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 u64 ackno
= DCCP_SKB_CB(skb
)->dccpd_ack_seq
;
66 unsigned char *options
= (unsigned char *)dh
+ dccp_hdr_len(skb
);
67 unsigned char *opt_ptr
= options
;
68 const unsigned char *opt_end
= (unsigned char *)dh
+
70 struct dccp_options_received
*opt_recv
= &dp
->dccps_options_received
;
71 unsigned char opt
, len
;
77 memset(opt_recv
, 0, sizeof(*opt_recv
));
80 while (opt_ptr
!= opt_end
) {
85 /* Check if this isn't a single byte option */
86 if (opt
> DCCPO_MAX_RESERVED
) {
87 if (opt_ptr
== opt_end
)
88 goto out_invalid_option
;
92 goto out_invalid_option
;
94 * Remove the type and len fields, leaving
101 if (opt_ptr
> opt_end
)
102 goto out_invalid_option
;
108 case DCCPO_MANDATORY
:
110 goto out_invalid_option
;
111 if (pkt_type
!= DCCP_PKT_DATA
)
114 case DCCPO_NDP_COUNT
:
116 goto out_invalid_option
;
118 opt_recv
->dccpor_ndp
= dccp_decode_value_var(value
, len
);
119 dccp_pr_debug("%s rx opt: NDP count=%d\n", dccp_role(sk
),
120 opt_recv
->dccpor_ndp
);
126 goto out_invalid_option
;
127 rc
= dccp_feat_change_recv(sk
, opt
, *value
, value
+ 1,
130 * When there is a change error, change_recv is
131 * responsible for dealing with it. i.e. reply with an
133 * If the change was mandatory, then we need to die.
136 goto out_invalid_option
;
138 case DCCPO_CONFIRM_L
:
140 case DCCPO_CONFIRM_R
:
142 goto out_invalid_option
;
143 if (dccp_feat_confirm_recv(sk
, opt
, *value
,
145 goto out_invalid_option
;
147 case DCCPO_ACK_VECTOR_0
:
148 case DCCPO_ACK_VECTOR_1
:
149 if (pkt_type
== DCCP_PKT_DATA
)
152 if (dccp_msk(sk
)->dccpms_send_ack_vector
&&
153 dccp_ackvec_parse(sk
, skb
, &ackno
, opt
, value
, len
))
154 goto out_invalid_option
;
156 case DCCPO_TIMESTAMP
:
158 goto out_invalid_option
;
160 opt_recv
->dccpor_timestamp
= ntohl(*(__be32
*)value
);
162 dp
->dccps_timestamp_echo
= opt_recv
->dccpor_timestamp
;
163 dccp_timestamp(sk
, &dp
->dccps_timestamp_time
);
165 dccp_pr_debug("%s rx opt: TIMESTAMP=%u, ackno=%llu\n",
166 dccp_role(sk
), opt_recv
->dccpor_timestamp
,
168 DCCP_SKB_CB(skb
)->dccpd_ack_seq
);
170 case DCCPO_TIMESTAMP_ECHO
:
171 if (len
!= 4 && len
!= 6 && len
!= 8)
172 goto out_invalid_option
;
174 opt_recv
->dccpor_timestamp_echo
= ntohl(*(__be32
*)value
);
176 dccp_pr_debug("%s rx opt: TIMESTAMP_ECHO=%u, len=%d, "
177 "ackno=%llu, ", dccp_role(sk
),
178 opt_recv
->dccpor_timestamp_echo
,
181 DCCP_SKB_CB(skb
)->dccpd_ack_seq
);
188 elapsed_time
= ntohs(*(__be16
*)(value
+ 4));
190 elapsed_time
= ntohl(*(__be32
*)(value
+ 4));
192 /* Give precedence to the biggest ELAPSED_TIME */
193 if (elapsed_time
> opt_recv
->dccpor_elapsed_time
)
194 opt_recv
->dccpor_elapsed_time
= elapsed_time
;
196 case DCCPO_ELAPSED_TIME
:
197 if (len
!= 2 && len
!= 4)
198 goto out_invalid_option
;
200 if (pkt_type
== DCCP_PKT_DATA
)
204 elapsed_time
= ntohs(*(__be16
*)value
);
206 elapsed_time
= ntohl(*(__be32
*)value
);
208 if (elapsed_time
> opt_recv
->dccpor_elapsed_time
)
209 opt_recv
->dccpor_elapsed_time
= elapsed_time
;
211 dccp_pr_debug("%s rx opt: ELAPSED_TIME=%d\n",
212 dccp_role(sk
), elapsed_time
);
215 * From RFC 4340, sec. 10.3:
217 * Option numbers 128 through 191 are for
218 * options sent from the HC-Sender to the
219 * HC-Receiver; option numbers 192 through 255
220 * are for options sent from the HC-Receiver to
224 const u16 idx
= value
- options
;
226 if (ccid_hc_rx_parse_options(dp
->dccps_hc_rx_ccid
, sk
,
229 goto out_invalid_option
;
233 const u16 idx
= value
- options
;
235 if (ccid_hc_tx_parse_options(dp
->dccps_hc_tx_ccid
, sk
,
238 goto out_invalid_option
;
242 DCCP_CRIT("DCCP(%p): option %d(len=%d) not "
243 "implemented, ignoring", sk
, opt
, len
);
247 if (opt
!= DCCPO_MANDATORY
)
251 /* mandatory was the last byte in option list -> reset connection */
253 goto out_invalid_option
;
258 DCCP_INC_STATS_BH(DCCP_MIB_INVALIDOPT
);
259 DCCP_SKB_CB(skb
)->dccpd_reset_code
= DCCP_RESET_CODE_OPTION_ERROR
;
260 DCCP_WARN("DCCP(%p): invalid option %d, len=%d", sk
, opt
, len
);
264 EXPORT_SYMBOL_GPL(dccp_parse_options
);
266 static void dccp_encode_value_var(const u32 value
, unsigned char *to
,
267 const unsigned int len
)
270 *to
++ = (value
& 0xFF000000) >> 24;
272 *to
++ = (value
& 0xFF0000) >> 16;
274 *to
++ = (value
& 0xFF00) >> 8;
276 *to
++ = (value
& 0xFF);
279 static inline int dccp_ndp_len(const int ndp
)
281 return likely(ndp
<= 0xFF) ? 1 : ndp
<= 0xFFFF ? 2 : 3;
284 int dccp_insert_option(struct sock
*sk
, struct sk_buff
*skb
,
285 const unsigned char option
,
286 const void *value
, const unsigned char len
)
290 if (DCCP_SKB_CB(skb
)->dccpd_opt_len
+ len
+ 2 > DCCP_MAX_OPT_LEN
)
293 DCCP_SKB_CB(skb
)->dccpd_opt_len
+= len
+ 2;
295 to
= skb_push(skb
, len
+ 2);
299 memcpy(to
, value
, len
);
303 EXPORT_SYMBOL_GPL(dccp_insert_option
);
305 static int dccp_insert_option_ndp(struct sock
*sk
, struct sk_buff
*skb
)
307 struct dccp_sock
*dp
= dccp_sk(sk
);
308 int ndp
= dp
->dccps_ndp_count
;
310 if (dccp_non_data_packet(skb
))
311 ++dp
->dccps_ndp_count
;
313 dp
->dccps_ndp_count
= 0;
317 const int ndp_len
= dccp_ndp_len(ndp
);
318 const int len
= ndp_len
+ 2;
320 if (DCCP_SKB_CB(skb
)->dccpd_opt_len
+ len
> DCCP_MAX_OPT_LEN
)
323 DCCP_SKB_CB(skb
)->dccpd_opt_len
+= len
;
325 ptr
= skb_push(skb
, len
);
326 *ptr
++ = DCCPO_NDP_COUNT
;
328 dccp_encode_value_var(ndp
, ptr
, ndp_len
);
334 static inline int dccp_elapsed_time_len(const u32 elapsed_time
)
336 return elapsed_time
== 0 ? 0 : elapsed_time
<= 0xFFFF ? 2 : 4;
339 int dccp_insert_option_elapsed_time(struct sock
*sk
, struct sk_buff
*skb
,
342 const int elapsed_time_len
= dccp_elapsed_time_len(elapsed_time
);
343 const int len
= 2 + elapsed_time_len
;
346 if (elapsed_time_len
== 0)
349 if (DCCP_SKB_CB(skb
)->dccpd_opt_len
+ len
> DCCP_MAX_OPT_LEN
)
352 DCCP_SKB_CB(skb
)->dccpd_opt_len
+= len
;
354 to
= skb_push(skb
, len
);
355 *to
++ = DCCPO_ELAPSED_TIME
;
358 if (elapsed_time_len
== 2) {
359 const __be16 var16
= htons((u16
)elapsed_time
);
360 memcpy(to
, &var16
, 2);
362 const __be32 var32
= htonl(elapsed_time
);
363 memcpy(to
, &var32
, 4);
369 EXPORT_SYMBOL_GPL(dccp_insert_option_elapsed_time
);
371 void dccp_timestamp(const struct sock
*sk
, struct timeval
*tv
)
373 const struct dccp_sock
*dp
= dccp_sk(sk
);
376 tv
->tv_sec
-= dp
->dccps_epoch
.tv_sec
;
377 tv
->tv_usec
-= dp
->dccps_epoch
.tv_usec
;
379 while (tv
->tv_usec
< 0) {
381 tv
->tv_usec
+= USEC_PER_SEC
;
385 EXPORT_SYMBOL_GPL(dccp_timestamp
);
387 int dccp_insert_option_timestamp(struct sock
*sk
, struct sk_buff
*skb
)
392 dccp_timestamp(sk
, &tv
);
393 now
= htonl(timeval_usecs(&tv
) / 10);
394 /* yes this will overflow but that is the point as we want a
395 * 10 usec 32 bit timer which mean it wraps every 11.9 hours */
397 return dccp_insert_option(sk
, skb
, DCCPO_TIMESTAMP
, &now
, sizeof(now
));
400 EXPORT_SYMBOL_GPL(dccp_insert_option_timestamp
);
402 static int dccp_insert_option_timestamp_echo(struct sock
*sk
,
405 struct dccp_sock
*dp
= dccp_sk(sk
);
409 int len
, elapsed_time_len
;
412 dccp_timestamp(sk
, &now
);
413 elapsed_time
= timeval_delta(&now
, &dp
->dccps_timestamp_time
) / 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
.tv_sec
= 0;
440 dp
->dccps_timestamp_time
.tv_usec
= 0;
444 static int dccp_insert_feat_opt(struct sk_buff
*skb
, u8 type
, u8 feat
,
449 if (DCCP_SKB_CB(skb
)->dccpd_opt_len
+ len
+ 3 > DCCP_MAX_OPT_LEN
) {
450 DCCP_WARN("packet too small for feature %d option!\n", feat
);
454 DCCP_SKB_CB(skb
)->dccpd_opt_len
+= len
+ 3;
456 to
= skb_push(skb
, len
+ 3);
462 memcpy(to
, val
, len
);
464 dccp_pr_debug("%s(%s (%d), ...), length %d\n",
465 dccp_feat_typename(type
),
466 dccp_feat_name(feat
), feat
, len
);
470 static int dccp_insert_options_feat(struct sock
*sk
, struct sk_buff
*skb
)
472 struct dccp_sock
*dp
= dccp_sk(sk
);
473 struct dccp_minisock
*dmsk
= dccp_msk(sk
);
474 struct dccp_opt_pend
*opt
, *next
;
477 /* confirm any options [NN opts] */
478 list_for_each_entry_safe(opt
, next
, &dmsk
->dccpms_conf
, dccpop_node
) {
479 dccp_insert_feat_opt(skb
, opt
->dccpop_type
,
480 opt
->dccpop_feat
, opt
->dccpop_val
,
482 /* fear empty confirms */
484 kfree(opt
->dccpop_val
);
487 INIT_LIST_HEAD(&dmsk
->dccpms_conf
);
489 /* see which features we need to send */
490 list_for_each_entry(opt
, &dmsk
->dccpms_pending
, dccpop_node
) {
491 /* see if we need to send any confirm */
492 if (opt
->dccpop_sc
) {
493 dccp_insert_feat_opt(skb
, opt
->dccpop_type
+ 1,
495 opt
->dccpop_sc
->dccpoc_val
,
496 opt
->dccpop_sc
->dccpoc_len
);
498 BUG_ON(!opt
->dccpop_sc
->dccpoc_val
);
499 kfree(opt
->dccpop_sc
->dccpoc_val
);
500 kfree(opt
->dccpop_sc
);
501 opt
->dccpop_sc
= NULL
;
504 /* any option not confirmed, re-send it */
505 if (!opt
->dccpop_conf
) {
506 dccp_insert_feat_opt(skb
, opt
->dccpop_type
,
507 opt
->dccpop_feat
, opt
->dccpop_val
,
514 * If this is the master listening sock, we don't set a timer on it. It
515 * should be fine because if the dude doesn't receive our RESPONSE
516 * [which will contain the CHANGE] he will send another REQUEST which
517 * will "retrnasmit" the change.
519 if (change
&& dp
->dccps_role
!= DCCP_ROLE_LISTEN
) {
520 dccp_pr_debug("reset feat negotiation timer %p\n", sk
);
522 /* XXX don't reset the timer on re-transmissions. I.e. reset it
523 * only when sending new stuff i guess. Currently the timer
524 * never backs off because on re-transmission it just resets it!
526 inet_csk_reset_xmit_timer(sk
, ICSK_TIME_RETRANS
,
527 inet_csk(sk
)->icsk_rto
, DCCP_RTO_MAX
);
533 int dccp_insert_options(struct sock
*sk
, struct sk_buff
*skb
)
535 struct dccp_sock
*dp
= dccp_sk(sk
);
536 struct dccp_minisock
*dmsk
= dccp_msk(sk
);
538 DCCP_SKB_CB(skb
)->dccpd_opt_len
= 0;
540 if (dmsk
->dccpms_send_ndp_count
&&
541 dccp_insert_option_ndp(sk
, skb
))
544 if (!dccp_packet_without_ack(skb
)) {
545 if (dmsk
->dccpms_send_ack_vector
&&
546 dccp_ackvec_pending(dp
->dccps_hc_rx_ackvec
) &&
547 dccp_insert_option_ackvec(sk
, skb
))
550 if (dp
->dccps_timestamp_echo
!= 0 &&
551 dccp_insert_option_timestamp_echo(sk
, skb
))
555 if (dp
->dccps_hc_rx_insert_options
) {
556 if (ccid_hc_rx_insert_options(dp
->dccps_hc_rx_ccid
, sk
, skb
))
558 dp
->dccps_hc_rx_insert_options
= 0;
561 /* Feature negotiation */
562 /* Data packets can't do feat negotiation */
563 if (DCCP_SKB_CB(skb
)->dccpd_type
!= DCCP_PKT_DATA
&&
564 DCCP_SKB_CB(skb
)->dccpd_type
!= DCCP_PKT_DATAACK
&&
565 dccp_insert_options_feat(sk
, skb
))
568 /* XXX: insert other options when appropriate */
570 if (DCCP_SKB_CB(skb
)->dccpd_opt_len
!= 0) {
571 /* The length of all options has to be a multiple of 4 */
572 int padding
= DCCP_SKB_CB(skb
)->dccpd_opt_len
% 4;
575 padding
= 4 - padding
;
576 memset(skb_push(skb
, padding
), 0, padding
);
577 DCCP_SKB_CB(skb
)->dccpd_opt_len
+= padding
;