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Diffstat (limited to 'net/ipv6/ip6_output.c')
-rw-r--r--net/ipv6/ip6_output.c39
1 files changed, 31 insertions, 8 deletions
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index 7fde1f265c90..c21777565c58 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -886,22 +886,45 @@ static int ip6_dst_lookup_tail(struct sock *sk,
#endif
int err;
- if (!*dst)
- *dst = ip6_route_output(net, sk, fl6);
-
- err = (*dst)->error;
- if (err)
- goto out_err_release;
+ /* The correct way to handle this would be to do
+ * ip6_route_get_saddr, and then ip6_route_output; however,
+ * the route-specific preferred source forces the
+ * ip6_route_output call _before_ ip6_route_get_saddr.
+ *
+ * In source specific routing (no src=any default route),
+ * ip6_route_output will fail given src=any saddr, though, so
+ * that's why we try it again later.
+ */
+ if (ipv6_addr_any(&fl6->saddr) && (!*dst || !(*dst)->error)) {
+ struct rt6_info *rt;
+ bool had_dst = *dst != NULL;
- if (ipv6_addr_any(&fl6->saddr)) {
- struct rt6_info *rt = (struct rt6_info *) *dst;
+ if (!had_dst)
+ *dst = ip6_route_output(net, sk, fl6);
+ rt = (*dst)->error ? NULL : (struct rt6_info *)*dst;
err = ip6_route_get_saddr(net, rt, &fl6->daddr,
sk ? inet6_sk(sk)->srcprefs : 0,
&fl6->saddr);
if (err)
goto out_err_release;
+
+ /* If we had an erroneous initial result, pretend it
+ * never existed and let the SA-enabled version take
+ * over.
+ */
+ if (!had_dst && (*dst)->error) {
+ dst_release(*dst);
+ *dst = NULL;
+ }
}
+ if (!*dst)
+ *dst = ip6_route_output(net, sk, fl6);
+
+ err = (*dst)->error;
+ if (err)
+ goto out_err_release;
+
#ifdef CONFIG_IPV6_OPTIMISTIC_DAD
/*
* Here if the dst entry we've looked up