ossp-pkg/xds/xds_engine_xdr.c
/*
** OSSP xds - Extensible Data Serialization
** Copyright (c) 2001-2005 Ralf S. Engelschall <rse@engelschall.com>
** Copyright (c) 2001-2005 The OSSP Project <http://www.ossp.org/>
** Copyright (c) 2001-2005 Cable & Wireless <http://www.cw.com/>
**
** This file is part of OSSP xds, an extensible data serialization
** library which can be found at http://www.ossp.org/pkg/lib/xds/.
**
** Permission to use, copy, modify, and distribute this software for
** any purpose with or without fee is hereby granted, provided that
** the above copyright notice and this permission notice appear in all
** copies.
**
** THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
** WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
** MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
** IN NO EVENT SHALL THE AUTHORS AND COPYRIGHT HOLDERS AND THEIR
** CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
** USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
** ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
** OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
** OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
** SUCH DAMAGE.
**
** xds_engine_xdr.c: XDR encoding/decoding engine
*/
#include <string.h>
#include "xds.h"
/*
* Encode/decode signed 32-bit integer values.
*/
int xdr_encode_int32(xds_t *xds, void *engine_context,
void *buffer, size_t buffer_size,
size_t *used_buffer_size, va_list *args)
{
xds_uint32_t tmp;
xds_int32_t value;
xds_init_encoding_engine(4);
/* Get value and format it into the buffer. */
value = va_arg(*args, xds_uint32_t);
if (value < 0) {
value = 0 - value;
tmp = 0 - (xds_uint32_t) value;
}
else
tmp = (xds_uint32_t) value;
((xds_uint8_t *)buffer)[0] = (tmp >> 24) & 0x000000ff;
((xds_uint8_t *)buffer)[1] = (tmp >> 16) & 0x000000ff;
((xds_uint8_t *)buffer)[2] = (tmp >> 8) & 0x000000ff;
((xds_uint8_t *)buffer)[3] = (tmp >> 0) & 0x000000ff;
return XDS_OK;
}
int xdr_decode_int32(xds_t *xds, void *engine_context,
void *buffer, size_t buffer_size,
size_t *used_buffer_size, va_list *args)
{
xds_int32_t *value;
xds_uint32_t tmp;
xds_init_decoding_engine(4);
/* Get value and format it into the buffer. */
value = va_arg(*args, xds_int32_t *);
xds_check_parameter(value != NULL);
if (((xds_uint8_t *) buffer)[0] & 0x80) {
/* negative number */
tmp = ((xds_uint8_t *)buffer)[0];
tmp = tmp << 8;
tmp += ((xds_uint8_t *)buffer)[1];
tmp = tmp << 8;
tmp += ((xds_uint8_t *)buffer)[2];
tmp = tmp << 8;
tmp += ((xds_uint8_t *)buffer)[3];
tmp = 0 - tmp;
*value = 0 - (int32_t)tmp;
}
else {
/* positive number */
*value = ((xds_uint8_t *)buffer)[0];
*value = *value << 8;
*value += ((xds_uint8_t *)buffer)[1];
*value = *value << 8;
*value += ((xds_uint8_t *)buffer)[2];
*value = *value << 8;
*value += ((xds_uint8_t *)buffer)[3];
}
return XDS_OK;
}
/*
* Encode/decode unsigned 32-bit integer values.
*/
int xdr_encode_uint32(xds_t *xds, void *engine_context,
void *buffer, size_t buffer_size,
size_t *used_buffer_size, va_list *args)
{
xds_uint32_t value;
xds_init_encoding_engine(4);
/* Get value and format it into the buffer. */
value = va_arg(*args, xds_uint32_t);
((xds_uint8_t *)buffer)[0] = (value >> 24) & 0x000000ff;
((xds_uint8_t *)buffer)[1] = (value >> 16) & 0x000000ff;
((xds_uint8_t *)buffer)[2] = (value >> 8) & 0x000000ff;
((xds_uint8_t *)buffer)[3] = (value >> 0) & 0x000000ff;
return XDS_OK;
}
int xdr_decode_uint32(xds_t *xds, void *engine_context,
void *buffer, size_t buffer_size,
size_t *used_buffer_size, va_list *args)
{
xds_uint32_t *value;
xds_init_decoding_engine(4);
/* Get value and format it into the buffer. */
value = va_arg(*args, xds_uint32_t *);
xds_check_parameter(value != NULL);
*value = ((xds_uint8_t *)buffer)[0];
*value = *value << 8;
*value += ((xds_uint8_t *)buffer)[1];
*value = *value << 8;
*value += ((xds_uint8_t *)buffer)[2];
*value = *value << 8;
*value += ((xds_uint8_t *)buffer)[3];
return XDS_OK;
}
#ifdef XDS_HAVE_64_BIT_SUPPORT
/*
* Encode/decode signed 64-bit integer values.
*/
int xdr_encode_int64(xds_t *xds, void *engine_context,
void *buffer, size_t buffer_size,
size_t *used_buffer_size, va_list *args)
{
xds_uint64_t tmp;
xds_int64_t value;
xds_init_encoding_engine(8);
/* Get value and format it into the buffer. */
value = va_arg(*args, xds_uint64_t);
if (value < 0) {
value = 0 - value;
tmp = 0 - (xds_uint64_t)value;
}
else
tmp = (xds_uint64_t)value;
((xds_uint8_t *)buffer)[0] = (tmp >> 56) & 0x000000ff;
((xds_uint8_t *)buffer)[1] = (tmp >> 48) & 0x000000ff;
((xds_uint8_t *)buffer)[2] = (tmp >> 40) & 0x000000ff;
((xds_uint8_t *)buffer)[3] = (tmp >> 32) & 0x000000ff;
((xds_uint8_t *)buffer)[4] = (tmp >> 24) & 0x000000ff;
((xds_uint8_t *)buffer)[5] = (tmp >> 16) & 0x000000ff;
((xds_uint8_t *)buffer)[6] = (tmp >> 8) & 0x000000ff;
((xds_uint8_t *)buffer)[7] = (tmp >> 0) & 0x000000ff;
return XDS_OK;
}
int xdr_decode_int64(xds_t *xds, void *engine_context,
void *buffer, size_t buffer_size,
size_t *used_buffer_size, va_list *args)
{
xds_int64_t *value;
xds_uint64_t tmp;
xds_init_decoding_engine(8);
/* Get value and format it into the buffer. */
value = va_arg(*args, xds_int64_t *);
xds_check_parameter(value != NULL);
if (((xds_uint8_t *)buffer)[0] & 0x80) {
/* negative number */
tmp = ((xds_uint8_t *)buffer)[0];
tmp = tmp << 8;
tmp += ((xds_uint8_t *)buffer)[1];
tmp = tmp << 8;
tmp += ((xds_uint8_t *)buffer)[2];
tmp = tmp << 8;
tmp += ((xds_uint8_t *)buffer)[3];
tmp = tmp << 8;
tmp += ((xds_uint8_t *)buffer)[4];
tmp = tmp << 8;
tmp += ((xds_uint8_t *)buffer)[5];
tmp = tmp << 8;
tmp += ((xds_uint8_t *)buffer)[6];
tmp = tmp << 8;
tmp += ((xds_uint8_t *)buffer)[7];
tmp = 0 - tmp;
*value = 0 - (xds_int64_t)tmp;
}
else {
/* positive number */
*value = ((xds_uint8_t *)buffer)[0];
*value = *value << 8;
*value += ((xds_uint8_t *)buffer)[1];
*value = *value << 8;
*value += ((xds_uint8_t *)buffer)[2];
*value = *value << 8;
*value += ((xds_uint8_t *)buffer)[3];
*value = *value << 8;
*value += ((xds_uint8_t *)buffer)[4];
*value = *value << 8;
*value += ((xds_uint8_t *)buffer)[5];
*value = *value << 8;
*value += ((xds_uint8_t *)buffer)[6];
*value = *value << 8;
*value += ((xds_uint8_t *)buffer)[7];
}
return XDS_OK;
}
/*
* Encode/decode unsigned 64-bit integer values.
*/
int xdr_encode_uint64(xds_t *xds, void *engine_context,
void *buffer, size_t buffer_size,
size_t *used_buffer_size, va_list *args)
{
xds_uint64_t value;
xds_init_encoding_engine(8);
/* Get value and format it into the buffer. */
value = va_arg(*args, xds_uint64_t);
((xds_uint8_t *)buffer)[0] = (value >> 56) & 0x000000ff;
((xds_uint8_t *)buffer)[1] = (value >> 48) & 0x000000ff;
((xds_uint8_t *)buffer)[2] = (value >> 40) & 0x000000ff;
((xds_uint8_t *)buffer)[3] = (value >> 32) & 0x000000ff;
((xds_uint8_t *)buffer)[4] = (value >> 24) & 0x000000ff;
((xds_uint8_t *)buffer)[5] = (value >> 16) & 0x000000ff;
((xds_uint8_t *)buffer)[6] = (value >> 8) & 0x000000ff;
((xds_uint8_t *)buffer)[7] = (value >> 0) & 0x000000ff;
return XDS_OK;
}
int xdr_decode_uint64(xds_t *xds, void *engine_context,
void *buffer, size_t buffer_size,
size_t *used_buffer_size, va_list *args)
{
xds_uint64_t *value;
xds_init_decoding_engine(8);
/* Get value and format it into the buffer. */
value = va_arg(*args, xds_uint64_t *);
xds_check_parameter(value != NULL);
*value = ((xds_uint8_t *)buffer)[0];
*value = *value << 8;
*value += ((xds_uint8_t *)buffer)[1];
*value = *value << 8;
*value += ((xds_uint8_t *)buffer)[2];
*value = *value << 8;
*value += ((xds_uint8_t *)buffer)[3];
*value = *value << 8;
*value += ((xds_uint8_t *)buffer)[4];
*value = *value << 8;
*value += ((xds_uint8_t *)buffer)[5];
*value = *value << 8;
*value += ((xds_uint8_t *)buffer)[6];
*value = *value << 8;
*value += ((xds_uint8_t *)buffer)[7];
return XDS_OK;
}
#endif /* XDS_HAVE_64_BIT_SUPPORT */
/*
* Encode/decode floating point values.
*/
typedef struct
{
xds_uint8_t sign; /* :1 */
xds_uint32_t fraction; /* :23 */
xds_int8_t exponent; /* :8 */
}
myfloat_t;
static int float2myfloat(myfloat_t* new_num, float num)
{
size_t i;
float tmp;
/* Handle zero as a special case. */
if (num == 0.0)
{
new_num->sign = 0;
new_num->fraction = 0;
new_num->exponent = -127;
return 0;
}
/* Determine the sign of the number. */
if (num < 0.0)
{
new_num->sign = 1;
num = 0.0 - num;
}
else
new_num->sign = 0;
/* Canonify the number before we convert it. */
new_num->exponent = 0;
while (num < 1.0)
{
num *= 2.0;
--new_num->exponent;
}
/* Find the exponent. */
for (i = 0, tmp = 1.0; i <= 128; ++i, tmp *= 2.0)
{
if (tmp * 2.0 > num)
break;
}
if (i <= 128)
{
num = num / tmp - 1.0;
new_num->exponent += i;
}
else
return 1;
/* Calculate the fraction part. */
for (new_num->fraction = 0, i = 0; i < 23; ++i)
{
new_num->fraction *= 2.0;
if (num >= 1.0 / 2.0)
{
new_num->fraction += 1.0;
num = num * 2.0 - 1.0;
}
else
num *= 2.0;
}
return 0;
}
int xdr_encode_float(xds_t *xds, void *engine_context,
void *buffer, size_t buffer_size,
size_t *used_buffer_size, va_list *args)
{
myfloat_t value = { 0, 0, 0 };
xds_uint8_t tmp;
xds_init_encoding_engine(4);
/* Get value and format it into the structure. */
float2myfloat(&value, (float)va_arg(*args, double));
memset(buffer, 0, 4);
if (value.sign == 1)
((xds_uint8_t*)buffer)[0] |= 0x80;
tmp = value.exponent + 127;
((xds_uint8_t*)buffer)[0] |= tmp >> 1;
((xds_uint8_t*)buffer)[1] |= (tmp & 0x01) << 7;
((xds_uint8_t*)buffer)[1] |= (xds_uint8_t)((value.fraction & 0x7fffff) >> 16);
((xds_uint8_t*)buffer)[2] |= (xds_uint8_t)((value.fraction & 0x00ffff) >> 8);
((xds_uint8_t*)buffer)[3] |= (xds_uint8_t)((value.fraction & 0x0000ff) >> 0);
return XDS_OK;
}
int xdr_decode_float(xds_t *xds, void *engine_context,
void *buffer, size_t buffer_size,
size_t *used_buffer_size, va_list *args)
{
float* value;
xds_uint32_t fraction;
xds_uint8_t exponent;
size_t i;
char sign;
xds_init_decoding_engine(4);
value = va_arg(*args, float*);
*value = 0.0;
sign = (((xds_uint8_t*)buffer)[0] & 0x80) >> 7;
exponent = (((xds_uint8_t*)buffer)[0] & 0x7f) << 1;
exponent += (((xds_uint8_t*)buffer)[1] & 0x80) >> 7;
fraction = (((xds_uint8_t*)buffer)[1] & 0x7fffff) << 16;
fraction += ((xds_uint8_t*)buffer)[2] << 8;
fraction += ((xds_uint8_t*)buffer)[3];
if (fraction == 0 && exponent == 0)
return XDS_OK;
for (i = 23; i > 0; --i)
{
if ((fraction & 0x01) == 1)
*value += 1.0;
*value /= 2.0;
fraction /= 2.0;
}
*value += 1.0;
if (exponent > 127)
{
for (exponent -= 127; exponent > 0; --exponent)
*value *= 2.0;
}
else
{
for (exponent = 127 - exponent; exponent > 0; --exponent)
*value /= 2.0;
}
if (sign == 1)
*value = 0.0 - *value;
return XDS_OK;
}
/*
* Encode/decode double-precision floating point values.
*/
typedef struct
{
xds_uint8_t sign; /* :1 */
xds_uint64_t fraction; /* :52 */
xds_int16_t exponent; /* :11 */
}
mydouble_t;
static int double2mydouble(mydouble_t* new_num, double num)
{
size_t i;
double tmp;
/* Handle zero as a special case. */
if (num == 0.0)
{
new_num->sign = 0;
new_num->fraction = 0;
new_num->exponent = -1023;
return 0;
}
/* Determine the sign of the number. */
if (num < 0.0)
{
new_num->sign = 1;
num = 0.0 - num;
}
else
new_num->sign = 0;
/* Canonify the number before we convert it. */
new_num->exponent = 0;
while (num < 1.0)
{
num *= 2.0;
--new_num->exponent;
}
/* Find the exponent. */
for (i = 0, tmp = 1.0; i <= 1024; ++i, tmp *= 2.0)
{
if (tmp * 2.0 > num)
break;
}
if (i <= 1024)
{
num = num / tmp - 1.0;
new_num->exponent += i;
}
else
return 1;
/* Calculate the fraction part. */
for (new_num->fraction = 0, i = 0; i < 52; ++i)
{
new_num->fraction *= 2.0;
if (num >= 1.0 / 2.0)
{
new_num->fraction += 1.0;
num = num * 2.0 - 1.0;
}
else
num *= 2.0;
}
return 0;
}
int xdr_encode_double(xds_t *xds, void *engine_context,
void *buffer, size_t buffer_size,
size_t *used_buffer_size, va_list *args)
{
mydouble_t value = { 0, 0, 0 };
xds_uint16_t tmp;
xds_init_encoding_engine(8);
/* Get value and format it into the structure. */
double2mydouble(&value, va_arg(*args, double));
memset(buffer, 0, 8);
if (value.sign == 1)
((xds_uint8_t*)buffer)[0] |= 0x80;
tmp = value.exponent + 1023;
((xds_uint8_t*)buffer)[0] |= (tmp >> 4) & 0x7f;
((xds_uint8_t*)buffer)[1] |= (tmp & 0x0f) << 4;
((xds_uint8_t*)buffer)[1] |= (xds_uint8_t)((value.fraction & 0x0f000000000000) >> 48);
((xds_uint8_t*)buffer)[2] |= (xds_uint8_t)((value.fraction & 0x00ff0000000000) >> 40);
((xds_uint8_t*)buffer)[3] |= (xds_uint8_t)((value.fraction & 0x0000ff00000000) >> 32);
((xds_uint8_t*)buffer)[4] |= (xds_uint8_t)((value.fraction & 0x000000ff000000) >> 24);
((xds_uint8_t*)buffer)[5] |= (xds_uint8_t)((value.fraction & 0x00000000ff0000) >> 16);
((xds_uint8_t*)buffer)[6] |= (xds_uint8_t)((value.fraction & 0x0000000000ff00) >> 8);
((xds_uint8_t*)buffer)[7] |= (xds_uint8_t)((value.fraction & 0x000000000000ff) >> 0);
return XDS_OK;
}
int xdr_decode_double(xds_t *xds, void *engine_context,
void *buffer, size_t buffer_size,
size_t *used_buffer_size, va_list *args)
{
double* value;
xds_uint64_t fraction;
xds_uint16_t exponent;
size_t i;
char sign;
xds_init_decoding_engine(8);
value = va_arg(*args, double*);
*value = 0.0;
sign = (((xds_uint8_t*)buffer)[0] & 0x80) >> 7;
exponent = (((xds_uint8_t*)buffer)[0] & 0x7f) << 4;
exponent += (((xds_uint8_t*)buffer)[1] & 0xf0) >> 4;
fraction = (xds_uint64_t)((((xds_uint8_t*)buffer)[1] & 0x0f)) << 48;
fraction += (xds_uint64_t)(((xds_uint8_t*)buffer)[2]) << 40;
fraction += (xds_uint64_t)(((xds_uint8_t*)buffer)[3]) << 32;
fraction += (xds_uint64_t)(((xds_uint8_t*)buffer)[4]) << 24;
fraction += (xds_uint64_t)(((xds_uint8_t*)buffer)[5]) << 16;
fraction += (xds_uint64_t)(((xds_uint8_t*)buffer)[6]) << 8;
fraction += (xds_uint64_t)(((xds_uint8_t*)buffer)[7]) << 0;
if (fraction == 0 && exponent == 0)
return XDS_OK;
for (i = 52; i > 0; --i)
{
if ((fraction & 0x01) == 1)
*value += 1.0;
*value /= 2.0;
fraction /= 2.0;
}
*value += 1.0;
if (exponent > 1023)
{
for (exponent -= 1023; exponent > 0; --exponent)
*value *= 2.0;
}
else
{
for (exponent = 1023 - exponent; exponent > 0; --exponent)
*value /= 2.0;
}
if (sign == 1)
*value = 0.0 - *value;
return XDS_OK;
}
/*
* Encode/decode NUL-terminated character strings.
*/
int xdr_encode_string(xds_t *xds, void *engine_context,
void *buffer, size_t buffer_size,
size_t *used_buffer_size, va_list *args)
{
char *p;
size_t p_len;
size_t padding;
xds_init_encoding_engine(4);
/* Get value from stack and calculate the correct amount of padding. */
p = va_arg(*args, char *);
xds_check_parameter(p != NULL);
p_len = strlen(p);
padding = (4 - (p_len & 0x03)) & 0x03;
assert((p_len + padding) % 4 == 0);
/* We need (4 + p_len + padding) bytes in the buffer to format our
parameter. If we don't have them, return an underflow error. */
*used_buffer_size = 4 + p_len + padding;
if (buffer_size < *used_buffer_size)
return XDS_ERR_OVERFLOW;
/* Format the values into the buffer. */
((xds_uint8_t *)buffer)[0] = (p_len >> 24) & 0x000000ff;
((xds_uint8_t *)buffer)[1] = (p_len >> 16) & 0x000000ff;
((xds_uint8_t *)buffer)[2] = (p_len >> 8) & 0x000000ff;
((xds_uint8_t *)buffer)[3] = (p_len >> 0) & 0x000000ff;
memmove((xds_uint8_t *)buffer + 4, p, p_len);
memset((xds_uint8_t *)buffer + 4 + p_len, 0, padding);
return XDS_OK;
}
int xdr_decode_string(xds_t *xds, void *engine_context,
void *buffer, size_t buffer_size,
size_t *used_buffer_size, va_list *args)
{
char **p;
size_t p_len;
size_t padding;
xds_init_decoding_engine(4);
/* Get value. */
p = va_arg(*args, char **);
xds_check_parameter(p != NULL);
/* Read the size of the message. */
p_len = ((xds_uint8_t *)buffer)[0];
p_len = p_len << 8;
p_len += ((xds_uint8_t *)buffer)[1];
p_len = p_len << 8;
p_len += ((xds_uint8_t *)buffer)[2];
p_len = p_len << 8;
p_len += ((xds_uint8_t *)buffer)[3];
/* Calculate padding. */
padding = (4 - (p_len & 0x03)) & 0x03;
/* Do we have enough data? */
*used_buffer_size = 4 + p_len + padding;
if (buffer_size < *used_buffer_size)
return XDS_ERR_UNDERFLOW;
/* Allocate buffer for the data. */
*p = (char *)malloc(p_len + 1);
if (*p == NULL)
return XDS_ERR_NO_MEM;
/* Copy data into the buffer. */
memmove(*p, (xds_uint8_t *)buffer + 4, p_len);
(*p)[p_len] = '\0';
return XDS_OK;
}
/*
* Encode/decode octet streams.
*/
int xdr_encode_octetstream(xds_t *xds, void *engine_context,
void *buffer, size_t buffer_size,
size_t *used_buffer_size, va_list *args)
{
xds_uint8_t *p;
size_t p_len;
size_t padding;
xds_init_encoding_engine(4);
/* Get value from stack and calculate the correct amount of padding. */
p = (xds_uint8_t *) va_arg(*args, void *);
xds_check_parameter(p != NULL);
p_len = va_arg(*args, size_t);
padding = (4 - (p_len & 0x03)) & 0x03;
assert((p_len + padding) % 4 == 0);
/* We need (4 + p_len + padding) bytes in the buffer to format our
parameter. If we don't have them, return an underflow error. */
*used_buffer_size = 4 + p_len + padding;
if (buffer_size < *used_buffer_size)
return XDS_ERR_OVERFLOW;
/* Format the values into the buffer. */
((xds_uint8_t *)buffer)[0] = (p_len >> 24) & 0x000000ff;
((xds_uint8_t *)buffer)[1] = (p_len >> 16) & 0x000000ff;
((xds_uint8_t *)buffer)[2] = (p_len >> 8) & 0x000000ff;
((xds_uint8_t *)buffer)[3] = (p_len >> 0) & 0x000000ff;
memmove((xds_uint8_t *) buffer + 4, p, p_len);
memset((xds_uint8_t *) buffer + 4 + p_len, 0, padding);
return XDS_OK;
}
int xdr_decode_octetstream(xds_t *xds, void *engine_context,
void *buffer, size_t buffer_size,
size_t *used_buffer_size, va_list *args)
{
void **p;
size_t *p_len;
size_t padding;
xds_init_decoding_engine(4);
p = va_arg(*args, void **);
p_len = va_arg(*args, size_t *);
xds_check_parameter(p != NULL);
xds_check_parameter(p_len != NULL);
/* Read the size of the message. */
*p_len = ((xds_uint8_t *)buffer)[0];
*p_len = *p_len << 8;
*p_len += ((xds_uint8_t *)buffer)[1];
*p_len = *p_len << 8;
*p_len += ((xds_uint8_t *)buffer)[2];
*p_len = *p_len << 8;
*p_len += ((xds_uint8_t *)buffer)[3];
/* Calculate padding. */
padding = (4 - (*p_len & 0x03)) & 0x03;
/* Do we have enough data? */
*used_buffer_size = 4 + *p_len + padding;
if (buffer_size < *used_buffer_size)
return XDS_ERR_UNDERFLOW;
/* Allocate buffer for the data. */
*p = malloc(*p_len);
if (*p == NULL)
return XDS_ERR_NO_MEM;
/* Copy data into the buffer. */
memmove(*p, (xds_uint8_t *) buffer + 4, *p_len);
return XDS_OK;
}
