* YANG Features

* Yang 1.1 feature and if-feature according to RFC 7950 7.20.1 and 7.20.2.
  * See https://github.com/clicon/clixon/issues/41
  * Features are declared via CLICON_FEATURE in the configuration file.
  * logical combination of features not implemented, eg if-feature "not foo or
* Identity without any identityref:s caused SEGV

CHANGELOG.md

@@ -3,6 +3,15 @@
 ## 3.8.0 (Upcoming)
 
 ### Major New features
+* YANG Features
+  * Yang 1.1 feature and if-feature according to RFC 7950 7.20.1 and 7.20.2.
+  * Features are declared via CLICON_FEATURE in the configuration file. Examples showing enabling (1) a specific feature; (2) all features in a module; (3) all features in all modules:
+```
+      <CLICON_FEATURE>ietf-routing:router-id</CLICON_FEATURE>
+      <CLICON_FEATURE>ietf-routing:*</CLICON_FEATURE>
+      <CLICON_FEATURE>*:*</CLICON_FEATURE>
+```
+  * logical combination of features not implemented, eg if-feature "not foo or bar and baz";
 * YANG Module Library support
   * According to RFC 7895 and implemented by ietf-yang-library.yang
   * Supported: module, name, revision, namespace
@@ -44,11 +53,13 @@
 
 ### Minor changes
 
+* New function: clicon_conf_xml() returns configuration tree
 * Obsoleted COMPAT_CLIV and COMPAT_XSL that were optional in 3.7
 * Added timeout option -t for clixon_netconf - quit after max time.
 * Added -l option for clixon_backend for directing syslog to stderr or stdout if running in foreground
 
 ### Corrected Bugs
+* Identity without any identityref:s caused SEGV
 * Memory error in backend transaction revert
 * Set dir /www-data with www-data as owner, see https://github.com/clicon/clixon/issues/37
 	

README.md

@@ -108,10 +108,9 @@ used to generate an interactive CLI, netconf and restconf clients. It
 also manages an XML datastore.
 
 Clixon mainly follows [YANG 1.0 RFC 6020](https://www.rfc-editor.org/rfc/rfc6020.txt) with some exceptions:
-- conformance: feature, if-feature, deviation
+- conformance: deviation
 - list features: min/max-elements, unique
 - action statements
-- notifications
 
 The aim is also to cover new features in YANG 1.1 [YANG RFC 7950](https://www.rfc-editor.org/rfc/rfc7950.txt)
 

apps/backend/backend_main.c

@@ -84,10 +84,13 @@ backend_terminate(clicon_handle h)
     yang_spec *yspec;
     char      *pidfile = clicon_backend_pidfile(h);
     char      *sockpath = clicon_sock(h);
+    cxobj     *x;
 
     clicon_debug(1, "%s", __FUNCTION__);
     if ((yspec = clicon_dbspec_yang(h)) != NULL)
 	yspec_free(yspec);
+    if ((x = clicon_conf_xml(h)) != NULL)
+	xml_free(x);
     clixon_plugin_exit(h);
     /* Delete all backend plugin RPC callbacks */
     rpc_callback_delete_all(); 

apps/backend/clixon_backend_handle.c

@@ -86,7 +86,7 @@ struct backend_handle {
     int                      bh_magic;     /* magic (HDR)*/
     clicon_hash_t           *bh_copt;      /* clicon option list (HDR) */
     clicon_hash_t           *bh_data;      /* internal clicon data (HDR) */
-    event_stream_t          *ch_stream;   /* notification streams, see clixon_stream.[ch] */
+    event_stream_t          *bh_stream;   /* notification streams, see clixon_stream.[ch] */
     
     /* ------ end of common handle ------ */
     struct client_entry     *bh_ce_list;   /* The client list */

apps/cli/cli_generate.c

@@ -232,9 +232,10 @@ yang2cli_var_sub(clicon_handle h,
 	    cprintf(cb, ">");
 	    if (helptext)
 		cprintf(cb, "(\"%s\")", helptext);
-    	    cprintf(cb, "|<%s:%s choice:", ys->ys_argument, cvtypestr);
 	    if ((ybaseref = yang_find((yang_node*)ytype, Y_BASE, NULL)) != NULL &&
 		(ybaseid = yang_find_identity(ys, ybaseref->ys_argument)) != NULL){
+		if (cvec_len(ybaseid->ys_cvec) > 0){
+		    cprintf(cb, "|<%s:%s choice:", ys->ys_argument, cvtypestr);
 		    i = 0;
 		    while ((cv = cvec_each(ybaseid->ys_cvec, cv)) != NULL){
 			if (i++)
@@ -249,6 +250,7 @@ yang2cli_var_sub(clicon_handle h,
 		}
 	    }
 	}
+    }
 
     if (options & YANG_OPTIONS_FRACTION_DIGITS)
 	cprintf(cb, " fraction-digits:%u", fraction_digits);
@@ -792,7 +794,7 @@ yang2cli(clicon_handle      h,
 	    if (yang2cli_stmt(h, ymod, cbuf, gt, 0) < 0)
 		goto done;
 	}
-    clicon_debug(1, "%s: buf\n%s\n", __FUNCTION__, cbuf_get(cbuf));
+    clicon_debug(0, "%s: buf\n%s\n", __FUNCTION__, cbuf_get(cbuf));
     /* Parse the buffer using cligen parser. XXX why this?*/
     if ((globals = cvec_new(0)) == NULL)
 	goto done;

apps/cli/cli_main.c

@@ -80,10 +80,13 @@ static int
 cli_terminate(clicon_handle h)
 {
     yang_spec  *yspec;
+    cxobj      *x;
 
     clicon_rpc_close_session(h);
     if ((yspec = clicon_dbspec_yang(h)) != NULL)
 	yspec_free(yspec);
+    if ((x = clicon_conf_xml(h)) != NULL)
+	xml_free(x);
     cli_plugin_finish(h);    
     cli_handle_exit(h);
     clicon_log_exit();

apps/netconf/netconf_main.c

@@ -270,12 +270,15 @@ static int
 netconf_terminate(clicon_handle h)
 {
     yang_spec  *yspec;
+    cxobj      *x;
     
     clixon_plugin_exit(h);
     rpc_callback_delete_all();
     clicon_rpc_close_session(h);
     if ((yspec = clicon_dbspec_yang(h)) != NULL)
 	yspec_free(yspec);
+    if ((x = clicon_conf_xml(h)) != NULL)
+	xml_free(x);
     event_exit();
     clicon_handle_exit(h);
     clicon_log_exit();

apps/restconf/restconf_main.c

@@ -446,12 +446,15 @@ static int
 restconf_terminate(clicon_handle h)
 {
     yang_spec *yspec;
+    cxobj     *x;
 
     clixon_plugin_exit(h);
     rpc_callback_delete_all();
     clicon_rpc_close_session(h);
     if ((yspec = clicon_dbspec_yang(h)) != NULL)
 	yspec_free(yspec);
+    if ((x = clicon_conf_xml(h)) != NULL)
+	xml_free(x);
     clicon_handle_exit(h);
     clicon_log_exit();
     return 0;

doc/FAQ.md

@@ -100,6 +100,19 @@ You can change where CLixon looks for the configuration FILE as follows:
   - Provide --sysconfig=<dir> when configuring then FILE is <dir>/etc/clixon.xml
   - FILE is /usr/local/etc/clixon.xml
 
+## How do I enable Yang features?
+
+Yang models have features, and parts of a specification can be
+conditional using the if-feature statement. In Clixon, features are
+enabled in the configuration file using <CLICON_FEATURE>.
+
+The example below shows enabling a specific feature; enabling all features in module; and enabling all features in all modules, respectively:
+```
+      <CLICON_FEATURE>ietf-routing:router-id</CLICON_FEATURE>
+      <CLICON_FEATURE>ietf-routing:*</CLICON_FEATURE>
+      <CLICON_FEATURE>*:*</CLICON_FEATURE>
+```
+
 ## Can I run Clixon as docker containers?
 
 Yes, the example works as docker containers as well. There should be a

example/example.xml

@@ -1,5 +1,6 @@
 <config>
   <CLICON_CONFIGFILE>/usr/local/etc/example.xml</CLICON_CONFIGFILE>
+  <CLICON_FEATURE>*:*</CLICON_FEATURE>
   <CLICON_YANG_DIR>/usr/local/share/example/yang</CLICON_YANG_DIR>
   <CLICON_YANG_MODULE_MAIN>example</CLICON_YANG_MODULE_MAIN>
   <CLICON_CLI_MODE>example</CLICON_CLI_MODE>

lib/clixon/clixon_options.h

@@ -164,6 +164,9 @@ int clicon_quiet_mode_set(clicon_handle h, int val);
 yang_spec * clicon_dbspec_yang(clicon_handle h);
 int clicon_dbspec_yang_set(clicon_handle h, struct yang_spec *ys);
 
+cxobj *clicon_conf_xml(clicon_handle h);
+int clicon_conf_xml_set(clicon_handle h, cxobj *x);
+
 plghndl_t clicon_xmldb_plugin_get(clicon_handle h);
 int clicon_xmldb_plugin_set(clicon_handle h, plghndl_t handle);
 

lib/clixon/clixon_yang.h

@@ -259,7 +259,6 @@ char      *yang_find_myprefix(yang_stmt *ys);
 int        yang_order(yang_stmt *y);
 int        yang_print(FILE *f, yang_node *yn);
 int        yang_print_cbuf(cbuf *cb, yang_node *yn, int marginal);
-int        ys_populate(yang_stmt *ys, void *arg);
 yang_stmt *yang_parse_file(int fd, const char *name, yang_spec *ysp);
 int        yang_parse(clicon_handle h, const char *filename,
 		      const char *module, const char *dir, 

lib/src/clixon_handle.c

@@ -129,13 +129,12 @@ int
 clicon_handle_exit(clicon_handle h)
 {
     struct clicon_handle *ch = handle(h);
-    clicon_hash_t        *copt;
+    clicon_hash_t        *ha;
-    clicon_hash_t        *data;
 
-    if ((copt = clicon_options(h)) != NULL)
+    if ((ha = clicon_options(h)) != NULL)
-	hash_free(copt);
+	hash_free(ha);
-    if ((data = clicon_data(h)) != NULL)
+    if ((ha = clicon_data(h)) != NULL)
-	hash_free(data);
+	hash_free(ha);
     stream_delete_all(clicon_stream(h));
     free(ch);
     return 0;

lib/src/clixon_options.c

@@ -64,8 +64,8 @@
 #include "clixon_handle.h"
 #include "clixon_log.h"
 #include "clixon_yang.h"
-#include "clixon_options.h"
 #include "clixon_xml.h"
+#include "clixon_options.h"
 #include "clixon_plugin.h"
 #include "clixon_xpath_ctx.h"
 #include "clixon_xpath.h"
@@ -116,12 +116,16 @@ clicon_option_dump(clicon_handle h,
 }
 
 /*! Read filename and set values to global options registry. XML variant.
- * @see clicon_option_readfile
+ *
+ * @param[out] xconfig Pointer to xml config tree. Should be freed by caller
+ * @retval     0       OK
+ * @retval    -1       Error
  */
 static int
-clicon_option_readfile_xml(clicon_hash_t *copt, 
+parse_configfile(clicon_handle  h,
 		 const char    *filename,
-			   yang_spec     *yspec)
+		 yang_spec     *yspec,
+		 cxobj        **xconfig)
 {
     struct stat st;
     FILE       *f = NULL;
@@ -132,6 +136,7 @@ clicon_option_readfile_xml(clicon_hash_t *copt,
     cxobj      *x = NULL;
     char       *name;
     char       *body;
+    clicon_hash_t *copt = clicon_options(h);
 
     if (filename == NULL || !strlen(filename)){
 	clicon_err(OE_UNIX, 0, "Not specified");
@@ -168,14 +173,22 @@ clicon_option_readfile_xml(clicon_hash_t *copt,
     while ((x = xml_child_each(xc, x, CX_ELMNT)) != NULL) {
 	name = xml_name(x);
 	body = xml_body(x);
-	if (name && body && 
+	if (name==NULL || body == NULL){
-	    (hash_add(copt, 
+	    clicon_log(LOG_WARNING, "%s option NULL: name:%s body:%s",
+		       __FUNCTION__, name, body);
+	    continue;
+	}
+	if (strcmp(name,"CLICON_FEATURE")==0)
+	    continue;
+	if (hash_add(copt, 
 		     name,
 		     body,
-		      strlen(body)+1)) == NULL)
+		     strlen(body)+1) == NULL)
 	    goto done;
     }
     retval = 0;
+    *xconfig = xt;
+    xt = NULL;
   done:
     if (xt)
 	xml_free(xt);
@@ -199,6 +212,7 @@ clicon_options_main(clicon_handle h)
     char          *suffix;
     char           xml = 0; /* Configfile is xml, otherwise legacy */
     yang_spec     *yspec = NULL;
+    cxobj         *xconfig = NULL;
 
     /*
      * Set configure file if not set by command-line above
@@ -213,29 +227,30 @@ clicon_options_main(clicon_handle h)
 	suffix++;
 	xml = strcmp(suffix, "xml") == 0;
     }
-    if (xml){     /* Read clixon yang file */
+    if (xml == 0){
+	clicon_err(OE_CFG, 0, "%s: suffix %s not recognized (Run ./configure --with-config-compat?)", configfile, suffix);
+	goto done;
+    }
+    /* Parse clixon yang spec */
     if ((yspec = yspec_new()) == NULL)
 	goto done;
     if (yang_parse(h, NULL, "clixon-config", CLIXON_DATADIR, NULL, yspec) < 0)
 	goto done;    
     /* Read configfile */
-	if (clicon_option_readfile_xml(copt, configfile, yspec) < 0)
+    if (parse_configfile(h, configfile, yspec, &xconfig) < 0)
 	goto done;
+    if (xml_rootchild(xconfig, 0, &xconfig) < 0)
+	goto done;
+    clicon_conf_xml_set(h, xconfig);
     /* Specific option handling */
     if (clicon_option_bool(h, "CLICON_XML_SORT") == 1)
 	xml_child_sort = 1;
     else
 	xml_child_sort = 0;
-    }
-    else {
-	clicon_err(OE_CFG, 0, "%s: suffix %s not recognized (Run ./configure --with-config-compat?)", configfile, suffix);
-	goto done;
-    }
     retval = 0;
  done:
     if (yspec) /* The clixon yang-spec is not used after this */
 	yspec_free(yspec);
-
     return retval;
 }
 
@@ -571,6 +586,38 @@ clicon_dbspec_yang_set(clicon_handle     h,
     return 0;
 }
 
+/*! Get YANG specification for Clixon system options and features
+ * Must use hash functions directly since they are not strings.
+ */
+cxobj *
+clicon_conf_xml(clicon_handle h)
+{
+    clicon_hash_t *cdat = clicon_data(h);
+    size_t         len;
+    void          *p;
+
+    if ((p = hash_value(cdat, "clixon_conf", &len)) != NULL)
+	return *(cxobj **)p;
+    return NULL;
+}
+
+/*! Set YANG specification for Clixon system options and features
+ * ys must be a malloced pointer
+ */
+int
+clicon_conf_xml_set(clicon_handle h, 
+		    cxobj        *x)
+{
+    clicon_hash_t  *cdat = clicon_data(h);
+
+    /* It is the pointer to x that should be copied by hash,
+     * so we send a ptr to the ptr to indicate what to copy.
+     */
+    if (hash_add(cdat, "clixon_conf", &x, sizeof(x)) == NULL)
+	return -1;
+    return 0;
+}
+
 /*! Get xmldb datastore plugin handle, as used by dlopen/dlsym/dlclose */
 plghndl_t
 clicon_xmldb_plugin_get(clicon_handle h)
@@ -664,7 +711,6 @@ clicon_xmldb_handle_set(clicon_handle h,
     return 0;
 }
 
-
 /*! Get authorized user name
  * @param[in]  h   Clicon handle
  * @retval     xh  XMLDB storage handle. If not connected return NULL

lib/src/clixon_proto_client.c

@@ -61,8 +61,8 @@
 #include "clixon_handle.h"
 #include "clixon_log.h"
 #include "clixon_yang.h"
-#include "clixon_options.h"
 #include "clixon_xml.h"
+#include "clixon_options.h"
 #include "clixon_plugin.h"
 #include "clixon_string.h"
 #include "clixon_xpath_ctx.h"

lib/src/clixon_xml_map.c

@@ -80,8 +80,8 @@
 #include "clixon_string.h"
 #include "clixon_yang.h"
 #include "clixon_yang_type.h"
-#include "clixon_options.h"
 #include "clixon_xml.h"
+#include "clixon_options.h"
 #include "clixon_plugin.h"
 #include "clixon_xpath_ctx.h"
 #include "clixon_xpath.h"

lib/src/clixon_yang.c

@@ -672,6 +672,10 @@ yang_find_topnode(yang_spec *ysp,
  * @param[in]  ys        Yang statement
  * @retval     NULL      Not found
  * @retval     prefix    Prefix as char* pointer into yang tree
+ * @code
+ * char *myprefix;
+ * myprefix = yang_find_myprefix(ys);
+ * @endcode
  */
 char *
 yang_find_myprefix(yang_stmt *ys)
@@ -862,6 +866,15 @@ yarg_prefix(yang_stmt *ys)
  * @param[out] id      Malloced identifier.
  * @retval     0       OK
  * @retval    -1       Error
+ * @code
+ *    char      *prefix = NULL;
+ *    char      *id = NULL;
+ *    if (yang_nodeid_split(nodeid, &prefix, &id) < 0)
+ *	 goto done;
+ *    if (prefix)
+ *	 free(prefix);
+ *    if (id)
+ *	 free(id);
  * @note caller need to free id and prefix after use
  */
 int
@@ -1284,11 +1297,11 @@ ys_populate_type(yang_stmt *ys,
  * Do this recursively
  * @param[in] ys   The yang identity to populate.
  * @param[in] arg  If set contains a derived identifier
- * @see validate_identityref  which in runtime validates actual valoues
+ * @see validate_identityref  which in runtime validates actual values
  */
 static int
 ys_populate_identity(yang_stmt *ys, 
-		     void      *arg)
+		     char      *idref)
 {
     int             retval = -1;
     yang_stmt      *yc = NULL;
@@ -1298,7 +1311,6 @@ ys_populate_identity(yang_stmt *ys,
     char           *baseid;
     char           *prefix = NULL;
     cbuf           *cb = NULL;
-    char           *idref = (char*)arg;
     char           *p;
 
     if (idref == NULL){
@@ -1358,31 +1370,91 @@ ys_populate_identity(yang_stmt *ys,
     return retval;
 }
 
+/*! Populate yang feature statement - set cv to 1 if enabled
+ *
+ * @param[in] ys   Feature yang statement to populate.
+ * @param[in] h    Clicon handle
+ */
+static int
+ys_populate_feature(clicon_handle h,
+		    yang_stmt    *ys)
+{
+    int        retval = -1;
+    cxobj     *x;
+    yang_stmt *ymod;
+    int        found = 0;
+    cg_var    *cv;
+    char      *module;
+    char      *feature;
+    cxobj     *x1;
+
+    /* Eg, when parsing the config xml itself */
+    if ((x = clicon_conf_xml(h)) == NULL)
+	goto ok;
+    if ((ymod = ys_module(ys)) == NULL){
+	clicon_err(OE_YANG, 0, "module not found"); 
+	goto done;
+    }
+    module = ymod->ys_argument;
+    feature = ys->ys_argument;
+    x1 = NULL;
+    while ((x1 = xml_child_each(x, x1, CX_ELMNT)) != NULL && found == 0) {
+	char *m = NULL;
+	char *f = NULL;
+	if (strcmp(xml_name(x1), "CLICON_FEATURE") != 0)
+	    continue;
+	/* get m and f from configuration feature rules */
+	if (yang_nodeid_split(xml_body(x1), &m, &f) < 0)
+	    goto done;
+	if (m && f &&
+	    (strcmp(m,"*")==0 ||
+	     strcmp(m, module)==0) &&
+	    (strcmp(f,"*")==0 ||
+	     strcmp(f, feature)==0))
+	    found = 1;
+	if (m) free(m);
+	if (f) free(f);
+    }
+    if ((cv = cv_new(CGV_BOOL)) == NULL){
+	clicon_err(OE_YANG, errno, "cv_new"); 
+	goto done;
+    }
+    cv_name_set(cv, feature);
+    cv_bool_set(cv, found);
+    clicon_debug(1, "%s %s:%s %d", __FUNCTION__, module, feature, found);
+    ys->ys_cv = cv;
+ ok:
+    retval = 0;
+ done:
+    return retval;
+}
+
 /*! Populate with cligen-variables, default values, etc. Sanity checks on complete tree.
  *
  * We do this in 2nd pass after complete parsing to be sure to have a complete parse-tree
  * See ys_parse_sub for first pass and what can be assumed
  * After this pass, cv:s are set for LEAFs and LEAF-LISTs
  */
-int
+static int
 ys_populate(yang_stmt *ys, 
 	    void      *arg)
 {
     int retval = -1;
+    //    clicon_handle h = (clicon_handle)arg;
     
     switch(ys->ys_keyword){
     case Y_LEAF:
     case Y_LEAF_LIST:
-	if (ys_populate_leaf(ys, arg) < 0)
+	if (ys_populate_leaf(ys, NULL) < 0)
 	    goto done;
 	break;
     case Y_LIST:
-	if (ys_populate_list(ys, arg) < 0)
+	if (ys_populate_list(ys, NULL) < 0)
 	    goto done;
 	break;
     case Y_RANGE: 
     case Y_LENGTH: 
-	if (ys_populate_range(ys, arg) < 0)
+	if (ys_populate_range(ys, NULL) < 0)
 	    goto done;
 	break;
     case Y_MANDATORY: /* call yang_mandatory() to check if set */
@@ -1391,11 +1463,11 @@ ys_populate(yang_stmt *ys,
 	    goto done;
 	break;
     case Y_TYPE:
-	if (ys_populate_type(ys, arg) < 0)
+	if (ys_populate_type(ys, NULL) < 0)
 	    goto done;
 	break;
     case Y_IDENTITY:
-	if (ys_populate_identity(ys, arg) < 0)
+	if (ys_populate_identity(ys, NULL) < 0)
 	    goto done;
 	break;
     default:
@@ -1406,7 +1478,6 @@ ys_populate(yang_stmt *ys,
     return retval;
 }
 
-
 /*! Resolve a grouping name from a point in the yang tree 
  * @retval  0  OK, but ygrouping determines if a grouping was resolved or not
  * @retval -1  Error, with clicon_err called
@@ -1852,6 +1923,8 @@ yang_parse_module(const char   *module,
     if ((ymod = yang_parse_filename(cbuf_get(fbuf), ysp)) == NULL)
 	goto done;
   done:
+    if (fbuf)
+	cbuf_free(fbuf);
     return ymod; /* top-level (sub)module */
 }
 
@@ -1894,7 +1967,7 @@ yang_parse_recurse(yang_stmt    *ymod,
 	    subrevision = yrev->ys_argument;
 	else
 	    subrevision = NULL;
-	if (yang_find((yang_node*)ysp, Y_MODULE, submodule) == NULL)
+	if (yang_find((yang_node*)ysp, Y_MODULE, submodule) == NULL){
 	    /* recursive call */
 	    if ((subymod = yang_parse_module(submodule, dir, subrevision, ysp)) == NULL)
 		goto done;
@@ -1903,6 +1976,7 @@ yang_parse_recurse(yang_stmt    *ymod,
 		goto done;
 	    }
 	}
+    }
     retval = 0;
   done:  
     return retval; /* top-level (sub)module */
@@ -1951,6 +2025,83 @@ ys_schemanode_check(yang_stmt *ys,
     return retval;
 }
 
+/*! Find feature and if-feature nodes, check features and remove disabled nodes
+ * @retval -1  Error
+ * @retval  0  Feature not enabled: remove yt
+ * @retval  1  OK
+ * @note On return 1 the over-lying function need to remove yt from its parent
+ * @note cannot use yang_apply here since child-list is modified (destructive) 
+ */
+static int
+yang_features(clicon_handle h,
+	      yang_stmt    *yt)
+{
+    int        retval = -1;
+    int        i;
+    int        j;
+    yang_stmt *ys = NULL;
+    char       *prefix = NULL;
+    char       *feature = NULL;
+    yang_stmt  *ymod;  /* module yang node */
+    yang_stmt  *yfeat; /* feature yang node */
+
+    i = 0;
+    while (i<yt->ys_len){ /* Note, children may be removed */
+	ys = yt->ys_stmt[i];
+	if (ys->ys_keyword == Y_IF_FEATURE){
+	    if (yang_nodeid_split(ys->ys_argument, &prefix, &feature) < 0)
+		goto done;
+	    /* Specifically need to handle? strcmp(prefix, myprefix)) */
+	    if (prefix == NULL)
+		ymod = ys_module(ys);
+	    else
+		ymod = yang_find_module_by_prefix(yt, prefix);
+
+	    /* Check if feature exists, and is set, otherwise remove */
+	    if ((yfeat = yang_find((yang_node*)ymod, Y_FEATURE, feature)) == NULL ||
+		yfeat->ys_cv == NULL || !cv_bool_get(yfeat->ys_cv)){
+		retval = 0; /* feature not enabled */
+		goto done;
+	    }
+	    if (prefix){
+		free(prefix);
+		prefix = NULL;
+	    }
+	    if (feature){
+		free(feature);
+		feature = NULL;
+	    }
+	}
+	else
+	    if (ys->ys_keyword == Y_FEATURE){
+		if (ys_populate_feature(h, ys) < 0)
+		    goto done;
+	    } else switch (yang_features(h, ys)){
+	    case -1: /* error */
+		goto done;
+		break;
+	    case 0: /* disabled: remove ys */
+		for (j=i+1; j<yt->ys_len; j++)
+		    yt->ys_stmt[j-1] = yt->ys_stmt[j];
+		yt->ys_len--;
+		yt->ys_stmt[yt->ys_len] = NULL;
+		ys_free(ys);
+		continue; /* Don't increment i */
+		break;
+	    default: /* ok */
+		break;
+	    }
+	i++;
+    }
+    retval = 1;
+ done:
+    if (prefix)
+	free(prefix);
+    if (feature)
+	free(feature);
+    return retval;
+}
+
 /*! Parse top yang module including all its sub-modules. Expand and populate yang tree
  *
  * @param[in] h        CLICON handle
@@ -2001,12 +2152,18 @@ yang_parse(clicon_handle h,
     if (yang_parse_recurse(ymod, dir, ysp) < 0)
 	goto done;
 
-    /* Step 2: Go through parse tree and populate it with cv types */
+    /* Step 2: check features: check if enabled and remove disabled features */
-    for (i=modnr; i<ysp->yp_len; i++)
+    for (i=modnr; i<ysp->yp_len; i++) /* XXX */
-	if (yang_apply((yang_node*)ysp->yp_stmt[i], -1, ys_populate, NULL) < 0)
+	if (yang_features(h, ysp->yp_stmt[i]) < 0)
 	    goto done;
     
-    /* Step 3: Resolve all types: populate type caches. Requires eg length/range cvecs
+    /* Step 3: Go through parse tree and populate it with cv types */
+    for (i=modnr; i<ysp->yp_len; i++)
+	if (yang_apply((yang_node*)ysp->yp_stmt[i], -1, ys_populate, (void*)h) < 0)
+	    goto done;
+
+
+    /* Step 4: Resolve all types: populate type caches. Requires eg length/range cvecs
      * from ys_populate step
      */
     for (i=modnr; i<ysp->yp_len; i++)
@@ -2017,18 +2174,18 @@ yang_parse(clicon_handle h,
        grouping/uses and unfold all macros into a single tree as they are used.
     */
 
-    /* Step 4: Macro expansion of all grouping/uses pairs. Expansion needs marking */
+    /* Step 5: Macro expansion of all grouping/uses pairs. Expansion needs marking */
     for (i=modnr; i<ysp->yp_len; i++){
 	if (yang_expand((yang_node*)ysp->yp_stmt[i]) < 0)
 	    goto done;
 	yang_apply((yang_node*)ysp->yp_stmt[i], -1, ys_flag_reset, (void*)YANG_FLAG_MARK);
     }
 
-    /* Step 4: Top-level augmentation of all modules XXX: only new modules? */
+    /* Step 6: Top-level augmentation of all modules XXX: only new modules? */
     if (yang_augment_spec(ysp) < 0)
 	goto done;
 
-    /* sanity check of schemanode references, need more here */
+    /* Step 7: sanity check of schemanode references, need more here */
     for (i=modnr; i<ysp->yp_len; i++)
 	if (yang_apply((yang_node*)ysp->yp_stmt[i], -1, ys_schemanode_check, NULL) < 0)
 	    goto done;
@@ -2486,11 +2643,8 @@ yang_spec_parse_module(clicon_handle h,
 	clicon_err(OE_YANG, EINVAL, "yang dir not set");
 	goto done;
     }
-    if (yang_parse(h, NULL, module, dir, revision, yspec) < 0){
+    if (yang_parse(h, NULL, module, dir, revision, yspec) < 0)
-	yspec_free(yspec);
-	yspec = NULL;
 	goto done;
-    }
     retval = 0;
   done:
     return retval;
@@ -2521,11 +2675,8 @@ yang_spec_parse_file(clicon_handle h,
 	clicon_err(OE_YANG, EINVAL, "yang dir not set");
 	goto done;
     }
-    if (yang_parse(h, filename, NULL, dir, NULL, yspec) < 0){
+    if (yang_parse(h, filename, NULL, dir, NULL, yspec) < 0)
-	yspec_free(yspec);
-	yspec = NULL;
 	goto done;
-    }
     retval = 0;
   done:
     return retval;

test/test_cli.sh

@@ -42,7 +42,6 @@ sudo $clixon_backend -s init -f $cfg
 if [ $? -ne 0 ]; then
     err
 fi
-new "cli tests"
 
 new "cli configure top"
 expectfn "$clixon_cli -1 -f $cfg set interfaces" 0 "^$"

test/test_event.sh

@@ -131,4 +131,4 @@ if [ -n "$pid" ]; then
     sudo kill $pid
 fi
 
-#rm -rf $dir
+rm -rf $dir

yang/clixon-config@2018-04-30.yang

@@ -117,6 +117,16 @@ module clixon-config {
 	}
     }
     container config {
+       leaf-list CLICON_FEATURE {
+           description
+               "Supported features as used by YANG feature/if-feature
+	        value is: <module>:<feature>, where <module> and <feature>
+                are either names, or the special character '*'.
+                *:an* means enable all features
+                <module>:* means enable all features in the specified module
+                *:<feature> means enable the specific feature in all modules";
+	   type string;
+        }
 	leaf CLICON_CONFIGFILE{
 	    type string;
 	    description