blob: 491e71f2a1b862a72e78a54e7b16e08812a13f3d [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,
Eric W. Biederman98f842e2011-06-15 10:21:48 -070034 .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 {
HoSung Jung1e3c9412013-04-30 19:15:09 -070040 struct msg_msgseg *next;
Linus Torvalds1da177e2005-04-16 15:20:36 -070041 /* the next part of the message follows immediately */
42};
43
Peter Hurley3d8fa452013-04-30 19:14:25 -070044#define DATALEN_MSG (int)(PAGE_SIZE-sizeof(struct msg_msg))
45#define DATALEN_SEG (int)(PAGE_SIZE-sizeof(struct msg_msgseg))
Linus Torvalds1da177e2005-04-16 15:20:36 -070046
Peter Hurleybe5f4b32013-04-30 19:14:31 -070047
48static struct msg_msg *alloc_msg(int len)
Linus Torvalds1da177e2005-04-16 15:20:36 -070049{
50 struct msg_msg *msg;
51 struct msg_msgseg **pseg;
Linus Torvalds1da177e2005-04-16 15:20:36 -070052 int alen;
53
Peter Hurley3d8fa452013-04-30 19:14:25 -070054 alen = min(len, DATALEN_MSG);
Robert P. J. Day5cbded52006-12-13 00:35:56 -080055 msg = kmalloc(sizeof(*msg) + alen, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -070056 if (msg == NULL)
Peter Hurleybe5f4b32013-04-30 19:14:31 -070057 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -070058
59 msg->next = NULL;
60 msg->security = NULL;
61
Peter Hurleybe5f4b32013-04-30 19:14:31 -070062 len -= alen;
63 pseg = &msg->next;
64 while (len > 0) {
65 struct msg_msgseg *seg;
66 alen = min(len, DATALEN_SEG);
67 seg = kmalloc(sizeof(*seg) + alen, GFP_KERNEL);
68 if (seg == NULL)
69 goto out_err;
70 *pseg = seg;
71 seg->next = NULL;
72 pseg = &seg->next;
73 len -= alen;
74 }
75
76 return msg;
77
78out_err:
79 free_msg(msg);
80 return NULL;
81}
82
83struct msg_msg *load_msg(const void __user *src, int len)
84{
85 struct msg_msg *msg;
86 struct msg_msgseg *seg;
Peter Hurley2b3097a2013-04-30 19:14:42 -070087 int err = -EFAULT;
Peter Hurleybe5f4b32013-04-30 19:14:31 -070088 int alen;
89
90 msg = alloc_msg(len);
91 if (msg == NULL)
92 return ERR_PTR(-ENOMEM);
93
94 alen = min(len, DATALEN_MSG);
Peter Hurley2b3097a2013-04-30 19:14:42 -070095 if (copy_from_user(msg + 1, src, alen))
Linus Torvalds1da177e2005-04-16 15:20:36 -070096 goto out_err;
Linus Torvalds1da177e2005-04-16 15:20:36 -070097
Peter Hurleyda085d42013-04-30 19:14:37 -070098 for (seg = msg->next; seg != NULL; seg = seg->next) {
99 len -= alen;
100 src = (char __user *)src + alen;
Peter Hurley3d8fa452013-04-30 19:14:25 -0700101 alen = min(len, DATALEN_SEG);
Peter Hurley2b3097a2013-04-30 19:14:42 -0700102 if (copy_from_user(seg + 1, src, alen))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103 goto out_err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104 }
105
106 err = security_msg_msg_alloc(msg);
107 if (err)
108 goto out_err;
109
110 return msg;
111
112out_err:
113 free_msg(msg);
114 return ERR_PTR(err);
115}
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -0800116#ifdef CONFIG_CHECKPOINT_RESTORE
117struct msg_msg *copy_msg(struct msg_msg *src, struct msg_msg *dst)
118{
119 struct msg_msgseg *dst_pseg, *src_pseg;
120 int len = src->m_ts;
121 int alen;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -0800123 BUG_ON(dst == NULL);
124 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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150int store_msg(void __user *dest, struct msg_msg *msg, int len)
151{
152 int alen;
153 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}