4 * An implementation of the DCCP protocol
5 * Andrea Bittau <a.bittau@cs.ucl.ac.uk>
9 * o Feature negotiation is coordinated with connection setup (as in TCP), wild
10 * changes of parameters of an established connection are not supported.
11 * o All currently known SP features have 1-byte quantities. If in the future
12 * extensions of RFCs 4340..42 define features with item lengths larger than
13 * one byte, a feature-specific extension of the code will be required.
15 * This program is free software; you can redistribute it and/or
16 * modify it under the terms of the GNU General Public License
17 * as published by the Free Software Foundation; either version
18 * 2 of the License, or (at your option) any later version.
21 #include <linux/module.h>
26 #define DCCP_FEAT_SP_NOAGREE (-123)
29 u8 feat_num
; /* DCCPF_xxx */
30 enum dccp_feat_type rxtx
; /* RX or TX */
31 enum dccp_feat_type reconciliation
; /* SP or NN */
32 u8 default_value
; /* as in 6.4 */
34 * Lookup table for location and type of features (from RFC 4340/4342)
35 * +--------------------------+----+-----+----+----+---------+-----------+
36 * | Feature | Location | Reconc. | Initial | Section |
37 * | | RX | TX | SP | NN | Value | Reference |
38 * +--------------------------+----+-----+----+----+---------+-----------+
39 * | DCCPF_CCID | | X | X | | 2 | 10 |
40 * | DCCPF_SHORT_SEQNOS | | X | X | | 0 | 7.6.1 |
41 * | DCCPF_SEQUENCE_WINDOW | | X | | X | 100 | 7.5.2 |
42 * | DCCPF_ECN_INCAPABLE | X | | X | | 0 | 12.1 |
43 * | DCCPF_ACK_RATIO | | X | | X | 2 | 11.3 |
44 * | DCCPF_SEND_ACK_VECTOR | X | | X | | 0 | 11.5 |
45 * | DCCPF_SEND_NDP_COUNT | | X | X | | 0 | 7.7.2 |
46 * | DCCPF_MIN_CSUM_COVER | X | | X | | 0 | 9.2.1 |
47 * | DCCPF_DATA_CHECKSUM | X | | X | | 0 | 9.3.1 |
48 * | DCCPF_SEND_LEV_RATE | X | | X | | 0 | 4342/8.4 |
49 * +--------------------------+----+-----+----+----+---------+-----------+
51 } dccp_feat_table
[] = {
52 { DCCPF_CCID
, FEAT_AT_TX
, FEAT_SP
, 2 },
53 { DCCPF_SHORT_SEQNOS
, FEAT_AT_TX
, FEAT_SP
, 0 },
54 { DCCPF_SEQUENCE_WINDOW
, FEAT_AT_TX
, FEAT_NN
, 100 },
55 { DCCPF_ECN_INCAPABLE
, FEAT_AT_RX
, FEAT_SP
, 0 },
56 { DCCPF_ACK_RATIO
, FEAT_AT_TX
, FEAT_NN
, 2 },
57 { DCCPF_SEND_ACK_VECTOR
, FEAT_AT_RX
, FEAT_SP
, 0 },
58 { DCCPF_SEND_NDP_COUNT
, FEAT_AT_TX
, FEAT_SP
, 0 },
59 { DCCPF_MIN_CSUM_COVER
, FEAT_AT_RX
, FEAT_SP
, 0 },
60 { DCCPF_DATA_CHECKSUM
, FEAT_AT_RX
, FEAT_SP
, 0 },
61 { DCCPF_SEND_LEV_RATE
, FEAT_AT_RX
, FEAT_SP
, 0 },
63 #define DCCP_FEAT_SUPPORTED_MAX ARRAY_SIZE(dccp_feat_table)
66 * dccp_feat_index - Hash function to map feature number into array position
67 * Returns consecutive array index or -1 if the feature is not understood.
69 static int dccp_feat_index(u8 feat_num
)
71 /* The first 9 entries are occupied by the types from RFC 4340, 6.4 */
72 if (feat_num
> DCCPF_RESERVED
&& feat_num
<= DCCPF_DATA_CHECKSUM
)
76 * Other features: add cases for new feature types here after adding
77 * them to the above table.
80 case DCCPF_SEND_LEV_RATE
:
81 return DCCP_FEAT_SUPPORTED_MAX
- 1;
86 static u8
dccp_feat_type(u8 feat_num
)
88 int idx
= dccp_feat_index(feat_num
);
92 return dccp_feat_table
[idx
].reconciliation
;
95 static int dccp_feat_default_value(u8 feat_num
)
97 int idx
= dccp_feat_index(feat_num
);
99 * There are no default values for unknown features, so encountering a
100 * negative index here indicates a serious problem somewhere else.
102 DCCP_BUG_ON(idx
< 0);
104 return idx
< 0 ? 0 : dccp_feat_table
[idx
].default_value
;
107 /* Test for "Req'd" feature (RFC 4340, 6.4) */
108 static inline int dccp_feat_must_be_understood(u8 feat_num
)
110 return feat_num
== DCCPF_CCID
|| feat_num
== DCCPF_SHORT_SEQNOS
||
111 feat_num
== DCCPF_SEQUENCE_WINDOW
;
114 /* copy constructor, fval must not already contain allocated memory */
115 static int dccp_feat_clone_sp_val(dccp_feat_val
*fval
, u8
const *val
, u8 len
)
118 if (fval
->sp
.len
> 0) {
119 fval
->sp
.vec
= kmemdup(val
, len
, gfp_any());
120 if (fval
->sp
.vec
== NULL
) {
128 static void dccp_feat_val_destructor(u8 feat_num
, dccp_feat_val
*val
)
130 if (unlikely(val
== NULL
))
132 if (dccp_feat_type(feat_num
) == FEAT_SP
)
134 memset(val
, 0, sizeof(*val
));
137 static struct dccp_feat_entry
*
138 dccp_feat_clone_entry(struct dccp_feat_entry
const *original
)
140 struct dccp_feat_entry
*new;
141 u8 type
= dccp_feat_type(original
->feat_num
);
143 if (type
== FEAT_UNKNOWN
)
146 new = kmemdup(original
, sizeof(struct dccp_feat_entry
), gfp_any());
150 if (type
== FEAT_SP
&& dccp_feat_clone_sp_val(&new->val
,
151 original
->val
.sp
.vec
,
152 original
->val
.sp
.len
)) {
159 static void dccp_feat_entry_destructor(struct dccp_feat_entry
*entry
)
162 dccp_feat_val_destructor(entry
->feat_num
, &entry
->val
);
168 * List management functions
170 * Feature negotiation lists rely on and maintain the following invariants:
171 * - each feat_num in the list is known, i.e. we know its type and default value
172 * - each feat_num/is_local combination is unique (old entries are overwritten)
173 * - SP values are always freshly allocated
174 * - list is sorted in increasing order of feature number (faster lookup)
176 static struct dccp_feat_entry
*dccp_feat_list_lookup(struct list_head
*fn_list
,
177 u8 feat_num
, bool is_local
)
179 struct dccp_feat_entry
*entry
;
181 list_for_each_entry(entry
, fn_list
, node
) {
182 if (entry
->feat_num
== feat_num
&& entry
->is_local
== is_local
)
184 else if (entry
->feat_num
> feat_num
)
191 * dccp_feat_entry_new - Central list update routine (called by all others)
192 * @head: list to add to
193 * @feat: feature number
194 * @local: whether the local (1) or remote feature with number @feat is meant
195 * This is the only constructor and serves to ensure the above invariants.
197 static struct dccp_feat_entry
*
198 dccp_feat_entry_new(struct list_head
*head
, u8 feat
, bool local
)
200 struct dccp_feat_entry
*entry
;
202 list_for_each_entry(entry
, head
, node
)
203 if (entry
->feat_num
== feat
&& entry
->is_local
== local
) {
204 dccp_feat_val_destructor(entry
->feat_num
, &entry
->val
);
206 } else if (entry
->feat_num
> feat
) {
211 entry
= kmalloc(sizeof(*entry
), gfp_any());
213 entry
->feat_num
= feat
;
214 entry
->is_local
= local
;
215 list_add_tail(&entry
->node
, head
);
221 * dccp_feat_push_change - Add/overwrite a Change option in the list
222 * @fn_list: feature-negotiation list to update
223 * @feat: one of %dccp_feature_numbers
224 * @local: whether local (1) or remote (0) @feat_num is meant
225 * @needs_mandatory: whether to use Mandatory feature negotiation options
226 * @fval: pointer to NN/SP value to be inserted (will be copied)
228 static int dccp_feat_push_change(struct list_head
*fn_list
, u8 feat
, u8 local
,
229 u8 mandatory
, dccp_feat_val
*fval
)
231 struct dccp_feat_entry
*new = dccp_feat_entry_new(fn_list
, feat
, local
);
236 new->feat_num
= feat
;
237 new->is_local
= local
;
238 new->state
= FEAT_INITIALISING
;
239 new->needs_confirm
= 0;
240 new->empty_confirm
= 0;
242 new->needs_mandatory
= mandatory
;
248 * dccp_feat_push_confirm - Add a Confirm entry to the FN list
249 * @fn_list: feature-negotiation list to add to
250 * @feat: one of %dccp_feature_numbers
251 * @local: whether local (1) or remote (0) @feat_num is being confirmed
252 * @fval: pointer to NN/SP value to be inserted or NULL
253 * Returns 0 on success, a Reset code for further processing otherwise.
255 static int dccp_feat_push_confirm(struct list_head
*fn_list
, u8 feat
, u8 local
,
258 struct dccp_feat_entry
*new = dccp_feat_entry_new(fn_list
, feat
, local
);
261 return DCCP_RESET_CODE_TOO_BUSY
;
263 new->feat_num
= feat
;
264 new->is_local
= local
;
265 new->state
= FEAT_STABLE
; /* transition in 6.6.2 */
266 new->needs_confirm
= 1;
267 new->empty_confirm
= (fval
== NULL
);
268 new->val
.nn
= 0; /* zeroes the whole structure */
269 if (!new->empty_confirm
)
271 new->needs_mandatory
= 0;
276 static int dccp_push_empty_confirm(struct list_head
*fn_list
, u8 feat
, u8 local
)
278 return dccp_feat_push_confirm(fn_list
, feat
, local
, NULL
);
281 static inline void dccp_feat_list_pop(struct dccp_feat_entry
*entry
)
283 list_del(&entry
->node
);
284 dccp_feat_entry_destructor(entry
);
287 void dccp_feat_list_purge(struct list_head
*fn_list
)
289 struct dccp_feat_entry
*entry
, *next
;
291 list_for_each_entry_safe(entry
, next
, fn_list
, node
)
292 dccp_feat_entry_destructor(entry
);
293 INIT_LIST_HEAD(fn_list
);
295 EXPORT_SYMBOL_GPL(dccp_feat_list_purge
);
297 /* generate @to as full clone of @from - @to must not contain any nodes */
298 int dccp_feat_clone_list(struct list_head
const *from
, struct list_head
*to
)
300 struct dccp_feat_entry
*entry
, *new;
303 list_for_each_entry(entry
, from
, node
) {
304 new = dccp_feat_clone_entry(entry
);
307 list_add_tail(&new->node
, to
);
312 dccp_feat_list_purge(to
);
317 * dccp_feat_valid_nn_length - Enforce length constraints on NN options
318 * Length is between 0 and %DCCP_OPTVAL_MAXLEN. Used for outgoing packets only,
319 * incoming options are accepted as long as their values are valid.
321 static u8
dccp_feat_valid_nn_length(u8 feat_num
)
323 if (feat_num
== DCCPF_ACK_RATIO
) /* RFC 4340, 11.3 and 6.6.8 */
325 if (feat_num
== DCCPF_SEQUENCE_WINDOW
) /* RFC 4340, 7.5.2 and 6.5 */
330 static u8
dccp_feat_is_valid_nn_val(u8 feat_num
, u64 val
)
333 case DCCPF_ACK_RATIO
:
334 return val
<= DCCPF_ACK_RATIO_MAX
;
335 case DCCPF_SEQUENCE_WINDOW
:
336 return val
>= DCCPF_SEQ_WMIN
&& val
<= DCCPF_SEQ_WMAX
;
338 return 0; /* feature unknown - so we can't tell */
341 /* check that SP values are within the ranges defined in RFC 4340 */
342 static u8
dccp_feat_is_valid_sp_val(u8 feat_num
, u8 val
)
346 return val
== DCCPC_CCID2
|| val
== DCCPC_CCID3
;
347 /* Type-check Boolean feature values: */
348 case DCCPF_SHORT_SEQNOS
:
349 case DCCPF_ECN_INCAPABLE
:
350 case DCCPF_SEND_ACK_VECTOR
:
351 case DCCPF_SEND_NDP_COUNT
:
352 case DCCPF_DATA_CHECKSUM
:
353 case DCCPF_SEND_LEV_RATE
:
355 case DCCPF_MIN_CSUM_COVER
:
358 return 0; /* feature unknown */
361 static u8
dccp_feat_sp_list_ok(u8 feat_num
, u8
const *sp_list
, u8 sp_len
)
363 if (sp_list
== NULL
|| sp_len
< 1)
366 if (!dccp_feat_is_valid_sp_val(feat_num
, *sp_list
++))
372 * dccp_feat_insert_opts - Generate FN options from current list state
373 * @skb: next sk_buff to be sent to the peer
374 * @dp: for client during handshake and general negotiation
375 * @dreq: used by the server only (all Changes/Confirms in LISTEN/RESPOND)
377 int dccp_feat_insert_opts(struct dccp_sock
*dp
, struct dccp_request_sock
*dreq
,
380 struct list_head
*fn
= dreq
? &dreq
->dreq_featneg
: &dp
->dccps_featneg
;
381 struct dccp_feat_entry
*pos
, *next
;
382 u8 opt
, type
, len
, *ptr
, nn_in_nbo
[DCCP_OPTVAL_MAXLEN
];
385 /* put entries into @skb in the order they appear in the list */
386 list_for_each_entry_safe_reverse(pos
, next
, fn
, node
) {
387 opt
= dccp_feat_genopt(pos
);
388 type
= dccp_feat_type(pos
->feat_num
);
391 if (pos
->empty_confirm
) {
395 if (type
== FEAT_SP
) {
396 len
= pos
->val
.sp
.len
;
397 ptr
= pos
->val
.sp
.vec
;
398 rpt
= pos
->needs_confirm
;
399 } else if (type
== FEAT_NN
) {
400 len
= dccp_feat_valid_nn_length(pos
->feat_num
);
402 dccp_encode_value_var(pos
->val
.nn
, ptr
, len
);
404 DCCP_BUG("unknown feature %u", pos
->feat_num
);
409 if (dccp_insert_fn_opt(skb
, opt
, pos
->feat_num
, ptr
, len
, rpt
))
411 if (pos
->needs_mandatory
&& dccp_insert_option_mandatory(skb
))
414 * Enter CHANGING after transmitting the Change option (6.6.2).
416 if (pos
->state
== FEAT_INITIALISING
)
417 pos
->state
= FEAT_CHANGING
;
423 * __feat_register_nn - Register new NN value on socket
424 * @fn: feature-negotiation list to register with
425 * @feat: an NN feature from %dccp_feature_numbers
426 * @mandatory: use Mandatory option if 1
427 * @nn_val: value to register (restricted to 4 bytes)
428 * Note that NN features are local by definition (RFC 4340, 6.3.2).
430 static int __feat_register_nn(struct list_head
*fn
, u8 feat
,
431 u8 mandatory
, u64 nn_val
)
433 dccp_feat_val fval
= { .nn
= nn_val
};
435 if (dccp_feat_type(feat
) != FEAT_NN
||
436 !dccp_feat_is_valid_nn_val(feat
, nn_val
))
439 /* Don't bother with default values, they will be activated anyway. */
440 if (nn_val
- (u64
)dccp_feat_default_value(feat
) == 0)
443 return dccp_feat_push_change(fn
, feat
, 1, mandatory
, &fval
);
447 * __feat_register_sp - Register new SP value/list on socket
448 * @fn: feature-negotiation list to register with
449 * @feat: an SP feature from %dccp_feature_numbers
450 * @is_local: whether the local (1) or the remote (0) @feat is meant
451 * @mandatory: use Mandatory option if 1
452 * @sp_val: SP value followed by optional preference list
453 * @sp_len: length of @sp_val in bytes
455 static int __feat_register_sp(struct list_head
*fn
, u8 feat
, u8 is_local
,
456 u8 mandatory
, u8
const *sp_val
, u8 sp_len
)
460 if (dccp_feat_type(feat
) != FEAT_SP
||
461 !dccp_feat_sp_list_ok(feat
, sp_val
, sp_len
))
464 /* Avoid negotiating alien CCIDs by only advertising supported ones */
465 if (feat
== DCCPF_CCID
&& !ccid_support_check(sp_val
, sp_len
))
468 if (dccp_feat_clone_sp_val(&fval
, sp_val
, sp_len
))
471 return dccp_feat_push_change(fn
, feat
, is_local
, mandatory
, &fval
);
475 * dccp_feat_register_sp - Register requests to change SP feature values
476 * @sk: client or listening socket
477 * @feat: one of %dccp_feature_numbers
478 * @is_local: whether the local (1) or remote (0) @feat is meant
479 * @list: array of preferred values, in descending order of preference
480 * @len: length of @list in bytes
482 int dccp_feat_register_sp(struct sock
*sk
, u8 feat
, u8 is_local
,
483 u8
const *list
, u8 len
)
484 { /* any changes must be registered before establishing the connection */
485 if (sk
->sk_state
!= DCCP_CLOSED
)
487 if (dccp_feat_type(feat
) != FEAT_SP
)
489 return __feat_register_sp(&dccp_sk(sk
)->dccps_featneg
, feat
, is_local
,
493 /* Analogous to dccp_feat_register_sp(), but for non-negotiable values */
494 int dccp_feat_register_nn(struct sock
*sk
, u8 feat
, u64 val
)
496 /* any changes must be registered before establishing the connection */
497 if (sk
->sk_state
!= DCCP_CLOSED
)
499 if (dccp_feat_type(feat
) != FEAT_NN
)
501 return __feat_register_nn(&dccp_sk(sk
)->dccps_featneg
, feat
, 0, val
);
505 * Tracking features whose value depend on the choice of CCID
507 * This is designed with an extension in mind so that a list walk could be done
508 * before activating any features. However, the existing framework was found to
509 * work satisfactorily up until now, the automatic verification is left open.
510 * When adding new CCIDs, add a corresponding dependency table here.
512 static const struct ccid_dependency
*dccp_feat_ccid_deps(u8 ccid
, bool is_local
)
514 static const struct ccid_dependency ccid2_dependencies
[2][2] = {
516 * CCID2 mandates Ack Vectors (RFC 4341, 4.): as CCID is a TX
517 * feature and Send Ack Vector is an RX feature, `is_local'
518 * needs to be reversed.
520 { /* Dependencies of the receiver-side (remote) CCID2 */
522 .dependent_feat
= DCCPF_SEND_ACK_VECTOR
,
524 .is_mandatory
= true,
529 { /* Dependencies of the sender-side (local) CCID2 */
531 .dependent_feat
= DCCPF_SEND_ACK_VECTOR
,
533 .is_mandatory
= true,
539 static const struct ccid_dependency ccid3_dependencies
[2][5] = {
541 * Dependencies of the receiver-side CCID3
543 { /* locally disable Ack Vectors */
544 .dependent_feat
= DCCPF_SEND_ACK_VECTOR
,
546 .is_mandatory
= false,
549 { /* see below why Send Loss Event Rate is on */
550 .dependent_feat
= DCCPF_SEND_LEV_RATE
,
552 .is_mandatory
= true,
555 { /* NDP Count is needed as per RFC 4342, 6.1.1 */
556 .dependent_feat
= DCCPF_SEND_NDP_COUNT
,
558 .is_mandatory
= true,
564 * CCID3 at the TX side: we request that the HC-receiver
565 * will not send Ack Vectors (they will be ignored, so
566 * Mandatory is not set); we enable Send Loss Event Rate
567 * (Mandatory since the implementation does not support
568 * the Loss Intervals option of RFC 4342, 8.6).
569 * The last two options are for peer's information only.
572 .dependent_feat
= DCCPF_SEND_ACK_VECTOR
,
574 .is_mandatory
= false,
578 .dependent_feat
= DCCPF_SEND_LEV_RATE
,
580 .is_mandatory
= true,
583 { /* this CCID does not support Ack Ratio */
584 .dependent_feat
= DCCPF_ACK_RATIO
,
586 .is_mandatory
= false,
589 { /* tell receiver we are sending NDP counts */
590 .dependent_feat
= DCCPF_SEND_NDP_COUNT
,
592 .is_mandatory
= false,
600 return ccid2_dependencies
[is_local
];
602 return ccid3_dependencies
[is_local
];
609 * dccp_feat_propagate_ccid - Resolve dependencies of features on choice of CCID
610 * @fn: feature-negotiation list to update
611 * @id: CCID number to track
612 * @is_local: whether TX CCID (1) or RX CCID (0) is meant
613 * This function needs to be called after registering all other features.
615 static int dccp_feat_propagate_ccid(struct list_head
*fn
, u8 id
, bool is_local
)
617 const struct ccid_dependency
*table
= dccp_feat_ccid_deps(id
, is_local
);
618 int i
, rc
= (table
== NULL
);
620 for (i
= 0; rc
== 0 && table
[i
].dependent_feat
!= DCCPF_RESERVED
; i
++)
621 if (dccp_feat_type(table
[i
].dependent_feat
) == FEAT_SP
)
622 rc
= __feat_register_sp(fn
, table
[i
].dependent_feat
,
624 table
[i
].is_mandatory
,
627 rc
= __feat_register_nn(fn
, table
[i
].dependent_feat
,
628 table
[i
].is_mandatory
,
634 * dccp_feat_finalise_settings - Finalise settings before starting negotiation
635 * @dp: client or listening socket (settings will be inherited)
636 * This is called after all registrations (socket initialisation, sysctls, and
637 * sockopt calls), and before sending the first packet containing Change options
638 * (ie. client-Request or server-Response), to ensure internal consistency.
640 int dccp_feat_finalise_settings(struct dccp_sock
*dp
)
642 struct list_head
*fn
= &dp
->dccps_featneg
;
643 struct dccp_feat_entry
*entry
;
644 int i
= 2, ccids
[2] = { -1, -1 };
648 * 1) not useful to propagate CCID settings if this host advertises more
649 * than one CCID: the choice of CCID may still change - if this is
650 * the client, or if this is the server and the client sends
651 * singleton CCID values.
652 * 2) since is that propagate_ccid changes the list, we defer changing
653 * the sorted list until after the traversal.
655 list_for_each_entry(entry
, fn
, node
)
656 if (entry
->feat_num
== DCCPF_CCID
&& entry
->val
.sp
.len
== 1)
657 ccids
[entry
->is_local
] = entry
->val
.sp
.vec
[0];
659 if (ccids
[i
] > 0 && dccp_feat_propagate_ccid(fn
, ccids
[i
], i
))
665 * dccp_feat_server_ccid_dependencies - Resolve CCID-dependent features
666 * It is the server which resolves the dependencies once the CCID has been
667 * fully negotiated. If no CCID has been negotiated, it uses the default CCID.
669 int dccp_feat_server_ccid_dependencies(struct dccp_request_sock
*dreq
)
671 struct list_head
*fn
= &dreq
->dreq_featneg
;
672 struct dccp_feat_entry
*entry
;
675 for (is_local
= 0; is_local
<= 1; is_local
++) {
676 entry
= dccp_feat_list_lookup(fn
, DCCPF_CCID
, is_local
);
678 if (entry
!= NULL
&& !entry
->empty_confirm
)
679 ccid
= entry
->val
.sp
.vec
[0];
681 ccid
= dccp_feat_default_value(DCCPF_CCID
);
683 if (dccp_feat_propagate_ccid(fn
, ccid
, is_local
))
689 static int dccp_feat_update_ccid(struct sock
*sk
, u8 type
, u8 new_ccid_nr
)
691 struct dccp_sock
*dp
= dccp_sk(sk
);
692 struct dccp_minisock
*dmsk
= dccp_msk(sk
);
693 /* figure out if we are changing our CCID or the peer's */
694 const int rx
= type
== DCCPO_CHANGE_R
;
695 const u8 ccid_nr
= rx
? dmsk
->dccpms_rx_ccid
: dmsk
->dccpms_tx_ccid
;
696 struct ccid
*new_ccid
;
698 /* Check if nothing is being changed. */
699 if (ccid_nr
== new_ccid_nr
)
702 new_ccid
= ccid_new(new_ccid_nr
, sk
, rx
, GFP_ATOMIC
);
703 if (new_ccid
== NULL
)
707 ccid_hc_rx_delete(dp
->dccps_hc_rx_ccid
, sk
);
708 dp
->dccps_hc_rx_ccid
= new_ccid
;
709 dmsk
->dccpms_rx_ccid
= new_ccid_nr
;
711 ccid_hc_tx_delete(dp
->dccps_hc_tx_ccid
, sk
);
712 dp
->dccps_hc_tx_ccid
= new_ccid
;
713 dmsk
->dccpms_tx_ccid
= new_ccid_nr
;
719 static int dccp_feat_update(struct sock
*sk
, u8 type
, u8 feat
, u8 val
)
721 dccp_feat_debug(type
, feat
, val
);
725 return dccp_feat_update_ccid(sk
, type
, val
);
727 dccp_pr_debug("UNIMPLEMENTED: %s(%d, ...)\n",
728 dccp_feat_typename(type
), feat
);
734 /* Select the first entry in @servlist that also occurs in @clilist (6.3.1) */
735 static int dccp_feat_preflist_match(u8
*servlist
, u8 slen
, u8
*clilist
, u8 clen
)
739 for (s
= 0; s
< slen
; s
++)
740 for (c
= 0; c
< clen
; c
++)
741 if (servlist
[s
] == clilist
[c
])
747 * dccp_feat_prefer - Move preferred entry to the start of array
748 * Reorder the @array_len elements in @array so that @preferred_value comes
749 * first. Returns >0 to indicate that @preferred_value does occur in @array.
751 static u8
dccp_feat_prefer(u8 preferred_value
, u8
*array
, u8 array_len
)
753 u8 i
, does_occur
= 0;
756 for (i
= 0; i
< array_len
; i
++)
757 if (array
[i
] == preferred_value
) {
762 array
[0] = preferred_value
;
768 * dccp_feat_reconcile - Reconcile SP preference lists
769 * @fval: SP list to reconcile into
770 * @arr: received SP preference list
771 * @len: length of @arr in bytes
772 * @is_server: whether this side is the server (and @fv is the server's list)
773 * @reorder: whether to reorder the list in @fv after reconciling with @arr
774 * When successful, > 0 is returned and the reconciled list is in @fval.
775 * A value of 0 means that negotiation failed (no shared entry).
777 static int dccp_feat_reconcile(dccp_feat_val
*fv
, u8
*arr
, u8 len
,
778 bool is_server
, bool reorder
)
782 if (!fv
->sp
.vec
|| !arr
) {
783 DCCP_CRIT("NULL feature value or array");
788 rc
= dccp_feat_preflist_match(fv
->sp
.vec
, fv
->sp
.len
, arr
, len
);
790 rc
= dccp_feat_preflist_match(arr
, len
, fv
->sp
.vec
, fv
->sp
.len
);
798 * Reorder list: used for activating features and in dccp_insert_fn_opt.
800 return dccp_feat_prefer(rc
, fv
->sp
.vec
, fv
->sp
.len
);
803 #ifdef __this_is_the_old_framework_and_will_be_removed_later_in_a_subsequent_patch
804 static int dccp_feat_reconcile(struct sock
*sk
, struct dccp_opt_pend
*opt
,
807 struct dccp_sock
*dp
= dccp_sk(sk
);
808 u8
*spref
, slen
, *res
= NULL
;
809 int i
, j
, rc
, agree
= 1;
811 BUG_ON(rpref
== NULL
);
813 /* check if we are the black sheep */
814 if (dp
->dccps_role
== DCCP_ROLE_CLIENT
) {
817 rpref
= opt
->dccpop_val
;
818 rlen
= opt
->dccpop_len
;
820 spref
= opt
->dccpop_val
;
821 slen
= opt
->dccpop_len
;
824 * Now we have server preference list in spref and client preference in
827 BUG_ON(spref
== NULL
);
828 BUG_ON(rpref
== NULL
);
830 /* FIXME sanity check vals */
832 /* Are values in any order? XXX Lame "algorithm" here */
833 for (i
= 0; i
< slen
; i
++) {
834 for (j
= 0; j
< rlen
; j
++) {
835 if (spref
[i
] == rpref
[j
]) {
844 /* we didn't agree on anything */
846 /* confirm previous value */
847 switch (opt
->dccpop_feat
) {
849 /* XXX did i get this right? =P */
850 if (opt
->dccpop_type
== DCCPO_CHANGE_L
)
851 res
= &dccp_msk(sk
)->dccpms_tx_ccid
;
853 res
= &dccp_msk(sk
)->dccpms_rx_ccid
;
857 DCCP_BUG("Fell through, feat=%d", opt
->dccpop_feat
);
858 /* XXX implement res */
862 dccp_pr_debug("Don't agree... reconfirming %d\n", *res
);
863 agree
= 0; /* this is used for mandatory options... */
866 /* need to put result and our preference list */
867 rlen
= 1 + opt
->dccpop_len
;
868 rpref
= kmalloc(rlen
, GFP_ATOMIC
);
873 memcpy(&rpref
[1], opt
->dccpop_val
, opt
->dccpop_len
);
875 /* put it in the "confirm queue" */
876 if (opt
->dccpop_sc
== NULL
) {
877 opt
->dccpop_sc
= kmalloc(sizeof(*opt
->dccpop_sc
), GFP_ATOMIC
);
878 if (opt
->dccpop_sc
== NULL
) {
883 /* recycle the confirm slot */
884 BUG_ON(opt
->dccpop_sc
->dccpoc_val
== NULL
);
885 kfree(opt
->dccpop_sc
->dccpoc_val
);
886 dccp_pr_debug("recycling confirm slot\n");
888 memset(opt
->dccpop_sc
, 0, sizeof(*opt
->dccpop_sc
));
890 opt
->dccpop_sc
->dccpoc_val
= rpref
;
891 opt
->dccpop_sc
->dccpoc_len
= rlen
;
893 /* update the option on our side [we are about to send the confirm] */
894 rc
= dccp_feat_update(sk
, opt
->dccpop_type
, opt
->dccpop_feat
, *res
);
896 kfree(opt
->dccpop_sc
->dccpoc_val
);
897 kfree(opt
->dccpop_sc
);
898 opt
->dccpop_sc
= NULL
;
902 dccp_pr_debug("Will confirm %d\n", *rpref
);
904 /* say we want to change to X but we just got a confirm X, suppress our
907 if (!opt
->dccpop_conf
) {
908 if (*opt
->dccpop_val
== *res
)
909 opt
->dccpop_conf
= 1;
910 dccp_pr_debug("won't ask for change of same feature\n");
913 return agree
? 0 : DCCP_FEAT_SP_NOAGREE
; /* used for mandatory opts */
916 static int dccp_feat_sp(struct sock
*sk
, u8 type
, u8 feature
, u8
*val
, u8 len
)
918 struct dccp_minisock
*dmsk
= dccp_msk(sk
);
919 struct dccp_opt_pend
*opt
;
924 * We received a CHANGE. We gotta match it against our own preference
925 * list. If we got a CHANGE_R it means it's a change for us, so we need
926 * to compare our CHANGE_L list.
928 if (type
== DCCPO_CHANGE_L
)
933 /* find our preference list for this feature */
934 list_for_each_entry(opt
, &dmsk
->dccpms_pending
, dccpop_node
) {
935 if (opt
->dccpop_type
!= t
|| opt
->dccpop_feat
!= feature
)
938 /* find the winner from the two preference lists */
939 rc
= dccp_feat_reconcile(sk
, opt
, val
, len
);
943 /* We didn't deal with the change. This can happen if we have no
944 * preference list for the feature. In fact, it just shouldn't
945 * happen---if we understand a feature, we should have a preference list
946 * with at least the default value.
953 static int dccp_feat_nn(struct sock
*sk
, u8 type
, u8 feature
, u8
*val
, u8 len
)
955 struct dccp_opt_pend
*opt
;
956 struct dccp_minisock
*dmsk
= dccp_msk(sk
);
960 /* NN features must be Change L (sec. 6.3.2) */
961 if (type
!= DCCPO_CHANGE_L
) {
962 dccp_pr_debug("received %s for NN feature %d\n",
963 dccp_feat_typename(type
), feature
);
967 /* XXX sanity check opt val */
969 /* copy option so we can confirm it */
970 opt
= kzalloc(sizeof(*opt
), GFP_ATOMIC
);
974 copy
= kmemdup(val
, len
, GFP_ATOMIC
);
980 opt
->dccpop_type
= DCCPO_CONFIRM_R
; /* NN can only confirm R */
981 opt
->dccpop_feat
= feature
;
982 opt
->dccpop_val
= copy
;
983 opt
->dccpop_len
= len
;
986 rc
= dccp_feat_update(sk
, type
, feature
, *val
);
988 kfree(opt
->dccpop_val
);
993 dccp_feat_debug(type
, feature
, *copy
);
995 list_add_tail(&opt
->dccpop_node
, &dmsk
->dccpms_conf
);
1000 static void dccp_feat_empty_confirm(struct dccp_minisock
*dmsk
,
1001 u8 type
, u8 feature
)
1003 /* XXX check if other confirms for that are queued and recycle slot */
1004 struct dccp_opt_pend
*opt
= kzalloc(sizeof(*opt
), GFP_ATOMIC
);
1007 /* XXX what do we do? Ignoring should be fine. It's a change
1014 case DCCPO_CHANGE_L
:
1015 opt
->dccpop_type
= DCCPO_CONFIRM_R
;
1017 case DCCPO_CHANGE_R
:
1018 opt
->dccpop_type
= DCCPO_CONFIRM_L
;
1021 DCCP_WARN("invalid type %d\n", type
);
1025 opt
->dccpop_feat
= feature
;
1026 opt
->dccpop_val
= NULL
;
1027 opt
->dccpop_len
= 0;
1029 /* change feature */
1030 dccp_pr_debug("Empty %s(%d)\n", dccp_feat_typename(type
), feature
);
1032 list_add_tail(&opt
->dccpop_node
, &dmsk
->dccpms_conf
);
1035 static void dccp_feat_flush_confirm(struct sock
*sk
)
1037 struct dccp_minisock
*dmsk
= dccp_msk(sk
);
1038 /* Check if there is anything to confirm in the first place */
1039 int yes
= !list_empty(&dmsk
->dccpms_conf
);
1042 struct dccp_opt_pend
*opt
;
1044 list_for_each_entry(opt
, &dmsk
->dccpms_pending
, dccpop_node
) {
1045 if (opt
->dccpop_conf
) {
1055 /* OK there is something to confirm... */
1056 /* XXX check if packet is in flight? Send delayed ack?? */
1057 if (sk
->sk_state
== DCCP_OPEN
)
1061 int dccp_feat_change_recv(struct sock
*sk
, u8 type
, u8 feature
, u8
*val
, u8 len
)
1065 /* Ignore Change requests other than during connection setup */
1066 if (sk
->sk_state
!= DCCP_LISTEN
&& sk
->sk_state
!= DCCP_REQUESTING
)
1068 dccp_feat_debug(type
, feature
, *val
);
1070 /* figure out if it's SP or NN feature */
1072 /* deal with SP features */
1074 /* XXX Obsoleted by next patch
1075 rc = dccp_feat_sp(sk, type, feature, val, len); */
1078 /* deal with NN features */
1079 case DCCPF_ACK_RATIO
:
1080 /* XXX Obsoleted by next patch
1081 rc = dccp_feat_nn(sk, type, feature, val, len); */
1084 /* XXX implement other features */
1086 dccp_pr_debug("UNIMPLEMENTED: not handling %s(%d, ...)\n",
1087 dccp_feat_typename(type
), feature
);
1092 /* check if there were problems changing features */
1094 /* If we don't agree on SP, we sent a confirm for old value.
1095 * However we propagate rc to caller in case option was
1098 if (rc
!= DCCP_FEAT_SP_NOAGREE
)
1099 dccp_feat_empty_confirm(dccp_msk(sk
), type
, feature
);
1102 /* generate the confirm [if required] */
1103 dccp_feat_flush_confirm(sk
);
1108 EXPORT_SYMBOL_GPL(dccp_feat_change_recv
);
1110 int dccp_feat_confirm_recv(struct sock
*sk
, u8 type
, u8 feature
,
1114 struct dccp_opt_pend
*opt
;
1115 struct dccp_minisock
*dmsk
= dccp_msk(sk
);
1117 int all_confirmed
= 1;
1119 /* Ignore Confirm options other than during connection setup */
1120 if (sk
->sk_state
!= DCCP_LISTEN
&& sk
->sk_state
!= DCCP_REQUESTING
)
1122 dccp_feat_debug(type
, feature
, *val
);
1124 /* locate our change request */
1126 case DCCPO_CONFIRM_L
: t
= DCCPO_CHANGE_R
; break;
1127 case DCCPO_CONFIRM_R
: t
= DCCPO_CHANGE_L
; break;
1128 default: DCCP_WARN("invalid type %d\n", type
);
1132 /* XXX sanity check feature value */
1134 list_for_each_entry(opt
, &dmsk
->dccpms_pending
, dccpop_node
) {
1135 if (!opt
->dccpop_conf
&& opt
->dccpop_type
== t
&&
1136 opt
->dccpop_feat
== feature
) {
1138 dccp_pr_debug("feature %d found\n", opt
->dccpop_feat
);
1140 /* XXX do sanity check */
1142 opt
->dccpop_conf
= 1;
1144 /* We got a confirmation---change the option */
1145 dccp_feat_update(sk
, opt
->dccpop_type
,
1146 opt
->dccpop_feat
, *val
);
1148 /* XXX check the return value of dccp_feat_update */
1152 if (!opt
->dccpop_conf
)
1157 dccp_pr_debug("%s(%d, ...) never requested\n",
1158 dccp_feat_typename(type
), feature
);
1162 EXPORT_SYMBOL_GPL(dccp_feat_confirm_recv
);
1163 #endif /* (later) */
1165 void dccp_feat_clean(struct dccp_minisock
*dmsk
)
1167 struct dccp_opt_pend
*opt
, *next
;
1169 list_for_each_entry_safe(opt
, next
, &dmsk
->dccpms_pending
,
1171 BUG_ON(opt
->dccpop_val
== NULL
);
1172 kfree(opt
->dccpop_val
);
1174 if (opt
->dccpop_sc
!= NULL
) {
1175 BUG_ON(opt
->dccpop_sc
->dccpoc_val
== NULL
);
1176 kfree(opt
->dccpop_sc
->dccpoc_val
);
1177 kfree(opt
->dccpop_sc
);
1182 INIT_LIST_HEAD(&dmsk
->dccpms_pending
);
1184 list_for_each_entry_safe(opt
, next
, &dmsk
->dccpms_conf
, dccpop_node
) {
1185 BUG_ON(opt
== NULL
);
1186 if (opt
->dccpop_val
!= NULL
)
1187 kfree(opt
->dccpop_val
);
1190 INIT_LIST_HEAD(&dmsk
->dccpms_conf
);
1193 EXPORT_SYMBOL_GPL(dccp_feat_clean
);
1195 /* this is to be called only when a listening sock creates its child. It is
1196 * assumed by the function---the confirm is not duplicated, but rather it is
1199 int dccp_feat_clone(struct sock
*oldsk
, struct sock
*newsk
)
1201 struct dccp_minisock
*olddmsk
= dccp_msk(oldsk
);
1202 struct dccp_minisock
*newdmsk
= dccp_msk(newsk
);
1203 struct dccp_opt_pend
*opt
;
1206 INIT_LIST_HEAD(&newdmsk
->dccpms_pending
);
1207 INIT_LIST_HEAD(&newdmsk
->dccpms_conf
);
1209 list_for_each_entry(opt
, &olddmsk
->dccpms_pending
, dccpop_node
) {
1210 struct dccp_opt_pend
*newopt
;
1211 /* copy the value of the option */
1212 u8
*val
= kmemdup(opt
->dccpop_val
, opt
->dccpop_len
, GFP_ATOMIC
);
1217 newopt
= kmemdup(opt
, sizeof(*newopt
), GFP_ATOMIC
);
1218 if (newopt
== NULL
) {
1223 /* insert the option */
1224 newopt
->dccpop_val
= val
;
1225 list_add_tail(&newopt
->dccpop_node
, &newdmsk
->dccpms_pending
);
1227 /* XXX what happens with backlogs and multiple connections at
1230 /* the master socket no longer needs to worry about confirms */
1231 opt
->dccpop_sc
= NULL
; /* it's not a memleak---new socket has it */
1233 /* reset state for a new socket */
1234 opt
->dccpop_conf
= 0;
1237 /* XXX not doing anything about the conf queue */
1243 dccp_feat_clean(newdmsk
);
1248 EXPORT_SYMBOL_GPL(dccp_feat_clone
);
1251 * dccp_feat_change_recv - Process incoming ChangeL/R options
1252 * @fn: feature-negotiation list to update
1253 * @is_mandatory: whether the Change was preceded by a Mandatory option
1254 * @opt: %DCCPO_CHANGE_L or %DCCPO_CHANGE_R
1255 * @feat: one of %dccp_feature_numbers
1256 * @val: NN value or SP value/preference list
1257 * @len: length of @val in bytes
1258 * @server: whether this node is the server (1) or the client (0)
1260 static u8
dccp_feat_change_recv(struct list_head
*fn
, u8 is_mandatory
, u8 opt
,
1261 u8 feat
, u8
*val
, u8 len
, const bool server
)
1263 u8 defval
, type
= dccp_feat_type(feat
);
1264 const bool local
= (opt
== DCCPO_CHANGE_R
);
1265 struct dccp_feat_entry
*entry
;
1268 if (len
== 0 || type
== FEAT_UNKNOWN
) /* 6.1 and 6.6.8 */
1269 goto unknown_feature_or_value
;
1272 * Negotiation of NN features: Change R is invalid, so there is no
1273 * simultaneous negotiation; hence we do not look up in the list.
1275 if (type
== FEAT_NN
) {
1276 if (local
|| len
> sizeof(fval
.nn
))
1277 goto unknown_feature_or_value
;
1279 /* 6.3.2: "The feature remote MUST accept any valid value..." */
1280 fval
.nn
= dccp_decode_value_var(val
, len
);
1281 if (!dccp_feat_is_valid_nn_val(feat
, fval
.nn
))
1282 goto unknown_feature_or_value
;
1284 return dccp_feat_push_confirm(fn
, feat
, local
, &fval
);
1288 * Unidirectional/simultaneous negotiation of SP features (6.3.1)
1290 entry
= dccp_feat_list_lookup(fn
, feat
, local
);
1291 if (entry
== NULL
) {
1293 * No particular preferences have been registered. We deal with
1294 * this situation by assuming that all valid values are equally
1295 * acceptable, and apply the following checks:
1296 * - if the peer's list is a singleton, we accept a valid value;
1297 * - if we are the server, we first try to see if the peer (the
1298 * client) advertises the default value. If yes, we use it,
1299 * otherwise we accept the preferred value;
1300 * - else if we are the client, we use the first list element.
1302 if (dccp_feat_clone_sp_val(&fval
, val
, 1))
1303 return DCCP_RESET_CODE_TOO_BUSY
;
1305 if (len
> 1 && server
) {
1306 defval
= dccp_feat_default_value(feat
);
1307 if (dccp_feat_preflist_match(&defval
, 1, val
, len
) > -1)
1308 fval
.sp
.vec
[0] = defval
;
1309 } else if (!dccp_feat_is_valid_sp_val(feat
, fval
.sp
.vec
[0])) {
1311 goto unknown_feature_or_value
;
1314 /* Treat unsupported CCIDs like invalid values */
1315 if (feat
== DCCPF_CCID
&& !ccid_support_check(fval
.sp
.vec
, 1)) {
1317 goto not_valid_or_not_known
;
1320 return dccp_feat_push_confirm(fn
, feat
, local
, &fval
);
1322 } else if (entry
->state
== FEAT_UNSTABLE
) { /* 6.6.2 */
1326 if (dccp_feat_reconcile(&entry
->val
, val
, len
, server
, true)) {
1327 entry
->empty_confirm
= 0;
1328 } else if (is_mandatory
) {
1329 return DCCP_RESET_CODE_MANDATORY_ERROR
;
1330 } else if (entry
->state
== FEAT_INITIALISING
) {
1332 * Failed simultaneous negotiation (server only): try to `save'
1333 * the connection by checking whether entry contains the default
1334 * value for @feat. If yes, send an empty Confirm to signal that
1335 * the received Change was not understood - which implies using
1336 * the default value.
1337 * If this also fails, we use Reset as the last resort.
1340 defval
= dccp_feat_default_value(feat
);
1341 if (!dccp_feat_reconcile(&entry
->val
, &defval
, 1, server
, true))
1342 return DCCP_RESET_CODE_OPTION_ERROR
;
1343 entry
->empty_confirm
= 1;
1345 entry
->needs_confirm
= 1;
1346 entry
->needs_mandatory
= 0;
1347 entry
->state
= FEAT_STABLE
;
1350 unknown_feature_or_value
:
1352 return dccp_push_empty_confirm(fn
, feat
, local
);
1354 not_valid_or_not_known
:
1355 return is_mandatory
? DCCP_RESET_CODE_MANDATORY_ERROR
1356 : DCCP_RESET_CODE_OPTION_ERROR
;
1360 * dccp_feat_confirm_recv - Process received Confirm options
1361 * @fn: feature-negotiation list to update
1362 * @is_mandatory: whether @opt was preceded by a Mandatory option
1363 * @opt: %DCCPO_CONFIRM_L or %DCCPO_CONFIRM_R
1364 * @feat: one of %dccp_feature_numbers
1365 * @val: NN value or SP value/preference list
1366 * @len: length of @val in bytes
1367 * @server: whether this node is server (1) or client (0)
1369 static u8
dccp_feat_confirm_recv(struct list_head
*fn
, u8 is_mandatory
, u8 opt
,
1370 u8 feat
, u8
*val
, u8 len
, const bool server
)
1372 u8
*plist
, plen
, type
= dccp_feat_type(feat
);
1373 const bool local
= (opt
== DCCPO_CONFIRM_R
);
1374 struct dccp_feat_entry
*entry
= dccp_feat_list_lookup(fn
, feat
, local
);
1376 if (entry
== NULL
) { /* nothing queued: ignore or handle error */
1377 if (is_mandatory
&& type
== FEAT_UNKNOWN
)
1378 return DCCP_RESET_CODE_MANDATORY_ERROR
;
1380 if (!local
&& type
== FEAT_NN
) /* 6.3.2 */
1381 goto confirmation_failed
;
1385 if (entry
->state
!= FEAT_CHANGING
) /* 6.6.2 */
1389 if (dccp_feat_must_be_understood(feat
)) /* 6.6.7 */
1390 goto confirmation_failed
;
1392 * Empty Confirm during connection setup: this means reverting
1393 * to the `old' value, which in this case is the default. Since
1394 * we handle default values automatically when no other values
1395 * have been set, we revert to the old value by removing this
1396 * entry from the list.
1398 dccp_feat_list_pop(entry
);
1402 if (type
== FEAT_NN
) {
1403 if (len
> sizeof(entry
->val
.nn
))
1404 goto confirmation_failed
;
1406 if (entry
->val
.nn
== dccp_decode_value_var(val
, len
))
1407 goto confirmation_succeeded
;
1409 DCCP_WARN("Bogus Confirm for non-existing value\n");
1410 goto confirmation_failed
;
1414 * Parsing SP Confirms: the first element of @val is the preferred
1415 * SP value which the peer confirms, the remainder depends on @len.
1416 * Note that only the confirmed value need to be a valid SP value.
1418 if (!dccp_feat_is_valid_sp_val(feat
, *val
))
1419 goto confirmation_failed
;
1421 if (len
== 1) { /* peer didn't supply a preference list */
1424 } else { /* preferred value + preference list */
1429 /* Check whether the peer got the reconciliation right (6.6.8) */
1430 if (dccp_feat_reconcile(&entry
->val
, plist
, plen
, server
, 0) != *val
) {
1431 DCCP_WARN("Confirm selected the wrong value %u\n", *val
);
1432 return DCCP_RESET_CODE_OPTION_ERROR
;
1434 entry
->val
.sp
.vec
[0] = *val
;
1436 confirmation_succeeded
:
1437 entry
->state
= FEAT_STABLE
;
1440 confirmation_failed
:
1441 DCCP_WARN("Confirmation failed\n");
1442 return is_mandatory
? DCCP_RESET_CODE_MANDATORY_ERROR
1443 : DCCP_RESET_CODE_OPTION_ERROR
;
1447 * dccp_feat_parse_options - Process Feature-Negotiation Options
1448 * @sk: for general use and used by the client during connection setup
1449 * @dreq: used by the server during connection setup
1450 * @mandatory: whether @opt was preceded by a Mandatory option
1451 * @opt: %DCCPO_CHANGE_L | %DCCPO_CHANGE_R | %DCCPO_CONFIRM_L | %DCCPO_CONFIRM_R
1452 * @feat: one of %dccp_feature_numbers
1453 * @val: value contents of @opt
1454 * @len: length of @val in bytes
1455 * Returns 0 on success, a Reset code for ending the connection otherwise.
1457 int dccp_feat_parse_options(struct sock
*sk
, struct dccp_request_sock
*dreq
,
1458 u8 mandatory
, u8 opt
, u8 feat
, u8
*val
, u8 len
)
1460 struct dccp_sock
*dp
= dccp_sk(sk
);
1461 struct list_head
*fn
= dreq
? &dreq
->dreq_featneg
: &dp
->dccps_featneg
;
1462 bool server
= false;
1464 switch (sk
->sk_state
) {
1466 * Negotiation during connection setup
1469 server
= true; /* fall through */
1470 case DCCP_REQUESTING
:
1472 case DCCPO_CHANGE_L
:
1473 case DCCPO_CHANGE_R
:
1474 return dccp_feat_change_recv(fn
, mandatory
, opt
, feat
,
1476 case DCCPO_CONFIRM_R
:
1477 case DCCPO_CONFIRM_L
:
1478 return dccp_feat_confirm_recv(fn
, mandatory
, opt
, feat
,
1482 return 0; /* ignore FN options in all other states */
1485 int dccp_feat_init(struct sock
*sk
)
1487 struct dccp_sock
*dp
= dccp_sk(sk
);
1488 struct dccp_minisock
*dmsk
= dccp_msk(sk
);
1491 INIT_LIST_HEAD(&dmsk
->dccpms_pending
); /* XXX no longer used */
1492 INIT_LIST_HEAD(&dmsk
->dccpms_conf
); /* XXX no longer used */
1495 rc
= __feat_register_sp(&dp
->dccps_featneg
, DCCPF_CCID
, 1, 0,
1496 &dmsk
->dccpms_tx_ccid
, 1);
1501 rc
= __feat_register_sp(&dp
->dccps_featneg
, DCCPF_CCID
, 0, 0,
1502 &dmsk
->dccpms_rx_ccid
, 1);
1507 rc
= __feat_register_nn(&dp
->dccps_featneg
, DCCPF_ACK_RATIO
, 0,
1508 dp
->dccps_l_ack_ratio
);
1513 EXPORT_SYMBOL_GPL(dccp_feat_init
);
1515 #ifdef CONFIG_IP_DCCP_DEBUG
1516 const char *dccp_feat_typename(const u8 type
)
1519 case DCCPO_CHANGE_L
: return("ChangeL");
1520 case DCCPO_CONFIRM_L
: return("ConfirmL");
1521 case DCCPO_CHANGE_R
: return("ChangeR");
1522 case DCCPO_CONFIRM_R
: return("ConfirmR");
1523 /* the following case must not appear in feature negotation */
1524 default: dccp_pr_debug("unknown type %d [BUG!]\n", type
);
1529 EXPORT_SYMBOL_GPL(dccp_feat_typename
);
1531 const char *dccp_feat_name(const u8 feat
)
1533 static const char *feature_names
[] = {
1534 [DCCPF_RESERVED
] = "Reserved",
1535 [DCCPF_CCID
] = "CCID",
1536 [DCCPF_SHORT_SEQNOS
] = "Allow Short Seqnos",
1537 [DCCPF_SEQUENCE_WINDOW
] = "Sequence Window",
1538 [DCCPF_ECN_INCAPABLE
] = "ECN Incapable",
1539 [DCCPF_ACK_RATIO
] = "Ack Ratio",
1540 [DCCPF_SEND_ACK_VECTOR
] = "Send ACK Vector",
1541 [DCCPF_SEND_NDP_COUNT
] = "Send NDP Count",
1542 [DCCPF_MIN_CSUM_COVER
] = "Min. Csum Coverage",
1543 [DCCPF_DATA_CHECKSUM
] = "Send Data Checksum",
1545 if (feat
> DCCPF_DATA_CHECKSUM
&& feat
< DCCPF_MIN_CCID_SPECIFIC
)
1546 return feature_names
[DCCPF_RESERVED
];
1548 if (feat
== DCCPF_SEND_LEV_RATE
)
1549 return "Send Loss Event Rate";
1550 if (feat
>= DCCPF_MIN_CCID_SPECIFIC
)
1551 return "CCID-specific";
1553 return feature_names
[feat
];
1556 EXPORT_SYMBOL_GPL(dccp_feat_name
);
1557 #endif /* CONFIG_IP_DCCP_DEBUG */