Added basic rfc8527 support

Added basic rfc8527 support, but without support for:
 * ds:operational
 * with-origin
 * clixon/test/test_rfc8527_*.sh

The current level of rfc8527 support is intended to allow commit
operations on the 'candidate' datastore without rewriting the 'startup'
datastore.

apps/restconf/restconf_lib.h

@@ -56,6 +56,18 @@ enum restconf_media{
 };
 typedef enum restconf_media restconf_media;
 
+/* @See https://tools.ietf.org/html/rfc8342, ietf-datastores@2018-02-14.yang */
+enum ietf_ds {
+    IETF_DS_NONE        = 0,
+    IETF_DS_RUNNING,
+    IETF_DS_CANDIDATE,
+    IETF_DS_STARTUP,
+    IETF_DS_INTENDED,
+    IETF_DS_DYNAMIC,
+    IETF_DS_OPERATIONAL
+};
+typedef enum ietf_ds ietf_ds_t;
+
 /*
  * Prototypes
  */

apps/restconf/restconf_methods.c

@@ -230,6 +230,7 @@ match_list_keys(yang_stmt *y,
  * PUT:   If it does not, set op to create, otherwise replace
  * PATCH: If it does not, fail, otherwise replace/merge
  * @param[in] plain_patch  fail if object does not exists AND merge (not replace)
+ * @param[in]  ds       0 if "data" resource, 1 if rfc8527 "ds" resource
  */ 
 static int
 api_data_write(clicon_handle h,
@@ -242,7 +243,8 @@ api_data_write(clicon_handle h,
 	       int           pretty,
 	       restconf_media media_in,
 	       restconf_media media_out,
-	       int            plain_patch)
+	       int            plain_patch,
+	       ietf_ds_t      ds)
 {
     int            retval = -1;
     enum operation_type op;
@@ -596,12 +598,12 @@ api_data_write(clicon_handle h,
 	    NETCONF_BASE_NAMESPACE); /* bind nc to netconf namespace */
     cprintf(cbx, "<edit-config");
     /* RFC8040 Sec 1.4:
-     * If the NETCONF server supports :startup, the RESTCONF server MUST
+     * If this is a "data" request and the NETCONF server supports :startup,
-     * automatically update the non-volatile startup configuration
+     * the RESTCONF server MUST automatically update the non-volatile startup
-     * datastore, after the "running" datastore has been altered as a
+     * configuration datastore, after the "running" datastore has been altered
-     * consequence of a RESTCONF edit operation.
+     * as a consequence of a RESTCONF edit operation.
      */
-    if (if_feature(yspec, "ietf-netconf", "startup"))
+    if ((IETF_DS_NONE == ds) && if_feature(yspec, "ietf-netconf", "startup"))
 	cprintf(cbx, " copystartup=\"true\"");
     cprintf(cbx, " autocommit=\"true\"");
     cprintf(cbx, "><target><candidate /></target>");
@@ -695,13 +697,14 @@ api_data_put(clicon_handle h,
 	     cvec         *qvec, 
 	     char         *data,
 	     int           pretty,
-	     restconf_media media_out)
+	     restconf_media media_out,
+	     ietf_ds_t     ds)
 {
     restconf_media media_in;
 
     media_in = restconf_content_type(h);
     return api_data_write(h, req, api_path0, pcvec, pi, qvec, data, pretty,
-			  media_in, media_out, 0);
+			  media_in, media_out, 0, ds);
 } 
 
 /*! Generic REST PATCH method for plain patch 
@@ -730,7 +733,8 @@ api_data_patch(clicon_handle h,
 	       cvec         *qvec, 
 	       char         *data,
 	       int           pretty,
-	       restconf_media media_out)
+	       restconf_media media_out,
+	       ietf_ds_t     ds)
 {
     restconf_media media_in;
     int ret;
@@ -740,7 +744,7 @@ api_data_patch(clicon_handle h,
     case YANG_DATA_XML:
     case YANG_DATA_JSON: 	/* plain patch */
 	ret = api_data_write(h, req, api_path0, pcvec, pi, qvec, data, pretty,
-			     media_in, media_out, 1);
+			     media_in, media_out, 1, ds);
 	break;
     case YANG_PATCH_XML:
     case YANG_PATCH_JSON: 	/* RFC 8072 patch */
@@ -760,6 +764,7 @@ api_data_patch(clicon_handle h,
  * @param[in]  pi       Offset, where path starts
  * @param[in]  pretty   Set to 1 for pretty-printed xml/json output
  * @param[in]  media_out Output media
+ * @param[in]  ds       0 if "data" resource, 1 if rfc8527 "ds" resource
  * See RFC 8040 Sec 4.7
  * Example:
  *  curl -X DELETE http://127.0.0.1/restconf/data/interfaces/interface=eth0
@@ -771,7 +776,8 @@ api_data_delete(clicon_handle h,
 		char         *api_path,
 		int           pi,
 		int           pretty,
-		restconf_media media_out)
+		restconf_media media_out,
+		ietf_ds_t     ds)
 {
     int        retval = -1;
     int        i;
@@ -834,12 +840,12 @@ api_data_delete(clicon_handle h,
 
     cprintf(cbx, "<edit-config");
     /* RFC8040 Sec 1.4:
-     * If the NETCONF server supports :startup, the RESTCONF server MUST
+     * If this is a "data" request and the NETCONF server supports :startup,
-     * automatically update the non-volatile startup configuration
+     * the RESTCONF server MUST automatically update the non-volatile startup
-     * datastore, after the "running" datastore has been altered as a
+     * configuration datastore, after the "running" datastore has been altered
-     * consequence of a RESTCONF edit operation.
+     * as a consequence of a RESTCONF edit operation.
      */
-    if (if_feature(yspec, "ietf-netconf", "startup"))
+    if ((IETF_DS_NONE == ds) && if_feature(yspec, "ietf-netconf", "startup"))
 	cprintf(cbx, " copystartup=\"true\"");
     cprintf(cbx, " autocommit=\"true\"");
     cprintf(cbx, "><target><candidate /></target>");

apps/restconf/restconf_methods.h

@@ -46,14 +46,14 @@ int api_data_options(clicon_handle h, void *req);
 int api_data_put(clicon_handle h, void *req, char *api_path, 
 		 cvec *pcvec, int pi, 
 		 cvec *qvec, char *data,
-		 int pretty, restconf_media media_out);
+		 int pretty, restconf_media media_out, ietf_ds_t ds);
 
 int api_data_patch(clicon_handle h, void *req, char *api_path, 
 		   cvec *pcvec, int pi, 
 		   cvec *qvec, char *data, int pretty,
-		   restconf_media media_out);
+		   restconf_media media_out, ietf_ds_t ds);
 
 int api_data_delete(clicon_handle h, void *req, char *api_path, int pi,
-		    int pretty, restconf_media media_out);
+		    int pretty, restconf_media media_out, ietf_ds_t ds);
 
 #endif /* _RESTCONF_METHODS_H_ */

apps/restconf/restconf_methods_get.c

@@ -363,7 +363,8 @@ api_data_head(clicon_handle h,
 	      int           pi,
 	      cvec         *qvec,
 	      int           pretty,
-	      restconf_media media_out)
+	      restconf_media media_out,
+	      ietf_ds_t     ds)
 {
     return api_data_get2(h, req, api_path, pcvec, pi, qvec, pretty, media_out, 1);
 }
@@ -402,7 +403,8 @@ api_data_get(clicon_handle h,
              int           pi,
              cvec         *qvec,
 	     int           pretty,
-	     restconf_media media_out)
+	     restconf_media media_out,
+	     ietf_ds_t     ds)
 {
     return api_data_get2(h, req, api_path, pcvec, pi, qvec, pretty, media_out, 0);
 }

apps/restconf/restconf_methods_get.h

@@ -42,9 +42,9 @@
  * Prototypes
  */
 int api_data_head(clicon_handle h, void *req, char *api_path, cvec *pcvec, int pi, 
-		  cvec *qvec, int pretty, restconf_media media_out);
+		  cvec *qvec, int pretty, restconf_media media_out, ietf_ds_t ds);
 int api_data_get(clicon_handle h, void *req, char *api_path, cvec *pcvec, int pi, 
-		 cvec *qvec, int pretty, restconf_media media_out);
+		 cvec *qvec, int pretty, restconf_media media_out, ietf_ds_t ds);
 int api_operations_get(clicon_handle h, void *req, 
 		       char *api_path, int pi, cvec *qvec, char *data,
 		       int pretty, restconf_media media_out);

apps/restconf/restconf_methods_post.c

@@ -152,7 +152,8 @@ api_data_post(clicon_handle h,
 	      cvec         *qvec, 
 	      char         *data,
 	      int           pretty,
-	      restconf_media media_out)
+	      restconf_media media_out,
+	      ietf_ds_t     ds)
 {
     int            retval = -1;
     enum operation_type op = OP_CREATE;
@@ -377,12 +378,12 @@ api_data_post(clicon_handle h,
 
     cprintf(cbx, "<edit-config");
     /* RFC8040 Sec 1.4:
-     * If the NETCONF server supports :startup, the RESTCONF server MUST
+     * If this is a "data" request and the NETCONF server supports :startup,
-     * automatically update the non-volatile startup configuration
+     * the RESTCONF server MUST automatically update the non-volatile startup
-     * datastore, after the "running" datastore has been altered as a
+     * configuration datastore, after the "running" datastore has been altered
-     * consequence of a RESTCONF edit operation.
+     * as a consequence of a RESTCONF edit operation.
      */
-    if (if_feature(yspec, "ietf-netconf", "startup"))
+    if ((IETF_DS_NONE == ds) && if_feature(yspec, "ietf-netconf", "startup"))
 	cprintf(cbx, " copystartup=\"true\"");
     cprintf(cbx, " autocommit=\"true\"");
     cprintf(cbx, "><target><candidate /></target>");

apps/restconf/restconf_methods_post.h

@@ -44,7 +44,7 @@
 int api_data_post(clicon_handle h, void *req, char *api_path,
 		  int pi, cvec *qvec, char *data,
 		  int pretty,
-		  restconf_media media_out);
+		  restconf_media media_out, ietf_ds_t ds);
 
 int api_operations_post(clicon_handle h, void *req, char *api_path,
 			int pi,	cvec *qvec, char *data,

apps/restconf/restconf_root.c

@@ -153,7 +153,8 @@ api_root_restconf_exact(clicon_handle  h,
 	goto done;
     
     if (clixon_xml_parse_string("<restconf xmlns=\"urn:ietf:params:xml:ns:yang:ietf-restconf\"><data/>"
-				"<operations/><yang-library-version>2016-06-21</yang-library-version></restconf>",
+				"<operations/><yang-library-version>" IETF_YANG_LIBRARY_REVISION
+				"</yang-library-version></restconf>",
 				YB_MODULE, yspec, &xt, NULL) < 0)
 	goto done;
 
@@ -187,6 +188,24 @@ api_root_restconf_exact(clicon_handle  h,
     return retval;
 }
 
+/** A stub implementation of the operational state datastore. The full
+ * implementation is required by https://tools.ietf.org/html/rfc8527#section-3.1
+ */
+static int
+api_operational_state(clicon_handle  h,
+			void          *req,
+			char          *request_method,
+			int            pretty,
+			restconf_media media_out)
+
+{
+    clicon_debug(1, "%s request method:%s", __FUNCTION__, request_method);
+
+    /* We are not implementing this method at this time, 20201105 despite it
+     * being mandatory https://tools.ietf.org/html/rfc8527#section-3.1 */
+    return restconf_notimplemented(req);
+}
+
 /*!
  * See https://tools.ietf.org/html/rfc7895
  */
@@ -200,7 +219,6 @@ api_yang_library_version(clicon_handle h,
     int    retval = -1;
     cxobj *xt = NULL;
     cbuf  *cb = NULL;
-    char  *ietf_yang_library_revision = "2016-06-21"; /* XXX */
 
     clicon_debug(1, "%s", __FUNCTION__);
     if (restconf_reply_header(req, "Content-Type", "%s", restconf_media_int2str(media_out)) < 0)
@@ -209,7 +227,7 @@ api_yang_library_version(clicon_handle h,
 	goto done;
     if (clixon_xml_parse_va(YB_NONE, NULL, &xt, NULL,
 			    "<yang-library-version>%s</yang-library-version>",
-			    ietf_yang_library_revision) < 0)
+			    IETF_YANG_LIBRARY_REVISION) < 0)
 	goto done;
     if (xml_rootchild(xt, 0, &xt) < 0)
 	goto done;
@@ -250,6 +268,7 @@ api_yang_library_version(clicon_handle h,
  * @param[in]  pretty Set to 1 for pretty-printed xml/json output
  * @param[in]  media_in  Input media
  * @param[in]  media_out Output media
+ * @param[in]  ds       0 if "data" resource, 1 if rfc8527 "ds" resource
  */
 static int
 api_data(clicon_handle h,
@@ -260,28 +279,58 @@ api_data(clicon_handle h,
 	 cvec         *qvec, 
 	 char         *data,
 	 int           pretty,
-	 restconf_media media_out)
+	 restconf_media media_out,
+	 ietf_ds_t     ds)
 {
     int     retval = -1;
+    int     read_only = 0, dynamic = 0;
     char   *request_method;
 
     clicon_debug(1, "%s", __FUNCTION__);
     request_method = restconf_param_get(h, "REQUEST_METHOD");
     clicon_debug(1, "%s method:%s", __FUNCTION__, request_method);
+
+    /* https://tools.ietf.org/html/rfc8527#section-3.2 */
+    /* We assume that dynamic datastores are read only at this time 20201105 */
+    if (IETF_DS_DYNAMIC == ds)
+	    dynamic = 1;
+    if ((IETF_DS_INTENDED == ds) || (IETF_DS_RUNNING == ds)
+            || (IETF_DS_DYNAMIC == ds) || (IETF_DS_OPERATIONAL == ds)) {
+	read_only = 1;
+    }
+
     if (strcmp(request_method, "OPTIONS")==0)
 	retval = api_data_options(h, req);
-    else if (strcmp(request_method, "HEAD")==0)
+    else if (strcmp(request_method, "HEAD")==0) {
-	retval = api_data_head(h, req, api_path, pcvec, pi, qvec, pretty, media_out);
+	if (dynamic) {
-    else if (strcmp(request_method, "GET")==0)
+            retval = restconf_method_notallowed(req, "GET,POST");
-	retval = api_data_get(h, req, api_path, pcvec, pi, qvec, pretty, media_out);
+	}
-    else if (strcmp(request_method, "POST")==0)
+	retval = api_data_head(h, req, api_path, pcvec, pi, qvec, pretty, media_out, ds);
-	retval = api_data_post(h, req, api_path, pi, qvec, data, pretty, media_out);
+    }
-    else if (strcmp(request_method, "PUT")==0)
+    else if (strcmp(request_method, "GET")==0) {
-	retval = api_data_put(h, req, api_path, pcvec, pi, qvec, data, pretty, media_out);
+	retval = api_data_get(h, req, api_path, pcvec, pi, qvec, pretty, media_out, ds);
-    else if (strcmp(request_method, "PATCH")==0)
+    }
-	retval = api_data_patch(h, req, api_path, pcvec, pi, qvec, data, pretty, media_out);
+    else if (strcmp(request_method, "POST")==0) {
-    else if (strcmp(request_method, "DELETE")==0)
+	retval = api_data_post(h, req, api_path, pi, qvec, data, pretty, media_out, ds);
-	retval = api_data_delete(h, req, api_path, pi, pretty, media_out);
+    }
+    else if (strcmp(request_method, "PUT")==0) {
+	if (read_only) {
+            retval = restconf_method_notallowed(req, "GET,POST");
+	}
+	retval = api_data_put(h, req, api_path, pcvec, pi, qvec, data, pretty, media_out, ds);
+    }
+    else if (strcmp(request_method, "PATCH")==0) {
+	if (read_only) {
+            retval = restconf_method_notallowed(req, "GET,POST");
+	}
+	retval = api_data_patch(h, req, api_path, pcvec, pi, qvec, data, pretty, media_out, ds);
+    }
+    else if (strcmp(request_method, "DELETE")==0) {
+	if (read_only) {
+            retval = restconf_method_notallowed(req, "GET,POST");
+	}
+	retval = api_data_delete(h, req, api_path, pi, pretty, media_out, ds);
+    }
     else
 	retval = restconf_notfound(h, req);
     clicon_debug(1, "%s retval:%d", __FUNCTION__, retval);
@@ -441,7 +490,41 @@ api_root_restconf(clicon_handle h,
     }
     else if (strcmp(api_resource, "data") == 0){ /* restconf, skip /api/data */
 	if (api_data(h, req, path, pcvec, 2, qvec, indata,
-		     pretty, media_out) < 0)
+		     pretty, media_out, IETF_DS_NONE) < 0)
+	    goto done;
+    }
+    else if (strcmp(api_resource, "ds") == 0) {
+	/* We should really be getting the supported datastore types from the
+	 * application model, but at this time the datastore model of startup/
+	 * running/cadidate is hardcoded into the clixon implementation. 20201104 */
+	ietf_ds_t ds = IETF_DS_NONE;
+
+	if (4 > pn) { /* Malformed request, no "ietf-datastores:<datastore>" component */
+           restconf_notfound(h, req);
+	   goto done;
+        }
+
+	/* Assign ds; See https://tools.ietf.org/html/rfc8342#section-7 */
+	if      (0 == strcmp(pvec[3], "ietf-datastores:running"))
+	    ds = IETF_DS_RUNNING;
+        else if (0 == strcmp(pvec[3], "ietf-datastores:candidate"))
+	    ds = IETF_DS_CANDIDATE;
+        else if (0 == strcmp(pvec[3], "ietf-datastores:startup"))
+	    ds = IETF_DS_STARTUP;
+        else if (0 == strcmp(pvec[3], "ietf-datastores:operational")) {
+            /* See https://tools.ietf.org/html/rfc8527#section-3.1
+	     *     https://tools.ietf.org/html/rfc8342#section-5.3 */
+	    if (0 > api_operational_state(h, req, request_method, pretty, media_out)) {
+                goto done;
+            }
+	    goto ok;
+        }
+        else { /* Malformed request, unsupported datastore type */
+           restconf_notfound(h, req);
+	   goto done;
+	}
+	/* ds is assigned at this point */
+	if (0 > api_data(h, req, path, pcvec, 3, qvec, indata, pretty, media_out, ds))
 	    goto done;
     }
     else if (strcmp(api_resource, "operations") == 0){ /* rpc */

apps/restconf/restconf_root.h

@@ -42,6 +42,7 @@
  * Constants
  */
 #define RESTCONF_API       "restconf"
+#define IETF_YANG_LIBRARY_REVISION    "2019-01-04"
 
 /* RESTCONF enables deployments to specify where the RESTCONF API is 
    located.  The client discovers this by getting the "/.well-known/host-meta"