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1/*
2 * net/tipc/msg.c: TIPC message header routines
3 *
4 * Copyright (c) 2000-2006, 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 "core.h"
38#include "msg.h"
39
40u32 tipc_msg_tot_importance(struct tipc_msg *m)
41{
42 if (likely(msg_isdata(m))) {
43 if (likely(msg_orignode(m) == tipc_own_addr))
44 return msg_importance(m);
45 return msg_importance(m) + 4;
46 }
47 if ((msg_user(m) == MSG_FRAGMENTER) &&
48 (msg_type(m) == FIRST_FRAGMENT))
49 return msg_importance(msg_get_wrapped(m));
50 return msg_importance(m);
51}
52
53
54void tipc_msg_init(struct tipc_msg *m, u32 user, u32 type, u32 hsize,
55 u32 destnode)
56{
57 memset(m, 0, hsize);
58 msg_set_version(m);
59 msg_set_user(m, user);
60 msg_set_hdr_sz(m, hsize);
61 msg_set_size(m, hsize);
62 msg_set_prevnode(m, tipc_own_addr);
63 msg_set_type(m, type);
64 msg_set_orignode(m, tipc_own_addr);
65 msg_set_destnode(m, destnode);
66}
67
68/**
69 * tipc_msg_build - create message using specified header and data
70 *
71 * Note: Caller must not hold any locks in case copy_from_user() is interrupted!
72 *
73 * Returns message data size or errno
74 */
75int tipc_msg_build(struct tipc_msg *hdr, struct iovec const *msg_sect,
76 unsigned int len, int max_size, struct sk_buff **buf)
77{
78 int dsz, sz, hsz;
79 unsigned char *to;
80
81 dsz = len;
82 hsz = msg_hdr_sz(hdr);
83 sz = hsz + dsz;
84 msg_set_size(hdr, sz);
85 if (unlikely(sz > max_size)) {
86 *buf = NULL;
87 return dsz;
88 }
89
90 *buf = tipc_buf_acquire(sz);
91 if (!(*buf))
92 return -ENOMEM;
93 skb_copy_to_linear_data(*buf, hdr, hsz);
94 to = (*buf)->data + hsz;
95 if (len && memcpy_fromiovecend(to, msg_sect, 0, dsz)) {
96 kfree_skb(*buf);
97 *buf = NULL;
98 return -EFAULT;
99 }
100 return dsz;
101}
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
47static 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 */
61struct 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
75void 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
91struct 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 */
122int 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;
186err:
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 */
204bool tipc_msg_validate(struct sk_buff **_skb)
205{
206 struct sk_buff *skb = *_skb;
207 struct tipc_msg *hdr;
208 int msz, hsz;
209
210 /* Ensure that flow control ratio condition is satisfied */
211 if (unlikely(skb->truesize / buf_roundup_len(skb) >= 4)) {
212 skb = skb_copy_expand(skb, BUF_HEADROOM, 0, GFP_ATOMIC);
213 if (!skb)
214 return false;
215 kfree_skb(*_skb);
216 *_skb = skb;
217 }
218
219 if (unlikely(TIPC_SKB_CB(skb)->validated))
220 return true;
221 if (unlikely(!pskb_may_pull(skb, MIN_H_SIZE)))
222 return false;
223
224 hsz = msg_hdr_sz(buf_msg(skb));
225 if (unlikely(hsz < MIN_H_SIZE) || (hsz > MAX_H_SIZE))
226 return false;
227 if (unlikely(!pskb_may_pull(skb, hsz)))
228 return false;
229
230 hdr = buf_msg(skb);
231 if (unlikely(msg_version(hdr) != TIPC_VERSION))
232 return false;
233
234 msz = msg_size(hdr);
235 if (unlikely(msz < hsz))
236 return false;
237 if (unlikely((msz - hsz) > TIPC_MAX_USER_MSG_SIZE))
238 return false;
239 if (unlikely(skb->len < msz))
240 return false;
241
242 TIPC_SKB_CB(skb)->validated = true;
243 return true;
244}
245
246/**
247 * tipc_msg_build - create buffer chain containing specified header and data
248 * @mhdr: Message header, to be prepended to data
249 * @m: User message
250 * @dsz: Total length of user data
251 * @pktmax: Max packet size that can be used
252 * @list: Buffer or chain of buffers to be returned to caller
253 *
254 * Note that the recursive call we are making here is safe, since it can
255 * logically go only one further level down.
256 *
257 * Returns message data size or errno: -ENOMEM, -EFAULT
258 */
259int tipc_msg_build(struct tipc_msg *mhdr, struct msghdr *m, int offset,
260 int dsz, int pktmax, struct sk_buff_head *list)
261{
262 int mhsz = msg_hdr_sz(mhdr);
263 struct tipc_msg pkthdr;
264 int msz = mhsz + dsz;
265 int pktrem = pktmax;
266 struct sk_buff *skb;
267 int drem = dsz;
268 int pktno = 1;
269 char *pktpos;
270 int pktsz;
271 int rc;
272
273 msg_set_size(mhdr, msz);
274
275 /* No fragmentation needed? */
276 if (likely(msz <= pktmax)) {
277 skb = tipc_buf_acquire(msz, GFP_KERNEL);
278
279 /* Fall back to smaller MTU if node local message */
280 if (unlikely(!skb)) {
281 if (pktmax != MAX_MSG_SIZE)
282 return -ENOMEM;
283 rc = tipc_msg_build(mhdr, m, offset, dsz, FB_MTU, list);
284 if (rc != dsz)
285 return rc;
286 if (tipc_msg_assemble(list))
287 return dsz;
288 return -ENOMEM;
289 }
290 skb_orphan(skb);
291 __skb_queue_tail(list, skb);
292 skb_copy_to_linear_data(skb, mhdr, mhsz);
293 pktpos = skb->data + mhsz;
294 if (copy_from_iter_full(pktpos, dsz, &m->msg_iter))
295 return dsz;
296 rc = -EFAULT;
297 goto error;
298 }
299
300 /* Prepare reusable fragment header */
301 tipc_msg_init(msg_prevnode(mhdr), &pkthdr, MSG_FRAGMENTER,
302 FIRST_FRAGMENT, INT_H_SIZE, msg_destnode(mhdr));
303 msg_set_size(&pkthdr, pktmax);
304 msg_set_fragm_no(&pkthdr, pktno);
305 msg_set_importance(&pkthdr, msg_importance(mhdr));
306
307 /* Prepare first fragment */
308 skb = tipc_buf_acquire(pktmax, GFP_KERNEL);
309 if (!skb)
310 return -ENOMEM;
311 skb_orphan(skb);
312 __skb_queue_tail(list, skb);
313 pktpos = skb->data;
314 skb_copy_to_linear_data(skb, &pkthdr, INT_H_SIZE);
315 pktpos += INT_H_SIZE;
316 pktrem -= INT_H_SIZE;
317 skb_copy_to_linear_data_offset(skb, INT_H_SIZE, mhdr, mhsz);
318 pktpos += mhsz;
319 pktrem -= mhsz;
320
321 do {
322 if (drem < pktrem)
323 pktrem = drem;
324
325 if (!copy_from_iter_full(pktpos, pktrem, &m->msg_iter)) {
326 rc = -EFAULT;
327 goto error;
328 }
329 drem -= pktrem;
330
331 if (!drem)
332 break;
333
334 /* Prepare new fragment: */
335 if (drem < (pktmax - INT_H_SIZE))
336 pktsz = drem + INT_H_SIZE;
337 else
338 pktsz = pktmax;
339 skb = tipc_buf_acquire(pktsz, GFP_KERNEL);
340 if (!skb) {
341 rc = -ENOMEM;
342 goto error;
343 }
344 skb_orphan(skb);
345 __skb_queue_tail(list, skb);
346 msg_set_type(&pkthdr, FRAGMENT);
347 msg_set_size(&pkthdr, pktsz);
348 msg_set_fragm_no(&pkthdr, ++pktno);
349 skb_copy_to_linear_data(skb, &pkthdr, INT_H_SIZE);
350 pktpos = skb->data + INT_H_SIZE;
351 pktrem = pktsz - INT_H_SIZE;
352
353 } while (1);
354 msg_set_type(buf_msg(skb), LAST_FRAGMENT);
355 return dsz;
356error:
357 __skb_queue_purge(list);
358 __skb_queue_head_init(list);
359 return rc;
360}
361
362/**
363 * tipc_msg_bundle(): Append contents of a buffer to tail of an existing one
364 * @skb: the buffer to append to ("bundle")
365 * @msg: message to be appended
366 * @mtu: max allowable size for the bundle buffer
367 * Consumes buffer if successful
368 * Returns true if bundling could be performed, otherwise false
369 */
370bool tipc_msg_bundle(struct sk_buff *skb, struct tipc_msg *msg, u32 mtu)
371{
372 struct tipc_msg *bmsg;
373 unsigned int bsz;
374 unsigned int msz = msg_size(msg);
375 u32 start, pad;
376 u32 max = mtu - INT_H_SIZE;
377
378 if (likely(msg_user(msg) == MSG_FRAGMENTER))
379 return false;
380 if (!skb)
381 return false;
382 bmsg = buf_msg(skb);
383 bsz = msg_size(bmsg);
384 start = align(bsz);
385 pad = start - bsz;
386
387 if (unlikely(msg_user(msg) == TUNNEL_PROTOCOL))
388 return false;
389 if (unlikely(msg_user(msg) == BCAST_PROTOCOL))
390 return false;
391 if (unlikely(msg_user(bmsg) != MSG_BUNDLER))
392 return false;
393 if (unlikely(skb_tailroom(skb) < (pad + msz)))
394 return false;
395 if (unlikely(max < (start + msz)))
396 return false;
397 if ((msg_importance(msg) < TIPC_SYSTEM_IMPORTANCE) &&
398 (msg_importance(bmsg) == TIPC_SYSTEM_IMPORTANCE))
399 return false;
400
401 skb_put(skb, pad + msz);
402 skb_copy_to_linear_data_offset(skb, start, msg, msz);
403 msg_set_size(bmsg, start + msz);
404 msg_set_msgcnt(bmsg, msg_msgcnt(bmsg) + 1);
405 return true;
406}
407
408/**
409 * tipc_msg_extract(): extract bundled inner packet from buffer
410 * @skb: buffer to be extracted from.
411 * @iskb: extracted inner buffer, to be returned
412 * @pos: position in outer message of msg to be extracted.
413 * Returns position of next msg
414 * Consumes outer buffer when last packet extracted
415 * Returns true when when there is an extracted buffer, otherwise false
416 */
417bool tipc_msg_extract(struct sk_buff *skb, struct sk_buff **iskb, int *pos)
418{
419 struct tipc_msg *msg;
420 int imsz, offset;
421
422 *iskb = NULL;
423 if (unlikely(skb_linearize(skb)))
424 goto none;
425
426 msg = buf_msg(skb);
427 offset = msg_hdr_sz(msg) + *pos;
428 if (unlikely(offset > (msg_size(msg) - MIN_H_SIZE)))
429 goto none;
430
431 *iskb = skb_clone(skb, GFP_ATOMIC);
432 if (unlikely(!*iskb))
433 goto none;
434 skb_pull(*iskb, offset);
435 imsz = msg_size(buf_msg(*iskb));
436 skb_trim(*iskb, imsz);
437 if (unlikely(!tipc_msg_validate(iskb)))
438 goto none;
439 *pos += align(imsz);
440 return true;
441none:
442 kfree_skb(skb);
443 kfree_skb(*iskb);
444 *iskb = NULL;
445 return false;
446}
447
448/**
449 * tipc_msg_make_bundle(): Create bundle buf and append message to its tail
450 * @list: the buffer chain, where head is the buffer to replace/append
451 * @skb: buffer to be created, appended to and returned in case of success
452 * @msg: message to be appended
453 * @mtu: max allowable size for the bundle buffer, inclusive header
454 * @dnode: destination node for message. (Not always present in header)
455 * Returns true if success, otherwise false
456 */
457bool tipc_msg_make_bundle(struct sk_buff **skb, struct tipc_msg *msg,
458 u32 mtu, u32 dnode)
459{
460 struct sk_buff *_skb;
461 struct tipc_msg *bmsg;
462 u32 msz = msg_size(msg);
463 u32 max = mtu - INT_H_SIZE;
464
465 if (msg_user(msg) == MSG_FRAGMENTER)
466 return false;
467 if (msg_user(msg) == TUNNEL_PROTOCOL)
468 return false;
469 if (msg_user(msg) == BCAST_PROTOCOL)
470 return false;
471 if (msz > (max / 2))
472 return false;
473
474 _skb = tipc_buf_acquire(max, GFP_ATOMIC);
475 if (!_skb)
476 return false;
477
478 skb_trim(_skb, INT_H_SIZE);
479 bmsg = buf_msg(_skb);
480 tipc_msg_init(msg_prevnode(msg), bmsg, MSG_BUNDLER, 0,
481 INT_H_SIZE, dnode);
482 if (msg_isdata(msg))
483 msg_set_importance(bmsg, TIPC_CRITICAL_IMPORTANCE);
484 else
485 msg_set_importance(bmsg, TIPC_SYSTEM_IMPORTANCE);
486 msg_set_seqno(bmsg, msg_seqno(msg));
487 msg_set_ack(bmsg, msg_ack(msg));
488 msg_set_bcast_ack(bmsg, msg_bcast_ack(msg));
489 tipc_msg_bundle(_skb, msg, mtu);
490 *skb = _skb;
491 return true;
492}
493
494/**
495 * tipc_msg_reverse(): swap source and destination addresses and add error code
496 * @own_node: originating node id for reversed message
497 * @skb: buffer containing message to be reversed; may be replaced.
498 * @err: error code to be set in message, if any
499 * Consumes buffer at failure
500 * Returns true if success, otherwise false
501 */
502bool tipc_msg_reverse(u32 own_node, struct sk_buff **skb, int err)
503{
504 struct sk_buff *_skb = *skb;
505 struct tipc_msg *hdr;
506 struct tipc_msg ohdr;
507 int dlen;
508
509 if (skb_linearize(_skb))
510 goto exit;
511 hdr = buf_msg(_skb);
512 dlen = min_t(uint, msg_data_sz(hdr), MAX_FORWARD_SIZE);
513 if (msg_dest_droppable(hdr))
514 goto exit;
515 if (msg_errcode(hdr))
516 goto exit;
517
518 /* Take a copy of original header before altering message */
519 memcpy(&ohdr, hdr, msg_hdr_sz(hdr));
520
521 /* Never return SHORT header; expand by replacing buffer if necessary */
522 if (msg_short(hdr)) {
523 *skb = tipc_buf_acquire(BASIC_H_SIZE + dlen, GFP_ATOMIC);
524 if (!*skb)
525 goto exit;
526 memcpy((*skb)->data + BASIC_H_SIZE, msg_data(hdr), dlen);
527 kfree_skb(_skb);
528 _skb = *skb;
529 hdr = buf_msg(_skb);
530 memcpy(hdr, &ohdr, BASIC_H_SIZE);
531 msg_set_hdr_sz(hdr, BASIC_H_SIZE);
532 }
533
534 if (skb_cloned(_skb) &&
535 pskb_expand_head(_skb, BUF_HEADROOM, BUF_TAILROOM, GFP_ATOMIC))
536 goto exit;
537
538 /* reassign after skb header modifications */
539 hdr = buf_msg(_skb);
540 /* Now reverse the concerned fields */
541 msg_set_errcode(hdr, err);
542 msg_set_non_seq(hdr, 0);
543 msg_set_origport(hdr, msg_destport(&ohdr));
544 msg_set_destport(hdr, msg_origport(&ohdr));
545 msg_set_destnode(hdr, msg_prevnode(&ohdr));
546 msg_set_prevnode(hdr, own_node);
547 msg_set_orignode(hdr, own_node);
548 msg_set_size(hdr, msg_hdr_sz(hdr) + dlen);
549 skb_trim(_skb, msg_size(hdr));
550 skb_orphan(_skb);
551 return true;
552exit:
553 kfree_skb(_skb);
554 *skb = NULL;
555 return false;
556}
557
558/**
559 * tipc_msg_lookup_dest(): try to find new destination for named message
560 * @skb: the buffer containing the message.
561 * @err: error code to be used by caller if lookup fails
562 * Does not consume buffer
563 * Returns true if a destination is found, false otherwise
564 */
565bool tipc_msg_lookup_dest(struct net *net, struct sk_buff *skb, int *err)
566{
567 struct tipc_msg *msg = buf_msg(skb);
568 u32 dport, dnode;
569 u32 onode = tipc_own_addr(net);
570
571 if (!msg_isdata(msg))
572 return false;
573 if (!msg_named(msg))
574 return false;
575 if (msg_errcode(msg))
576 return false;
577 *err = TIPC_ERR_NO_NAME;
578 if (skb_linearize(skb))
579 return false;
580 msg = buf_msg(skb);
581 if (msg_reroute_cnt(msg))
582 return false;
583 dnode = tipc_scope2node(net, msg_lookup_scope(msg));
584 dport = tipc_nametbl_translate(net, msg_nametype(msg),
585 msg_nameinst(msg), &dnode);
586 if (!dport)
587 return false;
588 msg_incr_reroute_cnt(msg);
589 if (dnode != onode)
590 msg_set_prevnode(msg, onode);
591 msg_set_destnode(msg, dnode);
592 msg_set_destport(msg, dport);
593 *err = TIPC_OK;
594
595 if (!skb_cloned(skb))
596 return true;
597
598 /* Unclone buffer in case it was bundled */
599 if (pskb_expand_head(skb, BUF_HEADROOM, BUF_TAILROOM, GFP_ATOMIC))
600 return false;
601
602 return true;
603}
604
605/* tipc_msg_assemble() - assemble chain of fragments into one message
606 */
607bool tipc_msg_assemble(struct sk_buff_head *list)
608{
609 struct sk_buff *skb, *tmp = NULL;
610
611 if (skb_queue_len(list) == 1)
612 return true;
613
614 while ((skb = __skb_dequeue(list))) {
615 skb->next = NULL;
616 if (tipc_buf_append(&tmp, &skb)) {
617 __skb_queue_tail(list, skb);
618 return true;
619 }
620 if (!tmp)
621 break;
622 }
623 __skb_queue_purge(list);
624 __skb_queue_head_init(list);
625 pr_warn("Failed do assemble buffer\n");
626 return false;
627}
628
629/* tipc_msg_reassemble() - clone a buffer chain of fragments and
630 * reassemble the clones into one message
631 */
632bool tipc_msg_reassemble(struct sk_buff_head *list, struct sk_buff_head *rcvq)
633{
634 struct sk_buff *skb, *_skb;
635 struct sk_buff *frag = NULL;
636 struct sk_buff *head = NULL;
637 int hdr_len;
638
639 /* Copy header if single buffer */
640 if (skb_queue_len(list) == 1) {
641 skb = skb_peek(list);
642 hdr_len = skb_headroom(skb) + msg_hdr_sz(buf_msg(skb));
643 _skb = __pskb_copy(skb, hdr_len, GFP_ATOMIC);
644 if (!_skb)
645 return false;
646 __skb_queue_tail(rcvq, _skb);
647 return true;
648 }
649
650 /* Clone all fragments and reassemble */
651 skb_queue_walk(list, skb) {
652 frag = skb_clone(skb, GFP_ATOMIC);
653 if (!frag)
654 goto error;
655 frag->next = NULL;
656 if (tipc_buf_append(&head, &frag))
657 break;
658 if (!head)
659 goto error;
660 }
661 __skb_queue_tail(rcvq, frag);
662 return true;
663error:
664 pr_warn("Failed do clone local mcast rcv buffer\n");
665 kfree_skb(head);
666 return false;
667}
668
669bool tipc_msg_pskb_copy(u32 dst, struct sk_buff_head *msg,
670 struct sk_buff_head *cpy)
671{
672 struct sk_buff *skb, *_skb;
673
674 skb_queue_walk(msg, skb) {
675 _skb = pskb_copy(skb, GFP_ATOMIC);
676 if (!_skb) {
677 __skb_queue_purge(cpy);
678 return false;
679 }
680 msg_set_destnode(buf_msg(_skb), dst);
681 __skb_queue_tail(cpy, _skb);
682 }
683 return true;
684}
685
686/* tipc_skb_queue_sorted(); sort pkt into list according to sequence number
687 * @list: list to be appended to
688 * @seqno: sequence number of buffer to add
689 * @skb: buffer to add
690 */
691void __tipc_skb_queue_sorted(struct sk_buff_head *list, u16 seqno,
692 struct sk_buff *skb)
693{
694 struct sk_buff *_skb, *tmp;
695
696 if (skb_queue_empty(list) || less(seqno, buf_seqno(skb_peek(list)))) {
697 __skb_queue_head(list, skb);
698 return;
699 }
700
701 if (more(seqno, buf_seqno(skb_peek_tail(list)))) {
702 __skb_queue_tail(list, skb);
703 return;
704 }
705
706 skb_queue_walk_safe(list, _skb, tmp) {
707 if (more(seqno, buf_seqno(_skb)))
708 continue;
709 if (seqno == buf_seqno(_skb))
710 break;
711 __skb_queue_before(list, _skb, skb);
712 return;
713 }
714 kfree_skb(skb);
715}
716
717void tipc_skb_reject(struct net *net, int err, struct sk_buff *skb,
718 struct sk_buff_head *xmitq)
719{
720 if (tipc_msg_reverse(tipc_own_addr(net), &skb, err))
721 __skb_queue_tail(xmitq, skb);
722}