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 rw_mutex;
  26         struct idr ipcs_idr;
  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         int             msg_ctlmax;
  37         int             msg_ctlmnb;
  38         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         int             shm_ctlmni;
  46         int             shm_tot;
  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
  72 extern struct ipc_namespace init_ipc_ns;
  73 extern atomic_t nr_ipc_ns;
  74
  75 extern spinlock_t mq_lock;
  76
  77 #ifdef CONFIG_SYSVIPC
  78 extern int register_ipcns_notifier(struct ipc_namespace *);
  79 extern int cond_register_ipcns_notifier(struct ipc_namespace *);
  80 extern void unregister_ipcns_notifier(struct ipc_namespace *);
  81 extern int ipcns_notify(unsigned long);
  82 extern void shm_destroy_orphaned(struct ipc_namespace *ns);
  83 #else /* CONFIG_SYSVIPC */
  84 static inline int register_ipcns_notifier(struct ipc_namespace *ns)
  85 { return 0; }
  86 static inline int cond_register_ipcns_notifier(struct ipc_namespace *ns)
  87 { return 0; }
  88 static inline void unregister_ipcns_notifier(struct ipc_namespace *ns) { }
  89 static inline int ipcns_notify(unsigned long l) { return 0; }
  90 static inline void shm_destroy_orphaned(struct ipc_namespace *ns) {}
  91 #endif /* CONFIG_SYSVIPC */
  92
  93 #ifdef CONFIG_POSIX_MQUEUE
  94 extern int mq_init_ns(struct ipc_namespace *ns);
  95 /*
  96  * POSIX Message Queue default values:
  97  *
  98  * MIN_*: Lowest value an admin can set the maximum unprivileged limit to
  99  * DFLT_*MAX: Default values for the maximum unprivileged limits
 100  * DFLT_{MSG,MSGSIZE}: Default values used when the user doesn't supply
 101  *   an attribute to the open call and the queue must be created
 102  * HARD_*: Highest value the maximums can be set to.  These are enforced
 103  *   on CAP_SYS_RESOURCE apps as well making them inviolate (so make them
 104  *   suitably high)
 105  *
 106  * POSIX Requirements:
 107  *   Per app minimum openable message queues - 8.  This does not map well
 108  *     to the fact that we limit the number of queues on a per namespace
 109  *     basis instead of a per app basis.  So, make the default high enough
 110  *     that no given app should have a hard time opening 8 queues.
 111  *   Minimum maximum for HARD_MSGMAX - 32767.  I bumped this to 65536.
 112  *   Minimum maximum for HARD_MSGSIZEMAX - POSIX is silent on this.  However,
 113  *     we have run into a situation where running applications in the wild
 114  *     require this to be at least 5MB, and preferably 10MB, so I set the
 115  *     value to 16MB in hopes that this user is the worst of the bunch and
 116  *     the new maximum will handle anyone else.  I may have to revisit this
 117  *     in the future.
 118  */
 119 #define MIN_QUEUESMAX                   1
 120 #define DFLT_QUEUESMAX                256
 121 #define HARD_QUEUESMAX               1024
 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 task_struct *tsk);
 137 static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
 138 {
 139         if (ns)
 140                 atomic_inc(&ns->count);
 141         return ns;
 142 }
 143
 144 extern void put_ipc_ns(struct ipc_namespace *ns);
 145 #else
 146 static inline struct ipc_namespace *copy_ipcs(unsigned long flags,
 147                                               struct task_struct *tsk)
 148 {
 149         if (flags & CLONE_NEWIPC)
 150                 return ERR_PTR(-EINVAL);
 151
 152         return tsk->nsproxy->ipc_ns;
 153 }
 154
 155 static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
 156 {
 157         return ns;
 158 }
 159
 160 static inline void put_ipc_ns(struct ipc_namespace *ns)
 161 {
 162 }
 163 #endif
 164
 165 #ifdef CONFIG_POSIX_MQUEUE_SYSCTL
 166
 167 struct ctl_table_header;
 168 extern struct ctl_table_header *mq_register_sysctl_table(void);
 169
 170 #else /* CONFIG_POSIX_MQUEUE_SYSCTL */
 171
 172 static inline struct ctl_table_header *mq_register_sysctl_table(void)
 173 {
 174         return NULL;
 175 }
 176
 177 #endif /* CONFIG_POSIX_MQUEUE_SYSCTL */
 178 #endif