automake: introduce make check

Automake supports using 'make check' to execute so-called unit tests.  These
are used to do basic sanity checking of the code (prove that it works, etc).

This commit introduces an initial user which checks the OID string printed
by the mgmt-addr print routine.

The test will fail at this point (because there is a bug in the OID print
routine).

Signed-off-by: Aaron Conole <aconole@redhat.com>

Makefile.am

@@ -1,6 +1,9 @@
 # target programs to be installed in ${sbindir}
 sbin_PROGRAMS = lldpad dcbtool lldptool vdptool
 
+check_PROGRAMS = lldp_clif_test
+TESTS = $(check_PROGRAMS)
+
 # package nltest and vdptest, but do not install it anywhere
 if BUILD_DEBUG
 noinst_PROGRAMS = nltest vdptest qbg22sim
@@ -142,3 +145,7 @@ bashcompletiondir = $(sysconfdir)/bash_completion.d
 dist_bashcompletion_DATA = contrib/bash_completion/lldpad contrib/bash_completion/lldptool
 
 AM_DISTCHECK_CONFIGURE_FLAGS = --enable-debug
+
+lldp_clif_test_SOURCES = test/lldp_clif_test.c lldp_basman_clif.c lldp_util.c \
+	lldp_rtnl.c
+lldp_clif_test_LDFLAGS = -lrt $(LIBNL_LIBS)

README

@@ -186,7 +186,9 @@ lldpad Application Install
    lldpad will create the lldpad.conf file if it does not exist.
 
    For development purposes, 'lldpad' can be run directly from the build 
-   directory.
+   directory.  To run the unit tests associated with openlldpd, execute:
+
+     ./bootstrap.sh; ./configure; make check
 
 Options
 -------

test/lldp_clif_test.c

@@ -0,0 +1,140 @@
+/*******************************************************************************
+  SPDX-Identifier: GPL-2.0-or-later
+
+  LLDP Agent Daemon (LLDPAD) Software - clif unit tests
+  Copyright (C) 2018, Red Hat, Inc.
+
+  This program is free software; you can redistribute it and/or modify it
+  under the terms and conditions of the GNU General Public License,
+  version 2, as published by the Free Software Foundation.
+
+  This program is distributed in the hope it will be useful, but WITHOUT
+  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+  more details.
+
+  You should have received a copy of the GNU General Public License along with
+  this program; if not, write to the Free Software Foundation, Inc.,
+  51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
+
+  The full GNU General Public License is included in this distribution in
+  the file called "COPYING".
+
+  Contact Information:
+  open-lldp Mailing List <lldp-devel@open-lldp.org>
+
+*******************************************************************************/
+
+#include "lldp.h"
+
+#include <fcntl.h>
+#include <signal.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+/* functions to test */
+extern void print_mng_addr(u16 len, char *info);
+
+/* tests for output functions */
+static int hook_fd = -1;
+static FILE *stdout_hook;
+static char *test_name;
+
+static void hook_stdout(char *test_id)
+{
+	if (!test_id)
+		test_name = "test_tmp.txt";
+
+	if (hook_fd == -1) {
+		hook_fd = dup(STDOUT_FILENO);
+		stdout_hook = freopen(test_id, "w", stdout);
+		test_name = strdup(test_id);
+
+		if (!stdout_hook || !test_name) {
+			fprintf(stderr, "Fatal error: unable to hook stdout\n");
+			exit(1);
+		}
+	}
+}
+
+static void unhook_stdout()
+{
+	if (hook_fd != -1) {
+		dup2(hook_fd, STDOUT_FILENO);
+		stdout = fdopen(STDOUT_FILENO, "w");
+		close(hook_fd);
+		hook_fd = -1;
+
+		unlink(test_name);
+		free(test_name);
+		test_name = NULL;
+	}
+}
+
+static int test_mgmt_printing()
+{
+	char *mgmt_info_test;
+	int result = 1;
+	FILE *output;
+	int ctr = 0;
+
+	mgmt_info_test =
+		"05010a2ff8f9" /* addrlen + subtype + addr */
+		"0100000000" /* if-subtype + ifnum */
+		"0c0103060102011f0101010100"; /* oid-len + oid */
+
+	/* start by hooking the stdout filedescriptor */
+	hook_stdout("test_mgmt_printing.txt");
+
+	print_mng_addr(strlen(mgmt_info_test), mgmt_info_test);
+
+	fflush(stdout);
+
+	output = fopen("test_mgmt_printing.txt", "r");
+	if (!output)
+		goto done;
+
+	while (!feof(output) && ctr != 3) {
+		char buf[1024];
+		if (!fgets(buf, sizeof(buf), output))
+			goto done;
+
+		if (!strcmp(buf, "IPv4: 10.47.248.249\n"))
+			ctr++;
+		else if (!strcmp(buf, "\tUnknown interface subtype: 0\n"))
+			ctr++;
+		else if (!strcmp(buf, "\tOID: 0.1.3.6.1.2.1.31.1.1.1.1.0\n"))
+			ctr++;
+		else {
+			fprintf(stderr, "FATAL: unknown line '%s'\n", buf);
+			goto done;
+		}
+	}
+	result = 0;
+
+done:
+	if (output)
+		fclose(output);
+
+	unhook_stdout();
+	return result;
+}
+
+int main(void)
+{
+	int error_counter = 0;
+
+	error_counter += test_mgmt_printing();
+
+	return error_counter ? -1 : 0;
+}
+
+/* Local Variables:    */
+/* c-indent-level: 8   */
+/* c-basic-offset: 8   */
+/* tab-width: 8        */
+/* indent-tabs-mode: t */
+/* End:                */