kernel-netlink: Use RTA_SRC to specify route source in kernel-based lookups

For table dumps the kernel accepts RTA_PREFSRC to filter the routes, which is
what we do when doing userspace route calculations. For kernel-based route
lookups, however, the RTA_PREFSRC attribute is ignored and we must specify
RTA_SRC for policy based route lookups.

diff --git a/src/libcharon/plugins/kernel_netlink/kernel_netlink_net.c b/src/libcharon/plugins/kernel_netlink/kernel_netlink_net.c
index 3306956..2dc76d9 100644 (file)
--- a/src/libcharon/plugins/kernel_netlink/kernel_netlink_net.c
+++ b/src/libcharon/plugins/kernel_netlink/kernel_netlink_net.c
@@ -1883,7 +1883,14 @@ static host_t *get_route(private_kernel_netlink_net_t *this, host_t *dest,
        if (candidate)
        {
                chunk = candidate->get_address(candidate);
-               netlink_add_attribute(hdr, RTA_PREFSRC, chunk, sizeof(request));
+               if (hdr->nlmsg_flags & NLM_F_DUMP)
+               {
+                       netlink_add_attribute(hdr, RTA_PREFSRC, chunk, sizeof(request));
+               }
+               else
+               {
+                       netlink_add_attribute(hdr, RTA_SRC, chunk, sizeof(request));
+               }
        }
        /* we use this below to match against the routes */
        chunk = dest->get_address(dest);