SNETD.OPTIONS(4)SNETD.OPTIONS(4)NAMEsnetd.options - network configuration file
DESCRIPTION
The snetd.options file describes the configuration of the STREAMS network
constructed by snetd(1M).
The file is in two sections, separated by a line consisting of the
character sequence '%%'. Blank lines may be used freely throughout the
file, and a token (see below) beginning with an unquoted '#' (hash)
denotes a comment which lasts till the end of the line. In addition, a
backslash (\) immediately preceding the end of a line results in the
newline being treated as whitespace (except at the end of comment lines).
Tokens consist either of
a) a single occurrence of the special characters { '=', '{', ',', '}' }
(Note: '=' is not a special character within the brace-enclosed argument
list of a control message; ',' is only a special character in this
position.)
b) strings of arbitrary characters enclosed in single or double quotes
(''' or '"'), but not containing a newline - each quoting character
quotes the other, for example, "foo 'bar'" or '"foo" bar'
(Newlines occurring within quoted strings will silently terminate the
string.)
c) sequences of non-whitespace characters not including any of the
special characters or quotes
All strings are case-sensitive, and are silently truncated to 200
characters.
The modules section describes the individual modules and drivers from
which the STREAMS network configuration will be built.
tcp dc /dev/tcp
arp m arp
x25 dc /dev/x25
lapb0 dc /dev/lapb0
Each line (such as the examples above) consists of three tokens
(separated by whitespace) as follows.
The module identifier is the name by which the module or driver will be
known in the streams section (see below).
The module type is a sequence of character flags describing the module or
driver. The flag 'd' describes a STREAMS driver , whereas 'm' describes
a module. The 'c' flag specifies a driver to be cloneable. (See the
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STREAMS Programmer's Guide for a detailed description of modules and
drivers.)
The module name is the character device name for a driver, or the
pushable module name for a module.
The streams section describes the architecture of the network in terms of
how the previously defined modules and drivers are to be combined (by
means of the appropriate PUSHes and LINKs) into streams. Multiplexing
and cloning are handled automatically by the snetd(1M) utility.
ip arp IP_NET=89.0.0.3
x25 lapb0 SHELL="x25tune -P -s A def.dte.x25" \
X25_SET_SNID={A, LC_LAPBDTE, , }
Lines in this section (such as the above examples) are of the following
form.
The first two tokens on a line are names (module identifiers as defined
in the previous section) of drivers or modules which are to form the
upstream and downstream components respectively of a STREAMS link.
Each link performed between token 1 and token 2 generates a mux_id
(multiplexing identifier) which is associated with that link. It is
possible to override the generated link by replacing token 2 with an
explicit mux_id, for example:
lapb0 1 LL_SET_SNID=A \
SHELL="lltune -P -p lapb -s B -d /dev/lapb0 def.lapb"
This sets the mux_id associated with the link to 1 .
These names may be qualified by a suffix consisting of a colon (:) and a
number (for example arp:1) to signify a particular instantiation of a
module. (An uninstantiated name is an abbreviation for name:0.) Each
instantiation of a module can be thought of as a separate block in a
STREAMS Architecture diagram. Separate instantiations would be
appropriate for, say, a module pushed above more than one driver, but not
for a cloneable multiplexed driver.
Instantiations are used in the 'streams' section only, to instantiate
modules defined in the 'modules' section. The following networking
example would run IP over two distinct networks:
ip dc /dev/ip
arp m arp
ethr0 dc /dev/ethr0
ethr1 dc /dev/ethr1
%%
ip arp:0 IP_NET=89.0.0.1
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arp:0 ethr0 ARP_TYPE
ip arp:1 IP_NET=89.0.0.2
arp:1 ethr1 ARP_TYPE
The remainder of each line consists of a (possibly null) sequence of
control actions to be performed on completion of the link in the order
specified.
Each control action is of the form function = argument-list, where the
argument-list is either a single string argument or a comma-separated
list enclosed in braces ({ and }). Control actions requiring no
arguments may consist simply of the function component. Arguments
containing whitespace or any of the special characters listed above must
be quoted.
A special dummy link exists, where no link is formed, but the control
action is executed. This occurs when token 2 is a hyphen ( '-' ) .
For example:
x25 - SHELL="pvcmap -P"
which is simply a shell call to execute pvcmap .
FILES
/etc/config/snetd.options
SEE ALSOsnetd(1M), hosts(4).
The STREAMS Programmer's Guide .
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