include/linux/ipc_namespace.h

   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 DFLT_QUEUESMAX                256
 123 #define MIN_MSGMAX                      1
 124 #define DFLT_MSG                       10U
 125 #define DFLT_MSGMAX                    10
 126 #define HARD_MSGMAX                 65536
 127 #define MIN_MSGSIZEMAX                128
 128 #define DFLT_MSGSIZE                 8192U
 129 #define DFLT_MSGSIZEMAX              8192
 130 #define HARD_MSGSIZEMAX     (16*1024*1024)
 131 #else
 132 static inline int mq_init_ns(struct ipc_namespace *ns) { return 0; }
 133 #endif
 134
 135 #if defined(CONFIG_IPC_NS)
 136 extern struct ipc_namespace *copy_ipcs(unsigned long flags,
 137         struct user_namespace *user_ns, struct ipc_namespace *ns);
 138
 139 static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
 140 {
 141         if (ns)
 142                 atomic_inc(&ns->count);
 143         return ns;
 144 }
 145
 146 extern void put_ipc_ns(struct ipc_namespace *ns);
 147 #else
 148 static inline struct ipc_namespace *copy_ipcs(unsigned long flags,
 149         struct user_namespace *user_ns, struct ipc_namespace *ns)
 150 {
 151         if (flags & CLONE_NEWIPC)
 152                 return ERR_PTR(-EINVAL);
 153
 154         return ns;
 155 }
 156
 157 static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
 158 {
 159         return ns;
 160 }
 161
 162 static inline void put_ipc_ns(struct ipc_namespace *ns)
 163 {
 164 }
 165 #endif
 166
 167 #ifdef CONFIG_POSIX_MQUEUE_SYSCTL
 168
 169 struct ctl_table_header;
 170 extern struct ctl_table_header *mq_register_sysctl_table(void);
 171
 172 #else /* CONFIG_POSIX_MQUEUE_SYSCTL */
 173
 174 static inline struct ctl_table_header *mq_register_sysctl_table(void)
 175 {
 176         return NULL;
 177 }
 178
 179 #endif /* CONFIG_POSIX_MQUEUE_SYSCTL */
 180 #endif