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authorJason A. Donenfeld <Jason@zx2c4.com>2020-02-11 20:47:05 +0100
committerDavid S. Miller <davem@davemloft.net>2020-02-13 14:19:00 -0800
commit0b41713b606694257b90d61ba7e2712d8457648b (patch)
tree9d2df288a3386102321124f7442d304b7f4fa28e /net/ipv6
parent07134cf6962377875288b06232d0c41c69d31752 (diff)
icmp: introduce helper for nat'd source address in network device context
This introduces a helper function to be called only by network drivers that wraps calls to icmp[v6]_send in a conntrack transformation, in case NAT has been used. We don't want to pollute the non-driver path, though, so we introduce this as a helper to be called by places that actually make use of this, as suggested by Florian. Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Cc: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv6')
-rw-r--r--net/ipv6/ip6_icmp.c34
1 files changed, 34 insertions, 0 deletions
diff --git a/net/ipv6/ip6_icmp.c b/net/ipv6/ip6_icmp.c
index 02045494c24c..e0086758b6ee 100644
--- a/net/ipv6/ip6_icmp.c
+++ b/net/ipv6/ip6_icmp.c
@@ -45,4 +45,38 @@ out:
rcu_read_unlock();
}
EXPORT_SYMBOL(icmpv6_send);
+
+#if IS_ENABLED(CONFIG_NF_NAT)
+#include <net/netfilter/nf_conntrack.h>
+void icmpv6_ndo_send(struct sk_buff *skb_in, u8 type, u8 code, __u32 info)
+{
+ struct sk_buff *cloned_skb = NULL;
+ enum ip_conntrack_info ctinfo;
+ struct in6_addr orig_ip;
+ struct nf_conn *ct;
+
+ ct = nf_ct_get(skb_in, &ctinfo);
+ if (!ct || !(ct->status & IPS_SRC_NAT)) {
+ icmpv6_send(skb_in, type, code, info);
+ return;
+ }
+
+ if (skb_shared(skb_in))
+ skb_in = cloned_skb = skb_clone(skb_in, GFP_ATOMIC);
+
+ if (unlikely(!skb_in || skb_network_header(skb_in) < skb_in->head ||
+ (skb_network_header(skb_in) + sizeof(struct ipv6hdr)) >
+ skb_tail_pointer(skb_in) || skb_ensure_writable(skb_in,
+ skb_network_offset(skb_in) + sizeof(struct ipv6hdr))))
+ goto out;
+
+ orig_ip = ipv6_hdr(skb_in)->saddr;
+ ipv6_hdr(skb_in)->saddr = ct->tuplehash[0].tuple.src.u3.in6;
+ icmpv6_send(skb_in, type, code, info);
+ ipv6_hdr(skb_in)->saddr = orig_ip;
+out:
+ consume_skb(cloned_skb);
+}
+EXPORT_SYMBOL(icmpv6_ndo_send);
+#endif
#endif