dccpop_feat, opt->dccpop_val,
519 * If this is the master listening sock, we don't set a timer on it. It
520 * should be fine because if the dude doesn't receive our RESPONSE
521 * [which will contain the CHANGE] he will send another REQUEST which
522 * will "retrnasmit" the change.
524 if (change && dp->dccps_role != DCCP_ROLE_LISTEN) {
525 dccp_pr_debug("reset feat negotiation timer %p\n", sk);
527 /* XXX don't reset the timer on re-transmissions. I.e. reset it
528 * only when sending new stuff i guess. Currently the timer
529 * never backs off because on re-transmission it just resets it!
531 inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
532 inet_csk(sk)->icsk_rto, DCCP_RTO_MAX);
538 int dccp_insert_options(struct sock *sk, struct sk_buff *skb)
540 struct dccp_sock *dp = dccp_sk(sk);
541 struct dccp_minisock *dmsk = dccp_msk(sk);
543 DCCP_SKB_CB(skb)->dccpd_opt_len = 0;
545 if (dmsk->dccpms_send_ndp_count &&
546 dccp_insert_option_ndp(sk, skb))
549 if (!dccp_packet_without_ack(skb)) {
550 if (dmsk->dccpms_send_ack_vector &&
551 dccp_ackvec_pending(dp->dccps_hc_rx_ackvec) &&
552 dccp_insert_option_ackvec(sk, skb))
555 if (dp->dccps_timestamp_echo != 0 &&
556 dccp_insert_option_timestamp_echo(sk, skb))
560 if (dp->dccps_hc_rx_insert_options) {
561 if (ccid_hc_rx_insert_options(dp->dccps_hc_rx_ccid, sk, skb))
563 dp->dccps_hc_rx_insert_options = 0;
565 if (dp->dccps_hc_tx_insert_options) {
566 if (ccid_hc_tx_insert_options(dp->dccps_hc_tx_ccid, sk, skb))
568 dp->dccps_hc_tx_insert_options = 0;
571 /* Feature negotiation */
572 /* Data packets can't do feat negotiation */
573 if (DCCP_SKB_CB(skb)->dccpd_type != DCCP_PKT_DATA &&
574 DCCP_SKB_CB(skb)->dccpd_type != DCCP_PKT_DATAACK &&
575 dccp_insert_options_feat(sk, skb))
578 /* XXX: insert other options when appropriate */
580 if (DCCP_SKB_CB(skb)->dccpd_opt_len != 0) {
581 /* The length of all options has to be a multiple of 4 */
582 int padding = DCCP_SKB_CB(skb)->dccpd_opt_len % 4;
585 padding = 4 - padding;
586 memset(skb_push(skb, padding), 0, padding);
587 DCCP_SKB_CB(skb)->dccpd_opt_len += padding;