1// SPDX-License-Identifier: GPL-2.0
2#include <linux/export.h>
3#include <linux/icmpv6.h>
4#include <linux/mutex.h>
5#include <linux/netdevice.h>
6#include <linux/spinlock.h>
7
8#include <net/ipv6.h>
9
10#if IS_ENABLED(CONFIG_IPV6)
11
12#if !IS_BUILTIN(CONFIG_IPV6)
13
14static ip6_icmp_send_t __rcu *ip6_icmp_send;
15
16int inet6_register_icmp_sender(ip6_icmp_send_t *fn)
17{
18	return (cmpxchg((ip6_icmp_send_t **)&ip6_icmp_send, NULL, fn) == NULL) ?
19		0 : -EBUSY;
20}
21EXPORT_SYMBOL(inet6_register_icmp_sender);
22
23int inet6_unregister_icmp_sender(ip6_icmp_send_t *fn)
24{
25	int ret;
26
27	ret = (cmpxchg((ip6_icmp_send_t **)&ip6_icmp_send, fn, NULL) == fn) ?
28	      0 : -EINVAL;
29
30	synchronize_net();
31
32	return ret;
33}
34EXPORT_SYMBOL(inet6_unregister_icmp_sender);
35
36void __icmpv6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info,
37		   const struct inet6_skb_parm *parm)
38{
39	ip6_icmp_send_t *send;
40
41	rcu_read_lock();
42	send = rcu_dereference(ip6_icmp_send);
43	if (send)
44		send(skb, type, code, info, NULL, parm);
45	rcu_read_unlock();
46}
47EXPORT_SYMBOL(__icmpv6_send);
48#endif
49
50#if IS_ENABLED(CONFIG_NF_NAT)
51#include <net/netfilter/nf_conntrack.h>
52void icmpv6_ndo_send(struct sk_buff *skb_in, u8 type, u8 code, __u32 info)
53{
54	struct inet6_skb_parm parm = { 0 };
55	struct sk_buff *cloned_skb = NULL;
56	enum ip_conntrack_info ctinfo;
57	struct in6_addr orig_ip;
58	struct nf_conn *ct;
59
60	ct = nf_ct_get(skb_in, &ctinfo);
61	if (!ct || !(ct->status & IPS_SRC_NAT)) {
62		__icmpv6_send(skb_in, type, code, info, &parm);
63		return;
64	}
65
66	if (skb_shared(skb_in))
67		skb_in = cloned_skb = skb_clone(skb_in, GFP_ATOMIC);
68
69	if (unlikely(!skb_in || skb_network_header(skb_in) < skb_in->head ||
70	    (skb_network_header(skb_in) + sizeof(struct ipv6hdr)) >
71	    skb_tail_pointer(skb_in) || skb_ensure_writable(skb_in,
72	    skb_network_offset(skb_in) + sizeof(struct ipv6hdr))))
73		goto out;
74
75	orig_ip = ipv6_hdr(skb_in)->saddr;
76	ipv6_hdr(skb_in)->saddr = ct->tuplehash[0].tuple.src.u3.in6;
77	__icmpv6_send(skb_in, type, code, info, &parm);
78	ipv6_hdr(skb_in)->saddr = orig_ip;
79out:
80	consume_skb(cloned_skb);
81}
82EXPORT_SYMBOL(icmpv6_ndo_send);
83#endif
84#endif
85