Commit | Line | Data |
---|---|---|
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 | ||
1e786937 | 70 | static struct ipc_ids init_msg_ids; |
1da177e4 | 71 | |
1e786937 | 72 | #define msg_ids(ns) (*((ns)->ids[IPC_MSG_IDS])) |
1da177e4 | 73 | |
1e786937 | 74 | #define msg_unlock(msq) ipc_unlock(&(msq)->q_perm) |
1b531f21 | 75 | #define msg_buildid(id, seq) ipc_buildid(id, seq) |
1e786937 | 76 | |
7ca7e564 | 77 | static void freeque(struct ipc_namespace *, struct msg_queue *); |
7748dbfa | 78 | static int newque(struct ipc_namespace *, struct ipc_params *); |
1da177e4 | 79 | #ifdef CONFIG_PROC_FS |
19b4946c | 80 | static int sysvipc_msg_proc_show(struct seq_file *s, void *it); |
1da177e4 LT |
81 | #endif |
82 | ||
7d69a1f4 | 83 | static void __msg_init_ns(struct ipc_namespace *ns, struct ipc_ids *ids) |
1e786937 KK |
84 | { |
85 | ns->ids[IPC_MSG_IDS] = ids; | |
86 | ns->msg_ctlmax = MSGMAX; | |
87 | ns->msg_ctlmnb = MSGMNB; | |
88 | ns->msg_ctlmni = MSGMNI; | |
3ac88a41 KK |
89 | atomic_set(&ns->msg_bytes, 0); |
90 | atomic_set(&ns->msg_hdrs, 0); | |
7ca7e564 | 91 | ipc_init_ids(ids); |
1e786937 KK |
92 | } |
93 | ||
ae5e1b22 | 94 | #ifdef CONFIG_IPC_NS |
1e786937 KK |
95 | int msg_init_ns(struct ipc_namespace *ns) |
96 | { | |
97 | struct ipc_ids *ids; | |
98 | ||
99 | ids = kmalloc(sizeof(struct ipc_ids), GFP_KERNEL); | |
100 | if (ids == NULL) | |
101 | return -ENOMEM; | |
102 | ||
103 | __msg_init_ns(ns, ids); | |
104 | return 0; | |
105 | } | |
106 | ||
107 | void msg_exit_ns(struct ipc_namespace *ns) | |
108 | { | |
1e786937 | 109 | struct msg_queue *msq; |
b1ed88b4 | 110 | struct kern_ipc_perm *perm; |
7ca7e564 ND |
111 | int next_id; |
112 | int total, in_use; | |
1e786937 | 113 | |
3e148c79 | 114 | down_write(&msg_ids(ns).rw_mutex); |
7ca7e564 ND |
115 | |
116 | in_use = msg_ids(ns).in_use; | |
117 | ||
118 | for (total = 0, next_id = 0; total < in_use; next_id++) { | |
b1ed88b4 PP |
119 | perm = idr_find(&msg_ids(ns).ipcs_idr, next_id); |
120 | if (perm == NULL) | |
1e786937 | 121 | continue; |
b1ed88b4 PP |
122 | ipc_lock_by_ptr(perm); |
123 | msq = container_of(perm, struct msg_queue, q_perm); | |
7ca7e564 ND |
124 | freeque(ns, msq); |
125 | total++; | |
1e786937 | 126 | } |
3e148c79 ND |
127 | |
128 | up_write(&msg_ids(ns).rw_mutex); | |
1e786937 KK |
129 | |
130 | kfree(ns->ids[IPC_MSG_IDS]); | |
131 | ns->ids[IPC_MSG_IDS] = NULL; | |
132 | } | |
ae5e1b22 | 133 | #endif |
1e786937 | 134 | |
5a06a363 | 135 | void __init msg_init(void) |
1da177e4 | 136 | { |
1e786937 | 137 | __msg_init_ns(&init_ipc_ns, &init_msg_ids); |
19b4946c MW |
138 | ipc_init_proc_interface("sysvipc/msg", |
139 | " key msqid perms cbytes qnum lspid lrpid uid gid cuid cgid stime rtime ctime\n", | |
1e786937 | 140 | IPC_MSG_IDS, sysvipc_msg_proc_show); |
1da177e4 LT |
141 | } |
142 | ||
3e148c79 ND |
143 | /* |
144 | * This routine is called in the paths where the rw_mutex is held to protect | |
145 | * access to the idr tree. | |
146 | */ | |
147 | static inline struct msg_queue *msg_lock_check_down(struct ipc_namespace *ns, | |
148 | int id) | |
149 | { | |
150 | struct kern_ipc_perm *ipcp = ipc_lock_check_down(&msg_ids(ns), id); | |
151 | ||
b1ed88b4 PP |
152 | if (IS_ERR(ipcp)) |
153 | return (struct msg_queue *)ipcp; | |
154 | ||
3e148c79 ND |
155 | return container_of(ipcp, struct msg_queue, q_perm); |
156 | } | |
157 | ||
158 | /* | |
159 | * msg_lock_(check_) routines are called in the paths where the rw_mutex | |
160 | * is not held. | |
161 | */ | |
023a5355 ND |
162 | static inline struct msg_queue *msg_lock(struct ipc_namespace *ns, int id) |
163 | { | |
03f02c76 ND |
164 | struct kern_ipc_perm *ipcp = ipc_lock(&msg_ids(ns), id); |
165 | ||
b1ed88b4 PP |
166 | if (IS_ERR(ipcp)) |
167 | return (struct msg_queue *)ipcp; | |
168 | ||
03f02c76 | 169 | return container_of(ipcp, struct msg_queue, q_perm); |
023a5355 ND |
170 | } |
171 | ||
172 | static inline struct msg_queue *msg_lock_check(struct ipc_namespace *ns, | |
173 | int id) | |
174 | { | |
03f02c76 ND |
175 | struct kern_ipc_perm *ipcp = ipc_lock_check(&msg_ids(ns), id); |
176 | ||
b1ed88b4 PP |
177 | if (IS_ERR(ipcp)) |
178 | return (struct msg_queue *)ipcp; | |
179 | ||
03f02c76 | 180 | return container_of(ipcp, struct msg_queue, q_perm); |
023a5355 ND |
181 | } |
182 | ||
7ca7e564 ND |
183 | static inline void msg_rmid(struct ipc_namespace *ns, struct msg_queue *s) |
184 | { | |
185 | ipc_rmid(&msg_ids(ns), &s->q_perm); | |
186 | } | |
187 | ||
f4566f04 ND |
188 | /** |
189 | * newque - Create a new msg queue | |
190 | * @ns: namespace | |
191 | * @params: ptr to the structure that contains the key and msgflg | |
192 | * | |
3e148c79 | 193 | * Called with msg_ids.rw_mutex held (writer) |
f4566f04 | 194 | */ |
7748dbfa | 195 | static int newque(struct ipc_namespace *ns, struct ipc_params *params) |
1da177e4 | 196 | { |
1da177e4 | 197 | struct msg_queue *msq; |
5a06a363 | 198 | int id, retval; |
7748dbfa ND |
199 | key_t key = params->key; |
200 | int msgflg = params->flg; | |
1da177e4 | 201 | |
5a06a363 IM |
202 | msq = ipc_rcu_alloc(sizeof(*msq)); |
203 | if (!msq) | |
1da177e4 LT |
204 | return -ENOMEM; |
205 | ||
5a06a363 | 206 | msq->q_perm.mode = msgflg & S_IRWXUGO; |
1da177e4 LT |
207 | msq->q_perm.key = key; |
208 | ||
209 | msq->q_perm.security = NULL; | |
210 | retval = security_msg_queue_alloc(msq); | |
211 | if (retval) { | |
212 | ipc_rcu_putref(msq); | |
213 | return retval; | |
214 | } | |
215 | ||
7ca7e564 ND |
216 | /* |
217 | * ipc_addid() locks msq | |
218 | */ | |
1e786937 | 219 | id = ipc_addid(&msg_ids(ns), &msq->q_perm, ns->msg_ctlmni); |
283bb7fa | 220 | if (id < 0) { |
1da177e4 LT |
221 | security_msg_queue_free(msq); |
222 | ipc_rcu_putref(msq); | |
283bb7fa | 223 | return id; |
1da177e4 LT |
224 | } |
225 | ||
1b531f21 | 226 | msq->q_perm.id = msg_buildid(id, msq->q_perm.seq); |
1da177e4 LT |
227 | msq->q_stime = msq->q_rtime = 0; |
228 | msq->q_ctime = get_seconds(); | |
229 | msq->q_cbytes = msq->q_qnum = 0; | |
1e786937 | 230 | msq->q_qbytes = ns->msg_ctlmnb; |
1da177e4 LT |
231 | msq->q_lspid = msq->q_lrpid = 0; |
232 | INIT_LIST_HEAD(&msq->q_messages); | |
233 | INIT_LIST_HEAD(&msq->q_receivers); | |
234 | INIT_LIST_HEAD(&msq->q_senders); | |
7ca7e564 | 235 | |
1da177e4 LT |
236 | msg_unlock(msq); |
237 | ||
7ca7e564 | 238 | return msq->q_perm.id; |
1da177e4 LT |
239 | } |
240 | ||
5a06a363 | 241 | static inline void ss_add(struct msg_queue *msq, struct msg_sender *mss) |
1da177e4 | 242 | { |
5a06a363 IM |
243 | mss->tsk = current; |
244 | current->state = TASK_INTERRUPTIBLE; | |
245 | list_add_tail(&mss->list, &msq->q_senders); | |
1da177e4 LT |
246 | } |
247 | ||
5a06a363 | 248 | static inline void ss_del(struct msg_sender *mss) |
1da177e4 | 249 | { |
5a06a363 | 250 | if (mss->list.next != NULL) |
1da177e4 LT |
251 | list_del(&mss->list); |
252 | } | |
253 | ||
5a06a363 | 254 | static void ss_wakeup(struct list_head *h, int kill) |
1da177e4 LT |
255 | { |
256 | struct list_head *tmp; | |
257 | ||
258 | tmp = h->next; | |
259 | while (tmp != h) { | |
5a06a363 IM |
260 | struct msg_sender *mss; |
261 | ||
262 | mss = list_entry(tmp, struct msg_sender, list); | |
1da177e4 | 263 | tmp = tmp->next; |
5a06a363 IM |
264 | if (kill) |
265 | mss->list.next = NULL; | |
1da177e4 LT |
266 | wake_up_process(mss->tsk); |
267 | } | |
268 | } | |
269 | ||
5a06a363 | 270 | static void expunge_all(struct msg_queue *msq, int res) |
1da177e4 LT |
271 | { |
272 | struct list_head *tmp; | |
273 | ||
274 | tmp = msq->q_receivers.next; | |
275 | while (tmp != &msq->q_receivers) { | |
5a06a363 IM |
276 | struct msg_receiver *msr; |
277 | ||
278 | msr = list_entry(tmp, struct msg_receiver, r_list); | |
1da177e4 LT |
279 | tmp = tmp->next; |
280 | msr->r_msg = NULL; | |
281 | wake_up_process(msr->r_tsk); | |
282 | smp_mb(); | |
283 | msr->r_msg = ERR_PTR(res); | |
284 | } | |
285 | } | |
5a06a363 IM |
286 | |
287 | /* | |
288 | * freeque() wakes up waiters on the sender and receiver waiting queue, | |
f4566f04 ND |
289 | * removes the message queue from message queue ID IDR, and cleans up all the |
290 | * messages associated with this queue. | |
1da177e4 | 291 | * |
3e148c79 ND |
292 | * msg_ids.rw_mutex (writer) and the spinlock for this message queue are held |
293 | * before freeque() is called. msg_ids.rw_mutex remains locked on exit. | |
1da177e4 | 294 | */ |
7ca7e564 | 295 | static void freeque(struct ipc_namespace *ns, struct msg_queue *msq) |
1da177e4 LT |
296 | { |
297 | struct list_head *tmp; | |
298 | ||
5a06a363 IM |
299 | expunge_all(msq, -EIDRM); |
300 | ss_wakeup(&msq->q_senders, 1); | |
7ca7e564 | 301 | msg_rmid(ns, msq); |
1da177e4 | 302 | msg_unlock(msq); |
5a06a363 | 303 | |
1da177e4 | 304 | tmp = msq->q_messages.next; |
5a06a363 IM |
305 | while (tmp != &msq->q_messages) { |
306 | struct msg_msg *msg = list_entry(tmp, struct msg_msg, m_list); | |
307 | ||
1da177e4 | 308 | tmp = tmp->next; |
3ac88a41 | 309 | atomic_dec(&ns->msg_hdrs); |
1da177e4 LT |
310 | free_msg(msg); |
311 | } | |
3ac88a41 | 312 | atomic_sub(msq->q_cbytes, &ns->msg_bytes); |
1da177e4 LT |
313 | security_msg_queue_free(msq); |
314 | ipc_rcu_putref(msq); | |
315 | } | |
316 | ||
f4566f04 | 317 | /* |
3e148c79 | 318 | * Called with msg_ids.rw_mutex and ipcp locked. |
f4566f04 | 319 | */ |
03f02c76 | 320 | static inline int msg_security(struct kern_ipc_perm *ipcp, int msgflg) |
7748dbfa | 321 | { |
03f02c76 ND |
322 | struct msg_queue *msq = container_of(ipcp, struct msg_queue, q_perm); |
323 | ||
324 | return security_msg_queue_associate(msq, msgflg); | |
7748dbfa ND |
325 | } |
326 | ||
5a06a363 | 327 | asmlinkage long sys_msgget(key_t key, int msgflg) |
1da177e4 | 328 | { |
1e786937 | 329 | struct ipc_namespace *ns; |
7748dbfa ND |
330 | struct ipc_ops msg_ops; |
331 | struct ipc_params msg_params; | |
1e786937 KK |
332 | |
333 | ns = current->nsproxy->ipc_ns; | |
7ca7e564 | 334 | |
7748dbfa ND |
335 | msg_ops.getnew = newque; |
336 | msg_ops.associate = msg_security; | |
337 | msg_ops.more_checks = NULL; | |
338 | ||
339 | msg_params.key = key; | |
340 | msg_params.flg = msgflg; | |
5a06a363 | 341 | |
7748dbfa | 342 | return ipcget(ns, &msg_ids(ns), &msg_ops, &msg_params); |
1da177e4 LT |
343 | } |
344 | ||
5a06a363 IM |
345 | static inline unsigned long |
346 | copy_msqid_to_user(void __user *buf, struct msqid64_ds *in, int version) | |
1da177e4 LT |
347 | { |
348 | switch(version) { | |
349 | case IPC_64: | |
5a06a363 | 350 | return copy_to_user(buf, in, sizeof(*in)); |
1da177e4 | 351 | case IPC_OLD: |
5a06a363 | 352 | { |
1da177e4 LT |
353 | struct msqid_ds out; |
354 | ||
5a06a363 | 355 | memset(&out, 0, sizeof(out)); |
1da177e4 LT |
356 | |
357 | ipc64_perm_to_ipc_perm(&in->msg_perm, &out.msg_perm); | |
358 | ||
359 | out.msg_stime = in->msg_stime; | |
360 | out.msg_rtime = in->msg_rtime; | |
361 | out.msg_ctime = in->msg_ctime; | |
362 | ||
5a06a363 | 363 | if (in->msg_cbytes > USHRT_MAX) |
1da177e4 LT |
364 | out.msg_cbytes = USHRT_MAX; |
365 | else | |
366 | out.msg_cbytes = in->msg_cbytes; | |
367 | out.msg_lcbytes = in->msg_cbytes; | |
368 | ||
5a06a363 | 369 | if (in->msg_qnum > USHRT_MAX) |
1da177e4 LT |
370 | out.msg_qnum = USHRT_MAX; |
371 | else | |
372 | out.msg_qnum = in->msg_qnum; | |
373 | ||
5a06a363 | 374 | if (in->msg_qbytes > USHRT_MAX) |
1da177e4 LT |
375 | out.msg_qbytes = USHRT_MAX; |
376 | else | |
377 | out.msg_qbytes = in->msg_qbytes; | |
378 | out.msg_lqbytes = in->msg_qbytes; | |
379 | ||
380 | out.msg_lspid = in->msg_lspid; | |
381 | out.msg_lrpid = in->msg_lrpid; | |
382 | ||
5a06a363 IM |
383 | return copy_to_user(buf, &out, sizeof(out)); |
384 | } | |
1da177e4 LT |
385 | default: |
386 | return -EINVAL; | |
387 | } | |
388 | } | |
389 | ||
390 | struct msq_setbuf { | |
391 | unsigned long qbytes; | |
392 | uid_t uid; | |
393 | gid_t gid; | |
394 | mode_t mode; | |
395 | }; | |
396 | ||
5a06a363 IM |
397 | static inline unsigned long |
398 | copy_msqid_from_user(struct msq_setbuf *out, void __user *buf, int version) | |
1da177e4 LT |
399 | { |
400 | switch(version) { | |
401 | case IPC_64: | |
5a06a363 | 402 | { |
1da177e4 LT |
403 | struct msqid64_ds tbuf; |
404 | ||
5a06a363 | 405 | if (copy_from_user(&tbuf, buf, sizeof(tbuf))) |
1da177e4 LT |
406 | return -EFAULT; |
407 | ||
408 | out->qbytes = tbuf.msg_qbytes; | |
409 | out->uid = tbuf.msg_perm.uid; | |
410 | out->gid = tbuf.msg_perm.gid; | |
411 | out->mode = tbuf.msg_perm.mode; | |
412 | ||
413 | return 0; | |
5a06a363 | 414 | } |
1da177e4 | 415 | case IPC_OLD: |
5a06a363 | 416 | { |
1da177e4 LT |
417 | struct msqid_ds tbuf_old; |
418 | ||
5a06a363 | 419 | if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old))) |
1da177e4 LT |
420 | return -EFAULT; |
421 | ||
422 | out->uid = tbuf_old.msg_perm.uid; | |
423 | out->gid = tbuf_old.msg_perm.gid; | |
424 | out->mode = tbuf_old.msg_perm.mode; | |
425 | ||
5a06a363 | 426 | if (tbuf_old.msg_qbytes == 0) |
1da177e4 LT |
427 | out->qbytes = tbuf_old.msg_lqbytes; |
428 | else | |
429 | out->qbytes = tbuf_old.msg_qbytes; | |
430 | ||
431 | return 0; | |
5a06a363 | 432 | } |
1da177e4 LT |
433 | default: |
434 | return -EINVAL; | |
435 | } | |
436 | } | |
437 | ||
5a06a363 | 438 | asmlinkage long sys_msgctl(int msqid, int cmd, struct msqid_ds __user *buf) |
1da177e4 | 439 | { |
1da177e4 | 440 | struct kern_ipc_perm *ipcp; |
8e1c091c | 441 | struct msq_setbuf uninitialized_var(setbuf); |
5a06a363 IM |
442 | struct msg_queue *msq; |
443 | int err, version; | |
1e786937 | 444 | struct ipc_namespace *ns; |
5a06a363 | 445 | |
1da177e4 LT |
446 | if (msqid < 0 || cmd < 0) |
447 | return -EINVAL; | |
448 | ||
449 | version = ipc_parse_version(&cmd); | |
1e786937 | 450 | ns = current->nsproxy->ipc_ns; |
1da177e4 LT |
451 | |
452 | switch (cmd) { | |
5a06a363 IM |
453 | case IPC_INFO: |
454 | case MSG_INFO: | |
455 | { | |
1da177e4 LT |
456 | struct msginfo msginfo; |
457 | int max_id; | |
5a06a363 | 458 | |
1da177e4 LT |
459 | if (!buf) |
460 | return -EFAULT; | |
5a06a363 IM |
461 | /* |
462 | * We must not return kernel stack data. | |
1da177e4 LT |
463 | * due to padding, it's not enough |
464 | * to set all member fields. | |
465 | */ | |
1da177e4 LT |
466 | err = security_msg_queue_msgctl(NULL, cmd); |
467 | if (err) | |
468 | return err; | |
469 | ||
5a06a363 | 470 | memset(&msginfo, 0, sizeof(msginfo)); |
1e786937 KK |
471 | msginfo.msgmni = ns->msg_ctlmni; |
472 | msginfo.msgmax = ns->msg_ctlmax; | |
473 | msginfo.msgmnb = ns->msg_ctlmnb; | |
1da177e4 LT |
474 | msginfo.msgssz = MSGSSZ; |
475 | msginfo.msgseg = MSGSEG; | |
3e148c79 | 476 | down_read(&msg_ids(ns).rw_mutex); |
1da177e4 | 477 | if (cmd == MSG_INFO) { |
1e786937 | 478 | msginfo.msgpool = msg_ids(ns).in_use; |
3ac88a41 KK |
479 | msginfo.msgmap = atomic_read(&ns->msg_hdrs); |
480 | msginfo.msgtql = atomic_read(&ns->msg_bytes); | |
1da177e4 LT |
481 | } else { |
482 | msginfo.msgmap = MSGMAP; | |
483 | msginfo.msgpool = MSGPOOL; | |
484 | msginfo.msgtql = MSGTQL; | |
485 | } | |
7ca7e564 | 486 | max_id = ipc_get_maxid(&msg_ids(ns)); |
3e148c79 | 487 | up_read(&msg_ids(ns).rw_mutex); |
5a06a363 | 488 | if (copy_to_user(buf, &msginfo, sizeof(struct msginfo))) |
1da177e4 | 489 | return -EFAULT; |
5a06a363 | 490 | return (max_id < 0) ? 0 : max_id; |
1da177e4 | 491 | } |
7ca7e564 | 492 | case MSG_STAT: /* msqid is an index rather than a msg queue id */ |
1da177e4 LT |
493 | case IPC_STAT: |
494 | { | |
495 | struct msqid64_ds tbuf; | |
496 | int success_return; | |
5a06a363 | 497 | |
1da177e4 LT |
498 | if (!buf) |
499 | return -EFAULT; | |
1da177e4 | 500 | |
5a06a363 | 501 | if (cmd == MSG_STAT) { |
023a5355 ND |
502 | msq = msg_lock(ns, msqid); |
503 | if (IS_ERR(msq)) | |
504 | return PTR_ERR(msq); | |
7ca7e564 | 505 | success_return = msq->q_perm.id; |
1da177e4 | 506 | } else { |
023a5355 ND |
507 | msq = msg_lock_check(ns, msqid); |
508 | if (IS_ERR(msq)) | |
509 | return PTR_ERR(msq); | |
1da177e4 LT |
510 | success_return = 0; |
511 | } | |
512 | err = -EACCES; | |
5a06a363 | 513 | if (ipcperms(&msq->q_perm, S_IRUGO)) |
1da177e4 LT |
514 | goto out_unlock; |
515 | ||
516 | err = security_msg_queue_msgctl(msq, cmd); | |
517 | if (err) | |
518 | goto out_unlock; | |
519 | ||
023a5355 ND |
520 | memset(&tbuf, 0, sizeof(tbuf)); |
521 | ||
1da177e4 LT |
522 | kernel_to_ipc64_perm(&msq->q_perm, &tbuf.msg_perm); |
523 | tbuf.msg_stime = msq->q_stime; | |
524 | tbuf.msg_rtime = msq->q_rtime; | |
525 | tbuf.msg_ctime = msq->q_ctime; | |
526 | tbuf.msg_cbytes = msq->q_cbytes; | |
527 | tbuf.msg_qnum = msq->q_qnum; | |
528 | tbuf.msg_qbytes = msq->q_qbytes; | |
529 | tbuf.msg_lspid = msq->q_lspid; | |
530 | tbuf.msg_lrpid = msq->q_lrpid; | |
531 | msg_unlock(msq); | |
532 | if (copy_msqid_to_user(buf, &tbuf, version)) | |
533 | return -EFAULT; | |
534 | return success_return; | |
535 | } | |
536 | case IPC_SET: | |
537 | if (!buf) | |
538 | return -EFAULT; | |
5a06a363 | 539 | if (copy_msqid_from_user(&setbuf, buf, version)) |
1da177e4 | 540 | return -EFAULT; |
1da177e4 LT |
541 | break; |
542 | case IPC_RMID: | |
543 | break; | |
544 | default: | |
545 | return -EINVAL; | |
546 | } | |
547 | ||
3e148c79 ND |
548 | down_write(&msg_ids(ns).rw_mutex); |
549 | msq = msg_lock_check_down(ns, msqid); | |
023a5355 ND |
550 | if (IS_ERR(msq)) { |
551 | err = PTR_ERR(msq); | |
1da177e4 | 552 | goto out_up; |
023a5355 | 553 | } |
1da177e4 | 554 | |
1da177e4 | 555 | ipcp = &msq->q_perm; |
073115d6 SG |
556 | |
557 | err = audit_ipc_obj(ipcp); | |
558 | if (err) | |
559 | goto out_unlock_up; | |
8e1c091c | 560 | if (cmd == IPC_SET) { |
5a06a363 IM |
561 | err = audit_ipc_set_perm(setbuf.qbytes, setbuf.uid, setbuf.gid, |
562 | setbuf.mode); | |
ac03221a LK |
563 | if (err) |
564 | goto out_unlock_up; | |
565 | } | |
073115d6 | 566 | |
1da177e4 | 567 | err = -EPERM; |
5a06a363 | 568 | if (current->euid != ipcp->cuid && |
1da177e4 | 569 | current->euid != ipcp->uid && !capable(CAP_SYS_ADMIN)) |
5a06a363 | 570 | /* We _could_ check for CAP_CHOWN above, but we don't */ |
1da177e4 LT |
571 | goto out_unlock_up; |
572 | ||
573 | err = security_msg_queue_msgctl(msq, cmd); | |
574 | if (err) | |
575 | goto out_unlock_up; | |
576 | ||
577 | switch (cmd) { | |
578 | case IPC_SET: | |
579 | { | |
580 | err = -EPERM; | |
1e786937 | 581 | if (setbuf.qbytes > ns->msg_ctlmnb && !capable(CAP_SYS_RESOURCE)) |
1da177e4 LT |
582 | goto out_unlock_up; |
583 | ||
584 | msq->q_qbytes = setbuf.qbytes; | |
585 | ||
586 | ipcp->uid = setbuf.uid; | |
587 | ipcp->gid = setbuf.gid; | |
5a06a363 IM |
588 | ipcp->mode = (ipcp->mode & ~S_IRWXUGO) | |
589 | (S_IRWXUGO & setbuf.mode); | |
1da177e4 LT |
590 | msq->q_ctime = get_seconds(); |
591 | /* sleeping receivers might be excluded by | |
592 | * stricter permissions. | |
593 | */ | |
5a06a363 | 594 | expunge_all(msq, -EAGAIN); |
1da177e4 LT |
595 | /* sleeping senders might be able to send |
596 | * due to a larger queue size. | |
597 | */ | |
5a06a363 | 598 | ss_wakeup(&msq->q_senders, 0); |
1da177e4 LT |
599 | msg_unlock(msq); |
600 | break; | |
601 | } | |
602 | case IPC_RMID: | |
7ca7e564 | 603 | freeque(ns, msq); |
1da177e4 LT |
604 | break; |
605 | } | |
606 | err = 0; | |
607 | out_up: | |
3e148c79 | 608 | up_write(&msg_ids(ns).rw_mutex); |
1da177e4 LT |
609 | return err; |
610 | out_unlock_up: | |
611 | msg_unlock(msq); | |
612 | goto out_up; | |
613 | out_unlock: | |
614 | msg_unlock(msq); | |
615 | return err; | |
616 | } | |
617 | ||
5a06a363 | 618 | static int testmsg(struct msg_msg *msg, long type, int mode) |
1da177e4 LT |
619 | { |
620 | switch(mode) | |
621 | { | |
622 | case SEARCH_ANY: | |
623 | return 1; | |
624 | case SEARCH_LESSEQUAL: | |
5a06a363 | 625 | if (msg->m_type <=type) |
1da177e4 LT |
626 | return 1; |
627 | break; | |
628 | case SEARCH_EQUAL: | |
5a06a363 | 629 | if (msg->m_type == type) |
1da177e4 LT |
630 | return 1; |
631 | break; | |
632 | case SEARCH_NOTEQUAL: | |
5a06a363 | 633 | if (msg->m_type != type) |
1da177e4 LT |
634 | return 1; |
635 | break; | |
636 | } | |
637 | return 0; | |
638 | } | |
639 | ||
5a06a363 | 640 | static inline int pipelined_send(struct msg_queue *msq, struct msg_msg *msg) |
1da177e4 | 641 | { |
5a06a363 | 642 | struct list_head *tmp; |
1da177e4 LT |
643 | |
644 | tmp = msq->q_receivers.next; | |
645 | while (tmp != &msq->q_receivers) { | |
5a06a363 IM |
646 | struct msg_receiver *msr; |
647 | ||
648 | msr = list_entry(tmp, struct msg_receiver, r_list); | |
1da177e4 | 649 | tmp = tmp->next; |
5a06a363 IM |
650 | if (testmsg(msg, msr->r_msgtype, msr->r_mode) && |
651 | !security_msg_queue_msgrcv(msq, msg, msr->r_tsk, | |
652 | msr->r_msgtype, msr->r_mode)) { | |
653 | ||
1da177e4 | 654 | list_del(&msr->r_list); |
5a06a363 | 655 | if (msr->r_maxsize < msg->m_ts) { |
1da177e4 LT |
656 | msr->r_msg = NULL; |
657 | wake_up_process(msr->r_tsk); | |
658 | smp_mb(); | |
659 | msr->r_msg = ERR_PTR(-E2BIG); | |
660 | } else { | |
661 | msr->r_msg = NULL; | |
b488893a | 662 | msq->q_lrpid = task_pid_vnr(msr->r_tsk); |
1da177e4 LT |
663 | msq->q_rtime = get_seconds(); |
664 | wake_up_process(msr->r_tsk); | |
665 | smp_mb(); | |
666 | msr->r_msg = msg; | |
5a06a363 | 667 | |
1da177e4 LT |
668 | return 1; |
669 | } | |
670 | } | |
671 | } | |
672 | return 0; | |
673 | } | |
674 | ||
651971cb | 675 | long do_msgsnd(int msqid, long mtype, void __user *mtext, |
676 | size_t msgsz, int msgflg) | |
1da177e4 LT |
677 | { |
678 | struct msg_queue *msq; | |
679 | struct msg_msg *msg; | |
1da177e4 | 680 | int err; |
1e786937 KK |
681 | struct ipc_namespace *ns; |
682 | ||
683 | ns = current->nsproxy->ipc_ns; | |
5a06a363 | 684 | |
1e786937 | 685 | if (msgsz > ns->msg_ctlmax || (long) msgsz < 0 || msqid < 0) |
1da177e4 | 686 | return -EINVAL; |
1da177e4 LT |
687 | if (mtype < 1) |
688 | return -EINVAL; | |
689 | ||
651971cb | 690 | msg = load_msg(mtext, msgsz); |
5a06a363 | 691 | if (IS_ERR(msg)) |
1da177e4 LT |
692 | return PTR_ERR(msg); |
693 | ||
694 | msg->m_type = mtype; | |
695 | msg->m_ts = msgsz; | |
696 | ||
023a5355 ND |
697 | msq = msg_lock_check(ns, msqid); |
698 | if (IS_ERR(msq)) { | |
699 | err = PTR_ERR(msq); | |
1da177e4 | 700 | goto out_free; |
023a5355 | 701 | } |
1da177e4 LT |
702 | |
703 | for (;;) { | |
704 | struct msg_sender s; | |
705 | ||
5a06a363 | 706 | err = -EACCES; |
1da177e4 LT |
707 | if (ipcperms(&msq->q_perm, S_IWUGO)) |
708 | goto out_unlock_free; | |
709 | ||
710 | err = security_msg_queue_msgsnd(msq, msg, msgflg); | |
711 | if (err) | |
712 | goto out_unlock_free; | |
713 | ||
5a06a363 | 714 | if (msgsz + msq->q_cbytes <= msq->q_qbytes && |
1da177e4 LT |
715 | 1 + msq->q_qnum <= msq->q_qbytes) { |
716 | break; | |
717 | } | |
718 | ||
719 | /* queue full, wait: */ | |
5a06a363 IM |
720 | if (msgflg & IPC_NOWAIT) { |
721 | err = -EAGAIN; | |
1da177e4 LT |
722 | goto out_unlock_free; |
723 | } | |
724 | ss_add(msq, &s); | |
725 | ipc_rcu_getref(msq); | |
726 | msg_unlock(msq); | |
727 | schedule(); | |
728 | ||
729 | ipc_lock_by_ptr(&msq->q_perm); | |
730 | ipc_rcu_putref(msq); | |
731 | if (msq->q_perm.deleted) { | |
732 | err = -EIDRM; | |
733 | goto out_unlock_free; | |
734 | } | |
735 | ss_del(&s); | |
5a06a363 | 736 | |
1da177e4 | 737 | if (signal_pending(current)) { |
5a06a363 | 738 | err = -ERESTARTNOHAND; |
1da177e4 LT |
739 | goto out_unlock_free; |
740 | } | |
741 | } | |
742 | ||
b488893a | 743 | msq->q_lspid = task_tgid_vnr(current); |
1da177e4 LT |
744 | msq->q_stime = get_seconds(); |
745 | ||
5a06a363 | 746 | if (!pipelined_send(msq, msg)) { |
1da177e4 | 747 | /* noone is waiting for this message, enqueue it */ |
5a06a363 | 748 | list_add_tail(&msg->m_list, &msq->q_messages); |
1da177e4 LT |
749 | msq->q_cbytes += msgsz; |
750 | msq->q_qnum++; | |
3ac88a41 KK |
751 | atomic_add(msgsz, &ns->msg_bytes); |
752 | atomic_inc(&ns->msg_hdrs); | |
1da177e4 | 753 | } |
5a06a363 | 754 | |
1da177e4 LT |
755 | err = 0; |
756 | msg = NULL; | |
757 | ||
758 | out_unlock_free: | |
759 | msg_unlock(msq); | |
760 | out_free: | |
5a06a363 | 761 | if (msg != NULL) |
1da177e4 LT |
762 | free_msg(msg); |
763 | return err; | |
764 | } | |
765 | ||
651971cb | 766 | asmlinkage long |
767 | sys_msgsnd(int msqid, struct msgbuf __user *msgp, size_t msgsz, int msgflg) | |
768 | { | |
769 | long mtype; | |
770 | ||
771 | if (get_user(mtype, &msgp->mtype)) | |
772 | return -EFAULT; | |
773 | return do_msgsnd(msqid, mtype, msgp->mtext, msgsz, msgflg); | |
774 | } | |
775 | ||
5a06a363 | 776 | static inline int convert_mode(long *msgtyp, int msgflg) |
1da177e4 | 777 | { |
5a06a363 | 778 | /* |
1da177e4 LT |
779 | * find message of correct type. |
780 | * msgtyp = 0 => get first. | |
781 | * msgtyp > 0 => get first message of matching type. | |
5a06a363 | 782 | * msgtyp < 0 => get message with least type must be < abs(msgtype). |
1da177e4 | 783 | */ |
5a06a363 | 784 | if (*msgtyp == 0) |
1da177e4 | 785 | return SEARCH_ANY; |
5a06a363 IM |
786 | if (*msgtyp < 0) { |
787 | *msgtyp = -*msgtyp; | |
1da177e4 LT |
788 | return SEARCH_LESSEQUAL; |
789 | } | |
5a06a363 | 790 | if (msgflg & MSG_EXCEPT) |
1da177e4 LT |
791 | return SEARCH_NOTEQUAL; |
792 | return SEARCH_EQUAL; | |
793 | } | |
794 | ||
651971cb | 795 | long do_msgrcv(int msqid, long *pmtype, void __user *mtext, |
796 | size_t msgsz, long msgtyp, int msgflg) | |
1da177e4 LT |
797 | { |
798 | struct msg_queue *msq; | |
799 | struct msg_msg *msg; | |
800 | int mode; | |
1e786937 | 801 | struct ipc_namespace *ns; |
1da177e4 LT |
802 | |
803 | if (msqid < 0 || (long) msgsz < 0) | |
804 | return -EINVAL; | |
5a06a363 | 805 | mode = convert_mode(&msgtyp, msgflg); |
1e786937 | 806 | ns = current->nsproxy->ipc_ns; |
1da177e4 | 807 | |
023a5355 ND |
808 | msq = msg_lock_check(ns, msqid); |
809 | if (IS_ERR(msq)) | |
810 | return PTR_ERR(msq); | |
1da177e4 LT |
811 | |
812 | for (;;) { | |
813 | struct msg_receiver msr_d; | |
5a06a363 | 814 | struct list_head *tmp; |
1da177e4 LT |
815 | |
816 | msg = ERR_PTR(-EACCES); | |
5a06a363 | 817 | if (ipcperms(&msq->q_perm, S_IRUGO)) |
1da177e4 LT |
818 | goto out_unlock; |
819 | ||
820 | msg = ERR_PTR(-EAGAIN); | |
821 | tmp = msq->q_messages.next; | |
822 | while (tmp != &msq->q_messages) { | |
823 | struct msg_msg *walk_msg; | |
5a06a363 IM |
824 | |
825 | walk_msg = list_entry(tmp, struct msg_msg, m_list); | |
826 | if (testmsg(walk_msg, msgtyp, mode) && | |
827 | !security_msg_queue_msgrcv(msq, walk_msg, current, | |
828 | msgtyp, mode)) { | |
829 | ||
1da177e4 | 830 | msg = walk_msg; |
5a06a363 IM |
831 | if (mode == SEARCH_LESSEQUAL && |
832 | walk_msg->m_type != 1) { | |
833 | msg = walk_msg; | |
834 | msgtyp = walk_msg->m_type - 1; | |
1da177e4 | 835 | } else { |
5a06a363 | 836 | msg = walk_msg; |
1da177e4 LT |
837 | break; |
838 | } | |
839 | } | |
840 | tmp = tmp->next; | |
841 | } | |
5a06a363 IM |
842 | if (!IS_ERR(msg)) { |
843 | /* | |
844 | * Found a suitable message. | |
845 | * Unlink it from the queue. | |
846 | */ | |
1da177e4 LT |
847 | if ((msgsz < msg->m_ts) && !(msgflg & MSG_NOERROR)) { |
848 | msg = ERR_PTR(-E2BIG); | |
849 | goto out_unlock; | |
850 | } | |
851 | list_del(&msg->m_list); | |
852 | msq->q_qnum--; | |
853 | msq->q_rtime = get_seconds(); | |
b488893a | 854 | msq->q_lrpid = task_tgid_vnr(current); |
1da177e4 | 855 | msq->q_cbytes -= msg->m_ts; |
3ac88a41 KK |
856 | atomic_sub(msg->m_ts, &ns->msg_bytes); |
857 | atomic_dec(&ns->msg_hdrs); | |
5a06a363 | 858 | ss_wakeup(&msq->q_senders, 0); |
1da177e4 LT |
859 | msg_unlock(msq); |
860 | break; | |
861 | } | |
862 | /* No message waiting. Wait for a message */ | |
863 | if (msgflg & IPC_NOWAIT) { | |
864 | msg = ERR_PTR(-ENOMSG); | |
865 | goto out_unlock; | |
866 | } | |
5a06a363 | 867 | list_add_tail(&msr_d.r_list, &msq->q_receivers); |
1da177e4 LT |
868 | msr_d.r_tsk = current; |
869 | msr_d.r_msgtype = msgtyp; | |
870 | msr_d.r_mode = mode; | |
5a06a363 | 871 | if (msgflg & MSG_NOERROR) |
1da177e4 | 872 | msr_d.r_maxsize = INT_MAX; |
5a06a363 | 873 | else |
1da177e4 LT |
874 | msr_d.r_maxsize = msgsz; |
875 | msr_d.r_msg = ERR_PTR(-EAGAIN); | |
876 | current->state = TASK_INTERRUPTIBLE; | |
877 | msg_unlock(msq); | |
878 | ||
879 | schedule(); | |
880 | ||
881 | /* Lockless receive, part 1: | |
882 | * Disable preemption. We don't hold a reference to the queue | |
883 | * and getting a reference would defeat the idea of a lockless | |
884 | * operation, thus the code relies on rcu to guarantee the | |
885 | * existance of msq: | |
886 | * Prior to destruction, expunge_all(-EIRDM) changes r_msg. | |
887 | * Thus if r_msg is -EAGAIN, then the queue not yet destroyed. | |
888 | * rcu_read_lock() prevents preemption between reading r_msg | |
889 | * and the spin_lock() inside ipc_lock_by_ptr(). | |
890 | */ | |
891 | rcu_read_lock(); | |
892 | ||
893 | /* Lockless receive, part 2: | |
894 | * Wait until pipelined_send or expunge_all are outside of | |
895 | * wake_up_process(). There is a race with exit(), see | |
896 | * ipc/mqueue.c for the details. | |
897 | */ | |
5a06a363 | 898 | msg = (struct msg_msg*)msr_d.r_msg; |
1da177e4 LT |
899 | while (msg == NULL) { |
900 | cpu_relax(); | |
5a06a363 | 901 | msg = (struct msg_msg *)msr_d.r_msg; |
1da177e4 LT |
902 | } |
903 | ||
904 | /* Lockless receive, part 3: | |
905 | * If there is a message or an error then accept it without | |
906 | * locking. | |
907 | */ | |
5a06a363 | 908 | if (msg != ERR_PTR(-EAGAIN)) { |
1da177e4 LT |
909 | rcu_read_unlock(); |
910 | break; | |
911 | } | |
912 | ||
913 | /* Lockless receive, part 3: | |
914 | * Acquire the queue spinlock. | |
915 | */ | |
916 | ipc_lock_by_ptr(&msq->q_perm); | |
917 | rcu_read_unlock(); | |
918 | ||
919 | /* Lockless receive, part 4: | |
920 | * Repeat test after acquiring the spinlock. | |
921 | */ | |
922 | msg = (struct msg_msg*)msr_d.r_msg; | |
5a06a363 | 923 | if (msg != ERR_PTR(-EAGAIN)) |
1da177e4 LT |
924 | goto out_unlock; |
925 | ||
926 | list_del(&msr_d.r_list); | |
927 | if (signal_pending(current)) { | |
928 | msg = ERR_PTR(-ERESTARTNOHAND); | |
929 | out_unlock: | |
930 | msg_unlock(msq); | |
931 | break; | |
932 | } | |
933 | } | |
934 | if (IS_ERR(msg)) | |
5a06a363 | 935 | return PTR_ERR(msg); |
1da177e4 LT |
936 | |
937 | msgsz = (msgsz > msg->m_ts) ? msg->m_ts : msgsz; | |
651971cb | 938 | *pmtype = msg->m_type; |
939 | if (store_msg(mtext, msg, msgsz)) | |
5a06a363 | 940 | msgsz = -EFAULT; |
651971cb | 941 | |
1da177e4 | 942 | free_msg(msg); |
5a06a363 | 943 | |
1da177e4 LT |
944 | return msgsz; |
945 | } | |
946 | ||
651971cb | 947 | asmlinkage long sys_msgrcv(int msqid, struct msgbuf __user *msgp, size_t msgsz, |
948 | long msgtyp, int msgflg) | |
949 | { | |
950 | long err, mtype; | |
951 | ||
952 | err = do_msgrcv(msqid, &mtype, msgp->mtext, msgsz, msgtyp, msgflg); | |
953 | if (err < 0) | |
954 | goto out; | |
955 | ||
956 | if (put_user(mtype, &msgp->mtype)) | |
957 | err = -EFAULT; | |
958 | out: | |
959 | return err; | |
960 | } | |
961 | ||
1da177e4 | 962 | #ifdef CONFIG_PROC_FS |
19b4946c | 963 | static int sysvipc_msg_proc_show(struct seq_file *s, void *it) |
1da177e4 | 964 | { |
19b4946c MW |
965 | struct msg_queue *msq = it; |
966 | ||
967 | return seq_printf(s, | |
5a06a363 IM |
968 | "%10d %10d %4o %10lu %10lu %5u %5u %5u %5u %5u %5u %10lu %10lu %10lu\n", |
969 | msq->q_perm.key, | |
7ca7e564 | 970 | msq->q_perm.id, |
5a06a363 IM |
971 | msq->q_perm.mode, |
972 | msq->q_cbytes, | |
973 | msq->q_qnum, | |
974 | msq->q_lspid, | |
975 | msq->q_lrpid, | |
976 | msq->q_perm.uid, | |
977 | msq->q_perm.gid, | |
978 | msq->q_perm.cuid, | |
979 | msq->q_perm.cgid, | |
980 | msq->q_stime, | |
981 | msq->q_rtime, | |
982 | msq->q_ctime); | |
1da177e4 LT |
983 | } |
984 | #endif |