freifunkist-firmware/package/utils/busybox/patches/204-udhcpc_src_ip_rebind.patch

--- a/networking/udhcp/dhcpc.c
+++ b/networking/udhcp/dhcpc.c
@@ -663,10 +663,10 @@ static void add_client_options(struct dh
  * client reverts to using the IP broadcast address.
  */
 
-static int raw_bcast_from_client_config_ifindex(struct dhcp_packet *packet)
+static int raw_bcast_from_client_config_ifindex(struct dhcp_packet *packet, uint32_t src_nip)
 {
 	return udhcp_send_raw_packet(packet,
-		/*src*/ INADDR_ANY, CLIENT_PORT,
+		/*src*/ src_nip, CLIENT_PORT,
 		/*dst*/ INADDR_BROADCAST, SERVER_PORT, MAC_BCAST_ADDR,
 		client_config.ifindex);
 }
@@ -677,7 +677,7 @@ static int bcast_or_ucast(struct dhcp_pa
 		return udhcp_send_kernel_packet(packet,
 			ciaddr, CLIENT_PORT,
 			server, SERVER_PORT);
-	return raw_bcast_from_client_config_ifindex(packet);
+	return raw_bcast_from_client_config_ifindex(packet, ciaddr);
 }
 
 /* Broadcast a DHCP discover packet to the network, with an optionally requested IP */
@@ -705,7 +705,7 @@ static NOINLINE int send_discover(uint32
 
 	if (msgs++ < 3)
 	bb_info_msg("Sending discover...");
-	return raw_bcast_from_client_config_ifindex(&packet);
+	return raw_bcast_from_client_config_ifindex(&packet, INADDR_ANY);
 }
 
 /* Broadcast a DHCP request message */
@@ -749,7 +749,7 @@ static NOINLINE int send_select(uint32_t
 
 	addr.s_addr = requested;
 	bb_info_msg("Sending select for %s...", inet_ntoa(addr));
-	return raw_bcast_from_client_config_ifindex(&packet);
+	return raw_bcast_from_client_config_ifindex(&packet, INADDR_ANY);
 }
 
 /* Unicast or broadcast a DHCP renew message */
@@ -817,7 +817,7 @@ static NOINLINE int send_decline(/*uint3
 	udhcp_add_simple_option(&packet, DHCP_SERVER_ID, server);
 
 	bb_info_msg("Sending decline...");
-	return raw_bcast_from_client_config_ifindex(&packet);
+	return raw_bcast_from_client_config_ifindex(&packet, INADDR_ANY);
 }
 #endif