1 /* Copyright (C) 2007-2015 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 "icmp_socket.h"
19 #include "main.h"
20
21 #include <linux/atomic.h>
22 #include <linux/compiler.h>
23 #include <linux/debugfs.h>
24 #include <linux/errno.h>
25 #include <linux/etherdevice.h>
26 #include <linux/export.h>
27 #include <linux/fcntl.h>
28 #include <linux/fs.h>
29 #include <linux/if_ether.h>
30 #include <linux/kernel.h>
31 #include <linux/list.h>
32 #include <linux/module.h>
33 #include <linux/netdevice.h>
34 #include <linux/pkt_sched.h>
35 #include <linux/poll.h>
36 #include <linux/printk.h>
37 #include <linux/sched.h> /* for linux/wait.h */
38 #include <linux/skbuff.h>
39 #include <linux/slab.h>
40 #include <linux/spinlock.h>
41 #include <linux/stat.h>
42 #include <linux/stddef.h>
43 #include <linux/string.h>
44 #include <linux/uaccess.h>
45 #include <linux/wait.h>
46
47 #include "hard-interface.h"
48 #include "originator.h"
49 #include "packet.h"
50 #include "send.h"
51
52 static struct batadv_socket_client *batadv_socket_client_hash[256];
53
54 static void batadv_socket_add_packet(struct batadv_socket_client *socket_client,
55 struct batadv_icmp_header *icmph,
56 size_t icmp_len);
57
batadv_socket_init(void)58 void batadv_socket_init(void)
59 {
60 memset(batadv_socket_client_hash, 0, sizeof(batadv_socket_client_hash));
61 }
62
batadv_socket_open(struct inode * inode,struct file * file)63 static int batadv_socket_open(struct inode *inode, struct file *file)
64 {
65 unsigned int i;
66 struct batadv_socket_client *socket_client;
67
68 if (!try_module_get(THIS_MODULE))
69 return -EBUSY;
70
71 nonseekable_open(inode, file);
72
73 socket_client = kmalloc(sizeof(*socket_client), GFP_KERNEL);
74 if (!socket_client) {
75 module_put(THIS_MODULE);
76 return -ENOMEM;
77 }
78
79 for (i = 0; i < ARRAY_SIZE(batadv_socket_client_hash); i++) {
80 if (!batadv_socket_client_hash[i]) {
81 batadv_socket_client_hash[i] = socket_client;
82 break;
83 }
84 }
85
86 if (i == ARRAY_SIZE(batadv_socket_client_hash)) {
87 pr_err("Error - can't add another packet client: maximum number of clients reached\n");
88 kfree(socket_client);
89 module_put(THIS_MODULE);
90 return -EXFULL;
91 }
92
93 INIT_LIST_HEAD(&socket_client->queue_list);
94 socket_client->queue_len = 0;
95 socket_client->index = i;
96 socket_client->bat_priv = inode->i_private;
97 spin_lock_init(&socket_client->lock);
98 init_waitqueue_head(&socket_client->queue_wait);
99
100 file->private_data = socket_client;
101
102 return 0;
103 }
104
batadv_socket_release(struct inode * inode,struct file * file)105 static int batadv_socket_release(struct inode *inode, struct file *file)
106 {
107 struct batadv_socket_client *socket_client = file->private_data;
108 struct batadv_socket_packet *socket_packet;
109 struct list_head *list_pos, *list_pos_tmp;
110
111 spin_lock_bh(&socket_client->lock);
112
113 /* for all packets in the queue ... */
114 list_for_each_safe(list_pos, list_pos_tmp, &socket_client->queue_list) {
115 socket_packet = list_entry(list_pos,
116 struct batadv_socket_packet, list);
117
118 list_del(list_pos);
119 kfree(socket_packet);
120 }
121
122 batadv_socket_client_hash[socket_client->index] = NULL;
123 spin_unlock_bh(&socket_client->lock);
124
125 kfree(socket_client);
126 module_put(THIS_MODULE);
127
128 return 0;
129 }
130
batadv_socket_read(struct file * file,char __user * buf,size_t count,loff_t * ppos)131 static ssize_t batadv_socket_read(struct file *file, char __user *buf,
132 size_t count, loff_t *ppos)
133 {
134 struct batadv_socket_client *socket_client = file->private_data;
135 struct batadv_socket_packet *socket_packet;
136 size_t packet_len;
137 int error;
138
139 if ((file->f_flags & O_NONBLOCK) && (socket_client->queue_len == 0))
140 return -EAGAIN;
141
142 if ((!buf) || (count < sizeof(struct batadv_icmp_packet)))
143 return -EINVAL;
144
145 if (!access_ok(VERIFY_WRITE, buf, count))
146 return -EFAULT;
147
148 error = wait_event_interruptible(socket_client->queue_wait,
149 socket_client->queue_len);
150
151 if (error)
152 return error;
153
154 spin_lock_bh(&socket_client->lock);
155
156 socket_packet = list_first_entry(&socket_client->queue_list,
157 struct batadv_socket_packet, list);
158 list_del(&socket_packet->list);
159 socket_client->queue_len--;
160
161 spin_unlock_bh(&socket_client->lock);
162
163 packet_len = min(count, socket_packet->icmp_len);
164 error = copy_to_user(buf, &socket_packet->icmp_packet, packet_len);
165
166 kfree(socket_packet);
167
168 if (error)
169 return -EFAULT;
170
171 return packet_len;
172 }
173
batadv_socket_write(struct file * file,const char __user * buff,size_t len,loff_t * off)174 static ssize_t batadv_socket_write(struct file *file, const char __user *buff,
175 size_t len, loff_t *off)
176 {
177 struct batadv_socket_client *socket_client = file->private_data;
178 struct batadv_priv *bat_priv = socket_client->bat_priv;
179 struct batadv_hard_iface *primary_if = NULL;
180 struct sk_buff *skb;
181 struct batadv_icmp_packet_rr *icmp_packet_rr;
182 struct batadv_icmp_header *icmp_header;
183 struct batadv_orig_node *orig_node = NULL;
184 struct batadv_neigh_node *neigh_node = NULL;
185 size_t packet_len = sizeof(struct batadv_icmp_packet);
186 u8 *addr;
187
188 if (len < sizeof(struct batadv_icmp_header)) {
189 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
190 "Error - can't send packet from char device: invalid packet size\n");
191 return -EINVAL;
192 }
193
194 primary_if = batadv_primary_if_get_selected(bat_priv);
195
196 if (!primary_if) {
197 len = -EFAULT;
198 goto out;
199 }
200
201 if (len >= BATADV_ICMP_MAX_PACKET_SIZE)
202 packet_len = BATADV_ICMP_MAX_PACKET_SIZE;
203 else
204 packet_len = len;
205
206 skb = netdev_alloc_skb_ip_align(NULL, packet_len + ETH_HLEN);
207 if (!skb) {
208 len = -ENOMEM;
209 goto out;
210 }
211
212 skb->priority = TC_PRIO_CONTROL;
213 skb_reserve(skb, ETH_HLEN);
214 icmp_header = (struct batadv_icmp_header *)skb_put(skb, packet_len);
215
216 if (copy_from_user(icmp_header, buff, packet_len)) {
217 len = -EFAULT;
218 goto free_skb;
219 }
220
221 if (icmp_header->packet_type != BATADV_ICMP) {
222 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
223 "Error - can't send packet from char device: got bogus packet type (expected: BAT_ICMP)\n");
224 len = -EINVAL;
225 goto free_skb;
226 }
227
228 switch (icmp_header->msg_type) {
229 case BATADV_ECHO_REQUEST:
230 if (len < sizeof(struct batadv_icmp_packet)) {
231 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
232 "Error - can't send packet from char device: invalid packet size\n");
233 len = -EINVAL;
234 goto free_skb;
235 }
236
237 if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE)
238 goto dst_unreach;
239
240 orig_node = batadv_orig_hash_find(bat_priv, icmp_header->dst);
241 if (!orig_node)
242 goto dst_unreach;
243
244 neigh_node = batadv_orig_router_get(orig_node,
245 BATADV_IF_DEFAULT);
246 if (!neigh_node)
247 goto dst_unreach;
248
249 if (!neigh_node->if_incoming)
250 goto dst_unreach;
251
252 if (neigh_node->if_incoming->if_status != BATADV_IF_ACTIVE)
253 goto dst_unreach;
254
255 icmp_packet_rr = (struct batadv_icmp_packet_rr *)icmp_header;
256 if (packet_len == sizeof(*icmp_packet_rr)) {
257 addr = neigh_node->if_incoming->net_dev->dev_addr;
258 ether_addr_copy(icmp_packet_rr->rr[0], addr);
259 }
260
261 break;
262 default:
263 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
264 "Error - can't send packet from char device: got unknown message type\n");
265 len = -EINVAL;
266 goto free_skb;
267 }
268
269 icmp_header->uid = socket_client->index;
270
271 if (icmp_header->version != BATADV_COMPAT_VERSION) {
272 icmp_header->msg_type = BATADV_PARAMETER_PROBLEM;
273 icmp_header->version = BATADV_COMPAT_VERSION;
274 batadv_socket_add_packet(socket_client, icmp_header,
275 packet_len);
276 goto free_skb;
277 }
278
279 ether_addr_copy(icmp_header->orig, primary_if->net_dev->dev_addr);
280
281 batadv_send_skb_packet(skb, neigh_node->if_incoming, neigh_node->addr);
282 goto out;
283
284 dst_unreach:
285 icmp_header->msg_type = BATADV_DESTINATION_UNREACHABLE;
286 batadv_socket_add_packet(socket_client, icmp_header, packet_len);
287 free_skb:
288 kfree_skb(skb);
289 out:
290 if (primary_if)
291 batadv_hardif_free_ref(primary_if);
292 if (neigh_node)
293 batadv_neigh_node_free_ref(neigh_node);
294 if (orig_node)
295 batadv_orig_node_free_ref(orig_node);
296 return len;
297 }
298
batadv_socket_poll(struct file * file,poll_table * wait)299 static unsigned int batadv_socket_poll(struct file *file, poll_table *wait)
300 {
301 struct batadv_socket_client *socket_client = file->private_data;
302
303 poll_wait(file, &socket_client->queue_wait, wait);
304
305 if (socket_client->queue_len > 0)
306 return POLLIN | POLLRDNORM;
307
308 return 0;
309 }
310
311 static const struct file_operations batadv_fops = {
312 .owner = THIS_MODULE,
313 .open = batadv_socket_open,
314 .release = batadv_socket_release,
315 .read = batadv_socket_read,
316 .write = batadv_socket_write,
317 .poll = batadv_socket_poll,
318 .llseek = no_llseek,
319 };
320
batadv_socket_setup(struct batadv_priv * bat_priv)321 int batadv_socket_setup(struct batadv_priv *bat_priv)
322 {
323 struct dentry *d;
324
325 if (!bat_priv->debug_dir)
326 goto err;
327
328 d = debugfs_create_file(BATADV_ICMP_SOCKET, S_IFREG | S_IWUSR | S_IRUSR,
329 bat_priv->debug_dir, bat_priv, &batadv_fops);
330 if (!d)
331 goto err;
332
333 return 0;
334
335 err:
336 return -ENOMEM;
337 }
338
339 /**
340 * batadv_socket_receive_packet - schedule an icmp packet to be sent to
341 * userspace on an icmp socket.
342 * @socket_client: the socket this packet belongs to
343 * @icmph: pointer to the header of the icmp packet
344 * @icmp_len: total length of the icmp packet
345 */
batadv_socket_add_packet(struct batadv_socket_client * socket_client,struct batadv_icmp_header * icmph,size_t icmp_len)346 static void batadv_socket_add_packet(struct batadv_socket_client *socket_client,
347 struct batadv_icmp_header *icmph,
348 size_t icmp_len)
349 {
350 struct batadv_socket_packet *socket_packet;
351 size_t len;
352
353 socket_packet = kmalloc(sizeof(*socket_packet), GFP_ATOMIC);
354
355 if (!socket_packet)
356 return;
357
358 len = icmp_len;
359 /* check the maximum length before filling the buffer */
360 if (len > sizeof(socket_packet->icmp_packet))
361 len = sizeof(socket_packet->icmp_packet);
362
363 INIT_LIST_HEAD(&socket_packet->list);
364 memcpy(&socket_packet->icmp_packet, icmph, len);
365 socket_packet->icmp_len = len;
366
367 spin_lock_bh(&socket_client->lock);
368
369 /* while waiting for the lock the socket_client could have been
370 * deleted
371 */
372 if (!batadv_socket_client_hash[icmph->uid]) {
373 spin_unlock_bh(&socket_client->lock);
374 kfree(socket_packet);
375 return;
376 }
377
378 list_add_tail(&socket_packet->list, &socket_client->queue_list);
379 socket_client->queue_len++;
380
381 if (socket_client->queue_len > 100) {
382 socket_packet = list_first_entry(&socket_client->queue_list,
383 struct batadv_socket_packet,
384 list);
385
386 list_del(&socket_packet->list);
387 kfree(socket_packet);
388 socket_client->queue_len--;
389 }
390
391 spin_unlock_bh(&socket_client->lock);
392
393 wake_up(&socket_client->queue_wait);
394 }
395
396 /**
397 * batadv_socket_receive_packet - schedule an icmp packet to be received
398 * locally and sent to userspace.
399 * @icmph: pointer to the header of the icmp packet
400 * @icmp_len: total length of the icmp packet
401 */
batadv_socket_receive_packet(struct batadv_icmp_header * icmph,size_t icmp_len)402 void batadv_socket_receive_packet(struct batadv_icmp_header *icmph,
403 size_t icmp_len)
404 {
405 struct batadv_socket_client *hash;
406
407 hash = batadv_socket_client_hash[icmph->uid];
408 if (hash)
409 batadv_socket_add_packet(hash, icmph, icmp_len);
410 }
411