xref: /openbmc/linux/include/linux/ipc_namespace.h (revision 12eb4683)
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 	unsigned short seq_max;
25 	struct rw_semaphore rwsem;
26 	struct idr ipcs_idr;
27 	int next_id;
28 };
29 
30 struct ipc_namespace {
31 	atomic_t	count;
32 	struct ipc_ids	ids[3];
33 
34 	int		sem_ctls[4];
35 	int		used_sems;
36 
37 	unsigned int	msg_ctlmax;
38 	unsigned int	msg_ctlmnb;
39 	unsigned int	msg_ctlmni;
40 	atomic_t	msg_bytes;
41 	atomic_t	msg_hdrs;
42 	int		auto_msgmni;
43 
44 	size_t		shm_ctlmax;
45 	size_t		shm_ctlall;
46 	unsigned long	shm_tot;
47 	int		shm_ctlmni;
48 	/*
49 	 * Defines whether IPC_RMID is forced for _all_ shm segments regardless
50 	 * of shmctl()
51 	 */
52 	int		shm_rmid_forced;
53 
54 	struct notifier_block ipcns_nb;
55 
56 	/* The kern_mount of the mqueuefs sb.  We take a ref on it */
57 	struct vfsmount	*mq_mnt;
58 
59 	/* # queues in this ns, protected by mq_lock */
60 	unsigned int    mq_queues_count;
61 
62 	/* next fields are set through sysctl */
63 	unsigned int    mq_queues_max;   /* initialized to DFLT_QUEUESMAX */
64 	unsigned int    mq_msg_max;      /* initialized to DFLT_MSGMAX */
65 	unsigned int    mq_msgsize_max;  /* initialized to DFLT_MSGSIZEMAX */
66 	unsigned int    mq_msg_default;
67 	unsigned int    mq_msgsize_default;
68 
69 	/* user_ns which owns the ipc ns */
70 	struct user_namespace *user_ns;
71 
72 	unsigned int	proc_inum;
73 };
74 
75 extern struct ipc_namespace init_ipc_ns;
76 extern atomic_t nr_ipc_ns;
77 
78 extern spinlock_t mq_lock;
79 
80 #ifdef CONFIG_SYSVIPC
81 extern int register_ipcns_notifier(struct ipc_namespace *);
82 extern int cond_register_ipcns_notifier(struct ipc_namespace *);
83 extern void unregister_ipcns_notifier(struct ipc_namespace *);
84 extern int ipcns_notify(unsigned long);
85 extern void shm_destroy_orphaned(struct ipc_namespace *ns);
86 #else /* CONFIG_SYSVIPC */
87 static inline int register_ipcns_notifier(struct ipc_namespace *ns)
88 { return 0; }
89 static inline int cond_register_ipcns_notifier(struct ipc_namespace *ns)
90 { return 0; }
91 static inline void unregister_ipcns_notifier(struct ipc_namespace *ns) { }
92 static inline int ipcns_notify(unsigned long l) { return 0; }
93 static inline void shm_destroy_orphaned(struct ipc_namespace *ns) {}
94 #endif /* CONFIG_SYSVIPC */
95 
96 #ifdef CONFIG_POSIX_MQUEUE
97 extern int mq_init_ns(struct ipc_namespace *ns);
98 /*
99  * POSIX Message Queue default values:
100  *
101  * MIN_*: Lowest value an admin can set the maximum unprivileged limit to
102  * DFLT_*MAX: Default values for the maximum unprivileged limits
103  * DFLT_{MSG,MSGSIZE}: Default values used when the user doesn't supply
104  *   an attribute to the open call and the queue must be created
105  * HARD_*: Highest value the maximums can be set to.  These are enforced
106  *   on CAP_SYS_RESOURCE apps as well making them inviolate (so make them
107  *   suitably high)
108  *
109  * POSIX Requirements:
110  *   Per app minimum openable message queues - 8.  This does not map well
111  *     to the fact that we limit the number of queues on a per namespace
112  *     basis instead of a per app basis.  So, make the default high enough
113  *     that no given app should have a hard time opening 8 queues.
114  *   Minimum maximum for HARD_MSGMAX - 32767.  I bumped this to 65536.
115  *   Minimum maximum for HARD_MSGSIZEMAX - POSIX is silent on this.  However,
116  *     we have run into a situation where running applications in the wild
117  *     require this to be at least 5MB, and preferably 10MB, so I set the
118  *     value to 16MB in hopes that this user is the worst of the bunch and
119  *     the new maximum will handle anyone else.  I may have to revisit this
120  *     in the future.
121  */
122 #define MIN_QUEUESMAX			1
123 #define DFLT_QUEUESMAX		      256
124 #define HARD_QUEUESMAX		     1024
125 #define MIN_MSGMAX			1
126 #define DFLT_MSG		       10U
127 #define DFLT_MSGMAX		       10
128 #define HARD_MSGMAX		    65536
129 #define MIN_MSGSIZEMAX		      128
130 #define DFLT_MSGSIZE		     8192U
131 #define DFLT_MSGSIZEMAX		     8192
132 #define HARD_MSGSIZEMAX	    (16*1024*1024)
133 #else
134 static inline int mq_init_ns(struct ipc_namespace *ns) { return 0; }
135 #endif
136 
137 #if defined(CONFIG_IPC_NS)
138 extern struct ipc_namespace *copy_ipcs(unsigned long flags,
139 	struct user_namespace *user_ns, struct ipc_namespace *ns);
140 
141 static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
142 {
143 	if (ns)
144 		atomic_inc(&ns->count);
145 	return ns;
146 }
147 
148 extern void put_ipc_ns(struct ipc_namespace *ns);
149 #else
150 static inline struct ipc_namespace *copy_ipcs(unsigned long flags,
151 	struct user_namespace *user_ns, struct ipc_namespace *ns)
152 {
153 	if (flags & CLONE_NEWIPC)
154 		return ERR_PTR(-EINVAL);
155 
156 	return ns;
157 }
158 
159 static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
160 {
161 	return ns;
162 }
163 
164 static inline void put_ipc_ns(struct ipc_namespace *ns)
165 {
166 }
167 #endif
168 
169 #ifdef CONFIG_POSIX_MQUEUE_SYSCTL
170 
171 struct ctl_table_header;
172 extern struct ctl_table_header *mq_register_sysctl_table(void);
173 
174 #else /* CONFIG_POSIX_MQUEUE_SYSCTL */
175 
176 static inline struct ctl_table_header *mq_register_sysctl_table(void)
177 {
178 	return NULL;
179 }
180 
181 #endif /* CONFIG_POSIX_MQUEUE_SYSCTL */
182 #endif
183