Added example for tables.

apps/snmp/snmp_main.c

@@ -73,6 +73,140 @@ static oid      my_data_ulong_instance[4] = { 1, 2, 3, 9 };
 
 u_long          my_ulong = 42;
 
+static netsnmp_table_data_set *table_set;
+
+/*
+ * https://net-snmp.sourceforge.io/dev/agent/data_set_8c-example.html#_a0
+ */
+void
+init_testtable(void)
+{
+    netsnmp_table_row *row;
+
+    /*
+     * the OID we want to register our integer at.  This should be the
+     * * OID node for the entire table.  In our case this is the
+     * * netSnmpIETFWGTable oid definition
+     */
+    oid             my_registration_oid[] =
+        { 1, 3, 6, 1, 4, 1, 8072, 2, 2, 1 };
+
+    /*
+     * a debugging statement.  Run the agent with -Dexample_data_set to see
+     * * the output of this debugging statement.
+     */
+    DEBUGMSGTL(("example_data_set",
+                "Initalizing example dataset table\n"));
+
+    /*
+     * It's going to be the "working group chairs" table, since I'm
+     * * sitting at an IETF convention while I'm writing this.
+     * *
+     * *  column 1 = index = string = WG name
+     * *  column 2 = string = chair #1
+     * *  column 3 = string = chair #2  (most WGs have 2 chairs now)
+     */
+
+    table_set = netsnmp_create_table_data_set("netSnmpIETFWGTable");
+
+    /*
+     * allow the creation of new rows via SNMP SETs
+     */
+    table_set->allow_creation = 1;
+
+    /*
+     * set up what a row "should" look like, starting with the index
+     */
+    netsnmp_table_dataset_add_index(table_set, ASN_OCTET_STR);
+
+    /*
+     * define what the columns should look like.  both are octet strings here
+     */
+    netsnmp_table_set_multi_add_default_row(table_set,
+                                            /*
+                                             * column 2 = OCTET STRING,
+                                             * writable = 1,
+                                             * default value = NULL,
+                                             * default value len = 0
+                                             */
+                                            2, ASN_OCTET_STR, 1, NULL, 0,
+                                            /*
+                                             * similar
+                                             */
+                                            3, ASN_OCTET_STR, 1, NULL, 0,
+                                            0 /* done */ );
+
+    /*
+     * register the table
+     */
+    /*
+     * if we wanted to handle specific data in a specific way, or note
+     * * when requests came in we could change the NULL below to a valid
+     * * handler method in which we could over ride the default
+     * * behaviour of the table_dataset helper
+     */
+    netsnmp_register_table_data_set(netsnmp_create_handler_registration
+                                    ("netSnmpIETFWGTable", NULL,
+                                     my_registration_oid,
+                                     OID_LENGTH(my_registration_oid),
+                                     HANDLER_CAN_RWRITE), table_set, NULL);
+
+
+    /*
+     * create the a row for the table, and add the data
+     */
+    row = netsnmp_create_table_data_row();
+    /*
+     * set the index to the IETF WG name "snmpv3"
+     */
+    netsnmp_table_row_add_index(row, ASN_OCTET_STR, "snmpv3",
+                                strlen("snmpv3"));
+
+
+    /*
+     * set column 2 to be the WG chair name "Russ Mundy"
+     */
+    netsnmp_set_row_column(row, 2, ASN_OCTET_STR,
+                           "Russ Mundy", strlen("Russ Mundy"));
+    netsnmp_mark_row_column_writable(row, 2, 1);        /* make writable via SETs */
+
+    /*
+     * set column 3 to be the WG chair name "David Harrington"
+     */
+    netsnmp_set_row_column(row, 3, ASN_OCTET_STR, "David Harrington",
+                           strlen("David Harrington"));
+    netsnmp_mark_row_column_writable(row, 3, 1);        /* make writable via SETs */
+
+    /*
+     * add the row to the table
+     */
+    netsnmp_table_dataset_add_row(table_set, row);
+
+    /*
+     * add the data, for the second row
+     */
+    row = netsnmp_create_table_data_row();
+    netsnmp_table_row_add_index(row, ASN_OCTET_STR, "snmpconf",
+                                strlen("snmpconf"));
+    netsnmp_set_row_column(row, 2, ASN_OCTET_STR, "David Partain",
+                           strlen("David Partain"));
+    netsnmp_mark_row_column_writable(row, 2, 1);        /* make writable */
+    netsnmp_set_row_column(row, 3, ASN_OCTET_STR, "Jon Saperia",
+                           strlen("Jon Saperia"));
+    netsnmp_mark_row_column_writable(row, 3, 1);        /* make writable */
+    netsnmp_table_dataset_add_row(table_set, row);
+
+    /*
+     * Finally, this actually allows the "add_row" token it the
+     * * snmpd.conf file to add rows to this table.
+     * * Example snmpd.conf line:
+     * *   add_row netSnmpIETFWGTable eos "Glenn Waters" "Dale Francisco"
+     */
+    netsnmp_register_auto_data_table(table_set, NULL);
+
+    DEBUGMSGTL(("example_data_set", "Done initializing.\n"));
+}
+
 void
 init_testhandler(void)
 {
@@ -572,6 +706,7 @@ clixon_snmp_init(clicon_handle h,
     /* XXX Hardcoded, replace this with generic MIB */
 #if 1
     init_testhandler();
+    init_testtable();
 #else
     init_nstAgentSubagentObject(h);
 #endif