Add a "I know it points to my foot!" -f option.

PR:		3288
Reviewed by:	phk
Submitted by:	Martin Kammerhofer <dada@freepass.tu-graz.ac.at>
This commit is contained in:
Poul-Henning Kamp 1997-09-18 18:27:34 +00:00
parent 0d150bcf0b
commit f8bb3e895f
2 changed files with 72 additions and 20 deletions

View File

@ -6,7 +6,7 @@
* this stuff is worth it, you can buy me a beer in return. Poul-Henning Kamp
* ----------------------------------------------------------------------------
*
* $Id$
* $Id: write_mfs_in_kernel.c,v 1.3 1997/02/22 14:10:31 peter Exp $
*
* This program patches a filesystem into a kernel made with MFS_ROOT
* option.
@ -21,17 +21,33 @@
#include <sys/stat.h>
#include <ufs/ffs/fs.h>
static int force = 0; /* don't check for zeros, may corrupt kernel */
int
main(int argc, char **argv)
{
unsigned char *buf_kernel, *buf_fs, *p,*q;
int fd_kernel, fd_fs;
unsigned char *buf_kernel, *buf_fs, *p,*q, *prog;
int fd_kernel, fd_fs, ch, errs=0;
struct stat st_kernel, st_fs;
u_long l;
if (argc < 3) {
fprintf(stderr,"Usage:\n\t%s kernel fs\n");
prog= *argv;
while ((ch = getopt(argc, argv, "f")) != EOF)
switch(ch) {
case 'f':
force = 1 - force;
break;
default:
errs++;
}
argc -= optind;
argv += optind;
if (errs || argc != 2) {
fprintf(stderr,"Usage:\n\t%s [-f] kernel fs\n", prog);
exit(2);
}
--argv; /* original prog did not use getopt(3) */
fd_kernel = open(argv[1],O_RDWR);
if (fd_kernel < 0) { perror(argv[1]); exit(2); }
fstat(fd_kernel,&st_kernel);
@ -51,16 +67,17 @@ main(int argc, char **argv)
goto found;
fprintf(stderr,"MFS filesystem signature not found in %s\n",argv[1]);
exit(1);
found:
for(l=0,q= p + SBOFF; l < st_fs.st_size - SBOFF ; l++,q++ )
if (*q)
goto fail;
found:
if (!force)
for(l=0,q= p + SBOFF; l < st_fs.st_size - SBOFF ; l++,q++ )
if (*q)
goto fail;
memcpy(p+SBOFF,buf_fs+SBOFF,st_fs.st_size-SBOFF);
lseek(fd_kernel,0L,SEEK_SET);
if (st_kernel.st_size != write(fd_kernel,buf_kernel,st_kernel.st_size))
{ perror(argv[1]); exit(2); }
exit(0);
fail:
fail:
l += SBOFF;
fprintf(stderr,"Obstruction in kernel after %ld bytes (%ld Kbyte)\n",
l, l/1024);
@ -68,3 +85,12 @@ main(int argc, char **argv)
(u_long)st_fs.st_size, (u_long)st_fs.st_size/1024);
exit(1);
}
/*
* I added a '-f' option to force writing the image into the kernel, even when
* there is already data (i.e. not zero) in the written area. This is useful
* to rewrite a changed MFS-image. Beware: If the written image is larger than
* the space reserved in the kernel (with option MFS_ROOT) then
* THIS WILL CORRUPT THE KERNEL!
*
*/

View File

@ -6,7 +6,7 @@
* this stuff is worth it, you can buy me a beer in return. Poul-Henning Kamp
* ----------------------------------------------------------------------------
*
* $Id$
* $Id: write_mfs_in_kernel.c,v 1.3 1997/02/22 14:10:31 peter Exp $
*
* This program patches a filesystem into a kernel made with MFS_ROOT
* option.
@ -21,17 +21,33 @@
#include <sys/stat.h>
#include <ufs/ffs/fs.h>
static int force = 0; /* don't check for zeros, may corrupt kernel */
int
main(int argc, char **argv)
{
unsigned char *buf_kernel, *buf_fs, *p,*q;
int fd_kernel, fd_fs;
unsigned char *buf_kernel, *buf_fs, *p,*q, *prog;
int fd_kernel, fd_fs, ch, errs=0;
struct stat st_kernel, st_fs;
u_long l;
if (argc < 3) {
fprintf(stderr,"Usage:\n\t%s kernel fs\n");
prog= *argv;
while ((ch = getopt(argc, argv, "f")) != EOF)
switch(ch) {
case 'f':
force = 1 - force;
break;
default:
errs++;
}
argc -= optind;
argv += optind;
if (errs || argc != 2) {
fprintf(stderr,"Usage:\n\t%s [-f] kernel fs\n", prog);
exit(2);
}
--argv; /* original prog did not use getopt(3) */
fd_kernel = open(argv[1],O_RDWR);
if (fd_kernel < 0) { perror(argv[1]); exit(2); }
fstat(fd_kernel,&st_kernel);
@ -51,16 +67,17 @@ main(int argc, char **argv)
goto found;
fprintf(stderr,"MFS filesystem signature not found in %s\n",argv[1]);
exit(1);
found:
for(l=0,q= p + SBOFF; l < st_fs.st_size - SBOFF ; l++,q++ )
if (*q)
goto fail;
found:
if (!force)
for(l=0,q= p + SBOFF; l < st_fs.st_size - SBOFF ; l++,q++ )
if (*q)
goto fail;
memcpy(p+SBOFF,buf_fs+SBOFF,st_fs.st_size-SBOFF);
lseek(fd_kernel,0L,SEEK_SET);
if (st_kernel.st_size != write(fd_kernel,buf_kernel,st_kernel.st_size))
{ perror(argv[1]); exit(2); }
exit(0);
fail:
fail:
l += SBOFF;
fprintf(stderr,"Obstruction in kernel after %ld bytes (%ld Kbyte)\n",
l, l/1024);
@ -68,3 +85,12 @@ main(int argc, char **argv)
(u_long)st_fs.st_size, (u_long)st_fs.st_size/1024);
exit(1);
}
/*
* I added a '-f' option to force writing the image into the kernel, even when
* there is already data (i.e. not zero) in the written area. This is useful
* to rewrite a changed MFS-image. Beware: If the written image is larger than
* the space reserved in the kernel (with option MFS_ROOT) then
* THIS WILL CORRUPT THE KERNEL!
*
*/