/*
 * 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/types.h>
#include <sys/socket.h>
#include <sys/poll.h>
#include <sys/utsname.h>
#include <linux/types.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/connector.h>
#include <linux/hyperv.h>
#include <linux/netlink.h>
#include <ifaddrs.h>
#include <netdb.h>
#include <syslog.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <dirent.h>

/*
 * KVP protocol: The user mode component first registers with the
 * 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 char kvp_send_buffer[4096];
static char kvp_recv_buffer[4096 * 2];
static struct sockaddr_nl addr;
static int in_hand_shake = 1;

static char *os_name = "";
static char *os_major = "";
static char *os_minor = "";
static char *processor_arch;
static char *os_build;
static char *lic_version = "Unknown version";
static struct utsname uts_buf;

/*
 * The location of the interface configuration file.
 */

#define KVP_CONFIG_LOC  "/var/opt/"

#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", pool);
                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) {
                perror("fcntl");
                syslog(LOG_ERR, "Failed to release the lock pool: %d", pool);
                exit(EXIT_FAILURE);
        }
}

static void kvp_update_file(int pool)
{
        FILE *filep;
        size_t bytes_written;

        /*
         * 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, "w");
        if (!filep) {
                kvp_release_lock(pool);
                syslog(LOG_ERR, "Failed to open file, pool: %d", pool);
                exit(EXIT_FAILURE);
        }

        bytes_written = 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, "r");
        if (!filep) {
                kvp_release_lock(pool);
                syslog(LOG_ERR, "Failed to open file, pool: %d", pool);
                exit(EXIT_FAILURE);
        }
        for (;;) {
                readp = &record[records_read];
                records_read += fread(readp, sizeof(struct kvp_record),
                                        ENTRIES_PER_BLOCK * num_blocks,
                                        filep);

                if (ferror(filep)) {
                        syslog(LOG_ERR, "Failed to read file, pool: %d", 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");
                                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;
        FILE *filep;
        size_t records_read;
        char *fname;
        struct kvp_record *record;
        struct kvp_record *readp;
        int num_blocks;
        int i;
        int alloc_unit = sizeof(struct kvp_record) * ENTRIES_PER_BLOCK;

        if (access("/var/opt/hyperv", F_OK)) {
                if (mkdir("/var/opt/hyperv", S_IRUSR | S_IWUSR | S_IROTH)) {
                        syslog(LOG_ERR, " Failed to create /var/opt/hyperv");
                        exit(EXIT_FAILURE);
                }
        }

        for (i = 0; i < KVP_POOL_COUNT; i++) {
                fname = kvp_file_info[i].fname;
                records_read = 0;
                num_blocks = 1;
                sprintf(fname, "/var/opt/hyperv/.kvp_pool_%d", i);
                fd = open(fname, O_RDWR | O_CREAT, S_IRUSR | S_IWUSR | S_IROTH);

                if (fd == -1)
                        return 1;


                filep = fopen(fname, "r");
                if (!filep)
                        return 1;

                record = malloc(alloc_unit * num_blocks);
                if (record == NULL) {
                        fclose(filep);
                        return 1;
                }
                for (;;) {
                        readp = &record[records_read];
                        records_read += fread(readp, sizeof(struct kvp_record),
                                        ENTRIES_PER_BLOCK,
                                        filep);

                        if (ferror(filep)) {
                                syslog(LOG_ERR, "Failed to read file, pool: %d",
                                       i);
                                exit(EXIT_FAILURE);
                        }

                        if (!feof(filep)) {
                                /*
                                 * We have more data to read.
                                 */
                                num_blocks++;
                                record = realloc(record, alloc_unit *
                                                num_blocks);
                                if (record == NULL) {
                                        fclose(filep);
                                        return 1;
                                }
                                continue;
                        }
                        break;
                }
                kvp_file_info[i].fd = fd;
                kvp_file_info[i].num_blocks = num_blocks;
                kvp_file_info[i].records = record;
                kvp_file_info[i].num_records = records_read;
                fclose(filep);

        }

        return 0;
}

static int kvp_key_delete(int pool, __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) {
                        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, __u8 *key, int key_size, __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, __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_build = 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_build, '-');
        if (p)
                *p = '\0';

        /*
         * Parse the /etc/os-release file if present:
         * http://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, *q, *x;
        char    *if_name = NULL;
        char    buf[256];
        char *kvp_net_dir = "/sys/class/net/";
        char dev_id[256];

        dir = opendir(kvp_net_dir);
        if (dir == NULL)
                return NULL;

        snprintf(dev_id, sizeof(dev_id), "%s", kvp_net_dir);
        q = dev_id + strlen(kvp_net_dir);

        while ((entry = readdir(dir)) != NULL) {
                /*
                 * Set the state for the next pass.
                 */
                *q = '\0';
                strcat(dev_id, entry->d_name);
                strcat(dev_id, "/device/device_id");

                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[256];
        int i;
        char *mac_addr = NULL;

        snprintf(addr_file, sizeof(addr_file), "%s%s%s", "/sys/class/net/",
                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;
}


/*
 * Retrieve the interface name given tha MAC address.
 */

static char *kvp_mac_to_if_name(char *mac)
{
        DIR *dir;
        struct dirent *entry;
        FILE    *file;
        char    *p, *q, *x;
        char    *if_name = NULL;
        char    buf[256];
        char *kvp_net_dir = "/sys/class/net/";
        char dev_id[256];
        int i;

        dir = opendir(kvp_net_dir);
        if (dir == NULL)
                return NULL;

        snprintf(dev_id, sizeof(dev_id), kvp_net_dir);
        q = dev_id + strlen(kvp_net_dir);

        while ((entry = readdir(dir)) != NULL) {
                /*
                 * Set the state for the next pass.
                 */
                *q = '\0';

                strcat(dev_id, entry->d_name);
                strcat(dev_id, "/address");

                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';

                        for (i = 0; i < strlen(p); i++)
                                p[i] = toupper(p[i]);

                        if (!strcmp(p, mac)) {
                                /*
                                 * Found the MAC 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;
}


static void kvp_process_ipconfig_file(char *cmd,
                                        char *config_buf, 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');
                *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, "%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, "%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 = (struct sockaddr_in *)addrp;
                str = inet_ntop(family, &addr->sin_addr, tmp, 50);
                addr_length = INET_ADDRSTRLEN;
        } else {
                addr6 = (struct sockaddr_in6 *)addrp;
                str = inet_ntop(family, &addr6->sin6_addr.s6_addr, tmp, 50);
                addr_length = INET6_ADDRSTRLEN;
        }

        if ((length - *offset) < addr_length + 1)
                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, tmp);
        strcat(buffer, ";");

        *offset += strlen(str) + 1;
        return 0;
}

static int
kvp_get_ip_info(int family, char *if_name, int op,
                 void  *out_buffer, 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;
        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 = 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(sn_str, cidr_mask);
                                strcat((char *)ip_buffer->sub_net, ";");
                                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;
}


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 seperated 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[10];
        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 (i != 0) {
                                if (type != DNS) {
                                        snprintf(sub_str, sizeof(sub_str),
                                                "_%d", i++);
                                } else {
                                        snprintf(sub_str, sizeof(sub_str),
                                                "%d", ++i);
                                }
                        } else if (type == DNS) {
                                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 ((j != 0) || (type == DNS)) {
                                if (type != DNS) {
                                        snprintf(sub_str, sizeof(sub_str),
                                                "_%d", j++);
                                } else {
                                        snprintf(sub_str, sizeof(sub_str),
                                                "%d", ++i);
                                }
                        } else if (type == DNS) {
                                snprintf(sub_str, sizeof(sub_str),
                                        "%d", ++i);
                        }
                } 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[128];
        FILE *file;
        char cmd[512];
        char *mac_addr;

        /*
         * 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
         * IF_NAME=interface name
         * DHCP=yes (This is optional; if yes, DHCP is configured)
         *
         * IPADDR=ipaddr1
         * IPADDR_1=ipaddr2
         * IPADDR_x=ipaddry (where y = x + 1)
         *
         * NETMASK=netmask1
         * NETMASK_x=netmasky (where y = x + 1)
         *
         * GATEWAY=ipaddr1
         * GATEWAY_x=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,
                "hyperv/ifcfg-", if_name);

        file = fopen(if_file, "w");

        if (file == NULL) {
                syslog(LOG_ERR, "Failed to open config file");
                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);
        if (error)
                goto setval_error;

        error = kvp_write_file(file, "IF_NAME", "", if_name);
        if (error)
                goto setval_error;

        if (new_val->dhcp_enabled) {
                error = kvp_write_file(file, "DHCP", "", "yes");
                if (error)
                        goto setval_error;

                /*
                 * We are done!.
                 */
                goto setval_done;
        }

        /*
         * 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;

setval_done:
        free(mac_addr);
        fclose(file);

        /*
         * Now that we have populated the configuration file,
         * invoke the external script to do its magic.
         */

        snprintf(cmd, sizeof(cmd), "%s %s", "hv_set_ifconfig", if_file);
        system(cmd);
        return 0;

setval_error:
        syslog(LOG_ERR, "Failed to write config file");
        free(mac_addr);
        fclose(file);
        return error;
}


static int
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) {
                strcpy(buffer, "getaddrinfo failed\n");
                return error;
        }
        strcpy(buffer, info->ai_canonname);
        freeaddrinfo(info);
        return error;
}

static int
netlink_send(int fd, struct cn_msg *msg)
{
        struct nlmsghdr *nlh;
        unsigned int size;
        struct msghdr message;
        char buffer[64];
        struct iovec iov[2];

        size = NLMSG_SPACE(sizeof(struct cn_msg) + msg->len);

        nlh = (struct nlmsghdr *)buffer;
        nlh->nlmsg_seq = 0;
        nlh->nlmsg_pid = getpid();
        nlh->nlmsg_type = NLMSG_DONE;
        nlh->nlmsg_len = NLMSG_LENGTH(size - sizeof(*nlh));
        nlh->nlmsg_flags = 0;

        iov[0].iov_base = nlh;
        iov[0].iov_len = sizeof(*nlh);

        iov[1].iov_base = msg;
        iov[1].iov_len = size;

        memset(&message, 0, sizeof(message));
        message.msg_name = &addr;
        message.msg_namelen = sizeof(addr);
        message.msg_iov = iov;
        message.msg_iovlen = 2;

        return sendmsg(fd, &message, 0);
}

int main(void)
{
        int fd, len, sock_opt;
        int error;
        struct cn_msg *message;
        struct pollfd pfd;
        struct nlmsghdr *incoming_msg;
        struct cn_msg   *incoming_cn_msg;
        struct hv_kvp_msg *hv_msg;
        char    *p;
        char    *key_value;
        char    *key_name;
        int     op;
        int     pool;
        char    *if_name;
        struct hv_kvp_ipaddr_value *kvp_ip_val;

        daemon(1, 0);
        openlog("KVP", 0, LOG_USER);
        syslog(LOG_INFO, "KVP starting; pid is:%d", getpid());
        /*
         * Retrieve OS release information.
         */
        kvp_get_os_info();

        if (kvp_file_init()) {
                syslog(LOG_ERR, "Failed to initialize the pools");
                exit(EXIT_FAILURE);
        }

        fd = socket(AF_NETLINK, SOCK_DGRAM, NETLINK_CONNECTOR);
        if (fd < 0) {
                syslog(LOG_ERR, "netlink socket creation failed; error:%d", fd);
                exit(EXIT_FAILURE);
        }
        addr.nl_family = AF_NETLINK;
        addr.nl_pad = 0;
        addr.nl_pid = 0;
        addr.nl_groups = CN_KVP_IDX;


        error = bind(fd, (struct sockaddr *)&addr, sizeof(addr));
        if (error < 0) {
                syslog(LOG_ERR, "bind failed; error:%d", error);
                close(fd);
                exit(EXIT_FAILURE);
        }
        sock_opt = addr.nl_groups;
        setsockopt(fd, 270, 1, &sock_opt, sizeof(sock_opt));
        /*
         * Register ourselves with the kernel.
         */
        message = (struct cn_msg *)kvp_send_buffer;
        message->id.idx = CN_KVP_IDX;
        message->id.val = CN_KVP_VAL;

        hv_msg = (struct hv_kvp_msg *)message->data;
        hv_msg->kvp_hdr.operation = KVP_OP_REGISTER1;
        message->ack = 0;
        message->len = sizeof(struct hv_kvp_msg);

        len = netlink_send(fd, message);
        if (len < 0) {
                syslog(LOG_ERR, "netlink_send failed; error:%d", len);
                close(fd);
                exit(EXIT_FAILURE);
        }

        pfd.fd = fd;

        while (1) {
                struct sockaddr *addr_p = (struct sockaddr *) &addr;
                socklen_t addr_l = sizeof(addr);
                pfd.events = POLLIN;
                pfd.revents = 0;
                poll(&pfd, 1, -1);

                len = recvfrom(fd, kvp_recv_buffer, sizeof(kvp_recv_buffer), 0,
                                addr_p, &addr_l);

                if (len < 0 || addr.nl_pid) {
                        syslog(LOG_ERR, "recvfrom failed; pid:%u error:%d %s",
                                        addr.nl_pid, errno, strerror(errno));
                        close(fd);
                        return -1;
                }

                incoming_msg = (struct nlmsghdr *)kvp_recv_buffer;
                incoming_cn_msg = (struct cn_msg *)NLMSG_DATA(incoming_msg);
                hv_msg = (struct hv_kvp_msg *)incoming_cn_msg->data;

                /*
                 * 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;
                        if_name =
                        kvp_mac_to_if_name((char *)kvp_ip_val->adapter_id);

                        if (if_name == NULL) {
                                /*
                                 * We could not map the mac address to an
                                 * interface name; return error.
                                 */
                                hv_msg->error = HV_E_FAIL;
                                break;
                        }
                        error = kvp_get_ip_info(
                                                0, if_name, KVP_OP_GET_IP_INFO,
                                                kvp_ip_val,
                                                (MAX_IP_ADDR_SIZE * 2));

                        if (error)
                                hv_msg->error = error;

                        free(if_name);
                        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;
                }

                hv_msg = (struct hv_kvp_msg *)incoming_cn_msg->data;
                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:
                        kvp_get_domain_name(key_value,
                                        HV_KVP_EXCHANGE_MAX_VALUE_SIZE);
                        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_build);
                        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. The response is
                 * already in the receive buffer. Update the cn_msg header to
                 * reflect the key value that has been added to the message
                 */
kvp_done:

                incoming_cn_msg->id.idx = CN_KVP_IDX;
                incoming_cn_msg->id.val = CN_KVP_VAL;
                incoming_cn_msg->ack = 0;
                incoming_cn_msg->len = sizeof(struct hv_kvp_msg);

                len = netlink_send(fd, incoming_cn_msg);
                if (len < 0) {
                        syslog(LOG_ERR, "net_link send failed; error:%d", len);
                        exit(EXIT_FAILURE);
                }
        }

}