net/tipc/msg.c

   1 /*
   2  * net/tipc/msg.c: TIPC message header routines
   3  *
   4  * Copyright (c) 2000-2006, 2014-2015, Ericsson AB
   5  * Copyright (c) 2005, 2010-2011, Wind River Systems
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions are met:
  10  *
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. Neither the names of the copyright holders nor the names of its
  17  *    contributors may be used to endorse or promote products derived from
  18  *    this software without specific prior written permission.
  19  *
  20  * Alternatively, this software may be distributed under the terms of the
  21  * GNU General Public License ("GPL") version 2 as published by the Free
  22  * Software Foundation.
  23  *
  24  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  25  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  27  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  28  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  29  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  30  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  31  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  32  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  33  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  34  * POSSIBILITY OF SUCH DAMAGE.
  35  */
  36
  37 #include <net/sock.h>
  38 #include "core.h"
  39 #include "msg.h"
  40 #include "addr.h"
  41 #include "name_table.h"
  42
  43 #define MAX_FORWARD_SIZE 1024
  44 #define BUF_HEADROOM (LL_MAX_HEADER + 48)
  45 #define BUF_TAILROOM 16
  46
  47 static unsigned int align(unsigned int i)
  48 {
  49         return (i + 3) & ~3u;
  50 }
  51
  52 /**
  53  * tipc_buf_acquire - creates a TIPC message buffer
  54  * @size: message size (including TIPC header)
  55  *
  56  * Returns a new buffer with data pointers set to the specified size.
  57  *
  58  * NOTE: Headroom is reserved to allow prepending of a data link header.
  59  *       There may also be unrequested tailroom present at the buffer's end.
  60  */
  61 struct sk_buff *tipc_buf_acquire(u32 size, gfp_t gfp)
  62 {
  63         struct sk_buff *skb;
  64         unsigned int buf_size = (BUF_HEADROOM + size + 3) & ~3u;
  65
  66         skb = alloc_skb_fclone(buf_size, gfp);
  67         if (skb) {
  68                 skb_reserve(skb, BUF_HEADROOM);
  69                 skb_put(skb, size);
  70                 skb->next = NULL;
  71         }
  72         return skb;
  73 }
  74
  75 void tipc_msg_init(u32 own_node, struct tipc_msg *m, u32 user, u32 type,
  76                    u32 hsize, u32 dnode)
  77 {
  78         memset(m, 0, hsize);
  79         msg_set_version(m);
  80         msg_set_user(m, user);
  81         msg_set_hdr_sz(m, hsize);
  82         msg_set_size(m, hsize);
  83         msg_set_prevnode(m, own_node);
  84         msg_set_type(m, type);
  85         if (hsize > SHORT_H_SIZE) {
  86                 msg_set_orignode(m, own_node);
  87                 msg_set_destnode(m, dnode);
  88         }
  89 }
  90
  91 struct sk_buff *tipc_msg_create(uint user, uint type,
  92                                 uint hdr_sz, uint data_sz, u32 dnode,
  93                                 u32 onode, u32 dport, u32 oport, int errcode)
  94 {
  95         struct tipc_msg *msg;
  96         struct sk_buff *buf;
  97
  98         buf = tipc_buf_acquire(hdr_sz + data_sz, GFP_ATOMIC);
  99         if (unlikely(!buf))
 100                 return NULL;
 101
 102         msg = buf_msg(buf);
 103         tipc_msg_init(onode, msg, user, type, hdr_sz, dnode);
 104         msg_set_size(msg, hdr_sz + data_sz);
 105         msg_set_origport(msg, oport);
 106         msg_set_destport(msg, dport);
 107         msg_set_errcode(msg, errcode);
 108         if (hdr_sz > SHORT_H_SIZE) {
 109                 msg_set_orignode(msg, onode);
 110                 msg_set_destnode(msg, dnode);
 111         }
 112         return buf;
 113 }
 114
 115 /* tipc_buf_append(): Append a buffer to the fragment list of another buffer
 116  * @*headbuf: in:  NULL for first frag, otherwise value returned from prev call
 117  *            out: set when successful non-complete reassembly, otherwise NULL
 118  * @*buf:     in:  the buffer to append. Always defined
 119  *            out: head buf after successful complete reassembly, otherwise NULL
 120  * Returns 1 when reassembly complete, otherwise 0
 121  */
 122 int tipc_buf_append(struct sk_buff **headbuf, struct sk_buff **buf)
 123 {
 124         struct sk_buff *head = *headbuf;
 125         struct sk_buff *frag = *buf;
 126         struct sk_buff *tail = NULL;
 127         struct tipc_msg *msg;
 128         u32 fragid;
 129         int delta;
 130         bool headstolen;
 131
 132         if (!frag)
 133                 goto err;
 134
 135         msg = buf_msg(frag);
 136         fragid = msg_type(msg);
 137         frag->next = NULL;
 138         skb_pull(frag, msg_hdr_sz(msg));
 139
 140         if (fragid == FIRST_FRAGMENT) {
 141                 if (unlikely(head))
 142                         goto err;
 143                 if (unlikely(skb_unclone(frag, GFP_ATOMIC)))
 144                         goto err;
 145                 head = *headbuf = frag;
 146                 *buf = NULL;
 147                 TIPC_SKB_CB(head)->tail = NULL;
 148                 if (skb_is_nonlinear(head)) {
 149                         skb_walk_frags(head, tail) {
 150                                 TIPC_SKB_CB(head)->tail = tail;
 151                         }
 152                 } else {
 153                         skb_frag_list_init(head);
 154                 }
 155                 return 0;
 156         }
 157
 158         if (!head)
 159                 goto err;
 160
 161         if (skb_try_coalesce(head, frag, &headstolen, &delta)) {
 162                 kfree_skb_partial(frag, headstolen);
 163         } else {
 164                 tail = TIPC_SKB_CB(head)->tail;
 165                 if (!skb_has_frag_list(head))
 166                         skb_shinfo(head)->frag_list = frag;
 167                 else
 168                         tail->next = frag;
 169                 head->truesize += frag->truesize;
 170                 head->data_len += frag->len;
 171                 head->len += frag->len;
 172                 TIPC_SKB_CB(head)->tail = frag;
 173         }
 174
 175         if (fragid == LAST_FRAGMENT) {
 176                 TIPC_SKB_CB(head)->validated = false;
 177                 if (unlikely(!tipc_msg_validate(head)))
 178                         goto err;
 179                 *buf = head;
 180                 TIPC_SKB_CB(head)->tail = NULL;
 181                 *headbuf = NULL;
 182                 return 1;
 183         }
 184         *buf = NULL;
 185         return 0;
 186 err:
 187         kfree_skb(*buf);
 188         kfree_skb(*headbuf);
 189         *buf = *headbuf = NULL;
 190         return 0;
 191 }
 192
 193 /* tipc_msg_validate - validate basic format of received message
 194  *
 195  * This routine ensures a TIPC message has an acceptable header, and at least
 196  * as much data as the header indicates it should.  The routine also ensures
 197  * that the entire message header is stored in the main fragment of the message
 198  * buffer, to simplify future access to message header fields.
 199  *
 200  * Note: Having extra info present in the message header or data areas is OK.
 201  * TIPC will ignore the excess, under the assumption that it is optional info
 202  * introduced by a later release of the protocol.
 203  */
 204 bool tipc_msg_validate(struct sk_buff *skb)
 205 {
 206         struct tipc_msg *msg;
 207         int msz, hsz;
 208
 209         if (unlikely(TIPC_SKB_CB(skb)->validated))
 210                 return true;
 211         if (unlikely(!pskb_may_pull(skb, MIN_H_SIZE)))
 212                 return false;
 213
 214         hsz = msg_hdr_sz(buf_msg(skb));
 215         if (unlikely(hsz < MIN_H_SIZE) || (hsz > MAX_H_SIZE))
 216                 return false;
 217         if (unlikely(!pskb_may_pull(skb, hsz)))
 218                 return false;
 219
 220         msg = buf_msg(skb);
 221         if (unlikely(msg_version(msg) != TIPC_VERSION))
 222                 return false;
 223
 224         msz = msg_size(msg);
 225         if (unlikely(msz < hsz))
 226                 return false;
 227         if (unlikely((msz - hsz) > TIPC_MAX_USER_MSG_SIZE))
 228                 return false;
 229         if (unlikely(skb->len < msz))
 230                 return false;
 231
 232         TIPC_SKB_CB(skb)->validated = true;
 233         return true;
 234 }
 235
 236 /**
 237  * tipc_msg_build - create buffer chain containing specified header and data
 238  * @mhdr: Message header, to be prepended to data
 239  * @m: User message
 240  * @dsz: Total length of user data
 241  * @pktmax: Max packet size that can be used
 242  * @list: Buffer or chain of buffers to be returned to caller
 243  *
 244  * Returns message data size or errno: -ENOMEM, -EFAULT
 245  */
 246 int tipc_msg_build(struct tipc_msg *mhdr, struct msghdr *m,
 247                    int offset, int dsz, int pktmax, struct sk_buff_head *list)
 248 {
 249         int mhsz = msg_hdr_sz(mhdr);
 250         int msz = mhsz + dsz;
 251         int pktno = 1;
 252         int pktsz;
 253         int pktrem = pktmax;
 254         int drem = dsz;
 255         struct tipc_msg pkthdr;
 256         struct sk_buff *skb;
 257         char *pktpos;
 258         int rc;
 259
 260         msg_set_size(mhdr, msz);
 261
 262         /* No fragmentation needed? */
 263         if (likely(msz <= pktmax)) {
 264                 skb = tipc_buf_acquire(msz, GFP_KERNEL);
 265                 if (unlikely(!skb))
 266                         return -ENOMEM;
 267                 skb_orphan(skb);
 268                 __skb_queue_tail(list, skb);
 269                 skb_copy_to_linear_data(skb, mhdr, mhsz);
 270                 pktpos = skb->data + mhsz;
 271                 if (copy_from_iter_full(pktpos, dsz, &m->msg_iter))
 272                         return dsz;
 273                 rc = -EFAULT;
 274                 goto error;
 275         }
 276
 277         /* Prepare reusable fragment header */
 278         tipc_msg_init(msg_prevnode(mhdr), &pkthdr, MSG_FRAGMENTER,
 279                       FIRST_FRAGMENT, INT_H_SIZE, msg_destnode(mhdr));
 280         msg_set_size(&pkthdr, pktmax);
 281         msg_set_fragm_no(&pkthdr, pktno);
 282         msg_set_importance(&pkthdr, msg_importance(mhdr));
 283
 284         /* Prepare first fragment */
 285         skb = tipc_buf_acquire(pktmax, GFP_KERNEL);
 286         if (!skb)
 287                 return -ENOMEM;
 288         skb_orphan(skb);
 289         __skb_queue_tail(list, skb);
 290         pktpos = skb->data;
 291         skb_copy_to_linear_data(skb, &pkthdr, INT_H_SIZE);
 292         pktpos += INT_H_SIZE;
 293         pktrem -= INT_H_SIZE;
 294         skb_copy_to_linear_data_offset(skb, INT_H_SIZE, mhdr, mhsz);
 295         pktpos += mhsz;
 296         pktrem -= mhsz;
 297
 298         do {
 299                 if (drem < pktrem)
 300                         pktrem = drem;
 301
 302                 if (!copy_from_iter_full(pktpos, pktrem, &m->msg_iter)) {
 303                         rc = -EFAULT;
 304                         goto error;
 305                 }
 306                 drem -= pktrem;
 307
 308                 if (!drem)
 309                         break;
 310
 311                 /* Prepare new fragment: */
 312                 if (drem < (pktmax - INT_H_SIZE))
 313                         pktsz = drem + INT_H_SIZE;
 314                 else
 315                         pktsz = pktmax;
 316                 skb = tipc_buf_acquire(pktsz, GFP_KERNEL);
 317                 if (!skb) {
 318                         rc = -ENOMEM;
 319                         goto error;
 320                 }
 321                 skb_orphan(skb);
 322                 __skb_queue_tail(list, skb);
 323                 msg_set_type(&pkthdr, FRAGMENT);
 324                 msg_set_size(&pkthdr, pktsz);
 325                 msg_set_fragm_no(&pkthdr, ++pktno);
 326                 skb_copy_to_linear_data(skb, &pkthdr, INT_H_SIZE);
 327                 pktpos = skb->data + INT_H_SIZE;
 328                 pktrem = pktsz - INT_H_SIZE;
 329
 330         } while (1);
 331         msg_set_type(buf_msg(skb), LAST_FRAGMENT);
 332         return dsz;
 333 error:
 334         __skb_queue_purge(list);
 335         __skb_queue_head_init(list);
 336         return rc;
 337 }
 338
 339 /**
 340  * tipc_msg_bundle(): Append contents of a buffer to tail of an existing one
 341  * @skb: the buffer to append to ("bundle")
 342  * @msg:  message to be appended
 343  * @mtu:  max allowable size for the bundle buffer
 344  * Consumes buffer if successful
 345  * Returns true if bundling could be performed, otherwise false
 346  */
 347 bool tipc_msg_bundle(struct sk_buff *skb, struct tipc_msg *msg, u32 mtu)
 348 {
 349         struct tipc_msg *bmsg;
 350         unsigned int bsz;
 351         unsigned int msz = msg_size(msg);
 352         u32 start, pad;
 353         u32 max = mtu - INT_H_SIZE;
 354
 355         if (likely(msg_user(msg) == MSG_FRAGMENTER))
 356                 return false;
 357         if (!skb)
 358                 return false;
 359         bmsg = buf_msg(skb);
 360         bsz = msg_size(bmsg);
 361         start = align(bsz);
 362         pad = start - bsz;
 363
 364         if (unlikely(msg_user(msg) == TUNNEL_PROTOCOL))
 365                 return false;
 366         if (unlikely(msg_user(msg) == BCAST_PROTOCOL))
 367                 return false;
 368         if (unlikely(msg_user(bmsg) != MSG_BUNDLER))
 369                 return false;
 370         if (unlikely(skb_tailroom(skb) < (pad + msz)))
 371                 return false;
 372         if (unlikely(max < (start + msz)))
 373                 return false;
 374         if ((msg_importance(msg) < TIPC_SYSTEM_IMPORTANCE) &&
 375             (msg_importance(bmsg) == TIPC_SYSTEM_IMPORTANCE))
 376                 return false;
 377
 378         skb_put(skb, pad + msz);
 379         skb_copy_to_linear_data_offset(skb, start, msg, msz);
 380         msg_set_size(bmsg, start + msz);
 381         msg_set_msgcnt(bmsg, msg_msgcnt(bmsg) + 1);
 382         return true;
 383 }
 384
 385 /**
 386  *  tipc_msg_extract(): extract bundled inner packet from buffer
 387  *  @skb: buffer to be extracted from.
 388  *  @iskb: extracted inner buffer, to be returned
 389  *  @pos: position in outer message of msg to be extracted.
 390  *        Returns position of next msg
 391  *  Consumes outer buffer when last packet extracted
 392  *  Returns true when when there is an extracted buffer, otherwise false
 393  */
 394 bool tipc_msg_extract(struct sk_buff *skb, struct sk_buff **iskb, int *pos)
 395 {
 396         struct tipc_msg *msg;
 397         int imsz, offset;
 398
 399         *iskb = NULL;
 400         if (unlikely(skb_linearize(skb)))
 401                 goto none;
 402
 403         msg = buf_msg(skb);
 404         offset = msg_hdr_sz(msg) + *pos;
 405         if (unlikely(offset > (msg_size(msg) - MIN_H_SIZE)))
 406                 goto none;
 407
 408         *iskb = skb_clone(skb, GFP_ATOMIC);
 409         if (unlikely(!*iskb))
 410                 goto none;
 411         skb_pull(*iskb, offset);
 412         imsz = msg_size(buf_msg(*iskb));
 413         skb_trim(*iskb, imsz);
 414         if (unlikely(!tipc_msg_validate(*iskb)))
 415                 goto none;
 416         *pos += align(imsz);
 417         return true;
 418 none:
 419         kfree_skb(skb);
 420         kfree_skb(*iskb);
 421         *iskb = NULL;
 422         return false;
 423 }
 424
 425 /**
 426  * tipc_msg_make_bundle(): Create bundle buf and append message to its tail
 427  * @list: the buffer chain, where head is the buffer to replace/append
 428  * @skb: buffer to be created, appended to and returned in case of success
 429  * @msg: message to be appended
 430  * @mtu: max allowable size for the bundle buffer, inclusive header
 431  * @dnode: destination node for message. (Not always present in header)
 432  * Returns true if success, otherwise false
 433  */
 434 bool tipc_msg_make_bundle(struct sk_buff **skb,  struct tipc_msg *msg,
 435                           u32 mtu, u32 dnode)
 436 {
 437         struct sk_buff *_skb;
 438         struct tipc_msg *bmsg;
 439         u32 msz = msg_size(msg);
 440         u32 max = mtu - INT_H_SIZE;
 441
 442         if (msg_user(msg) == MSG_FRAGMENTER)
 443                 return false;
 444         if (msg_user(msg) == TUNNEL_PROTOCOL)
 445                 return false;
 446         if (msg_user(msg) == BCAST_PROTOCOL)
 447                 return false;
 448         if (msz > (max / 2))
 449                 return false;
 450
 451         _skb = tipc_buf_acquire(max, GFP_ATOMIC);
 452         if (!_skb)
 453                 return false;
 454
 455         skb_trim(_skb, INT_H_SIZE);
 456         bmsg = buf_msg(_skb);
 457         tipc_msg_init(msg_prevnode(msg), bmsg, MSG_BUNDLER, 0,
 458                       INT_H_SIZE, dnode);
 459         if (msg_isdata(msg))
 460                 msg_set_importance(bmsg, TIPC_CRITICAL_IMPORTANCE);
 461         else
 462                 msg_set_importance(bmsg, TIPC_SYSTEM_IMPORTANCE);
 463         msg_set_seqno(bmsg, msg_seqno(msg));
 464         msg_set_ack(bmsg, msg_ack(msg));
 465         msg_set_bcast_ack(bmsg, msg_bcast_ack(msg));
 466         tipc_msg_bundle(_skb, msg, mtu);
 467         *skb = _skb;
 468         return true;
 469 }
 470
 471 /**
 472  * tipc_msg_reverse(): swap source and destination addresses and add error code
 473  * @own_node: originating node id for reversed message
 474  * @skb:  buffer containing message to be reversed; may be replaced.
 475  * @err:  error code to be set in message, if any
 476  * Consumes buffer at failure
 477  * Returns true if success, otherwise false
 478  */
 479 bool tipc_msg_reverse(u32 own_node,  struct sk_buff **skb, int err)
 480 {
 481         struct sk_buff *_skb = *skb;
 482         struct tipc_msg *hdr = buf_msg(_skb);
 483         struct tipc_msg ohdr;
 484         int dlen = min_t(uint, msg_data_sz(hdr), MAX_FORWARD_SIZE);
 485
 486         if (skb_linearize(_skb))
 487                 goto exit;
 488         hdr = buf_msg(_skb);
 489         if (msg_dest_droppable(hdr))
 490                 goto exit;
 491         if (msg_errcode(hdr))
 492                 goto exit;
 493
 494         /* Take a copy of original header before altering message */
 495         memcpy(&ohdr, hdr, msg_hdr_sz(hdr));
 496
 497         /* Never return SHORT header; expand by replacing buffer if necessary */
 498         if (msg_short(hdr)) {
 499                 *skb = tipc_buf_acquire(BASIC_H_SIZE + dlen, GFP_ATOMIC);
 500                 if (!*skb)
 501                         goto exit;
 502                 memcpy((*skb)->data + BASIC_H_SIZE, msg_data(hdr), dlen);
 503                 kfree_skb(_skb);
 504                 _skb = *skb;
 505                 hdr = buf_msg(_skb);
 506                 memcpy(hdr, &ohdr, BASIC_H_SIZE);
 507                 msg_set_hdr_sz(hdr, BASIC_H_SIZE);
 508         }
 509
 510         if (skb_cloned(_skb) &&
 511             pskb_expand_head(_skb, BUF_HEADROOM, BUF_TAILROOM, GFP_ATOMIC))
 512                 goto exit;
 513
 514         /* Now reverse the concerned fields */
 515         msg_set_errcode(hdr, err);
 516         msg_set_non_seq(hdr, 0);
 517         msg_set_origport(hdr, msg_destport(&ohdr));
 518         msg_set_destport(hdr, msg_origport(&ohdr));
 519         msg_set_destnode(hdr, msg_prevnode(&ohdr));
 520         msg_set_prevnode(hdr, own_node);
 521         msg_set_orignode(hdr, own_node);
 522         msg_set_size(hdr, msg_hdr_sz(hdr) + dlen);
 523         skb_trim(_skb, msg_size(hdr));
 524         skb_orphan(_skb);
 525         return true;
 526 exit:
 527         kfree_skb(_skb);
 528         *skb = NULL;
 529         return false;
 530 }
 531
 532 /**
 533  * tipc_msg_lookup_dest(): try to find new destination for named message
 534  * @skb: the buffer containing the message.
 535  * @err: error code to be used by caller if lookup fails
 536  * Does not consume buffer
 537  * Returns true if a destination is found, false otherwise
 538  */
 539 bool tipc_msg_lookup_dest(struct net *net, struct sk_buff *skb, int *err)
 540 {
 541         struct tipc_msg *msg = buf_msg(skb);
 542         u32 dport, dnode;
 543         u32 onode = tipc_own_addr(net);
 544
 545         if (!msg_isdata(msg))
 546                 return false;
 547         if (!msg_named(msg))
 548                 return false;
 549         if (msg_errcode(msg))
 550                 return false;
 551         *err = -TIPC_ERR_NO_NAME;
 552         if (skb_linearize(skb))
 553                 return false;
 554         msg = buf_msg(skb);
 555         if (msg_reroute_cnt(msg))
 556                 return false;
 557         dnode = addr_domain(net, msg_lookup_scope(msg));
 558         dport = tipc_nametbl_translate(net, msg_nametype(msg),
 559                                        msg_nameinst(msg), &dnode);
 560         if (!dport)
 561                 return false;
 562         msg_incr_reroute_cnt(msg);
 563         if (dnode != onode)
 564                 msg_set_prevnode(msg, onode);
 565         msg_set_destnode(msg, dnode);
 566         msg_set_destport(msg, dport);
 567         *err = TIPC_OK;
 568         return true;
 569 }
 570
 571 /* tipc_msg_reassemble() - clone a buffer chain of fragments and
 572  *                         reassemble the clones into one message
 573  */
 574 bool tipc_msg_reassemble(struct sk_buff_head *list, struct sk_buff_head *rcvq)
 575 {
 576         struct sk_buff *skb, *_skb;
 577         struct sk_buff *frag = NULL;
 578         struct sk_buff *head = NULL;
 579         int hdr_len;
 580
 581         /* Copy header if single buffer */
 582         if (skb_queue_len(list) == 1) {
 583                 skb = skb_peek(list);
 584                 hdr_len = skb_headroom(skb) + msg_hdr_sz(buf_msg(skb));
 585                 _skb = __pskb_copy(skb, hdr_len, GFP_ATOMIC);
 586                 if (!_skb)
 587                         return false;
 588                 __skb_queue_tail(rcvq, _skb);
 589                 return true;
 590         }
 591
 592         /* Clone all fragments and reassemble */
 593         skb_queue_walk(list, skb) {
 594                 frag = skb_clone(skb, GFP_ATOMIC);
 595                 if (!frag)
 596                         goto error;
 597                 frag->next = NULL;
 598                 if (tipc_buf_append(&head, &frag))
 599                         break;
 600                 if (!head)
 601                         goto error;
 602         }
 603         __skb_queue_tail(rcvq, frag);
 604         return true;
 605 error:
 606         pr_warn("Failed do clone local mcast rcv buffer\n");
 607         kfree_skb(head);
 608         return false;
 609 }
 610
 611 bool tipc_msg_pskb_copy(u32 dst, struct sk_buff_head *msg,
 612                         struct sk_buff_head *cpy)
 613 {
 614         struct sk_buff *skb, *_skb;
 615
 616         skb_queue_walk(msg, skb) {
 617                 _skb = pskb_copy(skb, GFP_ATOMIC);
 618                 if (!_skb) {
 619                         __skb_queue_purge(cpy);
 620                         return false;
 621                 }
 622                 msg_set_destnode(buf_msg(_skb), dst);
 623                 __skb_queue_tail(cpy, _skb);
 624         }
 625         return true;
 626 }
 627
 628 /* tipc_skb_queue_sorted(); sort pkt into list according to sequence number
 629  * @list: list to be appended to
 630  * @seqno: sequence number of buffer to add
 631  * @skb: buffer to add
 632  */
 633 void __tipc_skb_queue_sorted(struct sk_buff_head *list, u16 seqno,
 634                              struct sk_buff *skb)
 635 {
 636         struct sk_buff *_skb, *tmp;
 637
 638         if (skb_queue_empty(list) || less(seqno, buf_seqno(skb_peek(list)))) {
 639                 __skb_queue_head(list, skb);
 640                 return;
 641         }
 642
 643         if (more(seqno, buf_seqno(skb_peek_tail(list)))) {
 644                 __skb_queue_tail(list, skb);
 645                 return;
 646         }
 647
 648         skb_queue_walk_safe(list, _skb, tmp) {
 649                 if (more(seqno, buf_seqno(_skb)))
 650                         continue;
 651                 if (seqno == buf_seqno(_skb))
 652                         break;
 653                 __skb_queue_before(list, _skb, skb);
 654                 return;
 655         }
 656         kfree_skb(skb);
 657 }