[source] uqmi: always use DHCP for IPv4

[LEDE Commits]

nbd pushed a commit to source.git, branch master:
https://git.lede-project.org/3b9b963e6e08eedcf4abff60998027018ab73ecd

commit 3b9b963e6e08eedcf4abff60998027018ab73ecd
Author: Felix Fietkau <nbd at nbd.name>
AuthorDate: Wed Sep 14 16:06:41 2016 +0200

    uqmi: always use DHCP for IPv4
    
    Commit 8f24ee638275 ("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 at nbd.name>
---
 .../utils/uqmi/files/lib/netifd/proto/qmi.sh       | 84 ++++++++--------------
 1 file changed, 30 insertions(+), 54 deletions(-)

diff --git a/package/network/utils/uqmi/files/lib/netifd/proto/qmi.sh b/package/network/utils/uqmi/files/lib/netifd/proto/qmi.sh
index 32df6ee..81c1c35 100755
--- a/package/network/utils/uqmi/files/lib/netifd/proto/qmi.sh
+++ b/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
-			json_add_string "cid_4" "$cid_4"
-			json_add_string "pdh_4" "$pdh_4"
-			proto_close_data
-			proto_send_update "$interface"
-		}
-	
-		[ -n "$ipv6" ] && {
+	echo "Setting up $ifname"
+	proto_init_update "$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"
+	}
+
+	[ -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}"
@@ -180,35 +171,7 @@ 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 "${interface}_4"
-			json_add_string ifname "@$interface"
-			json_add_string proto "dhcp"
-			json_add_int metric "$metric"
-			json_close_object
-			ubus call network add_dynamic "$(json_dump)"
-		}
-
-		[ -n "$ipv6" ] && {
+		else
 			json_init
 			json_add_string name "${interface}_6"
 			json_add_string ifname "@$interface"
@@ -218,8 +181,21 @@ proto_qmi_setup() {
 			json_add_string extendprefix 1
 			json_close_object
 			ubus call network add_dynamic "$(json_dump)"
-		}
-	fi
+		fi
+	}
+
+	proto_close_data
+	proto_send_update "$interface"
+
+	[ -n "$ipv4" ] && {
+		json_init
+		json_add_string name "${interface}_4"
+		json_add_string ifname "@$interface"
+		json_add_string proto "dhcp"
+		json_add_int metric "$metric"
+		json_close_object
+		ubus call network add_dynamic "$(json_dump)"
+	}
 }
 
 proto_qmi_teardown() {