radare2/libr/reg/arena.c

/* radare - LGPL - Copyright 2009-2016 - pancake */

#include <r_reg.h>

/* non-endian safe - used for raw mapping with system registers */
R_API ut8 *r_reg_get_bytes(RReg *reg, int type, int *size) {
	RRegArena *arena;
	int i, sz, osize;
	ut8 *buf, *newbuf;
	if (size) *size = 0;
	if (type == -1) {
		/* serialize ALL register types in a single buffer */
		// owned buffer is returned
		osize = sz = 0;
		buf = malloc (8);
		if (!buf) {
			return NULL;
		}
		for (i = 0; i < R_REG_TYPE_LAST; i++) {
			arena = reg->regset[i].arena;
			sz += arena->size;
			newbuf = realloc (buf, sz);
			if (!newbuf) {
				break;
			}
			buf = newbuf;
			memcpy (buf + osize, arena->bytes, arena->size);
			osize = sz;
		}
		if (size) *size = sz;
		return buf;
	}
	if (type < 0 || type > (R_REG_TYPE_LAST - 1))
		return NULL;
	sz = reg->regset[type].arena->size;
	if (size)
		*size = sz;
	buf = malloc (sz);
	if (buf == NULL)
		return NULL;
	memcpy (buf, reg->regset[type].arena->bytes, sz);
	return buf;
}

/* deserialize ALL register types into buffer */
/* XXX does the same as r_reg_get_bytes ? */
R_API bool r_reg_read_regs(RReg *reg, ut8 *buf, const int len) {
	int i, off = 0;
	RRegArena *arena;
	for (i = 0; i < R_REG_TYPE_LAST; i++) {
		if (reg->regset[i].arena) {
			arena = reg->regset[i].arena;
		} else {
			arena = reg->regset[i].arena = R_NEW0 (RRegArena);
			if (arena) return false;
			arena->size = len;
			arena->bytes = malloc (len);
			if (!arena->bytes) {
				r_reg_arena_free (arena);
				return false;
			}
		}
		if (!arena->bytes) {
			arena->size = 0;
			return false;
		}
		memset (arena->bytes, 0, arena->size);
		memcpy (arena->bytes, buf + off,
		R_MIN (len - off, arena->size));
		off += arena->size;
		if (off > len) return false;
	}
	return true;
}

/* TODO reduce number of return statements */
R_API bool r_reg_set_bytes(RReg *reg, int type, const ut8 *buf, const int len) {
	int maxsz, ret = false;
	struct r_reg_set_t *regset;
	RRegArena *arena;
	if (len < 1 || !buf)
		return false;
	if (type < 0 || type >= R_REG_TYPE_LAST) return false;
	regset = &reg->regset[type];
	arena = regset->arena;
	maxsz = R_MAX (arena->size, len);
	if ((arena->size != len) || (arena->bytes == NULL)) {
		arena->bytes = calloc (1, maxsz);
		if (!arena->bytes) {
			arena->size = 0;
			return false;
		}
		arena->size = maxsz;
	}
	if (arena->size != maxsz) {
		ut8 *buf = realloc (arena->bytes, maxsz);
		if (buf) {
			arena->size = maxsz;
			arena->bytes = buf;
		} else {
			eprintf ("Error resizing arena to %d\n", len);
			return false;
		}
	}
	if (arena->bytes) {
		memset (arena->bytes, 0, maxsz);
		memcpy (arena->bytes, buf, len);
		ret = true;
	} else ret = false;
	return ret;
}

R_API int r_reg_fit_arena(RReg *reg) {
	RRegArena *arena;
	RListIter *iter;
	RRegItem *r;
	int size, i, newsize;

	for (i = 0; i < R_REG_TYPE_LAST; i++) {
		arena = reg->regset[i].arena;
		newsize = 0;
		r_list_foreach (reg->regset[i].regs, iter, r) {
			//int regsize_in_bytes = r->size / 8;
			// XXX: bits2bytes doesnt seems to work fine
			size = BITS2BYTES (r->offset + r->size);
			newsize = R_MAX (size, newsize);
		}
		if (newsize < 1) {
			free (arena->bytes);
			arena->bytes = NULL;
			arena->size = 0;
		} else {
			ut8 *buf = realloc (arena->bytes, newsize);
			if (!buf) {
				arena->bytes = NULL;
				arena->size = 0;
			} else {
				arena->size = newsize;
				arena->bytes = buf;
				memset (arena->bytes, 0, arena->size);
			}
		}
	}
	return true;
}

R_API RRegArena *r_reg_arena_new(int size) {
	RRegArena *arena = R_NEW (RRegArena);
	if (arena) {
		if (size < 1)
			size = 1;
		if (!(arena->bytes = malloc (size + 8))) {
			free (arena);
			arena = NULL;
		} else {
			arena->size = size;
			memset (arena->bytes, 0, size);
		}
	}
	return arena;
}

R_API void r_reg_arena_free(RRegArena *ra) {
	if (ra) {
		free (ra->bytes);
		free (ra);
	}
}

R_API void r_reg_arena_swap(RReg *reg, int copy) {
	// XXX this api should be deprecated
	int i;
	for (i = 0; i < R_REG_TYPE_LAST; i++) {
		if (r_list_length (reg->regset[i].pool) > 1) {
			RListIter *ia = reg->regset[i].pool->tail;
			RListIter *ib = reg->regset[i].pool->tail->p;
			void *tmp = ia->data;
			ia->data = ib->data;
			ib->data = tmp;
			reg->regset[i].arena = ia->data;
		} else {
			//eprintf ("Cannot pop more\n");
			break;
		}
	}
#if 0
	int index = (++reg->iters)%2;
	r_reg_arena_set (reg, index, copy);
#endif
}

R_API void r_reg_arena_pop(RReg *reg) {
	RRegArena *a;
	int i;
	for (i = 0; i < R_REG_TYPE_LAST; i++) {
		if (r_list_length (reg->regset[i].pool) < 2)
			continue;
		a = r_list_pop (reg->regset[i].pool);
		r_reg_arena_free (a);
		a = reg->regset[i].pool->tail->data;
		if (a) reg->regset[i].arena = a;
	}
}

R_API int r_reg_arena_push(RReg *reg) {
	int i;
	for (i = 0; i < R_REG_TYPE_LAST; i++) {
		RRegArena *a = reg->regset[i].arena; // current arena
		if (!a) continue;
		RRegArena *b = r_reg_arena_new (a->size); // new arena
		if (!b) continue;
		if (a->size >= b->size) {
			memcpy (b->bytes, a->bytes, b->size);
		} else {
			memcpy (b->bytes, a->bytes, a->size);
			memset (b->bytes + a->size, 0, b->size - a->size);
		}
		r_list_push (reg->regset[i].pool, b);
		reg->regset[i].arena = b;
	}
	return r_list_length (reg->regset[0].pool);
}

R_API void r_reg_arena_zero(RReg *reg) {
	int i;
	for (i = 0; i < R_REG_TYPE_LAST; i++) {
		RRegArena *a = reg->regset[i].arena;
		if (a->size > 0) {
			memset (reg->regset[i].arena->bytes, 0, a->size);
		}
	}
}

R_API ut8 *r_reg_arena_peek(RReg *reg) {
	RRegSet *regset = r_reg_regset_get (reg, R_REG_TYPE_GPR);
	if (!reg || !regset || !regset->arena || (regset->arena->size < 1)) {
		return NULL;
	}
	ut8 *ret = malloc (regset->arena->size);
	if (!ret) return NULL;
	memcpy (ret, regset->arena->bytes, regset->arena->size);
	return ret;
}

R_API void r_reg_arena_poke(RReg *reg, const ut8 *ret) {
	RRegSet *regset = r_reg_regset_get (reg, R_REG_TYPE_GPR);
	if (!ret || !regset || !regset->arena || !regset->arena->bytes)
		return;
	memcpy (regset->arena->bytes, ret, regset->arena->size);
}


R_API int r_reg_arena_set_bytes(RReg *reg, const char* str) {
	while (IS_WHITESPACE (*str)) {
		str++;
	}
	int len = r_hex_str_is_valid (str);
	if (len == -1) {
		eprintf ("Invalid input\n");
		return -1;
	}
	int bin_str_len = (len + 1) / 2; //2 hex chrs for 1 byte
	ut8* bin_str = malloc (bin_str_len);
	if (!bin_str) {
		eprintf ("Failed to decode hex str.\n");
		return -1;
	}
	r_hex_str2bin (str, bin_str);

	int i, n = 0; //n - cumulative sum of arena's sizes
	for (i = 0; i < R_REG_TYPE_LAST; ++i) {
		int sz = reg->regset[i].arena->size;
		int bl = bin_str_len - n; //bytes left
		if (bl - n < sz) {
			//r_reg_set_bytes checks if bl-n==0 :p
			r_reg_set_bytes (reg, i, bin_str + n, bl - n);
			break;
		}
		r_reg_set_bytes (reg, i, bin_str + n, bin_str_len - n);
		n += sz;
	}
	free (bin_str);
	return 0;
}