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 int proc_keys_open(struct inode *inode, struct file *file)
  95 {
  96         return seq_open(file, &proc_keys_ops);
  97
  98 }
  99
 100 static void *proc_keys_start(struct seq_file *p, loff_t *_pos)
 101 {
 102         struct rb_node *_p;
 103         loff_t pos = *_pos;
 104
 105         spin_lock(&key_serial_lock);
 106
 107         _p = rb_first(&key_serial_tree);
 108         while (pos > 0 && _p) {
 109                 pos--;
 110                 _p = rb_next(_p);
 111         }
 112
 113         return _p;
 114
 115 }
 116
 117 static void *proc_keys_next(struct seq_file *p, void *v, loff_t *_pos)
 118 {
 119         (*_pos)++;
 120         return rb_next((struct rb_node *) v);
 121
 122 }
 123
 124 static void proc_keys_stop(struct seq_file *p, void *v)
 125 {
 126         spin_unlock(&key_serial_lock);
 127 }
 128
 129 static int proc_keys_show(struct seq_file *m, void *v)
 130 {
 131         struct rb_node *_p = v;
 132         struct key *key = rb_entry(_p, struct key, serial_node);
 133         struct timespec now;
 134         unsigned long timo;
 135         char xbuf[12];
 136         int rc;
 137
 138         /* check whether the current task is allowed to view the key (assuming
 139          * non-possession)
 140          * - the caller holds a spinlock, and thus the RCU read lock, making our
 141          *   access to __current_cred() safe
 142          */
 143         rc = key_task_permission(make_key_ref(key, 0), current_cred(),
 144                                  KEY_VIEW);
 145         if (rc < 0)
 146                 return 0;
 147
 148         now = current_kernel_time();
 149
 150         rcu_read_lock();
 151
 152         /* come up with a suitable timeout value */
 153         if (key->expiry == 0) {
 154                 memcpy(xbuf, "perm", 5);
 155         }
 156         else if (now.tv_sec >= key->expiry) {
 157                 memcpy(xbuf, "expd", 5);
 158         }
 159         else {
 160                 timo = key->expiry - now.tv_sec;
 161
 162                 if (timo < 60)
 163                         sprintf(xbuf, "%lus", timo);
 164                 else if (timo < 60*60)
 165                         sprintf(xbuf, "%lum", timo / 60);
 166                 else if (timo < 60*60*24)
 167                         sprintf(xbuf, "%luh", timo / (60*60));
 168                 else if (timo < 60*60*24*7)
 169                         sprintf(xbuf, "%lud", timo / (60*60*24));
 170                 else
 171                         sprintf(xbuf, "%luw", timo / (60*60*24*7));
 172         }
 173
 174 #define showflag(KEY, LETTER, FLAG) \
 175         (test_bit(FLAG, &(KEY)->flags) ? LETTER : '-')
 176
 177         seq_printf(m, "%08x %c%c%c%c%c%c %5d %4s %08x %5d %5d %-9.9s ",
 178                    key->serial,
 179                    showflag(key, 'I', KEY_FLAG_INSTANTIATED),
 180                    showflag(key, 'R', KEY_FLAG_REVOKED),
 181                    showflag(key, 'D', KEY_FLAG_DEAD),
 182                    showflag(key, 'Q', KEY_FLAG_IN_QUOTA),
 183                    showflag(key, 'U', KEY_FLAG_USER_CONSTRUCT),
 184                    showflag(key, 'N', KEY_FLAG_NEGATIVE),
 185                    atomic_read(&key->usage),
 186                    xbuf,
 187                    key->perm,
 188                    key->uid,
 189                    key->gid,
 190                    key->type->name);
 191
 192 #undef showflag
 193
 194         if (key->type->describe)
 195                 key->type->describe(key, m);
 196         seq_putc(m, '\n');
 197
 198         rcu_read_unlock();
 199
 200         return 0;
 201
 202 }
 203
 204 #endif /* CONFIG_KEYS_DEBUG_PROC_KEYS */
 205
 206 /*****************************************************************************/
 207 /*
 208  * implement "/proc/key-users" to provides a list of the key users
 209  */
 210 static int proc_key_users_open(struct inode *inode, struct file *file)
 211 {
 212         return seq_open(file, &proc_key_users_ops);
 213
 214 }
 215
 216 static void *proc_key_users_start(struct seq_file *p, loff_t *_pos)
 217 {
 218         struct rb_node *_p;
 219         loff_t pos = *_pos;
 220
 221         spin_lock(&key_user_lock);
 222
 223         _p = rb_first(&key_user_tree);
 224         while (pos > 0 && _p) {
 225                 pos--;
 226                 _p = rb_next(_p);
 227         }
 228
 229         return _p;
 230
 231 }
 232
 233 static void *proc_key_users_next(struct seq_file *p, void *v, loff_t *_pos)
 234 {
 235         (*_pos)++;
 236         return rb_next((struct rb_node *) v);
 237
 238 }
 239
 240 static void proc_key_users_stop(struct seq_file *p, void *v)
 241 {
 242         spin_unlock(&key_user_lock);
 243 }
 244
 245 static int proc_key_users_show(struct seq_file *m, void *v)
 246 {
 247         struct rb_node *_p = v;
 248         struct key_user *user = rb_entry(_p, struct key_user, node);
 249         unsigned maxkeys = (user->uid == 0) ?
 250                 key_quota_root_maxkeys : key_quota_maxkeys;
 251         unsigned maxbytes = (user->uid == 0) ?
 252                 key_quota_root_maxbytes : key_quota_maxbytes;
 253
 254         seq_printf(m, "%5u: %5d %d/%d %d/%d %d/%d\n",
 255                    user->uid,
 256                    atomic_read(&user->usage),
 257                    atomic_read(&user->nkeys),
 258                    atomic_read(&user->nikeys),
 259                    user->qnkeys,
 260                    maxkeys,
 261                    user->qnbytes,
 262                    maxbytes);
 263
 264         return 0;
 265
 266 }