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7db7d9f3 | 1 | // SPDX-License-Identifier: GPL-2.0 |
68e039f9 | 2 | /* Copyright (C) 2013-2020 B.A.T.M.A.N. contributors: |
610bfc6b MH |
3 | * |
4 | * Martin Hundebøll <martin@hundeboll.net> | |
610bfc6b MH |
5 | */ |
6 | ||
610bfc6b | 7 | #include "fragmentation.h" |
1e2c2a4f SE |
8 | #include "main.h" |
9 | ||
10 | #include <linux/atomic.h> | |
11 | #include <linux/byteorder/generic.h> | |
8def0be8 | 12 | #include <linux/errno.h> |
1e2c2a4f | 13 | #include <linux/etherdevice.h> |
b92b94ac | 14 | #include <linux/gfp.h> |
1e2c2a4f SE |
15 | #include <linux/if_ether.h> |
16 | #include <linux/jiffies.h> | |
17 | #include <linux/kernel.h> | |
5274cd68 | 18 | #include <linux/lockdep.h> |
1e2c2a4f | 19 | #include <linux/netdevice.h> |
1e2c2a4f SE |
20 | #include <linux/skbuff.h> |
21 | #include <linux/slab.h> | |
22 | #include <linux/spinlock.h> | |
23 | #include <linux/string.h> | |
fec149f5 | 24 | #include <uapi/linux/batadv_packet.h> |
1e2c2a4f SE |
25 | |
26 | #include "hard-interface.h" | |
610bfc6b MH |
27 | #include "originator.h" |
28 | #include "routing.h" | |
1e2c2a4f | 29 | #include "send.h" |
610bfc6b MH |
30 | #include "soft-interface.h" |
31 | ||
610bfc6b | 32 | /** |
7e9a8c2c | 33 | * batadv_frag_clear_chain() - delete entries in the fragment buffer chain |
610bfc6b | 34 | * @head: head of chain with entries. |
bd687fe4 | 35 | * @dropped: whether the chain is cleared because all fragments are dropped |
610bfc6b MH |
36 | * |
37 | * Free fragments in the passed hlist. Should be called with appropriate lock. | |
38 | */ | |
bd687fe4 | 39 | static void batadv_frag_clear_chain(struct hlist_head *head, bool dropped) |
610bfc6b MH |
40 | { |
41 | struct batadv_frag_list_entry *entry; | |
42 | struct hlist_node *node; | |
43 | ||
44 | hlist_for_each_entry_safe(entry, node, head, list) { | |
45 | hlist_del(&entry->list); | |
bd687fe4 SE |
46 | |
47 | if (dropped) | |
48 | kfree_skb(entry->skb); | |
49 | else | |
50 | consume_skb(entry->skb); | |
51 | ||
610bfc6b MH |
52 | kfree(entry); |
53 | } | |
54 | } | |
55 | ||
56 | /** | |
7e9a8c2c | 57 | * batadv_frag_purge_orig() - free fragments associated to an orig |
610bfc6b MH |
58 | * @orig_node: originator to free fragments from |
59 | * @check_cb: optional function to tell if an entry should be purged | |
60 | */ | |
61 | void batadv_frag_purge_orig(struct batadv_orig_node *orig_node, | |
62 | bool (*check_cb)(struct batadv_frag_table_entry *)) | |
63 | { | |
64 | struct batadv_frag_table_entry *chain; | |
6b5e971a | 65 | u8 i; |
610bfc6b MH |
66 | |
67 | for (i = 0; i < BATADV_FRAG_BUFFER_COUNT; i++) { | |
68 | chain = &orig_node->fragments[i]; | |
01f6b5c7 | 69 | spin_lock_bh(&chain->lock); |
610bfc6b MH |
70 | |
71 | if (!check_cb || check_cb(chain)) { | |
bd687fe4 | 72 | batadv_frag_clear_chain(&chain->fragment_list, true); |
01f6b5c7 | 73 | chain->size = 0; |
610bfc6b MH |
74 | } |
75 | ||
01f6b5c7 | 76 | spin_unlock_bh(&chain->lock); |
610bfc6b MH |
77 | } |
78 | } | |
79 | ||
80 | /** | |
7e9a8c2c | 81 | * batadv_frag_size_limit() - maximum possible size of packet to be fragmented |
610bfc6b | 82 | * |
62fe710f | 83 | * Return: the maximum size of payload that can be fragmented. |
610bfc6b MH |
84 | */ |
85 | static int batadv_frag_size_limit(void) | |
86 | { | |
87 | int limit = BATADV_FRAG_MAX_FRAG_SIZE; | |
88 | ||
89 | limit -= sizeof(struct batadv_frag_packet); | |
90 | limit *= BATADV_FRAG_MAX_FRAGMENTS; | |
91 | ||
92 | return limit; | |
93 | } | |
94 | ||
95 | /** | |
7e9a8c2c | 96 | * batadv_frag_init_chain() - check and prepare fragment chain for new fragment |
610bfc6b MH |
97 | * @chain: chain in fragments table to init |
98 | * @seqno: sequence number of the received fragment | |
99 | * | |
100 | * Make chain ready for a fragment with sequence number "seqno". Delete existing | |
101 | * entries if they have an "old" sequence number. | |
102 | * | |
103 | * Caller must hold chain->lock. | |
104 | * | |
bccb48c8 SE |
105 | * Return: true if chain is empty and the caller can just insert the new |
106 | * fragment without searching for the right position. | |
610bfc6b MH |
107 | */ |
108 | static bool batadv_frag_init_chain(struct batadv_frag_table_entry *chain, | |
6b5e971a | 109 | u16 seqno) |
610bfc6b | 110 | { |
5274cd68 SE |
111 | lockdep_assert_held(&chain->lock); |
112 | ||
610bfc6b MH |
113 | if (chain->seqno == seqno) |
114 | return false; | |
115 | ||
176e5b77 | 116 | if (!hlist_empty(&chain->fragment_list)) |
bd687fe4 | 117 | batadv_frag_clear_chain(&chain->fragment_list, true); |
610bfc6b MH |
118 | |
119 | chain->size = 0; | |
120 | chain->seqno = seqno; | |
121 | ||
122 | return true; | |
123 | } | |
124 | ||
125 | /** | |
7e9a8c2c | 126 | * batadv_frag_insert_packet() - insert a fragment into a fragment chain |
610bfc6b MH |
127 | * @orig_node: originator that the fragment was received from |
128 | * @skb: skb to insert | |
129 | * @chain_out: list head to attach complete chains of fragments to | |
130 | * | |
131 | * Insert a new fragment into the reverse ordered chain in the right table | |
132 | * entry. The hash table entry is cleared if "old" fragments exist in it. | |
133 | * | |
62fe710f | 134 | * Return: true if skb is buffered, false on error. If the chain has all the |
610bfc6b MH |
135 | * fragments needed to merge the packet, the chain is moved to the passed head |
136 | * to avoid locking the chain in the table. | |
137 | */ | |
138 | static bool batadv_frag_insert_packet(struct batadv_orig_node *orig_node, | |
139 | struct sk_buff *skb, | |
140 | struct hlist_head *chain_out) | |
141 | { | |
142 | struct batadv_frag_table_entry *chain; | |
143 | struct batadv_frag_list_entry *frag_entry_new = NULL, *frag_entry_curr; | |
d9124268 | 144 | struct batadv_frag_list_entry *frag_entry_last = NULL; |
610bfc6b | 145 | struct batadv_frag_packet *frag_packet; |
6b5e971a SE |
146 | u8 bucket; |
147 | u16 seqno, hdr_size = sizeof(struct batadv_frag_packet); | |
610bfc6b MH |
148 | bool ret = false; |
149 | ||
150 | /* Linearize packet to avoid linearizing 16 packets in a row when doing | |
151 | * the later merge. Non-linear merge should be added to remove this | |
152 | * linearization. | |
153 | */ | |
154 | if (skb_linearize(skb) < 0) | |
155 | goto err; | |
156 | ||
157 | frag_packet = (struct batadv_frag_packet *)skb->data; | |
158 | seqno = ntohs(frag_packet->seqno); | |
159 | bucket = seqno % BATADV_FRAG_BUFFER_COUNT; | |
160 | ||
161 | frag_entry_new = kmalloc(sizeof(*frag_entry_new), GFP_ATOMIC); | |
162 | if (!frag_entry_new) | |
163 | goto err; | |
164 | ||
165 | frag_entry_new->skb = skb; | |
166 | frag_entry_new->no = frag_packet->no; | |
167 | ||
168 | /* Select entry in the "chain table" and delete any prior fragments | |
169 | * with another sequence number. batadv_frag_init_chain() returns true, | |
170 | * if the list is empty at return. | |
171 | */ | |
172 | chain = &orig_node->fragments[bucket]; | |
173 | spin_lock_bh(&chain->lock); | |
174 | if (batadv_frag_init_chain(chain, seqno)) { | |
176e5b77 | 175 | hlist_add_head(&frag_entry_new->list, &chain->fragment_list); |
610bfc6b MH |
176 | chain->size = skb->len - hdr_size; |
177 | chain->timestamp = jiffies; | |
53e77145 | 178 | chain->total_size = ntohs(frag_packet->total_size); |
610bfc6b MH |
179 | ret = true; |
180 | goto out; | |
181 | } | |
182 | ||
183 | /* Find the position for the new fragment. */ | |
176e5b77 | 184 | hlist_for_each_entry(frag_entry_curr, &chain->fragment_list, list) { |
610bfc6b MH |
185 | /* Drop packet if fragment already exists. */ |
186 | if (frag_entry_curr->no == frag_entry_new->no) | |
187 | goto err_unlock; | |
188 | ||
189 | /* Order fragments from highest to lowest. */ | |
190 | if (frag_entry_curr->no < frag_entry_new->no) { | |
191 | hlist_add_before(&frag_entry_new->list, | |
192 | &frag_entry_curr->list); | |
193 | chain->size += skb->len - hdr_size; | |
194 | chain->timestamp = jiffies; | |
195 | ret = true; | |
196 | goto out; | |
197 | } | |
d9124268 SE |
198 | |
199 | /* store current entry because it could be the last in list */ | |
200 | frag_entry_last = frag_entry_curr; | |
610bfc6b MH |
201 | } |
202 | ||
d9124268 SE |
203 | /* Reached the end of the list, so insert after 'frag_entry_last'. */ |
204 | if (likely(frag_entry_last)) { | |
e050dbeb | 205 | hlist_add_behind(&frag_entry_new->list, &frag_entry_last->list); |
610bfc6b MH |
206 | chain->size += skb->len - hdr_size; |
207 | chain->timestamp = jiffies; | |
208 | ret = true; | |
209 | } | |
210 | ||
211 | out: | |
212 | if (chain->size > batadv_frag_size_limit() || | |
53e77145 SE |
213 | chain->total_size != ntohs(frag_packet->total_size) || |
214 | chain->total_size > batadv_frag_size_limit()) { | |
610bfc6b | 215 | /* Clear chain if total size of either the list or the packet |
53e77145 SE |
216 | * exceeds the maximum size of one merged packet. Don't allow |
217 | * packets to have different total_size. | |
610bfc6b | 218 | */ |
bd687fe4 | 219 | batadv_frag_clear_chain(&chain->fragment_list, true); |
610bfc6b MH |
220 | chain->size = 0; |
221 | } else if (ntohs(frag_packet->total_size) == chain->size) { | |
222 | /* All fragments received. Hand over chain to caller. */ | |
176e5b77 | 223 | hlist_move_list(&chain->fragment_list, chain_out); |
610bfc6b MH |
224 | chain->size = 0; |
225 | } | |
226 | ||
227 | err_unlock: | |
228 | spin_unlock_bh(&chain->lock); | |
229 | ||
230 | err: | |
248e23b5 | 231 | if (!ret) { |
610bfc6b | 232 | kfree(frag_entry_new); |
248e23b5 SE |
233 | kfree_skb(skb); |
234 | } | |
610bfc6b MH |
235 | |
236 | return ret; | |
237 | } | |
238 | ||
239 | /** | |
7e9a8c2c | 240 | * batadv_frag_merge_packets() - merge a chain of fragments |
610bfc6b | 241 | * @chain: head of chain with fragments |
610bfc6b MH |
242 | * |
243 | * Expand the first skb in the chain and copy the content of the remaining | |
244 | * skb's into the expanded one. After doing so, clear the chain. | |
245 | * | |
62fe710f | 246 | * Return: the merged skb or NULL on error. |
610bfc6b MH |
247 | */ |
248 | static struct sk_buff * | |
83e8b877 | 249 | batadv_frag_merge_packets(struct hlist_head *chain) |
610bfc6b MH |
250 | { |
251 | struct batadv_frag_packet *packet; | |
252 | struct batadv_frag_list_entry *entry; | |
422d2f77 | 253 | struct sk_buff *skb_out; |
610bfc6b | 254 | int size, hdr_size = sizeof(struct batadv_frag_packet); |
bd687fe4 | 255 | bool dropped = false; |
610bfc6b | 256 | |
610bfc6b MH |
257 | /* Remove first entry, as this is the destination for the rest of the |
258 | * fragments. | |
259 | */ | |
260 | entry = hlist_entry(chain->first, struct batadv_frag_list_entry, list); | |
261 | hlist_del(&entry->list); | |
262 | skb_out = entry->skb; | |
263 | kfree(entry); | |
264 | ||
83e8b877 | 265 | packet = (struct batadv_frag_packet *)skb_out->data; |
d7d8bbb4 | 266 | size = ntohs(packet->total_size) + hdr_size; |
83e8b877 | 267 | |
610bfc6b | 268 | /* Make room for the rest of the fragments. */ |
5b6698b0 | 269 | if (pskb_expand_head(skb_out, 0, size - skb_out->len, GFP_ATOMIC) < 0) { |
610bfc6b MH |
270 | kfree_skb(skb_out); |
271 | skb_out = NULL; | |
bd687fe4 | 272 | dropped = true; |
610bfc6b MH |
273 | goto free; |
274 | } | |
275 | ||
276 | /* Move the existing MAC header to just before the payload. (Override | |
277 | * the fragment header.) | |
278 | */ | |
3bf2a09d MS |
279 | skb_pull(skb_out, hdr_size); |
280 | skb_out->ip_summed = CHECKSUM_NONE; | |
610bfc6b MH |
281 | memmove(skb_out->data - ETH_HLEN, skb_mac_header(skb_out), ETH_HLEN); |
282 | skb_set_mac_header(skb_out, -ETH_HLEN); | |
283 | skb_reset_network_header(skb_out); | |
284 | skb_reset_transport_header(skb_out); | |
285 | ||
286 | /* Copy the payload of the each fragment into the last skb */ | |
287 | hlist_for_each_entry(entry, chain, list) { | |
288 | size = entry->skb->len - hdr_size; | |
59ae1d12 | 289 | skb_put_data(skb_out, entry->skb->data + hdr_size, size); |
610bfc6b MH |
290 | } |
291 | ||
292 | free: | |
293 | /* Locking is not needed, because 'chain' is not part of any orig. */ | |
bd687fe4 | 294 | batadv_frag_clear_chain(chain, dropped); |
610bfc6b MH |
295 | return skb_out; |
296 | } | |
297 | ||
298 | /** | |
7e9a8c2c | 299 | * batadv_frag_skb_buffer() - buffer fragment for later merge |
610bfc6b MH |
300 | * @skb: skb to buffer |
301 | * @orig_node_src: originator that the skb is received from | |
302 | * | |
303 | * Add fragment to buffer and merge fragments if possible. | |
304 | * | |
305 | * There are three possible outcomes: 1) Packet is merged: Return true and | |
306 | * set *skb to merged packet; 2) Packet is buffered: Return true and set *skb | |
248e23b5 | 307 | * to NULL; 3) Error: Return false and free skb. |
62fe710f | 308 | * |
21ba5ab2 | 309 | * Return: true when the packet is merged or buffered, false when skb is not |
62fe710f | 310 | * used. |
610bfc6b MH |
311 | */ |
312 | bool batadv_frag_skb_buffer(struct sk_buff **skb, | |
313 | struct batadv_orig_node *orig_node_src) | |
314 | { | |
315 | struct sk_buff *skb_out = NULL; | |
316 | struct hlist_head head = HLIST_HEAD_INIT; | |
317 | bool ret = false; | |
318 | ||
319 | /* Add packet to buffer and table entry if merge is possible. */ | |
320 | if (!batadv_frag_insert_packet(orig_node_src, *skb, &head)) | |
321 | goto out_err; | |
322 | ||
323 | /* Leave if more fragments are needed to merge. */ | |
324 | if (hlist_empty(&head)) | |
325 | goto out; | |
326 | ||
83e8b877 | 327 | skb_out = batadv_frag_merge_packets(&head); |
610bfc6b MH |
328 | if (!skb_out) |
329 | goto out_err; | |
330 | ||
331 | out: | |
610bfc6b MH |
332 | ret = true; |
333 | out_err: | |
248e23b5 | 334 | *skb = skb_out; |
610bfc6b MH |
335 | return ret; |
336 | } | |
337 | ||
338 | /** | |
7e9a8c2c | 339 | * batadv_frag_skb_fwd() - forward fragments that would exceed MTU when merged |
610bfc6b MH |
340 | * @skb: skb to forward |
341 | * @recv_if: interface that the skb is received on | |
342 | * @orig_node_src: originator that the skb is received from | |
343 | * | |
344 | * Look up the next-hop of the fragments payload and check if the merged packet | |
345 | * will exceed the MTU towards the next-hop. If so, the fragment is forwarded | |
346 | * without merging it. | |
347 | * | |
62fe710f | 348 | * Return: true if the fragment is consumed/forwarded, false otherwise. |
610bfc6b MH |
349 | */ |
350 | bool batadv_frag_skb_fwd(struct sk_buff *skb, | |
351 | struct batadv_hard_iface *recv_if, | |
352 | struct batadv_orig_node *orig_node_src) | |
353 | { | |
354 | struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface); | |
422d2f77 | 355 | struct batadv_orig_node *orig_node_dst; |
610bfc6b MH |
356 | struct batadv_neigh_node *neigh_node = NULL; |
357 | struct batadv_frag_packet *packet; | |
6b5e971a | 358 | u16 total_size; |
610bfc6b MH |
359 | bool ret = false; |
360 | ||
361 | packet = (struct batadv_frag_packet *)skb->data; | |
362 | orig_node_dst = batadv_orig_hash_find(bat_priv, packet->dest); | |
363 | if (!orig_node_dst) | |
364 | goto out; | |
365 | ||
366 | neigh_node = batadv_find_router(bat_priv, orig_node_dst, recv_if); | |
367 | if (!neigh_node) | |
368 | goto out; | |
369 | ||
370 | /* Forward the fragment, if the merged packet would be too big to | |
371 | * be assembled. | |
372 | */ | |
373 | total_size = ntohs(packet->total_size); | |
374 | if (total_size > neigh_node->if_incoming->net_dev->mtu) { | |
375 | batadv_inc_counter(bat_priv, BATADV_CNT_FRAG_FWD); | |
376 | batadv_add_counter(bat_priv, BATADV_CNT_FRAG_FWD_BYTES, | |
377 | skb->len + ETH_HLEN); | |
378 | ||
a40d9b07 | 379 | packet->ttl--; |
95d39278 | 380 | batadv_send_unicast_skb(skb, neigh_node); |
610bfc6b MH |
381 | ret = true; |
382 | } | |
383 | ||
384 | out: | |
385 | if (orig_node_dst) | |
5d967310 | 386 | batadv_orig_node_put(orig_node_dst); |
610bfc6b | 387 | if (neigh_node) |
25bb2509 | 388 | batadv_neigh_node_put(neigh_node); |
610bfc6b MH |
389 | return ret; |
390 | } | |
ee75ed88 MH |
391 | |
392 | /** | |
7e9a8c2c | 393 | * batadv_frag_create() - create a fragment from skb |
c5cbfc87 | 394 | * @net_dev: outgoing device for fragment |
ee75ed88 MH |
395 | * @skb: skb to create fragment from |
396 | * @frag_head: header to use in new fragment | |
1c2bcc76 | 397 | * @fragment_size: size of new fragment |
ee75ed88 MH |
398 | * |
399 | * Split the passed skb into two fragments: A new one with size matching the | |
400 | * passed mtu and the old one with the rest. The new skb contains data from the | |
401 | * tail of the old skb. | |
402 | * | |
62fe710f | 403 | * Return: the new fragment, NULL on error. |
ee75ed88 | 404 | */ |
c5cbfc87 SE |
405 | static struct sk_buff *batadv_frag_create(struct net_device *net_dev, |
406 | struct sk_buff *skb, | |
ee75ed88 | 407 | struct batadv_frag_packet *frag_head, |
1c2bcc76 | 408 | unsigned int fragment_size) |
ee75ed88 | 409 | { |
c5cbfc87 SE |
410 | unsigned int ll_reserved = LL_RESERVED_SPACE(net_dev); |
411 | unsigned int tailroom = net_dev->needed_tailroom; | |
ee75ed88 | 412 | struct sk_buff *skb_fragment; |
d3abce78 | 413 | unsigned int header_size = sizeof(*frag_head); |
1c2bcc76 | 414 | unsigned int mtu = fragment_size + header_size; |
ee75ed88 | 415 | |
c5cbfc87 | 416 | skb_fragment = dev_alloc_skb(ll_reserved + mtu + tailroom); |
ee75ed88 MH |
417 | if (!skb_fragment) |
418 | goto err; | |
419 | ||
1914848e | 420 | skb_fragment->priority = skb->priority; |
ee75ed88 MH |
421 | |
422 | /* Eat the last mtu-bytes of the skb */ | |
c5cbfc87 | 423 | skb_reserve(skb_fragment, ll_reserved + header_size); |
ee75ed88 MH |
424 | skb_split(skb, skb_fragment, skb->len - fragment_size); |
425 | ||
426 | /* Add the header */ | |
427 | skb_push(skb_fragment, header_size); | |
428 | memcpy(skb_fragment->data, frag_head, header_size); | |
429 | ||
430 | err: | |
431 | return skb_fragment; | |
432 | } | |
433 | ||
434 | /** | |
7e9a8c2c | 435 | * batadv_frag_send_packet() - create up to 16 fragments from the passed skb |
ee75ed88 MH |
436 | * @skb: skb to create fragments from |
437 | * @orig_node: final destination of the created fragments | |
438 | * @neigh_node: next-hop of the created fragments | |
439 | * | |
8def0be8 | 440 | * Return: the netdev tx status or a negative errno code on a failure |
ee75ed88 | 441 | */ |
f50ca95a AQ |
442 | int batadv_frag_send_packet(struct sk_buff *skb, |
443 | struct batadv_orig_node *orig_node, | |
444 | struct batadv_neigh_node *neigh_node) | |
ee75ed88 | 445 | { |
c5cbfc87 | 446 | struct net_device *net_dev = neigh_node->if_incoming->net_dev; |
ee75ed88 | 447 | struct batadv_priv *bat_priv; |
be181015 | 448 | struct batadv_hard_iface *primary_if = NULL; |
ee75ed88 MH |
449 | struct batadv_frag_packet frag_header; |
450 | struct sk_buff *skb_fragment; | |
c5cbfc87 | 451 | unsigned int mtu = net_dev->mtu; |
d3abce78 | 452 | unsigned int header_size = sizeof(frag_header); |
1c2bcc76 | 453 | unsigned int max_fragment_size, num_fragments; |
8def0be8 | 454 | int ret; |
ee75ed88 MH |
455 | |
456 | /* To avoid merge and refragmentation at next-hops we never send | |
457 | * fragments larger than BATADV_FRAG_MAX_FRAG_SIZE | |
458 | */ | |
d3abce78 | 459 | mtu = min_t(unsigned int, mtu, BATADV_FRAG_MAX_FRAG_SIZE); |
0402e444 | 460 | max_fragment_size = mtu - header_size; |
1c2bcc76 SE |
461 | |
462 | if (skb->len == 0 || max_fragment_size == 0) | |
463 | return -EINVAL; | |
464 | ||
465 | num_fragments = (skb->len - 1) / max_fragment_size + 1; | |
466 | max_fragment_size = (skb->len - 1) / num_fragments + 1; | |
ee75ed88 MH |
467 | |
468 | /* Don't even try to fragment, if we need more than 16 fragments */ | |
1c2bcc76 | 469 | if (num_fragments > BATADV_FRAG_MAX_FRAGMENTS) { |
8def0be8 SE |
470 | ret = -EAGAIN; |
471 | goto free_skb; | |
472 | } | |
ee75ed88 MH |
473 | |
474 | bat_priv = orig_node->bat_priv; | |
475 | primary_if = batadv_primary_if_get_selected(bat_priv); | |
8def0be8 SE |
476 | if (!primary_if) { |
477 | ret = -EINVAL; | |
4ea33ef0 | 478 | goto free_skb; |
8def0be8 | 479 | } |
ee75ed88 MH |
480 | |
481 | /* Create one header to be copied to all fragments */ | |
a40d9b07 SW |
482 | frag_header.packet_type = BATADV_UNICAST_FRAG; |
483 | frag_header.version = BATADV_COMPAT_VERSION; | |
484 | frag_header.ttl = BATADV_TTL; | |
ee75ed88 MH |
485 | frag_header.seqno = htons(atomic_inc_return(&bat_priv->frag_seqno)); |
486 | frag_header.reserved = 0; | |
487 | frag_header.no = 0; | |
488 | frag_header.total_size = htons(skb->len); | |
c0f25c80 AL |
489 | |
490 | /* skb->priority values from 256->263 are magic values to | |
491 | * directly indicate a specific 802.1d priority. This is used | |
492 | * to allow 802.1d priority to be passed directly in from VLAN | |
493 | * tags, etc. | |
494 | */ | |
495 | if (skb->priority >= 256 && skb->priority <= 263) | |
496 | frag_header.priority = skb->priority - 256; | |
fe77d825 SE |
497 | else |
498 | frag_header.priority = 0; | |
c0f25c80 | 499 | |
8fdd0153 AQ |
500 | ether_addr_copy(frag_header.orig, primary_if->net_dev->dev_addr); |
501 | ether_addr_copy(frag_header.dest, orig_node->orig); | |
ee75ed88 MH |
502 | |
503 | /* Eat and send fragments from the tail of skb */ | |
504 | while (skb->len > max_fragment_size) { | |
51c6b429 LL |
505 | /* The initial check in this function should cover this case */ |
506 | if (unlikely(frag_header.no == BATADV_FRAG_MAX_FRAGMENTS - 1)) { | |
507 | ret = -EINVAL; | |
508 | goto put_primary_if; | |
509 | } | |
510 | ||
c5cbfc87 | 511 | skb_fragment = batadv_frag_create(net_dev, skb, &frag_header, |
1c2bcc76 | 512 | max_fragment_size); |
8def0be8 SE |
513 | if (!skb_fragment) { |
514 | ret = -ENOMEM; | |
4ea33ef0 | 515 | goto put_primary_if; |
8def0be8 | 516 | } |
ee75ed88 MH |
517 | |
518 | batadv_inc_counter(bat_priv, BATADV_CNT_FRAG_TX); | |
519 | batadv_add_counter(bat_priv, BATADV_CNT_FRAG_TX_BYTES, | |
520 | skb_fragment->len + ETH_HLEN); | |
f50ca95a AQ |
521 | ret = batadv_send_unicast_skb(skb_fragment, neigh_node); |
522 | if (ret != NET_XMIT_SUCCESS) { | |
8def0be8 | 523 | ret = NET_XMIT_DROP; |
4ea33ef0 | 524 | goto put_primary_if; |
f50ca95a AQ |
525 | } |
526 | ||
ee75ed88 | 527 | frag_header.no++; |
ee75ed88 MH |
528 | } |
529 | ||
992b03b8 SE |
530 | /* make sure that there is at least enough head for the fragmentation |
531 | * and ethernet headers | |
532 | */ | |
533 | ret = skb_cow_head(skb, ETH_HLEN + header_size); | |
534 | if (ret < 0) | |
4ea33ef0 | 535 | goto put_primary_if; |
ee75ed88 | 536 | |
992b03b8 | 537 | skb_push(skb, header_size); |
ee75ed88 MH |
538 | memcpy(skb->data, &frag_header, header_size); |
539 | ||
540 | /* Send the last fragment */ | |
541 | batadv_inc_counter(bat_priv, BATADV_CNT_FRAG_TX); | |
542 | batadv_add_counter(bat_priv, BATADV_CNT_FRAG_TX_BYTES, | |
543 | skb->len + ETH_HLEN); | |
f50ca95a | 544 | ret = batadv_send_unicast_skb(skb, neigh_node); |
8def0be8 SE |
545 | /* skb was consumed */ |
546 | skb = NULL; | |
ee75ed88 | 547 | |
8def0be8 SE |
548 | put_primary_if: |
549 | batadv_hardif_put(primary_if); | |
550 | free_skb: | |
551 | kfree_skb(skb); | |
be181015 AQ |
552 | |
553 | return ret; | |
ee75ed88 | 554 | } |