drop the oldest entry in the queue.
There was a fair bit of discussion as to whether or not the
proper action is to drop a random entry in the queue. It's
my conclusion that a random drop is better than a head drop,
however profiling this section of code (done by John Capo)
shows that a head-drop results in a significant performance
increase.
There are scenarios where a random drop is more appropriate.
If I find one in reality, I'll add the random drop code under
a conditional.
Obtained from: discussions and code done by Vernon Schryver (vjs@sgi.com).
time, in seconds, that state for non-established TCP sessions stays about)
a sysctl modifyable variable.
[part 1 of two commits, I just realized I can't play with the indices as
I was typing this commit message.]
to "keepidle". this should not occur unless the connection has
been established via the 3-way handshake which requires an ACK
Submitted by: jmb
Obtained from: problem discussed in Stevens vol. 3
IPPORT_RESERVED that is used for selection when bind() is told to allocate
a reserved port.
Also, implement simple sanity checking for all the addresses set, to make
it a little harder for a user/sysadmin to shoot themselves in the feet.
pulled up already. This bug can cause the first packet from a source
to a group to be corrupted when it is delivered to a process listening
on the mrouter.
pr_usrreq mechanism which was poorly designed and error-prone. This
commit renames pr_usrreq to pr_ousrreq so that old code which depended on it
would break in an obvious manner. This commit also implements the new
interface for TCP, although the old function is left as an example
(#ifdef'ed out). This commit ALSO fixes a longstanding bug in the
TCP timer processing (introduced by davidg on 1995/04/12) which caused
timer processing on a TCB to always stop after a single timer had
expired (because it misinterpreted the return value from tcp_usrreq()
to indicate that the TCB had been deleted). Finally, some code
related to polling has been deleted from if.c because it is not
relevant t -current and doesn't look at all like my current code.
This stuff should not be too destructive if the IPDIVERT is not compiled in..
be aware that this changes the size of the ip_fw struct
so ipfw needs to be recompiled to use it.. more changes coming to clean this up.
- State when we've reached the limit on a particular rule in the kernel logfile
- State when a rule or all rules have been zero'd.
This gives a log of all actions that occur w/regard to the firewall
occurances, and can explain why a particular break-in attempt might not
get logged due to the limit being reached.
Reviewed by: alex
Reviewed by: phk
Reject the addition of rules that will never match (for example,
1.2.3.4:255.255.255.0). User level utilities specify the policy by either
masking the IP address for the user (as ipfw(8) does) or rejecting the
entry with an error. In either case, the kernel should not modify chain
entries to make them work.
LKM'ness. ACTUALLY_LKM_NOT_KERNEL is supposed to be so ugly that it
only gets used until <machine/conf.h> goes away. bsd.kmod.mk should
define a better-named general macro for this. Some places use
PSEUDO_LKM. This is another bad name.
Makefile:
Added IPFIREWALL_VERBOSE_LIMIT option (commented out).
broadcast and multicast routes, otherwise they will be expired by
arptimeout after a few minutes, reverting to " (incomplete)". This makes
the work done by rev 1.27 stay around until the route itself is deleted.
This is mainly cosmetic for 'arp' and 'netstat -r'.
for ARP requests.
The NetBSD version of this patch (see NetBSD PR kern/2381) has this change
already. This should close our PR kern/1140 .
Although it's not quite what he submitted, I got the idea from him so
Submitted by: Jin Guojun <jin@george.lbl.gov>
/kernel: in_rtqtimo: adjusted rtq_reallyold to 1066
/kernel: in_rtqtimo: adjusted rtq_reallyold to 710
inside of #ifdef DIAGNOSTIC to avoid the support questions from folks
asking what this means.
- Log ICMP type during verbose output.
- Added IPFIREWALL_VERBOSE_LIMIT option to prevent denial of service
attacks via syslog flooding.
- Filter based on ICMP type.
- Timestamp chain entries when they are matched.
- Interfaces can now be matched with a wildcard specification (i.e.
will match any interface unit for a given name).
- Prevent the firewall chain from being manipulated when securelevel
is greater than 2.
- Fixed bug that allowed the default policy to be deleted.
- Ability to zero individual accounting entries.
- Remove definitions of old_chk_ptr and old_ctl_ptr when compiling
ipfw as a lkm.
- Remove some redundant code shared between ip_fw_init and ipfw_load.
Closes PRs: 1192, 1219, and 1267.
gcc only inlines memcpy()'s whose count is constant and didn't inline
these. I want memcpy() in the kernel go away so that it's obvious that
it doesn't need to be optimized. Now it is only used for one struct
copy in si.c.
circumstances, caused perfectly good connections to be dropped. This
happened for connections over a LAN, where the retransmit timer
calculation TCP_REXMTVAL(tp) returned 0. If sending was blocked by flow
control for long enough, the old code dropped the connection, even
though timely replies were being received for all window probes.
Reviewed by: W. Richard Stevens <rstevens@noao.edu>
unconventionally:
If COMPAT_IPFW is not defined, or if it is defined to 1, enable;
otherwise, disable.
This means that these changes actually have no effect on anyone at the
moment. (It just makes it easier for me to keep my code in sync.)
In the future, the `not defined' part of the hack should be eliminated,
but doing this now would require everyone to change their config files.
The same conditionals need to be made in ip_input.c as well for this to
ave any useful effect, but I'm not ready to do that right now.
(PR #1178).
Define a new SO_TIMESTAMP socket option for datagram sockets to return
packet-arrival timestamps as control information (PR #1179).
Submitted by: Louis Mamakos <loiue@TransSys.com>
the destination represents. For IP:
- Iff it is a host route, RTF_LOCAL and RTF_BROADCAST indicate local
(belongs to this host) and broadcast addresses, respectively.
- For all routes, RTF_MULTICAST is set if the destination is multicast.
The RTF_BROADCAST flag is used by ip_output() to eliminate a call to
in_broadcast() in a common case; this gives about 1% in our packet-generation
experiments. All three flags might be used (although they aren't now)
to determine whether a packet can be forwarded; a given host route can
represent a forwardable address if:
(rt->rt_flags & (RTF_HOST | RTF_LOCAL | RTF_BROADCAST | RTF_MULTICAST))
== RTF_HOST
Obviously, one still has to do all the work if a host route is not present,
but this code allows one to cache the results of such a lookup if rtalloc1()
is called without masking RTF_PRCLONING.
1) Require all callers to pass a valid route pointer to ip_output()
so that we don't have to check and allocate one off the stack
as was done before. This eliminates one test and some stack
bloat from the common (UDP and TCP) case.
2) Perform the IP header checksum in-line if it's of the usual length.
This results in about a 5% speed-up in my packet-generation test.
3) Use ip_vhl field rather than ip_v and ip_hl bitfields.
1) Set the persist timer to help time-out connections in the CLOSING state.
2) Honor the keep-alive timer in the CLOSING state.
This fixes problems with connections getting "stuck" due to incompletion
of the final connection shutdown which can be a BIG problem on busy WWW
servers.
common labels for LINT. There are still some common declarations for the
!KERNEL case in tcp_debug.h and spx_debug.h. trpt depends on the ones in
tcp_debug.h.
This fixes a panic that occurs when ifconfig ioctl(s) were interrupted
by IP traffic at the wrong time - resulting in a NULL pointer dereference.
This was originally noticed on a FreeBSD 1.0 system, but the problem still
exists in current sources.
keepalive on all tcp sessions. Setsockopt(2) cannot override this setting.
Maybe another one is needed that just changes the default for SO_KEEPALIVE ?
Requested by: Joe Greco <jgreco@brasil.moneng.mei.com>
Move ipip_input() and rsvp_input() prototypes to ip_var.h
Remove unused prototype for rip_ip_input() from ip_var.h
Remove unused variable *opts from rip_output()
Get rid of ac->ac_ipaddr and arpwhohas() since they assume that
an interface has only one address.
Obtained from: BSD/OS 2.1, via Rich Stevens <rstevens@noao.edu>
from Larry Peterson &co. at Arizona:
- Header prediction for ACKs did not exclude Fast Retransmit/Recovery.
- srtt calculation tended to get ``stuck'' and could never decrease
when below 8. It still can't, but the scaling factors are adjusted
so that this artifact does not cause as bad an effect on the RTO
value as it used to.
The paper also points out the incr/8 error that has been long since fixed,
and the problems with ACKing frequency resulting from the use of options
which I suspect to be fixed already as well (as part of the T/TCP work).
Obtained from: Brakmo & Peterson, ``Performance Problems in BSD4.4 TCP''
between ignoring options specified in the setsockopt call if IP_HDRINCL is set
(the UCB choice when VJ's code was brought in) vs allowing them (what everyone
else did, and what is assumed by programs everywhere...sigh).
Also perform some checking of the passed down packet to avoid running off
the end of a mbuf chain.
Reviewed by: fenner
Make a copy of the header of a packet that gets queued due to
lack of forwarding cache entry, so that nobody else can step
on it. Thanks to Mike Karels <karels@bsdi.com> for pointing
this one out.
Close the ip-fragment hole.
Waste less memory.
Rewrite to contemporary more readable style.
Kill separate IPACCT facility, use "accept" rules in IPFIREWALL.
Filter incoming >and< outgoing packets.
Replace "policy" by sticky "deny all" rule.
Rules have numbers used for ordering and deletion.
Remove "rerorder" code entirely.
Count packet & bytecount matches for rules.
Code in -current & -stable is now the same.
systems (my last change did not mix well with some firewall
configurations). As much as I dislike firewalls, this is one thing I
I was not prepared to break by default.. :-)
Allow the user to nominate one of three ranges of port numbers as
candidates for selecting a local address to replace a zero port number.
The ranges are selected via a setsockopt(s, IPPROTO_IP, IP_PORTRANGE, &arg)
call. The three ranges are: default, high (to bypass firewalls) and
low (to get a port below 1024).
The default and high port ranges are sysctl settable under sysctl
net.inet.ip.portrange.*
This code also fixes a potential deadlock if the system accidently ran out
of local port addresses. It'd drop into an infinite while loop.
The secure port selection (for root) should reduce overheads and increase
reliability of rlogin/rlogind/rsh/rshd if they are modified to take
advantage of it.
Partly suggested by: pst
Reviewed by: wollman
