batman-adv: Don't break statements after assignment operator
[deliverable/linux.git] / net / batman-adv / unicast.c
CommitLineData
9cfc7bd6 1/* Copyright (C) 2010-2012 B.A.T.M.A.N. contributors:
c6c8fea2
SE
2 *
3 * Andreas Langer
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
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
17 * 02110-1301, USA
c6c8fea2
SE
18 */
19
20#include "main.h"
21#include "unicast.h"
22#include "send.h"
23#include "soft-interface.h"
24#include "gateway_client.h"
25#include "originator.h"
26#include "hash.h"
27#include "translation-table.h"
28#include "routing.h"
29#include "hard-interface.h"
30
31
0354440b
SE
32static struct sk_buff *
33batadv_frag_merge_packet(struct list_head *head,
56303d34 34 struct batadv_frag_packet_list_entry *tfp,
0354440b 35 struct sk_buff *skb)
c6c8fea2 36{
96412690 37 struct batadv_unicast_frag_packet *up;
c6c8fea2 38 struct sk_buff *tmp_skb;
96412690 39 struct batadv_unicast_packet *unicast_packet;
704509b8
SE
40 int hdr_len = sizeof(*unicast_packet);
41 int uni_diff = sizeof(*up) - hdr_len;
c6c8fea2 42
96412690 43 up = (struct batadv_unicast_frag_packet *)skb->data;
c6c8fea2 44 /* set skb to the first part and tmp_skb to the second part */
acd34afa 45 if (up->flags & BATADV_UNI_FRAG_HEAD) {
c6c8fea2
SE
46 tmp_skb = tfp->skb;
47 } else {
48 tmp_skb = skb;
49 skb = tfp->skb;
50 }
51
531c9da8
SE
52 if (skb_linearize(skb) < 0 || skb_linearize(tmp_skb) < 0)
53 goto err;
54
704509b8 55 skb_pull(tmp_skb, sizeof(*up));
531c9da8
SE
56 if (pskb_expand_head(skb, 0, tmp_skb->len, GFP_ATOMIC) < 0)
57 goto err;
c6c8fea2
SE
58
59 /* move free entry to end */
60 tfp->skb = NULL;
61 tfp->seqno = 0;
62 list_move_tail(&tfp->list, head);
63
64 memcpy(skb_put(skb, tmp_skb->len), tmp_skb->data, tmp_skb->len);
65 kfree_skb(tmp_skb);
66
67 memmove(skb->data + uni_diff, skb->data, hdr_len);
96412690
SE
68 unicast_packet = (struct batadv_unicast_packet *)skb_pull(skb,
69 uni_diff);
acd34afa 70 unicast_packet->header.packet_type = BATADV_UNICAST;
c6c8fea2
SE
71
72 return skb;
531c9da8
SE
73
74err:
75 /* free buffered skb, skb will be freed later */
76 kfree_skb(tfp->skb);
77 return NULL;
c6c8fea2
SE
78}
79
0354440b
SE
80static void batadv_frag_create_entry(struct list_head *head,
81 struct sk_buff *skb)
c6c8fea2 82{
56303d34 83 struct batadv_frag_packet_list_entry *tfp;
96412690
SE
84 struct batadv_unicast_frag_packet *up;
85
86 up = (struct batadv_unicast_frag_packet *)skb->data;
c6c8fea2
SE
87
88 /* free and oldest packets stand at the end */
89 tfp = list_entry((head)->prev, typeof(*tfp), list);
90 kfree_skb(tfp->skb);
91
92 tfp->seqno = ntohs(up->seqno);
93 tfp->skb = skb;
94 list_move(&tfp->list, head);
95 return;
96}
97
0354440b 98static int batadv_frag_create_buffer(struct list_head *head)
c6c8fea2
SE
99{
100 int i;
56303d34 101 struct batadv_frag_packet_list_entry *tfp;
c6c8fea2 102
4d5d2db8 103 for (i = 0; i < BATADV_FRAG_BUFFER_SIZE; i++) {
704509b8 104 tfp = kmalloc(sizeof(*tfp), GFP_ATOMIC);
c6c8fea2 105 if (!tfp) {
88ed1e77 106 batadv_frag_list_free(head);
c6c8fea2
SE
107 return -ENOMEM;
108 }
109 tfp->skb = NULL;
110 tfp->seqno = 0;
111 INIT_LIST_HEAD(&tfp->list);
112 list_add(&tfp->list, head);
113 }
114
115 return 0;
116}
117
56303d34 118static struct batadv_frag_packet_list_entry *
0354440b 119batadv_frag_search_packet(struct list_head *head,
96412690 120 const struct batadv_unicast_frag_packet *up)
c6c8fea2 121{
56303d34 122 struct batadv_frag_packet_list_entry *tfp;
96412690 123 struct batadv_unicast_frag_packet *tmp_up = NULL;
bbb1f90e 124 int is_head_tmp, is_head;
c6c8fea2
SE
125 uint16_t search_seqno;
126
acd34afa 127 if (up->flags & BATADV_UNI_FRAG_HEAD)
c6c8fea2
SE
128 search_seqno = ntohs(up->seqno)+1;
129 else
130 search_seqno = ntohs(up->seqno)-1;
131
bbb1f90e
SE
132 is_head = !!(up->flags & BATADV_UNI_FRAG_HEAD);
133
c6c8fea2
SE
134 list_for_each_entry(tfp, head, list) {
135
136 if (!tfp->skb)
137 continue;
138
139 if (tfp->seqno == ntohs(up->seqno))
140 goto mov_tail;
141
96412690 142 tmp_up = (struct batadv_unicast_frag_packet *)tfp->skb->data;
c6c8fea2
SE
143
144 if (tfp->seqno == search_seqno) {
bbb1f90e
SE
145 is_head_tmp = !!(tmp_up->flags & BATADV_UNI_FRAG_HEAD);
146 if (is_head_tmp != is_head)
c6c8fea2
SE
147 return tfp;
148 else
149 goto mov_tail;
150 }
151 }
152 return NULL;
153
154mov_tail:
155 list_move_tail(&tfp->list, head);
156 return NULL;
157}
158
88ed1e77 159void batadv_frag_list_free(struct list_head *head)
c6c8fea2 160{
56303d34 161 struct batadv_frag_packet_list_entry *pf, *tmp_pf;
c6c8fea2
SE
162
163 if (!list_empty(head)) {
164
165 list_for_each_entry_safe(pf, tmp_pf, head, list) {
166 kfree_skb(pf->skb);
167 list_del(&pf->list);
168 kfree(pf);
169 }
170 }
171 return;
172}
173
174/* frag_reassemble_skb():
175 * returns NET_RX_DROP if the operation failed - skb is left intact
176 * returns NET_RX_SUCCESS if the fragment was buffered (skb_new will be NULL)
177 * or the skb could be reassembled (skb_new will point to the new packet and
178 * skb was freed)
179 */
56303d34
SE
180int batadv_frag_reassemble_skb(struct sk_buff *skb,
181 struct batadv_priv *bat_priv,
88ed1e77 182 struct sk_buff **new_skb)
c6c8fea2 183{
56303d34
SE
184 struct batadv_orig_node *orig_node;
185 struct batadv_frag_packet_list_entry *tmp_frag_entry;
c6c8fea2 186 int ret = NET_RX_DROP;
96412690 187 struct batadv_unicast_frag_packet *unicast_packet;
c6c8fea2 188
96412690 189 unicast_packet = (struct batadv_unicast_frag_packet *)skb->data;
c6c8fea2 190 *new_skb = NULL;
c6c8fea2 191
da641193 192 orig_node = batadv_orig_hash_find(bat_priv, unicast_packet->orig);
7aadf889 193 if (!orig_node)
c6c8fea2 194 goto out;
c6c8fea2
SE
195
196 orig_node->last_frag_packet = jiffies;
197
198 if (list_empty(&orig_node->frag_list) &&
0354440b 199 batadv_frag_create_buffer(&orig_node->frag_list)) {
c6c8fea2
SE
200 pr_debug("couldn't create frag buffer\n");
201 goto out;
202 }
203
0354440b
SE
204 tmp_frag_entry = batadv_frag_search_packet(&orig_node->frag_list,
205 unicast_packet);
c6c8fea2
SE
206
207 if (!tmp_frag_entry) {
0354440b 208 batadv_frag_create_entry(&orig_node->frag_list, skb);
c6c8fea2
SE
209 ret = NET_RX_SUCCESS;
210 goto out;
211 }
212
0354440b
SE
213 *new_skb = batadv_frag_merge_packet(&orig_node->frag_list,
214 tmp_frag_entry, skb);
c6c8fea2
SE
215 /* if not, merge failed */
216 if (*new_skb)
217 ret = NET_RX_SUCCESS;
c6c8fea2 218
7aadf889
ML
219out:
220 if (orig_node)
7d211efc 221 batadv_orig_node_free_ref(orig_node);
c6c8fea2
SE
222 return ret;
223}
224
56303d34
SE
225int batadv_frag_send_skb(struct sk_buff *skb, struct batadv_priv *bat_priv,
226 struct batadv_hard_iface *hard_iface,
227 const uint8_t dstaddr[])
c6c8fea2 228{
96412690 229 struct batadv_unicast_packet tmp_uc, *unicast_packet;
56303d34 230 struct batadv_hard_iface *primary_if;
c6c8fea2 231 struct sk_buff *frag_skb;
96412690 232 struct batadv_unicast_frag_packet *frag1, *frag2;
704509b8
SE
233 int uc_hdr_len = sizeof(*unicast_packet);
234 int ucf_hdr_len = sizeof(*frag1);
5c77d8bb 235 int data_len = skb->len - uc_hdr_len;
32ae9b22 236 int large_tail = 0, ret = NET_RX_DROP;
c2f7f0e7 237 uint16_t seqno;
c6c8fea2 238
e5d89254 239 primary_if = batadv_primary_if_get_selected(bat_priv);
32ae9b22 240 if (!primary_if)
c6c8fea2
SE
241 goto dropped;
242
ed7809d9
JJ
243 frag_skb = dev_alloc_skb(data_len - (data_len / 2) + ucf_hdr_len);
244 if (!frag_skb)
245 goto dropped;
5c77d8bb 246 skb_reserve(frag_skb, ucf_hdr_len);
c6c8fea2 247
96412690 248 unicast_packet = (struct batadv_unicast_packet *)skb->data;
c6c8fea2 249 memcpy(&tmp_uc, unicast_packet, uc_hdr_len);
5c77d8bb 250 skb_split(skb, frag_skb, data_len / 2 + uc_hdr_len);
c6c8fea2 251
04b482a2
SE
252 if (batadv_skb_head_push(skb, ucf_hdr_len - uc_hdr_len) < 0 ||
253 batadv_skb_head_push(frag_skb, ucf_hdr_len) < 0)
c6c8fea2
SE
254 goto drop_frag;
255
96412690
SE
256 frag1 = (struct batadv_unicast_frag_packet *)skb->data;
257 frag2 = (struct batadv_unicast_frag_packet *)frag_skb->data;
c6c8fea2 258
704509b8 259 memcpy(frag1, &tmp_uc, sizeof(tmp_uc));
c6c8fea2 260
76543d14 261 frag1->header.ttl--;
7e071c79 262 frag1->header.version = BATADV_COMPAT_VERSION;
acd34afa 263 frag1->header.packet_type = BATADV_UNICAST_FRAG;
c6c8fea2 264
32ae9b22 265 memcpy(frag1->orig, primary_if->net_dev->dev_addr, ETH_ALEN);
704509b8 266 memcpy(frag2, frag1, sizeof(*frag2));
c6c8fea2 267
ae361ce1 268 if (data_len & 1)
acd34afa 269 large_tail = BATADV_UNI_FRAG_LARGETAIL;
ae361ce1 270
acd34afa 271 frag1->flags = BATADV_UNI_FRAG_HEAD | large_tail;
ae361ce1 272 frag2->flags = large_tail;
c6c8fea2 273
e6c10f43 274 seqno = atomic_add_return(2, &hard_iface->frag_seqno);
c2f7f0e7
SE
275 frag1->seqno = htons(seqno - 1);
276 frag2->seqno = htons(seqno);
c6c8fea2 277
9455e34c
SE
278 batadv_send_skb_packet(skb, hard_iface, dstaddr);
279 batadv_send_skb_packet(frag_skb, hard_iface, dstaddr);
32ae9b22
ML
280 ret = NET_RX_SUCCESS;
281 goto out;
c6c8fea2
SE
282
283drop_frag:
284 kfree_skb(frag_skb);
285dropped:
286 kfree_skb(skb);
32ae9b22
ML
287out:
288 if (primary_if)
e5d89254 289 batadv_hardif_free_ref(primary_if);
32ae9b22 290 return ret;
c6c8fea2
SE
291}
292
56303d34 293int batadv_unicast_send_skb(struct sk_buff *skb, struct batadv_priv *bat_priv)
c6c8fea2
SE
294{
295 struct ethhdr *ethhdr = (struct ethhdr *)skb->data;
96412690 296 struct batadv_unicast_packet *unicast_packet;
56303d34
SE
297 struct batadv_orig_node *orig_node;
298 struct batadv_neigh_node *neigh_node;
c6c8fea2 299 int data_len = skb->len;
44524fcd 300 int ret = 1;
0aca2369 301 unsigned int dev_mtu;
c6c8fea2
SE
302
303 /* get routing information */
43c70ad5 304 if (is_multicast_ether_addr(ethhdr->h_dest)) {
7cf06bc6 305 orig_node = batadv_gw_get_selected_orig(bat_priv);
43c70ad5 306 if (orig_node)
44524fcd
ML
307 goto find_router;
308 }
c6c8fea2 309
3d393e47 310 /* check for tt host - increases orig_node refcount.
9cfc7bd6
SE
311 * returns NULL in case of AP isolation
312 */
08c36d3e
SE
313 orig_node = batadv_transtable_search(bat_priv, ethhdr->h_source,
314 ethhdr->h_dest);
56303d34 315
44524fcd 316find_router:
9cfc7bd6 317 /* find_router():
d0072609
ML
318 * - if orig_node is NULL it returns NULL
319 * - increases neigh_nodes refcount if found.
320 */
30d3c511 321 neigh_node = batadv_find_router(bat_priv, orig_node, NULL);
56303d34 322
44524fcd 323 if (!neigh_node)
d0072609 324 goto out;
c6c8fea2 325
04b482a2 326 if (batadv_skb_head_push(skb, sizeof(*unicast_packet)) < 0)
d0072609 327 goto out;
c6c8fea2 328
96412690 329 unicast_packet = (struct batadv_unicast_packet *)skb->data;
c6c8fea2 330
7e071c79 331 unicast_packet->header.version = BATADV_COMPAT_VERSION;
c6c8fea2 332 /* batman packet type: unicast */
acd34afa 333 unicast_packet->header.packet_type = BATADV_UNICAST;
c6c8fea2 334 /* set unicast ttl */
42d0b044 335 unicast_packet->header.ttl = BATADV_TTL;
c6c8fea2
SE
336 /* copy the destination for faster routing */
337 memcpy(unicast_packet->dest, orig_node->orig, ETH_ALEN);
a73105b8 338 /* set the destination tt version number */
bbb1f90e 339 unicast_packet->ttvn = (uint8_t)atomic_read(&orig_node->last_ttvn);
c6c8fea2 340
3275e7cc
AQ
341 /* inform the destination node that we are still missing a correct route
342 * for this client. The destination will receive this packet and will
343 * try to reroute it because the ttvn contained in the header is less
344 * than the current one
345 */
08c36d3e 346 if (batadv_tt_global_client_is_roaming(bat_priv, ethhdr->h_dest))
3275e7cc
AQ
347 unicast_packet->ttvn = unicast_packet->ttvn - 1;
348
0aca2369 349 dev_mtu = neigh_node->if_incoming->net_dev->mtu;
c6c8fea2 350 if (atomic_read(&bat_priv->fragmentation) &&
0aca2369 351 data_len + sizeof(*unicast_packet) > dev_mtu) {
c6c8fea2 352 /* send frag skb decreases ttl */
76543d14 353 unicast_packet->header.ttl++;
88ed1e77
SE
354 ret = batadv_frag_send_skb(skb, bat_priv,
355 neigh_node->if_incoming,
356 neigh_node->addr);
44524fcd 357 goto out;
c6c8fea2 358 }
c6c8fea2 359
9455e34c 360 batadv_send_skb_packet(skb, neigh_node->if_incoming, neigh_node->addr);
44524fcd
ML
361 ret = 0;
362 goto out;
c6c8fea2 363
44524fcd
ML
364out:
365 if (neigh_node)
7d211efc 366 batadv_neigh_node_free_ref(neigh_node);
44524fcd 367 if (orig_node)
7d211efc 368 batadv_orig_node_free_ref(orig_node);
44524fcd
ML
369 if (ret == 1)
370 kfree_skb(skb);
371 return ret;
c6c8fea2 372}
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