Linux kernel mirror (for testing)
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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
14struct user_namespace;
15
16struct ipc_ids {
17 int in_use;
18 unsigned short seq;
19 struct rw_semaphore rwsem;
20 struct idr ipcs_idr;
21 int max_idx;
22 int last_idx; /* For wrap around detection */
23#ifdef CONFIG_CHECKPOINT_RESTORE
24 int next_id;
25#endif
26 struct rhashtable key_ht;
27};
28
29struct ipc_namespace {
30 refcount_t count;
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 /* user_ns which owns the ipc ns */
68 struct user_namespace *user_ns;
69 struct ucounts *ucounts;
70
71 struct llist_node mnt_llist;
72
73 struct ns_common ns;
74} __randomize_layout;
75
76extern struct ipc_namespace init_ipc_ns;
77extern spinlock_t mq_lock;
78
79#ifdef CONFIG_SYSVIPC
80extern void shm_destroy_orphaned(struct ipc_namespace *ns);
81#else /* CONFIG_SYSVIPC */
82static inline void shm_destroy_orphaned(struct ipc_namespace *ns) {}
83#endif /* CONFIG_SYSVIPC */
84
85#ifdef CONFIG_POSIX_MQUEUE
86extern int mq_init_ns(struct ipc_namespace *ns);
87/*
88 * POSIX Message Queue default values:
89 *
90 * MIN_*: Lowest value an admin can set the maximum unprivileged limit to
91 * DFLT_*MAX: Default values for the maximum unprivileged limits
92 * DFLT_{MSG,MSGSIZE}: Default values used when the user doesn't supply
93 * an attribute to the open call and the queue must be created
94 * HARD_*: Highest value the maximums can be set to. These are enforced
95 * on CAP_SYS_RESOURCE apps as well making them inviolate (so make them
96 * suitably high)
97 *
98 * POSIX Requirements:
99 * Per app minimum openable message queues - 8. This does not map well
100 * to the fact that we limit the number of queues on a per namespace
101 * basis instead of a per app basis. So, make the default high enough
102 * that no given app should have a hard time opening 8 queues.
103 * Minimum maximum for HARD_MSGMAX - 32767. I bumped this to 65536.
104 * Minimum maximum for HARD_MSGSIZEMAX - POSIX is silent on this. However,
105 * we have run into a situation where running applications in the wild
106 * require this to be at least 5MB, and preferably 10MB, so I set the
107 * value to 16MB in hopes that this user is the worst of the bunch and
108 * the new maximum will handle anyone else. I may have to revisit this
109 * in the future.
110 */
111#define DFLT_QUEUESMAX 256
112#define MIN_MSGMAX 1
113#define DFLT_MSG 10U
114#define DFLT_MSGMAX 10
115#define HARD_MSGMAX 65536
116#define MIN_MSGSIZEMAX 128
117#define DFLT_MSGSIZE 8192U
118#define DFLT_MSGSIZEMAX 8192
119#define HARD_MSGSIZEMAX (16*1024*1024)
120#else
121static inline int mq_init_ns(struct ipc_namespace *ns) { return 0; }
122#endif
123
124#if defined(CONFIG_IPC_NS)
125extern struct ipc_namespace *copy_ipcs(unsigned long flags,
126 struct user_namespace *user_ns, struct ipc_namespace *ns);
127
128static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
129{
130 if (ns)
131 refcount_inc(&ns->count);
132 return ns;
133}
134
135extern void put_ipc_ns(struct ipc_namespace *ns);
136#else
137static inline struct ipc_namespace *copy_ipcs(unsigned long flags,
138 struct user_namespace *user_ns, struct ipc_namespace *ns)
139{
140 if (flags & CLONE_NEWIPC)
141 return ERR_PTR(-EINVAL);
142
143 return ns;
144}
145
146static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
147{
148 return ns;
149}
150
151static inline void put_ipc_ns(struct ipc_namespace *ns)
152{
153}
154#endif
155
156#ifdef CONFIG_POSIX_MQUEUE_SYSCTL
157
158struct ctl_table_header;
159extern struct ctl_table_header *mq_register_sysctl_table(void);
160
161#else /* CONFIG_POSIX_MQUEUE_SYSCTL */
162
163static inline struct ctl_table_header *mq_register_sysctl_table(void)
164{
165 return NULL;
166}
167
168#endif /* CONFIG_POSIX_MQUEUE_SYSCTL */
169#endif