bluez/attrib/att.c
Anderson Lizardo 22cf3b76d1 attrib: Remove unnecessary checks for PDU length on ATT encoding
Both userspace and kernel enforce a minimum ATT MTU of 23 octets, which
is also used as minimum size for buffers passed to ATT encoding
functions. Therefore, it is unnecessary to perform these checks on ATT
requests that are guaranteed to fit into 23 octets.

Also document ATT parameter lengths where a constant is being used for
calculating the PDU length.
2014-01-11 18:56:03 +02:00

1134 lines
22 KiB
C

/*
*
* BlueZ - Bluetooth protocol stack for Linux
*
* Copyright (C) 2010 Nokia Corporation
* Copyright (C) 2010 Marcel Holtmann <marcel@holtmann.org>
*
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <errno.h>
#include <stdint.h>
#include <stdlib.h>
#include <bluetooth/bluetooth.h>
#include <glib.h>
#include "lib/uuid.h"
#include "att.h"
const char *att_ecode2str(uint8_t status)
{
switch (status) {
case ATT_ECODE_INVALID_HANDLE:
return "Invalid handle";
case ATT_ECODE_READ_NOT_PERM:
return "Attribute can't be read";
case ATT_ECODE_WRITE_NOT_PERM:
return "Attribute can't be written";
case ATT_ECODE_INVALID_PDU:
return "Attribute PDU was invalid";
case ATT_ECODE_AUTHENTICATION:
return "Attribute requires authentication before read/write";
case ATT_ECODE_REQ_NOT_SUPP:
return "Server doesn't support the request received";
case ATT_ECODE_INVALID_OFFSET:
return "Offset past the end of the attribute";
case ATT_ECODE_AUTHORIZATION:
return "Attribute requires authorization before read/write";
case ATT_ECODE_PREP_QUEUE_FULL:
return "Too many prepare writes have been queued";
case ATT_ECODE_ATTR_NOT_FOUND:
return "No attribute found within the given range";
case ATT_ECODE_ATTR_NOT_LONG:
return "Attribute can't be read/written using Read Blob Req";
case ATT_ECODE_INSUFF_ENCR_KEY_SIZE:
return "Encryption Key Size is insufficient";
case ATT_ECODE_INVAL_ATTR_VALUE_LEN:
return "Attribute value length is invalid";
case ATT_ECODE_UNLIKELY:
return "Request attribute has encountered an unlikely error";
case ATT_ECODE_INSUFF_ENC:
return "Encryption required before read/write";
case ATT_ECODE_UNSUPP_GRP_TYPE:
return "Attribute type is not a supported grouping attribute";
case ATT_ECODE_INSUFF_RESOURCES:
return "Insufficient Resources to complete the request";
case ATT_ECODE_IO:
return "Internal application error: I/O";
case ATT_ECODE_TIMEOUT:
return "A timeout occured";
case ATT_ECODE_ABORTED:
return "The operation was aborted";
default:
return "Unexpected error code";
}
}
void att_data_list_free(struct att_data_list *list)
{
if (list == NULL)
return;
if (list->data) {
int i;
for (i = 0; i < list->num; i++)
g_free(list->data[i]);
}
g_free(list->data);
g_free(list);
}
struct att_data_list *att_data_list_alloc(uint16_t num, uint16_t len)
{
struct att_data_list *list;
int i;
if (len > UINT8_MAX)
return NULL;
list = g_new0(struct att_data_list, 1);
list->len = len;
list->num = num;
list->data = g_malloc0(sizeof(uint8_t *) * num);
for (i = 0; i < num; i++)
list->data[i] = g_malloc0(sizeof(uint8_t) * len);
return list;
}
uint16_t enc_read_by_grp_req(uint16_t start, uint16_t end, bt_uuid_t *uuid,
uint8_t *pdu, size_t len)
{
uint16_t uuid_len;
if (!uuid)
return 0;
if (uuid->type == BT_UUID16)
uuid_len = 2;
else if (uuid->type == BT_UUID128)
uuid_len = 16;
else
return 0;
/* Attribute Opcode (1 octet) */
pdu[0] = ATT_OP_READ_BY_GROUP_REQ;
/* Starting Handle (2 octets) */
att_put_u16(start, &pdu[1]);
/* Ending Handle (2 octets) */
att_put_u16(end, &pdu[3]);
/* Attribute Group Type (2 or 16 octet UUID) */
att_put_uuid(*uuid, &pdu[5]);
return 5 + uuid_len;
}
uint16_t dec_read_by_grp_req(const uint8_t *pdu, size_t len, uint16_t *start,
uint16_t *end, bt_uuid_t *uuid)
{
const size_t min_len = sizeof(pdu[0]) + sizeof(*start) + sizeof(*end);
if (pdu == NULL)
return 0;
if (start == NULL || end == NULL || uuid == NULL)
return 0;
if (pdu[0] != ATT_OP_READ_BY_GROUP_REQ)
return 0;
if (len < min_len + 2)
return 0;
*start = att_get_u16(&pdu[1]);
*end = att_get_u16(&pdu[3]);
if (len == min_len + 2)
*uuid = att_get_uuid16(&pdu[5]);
else
*uuid = att_get_uuid128(&pdu[5]);
return len;
}
uint16_t enc_read_by_grp_resp(struct att_data_list *list, uint8_t *pdu,
size_t len)
{
int i;
uint16_t w;
uint8_t *ptr;
if (list == NULL)
return 0;
if (len < list->len + sizeof(uint8_t) * 2)
return 0;
pdu[0] = ATT_OP_READ_BY_GROUP_RESP;
pdu[1] = list->len;
ptr = &pdu[2];
for (i = 0, w = 2; i < list->num && w + list->len <= len; i++) {
memcpy(ptr, list->data[i], list->len);
ptr += list->len;
w += list->len;
}
return w;
}
struct att_data_list *dec_read_by_grp_resp(const uint8_t *pdu, size_t len)
{
struct att_data_list *list;
const uint8_t *ptr;
uint16_t elen, num;
int i;
if (pdu[0] != ATT_OP_READ_BY_GROUP_RESP)
return NULL;
elen = pdu[1];
num = (len - 2) / elen;
list = att_data_list_alloc(num, elen);
if (list == NULL)
return NULL;
ptr = &pdu[2];
for (i = 0; i < num; i++) {
memcpy(list->data[i], ptr, list->len);
ptr += list->len;
}
return list;
}
uint16_t enc_find_by_type_req(uint16_t start, uint16_t end, bt_uuid_t *uuid,
const uint8_t *value, size_t vlen,
uint8_t *pdu, size_t len)
{
uint16_t min_len = sizeof(pdu[0]) + sizeof(start) + sizeof(end) +
sizeof(uint16_t);
if (pdu == NULL)
return 0;
if (!uuid)
return 0;
if (uuid->type != BT_UUID16)
return 0;
if (vlen > len - min_len)
vlen = len - min_len;
pdu[0] = ATT_OP_FIND_BY_TYPE_REQ;
att_put_u16(start, &pdu[1]);
att_put_u16(end, &pdu[3]);
att_put_uuid16(*uuid, &pdu[5]);
if (vlen > 0) {
memcpy(&pdu[7], value, vlen);
return min_len + vlen;
}
return min_len;
}
uint16_t dec_find_by_type_req(const uint8_t *pdu, size_t len, uint16_t *start,
uint16_t *end, bt_uuid_t *uuid,
uint8_t *value, size_t *vlen)
{
size_t valuelen;
uint16_t min_len = sizeof(pdu[0]) + sizeof(*start) +
sizeof(*end) + sizeof(uint16_t);
if (pdu == NULL)
return 0;
if (len < min_len)
return 0;
if (pdu[0] != ATT_OP_FIND_BY_TYPE_REQ)
return 0;
/* First requested handle number */
if (start)
*start = att_get_u16(&pdu[1]);
/* Last requested handle number */
if (end)
*end = att_get_u16(&pdu[3]);
/* Always UUID16 */
if (uuid)
*uuid = att_get_uuid16(&pdu[5]);
valuelen = len - min_len;
/* Attribute value to find */
if (valuelen > 0 && value)
memcpy(value, pdu + min_len, valuelen);
if (vlen)
*vlen = valuelen;
return len;
}
uint16_t enc_find_by_type_resp(GSList *matches, uint8_t *pdu, size_t len)
{
GSList *l;
uint16_t offset;
if (!pdu)
return 0;
pdu[0] = ATT_OP_FIND_BY_TYPE_RESP;
for (l = matches, offset = 1;
l && len >= (offset + sizeof(uint16_t) * 2);
l = l->next, offset += sizeof(uint16_t) * 2) {
struct att_range *range = l->data;
att_put_u16(range->start, &pdu[offset]);
att_put_u16(range->end, &pdu[offset + 2]);
}
return offset;
}
GSList *dec_find_by_type_resp(const uint8_t *pdu, size_t len)
{
struct att_range *range;
GSList *matches;
off_t offset;
if (pdu == NULL || len < 5)
return NULL;
if (pdu[0] != ATT_OP_FIND_BY_TYPE_RESP)
return NULL;
for (offset = 1, matches = NULL;
len >= (offset + sizeof(uint16_t) * 2);
offset += sizeof(uint16_t) * 2) {
range = g_new0(struct att_range, 1);
range->start = att_get_u16(&pdu[offset]);
range->end = att_get_u16(&pdu[offset + 2]);
matches = g_slist_append(matches, range);
}
return matches;
}
uint16_t enc_read_by_type_req(uint16_t start, uint16_t end, bt_uuid_t *uuid,
uint8_t *pdu, size_t len)
{
uint16_t uuid_len;
if (!uuid)
return 0;
if (uuid->type == BT_UUID16)
uuid_len = 2;
else if (uuid->type == BT_UUID128)
uuid_len = 16;
else
return 0;
/* Attribute Opcode (1 octet) */
pdu[0] = ATT_OP_READ_BY_TYPE_REQ;
/* Starting Handle (2 octets) */
att_put_u16(start, &pdu[1]);
/* Ending Handle (2 octets) */
att_put_u16(end, &pdu[3]);
/* Attribute Type (2 or 16 octet UUID) */
att_put_uuid(*uuid, &pdu[5]);
return 5 + uuid_len;
}
uint16_t dec_read_by_type_req(const uint8_t *pdu, size_t len, uint16_t *start,
uint16_t *end, bt_uuid_t *uuid)
{
const size_t min_len = sizeof(pdu[0]) + sizeof(*start) + sizeof(*end);
if (pdu == NULL)
return 0;
if (start == NULL || end == NULL || uuid == NULL)
return 0;
if (len < min_len + 2)
return 0;
if (pdu[0] != ATT_OP_READ_BY_TYPE_REQ)
return 0;
*start = att_get_u16(&pdu[1]);
*end = att_get_u16(&pdu[3]);
if (len == min_len + 2)
*uuid = att_get_uuid16(&pdu[5]);
else
*uuid = att_get_uuid128(&pdu[5]);
return len;
}
uint16_t enc_read_by_type_resp(struct att_data_list *list, uint8_t *pdu,
size_t len)
{
uint8_t *ptr;
size_t i, w, l;
if (list == NULL)
return 0;
if (pdu == NULL)
return 0;
l = MIN(len - 2, list->len);
pdu[0] = ATT_OP_READ_BY_TYPE_RESP;
pdu[1] = l;
ptr = &pdu[2];
for (i = 0, w = 2; i < list->num && w + l <= len; i++) {
memcpy(ptr, list->data[i], l);
ptr += l;
w += l;
}
return w;
}
struct att_data_list *dec_read_by_type_resp(const uint8_t *pdu, size_t len)
{
struct att_data_list *list;
const uint8_t *ptr;
uint16_t elen, num;
int i;
if (pdu[0] != ATT_OP_READ_BY_TYPE_RESP)
return NULL;
elen = pdu[1];
num = (len - 2) / elen;
list = att_data_list_alloc(num, elen);
if (list == NULL)
return NULL;
ptr = &pdu[2];
for (i = 0; i < num; i++) {
memcpy(list->data[i], ptr, list->len);
ptr += list->len;
}
return list;
}
uint16_t enc_write_cmd(uint16_t handle, const uint8_t *value, size_t vlen,
uint8_t *pdu, size_t len)
{
const uint16_t min_len = sizeof(pdu[0]) + sizeof(handle);
if (pdu == NULL)
return 0;
if (vlen > len - min_len)
vlen = len - min_len;
pdu[0] = ATT_OP_WRITE_CMD;
att_put_u16(handle, &pdu[1]);
if (vlen > 0) {
memcpy(&pdu[3], value, vlen);
return min_len + vlen;
}
return min_len;
}
uint16_t dec_write_cmd(const uint8_t *pdu, size_t len, uint16_t *handle,
uint8_t *value, size_t *vlen)
{
const uint16_t min_len = sizeof(pdu[0]) + sizeof(*handle);
if (pdu == NULL)
return 0;
if (value == NULL || vlen == NULL || handle == NULL)
return 0;
if (len < min_len)
return 0;
if (pdu[0] != ATT_OP_WRITE_CMD)
return 0;
*handle = att_get_u16(&pdu[1]);
memcpy(value, pdu + min_len, len - min_len);
*vlen = len - min_len;
return len;
}
uint16_t enc_write_req(uint16_t handle, const uint8_t *value, size_t vlen,
uint8_t *pdu, size_t len)
{
const uint16_t min_len = sizeof(pdu[0]) + sizeof(handle);
if (pdu == NULL)
return 0;
if (vlen > len - min_len)
vlen = len - min_len;
pdu[0] = ATT_OP_WRITE_REQ;
att_put_u16(handle, &pdu[1]);
if (vlen > 0) {
memcpy(&pdu[3], value, vlen);
return min_len + vlen;
}
return min_len;
}
uint16_t dec_write_req(const uint8_t *pdu, size_t len, uint16_t *handle,
uint8_t *value, size_t *vlen)
{
const uint16_t min_len = sizeof(pdu[0]) + sizeof(*handle);
if (pdu == NULL)
return 0;
if (value == NULL || vlen == NULL || handle == NULL)
return 0;
if (len < min_len)
return 0;
if (pdu[0] != ATT_OP_WRITE_REQ)
return 0;
*handle = att_get_u16(&pdu[1]);
*vlen = len - min_len;
if (*vlen > 0)
memcpy(value, pdu + min_len, *vlen);
return len;
}
uint16_t enc_write_resp(uint8_t *pdu)
{
if (pdu == NULL)
return 0;
pdu[0] = ATT_OP_WRITE_RESP;
return sizeof(pdu[0]);
}
uint16_t dec_write_resp(const uint8_t *pdu, size_t len)
{
if (pdu == NULL)
return 0;
if (pdu[0] != ATT_OP_WRITE_RESP)
return 0;
return len;
}
uint16_t enc_read_req(uint16_t handle, uint8_t *pdu, size_t len)
{
if (pdu == NULL)
return 0;
/* Attribute Opcode (1 octet) */
pdu[0] = ATT_OP_READ_REQ;
/* Attribute Handle (2 octets) */
att_put_u16(handle, &pdu[1]);
return 3;
}
uint16_t enc_read_blob_req(uint16_t handle, uint16_t offset, uint8_t *pdu,
size_t len)
{
if (pdu == NULL)
return 0;
/* Attribute Opcode (1 octet) */
pdu[0] = ATT_OP_READ_BLOB_REQ;
/* Attribute Handle (2 octets) */
att_put_u16(handle, &pdu[1]);
/* Value Offset (2 octets) */
att_put_u16(offset, &pdu[3]);
return 5;
}
uint16_t dec_read_req(const uint8_t *pdu, size_t len, uint16_t *handle)
{
const uint16_t min_len = sizeof(pdu[0]) + sizeof(*handle);
if (pdu == NULL)
return 0;
if (handle == NULL)
return 0;
if (len < min_len)
return 0;
if (pdu[0] != ATT_OP_READ_REQ)
return 0;
*handle = att_get_u16(&pdu[1]);
return min_len;
}
uint16_t dec_read_blob_req(const uint8_t *pdu, size_t len, uint16_t *handle,
uint16_t *offset)
{
const uint16_t min_len = sizeof(pdu[0]) + sizeof(*handle) +
sizeof(*offset);
if (pdu == NULL)
return 0;
if (handle == NULL)
return 0;
if (offset == NULL)
return 0;
if (len < min_len)
return 0;
if (pdu[0] != ATT_OP_READ_BLOB_REQ)
return 0;
*handle = att_get_u16(&pdu[1]);
*offset = att_get_u16(&pdu[3]);
return min_len;
}
uint16_t enc_read_resp(uint8_t *value, size_t vlen, uint8_t *pdu, size_t len)
{
if (pdu == NULL)
return 0;
/* If the attribute value length is longer than the allowed PDU size,
* send only the octets that fit on the PDU. The remaining octets can
* be requested using the Read Blob Request. */
if (vlen > len - 1)
vlen = len - 1;
pdu[0] = ATT_OP_READ_RESP;
memcpy(pdu + 1, value, vlen);
return vlen + 1;
}
uint16_t enc_read_blob_resp(uint8_t *value, size_t vlen, uint16_t offset,
uint8_t *pdu, size_t len)
{
if (pdu == NULL)
return 0;
vlen -= offset;
if (vlen > len - 1)
vlen = len - 1;
pdu[0] = ATT_OP_READ_BLOB_RESP;
memcpy(pdu + 1, &value[offset], vlen);
return vlen + 1;
}
ssize_t dec_read_resp(const uint8_t *pdu, size_t len, uint8_t *value,
size_t vlen)
{
if (pdu == NULL)
return -EINVAL;
if (pdu[0] != ATT_OP_READ_RESP)
return -EINVAL;
if (value == NULL)
return len - 1;
if (vlen < (len - 1))
return -ENOBUFS;
memcpy(value, pdu + 1, len - 1);
return len - 1;
}
uint16_t enc_error_resp(uint8_t opcode, uint16_t handle, uint8_t status,
uint8_t *pdu, size_t len)
{
/* Attribute Opcode (1 octet) */
pdu[0] = ATT_OP_ERROR;
/* Request Opcode In Error (1 octet) */
pdu[1] = opcode;
/* Attribute Handle In Error (2 octets) */
att_put_u16(handle, &pdu[2]);
/* Error Code (1 octet) */
pdu[4] = status;
return 5;
}
uint16_t enc_find_info_req(uint16_t start, uint16_t end, uint8_t *pdu,
size_t len)
{
if (pdu == NULL)
return 0;
/* Attribute Opcode (1 octet) */
pdu[0] = ATT_OP_FIND_INFO_REQ;
/* Starting Handle (2 octets) */
att_put_u16(start, &pdu[1]);
/* Ending Handle (2 octets) */
att_put_u16(end, &pdu[3]);
return 5;
}
uint16_t dec_find_info_req(const uint8_t *pdu, size_t len, uint16_t *start,
uint16_t *end)
{
const uint16_t min_len = sizeof(pdu[0]) + sizeof(*start) + sizeof(*end);
if (pdu == NULL)
return 0;
if (len < min_len)
return 0;
if (start == NULL || end == NULL)
return 0;
if (pdu[0] != ATT_OP_FIND_INFO_REQ)
return 0;
*start = att_get_u16(&pdu[1]);
*end = att_get_u16(&pdu[3]);
return min_len;
}
uint16_t enc_find_info_resp(uint8_t format, struct att_data_list *list,
uint8_t *pdu, size_t len)
{
uint8_t *ptr;
size_t i, w;
if (pdu == NULL)
return 0;
if (list == NULL)
return 0;
if (len < list->len + sizeof(uint8_t) * 2)
return 0;
pdu[0] = ATT_OP_FIND_INFO_RESP;
pdu[1] = format;
ptr = (void *) &pdu[2];
for (i = 0, w = 2; i < list->num && w + list->len <= len; i++) {
memcpy(ptr, list->data[i], list->len);
ptr += list->len;
w += list->len;
}
return w;
}
struct att_data_list *dec_find_info_resp(const uint8_t *pdu, size_t len,
uint8_t *format)
{
struct att_data_list *list;
uint8_t *ptr;
uint16_t elen, num;
int i;
if (pdu == NULL)
return 0;
if (format == NULL)
return 0;
if (pdu[0] != ATT_OP_FIND_INFO_RESP)
return 0;
*format = pdu[1];
elen = sizeof(pdu[0]) + sizeof(*format);
if (*format == 0x01)
elen += 2;
else if (*format == 0x02)
elen += 16;
num = (len - 2) / elen;
ptr = (void *) &pdu[2];
list = att_data_list_alloc(num, elen);
if (list == NULL)
return NULL;
for (i = 0; i < num; i++) {
memcpy(list->data[i], ptr, list->len);
ptr += list->len;
}
return list;
}
uint16_t enc_notification(uint16_t handle, uint8_t *value, size_t vlen,
uint8_t *pdu, size_t len)
{
const uint16_t min_len = sizeof(pdu[0]) + sizeof(uint16_t);
if (pdu == NULL)
return 0;
if (len < (vlen + min_len))
return 0;
pdu[0] = ATT_OP_HANDLE_NOTIFY;
att_put_u16(handle, &pdu[1]);
memcpy(&pdu[3], value, vlen);
return vlen + min_len;
}
uint16_t enc_indication(uint16_t handle, uint8_t *value, size_t vlen,
uint8_t *pdu, size_t len)
{
const uint16_t min_len = sizeof(pdu[0]) + sizeof(uint16_t);
if (pdu == NULL)
return 0;
if (len < (vlen + min_len))
return 0;
pdu[0] = ATT_OP_HANDLE_IND;
att_put_u16(handle, &pdu[1]);
memcpy(&pdu[3], value, vlen);
return vlen + min_len;
}
uint16_t dec_indication(const uint8_t *pdu, size_t len, uint16_t *handle,
uint8_t *value, size_t vlen)
{
const uint16_t min_len = sizeof(pdu[0]) + sizeof(uint16_t);
uint16_t dlen;
if (pdu == NULL)
return 0;
if (pdu[0] != ATT_OP_HANDLE_IND)
return 0;
if (len < min_len)
return 0;
dlen = MIN(len - min_len, vlen);
if (handle)
*handle = att_get_u16(&pdu[1]);
memcpy(value, &pdu[3], dlen);
return dlen;
}
uint16_t enc_confirmation(uint8_t *pdu, size_t len)
{
if (pdu == NULL)
return 0;
/* Attribute Opcode (1 octet) */
pdu[0] = ATT_OP_HANDLE_CNF;
return 1;
}
uint16_t enc_mtu_req(uint16_t mtu, uint8_t *pdu, size_t len)
{
if (pdu == NULL)
return 0;
/* Attribute Opcode (1 octet) */
pdu[0] = ATT_OP_MTU_REQ;
/* Client Rx MTU (2 octets) */
att_put_u16(mtu, &pdu[1]);
return 3;
}
uint16_t dec_mtu_req(const uint8_t *pdu, size_t len, uint16_t *mtu)
{
const uint16_t min_len = sizeof(pdu[0]) + sizeof(*mtu);
if (pdu == NULL)
return 0;
if (mtu == NULL)
return 0;
if (len < min_len)
return 0;
if (pdu[0] != ATT_OP_MTU_REQ)
return 0;
*mtu = att_get_u16(&pdu[1]);
return min_len;
}
uint16_t enc_mtu_resp(uint16_t mtu, uint8_t *pdu, size_t len)
{
if (pdu == NULL)
return 0;
/* Attribute Opcode (1 octet) */
pdu[0] = ATT_OP_MTU_RESP;
/* Server Rx MTU (2 octets) */
att_put_u16(mtu, &pdu[1]);
return 3;
}
uint16_t dec_mtu_resp(const uint8_t *pdu, size_t len, uint16_t *mtu)
{
const uint16_t min_len = sizeof(pdu[0]) + sizeof(*mtu);
if (pdu == NULL)
return 0;
if (mtu == NULL)
return 0;
if (len < min_len)
return 0;
if (pdu[0] != ATT_OP_MTU_RESP)
return 0;
*mtu = att_get_u16(&pdu[1]);
return min_len;
}
uint16_t enc_prep_write_req(uint16_t handle, uint16_t offset,
const uint8_t *value, size_t vlen,
uint8_t *pdu, size_t len)
{
const uint16_t min_len = sizeof(pdu[0]) + sizeof(handle) +
sizeof(offset);
if (pdu == NULL)
return 0;
if (vlen > len - min_len)
vlen = len - min_len;
pdu[0] = ATT_OP_PREP_WRITE_REQ;
att_put_u16(handle, &pdu[1]);
att_put_u16(offset, &pdu[3]);
if (vlen > 0) {
memcpy(&pdu[5], value, vlen);
return min_len + vlen;
}
return min_len;
}
uint16_t dec_prep_write_req(const uint8_t *pdu, size_t len, uint16_t *handle,
uint16_t *offset, uint8_t *value, size_t *vlen)
{
const uint16_t min_len = sizeof(pdu[0]) + sizeof(*handle) +
sizeof(*offset);
if (pdu == NULL)
return 0;
if (handle == NULL || offset == NULL || value == NULL || vlen == NULL)
return 0;
if (len < min_len)
return 0;
if (pdu[0] != ATT_OP_PREP_WRITE_REQ)
return 0;
*handle = att_get_u16(&pdu[1]);
*offset = att_get_u16(&pdu[3]);
*vlen = len - min_len;
if (*vlen > 0)
memcpy(value, pdu + min_len, *vlen);
return len;
}
uint16_t enc_prep_write_resp(uint16_t handle, uint16_t offset,
const uint8_t *value, size_t vlen,
uint8_t *pdu, size_t len)
{
const uint16_t min_len = sizeof(pdu[0]) + sizeof(handle) +
sizeof(offset);
if (pdu == NULL)
return 0;
if (vlen > len - min_len)
vlen = len - min_len;
pdu[0] = ATT_OP_PREP_WRITE_RESP;
att_put_u16(handle, &pdu[1]);
att_put_u16(offset, &pdu[3]);
if (vlen > 0) {
memcpy(&pdu[5], value, vlen);
return min_len + vlen;
}
return min_len;
}
uint16_t dec_prep_write_resp(const uint8_t *pdu, size_t len, uint16_t *handle,
uint16_t *offset, uint8_t *value, size_t *vlen)
{
const uint16_t min_len = sizeof(pdu[0]) + sizeof(*handle) +
sizeof(*offset);
if (pdu == NULL)
return 0;
if (handle == NULL || offset == NULL || value == NULL || vlen == NULL)
return 0;
if (len < min_len)
return 0;
if (pdu[0] != ATT_OP_PREP_WRITE_REQ)
return 0;
*handle = att_get_u16(&pdu[1]);
*offset = att_get_u16(&pdu[3]);
*vlen = len - min_len;
if (*vlen > 0)
memcpy(value, pdu + min_len, *vlen);
return len;
}
uint16_t enc_exec_write_req(uint8_t flags, uint8_t *pdu, size_t len)
{
if (pdu == NULL)
return 0;
if (flags > 1)
return 0;
/* Attribute Opcode (1 octet) */
pdu[0] = ATT_OP_EXEC_WRITE_REQ;
/* Flags (1 octet) */
pdu[1] = flags;
return 2;
}
uint16_t dec_exec_write_req(const uint8_t *pdu, size_t len, uint8_t *flags)
{
const uint16_t min_len = sizeof(pdu[0]) + sizeof(*flags);
if (pdu == NULL)
return 0;
if (flags == NULL)
return 0;
if (len < min_len)
return 0;
if (pdu[0] != ATT_OP_EXEC_WRITE_REQ)
return 0;
*flags = pdu[1];
return min_len;
}
uint16_t enc_exec_write_resp(uint8_t *pdu)
{
if (pdu == NULL)
return 0;
/* Attribute Opcode (1 octet) */
pdu[0] = ATT_OP_EXEC_WRITE_RESP;
return 1;
}
uint16_t dec_exec_write_resp(const uint8_t *pdu, size_t len)
{
const uint16_t min_len = sizeof(pdu[0]);
if (pdu == NULL)
return 0;
if (len < min_len)
return 0;
if (pdu[0] != ATT_OP_EXEC_WRITE_RESP)
return 0;
return len;
}