NetBSD/sys/arch/amiga/stand/binpatch/binpatch.c

420 lines
11 KiB
C

/* $NetBSD: binpatch.c,v 1.7 1997/11/01 06:49:17 lukem Exp $ */
/* Author: Markus Wild mw@eunet.ch ??? */
/* Modified: Rob Leland leland@mitre.org */
#include <sys/types.h>
#include <a.out.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#ifdef __NetBSD__
/*
* assume NMAGIC files are linked at 0 (for kernel)
*/
#undef N_TXTADDR
#define N_TXTADDR(ex) \
((N_GETMAGIC2(ex) == (ZMAGIC|0x10000) || N_GETMAGIC2(ex) == NMAGIC) ? \
0 : __LDPGSZ)
#endif
static char synusage[] = "
NAME
\t%s - Allows the patching of BSD binaries
SYNOPSIS
\t%s [-HELP]
\t%s [-b|-w|-l] -s symbol[[[index]][=value]] binary
\t%s [-b|-w|-l] [-o offset] -s symbol [-r value] binary
\t%s [-b|-w|-l] [-o offset] -a address [-r value] binary
";
static char desusage[] = "DESCRIPTION
\tAllows the patching of BSD binaries, for example,a distributed
\tkernel. Recient additions allows the user to index into an array
\tand assign a value. Binpatch has internal variables to allow
\tyou to test it on itself under NetBSD.
OPTIONS
\t-a patch variable by specifying address in hex
\t-b symbol or address to be patched is 1 byte
\t-l symbol or address to be patched is 4 bytes (default)
\t-o offset to begin patching value relative to symbol or address
\t-r replace value, and print out previous value to stdout
\t-s patch variable by specifying symbol name. Use '[]'
\t to specify the 'index'. If '-b, -w or -l' not specified
\t then index value is used like an offset. Also can use '='
\t to assign value
\t-w symbol or address to be patched is 2 bytes
EXAMPLES
\tThis should print 100 (this is a nice reality check...)
\t\tbinpatch -l -s _hz netbsd
\tNow it gets more advanced, replace the value:
\t\tbinpatch -l -s _sbic_debug -r 1 netbsd
\tNow patch a variable at a given 'index' not offset,
\tunder NetBSD you must use '', under AmigaDos CLI '' is optional.:
\t\tbinpatch -w -s '_vieww[4]' -r 0 a.out
\tsame as
\t\tbinpatch -w -o 8 -s _vieww -r 0 a.out
\tAnother example of using []
\t\tbinpatch -s '_viewl[4]' -r 0 a.out
\tsame as
\t\tbinpatch -o 4 -s _viewl -r 0 a.out
\tOne last example using '=' and []
\t\tbinpatch -w -s '_vieww[4]=2' a.out
\tSo if the kernel is not finding your drives, you could enable
\tall available debugging options, helping to shed light on that problem.
\t\tbinpatch -l -s _sbic_debug -r 1 netbsd scsi-level
\t\tbinpatch -l -s _sddebug -r 1 netbsd sd-level (disk-driver)
\t\tbinpatch -l -s _acdebug -r 1 netbsd autoconfig-level
SEE ALSO
\tbinpatch.c binpatch(1)
";
extern char *optarg;
extern int optind;
volatile void error (char *);
static void Synopsis(char *program_name);
static void Usage(char *program_name);
static u_long FindAssign(char *symbol,u_long *rvalue);
static void FindOffset(char *symbol,u_long *index);
/* The following variables are so binpatch can be tested on itself */
int test = 1;
int testbss;
char foo = 23;
char viewb[10] = {0,0,1,0,1,1,0,1,1,1};
short vieww[10] = {0,0,1,0,1,1,0,1,1,1};
long viewl[10] = {0,0,1,0,1,1,0,1,1,1};
/* End of test binpatch variables */
int
main(int argc, char *argv[])
{
struct exec e;
int c;
u_long addr = 0, offset = 0;
u_long index = 0;/* Related to offset */
u_long replace = 0, do_replace = 0;
char *symbol = 0;
char size = 4; /* default to long */
char size_opt = 0; /* Flag to say size option was set, used with index */
char *fname;
char *pgname = argv[0]; /* Program name */
int fd;
int type, off;
u_long lval;
u_short sval;
u_char cval;
while ((c = getopt (argc, argv, "H:a:bwlr:s:o:")) != -1)
switch (c)
{
case 'H':
Usage(argv[0]);
break;
case 'a':
if (addr || symbol)
error ("only one address/symbol allowed");
if (! strncmp (optarg, "0x", 2))
sscanf (optarg, "%x", &addr);
else
addr = atoi (optarg);
if (! addr)
error ("invalid address");
break;
case 'b':
size = 1;
size_opt = 1;
break;
case 'w':
size = 2;
size_opt = 1;
break;
case 'l':
size = 4;
size_opt = 1;
break;
case 'r':
do_replace = 1;
if (! strncmp (optarg, "0x", 2))
sscanf (optarg, "%x", &replace);
else
replace = atoi (optarg);
break;
case 's':
if (addr || symbol)
error ("only one address/symbol allowed");
symbol = optarg;
break;
case 'o':
if (offset)
error ("only one offset allowed");
if (! strncmp (optarg, "0x", 2))
sscanf (optarg, "%x", &offset);
else
offset = atoi (optarg);
break;
}/* while switch() */
if (argc > 1)
{
if (addr || symbol)
{
argv += optind;
argc -= optind;
if (argc < 1)
error ("No file to patch.");
fname = argv[0];
if ((fd = open (fname, 0)) < 0)
error ("Can't open file");
if (read (fd, &e, sizeof (e)) != sizeof (e)
|| N_BADMAG (e))
error ("Not a valid executable.");
/* fake mid, so the N_ macros work on the amiga.. */
e.a_midmag |= 127 << 16;
if (symbol)
{
struct nlist nl[2];
if (offset == 0)
{
u_long new_do_replace = 0;
new_do_replace = FindAssign(symbol,&replace);
if (new_do_replace && do_replace)
error("Cannot use both '=' and '-r' option!");
FindOffset(symbol,&index);
if (size_opt)
offset = index*size; /* Treat like an index */
else
offset = index; /* Treat index like an offset */
if (new_do_replace)
do_replace = new_do_replace;
}
nl[0].n_un.n_name = symbol;
nl[1].n_un.n_name = 0;
if (nlist (fname, nl) != 0)
{
fprintf(stderr,"Symbol is %s ",symbol);
error ("Symbol not found.");
}
addr = nl[0].n_value;
type = nl[0].n_type & N_TYPE;
}
else
{
type = N_UNDF;
if (addr >= N_TXTADDR(e) && addr < N_DATADDR(e))
type = N_TEXT;
else if (addr >= N_DATADDR(e) && addr < N_DATADDR(e) + e.a_data)
type = N_DATA;
}
addr += offset;
/* if replace-mode, have to reopen the file for writing.
Can't do that from the beginning, or nlist() will not
work (at least not under AmigaDOS) */
if (do_replace)
{
close (fd);
if ((fd = open (fname, 2)) == -1)
error ("Can't reopen file for writing.");
}
if (type != N_TEXT && type != N_DATA)
error ("address/symbol is not in text or data section.");
if (type == N_TEXT)
off = addr - N_TXTADDR(e) + N_TXTOFF(e);
else
off = addr - N_DATADDR(e) + N_DATOFF(e);
if (lseek (fd, off, 0) == -1)
error ("lseek");
/* not beautiful, but works on big and little endian machines */
switch (size)
{
case 1:
if (read (fd, &cval, 1) != 1)
error ("cread");
lval = cval;
break;
case 2:
if (read (fd, &sval, 2) != 2)
error ("sread");
lval = sval;
break;
case 4:
if (read (fd, &lval, 4) != 4)
error ("lread");
break;
}/* switch size */
if (symbol)
printf ("%s(0x%x): %d (0x%x)\n", symbol, addr, lval, lval);
else
printf ("0x%x: %d (0x%x)\n", addr, lval, lval);
if (do_replace)
{
if (lseek (fd, off, 0) == -1)
error ("write-lseek");
switch (size)
{
case 1:
cval = replace;
if (cval != replace)
error ("byte-value overflow.");
if (write (fd, &cval, 1) != 1)
error ("cwrite");
break;
case 2:
sval = replace;
if (sval != replace)
error ("word-value overflow.");
if (write (fd, &sval, 2) != 2)
error ("swrite");
break;
case 4:
if (write (fd, &replace, 4) != 4)
error ("lwrite");
break;
}/* switch(size) */
}/* if (do_replace) */
close (fd);
}/* if(addr || symbol ) */
else
{
error("Must specify either address or symbol.");
}
}/* if argc < 1 */
else
{
Synopsis(pgname);
}
return(0);
}/* main () */
volatile void error (char *str)
{
fprintf (stderr, "%s\n", str);
exit (1);
}
/* Give user very short help to avoid scrolling screen much */
static void Synopsis(char *pgname)
{
fprintf(stdout,synusage,pgname,pgname,pgname,pgname,pgname);
}
static void Usage(char *pgname)
{
Synopsis(pgname);
fprintf(stdout,desusage);
exit(0);
}
/* FindOffset() - Determine if there is an offset, -or- index
embedded in the symbol.
If there is, return it, and truncate symbol to
exclude the [...].
Example: If view is declared as short view[10],
and we want to index the 3rd. element.
which is offset = (3 -1)*sizeof(short) =4.
we would use view[4], which becomes view,4.
The was the code is implemented the [value] is
treated as a index if-and-only-if a '-b -w -l' option
was given. Otherwise it is treated like an offset.
See above documentation in for of help!
*/
static void FindOffset(char *symbol,u_long *index)
{
char *sb=strchr(symbol,'['); /* Start of '[', now line must
contain matching']' */
char *eb=strchr(symbol,']'); /* End of ']' */
short sz=strlen(symbol); /* symbol size */
if (sb)
{
if (eb && (eb > sb))
{
if ((eb - symbol) == (sz - 1))
{
char *sindex; /* Start of index */
u_long newindex = 0;
/* In the future we could get fancy and parse the
sindex string for mathmatical expressions like:
(3 - 1)*2 = 4 from above example,
ugh forget I mentioned ot :-) !
*/
sindex = sb + 1;
*eb = '\0';
newindex = (u_long)atoi(sindex);
if (*index == 0)
{
*index = newindex;
*sb = '\0'; /* Make _view[3] look like _view */
}
else
fprintf(stderr,"Error index can only be specified once!\n");
}
else
{
fprintf(stderr,"Error: Garbage trailing ']'\n");
}
}
else
{
fprintf(stderr,"Error ']' in symbol before '[' !\n");
}
}/* if sb != 0 */
}/* FindOffset */
/* FindAssign : Scans symbol name for an '=number' strips it off
of the symbol and proceeds.
*/
static u_long FindAssign(char *symbol,u_long *rvalue)
{
char *ce = rindex(symbol,'='); /* Assign symbol some number */
char *cn = ce + 1; /* This should point at some number, no spaces allowed */
u_long dr = 0; /* flag for do_replace */
if (ce)
{
int nscan; /* number of variaables scanned in */
/* get the number to assign to symbol and strip off = */
for (cn=ce + 1;((*cn==' ')&&(*cn!='\0'));cn++)
;
if (! strncmp (cn, "0x", 2))
nscan = sscanf (cn, "%x",rvalue);
else
nscan = sscanf(cn,"%d",rvalue);
if (nscan != 1)
error("Invalid value following '='");
dr = 1;
*ce = '\0';/* Now were left with just symbol */
}/* if (ce) */
return(dr);
}/* FindAssign */