Pass varnishd parameters through varnishtest

Parameters are not checked and passed as is to varnishd command lines.
The parameters are prepended at the beginning of the command line to
preserve parameters needed by varnishtest or used in test cases.

bin/varnishtest/vtc_main.c

@@ -95,6 +95,7 @@ static int vtc_fail;
 static char *tmppath;
 static char *cwd = NULL;
 char *vmod_path = NULL;
+struct vsb *params_vsb = NULL;
 int leave_temp;
 int vtc_witness = 0;
 int feature_dns;
@@ -137,6 +138,7 @@ usage(void)
 	fprintf(stderr, FMT, "-L", "Always leave temporary vtc.*");
 	fprintf(stderr, FMT, "-l", "Leave temporary vtc.* if test fails");
 	fprintf(stderr, FMT, "-n iterations", "Run tests this many times");
+	fprintf(stderr, FMT, "-p name=val", "Pass a varnishd parameter");
 	fprintf(stderr, FMT, "-q", "Quiet mode: report only failures");
 	fprintf(stderr, FMT, "-t duration", "Time tests out after this long");
 	fprintf(stderr, FMT, "-v", "Verbose mode: always report test log");
@@ -487,9 +489,12 @@ main(int argc, char * const *argv)
 
 	vmod_path = NULL;
 
+	params_vsb = VSB_new_auto();
+	AN(params_vsb);
+
 	setbuf(stdout, NULL);
 	setbuf(stderr, NULL);
-	while ((ch = getopt(argc, argv, "b:D:hij:kLln:qt:vW")) != -1) {
+	while ((ch = getopt(argc, argv, "b:D:hij:kLln:p:qt:vW")) != -1) {
 		switch (ch) {
 		case 'b':
 			if (VNUM_2bytes(optarg, &bufsiz, 0)) {
@@ -529,6 +534,10 @@ main(int argc, char * const *argv)
 		case 'n':
 			ntest = strtoul(optarg, NULL, 0);
 			break;
+		case 'p':
+			VSB_printf(params_vsb, " -p ");
+			VSB_quote(params_vsb, optarg, -1, VSB_QUOTE_NONL);
+			break;
 		case 'q':
 			if (vtc_verbosity > 0)
 				vtc_verbosity--;
@@ -567,6 +576,8 @@ main(int argc, char * const *argv)
 		VTAILQ_INSERT_TAIL(&tst_head, tp, list);
 	}
 
+	VSB_finish(params_vsb);
+
 	feature_dns = dns_works();
 	ip_magic();
 

bin/varnishtest/vtc_varnish.c

@@ -55,6 +55,7 @@
 
 extern int leave_temp;
 extern char *vmod_path;
+extern struct vsb *params_vsb;
 
 struct varnish {
 	unsigned		magic;
@@ -405,6 +406,7 @@ varnish_launch(struct varnish *v)
 	VSB_printf(vsb, "cd ${pwd} &&");
 	VSB_printf(vsb, " exec varnishd %s -d -n %s",
 	    v->jail, v->workdir);
+	VSB_printf(vsb, VSB_data(params_vsb));
 	if (vtc_witness)
 		VSB_cat(vsb, " -p debug=+witness");
 	if (leave_temp)

doc/sphinx/reference/varnishtest.rst

@@ -48,6 +48,8 @@ The following options are available:
 
 -n iterations    Run tests this many times
 
+-p name=val      Pass parameters to all varnishd command lines
+
 -q               Quiet mode: report only failures
 
 -t duration      Time tests out after this long