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esp-idf/components/bt/bluedroid/stack/sdp/sdp_server.c

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/******************************************************************************
*
* Copyright (C) 1999-2012 Broadcom Corporation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at:
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
******************************************************************************/
/******************************************************************************
*
* This file contains functions that handle the SDP server functions.
* This is mainly dealing with client requests
*
******************************************************************************/
//#include <stdlib.h>
#include <string.h>
//#include <stdio.h>
#include "bt_types.h"
#include "allocator.h"
#include "btu.h"
#include "bt_defs.h"
#include "l2cdefs.h"
#include "hcidefs.h"
#include "hcimsgs.h"
#include "sdp_api.h"
#include "sdpint.h"
#if SDP_SERVER_ENABLED == TRUE
/* Maximum number of bytes to reserve out of SDP MTU for response data */
#define SDP_MAX_SERVICE_RSPHDR_LEN 12
#define SDP_MAX_SERVATTR_RSPHDR_LEN 10
#define SDP_MAX_ATTR_RSPHDR_LEN 10
/********************************************************************************/
/* L O C A L F U N C T I O N P R O T O T Y P E S */
/********************************************************************************/
static void process_service_search (tCONN_CB *p_ccb, UINT16 trans_num,
UINT16 param_len, UINT8 *p_req,
UINT8 *p_req_end);
static void process_service_attr_req (tCONN_CB *p_ccb, UINT16 trans_num,
UINT16 param_len, UINT8 *p_req,
UINT8 *p_req_end);
static void process_service_search_attr_req (tCONN_CB *p_ccb, UINT16 trans_num,
UINT16 param_len, UINT8 *p_req,
UINT8 *p_req_end);
/********************************************************************************/
/* E R R O R T E X T S T R I N G S */
/* */
/* The default is to have no text string, but we allow the strings to be */
/* configured in target.h if people want them. */
/********************************************************************************/
#ifndef SDP_TEXT_BAD_HEADER
#define SDP_TEXT_BAD_HEADER NULL
#endif
#ifndef SDP_TEXT_BAD_PDU
#define SDP_TEXT_BAD_PDU NULL
#endif
#ifndef SDP_TEXT_BAD_UUID_LIST
#define SDP_TEXT_BAD_UUID_LIST NULL
#endif
#ifndef SDP_TEXT_BAD_HANDLE
#define SDP_TEXT_BAD_HANDLE NULL
#endif
#ifndef SDP_TEXT_BAD_ATTR_LIST
#define SDP_TEXT_BAD_ATTR_LIST NULL
#endif
#ifndef SDP_TEXT_BAD_CONT_LEN
#define SDP_TEXT_BAD_CONT_LEN NULL
#endif
#ifndef SDP_TEXT_BAD_CONT_INX
#define SDP_TEXT_BAD_CONT_INX NULL
#endif
#ifndef SDP_TEXT_BAD_MAX_RECORDS_LIST
#define SDP_TEXT_BAD_MAX_RECORDS_LIST NULL
#endif
/*******************************************************************************
**
** Function sdp_server_handle_client_req
**
** Description This is the main dispatcher of the SDP server. It is called
** when any data is received from L2CAP, and dispatches the
** request to the appropriate handler.
**
** Returns void
**
*******************************************************************************/
void sdp_server_handle_client_req (tCONN_CB *p_ccb, BT_HDR *p_msg)
{
UINT8 *p_req = (UINT8 *) (p_msg + 1) + p_msg->offset;
UINT8 *p_req_end = p_req + p_msg->len;
UINT8 pdu_id;
UINT16 trans_num, param_len;
/* Start inactivity timer */
btu_start_timer (&p_ccb->timer_entry, BTU_TTYPE_SDP, SDP_INACT_TIMEOUT);
/* The first byte in the message is the pdu type */
pdu_id = *p_req++;
/* Extract the transaction number and parameter length */
BE_STREAM_TO_UINT16 (trans_num, p_req);
BE_STREAM_TO_UINT16 (param_len, p_req);
if ((p_req + param_len) != p_req_end) {
sdpu_build_n_send_error (p_ccb, trans_num, SDP_INVALID_PDU_SIZE, SDP_TEXT_BAD_HEADER);
return;
}
switch (pdu_id) {
case SDP_PDU_SERVICE_SEARCH_REQ:
process_service_search (p_ccb, trans_num, param_len, p_req, p_req_end);
break;
case SDP_PDU_SERVICE_ATTR_REQ:
process_service_attr_req (p_ccb, trans_num, param_len, p_req, p_req_end);
break;
case SDP_PDU_SERVICE_SEARCH_ATTR_REQ:
process_service_search_attr_req (p_ccb, trans_num, param_len, p_req, p_req_end);
break;
default:
sdpu_build_n_send_error (p_ccb, trans_num, SDP_INVALID_REQ_SYNTAX, SDP_TEXT_BAD_PDU);
SDP_TRACE_WARNING ("SDP - server got unknown PDU: 0x%x\n", pdu_id);
break;
}
}
/*******************************************************************************
**
** Function process_service_search
**
** Description This function handles a service search request from the
** client. It builds a reply message with info from the database,
** and sends the reply back to the client.
**
** Returns void
**
*******************************************************************************/
static void process_service_search (tCONN_CB *p_ccb, UINT16 trans_num,
UINT16 param_len, UINT8 *p_req,
UINT8 *p_req_end)
{
UINT16 max_replies, cur_handles, rem_handles, cont_offset;
tSDP_UUID_SEQ uid_seq;
UINT8 *p_rsp, *p_rsp_start, *p_rsp_param_len;
UINT16 rsp_param_len, num_rsp_handles, xx;
UINT32 rsp_handles[SDP_MAX_RECORDS] = {0};
tSDP_RECORD *p_rec = NULL;
BT_HDR *p_buf;
BOOLEAN is_cont = FALSE;
UNUSED(p_req_end);
p_req = sdpu_extract_uid_seq (p_req, param_len, &uid_seq);
if ((!p_req) || (!uid_seq.num_uids)) {
sdpu_build_n_send_error (p_ccb, trans_num, SDP_INVALID_REQ_SYNTAX, SDP_TEXT_BAD_UUID_LIST);
return;
}
/* Get the max replies we can send. Cap it at our max anyways. */
BE_STREAM_TO_UINT16 (max_replies, p_req);
if (max_replies > SDP_MAX_RECORDS) {
max_replies = SDP_MAX_RECORDS;
}
if ((!p_req) || (p_req > p_req_end)) {
sdpu_build_n_send_error (p_ccb, trans_num, SDP_INVALID_REQ_SYNTAX, SDP_TEXT_BAD_MAX_RECORDS_LIST);
return;
}
/* Get a list of handles that match the UUIDs given to us */
for (num_rsp_handles = 0; num_rsp_handles < max_replies; ) {
p_rec = sdp_db_service_search (p_rec, &uid_seq);
if (p_rec) {
rsp_handles[num_rsp_handles++] = p_rec->record_handle;
} else {
break;
}
}
/* Check if this is a continuation request */
if (*p_req) {
if (*p_req++ != SDP_CONTINUATION_LEN || (p_req >= p_req_end)) {
sdpu_build_n_send_error (p_ccb, trans_num, SDP_INVALID_CONT_STATE,
SDP_TEXT_BAD_CONT_LEN);
return;
}
BE_STREAM_TO_UINT16 (cont_offset, p_req);
if (cont_offset != p_ccb->cont_offset || num_rsp_handles < cont_offset) {
sdpu_build_n_send_error (p_ccb, trans_num, SDP_INVALID_CONT_STATE,
SDP_TEXT_BAD_CONT_INX);
return;
}
rem_handles = num_rsp_handles - cont_offset; /* extract the remaining handles */
} else {
rem_handles = num_rsp_handles;
cont_offset = 0;
p_ccb->cont_offset = 0;
}
/* Calculate how many handles will fit in one PDU */
cur_handles = (UINT16)((p_ccb->rem_mtu_size - SDP_MAX_SERVICE_RSPHDR_LEN) / 4);
if (rem_handles <= cur_handles) {
cur_handles = rem_handles;
} else { /* Continuation is set */
p_ccb->cont_offset += cur_handles;
is_cont = TRUE;
}
/* Get a buffer to use to build the response */
if ((p_buf = (BT_HDR *)osi_malloc(SDP_DATA_BUF_SIZE)) == NULL) {
SDP_TRACE_ERROR ("SDP - no buf for search rsp\n");
return;
}
p_buf->offset = L2CAP_MIN_OFFSET;
p_rsp = p_rsp_start = (UINT8 *)(p_buf + 1) + L2CAP_MIN_OFFSET;
/* Start building a rsponse */
UINT8_TO_BE_STREAM (p_rsp, SDP_PDU_SERVICE_SEARCH_RSP);
UINT16_TO_BE_STREAM (p_rsp, trans_num);
/* Skip the length, we need to add it at the end */
p_rsp_param_len = p_rsp;
p_rsp += 2;
/* Put in total and current number of handles, and handles themselves */
UINT16_TO_BE_STREAM (p_rsp, num_rsp_handles);
UINT16_TO_BE_STREAM (p_rsp, cur_handles);
/* SDP_TRACE_DEBUG("SDP Service Rsp: tothdl %d, curhdlr %d, start %d, end %d, cont %d",
num_rsp_handles, cur_handles, cont_offset,
cont_offset + cur_handles-1, is_cont); */
for (xx = cont_offset; xx < cont_offset + cur_handles; xx++) {
UINT32_TO_BE_STREAM (p_rsp, rsp_handles[xx]);
}
if (is_cont) {
UINT8_TO_BE_STREAM (p_rsp, SDP_CONTINUATION_LEN);
UINT16_TO_BE_STREAM (p_rsp, p_ccb->cont_offset);
} else {
UINT8_TO_BE_STREAM (p_rsp, 0);
}
/* Go back and put the parameter length into the buffer */
rsp_param_len = p_rsp - p_rsp_param_len - 2;
UINT16_TO_BE_STREAM (p_rsp_param_len, rsp_param_len);
/* Set the length of the SDP data in the buffer */
p_buf->len = p_rsp - p_rsp_start;
/* Send the buffer through L2CAP */
L2CA_DataWrite (p_ccb->connection_id, p_buf);
}
/*******************************************************************************
**
** Function process_service_attr_req
**
** Description This function handles an attribute request from the client.
** It builds a reply message with info from the database,
** and sends the reply back to the client.
**
** Returns void
**
*******************************************************************************/
static void process_service_attr_req (tCONN_CB *p_ccb, UINT16 trans_num,
UINT16 param_len, UINT8 *p_req,
UINT8 *p_req_end)
{
UINT16 max_list_len, len_to_send, cont_offset;
INT16 rem_len;
tSDP_ATTR_SEQ attr_seq, attr_seq_sav;
UINT8 *p_rsp, *p_rsp_start, *p_rsp_param_len;
UINT16 rsp_param_len, xx;
UINT32 rec_handle;
tSDP_RECORD *p_rec;
tSDP_ATTRIBUTE *p_attr;
BT_HDR *p_buf;
BOOLEAN is_cont = FALSE;
UINT16 attr_len;
/* Extract the record handle */
BE_STREAM_TO_UINT32 (rec_handle, p_req);
if (p_req > p_req_end) {
sdpu_build_n_send_error (p_ccb, trans_num, SDP_INVALID_SERV_REC_HDL, SDP_TEXT_BAD_HANDLE);
return;
}
/* Get the max list length we can send. Cap it at MTU size minus overhead */
BE_STREAM_TO_UINT16 (max_list_len, p_req);
if (max_list_len > (p_ccb->rem_mtu_size - SDP_MAX_ATTR_RSPHDR_LEN)) {
max_list_len = p_ccb->rem_mtu_size - SDP_MAX_ATTR_RSPHDR_LEN;
}
p_req = sdpu_extract_attr_seq (p_req, param_len, &attr_seq);
if ((!p_req) || (!attr_seq.num_attr) || (p_req > p_req_end)) {
sdpu_build_n_send_error (p_ccb, trans_num, SDP_INVALID_REQ_SYNTAX, SDP_TEXT_BAD_ATTR_LIST);
return;
}
memcpy(&attr_seq_sav, &attr_seq, sizeof(tSDP_ATTR_SEQ)) ;
/* Find a record with the record handle */
p_rec = sdp_db_find_record (rec_handle);
if (!p_rec) {
sdpu_build_n_send_error (p_ccb, trans_num, SDP_INVALID_SERV_REC_HDL, SDP_TEXT_BAD_HANDLE);
return;
}
/* Check if this is a continuation request */
if (*p_req) {
/* Free and reallocate buffer */
if (p_ccb->rsp_list) {
osi_free(p_ccb->rsp_list);
}
p_ccb->rsp_list = (UINT8 *)osi_malloc(max_list_len);
if (p_ccb->rsp_list == NULL) {
SDP_TRACE_ERROR("%s No scratch buf for attr rsp\n", __func__);
return;
}
if (*p_req++ != SDP_CONTINUATION_LEN) {
sdpu_build_n_send_error (p_ccb, trans_num, SDP_INVALID_CONT_STATE, SDP_TEXT_BAD_CONT_LEN);
return;
}
BE_STREAM_TO_UINT16 (cont_offset, p_req);
if (cont_offset != p_ccb->cont_offset) {
sdpu_build_n_send_error (p_ccb, trans_num, SDP_INVALID_CONT_STATE, SDP_TEXT_BAD_CONT_INX);
return;
}
if (!p_ccb->rsp_list) {
sdpu_build_n_send_error (p_ccb, trans_num, SDP_NO_RESOURCES, NULL);
return;
}
is_cont = TRUE;
/* Initialise for continuation response */
p_rsp = &p_ccb->rsp_list[0];
attr_seq.attr_entry[p_ccb->cont_info.next_attr_index].start = p_ccb->cont_info.next_attr_start_id;
} else {
if (p_ccb->rsp_list) {
osi_free (p_ccb->rsp_list);
}
p_ccb->rsp_list = (UINT8 *)osi_malloc (max_list_len);
if (p_ccb->rsp_list == NULL) {
SDP_TRACE_ERROR ("SDP - no scratch buf for search rsp\n");
return;
}
p_ccb->cont_offset = 0;
p_rsp = &p_ccb->rsp_list[3]; /* Leave space for data elem descr */
/* Reset continuation parameters in p_ccb */
p_ccb->cont_info.prev_sdp_rec = NULL;
p_ccb->cont_info.next_attr_index = 0;
p_ccb->cont_info.attr_offset = 0;
}
/* Search for attributes that match the list given to us */
for (xx = p_ccb->cont_info.next_attr_index; xx < attr_seq.num_attr; xx++) {
p_attr = sdp_db_find_attr_in_rec (p_rec, attr_seq.attr_entry[xx].start, attr_seq.attr_entry[xx].end);
if (p_attr) {
/* Check if attribute fits. Assume 3-byte value type/length */
rem_len = max_list_len - (INT16) (p_rsp - &p_ccb->rsp_list[0]);
/* just in case */
if (rem_len <= 0) {
p_ccb->cont_info.next_attr_index = xx;
p_ccb->cont_info.next_attr_start_id = p_attr->id;
break;
}
attr_len = sdpu_get_attrib_entry_len(p_attr);
/* if there is a partial attribute pending to be sent */
if (p_ccb->cont_info.attr_offset) {
p_rsp = sdpu_build_partial_attrib_entry (p_rsp, p_attr, rem_len,
&p_ccb->cont_info.attr_offset);
/* If the partial attrib could not been fully added yet */
if (p_ccb->cont_info.attr_offset != attr_len) {
break;
} else { /* If the partial attrib has been added in full by now */
p_ccb->cont_info.attr_offset = 0; /* reset attr_offset */
}
} else if (rem_len < attr_len) { /* Not enough space for attr... so add partially */
if (attr_len >= SDP_MAX_ATTR_LEN) {
SDP_TRACE_ERROR("SDP attr too big: max_list_len=%d,attr_len=%d\n", max_list_len, attr_len);
sdpu_build_n_send_error (p_ccb, trans_num, SDP_NO_RESOURCES, NULL);
return;
}
/* add the partial attribute if possible */
p_rsp = sdpu_build_partial_attrib_entry (p_rsp, p_attr, (UINT16)rem_len,
&p_ccb->cont_info.attr_offset);
p_ccb->cont_info.next_attr_index = xx;
p_ccb->cont_info.next_attr_start_id = p_attr->id;
break;
} else { /* build the whole attribute */
p_rsp = sdpu_build_attrib_entry (p_rsp, p_attr);
}
/* If doing a range, stick with this one till no more attributes found */
if (attr_seq.attr_entry[xx].start != attr_seq.attr_entry[xx].end) {
/* Update for next time through */
attr_seq.attr_entry[xx].start = p_attr->id + 1;
xx--;
}
}
}
/* If all the attributes have been accomodated in p_rsp,
reset next_attr_index */
if (xx == attr_seq.num_attr) {
p_ccb->cont_info.next_attr_index = 0;
}
len_to_send = (UINT16) (p_rsp - &p_ccb->rsp_list[0]);
cont_offset = 0;
if (!is_cont) {
p_ccb->list_len = sdpu_get_attrib_seq_len(p_rec, &attr_seq_sav) + 3;
/* Put in the sequence header (2 or 3 bytes) */
if (p_ccb->list_len > 255) {
p_ccb->rsp_list[0] = (UINT8) ((DATA_ELE_SEQ_DESC_TYPE << 3) | SIZE_IN_NEXT_WORD);
p_ccb->rsp_list[1] = (UINT8) ((p_ccb->list_len - 3) >> 8);
p_ccb->rsp_list[2] = (UINT8) (p_ccb->list_len - 3);
} else {
cont_offset = 1;
p_ccb->rsp_list[1] = (UINT8) ((DATA_ELE_SEQ_DESC_TYPE << 3) | SIZE_IN_NEXT_BYTE);
p_ccb->rsp_list[2] = (UINT8) (p_ccb->list_len - 3);
p_ccb->list_len--;
len_to_send--;
}
}
/* Get a buffer to use to build the response */
if ((p_buf = (BT_HDR *)osi_malloc(SDP_DATA_BUF_SIZE)) == NULL) {
SDP_TRACE_ERROR ("SDP - no buf for search rsp\n");
return;
}
p_buf->offset = L2CAP_MIN_OFFSET;
p_rsp = p_rsp_start = (UINT8 *)(p_buf + 1) + L2CAP_MIN_OFFSET;
/* Start building a rsponse */
UINT8_TO_BE_STREAM (p_rsp, SDP_PDU_SERVICE_ATTR_RSP);
UINT16_TO_BE_STREAM (p_rsp, trans_num);
/* Skip the parameter length, add it when we know the length */
p_rsp_param_len = p_rsp;
p_rsp += 2;
UINT16_TO_BE_STREAM (p_rsp, len_to_send);
memcpy (p_rsp, &p_ccb->rsp_list[cont_offset], len_to_send);
p_rsp += len_to_send;
p_ccb->cont_offset += len_to_send;
/* If anything left to send, continuation needed */
if (p_ccb->cont_offset < p_ccb->list_len) {
is_cont = TRUE;
UINT8_TO_BE_STREAM (p_rsp, SDP_CONTINUATION_LEN);
UINT16_TO_BE_STREAM (p_rsp, p_ccb->cont_offset);
} else {
UINT8_TO_BE_STREAM (p_rsp, 0);
}
/* Go back and put the parameter length into the buffer */
rsp_param_len = p_rsp - p_rsp_param_len - 2;
UINT16_TO_BE_STREAM (p_rsp_param_len, rsp_param_len);
/* Set the length of the SDP data in the buffer */
p_buf->len = p_rsp - p_rsp_start;
/* Send the buffer through L2CAP */
L2CA_DataWrite (p_ccb->connection_id, p_buf);
}
/*******************************************************************************
**
** Function process_service_search_attr_req
**
** Description This function handles a combined service search and attribute
** read request from the client. It builds a reply message with
** info from the database, and sends the reply back to the client.
**
** Returns void
**
*******************************************************************************/
static void process_service_search_attr_req (tCONN_CB *p_ccb, UINT16 trans_num,
UINT16 param_len, UINT8 *p_req,
UINT8 *p_req_end)
{
UINT16 max_list_len;
INT16 rem_len;
UINT16 len_to_send, cont_offset;
tSDP_UUID_SEQ uid_seq;
UINT8 *p_rsp, *p_rsp_start, *p_rsp_param_len;
UINT16 rsp_param_len, xx;
tSDP_RECORD *p_rec;
tSDP_ATTR_SEQ attr_seq, attr_seq_sav;
tSDP_ATTRIBUTE *p_attr;
BT_HDR *p_buf;
BOOLEAN maxxed_out = FALSE, is_cont = FALSE;
UINT8 *p_seq_start;
UINT16 seq_len, attr_len;
UNUSED(p_req_end);
/* Extract the UUID sequence to search for */
p_req = sdpu_extract_uid_seq (p_req, param_len, &uid_seq);
if ((!p_req) || (!uid_seq.num_uids)) {
sdpu_build_n_send_error (p_ccb, trans_num, SDP_INVALID_REQ_SYNTAX, SDP_TEXT_BAD_UUID_LIST);
return;
}
/* Get the max list length we can send. Cap it at our max list length. */
BE_STREAM_TO_UINT16 (max_list_len, p_req);
if (max_list_len > (p_ccb->rem_mtu_size - SDP_MAX_SERVATTR_RSPHDR_LEN)) {
max_list_len = p_ccb->rem_mtu_size - SDP_MAX_SERVATTR_RSPHDR_LEN;
}
p_req = sdpu_extract_attr_seq (p_req, param_len, &attr_seq);
if ((!p_req) || (!attr_seq.num_attr)) {
sdpu_build_n_send_error (p_ccb, trans_num, SDP_INVALID_REQ_SYNTAX, SDP_TEXT_BAD_ATTR_LIST);
return;
}
memcpy(&attr_seq_sav, &attr_seq, sizeof(tSDP_ATTR_SEQ)) ;
/* Check if this is a continuation request */
if (*p_req) {
/* Free and reallocate buffer */
if (p_ccb->rsp_list) {
osi_free (p_ccb->rsp_list);
}
p_ccb->rsp_list = (UINT8 *)osi_malloc (max_list_len);
if (p_ccb->rsp_list == NULL) {
SDP_TRACE_ERROR ("SDP - no scratch buf for search rsp\n");
return;
}
if (*p_req++ != SDP_CONTINUATION_LEN) {
sdpu_build_n_send_error (p_ccb, trans_num, SDP_INVALID_CONT_STATE, SDP_TEXT_BAD_CONT_LEN);
return;
}
BE_STREAM_TO_UINT16 (cont_offset, p_req);
if (cont_offset != p_ccb->cont_offset) {
sdpu_build_n_send_error (p_ccb, trans_num, SDP_INVALID_CONT_STATE, SDP_TEXT_BAD_CONT_INX);
return;
}
if (!p_ccb->rsp_list) {
sdpu_build_n_send_error (p_ccb, trans_num, SDP_NO_RESOURCES, NULL);
return;
}
is_cont = TRUE;
/* Initialise for continuation response */
p_rsp = &p_ccb->rsp_list[0];
attr_seq.attr_entry[p_ccb->cont_info.next_attr_index].start = p_ccb->cont_info.next_attr_start_id;
} else {
/* Get a scratch buffer to store response */
/* Free and reallocate if the earlier allocated buffer is small */
if (p_ccb->rsp_list) {
osi_free (p_ccb->rsp_list);
}
p_ccb->rsp_list = (UINT8 *)osi_malloc (max_list_len);
if (p_ccb->rsp_list == NULL) {
SDP_TRACE_ERROR ("SDP - no scratch buf for search rsp\n");
return;
}
p_ccb->cont_offset = 0;
p_rsp = &p_ccb->rsp_list[3]; /* Leave space for data elem descr */
/* Reset continuation parameters in p_ccb */
p_ccb->cont_info.prev_sdp_rec = NULL;
p_ccb->cont_info.next_attr_index = 0;
p_ccb->cont_info.last_attr_seq_desc_sent = FALSE;
p_ccb->cont_info.attr_offset = 0;
}
/* Get a list of handles that match the UUIDs given to us */
for (p_rec = sdp_db_service_search (p_ccb->cont_info.prev_sdp_rec, &uid_seq); p_rec; p_rec = sdp_db_service_search (p_rec, &uid_seq)) {
/* Allow space for attribute sequence type and length */
p_seq_start = p_rsp;
if (p_ccb->cont_info.last_attr_seq_desc_sent == FALSE) {
/* See if there is enough room to include a new service in the current response */
rem_len = max_list_len - (INT16) (p_rsp - &p_ccb->rsp_list[0]);
if (rem_len < 3) {
/* Not enough room. Update continuation info for next response */
p_ccb->cont_info.next_attr_index = 0;
p_ccb->cont_info.next_attr_start_id = attr_seq.attr_entry[0].start;
break;
}
p_rsp += 3;
}
/* Get a list of handles that match the UUIDs given to us */
for (xx = p_ccb->cont_info.next_attr_index; xx < attr_seq.num_attr; xx++) {
p_attr = sdp_db_find_attr_in_rec (p_rec, attr_seq.attr_entry[xx].start, attr_seq.attr_entry[xx].end);
if (p_attr) {
/* Check if attribute fits. Assume 3-byte value type/length */
rem_len = max_list_len - (INT16) (p_rsp - &p_ccb->rsp_list[0]);
/* just in case */
if (rem_len <= 0) {
p_ccb->cont_info.next_attr_index = xx;
p_ccb->cont_info.next_attr_start_id = p_attr->id;
maxxed_out = TRUE;
break;
}
attr_len = sdpu_get_attrib_entry_len(p_attr);
/* if there is a partial attribute pending to be sent */
if (p_ccb->cont_info.attr_offset) {
p_rsp = sdpu_build_partial_attrib_entry (p_rsp, p_attr, rem_len,
&p_ccb->cont_info.attr_offset);
/* If the partial attrib could not been fully added yet */
if (p_ccb->cont_info.attr_offset != attr_len) {
maxxed_out = TRUE;
break;
} else { /* If the partial attrib has been added in full by now */
p_ccb->cont_info.attr_offset = 0; /* reset attr_offset */
}
} else if (rem_len < attr_len) { /* Not enough space for attr... so add partially */
if (attr_len >= SDP_MAX_ATTR_LEN) {
SDP_TRACE_ERROR("SDP attr too big: max_list_len=%d,attr_len=%d\n", max_list_len, attr_len);
sdpu_build_n_send_error (p_ccb, trans_num, SDP_NO_RESOURCES, NULL);
return;
}
/* add the partial attribute if possible */
p_rsp = sdpu_build_partial_attrib_entry (p_rsp, p_attr, (UINT16)rem_len,
&p_ccb->cont_info.attr_offset);
p_ccb->cont_info.next_attr_index = xx;
p_ccb->cont_info.next_attr_start_id = p_attr->id;
maxxed_out = TRUE;
break;
} else { /* build the whole attribute */
p_rsp = sdpu_build_attrib_entry (p_rsp, p_attr);
}
/* If doing a range, stick with this one till no more attributes found */
if (attr_seq.attr_entry[xx].start != attr_seq.attr_entry[xx].end) {
/* Update for next time through */
attr_seq.attr_entry[xx].start = p_attr->id + 1;
xx--;
}
}
}
/* Go back and put the type and length into the buffer */
if (p_ccb->cont_info.last_attr_seq_desc_sent == FALSE) {
seq_len = sdpu_get_attrib_seq_len(p_rec, &attr_seq_sav);
if (seq_len != 0) {
UINT8_TO_BE_STREAM (p_seq_start, (DATA_ELE_SEQ_DESC_TYPE << 3) | SIZE_IN_NEXT_WORD);
UINT16_TO_BE_STREAM (p_seq_start, seq_len);
if (maxxed_out) {
p_ccb->cont_info.last_attr_seq_desc_sent = TRUE;
}
} else {
p_rsp = p_seq_start;
}
}
if (maxxed_out) {
break;
}
/* Restore the attr_seq to look for in the next sdp record */
memcpy(&attr_seq, &attr_seq_sav, sizeof(tSDP_ATTR_SEQ)) ;
/* Reset the next attr index */
p_ccb->cont_info.next_attr_index = 0;
p_ccb->cont_info.prev_sdp_rec = p_rec;
p_ccb->cont_info.last_attr_seq_desc_sent = FALSE;
}
/* response length */
len_to_send = (UINT16) (p_rsp - &p_ccb->rsp_list[0]);
cont_offset = 0;
// The current SDP server design has a critical flaw where it can run into an infinite
// request/response loop with the client. Here's the scenario:
// - client makes SDP request
// - server returns the first fragment of the response with a continuation token
// - an SDP record is deleted from the server
// - client issues another request with previous continuation token
// - server has nothing to send back because the record is unavailable but in the
// first fragment, it had specified more response bytes than are now available
// - server sends back no additional response bytes and returns the same continuation token
// - client issues another request with the continuation token, and the process repeats
//
// We work around this design flaw here by checking if we will make forward progress
// (i.e. we will send > 0 response bytes) on a continued request. If not, we must have
// run into the above situation and we tell the peer an error occurred.
//
// TODO(sharvil): rewrite SDP server.
if (is_cont && len_to_send == 0) {
sdpu_build_n_send_error(p_ccb, trans_num, SDP_INVALID_CONT_STATE, NULL);
return;
}
/* If first response, insert sequence header */
if (!is_cont) {
/* Get the total list length for requested uid and attribute sequence */
p_ccb->list_len = sdpu_get_list_len(&uid_seq, &attr_seq_sav) + 3;
/* Put in the sequence header (2 or 3 bytes) */
if (p_ccb->list_len > 255) {
p_ccb->rsp_list[0] = (UINT8) ((DATA_ELE_SEQ_DESC_TYPE << 3) | SIZE_IN_NEXT_WORD);
p_ccb->rsp_list[1] = (UINT8) ((p_ccb->list_len - 3) >> 8);
p_ccb->rsp_list[2] = (UINT8) (p_ccb->list_len - 3);
} else {
cont_offset = 1;
p_ccb->rsp_list[1] = (UINT8) ((DATA_ELE_SEQ_DESC_TYPE << 3) | SIZE_IN_NEXT_BYTE);
p_ccb->rsp_list[2] = (UINT8) (p_ccb->list_len - 3);
p_ccb->list_len--;
len_to_send--;
}
}
/* Get a buffer to use to build the response */
if ((p_buf = (BT_HDR *)osi_malloc(SDP_DATA_BUF_SIZE)) == NULL) {
SDP_TRACE_ERROR ("SDP - no buf for search rsp\n");
return;
}
p_buf->offset = L2CAP_MIN_OFFSET;
p_rsp = p_rsp_start = (UINT8 *)(p_buf + 1) + L2CAP_MIN_OFFSET;
/* Start building a rsponse */
UINT8_TO_BE_STREAM (p_rsp, SDP_PDU_SERVICE_SEARCH_ATTR_RSP);
UINT16_TO_BE_STREAM (p_rsp, trans_num);
/* Skip the parameter length, add it when we know the length */
p_rsp_param_len = p_rsp;
p_rsp += 2;
/* Stream the list length to send */
UINT16_TO_BE_STREAM (p_rsp, len_to_send);
/* copy from rsp_list to the actual buffer to be sent */
memcpy (p_rsp, &p_ccb->rsp_list[cont_offset], len_to_send);
p_rsp += len_to_send;
p_ccb->cont_offset += len_to_send;
/* If anything left to send, continuation needed */
if (p_ccb->cont_offset < p_ccb->list_len) {
is_cont = TRUE;
UINT8_TO_BE_STREAM (p_rsp, SDP_CONTINUATION_LEN);
UINT16_TO_BE_STREAM (p_rsp, p_ccb->cont_offset);
} else {
UINT8_TO_BE_STREAM (p_rsp, 0);
}
/* Go back and put the parameter length into the buffer */
rsp_param_len = p_rsp - p_rsp_param_len - 2;
UINT16_TO_BE_STREAM (p_rsp_param_len, rsp_param_len);
/* Set the length of the SDP data in the buffer */
p_buf->len = p_rsp - p_rsp_start;
/* Send the buffer through L2CAP */
L2CA_DataWrite (p_ccb->connection_id, p_buf);
}
#endif /* SDP_SERVER_ENABLED == TRUE */
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