1 #ifndef __IPC_NAMESPACE_H__
2 #define __IPC_NAMESPACE_H__
3
4 #include <linux/err.h>
5 #include <linux/idr.h>
6 #include <linux/rwsem.h>
7 #include <linux/notifier.h>
8 #include <linux/nsproxy.h>
9 #include <linux/ns_common.h>
10
11 struct user_namespace;
12
13 struct ipc_ids {
14 int in_use;
15 unsigned short seq;
16 struct rw_semaphore rwsem;
17 struct idr ipcs_idr;
18 int next_id;
19 };
20
21 struct ipc_namespace {
22 atomic_t count;
23 struct ipc_ids ids[3];
24
25 int sem_ctls[4];
26 int used_sems;
27
28 unsigned int msg_ctlmax;
29 unsigned int msg_ctlmnb;
30 unsigned int msg_ctlmni;
31 atomic_t msg_bytes;
32 atomic_t msg_hdrs;
33
34 size_t shm_ctlmax;
35 size_t shm_ctlall;
36 unsigned long shm_tot;
37 int shm_ctlmni;
38 /*
39 * Defines whether IPC_RMID is forced for _all_ shm segments regardless
40 * of shmctl()
41 */
42 int shm_rmid_forced;
43
44 struct notifier_block ipcns_nb;
45
46 /* The kern_mount of the mqueuefs sb. We take a ref on it */
47 struct vfsmount *mq_mnt;
48
49 /* # queues in this ns, protected by mq_lock */
50 unsigned int mq_queues_count;
51
52 /* next fields are set through sysctl */
53 unsigned int mq_queues_max; /* initialized to DFLT_QUEUESMAX */
54 unsigned int mq_msg_max; /* initialized to DFLT_MSGMAX */
55 unsigned int mq_msgsize_max; /* initialized to DFLT_MSGSIZEMAX */
56 unsigned int mq_msg_default;
57 unsigned int mq_msgsize_default;
58
59 /* user_ns which owns the ipc ns */
60 struct user_namespace *user_ns;
61
62 struct ns_common ns;
63 };
64
65 extern struct ipc_namespace init_ipc_ns;
66 extern atomic_t nr_ipc_ns;
67
68 extern spinlock_t mq_lock;
69
70 #ifdef CONFIG_SYSVIPC
71 extern void shm_destroy_orphaned(struct ipc_namespace *ns);
72 #else /* CONFIG_SYSVIPC */
shm_destroy_orphaned(struct ipc_namespace * ns)73 static inline void shm_destroy_orphaned(struct ipc_namespace *ns) {}
74 #endif /* CONFIG_SYSVIPC */
75
76 #ifdef CONFIG_POSIX_MQUEUE
77 extern int mq_init_ns(struct ipc_namespace *ns);
78 /*
79 * POSIX Message Queue default values:
80 *
81 * MIN_*: Lowest value an admin can set the maximum unprivileged limit to
82 * DFLT_*MAX: Default values for the maximum unprivileged limits
83 * DFLT_{MSG,MSGSIZE}: Default values used when the user doesn't supply
84 * an attribute to the open call and the queue must be created
85 * HARD_*: Highest value the maximums can be set to. These are enforced
86 * on CAP_SYS_RESOURCE apps as well making them inviolate (so make them
87 * suitably high)
88 *
89 * POSIX Requirements:
90 * Per app minimum openable message queues - 8. This does not map well
91 * to the fact that we limit the number of queues on a per namespace
92 * basis instead of a per app basis. So, make the default high enough
93 * that no given app should have a hard time opening 8 queues.
94 * Minimum maximum for HARD_MSGMAX - 32767. I bumped this to 65536.
95 * Minimum maximum for HARD_MSGSIZEMAX - POSIX is silent on this. However,
96 * we have run into a situation where running applications in the wild
97 * require this to be at least 5MB, and preferably 10MB, so I set the
98 * value to 16MB in hopes that this user is the worst of the bunch and
99 * the new maximum will handle anyone else. I may have to revisit this
100 * in the future.
101 */
102 #define DFLT_QUEUESMAX 256
103 #define MIN_MSGMAX 1
104 #define DFLT_MSG 10U
105 #define DFLT_MSGMAX 10
106 #define HARD_MSGMAX 65536
107 #define MIN_MSGSIZEMAX 128
108 #define DFLT_MSGSIZE 8192U
109 #define DFLT_MSGSIZEMAX 8192
110 #define HARD_MSGSIZEMAX (16*1024*1024)
111 #else
mq_init_ns(struct ipc_namespace * ns)112 static inline int mq_init_ns(struct ipc_namespace *ns) { return 0; }
113 #endif
114
115 #if defined(CONFIG_IPC_NS)
116 extern struct ipc_namespace *copy_ipcs(unsigned long flags,
117 struct user_namespace *user_ns, struct ipc_namespace *ns);
118
get_ipc_ns(struct ipc_namespace * ns)119 static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
120 {
121 if (ns)
122 atomic_inc(&ns->count);
123 return ns;
124 }
125
get_ipc_ns_not_zero(struct ipc_namespace * ns)126 static inline struct ipc_namespace *get_ipc_ns_not_zero(struct ipc_namespace *ns)
127 {
128 if (ns) {
129 if (atomic_inc_not_zero(&ns->count))
130 return ns;
131 }
132
133 return NULL;
134 }
135
136 extern void put_ipc_ns(struct ipc_namespace *ns);
137 #else
copy_ipcs(unsigned long flags,struct user_namespace * user_ns,struct ipc_namespace * ns)138 static inline struct ipc_namespace *copy_ipcs(unsigned long flags,
139 struct user_namespace *user_ns, struct ipc_namespace *ns)
140 {
141 if (flags & CLONE_NEWIPC)
142 return ERR_PTR(-EINVAL);
143
144 return ns;
145 }
146
get_ipc_ns(struct ipc_namespace * ns)147 static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
148 {
149 return ns;
150 }
151
get_ipc_ns_not_zero(struct ipc_namespace * ns)152 static inline struct ipc_namespace *get_ipc_ns_not_zero(struct ipc_namespace *ns)
153 {
154 return ns;
155 }
156
put_ipc_ns(struct ipc_namespace * ns)157 static inline void put_ipc_ns(struct ipc_namespace *ns)
158 {
159 }
160 #endif
161
162 #ifdef CONFIG_POSIX_MQUEUE_SYSCTL
163
164 struct ctl_table_header;
165 extern struct ctl_table_header *mq_register_sysctl_table(void);
166
167 #else /* CONFIG_POSIX_MQUEUE_SYSCTL */
168
mq_register_sysctl_table(void)169 static inline struct ctl_table_header *mq_register_sysctl_table(void)
170 {
171 return NULL;
172 }
173
174 #endif /* CONFIG_POSIX_MQUEUE_SYSCTL */
175 #endif
176