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> |
5f921ae9 | 37 | #include <linux/mutex.h> |
1e786937 | 38 | #include <linux/nsproxy.h> |
5f921ae9 | 39 | |
1da177e4 LT |
40 | #include <asm/current.h> |
41 | #include <asm/uaccess.h> | |
42 | #include "util.h" | |
43 | ||
5a06a363 IM |
44 | /* |
45 | * one msg_receiver structure for each sleeping receiver: | |
46 | */ | |
1da177e4 | 47 | struct msg_receiver { |
5a06a363 IM |
48 | struct list_head r_list; |
49 | struct task_struct *r_tsk; | |
1da177e4 | 50 | |
5a06a363 IM |
51 | int r_mode; |
52 | long r_msgtype; | |
53 | long r_maxsize; | |
1da177e4 | 54 | |
80491eb9 | 55 | struct msg_msg *volatile r_msg; |
1da177e4 LT |
56 | }; |
57 | ||
58 | /* one msg_sender for each sleeping sender */ | |
59 | struct msg_sender { | |
5a06a363 IM |
60 | struct list_head list; |
61 | struct task_struct *tsk; | |
1da177e4 LT |
62 | }; |
63 | ||
64 | #define SEARCH_ANY 1 | |
65 | #define SEARCH_EQUAL 2 | |
66 | #define SEARCH_NOTEQUAL 3 | |
67 | #define SEARCH_LESSEQUAL 4 | |
68 | ||
5a06a363 IM |
69 | static atomic_t msg_bytes = ATOMIC_INIT(0); |
70 | static atomic_t msg_hdrs = ATOMIC_INIT(0); | |
1da177e4 | 71 | |
1e786937 | 72 | static struct ipc_ids init_msg_ids; |
1da177e4 | 73 | |
1e786937 | 74 | #define msg_ids(ns) (*((ns)->ids[IPC_MSG_IDS])) |
1da177e4 | 75 | |
1e786937 | 76 | #define msg_unlock(msq) ipc_unlock(&(msq)->q_perm) |
1e786937 KK |
77 | #define msg_buildid(ns, id, seq) \ |
78 | ipc_buildid(&msg_ids(ns), id, seq) | |
79 | ||
7ca7e564 | 80 | static void freeque(struct ipc_namespace *, struct msg_queue *); |
7748dbfa | 81 | static int newque(struct ipc_namespace *, struct ipc_params *); |
1da177e4 | 82 | #ifdef CONFIG_PROC_FS |
19b4946c | 83 | static int sysvipc_msg_proc_show(struct seq_file *s, void *it); |
1da177e4 LT |
84 | #endif |
85 | ||
7d69a1f4 | 86 | static void __msg_init_ns(struct ipc_namespace *ns, struct ipc_ids *ids) |
1e786937 KK |
87 | { |
88 | ns->ids[IPC_MSG_IDS] = ids; | |
89 | ns->msg_ctlmax = MSGMAX; | |
90 | ns->msg_ctlmnb = MSGMNB; | |
91 | ns->msg_ctlmni = MSGMNI; | |
7ca7e564 | 92 | ipc_init_ids(ids); |
1e786937 KK |
93 | } |
94 | ||
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; |
7ca7e564 ND |
110 | int next_id; |
111 | int total, in_use; | |
1e786937 KK |
112 | |
113 | mutex_lock(&msg_ids(ns).mutex); | |
7ca7e564 ND |
114 | |
115 | in_use = msg_ids(ns).in_use; | |
116 | ||
117 | for (total = 0, next_id = 0; total < in_use; next_id++) { | |
118 | msq = idr_find(&msg_ids(ns).ipcs_idr, next_id); | |
1e786937 KK |
119 | if (msq == NULL) |
120 | continue; | |
7ca7e564 ND |
121 | ipc_lock_by_ptr(&msq->q_perm); |
122 | freeque(ns, msq); | |
123 | total++; | |
1e786937 KK |
124 | } |
125 | mutex_unlock(&msg_ids(ns).mutex); | |
126 | ||
127 | kfree(ns->ids[IPC_MSG_IDS]); | |
128 | ns->ids[IPC_MSG_IDS] = NULL; | |
129 | } | |
1e786937 | 130 | |
5a06a363 | 131 | void __init msg_init(void) |
1da177e4 | 132 | { |
1e786937 | 133 | __msg_init_ns(&init_ipc_ns, &init_msg_ids); |
19b4946c MW |
134 | ipc_init_proc_interface("sysvipc/msg", |
135 | " key msqid perms cbytes qnum lspid lrpid uid gid cuid cgid stime rtime ctime\n", | |
1e786937 | 136 | IPC_MSG_IDS, sysvipc_msg_proc_show); |
1da177e4 LT |
137 | } |
138 | ||
023a5355 ND |
139 | static inline struct msg_queue *msg_lock(struct ipc_namespace *ns, int id) |
140 | { | |
03f02c76 ND |
141 | struct kern_ipc_perm *ipcp = ipc_lock(&msg_ids(ns), id); |
142 | ||
143 | return container_of(ipcp, struct msg_queue, q_perm); | |
023a5355 ND |
144 | } |
145 | ||
146 | static inline struct msg_queue *msg_lock_check(struct ipc_namespace *ns, | |
147 | int id) | |
148 | { | |
03f02c76 ND |
149 | struct kern_ipc_perm *ipcp = ipc_lock_check(&msg_ids(ns), id); |
150 | ||
151 | return container_of(ipcp, struct msg_queue, q_perm); | |
023a5355 ND |
152 | } |
153 | ||
7ca7e564 ND |
154 | static inline void msg_rmid(struct ipc_namespace *ns, struct msg_queue *s) |
155 | { | |
156 | ipc_rmid(&msg_ids(ns), &s->q_perm); | |
157 | } | |
158 | ||
f4566f04 ND |
159 | /** |
160 | * newque - Create a new msg queue | |
161 | * @ns: namespace | |
162 | * @params: ptr to the structure that contains the key and msgflg | |
163 | * | |
164 | * Called with msg_ids.mutex held | |
165 | */ | |
7748dbfa | 166 | static int newque(struct ipc_namespace *ns, struct ipc_params *params) |
1da177e4 | 167 | { |
1da177e4 | 168 | struct msg_queue *msq; |
5a06a363 | 169 | int id, retval; |
7748dbfa ND |
170 | key_t key = params->key; |
171 | int msgflg = params->flg; | |
1da177e4 | 172 | |
5a06a363 IM |
173 | msq = ipc_rcu_alloc(sizeof(*msq)); |
174 | if (!msq) | |
1da177e4 LT |
175 | return -ENOMEM; |
176 | ||
5a06a363 | 177 | msq->q_perm.mode = msgflg & S_IRWXUGO; |
1da177e4 LT |
178 | msq->q_perm.key = key; |
179 | ||
180 | msq->q_perm.security = NULL; | |
181 | retval = security_msg_queue_alloc(msq); | |
182 | if (retval) { | |
183 | ipc_rcu_putref(msq); | |
184 | return retval; | |
185 | } | |
186 | ||
7ca7e564 ND |
187 | /* |
188 | * ipc_addid() locks msq | |
189 | */ | |
1e786937 | 190 | id = ipc_addid(&msg_ids(ns), &msq->q_perm, ns->msg_ctlmni); |
5a06a363 | 191 | if (id == -1) { |
1da177e4 LT |
192 | security_msg_queue_free(msq); |
193 | ipc_rcu_putref(msq); | |
194 | return -ENOSPC; | |
195 | } | |
196 | ||
7ca7e564 | 197 | msq->q_perm.id = msg_buildid(ns, id, msq->q_perm.seq); |
1da177e4 LT |
198 | msq->q_stime = msq->q_rtime = 0; |
199 | msq->q_ctime = get_seconds(); | |
200 | msq->q_cbytes = msq->q_qnum = 0; | |
1e786937 | 201 | msq->q_qbytes = ns->msg_ctlmnb; |
1da177e4 LT |
202 | msq->q_lspid = msq->q_lrpid = 0; |
203 | INIT_LIST_HEAD(&msq->q_messages); | |
204 | INIT_LIST_HEAD(&msq->q_receivers); | |
205 | INIT_LIST_HEAD(&msq->q_senders); | |
7ca7e564 | 206 | |
1da177e4 LT |
207 | msg_unlock(msq); |
208 | ||
7ca7e564 | 209 | return msq->q_perm.id; |
1da177e4 LT |
210 | } |
211 | ||
5a06a363 | 212 | static inline void ss_add(struct msg_queue *msq, struct msg_sender *mss) |
1da177e4 | 213 | { |
5a06a363 IM |
214 | mss->tsk = current; |
215 | current->state = TASK_INTERRUPTIBLE; | |
216 | list_add_tail(&mss->list, &msq->q_senders); | |
1da177e4 LT |
217 | } |
218 | ||
5a06a363 | 219 | static inline void ss_del(struct msg_sender *mss) |
1da177e4 | 220 | { |
5a06a363 | 221 | if (mss->list.next != NULL) |
1da177e4 LT |
222 | list_del(&mss->list); |
223 | } | |
224 | ||
5a06a363 | 225 | static void ss_wakeup(struct list_head *h, int kill) |
1da177e4 LT |
226 | { |
227 | struct list_head *tmp; | |
228 | ||
229 | tmp = h->next; | |
230 | while (tmp != h) { | |
5a06a363 IM |
231 | struct msg_sender *mss; |
232 | ||
233 | mss = list_entry(tmp, struct msg_sender, list); | |
1da177e4 | 234 | tmp = tmp->next; |
5a06a363 IM |
235 | if (kill) |
236 | mss->list.next = NULL; | |
1da177e4 LT |
237 | wake_up_process(mss->tsk); |
238 | } | |
239 | } | |
240 | ||
5a06a363 | 241 | static void expunge_all(struct msg_queue *msq, int res) |
1da177e4 LT |
242 | { |
243 | struct list_head *tmp; | |
244 | ||
245 | tmp = msq->q_receivers.next; | |
246 | while (tmp != &msq->q_receivers) { | |
5a06a363 IM |
247 | struct msg_receiver *msr; |
248 | ||
249 | msr = list_entry(tmp, struct msg_receiver, r_list); | |
1da177e4 LT |
250 | tmp = tmp->next; |
251 | msr->r_msg = NULL; | |
252 | wake_up_process(msr->r_tsk); | |
253 | smp_mb(); | |
254 | msr->r_msg = ERR_PTR(res); | |
255 | } | |
256 | } | |
5a06a363 IM |
257 | |
258 | /* | |
259 | * freeque() wakes up waiters on the sender and receiver waiting queue, | |
f4566f04 ND |
260 | * removes the message queue from message queue ID IDR, and cleans up all the |
261 | * messages associated with this queue. | |
1da177e4 | 262 | * |
7ca7e564 | 263 | * msg_ids.mutex and the spinlock for this message queue are held |
5f921ae9 | 264 | * before freeque() is called. msg_ids.mutex remains locked on exit. |
1da177e4 | 265 | */ |
7ca7e564 | 266 | static void freeque(struct ipc_namespace *ns, struct msg_queue *msq) |
1da177e4 LT |
267 | { |
268 | struct list_head *tmp; | |
269 | ||
5a06a363 IM |
270 | expunge_all(msq, -EIDRM); |
271 | ss_wakeup(&msq->q_senders, 1); | |
7ca7e564 | 272 | msg_rmid(ns, msq); |
1da177e4 | 273 | msg_unlock(msq); |
5a06a363 | 274 | |
1da177e4 | 275 | tmp = msq->q_messages.next; |
5a06a363 IM |
276 | while (tmp != &msq->q_messages) { |
277 | struct msg_msg *msg = list_entry(tmp, struct msg_msg, m_list); | |
278 | ||
1da177e4 LT |
279 | tmp = tmp->next; |
280 | atomic_dec(&msg_hdrs); | |
281 | free_msg(msg); | |
282 | } | |
283 | atomic_sub(msq->q_cbytes, &msg_bytes); | |
284 | security_msg_queue_free(msq); | |
285 | ipc_rcu_putref(msq); | |
286 | } | |
287 | ||
f4566f04 ND |
288 | /* |
289 | * Called with msg_ids.mutex and ipcp locked. | |
290 | */ | |
03f02c76 | 291 | static inline int msg_security(struct kern_ipc_perm *ipcp, int msgflg) |
7748dbfa | 292 | { |
03f02c76 ND |
293 | struct msg_queue *msq = container_of(ipcp, struct msg_queue, q_perm); |
294 | ||
295 | return security_msg_queue_associate(msq, msgflg); | |
7748dbfa ND |
296 | } |
297 | ||
5a06a363 | 298 | asmlinkage long sys_msgget(key_t key, int msgflg) |
1da177e4 | 299 | { |
1e786937 | 300 | struct ipc_namespace *ns; |
7748dbfa ND |
301 | struct ipc_ops msg_ops; |
302 | struct ipc_params msg_params; | |
1e786937 KK |
303 | |
304 | ns = current->nsproxy->ipc_ns; | |
7ca7e564 | 305 | |
7748dbfa ND |
306 | msg_ops.getnew = newque; |
307 | msg_ops.associate = msg_security; | |
308 | msg_ops.more_checks = NULL; | |
309 | ||
310 | msg_params.key = key; | |
311 | msg_params.flg = msgflg; | |
5a06a363 | 312 | |
7748dbfa | 313 | return ipcget(ns, &msg_ids(ns), &msg_ops, &msg_params); |
1da177e4 LT |
314 | } |
315 | ||
5a06a363 IM |
316 | static inline unsigned long |
317 | copy_msqid_to_user(void __user *buf, struct msqid64_ds *in, int version) | |
1da177e4 LT |
318 | { |
319 | switch(version) { | |
320 | case IPC_64: | |
5a06a363 | 321 | return copy_to_user(buf, in, sizeof(*in)); |
1da177e4 | 322 | case IPC_OLD: |
5a06a363 | 323 | { |
1da177e4 LT |
324 | struct msqid_ds out; |
325 | ||
5a06a363 | 326 | memset(&out, 0, sizeof(out)); |
1da177e4 LT |
327 | |
328 | ipc64_perm_to_ipc_perm(&in->msg_perm, &out.msg_perm); | |
329 | ||
330 | out.msg_stime = in->msg_stime; | |
331 | out.msg_rtime = in->msg_rtime; | |
332 | out.msg_ctime = in->msg_ctime; | |
333 | ||
5a06a363 | 334 | if (in->msg_cbytes > USHRT_MAX) |
1da177e4 LT |
335 | out.msg_cbytes = USHRT_MAX; |
336 | else | |
337 | out.msg_cbytes = in->msg_cbytes; | |
338 | out.msg_lcbytes = in->msg_cbytes; | |
339 | ||
5a06a363 | 340 | if (in->msg_qnum > USHRT_MAX) |
1da177e4 LT |
341 | out.msg_qnum = USHRT_MAX; |
342 | else | |
343 | out.msg_qnum = in->msg_qnum; | |
344 | ||
5a06a363 | 345 | if (in->msg_qbytes > USHRT_MAX) |
1da177e4 LT |
346 | out.msg_qbytes = USHRT_MAX; |
347 | else | |
348 | out.msg_qbytes = in->msg_qbytes; | |
349 | out.msg_lqbytes = in->msg_qbytes; | |
350 | ||
351 | out.msg_lspid = in->msg_lspid; | |
352 | out.msg_lrpid = in->msg_lrpid; | |
353 | ||
5a06a363 IM |
354 | return copy_to_user(buf, &out, sizeof(out)); |
355 | } | |
1da177e4 LT |
356 | default: |
357 | return -EINVAL; | |
358 | } | |
359 | } | |
360 | ||
361 | struct msq_setbuf { | |
362 | unsigned long qbytes; | |
363 | uid_t uid; | |
364 | gid_t gid; | |
365 | mode_t mode; | |
366 | }; | |
367 | ||
5a06a363 IM |
368 | static inline unsigned long |
369 | copy_msqid_from_user(struct msq_setbuf *out, void __user *buf, int version) | |
1da177e4 LT |
370 | { |
371 | switch(version) { | |
372 | case IPC_64: | |
5a06a363 | 373 | { |
1da177e4 LT |
374 | struct msqid64_ds tbuf; |
375 | ||
5a06a363 | 376 | if (copy_from_user(&tbuf, buf, sizeof(tbuf))) |
1da177e4 LT |
377 | return -EFAULT; |
378 | ||
379 | out->qbytes = tbuf.msg_qbytes; | |
380 | out->uid = tbuf.msg_perm.uid; | |
381 | out->gid = tbuf.msg_perm.gid; | |
382 | out->mode = tbuf.msg_perm.mode; | |
383 | ||
384 | return 0; | |
5a06a363 | 385 | } |
1da177e4 | 386 | case IPC_OLD: |
5a06a363 | 387 | { |
1da177e4 LT |
388 | struct msqid_ds tbuf_old; |
389 | ||
5a06a363 | 390 | if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old))) |
1da177e4 LT |
391 | return -EFAULT; |
392 | ||
393 | out->uid = tbuf_old.msg_perm.uid; | |
394 | out->gid = tbuf_old.msg_perm.gid; | |
395 | out->mode = tbuf_old.msg_perm.mode; | |
396 | ||
5a06a363 | 397 | if (tbuf_old.msg_qbytes == 0) |
1da177e4 LT |
398 | out->qbytes = tbuf_old.msg_lqbytes; |
399 | else | |
400 | out->qbytes = tbuf_old.msg_qbytes; | |
401 | ||
402 | return 0; | |
5a06a363 | 403 | } |
1da177e4 LT |
404 | default: |
405 | return -EINVAL; | |
406 | } | |
407 | } | |
408 | ||
5a06a363 | 409 | asmlinkage long sys_msgctl(int msqid, int cmd, struct msqid_ds __user *buf) |
1da177e4 | 410 | { |
1da177e4 | 411 | struct kern_ipc_perm *ipcp; |
8e1c091c | 412 | struct msq_setbuf uninitialized_var(setbuf); |
5a06a363 IM |
413 | struct msg_queue *msq; |
414 | int err, version; | |
1e786937 | 415 | struct ipc_namespace *ns; |
5a06a363 | 416 | |
1da177e4 LT |
417 | if (msqid < 0 || cmd < 0) |
418 | return -EINVAL; | |
419 | ||
420 | version = ipc_parse_version(&cmd); | |
1e786937 | 421 | ns = current->nsproxy->ipc_ns; |
1da177e4 LT |
422 | |
423 | switch (cmd) { | |
5a06a363 IM |
424 | case IPC_INFO: |
425 | case MSG_INFO: | |
426 | { | |
1da177e4 LT |
427 | struct msginfo msginfo; |
428 | int max_id; | |
5a06a363 | 429 | |
1da177e4 LT |
430 | if (!buf) |
431 | return -EFAULT; | |
5a06a363 IM |
432 | /* |
433 | * We must not return kernel stack data. | |
1da177e4 LT |
434 | * due to padding, it's not enough |
435 | * to set all member fields. | |
436 | */ | |
1da177e4 LT |
437 | err = security_msg_queue_msgctl(NULL, cmd); |
438 | if (err) | |
439 | return err; | |
440 | ||
5a06a363 | 441 | memset(&msginfo, 0, sizeof(msginfo)); |
1e786937 KK |
442 | msginfo.msgmni = ns->msg_ctlmni; |
443 | msginfo.msgmax = ns->msg_ctlmax; | |
444 | msginfo.msgmnb = ns->msg_ctlmnb; | |
1da177e4 LT |
445 | msginfo.msgssz = MSGSSZ; |
446 | msginfo.msgseg = MSGSEG; | |
1e786937 | 447 | mutex_lock(&msg_ids(ns).mutex); |
1da177e4 | 448 | if (cmd == MSG_INFO) { |
1e786937 | 449 | msginfo.msgpool = msg_ids(ns).in_use; |
1da177e4 LT |
450 | msginfo.msgmap = atomic_read(&msg_hdrs); |
451 | msginfo.msgtql = atomic_read(&msg_bytes); | |
452 | } else { | |
453 | msginfo.msgmap = MSGMAP; | |
454 | msginfo.msgpool = MSGPOOL; | |
455 | msginfo.msgtql = MSGTQL; | |
456 | } | |
7ca7e564 | 457 | max_id = ipc_get_maxid(&msg_ids(ns)); |
1e786937 | 458 | mutex_unlock(&msg_ids(ns).mutex); |
5a06a363 | 459 | if (copy_to_user(buf, &msginfo, sizeof(struct msginfo))) |
1da177e4 | 460 | return -EFAULT; |
5a06a363 | 461 | return (max_id < 0) ? 0 : max_id; |
1da177e4 | 462 | } |
7ca7e564 | 463 | case MSG_STAT: /* msqid is an index rather than a msg queue id */ |
1da177e4 LT |
464 | case IPC_STAT: |
465 | { | |
466 | struct msqid64_ds tbuf; | |
467 | int success_return; | |
5a06a363 | 468 | |
1da177e4 LT |
469 | if (!buf) |
470 | return -EFAULT; | |
1da177e4 | 471 | |
5a06a363 | 472 | if (cmd == MSG_STAT) { |
023a5355 ND |
473 | msq = msg_lock(ns, msqid); |
474 | if (IS_ERR(msq)) | |
475 | return PTR_ERR(msq); | |
7ca7e564 | 476 | success_return = msq->q_perm.id; |
1da177e4 | 477 | } else { |
023a5355 ND |
478 | msq = msg_lock_check(ns, msqid); |
479 | if (IS_ERR(msq)) | |
480 | return PTR_ERR(msq); | |
1da177e4 LT |
481 | success_return = 0; |
482 | } | |
483 | err = -EACCES; | |
5a06a363 | 484 | if (ipcperms(&msq->q_perm, S_IRUGO)) |
1da177e4 LT |
485 | goto out_unlock; |
486 | ||
487 | err = security_msg_queue_msgctl(msq, cmd); | |
488 | if (err) | |
489 | goto out_unlock; | |
490 | ||
023a5355 ND |
491 | memset(&tbuf, 0, sizeof(tbuf)); |
492 | ||
1da177e4 LT |
493 | kernel_to_ipc64_perm(&msq->q_perm, &tbuf.msg_perm); |
494 | tbuf.msg_stime = msq->q_stime; | |
495 | tbuf.msg_rtime = msq->q_rtime; | |
496 | tbuf.msg_ctime = msq->q_ctime; | |
497 | tbuf.msg_cbytes = msq->q_cbytes; | |
498 | tbuf.msg_qnum = msq->q_qnum; | |
499 | tbuf.msg_qbytes = msq->q_qbytes; | |
500 | tbuf.msg_lspid = msq->q_lspid; | |
501 | tbuf.msg_lrpid = msq->q_lrpid; | |
502 | msg_unlock(msq); | |
503 | if (copy_msqid_to_user(buf, &tbuf, version)) | |
504 | return -EFAULT; | |
505 | return success_return; | |
506 | } | |
507 | case IPC_SET: | |
508 | if (!buf) | |
509 | return -EFAULT; | |
5a06a363 | 510 | if (copy_msqid_from_user(&setbuf, buf, version)) |
1da177e4 | 511 | return -EFAULT; |
1da177e4 LT |
512 | break; |
513 | case IPC_RMID: | |
514 | break; | |
515 | default: | |
516 | return -EINVAL; | |
517 | } | |
518 | ||
1e786937 | 519 | mutex_lock(&msg_ids(ns).mutex); |
023a5355 ND |
520 | msq = msg_lock_check(ns, msqid); |
521 | if (IS_ERR(msq)) { | |
522 | err = PTR_ERR(msq); | |
1da177e4 | 523 | goto out_up; |
023a5355 | 524 | } |
1da177e4 | 525 | |
1da177e4 | 526 | ipcp = &msq->q_perm; |
073115d6 SG |
527 | |
528 | err = audit_ipc_obj(ipcp); | |
529 | if (err) | |
530 | goto out_unlock_up; | |
8e1c091c | 531 | if (cmd == IPC_SET) { |
5a06a363 IM |
532 | err = audit_ipc_set_perm(setbuf.qbytes, setbuf.uid, setbuf.gid, |
533 | setbuf.mode); | |
ac03221a LK |
534 | if (err) |
535 | goto out_unlock_up; | |
536 | } | |
073115d6 | 537 | |
1da177e4 | 538 | err = -EPERM; |
5a06a363 | 539 | if (current->euid != ipcp->cuid && |
1da177e4 | 540 | current->euid != ipcp->uid && !capable(CAP_SYS_ADMIN)) |
5a06a363 | 541 | /* We _could_ check for CAP_CHOWN above, but we don't */ |
1da177e4 LT |
542 | goto out_unlock_up; |
543 | ||
544 | err = security_msg_queue_msgctl(msq, cmd); | |
545 | if (err) | |
546 | goto out_unlock_up; | |
547 | ||
548 | switch (cmd) { | |
549 | case IPC_SET: | |
550 | { | |
551 | err = -EPERM; | |
1e786937 | 552 | if (setbuf.qbytes > ns->msg_ctlmnb && !capable(CAP_SYS_RESOURCE)) |
1da177e4 LT |
553 | goto out_unlock_up; |
554 | ||
555 | msq->q_qbytes = setbuf.qbytes; | |
556 | ||
557 | ipcp->uid = setbuf.uid; | |
558 | ipcp->gid = setbuf.gid; | |
5a06a363 IM |
559 | ipcp->mode = (ipcp->mode & ~S_IRWXUGO) | |
560 | (S_IRWXUGO & setbuf.mode); | |
1da177e4 LT |
561 | msq->q_ctime = get_seconds(); |
562 | /* sleeping receivers might be excluded by | |
563 | * stricter permissions. | |
564 | */ | |
5a06a363 | 565 | expunge_all(msq, -EAGAIN); |
1da177e4 LT |
566 | /* sleeping senders might be able to send |
567 | * due to a larger queue size. | |
568 | */ | |
5a06a363 | 569 | ss_wakeup(&msq->q_senders, 0); |
1da177e4 LT |
570 | msg_unlock(msq); |
571 | break; | |
572 | } | |
573 | case IPC_RMID: | |
7ca7e564 | 574 | freeque(ns, msq); |
1da177e4 LT |
575 | break; |
576 | } | |
577 | err = 0; | |
578 | out_up: | |
1e786937 | 579 | mutex_unlock(&msg_ids(ns).mutex); |
1da177e4 LT |
580 | return err; |
581 | out_unlock_up: | |
582 | msg_unlock(msq); | |
583 | goto out_up; | |
584 | out_unlock: | |
585 | msg_unlock(msq); | |
586 | return err; | |
587 | } | |
588 | ||
5a06a363 | 589 | static int testmsg(struct msg_msg *msg, long type, int mode) |
1da177e4 LT |
590 | { |
591 | switch(mode) | |
592 | { | |
593 | case SEARCH_ANY: | |
594 | return 1; | |
595 | case SEARCH_LESSEQUAL: | |
5a06a363 | 596 | if (msg->m_type <=type) |
1da177e4 LT |
597 | return 1; |
598 | break; | |
599 | case SEARCH_EQUAL: | |
5a06a363 | 600 | if (msg->m_type == type) |
1da177e4 LT |
601 | return 1; |
602 | break; | |
603 | case SEARCH_NOTEQUAL: | |
5a06a363 | 604 | if (msg->m_type != type) |
1da177e4 LT |
605 | return 1; |
606 | break; | |
607 | } | |
608 | return 0; | |
609 | } | |
610 | ||
5a06a363 | 611 | static inline int pipelined_send(struct msg_queue *msq, struct msg_msg *msg) |
1da177e4 | 612 | { |
5a06a363 | 613 | struct list_head *tmp; |
1da177e4 LT |
614 | |
615 | tmp = msq->q_receivers.next; | |
616 | while (tmp != &msq->q_receivers) { | |
5a06a363 IM |
617 | struct msg_receiver *msr; |
618 | ||
619 | msr = list_entry(tmp, struct msg_receiver, r_list); | |
1da177e4 | 620 | tmp = tmp->next; |
5a06a363 IM |
621 | if (testmsg(msg, msr->r_msgtype, msr->r_mode) && |
622 | !security_msg_queue_msgrcv(msq, msg, msr->r_tsk, | |
623 | msr->r_msgtype, msr->r_mode)) { | |
624 | ||
1da177e4 | 625 | list_del(&msr->r_list); |
5a06a363 | 626 | if (msr->r_maxsize < msg->m_ts) { |
1da177e4 LT |
627 | msr->r_msg = NULL; |
628 | wake_up_process(msr->r_tsk); | |
629 | smp_mb(); | |
630 | msr->r_msg = ERR_PTR(-E2BIG); | |
631 | } else { | |
632 | msr->r_msg = NULL; | |
b488893a | 633 | msq->q_lrpid = task_pid_vnr(msr->r_tsk); |
1da177e4 LT |
634 | msq->q_rtime = get_seconds(); |
635 | wake_up_process(msr->r_tsk); | |
636 | smp_mb(); | |
637 | msr->r_msg = msg; | |
5a06a363 | 638 | |
1da177e4 LT |
639 | return 1; |
640 | } | |
641 | } | |
642 | } | |
643 | return 0; | |
644 | } | |
645 | ||
651971cb | 646 | long do_msgsnd(int msqid, long mtype, void __user *mtext, |
647 | size_t msgsz, int msgflg) | |
1da177e4 LT |
648 | { |
649 | struct msg_queue *msq; | |
650 | struct msg_msg *msg; | |
1da177e4 | 651 | int err; |
1e786937 KK |
652 | struct ipc_namespace *ns; |
653 | ||
654 | ns = current->nsproxy->ipc_ns; | |
5a06a363 | 655 | |
1e786937 | 656 | if (msgsz > ns->msg_ctlmax || (long) msgsz < 0 || msqid < 0) |
1da177e4 | 657 | return -EINVAL; |
1da177e4 LT |
658 | if (mtype < 1) |
659 | return -EINVAL; | |
660 | ||
651971cb | 661 | msg = load_msg(mtext, msgsz); |
5a06a363 | 662 | if (IS_ERR(msg)) |
1da177e4 LT |
663 | return PTR_ERR(msg); |
664 | ||
665 | msg->m_type = mtype; | |
666 | msg->m_ts = msgsz; | |
667 | ||
023a5355 ND |
668 | msq = msg_lock_check(ns, msqid); |
669 | if (IS_ERR(msq)) { | |
670 | err = PTR_ERR(msq); | |
1da177e4 | 671 | goto out_free; |
023a5355 | 672 | } |
1da177e4 LT |
673 | |
674 | for (;;) { | |
675 | struct msg_sender s; | |
676 | ||
5a06a363 | 677 | err = -EACCES; |
1da177e4 LT |
678 | if (ipcperms(&msq->q_perm, S_IWUGO)) |
679 | goto out_unlock_free; | |
680 | ||
681 | err = security_msg_queue_msgsnd(msq, msg, msgflg); | |
682 | if (err) | |
683 | goto out_unlock_free; | |
684 | ||
5a06a363 | 685 | if (msgsz + msq->q_cbytes <= msq->q_qbytes && |
1da177e4 LT |
686 | 1 + msq->q_qnum <= msq->q_qbytes) { |
687 | break; | |
688 | } | |
689 | ||
690 | /* queue full, wait: */ | |
5a06a363 IM |
691 | if (msgflg & IPC_NOWAIT) { |
692 | err = -EAGAIN; | |
1da177e4 LT |
693 | goto out_unlock_free; |
694 | } | |
695 | ss_add(msq, &s); | |
696 | ipc_rcu_getref(msq); | |
697 | msg_unlock(msq); | |
698 | schedule(); | |
699 | ||
700 | ipc_lock_by_ptr(&msq->q_perm); | |
701 | ipc_rcu_putref(msq); | |
702 | if (msq->q_perm.deleted) { | |
703 | err = -EIDRM; | |
704 | goto out_unlock_free; | |
705 | } | |
706 | ss_del(&s); | |
5a06a363 | 707 | |
1da177e4 | 708 | if (signal_pending(current)) { |
5a06a363 | 709 | err = -ERESTARTNOHAND; |
1da177e4 LT |
710 | goto out_unlock_free; |
711 | } | |
712 | } | |
713 | ||
b488893a | 714 | msq->q_lspid = task_tgid_vnr(current); |
1da177e4 LT |
715 | msq->q_stime = get_seconds(); |
716 | ||
5a06a363 | 717 | if (!pipelined_send(msq, msg)) { |
1da177e4 | 718 | /* noone is waiting for this message, enqueue it */ |
5a06a363 | 719 | list_add_tail(&msg->m_list, &msq->q_messages); |
1da177e4 LT |
720 | msq->q_cbytes += msgsz; |
721 | msq->q_qnum++; | |
5a06a363 | 722 | atomic_add(msgsz, &msg_bytes); |
1da177e4 LT |
723 | atomic_inc(&msg_hdrs); |
724 | } | |
5a06a363 | 725 | |
1da177e4 LT |
726 | err = 0; |
727 | msg = NULL; | |
728 | ||
729 | out_unlock_free: | |
730 | msg_unlock(msq); | |
731 | out_free: | |
5a06a363 | 732 | if (msg != NULL) |
1da177e4 LT |
733 | free_msg(msg); |
734 | return err; | |
735 | } | |
736 | ||
651971cb | 737 | asmlinkage long |
738 | sys_msgsnd(int msqid, struct msgbuf __user *msgp, size_t msgsz, int msgflg) | |
739 | { | |
740 | long mtype; | |
741 | ||
742 | if (get_user(mtype, &msgp->mtype)) | |
743 | return -EFAULT; | |
744 | return do_msgsnd(msqid, mtype, msgp->mtext, msgsz, msgflg); | |
745 | } | |
746 | ||
5a06a363 | 747 | static inline int convert_mode(long *msgtyp, int msgflg) |
1da177e4 | 748 | { |
5a06a363 | 749 | /* |
1da177e4 LT |
750 | * find message of correct type. |
751 | * msgtyp = 0 => get first. | |
752 | * msgtyp > 0 => get first message of matching type. | |
5a06a363 | 753 | * msgtyp < 0 => get message with least type must be < abs(msgtype). |
1da177e4 | 754 | */ |
5a06a363 | 755 | if (*msgtyp == 0) |
1da177e4 | 756 | return SEARCH_ANY; |
5a06a363 IM |
757 | if (*msgtyp < 0) { |
758 | *msgtyp = -*msgtyp; | |
1da177e4 LT |
759 | return SEARCH_LESSEQUAL; |
760 | } | |
5a06a363 | 761 | if (msgflg & MSG_EXCEPT) |
1da177e4 LT |
762 | return SEARCH_NOTEQUAL; |
763 | return SEARCH_EQUAL; | |
764 | } | |
765 | ||
651971cb | 766 | long do_msgrcv(int msqid, long *pmtype, void __user *mtext, |
767 | size_t msgsz, long msgtyp, int msgflg) | |
1da177e4 LT |
768 | { |
769 | struct msg_queue *msq; | |
770 | struct msg_msg *msg; | |
771 | int mode; | |
1e786937 | 772 | struct ipc_namespace *ns; |
1da177e4 LT |
773 | |
774 | if (msqid < 0 || (long) msgsz < 0) | |
775 | return -EINVAL; | |
5a06a363 | 776 | mode = convert_mode(&msgtyp, msgflg); |
1e786937 | 777 | ns = current->nsproxy->ipc_ns; |
1da177e4 | 778 | |
023a5355 ND |
779 | msq = msg_lock_check(ns, msqid); |
780 | if (IS_ERR(msq)) | |
781 | return PTR_ERR(msq); | |
1da177e4 LT |
782 | |
783 | for (;;) { | |
784 | struct msg_receiver msr_d; | |
5a06a363 | 785 | struct list_head *tmp; |
1da177e4 LT |
786 | |
787 | msg = ERR_PTR(-EACCES); | |
5a06a363 | 788 | if (ipcperms(&msq->q_perm, S_IRUGO)) |
1da177e4 LT |
789 | goto out_unlock; |
790 | ||
791 | msg = ERR_PTR(-EAGAIN); | |
792 | tmp = msq->q_messages.next; | |
793 | while (tmp != &msq->q_messages) { | |
794 | struct msg_msg *walk_msg; | |
5a06a363 IM |
795 | |
796 | walk_msg = list_entry(tmp, struct msg_msg, m_list); | |
797 | if (testmsg(walk_msg, msgtyp, mode) && | |
798 | !security_msg_queue_msgrcv(msq, walk_msg, current, | |
799 | msgtyp, mode)) { | |
800 | ||
1da177e4 | 801 | msg = walk_msg; |
5a06a363 IM |
802 | if (mode == SEARCH_LESSEQUAL && |
803 | walk_msg->m_type != 1) { | |
804 | msg = walk_msg; | |
805 | msgtyp = walk_msg->m_type - 1; | |
1da177e4 | 806 | } else { |
5a06a363 | 807 | msg = walk_msg; |
1da177e4 LT |
808 | break; |
809 | } | |
810 | } | |
811 | tmp = tmp->next; | |
812 | } | |
5a06a363 IM |
813 | if (!IS_ERR(msg)) { |
814 | /* | |
815 | * Found a suitable message. | |
816 | * Unlink it from the queue. | |
817 | */ | |
1da177e4 LT |
818 | if ((msgsz < msg->m_ts) && !(msgflg & MSG_NOERROR)) { |
819 | msg = ERR_PTR(-E2BIG); | |
820 | goto out_unlock; | |
821 | } | |
822 | list_del(&msg->m_list); | |
823 | msq->q_qnum--; | |
824 | msq->q_rtime = get_seconds(); | |
b488893a | 825 | msq->q_lrpid = task_tgid_vnr(current); |
1da177e4 | 826 | msq->q_cbytes -= msg->m_ts; |
5a06a363 | 827 | atomic_sub(msg->m_ts, &msg_bytes); |
1da177e4 | 828 | atomic_dec(&msg_hdrs); |
5a06a363 | 829 | ss_wakeup(&msq->q_senders, 0); |
1da177e4 LT |
830 | msg_unlock(msq); |
831 | break; | |
832 | } | |
833 | /* No message waiting. Wait for a message */ | |
834 | if (msgflg & IPC_NOWAIT) { | |
835 | msg = ERR_PTR(-ENOMSG); | |
836 | goto out_unlock; | |
837 | } | |
5a06a363 | 838 | list_add_tail(&msr_d.r_list, &msq->q_receivers); |
1da177e4 LT |
839 | msr_d.r_tsk = current; |
840 | msr_d.r_msgtype = msgtyp; | |
841 | msr_d.r_mode = mode; | |
5a06a363 | 842 | if (msgflg & MSG_NOERROR) |
1da177e4 | 843 | msr_d.r_maxsize = INT_MAX; |
5a06a363 | 844 | else |
1da177e4 LT |
845 | msr_d.r_maxsize = msgsz; |
846 | msr_d.r_msg = ERR_PTR(-EAGAIN); | |
847 | current->state = TASK_INTERRUPTIBLE; | |
848 | msg_unlock(msq); | |
849 | ||
850 | schedule(); | |
851 | ||
852 | /* Lockless receive, part 1: | |
853 | * Disable preemption. We don't hold a reference to the queue | |
854 | * and getting a reference would defeat the idea of a lockless | |
855 | * operation, thus the code relies on rcu to guarantee the | |
856 | * existance of msq: | |
857 | * Prior to destruction, expunge_all(-EIRDM) changes r_msg. | |
858 | * Thus if r_msg is -EAGAIN, then the queue not yet destroyed. | |
859 | * rcu_read_lock() prevents preemption between reading r_msg | |
860 | * and the spin_lock() inside ipc_lock_by_ptr(). | |
861 | */ | |
862 | rcu_read_lock(); | |
863 | ||
864 | /* Lockless receive, part 2: | |
865 | * Wait until pipelined_send or expunge_all are outside of | |
866 | * wake_up_process(). There is a race with exit(), see | |
867 | * ipc/mqueue.c for the details. | |
868 | */ | |
5a06a363 | 869 | msg = (struct msg_msg*)msr_d.r_msg; |
1da177e4 LT |
870 | while (msg == NULL) { |
871 | cpu_relax(); | |
5a06a363 | 872 | msg = (struct msg_msg *)msr_d.r_msg; |
1da177e4 LT |
873 | } |
874 | ||
875 | /* Lockless receive, part 3: | |
876 | * If there is a message or an error then accept it without | |
877 | * locking. | |
878 | */ | |
5a06a363 | 879 | if (msg != ERR_PTR(-EAGAIN)) { |
1da177e4 LT |
880 | rcu_read_unlock(); |
881 | break; | |
882 | } | |
883 | ||
884 | /* Lockless receive, part 3: | |
885 | * Acquire the queue spinlock. | |
886 | */ | |
887 | ipc_lock_by_ptr(&msq->q_perm); | |
888 | rcu_read_unlock(); | |
889 | ||
890 | /* Lockless receive, part 4: | |
891 | * Repeat test after acquiring the spinlock. | |
892 | */ | |
893 | msg = (struct msg_msg*)msr_d.r_msg; | |
5a06a363 | 894 | if (msg != ERR_PTR(-EAGAIN)) |
1da177e4 LT |
895 | goto out_unlock; |
896 | ||
897 | list_del(&msr_d.r_list); | |
898 | if (signal_pending(current)) { | |
899 | msg = ERR_PTR(-ERESTARTNOHAND); | |
900 | out_unlock: | |
901 | msg_unlock(msq); | |
902 | break; | |
903 | } | |
904 | } | |
905 | if (IS_ERR(msg)) | |
5a06a363 | 906 | return PTR_ERR(msg); |
1da177e4 LT |
907 | |
908 | msgsz = (msgsz > msg->m_ts) ? msg->m_ts : msgsz; | |
651971cb | 909 | *pmtype = msg->m_type; |
910 | if (store_msg(mtext, msg, msgsz)) | |
5a06a363 | 911 | msgsz = -EFAULT; |
651971cb | 912 | |
1da177e4 | 913 | free_msg(msg); |
5a06a363 | 914 | |
1da177e4 LT |
915 | return msgsz; |
916 | } | |
917 | ||
651971cb | 918 | asmlinkage long sys_msgrcv(int msqid, struct msgbuf __user *msgp, size_t msgsz, |
919 | long msgtyp, int msgflg) | |
920 | { | |
921 | long err, mtype; | |
922 | ||
923 | err = do_msgrcv(msqid, &mtype, msgp->mtext, msgsz, msgtyp, msgflg); | |
924 | if (err < 0) | |
925 | goto out; | |
926 | ||
927 | if (put_user(mtype, &msgp->mtype)) | |
928 | err = -EFAULT; | |
929 | out: | |
930 | return err; | |
931 | } | |
932 | ||
1da177e4 | 933 | #ifdef CONFIG_PROC_FS |
19b4946c | 934 | static int sysvipc_msg_proc_show(struct seq_file *s, void *it) |
1da177e4 | 935 | { |
19b4946c MW |
936 | struct msg_queue *msq = it; |
937 | ||
938 | return seq_printf(s, | |
5a06a363 IM |
939 | "%10d %10d %4o %10lu %10lu %5u %5u %5u %5u %5u %5u %10lu %10lu %10lu\n", |
940 | msq->q_perm.key, | |
7ca7e564 | 941 | msq->q_perm.id, |
5a06a363 IM |
942 | msq->q_perm.mode, |
943 | msq->q_cbytes, | |
944 | msq->q_qnum, | |
945 | msq->q_lspid, | |
946 | msq->q_lrpid, | |
947 | msq->q_perm.uid, | |
948 | msq->q_perm.gid, | |
949 | msq->q_perm.cuid, | |
950 | msq->q_perm.cgid, | |
951 | msq->q_stime, | |
952 | msq->q_rtime, | |
953 | msq->q_ctime); | |
1da177e4 LT |
954 | } |
955 | #endif |