hv_kvp_daemon.c

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/*
 * An implementation of key value pair (KVP) functionality for Linux.
 *
 *
 * Copyright (C) 2010, Novell, Inc.
 * Author : K. Y. Srinivasan <[email protected]>
 *
 * 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);
        }
    }

}