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
14 struct user_namespace;
15
16 struct 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
29 struct 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
75 extern struct ipc_namespace init_ipc_ns;
76 extern spinlock_t mq_lock;
77
78 #ifdef CONFIG_SYSVIPC
79 extern void shm_destroy_orphaned(struct ipc_namespace *ns);
80 #else /* CONFIG_SYSVIPC */
shm_destroy_orphaned(struct ipc_namespace * ns)81 static inline void shm_destroy_orphaned(struct ipc_namespace *ns) {}
82 #endif /* CONFIG_SYSVIPC */
83
84 #ifdef CONFIG_POSIX_MQUEUE
85 extern 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
mq_init_ns(struct ipc_namespace * ns)120 static inline int mq_init_ns(struct ipc_namespace *ns) { return 0; }
121 #endif
122
123 #if defined(CONFIG_IPC_NS)
124 extern struct ipc_namespace *copy_ipcs(unsigned long flags,
125 struct user_namespace *user_ns, struct ipc_namespace *ns);
126
get_ipc_ns(struct ipc_namespace * ns)127 static 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
134 extern void put_ipc_ns(struct ipc_namespace *ns);
135 #else
copy_ipcs(unsigned long flags,struct user_namespace * user_ns,struct ipc_namespace * ns)136 static inline struct ipc_namespace *copy_ipcs(unsigned long flags,
137 struct user_namespace *user_ns, struct ipc_namespace *ns)
138 {
139 if (flags & CLONE_NEWIPC)
140 return ERR_PTR(-EINVAL);
141
142 return ns;
143 }
144
get_ipc_ns(struct ipc_namespace * ns)145 static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
146 {
147 return ns;
148 }
149
put_ipc_ns(struct ipc_namespace * ns)150 static inline void put_ipc_ns(struct ipc_namespace *ns)
151 {
152 }
153 #endif
154
155 #ifdef CONFIG_POSIX_MQUEUE_SYSCTL
156
157 struct ctl_table_header;
158 extern struct ctl_table_header *mq_register_sysctl_table(void);
159
160 #else /* CONFIG_POSIX_MQUEUE_SYSCTL */
161
mq_register_sysctl_table(void)162 static inline struct ctl_table_header *mq_register_sysctl_table(void)
163 {
164 return NULL;
165 }
166
167 #endif /* CONFIG_POSIX_MQUEUE_SYSCTL */
168 #endif
169