net/ipv6/ip6_icmp.c

   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
  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
  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
  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>
  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