| 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 | unsigned long timo; |
| 183 | key_ref_t key_ref, skey_ref; |
| 184 | char xbuf[12]; |
| 185 | int rc; |
| 186 | |
| 187 | struct keyring_search_context ctx = { |
| 188 | .index_key.type = key->type, |
| 189 | .index_key.description = key->description, |
| 190 | .cred = current_cred(), |
| 191 | .match_data.cmp = lookup_user_key_possessed, |
| 192 | .match_data.raw_data = key, |
| 193 | .match_data.lookup_type = KEYRING_SEARCH_LOOKUP_DIRECT, |
| 194 | .flags = KEYRING_SEARCH_NO_STATE_CHECK, |
| 195 | }; |
| 196 | |
| 197 | key_ref = make_key_ref(key, 0); |
| 198 | |
| 199 | /* determine if the key is possessed by this process (a test we can |
| 200 | * skip if the key does not indicate the possessor can view it |
| 201 | */ |
| 202 | if (key->perm & KEY_POS_VIEW) { |
| 203 | skey_ref = search_my_process_keyrings(&ctx); |
| 204 | if (!IS_ERR(skey_ref)) { |
| 205 | key_ref_put(skey_ref); |
| 206 | key_ref = make_key_ref(key, 1); |
| 207 | } |
| 208 | } |
| 209 | |
| 210 | /* check whether the current task is allowed to view the key (assuming |
| 211 | * non-possession) |
| 212 | * - the caller holds a spinlock, and thus the RCU read lock, making our |
| 213 | * access to __current_cred() safe |
| 214 | */ |
| 215 | rc = key_task_permission(key_ref, ctx.cred, KEY_NEED_VIEW); |
| 216 | if (rc < 0) |
| 217 | return 0; |
| 218 | |
| 219 | now = current_kernel_time(); |
| 220 | |
| 221 | rcu_read_lock(); |
| 222 | |
| 223 | /* come up with a suitable timeout value */ |
| 224 | if (key->expiry == 0) { |
| 225 | memcpy(xbuf, "perm", 5); |
| 226 | } else if (now.tv_sec >= key->expiry) { |
| 227 | memcpy(xbuf, "expd", 5); |
| 228 | } else { |
| 229 | timo = key->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 | #define showflag(KEY, LETTER, FLAG) \ |
| 244 | (test_bit(FLAG, &(KEY)->flags) ? LETTER : '-') |
| 245 | |
| 246 | seq_printf(m, "%08x %c%c%c%c%c%c%c %5d %4s %08x %5d %5d %-9.9s ", |
| 247 | key->serial, |
| 248 | showflag(key, 'I', KEY_FLAG_INSTANTIATED), |
| 249 | showflag(key, 'R', KEY_FLAG_REVOKED), |
| 250 | showflag(key, 'D', KEY_FLAG_DEAD), |
| 251 | showflag(key, 'Q', KEY_FLAG_IN_QUOTA), |
| 252 | showflag(key, 'U', KEY_FLAG_USER_CONSTRUCT), |
| 253 | showflag(key, 'N', KEY_FLAG_NEGATIVE), |
| 254 | showflag(key, 'i', KEY_FLAG_INVALIDATED), |
| 255 | atomic_read(&key->usage), |
| 256 | xbuf, |
| 257 | key->perm, |
| 258 | from_kuid_munged(seq_user_ns(m), key->uid), |
| 259 | from_kgid_munged(seq_user_ns(m), key->gid), |
| 260 | key->type->name); |
| 261 | |
| 262 | #undef showflag |
| 263 | |
| 264 | if (key->type->describe) |
| 265 | key->type->describe(key, m); |
| 266 | seq_putc(m, '\n'); |
| 267 | |
| 268 | rcu_read_unlock(); |
| 269 | return 0; |
| 270 | } |
| 271 | |
| 272 | static struct rb_node *__key_user_next(struct user_namespace *user_ns, struct rb_node *n) |
| 273 | { |
| 274 | while (n) { |
| 275 | struct key_user *user = rb_entry(n, struct key_user, node); |
| 276 | if (kuid_has_mapping(user_ns, user->uid)) |
| 277 | break; |
| 278 | n = rb_next(n); |
| 279 | } |
| 280 | return n; |
| 281 | } |
| 282 | |
| 283 | static struct rb_node *key_user_next(struct user_namespace *user_ns, struct rb_node *n) |
| 284 | { |
| 285 | return __key_user_next(user_ns, rb_next(n)); |
| 286 | } |
| 287 | |
| 288 | static struct rb_node *key_user_first(struct user_namespace *user_ns, struct rb_root *r) |
| 289 | { |
| 290 | struct rb_node *n = rb_first(r); |
| 291 | return __key_user_next(user_ns, n); |
| 292 | } |
| 293 | |
| 294 | /* |
| 295 | * Implement "/proc/key-users" to provides a list of the key users and their |
| 296 | * quotas. |
| 297 | */ |
| 298 | static int proc_key_users_open(struct inode *inode, struct file *file) |
| 299 | { |
| 300 | return seq_open(file, &proc_key_users_ops); |
| 301 | } |
| 302 | |
| 303 | static void *proc_key_users_start(struct seq_file *p, loff_t *_pos) |
| 304 | __acquires(key_user_lock) |
| 305 | { |
| 306 | struct rb_node *_p; |
| 307 | loff_t pos = *_pos; |
| 308 | |
| 309 | spin_lock(&key_user_lock); |
| 310 | |
| 311 | _p = key_user_first(seq_user_ns(p), &key_user_tree); |
| 312 | while (pos > 0 && _p) { |
| 313 | pos--; |
| 314 | _p = key_user_next(seq_user_ns(p), _p); |
| 315 | } |
| 316 | |
| 317 | return _p; |
| 318 | } |
| 319 | |
| 320 | static void *proc_key_users_next(struct seq_file *p, void *v, loff_t *_pos) |
| 321 | { |
| 322 | (*_pos)++; |
| 323 | return key_user_next(seq_user_ns(p), (struct rb_node *)v); |
| 324 | } |
| 325 | |
| 326 | static void proc_key_users_stop(struct seq_file *p, void *v) |
| 327 | __releases(key_user_lock) |
| 328 | { |
| 329 | spin_unlock(&key_user_lock); |
| 330 | } |
| 331 | |
| 332 | static int proc_key_users_show(struct seq_file *m, void *v) |
| 333 | { |
| 334 | struct rb_node *_p = v; |
| 335 | struct key_user *user = rb_entry(_p, struct key_user, node); |
| 336 | unsigned maxkeys = uid_eq(user->uid, GLOBAL_ROOT_UID) ? |
| 337 | key_quota_root_maxkeys : key_quota_maxkeys; |
| 338 | unsigned maxbytes = uid_eq(user->uid, GLOBAL_ROOT_UID) ? |
| 339 | key_quota_root_maxbytes : key_quota_maxbytes; |
| 340 | |
| 341 | seq_printf(m, "%5u: %5d %d/%d %d/%d %d/%d\n", |
| 342 | from_kuid_munged(seq_user_ns(m), user->uid), |
| 343 | atomic_read(&user->usage), |
| 344 | atomic_read(&user->nkeys), |
| 345 | atomic_read(&user->nikeys), |
| 346 | user->qnkeys, |
| 347 | maxkeys, |
| 348 | user->qnbytes, |
| 349 | maxbytes); |
| 350 | |
| 351 | return 0; |
| 352 | } |