net/ipv4/route.c

2558 				       struct net_device *dev_out,
2568 	in_dev = __in_dev_get_rcu(dev_out);
2574 		    !(dev_out->flags & IFF_LOOPBACK) &&
2575 		    !netif_is_l3_master(dev_out))
2585 	if (dev_out->flags & IFF_LOOPBACK)
2605 		   (orig_oif != dev_out->ifindex)) {
2645 	rth = rt_dst_alloc(dev_out, flags, type,
2656 		    !(dev_out->flags & IFF_LOOPBACK)) {
2707 	struct net_device *dev_out = NULL;
2722 		/* I removed check for oif == dev_out->oif here.
2734 			dev_out = __ip_dev_find(net, fl4->saddr, false);
2735 			if (!dev_out)
2753 			fl4->flowi4_oif = dev_out->ifindex;
2766 		dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif);
2768 		if (!dev_out)
2772 		if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) {
2780 				fl4->saddr = inet_select_addr(dev_out, 0,
2786 				fl4->saddr = inet_select_addr(dev_out, 0,
2789 				fl4->saddr = inet_select_addr(dev_out, 0,
2798 		dev_out = net->loopback_dev;
2830 				fl4->saddr = inet_select_addr(dev_out, 0,
2848 		dev_out = l3mdev_master_dev_rcu(FIB_RES_DEV(*res)) ? :
2856 		fl4->flowi4_oif = dev_out->ifindex;
2863 	dev_out = FIB_RES_DEV(*res);
2866 	rth = __mkroute_output(res, fl4, orig_oif, dev_out, flags);