rvalue.c

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// SPDX-FileCopyrightText: 2021 Florian Märkl <info@florianmaerkl.de>
// SPDX-FileCopyrightText: 2009-2019 pancake <pancake@nopcode.org>
// SPDX-License-Identifier: LGPL-3.0-only
 
#include <rz_reg.h>
#include <rz_util.h>
 
RZ_API RzBitVector *rz_reg_get_bv(RZ_NONNULL RzReg *reg, RZ_NONNULL RzRegItem *item) {
    rz_return_val_if_fail(reg && item, NULL);
    RzRegSet *regset = &reg->regset[item->arena];
    if (reg->big_endian) {
        return rz_bv_new_from_bytes_be(regset->arena->bytes, item->offset, item->size);
    } else {
        return rz_bv_new_from_bytes_le(regset->arena->bytes, item->offset, item->size);
    }
}
 
RZ_API bool rz_reg_set_bv(RZ_NONNULL RzReg *reg, RZ_NONNULL RzRegItem *item, RZ_NONNULL const RzBitVector *bv) {
    rz_return_val_if_fail(reg && item && bv, false);
    if (rz_bv_len(bv) != item->size) {
        return false;
    }
    if (item->offset % 8) {
        // TODO: this needs a bit offset arg in rz_bv_set_to_bytes_be()
        if (item->size == 1) {
            // workaround for flags edge-case while the offset mentioned above is not implemented yet
            rz_reg_set_value(reg, item, rz_bv_to_ut64(bv));
            return true;
        }
        RZ_LOG_ERROR("rz_reg_set_bv() for non-byte-aligned regs not supported yet.\n");
        return false;
    }
    RzRegSet *regset = &reg->regset[item->arena];
    int boff = item->offset / 8;
    if (reg->big_endian) {
        rz_bv_set_to_bytes_be(bv, regset->arena->bytes + boff);
    } else {
        rz_bv_set_to_bytes_le(bv, regset->arena->bytes + boff);
    }
    return true;
}
 
typedef ut32 ut27;
static ut27 rz_read_me27(const ut8 *buf, int boff) {
    ut27 ret = 0;
    rz_mem_copybits_delta((ut8 *)&ret, 18, buf, boff, 9);
    rz_mem_copybits_delta((ut8 *)&ret, 9, buf, boff + 9, 9);
    rz_mem_copybits_delta((ut8 *)&ret, 0, buf, boff + 18, 9);
    return ret;
}
 
RZ_API ut64 rz_reg_get_value_big(RzReg *reg, RzRegItem *item, utX *val) {
    rz_return_val_if_fail(reg && item, 0);
 
    ut64 ret = 0LL;
    int off = BITS2BYTES(item->offset);
    RzRegSet *regset = &reg->regset[item->arena];
    if (!regset->arena) {
        return 0LL;
    }
    switch (item->size) {
    case 80: // word + qword
        if (regset->arena->bytes && (off + 10 <= regset->arena->size)) {
            val->v80.Low = *((ut64 *)(regset->arena->bytes + off));
            val->v80.High = *((ut16 *)(regset->arena->bytes + off + 8));
        } else {
            eprintf("rz_reg_get_value: null or oob arena for current regset\n");
        }
        ret = val->v80.Low;
        break;
    case 96: // dword + qword
        if (regset->arena->bytes && (off + 12 <= regset->arena->size)) {
            val->v96.Low = *((ut64 *)(regset->arena->bytes + off));
            val->v96.High = *((ut32 *)(regset->arena->bytes + off + 8));
        } else {
            eprintf("rz_reg_get_value: null or oob arena for current regset\n");
        }
        ret = val->v96.Low;
        break;
    case 128: // qword + qword
        if (regset->arena->bytes && (off + 16 <= regset->arena->size)) {
            val->v128.Low = *((ut64 *)(regset->arena->bytes + off));
            val->v128.High = *((ut64 *)(regset->arena->bytes + off + 8));
        } else {
            eprintf("rz_reg_get_value: null or oob arena for current regset\n");
        }
        ret = val->v128.Low;
        break;
    case 256: // qword + qword + qword + qword
        if (regset->arena->bytes && (off + 32 <= regset->arena->size)) {
            val->v256.Low.Low = *((ut64 *)(regset->arena->bytes + off));
            val->v256.Low.High = *((ut64 *)(regset->arena->bytes + off + 8));
            val->v256.High.Low = *((ut64 *)(regset->arena->bytes + off + 16));
            val->v256.High.High = *((ut64 *)(regset->arena->bytes + off + 24));
        } else {
            eprintf("rz_reg_get_value: null or oob arena for current regset\n");
        }
        ret = val->v256.Low.Low;
        break;
    default:
        break;
    }
    return ret;
}
 
RZ_API ut64 rz_reg_get_value(RzReg *reg, RzRegItem *item) {
    rz_return_val_if_fail(reg && item, 0);
    if (!reg || !item || item->offset == -1) {
        return 0LL;
    }
    int off = BITS2BYTES(item->offset);
    RzRegSet *regset = &reg->regset[item->arena];
    if (!regset->arena) {
        return 0LL;
    }
    switch (item->size) {
    case 1: {
        int offset = item->offset / 8;
        if (offset >= regset->arena->size) {
            break;
        }
        return (regset->arena->bytes[offset] &
                   (1 << (item->offset % 8)))
            ? 1
            : 0;
    } break;
    case 4:
        if (regset->arena->size - off - 1 >= 0) {
            return (rz_read_at_ble8(regset->arena->bytes, off)) & 0xF;
        }
        break;
    case 8:
        if (regset->arena->size - off - 1 >= 0) {
            return rz_read_at_ble8(regset->arena->bytes, off);
        }
        break;
    case 16:
        if (regset->arena->size - off - 2 >= 0) {
            return rz_read_ble16(regset->arena->bytes + off, reg->big_endian);
        }
        break;
    case 27:
        if (off + 3 < regset->arena->size) {
            return rz_read_me27(regset->arena->bytes + off, 0);
        }
        break;
    case 32:
        if (off + 4 <= regset->arena->size) {
            return rz_read_ble32(regset->arena->bytes + off, reg->big_endian);
        }
        eprintf("rz_reg_get_value: 32bit oob read %d\n", off);
        break;
    case 64:
        if (regset->arena && regset->arena->bytes && (off + 8 <= regset->arena->size)) {
            return rz_read_ble64(regset->arena->bytes + off, reg->big_endian);
        }
        // eprintf ("rz_reg_get_value: null or oob arena for current regset\n");
        break;
    case 80: // long double
    case 96: // long floating value
        // FIXME: It is a precision loss, please implement me properly!
        return (ut64)rz_reg_get_longdouble(reg, item);
    case 128:
    case 256:
        // XXX 128 & 256 bit
        return (ut64)rz_reg_get_longdouble(reg, item);
    default:
        break;
    }
    return 0LL;
}
 
RZ_API ut64 rz_reg_get_value_by_role(RzReg *reg, RzRegisterId role) {
    // TODO use mapping from RzRegisterId to RzRegItem (via RzRegSet)
    return rz_reg_get_value(reg, rz_reg_get(reg, rz_reg_get_name(reg, role), -1));
}
 
RZ_API bool rz_reg_set_value(RzReg *reg, RzRegItem *item, ut64 value) {
    ut8 bytes[12];
    ut8 *src = bytes;
    bool unset_src = false;
    rz_return_val_if_fail(reg && item, false);
 
    if (rz_reg_is_readonly(reg, item)) {
        return true;
    }
    if (item->offset < 0) {
        return true;
    }
    RzRegArena *arena = reg->regset[item->arena].arena;
    if (!arena) {
        return false;
    }
    switch (item->size) {
    case 80:
    case 96: // long floating value
        rz_reg_set_longdouble(reg, item, (long double)value);
        unset_src = true;
        break;
    case 64:
        if (reg->big_endian) {
            rz_write_be64(src, value);
        } else {
            rz_write_le64(src, value);
        }
        break;
    case 32:
        if (reg->big_endian) {
            rz_write_be32(src, value);
        } else {
            rz_write_le32(src, value);
        }
        break;
    case 16:
        if (reg->big_endian) {
            rz_write_be16(src, value);
        } else {
            rz_write_le16(src, value);
        }
        break;
    case 8:
        rz_write_ble8(src, (ut8)(value & UT8_MAX));
        break;
    case 1:
        if (value) {
            ut8 *buf = arena->bytes + (item->offset / 8);
            int bit = (item->offset % 8);
            ut8 mask = (1 << bit);
            buf[0] = (buf[0] & (0xff ^ mask)) | mask;
        } else {
            int idx = item->offset / 8;
            if (idx + item->size > arena->size) {
                eprintf("RzRegSetOverflow %d vs %d\n", idx + item->size, arena->size);
                return false;
            }
            ut8 *buf = arena->bytes + idx;
            int bit = item->offset % 8;
            ut8 mask = 0xff ^ (1 << bit);
            buf[0] = (buf[0] & mask) | 0;
        }
        return true;
    case 128:
    case 256:
        // XXX 128 & 256 bit
        return false; // (ut64)rz_reg_get_longdouble (reg, item);
    default:
        RZ_LOG_ERROR("rz_reg_set_value: Bit size %d not supported\n", item->size);
        return false;
    }
    const bool fits_in_arena = (arena->size - BITS2BYTES(item->offset) - BITS2BYTES(item->size)) >= 0;
    if (!unset_src && fits_in_arena) {
        rz_mem_copybits(reg->regset[item->arena].arena->bytes +
                BITS2BYTES(item->offset),
            src, item->size);
        return true;
    }
    eprintf("rz_reg_set_value: Cannot set %s to 0x%" PFMT64x "\n", item->name, value);
    return false;
}
 
RZ_API bool rz_reg_set_value_by_role(RzReg *reg, RzRegisterId role, ut64 val) {
    // TODO use mapping from RzRegisterId to RzRegItem (via RzRegSet)
    const char *name = rz_reg_get_name(reg, role);
    if (!name) {
        return false;
    }
    RzRegItem *r = rz_reg_get(reg, name, -1);
    return rz_reg_set_value(reg, r, val);
}
 
RZ_API ut64 rz_reg_set_bvalue(RzReg *reg, RzRegItem *item, const char *str) {
    ut64 num = UT64_MAX;
    if (item && item->flags && str) {
        num = rz_str_bits_from_string(str, item->flags);
        if (num == UT64_MAX) {
            num = rz_num_math(NULL, str);
        }
        rz_reg_set_value(reg, item, num);
    }
    return num;
}
 
RZ_API RZ_HEAP char *rz_reg_get_bvalue(RzReg *reg, RzRegItem *item) {
    char *out = NULL;
    if (reg && item && item->flags) {
        out = malloc(strlen(item->flags) + 1);
        if (out) {
            ut64 num = rz_reg_get_value(reg, item);
            rz_str_bits(out, (ut8 *)&num,
                strlen(item->flags) * 8, item->flags);
        }
    }
    return out;
}
 
/* packed registers */
// packbits can be 8, 16, 32 or 64
// result value is always casted into ut64
// TODO: support packbits=128 for xmm registers
RZ_API ut64 rz_reg_get_pack(RzReg *reg, RzRegItem *item, int packidx, int packbits) {
    rz_return_val_if_fail(reg && item, 0LL);
 
    if (packbits < 1) {
        packbits = item->packed_size;
    }
    if (packbits > 64) {
        packbits = 64;
        eprintf("Does not support pack bits > 64\n");
    }
 
    ut64 ret = 0LL;
    const int packbytes = packbits / 8;
    const int packmod = packbits % 8;
    if (packmod) {
        eprintf("Invalid bit size for packet register\n");
        return 0LL;
    }
    if ((packidx + 1) * packbits > item->size) {
        eprintf("Packed index is beyond the register size\n");
        return 0LL;
    }
    RzRegSet *regset = &reg->regset[item->arena];
    if (!regset->arena) {
        return 0LL;
    }
    int off = BITS2BYTES(item->offset);
    off += (packidx * packbytes);
    if (regset->arena->size - off - 1 >= 0) {
        int i;
        for (i = packbytes - 1; i >= 0; i--) {
            ret = (ret << 8) | regset->arena->bytes[off + i];
        }
    }
    return ret;
}
 
// TODO: support packbits=128 for xmm registers
RZ_API int rz_reg_set_pack(RzReg *reg, RzRegItem *item, int packidx, int packbits, ut64 val) {
    rz_return_val_if_fail(reg && reg->regset->arena && item, false);
 
    if (packbits < 1) {
        packbits = item->packed_size;
    }
    if (packbits > 64) {
        packbits = 64;
        eprintf("Does not support pack bits > 64\n");
    }
 
    int packbytes = packbits / 8;
    if ((packidx + 1) * packbits > item->size) {
        eprintf("Packed index is beyond the register size\n");
        return false;
    }
    int off = BITS2BYTES(item->offset);
    off += (packidx * packbytes);
    if (reg->regset[item->arena].arena->size - BITS2BYTES(off) - BITS2BYTES(packbytes) >= 0) {
        ut8 *dst = reg->regset[item->arena].arena->bytes + off;
        int i;
        for (i = 0; i < packbytes; i++, val >>= 8) {
            dst[i] = val & 0xff;
        }
        return true;
    }
    eprintf("rz_reg_set_value: Cannot set %s to 0x%" PFMT64x "\n", item->name, val);
    return false;
}