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c6c8fea2 | 1 | /* |
567db7b0 | 2 | * Copyright (C) 2010-2012 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 | ||
34 | static 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; | |
704509b8 SE |
42 | int hdr_len = sizeof(*unicast_packet); |
43 | int uni_diff = sizeof(*up) - hdr_len; | |
c6c8fea2 SE |
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 | ||
704509b8 | 56 | skb_pull(tmp_skb, sizeof(*up)); |
531c9da8 SE |
57 | if (pskb_expand_head(skb, 0, tmp_skb->len, GFP_ATOMIC) < 0) |
58 | goto err; | |
c6c8fea2 SE |
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); | |
40e0c4f5 | 69 | unicast_packet = (struct unicast_packet *)skb_pull(skb, uni_diff); |
76543d14 | 70 | unicast_packet->header.packet_type = BAT_UNICAST; |
c6c8fea2 SE |
71 | |
72 | return skb; | |
531c9da8 SE |
73 | |
74 | err: | |
75 | /* free buffered skb, skb will be freed later */ | |
76 | kfree_skb(tfp->skb); | |
77 | return NULL; | |
c6c8fea2 SE |
78 | } |
79 | ||
80 | static 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 | ||
96 | static 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++) { | |
704509b8 | 102 | tfp = kmalloc(sizeof(*tfp), GFP_ATOMIC); |
c6c8fea2 SE |
103 | if (!tfp) { |
104 | frag_list_free(head); | |
105 | return -ENOMEM; | |
106 | } | |
107 | tfp->skb = NULL; | |
108 | tfp->seqno = 0; | |
109 | INIT_LIST_HEAD(&tfp->list); | |
110 | list_add(&tfp->list, head); | |
111 | } | |
112 | ||
113 | return 0; | |
114 | } | |
115 | ||
116 | static struct frag_packet_list_entry *frag_search_packet(struct list_head *head, | |
747e4221 | 117 | const struct unicast_frag_packet *up) |
c6c8fea2 SE |
118 | { |
119 | struct frag_packet_list_entry *tfp; | |
120 | struct unicast_frag_packet *tmp_up = NULL; | |
121 | uint16_t search_seqno; | |
122 | ||
123 | if (up->flags & UNI_FRAG_HEAD) | |
124 | search_seqno = ntohs(up->seqno)+1; | |
125 | else | |
126 | search_seqno = ntohs(up->seqno)-1; | |
127 | ||
128 | list_for_each_entry(tfp, head, list) { | |
129 | ||
130 | if (!tfp->skb) | |
131 | continue; | |
132 | ||
133 | if (tfp->seqno == ntohs(up->seqno)) | |
134 | goto mov_tail; | |
135 | ||
136 | tmp_up = (struct unicast_frag_packet *)tfp->skb->data; | |
137 | ||
138 | if (tfp->seqno == search_seqno) { | |
139 | ||
140 | if ((tmp_up->flags & UNI_FRAG_HEAD) != | |
141 | (up->flags & UNI_FRAG_HEAD)) | |
142 | return tfp; | |
143 | else | |
144 | goto mov_tail; | |
145 | } | |
146 | } | |
147 | return NULL; | |
148 | ||
149 | mov_tail: | |
150 | list_move_tail(&tfp->list, head); | |
151 | return NULL; | |
152 | } | |
153 | ||
154 | void frag_list_free(struct list_head *head) | |
155 | { | |
156 | struct frag_packet_list_entry *pf, *tmp_pf; | |
157 | ||
158 | if (!list_empty(head)) { | |
159 | ||
160 | list_for_each_entry_safe(pf, tmp_pf, head, list) { | |
161 | kfree_skb(pf->skb); | |
162 | list_del(&pf->list); | |
163 | kfree(pf); | |
164 | } | |
165 | } | |
166 | return; | |
167 | } | |
168 | ||
169 | /* frag_reassemble_skb(): | |
170 | * returns NET_RX_DROP if the operation failed - skb is left intact | |
171 | * returns NET_RX_SUCCESS if the fragment was buffered (skb_new will be NULL) | |
172 | * or the skb could be reassembled (skb_new will point to the new packet and | |
173 | * skb was freed) | |
174 | */ | |
175 | int frag_reassemble_skb(struct sk_buff *skb, struct bat_priv *bat_priv, | |
176 | struct sk_buff **new_skb) | |
177 | { | |
178 | struct orig_node *orig_node; | |
179 | struct frag_packet_list_entry *tmp_frag_entry; | |
180 | int ret = NET_RX_DROP; | |
181 | struct unicast_frag_packet *unicast_packet = | |
182 | (struct unicast_frag_packet *)skb->data; | |
183 | ||
184 | *new_skb = NULL; | |
c6c8fea2 | 185 | |
7aadf889 ML |
186 | orig_node = orig_hash_find(bat_priv, unicast_packet->orig); |
187 | if (!orig_node) | |
c6c8fea2 | 188 | goto out; |
c6c8fea2 SE |
189 | |
190 | orig_node->last_frag_packet = jiffies; | |
191 | ||
192 | if (list_empty(&orig_node->frag_list) && | |
193 | frag_create_buffer(&orig_node->frag_list)) { | |
194 | pr_debug("couldn't create frag buffer\n"); | |
195 | goto out; | |
196 | } | |
197 | ||
198 | tmp_frag_entry = frag_search_packet(&orig_node->frag_list, | |
199 | unicast_packet); | |
200 | ||
201 | if (!tmp_frag_entry) { | |
202 | frag_create_entry(&orig_node->frag_list, skb); | |
203 | ret = NET_RX_SUCCESS; | |
204 | goto out; | |
205 | } | |
206 | ||
207 | *new_skb = frag_merge_packet(&orig_node->frag_list, tmp_frag_entry, | |
208 | skb); | |
209 | /* if not, merge failed */ | |
210 | if (*new_skb) | |
211 | ret = NET_RX_SUCCESS; | |
c6c8fea2 | 212 | |
7aadf889 ML |
213 | out: |
214 | if (orig_node) | |
7b36e8ee | 215 | orig_node_free_ref(orig_node); |
c6c8fea2 SE |
216 | return ret; |
217 | } | |
218 | ||
219 | int frag_send_skb(struct sk_buff *skb, struct bat_priv *bat_priv, | |
747e4221 | 220 | struct hard_iface *hard_iface, const uint8_t dstaddr[]) |
c6c8fea2 SE |
221 | { |
222 | struct unicast_packet tmp_uc, *unicast_packet; | |
32ae9b22 | 223 | struct hard_iface *primary_if; |
c6c8fea2 SE |
224 | struct sk_buff *frag_skb; |
225 | struct unicast_frag_packet *frag1, *frag2; | |
704509b8 SE |
226 | int uc_hdr_len = sizeof(*unicast_packet); |
227 | int ucf_hdr_len = sizeof(*frag1); | |
5c77d8bb | 228 | int data_len = skb->len - uc_hdr_len; |
32ae9b22 | 229 | int large_tail = 0, ret = NET_RX_DROP; |
c2f7f0e7 | 230 | uint16_t seqno; |
c6c8fea2 | 231 | |
32ae9b22 ML |
232 | primary_if = primary_if_get_selected(bat_priv); |
233 | if (!primary_if) | |
c6c8fea2 SE |
234 | goto dropped; |
235 | ||
ed7809d9 JJ |
236 | frag_skb = dev_alloc_skb(data_len - (data_len / 2) + ucf_hdr_len); |
237 | if (!frag_skb) | |
238 | goto dropped; | |
5c77d8bb | 239 | skb_reserve(frag_skb, ucf_hdr_len); |
c6c8fea2 | 240 | |
40e0c4f5 | 241 | unicast_packet = (struct unicast_packet *)skb->data; |
c6c8fea2 | 242 | memcpy(&tmp_uc, unicast_packet, uc_hdr_len); |
5c77d8bb | 243 | skb_split(skb, frag_skb, data_len / 2 + uc_hdr_len); |
c6c8fea2 SE |
244 | |
245 | if (my_skb_head_push(skb, ucf_hdr_len - uc_hdr_len) < 0 || | |
246 | my_skb_head_push(frag_skb, ucf_hdr_len) < 0) | |
247 | goto drop_frag; | |
248 | ||
249 | frag1 = (struct unicast_frag_packet *)skb->data; | |
250 | frag2 = (struct unicast_frag_packet *)frag_skb->data; | |
251 | ||
704509b8 | 252 | memcpy(frag1, &tmp_uc, sizeof(tmp_uc)); |
c6c8fea2 | 253 | |
76543d14 SE |
254 | frag1->header.ttl--; |
255 | frag1->header.version = COMPAT_VERSION; | |
256 | frag1->header.packet_type = BAT_UNICAST_FRAG; | |
c6c8fea2 | 257 | |
32ae9b22 | 258 | memcpy(frag1->orig, primary_if->net_dev->dev_addr, ETH_ALEN); |
704509b8 | 259 | memcpy(frag2, frag1, sizeof(*frag2)); |
c6c8fea2 | 260 | |
ae361ce1 SE |
261 | if (data_len & 1) |
262 | large_tail = UNI_FRAG_LARGETAIL; | |
263 | ||
264 | frag1->flags = UNI_FRAG_HEAD | large_tail; | |
265 | frag2->flags = large_tail; | |
c6c8fea2 | 266 | |
e6c10f43 | 267 | seqno = atomic_add_return(2, &hard_iface->frag_seqno); |
c2f7f0e7 SE |
268 | frag1->seqno = htons(seqno - 1); |
269 | frag2->seqno = htons(seqno); | |
c6c8fea2 | 270 | |
e6c10f43 ML |
271 | send_skb_packet(skb, hard_iface, dstaddr); |
272 | send_skb_packet(frag_skb, hard_iface, dstaddr); | |
32ae9b22 ML |
273 | ret = NET_RX_SUCCESS; |
274 | goto out; | |
c6c8fea2 SE |
275 | |
276 | drop_frag: | |
277 | kfree_skb(frag_skb); | |
278 | dropped: | |
279 | kfree_skb(skb); | |
32ae9b22 ML |
280 | out: |
281 | if (primary_if) | |
282 | hardif_free_ref(primary_if); | |
283 | return ret; | |
c6c8fea2 SE |
284 | } |
285 | ||
286 | int unicast_send_skb(struct sk_buff *skb, struct bat_priv *bat_priv) | |
287 | { | |
288 | struct ethhdr *ethhdr = (struct ethhdr *)skb->data; | |
289 | struct unicast_packet *unicast_packet; | |
7b36e8ee | 290 | struct orig_node *orig_node; |
44524fcd | 291 | struct neigh_node *neigh_node; |
c6c8fea2 | 292 | int data_len = skb->len; |
44524fcd | 293 | int ret = 1; |
c6c8fea2 SE |
294 | |
295 | /* get routing information */ | |
43c70ad5 | 296 | if (is_multicast_ether_addr(ethhdr->h_dest)) { |
958ca598 | 297 | orig_node = gw_get_selected_orig(bat_priv); |
43c70ad5 | 298 | if (orig_node) |
44524fcd ML |
299 | goto find_router; |
300 | } | |
c6c8fea2 | 301 | |
3d393e47 AQ |
302 | /* check for tt host - increases orig_node refcount. |
303 | * returns NULL in case of AP isolation */ | |
304 | orig_node = transtable_search(bat_priv, ethhdr->h_source, | |
305 | ethhdr->h_dest); | |
c6c8fea2 | 306 | |
44524fcd | 307 | find_router: |
d0072609 ML |
308 | /** |
309 | * find_router(): | |
310 | * - if orig_node is NULL it returns NULL | |
311 | * - increases neigh_nodes refcount if found. | |
312 | */ | |
44524fcd | 313 | neigh_node = find_router(bat_priv, orig_node, NULL); |
c6c8fea2 | 314 | |
44524fcd | 315 | if (!neigh_node) |
d0072609 | 316 | goto out; |
c6c8fea2 | 317 | |
704509b8 | 318 | if (my_skb_head_push(skb, sizeof(*unicast_packet)) < 0) |
d0072609 | 319 | goto out; |
c6c8fea2 SE |
320 | |
321 | unicast_packet = (struct unicast_packet *)skb->data; | |
322 | ||
76543d14 | 323 | unicast_packet->header.version = COMPAT_VERSION; |
c6c8fea2 | 324 | /* batman packet type: unicast */ |
76543d14 | 325 | unicast_packet->header.packet_type = BAT_UNICAST; |
c6c8fea2 | 326 | /* set unicast ttl */ |
76543d14 | 327 | unicast_packet->header.ttl = TTL; |
c6c8fea2 SE |
328 | /* copy the destination for faster routing */ |
329 | memcpy(unicast_packet->dest, orig_node->orig, ETH_ALEN); | |
a73105b8 AQ |
330 | /* set the destination tt version number */ |
331 | unicast_packet->ttvn = | |
332 | (uint8_t)atomic_read(&orig_node->last_ttvn); | |
c6c8fea2 SE |
333 | |
334 | if (atomic_read(&bat_priv->fragmentation) && | |
704509b8 | 335 | data_len + sizeof(*unicast_packet) > |
d0072609 | 336 | neigh_node->if_incoming->net_dev->mtu) { |
c6c8fea2 | 337 | /* send frag skb decreases ttl */ |
76543d14 | 338 | unicast_packet->header.ttl++; |
d0072609 ML |
339 | ret = frag_send_skb(skb, bat_priv, |
340 | neigh_node->if_incoming, neigh_node->addr); | |
44524fcd | 341 | goto out; |
c6c8fea2 | 342 | } |
c6c8fea2 | 343 | |
d0072609 | 344 | send_skb_packet(skb, neigh_node->if_incoming, neigh_node->addr); |
44524fcd ML |
345 | ret = 0; |
346 | goto out; | |
c6c8fea2 | 347 | |
44524fcd ML |
348 | out: |
349 | if (neigh_node) | |
350 | neigh_node_free_ref(neigh_node); | |
351 | if (orig_node) | |
7b36e8ee | 352 | orig_node_free_ref(orig_node); |
44524fcd ML |
353 | if (ret == 1) |
354 | kfree_skb(skb); | |
355 | return ret; | |
c6c8fea2 | 356 | } |