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 #include "crypto.h"
  43
  44 #define MAX_FORWARD_SIZE 1024
  45 #ifdef CONFIG_TIPC_CRYPTO
  46 #define BUF_HEADROOM ALIGN(((LL_MAX_HEADER + 48) + EHDR_MAX_SIZE), 16)
  47 #define BUF_TAILROOM (TIPC_AES_GCM_TAG_SIZE)
  48 #else
  49 #define BUF_HEADROOM (LL_MAX_HEADER + 48)
  50 #define BUF_TAILROOM 16
  51 #endif
  52
  53 static unsigned int align(unsigned int i)
  54 {
  55         return (i + 3) & ~3u;
  56 }
  57
  58 /**
  59  * tipc_buf_acquire - creates a TIPC message buffer
  60  * @size: message size (including TIPC header)
  61  * @gfp: memory allocation flags
  62  *
  63  * Return: a new buffer with data pointers set to the specified size.
  64  *
  65  * NOTE:
  66  * Headroom is reserved to allow prepending of a data link header.
  67  * There may also be unrequested tailroom present at the buffer's end.
  68  */
  69 struct sk_buff *tipc_buf_acquire(u32 size, gfp_t gfp)
  70 {
  71         struct sk_buff *skb;
  72 #ifdef CONFIG_TIPC_CRYPTO
  73         unsigned int buf_size = (BUF_HEADROOM + size + BUF_TAILROOM + 3) & ~3u;
  74 #else
  75         unsigned int buf_size = (BUF_HEADROOM + size + 3) & ~3u;
  76 #endif
  77
  78         skb = alloc_skb_fclone(buf_size, gfp);
  79         if (skb) {
  80                 skb_reserve(skb, BUF_HEADROOM);
  81                 skb_put(skb, size);
  82                 skb->next = NULL;
  83         }
  84         return skb;
  85 }
  86
  87 void tipc_msg_init(u32 own_node, struct tipc_msg *m, u32 user, u32 type,
  88                    u32 hsize, u32 dnode)
  89 {
  90         memset(m, 0, hsize);
  91         msg_set_version(m);
  92         msg_set_user(m, user);
  93         msg_set_hdr_sz(m, hsize);
  94         msg_set_size(m, hsize);
  95         msg_set_prevnode(m, own_node);
  96         msg_set_type(m, type);
  97         if (hsize > SHORT_H_SIZE) {
  98                 msg_set_orignode(m, own_node);
  99                 msg_set_destnode(m, dnode);
 100         }
 101 }
 102
 103 struct sk_buff *tipc_msg_create(uint user, uint type,
 104                                 uint hdr_sz, uint data_sz, u32 dnode,
 105                                 u32 onode, u32 dport, u32 oport, int errcode)
 106 {
 107         struct tipc_msg *msg;
 108         struct sk_buff *buf;
 109
 110         buf = tipc_buf_acquire(hdr_sz + data_sz, GFP_ATOMIC);
 111         if (unlikely(!buf))
 112                 return NULL;
 113
 114         msg = buf_msg(buf);
 115         tipc_msg_init(onode, msg, user, type, hdr_sz, dnode);
 116         msg_set_size(msg, hdr_sz + data_sz);
 117         msg_set_origport(msg, oport);
 118         msg_set_destport(msg, dport);
 119         msg_set_errcode(msg, errcode);
 120         if (hdr_sz > SHORT_H_SIZE) {
 121                 msg_set_orignode(msg, onode);
 122                 msg_set_destnode(msg, dnode);
 123         }
 124         return buf;
 125 }
 126
 127 /* tipc_buf_append(): Append a buffer to the fragment list of another buffer
 128  * @*headbuf: in:  NULL for first frag, otherwise value returned from prev call
 129  *            out: set when successful non-complete reassembly, otherwise NULL
 130  * @*buf:     in:  the buffer to append. Always defined
 131  *            out: head buf after successful complete reassembly, otherwise NULL
 132  * Returns 1 when reassembly complete, otherwise 0
 133  */
 134 int tipc_buf_append(struct sk_buff **headbuf, struct sk_buff **buf)
 135 {
 136         struct sk_buff *head = *headbuf;
 137         struct sk_buff *frag = *buf;
 138         struct sk_buff *tail = NULL;
 139         struct tipc_msg *msg;
 140         u32 fragid;
 141         int delta;
 142         bool headstolen;
 143
 144         if (!frag)
 145                 goto err;
 146
 147         msg = buf_msg(frag);
 148         fragid = msg_type(msg);
 149         frag->next = NULL;
 150         skb_pull(frag, msg_hdr_sz(msg));
 151
 152         if (fragid == FIRST_FRAGMENT) {
 153                 if (unlikely(head))
 154                         goto err;
 155                 *buf = NULL;
 156                 frag = skb_unshare(frag, GFP_ATOMIC);
 157                 if (unlikely(!frag))
 158                         goto err;
 159                 head = *headbuf = frag;
 160                 TIPC_SKB_CB(head)->tail = NULL;
 161                 if (skb_is_nonlinear(head)) {
 162                         skb_walk_frags(head, tail) {
 163                                 TIPC_SKB_CB(head)->tail = tail;
 164                         }
 165                 } else {
 166                         skb_frag_list_init(head);
 167                 }
 168                 return 0;
 169         }
 170
 171         if (!head)
 172                 goto err;
 173
 174         if (skb_try_coalesce(head, frag, &headstolen, &delta)) {
 175                 kfree_skb_partial(frag, headstolen);
 176         } else {
 177                 tail = TIPC_SKB_CB(head)->tail;
 178                 if (!skb_has_frag_list(head))
 179                         skb_shinfo(head)->frag_list = frag;
 180                 else
 181                         tail->next = frag;
 182                 head->truesize += frag->truesize;
 183                 head->data_len += frag->len;
 184                 head->len += frag->len;
 185                 TIPC_SKB_CB(head)->tail = frag;
 186         }
 187
 188         if (fragid == LAST_FRAGMENT) {
 189                 TIPC_SKB_CB(head)->validated = 0;
 190                 if (unlikely(!tipc_msg_validate(&head)))
 191                         goto err;
 192                 *buf = head;
 193                 TIPC_SKB_CB(head)->tail = NULL;
 194                 *headbuf = NULL;
 195                 return 1;
 196         }
 197         *buf = NULL;
 198         return 0;
 199 err:
 200         kfree_skb(*buf);
 201         kfree_skb(*headbuf);
 202         *buf = *headbuf = NULL;
 203         return 0;
 204 }
 205
 206 /**
 207  * tipc_msg_append(): Append data to tail of an existing buffer queue
 208  * @_hdr: header to be used
 209  * @m: the data to be appended
 210  * @mss: max allowable size of buffer
 211  * @dlen: size of data to be appended
 212  * @txq: queue to append to
 213  *
 214  * Return: the number of 1k blocks appended or errno value
 215  */
 216 int tipc_msg_append(struct tipc_msg *_hdr, struct msghdr *m, int dlen,
 217                     int mss, struct sk_buff_head *txq)
 218 {
 219         struct sk_buff *skb;
 220         int accounted, total, curr;
 221         int mlen, cpy, rem = dlen;
 222         struct tipc_msg *hdr;
 223
 224         skb = skb_peek_tail(txq);
 225         accounted = skb ? msg_blocks(buf_msg(skb)) : 0;
 226         total = accounted;
 227
 228         do {
 229                 if (!skb || skb->len >= mss) {
 230                         skb = tipc_buf_acquire(mss, GFP_KERNEL);
 231                         if (unlikely(!skb))
 232                                 return -ENOMEM;
 233                         skb_orphan(skb);
 234                         skb_trim(skb, MIN_H_SIZE);
 235                         hdr = buf_msg(skb);
 236                         skb_copy_to_linear_data(skb, _hdr, MIN_H_SIZE);
 237                         msg_set_hdr_sz(hdr, MIN_H_SIZE);
 238                         msg_set_size(hdr, MIN_H_SIZE);
 239                         __skb_queue_tail(txq, skb);
 240                         total += 1;
 241                 }
 242                 hdr = buf_msg(skb);
 243                 curr = msg_blocks(hdr);
 244                 mlen = msg_size(hdr);
 245                 cpy = min_t(size_t, rem, mss - mlen);
 246                 if (cpy != copy_from_iter(skb->data + mlen, cpy, &m->msg_iter))
 247                         return -EFAULT;
 248                 msg_set_size(hdr, mlen + cpy);
 249                 skb_put(skb, cpy);
 250                 rem -= cpy;
 251                 total += msg_blocks(hdr) - curr;
 252         } while (rem > 0);
 253         return total - accounted;
 254 }
 255
 256 /* tipc_msg_validate - validate basic format of received message
 257  *
 258  * This routine ensures a TIPC message has an acceptable header, and at least
 259  * as much data as the header indicates it should.  The routine also ensures
 260  * that the entire message header is stored in the main fragment of the message
 261  * buffer, to simplify future access to message header fields.
 262  *
 263  * Note: Having extra info present in the message header or data areas is OK.
 264  * TIPC will ignore the excess, under the assumption that it is optional info
 265  * introduced by a later release of the protocol.
 266  */
 267 bool tipc_msg_validate(struct sk_buff **_skb)
 268 {
 269         struct sk_buff *skb = *_skb;
 270         struct tipc_msg *hdr;
 271         int msz, hsz;
 272
 273         /* Ensure that flow control ratio condition is satisfied */
 274         if (unlikely(skb->truesize / buf_roundup_len(skb) >= 4)) {
 275                 skb = skb_copy_expand(skb, BUF_HEADROOM, 0, GFP_ATOMIC);
 276                 if (!skb)
 277                         return false;
 278                 kfree_skb(*_skb);
 279                 *_skb = skb;
 280         }
 281
 282         if (unlikely(TIPC_SKB_CB(skb)->validated))
 283                 return true;
 284
 285         if (unlikely(!pskb_may_pull(skb, MIN_H_SIZE)))
 286                 return false;
 287
 288         hsz = msg_hdr_sz(buf_msg(skb));
 289         if (unlikely(hsz < MIN_H_SIZE) || (hsz > MAX_H_SIZE))
 290                 return false;
 291         if (unlikely(!pskb_may_pull(skb, hsz)))
 292                 return false;
 293
 294         hdr = buf_msg(skb);
 295         if (unlikely(msg_version(hdr) != TIPC_VERSION))
 296                 return false;
 297
 298         msz = msg_size(hdr);
 299         if (unlikely(msz < hsz))
 300                 return false;
 301         if (unlikely((msz - hsz) > TIPC_MAX_USER_MSG_SIZE))
 302                 return false;
 303         if (unlikely(skb->len < msz))
 304                 return false;
 305
 306         TIPC_SKB_CB(skb)->validated = 1;
 307         return true;
 308 }
 309
 310 /**
 311  * tipc_msg_fragment - build a fragment skb list for TIPC message
 312  *
 313  * @skb: TIPC message skb
 314  * @hdr: internal msg header to be put on the top of the fragments
 315  * @pktmax: max size of a fragment incl. the header
 316  * @frags: returned fragment skb list
 317  *
 318  * Return: 0 if the fragmentation is successful, otherwise: -EINVAL
 319  * or -ENOMEM
 320  */
 321 int tipc_msg_fragment(struct sk_buff *skb, const struct tipc_msg *hdr,
 322                       int pktmax, struct sk_buff_head *frags)
 323 {
 324         int pktno, nof_fragms, dsz, dmax, eat;
 325         struct tipc_msg *_hdr;
 326         struct sk_buff *_skb;
 327         u8 *data;
 328
 329         /* Non-linear buffer? */
 330         if (skb_linearize(skb))
 331                 return -ENOMEM;
 332
 333         data = (u8 *)skb->data;
 334         dsz = msg_size(buf_msg(skb));
 335         dmax = pktmax - INT_H_SIZE;
 336         if (dsz <= dmax || !dmax)
 337                 return -EINVAL;
 338
 339         nof_fragms = dsz / dmax + 1;
 340         for (pktno = 1; pktno <= nof_fragms; pktno++) {
 341                 if (pktno < nof_fragms)
 342                         eat = dmax;
 343                 else
 344                         eat = dsz % dmax;
 345                 /* Allocate a new fragment */
 346                 _skb = tipc_buf_acquire(INT_H_SIZE + eat, GFP_ATOMIC);
 347                 if (!_skb)
 348                         goto error;
 349                 skb_orphan(_skb);
 350                 __skb_queue_tail(frags, _skb);
 351                 /* Copy header & data to the fragment */
 352                 skb_copy_to_linear_data(_skb, hdr, INT_H_SIZE);
 353                 skb_copy_to_linear_data_offset(_skb, INT_H_SIZE, data, eat);
 354                 data += eat;
 355                 /* Update the fragment's header */
 356                 _hdr = buf_msg(_skb);
 357                 msg_set_fragm_no(_hdr, pktno);
 358                 msg_set_nof_fragms(_hdr, nof_fragms);
 359                 msg_set_size(_hdr, INT_H_SIZE + eat);
 360         }
 361         return 0;
 362
 363 error:
 364         __skb_queue_purge(frags);
 365         __skb_queue_head_init(frags);
 366         return -ENOMEM;
 367 }
 368
 369 /**
 370  * tipc_msg_build - create buffer chain containing specified header and data
 371  * @mhdr: Message header, to be prepended to data
 372  * @m: User message
 373  * @offset: buffer offset for fragmented messages (FIXME)
 374  * @dsz: Total length of user data
 375  * @pktmax: Max packet size that can be used
 376  * @list: Buffer or chain of buffers to be returned to caller
 377  *
 378  * Note that the recursive call we are making here is safe, since it can
 379  * logically go only one further level down.
 380  *
 381  * Return: message data size or errno: -ENOMEM, -EFAULT
 382  */
 383 int tipc_msg_build(struct tipc_msg *mhdr, struct msghdr *m, int offset,
 384                    int dsz, int pktmax, struct sk_buff_head *list)
 385 {
 386         int mhsz = msg_hdr_sz(mhdr);
 387         struct tipc_msg pkthdr;
 388         int msz = mhsz + dsz;
 389         int pktrem = pktmax;
 390         struct sk_buff *skb;
 391         int drem = dsz;
 392         int pktno = 1;
 393         char *pktpos;
 394         int pktsz;
 395         int rc;
 396
 397         msg_set_size(mhdr, msz);
 398
 399         /* No fragmentation needed? */
 400         if (likely(msz <= pktmax)) {
 401                 skb = tipc_buf_acquire(msz, GFP_KERNEL);
 402
 403                 /* Fall back to smaller MTU if node local message */
 404                 if (unlikely(!skb)) {
 405                         if (pktmax != MAX_MSG_SIZE)
 406                                 return -ENOMEM;
 407                         rc = tipc_msg_build(mhdr, m, offset, dsz, FB_MTU, list);
 408                         if (rc != dsz)
 409                                 return rc;
 410                         if (tipc_msg_assemble(list))
 411                                 return dsz;
 412                         return -ENOMEM;
 413                 }
 414                 skb_orphan(skb);
 415                 __skb_queue_tail(list, skb);
 416                 skb_copy_to_linear_data(skb, mhdr, mhsz);
 417                 pktpos = skb->data + mhsz;
 418                 if (copy_from_iter_full(pktpos, dsz, &m->msg_iter))
 419                         return dsz;
 420                 rc = -EFAULT;
 421                 goto error;
 422         }
 423
 424         /* Prepare reusable fragment header */
 425         tipc_msg_init(msg_prevnode(mhdr), &pkthdr, MSG_FRAGMENTER,
 426                       FIRST_FRAGMENT, INT_H_SIZE, msg_destnode(mhdr));
 427         msg_set_size(&pkthdr, pktmax);
 428         msg_set_fragm_no(&pkthdr, pktno);
 429         msg_set_importance(&pkthdr, msg_importance(mhdr));
 430
 431         /* Prepare first fragment */
 432         skb = tipc_buf_acquire(pktmax, GFP_KERNEL);
 433         if (!skb)
 434                 return -ENOMEM;
 435         skb_orphan(skb);
 436         __skb_queue_tail(list, skb);
 437         pktpos = skb->data;
 438         skb_copy_to_linear_data(skb, &pkthdr, INT_H_SIZE);
 439         pktpos += INT_H_SIZE;
 440         pktrem -= INT_H_SIZE;
 441         skb_copy_to_linear_data_offset(skb, INT_H_SIZE, mhdr, mhsz);
 442         pktpos += mhsz;
 443         pktrem -= mhsz;
 444
 445         do {
 446                 if (drem < pktrem)
 447                         pktrem = drem;
 448
 449                 if (!copy_from_iter_full(pktpos, pktrem, &m->msg_iter)) {
 450                         rc = -EFAULT;
 451                         goto error;
 452                 }
 453                 drem -= pktrem;
 454
 455                 if (!drem)
 456                         break;
 457
 458                 /* Prepare new fragment: */
 459                 if (drem < (pktmax - INT_H_SIZE))
 460                         pktsz = drem + INT_H_SIZE;
 461                 else
 462                         pktsz = pktmax;
 463                 skb = tipc_buf_acquire(pktsz, GFP_KERNEL);
 464                 if (!skb) {
 465                         rc = -ENOMEM;
 466                         goto error;
 467                 }
 468                 skb_orphan(skb);
 469                 __skb_queue_tail(list, skb);
 470                 msg_set_type(&pkthdr, FRAGMENT);
 471                 msg_set_size(&pkthdr, pktsz);
 472                 msg_set_fragm_no(&pkthdr, ++pktno);
 473                 skb_copy_to_linear_data(skb, &pkthdr, INT_H_SIZE);
 474                 pktpos = skb->data + INT_H_SIZE;
 475                 pktrem = pktsz - INT_H_SIZE;
 476
 477         } while (1);
 478         msg_set_type(buf_msg(skb), LAST_FRAGMENT);
 479         return dsz;
 480 error:
 481         __skb_queue_purge(list);
 482         __skb_queue_head_init(list);
 483         return rc;
 484 }
 485
 486 /**
 487  * tipc_msg_bundle - Append contents of a buffer to tail of an existing one
 488  * @bskb: the bundle buffer to append to
 489  * @msg: message to be appended
 490  * @max: max allowable size for the bundle buffer
 491  *
 492  * Return: "true" if bundling has been performed, otherwise "false"
 493  */
 494 static bool tipc_msg_bundle(struct sk_buff *bskb, struct tipc_msg *msg,
 495                             u32 max)
 496 {
 497         struct tipc_msg *bmsg = buf_msg(bskb);
 498         u32 msz, bsz, offset, pad;
 499
 500         msz = msg_size(msg);
 501         bsz = msg_size(bmsg);
 502         offset = align(bsz);
 503         pad = offset - bsz;
 504
 505         if (unlikely(skb_tailroom(bskb) < (pad + msz)))
 506                 return false;
 507         if (unlikely(max < (offset + msz)))
 508                 return false;
 509
 510         skb_put(bskb, pad + msz);
 511         skb_copy_to_linear_data_offset(bskb, offset, msg, msz);
 512         msg_set_size(bmsg, offset + msz);
 513         msg_set_msgcnt(bmsg, msg_msgcnt(bmsg) + 1);
 514         return true;
 515 }
 516
 517 /**
 518  * tipc_msg_try_bundle - Try to bundle a new message to the last one
 519  * @tskb: the last/target message to which the new one will be appended
 520  * @skb: the new message skb pointer
 521  * @mss: max message size (header inclusive)
 522  * @dnode: destination node for the message
 523  * @new_bundle: if this call made a new bundle or not
 524  *
 525  * Return: "true" if the new message skb is potential for bundling this time or
 526  * later, in the case a bundling has been done this time, the skb is consumed
 527  * (the skb pointer = NULL).
 528  * Otherwise, "false" if the skb cannot be bundled at all.
 529  */
 530 bool tipc_msg_try_bundle(struct sk_buff *tskb, struct sk_buff **skb, u32 mss,
 531                          u32 dnode, bool *new_bundle)
 532 {
 533         struct tipc_msg *msg, *inner, *outer;
 534         u32 tsz;
 535
 536         /* First, check if the new buffer is suitable for bundling */
 537         msg = buf_msg(*skb);
 538         if (msg_user(msg) == MSG_FRAGMENTER)
 539                 return false;
 540         if (msg_user(msg) == TUNNEL_PROTOCOL)
 541                 return false;
 542         if (msg_user(msg) == BCAST_PROTOCOL)
 543                 return false;
 544         if (mss <= INT_H_SIZE + msg_size(msg))
 545                 return false;
 546
 547         /* Ok, but the last/target buffer can be empty? */
 548         if (unlikely(!tskb))
 549                 return true;
 550
 551         /* Is it a bundle already? Try to bundle the new message to it */
 552         if (msg_user(buf_msg(tskb)) == MSG_BUNDLER) {
 553                 *new_bundle = false;
 554                 goto bundle;
 555         }
 556
 557         /* Make a new bundle of the two messages if possible */
 558         tsz = msg_size(buf_msg(tskb));
 559         if (unlikely(mss < align(INT_H_SIZE + tsz) + msg_size(msg)))
 560                 return true;
 561         if (unlikely(pskb_expand_head(tskb, INT_H_SIZE, mss - tsz - INT_H_SIZE,
 562                                       GFP_ATOMIC)))
 563                 return true;
 564         inner = buf_msg(tskb);
 565         skb_push(tskb, INT_H_SIZE);
 566         outer = buf_msg(tskb);
 567         tipc_msg_init(msg_prevnode(inner), outer, MSG_BUNDLER, 0, INT_H_SIZE,
 568                       dnode);
 569         msg_set_importance(outer, msg_importance(inner));
 570         msg_set_size(outer, INT_H_SIZE + tsz);
 571         msg_set_msgcnt(outer, 1);
 572         *new_bundle = true;
 573
 574 bundle:
 575         if (likely(tipc_msg_bundle(tskb, msg, mss))) {
 576                 consume_skb(*skb);
 577                 *skb = NULL;
 578         }
 579         return true;
 580 }
 581
 582 /**
 583  *  tipc_msg_extract(): extract bundled inner packet from buffer
 584  *  @skb: buffer to be extracted from.
 585  *  @iskb: extracted inner buffer, to be returned
 586  *  @pos: position in outer message of msg to be extracted.
 587  *  Returns position of next msg.
 588  *  Consumes outer buffer when last packet extracted
 589  *  Return: true when there is an extracted buffer, otherwise false
 590  */
 591 bool tipc_msg_extract(struct sk_buff *skb, struct sk_buff **iskb, int *pos)
 592 {
 593         struct tipc_msg *hdr, *ihdr;
 594         int imsz;
 595
 596         *iskb = NULL;
 597         if (unlikely(skb_linearize(skb)))
 598                 goto none;
 599
 600         hdr = buf_msg(skb);
 601         if (unlikely(*pos > (msg_data_sz(hdr) - MIN_H_SIZE)))
 602                 goto none;
 603
 604         ihdr = (struct tipc_msg *)(msg_data(hdr) + *pos);
 605         imsz = msg_size(ihdr);
 606
 607         if ((*pos + imsz) > msg_data_sz(hdr))
 608                 goto none;
 609
 610         *iskb = tipc_buf_acquire(imsz, GFP_ATOMIC);
 611         if (!*iskb)
 612                 goto none;
 613
 614         skb_copy_to_linear_data(*iskb, ihdr, imsz);
 615         if (unlikely(!tipc_msg_validate(iskb)))
 616                 goto none;
 617
 618         *pos += align(imsz);
 619         return true;
 620 none:
 621         kfree_skb(skb);
 622         kfree_skb(*iskb);
 623         *iskb = NULL;
 624         return false;
 625 }
 626
 627 /**
 628  * tipc_msg_reverse(): swap source and destination addresses and add error code
 629  * @own_node: originating node id for reversed message
 630  * @skb:  buffer containing message to be reversed; will be consumed
 631  * @err:  error code to be set in message, if any
 632  * Replaces consumed buffer with new one when successful
 633  * Return: true if success, otherwise false
 634  */
 635 bool tipc_msg_reverse(u32 own_node,  struct sk_buff **skb, int err)
 636 {
 637         struct sk_buff *_skb = *skb;
 638         struct tipc_msg *_hdr, *hdr;
 639         int hlen, dlen;
 640
 641         if (skb_linearize(_skb))
 642                 goto exit;
 643         _hdr = buf_msg(_skb);
 644         dlen = min_t(uint, msg_data_sz(_hdr), MAX_FORWARD_SIZE);
 645         hlen = msg_hdr_sz(_hdr);
 646
 647         if (msg_dest_droppable(_hdr))
 648                 goto exit;
 649         if (msg_errcode(_hdr))
 650                 goto exit;
 651
 652         /* Never return SHORT header */
 653         if (hlen == SHORT_H_SIZE)
 654                 hlen = BASIC_H_SIZE;
 655
 656         /* Don't return data along with SYN+, - sender has a clone */
 657         if (msg_is_syn(_hdr) && err == TIPC_ERR_OVERLOAD)
 658                 dlen = 0;
 659
 660         /* Allocate new buffer to return */
 661         *skb = tipc_buf_acquire(hlen + dlen, GFP_ATOMIC);
 662         if (!*skb)
 663                 goto exit;
 664         memcpy((*skb)->data, _skb->data, msg_hdr_sz(_hdr));
 665         memcpy((*skb)->data + hlen, msg_data(_hdr), dlen);
 666
 667         /* Build reverse header in new buffer */
 668         hdr = buf_msg(*skb);
 669         msg_set_hdr_sz(hdr, hlen);
 670         msg_set_errcode(hdr, err);
 671         msg_set_non_seq(hdr, 0);
 672         msg_set_origport(hdr, msg_destport(_hdr));
 673         msg_set_destport(hdr, msg_origport(_hdr));
 674         msg_set_destnode(hdr, msg_prevnode(_hdr));
 675         msg_set_prevnode(hdr, own_node);
 676         msg_set_orignode(hdr, own_node);
 677         msg_set_size(hdr, hlen + dlen);
 678         skb_orphan(_skb);
 679         kfree_skb(_skb);
 680         return true;
 681 exit:
 682         kfree_skb(_skb);
 683         *skb = NULL;
 684         return false;
 685 }
 686
 687 bool tipc_msg_skb_clone(struct sk_buff_head *msg, struct sk_buff_head *cpy)
 688 {
 689         struct sk_buff *skb, *_skb;
 690
 691         skb_queue_walk(msg, skb) {
 692                 _skb = skb_clone(skb, GFP_ATOMIC);
 693                 if (!_skb) {
 694                         __skb_queue_purge(cpy);
 695                         pr_err_ratelimited("Failed to clone buffer chain\n");
 696                         return false;
 697                 }
 698                 __skb_queue_tail(cpy, _skb);
 699         }
 700         return true;
 701 }
 702
 703 /**
 704  * tipc_msg_lookup_dest(): try to find new destination for named message
 705  * @net: pointer to associated network namespace
 706  * @skb: the buffer containing the message.
 707  * @err: error code to be used by caller if lookup fails
 708  * Does not consume buffer
 709  * Return: true if a destination is found, false otherwise
 710  */
 711 bool tipc_msg_lookup_dest(struct net *net, struct sk_buff *skb, int *err)
 712 {
 713         struct tipc_msg *msg = buf_msg(skb);
 714         u32 dport, dnode;
 715         u32 onode = tipc_own_addr(net);
 716
 717         if (!msg_isdata(msg))
 718                 return false;
 719         if (!msg_named(msg))
 720                 return false;
 721         if (msg_errcode(msg))
 722                 return false;
 723         *err = TIPC_ERR_NO_NAME;
 724         if (skb_linearize(skb))
 725                 return false;
 726         msg = buf_msg(skb);
 727         if (msg_reroute_cnt(msg))
 728                 return false;
 729         dnode = tipc_scope2node(net, msg_lookup_scope(msg));
 730         dport = tipc_nametbl_translate(net, msg_nametype(msg),
 731                                        msg_nameinst(msg), &dnode);
 732         if (!dport)
 733                 return false;
 734         msg_incr_reroute_cnt(msg);
 735         if (dnode != onode)
 736                 msg_set_prevnode(msg, onode);
 737         msg_set_destnode(msg, dnode);
 738         msg_set_destport(msg, dport);
 739         *err = TIPC_OK;
 740
 741         return true;
 742 }
 743
 744 /* tipc_msg_assemble() - assemble chain of fragments into one message
 745  */
 746 bool tipc_msg_assemble(struct sk_buff_head *list)
 747 {
 748         struct sk_buff *skb, *tmp = NULL;
 749
 750         if (skb_queue_len(list) == 1)
 751                 return true;
 752
 753         while ((skb = __skb_dequeue(list))) {
 754                 skb->next = NULL;
 755                 if (tipc_buf_append(&tmp, &skb)) {
 756                         __skb_queue_tail(list, skb);
 757                         return true;
 758                 }
 759                 if (!tmp)
 760                         break;
 761         }
 762         __skb_queue_purge(list);
 763         __skb_queue_head_init(list);
 764         pr_warn("Failed do assemble buffer\n");
 765         return false;
 766 }
 767
 768 /* tipc_msg_reassemble() - clone a buffer chain of fragments and
 769  *                         reassemble the clones into one message
 770  */
 771 bool tipc_msg_reassemble(struct sk_buff_head *list, struct sk_buff_head *rcvq)
 772 {
 773         struct sk_buff *skb, *_skb;
 774         struct sk_buff *frag = NULL;
 775         struct sk_buff *head = NULL;
 776         int hdr_len;
 777
 778         /* Copy header if single buffer */
 779         if (skb_queue_len(list) == 1) {
 780                 skb = skb_peek(list);
 781                 hdr_len = skb_headroom(skb) + msg_hdr_sz(buf_msg(skb));
 782                 _skb = __pskb_copy(skb, hdr_len, GFP_ATOMIC);
 783                 if (!_skb)
 784                         return false;
 785                 __skb_queue_tail(rcvq, _skb);
 786                 return true;
 787         }
 788
 789         /* Clone all fragments and reassemble */
 790         skb_queue_walk(list, skb) {
 791                 frag = skb_clone(skb, GFP_ATOMIC);
 792                 if (!frag)
 793                         goto error;
 794                 frag->next = NULL;
 795                 if (tipc_buf_append(&head, &frag))
 796                         break;
 797                 if (!head)
 798                         goto error;
 799         }
 800         __skb_queue_tail(rcvq, frag);
 801         return true;
 802 error:
 803         pr_warn("Failed do clone local mcast rcv buffer\n");
 804         kfree_skb(head);
 805         return false;
 806 }
 807
 808 bool tipc_msg_pskb_copy(u32 dst, struct sk_buff_head *msg,
 809                         struct sk_buff_head *cpy)
 810 {
 811         struct sk_buff *skb, *_skb;
 812
 813         skb_queue_walk(msg, skb) {
 814                 _skb = pskb_copy(skb, GFP_ATOMIC);
 815                 if (!_skb) {
 816                         __skb_queue_purge(cpy);
 817                         return false;
 818                 }
 819                 msg_set_destnode(buf_msg(_skb), dst);
 820                 __skb_queue_tail(cpy, _skb);
 821         }
 822         return true;
 823 }
 824
 825 /* tipc_skb_queue_sorted(); sort pkt into list according to sequence number
 826  * @list: list to be appended to
 827  * @seqno: sequence number of buffer to add
 828  * @skb: buffer to add
 829  */
 830 bool __tipc_skb_queue_sorted(struct sk_buff_head *list, u16 seqno,
 831                              struct sk_buff *skb)
 832 {
 833         struct sk_buff *_skb, *tmp;
 834
 835         if (skb_queue_empty(list) || less(seqno, buf_seqno(skb_peek(list)))) {
 836                 __skb_queue_head(list, skb);
 837                 return true;
 838         }
 839
 840         if (more(seqno, buf_seqno(skb_peek_tail(list)))) {
 841                 __skb_queue_tail(list, skb);
 842                 return true;
 843         }
 844
 845         skb_queue_walk_safe(list, _skb, tmp) {
 846                 if (more(seqno, buf_seqno(_skb)))
 847                         continue;
 848                 if (seqno == buf_seqno(_skb))
 849                         break;
 850                 __skb_queue_before(list, _skb, skb);
 851                 return true;
 852         }
 853         kfree_skb(skb);
 854         return false;
 855 }
 856
 857 void tipc_skb_reject(struct net *net, int err, struct sk_buff *skb,
 858                      struct sk_buff_head *xmitq)
 859 {
 860         if (tipc_msg_reverse(tipc_own_addr(net), &skb, err))
 861                 __skb_queue_tail(xmitq, skb);
 862 }