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 rwsem;
  26        struct idr ipcs_idr;
  27        int next_id;
  28};
  29
  30struct 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        RH_KABI_EXTEND(struct ucounts *ucounts)
  74};
  75
  76extern struct ipc_namespace init_ipc_ns;
  77extern atomic_t nr_ipc_ns;
  78
  79extern spinlock_t mq_lock;
  80
  81#ifdef CONFIG_SYSVIPC
  82extern int register_ipcns_notifier(struct ipc_namespace *);
  83extern int cond_register_ipcns_notifier(struct ipc_namespace *);
  84extern void unregister_ipcns_notifier(struct ipc_namespace *);
  85extern int ipcns_notify(unsigned long);
  86extern void shm_destroy_orphaned(struct ipc_namespace *ns);
  87#else /* CONFIG_SYSVIPC */
  88static inline int register_ipcns_notifier(struct ipc_namespace *ns)
  89{ return 0; }
  90static inline int cond_register_ipcns_notifier(struct ipc_namespace *ns)
  91{ return 0; }
  92static inline void unregister_ipcns_notifier(struct ipc_namespace *ns) { }
  93static inline int ipcns_notify(unsigned long l) { return 0; }
  94static inline void shm_destroy_orphaned(struct ipc_namespace *ns) {}
  95#endif /* CONFIG_SYSVIPC */
  96
  97#ifdef CONFIG_POSIX_MQUEUE
  98extern int mq_init_ns(struct ipc_namespace *ns);
  99/*
 100 * POSIX Message Queue default values:
 101 *
 102 * MIN_*: Lowest value an admin can set the maximum unprivileged limit to
 103 * DFLT_*MAX: Default values for the maximum unprivileged limits
 104 * DFLT_{MSG,MSGSIZE}: Default values used when the user doesn't supply
 105 *   an attribute to the open call and the queue must be created
 106 * HARD_*: Highest value the maximums can be set to.  These are enforced
 107 *   on CAP_SYS_RESOURCE apps as well making them inviolate (so make them
 108 *   suitably high)
 109 *
 110 * POSIX Requirements:
 111 *   Per app minimum openable message queues - 8.  This does not map well
 112 *     to the fact that we limit the number of queues on a per namespace
 113 *     basis instead of a per app basis.  So, make the default high enough
 114 *     that no given app should have a hard time opening 8 queues.
 115 *   Minimum maximum for HARD_MSGMAX - 32767.  I bumped this to 65536.
 116 *   Minimum maximum for HARD_MSGSIZEMAX - POSIX is silent on this.  However,
 117 *     we have run into a situation where running applications in the wild
 118 *     require this to be at least 5MB, and preferably 10MB, so I set the
 119 *     value to 16MB in hopes that this user is the worst of the bunch and
 120 *     the new maximum will handle anyone else.  I may have to revisit this
 121 *     in the future.
 122 */
 123#define DFLT_QUEUESMAX                256
 124#define MIN_MSGMAX                      1
 125#define DFLT_MSG                       10U
 126#define DFLT_MSGMAX                    10
 127#define HARD_MSGMAX                 65536
 128#define MIN_MSGSIZEMAX                128
 129#define DFLT_MSGSIZE                 8192U
 130#define DFLT_MSGSIZEMAX              8192
 131#define HARD_MSGSIZEMAX     (16*1024*1024)
 132#else
 133static inline int mq_init_ns(struct ipc_namespace *ns) { return 0; }
 134#endif
 135
 136#if defined(CONFIG_IPC_NS)
 137extern struct ipc_namespace *copy_ipcs(unsigned long flags,
 138        struct user_namespace *user_ns, struct ipc_namespace *ns);
 139
 140static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
 141{
 142        if (ns)
 143                atomic_inc(&ns->count);
 144        return ns;
 145}
 146
 147extern void put_ipc_ns(struct ipc_namespace *ns);
 148#else
 149static inline struct ipc_namespace *copy_ipcs(unsigned long flags,
 150        struct user_namespace *user_ns, struct ipc_namespace *ns)
 151{
 152        if (flags & CLONE_NEWIPC)
 153                return ERR_PTR(-EINVAL);
 154
 155        return ns;
 156}
 157
 158static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
 159{
 160        return ns;
 161}
 162
 163static inline void put_ipc_ns(struct ipc_namespace *ns)
 164{
 165}
 166#endif
 167
 168#ifdef CONFIG_POSIX_MQUEUE_SYSCTL
 169
 170struct ctl_table_header;
 171extern struct ctl_table_header *mq_register_sysctl_table(void);
 172
 173#else /* CONFIG_POSIX_MQUEUE_SYSCTL */
 174
 175static inline struct ctl_table_header *mq_register_sysctl_table(void)
 176{
 177        return NULL;
 178}
 179
 180#endif /* CONFIG_POSIX_MQUEUE_SYSCTL */
 181#endif
 182