![David Miller](/assets/img/avatar_default.png)
On the output paths in particular, we have to sometimes deal with two socket contexts. First, and usually skb->sk, is the local socket that generated the frame. And second, is potentially the socket used to control a tunneling socket, such as one the encapsulates using UDP. We do not want to disassociate skb->sk when encapsulating in order to fix this, because that would break socket memory accounting. The most extreme case where this can cause huge problems is an AF_PACKET socket transmitting over a vxlan device. We hit code paths doing checks that assume they are dealing with an ipv4 socket, but are actually operating upon the AF_PACKET one. Signed-off-by: David S. Miller <davem@davemloft.net>
139 lines
3.3 KiB
C
139 lines
3.3 KiB
C
/* (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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* 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/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.h>
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#include <net/inet_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_l3proto.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 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 = NF_CT_DEFAULT_ZONE;
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#if IS_ENABLED(CONFIG_NF_CONNTRACK)
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if (skb->nfct)
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zone = nf_ct_zone((struct nf_conn *)skb->nfct);
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#endif
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#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
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if (skb->nf_bridge &&
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skb->nf_bridge->mask & BRNF_NF_BRIDGE_PREROUTING)
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return IP6_DEFRAG_CONNTRACK_BRIDGE_IN + zone;
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#endif
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if (hooknum == NF_INET_PRE_ROUTING)
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return IP6_DEFRAG_CONNTRACK_IN + zone;
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else
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return IP6_DEFRAG_CONNTRACK_OUT + zone;
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}
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static unsigned int ipv6_defrag(const struct nf_hook_ops *ops,
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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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struct sk_buff *reasm;
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#if IS_ENABLED(CONFIG_NF_CONNTRACK)
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/* Previously seen (loopback)? */
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if (skb->nfct && !nf_ct_is_template((struct nf_conn *)skb->nfct))
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return NF_ACCEPT;
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#endif
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reasm = nf_ct_frag6_gather(skb, nf_ct6_defrag_user(ops->hooknum, skb));
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/* queued */
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if (reasm == NULL)
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return NF_STOLEN;
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/* error occurred or not fragmented */
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if (reasm == skb)
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return NF_ACCEPT;
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nf_ct_frag6_consume_orig(reasm);
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NF_HOOK_THRESH(NFPROTO_IPV6, ops->hooknum, state->sk, reasm,
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state->in, state->out,
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state->okfn, NF_IP6_PRI_CONNTRACK_DEFRAG + 1);
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return NF_STOLEN;
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}
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static struct nf_hook_ops ipv6_defrag_ops[] = {
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{
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.hook = ipv6_defrag,
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.owner = THIS_MODULE,
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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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.owner = THIS_MODULE,
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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 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 = nf_register_hooks(ipv6_defrag_ops, ARRAY_SIZE(ipv6_defrag_ops));
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if (ret < 0) {
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pr_err("nf_defrag_ipv6: can't register hooks\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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nf_unregister_hooks(ipv6_defrag_ops, ARRAY_SIZE(ipv6_defrag_ops));
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nf_ct_frag6_cleanup();
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}
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void nf_defrag_ipv6_enable(void)
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{
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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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