[deliverable/linux.git] / net / ax25 / ax25_uid.c

/*
 * 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.
 *
 * Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
 */

#include <linux/capability.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/kernel.h>
#include <linux/timer.h>
#include <linux/string.h>
#include <linux/sockios.h>
#include <linux/net.h>
#include <linux/spinlock.h>
#include <linux/slab.h>
#include <net/ax25.h>
#include <linux/inet.h>
#include <linux/netdevice.h>
#include <linux/if_arp.h>
#include <linux/skbuff.h>
#include <net/sock.h>
#include <asm/uaccess.h>
#include <linux/fcntl.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/list.h>
#include <linux/notifier.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/stat.h>
#include <linux/netfilter.h>
#include <linux/sysctl.h>
#include <linux/export.h>
#include <net/ip.h>
#include <net/arp.h>

/*
 *	Callsign/UID mapper. This is in kernel space for security on multi-amateur machines.
 */

static HLIST_HEAD(ax25_uid_list);
static DEFINE_RWLOCK(ax25_uid_lock);

int ax25_uid_policy;

EXPORT_SYMBOL(ax25_uid_policy);

ax25_uid_assoc *ax25_findbyuid(kuid_t uid)
{
	ax25_uid_assoc *ax25_uid, *res = NULL;
	struct hlist_node *node;

	read_lock(&ax25_uid_lock);
	ax25_uid_for_each(ax25_uid, node, &ax25_uid_list) {
		if (uid_eq(ax25_uid->uid, uid)) {
			ax25_uid_hold(ax25_uid);
			res = ax25_uid;
			break;
		}
	}
	read_unlock(&ax25_uid_lock);

	return res;
}

EXPORT_SYMBOL(ax25_findbyuid);

int ax25_uid_ioctl(int cmd, struct sockaddr_ax25 *sax)
{
	ax25_uid_assoc *ax25_uid;
	struct hlist_node *node;
	ax25_uid_assoc *user;
	unsigned long res;

	switch (cmd) {
	case SIOCAX25GETUID:
		res = -ENOENT;
		read_lock(&ax25_uid_lock);
		ax25_uid_for_each(ax25_uid, node, &ax25_uid_list) {
			if (ax25cmp(&sax->sax25_call, &ax25_uid->call) == 0) {
				res = from_kuid_munged(current_user_ns(), ax25_uid->uid);
				break;
			}
		}
		read_unlock(&ax25_uid_lock);

		return res;

	case SIOCAX25ADDUID:
	{
		kuid_t sax25_kuid;
		if (!capable(CAP_NET_ADMIN))
			return -EPERM;
		sax25_kuid = make_kuid(current_user_ns(), sax->sax25_uid);
		if (!uid_valid(sax25_kuid))
			return -EINVAL;
		user = ax25_findbyuid(sax25_kuid);
		if (user) {
			ax25_uid_put(user);
			return -EEXIST;
		}
		if (sax->sax25_uid == 0)
			return -EINVAL;
		if ((ax25_uid = kmalloc(sizeof(*ax25_uid), GFP_KERNEL)) == NULL)
			return -ENOMEM;

		atomic_set(&ax25_uid->refcount, 1);
		ax25_uid->uid  = sax25_kuid;
		ax25_uid->call = sax->sax25_call;

		write_lock(&ax25_uid_lock);
		hlist_add_head(&ax25_uid->uid_node, &ax25_uid_list);
		write_unlock(&ax25_uid_lock);

		return 0;
	}
	case SIOCAX25DELUID:
		if (!capable(CAP_NET_ADMIN))
			return -EPERM;

		ax25_uid = NULL;
		write_lock(&ax25_uid_lock);
		ax25_uid_for_each(ax25_uid, node, &ax25_uid_list) {
			if (ax25cmp(&sax->sax25_call, &ax25_uid->call) == 0)
				break;
		}
		if (ax25_uid == NULL) {
			write_unlock(&ax25_uid_lock);
			return -ENOENT;
		}
		hlist_del_init(&ax25_uid->uid_node);
		ax25_uid_put(ax25_uid);
		write_unlock(&ax25_uid_lock);

		return 0;

	default:
		return -EINVAL;
	}

	return -EINVAL;	/*NOTREACHED */
}

#ifdef CONFIG_PROC_FS

static void *ax25_uid_seq_start(struct seq_file *seq, loff_t *pos)
	__acquires(ax25_uid_lock)
{
	read_lock(&ax25_uid_lock);
	return seq_hlist_start_head(&ax25_uid_list, *pos);
}

static void *ax25_uid_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
	return seq_hlist_next(v, &ax25_uid_list, pos);
}

static void ax25_uid_seq_stop(struct seq_file *seq, void *v)
	__releases(ax25_uid_lock)
{
	read_unlock(&ax25_uid_lock);
}

static int ax25_uid_seq_show(struct seq_file *seq, void *v)
{
	char buf[11];

	if (v == SEQ_START_TOKEN)
		seq_printf(seq, "Policy: %d\n", ax25_uid_policy);
	else {
		struct ax25_uid_assoc *pt;

		pt = hlist_entry(v, struct ax25_uid_assoc, uid_node);
		seq_printf(seq, "%6d %s\n",
			from_kuid_munged(seq_user_ns(seq), pt->uid),
			ax2asc(buf, &pt->call));
	}
	return 0;
}

static const struct seq_operations ax25_uid_seqops = {
	.start = ax25_uid_seq_start,
	.next = ax25_uid_seq_next,
	.stop = ax25_uid_seq_stop,
	.show = ax25_uid_seq_show,
};

static int ax25_uid_info_open(struct inode *inode, struct file *file)
{
	return seq_open(file, &ax25_uid_seqops);
}

const struct file_operations ax25_uid_fops = {
	.owner = THIS_MODULE,
	.open = ax25_uid_info_open,
	.read = seq_read,
	.llseek = seq_lseek,
	.release = seq_release,
};

#endif

/*
 *	Free all memory associated with UID/Callsign structures.
 */
void __exit ax25_uid_free(void)
{
	ax25_uid_assoc *ax25_uid;
	struct hlist_node *node;

	write_lock(&ax25_uid_lock);
again:
	ax25_uid_for_each(ax25_uid, node, &ax25_uid_list) {
		hlist_del_init(&ax25_uid->uid_node);
		ax25_uid_put(ax25_uid);
		goto again;
	}
	write_unlock(&ax25_uid_lock);
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* This program is free software; you can redistribute it and/or modify
	3	* it under the terms of the GNU General Public License as published by
	4	* the Free Software Foundation; either version 2 of the License, or
	5	* (at your option) any later version.
	6	*
	7	* Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
	8	*/
4fc268d2 RD	9
4fc268d2 RD	10	#include <linux/capability.h>
1da177e4 LT	11	#include <linux/errno.h>
	12	#include <linux/types.h>
	13	#include <linux/socket.h>
	14	#include <linux/in.h>
	15	#include <linux/kernel.h>
1da177e4 LT	16	#include <linux/timer.h>
	17	#include <linux/string.h>
	18	#include <linux/sockios.h>
	19	#include <linux/net.h>
	20	#include <linux/spinlock.h>
5a0e3ad6	21	#include <linux/slab.h>
1da177e4 LT	22	#include <net/ax25.h>
	23	#include <linux/inet.h>
	24	#include <linux/netdevice.h>
	25	#include <linux/if_arp.h>
	26	#include <linux/skbuff.h>
	27	#include <net/sock.h>
	28	#include <asm/uaccess.h>
1da177e4 LT	29	#include <linux/fcntl.h>
	30	#include <linux/mm.h>
	31	#include <linux/interrupt.h>
01d7dd0e	32	#include <linux/list.h>
1da177e4 LT	33	#include <linux/notifier.h>
	34	#include <linux/proc_fs.h>
	35	#include <linux/seq_file.h>
	36	#include <linux/stat.h>
	37	#include <linux/netfilter.h>
	38	#include <linux/sysctl.h>
bc3b2d7f	39	#include <linux/export.h>
1da177e4 LT	40	#include <net/ip.h>
	41	#include <net/arp.h>
	42
	43	/*
	44	* Callsign/UID mapper. This is in kernel space for security on multi-amateur machines.
	45	*/
	46
f16f3026	47	static HLIST_HEAD(ax25_uid_list);
1da177e4 LT	48	static DEFINE_RWLOCK(ax25_uid_lock);
1da177e4 LT	49
f16f3026	50	int ax25_uid_policy;
1da177e4	51
70868eac RB	52	EXPORT_SYMBOL(ax25_uid_policy);
70868eac RB	53
d13fda85	54	ax25_uid_assoc *ax25_findbyuid(kuid_t uid)
1da177e4	55	{
01d7dd0e RB	56	ax25_uid_assoc ax25_uid, res = NULL;
01d7dd0e RB	57	struct hlist_node *node;
1da177e4 LT	58
1da177e4 LT	59	read_lock(&ax25_uid_lock);
01d7dd0e	60	ax25_uid_for_each(ax25_uid, node, &ax25_uid_list) {
d13fda85	61	if (uid_eq(ax25_uid->uid, uid)) {
01d7dd0e RB	62	ax25_uid_hold(ax25_uid);
01d7dd0e RB	63	res = ax25_uid;
1da177e4 LT	64	break;
	65	}
	66	}
	67	read_unlock(&ax25_uid_lock);
	68
01d7dd0e	69	return res;
1da177e4 LT	70	}
1da177e4 LT	71
70868eac RB	72	EXPORT_SYMBOL(ax25_findbyuid);
70868eac RB	73
1da177e4 LT	74	int ax25_uid_ioctl(int cmd, struct sockaddr_ax25 *sax)
1da177e4 LT	75	{
01d7dd0e RB	76	ax25_uid_assoc *ax25_uid;
	77	struct hlist_node *node;
	78	ax25_uid_assoc *user;
1da177e4 LT	79	unsigned long res;
	80
	81	switch (cmd) {
	82	case SIOCAX25GETUID:
	83	res = -ENOENT;
	84	read_lock(&ax25_uid_lock);
01d7dd0e	85	ax25_uid_for_each(ax25_uid, node, &ax25_uid_list) {
1da177e4	86	if (ax25cmp(&sax->sax25_call, &ax25_uid->call) == 0) {
d13fda85	87	res = from_kuid_munged(current_user_ns(), ax25_uid->uid);
1da177e4 LT	88	break;
	89	}
	90	}
	91	read_unlock(&ax25_uid_lock);
	92
	93	return res;
	94
	95	case SIOCAX25ADDUID:
d13fda85 EB	96	{
d13fda85 EB	97	kuid_t sax25_kuid;
1da177e4 LT	98	if (!capable(CAP_NET_ADMIN))
1da177e4 LT	99	return -EPERM;
d13fda85 EB	100	sax25_kuid = make_kuid(current_user_ns(), sax->sax25_uid);
	101	if (!uid_valid(sax25_kuid))
	102	return -EINVAL;
	103	user = ax25_findbyuid(sax25_kuid);
01d7dd0e RB	104	if (user) {
01d7dd0e RB	105	ax25_uid_put(user);
1da177e4	106	return -EEXIST;
01d7dd0e	107	}
1da177e4 LT	108	if (sax->sax25_uid == 0)
	109	return -EINVAL;
	110	if ((ax25_uid = kmalloc(sizeof(*ax25_uid), GFP_KERNEL)) == NULL)
	111	return -ENOMEM;
	112
01d7dd0e	113	atomic_set(&ax25_uid->refcount, 1);
d13fda85	114	ax25_uid->uid = sax25_kuid;
1da177e4 LT	115	ax25_uid->call = sax->sax25_call;
	116
	117	write_lock(&ax25_uid_lock);
01d7dd0e	118	hlist_add_head(&ax25_uid->uid_node, &ax25_uid_list);
1da177e4 LT	119	write_unlock(&ax25_uid_lock);
	120
	121	return 0;
d13fda85	122	}
1da177e4 LT	123	case SIOCAX25DELUID:
	124	if (!capable(CAP_NET_ADMIN))
	125	return -EPERM;
	126
01d7dd0e	127	ax25_uid = NULL;
1da177e4	128	write_lock(&ax25_uid_lock);
01d7dd0e RB	129	ax25_uid_for_each(ax25_uid, node, &ax25_uid_list) {
01d7dd0e RB	130	if (ax25cmp(&sax->sax25_call, &ax25_uid->call) == 0)
1da177e4	131	break;
1da177e4 LT	132	}
	133	if (ax25_uid == NULL) {
	134	write_unlock(&ax25_uid_lock);
	135	return -ENOENT;
	136	}
01d7dd0e RB	137	hlist_del_init(&ax25_uid->uid_node);
01d7dd0e RB	138	ax25_uid_put(ax25_uid);
1da177e4 LT	139	write_unlock(&ax25_uid_lock);
1da177e4 LT	140
01d7dd0e	141	return 0;
1da177e4 LT	142
	143	default:
	144	return -EINVAL;
	145	}
	146
	147	return -EINVAL; /NOTREACHED /
	148	}
	149
	150	#ifdef CONFIG_PROC_FS
	151
	152	static void ax25_uid_seq_start(struct seq_file seq, loff_t *pos)
f16f3026	153	__acquires(ax25_uid_lock)
1da177e4	154	{
1da177e4	155	read_lock(&ax25_uid_lock);
b512f3d8	156	return seq_hlist_start_head(&ax25_uid_list, *pos);
1da177e4 LT	157	}
	158
	159	static void ax25_uid_seq_next(struct seq_file seq, void v, loff_t pos)
	160	{
b512f3d8	161	return seq_hlist_next(v, &ax25_uid_list, pos);
1da177e4 LT	162	}
	163
	164	static void ax25_uid_seq_stop(struct seq_file seq, void v)
f16f3026	165	__releases(ax25_uid_lock)
1da177e4 LT	166	{
	167	read_unlock(&ax25_uid_lock);
	168	}
	169
	170	static int ax25_uid_seq_show(struct seq_file seq, void v)
	171	{
f75268cd RB	172	char buf[11];
f75268cd RB	173
1da177e4 LT	174	if (v == SEQ_START_TOKEN)
	175	seq_printf(seq, "Policy: %d\n", ax25_uid_policy);
	176	else {
b512f3d8	177	struct ax25_uid_assoc *pt;
1da177e4	178
b512f3d8	179	pt = hlist_entry(v, struct ax25_uid_assoc, uid_node);
d13fda85 EB	180	seq_printf(seq, "%6d %s\n",
	181	from_kuid_munged(seq_user_ns(seq), pt->uid),
	182	ax2asc(buf, &pt->call));
1da177e4 LT	183	}
	184	return 0;
	185	}
	186
56b3d975	187	static const struct seq_operations ax25_uid_seqops = {
1da177e4 LT	188	.start = ax25_uid_seq_start,
	189	.next = ax25_uid_seq_next,
	190	.stop = ax25_uid_seq_stop,
	191	.show = ax25_uid_seq_show,
	192	};
	193
	194	static int ax25_uid_info_open(struct inode inode, struct file file)
	195	{
	196	return seq_open(file, &ax25_uid_seqops);
	197	}
	198
9a32144e	199	const struct file_operations ax25_uid_fops = {
1da177e4 LT	200	.owner = THIS_MODULE,
	201	.open = ax25_uid_info_open,
	202	.read = seq_read,
	203	.llseek = seq_lseek,
	204	.release = seq_release,
	205	};
	206
	207	#endif
	208
	209	/*
	210	* Free all memory associated with UID/Callsign structures.
	211	*/
	212	void __exit ax25_uid_free(void)
	213	{
01d7dd0e RB	214	ax25_uid_assoc *ax25_uid;
01d7dd0e RB	215	struct hlist_node *node;
1da177e4 LT	216
1da177e4 LT	217	write_lock(&ax25_uid_lock);
ae1b6a31	218	again:
01d7dd0e RB	219	ax25_uid_for_each(ax25_uid, node, &ax25_uid_list) {
	220	hlist_del_init(&ax25_uid->uid_node);
	221	ax25_uid_put(ax25_uid);
ae1b6a31	222	goto again;
1da177e4	223	}
1da177e4 LT	224	write_unlock(&ax25_uid_lock);
1da177e4 LT	225	}