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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * linux/ipc/msg.c | |
5a06a363 | 3 | * Copyright (C) 1992 Krishna Balasubramanian |
1da177e4 LT |
4 | * |
5 | * Removed all the remaining kerneld mess | |
6 | * Catch the -EFAULT stuff properly | |
7 | * Use GFP_KERNEL for messages as in 1.2 | |
8 | * Fixed up the unchecked user space derefs | |
9 | * Copyright (C) 1998 Alan Cox & Andi Kleen | |
10 | * | |
11 | * /proc/sysvipc/msg support (c) 1999 Dragos Acostachioaie <dragos@iname.com> | |
12 | * | |
13 | * mostly rewritten, threaded and wake-one semantics added | |
14 | * MSGMAX limit removed, sysctl's added | |
624dffcb | 15 | * (c) 1999 Manfred Spraul <manfred@colorfullife.com> |
073115d6 SG |
16 | * |
17 | * support for audit of ipc object properties and permission changes | |
18 | * Dustin Kirkland <dustin.kirkland@us.ibm.com> | |
1e786937 KK |
19 | * |
20 | * namespaces support | |
21 | * OpenVZ, SWsoft Inc. | |
22 | * Pavel Emelianov <xemul@openvz.org> | |
1da177e4 LT |
23 | */ |
24 | ||
c59ede7b | 25 | #include <linux/capability.h> |
1da177e4 LT |
26 | #include <linux/slab.h> |
27 | #include <linux/msg.h> | |
28 | #include <linux/spinlock.h> | |
29 | #include <linux/init.h> | |
30 | #include <linux/proc_fs.h> | |
31 | #include <linux/list.h> | |
32 | #include <linux/security.h> | |
33 | #include <linux/sched.h> | |
34 | #include <linux/syscalls.h> | |
35 | #include <linux/audit.h> | |
19b4946c | 36 | #include <linux/seq_file.h> |
3e148c79 | 37 | #include <linux/rwsem.h> |
1e786937 | 38 | #include <linux/nsproxy.h> |
ae5e1b22 | 39 | #include <linux/ipc_namespace.h> |
5f921ae9 | 40 | |
1da177e4 LT |
41 | #include <asm/current.h> |
42 | #include <asm/uaccess.h> | |
43 | #include "util.h" | |
44 | ||
5a06a363 IM |
45 | /* |
46 | * one msg_receiver structure for each sleeping receiver: | |
47 | */ | |
1da177e4 | 48 | struct msg_receiver { |
5a06a363 IM |
49 | struct list_head r_list; |
50 | struct task_struct *r_tsk; | |
1da177e4 | 51 | |
5a06a363 IM |
52 | int r_mode; |
53 | long r_msgtype; | |
54 | long r_maxsize; | |
1da177e4 | 55 | |
80491eb9 | 56 | struct msg_msg *volatile r_msg; |
1da177e4 LT |
57 | }; |
58 | ||
59 | /* one msg_sender for each sleeping sender */ | |
60 | struct msg_sender { | |
5a06a363 IM |
61 | struct list_head list; |
62 | struct task_struct *tsk; | |
1da177e4 LT |
63 | }; |
64 | ||
65 | #define SEARCH_ANY 1 | |
66 | #define SEARCH_EQUAL 2 | |
67 | #define SEARCH_NOTEQUAL 3 | |
68 | #define SEARCH_LESSEQUAL 4 | |
69 | ||
ed2ddbf8 | 70 | #define msg_ids(ns) ((ns)->ids[IPC_MSG_IDS]) |
1da177e4 | 71 | |
1e786937 | 72 | #define msg_unlock(msq) ipc_unlock(&(msq)->q_perm) |
1b531f21 | 73 | #define msg_buildid(id, seq) ipc_buildid(id, seq) |
1e786937 | 74 | |
7ca7e564 | 75 | static void freeque(struct ipc_namespace *, struct msg_queue *); |
7748dbfa | 76 | static int newque(struct ipc_namespace *, struct ipc_params *); |
1da177e4 | 77 | #ifdef CONFIG_PROC_FS |
19b4946c | 78 | static int sysvipc_msg_proc_show(struct seq_file *s, void *it); |
1da177e4 LT |
79 | #endif |
80 | ||
ed2ddbf8 | 81 | void msg_init_ns(struct ipc_namespace *ns) |
1e786937 | 82 | { |
1e786937 KK |
83 | ns->msg_ctlmax = MSGMAX; |
84 | ns->msg_ctlmnb = MSGMNB; | |
85 | ns->msg_ctlmni = MSGMNI; | |
3ac88a41 KK |
86 | atomic_set(&ns->msg_bytes, 0); |
87 | atomic_set(&ns->msg_hdrs, 0); | |
ed2ddbf8 | 88 | ipc_init_ids(&ns->ids[IPC_MSG_IDS]); |
1e786937 KK |
89 | } |
90 | ||
ae5e1b22 | 91 | #ifdef CONFIG_IPC_NS |
1e786937 KK |
92 | void msg_exit_ns(struct ipc_namespace *ns) |
93 | { | |
1e786937 | 94 | struct msg_queue *msq; |
b1ed88b4 | 95 | struct kern_ipc_perm *perm; |
7ca7e564 ND |
96 | int next_id; |
97 | int total, in_use; | |
1e786937 | 98 | |
3e148c79 | 99 | down_write(&msg_ids(ns).rw_mutex); |
7ca7e564 ND |
100 | |
101 | in_use = msg_ids(ns).in_use; | |
102 | ||
103 | for (total = 0, next_id = 0; total < in_use; next_id++) { | |
b1ed88b4 PP |
104 | perm = idr_find(&msg_ids(ns).ipcs_idr, next_id); |
105 | if (perm == NULL) | |
1e786937 | 106 | continue; |
b1ed88b4 PP |
107 | ipc_lock_by_ptr(perm); |
108 | msq = container_of(perm, struct msg_queue, q_perm); | |
7ca7e564 ND |
109 | freeque(ns, msq); |
110 | total++; | |
1e786937 | 111 | } |
3e148c79 ND |
112 | |
113 | up_write(&msg_ids(ns).rw_mutex); | |
1e786937 | 114 | } |
ae5e1b22 | 115 | #endif |
1e786937 | 116 | |
5a06a363 | 117 | void __init msg_init(void) |
1da177e4 | 118 | { |
ed2ddbf8 | 119 | msg_init_ns(&init_ipc_ns); |
19b4946c MW |
120 | ipc_init_proc_interface("sysvipc/msg", |
121 | " key msqid perms cbytes qnum lspid lrpid uid gid cuid cgid stime rtime ctime\n", | |
1e786937 | 122 | IPC_MSG_IDS, sysvipc_msg_proc_show); |
1da177e4 LT |
123 | } |
124 | ||
3e148c79 ND |
125 | /* |
126 | * This routine is called in the paths where the rw_mutex is held to protect | |
127 | * access to the idr tree. | |
128 | */ | |
129 | static inline struct msg_queue *msg_lock_check_down(struct ipc_namespace *ns, | |
130 | int id) | |
131 | { | |
132 | struct kern_ipc_perm *ipcp = ipc_lock_check_down(&msg_ids(ns), id); | |
133 | ||
b1ed88b4 PP |
134 | if (IS_ERR(ipcp)) |
135 | return (struct msg_queue *)ipcp; | |
136 | ||
3e148c79 ND |
137 | return container_of(ipcp, struct msg_queue, q_perm); |
138 | } | |
139 | ||
140 | /* | |
141 | * msg_lock_(check_) routines are called in the paths where the rw_mutex | |
142 | * is not held. | |
143 | */ | |
023a5355 ND |
144 | static inline struct msg_queue *msg_lock(struct ipc_namespace *ns, int id) |
145 | { | |
03f02c76 ND |
146 | struct kern_ipc_perm *ipcp = ipc_lock(&msg_ids(ns), id); |
147 | ||
b1ed88b4 PP |
148 | if (IS_ERR(ipcp)) |
149 | return (struct msg_queue *)ipcp; | |
150 | ||
03f02c76 | 151 | return container_of(ipcp, struct msg_queue, q_perm); |
023a5355 ND |
152 | } |
153 | ||
154 | static inline struct msg_queue *msg_lock_check(struct ipc_namespace *ns, | |
155 | int id) | |
156 | { | |
03f02c76 ND |
157 | struct kern_ipc_perm *ipcp = ipc_lock_check(&msg_ids(ns), id); |
158 | ||
b1ed88b4 PP |
159 | if (IS_ERR(ipcp)) |
160 | return (struct msg_queue *)ipcp; | |
161 | ||
03f02c76 | 162 | return container_of(ipcp, struct msg_queue, q_perm); |
023a5355 ND |
163 | } |
164 | ||
7ca7e564 ND |
165 | static inline void msg_rmid(struct ipc_namespace *ns, struct msg_queue *s) |
166 | { | |
167 | ipc_rmid(&msg_ids(ns), &s->q_perm); | |
168 | } | |
169 | ||
f4566f04 ND |
170 | /** |
171 | * newque - Create a new msg queue | |
172 | * @ns: namespace | |
173 | * @params: ptr to the structure that contains the key and msgflg | |
174 | * | |
3e148c79 | 175 | * Called with msg_ids.rw_mutex held (writer) |
f4566f04 | 176 | */ |
7748dbfa | 177 | static int newque(struct ipc_namespace *ns, struct ipc_params *params) |
1da177e4 | 178 | { |
1da177e4 | 179 | struct msg_queue *msq; |
5a06a363 | 180 | int id, retval; |
7748dbfa ND |
181 | key_t key = params->key; |
182 | int msgflg = params->flg; | |
1da177e4 | 183 | |
5a06a363 IM |
184 | msq = ipc_rcu_alloc(sizeof(*msq)); |
185 | if (!msq) | |
1da177e4 LT |
186 | return -ENOMEM; |
187 | ||
5a06a363 | 188 | msq->q_perm.mode = msgflg & S_IRWXUGO; |
1da177e4 LT |
189 | msq->q_perm.key = key; |
190 | ||
191 | msq->q_perm.security = NULL; | |
192 | retval = security_msg_queue_alloc(msq); | |
193 | if (retval) { | |
194 | ipc_rcu_putref(msq); | |
195 | return retval; | |
196 | } | |
197 | ||
7ca7e564 ND |
198 | /* |
199 | * ipc_addid() locks msq | |
200 | */ | |
1e786937 | 201 | id = ipc_addid(&msg_ids(ns), &msq->q_perm, ns->msg_ctlmni); |
283bb7fa | 202 | if (id < 0) { |
1da177e4 LT |
203 | security_msg_queue_free(msq); |
204 | ipc_rcu_putref(msq); | |
283bb7fa | 205 | return id; |
1da177e4 LT |
206 | } |
207 | ||
1b531f21 | 208 | msq->q_perm.id = msg_buildid(id, msq->q_perm.seq); |
1da177e4 LT |
209 | msq->q_stime = msq->q_rtime = 0; |
210 | msq->q_ctime = get_seconds(); | |
211 | msq->q_cbytes = msq->q_qnum = 0; | |
1e786937 | 212 | msq->q_qbytes = ns->msg_ctlmnb; |
1da177e4 LT |
213 | msq->q_lspid = msq->q_lrpid = 0; |
214 | INIT_LIST_HEAD(&msq->q_messages); | |
215 | INIT_LIST_HEAD(&msq->q_receivers); | |
216 | INIT_LIST_HEAD(&msq->q_senders); | |
7ca7e564 | 217 | |
1da177e4 LT |
218 | msg_unlock(msq); |
219 | ||
7ca7e564 | 220 | return msq->q_perm.id; |
1da177e4 LT |
221 | } |
222 | ||
5a06a363 | 223 | static inline void ss_add(struct msg_queue *msq, struct msg_sender *mss) |
1da177e4 | 224 | { |
5a06a363 IM |
225 | mss->tsk = current; |
226 | current->state = TASK_INTERRUPTIBLE; | |
227 | list_add_tail(&mss->list, &msq->q_senders); | |
1da177e4 LT |
228 | } |
229 | ||
5a06a363 | 230 | static inline void ss_del(struct msg_sender *mss) |
1da177e4 | 231 | { |
5a06a363 | 232 | if (mss->list.next != NULL) |
1da177e4 LT |
233 | list_del(&mss->list); |
234 | } | |
235 | ||
5a06a363 | 236 | static void ss_wakeup(struct list_head *h, int kill) |
1da177e4 LT |
237 | { |
238 | struct list_head *tmp; | |
239 | ||
240 | tmp = h->next; | |
241 | while (tmp != h) { | |
5a06a363 IM |
242 | struct msg_sender *mss; |
243 | ||
244 | mss = list_entry(tmp, struct msg_sender, list); | |
1da177e4 | 245 | tmp = tmp->next; |
5a06a363 IM |
246 | if (kill) |
247 | mss->list.next = NULL; | |
1da177e4 LT |
248 | wake_up_process(mss->tsk); |
249 | } | |
250 | } | |
251 | ||
5a06a363 | 252 | static void expunge_all(struct msg_queue *msq, int res) |
1da177e4 LT |
253 | { |
254 | struct list_head *tmp; | |
255 | ||
256 | tmp = msq->q_receivers.next; | |
257 | while (tmp != &msq->q_receivers) { | |
5a06a363 IM |
258 | struct msg_receiver *msr; |
259 | ||
260 | msr = list_entry(tmp, struct msg_receiver, r_list); | |
1da177e4 LT |
261 | tmp = tmp->next; |
262 | msr->r_msg = NULL; | |
263 | wake_up_process(msr->r_tsk); | |
264 | smp_mb(); | |
265 | msr->r_msg = ERR_PTR(res); | |
266 | } | |
267 | } | |
5a06a363 IM |
268 | |
269 | /* | |
270 | * freeque() wakes up waiters on the sender and receiver waiting queue, | |
f4566f04 ND |
271 | * removes the message queue from message queue ID IDR, and cleans up all the |
272 | * messages associated with this queue. | |
1da177e4 | 273 | * |
3e148c79 ND |
274 | * msg_ids.rw_mutex (writer) and the spinlock for this message queue are held |
275 | * before freeque() is called. msg_ids.rw_mutex remains locked on exit. | |
1da177e4 | 276 | */ |
7ca7e564 | 277 | static void freeque(struct ipc_namespace *ns, struct msg_queue *msq) |
1da177e4 LT |
278 | { |
279 | struct list_head *tmp; | |
280 | ||
5a06a363 IM |
281 | expunge_all(msq, -EIDRM); |
282 | ss_wakeup(&msq->q_senders, 1); | |
7ca7e564 | 283 | msg_rmid(ns, msq); |
1da177e4 | 284 | msg_unlock(msq); |
5a06a363 | 285 | |
1da177e4 | 286 | tmp = msq->q_messages.next; |
5a06a363 IM |
287 | while (tmp != &msq->q_messages) { |
288 | struct msg_msg *msg = list_entry(tmp, struct msg_msg, m_list); | |
289 | ||
1da177e4 | 290 | tmp = tmp->next; |
3ac88a41 | 291 | atomic_dec(&ns->msg_hdrs); |
1da177e4 LT |
292 | free_msg(msg); |
293 | } | |
3ac88a41 | 294 | atomic_sub(msq->q_cbytes, &ns->msg_bytes); |
1da177e4 LT |
295 | security_msg_queue_free(msq); |
296 | ipc_rcu_putref(msq); | |
297 | } | |
298 | ||
f4566f04 | 299 | /* |
3e148c79 | 300 | * Called with msg_ids.rw_mutex and ipcp locked. |
f4566f04 | 301 | */ |
03f02c76 | 302 | static inline int msg_security(struct kern_ipc_perm *ipcp, int msgflg) |
7748dbfa | 303 | { |
03f02c76 ND |
304 | struct msg_queue *msq = container_of(ipcp, struct msg_queue, q_perm); |
305 | ||
306 | return security_msg_queue_associate(msq, msgflg); | |
7748dbfa ND |
307 | } |
308 | ||
5a06a363 | 309 | asmlinkage long sys_msgget(key_t key, int msgflg) |
1da177e4 | 310 | { |
1e786937 | 311 | struct ipc_namespace *ns; |
7748dbfa ND |
312 | struct ipc_ops msg_ops; |
313 | struct ipc_params msg_params; | |
1e786937 KK |
314 | |
315 | ns = current->nsproxy->ipc_ns; | |
7ca7e564 | 316 | |
7748dbfa ND |
317 | msg_ops.getnew = newque; |
318 | msg_ops.associate = msg_security; | |
319 | msg_ops.more_checks = NULL; | |
320 | ||
321 | msg_params.key = key; | |
322 | msg_params.flg = msgflg; | |
5a06a363 | 323 | |
7748dbfa | 324 | return ipcget(ns, &msg_ids(ns), &msg_ops, &msg_params); |
1da177e4 LT |
325 | } |
326 | ||
5a06a363 IM |
327 | static inline unsigned long |
328 | copy_msqid_to_user(void __user *buf, struct msqid64_ds *in, int version) | |
1da177e4 LT |
329 | { |
330 | switch(version) { | |
331 | case IPC_64: | |
5a06a363 | 332 | return copy_to_user(buf, in, sizeof(*in)); |
1da177e4 | 333 | case IPC_OLD: |
5a06a363 | 334 | { |
1da177e4 LT |
335 | struct msqid_ds out; |
336 | ||
5a06a363 | 337 | memset(&out, 0, sizeof(out)); |
1da177e4 LT |
338 | |
339 | ipc64_perm_to_ipc_perm(&in->msg_perm, &out.msg_perm); | |
340 | ||
341 | out.msg_stime = in->msg_stime; | |
342 | out.msg_rtime = in->msg_rtime; | |
343 | out.msg_ctime = in->msg_ctime; | |
344 | ||
5a06a363 | 345 | if (in->msg_cbytes > USHRT_MAX) |
1da177e4 LT |
346 | out.msg_cbytes = USHRT_MAX; |
347 | else | |
348 | out.msg_cbytes = in->msg_cbytes; | |
349 | out.msg_lcbytes = in->msg_cbytes; | |
350 | ||
5a06a363 | 351 | if (in->msg_qnum > USHRT_MAX) |
1da177e4 LT |
352 | out.msg_qnum = USHRT_MAX; |
353 | else | |
354 | out.msg_qnum = in->msg_qnum; | |
355 | ||
5a06a363 | 356 | if (in->msg_qbytes > USHRT_MAX) |
1da177e4 LT |
357 | out.msg_qbytes = USHRT_MAX; |
358 | else | |
359 | out.msg_qbytes = in->msg_qbytes; | |
360 | out.msg_lqbytes = in->msg_qbytes; | |
361 | ||
362 | out.msg_lspid = in->msg_lspid; | |
363 | out.msg_lrpid = in->msg_lrpid; | |
364 | ||
5a06a363 IM |
365 | return copy_to_user(buf, &out, sizeof(out)); |
366 | } | |
1da177e4 LT |
367 | default: |
368 | return -EINVAL; | |
369 | } | |
370 | } | |
371 | ||
372 | struct msq_setbuf { | |
373 | unsigned long qbytes; | |
374 | uid_t uid; | |
375 | gid_t gid; | |
376 | mode_t mode; | |
377 | }; | |
378 | ||
5a06a363 IM |
379 | static inline unsigned long |
380 | copy_msqid_from_user(struct msq_setbuf *out, void __user *buf, int version) | |
1da177e4 LT |
381 | { |
382 | switch(version) { | |
383 | case IPC_64: | |
5a06a363 | 384 | { |
1da177e4 LT |
385 | struct msqid64_ds tbuf; |
386 | ||
5a06a363 | 387 | if (copy_from_user(&tbuf, buf, sizeof(tbuf))) |
1da177e4 LT |
388 | return -EFAULT; |
389 | ||
390 | out->qbytes = tbuf.msg_qbytes; | |
391 | out->uid = tbuf.msg_perm.uid; | |
392 | out->gid = tbuf.msg_perm.gid; | |
393 | out->mode = tbuf.msg_perm.mode; | |
394 | ||
395 | return 0; | |
5a06a363 | 396 | } |
1da177e4 | 397 | case IPC_OLD: |
5a06a363 | 398 | { |
1da177e4 LT |
399 | struct msqid_ds tbuf_old; |
400 | ||
5a06a363 | 401 | if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old))) |
1da177e4 LT |
402 | return -EFAULT; |
403 | ||
404 | out->uid = tbuf_old.msg_perm.uid; | |
405 | out->gid = tbuf_old.msg_perm.gid; | |
406 | out->mode = tbuf_old.msg_perm.mode; | |
407 | ||
5a06a363 | 408 | if (tbuf_old.msg_qbytes == 0) |
1da177e4 LT |
409 | out->qbytes = tbuf_old.msg_lqbytes; |
410 | else | |
411 | out->qbytes = tbuf_old.msg_qbytes; | |
412 | ||
413 | return 0; | |
5a06a363 | 414 | } |
1da177e4 LT |
415 | default: |
416 | return -EINVAL; | |
417 | } | |
418 | } | |
419 | ||
5a06a363 | 420 | asmlinkage long sys_msgctl(int msqid, int cmd, struct msqid_ds __user *buf) |
1da177e4 | 421 | { |
1da177e4 | 422 | struct kern_ipc_perm *ipcp; |
8e1c091c | 423 | struct msq_setbuf uninitialized_var(setbuf); |
5a06a363 IM |
424 | struct msg_queue *msq; |
425 | int err, version; | |
1e786937 | 426 | struct ipc_namespace *ns; |
5a06a363 | 427 | |
1da177e4 LT |
428 | if (msqid < 0 || cmd < 0) |
429 | return -EINVAL; | |
430 | ||
431 | version = ipc_parse_version(&cmd); | |
1e786937 | 432 | ns = current->nsproxy->ipc_ns; |
1da177e4 LT |
433 | |
434 | switch (cmd) { | |
5a06a363 IM |
435 | case IPC_INFO: |
436 | case MSG_INFO: | |
437 | { | |
1da177e4 LT |
438 | struct msginfo msginfo; |
439 | int max_id; | |
5a06a363 | 440 | |
1da177e4 LT |
441 | if (!buf) |
442 | return -EFAULT; | |
5a06a363 IM |
443 | /* |
444 | * We must not return kernel stack data. | |
1da177e4 LT |
445 | * due to padding, it's not enough |
446 | * to set all member fields. | |
447 | */ | |
1da177e4 LT |
448 | err = security_msg_queue_msgctl(NULL, cmd); |
449 | if (err) | |
450 | return err; | |
451 | ||
5a06a363 | 452 | memset(&msginfo, 0, sizeof(msginfo)); |
1e786937 KK |
453 | msginfo.msgmni = ns->msg_ctlmni; |
454 | msginfo.msgmax = ns->msg_ctlmax; | |
455 | msginfo.msgmnb = ns->msg_ctlmnb; | |
1da177e4 LT |
456 | msginfo.msgssz = MSGSSZ; |
457 | msginfo.msgseg = MSGSEG; | |
3e148c79 | 458 | down_read(&msg_ids(ns).rw_mutex); |
1da177e4 | 459 | if (cmd == MSG_INFO) { |
1e786937 | 460 | msginfo.msgpool = msg_ids(ns).in_use; |
3ac88a41 KK |
461 | msginfo.msgmap = atomic_read(&ns->msg_hdrs); |
462 | msginfo.msgtql = atomic_read(&ns->msg_bytes); | |
1da177e4 LT |
463 | } else { |
464 | msginfo.msgmap = MSGMAP; | |
465 | msginfo.msgpool = MSGPOOL; | |
466 | msginfo.msgtql = MSGTQL; | |
467 | } | |
7ca7e564 | 468 | max_id = ipc_get_maxid(&msg_ids(ns)); |
3e148c79 | 469 | up_read(&msg_ids(ns).rw_mutex); |
5a06a363 | 470 | if (copy_to_user(buf, &msginfo, sizeof(struct msginfo))) |
1da177e4 | 471 | return -EFAULT; |
5a06a363 | 472 | return (max_id < 0) ? 0 : max_id; |
1da177e4 | 473 | } |
7ca7e564 | 474 | case MSG_STAT: /* msqid is an index rather than a msg queue id */ |
1da177e4 LT |
475 | case IPC_STAT: |
476 | { | |
477 | struct msqid64_ds tbuf; | |
478 | int success_return; | |
5a06a363 | 479 | |
1da177e4 LT |
480 | if (!buf) |
481 | return -EFAULT; | |
1da177e4 | 482 | |
5a06a363 | 483 | if (cmd == MSG_STAT) { |
023a5355 ND |
484 | msq = msg_lock(ns, msqid); |
485 | if (IS_ERR(msq)) | |
486 | return PTR_ERR(msq); | |
7ca7e564 | 487 | success_return = msq->q_perm.id; |
1da177e4 | 488 | } else { |
023a5355 ND |
489 | msq = msg_lock_check(ns, msqid); |
490 | if (IS_ERR(msq)) | |
491 | return PTR_ERR(msq); | |
1da177e4 LT |
492 | success_return = 0; |
493 | } | |
494 | err = -EACCES; | |
5a06a363 | 495 | if (ipcperms(&msq->q_perm, S_IRUGO)) |
1da177e4 LT |
496 | goto out_unlock; |
497 | ||
498 | err = security_msg_queue_msgctl(msq, cmd); | |
499 | if (err) | |
500 | goto out_unlock; | |
501 | ||
023a5355 ND |
502 | memset(&tbuf, 0, sizeof(tbuf)); |
503 | ||
1da177e4 LT |
504 | kernel_to_ipc64_perm(&msq->q_perm, &tbuf.msg_perm); |
505 | tbuf.msg_stime = msq->q_stime; | |
506 | tbuf.msg_rtime = msq->q_rtime; | |
507 | tbuf.msg_ctime = msq->q_ctime; | |
508 | tbuf.msg_cbytes = msq->q_cbytes; | |
509 | tbuf.msg_qnum = msq->q_qnum; | |
510 | tbuf.msg_qbytes = msq->q_qbytes; | |
511 | tbuf.msg_lspid = msq->q_lspid; | |
512 | tbuf.msg_lrpid = msq->q_lrpid; | |
513 | msg_unlock(msq); | |
514 | if (copy_msqid_to_user(buf, &tbuf, version)) | |
515 | return -EFAULT; | |
516 | return success_return; | |
517 | } | |
518 | case IPC_SET: | |
519 | if (!buf) | |
520 | return -EFAULT; | |
5a06a363 | 521 | if (copy_msqid_from_user(&setbuf, buf, version)) |
1da177e4 | 522 | return -EFAULT; |
1da177e4 LT |
523 | break; |
524 | case IPC_RMID: | |
525 | break; | |
526 | default: | |
527 | return -EINVAL; | |
528 | } | |
529 | ||
3e148c79 ND |
530 | down_write(&msg_ids(ns).rw_mutex); |
531 | msq = msg_lock_check_down(ns, msqid); | |
023a5355 ND |
532 | if (IS_ERR(msq)) { |
533 | err = PTR_ERR(msq); | |
1da177e4 | 534 | goto out_up; |
023a5355 | 535 | } |
1da177e4 | 536 | |
1da177e4 | 537 | ipcp = &msq->q_perm; |
073115d6 SG |
538 | |
539 | err = audit_ipc_obj(ipcp); | |
540 | if (err) | |
541 | goto out_unlock_up; | |
8e1c091c | 542 | if (cmd == IPC_SET) { |
5a06a363 IM |
543 | err = audit_ipc_set_perm(setbuf.qbytes, setbuf.uid, setbuf.gid, |
544 | setbuf.mode); | |
ac03221a LK |
545 | if (err) |
546 | goto out_unlock_up; | |
547 | } | |
073115d6 | 548 | |
1da177e4 | 549 | err = -EPERM; |
5a06a363 | 550 | if (current->euid != ipcp->cuid && |
1da177e4 | 551 | current->euid != ipcp->uid && !capable(CAP_SYS_ADMIN)) |
5a06a363 | 552 | /* We _could_ check for CAP_CHOWN above, but we don't */ |
1da177e4 LT |
553 | goto out_unlock_up; |
554 | ||
555 | err = security_msg_queue_msgctl(msq, cmd); | |
556 | if (err) | |
557 | goto out_unlock_up; | |
558 | ||
559 | switch (cmd) { | |
560 | case IPC_SET: | |
561 | { | |
562 | err = -EPERM; | |
1e786937 | 563 | if (setbuf.qbytes > ns->msg_ctlmnb && !capable(CAP_SYS_RESOURCE)) |
1da177e4 LT |
564 | goto out_unlock_up; |
565 | ||
566 | msq->q_qbytes = setbuf.qbytes; | |
567 | ||
568 | ipcp->uid = setbuf.uid; | |
569 | ipcp->gid = setbuf.gid; | |
5a06a363 IM |
570 | ipcp->mode = (ipcp->mode & ~S_IRWXUGO) | |
571 | (S_IRWXUGO & setbuf.mode); | |
1da177e4 LT |
572 | msq->q_ctime = get_seconds(); |
573 | /* sleeping receivers might be excluded by | |
574 | * stricter permissions. | |
575 | */ | |
5a06a363 | 576 | expunge_all(msq, -EAGAIN); |
1da177e4 LT |
577 | /* sleeping senders might be able to send |
578 | * due to a larger queue size. | |
579 | */ | |
5a06a363 | 580 | ss_wakeup(&msq->q_senders, 0); |
1da177e4 LT |
581 | msg_unlock(msq); |
582 | break; | |
583 | } | |
584 | case IPC_RMID: | |
7ca7e564 | 585 | freeque(ns, msq); |
1da177e4 LT |
586 | break; |
587 | } | |
588 | err = 0; | |
589 | out_up: | |
3e148c79 | 590 | up_write(&msg_ids(ns).rw_mutex); |
1da177e4 LT |
591 | return err; |
592 | out_unlock_up: | |
593 | msg_unlock(msq); | |
594 | goto out_up; | |
595 | out_unlock: | |
596 | msg_unlock(msq); | |
597 | return err; | |
598 | } | |
599 | ||
5a06a363 | 600 | static int testmsg(struct msg_msg *msg, long type, int mode) |
1da177e4 LT |
601 | { |
602 | switch(mode) | |
603 | { | |
604 | case SEARCH_ANY: | |
605 | return 1; | |
606 | case SEARCH_LESSEQUAL: | |
5a06a363 | 607 | if (msg->m_type <=type) |
1da177e4 LT |
608 | return 1; |
609 | break; | |
610 | case SEARCH_EQUAL: | |
5a06a363 | 611 | if (msg->m_type == type) |
1da177e4 LT |
612 | return 1; |
613 | break; | |
614 | case SEARCH_NOTEQUAL: | |
5a06a363 | 615 | if (msg->m_type != type) |
1da177e4 LT |
616 | return 1; |
617 | break; | |
618 | } | |
619 | return 0; | |
620 | } | |
621 | ||
5a06a363 | 622 | static inline int pipelined_send(struct msg_queue *msq, struct msg_msg *msg) |
1da177e4 | 623 | { |
5a06a363 | 624 | struct list_head *tmp; |
1da177e4 LT |
625 | |
626 | tmp = msq->q_receivers.next; | |
627 | while (tmp != &msq->q_receivers) { | |
5a06a363 IM |
628 | struct msg_receiver *msr; |
629 | ||
630 | msr = list_entry(tmp, struct msg_receiver, r_list); | |
1da177e4 | 631 | tmp = tmp->next; |
5a06a363 IM |
632 | if (testmsg(msg, msr->r_msgtype, msr->r_mode) && |
633 | !security_msg_queue_msgrcv(msq, msg, msr->r_tsk, | |
634 | msr->r_msgtype, msr->r_mode)) { | |
635 | ||
1da177e4 | 636 | list_del(&msr->r_list); |
5a06a363 | 637 | if (msr->r_maxsize < msg->m_ts) { |
1da177e4 LT |
638 | msr->r_msg = NULL; |
639 | wake_up_process(msr->r_tsk); | |
640 | smp_mb(); | |
641 | msr->r_msg = ERR_PTR(-E2BIG); | |
642 | } else { | |
643 | msr->r_msg = NULL; | |
b488893a | 644 | msq->q_lrpid = task_pid_vnr(msr->r_tsk); |
1da177e4 LT |
645 | msq->q_rtime = get_seconds(); |
646 | wake_up_process(msr->r_tsk); | |
647 | smp_mb(); | |
648 | msr->r_msg = msg; | |
5a06a363 | 649 | |
1da177e4 LT |
650 | return 1; |
651 | } | |
652 | } | |
653 | } | |
654 | return 0; | |
655 | } | |
656 | ||
651971cb | 657 | long do_msgsnd(int msqid, long mtype, void __user *mtext, |
658 | size_t msgsz, int msgflg) | |
1da177e4 LT |
659 | { |
660 | struct msg_queue *msq; | |
661 | struct msg_msg *msg; | |
1da177e4 | 662 | int err; |
1e786937 KK |
663 | struct ipc_namespace *ns; |
664 | ||
665 | ns = current->nsproxy->ipc_ns; | |
5a06a363 | 666 | |
1e786937 | 667 | if (msgsz > ns->msg_ctlmax || (long) msgsz < 0 || msqid < 0) |
1da177e4 | 668 | return -EINVAL; |
1da177e4 LT |
669 | if (mtype < 1) |
670 | return -EINVAL; | |
671 | ||
651971cb | 672 | msg = load_msg(mtext, msgsz); |
5a06a363 | 673 | if (IS_ERR(msg)) |
1da177e4 LT |
674 | return PTR_ERR(msg); |
675 | ||
676 | msg->m_type = mtype; | |
677 | msg->m_ts = msgsz; | |
678 | ||
023a5355 ND |
679 | msq = msg_lock_check(ns, msqid); |
680 | if (IS_ERR(msq)) { | |
681 | err = PTR_ERR(msq); | |
1da177e4 | 682 | goto out_free; |
023a5355 | 683 | } |
1da177e4 LT |
684 | |
685 | for (;;) { | |
686 | struct msg_sender s; | |
687 | ||
5a06a363 | 688 | err = -EACCES; |
1da177e4 LT |
689 | if (ipcperms(&msq->q_perm, S_IWUGO)) |
690 | goto out_unlock_free; | |
691 | ||
692 | err = security_msg_queue_msgsnd(msq, msg, msgflg); | |
693 | if (err) | |
694 | goto out_unlock_free; | |
695 | ||
5a06a363 | 696 | if (msgsz + msq->q_cbytes <= msq->q_qbytes && |
1da177e4 LT |
697 | 1 + msq->q_qnum <= msq->q_qbytes) { |
698 | break; | |
699 | } | |
700 | ||
701 | /* queue full, wait: */ | |
5a06a363 IM |
702 | if (msgflg & IPC_NOWAIT) { |
703 | err = -EAGAIN; | |
1da177e4 LT |
704 | goto out_unlock_free; |
705 | } | |
706 | ss_add(msq, &s); | |
707 | ipc_rcu_getref(msq); | |
708 | msg_unlock(msq); | |
709 | schedule(); | |
710 | ||
711 | ipc_lock_by_ptr(&msq->q_perm); | |
712 | ipc_rcu_putref(msq); | |
713 | if (msq->q_perm.deleted) { | |
714 | err = -EIDRM; | |
715 | goto out_unlock_free; | |
716 | } | |
717 | ss_del(&s); | |
5a06a363 | 718 | |
1da177e4 | 719 | if (signal_pending(current)) { |
5a06a363 | 720 | err = -ERESTARTNOHAND; |
1da177e4 LT |
721 | goto out_unlock_free; |
722 | } | |
723 | } | |
724 | ||
b488893a | 725 | msq->q_lspid = task_tgid_vnr(current); |
1da177e4 LT |
726 | msq->q_stime = get_seconds(); |
727 | ||
5a06a363 | 728 | if (!pipelined_send(msq, msg)) { |
1da177e4 | 729 | /* noone is waiting for this message, enqueue it */ |
5a06a363 | 730 | list_add_tail(&msg->m_list, &msq->q_messages); |
1da177e4 LT |
731 | msq->q_cbytes += msgsz; |
732 | msq->q_qnum++; | |
3ac88a41 KK |
733 | atomic_add(msgsz, &ns->msg_bytes); |
734 | atomic_inc(&ns->msg_hdrs); | |
1da177e4 | 735 | } |
5a06a363 | 736 | |
1da177e4 LT |
737 | err = 0; |
738 | msg = NULL; | |
739 | ||
740 | out_unlock_free: | |
741 | msg_unlock(msq); | |
742 | out_free: | |
5a06a363 | 743 | if (msg != NULL) |
1da177e4 LT |
744 | free_msg(msg); |
745 | return err; | |
746 | } | |
747 | ||
651971cb | 748 | asmlinkage long |
749 | sys_msgsnd(int msqid, struct msgbuf __user *msgp, size_t msgsz, int msgflg) | |
750 | { | |
751 | long mtype; | |
752 | ||
753 | if (get_user(mtype, &msgp->mtype)) | |
754 | return -EFAULT; | |
755 | return do_msgsnd(msqid, mtype, msgp->mtext, msgsz, msgflg); | |
756 | } | |
757 | ||
5a06a363 | 758 | static inline int convert_mode(long *msgtyp, int msgflg) |
1da177e4 | 759 | { |
5a06a363 | 760 | /* |
1da177e4 LT |
761 | * find message of correct type. |
762 | * msgtyp = 0 => get first. | |
763 | * msgtyp > 0 => get first message of matching type. | |
5a06a363 | 764 | * msgtyp < 0 => get message with least type must be < abs(msgtype). |
1da177e4 | 765 | */ |
5a06a363 | 766 | if (*msgtyp == 0) |
1da177e4 | 767 | return SEARCH_ANY; |
5a06a363 IM |
768 | if (*msgtyp < 0) { |
769 | *msgtyp = -*msgtyp; | |
1da177e4 LT |
770 | return SEARCH_LESSEQUAL; |
771 | } | |
5a06a363 | 772 | if (msgflg & MSG_EXCEPT) |
1da177e4 LT |
773 | return SEARCH_NOTEQUAL; |
774 | return SEARCH_EQUAL; | |
775 | } | |
776 | ||
651971cb | 777 | long do_msgrcv(int msqid, long *pmtype, void __user *mtext, |
778 | size_t msgsz, long msgtyp, int msgflg) | |
1da177e4 LT |
779 | { |
780 | struct msg_queue *msq; | |
781 | struct msg_msg *msg; | |
782 | int mode; | |
1e786937 | 783 | struct ipc_namespace *ns; |
1da177e4 LT |
784 | |
785 | if (msqid < 0 || (long) msgsz < 0) | |
786 | return -EINVAL; | |
5a06a363 | 787 | mode = convert_mode(&msgtyp, msgflg); |
1e786937 | 788 | ns = current->nsproxy->ipc_ns; |
1da177e4 | 789 | |
023a5355 ND |
790 | msq = msg_lock_check(ns, msqid); |
791 | if (IS_ERR(msq)) | |
792 | return PTR_ERR(msq); | |
1da177e4 LT |
793 | |
794 | for (;;) { | |
795 | struct msg_receiver msr_d; | |
5a06a363 | 796 | struct list_head *tmp; |
1da177e4 LT |
797 | |
798 | msg = ERR_PTR(-EACCES); | |
5a06a363 | 799 | if (ipcperms(&msq->q_perm, S_IRUGO)) |
1da177e4 LT |
800 | goto out_unlock; |
801 | ||
802 | msg = ERR_PTR(-EAGAIN); | |
803 | tmp = msq->q_messages.next; | |
804 | while (tmp != &msq->q_messages) { | |
805 | struct msg_msg *walk_msg; | |
5a06a363 IM |
806 | |
807 | walk_msg = list_entry(tmp, struct msg_msg, m_list); | |
808 | if (testmsg(walk_msg, msgtyp, mode) && | |
809 | !security_msg_queue_msgrcv(msq, walk_msg, current, | |
810 | msgtyp, mode)) { | |
811 | ||
1da177e4 | 812 | msg = walk_msg; |
5a06a363 IM |
813 | if (mode == SEARCH_LESSEQUAL && |
814 | walk_msg->m_type != 1) { | |
815 | msg = walk_msg; | |
816 | msgtyp = walk_msg->m_type - 1; | |
1da177e4 | 817 | } else { |
5a06a363 | 818 | msg = walk_msg; |
1da177e4 LT |
819 | break; |
820 | } | |
821 | } | |
822 | tmp = tmp->next; | |
823 | } | |
5a06a363 IM |
824 | if (!IS_ERR(msg)) { |
825 | /* | |
826 | * Found a suitable message. | |
827 | * Unlink it from the queue. | |
828 | */ | |
1da177e4 LT |
829 | if ((msgsz < msg->m_ts) && !(msgflg & MSG_NOERROR)) { |
830 | msg = ERR_PTR(-E2BIG); | |
831 | goto out_unlock; | |
832 | } | |
833 | list_del(&msg->m_list); | |
834 | msq->q_qnum--; | |
835 | msq->q_rtime = get_seconds(); | |
b488893a | 836 | msq->q_lrpid = task_tgid_vnr(current); |
1da177e4 | 837 | msq->q_cbytes -= msg->m_ts; |
3ac88a41 KK |
838 | atomic_sub(msg->m_ts, &ns->msg_bytes); |
839 | atomic_dec(&ns->msg_hdrs); | |
5a06a363 | 840 | ss_wakeup(&msq->q_senders, 0); |
1da177e4 LT |
841 | msg_unlock(msq); |
842 | break; | |
843 | } | |
844 | /* No message waiting. Wait for a message */ | |
845 | if (msgflg & IPC_NOWAIT) { | |
846 | msg = ERR_PTR(-ENOMSG); | |
847 | goto out_unlock; | |
848 | } | |
5a06a363 | 849 | list_add_tail(&msr_d.r_list, &msq->q_receivers); |
1da177e4 LT |
850 | msr_d.r_tsk = current; |
851 | msr_d.r_msgtype = msgtyp; | |
852 | msr_d.r_mode = mode; | |
5a06a363 | 853 | if (msgflg & MSG_NOERROR) |
1da177e4 | 854 | msr_d.r_maxsize = INT_MAX; |
5a06a363 | 855 | else |
1da177e4 LT |
856 | msr_d.r_maxsize = msgsz; |
857 | msr_d.r_msg = ERR_PTR(-EAGAIN); | |
858 | current->state = TASK_INTERRUPTIBLE; | |
859 | msg_unlock(msq); | |
860 | ||
861 | schedule(); | |
862 | ||
863 | /* Lockless receive, part 1: | |
864 | * Disable preemption. We don't hold a reference to the queue | |
865 | * and getting a reference would defeat the idea of a lockless | |
866 | * operation, thus the code relies on rcu to guarantee the | |
867 | * existance of msq: | |
868 | * Prior to destruction, expunge_all(-EIRDM) changes r_msg. | |
869 | * Thus if r_msg is -EAGAIN, then the queue not yet destroyed. | |
870 | * rcu_read_lock() prevents preemption between reading r_msg | |
871 | * and the spin_lock() inside ipc_lock_by_ptr(). | |
872 | */ | |
873 | rcu_read_lock(); | |
874 | ||
875 | /* Lockless receive, part 2: | |
876 | * Wait until pipelined_send or expunge_all are outside of | |
877 | * wake_up_process(). There is a race with exit(), see | |
878 | * ipc/mqueue.c for the details. | |
879 | */ | |
5a06a363 | 880 | msg = (struct msg_msg*)msr_d.r_msg; |
1da177e4 LT |
881 | while (msg == NULL) { |
882 | cpu_relax(); | |
5a06a363 | 883 | msg = (struct msg_msg *)msr_d.r_msg; |
1da177e4 LT |
884 | } |
885 | ||
886 | /* Lockless receive, part 3: | |
887 | * If there is a message or an error then accept it without | |
888 | * locking. | |
889 | */ | |
5a06a363 | 890 | if (msg != ERR_PTR(-EAGAIN)) { |
1da177e4 LT |
891 | rcu_read_unlock(); |
892 | break; | |
893 | } | |
894 | ||
895 | /* Lockless receive, part 3: | |
896 | * Acquire the queue spinlock. | |
897 | */ | |
898 | ipc_lock_by_ptr(&msq->q_perm); | |
899 | rcu_read_unlock(); | |
900 | ||
901 | /* Lockless receive, part 4: | |
902 | * Repeat test after acquiring the spinlock. | |
903 | */ | |
904 | msg = (struct msg_msg*)msr_d.r_msg; | |
5a06a363 | 905 | if (msg != ERR_PTR(-EAGAIN)) |
1da177e4 LT |
906 | goto out_unlock; |
907 | ||
908 | list_del(&msr_d.r_list); | |
909 | if (signal_pending(current)) { | |
910 | msg = ERR_PTR(-ERESTARTNOHAND); | |
911 | out_unlock: | |
912 | msg_unlock(msq); | |
913 | break; | |
914 | } | |
915 | } | |
916 | if (IS_ERR(msg)) | |
5a06a363 | 917 | return PTR_ERR(msg); |
1da177e4 LT |
918 | |
919 | msgsz = (msgsz > msg->m_ts) ? msg->m_ts : msgsz; | |
651971cb | 920 | *pmtype = msg->m_type; |
921 | if (store_msg(mtext, msg, msgsz)) | |
5a06a363 | 922 | msgsz = -EFAULT; |
651971cb | 923 | |
1da177e4 | 924 | free_msg(msg); |
5a06a363 | 925 | |
1da177e4 LT |
926 | return msgsz; |
927 | } | |
928 | ||
651971cb | 929 | asmlinkage long sys_msgrcv(int msqid, struct msgbuf __user *msgp, size_t msgsz, |
930 | long msgtyp, int msgflg) | |
931 | { | |
932 | long err, mtype; | |
933 | ||
934 | err = do_msgrcv(msqid, &mtype, msgp->mtext, msgsz, msgtyp, msgflg); | |
935 | if (err < 0) | |
936 | goto out; | |
937 | ||
938 | if (put_user(mtype, &msgp->mtype)) | |
939 | err = -EFAULT; | |
940 | out: | |
941 | return err; | |
942 | } | |
943 | ||
1da177e4 | 944 | #ifdef CONFIG_PROC_FS |
19b4946c | 945 | static int sysvipc_msg_proc_show(struct seq_file *s, void *it) |
1da177e4 | 946 | { |
19b4946c MW |
947 | struct msg_queue *msq = it; |
948 | ||
949 | return seq_printf(s, | |
5a06a363 IM |
950 | "%10d %10d %4o %10lu %10lu %5u %5u %5u %5u %5u %5u %10lu %10lu %10lu\n", |
951 | msq->q_perm.key, | |
7ca7e564 | 952 | msq->q_perm.id, |
5a06a363 IM |
953 | msq->q_perm.mode, |
954 | msq->q_cbytes, | |
955 | msq->q_qnum, | |
956 | msq->q_lspid, | |
957 | msq->q_lrpid, | |
958 | msq->q_perm.uid, | |
959 | msq->q_perm.gid, | |
960 | msq->q_perm.cuid, | |
961 | msq->q_perm.cgid, | |
962 | msq->q_stime, | |
963 | msq->q_rtime, | |
964 | msq->q_ctime); | |
1da177e4 LT |
965 | } |
966 | #endif |