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#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