LXR linux/include/linux/ipc

   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#include <linux/ns_common.h>
  10
  11struct user_namespace;
  12
  13struct ipc_ids {
  14        int in_use;
  15        unsigned short seq;
  16        struct rw_semaphore rwsem;
  17        struct idr ipcs_idr;
  18        int next_id;
  19};
  20
  21struct ipc_namespace {
  22        atomic_t        count;
  23        struct ipc_ids  ids[3];
  24
  25        int             sem_ctls[4];
  26        int             used_sems;
  27
  28        unsigned int    msg_ctlmax;
  29        unsigned int    msg_ctlmnb;
  30        unsigned int    msg_ctlmni;
  31        atomic_t        msg_bytes;
  32        atomic_t        msg_hdrs;
  33
  34        size_t          shm_ctlmax;
  35        size_t          shm_ctlall;
  36        unsigned long   shm_tot;
  37        int             shm_ctlmni;
  38        /*
  39         * Defines whether IPC_RMID is forced for _all_ shm segments regardless
  40         * of shmctl()
  41         */
  42        int             shm_rmid_forced;
  43
  44        struct notifier_block ipcns_nb;
  45
  46        /* The kern_mount of the mqueuefs sb.  We take a ref on it */
  47        struct vfsmount *mq_mnt;
  48
  49        /* # queues in this ns, protected by mq_lock */
  50        unsigned int    mq_queues_count;
  51
  52        /* next fields are set through sysctl */
  53        unsigned int    mq_queues_max;   /* initialized to DFLT_QUEUESMAX */
  54        unsigned int    mq_msg_max;      /* initialized to DFLT_MSGMAX */
  55        unsigned int    mq_msgsize_max;  /* initialized to DFLT_MSGSIZEMAX */
  56        unsigned int    mq_msg_default;
  57        unsigned int    mq_msgsize_default;
  58
  59        /* user_ns which owns the ipc ns */
  60        struct user_namespace *user_ns;
  61        struct ucounts *ucounts;
  62
  63        struct ns_common ns;
  64};
  65
  66extern struct ipc_namespace init_ipc_ns;
  67extern spinlock_t mq_lock;
  68
  69#ifdef CONFIG_SYSVIPC
  70extern void shm_destroy_orphaned(struct ipc_namespace *ns);
  71#else /* CONFIG_SYSVIPC */
  72static inline void shm_destroy_orphaned(struct ipc_namespace *ns) {}
  73#endif /* CONFIG_SYSVIPC */
  74
  75#ifdef CONFIG_POSIX_MQUEUE
  76extern int mq_init_ns(struct ipc_namespace *ns);
  77/*
  78 * POSIX Message Queue default values:
  79 *
  80 * MIN_*: Lowest value an admin can set the maximum unprivileged limit to
  81 * DFLT_*MAX: Default values for the maximum unprivileged limits
  82 * DFLT_{MSG,MSGSIZE}: Default values used when the user doesn't supply
  83 *   an attribute to the open call and the queue must be created
  84 * HARD_*: Highest value the maximums can be set to.  These are enforced
  85 *   on CAP_SYS_RESOURCE apps as well making them inviolate (so make them
  86 *   suitably high)
  87 *
  88 * POSIX Requirements:
  89 *   Per app minimum openable message queues - 8.  This does not map well
  90 *     to the fact that we limit the number of queues on a per namespace
  91 *     basis instead of a per app basis.  So, make the default high enough
  92 *     that no given app should have a hard time opening 8 queues.
  93 *   Minimum maximum for HARD_MSGMAX - 32767.  I bumped this to 65536.
  94 *   Minimum maximum for HARD_MSGSIZEMAX - POSIX is silent on this.  However,
  95 *     we have run into a situation where running applications in the wild
  96 *     require this to be at least 5MB, and preferably 10MB, so I set the
  97 *     value to 16MB in hopes that this user is the worst of the bunch and
  98 *     the new maximum will handle anyone else.  I may have to revisit this
  99 *     in the future.
 100 */
 101#define DFLT_QUEUESMAX                256
 102#define MIN_MSGMAX                      1
 103#define DFLT_MSG                       10U
 104#define DFLT_MSGMAX                    10
 105#define HARD_MSGMAX                 65536
 106#define MIN_MSGSIZEMAX                128
 107#define DFLT_MSGSIZE                 8192U
 108#define DFLT_MSGSIZEMAX              8192
 109#define HARD_MSGSIZEMAX     (16*1024*1024)
 110#else
 111static inline int mq_init_ns(struct ipc_namespace *ns) { return 0; }
 112#endif
 113
 114#if defined(CONFIG_IPC_NS)
 115extern struct ipc_namespace *copy_ipcs(unsigned long flags,
 116        struct user_namespace *user_ns, struct ipc_namespace *ns);
 117
 118static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
 119{
 120        if (ns)
 121                atomic_inc(&ns->count);
 122        return ns;
 123}
 124
 125extern void put_ipc_ns(struct ipc_namespace *ns);
 126#else
 127static inline struct ipc_namespace *copy_ipcs(unsigned long flags,
 128        struct user_namespace *user_ns, struct ipc_namespace *ns)
 129{
 130        if (flags & CLONE_NEWIPC)
 131                return ERR_PTR(-EINVAL);
 132
 133        return ns;
 134}
 135
 136static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
 137{
 138        return ns;
 139}
 140
 141static inline void put_ipc_ns(struct ipc_namespace *ns)
 142{
 143}
 144#endif
 145
 146#ifdef CONFIG_POSIX_MQUEUE_SYSCTL
 147
 148struct ctl_table_header;
 149extern struct ctl_table_header *mq_register_sysctl_table(void);
 150
 151#else /* CONFIG_POSIX_MQUEUE_SYSCTL */
 152
 153static inline struct ctl_table_header *mq_register_sysctl_table(void)
 154{
 155        return NULL;
 156}
 157
 158#endif /* CONFIG_POSIX_MQUEUE_SYSCTL */
 159#endif
 160