Accepting request 1294750 from Virtualization

- fcopy: Fix irregularities with size of ring buffer (a4131a50)
- fcopy: Fix incorrect file path conversion (0d86a8d6)

OBS-URL: https://build.opensuse.org/request/show/1294750
OBS-URL: https://build.opensuse.org/package/show/openSUSE:Factory/hyper-v?expand=0&rev=49

hyper-v.changes

@@ -1,3 +1,27 @@
+-------------------------------------------------------------------
+Sun Jul 20 20:20:20 UTC 2025 - ohering@suse.de
+
+- fcopy: Fix irregularities with size of ring buffer (a4131a50)
+- fcopy: Fix incorrect file path conversion (0d86a8d6)
+
+-------------------------------------------------------------------
+Fri Jun  6 06:06:06 UTC 2025 - ohering@suse.de
+
+- Enable debug logs for hv_kvp_daemon (a9c0b33e) (bsc#1244154)
+
+-------------------------------------------------------------------
+Wed Jan  1 01:01:01 UTC 2025 - ohering@suse.de
+
+- update route parsing in kvp daemon (9bbb8a07)
+- reduce resource usage in hv_kvp_daemon (175c71c2)
+- reduce resouce usage in hv_get_dns_info helper (a4d024fe)
+- hv_kvp_daemon: Pass NIC name to hv_get_dns_info as well (07dfa6e8)
+- terminate fcopy daemon if read from uio fails (a9640fcd)
+- change permissions of NetworkManager configuration file (91ae69c7)
+- Fix a complier warning in the fcopy uio daemon (cb1b78f1)
+- remove obsolete kvptest.ps1.txt which failed since a decade
+- remove obsolete rpm postinstall code for SLE11SP2
+
 -------------------------------------------------------------------
 Tue Oct 22 22:22:22 UTC 2024 - ohering@suse.de
 

hyper-v.compare-with-upstream.sh

@@ -1,6 +1,6 @@
-d=~/work/src/kernel/kerncvs.kernel.master
+d=~/work/src/kernel/kerncvs.kernel.git
 diff -u hyper-v.tools.hv.hv_vss_daemon.c ${d}/tools/hv/hv_vss_daemon.c
 diff -u hyper-v.tools.hv.hv_kvp_daemon.c ${d}/tools/hv/hv_kvp_daemon.c
-diff -u hyper-v.tools.hv.hv_fcopy_daemon.c ${d}/tools/hv/hv_fcopy_daemon.c
+diff -u hyper-v.tools.hv.hv_fcopy_uio_daemon.c ${d}/tools/hv/hv_fcopy_uio_daemon.c
 diff -u hyper-v.include.linux.hyperv.h ${d}/include/uapi/linux/hyperv.h
 diff -u hyper-v.lsvmbus.py ${d}/tools/hv/lsvmbus

hyper-v.kvptest.ps1.txt

@@ -1,49 +0,0 @@
-# Windows PowerShell script to test Key Value Pair functionality
-#
-# http://blogs.msdn.com/b/virtual_pc_guy/archive/2008/11/18/hyper-v-script-looking-at-kvp-guestintrinsicexchangeitems.aspx
-#
-# Per default execution of scripts is disabled.
-# http://technet.microsoft.com/en-us/library/ee176949.aspx
-# The command 'Set-ExecutionPolicy RemoteSigned' will enable it.
-#
-# Filter for parsing XML data
-filter Import-CimXml
-{
-   # Create new XML object from input
-   $CimXml = [Xml]$_
-   $CimObj = New-Object -TypeName System.Object
-
-   # Iterate over the data and pull out just the value name and data for each entry
-   foreach ($CimProperty in $CimXml.SelectNodes("/INSTANCE/PROPERTY[@NAME='Name']"))
-      {
-         $CimObj | Add-Member -MemberType NoteProperty -Name $CimProperty.NAME -Value $CimProperty.VALUE
-      }
-
-   foreach ($CimProperty in $CimXml.SelectNodes("/INSTANCE/PROPERTY[@NAME='Data']"))
-      {
-         $CimObj | Add-Member -MemberType NoteProperty -Name $CimProperty.NAME -Value $CimProperty.VALUE
-      }
-
-   # Display output
-   $CimObj
-}
-
-# Prompt for the Hyper-V Server to use
-$HyperVServer = Read-Host "Specify the Hyper-V Server to use (enter '.' for the local computer)"
-
-# Prompt for the virtual machine to use
-$VMName = Read-Host "Specify the name of the virtual machine"
-
-# Get the virtual machine object
-$query = "Select * From Msvm_ComputerSystem Where ElementName='" + $VMName + "'"
-$Vm = gwmi -namespace root\virtualization -query $query -computername $HyperVServer
-
-# Get the KVP Object
-$query = "Associators of {$Vm} Where AssocClass=Msvm_SystemDevice ResultClass=Msvm_KvpExchangeComponent"
-$Kvp = gwmi -namespace root\virtualization -query $query -computername $HyperVServer
-
-Write-Host
-Write-Host "Guest KVP information for" $VMName
-
-# Filter the results
-$Kvp.GuestIntrinsicExchangeItems | Import-CimXml

hyper-v.spec

@@ -43,7 +43,6 @@ URL:            http://www.kernel.org
 Version:        9
 Release:        0
 Source0:        hyper-v.lsvmbus.py
-Source5:        hyper-v.kvptest.ps1.txt
 Source7:        hyper-v.compare-with-upstream.sh
 Source8:        hyper-v.tools.hv.vmbus_bufring.h
 Source9:        hyper-v.include.linux.hyperv.h
@@ -63,7 +62,6 @@ This package contains the Microsoft Hyper-V tools.
 
 %prep
 %setup -Tc
-cp -avL %{S:5} kvptest.ps1.txt
 cp -vL %{S:8} %vmbus_bufring.h
 cp -vL %{S:9} %include_uapi_linux_hyperv.h
 cp -vL %{S:10} .
@@ -263,58 +261,15 @@ chmod 755 %buildroot${bindir}/${helper}
 %?python3_fix_shebang
 
 %files
-%doc kvptest.ps1.txt
 %_unitdir/*
 %_udevrulesdir/*
 %_sbindir/*
 %helper_dir
 
-%pre
-# hv_kvp_daemon in SLES11 SP2 stored temporary state files in /var/opt
-# move them to /var/lib and remove old directory, if possible.
-if test -d /var/opt/hyperv
-then
-	if mkdir -p -v -m 0755 /var/lib/hyperv
-	then
-		cd /var/lib/hyperv
-		for oldfile in /var/opt/hyperv/ifcfg-* /var/opt/hyperv/.kvp_pool_*
-		do
-			if test -e "${oldfile}"
-			then
-				mv -vfb "${oldfile}" . || :
-			fi
-		done
-		cd - >/dev/null
-	fi
-	rmdir -v  /var/opt/hyperv || :
-fi
-: nothing to do in case of systemd
-
+# the relevant part is systemctl daemon-reload, due to udev triggers
 %post
-board_vendor=
-product_name=
-if cd /sys/class/dmi/id 2>/dev/null
-then
-	if test -r board_vendor
-	then
-		board_vendor="`cat board_vendor`"
-	fi
-	if test -r product_name
-	then
-		product_name="`cat product_name`"
-	fi
-	cd - >/dev/null
-fi
-if test "${board_vendor}" = "Microsoft Corporation" -a "${product_name}" = "Virtual Machine"
-then
-: nothing to do in case of systemd
-fi
-
-%preun
-: nothing to do in case of systemd
-
+%service_add_post %hv_kvp_daemon %hv_vss_daemon %hv_fcopy_daemon %hv_fcopy_uio_daemon
 %postun
-# no restart on update because the daemon can not be restarted
-: nothing to do in case of systemd
+%service_del_postun_without_restart %hv_kvp_daemon %hv_vss_daemon %hv_fcopy_daemon %hv_fcopy_uio_daemon
 
 %changelog

hyper-v.tools.hv.hv_fcopy_uio_daemon.c

@@ -35,9 +35,10 @@
 #define WIN8_SRV_MINOR		1
 #define WIN8_SRV_VERSION	(WIN8_SRV_MAJOR << 16 | WIN8_SRV_MINOR)
 
-#define MAX_FOLDER_NAME		15
-#define MAX_PATH_LEN		15
-#define FCOPY_UIO		"/sys/bus/vmbus/devices/eb765408-105f-49b6-b4aa-c123b64d17d4/uio"
+#define FCOPY_DEVICE_PATH(subdir) \
+	"/sys/bus/vmbus/devices/eb765408-105f-49b6-b4aa-c123b64d17d4/" #subdir
+#define FCOPY_UIO_PATH          FCOPY_DEVICE_PATH(uio)
+#define FCOPY_CHANNELS_PATH     FCOPY_DEVICE_PATH(channels)
 
 #define FCOPY_VER_COUNT		1
 static const int fcopy_versions[] = {
@@ -49,9 +50,62 @@ static const int fw_versions[] = {
 	UTIL_FW_VERSION
 };
 
-#define HV_RING_SIZE		0x4000 /* 16KB ring buffer size */
+static uint32_t get_ring_buffer_size(void)
+{
+	char ring_path[PATH_MAX];
+	DIR *dir;
+	struct dirent *entry;
+	struct stat st;
+	uint32_t ring_size = 0;
+	int retry_count = 0;
 
-unsigned char desc[HV_RING_SIZE];
+	/* Find the channel directory */
+	dir = opendir(FCOPY_CHANNELS_PATH);
+	if (!dir) {
+		usleep(100 * 1000); /* Avoid race with kernel, wait 100ms and retry once */
+		dir = opendir(FCOPY_CHANNELS_PATH);
+		if (!dir) {
+			syslog(LOG_ERR, "Failed to open channels directory: %s", strerror(errno));
+			return 0;
+		}
+	}
+
+retry_once:
+	while ((entry = readdir(dir)) != NULL) {
+		if (entry->d_type == DT_DIR && strcmp(entry->d_name, ".") != 0 &&
+		    strcmp(entry->d_name, "..") != 0) {
+			snprintf(ring_path, sizeof(ring_path), "%s/%s/ring",
+				 FCOPY_CHANNELS_PATH, entry->d_name);
+
+			if (stat(ring_path, &st) == 0) {
+				/*
+				 * stat returns size of Tx, Rx rings combined,
+				 * so take half of it for individual ring size.
+				 */
+				ring_size = (uint32_t)st.st_size / 2;
+				syslog(LOG_INFO, "Ring buffer size from %s: %u bytes",
+				       ring_path, ring_size);
+				break;
+			}
+		}
+	}
+
+	if (!ring_size && retry_count == 0) {
+		retry_count = 1;
+		rewinddir(dir);
+		usleep(100 * 1000); /* Wait 100ms and retry once */
+		goto retry_once;
+	}
+
+	closedir(dir);
+
+	if (!ring_size)
+		syslog(LOG_ERR, "Could not determine ring size");
+
+	return ring_size;
+}
+
+static unsigned char *desc;
 
 static int target_fd;
 static char target_fname[PATH_MAX];
@@ -64,8 +118,11 @@ static int hv_fcopy_create_file(char *file_name, char *path_name, __u32 flags)
 
 	filesize = 0;
 	p = path_name;
-	snprintf(target_fname, sizeof(target_fname), "%s/%s",
-		 path_name, file_name);
+	if (snprintf(target_fname, sizeof(target_fname), "%s/%s",
+		     path_name, file_name) >= sizeof(target_fname)) {
+		syslog(LOG_ERR, "target file name is too long: %s/%s", path_name, file_name);
+		goto done;
+	}
 
 	/*
 	 * Check to see if the path is already in place; if not,
@@ -272,7 +329,7 @@ static void wcstoutf8(char *dest, const __u16 *src, size_t dest_size)
 {
 	size_t len = 0;
 
-	while (len < dest_size) {
+	while (len < dest_size && *src) {
 		if (src[len] < 0x80)
 			dest[len++] = (char)(*src++);
 		else
@@ -284,27 +341,15 @@ static void wcstoutf8(char *dest, const __u16 *src, size_t dest_size)
 
 static int hv_fcopy_start(struct hv_start_fcopy *smsg_in)
 {
+	/*
+	 * file_name and path_name should have same length with appropriate
+	 * member of hv_start_fcopy.
+	 */
+	char file_name[W_MAX_PATH], path_name[W_MAX_PATH];
+
 	setlocale(LC_ALL, "en_US.utf8");
-	size_t file_size, path_size;
-	char *file_name, *path_name;
-	char *in_file_name = (char *)smsg_in->file_name;
-	char *in_path_name = (char *)smsg_in->path_name;
-
-	file_size = wcstombs(NULL, (const wchar_t *restrict)in_file_name, 0) + 1;
-	path_size = wcstombs(NULL, (const wchar_t *restrict)in_path_name, 0) + 1;
-
-	file_name = (char *)malloc(file_size * sizeof(char));
-	path_name = (char *)malloc(path_size * sizeof(char));
-
-	if (!file_name || !path_name) {
-		free(file_name);
-		free(path_name);
-		syslog(LOG_ERR, "Can't allocate memory for file name and/or path name");
-		return HV_E_FAIL;
-	}
-
-	wcstoutf8(file_name, (__u16 *)in_file_name, file_size);
-	wcstoutf8(path_name, (__u16 *)in_path_name, path_size);
+	wcstoutf8(file_name, smsg_in->file_name, W_MAX_PATH - 1);
+	wcstoutf8(path_name, smsg_in->path_name, W_MAX_PATH - 1);
 
 	return hv_fcopy_create_file(file_name, path_name, smsg_in->copy_flags);
 }
@@ -408,9 +453,9 @@ int main(int argc, char *argv[])
 	int daemonize = 1, long_index = 0, opt, ret = -EINVAL;
 	struct vmbus_br txbr, rxbr;
 	void *ring;
-	uint32_t len = HV_RING_SIZE;
-	char uio_name[MAX_FOLDER_NAME] = {0};
-	char uio_dev_path[MAX_PATH_LEN] = {0};
+	uint32_t ring_size, len;
+	char uio_name[NAME_MAX] = {0};
+	char uio_dev_path[PATH_MAX] = {0};
 
 	static struct option long_options[] = {
 		{"help",	no_argument,	   0,  'h' },
@@ -439,7 +484,20 @@ int main(int argc, char *argv[])
 	openlog("HV_UIO_FCOPY", 0, LOG_USER);
 	syslog(LOG_INFO, "starting; pid is:%d", getpid());
 
-	fcopy_get_first_folder(FCOPY_UIO, uio_name);
+	ring_size = get_ring_buffer_size();
+	if (!ring_size) {
+		ret = -ENODEV;
+		goto exit;
+	}
+
+	desc = malloc(ring_size * sizeof(unsigned char));
+	if (!desc) {
+		syslog(LOG_ERR, "malloc failed for desc buffer");
+		ret = -ENOMEM;
+		goto exit;
+	}
+
+	fcopy_get_first_folder(FCOPY_UIO_PATH, uio_name);
 	snprintf(uio_dev_path, sizeof(uio_dev_path), "/dev/%s", uio_name);
 	fcopy_fd = open(uio_dev_path, O_RDWR);
 
@@ -447,17 +505,17 @@ int main(int argc, char *argv[])
 		syslog(LOG_ERR, "open %s failed; error: %d %s",
 		       uio_dev_path, errno, strerror(errno));
 		ret = fcopy_fd;
-		goto exit;
+		goto free_desc;
 	}
 
-	ring = vmbus_uio_map(&fcopy_fd, HV_RING_SIZE);
+	ring = vmbus_uio_map(&fcopy_fd, ring_size);
 	if (!ring) {
 		ret = errno;
 		syslog(LOG_ERR, "mmap ringbuffer failed; error: %d %s", ret, strerror(ret));
 		goto close;
 	}
-	vmbus_br_setup(&txbr, ring, HV_RING_SIZE);
-	vmbus_br_setup(&rxbr, (char *)ring + HV_RING_SIZE, HV_RING_SIZE);
+	vmbus_br_setup(&txbr, ring, ring_size);
+	vmbus_br_setup(&rxbr, (char *)ring + ring_size, ring_size);
 
 	rxbr.vbr->imask = 0;
 
@@ -468,11 +526,13 @@ int main(int argc, char *argv[])
 		 */
 		ret = pread(fcopy_fd, &tmp, sizeof(int), 0);
 		if (ret < 0) {
+			if (errno == EINTR || errno == EAGAIN)
+				continue;
 			syslog(LOG_ERR, "pread failed: %s", strerror(errno));
-			continue;
+			goto close;
 		}
 
-		len = HV_RING_SIZE;
+		len = ring_size;
 		ret = rte_vmbus_chan_recv_raw(&rxbr, desc, &len);
 		if (unlikely(ret <= 0)) {
 			/* This indicates a failure to communicate (or worse) */
@@ -492,6 +552,8 @@ int main(int argc, char *argv[])
 	}
 close:
 	close(fcopy_fd);
+free_desc:
+	free(desc);
 exit:
 	return ret;
 }

hyper-v.tools.hv.hv_get_dns_info.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/bin/sh
 
 # This script parses /etc/resolv.conf to retrive DNS information.
 # In the interest of keeping the KVP daemon code free of distro specific
@@ -10,7 +10,8 @@
 # this script can be based on the Network Manager APIs for retrieving DNS
 # entries.
 
-if test -r /etc/resolv.conf
+if test -f /etc/resolv.conf
 then
-	awk -- '/^nameserver/ { print $2 }' /etc/resolv.conf
+	exec awk -- '/^nameserver/ { print $2 }' /etc/resolv.conf
 fi
+exit 0

hyper-v.tools.hv.hv_kvp_daemon.c

@@ -24,6 +24,7 @@
 
 #include <sys/poll.h>
 #include <sys/utsname.h>
+#include <stdbool.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <unistd.h>
@@ -83,6 +84,7 @@ enum {
 };
 
 static int in_hand_shake;
+static int debug;
 
 static char *os_name = "";
 static char *os_major = "";
@@ -183,6 +185,20 @@ static void kvp_update_file(int pool)
 	kvp_release_lock(pool);
 }
 
+static void kvp_dump_initial_pools(int pool)
+{
+	int i;
+
+	syslog(LOG_DEBUG, "===Start dumping the contents of pool %d ===\n",
+	       pool);
+
+	for (i = 0; i < kvp_file_info[pool].num_records; i++)
+		syslog(LOG_DEBUG, "pool: %d, %d/%d key=%s val=%s\n",
+		       pool, i + 1, kvp_file_info[pool].num_records,
+		       kvp_file_info[pool].records[i].key,
+		       kvp_file_info[pool].records[i].value);
+}
+
 static void kvp_update_mem_state(int pool)
 {
 	FILE *filep;
@@ -270,6 +286,8 @@ static int kvp_file_init(void)
 			return 1;
 		kvp_file_info[i].num_records = 0;
 		kvp_update_mem_state(i);
+		if (debug)
+			kvp_dump_initial_pools(i);
 	}
 
 	return 0;
@@ -297,6 +315,9 @@ static int kvp_key_delete(int pool, const __u8 *key, int key_size)
 		 * Found a match; just move the remaining
 		 * entries up.
 		 */
+		if (debug)
+			syslog(LOG_DEBUG, "%s: deleting the KVP: pool=%d key=%s val=%s",
+			       __func__, pool, record[i].key, record[i].value);
 		if (i == (num_records - 1)) {
 			kvp_file_info[pool].num_records--;
 			kvp_update_file(pool);
@@ -315,20 +336,36 @@ static int kvp_key_delete(int pool, const __u8 *key, int key_size)
 		kvp_update_file(pool);
 		return 0;
 	}
+
+	if (debug)
+		syslog(LOG_DEBUG, "%s: could not delete KVP: pool=%d key=%s. Record not found",
+		       __func__, pool, key);
+
 	return 1;
 }
 
 static int kvp_key_add_or_modify(int pool, const __u8 *key, int key_size,
 				 const __u8 *value, int value_size)
 {
-	int i;
-	int num_records;
 	struct kvp_record *record;
+	int num_records;
 	int num_blocks;
+	int i;
+
+	if (debug)
+		syslog(LOG_DEBUG, "%s: got a KVP: pool=%d key=%s val=%s",
+		       __func__, pool, key, value);
 
 	if ((key_size > HV_KVP_EXCHANGE_MAX_KEY_SIZE) ||
-		(value_size > HV_KVP_EXCHANGE_MAX_VALUE_SIZE))
+		(value_size > HV_KVP_EXCHANGE_MAX_VALUE_SIZE)) {
+		syslog(LOG_ERR, "%s: Too long key or value: key=%s, val=%s",
+		       __func__, key, value);
+
+		if (debug)
+			syslog(LOG_DEBUG, "%s: Too long key or value: pool=%d, key=%s, val=%s",
+			       __func__, pool, key, value);
 		return 1;
+	}
 
 	/*
 	 * First update the in-memory state.
@@ -348,6 +385,9 @@ static int kvp_key_add_or_modify(int pool, const __u8 *key, int key_size,
 		 */
 		memcpy(record[i].value, value, value_size);
 		kvp_update_file(pool);
+		if (debug)
+			syslog(LOG_DEBUG, "%s: updated: pool=%d key=%s val=%s",
+			       __func__, pool, key, value);
 		return 0;
 	}
 
@@ -359,8 +399,10 @@ static int kvp_key_add_or_modify(int pool, const __u8 *key, int key_size,
 		record = realloc(record, sizeof(struct kvp_record) *
 			 ENTRIES_PER_BLOCK * (num_blocks + 1));
 
-		if (record == NULL)
+		if (!record) {
+			syslog(LOG_ERR, "%s: Memory alloc failure", __func__);
 			return 1;
+		}
 		kvp_file_info[pool].num_blocks++;
 
 	}
@@ -368,6 +410,11 @@ static int kvp_key_add_or_modify(int pool, const __u8 *key, int key_size,
 	memcpy(record[i].key, key, key_size);
 	kvp_file_info[pool].records = record;
 	kvp_file_info[pool].num_records++;
+
+	if (debug)
+		syslog(LOG_DEBUG, "%s: added: pool=%d key=%s val=%s",
+		       __func__, pool, key, value);
+
 	kvp_update_file(pool);
 	return 0;
 }
@@ -677,6 +724,88 @@ static void kvp_process_ipconfig_file(char *cmd,
 	pclose(file);
 }
 
+static bool kvp_verify_ip_address(const void *address_string)
+{
+	char verify_buf[sizeof(struct in6_addr)];
+
+	if (inet_pton(AF_INET, address_string, verify_buf) == 1)
+		return true;
+	if (inet_pton(AF_INET6, address_string, verify_buf) == 1)
+		return true;
+	return false;
+}
+
+static void kvp_extract_routes(const char *line, void **output, size_t *remaining)
+{
+	static const char needle[] = "via ";
+	const char *match, *haystack = line;
+
+	while ((match = strstr(haystack, needle))) {
+		const char *address, *next_char;
+
+		/* Address starts after needle. */
+		address = match + strlen(needle);
+
+		/* The char following address is a space or end of line. */
+		next_char = strpbrk(address, " \t\\");
+		if (!next_char)
+			next_char = address + strlen(address) + 1;
+
+		/* Enough room for address and semicolon. */
+		if (*remaining >= (next_char - address) + 1) {
+			memcpy(*output, address, next_char - address);
+			/* Terminate string for verification. */
+			memcpy(*output + (next_char - address), "", 1);
+			if (kvp_verify_ip_address(*output)) {
+				/* Advance output buffer. */
+				*output += next_char - address;
+				*remaining -= next_char - address;
+
+				/* Each address needs a trailing semicolon. */
+				memcpy(*output, ";", 1);
+				*output += 1;
+				*remaining -= 1;
+			}
+		}
+		haystack = next_char;
+	}
+}
+
+static void kvp_get_gateway(void *buffer, size_t buffer_len)
+{
+	static const char needle[] = "default ";
+	FILE *f;
+	void *output = buffer;
+	char *line = NULL;
+	size_t alloc_size = 0, remaining = buffer_len - 1;
+	ssize_t num_chars;
+
+	/* Show route information in a single line, for each address family */
+	f = popen("ip --oneline -4 route show;ip --oneline -6 route show", "r");
+	if (!f) {
+		/* Convert buffer into C-String. */
+		memcpy(output, "", 1);
+		return;
+	}
+	while ((num_chars = getline(&line, &alloc_size, f)) > 0) {
+		/* Skip short lines. */
+		if (num_chars <= strlen(needle))
+			continue;
+		/* Skip lines without default route. */
+		if (memcmp(line, needle, strlen(needle)))
+			continue;
+		/* Remove trailing newline to simplify further parsing. */
+		if (line[num_chars - 1] == '\n')
+			line[num_chars - 1] = '\0';
+		/* Search routes after match. */
+		kvp_extract_routes(line + strlen(needle), &output, &remaining);
+	}
+	/* Convert buffer into C-String. */
+	memcpy(output, "", 1);
+	free(line);
+	pclose(f);
+}
+
 static void kvp_get_ipconfig_info(char *if_name,
 				 struct hv_kvp_ipaddr_value *buffer)
 {
@@ -685,30 +814,7 @@ static void kvp_get_ipconfig_info(char *if_name,
 	char *p;
 	FILE *file;
 
-	/*
-	 * Get the address of default gateway (ipv4).
-	 */
-	sprintf(cmd, "%s %s", "ip route show dev", if_name);
-	strcat(cmd, " | awk '/default/ {print $3 }'");
-
-	/*
-	 * Execute the command to gather gateway info.
-	 */
-	kvp_process_ipconfig_file(cmd, (char *)buffer->gate_way,
-				(MAX_GATEWAY_SIZE * 2), INET_ADDRSTRLEN, 0);
-
-	/*
-	 * Get the address of default gateway (ipv6).
-	 */
-	sprintf(cmd, "%s %s", "ip -f inet6  route show dev", if_name);
-	strcat(cmd, " | awk '/default/ {print $3 }'");
-
-	/*
-	 * Execute the command to gather gateway info (ipv6).
-	 */
-	kvp_process_ipconfig_file(cmd, (char *)buffer->gate_way,
-				(MAX_GATEWAY_SIZE * 2), INET6_ADDRSTRLEN, 1);
-
+	kvp_get_gateway(buffer->gate_way, sizeof(buffer->gate_way));
 
 	/*
 	 * Gather the DNS state.
@@ -725,7 +831,7 @@ static void kvp_get_ipconfig_info(char *if_name,
 	 * .
 	 */
 
-	sprintf(cmd, KVP_SCRIPTS_PATH "%s",  "hv_get_dns_info");
+	sprintf(cmd, "exec %s %s", KVP_SCRIPTS_PATH "hv_get_dns_info", if_name);
 
 	/*
 	 * Execute the command to gather DNS info.
@@ -742,7 +848,7 @@ static void kvp_get_ipconfig_info(char *if_name,
 	 * Enabled: DHCP enabled.
 	 */
 
-	sprintf(cmd, KVP_SCRIPTS_PATH "%s %s", "hv_get_dhcp_info", if_name);
+	sprintf(cmd, "exec %s %s", KVP_SCRIPTS_PATH "hv_get_dhcp_info", if_name);
 
 	file = popen(cmd, "r");
 	if (file == NULL)
@@ -1606,8 +1712,9 @@ static int kvp_set_ip_info(char *if_name, struct hv_kvp_ipaddr_value *new_val)
 	 * invoke the external script to do its magic.
 	 */
 
-	str_len = snprintf(cmd, sizeof(cmd), KVP_SCRIPTS_PATH "%s %s %s",
-			   "hv_set_ifconfig", if_filename, nm_filename);
+	str_len = snprintf(cmd, sizeof(cmd), "exec %s %s %s",
+			   KVP_SCRIPTS_PATH "hv_set_ifconfig",
+			   if_filename, nm_filename);
 	/*
 	 * This is a little overcautious, but it's necessary to suppress some
 	 * false warnings from gcc 8.0.1.
@@ -1663,6 +1770,7 @@ void print_usage(char *argv[])
 	fprintf(stderr, "Usage: %s [options]\n"
 		"Options are:\n"
 		"  -n, --no-daemon        stay in foreground, don't daemonize\n"
+		"  -d, --debug            Enable debug logs(syslog debug by default)\n"
 		"  -h, --help             print this help\n", argv[0]);
 }
 
@@ -1684,10 +1792,11 @@ int main(int argc, char *argv[])
 	static struct option long_options[] = {
 		{"help",	no_argument,	   0,  'h' },
 		{"no-daemon",	no_argument,	   0,  'n' },
+		{"debug",	no_argument,	   0,  'd' },
 		{0,		0,		   0,  0   }
 	};
 
-	while ((opt = getopt_long(argc, argv, "hn", long_options,
+	while ((opt = getopt_long(argc, argv, "hnd", long_options,
 				  &long_index)) != -1) {
 		switch (opt) {
 		case 'n':
@@ -1696,6 +1805,9 @@ int main(int argc, char *argv[])
 		case 'h':
 			print_usage(argv);
 			exit(0);
+		case 'd':
+			debug = 1;
+			break;
 		default:
 			print_usage(argv);
 			exit(EXIT_FAILURE);
@@ -1718,6 +1830,9 @@ int main(int argc, char *argv[])
 	 */
 	kvp_get_domain_name(full_domain_name, sizeof(full_domain_name));
 
+	if (debug)
+		syslog(LOG_INFO, "Logging debug info in syslog(debug)");
+
 	if (kvp_file_init()) {
 		syslog(LOG_ERR, "Failed to initialize the pools");
 		exit(EXIT_FAILURE);