lib9p: tables.c: More consistent bounds checks

1 files changed, 22 insertions, 9 deletions

diff --git a/lib9p/tables.c b/lib9p/tables.c
index 34ac1af..7b46fb4 100644
--- a/lib9p/tables.c
+++ b/lib9p/tables.c
@@ -11,28 +11,37 @@
 
 #include "tables.h"
 
-const char *lib9p_version_str(enum lib9p_version ver) {
+/* bounds checks **************************************************************/
+
+static inline void assert_ver(enum lib9p_version ver) {
 #pragma GCC diagnostic push
 #pragma GCC diagnostic ignored "-Wtype-limits"
 	assert(0 <= ver && ver < LIB9P_VER_NUM);
 #pragma GCC diagnostic pop
-	return _lib9p_table_ver_name[ver];
 }
 
-uint32_t lib9p_version_min_msg_size(enum lib9p_version ver) {
+static inline void assert_typ(enum lib9p_msg_type typ) {
 #pragma GCC diagnostic push
 #pragma GCC diagnostic ignored "-Wtype-limits"
-	assert(0 <= ver && ver < LIB9P_VER_NUM);
+	assert(0 <= typ && typ < 0xFF);
 #pragma GCC diagnostic pop
+}
+
+/* simple lookups *************************************************************/
+
+const char *lib9p_version_str(enum lib9p_version ver) {
+	assert_ver(ver);
+	return _lib9p_table_ver_name[ver];
+}
+
+uint32_t lib9p_version_min_msg_size(enum lib9p_version ver) {
+	assert_ver(ver);
 	return _lib9p_table_msg_min_size[ver];
 }
 
 const char *lib9p_msgtype_str(enum lib9p_version ver, enum lib9p_msg_type typ) {
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wtype-limits"
-	assert(0 <= ver && ver < LIB9P_VER_NUM);
-	assert(0 <= typ && typ <= 0xFF);
-#pragma GCC diagnostic pop
+	assert_ver(ver);
+	assert_typ(typ);
 	return _lib9p_table_msg_name[ver][typ] ?: const_byte_str(typ);
 }
 
@@ -43,6 +52,7 @@ ssize_t _lib9p_validate(uint8_t                          xxx_low_typ_bit,
                         const char                      *xxx_errmsg,
                         const struct _lib9p_recv_tentry  xxx_table[LIB9P_VER_NUM][0x80],
                         struct lib9p_ctx *ctx, uint8_t *net_bytes) {
+	assert_ver(ctx->version);
 	/* Inspect the first 5 bytes ourselves.  */
 	uint32_t net_size = uint32le_decode(net_bytes);
 	if (net_size < 5)
@@ -74,6 +84,7 @@ static
 void _lib9p_unmarshal(const struct _lib9p_recv_tentry xxx_table[LIB9P_VER_NUM][0x80],
                       struct lib9p_ctx *ctx, uint8_t *net_bytes,
                       enum lib9p_msg_type *ret_typ, void *ret_body) {
+	assert_ver(ctx->version);
 	enum lib9p_msg_type typ = net_bytes[4];
 	*ret_typ = typ;
 	struct _lib9p_recv_tentry tentry = xxx_table[ctx->version][typ/2];
@@ -97,6 +108,8 @@ static
 bool _lib9p_marshal(const struct _lib9p_send_tentry xxx_table[LIB9P_VER_NUM][0x80],
                     struct lib9p_ctx *ctx, enum lib9p_msg_type typ, void *body,
                     size_t *ret_iov_cnt, struct iovec *ret_iov, uint8_t *ret_copied) {
+	assert_ver(ctx->version);
+	assert_typ(typ);
 	struct _marshal_ret ret = {
 		.net_iov_cnt     = 1,
 		.net_iov         = ret_iov,