blob: 59a009dc54a8ba0ddf0d258d5b077260148abecc [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * POSIX message queues filesystem for Linux.
3 *
4 * Copyright (C) 2003,2004 Krzysztof Benedyczak (golbi@mat.uni.torun.pl)
Michal Wronskif66e9282006-10-03 23:23:27 +02005 * Michal Wronski (michal.wronski@gmail.com)
Linus Torvalds1da177e2005-04-16 15:20:36 -07006 *
7 * Spinlocks: Mohamed Abbas (abbas.mohamed@intel.com)
8 * Lockless receive & send, fd based notify:
9 * Manfred Spraul (manfred@colorfullife.com)
10 *
George C. Wilson20ca73b2006-05-24 16:09:55 -050011 * Audit: George Wilson (ltcgcw@us.ibm.com)
12 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070013 * This file is released under the GPL.
14 */
15
Randy.Dunlapc59ede72006-01-11 12:17:46 -080016#include <linux/capability.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070017#include <linux/init.h>
18#include <linux/pagemap.h>
19#include <linux/file.h>
20#include <linux/mount.h>
21#include <linux/namei.h>
22#include <linux/sysctl.h>
23#include <linux/poll.h>
24#include <linux/mqueue.h>
25#include <linux/msg.h>
26#include <linux/skbuff.h>
27#include <linux/netlink.h>
28#include <linux/syscalls.h>
George C. Wilson20ca73b2006-05-24 16:09:55 -050029#include <linux/audit.h>
Jesper Juhl7ed20e12005-05-01 08:59:14 -070030#include <linux/signal.h>
Ingo Molnar5f921ae2006-03-26 01:37:17 -080031#include <linux/mutex.h>
Pavel Emelyanovb4888932007-10-18 23:40:14 -070032#include <linux/nsproxy.h>
33#include <linux/pid.h>
Serge E. Hallyn614b84c2009-04-06 19:01:08 -070034#include <linux/ipc_namespace.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090035#include <linux/slab.h>
Ingo Molnar5f921ae2006-03-26 01:37:17 -080036
Linus Torvalds1da177e2005-04-16 15:20:36 -070037#include <net/sock.h>
38#include "util.h"
39
40#define MQUEUE_MAGIC 0x19800202
41#define DIRENT_SIZE 20
42#define FILENT_SIZE 80
43
44#define SEND 0
45#define RECV 1
46
47#define STATE_NONE 0
48#define STATE_PENDING 1
49#define STATE_READY 2
50
Linus Torvalds1da177e2005-04-16 15:20:36 -070051struct ext_wait_queue { /* queue of sleeping tasks */
52 struct task_struct *task;
53 struct list_head list;
54 struct msg_msg *msg; /* ptr of loaded message */
55 int state; /* one of STATE_* values */
56};
57
58struct mqueue_inode_info {
59 spinlock_t lock;
60 struct inode vfs_inode;
61 wait_queue_head_t wait_q;
62
63 struct msg_msg **messages;
64 struct mq_attr attr;
65
66 struct sigevent notify;
Cedric Le Goatera03fcb72006-10-02 02:17:26 -070067 struct pid* notify_owner;
Adrian Bunk338cec32005-09-10 00:26:54 -070068 struct user_struct *user; /* user who created, for accounting */
Linus Torvalds1da177e2005-04-16 15:20:36 -070069 struct sock *notify_sock;
70 struct sk_buff *notify_cookie;
71
72 /* for tasks waiting for free space and messages, respectively */
73 struct ext_wait_queue e_wait_q[2];
74
75 unsigned long qsize; /* size of queue in memory (sum of all msgs) */
76};
77
Arjan van de Ven92e1d5b2007-02-12 00:55:39 -080078static const struct inode_operations mqueue_dir_inode_operations;
Arjan van de Ven9a321442007-02-12 00:55:35 -080079static const struct file_operations mqueue_file_operations;
Alexey Dobriyanb87221d2009-09-21 17:01:09 -070080static const struct super_operations mqueue_super_ops;
Linus Torvalds1da177e2005-04-16 15:20:36 -070081static void remove_notification(struct mqueue_inode_info *info);
82
Christoph Lametere18b8902006-12-06 20:33:20 -080083static struct kmem_cache *mqueue_inode_cachep;
Linus Torvalds1da177e2005-04-16 15:20:36 -070084
85static struct ctl_table_header * mq_sysctl_table;
86
87static inline struct mqueue_inode_info *MQUEUE_I(struct inode *inode)
88{
89 return container_of(inode, struct mqueue_inode_info, vfs_inode);
90}
91
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -070092/*
93 * This routine should be called with the mq_lock held.
94 */
95static inline struct ipc_namespace *__get_ns_from_inode(struct inode *inode)
Serge E. Hallyn614b84c2009-04-06 19:01:08 -070096{
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -070097 return get_ipc_ns(inode->i_sb->s_fs_info);
Serge E. Hallyn614b84c2009-04-06 19:01:08 -070098}
99
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -0700100static struct ipc_namespace *get_ns_from_inode(struct inode *inode)
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700101{
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -0700102 struct ipc_namespace *ns;
103
104 spin_lock(&mq_lock);
105 ns = __get_ns_from_inode(inode);
106 spin_unlock(&mq_lock);
107 return ns;
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700108}
109
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -0700110static struct inode *mqueue_get_inode(struct super_block *sb,
111 struct ipc_namespace *ipc_ns, int mode,
112 struct mq_attr *attr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700113{
David Howells86a264a2008-11-14 10:39:18 +1100114 struct user_struct *u = current_user();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700115 struct inode *inode;
116
117 inode = new_inode(sb);
118 if (inode) {
119 inode->i_mode = mode;
David Howells414c0702008-11-14 10:39:06 +1100120 inode->i_uid = current_fsuid();
121 inode->i_gid = current_fsgid();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122 inode->i_mtime = inode->i_ctime = inode->i_atime =
123 CURRENT_TIME;
124
125 if (S_ISREG(mode)) {
126 struct mqueue_inode_info *info;
127 struct task_struct *p = current;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128 unsigned long mq_bytes, mq_msg_tblsz;
129
130 inode->i_fop = &mqueue_file_operations;
131 inode->i_size = FILENT_SIZE;
132 /* mqueue specific info */
133 info = MQUEUE_I(inode);
134 spin_lock_init(&info->lock);
135 init_waitqueue_head(&info->wait_q);
136 INIT_LIST_HEAD(&info->e_wait_q[0].list);
137 INIT_LIST_HEAD(&info->e_wait_q[1].list);
Cedric Le Goatera03fcb72006-10-02 02:17:26 -0700138 info->notify_owner = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139 info->qsize = 0;
140 info->user = NULL; /* set when all is ok */
141 memset(&info->attr, 0, sizeof(info->attr));
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700142 info->attr.mq_maxmsg = ipc_ns->mq_msg_max;
143 info->attr.mq_msgsize = ipc_ns->mq_msgsize_max;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144 if (attr) {
145 info->attr.mq_maxmsg = attr->mq_maxmsg;
146 info->attr.mq_msgsize = attr->mq_msgsize;
147 }
148 mq_msg_tblsz = info->attr.mq_maxmsg * sizeof(struct msg_msg *);
André Goddard Rosac8308b12010-02-23 04:04:23 -0300149 info->messages = kmalloc(mq_msg_tblsz, GFP_KERNEL);
150 if (!info->messages)
151 goto out_inode;
152
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153 mq_bytes = (mq_msg_tblsz +
154 (info->attr.mq_maxmsg * info->attr.mq_msgsize));
155
156 spin_lock(&mq_lock);
157 if (u->mq_bytes + mq_bytes < u->mq_bytes ||
158 u->mq_bytes + mq_bytes >
Jiri Slabyf1eb1332010-03-10 15:23:05 -0800159 task_rlimit(p, RLIMIT_MSGQUEUE)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700160 spin_unlock(&mq_lock);
André Goddard Rosaa3ed2a12010-05-11 14:07:03 -0700161 /* mqueue_delete_inode() releases info->messages */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162 goto out_inode;
163 }
164 u->mq_bytes += mq_bytes;
165 spin_unlock(&mq_lock);
166
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167 /* all is ok */
168 info->user = get_uid(u);
169 } else if (S_ISDIR(mode)) {
Dave Hansend8c76e62006-09-30 23:29:04 -0700170 inc_nlink(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700171 /* Some things misbehave if size == 0 on a directory */
172 inode->i_size = 2 * DIRENT_SIZE;
173 inode->i_op = &mqueue_dir_inode_operations;
174 inode->i_fop = &simple_dir_operations;
175 }
176 }
177 return inode;
178out_inode:
179 make_bad_inode(inode);
180 iput(inode);
181 return NULL;
182}
183
184static int mqueue_fill_super(struct super_block *sb, void *data, int silent)
185{
186 struct inode *inode;
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -0700187 struct ipc_namespace *ns = data;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300188 int error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189
190 sb->s_blocksize = PAGE_CACHE_SIZE;
191 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
192 sb->s_magic = MQUEUE_MAGIC;
193 sb->s_op = &mqueue_super_ops;
194
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -0700195 inode = mqueue_get_inode(sb, ns, S_IFDIR | S_ISVTX | S_IRWXUGO,
196 NULL);
197 if (!inode) {
198 error = -ENOMEM;
199 goto out;
200 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201
202 sb->s_root = d_alloc_root(inode);
203 if (!sb->s_root) {
204 iput(inode);
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -0700205 error = -ENOMEM;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300206 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207 }
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300208 error = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -0700210out:
211 return error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700212}
213
David Howells454e2392006-06-23 02:02:57 -0700214static int mqueue_get_sb(struct file_system_type *fs_type,
215 int flags, const char *dev_name,
216 void *data, struct vfsmount *mnt)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217{
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -0700218 if (!(flags & MS_KERNMOUNT))
219 data = current->nsproxy->ipc_ns;
220 return get_sb_ns(fs_type, flags, data, mqueue_fill_super, mnt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221}
222
Alexey Dobriyan51cc5062008-07-25 19:45:34 -0700223static void init_once(void *foo)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700224{
225 struct mqueue_inode_info *p = (struct mqueue_inode_info *) foo;
226
Christoph Lametera35afb82007-05-16 22:10:57 -0700227 inode_init_once(&p->vfs_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228}
229
230static struct inode *mqueue_alloc_inode(struct super_block *sb)
231{
232 struct mqueue_inode_info *ei;
233
Christoph Lametere94b1762006-12-06 20:33:17 -0800234 ei = kmem_cache_alloc(mqueue_inode_cachep, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700235 if (!ei)
236 return NULL;
237 return &ei->vfs_inode;
238}
239
240static void mqueue_destroy_inode(struct inode *inode)
241{
242 kmem_cache_free(mqueue_inode_cachep, MQUEUE_I(inode));
243}
244
245static void mqueue_delete_inode(struct inode *inode)
246{
247 struct mqueue_inode_info *info;
248 struct user_struct *user;
249 unsigned long mq_bytes;
250 int i;
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -0700251 struct ipc_namespace *ipc_ns;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252
253 if (S_ISDIR(inode->i_mode)) {
254 clear_inode(inode);
255 return;
256 }
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -0700257 ipc_ns = get_ns_from_inode(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700258 info = MQUEUE_I(inode);
259 spin_lock(&info->lock);
260 for (i = 0; i < info->attr.mq_curmsgs; i++)
261 free_msg(info->messages[i]);
262 kfree(info->messages);
263 spin_unlock(&info->lock);
264
265 clear_inode(inode);
266
André Goddard Rosa8834cf72010-02-23 04:04:24 -0300267 /* Total amount of bytes accounted for the mqueue */
268 mq_bytes = info->attr.mq_maxmsg * (sizeof(struct msg_msg *)
269 + info->attr.mq_msgsize);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700270 user = info->user;
271 if (user) {
272 spin_lock(&mq_lock);
273 user->mq_bytes -= mq_bytes;
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -0700274 /*
275 * get_ns_from_inode() ensures that the
276 * (ipc_ns = sb->s_fs_info) is either a valid ipc_ns
277 * to which we now hold a reference, or it is NULL.
278 * We can't put it here under mq_lock, though.
279 */
280 if (ipc_ns)
281 ipc_ns->mq_queues_count--;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700282 spin_unlock(&mq_lock);
283 free_uid(user);
284 }
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -0700285 if (ipc_ns)
286 put_ipc_ns(ipc_ns);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700287}
288
289static int mqueue_create(struct inode *dir, struct dentry *dentry,
290 int mode, struct nameidata *nd)
291{
292 struct inode *inode;
293 struct mq_attr *attr = dentry->d_fsdata;
294 int error;
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -0700295 struct ipc_namespace *ipc_ns;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700296
297 spin_lock(&mq_lock);
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -0700298 ipc_ns = __get_ns_from_inode(dir);
299 if (!ipc_ns) {
300 error = -EACCES;
301 goto out_unlock;
302 }
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700303 if (ipc_ns->mq_queues_count >= ipc_ns->mq_queues_max &&
304 !capable(CAP_SYS_RESOURCE)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700305 error = -ENOSPC;
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700306 goto out_unlock;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700307 }
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700308 ipc_ns->mq_queues_count++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700309 spin_unlock(&mq_lock);
310
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -0700311 inode = mqueue_get_inode(dir->i_sb, ipc_ns, mode, attr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700312 if (!inode) {
313 error = -ENOMEM;
314 spin_lock(&mq_lock);
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700315 ipc_ns->mq_queues_count--;
316 goto out_unlock;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700317 }
318
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -0700319 put_ipc_ns(ipc_ns);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700320 dir->i_size += DIRENT_SIZE;
321 dir->i_ctime = dir->i_mtime = dir->i_atime = CURRENT_TIME;
322
323 d_instantiate(dentry, inode);
324 dget(dentry);
325 return 0;
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700326out_unlock:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700327 spin_unlock(&mq_lock);
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -0700328 if (ipc_ns)
329 put_ipc_ns(ipc_ns);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700330 return error;
331}
332
333static int mqueue_unlink(struct inode *dir, struct dentry *dentry)
334{
335 struct inode *inode = dentry->d_inode;
336
337 dir->i_ctime = dir->i_mtime = dir->i_atime = CURRENT_TIME;
338 dir->i_size -= DIRENT_SIZE;
Dave Hansen9a53c3a2006-09-30 23:29:03 -0700339 drop_nlink(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700340 dput(dentry);
341 return 0;
342}
343
344/*
345* This is routine for system read from queue file.
346* To avoid mess with doing here some sort of mq_receive we allow
347* to read only queue size & notification info (the only values
348* that are interesting from user point of view and aren't accessible
349* through std routines)
350*/
351static ssize_t mqueue_read_file(struct file *filp, char __user *u_data,
Akinobu Mitaf1a43f92008-07-25 01:48:07 -0700352 size_t count, loff_t *off)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700353{
Josef Sipek6d630792006-12-08 02:37:11 -0800354 struct mqueue_inode_info *info = MQUEUE_I(filp->f_path.dentry->d_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700355 char buffer[FILENT_SIZE];
Akinobu Mitaf1a43f92008-07-25 01:48:07 -0700356 ssize_t ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700357
358 spin_lock(&info->lock);
359 snprintf(buffer, sizeof(buffer),
360 "QSIZE:%-10lu NOTIFY:%-5d SIGNO:%-5d NOTIFY_PID:%-6d\n",
361 info->qsize,
362 info->notify_owner ? info->notify.sigev_notify : 0,
363 (info->notify_owner &&
364 info->notify.sigev_notify == SIGEV_SIGNAL) ?
365 info->notify.sigev_signo : 0,
Pavel Emelyanov6c5f3e72008-02-08 04:19:20 -0800366 pid_vnr(info->notify_owner));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700367 spin_unlock(&info->lock);
368 buffer[sizeof(buffer)-1] = '\0';
Linus Torvalds1da177e2005-04-16 15:20:36 -0700369
Akinobu Mitaf1a43f92008-07-25 01:48:07 -0700370 ret = simple_read_from_buffer(u_data, count, off, buffer,
371 strlen(buffer));
372 if (ret <= 0)
373 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700374
Josef Sipek6d630792006-12-08 02:37:11 -0800375 filp->f_path.dentry->d_inode->i_atime = filp->f_path.dentry->d_inode->i_ctime = CURRENT_TIME;
Akinobu Mitaf1a43f92008-07-25 01:48:07 -0700376 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700377}
378
Miklos Szeredi75e1fcc2006-06-23 02:05:12 -0700379static int mqueue_flush_file(struct file *filp, fl_owner_t id)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700380{
Josef Sipek6d630792006-12-08 02:37:11 -0800381 struct mqueue_inode_info *info = MQUEUE_I(filp->f_path.dentry->d_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700382
383 spin_lock(&info->lock);
Cedric Le Goatera03fcb72006-10-02 02:17:26 -0700384 if (task_tgid(current) == info->notify_owner)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700385 remove_notification(info);
386
387 spin_unlock(&info->lock);
388 return 0;
389}
390
391static unsigned int mqueue_poll_file(struct file *filp, struct poll_table_struct *poll_tab)
392{
Josef Sipek6d630792006-12-08 02:37:11 -0800393 struct mqueue_inode_info *info = MQUEUE_I(filp->f_path.dentry->d_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700394 int retval = 0;
395
396 poll_wait(filp, &info->wait_q, poll_tab);
397
398 spin_lock(&info->lock);
399 if (info->attr.mq_curmsgs)
400 retval = POLLIN | POLLRDNORM;
401
402 if (info->attr.mq_curmsgs < info->attr.mq_maxmsg)
403 retval |= POLLOUT | POLLWRNORM;
404 spin_unlock(&info->lock);
405
406 return retval;
407}
408
409/* Adds current to info->e_wait_q[sr] before element with smaller prio */
410static void wq_add(struct mqueue_inode_info *info, int sr,
411 struct ext_wait_queue *ewp)
412{
413 struct ext_wait_queue *walk;
414
415 ewp->task = current;
416
417 list_for_each_entry(walk, &info->e_wait_q[sr].list, list) {
418 if (walk->task->static_prio <= current->static_prio) {
419 list_add_tail(&ewp->list, &walk->list);
420 return;
421 }
422 }
423 list_add_tail(&ewp->list, &info->e_wait_q[sr].list);
424}
425
426/*
427 * Puts current task to sleep. Caller must hold queue lock. After return
428 * lock isn't held.
429 * sr: SEND or RECV
430 */
431static int wq_sleep(struct mqueue_inode_info *info, int sr,
432 long timeout, struct ext_wait_queue *ewp)
433{
434 int retval;
435 signed long time;
436
437 wq_add(info, sr, ewp);
438
439 for (;;) {
440 set_current_state(TASK_INTERRUPTIBLE);
441
442 spin_unlock(&info->lock);
443 time = schedule_timeout(timeout);
444
445 while (ewp->state == STATE_PENDING)
446 cpu_relax();
447
448 if (ewp->state == STATE_READY) {
449 retval = 0;
450 goto out;
451 }
452 spin_lock(&info->lock);
453 if (ewp->state == STATE_READY) {
454 retval = 0;
455 goto out_unlock;
456 }
457 if (signal_pending(current)) {
458 retval = -ERESTARTSYS;
459 break;
460 }
461 if (time == 0) {
462 retval = -ETIMEDOUT;
463 break;
464 }
465 }
466 list_del(&ewp->list);
467out_unlock:
468 spin_unlock(&info->lock);
469out:
470 return retval;
471}
472
473/*
474 * Returns waiting task that should be serviced first or NULL if none exists
475 */
476static struct ext_wait_queue *wq_get_first_waiter(
477 struct mqueue_inode_info *info, int sr)
478{
479 struct list_head *ptr;
480
481 ptr = info->e_wait_q[sr].list.prev;
482 if (ptr == &info->e_wait_q[sr].list)
483 return NULL;
484 return list_entry(ptr, struct ext_wait_queue, list);
485}
486
487/* Auxiliary functions to manipulate messages' list */
488static void msg_insert(struct msg_msg *ptr, struct mqueue_inode_info *info)
489{
490 int k;
491
492 k = info->attr.mq_curmsgs - 1;
493 while (k >= 0 && info->messages[k]->m_type >= ptr->m_type) {
494 info->messages[k + 1] = info->messages[k];
495 k--;
496 }
497 info->attr.mq_curmsgs++;
498 info->qsize += ptr->m_ts;
499 info->messages[k + 1] = ptr;
500}
501
502static inline struct msg_msg *msg_get(struct mqueue_inode_info *info)
503{
504 info->qsize -= info->messages[--info->attr.mq_curmsgs]->m_ts;
505 return info->messages[info->attr.mq_curmsgs];
506}
507
508static inline void set_cookie(struct sk_buff *skb, char code)
509{
510 ((char*)skb->data)[NOTIFY_COOKIE_LEN-1] = code;
511}
512
513/*
514 * The next function is only to split too long sys_mq_timedsend
515 */
516static void __do_notify(struct mqueue_inode_info *info)
517{
518 /* notification
519 * invoked when there is registered process and there isn't process
520 * waiting synchronously for message AND state of queue changed from
521 * empty to not empty. Here we are sure that no one is waiting
522 * synchronously. */
523 if (info->notify_owner &&
524 info->attr.mq_curmsgs == 1) {
525 struct siginfo sig_i;
526 switch (info->notify.sigev_notify) {
527 case SIGEV_NONE:
528 break;
529 case SIGEV_SIGNAL:
530 /* sends signal */
531
532 sig_i.si_signo = info->notify.sigev_signo;
533 sig_i.si_errno = 0;
534 sig_i.si_code = SI_MESGQ;
535 sig_i.si_value = info->notify.sigev_value;
Sukadev Bhattiprolua6684992009-01-07 18:08:50 -0800536 sig_i.si_pid = task_tgid_nr_ns(current,
537 ns_of_pid(info->notify_owner));
David Howells414c0702008-11-14 10:39:06 +1100538 sig_i.si_uid = current_uid();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700539
Cedric Le Goatera03fcb72006-10-02 02:17:26 -0700540 kill_pid_info(info->notify.sigev_signo,
541 &sig_i, info->notify_owner);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700542 break;
543 case SIGEV_THREAD:
544 set_cookie(info->notify_cookie, NOTIFY_WOKENUP);
Denis V. Lunev7ee015e2007-10-10 21:14:03 -0700545 netlink_sendskb(info->notify_sock, info->notify_cookie);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700546 break;
547 }
548 /* after notification unregisters process */
Cedric Le Goatera03fcb72006-10-02 02:17:26 -0700549 put_pid(info->notify_owner);
550 info->notify_owner = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700551 }
552 wake_up(&info->wait_q);
553}
554
Al Viroc32c8af2008-12-14 03:46:48 -0500555static long prepare_timeout(struct timespec *p)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700556{
Al Viroc32c8af2008-12-14 03:46:48 -0500557 struct timespec nowts;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700558 long timeout;
559
Al Viroc32c8af2008-12-14 03:46:48 -0500560 if (p) {
561 if (unlikely(p->tv_nsec < 0 || p->tv_sec < 0
562 || p->tv_nsec >= NSEC_PER_SEC))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700563 return -EINVAL;
564 nowts = CURRENT_TIME;
565 /* first subtract as jiffies can't be too big */
Al Viroc32c8af2008-12-14 03:46:48 -0500566 p->tv_sec -= nowts.tv_sec;
567 if (p->tv_nsec < nowts.tv_nsec) {
568 p->tv_nsec += NSEC_PER_SEC;
569 p->tv_sec--;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700570 }
Al Viroc32c8af2008-12-14 03:46:48 -0500571 p->tv_nsec -= nowts.tv_nsec;
572 if (p->tv_sec < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700573 return 0;
574
Al Viroc32c8af2008-12-14 03:46:48 -0500575 timeout = timespec_to_jiffies(p) + 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700576 } else
577 return MAX_SCHEDULE_TIMEOUT;
578
579 return timeout;
580}
581
582static void remove_notification(struct mqueue_inode_info *info)
583{
Cedric Le Goatera03fcb72006-10-02 02:17:26 -0700584 if (info->notify_owner != NULL &&
Linus Torvalds1da177e2005-04-16 15:20:36 -0700585 info->notify.sigev_notify == SIGEV_THREAD) {
586 set_cookie(info->notify_cookie, NOTIFY_REMOVED);
Denis V. Lunev7ee015e2007-10-10 21:14:03 -0700587 netlink_sendskb(info->notify_sock, info->notify_cookie);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700588 }
Cedric Le Goatera03fcb72006-10-02 02:17:26 -0700589 put_pid(info->notify_owner);
590 info->notify_owner = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700591}
592
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700593static int mq_attr_ok(struct ipc_namespace *ipc_ns, struct mq_attr *attr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700594{
595 if (attr->mq_maxmsg <= 0 || attr->mq_msgsize <= 0)
596 return 0;
597 if (capable(CAP_SYS_RESOURCE)) {
598 if (attr->mq_maxmsg > HARD_MSGMAX)
599 return 0;
600 } else {
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700601 if (attr->mq_maxmsg > ipc_ns->mq_msg_max ||
602 attr->mq_msgsize > ipc_ns->mq_msgsize_max)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700603 return 0;
604 }
605 /* check for overflow */
606 if (attr->mq_msgsize > ULONG_MAX/attr->mq_maxmsg)
607 return 0;
André Goddard Rosa8834cf72010-02-23 04:04:24 -0300608 if ((unsigned long)(attr->mq_maxmsg * (attr->mq_msgsize
609 + sizeof (struct msg_msg *))) <
Linus Torvalds1da177e2005-04-16 15:20:36 -0700610 (unsigned long)(attr->mq_maxmsg * attr->mq_msgsize))
611 return 0;
612 return 1;
613}
614
615/*
616 * Invoked when creating a new queue via sys_mq_open
617 */
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700618static struct file *do_create(struct ipc_namespace *ipc_ns, struct dentry *dir,
619 struct dentry *dentry, int oflag, mode_t mode,
620 struct mq_attr *attr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700621{
David Howells745ca242008-11-14 10:39:22 +1100622 const struct cred *cred = current_cred();
Dave Hansen4a3fd212008-02-15 14:37:48 -0800623 struct file *result;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700624 int ret;
625
Al Viro564f6992008-12-14 04:02:26 -0500626 if (attr) {
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300627 if (!mq_attr_ok(ipc_ns, attr)) {
628 ret = -EINVAL;
Alexander Viro7c7dce92006-01-14 15:29:55 -0500629 goto out;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300630 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700631 /* store for use during create */
Al Viro564f6992008-12-14 04:02:26 -0500632 dentry->d_fsdata = attr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700633 }
634
Al Viroce3b0f82009-03-29 19:08:22 -0400635 mode &= ~current_umask();
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700636 ret = mnt_want_write(ipc_ns->mq_mnt);
Dave Hansen4a3fd212008-02-15 14:37:48 -0800637 if (ret)
638 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700639 ret = vfs_create(dir->d_inode, dentry, mode, NULL);
640 dentry->d_fsdata = NULL;
641 if (ret)
Dave Hansen4a3fd212008-02-15 14:37:48 -0800642 goto out_drop_write;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700643
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700644 result = dentry_open(dentry, ipc_ns->mq_mnt, oflag, cred);
Dave Hansen4a3fd212008-02-15 14:37:48 -0800645 /*
646 * dentry_open() took a persistent mnt_want_write(),
647 * so we can now drop this one.
648 */
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700649 mnt_drop_write(ipc_ns->mq_mnt);
Dave Hansen4a3fd212008-02-15 14:37:48 -0800650 return result;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700651
Dave Hansen4a3fd212008-02-15 14:37:48 -0800652out_drop_write:
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700653 mnt_drop_write(ipc_ns->mq_mnt);
Alexander Viro7c7dce92006-01-14 15:29:55 -0500654out:
655 dput(dentry);
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700656 mntput(ipc_ns->mq_mnt);
Alexander Viro7c7dce92006-01-14 15:29:55 -0500657 return ERR_PTR(ret);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700658}
659
660/* Opens existing queue */
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700661static struct file *do_open(struct ipc_namespace *ipc_ns,
662 struct dentry *dentry, int oflag)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700663{
André Goddard Rosa04db0dd2010-02-23 04:04:25 -0300664 int ret;
David Howells745ca242008-11-14 10:39:22 +1100665 const struct cred *cred = current_cred();
666
667 static const int oflag2acc[O_ACCMODE] = { MAY_READ, MAY_WRITE,
668 MAY_READ | MAY_WRITE };
Linus Torvalds1da177e2005-04-16 15:20:36 -0700669
Alexander Viro7c7dce92006-01-14 15:29:55 -0500670 if ((oflag & O_ACCMODE) == (O_RDWR | O_WRONLY)) {
André Goddard Rosa04db0dd2010-02-23 04:04:25 -0300671 ret = -EINVAL;
672 goto err;
Alexander Viro7c7dce92006-01-14 15:29:55 -0500673 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700674
Al Virof419a2e2008-07-22 00:07:17 -0400675 if (inode_permission(dentry->d_inode, oflag2acc[oflag & O_ACCMODE])) {
André Goddard Rosa04db0dd2010-02-23 04:04:25 -0300676 ret = -EACCES;
677 goto err;
Alexander Viro7c7dce92006-01-14 15:29:55 -0500678 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700679
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700680 return dentry_open(dentry, ipc_ns->mq_mnt, oflag, cred);
André Goddard Rosa04db0dd2010-02-23 04:04:25 -0300681
682err:
683 dput(dentry);
684 mntput(ipc_ns->mq_mnt);
685 return ERR_PTR(ret);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700686}
687
Heiko Carstensd5460c92009-01-14 14:14:27 +0100688SYSCALL_DEFINE4(mq_open, const char __user *, u_name, int, oflag, mode_t, mode,
689 struct mq_attr __user *, u_attr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700690{
691 struct dentry *dentry;
692 struct file *filp;
693 char *name;
Al Viro564f6992008-12-14 04:02:26 -0500694 struct mq_attr attr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700695 int fd, error;
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -0700696 struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700697
Al Viro564f6992008-12-14 04:02:26 -0500698 if (u_attr && copy_from_user(&attr, u_attr, sizeof(struct mq_attr)))
699 return -EFAULT;
700
701 audit_mq_open(oflag, mode, u_attr ? &attr : NULL);
George C. Wilson20ca73b2006-05-24 16:09:55 -0500702
Linus Torvalds1da177e2005-04-16 15:20:36 -0700703 if (IS_ERR(name = getname(u_name)))
704 return PTR_ERR(name);
705
Ulrich Drepper269f2132008-05-03 15:28:45 -0400706 fd = get_unused_fd_flags(O_CLOEXEC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700707 if (fd < 0)
708 goto out_putname;
709
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700710 mutex_lock(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex);
711 dentry = lookup_one_len(name, ipc_ns->mq_mnt->mnt_root, strlen(name));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700712 if (IS_ERR(dentry)) {
713 error = PTR_ERR(dentry);
André Goddard Rosa4294a8e2010-02-23 04:04:28 -0300714 goto out_putfd;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700715 }
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700716 mntget(ipc_ns->mq_mnt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700717
718 if (oflag & O_CREAT) {
719 if (dentry->d_inode) { /* entry already exists */
Al Viro5a190ae2007-06-07 12:19:32 -0400720 audit_inode(name, dentry);
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300721 if (oflag & O_EXCL) {
722 error = -EEXIST;
Alexander Viro7c7dce92006-01-14 15:29:55 -0500723 goto out;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300724 }
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700725 filp = do_open(ipc_ns, dentry, oflag);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700726 } else {
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700727 filp = do_create(ipc_ns, ipc_ns->mq_mnt->mnt_root,
728 dentry, oflag, mode,
Al Viro564f6992008-12-14 04:02:26 -0500729 u_attr ? &attr : NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700730 }
Alexander Viro7c7dce92006-01-14 15:29:55 -0500731 } else {
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300732 if (!dentry->d_inode) {
733 error = -ENOENT;
Alexander Viro7c7dce92006-01-14 15:29:55 -0500734 goto out;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300735 }
Al Viro5a190ae2007-06-07 12:19:32 -0400736 audit_inode(name, dentry);
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700737 filp = do_open(ipc_ns, dentry, oflag);
Alexander Viro7c7dce92006-01-14 15:29:55 -0500738 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700739
740 if (IS_ERR(filp)) {
741 error = PTR_ERR(filp);
742 goto out_putfd;
743 }
744
Linus Torvalds1da177e2005-04-16 15:20:36 -0700745 fd_install(fd, filp);
746 goto out_upsem;
747
Alexander Viro7c7dce92006-01-14 15:29:55 -0500748out:
749 dput(dentry);
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700750 mntput(ipc_ns->mq_mnt);
Alexander Viro7c7dce92006-01-14 15:29:55 -0500751out_putfd:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700752 put_unused_fd(fd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700753 fd = error;
754out_upsem:
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700755 mutex_unlock(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700756out_putname:
757 putname(name);
758 return fd;
759}
760
Heiko Carstensd5460c92009-01-14 14:14:27 +0100761SYSCALL_DEFINE1(mq_unlink, const char __user *, u_name)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700762{
763 int err;
764 char *name;
765 struct dentry *dentry;
766 struct inode *inode = NULL;
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -0700767 struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700768
769 name = getname(u_name);
770 if (IS_ERR(name))
771 return PTR_ERR(name);
772
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700773 mutex_lock_nested(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex,
Peter Zijlstra7a434812007-03-06 01:42:09 -0800774 I_MUTEX_PARENT);
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700775 dentry = lookup_one_len(name, ipc_ns->mq_mnt->mnt_root, strlen(name));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700776 if (IS_ERR(dentry)) {
777 err = PTR_ERR(dentry);
778 goto out_unlock;
779 }
780
781 if (!dentry->d_inode) {
782 err = -ENOENT;
783 goto out_err;
784 }
785
786 inode = dentry->d_inode;
787 if (inode)
788 atomic_inc(&inode->i_count);
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700789 err = mnt_want_write(ipc_ns->mq_mnt);
Dave Hansen06227532008-02-15 14:37:34 -0800790 if (err)
791 goto out_err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700792 err = vfs_unlink(dentry->d_parent->d_inode, dentry);
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700793 mnt_drop_write(ipc_ns->mq_mnt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700794out_err:
795 dput(dentry);
796
797out_unlock:
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700798 mutex_unlock(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700799 putname(name);
800 if (inode)
801 iput(inode);
802
803 return err;
804}
805
806/* Pipelined send and receive functions.
807 *
808 * If a receiver finds no waiting message, then it registers itself in the
809 * list of waiting receivers. A sender checks that list before adding the new
810 * message into the message array. If there is a waiting receiver, then it
811 * bypasses the message array and directly hands the message over to the
812 * receiver.
813 * The receiver accepts the message and returns without grabbing the queue
814 * spinlock. Therefore an intermediate STATE_PENDING state and memory barriers
815 * are necessary. The same algorithm is used for sysv semaphores, see
Serge E. Hallyn7b7a3172006-03-28 01:56:23 -0800816 * ipc/sem.c for more details.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700817 *
818 * The same algorithm is used for senders.
819 */
820
821/* pipelined_send() - send a message directly to the task waiting in
822 * sys_mq_timedreceive() (without inserting message into a queue).
823 */
824static inline void pipelined_send(struct mqueue_inode_info *info,
825 struct msg_msg *message,
826 struct ext_wait_queue *receiver)
827{
828 receiver->msg = message;
829 list_del(&receiver->list);
830 receiver->state = STATE_PENDING;
831 wake_up_process(receiver->task);
akpm@osdl.orgd59dd462005-05-01 08:58:47 -0700832 smp_wmb();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700833 receiver->state = STATE_READY;
834}
835
836/* pipelined_receive() - if there is task waiting in sys_mq_timedsend()
837 * gets its message and put to the queue (we have one free place for sure). */
838static inline void pipelined_receive(struct mqueue_inode_info *info)
839{
840 struct ext_wait_queue *sender = wq_get_first_waiter(info, SEND);
841
842 if (!sender) {
843 /* for poll */
844 wake_up_interruptible(&info->wait_q);
845 return;
846 }
847 msg_insert(sender->msg, info);
848 list_del(&sender->list);
849 sender->state = STATE_PENDING;
850 wake_up_process(sender->task);
akpm@osdl.orgd59dd462005-05-01 08:58:47 -0700851 smp_wmb();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700852 sender->state = STATE_READY;
853}
854
Heiko Carstensc4ea37c2009-01-14 14:14:28 +0100855SYSCALL_DEFINE5(mq_timedsend, mqd_t, mqdes, const char __user *, u_msg_ptr,
856 size_t, msg_len, unsigned int, msg_prio,
857 const struct timespec __user *, u_abs_timeout)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700858{
859 struct file *filp;
860 struct inode *inode;
861 struct ext_wait_queue wait;
862 struct ext_wait_queue *receiver;
863 struct msg_msg *msg_ptr;
864 struct mqueue_inode_info *info;
Al Viroc32c8af2008-12-14 03:46:48 -0500865 struct timespec ts, *p = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700866 long timeout;
867 int ret;
868
Al Viroc32c8af2008-12-14 03:46:48 -0500869 if (u_abs_timeout) {
870 if (copy_from_user(&ts, u_abs_timeout,
871 sizeof(struct timespec)))
872 return -EFAULT;
873 p = &ts;
874 }
George C. Wilson20ca73b2006-05-24 16:09:55 -0500875
Linus Torvalds1da177e2005-04-16 15:20:36 -0700876 if (unlikely(msg_prio >= (unsigned long) MQ_PRIO_MAX))
877 return -EINVAL;
878
Al Viroc32c8af2008-12-14 03:46:48 -0500879 audit_mq_sendrecv(mqdes, msg_len, msg_prio, p);
880 timeout = prepare_timeout(p);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700881
Linus Torvalds1da177e2005-04-16 15:20:36 -0700882 filp = fget(mqdes);
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300883 if (unlikely(!filp)) {
884 ret = -EBADF;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700885 goto out;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300886 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700887
Josef Sipek6d630792006-12-08 02:37:11 -0800888 inode = filp->f_path.dentry->d_inode;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300889 if (unlikely(filp->f_op != &mqueue_file_operations)) {
890 ret = -EBADF;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700891 goto out_fput;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300892 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700893 info = MQUEUE_I(inode);
Al Viro5a190ae2007-06-07 12:19:32 -0400894 audit_inode(NULL, filp->f_path.dentry);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700895
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300896 if (unlikely(!(filp->f_mode & FMODE_WRITE))) {
897 ret = -EBADF;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700898 goto out_fput;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300899 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700900
901 if (unlikely(msg_len > info->attr.mq_msgsize)) {
902 ret = -EMSGSIZE;
903 goto out_fput;
904 }
905
906 /* First try to allocate memory, before doing anything with
907 * existing queues. */
908 msg_ptr = load_msg(u_msg_ptr, msg_len);
909 if (IS_ERR(msg_ptr)) {
910 ret = PTR_ERR(msg_ptr);
911 goto out_fput;
912 }
913 msg_ptr->m_ts = msg_len;
914 msg_ptr->m_type = msg_prio;
915
916 spin_lock(&info->lock);
917
918 if (info->attr.mq_curmsgs == info->attr.mq_maxmsg) {
919 if (filp->f_flags & O_NONBLOCK) {
920 spin_unlock(&info->lock);
921 ret = -EAGAIN;
922 } else if (unlikely(timeout < 0)) {
923 spin_unlock(&info->lock);
924 ret = timeout;
925 } else {
926 wait.task = current;
927 wait.msg = (void *) msg_ptr;
928 wait.state = STATE_NONE;
929 ret = wq_sleep(info, SEND, timeout, &wait);
930 }
931 if (ret < 0)
932 free_msg(msg_ptr);
933 } else {
934 receiver = wq_get_first_waiter(info, RECV);
935 if (receiver) {
936 pipelined_send(info, msg_ptr, receiver);
937 } else {
938 /* adds message to the queue */
939 msg_insert(msg_ptr, info);
940 __do_notify(info);
941 }
942 inode->i_atime = inode->i_mtime = inode->i_ctime =
943 CURRENT_TIME;
944 spin_unlock(&info->lock);
945 ret = 0;
946 }
947out_fput:
948 fput(filp);
949out:
950 return ret;
951}
952
Heiko Carstensc4ea37c2009-01-14 14:14:28 +0100953SYSCALL_DEFINE5(mq_timedreceive, mqd_t, mqdes, char __user *, u_msg_ptr,
954 size_t, msg_len, unsigned int __user *, u_msg_prio,
955 const struct timespec __user *, u_abs_timeout)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700956{
957 long timeout;
958 ssize_t ret;
959 struct msg_msg *msg_ptr;
960 struct file *filp;
961 struct inode *inode;
962 struct mqueue_inode_info *info;
963 struct ext_wait_queue wait;
Al Viroc32c8af2008-12-14 03:46:48 -0500964 struct timespec ts, *p = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700965
Al Viroc32c8af2008-12-14 03:46:48 -0500966 if (u_abs_timeout) {
967 if (copy_from_user(&ts, u_abs_timeout,
968 sizeof(struct timespec)))
969 return -EFAULT;
970 p = &ts;
971 }
George C. Wilson20ca73b2006-05-24 16:09:55 -0500972
Al Viroc32c8af2008-12-14 03:46:48 -0500973 audit_mq_sendrecv(mqdes, msg_len, 0, p);
974 timeout = prepare_timeout(p);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700975
Linus Torvalds1da177e2005-04-16 15:20:36 -0700976 filp = fget(mqdes);
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300977 if (unlikely(!filp)) {
978 ret = -EBADF;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700979 goto out;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300980 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700981
Josef Sipek6d630792006-12-08 02:37:11 -0800982 inode = filp->f_path.dentry->d_inode;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300983 if (unlikely(filp->f_op != &mqueue_file_operations)) {
984 ret = -EBADF;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700985 goto out_fput;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300986 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700987 info = MQUEUE_I(inode);
Al Viro5a190ae2007-06-07 12:19:32 -0400988 audit_inode(NULL, filp->f_path.dentry);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700989
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300990 if (unlikely(!(filp->f_mode & FMODE_READ))) {
991 ret = -EBADF;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700992 goto out_fput;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300993 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700994
995 /* checks if buffer is big enough */
996 if (unlikely(msg_len < info->attr.mq_msgsize)) {
997 ret = -EMSGSIZE;
998 goto out_fput;
999 }
1000
1001 spin_lock(&info->lock);
1002 if (info->attr.mq_curmsgs == 0) {
1003 if (filp->f_flags & O_NONBLOCK) {
1004 spin_unlock(&info->lock);
1005 ret = -EAGAIN;
1006 msg_ptr = NULL;
1007 } else if (unlikely(timeout < 0)) {
1008 spin_unlock(&info->lock);
1009 ret = timeout;
1010 msg_ptr = NULL;
1011 } else {
1012 wait.task = current;
1013 wait.state = STATE_NONE;
1014 ret = wq_sleep(info, RECV, timeout, &wait);
1015 msg_ptr = wait.msg;
1016 }
1017 } else {
1018 msg_ptr = msg_get(info);
1019
1020 inode->i_atime = inode->i_mtime = inode->i_ctime =
1021 CURRENT_TIME;
1022
1023 /* There is now free space in queue. */
1024 pipelined_receive(info);
1025 spin_unlock(&info->lock);
1026 ret = 0;
1027 }
1028 if (ret == 0) {
1029 ret = msg_ptr->m_ts;
1030
1031 if ((u_msg_prio && put_user(msg_ptr->m_type, u_msg_prio)) ||
1032 store_msg(u_msg_ptr, msg_ptr, msg_ptr->m_ts)) {
1033 ret = -EFAULT;
1034 }
1035 free_msg(msg_ptr);
1036 }
1037out_fput:
1038 fput(filp);
1039out:
1040 return ret;
1041}
1042
1043/*
1044 * Notes: the case when user wants us to deregister (with NULL as pointer)
1045 * and he isn't currently owner of notification, will be silently discarded.
1046 * It isn't explicitly defined in the POSIX.
1047 */
Heiko Carstensc4ea37c2009-01-14 14:14:28 +01001048SYSCALL_DEFINE2(mq_notify, mqd_t, mqdes,
1049 const struct sigevent __user *, u_notification)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001050{
1051 int ret;
1052 struct file *filp;
1053 struct sock *sock;
1054 struct inode *inode;
1055 struct sigevent notification;
1056 struct mqueue_inode_info *info;
1057 struct sk_buff *nc;
1058
Al Viro20114f72008-12-10 07:16:12 -05001059 if (u_notification) {
1060 if (copy_from_user(&notification, u_notification,
1061 sizeof(struct sigevent)))
1062 return -EFAULT;
1063 }
1064
1065 audit_mq_notify(mqdes, u_notification ? &notification : NULL);
George C. Wilson20ca73b2006-05-24 16:09:55 -05001066
Linus Torvalds1da177e2005-04-16 15:20:36 -07001067 nc = NULL;
1068 sock = NULL;
1069 if (u_notification != NULL) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001070 if (unlikely(notification.sigev_notify != SIGEV_NONE &&
1071 notification.sigev_notify != SIGEV_SIGNAL &&
1072 notification.sigev_notify != SIGEV_THREAD))
1073 return -EINVAL;
1074 if (notification.sigev_notify == SIGEV_SIGNAL &&
Jesper Juhl7ed20e12005-05-01 08:59:14 -07001075 !valid_signal(notification.sigev_signo)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001076 return -EINVAL;
1077 }
1078 if (notification.sigev_notify == SIGEV_THREAD) {
Patrick McHardyc3d8d1e2007-11-07 02:42:09 -08001079 long timeo;
1080
Linus Torvalds1da177e2005-04-16 15:20:36 -07001081 /* create the notify skb */
1082 nc = alloc_skb(NOTIFY_COOKIE_LEN, GFP_KERNEL);
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -03001083 if (!nc) {
1084 ret = -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001085 goto out;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -03001086 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001087 if (copy_from_user(nc->data,
1088 notification.sigev_value.sival_ptr,
1089 NOTIFY_COOKIE_LEN)) {
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -03001090 ret = -EFAULT;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001091 goto out;
1092 }
1093
1094 /* TODO: add a header? */
1095 skb_put(nc, NOTIFY_COOKIE_LEN);
1096 /* and attach it to the socket */
1097retry:
1098 filp = fget(notification.sigev_signo);
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -03001099 if (!filp) {
1100 ret = -EBADF;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001101 goto out;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -03001102 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001103 sock = netlink_getsockbyfilp(filp);
1104 fput(filp);
1105 if (IS_ERR(sock)) {
1106 ret = PTR_ERR(sock);
1107 sock = NULL;
1108 goto out;
1109 }
1110
Patrick McHardyc3d8d1e2007-11-07 02:42:09 -08001111 timeo = MAX_SCHEDULE_TIMEOUT;
Denis V. Lunev9457afe2008-06-05 11:23:39 -07001112 ret = netlink_attachskb(sock, nc, &timeo, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001113 if (ret == 1)
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -03001114 goto retry;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001115 if (ret) {
1116 sock = NULL;
1117 nc = NULL;
1118 goto out;
1119 }
1120 }
1121 }
1122
Linus Torvalds1da177e2005-04-16 15:20:36 -07001123 filp = fget(mqdes);
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -03001124 if (!filp) {
1125 ret = -EBADF;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001126 goto out;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -03001127 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001128
Josef Sipek6d630792006-12-08 02:37:11 -08001129 inode = filp->f_path.dentry->d_inode;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -03001130 if (unlikely(filp->f_op != &mqueue_file_operations)) {
1131 ret = -EBADF;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001132 goto out_fput;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -03001133 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001134 info = MQUEUE_I(inode);
1135
1136 ret = 0;
1137 spin_lock(&info->lock);
1138 if (u_notification == NULL) {
Cedric Le Goatera03fcb72006-10-02 02:17:26 -07001139 if (info->notify_owner == task_tgid(current)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001140 remove_notification(info);
1141 inode->i_atime = inode->i_ctime = CURRENT_TIME;
1142 }
Cedric Le Goatera03fcb72006-10-02 02:17:26 -07001143 } else if (info->notify_owner != NULL) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001144 ret = -EBUSY;
1145 } else {
1146 switch (notification.sigev_notify) {
1147 case SIGEV_NONE:
1148 info->notify.sigev_notify = SIGEV_NONE;
1149 break;
1150 case SIGEV_THREAD:
1151 info->notify_sock = sock;
1152 info->notify_cookie = nc;
1153 sock = NULL;
1154 nc = NULL;
1155 info->notify.sigev_notify = SIGEV_THREAD;
1156 break;
1157 case SIGEV_SIGNAL:
1158 info->notify.sigev_signo = notification.sigev_signo;
1159 info->notify.sigev_value = notification.sigev_value;
1160 info->notify.sigev_notify = SIGEV_SIGNAL;
1161 break;
1162 }
Cedric Le Goatera03fcb72006-10-02 02:17:26 -07001163
1164 info->notify_owner = get_pid(task_tgid(current));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001165 inode->i_atime = inode->i_ctime = CURRENT_TIME;
1166 }
1167 spin_unlock(&info->lock);
1168out_fput:
1169 fput(filp);
1170out:
1171 if (sock) {
1172 netlink_detachskb(sock, nc);
1173 } else if (nc) {
1174 dev_kfree_skb(nc);
1175 }
1176 return ret;
1177}
1178
Heiko Carstensc4ea37c2009-01-14 14:14:28 +01001179SYSCALL_DEFINE3(mq_getsetattr, mqd_t, mqdes,
1180 const struct mq_attr __user *, u_mqstat,
1181 struct mq_attr __user *, u_omqstat)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001182{
1183 int ret;
1184 struct mq_attr mqstat, omqstat;
1185 struct file *filp;
1186 struct inode *inode;
1187 struct mqueue_inode_info *info;
1188
1189 if (u_mqstat != NULL) {
1190 if (copy_from_user(&mqstat, u_mqstat, sizeof(struct mq_attr)))
1191 return -EFAULT;
1192 if (mqstat.mq_flags & (~O_NONBLOCK))
1193 return -EINVAL;
1194 }
1195
Linus Torvalds1da177e2005-04-16 15:20:36 -07001196 filp = fget(mqdes);
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -03001197 if (!filp) {
1198 ret = -EBADF;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001199 goto out;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -03001200 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001201
Josef Sipek6d630792006-12-08 02:37:11 -08001202 inode = filp->f_path.dentry->d_inode;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -03001203 if (unlikely(filp->f_op != &mqueue_file_operations)) {
1204 ret = -EBADF;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001205 goto out_fput;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -03001206 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001207 info = MQUEUE_I(inode);
1208
1209 spin_lock(&info->lock);
1210
1211 omqstat = info->attr;
1212 omqstat.mq_flags = filp->f_flags & O_NONBLOCK;
1213 if (u_mqstat) {
Al Viro73929062008-12-10 06:58:59 -05001214 audit_mq_getsetattr(mqdes, &mqstat);
Jonathan Corbetdb1dd4d2009-02-06 15:25:24 -07001215 spin_lock(&filp->f_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001216 if (mqstat.mq_flags & O_NONBLOCK)
1217 filp->f_flags |= O_NONBLOCK;
1218 else
1219 filp->f_flags &= ~O_NONBLOCK;
Jonathan Corbetdb1dd4d2009-02-06 15:25:24 -07001220 spin_unlock(&filp->f_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001221
1222 inode->i_atime = inode->i_ctime = CURRENT_TIME;
1223 }
1224
1225 spin_unlock(&info->lock);
1226
1227 ret = 0;
1228 if (u_omqstat != NULL && copy_to_user(u_omqstat, &omqstat,
1229 sizeof(struct mq_attr)))
1230 ret = -EFAULT;
1231
1232out_fput:
1233 fput(filp);
1234out:
1235 return ret;
1236}
1237
Arjan van de Ven92e1d5b2007-02-12 00:55:39 -08001238static const struct inode_operations mqueue_dir_inode_operations = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001239 .lookup = simple_lookup,
1240 .create = mqueue_create,
1241 .unlink = mqueue_unlink,
1242};
1243
Arjan van de Ven9a321442007-02-12 00:55:35 -08001244static const struct file_operations mqueue_file_operations = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001245 .flush = mqueue_flush_file,
1246 .poll = mqueue_poll_file,
1247 .read = mqueue_read_file,
1248};
1249
Alexey Dobriyanb87221d2009-09-21 17:01:09 -07001250static const struct super_operations mqueue_super_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001251 .alloc_inode = mqueue_alloc_inode,
1252 .destroy_inode = mqueue_destroy_inode,
1253 .statfs = simple_statfs,
1254 .delete_inode = mqueue_delete_inode,
1255 .drop_inode = generic_delete_inode,
1256};
1257
1258static struct file_system_type mqueue_fs_type = {
1259 .name = "mqueue",
1260 .get_sb = mqueue_get_sb,
1261 .kill_sb = kill_litter_super,
1262};
1263
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -07001264int mq_init_ns(struct ipc_namespace *ns)
1265{
1266 ns->mq_queues_count = 0;
1267 ns->mq_queues_max = DFLT_QUEUESMAX;
1268 ns->mq_msg_max = DFLT_MSGMAX;
1269 ns->mq_msgsize_max = DFLT_MSGSIZEMAX;
1270
1271 ns->mq_mnt = kern_mount_data(&mqueue_fs_type, ns);
1272 if (IS_ERR(ns->mq_mnt)) {
1273 int err = PTR_ERR(ns->mq_mnt);
1274 ns->mq_mnt = NULL;
1275 return err;
1276 }
1277 return 0;
1278}
1279
1280void mq_clear_sbinfo(struct ipc_namespace *ns)
1281{
1282 ns->mq_mnt->mnt_sb->s_fs_info = NULL;
1283}
1284
1285void mq_put_mnt(struct ipc_namespace *ns)
1286{
1287 mntput(ns->mq_mnt);
1288}
1289
Linus Torvalds1da177e2005-04-16 15:20:36 -07001290static int __init init_mqueue_fs(void)
1291{
1292 int error;
1293
1294 mqueue_inode_cachep = kmem_cache_create("mqueue_inode_cache",
1295 sizeof(struct mqueue_inode_info), 0,
Paul Mundt20c2df82007-07-20 10:11:58 +09001296 SLAB_HWCACHE_ALIGN, init_once);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001297 if (mqueue_inode_cachep == NULL)
1298 return -ENOMEM;
1299
André Goddard Rosa2329e392010-02-23 04:04:27 -03001300 /* ignore failures - they are not fatal */
Serge E. Hallynbdc8e5f2009-04-06 19:01:11 -07001301 mq_sysctl_table = mq_register_sysctl_table();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001302
1303 error = register_filesystem(&mqueue_fs_type);
1304 if (error)
1305 goto out_sysctl;
1306
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -07001307 spin_lock_init(&mq_lock);
1308
1309 init_ipc_ns.mq_mnt = kern_mount_data(&mqueue_fs_type, &init_ipc_ns);
Serge E. Hallyn614b84c2009-04-06 19:01:08 -07001310 if (IS_ERR(init_ipc_ns.mq_mnt)) {
1311 error = PTR_ERR(init_ipc_ns.mq_mnt);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001312 goto out_filesystem;
1313 }
1314
Linus Torvalds1da177e2005-04-16 15:20:36 -07001315 return 0;
1316
1317out_filesystem:
1318 unregister_filesystem(&mqueue_fs_type);
1319out_sysctl:
1320 if (mq_sysctl_table)
1321 unregister_sysctl_table(mq_sysctl_table);
Alexey Dobriyan1a1d92c2006-09-27 01:49:40 -07001322 kmem_cache_destroy(mqueue_inode_cachep);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001323 return error;
1324}
1325
1326__initcall(init_mqueue_fs);