This function initializes the PPP options, pointed to by the
options parameter, to the default state. Once
the defaults have been initialized, application code may adjust them
by assigning new values to the the fields of the
cyg_ppp_options_t structure.
This function returns zero if the options were initialized
successfully. It returns -1 if the options
argument is NULL, or the options could not be initialized.
The option fields, their functions and default values are as follows:
debug
If set to 1 this enables the reporting of debug messages
from the PPP system. These will be generated using
diag_printf() and will appear on the standard
debug channel. Note that diag_printf()
disables interrupts during output: this may cause the PPP link
device to overrun and miss characters. It is quite possible for
this option to cause errors and even make the PPP link fail
completely. Consequently, this option should be used with care.
Default value: 0
kdebugflag
This five bit field enables low level debugging messages from
the PPP device layer in the TCP/IP stack. As with the
debug option, this may result in missed
characters and cause errors. The bits of the field have the
following meanings:
Bit
BSD Name
Description
0x01
SC_DEBUG
Enable debug messages
0x02
SC_LOG_INPKT
Log contents of good packets received
0x04
SC_LOG_OUTPKT
Log contents of packets sent
0x08
SC_LOG_RAWIN
Log all characters received
0x10
SC_LOG_FLUSH
Log all characters flushed
Default value: 0
default_route
If set to 1 this option causes the PPP subsystem to install
a default route in the TCP/IP stack's routing tables using the
peer as the gateway. This entry will be removed when the PPP link
is broken. If there is already an existing working network
connection, such as an ethernet device, then there may already be
a default route established. If this is the case, then this option
will have no effect.
Default value: 1
modem
If this option is set to 1, then the modem lines will be
used during the connection. Specifically, the PPP subsystem will
wait until the carrier detect signal is
asserted before bringing up the PPP link, and will take the PPP
link down if this signal is de-asserted.
Default value: 0
flowctl
This option is used to specify the mechanism used to
control data flow across the serial line. It can take one of the
following values:
CYG_PPP_FLOWCTL_DEFAULT
The flow control mechanism is not changed and is left at
whatever value was set before bringing PPP up. This allows
a non-standard flow control mechanism to be used, or for it to
be chosen and set by some other means.
CYG_PPP_FLOWCTL_NONE
Flow control is turned off. It is not recommended that this
option be used unless the baud rate is set low or the two
communicating machines are particularly fast.
CYG_PPP_FLOWCTL_HARDWARE
Use hardware flow control via the RTS/CTS lines. This is the
most effective flow control mechanism and should always be
used if available. Availability of this mechanism depends on
whether the serial device hardware has the ability to control
these lines, whether they have been connected to the socket
pins and whether the device driver has the necessary support.
CYG_PPP_FLOWCTL_SOFTWARE
Use software flow control by embedding XON/XOFF characters in
the data stream. This is somewhat less effective that hardware
flow control since it is subject to the propagation time of
the serial cable and the latency of the communicating
devices. Since it does not rely on any hardware support, this
flow control mechanism is always available.
Default value: CYG_PPP_FLOWCTL_HARDWARE
refuse_pap
If this option is set to 1, then the PPP subsystem will not
agree to authenticate itself to the peer with PAP. When dialling
in to a remote server it is normal to authenticate the
client. There are three ways this can be done, using a
straightforward login mechanism via the CHAT script, with the
Password Authentication Protocol (PAP), or with the Challenge
Handshake Authentication Protocol (CHAP). For PAP to work the
user and
passwd options must be set to the
expected values. If they are not, then this option should be set
to force CHAP authentication.
Default value: 0
refuse_chap
If this option is set to 1, then the PPP subsystem will not
agree to authenticate itself to the peer with CHAP. CHAP
authentication will only work if the
passwd option has been set to the
required CHAP secret for the destination server. Otherwise this
option should be disabled.
If both refuse_pap and
refuse_chap are set, then either no
authentication will be carried out, or it is the responsibility of
the chat script to do it. If the peer does not
require any authentication, then the setting of these options is
irrelevant.
Default value: 0
baud
This option is set to the baud rate at which the serial
connection should be run. The default value is the rate at which
modems conventionally operate. This field is an instance of the
cyg_serial_baud_rate_t enum defined in the
serialio.h header and may only take one of the
baud rate constants defined in there.
Default value: CYGNUM_SERIAL_BAUD_115200
idle_time_limit
This is the number of seconds that the PPP connection may
be idle before it is shut down automatically.
Default value: 60
maxconnect
This causes the connection to terminate when it has been up
for this number of seconds. The default value of zero means that
the connection will stay up indefinitely, until either end
explicitly brings it down, or the link is lost.
Default value: 0
our_address
This is the IP address, in network byte order, to be
attached to the local end of the PPP connection. The default value
of INADDR_ANY causes the local address to be
obtained from the peer.
Default value: INADDR_ANY
his_address
This is the IP address, in network byte order, to be
attached to the remote end of the PPP connection. The default
value of INADDR_ANY causes the remote address
to be obtained from the peer.
Default value: INADDR_ANY
accept_local
This allows the behaviour described above
for our_address to be modified. Normally,
if our_address is set, then the PPPD will
insist that this address be used. However, if this option is also
set, the PPPD will accept a value supplied by the peer.
Default value: 0
accept_remote
This allows the behaviour described above
for his_address to be modified. Normally,
if his_address is set, then the PPPD will
insist that this address be used. However, if this option is also
set, the PPPD will accept a value supplied by the peer.
Default value: 0
script
This is a pointer to a CHAT script suitable for passing to
cyg_ppp_chat(). See Chapter 128
for details of the format and contents of this script.
Default value: NULL
user
This array contains the user name to be used for PAP
authentication. This field is not used for CHAP authentication. By
default the value of this option is set from the
CYGPKG_PPP_AUTH_DEFAULT_USER configuration
option.
Default value: CYGPKG_PPP_AUTH_DEFAULT_USER
passwd
This array contains the password to be used for PAP
authentication, or the secret to be used during CHAP
authentication. By default the value of this option is set from
the CYGPKG_PPP_AUTH_DEFAULT_PASSWD
configuration option.
