1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef __IPC_NAMESPACE_H__
3#define __IPC_NAMESPACE_H__
4
5#include <linux/err.h>
6#include <linux/idr.h>
7#include <linux/rwsem.h>
8#include <linux/notifier.h>
9#include <linux/nsproxy.h>
10#include <linux/ns_common.h>
11#include <linux/refcount.h>
12#include <linux/rhashtable-types.h>
13#include <linux/sysctl.h>
14
15struct user_namespace;
16
17struct ipc_ids {
18	int in_use;
19	unsigned short seq;
20	struct rw_semaphore rwsem;
21	struct idr ipcs_idr;
22	int max_idx;
23	int last_idx;	/* For wrap around detection */
24#ifdef CONFIG_CHECKPOINT_RESTORE
25	int next_id;
26#endif
27	struct rhashtable key_ht;
28};
29
30struct ipc_namespace {
31	struct ipc_ids	ids[3];
32
33	int		sem_ctls[4];
34	int		used_sems;
35
36	unsigned int	msg_ctlmax;
37	unsigned int	msg_ctlmnb;
38	unsigned int	msg_ctlmni;
39	atomic_t	msg_bytes;
40	atomic_t	msg_hdrs;
41
42	size_t		shm_ctlmax;
43	size_t		shm_ctlall;
44	unsigned long	shm_tot;
45	int		shm_ctlmni;
46	/*
47	 * Defines whether IPC_RMID is forced for _all_ shm segments regardless
48	 * of shmctl()
49	 */
50	int		shm_rmid_forced;
51
52	struct notifier_block ipcns_nb;
53
54	/* The kern_mount of the mqueuefs sb.  We take a ref on it */
55	struct vfsmount	*mq_mnt;
56
57	/* # queues in this ns, protected by mq_lock */
58	unsigned int    mq_queues_count;
59
60	/* next fields are set through sysctl */
61	unsigned int    mq_queues_max;   /* initialized to DFLT_QUEUESMAX */
62	unsigned int    mq_msg_max;      /* initialized to DFLT_MSGMAX */
63	unsigned int    mq_msgsize_max;  /* initialized to DFLT_MSGSIZEMAX */
64	unsigned int    mq_msg_default;
65	unsigned int    mq_msgsize_default;
66
67	struct ctl_table_set	mq_set;
68	struct ctl_table_header	*mq_sysctls;
69
70	struct ctl_table_set	ipc_set;
71	struct ctl_table_header	*ipc_sysctls;
72
73	/* user_ns which owns the ipc ns */
74	struct user_namespace *user_ns;
75	struct ucounts *ucounts;
76
77	struct llist_node mnt_llist;
78
79	struct ns_common ns;
80} __randomize_layout;
81
82extern struct ipc_namespace init_ipc_ns;
83extern spinlock_t mq_lock;
84
85#ifdef CONFIG_SYSVIPC
86extern void shm_destroy_orphaned(struct ipc_namespace *ns);
87#else /* CONFIG_SYSVIPC */
88static inline void shm_destroy_orphaned(struct ipc_namespace *ns) {}
89#endif /* CONFIG_SYSVIPC */
90
91#ifdef CONFIG_POSIX_MQUEUE
92extern int mq_init_ns(struct ipc_namespace *ns);
93/*
94 * POSIX Message Queue default values:
95 *
96 * MIN_*: Lowest value an admin can set the maximum unprivileged limit to
97 * DFLT_*MAX: Default values for the maximum unprivileged limits
98 * DFLT_{MSG,MSGSIZE}: Default values used when the user doesn't supply
99 *   an attribute to the open call and the queue must be created
100 * HARD_*: Highest value the maximums can be set to.  These are enforced
101 *   on CAP_SYS_RESOURCE apps as well making them inviolate (so make them
102 *   suitably high)
103 *
104 * POSIX Requirements:
105 *   Per app minimum openable message queues - 8.  This does not map well
106 *     to the fact that we limit the number of queues on a per namespace
107 *     basis instead of a per app basis.  So, make the default high enough
108 *     that no given app should have a hard time opening 8 queues.
109 *   Minimum maximum for HARD_MSGMAX - 32767.  I bumped this to 65536.
110 *   Minimum maximum for HARD_MSGSIZEMAX - POSIX is silent on this.  However,
111 *     we have run into a situation where running applications in the wild
112 *     require this to be at least 5MB, and preferably 10MB, so I set the
113 *     value to 16MB in hopes that this user is the worst of the bunch and
114 *     the new maximum will handle anyone else.  I may have to revisit this
115 *     in the future.
116 */
117#define DFLT_QUEUESMAX		      256
118#define MIN_MSGMAX			1
119#define DFLT_MSG		       10U
120#define DFLT_MSGMAX		       10
121#define HARD_MSGMAX		    65536
122#define MIN_MSGSIZEMAX		      128
123#define DFLT_MSGSIZE		     8192U
124#define DFLT_MSGSIZEMAX		     8192
125#define HARD_MSGSIZEMAX	    (16*1024*1024)
126#else
127static inline int mq_init_ns(struct ipc_namespace *ns) { return 0; }
128#endif
129
130#if defined(CONFIG_IPC_NS)
131extern struct ipc_namespace *copy_ipcs(unsigned long flags,
132	struct user_namespace *user_ns, struct ipc_namespace *ns);
133
134static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
135{
136	if (ns)
137		refcount_inc(&ns->ns.count);
138	return ns;
139}
140
141static inline struct ipc_namespace *get_ipc_ns_not_zero(struct ipc_namespace *ns)
142{
143	if (ns) {
144		if (refcount_inc_not_zero(&ns->ns.count))
145			return ns;
146	}
147
148	return NULL;
149}
150
151extern void put_ipc_ns(struct ipc_namespace *ns);
152#else
153static inline struct ipc_namespace *copy_ipcs(unsigned long flags,
154	struct user_namespace *user_ns, struct ipc_namespace *ns)
155{
156	if (flags & CLONE_NEWIPC)
157		return ERR_PTR(-EINVAL);
158
159	return ns;
160}
161
162static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
163{
164	return ns;
165}
166
167static inline struct ipc_namespace *get_ipc_ns_not_zero(struct ipc_namespace *ns)
168{
169	return ns;
170}
171
172static inline void put_ipc_ns(struct ipc_namespace *ns)
173{
174}
175#endif
176
177#ifdef CONFIG_POSIX_MQUEUE_SYSCTL
178
179void retire_mq_sysctls(struct ipc_namespace *ns);
180bool setup_mq_sysctls(struct ipc_namespace *ns);
181
182#else /* CONFIG_POSIX_MQUEUE_SYSCTL */
183
184static inline void retire_mq_sysctls(struct ipc_namespace *ns)
185{
186}
187
188static inline bool setup_mq_sysctls(struct ipc_namespace *ns)
189{
190	return true;
191}
192
193#endif /* CONFIG_POSIX_MQUEUE_SYSCTL */
194
195#ifdef CONFIG_SYSVIPC_SYSCTL
196
197bool setup_ipc_sysctls(struct ipc_namespace *ns);
198void retire_ipc_sysctls(struct ipc_namespace *ns);
199
200#else /* CONFIG_SYSVIPC_SYSCTL */
201
202static inline void retire_ipc_sysctls(struct ipc_namespace *ns)
203{
204}
205
206static inline bool setup_ipc_sysctls(struct ipc_namespace *ns)
207{
208	return true;
209}
210
211#endif /* CONFIG_SYSVIPC_SYSCTL */
212#endif
213