Archipelago » qemu

/*\

 *  Copyright (C) 2005  Anthony Liguori <anthony@codemonkey.ws>

 *

 *  Network Block Device

 *

 *  This program is free software; you can redistribute it and/or modify

 *  it under the terms of the GNU General Public License as published by

 *  the Free Software Foundation; under version 2 of the License.

 *

 *  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.  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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 */

#include <qemu-common.h>

#include "block_int.h"

#include "nbd.h"

#include <malloc.h>

#include <stdarg.h>

#include <stdio.h>

#include <getopt.h>

#include <err.h>

#include <sys/socket.h>

#include <netinet/in.h>

#include <netinet/tcp.h>

#include <arpa/inet.h>

int verbose;

static void usage(const char *name)

{

    printf(

"Usage: %s [OPTIONS] FILE\n"

"QEMU Disk Network Block Device Server\n"

"\n"

"  -p, --port=PORT      port to listen on (default `1024')\n"

"  -o, --offset=OFFSET  offset into the image\n"

"  -b, --bind=IFACE     interface to bind to (default `0.0.0.0')\n"

"  -r, --read-only      export read-only\n"

"  -P, --partition=NUM  only expose partition NUM\n"

"  -v, --verbose        display extra debugging information\n"

"  -h, --help           display this help and exit\n"

"  -V, --version        output version information and exit\n"

"\n"

"Report bugs to <anthony@codemonkey.ws>\n"

    , name);

}

static void version(const char *name)

{

    printf(

"qemu-nbd version 0.0.1\n"

"Written by Anthony Liguori.\n"

"\n"

"Copyright (C) 2006 Anthony Liguori <anthony@codemonkey.ws>.\n"

"This is free software; see the source for copying conditions.  There is NO\n"

"warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n"

    );

}

struct partition_record

{

    uint8_t bootable;

    uint8_t start_head;

    uint32_t start_cylinder;

    uint8_t start_sector;

    uint8_t system;

    uint8_t end_head;

    uint8_t end_cylinder;

    uint8_t end_sector;

    uint32_t start_sector_abs;

    uint32_t nb_sectors_abs;

};

static void read_partition(uint8_t *p, struct partition_record *r)

{

    r->bootable = p[0];

    r->start_head = p[1];

    r->start_cylinder = p[3] | ((p[2] << 2) & 0x0300);

    r->start_sector = p[2] & 0x3f;

    r->system = p[4];

    r->end_head = p[5];

    r->end_cylinder = p[7] | ((p[6] << 2) & 0x300);

    r->end_sector = p[6] & 0x3f;

    r->start_sector_abs = p[8] | p[9] << 8 | p[10] << 16 | p[11] << 24;

    r->nb_sectors_abs = p[12] | p[13] << 8 | p[14] << 16 | p[15] << 24;

}

static int find_partition(BlockDriverState *bs, int partition,

                          off_t *offset, off_t *size)

{

    struct partition_record mbr[4];

    uint8_t data[512];

    int i;

    int ext_partnum = 4;

    if (bdrv_read(bs, 0, data, 1))

        errx(EINVAL, "error while reading");

    if (data[510] != 0x55 || data[511] != 0xaa) {

        errno = -EINVAL;

        return -1;

    }

    for (i = 0; i < 4; i++) {

        read_partition(&data[446 + 16 * i], &mbr[i]);

        if (!mbr[i].nb_sectors_abs)

            continue;

        if (mbr[i].system == 0xF || mbr[i].system == 0x5) {

            struct partition_record ext[4];

            uint8_t data1[512];

            int j;

            if (bdrv_read(bs, mbr[i].start_sector_abs, data1, 1))

                errx(EINVAL, "error while reading");

            for (j = 0; j < 4; j++) {

                read_partition(&data1[446 + 16 * j], &ext[j]);

                if (!ext[j].nb_sectors_abs)

                    continue;

                if ((ext_partnum + j + 1) == partition) {

                    *offset = (uint64_t)ext[j].start_sector_abs << 9;

                    *size = (uint64_t)ext[j].nb_sectors_abs << 9;

                    return 0;

                }

            }

            ext_partnum += 4;

        } else if ((i + 1) == partition) {

            *offset = (uint64_t)mbr[i].start_sector_abs << 9;

            *size = (uint64_t)mbr[i].nb_sectors_abs << 9;

            return 0;

        }

    }

    errno = -ENOENT;

    return -1;

}

int main(int argc, char **argv)

{

    BlockDriverState *bs;

    off_t dev_offset = 0;

    off_t offset = 0;

    bool readonly = false;

    const char *bindto = "0.0.0.0";

    int port = 1024;

    int sock, csock;

    struct sockaddr_in addr;

    socklen_t addr_len = sizeof(addr);

    off_t fd_size;

    const char *sopt = "hVbo:p:rsP:v";

    struct option lopt[] = {

        { "help", 0, 0, 'h' },

        { "version", 0, 0, 'V' },

        { "bind", 1, 0, 'b' },

        { "port", 1, 0, 'p' },

        { "offset", 1, 0, 'o' },

        { "read-only", 0, 0, 'r' },

        { "partition", 1, 0, 'P' },

        { "snapshot", 0, 0, 's' },

        { "verbose", 0, 0, 'v' },

    };

    int ch;

    int opt_ind = 0;

    int li;

    char *end;

    bool snapshot = false;

    int partition = -1;

    while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {

        switch (ch) {

        case 's':

            snapshot = true;

            break;

        case 'b':

            bindto = optarg;

            break;

        case 'p':

            li = strtol(optarg, &end, 0);

            if (*end) {

                errx(EINVAL, "Invalid port `%s'", optarg);

            }

            if (li < 1 || li > 65535) {

                errx(EINVAL, "Port out of range `%s'", optarg);

            }

            port = (uint16_t)li;

            break;

        case 'o':

                dev_offset = strtoll (optarg, &end, 0);

            if (*end) {

                errx(EINVAL, "Invalid offset `%s'", optarg);

            }

            if (dev_offset < 0) {

                errx(EINVAL, "Offset must be positive `%s'", optarg);

            }

            break;

        case 'r':

            readonly = true;

            break;

        case 'P':

            partition = strtol(optarg, &end, 0);

            if (*end)

                errx(EINVAL, "Invalid partition `%s'", optarg);

            if (partition < 1 || partition > 8)

                errx(EINVAL, "Invalid partition %d", partition);

            break;

        case 'v':

            verbose = 1;

            break;

        case 'V':

            version(argv[0]);

            exit(0);

            break;

        case 'h':

            usage(argv[0]);

            exit(0);

            break;

        case '?':

            errx(EINVAL, "Try `%s --help' for more information.",

                 argv[0]);

        }

    }

    if ((argc - optind) != 1) {

        errx(EINVAL, "Invalid number of argument.\n"

             "Try `%s --help' for more information.",

             argv[0]);

    }

    bdrv_init();

    bs = bdrv_new("hda");

    if (bs == NULL)

        return 1;

    if (bdrv_open(bs, argv[optind], snapshot) == -1)

        return 1;

    fd_size = bs->total_sectors * 512;

    if (partition != -1 &&

        find_partition(bs, partition, &dev_offset, &fd_size))

        errx(errno, "Could not find partition %d", partition);

    sock = tcp_socket_incoming(bindto, port);

    if (sock == -1)

        return 1;

    csock = accept(sock,

               (struct sockaddr *)&addr,

               &addr_len);

    if (csock == -1)

        return 1;

    /* new fd_size is calculated by find_partition */

    if (nbd_negotiate(bs, csock, fd_size) == -1)

        return 1;

    while (nbd_trip(bs, csock, fd_size, dev_offset, &offset, readonly) == 0);

    close(csock);

    close(sock);

    bdrv_close(bs);

    return 0;

}