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
Sponsored by:	Yandex LLC

(cherry picked from commit 13ad237a19b7368124483d9d1dc3258c27880fef)

1 files changed, 18 insertions, 2 deletions

diff --git a/sbin/ipfw/tables.c b/sbin/ipfw/tables.c
index e914ad63343c..12e5a4cc435f 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 },
@@ -469,8 +478,15 @@ 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;