1 /* Copyright (C) 2007-2014 B.A.T.M.A.N. contributors:
2 *
3 * Marek Lindner
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, see <http://www.gnu.org/licenses/>.
16 */
17
18 #include "main.h"
19 #include <linux/debugfs.h>
20 #include <linux/slab.h>
21 #include "icmp_socket.h"
22 #include "send.h"
23 #include "hash.h"
24 #include "originator.h"
25 #include "hard-interface.h"
26
27 static struct batadv_socket_client *batadv_socket_client_hash[256];
28
29 static void batadv_socket_add_packet(struct batadv_socket_client *socket_client,
30 struct batadv_icmp_header *icmph,
31 size_t icmp_len);
32
batadv_socket_init(void)33 void batadv_socket_init(void)
34 {
35 memset(batadv_socket_client_hash, 0, sizeof(batadv_socket_client_hash));
36 }
37
batadv_socket_open(struct inode * inode,struct file * file)38 static int batadv_socket_open(struct inode *inode, struct file *file)
39 {
40 unsigned int i;
41 struct batadv_socket_client *socket_client;
42
43 if (!try_module_get(THIS_MODULE))
44 return -EBUSY;
45
46 nonseekable_open(inode, file);
47
48 socket_client = kmalloc(sizeof(*socket_client), GFP_KERNEL);
49 if (!socket_client) {
50 module_put(THIS_MODULE);
51 return -ENOMEM;
52 }
53
54 for (i = 0; i < ARRAY_SIZE(batadv_socket_client_hash); i++) {
55 if (!batadv_socket_client_hash[i]) {
56 batadv_socket_client_hash[i] = socket_client;
57 break;
58 }
59 }
60
61 if (i == ARRAY_SIZE(batadv_socket_client_hash)) {
62 pr_err("Error - can't add another packet client: maximum number of clients reached\n");
63 kfree(socket_client);
64 module_put(THIS_MODULE);
65 return -EXFULL;
66 }
67
68 INIT_LIST_HEAD(&socket_client->queue_list);
69 socket_client->queue_len = 0;
70 socket_client->index = i;
71 socket_client->bat_priv = inode->i_private;
72 spin_lock_init(&socket_client->lock);
73 init_waitqueue_head(&socket_client->queue_wait);
74
75 file->private_data = socket_client;
76
77 return 0;
78 }
79
batadv_socket_release(struct inode * inode,struct file * file)80 static int batadv_socket_release(struct inode *inode, struct file *file)
81 {
82 struct batadv_socket_client *socket_client = file->private_data;
83 struct batadv_socket_packet *socket_packet;
84 struct list_head *list_pos, *list_pos_tmp;
85
86 spin_lock_bh(&socket_client->lock);
87
88 /* for all packets in the queue ... */
89 list_for_each_safe(list_pos, list_pos_tmp, &socket_client->queue_list) {
90 socket_packet = list_entry(list_pos,
91 struct batadv_socket_packet, list);
92
93 list_del(list_pos);
94 kfree(socket_packet);
95 }
96
97 batadv_socket_client_hash[socket_client->index] = NULL;
98 spin_unlock_bh(&socket_client->lock);
99
100 kfree(socket_client);
101 module_put(THIS_MODULE);
102
103 return 0;
104 }
105
batadv_socket_read(struct file * file,char __user * buf,size_t count,loff_t * ppos)106 static ssize_t batadv_socket_read(struct file *file, char __user *buf,
107 size_t count, loff_t *ppos)
108 {
109 struct batadv_socket_client *socket_client = file->private_data;
110 struct batadv_socket_packet *socket_packet;
111 size_t packet_len;
112 int error;
113
114 if ((file->f_flags & O_NONBLOCK) && (socket_client->queue_len == 0))
115 return -EAGAIN;
116
117 if ((!buf) || (count < sizeof(struct batadv_icmp_packet)))
118 return -EINVAL;
119
120 if (!access_ok(VERIFY_WRITE, buf, count))
121 return -EFAULT;
122
123 error = wait_event_interruptible(socket_client->queue_wait,
124 socket_client->queue_len);
125
126 if (error)
127 return error;
128
129 spin_lock_bh(&socket_client->lock);
130
131 socket_packet = list_first_entry(&socket_client->queue_list,
132 struct batadv_socket_packet, list);
133 list_del(&socket_packet->list);
134 socket_client->queue_len--;
135
136 spin_unlock_bh(&socket_client->lock);
137
138 packet_len = min(count, socket_packet->icmp_len);
139 error = copy_to_user(buf, &socket_packet->icmp_packet, packet_len);
140
141 kfree(socket_packet);
142
143 if (error)
144 return -EFAULT;
145
146 return packet_len;
147 }
148
batadv_socket_write(struct file * file,const char __user * buff,size_t len,loff_t * off)149 static ssize_t batadv_socket_write(struct file *file, const char __user *buff,
150 size_t len, loff_t *off)
151 {
152 struct batadv_socket_client *socket_client = file->private_data;
153 struct batadv_priv *bat_priv = socket_client->bat_priv;
154 struct batadv_hard_iface *primary_if = NULL;
155 struct sk_buff *skb;
156 struct batadv_icmp_packet_rr *icmp_packet_rr;
157 struct batadv_icmp_header *icmp_header;
158 struct batadv_orig_node *orig_node = NULL;
159 struct batadv_neigh_node *neigh_node = NULL;
160 size_t packet_len = sizeof(struct batadv_icmp_packet);
161 uint8_t *addr;
162
163 if (len < sizeof(struct batadv_icmp_header)) {
164 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
165 "Error - can't send packet from char device: invalid packet size\n");
166 return -EINVAL;
167 }
168
169 primary_if = batadv_primary_if_get_selected(bat_priv);
170
171 if (!primary_if) {
172 len = -EFAULT;
173 goto out;
174 }
175
176 if (len >= BATADV_ICMP_MAX_PACKET_SIZE)
177 packet_len = BATADV_ICMP_MAX_PACKET_SIZE;
178 else
179 packet_len = len;
180
181 skb = netdev_alloc_skb_ip_align(NULL, packet_len + ETH_HLEN);
182 if (!skb) {
183 len = -ENOMEM;
184 goto out;
185 }
186
187 skb->priority = TC_PRIO_CONTROL;
188 skb_reserve(skb, ETH_HLEN);
189 icmp_header = (struct batadv_icmp_header *)skb_put(skb, packet_len);
190
191 if (copy_from_user(icmp_header, buff, packet_len)) {
192 len = -EFAULT;
193 goto free_skb;
194 }
195
196 if (icmp_header->packet_type != BATADV_ICMP) {
197 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
198 "Error - can't send packet from char device: got bogus packet type (expected: BAT_ICMP)\n");
199 len = -EINVAL;
200 goto free_skb;
201 }
202
203 switch (icmp_header->msg_type) {
204 case BATADV_ECHO_REQUEST:
205 if (len < sizeof(struct batadv_icmp_packet)) {
206 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
207 "Error - can't send packet from char device: invalid packet size\n");
208 len = -EINVAL;
209 goto free_skb;
210 }
211
212 if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE)
213 goto dst_unreach;
214
215 orig_node = batadv_orig_hash_find(bat_priv, icmp_header->dst);
216 if (!orig_node)
217 goto dst_unreach;
218
219 neigh_node = batadv_orig_router_get(orig_node,
220 BATADV_IF_DEFAULT);
221 if (!neigh_node)
222 goto dst_unreach;
223
224 if (!neigh_node->if_incoming)
225 goto dst_unreach;
226
227 if (neigh_node->if_incoming->if_status != BATADV_IF_ACTIVE)
228 goto dst_unreach;
229
230 icmp_packet_rr = (struct batadv_icmp_packet_rr *)icmp_header;
231 if (packet_len == sizeof(*icmp_packet_rr)) {
232 addr = neigh_node->if_incoming->net_dev->dev_addr;
233 ether_addr_copy(icmp_packet_rr->rr[0], addr);
234 }
235
236 break;
237 default:
238 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
239 "Error - can't send packet from char device: got unknown message type\n");
240 len = -EINVAL;
241 goto free_skb;
242 }
243
244 icmp_header->uid = socket_client->index;
245
246 if (icmp_header->version != BATADV_COMPAT_VERSION) {
247 icmp_header->msg_type = BATADV_PARAMETER_PROBLEM;
248 icmp_header->version = BATADV_COMPAT_VERSION;
249 batadv_socket_add_packet(socket_client, icmp_header,
250 packet_len);
251 goto free_skb;
252 }
253
254 ether_addr_copy(icmp_header->orig, primary_if->net_dev->dev_addr);
255
256 batadv_send_skb_packet(skb, neigh_node->if_incoming, neigh_node->addr);
257 goto out;
258
259 dst_unreach:
260 icmp_header->msg_type = BATADV_DESTINATION_UNREACHABLE;
261 batadv_socket_add_packet(socket_client, icmp_header, packet_len);
262 free_skb:
263 kfree_skb(skb);
264 out:
265 if (primary_if)
266 batadv_hardif_free_ref(primary_if);
267 if (neigh_node)
268 batadv_neigh_node_free_ref(neigh_node);
269 if (orig_node)
270 batadv_orig_node_free_ref(orig_node);
271 return len;
272 }
273
batadv_socket_poll(struct file * file,poll_table * wait)274 static unsigned int batadv_socket_poll(struct file *file, poll_table *wait)
275 {
276 struct batadv_socket_client *socket_client = file->private_data;
277
278 poll_wait(file, &socket_client->queue_wait, wait);
279
280 if (socket_client->queue_len > 0)
281 return POLLIN | POLLRDNORM;
282
283 return 0;
284 }
285
286 static const struct file_operations batadv_fops = {
287 .owner = THIS_MODULE,
288 .open = batadv_socket_open,
289 .release = batadv_socket_release,
290 .read = batadv_socket_read,
291 .write = batadv_socket_write,
292 .poll = batadv_socket_poll,
293 .llseek = no_llseek,
294 };
295
batadv_socket_setup(struct batadv_priv * bat_priv)296 int batadv_socket_setup(struct batadv_priv *bat_priv)
297 {
298 struct dentry *d;
299
300 if (!bat_priv->debug_dir)
301 goto err;
302
303 d = debugfs_create_file(BATADV_ICMP_SOCKET, S_IFREG | S_IWUSR | S_IRUSR,
304 bat_priv->debug_dir, bat_priv, &batadv_fops);
305 if (!d)
306 goto err;
307
308 return 0;
309
310 err:
311 return -ENOMEM;
312 }
313
314 /**
315 * batadv_socket_receive_packet - schedule an icmp packet to be sent to userspace
316 * on an icmp socket.
317 * @socket_client: the socket this packet belongs to
318 * @icmph: pointer to the header of the icmp packet
319 * @icmp_len: total length of the icmp packet
320 */
batadv_socket_add_packet(struct batadv_socket_client * socket_client,struct batadv_icmp_header * icmph,size_t icmp_len)321 static void batadv_socket_add_packet(struct batadv_socket_client *socket_client,
322 struct batadv_icmp_header *icmph,
323 size_t icmp_len)
324 {
325 struct batadv_socket_packet *socket_packet;
326 size_t len;
327
328 socket_packet = kmalloc(sizeof(*socket_packet), GFP_ATOMIC);
329
330 if (!socket_packet)
331 return;
332
333 len = icmp_len;
334 /* check the maximum length before filling the buffer */
335 if (len > sizeof(socket_packet->icmp_packet))
336 len = sizeof(socket_packet->icmp_packet);
337
338 INIT_LIST_HEAD(&socket_packet->list);
339 memcpy(&socket_packet->icmp_packet, icmph, len);
340 socket_packet->icmp_len = len;
341
342 spin_lock_bh(&socket_client->lock);
343
344 /* while waiting for the lock the socket_client could have been
345 * deleted
346 */
347 if (!batadv_socket_client_hash[icmph->uid]) {
348 spin_unlock_bh(&socket_client->lock);
349 kfree(socket_packet);
350 return;
351 }
352
353 list_add_tail(&socket_packet->list, &socket_client->queue_list);
354 socket_client->queue_len++;
355
356 if (socket_client->queue_len > 100) {
357 socket_packet = list_first_entry(&socket_client->queue_list,
358 struct batadv_socket_packet,
359 list);
360
361 list_del(&socket_packet->list);
362 kfree(socket_packet);
363 socket_client->queue_len--;
364 }
365
366 spin_unlock_bh(&socket_client->lock);
367
368 wake_up(&socket_client->queue_wait);
369 }
370
371 /**
372 * batadv_socket_receive_packet - schedule an icmp packet to be received
373 * locally and sent to userspace.
374 * @icmph: pointer to the header of the icmp packet
375 * @icmp_len: total length of the icmp packet
376 */
batadv_socket_receive_packet(struct batadv_icmp_header * icmph,size_t icmp_len)377 void batadv_socket_receive_packet(struct batadv_icmp_header *icmph,
378 size_t icmp_len)
379 {
380 struct batadv_socket_client *hash;
381
382 hash = batadv_socket_client_hash[icmph->uid];
383 if (hash)
384 batadv_socket_add_packet(hash, icmph, icmp_len);
385 }
386