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