ETHER(3)ETHER(3)NAMEether - Ethernet device
SYNOPSIS
bind -a #ln /net
/net/ethern/clone
/net/ethern/[0-7]
/net/ethern/[0-7]/data
/net/ethern/[0-7]/ctl
/net/ethern/[0-7]/stats
/net/ethern/[0-7]/type
/net/ethern/[0-7]/ifstats
DESCRIPTION
The Ethernet device #ln serves a three-level directory representing a
physical Ethernet interface: AMD LANCE, 3Com 3C509, 3Com 3C905, Intel
82557, and others. If n is not given it is taken to be 0.
The top level directory has a single directory named ethern, where n is
the interface number, starting from 0, assigned in some platform-depen‐
dent way. That directory contains a conversation directory for each of
8 Ethernet packet types, and a clone file.
Opening the clone file returns a file descriptor open on the ctl file
of an unused conversation directory. Reading the ctl file returns a
text string representing the number of the connection. The connection
is controlled by writing textual commands to the associated ctl file:
connect type
Set the type of Ethernet packets received on the connection; the
type is expressed as an integer constant (in hexadecimal if it
has a leading 0x, octal if it has a leading 0, and otherwise
decimal). For instance, Ethernet packets carrying IP version 4
use type 0x800. The value -1 stands for all types. The value
-2 causes at most the first 64 bytes of all types of packets to
be copied to the conversation. If several conversations are
assigned the same packet type, a copy of the packet is given to
each.
promiscuous
Set the interface to capture all packets regardless of destina‐
tion address. An interface normally receives only packets whose
destination address is that of the interface or is the broadcast
address, ffffffffffff. The interface remains promiscuous until
the control file is closed. The extra packets are received only
by conversations of the same type as the incoming packet (or of
type -1).
addmulti address
Add the given MAC multicast address to the set of multicast
addresses accepted by the interface. Address is a twelve digit
MAC address in hexadecimal.
remmulti address
Remove address from the set of multicast addresses accepted by
the interface.
Incoming Ethernet packets are demultiplexed by destination address and
packet type and queued for reading by the corresponding open connec‐
tion(s). Each read of the data file returns each packet in turn,
including the Ethernet header. A read will terminate at packet bound‐
aries. Each write to the data file causes a packet to be sent. The
Ethernet address of the interface is inserted into the packet header as
the source address.
Reading the type file returns the decimal value of the assigned Ether‐
net packet type.
Reading the stats file returns status information, the value of coun‐
ters, the `promiscuous' state, and the Ethernet MAC address of the
interface.
Reading the ifstats file returns statistics and status information spe‐
cific to a given hardware interface.
SOURCE
/os/port/devlance.c
/os/port/netif.c
/os/*/devether.c
/os/*/ether*.c
SEE ALSOip(3)ETHER(3)
