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 
14 static ip6_icmp_send_t __rcu *ip6_icmp_send;
15 
inet6_register_icmp_sender(ip6_icmp_send_t * fn)16 int 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 }
21 EXPORT_SYMBOL(inet6_register_icmp_sender);
22 
inet6_unregister_icmp_sender(ip6_icmp_send_t * fn)23 int 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 }
34 EXPORT_SYMBOL(inet6_unregister_icmp_sender);
35 
__icmpv6_send(struct sk_buff * skb,u8 type,u8 code,__u32 info,const struct inet6_skb_parm * parm)36 void __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 }
47 EXPORT_SYMBOL(__icmpv6_send);
48 #endif
49 
50 #if IS_ENABLED(CONFIG_NF_NAT)
51 #include <net/netfilter/nf_conntrack.h>
icmpv6_ndo_send(struct sk_buff * skb_in,u8 type,u8 code,__u32 info)52 void 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;
79 out:
80 	consume_skb(cloned_skb);
81 }
82 EXPORT_SYMBOL(icmpv6_ndo_send);
83 #endif
84 #endif
85