We strips out NLMSG_DONE piece from a multi-part message adding into the
receive queue only the messages containing actual data.
If we send a request to the kernel for getting the forwarding database table (just an example),
the response will be a multi-part message like below:
1. FDB entry 1;
2. FDB entry 2;
3. NLMSG_DONE;
We strip out "3. NLMSG_DONE;" part and places into the receive queue a pointer to
"1. FDB entry 1; 2. FDB entry 2".
But if the FDB table is empty, the respose from the kernel will look like below:
1. NLMSG_DONE;
We strip out "1. NLMSG_DONE;" part and since there is no actual data got, it continues
waiting until reaching timeout.
Therefore, a call to "sd_rtnl_call" to send and wait for a response from kernel will exit
with timeout which is interpreted as error in communication.
This patch puts the NLMSG_DONE message on the receive queue if it ends an empty multi-part
message. This situation is detected in sd_rtnl_call() and in the callback code and NULL is
returned to the caller instead.
[tomegun:
- added/reworded commit message
- extend the same support to sd_rtnl_call_async()
- drop debug logging from library, we only do this if something is really wrong, but an
empty multi-part message is perfectly normal
- modernize the code we touch whilst we are at it]
Coverity was complaining that CMSG_NXTHDR is used without
checking the return value. In this case it cannot fail, but
it is a good excuse to simplify the function a bit.
CID #1261726.
Do not rely on nl_pid == 0, but check the groups instead. We currently avoid using
nl_pid == 0 for unicast anyway, so this should be redundant, but let's try to be
correct.
The error code is called EDEADLK, stop using legacy names like EDEADLOCK.
Note that _some_ weird architectures define them differently (namely, mips
and sparc), but on all sane architectures they're exactly the same. So
stay with the widely used code, which is EDEADLK.
"Notifications are of informal nature and no reply is expected, therefore the
sequence number is typically set to 0."[1]
If networkd is started soon after recent netlink activity, then there
will be messages with sequence number 0 in the buffer.
The first thing networkd does is to request a dump of all the links. If
it uses sequence number 0 for this, then it may confuse the dump request's
response with that of a notification.
This will result in it failing to properly enumerate all the links,
but more importantly, when it comes to enumerate all the addresses, it
will still have the link dump in progress, so the address enumeration
will fail with -EBUSY.
[1]: http://www.infradead.org/~tgr/libnl/doc/core.html#core_msg_types
[tomegun: sequence -> serial]
If we receive an sd_bus_message from the kernel, m->kdbus will contain
additional items that cannot be used when sending a message. Therefore,
always remarshal the message if it is used again.
Usually when using loop_read(), we want to read the full buffer.
Add a helper that mirrors loop_write(), and returns 0 when full buffer
was read, and an error otherwise.
Use -ENODATA for the short read, to distinguish it from a read error.
Currently the code will silently blank out events if there are more
then 512 epoll events, causing them never to be handled at all. This
patch removes the cap on the number of events for epoll_wait, thereby
avoiding this issue.
After some reconsideration, we decided to move the binary protocol
back to 64-bit wide UIDs and GIDs. After all, it should be possible
to redefine [gu]id_t to uint64_t and things should continue to
work. As we want to avoid such data types in kdbus.h, let's move
back to 64-bit values and be safe.
In sd-bus, we have to do a translation between uint64_t and gid_t
now for supplementary gids.
Some inline comments have also been updated in kdbus upstream.
Introduce BindCarrier= to indicate the set of links that determine if
the current link should be brought UP or DOWN.
[tomegun: add a bit to commit message]
The kernel part of kdbus does not allow userspace to make any assumption on
which unique address the first user on the bus will get.
Instead, use sd_bus_get_unique_name() to get the server's address.
Follow two small changes in the kdbus API:
* Flags are now returned in cmd->return_flags by KDBUS_CMD_NAME_ACQUIRE
* struct kdbus_item_list has been dropped. The information stored in
this struct was redundant since awhile already, as all commands
report their returned slice size anyway.
This change exposed a bug in kernel headers:
/usr/include/linux/if_bridge.h:184:20: error: field 'ip6' has incomplete type
struct in6_addr ip6;
^
/usr/include/linux/if_tunnel.h:76:19: error: field 'prefix' has incomplete type
struct in6_addr prefix;
^
Include <sys/socket.h> from util.h and bus-message.h in order to
build errors like the ones below on kdbus enabled systems.
./src/shared/util.h:976:32: warning: its scope is only this definition or declaration, which is probably not what you want
In file included from src/libsystemd/sd-bus/bus-kernel.c:37:0:
./src/shared/util.h:1081:28: warning: 'struct msghdr' declared inside parameter list
void cmsg_close_all(struct msghdr *mh);
^
CC src/libsystemd/sd-bus/libsystemd_la-bus-creds.lo
In file included from src/libsystemd/sd-bus/bus-creds.c:25:0:
./src/shared/util.h:976:32: warning: 'struct ucred' declared inside parameter list
int getpeercred(int fd, struct ucred *ucred);
^
This patch removes includes that are not used. The removals were found with
include-what-you-use which checks if any of the symbols from a header is
in use.
Also, allow clients to alter their own objects without any further
priviliges. i.e. this allows clients to kill and lock their own sessions
without involving PK.
Most of our client tools want to set this bit for all their method
calls, even though it defaults to off in sd-bus, and rightfully so.
Hence, to simplify thing, introduce a per sd_bus-object flag that sets
the default value for all messages created on the connection.
sd_event_wait() returning 0 usually means that it timed out, which means it must
have been idle. However, sd_event_wait() may return 0 in case an event was triggered
but it turned out there was nothing to do. Make the check for idle explicit to avoid
this edge-case.
include-what-you-use automatically does this and it makes finding
unnecessary harder to spot. The only content of poll.h is a include
of sys/poll.h so should be harmless.
Alin Rauta
Zbigniew Jędrzejewski-Szmek
Tom Gundersen
David Herrmann
Richard Maw
Shawn Landden
Hannes Reinecke
Lennart Poettering
Daniel Mack
Thomas Hindoe Paaboel Andersen
Cristian Rodríguez