wrapper/user_namespace.h

   1 /* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
   2  *
   3  * wrapper/user_namespace.h
   4  *
   5  * Copyright (C) 2019 Michael Jeanson <mjeanson@efficios.com>
   6  *
   7  */
   8
   9 #ifndef _LTTNG_WRAPPER_USER_NAMESPACE_H
  10 #define _LTTNG_WRAPPER_USER_NAMESPACE_H
  11
  12 #include <linux/version.h>
  13 #include <linux/user_namespace.h>
  14
  15
  16 #if LINUX_VERSION_CODE >= KERNEL_VERSION(3, 5, 0)
  17
  18 #define lttng_current_xxuid(xxx)                                \
  19         (from_kuid_munged(&init_user_ns, current_##xxx()))
  20
  21 #define lttng_current_vxxuid(xxx)                               \
  22         (from_kuid_munged(current_user_ns(), current_##xxx()))
  23
  24 #define lttng_current_xxgid(xxx)                                \
  25         (from_kgid_munged(&init_user_ns, current_##xxx()))
  26
  27 #define lttng_current_vxxgid(xxx)                               \
  28         (from_kgid_munged(current_user_ns(), current_##xxx()))
  29
  30 static inline
  31 uid_t lttng_task_vuid(struct task_struct *p, struct user_namespace *ns)
  32 {
  33         uid_t uid;
  34         kuid_t kuid;
  35
  36         kuid = task_cred_xxx(p, uid);
  37         uid = from_kuid_munged(ns, kuid);
  38
  39         return uid;
  40 }
  41
  42 static inline
  43 gid_t lttng_task_vgid(struct task_struct *p, struct user_namespace *ns)
  44 {
  45         gid_t gid;
  46         kgid_t kgid;
  47
  48         kgid = task_cred_xxx(p, gid);
  49         gid = from_kgid_munged(ns, kgid);
  50
  51         return gid;
  52 }
  53
  54 #else
  55
  56 #define lttng_current_xxuid(xxx)        (current_##xxx())
  57
  58 #define lttng_current_vxxuid(xxx)                                       \
  59         (user_ns_map_uid(current_user_ns(), current_cred(), current_##xxx()))
  60
  61 #define lttng_current_xxgid(xxx)        (current_##xxx())
  62
  63 #define lttng_current_vxxgid(xxx)                                       \
  64         (user_ns_map_gid(current_user_ns(), current_cred(), current_##xxx()))
  65
  66 static inline
  67 uid_t lttng_task_vuid(struct task_struct *p, struct user_namespace *ns)
  68 {
  69         uid_t uid;
  70
  71         /*
  72          * __task_cred requires the RCU readlock be held
  73          */
  74         rcu_read_lock();
  75         uid = user_ns_map_uid(ns, __task_cred(p), __task_cred(p)->uid);
  76         rcu_read_unlock();
  77
  78         return uid;
  79 }
  80
  81 static inline
  82 gid_t lttng_task_vgid(struct task_struct *p, struct user_namespace *ns)
  83 {
  84         gid_t gid;
  85
  86         /*
  87          * __task_cred requires the RCU readlock be held
  88          */
  89         rcu_read_lock();
  90         gid = user_ns_map_gid(ns, __task_cred(p), __task_cred(p)->gid);
  91         rcu_read_unlock();
  92
  93         return gid;
  94 }
  95
  96 #endif
  97
  98 #define lttng_current_uid()     (lttng_current_xxuid(uid))
  99 #define lttng_current_euid()    (lttng_current_xxuid(euid))
 100 #define lttng_current_suid()    (lttng_current_xxuid(suid))
 101 #define lttng_current_fsuid()   (lttng_current_xxuid(fsuid))
 102 #define lttng_current_gid()     (lttng_current_xxgid(gid))
 103 #define lttng_current_egid()    (lttng_current_xxgid(egid))
 104 #define lttng_current_sgid()    (lttng_current_xxgid(sgid))
 105 #define lttng_current_fsgid()   (lttng_current_xxgid(fsgid))
 106
 107 #define lttng_current_vuid()    (lttng_current_vxxuid(uid))
 108 #define lttng_current_veuid()   (lttng_current_vxxuid(euid))
 109 #define lttng_current_vsuid()   (lttng_current_vxxuid(suid))
 110 #define lttng_current_vfsuid()  (lttng_current_vxxuid(fsuid))
 111 #define lttng_current_vgid()    (lttng_current_vxxgid(gid))
 112 #define lttng_current_vegid()   (lttng_current_vxxgid(egid))
 113 #define lttng_current_vsgid()   (lttng_current_vxxgid(sgid))
 114 #define lttng_current_vfsgid()  (lttng_current_vxxgid(fsgid))
 115
 116 #endif /* _LTTNG_WRAPPER_USER_NAMESPACE_H */