[net-next-2.6.git] / net / ipv4 / netfilter / ipt_ULOG.c

/*
 * netfilter module for userspace packet logging daemons
 *
 * (C) 2000-2004 by Harald Welte <laforge@netfilter.org>
 * (C) 1999-2001 Paul `Rusty' Russell
 * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This module accepts two parameters:
 *
 * nlbufsiz:
 *   The parameter specifies how big the buffer for each netlink multicast
 * group is. e.g. If you say nlbufsiz=8192, up to eight kb of packets will
 * get accumulated in the kernel until they are sent to userspace. It is
 * NOT possible to allocate more than 128kB, and it is strongly discouraged,
 * because atomically allocating 128kB inside the network rx softirq is not
 * reliable. Please also keep in mind that this buffer size is allocated for
 * each nlgroup you are using, so the total kernel memory usage increases
 * by that factor.
 *
 * Actually you should use nlbufsiz a bit smaller than PAGE_SIZE, since
 * nlbufsiz is used with alloc_skb, which adds another
 * sizeof(struct skb_shared_info).  Use NLMSG_GOODSIZE instead.
 *
 * flushtimeout:
 *   Specify, after how many hundredths of a second the queue should be
 *   flushed even if it is not full yet.
 */

#include <linux/module.h>
#include <linux/spinlock.h>
#include <linux/socket.h>
#include <linux/skbuff.h>
#include <linux/kernel.h>
#include <linux/timer.h>
#include <linux/netlink.h>
#include <linux/netdevice.h>
#include <linux/mm.h>
#include <linux/moduleparam.h>
#include <linux/netfilter.h>
#include <linux/netfilter/x_tables.h>
#include <linux/netfilter_ipv4/ipt_ULOG.h>
#include <net/sock.h>
#include <linux/bitops.h>
#include <asm/unaligned.h>

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Harald Welte <laforge@gnumonks.org>");
MODULE_DESCRIPTION("iptables userspace logging module");
MODULE_ALIAS_NET_PF_PROTO(PF_NETLINK, NETLINK_NFLOG);

#define ULOG_NL_EVENT		111		/* Harald's favorite number */
#define ULOG_MAXNLGROUPS	32		/* numer of nlgroups */

#if 0
#define DEBUGP(format, args...) printk("%s:%s:" format, \
				       __FILE__, __FUNCTION__ , ## args)
#else
#define DEBUGP(format, args...)
#endif

#define PRINTR(format, args...) do { if (net_ratelimit()) printk(format , ## args); } while (0)

static unsigned int nlbufsiz = NLMSG_GOODSIZE;
module_param(nlbufsiz, uint, 0400);
MODULE_PARM_DESC(nlbufsiz, "netlink buffer size");

static unsigned int flushtimeout = 10;
module_param(flushtimeout, uint, 0600);
MODULE_PARM_DESC(flushtimeout, "buffer flush timeout (hundredths of a second)");

static int nflog = 1;
module_param(nflog, bool, 0400);
MODULE_PARM_DESC(nflog, "register as internal netfilter logging module");

/* global data structures */

typedef struct {
	unsigned int qlen;		/* number of nlmsgs' in the skb */
	struct nlmsghdr *lastnlh;	/* netlink header of last msg in skb */
	struct sk_buff *skb;		/* the pre-allocated skb */
	struct timer_list timer;	/* the timer function */
} ulog_buff_t;

static ulog_buff_t ulog_buffers[ULOG_MAXNLGROUPS];	/* array of buffers */

static struct sock *nflognl;		/* our socket */
static DEFINE_SPINLOCK(ulog_lock);	/* spinlock */

/* send one ulog_buff_t to userspace */
static void ulog_send(unsigned int nlgroupnum)
{
	ulog_buff_t *ub = &ulog_buffers[nlgroupnum];

	if (timer_pending(&ub->timer)) {
		DEBUGP("ipt_ULOG: ulog_send: timer was pending, deleting\n");
		del_timer(&ub->timer);
	}

	if (!ub->skb) {
		DEBUGP("ipt_ULOG: ulog_send: nothing to send\n");
		return;
	}

	/* last nlmsg needs NLMSG_DONE */
	if (ub->qlen > 1)
		ub->lastnlh->nlmsg_type = NLMSG_DONE;

	NETLINK_CB(ub->skb).dst_group = nlgroupnum + 1;
	DEBUGP("ipt_ULOG: throwing %d packets to netlink group %u\n",
		ub->qlen, nlgroupnum + 1);
	netlink_broadcast(nflognl, ub->skb, 0, nlgroupnum + 1, GFP_ATOMIC);

	ub->qlen = 0;
	ub->skb = NULL;
	ub->lastnlh = NULL;
}


/* timer function to flush queue in flushtimeout time */
static void ulog_timer(unsigned long data)
{
	DEBUGP("ipt_ULOG: timer function called, calling ulog_send\n");

	/* lock to protect against somebody modifying our structure
	 * from ipt_ulog_target at the same time */
	spin_lock_bh(&ulog_lock);
	ulog_send(data);
	spin_unlock_bh(&ulog_lock);
}

static struct sk_buff *ulog_alloc_skb(unsigned int size)
{
	struct sk_buff *skb;
	unsigned int n;

	/* alloc skb which should be big enough for a whole
	 * multipart message. WARNING: has to be <= 131000
	 * due to slab allocator restrictions */

	n = max(size, nlbufsiz);
	skb = alloc_skb(n, GFP_ATOMIC);
	if (!skb) {
		PRINTR("ipt_ULOG: can't alloc whole buffer %ub!\n", n);

		if (n > size) {
			/* try to allocate only as much as we need for
			 * current packet */

			skb = alloc_skb(size, GFP_ATOMIC);
			if (!skb)
				PRINTR("ipt_ULOG: can't even allocate %ub\n",
				       size);
		}
	}

	return skb;
}

static void ipt_ulog_packet(unsigned int hooknum,
			    const struct sk_buff *skb,
			    const struct net_device *in,
			    const struct net_device *out,
			    const struct ipt_ulog_info *loginfo,
			    const char *prefix)
{
	ulog_buff_t *ub;
	ulog_packet_msg_t *pm;
	size_t size, copy_len;
	struct nlmsghdr *nlh;
	struct timeval tv;

	/* ffs == find first bit set, necessary because userspace
	 * is already shifting groupnumber, but we need unshifted.
	 * ffs() returns [1..32], we need [0..31] */
	unsigned int groupnum = ffs(loginfo->nl_group) - 1;

	/* calculate the size of the skb needed */
	if (loginfo->copy_range == 0 || loginfo->copy_range > skb->len)
		copy_len = skb->len;
	else
		copy_len = loginfo->copy_range;

	size = NLMSG_SPACE(sizeof(*pm) + copy_len);

	ub = &ulog_buffers[groupnum];

	spin_lock_bh(&ulog_lock);

	if (!ub->skb) {
		if (!(ub->skb = ulog_alloc_skb(size)))
			goto alloc_failure;
	} else if (ub->qlen >= loginfo->qthreshold ||
		   size > skb_tailroom(ub->skb)) {
		/* either the queue len is too high or we don't have
		 * enough room in nlskb left. send it to userspace. */

		ulog_send(groupnum);

		if (!(ub->skb = ulog_alloc_skb(size)))
			goto alloc_failure;
	}

	DEBUGP("ipt_ULOG: qlen %d, qthreshold %d\n", ub->qlen,
		loginfo->qthreshold);

	/* NLMSG_PUT contains a hidden goto nlmsg_failure !!! */
	nlh = NLMSG_PUT(ub->skb, 0, ub->qlen, ULOG_NL_EVENT,
			sizeof(*pm)+copy_len);
	ub->qlen++;

	pm = NLMSG_DATA(nlh);

	/* We might not have a timestamp, get one */
	if (skb->tstamp.tv64 == 0)
		__net_timestamp((struct sk_buff *)skb);

	/* copy hook, prefix, timestamp, payload, etc. */
	pm->data_len = copy_len;
	tv = ktime_to_timeval(skb->tstamp);
	put_unaligned(tv.tv_sec, &pm->timestamp_sec);
	put_unaligned(tv.tv_usec, &pm->timestamp_usec);
	put_unaligned(skb->mark, &pm->mark);
	pm->hook = hooknum;
	if (prefix != NULL)
		strncpy(pm->prefix, prefix, sizeof(pm->prefix));
	else if (loginfo->prefix[0] != '\0')
		strncpy(pm->prefix, loginfo->prefix, sizeof(pm->prefix));
	else
		*(pm->prefix) = '\0';

	if (in && in->hard_header_len > 0
	    && skb->mac_header != skb->network_header
	    && in->hard_header_len <= ULOG_MAC_LEN) {
		memcpy(pm->mac, skb_mac_header(skb), in->hard_header_len);
		pm->mac_len = in->hard_header_len;
	} else
		pm->mac_len = 0;

	if (in)
		strncpy(pm->indev_name, in->name, sizeof(pm->indev_name));
	else
		pm->indev_name[0] = '\0';

	if (out)
		strncpy(pm->outdev_name, out->name, sizeof(pm->outdev_name));
	else
		pm->outdev_name[0] = '\0';

	/* copy_len <= skb->len, so can't fail. */
	if (skb_copy_bits(skb, 0, pm->payload, copy_len) < 0)
		BUG();

	/* check if we are building multi-part messages */
	if (ub->qlen > 1)
		ub->lastnlh->nlmsg_flags |= NLM_F_MULTI;

	ub->lastnlh = nlh;

	/* if timer isn't already running, start it */
	if (!timer_pending(&ub->timer)) {
		ub->timer.expires = jiffies + flushtimeout * HZ / 100;
		add_timer(&ub->timer);
	}

	/* if threshold is reached, send message to userspace */
	if (ub->qlen >= loginfo->qthreshold) {
		if (loginfo->qthreshold > 1)
			nlh->nlmsg_type = NLMSG_DONE;
		ulog_send(groupnum);
	}

	spin_unlock_bh(&ulog_lock);

	return;

nlmsg_failure:
	PRINTR("ipt_ULOG: error during NLMSG_PUT\n");

alloc_failure:
	PRINTR("ipt_ULOG: Error building netlink message\n");

	spin_unlock_bh(&ulog_lock);
}

static unsigned int ipt_ulog_target(struct sk_buff **pskb,
				    const struct net_device *in,
				    const struct net_device *out,
				    unsigned int hooknum,
				    const struct xt_target *target,
				    const void *targinfo)
{
	struct ipt_ulog_info *loginfo = (struct ipt_ulog_info *) targinfo;

	ipt_ulog_packet(hooknum, *pskb, in, out, loginfo, NULL);

	return XT_CONTINUE;
}

static void ipt_logfn(unsigned int pf,
		      unsigned int hooknum,
		      const struct sk_buff *skb,
		      const struct net_device *in,
		      const struct net_device *out,
		      const struct nf_loginfo *li,
		      const char *prefix)
{
	struct ipt_ulog_info loginfo;

	if (!li || li->type != NF_LOG_TYPE_ULOG) {
		loginfo.nl_group = ULOG_DEFAULT_NLGROUP;
		loginfo.copy_range = 0;
		loginfo.qthreshold = ULOG_DEFAULT_QTHRESHOLD;
		loginfo.prefix[0] = '\0';
	} else {
		loginfo.nl_group = li->u.ulog.group;
		loginfo.copy_range = li->u.ulog.copy_len;
		loginfo.qthreshold = li->u.ulog.qthreshold;
		strlcpy(loginfo.prefix, prefix, sizeof(loginfo.prefix));
	}

	ipt_ulog_packet(hooknum, skb, in, out, &loginfo, prefix);
}

static bool ipt_ulog_checkentry(const char *tablename,
				const void *e,
				const struct xt_target *target,
				void *targinfo,
				unsigned int hookmask)
{
	const struct ipt_ulog_info *loginfo = targinfo;

	if (loginfo->prefix[sizeof(loginfo->prefix) - 1] != '\0') {
		DEBUGP("ipt_ULOG: prefix term %i\n",
		       loginfo->prefix[sizeof(loginfo->prefix) - 1]);
		return false;
	}
	if (loginfo->qthreshold > ULOG_MAX_QLEN) {
		DEBUGP("ipt_ULOG: queue threshold %i > MAX_QLEN\n",
			loginfo->qthreshold);
		return false;
	}
	return true;
}

#ifdef CONFIG_COMPAT
struct compat_ipt_ulog_info {
	compat_uint_t	nl_group;
	compat_size_t	copy_range;
	compat_size_t	qthreshold;
	char		prefix[ULOG_PREFIX_LEN];
};

static void compat_from_user(void *dst, void *src)
{
	const struct compat_ipt_ulog_info *cl = src;
	struct ipt_ulog_info l = {
		.nl_group	= cl->nl_group,
		.copy_range	= cl->copy_range,
		.qthreshold	= cl->qthreshold,
	};

	memcpy(l.prefix, cl->prefix, sizeof(l.prefix));
	memcpy(dst, &l, sizeof(l));
}

static int compat_to_user(void __user *dst, void *src)
{
	const struct ipt_ulog_info *l = src;
	struct compat_ipt_ulog_info cl = {
		.nl_group	= l->nl_group,
		.copy_range	= l->copy_range,
		.qthreshold	= l->qthreshold,
	};

	memcpy(cl.prefix, l->prefix, sizeof(cl.prefix));
	return copy_to_user(dst, &cl, sizeof(cl)) ? -EFAULT : 0;
}
#endif /* CONFIG_COMPAT */

static struct xt_target ipt_ulog_reg = {
	.name		= "ULOG",
	.family		= AF_INET,
	.target		= ipt_ulog_target,
	.targetsize	= sizeof(struct ipt_ulog_info),
	.checkentry	= ipt_ulog_checkentry,
#ifdef CONFIG_COMPAT
	.compatsize	= sizeof(struct compat_ipt_ulog_info),
	.compat_from_user = compat_from_user,
	.compat_to_user	= compat_to_user,
#endif
	.me		= THIS_MODULE,
};

static struct nf_logger ipt_ulog_logger = {
	.name		= "ipt_ULOG",
	.logfn		= ipt_logfn,
	.me		= THIS_MODULE,
};

static int __init ipt_ulog_init(void)
{
	int ret, i;

	DEBUGP("ipt_ULOG: init module\n");

	if (nlbufsiz > 128*1024) {
		printk("Netlink buffer has to be <= 128kB\n");
		return -EINVAL;
	}

	/* initialize ulog_buffers */
	for (i = 0; i < ULOG_MAXNLGROUPS; i++)
		setup_timer(&ulog_buffers[i].timer, ulog_timer, i);

	nflognl = netlink_kernel_create(NETLINK_NFLOG, ULOG_MAXNLGROUPS, NULL,
					NULL, THIS_MODULE);
	if (!nflognl)
		return -ENOMEM;

	ret = xt_register_target(&ipt_ulog_reg);
	if (ret < 0) {
		sock_release(nflognl->sk_socket);
		return ret;
	}
	if (nflog)
		nf_log_register(PF_INET, &ipt_ulog_logger);

	return 0;
}

static void __exit ipt_ulog_fini(void)
{
	ulog_buff_t *ub;
	int i;

	DEBUGP("ipt_ULOG: cleanup_module\n");

	if (nflog)
		nf_log_unregister(&ipt_ulog_logger);
	xt_unregister_target(&ipt_ulog_reg);
	sock_release(nflognl->sk_socket);

	/* remove pending timers and free allocated skb's */
	for (i = 0; i < ULOG_MAXNLGROUPS; i++) {
		ub = &ulog_buffers[i];
		if (timer_pending(&ub->timer)) {
			DEBUGP("timer was pending, deleting\n");
			del_timer(&ub->timer);
		}

		if (ub->skb) {
			kfree_skb(ub->skb);
			ub->skb = NULL;
		}
	}
}

module_init(ipt_ulog_init);
module_exit(ipt_ulog_fini);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* netfilter module for userspace packet logging daemons
	3	*
	4	* (C) 2000-2004 by Harald Welte <laforge@netfilter.org>
1da177e4 LT	5	* (C) 1999-2001 Paul `Rusty' Russell
	6	* (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License version 2 as
	10	* published by the Free Software Foundation.
	11	*
e905a9ed YH	12	* This module accepts two parameters:
e905a9ed YH	13	*
1da177e4 LT	14	* nlbufsiz:
	15	* The parameter specifies how big the buffer for each netlink multicast
	16	* group is. e.g. If you say nlbufsiz=8192, up to eight kb of packets will
	17	* get accumulated in the kernel until they are sent to userspace. It is
	18	* NOT possible to allocate more than 128kB, and it is strongly discouraged,
	19	* because atomically allocating 128kB inside the network rx softirq is not
	20	* reliable. Please also keep in mind that this buffer size is allocated for
	21	* each nlgroup you are using, so the total kernel memory usage increases
	22	* by that factor.
	23	*
c2db2924 HE	24	* Actually you should use nlbufsiz a bit smaller than PAGE_SIZE, since
	25	* nlbufsiz is used with alloc_skb, which adds another
	26	* sizeof(struct skb_shared_info). Use NLMSG_GOODSIZE instead.
	27	*
1da177e4 LT	28	* flushtimeout:
	29	* Specify, after how many hundredths of a second the queue should be
	30	* flushed even if it is not full yet.
1da177e4 LT	31	*/
	32
	33	#include <linux/module.h>
1da177e4 LT	34	#include <linux/spinlock.h>
	35	#include <linux/socket.h>
	36	#include <linux/skbuff.h>
	37	#include <linux/kernel.h>
	38	#include <linux/timer.h>
	39	#include <linux/netlink.h>
	40	#include <linux/netdevice.h>
	41	#include <linux/mm.h>
	42	#include <linux/moduleparam.h>
	43	#include <linux/netfilter.h>
6709dbbb	44	#include <linux/netfilter/x_tables.h>
1da177e4	45	#include <linux/netfilter_ipv4/ipt_ULOG.h>
1da177e4 LT	46	#include <net/sock.h>
1da177e4 LT	47	#include <linux/bitops.h>
01102e7c	48	#include <asm/unaligned.h>
1da177e4 LT	49
	50	MODULE_LICENSE("GPL");
	51	MODULE_AUTHOR("Harald Welte <laforge@gnumonks.org>");
	52	MODULE_DESCRIPTION("iptables userspace logging module");
4fdb3bb7	53	MODULE_ALIAS_NET_PF_PROTO(PF_NETLINK, NETLINK_NFLOG);
1da177e4 LT	54
	55	#define ULOG_NL_EVENT 111 /* Harald's favorite number */
	56	#define ULOG_MAXNLGROUPS 32 /* numer of nlgroups */
	57
	58	#if 0
	59	#define DEBUGP(format, args...) printk("%s:%s:" format, \
e905a9ed	60	__FILE__, __FUNCTION__ , ## args)
1da177e4 LT	61	#else
	62	#define DEBUGP(format, args...)
	63	#endif
	64
	65	#define PRINTR(format, args...) do { if (net_ratelimit()) printk(format , ## args); } while (0)
	66
c2db2924	67	static unsigned int nlbufsiz = NLMSG_GOODSIZE;
e7be6994	68	module_param(nlbufsiz, uint, 0400);
1da177e4 LT	69	MODULE_PARM_DESC(nlbufsiz, "netlink buffer size");
	70
	71	static unsigned int flushtimeout = 10;
e7be6994	72	module_param(flushtimeout, uint, 0600);
1da177e4 LT	73	MODULE_PARM_DESC(flushtimeout, "buffer flush timeout (hundredths of a second)");
1da177e4 LT	74
e7be6994 PM	75	static int nflog = 1;
e7be6994 PM	76	module_param(nflog, bool, 0400);
1da177e4 LT	77	MODULE_PARM_DESC(nflog, "register as internal netfilter logging module");
	78
	79	/* global data structures */
	80
	81	typedef struct {
	82	unsigned int qlen; /* number of nlmsgs' in the skb */
	83	struct nlmsghdr lastnlh; / netlink header of last msg in skb */
	84	struct sk_buff skb; / the pre-allocated skb */
	85	struct timer_list timer; /* the timer function */
	86	} ulog_buff_t;
	87
	88	static ulog_buff_t ulog_buffers[ULOG_MAXNLGROUPS]; /* array of buffers */
	89
e45b1be8 PM	90	static struct sock nflognl; / our socket */
e45b1be8 PM	91	static DEFINE_SPINLOCK(ulog_lock); /* spinlock */
1da177e4 LT	92
	93	/* send one ulog_buff_t to userspace */
	94	static void ulog_send(unsigned int nlgroupnum)
	95	{
	96	ulog_buff_t *ub = &ulog_buffers[nlgroupnum];
	97
	98	if (timer_pending(&ub->timer)) {
	99	DEBUGP("ipt_ULOG: ulog_send: timer was pending, deleting\n");
	100	del_timer(&ub->timer);
	101	}
	102
dcb7cd97 MH	103	if (!ub->skb) {
	104	DEBUGP("ipt_ULOG: ulog_send: nothing to send\n");
	105	return;
	106	}
	107
1da177e4 LT	108	/* last nlmsg needs NLMSG_DONE */
	109	if (ub->qlen > 1)
	110	ub->lastnlh->nlmsg_type = NLMSG_DONE;
	111
ac6d439d PM	112	NETLINK_CB(ub->skb).dst_group = nlgroupnum + 1;
	113	DEBUGP("ipt_ULOG: throwing %d packets to netlink group %u\n",
	114	ub->qlen, nlgroupnum + 1);
	115	netlink_broadcast(nflognl, ub->skb, 0, nlgroupnum + 1, GFP_ATOMIC);
1da177e4 LT	116
	117	ub->qlen = 0;
	118	ub->skb = NULL;
	119	ub->lastnlh = NULL;
1da177e4 LT	120	}
	121
	122
	123	/* timer function to flush queue in flushtimeout time */
	124	static void ulog_timer(unsigned long data)
	125	{
	126	DEBUGP("ipt_ULOG: timer function called, calling ulog_send\n");
	127
	128	/* lock to protect against somebody modifying our structure
	129	* from ipt_ulog_target at the same time */
e45b1be8	130	spin_lock_bh(&ulog_lock);
1da177e4	131	ulog_send(data);
e45b1be8	132	spin_unlock_bh(&ulog_lock);
1da177e4 LT	133	}
	134
	135	static struct sk_buff *ulog_alloc_skb(unsigned int size)
	136	{
	137	struct sk_buff *skb;
ad2ad0f9	138	unsigned int n;
1da177e4 LT	139
	140	/* alloc skb which should be big enough for a whole
	141	* multipart message. WARNING: has to be <= 131000
	142	* due to slab allocator restrictions */
	143
ad2ad0f9 PM	144	n = max(size, nlbufsiz);
ad2ad0f9 PM	145	skb = alloc_skb(n, GFP_ATOMIC);
1da177e4	146	if (!skb) {
ad2ad0f9	147	PRINTR("ipt_ULOG: can't alloc whole buffer %ub!\n", n);
1da177e4	148
ad2ad0f9	149	if (n > size) {
e905a9ed	150	/* try to allocate only as much as we need for
ad2ad0f9	151	* current packet */
1da177e4	152
ad2ad0f9 PM	153	skb = alloc_skb(size, GFP_ATOMIC);
	154	if (!skb)
	155	PRINTR("ipt_ULOG: can't even allocate %ub\n",
	156	size);
	157	}
1da177e4 LT	158	}
	159
	160	return skb;
	161	}
	162
	163	static void ipt_ulog_packet(unsigned int hooknum,
	164	const struct sk_buff *skb,
	165	const struct net_device *in,
	166	const struct net_device *out,
	167	const struct ipt_ulog_info *loginfo,
	168	const char *prefix)
	169	{
	170	ulog_buff_t *ub;
	171	ulog_packet_msg_t *pm;
	172	size_t size, copy_len;
	173	struct nlmsghdr *nlh;
b7aa0bf7	174	struct timeval tv;
1da177e4 LT	175
	176	/* ffs == find first bit set, necessary because userspace
	177	* is already shifting groupnumber, but we need unshifted.
	178	* ffs() returns [1..32], we need [0..31] */
	179	unsigned int groupnum = ffs(loginfo->nl_group) - 1;
	180
	181	/* calculate the size of the skb needed */
7c4e36bc	182	if (loginfo->copy_range == 0 \|\| loginfo->copy_range > skb->len)
1da177e4	183	copy_len = skb->len;
7c4e36bc	184	else
1da177e4	185	copy_len = loginfo->copy_range;
1da177e4 LT	186
	187	size = NLMSG_SPACE(sizeof(*pm) + copy_len);
	188
	189	ub = &ulog_buffers[groupnum];
e905a9ed	190
e45b1be8	191	spin_lock_bh(&ulog_lock);
1da177e4 LT	192
	193	if (!ub->skb) {
	194	if (!(ub->skb = ulog_alloc_skb(size)))
	195	goto alloc_failure;
	196	} else if (ub->qlen >= loginfo->qthreshold \|\|
	197	size > skb_tailroom(ub->skb)) {
e905a9ed	198	/* either the queue len is too high or we don't have
1da177e4 LT	199	* enough room in nlskb left. send it to userspace. */
	200
	201	ulog_send(groupnum);
	202
	203	if (!(ub->skb = ulog_alloc_skb(size)))
	204	goto alloc_failure;
	205	}
	206
e905a9ed	207	DEBUGP("ipt_ULOG: qlen %d, qthreshold %d\n", ub->qlen,
1da177e4 LT	208	loginfo->qthreshold);
	209
	210	/* NLMSG_PUT contains a hidden goto nlmsg_failure !!! */
e905a9ed	211	nlh = NLMSG_PUT(ub->skb, 0, ub->qlen, ULOG_NL_EVENT,
1da177e4 LT	212	sizeof(*pm)+copy_len);
	213	ub->qlen++;
	214
	215	pm = NLMSG_DATA(nlh);
	216
	217	/* We might not have a timestamp, get one */
b7aa0bf7	218	if (skb->tstamp.tv64 == 0)
a61bbcf2	219	__net_timestamp((struct sk_buff *)skb);
1da177e4 LT	220
	221	/* copy hook, prefix, timestamp, payload, etc. */
	222	pm->data_len = copy_len;
b7aa0bf7 ED	223	tv = ktime_to_timeval(skb->tstamp);
	224	put_unaligned(tv.tv_sec, &pm->timestamp_sec);
	225	put_unaligned(tv.tv_usec, &pm->timestamp_usec);
01102e7c	226	put_unaligned(skb->mark, &pm->mark);
1da177e4 LT	227	pm->hook = hooknum;
	228	if (prefix != NULL)
	229	strncpy(pm->prefix, prefix, sizeof(pm->prefix));
	230	else if (loginfo->prefix[0] != '\0')
	231	strncpy(pm->prefix, loginfo->prefix, sizeof(pm->prefix));
	232	else
	233	*(pm->prefix) = '\0';
	234
	235	if (in && in->hard_header_len > 0
b0e380b1	236	&& skb->mac_header != skb->network_header
1da177e4	237	&& in->hard_header_len <= ULOG_MAC_LEN) {
98e399f8	238	memcpy(pm->mac, skb_mac_header(skb), in->hard_header_len);
1da177e4 LT	239	pm->mac_len = in->hard_header_len;
	240	} else
	241	pm->mac_len = 0;
	242
	243	if (in)
	244	strncpy(pm->indev_name, in->name, sizeof(pm->indev_name));
	245	else
	246	pm->indev_name[0] = '\0';
	247
	248	if (out)
	249	strncpy(pm->outdev_name, out->name, sizeof(pm->outdev_name));
	250	else
	251	pm->outdev_name[0] = '\0';
	252
	253	/* copy_len <= skb->len, so can't fail. */
	254	if (skb_copy_bits(skb, 0, pm->payload, copy_len) < 0)
	255	BUG();
e905a9ed	256
1da177e4	257	/* check if we are building multi-part messages */
7c4e36bc	258	if (ub->qlen > 1)
1da177e4	259	ub->lastnlh->nlmsg_flags \|= NLM_F_MULTI;
1da177e4 LT	260
	261	ub->lastnlh = nlh;
	262
	263	/* if timer isn't already running, start it */
	264	if (!timer_pending(&ub->timer)) {
	265	ub->timer.expires = jiffies + flushtimeout * HZ / 100;
	266	add_timer(&ub->timer);
	267	}
	268
	269	/* if threshold is reached, send message to userspace */
	270	if (ub->qlen >= loginfo->qthreshold) {
	271	if (loginfo->qthreshold > 1)
	272	nlh->nlmsg_type = NLMSG_DONE;
	273	ulog_send(groupnum);
	274	}
	275
e45b1be8	276	spin_unlock_bh(&ulog_lock);
1da177e4 LT	277
	278	return;
	279
	280	nlmsg_failure:
	281	PRINTR("ipt_ULOG: error during NLMSG_PUT\n");
	282
	283	alloc_failure:
	284	PRINTR("ipt_ULOG: Error building netlink message\n");
	285
e45b1be8	286	spin_unlock_bh(&ulog_lock);
1da177e4 LT	287	}
	288
	289	static unsigned int ipt_ulog_target(struct sk_buff **pskb,
	290	const struct net_device *in,
	291	const struct net_device *out,
	292	unsigned int hooknum,
c4986734	293	const struct xt_target *target,
fe1cb108	294	const void *targinfo)
1da177e4 LT	295	{
	296	struct ipt_ulog_info loginfo = (struct ipt_ulog_info ) targinfo;
	297
	298	ipt_ulog_packet(hooknum, *pskb, in, out, loginfo, NULL);
e905a9ed	299
6709dbbb	300	return XT_CONTINUE;
1da177e4	301	}
e905a9ed	302
608c8e4f HW	303	static void ipt_logfn(unsigned int pf,
608c8e4f HW	304	unsigned int hooknum,
1da177e4 LT	305	const struct sk_buff *skb,
	306	const struct net_device *in,
	307	const struct net_device *out,
608c8e4f	308	const struct nf_loginfo *li,
1da177e4 LT	309	const char *prefix)
1da177e4 LT	310	{
608c8e4f HW	311	struct ipt_ulog_info loginfo;
	312
	313	if (!li \|\| li->type != NF_LOG_TYPE_ULOG) {
	314	loginfo.nl_group = ULOG_DEFAULT_NLGROUP;
	315	loginfo.copy_range = 0;
	316	loginfo.qthreshold = ULOG_DEFAULT_QTHRESHOLD;
	317	loginfo.prefix[0] = '\0';
	318	} else {
	319	loginfo.nl_group = li->u.ulog.group;
	320	loginfo.copy_range = li->u.ulog.copy_len;
	321	loginfo.qthreshold = li->u.ulog.qthreshold;
	322	strlcpy(loginfo.prefix, prefix, sizeof(loginfo.prefix));
	323	}
1da177e4 LT	324
	325	ipt_ulog_packet(hooknum, skb, in, out, &loginfo, prefix);
	326	}
	327
e1931b78 JE	328	static bool ipt_ulog_checkentry(const char *tablename,
	329	const void *e,
	330	const struct xt_target *target,
	331	void *targinfo,
	332	unsigned int hookmask)
1da177e4	333	{
a47362a2	334	const struct ipt_ulog_info *loginfo = targinfo;
1da177e4	335
1da177e4 LT	336	if (loginfo->prefix[sizeof(loginfo->prefix) - 1] != '\0') {
	337	DEBUGP("ipt_ULOG: prefix term %i\n",
	338	loginfo->prefix[sizeof(loginfo->prefix) - 1]);
e1931b78	339	return false;
1da177e4	340	}
1da177e4 LT	341	if (loginfo->qthreshold > ULOG_MAX_QLEN) {
	342	DEBUGP("ipt_ULOG: queue threshold %i > MAX_QLEN\n",
	343	loginfo->qthreshold);
e1931b78	344	return false;
1da177e4	345	}
e1931b78	346	return true;
1da177e4 LT	347	}
1da177e4 LT	348
b076deb8 PM	349	#ifdef CONFIG_COMPAT
	350	struct compat_ipt_ulog_info {
	351	compat_uint_t nl_group;
	352	compat_size_t copy_range;
	353	compat_size_t qthreshold;
	354	char prefix[ULOG_PREFIX_LEN];
	355	};
	356
	357	static void compat_from_user(void dst, void src)
	358	{
a47362a2	359	const struct compat_ipt_ulog_info *cl = src;
b076deb8 PM	360	struct ipt_ulog_info l = {
	361	.nl_group = cl->nl_group,
	362	.copy_range = cl->copy_range,
	363	.qthreshold = cl->qthreshold,
	364	};
	365
	366	memcpy(l.prefix, cl->prefix, sizeof(l.prefix));
	367	memcpy(dst, &l, sizeof(l));
	368	}
	369
	370	static int compat_to_user(void __user dst, void src)
	371	{
a47362a2	372	const struct ipt_ulog_info *l = src;
b076deb8 PM	373	struct compat_ipt_ulog_info cl = {
	374	.nl_group = l->nl_group,
	375	.copy_range = l->copy_range,
	376	.qthreshold = l->qthreshold,
	377	};
	378
	379	memcpy(cl.prefix, l->prefix, sizeof(cl.prefix));
	380	return copy_to_user(dst, &cl, sizeof(cl)) ? -EFAULT : 0;
	381	}
	382	#endif /* CONFIG_COMPAT */
	383
6709dbbb	384	static struct xt_target ipt_ulog_reg = {
1da177e4	385	.name = "ULOG",
6709dbbb	386	.family = AF_INET,
1da177e4	387	.target = ipt_ulog_target,
1d5cd909	388	.targetsize = sizeof(struct ipt_ulog_info),
1da177e4	389	.checkentry = ipt_ulog_checkentry,
b076deb8 PM	390	#ifdef CONFIG_COMPAT
	391	.compatsize = sizeof(struct compat_ipt_ulog_info),
	392	.compat_from_user = compat_from_user,
	393	.compat_to_user = compat_to_user,
	394	#endif
1da177e4 LT	395	.me = THIS_MODULE,
	396	};
	397
608c8e4f HW	398	static struct nf_logger ipt_ulog_logger = {
608c8e4f HW	399	.name = "ipt_ULOG",
1d5cd909	400	.logfn = ipt_logfn,
608c8e4f HW	401	.me = THIS_MODULE,
	402	};
	403
65b4b4e8	404	static int __init ipt_ulog_init(void)
1da177e4	405	{
e1fd0586	406	int ret, i;
1da177e4 LT	407
	408	DEBUGP("ipt_ULOG: init module\n");
	409
e7be6994	410	if (nlbufsiz > 128*1024) {
1da177e4 LT	411	printk("Netlink buffer has to be <= 128kB\n");
	412	return -EINVAL;
	413	}
	414
	415	/* initialize ulog_buffers */
e6f689db PM	416	for (i = 0; i < ULOG_MAXNLGROUPS; i++)
e6f689db PM	417	setup_timer(&ulog_buffers[i].timer, ulog_timer, i);
1da177e4	418
06628607	419	nflognl = netlink_kernel_create(NETLINK_NFLOG, ULOG_MAXNLGROUPS, NULL,
af65bdfc	420	NULL, THIS_MODULE);
1da177e4 LT	421	if (!nflognl)
	422	return -ENOMEM;
	423
6709dbbb	424	ret = xt_register_target(&ipt_ulog_reg);
e1fd0586	425	if (ret < 0) {
1da177e4	426	sock_release(nflognl->sk_socket);
e1fd0586	427	return ret;
1da177e4 LT	428	}
1da177e4 LT	429	if (nflog)
608c8e4f	430	nf_log_register(PF_INET, &ipt_ulog_logger);
e905a9ed	431
1da177e4 LT	432	return 0;
	433	}
	434
65b4b4e8	435	static void __exit ipt_ulog_fini(void)
1da177e4 LT	436	{
	437	ulog_buff_t *ub;
	438	int i;
	439
	440	DEBUGP("ipt_ULOG: cleanup_module\n");
	441
	442	if (nflog)
e92ad99c	443	nf_log_unregister(&ipt_ulog_logger);
6709dbbb	444	xt_unregister_target(&ipt_ulog_reg);
1da177e4 LT	445	sock_release(nflognl->sk_socket);
	446
	447	/* remove pending timers and free allocated skb's */
	448	for (i = 0; i < ULOG_MAXNLGROUPS; i++) {
	449	ub = &ulog_buffers[i];
	450	if (timer_pending(&ub->timer)) {
	451	DEBUGP("timer was pending, deleting\n");
	452	del_timer(&ub->timer);
	453	}
	454
	455	if (ub->skb) {
	456	kfree_skb(ub->skb);
	457	ub->skb = NULL;
	458	}
	459	}
1da177e4 LT	460	}
1da177e4 LT	461
65b4b4e8 AM	462	module_init(ipt_ulog_init);
65b4b4e8 AM	463	module_exit(ipt_ulog_fini);