security/keys/proc.c

   1 /* proc.c: proc 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/slab.h>
  16 #include <linux/fs.h>
  17 #include <linux/proc_fs.h>
  18 #include <linux/seq_file.h>
  19 #include <asm/errno.h>
  20 #include "internal.h"
  21
  22 #ifdef CONFIG_KEYS_DEBUG_PROC_KEYS
  23 static int proc_keys_open(struct inode *inode, struct file *file);
  24 static void *proc_keys_start(struct seq_file *p, loff_t *_pos);
  25 static void *proc_keys_next(struct seq_file *p, void *v, loff_t *_pos);
  26 static void proc_keys_stop(struct seq_file *p, void *v);
  27 static int proc_keys_show(struct seq_file *m, void *v);
  28
  29 static const struct seq_operations proc_keys_ops = {
  30         .start  = proc_keys_start,
  31         .next   = proc_keys_next,
  32         .stop   = proc_keys_stop,
  33         .show   = proc_keys_show,
  34 };
  35
  36 static const struct file_operations proc_keys_fops = {
  37         .open           = proc_keys_open,
  38         .read           = seq_read,
  39         .llseek         = seq_lseek,
  40         .release        = seq_release,
  41 };
  42 #endif
  43
  44 static int proc_key_users_open(struct inode *inode, struct file *file);
  45 static void *proc_key_users_start(struct seq_file *p, loff_t *_pos);
  46 static void *proc_key_users_next(struct seq_file *p, void *v, loff_t *_pos);
  47 static void proc_key_users_stop(struct seq_file *p, void *v);
  48 static int proc_key_users_show(struct seq_file *m, void *v);
  49
  50 static const struct seq_operations proc_key_users_ops = {
  51         .start  = proc_key_users_start,
  52         .next   = proc_key_users_next,
  53         .stop   = proc_key_users_stop,
  54         .show   = proc_key_users_show,
  55 };
  56
  57 static const struct file_operations proc_key_users_fops = {
  58         .open           = proc_key_users_open,
  59         .read           = seq_read,
  60         .llseek         = seq_lseek,
  61         .release        = seq_release,
  62 };
  63
  64 /*****************************************************************************/
  65 /*
  66  * declare the /proc files
  67  */
  68 static int __init key_proc_init(void)
  69 {
  70         struct proc_dir_entry *p;
  71
  72 #ifdef CONFIG_KEYS_DEBUG_PROC_KEYS
  73         p = proc_create("keys", 0, NULL, &proc_keys_fops);
  74         if (!p)
  75                 panic("Cannot create /proc/keys\n");
  76 #endif
  77
  78         p = proc_create("key-users", 0, NULL, &proc_key_users_fops);
  79         if (!p)
  80                 panic("Cannot create /proc/key-users\n");
  81
  82         return 0;
  83
  84 } /* end key_proc_init() */
  85
  86 __initcall(key_proc_init);
  87
  88 /*****************************************************************************/
  89 /*
  90  * implement "/proc/keys" to provides a list of the keys on the system
  91  */
  92 #ifdef CONFIG_KEYS_DEBUG_PROC_KEYS
  93
  94 static struct rb_node *__key_serial_next(struct rb_node *n)
  95 {
  96         while (n) {
  97                 struct key *key = rb_entry(n, struct key, serial_node);
  98                 if (key->user->user_ns == current_user_ns())
  99                         break;
 100                 n = rb_next(n);
 101         }
 102         return n;
 103 }
 104
 105 static struct rb_node *key_serial_next(struct rb_node *n)
 106 {
 107         return __key_serial_next(rb_next(n));
 108 }
 109
 110 static struct rb_node *key_serial_first(struct rb_root *r)
 111 {
 112         struct rb_node *n = rb_first(r);
 113         return __key_serial_next(n);
 114 }
 115
 116 static int proc_keys_open(struct inode *inode, struct file *file)
 117 {
 118         return seq_open(file, &proc_keys_ops);
 119
 120 }
 121
 122 static void *proc_keys_start(struct seq_file *p, loff_t *_pos)
 123 {
 124         struct rb_node *_p;
 125         loff_t pos = *_pos;
 126
 127         spin_lock(&key_serial_lock);
 128
 129         _p = key_serial_first(&key_serial_tree);
 130         while (pos > 0 && _p) {
 131                 pos--;
 132                 _p = key_serial_next(_p);
 133         }
 134
 135         return _p;
 136
 137 }
 138
 139 static void *proc_keys_next(struct seq_file *p, void *v, loff_t *_pos)
 140 {
 141         (*_pos)++;
 142         return key_serial_next((struct rb_node *) v);
 143
 144 }
 145
 146 static void proc_keys_stop(struct seq_file *p, void *v)
 147 {
 148         spin_unlock(&key_serial_lock);
 149 }
 150
 151 static int proc_keys_show(struct seq_file *m, void *v)
 152 {
 153         struct rb_node *_p = v;
 154         struct key *key = rb_entry(_p, struct key, serial_node);
 155         struct timespec now;
 156         unsigned long timo;
 157         char xbuf[12];
 158         int rc;
 159
 160         /* check whether the current task is allowed to view the key (assuming
 161          * non-possession)
 162          * - the caller holds a spinlock, and thus the RCU read lock, making our
 163          *   access to __current_cred() safe
 164          */
 165         rc = key_task_permission(make_key_ref(key, 0), current_cred(),
 166                                  KEY_VIEW);
 167         if (rc < 0)
 168                 return 0;
 169
 170         now = current_kernel_time();
 171
 172         rcu_read_lock();
 173
 174         /* come up with a suitable timeout value */
 175         if (key->expiry == 0) {
 176                 memcpy(xbuf, "perm", 5);
 177         }
 178         else if (now.tv_sec >= key->expiry) {
 179                 memcpy(xbuf, "expd", 5);
 180         }
 181         else {
 182                 timo = key->expiry - now.tv_sec;
 183
 184                 if (timo < 60)
 185                         sprintf(xbuf, "%lus", timo);
 186                 else if (timo < 60*60)
 187                         sprintf(xbuf, "%lum", timo / 60);
 188                 else if (timo < 60*60*24)
 189                         sprintf(xbuf, "%luh", timo / (60*60));
 190                 else if (timo < 60*60*24*7)
 191                         sprintf(xbuf, "%lud", timo / (60*60*24));
 192                 else
 193                         sprintf(xbuf, "%luw", timo / (60*60*24*7));
 194         }
 195
 196 #define showflag(KEY, LETTER, FLAG) \
 197         (test_bit(FLAG, &(KEY)->flags) ? LETTER : '-')
 198
 199         seq_printf(m, "%08x %c%c%c%c%c%c %5d %4s %08x %5d %5d %-9.9s ",
 200                    key->serial,
 201                    showflag(key, 'I', KEY_FLAG_INSTANTIATED),
 202                    showflag(key, 'R', KEY_FLAG_REVOKED),
 203                    showflag(key, 'D', KEY_FLAG_DEAD),
 204                    showflag(key, 'Q', KEY_FLAG_IN_QUOTA),
 205                    showflag(key, 'U', KEY_FLAG_USER_CONSTRUCT),
 206                    showflag(key, 'N', KEY_FLAG_NEGATIVE),
 207                    atomic_read(&key->usage),
 208                    xbuf,
 209                    key->perm,
 210                    key->uid,
 211                    key->gid,
 212                    key->type->name);
 213
 214 #undef showflag
 215
 216         if (key->type->describe)
 217                 key->type->describe(key, m);
 218         seq_putc(m, '\n');
 219
 220         rcu_read_unlock();
 221
 222         return 0;
 223
 224 }
 225
 226 #endif /* CONFIG_KEYS_DEBUG_PROC_KEYS */
 227
 228 static struct rb_node *__key_user_next(struct rb_node *n)
 229 {
 230         while (n) {
 231                 struct key_user *user = rb_entry(n, struct key_user, node);
 232                 if (user->user_ns == current_user_ns())
 233                         break;
 234                 n = rb_next(n);
 235         }
 236         return n;
 237 }
 238
 239 static struct rb_node *key_user_next(struct rb_node *n)
 240 {
 241         return __key_user_next(rb_next(n));
 242 }
 243
 244 static struct rb_node *key_user_first(struct rb_root *r)
 245 {
 246         struct rb_node *n = rb_first(r);
 247         return __key_user_next(n);
 248 }
 249 /*****************************************************************************/
 250 /*
 251  * implement "/proc/key-users" to provides a list of the key users
 252  */
 253 static int proc_key_users_open(struct inode *inode, struct file *file)
 254 {
 255         return seq_open(file, &proc_key_users_ops);
 256
 257 }
 258
 259 static void *proc_key_users_start(struct seq_file *p, loff_t *_pos)
 260 {
 261         struct rb_node *_p;
 262         loff_t pos = *_pos;
 263
 264         spin_lock(&key_user_lock);
 265
 266         _p = key_user_first(&key_user_tree);
 267         while (pos > 0 && _p) {
 268                 pos--;
 269                 _p = key_user_next(_p);
 270         }
 271
 272         return _p;
 273
 274 }
 275
 276 static void *proc_key_users_next(struct seq_file *p, void *v, loff_t *_pos)
 277 {
 278         (*_pos)++;
 279         return key_user_next((struct rb_node *) v);
 280
 281 }
 282
 283 static void proc_key_users_stop(struct seq_file *p, void *v)
 284 {
 285         spin_unlock(&key_user_lock);
 286 }
 287
 288 static int proc_key_users_show(struct seq_file *m, void *v)
 289 {
 290         struct rb_node *_p = v;
 291         struct key_user *user = rb_entry(_p, struct key_user, node);
 292         unsigned maxkeys = (user->uid == 0) ?
 293                 key_quota_root_maxkeys : key_quota_maxkeys;
 294         unsigned maxbytes = (user->uid == 0) ?
 295                 key_quota_root_maxbytes : key_quota_maxbytes;
 296
 297         seq_printf(m, "%5u: %5d %d/%d %d/%d %d/%d\n",
 298                    user->uid,
 299                    atomic_read(&user->usage),
 300                    atomic_read(&user->nkeys),
 301                    atomic_read(&user->nikeys),
 302                    user->qnkeys,
 303                    maxkeys,
 304                    user->qnbytes,
 305                    maxbytes);
 306
 307         return 0;
 308
 309 }