/*
 *
  ***** BEGIN LICENSE BLOCK *****
 
  Copyright (C) 2009-2017 Olof Hagsand and Benny Holmgren

  This file is part of CLIXON.

  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.

  Alternatively, the contents of this file may be used under the terms of
  the GNU General Public License Version 3 or later (the "GPL"),
  in which case the provisions of the GPL are applicable instead
  of those above. If you wish to allow use of your version of this file only
  under the terms of the GPL, and not to allow others to
  use your version of this file under the terms of Apache License version 2, 
  indicate your decision by deleting the provisions above and replace them with
  the  notice and other provisions required by the GPL. If you do not delete
  the provisions above, a recipient may use your version of this file under
  the terms of any one of the Apache License version 2 or the GPL.

  ***** END LICENSE BLOCK *****

 *
 *  Code for handling netconf rpc messages
 *****************************************************************************/
#ifdef HAVE_CONFIG_H
#include "clixon_config.h" /* generated by config & autoconf */
#endif

#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <stdlib.h>
#include <errno.h>
#include <signal.h>
#include <fcntl.h>
#include <time.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <sys/param.h>
#include <assert.h>
#include <grp.h>

/* cligen */
#include <cligen/cligen.h>

/* clicon */
#include <clixon/clixon.h>

#include "clixon_netconf.h"
#include "netconf_lib.h"
#include "netconf_filter.h"
#include "netconf_plugin.h"
#include "netconf_rpc.h"

/*
 * <rpc [attributes]> 
    <!- - tag elements in a request from a client application - -> 
    </rpc> 
 */

/*! get-config help function
 * xfilter is a filter expression starting with <filter>
 * only <filter type="xpath"/> supported
 * needs refactoring: move the lower part (after xfilter) up to get-config or 
 * sub-function., focus on xfilter part here.
 * @param[in]  h       Clicon handle
 * @param[in]  xfilter Parsed xpath expression
 * @param[out] cb      Output xml stream. For reply
 * @param[out] cb_err  Error xml stream. For error reply
 * @param[in]  xorig   Original request as xml tree.
 * @param[in]  target  Database name
 * @see netconf_get_config
 * Variants of the functions where x-axis is the variants of the <filter> clause
 * and y-axis is whether a <filter><configuration> or <filter select=""> is present.
 *                  | no filter | filter subnet | filter xpath |
 * -----------------+-----------+---------------+--------------+
 * no config        |           |               |              |
 * -----------------+-----------+---------------+--------------+
 * config/select    |     -     |               |              |
 * -----------------+-----------+---------------+--------------+
 * Example requests of each:
 * no filter + no config
     <rpc><get-config><source><candidate/></source></get-config></rpc>]]>]]>
 * filter subnet + no config:
     <rpc><get-config><source><candidate/></source><filter/></get-config></rpc>]]>]]>
 * filter xpath + select all:
     <rpc><get-config><source><candidate/></source><filter type="xpath" select="/"/></get-config></rpc>]]>]]>
 * filter subtree + config:
     <rpc><get-config><source><candidate/></source><filter type="subtree"><configuration><interfaces><interface><ipv4/></interface></interfaces></configuration></filter></get-config></rpc>]]>]]>
 * filter xpath + select:
     <rpc><get-config><source><candidate/></source><filter type="xpath" select="/interfaces/interface/ipv4"/></get-config></rpc>]]>]]>
 */

/*! Variant for xmldb */
static int
netconf_filter_xmldb(clicon_handle      h, 
		     cxobj             *xfilter, 
		     enum filter_option foption,
		     cbuf              *cb, 
		     cbuf              *cb_err, 
		     cxobj             *xorig, 
		     char              *source)
{
    cxobj      *xdb = NULL; 
    cxobj      *xc; 
    cxobj      *xfilterconf = NULL; 
    int         retval = -1;
    char       *selector;

    /* Default subtree filter */
    switch (foption){
    case FILTER_SUBTREE:
	/* Get the whole database as xml */
	if (xmldb_get(h, source, "/", &xdb, NULL, NULL) < 0){
	    netconf_create_rpc_error(cb_err, xorig, 
				     "operation-failed", 
				     "application", 
				     "error", 
				     NULL,
				     "read-registry");
	    goto done;
	}

	/* Add <configuration> under <top> as reply */
	if ((xc = xml_insert(xdb, "configuration")) == NULL){
	    netconf_create_rpc_error(cb_err, xorig, 
				     "operation-failed", 
				     "application", 
				     "error", 
				     NULL,
				     "filtering");
	    goto done;
	}
	if (xfilter)
	    xfilterconf = xpath_first(xfilter, "//configuration");
	/* xml_filter removes parts of xml tree not matching */
	if (xfilterconf != NULL){ 
	    if (xml_filter(xfilterconf, xc) < 0){
		netconf_create_rpc_error(cb_err, xorig, 
					 "operation-failed", 
					 "application", 
					 "error", 
					 NULL,
					 "filtering");
		goto done;
	    }
	}
	if (xml_child_nr(xc))
	    clicon_xml2cbuf(cb, xc, 0, 1);
	break;
    case FILTER_XPATH:
	if ((selector = xml_find_value(xfilter, "select")) == NULL){
	    netconf_create_rpc_error(cb_err, xorig, 
				     "missing-attribute", 
				     "protocol", 
				     "error", 
				     NULL,
			     "<bad-attribute>select</bad-attribute>");
	    goto done;
	}
	if (xmldb_get(h, source, selector, &xdb, NULL, NULL) < 0){
	    netconf_create_rpc_error(cb_err, xorig, 
				     "operation-failed", 
				     "application", 
				     "error", 
				     NULL,
				     "read-registry");
	    goto done;
	}
	if ((xc = xml_insert(xdb, "configuration")) == NULL){
	    netconf_create_rpc_error(cb_err, xorig, 
				     "operation-failed", 
				     "application", 
				     "error", 
				     NULL,
				     "filtering");
	    goto done;
	}
	if (xml_child_nr(xc))
	    clicon_xml2cbuf(cb, xc, 0, 1);
	break;
    default:
	netconf_create_rpc_error(cb_err, xorig, 
				 "operation-failed", 
				 "application", 
				 "error", 
				 "filter type not supported",
				 "type");
	goto done;
    }
    retval = 0;
  done:
    if (xdb)
	xml_free(xdb);
    return retval; 
}

/*! Get configuration
 * @param[in]  h       Clicon handle
 * @param[in]  xorig      Sub-tree (under xorig) at <get-config>...</> level.
 * @param[out] cb      Output xml stream. For reply
 * @param[out] cb_err  Error xml stream. For error reply
 * @param[in]  xorig      Original request as xml tree.
 * @note Only filter type="xpath" is supported

    <get-config> 
        <source> 
          <candidate/> | <running/> 
        </source> 
    </get-config> 
    
    <get-config> 
        <source> 
          <candidate/> | <running/> 
        </source> 
        <filter type="subtree"> 
            <configuration> 
                <!- - tag elements for each configuration element to return - -> 
            </configuration> 
        </filter> 
    </get-config> 
 Example:
   <rpc><get-config><source><running /></source>
     <filter type="xpath" select="//SenderTwampIpv4"/>
   </get-config></rpc>]]>]]>
 */
int
netconf_get_config(clicon_handle h, 
		   cxobj        *xn, 
		   cbuf         *cb, 
		   cbuf         *cb_err, 
		   cxobj        *xorig)
{
    cxobj *xfilter; /* filter */
    int    retval = -1;
    char  *source;
    enum filter_option foption = FILTER_SUBTREE;
    char       *ftype = NULL;

    if ((source = netconf_get_target(h, xn, "source")) == NULL){
	netconf_create_rpc_error(cb_err, xorig, 
				 "missing-element", 
				 "protocol", 
				 "error", 
				 NULL,
				 "<bad-element>source</bad-element>");
	goto done;
    }
    /* ie <filter>...</filter> */
    if ((xfilter = xpath_first(xn, "filter")) != NULL) {
	if ((ftype = xml_find_value(xfilter, "type")) != NULL)
	    if (strcmp(ftype, "xpath")==0)
		foption = FILTER_XPATH;
    }
    if (netconf_filter_xmldb(h, xfilter, foption, cb, cb_err, xorig, source) < 0)
	goto done;
    retval = 0;
  done:
    return retval;
}

/*! Get options from netconf edit-config
 *  <edit-config>
 *     <config>...</config>
 *     <default-operation>(merge | none | replace)</default-operation> 
 *     <error-option>(stop-on-error | continue-on-error )</error-option> 
 *     <test-option>(set | test-then-set | test-only)</test-option> 
 *  </edit-config>
 * 
 *
 */
static int
get_edit_opts(cxobj               *xn,
	      enum operation_type *op, 
	      enum test_option    *testopt,
	      enum error_option   *erropt,
	      cbuf                *cb_err, 
	      cxobj               *xorig) 
{
    int    retval = -1;
    cxobj *x;
    char  *optstr;

    if ((x = xpath_first(xn, "default-operation")) != NULL){
	if ((optstr = xml_body(x)) != NULL){
	    if (strcmp(optstr, "replace") == 0)
		*op = OP_REPLACE;
	    else
		if (strcmp(optstr, "merge") == 0)
		    *op = OP_MERGE;
		else
		    if (strcmp(optstr, "none") == 0)
			*op = OP_NONE;
		    else{
			netconf_create_rpc_error(cb_err, xorig, 
						 "invalid-value", 
						 "protocol", 
						 "error", 
						 NULL,
						 NULL);
			goto done;
		    }
	}
    }
    if ((x = xpath_first(xn, "test-option")) != NULL){
	if ((optstr = xml_body(x)) != NULL){
	    if (strcmp(optstr, "test-then-set") == 0)
		*testopt = TEST_THEN_SET;
	    else
	    if (strcmp(optstr, "set") == 0)
		*testopt = SET;
	    else
	    if (strcmp(optstr, "test-only") == 0)
		*testopt = TEST_ONLY;
	    else{
		netconf_create_rpc_error(cb_err, xorig, 
					 "invalid-value", 
					 "protocol", 
					 "error", 
					 NULL,
					 NULL);
		goto done;
	    }
	}
    }
    if ((x = xpath_first(xn, "error-option")) != NULL){
	if ((optstr = xml_body(x)) != NULL){
	    if (strcmp(optstr, "stop-on-error") == 0)
		*erropt = STOP_ON_ERROR;
	    else
	    if (strcmp(optstr, "continue-on-error") == 0)
		*erropt = CONTINUE_ON_ERROR;
	    else{
		netconf_create_rpc_error(cb_err, xorig, 
					 "invalid-value", 
					 "protocol", 
					 "error", 
					 NULL,
					 NULL);
		goto done;
	    }
	}
    }
    retval = 0;
  done:
   return retval;
}


/*! Netconf edit configuration
  Write the change on a tmp file, then load that into candidate configuration.
    <edit-config> 
        <target> 
            <candidate/> 
        </target> 
    
    <!- - EITHER - -> 

        <config> 
            <configuration> 
                <!- - tag elements representing the data to incorporate - -> 
            </configuration> 
        </config> 

    <!- - OR - -> 
    
        <config-text> 
            <configuration-text> 
                <!- - tag elements inline configuration data in text format - -> 
            </configuration-text> 
        </config-text> 

    <!- - OR - -> 

        <url> 
            <!- - location specifier for file containing data - -> 
        </url> 
    
        <default-operation>(merge | none | replace)</default-operation> 
        <error-option>(stop-on-error | continue-on-error )</error-option> 
        <test-option>(set | test-then-set | test-only)</test-option> 
    <edit-config> 
 *
 * only 'config' supported
 * error-option: only stop-on-error supported
 * test-option:  not supported
 *
 * @note delete/remove not implemented
 *
 */
int
netconf_edit_config(clicon_handle h,
		    cxobj        *xn, 
		    cbuf         *cb, 
		    cbuf         *cb_err, 
		    cxobj        *xorig)
{
    int                 retval = -1;
    int                 ret;
    enum operation_type operation = OP_MERGE;
    enum test_option    testopt = TEST_THEN_SET;
    enum error_option   erropt = STOP_ON_ERROR;
    cxobj              *xc;       /* config */
    cxobj              *xcc;      /* child of config */
    char               *target;  /* db */
    cbuf               *cbxml = NULL;
    char               *xmlstr;

    /* must have target, and it should be candidate */
    if ((target = netconf_get_target(h, xn, "target")) == NULL ||
	strcmp(target, "candidate")){
	netconf_create_rpc_error(cb_err, xorig, 
				 "missing-element", 
				 "protocol", 
				 "error", 
				 NULL,
				 "<bad-element>target</bad-element>");
	goto done;
    }
    if (get_edit_opts(xn, &operation, &testopt, &erropt, cb_err, xorig) < 0)
	goto done;
    /* operation is OP_REPLACE, OP_MERGE, or OP_NONE pass all to backend */
    if ((xc  = xpath_first(xn, "config")) != NULL){
	/* application-specific code registers 'config' */
	if ((ret = netconf_plugin_callbacks(h, xc, cb, cb_err, xorig)) < 0){
	    netconf_create_rpc_error(cb_err, xorig, 
				     "operation-failed", 
				     "protocol", "error", 
				     NULL, "Validation"); 
	    goto done;
	}
	if ((cbxml = cbuf_new()) == NULL)
	    goto done;
	if ((xcc = xml_child_i(xc, 0)) != NULL)
	    if (clicon_xml2cbuf(cbxml, xcc, 0, 0) < 0)
		goto done;
	xmlstr = cbuf_get(cbxml);
	if (clicon_rpc_xmlput(h, target, 
			      operation,
			      "", /* api-path */
			      xmlstr) < 0){
	    netconf_create_rpc_error(cb_err, xorig, 
				     "access-denied", 
				     "protocol", 
				     "error", 
				     NULL,
				     "edit_config");
	    goto done;
	}
    }
    netconf_ok_set(1);
    retval = 0;
  done:
    if (cbxml)
	cbuf_free(cbxml);
    unchunk_group(__FUNCTION__);
    return retval;
}

/*
    <copy-config> 
        <target> 
            <candidate/> 
        </target> 
        <source> 
            <url> 
                <!- - location specifier for file containing the new configuration - -> 
            </url> 
        </source> 
    <copy-config> 
 */
int
netconf_copy_config(clicon_handle h,
		    cxobj        *xn, 
		    cbuf         *cb, 
		    cbuf         *cb_err, 
		    cxobj        *xorig)
{
    char              *source, *target; /* filenames */
    int                retval = -1;

    if ((source = netconf_get_target(h, xn, "source")) == NULL){
	netconf_create_rpc_error(cb_err, xorig, 
				 "missing-element", 
				 "protocol", 
				 "error", 
				 NULL,
				 "<bad-element>source</bad-element>");
	goto done;
    }
    if ((target = netconf_get_target(h, xn, "target")) == NULL){
	netconf_create_rpc_error(cb_err, xorig, 
				 "missing-element", 
				 "protocol", 
				 "error", 
				 NULL,
				 "<bad-element>source</bad-element>");
	goto done;
    }

#ifdef notyet
    /* If target is locked and not by this client, then return an error */
    if (target_locked(&client) > 0 && client != ce_nr){
	netconf_create_rpc_error(cb_err, xorig, 
				 "access-denied", 
				 "protocol", 
				 "error", 
				 NULL,
				 "lock");
	goto done;
    }
#endif
    if (clicon_rpc_copy(h, source, target) < 0){
	netconf_create_rpc_error(cb_err, xorig, 
				 "operation-failed", 
				 "protocol", "error", 
				 NULL, "Internal error"); 
	goto done;
    }
    netconf_ok_set(1);
    retval = 0;
  done:
    unchunk_group(__FUNCTION__);
    return retval;
}

/*! Delete configuration
  <delete-config> 
        <target> 
            <candidate/> 
        </target> 
    </delete-config> 
    Delete a configuration datastore.  The <running>
    configuration datastore cannot be deleted.
 */
int
netconf_delete_config(clicon_handle h,
		      cxobj        *xn, 
		      cbuf         *cb, 
		      cbuf         *cb_err, 
		      cxobj        *xorig)
{
    char              *target; /* filenames */
    int                retval = -1;

    if ((target = netconf_get_target(h, xn, "target")) == NULL){
	netconf_create_rpc_error(cb_err, xorig, 
				 "missing-element", 
				 "protocol", 
				 "error", 
				 NULL,
				 "<bad-element>target</bad-element>");
	goto done;
    }
    if (strcmp(target, "candidate")){
	netconf_create_rpc_error(cb_err, xorig, 
				 "bad-element", 
				 "protocol", 
				 "error", 
				 NULL,
				 "<bad-element>target</bad-element>");
	goto done;
    }
    if (clicon_rpc_change(h, "candidate",
			  OP_REMOVE, 
			  "/", "") < 0){
	netconf_create_rpc_error(cb_err, xorig, 
				 "operation-failed", 
				 "protocol", "error", 
				 NULL, "Internal error"); 
	goto done;
    }
    if (xmldb_init(h, target) < 0){
	netconf_create_rpc_error(cb_err, xorig, 
				 "operation-failed", 
				 "protocol", "error", 
				 NULL, "Internal error"); 
	goto done;
    }
    netconf_ok_set(1);
    retval = 0;
  done:
    return retval;
}

/*! Close a (user) session
    <close-session/> 
*/
int
netconf_close_session(cxobj *xn, 
		      cbuf  *cb, 
		      cbuf  *cb_err, 
		      cxobj *xorig)
{
    cc_closed++;
    netconf_ok_set(1);
    return 0;
}

/*! Lock a database
    <lock> 
        <target> 
            <candidate/> 
        </target> 
    </lock> 
    XXX
 */
int
netconf_lock(clicon_handle h,
	     cxobj        *xn, 
	     cbuf         *cb, 
	     cbuf         *cb_err, 
	     cxobj        *xorig)
{
    char *target;
    int retval = -1;

    if ((target = netconf_get_target(h, xn, "target")) == NULL){
	netconf_create_rpc_error(cb_err, xorig, 
				 "missing-element", 
				 "protocol", 
				 "error", 
				 NULL,
				 "<bad-element>source</bad-element>");
	goto done;
    }

    netconf_ok_set(1);
    retval = 0;
  done:
    return retval;
}

/*! Unlock a database
   <unlock> 
        <target> 
            <candidate/> 
        </target> 
    </unlock> 
    XXX
 */
int
netconf_unlock(clicon_handle h, 
	       cxobj *xn, 
	       cbuf *cb, cbuf *cb_err, 
	       cxobj *xorig)
{
    char *target;
    int retval = -1;

    if ((target = netconf_get_target(h, xn, "target")) == NULL){
	netconf_create_rpc_error(cb_err, xorig, 
				 "missing-element", 
				 "protocol", 
				 "error", 
				 NULL,
				 "<bad-element>target</bad-element>");
	goto done;
    }
    /* XXX notyet */
    netconf_ok_set(1);
    retval = 0;
  done:
    return retval;
}

/*! Kill other user sessions
  <kill-session> 
        <session-id>PID</session-id> 
  </kill-session> 
  XXX
 */
int
netconf_kill_session(cxobj *xn, cbuf *cb, cbuf *cb_err, cxobj *xorig)
{
#ifdef notyet
    cxobj *xsessionid;
    char *str, *ep;
    long  i;

    if ((xsessionid = xpath_first(xn, "//session-id")) == NULL){
	netconf_create_rpc_error(cb_err, xorig, 
				 "missing-element", 
				 "protocol", 
				 "error", 
				 NULL,
				 "<bad-element>session-id</bad-element>");
	return -1;
    }
    if (xml_find_value(xsessionid, "body") == NULL){
	netconf_create_rpc_error(cb_err, xorig, 
				 "missing-element", 
				 "protocol", 
				 "error", 
				 NULL,
				 "<bad-element>session-id</bad-element>");
	return -1;
    }
    if ((str = xml_find_value(xsessionid, "body")) != NULL){
	i = strtol(str, &ep, 0);
	if ((i == LONG_MIN || i == LONG_MAX) && errno)
	    return -1;
	if ((ce = find_ce_bynr(i)) == NULL){
	    netconf_create_rpc_error(cb_err, xorig, 
				     "operation-failed", 
				     "protocol", 
				     "error", 
				     NULL,
				     "No such client");
	    return -1;
	}
    }
//    ce_change_state(ce, CS_CLOSED, "Received close-session msg");
    netconf_ok_set(1);
#endif
    return 0;
}

/*! Commit candidate -> running
    <commit/> 
    :candidate
 */
int
netconf_commit(clicon_handle h,
	       cxobj        *xn, 
	       cbuf         *cb, 
	       cbuf         *cb_err, 
	       cxobj        *xorig)
{
    int                retval = -1;

    if (clicon_rpc_commit(h, "candidate", "running", 
			  0, 0) < 0){
	   netconf_create_rpc_error(cb_err, xorig, 
				    "operation-failed", 
				    "protocol", "error", 
				    NULL, "Internal error"); 
	goto done;
    }
    netconf_ok_set(1);
    retval = 0;
  done:
    unchunk_group(__FUNCTION__);
    return retval;
}

/*! Discard all changes in candidate / revert to running
    <discard-changes/> 
    :candidate
 */
int
netconf_discard_changes(clicon_handle h,
			cxobj        *xn, 
			cbuf         *cb, 
			cbuf         *cb_err, 
			cxobj        *xorig)
{
    int                retval = -1;

    if (clicon_rpc_copy(h, "running", "candidate") < 0){
	netconf_create_rpc_error(cb_err, xorig, 
				 "operation-failed", 
				 "protocol", "error", 
				 NULL, "Internal error"); 
	goto done;
    }
    netconf_ok_set(1);
    retval = 0;
  done:
    unchunk_group(__FUNCTION__);
    return retval;
}

/*! Check the semantic consistency of candidate
    <validate/> 
    :validate
 */
int
netconf_validate(clicon_handle h, 
		 cxobj        *xn, 
		 cbuf         *cb, 
		 cbuf         *cb_err, 
		 cxobj        *xorig)
{
    char *target;
    int retval = -1;

    if ((target = netconf_get_target(h, xn, "source")) == NULL){
	netconf_create_rpc_error(cb_err, xorig, 
				 "missing-element", 
				 "protocol", 
				 "error", 
				 NULL,
				 "<bad-element>target</bad-element>");
	goto done;
    }
    /* Do validation */
    netconf_ok_set(1);
    retval = 0;
  done:
    return retval;
}

/*
 * netconf_notification_cb
 * Called when a notification has happened on backend
 * and this session has registered for that event.
 * Filter it and forward it.
   <notification>
      <eventTime>2007-07-08T00:01:00Z</eventTime>
      <event xmlns="http://example.com/event/1.0">
         <eventClass>fault</eventClass>
         <reportingEntity>
             <card>Ethernet0</card>
         </reportingEntity>
         <severity>major</severity>
      </event>
   </notification>
 */
static int
netconf_notification_cb(int   s, 
			void *arg)
{
    cxobj             *xfilter = (cxobj *)arg; 
    char              *selector;
    struct clicon_msg *reply;
    int                eof;
    char              *event = NULL;
    int                level;
    int                retval = -1;
    cbuf              *cb;
    cxobj             *xe = NULL; /* event xml */
    enum clicon_msg_type type;

    if (0){
	fprintf(stderr, "%s\n", __FUNCTION__); /* debug */
	xml_print(stderr, xfilter); /* debug */
    }
    /* get msg (this is the reason this function is called) */
    if (clicon_msg_rcv(s, &reply, &eof, __FUNCTION__) < 0)
	goto done;
    /* handle close from remote end: this will exit the client */
    if (eof){
	clicon_err(OE_PROTO, ESHUTDOWN, "%s: Socket unexpected close", __FUNCTION__);
	close(s);
	errno = ESHUTDOWN;
	event_unreg_fd(s, netconf_notification_cb);
	if (xfilter)
	    xml_free(xfilter);
	goto done;
    }
    /* multiplex on message type: we only expect notify */
    type = ntohs(reply->op_type);
    switch (type){
    case CLICON_MSG_NOTIFY:
	if (clicon_msg_notify_decode(reply, &level, &event, __FUNCTION__) < 0) 
	    goto done;
	/* parse event */
	if (0){ /* XXX CLICON events are not xml */
	    if (clicon_xml_parse_string(&event, &xe) < 0)
		goto done;
	    /* find and apply filter */
	    if ((selector = xml_find_value(xfilter, "select")) == NULL)
		goto done;
	    if (xpath_first(xe, selector) == NULL) {
		fprintf(stderr, "%s no match\n", __FUNCTION__); /* debug */
		break;
	    }
	}
	/* create netconf message */
	if ((cb = cbuf_new()) == NULL){
	    clicon_err(OE_PLUGIN, errno, "%s: cbuf_new", __FUNCTION__);
	    goto done;
	}
	add_preamble(cb); /* Make it well-formed netconf xml */
	cprintf(cb, "<notification>"); 
	cprintf(cb, "<event>"); 
	cprintf(cb, "%s", event); 
	cprintf(cb, "</event>"); 
	cprintf(cb, "</notification>"); 
	add_postamble(cb);
	/* Send it to listening client on stdout */
	if (netconf_output(1, cb, "notification") < 0){
	    cbuf_free(cb);
	    goto done;
	}
	cbuf_free(cb);
	break;
    default:
	clicon_err(OE_PROTO, 0, "%s: unexpected reply: %d", 
		__FUNCTION__, type);
	goto done;
	break;
    }
    retval = 0;
  done:
    if (xe != NULL)
	xml_free(xe);
//    if (event)
//	free(event);
    unchunk_group(__FUNCTION__);
    return retval;
}

/*

    <create-subscription> 
       <stream>RESULT</stream> # If not present, events in the default NETCONF stream will be sent.
       <filter>XPATH-EXPR<(filter>
       <startTime/> # only for replay (NYI)
       <stopTime/>  # only for replay (NYI)
    </create-subscription> 
    Dont support replay
 */
static int
netconf_create_subscription(clicon_handle h, 
			    cxobj        *xn, 
			    cbuf         *cb, 
			    cbuf         *cb_err, 
			    cxobj        *xorig)
{
    cxobj           *xstream;
    cxobj           *xfilter; 
    cxobj           *xfilter2 = NULL; 
    char            *stream = NULL;
    int              s;
    char            *ftype;
    int              retval = -1;

    if ((xstream = xpath_first(xn, "//stream")) != NULL)
	stream = xml_find_value(xstream, "body");
    if (stream == NULL)
	stream = "NETCONF";
    if ((xfilter = xpath_first(xn, "//filter")) != NULL){
	if ((ftype = xml_find_value(xfilter, "type")) != NULL){
	    if (strcmp(ftype, "xpath") != 0){
		netconf_create_rpc_error(cb_err, xorig, 
					 "operation-failed", 
					 "application", 
					 "error", 
					 "only xpath filter type supported",
					 "type");
		goto done;
	    }
	}
	/* xfilter2 is applied to netconf_notification_cb below 
	   and is only freed on exit since no unreg is made.
	*/
	if ((xfilter2 = xml_dup(xfilter)) == NULL){
	    netconf_create_rpc_error(cb_err, xorig, 
				     "operation-failed", 
				     "application", 
				     "error", 
				     NULL,
				     "Internal server error");
	    goto done;
	}

    }

    if (clicon_rpc_subscription(h, 1, stream, MSG_NOTIFY_XML, "", &s) < 0){
	netconf_create_rpc_error(cb_err, xorig, 
				 "operation-failed", 
				 "application", 
				 "error", 
				 NULL,
				 "Internal protocol error");
	goto done;
    }
    if (event_reg_fd(s, netconf_notification_cb, xfilter2, "notification socket") < 0)
	goto done;
    netconf_ok_set(1);
    retval = 0;
  done:
    return retval;
}


/*! The central netconf rpc dispatcher. Look at first tag and dispach to sub-functions.
 * Call plugin handler if tag not found. If not handled by any handler, return
 * error.
 * @param[in]  h       clicon handle
 * @param[in]  xorig   Original request as xml tree.
 * @param[in]  xn      Sub-tree (under xorig) at <rpc>...</rpc> level.
 * @param[out] cb      Output xml stream. For reply
 * @param[out] cb_err  Error xml stream. For error reply
 */
int
netconf_rpc_dispatch(clicon_handle h,
		     cxobj        *xorig, 
		     cxobj        *xn, 
		     cbuf         *cb, 
		     cbuf         *cb_err)
{
    cxobj      *xe;
    int         ret = 0;
    
    xe = NULL;
    while ((xe = xml_child_each(xn, xe, CX_ELMNT)) != NULL) {
       if (strcmp(xml_name(xe), "close-session") == 0)
	   return netconf_close_session(xe, cb, cb_err, xorig);
       else
	   if (strcmp(xml_name(xe), "get-config") == 0)
	   return netconf_get_config(h, xe, cb, cb_err, xorig);
       else
	   if (strcmp(xml_name(xe), "edit-config") == 0)
	   return netconf_edit_config(h, xe, cb, cb_err, xorig);
       else
	   if (strcmp(xml_name(xe), "copy-config") == 0)
	   return netconf_copy_config(h, xe, cb, cb_err, xorig);
       else
	   if (strcmp(xml_name(xe), "delete-config") == 0)
	   return netconf_delete_config(h, xe, cb, cb_err, xorig);
       else
	   if (strcmp(xml_name(xe), "kill-session") == 0) /* TBD */
	   return netconf_kill_session(xe, cb, cb_err, xorig);
       else
	   if (strcmp(xml_name(xe), "lock") == 0) /* TBD */
	   return netconf_lock(h, xe, cb, cb_err, xorig);
       else
	   if (strcmp(xml_name(xe), "unlock") == 0) /* TBD */
	   return netconf_unlock(h, xe, cb, cb_err, xorig);
       else
	   if (strcmp(xml_name(xe), "commit") == 0)
	   return netconf_commit(h, xe, cb, cb_err, xorig);
       else
	   if (strcmp(xml_name(xe), "discard-changes") == 0)
	   return netconf_discard_changes(h, xe, cb, cb_err, xorig);
       else
	   if (strcmp(xml_name(xe), "validate") == 0)
	   return netconf_validate(h, xe, cb, cb_err, xorig);
       else
	   if (strcmp(xml_name(xe), "create-subscription") == 0)
	   return netconf_create_subscription(h, 
					      xe, cb, cb_err, xorig);
       else{
	   if ((ret = netconf_plugin_callbacks(h, 
					       xe, cb, cb_err, xorig)) < 0)
	       return -1;
	   if (ret == 0){ /* not handled by callback */
	       netconf_create_rpc_error(cb_err, xorig, 
					"operation-failed", 
					"rpc", "error", 
					xml_name(xe), "Not recognized"); 
	       ret = -1;
	   }
	   
       }
   }
    return ret;
}

/*
 * netconf_create_rpc_reply
 * Create an rpc reply msg in cb
 * Then send it using send_msg_to_client()
 */
int 
netconf_create_rpc_reply(cbuf *cb,            /* msg buffer */
			 cxobj *xr, /* orig request */
			 char *body,
			 int ok
    )
{
    cxobj *xn, *xa;

    add_preamble(cb);
    cprintf(cb, "<rpc-reply"); /* attributes from rpc */
    if (xr && (xn=xpath_first(xr, "//rpc")) != NULL){
	xa = NULL;
	while ((xa = xml_child_each(xn, xa, CX_ATTR)) != NULL) 
	    cprintf(cb, " %s=\"%s\"", xml_name(xa), xml_value(xa));
    }
    cprintf(cb, ">");
    if (ok) /* Just _maybe_ we should send data instead of ok if (if there is any)
	       even if ok is set? */
	cprintf(cb, "<ok/>");
    else{
	cprintf(cb, "<data>");
	cprintf(cb, "%s", body);
	cprintf(cb, "</data>");
    }
    cprintf(cb, "</rpc-reply>");
    add_postamble(cb);
    return 0;
}


/*
 * netconf_create_rpc_error
 * Create an rpc error msg in cb
 * (Then it should be sent at a later stage using send_msg_to_client() )
 * Arguments:
 *  cb   msg buffer to construct netconf message in
 *  xr   original request including an "rpc" tag
 *  ...  arguments to rpc-error reply message
 */
int 
netconf_create_rpc_error(cbuf *cb,            /* msg buffer */
			 cxobj *xr, /* orig request */
			 char *tag, 
			 char *type,
			 char *severity, 
			 char *message, 
			 char *info)
{
    add_error_preamble(cb, tag);
    cprintf(cb, "<rpc-reply>");
    cprintf(cb, "<rpc-error>");
    if (tag)
	cprintf(cb, "<error-tag>%s</error-tag>", tag);
    cprintf(cb, "<error-type>%s</error-type>", type);
    cprintf(cb, "<error-severity>%s</error-severity>", severity);
    if (message)
	cprintf(cb, "<error-message>%s</error-message>", message);
    if (info)
	cprintf(cb, "<error-info>%s</error-info>", info);
    cprintf(cb, "</rpc-error>");
    cprintf(cb, "</rpc-reply>");
    add_error_postamble(cb);
    return 0;
}