radare2/libr/anal/data.c

/* radare - LGPL - Copyright 2012-2017 - pancake */

#include <r_anal.h>

#define MINLEN 1
static int is_string(const ut8 *buf, int size, int *len) {
	int i;
	if (size < 1) return 0;
	if (size > 3 && buf[0] && !buf[1] && buf[2] && !buf[3]) {
		*len = 1; // XXX: TODO: Measure wide string length
		return 2; // is wide
	}
	for (i = 0; i < size; i++) {
		if (!buf[i] && i > MINLEN) {
			*len = i;
			return 1;
		}
		if (buf[i] == 10 || buf[i] == 13 || buf[i] == 9) {
			continue;
		}
		if (buf[i] < 32 || buf[i] > 127) {
			// not ascii text
			return 0;
		}
		if (!IS_PRINTABLE (buf[i])) {
			*len = i;
			return 0;
		}
	}
	*len = i;
	return 1;
}

static int is_number(const ut8 *buf, int size) {
	ut64 n = r_mem_get_num (buf, size);
	return (n < UT32_MAX)? (int)n: 0;
}

static int is_null(const ut8 *buf, int size) {
	const char zero[8] = { 0, 0, 0, 0, 0, 0, 0, 0 };
	return (!memcmp (buf, &zero, size))? 1: 0;
}

static int is_invalid(const ut8 *buf, int size) {
	if (size < 1) return 1;
	if (size > 8) size = 8;
	return (!memcmp (buf, "\xff\xff\xff\xff\xff\xff\xff\xff", size))? 1: 0;
}

#define USE_IS_VALID_OFFSET 1
static ut64 is_pointer(RAnal *anal, const ut8 *buf, int size) {
	ut64 n;
	ut8 buf2[32];
	RIOBind *iob = &anal->iob;
	if (size > sizeof (buf2))
		size = sizeof (buf2);
	n = r_mem_get_num (buf, size);
	if (!n) return 1; // null pointer
#if USE_IS_VALID_OFFSET
	int r = iob->is_valid_offset (iob->io, n, 0);
	return r? n: 0LL;
#else
	// optimization to ignore very low and very high pointers
	// this makes disasm 5x faster, but can result in some false positives
	// we should compare with current offset, to avoid
	// short/long references. and discard invalid ones
	if (n < 0x1000) return 0;	// probably wrong
	if (n > 0xffffffffffffLL) return 0; // probably wrong

	if (iob->read_at (iob->io, n, buf2, size) != size) return 0;
	return is_invalid (buf2, size)? 0: n;
#endif
}

static bool is_bin(const ut8 *buf, int size) {
	// TODO: add more magic signatures heres
	if ((size >= 4 && !memcmp (buf, "\xcf\xfa\xed\xfe", 4))) {
		return true;
	}
	if ((size >= 4 && !memcmp (buf, "\x7f\x45\x4c\x46", 4))) { // \x7fELF
		return true;
	}
	if ((size >= 2 && !memcmp (buf, "MZ", 2))) {
		return true;
	}
	return false;
}

// TODO: add is_flag, is comment?

// XXX: optimize by removing all strlens here
R_API char *r_anal_data_to_string(RAnalData *d, RConsPrintablePalette *pal) {
	int i, len, idx, mallocsz = 1024;
	ut32 n32;
	char *line;

	if (!d) return NULL;

	line = malloc (mallocsz);
	if (!line) {
		eprintf ("Cannot allocate %d byte(s)\n", mallocsz);
		return NULL;
	}
	if (pal) {
		const char *k = pal->offset;
		snprintf (line, mallocsz, "%s0x%08" PFMT64x Color_RESET"  ", k, d->addr);
	} else {
		snprintf (line, mallocsz, "0x%08" PFMT64x "  ", d->addr);
	}
	n32 = (ut32)d->ptr;
	len = R_MIN (d->len, 8);
	for (i = 0, idx = strlen (line); i < len; i++) {
		int msz = mallocsz - idx;
		if (msz > 1) {
			snprintf (line + idx, msz, "%02x", d->buf[i]);
			idx += 2;
		}
	}
	if (i > 0 && d->len > len) {
		int msz = mallocsz - idx;
		snprintf (line + idx, msz, "..");
		idx += 2;
	}
	strcat (line, "  ");
	idx += 2;
	if (mallocsz - idx > 12) {
		switch (d->type) {
		case R_ANAL_DATA_TYPE_STRING:
			if (pal) {
				snprintf (line + idx, mallocsz - idx, "%sstring \"%s\""Color_RESET, pal->comment, d->str);
			} else {
				snprintf (line + idx, mallocsz - idx, "string \"%s\"", d->str);
			}
			break;
		case R_ANAL_DATA_TYPE_WIDE_STRING:
			strcat (line, "wide string");
			break;
		case R_ANAL_DATA_TYPE_NUMBER:
			if (pal) {
				const char *k = pal->num;
				if (n32 == d->ptr) {
					snprintf (line + idx, mallocsz - idx,
							"%snumber %d (0x%x)"Color_RESET, k, n32, n32);
				} else {
					snprintf (line + idx, mallocsz - idx,
							"%snumber %" PFMT64d " (0x%" PFMT64x ")"Color_RESET,
							k, d->ptr, d->ptr);
				}
			} else {
				if (n32 == d->ptr) {
					snprintf (line + idx, mallocsz - idx,
							"number %d 0x%x", n32, n32);
				} else {
					snprintf (line + idx, mallocsz - idx,
							"number %" PFMT64d " 0x%" PFMT64x,
							d->ptr, d->ptr);
				}
			}
			break;
		case R_ANAL_DATA_TYPE_POINTER:
			strcat (line, "pointer ");
			if (pal) {
				const char *k = pal->offset;
				sprintf (line + strlen (line), " %s0x%08" PFMT64x, k, d->ptr);
			} else {
				sprintf (line + strlen (line), " 0x%08" PFMT64x, d->ptr);
			}
			break;
		case R_ANAL_DATA_TYPE_INVALID:
			if (pal) {
				snprintf (line + idx, mallocsz - idx, "%sinvalid"Color_RESET, pal->invalid);
			} else {
				strcat (line, "invalid");
			}
			break;
		case R_ANAL_DATA_TYPE_HEADER:
			strcat (line, "header");
			break;
		case R_ANAL_DATA_TYPE_SEQUENCE:
			strcat (line, "sequence");
			break;
		case R_ANAL_DATA_TYPE_PATTERN:
			strcat (line, "pattern");
			break;
		case R_ANAL_DATA_TYPE_UNKNOWN:
			if (pal) {
				snprintf (line + idx, mallocsz - idx, "%sunknown"Color_RESET, pal->invalid);
			} else {
				strcat (line, "unknown");
			}
			break;
		default:
			if (pal) {
				snprintf (line + idx, mallocsz - idx, "%s(null)"Color_RESET, pal->b0x00);
			} else {
				strcat (line, "(null)");
			}
			break;
		}
	}
	return line;
}

R_API RAnalData *r_anal_data_new_string(ut64 addr, const char *p, int len, int type) {
	RAnalData *ad = R_NEW0 (RAnalData);
	if (!ad) return NULL;
	ad->str = NULL;
	ad->addr = addr;
	ad->type = type;
	if (len == 0) {
		len = strlen (p);
	}

	if (type == R_ANAL_DATA_TYPE_WIDE_STRING) {
		/* TODO: add support for wide strings */
	} else {
		ad->str = malloc (len + 1);
		if (!ad->str) {
			r_anal_data_free (ad);
			return NULL;
		}
		memcpy (ad->str, p, len);
		ad->str[len] = 0;
		ad->buf = malloc (len + 1);
		if (!ad->buf) {
			r_anal_data_free (ad);
			eprintf ("Cannot allocate %d byte(s)\n", len + 1);
			return NULL;
		}
		memcpy (ad->buf, ad->str, len + 1);
		ad->len = len + 1; // string length + \x00
	}
	ad->ptr = 0L;
	return ad;
}

R_API RAnalData *r_anal_data_new(ut64 addr, int type, ut64 n, const ut8 *buf, int len) {
	RAnalData *ad = R_NEW0 (RAnalData);
	int l = R_MIN (len, 8);
	if (!ad) {
		return NULL;
	}
	ad->buf = (ut8 *)&(ad->sbuf);
	memset (ad->buf, 0, 8);
	if (l < 1) {
		r_anal_data_free (ad);
		return NULL;
	}
	if (buf) {
		memcpy (ad->buf, buf, l);
	}
	ad->addr = addr;
	ad->type = type;
	ad->str = NULL;
	switch (type) {
	case R_ANAL_DATA_TYPE_PATTERN:
	case R_ANAL_DATA_TYPE_SEQUENCE:
		ad->len = len;
		break;
	default:
		ad->len = l;
	}
	ad->ptr = n;
	return ad;
}

R_API void r_anal_data_free(RAnalData *d) {
	if (d) {
		if (d->buf != (ut8 *)&(d->sbuf)) {
			free (d->buf);
		}
		free (d->str);
		free (d);
	}
}

R_API RAnalData *r_anal_data(RAnal *anal, ut64 addr, const ut8 *buf, int size, int wordsize) {
	ut64 dst = 0;
	int n, nsize = 0;
	int bits = anal->bits;
	int word = wordsize? wordsize: R_MIN (8, bits / 8);

	if (size < 4) {
		return NULL;
	}
	if (size >= word && is_invalid (buf, word)) {
		return r_anal_data_new (addr, R_ANAL_DATA_TYPE_INVALID, -1, buf, word);
	}
	{
		int i, len = R_MIN (size, 64);
		int is_pattern = 0;
		int is_sequence = 0;
		char ch = buf[0];
		char ch2 = ch + 1;
		for (i = 1; i < len; i++) {
			if (ch2 == buf[i]) {
				ch2++;
				is_sequence++;
			} else {
				is_sequence = 0;
			}
			if (ch == buf[i]) {
				is_pattern++;
			}
		}
		if (is_sequence > len - 2) {
			return r_anal_data_new (addr, R_ANAL_DATA_TYPE_SEQUENCE, -1,
						buf, is_sequence);
		}
		if (is_pattern > len - 2) {
			return r_anal_data_new (addr, R_ANAL_DATA_TYPE_PATTERN, -1,
						buf, is_pattern);
		}
	}
	if (size >= word && is_null (buf, word)) {
		return r_anal_data_new (addr, R_ANAL_DATA_TYPE_NULL, -1, buf, word);
	}
	if (is_bin (buf, size)) {
		return r_anal_data_new (addr, R_ANAL_DATA_TYPE_HEADER, -1, buf, word);
	}
	if (size >= word) {
		dst = is_pointer (anal, buf, word);
		if (dst) {
			return r_anal_data_new (addr, R_ANAL_DATA_TYPE_POINTER, dst, buf, word);
		}
	}
	switch (is_string (buf, size, &nsize)) {
	case 1: return r_anal_data_new_string (addr, (const char *)buf, nsize, R_ANAL_DATA_TYPE_STRING);
	case 2: return r_anal_data_new_string (addr, (const char *)buf, nsize, R_ANAL_DATA_TYPE_WIDE_STRING);
	}
	if (size >= word) {
		n = is_number (buf, word);
		if (n) return r_anal_data_new (addr, R_ANAL_DATA_TYPE_NUMBER, n, buf, word);
	}
	return r_anal_data_new (addr, R_ANAL_DATA_TYPE_UNKNOWN, dst, buf, R_MIN (word, size));
}

R_API const char *r_anal_data_kind(RAnal *a, ut64 addr, const ut8 *buf, int len) {
	int inv = 0;
	int unk = 0;
	int str = 0;
	int num = 0;
	int i, j;
	RAnalData *data;
	int word = a->bits / 8;
	for (i = j = 0; i < len; j++) {
		if (str && !buf[i])
			str++;
		data = r_anal_data (a, addr + i, buf + i, len - i, 0);
		if (!data) {
			i += word;
			continue;
		}
		switch (data->type) {
		case R_ANAL_DATA_TYPE_INVALID:
			inv++;
			i += word;
			break;
		case R_ANAL_DATA_TYPE_NUMBER:
			if (data->ptr > 1000) num++;
			i += word;
			break;
		case R_ANAL_DATA_TYPE_UNKNOWN:
			unk++;
			i += word;
			break;
		case R_ANAL_DATA_TYPE_STRING:
			if (data->len > 0) {
				i += data->len;
			} else i += word;
			str++;
			break;
		default:
			i += word;
		}
		r_anal_data_free (data);
	}
	if (j < 1) return "unknown";
	if ((inv * 100 / j) > 60) return "invalid";
	if ((unk * 100 / j) > 60) return "code";
	if ((num * 100 / j) > 60) return "code";
	if ((str * 100 / j) > 40) return "text";
	return "data";
}