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Diffstat (limited to 'sbin/i386/nextboot/nextboot.c')
| -rw-r--r-- | sbin/i386/nextboot/nextboot.c | 231 |
1 files changed, 231 insertions, 0 deletions
diff --git a/sbin/i386/nextboot/nextboot.c b/sbin/i386/nextboot/nextboot.c new file mode 100644 index 0000000..2398b56 --- /dev/null +++ b/sbin/i386/nextboot/nextboot.c @@ -0,0 +1,231 @@ + +/* + * Copyright (c) 1996 Whistle Communications + * All Rights Reserved. + * + * Permission to use, copy, modify and distribute this software and its + * documentation is hereby granted, provided that both the copyright + * notice and this permission notice appear in all copies of the + * software, derivative works or modified versions, and any portions + * thereof, and that both notices appear in supporting documentation. + * + * Whistle Communications allows free use of this software in its "as is" + * condition. Whistle Communications disclaims any liability of any kind for + * any damages whatsoever resulting from the use of this software. + */ + + +#include <sys/types.h> +#include <sys/disklabel.h> +#include <stdio.h> +#include <string.h> +#include <errno.h> +#include <sys/stat.h> +#include <sys/ioctl.h> +#include <fcntl.h> +#include <unistd.h> +#include <stdlib.h> +#include <unistd.h> + +struct mboot +{ + unsigned char padding[2]; /* force the longs to be long alligned */ + unsigned char bootinst[DOSPARTOFF]; + struct dos_partition parts[4]; + unsigned short int signature; +}; +struct mboot mboot; + +#define NAMEBLOCK 1 /* 2nd block */ +#define BLOCKSIZE 512 +#define ENABLE_MAGIC 0xfadefeed +#define DISABLE_MAGIC 0xfadefade +static int bflag; +static int eflag; +static int dflag; +static int nameblock = NAMEBLOCK; + +#define BOOT_MAGIC 0xAA55 + +extern char *__progname; + +static void usage(void) { + fprintf (stderr, " usage: %s [-b] device bootstring [bootstring] ...\n" + , __progname); + fprintf (stderr, " or: %s {-e,-d} device \n" , __progname); + fprintf (stderr, "The -e and -d flags are mutually exclusive\n"); + exit(1); +} + +main (int argc, char** argv) +{ + int fd = -1; + char namebuf[1024], *cp = namebuf; + int i,j; + int ch; + int part; + + bflag = 0; + while ((ch = getopt(argc, argv, "bde")) != EOF) { + switch(ch) { + case 'b': + bflag = 1; + break; + case 'd': + dflag = 1; + break; + case 'e': + eflag = 1; + break; + case '?': + default: + usage(); + } + } + argc -= optind; + argv += optind; + + if ( (dflag + eflag + bflag) > 1 ) { + usage(); + } + if (dflag + eflag){ + if(argc != 1 ) { + usage(); + } + } else { + if (argc <2) { + usage(); + } + } + if ((fd = open(argv[0], O_RDWR, 0)) < 0) { + perror("open"); + printf ("file: %s\n",argv[0]); + usage(); + } + + argc--; + argv++; + + /******************************************* + * Check that we have an MBR + */ + if (lseek(fd,0,0) == -1) { + perror("lseek"); + exit(1); + } + if (read (fd,&mboot.bootinst[0],BLOCKSIZE ) != BLOCKSIZE) { + perror("read0"); + exit(1); + } + if(mboot.signature != (unsigned short)BOOT_MAGIC) { + printf(" no fdisk part.. not touching block 1\n"); + exit(1); + } + + /******************************************* + * And check that none of the partitions in it cover the name block; + */ + for ( part = 0; part < 4; part++) { + if( mboot.parts[part].dp_size + && (mboot.parts[part].dp_start <= NAMEBLOCK) + && (mboot.parts[part].dp_start + + mboot.parts[part].dp_size > NAMEBLOCK)) { + printf(" Name sector lies within a Bios partition.\n"); + printf(" Aborting write.\n"); + exit(1); + } + } + + + /******************************************* + * Now check the name sector itself to see if it's been initialised. + */ + if (lseek(fd,NAMEBLOCK * BLOCKSIZE,0) == -1) { + perror("lseek"); + exit(1); + } + if ( read (fd,namebuf,BLOCKSIZE ) != BLOCKSIZE) { + perror("read1"); + exit(1); + } + /******************************************* + * check if we are just enabling or disabling + * Remember the flags are exlusive.. + */ + if(!bflag) { /* don't care what's there if bflag is set */ + switch(*(unsigned long *)cp) + { + case DISABLE_MAGIC: + case ENABLE_MAGIC: + break; + default: + fprintf(stderr, + "namesector not initialised.." + "use the -b flag..\n"); + exit(1); + } + } + + + /******************************************* + * If the z or r flag is set, damage or restore the magic number.. + * to disable/enable the feature + */ + if(dflag) { + *(unsigned long *)cp = DISABLE_MAGIC; + } else { + *(unsigned long *)cp = ENABLE_MAGIC; + } + if ((!dflag) && (!eflag)) { + /******************************************* + * Create a new namesector in ram + */ + cp += 4; + for ( i = 0 ; i < argc ; i++ ) { + *cp++ = 'D'; + *cp++ = 'N'; + j = strlen(argv[i]); + strncpy(cp,argv[i],j); + cp += j; + *cp++ = 0; + } + *cp++ = 0xff; + *cp++ = 0xff; + *cp++ = 0xff; + namebuf[BLOCKSIZE-1] = 0; /* paranoid */ + namebuf[BLOCKSIZE] = 0xff; + } + + /******************************************* + * write it to disk. + */ + if (lseek(fd,NAMEBLOCK * BLOCKSIZE,0) == -1) { + perror("lseek"); + exit(1); + } + if(write (fd,namebuf,BLOCKSIZE ) != BLOCKSIZE) { + perror("write"); + exit(1); + } + +#if 0 + /******************************************* + * just to be safe/paranoid.. read it back.. + * and print it.. + */ + if (lseek(fd,NAMEBLOCK * BLOCKSIZE,0) == -1) { + perror("lseek (second) "); + exit(1); + } + read (fd,namebuf,512); + for (i = 0;i< 16;i++) { + for ( j = 0; j < 16; j++) { + printf("%02x ",(unsigned char )namebuf[(i*16) + j ]); + } + printf("\n"); + } +#endif + exit(0); +} + + |
