Detect when libevent cannot parse resolv.conf

Issue:		#17
Reported by:	Florian Schaefer

main.t.c

@@ -78,6 +78,7 @@ Suite * sys_suite(void);
 Suite * base64_suite(void);
 Suite * url_suite(void);
 Suite * util_suite(void);
+Suite * pxythrmgr_suite(void);
 
 int
 main(UNUSED int argc, UNUSED char *argv[])
@@ -100,6 +101,7 @@ main(UNUSED int argc, UNUSED char *argv[])
 	srunner_add_suite(sr, base64_suite());
 	srunner_add_suite(sr, url_suite());
 	srunner_add_suite(sr, util_suite());
+	srunner_add_suite(sr, pxythrmgr_suite());
 	srunner_run_all(sr, CK_NORMAL);
 	nfail = srunner_ntests_failed(sr);
 	srunner_free(sr);

proxy.c

@@ -280,6 +280,8 @@ proxy_new(opts_t *opts)
 {
 	proxy_listener_ctx_t *head;
 	proxy_ctx_t *ctx;
+	struct evdns_base *dnsbase;
+	int rc;
 
 	/* adds locking, only required if accessed from separate threads */
 	evthread_use_pthreads();
@@ -304,6 +306,28 @@ proxy_new(opts_t *opts)
 		goto leave1;
 	}
 
+	/* create a dnsbase here purely for being able to test parsing
+	 * resolv.conf while we can still alert the user about it. */
+	dnsbase = evdns_base_new(ctx->evbase, 0);
+	if (!dnsbase) {
+		log_err_printf("Error creating dns event base\n");
+		goto leave1b;
+	}
+	rc = evdns_base_resolv_conf_parse(dnsbase, DNS_OPTIONS_ALL,
+	                                  "/etc/resolv.conf");
+	evdns_base_free(dnsbase, 0);
+	if (rc != 0) {
+		log_err_printf("evdns cannot parse resolv.conf: %s (%d)\n",
+		               rc == 1 ? "failed to open file" :
+		               rc == 2 ? "failed to stat file" :
+		               rc == 3 ? "file too large" :
+		               rc == 4 ? "out of memory" :
+		               rc == 5 ? "short read from file" :
+		               rc == 6 ? "no nameservers listed in file" :
+		               "unknown error", rc);
+		goto leave1b;
+	}
+
 	if (OPTS_DEBUG(opts)) {
 		proxy_debug_base(ctx->evbase);
 	}

pxythrmgr.t.c

@@ -0,0 +1,111 @@
+/*
+ * SSLsplit - transparent and scalable SSL/TLS interception
+ * Copyright (c) 2009-2014, Daniel Roethlisberger <daniel@roe.ch>
+ * All rights reserved.
+ * http://www.roe.ch/SSLsplit
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice unmodified, this list of conditions, and the following
+ *    disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "pxythrmgr.h"
+
+#include <string.h>
+
+#include <check.h>
+
+// evdns_base_resolv_conf_parse(base, DNS_OPTIONS_ALL, "/etc/resolv.conf");
+
+START_TEST(pxythrmgr_libevent_01)
+{
+	struct event_base *evbase;
+
+	evbase = event_base_new();
+	fail_unless(!!evbase, "no event base");
+	event_base_free(evbase);
+}
+END_TEST
+
+START_TEST(pxythrmgr_libevent_02)
+{
+	struct event_base *evbase;
+	struct evdns_base *dnsbase;
+
+	evbase = event_base_new();
+	fail_unless(!!evbase, "no event base");
+	dnsbase = evdns_base_new(evbase, 0);
+	fail_unless(!!dnsbase, "no evdns base");
+	evdns_base_free(dnsbase, 0);
+	event_base_free(evbase);
+}
+END_TEST
+
+START_TEST(pxythrmgr_libevent_03)
+{
+	struct event_base *evbase;
+	struct evdns_base *dnsbase;
+	int rc;
+
+	evbase = event_base_new();
+	fail_unless(!!evbase, "no event base");
+	dnsbase = evdns_base_new(evbase, 0);
+	fail_unless(!!dnsbase, "no evdns base");
+	rc = evdns_base_resolv_conf_parse(dnsbase, DNS_OPTIONS_ALL,
+	                                  "/etc/resolv.conf");
+	fail_unless(rc == 0, "unable to parse resolv.conf");
+	evdns_base_free(dnsbase, 0);
+	event_base_free(evbase);
+}
+END_TEST
+
+START_TEST(pxythrmgr_libevent_04)
+{
+	struct event_base *evbase;
+	struct evdns_base *dnsbase;
+
+	evbase = event_base_new();
+	fail_unless(!!evbase, "no event base");
+	dnsbase = evdns_base_new(evbase, 1);
+	fail_unless(!!dnsbase, "no evdns base");
+	evdns_base_free(dnsbase, 0);
+	event_base_free(evbase);
+}
+END_TEST
+
+Suite *
+pxythrmgr_suite(void)
+{
+	Suite *s;
+	TCase *tc;
+
+	s = suite_create("pxythrmgr");
+
+	tc = tcase_create("pxythrmgr_libevent");
+	tcase_add_test(tc, pxythrmgr_libevent_01);
+	tcase_add_test(tc, pxythrmgr_libevent_02);
+	tcase_add_test(tc, pxythrmgr_libevent_03);
+	tcase_add_test(tc, pxythrmgr_libevent_04);
+	suite_add_tcase(s, tc);
+
+	return s;
+}
+
+/* vim: set noet ft=c: */