1 files changed, 18 insertions, 77 deletions

diff --git a/lib9p/9p.c b/lib9p/9p.c
index 74a786c..c11bcd6 100644
--- a/lib9p/9p.c
+++ b/lib9p/9p.c
@@ -123,17 +123,8 @@ ssize_t _lib9p_validate(uint8_t                          xxx_low_typ_bit,
                         const struct _lib9p_recv_tentry  xxx_table[LIB9P_VER_NUM][0x80],
                         struct lib9p_ctx *ctx, uint8_t *net_bytes) {
 	/* Inspect the first 5 bytes ourselves.  */
-	struct _validate_ctx subctx = {
-		/* input */
-		.ctx        = ctx,
-		.net_size   = uint32le_decode(net_bytes),
-		.net_bytes  = net_bytes,
-
-		/* output */
-		.net_offset = 0,
-		.host_extra = 0,
-	};
-	if (subctx.net_size < 5)
+	uint32_t net_size = uint32le_decode(net_bytes);
+	if (net_size < 5)
 		return lib9p_error(ctx, LINUX_EBADMSG, "message is impossibly short");
 	uint8_t typ = net_bytes[4];
 	if (typ % 2 != xxx_low_typ_bit)
@@ -145,18 +136,7 @@ ssize_t _lib9p_validate(uint8_t                          xxx_low_typ_bit,
 		                    lib9p_msgtype_str(ctx->version, typ), lib9p_version_str(ctx->version));
 
 	/* Now use the message-type-specific tentry to process the whole thing.  */
-	if (tentry.validate(&subctx))
-		return -1;
-	assert(subctx.net_offset <= subctx.net_size);
-	if (subctx.net_offset < subctx.net_size)
-		return lib9p_errorf(ctx, LINUX_EBADMSG, "message has %"PRIu32" extra bytes",
-		                   subctx.net_size - subctx.net_offset);
-
-	/* Return.  */
-	ssize_t ret;
-	if (__builtin_add_overflow(tentry.basesize, subctx.host_extra, &ret))
-		return lib9p_error(ctx, LINUX_EMSGSIZE, "unmarshalled payload overflows SSIZE_MAX");
-	return ret;
+	return tentry.validate(ctx, net_size, net_bytes);
 }
 
 ssize_t lib9p_Tmsg_validate(struct lib9p_ctx *ctx, uint8_t *net_bytes) {
@@ -177,16 +157,7 @@ void _lib9p_unmarshal(const struct _lib9p_recv_tentry xxx_table[LIB9P_VER_NUM][0
 	*ret_typ = typ;
 	struct _lib9p_recv_tentry tentry = xxx_table[ctx->version][typ/2];
 
-	struct _unmarshal_ctx subctx = {
-		/* input */
-		.ctx        = ctx,
-		.net_bytes  = net_bytes,
-
-		/* output */
-		.net_offset = 0,
-		.extra      = ret_body + tentry.basesize,
-	};
-	tentry.unmarshal(&subctx, ret_body);
+	tentry.unmarshal(ctx, net_bytes, ret_body);
 }
 
 void lib9p_Tmsg_unmarshal(struct lib9p_ctx *ctx, uint8_t *net_bytes,
@@ -205,11 +176,7 @@ 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) {
-	struct _marshal_ctx subctx = {
-		/* input */
-		.ctx             = ctx,
-
-		/* ouptut */
+	struct _marshal_ret ret = {
 		.net_iov_cnt     = 1,
 		.net_iov         = ret_iov,
 		.net_copied_size = 0,
@@ -217,10 +184,10 @@ bool _lib9p_marshal(const struct _lib9p_send_tentry xxx_table[LIB9P_VER_NUM][0x8
 	};
 
 	struct _lib9p_send_tentry tentry = xxx_table[ctx->version][typ/2];
-	bool ret_erred = tentry.marshal(&subctx, body);
-	if (ret_iov[subctx.net_iov_cnt-1].iov_len == 0)
-		subctx.net_iov_cnt--;
-	*ret_iov_cnt = subctx.net_iov_cnt;
+	bool ret_erred = tentry.marshal(ctx, body, &ret);
+	if (ret_iov[ret.net_iov_cnt-1].iov_len == 0)
+		ret.net_iov_cnt--;
+	*ret_iov_cnt = ret.net_iov_cnt;
 	return ret_erred;
 }
 
@@ -246,39 +213,17 @@ bool lib9p_Rmsg_marshal(struct lib9p_ctx *ctx, enum lib9p_msg_type typ, void *bo
 
 bool lib9p_stat_validate(struct lib9p_ctx *ctx, uint32_t net_size, uint8_t *net_bytes,
                          uint32_t *ret_net_size, ssize_t *ret_host_size) {
-	struct _validate_ctx subctx = {
-		/* input */
-		.ctx        = ctx,
-		.net_size   = net_size,
-		.net_bytes  = net_bytes,
-
-		/* output */
-		.net_offset = 0,
-		.host_extra = 0,
-	};
-	if (_lib9p_stat_validate(&subctx))
+	ssize_t host_size = _lib9p_stat_validate(ctx, net_size, net_bytes, ret_net_size);
+	if (host_size < 0)
 		return true;
-	if (ret_net_size)
-		*ret_net_size = subctx.net_offset;
 	if (ret_host_size)
-		if (__builtin_add_overflow(sizeof(struct lib9p_stat), subctx.host_extra, ret_host_size))
-			return lib9p_error(ctx, LINUX_EMSGSIZE, "unmarshalled stat object overflows SSIZE_MAX");
+		*ret_host_size = host_size;
 	return false;
 }
 
-uint32_t lib9p_stat_unmarshal(struct lib9p_ctx *ctx, uint8_t *net_bytes,
-                              struct lib9p_stat *ret_obj, void *ret_extra) {
-	struct _unmarshal_ctx subctx = {
-		/* input */
-		.ctx        = ctx,
-		.net_bytes  = net_bytes,
-
-		/* output */
-		.net_offset = 0,
-		.extra      = ret_extra,
-	};
-	_lib9p_stat_unmarshal(&subctx, ret_obj);
-	return subctx.net_offset;
+void lib9p_stat_unmarshal(struct lib9p_ctx *ctx, uint8_t *net_bytes,
+                          struct lib9p_stat *ret) {
+	_lib9p_stat_unmarshal(ctx, net_bytes, ret);
 }
 
 uint32_t lib9p_stat_marshal(struct lib9p_ctx *ctx, uint32_t max_net_size, struct lib9p_stat *obj,
@@ -287,17 +232,13 @@ uint32_t lib9p_stat_marshal(struct lib9p_ctx *ctx, uint32_t max_net_size, struct
 	_ctx.max_msg_size = max_net_size;
 
 	struct iovec iov = {0};
-	struct _marshal_ctx subctx = {
-		/* input */
-		.ctx             = &_ctx,
-
-		/* output */
+	struct _marshal_ret ret = {
 		.net_iov_cnt     = 1,
 		.net_iov         = &iov,
 		.net_copied_size = 0,
 		.net_copied      = ret_bytes,
 	};
-	if (_lib9p_stat_marshal(&subctx, obj))
+	if (_lib9p_stat_marshal(&_ctx, obj, &ret))
 		return 0;
-	return subctx.net_iov[0].iov_len;
+	return ret.net_iov[0].iov_len;
 }