rfcomm_pppd(8)

NAME

rfcomm_pppd - RFCOMM PPP daemon

SYNOPSIS

rfcomm_pppd -c [-dh] -a address -C channel -l label -u N
rfcomm_pppd -s [-dhS] [-a address] -C channel -l label

DESCRIPTION

The rfcomm_pppd daemon is a simple wrapper daemon that al

lows to use
standard ppp(8) on RFCOMM connection. It can operate in two

modes:
client and server.

In the client mode, rfcomm_pppd opens an RFCOMM connection

to the specified server's BD_ADRR and channel. Once RFCOMM connection

is established, rfcomm_pppd executes ppp(8) in -direct mode with the

specified
label. The ppp(8) in its turn operates over the RFCOMM con

nection just
like it would operate over the standard serial port thus al

lowing user to
``dial out'' and connect to the Internet.

In the server mode, rfcomm_pppd opens an RFCOMM socket and

listens for
incoming connections from remote clients. Once the new in

coming connection is accepted, rfcomm_pppd forks and executes ppp(8) in

-direct mode
with the specified label. The ppp(8) in its turn operates

over the
RFCOMM connection just like it would operate over the stan

dard serial
port thus providing network connectivity to remote clients.

The options are as follows:

-a address

In the client mode, this required option specifies

the address of
the remote RFCOMM server. In the server mode, this

option can be
used to specify the local address to listen on. By

default,
server will listen on ANY address. The address can

be specified
as BD_ADDR or name. If name was specified then the

rfcomm_pppd
utility will attempt to resolve the name via

bt_gethostbyname(3).

-C channel

In both client and server modes, this required op

tion specifies
RFCOMM channel to connect to or listen on. In the

server mode,
RFCOMM channel should be a number between 1 and 30.

In the
client mode, RFCOMM channel could either be a number

between 1
and 30 or a service name. Supported service names

are: DUN (for
DialUp Networking service) and LAN (for LAN Access

Using PPP service). If service name was specified instead of nu

meric RFCOMM
channel then rfcomm_pppd utility will try to obtain

RFCOMM channel for the service via Service Discovery Protocol.

-c Act as an RFCOMM client. This is the default mode.

-d Do not detach from the controlling terminal, i.e.,

run in fore

ground.

-h Display usage message and exit.

-l label

In both client and server modes, this required op

tion specifies
which ppp(8) label will be used.

-S In the server mode, register the Serial Port (SP)

service in

addition to the LAN Access Using PPP (LAN) service.

It appears
that some cell phones are using the so-called

``callback
mechanism''. In this scenario, the user is trying

to connect his
cell phone to the Internet, and user's host computer

is acting as
the gateway server. It seems that it is not possi

ble to tell the
phone to just connect and start using the LAN ser

vice. Instead,
the user's host computer must ``jump start'' the

phone by connecting to the phone's SP service. What happens

next is the
phone kills the existing connection and opens anoth

er connection
back to the user's host computer. The phone really

wants to use
LAN service, but for whatever reason it looks for

the SP service
on the user's host computer. This brain damaged be

havior was
reported for Nokia 6600 and Sony/Ericsson P900.

-s Act as an RFCOMM server.

-u N This option maps directly onto -unit ppp(8) command

line option

and tells rfcomm_pppd to instruct ppp(8) to only at

tempt to open
/dev/tunN. This option only works in the client

mode.

PPP CONFIGURATION

Important Notes on PPP Configuration

Special attention is required when adding new RFCOMM config

urations to
the existing PPP configuration. Please keep in mind that

PPP will always
execute commands in the ``default'' label of your

/etc/ppp/ppp.conf file.
Please make sure that the ``default'' label only contains

commands that
apply to every other label. If you need to use PPP for both

dialing out
and accepting incoming RFCOMM connections, please make sure

you have
moved all commands related to dialing out from the ``de

fault'' section
into an appropriate outgoing label.

RFCOMM Server

One of the typical examples is the LAN access. In this ex

ample, RFCOMM
connection is used as a null-modem connection between client

and server.
Both client and server will start talking PPP right after

RFCOMM connection was established.

rfcomm-server:

set timeout 0
set lqrperiod 10
set ifaddr 10.0.0.1 10.0.0.2 255.255.255.0
enable lqr
accept lqr
# Do not use PPP authentication. Assume that
# Bluetooth connection was authenticated already
disable pap
deny pap
disable chap
deny chap

RFCOMM Client

The rfcomm_pppd utility supports both LAN and DUN (Dial-Up

Networking)
access. The client's configuration for the LAN access is

very similar to
server's and might look like this.

rfcomm-client:

enable lqr
accept lqr
set dial
set timeout 0
disable iface-alias
set ifaddr 10.0.0.1/0 10.0.0.2/0 255.255.255.0

0.0.0.0
# Do not use PPP authentication. Assume that
# Bluetooth connection was authenticated already
deny pap
disable pap
deny chap
disable chap

The client's configuration for the DUN access is different.

In this scenario, the client gets connected to the virtual serial port

on the
server. To open a PPP session, client must dial a number.

Note that by
default ppp(8) will not execute any configured chat scripts.

The
force-scripts option can be used to override this behavior.

The example
of such configuration is shown below.

rfcomm-dialup:

# This is IMPORTANT option
enable force-scripts

# You might want to change these
set authname
set authkey
set phone "*99***1#"

# You might want to adjust dial string as well
set dial "ABORT BUSY ABORT NORRIER TIMEOUT 5
set login
set timeout 30
enable dns
resolv rewrite

set ifaddr 10.0.0.1/0 10.0.0.2/0 255.255.255.0

0.0.0.0
add default HISADDR

Note that by adjusting the initialization string, one can

make CSD (Circuit Switched Data), HSCSD (High Speed Circuit Switched Da

ta) or GPRS
(General Packet Radio Service) connection. The availability

of the particular connection type depends on the phone model and ser

vice plan activated on the phone.

EXIT STATUS EXAMPLES

rfcomm_pppd -s -a 00:01:02:03:04:05 -C 1 -l rfcomm

server

This command will start rfcomm_pppd in the server mode. The

RFCOMM

server will listen on local address 00:01:02:03:04:05 and

channel 1.
Once the incoming connection has been accepted, rfcomm_pppd

will execute
ppp(8) in -direct mode with ``rfcomm-server'' label.

rfcomm_pppd -c -a 00:01:02:03:04:05 -C 1 -l rfcomm

client

This command will start rfcomm_pppd in the client mode.

rfcomm_pppd will
try to connect to the RFCOMM server at 00:01:02:03:04:05 ad

dress and
channel 1. Once connected, the rfcomm_pppd will execute

ppp(8) in
-direct mode with ``rfcomm-client'' label.

CAVEAT

The rfcomm_pppd utility in server mode will try to register

Bluetooth LAN
Access Over PPP service with local SPD daemon. If local SDP

daemon is
not running the rfcomm_pppd utility will exit with error.

SEE ALSO

rfcomm_sppd(1), bluetooth(3), ng_btsocket(4), ppp(8), sdp

control(8),
sdpd(8)

AUTHORS

Maksim Yevmenkin <m_evmenkin@yahoo.com>

BSD February 4, 2003

BSD