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Kbuild	1020 B	-rw-r--r--
Makefile	14.31 KB	-rw-r--r--
Makefile.am	910 B	-rw-r--r--
Makefile.in	13.55 KB	-rw-r--r--
Mbuild	989 B	-rw-r--r--
compat_skbuff.h	325 B	-rw-r--r--
compat_user.h	262 B	-rw-r--r--
compat_xtables.c	1.18 KB	-rw-r--r--
compat_xtables.h	2.52 KB	-rw-r--r--
compat_xtnu.h	1.97 KB	-rw-r--r--
libxt_CHAOS.c	2.56 KB	-rw-r--r--
libxt_CHAOS.man	1 KB	-rw-r--r--
libxt_DELUDE.c	1.11 KB	-rw-r--r--
libxt_DELUDE.man	286 B	-rw-r--r--
libxt_DHCPMAC.c	2.55 KB	-rw-r--r--
libxt_DHCPMAC.man	1.2 KB	-rw-r--r--
libxt_DNETMAP.c	6.62 KB	-rw-r--r--
libxt_DNETMAP.man	7.71 KB	-rw-r--r--
libxt_ECHO.c	1.03 KB	-rw-r--r--
libxt_ECHO.man	141 B	-rw-r--r--
libxt_IPMARK.c	4.71 KB	-rw-r--r--
libxt_IPMARK.man	1.99 KB	-rw-r--r--
libxt_LOGMARK.c	3.27 KB	-rw-r--r--
libxt_LOGMARK.man	312 B	-rw-r--r--
libxt_SYSRQ.c	844 B	-rw-r--r--
libxt_SYSRQ.man	3.67 KB	-rw-r--r--
libxt_TARPIT.c	2.75 KB	-rw-r--r--
libxt_TARPIT.man	2.55 KB	-rw-r--r--
libxt_condition.c	2.5 KB	-rw-r--r--
libxt_condition.man	175 B	-rw-r--r--
libxt_dhcpmac.c	2.52 KB	-rw-r--r--
libxt_dhcpmac.man	207 B	-rw-r--r--
libxt_fuzzy.c	3.37 KB	-rw-r--r--
libxt_fuzzy.man	263 B	-rw-r--r--
libxt_geoip.c	8.21 KB	-rw-r--r--
libxt_geoip.man	1 KB	-rw-r--r--
libxt_gradm.c	2.3 KB	-rw-r--r--
libxt_gradm.man	225 B	-rw-r--r--
libxt_iface.c	7.21 KB	-rw-r--r--
libxt_iface.man	1.39 KB	-rw-r--r--
libxt_ipp2p.c	7.36 KB	-rw-r--r--
libxt_ipp2p.man	1.52 KB	-rw-r--r--
libxt_ipv4options.c	4.32 KB	-rw-r--r--
libxt_ipv4options.man	1.44 KB	-rw-r--r--
libxt_length2.c	4.69 KB	-rw-r--r--
libxt_length2.man	695 B	-rw-r--r--
libxt_lscan.c	2.64 KB	-rw-r--r--
libxt_lscan.man	1.58 KB	-rw-r--r--
libxt_psd.c	5.34 KB	-rw-r--r--
libxt_psd.man	720 B	-rw-r--r--
libxt_quota2.c	4.06 KB	-rw-r--r--
libxt_quota2.man	1.6 KB	-rw-r--r--
mac.c	572 B	-rw-r--r--
xt_CHAOS.c	6.29 KB	-rw-r--r--
xt_CHAOS.h	249 B	-rw-r--r--
xt_DELUDE.c	4.96 KB	-rw-r--r--
xt_DHCPMAC.c	4.18 KB	-rw-r--r--
xt_DHCPMAC.h	311 B	-rw-r--r--
xt_DNETMAP.c	25.22 KB	-rw-r--r--
xt_DNETMAP.h	402 B	-rw-r--r--
xt_ECHO.c	6.98 KB	-rw-r--r--
xt_IPMARK.c	2.75 KB	-rw-r--r--
xt_IPMARK.h	252 B	-rw-r--r--
xt_LOGMARK.c	3.96 KB	-rw-r--r--
xt_LOGMARK.h	209 B	-rw-r--r--
xt_SYSRQ.c	9.75 KB	-rw-r--r--
xt_TARPIT.c	14.94 KB	-rw-r--r--
xt_TARPIT.h	258 B	-rw-r--r--
xt_condition.c	6.75 KB	-rw-r--r--
xt_condition.h	276 B	-rw-r--r--
xt_fuzzy.c	4.65 KB	-rw-r--r--
xt_fuzzy.h	397 B	-rw-r--r--
xt_geoip.c	8.73 KB	-rw-r--r--
xt_geoip.h	1.34 KB	-rw-r--r--
xt_gradm.h	108 B	-rw-r--r--
xt_iface.c	3.32 KB	-rw-r--r--
xt_iface.h	596 B	-rw-r--r--
xt_ipp2p.c	23.63 KB	-rw-r--r--
xt_ipp2p.h	995 B	-rw-r--r--
xt_ipv4options.c	1.96 KB	-rw-r--r--
xt_ipv4options.h	581 B	-rw-r--r--
xt_length2.c	6.99 KB	-rw-r--r--
xt_length2.h	457 B	-rw-r--r--
xt_lscan.c	7.85 KB	-rw-r--r--
xt_lscan.h	200 B	-rw-r--r--
xt_psd.c	14.2 KB	-rw-r--r--
xt_psd.h	792 B	-rw-r--r--
xt_quota2.c	9 KB	-rw-r--r--
xt_quota2.h	478 B	-rw-r--r--

Code Editor : xt_DHCPMAC.c

/*
 *	"DHCPMAC" extensions for Xtables
 *	Copyright © Jan Engelhardt, 2008
 *
 *	This program is free software; you can redistribute it and/or
 *	modify it under the terms of the GNU General Public License; either
 *	version 2 of the License, or any later version, as published by the
 *	Free Software Foundation.
 */
#include <linux/ip.h>
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/types.h>
#include <linux/udp.h>
#include <net/ip.h>
#include <linux/netfilter/x_tables.h>
#include "xt_DHCPMAC.h"
#include "compat_xtables.h"

struct dhcp_message {
	uint8_t op, htype, hlen, hops;
	__be32 xid;
	__be16 secs, flags;
	__be32 ciaddr, yiaddr, siaddr, giaddr;
	char chaddr[16];
	/* Omitting all unneeded fields saves runtime memory */
	/* char sname[64], file[128]; */
};

static void ether_set(unsigned char *addr, const unsigned char *op,
    uint8_t mask)
{
	uint8_t lo_mask;
	unsigned int i;

for (i = 0; i < ETH_ALEN && mask > 0; ++i) {
		lo_mask = (mask >= 8) ? 8 : mask;
		/* FF << 4 >> 4 = 0F */
		lo_mask = (uint8_t)(~0U << lo_mask) >> lo_mask;
		addr[i] &= lo_mask;
		addr[i] |= op[i] & ~lo_mask;
		if (mask >= 8)
			mask -= 8;
		else
			mask = 0;
	}
}

static bool ether_cmp(const unsigned char *lh, const unsigned char *rh,
    uint8_t mask)
{
	uint8_t lo_mask;
	unsigned int i;
#define ZMAC_FMT "%02X:%02X:%02X:%02X:%02X:%02X"
#define ZMACHEX(s) s[0], s[1], s[2], s[3], s[4], s[5]

for (i = 0; i < ETH_ALEN && mask > 0; ++i) {
		lo_mask = (mask >= 8) ? 8 : mask;
		/* ~(0xFF << 4 >> 4) = ~0x0F = 0xF0 */
		lo_mask = ~((uint8_t)(~0U << lo_mask) >> lo_mask);
		if ((lh[i] ^ rh[i]) & lo_mask)
			return false;
		if (mask >= 8)
			mask -= 8;
		else
			mask = 0;
	}
	return true;
}

static bool
dhcpmac_mt(const struct sk_buff *skb, struct xt_action_param *par)
{
	const struct dhcpmac_info *info = par->matchinfo;
	const struct dhcp_message *dh;
	struct dhcp_message dhcpbuf;

dh = skb_header_pointer(skb, par->thoff + sizeof(struct udphdr),
	     sizeof(dhcpbuf), &dhcpbuf);
	if (dh == NULL)
		/*
		 * No hotdrop. This packet does not look like DHCP, but other
		 * matches may still have a valid reason to get their chance
		 * to match on this.
		 */
		return false;

return ether_cmp((const void *)dh->chaddr, info->addr, info->mask);
}

static unsigned int
dhcpmac_tg(struct sk_buff *skb, const struct xt_action_param *par)
{
	const struct dhcpmac_info *info = par->targinfo;
	struct dhcp_message dhcpbuf, *dh;
	struct udphdr udpbuf, *udph;
	unsigned int i;

if (!skb_make_writable(skb, 0))
		return NF_DROP;

udph = skb_header_pointer(skb, ip_hdrlen(skb),
	       sizeof(udpbuf), &udpbuf);
	if (udph == NULL)
		return NF_DROP;

dh = skb_header_pointer(skb, ip_hdrlen(skb) + sizeof(udpbuf),
	     sizeof(dhcpbuf), &dhcpbuf);
	if (dh == NULL)
		return NF_DROP;

for (i = 0; i < sizeof(dh->chaddr); i += 2)
		csum_replace2(&udph->check, *(const __be16 *)(dh->chaddr + i), 0);

ether_set(dh->chaddr, info->addr, info->mask);

for (i = 0; i < sizeof(dh->chaddr); i += 2)
		csum_replace2(&udph->check, 0, *(const __be16 *)(dh->chaddr + i));

return XT_CONTINUE;
}

static struct xt_target dhcpmac_tg_reg __read_mostly = {
	.name       = "DHCPMAC",
	.revision   = 0,
	.family     = NFPROTO_IPV4,
	.proto      = IPPROTO_UDP,
	.table      = "mangle",
	.target     = dhcpmac_tg,
	.targetsize = XT_ALIGN(sizeof(struct dhcpmac_info)),
	.me         = THIS_MODULE,
};

static struct xt_match dhcpmac_mt_reg __read_mostly = {
	.name       = "dhcpmac",
	.revision   = 0,
	.family     = NFPROTO_IPV4,
	.proto      = IPPROTO_UDP,
	.match      = dhcpmac_mt,
	.matchsize  = sizeof(struct dhcpmac_info),
	.me         = THIS_MODULE,
};

static int __init dhcpmac_init(void)
{
	int ret;

ret = xt_register_target(&dhcpmac_tg_reg);
	if (ret != 0)
		return ret;
	ret = xt_register_match(&dhcpmac_mt_reg);
	if (ret != 0) {
		xt_unregister_target(&dhcpmac_tg_reg);
		return ret;
	}
	return 0;
}

static void __exit dhcpmac_exit(void)
{
	xt_unregister_target(&dhcpmac_tg_reg);
	xt_unregister_match(&dhcpmac_mt_reg);
}

module_init(dhcpmac_init);
module_exit(dhcpmac_exit);
MODULE_DESCRIPTION("Xtables: Clamp DHCP MAC to packet MAC addresses");
MODULE_AUTHOR("Jan Engelhardt ");
MODULE_LICENSE("GPL");
MODULE_ALIAS("ipt_DHCPMAC");
MODULE_ALIAS("ipt_dhcpmac");

${this.title}

Code Editor : xt_DHCPMAC.c