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 #ifdef CONFIG_CHECKPOINT_RESTORE
23 int next_id;
24 #endif
25 struct rhashtable key_ht;
26 };
27
28 struct ipc_namespace {
29 refcount_t count;
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 ns_common ns;
71 } __randomize_layout;
72
73 extern struct ipc_namespace init_ipc_ns;
74 extern spinlock_t mq_lock;
75
76 #ifdef CONFIG_SYSVIPC
77 extern void shm_destroy_orphaned(struct ipc_namespace *ns);
78 #else /* CONFIG_SYSVIPC */
shm_destroy_orphaned(struct ipc_namespace * ns)79 static inline void shm_destroy_orphaned(struct ipc_namespace *ns) {}
80 #endif /* CONFIG_SYSVIPC */
81
82 #ifdef CONFIG_POSIX_MQUEUE
83 extern int mq_init_ns(struct ipc_namespace *ns);
84 /*
85 * POSIX Message Queue default values:
86 *
87 * MIN_*: Lowest value an admin can set the maximum unprivileged limit to
88 * DFLT_*MAX: Default values for the maximum unprivileged limits
89 * DFLT_{MSG,MSGSIZE}: Default values used when the user doesn't supply
90 * an attribute to the open call and the queue must be created
91 * HARD_*: Highest value the maximums can be set to. These are enforced
92 * on CAP_SYS_RESOURCE apps as well making them inviolate (so make them
93 * suitably high)
94 *
95 * POSIX Requirements:
96 * Per app minimum openable message queues - 8. This does not map well
97 * to the fact that we limit the number of queues on a per namespace
98 * basis instead of a per app basis. So, make the default high enough
99 * that no given app should have a hard time opening 8 queues.
100 * Minimum maximum for HARD_MSGMAX - 32767. I bumped this to 65536.
101 * Minimum maximum for HARD_MSGSIZEMAX - POSIX is silent on this. However,
102 * we have run into a situation where running applications in the wild
103 * require this to be at least 5MB, and preferably 10MB, so I set the
104 * value to 16MB in hopes that this user is the worst of the bunch and
105 * the new maximum will handle anyone else. I may have to revisit this
106 * in the future.
107 */
108 #define DFLT_QUEUESMAX 256
109 #define MIN_MSGMAX 1
110 #define DFLT_MSG 10U
111 #define DFLT_MSGMAX 10
112 #define HARD_MSGMAX 65536
113 #define MIN_MSGSIZEMAX 128
114 #define DFLT_MSGSIZE 8192U
115 #define DFLT_MSGSIZEMAX 8192
116 #define HARD_MSGSIZEMAX (16*1024*1024)
117 #else
mq_init_ns(struct ipc_namespace * ns)118 static inline int mq_init_ns(struct ipc_namespace *ns) { return 0; }
119 #endif
120
121 #if defined(CONFIG_IPC_NS)
122 extern struct ipc_namespace *copy_ipcs(unsigned long flags,
123 struct user_namespace *user_ns, struct ipc_namespace *ns);
124
get_ipc_ns(struct ipc_namespace * ns)125 static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
126 {
127 if (ns)
128 refcount_inc(&ns->count);
129 return ns;
130 }
131
get_ipc_ns_not_zero(struct ipc_namespace * ns)132 static inline struct ipc_namespace *get_ipc_ns_not_zero(struct ipc_namespace *ns)
133 {
134 if (ns) {
135 if (refcount_inc_not_zero(&ns->count))
136 return ns;
137 }
138
139 return NULL;
140 }
141
142 extern void put_ipc_ns(struct ipc_namespace *ns);
143 #else
copy_ipcs(unsigned long flags,struct user_namespace * user_ns,struct ipc_namespace * ns)144 static inline struct ipc_namespace *copy_ipcs(unsigned long flags,
145 struct user_namespace *user_ns, struct ipc_namespace *ns)
146 {
147 if (flags & CLONE_NEWIPC)
148 return ERR_PTR(-EINVAL);
149
150 return ns;
151 }
152
get_ipc_ns(struct ipc_namespace * ns)153 static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
154 {
155 return ns;
156 }
157
get_ipc_ns_not_zero(struct ipc_namespace * ns)158 static inline struct ipc_namespace *get_ipc_ns_not_zero(struct ipc_namespace *ns)
159 {
160 return ns;
161 }
162
put_ipc_ns(struct ipc_namespace * ns)163 static inline void put_ipc_ns(struct ipc_namespace *ns)
164 {
165 }
166 #endif
167
168 #ifdef CONFIG_POSIX_MQUEUE_SYSCTL
169
170 struct ctl_table_header;
171 extern struct ctl_table_header *mq_register_sysctl_table(void);
172
173 #else /* CONFIG_POSIX_MQUEUE_SYSCTL */
174
mq_register_sysctl_table(void)175 static inline struct ctl_table_header *mq_register_sysctl_table(void)
176 {
177 return NULL;
178 }
179
180 #endif /* CONFIG_POSIX_MQUEUE_SYSCTL */
181 #endif
182