Re: kern/48808

["Thomas Schmitt" <scdbackup%gmx.net@localhost>]

The following reply was made to PR kern/48808; it has been noted by GNATS.

From: "Thomas Schmitt" <scdbackup%gmx.net@localhost>
To: gnats-bugs%NetBSD.org@localhost
Cc: 
Subject: Re: kern/48808
Date: Wed, 14 May 2014 11:04:44 +0200

 --- sbin/mount_cd9660/mount_cd9660.c.orig      2011-08-29 14:35:00.000000000 
+0000
 +++ sbin/mount_cd9660/mount_cd9660.c   2014-05-13 19:09:42.000000000 +0000
 @@ -59,6 +59,7 @@ __RCSID("$NetBSD: mount_cd9660.c,v 1.32 
  #include <string.h>
  #include <unistd.h>
  #include <util.h>
 +#include <errno.h>
  
  #include <isofs/cd9660/cd9660_mount.h>
  
 @@ -79,6 +80,7 @@ static const struct mntopt mopts[] = {
        { "rrip", 1, ISOFSMNT_NORRIP, 1 },
        { "joliet", 1, ISOFSMNT_NOJOLIET, 1 },
        { "rrcaseins", 0, ISOFSMNT_RRCASEINS, 1 },
 +      { "ssector", 0, 0, 1 }, /* not setable, only for info via getargs */
        MOPT_NULL,
  };
  
 @@ -102,11 +104,15 @@ mount_cd9660_parseargs(int argc, char **
        int ch, opts;
        mntoptparse_t mp;
        char *dev, *dir;
 +#ifdef ISOFSMNT_SSECTOR
 +      char *ep;
 +      long long int llnum;
 +#endif
  
        memset(args, 0, sizeof(*args));
        *mntflags = opts = 0;
        optind = optreset = 1;
 -      while ((ch = getopt(argc, argv, "egijo:r")) != -1)
 +      while ((ch = getopt(argc, argv, "egijo:rs:")) != -1)
                switch (ch) {
                case 'e':
                        /* obsolete, retained for compatibility only, use
 @@ -134,6 +140,23 @@ mount_cd9660_parseargs(int argc, char **
                         * -o norrip */
                        opts |= ISOFSMNT_NORRIP;
                        break;
 +              case 's':
 +#ifdef ISOFSMNT_SSECTOR
 +                      /* learned from mount/fattr.c : a_num() */
 +                      llnum = strtoll(optarg, &ep, 0);
 +                      if (*ep || optarg == ep || llnum < 0 ||
 +                          llnum > (long long int) 0xffffff00) {
 +                              (void)fprintf(stderr,
 +                                  "%s : unusable parameter with option -s\n",
 +                                  getprogname());
 +                              usage();
 +                      }
 +                      args->ssector = llnum;
 +                      opts |= ISOFSMNT_SSECTOR;
 +                      break;
 +#else
 +                      usage();
 +#endif
                case '?':
                default:
                        usage();
 @@ -161,6 +184,38 @@ mount_cd9660_parseargs(int argc, char **
        args->flags = opts;
  }
  
 +#ifdef ISOFSMNT_SSECTOR
 +
 +/* Inquire after mount whether the running kernel knows iso_args.ssector.
 + * This cannot be done before mount(2), because then MNT_GETARGS will yield
 + * no result. Afterwards, the size of the MNT_GETARGS reply can tell.
 + */
 +static int
 +kernel_has_args_ssector(char *canon_dir)
 +{
 +      struct iso_args args;
 +      int mntflags = MNT_GETARGS, kernel_args_size;
 +
 +      kernel_args_size = mount(MOUNT_CD9660, canon_dir, mntflags,
 +                               &args, sizeof args);
 +      if (kernel_args_size == -1) {
 +              (void)fprintf(stderr,
 +                      "%s : Error when inquiring success of option -s : %s\n",
 +                      getprogname(),
 +                      errno != 0 ? strerror(errno) : "unrecognizable error");
 +              return 0;
 +      }
 +      if (kernel_args_size < (int) (sizeof (struct old_iso_args_v_1_6) +
 +                                    sizeof (unsigned long int))) {
 +              (void)fprintf(stderr, "%s : Kernel ignored option -s\n",
 +                            getprogname());
 +              return 0;
 +      }
 +      return (1);
 +}
 +
 +#endif /* ISOFSMNT_SSECTOR */
 +
  int
  mount_cd9660(int argc, char **argv)
  {
 @@ -177,6 +232,20 @@ mount_cd9660(int argc, char **argv)
                char buf[2048];
                (void)snprintb(buf, sizeof(buf), ISOFSMNT_BITS, args.flags);
                printf("%s\n", buf);
 +
 +#ifdef ISOFSMNT_SSECTOR
 +
 +              if (args.flags & ISOFSMNT_SSECTOR)
 +                      printf("-s %lu\n", args.ssector);
 +      } else if ((args.flags & ISOFSMNT_SSECTOR) && args.ssector > 0) {
 +              if (!kernel_has_args_ssector(canon_dir)) {
 +                      if (unmount(canon_dir, 0) == 0)
 +                              (void)fprintf(stderr,
 +                         "%s : Had to revoke mount attempt with option -s\n",
 +                                      getprogname());
 +                      exit(1);
 +              }
 +#endif
        }
  
        exit(0);
 @@ -185,7 +254,13 @@ mount_cd9660(int argc, char **argv)
  static void
  usage(void)
  {
 +#ifdef ISOFSMNT_SSECTOR
 +      (void)fprintf(stderr,
 +              "usage: %s [-o options | -s block_offset] special node\n",
 +              getprogname());
 +#else
        (void)fprintf(stderr,
                "usage: %s [-o options] special node\n", getprogname());
 +#endif
        exit(1);
  }
 --- sbin/mount_cd9660/mount_cd9660.8.orig      2009-01-03 22:56:23.000000000 
+0000
 +++ sbin/mount_cd9660/mount_cd9660.8   2014-05-13 18:34:13.000000000 +0000
 @@ -57,7 +57,7 @@
  .\"
  .\"     @(#)mount_cd9660.8    8.3 (Berkeley) 3/27/94
  .\"
 -.Dd January 3, 2009
 +.Dd May, 12, 2014
  .Dt MOUNT_CD9660 8
  .Os
  .Sh NAME
 @@ -66,6 +66,7 @@
  .Sh SYNOPSIS
  .Nm
  .Op Fl o Ar options
 +.Op Fl s Ar block_offset
  .Ar special node
  .Sh DESCRIPTION
  The
 @@ -130,8 +131,35 @@ For compatibility with Solaris only.
  .It Cm rrcaseins
  Makes all lookups case-insensitive even for CD-ROMs with Rock-Ridge
  extensions (for Rock-Ridge, default is case-sensitive lookup).
 +.It Cm ssector
 +Is ignored as input option but reported by
 +.Cm getargs
 +if option
 +.Cm Fl s
 +is in effect.
  .El
  .El
 +.Bl -tag -width indent
 +.It Fl s Ar block_offset
 +Read the superblock from a block address, which is computed by adding
 +.Ar block_offset
 +to the partition offset implied by the choice of the device file.
 +With /dev/cdXd this partition offset is 0,
 +which leads to the first and oldest ISO-9660 session on the medium.
 +/dev/cdXa has the offset of the last and youngest recognized medium
 +partition.
 +Other sessions may be reached from /dev/cdXd by
 +.Fl s
 +with a
 +.Ar block_offset
 +which can be obtained from burn software for optical media.
 +The block size is 2048 bytes.
 +.Pp
 +/dev/cdX partitions are recognized from logical tracks of unformatted
 +optical media.
 +Formatted media appear as a single partition. Nevertheless they may bear
 +several ISO-9660 sessions. Refer to their ISO-9660 producer for offset info.
 +.El
  .Pp
  For compatibility with previous releases, following obsolete flags are
  still recognized: