1 /*
2  *  Copyright (C) 2007-2010 Lawrence Livermore National Security, LLC.
3  *  Copyright (C) 2007 The Regents of the University of California.
4  *  Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
5  *  Written by Brian Behlendorf <behlendorf1@llnl.gov>.
6  *  UCRL-CODE-235197
7  *
8  *  This file is part of the SPL, Solaris Porting Layer.
9  *
10  *  The SPL is free software; you can redistribute it and/or modify it
11  *  under the terms of the GNU General Public License as published by the
12  *  Free Software Foundation; either version 2 of the License, or (at your
13  *  option) any later version.
14  *
15  *  The SPL is distributed in the hope that it will be useful, but WITHOUT
16  *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
17  *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
18  *  for more details.
19  *
20  *  You should have received a copy of the GNU General Public License along
21  *  with the SPL.  If not, see <http://www.gnu.org/licenses/>.
22  */
23 
24 #ifndef _SPL_CRED_H
25 #define	_SPL_CRED_H
26 
27 #include <linux/module.h>
28 #include <linux/cred.h>
29 #include <linux/sched.h>
30 #include <sys/types.h>
31 #include <sys/vfs.h>
32 
33 typedef struct cred cred_t;
34 
35 extern struct task_struct init_task;
36 
37 #define	kcred		((cred_t *)(init_task.cred))
38 #define	CRED()		((cred_t *)current_cred())
39 
40 /* Linux 4.9 API change, GROUP_AT was removed */
41 #ifndef GROUP_AT
42 #define	GROUP_AT(gi, i)	((gi)->gid[i])
43 #endif
44 
45 #define	KUID_TO_SUID(x)		(__kuid_val(x))
46 #define	KGID_TO_SGID(x)		(__kgid_val(x))
47 #define	SUID_TO_KUID(x)		(KUIDT_INIT(x))
48 #define	SGID_TO_KGID(x)		(KGIDT_INIT(x))
49 #define	KGIDP_TO_SGIDP(x)	(&(x)->val)
50 
51 /* Check if the user ns is the initial one */
52 static inline boolean_t
53 zfs_is_init_userns(struct user_namespace *user_ns)
54 {
55 #if defined(CONFIG_USER_NS)
56 	return (user_ns == kcred->user_ns);
57 #else
58 	return (B_FALSE);
59 #endif
60 }
61 
62 static inline struct user_namespace *zfs_i_user_ns(struct inode *inode)
63 {
64 #ifdef HAVE_SUPER_USER_NS
65 	return (inode->i_sb->s_user_ns);
66 #else
67 	return (kcred->user_ns);
68 #endif
69 }
70 
71 static inline boolean_t zfs_no_idmapping(struct user_namespace *mnt_userns,
72     struct user_namespace *fs_userns)
73 {
74 	return (zfs_is_init_userns(mnt_userns) || mnt_userns == fs_userns);
75 }
76 
77 static inline uid_t zfs_uid_to_vfsuid(struct user_namespace *mnt_userns,
78     struct user_namespace *fs_userns, uid_t uid)
79 {
80 	if (zfs_no_idmapping(mnt_userns, fs_userns))
81 		return (uid);
82 	if (!zfs_is_init_userns(fs_userns))
83 		uid = from_kuid(fs_userns, KUIDT_INIT(uid));
84 	if (uid == (uid_t)-1)
85 		return (uid);
86 	return (__kuid_val(make_kuid(mnt_userns, uid)));
87 }
88 
89 static inline gid_t zfs_gid_to_vfsgid(struct user_namespace *mnt_userns,
90     struct user_namespace *fs_userns, gid_t gid)
91 {
92 	if (zfs_no_idmapping(mnt_userns, fs_userns))
93 		return (gid);
94 	if (!zfs_is_init_userns(fs_userns))
95 		gid = from_kgid(fs_userns, KGIDT_INIT(gid));
96 	if (gid == (gid_t)-1)
97 		return (gid);
98 	return (__kgid_val(make_kgid(mnt_userns, gid)));
99 }
100 
101 static inline uid_t zfs_vfsuid_to_uid(struct user_namespace *mnt_userns,
102     struct user_namespace *fs_userns, uid_t uid)
103 {
104 	if (zfs_no_idmapping(mnt_userns, fs_userns))
105 		return (uid);
106 	uid = from_kuid(mnt_userns, KUIDT_INIT(uid));
107 	if (uid == (uid_t)-1)
108 		return (uid);
109 	if (zfs_is_init_userns(fs_userns))
110 		return (uid);
111 	return (__kuid_val(make_kuid(fs_userns, uid)));
112 }
113 
114 static inline gid_t zfs_vfsgid_to_gid(struct user_namespace *mnt_userns,
115     struct user_namespace *fs_userns, gid_t gid)
116 {
117 	if (zfs_no_idmapping(mnt_userns, fs_userns))
118 		return (gid);
119 	gid = from_kgid(mnt_userns, KGIDT_INIT(gid));
120 	if (gid == (gid_t)-1)
121 		return (gid);
122 	if (zfs_is_init_userns(fs_userns))
123 		return (gid);
124 	return (__kgid_val(make_kgid(fs_userns, gid)));
125 }
126 
127 extern void crhold(cred_t *cr);
128 extern void crfree(cred_t *cr);
129 extern uid_t crgetuid(const cred_t *cr);
130 extern uid_t crgetruid(const cred_t *cr);
131 extern gid_t crgetgid(const cred_t *cr);
132 extern int crgetngroups(const cred_t *cr);
133 extern gid_t *crgetgroups(const cred_t *cr);
134 extern int groupmember(gid_t gid, const cred_t *cr);
135 #endif  /* _SPL_CRED_H */
136