Setting this flag on an ethernet interface blocks transmission of packets
and discards incoming packets after BPF processing.
This is useful if you want to monitor network trafic but not interact
with the network in question.
Sponsored by: http://www.babeltech.dk
I should have committed this ages ago.
The MFC for if_ethersubr.c could be done in the usual few days (only
ipfw2 uses it), the one for bridge.c should probably wait until
after 4.7 because it changes an existing though mostly undocumented
behaviour (on which i hope nobody relies). All in all, i'll wait for
both things unless there is demand.
MFC after: 35 days
Also, for all interfaces in this mode pass all ethernet frames to upper layer,
even those not addressed to our own MAC, which allows packets encapsulated
in those frames be processed with packet filters (ipfw(8) et al).
Emphatically requested by: Anton Turygin <pa3op@ukr-link.net>
Valuable suggestions by: fenner
the mbuf contains the ethernet header (eh) as well, which ether_input()
will strip off as needed.
This permits the removal (in a backward compatible way) of the
header removal code which right now is replicated in all drivers,
sometimes in an inconsistent way. Also, because many functions
called after ether_input() require the eh in the mbuf, eventually
we can propagate the interface and handle outdated drivers just
in ether_input().
Individual driver changes to use the new interface will follow as
we have a chance to touch them.
NOTE THAT THIS CHANGE IS FULLY BACKWARD COMPATIBLE AND DOES NOT BREAK
BINARY COMPATIBILITY FOR DRIVERS.
MFC after: 3 days
kernel access control.
Label mbufs received via ethernet-based interfaces by invoking
appropriate MAC framework entry points.
Perform access control checks on out-going mbufs delivered via
ethernet-based interfaces by invoking appropriate MAC entry
points.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, NAI Labs
packet forwarding state ("annotations") during ip processing.
The code is considerably cleaner now.
The variables removed by this change are:
ip_divert_cookie used by divert sockets
ip_fw_fwd_addr used for transparent ip redirection
last_pkt used by dynamic pipes in dummynet
Removal of the first two has been done by carrying the annotations
into volatile structs prepended to the mbuf chains, and adding
appropriate code to add/remove annotations in the routines which
make use of them, i.e. ip_input(), ip_output(), tcp_input(),
bdg_forward(), ether_demux(), ether_output_frame(), div_output().
On passing, remove a bug in divert handling of fragmented packet.
Now it is the fragment at offset 0 which sets the divert status of
the whole packet, whereas formerly it was the last incoming fragment
to decide.
Removal of last_pkt required a change in the interface of ip_fw_chk()
and dummynet_io(). On passing, use the same mechanism for dummynet
annotations and for divert/forward annotations.
option IPFIREWALL_FORWARD is effectively useless, the code to
implement it is very small and is now in by default to avoid the
obfuscation of conditionally compiled code.
NOTES:
* there is at least one global variable left, sro_fwd, in ip_output().
I am not sure if/how this can be removed.
* I have deliberately avoided gratuitous style changes in this commit
to avoid cluttering the diffs. Minor stule cleanup will likely be
necessary
* this commit only focused on the IP layer. I am sure there is a
number of global variables used in the TCP and maybe UDP stack.
* despite the number of files touched, there are absolutely no API's
or data structures changed by this commit (except the interfaces of
ip_fw_chk() and dummynet_io(), which are internal anyways), so
an MFC is quite safe and unintrusive (and desirable, given the
improved readability of the code).
MFC after: 10 days
Ipfw processing of frames at layer 2 can be enabled by the sysctl variable
net.link.ether.ipfw=1
Consider this feature experimental, because right now, the firewall
is invoked in the places indicated below, and controlled by the
sysctl variables listed on the right. As a consequence, a packet
can be filtered from 1 to 4 times depending on the path it follows,
which might make a ruleset a bit hard to follow.
I will add an ipfw option to tell if we want a given rule to apply
to ether_demux() and ether_output_frame(), but we have run out of
flags in the struct ip_fw so i need to think a bit on how to implement
this.
to upper layers
| |
+----------->-----------+
^ V
[ip_input] [ip_output] net.inet.ip.fw.enable=1
| |
^ V
[ether_demux] [ether_output_frame] net.link.ether.ipfw=1
| |
+->- [bdg_forward]-->---+ net.link.ether.bridge_ipfw=1
^ V
| |
to devices
not removing tabs before "__P((", and not outdenting continuation lines
to preserve non-KNF lining up of code with parentheses. Switch to KNF
formatting and/or rewrap the whole prototype in some cases.
are checked on the way in even if they were not calculated on the
way out.
This fixes rwhod
PR: 31954
Submitted by: fenner
Approved by: fenner
MFC after: 1 week
- Allocate zeroed memory in ether_resolvemulti() to prevent equal() from
comparing garbage and determining that two otherwise-equal sockaddr_dls
are different.
- Fill in all required fields of the sockaddr_dl
- Actually copy the multicast address into the sockaddr_dl when calling
if_addmulti()
- Don't claim that we don't have a way to resolve layer 3 addresses into
layer 2 addresses; use the ethernet way.
different hardware address, we should drop it (this should only
happen in promiscuous mode). Relocate the code for this check
from before ng_ether(4) processing to after ng_ether(4) processing.
Also fix a compiler warning.
PR: kern/24465
This is because calls with M_WAIT (now M_TRYWAIT) may not wait
forever when nothing is available for allocation, and may end up
returning NULL. Hopefully we now communicate more of the right thing
to developers and make it very clear that it's necessary to check whether
calls with M_(TRY)WAIT also resulted in a failed allocation.
M_TRYWAIT basically means "try harder, block if necessary, but don't
necessarily wait forever." The time spent blocking is tunable with
the kern.ipc.mbuf_wait sysctl.
M_WAIT is now deprecated but still defined for the next little while.
* Fix a typo in a comment in mbuf.h
* Fix some code that was actually passing the mbuf subsystem's M_WAIT to
malloc(). Made it pass M_WAITOK instead. If we were ever to redefine the
value of the M_WAIT flag, this could have became a big problem.
before adding/removing packets from the queue. Also, the if_obytes and
if_omcasts fields should only be manipulated under protection of the mutex.
IF_ENQUEUE, IF_PREPEND, and IF_DEQUEUE perform all necessary locking on
the queue. An IF_LOCK macro is provided, as well as the old (mutex-less)
versions of the macros in the form _IF_ENQUEUE, _IF_QFULL, for code which
needs them, but their use is discouraged.
Two new macros are introduced: IF_DRAIN() to drain a queue, and IF_HANDOFF,
which takes care of locking/enqueue, and also statistics updating/start
if necessary.
pointer, when bridging and bridge_ipfw are enabled, and when bdg_forward()
happens to free the packet and make our pointer NULL. There may be
more similar problems like this one with calls to bdg_forward().
PR: Related to kern/19551
Reviewed by: jlemon
ether_ifdetach().
The former consolidates the operations of if_attach(), ng_ether_attach(),
and bpfattach(). The latter consolidates the corresponding detach operations.
Reviewed by: julian, freebsd-net
