socket-util: Report POLLHUP as an error while connection completion checking.

Otherwise failed non-blocking connection could be reported as
connected. This causes errors in all following operations with the
socket.

At least this is true on FreeBSD, where POLLHUP could be set without
POLLERR.

For example, stream_open_block() tests fails with the following error
reporting successful connection to the 'WRONG_PORT':

  ./ovsdb-idl.at:1817:
             $PYTHON2 $srcdir/test-stream.py tcp:127.0.0.1:$WRONG_PORT
  stdout:
  ./ovsdb-idl.at:1817: exit code was 0, expected 1
  2399. ovsdb-idl.at:1817:  FAILED (ovsdb-idl.at:1817)

Also added new tests to track this issue in C library:
  'Check Stream open block - C - tcp'
  'Check Stream open block - C - tcp6'

CC: Numan Siddique <nusiddiq@redhat.com>
Fixes: c1aa16d191 ("ovs python: ovs.stream.open_block() returns success even if the remote is unreachable")
Fixes: d6cedfd9d2 ("socket-util: Avoid using SO_ERROR.")
Signed-off-by: Ilya Maximets <i.maximets@samsung.com>
Signed-off-by: Ben Pfaff <blp@ovn.org>

lib/socket-util.c

@@ -285,7 +285,7 @@ check_connection_completion(int fd)
     }
 #endif
     if (retval == 1) {
-        if (pfd.revents & POLLERR) {
+        if (pfd.revents & (POLLERR | POLLHUP)) {
             ssize_t n = send(fd, "", 1, 0);
             if (n < 0) {
                 return sock_errno();

python/ovs/socket_util.py

@@ -178,7 +178,7 @@ def check_connection_completion(sock):
     pfds = p.poll(0)
     if len(pfds) == 1:
         revents = pfds[0][1]
-        if revents & ovs.poller.POLLERR:
+        if revents & ovs.poller.POLLERR or revents & ovs.poller.POLLHUP:
             try:
                 # The following should raise an exception.
                 sock.send("\0".encode(), socket.MSG_DONTWAIT)

tests/.gitignore

@@ -51,6 +51,7 @@
 /test-sha1
 /test-skiplist
 /test-stp
+/test-stream
 /test-strtok_r
 /test-timeval
 /test-type-props

tests/automake.mk

@@ -436,6 +436,10 @@ endif
 
 tests_ovstest_LDADD = lib/libopenvswitch.la ovn/lib/libovn.la
 
+noinst_PROGRAMS += tests/test-stream
+tests_test_stream_SOURCES = tests/test-stream.c
+tests_test_stream_LDADD = lib/libopenvswitch.la
+
 noinst_PROGRAMS += tests/test-strtok_r
 tests_test_strtok_r_SOURCES = tests/test-strtok_r.c
 

tests/ovsdb-idl.at

@@ -1785,6 +1785,23 @@ OVSDB_CHECK_IDL_COMPOUND_INDEX_WITH_REF([set, simple3 idl-compound-index-with-re
 008: End test
 ]])
 
+m4_define([CHECK_STREAM_OPEN_BLOCK],
+  [AT_SETUP([Check Stream open block - C - $1])
+   AT_SKIP_IF([test "$1" = "tcp6" && test "$IS_WIN32" = "yes"])
+   AT_SKIP_IF([test "$1" = "tcp6" && test "$HAVE_IPV6" = "no"])
+   AT_KEYWORDS([Check Stream open block $1])
+   AT_CHECK([ovsdb_start_idltest "ptcp:0:$2"])
+   PARSE_LISTENING_PORT([ovsdb-server.log], [TCP_PORT])
+   WRONG_PORT=$(($TCP_PORT+1))
+   AT_CHECK([test-stream tcp:$2:$TCP_PORT], [0], [ignore])
+   AT_CHECK([test-stream tcp:$2:$WRONG_PORT], [1], [ignore], [ignore])
+   OVSDB_SERVER_SHUTDOWN
+   AT_CHECK([test-stream tcp:$2:$TCP_PORT], [1], [ignore], [ignore])
+   AT_CLEANUP])
+
+CHECK_STREAM_OPEN_BLOCK([tcp], [127.0.0.1])
+CHECK_STREAM_OPEN_BLOCK([tcp6], [[[::1]]])
+
 m4_define([CHECK_STREAM_OPEN_BLOCK_PY],
   [AT_SETUP([$1])
    AT_SKIP_IF([test $2 = no])

tests/test-stream.c

@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2018 Ilya Maximets <i.maximets@samsung.com>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <config.h>
+
+#include "fatal-signal.h"
+#include "openvswitch/vlog.h"
+#include "stream.h"
+#include "util.h"
+
+VLOG_DEFINE_THIS_MODULE(test_stream);
+
+int
+main(int argc, char *argv[])
+{
+    int error;
+    struct stream *stream;
+
+    fatal_ignore_sigpipe();
+    set_program_name(argv[0]);
+
+    if (argc < 2) {
+        ovs_fatal(0, "usage: %s REMOTE", argv[0]);
+    }
+
+    error = stream_open_block(stream_open(argv[1], &stream, DSCP_DEFAULT),
+                              &stream);
+    if (error) {
+        VLOG_ERR("stream_open_block(%s) failure: %s",
+                 argv[1], ovs_strerror(error));
+    }
+    return (error || !stream) ? 1 : 0;
+}