1 /* internal.h: authentication token and access key management internal defs 2 * 3 * Copyright (C) 2003-5, 2007 Red Hat, Inc. All Rights Reserved. 4 * Written by David Howells (dhowells@redhat.com) 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License 8 * as published by the Free Software Foundation; either version 9 * 2 of the License, or (at your option) any later version. 10 */ 11 12 #ifndef _INTERNAL_H 13 #define _INTERNAL_H 14 15 #include <linux/sched.h> 16 #include <linux/key-type.h> 17 18 static inline __attribute__((format(printf, 1, 2))) 19 void no_printk(const char *fmt, ...) 20 { 21 } 22 23 #ifdef __KDEBUG 24 #define kenter(FMT, ...) \ 25 printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__) 26 #define kleave(FMT, ...) \ 27 printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__) 28 #define kdebug(FMT, ...) \ 29 printk(KERN_DEBUG " "FMT"\n", ##__VA_ARGS__) 30 #else 31 #define kenter(FMT, ...) \ 32 no_printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__) 33 #define kleave(FMT, ...) \ 34 no_printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__) 35 #define kdebug(FMT, ...) \ 36 no_printk(KERN_DEBUG FMT"\n", ##__VA_ARGS__) 37 #endif 38 39 extern struct key_type key_type_user; 40 41 /*****************************************************************************/ 42 /* 43 * keep track of keys for a user 44 * - this needs to be separate to user_struct to avoid a refcount-loop 45 * (user_struct pins some keyrings which pin this struct) 46 * - this also keeps track of keys under request from userspace for this UID 47 */ 48 struct key_user { 49 struct rb_node node; 50 struct mutex cons_lock; /* construction initiation lock */ 51 spinlock_t lock; 52 atomic_t usage; /* for accessing qnkeys & qnbytes */ 53 atomic_t nkeys; /* number of keys */ 54 atomic_t nikeys; /* number of instantiated keys */ 55 uid_t uid; 56 struct user_namespace *user_ns; 57 int qnkeys; /* number of keys allocated to this user */ 58 int qnbytes; /* number of bytes allocated to this user */ 59 }; 60 61 extern struct rb_root key_user_tree; 62 extern spinlock_t key_user_lock; 63 extern struct key_user root_key_user; 64 65 extern struct key_user *key_user_lookup(uid_t uid, 66 struct user_namespace *user_ns); 67 extern void key_user_put(struct key_user *user); 68 69 /* 70 * key quota limits 71 * - root has its own separate limits to everyone else 72 */ 73 extern unsigned key_quota_root_maxkeys; 74 extern unsigned key_quota_root_maxbytes; 75 extern unsigned key_quota_maxkeys; 76 extern unsigned key_quota_maxbytes; 77 78 #define KEYQUOTA_LINK_BYTES 4 /* a link in a keyring is worth 4 bytes */ 79 80 81 extern struct rb_root key_serial_tree; 82 extern spinlock_t key_serial_lock; 83 extern struct mutex key_construction_mutex; 84 extern wait_queue_head_t request_key_conswq; 85 86 87 extern struct key_type *key_type_lookup(const char *type); 88 extern void key_type_put(struct key_type *ktype); 89 90 extern int __key_link_begin(struct key *keyring, 91 const struct key_type *type, 92 const char *description, 93 struct keyring_list **_prealloc); 94 extern int __key_link_check_live_key(struct key *keyring, struct key *key); 95 extern void __key_link(struct key *keyring, struct key *key, 96 struct keyring_list **_prealloc); 97 extern void __key_link_end(struct key *keyring, 98 struct key_type *type, 99 struct keyring_list *prealloc); 100 101 extern key_ref_t __keyring_search_one(key_ref_t keyring_ref, 102 const struct key_type *type, 103 const char *description, 104 key_perm_t perm); 105 106 extern struct key *keyring_search_instkey(struct key *keyring, 107 key_serial_t target_id); 108 109 typedef int (*key_match_func_t)(const struct key *, const void *); 110 111 extern key_ref_t keyring_search_aux(key_ref_t keyring_ref, 112 const struct cred *cred, 113 struct key_type *type, 114 const void *description, 115 key_match_func_t match); 116 117 extern key_ref_t search_process_keyrings(struct key_type *type, 118 const void *description, 119 key_match_func_t match, 120 const struct cred *cred); 121 122 extern struct key *find_keyring_by_name(const char *name, bool skip_perm_check); 123 124 extern int install_user_keyrings(void); 125 extern int install_thread_keyring_to_cred(struct cred *); 126 extern int install_process_keyring_to_cred(struct cred *); 127 extern int install_session_keyring_to_cred(struct cred *, struct key *); 128 129 extern struct key *request_key_and_link(struct key_type *type, 130 const char *description, 131 const void *callout_info, 132 size_t callout_len, 133 void *aux, 134 struct key *dest_keyring, 135 unsigned long flags); 136 137 extern key_ref_t lookup_user_key(key_serial_t id, unsigned long flags, 138 key_perm_t perm); 139 #define KEY_LOOKUP_CREATE 0x01 140 #define KEY_LOOKUP_PARTIAL 0x02 141 #define KEY_LOOKUP_FOR_UNLINK 0x04 142 143 extern long join_session_keyring(const char *name); 144 145 extern unsigned key_gc_delay; 146 extern void keyring_gc(struct key *keyring, time_t limit); 147 extern void key_schedule_gc(time_t expiry_at); 148 149 /* 150 * check to see whether permission is granted to use a key in the desired way 151 */ 152 extern int key_task_permission(const key_ref_t key_ref, 153 const struct cred *cred, 154 key_perm_t perm); 155 156 static inline int key_permission(const key_ref_t key_ref, key_perm_t perm) 157 { 158 return key_task_permission(key_ref, current_cred(), perm); 159 } 160 161 /* required permissions */ 162 #define KEY_VIEW 0x01 /* require permission to view attributes */ 163 #define KEY_READ 0x02 /* require permission to read content */ 164 #define KEY_WRITE 0x04 /* require permission to update / modify */ 165 #define KEY_SEARCH 0x08 /* require permission to search (keyring) or find (key) */ 166 #define KEY_LINK 0x10 /* require permission to link */ 167 #define KEY_SETATTR 0x20 /* require permission to change attributes */ 168 #define KEY_ALL 0x3f /* all the above permissions */ 169 170 /* 171 * request_key authorisation 172 */ 173 struct request_key_auth { 174 struct key *target_key; 175 struct key *dest_keyring; 176 const struct cred *cred; 177 void *callout_info; 178 size_t callout_len; 179 pid_t pid; 180 }; 181 182 extern struct key_type key_type_request_key_auth; 183 extern struct key *request_key_auth_new(struct key *target, 184 const void *callout_info, 185 size_t callout_len, 186 struct key *dest_keyring); 187 188 extern struct key *key_get_instantiation_authkey(key_serial_t target_id); 189 190 /* 191 * keyctl functions 192 */ 193 extern long keyctl_get_keyring_ID(key_serial_t, int); 194 extern long keyctl_join_session_keyring(const char __user *); 195 extern long keyctl_update_key(key_serial_t, const void __user *, size_t); 196 extern long keyctl_revoke_key(key_serial_t); 197 extern long keyctl_keyring_clear(key_serial_t); 198 extern long keyctl_keyring_link(key_serial_t, key_serial_t); 199 extern long keyctl_keyring_unlink(key_serial_t, key_serial_t); 200 extern long keyctl_describe_key(key_serial_t, char __user *, size_t); 201 extern long keyctl_keyring_search(key_serial_t, const char __user *, 202 const char __user *, key_serial_t); 203 extern long keyctl_read_key(key_serial_t, char __user *, size_t); 204 extern long keyctl_chown_key(key_serial_t, uid_t, gid_t); 205 extern long keyctl_setperm_key(key_serial_t, key_perm_t); 206 extern long keyctl_instantiate_key(key_serial_t, const void __user *, 207 size_t, key_serial_t); 208 extern long keyctl_negate_key(key_serial_t, unsigned, key_serial_t); 209 extern long keyctl_set_reqkey_keyring(int); 210 extern long keyctl_set_timeout(key_serial_t, unsigned); 211 extern long keyctl_assume_authority(key_serial_t); 212 extern long keyctl_get_security(key_serial_t keyid, char __user *buffer, 213 size_t buflen); 214 extern long keyctl_session_to_parent(void); 215 216 /* 217 * debugging key validation 218 */ 219 #ifdef KEY_DEBUGGING 220 extern void __key_check(const struct key *); 221 222 static inline void key_check(const struct key *key) 223 { 224 if (key && (IS_ERR(key) || key->magic != KEY_DEBUG_MAGIC)) 225 __key_check(key); 226 } 227 228 #else 229 230 #define key_check(key) do {} while(0) 231 232 #endif 233 234 #endif /* _INTERNAL_H */ 235