ecb2421b5d
currently aliased to try_module_get/_put. Will be changed in next patch when we add functions to make use of ->net argument to store usercount per l3proto tracker. This is needed to avoid registering the conntrack hooks in all netns and later only enable connection tracking in those that need conntrack. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
144 lines
3.6 KiB
C
144 lines
3.6 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) 2006,2008 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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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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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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#include <net/netfilter/nf_conntrack_ecache.h>
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("James Morris <jmorris@redhat.com>");
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MODULE_DESCRIPTION("Xtables: target for copying between connection and security mark");
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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(const 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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nf_conntrack_event_cache(IPCT_SECMARK, ct);
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}
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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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const 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
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connsecmark_tg(struct sk_buff *skb, const struct xt_action_param *par)
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{
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const struct xt_connsecmark_target_info *info = par->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 connsecmark_tg_check(const struct xt_tgchk_param *par)
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{
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const struct xt_connsecmark_target_info *info = par->targinfo;
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int ret;
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if (strcmp(par->table, "mangle") != 0 &&
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strcmp(par->table, "security") != 0) {
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pr_info("target only valid in the \'mangle\' "
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"or \'security\' tables, not \'%s\'.\n", par->table);
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return -EINVAL;
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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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pr_info("invalid mode: %hu\n", info->mode);
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return -EINVAL;
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}
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ret = nf_ct_netns_get(par->net, par->family);
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if (ret < 0)
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pr_info("cannot load conntrack support for proto=%u\n",
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par->family);
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return ret;
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}
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static void connsecmark_tg_destroy(const struct xt_tgdtor_param *par)
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{
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nf_ct_netns_put(par->net, par->family);
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}
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static struct xt_target connsecmark_tg_reg __read_mostly = {
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.name = "CONNSECMARK",
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.revision = 0,
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.family = NFPROTO_UNSPEC,
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.checkentry = connsecmark_tg_check,
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.destroy = connsecmark_tg_destroy,
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.target = connsecmark_tg,
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.targetsize = sizeof(struct xt_connsecmark_target_info),
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.me = THIS_MODULE,
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};
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static int __init connsecmark_tg_init(void)
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{
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return xt_register_target(&connsecmark_tg_reg);
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}
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static void __exit connsecmark_tg_exit(void)
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{
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xt_unregister_target(&connsecmark_tg_reg);
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}
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module_init(connsecmark_tg_init);
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module_exit(connsecmark_tg_exit);
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