| /* |
| * 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, see <http://www.gnu.org/licenses/>. |
| */ |
| |
| #include <qemu-common.h> |
| #include "block_int.h" |
| #include "nbd.h" |
| |
| #include <stdarg.h> |
| #include <stdio.h> |
| #include <getopt.h> |
| #include <err.h> |
| #include <sys/types.h> |
| #include <sys/socket.h> |
| #include <netinet/in.h> |
| #include <netinet/tcp.h> |
| #include <arpa/inet.h> |
| #include <signal.h> |
| #include <libgen.h> |
| |
| #define SOCKET_PATH "/var/lock/qemu-nbd-%s" |
| |
| #define NBD_BUFFER_SIZE (1024*1024) |
| |
| static 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 `%d')\n" |
| " -o, --offset=OFFSET offset into the image\n" |
| " -b, --bind=IFACE interface to bind to (default `0.0.0.0')\n" |
| " -k, --socket=PATH path to the unix socket\n" |
| " (default '"SOCKET_PATH"')\n" |
| " -r, --read-only export read-only\n" |
| " -P, --partition=NUM only expose partition NUM\n" |
| " -s, --snapshot use snapshot file\n" |
| " -n, --nocache disable host cache\n" |
| " -c, --connect=DEV connect FILE to the local NBD device DEV\n" |
| " -d, --disconnect disconnect the specified device\n" |
| " -e, --shared=NUM device can be shared by NUM clients (default '1')\n" |
| " -t, --persistent don't exit on the last connection\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, NBD_DEFAULT_PORT, "DEVICE"); |
| } |
| |
| static void version(const char *name) |
| { |
| printf( |
| "%s 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" |
| , name); |
| } |
| |
| 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; |
| int ret; |
| |
| if ((ret = bdrv_read(bs, 0, data, 1)) < 0) { |
| errno = -ret; |
| err(EXIT_FAILURE, "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 ((ret = bdrv_read(bs, mbr[i].start_sector_abs, data1, 1)) < 0) { |
| errno = -ret; |
| err(EXIT_FAILURE, "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; |
| } |
| |
| static void show_parts(const char *device) |
| { |
| if (fork() == 0) { |
| int nbd; |
| |
| /* linux just needs an open() to trigger |
| * the partition table update |
| * but remember to load the module with max_part != 0 : |
| * modprobe nbd max_part=63 |
| */ |
| nbd = open(device, O_RDWR); |
| if (nbd != -1) |
| close(nbd); |
| exit(0); |
| } |
| } |
| |
| int main(int argc, char **argv) |
| { |
| BlockDriverState *bs; |
| off_t dev_offset = 0; |
| off_t offset = 0; |
| bool readonly = false; |
| bool disconnect = false; |
| const char *bindto = "0.0.0.0"; |
| int port = NBD_DEFAULT_PORT; |
| struct sockaddr_in addr; |
| socklen_t addr_len = sizeof(addr); |
| off_t fd_size; |
| char *device = NULL; |
| char *socket = NULL; |
| char sockpath[128]; |
| const char *sopt = "hVb:o:p:rsnP:c:dvk:e:t"; |
| struct option lopt[] = { |
| { "help", 0, NULL, 'h' }, |
| { "version", 0, NULL, 'V' }, |
| { "bind", 1, NULL, 'b' }, |
| { "port", 1, NULL, 'p' }, |
| { "socket", 1, NULL, 'k' }, |
| { "offset", 1, NULL, 'o' }, |
| { "read-only", 0, NULL, 'r' }, |
| { "partition", 1, NULL, 'P' }, |
| { "connect", 1, NULL, 'c' }, |
| { "disconnect", 0, NULL, 'd' }, |
| { "snapshot", 0, NULL, 's' }, |
| { "nocache", 0, NULL, 'n' }, |
| { "shared", 1, NULL, 'e' }, |
| { "persistent", 0, NULL, 't' }, |
| { "verbose", 0, NULL, 'v' }, |
| { NULL, 0, NULL, 0 } |
| }; |
| int ch; |
| int opt_ind = 0; |
| int li; |
| char *end; |
| int flags = BDRV_O_RDWR; |
| int partition = -1; |
| int ret; |
| int shared = 1; |
| uint8_t *data; |
| fd_set fds; |
| int *sharing_fds; |
| int fd; |
| int i; |
| int nb_fds = 0; |
| int max_fd; |
| int persistent = 0; |
| uint32_t nbdflags; |
| |
| while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) { |
| switch (ch) { |
| case 's': |
| flags |= BDRV_O_SNAPSHOT; |
| break; |
| case 'n': |
| flags |= BDRV_O_NOCACHE | BDRV_O_CACHE_WB; |
| break; |
| case 'b': |
| bindto = optarg; |
| break; |
| case 'p': |
| li = strtol(optarg, &end, 0); |
| if (*end) { |
| errx(EXIT_FAILURE, "Invalid port `%s'", optarg); |
| } |
| if (li < 1 || li > 65535) { |
| errx(EXIT_FAILURE, "Port out of range `%s'", optarg); |
| } |
| port = (uint16_t)li; |
| break; |
| case 'o': |
| dev_offset = strtoll (optarg, &end, 0); |
| if (*end) { |
| errx(EXIT_FAILURE, "Invalid offset `%s'", optarg); |
| } |
| if (dev_offset < 0) { |
| errx(EXIT_FAILURE, "Offset must be positive `%s'", optarg); |
| } |
| break; |
| case 'r': |
| readonly = true; |
| flags &= ~BDRV_O_RDWR; |
| break; |
| case 'P': |
| partition = strtol(optarg, &end, 0); |
| if (*end) |
| errx(EXIT_FAILURE, "Invalid partition `%s'", optarg); |
| if (partition < 1 || partition > 8) |
| errx(EXIT_FAILURE, "Invalid partition %d", partition); |
| break; |
| case 'k': |
| socket = optarg; |
| if (socket[0] != '/') |
| errx(EXIT_FAILURE, "socket path must be absolute\n"); |
| break; |
| case 'd': |
| disconnect = true; |
| break; |
| case 'c': |
| device = optarg; |
| break; |
| case 'e': |
| shared = strtol(optarg, &end, 0); |
| if (*end) { |
| errx(EXIT_FAILURE, "Invalid shared device number '%s'", optarg); |
| } |
| if (shared < 1) { |
| errx(EXIT_FAILURE, "Shared device number must be greater than 0\n"); |
| } |
| break; |
| case 't': |
| persistent = 1; |
| break; |
| case 'v': |
| verbose = 1; |
| break; |
| case 'V': |
| version(argv[0]); |
| exit(0); |
| break; |
| case 'h': |
| usage(argv[0]); |
| exit(0); |
| break; |
| case '?': |
| errx(EXIT_FAILURE, "Try `%s --help' for more information.", |
| argv[0]); |
| } |
| } |
| |
| if ((argc - optind) != 1) { |
| errx(EXIT_FAILURE, "Invalid number of argument.\n" |
| "Try `%s --help' for more information.", |
| argv[0]); |
| } |
| |
| if (disconnect) { |
| fd = open(argv[optind], O_RDWR); |
| if (fd == -1) |
| err(EXIT_FAILURE, "Cannot open %s", argv[optind]); |
| |
| nbd_disconnect(fd); |
| |
| close(fd); |
| |
| printf("%s disconnected\n", argv[optind]); |
| |
| return 0; |
| } |
| |
| bdrv_init(); |
| |
| bs = bdrv_new("hda"); |
| |
| if ((ret = bdrv_open(bs, argv[optind], flags, NULL)) < 0) { |
| errno = -ret; |
| err(EXIT_FAILURE, "Failed to bdrv_open '%s'", argv[optind]); |
| } |
| |
| fd_size = bs->total_sectors * 512; |
| |
| if (partition != -1 && |
| find_partition(bs, partition, &dev_offset, &fd_size)) |
| err(EXIT_FAILURE, "Could not find partition %d", partition); |
| |
| if (device) { |
| pid_t pid; |
| int sock; |
| |
| /* want to fail before daemonizing */ |
| if (access(device, R_OK|W_OK) == -1) { |
| err(EXIT_FAILURE, "Could not access '%s'", device); |
| } |
| |
| if (!verbose) { |
| /* detach client and server */ |
| if (qemu_daemon(0, 0) == -1) { |
| err(EXIT_FAILURE, "Failed to daemonize"); |
| } |
| } |
| |
| if (socket == NULL) { |
| snprintf(sockpath, sizeof(sockpath), SOCKET_PATH, |
| basename(device)); |
| socket = sockpath; |
| } |
| |
| pid = fork(); |
| if (pid < 0) |
| return 1; |
| if (pid != 0) { |
| off_t size; |
| size_t blocksize; |
| |
| ret = 0; |
| bdrv_close(bs); |
| |
| do { |
| sock = unix_socket_outgoing(socket); |
| if (sock == -1) { |
| if (errno != ENOENT && errno != ECONNREFUSED) { |
| ret = 1; |
| goto out; |
| } |
| sleep(1); /* wait children */ |
| } |
| } while (sock == -1); |
| |
| fd = open(device, O_RDWR); |
| if (fd == -1) { |
| ret = 1; |
| goto out; |
| } |
| |
| ret = nbd_receive_negotiate(sock, NULL, &nbdflags, |
| &size, &blocksize); |
| if (ret == -1) { |
| ret = 1; |
| goto out; |
| } |
| |
| ret = nbd_init(fd, sock, size, blocksize); |
| if (ret == -1) { |
| ret = 1; |
| goto out; |
| } |
| |
| printf("NBD device %s is now connected to file %s\n", |
| device, argv[optind]); |
| |
| /* update partition table */ |
| |
| show_parts(device); |
| |
| ret = nbd_client(fd); |
| if (ret) { |
| ret = 1; |
| } |
| close(fd); |
| out: |
| kill(pid, SIGTERM); |
| unlink(socket); |
| |
| return ret; |
| } |
| /* children */ |
| } |
| |
| sharing_fds = qemu_malloc((shared + 1) * sizeof(int)); |
| |
| if (socket) { |
| sharing_fds[0] = unix_socket_incoming(socket); |
| } else { |
| sharing_fds[0] = tcp_socket_incoming(bindto, port); |
| } |
| |
| if (sharing_fds[0] == -1) |
| return 1; |
| max_fd = sharing_fds[0]; |
| nb_fds++; |
| |
| data = qemu_blockalign(bs, NBD_BUFFER_SIZE); |
| if (data == NULL) |
| errx(EXIT_FAILURE, "Cannot allocate data buffer"); |
| |
| do { |
| |
| FD_ZERO(&fds); |
| for (i = 0; i < nb_fds; i++) |
| FD_SET(sharing_fds[i], &fds); |
| |
| ret = select(max_fd + 1, &fds, NULL, NULL, NULL); |
| if (ret == -1) |
| break; |
| |
| if (FD_ISSET(sharing_fds[0], &fds)) |
| ret--; |
| for (i = 1; i < nb_fds && ret; i++) { |
| if (FD_ISSET(sharing_fds[i], &fds)) { |
| if (nbd_trip(bs, sharing_fds[i], fd_size, dev_offset, |
| &offset, readonly, data, NBD_BUFFER_SIZE) != 0) { |
| close(sharing_fds[i]); |
| nb_fds--; |
| sharing_fds[i] = sharing_fds[nb_fds]; |
| i--; |
| } |
| ret--; |
| } |
| } |
| /* new connection ? */ |
| if (FD_ISSET(sharing_fds[0], &fds)) { |
| if (nb_fds < shared + 1) { |
| sharing_fds[nb_fds] = accept(sharing_fds[0], |
| (struct sockaddr *)&addr, |
| &addr_len); |
| if (sharing_fds[nb_fds] != -1 && |
| nbd_negotiate(sharing_fds[nb_fds], fd_size) != -1) { |
| if (sharing_fds[nb_fds] > max_fd) |
| max_fd = sharing_fds[nb_fds]; |
| nb_fds++; |
| } |
| } |
| } |
| } while (persistent || nb_fds > 1); |
| qemu_vfree(data); |
| |
| close(sharing_fds[0]); |
| bdrv_close(bs); |
| qemu_free(sharing_fds); |
| if (socket) |
| unlink(socket); |
| |
| return 0; |
| } |
