Commit | Line | Data |
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b97bf3fd PL |
1 | /* |
2 | * net/tipc/msg.c: TIPC message header routines | |
c4307285 | 3 | * |
37e22164 | 4 | * Copyright (c) 2000-2006, 2014, Ericsson AB |
741de3e9 | 5 | * Copyright (c) 2005, 2010-2011, Wind River Systems |
b97bf3fd PL |
6 | * All rights reserved. |
7 | * | |
9ea1fd3c | 8 | * Redistribution and use in source and binary forms, with or without |
b97bf3fd PL |
9 | * modification, are permitted provided that the following conditions are met: |
10 | * | |
9ea1fd3c PL |
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. | |
b97bf3fd | 19 | * |
9ea1fd3c PL |
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 | |
b97bf3fd PL |
34 | * POSSIBILITY OF SUCH DAMAGE. |
35 | */ | |
36 | ||
c93d3baa | 37 | #include <net/sock.h> |
b97bf3fd | 38 | #include "core.h" |
b97bf3fd | 39 | #include "msg.h" |
5a379074 JPM |
40 | #include "addr.h" |
41 | #include "name_table.h" | |
b97bf3fd | 42 | |
8db1bae3 JPM |
43 | #define MAX_FORWARD_SIZE 1024 |
44 | ||
4f1688b2 | 45 | static unsigned int align(unsigned int i) |
23461e83 | 46 | { |
4f1688b2 | 47 | return (i + 3) & ~3u; |
23461e83 AS |
48 | } |
49 | ||
859fc7c0 YX |
50 | /** |
51 | * tipc_buf_acquire - creates a TIPC message buffer | |
52 | * @size: message size (including TIPC header) | |
53 | * | |
54 | * Returns a new buffer with data pointers set to the specified size. | |
55 | * | |
56 | * NOTE: Headroom is reserved to allow prepending of a data link header. | |
57 | * There may also be unrequested tailroom present at the buffer's end. | |
58 | */ | |
59 | struct sk_buff *tipc_buf_acquire(u32 size) | |
60 | { | |
61 | struct sk_buff *skb; | |
62 | unsigned int buf_size = (BUF_HEADROOM + size + 3) & ~3u; | |
63 | ||
64 | skb = alloc_skb_fclone(buf_size, GFP_ATOMIC); | |
65 | if (skb) { | |
66 | skb_reserve(skb, BUF_HEADROOM); | |
67 | skb_put(skb, size); | |
68 | skb->next = NULL; | |
69 | } | |
70 | return skb; | |
71 | } | |
72 | ||
c5898636 JPM |
73 | void tipc_msg_init(u32 own_node, struct tipc_msg *m, u32 user, u32 type, |
74 | u32 hsize, u32 dnode) | |
23461e83 AS |
75 | { |
76 | memset(m, 0, hsize); | |
77 | msg_set_version(m); | |
78 | msg_set_user(m, user); | |
79 | msg_set_hdr_sz(m, hsize); | |
80 | msg_set_size(m, hsize); | |
c5898636 | 81 | msg_set_prevnode(m, own_node); |
23461e83 | 82 | msg_set_type(m, type); |
1dd0bd2b | 83 | if (hsize > SHORT_H_SIZE) { |
c5898636 JPM |
84 | msg_set_orignode(m, own_node); |
85 | msg_set_destnode(m, dnode); | |
1dd0bd2b JPM |
86 | } |
87 | } | |
88 | ||
c5898636 | 89 | struct sk_buff *tipc_msg_create(uint user, uint type, |
34747539 YX |
90 | uint hdr_sz, uint data_sz, u32 dnode, |
91 | u32 onode, u32 dport, u32 oport, int errcode) | |
1dd0bd2b JPM |
92 | { |
93 | struct tipc_msg *msg; | |
94 | struct sk_buff *buf; | |
95 | ||
96 | buf = tipc_buf_acquire(hdr_sz + data_sz); | |
97 | if (unlikely(!buf)) | |
98 | return NULL; | |
99 | ||
100 | msg = buf_msg(buf); | |
c5898636 | 101 | tipc_msg_init(onode, msg, user, type, hdr_sz, dnode); |
1dd0bd2b | 102 | msg_set_size(msg, hdr_sz + data_sz); |
1dd0bd2b JPM |
103 | msg_set_origport(msg, oport); |
104 | msg_set_destport(msg, dport); | |
105 | msg_set_errcode(msg, errcode); | |
106 | if (hdr_sz > SHORT_H_SIZE) { | |
107 | msg_set_orignode(msg, onode); | |
108 | msg_set_destnode(msg, dnode); | |
109 | } | |
110 | return buf; | |
23461e83 AS |
111 | } |
112 | ||
37e22164 | 113 | /* tipc_buf_append(): Append a buffer to the fragment list of another buffer |
29322d0d JPM |
114 | * @*headbuf: in: NULL for first frag, otherwise value returned from prev call |
115 | * out: set when successful non-complete reassembly, otherwise NULL | |
116 | * @*buf: in: the buffer to append. Always defined | |
b2ad5e5f | 117 | * out: head buf after successful complete reassembly, otherwise NULL |
29322d0d | 118 | * Returns 1 when reassembly complete, otherwise 0 |
37e22164 JPM |
119 | */ |
120 | int tipc_buf_append(struct sk_buff **headbuf, struct sk_buff **buf) | |
121 | { | |
122 | struct sk_buff *head = *headbuf; | |
123 | struct sk_buff *frag = *buf; | |
124 | struct sk_buff *tail; | |
13e9b997 JPM |
125 | struct tipc_msg *msg; |
126 | u32 fragid; | |
37e22164 | 127 | int delta; |
13e9b997 | 128 | bool headstolen; |
37e22164 | 129 | |
13e9b997 JPM |
130 | if (!frag) |
131 | goto err; | |
132 | ||
133 | msg = buf_msg(frag); | |
134 | fragid = msg_type(msg); | |
135 | frag->next = NULL; | |
37e22164 JPM |
136 | skb_pull(frag, msg_hdr_sz(msg)); |
137 | ||
138 | if (fragid == FIRST_FRAGMENT) { | |
13e9b997 JPM |
139 | if (unlikely(head)) |
140 | goto err; | |
141 | if (unlikely(skb_unclone(frag, GFP_ATOMIC))) | |
142 | goto err; | |
37e22164 JPM |
143 | head = *headbuf = frag; |
144 | skb_frag_list_init(head); | |
13e9b997 | 145 | TIPC_SKB_CB(head)->tail = NULL; |
29322d0d | 146 | *buf = NULL; |
37e22164 JPM |
147 | return 0; |
148 | } | |
13e9b997 | 149 | |
37e22164 | 150 | if (!head) |
13e9b997 JPM |
151 | goto err; |
152 | ||
37e22164 JPM |
153 | if (skb_try_coalesce(head, frag, &headstolen, &delta)) { |
154 | kfree_skb_partial(frag, headstolen); | |
155 | } else { | |
13e9b997 | 156 | tail = TIPC_SKB_CB(head)->tail; |
37e22164 JPM |
157 | if (!skb_has_frag_list(head)) |
158 | skb_shinfo(head)->frag_list = frag; | |
159 | else | |
160 | tail->next = frag; | |
161 | head->truesize += frag->truesize; | |
162 | head->data_len += frag->len; | |
163 | head->len += frag->len; | |
164 | TIPC_SKB_CB(head)->tail = frag; | |
165 | } | |
13e9b997 | 166 | |
37e22164 JPM |
167 | if (fragid == LAST_FRAGMENT) { |
168 | *buf = head; | |
169 | TIPC_SKB_CB(head)->tail = NULL; | |
170 | *headbuf = NULL; | |
171 | return 1; | |
172 | } | |
173 | *buf = NULL; | |
174 | return 0; | |
13e9b997 JPM |
175 | |
176 | err: | |
37e22164 JPM |
177 | pr_warn_ratelimited("Unable to build fragment list\n"); |
178 | kfree_skb(*buf); | |
29322d0d JPM |
179 | kfree_skb(*headbuf); |
180 | *buf = *headbuf = NULL; | |
37e22164 JPM |
181 | return 0; |
182 | } | |
4f1688b2 | 183 | |
067608e9 JPM |
184 | |
185 | /** | |
9fbfb8b1 | 186 | * tipc_msg_build - create buffer chain containing specified header and data |
067608e9 | 187 | * @mhdr: Message header, to be prepended to data |
45dcc687 | 188 | * @m: User message |
067608e9 JPM |
189 | * @dsz: Total length of user data |
190 | * @pktmax: Max packet size that can be used | |
a6ca1094 YX |
191 | * @list: Buffer or chain of buffers to be returned to caller |
192 | * | |
067608e9 JPM |
193 | * Returns message data size or errno: -ENOMEM, -EFAULT |
194 | */ | |
c5898636 | 195 | int tipc_msg_build(struct tipc_msg *mhdr, struct msghdr *m, |
34747539 | 196 | int offset, int dsz, int pktmax, struct sk_buff_head *list) |
067608e9 JPM |
197 | { |
198 | int mhsz = msg_hdr_sz(mhdr); | |
199 | int msz = mhsz + dsz; | |
200 | int pktno = 1; | |
201 | int pktsz; | |
202 | int pktrem = pktmax; | |
203 | int drem = dsz; | |
204 | struct tipc_msg pkthdr; | |
a6ca1094 | 205 | struct sk_buff *skb; |
067608e9 JPM |
206 | char *pktpos; |
207 | int rc; | |
a6ca1094 | 208 | |
067608e9 JPM |
209 | msg_set_size(mhdr, msz); |
210 | ||
211 | /* No fragmentation needed? */ | |
212 | if (likely(msz <= pktmax)) { | |
a6ca1094 YX |
213 | skb = tipc_buf_acquire(msz); |
214 | if (unlikely(!skb)) | |
067608e9 | 215 | return -ENOMEM; |
c93d3baa | 216 | skb_orphan(skb); |
a6ca1094 YX |
217 | __skb_queue_tail(list, skb); |
218 | skb_copy_to_linear_data(skb, mhdr, mhsz); | |
219 | pktpos = skb->data + mhsz; | |
f25dcc76 | 220 | if (copy_from_iter(pktpos, dsz, &m->msg_iter) == dsz) |
067608e9 JPM |
221 | return dsz; |
222 | rc = -EFAULT; | |
223 | goto error; | |
224 | } | |
225 | ||
226 | /* Prepare reusable fragment header */ | |
c5898636 JPM |
227 | tipc_msg_init(msg_prevnode(mhdr), &pkthdr, MSG_FRAGMENTER, |
228 | FIRST_FRAGMENT, INT_H_SIZE, msg_destnode(mhdr)); | |
067608e9 JPM |
229 | msg_set_size(&pkthdr, pktmax); |
230 | msg_set_fragm_no(&pkthdr, pktno); | |
231 | ||
232 | /* Prepare first fragment */ | |
a6ca1094 YX |
233 | skb = tipc_buf_acquire(pktmax); |
234 | if (!skb) | |
067608e9 | 235 | return -ENOMEM; |
c93d3baa | 236 | skb_orphan(skb); |
a6ca1094 YX |
237 | __skb_queue_tail(list, skb); |
238 | pktpos = skb->data; | |
239 | skb_copy_to_linear_data(skb, &pkthdr, INT_H_SIZE); | |
067608e9 JPM |
240 | pktpos += INT_H_SIZE; |
241 | pktrem -= INT_H_SIZE; | |
a6ca1094 | 242 | skb_copy_to_linear_data_offset(skb, INT_H_SIZE, mhdr, mhsz); |
067608e9 JPM |
243 | pktpos += mhsz; |
244 | pktrem -= mhsz; | |
245 | ||
246 | do { | |
247 | if (drem < pktrem) | |
248 | pktrem = drem; | |
249 | ||
f25dcc76 | 250 | if (copy_from_iter(pktpos, pktrem, &m->msg_iter) != pktrem) { |
067608e9 JPM |
251 | rc = -EFAULT; |
252 | goto error; | |
253 | } | |
254 | drem -= pktrem; | |
067608e9 JPM |
255 | |
256 | if (!drem) | |
257 | break; | |
258 | ||
259 | /* Prepare new fragment: */ | |
260 | if (drem < (pktmax - INT_H_SIZE)) | |
261 | pktsz = drem + INT_H_SIZE; | |
262 | else | |
263 | pktsz = pktmax; | |
a6ca1094 YX |
264 | skb = tipc_buf_acquire(pktsz); |
265 | if (!skb) { | |
067608e9 JPM |
266 | rc = -ENOMEM; |
267 | goto error; | |
268 | } | |
c93d3baa | 269 | skb_orphan(skb); |
a6ca1094 | 270 | __skb_queue_tail(list, skb); |
067608e9 JPM |
271 | msg_set_type(&pkthdr, FRAGMENT); |
272 | msg_set_size(&pkthdr, pktsz); | |
273 | msg_set_fragm_no(&pkthdr, ++pktno); | |
a6ca1094 YX |
274 | skb_copy_to_linear_data(skb, &pkthdr, INT_H_SIZE); |
275 | pktpos = skb->data + INT_H_SIZE; | |
067608e9 JPM |
276 | pktrem = pktsz - INT_H_SIZE; |
277 | ||
278 | } while (1); | |
a6ca1094 | 279 | msg_set_type(buf_msg(skb), LAST_FRAGMENT); |
067608e9 JPM |
280 | return dsz; |
281 | error: | |
a6ca1094 YX |
282 | __skb_queue_purge(list); |
283 | __skb_queue_head_init(list); | |
067608e9 JPM |
284 | return rc; |
285 | } | |
286 | ||
4f1688b2 JPM |
287 | /** |
288 | * tipc_msg_bundle(): Append contents of a buffer to tail of an existing one | |
58dc55f2 YX |
289 | * @list: the buffer chain of the existing buffer ("bundle") |
290 | * @skb: buffer to be appended | |
4f1688b2 JPM |
291 | * @mtu: max allowable size for the bundle buffer |
292 | * Consumes buffer if successful | |
293 | * Returns true if bundling could be performed, otherwise false | |
294 | */ | |
58dc55f2 | 295 | bool tipc_msg_bundle(struct sk_buff_head *list, struct sk_buff *skb, u32 mtu) |
4f1688b2 | 296 | { |
58dc55f2 YX |
297 | struct sk_buff *bskb = skb_peek_tail(list); |
298 | struct tipc_msg *bmsg = buf_msg(bskb); | |
299 | struct tipc_msg *msg = buf_msg(skb); | |
4f1688b2 JPM |
300 | unsigned int bsz = msg_size(bmsg); |
301 | unsigned int msz = msg_size(msg); | |
302 | u32 start = align(bsz); | |
303 | u32 max = mtu - INT_H_SIZE; | |
304 | u32 pad = start - bsz; | |
305 | ||
306 | if (likely(msg_user(msg) == MSG_FRAGMENTER)) | |
307 | return false; | |
308 | if (unlikely(msg_user(msg) == CHANGEOVER_PROTOCOL)) | |
309 | return false; | |
310 | if (unlikely(msg_user(msg) == BCAST_PROTOCOL)) | |
311 | return false; | |
312 | if (likely(msg_user(bmsg) != MSG_BUNDLER)) | |
313 | return false; | |
58dc55f2 | 314 | if (likely(!TIPC_SKB_CB(bskb)->bundling)) |
4f1688b2 | 315 | return false; |
58dc55f2 | 316 | if (unlikely(skb_tailroom(bskb) < (pad + msz))) |
4f1688b2 JPM |
317 | return false; |
318 | if (unlikely(max < (start + msz))) | |
319 | return false; | |
320 | ||
58dc55f2 YX |
321 | skb_put(bskb, pad + msz); |
322 | skb_copy_to_linear_data_offset(bskb, start, skb->data, msz); | |
4f1688b2 JPM |
323 | msg_set_size(bmsg, start + msz); |
324 | msg_set_msgcnt(bmsg, msg_msgcnt(bmsg) + 1); | |
58dc55f2 | 325 | kfree_skb(skb); |
4f1688b2 JPM |
326 | return true; |
327 | } | |
328 | ||
329 | /** | |
330 | * tipc_msg_make_bundle(): Create bundle buf and append message to its tail | |
58dc55f2 YX |
331 | * @list: the buffer chain |
332 | * @skb: buffer to be appended and replaced | |
333 | * @mtu: max allowable size for the bundle buffer, inclusive header | |
4f1688b2 JPM |
334 | * @dnode: destination node for message. (Not always present in header) |
335 | * Replaces buffer if successful | |
b2ad5e5f | 336 | * Returns true if success, otherwise false |
4f1688b2 | 337 | */ |
c5898636 | 338 | bool tipc_msg_make_bundle(struct sk_buff_head *list, |
34747539 | 339 | struct sk_buff *skb, u32 mtu, u32 dnode) |
4f1688b2 | 340 | { |
58dc55f2 | 341 | struct sk_buff *bskb; |
4f1688b2 | 342 | struct tipc_msg *bmsg; |
58dc55f2 | 343 | struct tipc_msg *msg = buf_msg(skb); |
4f1688b2 JPM |
344 | u32 msz = msg_size(msg); |
345 | u32 max = mtu - INT_H_SIZE; | |
346 | ||
347 | if (msg_user(msg) == MSG_FRAGMENTER) | |
348 | return false; | |
349 | if (msg_user(msg) == CHANGEOVER_PROTOCOL) | |
350 | return false; | |
351 | if (msg_user(msg) == BCAST_PROTOCOL) | |
352 | return false; | |
353 | if (msz > (max / 2)) | |
354 | return false; | |
355 | ||
58dc55f2 YX |
356 | bskb = tipc_buf_acquire(max); |
357 | if (!bskb) | |
4f1688b2 JPM |
358 | return false; |
359 | ||
58dc55f2 YX |
360 | skb_trim(bskb, INT_H_SIZE); |
361 | bmsg = buf_msg(bskb); | |
c5898636 JPM |
362 | tipc_msg_init(msg_prevnode(msg), bmsg, MSG_BUNDLER, 0, |
363 | INT_H_SIZE, dnode); | |
4f1688b2 JPM |
364 | msg_set_seqno(bmsg, msg_seqno(msg)); |
365 | msg_set_ack(bmsg, msg_ack(msg)); | |
366 | msg_set_bcast_ack(bmsg, msg_bcast_ack(msg)); | |
58dc55f2 YX |
367 | TIPC_SKB_CB(bskb)->bundling = true; |
368 | __skb_queue_tail(list, bskb); | |
369 | return tipc_msg_bundle(list, skb, mtu); | |
4f1688b2 | 370 | } |
8db1bae3 JPM |
371 | |
372 | /** | |
373 | * tipc_msg_reverse(): swap source and destination addresses and add error code | |
374 | * @buf: buffer containing message to be reversed | |
375 | * @dnode: return value: node where to send message after reversal | |
376 | * @err: error code to be set in message | |
377 | * Consumes buffer if failure | |
378 | * Returns true if success, otherwise false | |
379 | */ | |
c5898636 | 380 | bool tipc_msg_reverse(u32 own_addr, struct sk_buff *buf, u32 *dnode, |
34747539 | 381 | int err) |
8db1bae3 JPM |
382 | { |
383 | struct tipc_msg *msg = buf_msg(buf); | |
384 | uint imp = msg_importance(msg); | |
385 | struct tipc_msg ohdr; | |
386 | uint rdsz = min_t(uint, msg_data_sz(msg), MAX_FORWARD_SIZE); | |
387 | ||
ac0074ee | 388 | if (skb_linearize(buf)) |
8db1bae3 | 389 | goto exit; |
ac0074ee JPM |
390 | if (msg_dest_droppable(msg)) |
391 | goto exit; | |
392 | if (msg_errcode(msg)) | |
8db1bae3 JPM |
393 | goto exit; |
394 | ||
395 | memcpy(&ohdr, msg, msg_hdr_sz(msg)); | |
ac0074ee JPM |
396 | imp = min_t(uint, imp + 1, TIPC_CRITICAL_IMPORTANCE); |
397 | if (msg_isdata(msg)) | |
398 | msg_set_importance(msg, imp); | |
8db1bae3 JPM |
399 | msg_set_errcode(msg, err); |
400 | msg_set_origport(msg, msg_destport(&ohdr)); | |
401 | msg_set_destport(msg, msg_origport(&ohdr)); | |
c5898636 | 402 | msg_set_prevnode(msg, own_addr); |
8db1bae3 JPM |
403 | if (!msg_short(msg)) { |
404 | msg_set_orignode(msg, msg_destnode(&ohdr)); | |
405 | msg_set_destnode(msg, msg_orignode(&ohdr)); | |
406 | } | |
407 | msg_set_size(msg, msg_hdr_sz(msg) + rdsz); | |
408 | skb_trim(buf, msg_size(msg)); | |
409 | skb_orphan(buf); | |
410 | *dnode = msg_orignode(&ohdr); | |
411 | return true; | |
412 | exit: | |
413 | kfree_skb(buf); | |
e3a77561 | 414 | *dnode = 0; |
8db1bae3 JPM |
415 | return false; |
416 | } | |
5a379074 JPM |
417 | |
418 | /** | |
e3a77561 JPM |
419 | * tipc_msg_lookup_dest(): try to find new destination for named message |
420 | * @skb: the buffer containing the message. | |
421 | * @dnode: return value: next-hop node, if destination found | |
422 | * @err: return value: error code to use, if message to be rejected | |
5a379074 | 423 | * Does not consume buffer |
e3a77561 | 424 | * Returns true if a destination is found, false otherwise |
5a379074 | 425 | */ |
e3a77561 JPM |
426 | bool tipc_msg_lookup_dest(struct net *net, struct sk_buff *skb, |
427 | u32 *dnode, int *err) | |
5a379074 | 428 | { |
e3a77561 | 429 | struct tipc_msg *msg = buf_msg(skb); |
5a379074 JPM |
430 | u32 dport; |
431 | ||
e3a77561 JPM |
432 | if (!msg_isdata(msg)) |
433 | return false; | |
434 | if (!msg_named(msg)) | |
435 | return false; | |
436 | *err = -TIPC_ERR_NO_NAME; | |
437 | if (skb_linearize(skb)) | |
438 | return false; | |
5a379074 | 439 | if (msg_reroute_cnt(msg) > 0) |
e3a77561 | 440 | return false; |
34747539 | 441 | *dnode = addr_domain(net, msg_lookup_scope(msg)); |
4ac1c8d0 | 442 | dport = tipc_nametbl_translate(net, msg_nametype(msg), |
e3a77561 | 443 | msg_nameinst(msg), dnode); |
5a379074 | 444 | if (!dport) |
e3a77561 | 445 | return false; |
5a379074 JPM |
446 | msg_incr_reroute_cnt(msg); |
447 | msg_set_destnode(msg, *dnode); | |
448 | msg_set_destport(msg, dport); | |
e3a77561 JPM |
449 | *err = TIPC_OK; |
450 | return true; | |
5a379074 | 451 | } |
078bec82 JPM |
452 | |
453 | /* tipc_msg_reassemble() - clone a buffer chain of fragments and | |
454 | * reassemble the clones into one message | |
455 | */ | |
a6ca1094 | 456 | struct sk_buff *tipc_msg_reassemble(struct sk_buff_head *list) |
078bec82 | 457 | { |
a6ca1094 YX |
458 | struct sk_buff *skb; |
459 | struct sk_buff *frag = NULL; | |
078bec82 JPM |
460 | struct sk_buff *head = NULL; |
461 | int hdr_sz; | |
462 | ||
463 | /* Copy header if single buffer */ | |
a6ca1094 YX |
464 | if (skb_queue_len(list) == 1) { |
465 | skb = skb_peek(list); | |
466 | hdr_sz = skb_headroom(skb) + msg_hdr_sz(buf_msg(skb)); | |
467 | return __pskb_copy(skb, hdr_sz, GFP_ATOMIC); | |
078bec82 JPM |
468 | } |
469 | ||
470 | /* Clone all fragments and reassemble */ | |
a6ca1094 YX |
471 | skb_queue_walk(list, skb) { |
472 | frag = skb_clone(skb, GFP_ATOMIC); | |
078bec82 JPM |
473 | if (!frag) |
474 | goto error; | |
475 | frag->next = NULL; | |
476 | if (tipc_buf_append(&head, &frag)) | |
477 | break; | |
478 | if (!head) | |
479 | goto error; | |
078bec82 JPM |
480 | } |
481 | return frag; | |
482 | error: | |
483 | pr_warn("Failed do clone local mcast rcv buffer\n"); | |
484 | kfree_skb(head); | |
485 | return NULL; | |
486 | } |