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