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