ipv6: make IPV6_RECVPKTINFO work for ipv4 datagrams
We currently don't report IPV6_RECVPKTINFO in cmsg access ancillary data
for IPv4 datagrams on IPv6 sockets.
This patch splits the ip6_datagram_recv_ctl into two functions, one
which handles both protocol families, AF_INET and AF_INET6, while the
ip6_datagram_recv_specific_ctl only handles IPv6 cmsg data.
ip6_datagram_recv_*_ctl never reported back any errors, so we can make
them return void. Also provide a helper for protocols which don't offer dual
personality to further use ip6_datagram_recv_ctl, which is exported to
modules.
I needed to shuffle the code for ping around a bit to make it easier to
implement dual personality for ping ipv6 sockets in future.
Reported-by: Gert Doering <gert@space.net>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index 22f15eb..580dd96 100644
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -56,7 +56,6 @@
/*
* SOL_IP control messages.
*/
-#define PKTINFO_SKB_CB(__skb) ((struct in_pktinfo *)((__skb)->cb))
static void ip_cmsg_recv_pktinfo(struct msghdr *msg, struct sk_buff *skb)
{
@@ -1055,9 +1054,10 @@
void ipv4_pktinfo_prepare(const struct sock *sk, struct sk_buff *skb)
{
struct in_pktinfo *pktinfo = PKTINFO_SKB_CB(skb);
+ bool prepare = (inet_sk(sk)->cmsg_flags & IP_CMSG_PKTINFO) ||
+ ipv6_sk_rxinfo(sk);
- if ((inet_sk(sk)->cmsg_flags & IP_CMSG_PKTINFO) &&
- skb_rtable(skb)) {
+ if (prepare && skb_rtable(skb)) {
pktinfo->ipi_ifindex = inet_iif(skb);
pktinfo->ipi_spec_dst.s_addr = fib_compute_spec_dst(skb);
} else {