[PATCH 2/3] conf: Detect vhost-user mode earlier

[David Gibson <david@gibson.dropbear.id.au>]

We detect our operating mode in conf_mode(), unless we're using vhost-user
mode, in which case we change it later when we parse the --vhost-user
option.  That means we need to delay parsing the --repair-path option (for
vhost-user only) until still later.

However, there are many other places in the main option parsing loop which
also rely on mode.  We get away with those, because they happen to be able
to treat passt and vhost-user modes identically.  This is potentially
confusing, though.  So, move setting of MODE_VU into conf_mode() so
c->mode always has its final value from that point onwards.

To match, we move the parsing of --repair-path back into the main option
parsing loop.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---
 conf.c | 43 ++++++++++++++++++++++++++-----------------
 1 file changed, 26 insertions(+), 17 deletions(-)

diff --git a/conf.c b/conf.c
index 11bf1202..b26249a8 100644
--- a/conf.c
+++ b/conf.c
@@ -998,10 +998,23 @@ pasta_opts:
  *
  * Return: mode to operate in, PASTA or PASST
  */
-/* cppcheck-suppress constParameter */
 enum passt_modes conf_mode(int argc, char *argv[])
 {
+	int vhost_user = 0;
+	const struct option optvu[] = {
+		{"vhost-user",	no_argument,		&vhost_user,	1 },
+		{ 0 },
+	};
 	char argv0[PATH_MAX], *basearg0;
+	int name;
+
+	optind = 0;
+	do {
+		name = getopt_long(argc, argv, "-:", optvu, NULL);
+	} while (name != -1);
+
+	if (vhost_user)
+		return MODE_VU;
 
 	if (argc < 1)
 		die("Cannot determine argv[0]");
@@ -1607,9 +1620,8 @@ void conf(struct ctx *c, int argc, char **argv)
 
 			die("Invalid host nameserver address: %s", optarg);
 		case 25:
-			if (c->mode == MODE_PASTA)
-				die("--vhost-user is for passt mode only");
-			c->mode = MODE_VU;
+			/* Already handled in conf_mode() */
+			ASSERT(c->mode == MODE_VU);
 			break;
 		case 26:
 			vu_print_capabilities();
@@ -1620,7 +1632,14 @@ void conf(struct ctx *c, int argc, char **argv)
 				die("Invalid FQDN: %s", optarg);
 			break;
 		case 28:
-			/* Handle this once we checked --vhost-user */
+			if (c->mode != MODE_VU && strcmp(optarg, "none"))
+				die("--repair-path is for vhost-user mode only");
+
+			if (snprintf_check(c->repair_path,
+					   sizeof(c->repair_path), "%s",
+					   optarg))
+				die("Invalid passt-repair path: %s", optarg);
+
 			break;
 		case 'd':
 			c->debug = 1;
@@ -1897,8 +1916,8 @@ void conf(struct ctx *c, int argc, char **argv)
 	if (c->ifi4 && IN4_IS_ADDR_UNSPECIFIED(&c->ip4.guest_gw))
 		c->no_dhcp = 1;
 
-	/* Inbound port options, DNS, and --repair-path can be parsed now, after
-	 * IPv4/IPv6 settings and --vhost-user.
+	/* Inbound port options and DNS can be parsed now, after IPv4/IPv6
+	 * settings
 	 */
 	fwd_probe_ephemeral();
 	udp_portmap_clear();
@@ -1944,16 +1963,6 @@ void conf(struct ctx *c, int argc, char **argv)
 			}
 
 			die("Cannot use DNS address %s", optarg);
-		} else if (name == 28) {
-			if (c->mode != MODE_VU && strcmp(optarg, "none"))
-				die("--repair-path is for vhost-user mode only");
-
-			if (snprintf_check(c->repair_path,
-					   sizeof(c->repair_path), "%s",
-					   optarg))
-				die("Invalid passt-repair path: %s", optarg);
-
-			break;
 		}
 	} while (name != -1);
 
-- 
@@ -998,10 +998,23 @@ pasta_opts:
  *
  * Return: mode to operate in, PASTA or PASST
  */
-/* cppcheck-suppress constParameter */
 enum passt_modes conf_mode(int argc, char *argv[])
 {
+	int vhost_user = 0;
+	const struct option optvu[] = {
+		{"vhost-user",	no_argument,		&vhost_user,	1 },
+		{ 0 },
+	};
 	char argv0[PATH_MAX], *basearg0;
+	int name;
+
+	optind = 0;
+	do {
+		name = getopt_long(argc, argv, "-:", optvu, NULL);
+	} while (name != -1);
+
+	if (vhost_user)
+		return MODE_VU;
 
 	if (argc < 1)
 		die("Cannot determine argv[0]");
@@ -1607,9 +1620,8 @@ void conf(struct ctx *c, int argc, char **argv)
 
 			die("Invalid host nameserver address: %s", optarg);
 		case 25:
-			if (c->mode == MODE_PASTA)
-				die("--vhost-user is for passt mode only");
-			c->mode = MODE_VU;
+			/* Already handled in conf_mode() */
+			ASSERT(c->mode == MODE_VU);
 			break;
 		case 26:
 			vu_print_capabilities();
@@ -1620,7 +1632,14 @@ void conf(struct ctx *c, int argc, char **argv)
 				die("Invalid FQDN: %s", optarg);
 			break;
 		case 28:
-			/* Handle this once we checked --vhost-user */
+			if (c->mode != MODE_VU && strcmp(optarg, "none"))
+				die("--repair-path is for vhost-user mode only");
+
+			if (snprintf_check(c->repair_path,
+					   sizeof(c->repair_path), "%s",
+					   optarg))
+				die("Invalid passt-repair path: %s", optarg);
+
 			break;
 		case 'd':
 			c->debug = 1;
@@ -1897,8 +1916,8 @@ void conf(struct ctx *c, int argc, char **argv)
 	if (c->ifi4 && IN4_IS_ADDR_UNSPECIFIED(&c->ip4.guest_gw))
 		c->no_dhcp = 1;
 
-	/* Inbound port options, DNS, and --repair-path can be parsed now, after
-	 * IPv4/IPv6 settings and --vhost-user.
+	/* Inbound port options and DNS can be parsed now, after IPv4/IPv6
+	 * settings
 	 */
 	fwd_probe_ephemeral();
 	udp_portmap_clear();
@@ -1944,16 +1963,6 @@ void conf(struct ctx *c, int argc, char **argv)
 			}
 
 			die("Cannot use DNS address %s", optarg);
-		} else if (name == 28) {
-			if (c->mode != MODE_VU && strcmp(optarg, "none"))
-				die("--repair-path is for vhost-user mode only");
-
-			if (snprintf_check(c->repair_path,
-					   sizeof(c->repair_path), "%s",
-					   optarg))
-				die("Invalid passt-repair path: %s", optarg);
-
-			break;
 		}
 	} while (name != -1);
 
-- 
2.48.1