From 438a2f37dfec389d928fbfd09ab9c0974dd6942b Mon Sep 17 00:00:00 2001
From: Govindaraja N B <gnb.ext@libertyglobal.com>
Date: Thu, 18 Dec 2025 14:42:46 +0530
Subject: [PATCH] RDKBNETWOR-84: DSLite feature integration with WanManager (Wg
 network11 development)

*  RDKBNETWOR-91: Passing correct dhcp options when dslite mode is enabled

- Added DNS handling support for DS-Lite mode.
- brlan0 bridge IP is provided as DNS server option for LAN clients.

Signed-off-by: Govindaraja N B <gnb.ext@libertyglobal.com>
---
 .../dhcp_server_functions.sh                  | 15 +++++++++++-
 source/service_dhcp/dhcp_server_functions.c   | 23 +++++++++++++++++--
 2 files changed, 35 insertions(+), 3 deletions(-)

diff --git a/source/scripts/init/service.d/service_dhcp_server/dhcp_server_functions.sh b/source/scripts/init/service.d/service_dhcp_server/dhcp_server_functions.sh
index a0548fb6..1fbdbe4c 100755
--- a/source/scripts/init/service.d/service_dhcp_server/dhcp_server_functions.sh
+++ b/source/scripts/init/service.d/service_dhcp_server/dhcp_server_functions.sh
@@ -1124,8 +1124,21 @@ fi
       #prepare_dhcp_options
 	  prepare_dhcp_options_wan_dns	
    fi
+
+   if [ "$FIRMWARE_TYPE" != "OFW" ]; then
+      DSLITE_ENABLE=$(syscfg get dslite_enable)
+
+      # DS-Lite: use brlan0 bridge IP as DNS
+      if [ "$DSLITE_ENABLE" = "1" ]; then
+         LAN_IP=$(syscfg get lan_ipaddr)
+
+         if [ -n "$LAN_IP" ]; then
+            echo "option:dns-server,$LAN_IP" >> "$DHCP_OPTIONS_FILE"
+         fi
+      fi
+   fi
    
-   if [ "$BOX_TYPE" != "HUB4" ] && [ "$BOX_TYPE" != "SR300" ] && [ "$BOX_TYPE" != "SE501" ] && [ "$BOX_TYPE" != "SR213" ] && [ "$SelfHealSupport" != "true" ]; then
+   if [[ "$FIRMWARE_TYPE" != "OFW" && "$DSLITE_ENABLE" != "1" ]] && [ "$BOX_TYPE" != "HUB4" ] && [ "$BOX_TYPE" != "SR300" ] && [ "$BOX_TYPE" != "SE501" ] && [ "$BOX_TYPE" != "SR213" ] && [ "$SelfHealSupport" != "true" ]; then
       nameserver=`grep "nameserver" $RESOLV_CONF | awk '{print $2}'|grep -v ":"|tr '\n' ','| sed -e 's/,$//'`
       if [ -n "$nameserver" ]; then
          echo "option:dns-server,$nameserver" >> $DHCP_OPTIONS_FILE
diff --git a/source/service_dhcp/dhcp_server_functions.c b/source/service_dhcp/dhcp_server_functions.c
index df3adb37..6ce5567e 100644
--- a/source/service_dhcp/dhcp_server_functions.c
+++ b/source/service_dhcp/dhcp_server_functions.c
@@ -1606,8 +1606,27 @@ int prepare_dhcp_conf (char *input)
 		prepare_dhcp_options_wan_dns();
 	}
   
-#if defined (_XB6_PRODUCT_REQ_) || defined (_CBR_PRODUCT_REQ_)
+#if !defined _LG_OFW_
+    char dslite_enable[8] = {0};
+    if (syscfg_get(NULL, "dslite_enable", dslite_enable, sizeof(dslite_enable)) == 0 && !strcmp(dslite_enable, "1"))
     {
+        FILE *fp = fopen(DHCP_OPTIONS_FILE, "a");
+        if (fp)
+        {
+            char lan_ip[32] = {0};
+
+            if (!syscfg_get(NULL, "lan_ipaddr", lan_ip, sizeof(lan_ip)) &&
+                lan_ip[0] != '\0')
+            {
+                fprintf(fp, "option:dns-server,%s\n", lan_ip);
+            }
+            fclose(fp);
+        }
+    }
+    else
+#endif /* _LG_OFW_ */
+    {
+#if defined (_XB6_PRODUCT_REQ_) || defined (_CBR_PRODUCT_REQ_)
         struct in_addr ipv4Addr;
         int    ret = -1;
         int    resComp = -1;
@@ -1656,8 +1675,8 @@ int prepare_dhcp_conf (char *input)
         {
             fprintf(g_fArmConsoleLog, "DHCP_SERVER : Error in opening %s\n",RESOLV_CONF );
         }
-    }
 #endif
+    }
   
    	sysevent_get(g_iSyseventfd, g_tSysevent_token, "lan-status", l_cLan_Status, sizeof(l_cLan_Status));
 	if (!strncmp(l_cLan_Status, "started", 7))