linux/security/keys/proc.c
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   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
  23static int proc_keys_open(struct inode *inode, struct file *file);
  24static void *proc_keys_start(struct seq_file *p, loff_t *_pos);
  25static void *proc_keys_next(struct seq_file *p, void *v, loff_t *_pos);
  26static void proc_keys_stop(struct seq_file *p, void *v);
  27static int proc_keys_show(struct seq_file *m, void *v);
  28
  29static 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
  36static 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
  44static int proc_key_users_open(struct inode *inode, struct file *file);
  45static void *proc_key_users_start(struct seq_file *p, loff_t *_pos);
  46static void *proc_key_users_next(struct seq_file *p, void *v, loff_t *_pos);
  47static void proc_key_users_stop(struct seq_file *p, void *v);
  48static int proc_key_users_show(struct seq_file *m, void *v);
  49
  50static 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
  57static 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 */
  68static 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
  94static int proc_keys_open(struct inode *inode, struct file *file)
  95{
  96        return seq_open(file, &proc_keys_ops);
  97
  98}
  99
 100static 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
 117static 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
 124static void proc_keys_stop(struct seq_file *p, void *v)
 125{
 126        spin_unlock(&key_serial_lock);
 127}
 128
 129static 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        rc = key_task_permission(make_key_ref(key, 0), current, KEY_VIEW);
 141        if (rc < 0)
 142                return 0;
 143
 144        now = current_kernel_time();
 145
 146        rcu_read_lock();
 147
 148        /* come up with a suitable timeout value */
 149        if (key->expiry == 0) {
 150                memcpy(xbuf, "perm", 5);
 151        }
 152        else if (now.tv_sec >= key->expiry) {
 153                memcpy(xbuf, "expd", 5);
 154        }
 155        else {
 156                timo = key->expiry - now.tv_sec;
 157
 158                if (timo < 60)
 159                        sprintf(xbuf, "%lus", timo);
 160                else if (timo < 60*60)
 161                        sprintf(xbuf, "%lum", timo / 60);
 162                else if (timo < 60*60*24)
 163                        sprintf(xbuf, "%luh", timo / (60*60));
 164                else if (timo < 60*60*24*7)
 165                        sprintf(xbuf, "%lud", timo / (60*60*24));
 166                else
 167                        sprintf(xbuf, "%luw", timo / (60*60*24*7));
 168        }
 169
 170#define showflag(KEY, LETTER, FLAG) \
 171        (test_bit(FLAG, &(KEY)->flags) ? LETTER : '-')
 172
 173        seq_printf(m, "%08x %c%c%c%c%c%c %5d %4s %08x %5d %5d %-9.9s ",
 174                   key->serial,
 175                   showflag(key, 'I', KEY_FLAG_INSTANTIATED),
 176                   showflag(key, 'R', KEY_FLAG_REVOKED),
 177                   showflag(key, 'D', KEY_FLAG_DEAD),
 178                   showflag(key, 'Q', KEY_FLAG_IN_QUOTA),
 179                   showflag(key, 'U', KEY_FLAG_USER_CONSTRUCT),
 180                   showflag(key, 'N', KEY_FLAG_NEGATIVE),
 181                   atomic_read(&key->usage),
 182                   xbuf,
 183                   key->perm,
 184                   key->uid,
 185                   key->gid,
 186                   key->type->name);
 187
 188#undef showflag
 189
 190        if (key->type->describe)
 191                key->type->describe(key, m);
 192        seq_putc(m, '\n');
 193
 194        rcu_read_unlock();
 195
 196        return 0;
 197
 198}
 199
 200#endif /* CONFIG_KEYS_DEBUG_PROC_KEYS */
 201
 202/*****************************************************************************/
 203/*
 204 * implement "/proc/key-users" to provides a list of the key users
 205 */
 206static int proc_key_users_open(struct inode *inode, struct file *file)
 207{
 208        return seq_open(file, &proc_key_users_ops);
 209
 210}
 211
 212static void *proc_key_users_start(struct seq_file *p, loff_t *_pos)
 213{
 214        struct rb_node *_p;
 215        loff_t pos = *_pos;
 216
 217        spin_lock(&key_user_lock);
 218
 219        _p = rb_first(&key_user_tree);
 220        while (pos > 0 && _p) {
 221                pos--;
 222                _p = rb_next(_p);
 223        }
 224
 225        return _p;
 226
 227}
 228
 229static void *proc_key_users_next(struct seq_file *p, void *v, loff_t *_pos)
 230{
 231        (*_pos)++;
 232        return rb_next((struct rb_node *) v);
 233
 234}
 235
 236static void proc_key_users_stop(struct seq_file *p, void *v)
 237{
 238        spin_unlock(&key_user_lock);
 239}
 240
 241static int proc_key_users_show(struct seq_file *m, void *v)
 242{
 243        struct rb_node *_p = v;
 244        struct key_user *user = rb_entry(_p, struct key_user, node);
 245        unsigned maxkeys = (user->uid == 0) ?
 246                key_quota_root_maxkeys : key_quota_maxkeys;
 247        unsigned maxbytes = (user->uid == 0) ?
 248                key_quota_root_maxbytes : key_quota_maxbytes;
 249
 250        seq_printf(m, "%5u: %5d %d/%d %d/%d %d/%d\n",
 251                   user->uid,
 252                   atomic_read(&user->usage),
 253                   atomic_read(&user->nkeys),
 254                   atomic_read(&user->nikeys),
 255                   user->qnkeys,
 256                   maxkeys,
 257                   user->qnbytes,
 258                   maxbytes);
 259
 260        return 0;
 261
 262}
 263