Prior to this change, Accidental recursion protection was done by
the diverted daemon feeding back the divert port number it got
the packet on, as the port number on a sendto(). IPFW knew not to
redivert a packet to this port (again). Processing of the ruleset
started at the beginning again, skipping that divert port.
The new semantic (which is how we should have done it the first time)
is that the port number in the sendto() is the rule number AFTER which
processing should restart, and on a recvfrom(), the port number is the
rule number which caused the diversion. This is much more flexible,
and also more intuitive. If the user uses the same sockaddr received
when resending, processing resumes at the rule number following that
that caused the diversion. The user can however select to resume rule
processing at any rule. (0 is restart at the beginning)
To enable the new code use
option IPFW_DIVERT_RESTART
This should become the default as soon as people have looked at it a bit
hope i've found out all files that actually depend on this dependancy.
IMHO, it's not very good practice to change the size of internal
structs depending on kernel options.
Distribute all but the most fundamental malloc types. This time I also
remembered the trick to making things static: Put "static" in front of
them.
A couple of finer points by: bde
these are quite extensive additions to the ipfw code.
they include a change to the API because the old method was
broken, but the user view is kept the same.
The new code allows a particular match to skip forward to a particular
line number, so that blocks of rules can be
used without checking all the intervening rules.
There are also many more ways of rejecting
connections especially TCP related, and
many many more ...
see the man page for a complete description.
This commit includes the following changes:
1) Old-style (pr_usrreq()) protocols are no longer supported, the compatibility
glue for them is deleted, and the kernel will panic on boot if any are compiled
in.
2) Certain protocol entry points are modified to take a process structure,
so they they can easily tell whether or not it is possible to sleep, and
also to access credentials.
3) SS_PRIV is no more, and with it goes the SO_PRIVSTATE setsockopt()
call. Protocols should use the process pointer they are now passed.
4) The PF_LOCAL and PF_ROUTE families have been updated to use the new
style, as has the `raw' skeleton family.
5) PF_LOCAL sockets now obey the process's umask when creating a socket
in the filesystem.
As a result, LINT is now broken. I'm hoping that some enterprising hacker
with a bit more time will either make the broken bits work (should be
easy for netipx) or dike them out.
cache lines. Removed the struct ip proto since only a couple of chars
were actually being used in it. Changed the order of compares in the
PCB hash lookup to take advantage of partial cache line fills (on PPro).
Discussed-with: wollman
set it in the first place, independent of whether sin->sin_port
is set.
The result is that diverted packets that are being forwarded
will be diverted once and only once on the way in (ip_input())
and again, once and only once on the way out (ip_output()) -
twice in total. ICMP packets that don't contain a port will
now also be diverted.
This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.
Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.
to TAILQs. Fix places which referenced these for no good reason
that I can see (the references remain, but were fixed to compile
again; they are still questionable).
using a sockaddr_dl.
Fix the other packet-information socket options (SO_TIMESTAMP, IP_RECVDSTADDR)
to work for multicast UDP and raw sockets as well. (They previously only
worked for unicast UDP).
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.
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.
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.
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.
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
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
a few new wrinkles for MTU discovery which tcp_output() had better
be prepared to handle. ip_output() is also modified to do something
helpful in this case, since it has already calculated the information
we need.
case, multicast options are not passed to ip_mforward().) The previous
version had a wrong test, thus causing RSVP mrouters to forward RSVP messages
in violation of the spec.
