Currently we have tables identified by their names in userland
with internal kernel-assigned indices. This works the following way:
When userland wishes to communicate with kernel to add or change rule(s),
it makes indexed sorted array of table names
(internally ipfw_obj_ntlv entries), and refer to indices in that
array in rule manipulation.
Prior to committing new rule to the ruleset kernel
a) finds all referenced tables, bump their refcounts and change
values inside the opcodes to be real kernel indices
b) auto-creates all referenced but not existing tables and then
do a) for them.
Kernel does almost the same when exporting rules to userland:
prepares array of used tables in all rules in range, and
prepends it before the actual ruleset retaining actual in-kernel
indexes for that.
There is also special translation layer for legacy clients which is
able to provide 'real' indices for table names (basically doing atoi()).
While it is arguable that every subsystem really needs names instead of
numbers, there are several things that should be noted:
1) every non-singleton subsystem needs to store its runtime state
somewhere inside ipfw chain (and be able to get it fast)
2) we can't assume object numbers provided by humans will be dense.
Existing nat implementation (O(n) access and LIST inside chain) is a
good example.
Hence the following:
* Convert table-centric rewrite code to be more generic, callback-based
* Move most of the code from ip_fw_table.c to ip_fw_sockopt.c
* Provide abstract API to permit subsystems convert their objects
between userland string identifier and in-kernel index.
(See struct opcode_obj_rewrite) for more details
* Create another per-chain index (in next commit) shared among all subsystems
* Convert current NAT44 implementation to use new API, O(1) lookups,
shared index and names instead of numbers (in next commit).
Sponsored by: Yandex LLC
discontinued by its initial authors. In FreeBSD the code was already
slightly edited during the pf(4) SMP project. It is about to be edited
more in the projects/ifnet. Moving out of contrib also allows to remove
several hacks to the make glue.
Reviewed by: net@
If the direction is not PF_OUT we can never be forwarding. Some input packets
have rcvif != ifp (looped back packets), which lead us to ip6_forward() inbound
packets, causing panics.
Equally, we need to ensure that packets were really received and not locally
generated before trying to ip6_forward() them.
Differential Revision: https://reviews.freebsd.org/D2286
Approved by: gnn(mentor)
set past this point in the code. The packet should be dropped and
not massaged as it is here.
Differential Revision: https://reviews.freebsd.org/D2266
Submitted by: eri
Sponsored by: Rubicon Communications (Netgate)
In cases where we scrub (fragment reassemble) on both input and output
we risk ending up in infinite loops when forwarding packets.
Fragmented packets come in and get collected until we can defragment. At
that point the defragmented packet is handed back to the ip stack (at
the pfil point in ip6_input(). Normal processing continues.
Eventually we figure out that the packet has to be forwarded and we end
up at the pfil hook in ip6_forward(). After doing the inspection on the
defragmented packet we see that the packet has been defragmented and
because we're forwarding we have to refragment it.
In pf_refragment6() we split the packet up again and then ip6_forward()
the individual fragments. Those fragments hit the pfil hook on the way
out, so they're collected until we can reconstruct the full packet, at
which point we're right back where we left off and things continue until
we run out of stack.
Break that loop by marking the fragments generated by pf_refragment6()
as M_SKIP_FIREWALL. There's no point in processing those packets in the
firewall anyway. We've already filtered on the full packet.
Differential Revision: https://reviews.freebsd.org/D2197
Reviewed by: glebius, gnn
Approved by: gnn (mentor)
where we want to create a new IP datagram.
o Add support for RFC6864, which allows to set IP ID for atomic IP
datagrams to any value, to improve performance. The behaviour is
controlled by net.inet.ip.rfc6864 sysctl knob, which is enabled by
default.
o In case if we generate IP ID, use counter(9) to improve performance.
o Gather all code related to IP ID into ip_id.c.
Differential Revision: https://reviews.freebsd.org/D2177
Reviewed by: adrian, cy, rpaulo
Tested by: Emeric POUPON <emeric.poupon stormshield.eu>
Sponsored by: Netflix
Sponsored by: Nginx, Inc.
Relnotes: yes
On Ethernet packets have a minimal length, so very short packets get padding
appended to them. This padding is not stripped off in ip6_input() (due to
support for IPv6 Jumbograms, RFC2675).
That means PF needs to be careful when reassembling fragmented packets to not
include the padding in the reassembled packet.
While here also remove the 'Magic from ip_input.' bits. Splitting up and
re-joining an mbuf chain here doesn't make any sense.
Differential Revision: https://reviews.freebsd.org/D2189
Approved by: gnn (mentor)
When forwarding fragmented IPv6 packets and filtering with PF we
reassemble and refragment. That means we generate new fragment headers
and a new fragment ID.
We already save the fragment IDs so we can do the reassembly so it's
straightforward to apply the incoming fragment ID on the refragmented
packets.
Differential Revision: https://reviews.freebsd.org/D2188
Approved by: gnn (mentor)
to obtain IPv4 next hop address in tablearg case.
Add `fwd tablearg' support for IPv6. ipfw(8) uses INADDR_ANY as next hop
address in O_FORWARD_IP opcode for specifying tablearg case. For IPv6 we
still use this opcode, but when packet identified as IPv6 packet, we
obtain next hop address from dedicated field nh6 in struct table_value.
Replace hopstore field in struct ip_fw_args with anonymous union and add
hopstore6 field. Use this field to copy tablearg value for IPv6.
Replace spare1 field in struct table_value with zoneid. Use it to keep
scope zone id for link-local IPv6 addresses. Since spare1 was used
internally, replace spare0 array with two variables spare0 and spare1.
Use getaddrinfo(3)/getnameinfo(3) functions for parsing and formatting
IPv6 addresses in table_value. Use zoneid field in struct table_value
to store sin6_scope_id value.
Since the kernel still uses embedded scope zone id to represent
link-local addresses, convert next_hop6 address into this form before
return from pfil processing. This also fixes in6_localip() check
for link-local addresses.
Differential Revision: https://reviews.freebsd.org/D2015
Obtained from: Yandex LLC
Sponsored by: Yandex LLC
size as they arrived in. This allows the sender to determine the optimal
fragment size by Path MTU Discovery.
Roughly based on the OpenBSD work by Alexander Bluhm.
Submitted by: Kristof Provost
Differential Revision: D1767
That partially fixes IPv6 fragment handling. Thanks to Kristof for
working on that.
Submitted by: Kristof Provost
Tested by: peter
Differential Revision: D1765
very questionable, since it makes vimages more dependent on each other. But
the reason for the backout is that it screwed up shutting down the pf purge
threads, and now kernel immedially panics on pf module unload. Although module
unloading isn't an advertised feature of pf, it is very important for
development process.
I'd like to not backout r276746, since in general it is good. But since it
has introduced numerous build breakages, that later were addressed in
r276841, r276756, r276747, I need to back it out as well. Better replay it
in clean fashion from scratch.
Split functions that initialize various pf parts into their
vimage parts and global parts.
Since global parts appeared to be only mutex initializations, just
abandon them and use MTX_SYSINIT() instead.
Kill my incorrect VNET_FOREACH() iterator and instead use correct
approach with VNET_SYSINIT().
PR: 194515
Differential Revision: D1309
Submitted by: glebius, Nikos Vassiliadis <nvass@gmx.com>
Reviewed by: trociny, zec, gnn
- Wrong integer type was specified.
- Wrong or missing "access" specifier. The "access" specifier
sometimes included the SYSCTL type, which it should not, except for
procedural SYSCTL nodes.
- Logical OR where binary OR was expected.
- Properly assert the "access" argument passed to all SYSCTL macros,
using the CTASSERT macro. This applies to both static- and dynamically
created SYSCTLs.
- Properly assert the the data type for both static and dynamic
SYSCTLs. In the case of static SYSCTLs we only assert that the data
pointed to by the SYSCTL data pointer has the correct size, hence
there is no easy way to assert types in the C language outside a
C-function.
- Rewrote some code which doesn't pass a constant "access" specifier
when creating dynamic SYSCTL nodes, which is now a requirement.
- Updated "EXAMPLES" section in SYSCTL manual page.
MFC after: 3 days
Sponsored by: Mellanox Technologies
Main user-visible changes are related to tables:
* Tables are now identified by names, not numbers.
There can be up to 65k tables with up to 63-byte long names.
* Tables are now set-aware (default off), so you can switch/move
them atomically with rules.
* More functionality is supported (swap, lock, limits, user-level lookup,
batched add/del) by generic table code.
* New table types are added (flow) so you can match multiple packet fields at once.
* Ability to add different type of lookup algorithms for particular
table type has been added.
* New table algorithms are added (cidr:hash, iface:array, number:array and
flow:hash) to make certain types of lookup more effective.
* Table value are now capable of holding multiple data fields for
different tablearg users
Performance changes:
* Main ipfw lock was converted to rmlock
* Rule counters were separated from rule itself and made per-cpu.
* Radix table entries fits into 128 bytes
* struct ip_fw is now more compact so more rules will fit into 64 bytes
* interface tables uses array of existing ifindexes for faster match
ABI changes:
All functionality supported by old ipfw(8) remains functional.
Old & new binaries can work together with the following restrictions:
* Tables named other than ^\d+$ are shown as table(65535) in
ruleset in old binaries
Internal changes:.
Changing table ids to numbers resulted in format modification for
most sockopt codes. Old sopt format was compact, but very hard to
extend (no versioning, inability to add more opcodes), so
* All relevant opcodes were converted to TLV-based versioned IP_FW3-based codes.
* The remaining opcodes were also converted to be able to eliminate
all older opcodes at once
* All IP_FW3 handlers uses special API instead of calling sooptcopy*
directly to ease adding another communication methods
* struct ip_fw is now different for kernel and userland
* tablearg value has been changed to 0 to ease future extensions
* table "values" are now indexes in special value array which
holds extended data for given index
* Batched add/delete has been added to tables code
* Most changes has been done to permit batched rule addition.
* interface tracking API has been added (started on demand)
to permit effective interface tables operations
* O(1) skipto cache, currently turned off by default at
compile-time (eats 512K).
* Several steps has been made towards making libipfw:
* most of new functions were separated into "parse/prepare/show
and actuall-do-stuff" pieces (already merged).
* there are separate functions for parsing text string into "struct ip_fw"
and printing "struct ip_fw" to supplied buffer (already merged).
* Probably some more less significant/forgotten features
MFC after: 1 month
Sponsored by: Yandex LLC
