disk-utils/raw.c

   1 /*
   2  * raw.c: User mode tool to bind and query raw character devices.
   3  *
   4  * Stephen Tweedie, 1999, 2000
   5  *
   6  * This file may be redistributed under the terms of the GNU General
   7  * Public License, version 2.
   8  *
   9  * Copyright Red Hat Software, 1999, 2000
  10  *
  11  */
  12
  13 #include <errno.h>
  14 #include <fcntl.h>
  15 #include <getopt.h>
  16 #include <linux/major.h>
  17 #include <linux/raw.h>
  18 #include <stdio.h>
  19 #include <stdlib.h>
  20 #include <string.h>
  21 #include <sys/ioctl.h>
  22 #include <sys/stat.h>
  23 #include <unistd.h>
  24
  25 #include "c.h"
  26 #include "closestream.h"
  27 #include "nls.h"
  28 #include "pathnames.h"
  29
  30 #define EXIT_RAW_ACCESS 3
  31 #define EXIT_RAW_IOCTL 4
  32
  33 #define RAW_NR_MINORS 8192
  34
  35 static int do_query;
  36 static int do_query_all;
  37
  38 static int master_fd;
  39 static int raw_minor;
  40
  41 void open_raw_ctl(void);
  42 static int query(int minor_raw, const char *raw_name, int quiet);
  43 static int bind(int minor_raw, int block_major, int block_minor);
  44
  45 static void __attribute__((__noreturn__)) usage(void)
  46 {
  47         FILE *out = stdout;
  48         fputs(USAGE_HEADER, out);
  49         fprintf(out,
  50                 _(" %1$s %2$srawN <major> <minor>\n"
  51                   " %1$s %2$srawN /dev/<blockdevice>\n"
  52                   " %1$s -q %2$srawN\n"
  53                   " %1$s -qa\n"), program_invocation_short_name,
  54                 _PATH_RAWDEVDIR);
  55
  56         fputs(USAGE_SEPARATOR, out);
  57         fputs(_("Bind a raw character device to a block device.\n"), out);
  58
  59         fputs(USAGE_OPTIONS, out);
  60         fputs(_(" -q, --query    set query mode\n"), out);
  61         fputs(_(" -a, --all      query all raw devices\n"), out);
  62         printf(USAGE_HELP_OPTIONS(16));
  63         printf(USAGE_MAN_TAIL("raw(8)"));
  64         exit(EXIT_SUCCESS);
  65 }
  66
  67 static long strtol_octal_or_err(const char *str, const char *errmesg)
  68 {
  69         long num;
  70         char *end = NULL;
  71
  72         if (str == NULL || *str == '\0')
  73                 goto err;
  74         errno = 0;
  75         num = strtol(str, &end, 0);
  76
  77         if (errno || str == end || (end && *end))
  78                 goto err;
  79
  80         return num;
  81  err:
  82         if (errno)
  83                 err(EXIT_FAILURE, "%s: '%s'", errmesg, str);
  84         else
  85                 errx(EXIT_FAILURE, "%s: '%s'", errmesg, str);
  86         return 0;
  87 }
  88
  89 int main(int argc, char *argv[])
  90 {
  91         int c;
  92         char *raw_name;
  93         char *block_name;
  94         int retval;
  95         int block_major, block_minor;
  96         int i, rc;
  97
  98         struct stat statbuf;
  99
 100         static const struct option longopts[] = {
 101                 {"query",   no_argument, NULL, 'q'},
 102                 {"all",     no_argument, NULL, 'a'},
 103                 {"version", no_argument, NULL, 'V'},
 104                 {"help",    no_argument, NULL, 'h'},
 105                 {NULL, 0, NULL, '0'},
 106         };
 107
 108         setlocale(LC_ALL, "");
 109         bindtextdomain(PACKAGE, LOCALEDIR);
 110         textdomain(PACKAGE);
 111         close_stdout_atexit();
 112
 113         while ((c = getopt_long(argc, argv, "qaVh", longopts, NULL)) != -1)
 114                 switch (c) {
 115                 case 'q':
 116                         do_query = 1;
 117                         break;
 118                 case 'a':
 119                         do_query_all = 1;
 120                         break;
 121                 case 'V':
 122                         print_version(EXIT_SUCCESS);
 123                 case 'h':
 124                         usage();
 125                 default:
 126                         errtryhelp(EXIT_FAILURE);
 127                 }
 128
 129         /*
 130          * Check for, and open, the master raw device, /dev/raw
 131          */
 132         open_raw_ctl();
 133
 134         if (do_query_all) {
 135                 if (optind < argc) {
 136                         warnx(_("bad usage"));
 137                         errtryhelp(EXIT_FAILURE);
 138                 }
 139                 for (i = 1; i < RAW_NR_MINORS; i++)
 140                         query(i, NULL, 1);
 141                 exit(EXIT_SUCCESS);
 142         }
 143
 144         /*
 145          * It's a bind or a single query.  Either way we need a raw device.
 146          */
 147
 148         if (optind >= argc) {
 149                 warnx(_("bad usage"));
 150                 errtryhelp(EXIT_FAILURE);
 151         }
 152         raw_name = argv[optind++];
 153
 154         /*
 155          * try to check the device name before stat(), because on systems with
 156          * udev the raw0 causes a create udev event for char 162/0, which
 157          * causes udev to *remove* /dev/rawctl
 158          */
 159         rc = sscanf(raw_name, _PATH_RAWDEVDIR "raw%d", &raw_minor);
 160         if (rc != 1) {
 161                 warnx(_("bad usage"));
 162                 errtryhelp(EXIT_FAILURE);
 163         }
 164         if (raw_minor == 0)
 165                 errx(EXIT_RAW_ACCESS,
 166                      _("Device '%s' is the control raw device "
 167                        "(use raw<N> where <N> is greater than zero)"),
 168                      raw_name);
 169
 170         if (do_query)
 171                 return query(raw_minor, raw_name, 0);
 172
 173         /*
 174          * It's not a query, so we still have some parsing to do.  Have we been
 175          * given a block device filename or a major/minor pair?
 176          */
 177         switch (argc - optind) {
 178         case 1:
 179                 block_name = argv[optind];
 180                 retval = stat(block_name, &statbuf);
 181                 if (retval)
 182                         err(EXIT_RAW_ACCESS,
 183                             _("Cannot locate block device '%s'"), block_name);
 184                 if (!S_ISBLK(statbuf.st_mode))
 185                         errx(EXIT_RAW_ACCESS,
 186                              _("Device '%s' is not a block device"),
 187                              block_name);
 188                 block_major = major(statbuf.st_rdev);
 189                 block_minor = minor(statbuf.st_rdev);
 190                 break;
 191
 192         case 2:
 193                 block_major =
 194                     strtol_octal_or_err(argv[optind],
 195                                         _("failed to parse argument"));
 196                 block_minor =
 197                     strtol_octal_or_err(argv[optind + 1],
 198                                         _("failed to parse argument"));
 199                 break;
 200
 201         default:
 202                 warnx(_("bad usage"));
 203                 errtryhelp(EXIT_FAILURE);
 204         }
 205
 206         return bind(raw_minor, block_major, block_minor);
 207 }
 208
 209 void open_raw_ctl(void)
 210 {
 211         master_fd = open(_PATH_RAWDEVCTL, O_RDWR, 0);
 212         if (master_fd < 0) {
 213                 master_fd = open(_PATH_RAWDEVCTL_OLD, O_RDWR, 0);
 214                 if (master_fd < 0)
 215                         err(EXIT_RAW_ACCESS,
 216                             _("Cannot open master raw device '%s'"),
 217                             _PATH_RAWDEVCTL);
 218         }
 219 }
 220
 221 static int query(int minor_raw, const char *raw_name, int quiet)
 222 {
 223         struct raw_config_request rq;
 224         static int has_worked = 0;
 225
 226         if (raw_name) {
 227                 struct stat statbuf;
 228
 229                 if (stat(raw_name, &statbuf) != 0)
 230                         err(EXIT_RAW_ACCESS,
 231                             _("Cannot locate raw device '%s'"), raw_name);
 232                 if (!S_ISCHR(statbuf.st_mode))
 233                         errx(EXIT_RAW_ACCESS,
 234                              _("Raw device '%s' is not a character dev"),
 235                              raw_name);
 236                 if (major(statbuf.st_rdev) != RAW_MAJOR)
 237                         errx(EXIT_RAW_ACCESS,
 238                              _("Device '%s' is not a raw dev"), raw_name);
 239                 minor_raw = minor(statbuf.st_rdev);
 240         }
 241
 242         rq.raw_minor = minor_raw;
 243         if (ioctl(master_fd, RAW_GETBIND, &rq) < 0) {
 244                 if (quiet && errno == ENODEV)
 245                         return 3;
 246                 if (has_worked && errno == EINVAL)
 247                         return 0;
 248                 err(EXIT_RAW_IOCTL, _("Error querying raw device"));
 249         }
 250
 251         /* If one query has worked, mark that fact so that we don't report
 252          * spurious fatal errors if raw(8) has been built to support more raw
 253          * minor numbers than the kernel has. */
 254         has_worked = 1;
 255         if (quiet && !rq.block_major && !rq.block_minor)
 256                 return 0;
 257         printf(_("%sraw%d:  bound to major %d, minor %d\n"),
 258                _PATH_RAWDEVDIR, minor_raw, (int)rq.block_major,
 259                (int)rq.block_minor);
 260         return 0;
 261 }
 262
 263 static int bind(int minor_raw, int block_major, int block_minor)
 264 {
 265         struct raw_config_request rq;
 266
 267         rq.raw_minor = minor_raw;
 268         rq.block_major = block_major;
 269         rq.block_minor = block_minor;
 270         if (ioctl(master_fd, RAW_SETBIND, &rq) < 0)
 271                 err(EXIT_RAW_IOCTL, _("Error setting raw device"));
 272         printf(_("%sraw%d:  bound to major %d, minor %d\n"),
 273                _PATH_RAWDEVDIR, raw_minor, (int)rq.block_major,
 274                (int)rq.block_minor);
 275         return 0;
 276 }