Whenever a Router Advertisement is received, dhcp6_configure() will be
called. A Router Advertisment can also instruct DHCPv6 to start acquiring
IPv6 addresses in manged mode, if it previously was handling only other
information. As an Router Advertisment is also received after the DHCPv6
client has resumed from a suspend, fix the function not to assume DHCPv6
is currently running, but instead try to restart it. Handle
sd_dhcp6_start() returning -EALREADY indicating that the DHCPv6 client was
already running.
Collect all client unrefs in one place to unclutter the error handling.
Fixes https://github.com/systemd/systemd/issues/963
This changes log_unit_info() (and friends) to take a real Unit* object
insted of just a unit name as parameter. The call will now prefix all
logged messages with the unit name, thus allowing the unit name to be
dropped from the various passed romat strings, simplifying invocations
drastically, and unifying log output across messages. Also, UNIT= vs.
USER_UNIT= is now derived from the Manager object attached to the Unit
object, instead of getpid(). This has the benefit of correcting the
field for --test runs.
Also contains a couple of other logging improvements:
- Drops a couple of strerror() invocations in favour of using %m.
- Not only .mount units now warn if a symlinks exist for the mount
point already, .automount units do that too, now.
- A few invocations of log_struct() that didn't actually pass any
additional structured data have been replaced by simpler invocations
of log_unit_info() and friends.
- For structured data a new LOG_UNIT_MESSAGE() macro has been added,
that works like LOG_MESSAGE() but prefixes the message with the unit
name. Similar, there's now LOG_LINK_MESSAGE() and
LOG_NETDEV_MESSAGE().
- For structured data new LOG_UNIT_ID(), LOG_LINK_INTERFACE(),
LOG_NETDEV_INTERFACE() macros have been added that generate the
necessary per object fields. The old log_unit_struct() call has been
removed in favour of these new macros used in raw log_struct()
invocations. In addition to removing one more function call this
allows generated structured log messages that contain two object
fields, as necessary for example for network interfaces that are
joined into another network interface, and whose messages shall be
indexed by both.
- The LOG_ERRNO() macro has been removed, in favour of
log_struct_errno(). The latter has the benefit of ensuring that %m in
format strings is properly resolved to the specified error number.
- A number of logging messages have been converted to use
log_unit_info() instead of log_info()
- The client code in sysv-generator no longer #includes core code from
src/core/.
- log_unit_full_errno() has been removed, log_unit_full() instead takes
an errno now, too.
- log_unit_info(), log_link_info(), log_netdev_info() and friends, now
avoid double evaluation of their parameters
When setting IPv6 addresses acquired by DHCPv6, systemd-networkd sets
the IFA_F_NOPREFIXROUTE flag in the IFA_FLAGS netlink attribute. As
the flag and the attribute are present starting with Linux 3.14, older
kernels will need systemd-network to manage prefix route expiry.
By default, DHCPv6 addresses are first assigned setting the
IFA_F_NOPREFIXROUTE flag in the IFA_FLAGS netlink attribute. Should
the address assignment fail, the same assignment is tried without
the IFA_FLAGS attribute. Should also the second attempt fail, an error
is printed and address assignment ends with failure. As successful use
of the IFA_FLAGS netlink attribute is recorded in the Link structure,
the DHCPv6 code will know if the kernel or systemd-network fallback
code handles expiring prefixes.
The prefix expiration and IPv6 address updating fallback code is
resurrected from the parts deleted with commit
47d45d3cde.
This patch can be removed once the minimum kernel requirements are
greater than or equal to 3.14.
Expiring prefixes need not be handled anymore as the kernel has been
instructed not to create routes for DHCPv6 assigned addresses via the
IFA_F_NOPREFIXROUTE flag.
The IFA_F_NOPREFIXROUTE flag prevents the kernel from creating new onlink
prefixes when a DHCPv6 IPv6 address with a prefix length is set from user
space. IPv6 routing will follow the onlink status from Router Advertisment
Prefix Information options or any manually set route, which is the correct
thing to do.
As this flag has a larger value than what fits into an unsigned char, update
the flag attribute to an uint32_t and set it with an IFA_FLAGS attribute
when writing netlink messages to the kernel.
Once IPv6 addresses have been acquired, assign these to the interface
with the prefix lengths taken from the ICMPv6 Router Advertisement
handling code. The preferred and valid IPv6 address lifetimes are
handed to the kernel which will clean up them if not renewed in time.
When a prefix announced via Router Advertisements expires, find all
addresses that match that prefix and update the address to have a
prefix length of 128 causing the prefix to be off-link.
When ICMPv6 Other information is received, enable Information request
in DHCPv6. If the DHCPv6 client already exists, only update the client
if there is a transition from Other to Managed state.
