net/dccp/feat.c

   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  *  ASSUMPTIONS
   8  *  -----------
   9  *  o All currently known SP features have 1-byte quantities. If in the future
  10  *    extensions of RFCs 4340..42 define features with item lengths larger than
  11  *    one byte, a feature-specific extension of the code will be required.
  12  *
  13  *  This program is free software; you can redistribute it and/or
  14  *  modify it under the terms of the GNU General Public License
  15  *  as published by the Free Software Foundation; either version
  16  *  2 of the License, or (at your option) any later version.
  17  */
  18
  19 #include <linux/module.h>
  20
  21 #include "ccid.h"
  22 #include "feat.h"
  23
  24 #define DCCP_FEAT_SP_NOAGREE (-123)
  25
  26 static const struct {
  27         u8                      feat_num;               /* DCCPF_xxx */
  28         enum dccp_feat_type     rxtx;                   /* RX or TX  */
  29         enum dccp_feat_type     reconciliation;         /* SP or NN  */
  30         u8                      default_value;          /* as in 6.4 */
  31 /*
  32  *    Lookup table for location and type of features (from RFC 4340/4342)
  33  *  +--------------------------+----+-----+----+----+---------+-----------+
  34  *  | Feature                  | Location | Reconc. | Initial |  Section  |
  35  *  |                          | RX | TX  | SP | NN |  Value  | Reference |
  36  *  +--------------------------+----+-----+----+----+---------+-----------+
  37  *  | DCCPF_CCID               |    |  X  | X  |    |   2     | 10        |
  38  *  | DCCPF_SHORT_SEQNOS       |    |  X  | X  |    |   0     |  7.6.1    |
  39  *  | DCCPF_SEQUENCE_WINDOW    |    |  X  |    | X  | 100     |  7.5.2    |
  40  *  | DCCPF_ECN_INCAPABLE      | X  |     | X  |    |   0     | 12.1      |
  41  *  | DCCPF_ACK_RATIO          |    |  X  |    | X  |   2     | 11.3      |
  42  *  | DCCPF_SEND_ACK_VECTOR    | X  |     | X  |    |   0     | 11.5      |
  43  *  | DCCPF_SEND_NDP_COUNT     |    |  X  | X  |    |   0     |  7.7.2    |
  44  *  | DCCPF_MIN_CSUM_COVER     | X  |     | X  |    |   0     |  9.2.1    |
  45  *  | DCCPF_DATA_CHECKSUM      | X  |     | X  |    |   0     |  9.3.1    |
  46  *  | DCCPF_SEND_LEV_RATE      | X  |     | X  |    |   0     | 4342/8.4  |
  47  *  +--------------------------+----+-----+----+----+---------+-----------+
  48  */
  49 } dccp_feat_table[] = {
  50         { DCCPF_CCID,            FEAT_AT_TX, FEAT_SP, 2 },
  51         { DCCPF_SHORT_SEQNOS,    FEAT_AT_TX, FEAT_SP, 0 },
  52         { DCCPF_SEQUENCE_WINDOW, FEAT_AT_TX, FEAT_NN, 100 },
  53         { DCCPF_ECN_INCAPABLE,   FEAT_AT_RX, FEAT_SP, 0 },
  54         { DCCPF_ACK_RATIO,       FEAT_AT_TX, FEAT_NN, 2 },
  55         { DCCPF_SEND_ACK_VECTOR, FEAT_AT_RX, FEAT_SP, 0 },
  56         { DCCPF_SEND_NDP_COUNT,  FEAT_AT_TX, FEAT_SP, 0 },
  57         { DCCPF_MIN_CSUM_COVER,  FEAT_AT_RX, FEAT_SP, 0 },
  58         { DCCPF_DATA_CHECKSUM,   FEAT_AT_RX, FEAT_SP, 0 },
  59         { DCCPF_SEND_LEV_RATE,   FEAT_AT_RX, FEAT_SP, 0 },
  60 };
  61 #define DCCP_FEAT_SUPPORTED_MAX         ARRAY_SIZE(dccp_feat_table)
  62
  63 /**
  64  * dccp_feat_index  -  Hash function to map feature number into array position
  65  * Returns consecutive array index or -1 if the feature is not understood.
  66  */
  67 static int dccp_feat_index(u8 feat_num)
  68 {
  69         /* The first 9 entries are occupied by the types from RFC 4340, 6.4 */
  70         if (feat_num > DCCPF_RESERVED && feat_num <= DCCPF_DATA_CHECKSUM)
  71                 return feat_num - 1;
  72
  73         /*
  74          * Other features: add cases for new feature types here after adding
  75          * them to the above table.
  76          */
  77         switch (feat_num) {
  78         case DCCPF_SEND_LEV_RATE:
  79                         return DCCP_FEAT_SUPPORTED_MAX - 1;
  80         }
  81         return -1;
  82 }
  83
  84 static u8 dccp_feat_type(u8 feat_num)
  85 {
  86         int idx = dccp_feat_index(feat_num);
  87
  88         if (idx < 0)
  89                 return FEAT_UNKNOWN;
  90         return dccp_feat_table[idx].reconciliation;
  91 }
  92
  93 /* copy constructor, fval must not already contain allocated memory */
  94 static int dccp_feat_clone_sp_val(dccp_feat_val *fval, u8 const *val, u8 len)
  95 {
  96         fval->sp.len = len;
  97         if (fval->sp.len > 0) {
  98                 fval->sp.vec = kmemdup(val, len, gfp_any());
  99                 if (fval->sp.vec == NULL) {
 100                         fval->sp.len = 0;
 101                         return -ENOBUFS;
 102                 }
 103         }
 104         return 0;
 105 }
 106
 107 static void dccp_feat_val_destructor(u8 feat_num, dccp_feat_val *val)
 108 {
 109         if (unlikely(val == NULL))
 110                 return;
 111         if (dccp_feat_type(feat_num) == FEAT_SP)
 112                 kfree(val->sp.vec);
 113         memset(val, 0, sizeof(*val));
 114 }
 115
 116 static struct dccp_feat_entry *
 117               dccp_feat_clone_entry(struct dccp_feat_entry const *original)
 118 {
 119         struct dccp_feat_entry *new;
 120         u8 type = dccp_feat_type(original->feat_num);
 121
 122         if (type == FEAT_UNKNOWN)
 123                 return NULL;
 124
 125         new = kmemdup(original, sizeof(struct dccp_feat_entry), gfp_any());
 126         if (new == NULL)
 127                 return NULL;
 128
 129         if (type == FEAT_SP && dccp_feat_clone_sp_val(&new->val,
 130                                                       original->val.sp.vec,
 131                                                       original->val.sp.len)) {
 132                 kfree(new);
 133                 return NULL;
 134         }
 135         return new;
 136 }
 137
 138 static void dccp_feat_entry_destructor(struct dccp_feat_entry *entry)
 139 {
 140         if (entry != NULL) {
 141                 dccp_feat_val_destructor(entry->feat_num, &entry->val);
 142                 kfree(entry);
 143         }
 144 }
 145
 146 /*
 147  * List management functions
 148  *
 149  * Feature negotiation lists rely on and maintain the following invariants:
 150  * - each feat_num in the list is known, i.e. we know its type and default value
 151  * - each feat_num/is_local combination is unique (old entries are overwritten)
 152  * - SP values are always freshly allocated
 153  * - list is sorted in increasing order of feature number (faster lookup)
 154  */
 155
 156 static inline void dccp_feat_list_pop(struct dccp_feat_entry *entry)
 157 {
 158         list_del(&entry->node);
 159         dccp_feat_entry_destructor(entry);
 160 }
 161
 162 void dccp_feat_list_purge(struct list_head *fn_list)
 163 {
 164         struct dccp_feat_entry *entry, *next;
 165
 166         list_for_each_entry_safe(entry, next, fn_list, node)
 167                 dccp_feat_entry_destructor(entry);
 168         INIT_LIST_HEAD(fn_list);
 169 }
 170 EXPORT_SYMBOL_GPL(dccp_feat_list_purge);
 171
 172 /* generate @to as full clone of @from - @to must not contain any nodes */
 173 int dccp_feat_clone_list(struct list_head const *from, struct list_head *to)
 174 {
 175         struct dccp_feat_entry *entry, *new;
 176
 177         INIT_LIST_HEAD(to);
 178         list_for_each_entry(entry, from, node) {
 179                 new = dccp_feat_clone_entry(entry);
 180                 if (new == NULL)
 181                         goto cloning_failed;
 182                 list_add_tail(&new->node, to);
 183         }
 184         return 0;
 185
 186 cloning_failed:
 187         dccp_feat_list_purge(to);
 188         return -ENOMEM;
 189 }
 190
 191 int dccp_feat_change(struct dccp_minisock *dmsk, u8 type, u8 feature,
 192                      u8 *val, u8 len, gfp_t gfp)
 193 {
 194         struct dccp_opt_pend *opt;
 195
 196         dccp_feat_debug(type, feature, *val);
 197
 198         if (len > 3) {
 199                 DCCP_WARN("invalid length %d\n", len);
 200                 return -EINVAL;
 201         }
 202         /* XXX add further sanity checks */
 203
 204         /* check if that feature is already being negotiated */
 205         list_for_each_entry(opt, &dmsk->dccpms_pending, dccpop_node) {
 206                 /* ok we found a negotiation for this option already */
 207                 if (opt->dccpop_feat == feature && opt->dccpop_type == type) {
 208                         dccp_pr_debug("Replacing old\n");
 209                         /* replace */
 210                         BUG_ON(opt->dccpop_val == NULL);
 211                         kfree(opt->dccpop_val);
 212                         opt->dccpop_val  = val;
 213                         opt->dccpop_len  = len;
 214                         opt->dccpop_conf = 0;
 215                         return 0;
 216                 }
 217         }
 218
 219         /* negotiation for a new feature */
 220         opt = kmalloc(sizeof(*opt), gfp);
 221         if (opt == NULL)
 222                 return -ENOMEM;
 223
 224         opt->dccpop_type = type;
 225         opt->dccpop_feat = feature;
 226         opt->dccpop_len  = len;
 227         opt->dccpop_val  = val;
 228         opt->dccpop_conf = 0;
 229         opt->dccpop_sc   = NULL;
 230
 231         BUG_ON(opt->dccpop_val == NULL);
 232
 233         list_add_tail(&opt->dccpop_node, &dmsk->dccpms_pending);
 234         return 0;
 235 }
 236
 237 EXPORT_SYMBOL_GPL(dccp_feat_change);
 238
 239 static int dccp_feat_update_ccid(struct sock *sk, u8 type, u8 new_ccid_nr)
 240 {
 241         struct dccp_sock *dp = dccp_sk(sk);
 242         struct dccp_minisock *dmsk = dccp_msk(sk);
 243         /* figure out if we are changing our CCID or the peer's */
 244         const int rx = type == DCCPO_CHANGE_R;
 245         const u8 ccid_nr = rx ? dmsk->dccpms_rx_ccid : dmsk->dccpms_tx_ccid;
 246         struct ccid *new_ccid;
 247
 248         /* Check if nothing is being changed. */
 249         if (ccid_nr == new_ccid_nr)
 250                 return 0;
 251
 252         new_ccid = ccid_new(new_ccid_nr, sk, rx, GFP_ATOMIC);
 253         if (new_ccid == NULL)
 254                 return -ENOMEM;
 255
 256         if (rx) {
 257                 ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk);
 258                 dp->dccps_hc_rx_ccid = new_ccid;
 259                 dmsk->dccpms_rx_ccid = new_ccid_nr;
 260         } else {
 261                 ccid_hc_tx_delete(dp->dccps_hc_tx_ccid, sk);
 262                 dp->dccps_hc_tx_ccid = new_ccid;
 263                 dmsk->dccpms_tx_ccid = new_ccid_nr;
 264         }
 265
 266         return 0;
 267 }
 268
 269 static int dccp_feat_update(struct sock *sk, u8 type, u8 feat, u8 val)
 270 {
 271         dccp_feat_debug(type, feat, val);
 272
 273         switch (feat) {
 274         case DCCPF_CCID:
 275                 return dccp_feat_update_ccid(sk, type, val);
 276         default:
 277                 dccp_pr_debug("UNIMPLEMENTED: %s(%d, ...)\n",
 278                               dccp_feat_typename(type), feat);
 279                 break;
 280         }
 281         return 0;
 282 }
 283
 284 static int dccp_feat_reconcile(struct sock *sk, struct dccp_opt_pend *opt,
 285                                u8 *rpref, u8 rlen)
 286 {
 287         struct dccp_sock *dp = dccp_sk(sk);
 288         u8 *spref, slen, *res = NULL;
 289         int i, j, rc, agree = 1;
 290
 291         BUG_ON(rpref == NULL);
 292
 293         /* check if we are the black sheep */
 294         if (dp->dccps_role == DCCP_ROLE_CLIENT) {
 295                 spref = rpref;
 296                 slen  = rlen;
 297                 rpref = opt->dccpop_val;
 298                 rlen  = opt->dccpop_len;
 299         } else {
 300                 spref = opt->dccpop_val;
 301                 slen  = opt->dccpop_len;
 302         }
 303         /*
 304          * Now we have server preference list in spref and client preference in
 305          * rpref
 306          */
 307         BUG_ON(spref == NULL);
 308         BUG_ON(rpref == NULL);
 309
 310         /* FIXME sanity check vals */
 311
 312         /* Are values in any order?  XXX Lame "algorithm" here */
 313         for (i = 0; i < slen; i++) {
 314                 for (j = 0; j < rlen; j++) {
 315                         if (spref[i] == rpref[j]) {
 316                                 res = &spref[i];
 317                                 break;
 318                         }
 319                 }
 320                 if (res)
 321                         break;
 322         }
 323
 324         /* we didn't agree on anything */
 325         if (res == NULL) {
 326                 /* confirm previous value */
 327                 switch (opt->dccpop_feat) {
 328                 case DCCPF_CCID:
 329                         /* XXX did i get this right? =P */
 330                         if (opt->dccpop_type == DCCPO_CHANGE_L)
 331                                 res = &dccp_msk(sk)->dccpms_tx_ccid;
 332                         else
 333                                 res = &dccp_msk(sk)->dccpms_rx_ccid;
 334                         break;
 335
 336                 default:
 337                         DCCP_BUG("Fell through, feat=%d", opt->dccpop_feat);
 338                         /* XXX implement res */
 339                         return -EFAULT;
 340                 }
 341
 342                 dccp_pr_debug("Don't agree... reconfirming %d\n", *res);
 343                 agree = 0; /* this is used for mandatory options... */
 344         }
 345
 346         /* need to put result and our preference list */
 347         rlen = 1 + opt->dccpop_len;
 348         rpref = kmalloc(rlen, GFP_ATOMIC);
 349         if (rpref == NULL)
 350                 return -ENOMEM;
 351
 352         *rpref = *res;
 353         memcpy(&rpref[1], opt->dccpop_val, opt->dccpop_len);
 354
 355         /* put it in the "confirm queue" */
 356         if (opt->dccpop_sc == NULL) {
 357                 opt->dccpop_sc = kmalloc(sizeof(*opt->dccpop_sc), GFP_ATOMIC);
 358                 if (opt->dccpop_sc == NULL) {
 359                         kfree(rpref);
 360                         return -ENOMEM;
 361                 }
 362         } else {
 363                 /* recycle the confirm slot */
 364                 BUG_ON(opt->dccpop_sc->dccpoc_val == NULL);
 365                 kfree(opt->dccpop_sc->dccpoc_val);
 366                 dccp_pr_debug("recycling confirm slot\n");
 367         }
 368         memset(opt->dccpop_sc, 0, sizeof(*opt->dccpop_sc));
 369
 370         opt->dccpop_sc->dccpoc_val = rpref;
 371         opt->dccpop_sc->dccpoc_len = rlen;
 372
 373         /* update the option on our side [we are about to send the confirm] */
 374         rc = dccp_feat_update(sk, opt->dccpop_type, opt->dccpop_feat, *res);
 375         if (rc) {
 376                 kfree(opt->dccpop_sc->dccpoc_val);
 377                 kfree(opt->dccpop_sc);
 378                 opt->dccpop_sc = NULL;
 379                 return rc;
 380         }
 381
 382         dccp_pr_debug("Will confirm %d\n", *rpref);
 383
 384         /* say we want to change to X but we just got a confirm X, suppress our
 385          * change
 386          */
 387         if (!opt->dccpop_conf) {
 388                 if (*opt->dccpop_val == *res)
 389                         opt->dccpop_conf = 1;
 390                 dccp_pr_debug("won't ask for change of same feature\n");
 391         }
 392
 393         return agree ? 0 : DCCP_FEAT_SP_NOAGREE; /* used for mandatory opts */
 394 }
 395
 396 static int dccp_feat_sp(struct sock *sk, u8 type, u8 feature, u8 *val, u8 len)
 397 {
 398         struct dccp_minisock *dmsk = dccp_msk(sk);
 399         struct dccp_opt_pend *opt;
 400         int rc = 1;
 401         u8 t;
 402
 403         /*
 404          * We received a CHANGE.  We gotta match it against our own preference
 405          * list.  If we got a CHANGE_R it means it's a change for us, so we need
 406          * to compare our CHANGE_L list.
 407          */
 408         if (type == DCCPO_CHANGE_L)
 409                 t = DCCPO_CHANGE_R;
 410         else
 411                 t = DCCPO_CHANGE_L;
 412
 413         /* find our preference list for this feature */
 414         list_for_each_entry(opt, &dmsk->dccpms_pending, dccpop_node) {
 415                 if (opt->dccpop_type != t || opt->dccpop_feat != feature)
 416                         continue;
 417
 418                 /* find the winner from the two preference lists */
 419                 rc = dccp_feat_reconcile(sk, opt, val, len);
 420                 break;
 421         }
 422
 423         /* We didn't deal with the change.  This can happen if we have no
 424          * preference list for the feature.  In fact, it just shouldn't
 425          * happen---if we understand a feature, we should have a preference list
 426          * with at least the default value.
 427          */
 428         BUG_ON(rc == 1);
 429
 430         return rc;
 431 }
 432
 433 static int dccp_feat_nn(struct sock *sk, u8 type, u8 feature, u8 *val, u8 len)
 434 {
 435         struct dccp_opt_pend *opt;
 436         struct dccp_minisock *dmsk = dccp_msk(sk);
 437         u8 *copy;
 438         int rc;
 439
 440         /* NN features must be Change L (sec. 6.3.2) */
 441         if (type != DCCPO_CHANGE_L) {
 442                 dccp_pr_debug("received %s for NN feature %d\n",
 443                                 dccp_feat_typename(type), feature);
 444                 return -EFAULT;
 445         }
 446
 447         /* XXX sanity check opt val */
 448
 449         /* copy option so we can confirm it */
 450         opt = kzalloc(sizeof(*opt), GFP_ATOMIC);
 451         if (opt == NULL)
 452                 return -ENOMEM;
 453
 454         copy = kmemdup(val, len, GFP_ATOMIC);
 455         if (copy == NULL) {
 456                 kfree(opt);
 457                 return -ENOMEM;
 458         }
 459
 460         opt->dccpop_type = DCCPO_CONFIRM_R; /* NN can only confirm R */
 461         opt->dccpop_feat = feature;
 462         opt->dccpop_val  = copy;
 463         opt->dccpop_len  = len;
 464
 465         /* change feature */
 466         rc = dccp_feat_update(sk, type, feature, *val);
 467         if (rc) {
 468                 kfree(opt->dccpop_val);
 469                 kfree(opt);
 470                 return rc;
 471         }
 472
 473         dccp_feat_debug(type, feature, *copy);
 474
 475         list_add_tail(&opt->dccpop_node, &dmsk->dccpms_conf);
 476
 477         return 0;
 478 }
 479
 480 static void dccp_feat_empty_confirm(struct dccp_minisock *dmsk,
 481                                     u8 type, u8 feature)
 482 {
 483         /* XXX check if other confirms for that are queued and recycle slot */
 484         struct dccp_opt_pend *opt = kzalloc(sizeof(*opt), GFP_ATOMIC);
 485
 486         if (opt == NULL) {
 487                 /* XXX what do we do?  Ignoring should be fine.  It's a change
 488                  * after all =P
 489                  */
 490                 return;
 491         }
 492
 493         switch (type) {
 494         case DCCPO_CHANGE_L:
 495                 opt->dccpop_type = DCCPO_CONFIRM_R;
 496                 break;
 497         case DCCPO_CHANGE_R:
 498                 opt->dccpop_type = DCCPO_CONFIRM_L;
 499                 break;
 500         default:
 501                 DCCP_WARN("invalid type %d\n", type);
 502                 kfree(opt);
 503                 return;
 504         }
 505         opt->dccpop_feat = feature;
 506         opt->dccpop_val  = NULL;
 507         opt->dccpop_len  = 0;
 508
 509         /* change feature */
 510         dccp_pr_debug("Empty %s(%d)\n", dccp_feat_typename(type), feature);
 511
 512         list_add_tail(&opt->dccpop_node, &dmsk->dccpms_conf);
 513 }
 514
 515 static void dccp_feat_flush_confirm(struct sock *sk)
 516 {
 517         struct dccp_minisock *dmsk = dccp_msk(sk);
 518         /* Check if there is anything to confirm in the first place */
 519         int yes = !list_empty(&dmsk->dccpms_conf);
 520
 521         if (!yes) {
 522                 struct dccp_opt_pend *opt;
 523
 524                 list_for_each_entry(opt, &dmsk->dccpms_pending, dccpop_node) {
 525                         if (opt->dccpop_conf) {
 526                                 yes = 1;
 527                                 break;
 528                         }
 529                 }
 530         }
 531
 532         if (!yes)
 533                 return;
 534
 535         /* OK there is something to confirm... */
 536         /* XXX check if packet is in flight?  Send delayed ack?? */
 537         if (sk->sk_state == DCCP_OPEN)
 538                 dccp_send_ack(sk);
 539 }
 540
 541 int dccp_feat_change_recv(struct sock *sk, u8 type, u8 feature, u8 *val, u8 len)
 542 {
 543         int rc;
 544
 545         dccp_feat_debug(type, feature, *val);
 546
 547         /* figure out if it's SP or NN feature */
 548         switch (feature) {
 549         /* deal with SP features */
 550         case DCCPF_CCID:
 551                 rc = dccp_feat_sp(sk, type, feature, val, len);
 552                 break;
 553
 554         /* deal with NN features */
 555         case DCCPF_ACK_RATIO:
 556                 rc = dccp_feat_nn(sk, type, feature, val, len);
 557                 break;
 558
 559         /* XXX implement other features */
 560         default:
 561                 dccp_pr_debug("UNIMPLEMENTED: not handling %s(%d, ...)\n",
 562                               dccp_feat_typename(type), feature);
 563                 rc = -EFAULT;
 564                 break;
 565         }
 566
 567         /* check if there were problems changing features */
 568         if (rc) {
 569                 /* If we don't agree on SP, we sent a confirm for old value.
 570                  * However we propagate rc to caller in case option was
 571                  * mandatory
 572                  */
 573                 if (rc != DCCP_FEAT_SP_NOAGREE)
 574                         dccp_feat_empty_confirm(dccp_msk(sk), type, feature);
 575         }
 576
 577         /* generate the confirm [if required] */
 578         dccp_feat_flush_confirm(sk);
 579
 580         return rc;
 581 }
 582
 583 EXPORT_SYMBOL_GPL(dccp_feat_change_recv);
 584
 585 int dccp_feat_confirm_recv(struct sock *sk, u8 type, u8 feature,
 586                            u8 *val, u8 len)
 587 {
 588         u8 t;
 589         struct dccp_opt_pend *opt;
 590         struct dccp_minisock *dmsk = dccp_msk(sk);
 591         int found = 0;
 592         int all_confirmed = 1;
 593
 594         dccp_feat_debug(type, feature, *val);
 595
 596         /* locate our change request */
 597         switch (type) {
 598         case DCCPO_CONFIRM_L: t = DCCPO_CHANGE_R; break;
 599         case DCCPO_CONFIRM_R: t = DCCPO_CHANGE_L; break;
 600         default:              DCCP_WARN("invalid type %d\n", type);
 601                               return 1;
 602
 603         }
 604         /* XXX sanity check feature value */
 605
 606         list_for_each_entry(opt, &dmsk->dccpms_pending, dccpop_node) {
 607                 if (!opt->dccpop_conf && opt->dccpop_type == t &&
 608                     opt->dccpop_feat == feature) {
 609                         found = 1;
 610                         dccp_pr_debug("feature %d found\n", opt->dccpop_feat);
 611
 612                         /* XXX do sanity check */
 613
 614                         opt->dccpop_conf = 1;
 615
 616                         /* We got a confirmation---change the option */
 617                         dccp_feat_update(sk, opt->dccpop_type,
 618                                          opt->dccpop_feat, *val);
 619
 620                         /* XXX check the return value of dccp_feat_update */
 621                         break;
 622                 }
 623
 624                 if (!opt->dccpop_conf)
 625                         all_confirmed = 0;
 626         }
 627
 628         /* fix re-transmit timer */
 629         /* XXX gotta make sure that no option negotiation occurs during
 630          * connection shutdown.  Consider that the CLOSEREQ is sent and timer is
 631          * on.  if all options are confirmed it might kill timer which should
 632          * remain alive until close is received.
 633          */
 634         if (all_confirmed) {
 635                 dccp_pr_debug("clear feat negotiation timer %p\n", sk);
 636                 inet_csk_clear_xmit_timer(sk, ICSK_TIME_RETRANS);
 637         }
 638
 639         if (!found)
 640                 dccp_pr_debug("%s(%d, ...) never requested\n",
 641                               dccp_feat_typename(type), feature);
 642         return 0;
 643 }
 644
 645 EXPORT_SYMBOL_GPL(dccp_feat_confirm_recv);
 646
 647 void dccp_feat_clean(struct dccp_minisock *dmsk)
 648 {
 649         struct dccp_opt_pend *opt, *next;
 650
 651         list_for_each_entry_safe(opt, next, &dmsk->dccpms_pending,
 652                                  dccpop_node) {
 653                 BUG_ON(opt->dccpop_val == NULL);
 654                 kfree(opt->dccpop_val);
 655
 656                 if (opt->dccpop_sc != NULL) {
 657                         BUG_ON(opt->dccpop_sc->dccpoc_val == NULL);
 658                         kfree(opt->dccpop_sc->dccpoc_val);
 659                         kfree(opt->dccpop_sc);
 660                 }
 661
 662                 kfree(opt);
 663         }
 664         INIT_LIST_HEAD(&dmsk->dccpms_pending);
 665
 666         list_for_each_entry_safe(opt, next, &dmsk->dccpms_conf, dccpop_node) {
 667                 BUG_ON(opt == NULL);
 668                 if (opt->dccpop_val != NULL)
 669                         kfree(opt->dccpop_val);
 670                 kfree(opt);
 671         }
 672         INIT_LIST_HEAD(&dmsk->dccpms_conf);
 673 }
 674
 675 EXPORT_SYMBOL_GPL(dccp_feat_clean);
 676
 677 /* this is to be called only when a listening sock creates its child.  It is
 678  * assumed by the function---the confirm is not duplicated, but rather it is
 679  * "passed on".
 680  */
 681 int dccp_feat_clone(struct sock *oldsk, struct sock *newsk)
 682 {
 683         struct dccp_minisock *olddmsk = dccp_msk(oldsk);
 684         struct dccp_minisock *newdmsk = dccp_msk(newsk);
 685         struct dccp_opt_pend *opt;
 686         int rc = 0;
 687
 688         INIT_LIST_HEAD(&newdmsk->dccpms_pending);
 689         INIT_LIST_HEAD(&newdmsk->dccpms_conf);
 690
 691         list_for_each_entry(opt, &olddmsk->dccpms_pending, dccpop_node) {
 692                 struct dccp_opt_pend *newopt;
 693                 /* copy the value of the option */
 694                 u8 *val = kmemdup(opt->dccpop_val, opt->dccpop_len, GFP_ATOMIC);
 695
 696                 if (val == NULL)
 697                         goto out_clean;
 698
 699                 newopt = kmemdup(opt, sizeof(*newopt), GFP_ATOMIC);
 700                 if (newopt == NULL) {
 701                         kfree(val);
 702                         goto out_clean;
 703                 }
 704
 705                 /* insert the option */
 706                 newopt->dccpop_val = val;
 707                 list_add_tail(&newopt->dccpop_node, &newdmsk->dccpms_pending);
 708
 709                 /* XXX what happens with backlogs and multiple connections at
 710                  * once...
 711                  */
 712                 /* the master socket no longer needs to worry about confirms */
 713                 opt->dccpop_sc = NULL; /* it's not a memleak---new socket has it */
 714
 715                 /* reset state for a new socket */
 716                 opt->dccpop_conf = 0;
 717         }
 718
 719         /* XXX not doing anything about the conf queue */
 720
 721 out:
 722         return rc;
 723
 724 out_clean:
 725         dccp_feat_clean(newdmsk);
 726         rc = -ENOMEM;
 727         goto out;
 728 }
 729
 730 EXPORT_SYMBOL_GPL(dccp_feat_clone);
 731
 732 static int __dccp_feat_init(struct dccp_minisock *dmsk, u8 type, u8 feat,
 733                             u8 *val, u8 len)
 734 {
 735         int rc = -ENOMEM;
 736         u8 *copy = kmemdup(val, len, GFP_KERNEL);
 737
 738         if (copy != NULL) {
 739                 rc = dccp_feat_change(dmsk, type, feat, copy, len, GFP_KERNEL);
 740                 if (rc)
 741                         kfree(copy);
 742         }
 743         return rc;
 744 }
 745
 746 int dccp_feat_init(struct dccp_minisock *dmsk)
 747 {
 748         int rc;
 749
 750         INIT_LIST_HEAD(&dmsk->dccpms_pending);
 751         INIT_LIST_HEAD(&dmsk->dccpms_conf);
 752
 753         /* CCID L */
 754         rc = __dccp_feat_init(dmsk, DCCPO_CHANGE_L, DCCPF_CCID,
 755                               &dmsk->dccpms_tx_ccid, 1);
 756         if (rc)
 757                 goto out;
 758
 759         /* CCID R */
 760         rc = __dccp_feat_init(dmsk, DCCPO_CHANGE_R, DCCPF_CCID,
 761                               &dmsk->dccpms_rx_ccid, 1);
 762         if (rc)
 763                 goto out;
 764
 765         /* Ack ratio */
 766         rc = __dccp_feat_init(dmsk, DCCPO_CHANGE_L, DCCPF_ACK_RATIO,
 767                               &dmsk->dccpms_ack_ratio, 1);
 768 out:
 769         return rc;
 770 }
 771
 772 EXPORT_SYMBOL_GPL(dccp_feat_init);
 773
 774 #ifdef CONFIG_IP_DCCP_DEBUG
 775 const char *dccp_feat_typename(const u8 type)
 776 {
 777         switch(type) {
 778         case DCCPO_CHANGE_L:  return("ChangeL");
 779         case DCCPO_CONFIRM_L: return("ConfirmL");
 780         case DCCPO_CHANGE_R:  return("ChangeR");
 781         case DCCPO_CONFIRM_R: return("ConfirmR");
 782         /* the following case must not appear in feature negotation  */
 783         default:              dccp_pr_debug("unknown type %d [BUG!]\n", type);
 784         }
 785         return NULL;
 786 }
 787
 788 EXPORT_SYMBOL_GPL(dccp_feat_typename);
 789
 790 const char *dccp_feat_name(const u8 feat)
 791 {
 792         static const char *feature_names[] = {
 793                 [DCCPF_RESERVED]        = "Reserved",
 794                 [DCCPF_CCID]            = "CCID",
 795                 [DCCPF_SHORT_SEQNOS]    = "Allow Short Seqnos",
 796                 [DCCPF_SEQUENCE_WINDOW] = "Sequence Window",
 797                 [DCCPF_ECN_INCAPABLE]   = "ECN Incapable",
 798                 [DCCPF_ACK_RATIO]       = "Ack Ratio",
 799                 [DCCPF_SEND_ACK_VECTOR] = "Send ACK Vector",
 800                 [DCCPF_SEND_NDP_COUNT]  = "Send NDP Count",
 801                 [DCCPF_MIN_CSUM_COVER]  = "Min. Csum Coverage",
 802                 [DCCPF_DATA_CHECKSUM]   = "Send Data Checksum",
 803         };
 804         if (feat > DCCPF_DATA_CHECKSUM && feat < DCCPF_MIN_CCID_SPECIFIC)
 805                 return feature_names[DCCPF_RESERVED];
 806
 807         if (feat ==  DCCPF_SEND_LEV_RATE)
 808                 return "Send Loss Event Rate";
 809         if (feat >= DCCPF_MIN_CCID_SPECIFIC)
 810                 return "CCID-specific";
 811
 812         return feature_names[feat];
 813 }
 814
 815 EXPORT_SYMBOL_GPL(dccp_feat_name);
 816 #endif /* CONFIG_IP_DCCP_DEBUG */