ipfw: make algo name argument optional for some table types

Most of table types currently supported by ipfw have only one
algorithm implementation. When user creates such tables, allow
to omit algo name in arguments. E.g. now it is possible:
	ipfw table T1 create type number
	ipfw table T2 create type iface
	ipfw table T3 create type flow

PR:		233072
MFC after:	1 week
Sponsored by:	Yandex LLC

1 files changed, 18 insertions, 2 deletions

diff --git a/sbin/ipfw/tables.c b/sbin/ipfw/tables.c
index 57b8cef00889..81cf7e392586 100644
--- a/sbin/ipfw/tables.c
+++ b/sbin/ipfw/tables.c
@@ -83,6 +83,15 @@ static struct _s_x tabletypes[] = {
       { NULL, 0 }
 };
 
+/* Default algorithms for various table types */
+static struct _s_x tablealgos[] = {
+      { "addr:radix",	IPFW_TABLE_ADDR },
+      { "flow:hash",	IPFW_TABLE_FLOW },
+      { "iface:array",	IPFW_TABLE_INTERFACE },
+      { "number:array",	IPFW_TABLE_NUMBER },
+      { NULL, 0 }
+};
+
 static struct _s_x tablevaltypes[] = {
       { "skipto",	IPFW_VTYPE_SKIPTO },
       { "pipe",		IPFW_VTYPE_PIPE },
@@ -468,8 +477,15 @@ table_create(ipfw_obj_header *oh, int ac, char *av[])
 	}
 
 	/* Set some defaults to preserve compatibility. */
-	if (xi.algoname[0] == '\0' && xi.type == 0)
-		xi.type = IPFW_TABLE_ADDR;
+	if (xi.algoname[0] == '\0') {
+		const char *algo;
+
+		if (xi.type == 0)
+			xi.type = IPFW_TABLE_ADDR;
+		algo = match_value(tablealgos, xi.type);
+		if (algo != NULL)
+			strlcpy(xi.algoname, algo, sizeof(xi.algoname));
+	}
 	if (xi.vmask == 0)
 		xi.vmask = IPFW_VTYPE_LEGACY;