Magic-Mirror/radare2
1
0
Fork 0
mirror of https://github.com/radareorg/radare2.git synced 2025-03-04 20:39:46 +00:00
Code Issues Actions 5 Packages Projects Releases Wiki Activity

Honor cfg.bigendian in wopO for debrujn patterns

Browse Source
This commit is contained in:
pancake 2016-08-14 23:49:13 +02:00
parent 2b35ce2ed4
commit deb05ed383
2 changed files with 39 additions and 42 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
libr/core/cmd_write.c
View File

@ -221,7 +221,7 @@ static void cmd_write_op (RCore *core, const char *input) {
break;
case 'p': // debrujin patterns
switch (input[2]) {
case 'D':
case 'D': // "wopD"
len = (int)(input[3]==' ')?
r_num_math (core->num, input + 3): core->blocksize;
if (len > 0) {
@ -234,11 +234,11 @@ static void cmd_write_op (RCore *core, const char *input) {
}
}
break;
case 'O':
len = (int)(input[3]==' ')?
r_num_math (core->num, input + 3): core->blocksize;
//core->assembler->big_endian 1 if big but in r_debruijn_offset is the contrary
core->num->value = r_debruijn_offset (len, !core->assembler->big_endian);
case 'O': // "wopO"
len = (int)(input[3]==' ')
? r_num_math (core->num, input + 3)
: core->blocksize;
core->num->value = r_debruijn_offset (len, r_config_get_i (core->config, "cfg.bigendian"));
r_cons_printf ("%"PFMT64d"\n", core->num->value);
break;
case '\0':

69
libr/util/debruijn.c
View File

@ -87,22 +87,6 @@ R_API char* r_debruijn_pattern(int size, int start, const char* charset) {
return pat2;
}
// In-place reverse a string.
static void reverse_string(char* str) {
char *start = str, *end, temp;
// Skip null and empty strings.
if (!str || !*str)
return;
end = start + strlen (str) - 1;
while (end > start) {
temp = *start;
*start = *end;
*end = temp;
++start;
--end;
}
}
// Generate a cyclic pattern of 0x10000 long.
// The returned string is malloced, and it is the responsibility of the caller
// to free the memory.
@ -115,36 +99,49 @@ static char* cyclic_pattern_long() {
// Finds the offset of a given value in a cyclic pattern of an integer.
// Guest endian = 1 if little, 0 if big.
// Host endian = 1 if little, 0 if big.
R_API int r_debruijn_offset(ut64 value, int guest_endian) {
ut64 needle_l[2]; // Hold the value as a string.
char* needle, *pattern;
int n, host_endian, retval;
R_API int r_debruijn_offset(ut64 value, int big_endian) {
char* needle, *pattern, buf[9];
int n, retval;
char* pch;
if (value == 0)
if (value == 0) {
return -1;
pattern = cyclic_pattern_long();
needle_l[0] = value;
needle_l[1] = 0;
needle = (char*)&needle_l;
// On little-endian systems with more bits than the binary being analyzed, we
// may need to find the begin of this.
while (!needle[0])
needle++;
}
pattern = cyclic_pattern_long ();
if (big_endian) {
buf[7] = value & 0xff;
buf[6] = (value >> 8) & 0xff;
buf[5] = (value >> 16) & 0xff;
buf[4] = (value >> 24) & 0xff;
buf[3] = (value >> 32) & 0xff;
buf[2] = (value >> 40) & 0xff;
buf[1] = (value >> 48) & 0xff;
buf[0] = (value >> 56) & 0xff;
buf[8] = 0; // EOF
} else {
buf[0] = value & 0xff;
buf[1] = (value >> 8) & 0xff;
buf[2] = (value >> 16) & 0xff;
buf[3] = (value >> 24) & 0xff;
buf[4] = (value >> 32) & 0xff;
buf[5] = (value >> 40) & 0xff;
buf[6] = (value >> 48) & 0xff;
buf[7] = (value >> 56) & 0xff;
buf[8] = 0; // EOF
}
for (needle = buf; !*needle; needle++) {
/* do nothing here */
}
// we should not guess the endian. its already handled by other functions
// and configure by the user in cfg.bigendian
n = 1;
// little endian if true
host_endian = (*(char*)&n == 1) ? 1 : 0;
if (host_endian != guest_endian)
reverse_string (needle);
pch = strstr (pattern, needle);
retval = -1;
if (pch != NULL)
retval = (int)(pch - pattern);
if (pch) {
retval = (int)(size_t)(pch - pattern);
}
free (pattern);
return retval;
}