summaryrefslogtreecommitdiffstats
path: root/include/linux/ipc_namespace.h
blob: e8240cf2611ad63f427d8fe90b3fe8cbcb1fb6b0 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __IPC_NAMESPACE_H__
#define __IPC_NAMESPACE_H__

#include <linux/err.h>
#include <linux/idr.h>
#include <linux/rwsem.h>
#include <linux/notifier.h>
#include <linux/nsproxy.h>
#include <linux/ns_common.h>
#include <linux/refcount.h>
#include <linux/rhashtable-types.h>
#include <linux/sysctl.h>
#include <linux/percpu_counter.h>

struct user_namespace;

struct ipc_ids {
	int in_use;
	unsigned short seq;
	struct rw_semaphore rwsem;
	struct idr ipcs_idr;
	int max_idx;
	int last_idx;	/* For wrap around detection */
#ifdef CONFIG_CHECKPOINT_RESTORE
	int next_id;
#endif
	struct rhashtable key_ht;
};

struct ipc_namespace {
	struct ipc_ids	ids[3];

	int		sem_ctls[4];
	int		used_sems;

	unsigned int	msg_ctlmax;
	unsigned int	msg_ctlmnb;
	unsigned int	msg_ctlmni;
	struct percpu_counter percpu_msg_bytes;
	struct percpu_counter percpu_msg_hdrs;

	size_t		shm_ctlmax;
	size_t		shm_ctlall;
	unsigned long	shm_tot;
	int		shm_ctlmni;
	/*
	 * Defines whether IPC_RMID is forced for _all_ shm segments regardless
	 * of shmctl()
	 */
	int		shm_rmid_forced;

	struct notifier_block ipcns_nb;

	/* The kern_mount of the mqueuefs sb.  We take a ref on it */
	struct vfsmount	*mq_mnt;

	/* # queues in this ns, protected by mq_lock */
	unsigned int    mq_queues_count;

	/* next fields are set through sysctl */
	unsigned int    mq_queues_max;   /* initialized to DFLT_QUEUESMAX */
	unsigned int    mq_msg_max;      /* initialized to DFLT_MSGMAX */
	unsigned int    mq_msgsize_max;  /* initialized to DFLT_MSGSIZEMAX */
	unsigned int    mq_msg_default;
	unsigned int    mq_msgsize_default;

	struct ctl_table_set	mq_set;
	struct ctl_table_header	*mq_sysctls;

	struct ctl_table_set	ipc_set;
	struct ctl_table_header	*ipc_sysctls;

	/* user_ns which owns the ipc ns */
	struct user_namespace *user_ns;
	struct ucounts *ucounts;

	struct llist_node mnt_llist;

	struct ns_common ns;
} __randomize_layout;

extern struct ipc_namespace init_ipc_ns;
extern spinlock_t mq_lock;

#ifdef CONFIG_SYSVIPC
extern void shm_destroy_orphaned(struct ipc_namespace *ns);
#else /* CONFIG_SYSVIPC */
static inline void shm_destroy_orphaned(struct ipc_namespace *ns) {}
#endif /* CONFIG_SYSVIPC */

#ifdef CONFIG_POSIX_MQUEUE
extern int mq_init_ns(struct ipc_namespace *ns);
/*
 * POSIX Message Queue default values:
 *
 * MIN_*: Lowest value an admin can set the maximum unprivileged limit to
 * DFLT_*MAX: Default values for the maximum unprivileged limits
 * DFLT_{MSG,MSGSIZE}: Default values used when the user doesn't supply
 *   an attribute to the open call and the queue must be created
 * HARD_*: Highest value the maximums can be set to.  These are enforced
 *   on CAP_SYS_RESOURCE apps as well making them inviolate (so make them
 *   suitably high)
 *
 * POSIX Requirements:
 *   Per app minimum openable message queues - 8.  This does not map well
 *     to the fact that we limit the number of queues on a per namespace
 *     basis instead of a per app basis.  So, make the default high enough
 *     that no given app should have a hard time opening 8 queues.
 *   Minimum maximum for HARD_MSGMAX - 32767.  I bumped this to 65536.
 *   Minimum maximum for HARD_MSGSIZEMAX - POSIX is silent on this.  However,
 *     we have run into a situation where running applications in the wild
 *     require this to be at least 5MB, and preferably 10MB, so I set the
 *     value to 16MB in hopes that this user is the worst of the bunch and
 *     the new maximum will handle anyone else.  I may have to revisit this
 *     in the future.
 */
#define DFLT_QUEUESMAX		      256
#define MIN_MSGMAX			1
#define DFLT_MSG		       10U
#define DFLT_MSGMAX		       10
#define HARD_MSGMAX		    65536
#define MIN_MSGSIZEMAX		      128
#define DFLT_MSGSIZE		     8192U
#define DFLT_MSGSIZEMAX		     8192
#define HARD_MSGSIZEMAX	    (16*1024*1024)
#else
static inline int mq_init_ns(struct ipc_namespace *ns) { return 0; }
#endif

#if defined(CONFIG_IPC_NS)
extern struct ipc_namespace *copy_ipcs(unsigned long flags,
	struct user_namespace *user_ns, struct ipc_namespace *ns);

static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
{
	if (ns)
		refcount_inc(&ns->ns.count);
	return ns;
}

static inline struct ipc_namespace *get_ipc_ns_not_zero(struct ipc_namespace *ns)
{
	if (ns) {
		if (refcount_inc_not_zero(&ns->ns.count))
			return ns;
	}

	return NULL;
}

extern void put_ipc_ns(struct ipc_namespace *ns);
#else
static inline struct ipc_namespace *copy_ipcs(unsigned long flags,
	struct user_namespace *user_ns, struct ipc_namespace *ns)
{
	if (flags & CLONE_NEWIPC)
		return ERR_PTR(-EINVAL);

	return ns;
}

static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
{
	return ns;
}

static inline struct ipc_namespace *get_ipc_ns_not_zero(struct ipc_namespace *ns)
{
	return ns;
}

static inline void put_ipc_ns(struct ipc_namespace *ns)
{
}
#endif

#ifdef CONFIG_POSIX_MQUEUE_SYSCTL

void retire_mq_sysctls(struct ipc_namespace *ns);
bool setup_mq_sysctls(struct ipc_namespace *ns);

#else /* CONFIG_POSIX_MQUEUE_SYSCTL */

static inline void retire_mq_sysctls(struct ipc_namespace *ns)
{
}

static inline bool setup_mq_sysctls(struct ipc_namespace *ns)
{
	return true;
}

#endif /* CONFIG_POSIX_MQUEUE_SYSCTL */

#ifdef CONFIG_SYSVIPC_SYSCTL

bool setup_ipc_sysctls(struct ipc_namespace *ns);
void retire_ipc_sysctls(struct ipc_namespace *ns);

#else /* CONFIG_SYSVIPC_SYSCTL */

static inline void retire_ipc_sysctls(struct ipc_namespace *ns)
{
}

static inline bool setup_ipc_sysctls(struct ipc_namespace *ns)
{
	return true;
}

#endif /* CONFIG_SYSVIPC_SYSCTL */
#endif