nfct: Update syntax to specify command before subsystem

This patch gets the nfct syntax in sync with nft so it looks like this:

	nfct <add|delete|...> object ...

instead of:

	nfct object <add|delete|...> ...

This patch retains backward compatibility so you can still use the old syntax.
The manpage and tests have been also updated to promote the adoption of this
syntax. We should have little existing clients of this tool as we can only use
this to configure the cttimeout and cthelper infrastructures.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

1 files changed, 79 insertions, 18 deletions

diff --git a/src/nfct.c b/src/nfct.c
index 533d75d..3331e5b 100644
--- a/src/nfct.c
+++ b/src/nfct.c
@@ -31,7 +31,7 @@ static int nfct_cmd_help(int argc, char *argv[]);
 
 static void usage(char *argv[])
 {
-	fprintf(stderr, "Usage: %s subsystem command [parameters]...\n",
+	fprintf(stderr, "Usage: %s command subsystem [parameters]...\n",
 		argv[0]);
 }
 
@@ -63,32 +63,93 @@ static struct nfct_extension *nfct_extension_lookup(int type)
 	return NULL;
 }
 
+static const char *nfct_cmd_array[NFCT_CMD_MAX] = {
+	[NFCT_CMD_LIST]		= "list",
+	[NFCT_CMD_ADD]		= "add",
+	[NFCT_CMD_DELETE]	= "delete",
+	[NFCT_CMD_GET]		= "get",
+	[NFCT_CMD_FLUSH]	= "flush",
+	[NFCT_CMD_DISABLE]	= "disable",
+	[NFCT_CMD_DEFAULT_SET]	= "default-set",
+	[NFCT_CMD_DEFAULT_GET]	= "default-get",
+};
+
+static int nfct_cmd_parse(const char *cmdstr)
+{
+	int i;
+
+	for (i = 1; i < NFCT_CMD_MAX; i++) {
+		if (strncmp(nfct_cmd_array[i], cmdstr, strlen(cmdstr)) == 0)
+			return i;
+	}
+	return -1;
+}
+
+static int nfct_cmd_error(char *argv[])
+{
+	fprintf(stderr, "nfct v%s: Unknown command: %s\n", VERSION, argv[1]);
+	usage(argv);
+
+	return EXIT_FAILURE;
+}
+
+static const char *nfct_subsys_array[NFCT_SUBSYS_MAX] = {
+	[NFCT_SUBSYS_TIMEOUT]	= "timeout",
+	[NFCT_SUBSYS_HELPER]	= "helper",
+	[NFCT_SUBSYS_VERSION]	= "version",
+	[NFCT_SUBSYS_HELP]	= "help",
+};
+
+static int nfct_subsys_parse(const char *cmdstr)
+{
+	int i;
+
+	for (i = 1; i < NFCT_SUBSYS_MAX; i++) {
+		if (strncmp(nfct_subsys_array[i], cmdstr, strlen(cmdstr)) == 0)
+			return i;
+	}
+	return -1;
+}
+
+static int nfct_subsys_error(char *argv[])
+{
+	fprintf(stderr, "nfct v%s: Unknown subsystem: %s\n", VERSION, argv[1]);
+	usage(argv);
+
+	return EXIT_FAILURE;
+}
+
 int main(int argc, char *argv[])
 {
-	int subsys = NFCT_SUBSYS_NONE, ret = 0;
+	int subsys, cmd, ret = 0;
 	struct nfct_extension *ext;
 	struct mnl_socket *nl;
 
-	if (argc < 2) {
+	if (argc < 3) {
 		usage(argv);
 		exit(EXIT_FAILURE);
 	}
-	if (strncmp(argv[1], "timeout", strlen(argv[1])) == 0) {
-		subsys = NFCT_SUBSYS_TIMEOUT;
-	} else if (strncmp(argv[1], "helper", strlen(argv[1])) == 0) {
-		subsys = NFCT_SUBSYS_HELPER;
-	} else if (strncmp(argv[1], "version", strlen(argv[1])) == 0)
-		subsys = NFCT_SUBSYS_VERSION;
-	else if (strncmp(argv[1], "help", strlen(argv[1])) == 0)
-		subsys = NFCT_SUBSYS_HELP;
-	else {
-		fprintf(stderr, "nfct v%s: Unknown subsystem: %s\n",
-			VERSION, argv[1]);
-		usage(argv);
-		exit(EXIT_FAILURE);
+
+	cmd = nfct_cmd_parse(argv[1]);
+	if (cmd < 0) {
+		/* Workaround not to break backward compatibility and to get
+		 * the syntax in sync with nft. Old nfct versions allow to
+		 * specify the subsystem before the command.
+		 */
+		subsys = nfct_subsys_parse(argv[1]);
+		if (subsys < 0)
+			return nfct_subsys_error(argv);
+
+		cmd = nfct_cmd_parse(argv[2]);
+		if (cmd < 0)
+			return nfct_cmd_error(argv);
+	} else {
+		subsys = nfct_subsys_parse(argv[2]);
+		if (subsys < 0)
+			return nfct_subsys_error(argv);
 	}
 
-	switch(subsys) {
+	switch (subsys) {
 	case NFCT_SUBSYS_VERSION:
 		ret = nfct_cmd_version(argc, argv);
 		break;
@@ -109,7 +170,7 @@ int main(int argc, char *argv[])
 			return -1;
 		}
 
-		ret = ext->parse_params(nl, argc, argv);
+		ret = ext->parse_params(nl, argc, argv, cmd);
 		mnl_socket_close(nl);
 		break;
 	}