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1 /* |
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2 * Copyright (C) 2005 Anthony Liguori <anthony@codemonkey.ws> |
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3 * |
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4 * Network Block Device |
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5 * |
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6 * This program is free software; you can redistribute it and/or modify |
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7 * it under the terms of the GNU General Public License as published by |
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8 * the Free Software Foundation; under version 2 of the License. |
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9 * |
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10 * This program is distributed in the hope that it will be useful, |
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11 * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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13 * GNU General Public License for more details. |
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14 * |
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15 * You should have received a copy of the GNU General Public License |
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16 * along with this program; if not, write to the Free Software |
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17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
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18 */ |
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19 |
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20 #include <qemu-common.h> |
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21 #include "block_int.h" |
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22 #include "nbd.h" |
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23 |
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24 #include <stdarg.h> |
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25 #include <stdio.h> |
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26 #include <getopt.h> |
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27 #include <err.h> |
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28 #include <sys/types.h> |
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29 #include <sys/socket.h> |
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30 #include <netinet/in.h> |
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31 #include <netinet/tcp.h> |
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32 #include <arpa/inet.h> |
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33 #include <signal.h> |
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34 |
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35 #define SOCKET_PATH "/var/lock/qemu-nbd-%s" |
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36 |
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37 #define NBD_BUFFER_SIZE (1024*1024) |
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38 |
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39 static int verbose; |
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40 |
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41 static void usage(const char *name) |
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42 { |
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43 printf( |
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44 "Usage: %s [OPTIONS] FILE\n" |
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45 "QEMU Disk Network Block Device Server\n" |
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46 "\n" |
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47 " -p, --port=PORT port to listen on (default `1024')\n" |
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48 " -o, --offset=OFFSET offset into the image\n" |
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49 " -b, --bind=IFACE interface to bind to (default `0.0.0.0')\n" |
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50 " -k, --socket=PATH path to the unix socket\n" |
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51 " (default '"SOCKET_PATH"')\n" |
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52 " -r, --read-only export read-only\n" |
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53 " -P, --partition=NUM only expose partition NUM\n" |
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54 " -s, --snapshot use snapshot file\n" |
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55 " -n, --nocache disable host cache\n" |
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56 " -c, --connect=DEV connect FILE to the local NBD device DEV\n" |
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57 " -d, --disconnect disconnect the specified device\n" |
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58 " -e, --shared=NUM device can be shared by NUM clients (default '1')\n" |
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59 " -t, --persistent don't exit on the last connection\n" |
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60 " -v, --verbose display extra debugging information\n" |
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61 " -h, --help display this help and exit\n" |
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62 " -V, --version output version information and exit\n" |
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63 "\n" |
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64 "Report bugs to <anthony@codemonkey.ws>\n" |
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65 , name, "DEVICE"); |
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66 } |
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67 |
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68 static void version(const char *name) |
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69 { |
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70 printf( |
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71 "%s version 0.0.1\n" |
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72 "Written by Anthony Liguori.\n" |
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73 "\n" |
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74 "Copyright (C) 2006 Anthony Liguori <anthony@codemonkey.ws>.\n" |
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75 "This is free software; see the source for copying conditions. There is NO\n" |
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76 "warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n" |
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77 , name); |
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78 } |
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79 |
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80 struct partition_record |
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81 { |
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82 uint8_t bootable; |
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83 uint8_t start_head; |
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84 uint32_t start_cylinder; |
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85 uint8_t start_sector; |
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86 uint8_t system; |
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87 uint8_t end_head; |
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88 uint8_t end_cylinder; |
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89 uint8_t end_sector; |
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90 uint32_t start_sector_abs; |
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91 uint32_t nb_sectors_abs; |
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92 }; |
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93 |
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94 static void read_partition(uint8_t *p, struct partition_record *r) |
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95 { |
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96 r->bootable = p[0]; |
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97 r->start_head = p[1]; |
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98 r->start_cylinder = p[3] | ((p[2] << 2) & 0x0300); |
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99 r->start_sector = p[2] & 0x3f; |
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100 r->system = p[4]; |
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101 r->end_head = p[5]; |
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102 r->end_cylinder = p[7] | ((p[6] << 2) & 0x300); |
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103 r->end_sector = p[6] & 0x3f; |
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104 r->start_sector_abs = p[8] | p[9] << 8 | p[10] << 16 | p[11] << 24; |
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105 r->nb_sectors_abs = p[12] | p[13] << 8 | p[14] << 16 | p[15] << 24; |
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106 } |
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107 |
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108 static int find_partition(BlockDriverState *bs, int partition, |
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109 off_t *offset, off_t *size) |
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110 { |
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111 struct partition_record mbr[4]; |
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112 uint8_t data[512]; |
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113 int i; |
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114 int ext_partnum = 4; |
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115 |
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116 if (bdrv_read(bs, 0, data, 1)) |
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117 errx(EINVAL, "error while reading"); |
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118 |
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119 if (data[510] != 0x55 || data[511] != 0xaa) { |
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120 errno = -EINVAL; |
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121 return -1; |
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122 } |
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123 |
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124 for (i = 0; i < 4; i++) { |
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125 read_partition(&data[446 + 16 * i], &mbr[i]); |
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126 |
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127 if (!mbr[i].nb_sectors_abs) |
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128 continue; |
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129 |
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130 if (mbr[i].system == 0xF || mbr[i].system == 0x5) { |
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131 struct partition_record ext[4]; |
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132 uint8_t data1[512]; |
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133 int j; |
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134 |
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135 if (bdrv_read(bs, mbr[i].start_sector_abs, data1, 1)) |
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136 errx(EINVAL, "error while reading"); |
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137 |
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138 for (j = 0; j < 4; j++) { |
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139 read_partition(&data1[446 + 16 * j], &ext[j]); |
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140 if (!ext[j].nb_sectors_abs) |
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141 continue; |
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142 |
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143 if ((ext_partnum + j + 1) == partition) { |
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144 *offset = (uint64_t)ext[j].start_sector_abs << 9; |
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145 *size = (uint64_t)ext[j].nb_sectors_abs << 9; |
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146 return 0; |
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147 } |
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148 } |
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149 ext_partnum += 4; |
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150 } else if ((i + 1) == partition) { |
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151 *offset = (uint64_t)mbr[i].start_sector_abs << 9; |
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152 *size = (uint64_t)mbr[i].nb_sectors_abs << 9; |
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153 return 0; |
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154 } |
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155 } |
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156 |
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157 errno = -ENOENT; |
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158 return -1; |
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159 } |
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160 |
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161 static void show_parts(const char *device) |
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162 { |
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163 if (fork() == 0) { |
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164 int nbd; |
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165 |
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166 /* linux just needs an open() to trigger |
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167 * the partition table update |
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168 * but remember to load the module with max_part != 0 : |
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169 * modprobe nbd max_part=63 |
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170 */ |
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171 nbd = open(device, O_RDWR); |
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172 if (nbd != -1) |
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173 close(nbd); |
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174 exit(0); |
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175 } |
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176 } |
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177 |
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178 int main(int argc, char **argv) |
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179 { |
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180 BlockDriverState *bs; |
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181 off_t dev_offset = 0; |
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182 off_t offset = 0; |
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183 bool readonly = false; |
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184 bool disconnect = false; |
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185 const char *bindto = "0.0.0.0"; |
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186 int port = 1024; |
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187 struct sockaddr_in addr; |
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188 socklen_t addr_len = sizeof(addr); |
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189 off_t fd_size; |
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190 char *device = NULL; |
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191 char *socket = NULL; |
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192 char sockpath[128]; |
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193 const char *sopt = "hVbo:p:rsnP:c:dvk:e:t"; |
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194 struct option lopt[] = { |
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195 { "help", 0, 0, 'h' }, |
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196 { "version", 0, 0, 'V' }, |
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197 { "bind", 1, 0, 'b' }, |
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198 { "port", 1, 0, 'p' }, |
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199 { "socket", 1, 0, 'k' }, |
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200 { "offset", 1, 0, 'o' }, |
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201 { "read-only", 0, 0, 'r' }, |
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202 { "partition", 1, 0, 'P' }, |
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203 { "connect", 1, 0, 'c' }, |
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204 { "disconnect", 0, 0, 'd' }, |
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205 { "snapshot", 0, 0, 's' }, |
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206 { "nocache", 0, 0, 'n' }, |
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207 { "shared", 1, 0, 'e' }, |
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208 { "persistent", 0, 0, 't' }, |
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209 { "verbose", 0, 0, 'v' }, |
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210 { NULL, 0, 0, 0 } |
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211 }; |
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212 int ch; |
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213 int opt_ind = 0; |
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214 int li; |
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215 char *end; |
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216 int flags = 0; |
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217 int partition = -1; |
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218 int ret; |
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219 int shared = 1; |
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220 uint8_t *data; |
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221 fd_set fds; |
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222 int *sharing_fds; |
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223 int fd; |
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224 int i; |
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225 int nb_fds = 0; |
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226 int max_fd; |
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227 int persistent = 0; |
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228 |
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229 while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) { |
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230 switch (ch) { |
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231 case 's': |
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232 flags |= BDRV_O_SNAPSHOT; |
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233 break; |
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234 case 'n': |
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235 flags |= BDRV_O_NOCACHE; |
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236 break; |
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237 case 'b': |
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238 bindto = optarg; |
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239 break; |
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240 case 'p': |
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241 li = strtol(optarg, &end, 0); |
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242 if (*end) { |
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243 errx(EINVAL, "Invalid port `%s'", optarg); |
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244 } |
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245 if (li < 1 || li > 65535) { |
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246 errx(EINVAL, "Port out of range `%s'", optarg); |
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247 } |
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248 port = (uint16_t)li; |
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249 break; |
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250 case 'o': |
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251 dev_offset = strtoll (optarg, &end, 0); |
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252 if (*end) { |
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253 errx(EINVAL, "Invalid offset `%s'", optarg); |
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254 } |
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255 if (dev_offset < 0) { |
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256 errx(EINVAL, "Offset must be positive `%s'", optarg); |
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257 } |
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258 break; |
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259 case 'r': |
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260 readonly = true; |
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261 break; |
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262 case 'P': |
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263 partition = strtol(optarg, &end, 0); |
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264 if (*end) |
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265 errx(EINVAL, "Invalid partition `%s'", optarg); |
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266 if (partition < 1 || partition > 8) |
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267 errx(EINVAL, "Invalid partition %d", partition); |
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268 break; |
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269 case 'k': |
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270 socket = optarg; |
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271 if (socket[0] != '/') |
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272 errx(EINVAL, "socket path must be absolute\n"); |
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273 break; |
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274 case 'd': |
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275 disconnect = true; |
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276 break; |
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277 case 'c': |
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278 device = optarg; |
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279 break; |
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280 case 'e': |
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281 shared = strtol(optarg, &end, 0); |
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282 if (*end) { |
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283 errx(EINVAL, "Invalid shared device number '%s'", optarg); |
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284 } |
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285 if (shared < 1) { |
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286 errx(EINVAL, "Shared device number must be greater than 0\n"); |
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287 } |
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288 break; |
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289 case 't': |
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290 persistent = 1; |
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291 break; |
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292 case 'v': |
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293 verbose = 1; |
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294 break; |
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295 case 'V': |
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296 version(argv[0]); |
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297 exit(0); |
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298 break; |
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299 case 'h': |
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300 usage(argv[0]); |
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301 exit(0); |
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302 break; |
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303 case '?': |
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304 errx(EINVAL, "Try `%s --help' for more information.", |
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305 argv[0]); |
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306 } |
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307 } |
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308 |
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309 if ((argc - optind) != 1) { |
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310 errx(EINVAL, "Invalid number of argument.\n" |
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311 "Try `%s --help' for more information.", |
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312 argv[0]); |
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313 } |
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314 |
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315 if (disconnect) { |
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316 fd = open(argv[optind], O_RDWR); |
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317 if (fd == -1) |
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318 errx(errno, "Cannot open %s", argv[optind]); |
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319 |
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320 nbd_disconnect(fd); |
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321 |
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322 close(fd); |
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323 |
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324 printf("%s disconnected\n", argv[optind]); |
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325 |
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326 return 0; |
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327 } |
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328 |
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329 bdrv_init(); |
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330 |
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331 bs = bdrv_new("hda"); |
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332 if (bs == NULL) |
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333 return 1; |
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334 |
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335 if (bdrv_open(bs, argv[optind], flags) == -1) |
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336 return 1; |
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337 |
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338 fd_size = bs->total_sectors * 512; |
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339 |
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340 if (partition != -1 && |
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341 find_partition(bs, partition, &dev_offset, &fd_size)) |
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342 errx(errno, "Could not find partition %d", partition); |
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343 |
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344 if (device) { |
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345 pid_t pid; |
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346 int sock; |
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347 |
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348 if (!verbose) |
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349 daemon(0, 0); /* detach client and server */ |
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350 |
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351 if (socket == NULL) { |
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352 sprintf(sockpath, SOCKET_PATH, basename(device)); |
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353 socket = sockpath; |
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354 } |
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355 |
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356 pid = fork(); |
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357 if (pid < 0) |
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358 return 1; |
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359 if (pid != 0) { |
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360 off_t size; |
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361 size_t blocksize; |
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362 |
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363 ret = 0; |
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364 bdrv_close(bs); |
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365 |
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366 do { |
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367 sock = unix_socket_outgoing(socket); |
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368 if (sock == -1) { |
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369 if (errno != ENOENT && errno != ECONNREFUSED) |
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370 goto out; |
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371 sleep(1); /* wait children */ |
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372 } |
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373 } while (sock == -1); |
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374 |
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375 fd = open(device, O_RDWR); |
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376 if (fd == -1) { |
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377 ret = 1; |
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378 goto out; |
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379 } |
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380 |
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381 ret = nbd_receive_negotiate(sock, &size, &blocksize); |
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382 if (ret == -1) { |
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383 ret = 1; |
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384 goto out; |
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385 } |
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386 |
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387 ret = nbd_init(fd, sock, size, blocksize); |
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388 if (ret == -1) { |
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389 ret = 1; |
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390 goto out; |
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391 } |
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392 |
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393 printf("NBD device %s is now connected to file %s\n", |
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394 device, argv[optind]); |
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395 |
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396 /* update partition table */ |
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397 |
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398 show_parts(device); |
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399 |
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400 nbd_client(fd, sock); |
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401 close(fd); |
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402 out: |
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403 kill(pid, SIGTERM); |
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404 unlink(socket); |
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405 |
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406 return ret; |
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407 } |
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408 /* children */ |
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409 } |
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410 |
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411 sharing_fds = qemu_malloc((shared + 1) * sizeof(int)); |
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412 if (sharing_fds == NULL) |
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413 errx(ENOMEM, "Cannot allocate sharing fds"); |
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414 |
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415 if (socket) { |
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416 sharing_fds[0] = unix_socket_incoming(socket); |
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417 } else { |
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418 sharing_fds[0] = tcp_socket_incoming(bindto, port); |
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419 } |
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420 |
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421 if (sharing_fds[0] == -1) |
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422 return 1; |
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423 max_fd = sharing_fds[0]; |
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424 nb_fds++; |
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425 |
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426 data = qemu_memalign(512, NBD_BUFFER_SIZE); |
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427 if (data == NULL) |
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428 errx(ENOMEM, "Cannot allocate data buffer"); |
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429 |
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430 do { |
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431 |
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432 FD_ZERO(&fds); |
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433 for (i = 0; i < nb_fds; i++) |
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434 FD_SET(sharing_fds[i], &fds); |
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435 |
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436 ret = select(max_fd + 1, &fds, NULL, NULL, NULL); |
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437 if (ret == -1) |
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438 break; |
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439 |
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440 if (FD_ISSET(sharing_fds[0], &fds)) |
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441 ret--; |
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442 for (i = 1; i < nb_fds && ret; i++) { |
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443 if (FD_ISSET(sharing_fds[i], &fds)) { |
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444 if (nbd_trip(bs, sharing_fds[i], fd_size, dev_offset, |
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445 &offset, readonly, data, NBD_BUFFER_SIZE) != 0) { |
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446 close(sharing_fds[i]); |
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447 nb_fds--; |
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448 sharing_fds[i] = sharing_fds[nb_fds]; |
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449 i--; |
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450 } |
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451 ret--; |
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452 } |
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453 } |
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454 /* new connection ? */ |
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455 if (FD_ISSET(sharing_fds[0], &fds)) { |
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456 if (nb_fds < shared + 1) { |
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457 sharing_fds[nb_fds] = accept(sharing_fds[0], |
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458 (struct sockaddr *)&addr, |
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459 &addr_len); |
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460 if (sharing_fds[nb_fds] != -1 && |
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461 nbd_negotiate(sharing_fds[nb_fds], fd_size) != -1) { |
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462 if (sharing_fds[nb_fds] > max_fd) |
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463 max_fd = sharing_fds[nb_fds]; |
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464 nb_fds++; |
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465 } |
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466 } |
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467 } |
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468 } while (persistent || nb_fds > 1); |
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469 qemu_free(data); |
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470 |
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471 close(sharing_fds[0]); |
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472 bdrv_close(bs); |
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473 qemu_free(sharing_fds); |
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474 if (socket) |
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475 unlink(socket); |
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476 |
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477 return 0; |
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478 } |