[openwrt/openwrt] umbim: detect actual connection IP type

[LEDE Commits]

hauke pushed a commit to openwrt/openwrt.git, branch master:
https://git.openwrt.org/356a6f0eee93ffd03e8f398446ceded144c6237f

commit 356a6f0eee93ffd03e8f398446ceded144c6237f
Author: Lech Perczak <lech.perczak at gmail.com>
AuthorDate: Mon Feb 21 22:48:10 2022 +0100

    umbim: detect actual connection IP type
    
    Current implementation needlessly creates both IPv4 and IPv6
    sub-interfaces for single-stack IP types. Limit this only to selected IP
    type. While at that, ensure that IP type is also passed to umbim during
    "connect" phase. In addition, detect the actual established connection
    type returned by umbim and set up subinterfaces according to that,
    not to requested configuration. While at that, allow empty IP type explicitly,
    interpreted as "any" according to MBIM specification.
    
    Signed-off-by: Lech Perczak <lech.perczak at gmail.com>
---
 package/network/utils/umbim/files/lib/netifd/proto/mbim.sh | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/package/network/utils/umbim/files/lib/netifd/proto/mbim.sh b/package/network/utils/umbim/files/lib/netifd/proto/mbim.sh
index c6fa6665ef..c5f3663271 100755
--- a/package/network/utils/umbim/files/lib/netifd/proto/mbim.sh
+++ b/package/network/utils/umbim/files/lib/netifd/proto/mbim.sh
@@ -149,10 +149,13 @@ _proto_mbim_setup() {
 	tid=$((tid + 1))
 
 	pdptype=$(echo "$pdptype" | awk '{print tolower($0)}')
-	[ "$pdptype" = "ipv4" -o "$pdptype" = "ipv6" -o "$pdptype" = "ipv4v6" ] || pdptype="ipv4v6"
 
+	local req_pdptype="" # Pass "default" PDP type to umbim if unconfigured
+	[ "$pdptype" = "ipv4" -o "$pdptype" = "ipv6" -o "$pdptype" = "ipv4v6" ] && req_pdptype="$pdptype:"
+
+	local connect_state
 	echo "mbim[$$]" "Connect to network"
-	umbim $DBG -n -t $tid -d $device connect "$pdptype:$apn" "$auth" "$username" "$password" || {
+	connect_state=$(umbim $DBG -n -t $tid -d $device connect "$req_pdptype$apn" "$auth" "$username" "$password") || {
 		echo "mbim[$$]" "Failed to connect bearer"
 		tid=$((tid + 1))
 		umbim $DBG -t $tid -d "$device" disconnect
@@ -161,6 +164,9 @@ _proto_mbim_setup() {
 	}
 	tid=$((tid + 1))
 
+	echo "$connect_state"
+	local iptype="$(echo "$connect_state" | grep iptype: | awk '{print $4}')"
+
 	echo "mbim[$$]" "Connected"
 
 	if [ "$dhcp" = 0 ]; then
@@ -171,7 +177,7 @@ _proto_mbim_setup() {
 		proto_init_update "$ifname" 1
 		proto_send_update "$interface"
 
-		[ "$pdptype" = "ipv4" -o "$pdptype" = "ipv4v6" ] && {
+		[ "$iptype" != "ipv6" ] && {
 			json_init
 			json_add_string name "${interface}_4"
 			json_add_string ifname "@$interface"
@@ -188,7 +194,7 @@ _proto_mbim_setup() {
 			ubus call network add_dynamic "$(json_dump)"
 		}
 
-		[ "$pdptype" = "ipv6" -o "$pdptype" = "ipv4v6" ] && {
+		[ "$iptype" != "ipv4" ] && {
 			json_init
 			json_add_string name "${interface}_6"
 			json_add_string ifname "@$interface"