Commit graph

22 commits

Author SHA1 Message Date
Toke Høiland-Jørgensen
69d10132a6 Babel: Refactor TLV parsing code for easier reuse
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.
2021-06-06 16:28:18 +02:00
Toke Høiland-Jørgensen
db2d29073a lib/slab: introduce sl_allocz() function and use it in Babel
The babel protocol code was initialising objects returned from the slab
allocator by assigning to each of the struct members individually, but
wasn't touching the NODE member while doing so. This leads to warnings on
debug builds since commit:

baac700906 ("List expensive check.")

To fix this, introduce an sl_allocz() variant of the slab allocator which
will zero out the memory before returning it, and switch all the babel call
sites to use this version. The overhead for doing this should be negligible
for small objects, and in the case of babel, the largest object being
allocated was being zeroed anyway, so we can drop the memset in
babel_read_tlv().
2020-11-24 02:36:31 +01:00
Ondrej Zajicek (work)
caa9d03d65 Babel: Fix handling of missing IPv4 next hops
In case of missing IPv4 next hop, we should skip such routes
on transmit and ignore such routes on receive.

Thanks to Julian Schuh for the bugreport and Toke Hoiland-Jorgensen
for the original patch.
2018-06-13 15:22:29 +02:00
Ondrej Zajicek (work)
185a0a51f8 Babel: Add source-specific routing support
This patch adds support for source-specific routing to the Babel protocol.
It changes the protocol to support both NET_IP6 and NET_IP6_SADR channels
for IPv6 addresses. If only a NET_IP6 channel is configured,
source-specific updates are ignored. Otherwise, non-source-specific
routes are simply treated as source-specific routes with SADR prefix 0.

Thanks to Toke Hoiland-Jorgensen for the original patch.
Minor changes by Ondrej Santiago Zajicek.
2018-02-13 16:40:14 +01:00
Ondrej Zajicek (work)
830ba75e6d Merge commit '1e8721e2aeccfbc3f533e8b8abc07582cee77e9a' into int-new 2017-12-07 21:54:47 +01:00
Ondrej Zajicek (work)
46434a3cad Merge commit '7b2c5f3d2826e3175bf31b1c36056c9efc587a2b' into int-new 2017-12-07 18:35:46 +01:00
Ondrej Zajicek (work)
3b3b0910ff Babel: More changes and bugfixes
Several changes and bugfixes in Babel, namely:

- Exported route parameters stored directly in route table entry
- Exported non-babel routes no longer stored in per-entry route list
- Route update, selection and retraction simplified and fixed
- Route feasibility is evalualated per update and stored with route
- Unreachable route handling fixed, based on hold interval
- Added 'show babel routes' command

Overall, it fixes some issues with proper propagation of triggered
updates, making Babel convergence after topology change almost
instant.
2017-12-07 13:53:42 +01:00
Ondrej Zajicek (work)
672fb78e12 Babel: Fix handling of IPv4 retractions
Babel TLV parsing code rejected IPv4 retractions without next-hop,
although next-hop is needed just for regular updates.
2017-12-07 13:53:42 +01:00
Ondrej Zajicek (work)
8b58f565e4 Babel: Update to new timers 2017-12-07 13:53:42 +01:00
Ondrej Zajicek (work)
153f02da3b Nest: Maintain separate IPv4, IPv6 and LLv6 preferred addresses
Also redesign preferred address selection and update protocols to use
appropriate preferred address.

Based on a previous work by Jan Maria Matejka.
2017-12-07 13:06:01 +01:00
Ondrej Zajicek (work)
1e8721e2ae Babel: Parse flags in Hello TLV
RFC6126bis introduces a flags field for the Hello TLV, and adds a unicast flag
that is used to signify that a hello was sent as unicast. This adds parsing of
the flags field and ignores such unicast hellos, which preserves compatibility
until we can add a proper implementation of the unicast hello mechanism.

Thanks to Toke Hoiland-Jorgensen for the patch.
2017-11-28 19:33:33 +01:00
Ondrej Zajicek (work)
cd1d99611e BGP: Shutdown communication (RFC 8203)
The patch implements BGP Administrative Shutdown Communication (RFC 8203)
allowing BGP operators to pass messages related to BGP session
administrative shutdown/restart. It handles both transmit and receive of
shutdown messages. Messages are logged and may be displayed by show
protocol all command.

Thanks to Job Snijders for the basic patch.
2017-09-19 19:57:52 +02:00
Ondrej Zajicek (work)
943478b00f Basic VRF support
Add basic VRF (virtual routing and forwarding) support. Protocols can be
associated with VRFs, such protocols will be restricted to interfaces
assigned to the VRF (as reported by Linux kernel) and will use sockets
bound to the VRF. E.g., different multihop BGP instances can use diffent
kernel routing tables to handle BGP TCP connections.

The VRF support is preliminary, currently there are several limitations:

- Recent Linux kernels (4.11) do not handle correctly sockets bound
to interaces that are part of VRF, so most protocols other than multihop
BGP do not work. This will be fixed by future kernel versions.

- Neighbor cache ignores VRFs. Breaks config with the same prefix on
local interfaces in different VRFs. Not much problem as single hop
protocols do not work anyways.

- Olock code ignores VRFs. Breaks config with multiple BGP peers with the
same IP address in different VRFs.

- Incoming BGP connections are not dispatched according to VRFs.
Breaks config with multiple BGP peers with the same IP address in
different VRFs. Perhaps we would need some kernel API to read VRF of
incoming connection? Or probably use multiple listening sockets in
int-new branch.

- We should handle master VRF interface up/down events and perhaps
disable associated protocols when VRF goes down. Or at least disable
associated interfaces.

- Also we should check if the master iface is really VRF iface and
not some other kind of master iface.

- BFD session request dispatch should be aware of VRFs.

- Perhaps kernel protocol should read default kernel table ID from VRF
iface so it is not necessary to configure it.

- Perhaps we should have per-VRF default table.
2017-09-06 17:38:48 +02:00
Ondrej Zajicek (work)
5220cb63e3 Babel: Fix pointer arithmetic in subtlv parsing
The subtlv parsing code was doing byte-based arithmetic with non-void pointers,
causing it to read beyond the end of the packet.

Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>
2017-06-14 12:34:43 +02:00
Ondrej Zajicek (work)
145ebfa1df Babel: Parse sub-TLVs and skip TLVs with mandatory sub-TLV
RFC6126bis formally introduces sub-TLVs to the Babel protocol, including
mandatory sub-TLVs. This adds support for parsing sub-TLVs to the Babel
protocol and skips TLVs that contain mandatory sub-TLVs, as per the spec.

For details, see section 4.4 of
https://tools.ietf.org/html/draft-ietf-babel-rfc6126bis-02

Thanks to Toke Høiland-Jørgensen <toke@toke.dk> for the patch.
2017-06-09 14:33:06 +02:00
Ondrej Zajicek (work)
b3c6273efa Babel: Implement IPv6 prefix compression on outgoing updates
Previously, the Babel protocol would never use prefix compression on outgoing
updates (but would parse it on incoming ones). This adds compression of IPv6
addresses of outgoing updates.

The compression only works to the extent that the FIB is walked in lexicographic
order; i.e. a prefix is only compressed if it shares bytes with the previous
prefix in the same packet.

Thanks to Toke Høiland-Jørgensen <toke@toke.dk> for the patch.
2017-06-09 13:00:20 +02:00
Ondrej Zajicek (work)
4324025f98 Babel: Add support for dual-stack IPv4/IPv6 operation
This adds support for dual-stack v4/v6 operation to the Babel protocol.
Routing messages will be exchanged over IPv6, but IPv4 routes can be
carried in the messages being exchanged. This matches how the reference
Babel implementation (babeld) works.

The nexthop address for v4 can be configured per interface, and will
default to the first available IPv4 address on the given interface. For
symmetry, a configuration option to configure the IPv6 nexthop address
is also added.

Thanks to Toke Høiland-Jørgensen <toke@toke.dk> for the patch.
2017-06-08 12:18:16 +02:00
Ondrej Zajicek (work)
5e8df049fb Babel: Update to integrated branch 2016-12-10 00:44:13 +01:00
Jan Moskyto Matejka
3e236955c9 Build: switch on -Wextra, get rid of most of the warnings
There are several unresolved -Wmissing-field-initializers on older
versions of GCC than 5.1, all of them false positive.
2016-11-01 14:52:54 +01:00
Ondrej Zajicek (work)
5d6ca22085 Babel: Send wildcard retractions on shutdown and startup
This makes BIRD send a wildcard retraction on all interfaces before
shutting down and right after starting up. This helps ensure that
neighbours will discard the announced routes as soon as possible,
rather than only after the normal timeout procedures.

Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>
2016-07-19 14:23:41 +02:00
Ondrej Zajicek (work)
ecae2f43f3 Babel: Rework handling of retractions
An update with wildcard AE and infinite metric should be treated as a
global retraction of all prefixes announced by that neighbour, per
section 4.4.9 of the RFC. In addition, router ID and seqno in retraction
updates should be ignored. This reworks the handling of retractions and
adjusts the parser to handle all this correctly.

Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>
2016-07-19 13:33:02 +02:00
Ondrej Zajicek (work)
937e75d8f1 Add the Babel routing protocol (RFC 6126)
This patch implements the IPv6 subset of the Babel routing protocol.
Based on the patch from Toke Hoiland-Jorgensen, with some heavy
modifications and bugfixes.

Thanks to Toke Hoiland-Jorgensen for the original patch.
2016-04-28 18:01:40 +02:00