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         struct ucounts *ucounts;
  62
  63         struct ns_common ns;
  64 };
  65
  66 extern struct ipc_namespace init_ipc_ns;
  67 extern spinlock_t mq_lock;
  68
  69 #ifdef CONFIG_SYSVIPC
  70 extern void shm_destroy_orphaned(struct ipc_namespace *ns);
  71 #else /* CONFIG_SYSVIPC */
  72 static inline void shm_destroy_orphaned(struct ipc_namespace *ns) {}
  73 #endif /* CONFIG_SYSVIPC */
  74
  75 #ifdef CONFIG_POSIX_MQUEUE
  76 extern 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
 111 static inline int mq_init_ns(struct ipc_namespace *ns) { return 0; }
 112 #endif
 113
 114 #if defined(CONFIG_IPC_NS)
 115 extern struct ipc_namespace *copy_ipcs(unsigned long flags,
 116         struct user_namespace *user_ns, struct ipc_namespace *ns);
 117
 118 static 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
 125 extern void put_ipc_ns(struct ipc_namespace *ns);
 126 #else
 127 static 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
 136 static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
 137 {
 138         return ns;
 139 }
 140
 141 static inline void put_ipc_ns(struct ipc_namespace *ns)
 142 {
 143 }
 144 #endif
 145
 146 #ifdef CONFIG_POSIX_MQUEUE_SYSCTL
 147
 148 struct ctl_table_header;
 149 extern struct ctl_table_header *mq_register_sysctl_table(void);
 150
 151 #else /* CONFIG_POSIX_MQUEUE_SYSCTL */
 152
 153 static inline struct ctl_table_header *mq_register_sysctl_table(void)
 154 {
 155         return NULL;
 156 }
 157
 158 #endif /* CONFIG_POSIX_MQUEUE_SYSCTL */
 159 #endif