LXR linux/net/ipv6/ip6

   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