case, also preserve the MAC label. Note that this mbuf allocation
is fairly non-optimal, but not my fault.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, NAI Labs
kernel access control.
Instrument the code managing IP fragment reassembly queues (struct ipq)
to invoke appropriate MAC entry points to maintain a MAC label on
each queue. Permit MAC policies to associate information with a queue
based on the mbuf that caused it to be created, update that information
based on further mbufs accepted by the queue, influence the decision
making process by which mbufs are accepted to the queue, and set the
label of the mbuf holding the reassembled datagram following reassembly
completetion.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, NAI Labs
Add XXX comments to mark places which need to be taken care of
if we want to remove this part of the kernel from Giant.
Add a comment on a potential performance problem with ip_forward()
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
o Add a mutex (sb_mtx) to struct sockbuf. This protects the data in a
socket buffer. The mutex in the receive buffer also protects the data
in struct socket.
o Determine the lock strategy for each members in struct socket.
o Lock down the following members:
- so_count
- so_options
- so_linger
- so_state
o Remove *_locked() socket APIs. Make the following socket APIs
touching the members above now require a locked socket:
- sodisconnect()
- soisconnected()
- soisconnecting()
- soisdisconnected()
- soisdisconnecting()
- sofree()
- soref()
- sorele()
- sorwakeup()
- sotryfree()
- sowakeup()
- sowwakeup()
Reviewed by: alfred
were totally useless and have been removed.
ip_input.c, ip_output.c:
Properly initialize the "ip" pointer in case the firewall does an
m_pullup() on the packet.
Remove some debugging code forgotten long ago.
ip_fw.[ch], bridge.c:
Prepare the grounds for matching MAC header fields in bridged packets,
so we can have 'etherfw' functionality without a lot of kernel and
userland bloat.
most cases NULL is passed, but in some cases such as network driver locks
(which use the MTX_NETWORK_LOCK macro) and UMA zone locks, a name is used.
Tested on: i386, alpha, sparc64
deprecated in favor of the POSIX-defined lowercase variants.
o Change all occurrences of NTOHL() and associated marcros in the
source tree to use the lowercase function variants.
o Add missing license bits to sparc64's <machine/endian.h>.
Approved by: jake
o Clean up <machine/endian.h> files.
o Remove unused __uint16_swap_uint32() from i386's <machine/endian.h>.
o Remove prototypes for non-existent bswapXX() functions.
o Include <machine/endian.h> in <arpa/inet.h> to define the
POSIX-required ntohl() family of functions.
o Do similar things to expose the ntohl() family in libstand, <netinet/in.h>,
and <sys/param.h>.
o Prepend underscores to the ntohl() family to help deal with
complexities associated with having MD (asm and inline) versions, and
having to prevent exposure of these functions in other headers that
happen to make use of endian-specific defines.
o Create weak aliases to the canonical function name to help deal with
third-party software forgetting to include an appropriate header.
o Remove some now unneeded pollution from <sys/types.h>.
o Add missing <arpa/inet.h> includes in userland.
Tested on: alpha, i386
Reviewed by: bde, jake, tmm
some time. _All_ packets, regardless of destination, were accepted by
the machine as if addressed to it.
Jump back to 'pass' processing for a teed packet instead of falling
through as if it was ours.
PR: kern/31130
Reviewed by: -net, luigi
MFC after: 2 weeks
The following steps are involved:
a) the IP options related to routing (LSRR and SSRR) are processed
as though the router were a host,
b) the other IP options are processed as usual only if the packet
is destined for the router; otherwise they are ignored.
PR: kern/23123
Discussed in: freebsd-hackers
+ implement "limit" rules, which permit to limit the number of sessions
between certain host pairs (according to masks). These are a special
type of stateful rules, which might be of interest in some cases.
See the ipfw manpage for details.
+ merge the list pointers and ipfw rule descriptors in the kernel, so
the code is smaller, faster and more readable. This patch basically
consists in replacing "foo->rule->bar" with "rule->bar" all over
the place.
I have been willing to do this for ages!
MFC after: 1 week
to the application as a RST would, this way we're compatible with the most
applications.
MFC candidate.
Submitted by: Scott Renfro <scott@renfro.org>
Reviewed by: Mike Silbersack <silby@silby.com>
This work was based on kame-20010528-freebsd43-snap.tgz and some
critical problem after the snap was out were fixed.
There are many many changes since last KAME merge.
TODO:
- The definitions of SADB_* in sys/net/pfkeyv2.h are still different
from RFC2407/IANA assignment because of binary compatibility
issue. It should be fixed under 5-CURRENT.
- ip6po_m member of struct ip6_pktopts is no longer used. But, it
is still there because of binary compatibility issue. It should
be removed under 5-CURRENT.
Reviewed by: itojun
Obtained from: KAME
MFC after: 3 weeks
A attacker sending a lot of bogus fragmented packets to the target
(with different IPv4 identification field - ip_id), may be able
to put the target machine into mbuf starvation state.
By setting a upper limit on the number of reassembly queues we
prevent this situation.
This upper limit is controlled by the new sysctl
net.inet.ip.maxfragpackets which defaults to 200,
as the IPv6 case, this should be sufficient for most
systmes, but you might want to increase it if you have
lots of TCP sessions.
I'm working on making the default value dependent on
nmbclusters.
If you want old behaviour (no upper limit) set this sysctl
to a negative value.
If you don't want to accept any fragments (not recommended)
set the sysctl to 0 (zero).
Obtained from: NetBSD
MFC after: 1 week
This closes a minor information leak which allows a remote observer to
determine the rate at which the machine is generating packets, since the
default behaviour is to increment a counter for each packet sent.
Reviewed by: -net
Obtained from: OpenBSD
A attacker sending a lot of bogus fragmented packets to the target
(with different IPv4 identification field - ip_id), may be able
to put the target machine into mbuf starvation state.
By setting a upper limit on the number of reassembly queues we
prevent this situation.
This upper limit is controlled by the new sysctl
net.inet.ip.maxfragpackets which defaults to NMBCLUSTERS/4
If you want old behaviour (no upper limit) set this sysctl
to a negative value.
If you don't want to accept any fragments (not recommended)
set the sysctl to 0 (zero)
Obtained from: NetBSD (partially)
MFC after: 1 week
using it. Not checking this may have caused the wrong IP address to be
used when processing certain IP options (see example below). This also
caused the wrong route to be passed to ip_output() when forwarding, but
fortunately ip_output() is smart enough to detect this.
This example demonstrates the wrong behavior of the Record Route option
observed with this bug. Host ``freebsd'' is acting as the gateway for
the ``sysv''.
1. On the gateway, we add the route to the destination. The new route
will use the primary address of the loopback interface, 127.0.0.1:
: freebsd# route add 10.0.0.66 -iface lo0 -reject
: add host 10.0.0.66: gateway lo0
2. From the client, we ping the destination. We see the correct replies.
Please note that this also causes the relevant route on the ``freebsd''
gateway to be cached in ipforward_rt variable:
: sysv# ping -snv 10.0.0.66
: PING 10.0.0.66: 56 data bytes
: ICMP Host Unreachable from gateway 192.168.0.115
: ICMP Host Unreachable from gateway 192.168.0.115
: ICMP Host Unreachable from gateway 192.168.0.115
:
: ----10.0.0.66 PING Statistics----
: 3 packets transmitted, 0 packets received, 100% packet loss
3. On the gateway, we delete the route to the destination, thus making
the destination reachable through the `default' route:
: freebsd# route delete 10.0.0.66
: delete host 10.0.0.66
4. From the client, we ping destination again, now with the RR option
turned on. The surprise here is the 127.0.0.1 in the first reply.
This is caused by the bug in ip_rtaddr() not checking the cached
route is still up befor use. The debug code also shows that the
wrong (down) route is further passed to ip_output(). The latter
detects that the route is down, and replaces the bogus route with
the valid one, so we see the correct replies (192.168.0.115) on
further probes:
: sysv# ping -snRv 10.0.0.66
: PING 10.0.0.66: 56 data bytes
: 64 bytes from 10.0.0.66: icmp_seq=0. time=10. ms
: IP options: <record route> 127.0.0.1, 10.0.0.65, 10.0.0.66,
: 192.168.0.65, 192.168.0.115, 192.168.0.120,
: 0.0.0.0(Current), 0.0.0.0, 0.0.0.0
: 64 bytes from 10.0.0.66: icmp_seq=1. time=0. ms
: IP options: <record route> 192.168.0.115, 10.0.0.65, 10.0.0.66,
: 192.168.0.65, 192.168.0.115, 192.168.0.120,
: 0.0.0.0(Current), 0.0.0.0, 0.0.0.0
: 64 bytes from 10.0.0.66: icmp_seq=2. time=0. ms
: IP options: <record route> 192.168.0.115, 10.0.0.65, 10.0.0.66,
: 192.168.0.65, 192.168.0.115, 192.168.0.120,
: 0.0.0.0(Current), 0.0.0.0, 0.0.0.0
:
: ----10.0.0.66 PING Statistics----
: 3 packets transmitted, 3 packets received, 0% packet loss
: round-trip (ms) min/avg/max = 0/3/10
an IP header with ip_len in network byte order. For certain
values of ip_len, this could cause icmp_error() to write
beyond the end of an mbuf, causing mbuf free-list corruption.
This problem was observed during generation of ICMP redirects.
We now make quite sure that the copy of the IP header kept
for icmp_error() is stored in a non-shared mbuf header so
that it will not be modified by ip_output().
Also:
- Calculate the correct number of bytes that need to be
retained for icmp_error(), instead of assuming that 64
is enough (it's not).
- In icmp_error(), use m_copydata instead of bcopy() to
copy from the supplied mbuf chain, in case the first 8
bytes of IP payload are not stored directly after the IP
header.
- Sanity-check ip_len in icmp_error(), and panic if it is
less than sizeof(struct ip). Incoming packets with bad
ip_len values are discarded in ip_input(), so this should
only be triggered by bugs in the code, not by bad packets.
This patch results from code and suggestions from Ruslan, Bosko,
Jonathan Lemon and Matt Dillon, with important testing by Mike
Tancsa, who could reproduce this problem at will.
Reported by: Mike Tancsa <mike@sentex.net>
Reviewed by: ru, bmilekic, jlemon, dillon
it doesn't block packets whose destination address has been translated to
the loopback net by ipnat.
Add warning comments about the ip_checkinterface feature.
