batman-adv: Remove casts from type x to type x
[linux-2.6-block.git] / net / batman-adv / unicast.c
CommitLineData
c6c8fea2 1/*
64afe353 2 * Copyright (C) 2010-2011 B.A.T.M.A.N. contributors:
c6c8fea2
SE
3 *
4 * Andreas Langer
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of version 2 of the GNU General Public
8 * License as published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
18 * 02110-1301, USA
19 *
20 */
21
22#include "main.h"
23#include "unicast.h"
24#include "send.h"
25#include "soft-interface.h"
26#include "gateway_client.h"
27#include "originator.h"
28#include "hash.h"
29#include "translation-table.h"
30#include "routing.h"
31#include "hard-interface.h"
32
33
34static struct sk_buff *frag_merge_packet(struct list_head *head,
35 struct frag_packet_list_entry *tfp,
36 struct sk_buff *skb)
37{
38 struct unicast_frag_packet *up =
39 (struct unicast_frag_packet *)skb->data;
40 struct sk_buff *tmp_skb;
41 struct unicast_packet *unicast_packet;
14062064
ML
42 int hdr_len = sizeof(struct unicast_packet);
43 int uni_diff = sizeof(struct unicast_frag_packet) - hdr_len;
c6c8fea2
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44
45 /* set skb to the first part and tmp_skb to the second part */
46 if (up->flags & UNI_FRAG_HEAD) {
47 tmp_skb = tfp->skb;
48 } else {
49 tmp_skb = skb;
50 skb = tfp->skb;
51 }
52
531c9da8
SE
53 if (skb_linearize(skb) < 0 || skb_linearize(tmp_skb) < 0)
54 goto err;
55
c6c8fea2 56 skb_pull(tmp_skb, sizeof(struct unicast_frag_packet));
531c9da8
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57 if (pskb_expand_head(skb, 0, tmp_skb->len, GFP_ATOMIC) < 0)
58 goto err;
c6c8fea2
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59
60 /* move free entry to end */
61 tfp->skb = NULL;
62 tfp->seqno = 0;
63 list_move_tail(&tfp->list, head);
64
65 memcpy(skb_put(skb, tmp_skb->len), tmp_skb->data, tmp_skb->len);
66 kfree_skb(tmp_skb);
67
68 memmove(skb->data + uni_diff, skb->data, hdr_len);
69 unicast_packet = (struct unicast_packet *) skb_pull(skb, uni_diff);
70 unicast_packet->packet_type = BAT_UNICAST;
71
72 return skb;
531c9da8
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73
74err:
75 /* free buffered skb, skb will be freed later */
76 kfree_skb(tfp->skb);
77 return NULL;
c6c8fea2
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78}
79
80static void frag_create_entry(struct list_head *head, struct sk_buff *skb)
81{
82 struct frag_packet_list_entry *tfp;
83 struct unicast_frag_packet *up =
84 (struct unicast_frag_packet *)skb->data;
85
86 /* free and oldest packets stand at the end */
87 tfp = list_entry((head)->prev, typeof(*tfp), list);
88 kfree_skb(tfp->skb);
89
90 tfp->seqno = ntohs(up->seqno);
91 tfp->skb = skb;
92 list_move(&tfp->list, head);
93 return;
94}
95
96static int frag_create_buffer(struct list_head *head)
97{
98 int i;
99 struct frag_packet_list_entry *tfp;
100
101 for (i = 0; i < FRAG_BUFFER_SIZE; i++) {
102 tfp = kmalloc(sizeof(struct frag_packet_list_entry),
103 GFP_ATOMIC);
104 if (!tfp) {
105 frag_list_free(head);
106 return -ENOMEM;
107 }
108 tfp->skb = NULL;
109 tfp->seqno = 0;
110 INIT_LIST_HEAD(&tfp->list);
111 list_add(&tfp->list, head);
112 }
113
114 return 0;
115}
116
117static struct frag_packet_list_entry *frag_search_packet(struct list_head *head,
747e4221 118 const struct unicast_frag_packet *up)
c6c8fea2
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119{
120 struct frag_packet_list_entry *tfp;
121 struct unicast_frag_packet *tmp_up = NULL;
122 uint16_t search_seqno;
123
124 if (up->flags & UNI_FRAG_HEAD)
125 search_seqno = ntohs(up->seqno)+1;
126 else
127 search_seqno = ntohs(up->seqno)-1;
128
129 list_for_each_entry(tfp, head, list) {
130
131 if (!tfp->skb)
132 continue;
133
134 if (tfp->seqno == ntohs(up->seqno))
135 goto mov_tail;
136
137 tmp_up = (struct unicast_frag_packet *)tfp->skb->data;
138
139 if (tfp->seqno == search_seqno) {
140
141 if ((tmp_up->flags & UNI_FRAG_HEAD) !=
142 (up->flags & UNI_FRAG_HEAD))
143 return tfp;
144 else
145 goto mov_tail;
146 }
147 }
148 return NULL;
149
150mov_tail:
151 list_move_tail(&tfp->list, head);
152 return NULL;
153}
154
155void frag_list_free(struct list_head *head)
156{
157 struct frag_packet_list_entry *pf, *tmp_pf;
158
159 if (!list_empty(head)) {
160
161 list_for_each_entry_safe(pf, tmp_pf, head, list) {
162 kfree_skb(pf->skb);
163 list_del(&pf->list);
164 kfree(pf);
165 }
166 }
167 return;
168}
169
170/* frag_reassemble_skb():
171 * returns NET_RX_DROP if the operation failed - skb is left intact
172 * returns NET_RX_SUCCESS if the fragment was buffered (skb_new will be NULL)
173 * or the skb could be reassembled (skb_new will point to the new packet and
174 * skb was freed)
175 */
176int frag_reassemble_skb(struct sk_buff *skb, struct bat_priv *bat_priv,
177 struct sk_buff **new_skb)
178{
179 struct orig_node *orig_node;
180 struct frag_packet_list_entry *tmp_frag_entry;
181 int ret = NET_RX_DROP;
182 struct unicast_frag_packet *unicast_packet =
183 (struct unicast_frag_packet *)skb->data;
184
185 *new_skb = NULL;
c6c8fea2 186
7aadf889
ML
187 orig_node = orig_hash_find(bat_priv, unicast_packet->orig);
188 if (!orig_node)
c6c8fea2 189 goto out;
c6c8fea2
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190
191 orig_node->last_frag_packet = jiffies;
192
193 if (list_empty(&orig_node->frag_list) &&
194 frag_create_buffer(&orig_node->frag_list)) {
195 pr_debug("couldn't create frag buffer\n");
196 goto out;
197 }
198
199 tmp_frag_entry = frag_search_packet(&orig_node->frag_list,
200 unicast_packet);
201
202 if (!tmp_frag_entry) {
203 frag_create_entry(&orig_node->frag_list, skb);
204 ret = NET_RX_SUCCESS;
205 goto out;
206 }
207
208 *new_skb = frag_merge_packet(&orig_node->frag_list, tmp_frag_entry,
209 skb);
210 /* if not, merge failed */
211 if (*new_skb)
212 ret = NET_RX_SUCCESS;
c6c8fea2 213
7aadf889
ML
214out:
215 if (orig_node)
7b36e8ee 216 orig_node_free_ref(orig_node);
c6c8fea2
SE
217 return ret;
218}
219
220int frag_send_skb(struct sk_buff *skb, struct bat_priv *bat_priv,
747e4221 221 struct hard_iface *hard_iface, const uint8_t dstaddr[])
c6c8fea2
SE
222{
223 struct unicast_packet tmp_uc, *unicast_packet;
32ae9b22 224 struct hard_iface *primary_if;
c6c8fea2
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225 struct sk_buff *frag_skb;
226 struct unicast_frag_packet *frag1, *frag2;
227 int uc_hdr_len = sizeof(struct unicast_packet);
228 int ucf_hdr_len = sizeof(struct unicast_frag_packet);
5c77d8bb 229 int data_len = skb->len - uc_hdr_len;
32ae9b22 230 int large_tail = 0, ret = NET_RX_DROP;
c2f7f0e7 231 uint16_t seqno;
c6c8fea2 232
32ae9b22
ML
233 primary_if = primary_if_get_selected(bat_priv);
234 if (!primary_if)
c6c8fea2
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235 goto dropped;
236
ed7809d9
JJ
237 frag_skb = dev_alloc_skb(data_len - (data_len / 2) + ucf_hdr_len);
238 if (!frag_skb)
239 goto dropped;
5c77d8bb 240 skb_reserve(frag_skb, ucf_hdr_len);
c6c8fea2 241
ed7809d9 242 unicast_packet = (struct unicast_packet *) skb->data;
c6c8fea2 243 memcpy(&tmp_uc, unicast_packet, uc_hdr_len);
5c77d8bb 244 skb_split(skb, frag_skb, data_len / 2 + uc_hdr_len);
c6c8fea2
SE
245
246 if (my_skb_head_push(skb, ucf_hdr_len - uc_hdr_len) < 0 ||
247 my_skb_head_push(frag_skb, ucf_hdr_len) < 0)
248 goto drop_frag;
249
250 frag1 = (struct unicast_frag_packet *)skb->data;
251 frag2 = (struct unicast_frag_packet *)frag_skb->data;
252
253 memcpy(frag1, &tmp_uc, sizeof(struct unicast_packet));
254
255 frag1->ttl--;
256 frag1->version = COMPAT_VERSION;
257 frag1->packet_type = BAT_UNICAST_FRAG;
258
32ae9b22 259 memcpy(frag1->orig, primary_if->net_dev->dev_addr, ETH_ALEN);
c6c8fea2
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260 memcpy(frag2, frag1, sizeof(struct unicast_frag_packet));
261
ae361ce1
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262 if (data_len & 1)
263 large_tail = UNI_FRAG_LARGETAIL;
264
265 frag1->flags = UNI_FRAG_HEAD | large_tail;
266 frag2->flags = large_tail;
c6c8fea2 267
e6c10f43 268 seqno = atomic_add_return(2, &hard_iface->frag_seqno);
c2f7f0e7
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269 frag1->seqno = htons(seqno - 1);
270 frag2->seqno = htons(seqno);
c6c8fea2 271
e6c10f43
ML
272 send_skb_packet(skb, hard_iface, dstaddr);
273 send_skb_packet(frag_skb, hard_iface, dstaddr);
32ae9b22
ML
274 ret = NET_RX_SUCCESS;
275 goto out;
c6c8fea2
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276
277drop_frag:
278 kfree_skb(frag_skb);
279dropped:
280 kfree_skb(skb);
32ae9b22
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281out:
282 if (primary_if)
283 hardif_free_ref(primary_if);
284 return ret;
c6c8fea2
SE
285}
286
287int unicast_send_skb(struct sk_buff *skb, struct bat_priv *bat_priv)
288{
289 struct ethhdr *ethhdr = (struct ethhdr *)skb->data;
290 struct unicast_packet *unicast_packet;
7b36e8ee 291 struct orig_node *orig_node;
44524fcd 292 struct neigh_node *neigh_node;
c6c8fea2 293 int data_len = skb->len;
44524fcd 294 int ret = 1;
c6c8fea2
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295
296 /* get routing information */
43c70ad5 297 if (is_multicast_ether_addr(ethhdr->h_dest)) {
958ca598 298 orig_node = gw_get_selected_orig(bat_priv);
43c70ad5 299 if (orig_node)
44524fcd
ML
300 goto find_router;
301 }
c6c8fea2 302
2dafb49d 303 /* check for tt host - increases orig_node refcount */
44524fcd 304 orig_node = transtable_search(bat_priv, ethhdr->h_dest);
c6c8fea2 305
44524fcd 306find_router:
d0072609
ML
307 /**
308 * find_router():
309 * - if orig_node is NULL it returns NULL
310 * - increases neigh_nodes refcount if found.
311 */
44524fcd 312 neigh_node = find_router(bat_priv, orig_node, NULL);
c6c8fea2 313
44524fcd 314 if (!neigh_node)
d0072609 315 goto out;
c6c8fea2 316
c6c8fea2 317 if (my_skb_head_push(skb, sizeof(struct unicast_packet)) < 0)
d0072609 318 goto out;
c6c8fea2
SE
319
320 unicast_packet = (struct unicast_packet *)skb->data;
321
322 unicast_packet->version = COMPAT_VERSION;
323 /* batman packet type: unicast */
324 unicast_packet->packet_type = BAT_UNICAST;
325 /* set unicast ttl */
326 unicast_packet->ttl = TTL;
327 /* copy the destination for faster routing */
328 memcpy(unicast_packet->dest, orig_node->orig, ETH_ALEN);
329
330 if (atomic_read(&bat_priv->fragmentation) &&
331 data_len + sizeof(struct unicast_packet) >
d0072609 332 neigh_node->if_incoming->net_dev->mtu) {
c6c8fea2
SE
333 /* send frag skb decreases ttl */
334 unicast_packet->ttl++;
d0072609
ML
335 ret = frag_send_skb(skb, bat_priv,
336 neigh_node->if_incoming, neigh_node->addr);
44524fcd 337 goto out;
c6c8fea2 338 }
c6c8fea2 339
d0072609 340 send_skb_packet(skb, neigh_node->if_incoming, neigh_node->addr);
44524fcd
ML
341 ret = 0;
342 goto out;
c6c8fea2 343
44524fcd
ML
344out:
345 if (neigh_node)
346 neigh_node_free_ref(neigh_node);
347 if (orig_node)
7b36e8ee 348 orig_node_free_ref(orig_node);
44524fcd
ML
349 if (ret == 1)
350 kfree_skb(skb);
351 return ret;
c6c8fea2 352}