/* Kernel module to match one of a list of TCP/UDP(-Lite)/SCTP/DCCP ports:   ports are in the same place so we can treat them as equal. *//* (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. */#include <linux/module.h>#include <linux/types.h>#include <linux/udp.h>#include <linux/skbuff.h>#include <linux/in.h>#include <linux/netfilter/xt_multiport.h>#include <linux/netfilter/x_tables.h>#include <linux/netfilter_ipv4/ip_tables.h>#include <linux/netfilter_ipv6/ip6_tables.h>MODULE_LICENSE("GPL");MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");MODULE_DESCRIPTION("x_tables multiple port match module");MODULE_ALIAS("ipt_multiport");MODULE_ALIAS("ip6t_multiport");#if 0#define duprintf(format, args...) printk(format , ## args)#else#define duprintf(format, args...)#endif/* Returns 1 if the port is matched by the test, 0 otherwise. */static inline boolports_match(const u_int16_t *portlist, enum xt_multiport_flags flags,	    u_int8_t count, u_int16_t src, u_int16_t dst){	unsigned int i;	for (i = 0; i < count; i++) {		if (flags != XT_MULTIPORT_DESTINATION && portlist[i] == src)			return true;		if (flags != XT_MULTIPORT_SOURCE && portlist[i] == dst)			return true;	}	return false;}/* Returns 1 if the port is matched by the test, 0 otherwise. */static inline boolports_match_v1(const struct xt_multiport_v1 *minfo,	       u_int16_t src, u_int16_t dst){	unsigned int i;	u_int16_t s, e;	for (i = 0; i < minfo->count; i++) {		s = minfo->ports[i];		if (minfo->pflags[i]) {			/* range port matching */			e = minfo->ports[++i];			duprintf("src or dst matches with %d-%d?\n", s, e);			if (minfo->flags == XT_MULTIPORT_SOURCE			    && src >= s && src <= e)				return true ^ minfo->invert;			if (minfo->flags == XT_MULTIPORT_DESTINATION			    && dst >= s && dst <= e)				return true ^ minfo->invert;			if (minfo->flags == XT_MULTIPORT_EITHER			    && ((dst >= s && dst <= e)				|| (src >= s && src <= e)))				return true ^ minfo->invert;		} else {			/* exact port matching */			duprintf("src or dst matches with %d?\n", s);			if (minfo->flags == XT_MULTIPORT_SOURCE			    && src == s)				return true ^ minfo->invert;			if (minfo->flags == XT_MULTIPORT_DESTINATION			    && dst == s)				return true ^ minfo->invert;			if (minfo->flags == XT_MULTIPORT_EITHER			    && (src == s || dst == s))				return true ^ minfo->invert;		}	}	return minfo->invert;}static boolmatch(const struct sk_buff *skb,      const struct net_device *in,      const struct net_device *out,      const struct xt_match *match,      const void *matchinfo,      int offset,      unsigned int protoff,      bool *hotdrop){	__be16 _ports[2], *pptr;	const struct xt_multiport *multiinfo = matchinfo;	if (offset)		return false;	pptr = skb_header_pointer(skb, protoff, sizeof(_ports), _ports);	if (pptr == NULL) {		/* We've been asked to examine this packet, and we		 * can't.  Hence, no choice but to drop.		 */		duprintf("xt_multiport: Dropping evil offset=0 tinygram.\n");		*hotdrop = true;		return false;	}	return ports_match(multiinfo->ports,			   multiinfo->flags, multiinfo->count,			   ntohs(pptr[0]), ntohs(pptr[1]));}static boolmatch_v1(const struct sk_buff *skb,	 const struct net_device *in,	 const struct net_device *out,	 const struct xt_match *match,	 const void *matchinfo,	 int offset,	 unsigned int protoff,	 bool *hotdrop){	__be16 _ports[2], *pptr;	const struct xt_multiport_v1 *multiinfo = matchinfo;	if (offset)		return false;	pptr = skb_header_pointer(skb, protoff, sizeof(_ports), _ports);	if (pptr == NULL) {		/* We've been asked to examine this packet, and we		 * can't.  Hence, no choice but to drop.		 */		duprintf("xt_multiport: Dropping evil offset=0 tinygram.\n");		*hotdrop = true;		return false;	}	return ports_match_v1(multiinfo, ntohs(pptr[0]), ntohs(pptr[1]));}static inline boolcheck(u_int16_t proto,      u_int8_t ip_invflags,      u_int8_t match_flags,      u_int8_t count){	/* Must specify supported protocol, no unknown flags or bad count */	return (proto == IPPROTO_TCP || proto == IPPROTO_UDP		|| proto == IPPROTO_UDPLITE		|| proto == IPPROTO_SCTP || proto == IPPROTO_DCCP)		&& !(ip_invflags & XT_INV_PROTO)		&& (match_flags == XT_MULTIPORT_SOURCE		    || match_flags == XT_MULTIPORT_DESTINATION		    || match_flags == XT_MULTIPORT_EITHER)		&& count <= XT_MULTI_PORTS;}/* Called when user tries to insert an entry of this type. */static boolcheckentry(const char *tablename,	   const void *info,	   const struct xt_match *match,	   void *matchinfo,	   unsigned int hook_mask){	const struct ipt_ip *ip = info;	const struct xt_multiport *multiinfo = matchinfo;	return check(ip->proto, ip->invflags, multiinfo->flags,		     multiinfo->count);}static boolcheckentry_v1(const char *tablename,	      const void *info,	      const struct xt_match *match,	      void *matchinfo,	      unsigned int hook_mask){	const struct ipt_ip *ip = info;	const struct xt_multiport_v1 *multiinfo = matchinfo;	return check(ip->proto, ip->invflags, multiinfo->flags,		     multiinfo->count);}static boolcheckentry6(const char *tablename,	    const void *info,	    const struct xt_match *match,	    void *matchinfo,	    unsigned int hook_mask){	const struct ip6t_ip6 *ip = info;	const struct xt_multiport *multiinfo = matchinfo;	return check(ip->proto, ip->invflags, multiinfo->flags,		     multiinfo->count);}static boolcheckentry6_v1(const char *tablename,	       const void *info,	       const struct xt_match *match,	       void *matchinfo,	       unsigned int hook_mask){	const struct ip6t_ip6 *ip = info;	const struct xt_multiport_v1 *multiinfo = matchinfo;	return check(ip->proto, ip->invflags, multiinfo->flags,		     multiinfo->count);}static struct xt_match xt_multiport_match[] __read_mostly = {	{		.name		= "multiport",		.family		= AF_INET,		.revision	= 0,		.checkentry	= checkentry,		.match		= match,		.matchsize	= sizeof(struct xt_multiport),		.me		= THIS_MODULE,	},	{		.name		= "multiport",		.family		= AF_INET,		.revision	= 1,		.checkentry	= checkentry_v1,		.match		= match_v1,		.matchsize	= sizeof(struct xt_multiport_v1),		.me		= THIS_MODULE,	},	{		.name		= "multiport",		.family		= AF_INET6,		.revision	= 0,		.checkentry	= checkentry6,		.match		= match,		.matchsize	= sizeof(struct xt_multiport),		.me		= THIS_MODULE,	},	{		.name		= "multiport",		.family		= AF_INET6,		.revision	= 1,		.checkentry	= checkentry6_v1,		.match		= match_v1,		.matchsize	= sizeof(struct xt_multiport_v1),		.me		= THIS_MODULE,	},};static int __init xt_multiport_init(void){	return xt_register_matches(xt_multiport_match,				   ARRAY_SIZE(xt_multiport_match));}static void __exit xt_multiport_fini(void){	xt_unregister_matches(xt_multiport_match,			      ARRAY_SIZE(xt_multiport_match));}module_init(xt_multiport_init);module_exit(xt_multiport_fini);