The KPI have been reviewed and cleansed of features that were planned
back 20 years ago and never implemented. The pfil(9) internals have
been made opaque to protocols with only returned types and function
declarations exposed. The KPI is made more strict, but at the same time
more extensible, as kernel uses same command structures that userland
ioctl uses.
In nutshell [KA]PI is about declaring filtering points, declaring
filters and linking and unlinking them together.
New [KA]PI makes it possible to reconfigure pfil(9) configuration:
change order of hooks, rehook filter from one filtering point to a
different one, disconnect a hook on output leaving it on input only,
prepend/append a filter to existing list of filters.
Now it possible for a single packet filter to provide multiple rulesets
that may be linked to different points. Think of per-interface ACLs in
Cisco or Juniper. None of existing packet filters yet support that,
however limited usage is already possible, e.g. default ruleset can
be moved to single interface, as soon as interface would pride their
filtering points.
Another future feature is possiblity to create pfil heads, that provide
not an mbuf pointer but just a memory pointer with length. That would
allow filtering at very early stages of a packet lifecycle, e.g. when
packet has just been received by a NIC and no mbuf was yet allocated.
Differential Revision: https://reviews.freebsd.org/D18951
Forwarded packets passed through PFIL_OUT, which made it difficult for
firewalls to figure out if they were forwarding or producing packets. This in
turn is an issue for pf for IPv6 fragment handling: it needs to call
ip6_output() or ip6_forward() to handle the fragments. Figuring out which was
difficult (and until now, incorrect).
Having pfil distinguish the two removes an ugly piece of code from pf.
Introduce a new variant of the netpfil callbacks with a flags variable, which
has PFIL_FWD set for forwarded packets. This allows pf to reliably work out if
a packet is forwarded.
Reviewed by: ae, kevans
Differential Revision: https://reviews.freebsd.org/D13715
Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.
The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.
No functional change intended.
New flag 0x4 can be configured in net.enc.[in|out].ipsec_bpf_mask.
When it is set, if_enc(4) additionally captures a packet via BPF after
invoking pfil hook. This may be useful for debugging.
MFC after: 2 weeks
Sponsored by: Yandex LLC
Differential Revision: https://reviews.freebsd.org/D11804
from enc_hhook().
This should solve the problem when pf is used with if_enc(4) interface,
and outbound packet with existing PCB checked by pf, and this leads to
deadlock due to pf does its own PCB lookup and tries to take rlock when
wlock is already held.
Now we pass PCB pointer if it is known to the pfil hook, this helps to
avoid extra PCB lookup and thus rlock acquiring is not needed.
For inbound packets it is safe to pass NULL, because we do not held any
PCB locks yet.
PR: 220217
MFC after: 3 weeks
Sponsored by: Yandex LLC
than removing the network interfaces first. This change is rather larger
and convoluted as the ordering requirements cannot be separated.
Move the pfil(9) framework to SI_SUB_PROTO_PFIL, move Firewalls and
related modules to their own SI_SUB_PROTO_FIREWALL.
Move initialization of "physical" interfaces to SI_SUB_DRIVERS,
move virtual (cloned) interfaces to SI_SUB_PSEUDO.
Move Multicast to SI_SUB_PROTO_MC.
Re-work parts of multicast initialisation and teardown, not taking the
huge amount of memory into account if used as a module yet.
For interface teardown we try to do as many of them as we can on
SI_SUB_INIT_IF, but for some this makes no sense, e.g., when tunnelling
over a higher layer protocol such as IP. In that case the interface
has to go along (or before) the higher layer protocol is shutdown.
Kernel hhooks need to go last on teardown as they may be used at various
higher layers and we cannot remove them before we cleaned up the higher
layers.
For interface teardown there are multiple paths:
(a) a cloned interface is destroyed (inside a VIMAGE or in the base system),
(b) any interface is moved from a virtual network stack to a different
network stack ("vmove"), or (c) a virtual network stack is being shut down.
All code paths go through if_detach_internal() where we, depending on the
vmove flag or the vnet state, make a decision on how much to shut down;
in case we are destroying a VNET the individual protocol layers will
cleanup their own parts thus we cannot do so again for each interface as
we end up with, e.g., double-frees, destroying locks twice or acquiring
already destroyed locks.
When calling into protocol cleanups we equally have to tell them
whether they need to detach upper layer protocols ("ulp") or not
(e.g., in6_ifdetach()).
Provide or enahnce helper functions to do proper cleanup at a protocol
rather than at an interface level.
Approved by: re (hrs)
Obtained from: projects/vnet
Reviewed by: gnn, jhb
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D6747
Use hhook(9) framework to achieve ability of loading and unloading
if_enc(4) kernel module. INET and INET6 code on initialization registers
two helper hooks points in the kernel. if_enc(4) module uses these helper
hook points and registers its hooks. IPSEC code uses these hhook points
to call helper hooks implemented in if_enc(4).
to this event, adding if_var.h to files that do need it. Also, include
all includes that now are included due to implicit pollution via if_var.h
Sponsored by: Netflix
Sponsored by: Nginx, Inc.
now use function calls:
if_clone_simple()
if_clone_advanced()
to initialize a cloner, instead of macros that initialize if_clone
structure.
Discussed with: brooks, bz, 1 year ago
- All packets in NETISR_IP queue are in net byte order.
- ip_input() is entered in net byte order and converts packet
to host byte order right _after_ processing pfil(9) hooks.
- ip_output() is entered in host byte order and converts packet
to net byte order right _before_ processing pfil(9) hooks.
- ip_fragment() accepts and emits packet in net byte order.
- ip_forward(), ip_mloopback() use host byte order (untouched actually).
- ip_fastforward() no longer modifies packet at all (except ip_ttl).
- Swapping of byte order there and back removed from the following modules:
pf(4), ipfw(4), enc(4), if_bridge(4).
- Swapping of byte order added to ipfilter(4), based on __FreeBSD_version
- __FreeBSD_version bumped.
- pfil(9) manual page updated.
Reviewed by: ray, luigi, eri, melifaro
Tested by: glebius (LE), ray (BE)
the CAM "enc" peripheral (part of ses(4)). Previously the two modules
used the same name, so only one was included in a linked kernel causing
enc0 to not be created if you added IPSEC to GENERIC. The new module
name follows the pattern of other network interfaces (e.g. "if_loop").
MFC after: 1 week
The SYSCTL_NODE macro defines a list that stores all child-elements of
that node. If there's no SYSCTL_DECL macro anywhere else, there's no
reason why it shouldn't be static.
adding appropriate #ifdefs. For module builds the framework needs
adjustments for at least carp.
Reviewed by: gnn
Sponsored by: The FreeBSD Foundation
Sponsored by: iXsystems
MFC after: 4 days
reading. (This was already done for writing to a sysctl). This
requires all SYSCTL setups to specify a type. Most of them are now
checked at compile-time.
Remove SYSCTL_*X* sysctl additions as the print being in hex should be
controlled by the -x flag to sysctl(8).
Succested by: bde
virtualizing the pfil hooks.
For consistency add the V_ to virtualize the pfil hooks in here as well.
MFC after: 55 days
X-MFC after: julian MFCed r197952.
vnet.h, we now use jails (rather than vimages) as the abstraction
for virtualization management, and what remained was specific to
virtual network stacks. Minor cleanups are done in the process,
and comments updated to reflect these changes.
Reviewed by: bz
Approved by: re (vimage blanket)
(DPCPU), as suggested by Peter Wemm, and implement a new per-virtual
network stack memory allocator. Modify vnet to use the allocator
instead of monolithic global container structures (vinet, ...). This
change solves many binary compatibility problems associated with
VIMAGE, and restores ELF symbols for virtualized global variables.
Each virtualized global variable exists as a "reference copy", and also
once per virtual network stack. Virtualized global variables are
tagged at compile-time, placing the in a special linker set, which is
loaded into a contiguous region of kernel memory. Virtualized global
variables in the base kernel are linked as normal, but those in modules
are copied and relocated to a reserved portion of the kernel's vnet
region with the help of a the kernel linker.
Virtualized global variables exist in per-vnet memory set up when the
network stack instance is created, and are initialized statically from
the reference copy. Run-time access occurs via an accessor macro, which
converts from the current vnet and requested symbol to a per-vnet
address. When "options VIMAGE" is not compiled into the kernel, normal
global ELF symbols will be used instead and indirection is avoided.
This change restores static initialization for network stack global
variables, restores support for non-global symbols and types, eliminates
the need for many subsystem constructors, eliminates large per-subsystem
structures that caused many binary compatibility issues both for
monitoring applications (netstat) and kernel modules, removes the
per-function INIT_VNET_*() macros throughout the stack, eliminates the
need for vnet_symmap ksym(2) munging, and eliminates duplicate
definitions of virtualized globals under VIMAGE_GLOBALS.
Bump __FreeBSD_version and update UPDATING.
Portions submitted by: bz
Reviewed by: bz, zec
Discussed with: gnn, jamie, jeff, jhb, julian, sam
Suggested by: peter
Approved by: re (kensmith)
missing it.
Remove the "hidden" kernel only include of vimage.h from ip_var.h added
with the very first Vimage commit r181803 to avoid further kernel poisoning.
(dummynet), ipsec_filter() would return the empty error code and the ipsec code
would continue to forward/deference the null mbuf.
Found by: m0n0wall
Reviewed by: bz
MFC after: 3 days
bpf will see inner and outer headers or just inner or outer
headers for incoming and outgoing IPsec packets.
This is useful in bpf to not have over long lines for debugging
or selcting packets based on the inner headers.
It also properly defines the behavior of what the firewalls see.
Last but not least it gives you if_enc(4) for IPv6 as well.
[ As some auxiliary state was not available in the later
input path we save it in the tdbi. That way tcpdump can give a
consistent view of either of (authentic,confidential) for both
before and after states. ]
Discussed with: thompsa (2007-04-25, basic idea of unifying paths)
Reviewed by: thompsa, gnn
semantics.
- Stop testing bpf pointers for NULL. In some cases use
bpf_peers_present() and then call the function directly inside the
conditional block instead of the macro.
- For places where the entire conditional block is the macro, remove the
test and make the macro unconditional.
- Use BPF_MTAP() in if_pfsync on FreeBSD instead of an expanded version of
the old semantics.
Reviewed by: csjp (older version)
tested and then set. [1]
Reorganise things to eliminate this, we now ensure that enc0 can not be
destroyed which as the benefit of no longer needing to lock in
ipsec_filter and ipsec_bpf. The cloner will create one interface during the
init so we can guarantee that encif will be valid before any SPD entries are
added to ipsec.
Spotted by: glebius [1]
encryption. There are two functions, a bpf tap which has a basic header with
the SPI number which our current tcpdump knows how to display, and handoff to
pfil(9) for packet filtering.
Obtained from: OpenBSD
Based on: kern/94829
No objections: arch, net
MFC after: 1 month
