aboutsummaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorAndrea Bittau <a.bittau@cs.ucl.ac.uk>2006-03-20 20:43:56 -0500
committerDavid S. Miller <davem@davemloft.net>2006-03-20 20:43:56 -0500
commitafe00251dd9b53d51de91ff0099961f42bbf3754 (patch)
treea56aa987140662cf3e6e65be402b8591298c5ced
parent2a91aa3967398fb94eccc8da67c82bce9f67afdf (diff)
[DCCP]: Initial feature negotiation implementation
Still needs more work, but boots and doesn't crashes, even does some negotiation! 18:38:52.174934 127.0.0.1.43458 > 127.0.0.1.5001: request <change_l ack_ratio 2, change_r ccid 2, change_l ccid 2> 18:38:52.218526 127.0.0.1.5001 > 127.0.0.1.43458: response <nop, nop, change_l ack_ratio 2, confirm_r ccid 2 2, confirm_l ccid 2 2, confirm_r ack_ratio 2> 18:38:52.185398 127.0.0.1.43458 > 127.0.0.1.5001: <nop, confirm_r ack_ratio 2, ack_vector0 0x00, elapsed_time 212> :-) Signed-off-by: Andrea Bittau <a.bittau@cs.ucl.ac.uk> Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--include/linux/dccp.h35
-rw-r--r--net/dccp/Makefile2
-rw-r--r--net/dccp/feat.c554
-rw-r--r--net/dccp/feat.h28
-rw-r--r--net/dccp/input.c3
-rw-r--r--net/dccp/ipv4.c19
-rw-r--r--net/dccp/minisocks.c4
-rw-r--r--net/dccp/options.c139
-rw-r--r--net/dccp/output.c4
-rw-r--r--net/dccp/proto.c53
-rw-r--r--net/dccp/timer.c12
11 files changed, 847 insertions, 6 deletions
diff --git a/include/linux/dccp.h b/include/linux/dccp.h
index 268b4579d7e5..f91c8a62406d 100644
--- a/include/linux/dccp.h
+++ b/include/linux/dccp.h
@@ -154,6 +154,10 @@ enum {
154 DCCPO_MANDATORY = 1, 154 DCCPO_MANDATORY = 1,
155 DCCPO_MIN_RESERVED = 3, 155 DCCPO_MIN_RESERVED = 3,
156 DCCPO_MAX_RESERVED = 31, 156 DCCPO_MAX_RESERVED = 31,
157 DCCPO_CHANGE_L = 32,
158 DCCPO_CONFIRM_L = 33,
159 DCCPO_CHANGE_R = 34,
160 DCCPO_CONFIRM_R = 35,
157 DCCPO_NDP_COUNT = 37, 161 DCCPO_NDP_COUNT = 37,
158 DCCPO_ACK_VECTOR_0 = 38, 162 DCCPO_ACK_VECTOR_0 = 38,
159 DCCPO_ACK_VECTOR_1 = 39, 163 DCCPO_ACK_VECTOR_1 = 39,
@@ -168,7 +172,9 @@ enum {
168/* DCCP features */ 172/* DCCP features */
169enum { 173enum {
170 DCCPF_RESERVED = 0, 174 DCCPF_RESERVED = 0,
175 DCCPF_CCID = 1,
171 DCCPF_SEQUENCE_WINDOW = 3, 176 DCCPF_SEQUENCE_WINDOW = 3,
177 DCCPF_ACK_RATIO = 5,
172 DCCPF_SEND_ACK_VECTOR = 6, 178 DCCPF_SEND_ACK_VECTOR = 6,
173 DCCPF_SEND_NDP_COUNT = 7, 179 DCCPF_SEND_NDP_COUNT = 7,
174 /* 10-127 reserved */ 180 /* 10-127 reserved */
@@ -176,9 +182,18 @@ enum {
176 DCCPF_MAX_CCID_SPECIFIC = 255, 182 DCCPF_MAX_CCID_SPECIFIC = 255,
177}; 183};
178 184
185/* this structure is argument to DCCP_SOCKOPT_CHANGE_X */
186struct dccp_so_feat {
187 __u8 dccpsf_feat;
188 __u8 *dccpsf_val;
189 __u8 dccpsf_len;
190};
191
179/* DCCP socket options */ 192/* DCCP socket options */
180#define DCCP_SOCKOPT_PACKET_SIZE 1 193#define DCCP_SOCKOPT_PACKET_SIZE 1
181#define DCCP_SOCKOPT_SERVICE 2 194#define DCCP_SOCKOPT_SERVICE 2
195#define DCCP_SOCKOPT_CHANGE_L 3
196#define DCCP_SOCKOPT_CHANGE_R 4
182#define DCCP_SOCKOPT_CCID_RX_INFO 128 197#define DCCP_SOCKOPT_CCID_RX_INFO 128
183#define DCCP_SOCKOPT_CCID_TX_INFO 192 198#define DCCP_SOCKOPT_CCID_TX_INFO 192
184 199
@@ -314,8 +329,8 @@ static inline unsigned int dccp_hdr_len(const struct sk_buff *skb)
314 329
315/* initial values for each feature */ 330/* initial values for each feature */
316#define DCCPF_INITIAL_SEQUENCE_WINDOW 100 331#define DCCPF_INITIAL_SEQUENCE_WINDOW 100
317/* FIXME: for now we're using CCID 2 (TCP-Like) */
318#define DCCPF_INITIAL_CCID 2 332#define DCCPF_INITIAL_CCID 2
333#define DCCPF_INITIAL_ACK_RATIO 2
319#define DCCPF_INITIAL_SEND_ACK_VECTOR 1 334#define DCCPF_INITIAL_SEND_ACK_VECTOR 1
320/* FIXME: for now we're default to 1 but it should really be 0 */ 335/* FIXME: for now we're default to 1 but it should really be 0 */
321#define DCCPF_INITIAL_SEND_NDP_COUNT 1 336#define DCCPF_INITIAL_SEND_NDP_COUNT 1
@@ -335,6 +350,24 @@ struct dccp_options {
335 __u8 dccpo_tx_ccid; 350 __u8 dccpo_tx_ccid;
336 __u8 dccpo_send_ack_vector; 351 __u8 dccpo_send_ack_vector;
337 __u8 dccpo_send_ndp_count; 352 __u8 dccpo_send_ndp_count;
353 __u8 dccpo_ack_ratio;
354 struct list_head dccpo_pending;
355 struct list_head dccpo_conf;
356};
357
358struct dccp_opt_conf {
359 __u8 *dccpoc_val;
360 __u8 dccpoc_len;
361};
362
363struct dccp_opt_pend {
364 struct list_head dccpop_node;
365 __u8 dccpop_type;
366 __u8 dccpop_feat;
367 __u8 *dccpop_val;
368 __u8 dccpop_len;
369 int dccpop_conf;
370 struct dccp_opt_conf *dccpop_sc;
338}; 371};
339 372
340extern void __dccp_options_init(struct dccp_options *dccpo); 373extern void __dccp_options_init(struct dccp_options *dccpo);
diff --git a/net/dccp/Makefile b/net/dccp/Makefile
index 87b27fff6e3b..5736acea1c86 100644
--- a/net/dccp/Makefile
+++ b/net/dccp/Makefile
@@ -4,7 +4,7 @@ dccp_ipv6-y := ipv6.o
4 4
5obj-$(CONFIG_IP_DCCP) += dccp.o 5obj-$(CONFIG_IP_DCCP) += dccp.o
6 6
7dccp-y := ccid.o input.o ipv4.o minisocks.o options.o output.o proto.o \ 7dccp-y := ccid.o feat.o input.o ipv4.o minisocks.o options.o output.o proto.o \
8 timer.o 8 timer.o
9 9
10dccp-$(CONFIG_IP_DCCP_ACKVEC) += ackvec.o 10dccp-$(CONFIG_IP_DCCP_ACKVEC) += ackvec.o
diff --git a/net/dccp/feat.c b/net/dccp/feat.c
new file mode 100644
index 000000000000..99d7b7f9efa9
--- /dev/null
+++ b/net/dccp/feat.c
@@ -0,0 +1,554 @@
1/*
2 * net/dccp/feat.c
3 *
4 * An implementation of the DCCP protocol
5 * Andrea Bittau <a.bittau@cs.ucl.ac.uk>
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version
10 * 2 of the License, or (at your option) any later version.
11 */
12
13#include <linux/config.h>
14#include <linux/module.h>
15
16#include "dccp.h"
17#include "feat.h"
18
19#define DCCP_FEAT_SP_NOAGREE (-123)
20
21int dccp_feat_change(struct sock *sk, u8 type, u8 feature, u8 *val, u8 len,
22 gfp_t gfp)
23{
24 struct dccp_sock *dp = dccp_sk(sk);
25 struct dccp_opt_pend *opt;
26
27 dccp_pr_debug("feat change type=%d feat=%d\n", type, feature);
28
29 /* check if that feature is already being negotiated */
30 list_for_each_entry(opt, &dp->dccps_options.dccpo_pending,
31 dccpop_node) {
32 /* ok we found a negotiation for this option already */
33 if (opt->dccpop_feat == feature && opt->dccpop_type == type) {
34 dccp_pr_debug("Replacing old\n");
35 /* replace */
36 BUG_ON(opt->dccpop_val == NULL);
37 kfree(opt->dccpop_val);
38 opt->dccpop_val = val;
39 opt->dccpop_len = len;
40 opt->dccpop_conf = 0;
41 return 0;
42 }
43 }
44
45 /* negotiation for a new feature */
46 opt = kmalloc(sizeof(*opt), gfp);
47 if (opt == NULL)
48 return -ENOMEM;
49
50 opt->dccpop_type = type;
51 opt->dccpop_feat = feature;
52 opt->dccpop_len = len;
53 opt->dccpop_val = val;
54 opt->dccpop_conf = 0;
55 opt->dccpop_sc = NULL;
56
57 BUG_ON(opt->dccpop_val == NULL);
58
59 list_add_tail(&opt->dccpop_node, &dp->dccps_options.dccpo_pending);
60 return 0;
61}
62
63EXPORT_SYMBOL_GPL(dccp_feat_change);
64
65/* XXX taking only u8 vals */
66static int dccp_feat_update(struct sock *sk, u8 type, u8 feat, u8 val)
67{
68 /* FIXME implement */
69 dccp_pr_debug("changing [%d] feat %d to %d\n", type, feat, val);
70 return 0;
71}
72
73static int dccp_feat_reconcile(struct sock *sk, struct dccp_opt_pend *opt,
74 u8 *rpref, u8 rlen)
75{
76 struct dccp_sock *dp = dccp_sk(sk);
77 u8 *spref, slen, *res = NULL;
78 int i, j, rc, agree = 1;
79
80 BUG_ON(rpref == NULL);
81
82 /* check if we are the black sheep */
83 if (dp->dccps_role == DCCP_ROLE_CLIENT) {
84 spref = rpref;
85 slen = rlen;
86 rpref = opt->dccpop_val;
87 rlen = opt->dccpop_len;
88 } else {
89 spref = opt->dccpop_val;
90 slen = opt->dccpop_len;
91 }
92 /*
93 * Now we have server preference list in spref and client preference in
94 * rpref
95 */
96 BUG_ON(spref == NULL);
97 BUG_ON(rpref == NULL);
98
99 /* FIXME sanity check vals */
100
101 /* Are values in any order? XXX Lame "algorithm" here */
102 /* XXX assume values are 1 byte */
103 for (i = 0; i < slen; i++) {
104 for (j = 0; j < rlen; j++) {
105 if (spref[i] == rpref[j]) {
106 res = &spref[i];
107 break;
108 }
109 }
110 if (res)
111 break;
112 }
113
114 /* we didn't agree on anything */
115 if (res == NULL) {
116 /* confirm previous value */
117 switch (opt->dccpop_feat) {
118 case DCCPF_CCID:
119 /* XXX did i get this right? =P */
120 if (opt->dccpop_type == DCCPO_CHANGE_L)
121 res = &dp->dccps_options.dccpo_tx_ccid;
122 else
123 res = &dp->dccps_options.dccpo_rx_ccid;
124 break;
125
126 default:
127 WARN_ON(1); /* XXX implement res */
128 return -EFAULT;
129 }
130
131 dccp_pr_debug("Don't agree... reconfirming %d\n", *res);
132 agree = 0; /* this is used for mandatory options... */
133 }
134
135 /* need to put result and our preference list */
136 /* XXX assume 1 byte vals */
137 rlen = 1 + opt->dccpop_len;
138 rpref = kmalloc(rlen, GFP_ATOMIC);
139 if (rpref == NULL)
140 return -ENOMEM;
141
142 *rpref = *res;
143 memcpy(&rpref[1], opt->dccpop_val, opt->dccpop_len);
144
145 /* put it in the "confirm queue" */
146 if (opt->dccpop_sc == NULL) {
147 opt->dccpop_sc = kmalloc(sizeof(*opt->dccpop_sc), GFP_ATOMIC);
148 if (opt->dccpop_sc == NULL) {
149 kfree(rpref);
150 return -ENOMEM;
151 }
152 } else {
153 /* recycle the confirm slot */
154 BUG_ON(opt->dccpop_sc->dccpoc_val == NULL);
155 kfree(opt->dccpop_sc->dccpoc_val);
156 dccp_pr_debug("recycling confirm slot\n");
157 }
158 memset(opt->dccpop_sc, 0, sizeof(*opt->dccpop_sc));
159
160 opt->dccpop_sc->dccpoc_val = rpref;
161 opt->dccpop_sc->dccpoc_len = rlen;
162
163 /* update the option on our side [we are about to send the confirm] */
164 rc = dccp_feat_update(sk, opt->dccpop_type, opt->dccpop_feat, *res);
165 if (rc) {
166 kfree(opt->dccpop_sc->dccpoc_val);
167 kfree(opt->dccpop_sc);
168 opt->dccpop_sc = 0;
169 return rc;
170 }
171
172 dccp_pr_debug("Will confirm %d\n", *rpref);
173
174 /* say we want to change to X but we just got a confirm X, suppress our
175 * change
176 */
177 if (!opt->dccpop_conf) {
178 if (*opt->dccpop_val == *res)
179 opt->dccpop_conf = 1;
180 dccp_pr_debug("won't ask for change of same feature\n");
181 }
182
183 return agree ? 0 : DCCP_FEAT_SP_NOAGREE; /* used for mandatory opts */
184}
185
186static int dccp_feat_sp(struct sock *sk, u8 type, u8 feature, u8 *val, u8 len)
187{
188 struct dccp_sock *dp = dccp_sk(sk);
189 struct dccp_opt_pend *opt;
190 int rc = 1;
191 u8 t;
192
193 /*
194 * We received a CHANGE. We gotta match it against our own preference
195 * list. If we got a CHANGE_R it means it's a change for us, so we need
196 * to compare our CHANGE_L list.
197 */
198 if (type == DCCPO_CHANGE_L)
199 t = DCCPO_CHANGE_R;
200 else
201 t = DCCPO_CHANGE_L;
202
203 /* find our preference list for this feature */
204 list_for_each_entry(opt, &dp->dccps_options.dccpo_pending,
205 dccpop_node) {
206 if (opt->dccpop_type != t || opt->dccpop_feat != feature)
207 continue;
208
209 /* find the winner from the two preference lists */
210 rc = dccp_feat_reconcile(sk, opt, val, len);
211 break;
212 }
213
214 /* We didn't deal with the change. This can happen if we have no
215 * preference list for the feature. In fact, it just shouldn't
216 * happen---if we understand a feature, we should have a preference list
217 * with at least the default value.
218 */
219 BUG_ON(rc == 1);
220
221 return rc;
222}
223
224static int dccp_feat_nn(struct sock *sk, u8 type, u8 feature, u8 *val, u8 len)
225{
226 struct dccp_opt_pend *opt;
227 struct dccp_sock *dp = dccp_sk(sk);
228 u8 *copy;
229 int rc;
230
231 /* NN features must be change L */
232 if (type == DCCPO_CHANGE_R) {
233 dccp_pr_debug("received CHANGE_R %d for NN feat %d\n",
234 type, feature);
235 return -EFAULT;
236 }
237
238 /* XXX sanity check opt val */
239
240 /* copy option so we can confirm it */
241 opt = kzalloc(sizeof(*opt), GFP_ATOMIC);
242 if (opt == NULL)
243 return -ENOMEM;
244
245 copy = kmalloc(len, GFP_ATOMIC);
246 if (copy == NULL) {
247 kfree(opt);
248 return -ENOMEM;
249 }
250 memcpy(copy, val, len);
251
252 opt->dccpop_type = DCCPO_CONFIRM_R; /* NN can only confirm R */
253 opt->dccpop_feat = feature;
254 opt->dccpop_val = copy;
255 opt->dccpop_len = len;
256
257 /* change feature */
258 rc = dccp_feat_update(sk, type, feature, *val);
259 if (rc) {
260 kfree(opt->dccpop_val);
261 kfree(opt);
262 return rc;
263 }
264
265 dccp_pr_debug("Confirming NN feature %d (val=%d)\n", feature, *copy);
266 list_add_tail(&opt->dccpop_node, &dp->dccps_options.dccpo_conf);
267
268 return 0;
269}
270
271static void dccp_feat_empty_confirm(struct sock *sk, u8 type, u8 feature)
272{
273 struct dccp_sock *dp = dccp_sk(sk);
274 /* XXX check if other confirms for that are queued and recycle slot */
275 struct dccp_opt_pend *opt = kzalloc(sizeof(*opt), GFP_ATOMIC);
276
277 if (opt == NULL) {
278 /* XXX what do we do? Ignoring should be fine. It's a change
279 * after all =P
280 */
281 return;
282 }
283
284 opt->dccpop_type = type == DCCPO_CHANGE_L ? DCCPO_CONFIRM_R :
285 DCCPO_CONFIRM_L;
286 opt->dccpop_feat = feature;
287 opt->dccpop_val = 0;
288 opt->dccpop_len = 0;
289
290 /* change feature */
291 dccp_pr_debug("Empty confirm feature %d type %d\n", feature, type);
292 list_add_tail(&opt->dccpop_node, &dp->dccps_options.dccpo_conf);
293}
294
295static void dccp_feat_flush_confirm(struct sock *sk)
296{
297 struct dccp_sock *dp = dccp_sk(sk);
298 /* Check if there is anything to confirm in the first place */
299 int yes = !list_empty(&dp->dccps_options.dccpo_conf);
300
301 if (!yes) {
302 struct dccp_opt_pend *opt;
303
304 list_for_each_entry(opt, &dp->dccps_options.dccpo_pending,
305 dccpop_node) {
306 if (opt->dccpop_conf) {
307 yes = 1;
308 break;
309 }
310 }
311 }
312
313 if (!yes)
314 return;
315
316 /* OK there is something to confirm... */
317 /* XXX check if packet is in flight? Send delayed ack?? */
318 if (sk->sk_state == DCCP_OPEN)
319 dccp_send_ack(sk);
320}
321
322int dccp_feat_change_recv(struct sock *sk, u8 type, u8 feature, u8 *val, u8 len)
323{
324 int rc;
325
326 dccp_pr_debug("got feat change type=%d feat=%d\n", type, feature);
327
328 /* figure out if it's SP or NN feature */
329 switch (feature) {
330 /* deal with SP features */
331 case DCCPF_CCID:
332 rc = dccp_feat_sp(sk, type, feature, val, len);
333 break;
334
335 /* deal with NN features */
336 case DCCPF_ACK_RATIO:
337 rc = dccp_feat_nn(sk, type, feature, val, len);
338 break;
339
340 /* XXX implement other features */
341 default:
342 rc = -EFAULT;
343 break;
344 }
345
346 /* check if there were problems changing features */
347 if (rc) {
348 /* If we don't agree on SP, we sent a confirm for old value.
349 * However we propagate rc to caller in case option was
350 * mandatory
351 */
352 if (rc != DCCP_FEAT_SP_NOAGREE)
353 dccp_feat_empty_confirm(sk, type, feature);
354 }
355
356 /* generate the confirm [if required] */
357 dccp_feat_flush_confirm(sk);
358
359 return rc;
360}
361
362EXPORT_SYMBOL_GPL(dccp_feat_change_recv);
363
364int dccp_feat_confirm_recv(struct sock *sk, u8 type, u8 feature,
365 u8 *val, u8 len)
366{
367 u8 t;
368 struct dccp_opt_pend *opt;
369 struct dccp_sock *dp = dccp_sk(sk);
370 int rc = 1;
371 int all_confirmed = 1;
372
373 dccp_pr_debug("got feat confirm type=%d feat=%d\n", type, feature);
374
375 /* XXX sanity check type & feat */
376
377 /* locate our change request */
378 t = type == DCCPO_CONFIRM_L ? DCCPO_CHANGE_R : DCCPO_CHANGE_L;
379
380 list_for_each_entry(opt, &dp->dccps_options.dccpo_pending,
381 dccpop_node) {
382 if (!opt->dccpop_conf && opt->dccpop_type == t &&
383 opt->dccpop_feat == feature) {
384 /* we found it */
385 /* XXX do sanity check */
386
387 opt->dccpop_conf = 1;
388
389 /* We got a confirmation---change the option */
390 dccp_feat_update(sk, opt->dccpop_type,
391 opt->dccpop_feat, *val);
392
393 dccp_pr_debug("feat %d type %d confirmed %d\n",
394 feature, type, *val);
395 rc = 0;
396 break;
397 }
398
399 if (!opt->dccpop_conf)
400 all_confirmed = 0;
401 }
402
403 /* fix re-transmit timer */
404 /* XXX gotta make sure that no option negotiation occurs during
405 * connection shutdown. Consider that the CLOSEREQ is sent and timer is
406 * on. if all options are confirmed it might kill timer which should
407 * remain alive until close is received.
408 */
409 if (all_confirmed) {
410 dccp_pr_debug("clear feat negotiation timer %p\n", sk);
411 inet_csk_clear_xmit_timer(sk, ICSK_TIME_RETRANS);
412 }
413
414 if (rc)
415 dccp_pr_debug("feat %d type %d never requested\n",
416 feature, type);
417 return 0;
418}
419
420EXPORT_SYMBOL_GPL(dccp_feat_confirm_recv);
421
422void dccp_feat_clean(struct sock *sk)
423{
424 struct dccp_sock *dp = dccp_sk(sk);
425 struct dccp_opt_pend *opt, *next;
426
427 list_for_each_entry_safe(opt, next, &dp->dccps_options.dccpo_pending,
428 dccpop_node) {
429 BUG_ON(opt->dccpop_val == NULL);
430 kfree(opt->dccpop_val);
431
432 if (opt->dccpop_sc != NULL) {
433 BUG_ON(opt->dccpop_sc->dccpoc_val == NULL);
434 kfree(opt->dccpop_sc->dccpoc_val);
435 kfree(opt->dccpop_sc);
436 }
437
438 kfree(opt);
439 }
440 INIT_LIST_HEAD(&dp->dccps_options.dccpo_pending);
441
442 list_for_each_entry_safe(opt, next, &dp->dccps_options.dccpo_conf,
443 dccpop_node) {
444 BUG_ON(opt == NULL);
445 if (opt->dccpop_val != NULL)
446 kfree(opt->dccpop_val);
447 kfree(opt);
448 }
449 INIT_LIST_HEAD(&dp->dccps_options.dccpo_conf);
450}
451
452EXPORT_SYMBOL_GPL(dccp_feat_clean);
453
454/* this is to be called only when a listening sock creates its child. It is
455 * assumed by the function---the confirm is not duplicated, but rather it is
456 * "passed on".
457 */
458int dccp_feat_clone(struct sock *oldsk, struct sock *newsk)
459{
460 struct dccp_sock *olddp = dccp_sk(oldsk);
461 struct dccp_sock *newdp = dccp_sk(newsk);
462 struct dccp_opt_pend *opt;
463 int rc = 0;
464
465 INIT_LIST_HEAD(&newdp->dccps_options.dccpo_pending);
466 INIT_LIST_HEAD(&newdp->dccps_options.dccpo_conf);
467
468 list_for_each_entry(opt, &olddp->dccps_options.dccpo_pending,
469 dccpop_node) {
470 struct dccp_opt_pend *newopt;
471 /* copy the value of the option */
472 u8 *val = kmalloc(opt->dccpop_len, GFP_ATOMIC);
473
474 if (val == NULL)
475 goto out_clean;
476 memcpy(val, opt->dccpop_val, opt->dccpop_len);
477
478 newopt = kmalloc(sizeof(*newopt), GFP_ATOMIC);
479 if (newopt == NULL) {
480 kfree(val);
481 goto out_clean;
482 }
483
484 /* insert the option */
485 memcpy(newopt, opt, sizeof(*newopt));
486 newopt->dccpop_val = val;
487 list_add_tail(&newopt->dccpop_node,
488 &newdp->dccps_options.dccpo_pending);
489
490 /* XXX what happens with backlogs and multiple connections at
491 * once...
492 */
493 /* the master socket no longer needs to worry about confirms */
494 opt->dccpop_sc = 0; /* it's not a memleak---new socket has it */
495
496 /* reset state for a new socket */
497 opt->dccpop_conf = 0;
498 }
499
500 /* XXX not doing anything about the conf queue */
501
502out:
503 return rc;
504
505out_clean:
506 dccp_feat_clean(newsk);
507 rc = -ENOMEM;
508 goto out;
509}
510
511EXPORT_SYMBOL_GPL(dccp_feat_clone);
512
513static int __dccp_feat_init(struct sock *sk, u8 type, u8 feat, u8 *val, u8 len)
514{
515 int rc = -ENOMEM;
516 u8 *copy = kmalloc(len, GFP_KERNEL);
517
518 if (copy != NULL) {
519 memcpy(copy, val, len);
520 rc = dccp_feat_change(sk, type, feat, copy, len, GFP_KERNEL);
521 if (rc)
522 kfree(copy);
523 }
524 return rc;
525}
526
527int dccp_feat_init(struct sock *sk)
528{
529 struct dccp_sock *dp = dccp_sk(sk);
530 int rc;
531
532 INIT_LIST_HEAD(&dp->dccps_options.dccpo_pending);
533 INIT_LIST_HEAD(&dp->dccps_options.dccpo_conf);
534
535 /* CCID L */
536 rc = __dccp_feat_init(sk, DCCPO_CHANGE_L, DCCPF_CCID,
537 &dp->dccps_options.dccpo_tx_ccid, 1);
538 if (rc)
539 goto out;
540
541 /* CCID R */
542 rc = __dccp_feat_init(sk, DCCPO_CHANGE_R, DCCPF_CCID,
543 &dp->dccps_options.dccpo_rx_ccid, 1);
544 if (rc)
545 goto out;
546
547 /* Ack ratio */
548 rc = __dccp_feat_init(sk, DCCPO_CHANGE_L, DCCPF_ACK_RATIO,
549 &dp->dccps_options.dccpo_ack_ratio, 1);
550out:
551 return rc;
552}
553
554EXPORT_SYMBOL_GPL(dccp_feat_init);
diff --git a/net/dccp/feat.h b/net/dccp/feat.h
new file mode 100644
index 000000000000..67da06265f14
--- /dev/null
+++ b/net/dccp/feat.h
@@ -0,0 +1,28 @@
1#ifndef _DCCP_FEAT_H
2#define _DCCP_FEAT_H
3/*
4 * net/dccp/feat.h
5 *
6 * An implementation of the DCCP protocol
7 * Copyright (c) 2005 Andrea Bittau <a.bittau@cs.ucl.ac.uk>
8 *
9 * This program is free software; you can redistribute it and/or modify it
10 * under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
12 */
13
14#include <linux/types.h>
15
16struct sock;
17
18extern int dccp_feat_change(struct sock *sk, u8 type, u8 feature,
19 u8 *val, u8 len, gfp_t gfp);
20extern int dccp_feat_change_recv(struct sock *sk, u8 type, u8 feature,
21 u8 *val, u8 len);
22extern int dccp_feat_confirm_recv(struct sock *sk, u8 type, u8 feature,
23 u8 *val, u8 len);
24extern void dccp_feat_clean(struct sock *sk);
25extern int dccp_feat_clone(struct sock *oldsk, struct sock *newsk);
26extern int dccp_feat_init(struct sock *sk);
27
28#endif /* _DCCP_FEAT_H */
diff --git a/net/dccp/input.c b/net/dccp/input.c
index b6cba72b44e8..4b6d43d8b920 100644
--- a/net/dccp/input.c
+++ b/net/dccp/input.c
@@ -300,6 +300,9 @@ static int dccp_rcv_request_sent_state_process(struct sock *sk,
300 goto out_invalid_packet; 300 goto out_invalid_packet;
301 } 301 }
302 302
303 if (dccp_parse_options(sk, skb))
304 goto out_invalid_packet;
305
303 if (dp->dccps_options.dccpo_send_ack_vector && 306 if (dp->dccps_options.dccpo_send_ack_vector &&
304 dccp_ackvec_add(dp->dccps_hc_rx_ackvec, sk, 307 dccp_ackvec_add(dp->dccps_hc_rx_ackvec, sk,
305 DCCP_SKB_CB(skb)->dccpd_seq, 308 DCCP_SKB_CB(skb)->dccpd_seq,
diff --git a/net/dccp/ipv4.c b/net/dccp/ipv4.c
index 38321ad81875..fcfb486f90c2 100644
--- a/net/dccp/ipv4.c
+++ b/net/dccp/ipv4.c
@@ -28,6 +28,7 @@
28#include "ackvec.h" 28#include "ackvec.h"
29#include "ccid.h" 29#include "ccid.h"
30#include "dccp.h" 30#include "dccp.h"
31#include "feat.h"
31 32
32struct inet_hashinfo __cacheline_aligned dccp_hashinfo = { 33struct inet_hashinfo __cacheline_aligned dccp_hashinfo = {
33 .lhash_lock = RW_LOCK_UNLOCKED, 34 .lhash_lock = RW_LOCK_UNLOCKED,
@@ -535,7 +536,8 @@ int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
535 if (req == NULL) 536 if (req == NULL)
536 goto drop; 537 goto drop;
537 538
538 /* FIXME: process options */ 539 if (dccp_parse_options(sk, skb))
540 goto drop;
539 541
540 dccp_openreq_init(req, &dp, skb); 542 dccp_openreq_init(req, &dp, skb);
541 543
@@ -1049,6 +1051,8 @@ int dccp_v4_init_sock(struct sock *sk)
1049 * setsockopt(CCIDs-I-want/accept). -acme 1051 * setsockopt(CCIDs-I-want/accept). -acme
1050 */ 1052 */
1051 if (likely(!dccp_ctl_socket_init)) { 1053 if (likely(!dccp_ctl_socket_init)) {
1054 int rc;
1055
1052 if (dp->dccps_options.dccpo_send_ack_vector) { 1056 if (dp->dccps_options.dccpo_send_ack_vector) {
1053 dp->dccps_hc_rx_ackvec = dccp_ackvec_alloc(GFP_KERNEL); 1057 dp->dccps_hc_rx_ackvec = dccp_ackvec_alloc(GFP_KERNEL);
1054 if (dp->dccps_hc_rx_ackvec == NULL) 1058 if (dp->dccps_hc_rx_ackvec == NULL)
@@ -1069,8 +1073,16 @@ int dccp_v4_init_sock(struct sock *sk)
1069 dp->dccps_hc_rx_ccid = dp->dccps_hc_tx_ccid = NULL; 1073 dp->dccps_hc_rx_ccid = dp->dccps_hc_tx_ccid = NULL;
1070 return -ENOMEM; 1074 return -ENOMEM;
1071 } 1075 }
1072 } else 1076
1077 rc = dccp_feat_init(sk);
1078 if (rc)
1079 return rc;
1080 } else {
1081 /* control socket doesn't need feat nego */
1082 INIT_LIST_HEAD(&dp->dccps_options.dccpo_pending);
1083 INIT_LIST_HEAD(&dp->dccps_options.dccpo_conf);
1073 dccp_ctl_socket_init = 0; 1084 dccp_ctl_socket_init = 0;
1085 }
1074 1086
1075 dccp_init_xmit_timers(sk); 1087 dccp_init_xmit_timers(sk);
1076 icsk->icsk_rto = DCCP_TIMEOUT_INIT; 1088 icsk->icsk_rto = DCCP_TIMEOUT_INIT;
@@ -1118,6 +1130,9 @@ int dccp_v4_destroy_sock(struct sock *sk)
1118 ccid_exit(dp->dccps_hc_tx_ccid, sk); 1130 ccid_exit(dp->dccps_hc_tx_ccid, sk);
1119 dp->dccps_hc_rx_ccid = dp->dccps_hc_tx_ccid = NULL; 1131 dp->dccps_hc_rx_ccid = dp->dccps_hc_tx_ccid = NULL;
1120 1132
1133 /* clean up feature negotiation state */
1134 dccp_feat_clean(sk);
1135
1121 return 0; 1136 return 0;
1122} 1137}
1123 1138
diff --git a/net/dccp/minisocks.c b/net/dccp/minisocks.c
index a60a3e948c36..9e1de5919ee5 100644
--- a/net/dccp/minisocks.c
+++ b/net/dccp/minisocks.c
@@ -22,6 +22,7 @@
22#include "ackvec.h" 22#include "ackvec.h"
23#include "ccid.h" 23#include "ccid.h"
24#include "dccp.h" 24#include "dccp.h"
25#include "feat.h"
25 26
26struct inet_timewait_death_row dccp_death_row = { 27struct inet_timewait_death_row dccp_death_row = {
27 .sysctl_max_tw_buckets = NR_FILE * 2, 28 .sysctl_max_tw_buckets = NR_FILE * 2,
@@ -114,6 +115,9 @@ struct sock *dccp_create_openreq_child(struct sock *sk,
114 newicsk->icsk_rto = DCCP_TIMEOUT_INIT; 115 newicsk->icsk_rto = DCCP_TIMEOUT_INIT;
115 do_gettimeofday(&newdp->dccps_epoch); 116 do_gettimeofday(&newdp->dccps_epoch);
116 117
118 if (dccp_feat_clone(sk, newsk))
119 goto out_free;
120
117 if (newdp->dccps_options.dccpo_send_ack_vector) { 121 if (newdp->dccps_options.dccpo_send_ack_vector) {
118 newdp->dccps_hc_rx_ackvec = 122 newdp->dccps_hc_rx_ackvec =
119 dccp_ackvec_alloc(GFP_ATOMIC); 123 dccp_ackvec_alloc(GFP_ATOMIC);
diff --git a/net/dccp/options.c b/net/dccp/options.c
index 0a76426c9aea..7f99306c8e99 100644
--- a/net/dccp/options.c
+++ b/net/dccp/options.c
@@ -21,12 +21,14 @@
21#include "ackvec.h" 21#include "ackvec.h"
22#include "ccid.h" 22#include "ccid.h"
23#include "dccp.h" 23#include "dccp.h"
24#include "feat.h"
24 25
25/* stores the default values for new connection. may be changed with sysctl */ 26/* stores the default values for new connection. may be changed with sysctl */
26static const struct dccp_options dccpo_default_values = { 27static const struct dccp_options dccpo_default_values = {
27 .dccpo_sequence_window = DCCPF_INITIAL_SEQUENCE_WINDOW, 28 .dccpo_sequence_window = DCCPF_INITIAL_SEQUENCE_WINDOW,
28 .dccpo_rx_ccid = DCCPF_INITIAL_CCID, 29 .dccpo_rx_ccid = DCCPF_INITIAL_CCID,
29 .dccpo_tx_ccid = DCCPF_INITIAL_CCID, 30 .dccpo_tx_ccid = DCCPF_INITIAL_CCID,
31 .dccpo_ack_ratio = DCCPF_INITIAL_ACK_RATIO,
30 .dccpo_send_ack_vector = DCCPF_INITIAL_SEND_ACK_VECTOR, 32 .dccpo_send_ack_vector = DCCPF_INITIAL_SEND_ACK_VECTOR,
31 .dccpo_send_ndp_count = DCCPF_INITIAL_SEND_NDP_COUNT, 33 .dccpo_send_ndp_count = DCCPF_INITIAL_SEND_NDP_COUNT,
32}; 34};
@@ -69,6 +71,8 @@ int dccp_parse_options(struct sock *sk, struct sk_buff *skb)
69 unsigned char opt, len; 71 unsigned char opt, len;
70 unsigned char *value; 72 unsigned char *value;
71 u32 elapsed_time; 73 u32 elapsed_time;
74 int rc;
75 int mandatory = 0;
72 76
73 memset(opt_recv, 0, sizeof(*opt_recv)); 77 memset(opt_recv, 0, sizeof(*opt_recv));
74 78
@@ -100,6 +104,11 @@ int dccp_parse_options(struct sock *sk, struct sk_buff *skb)
100 switch (opt) { 104 switch (opt) {
101 case DCCPO_PADDING: 105 case DCCPO_PADDING:
102 break; 106 break;
107 case DCCPO_MANDATORY:
108 if (mandatory)
109 goto out_invalid_option;
110 mandatory = 1;
111 break;
103 case DCCPO_NDP_COUNT: 112 case DCCPO_NDP_COUNT:
104 if (len > 3) 113 if (len > 3)
105 goto out_invalid_option; 114 goto out_invalid_option;
@@ -108,6 +117,31 @@ int dccp_parse_options(struct sock *sk, struct sk_buff *skb)
108 dccp_pr_debug("%sNDP count=%d\n", debug_prefix, 117 dccp_pr_debug("%sNDP count=%d\n", debug_prefix,
109 opt_recv->dccpor_ndp); 118 opt_recv->dccpor_ndp);
110 break; 119 break;
120 case DCCPO_CHANGE_L:
121 /* fall through */
122 case DCCPO_CHANGE_R:
123 if (len < 2)
124 goto out_invalid_option;
125 rc = dccp_feat_change_recv(sk, opt, *value, value + 1,
126 len - 1);
127 /*
128 * When there is a change error, change_recv is
129 * responsible for dealing with it. i.e. reply with an
130 * empty confirm.
131 * If the change was mandatory, then we need to die.
132 */
133 if (rc && mandatory)
134 goto out_invalid_option;
135 break;
136 case DCCPO_CONFIRM_L:
137 /* fall through */
138 case DCCPO_CONFIRM_R:
139 if (len < 2)
140 goto out_invalid_option;
141 if (dccp_feat_confirm_recv(sk, opt, *value,
142 value + 1, len - 1))
143 goto out_invalid_option;
144 break;
111 case DCCPO_ACK_VECTOR_0: 145 case DCCPO_ACK_VECTOR_0:
112 case DCCPO_ACK_VECTOR_1: 146 case DCCPO_ACK_VECTOR_1:
113 if (pkt_type == DCCP_PKT_DATA) 147 if (pkt_type == DCCP_PKT_DATA)
@@ -208,6 +242,9 @@ int dccp_parse_options(struct sock *sk, struct sk_buff *skb)
208 sk, opt, len); 242 sk, opt, len);
209 break; 243 break;
210 } 244 }
245
246 if (opt != DCCPO_MANDATORY)
247 mandatory = 0;
211 } 248 }
212 249
213 return 0; 250 return 0;
@@ -356,7 +393,7 @@ void dccp_insert_option_timestamp(struct sock *sk, struct sk_buff *skb)
356{ 393{
357 struct timeval tv; 394 struct timeval tv;
358 u32 now; 395 u32 now;
359 396
360 dccp_timestamp(sk, &tv); 397 dccp_timestamp(sk, &tv);
361 now = timeval_usecs(&tv) / 10; 398 now = timeval_usecs(&tv) / 10;
362 /* yes this will overflow but that is the point as we want a 399 /* yes this will overflow but that is the point as we want a
@@ -402,7 +439,7 @@ static void dccp_insert_option_timestamp_echo(struct sock *sk,
402 tstamp_echo = htonl(dp->dccps_timestamp_echo); 439 tstamp_echo = htonl(dp->dccps_timestamp_echo);
403 memcpy(to, &tstamp_echo, 4); 440 memcpy(to, &tstamp_echo, 4);
404 to += 4; 441 to += 4;
405 442
406 if (elapsed_time_len == 2) { 443 if (elapsed_time_len == 2) {
407 const u16 var16 = htons((u16)elapsed_time); 444 const u16 var16 = htons((u16)elapsed_time);
408 memcpy(to, &var16, 2); 445 memcpy(to, &var16, 2);
@@ -421,6 +458,93 @@ static void dccp_insert_option_timestamp_echo(struct sock *sk,
421 dp->dccps_timestamp_time.tv_usec = 0; 458 dp->dccps_timestamp_time.tv_usec = 0;
422} 459}
423 460
461static int dccp_insert_feat_opt(struct sk_buff *skb, u8 type, u8 feat,
462 u8 *val, u8 len)
463{
464 u8 *to;
465
466 if (DCCP_SKB_CB(skb)->dccpd_opt_len + len + 3 > DCCP_MAX_OPT_LEN) {
467 LIMIT_NETDEBUG(KERN_INFO "DCCP: packet too small"
468 " to insert feature %d option!\n", feat);
469 return -1;
470 }
471
472 DCCP_SKB_CB(skb)->dccpd_opt_len += len + 3;
473
474 to = skb_push(skb, len + 3);
475 *to++ = type;
476 *to++ = len + 3;
477 *to++ = feat;
478
479 if (len)
480 memcpy(to, val, len);
481 dccp_pr_debug("option %d feat %d len %d\n", type, feat, len);
482
483 return 0;
484}
485
486static void dccp_insert_feat(struct sock *sk, struct sk_buff *skb)
487{
488 struct dccp_sock *dp = dccp_sk(sk);
489 struct dccp_opt_pend *opt, *next;
490 int change = 0;
491
492 /* confirm any options [NN opts] */
493 list_for_each_entry_safe(opt, next, &dp->dccps_options.dccpo_conf,
494 dccpop_node) {
495 dccp_insert_feat_opt(skb, opt->dccpop_type,
496 opt->dccpop_feat, opt->dccpop_val,
497 opt->dccpop_len);
498 /* fear empty confirms */
499 if (opt->dccpop_val)
500 kfree(opt->dccpop_val);
501 kfree(opt);
502 }
503 INIT_LIST_HEAD(&dp->dccps_options.dccpo_conf);
504
505 /* see which features we need to send */
506 list_for_each_entry(opt, &dp->dccps_options.dccpo_pending,
507 dccpop_node) {
508 /* see if we need to send any confirm */
509 if (opt->dccpop_sc) {
510 dccp_insert_feat_opt(skb, opt->dccpop_type + 1,
511 opt->dccpop_feat,
512 opt->dccpop_sc->dccpoc_val,
513 opt->dccpop_sc->dccpoc_len);
514
515 BUG_ON(!opt->dccpop_sc->dccpoc_val);
516 kfree(opt->dccpop_sc->dccpoc_val);
517 kfree(opt->dccpop_sc);
518 opt->dccpop_sc = NULL;
519 }
520
521 /* any option not confirmed, re-send it */
522 if (!opt->dccpop_conf) {
523 dccp_insert_feat_opt(skb, opt->dccpop_type,
524 opt->dccpop_feat, opt->dccpop_val,
525 opt->dccpop_len);
526 change++;
527 }
528 }
529
530 /* Retransmit timer.
531 * If this is the master listening sock, we don't set a timer on it. It
532 * should be fine because if the dude doesn't receive our RESPONSE
533 * [which will contain the CHANGE] he will send another REQUEST which
534 * will "retrnasmit" the change.
535 */
536 if (change && dp->dccps_role != DCCP_ROLE_LISTEN) {
537 dccp_pr_debug("reset feat negotiation timer %p\n", sk);
538
539 /* XXX don't reset the timer on re-transmissions. I.e. reset it
540 * only when sending new stuff i guess. Currently the timer
541 * never backs off because on re-transmission it just resets it!
542 */
543 inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
544 inet_csk(sk)->icsk_rto, DCCP_RTO_MAX);
545 }
546}
547
424void dccp_insert_options(struct sock *sk, struct sk_buff *skb) 548void dccp_insert_options(struct sock *sk, struct sk_buff *skb)
425{ 549{
426 struct dccp_sock *dp = dccp_sk(sk); 550 struct dccp_sock *dp = dccp_sk(sk);
@@ -447,6 +571,17 @@ void dccp_insert_options(struct sock *sk, struct sk_buff *skb)
447 dp->dccps_hc_tx_insert_options = 0; 571 dp->dccps_hc_tx_insert_options = 0;
448 } 572 }
449 573
574 /* Feature negotiation */
575 switch(DCCP_SKB_CB(skb)->dccpd_type) {
576 /* Data packets can't do feat negotiation */
577 case DCCP_PKT_DATA:
578 case DCCP_PKT_DATAACK:
579 break;
580 default:
581 dccp_insert_feat(sk, skb);
582 break;
583 }
584
450 /* XXX: insert other options when appropriate */ 585 /* XXX: insert other options when appropriate */
451 586
452 if (DCCP_SKB_CB(skb)->dccpd_opt_len != 0) { 587 if (DCCP_SKB_CB(skb)->dccpd_opt_len != 0) {
diff --git a/net/dccp/output.c b/net/dccp/output.c
index efd7ffb903a1..0cc2bcf56522 100644
--- a/net/dccp/output.c
+++ b/net/dccp/output.c
@@ -64,6 +64,10 @@ static int dccp_transmit_skb(struct sock *sk, struct sk_buff *skb)
64 case DCCP_PKT_DATAACK: 64 case DCCP_PKT_DATAACK:
65 break; 65 break;
66 66
67 case DCCP_PKT_REQUEST:
68 set_ack = 0;
69 /* fall through */
70
67 case DCCP_PKT_SYNC: 71 case DCCP_PKT_SYNC:
68 case DCCP_PKT_SYNCACK: 72 case DCCP_PKT_SYNCACK:
69 ackno = dcb->dccpd_seq; 73 ackno = dcb->dccpd_seq;
diff --git a/net/dccp/proto.c b/net/dccp/proto.c
index 81ad24953710..1a8cf8ecfe63 100644
--- a/net/dccp/proto.c
+++ b/net/dccp/proto.c
@@ -37,6 +37,7 @@
37 37
38#include "ccid.h" 38#include "ccid.h"
39#include "dccp.h" 39#include "dccp.h"
40#include "feat.h"
40 41
41DEFINE_SNMP_STAT(struct dccp_mib, dccp_statistics) __read_mostly; 42DEFINE_SNMP_STAT(struct dccp_mib, dccp_statistics) __read_mostly;
42 43
@@ -255,6 +256,39 @@ static int dccp_setsockopt_service(struct sock *sk, const u32 service,
255 return 0; 256 return 0;
256} 257}
257 258
259/* byte 1 is feature. the rest is the preference list */
260static int dccp_setsockopt_change(struct sock *sk, int type,
261 struct dccp_so_feat __user *optval)
262{
263 struct dccp_so_feat opt;
264 u8 *val;
265 int rc;
266
267 if (copy_from_user(&opt, optval, sizeof(opt)))
268 return -EFAULT;
269
270 val = kmalloc(opt.dccpsf_len, GFP_KERNEL);
271 if (!val)
272 return -ENOMEM;
273
274 if (copy_from_user(val, opt.dccpsf_val, opt.dccpsf_len)) {
275 rc = -EFAULT;
276 goto out_free_val;
277 }
278
279 rc = dccp_feat_change(sk, type, opt.dccpsf_feat, val, opt.dccpsf_len,
280 GFP_KERNEL);
281 if (rc)
282 goto out_free_val;
283
284out:
285 return rc;
286
287out_free_val:
288 kfree(val);
289 goto out;
290}
291
258int dccp_setsockopt(struct sock *sk, int level, int optname, 292int dccp_setsockopt(struct sock *sk, int level, int optname,
259 char __user *optval, int optlen) 293 char __user *optval, int optlen)
260{ 294{
@@ -284,6 +318,25 @@ int dccp_setsockopt(struct sock *sk, int level, int optname,
284 case DCCP_SOCKOPT_PACKET_SIZE: 318 case DCCP_SOCKOPT_PACKET_SIZE:
285 dp->dccps_packet_size = val; 319 dp->dccps_packet_size = val;
286 break; 320 break;
321
322 case DCCP_SOCKOPT_CHANGE_L:
323 if (optlen != sizeof(struct dccp_so_feat))
324 err = -EINVAL;
325 else
326 err = dccp_setsockopt_change(sk, DCCPO_CHANGE_L,
327 (struct dccp_so_feat *)
328 optval);
329 break;
330
331 case DCCP_SOCKOPT_CHANGE_R:
332 if (optlen != sizeof(struct dccp_so_feat))
333 err = -EINVAL;
334 else
335 err = dccp_setsockopt_change(sk, DCCPO_CHANGE_R,
336 (struct dccp_so_feat *)
337 optval);
338 break;
339
287 default: 340 default:
288 err = -ENOPROTOOPT; 341 err = -ENOPROTOOPT;
289 break; 342 break;
diff --git a/net/dccp/timer.c b/net/dccp/timer.c
index aa34b576e228..d7c786608ec6 100644
--- a/net/dccp/timer.c
+++ b/net/dccp/timer.c
@@ -141,6 +141,17 @@ static void dccp_retransmit_timer(struct sock *sk)
141{ 141{
142 struct inet_connection_sock *icsk = inet_csk(sk); 142 struct inet_connection_sock *icsk = inet_csk(sk);
143 143
144 /* retransmit timer is used for feature negotiation throughout
145 * connection. In this case, no packet is re-transmitted, but rather an
146 * ack is generated and pending changes are splaced into its options.
147 */
148 if (sk->sk_send_head == NULL) {
149 dccp_pr_debug("feat negotiation retransmit timeout %p\n", sk);
150 if (sk->sk_state == DCCP_OPEN)
151 dccp_send_ack(sk);
152 goto backoff;
153 }
154
144 /* 155 /*
145 * sk->sk_send_head has to have one skb with 156 * sk->sk_send_head has to have one skb with
146 * DCCP_SKB_CB(skb)->dccpd_type set to one of the retransmittable DCCP 157 * DCCP_SKB_CB(skb)->dccpd_type set to one of the retransmittable DCCP
@@ -177,6 +188,7 @@ static void dccp_retransmit_timer(struct sock *sk)
177 goto out; 188 goto out;
178 } 189 }
179 190
191backoff:
180 icsk->icsk_backoff++; 192 icsk->icsk_backoff++;
181 icsk->icsk_retransmits++; 193 icsk->icsk_retransmits++;
182 194