networkd: add support to set route table
1. add support to configure the table id.
if id is less than 256 we can fit this in the header of route as
netlink property is a char. But in kernel this proepty is a
unsigned 32. Hence if greater that 256 add this as RTA_TABLE
attribute.
2. we are not setting the address family now. Now set this property.
This is essentially a revert of f38e0cce75 (which
removed the documentation of DUIDType on purpose). The description is heavily
updated for the new semantics.
This addresses #3127 § 4.
Let's move DUID configuration into the [DHCP] section, since it only makes
sense in a DHCP context, and should be close to the configuration of
ClientIdentifier= and suchlike.
This really shouldn't be a section of its own, we don't have any for any of our
other per-protocol specific identifiers...
Follow-up for #2890#2943
IPv6 protocol requires a minimum MTU of 1280 bytes on the interface.
This fixes#3046.
Introduce helper link_ipv6_enabled() to figure out whether IPV6 is enabled.
Introduce network_has_static_ipv6_addresses() to find out if any static
ipv6 address configured.
If IPv6 is not configured on any interface that is SLAAC, DHCPv6 and static
IPv6 addresses not configured, then IPv6 will be automatically disabled for that
interface, that is we write "1" to /proc/sys/net/ipv6/conf//disable_ipv6.
1. Replace strtol with unhexchar, verified with valid and invalid DUID strings.
2. Fix logging to use log_syntax instead of log_error.
3. On error reading DUID, ignore read and preserve previous state.
4. Fix man-pages to use markup, remove options not yet implemented.
5. Remove spurious header line in new files.
Enabling router advertisement may even trigger SLAAC or DHCPv6 to be used to configure
IPv6 addresses on the link. It may not be obvious that only in the SLAAC case will the
Token have an effect. Clarify this in the man page.
Addresses issue #863.
This way "networkctl status" becomes a bit more useful by default, as router
information is just visible, without any further configuration.
LLDP reception is fully passive and relatively low simple and low traffic,
hence this should be safe to enable by default.
This reworks the sd-lldp substantially, simplifying things on one hand, and
extending the logic a bit on the other.
Specifically:
- Besides the sd_lldp object only one other object is maintained now,
sd_lldp_neighbor. It's used both as storage for literal LLDP packets, and for
maintainging info about peers in the database. Separation between packet, TLV
and chassis data is not maintained anymore. This should be a major
simplification.
- The sd-lldp API has been extended so that a couple of per-neighbor fields may
be queried directly, without iterating through the object. Other fields that
may appear multiple times, OTOH have to be iterated through.
- The maximum number of entries in the neighbor database is now configurable
during runtime.
- The generation of callbacks from sd_lldp objects is more restricted:
callbacks are only invoked when actual data changed.
- The TTL information is now hooked with a timer event, so that removals from
the neighbor database due to TTLs now result in a callback event.
- Querying LLDP neighbor database will now return a strictly ordered array, to
guarantee stability.
- A "capabilities" mask may now be configured, that selects what type of LLDP
neighbor data is collected. This may be used to restrict collection of LLDP
info about routers instead of all neighbors. This is now exposed via
networkd's LLDP= setting.
- sd-lldp's API to serialize the collected data to text files has been removed.
Instead, there's now an API to extract the raw binary data from LLDP neighbor
objects, as well as one to convert this raw binary data back to an LLDP
neighbor object. networkd will save this raw binary data to /run now, and the
client side can simply parse the information.
- support for parsing the more exotic TLVs has been removed, since we are not
using that. Instead there are now APIs to extract the raw data from TLVs.
Given how easy it is to parse the TLVs clients should do so now directly
instead of relying on our APIs for that.
- A lot of the APIs that parse out LLDP strings have been simplified so that
they actually return strings, instead of char arrays with a length. To deal
with possibly dangerous characters the strings are escaped if needed.
- APIs to extract and format the chassis and port IDs as strings has been
added.
- lldp.h has been simplified a lot. The enums are anonymous now, since they
were never used as enums, but simply as constants. Most definitions we don't
actually use ourselves have eben removed.
This changes the UseDomains= setting of .network files to take an optional third value "route", in addition to the
boolean values. If set, the passed domain information is used for routing rules only, but not for the search path
logic.
Previously, .network files only knew a vaguely defined "Domains=" concept, for which the documentation declared it was
the "DNS domain" for the network connection, without specifying what that means.
With this the Domains setting is reworked, so that there are now "routing" domains and "search" domains. The former are
to be used by resolved to route DNS request to specific network interfaces, the latter is to be used for searching
single-label hostnames with (in addition to being used for routing). Both settings are configured in the "Domains="
setting. Normal domain names listed in it are now considered search domains (for compatibility with existing setups),
while those prefixed with "~" are considered routing domains only. To route all lookups to a specific interface the
routing domain "." may be used, referring to the root domain. An alternative syntax for this is the "*", as was already
implemented before using the "wildcard" domain concept.
This commit adds proper parsers for this new logic, and exposes this via the sd-network API. This information is not
used by resolved yet, this will be added in a later commit.
As it turns out the kernel does not support per-interface IPv6 packet
forwarding controls (unlike as it does for IPv4), but only supports a
global option (#1597). Also, the current per-interface management of the
setting isn't really useful, as you want it to propagate to at least one
more interface than the one you configure it on. This created much grief
(#1411, #1808).
Hence, let's roll this logic back and simplify this again, so that we
can expose the same behaviour on IPv4 and IPv6 and things start to work
automatically again for most folks: if a network with this setting set
is set up we propagate the setting into the global setting, but this is
strictly one-way: we never reset it again, and we do nothing for network
interfaces where this setting is not enabled.
Fixes: #1808, #1597.
The previous behavior:
When DHCPv6 was enabled, router discover was performed first, and then DHCPv6 was
enabled only if the relevant flags were passed in the Router Advertisement message.
Moreover, router discovery was performed even if AcceptRouterAdvertisements=false,
moreover, even if router advertisements were accepted (by the kernel) the flags
indicating that DHCPv6 should be performed were ignored.
New behavior:
If RouterAdvertisements are accepted, and either no routers are found, or an
advertisement is received indicating DHCPv6 should be performed, the DHCPv6
client is started. Moreover, the DHCP option now truly enables the DHCPv6
client regardless of router discovery (though it will probably not be
very useful to get a lease withotu any routes, this seems the more consistent
approach).
The recommended default setting should be to set DHCP=ipv4 and to leave
IPv6AcceptRouterAdvertisements unset.
The constraints we place on the pool is that it is a contiguous
sequence of addresses in the same subnet as the server address, not
including the subnet nor broadcast addresses, but possibly including
the server address itself. If the server address is included in the
pool it is (obviously) reserved and not handed out to clients.
This should clear up some confusion in
https://github.com/systemd/systemd/issues/717.
This basically copies the description from systemd.unit to this
man page. Masking can happen also in /run, so strike the part
about /etc, and also add the magic work "mask".
Justification is similar to BPDUGuard rename. "Positive" values
are easier. This is a rather uncommon option, so using a slightly
longer name should not be a problem, and may in fact may make it
easier to guess what the option does without reading the
documentation.
Looking at the kernel commit, "on" seems to be the default value:
commit 867a59436fc35593ae0e0efcd56cc6d2f8506586
Author: Vlad Yasevich <vyasevic@redhat.com>
Date: Wed Jun 5 10:08:01 2013 -0400
bridge: Add a flag to control unicast packet flood.
Add a flag to control flood of unicast traffic. By default, flood is
on and the bridge will flood unicast traffic if it doesn't know
the destination. When the flag is turned off, unicast traffic
without an FDB will not be forwarded to the specified port.
... and it seems to be the reasonable thing to do by default.
