// SPDX-License-Identifier: GPL-2.0-only
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/* (C) 1999-2001 Paul `Rusty' Russell
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* (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
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*/
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#include <linux/types.h>
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#include <linux/ipv6.h>
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#include <linux/in6.h>
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#include <linux/netfilter.h>
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#include <linux/module.h>
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#include <linux/skbuff.h>
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#include <linux/icmp.h>
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#include <linux/sysctl.h>
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#include <net/ipv6_frag.h>
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#include <linux/netfilter_ipv6.h>
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#include <linux/netfilter_bridge.h>
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#if IS_ENABLED(CONFIG_NF_CONNTRACK)
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#include <net/netfilter/nf_conntrack.h>
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#include <net/netfilter/nf_conntrack_helper.h>
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#include <net/netfilter/nf_conntrack_l4proto.h>
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#include <net/netfilter/nf_conntrack_core.h>
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#include <net/netfilter/ipv6/nf_conntrack_ipv6.h>
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#endif
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#include <net/netfilter/nf_conntrack_zones.h>
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#include <net/netfilter/ipv6/nf_defrag_ipv6.h>
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static DEFINE_MUTEX(defrag6_mutex);
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static enum ip6_defrag_users nf_ct6_defrag_user(unsigned int hooknum,
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struct sk_buff *skb)
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{
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u16 zone_id = NF_CT_DEFAULT_ZONE_ID;
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#if IS_ENABLED(CONFIG_NF_CONNTRACK)
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if (skb_nfct(skb)) {
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enum ip_conntrack_info ctinfo;
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const struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
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zone_id = nf_ct_zone_id(nf_ct_zone(ct), CTINFO2DIR(ctinfo));
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}
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#endif
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if (nf_bridge_in_prerouting(skb))
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return IP6_DEFRAG_CONNTRACK_BRIDGE_IN + zone_id;
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if (hooknum == NF_INET_PRE_ROUTING)
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return IP6_DEFRAG_CONNTRACK_IN + zone_id;
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else
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return IP6_DEFRAG_CONNTRACK_OUT + zone_id;
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}
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static unsigned int ipv6_defrag(void *priv,
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struct sk_buff *skb,
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const struct nf_hook_state *state)
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{
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int err;
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#if IS_ENABLED(CONFIG_NF_CONNTRACK)
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/* Previously seen (loopback)? */
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if (skb_nfct(skb) && !nf_ct_is_template((struct nf_conn *)skb_nfct(skb)))
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return NF_ACCEPT;
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if (skb->_nfct == IP_CT_UNTRACKED)
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return NF_ACCEPT;
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#endif
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err = nf_ct_frag6_gather(state->net, skb,
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nf_ct6_defrag_user(state->hook, skb));
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/* queued */
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if (err == -EINPROGRESS)
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return NF_STOLEN;
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return err == 0 ? NF_ACCEPT : NF_DROP;
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}
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static const struct nf_hook_ops ipv6_defrag_ops[] = {
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{
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.hook = ipv6_defrag,
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.pf = NFPROTO_IPV6,
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.hooknum = NF_INET_PRE_ROUTING,
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.priority = NF_IP6_PRI_CONNTRACK_DEFRAG,
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},
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{
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.hook = ipv6_defrag,
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.pf = NFPROTO_IPV6,
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.hooknum = NF_INET_LOCAL_OUT,
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.priority = NF_IP6_PRI_CONNTRACK_DEFRAG,
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},
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};
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static void __net_exit defrag6_net_exit(struct net *net)
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{
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if (net->nf.defrag_ipv6) {
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nf_unregister_net_hooks(net, ipv6_defrag_ops,
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ARRAY_SIZE(ipv6_defrag_ops));
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net->nf.defrag_ipv6 = false;
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}
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}
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static struct pernet_operations defrag6_net_ops = {
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.exit = defrag6_net_exit,
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};
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static int __init nf_defrag_init(void)
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{
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int ret = 0;
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ret = nf_ct_frag6_init();
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if (ret < 0) {
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pr_err("nf_defrag_ipv6: can't initialize frag6.\n");
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return ret;
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}
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ret = register_pernet_subsys(&defrag6_net_ops);
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if (ret < 0) {
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pr_err("nf_defrag_ipv6: can't register pernet ops\n");
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goto cleanup_frag6;
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}
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return ret;
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cleanup_frag6:
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nf_ct_frag6_cleanup();
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return ret;
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}
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static void __exit nf_defrag_fini(void)
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{
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unregister_pernet_subsys(&defrag6_net_ops);
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nf_ct_frag6_cleanup();
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}
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int nf_defrag_ipv6_enable(struct net *net)
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{
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int err = 0;
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might_sleep();
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if (net->nf.defrag_ipv6)
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return 0;
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mutex_lock(&defrag6_mutex);
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if (net->nf.defrag_ipv6)
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goto out_unlock;
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err = nf_register_net_hooks(net, ipv6_defrag_ops,
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ARRAY_SIZE(ipv6_defrag_ops));
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if (err == 0)
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net->nf.defrag_ipv6 = true;
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out_unlock:
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mutex_unlock(&defrag6_mutex);
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return err;
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}
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EXPORT_SYMBOL_GPL(nf_defrag_ipv6_enable);
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module_init(nf_defrag_init);
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module_exit(nf_defrag_fini);
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MODULE_LICENSE("GPL");
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