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ac79cbb9 | 1 | /* Copyright (C) 2013-2017 B.A.T.M.A.N. contributors: |
610bfc6b MH |
2 | * |
3 | * Martin Hundebøll <martin@hundeboll.net> | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or | |
6 | * modify it under the terms of version 2 of the GNU General Public | |
7 | * License as published by the Free Software Foundation. | |
8 | * | |
9 | * This program is distributed in the hope that it will be useful, but | |
10 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
12 | * General Public License for more details. | |
13 | * | |
14 | * You should have received a copy of the GNU General Public License | |
ebf38fb7 | 15 | * along with this program; if not, see <http://www.gnu.org/licenses/>. |
610bfc6b MH |
16 | */ |
17 | ||
610bfc6b | 18 | #include "fragmentation.h" |
1e2c2a4f SE |
19 | #include "main.h" |
20 | ||
21 | #include <linux/atomic.h> | |
22 | #include <linux/byteorder/generic.h> | |
8def0be8 | 23 | #include <linux/errno.h> |
1e2c2a4f SE |
24 | #include <linux/etherdevice.h> |
25 | #include <linux/fs.h> | |
26 | #include <linux/if_ether.h> | |
27 | #include <linux/jiffies.h> | |
28 | #include <linux/kernel.h> | |
5274cd68 | 29 | #include <linux/lockdep.h> |
1e2c2a4f | 30 | #include <linux/netdevice.h> |
1e2c2a4f SE |
31 | #include <linux/skbuff.h> |
32 | #include <linux/slab.h> | |
33 | #include <linux/spinlock.h> | |
34 | #include <linux/string.h> | |
35 | ||
36 | #include "hard-interface.h" | |
610bfc6b | 37 | #include "originator.h" |
1e2c2a4f | 38 | #include "packet.h" |
610bfc6b | 39 | #include "routing.h" |
1e2c2a4f | 40 | #include "send.h" |
610bfc6b MH |
41 | #include "soft-interface.h" |
42 | ||
610bfc6b MH |
43 | /** |
44 | * batadv_frag_clear_chain - delete entries in the fragment buffer chain | |
45 | * @head: head of chain with entries. | |
bd687fe4 | 46 | * @dropped: whether the chain is cleared because all fragments are dropped |
610bfc6b MH |
47 | * |
48 | * Free fragments in the passed hlist. Should be called with appropriate lock. | |
49 | */ | |
bd687fe4 | 50 | static void batadv_frag_clear_chain(struct hlist_head *head, bool dropped) |
610bfc6b MH |
51 | { |
52 | struct batadv_frag_list_entry *entry; | |
53 | struct hlist_node *node; | |
54 | ||
55 | hlist_for_each_entry_safe(entry, node, head, list) { | |
56 | hlist_del(&entry->list); | |
bd687fe4 SE |
57 | |
58 | if (dropped) | |
59 | kfree_skb(entry->skb); | |
60 | else | |
61 | consume_skb(entry->skb); | |
62 | ||
610bfc6b MH |
63 | kfree(entry); |
64 | } | |
65 | } | |
66 | ||
67 | /** | |
68 | * batadv_frag_purge_orig - free fragments associated to an orig | |
69 | * @orig_node: originator to free fragments from | |
70 | * @check_cb: optional function to tell if an entry should be purged | |
71 | */ | |
72 | void batadv_frag_purge_orig(struct batadv_orig_node *orig_node, | |
73 | bool (*check_cb)(struct batadv_frag_table_entry *)) | |
74 | { | |
75 | struct batadv_frag_table_entry *chain; | |
6b5e971a | 76 | u8 i; |
610bfc6b MH |
77 | |
78 | for (i = 0; i < BATADV_FRAG_BUFFER_COUNT; i++) { | |
79 | chain = &orig_node->fragments[i]; | |
01f6b5c7 | 80 | spin_lock_bh(&chain->lock); |
610bfc6b MH |
81 | |
82 | if (!check_cb || check_cb(chain)) { | |
bd687fe4 | 83 | batadv_frag_clear_chain(&chain->fragment_list, true); |
01f6b5c7 | 84 | chain->size = 0; |
610bfc6b MH |
85 | } |
86 | ||
01f6b5c7 | 87 | spin_unlock_bh(&chain->lock); |
610bfc6b MH |
88 | } |
89 | } | |
90 | ||
91 | /** | |
92 | * batadv_frag_size_limit - maximum possible size of packet to be fragmented | |
93 | * | |
62fe710f | 94 | * Return: the maximum size of payload that can be fragmented. |
610bfc6b MH |
95 | */ |
96 | static int batadv_frag_size_limit(void) | |
97 | { | |
98 | int limit = BATADV_FRAG_MAX_FRAG_SIZE; | |
99 | ||
100 | limit -= sizeof(struct batadv_frag_packet); | |
101 | limit *= BATADV_FRAG_MAX_FRAGMENTS; | |
102 | ||
103 | return limit; | |
104 | } | |
105 | ||
106 | /** | |
107 | * batadv_frag_init_chain - check and prepare fragment chain for new fragment | |
108 | * @chain: chain in fragments table to init | |
109 | * @seqno: sequence number of the received fragment | |
110 | * | |
111 | * Make chain ready for a fragment with sequence number "seqno". Delete existing | |
112 | * entries if they have an "old" sequence number. | |
113 | * | |
114 | * Caller must hold chain->lock. | |
115 | * | |
62fe710f | 116 | * Return: true if chain is empty and caller can just insert the new fragment |
610bfc6b MH |
117 | * without searching for the right position. |
118 | */ | |
119 | static bool batadv_frag_init_chain(struct batadv_frag_table_entry *chain, | |
6b5e971a | 120 | u16 seqno) |
610bfc6b | 121 | { |
5274cd68 SE |
122 | lockdep_assert_held(&chain->lock); |
123 | ||
610bfc6b MH |
124 | if (chain->seqno == seqno) |
125 | return false; | |
126 | ||
176e5b77 | 127 | if (!hlist_empty(&chain->fragment_list)) |
bd687fe4 | 128 | batadv_frag_clear_chain(&chain->fragment_list, true); |
610bfc6b MH |
129 | |
130 | chain->size = 0; | |
131 | chain->seqno = seqno; | |
132 | ||
133 | return true; | |
134 | } | |
135 | ||
136 | /** | |
137 | * batadv_frag_insert_packet - insert a fragment into a fragment chain | |
138 | * @orig_node: originator that the fragment was received from | |
139 | * @skb: skb to insert | |
140 | * @chain_out: list head to attach complete chains of fragments to | |
141 | * | |
142 | * Insert a new fragment into the reverse ordered chain in the right table | |
143 | * entry. The hash table entry is cleared if "old" fragments exist in it. | |
144 | * | |
62fe710f | 145 | * Return: true if skb is buffered, false on error. If the chain has all the |
610bfc6b MH |
146 | * fragments needed to merge the packet, the chain is moved to the passed head |
147 | * to avoid locking the chain in the table. | |
148 | */ | |
149 | static bool batadv_frag_insert_packet(struct batadv_orig_node *orig_node, | |
150 | struct sk_buff *skb, | |
151 | struct hlist_head *chain_out) | |
152 | { | |
153 | struct batadv_frag_table_entry *chain; | |
154 | struct batadv_frag_list_entry *frag_entry_new = NULL, *frag_entry_curr; | |
d9124268 | 155 | struct batadv_frag_list_entry *frag_entry_last = NULL; |
610bfc6b | 156 | struct batadv_frag_packet *frag_packet; |
6b5e971a SE |
157 | u8 bucket; |
158 | u16 seqno, hdr_size = sizeof(struct batadv_frag_packet); | |
610bfc6b MH |
159 | bool ret = false; |
160 | ||
161 | /* Linearize packet to avoid linearizing 16 packets in a row when doing | |
162 | * the later merge. Non-linear merge should be added to remove this | |
163 | * linearization. | |
164 | */ | |
165 | if (skb_linearize(skb) < 0) | |
166 | goto err; | |
167 | ||
168 | frag_packet = (struct batadv_frag_packet *)skb->data; | |
169 | seqno = ntohs(frag_packet->seqno); | |
170 | bucket = seqno % BATADV_FRAG_BUFFER_COUNT; | |
171 | ||
172 | frag_entry_new = kmalloc(sizeof(*frag_entry_new), GFP_ATOMIC); | |
173 | if (!frag_entry_new) | |
174 | goto err; | |
175 | ||
176 | frag_entry_new->skb = skb; | |
177 | frag_entry_new->no = frag_packet->no; | |
178 | ||
179 | /* Select entry in the "chain table" and delete any prior fragments | |
180 | * with another sequence number. batadv_frag_init_chain() returns true, | |
181 | * if the list is empty at return. | |
182 | */ | |
183 | chain = &orig_node->fragments[bucket]; | |
184 | spin_lock_bh(&chain->lock); | |
185 | if (batadv_frag_init_chain(chain, seqno)) { | |
176e5b77 | 186 | hlist_add_head(&frag_entry_new->list, &chain->fragment_list); |
610bfc6b MH |
187 | chain->size = skb->len - hdr_size; |
188 | chain->timestamp = jiffies; | |
53e77145 | 189 | chain->total_size = ntohs(frag_packet->total_size); |
610bfc6b MH |
190 | ret = true; |
191 | goto out; | |
192 | } | |
193 | ||
194 | /* Find the position for the new fragment. */ | |
176e5b77 | 195 | hlist_for_each_entry(frag_entry_curr, &chain->fragment_list, list) { |
610bfc6b MH |
196 | /* Drop packet if fragment already exists. */ |
197 | if (frag_entry_curr->no == frag_entry_new->no) | |
198 | goto err_unlock; | |
199 | ||
200 | /* Order fragments from highest to lowest. */ | |
201 | if (frag_entry_curr->no < frag_entry_new->no) { | |
202 | hlist_add_before(&frag_entry_new->list, | |
203 | &frag_entry_curr->list); | |
204 | chain->size += skb->len - hdr_size; | |
205 | chain->timestamp = jiffies; | |
206 | ret = true; | |
207 | goto out; | |
208 | } | |
d9124268 SE |
209 | |
210 | /* store current entry because it could be the last in list */ | |
211 | frag_entry_last = frag_entry_curr; | |
610bfc6b MH |
212 | } |
213 | ||
d9124268 SE |
214 | /* Reached the end of the list, so insert after 'frag_entry_last'. */ |
215 | if (likely(frag_entry_last)) { | |
e050dbeb | 216 | hlist_add_behind(&frag_entry_new->list, &frag_entry_last->list); |
610bfc6b MH |
217 | chain->size += skb->len - hdr_size; |
218 | chain->timestamp = jiffies; | |
219 | ret = true; | |
220 | } | |
221 | ||
222 | out: | |
223 | if (chain->size > batadv_frag_size_limit() || | |
53e77145 SE |
224 | chain->total_size != ntohs(frag_packet->total_size) || |
225 | chain->total_size > batadv_frag_size_limit()) { | |
610bfc6b | 226 | /* Clear chain if total size of either the list or the packet |
53e77145 SE |
227 | * exceeds the maximum size of one merged packet. Don't allow |
228 | * packets to have different total_size. | |
610bfc6b | 229 | */ |
bd687fe4 | 230 | batadv_frag_clear_chain(&chain->fragment_list, true); |
610bfc6b MH |
231 | chain->size = 0; |
232 | } else if (ntohs(frag_packet->total_size) == chain->size) { | |
233 | /* All fragments received. Hand over chain to caller. */ | |
176e5b77 | 234 | hlist_move_list(&chain->fragment_list, chain_out); |
610bfc6b MH |
235 | chain->size = 0; |
236 | } | |
237 | ||
238 | err_unlock: | |
239 | spin_unlock_bh(&chain->lock); | |
240 | ||
241 | err: | |
248e23b5 | 242 | if (!ret) { |
610bfc6b | 243 | kfree(frag_entry_new); |
248e23b5 SE |
244 | kfree_skb(skb); |
245 | } | |
610bfc6b MH |
246 | |
247 | return ret; | |
248 | } | |
249 | ||
250 | /** | |
251 | * batadv_frag_merge_packets - merge a chain of fragments | |
252 | * @chain: head of chain with fragments | |
610bfc6b MH |
253 | * |
254 | * Expand the first skb in the chain and copy the content of the remaining | |
255 | * skb's into the expanded one. After doing so, clear the chain. | |
256 | * | |
62fe710f | 257 | * Return: the merged skb or NULL on error. |
610bfc6b MH |
258 | */ |
259 | static struct sk_buff * | |
83e8b877 | 260 | batadv_frag_merge_packets(struct hlist_head *chain) |
610bfc6b MH |
261 | { |
262 | struct batadv_frag_packet *packet; | |
263 | struct batadv_frag_list_entry *entry; | |
422d2f77 | 264 | struct sk_buff *skb_out; |
610bfc6b | 265 | int size, hdr_size = sizeof(struct batadv_frag_packet); |
bd687fe4 | 266 | bool dropped = false; |
610bfc6b | 267 | |
610bfc6b MH |
268 | /* Remove first entry, as this is the destination for the rest of the |
269 | * fragments. | |
270 | */ | |
271 | entry = hlist_entry(chain->first, struct batadv_frag_list_entry, list); | |
272 | hlist_del(&entry->list); | |
273 | skb_out = entry->skb; | |
274 | kfree(entry); | |
275 | ||
83e8b877 SE |
276 | packet = (struct batadv_frag_packet *)skb_out->data; |
277 | size = ntohs(packet->total_size); | |
278 | ||
610bfc6b | 279 | /* Make room for the rest of the fragments. */ |
5b6698b0 | 280 | if (pskb_expand_head(skb_out, 0, size - skb_out->len, GFP_ATOMIC) < 0) { |
610bfc6b MH |
281 | kfree_skb(skb_out); |
282 | skb_out = NULL; | |
bd687fe4 | 283 | dropped = true; |
610bfc6b MH |
284 | goto free; |
285 | } | |
286 | ||
287 | /* Move the existing MAC header to just before the payload. (Override | |
288 | * the fragment header.) | |
289 | */ | |
290 | skb_pull_rcsum(skb_out, hdr_size); | |
291 | memmove(skb_out->data - ETH_HLEN, skb_mac_header(skb_out), ETH_HLEN); | |
292 | skb_set_mac_header(skb_out, -ETH_HLEN); | |
293 | skb_reset_network_header(skb_out); | |
294 | skb_reset_transport_header(skb_out); | |
295 | ||
296 | /* Copy the payload of the each fragment into the last skb */ | |
297 | hlist_for_each_entry(entry, chain, list) { | |
298 | size = entry->skb->len - hdr_size; | |
299 | memcpy(skb_put(skb_out, size), entry->skb->data + hdr_size, | |
300 | size); | |
301 | } | |
302 | ||
303 | free: | |
304 | /* Locking is not needed, because 'chain' is not part of any orig. */ | |
bd687fe4 | 305 | batadv_frag_clear_chain(chain, dropped); |
610bfc6b MH |
306 | return skb_out; |
307 | } | |
308 | ||
309 | /** | |
310 | * batadv_frag_skb_buffer - buffer fragment for later merge | |
311 | * @skb: skb to buffer | |
312 | * @orig_node_src: originator that the skb is received from | |
313 | * | |
314 | * Add fragment to buffer and merge fragments if possible. | |
315 | * | |
316 | * There are three possible outcomes: 1) Packet is merged: Return true and | |
317 | * set *skb to merged packet; 2) Packet is buffered: Return true and set *skb | |
248e23b5 | 318 | * to NULL; 3) Error: Return false and free skb. |
62fe710f SE |
319 | * |
320 | * Return: true when packet is merged or buffered, false when skb is not not | |
321 | * used. | |
610bfc6b MH |
322 | */ |
323 | bool batadv_frag_skb_buffer(struct sk_buff **skb, | |
324 | struct batadv_orig_node *orig_node_src) | |
325 | { | |
326 | struct sk_buff *skb_out = NULL; | |
327 | struct hlist_head head = HLIST_HEAD_INIT; | |
328 | bool ret = false; | |
329 | ||
330 | /* Add packet to buffer and table entry if merge is possible. */ | |
331 | if (!batadv_frag_insert_packet(orig_node_src, *skb, &head)) | |
332 | goto out_err; | |
333 | ||
334 | /* Leave if more fragments are needed to merge. */ | |
335 | if (hlist_empty(&head)) | |
336 | goto out; | |
337 | ||
83e8b877 | 338 | skb_out = batadv_frag_merge_packets(&head); |
610bfc6b MH |
339 | if (!skb_out) |
340 | goto out_err; | |
341 | ||
342 | out: | |
610bfc6b MH |
343 | ret = true; |
344 | out_err: | |
248e23b5 | 345 | *skb = skb_out; |
610bfc6b MH |
346 | return ret; |
347 | } | |
348 | ||
349 | /** | |
350 | * batadv_frag_skb_fwd - forward fragments that would exceed MTU when merged | |
351 | * @skb: skb to forward | |
352 | * @recv_if: interface that the skb is received on | |
353 | * @orig_node_src: originator that the skb is received from | |
354 | * | |
355 | * Look up the next-hop of the fragments payload and check if the merged packet | |
356 | * will exceed the MTU towards the next-hop. If so, the fragment is forwarded | |
357 | * without merging it. | |
358 | * | |
62fe710f | 359 | * Return: true if the fragment is consumed/forwarded, false otherwise. |
610bfc6b MH |
360 | */ |
361 | bool batadv_frag_skb_fwd(struct sk_buff *skb, | |
362 | struct batadv_hard_iface *recv_if, | |
363 | struct batadv_orig_node *orig_node_src) | |
364 | { | |
365 | struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface); | |
422d2f77 | 366 | struct batadv_orig_node *orig_node_dst; |
610bfc6b MH |
367 | struct batadv_neigh_node *neigh_node = NULL; |
368 | struct batadv_frag_packet *packet; | |
6b5e971a | 369 | u16 total_size; |
610bfc6b MH |
370 | bool ret = false; |
371 | ||
372 | packet = (struct batadv_frag_packet *)skb->data; | |
373 | orig_node_dst = batadv_orig_hash_find(bat_priv, packet->dest); | |
374 | if (!orig_node_dst) | |
375 | goto out; | |
376 | ||
377 | neigh_node = batadv_find_router(bat_priv, orig_node_dst, recv_if); | |
378 | if (!neigh_node) | |
379 | goto out; | |
380 | ||
381 | /* Forward the fragment, if the merged packet would be too big to | |
382 | * be assembled. | |
383 | */ | |
384 | total_size = ntohs(packet->total_size); | |
385 | if (total_size > neigh_node->if_incoming->net_dev->mtu) { | |
386 | batadv_inc_counter(bat_priv, BATADV_CNT_FRAG_FWD); | |
387 | batadv_add_counter(bat_priv, BATADV_CNT_FRAG_FWD_BYTES, | |
388 | skb->len + ETH_HLEN); | |
389 | ||
a40d9b07 | 390 | packet->ttl--; |
95d39278 | 391 | batadv_send_unicast_skb(skb, neigh_node); |
610bfc6b MH |
392 | ret = true; |
393 | } | |
394 | ||
395 | out: | |
396 | if (orig_node_dst) | |
5d967310 | 397 | batadv_orig_node_put(orig_node_dst); |
610bfc6b | 398 | if (neigh_node) |
25bb2509 | 399 | batadv_neigh_node_put(neigh_node); |
610bfc6b MH |
400 | return ret; |
401 | } | |
ee75ed88 MH |
402 | |
403 | /** | |
404 | * batadv_frag_create - create a fragment from skb | |
405 | * @skb: skb to create fragment from | |
406 | * @frag_head: header to use in new fragment | |
1c2bcc76 | 407 | * @fragment_size: size of new fragment |
ee75ed88 MH |
408 | * |
409 | * Split the passed skb into two fragments: A new one with size matching the | |
410 | * passed mtu and the old one with the rest. The new skb contains data from the | |
411 | * tail of the old skb. | |
412 | * | |
62fe710f | 413 | * Return: the new fragment, NULL on error. |
ee75ed88 MH |
414 | */ |
415 | static struct sk_buff *batadv_frag_create(struct sk_buff *skb, | |
416 | struct batadv_frag_packet *frag_head, | |
1c2bcc76 | 417 | unsigned int fragment_size) |
ee75ed88 MH |
418 | { |
419 | struct sk_buff *skb_fragment; | |
d3abce78 | 420 | unsigned int header_size = sizeof(*frag_head); |
1c2bcc76 | 421 | unsigned int mtu = fragment_size + header_size; |
ee75ed88 MH |
422 | |
423 | skb_fragment = netdev_alloc_skb(NULL, mtu + ETH_HLEN); | |
424 | if (!skb_fragment) | |
425 | goto err; | |
426 | ||
1914848e | 427 | skb_fragment->priority = skb->priority; |
ee75ed88 MH |
428 | |
429 | /* Eat the last mtu-bytes of the skb */ | |
430 | skb_reserve(skb_fragment, header_size + ETH_HLEN); | |
431 | skb_split(skb, skb_fragment, skb->len - fragment_size); | |
432 | ||
433 | /* Add the header */ | |
434 | skb_push(skb_fragment, header_size); | |
435 | memcpy(skb_fragment->data, frag_head, header_size); | |
436 | ||
437 | err: | |
438 | return skb_fragment; | |
439 | } | |
440 | ||
441 | /** | |
442 | * batadv_frag_send_packet - create up to 16 fragments from the passed skb | |
443 | * @skb: skb to create fragments from | |
444 | * @orig_node: final destination of the created fragments | |
445 | * @neigh_node: next-hop of the created fragments | |
446 | * | |
8def0be8 | 447 | * Return: the netdev tx status or a negative errno code on a failure |
ee75ed88 | 448 | */ |
f50ca95a AQ |
449 | int batadv_frag_send_packet(struct sk_buff *skb, |
450 | struct batadv_orig_node *orig_node, | |
451 | struct batadv_neigh_node *neigh_node) | |
ee75ed88 MH |
452 | { |
453 | struct batadv_priv *bat_priv; | |
be181015 | 454 | struct batadv_hard_iface *primary_if = NULL; |
ee75ed88 MH |
455 | struct batadv_frag_packet frag_header; |
456 | struct sk_buff *skb_fragment; | |
d3abce78 SE |
457 | unsigned int mtu = neigh_node->if_incoming->net_dev->mtu; |
458 | unsigned int header_size = sizeof(frag_header); | |
1c2bcc76 | 459 | unsigned int max_fragment_size, num_fragments; |
8def0be8 | 460 | int ret; |
ee75ed88 MH |
461 | |
462 | /* To avoid merge and refragmentation at next-hops we never send | |
463 | * fragments larger than BATADV_FRAG_MAX_FRAG_SIZE | |
464 | */ | |
d3abce78 | 465 | mtu = min_t(unsigned int, mtu, BATADV_FRAG_MAX_FRAG_SIZE); |
0402e444 | 466 | max_fragment_size = mtu - header_size; |
1c2bcc76 SE |
467 | |
468 | if (skb->len == 0 || max_fragment_size == 0) | |
469 | return -EINVAL; | |
470 | ||
471 | num_fragments = (skb->len - 1) / max_fragment_size + 1; | |
472 | max_fragment_size = (skb->len - 1) / num_fragments + 1; | |
ee75ed88 MH |
473 | |
474 | /* Don't even try to fragment, if we need more than 16 fragments */ | |
1c2bcc76 | 475 | if (num_fragments > BATADV_FRAG_MAX_FRAGMENTS) { |
8def0be8 SE |
476 | ret = -EAGAIN; |
477 | goto free_skb; | |
478 | } | |
ee75ed88 MH |
479 | |
480 | bat_priv = orig_node->bat_priv; | |
481 | primary_if = batadv_primary_if_get_selected(bat_priv); | |
8def0be8 SE |
482 | if (!primary_if) { |
483 | ret = -EINVAL; | |
4ea33ef0 | 484 | goto free_skb; |
8def0be8 | 485 | } |
ee75ed88 MH |
486 | |
487 | /* Create one header to be copied to all fragments */ | |
a40d9b07 SW |
488 | frag_header.packet_type = BATADV_UNICAST_FRAG; |
489 | frag_header.version = BATADV_COMPAT_VERSION; | |
490 | frag_header.ttl = BATADV_TTL; | |
ee75ed88 MH |
491 | frag_header.seqno = htons(atomic_inc_return(&bat_priv->frag_seqno)); |
492 | frag_header.reserved = 0; | |
493 | frag_header.no = 0; | |
494 | frag_header.total_size = htons(skb->len); | |
c0f25c80 AL |
495 | |
496 | /* skb->priority values from 256->263 are magic values to | |
497 | * directly indicate a specific 802.1d priority. This is used | |
498 | * to allow 802.1d priority to be passed directly in from VLAN | |
499 | * tags, etc. | |
500 | */ | |
501 | if (skb->priority >= 256 && skb->priority <= 263) | |
502 | frag_header.priority = skb->priority - 256; | |
503 | ||
8fdd0153 AQ |
504 | ether_addr_copy(frag_header.orig, primary_if->net_dev->dev_addr); |
505 | ether_addr_copy(frag_header.dest, orig_node->orig); | |
ee75ed88 MH |
506 | |
507 | /* Eat and send fragments from the tail of skb */ | |
508 | while (skb->len > max_fragment_size) { | |
51c6b429 LL |
509 | /* The initial check in this function should cover this case */ |
510 | if (unlikely(frag_header.no == BATADV_FRAG_MAX_FRAGMENTS - 1)) { | |
511 | ret = -EINVAL; | |
512 | goto put_primary_if; | |
513 | } | |
514 | ||
1c2bcc76 SE |
515 | skb_fragment = batadv_frag_create(skb, &frag_header, |
516 | max_fragment_size); | |
8def0be8 SE |
517 | if (!skb_fragment) { |
518 | ret = -ENOMEM; | |
4ea33ef0 | 519 | goto put_primary_if; |
8def0be8 | 520 | } |
ee75ed88 MH |
521 | |
522 | batadv_inc_counter(bat_priv, BATADV_CNT_FRAG_TX); | |
523 | batadv_add_counter(bat_priv, BATADV_CNT_FRAG_TX_BYTES, | |
524 | skb_fragment->len + ETH_HLEN); | |
f50ca95a AQ |
525 | ret = batadv_send_unicast_skb(skb_fragment, neigh_node); |
526 | if (ret != NET_XMIT_SUCCESS) { | |
8def0be8 | 527 | ret = NET_XMIT_DROP; |
4ea33ef0 | 528 | goto put_primary_if; |
f50ca95a AQ |
529 | } |
530 | ||
ee75ed88 | 531 | frag_header.no++; |
ee75ed88 MH |
532 | } |
533 | ||
534 | /* Make room for the fragment header. */ | |
535 | if (batadv_skb_head_push(skb, header_size) < 0 || | |
8def0be8 SE |
536 | pskb_expand_head(skb, header_size + ETH_HLEN, 0, GFP_ATOMIC) < 0) { |
537 | ret = -ENOMEM; | |
4ea33ef0 | 538 | goto put_primary_if; |
8def0be8 | 539 | } |
ee75ed88 MH |
540 | |
541 | memcpy(skb->data, &frag_header, header_size); | |
542 | ||
543 | /* Send the last fragment */ | |
544 | batadv_inc_counter(bat_priv, BATADV_CNT_FRAG_TX); | |
545 | batadv_add_counter(bat_priv, BATADV_CNT_FRAG_TX_BYTES, | |
546 | skb->len + ETH_HLEN); | |
f50ca95a | 547 | ret = batadv_send_unicast_skb(skb, neigh_node); |
8def0be8 SE |
548 | /* skb was consumed */ |
549 | skb = NULL; | |
ee75ed88 | 550 | |
8def0be8 SE |
551 | put_primary_if: |
552 | batadv_hardif_put(primary_if); | |
553 | free_skb: | |
554 | kfree_skb(skb); | |
be181015 AQ |
555 | |
556 | return ret; | |
ee75ed88 | 557 | } |