Support union with are same subtypes with SNMP

apps/snmp/snmp_lib.c

@@ -155,10 +155,61 @@ static const map_str2str yang_snmp_types[] = {
     {"uint16",  "uint32"},
     { NULL,    NULL} /* if not found */
 };
-char* yang_type_to_snmp(char* yang_type)
+
+ /* A function that checks that all subtypes of the union are the same
+ * @param[in]  ytype Yang resolved type (a union in this case)
+ * @param[out] cb    Buffer where type of subtypes is written
+ * @retval     1 - true(All subtypes are the same)
+ * @retval     0 - false
+ */
+int is_same_subtypes_union(yang_stmt *ytype, cbuf *cb)
+{
+    int        retval = 0;
+    yang_stmt *y_sub_type = NULL;
+    yang_stmt *y_resolved_type = NULL;        /* resolved type */
+    char      *resolved_type_str;             /* resolved type */
+    char      *type_str = NULL;
+
+    int          options = 0;
+    cvec        *cvv = NULL;
+    cvec        *patterns = NULL;
+    uint8_t      fraction_digits = 0;
+
+    /* Loop over all sub-types in the resolved union type, note these are
+     * not resolved types (unless they are built-in, but the resolve call is
+     * made in the union_one call.
+     */
+    while ((y_sub_type = yn_each(ytype, y_sub_type)) != NULL){
+        if (yang_keyword_get(y_sub_type) != Y_TYPE)
+            continue;
+
+        if (yang_type_resolve(ytype, ytype, y_sub_type,
+                          &y_resolved_type, &options,
+                          &cvv, patterns, NULL, &fraction_digits) < 0 || ( NULL == y_resolved_type) )
+            break;
+        if( (NULL == (resolved_type_str = yang_argument_get(y_resolved_type))) )
+            break;
+        if( NULL == type_str || strcmp(type_str, resolved_type_str) == 0)
+            type_str = resolved_type_str;
+        else
+            break;
+    }
+    if (NULL == y_sub_type && NULL != type_str){
+        cbuf_append_str(cb, resolved_type_str);
+        retval = 1;
+    }
+    return retval;
+}
+char* yang_type_to_snmp(yang_stmt *ytype, char* yang_type_str)
 {
-    char* ret = clicon_str2str(yang_snmp_types, yang_type);
-    return (NULL == ret) ? yang_type : ret;
+    char* type_str = yang_type_str;
+    if (yang_type_str && strcmp(yang_type_str, "union") == 0){
+        cbuf *cb = cbuf_new();
+        if (is_same_subtypes_union(ytype, cb) > 0)
+            type_str =  cbuf_get(cb);
+    }
+    char* ret = clicon_str2str(yang_snmp_types, type_str);
+    return (NULL == ret) ? type_str : ret;
 }
 
 /*! Translate from snmp string to int representation
@@ -296,7 +347,7 @@ snmp_yang_type_get(yang_stmt  *ys,
     if (yang_type_get(ys, &origtype, &yrestype, NULL, NULL, NULL, NULL, NULL) < 0)
         goto done;
     restype = yrestype?yang_argument_get(yrestype):NULL;
-    restype = yang_type_to_snmp(restype);
+    restype = yang_type_to_snmp(yrestype, restype);
     if (strcmp(restype, "leafref")==0){
         if ((ypath = yang_find(yrestype, Y_PATH, NULL)) == NULL){
             clicon_err(OE_YANG, 0, "No path in leafref");

test/test_snmp_union.sh

@@ -0,0 +1,186 @@
+#!/usr/bin/env bash
+# SNMP test for yang union type with are same types of subtypes.
+
+# Magic line must be first in script (see README.md)
+s="$_" ; . ./lib.sh || if [ "$s" = $0 ]; then exit 0; else return 0; fi
+
+# Re-use main example backend state callbacks
+APPNAME=example
+
+if [ ${ENABLE_NETSNMP} != "yes" ]; then
+    echo "Skipping test, Net-SNMP support not enabled."
+    rm -rf $dir
+    if [ "$s" = $0 ]; then exit 0; else return 0; fi
+fi
+
+cfg=$dir/conf_startup.xml
+fyang=$dir/clixon-example.yang
+fstate=$dir/state.xml
+
+# AgentX unix socket
+SOCK=/var/run/snmp.sock
+
+# Relies on example_backend.so for $fstate file handling
+
+cat <<EOF > $cfg
+<clixon-config xmlns="http://clicon.org/config">
+  <CLICON_CONFIGFILE>$cfg</CLICON_CONFIGFILE>
+  <CLICON_YANG_DIR>${YANG_INSTALLDIR}</CLICON_YANG_DIR>
+  <CLICON_YANG_DIR>${YANG_STANDARD_DIR}</CLICON_YANG_DIR>
+  <CLICON_YANG_DIR>${MIB_GENERATED_YANG_DIR}</CLICON_YANG_DIR>
+  <CLICON_YANG_MAIN_FILE>$fyang</CLICON_YANG_MAIN_FILE>
+  <CLICON_SOCK>$dir/$APPNAME.sock</CLICON_SOCK>
+  <CLICON_BACKEND_DIR>/usr/local/lib/$APPNAME/backend</CLICON_BACKEND_DIR>
+  <CLICON_BACKEND_PIDFILE>/var/tmp/$APPNAME.pidfile</CLICON_BACKEND_PIDFILE>
+  <CLICON_XMLDB_DIR>$dir</CLICON_XMLDB_DIR>
+  <CLICON_SNMP_AGENT_SOCK>unix:$SOCK</CLICON_SNMP_AGENT_SOCK>
+  <CLICON_SNMP_MIB>clixon-example</CLICON_SNMP_MIB>
+  <CLICON_VALIDATE_STATE_XML>true</CLICON_VALIDATE_STATE_XML>
+</clixon-config>
+EOF
+
+cat <<EOF > $fyang
+module clixon-example{
+  yang-version 1.1;
+  namespace "urn:example:clixon";
+  prefix ex;
+  import ietf-yang-smiv2 {
+    prefix smiv2;
+  }
+  /* Generic config data */
+    container table{
+        smiv2:oid "1.3.6.1.2.1.47.1.1.1";
+        list parameter{
+            smiv2:oid "1.3.6.1.2.1.47.1.1.1.1";
+            key Index;
+
+            leaf Index{
+                type int32;
+                smiv2:oid "1.3.6.1.2.1.47.1.1.1.1.1";
+                smiv2:max-access "read-only";
+            }
+            leaf Union_exm{
+                description "Union with same subtypes";
+                config false;
+                type union
+                {
+                    type int32;
+                    type int32; 
+                }                
+                smiv2:oid "1.3.6.1.2.1.47.1.1.1.1.2";
+                smiv2:max-access "read-only";
+            }
+        }
+    }
+}
+EOF
+
+# This is state data written to file that backend reads from (on request)
+# integer and string have values, sleeper does not and uses default (=1)
+
+cat <<EOF > $fstate
+   <table xmlns="urn:example:clixon">
+     <parameter>
+       <Index>2</Index>
+       <Union_exm>4</Union_exm>
+     </parameter>
+     <parameter>
+       <Index>12</Index>
+       <Union_exm>14</Union_exm>
+     </parameter>
+   </table>
+EOF
+
+function testinit(){
+    new "test params: -s init -f $cfg -- -sS $fstate"
+    if [ $BE -ne 0 ]; then
+    # Kill old backend and start a new one
+    new "kill old backend"
+    sudo clixon_backend -zf $cfg
+    if [ $? -ne 0 ]; then
+        err "Failed to start backend"
+    fi
+
+    sudo pkill -f clixon_backend
+
+    new "Starting backend"
+    start_backend -s init -f $cfg -- -sS $fstate
+    fi
+
+    new "wait backend"
+    wait_backend
+
+    if [ $SN -ne 0 ]; then
+        # Kill old clixon_snmp, if any
+        new "Terminating any old clixon_snmp processes"
+        sudo killall -q clixon_snmp
+
+        new "Starting clixon_snmp"
+        start_snmp $cfg &
+    fi
+
+    new "wait snmp"
+    wait_snmp
+}
+
+function testexit(){
+    stop_snmp
+
+    if [ $BE -ne 0 ]; then
+        new "Kill backend"
+        # Check if premature kill
+        pid=$(pgrep -u root -f clixon_backend)
+        if [ -z "$pid" ]; then
+            err "backend already dead"
+        fi
+        # kill backend
+        stop_backend -f $cfg
+    fi
+}
+
+ENTITY_OID=".1.3.6.1.2.1.47.1.1.1"
+
+# name, value=2
+OID1="${ENTITY_OID}.1.1.2"
+# name, value=12
+OID2="${ENTITY_OID}.1.1.12"
+# value, value=2
+OID3="${ENTITY_OID}.1.2.2"
+# value, value=12
+OID4="${ENTITY_OID}.1.2.12"
+# stat, value=2
+OIDX="${ENTITY_OID}.1.3.2"
+# stat, value=12
+OIDY="${ENTITY_OID}.1.3.12"
+
+
+new "SNMP system tests"
+testinit
+
+new "Get index, $OID1"
+validate_oid $OID1 $OID1 "INTEGER" "2"
+
+new "Get next $OID1"
+validate_oid $OID1 $OID2 "INTEGER" "12"
+
+new "Get index, $OID2"
+validate_oid $OID2 $OID2 "INTEGER" "12"
+new "Get next $OID2"
+validate_oid $OID2 $OID3 "INTEGER" "4"
+
+new "Get index, $OID3"
+validate_oid $OID3 $OID3 "INTEGER" "4"
+
+new "Get next $OID4"
+validate_oid $OID3 $OID4 "INTEGER" "14"
+
+new "Get index, $OID4"
+validate_oid $OID4 $OID4 "INTEGER" "14"
+
+new "Cleaning up"
+testexit
+
+rm -rf $dir
+
+new "endtest"
+endtest