blob: 93d345545f8d01e9eaaa2c720e9398293a1cca61 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
Uwe Zeisbergerf30c2262006-10-03 23:01:26 +02002 * linux/ipc/msgutil.c
Linus Torvalds1da177e2005-04-16 15:20:36 -07003 * Copyright (C) 1999, 2004 Manfred Spraul
4 *
5 * This file is released under GNU General Public Licence version 2 or
6 * (at your option) any later version.
7 *
8 * See the file COPYING for more details.
9 */
10
11#include <linux/spinlock.h>
12#include <linux/init.h>
13#include <linux/security.h>
14#include <linux/slab.h>
15#include <linux/ipc.h>
Al Viro40401532012-02-13 03:58:52 +000016#include <linux/msg.h>
Serge E. Hallyn614b84c2009-04-06 19:01:08 -070017#include <linux/ipc_namespace.h>
Al Viro40401532012-02-13 03:58:52 +000018#include <linux/utsname.h>
Eric W. Biederman80f4b772015-09-02 16:12:17 +053019#include <linux/proc_fs.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070020#include <asm/uaccess.h>
21
22#include "util.h"
23
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -070024DEFINE_SPINLOCK(mq_lock);
25
Serge E. Hallyn614b84c2009-04-06 19:01:08 -070026/*
27 * The next 2 defines are here bc this is the only file
28 * compiled when either CONFIG_SYSVIPC and CONFIG_POSIX_MQUEUE
29 * and not CONFIG_IPC_NS.
30 */
31struct ipc_namespace init_ipc_ns = {
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -070032 .count = ATOMIC_INIT(1),
Serge E. Hallynb5154982011-03-23 16:43:23 -070033 .user_ns = &init_user_ns,
Eric W. Biederman80f4b772015-09-02 16:12:17 +053034 .proc_inum = PROC_IPC_INIT_INO,
Serge E. Hallyn614b84c2009-04-06 19:01:08 -070035};
36
37atomic_t nr_ipc_ns = ATOMIC_INIT(1);
38
Linus Torvalds1da177e2005-04-16 15:20:36 -070039struct msg_msgseg {
40 struct msg_msgseg* next;
41 /* the next part of the message follows immediately */
42};
43
Mathias Krause23669f22013-11-12 15:11:47 -080044#define DATALEN_MSG ((size_t)PAGE_SIZE-sizeof(struct msg_msg))
45#define DATALEN_SEG ((size_t)PAGE_SIZE-sizeof(struct msg_msgseg))
Linus Torvalds1da177e2005-04-16 15:20:36 -070046
Mathias Krause23669f22013-11-12 15:11:47 -080047struct msg_msg *load_msg(const void __user *src, size_t len)
Linus Torvalds1da177e2005-04-16 15:20:36 -070048{
49 struct msg_msg *msg;
50 struct msg_msgseg **pseg;
51 int err;
Mathias Krause23669f22013-11-12 15:11:47 -080052 size_t alen;
Linus Torvalds1da177e2005-04-16 15:20:36 -070053
54 alen = len;
55 if (alen > DATALEN_MSG)
56 alen = DATALEN_MSG;
57
Robert P. J. Day5cbded52006-12-13 00:35:56 -080058 msg = kmalloc(sizeof(*msg) + alen, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -070059 if (msg == NULL)
60 return ERR_PTR(-ENOMEM);
61
62 msg->next = NULL;
63 msg->security = NULL;
64
65 if (copy_from_user(msg + 1, src, alen)) {
66 err = -EFAULT;
67 goto out_err;
68 }
69
70 len -= alen;
71 src = ((char __user *)src) + alen;
72 pseg = &msg->next;
73 while (len > 0) {
74 struct msg_msgseg *seg;
75 alen = len;
76 if (alen > DATALEN_SEG)
77 alen = DATALEN_SEG;
Robert P. J. Day5cbded52006-12-13 00:35:56 -080078 seg = kmalloc(sizeof(*seg) + alen,
Linus Torvalds1da177e2005-04-16 15:20:36 -070079 GFP_KERNEL);
80 if (seg == NULL) {
81 err = -ENOMEM;
82 goto out_err;
83 }
84 *pseg = seg;
85 seg->next = NULL;
86 if (copy_from_user(seg + 1, src, alen)) {
87 err = -EFAULT;
88 goto out_err;
89 }
90 pseg = &seg->next;
91 len -= alen;
92 src = ((char __user *)src) + alen;
93 }
94
95 err = security_msg_msg_alloc(msg);
96 if (err)
97 goto out_err;
98
99 return msg;
100
101out_err:
102 free_msg(msg);
103 return ERR_PTR(err);
104}
105
Mathias Krause23669f22013-11-12 15:11:47 -0800106int store_msg(void __user *dest, struct msg_msg *msg, size_t len)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107{
Mathias Krause23669f22013-11-12 15:11:47 -0800108 size_t alen;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109 struct msg_msgseg *seg;
110
111 alen = len;
112 if (alen > DATALEN_MSG)
113 alen = DATALEN_MSG;
114 if (copy_to_user(dest, msg + 1, alen))
115 return -1;
116
117 len -= alen;
118 dest = ((char __user *)dest) + alen;
119 seg = msg->next;
120 while (len > 0) {
121 alen = len;
122 if (alen > DATALEN_SEG)
123 alen = DATALEN_SEG;
124 if (copy_to_user(dest, seg + 1, alen))
125 return -1;
126 len -= alen;
127 dest = ((char __user *)dest) + alen;
128 seg = seg->next;
129 }
130 return 0;
131}
132
133void free_msg(struct msg_msg *msg)
134{
135 struct msg_msgseg *seg;
136
137 security_msg_msg_free(msg);
138
139 seg = msg->next;
140 kfree(msg);
141 while (seg != NULL) {
142 struct msg_msgseg *tmp = seg->next;
143 kfree(seg);
144 seg = tmp;
145 }
146}