Merge branch 'batman-adv/next' of git://git.open-mesh.org/ecsv/linux-merge
[linux-3.10.git] / net / batman-adv / icmp_socket.c
1 /*
2  * Copyright (C) 2007-2011 B.A.T.M.A.N. contributors:
3  *
4  * Marek Lindner
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 <linux/debugfs.h>
24 #include <linux/slab.h>
25 #include "icmp_socket.h"
26 #include "send.h"
27 #include "hash.h"
28 #include "originator.h"
29 #include "hard-interface.h"
30
31 static struct socket_client *socket_client_hash[256];
32
33 static void bat_socket_add_packet(struct socket_client *socket_client,
34                                   struct icmp_packet_rr *icmp_packet,
35                                   size_t icmp_len);
36
37 void bat_socket_init(void)
38 {
39         memset(socket_client_hash, 0, sizeof(socket_client_hash));
40 }
41
42 static int bat_socket_open(struct inode *inode, struct file *file)
43 {
44         unsigned int i;
45         struct socket_client *socket_client;
46
47         nonseekable_open(inode, file);
48
49         socket_client = kmalloc(sizeof(struct socket_client), GFP_KERNEL);
50
51         if (!socket_client)
52                 return -ENOMEM;
53
54         for (i = 0; i < ARRAY_SIZE(socket_client_hash); i++) {
55                 if (!socket_client_hash[i]) {
56                         socket_client_hash[i] = socket_client;
57                         break;
58                 }
59         }
60
61         if (i == ARRAY_SIZE(socket_client_hash)) {
62                 pr_err("Error - can't add another packet client: "
63                        "maximum number of clients reached\n");
64                 kfree(socket_client);
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         inc_module_count();
78         return 0;
79 }
80
81 static int bat_socket_release(struct inode *inode, struct file *file)
82 {
83         struct socket_client *socket_client = file->private_data;
84         struct socket_packet *socket_packet;
85         struct list_head *list_pos, *list_pos_tmp;
86
87         spin_lock_bh(&socket_client->lock);
88
89         /* for all packets in the queue ... */
90         list_for_each_safe(list_pos, list_pos_tmp, &socket_client->queue_list) {
91                 socket_packet = list_entry(list_pos,
92                                            struct socket_packet, list);
93
94                 list_del(list_pos);
95                 kfree(socket_packet);
96         }
97
98         socket_client_hash[socket_client->index] = NULL;
99         spin_unlock_bh(&socket_client->lock);
100
101         kfree(socket_client);
102         dec_module_count();
103
104         return 0;
105 }
106
107 static ssize_t bat_socket_read(struct file *file, char __user *buf,
108                                size_t count, loff_t *ppos)
109 {
110         struct socket_client *socket_client = file->private_data;
111         struct socket_packet *socket_packet;
112         size_t packet_len;
113         int error;
114
115         if ((file->f_flags & O_NONBLOCK) && (socket_client->queue_len == 0))
116                 return -EAGAIN;
117
118         if ((!buf) || (count < sizeof(struct icmp_packet)))
119                 return -EINVAL;
120
121         if (!access_ok(VERIFY_WRITE, buf, count))
122                 return -EFAULT;
123
124         error = wait_event_interruptible(socket_client->queue_wait,
125                                          socket_client->queue_len);
126
127         if (error)
128                 return error;
129
130         spin_lock_bh(&socket_client->lock);
131
132         socket_packet = list_first_entry(&socket_client->queue_list,
133                                          struct socket_packet, list);
134         list_del(&socket_packet->list);
135         socket_client->queue_len--;
136
137         spin_unlock_bh(&socket_client->lock);
138
139         error = __copy_to_user(buf, &socket_packet->icmp_packet,
140                                socket_packet->icmp_len);
141
142         packet_len = socket_packet->icmp_len;
143         kfree(socket_packet);
144
145         if (error)
146                 return -EFAULT;
147
148         return packet_len;
149 }
150
151 static ssize_t bat_socket_write(struct file *file, const char __user *buff,
152                                 size_t len, loff_t *off)
153 {
154         struct socket_client *socket_client = file->private_data;
155         struct bat_priv *bat_priv = socket_client->bat_priv;
156         struct sk_buff *skb;
157         struct icmp_packet_rr *icmp_packet;
158
159         struct orig_node *orig_node = NULL;
160         struct neigh_node *neigh_node = NULL;
161         size_t packet_len = sizeof(struct icmp_packet);
162
163         if (len < sizeof(struct icmp_packet)) {
164                 bat_dbg(DBG_BATMAN, bat_priv,
165                         "Error - can't send packet from char device: "
166                         "invalid packet size\n");
167                 return -EINVAL;
168         }
169
170         if (!bat_priv->primary_if)
171                 return -EFAULT;
172
173         if (len >= sizeof(struct icmp_packet_rr))
174                 packet_len = sizeof(struct icmp_packet_rr);
175
176         skb = dev_alloc_skb(packet_len + sizeof(struct ethhdr));
177         if (!skb)
178                 return -ENOMEM;
179
180         skb_reserve(skb, sizeof(struct ethhdr));
181         icmp_packet = (struct icmp_packet_rr *)skb_put(skb, packet_len);
182
183         if (!access_ok(VERIFY_READ, buff, packet_len)) {
184                 len = -EFAULT;
185                 goto free_skb;
186         }
187
188         if (__copy_from_user(icmp_packet, buff, packet_len)) {
189                 len = -EFAULT;
190                 goto free_skb;
191         }
192
193         if (icmp_packet->packet_type != BAT_ICMP) {
194                 bat_dbg(DBG_BATMAN, bat_priv,
195                         "Error - can't send packet from char device: "
196                         "got bogus packet type (expected: BAT_ICMP)\n");
197                 len = -EINVAL;
198                 goto free_skb;
199         }
200
201         if (icmp_packet->msg_type != ECHO_REQUEST) {
202                 bat_dbg(DBG_BATMAN, bat_priv,
203                         "Error - can't send packet from char device: "
204                         "got bogus message type (expected: ECHO_REQUEST)\n");
205                 len = -EINVAL;
206                 goto free_skb;
207         }
208
209         icmp_packet->uid = socket_client->index;
210
211         if (icmp_packet->version != COMPAT_VERSION) {
212                 icmp_packet->msg_type = PARAMETER_PROBLEM;
213                 icmp_packet->ttl = COMPAT_VERSION;
214                 bat_socket_add_packet(socket_client, icmp_packet, packet_len);
215                 goto free_skb;
216         }
217
218         if (atomic_read(&bat_priv->mesh_state) != MESH_ACTIVE)
219                 goto dst_unreach;
220
221         rcu_read_lock();
222         orig_node = orig_hash_find(bat_priv, icmp_packet->dst);
223
224         if (!orig_node)
225                 goto unlock;
226
227         neigh_node = orig_node->router;
228
229         if (!neigh_node)
230                 goto unlock;
231
232         if (!atomic_inc_not_zero(&neigh_node->refcount)) {
233                 neigh_node = NULL;
234                 goto unlock;
235         }
236
237         rcu_read_unlock();
238
239         if (!neigh_node->if_incoming)
240                 goto dst_unreach;
241
242         if (neigh_node->if_incoming->if_status != IF_ACTIVE)
243                 goto dst_unreach;
244
245         memcpy(icmp_packet->orig,
246                bat_priv->primary_if->net_dev->dev_addr, ETH_ALEN);
247
248         if (packet_len == sizeof(struct icmp_packet_rr))
249                 memcpy(icmp_packet->rr,
250                        neigh_node->if_incoming->net_dev->dev_addr, ETH_ALEN);
251
252         send_skb_packet(skb, neigh_node->if_incoming, neigh_node->addr);
253         goto out;
254
255 unlock:
256         rcu_read_unlock();
257 dst_unreach:
258         icmp_packet->msg_type = DESTINATION_UNREACHABLE;
259         bat_socket_add_packet(socket_client, icmp_packet, packet_len);
260 free_skb:
261         kfree_skb(skb);
262 out:
263         if (neigh_node)
264                 neigh_node_free_ref(neigh_node);
265         if (orig_node)
266                 orig_node_free_ref(orig_node);
267         return len;
268 }
269
270 static unsigned int bat_socket_poll(struct file *file, poll_table *wait)
271 {
272         struct socket_client *socket_client = file->private_data;
273
274         poll_wait(file, &socket_client->queue_wait, wait);
275
276         if (socket_client->queue_len > 0)
277                 return POLLIN | POLLRDNORM;
278
279         return 0;
280 }
281
282 static const struct file_operations fops = {
283         .owner = THIS_MODULE,
284         .open = bat_socket_open,
285         .release = bat_socket_release,
286         .read = bat_socket_read,
287         .write = bat_socket_write,
288         .poll = bat_socket_poll,
289         .llseek = no_llseek,
290 };
291
292 int bat_socket_setup(struct bat_priv *bat_priv)
293 {
294         struct dentry *d;
295
296         if (!bat_priv->debug_dir)
297                 goto err;
298
299         d = debugfs_create_file(ICMP_SOCKET, S_IFREG | S_IWUSR | S_IRUSR,
300                                 bat_priv->debug_dir, bat_priv, &fops);
301         if (d)
302                 goto err;
303
304         return 0;
305
306 err:
307         return 1;
308 }
309
310 static void bat_socket_add_packet(struct socket_client *socket_client,
311                                   struct icmp_packet_rr *icmp_packet,
312                                   size_t icmp_len)
313 {
314         struct socket_packet *socket_packet;
315
316         socket_packet = kmalloc(sizeof(struct socket_packet), GFP_ATOMIC);
317
318         if (!socket_packet)
319                 return;
320
321         INIT_LIST_HEAD(&socket_packet->list);
322         memcpy(&socket_packet->icmp_packet, icmp_packet, icmp_len);
323         socket_packet->icmp_len = icmp_len;
324
325         spin_lock_bh(&socket_client->lock);
326
327         /* while waiting for the lock the socket_client could have been
328          * deleted */
329         if (!socket_client_hash[icmp_packet->uid]) {
330                 spin_unlock_bh(&socket_client->lock);
331                 kfree(socket_packet);
332                 return;
333         }
334
335         list_add_tail(&socket_packet->list, &socket_client->queue_list);
336         socket_client->queue_len++;
337
338         if (socket_client->queue_len > 100) {
339                 socket_packet = list_first_entry(&socket_client->queue_list,
340                                                  struct socket_packet, list);
341
342                 list_del(&socket_packet->list);
343                 kfree(socket_packet);
344                 socket_client->queue_len--;
345         }
346
347         spin_unlock_bh(&socket_client->lock);
348
349         wake_up(&socket_client->queue_wait);
350 }
351
352 void bat_socket_receive_packet(struct icmp_packet_rr *icmp_packet,
353                                size_t icmp_len)
354 {
355         struct socket_client *hash = socket_client_hash[icmp_packet->uid];
356
357         if (hash)
358                 bat_socket_add_packet(hash, icmp_packet, icmp_len);
359 }