build: allow disabling libreadline-support

This makes nftables a bit more embedded-friendly.

Signed-off-by: Steven Barth <cyrus@openwrt.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

4 files changed, 20 insertions, 1 deletions

diff --git a/configure.ac b/configure.ac
index 3a7647f2..ea13cf8c 100644
--- a/configure.ac
+++ b/configure.ac
@@ -71,8 +71,14 @@ AC_CHECK_LIB([nftnl], [nft_rule_alloc], ,
 AC_CHECK_LIB([gmp], [__gmpz_init], ,
 	     AC_MSG_ERROR([No suitable version of libgmp found]))
 
+AC_ARG_WITH([cli], [AS_HELP_STRING([--without-cli],
+            [disable interactive CLI (libreadline support)])],
+            [], [with_cli=yes])
+AS_IF([test "x$with_cli" != xno], [
 AC_CHECK_LIB([readline], [readline], ,
 	     AC_MSG_ERROR([No suitable version of libreadline found]))
+])
+AC_SUBST(with_cli)
 
 # Checks for header files.
 AC_HEADER_STDC
diff --git a/include/nftables.h b/include/nftables.h
index 3394e324..c3d3dbfb 100644
--- a/include/nftables.h
+++ b/include/nftables.h
@@ -31,7 +31,14 @@ extern unsigned int debug_level;
 extern const char *include_paths[INCLUDE_PATHS_MAX];
 
 struct parser_state;
+#ifdef HAVE_LIBREADLINE
 extern int cli_init(struct parser_state *state);
+#else
+static inline int cli_init(struct parser_state *state)
+{
+	return -1;
+}
+#endif
 extern void cli_exit(void);
 extern void cli_display(const char *fmt, va_list ap) __fmtstring(1, 0);
 
diff --git a/src/Makefile.in b/src/Makefile.in
index 8ac2b460..7ecc5f2e 100644
--- a/src/Makefile.in
+++ b/src/Makefile.in
@@ -3,7 +3,9 @@ PROGRAMS		+= nft
 nft-destdir		:= @sbindir@
 
 nft-obj			+= main.o
+ifeq (@with_cli@,yes)
 nft-obj			+= cli.o
+endif
 nft-obj			+= rule.o
 nft-obj			+= statement.o
 nft-obj			+= datatype.o
diff --git a/src/main.c b/src/main.c
index 2685b0db..3607bd58 100644
--- a/src/main.c
+++ b/src/main.c
@@ -335,7 +335,11 @@ int main(int argc, char * const *argv)
 		if (scanner_read_file(scanner, filename, &internal_location) < 0)
 			goto out;
 	} else if (interactive) {
-		cli_init(&state);
+		if (cli_init(&state) < 0) {
+			fprintf(stderr, "%s: interactive CLI not supported in this build\n",
+				argv[0]);
+			exit(NFT_EXIT_FAILURE);
+		}
 		return 0;
 	} else {
 		fprintf(stderr, "%s: no command specified\n", argv[0]);