uqmi: always use DHCP for IPv4

Commit 8f24ee6382 ("uqmi: Add proper IPv6 support") changed the code
to fetch the IPv4 address via QMI by default instead of using DHCP to
make it consistent with the IPv6 codepath.
This breaks on at least some Sierra Wireless cards, where data exchanges
fail to work until the host has fetched a DHCP lease.
Leave v6 as it is, but always use DHCP for v4.

Signed-off-by: Felix Fietkau <nbd@nbd.name>

package/network/utils/uqmi/files/lib/netifd/proto/qmi.sh

@@ -139,27 +139,20 @@ proto_qmi_setup() {
 		return 1
 	}
 
-	if [ -z "$dhcp" -o "$dhcp" = 0 ]; then
 	echo "Setting up $ifname"
-		[ -n "$ipv4" ] && {
-			json_load "$(uqmi -s -d $device --set-client-id wds,$cid_4 --get-current-settings)"
-			json_select ipv4
-			json_get_vars ip subnet gateway dns1 dns2
-
 	proto_init_update "$ifname" 1
-			proto_set_keep 1
-			proto_add_ipv4_address "$ip" "$subnet"
-			proto_add_dns_server "$dns1"
-			proto_add_dns_server "$dns2"
-			proto_add_ipv4_route "0.0.0.0" 0 "$gateway"
 	proto_add_data
+	[ -n "$ipv4" ] && {
 		json_add_string "cid_4" "$cid_4"
 		json_add_string "pdh_4" "$pdh_4"
-			proto_close_data
-			proto_send_update "$interface"
+	}
+	[ -n "$ipv6" ] && {
+		json_add_string "cid_6" "$cid_6"
+		json_add_string "pdh_6" "$pdh_6"
 	}
 
 	[ -n "$ipv6" ] && {
+		if [ -z "$dhcp" -o "$dhcp" = 0 ]; then
 			json_load "$(uqmi -s -d $device --set-client-id wds,$cid_6 --get-current-settings)"
 			json_select ipv6
 			json_get_var ip_6 ip
@@ -168,8 +161,6 @@ proto_qmi_setup() {
 			json_get_var dns2_6 dns2
 			json_get_var ip_prefix_length ip-prefix-length
 
-			proto_init_update "$ifname" 1
-			proto_set_keep 1
 			# RFC 7278: Extend an IPv6 /64 Prefix to LAN
 			proto_add_ipv6_address "$ip_6" "128"
 			proto_add_ipv6_prefix "${ip_6}/${ip_prefix_length}"
@@ -180,46 +171,31 @@ proto_qmi_setup() {
 			proto_add_data
 			json_add_string "cid_6" "$cid_6"
 			json_add_string "pdh_6" "$pdh_6"
-			proto_close_data
-			proto_send_update "$interface"
-		}
 		else
-		echo "Starting DHCP on $ifname"
-		proto_init_update "$ifname" 1
-		proto_add_data
-		[ -n "$ipv4" ] && {
-			json_add_string "cid_4" "$cid_4"
-			json_add_string "pdh_4" "$pdh_4"
-		}
-		[ -n "$ipv6" ] && {
-			json_add_string "cid_6" "$cid_6"
-			json_add_string "pdh_6" "$pdh_6"
-		}
-		proto_close_data
-		proto_send_update "$interface"
-
-		[ -n "$ipv4" ] && {
 			json_init
-			json_add_string name "${interface}_4"
+			json_add_string name "${interface}_6"
 			json_add_string ifname "@$interface"
-			json_add_string proto "dhcp"
+			json_add_string proto "dhcpv6"
 			json_add_int metric "$metric"
+			# RFC 7278: Extend an IPv6 /64 Prefix to LAN
+			json_add_string extendprefix 1
 			json_close_object
 			ubus call network add_dynamic "$(json_dump)"
+		fi
 	}
 
-		[ -n "$ipv6" ] && {
+	proto_close_data
+	proto_send_update "$interface"
+
+	[ -n "$ipv4" ] && {
 		json_init
-			json_add_string name "${interface}_6"
+		json_add_string name "${interface}_4"
 		json_add_string ifname "@$interface"
-			json_add_string proto "dhcpv6"
+		json_add_string proto "dhcp"
 		json_add_int metric "$metric"
-			# RFC 7278: Extend an IPv6 /64 Prefix to LAN
-			json_add_string extendprefix 1
 		json_close_object
 		ubus call network add_dynamic "$(json_dump)"
 	}
-	fi
 }
 
 proto_qmi_teardown() {