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12#ifndef _LINUX_CRED_H
13#define _LINUX_CRED_H
14
15#include <linux/capability.h>
16#include <linux/init.h>
17#include <linux/key.h>
18#include <linux/selinux.h>
19#include <linux/atomic.h>
20#include <linux/uidgid.h>
21
22struct user_struct;
23struct cred;
24struct inode;
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28
29#define NGROUPS_SMALL 32
30#define NGROUPS_PER_BLOCK ((unsigned int)(PAGE_SIZE / sizeof(kgid_t)))
31
32struct group_info {
33 atomic_t usage;
34 int ngroups;
35 int nblocks;
36 kgid_t small_block[NGROUPS_SMALL];
37 kgid_t *blocks[0];
38};
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49static inline struct group_info *get_group_info(struct group_info *gi)
50{
51 atomic_inc(&gi->usage);
52 return gi;
53}
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58
59#define put_group_info(group_info) \
60do { \
61 if (atomic_dec_and_test(&(group_info)->usage)) \
62 groups_free(group_info); \
63} while (0)
64
65extern struct group_info init_groups;
66#ifdef CONFIG_MULTIUSER
67extern struct group_info *groups_alloc(int);
68extern void groups_free(struct group_info *);
69
70extern int in_group_p(kgid_t);
71extern int in_egroup_p(kgid_t);
72#else
73static inline void groups_free(struct group_info *group_info)
74{
75}
76
77static inline int in_group_p(kgid_t grp)
78{
79 return 1;
80}
81static inline int in_egroup_p(kgid_t grp)
82{
83 return 1;
84}
85#endif
86extern int set_current_groups(struct group_info *);
87extern void set_groups(struct cred *, struct group_info *);
88extern int groups_search(const struct group_info *, kgid_t);
89extern bool may_setgroups(void);
90
91
92#define GROUP_AT(gi, i) \
93 ((gi)->blocks[(i) / NGROUPS_PER_BLOCK][(i) % NGROUPS_PER_BLOCK])
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118struct cred {
119 atomic_t usage;
120#ifdef CONFIG_DEBUG_CREDENTIALS
121 atomic_t subscribers;
122 void *put_addr;
123 unsigned magic;
124#define CRED_MAGIC 0x43736564
125#define CRED_MAGIC_DEAD 0x44656144
126#endif
127 kuid_t uid;
128 kgid_t gid;
129 kuid_t suid;
130 kgid_t sgid;
131 kuid_t euid;
132 kgid_t egid;
133 kuid_t fsuid;
134 kgid_t fsgid;
135 unsigned securebits;
136 kernel_cap_t cap_inheritable;
137 kernel_cap_t cap_permitted;
138 kernel_cap_t cap_effective;
139 kernel_cap_t cap_bset;
140 kernel_cap_t cap_ambient;
141#ifdef CONFIG_KEYS
142 unsigned char jit_keyring;
143
144 struct key __rcu *session_keyring;
145 struct key *process_keyring;
146 struct key *thread_keyring;
147 struct key *request_key_auth;
148#endif
149#ifdef CONFIG_SECURITY
150 void *security;
151#endif
152 struct user_struct *user;
153 struct user_namespace *user_ns;
154 struct group_info *group_info;
155 struct rcu_head rcu;
156};
157
158extern void __put_cred(struct cred *);
159extern void exit_creds(struct task_struct *);
160extern int copy_creds(struct task_struct *, unsigned long);
161extern const struct cred *get_task_cred(struct task_struct *);
162extern struct cred *cred_alloc_blank(void);
163extern struct cred *prepare_creds(void);
164extern struct cred *prepare_exec_creds(void);
165extern int commit_creds(struct cred *);
166extern void abort_creds(struct cred *);
167extern const struct cred *override_creds(const struct cred *);
168extern void revert_creds(const struct cred *);
169extern struct cred *prepare_kernel_cred(struct task_struct *);
170extern int change_create_files_as(struct cred *, struct inode *);
171extern int set_security_override(struct cred *, u32);
172extern int set_security_override_from_ctx(struct cred *, const char *);
173extern int set_create_files_as(struct cred *, struct inode *);
174extern void __init cred_init(void);
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178
179#ifdef CONFIG_DEBUG_CREDENTIALS
180extern void __invalid_creds(const struct cred *, const char *, unsigned);
181extern void __validate_process_creds(struct task_struct *,
182 const char *, unsigned);
183
184extern bool creds_are_invalid(const struct cred *cred);
185
186static inline void __validate_creds(const struct cred *cred,
187 const char *file, unsigned line)
188{
189 if (unlikely(creds_are_invalid(cred)))
190 __invalid_creds(cred, file, line);
191}
192
193#define validate_creds(cred) \
194do { \
195 __validate_creds((cred), __FILE__, __LINE__); \
196} while(0)
197
198#define validate_process_creds() \
199do { \
200 __validate_process_creds(current, __FILE__, __LINE__); \
201} while(0)
202
203extern void validate_creds_for_do_exit(struct task_struct *);
204#else
205static inline void validate_creds(const struct cred *cred)
206{
207}
208static inline void validate_creds_for_do_exit(struct task_struct *tsk)
209{
210}
211static inline void validate_process_creds(void)
212{
213}
214#endif
215
216static inline bool cap_ambient_invariant_ok(const struct cred *cred)
217{
218 return cap_issubset(cred->cap_ambient,
219 cap_intersect(cred->cap_permitted,
220 cred->cap_inheritable));
221}
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230static inline struct cred *get_new_cred(struct cred *cred)
231{
232 atomic_inc(&cred->usage);
233 return cred;
234}
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249static inline const struct cred *get_cred(const struct cred *cred)
250{
251 struct cred *nonconst_cred = (struct cred *) cred;
252 validate_creds(cred);
253 return get_new_cred(nonconst_cred);
254}
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267static inline void put_cred(const struct cred *_cred)
268{
269 struct cred *cred = (struct cred *) _cred;
270
271 validate_creds(cred);
272 if (atomic_dec_and_test(&(cred)->usage))
273 __put_cred(cred);
274}
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282#define current_cred() \
283 rcu_dereference_protected(current->cred, 1)
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291#define current_real_cred() \
292 rcu_dereference_protected(current->real_cred, 1)
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304#define __task_cred(task) \
305 rcu_dereference((task)->real_cred)
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314#define get_current_cred() \
315 (get_cred(current_cred()))
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323#define get_current_user() \
324({ \
325 struct user_struct *__u; \
326 const struct cred *__cred; \
327 __cred = current_cred(); \
328 __u = get_uid(__cred->user); \
329 __u; \
330})
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337
338#define get_current_groups() \
339({ \
340 struct group_info *__groups; \
341 const struct cred *__cred; \
342 __cred = current_cred(); \
343 __groups = get_group_info(__cred->group_info); \
344 __groups; \
345})
346
347#define task_cred_xxx(task, xxx) \
348({ \
349 __typeof__(((struct cred *)NULL)->xxx) ___val; \
350 rcu_read_lock(); \
351 ___val = __task_cred((task))->xxx; \
352 rcu_read_unlock(); \
353 ___val; \
354})
355
356#define task_uid(task) (task_cred_xxx((task), uid))
357#define task_euid(task) (task_cred_xxx((task), euid))
358
359#define current_cred_xxx(xxx) \
360({ \
361 current_cred()->xxx; \
362})
363
364#define current_uid() (current_cred_xxx(uid))
365#define current_gid() (current_cred_xxx(gid))
366#define current_euid() (current_cred_xxx(euid))
367#define current_egid() (current_cred_xxx(egid))
368#define current_suid() (current_cred_xxx(suid))
369#define current_sgid() (current_cred_xxx(sgid))
370#define current_fsuid() (current_cred_xxx(fsuid))
371#define current_fsgid() (current_cred_xxx(fsgid))
372#define current_cap() (current_cred_xxx(cap_effective))
373#define current_user() (current_cred_xxx(user))
374#define current_security() (current_cred_xxx(security))
375
376extern struct user_namespace init_user_ns;
377#ifdef CONFIG_USER_NS
378#define current_user_ns() (current_cred_xxx(user_ns))
379#else
380static inline struct user_namespace *current_user_ns(void)
381{
382 return &init_user_ns;
383}
384#endif
385
386
387#define current_uid_gid(_uid, _gid) \
388do { \
389 const struct cred *__cred; \
390 __cred = current_cred(); \
391 *(_uid) = __cred->uid; \
392 *(_gid) = __cred->gid; \
393} while(0)
394
395#define current_euid_egid(_euid, _egid) \
396do { \
397 const struct cred *__cred; \
398 __cred = current_cred(); \
399 *(_euid) = __cred->euid; \
400 *(_egid) = __cred->egid; \
401} while(0)
402
403#define current_fsuid_fsgid(_fsuid, _fsgid) \
404do { \
405 const struct cred *__cred; \
406 __cred = current_cred(); \
407 *(_fsuid) = __cred->fsuid; \
408 *(_fsgid) = __cred->fsgid; \
409} while(0)
410
411#endif
412