drm/amdgpu/vg20:Restruct uvd to support multiple uvds
[muen/linux.git] / net / batman-adv / icmp_socket.c
1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (C) 2007-2018  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, see <http://www.gnu.org/licenses/>.
17  */
18
19 #include "icmp_socket.h"
20 #include "main.h"
21
22 #include <linux/atomic.h>
23 #include <linux/compiler.h>
24 #include <linux/debugfs.h>
25 #include <linux/errno.h>
26 #include <linux/etherdevice.h>
27 #include <linux/eventpoll.h>
28 #include <linux/export.h>
29 #include <linux/fcntl.h>
30 #include <linux/fs.h>
31 #include <linux/gfp.h>
32 #include <linux/if_ether.h>
33 #include <linux/kernel.h>
34 #include <linux/list.h>
35 #include <linux/module.h>
36 #include <linux/netdevice.h>
37 #include <linux/pkt_sched.h>
38 #include <linux/poll.h>
39 #include <linux/printk.h>
40 #include <linux/sched.h> /* for linux/wait.h */
41 #include <linux/skbuff.h>
42 #include <linux/slab.h>
43 #include <linux/spinlock.h>
44 #include <linux/stddef.h>
45 #include <linux/string.h>
46 #include <linux/uaccess.h>
47 #include <linux/wait.h>
48 #include <uapi/linux/batadv_packet.h>
49
50 #include "hard-interface.h"
51 #include "log.h"
52 #include "originator.h"
53 #include "send.h"
54
55 static struct batadv_socket_client *batadv_socket_client_hash[256];
56
57 static void batadv_socket_add_packet(struct batadv_socket_client *socket_client,
58                                      struct batadv_icmp_header *icmph,
59                                      size_t icmp_len);
60
61 /**
62  * batadv_socket_init() - Initialize soft interface independent socket data
63  */
64 void batadv_socket_init(void)
65 {
66         memset(batadv_socket_client_hash, 0, sizeof(batadv_socket_client_hash));
67 }
68
69 static int batadv_socket_open(struct inode *inode, struct file *file)
70 {
71         unsigned int i;
72         struct batadv_socket_client *socket_client;
73
74         if (!try_module_get(THIS_MODULE))
75                 return -EBUSY;
76
77         nonseekable_open(inode, file);
78
79         socket_client = kmalloc(sizeof(*socket_client), GFP_KERNEL);
80         if (!socket_client) {
81                 module_put(THIS_MODULE);
82                 return -ENOMEM;
83         }
84
85         for (i = 0; i < ARRAY_SIZE(batadv_socket_client_hash); i++) {
86                 if (!batadv_socket_client_hash[i]) {
87                         batadv_socket_client_hash[i] = socket_client;
88                         break;
89                 }
90         }
91
92         if (i == ARRAY_SIZE(batadv_socket_client_hash)) {
93                 pr_err("Error - can't add another packet client: maximum number of clients reached\n");
94                 kfree(socket_client);
95                 module_put(THIS_MODULE);
96                 return -EXFULL;
97         }
98
99         INIT_LIST_HEAD(&socket_client->queue_list);
100         socket_client->queue_len = 0;
101         socket_client->index = i;
102         socket_client->bat_priv = inode->i_private;
103         spin_lock_init(&socket_client->lock);
104         init_waitqueue_head(&socket_client->queue_wait);
105
106         file->private_data = socket_client;
107
108         return 0;
109 }
110
111 static int batadv_socket_release(struct inode *inode, struct file *file)
112 {
113         struct batadv_socket_client *client = file->private_data;
114         struct batadv_socket_packet *packet, *tmp;
115
116         spin_lock_bh(&client->lock);
117
118         /* for all packets in the queue ... */
119         list_for_each_entry_safe(packet, tmp, &client->queue_list, list) {
120                 list_del(&packet->list);
121                 kfree(packet);
122         }
123
124         batadv_socket_client_hash[client->index] = NULL;
125         spin_unlock_bh(&client->lock);
126
127         kfree(client);
128         module_put(THIS_MODULE);
129
130         return 0;
131 }
132
133 static ssize_t batadv_socket_read(struct file *file, char __user *buf,
134                                   size_t count, loff_t *ppos)
135 {
136         struct batadv_socket_client *socket_client = file->private_data;
137         struct batadv_socket_packet *socket_packet;
138         size_t packet_len;
139         int error;
140
141         if ((file->f_flags & O_NONBLOCK) && socket_client->queue_len == 0)
142                 return -EAGAIN;
143
144         if (!buf || count < sizeof(struct batadv_icmp_packet))
145                 return -EINVAL;
146
147         if (!access_ok(VERIFY_WRITE, buf, count))
148                 return -EFAULT;
149
150         error = wait_event_interruptible(socket_client->queue_wait,
151                                          socket_client->queue_len);
152
153         if (error)
154                 return error;
155
156         spin_lock_bh(&socket_client->lock);
157
158         socket_packet = list_first_entry(&socket_client->queue_list,
159                                          struct batadv_socket_packet, list);
160         list_del(&socket_packet->list);
161         socket_client->queue_len--;
162
163         spin_unlock_bh(&socket_client->lock);
164
165         packet_len = min(count, socket_packet->icmp_len);
166         error = copy_to_user(buf, &socket_packet->icmp_packet, packet_len);
167
168         kfree(socket_packet);
169
170         if (error)
171                 return -EFAULT;
172
173         return packet_len;
174 }
175
176 static ssize_t batadv_socket_write(struct file *file, const char __user *buff,
177                                    size_t len, loff_t *off)
178 {
179         struct batadv_socket_client *socket_client = file->private_data;
180         struct batadv_priv *bat_priv = socket_client->bat_priv;
181         struct batadv_hard_iface *primary_if = NULL;
182         struct sk_buff *skb;
183         struct batadv_icmp_packet_rr *icmp_packet_rr;
184         struct batadv_icmp_header *icmp_header;
185         struct batadv_orig_node *orig_node = NULL;
186         struct batadv_neigh_node *neigh_node = NULL;
187         size_t packet_len = sizeof(struct batadv_icmp_packet);
188         u8 *addr;
189
190         if (len < sizeof(struct batadv_icmp_header)) {
191                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
192                            "Error - can't send packet from char device: invalid packet size\n");
193                 return -EINVAL;
194         }
195
196         primary_if = batadv_primary_if_get_selected(bat_priv);
197
198         if (!primary_if) {
199                 len = -EFAULT;
200                 goto out;
201         }
202
203         if (len >= BATADV_ICMP_MAX_PACKET_SIZE)
204                 packet_len = BATADV_ICMP_MAX_PACKET_SIZE;
205         else
206                 packet_len = len;
207
208         skb = netdev_alloc_skb_ip_align(NULL, packet_len + ETH_HLEN);
209         if (!skb) {
210                 len = -ENOMEM;
211                 goto out;
212         }
213
214         skb->priority = TC_PRIO_CONTROL;
215         skb_reserve(skb, ETH_HLEN);
216         icmp_header = skb_put(skb, packet_len);
217
218         if (copy_from_user(icmp_header, buff, packet_len)) {
219                 len = -EFAULT;
220                 goto free_skb;
221         }
222
223         if (icmp_header->packet_type != BATADV_ICMP) {
224                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
225                            "Error - can't send packet from char device: got bogus packet type (expected: BAT_ICMP)\n");
226                 len = -EINVAL;
227                 goto free_skb;
228         }
229
230         switch (icmp_header->msg_type) {
231         case BATADV_ECHO_REQUEST:
232                 if (len < sizeof(struct batadv_icmp_packet)) {
233                         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
234                                    "Error - can't send packet from char device: invalid packet size\n");
235                         len = -EINVAL;
236                         goto free_skb;
237                 }
238
239                 if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE)
240                         goto dst_unreach;
241
242                 orig_node = batadv_orig_hash_find(bat_priv, icmp_header->dst);
243                 if (!orig_node)
244                         goto dst_unreach;
245
246                 neigh_node = batadv_orig_router_get(orig_node,
247                                                     BATADV_IF_DEFAULT);
248                 if (!neigh_node)
249                         goto dst_unreach;
250
251                 if (!neigh_node->if_incoming)
252                         goto dst_unreach;
253
254                 if (neigh_node->if_incoming->if_status != BATADV_IF_ACTIVE)
255                         goto dst_unreach;
256
257                 icmp_packet_rr = (struct batadv_icmp_packet_rr *)icmp_header;
258                 if (packet_len == sizeof(*icmp_packet_rr)) {
259                         addr = neigh_node->if_incoming->net_dev->dev_addr;
260                         ether_addr_copy(icmp_packet_rr->rr[0], addr);
261                 }
262
263                 break;
264         default:
265                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
266                            "Error - can't send packet from char device: got unknown message type\n");
267                 len = -EINVAL;
268                 goto free_skb;
269         }
270
271         icmp_header->uid = socket_client->index;
272
273         if (icmp_header->version != BATADV_COMPAT_VERSION) {
274                 icmp_header->msg_type = BATADV_PARAMETER_PROBLEM;
275                 icmp_header->version = BATADV_COMPAT_VERSION;
276                 batadv_socket_add_packet(socket_client, icmp_header,
277                                          packet_len);
278                 goto free_skb;
279         }
280
281         ether_addr_copy(icmp_header->orig, primary_if->net_dev->dev_addr);
282
283         batadv_send_unicast_skb(skb, neigh_node);
284         goto out;
285
286 dst_unreach:
287         icmp_header->msg_type = BATADV_DESTINATION_UNREACHABLE;
288         batadv_socket_add_packet(socket_client, icmp_header, packet_len);
289 free_skb:
290         kfree_skb(skb);
291 out:
292         if (primary_if)
293                 batadv_hardif_put(primary_if);
294         if (neigh_node)
295                 batadv_neigh_node_put(neigh_node);
296         if (orig_node)
297                 batadv_orig_node_put(orig_node);
298         return len;
299 }
300
301 static __poll_t batadv_socket_poll(struct file *file, poll_table *wait)
302 {
303         struct batadv_socket_client *socket_client = file->private_data;
304
305         poll_wait(file, &socket_client->queue_wait, wait);
306
307         if (socket_client->queue_len > 0)
308                 return EPOLLIN | EPOLLRDNORM;
309
310         return 0;
311 }
312
313 static const struct file_operations batadv_fops = {
314         .owner = THIS_MODULE,
315         .open = batadv_socket_open,
316         .release = batadv_socket_release,
317         .read = batadv_socket_read,
318         .write = batadv_socket_write,
319         .poll = batadv_socket_poll,
320         .llseek = no_llseek,
321 };
322
323 /**
324  * batadv_socket_setup() - Create debugfs "socket" file
325  * @bat_priv: the bat priv with all the soft interface information
326  *
327  * Return: 0 on success or negative error number in case of failure
328  */
329 int batadv_socket_setup(struct batadv_priv *bat_priv)
330 {
331         struct dentry *d;
332
333         if (!bat_priv->debug_dir)
334                 goto err;
335
336         d = debugfs_create_file(BATADV_ICMP_SOCKET, 0600, bat_priv->debug_dir,
337                                 bat_priv, &batadv_fops);
338         if (!d)
339                 goto err;
340
341         return 0;
342
343 err:
344         return -ENOMEM;
345 }
346
347 /**
348  * batadv_socket_add_packet() - schedule an icmp packet to be sent to
349  *  userspace on an icmp socket.
350  * @socket_client: the socket this packet belongs to
351  * @icmph: pointer to the header of the icmp packet
352  * @icmp_len: total length of the icmp packet
353  */
354 static void batadv_socket_add_packet(struct batadv_socket_client *socket_client,
355                                      struct batadv_icmp_header *icmph,
356                                      size_t icmp_len)
357 {
358         struct batadv_socket_packet *socket_packet;
359         size_t len;
360
361         socket_packet = kmalloc(sizeof(*socket_packet), GFP_ATOMIC);
362
363         if (!socket_packet)
364                 return;
365
366         len = icmp_len;
367         /* check the maximum length before filling the buffer */
368         if (len > sizeof(socket_packet->icmp_packet))
369                 len = sizeof(socket_packet->icmp_packet);
370
371         INIT_LIST_HEAD(&socket_packet->list);
372         memcpy(&socket_packet->icmp_packet, icmph, len);
373         socket_packet->icmp_len = len;
374
375         spin_lock_bh(&socket_client->lock);
376
377         /* while waiting for the lock the socket_client could have been
378          * deleted
379          */
380         if (!batadv_socket_client_hash[icmph->uid]) {
381                 spin_unlock_bh(&socket_client->lock);
382                 kfree(socket_packet);
383                 return;
384         }
385
386         list_add_tail(&socket_packet->list, &socket_client->queue_list);
387         socket_client->queue_len++;
388
389         if (socket_client->queue_len > 100) {
390                 socket_packet = list_first_entry(&socket_client->queue_list,
391                                                  struct batadv_socket_packet,
392                                                  list);
393
394                 list_del(&socket_packet->list);
395                 kfree(socket_packet);
396                 socket_client->queue_len--;
397         }
398
399         spin_unlock_bh(&socket_client->lock);
400
401         wake_up(&socket_client->queue_wait);
402 }
403
404 /**
405  * batadv_socket_receive_packet() - schedule an icmp packet to be received
406  *  locally and sent to userspace.
407  * @icmph: pointer to the header of the icmp packet
408  * @icmp_len: total length of the icmp packet
409  */
410 void batadv_socket_receive_packet(struct batadv_icmp_header *icmph,
411                                   size_t icmp_len)
412 {
413         struct batadv_socket_client *hash;
414
415         hash = batadv_socket_client_hash[icmph->uid];
416         if (hash)
417                 batadv_socket_add_packet(hash, icmph, icmp_len);
418 }