ipautil: check for open ports on all resolved IPs

When a hostname is provided to host_port_open, it should check if
ports are open for ALL IPs that are resolved from the hostname, instead
of checking whether the port is reachable on at least one of the IPs.

https://fedorahosted.org/freeipa/ticket/6522

Reviewed-By: Petr Spacek <pspacek@redhat.com>

install/tools/ipa-replica-conncheck

@@ -381,8 +381,9 @@ def port_check(host, port_list):
     ports_udp_warning = []  # conncheck could not verify that port is open
     for port in port_list:
         try:
-            port_open = ipautil.host_port_open(host, port.port,
-                    port.port_type, socket_timeout=CONNECT_TIMEOUT)
+            port_open = ipautil.host_port_open(
+                host, port.port, port.port_type,
+                socket_timeout=CONNECT_TIMEOUT, log_errors=True)
         except socket.gaierror:
             raise RuntimeError("Port check failed! Unable to resolve host name '%s'" % host)
         if port_open:

ipapython/ipautil.py

@@ -55,6 +55,12 @@ GEN_PWD_LEN = 22
 GEN_TMP_PWD_LEN = 12  # only for OTP password that is manually retyped by user
 
 
+PROTOCOL_NAMES = {
+    socket.SOCK_STREAM: 'tcp',
+    socket.SOCK_DGRAM: 'udp'
+}
+
+
 class UnsafeIPAddress(netaddr.IPAddress):
     """Any valid IP address with or without netmask."""
 
@@ -866,15 +872,21 @@ def user_input(prompt, default = None, allow_empty = True):
                 return ret
 
 
-def host_port_open(host, port, socket_type=socket.SOCK_STREAM, socket_timeout=None):
+def host_port_open(host, port, socket_type=socket.SOCK_STREAM,
+                   socket_timeout=None, log_errors=False):
+    """
+    host: either hostname or IP address;
+          if hostname is provided, port MUST be open on ALL resolved IPs
+
+    returns True is port is open, False otherwise
+    """
+    port_open = True
+
+    # port has to be open on ALL resolved IPs
     for res in socket.getaddrinfo(host, port, socket.AF_UNSPEC, socket_type):
         af, socktype, proto, _canonname, sa = res
-        try:
         try:
             s = socket.socket(af, socktype, proto)
-            except socket.error:
-                s = None
-                continue
 
             if socket_timeout is not None:
                 s.settimeout(socket_timeout)
@@ -884,15 +896,27 @@ def host_port_open(host, port, socket_type=socket.SOCK_STREAM, socket_timeout=No
             if socket_type == socket.SOCK_DGRAM:
                 s.send('')
                 s.recv(512)
-
-            return True
         except socket.error:
-            pass
+            port_open = False
+
+            if log_errors:
+                msg = ('Failed to connect to port %(port)d %(proto)s on '
+                       '%(addr)s' % dict(port=port,
+                                         proto=PROTOCOL_NAMES[socket_type],
+                                         addr=sa[0]))
+
+                # Do not log udp failures as errors (to be consistent with
+                # the rest of the code that checks for open ports)
+                if socket_type == socket.SOCK_DGRAM:
+                    root_logger.warning(msg)
+                else:
+                    root_logger.error(msg)
         finally:
             if s:
                 s.close()
+                s = None
 
-    return False
+    return port_open
 
 
 def reverse_record_exists(ip_address):