An old route will be NULL at that point if a packet were initially
routed to an interface (using the IP_ROUTETOIF flag.)
Submitted by: Igor Timkin <ivt@gamma.ru>
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
Now that we've increased the size of our send / receive buffers, bursting
an entire window onto the network may cause congestion. As a result,
we will slow start beginning with a flightsize of 4 packets.
Problem reported by: Thomas Zenker <thz@Lennartz-electronic.de>
MFC after: 3 days
Easily exploitable by flood pinging the target
host over an interface with the IFF_NOARP flag
set (all you need to know is the target host's
MAC address).
MFC after: 0 days
mutable contents of struct prison (hostname, securelevel, refcount,
pr_linux, ...)
o Generally introduce mtx_lock()/mtx_unlock() calls throughout kern/
so as to enforce these protections, in particular, in kern_mib.c
protection sysctl access to the hostname and securelevel, as well as
kern_prot.c access to the securelevel for access control purposes.
o Rewrite linux emulator abstractions for accessing per-jail linux
mib entries (osname, osrelease, osversion) so that they don't return
a pointer to the text in the struct linux_prison, rather, a copy
to an array passed into the calls. Likewise, update linprocfs to
use these primitives.
o Update in_pcb.c to always use prison_getip() rather than directly
accessing struct prison.
Reviewed by: jhb
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
o Hide nonstandard functions and types in <netinet/in.h> when
_POSIX_SOURCE is defined.
o Add some missing types (required by POSIX.1-200x) to <netinet/in.h>.
o Restore vendor ID from Rev 1.1 in <netinet/in.h> and make use of new
__FBSDID() macro.
o Fix some miscellaneous issues in <arpa/inet.h>.
o Correct final argument for the inet_ntop() function (POSIX.1-200x).
o Get rid of the namespace pollution from <sys/types.h> in
<arpa/inet.h>.
Reviewed by: fenner
Partially submitted by: bde
interface address, blow the address away again before returning the
error.
In in_ifinit(), if we get an error from rtinit() and we've also got
a destination address, return the error rather than masking EEXISTS.
Failing to create a host route when configuring an interface should
be treated as an error.
received on an interface without an IP address, try to find a
non-loopback AF_INET address to use. If that fails, drop it.
Previously, we used the address at the top of the in_ifaddrhead list,
which didn't make much sense, and would cause a panic if there were no
AF_INET addresses configured on the system.
PR: 29337, 30524
Reviewed by: ru, jlemon
Obtained from: NetBSD
for passive mode data connections (PASV/EPSV -> 227/229). Well,
the actual punching happens a bit later, when the aliasing link
becomes fully specified.
Prodded by: Danny Carroll <dannycarroll@hotmail.com>
MFC after: 1 week
to be followed by nfsnodehashtbl, so bzeroing callouts beyond the end of
tcp_syncache soon caused a null pointer panic when nfsnodehashtbl was
accessed.
vnodes. This will hopefully serve as a base from which we can
expand the MP code. We currently do not attempt to obtain any
mutex or SX locks, but the door is open to add them when we nail
down exactly how that part of it is going to work.
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
"[...] and removes the hostcache code from standard kernels---the
code that depends on it is not going to happen any time soon,
I'm afraid."
Time to clean up.
called and ip_output() encounters an error and bails (i.e. host
unreachable), we will leak an mbuf. This is because the code calls
m_freem(m0) after jumping to the bad: label at the end of the function,
when it should be calling m_freem(m). (m0 is the original mbuf list
_without_ the options mbuf prepended.)
Obtained from: NetBSD
ifconfig, which expects the address returned by the SIOCGIFNETMASK ioctl
to have a valid sa_family. Similar changes may be necessary for IPv6.
While we're here, get rid of an unnecessary temp variable.
MFC after: 2 weeks
is calculated. this caused some trouble in the code which the ip header
is not modified. for example, inbound policy lookup failed.
Obtained from: KAME
MFC after: 1 week
Have sys/net/route.c:rtrequest1(), which takes ``rt_addrinfo *''
as the argument. Pass rt_addrinfo all the way down to rtrequest1
and ifa->ifa_rtrequest. 3rd argument of ifa->ifa_rtrequest is now
``rt_addrinfo *'' instead of ``sockaddr *'' (almost noone is
using it anyways).
Benefit: the following command now works. Previously we needed
two route(8) invocations, "add" then "change".
# route add -inet6 default ::1 -ifp gif0
Remove unsafe typecast in rtrequest(), from ``rtentry *'' to
``sockaddr *''. It was introduced by 4.3BSD-Reno and never
corrected.
Obtained from: BSD/OS, NetBSD
MFC after: 1 month
PR: kern/28360
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
to send all its data, especially when the data is less than one MSS.
This fixes an issue where the stack was delaying the sending
of data, eventhough there was enough window to send all the data and
the sending of data was emptying the socket buffer.
Problem found by Yoshihiro Tsuchiya (tsuchiya@flab.fujitsu.co.jp)
Submitted by: Jayanth Vijayaraghavan
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
+ 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
not referenced in Stevens, and does not compile with g++.
There is an equivalent structure, struct ipoption in ip_var.h
which is actually used in various parts of the kernel, and also referenced
in Stevens.
Bill Fenner also says:
... if you want the trivia, struct ip_opts was introduced
in in.h SCCS revision 7.9, on 6/28/1990, by Mike Karels.
struct ipoption was introduced in ip_var.h SCCS revision 6.5,
on 9/16/1985, by... Mike Karels.
MFC-after: 3 days
NAT in extended passive mode if the server's public IP address was
different from the main NAT address. This caused a wrong aliasing
link to be created that did not route the incoming packets back to
the original IP address of the server.
natd -v -n pub0 -redirect_address localFTP publicFTP
Note that even if localFTP == publicFTP, one still needs to supply
the -redirect_address directive. It is needed as a helper because
extended passive mode's 229 reply does not contain the IP address.
MFC after: 1 week
and speed. No new functionality added (yet) apart from a bugfix.
MFC will occur in due time and probably in stages.
BUGFIX: fix a problem in old code which prevented reallocation of
the hash table for dynamic rules (there is a PR on this).
OTHER CHANGES: minor changes to the internal struct for static and dynamic rules.
Requires rebuild of ipfw binary.
Add comments to show how data structures are linked together.
(It probably makes no sense to keep the chain pointers separate
from actual rule descriptors. They will be hopefully merged soon.
keep a (sysctl-readable) counter for the number of static rules,
to speed up IP_FW_GET operations
initial support for a "grace time" for expired connections, so we
can set timeouts for closing connections to much shorter times.
merge zero_entry() and resetlog_entry(), they use basically the
same code.
clean up and reduce replication of code for removing rules,
both for readability and code size.
introduce a separate lifetime for dynamic UDP rules.
fix a problem in old code which prevented reallocation of
the hash table for dynamic rules (PR ...)
restructure dynamic rule descriptors
introduce some local variables to avoid multiple dereferencing of
pointer chains (reduces code size and hopefully increases speed).
Note ALL MODULES MUST BE RECOMPILED
make the kernel aware that there are smaller units of scheduling than the
process. (but only allow one thread per process at this time).
This is functionally equivalent to teh previousl -current except
that there is a thread associated with each process.
Sorry john! (your next MFC will be a doosie!)
Reviewed by: peter@freebsd.org, dillon@freebsd.org
X-MFC after: ha ha ha ha
new data is acknowledged, reset the dupacks to 0.
The problem was spotted when a connection had its send buffer full
because the congestion window was only 1 MSS and was not being incremented
because dupacks was not reset to 0.
Obtained from: Yahoo!
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>
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
For FTP control connection, keep the CRLF end-of-line termination
status in there.
Fixed the bug when the first FTP command in a session was ignored.
PR: 24048
MFC after: 1 week
other "system" header files.
Also help the deprecation of lockmgr.h by making it a sub-include of
sys/lock.h and removing sys/lockmgr.h form kernel .c files.
Sort sys/*.h includes where possible in affected files.
OK'ed by: bde (with reservations)
