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/* procfs files for key database enumeration
*
* Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/fs.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <asm/errno.h>
#include "internal.h"
static int proc_keys_open(struct inode *inode, struct file *file);
static void *proc_keys_start(struct seq_file *p, loff_t *_pos);
static void *proc_keys_next(struct seq_file *p, void *v, loff_t *_pos);
static void proc_keys_stop(struct seq_file *p, void *v);
static int proc_keys_show(struct seq_file *m, void *v);
static const struct seq_operations proc_keys_ops = {
.start = proc_keys_start,
.next = proc_keys_next,
.stop = proc_keys_stop,
.show = proc_keys_show,
};
static const struct file_operations proc_keys_fops = {
.open = proc_keys_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release,
};
static int proc_key_users_open(struct inode *inode, struct file *file);
static void *proc_key_users_start(struct seq_file *p, loff_t *_pos);
static void *proc_key_users_next(struct seq_file *p, void *v, loff_t *_pos);
static void proc_key_users_stop(struct seq_file *p, void *v);
static int proc_key_users_show(struct seq_file *m, void *v);
static const struct seq_operations proc_key_users_ops = {
.start = proc_key_users_start,
.next = proc_key_users_next,
.stop = proc_key_users_stop,
.show = proc_key_users_show,
};
static const struct file_operations proc_key_users_fops = {
.open = proc_key_users_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release,
};
/*
* Declare the /proc files.
*/
static int __init key_proc_init(void)
{
struct proc_dir_entry *p;
p = proc_create("keys", 0, NULL, &proc_keys_fops);
if (!p)
panic("Cannot create /proc/keys\n");
p = proc_create("key-users", 0, NULL, &proc_key_users_fops);
if (!p)
panic("Cannot create /proc/key-users\n");
return 0;
}
__initcall(key_proc_init);
/*
* Implement "/proc/keys" to provide a list of the keys on the system that
* grant View permission to the caller.
*/
static struct rb_node *key_serial_next(struct seq_file *p, struct rb_node *n)
{
struct user_namespace *user_ns = seq_user_ns(p);
n = rb_next(n);
while (n) {
struct key *key = rb_entry(n, struct key, serial_node);
if (kuid_has_mapping(user_ns, key->user->uid))
break;
n = rb_next(n);
}
return n;
}
static int proc_keys_open(struct inode *inode, struct file *file)
{
return seq_open(file, &proc_keys_ops);
}
static struct key *find_ge_key(struct seq_file *p, key_serial_t id)
{
struct user_namespace *user_ns = seq_user_ns(p);
struct rb_node *n = key_serial_tree.rb_node;
struct key *minkey = NULL;
while (n) {
struct key *key = rb_entry(n, struct key, serial_node);
if (id < key->serial) {
if (!minkey || minkey->serial > key->serial)
minkey = key;
n = n->rb_left;
} else if (id > key->serial) {
n = n->rb_right;
} else {
minkey = key;
break;
}
key = NULL;
}
if (!minkey)
return NULL;
for (;;) {
if (kuid_has_mapping(user_ns, minkey->user->uid))
return minkey;
n = rb_next(&minkey->serial_node);
if (!n)
return NULL;
minkey = rb_entry(n, struct key, serial_node);
}
}
static void *proc_keys_start(struct seq_file *p, loff_t *_pos)
__acquires(key_serial_lock)
{
key_serial_t pos = *_pos;
struct key *key;
spin_lock(&key_serial_lock);
if (*_pos > INT_MAX)
return NULL;
key = find_ge_key(p, pos);
if (!key)
return NULL;
*_pos = key->serial;
return &key->serial_node;
}
static inline key_serial_t key_node_serial(struct rb_node *n)
{
struct key *key = rb_entry(n, struct key, serial_node);
return key->serial;
}
static void *proc_keys_next(struct seq_file *p, void *v, loff_t *_pos)
{
struct rb_node *n;
n = key_serial_next(p, v);
if (n)
*_pos = key_node_serial(n);
return n;
}
static void proc_keys_stop(struct seq_file *p, void *v)
__releases(key_serial_lock)
{
spin_unlock(&key_serial_lock);
}
static int proc_keys_show(struct seq_file *m, void *v)
{
struct rb_node *_p = v;
struct key *key = rb_entry(_p, struct key, serial_node);
struct timespec now;
unsigned long timo;
key_ref_t key_ref, skey_ref;
char xbuf[16];
int rc;
struct keyring_search_context ctx = {
.index_key.type = key->type,
.index_key.description = key->description,
.cred = m->file->f_cred,
.match_data.cmp = lookup_user_key_possessed,
.match_data.raw_data = key,
.match_data.lookup_type = KEYRING_SEARCH_LOOKUP_DIRECT,
.flags = KEYRING_SEARCH_NO_STATE_CHECK,
};
key_ref = make_key_ref(key, 0);
/* determine if the key is possessed by this process (a test we can
* skip if the key does not indicate the possessor can view it
*/
if (key->perm & KEY_POS_VIEW) {
skey_ref = search_my_process_keyrings(&ctx);
if (!IS_ERR(skey_ref)) {
key_ref_put(skey_ref);
key_ref = make_key_ref(key, 1);
}
}
/* check whether the current task is allowed to view the key */
rc = key_task_permission(key_ref, ctx.cred, KEY_NEED_VIEW);
if (rc < 0)
return 0;
now = current_kernel_time();
rcu_read_lock();
/* come up with a suitable timeout value */
if (key->expiry == 0) {
memcpy(xbuf, "perm", 5);
} else if (now.tv_sec >= key->expiry) {
memcpy(xbuf, "expd", 5);
} else {
timo = key->expiry - now.tv_sec;
if (timo < 60)
sprintf(xbuf, "%lus", timo);
else if (timo < 60*60)
sprintf(xbuf, "%lum", timo / 60);
else if (timo < 60*60*24)
sprintf(xbuf, "%luh", timo / (60*60));
else if (timo < 60*60*24*7)
sprintf(xbuf, "%lud", timo
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