Commit Graph

25 Commits

Author SHA1 Message Date
Mike Silbersack
a9ce5e05b5 Handle PMTU discovery in syn-ack packets slightly differently;
rely on syncache flags instead of directly accessing the route
entry.

MFC after:	3 days
2002-08-05 22:34:15 +00:00
Robert Watson
c488362e1a Introduce support for Mandatory Access Control and extensible
kernel access control.

Instrument the TCP socket code for packet generation and delivery:
label outgoing mbufs with the label of the socket, and check socket and
mbuf labels before permitting delivery to a socket.  Assign labels
to newly accepted connections when the syncache/cookie code has done
its business.  Also set peer labels as convenient.  Currently,
MAC policies cannot influence the PCB matching algorithm, so cannot
implement polyinstantiation.  Note that there is at least one case
where a PCB is not available due to the TCP packet not being associated
with any socket, so we don't label in that case, but need to handle
it in a special manner.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, NAI Labs
2002-07-31 19:06:49 +00:00
Jonathan Lemon
0080a004d7 One possible code path for syncache_respond() is:
syncache_respond(A), ip_output(), ip_input(), tcp_input(), syncache_badack(B)

Which winds up deleting a different entry from the syncache.  Handle
this by not utilizing the next entry in the timer chain until after
syncache_respond() completes.  The case of A == B should not be possible.

Problem found by: Don Bowman <don@sandvine.com>
2002-06-28 19:12:38 +00:00
Mike Silbersack
eb5afeba22 Re-commit w/fix:
Ensure that the syn cache's syn-ack packets contain the same
  ip_tos, ip_ttl, and DF bits as all other tcp packets.

  PR:             39141
  MFC after:      2 weeks

This time, make sure that ipv4 specific code (aka all of the above)
is only run in the ipv4 case.
2002-06-14 03:08:05 +00:00
Mike Silbersack
70d2b17029 Back out ip_tos/ip_ttl/DF "fix", it just panic'd my box. :)
Pointy-hat to:	silby
2002-06-14 02:43:20 +00:00
Mike Silbersack
21c3b2fc69 Ensure that the syn cache's syn-ack packets contain the same
ip_tos, ip_ttl, and DF bits as all other tcp packets.

PR:		39141
MFC after:	2 weeks
2002-06-14 02:36:34 +00:00
Jeffrey Hsu
e98d6424af Every array elt is initialized in the following loop, so remove
unnecessary M_ZERO.
2002-06-10 23:48:37 +00:00
Jeffrey Hsu
f76fcf6d4c Lock up inpcb.
Submitted by:	Jennifer Yang <yangjihui@yahoo.com>
2002-06-10 20:05:46 +00:00
Robert Watson
f83c7ad731 Modify the arguments to syncache_socket() to include the mbuf (m) that
results in the syncache entry being turned into a socket.  While it's
not used in the main tree, this is required in the MAC tree so that
labels can be propagated from the mbuf to the socket.  This is also
useful if you're doing things like transparent IP connection hijacking
and you want to use the syncache/cookie mechanism, but we won't go
there.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, NAI Labs
2002-05-14 18:57:55 +00:00
Jeff Roberson
69c2d429c1 Switch vm_zone.h with uma.h. Change over to uma interfaces. 2002-03-20 05:48:55 +00:00
Jeff Roberson
8355f576a9 This is the first part of the new kernel memory allocator. This replaces
malloc(9) and vm_zone with a slab like allocator.

Reviewed by:	arch@
2002-03-19 09:11:49 +00:00
Robert Watson
16aae019a0 NAI DBA update 2002-03-14 16:53:39 +00:00
Hajimu UMEMOTO
b7d6d9526c - Set inc_isipv6 in tcp6_usr_connect().
- When making a pcb from a sync cache, do not forget to copy inc_isipv6.

Obtained from:	KAME
MFC After:	1 week
2002-02-28 17:11:10 +00:00
Jonathan Lemon
6b33ceb8e3 When expanding a syncache entry into a socket, inherit the socket options
from the current listen socket instead of the cached (and possibly stale)
TCB pointer.
2002-02-20 16:47:11 +00:00
Jonathan Lemon
0cab7c4b08 When a duplicate SYN arrives which matches an entry in the syncache,
update our lazy reference to the inpcb structure, as it may have changed.

Found by: dima
2002-02-12 02:03:50 +00:00
Julian Elischer
079b7badea Pre-KSE/M3 commit.
this is a low-functionality change that changes the kernel to access the main
thread of a process via the linked list of threads rather than
assuming that it is embedded in the process. It IS still embeded there
but remove all teh code that assumes that in preparation for the next commit
which will actually move it out.

Reviewed by: peter@freebsd.org, gallatin@cs.duke.edu, benno rice,
2002-02-07 20:58:47 +00:00
Jonathan Lemon
d9b7cc1c8d The ENDPTS_EQ macro was comparing the one of the fports to itself. Fix.
Submitted by: emy@boostworks.com
2002-01-22 17:54:28 +00:00
Jonathan Lemon
45a0329051 If syncookies are disabled (net.inet.tcp.syncookies) then use the faster
arc4random() routine to generate ISNs instead of creating them with MD5().

Suggested by: silby
2001-12-21 04:41:08 +00:00
Jonathan Lemon
e579ba1aea When storing an int value in a void *, use intptr_t as the cast type
(instead of int) to keep the 64 bit platforms happy.
2001-12-19 15:57:43 +00:00
Jonathan Lemon
a9c9684163 Extend the SYN DoS defense by adding syncookies to the syncache.
All TCP ISNs that are sent out are valid cookies, which allows entries
in the syncache to be dropped and still have the ACK accepted later.
As all entries pass through the syncache, there is no sudden switchover
from cache -> cookies when the cache is full; instead, syncache entries
simply have a reduced lifetime.  More details may be found in the
"Resisting DoS attacks with a SYN cache" paper in the Usenix BSDCon 2002
conference proceedings.

Sponsored by: DARPA, NAI Labs
2001-12-19 06:12:14 +00:00
Jonathan Lemon
04cad5adb1 Undo one of my last minute changes; move sc_iss up earlier so it
is initialized in case we take the T/TCP path.
2001-12-13 04:05:26 +00:00
Matthew Dillon
262c1c1a4e Fix a bug with transmitter restart after receiving a 0 window. The
receiver was not sending an immediate ack with delayed acks turned on
when the input buffer is drained, preventing the transmitter from
restarting immediately.

Propogate the TCP_NODELAY option to accept()ed sockets.  (Helps tbench and
is a good idea anyway).

Some cleanup.  Identify additonal issues in comments.

MFC after:	1 day
2001-12-02 08:49:29 +00:00
Seigo Tanimura
df89626872 Clear a new syncache entry first, followed by filling in values. This
fixes route breakage due to uncleared gabage on my box.
2001-11-27 11:55:28 +00:00
Bruce Evans
419d3454b1 Fixed a buffer overrun. In my kernel configuration, tcp_syncache happens
to be followed by nfsnodehashtbl, so bzeroing callouts beyond the end of
tcp_syncache soon caused a null pointer panic when nfsnodehashtbl was
accessed.
2001-11-23 12:31:27 +00:00
Jonathan Lemon
be2ac88c59 Introduce a syncache, which enables FreeBSD to withstand a SYN flood
DoS in an improved fashion over the existing code.

Reviewed by: silby  (in a previous iteration)
Sponsored by: DARPA, NAI Labs
2001-11-22 04:50:44 +00:00