LXR linux/include/linux/user

   1#ifndef _LINUX_USER_NAMESPACE_H
   2#define _LINUX_USER_NAMESPACE_H
   3
   4#include <linux/kref.h>
   5#include <linux/nsproxy.h>
   6#include <linux/sched.h>
   7#include <linux/err.h>
   8
   9#define UID_GID_MAP_MAX_EXTENTS 5
  10
  11struct uid_gid_map {    /* 64 bytes -- 1 cache line */
  12        u32 nr_extents;
  13        struct uid_gid_extent {
  14                u32 first;
  15                u32 lower_first;
  16                u32 count;
  17        } extent[UID_GID_MAP_MAX_EXTENTS];
  18};
  19
  20struct user_namespace {
  21        struct uid_gid_map      uid_map;
  22        struct uid_gid_map      gid_map;
  23        struct uid_gid_map      projid_map;
  24        atomic_t                count;
  25        struct user_namespace   *parent;
  26        int                     level;
  27        kuid_t                  owner;
  28        kgid_t                  group;
  29        unsigned int            proc_inum;
  30        bool                    may_mount_sysfs;
  31        bool                    may_mount_proc;
  32};
  33
  34extern struct user_namespace init_user_ns;
  35
  36#ifdef CONFIG_USER_NS
  37
  38static inline struct user_namespace *get_user_ns(struct user_namespace *ns)
  39{
  40        if (ns)
  41                atomic_inc(&ns->count);
  42        return ns;
  43}
  44
  45extern int create_user_ns(struct cred *new);
  46extern int unshare_userns(unsigned long unshare_flags, struct cred **new_cred);
  47extern void free_user_ns(struct user_namespace *ns);
  48
  49static inline void put_user_ns(struct user_namespace *ns)
  50{
  51        if (ns && atomic_dec_and_test(&ns->count))
  52                free_user_ns(ns);
  53}
  54
  55struct seq_operations;
  56extern struct seq_operations proc_uid_seq_operations;
  57extern struct seq_operations proc_gid_seq_operations;
  58extern struct seq_operations proc_projid_seq_operations;
  59extern ssize_t proc_uid_map_write(struct file *, const char __user *, size_t, loff_t *);
  60extern ssize_t proc_gid_map_write(struct file *, const char __user *, size_t, loff_t *);
  61extern ssize_t proc_projid_map_write(struct file *, const char __user *, size_t, loff_t *);
  62#else
  63
  64static inline struct user_namespace *get_user_ns(struct user_namespace *ns)
  65{
  66        return &init_user_ns;
  67}
  68
  69static inline int create_user_ns(struct cred *new)
  70{
  71        return -EINVAL;
  72}
  73
  74static inline int unshare_userns(unsigned long unshare_flags,
  75                                 struct cred **new_cred)
  76{
  77        if (unshare_flags & CLONE_NEWUSER)
  78                return -EINVAL;
  79        return 0;
  80}
  81
  82static inline void put_user_ns(struct user_namespace *ns)
  83{
  84}
  85
  86#endif
  87
  88void update_mnt_policy(struct user_namespace *userns);
  89
  90#endif /* _LINUX_USER_H */
  91