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 #include <linux/ns_common.h>
  10
  11 struct user_namespace;
  12
  13 struct 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
  21 struct 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
  62         struct ns_common ns;
  63 };
  64
  65 extern struct ipc_namespace init_ipc_ns;
  66 extern atomic_t nr_ipc_ns;
  67
  68 extern spinlock_t mq_lock;
  69
  70 #ifdef CONFIG_SYSVIPC
  71 extern void shm_destroy_orphaned(struct ipc_namespace *ns);
  72 #else /* CONFIG_SYSVIPC */
  73 static inline void shm_destroy_orphaned(struct ipc_namespace *ns) {}
  74 #endif /* CONFIG_SYSVIPC */
  75
  76 #ifdef CONFIG_POSIX_MQUEUE
  77 extern int mq_init_ns(struct ipc_namespace *ns);
  78 /*
  79  * POSIX Message Queue default values:
  80  *
  81  * MIN_*: Lowest value an admin can set the maximum unprivileged limit to
  82  * DFLT_*MAX: Default values for the maximum unprivileged limits
  83  * DFLT_{MSG,MSGSIZE}: Default values used when the user doesn't supply
  84  *   an attribute to the open call and the queue must be created
  85  * HARD_*: Highest value the maximums can be set to.  These are enforced
  86  *   on CAP_SYS_RESOURCE apps as well making them inviolate (so make them
  87  *   suitably high)
  88  *
  89  * POSIX Requirements:
  90  *   Per app minimum openable message queues - 8.  This does not map well
  91  *     to the fact that we limit the number of queues on a per namespace
  92  *     basis instead of a per app basis.  So, make the default high enough
  93  *     that no given app should have a hard time opening 8 queues.
  94  *   Minimum maximum for HARD_MSGMAX - 32767.  I bumped this to 65536.
  95  *   Minimum maximum for HARD_MSGSIZEMAX - POSIX is silent on this.  However,
  96  *     we have run into a situation where running applications in the wild
  97  *     require this to be at least 5MB, and preferably 10MB, so I set the
  98  *     value to 16MB in hopes that this user is the worst of the bunch and
  99  *     the new maximum will handle anyone else.  I may have to revisit this
 100  *     in the future.
 101  */
 102 #define DFLT_QUEUESMAX                256
 103 #define MIN_MSGMAX                      1
 104 #define DFLT_MSG                       10U
 105 #define DFLT_MSGMAX                    10
 106 #define HARD_MSGMAX                 65536
 107 #define MIN_MSGSIZEMAX                128
 108 #define DFLT_MSGSIZE                 8192U
 109 #define DFLT_MSGSIZEMAX              8192
 110 #define HARD_MSGSIZEMAX     (16*1024*1024)
 111 #else
 112 static inline int mq_init_ns(struct ipc_namespace *ns) { return 0; }
 113 #endif
 114
 115 #if defined(CONFIG_IPC_NS)
 116 extern struct ipc_namespace *copy_ipcs(unsigned long flags,
 117         struct user_namespace *user_ns, struct ipc_namespace *ns);
 118
 119 static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
 120 {
 121         if (ns)
 122                 atomic_inc(&ns->count);
 123         return ns;
 124 }
 125
 126 extern void put_ipc_ns(struct ipc_namespace *ns);
 127 #else
 128 static inline struct ipc_namespace *copy_ipcs(unsigned long flags,
 129         struct user_namespace *user_ns, struct ipc_namespace *ns)
 130 {
 131         if (flags & CLONE_NEWIPC)
 132                 return ERR_PTR(-EINVAL);
 133
 134         return ns;
 135 }
 136
 137 static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
 138 {
 139         return ns;
 140 }
 141
 142 static inline void put_ipc_ns(struct ipc_namespace *ns)
 143 {
 144 }
 145 #endif
 146
 147 #ifdef CONFIG_POSIX_MQUEUE_SYSCTL
 148
 149 struct ctl_table_header;
 150 extern struct ctl_table_header *mq_register_sysctl_table(void);
 151
 152 #else /* CONFIG_POSIX_MQUEUE_SYSCTL */
 153
 154 static inline struct ctl_table_header *mq_register_sysctl_table(void)
 155 {
 156         return NULL;
 157 }
 158
 159 #endif /* CONFIG_POSIX_MQUEUE_SYSCTL */
 160 #endif