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/* Copyright (C) 1999, 2000, 2002 Red Hat, Inc.
This file is part of elfutils.
Written by Ulrich Drepper <drepper@redhat.com>, 1999.
This file is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
elfutils is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include <fcntl.h>
#include <gelf.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <system.h>
typedef struct hdr_node {
Elf *elf;
Elf_Arhdr *hdr;
struct hdr_node *next;
} hdr_node;
hdr_node *hdr_list = NULL;
int
main (int argc, char *argv[])
{
int fd;
Elf *elf;
Elf *subelf;
Elf_Cmd cmd;
off_t offset;
size_t todo;
if (argc < 4)
exit (1);
/* Open the archive. */
fd = open (argv[1], O_RDONLY);
if (fd == -1)
{
printf ("Cannot open input file: %m");
exit (1);
}
/* Set the ELF version. */
elf_version (EV_CURRENT);
/* Create an ELF descriptor. */
cmd = ELF_C_READ;
elf = elf_begin (fd, cmd, NULL);
if (elf == NULL)
{
printf ("Cannot create ELF descriptor: %s\n", elf_errmsg (-1));
exit (1);
}
/* If it is no archive punt. */
if (elf_kind (elf) != ELF_K_AR)
{
printf ("`%s' is no archive\n", argv[1]);
exit (1);
}
/* Get the elements of the archive one after the other. */
while ((subelf = elf_begin (fd, cmd, elf)) != NULL)
{
/* The the header for this element. */
Elf_Arhdr *arhdr = elf_getarhdr (subelf);
if (arhdr == NULL)
{
printf ("cannot get arhdr: %s\n", elf_errmsg (-1));
exit (1);
}
/* Keep a list of subelfs and their Elf_Arhdr. This is used to
verifiy that each archive member descriptor stores its own
Elf_Ahdr as opposed to the archive descriptor storing one
Elf_Ahdr at a time for all archive members. */
hdr_node *node = calloc (1, sizeof (hdr_node));
if (node == NULL)
{
printf ("calloc failed: %s\n", strerror (errno));
exit (1);
}
node->elf = subelf;
node->hdr = arhdr;
if (hdr_list != NULL)
{
node->next = hdr_list;
hdr_list = node;
}
else
hdr_list = node;
if (strcmp (arhdr->ar_name, argv[2]) == 0)
{
int outfd;
/* Get the offset of the file in the archive. */
offset = elf_getbase (subelf);
if (offset == -1)
{
printf ("\
Failed to get base address for the archive element: %s\n",
elf_errmsg (-1));
exit (1);
}
/* Open the output file. */
outfd = open (argv[3], O_CREAT | O_TRUNC | O_RDWR, DEFFILEMODE);
if (outfd == -1)
{
printf ("cannot open output file: %m");
exit (1);
}
/* Now write out the data. */
todo = arhdr->ar_size;
while (todo > 0)
{
char buf[1024];
ssize_t n = pread (fd, buf, MIN (sizeof buf, todo), offset);
if (n == 0)
break;
if (write (outfd, buf, n) != n)
{
puts ("Writing output failed");
exit (1);
}
offset += n;
todo -= n;
}
/* Check whether all the date was read and written out. */
if (todo != 0)
{
puts ("Reading archive member failed.");
exit (1);
}
/* Verify each subelf descriptor contains a unique copy of its arhdr
and then close each subelf descriptor. */
hdr_node *cur;
while ((cur = hdr_list) != NULL)
{
/* Verify that arhdr names are unique. */
for (hdr_node *n = cur->next; n != NULL; n = n->next)
{
if (strcmp (cur->hdr->ar_name, n->hdr->ar_name) == 0)
{
puts ("Duplicate ar_name");
exit (1);
}
if (strcmp (cur->hdr->ar_rawname, n->hdr->ar_rawname) == 0)
{
puts ("Duplicate ar_rawname");
exit (1);
}
}
if (elf_end (cur->elf) != 0)
{
printf ("Error while freeing subELF descriptor: %s\n",
elf_errmsg (-1));
exit (1);
}
hdr_list = cur->next;
free (cur);
}
/* Close the archive descriptor. */
if (elf_end (elf) != 0)
{
printf ("Freeing ELF descriptors failed: %s", elf_errmsg (-1));
exit (1);
}
close (outfd);
close (fd);
/* All went well. */
exit (0);
}
/* Get next archive element. */
cmd = elf_next (subelf);
}
/* When we reach this point we haven't found the given file in the
archive. */
printf ("File `%s' not found in archive\n", argv[2]);
exit (1);
}
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