Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1638 insertions, 0 deletions

diff --git a/tools/hv/hv_kvp_daemon.c b/tools/hv/hv_kvp_daemon.c
new file mode 100644
index 000000000..27f5e7dfc
--- /dev/null
+++ b/tools/hv/hv_kvp_daemon.c
@@ -0,0 +1,1638 @@
+/*
+ * An implementation of key value pair (KVP) functionality for Linux.
+ *
+ *
+ * Copyright (C) 2010, Novell, Inc.
+ * Author : K. Y. Srinivasan <ksrinivasan@novell.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ * NON INFRINGEMENT.  See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
+
+#include <sys/poll.h>
+#include <sys/utsname.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <ctype.h>
+#include <errno.h>
+#include <arpa/inet.h>
+#include <linux/hyperv.h>
+#include <ifaddrs.h>
+#include <netdb.h>
+#include <syslog.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <dirent.h>
+#include <net/if.h>
+#include <limits.h>
+#include <getopt.h>
+
+/*
+ * KVP protocol: The user mode component first registers with the
+ * kernel component. Subsequently, the kernel component requests, data
+ * for the specified keys. In response to this message the user mode component
+ * fills in the value corresponding to the specified key. We overload the
+ * sequence field in the cn_msg header to define our KVP message types.
+ *
+ * We use this infrastructure for also supporting queries from user mode
+ * application for state that may be maintained in the KVP kernel component.
+ *
+ */
+
+
+enum key_index {
+	FullyQualifiedDomainName = 0,
+	IntegrationServicesVersion, /*This key is serviced in the kernel*/
+	NetworkAddressIPv4,
+	NetworkAddressIPv6,
+	OSBuildNumber,
+	OSName,
+	OSMajorVersion,
+	OSMinorVersion,
+	OSVersion,
+	ProcessorArchitecture
+};
+
+
+enum {
+	IPADDR = 0,
+	NETMASK,
+	GATEWAY,
+	DNS
+};
+
+static int in_hand_shake;
+
+static char *os_name = "";
+static char *os_major = "";
+static char *os_minor = "";
+static char *processor_arch;
+static char *os_build;
+static char *os_version;
+static char *lic_version = "Unknown version";
+static char full_domain_name[HV_KVP_EXCHANGE_MAX_VALUE_SIZE];
+static struct utsname uts_buf;
+
+/*
+ * The location of the interface configuration file.
+ */
+
+#define KVP_CONFIG_LOC	"/var/lib/hyperv"
+
+#ifndef KVP_SCRIPTS_PATH
+#define KVP_SCRIPTS_PATH "/usr/libexec/hypervkvpd/"
+#endif
+
+#define KVP_NET_DIR "/sys/class/net/"
+
+#define MAX_FILE_NAME 100
+#define ENTRIES_PER_BLOCK 50
+
+struct kvp_record {
+	char key[HV_KVP_EXCHANGE_MAX_KEY_SIZE];
+	char value[HV_KVP_EXCHANGE_MAX_VALUE_SIZE];
+};
+
+struct kvp_file_state {
+	int fd;
+	int num_blocks;
+	struct kvp_record *records;
+	int num_records;
+	char fname[MAX_FILE_NAME];
+};
+
+static struct kvp_file_state kvp_file_info[KVP_POOL_COUNT];
+
+static void kvp_acquire_lock(int pool)
+{
+	struct flock fl = {F_WRLCK, SEEK_SET, 0, 0, 0};
+	fl.l_pid = getpid();
+
+	if (fcntl(kvp_file_info[pool].fd, F_SETLKW, &fl) == -1) {
+		syslog(LOG_ERR, "Failed to acquire the lock pool: %d; error: %d %s", pool,
+				errno, strerror(errno));
+		exit(EXIT_FAILURE);
+	}
+}
+
+static void kvp_release_lock(int pool)
+{
+	struct flock fl = {F_UNLCK, SEEK_SET, 0, 0, 0};
+	fl.l_pid = getpid();
+
+	if (fcntl(kvp_file_info[pool].fd, F_SETLK, &fl) == -1) {
+		syslog(LOG_ERR, "Failed to release the lock pool: %d; error: %d %s", pool,
+				errno, strerror(errno));
+		exit(EXIT_FAILURE);
+	}
+}
+
+static void kvp_update_file(int pool)
+{
+	FILE *filep;
+
+	/*
+	 * We are going to write our in-memory registry out to
+	 * disk; acquire the lock first.
+	 */
+	kvp_acquire_lock(pool);
+
+	filep = fopen(kvp_file_info[pool].fname, "we");
+	if (!filep) {
+		syslog(LOG_ERR, "Failed to open file, pool: %d; error: %d %s", pool,
+				errno, strerror(errno));
+		kvp_release_lock(pool);
+		exit(EXIT_FAILURE);
+	}
+
+	fwrite(kvp_file_info[pool].records, sizeof(struct kvp_record),
+				kvp_file_info[pool].num_records, filep);
+
+	if (ferror(filep) || fclose(filep)) {
+		kvp_release_lock(pool);
+		syslog(LOG_ERR, "Failed to write file, pool: %d", pool);
+		exit(EXIT_FAILURE);
+	}
+
+	kvp_release_lock(pool);
+}
+
+static void kvp_update_mem_state(int pool)
+{
+	FILE *filep;
+	size_t records_read = 0;
+	struct kvp_record *record = kvp_file_info[pool].records;
+	struct kvp_record *readp;
+	int num_blocks = kvp_file_info[pool].num_blocks;
+	int alloc_unit = sizeof(struct kvp_record) * ENTRIES_PER_BLOCK;
+
+	kvp_acquire_lock(pool);
+
+	filep = fopen(kvp_file_info[pool].fname, "re");
+	if (!filep) {
+		syslog(LOG_ERR, "Failed to open file, pool: %d; error: %d %s", pool,
+				errno, strerror(errno));
+		kvp_release_lock(pool);
+		exit(EXIT_FAILURE);
+	}
+	for (;;) {
+		readp = &record[records_read];
+		records_read += fread(readp, sizeof(struct kvp_record),
+				ENTRIES_PER_BLOCK * num_blocks - records_read,
+				filep);
+
+		if (ferror(filep)) {
+			syslog(LOG_ERR,
+				"Failed to read file, pool: %d; error: %d %s",
+				 pool, errno, strerror(errno));
+			kvp_release_lock(pool);
+			exit(EXIT_FAILURE);
+		}
+
+		if (!feof(filep)) {
+			/*
+			 * We have more data to read.
+			 */
+			num_blocks++;
+			record = realloc(record, alloc_unit * num_blocks);
+
+			if (record == NULL) {
+				syslog(LOG_ERR, "malloc failed");
+				kvp_release_lock(pool);
+				exit(EXIT_FAILURE);
+			}
+			continue;
+		}
+		break;
+	}
+
+	kvp_file_info[pool].num_blocks = num_blocks;
+	kvp_file_info[pool].records = record;
+	kvp_file_info[pool].num_records = records_read;
+
+	fclose(filep);
+	kvp_release_lock(pool);
+}
+
+static int kvp_file_init(void)
+{
+	int  fd;
+	char *fname;
+	int i;
+	int alloc_unit = sizeof(struct kvp_record) * ENTRIES_PER_BLOCK;
+
+	if (access(KVP_CONFIG_LOC, F_OK)) {
+		if (mkdir(KVP_CONFIG_LOC, 0755 /* rwxr-xr-x */)) {
+			syslog(LOG_ERR, "Failed to create '%s'; error: %d %s", KVP_CONFIG_LOC,
+					errno, strerror(errno));
+			exit(EXIT_FAILURE);
+		}
+	}
+
+	for (i = 0; i < KVP_POOL_COUNT; i++) {
+		fname = kvp_file_info[i].fname;
+		sprintf(fname, "%s/.kvp_pool_%d", KVP_CONFIG_LOC, i);
+		fd = open(fname, O_RDWR | O_CREAT | O_CLOEXEC, 0644 /* rw-r--r-- */);
+
+		if (fd == -1)
+			return 1;
+
+		kvp_file_info[i].fd = fd;
+		kvp_file_info[i].num_blocks = 1;
+		kvp_file_info[i].records = malloc(alloc_unit);
+		if (kvp_file_info[i].records == NULL)
+			return 1;
+		kvp_file_info[i].num_records = 0;
+		kvp_update_mem_state(i);
+	}
+
+	return 0;
+}
+
+static int kvp_key_delete(int pool, const __u8 *key, int key_size)
+{
+	int i;
+	int j, k;
+	int num_records;
+	struct kvp_record *record;
+
+	/*
+	 * First update the in-memory state.
+	 */
+	kvp_update_mem_state(pool);
+
+	num_records = kvp_file_info[pool].num_records;
+	record = kvp_file_info[pool].records;
+
+	for (i = 0; i < num_records; i++) {
+		if (memcmp(key, record[i].key, key_size))
+			continue;
+		/*
+		 * Found a match; just move the remaining
+		 * entries up.
+		 */
+		if (i == (num_records - 1)) {
+			kvp_file_info[pool].num_records--;
+			kvp_update_file(pool);
+			return 0;
+		}
+
+		j = i;
+		k = j + 1;
+		for (; k < num_records; k++) {
+			strcpy(record[j].key, record[k].key);
+			strcpy(record[j].value, record[k].value);
+			j++;
+		}
+
+		kvp_file_info[pool].num_records--;
+		kvp_update_file(pool);
+		return 0;
+	}
+	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_blocks;
+
+	if ((key_size > HV_KVP_EXCHANGE_MAX_KEY_SIZE) ||
+		(value_size > HV_KVP_EXCHANGE_MAX_VALUE_SIZE))
+		return 1;
+
+	/*
+	 * First update the in-memory state.
+	 */
+	kvp_update_mem_state(pool);
+
+	num_records = kvp_file_info[pool].num_records;
+	record = kvp_file_info[pool].records;
+	num_blocks = kvp_file_info[pool].num_blocks;
+
+	for (i = 0; i < num_records; i++) {
+		if (memcmp(key, record[i].key, key_size))
+			continue;
+		/*
+		 * Found a match; just update the value -
+		 * this is the modify case.
+		 */
+		memcpy(record[i].value, value, value_size);
+		kvp_update_file(pool);
+		return 0;
+	}
+
+	/*
+	 * Need to add a new entry;
+	 */
+	if (num_records == (ENTRIES_PER_BLOCK * num_blocks)) {
+		/* Need to allocate a larger array for reg entries. */
+		record = realloc(record, sizeof(struct kvp_record) *
+			 ENTRIES_PER_BLOCK * (num_blocks + 1));
+
+		if (record == NULL)
+			return 1;
+		kvp_file_info[pool].num_blocks++;
+
+	}
+	memcpy(record[i].value, value, value_size);
+	memcpy(record[i].key, key, key_size);
+	kvp_file_info[pool].records = record;
+	kvp_file_info[pool].num_records++;
+	kvp_update_file(pool);
+	return 0;
+}
+
+static int kvp_get_value(int pool, const __u8 *key, int key_size, __u8 *value,
+			int value_size)
+{
+	int i;
+	int num_records;
+	struct kvp_record *record;
+
+	if ((key_size > HV_KVP_EXCHANGE_MAX_KEY_SIZE) ||
+		(value_size > HV_KVP_EXCHANGE_MAX_VALUE_SIZE))
+		return 1;
+
+	/*
+	 * First update the in-memory state.
+	 */
+	kvp_update_mem_state(pool);
+
+	num_records = kvp_file_info[pool].num_records;
+	record = kvp_file_info[pool].records;
+
+	for (i = 0; i < num_records; i++) {
+		if (memcmp(key, record[i].key, key_size))
+			continue;
+		/*
+		 * Found a match; just copy the value out.
+		 */
+		memcpy(value, record[i].value, value_size);
+		return 0;
+	}
+
+	return 1;
+}
+
+static int kvp_pool_enumerate(int pool, int index, __u8 *key, int key_size,
+				__u8 *value, int value_size)
+{
+	struct kvp_record *record;
+
+	/*
+	 * First update our in-memory database.
+	 */
+	kvp_update_mem_state(pool);
+	record = kvp_file_info[pool].records;
+
+	if (index >= kvp_file_info[pool].num_records) {
+		return 1;
+	}
+
+	memcpy(key, record[index].key, key_size);
+	memcpy(value, record[index].value, value_size);
+	return 0;
+}
+
+
+void kvp_get_os_info(void)
+{
+	FILE	*file;
+	char	*p, buf[512];
+
+	uname(&uts_buf);
+	os_version = uts_buf.release;
+	os_build = strdup(uts_buf.release);
+
+	os_name = uts_buf.sysname;
+	processor_arch = uts_buf.machine;
+
+	/*
+	 * The current windows host (win7) expects the build
+	 * string to be of the form: x.y.z
+	 * Strip additional information we may have.
+	 */
+	p = strchr(os_version, '-');
+	if (p)
+		*p = '\0';
+
+	/*
+	 * Parse the /etc/os-release file if present:
+	 * https://www.freedesktop.org/software/systemd/man/os-release.html
+	 */
+	file = fopen("/etc/os-release", "r");
+	if (file != NULL) {
+		while (fgets(buf, sizeof(buf), file)) {
+			char *value, *q;
+
+			/* Ignore comments */
+			if (buf[0] == '#')
+				continue;
+
+			/* Split into name=value */
+			p = strchr(buf, '=');
+			if (!p)
+				continue;
+			*p++ = 0;
+
+			/* Remove quotes and newline; un-escape */
+			value = p;
+			q = p;
+			while (*p) {
+				if (*p == '\\') {
+					++p;
+					if (!*p)
+						break;
+					*q++ = *p++;
+				} else if (*p == '\'' || *p == '"' ||
+					   *p == '\n') {
+					++p;
+				} else {
+					*q++ = *p++;
+				}
+			}
+			*q = 0;
+
+			if (!strcmp(buf, "NAME")) {
+				p = strdup(value);
+				if (!p)
+					break;
+				os_name = p;
+			} else if (!strcmp(buf, "VERSION_ID")) {
+				p = strdup(value);
+				if (!p)
+					break;
+				os_major = p;
+			}
+		}
+		fclose(file);
+		return;
+	}
+
+	/* Fallback for older RH/SUSE releases */
+	file = fopen("/etc/SuSE-release", "r");
+	if (file != NULL)
+		goto kvp_osinfo_found;
+	file  = fopen("/etc/redhat-release", "r");
+	if (file != NULL)
+		goto kvp_osinfo_found;
+
+	/*
+	 * We don't have information about the os.
+	 */
+	return;
+
+kvp_osinfo_found:
+	/* up to three lines */
+	p = fgets(buf, sizeof(buf), file);
+	if (p) {
+		p = strchr(buf, '\n');
+		if (p)
+			*p = '\0';
+		p = strdup(buf);
+		if (!p)
+			goto done;
+		os_name = p;
+
+		/* second line */
+		p = fgets(buf, sizeof(buf), file);
+		if (p) {
+			p = strchr(buf, '\n');
+			if (p)
+				*p = '\0';
+			p = strdup(buf);
+			if (!p)
+				goto done;
+			os_major = p;
+
+			/* third line */
+			p = fgets(buf, sizeof(buf), file);
+			if (p)  {
+				p = strchr(buf, '\n');
+				if (p)
+					*p = '\0';
+				p = strdup(buf);
+				if (p)
+					os_minor = p;
+			}
+		}
+	}
+
+done:
+	fclose(file);
+	return;
+}
+
+
+
+/*
+ * Retrieve an interface name corresponding to the specified guid.
+ * If there is a match, the function returns a pointer
+ * to the interface name and if not, a NULL is returned.
+ * If a match is found, the caller is responsible for
+ * freeing the memory.
+ */
+
+static char *kvp_get_if_name(char *guid)
+{
+	DIR *dir;
+	struct dirent *entry;
+	FILE    *file;
+	char    *p, *x;
+	char    *if_name = NULL;
+	char    buf[256];
+	char dev_id[PATH_MAX];
+
+	dir = opendir(KVP_NET_DIR);
+	if (dir == NULL)
+		return NULL;
+
+	while ((entry = readdir(dir)) != NULL) {
+		/*
+		 * Set the state for the next pass.
+		 */
+		snprintf(dev_id, sizeof(dev_id), "%s%s/device/device_id",
+			 KVP_NET_DIR, entry->d_name);
+
+		file = fopen(dev_id, "r");
+		if (file == NULL)
+			continue;
+
+		p = fgets(buf, sizeof(buf), file);
+		if (p) {
+			x = strchr(p, '\n');
+			if (x)
+				*x = '\0';
+
+			if (!strcmp(p, guid)) {
+				/*
+				 * Found the guid match; return the interface
+				 * name. The caller will free the memory.
+				 */
+				if_name = strdup(entry->d_name);
+				fclose(file);
+				break;
+			}
+		}
+		fclose(file);
+	}
+
+	closedir(dir);
+	return if_name;
+}
+
+/*
+ * Retrieve the MAC address given the interface name.
+ */
+
+static char *kvp_if_name_to_mac(char *if_name)
+{
+	FILE    *file;
+	char    *p, *x;
+	char    buf[256];
+	char addr_file[PATH_MAX];
+	unsigned int i;
+	char *mac_addr = NULL;
+
+	snprintf(addr_file, sizeof(addr_file), "%s%s%s", KVP_NET_DIR,
+		 if_name, "/address");
+
+	file = fopen(addr_file, "r");
+	if (file == NULL)
+		return NULL;
+
+	p = fgets(buf, sizeof(buf), file);
+	if (p) {
+		x = strchr(p, '\n');
+		if (x)
+			*x = '\0';
+		for (i = 0; i < strlen(p); i++)
+			p[i] = toupper(p[i]);
+		mac_addr = strdup(p);
+	}
+
+	fclose(file);
+	return mac_addr;
+}
+
+static void kvp_process_ipconfig_file(char *cmd,
+					char *config_buf, unsigned int len,
+					int element_size, int offset)
+{
+	char buf[256];
+	char *p;
+	char *x;
+	FILE *file;
+
+	/*
+	 * First execute the command.
+	 */
+	file = popen(cmd, "r");
+	if (file == NULL)
+		return;
+
+	if (offset == 0)
+		memset(config_buf, 0, len);
+	while ((p = fgets(buf, sizeof(buf), file)) != NULL) {
+		if (len < strlen(config_buf) + element_size + 1)
+			break;
+
+		x = strchr(p, '\n');
+		if (x)
+			*x = '\0';
+
+		strcat(config_buf, p);
+		strcat(config_buf, ";");
+	}
+	pclose(file);
+}
+
+static void kvp_get_ipconfig_info(char *if_name,
+				 struct hv_kvp_ipaddr_value *buffer)
+{
+	char cmd[512];
+	char dhcp_info[128];
+	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);
+
+
+	/*
+	 * Gather the DNS state.
+	 * Since there is no standard way to get this information
+	 * across various distributions of interest; we just invoke
+	 * an external script that needs to be ported across distros
+	 * of interest.
+	 *
+	 * Following is the expected format of the information from the script:
+	 *
+	 * ipaddr1 (nameserver1)
+	 * ipaddr2 (nameserver2)
+	 * .
+	 * .
+	 */
+
+	sprintf(cmd, KVP_SCRIPTS_PATH "%s",  "hv_get_dns_info");
+
+	/*
+	 * Execute the command to gather DNS info.
+	 */
+	kvp_process_ipconfig_file(cmd, (char *)buffer->dns_addr,
+				(MAX_IP_ADDR_SIZE * 2), INET_ADDRSTRLEN, 0);
+
+	/*
+	 * Gather the DHCP state.
+	 * We will gather this state by invoking an external script.
+	 * The parameter to the script is the interface name.
+	 * Here is the expected output:
+	 *
+	 * Enabled: DHCP enabled.
+	 */
+
+	sprintf(cmd, KVP_SCRIPTS_PATH "%s %s", "hv_get_dhcp_info", if_name);
+
+	file = popen(cmd, "r");
+	if (file == NULL)
+		return;
+
+	p = fgets(dhcp_info, sizeof(dhcp_info), file);
+	if (p == NULL) {
+		pclose(file);
+		return;
+	}
+
+	if (!strncmp(p, "Enabled", 7))
+		buffer->dhcp_enabled = 1;
+	else
+		buffer->dhcp_enabled = 0;
+
+	pclose(file);
+}
+
+
+static unsigned int hweight32(unsigned int *w)
+{
+	unsigned int res = *w - ((*w >> 1) & 0x55555555);
+	res = (res & 0x33333333) + ((res >> 2) & 0x33333333);
+	res = (res + (res >> 4)) & 0x0F0F0F0F;
+	res = res + (res >> 8);
+	return (res + (res >> 16)) & 0x000000FF;
+}
+
+static int kvp_process_ip_address(void *addrp,
+				int family, char *buffer,
+				int length,  int *offset)
+{
+	struct sockaddr_in *addr;
+	struct sockaddr_in6 *addr6;
+	int addr_length;
+	char tmp[50];
+	const char *str;
+
+	if (family == AF_INET) {
+		addr = addrp;
+		str = inet_ntop(family, &addr->sin_addr, tmp, 50);
+		addr_length = INET_ADDRSTRLEN;
+	} else {
+		addr6 = addrp;
+		str = inet_ntop(family, &addr6->sin6_addr.s6_addr, tmp, 50);
+		addr_length = INET6_ADDRSTRLEN;
+	}
+
+	if ((length - *offset) < addr_length + 2)
+		return HV_E_FAIL;
+	if (str == NULL) {
+		strcpy(buffer, "inet_ntop failed\n");
+		return HV_E_FAIL;
+	}
+	if (*offset == 0)
+		strcpy(buffer, tmp);
+	else {
+		strcat(buffer, ";");
+		strcat(buffer, tmp);
+	}
+
+	*offset += strlen(str) + 1;
+
+	return 0;
+}
+
+static int
+kvp_get_ip_info(int family, char *if_name, int op,
+		 void  *out_buffer, unsigned int length)
+{
+	struct ifaddrs *ifap;
+	struct ifaddrs *curp;
+	int offset = 0;
+	int sn_offset = 0;
+	int error = 0;
+	char *buffer;
+	struct hv_kvp_ipaddr_value *ip_buffer = NULL;
+	char cidr_mask[5]; /* /xyz */
+	int weight;
+	int i;
+	unsigned int *w;
+	char *sn_str;
+	struct sockaddr_in6 *addr6;
+
+	if (op == KVP_OP_ENUMERATE) {
+		buffer = out_buffer;
+	} else {
+		ip_buffer = out_buffer;
+		buffer = (char *)ip_buffer->ip_addr;
+		ip_buffer->addr_family = 0;
+	}
+	/*
+	 * On entry into this function, the buffer is capable of holding the
+	 * maximum key value.
+	 */
+
+	if (getifaddrs(&ifap)) {
+		strcpy(buffer, "getifaddrs failed\n");
+		return HV_E_FAIL;
+	}
+
+	curp = ifap;
+	while (curp != NULL) {
+		if (curp->ifa_addr == NULL) {
+			curp = curp->ifa_next;
+			continue;
+		}
+
+		if ((if_name != NULL) &&
+			(strncmp(curp->ifa_name, if_name, strlen(if_name)))) {
+			/*
+			 * We want info about a specific interface;
+			 * just continue.
+			 */
+			curp = curp->ifa_next;
+			continue;
+		}
+
+		/*
+		 * We only support two address families: AF_INET and AF_INET6.
+		 * If a family value of 0 is specified, we collect both
+		 * supported address families; if not we gather info on
+		 * the specified address family.
+		 */
+		if ((((family != 0) &&
+			 (curp->ifa_addr->sa_family != family))) ||
+			 (curp->ifa_flags & IFF_LOOPBACK)) {
+			curp = curp->ifa_next;
+			continue;
+		}
+		if ((curp->ifa_addr->sa_family != AF_INET) &&
+			(curp->ifa_addr->sa_family != AF_INET6)) {
+			curp = curp->ifa_next;
+			continue;
+		}
+
+		if (op == KVP_OP_GET_IP_INFO) {
+			/*
+			 * Gather info other than the IP address.
+			 * IP address info will be gathered later.
+			 */
+			if (curp->ifa_addr->sa_family == AF_INET) {
+				ip_buffer->addr_family |= ADDR_FAMILY_IPV4;
+				/*
+				 * Get subnet info.
+				 */
+				error = kvp_process_ip_address(
+							     curp->ifa_netmask,
+							     AF_INET,
+							     (char *)
+							     ip_buffer->sub_net,
+							     length,
+							     &sn_offset);
+				if (error)
+					goto gather_ipaddr;
+			} else {
+				ip_buffer->addr_family |= ADDR_FAMILY_IPV6;
+
+				/*
+				 * Get subnet info in CIDR format.
+				 */
+				weight = 0;
+				sn_str = (char *)ip_buffer->sub_net;
+				addr6 = (struct sockaddr_in6 *)
+					curp->ifa_netmask;
+				w = addr6->sin6_addr.s6_addr32;
+
+				for (i = 0; i < 4; i++)
+					weight += hweight32(&w[i]);
+
+				sprintf(cidr_mask, "/%d", weight);
+				if (length < sn_offset + strlen(cidr_mask) + 1)
+					goto gather_ipaddr;
+
+				if (sn_offset == 0)
+					strcpy(sn_str, cidr_mask);
+				else {
+					strcat((char *)ip_buffer->sub_net, ";");
+					strcat(sn_str, cidr_mask);
+				}
+				sn_offset += strlen(sn_str) + 1;
+			}
+
+			/*
+			 * Collect other ip related configuration info.
+			 */
+
+			kvp_get_ipconfig_info(if_name, ip_buffer);
+		}
+
+gather_ipaddr:
+		error = kvp_process_ip_address(curp->ifa_addr,
+						curp->ifa_addr->sa_family,
+						buffer,
+						length, &offset);
+		if (error)
+			goto getaddr_done;
+
+		curp = curp->ifa_next;
+	}
+
+getaddr_done:
+	freeifaddrs(ifap);
+	return error;
+}
+
+/*
+ * Retrieve the IP given the MAC address.
+ */
+static int kvp_mac_to_ip(struct hv_kvp_ipaddr_value *kvp_ip_val)
+{
+	char *mac = (char *)kvp_ip_val->adapter_id;
+	DIR *dir;
+	struct dirent *entry;
+	FILE    *file;
+	char    *p, *x;
+	char    *if_name = NULL;
+	char    buf[256];
+	char dev_id[PATH_MAX];
+	unsigned int i;
+	int error = HV_E_FAIL;
+
+	dir = opendir(KVP_NET_DIR);
+	if (dir == NULL)
+		return HV_E_FAIL;
+
+	while ((entry = readdir(dir)) != NULL) {
+		/*
+		 * Set the state for the next pass.
+		 */
+		snprintf(dev_id, sizeof(dev_id), "%s%s/address", KVP_NET_DIR,
+			 entry->d_name);
+
+		file = fopen(dev_id, "r");
+		if (file == NULL)
+			continue;
+
+		p = fgets(buf, sizeof(buf), file);
+		fclose(file);
+		if (!p)
+			continue;
+
+		x = strchr(p, '\n');
+		if (x)
+			*x = '\0';
+
+		for (i = 0; i < strlen(p); i++)
+			p[i] = toupper(p[i]);
+
+		if (strcmp(p, mac))
+			continue;
+
+		/*
+		 * Found the MAC match.
+		 * A NIC (e.g. VF) matching the MAC, but without IP, is skipped.
+		 */
+		if_name = entry->d_name;
+		if (!if_name)
+			continue;
+
+		error = kvp_get_ip_info(0, if_name, KVP_OP_GET_IP_INFO,
+					kvp_ip_val, MAX_IP_ADDR_SIZE * 2);
+
+		if (!error && strlen((char *)kvp_ip_val->ip_addr))
+			break;
+	}
+
+	closedir(dir);
+	return error;
+}
+
+static int expand_ipv6(char *addr, int type)
+{
+	int ret;
+	struct in6_addr v6_addr;
+
+	ret = inet_pton(AF_INET6, addr, &v6_addr);
+
+	if (ret != 1) {
+		if (type == NETMASK)
+			return 1;
+		return 0;
+	}
+
+	sprintf(addr, "%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:"
+		"%02x%02x:%02x%02x:%02x%02x",
+		(int)v6_addr.s6_addr[0], (int)v6_addr.s6_addr[1],
+		(int)v6_addr.s6_addr[2], (int)v6_addr.s6_addr[3],
+		(int)v6_addr.s6_addr[4], (int)v6_addr.s6_addr[5],
+		(int)v6_addr.s6_addr[6], (int)v6_addr.s6_addr[7],
+		(int)v6_addr.s6_addr[8], (int)v6_addr.s6_addr[9],
+		(int)v6_addr.s6_addr[10], (int)v6_addr.s6_addr[11],
+		(int)v6_addr.s6_addr[12], (int)v6_addr.s6_addr[13],
+		(int)v6_addr.s6_addr[14], (int)v6_addr.s6_addr[15]);
+
+	return 1;
+
+}
+
+static int is_ipv4(char *addr)
+{
+	int ret;
+	struct in_addr ipv4_addr;
+
+	ret = inet_pton(AF_INET, addr, &ipv4_addr);
+
+	if (ret == 1)
+		return 1;
+	return 0;
+}
+
+static int parse_ip_val_buffer(char *in_buf, int *offset,
+				char *out_buf, int out_len)
+{
+	char *x;
+	char *start;
+
+	/*
+	 * in_buf has sequence of characters that are separated by
+	 * the character ';'. The last sequence does not have the
+	 * terminating ";" character.
+	 */
+	start = in_buf + *offset;
+
+	x = strchr(start, ';');
+	if (x)
+		*x = 0;
+	else
+		x = start + strlen(start);
+
+	if (strlen(start) != 0) {
+		int i = 0;
+		/*
+		 * Get rid of leading spaces.
+		 */
+		while (start[i] == ' ')
+			i++;
+
+		if ((x - start) <= out_len) {
+			strcpy(out_buf, (start + i));
+			*offset += (x - start) + 1;
+			return 1;
+		}
+	}
+	return 0;
+}
+
+static int kvp_write_file(FILE *f, char *s1, char *s2, char *s3)
+{
+	int ret;
+
+	ret = fprintf(f, "%s%s%s%s\n", s1, s2, "=", s3);
+
+	if (ret < 0)
+		return HV_E_FAIL;
+
+	return 0;
+}
+
+
+static int process_ip_string(FILE *f, char *ip_string, int type)
+{
+	int error = 0;
+	char addr[INET6_ADDRSTRLEN];
+	int i = 0;
+	int j = 0;
+	char str[256];
+	char sub_str[13];
+	int offset = 0;
+
+	memset(addr, 0, sizeof(addr));
+
+	while (parse_ip_val_buffer(ip_string, &offset, addr,
+					(MAX_IP_ADDR_SIZE * 2))) {
+
+		sub_str[0] = 0;
+		if (is_ipv4(addr)) {
+			switch (type) {
+			case IPADDR:
+				snprintf(str, sizeof(str), "%s", "IPADDR");
+				break;
+			case NETMASK:
+				snprintf(str, sizeof(str), "%s", "NETMASK");
+				break;
+			case GATEWAY:
+				snprintf(str, sizeof(str), "%s", "GATEWAY");
+				break;
+			case DNS:
+				snprintf(str, sizeof(str), "%s", "DNS");
+				break;
+			}
+
+			if (type == DNS) {
+				snprintf(sub_str, sizeof(sub_str), "%d", ++i);
+			} else if (type == GATEWAY && i == 0) {
+				++i;
+			} else {
+				snprintf(sub_str, sizeof(sub_str), "%d", i++);
+			}
+
+
+		} else if (expand_ipv6(addr, type)) {
+			switch (type) {
+			case IPADDR:
+				snprintf(str, sizeof(str), "%s", "IPV6ADDR");
+				break;
+			case NETMASK:
+				snprintf(str, sizeof(str), "%s", "IPV6NETMASK");
+				break;
+			case GATEWAY:
+				snprintf(str, sizeof(str), "%s",
+					"IPV6_DEFAULTGW");
+				break;
+			case DNS:
+				snprintf(str, sizeof(str), "%s",  "DNS");
+				break;
+			}
+
+			if (type == DNS) {
+				snprintf(sub_str, sizeof(sub_str), "%d", ++i);
+			} else if (j == 0) {
+				++j;
+			} else {
+				snprintf(sub_str, sizeof(sub_str), "_%d", j++);
+			}
+		} else {
+			return  HV_INVALIDARG;
+		}
+
+		error = kvp_write_file(f, str, sub_str, addr);
+		if (error)
+			return error;
+		memset(addr, 0, sizeof(addr));
+	}
+
+	return 0;
+}
+
+static int kvp_set_ip_info(char *if_name, struct hv_kvp_ipaddr_value *new_val)
+{
+	int error = 0;
+	char if_file[PATH_MAX];
+	FILE *file;
+	char cmd[PATH_MAX];
+	char *mac_addr;
+	int str_len;
+
+	/*
+	 * Set the configuration for the specified interface with
+	 * the information provided. Since there is no standard
+	 * way to configure an interface, we will have an external
+	 * script that does the job of configuring the interface and
+	 * flushing the configuration.
+	 *
+	 * The parameters passed to this external script are:
+	 * 1. A configuration file that has the specified configuration.
+	 *
+	 * We will embed the name of the interface in the configuration
+	 * file: ifcfg-ethx (where ethx is the interface name).
+	 *
+	 * The information provided here may be more than what is needed
+	 * in a given distro to configure the interface and so are free
+	 * ignore information that may not be relevant.
+	 *
+	 * Here is the format of the ip configuration file:
+	 *
+	 * HWADDR=macaddr
+	 * DEVICE=interface name
+	 * BOOTPROTO=<protocol> (where <protocol> is "dhcp" if DHCP is configured
+	 *                       or "none" if no boot-time protocol should be used)
+	 *
+	 * IPADDR0=ipaddr1
+	 * IPADDR1=ipaddr2
+	 * IPADDRx=ipaddry (where y = x + 1)
+	 *
+	 * NETMASK0=netmask1
+	 * NETMASKx=netmasky (where y = x + 1)
+	 *
+	 * GATEWAY=ipaddr1
+	 * GATEWAYx=ipaddry (where y = x + 1)
+	 *
+	 * DNSx=ipaddrx (where first DNS address is tagged as DNS1 etc)
+	 *
+	 * IPV6 addresses will be tagged as IPV6ADDR, IPV6 gateway will be
+	 * tagged as IPV6_DEFAULTGW and IPV6 NETMASK will be tagged as
+	 * IPV6NETMASK.
+	 *
+	 * The host can specify multiple ipv4 and ipv6 addresses to be
+	 * configured for the interface. Furthermore, the configuration
+	 * needs to be persistent. A subsequent GET call on the interface
+	 * is expected to return the configuration that is set via the SET
+	 * call.
+	 */
+
+	snprintf(if_file, sizeof(if_file), "%s%s%s", KVP_CONFIG_LOC,
+		"/ifcfg-", if_name);
+
+	file = fopen(if_file, "w");
+
+	if (file == NULL) {
+		syslog(LOG_ERR, "Failed to open config file; error: %d %s",
+				errno, strerror(errno));
+		return HV_E_FAIL;
+	}
+
+	/*
+	 * First write out the MAC address.
+	 */
+
+	mac_addr = kvp_if_name_to_mac(if_name);
+	if (mac_addr == NULL) {
+		error = HV_E_FAIL;
+		goto setval_error;
+	}
+
+	error = kvp_write_file(file, "HWADDR", "", mac_addr);
+	free(mac_addr);
+	if (error)
+		goto setval_error;
+
+	error = kvp_write_file(file, "DEVICE", "", if_name);
+	if (error)
+		goto setval_error;
+
+	/*
+	 * The dhcp_enabled flag is only for IPv4. In the case the host only
+	 * injects an IPv6 address, the flag is true, but we still need to
+	 * proceed to parse and pass the IPv6 information to the
+	 * disto-specific script hv_set_ifconfig.
+	 */
+	if (new_val->dhcp_enabled) {
+		error = kvp_write_file(file, "BOOTPROTO", "", "dhcp");
+		if (error)
+			goto setval_error;
+
+	} else {
+		error = kvp_write_file(file, "BOOTPROTO", "", "none");
+		if (error)
+			goto setval_error;
+	}
+
+	/*
+	 * Write the configuration for ipaddress, netmask, gateway and
+	 * name servers.
+	 */
+
+	error = process_ip_string(file, (char *)new_val->ip_addr, IPADDR);
+	if (error)
+		goto setval_error;
+
+	error = process_ip_string(file, (char *)new_val->sub_net, NETMASK);
+	if (error)
+		goto setval_error;
+
+	error = process_ip_string(file, (char *)new_val->gate_way, GATEWAY);
+	if (error)
+		goto setval_error;
+
+	error = process_ip_string(file, (char *)new_val->dns_addr, DNS);
+	if (error)
+		goto setval_error;
+
+	fclose(file);
+
+	/*
+	 * Now that we have populated the configuration file,
+	 * invoke the external script to do its magic.
+	 */
+
+	str_len = snprintf(cmd, sizeof(cmd), KVP_SCRIPTS_PATH "%s %s",
+			   "hv_set_ifconfig", if_file);
+	/*
+	 * This is a little overcautious, but it's necessary to suppress some
+	 * false warnings from gcc 8.0.1.
+	 */
+	if (str_len <= 0 || (unsigned int)str_len >= sizeof(cmd)) {
+		syslog(LOG_ERR, "Cmd '%s' (len=%d) may be too long",
+		       cmd, str_len);
+		return HV_E_FAIL;
+	}
+
+	if (system(cmd)) {
+		syslog(LOG_ERR, "Failed to execute cmd '%s'; error: %d %s",
+				cmd, errno, strerror(errno));
+		return HV_E_FAIL;
+	}
+	return 0;
+
+setval_error:
+	syslog(LOG_ERR, "Failed to write config file");
+	fclose(file);
+	return error;
+}
+
+
+static void
+kvp_get_domain_name(char *buffer, int length)
+{
+	struct addrinfo	hints, *info ;
+	int error = 0;
+
+	gethostname(buffer, length);
+	memset(&hints, 0, sizeof(hints));
+	hints.ai_family = AF_INET; /*Get only ipv4 addrinfo. */
+	hints.ai_socktype = SOCK_STREAM;
+	hints.ai_flags = AI_CANONNAME;
+
+	error = getaddrinfo(buffer, NULL, &hints, &info);
+	if (error != 0) {
+		snprintf(buffer, length, "getaddrinfo failed: 0x%x %s",
+			error, gai_strerror(error));
+		return;
+	}
+	snprintf(buffer, length, "%s", info->ai_canonname);
+	freeaddrinfo(info);
+}
+
+void print_usage(char *argv[])
+{
+	fprintf(stderr, "Usage: %s [options]\n"
+		"Options are:\n"
+		"  -n, --no-daemon        stay in foreground, don't daemonize\n"
+		"  -h, --help             print this help\n", argv[0]);
+}
+
+int main(int argc, char *argv[])
+{
+	int kvp_fd = -1, len;
+	int error;
+	struct pollfd pfd;
+	char    *p;
+	struct hv_kvp_msg hv_msg[1];
+	char	*key_value;
+	char	*key_name;
+	int	op;
+	int	pool;
+	char	*if_name;
+	struct hv_kvp_ipaddr_value *kvp_ip_val;
+	int daemonize = 1, long_index = 0, opt;
+
+	static struct option long_options[] = {
+		{"help",	no_argument,	   0,  'h' },
+		{"no-daemon",	no_argument,	   0,  'n' },
+		{0,		0,		   0,  0   }
+	};
+
+	while ((opt = getopt_long(argc, argv, "hn", long_options,
+				  &long_index)) != -1) {
+		switch (opt) {
+		case 'n':
+			daemonize = 0;
+			break;
+		case 'h':
+			print_usage(argv);
+			exit(0);
+		default:
+			print_usage(argv);
+			exit(EXIT_FAILURE);
+		}
+	}
+
+	if (daemonize && daemon(1, 0))
+		return 1;
+
+	openlog("KVP", 0, LOG_USER);
+	syslog(LOG_INFO, "KVP starting; pid is:%d", getpid());
+
+	/*
+	 * Retrieve OS release information.
+	 */
+	kvp_get_os_info();
+	/*
+	 * Cache Fully Qualified Domain Name because getaddrinfo takes an
+	 * unpredictable amount of time to finish.
+	 */
+	kvp_get_domain_name(full_domain_name, sizeof(full_domain_name));
+
+	if (kvp_file_init()) {
+		syslog(LOG_ERR, "Failed to initialize the pools");
+		exit(EXIT_FAILURE);
+	}
+
+reopen_kvp_fd:
+	if (kvp_fd != -1)
+		close(kvp_fd);
+	in_hand_shake = 1;
+	kvp_fd = open("/dev/vmbus/hv_kvp", O_RDWR | O_CLOEXEC);
+
+	if (kvp_fd < 0) {
+		syslog(LOG_ERR, "open /dev/vmbus/hv_kvp failed; error: %d %s",
+		       errno, strerror(errno));
+		exit(EXIT_FAILURE);
+	}
+
+	/*
+	 * Register ourselves with the kernel.
+	 */
+	hv_msg->kvp_hdr.operation = KVP_OP_REGISTER1;
+	len = write(kvp_fd, hv_msg, sizeof(struct hv_kvp_msg));
+	if (len != sizeof(struct hv_kvp_msg)) {
+		syslog(LOG_ERR, "registration to kernel failed; error: %d %s",
+		       errno, strerror(errno));
+		close(kvp_fd);
+		exit(EXIT_FAILURE);
+	}
+
+	pfd.fd = kvp_fd;
+
+	while (1) {
+		pfd.events = POLLIN;
+		pfd.revents = 0;
+
+		if (poll(&pfd, 1, -1) < 0) {
+			syslog(LOG_ERR, "poll failed; error: %d %s", errno, strerror(errno));
+			if (errno == EINVAL) {
+				close(kvp_fd);
+				exit(EXIT_FAILURE);
+			}
+			else
+				continue;
+		}
+
+		len = read(kvp_fd, hv_msg, sizeof(struct hv_kvp_msg));
+
+		if (len != sizeof(struct hv_kvp_msg)) {
+			syslog(LOG_ERR, "read failed; error:%d %s",
+			       errno, strerror(errno));
+			goto reopen_kvp_fd;
+		}
+
+		/*
+		 * We will use the KVP header information to pass back
+		 * the error from this daemon. So, first copy the state
+		 * and set the error code to success.
+		 */
+		op = hv_msg->kvp_hdr.operation;
+		pool = hv_msg->kvp_hdr.pool;
+		hv_msg->error = HV_S_OK;
+
+		if ((in_hand_shake) && (op == KVP_OP_REGISTER1)) {
+			/*
+			 * Driver is registering with us; stash away the version
+			 * information.
+			 */
+			in_hand_shake = 0;
+			p = (char *)hv_msg->body.kvp_register.version;
+			lic_version = malloc(strlen(p) + 1);
+			if (lic_version) {
+				strcpy(lic_version, p);
+				syslog(LOG_INFO, "KVP LIC Version: %s",
+				       lic_version);
+			} else {
+				syslog(LOG_ERR, "malloc failed");
+			}
+			continue;
+		}
+
+		switch (op) {
+		case KVP_OP_GET_IP_INFO:
+			kvp_ip_val = &hv_msg->body.kvp_ip_val;
+
+			error = kvp_mac_to_ip(kvp_ip_val);
+
+			if (error)
+				hv_msg->error = error;
+
+			break;
+
+		case KVP_OP_SET_IP_INFO:
+			kvp_ip_val = &hv_msg->body.kvp_ip_val;
+			if_name = kvp_get_if_name(
+					(char *)kvp_ip_val->adapter_id);
+			if (if_name == NULL) {
+				/*
+				 * We could not map the guid to an
+				 * interface name; return error.
+				 */
+				hv_msg->error = HV_GUID_NOTFOUND;
+				break;
+			}
+			error = kvp_set_ip_info(if_name, kvp_ip_val);
+			if (error)
+				hv_msg->error = error;
+
+			free(if_name);
+			break;
+
+		case KVP_OP_SET:
+			if (kvp_key_add_or_modify(pool,
+					hv_msg->body.kvp_set.data.key,
+					hv_msg->body.kvp_set.data.key_size,
+					hv_msg->body.kvp_set.data.value,
+					hv_msg->body.kvp_set.data.value_size))
+					hv_msg->error = HV_S_CONT;
+			break;
+
+		case KVP_OP_GET:
+			if (kvp_get_value(pool,
+					hv_msg->body.kvp_set.data.key,
+					hv_msg->body.kvp_set.data.key_size,
+					hv_msg->body.kvp_set.data.value,
+					hv_msg->body.kvp_set.data.value_size))
+					hv_msg->error = HV_S_CONT;
+			break;
+
+		case KVP_OP_DELETE:
+			if (kvp_key_delete(pool,
+					hv_msg->body.kvp_delete.key,
+					hv_msg->body.kvp_delete.key_size))
+					hv_msg->error = HV_S_CONT;
+			break;
+
+		default:
+			break;
+		}
+
+		if (op != KVP_OP_ENUMERATE)
+			goto kvp_done;
+
+		/*
+		 * If the pool is KVP_POOL_AUTO, dynamically generate
+		 * both the key and the value; if not read from the
+		 * appropriate pool.
+		 */
+		if (pool != KVP_POOL_AUTO) {
+			if (kvp_pool_enumerate(pool,
+					hv_msg->body.kvp_enum_data.index,
+					hv_msg->body.kvp_enum_data.data.key,
+					HV_KVP_EXCHANGE_MAX_KEY_SIZE,
+					hv_msg->body.kvp_enum_data.data.value,
+					HV_KVP_EXCHANGE_MAX_VALUE_SIZE))
+					hv_msg->error = HV_S_CONT;
+			goto kvp_done;
+		}
+
+		key_name = (char *)hv_msg->body.kvp_enum_data.data.key;
+		key_value = (char *)hv_msg->body.kvp_enum_data.data.value;
+
+		switch (hv_msg->body.kvp_enum_data.index) {
+		case FullyQualifiedDomainName:
+			strcpy(key_value, full_domain_name);
+			strcpy(key_name, "FullyQualifiedDomainName");
+			break;
+		case IntegrationServicesVersion:
+			strcpy(key_name, "IntegrationServicesVersion");
+			strcpy(key_value, lic_version);
+			break;
+		case NetworkAddressIPv4:
+			kvp_get_ip_info(AF_INET, NULL, KVP_OP_ENUMERATE,
+				key_value, HV_KVP_EXCHANGE_MAX_VALUE_SIZE);
+			strcpy(key_name, "NetworkAddressIPv4");
+			break;
+		case NetworkAddressIPv6:
+			kvp_get_ip_info(AF_INET6, NULL, KVP_OP_ENUMERATE,
+				key_value, HV_KVP_EXCHANGE_MAX_VALUE_SIZE);
+			strcpy(key_name, "NetworkAddressIPv6");
+			break;
+		case OSBuildNumber:
+			strcpy(key_value, os_build);
+			strcpy(key_name, "OSBuildNumber");
+			break;
+		case OSName:
+			strcpy(key_value, os_name);
+			strcpy(key_name, "OSName");
+			break;
+		case OSMajorVersion:
+			strcpy(key_value, os_major);
+			strcpy(key_name, "OSMajorVersion");
+			break;
+		case OSMinorVersion:
+			strcpy(key_value, os_minor);
+			strcpy(key_name, "OSMinorVersion");
+			break;
+		case OSVersion:
+			strcpy(key_value, os_version);
+			strcpy(key_name, "OSVersion");
+			break;
+		case ProcessorArchitecture:
+			strcpy(key_value, processor_arch);
+			strcpy(key_name, "ProcessorArchitecture");
+			break;
+		default:
+			hv_msg->error = HV_S_CONT;
+			break;
+		}
+
+		/*
+		 * Send the value back to the kernel. Note: the write() may
+		 * return an error due to hibernation; we can ignore the error
+		 * by resetting the dev file, i.e. closing and re-opening it.
+		 */
+kvp_done:
+		len = write(kvp_fd, hv_msg, sizeof(struct hv_kvp_msg));
+		if (len != sizeof(struct hv_kvp_msg)) {
+			syslog(LOG_ERR, "write failed; error: %d %s", errno,
+			       strerror(errno));
+			goto reopen_kvp_fd;
+		}
+	}
+
+	close(kvp_fd);
+	exit(0);
+}