| SDP_DATA(3) | Library Functions Manual | SDP_DATA(3) | 
sdp_match_uuid16 sdp_get_data
  sdp_get_attr sdp_get_uuid
  sdp_get_bool sdp_get_seq
  sdp_get_alt sdp_get_uint
  sdp_get_int sdp_get_str
  sdp_get_url sdp_put_data
  sdp_put_attr sdp_put_uuid
  sdp_put_uuid16 sdp_put_uuid32
  sdp_put_uuid128 sdp_put_bool
  sdp_put_uint sdp_put_uint8
  sdp_put_uint16 sdp_put_uint32
  sdp_put_uint64 sdp_put_int
  sdp_put_int8 sdp_put_int16
  sdp_put_int32 sdp_put_int64
  sdp_put_seq sdp_put_alt
  sdp_put_str sdp_put_url
  sdp_set_bool sdp_set_uint
  sdp_set_int sdp_set_seq
  sdp_set_alt sdp_data_size
  sdp_data_type sdp_data_valid
  sdp_data_print —
#include <sdp.h>
extern const uuid_t BLUETOOTH_BASE_UUID;
bool
  
  sdp_match_uuid16(sdp_data_t
    *data, uint16_t
    uuid);
bool
  
  sdp_get_data(sdp_data_t
    *data, sdp_data_t
    *value);
bool
  
  sdp_get_attr(sdp_data_t
    *data, uint16_t
    *attr, sdp_data_t
    *value);
bool
  
  sdp_get_uuid(sdp_data_t
    *data, uuid_t
    *uuid);
bool
  
  sdp_get_bool(sdp_data_t
    *data, bool
    *value);
bool
  
  sdp_get_seq(sdp_data_t
    *data, sdp_data_t
    *seq);
bool
  
  sdp_get_alt(sdp_data_t
    *data, sdp_data_t
    *alt);
bool
  
  sdp_get_uint(sdp_data_t
    *data, uintmax_t
    *value);
bool
  
  sdp_get_int(sdp_data_t
    *data, intmax_t
    *value);
bool
  
  sdp_get_str(sdp_data_t
    *data, char **str,
    size_t *length);
bool
  
  sdp_get_url(sdp_data_t
    *data, char **url,
    size_t *length);
bool
  
  sdp_put_data(sdp_data_t
    *data, sdp_data_t
    *value);
bool
  
  sdp_put_attr(sdp_data_t
    *data, uint16_t
    attr, sdp_data_t
    *value);
bool
  
  sdp_put_uuid(sdp_data_t
    *data, const uuid_t
    *value);
bool
  
  sdp_put_uuid16(sdp_data_t
    *data, uint16_t
    value);
bool
  
  sdp_put_uuid32(sdp_data_t
    *data, uint32_t
    value);
bool
  
  sdp_put_uuid128(sdp_data_t
    *data, const uuid_t
    *value);
bool
  
  sdp_put_bool(sdp_data_t
    *data, bool
  value);
bool
  
  sdp_put_uint(sdp_data_t
    *data, uintmax_t
    value);
bool
  
  sdp_put_uint8(sdp_data_t
    *data, uint8_t
    value);
bool
  
  sdp_put_uint16(sdp_data_t
    *data, uint16_t
    value);
bool
  
  sdp_put_uint32(sdp_data_t
    *data, uint32_t
    value);
bool
  
  sdp_put_uint64(sdp_data_t
    *data, uint64_t
    value);
bool
  
  sdp_put_int(sdp_data_t
    *data, intmax_t
    value);
bool
  
  sdp_put_int8(sdp_data_t
    *data, int8_t
    value);
bool
  
  sdp_put_int16(sdp_data_t
    *data, int16_t
    value);
bool
  
  sdp_put_int32(sdp_data_t
    *data, int32_t
    value);
bool
  
  sdp_put_int64(sdp_data_t
    *data, int64_t
    value);
bool
  
  sdp_put_seq(sdp_data_t
    *data, ssize_t
    length);
bool
  
  sdp_put_alt(sdp_data_t
    *data, ssize_t
    length);
bool
  
  sdp_put_str(sdp_data_t
    *data, const char
    *str, ssize_t
    length);
bool
  
  sdp_put_url(sdp_data_t
    *data, const char
    *url, ssize_t
    length);
bool
  
  sdp_set_bool(const
    sdp_data_t *data, bool
    value);
bool
  
  sdp_set_uint(const
    sdp_data_t *data,
    uintmax_t value);
bool
  
  sdp_set_int(const
    sdp_data_t *data,
    intmax_t value);
bool
  
  sdp_set_seq(const
    sdp_data_t *data, ssize_t
    length);
ssize_t
  
  sdp_data_size(const
    sdp_data_t *data);
int
  
  sdp_data_type(const
    sdp_data_t *data);
bool
  
  sdp_data_valid(const
    sdp_data_t *data);
void
  
  sdp_data_print(const
    sdp_data_t *data, int
    indent);
typedef struct {
	uint8_t *next;
	uint8_t *end;
} sdp_data_t;
Where next points to the next available byte, and end points to the first address past end of the data area, such that “end = next + length”.
The SDP data consists of byte streams describing data elements, where a data element is a typed data representation consisting of a header field and a data field. The header field consists of type and size descriptors, and the data field is a sequence of bytes whose length is specified in the size descriptor and whose content is specified by the type descriptor. For instance, the byte sequence “0x09, 0x01, 0x00” describes an 16-bit unsigned integer element (type 0x09) with value of 0x0100.
Data element types including signed and unsigned integers,
    boolean, string, sequence and alternative lists are defined in the
    <sdp.h> include file. See
    the “Service Discovery Protocol” chapters of the
    “Bluetooth Core Specifications” for more information.
To reduce the burden of storing and transferring 128-bit UUID
    values, a range of UUID values has been pre-allocated for assignment to
    often-used, registered purposes. The first UUID in this pre-allocated range
    is known as the “Bluetooth Base UUID”, defined in the
    “Bluetooth Assigned Numbers” document and declared in
    <sdp.h> as
    const uuid_t BLUETOOTH_BASE_UUID;
The data manipulation routines are arranged into major groups by function:
sdp_match_uuid16()true and the next field of
      the SDP data buffer will be advanced to the next element. Otherwise
      false will be returned.sdp_get_xxxx()true. Otherwise
      false will be returned. Note, these functions will
      not modify the data argument unless the correct type
      was found, and will update the data argument first
      to allow discarding in the case where a sdp_data_t
      was being returned.sdp_put_xxxx()false,
      otherwise true will be returned and the
      next field of the SDP data pointer will be advanced.
      In the case of sdp_put_seq() and
      sdp_put_alt(), the length
      argument may be -1, in which case the generated sequence header will
      describe all the remaining buffer space. For
      sdp_put_str() and
      sdp_put_url() the length
      argument may be -1 in which case the string pointer is treated as nul
      terminated.sdp_set_xxxx()false, otherwise true will
      be returned and the value updated. In the case of
      sdp_set_seq() and
      sdp_set_alt(), the length
      argument may be -1, in which case the sequence header will be adjusted to
      describe the entire data space where possible.sdp_data_xxxx()sdp_data_size() to return the size
      of the next data element, and sdp_data_type() to
      return the type of the next data element.
      sdp_data_valid() can be used to ensure that the
      entire data buffer contains valid SDP data elements and that all of the
      elements are contained exactly within the data buffer. Finally,
      sdp_data_print() will print the data buffer in
      human readable format.
	sdp_data_t rsp, val;
	uint16_t attr;
	uintmax_t handle;
	/* rsp contains remote response */
	while (sdp_get_attr(&rsp, &attr, &val)) {
		switch(attr) {
		case SDP_ATTR_SERVICE_RECORD_HANDLE:
			sdp_get_uint(&val, &handle);
			printf("ServiceRecordHandle: 0x%08x\n", handle);
			break;
		case SDP_ATTR_PROFILE_DESCRIPTOR_LIST:
			printf("ProfileDescriptorList:\n");
			sdp_data_print(&val, 0);
			break;
		default:
			printf("uninteresting attribute 0x%04x\n", attr);
			break;
		}
	}
The following code creates a ProtocolDataList attribute value for a service using the L2CAP and RFCOMM protocols and illustrates how to construct sequences of known and unknown length.
uint8_t buf[SIZE]; sdp_data_t seq; uint16_t psm; uint8_t channel; seq.next = buf; seq.end = buf + sizeof(buf); sdp_put_seq(&seq, -1); sdp_put_seq(&seq, 6); sdp_put_uuid16(&seq, SDP_UUID_PROTOCOL_L2CAP); sdp_put_uint16(&seq, psm); sdp_put_seq(&seq, 5); sdp_put_uuid16(&seq, SDP_UUID_PROTOCOL_RFCOMM); sdp_put_uint8(&seq, channel); seq.end = seq.next; seq.next = buf; sdp_set_seq(&seq, -1);
Note that although SIZE is assumed to be
    large enough to contain the entire sequence in this case, the
    sdp_put_xxxx() routines will not overflow the buffer
    area or write partial data.
The encoded data stream will be stored in a space efficient manner
    where possible. In the above example, it is known that the data element
    sequence containing the L2CAP UUID will be 8 bytes long overall since the
    container length of 6 can be stored in a single byte. But, because the value
    of SIZE is unknown, the overall length of the
    ProtocolDataList may vary depending if 8, 16 or 32 bits were needed to
    represent the original buffer size. sdp_set_seq()
    will only modify the content, not the size of the header.
The “Service Discovery Protocol” section of the Bluetooth Core specifications, available at http://www.bluetooth.com/
| January 15, 2011 | NetBSD 10.0 |