Alice is too lazy to write a server application in PF-independent
manner. Therefore she knocks up the server using PF_INET6 only
and allows the IPv6 socket to accept mapped IPv4 as well. An evil
hacker known on IRC as cheshire_cat has an account in the same
system. He starts a process listening on the same port as used
by Alice's server, but in PF_INET. As a consequence, cheshire_cat
will distract all IPv4 traffic supposed to go to Alice's server.
Such sort of port theft was initially enabled by copying the code that
implemented the RFC 2553 semantics on IPv4/6 sockets (see inet6(4)) for
the implied case of the same owner for both connections. After this
change, the above scenario will be impossible. In the same setting,
the user who attempts to start his server last will get EADDRINUSE.
Of course, using IPv4 mapped to IPv6 leads to security complications
in the first place, but there is no reason to make it even more unsafe.
This change doesn't apply to KAME since it affects a FreeBSD-specific
part of the code. It doesn't modify the out-of-box behaviour of the
TCP/IP stack either as long as mapping IPv4 to IPv6 is off by default.
MFC after: 1 month
synchronizing IPv6 protocol control blocks and lists. These changes
are modeled on the inpcb locking for IPv4, submitted by Jennifer Yang,
and committed by Jeffrey Hsu. With these locking changes, IPv6 use of
inpcbs is now substantially more MPSAFE, and permits IPv4 inpcb locking
assertions to be run in the presence of IPv6 compiled into the kernel.
(i.e. with the foreign address being not wildcard) when checking
for possible port theft since such connections cannot be stolen.
The port theft check is FreeBSD-specific and isn't in the KAME tree.
PR: bin/65928 (in the audit trail)
Reviewed by: -net, -hackers (silence)
Tested by: Nick Leuta <skynick at mail.sc.ru>
MFC after: 1 month
somewhat clearer, but more importantly allows for a consistent naming
scheme for suser_cred flags.
The old name is still defined, but will be removed in a few days (unless I
hear any complaints...)
Discussed with: rwatson, scottl
Requested by: jhb
for unknown events.
A number of modules return EINVAL in this instance, and I have left
those alone for now and instead taught MOD_QUIESCE to accept this
as "didn't do anything".
your (network) modules as well as any userland that might make sense of
sizeof(struct ifnet).
This does not change the queueing yet. These changes will follow in a
seperate commit. Same with the driver changes, which need case by case
evaluation.
__FreeBSD_version bump will follow.
Tested-by: (i386)LINT
before calling sotryfree().
-- Body of earlier bulk commit this belonged with --
Log:
Extend coverage of SOCK_LOCK(so) to include so_count, the socket
reference count:
- Assert SOCK_LOCK(so) macros that directly manipulate so_count:
soref(), sorele().
- Assert SOCK_LOCK(so) in macros/functions that rely on the state of
so_count: sofree(), sotryfree().
- Acquire SOCK_LOCK(so) before calling these functions or macros in
various contexts in the stack, both at the socket and protocol
layers.
- In some cases, perform soisdisconnected() before sotryfree(), as
this could result in frobbing of a non-present socket if
sotryfree() actually frees the socket.
- Note that sofree()/sotryfree() will release the socket lock even if
they don't free the socket.
Submitted by: sam
Sponsored by: FreeBSD Foundation
Obtained from: BSD/OS
Wind River. In the IPv4 output path, one of the tests in ip_output()
checks how many slots are actually available in the interface output
queue before attempting to send a packet. If, for example, we need
to transmit a packet of 32K bytes over an interface with an MTU of
1500, we know it's going to take about 21 fragments to do it. If
there's less than 21 slots left in the output queue, there's no point
in transmitting anything at all: IP does not do retransmission, so
sending only some of the fragments would just be a waste of bandwidth.
(In an extreme case, if you're sending a heavy stream of fragmented
packets, you might find yourself sending nothing by the first fragment
of all your packets.) So if ip_output() notices there's not enough
room in the output queue to send the frame, it just dumps the packet
and returns ENOBUFS to the app.
It turns out ip6_output() lacks this code. Consequently, this caused
the netperf UDPIPV6_STREAM test to produce very poor results with large
write sizes. This commit adds code to check the remaining space in the
output queue and junk fragmented packets if they're too big to be
sent, just like with IPv4. (I can't imagine anyone's running an NFS
server using UDP over IPv6, but if they are, this will likely make them
a lot happier. :)
1. rt_check() cleanup:
rt_check() is only necessary for some address families to gain access
to the corresponding arp entry, so call it only in/near the *resolve()
routines where it is actually used -- at the moment this is
arpresolve(), nd6_storelladdr() (the call is embedded here),
and atmresolve() (the call is just before atmresolve to reduce
the number of changes).
This change will make it a lot easier to decouple the arp table
from the routing table.
There is an extra call to rt_check() in if_iso88025subr.c to
determine the routing info length. I have left it alone for
the time being.
The interface of arpresolve() and nd6_storelladdr() now changes slightly:
+ the 'rtentry' parameter (really a hint from the upper level layer)
is now passed unchanged from *_output(), so it becomes the route
to the final destination and not to the gateway.
+ the routines will return 0 if resolution is possible, non-zero
otherwise.
+ arpresolve() returns EWOULDBLOCK in case the mbuf is being held
waiting for an arp reply -- in this case the error code is masked
in the caller so the upper layer protocol will not see a failure.
2. arpcom untangling
Where possible, use 'struct ifnet' instead of 'struct arpcom' variables,
and use the IFP2AC macro to access arpcom fields.
This mostly affects the netatalk code.
=== Detailed changes: ===
net/if_arcsubr.c
rt_check() cleanup, remove a useless variable
net/if_atmsubr.c
rt_check() cleanup
net/if_ethersubr.c
rt_check() cleanup, arpcom untangling
net/if_fddisubr.c
rt_check() cleanup, arpcom untangling
net/if_iso88025subr.c
rt_check() cleanup
netatalk/aarp.c
arpcom untangling, remove a block of duplicated code
netatalk/at_extern.h
arpcom untangling
netinet/if_ether.c
rt_check() cleanup (change arpresolve)
netinet6/nd6.c
rt_check() cleanup (change nd6_storelladdr)
a static const global variable in ah_core.c. This makes it more clear
that this array does not require synchronization, as well as
synchronizing the layout to the ESP algorithm list. This is the
version of my patch that Itojun committed to the KAME tree.
Obtained from: me, via KAME
This enables pf to track dynamic address changes on interfaces (dailup) with
the "on (<ifname>)"-syntax. This also brings hooks in anticipation of
tracking cloned interfaces, which will be in future versions of pf.
Approved by: bms(mentor)
pf/pflog/pfsync as modules. Do not list them in NOTES or modules/Makefile
(i.e. do not connect it to any (automatic) builds - yet).
Approved by: bms(mentor)
address, even if we subsequently ignore its value by applying a >>8
to it.
Reported by: "Ted Unangst" <tedu@coverity.com>
Approved by: rwatson (mentor), {ume, suz} (KAME)
mode is applied, since tunneled packets are considered to be
generated packets from a tunnel encapsulating node.
- tunnel mode may not be applied if SA mode is ANY and policy
does not say "tunnel it". check if we have extra IPv6 header
on the packet after ipsec6_output_tunnel() and call ip6_output()
only if additional IPv6 header is added.
- free the copyed packet before returning.
Obtained from: KAME
- rejects IPv6 packet toward IPv4-mapped address if its source address
is not an IPv4-mapped IPv6 address, since the converted IPv4 packets
would have an unexpected IPv4 source address.
- when V6ONLY socket option is set, discard packets destined to a
v4/ipv4 mapped ipv6 address.
- have PULLDOWN_TEST codepath.
- get rid of in6_mcmatch().
Obtained from: KAME
This is the first of two commits; bringing in the kernel support first.
This can be enabled by compiling a kernel with options TCP_SIGNATURE
and FAST_IPSEC.
For the uninitiated, this is a TCP option which provides for a means of
authenticating TCP sessions which came into being before IPSEC. It is
still relevant today, however, as it is used by many commercial router
vendors, particularly with BGP, and as such has become a requirement for
interconnect at many major Internet points of presence.
Several parts of the TCP and IP headers, including the segment payload,
are digested with MD5, including a shared secret. The PF_KEY interface
is used to manage the secrets using security associations in the SADB.
There is a limitation here in that as there is no way to map a TCP flow
per-port back to an SPI without polluting tcpcb or using the SPD; the
code to do the latter is unstable at this time. Therefore this code only
supports per-host keying granularity.
Whilst FAST_IPSEC is mutually exclusive with KAME IPSEC (and thus IPv6),
TCP_SIGNATURE applies only to IPv4. For the vast majority of prospective
users of this feature, this will not pose any problem.
This implementation is output-only; that is, the option is honoured when
responding to a host initiating a TCP session, but no effort is made
[yet] to authenticate inbound traffic. This is, however, sufficient to
interwork with Cisco equipment.
Tested with a Cisco 2501 running IOS 12.0(27), and Quagga 0.96.4 with
local patches. Patches for tcpdump to validate TCP-MD5 sessions are also
available from me upon request.
Sponsored by: sentex.net
allnodes multicast route if the routing table has not been initialized.
This avoids a panic during boot if an interface detaches before the
routing table is initialized.
Submitted by: sam
