blob: a521999de4f103954e40db932e8903f3ed7e48f1 [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>
David Howells0bb80f22013-04-12 01:50:06 +010019#include <linux/proc_ns.h>
HoSung Jung1e3c9412013-04-30 19:15:09 -070020#include <linux/uaccess.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070021
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,
Al Viro435d5f42014-10-31 22:56:04 -040034 .ns.inum = PROC_IPC_INIT_INO,
Al Viro33c42942014-11-01 02:32:53 -040035#ifdef CONFIG_IPC_NS
36 .ns.ops = &ipcns_operations,
37#endif
Serge E. Hallyn614b84c2009-04-06 19:01:08 -070038};
39
Linus Torvalds1da177e2005-04-16 15:20:36 -070040struct msg_msgseg {
HoSung Jung1e3c9412013-04-30 19:15:09 -070041 struct msg_msgseg *next;
Linus Torvalds1da177e2005-04-16 15:20:36 -070042 /* the next part of the message follows immediately */
43};
44
Mathias Krause4e9b45a2013-11-12 15:11:47 -080045#define DATALEN_MSG ((size_t)PAGE_SIZE-sizeof(struct msg_msg))
46#define DATALEN_SEG ((size_t)PAGE_SIZE-sizeof(struct msg_msgseg))
Linus Torvalds1da177e2005-04-16 15:20:36 -070047
Peter Hurleybe5f4b32013-04-30 19:14:31 -070048
Mathias Krause4e9b45a2013-11-12 15:11:47 -080049static struct msg_msg *alloc_msg(size_t len)
Linus Torvalds1da177e2005-04-16 15:20:36 -070050{
51 struct msg_msg *msg;
52 struct msg_msgseg **pseg;
Mathias Krause4e9b45a2013-11-12 15:11:47 -080053 size_t alen;
Linus Torvalds1da177e2005-04-16 15:20:36 -070054
Peter Hurley3d8fa452013-04-30 19:14:25 -070055 alen = min(len, DATALEN_MSG);
Robert P. J. Day5cbded52006-12-13 00:35:56 -080056 msg = kmalloc(sizeof(*msg) + alen, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -070057 if (msg == NULL)
Peter Hurleybe5f4b32013-04-30 19:14:31 -070058 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -070059
60 msg->next = NULL;
61 msg->security = NULL;
62
Peter Hurleybe5f4b32013-04-30 19:14:31 -070063 len -= alen;
64 pseg = &msg->next;
65 while (len > 0) {
66 struct msg_msgseg *seg;
67 alen = min(len, DATALEN_SEG);
68 seg = kmalloc(sizeof(*seg) + alen, GFP_KERNEL);
69 if (seg == NULL)
70 goto out_err;
71 *pseg = seg;
72 seg->next = NULL;
73 pseg = &seg->next;
74 len -= alen;
75 }
76
77 return msg;
78
79out_err:
80 free_msg(msg);
81 return NULL;
82}
83
Mathias Krause4e9b45a2013-11-12 15:11:47 -080084struct msg_msg *load_msg(const void __user *src, size_t len)
Peter Hurleybe5f4b32013-04-30 19:14:31 -070085{
86 struct msg_msg *msg;
87 struct msg_msgseg *seg;
Peter Hurley2b3097a2013-04-30 19:14:42 -070088 int err = -EFAULT;
Mathias Krause4e9b45a2013-11-12 15:11:47 -080089 size_t alen;
Peter Hurleybe5f4b32013-04-30 19:14:31 -070090
91 msg = alloc_msg(len);
92 if (msg == NULL)
93 return ERR_PTR(-ENOMEM);
94
95 alen = min(len, DATALEN_MSG);
Peter Hurley2b3097a2013-04-30 19:14:42 -070096 if (copy_from_user(msg + 1, src, alen))
Linus Torvalds1da177e2005-04-16 15:20:36 -070097 goto out_err;
Linus Torvalds1da177e2005-04-16 15:20:36 -070098
Peter Hurleyda085d42013-04-30 19:14:37 -070099 for (seg = msg->next; seg != NULL; seg = seg->next) {
100 len -= alen;
101 src = (char __user *)src + alen;
Peter Hurley3d8fa452013-04-30 19:14:25 -0700102 alen = min(len, DATALEN_SEG);
Peter Hurley2b3097a2013-04-30 19:14:42 -0700103 if (copy_from_user(seg + 1, src, alen))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104 goto out_err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700105 }
106
107 err = security_msg_msg_alloc(msg);
108 if (err)
109 goto out_err;
110
111 return msg;
112
113out_err:
114 free_msg(msg);
115 return ERR_PTR(err);
116}
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -0800117#ifdef CONFIG_CHECKPOINT_RESTORE
118struct msg_msg *copy_msg(struct msg_msg *src, struct msg_msg *dst)
119{
120 struct msg_msgseg *dst_pseg, *src_pseg;
Mathias Krause4e9b45a2013-11-12 15:11:47 -0800121 size_t len = src->m_ts;
122 size_t alen;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -0800124 if (src->m_ts > dst->m_ts)
125 return ERR_PTR(-EINVAL);
126
Peter Hurley3d8fa452013-04-30 19:14:25 -0700127 alen = min(len, DATALEN_MSG);
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -0800128 memcpy(dst + 1, src + 1, alen);
129
Peter Hurleyda085d42013-04-30 19:14:37 -0700130 for (dst_pseg = dst->next, src_pseg = src->next;
131 src_pseg != NULL;
132 dst_pseg = dst_pseg->next, src_pseg = src_pseg->next) {
133
134 len -= alen;
Peter Hurley3d8fa452013-04-30 19:14:25 -0700135 alen = min(len, DATALEN_SEG);
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -0800136 memcpy(dst_pseg + 1, src_pseg + 1, alen);
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -0800137 }
138
139 dst->m_type = src->m_type;
140 dst->m_ts = src->m_ts;
141
142 return dst;
143}
Stanislav Kinsbursky51eeaca2013-01-04 15:35:01 -0800144#else
145struct msg_msg *copy_msg(struct msg_msg *src, struct msg_msg *dst)
146{
147 return ERR_PTR(-ENOSYS);
148}
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -0800149#endif
Mathias Krause4e9b45a2013-11-12 15:11:47 -0800150int store_msg(void __user *dest, struct msg_msg *msg, size_t len)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151{
Mathias Krause4e9b45a2013-11-12 15:11:47 -0800152 size_t alen;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153 struct msg_msgseg *seg;
154
Peter Hurley3d8fa452013-04-30 19:14:25 -0700155 alen = min(len, DATALEN_MSG);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700156 if (copy_to_user(dest, msg + 1, alen))
157 return -1;
158
Peter Hurleyda085d42013-04-30 19:14:37 -0700159 for (seg = msg->next; seg != NULL; seg = seg->next) {
160 len -= alen;
161 dest = (char __user *)dest + alen;
Peter Hurley3d8fa452013-04-30 19:14:25 -0700162 alen = min(len, DATALEN_SEG);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163 if (copy_to_user(dest, seg + 1, alen))
164 return -1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700165 }
166 return 0;
167}
168
169void free_msg(struct msg_msg *msg)
170{
171 struct msg_msgseg *seg;
172
173 security_msg_msg_free(msg);
174
175 seg = msg->next;
176 kfree(msg);
177 while (seg != NULL) {
178 struct msg_msgseg *tmp = seg->next;
179 kfree(seg);
180 seg = tmp;
181 }
182}