Found by inspecting results of running this small program:
int main(int argc, const char **argv) {
for (int i = 1; i < argc; i++) {
FILE *f;
char line[1024], prev[1024], *r;
int lineno;
prev[0] = '\0';
lineno = 1;
f = fopen(argv[i], "r");
if (!f)
exit(1);
do {
r = fgets(line, sizeof(line), f);
if (!r)
break;
if (strcmp(line, prev) == 0)
printf("%s:%d: error: dup %s", argv[i], lineno, line);
lineno++;
strcpy(prev, line);
} while (!feof(f));
fclose(f);
}
}
An earlier commit 0e408b82b (dhcp6-client: handle IAID with value zero)
introduced a flag to sd_dhcp6_client to distinguish between an unset
IAID and a value set to zero.
However, that was not sufficient and broke leaving the setting
uninitialized in networkd configuration. The configuration parsing
also must distinguish between the default, unset value and an
explict zero configuration.
Fixes: 0e408b82b8
Request prefix delegation for a new downstream link that is enabled
after any number of upstream DHCPv6 links. Submit the request after
the link has been configured with a link-local address.
If the upstream DHCPv6 client has already been configured to request
prefixes, attempt to re-assign any possible prefixes between the
already existing links and the new one. If no prefixes are yet
acquired, nothing will happen right away and any prefixes will be
distributed after a reply from the DHCPv6 server.
If none of the already existing downstream links have requested
DHCPv6 prefixes to be assigned, enable prefix delegation for each
client and restart them one by one if they are already running. This
causes the DHCPv6 clients to re-acquire addresses and prefixes and
to re-distribute them to all links when receiving an updated
response from their respective DHCPv6 servers. If the DHCPv6 client
in question was not already running, it is set to request prefixes
but not restarted.
When an error occurs while setting or restarting the DHCPv6 client,
log the incident and move over to the next link.
Fixes#9758.
Start with route set to NULL should there be no route created. Remove
the explicit route_free as the _cleanup_ will take care of that after
the continue;.
In order to shut down networkd properly, the delegated routes added
need to be removed properly, and as error reporting is wanted, the
network link is needed in the debug output.
Solve this by calling manager_dhcp6_prefix_remove_all(), which will
remove each prefix stored in the Manager structure, and while doing
that reference each link so that it isn't freed before the route
removal callback is called. This in turn causes the network link to
be referenced once more, and an explicit hashmap_remove() must be
called to remove the network link from the m->links hashmap.
Also, since the registered callback is not called when the DHCPv6
client is stopped with sd_dhcp6_client_stop(), an explicit call
to dhcp6_lease_pd_prefix_lost() needs to be made to clean up any
unreachable routes set up for the delegated prefixes.
Instead of setting many small unreachable routes for each of the /64
subnets that were not distributed between the links requesting delegated
prefixes, set one unreachable route for the size of the delegated
prefix. Each subnet asssigned to a downstream link will add a routable
subnet for that link, and as the subnet assigned to the downstream link
has a longer prefix than the whole delegated prefix, the downstream
link subnet routes are preferred over the unroutable delegated one.
The unreachable route is not added when the delegated prefix is exactly
a /64 as the prefix size cannot be used to sort out the order of routing
into a bigger blocking subnet with the smaller /64 punching routable
"holes" into it.
When stopping the DHCPv6 client, the unroutable delegated prefix is
removed before the downstream link prefixes are unassigned.
RFC 7084, WPD-4, requires Customer Edge end routers to behave
according to the following:
"WPD-4: By default, the IPv6 CE router MUST initiate DHCPv6 prefix
delegation when either the M or O flags are set to 1 in a
received Router Advertisement (RA) message. Behavior of the
CE router to use DHCPv6 prefix delegation when the CE router
has not received any RA or received an RA with the M and the
O bits set to zero is out of scope for this document."
Since it cannot be automatically detected whether DHCPv6 is to be
operated as an CE end router or whether to initiate an Informational
exchange to obtain other useful network information via DHCPv6 when the
Router Advertisement 'O' bit is set, a 'ForceDHCPv6PDOtherInformation'
boolean network configuration option in the '[DHCP]' section of a is
introduced. Setting this option causes DHCPv6 to be started in stateful
mode, although only the 'O' bit is seen in the Router Advertisement.
When 'ForceDHCPv6PDOtherInformation' is set and the Router Advertisement
has only the Other information 'O' bit set, disable requests for IA_NA
addresses.
Fixes#9745.
When computing the next network prefix to assign, compute the next
prefix to allocate based on the intended /64 assignment, not the
given prefix length for the whole prefix, e.g. /48, given to
systemd-networkd.
Fixes#9626.
This part of the copyright blurb stems from the GPL use recommendations:
https://www.gnu.org/licenses/gpl-howto.en.html
The concept appears to originate in times where version control was per
file, instead of per tree, and was a way to glue the files together.
Ultimately, we nowadays don't live in that world anymore, and this
information is entirely useless anyway, as people are very welcome to
copy these files into any projects they like, and they shouldn't have to
change bits that are part of our copyright header for that.
hence, let's just get rid of this old cruft, and shorten our codebase a
bit.
They are not needed, because anything that is non-zero is converted
to true.
C11:
> 6.3.1.2: When any scalar value is converted to _Bool, the result is 0 if the
> value compares equal to 0; otherwise, the result is 1.
https://stackoverflow.com/questions/31551888/casting-int-to-bool-in-c-c
This drops a good number of type-specific _cleanup_ macros, and patches
all users to just use the generic ones.
In most recent code we abstained from defining type-specific macros, and
this basically removes all those added already, with the exception of
the really low-level ones.
Having explicit macros for this is not too useful, as the expression
without the extra macro is generally just 2ch wider. We should generally
emphesize generic code, unless there are really good reasons for
specific code, hence let's follow this in this case too.
Note that _cleanup_free_ and similar really low-level, libc'ish, Linux
API'ish macros continue to be defined, only the really high-level OO
ones are dropped. From now on this should really be the rule: for really
low-level stuff, such as memory allocation, fd handling and so one, go
ahead and define explicit per-type macros, but for high-level, specific
program code, just use the generic _cleanup_() macro directly, in order
to keep things simple and as readable as possible for the uninitiated.
Note that before this patch some of the APIs (notable libudev ones) were
already used with the high-level macros at some places and with the
generic _cleanup_ macro at others. With this patch we hence unify on the
latter.
Files which are installed as-is (any .service and other unit files, .conf
files, .policy files, etc), are left as is. My assumption is that SPDX
identifiers are not yet that well known, so it's better to retain the
extended header to avoid any doubt.
I also kept any copyright lines. We can probably remove them, but it'd nice to
obtain explicit acks from all involved authors before doing that.
The DHCPv6 client can obtain configuration parameters from a
DHCPv6 server through a rapid two-message exchange solicit and reply).
When the rapid commit option is enabled by both the DHCPv6 client and
the DHCPv6 server, the two-message exchange is used, rather than the default
four-method exchange (solicit, advertise, request, and reply). The two-message
exchange provides faster client configuration and is beneficial in environments
in which networks are under a heavy load.
Closes#5845
When receiving one or more prefixes with variable length, assign a
64 bit long prefix for each link that has been configured for DHCPv6
prefix delegation and is not using DHCPv6 to fetch IPv6 adresses.
Keep assigning prefixes with length 64 from each prefix received via
DHCPv6 as long as there are prefixes left. If the number of prefixes
available from a prefix received via DHCPv6 is smaller than the
number of links, continue with the next delegated prefix, if any.
Remember the prefixes used for each link by storing them in a hash
and checking the hash each time a prefix is to be delegated. If an
error occurs when assigning a prefix to a link, try assigning the
prefix to another link. If the error occurs while updating the
prefix, log the situation and continue delegating the rest of the
prefixes.
Request prefixes via DHCPv6 if there are networks that are
configured to distribute them. As specified in RFC 3633, a DHCPv6
client cannot redistribute the prefixes via Router Advertisements
on the same link. Ignore such networks, and print out a warning if
the link where DHCPv6 is enabled tries to do so.
Implement DHCPv6 option to exchange information about the Fully
Qualified Domain Name (FQDN) according to RFC 4704.
The RFC 4704 describes two models of operations in section 3,
currently only the second model is supported (DHCPv6 server
updates both the AAAA and the PTR RRs).
The existing DHCP Section Options SendHostname and Hostname are
sent as FQDN to the server. According to section 4.2 sending
only parts of its FQDN is allowed.
Fixes#4682.
This reworks sd-ndisc and networkd substantially to support IPv6 RA much more
comprehensively. Since the API is extended quite a bit networkd has been ported
over too, and the patch is not as straight-forward as one could wish. The
rework includes:
- Support for DNSSL, RDNSS and RA routing options in sd-ndisc and networkd. Two
new configuration options have been added to networkd to make this
configurable.
- sd-ndisc now exposes an sd_ndisc_router object that encapsulates a full RA
message, and has direct, friendly acessor functions for the singleton RA
properties, as well as an iterative interface to iterate through known and
unsupported options. The router object may either be retrieved from the wire,
or generated from raw data. In many ways the sd-ndisc API now matches the
sd-lldp API, except that no implicit database of seen data is kept. (Note
that sd-ndisc actually had a half-written, but unused implementaiton of such
a store, which is removed now.)
- sd-ndisc will now collect the reception timestamps of RA, which is useful to
make sd_ndisc_router fully descriptive of what it covers.
Fixes: #1079
dhcp6_request_address() was merely a function to switch the DHCPv6 client from "stateless" mode to "stateful" mode. It was also a one-way switch. Also, to (re)start the client, we would need to repeat separate function calls.
In this patch, dhcp6_request_address() is made a general starter/manager of the DHCPv6 client. It now takes an extra parameter so we will be specifying which mode the DHCPv6 client should be started in. Also it will keep track of the current mode and compare with the newly requested mode, and only restart the client in case there is a difference between them.
This also makes sure that the DHCPv6 client will be (re)started accordingly as per the Router Advertisement flags.
A field "index" is not particularly precise and also might conflict with libc's
index() function definition. Also, pretty much everywhere else we call this
concept "ifindex", including in networkd, the primary user of these libraries.
Hence, let's fix this up and call this "ifindex" everywhere here too.
Starting the DHCP client doesn't seem like dhcp6_request_address()'s responsibility anyway. Whenever it's called, sd_dhcp6_client_start() is unconditionally called outside of it as well. See ndisc_router_handler() and ndisc_handler() in networkd-ndisc.c.
Separate fields are replaced with a struct.
Second second duid type field is removed. The first field was used to carry
the result of DUIDType= configuration, and the second was either a copy of
this, or contained the type extracted from DuidRawData. The semantics are changed
so that the type specified in DUIDType is always used. DUIDRawData= no longer
overrides the type setting.
The networkd code is now more constrained than the sd-dhcp code:
DUIDRawData cannot have 0 length, length 0 is treated the same as unsetting.
Likewise, it is not possible to set a DUIDType=0. If it ever becomes necessary
to set type=0 or a zero-length duid, the code can be changed to support that.
Nevertheless, I think that's unlikely.
This addresses #3127 § 1 and 3.
v2:
- rename DUID.duid, DUID.duid_len to DUID.raw_data, DUID.raw_data_len
Header files were organized in a way where the includer would add various
typedefs used by the includee before including it, resulting in a tangled
web of dependencies between files.
Replace this with the following logic:
networkd.h
/ \
networkd-link.h \
networkd-ipv4ll.h--\__\
networkd-fdb.h \
networkd-network.h netword-netdev-*.h
networkd-route.h \
networkd-netdev.h
If a pointer to a structure defined in a different header file is needed,
use a typedef line instead of including the whole header.
The ndisc client may trigger the dhcpv6 client to be started (this is the common case),
so we should allocate the dhcpv6 client whenever we allocate the ndisc one.
Enabling address acquisition, configuring the client and starting the client are now
split out. This to better handle the client being repeatedly enabled due to router
advertisements.
Exported header files should not include internal headers. Fix that.
Exported header files should not use the bool type. So far we opted to
stick to C89 for exported headers, and hence use "int" for bools in
them. Continue to do so.
Exported header files should have #include lines for everything they use
including inttypes.h and sys/types.h, so that they may be included in
any order.
Exported header files should have C++ guards, hence add them.
Exported header files should not use gcc extensions like #pragma once,
get rid of it.
There are more than enough calls doing string manipulations to deserve
its own files, hence do something about it.
This patch also sorts the #include blocks of all files that needed to be
updated, according to the sorting suggestions from CODING_STYLE. Since
pretty much every file needs our string manipulation functions this
effectively means that most files have sorted #include blocks now.
Also touches a few unrelated include files.
The routing information should be configured separately by ND, there is no need to
indicate the prefix again in the DHCPv6 addresses.
See discussion and related links at issue #1520.
The actual code rename will follow. The reason for the change of name is to make it
simpler and more uniform with how we name other libraries (we don't include the
underlying protocol). The new name also matches the naming in the kernel (which
is particularly relevent here as we expect to let the kernel do some parts of
the protocol and we do others).
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.
