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