diff options
Diffstat (limited to 'kernel/security/keys/proc.c')
| -rw-r--r-- | kernel/security/keys/proc.c | 352 |
1 files changed, 352 insertions, 0 deletions
diff --git a/kernel/security/keys/proc.c b/kernel/security/keys/proc.c new file mode 100644 index 000000000..f0611a636 --- /dev/null +++ b/kernel/security/keys/proc.c @@ -0,0 +1,352 @@ +/* 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[12]; + int rc; + + struct keyring_search_context ctx = { + .index_key.type = key->type, + .index_key.description = key->description, + .cred = current_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 (assuming + * non-possession) + * - the caller holds a spinlock, and thus the RCU read lock, making our + * access to __current_cred() safe + */ + 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 / (60*60*24)); + else + sprintf(xbuf, "%luw", timo / (60*60*24*7)); + } + +#define showflag(KEY, LETTER, FLAG) \ + (test_bit(FLAG, &(KEY)->flags) ? LETTER : '-') + + seq_printf(m, "%08x %c%c%c%c%c%c%c %5d %4s %08x %5d %5d %-9.9s ", + key->serial, + showflag(key, 'I', KEY_FLAG_INSTANTIATED), + showflag(key, 'R', KEY_FLAG_REVOKED), + showflag(key, 'D', KEY_FLAG_DEAD), + showflag(key, 'Q', KEY_FLAG_IN_QUOTA), + showflag(key, 'U', KEY_FLAG_USER_CONSTRUCT), + showflag(key, 'N', KEY_FLAG_NEGATIVE), + showflag(key, 'i', KEY_FLAG_INVALIDATED), + atomic_read(&key->usage), + xbuf, + key->perm, + from_kuid_munged(seq_user_ns(m), key->uid), + from_kgid_munged(seq_user_ns(m), key->gid), + key->type->name); + +#undef showflag + + if (key->type->describe) + key->type->describe(key, m); + seq_putc(m, '\n'); + + rcu_read_unlock(); + return 0; +} + +static struct rb_node *__key_user_next(struct user_namespace *user_ns, struct rb_node *n) +{ + while (n) { + struct key_user *user = rb_entry(n, struct key_user, node); + if (kuid_has_mapping(user_ns, user->uid)) + break; + n = rb_next(n); + } + return n; +} + +static struct rb_node *key_user_next(struct user_namespace *user_ns, struct rb_node *n) +{ + return __key_user_next(user_ns, rb_next(n)); +} + +static struct rb_node *key_user_first(struct user_namespace *user_ns, struct rb_root *r) +{ + struct rb_node *n = rb_first(r); + return __key_user_next(user_ns, n); +} + +/* + * Implement "/proc/key-users" to provides a list of the key users and their + * quotas. + */ +static int proc_key_users_open(struct inode *inode, struct file *file) +{ + return seq_open(file, &proc_key_users_ops); +} + +static void *proc_key_users_start(struct seq_file *p, loff_t *_pos) + __acquires(key_user_lock) +{ + struct rb_node *_p; + loff_t pos = *_pos; + + spin_lock(&key_user_lock); + + _p = key_user_first(seq_user_ns(p), &key_user_tree); + while (pos > 0 && _p) { + pos--; + _p = key_user_next(seq_user_ns(p), _p); + } + + return _p; +} + +static void *proc_key_users_next(struct seq_file *p, void *v, loff_t *_pos) +{ + (*_pos)++; + return key_user_next(seq_user_ns(p), (struct rb_node *)v); +} + +static void proc_key_users_stop(struct seq_file *p, void *v) + __releases(key_user_lock) +{ + spin_unlock(&key_user_lock); +} + +static int proc_key_users_show(struct seq_file *m, void *v) +{ + struct rb_node *_p = v; + struct key_user *user = rb_entry(_p, struct key_user, node); + unsigned maxkeys = uid_eq(user->uid, GLOBAL_ROOT_UID) ? + key_quota_root_maxkeys : key_quota_maxkeys; + unsigned maxbytes = uid_eq(user->uid, GLOBAL_ROOT_UID) ? + key_quota_root_maxbytes : key_quota_maxbytes; + + seq_printf(m, "%5u: %5d %d/%d %d/%d %d/%d\n", + from_kuid_munged(seq_user_ns(m), user->uid), + atomic_read(&user->usage), + atomic_read(&user->nkeys), + atomic_read(&user->nikeys), + user->qnkeys, + maxkeys, + user->qnbytes, + maxbytes); + + return 0; +} |