[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 ([email protected])
 */

#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 <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 <asm/system.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 <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(uid_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 (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 = ax25_uid->uid;
				break;
			}
		}
		read_unlock(&ax25_uid_lock);

		return res;

	case SIOCAX25ADDUID:
		if (!capable(CAP_NET_ADMIN))
			return -EPERM;
		user = ax25_findbyuid(sax->sax25_uid);
		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  = sax->sax25_uid;
		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)
{
	struct ax25_uid_assoc *pt;
	struct hlist_node *node;
	int i = 1;

	read_lock(&ax25_uid_lock);

	if (*pos == 0)
		return SEQ_START_TOKEN;

	ax25_uid_for_each(pt, node, &ax25_uid_list) {
		if (i == *pos)
			return pt;
		++i;
	}
	return NULL;
}

static void *ax25_uid_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
	++*pos;
	if (v == SEQ_START_TOKEN)
		return ax25_uid_list.first;
	else
		return hlist_entry(((ax25_uid_assoc *)v)->uid_node.next,
			   ax25_uid_assoc, uid_node);
}

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 = v;

		seq_printf(seq, "%6d %s\n", 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 ([email protected])
	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>
	21	#include <net/ax25.h>
	22	#include <linux/inet.h>
	23	#include <linux/netdevice.h>
	24	#include <linux/if_arp.h>
	25	#include <linux/skbuff.h>
	26	#include <net/sock.h>
	27	#include <asm/uaccess.h>
	28	#include <asm/system.h>
	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>
	39	#include <net/ip.h>
	40	#include <net/arp.h>
	41
	42	/*
	43	* Callsign/UID mapper. This is in kernel space for security on multi-amateur machines.
	44	*/
	45
f16f3026	46	static HLIST_HEAD(ax25_uid_list);
1da177e4 LT	47	static DEFINE_RWLOCK(ax25_uid_lock);
1da177e4 LT	48
f16f3026	49	int ax25_uid_policy;
1da177e4	50
70868eac RB	51	EXPORT_SYMBOL(ax25_uid_policy);
70868eac RB	52
01d7dd0e	53	ax25_uid_assoc *ax25_findbyuid(uid_t uid)
1da177e4	54	{
01d7dd0e RB	55	ax25_uid_assoc ax25_uid, res = NULL;
01d7dd0e RB	56	struct hlist_node *node;
1da177e4 LT	57
1da177e4 LT	58	read_lock(&ax25_uid_lock);
01d7dd0e	59	ax25_uid_for_each(ax25_uid, node, &ax25_uid_list) {
1da177e4	60	if (ax25_uid->uid == uid) {
01d7dd0e RB	61	ax25_uid_hold(ax25_uid);
01d7dd0e RB	62	res = ax25_uid;
1da177e4 LT	63	break;
	64	}
	65	}
	66	read_unlock(&ax25_uid_lock);
	67
01d7dd0e	68	return res;
1da177e4 LT	69	}
1da177e4 LT	70
70868eac RB	71	EXPORT_SYMBOL(ax25_findbyuid);
70868eac RB	72
1da177e4 LT	73	int ax25_uid_ioctl(int cmd, struct sockaddr_ax25 *sax)
1da177e4 LT	74	{
01d7dd0e RB	75	ax25_uid_assoc *ax25_uid;
	76	struct hlist_node *node;
	77	ax25_uid_assoc *user;
1da177e4 LT	78	unsigned long res;
	79
	80	switch (cmd) {
	81	case SIOCAX25GETUID:
	82	res = -ENOENT;
	83	read_lock(&ax25_uid_lock);
01d7dd0e	84	ax25_uid_for_each(ax25_uid, node, &ax25_uid_list) {
1da177e4 LT	85	if (ax25cmp(&sax->sax25_call, &ax25_uid->call) == 0) {
	86	res = ax25_uid->uid;
	87	break;
	88	}
	89	}
	90	read_unlock(&ax25_uid_lock);
	91
	92	return res;
	93
	94	case SIOCAX25ADDUID:
	95	if (!capable(CAP_NET_ADMIN))
	96	return -EPERM;
01d7dd0e RB	97	user = ax25_findbyuid(sax->sax25_uid);
	98	if (user) {
	99	ax25_uid_put(user);
1da177e4	100	return -EEXIST;
01d7dd0e	101	}
1da177e4 LT	102	if (sax->sax25_uid == 0)
	103	return -EINVAL;
	104	if ((ax25_uid = kmalloc(sizeof(*ax25_uid), GFP_KERNEL)) == NULL)
	105	return -ENOMEM;
	106
01d7dd0e	107	atomic_set(&ax25_uid->refcount, 1);
1da177e4 LT	108	ax25_uid->uid = sax->sax25_uid;
	109	ax25_uid->call = sax->sax25_call;
	110
	111	write_lock(&ax25_uid_lock);
01d7dd0e	112	hlist_add_head(&ax25_uid->uid_node, &ax25_uid_list);
1da177e4 LT	113	write_unlock(&ax25_uid_lock);
	114
	115	return 0;
	116
	117	case SIOCAX25DELUID:
	118	if (!capable(CAP_NET_ADMIN))
	119	return -EPERM;
	120
01d7dd0e	121	ax25_uid = NULL;
1da177e4	122	write_lock(&ax25_uid_lock);
01d7dd0e RB	123	ax25_uid_for_each(ax25_uid, node, &ax25_uid_list) {
01d7dd0e RB	124	if (ax25cmp(&sax->sax25_call, &ax25_uid->call) == 0)
1da177e4	125	break;
1da177e4 LT	126	}
	127	if (ax25_uid == NULL) {
	128	write_unlock(&ax25_uid_lock);
	129	return -ENOENT;
	130	}
01d7dd0e RB	131	hlist_del_init(&ax25_uid->uid_node);
01d7dd0e RB	132	ax25_uid_put(ax25_uid);
1da177e4 LT	133	write_unlock(&ax25_uid_lock);
1da177e4 LT	134
01d7dd0e	135	return 0;
1da177e4 LT	136
	137	default:
	138	return -EINVAL;
	139	}
	140
	141	return -EINVAL; /NOTREACHED /
	142	}
	143
	144	#ifdef CONFIG_PROC_FS
	145
	146	static void ax25_uid_seq_start(struct seq_file seq, loff_t *pos)
f16f3026	147	__acquires(ax25_uid_lock)
1da177e4 LT	148	{
1da177e4 LT	149	struct ax25_uid_assoc *pt;
01d7dd0e	150	struct hlist_node *node;
c7c1a0f6	151	int i = 1;
1da177e4 LT	152
1da177e4 LT	153	read_lock(&ax25_uid_lock);
c7c1a0f6 AC	154
	155	if (*pos == 0)
	156	return SEQ_START_TOKEN;
	157
01d7dd0e	158	ax25_uid_for_each(pt, node, &ax25_uid_list) {
1da177e4 LT	159	if (i == *pos)
	160	return pt;
	161	++i;
	162	}
	163	return NULL;
	164	}
	165
	166	static void ax25_uid_seq_next(struct seq_file seq, void v, loff_t pos)
	167	{
	168	++*pos;
c7c1a0f6 AC	169	if (v == SEQ_START_TOKEN)
	170	return ax25_uid_list.first;
	171	else
	172	return hlist_entry(((ax25_uid_assoc *)v)->uid_node.next,
528930b9	173	ax25_uid_assoc, uid_node);
1da177e4 LT	174	}
	175
	176	static void ax25_uid_seq_stop(struct seq_file seq, void v)
f16f3026	177	__releases(ax25_uid_lock)
1da177e4 LT	178	{
	179	read_unlock(&ax25_uid_lock);
	180	}
	181
	182	static int ax25_uid_seq_show(struct seq_file seq, void v)
	183	{
f75268cd RB	184	char buf[11];
f75268cd RB	185
1da177e4 LT	186	if (v == SEQ_START_TOKEN)
	187	seq_printf(seq, "Policy: %d\n", ax25_uid_policy);
	188	else {
	189	struct ax25_uid_assoc *pt = v;
1da177e4	190
f75268cd	191	seq_printf(seq, "%6d %s\n", pt->uid, ax2asc(buf, &pt->call));
1da177e4 LT	192	}
	193	return 0;
	194	}
	195
56b3d975	196	static const struct seq_operations ax25_uid_seqops = {
1da177e4 LT	197	.start = ax25_uid_seq_start,
	198	.next = ax25_uid_seq_next,
	199	.stop = ax25_uid_seq_stop,
	200	.show = ax25_uid_seq_show,
	201	};
	202
	203	static int ax25_uid_info_open(struct inode inode, struct file file)
	204	{
	205	return seq_open(file, &ax25_uid_seqops);
	206	}
	207
9a32144e	208	const struct file_operations ax25_uid_fops = {
1da177e4 LT	209	.owner = THIS_MODULE,
	210	.open = ax25_uid_info_open,
	211	.read = seq_read,
	212	.llseek = seq_lseek,
	213	.release = seq_release,
	214	};
	215
	216	#endif
	217
	218	/*
	219	* Free all memory associated with UID/Callsign structures.
	220	*/
	221	void __exit ax25_uid_free(void)
	222	{
01d7dd0e RB	223	ax25_uid_assoc *ax25_uid;
01d7dd0e RB	224	struct hlist_node *node;
1da177e4 LT	225
1da177e4 LT	226	write_lock(&ax25_uid_lock);
ae1b6a31	227	again:
01d7dd0e RB	228	ax25_uid_for_each(ax25_uid, node, &ax25_uid_list) {
	229	hlist_del_init(&ax25_uid->uid_node);
	230	ax25_uid_put(ax25_uid);
ae1b6a31	231	goto again;
1da177e4	232	}
1da177e4 LT	233	write_unlock(&ax25_uid_lock);
1da177e4 LT	234	}