delta/samba.git/lib/tsocket, branch master

lib:tsocket: Fix code spelling

2023-04-14T05:25:33+00:00

Signed-off-by: Andreas Schneider 
Reviewed-by: Joseph Sutton

tsocket: Increase tcp_user_timeout max_loops

2023-03-14T06:16:30+00:00

Often, on rackspace GitLab CI runners, we get:

UNEXPECTED(failure): samba.unittests.tsocket_tstream.test_tstream_more_tcp_user_timeout_spin(none)
REASON: Exception: Exception: 0xf == 0xf
../../lib/tsocket/tests/test_tstream.c:405: error: Failure!

This allows us more spins before we fail the test.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=15328
Signed-off-by: Andrew Bartlett 
Reviewed-by: Joseph Sutton

lib/tsocket: fix a typo in the tsocket guide doc

2023-01-17T18:23:18+00:00

Signed-off-by: Björn Baumbach 
Reviewed-by: Ralph Boehme 

Autobuild-User(master): Björn Baumbach 
Autobuild-Date(master): Tue Jan 17 18:23:18 UTC 2023 on sn-devel-184

tsocket: Fix the build on FreeBSD

2022-12-12T21:16:33+00:00

FreeBSD does not have TCP_USER_TIMEOUT

Signed-off-by: Volker Lendecke 
Reviewed-by: Jeremy Allison

lib/tsocket: avoid endless cpu-spinning in tstream_bsd_fde_handler()

2022-10-19T16:14:36+00:00

There were some reports that strace output an LDAP server socket is in
CLOSE_WAIT state, returning EAGAIN for writev over and over (after a call to
epoll() each time).

In the tstream_bsd code the problem happens when we have a pending
writev_send, while there's no readv_send pending. In that case
we still ask for TEVENT_FD_READ in order to notice connection errors
early, so we try to call writev even if the socket doesn't report TEVENT_FD_WRITE.
And there are situations where we do that over and over again.

It happens like this with a Linux kernel:

    tcp_fin() has this:
        struct tcp_sock *tp = tcp_sk(sk);

        inet_csk_schedule_ack(sk);

        sk->sk_shutdown |= RCV_SHUTDOWN;
        sock_set_flag(sk, SOCK_DONE);

        switch (sk->sk_state) {
        case TCP_SYN_RECV:
        case TCP_ESTABLISHED:
                /* Move to CLOSE_WAIT */
                tcp_set_state(sk, TCP_CLOSE_WAIT);
                inet_csk_enter_pingpong_mode(sk);
                break;

It means RCV_SHUTDOWN gets set as well as TCP_CLOSE_WAIT, but
sk->sk_err is not changed to indicate an error.

    tcp_sendmsg_locked has this:
    ...
        err = -EPIPE;
        if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
                goto do_error;

        while (msg_data_left(msg)) {
                int copy = 0;

                skb = tcp_write_queue_tail(sk);
                if (skb)
                        copy = size_goal - skb->len;

                if (copy <= 0 || !tcp_skb_can_collapse_to(skb)) {
                        bool first_skb;

    new_segment:
                        if (!sk_stream_memory_free(sk))
                                goto wait_for_space;

    ...

    wait_for_space:
                set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
                if (copied)
                        tcp_push(sk, flags & ~MSG_MORE, mss_now,
                                 TCP_NAGLE_PUSH, size_goal);

                err = sk_stream_wait_memory(sk, &timeo);
                if (err != 0)
                        goto do_error;

It means if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN)) doesn't
hit as we only have RCV_SHUTDOWN and sk_stream_wait_memory returns
-EAGAIN.

    tcp_poll has this:

        if (sk->sk_shutdown & RCV_SHUTDOWN)
                mask |= EPOLLIN | EPOLLRDNORM | EPOLLRDHUP;

So we'll get EPOLLIN | EPOLLRDNORM | EPOLLRDHUP triggering
TEVENT_FD_READ and writev/sendmsg keeps getting EAGAIN.

So we need to always clear TEVENT_FD_READ if we don't
have readable handler in order to avoid burning cpu.
But we turn it on again after a timeout of 1 second
in order to monitor the error state of the connection.

And now that our tsocket_bsd_error() helper checks for POLLRDHUP,
we can check if the socket is in an error state before calling the
writable handler when TEVENT_FD_READ was reported.
Only on error we'll call the writable handler, which will pick
the error without calling writev().

BUG: https://bugzilla.samba.org/show_bug.cgi?id=15202

Signed-off-by: Stefan Metzmacher 
Reviewed-by: Ralph Boehme

lib/tsocket: remember the first error as tstream_bsd->error

2022-10-19T16:14:36+00:00

If we found that the connection is broken, there's no point
in trying to use it anymore, so just return the first error we detected.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=15202

Signed-off-by: Stefan Metzmacher 
Reviewed-by: Ralph Boehme

lib/tsocket: check for errors indicated by poll() before getsockopt(fd, SOL_SOCKET, SO_ERROR)

2022-10-19T16:14:36+00:00

This also returns an error if we got TCP_FIN from the peer,
which is only reported by an explicit POLLRDHUP check.

Also on FreeBSD getsockopt(fd, SOL_SOCKET, SO_ERROR) fetches
and resets the error, so a 2nd call no longer returns an error.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=15202

Signed-off-by: Stefan Metzmacher 
Reviewed-by: Ralph Boehme

lib/tsocket: split out tsocket_bsd_error() from tsocket_bsd_pending()

2022-10-19T16:14:36+00:00

This will be used on its own soon.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=15202

Signed-off-by: Stefan Metzmacher 
Reviewed-by: Ralph Boehme

lib/tsocket: Add tests for loop on EAGAIN

2022-10-19T16:14:36+00:00

BUG: https://bugzilla.samba.org/show_bug.cgi?id=15202

Pair-Programmed-With: Stefan Metzmacher 

Signed-off-by: Andrew Bartlett 
Signed-off-by: Stefan Metzmacher

selftest: test tsocket_address_inet_from_hostport_strings

2021-09-28T10:34:12+00:00

Signed-off-by: Uri Simchoni 
Reviewed-by: Andrew Bartlett 

Autobuild-User(master): Andrew Bartlett 
Autobuild-Date(master): Tue Sep 28 10:34:12 UTC 2021 on sn-devel-184