xref: /openbmc/linux/include/linux/ipc_namespace.h (revision afb46f79)
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 
10 /*
11  * ipc namespace events
12  */
13 #define IPCNS_MEMCHANGED   0x00000001   /* Notify lowmem size changed */
14 #define IPCNS_CREATED  0x00000002   /* Notify new ipc namespace created */
15 #define IPCNS_REMOVED  0x00000003   /* Notify ipc namespace removed */
16 
17 #define IPCNS_CALLBACK_PRI 0
18 
19 struct user_namespace;
20 
21 struct ipc_ids {
22 	int in_use;
23 	unsigned short seq;
24 	struct rw_semaphore rwsem;
25 	struct idr ipcs_idr;
26 	int next_id;
27 };
28 
29 struct ipc_namespace {
30 	atomic_t	count;
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 	int		auto_msgmni;
42 
43 	size_t		shm_ctlmax;
44 	size_t		shm_ctlall;
45 	unsigned long	shm_tot;
46 	int		shm_ctlmni;
47 	/*
48 	 * Defines whether IPC_RMID is forced for _all_ shm segments regardless
49 	 * of shmctl()
50 	 */
51 	int		shm_rmid_forced;
52 
53 	struct notifier_block ipcns_nb;
54 
55 	/* The kern_mount of the mqueuefs sb.  We take a ref on it */
56 	struct vfsmount	*mq_mnt;
57 
58 	/* # queues in this ns, protected by mq_lock */
59 	unsigned int    mq_queues_count;
60 
61 	/* next fields are set through sysctl */
62 	unsigned int    mq_queues_max;   /* initialized to DFLT_QUEUESMAX */
63 	unsigned int    mq_msg_max;      /* initialized to DFLT_MSGMAX */
64 	unsigned int    mq_msgsize_max;  /* initialized to DFLT_MSGSIZEMAX */
65 	unsigned int    mq_msg_default;
66 	unsigned int    mq_msgsize_default;
67 
68 	/* user_ns which owns the ipc ns */
69 	struct user_namespace *user_ns;
70 
71 	unsigned int	proc_inum;
72 };
73 
74 extern struct ipc_namespace init_ipc_ns;
75 extern atomic_t nr_ipc_ns;
76 
77 extern spinlock_t mq_lock;
78 
79 #ifdef CONFIG_SYSVIPC
80 extern int register_ipcns_notifier(struct ipc_namespace *);
81 extern int cond_register_ipcns_notifier(struct ipc_namespace *);
82 extern void unregister_ipcns_notifier(struct ipc_namespace *);
83 extern int ipcns_notify(unsigned long);
84 extern void shm_destroy_orphaned(struct ipc_namespace *ns);
85 #else /* CONFIG_SYSVIPC */
86 static inline int register_ipcns_notifier(struct ipc_namespace *ns)
87 { return 0; }
88 static inline int cond_register_ipcns_notifier(struct ipc_namespace *ns)
89 { return 0; }
90 static inline void unregister_ipcns_notifier(struct ipc_namespace *ns) { }
91 static inline int ipcns_notify(unsigned long l) { return 0; }
92 static inline void shm_destroy_orphaned(struct ipc_namespace *ns) {}
93 #endif /* CONFIG_SYSVIPC */
94 
95 #ifdef CONFIG_POSIX_MQUEUE
96 extern int mq_init_ns(struct ipc_namespace *ns);
97 /*
98  * POSIX Message Queue default values:
99  *
100  * MIN_*: Lowest value an admin can set the maximum unprivileged limit to
101  * DFLT_*MAX: Default values for the maximum unprivileged limits
102  * DFLT_{MSG,MSGSIZE}: Default values used when the user doesn't supply
103  *   an attribute to the open call and the queue must be created
104  * HARD_*: Highest value the maximums can be set to.  These are enforced
105  *   on CAP_SYS_RESOURCE apps as well making them inviolate (so make them
106  *   suitably high)
107  *
108  * POSIX Requirements:
109  *   Per app minimum openable message queues - 8.  This does not map well
110  *     to the fact that we limit the number of queues on a per namespace
111  *     basis instead of a per app basis.  So, make the default high enough
112  *     that no given app should have a hard time opening 8 queues.
113  *   Minimum maximum for HARD_MSGMAX - 32767.  I bumped this to 65536.
114  *   Minimum maximum for HARD_MSGSIZEMAX - POSIX is silent on this.  However,
115  *     we have run into a situation where running applications in the wild
116  *     require this to be at least 5MB, and preferably 10MB, so I set the
117  *     value to 16MB in hopes that this user is the worst of the bunch and
118  *     the new maximum will handle anyone else.  I may have to revisit this
119  *     in the future.
120  */
121 #define DFLT_QUEUESMAX		      256
122 #define MIN_MSGMAX			1
123 #define DFLT_MSG		       10U
124 #define DFLT_MSGMAX		       10
125 #define HARD_MSGMAX		    65536
126 #define MIN_MSGSIZEMAX		      128
127 #define DFLT_MSGSIZE		     8192U
128 #define DFLT_MSGSIZEMAX		     8192
129 #define HARD_MSGSIZEMAX	    (16*1024*1024)
130 #else
131 static inline int mq_init_ns(struct ipc_namespace *ns) { return 0; }
132 #endif
133 
134 #if defined(CONFIG_IPC_NS)
135 extern struct ipc_namespace *copy_ipcs(unsigned long flags,
136 	struct user_namespace *user_ns, struct ipc_namespace *ns);
137 
138 static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
139 {
140 	if (ns)
141 		atomic_inc(&ns->count);
142 	return ns;
143 }
144 
145 extern void put_ipc_ns(struct ipc_namespace *ns);
146 #else
147 static inline struct ipc_namespace *copy_ipcs(unsigned long flags,
148 	struct user_namespace *user_ns, struct ipc_namespace *ns)
149 {
150 	if (flags & CLONE_NEWIPC)
151 		return ERR_PTR(-EINVAL);
152 
153 	return ns;
154 }
155 
156 static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
157 {
158 	return ns;
159 }
160 
161 static inline void put_ipc_ns(struct ipc_namespace *ns)
162 {
163 }
164 #endif
165 
166 #ifdef CONFIG_POSIX_MQUEUE_SYSCTL
167 
168 struct ctl_table_header;
169 extern struct ctl_table_header *mq_register_sysctl_table(void);
170 
171 #else /* CONFIG_POSIX_MQUEUE_SYSCTL */
172 
173 static inline struct ctl_table_header *mq_register_sysctl_table(void)
174 {
175 	return NULL;
176 }
177 
178 #endif /* CONFIG_POSIX_MQUEUE_SYSCTL */
179 #endif
180