about rules and dynamic rules. it later fills this buffer with these
rules.
it also takes the opporunity to compare the expiration of the dynamic
rules with the current time and either marks them for deletion or simply
charges the countdown.
unfortunatly it does this all (the sizing, the buffer copying, and the
expiration GC) with no spl protection whatsoever. it was possible for
the dynamic rule(s) to be ripped out from under the request before it
had completed, resulting in corrupt memory dereferencing.
Reviewed by: ps
MFC before: 4.4-RELEASE, hopefully.
In order to ensure security and functionality, RFC 1948 style
initial sequence number generation has been implemented. Barring
any major crypographic breakthroughs, this algorithm should be
unbreakable. In addition, the problems with TIME_WAIT recycling
which affect our currently used algorithm are not present.
Reviewed by: jesper
cdevsw entries have been for a long time.
Discover that we now have two version sof the same structure.
I will shoot one of them shortly when I figure out why someone thinks
they need it. (And I can prove they don't)
(netinet/ipprotosw.h should GO AWAY)
Avoid using parenthesis enclosure macros (.Pq and .Po/.Pc) with plain text.
Not only this slows down the mdoc(7) processing significantly, but it also
has an undesired (in this case) effect of disabling hyphenation within the
entire enclosed block.
making pcbs available to the outside world. otherwise, we will see
inpcb without ipsec security policy attached (-> panic() in ipsec.c).
Obtained from: KAME
MFC after: 3 days
- Use sysctl to export stats
- Use ip_encap.c's encapsulation support
- Update lkm to kld (is 6 years a record for a broken module?)
- Remove some unused cruft
This macro was supposed to only match local IP addresses of
interfaces, and all consumers of this macro assume this as
well. (See IP_MULTICAST_IF and IP_ADD_MEMBERSHIP socket
options in the ip(4) manpage.)
This fixes a major security breach in IPFW-based firewalls
where the `me' keyword would match the other end of a P2P
link.
PR: kern/28567
This should help us in nieve benchmark "tests".
It seems a wide number of people think 32k buffers would not cause major
issues, and is in fact in use by many other OS's at this time. The
receive buffers can be bumped higher as buffers are hardly used and several
research papers indicate that receive buffers rarely use much space at all.
Submitted by: Leo Bicknell <bicknell@ufp.org>
<20010713101107.B9559@ussenterprise.ufp.org>
Agreed to in principle by: dillon (at the 32k level)
generation scheme. Users may now select between the currently used
OpenBSD algorithm and the older random positive increment method.
While the OpenBSD algorithm is more secure, it also breaks TIME_WAIT
handling; this is causing trouble for an increasing number of folks.
To switch between generation schemes, one sets the sysctl
net.inet.tcp.tcp_seq_genscheme. 0 = random positive increments,
1 = the OpenBSD algorithm. 1 is still the default.
Once a secure _and_ compatible algorithm is implemented, this sysctl
will be removed.
Reviewed by: jlemon
Tested by: numerous subscribers of -net
RTF_DYNAMIC route, it got freed twice). I am not sure what was
the actual problem in 1992, but the current behavior is memory
leak if PCB holds a reference to a dynamically created/modified
routing table entry. (rt_refcnt>0 and we don't call rtfree().)
My test bed was:
1. Set net.inet.tcp.msl to a low value (for test purposes), e.g.,
5 seconds, to speed up the transition of TCP connection to a
"closed" state.
2. Add a network route which causes ICMP redirect from the gateway.
3. ping(8) host H that matches this route; this creates RTF_DYNAMIC
RTF_HOST route to H. (I was forced to use ICMP to cause gateway
to generate ICMP host redirect, because gateway in question is a
4.2-STABLE system vulnerable to a problem that was fixed later in
ip_icmp.c,v 1.39.2.6, and TCP packets with DF bit set were
triggering this bug.)
4. telnet(1) to H
5. Block access to H with ipfw(8)
6. Send something in telnet(1) session; this causes EPERM, followed
by an in_losing() call in a few seconds.
7. Delete ipfw(8) rule blocking access to H, and wait for TCP
connection moving to a CLOSED state; PCB is freed.
8. Delete host route to H.
9. Watch with netstat(1) that `rttrash' increased.
10. Repeat steps 3-9, and watch `rttrash' increases.
PR: kern/25421
MFC after: 2 weeks
only do getcred calls for sockets which were created in the same jail.
This should allow the ident to work in a reasonable way within jails.
PR: 28107
Approved by: des, rwatson
connection. The information contained in a tcptemp can be
reconstructed from a tcpcb when needed.
Previously, tcp templates required the allocation of one
mbuf per connection. On large systems, this change should
free up a large number of mbufs.
Reviewed by: bmilekic, jlemon, ru
MFC after: 2 weeks
are duplicated by newly defined types/options in RFC3121
- We have no backward compatibility issue. There is no apps in our
distribution which use the above types/options.
Obtained from: KAME
MFC after: 2 weeks
sizeof(ro_dst) is not necessarily the correct one.
this change would also fix the recent path MTU discovery problem for the
destination of an incoming TCP connection.
Submitted by: JINMEI Tatuya <jinmei@kame.net>
Obtained from: KAME
MFC after: 2 weeks
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
around, use a common function for looking up and extracting the tunables
from the kernel environment. This saves duplicating the same function
over and over again. This way typically has an overhead of 8 bytes + the
path string, versus about 26 bytes + the path string.
One way we can reduce the amount of traffic we send in response to a SYN
flood is to eliminate the RST we send when removing a connection from
the listen queue. Since we are being flooded, we can assume that the
majority of connections in the queue are bogus. Our RST is unwanted
by these hosts, just as our SYN-ACK was. Genuine connection attempts
will result in hosts responding to our SYN-ACK with an ACK packet. We
will automatically return a RST response to their ACK when it gets to us
if the connection has been dropped, so the early RST doesn't serve the
genuine class of connections much. In summary, we can reduce the number
of packets we send by a factor of two without any loss in functionality
by ensuring that RST packets are not sent when dropping a connection
from the listen queue.
Submitted by: Mike Silbersack <silby@silby.com>
Reviewed by: jesper
MFC after: 2 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
any response to our third SYN to work-around some broken
terminal servers (most of which have hopefully been retired)
that have bad VJ header compression code which trashes TCP
segments containing unknown-to-them TCP options.
PR: kern/1689
Submitted by: jesper
Reviewed by: wollman
MFC after: 2 weeks
