155 строки
3.7 KiB
C
155 строки
3.7 KiB
C
/*
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* This module is used to copy security markings from packets
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* to connections, and restore security markings from connections
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* back to packets. This would normally be performed in conjunction
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* with the SECMARK target and state match.
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*
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* Based somewhat on CONNMARK:
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* Copyright (C) 2002,2004 MARA Systems AB <http://www.marasystems.com>
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* by Henrik Nordstrom <hno@marasystems.com>
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*
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* (C) 2006 Red Hat, Inc., James Morris <jmorris@redhat.com>
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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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*/
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#include <linux/module.h>
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#include <linux/skbuff.h>
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#include <linux/netfilter/x_tables.h>
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#include <linux/netfilter/xt_CONNSECMARK.h>
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#include <net/netfilter/nf_conntrack.h>
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#define PFX "CONNSECMARK: "
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("James Morris <jmorris@redhat.com>");
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MODULE_DESCRIPTION("ip[6]tables CONNSECMARK module");
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MODULE_ALIAS("ipt_CONNSECMARK");
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MODULE_ALIAS("ip6t_CONNSECMARK");
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/*
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* If the packet has a security mark and the connection does not, copy
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* the security mark from the packet to the connection.
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*/
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static void secmark_save(struct sk_buff *skb)
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{
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if (skb->secmark) {
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struct nf_conn *ct;
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enum ip_conntrack_info ctinfo;
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ct = nf_ct_get(skb, &ctinfo);
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if (ct && !ct->secmark)
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ct->secmark = skb->secmark;
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}
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}
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/*
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* If packet has no security mark, and the connection does, restore the
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* security mark from the connection to the packet.
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*/
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static void secmark_restore(struct sk_buff *skb)
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{
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if (!skb->secmark) {
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struct nf_conn *ct;
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enum ip_conntrack_info ctinfo;
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ct = nf_ct_get(skb, &ctinfo);
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if (ct && ct->secmark)
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skb->secmark = ct->secmark;
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}
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}
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static unsigned int target(struct sk_buff **pskb, const struct net_device *in,
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const struct net_device *out, unsigned int hooknum,
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const struct xt_target *target,
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const void *targinfo)
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{
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struct sk_buff *skb = *pskb;
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const struct xt_connsecmark_target_info *info = targinfo;
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switch (info->mode) {
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case CONNSECMARK_SAVE:
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secmark_save(skb);
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break;
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case CONNSECMARK_RESTORE:
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secmark_restore(skb);
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break;
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default:
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BUG();
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}
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return XT_CONTINUE;
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}
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static int checkentry(const char *tablename, const void *entry,
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const struct xt_target *target, void *targinfo,
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unsigned int hook_mask)
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{
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struct xt_connsecmark_target_info *info = targinfo;
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if (nf_ct_l3proto_try_module_get(target->family) < 0) {
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printk(KERN_WARNING "can't load conntrack support for "
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"proto=%d\n", target->family);
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return 0;
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}
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switch (info->mode) {
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case CONNSECMARK_SAVE:
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case CONNSECMARK_RESTORE:
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break;
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default:
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printk(KERN_INFO PFX "invalid mode: %hu\n", info->mode);
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return 0;
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}
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return 1;
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}
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static void
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destroy(const struct xt_target *target, void *targinfo)
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{
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nf_ct_l3proto_module_put(target->family);
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}
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static struct xt_target xt_connsecmark_target[] = {
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{
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.name = "CONNSECMARK",
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.family = AF_INET,
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.checkentry = checkentry,
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.destroy = destroy,
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.target = target,
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.targetsize = sizeof(struct xt_connsecmark_target_info),
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.table = "mangle",
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.me = THIS_MODULE,
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},
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{
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.name = "CONNSECMARK",
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.family = AF_INET6,
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.checkentry = checkentry,
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.destroy = destroy,
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.target = target,
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.targetsize = sizeof(struct xt_connsecmark_target_info),
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.table = "mangle",
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.me = THIS_MODULE,
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},
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};
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static int __init xt_connsecmark_init(void)
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{
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return xt_register_targets(xt_connsecmark_target,
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ARRAY_SIZE(xt_connsecmark_target));
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}
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static void __exit xt_connsecmark_fini(void)
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{
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xt_unregister_targets(xt_connsecmark_target,
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ARRAY_SIZE(xt_connsecmark_target));
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}
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module_init(xt_connsecmark_init);
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module_exit(xt_connsecmark_fini);
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