1 /* procfs files for key database enumeration 2 * 3 * Copyright (C) 2004 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 #include <linux/module.h> 13 #include <linux/init.h> 14 #include <linux/sched.h> 15 #include <linux/fs.h> 16 #include <linux/proc_fs.h> 17 #include <linux/seq_file.h> 18 #include <asm/errno.h> 19 #include "internal.h" 20 21 static int proc_keys_open(struct inode *inode, struct file *file); 22 static void *proc_keys_start(struct seq_file *p, loff_t *_pos); 23 static void *proc_keys_next(struct seq_file *p, void *v, loff_t *_pos); 24 static void proc_keys_stop(struct seq_file *p, void *v); 25 static int proc_keys_show(struct seq_file *m, void *v); 26 27 static const struct seq_operations proc_keys_ops = { 28 .start = proc_keys_start, 29 .next = proc_keys_next, 30 .stop = proc_keys_stop, 31 .show = proc_keys_show, 32 }; 33 34 static const struct file_operations proc_keys_fops = { 35 .open = proc_keys_open, 36 .read = seq_read, 37 .llseek = seq_lseek, 38 .release = seq_release, 39 }; 40 41 static int proc_key_users_open(struct inode *inode, struct file *file); 42 static void *proc_key_users_start(struct seq_file *p, loff_t *_pos); 43 static void *proc_key_users_next(struct seq_file *p, void *v, loff_t *_pos); 44 static void proc_key_users_stop(struct seq_file *p, void *v); 45 static int proc_key_users_show(struct seq_file *m, void *v); 46 47 static const struct seq_operations proc_key_users_ops = { 48 .start = proc_key_users_start, 49 .next = proc_key_users_next, 50 .stop = proc_key_users_stop, 51 .show = proc_key_users_show, 52 }; 53 54 static const struct file_operations proc_key_users_fops = { 55 .open = proc_key_users_open, 56 .read = seq_read, 57 .llseek = seq_lseek, 58 .release = seq_release, 59 }; 60 61 /* 62 * Declare the /proc files. 63 */ 64 static int __init key_proc_init(void) 65 { 66 struct proc_dir_entry *p; 67 68 p = proc_create("keys", 0, NULL, &proc_keys_fops); 69 if (!p) 70 panic("Cannot create /proc/keys\n"); 71 72 p = proc_create("key-users", 0, NULL, &proc_key_users_fops); 73 if (!p) 74 panic("Cannot create /proc/key-users\n"); 75 76 return 0; 77 } 78 79 __initcall(key_proc_init); 80 81 /* 82 * Implement "/proc/keys" to provide a list of the keys on the system that 83 * grant View permission to the caller. 84 */ 85 static struct rb_node *key_serial_next(struct seq_file *p, struct rb_node *n) 86 { 87 struct user_namespace *user_ns = seq_user_ns(p); 88 89 n = rb_next(n); 90 while (n) { 91 struct key *key = rb_entry(n, struct key, serial_node); 92 if (kuid_has_mapping(user_ns, key->user->uid)) 93 break; 94 n = rb_next(n); 95 } 96 return n; 97 } 98 99 static int proc_keys_open(struct inode *inode, struct file *file) 100 { 101 return seq_open(file, &proc_keys_ops); 102 } 103 104 static struct key *find_ge_key(struct seq_file *p, key_serial_t id) 105 { 106 struct user_namespace *user_ns = seq_user_ns(p); 107 struct rb_node *n = key_serial_tree.rb_node; 108 struct key *minkey = NULL; 109 110 while (n) { 111 struct key *key = rb_entry(n, struct key, serial_node); 112 if (id < key->serial) { 113 if (!minkey || minkey->serial > key->serial) 114 minkey = key; 115 n = n->rb_left; 116 } else if (id > key->serial) { 117 n = n->rb_right; 118 } else { 119 minkey = key; 120 break; 121 } 122 key = NULL; 123 } 124 125 if (!minkey) 126 return NULL; 127 128 for (;;) { 129 if (kuid_has_mapping(user_ns, minkey->user->uid)) 130 return minkey; 131 n = rb_next(&minkey->serial_node); 132 if (!n) 133 return NULL; 134 minkey = rb_entry(n, struct key, serial_node); 135 } 136 } 137 138 static void *proc_keys_start(struct seq_file *p, loff_t *_pos) 139 __acquires(key_serial_lock) 140 { 141 key_serial_t pos = *_pos; 142 struct key *key; 143 144 spin_lock(&key_serial_lock); 145 146 if (*_pos > INT_MAX) 147 return NULL; 148 key = find_ge_key(p, pos); 149 if (!key) 150 return NULL; 151 *_pos = key->serial; 152 return &key->serial_node; 153 } 154 155 static inline key_serial_t key_node_serial(struct rb_node *n) 156 { 157 struct key *key = rb_entry(n, struct key, serial_node); 158 return key->serial; 159 } 160 161 static void *proc_keys_next(struct seq_file *p, void *v, loff_t *_pos) 162 { 163 struct rb_node *n; 164 165 n = key_serial_next(p, v); 166 if (n) 167 *_pos = key_node_serial(n); 168 return n; 169 } 170 171 static void proc_keys_stop(struct seq_file *p, void *v) 172 __releases(key_serial_lock) 173 { 174 spin_unlock(&key_serial_lock); 175 } 176 177 static int proc_keys_show(struct seq_file *m, void *v) 178 { 179 struct rb_node *_p = v; 180 struct key *key = rb_entry(_p, struct key, serial_node); 181 struct timespec now; 182 time_t expiry; 183 unsigned long timo; 184 unsigned long flags; 185 key_ref_t key_ref, skey_ref; 186 char xbuf[16]; 187 short state; 188 int rc; 189 190 struct keyring_search_context ctx = { 191 .index_key.type = key->type, 192 .index_key.description = key->description, 193 .cred = m->file->f_cred, 194 .match_data.cmp = lookup_user_key_possessed, 195 .match_data.raw_data = key, 196 .match_data.lookup_type = KEYRING_SEARCH_LOOKUP_DIRECT, 197 .flags = KEYRING_SEARCH_NO_STATE_CHECK, 198 }; 199 200 key_ref = make_key_ref(key, 0); 201 202 /* determine if the key is possessed by this process (a test we can 203 * skip if the key does not indicate the possessor can view it 204 */ 205 if (key->perm & KEY_POS_VIEW) { 206 skey_ref = search_my_process_keyrings(&ctx); 207 if (!IS_ERR(skey_ref)) { 208 key_ref_put(skey_ref); 209 key_ref = make_key_ref(key, 1); 210 } 211 } 212 213 /* check whether the current task is allowed to view the key */ 214 rc = key_task_permission(key_ref, ctx.cred, KEY_NEED_VIEW); 215 if (rc < 0) 216 return 0; 217 218 now = current_kernel_time(); 219 220 rcu_read_lock(); 221 222 /* come up with a suitable timeout value */ 223 expiry = READ_ONCE(key->expiry); 224 if (expiry == 0) { 225 memcpy(xbuf, "perm", 5); 226 } else if (now.tv_sec >= expiry) { 227 memcpy(xbuf, "expd", 5); 228 } else { 229 timo = expiry - now.tv_sec; 230 231 if (timo < 60) 232 sprintf(xbuf, "%lus", timo); 233 else if (timo < 60*60) 234 sprintf(xbuf, "%lum", timo / 60); 235 else if (timo < 60*60*24) 236 sprintf(xbuf, "%luh", timo / (60*60)); 237 else if (timo < 60*60*24*7) 238 sprintf(xbuf, "%lud", timo / (60*60*24)); 239 else 240 sprintf(xbuf, "%luw", timo / (60*60*24*7)); 241 } 242 243 state = key_read_state(key); 244 245 #define showflag(FLAGS, LETTER, FLAG) \ 246 ((FLAGS & (1 << FLAG)) ? LETTER : '-') 247 248 flags = READ_ONCE(key->flags); 249 seq_printf(m, "%08x %c%c%c%c%c%c%c %5d %4s %08x %5d %5d %-9.9s ", 250 key->serial, 251 state != KEY_IS_UNINSTANTIATED ? 'I' : '-', 252 showflag(flags, 'R', KEY_FLAG_REVOKED), 253 showflag(flags, 'D', KEY_FLAG_DEAD), 254 showflag(flags, 'Q', KEY_FLAG_IN_QUOTA), 255 showflag(flags, 'U', KEY_FLAG_USER_CONSTRUCT), 256 state < 0 ? 'N' : '-', 257 showflag(flags, 'i', KEY_FLAG_INVALIDATED), 258 refcount_read(&key->usage), 259 xbuf, 260 key->perm, 261 from_kuid_munged(seq_user_ns(m), key->uid), 262 from_kgid_munged(seq_user_ns(m), key->gid), 263 key->type->name); 264 265 #undef showflag 266 267 if (key->type->describe) 268 key->type->describe(key, m); 269 seq_putc(m, '\n'); 270 271 rcu_read_unlock(); 272 return 0; 273 } 274 275 static struct rb_node *__key_user_next(struct user_namespace *user_ns, struct rb_node *n) 276 { 277 while (n) { 278 struct key_user *user = rb_entry(n, struct key_user, node); 279 if (kuid_has_mapping(user_ns, user->uid)) 280 break; 281 n = rb_next(n); 282 } 283 return n; 284 } 285 286 static struct rb_node *key_user_next(struct user_namespace *user_ns, struct rb_node *n) 287 { 288 return __key_user_next(user_ns, rb_next(n)); 289 } 290 291 static struct rb_node *key_user_first(struct user_namespace *user_ns, struct rb_root *r) 292 { 293 struct rb_node *n = rb_first(r); 294 return __key_user_next(user_ns, n); 295 } 296 297 /* 298 * Implement "/proc/key-users" to provides a list of the key users and their 299 * quotas. 300 */ 301 static int proc_key_users_open(struct inode *inode, struct file *file) 302 { 303 return seq_open(file, &proc_key_users_ops); 304 } 305 306 static void *proc_key_users_start(struct seq_file *p, loff_t *_pos) 307 __acquires(key_user_lock) 308 { 309 struct rb_node *_p; 310 loff_t pos = *_pos; 311 312 spin_lock(&key_user_lock); 313 314 _p = key_user_first(seq_user_ns(p), &key_user_tree); 315 while (pos > 0 && _p) { 316 pos--; 317 _p = key_user_next(seq_user_ns(p), _p); 318 } 319 320 return _p; 321 } 322 323 static void *proc_key_users_next(struct seq_file *p, void *v, loff_t *_pos) 324 { 325 (*_pos)++; 326 return key_user_next(seq_user_ns(p), (struct rb_node *)v); 327 } 328 329 static void proc_key_users_stop(struct seq_file *p, void *v) 330 __releases(key_user_lock) 331 { 332 spin_unlock(&key_user_lock); 333 } 334 335 static int proc_key_users_show(struct seq_file *m, void *v) 336 { 337 struct rb_node *_p = v; 338 struct key_user *user = rb_entry(_p, struct key_user, node); 339 unsigned maxkeys = uid_eq(user->uid, GLOBAL_ROOT_UID) ? 340 key_quota_root_maxkeys : key_quota_maxkeys; 341 unsigned maxbytes = uid_eq(user->uid, GLOBAL_ROOT_UID) ? 342 key_quota_root_maxbytes : key_quota_maxbytes; 343 344 seq_printf(m, "%5u: %5d %d/%d %d/%d %d/%d\n", 345 from_kuid_munged(seq_user_ns(m), user->uid), 346 refcount_read(&user->usage), 347 atomic_read(&user->nkeys), 348 atomic_read(&user->nikeys), 349 user->qnkeys, 350 maxkeys, 351 user->qnbytes, 352 maxbytes); 353 354 return 0; 355 } 356