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/* $NetBSD: binpatch.c,v 1.1.1.1 2004/07/23 03:37:26 atatat Exp $ */
/*
* ------------------------------------------------------------------------
* "THE BEER-WARE LICENSE" (Revision 42):
* Andrew Brown <atatat@NetBSD.org> wrote this file. As long as you
* retain this notice you can do whatever you want with this stuff.
* If we meet some day, and you think this stuff is worth it, you can
* buy me a beer in return.
* ------------------------------------------------------------------------
*/
#include <sys/types.h>
#include <sys/stat.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
static int
die(int rc, const char *msg)
{
if (rc)
perror(msg);
else
fprintf(stderr, "%s\n", msg);
exit(1);
}
static void
cvt(const char *s, const char *i, unsigned char *o, size_t l)
{
int t, x;
for (t = 0; t < l; t++) {
x = i[2 * t];
if (x >= '0' && x <= '9')
x -= '0';
else if (x >= 'a' && x <= 'f')
x -= 'a' - 10;
else if (x >= 'A' && x <= 'F')
x -= 'A' - 10;
else
die(0, s);
o[t] = x * 16;
x = i[2 * t + 1];
if (x >= '0' && x <= '9')
x -= '0';
else if (x >= 'a' && x <= 'f')
x -= 'a' - 10;
else if (x >= 'A' && x <= 'F')
x -= 'A' - 10;
else
die(0, s);
o[t] += x;
}
}
int
main(int argc, char *argv[])
{
struct stat st;
char *key, *value;
int f, i;
unsigned char *buf, *get, *put;
size_t lget, lput;
off_t sz, cmp_off, skip_off;
f = -1;
get = put = NULL;
lget = lput = 0;
sz = cmp_off = skip_off = -1;
while (--argc > 0) {
key = *++argv;
if ((value = strchr(key, '=')) == NULL)
die(0, "value required");
else
*value++ = '\0';
if (strcmp(key, "file") == 0) {
f = open(value, O_RDWR);
if (f == -1)
die(1, "file");
}
else if (strcmp(key, "size") == 0) {
char *t;
errno = 0;
sz = strtol(value, &t, 0);
if (errno != 0)
die(1, "size");
}
else if (strcmp(key, "offset") == 0) {
char *t;
errno = 0;
cmp_off = strtol(value, &t, 0);
if (errno != 0)
die(1, "offset");
}
else if (strcmp(key, "compare") == 0) {
lget = strlen(value);
if (lget % 2 != 0)
die(0, "compare");
lget /= 2;
get = malloc(lget);
buf = malloc(lget);
cvt("compare", value, get, lget);
}
else if (strcmp(key, "skip") == 0) {
char *t;
errno = 0;
skip_off = strtol(value, &t, 0);
if (errno != 0)
die(1, "offset");
}
else if (strcmp(key, "replace") == 0) {
lput = strlen(value);
if (lput % 2 != 0)
die(0, "replace");
lput /= 2;
put = malloc(lput);
cvt("replace", value, put, lput);
}
}
/*
* ./binpatch
* file=${MOZILLA_HOME}/netscape
* size=13823336
* offset=0x008073e9
* compare=6a00e82406a3ffe81f0ca3ff
* skip=2
* replace=9090909090
*/
if (f == -1)
die(0, "file missing");
if (get == NULL || lget == 0)
die(0, "compare missing");
if (put == NULL || lput == 0)
die(0, "replace missing");
if (sz == -1)
die(0, "size missing");
if (cmp_off == -1)
die(0, "offset missing");
if (skip_off == -1)
die(0, "skip missing");
if (skip_off < 0 ||
(skip_off == 0 && lput >= lget) ||
(skip_off > 0 && skip_off + lput > lget))
die(0, "illegal skip");
if (fstat(f, &st) == -1)
die(1, "fstat");
if (st.st_size != sz)
die(0, "wrong size");
if (lseek(f, cmp_off, SEEK_SET) == -1)
die(1, "lseek");
if (read(f, buf, lget) != lget)
die(1, "read");
if (memcmp(buf, get, lget) != 0)
die(0, "instructions not found");
if (lseek(f, cmp_off + skip_off, SEEK_SET) == -1)
die(1, "lseek");
if (write(f, put, lput) != lput)
die(1, "write");
if (close(f) != 0)
die(1, "close");
return (0);
}
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