NAME
tap - virtual Ethernet device
SYNOPSIS
pseudo-device tap
DESCRIPTION
The tap driver allows the creation and use of virtual Ethernet devices.
Those interfaces appear just as any real Ethernet NIC to the kernel, but
can also be accessed by userland through a character device node in order
to read frames being sent by the system or to inject frames.
In that respect it is very similar to what tun(4) provides, but the added
Ethernet layer allows easy integration with machine emulators or virtual
Ethernet networks through the use of bridge(4) with tunneling.
``Qui tacet consentire videtur.''
rather than being removed. Also fixed a small comment about the scope of
#if's.
This code is a but ugly IMHO but as long as we dont have to change it ....
explicitly only for the protocols indicated by the #if
Allthough its unlikely a kernel will be build without NET_INET, it will
fail compilation here when NET_INET is not defined.
malloc_type M_IFADDR and freed with malloc_type M_DEVBUF. This
causes a panic(9) in DIAGNOSTIC kernels. Add malloc_type M_IFMEDIA
and use it for both malloc'ing and free'ing ifmedia_entrys.
When the ethernet interface of a pppoe pseudo-interface detaches, remove
the association and mark the pppoe interface down.
This should fix PR kern/28375.
<net/if_dl.h> defines struct sockaddr_dl. On the line defining member
"sdl_family" (which overlaps "sa_family" in struct sockaddr), the
comment says AF_DLI.
But,
1) AF_DLI is said to be a DEC Direct data link interface
(sys/socket.h)
2) The kernel actually sends sockaddr_dl structs with AF_LINK.
Quiting Tom: The problem is the special case of an RTM_GET message
that wants interface information included in the response, and
therefore include the RTA_IFA or RTA_IFP (or both) flags in the
bitmask that says what addresses are supplied in the message. For
the RTM_GET message, it doesn't make sense to supply addresses
other than the one you're asking about, so those two other bits
are, in that specific case, overloaded with this meaning.
There is code in sys/net/rtsock.c to handle the case, but at some
time, extra sanity checking of the received message was added, that
failed to take this possibility into account.
The patch, is needed for the Asterisk software PBX to work properly
when it has multiple interfaces active: it needs to ask the kernel
for the IP address of the interface that will be used to communicate
with a given host.
1.) There is objection against this change by at least one developer.
2.) These changes cause repeatable system lockups and crashes for
at least four people.
received packets in csum_flags in the packet header. Packets that are
forwarded over the bridge need to have csum_flags cleared before being
put on the output queue. Do so in bridge_enqueue().
Discussed with Jason Thorpe.
Fixes PR kern/27007 and the first part of PR kern/21831.
