Re: kern/43963: libsa cd9660.c pathname lookup problem

[Wolfgang Solfrank <Wolfgang%Solfrank.net@localhost>]

The following reply was made to PR kern/43963; it has been noted by GNATS.

From: Wolfgang Solfrank <Wolfgang%Solfrank.net@localhost>
To: gnats-bugs%NetBSD.org@localhost
Cc: Izumi Tsutsui <tsutsui%ceres.dti.ne.jp@localhost>, 
kern-bug-people%netbsd.org@localhost, 
 gnats-admin%netbsd.org@localhost, netbsd-bugs%netbsd.org@localhost, 
 minoura%smtp.minoura.org@localhost
Subject: Re: kern/43963: libsa cd9660.c pathname lookup problem
Date: Wed, 13 Oct 2010 15:50:08 +0200

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 Hi again,
 
 so I looked closer at the problem.  Turns out that it's got nothing
 to do with the order of the path table entries, which is generated
 correctly by both mkisofs and makefs.
 
 The problem is that the code doesn't handle the very first entry in
 the path table, i.e. the entry for the root directory, correctly.
 The attached patch fixes this.  While here, it also fixes a minor
 bug, where the old code (would it have worked) would not allow multiple
 path separators betwween directory entries, i.e. it would not find
 i386///binary/kernel//netbsd_install_floppy.gz.
 
 As a minor nit to the original PR, the instructions in How-to-Repeat
 can't work anyway, as the 9660 boot code currently only supports
 original 9660 filenames (albeit allowing for lower/upper case conversion)
 which doesn't allow the '-' character in filenames.  You have to type
 
 boot i386/binary/kernel/netbsd_INSTALL_FLOPPY.gz
 
 to get the desired kernel (works, of course, only with the patch applied.)
 
 Ciao,
 Wolfgang
 -- 
 Wolfgang%Solfrank.net@localhost                          Wolfgang Solfrank
 
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 Index: sys/lib/libsa/cd9660.c
 ===================================================================
 RCS file: /cvsroot/src/sys/lib/libsa/cd9660.c,v
 retrieving revision 1.25
 diff -u -r1.25 cd9660.c
 --- sys/lib/libsa/cd9660.c     22 Mar 2010 16:57:54 -0000      1.25
 +++ sys/lib/libsa/cd9660.c     13 Oct 2010 13:24:42 -0000
 @@ -190,19 +190,25 @@
                goto out;
        }
  
 -      parent = 1;
        pp = (struct ptable_ent *)buf;
 -      ent = 1;
 +      /*
 +       * The first entry is always the root directory.
 +       * Since this has a special name in it, handle it separately.
 +       */
 +      parent = 1;
        bno = isonum_732(pp->block) + isonum_711(pp->extlen);
 +      pp = (struct ptable_ent *)((char *)pp + PTSIZE(pp));
 +      ent = 2;
  
        rc = ENOENT;
 -      /*
 -       * Remove extra separators
 -       */
 -      while (*path == '/')
 -              path++;
  
        while (*path) {
 +              /*
 +               * Remove extra separators
 +               */
 +              while (*path == '/')
 +                      path++;
 +
                if ((char *)pp >= (char *)buf + psize)
                        break;
                if (isonum_722(pp->parent) != parent)
 @@ -212,7 +218,7 @@
                        ent++;
                        continue;
                }
 -              path += isonum_711(pp->namlen) + 1;
 +              path += isonum_711(pp->namlen);
                parent = ent;
                bno = isonum_732(pp->block) + isonum_711(pp->extlen);
                while ((char *)pp < (char *)buf + psize) {
 
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