After looking a bit on how to get strip really working,
I'm proposing that we simple re-write a small elf strip
from scratch.  Starting with Ted's elf2aout.c I've made
a *very* quick-and-dirty version that you may destroy your
files with, if you want.

Note that it doesn't do fancy things like checking magic
numbers to assure sanity yet, so it's more of a 'concept
proposal' than anything else.  It also accepts only one
argument, which is probably just as well :-)

  -  Arne H. J.

/*
 * Copyright (c) 1995
 *	Ted Lemon (hereinafter referred to as the author)
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/* elf2elf.c */

#include <fcntl.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <limits.h>
#include <sys/types.h>
#include <sys/errno.h>
#include <machine/elf.h>
#include <a.out.h>

struct sect {
  unsigned long vaddr;
  unsigned long len;
};

int phcmp ();

void *saveRead (int file, off_t offset, int len, char *name);
void placeWrite(int file, off_t offset, int len, char *name, void *data);
extern int errno;

int main (int argc, char **argv)
{
  struct ehdr ex;
  struct phdr *ph;
  int i;
  int infile;
  unsigned long lastp;
  struct phdr **indt;
  void *segment;

  /* Check args... */
  if (argc != 2)
    {
      fprintf (stderr, "usage: dirtyelfstrip <elf executable>\n");
      exit (1);
    }

  /* Try the input file... */
  if ((infile = open (argv [1], O_RDWR)) < 0)
    {
      fprintf (stderr, "Can't open %s for read/write: %s\n",
	       argv [1], strerror (errno));
      exit (1);
    }

  /* Read the header, which is at the beginning of the file... */

  /*
  ** printf("elf header from file 0 size %x\n", sizeof ex);
  */

  i = read (infile, &ex, sizeof ex);
  if (i != sizeof ex)
    {
      fprintf (stderr, "ex: %s: %s.\n",
	       argv [1], i ? strerror (errno) : "End of file reached");
      exit (1);
    }

  /* Devalidate section headers */
  ex.shoff = 0;
  ex.shcount = 0;
  ex.shsize = 0;
  ex.shstrndx = 0;
  placeWrite (infile, 0, sizeof ex, "ex", &ex);


  /* Read the program headers... */
  /*
  ** printf("program headers from file %x size %x\n",
  **        ex.phoff, ex.phcount * sizeof (struct phdr));
  */
  lastp = ex.phoff + ex.phcount * sizeof (struct phdr);

  ph = (struct phdr *)saveRead (infile, ex.phoff,
				ex.phcount * sizeof (struct phdr), "ph");
  indt = (struct phdr **)malloc(ex.phcount * sizeof(struct phdr **));
  for (i=0; i<ex.phcount; i++) {
	indt[i] = ph+i;
  }

  qsort (indt, ex.phcount, sizeof (struct phdr **), phcmp);

  for (i = 0; i < ex.phcount; i++)
    {
      struct phdr *php = indt[i];

      /* Section types we can ignore... */
      if (php->type == PT_NULL || php->type == PT_NOTE ||
	  php->type == PT_PHDR || php->type == PT_MIPS_REGINFO)
      {
	printf("segment type %ld ignored file %lx size %lx\n",
		php->type, php->offset, php->filesz);
	continue;
      }
      /* Section types we can't handle... */
      else if (php->type != PT_LOAD)
        {
	  fprintf (stderr, "Program header %d type %ld can't be converted.\n",
			php-ph, php->type);
	  exit (1);
	}

	/*
	** printf("segment %d load file %x size %x end %x\n",
	**	php-ph,
	**	php->offset, php->filesz, php->offset + php->filesz);
	*/
	if ((php->offset - lastp) > 0x2000) {
		int pg;

		pg = ((php->offset - lastp) / 0x2000);
		pg *= 0x2000;

  		segment = saveRead (infile, php->offset,
					php->filesz, "segment");
		php->offset -= pg;
  		placeWrite (infile, php->offset,
  					php->filesz, "segment", segment);
		/*
		** printf("Move segment %d shift %x to %x\n", 
		**	php-ph, pg, php->offset);
		*/
	}
	lastp = php->offset + php->filesz;
     }
  placeWrite (infile, ex.phoff, ex.phcount * sizeof (struct phdr), "ph", ph);
  ftruncate(infile, lastp);

  /* Looks like we won... */
  exit (0);
}

int
phcmp (h1, h2)
     struct phdr **h1, **h2;
{
  if ((*h1) -> offset > (*h2) -> offset)
    return 1;
  else if ((*h1) -> offset < (*h2) -> offset)
    return -1;
  else
    return 0;
}

void *
saveRead (int file, off_t offset, int len, char *name)
{
  void *tmp;
  int count;
  off_t off;
  if ((off = lseek (file, offset, SEEK_SET)) < 0)
    {
      fprintf (stderr, "%s: fseek: %s\n", name, strerror (errno));
      exit (1);
    }
  if (!(tmp = malloc (len)))
    {
      fprintf (stderr, "%s: Can't allocate %d bytes.\n", name, len);
      exit (1);
    }
  count = read (file, tmp, len);
  if (count != len)
    {
      fprintf (stderr, "%s: read: %s.\n",
	       name, count ? strerror (errno) : "End of file reached");
      exit (1);
    }
  return tmp;
}

void
placeWrite (int file, off_t offset, int len, char *name, void *data)
{
  int count;
  off_t off;
  if ((off = lseek (file, offset, SEEK_SET)) < 0)
    {
      fprintf (stderr, "%s: lseek: %s\n", name, strerror (errno));
      exit (1);
    }
  count = write (file, data, len);
  if (count != len)
    {
      fprintf (stderr, "%s: write: %s.\n", name, strerror (errno));
      exit (1);
    }
}