Commit Graph

116 Commits

Author SHA1 Message Date
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
Robert Watson
ce17880650 o Replace reference to 'struct proc' with 'struct thread' in 'struct
sysctl_req', which describes in-progress sysctl requests.  This permits
  sysctl handlers to have access to the current thread, permitting work
  on implementing td->td_ucred, migration of suser() to using struct
  thread to derive the appropriate ucred, and allowing struct thread to be
  passed down to other code, such as network code where td is not currently
  available (and curproc is used).

o Note: netncp and netsmb are not updated to reflect this change, as they
  are not currently KSE-adapted.

Reviewed by:		julian
Obtained from:	TrustedBSD Project
2001-11-08 02:13:18 +00:00
Robert Watson
8a7d8cc675 - Combine kern.ps_showallprocs and kern.ipc.showallsockets into
a single kern.security.seeotheruids_permitted, describes as:
  "Unprivileged processes may see subjects/objects with different real uid"
  NOTE: kern.ps_showallprocs exists in -STABLE, and therefore there is
  an API change.  kern.ipc.showallsockets does not.
- Check kern.security.seeotheruids_permitted in cr_cansee().
- Replace visibility calls to socheckuid() with cr_cansee() (retain
  the change to socheckuid() in ipfw, where it is used for rule-matching).
- Remove prison_unpcb() and make use of cr_cansee() against the UNIX
  domain socket credential instead of comparing root vnodes for the
  UDS and the process.  This allows multiple jails to share the same
  chroot() and not see each others UNIX domain sockets.
- Remove unused socheckproc().

Now that cr_cansee() is used universally for socket visibility, a variety
of policies are more consistently enforced, including uid-based
restrictions and jail-based restrictions.  This also better-supports
the introduction of additional MAC models.

Reviewed by:	ps, billf
Obtained from:	TrustedBSD Project
2001-10-09 21:40:30 +00:00
Paul Saab
4787fd37af Only allow users to see their own socket connections if
kern.ipc.showallsockets is set to 0.

Submitted by:	billf (with modifications by me)
Inspired by:	Dave McKay (aka pm aka Packet Magnet)
Reviewed by:	peter
MFC after:	2 weeks
2001-10-05 07:06:32 +00:00
Robert Watson
94088977c9 o Rename u_cansee() to cr_cansee(), making the name more comprehensible
in the face of a rename of ucred to cred, and possibly generally.

Obtained from:	TrustedBSD Project
2001-09-20 21:45:31 +00:00
Mike Silbersack
b0e3ad758b Much delayed but now present: RFC 1948 style sequence numbers
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
2001-08-22 00:58:16 +00:00
Peter Wemm
57e119f6f2 Fix a warning. 2001-07-27 00:04:39 +00:00
Peter Wemm
016517247f Patch up some style(9) stuff in tcp_new_isn() 2001-07-27 00:03:49 +00:00
Peter Wemm
92971bd3f1 s/OpemBSD/OpenBSD/ 2001-07-27 00:01:48 +00:00
Mike Silbersack
2d610a5028 Temporary feature: Runtime tuneable tcp initial sequence number
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
2001-07-08 02:20:47 +00:00
David Malone
7ce87f1205 Allow getcred sysctl to work in jailed root processes. Processes can
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
2001-06-24 12:18:27 +00:00
Jonathan Lemon
f962cba5c3 Replace bzero() of struct ip with explicit zeroing of structure members,
which is faster.
2001-06-23 17:44:27 +00:00
Mike Silbersack
08517d530e Eliminate the allocation of a tcp template structure for each
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
2001-06-23 03:21:46 +00:00
Hajimu UMEMOTO
ff2428299f made sure to use the correct sa_len for rtalloc().
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
2001-06-20 12:32:48 +00:00
Hajimu UMEMOTO
3384154590 Sync with recent KAME.
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
2001-06-11 12:39:29 +00:00
Peter Wemm
0978669829 "Fix" the previous initial attempt at fixing TUNABLE_INT(). This time
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.
2001-06-08 05:24:21 +00:00
Peter Wemm
4422746fdf Back out part of my previous commit. This was a last minute change
and I botched testing.  This is a perfect example of how NOT to do
this sort of thing. :-(
2001-06-07 03:17:26 +00:00
Peter Wemm
81930014ef Make the TUNABLE_*() macros look and behave more consistantly like the
SYSCTL_*() macros.  TUNABLE_INT_DECL() was an odd name because it didn't
actually declare the int, which is what the name suggests it would do.
2001-06-06 22:17:08 +00:00
Jesper Skriver
d1745f454d Say goodbye to TCP_COMPAT_42
Reviewed by:	wollman
Requested by:	wollman
2001-04-20 11:58:56 +00:00
Kris Kennaway
f0a04f3f51 Randomize the TCP initial sequence numbers more thoroughly.
Obtained from:	OpenBSD
Reviewed by:	jesper, peter, -developers
2001-04-17 18:08:01 +00:00
Jesper Skriver
b77d155dd3 MFC candidate.
Change code from PRC_UNREACH_ADMIN_PROHIB to PRC_UNREACH_PORT for
ICMP_UNREACH_PROTOCOL and ICMP_UNREACH_PORT

And let TCP treat PRC_UNREACH_PORT like PRC_UNREACH_ADMIN_PROHIB

This should fix the case where port unreachables for udp returned
ENETRESET instead of ECONNREFUSED

Problem found by:	Bill Fenner <fenner@research.att.com>
Reviewed by:		jlemon
2001-03-28 14:13:19 +00:00
Poul-Henning Kamp
462b86fe91 <sys/queue.h> makeover. 2001-03-16 20:00:53 +00:00
Jonathan Lemon
c693a045de Remove in_pcbnotify and use in_pcblookup_hash to find the cb directly.
For TCP, verify that the sequence number in the ICMP packet falls within
the tcp receive window before performing any actions indicated by the
icmp packet.

Clean up some layering violations (access to tcp internals from in_pcb)
2001-02-26 21:19:47 +00:00
Jonathan Lemon
c484d1a38c When converting soft error into a hard error, drop the connection. The
error will be passed up to the user, who will close the connection, so
it does not appear to make a sense to leave the connection open.

This also fixes a bug with kqueue, where the filter does not set EOF
on the connection, because the connection is still open.

Also remove calls to so{rw}wakeup, as we aren't doing anything with
them at the moment anyway.

Reviewed by: alfred, jesper
2001-02-23 21:07:06 +00:00
Jonathan Lemon
e4bb5b0572 Allow ICMP unreachables which map into PRC_UNREACH_ADMIN_PROHIB to
reset TCP connections which are in the SYN_SENT state, if the sequence
number in the echoed ICMP reply is correct.  This behavior can be
controlled by the sysctl net.inet.tcp.icmp_may_rst.

Currently, only subtypes 2,3,10,11,12 are treated as such
(port, protocol and administrative unreachables).

Assocaiate an error code with these resets which is reported to the
user application: ENETRESET.

Disallow resetting TCP sessions which are not in a SYN_SENT state.

Reviewed by: jesper, -net
2001-02-23 20:51:46 +00:00
Jesper Skriver
d1c54148b7 Redo the security update done in rev 1.54 of src/sys/netinet/tcp_subr.c
and 1.84 of src/sys/netinet/udp_usrreq.c

The changes broken down:

- remove 0 as a wildcard for addresses and port numbers in
  src/sys/netinet/in_pcb.c:in_pcbnotify()
- add src/sys/netinet/in_pcb.c:in_pcbnotifyall() used to notify
  all sessions with the specific remote address.
- change
  - src/sys/netinet/udp_usrreq.c:udp_ctlinput()
  - src/sys/netinet/tcp_subr.c:tcp_ctlinput()
  to use in_pcbnotifyall() to notify multiple sessions, instead of
  using in_pcbnotify() with 0 as src address and as port numbers.
- remove check for src port == 0 in
  - src/sys/netinet/tcp_subr.c:tcp_ctlinput()
  - src/sys/netinet/udp_usrreq.c:udp_ctlinput()
  as they are no longer needed.
- move handling of redirects and host dead from in_pcbnotify() to
  udp_ctlinput() and tcp_ctlinput(), so they will call
  in_pcbnotifyall() to notify all sessions with the specific
  remote address.

Approved by:	jlemon
Inspired by:    NetBSD
2001-02-22 21:23:45 +00:00
Jesper Skriver
58e9b41722 Only call in_pcbnotify if the src port number != 0, as we
treat 0 as a wildcard in src/sys/in_pbc.c:in_pcbnotify()

It's sufficient to check for src|local port, as we'll have no
sessions with src|local port == 0

Without this a attacker sending ICMP messages, where the attached
IP header (+ 8 bytes) has the address and port numbers == 0, would
have the ICMP message applied to all sessions.

PR:		kern/25195
Submitted by:	originally by jesper, reimplimented by jlemon's advice
Reviewed by:	jlemon
Approved by:	jlemon
2001-02-20 23:25:04 +00:00
Brian Feldman
c0511d3b58 Switch to using a struct xucred instead of a struct xucred when not
actually in the kernel.  This structure is a different size than
what is currently in -CURRENT, but should hopefully be the last time
any application breakage is caused there.  As soon as any major
inconveniences are removed, the definition of the in-kernel struct
ucred should be conditionalized upon defined(_KERNEL).

This also changes struct export_args to remove dependency on the
constantly-changing struct ucred, as well as limiting the bounds
of the size fields to the correct size.  This means: a) mountd and
friends won't break all the time, b) mountd and friends won't crash
the kernel all the time if they don't know what they're doing wrt
actual struct export_args layout.

Reviewed by:	bde
2001-02-18 13:30:20 +00:00
Poul-Henning Kamp
90fcbbd635 Remove unneeded loop increment in src/sys/netinet/in_pcb.c:in_pcbnotify
Add new PRC_UNREACH_ADMIN_PROHIB in sys/sys/protosw.h

Remove condition on TCP in src/sys/netinet/ip_icmp.c:icmp_input

In src/sys/netinet/ip_icmp.c:icmp_input set code = PRC_UNREACH_ADMIN_PROHIB
or PRC_UNREACH_HOST for all unreachables except ICMP_UNREACH_NEEDFRAG

Rename sysctl icmp_admin_prohib_like_rst to icmp_unreach_like_rst
to reflect the fact that we also react on ICMP unreachables that
are not administrative prohibited.  Also update the comments to
reflect this.

In sys/netinet/tcp_subr.c:tcp_ctlinput add code to treat
PRC_UNREACH_ADMIN_PROHIB and PRC_UNREACH_HOST different.

PR:		23986
Submitted by:	Jesper Skriver <jesper@skriver.dk>
2001-02-18 09:34:55 +00:00
Poul-Henning Kamp
fc2ffbe604 Mechanical change to use <sys/queue.h> macro API instead of
fondling implementation details.

Created with: sed(1)
Reviewed by: md5(1)
2001-02-04 13:13:25 +00:00
Poul-Henning Kamp
442fad6798 Update the "icmp_admin_prohib_like_rst" code to check the tcp-window and
to be configurable with respect to acting only in SYN or in all TCP states.

PR:		23665
Submitted by:	Jesper Skriver <jesper@skriver.dk>
2000-12-24 10:57:21 +00:00
Poul-Henning Kamp
b11d7a4a2f We currently does not react to ICMP administratively prohibited
messages send by routers when they deny our traffic, this causes
a timeout when trying to connect to TCP ports/services on a remote
host, which is blocked by routers or firewalls.

rfc1122 (Requirements for Internet Hosts) section 3.2.2.1 actually
requi re that we treat such a message for a TCP session, that we
treat it like if we had recieved a RST.

quote begin.

            A Destination Unreachable message that is received MUST be
            reported to the transport layer.  The transport layer SHOULD
            use the information appropriately; for example, see Sections
            4.1.3.3, 4.2.3.9, and 4.2.4 below.  A transport protocol
            that has its own mechanism for notifying the sender that a
            port is unreachable (e.g., TCP, which sends RST segments)
            MUST nevertheless accept an ICMP Port Unreachable for the
            same purpose.

quote end.

I've written a small extension that implement this, it also create
a sysctl "net.inet.tcp.icmp_admin_prohib_like_rst" to control if
this new behaviour is activated.

When it's activated (set to 1) we'll treat a ICMP administratively
prohibited message (icmp type 3 code 9, 10 and 13) for a TCP
sessions, as if we recived a TCP RST, but only if the TCP session
is in SYN_SENT state.

The reason for only reacting when in SYN_SENT state, is that this
will solve the problem, and at the same time minimize the risk of
this being abused.

I suggest that we enable this new behaviour by default, but it
would be a change of current behaviour, so if people prefer to
leave it disabled by default, at least for now, this would be ok
for me, the attached diff actually have the sysctl set to 0 by
default.

PR:		23086
Submitted by:	Jesper Skriver <jesper@skriver.dk>
2000-12-16 19:42:06 +00:00
Jonathan Lemon
e82ac18e52 Revert the last commit to the callout interface, and add a flag to
callout_init() indicating whether the callout is safe or not.  Update
the callers of callout_init() to reflect the new interface.

Okayed by: Jake
2000-11-25 06:22:16 +00:00
Poul-Henning Kamp
46aa3347cb Convert all users of fldoff() to offsetof(). fldoff() is bad
because it only takes a struct tag which makes it impossible to
use unions, typedefs etc.

Define __offsetof() in <machine/ansi.h>

Define offsetof() in terms of __offsetof() in <stddef.h> and <sys/types.h>

Remove myriad of local offsetof() definitions.

Remove includes of <stddef.h> in kernel code.

NB: Kernelcode should *never* include from /usr/include !

Make <sys/queue.h> include <machine/ansi.h> to avoid polluting the API.

Deprecate <struct.h> with a warning.  The warning turns into an error on
01-12-2000 and the file gets removed entirely on 01-01-2001.

Paritials reviews by:   various.
Significant brucifications by:  bde
2000-10-27 11:45:49 +00:00
Jun-ichiro itojun Hagino
d31944e6ec be careful on mbuf overrun on ctlinput.
short icmp6 packet may be able to panic the kernel.
sync with kame.
2000-10-23 07:11:01 +00:00
Kris Kennaway
be515d91ad Use stronger random number generation for TCP_ISSINCR and tcp_iss.
Reviewed by:	peter, jlemon
2000-09-29 01:37:19 +00:00
Bosko Milekic
9d8c8a672c Finally make do_tcpdrain sysctl live under correct parent, _net_inet_tcp,
as opposed to _debug. Like before, default value remains 1.
2000-09-25 23:40:22 +00:00
Jayanth Vijayaraghavan
e7f3269307 When a connection is being dropped due to a listen queue overflow,
delete the cloned route that is associated with the connection.
This does not exhaust the routing table memory when the system
is under a SYN flood attack. The route entry is not deleted if there
is any prior information cached in it.

Reviewed by: Peter Wemm,asmodai
2000-07-21 23:26:37 +00:00
Jun-ichiro itojun Hagino
686cdd19b1 sync with kame tree as of july00. tons of bug fixes/improvements.
API changes:
- additional IPv6 ioctls
- IPsec PF_KEY API was changed, it is mandatory to upgrade setkey(8).
  (also syntax change)
2000-07-04 16:35:15 +00:00
Poul-Henning Kamp
77978ab8bc Previous commit changing SYSCTL_HANDLER_ARGS violated KNF.
Pointed out by:	bde
2000-07-04 11:25:35 +00:00
Poul-Henning Kamp
82d9ae4e32 Style police catches up with rev 1.26 of src/sys/sys/sysctl.h:
Sanitize SYSCTL_HANDLER_ARGS so that simplistic tools can grog our
sources:

        -sysctl_vm_zone SYSCTL_HANDLER_ARGS
        +sysctl_vm_zone (SYSCTL_HANDLER_ARGS)
2000-07-03 09:35:31 +00:00
Yoshinobu Inoue
34e3e010b6 Let initialize th_sum before in6_cksum(), again.
Without this fix, all IPv6 TCP RST packet has wrong cksum value,
so IPv6 connect() trial to 5.0 machine won't fail until tcp connect timeout,
when they should fail soon.

Thanks to haro@tk.kubota.co.jp (Munehiro Matsuda) for his much debugging
help and detailed info.
2000-04-19 15:05:00 +00:00
Jonathan Lemon
db4f9cc703 Add support for offloading IP/TCP/UDP checksums to NIC hardware which
supports them.
2000-03-27 19:14:27 +00:00
Paul Saab
f885f63606 Limit the maximum permissible TCP window size to 65535 octets if
window scaling is disabled.

PR:		kern/16914
Submitted by:	Jayanth Vijayaraghavan <jayanth@yahoo-inc.com>
Reviewed by:	wollman
Approved by:	jkh
2000-02-28 21:18:21 +00:00
Yoshinobu Inoue
e2de10abe4 Fix the bug that IPv4 ttl is not initialized when AF_INET6 socket is used
for IPv4 communication.(IPv4 mapped IPv6 addr.)
Also removed IPv6 hoplimit initialization because it is alway done at
tcp_output.

Confirmed by: Bernd Walter <ticso@cicely5.cicely.de>
2000-01-25 01:05:18 +00:00
Yoshinobu Inoue
3a2a9f7976 Fixed the problem that IPsec connection hangs when bigger data is sent.
-opt_ipsec.h was missing on some tcp files (sorry for basic mistake)
  -made buildable as above fix
  -also added some missing IPv4 mapped IPv6 addr consideration into
   ipsec4_getpolicybysock
2000-01-15 14:56:38 +00:00
Yoshinobu Inoue
0567ae029a Added missing 'else' for 'if (isipv6)' at IPv6 length setting in tcp_respond().
By this bug, IPv6 reset was not sent.
(I checked around same kind of bug, but no other found.)
2000-01-15 14:34:56 +00:00
Yoshinobu Inoue
595ad28111 Removed wrong(unnecessary) & operators for pointer, in ipsec_hdrsiz_tcp().
This must be one of the reason why connections over IPsec hangs for
bigger packets.(which was reported on freebsd-current@freebsd.org)

But there still seems to be another bug and the problem is not yet fixed.
2000-01-15 05:39:28 +00:00
Yoshinobu Inoue
21ab895ff5 Clear rt after RTFREE. This might have sometime caused kernel panic at rtfree()
on INET6 enabled environment.
2000-01-13 14:21:30 +00:00
Yoshinobu Inoue
72e174286c removed incorrect ip6 length setting for IPv6 tcp reset packet. 2000-01-13 05:18:30 +00:00