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/ns_common.h>
   7#include <linux/sched.h>
   8#include <linux/workqueue.h>
   9#include <linux/rwsem.h>
  10#include <linux/sysctl.h>
  11#include <linux/err.h>
  12
  13#define UID_GID_MAP_MAX_EXTENTS 5
  14
  15struct uid_gid_map {    /* 64 bytes -- 1 cache line */
  16        u32 nr_extents;
  17        struct uid_gid_extent {
  18                u32 first;
  19                u32 lower_first;
  20                u32 count;
  21        } extent[UID_GID_MAP_MAX_EXTENTS];
  22};
  23
  24#define USERNS_SETGROUPS_ALLOWED 1UL
  25
  26#define USERNS_INIT_FLAGS USERNS_SETGROUPS_ALLOWED
  27
  28struct ucounts;
  29
  30enum ucount_type {
  31        UCOUNT_USER_NAMESPACES,
  32        UCOUNT_PID_NAMESPACES,
  33        UCOUNT_UTS_NAMESPACES,
  34        UCOUNT_IPC_NAMESPACES,
  35        UCOUNT_NET_NAMESPACES,
  36        UCOUNT_MNT_NAMESPACES,
  37        UCOUNT_CGROUP_NAMESPACES,
  38#ifdef CONFIG_INOTIFY_USER
  39        UCOUNT_INOTIFY_INSTANCES,
  40        UCOUNT_INOTIFY_WATCHES,
  41#endif
  42        UCOUNT_COUNTS,
  43};
  44
  45struct user_namespace {
  46        struct uid_gid_map      uid_map;
  47        struct uid_gid_map      gid_map;
  48        struct uid_gid_map      projid_map;
  49        atomic_t                count;
  50        struct user_namespace   *parent;
  51        int                     level;
  52        kuid_t                  owner;
  53        kgid_t                  group;
  54        struct ns_common        ns;
  55        unsigned long           flags;
  56
  57        /* Register of per-UID persistent keyrings for this namespace */
  58#ifdef CONFIG_PERSISTENT_KEYRINGS
  59        struct key              *persistent_keyring_register;
  60        struct rw_semaphore     persistent_keyring_register_sem;
  61#endif
  62        struct work_struct      work;
  63#ifdef CONFIG_SYSCTL
  64        struct ctl_table_set    set;
  65        struct ctl_table_header *sysctls;
  66#endif
  67        struct ucounts          *ucounts;
  68        int ucount_max[UCOUNT_COUNTS];
  69} __randomize_layout;
  70
  71struct ucounts {
  72        struct hlist_node node;
  73        struct user_namespace *ns;
  74        kuid_t uid;
  75        int count;
  76        atomic_t ucount[UCOUNT_COUNTS];
  77};
  78
  79extern struct user_namespace init_user_ns;
  80
  81bool setup_userns_sysctls(struct user_namespace *ns);
  82void retire_userns_sysctls(struct user_namespace *ns);
  83struct ucounts *inc_ucount(struct user_namespace *ns, kuid_t uid, enum ucount_type type);
  84void dec_ucount(struct ucounts *ucounts, enum ucount_type type);
  85
  86#ifdef CONFIG_USER_NS
  87
  88static inline struct user_namespace *get_user_ns(struct user_namespace *ns)
  89{
  90        if (ns)
  91                atomic_inc(&ns->count);
  92        return ns;
  93}
  94
  95extern int create_user_ns(struct cred *new);
  96extern int unshare_userns(unsigned long unshare_flags, struct cred **new_cred);
  97extern void __put_user_ns(struct user_namespace *ns);
  98
  99static inline void put_user_ns(struct user_namespace *ns)
 100{
 101        if (ns && atomic_dec_and_test(&ns->count))
 102                __put_user_ns(ns);
 103}
 104
 105struct seq_operations;
 106extern const struct seq_operations proc_uid_seq_operations;
 107extern const struct seq_operations proc_gid_seq_operations;
 108extern const struct seq_operations proc_projid_seq_operations;
 109extern ssize_t proc_uid_map_write(struct file *, const char __user *, size_t, loff_t *);
 110extern ssize_t proc_gid_map_write(struct file *, const char __user *, size_t, loff_t *);
 111extern ssize_t proc_projid_map_write(struct file *, const char __user *, size_t, loff_t *);
 112extern ssize_t proc_setgroups_write(struct file *, const char __user *, size_t, loff_t *);
 113extern int proc_setgroups_show(struct seq_file *m, void *v);
 114extern bool userns_may_setgroups(const struct user_namespace *ns);
 115extern bool current_in_userns(const struct user_namespace *target_ns);
 116
 117struct ns_common *ns_get_owner(struct ns_common *ns);
 118#else
 119
 120static inline struct user_namespace *get_user_ns(struct user_namespace *ns)
 121{
 122        return &init_user_ns;
 123}
 124
 125static inline int create_user_ns(struct cred *new)
 126{
 127        return -EINVAL;
 128}
 129
 130static inline int unshare_userns(unsigned long unshare_flags,
 131                                 struct cred **new_cred)
 132{
 133        if (unshare_flags & CLONE_NEWUSER)
 134                return -EINVAL;
 135        return 0;
 136}
 137
 138static inline void put_user_ns(struct user_namespace *ns)
 139{
 140}
 141
 142static inline bool userns_may_setgroups(const struct user_namespace *ns)
 143{
 144        return true;
 145}
 146
 147static inline bool current_in_userns(const struct user_namespace *target_ns)
 148{
 149        return true;
 150}
 151
 152static inline struct ns_common *ns_get_owner(struct ns_common *ns)
 153{
 154        return ERR_PTR(-EPERM);
 155}
 156#endif
 157
 158#endif /* _LINUX_USER_H */
 159