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);
}
}
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.
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.
Move ICMPv6 Router Solicitation sending after timer computation so
that timers are already set up when the packet is being sent. This
makes it possible to create a test that inspects Router
Solicitation timer values when the Router Solicitation is sent out
on the network.
Instead of sending a fixed amount of Router Solicitiations, implement
the backoff algorithm proposed in RFC 7559. The backoff algorithm is
the same as used by DHCPv6.
Time out after 12s as specified in RFC 4861 in order not to delay
setting up a link for too long while sending Router Solicitations
in the background. Notice that after this change the callback will
receive a SD_NDISC_EVENT_TIMEOUT timeout event, and at a later point
when a router appears, a received Router Advertisment will cause the
callback to be called again with the SD_NDISC_EVENT_ROUTER event.
Receive Router Solicitations and send a unicast Router Advertisment
in response. Refactor ICMPv6 packet handling code so that the common
ICMPv6 validation parts are reused between the existing router
discovery and the new functionality adding reception of Router
Solicitation messages.
Reset also the counter for number of Router Solicitations sent when
the associated file descriptor is closed and the event source
unreferenced. With this change the router discovery can now be
stopped and restarted arbitrary many times.
Apparently newer gcc versions are a bit more forgiving when assigning an
"unsigned char*" pointer to something of a different type. Let's add the
missing cast so that old gcc versions are fine, too.
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
Let's better check the size before we subtract. Also, let's change the size
argument to size_t, as it cannot be signed anyway.
Finally, use EBADMSG for indicating invalid packets, like we do everywhere
else.
There's no "client" object, in both cases. There's only "nd".
This wasn't noticed before, as the context object is currently not actually
used by the log macros.
assert_return() should only be used to validate user-facing parameters and
state, assert() should be used for checking our own internal state and
parameters.
After all, it's actually used for resetting the state, not only for the initial
initialization.
While we are at it, also simplify the error path for
sd_ndisc_discovery_start().
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.
Merge separate two error handling statements into two nested ifs.
This looks cleaner, and avoids a gcc warning about *prefix being
uninitialized.
While at it, fix identation of logging statements elsewhere in the
file.
GLIB has recently started to officially support the gcc cleanup
attribute in its public API, hence let's do the same for our APIs.
With this patch we'll define an xyz_unrefp() call for each public
xyz_unref() call, to make it easy to use inside a
__attribute__((cleanup())) expression. Then, all code is ported over to
make use of this.
The new calls are also documented in the man pages, with examples how to
use them (well, I only added docs where the _unref() call itself already
had docs, and the examples, only cover sd_bus_unrefp() and
sd_event_unrefp()).
This also renames sd_lldp_free() to sd_lldp_unref(), since that's how we
tend to call our destructors these days.
Note that this defines no public macro that wraps gcc's attribute and
makes it easier to use. While I think it's our duty in the library to
make our stuff easy to use, I figure it's not our duty to make gcc's own
features easy to use on its own. Most likely, client code which wants to
make use of this should define its own:
#define _cleanup_(function) __attribute__((cleanup(function)))
Or similar, to make the gcc feature easier to use.
Making this logic public has the benefit that we can remove three header
files whose only purpose was to define these functions internally.
See #2008.
See https://tools.ietf.org/html/rfc4861#section-4.2. Some routers (dnsmasq) will send packets
from global addresses, which would break the default route setup, so ignore those.
This is also what the kernel does.