network-bluetooth.html

FreeBSD安装说明概述 FreeBSD 提供了一个以文字为主

        pin     "1234";
      }
</pre>

<p>There is no limitation on PIN codes (except length). Some devices (for example
Bluetooth headsets) may have a fixed PIN code built in. The <var class="OPTION">-d</var>
switch forces the <span class="CITEREFENTRY"><span
class="REFENTRYTITLE">hcsecd</span>(8)</span> daemon to stay in the foreground, so it is
easy to see what is happening. Set the remote device to receive pairing and initiate the
Bluetooth connection to the remote device. The remote device should say that pairing was
accepted, and request the PIN code. Enter the same PIN code as you have in <tt
class="FILENAME">hcsecd.conf</tt>. Now your PC and the remote device are paired.
Alternatively, you can initiate pairing on the remote device. Below in the sample <tt
class="COMMAND">hcsecd</tt> output.</p>

<pre class="PROGRAMLISTING">
hcsecd[16484]: Got Link_Key_Request event from 'ubt0hci', remote bdaddr 0:80:37:29:19:a4
hcsecd[16484]: Found matching entry, remote bdaddr 0:80:37:29:19:a4, name 'Pav's T39', link key doesn't exist
hcsecd[16484]: Sending Link_Key_Negative_Reply to 'ubt0hci' for remote bdaddr 0:80:37:29:19:a4
hcsecd[16484]: Got PIN_Code_Request event from 'ubt0hci', remote bdaddr 0:80:37:29:19:a4
hcsecd[16484]: Found matching entry, remote bdaddr 0:80:37:29:19:a4, name 'Pav's T39', PIN code exists
hcsecd[16484]: Sending PIN_Code_Reply to 'ubt0hci' for remote bdaddr 0:80:37:29:19:a4
</pre>
</div>

<div class="SECT2">
<h2 class="SECT2"><a id="AEN25866" name="AEN25866">19.4.7. Service Discovery Protocol
(SDP)</a></h2>

<p>The Service Discovery Protocol (SDP) provides the means for client applications to
discover the existence of services provided by server applications as well as the
attributes of those services. The attributes of a service include the type or class of
service offered and the mechanism or protocol information needed to utilize the
service.</p>

<p>SDP involves communication between a SDP server and a SDP client. The server maintains
a list of service records that describe the characteristics of services associated with
the server. Each service record contains information about a single service. A client may
retrieve information from a service record maintained by the SDP server by issuing a SDP
request. If the client, or an application associated with the client, decides to use a
service, it must open a separate connection to the service provider in order to utilize
the service. SDP provides a mechanism for discovering services and their attributes, but
it does not provide a mechanism for utilizing those services.</p>

<p>Normally, a SDP client searches for services based on some desired characteristics of
the services. However, there are times when it is desirable to discover which types of
services are described by an SDP server's service records without any a priori
information about the services. This process of looking for any offered services is
called <span class="emphasis"><i class="EMPHASIS">browsing</i></span>.</p>

<p>Currently Bluetooth SDP server and client are implemented in a third-party package <b
class="APPLICATION">sdp-1.5</b> that can be downloaded from <a
href="http://www.geocities.com/m_evmenkin/" target="_top">here</a>. The <b
class="APPLICATION">sdptool</b> is a command line SDP client. The following example shows
how to perform a SDP browse query.</p>

<pre class="SCREEN">
<samp class="PROMPT">#</samp> <kbd
class="USERINPUT">sdptool browse 00:80:37:29:19:a4</kbd>
Browsing 00:80:37:29:19:A4 ...
Service Name: Dial-up Networking
Protocol Descriptor List:
 "L2CAP" (0x0100)
 "RFCOMM" (0x0003)
   Channel: 1

Service Name: Fax
Protocol Descriptor List:
 "L2CAP" (0x0100)
 "RFCOMM" (0x0003)
   Channel: 2

Service Name: Voice gateway
Service Class ID List:
 "Headset Audio Gateway" (0x1112)
 "Generic Audio" (0x1203)
Protocol Descriptor List:
 "L2CAP" (0x0100)
 "RFCOMM" (0x0003)
   Channel: 3
</pre>

<p>... and so on. Note that each service has a list of attributes (RFCOMM channel for
example). Depending on the service you might need to make a note of some of the
attributes. Some Bluetooth implementations do not support service browsing and may return
an empty list. In this case it is possible to search for the specific service. The
example below shows how to search for the OBEX Object Push (OPUSH) service.</p>

<pre class="SCREEN">
<samp class="PROMPT">#</samp> <kbd
class="USERINPUT">sdptool search --bdaddr 00:07:e0:00:0b:ca OPUSH</kbd>
</pre>

<p>Offering services on FreeBSD to Bluetooth clients is done with the <b
class="APPLICATION">sdpd</b> server.</p>

<pre class="SCREEN">
<samp class="PROMPT">#</samp> <kbd class="USERINPUT">sdpd</kbd>
</pre>

<p>The <b class="APPLICATION">sdptool</b> is also used to register a service with the
local SDP server. The example below shows how to register the Network Access with PPP
(LAN) service. Note that some services require attributes (RFCOMM channel for
example).</p>

<pre class="SCREEN">
<samp class="PROMPT">#</samp> <kbd class="USERINPUT">sdptool add --channel=7 LAN</kbd>
</pre>

<p>The list of services registered with local SDP server can be obtained by issuing SDP
browse query to a ``special'' BD_ADDR.</p>

<pre class="SCREEN">
<samp class="PROMPT">#</samp> <kbd
class="USERINPUT">sdptool browse ff:ff:ff:00:00:00</kbd>
</pre>
</div>

<div class="SECT2">
<h2 class="SECT2"><a id="AEN25898" name="AEN25898">19.4.8. Dial-Up Networking (DUN) and
Network Access with PPP (LAN) Profiles</a></h2>

<p>The Dial-Up Networking (DUN) profile is mostly used with modems and cellular phones.
The scenarios covered by this profile are the following:</p>

<ul>
<li>
<p>use of a cellular phone or modem by a computer as a wireless modem for connecting to a
dial-up internet access server, or using other dial-up services;</p>
</li>

<li>
<p>use of a cellular phone or modem by a computer to receive data calls.</p>
</li>
</ul>

<p>Network Access with PPP (LAN) profile can be used in the following situations:</p>

<ul>
<li>
<p>LAN access for a single Bluetooth device;</p>
</li>

<li>
<p>LAN access for multiple Bluetooth devices;</p>
</li>

<li>
<p>PC to PC (using PPP networking over serial cable emulation).</p>
</li>
</ul>

<p>In FreeBSD both profiles are implemented with <span class="CITEREFENTRY"><span
class="REFENTRYTITLE">ppp</span>(8)</span> and <span class="CITEREFENTRY"><span
class="REFENTRYTITLE">rfcomm_pppd</span>(8)</span> - a wrapper that converts RFCOMM
Bluetooth connection into something PPP can operate with. Before any profile can be used,
a new PPP label in <tt class="FILENAME">/etc/ppp/ppp.conf</tt> must be created. Consult
<span class="CITEREFENTRY"><span class="REFENTRYTITLE">rfcomm_pppd</span>(8)</span>
manual page for examples.</p>

<p>In the following example <span class="CITEREFENTRY"><span
class="REFENTRYTITLE">rfcomm_pppd</span>(8)</span> will be used to open RFCOMM connection
to remote device with BD_ADDR 00:80:37:29:19:a4 on DUN RFCOMM channel. The actual RFCOMM
channel number will be obtained from the remote device via SDP. It is possible to specify
RFCOMM channel by hand, and in this case <span class="CITEREFENTRY"><span
class="REFENTRYTITLE">rfcomm_pppd</span>(8)</span> will not perform SDP query. Use <b
class="APPLICATION">sdptool</b> to find out RFCOMM channel on the remote device.</p>

<pre class="SCREEN">
<samp class="PROMPT">#</samp> <kbd
class="USERINPUT">rfcomm_pppd -a 00:80:37:29:19:a4 -c -C dun -l rfcomm-dialup</kbd>
</pre>

<p>In order to provide Network Access with PPP (LAN) service <b
class="APPLICATION">sdpd</b> server must be running. It is also required to register LAN
service with the local SDP server. Note that LAN service requires RFCOMM channel
attribute. A new entry for LAN clients must be created in <tt
class="FILENAME">/etc/ppp/ppp.conf</tt> file. Consult <span class="CITEREFENTRY"><span
class="REFENTRYTITLE">rfcomm_pppd</span>(8)</span> manual page for examples. Finally,
RFCOMM PPP server must be running and listening on the same RFCOMM channel as registered
with the local SDP server. The example below shows how to start RFCOMM PPP server.</p>

<pre class="SCREEN">
<samp class="PROMPT">#</samp> <kbd
class="USERINPUT">rfcomm_pppd -s -C 7 -l rfcomm-server</kbd>
</pre>
</div>

<div class="SECT2">
<h2 class="SECT2"><a id="AEN25947" name="AEN25947">19.4.9. OBEX Push (OPUSH)
Profile</a></h2>

<p>OBEX is a widely used protocol for simple file transfers between mobile devices. Its
main use is in infrared communication, where it is used for generic file transfers
between notebooks or Palm handhelds, and for sending business cards or calendar entries
between cellular phones and other devices with PIM applications.</p>

<p>The OBEX server and client are implemented as a third-party package <b
class="APPLICATION">obexapp-1.0</b> that can be downloaded from <a
href="http://www.geocities.com/m_evmenkin/" target="_top">here</a>. The package requires
the <b class="APPLICATION">openobex</b> library (included) and the <a
href="http://www.FreeBSD.org/cgi/url.cgi?ports/devel/glib12/pkg-descr"><tt
class="FILENAME">devel/glib12</tt></a> port. Note that <b class="APPLICATION">obexapp</b>
does not require root privileges to operate.</p>

<p>OBEX client is used to push and/or pull objects from the OBEX server. An object can,
for example, be a business card or an appointment. The OBEX client can obtain RFCOMM
channel number from the remote device via SDP. This can be done by specifying service
name instead of RFCOMM channel number. Supported service names are: IrMC, FTRN and OPUSH.
It is possible to specify RFCOMM channel as a number. Below is an example of an OBEX
session, where device information object is pulled from the cellular phone, and a new
object (business card) is pushed into the phone's directory.</p>

<pre class="SCREEN">
<samp class="PROMPT">%</samp> <kbd
class="USERINPUT">obexapp -a 00:80:37:29:19:a4 -C IrMC</kbd>
obex&gt; get
get: remote file&gt; telecom/devinfo.txt
get: local file&gt; devinfo-t39.txt
Success, response: OK, Success (0x20)
obex&gt; put
put: local file&gt; new.vcf
put: remote file&gt; new.vcf
Success, response: OK, Success (0x20)
obex&gt; di
Success, response: OK, Success (0x20)
</pre>

<p>In order to provide OBEX Push service, <b class="APPLICATION">sdpd</b> server must be
running. It is also required to register OPUSH service with the local SDP server. Note
that OPUSH service requires RFCOMM channel attribute. A root folder, where all incoming
objects will be stored, must be created. The default path to the root folder is <tt
class="FILENAME">/var/spool/obex</tt>. Finally, OBEX server must be running and listening
on the same RFCOMM channel as registered with the local SDP server. The example below
shows how to start OBEX server.</p>

<pre class="SCREEN">
<samp class="PROMPT">#</samp> <kbd class="USERINPUT">obexapp -s -C 10</kbd>
</pre>
</div>

<div class="SECT2">
<h2 class="SECT2"><a id="AEN25966" name="AEN25966">19.4.10. Serial Port (SP)
Profile</a></h2>

<p>The Serial Port (SP) profile allows Bluetooth device to perform RS232 (or similar)
serial cable emulation. The scenario covered by this profile deals with legacy
applications using Bluetooth as a cable replacement, through a virtual serial port
abstraction.</p>

<p>The <span class="CITEREFENTRY"><span
class="REFENTRYTITLE">rfcomm_sppd</span>(1)</span> utility implements the Serial Port
profile. Pseudo tty is used as a virtual serial port abstraction. The example below shows
how to connect to a remote device Serial Port service. Note that you do not have to
specify RFCOMM channel - <span class="CITEREFENTRY"><span
class="REFENTRYTITLE">rfcomm_sppd</span>(1)</span> can obtain it from the remote device
via SDP. If you would like to override this, specify RFCOMM channel in the command
line.</p>

<pre class="SCREEN">
<samp class="PROMPT">#</samp> <kbd
class="USERINPUT">rfcomm_sppd -a 00:07:E0:00:0B:CA -t /dev/ttyp6</kbd>
rfcomm_sppd[94692]: Starting on /dev/ttyp6...
</pre>

<p>Once connected pseudo tty can be used as serial port.</p>

<pre class="SCREEN">
<samp class="PROMPT">#</samp> <kbd class="USERINPUT">cu -l ttyp6</kbd>
</pre>
</div>

<div class="SECT2">
<h2 class="SECT2"><a id="AEN25983" name="AEN25983">19.4.11. Troubleshooting</a></h2>

<div class="SECT3">
<h3 class="SECT3"><a id="AEN25985" name="AEN25985">19.4.11.1. A remote device cannot
connect</a></h3>

<p>Some older Bluetooth devices do not support role switching. By default, when FreeBSD
is accepting a new connection, it tries to perform role switch and become a master.
Devices, which do not support this will not be able to connect. Note the role switching
is performed when a new connection is being established, so it is not possible to ask the
remote device if it does support role switching. There is a HCI option to disable role
switching on the local side.</p>

<pre class="SCREEN">
<samp class="PROMPT">#</samp> <kbd
class="USERINPUT">hccontrol -n ubt0hci write_node_role_switch 0</kbd>
</pre>
</div>

<div class="SECT3">
<h3 class="SECT3"><a id="AEN25991" name="AEN25991">19.4.11.2. Something is going wrong,
can I see what exactly is happening?</a></h3>

<p>Yes, you can. Use the <b class="APPLICATION">hcidump-1.5</b> third-party package that
can be downloaded from from <a href="http://www.geocities.com/m_evmenkin/"
target="_top">here</a>. The <b class="APPLICATION">hcidump</b> utility is similar to
<span class="CITEREFENTRY"><span class="REFENTRYTITLE">tcpdump</span>(1)</span>. It can
used to display the content of the Bluetooth packets on the terminal and to dump the
Bluetooth packets to a file.</p>
</div>
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