net: bootp: Fall back to BOOTP from DHCP when unit testing

If we sent a DHCP packet and get a BOOTP response from the server, we
shouldn't try to send a DHCPREQUEST packet, since it won't be DHCPACKed.
Transition straight to BIND. This is only enabled for UNIT_TEST to avoid
bloat, since I suspect the number of BOOTP servers in the wild is
vanishingly small.

Signed-off-by: Sean Anderson <seanga2@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/net/bootp.c b/net/bootp.c
index 2053cce..7b0f45e 100644
--- a/net/bootp.c
+++ b/net/bootp.c
@@ -1073,6 +1073,11 @@
 			    CONFIG_SYS_BOOTFILE_PREFIX,
 			    strlen(CONFIG_SYS_BOOTFILE_PREFIX)) == 0) {
 #endif	/* CONFIG_SYS_BOOTFILE_PREFIX */
+			if (CONFIG_IS_ENABLED(UNIT_TEST) &&
+			    dhcp_message_type((u8 *)bp->bp_vend) == -1) {
+				debug("got BOOTP response; transitioning to BOUND\n");
+				goto dhcp_got_bootp;
+			}
 			dhcp_packet_process_options(bp);
 			if (CONFIG_IS_ENABLED(EFI_LOADER) &&
 			    IS_ENABLED(CONFIG_NETDEVICES))
@@ -1099,6 +1104,7 @@
 		debug("DHCP State: REQUESTING\n");
 
 		if (dhcp_message_type((u8 *)bp->bp_vend) == DHCP_ACK) {
+dhcp_got_bootp:
 			dhcp_packet_process_options(bp);
 			/* Store net params from reply */
 			store_net_params(bp);