linux/include/linux/ipc_namespace.h
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   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
  19struct user_namespace;
  20
  21struct 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
  29struct 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
  72extern struct ipc_namespace init_ipc_ns;
  73extern atomic_t nr_ipc_ns;
  74
  75extern spinlock_t mq_lock;
  76
  77#ifdef CONFIG_SYSVIPC
  78extern int register_ipcns_notifier(struct ipc_namespace *);
  79extern int cond_register_ipcns_notifier(struct ipc_namespace *);
  80extern void unregister_ipcns_notifier(struct ipc_namespace *);
  81extern int ipcns_notify(unsigned long);
  82extern void shm_destroy_orphaned(struct ipc_namespace *ns);
  83#else /* CONFIG_SYSVIPC */
  84static inline int register_ipcns_notifier(struct ipc_namespace *ns)
  85{ return 0; }
  86static inline int cond_register_ipcns_notifier(struct ipc_namespace *ns)
  87{ return 0; }
  88static inline void unregister_ipcns_notifier(struct ipc_namespace *ns) { }
  89static inline int ipcns_notify(unsigned long l) { return 0; }
  90static inline void shm_destroy_orphaned(struct ipc_namespace *ns) {}
  91#endif /* CONFIG_SYSVIPC */
  92
  93#ifdef CONFIG_POSIX_MQUEUE
  94extern 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
 131static inline int mq_init_ns(struct ipc_namespace *ns) { return 0; }
 132#endif
 133
 134#if defined(CONFIG_IPC_NS)
 135extern struct ipc_namespace *copy_ipcs(unsigned long flags,
 136                                       struct task_struct *tsk);
 137static 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
 144extern void put_ipc_ns(struct ipc_namespace *ns);
 145#else
 146static 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
 155static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
 156{
 157        return ns;
 158}
 159
 160static inline void put_ipc_ns(struct ipc_namespace *ns)
 161{
 162}
 163#endif
 164
 165#ifdef CONFIG_POSIX_MQUEUE_SYSCTL
 166
 167struct ctl_table_header;
 168extern struct ctl_table_header *mq_register_sysctl_table(void);
 169
 170#else /* CONFIG_POSIX_MQUEUE_SYSCTL */
 171
 172static inline struct ctl_table_header *mq_register_sysctl_table(void)
 173{
 174        return NULL;
 175}
 176
 177#endif /* CONFIG_POSIX_MQUEUE_SYSCTL */
 178#endif
 179
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