Connection check program for replica installation

When connection between a master machine and future replica is not
sane, the replica installation may fail unexpectedly with
inconvenient error messages. One common problem is misconfigured
firewall.

This patch adds a program ipa-replica-conncheck which tests the
connection using the following procedure:

1) Execute the on-replica check testing the connection to master
2) Open required ports on local machine
3) Ask user to run the on-master part of the check OR run it
   automatically:
     a) kinit to master as default admin user with given password
     b) run the on-master part using ssh
4) When master part is executed, it checks connection back to
   the replica and prints the check result

This program is run by ipa-replica-install as mandatory part. It
can, however, be skipped using --skip-conncheck option.
ipa-replica-install now requires password for admin user to run
the command on remote master.

https://fedorahosted.org/freeipa/ticket/1107

1 files changed, 73 insertions, 0 deletions

diff --git a/ipapython/ipautil.py b/ipapython/ipautil.py
index acfd70cae..ed8f04af5 100644
--- a/ipapython/ipautil.py
+++ b/ipapython/ipautil.py
@@ -32,6 +32,7 @@ import copy
 import stat
 import shutil
 import urllib2
+import socket
 
 from ipapython import ipavalidate
 from types import *
@@ -1093,3 +1094,75 @@ def chkconfig_add(service_name):
 def chkconfig_del(service_name):
     run(["/sbin/chkconfig", "--del", service_name])
 
+def host_port_open(host, port, socket_stream=True, socket_timeout=None):
+    families = (socket.AF_INET, socket.AF_INET6)
+    success = False
+
+    if socket_stream:
+        socket_type = socket.SOCK_STREAM
+    else:
+        socket_type = socket.SOCK_DGRAM
+
+    for family in families:
+        try:
+            try:
+                s = socket.socket(family, socket_type)
+            except socket.error:
+                continue
+
+            if socket_timeout is not None:
+                s.settimeout(socket_timeout)
+
+            s.connect((host, port))
+            success = True
+        except socket.error, e:
+            pass
+        finally:
+            s.close()
+
+        if success:
+            return True
+
+    return False
+
+def bind_port_responder(port, socket_stream=True, socket_timeout=None, responder_data=None):
+    families = (socket.AF_INET, socket.AF_INET6)
+
+    if socket_stream:
+        socket_type = socket.SOCK_STREAM
+    else:
+        socket_type = socket.SOCK_DGRAM
+
+    host = ''   # all available interfaces
+
+    for family in families:
+        try:
+            s = socket.socket(family, socket_type)
+        except socket.error, e:
+            if family == families[-1]:  # last available family
+                raise e
+
+    if socket_timeout is not None:
+        s.settimeout(socket_timeout)
+
+    if socket_stream:
+        s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+
+    try:
+        s.bind((host, port))
+
+        if socket_stream:
+            s.listen(1)
+            connection, client_address = s.accept()
+            try:
+                if responder_data:
+                    connection.sendall(responder_data) #pylint: disable=E1101
+            finally:
+                connection.close()
+        else:
+            data, addr = s.recvfrom( 512 ) # buffer size is 1024 bytes
+
+            if responder_data:
+                s.sendto(responder_data, addr)
+    finally:
+        s.close()