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Commit 78d9f4d4 authored by Matthias Schiffer's avatar Matthias Schiffer Committed by Pablo Neira Ayuso
Browse files

netfilter: ebtables: add support for matching IGMP type 



We already have ICMPv6 type/code matches (which can be used to distinguish
different types of MLD packets). Add support for IPv4 IGMP matches in the
same way.

Signed-off-by: default avatarMatthias Schiffer <mschiffer@universe-factory.net>
Acked-by: default avatarFlorian Westphal <fw@strlen.de>
Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
parent 5adc1668

include/uapi/linux/netfilter_bridge/ebt_ip.h

+3 −1
Original line number Diff line number Diff line
@@ -25,8 +25,9 @@ 
#define EBT_IP_SPORT 0x10

#define EBT_IP_DPORT 0x20

#define EBT_IP_ICMP 0x40

#define EBT_IP_IGMP 0x80

#define EBT_IP_MASK (EBT_IP_SOURCE | EBT_IP_DEST | EBT_IP_TOS | EBT_IP_PROTO |\

		     EBT_IP_SPORT | EBT_IP_DPORT | EBT_IP_ICMP)

		     EBT_IP_SPORT | EBT_IP_DPORT | EBT_IP_ICMP | EBT_IP_IGMP)

#define EBT_IP_MATCH "ip"



/* the same values are used for the invflags */
@@ -42,6 +43,7 @@ struct ebt_ip_info { 
	union {

		__u16 sport[2];

		__u8 icmp_type[2];

		__u8 igmp_type[2];

	};

	union {

		__u16 dport[2];

net/bridge/netfilter/ebt_ip.c

+17 −2
Original line number Diff line number Diff line
@@ -28,6 +28,9 @@ union pkthdr { 
		u8 type;

		u8 code;

	} icmphdr;

	struct {

		u8 type;

	} igmphdr;

};



static bool
@@ -57,12 +60,12 @@ ebt_ip_mt(const struct sk_buff *skb, struct xt_action_param *par) 
		if (NF_INVF(info, EBT_IP_PROTO, info->protocol != ih->protocol))

			return false;

		if (!(info->bitmask & (EBT_IP_DPORT | EBT_IP_SPORT |

				       EBT_IP_ICMP)))

				       EBT_IP_ICMP | EBT_IP_IGMP)))

			return true;

		if (ntohs(ih->frag_off) & IP_OFFSET)

			return false;



		/* min icmp headersize is 4, so sizeof(_pkthdr) is ok. */

		/* min icmp/igmp headersize is 4, so sizeof(_pkthdr) is ok. */

		pptr = skb_header_pointer(skb, ih->ihl*4,

					  sizeof(_pkthdr), &_pkthdr);

		if (pptr == NULL)
@@ -88,6 +91,11 @@ ebt_ip_mt(const struct sk_buff *skb, struct xt_action_param *par) 
			    pptr->icmphdr.code < info->icmp_code[0] ||

			    pptr->icmphdr.code > info->icmp_code[1]))

			return false;

		if ((info->bitmask & EBT_IP_IGMP) &&

		    NF_INVF(info, EBT_IP_IGMP,

			    pptr->igmphdr.type < info->igmp_type[0] ||

			    pptr->igmphdr.type > info->igmp_type[1]))

			return false;

	}

	return true;

}
@@ -124,6 +132,13 @@ static int ebt_ip_mt_check(const struct xt_mtchk_param *par) 
		    info->icmp_code[0] > info->icmp_code[1])

			return -EINVAL;

	}

	if (info->bitmask & EBT_IP_IGMP) {

		if ((info->invflags & EBT_IP_PROTO) ||

		    info->protocol != IPPROTO_IGMP)

			return -EINVAL;

		if (info->igmp_type[0] > info->igmp_type[1])

			return -EINVAL;

	}

	return 0;

}