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/* $OpenBSD: elfrdsetroot.c,v 1.26 2018/04/26 12:42:50 guenther Exp $ */
/* $NetBSD: rdsetroot.c,v 1.2 1995/10/13 16:38:39 gwr Exp $ */
/*
* Copyright (c) 1994 Gordon W. Ross
* Copyright (c) 1997 Per Fogelstrom. (ELF modifications)
* All rights reserved.
*
* 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.
*/
/*
* Copy a ramdisk image into the space reserved for it.
* Kernel variables: rd_root_size, rd_root_image
*/
#include <sys/types.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <elf.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include "elfrdsetroot.h"
struct elfhdr head;
/* Offsets relative to start of data segment. */
long rd_root_image_off, rd_root_size_off;
/* value in the location at rd_root_size_off */
off_t rd_root_size_val;
/* pointers to pieces of mapped file */
char *dataseg;
/* parameters to mmap digged out from program header */
off_t mmap_off;
size_t mmap_size;
__dead void usage(void);
int debug;
struct elf_fn *elf_fn;
int
main(int argc, char *argv[])
{
int ch, fd, n, xflag = 0, fsd;
char *fs = NULL;
char *file;
u_int32_t *ip;
while ((ch = getopt(argc, argv, "dx")) != -1) {
switch (ch) {
case 'd':
debug = 1;
break;
case 'x':
xflag = 1;
break;
default:
usage();
}
}
argc -= optind;
argv += optind;
if (argc == 1)
file = argv[0];
else if (argc == 2) {
file = argv[0];
fs = argv[1];
} else
usage();
fd = open(file, xflag ? O_RDONLY : O_RDWR, 0644);
if (fd < 0) {
perror(file);
exit(1);
}
if (fs) {
if (xflag)
fsd = open(fs, O_RDWR | O_CREAT | O_TRUNC, 0644);
else
fsd = open(fs, O_RDONLY, 0644);
} else {
if (xflag)
fsd = dup(STDOUT_FILENO);
else
fsd = dup(STDIN_FILENO);
}
if (fsd < 0) {
perror(fs);
exit(1);
}
if (pledge("stdio", NULL) == -1) {
perror("pledge");
exit(1);
}
n = read(fd, &head, sizeof(head));
if (n < sizeof(head)) {
fprintf(stderr, "%s: reading header\n", file);
exit(1);
}
if (!IS_ELF(head)) {
fprintf(stderr, "%s: bad magic number\n", file);
exit(1);
}
if (head.e_ident[EI_CLASS] == ELFCLASS32) {
elf_fn = &ELF32_fn;
} else if (head.e_ident[EI_CLASS] == ELFCLASS64) {
elf_fn = &ELF64_fn;
} else {
fprintf(stderr, "%s: invalid elf, not 32 or 64 bit", file);
exit(1);
}
elf_fn->locate_image(fd, &head, file, &rd_root_size_off,
&rd_root_image_off, &mmap_off, &mmap_size);
/*
* Map in the whole data segment.
* The file offset needs to be page aligned.
*/
dataseg = mmap(NULL, mmap_size,
xflag ? PROT_READ : PROT_READ | PROT_WRITE,
MAP_SHARED, fd, mmap_off);
if (dataseg == MAP_FAILED) {
fprintf(stderr, "%s: can not map data seg\n", file);
perror(file);
exit(1);
}
/*
* Find value in the location: rd_root_size
*/
ip = (u_int32_t *) (dataseg + rd_root_size_off);
rd_root_size_val = *ip;
if (debug)
fprintf(stderr, "rd_root_size val: 0x%llx (%lld blocks)\n",
(unsigned long long)rd_root_size_val,
(unsigned long long)rd_root_size_val >> 9);
/*
* Copy the symbol table and string table.
*/
if (debug)
fprintf(stderr, "copying root image...\n");
if (xflag) {
n = write(fsd, dataseg + rd_root_image_off,
(size_t)rd_root_size_val);
if (n != rd_root_size_val) {
perror("write");
exit(1);
}
} else {
struct stat sstat;
if (fstat(fsd, &sstat) == -1) {
perror("fstat");
exit(1);
}
if (S_ISREG(sstat.st_mode) &&
sstat.st_size > rd_root_size_val) {
fprintf(stderr, "ramdisk too small 0x%llx 0x%llx\n",
(unsigned long long)sstat.st_size,
(unsigned long long)rd_root_size_val);
exit(1);
}
n = read(fsd, dataseg + rd_root_image_off,
(size_t)rd_root_size_val);
if (n < 0) {
perror("read");
exit(1);
}
msync(dataseg, mmap_size, 0);
}
if (debug)
fprintf(stderr, "...copied %d bytes\n", n);
exit(0);
}
__dead void
usage(void)
{
extern char *__progname;
fprintf(stderr, "usage: %s [-dx] bsd [fs]\n", __progname);
exit(1);
}
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