BSD: Assume onlink flag on ifaces with only host addresses
The BSD kernel does not support the onlink flag and BIRD does not use
direct routes for next hop validation, instead depends on interface
address ranges. We would like to handle PtMP cases with only host
addresses configured, like:
BIRD would dismiss the route when receiving from the kernel, as the
next-hop 192.168.0.4 is not part of any interface subnet and onlink
flag is not kept by the BSD kernel.
The commit fixes this by assuming that for routes received from the
kernel, any next-hop is onlink on ifaces with only host addresses.
Job Snijders [Sat, 18 Dec 2021 15:35:28 +0000 (16:35 +0100)]
RPKI: Add contextual out-of-bound checks in RTR Prefix PDU handler
RFC 6810 and RFC 8210 specify that the "Max Length" value MUST NOT be
less than the Prefix Length element (underflow). On the other side,
overflow of the Max Length element also is possible, it being an 8-bit
unsigned integer allows for values larger than 32 or 128. This also
implicitly ensures there is no overflow of "Length" value.
When a PDU is received where the Max Length field is corrputed, the RTR
client (BIRD) should immediately terminate the session, flush all data
learned from that cache, and log an error for the operator.
Nest: Do not ignore secondary flag changes in ifa updates
Compare all IA_* flags that are set by sysdep iface code.
The old code ignores IA_SECONDARY flag when comparing whether iface
address updates from kernel changed anything. This is usually not an
issue as kernel removes all secondary addresses due to removal of the
primary one, but it breaks when sysctl 'promote_secondaries' is enabled
and kernel promotes secondary addresses to primary ones.
Maria Matejka [Fri, 26 Nov 2021 23:21:12 +0000 (00:21 +0100)]
Memory statistics split into Effective and Overhead
This feature is intended mostly for checking that BIRD's allocation
strategies don't consume much memory space. There are some cases where
withdrawing routes in a specific order lead to memory fragmentation and
this output should give the user at least a notion of how much memory is
actually used for data storage and how much memory is "just allocated"
or used for overhead.
Also raising the "system allocator overhead estimation" from 8 to 16
bytes; it is probably even more. I've found 16 as a local minimum in
best scenarios among reachable machines. I couldn't find any reasonable
method to estimate this value when BIRD starts up.
This commit also fixes the inaccurate computation of memory overhead for
slabs where the "system allocater overhead estimation" was improperly
added to the size of mmap-ed memory.
BIRD implements shutdown by reconfiguring to fake empty configuration.
Such fake config structure is created from the last running config and
shares some data, including symbol table. This allows access to (removed)
routing tables and causes crash when 'show route' command is used during
shutdown.
Clean up symbol table, table list and links to default tables, so removed
routing tables cannot be accessed during shutdown.
Pipes copy the original rte with old values, so they require rte to be
exported with stored tmpattrs. Other protocols access stored attributes
using eattr list, so they require rte to be exported with expanded
tmpattrs. This is temporary hack, we plan to remove whoe tmpattr mechanism.
In most cases of export there is no need to store back temporary
attributes to rte, as receivers (protocols) access eattr list anyway.
But pipe copies the original rte with old values, so we should store
tmpattrs also during export.
This implements support for MAC authentication in the Babel protocol, as
specified by RFC 8967. The implementation seeks to follow the RFC as close
as possible, with the only deliberate deviation being the addition of
support for all the HMAC algorithms already supported by Bird, as well as
the Blake2b variant of the Blake algorithm.
For description of applicability, assumptions and security properties,
see RFC 8967 sections 1.1 and 1.2.
In preparation for adding authentication checks, refactor the TLV
walking code so it can be reused for a separate pass of the packet
for authentication checks.
Nest: Allow specifying security keys as hex bytes as well as strings
Add support for specifying a password in hexadecimal format, The result
is the same whether a password is specified as a quoted string or a
hex-encoded byte string, this just makes it more convenient to input
high-entropy byte strings as MAC keys.
Import the blake2-kat.h header with test vector output from the blake
reference implementation, and add tests to mac_test.c to compare the
output of the Bird MAC algorithm implementations with that reference
output.
Since the reference implementation only has test vectors for the full
output size, there are no tests for the smaller-sized output variants.
The Babel MAC authentication RFC recommends implementing Blake2s as one of
the supported algorithms. In order to achieve do this, add the blake2b and
blake2s hash functions for MAC authentication. The hashing function
implementations are the reference implementations from blake2.net.
The Blake2 algorithms allow specifying an arbitrary output size, and the
Babel MAC spec says to implement Blake2s with 128-bit output. To satisfy
this, we add two different variants of each of the algorithms, one using
the default size (256 bits for Blake2s, 512 bits for Blake2b), and one
using half the default output size.
Add a wrapper function in sysdep to get random bytes, and required checks
in configure.ac to select how to do it. The configure script tries, in
order, getrandom(), getentropy() and reading from /dev/urandom.
BGP: Ensure that freed neighbor entry is not accessed
Routes from downed protocols stay in rtable (until next rtable prune
cycle ends) and may be even exported to another protocol. In BGP case,
source BGP protocol is examined, although dynamic parts (including
neighbor entries) are already freed. That may lead to crash under some
race conditions. Ensure that freed neighbor entry is not accessed to
avoid this issue.
Maria Matejka [Sun, 30 May 2021 11:07:16 +0000 (13:07 +0200)]
Babel: Seqno requests are properly decoupled from neighbors when the underlying interface disappears
When an interface disappears, all the neighbors are freed as well. Seqno
requests were anyway not decoupled from them, leading to strange
segfaults. This fix adds a proper seqno request list inside neighbors to
make sure that no pointer to neighbor is kept after free.
Jakub Ružička [Tue, 6 Apr 2021 16:13:16 +0000 (18:13 +0200)]
add apkg-powered upstream packaging for deb, rpm
Files in a single new distro/ dir allow apkg to build BIRD packages for
various distros directly from upstream sources as well as from upstream
archives.
Please see distro/README.md for more detail as well as apkg docs:
https://apkg.rtfd.io
I've used these files to build bird-2.0.8 on all currently supported
releases of following distros:
* Debian
* Ubuntu
* Fedora
* CentOS
* openSUSE
Please note that latest apkg with accumulated fixes for bird is needed:
https://gitlab.nic.cz/packaging/apkg/-/merge_requests/35
For numeric operators, comma is used for disjunction in expressions like
"10, 20, 30..40". But for bitmask operators, comma is used for
conjunction in a way that does not really make much sense. Use always
explicit logical operators (&& and ||) to connect bitmask operators.
Flowspec: Add code for conversion of flowspec parts to interval lists
Implement function flow_explicate_part() to convert flowspec numeric
expressions to a simple list of (disjoint, sorted) intervals. That could
be used in filters to build f_tree-based int-sets from them.
Babel: Log the reason when refusing to run on an interface
The babel protocol code checks whether iface supports multicast, and
whether it has a link-local address assigned. However, it doesn not give
any feedback if any of those checks fail, it just silently ignores the
interface. Fix this by explicitly logging when multicast check fails.
Based on patch from Toke Høiland-Jørgensen, thanks!
BSD: Propagate OS-level IFF_MULTICAST to internal IF_MULTICAST flag
The BSD code did not propagate the OS-level IFF_MULTICAST flag to the
Bird-internal IF_MULTICAST flag, which causes problems with Wireguard
interfaces on FreeBSD. The Linux sysdep code does propagate the flag
already, so just copy over the same check and flag update.
OSPF: Allow ifaces with host address as unnumbered PtP or PtMP ifaces
Ifaces with host address (/32) were forced to be stubby, but now they
can be used as PtP or PtMP. For these ifaces we need to:
- Do not force stub mode
- Accept packets from any IP as local
- Accept any configured neighbor as local
- Detect ifaces properly as unnumbered
- Use ONLINK flag for nexthops
BIRD uses hacked LinuxDocTools for building documentation, keeping some
parts locally and using remaining parts from system-installed one. This
setup breaks when LinuxDocTools makes some internal changes and is hard
to keep consistent.
Just include full LinuxDocTools code (both hacked and unmodified parts)
to avoid consistency issues. Note that we still need some binaries from
LinuxDocTools, so it still needs to be installed to build documentation.
Stefan Haller [Mon, 19 Apr 2021 13:06:42 +0000 (15:06 +0200)]
BSD: Fix invalid pointer derefence in logging code
For logging purposes a stack allocated net_addr struct was passed by
value as vararg (instead of the expected pointer). This resulted in
a segfault when the specific error condition got logged.
The flag makes sense just in external representation. It is reset during
BGP export, but keeping it internally broke MRT dumps for short attributes
that used it anyways.
Thanks to Simon Marsh for the bugreport and the patch.
Maria Matejka [Thu, 25 Mar 2021 19:51:23 +0000 (20:51 +0100)]
Dropping automatic tests for Debian 7 Wheezy.
Debian 7 Wheezy has been superseded by Debian 8 Jessie on Apr 25, 2015,
with LTS support ending on May 31, 2018.
Debian 7 Wheezy's default GCC doesn't fully support C11. It should
anyway still be possible to build BIRD for Debian 7 if you backport
a C11-capable compiler there.
Maria Matejka [Tue, 21 Jul 2020 22:09:15 +0000 (00:09 +0200)]
Slab: head now uses bitmask for used/free nodes info instead of lists
From now, there are no auxiliary pointers stored in the free slab nodes.
This led to strange debugging problems if use-after-free happened in
slab-allocated structures, especially if the structure's first member is
a next pointer.
This also reduces the memory needed by 1 pointer per allocated object.
OTOH, we now rely on pages being aligned to their size's multiple, which
is quite common anyway.
BGP statistics code was preliminary and i wanted to replace it by
separate 'show X stats' command. The patch hides the preliminary
output in 'show protocols all' so it is not part of the released
version.
OSPFv3: Update neighbor authentication state from Hello packets
In OSPFv3, only Hello and DBDes packets contain flags specifying whether
RFC 7166 authentication trailer is used. Other packets are processed
based on stored authentication state in neighbor structure. Update this
state with each received Hello to handle authentication change from
reconfigurations.
Thanks to Joakim Tjernlund and Kenth Eriksson for the bugreport.
In general, events are code handling some some condition, which is
scheduled when such condition happened and executed independently from
I/O loop. Work-events are a subgroup of events that are scheduled
repeatedly until some (often significant) work is done (e.g. feeding
routes to protocol). All scheduled events are executed during each
I/O loop iteration.
Separate work-events from regular events to a separate queue and
rate limit their execution to a fixed number per I/O loop iteration.
That should prevent excess latency when many work-events are
scheduled at one time (e.g. simultaneous reload of many BGP sessions).
Vincent Bernat [Wed, 10 Feb 2021 15:53:57 +0000 (16:53 +0100)]
BGP: Add support for BGP hostname capability
This is an implementation of draft-walton-bgp-hostname-capability-02.
It is implemented since quite some time for FRR and in datacenter, this
gives a nice output to avoid using IP addresses.
It is disabled by default. The hostname is retrieved from uname(2) and
can be overriden with "hostname" option. The domain name is never set
nor displayed.
Nest: Automatic channel reloads based on RPKI changes
If there are roa_check() calls in channel filters, then the channel
subscribes to ROA table notifications, which are sent when ROA tables
are updated (subject to settle time) and trigger channel reload or
refeed.
Flag signalling that MP-BGP mode should be used got reset after first
batch of routes, so remaining routes were processed without that, leading
to missing MP_REACH_NLRI attribute.
With net.ipv4.conf.XXX.ignore_routes_with_linkdown sysctl, a user can
ensure the kernel does not use a route whose target interface is down.
Such route is marked with a 'dead' / RTNH_F_DEAD flag.
Ignore these routes or multipath nexthops during scan.
Add fake MP_REACH_NLRI attribute with BGP next hop when encoding MRT
table dumps for IPv6 routes. That is necessary to encode next hop as
NEXT_HOP attribute is not used for MP-BGP.
Direct BFD sessions needs to be dispatched not only by IP addresses, but
also by interfaces, in order to avoid collisions between neighbors with
the same IPv6 link-local addresses.
Extend BFD session hash_ip key by interface index to handle that. Use 0
for multihop sessions.
RPKI: Remove port (and SSH username) from 'Cache server' output line
It was mixed-up if hostname is IPv6 address, and reporting separate
values (like port) on separate lines fits better into key-value style
of 'show protocols all' output. Also, the patch simplifies transport
identification formatting (although it is unused now).