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 int qnkeys; /* number of keys allocated to this user */ 57 int qnbytes; /* number of bytes allocated to this user */ 58 }; 59 60 extern struct rb_root key_user_tree; 61 extern spinlock_t key_user_lock; 62 extern struct key_user root_key_user; 63 64 extern struct key_user *key_user_lookup(uid_t uid); 65 extern void key_user_put(struct key_user *user); 66 67 /* 68 * key quota limits 69 * - root has its own separate limits to everyone else 70 */ 71 extern unsigned key_quota_root_maxkeys; 72 extern unsigned key_quota_root_maxbytes; 73 extern unsigned key_quota_maxkeys; 74 extern unsigned key_quota_maxbytes; 75 76 #define KEYQUOTA_LINK_BYTES 4 /* a link in a keyring is worth 4 bytes */ 77 78 79 extern struct rb_root key_serial_tree; 80 extern spinlock_t key_serial_lock; 81 extern struct mutex key_construction_mutex; 82 extern wait_queue_head_t request_key_conswq; 83 84 85 extern struct key_type *key_type_lookup(const char *type); 86 extern void key_type_put(struct key_type *ktype); 87 88 extern int __key_link(struct key *keyring, struct key *key); 89 90 extern key_ref_t __keyring_search_one(key_ref_t keyring_ref, 91 const struct key_type *type, 92 const char *description, 93 key_perm_t perm); 94 95 extern struct key *keyring_search_instkey(struct key *keyring, 96 key_serial_t target_id); 97 98 typedef int (*key_match_func_t)(const struct key *, const void *); 99 100 extern key_ref_t keyring_search_aux(key_ref_t keyring_ref, 101 const struct cred *cred, 102 struct key_type *type, 103 const void *description, 104 key_match_func_t match); 105 106 extern key_ref_t search_process_keyrings(struct key_type *type, 107 const void *description, 108 key_match_func_t match, 109 const struct cred *cred); 110 111 extern struct key *find_keyring_by_name(const char *name, bool skip_perm_check); 112 113 extern int install_user_keyrings(void); 114 extern int install_thread_keyring_to_cred(struct cred *); 115 extern int install_process_keyring_to_cred(struct cred *); 116 117 extern struct key *request_key_and_link(struct key_type *type, 118 const char *description, 119 const void *callout_info, 120 size_t callout_len, 121 void *aux, 122 struct key *dest_keyring, 123 unsigned long flags); 124 125 extern key_ref_t lookup_user_key(key_serial_t id, int create, int partial, 126 key_perm_t perm); 127 128 extern long join_session_keyring(const char *name); 129 130 /* 131 * check to see whether permission is granted to use a key in the desired way 132 */ 133 extern int key_task_permission(const key_ref_t key_ref, 134 const struct cred *cred, 135 key_perm_t perm); 136 137 static inline int key_permission(const key_ref_t key_ref, key_perm_t perm) 138 { 139 return key_task_permission(key_ref, current_cred(), perm); 140 } 141 142 /* required permissions */ 143 #define KEY_VIEW 0x01 /* require permission to view attributes */ 144 #define KEY_READ 0x02 /* require permission to read content */ 145 #define KEY_WRITE 0x04 /* require permission to update / modify */ 146 #define KEY_SEARCH 0x08 /* require permission to search (keyring) or find (key) */ 147 #define KEY_LINK 0x10 /* require permission to link */ 148 #define KEY_SETATTR 0x20 /* require permission to change attributes */ 149 #define KEY_ALL 0x3f /* all the above permissions */ 150 151 /* 152 * request_key authorisation 153 */ 154 struct request_key_auth { 155 struct key *target_key; 156 struct key *dest_keyring; 157 const struct cred *cred; 158 void *callout_info; 159 size_t callout_len; 160 pid_t pid; 161 }; 162 163 extern struct key_type key_type_request_key_auth; 164 extern struct key *request_key_auth_new(struct key *target, 165 const void *callout_info, 166 size_t callout_len, 167 struct key *dest_keyring); 168 169 extern struct key *key_get_instantiation_authkey(key_serial_t target_id); 170 171 /* 172 * keyctl functions 173 */ 174 extern long keyctl_get_keyring_ID(key_serial_t, int); 175 extern long keyctl_join_session_keyring(const char __user *); 176 extern long keyctl_update_key(key_serial_t, const void __user *, size_t); 177 extern long keyctl_revoke_key(key_serial_t); 178 extern long keyctl_keyring_clear(key_serial_t); 179 extern long keyctl_keyring_link(key_serial_t, key_serial_t); 180 extern long keyctl_keyring_unlink(key_serial_t, key_serial_t); 181 extern long keyctl_describe_key(key_serial_t, char __user *, size_t); 182 extern long keyctl_keyring_search(key_serial_t, const char __user *, 183 const char __user *, key_serial_t); 184 extern long keyctl_read_key(key_serial_t, char __user *, size_t); 185 extern long keyctl_chown_key(key_serial_t, uid_t, gid_t); 186 extern long keyctl_setperm_key(key_serial_t, key_perm_t); 187 extern long keyctl_instantiate_key(key_serial_t, const void __user *, 188 size_t, key_serial_t); 189 extern long keyctl_negate_key(key_serial_t, unsigned, key_serial_t); 190 extern long keyctl_set_reqkey_keyring(int); 191 extern long keyctl_set_timeout(key_serial_t, unsigned); 192 extern long keyctl_assume_authority(key_serial_t); 193 extern long keyctl_get_security(key_serial_t keyid, char __user *buffer, 194 size_t buflen); 195 196 /* 197 * debugging key validation 198 */ 199 #ifdef KEY_DEBUGGING 200 extern void __key_check(const struct key *); 201 202 static inline void key_check(const struct key *key) 203 { 204 if (key && (IS_ERR(key) || key->magic != KEY_DEBUG_MAGIC)) 205 __key_check(key); 206 } 207 208 #else 209 210 #define key_check(key) do {} while(0) 211 212 #endif 213 214 #endif /* _INTERNAL_H */ 215