- name change of prefered -> preferred
- CMT fast recover code added.
- Comment fixes in CMT.
- We were not giving a reason of cant_start_asoc per socket api
if we failed to get init/or/cookie to bring up an assoc. Change
so we don't just give a generic "comm lost" but look at actual
states of dying assoc.
- change "crc32" arguments to "crc32c" to silence strict/noisy
compiler warnings when crc32() is also declared
- A few minor tweaks to get the portable stuff truely portable
for sctp6_usrreq.c :-D
- one-2-one style vrf match problem.
- window recovery would leave chks marked for retran
during window probes on the sent queue. This would then
cause an out-of-order problem and assure that the flight
size "problem" would occur.
- Solves a flight size logging issue that caused rwnd
overruns, flight size off as well as false retransmissions.g
- Macroize the up and down of flight size.
- Fix a ECNE bug in its counting.
- The strict_sacks options was causing aborts when window probing
was active, fix to make strict sacks a bit smarter about what
the next unsent TSN is.
- Fixes a one-2-one wakeup bug found by Martin Kulas.
- If-defed out form, Andre's copy routines pending his
commit of at least m_last().. need to adjust for 6.2 as
well.. since m_last won't exist.
Reviewed by: gnn
- fixed a refcount bug in the new ifa structures.
- use vrf's from default stcb or inp whenever possible.
- Address limits raised to account for a full IP fragmented
packet (1000 addresses).
- flight size correcting updated to include one message only
and to handle case where the peer does not cumack the
next segment aka lists 1/1 in sack blocks..
- Various bad init/init-ack handling could cause a panic
since we tried to unlock the destroyed mutex. Fixes
so we properly exit when we need to destroy an assoc.
(Found by Cisco DevTest team :D)
- name rename in src-addr-selection from pass to sifa.
- route structure typedef'd to allow different platforms
and updated into sctp_os_bsd file.
- Max retransmissions a chunk can be made added.
Reviewed by: gnn
obtaining and releasing shared and exclusive locks. The algorithms for
manipulating the lock cookie are very similar to that rwlocks. This patch
also adds support for exclusive locks using the same algorithm as mutexes.
A new sx_init_flags() function has been added so that optional flags can be
specified to alter a given locks behavior. The flags include SX_DUPOK,
SX_NOWITNESS, SX_NOPROFILE, and SX_QUITE which are all identical in nature
to the similar flags for mutexes.
Adaptive spinning on select locks may be enabled by enabling the
ADAPTIVE_SX kernel option. Only locks initialized with the SX_ADAPTIVESPIN
flag via sx_init_flags() will adaptively spin.
The common cases for sx_slock(), sx_sunlock(), sx_xlock(), and sx_xunlock()
are now performed inline in non-debug kernels. As a result, <sys/sx.h> now
requires <sys/lock.h> to be included prior to <sys/sx.h>.
The new kernel option SX_NOINLINE can be used to disable the aforementioned
inlining in non-debug kernels.
The size of struct sx has changed, so the kernel ABI is probably greatly
disturbed.
MFC after: 1 month
Submitted by: attilio
Tested by: kris, pjd
incorrect, non-bundlable fragmentation.
- Added min residual to better control split points for
both how big a msg must be as well as how much needs
to be left over.
- With our new algo in place, we need to implicitly
set "end of msg" on the sp-> structure otherwise we
end up with "hung" associations.
- Room reserved up front in IP header by pushing IP
header to back of mbuf.
- Fix so FR's peg count of retransmissions needed.
- Fix so an unlucky chunk that never gets across
will kill the assoc via the kill timer and send an
abort too.
- Fix bug in sctp_input which can result in a crash.
- Do not strip off IP options anymore.
- Clean up sctp_calculate_rto().
- Get rid of unused sysctl.
- Fixed so we discard all M-Cast
- Fixed so port check done AFTER checksum
- Fixed bug in fragmentation code that prevented
us from fragmenting a small complete message when
we needed to.
- Window probes were not marked back to unsent and
flight adjusted when a sack came in with no
window change or accepting of the probe data.
We now fix this with having a mark on the net and
the chunk so we can clear it out when the sack arrives
forcing it to retran just like it was "new" this
improves the handling of window probes, which were
dropped by the receiver.
- Tighten AUTH protocol error checks during INIT/INIT-ACK exchange
structures. Detect when ifnet instances are detached from the network
stack and perform appropriate cleanup to prevent memory leaks.
This has been implemented in such a way as to be backwards ABI compatible.
Kernel consumers are changed to use if_delmulti_ifma(); in_delmulti()
is unable to detect interface removal by design, as it performs searches
on structures which are removed with the interface.
With this architectural change, the panics FreeBSD users have experienced
with carp and pfsync should be resolved.
Obtained from: p4 branch bms_netdev
Reviewed by: andre
Sponsored by: Garance A Drosehn
Idea from: NetBSD
MFC after: 1 month
- SB_CLEAR macro defined and used for sb clearing.
- Fix for CMT express_sack_handling did not do proper
pseudo-cumack updates.
- Get rid of extraneous function that was never used ip_2_ip6_hdr()
- Fixed source address selection bug (initialization problem).
- Source address selection debug added.
- moved away from ifn/ifa access to sctp_ifa/sctp_ifn
built and managed by the add-ip code.
- cleaned up add-ip code to use the iterator
- made iterator be a thread, which enables auto-asconf now.
- rewrote and cleaned up source address selection (also
made it use new structures).
- Fixed a couple of memory leaks.
- DACK now settable as to how many packets to delay as
well as time.
- connectx() to latest socket API, new associd arg.
- Fixed issue with revoking and loosing potential to
send when we inflate the flight size. We now inflate
the cwnd too and deflate it later when the revoked
chunk is sent or acked.
- Got rid of some temp debug code
- src addr selection moved to a common file (sctp_output.c)
- Support for simple VRF's (we have support for multi-vfr
via compile switch that is scrubbed from BSD but we won't
need multi-vrf until we first get VRF :-D)
- Rest of mib work for address information now done
- Limit number of addresses in INIT/INIT-ACK to
a #def (30).
Reviewed by: gnn
It is built in the same module as IPv4 multicast forwarding, i.e. ip_mroute.ko,
if and only if IPv6 support is enabled for loadable modules.
Export IPv6 forwarding structs to userland netstat(1) via sysctl(9).
- ZONE get now also take a type cast so it does the
cast like mtod does.
- New macro SCTP_LIST_EMPTY, which in bsd is just
LIST_EMPTY
- Removal of const in some of the static hmac functions
(not needed)
- Store length changes to allow for new fields in auth
- Auth code updated to current draft (this should be the
RFC version we think).
- use uint8_t instead of u_char in LOOPBACK address comparison
- Some u_int32_t converted to uint32_t (in crc code)
- A bug was found in the mib counts for ordered/unordered
count, this was fixed (was referencing a freed mbuf).
- SCTP_ASOCLOG_OF_TSNS added (code will probably disappear
after my testing completes. It allows us to keep a
small log on each assoc of the last 40 TSN's in/out and
stream assignment. It is NOT in options and so is only
good for private builds.
- Some CMT changes in prep for Jana fixing his problem
with reneging when CMT is enabled (Concurrent Multipath
Transfer = CMT).
- Some missing mib stats added.
- Correction to number of open assoc's count in mib
- Correction to os_bsd.h to get right sha2 macros
- Add of special AUTH_04 flags so you can compile the code
with the old format (in case the peer does not yet support
the latest auth code).
- Nonce sum was incorrectly being set in when ecn_nonce was
NOT on.
- LOR in listen with implicit bind found and fixed.
- Moved away from using mbuf's for socket options to using
just data pointers. The mbufs were used to harmonize
NetBSD code since both Net and Open used this method. We
have decided to move away from that and more conform to
FreeBSD style (which makes more sense).
- Very very nasty bug found in some of my "debug" code. The
cookie_how collision case tracking had an endless loop in
it if you got a second retransmission of a cookie collision
case. This would lock up a CPU .. ugly..
- auth function goes to using size_t instead of int which
conforms to socketapi better
- Found the nasty bug that happens after 9 days of testing.. you
get the data chunk, deliver it and due to the reference to a ch->
that every now and then has been deleted (depending on the postion
in the mbuf) you have an invalid ch->ch.flags.. and thus you don't
advance the stream sequence number.. so you block the stream
permanently. The fix is to make local variables of these guys
and set them up before you have any chance of trimming the
mbuf.
- style fix in sctp_util.h, not sure how this got bad maybe in
the last patch? (aka it may not be in the real source).
- Found interesting bug when using the extended snd/rcv info where
we would get an error on receiving with this. Thats because
it was NOT padded to the same size as the snd_rcv info. We
increase (add the pad) so the two structs are the same size
in sctp_uio.h
- In sctp_usrreq.c one of the most common things we did for
socket options was to cast the pointer and validate the size.
This as been macro-ized to help make the code more readable.
- in sctputil.c two things, the socketapi class found a missing
flag type (the next msg is a notification) and a missing
scope recovery was also fixed.
Reviewed by: gnn
IPv6 over point-to-point gif(4) tunnels.
These revisions caused a host route to the destination of a
point-to-point gif(4) interface to not get installed when the interface
and destination addresses were assigned. This caused
"no route to host" errors when trying to send traffic over the
interface. The first packet arriving inbound over the tunnel,
however, would cause the correct route to get installed, allowing
subsequent outbound traffic to be routed correctly.
gif(4) interfaces with prefix lengths of less than 128 bits
(i.e. no explicit destination address assigned) were not affected
by this bug.
This bug fix is a possible candidate for a 6.2-RELEASE errata note.
Approved by: jhay (original committer)
Discussed with: jhay, JINMEI Tatuya
MFC after: 3 days
- Finally all splxx() are removed
- Count error fixed in mapping array which might
cause a wrong cumack generation.
- Invariants around panic for case D + printf when no invariants.
- one-to-one model race condition fixed by using
a pre-formed connection and then completing the
work so accept won't happen on a non-formed
association.
- Some additional paranoia checks in sctp_output.
- Locks that were missing in the accept code.
Approved by: gnn
- Added a short time wait (not used yet) constant
- Corrected the type of the crc32c table (it was
unsigned long and really is a uint32_t
- Got rid of the user of MHeaders until they
are truely needed by lower layers.
- Fixed an initialization problem in the readq structure
(ordering was off).
- Found yet another collision bug when the random number
generator returns two numbers on one side (during a collision)
that are the same. Also added some tracking of cookies
that will go away when we know that we have the last collision
bug gone.
- Fixed an init bug for book_size_scale, that was causing
Early FR code to run when it should not.
- Fixed a flight size tracking bug that was associated with
Early FR but due to above bug also effected all FR's
- Fixed it so Max Burst also will apply to Fast Retransmit.
- Fixed a bug in the temporary logging code that allowed a
static log array overflow
- hashinit_flags is now used.
- Two last mcopym's were converted to the macro sctp_m_copym that
has always been used by all other places
- macro sctp_m_copym was converted to upper case.
- We now validate sinfo_flags on input (we did not before).
- Fixed a bug that prevented a user from sending data and immediately
shuting down with one send operation.
- Moved to use hashdestroy instead of free() in our macros.
- Fixed an init problem in our timed_wait vtag where we
did not fully initialize our time-wait blocks.
- Timer stops were re-positioned.
- A pcb cleanup method was added, however this probably will
not be used in BSD.. unless we make module loadable protocols
- I think this fixes the mysterious timer bug.. it was a
ordering of locks problem in the way we did timers. It
now conforms to the timeout(9) manual (except for the
_drain part, we had to do this a different way due
to locks).
- Fixed error return code so we get either CONNREUSED or CONNRESET
depending on where one is in progression
- Purged an unused clone macro.
- Fixed a read erro code issue where we were NOT getting the proper
error when the connection was reset.
- Purged an unused clone macro.
- Fixed a read erro code issue where we were NOT getting the proper
error when the connection was reset.
Approved by: gnn
access plus timers. This makes the code
more portable and able to change out the
mbuf or timer system used more easily ;-)
b) removal of all use of pkt-hdr's until only
the places we need them (before ip_output routines).
c) remove a bunch of code not needed due to <b> aka
worrying about pkthdr's :-)
d) There was one last reorder problem it looks where
if a restart occur's and we release and relock (at
the point where we setup our alias vtag) we would
end up possibly getting the wrong TSN in place. The
code that fixed the TSN's just needed to be shifted
around BEFORE the release of the lock.. also code that
set the state (since this also could contribute).
Approved by: gnn
2) Fix all "magic numbers" to be constants.
3) A collision case that would generate two associations to
the same peer due to a missing lock is fixed.
4) Added tracking of where timers are stopped.
Approved by: gnn
In ip6_sprintf no longer use and return one of eight static buffers
for printing/logging ipv6 addresses.
The caller now has to hand in a sufficiently large buffer as first
argument.
to add a reference to it; otherwise, we could later access
a freed memory. This is believed to fix panics some users
were observing when running route6d(8), and is similar to
the fix in sys/netinet/if_ether.c,v 1.139 by glebius@.
PR: kern/93910, kern/105437
Testing by: Wojciech Puchar (still ongoing)
- Add rtentry locking to nd6_output() similar to rt_check().
MFC after: 4 days
copy's were incorrect and so was the locking.
-A bug was also found that would create a race and
panic when an abort arrived on a socket being read
from.
-Also fix the reader to get MSG_TRUNC when a partial
delivery is aborted.
-Also addresses a couple of coverity caught error path
memory leaks and a couple of other valid complaints
Approved by: gnn
patch was prepared and committed to priv(9) calls. Add XXX comments
as, in each case, the semantics appear to differ from the TCP/UDP
versions of the calls with respect to jail, and because cr_canseecred()
is not used to validate the query.
Obtained from: TrustedBSD Project
specific privilege names to a broad range of privileges. These may
require some future tweaking.
Sponsored by: nCircle Network Security, Inc.
Obtained from: TrustedBSD Project
Discussed on: arch@
Reviewed (at least in part) by: mlaier, jmg, pjd, bde, ceri,
Alex Lyashkov <umka at sevcity dot net>,
Skip Ford <skip dot ford at verizon dot net>,
Antoine Brodin <antoine dot brodin at laposte dot net>
This also moves two 16 bit int's to become 32 bit
values so we do not have to use atomic_add_16.
Most of the changes are %p, casts and other various
nasty's that were in the orignal code base. With this
commit my machine will now do a build universe.. however
I as yet have not tested on a 64bit machine .. it may not work :-(
inserted a few to the new files.. but I falied to
add the #include <sys/cdef.h>
Which causes a compile error.. sorry about that... got it
now :-)
Approved by:gnn
work is not just mine, but it is also the works of Peter Lei
and Michael Tuexen. They both are my two key other developers
working on the project.. and they need ata-boy's too:
****
peterlei@cisco.comtuexen@fh-muenster.de
****
I did do a make sysent which updated the
syscall's and sysproto.. I hope that is correct... without
it you don't build since we have new syscalls for SCTP :-0
So go out and look at the NOTES, add
option SCTP (make sure inet and inet6 are present too)
and play with SCTP.
I will see about comitting some test tools I have after I
figure out where I should place them. I also have a
lib (libsctp.a) that adds some of the missing socketapi
functions that I need to put into lib's.. I will talk
to George about this :-)
There may still be some 64 bit issues in here, none of
us have a 64 bit processor to test with yet.. Michael
may have a MAC but thats another beast too..
If you have a mac and want to use SCTP contact Michael
he maintains a web site with a loadable module with
this code :-)
Reviewed by: gnn
Approved by: gnn
begun with a repo-copy of mac.h to mac_framework.h. sys/mac.h now
contains the userspace and user<->kernel API and definitions, with all
in-kernel interfaces moved to mac_framework.h, which is now included
across most of the kernel instead.
This change is the first step in a larger cleanup and sweep of MAC
Framework interfaces in the kernel, and will not be MFC'd.
Obtained from: TrustedBSD Project
Sponsored by: SPARTA
Use something like this:
route add -inet6 <dest_addr> <my_addr_on_that_interface> -interface -llinfo
This is usefull for wireless adhoc mesh networks.
MFC after: 5 days
o add IFCAP_TSO[46] for drivers to announce this capability for IPv4 and IPv6
o add CSUM_TSO flag to mbuf pkthdr csum_flags field
o add tso_segsz field to mbuf pkthdr
o enhance ip_output() packet length check to allow for large TSO packets
o extend tcp_maxmtu[46]() with a flag pointer to pass interface capabilities
o adjust all callers of tcp_maxmtu[46]() accordingly
Discussed on: -current, -net
Sponsored by: TCP/IP Optimization Fundraise 2005
were unused or already in if_var.h so add if_name() to if_var.h and
remove net_osdep.h along with all references to it.
Longer term we may want to kill off if_name() entierly since all modern
BSDs have if_xname variables rendering it unnecessicary.
Remove the README file which warns against cosmetic or local only
changes. FreeBSD committers should now feel free to work on the
IPv6 and IPSec code without fetters. The KAME mailing lists still
exist and it is always a good idea to ask questions about this code
on the snap-users@kame.net mailing list.
Reviewed by: rwatson, brooks
function, pru_close, to notify protocols that the file descriptor or
other consumer of a socket is closing the socket. pru_abort is now a
notification of close also, and no longer detaches. pru_detach is no
longer used to notify of close, and will be called during socket
tear-down by sofree() when all references to a socket evaporate after
an earlier call to abort or close the socket. This means detach is now
an unconditional teardown of a socket, whereas previously sockets could
persist after detach of the protocol retained a reference.
This faciliates sharing mutexes between layers of the network stack as
the mutex is required during the checking and removal of references at
the head of sofree(). With this change, pru_detach can now assume that
the mutex will no longer be required by the socket layer after
completion, whereas before this was not necessarily true.
Reviewed by: gnn
( and where appropriate the destruction) of the pcb mutex to the init/finit
functions of the pcb zones.
This allows locking of the pcb entries and race condition free comparison
of the generation count.
Rearrange locking a bit to avoid extra locking operation to update the generation
count in in_pcballoc(). (in_pcballoc now returns the pcb locked)
I am planning to convert pcb list handling from a type safe to a reference count
model soon. ( As this allows really freeing the PCBs)
Reviewed by: rwatson@, mohans@
MFC after: 1 week
the mbuf chain. If we ever get a buggy caller, a bogus "off" should
be caught by the sanity check at the function entry. Null "m" here
means a very unusual condition of a totally broken mbuf chain (wrong
m_pkthdr.len or whatever), so we can just page fault later.
Found by: Coverity Prevent(tm)
CID: 825
except in places dealing with ifaddr creation or destruction; and
in such special places incomplete ifaddrs should never be linked
to system-wide data structures. Therefore we can eliminate all the
superfluous checks for "ifa->ifa_addr != NULL" and get ready
to the system crashing honestly instead of masking possible bugs.
Suggested by: glebius, jhb, ru
functions not yet asserting it but working on global ip6_forward_rt
route cache which is not locked and perhaps should go away in the
future though cache hit/miss ration wasn't bad.
It's #if 0ed in frag6 because the code working on ip6_forward_rt is.
into its own function, udp6_append(). This mirrors a similar structure
in udp_input() and udp_append(), and makes the whole thing a lot more
readable.
While here, add missing inpcb locking in UDP6 input path.
Reviewed by: bz
MFC after: 3 months
even if we're going to return an argument-based error.
Assert pcbinfo lock in in6_pcblookup_local(), in6_pcblookup_hash(), since
they walk pcbinfo inpcb lists.
Assert inpcb and pcbinfo locks in in6_pcbsetport(), since
port reservations are changing.
MFC after: 3 months
list head structure; this improves congruence to IPv4, and also allows
in6_pcbpurgeif0() to lock the pcbinfo. Modify in6_pcbpurgeif0() to lock
the pcbinfo before iterating the pcb list, use queue(9)'s LIST_FOREACH()
for the iteration, and to lock individual inpcb's while manipulating
them.
MFC after: 3 months
UDPv6 delivery.
Lock the inpcb of the UDP connection being delivered to before
processing IPSEC policy and other delivery activities.
MFC after: 3 months
pru_abort(), pru_detach(), and in_pcbdetach():
- Universally support and enforce the invariant that so_pcb is
never NULL, converting dozens of unnecessary NULL checks into
assertions, and eliminating dozens of unnecessary error handling
cases in protocol code.
- In some cases, eliminate unnecessary pcbinfo locking, as it is no
longer required to ensure so_pcb != NULL. For example, in protocol
shutdown methods, and in raw IP send.
- Abort and detach protocol switch methods no longer return failures,
nor attempt to free sockets, as the socket layer does this.
- Invoke in_pcbfree() after in_pcbdetach() in order to free the
detached in_pcb structure for a socket.
MFC after: 3 months
- in_pcbdetach(), which removes the link between an inpcb and its
socket.
- in_pcbfree(), which frees a detached pcb.
Unlike the previous in_pcbdetach(), neither of these functions will
attempt to conditionally free the socket, as they are responsible only
for managing in_pcb memory. Mirror these changes into in6_pcbdetach()
by breaking it into in6_pcbdetach() and in6_pcbfree().
While here, eliminate undesired checks for NULL inpcb pointers in
sockets, as we will now have as an invariant that sockets will always
have valid so_pcb pointers.
MFC after: 3 months
rather than an error. Detaches do not "fail", they other occur or
the protocol flags SS_PROTOREF to take ownership of the socket.
soclose() no longer looks at so_pcb to see if it's NULL, relying
entirely on the protocol to decide whether it's time to free the
socket or not using SS_PROTOREF. so_pcb is now entirely owned and
managed by the protocol code. Likewise, no longer test so_pcb in
other socket functions, such as soreceive(), which have no business
digging into protocol internals.
Protocol detach routines no longer try to free the socket on detach,
this is performed in the socket code if the protocol permits it.
In rts_detach(), no longer test for rp != NULL in detach, and
likewise in other protocols that don't permit a NULL so_pcb, reduce
the incidence of testing for it during detach.
netinet and netinet6 are not fully updated to this change, which
will be in an upcoming commit. In their current state they may leak
memory or panic.
MFC after: 3 months
than an int, as an error here is not meaningful. Modify soabort() to
unconditionally free the socket on the return of pru_abort(), and
modify most protocols to no longer conditionally free the socket,
since the caller will do this.
This commit likely leaves parts of netinet and netinet6 in a situation
where they may panic or leak memory, as they have not are not fully
updated by this commit. This will be corrected shortly in followup
commits to these components.
MFC after: 3 months
probably never fully applied to IPv6. Over time it has become more
stale, so replace it with something more up to date.
Reviewed by: ume
MFC after: 1 month
ipsec_copypkt(), as this is already handled by the call to M_MOVE_PKTHDR(),
which also knows how to correctly handle MAC m_tags. This corrects a panic
when running with MAC and KAME IPSEC.
PR: kern/94599
Submitted by: zhouyi zhou <zhouyi04 at ios dot cn>
Reviewed by: bz
MFC after: 3 days
net.inet.ip.portrange.reservedlow apply to IPv6 aswell as IPv4.
We could have made new sysctls for IPv6, but that potentially makes
things complicated for mapped addresses. This seems like the least
confusing option and least likely to cause obscure problems in the
future.
This change makes the mac_portacl module useful with IPv6 apps.
Reviewed by: ume
MFC after: 1 month
filtering mechanisms to use the new rwlock(9) locking API:
- Drop the variables stored in the phil_head structure which were specific to
conditions and the home rolled read/write locking mechanism.
- Drop some includes which were used for condition variables
- Drop the inline functions, and convert them to macros. Also, move these
macros into pfil.h
- Move pfil list locking macros intp phil.h as well
- Rename ph_busy_count to ph_nhooks. This variable will represent the number
of IN/OUT hooks registered with the pfil head structure
- Define PFIL_HOOKED macro which evaluates to true if there are any
hooks to be ran by pfil_run_hooks
- In the IP/IP6 stacks, change the ph_busy_count comparison to use the new
PFIL_HOOKED macro.
- Drop optimization in pfil_run_hooks which checks to see if there are any
hooks to be ran, and returns if not. This check is already performed by the
IP stacks when they call:
if (!PFIL_HOOKED(ph))
goto skip_hooks;
- Drop in assertion which makes sure that the number of hooks never drops
below 0 for good measure. This in theory should never happen, and if it
does than there are problems somewhere
- Drop special logic around PFIL_WAITOK because rw_wlock(9) does not sleep
- Drop variables which support home rolled read/write locking mechanism from
the IPFW firewall chain structure.
- Swap out the read/write firewall chain lock internal to use the rwlock(9)
API instead of our home rolled version
- Convert the inlined functions to macros
Reviewed by: mlaier, andre, glebius
Thanks to: jhb for the new locking API
however IPv4-in-IPv4 tunnels are now stable on SMP. Details:
- Add per-softc mutex.
- Hold the mutex on output.
The main problem was the rtentry, placed in softc. It could be
freed by ip_output(). Meanwhile, another thread being in
in_gif_output() can read and write this rtentry.
Reported by: many
Tested by: Alexander Shiryaev <aixp mail.ru>
