[net-next-2.6.git] / net / decnet / netfilter / dn_rtmsg.c

/*
 * DECnet       An implementation of the DECnet protocol suite for the LINUX
 *              operating system.  DECnet is implemented using the  BSD Socket
 *              interface as the means of communication with the user level.
 *
 *              DECnet Routing Message Grabulator
 *
 *              (C) 2000 ChyGwyn Limited  -  http://www.chygwyn.com/
 *              This code may be copied under the GPL v.2 or at your option
 *              any later version.
 *
 * Author:      Steven Whitehouse <steve@chygwyn.com>
 *
 */
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/init.h>
#include <linux/netdevice.h>
#include <linux/netfilter.h>
#include <linux/spinlock.h>
#include <linux/netlink.h>
#include <linux/netfilter_decnet.h>

#include <net/sock.h>
#include <net/flow.h>
#include <net/dn.h>
#include <net/dn_route.h>

static struct sock *dnrmg = NULL;


static struct sk_buff *dnrmg_build_message(struct sk_buff *rt_skb, int *errp)
{
	struct sk_buff *skb = NULL;
	size_t size;
	unsigned char *old_tail;
	struct nlmsghdr *nlh;
	unsigned char *ptr;
	struct nf_dn_rtmsg *rtm;

	size = NLMSG_SPACE(rt_skb->len);
	size += NLMSG_ALIGN(sizeof(struct nf_dn_rtmsg));
	skb = alloc_skb(size, GFP_ATOMIC);
	if (!skb)
		goto nlmsg_failure;
	old_tail = skb->tail;
	nlh = NLMSG_PUT(skb, 0, 0, 0, size - sizeof(*nlh));
	rtm = (struct nf_dn_rtmsg *)NLMSG_DATA(nlh);
	rtm->nfdn_ifindex = rt_skb->dev->ifindex;
	ptr = NFDN_RTMSG(rtm);
	memcpy(ptr, rt_skb->data, rt_skb->len);
	nlh->nlmsg_len = skb->tail - old_tail;
	return skb;

nlmsg_failure:
	if (skb)
		kfree_skb(skb);
	*errp = -ENOMEM;
	if (net_ratelimit())
		printk(KERN_ERR "dn_rtmsg: error creating netlink message\n");
	return NULL;
}

static void dnrmg_send_peer(struct sk_buff *skb)
{
	struct sk_buff *skb2;
	int status = 0;
	int group = 0;
	unsigned char flags = *skb->data;

	switch(flags & DN_RT_CNTL_MSK) {
		case DN_RT_PKT_L1RT:
			group = DNRNG_NLGRP_L1;
			break;
		case DN_RT_PKT_L2RT:
			group = DNRNG_NLGRP_L2;
			break;
		default:
			return;
	}

	skb2 = dnrmg_build_message(skb, &status);
	if (skb2 == NULL)
		return;
	NETLINK_CB(skb2).dst_group = group;
	netlink_broadcast(dnrmg, skb2, 0, group, GFP_ATOMIC);
}


static unsigned int dnrmg_hook(unsigned int hook,
			struct sk_buff **pskb,
			const struct net_device *in,
			const struct net_device *out,
			int (*okfn)(struct sk_buff *))
{
	dnrmg_send_peer(*pskb);
	return NF_ACCEPT;
}


#define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)

static inline void dnrmg_receive_user_skb(struct sk_buff *skb)
{
	struct nlmsghdr *nlh = (struct nlmsghdr *)skb->data;

	if (nlh->nlmsg_len < sizeof(*nlh) || skb->len < nlh->nlmsg_len)
		return;

	if (!cap_raised(NETLINK_CB(skb).eff_cap, CAP_NET_ADMIN))
		RCV_SKB_FAIL(-EPERM);

	/* Eventually we might send routing messages too */

	RCV_SKB_FAIL(-EINVAL);
}

static void dnrmg_receive_user_sk(struct sock *sk, int len)
{
	struct sk_buff *skb;
	unsigned int qlen = skb_queue_len(&sk->sk_receive_queue);

	for (; qlen && (skb = skb_dequeue(&sk->sk_receive_queue)); qlen--) {
		dnrmg_receive_user_skb(skb);
		kfree_skb(skb);
	}
}

static struct nf_hook_ops dnrmg_ops = {
	.hook		= dnrmg_hook,
	.pf		= PF_DECnet,
	.hooknum	= NF_DN_ROUTE,
	.priority	= NF_DN_PRI_DNRTMSG,
};

static int __init init(void)
{
	int rv = 0;

	dnrmg = netlink_kernel_create(NETLINK_DNRTMSG, DNRNG_NLGRP_MAX,
	                              dnrmg_receive_user_sk, THIS_MODULE);
	if (dnrmg == NULL) {
		printk(KERN_ERR "dn_rtmsg: Cannot create netlink socket");
		return -ENOMEM;
	}

	rv = nf_register_hook(&dnrmg_ops);
	if (rv) {
		sock_release(dnrmg->sk_socket);
	}

	return rv;
}

static void __exit fini(void)
{
	nf_unregister_hook(&dnrmg_ops);
	sock_release(dnrmg->sk_socket);
}


MODULE_DESCRIPTION("DECnet Routing Message Grabulator");
MODULE_AUTHOR("Steven Whitehouse <steve@chygwyn.com>");
MODULE_LICENSE("GPL");
MODULE_ALIAS_NET_PF_PROTO(PF_NETLINK, NETLINK_DNRTMSG);

module_init(init);
module_exit(fini);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* DECnet An implementation of the DECnet protocol suite for the LINUX
	3	* operating system. DECnet is implemented using the BSD Socket
	4	* interface as the means of communication with the user level.
	5	*
	6	* DECnet Routing Message Grabulator
	7	*
	8	* (C) 2000 ChyGwyn Limited - http://www.chygwyn.com/
	9	* This code may be copied under the GPL v.2 or at your option
	10	* any later version.
	11	*
	12	* Author: Steven Whitehouse <steve@chygwyn.com>
	13	*
	14	*/
	15	#include <linux/module.h>
	16	#include <linux/skbuff.h>
	17	#include <linux/init.h>
	18	#include <linux/netdevice.h>
	19	#include <linux/netfilter.h>
	20	#include <linux/spinlock.h>
	21	#include <linux/netlink.h>
63a1222b	22	#include <linux/netfilter_decnet.h>
1da177e4 LT	23
	24	#include <net/sock.h>
	25	#include <net/flow.h>
	26	#include <net/dn.h>
	27	#include <net/dn_route.h>
	28
1da177e4 LT	29	static struct sock *dnrmg = NULL;
	30
	31
	32	static struct sk_buff dnrmg_build_message(struct sk_buff rt_skb, int *errp)
	33	{
	34	struct sk_buff *skb = NULL;
	35	size_t size;
	36	unsigned char *old_tail;
	37	struct nlmsghdr *nlh;
	38	unsigned char *ptr;
	39	struct nf_dn_rtmsg *rtm;
	40
	41	size = NLMSG_SPACE(rt_skb->len);
	42	size += NLMSG_ALIGN(sizeof(struct nf_dn_rtmsg));
	43	skb = alloc_skb(size, GFP_ATOMIC);
	44	if (!skb)
	45	goto nlmsg_failure;
	46	old_tail = skb->tail;
	47	nlh = NLMSG_PUT(skb, 0, 0, 0, size - sizeof(*nlh));
	48	rtm = (struct nf_dn_rtmsg *)NLMSG_DATA(nlh);
	49	rtm->nfdn_ifindex = rt_skb->dev->ifindex;
	50	ptr = NFDN_RTMSG(rtm);
	51	memcpy(ptr, rt_skb->data, rt_skb->len);
	52	nlh->nlmsg_len = skb->tail - old_tail;
	53	return skb;
	54
	55	nlmsg_failure:
	56	if (skb)
	57	kfree_skb(skb);
	58	*errp = -ENOMEM;
	59	if (net_ratelimit())
	60	printk(KERN_ERR "dn_rtmsg: error creating netlink message\n");
	61	return NULL;
	62	}
	63
	64	static void dnrmg_send_peer(struct sk_buff *skb)
	65	{
	66	struct sk_buff *skb2;
	67	int status = 0;
	68	int group = 0;
	69	unsigned char flags = *skb->data;
	70
	71	switch(flags & DN_RT_CNTL_MSK) {
	72	case DN_RT_PKT_L1RT:
63a1222b	73	group = DNRNG_NLGRP_L1;
1da177e4 LT	74	break;
1da177e4 LT	75	case DN_RT_PKT_L2RT:
63a1222b	76	group = DNRNG_NLGRP_L2;
1da177e4 LT	77	break;
	78	default:
	79	return;
	80	}
	81
	82	skb2 = dnrmg_build_message(skb, &status);
	83	if (skb2 == NULL)
	84	return;
ac6d439d	85	NETLINK_CB(skb2).dst_group = group;
1da177e4 LT	86	netlink_broadcast(dnrmg, skb2, 0, group, GFP_ATOMIC);
	87	}
	88
	89
	90	static unsigned int dnrmg_hook(unsigned int hook,
	91	struct sk_buff **pskb,
	92	const struct net_device *in,
	93	const struct net_device *out,
	94	int (okfn)(struct sk_buff ))
	95	{
	96	dnrmg_send_peer(*pskb);
	97	return NF_ACCEPT;
	98	}
	99
	100
	101	#define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
	102
	103	static inline void dnrmg_receive_user_skb(struct sk_buff *skb)
	104	{
	105	struct nlmsghdr nlh = (struct nlmsghdr )skb->data;
	106
	107	if (nlh->nlmsg_len < sizeof(*nlh) \|\| skb->len < nlh->nlmsg_len)
	108	return;
	109
	110	if (!cap_raised(NETLINK_CB(skb).eff_cap, CAP_NET_ADMIN))
	111	RCV_SKB_FAIL(-EPERM);
	112
	113	/* Eventually we might send routing messages too */
	114
	115	RCV_SKB_FAIL(-EINVAL);
	116	}
	117
	118	static void dnrmg_receive_user_sk(struct sock *sk, int len)
	119	{
	120	struct sk_buff *skb;
2a0a6ebe	121	unsigned int qlen = skb_queue_len(&sk->sk_receive_queue);
1da177e4	122
09e14305	123	for (; qlen && (skb = skb_dequeue(&sk->sk_receive_queue)); qlen--) {
1da177e4 LT	124	dnrmg_receive_user_skb(skb);
	125	kfree_skb(skb);
	126	}
	127	}
	128
	129	static struct nf_hook_ops dnrmg_ops = {
	130	.hook = dnrmg_hook,
	131	.pf = PF_DECnet,
	132	.hooknum = NF_DN_ROUTE,
	133	.priority = NF_DN_PRI_DNRTMSG,
	134	};
	135
	136	static int __init init(void)
	137	{
	138	int rv = 0;
	139
06628607 PM	140	dnrmg = netlink_kernel_create(NETLINK_DNRTMSG, DNRNG_NLGRP_MAX,
06628607 PM	141	dnrmg_receive_user_sk, THIS_MODULE);
1da177e4 LT	142	if (dnrmg == NULL) {
	143	printk(KERN_ERR "dn_rtmsg: Cannot create netlink socket");
	144	return -ENOMEM;
	145	}
	146
	147	rv = nf_register_hook(&dnrmg_ops);
	148	if (rv) {
	149	sock_release(dnrmg->sk_socket);
	150	}
	151
	152	return rv;
	153	}
	154
	155	static void __exit fini(void)
	156	{
	157	nf_unregister_hook(&dnrmg_ops);
	158	sock_release(dnrmg->sk_socket);
	159	}
	160
	161
	162	MODULE_DESCRIPTION("DECnet Routing Message Grabulator");
	163	MODULE_AUTHOR("Steven Whitehouse <steve@chygwyn.com>");
	164	MODULE_LICENSE("GPL");
4fdb3bb7	165	MODULE_ALIAS_NET_PF_PROTO(PF_NETLINK, NETLINK_DNRTMSG);
1da177e4 LT	166
	167	module_init(init);
	168	module_exit(fini);
	169