Commit Graph

78 Commits

Author SHA1 Message Date
Willy Tarreau
427c846cc9 MINOR: protocol: add a ->drain() function at the connection control layer
This is what we need to drain pending incoming data from an connection.
The code was taken from conn_sock_drain() without the connection-specific
stuff. It still takes a connection for now for API simplicity.
2020-12-11 16:26:00 +01:00
Willy Tarreau
586f71b43f REORG: connection: move the socket iocb (conn_fd_handler) to sock.c
conn_fd_handler() is 100% specific to socket code. It's about time
it moves to sock.c which manipulates socket FDs. With it comes
conn_fd_check() which tests for the socket's readiness. The ugly
connection status check at the end of the iocb was moved to an inlined
function in connection.h so that if we need it for other socket layers
it's not too hard to reuse.

The code was really only moved and not changed at all.
2020-12-11 16:26:00 +01:00
Willy Tarreau
de471c4655 MINOR: protocol: add a set of ctrl_init/ctrl_close methods for setup/teardown
Currnetly conn_ctrl_init() does an fd_insert() and conn_ctrl_close() does an
fd_delete(). These are the two only short-term obstacles against using a
non-fd handle to set up a connection. Let's have pur these into the protocol
layer, along with the other connection-level stuff so that the generic
connection code uses them instead. This will allow to define new ones for
other protocols (e.g. QUIC).

Since we only support regular sockets at the moment, the code was placed
into sock.c and shared with proto_tcp, proto_uxst and proto_sockpair.
2020-12-08 15:50:56 +01:00
Willy Tarreau
b4daeeb094 MINOR: sock: add a check against cross worker<->master socket activities
Given that the previous issues caused spurious worker socket wakeups in
the master for inherited FDs that couldn't be closed, let's add a strict
test in the I/O callback to make sure that an accept() event is always
caught by the appropriate type of process (master for master listeners,
worker for worker listeners).
2020-11-04 15:05:50 +01:00
Willy Tarreau
a4380b211f MEDIUM: listeners: make use of fd_want_recv_safe() to enable early receivers
We used to refrain from calling fd_want_recv() if fd_updt was not allocated
but it's not the right solution as this does not allow the FD to be set.
Instead, let's use the new fd_want_recv_safe() which will update the FD and
create an update entry only if possible. In addition, the equivalent test
before calling fd_stop_recv() was removed as totally useless since there's
not fd_updt creation in this case.
2020-11-04 14:22:42 +01:00
Willy Tarreau
22ccd5ebaf BUG/MEDIUM: listener: make the master also keep workers' inherited FDs
In commit 374e9af35 ("MEDIUM: listener: let do_unbind_listener() decide
whether to close or not") it didn't appear necessary to have the master
process keep open the workers' inherited FDs. But this is actually
necessary to handle the reload on "bind fd@foo" situations, otherwise
the FD may be reassigned and the new socket cannot be set up, sometimes
causing "socket operation on non-socket" or other types of errors.

William found that this was the cause for the consistent failures of the
abns regtest, which already used to fail very often before this and was
as such marked as broken.

Interestingly I didn't have this issue with my test configs because
the FD number I used was higher and within the range of other listening
sockets. But this means that one of these wouldn't work as expected.

No backport is needed, this was introduced as part of the listeners
rework in 2.3.
2020-11-04 14:22:42 +01:00
Willy Tarreau
a74cb38e7c MINOR: protocol: register the receiver's I/O handler and not the protocol's
Now we define a new sock_accept_iocb() for socket-based stream protocols
and use it as a wrapper for listener_accept() which now takes a listener
and not an FD anymore. This will allow the receiver's I/O cb to be
redefined during registration, and more specifically to get rid of the
hard-coded hacks in protocol_bind_all() made for syslog.

The previous ->accept() callback in the protocol was removed since it
doesn't have anything to do with accept() anymore but is more generic.
A few places where listener_accept() was compared against the FD's IO
callback for debugging purposes on the CLI were updated.
2020-10-15 21:47:56 +02:00
Willy Tarreau
344b8fcf87 MINOR: sockpair: implement sockpair_accept_conn() to accept a connection
This is the same as previous commit, but this time for the sockpair-
specific stuff, relying on recv_fd_uxst() instead of accept(), so the
code is simpler. The various errno cases are handled like for regular
sockets, though some of them will probably never happen, but this does
not hurt.
2020-10-15 21:47:56 +02:00
Willy Tarreau
f1dc9f2f17 MINOR: sock: implement sock_accept_conn() to accept a connection
The socket-specific accept() code in listener_accept() has nothing to
do there. Let's move it to sock.c where it can be significantly cleaned
up. It will now directly return an accepted connection and provide a
status code instead of letting listener_accept() deal with various errno
values. Note that this doesn't support the sockpair specific code.

The function is now responsible for dealing with its own receiver's
polling state and calling fd_cant_recv() when facing EAGAIN.

One tiny change from the previous implementation is that the connection's
sockaddr is now allocated before trying accept(), which saves a memcpy()
of the resulting address for each accept at the expense of a cheap
pool_alloc/pool_free on the final accept returning EAGAIN. This still
apparently slightly improves accept performance in microbencharks.
2020-10-15 21:47:56 +02:00
Willy Tarreau
7d053e4211 MINOR: sock: rename sock_accept_conn() to sock_accepting_conn()
This call was introduced by commit 5ced3e887 ("MINOR: sock: add
sock_accept_conn() to test a listening socket") but is actually quite
confusing because it makes one think the socket will accept a connection
(which is what we want to have in a new function) while it only tells
whether it's configured to accept connections. Let's call it
sock_accepting_conn() instead.

The same change was applied to sockpair which had the same issue.
2020-10-15 21:47:56 +02:00
Willy Tarreau
5ced3e8879 MINOR: sock: add sock_accept_conn() to test a listening socket
At several places we need to check if a socket is still valid and still
willing to accept connections. Instead of open-coding this, each time,
let's add a new function for this.
2020-10-13 18:15:33 +02:00
Willy Tarreau
f58b8db47b MEDIUM: receivers: add an rx_unbind() method in the protocols
This is used as a generic way to unbind a receiver at the end of
do_unbind_listener(). This allows to considerably simplify that function
since we can now let the protocol perform the cleanup. The generic code
was moved to sock.c, along with the conditional rx_disable() call. Now
the code also supports that the ->disable() function of the protocol
which acts on the listener performs the close itself and adjusts the
RX_F_BUOND flag accordingly.
2020-10-09 18:44:36 +02:00
Willy Tarreau
e70c7977f2 MINOR: sock: provide a set of generic enable/disable functions
These will be used on receivers, to enable or disable receiving on a
listener, which most of the time just consists in enabling/disabling
the file descriptor.

We have to take care of the existence of fd_updt to know if we may
or not call fd_{want,stop}_recv() since it's not permitted in very
early boot.
2020-10-09 11:27:30 +02:00
Willy Tarreau
f1f660978c MINOR: protocol: retrieve the family-specific fields from the family
We now take care of retrieving sock_family, l3_addrlen, bind(),
addrcmp(), get_src() and get_dst() from the protocol family and
not just the protocol itself. There are very few places, this was
only seldom used. Interestingly in sock_inet.c used to rely on
->sock_family instead of ->sock_domain, and sock_unix.c used to
hard-code PF_UNIX instead of using ->sock_domain.

Also it appears obvious we have something wrong it the protocol
selection algorithm because sock_domain is the one set to the custom
protocols while it ought to be sock_family instead, which would avoid
having to hard-code some conversions for UDP namely.
2020-09-16 22:08:07 +02:00
Willy Tarreau
c049c0d5ad MINOR: sock: make sock_find_compatible_fd() only take a receiver
We don't need to have a listener anymore to find an fd, a receiver with
its settings properly set is enough now.
2020-09-16 22:08:07 +02:00
Willy Tarreau
3fd3bdc836 MINOR: receiver: move the FOREIGN and V6ONLY options from listener to settings
The new RX_O_FOREIGN, RX_O_V6ONLY and RX_O_V4V6 options are now set into
the rx_settings part during the parsing, so that we don't need to adjust
them in each and every listener anymore. We have to keep both v4v6 and
v6only due to the precedence from v6only over v4v6.
2020-09-16 22:08:07 +02:00
Willy Tarreau
818a92e87a MINOR: listener: prefer to retrieve the socket's settings via the receiver
Some socket settings used to be retrieved via the listener and the
bind_conf. Now instead we use the receiver and its settings whenever
appropriate. This will simplify the removal of the dependency on the
listener.
2020-09-16 22:08:07 +02:00
Willy Tarreau
4dfabfed13 MINOR: listener: make sock_find_compatible_fd() check the socket type
sock_find_compatible_fd() can now access the protocol via the receiver
hence it can access its socket type and know whether the receiver has
dgram or stream sockets, so we don't need to hack around AF_CUST_UDP*
anymore there.
2020-09-16 22:08:07 +02:00
Willy Tarreau
b743661f04 REORG: listener: move the listener's proto to the receiver
The receiver is the one which depends on the protocol while the listener
relies on the receiver. Let's move the protocol there. Since there's also
a list element to get back to the listener from the proto list, this list
element (proto_list) was moved as well. For now when scanning protos, we
still see listeners which are linked by their rx.proto_list part.
2020-09-16 22:08:05 +02:00
Willy Tarreau
371590661e REORG: listener: move the listening address to a struct receiver
The address will be specific to the receiver so let's move it there.
2020-09-16 22:08:01 +02:00
Willy Tarreau
be56c1038f MINOR: listener: move the network namespace to the struct settings
The netns is common to all listeners/receivers and is used to bind the
listening socket so it must be in the receiver settings and not in the
listener. This removes some yet another set of unnecessary loops.
2020-09-16 20:13:13 +02:00
Willy Tarreau
7e307215e8 MINOR: listener: move the interface to the struct settings
The interface is common to all listeners/receivers and is used to bind
the listening socket so it must be in the receiver settings and not in
the listener. This removes some unnecessary loops.
2020-09-16 20:13:13 +02:00
Willy Tarreau
9dbb6c43ce MINOR: sock: distinguish dgram from stream types when retrieving old sockets
For now we still don't retrieve dgram sockets, but the code must be able
to distinguish them before we switch to receivers. This adds a new flag
to the xfer_sock_list indicating that a socket is of type SOCK_DGRAM. The
way to set the flag for now is by looking at the dummy address family which
equals AF_CUST_UDP{4,6} in this case (given that other dgram sockets are not
yet supported).
2020-08-28 19:26:39 +02:00
Willy Tarreau
a2c17877b3 MINOR: sock: do not use LI_O_* in xfer_sock_list anymore
We'll want to store more info there and some info that are not represented
in listener options at the moment (such as dgram vs stream) so let's get
rid of these and instead use a new set of options (SOCK_XFER_OPT_*).
2020-08-28 19:26:38 +02:00
Willy Tarreau
429617459d REORG: sock: move get_old_sockets() from haproxy.c
The new function was called sock_get_old_sockets() and was left as-is
except a minimum amount of style lifting to make it more readable. It
will never be awesome anyway since it's used very early in the boot
sequence and needs to perform socket I/O without any external help.
2020-08-28 19:24:55 +02:00
Willy Tarreau
2d34a710b1 MINOR: sock: implement sock_find_compatible_fd()
This is essentially a merge from tcp_find_compatible_fd() and
uxst_find_compatible_fd() that relies on a listener's address and
compare function and still checks for other variations. For AF_INET6
it compares a few of the listener's bind options. A minor change for
UNIX sockets is that transparent mode, interface and namespace used
to be ignored when trying to pick a previous socket while now if they
are changed, the socket will not be reused. This could be refined but
it's still better this way as there is no more risk of using a
differently bound socket by accident.

Eventually we should not pass a listener there but a set of binding
parameters (address, interface, namespace etc...) which ultimately will
be grouped into a receiver. For now this still doesn't exist so let's
stick to the listener to break dependencies in the rest of the code.
2020-08-28 18:51:36 +02:00
Willy Tarreau
063d47d136 REORG: listener: move xfer_sock_list to sock.{c,h}.
This will be used for receivers as well thus it is not specific to
listeners but to sockets.
2020-08-28 18:51:36 +02:00
Willy Tarreau
18b7df7a2b REORG: sock: start to move some generic socket code to sock.c
The new file sock.c will contain generic code for standard sockets
relying on file descriptors. We currently have way too much duplication
between proto_uxst, proto_tcp, proto_sockpair and proto_udp.

For now only get_src, get_dst and sock_create_server_socket were moved,
and are used where appropriate.
2020-08-28 18:51:36 +02:00