src/vppinfra/test_elf.c

/*
 * Copyright (c) 2015 Cisco and/or its affiliates.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at:
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
  Copyright (c) 2008 Eliot Dresselhaus

  Permission is hereby granted, free of charge, to any person obtaining
  a copy of this software and associated documentation files (the
  "Software"), to deal in the Software without restriction, including
  without limitation the rights to use, copy, modify, merge, publish,
  distribute, sublicense, and/or sell copies of the Software, and to
  permit persons to whom the Software is furnished to do so, subject to
  the following conditions:

  The above copyright notice and this permission notice shall be
  included in all copies or substantial portions of the Software.

  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/

#include <vppinfra/elf.h>

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>

#ifndef CLIB_UNIX
#error "unix only"
#endif

static clib_error_t *
elf_set_interpreter (elf_main_t * em, char *interp)
{
  elf_segment_t *g;
  elf_section_t *s;
  clib_error_t *error;

  vec_foreach (g, em->segments)
  {
    if (g->header.type == ELF_SEGMENT_INTERP)
      break;
  }

  if (g >= vec_end (em->segments))
    return clib_error_return (0, "interpreter not found");

  if (g->header.memory_size < 1 + strlen (interp))
    return clib_error_return (0,
			      "given interpreter does not fit; must be less than %d bytes (`%s' given)",
			      g->header.memory_size, interp);

  error =
    elf_get_section_by_start_address (em, g->header.virtual_address, &s);
  if (error)
    return error;

  /* Put in new null terminated string. */
  memset (s->contents, 0, vec_len (s->contents));
  clib_memcpy (s->contents, interp, strlen (interp));

  return 0;
}

static void
delete_dynamic_rpath_entries_from_section (elf_main_t * em, elf_section_t * s)
{
  elf64_dynamic_entry_t *e;
  elf64_dynamic_entry_t *new_es = 0;

  vec_foreach (e, em->dynamic_entries)
  {
    switch (e->type)
      {
      case ELF_DYNAMIC_ENTRY_RPATH:
      case ELF_DYNAMIC_ENTRY_RUN_PATH:
	break;

      default:
	vec_add1 (new_es, e[0]);
	break;
      }
  }

  /* Pad so as to keep section size constant. */
  {
    elf64_dynamic_entry_t e_end;
    e_end.type = ELF_DYNAMIC_ENTRY_END;
    e_end.data = 0;
    while (vec_len (new_es) < vec_len (em->dynamic_entries))
      vec_add1 (new_es, e_end);
  }

  elf_set_dynamic_entries (em);
}

static void
elf_delete_dynamic_rpath_entries (elf_main_t * em)
{
  elf_section_t *s;

  vec_foreach (s, em->sections)
  {
    switch (s->header.type)
      {
      case ELF_SECTION_DYNAMIC:
	delete_dynamic_rpath_entries_from_section (em, s);
	break;

      default:
	break;
      }
  }
}

typedef struct
{
  elf_main_t elf_main;
  char *input_file;
  char *output_file;
  char *set_interpreter;
  int verbose;
} elf_test_main_t;

int
main (int argc, char *argv[])
{
  elf_test_main_t _tm, *tm = &_tm;
  elf_main_t *em = &tm->elf_main;
  unformat_input_t i;
  clib_error_t *error = 0;

  memset (tm, 0, sizeof (tm[0]));

  unformat_init_command_line (&i, argv);
  while (unformat_check_input (&i) != UNFORMAT_END_OF_INPUT)
    {
      if (unformat (&i, "in %s", &tm->input_file))
	;
      else if (unformat (&i, "out %s", &tm->output_file))
	;
      else if (unformat (&i, "set-interpreter %s", &tm->set_interpreter))
	;
      else if (unformat (&i, "verbose"))
	tm->verbose = ~0;
      else if (unformat (&i, "verbose-symbols"))
	tm->verbose |= FORMAT_ELF_MAIN_SYMBOLS;
      else if (unformat (&i, "verbose-relocations"))
	tm->verbose |= FORMAT_ELF_MAIN_RELOCATIONS;
      else if (unformat (&i, "verbose-dynamic"))
	tm->verbose |= FORMAT_ELF_MAIN_DYNAMIC;
      else
	{
	  error = unformat_parse_error (&i);
	  goto done;
	}
    }

  if (!tm->input_file)
    {
      clib_warning ("No input file! Using test_bihash_template");
      tm->input_file = "test_bihash_template";
    }

  error = elf_read_file (em, tm->input_file);
  if (error)
    goto done;

  if (tm->set_interpreter)
    {
      clib_error_t *error = elf_set_interpreter (em, tm->set_interpreter);
      if (error)
	goto done;
      elf_delete_dynamic_rpath_entries (em);
    }

  if (tm->verbose)
    fformat (stdout, "%U", format_elf_main, em, tm->verbose);

  if (tm->output_file)
    error = elf_write_file (em, tm->output_file);

  elf_main_free (em);

done:
  if (error)
    {
      clib_error_report (error);
      return 1;
    }
  else
    return 0;
}

/*
 * fd.io coding-style-patch-verification: ON
 *
 * Local Variables:
 * eval: (c-set-style "gnu")
 * End:
 */