![Phil Oester](/assets/img/avatar_default.png)
Locally generated broadcast and multicast packets have pkttype set to PACKET_LOOPBACK instead of PACKET_BROADCAST or PACKET_MULTICAST. This causes the pkttype match to fail to match packets of either type. The below patch remedies this by using the daddr as a hint as to broadcast|multicast. While not pretty, this seems like the only way to solve the problem short of just noting this as a limitation of the match. This resolves netfilter bugzilla #484 Signed-off-by: Phil Oester <kernel@linuxace.com> Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
84 lines
1.9 KiB
C
84 lines
1.9 KiB
C
/* (C) 1999-2001 Michal Ludvig <michal@logix.cz>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/module.h>
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#include <linux/skbuff.h>
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#include <linux/if_ether.h>
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#include <linux/if_packet.h>
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#include <linux/in.h>
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#include <linux/ip.h>
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#include <linux/netfilter/xt_pkttype.h>
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#include <linux/netfilter/x_tables.h>
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Michal Ludvig <michal@logix.cz>");
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MODULE_DESCRIPTION("IP tables match to match on linklayer packet type");
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MODULE_ALIAS("ipt_pkttype");
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MODULE_ALIAS("ip6t_pkttype");
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static int match(const struct sk_buff *skb,
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const struct net_device *in,
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const struct net_device *out,
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const struct xt_match *match,
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const void *matchinfo,
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int offset,
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unsigned int protoff,
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int *hotdrop)
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{
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u_int8_t type;
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const struct xt_pkttype_info *info = matchinfo;
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if (skb->pkt_type == PACKET_LOOPBACK)
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type = (MULTICAST(skb->nh.iph->daddr)
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? PACKET_MULTICAST
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: PACKET_BROADCAST);
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else
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type = skb->pkt_type;
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return (type == info->pkttype) ^ info->invert;
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}
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static struct xt_match pkttype_match = {
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.name = "pkttype",
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.match = match,
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.matchsize = sizeof(struct xt_pkttype_info),
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.family = AF_INET,
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.me = THIS_MODULE,
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};
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static struct xt_match pkttype6_match = {
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.name = "pkttype",
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.match = match,
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.matchsize = sizeof(struct xt_pkttype_info),
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.family = AF_INET6,
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.me = THIS_MODULE,
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};
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static int __init xt_pkttype_init(void)
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{
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int ret;
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ret = xt_register_match(&pkttype_match);
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if (ret)
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return ret;
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ret = xt_register_match(&pkttype6_match);
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if (ret)
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xt_unregister_match(&pkttype_match);
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return ret;
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}
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static void __exit xt_pkttype_fini(void)
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{
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xt_unregister_match(&pkttype_match);
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xt_unregister_match(&pkttype6_match);
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}
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module_init(xt_pkttype_init);
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module_exit(xt_pkttype_fini);
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