get read working correctly

2 files changed, 47 insertions, 30 deletions

diff --git a/lib9p/include/lib9p/9p.h b/lib9p/include/lib9p/9p.h
index 2511e3d..e7ddb15 100644
--- a/lib9p/include/lib9p/9p.h
+++ b/lib9p/include/lib9p/9p.h
@@ -56,6 +56,17 @@ static bool lib9p_ctx_has_error(struct lib9p_ctx *ctx) {
 	return ctx->err_msg[0];
 }
 
+/** Assert that a `struct lib9p_stat` object looks valid.  */
+static inline void lib9p_assert_stat(struct lib9p_stat stat) {
+	assert( ((bool)(stat.file_mode & LIB9P_DM_DIR         )) == ((bool)(stat.file_qid.type & LIB9P_QT_DIR         )) );
+	assert( ((bool)(stat.file_mode & LIB9P_DM_APPEND      )) == ((bool)(stat.file_qid.type & LIB9P_QT_APPEND      )) );
+	assert( ((bool)(stat.file_mode & LIB9P_DM_EXCL        )) == ((bool)(stat.file_qid.type & LIB9P_QT_EXCL        )) );
+	assert( ((bool)(stat.file_mode & _LIB9P_DM_PLAN9_MOUNT)) == ((bool)(stat.file_qid.type & _LIB9P_QT_PLAN9_MOUNT)) );
+	assert( ((bool)(stat.file_mode & LIB9P_DM_AUTH        )) == ((bool)(stat.file_qid.type & LIB9P_QT_AUTH        )) );
+	assert( ((bool)(stat.file_mode & LIB9P_DM_TMP         )) == ((bool)(stat.file_qid.type & LIB9P_QT_TMP         )) );
+	assert( (stat.file_size == 0) || !(stat.file_mode & LIB9P_DM_DIR) );
+}
+
 /** Write an static error into ctx, return -1.  */
 int lib9p_error(struct lib9p_ctx *ctx, uint32_t linux_errno, char const *msg);
 /** Write a printf-style error into ctx, return -1.  */
diff --git a/lib9p/srv.c b/lib9p/srv.c
index 1f62e27..6953687 100644
--- a/lib9p/srv.c
+++ b/lib9p/srv.c
@@ -386,14 +386,14 @@ static void handle_message(struct _lib9p_srv_req *ctx) {
 	}
 }
 
-#define handler_common(ctx, req, resp) do { \
+#define util_handler_common(ctx, req, resp) do { \
 		assert(ctx);                \
 		assert(req);                \
 		assert(resp);               \
 		resp->tag = req->tag;       \
 	} while (0)
 
-static inline bool check_perm(struct lib9p_srv_ctx *ctx, struct lib9p_stat *stat, uint8_t action) {
+static inline bool util_check_perm(struct lib9p_srv_ctx *ctx, struct lib9p_stat *stat, uint8_t action) {
 	assert(ctx);
 	assert(stat);
 	assert(action);
@@ -404,12 +404,12 @@ static inline bool check_perm(struct lib9p_srv_ctx *ctx, struct lib9p_stat *stat
 	return mode & action;
 }
 
-static inline bool release(struct lib9p_srv_ctx *ctx, struct lib9p_srv_file *file) {
+static inline bool util_release(struct lib9p_srv_ctx *ctx, struct lib9p_srv_file *file) {
 	assert(file);
 	file->_refcount--;
 	if (file->_refcount == 0) {
 		if (file->_parent_dir != file)
-			release(ctx, file->_parent_dir);
+			util_release(ctx, file->_parent_dir);
 		file->vtable->free(ctx, file);
 	}
 	return lib9p_ctx_has_error(&ctx->basectx);
@@ -418,7 +418,7 @@ static inline bool release(struct lib9p_srv_ctx *ctx, struct lib9p_srv_file *fil
 static void handle_Tversion(struct _lib9p_srv_req *ctx,
                             struct lib9p_msg_Tversion *req,
                             struct lib9p_msg_Rversion *resp) {
-	handler_common(ctx, req, resp);
+	util_handler_common(ctx, req, resp);
 
 	enum lib9p_version version = LIB9P_VER_unknown;
 
@@ -494,7 +494,7 @@ static void handle_Tversion(struct _lib9p_srv_req *ctx,
 static void handle_Tauth(struct _lib9p_srv_req *ctx,
                          struct lib9p_msg_Tauth *req,
                          struct lib9p_msg_Rauth *resp) {
-	handler_common(ctx, req, resp);
+	util_handler_common(ctx, req, resp);
 
 	ctx->ctx.uid = req->n_uname;
 	ctx->ctx.uname = req->uname.utf8;
@@ -514,7 +514,7 @@ static void handle_Tauth(struct _lib9p_srv_req *ctx,
 static void handle_Tattach(struct _lib9p_srv_req *ctx,
                            struct lib9p_msg_Tattach *req,
                            struct lib9p_msg_Rattach *resp) {
-	handler_common(ctx, req, resp);
+	util_handler_common(ctx, req, resp);
 
 	ctx->ctx.uid = req->n_uname;
 	ctx->ctx.uname = req->uname.utf8;
@@ -574,7 +574,7 @@ static void handle_Tattach(struct _lib9p_srv_req *ctx,
 			})) {
 		lib9p_error(&ctx->ctx.basectx,
 		            LINUX_EMFILE, "too many open files");
-		release(&ctx->ctx, rootdir);
+		util_release(&ctx->ctx, rootdir);
 		return;
 	}
 
@@ -585,6 +585,7 @@ static void handle_Tattach(struct _lib9p_srv_req *ctx,
 		              &(struct lib9p_msg_Rclunk){});
 		return;
 	}
+	lib9p_assert_stat(stat);
 	assert(stat.file_mode & LIB9P_DM_DIR);
 
 
@@ -595,7 +596,7 @@ static void handle_Tattach(struct _lib9p_srv_req *ctx,
 static void handle_Tflush(struct _lib9p_srv_req *ctx,
                           struct lib9p_msg_Tflush *req,
                           struct lib9p_msg_Rflush *resp) {
-	handler_common(ctx, req, resp);
+	util_handler_common(ctx, req, resp);
 
 	struct _lib9p_srv_req **oldreqp = reqmap_load(&ctx->parent_sess->reqs, req->oldtag);
 	if (oldreqp)
@@ -605,7 +606,7 @@ static void handle_Tflush(struct _lib9p_srv_req *ctx,
 static void handle_Twalk(struct _lib9p_srv_req *ctx,
                          struct lib9p_msg_Twalk *req,
                          struct lib9p_msg_Rwalk *resp) {
-	handler_common(ctx, req, resp);
+	util_handler_common(ctx, req, resp);
 
 	struct _srv_fidinfo *fidinfo = fidmap_load(&ctx->parent_sess->fids, req->fid);
 	if (!fidinfo) {
@@ -632,7 +633,7 @@ static void handle_Twalk(struct _lib9p_srv_req *ctx,
 	resp->wqid = (struct lib9p_qid *)(&resp[1]);
 	for (resp->nwqid = 0; resp->nwqid < req->nwname; resp->nwqid++) {
 		struct lib9p_srv_file *member;
-		if (strcmp(req->wname[resp->nwqid].utf8, "..")) {
+		if (strcmp(req->wname[resp->nwqid].utf8, "..") == 0) {
 			member = dir->_parent_dir;
 		} else {
 			if (!isdir) {
@@ -652,21 +653,22 @@ static void handle_Twalk(struct _lib9p_srv_req *ctx,
 
 		struct lib9p_stat stat = member->vtable->stat(&ctx->ctx, member);
 		if (lib9p_ctx_has_error(&ctx->ctx.basectx)) {
-			release(&ctx->ctx, member); /* presumption of taking ref-A failed */
+			util_release(&ctx->ctx, member); /* presumption of taking ref-A failed */
 			break;
 		}
+		lib9p_assert_stat(stat);
 		isdir = stat.file_mode & LIB9P_DM_DIR;
-		if (isdir && !check_perm(&ctx->ctx, &stat, 0b001)) {
+		if (isdir && !util_check_perm(&ctx->ctx, &stat, 0b001)) {
 			lib9p_error(&ctx->ctx.basectx,
 			            LINUX_EACCES, "you do not have execute permission on that directory");
-			release(&ctx->ctx, member); /* presumption of taking ref-A failed */
+			util_release(&ctx->ctx, member); /* presumption of taking ref-A failed */
 			break;
 		}
 
 		resp->wqid[resp->nwqid] = stat.file_qid;
 
 		/* presumption of taking ref-A succeeded */
-		release(&ctx->ctx, dir);
+		util_release(&ctx->ctx, dir);
 		dir = member;
 	}
 	if (resp->nwqid == req->nwname) {
@@ -681,12 +683,12 @@ static void handle_Twalk(struct _lib9p_srv_req *ctx,
 				})) {
 			lib9p_error(&ctx->ctx.basectx,
 			            LINUX_EMFILE, "too many open files");
-			release(&ctx->ctx, dir); /* presumption of insertion failed */
+			util_release(&ctx->ctx, dir); /* presumption of insertion failed */
 		}
 	} else {
 		assert(lib9p_ctx_has_error(&ctx->ctx.basectx));
 		if (req->newfid != req->fid)
-			release(&ctx->ctx, dir); /* presumption of insertion failed */
+			util_release(&ctx->ctx, dir); /* presumption of insertion failed */
 		if (resp->nwqid > 0)
 			lib9p_ctx_clear_error(&ctx->ctx.basectx);
 	}
@@ -695,7 +697,7 @@ static void handle_Twalk(struct _lib9p_srv_req *ctx,
 static void handle_Topen(struct _lib9p_srv_req *ctx,
                          struct lib9p_msg_Topen *req,
                          struct lib9p_msg_Ropen *resp) {
-	handler_common(ctx, req, resp);
+	util_handler_common(ctx, req, resp);
 
 	/* Check that the FID is valid for this.  */
 	struct _srv_fidinfo *fidinfo = fidmap_load(&ctx->parent_sess->fids, req->fid);
@@ -729,7 +731,8 @@ static void handle_Topen(struct _lib9p_srv_req *ctx,
 		struct lib9p_stat parent_stat = file->_parent_dir->vtable->stat(&ctx->ctx, file->_parent_dir);
 		if (lib9p_ctx_has_error(&ctx->ctx.basectx))
 			return;
-		if (!check_perm(&ctx->ctx, &parent_stat, 0b010)) {
+		lib9p_assert_stat(parent_stat);
+		if (!util_check_perm(&ctx->ctx, &parent_stat, 0b010)) {
 			lib9p_error(&ctx->ctx.basectx,
 			            LINUX_EACCES, "permission denied to remove-on-close");
 			return;
@@ -739,6 +742,7 @@ static void handle_Topen(struct _lib9p_srv_req *ctx,
 	struct lib9p_stat stat = file->vtable->stat(&ctx->ctx, file);
 	if (lib9p_ctx_has_error(&ctx->ctx.basectx))
 		return;
+	lib9p_assert_stat(stat);
 	if (stat.file_mode & LIB9P_QT_APPEND)
 		reqmode = reqmode & ~LIB9P_O_TRUNC;
 	uint8_t perm_bits = 0;
@@ -760,7 +764,7 @@ static void handle_Topen(struct _lib9p_srv_req *ctx,
 		fidflags = fidflags | FIDFLAG_OPEN_R;
 		break;
 	}
-	if (!check_perm(&ctx->ctx, &stat, perm_bits)) {
+	if (!util_check_perm(&ctx->ctx, &stat, perm_bits)) {
 		lib9p_error(&ctx->ctx.basectx,
 		            LINUX_EACCES, "permission denied");
 	}
@@ -779,7 +783,7 @@ static void handle_Topen(struct _lib9p_srv_req *ctx,
 static void handle_Tcreate(struct _lib9p_srv_req *ctx,
                            struct lib9p_msg_Tcreate *req,
                            struct lib9p_msg_Rcreate *resp) {
-	handler_common(ctx, req, resp);
+	util_handler_common(ctx, req, resp);
 
 	lib9p_error(&ctx->ctx.basectx,
 	            LINUX_EOPNOTSUPP, "create not (yet?) implemented");
@@ -788,7 +792,7 @@ static void handle_Tcreate(struct _lib9p_srv_req *ctx,
 static void handle_Tread(struct _lib9p_srv_req *ctx,
                          struct lib9p_msg_Tread *req,
                          struct lib9p_msg_Rread *resp) {
-	handler_common(ctx, req, resp);
+	util_handler_common(ctx, req, resp);
 
 	/* Check that the FID is valid for this.  */
 	struct _srv_fidinfo *fidinfo = fidmap_load(&ctx->parent_sess->fids, req->fid);
@@ -837,7 +841,7 @@ static void handle_Tread(struct _lib9p_srv_req *ctx,
 static void handle_Twrite(struct _lib9p_srv_req *ctx,
                           struct lib9p_msg_Twrite *req,
                           struct lib9p_msg_Rwrite *resp) {
-	handler_common(ctx, req, resp);
+	util_handler_common(ctx, req, resp);
 
 	/* Check that the FID is valid for this.  */
 	struct _srv_fidinfo *fidinfo = fidmap_load(&ctx->parent_sess->fids, req->fid);
@@ -862,7 +866,7 @@ static void handle_Twrite(struct _lib9p_srv_req *ctx,
 static void handle_Tclunk(struct _lib9p_srv_req *ctx,
                           struct lib9p_msg_Tclunk *req,
                           struct lib9p_msg_Rclunk *resp) {
-	handler_common(ctx, req, resp);
+	util_handler_common(ctx, req, resp);
 
 	struct _srv_fidinfo *fidinfo = fidmap_load(&ctx->parent_sess->fids, req->fid);
 	if (!fidinfo) {
@@ -884,7 +888,7 @@ static void handle_Tclunk(struct _lib9p_srv_req *ctx,
 static void handle_Tremove(struct _lib9p_srv_req *ctx,
                            struct lib9p_msg_Tremove *req,
                            struct lib9p_msg_Rremove *resp) {
-	handler_common(ctx, req, resp);
+	util_handler_common(ctx, req, resp);
 
 	lib9p_error(&ctx->ctx.basectx,
 	            LINUX_EOPNOTSUPP, "remove not (yet?) implemented");
@@ -893,7 +897,7 @@ static void handle_Tremove(struct _lib9p_srv_req *ctx,
 static void handle_Tstat(struct _lib9p_srv_req *ctx,
                          struct lib9p_msg_Tstat *req,
                          struct lib9p_msg_Rstat *resp) {
-	handler_common(ctx, req, resp);
+	util_handler_common(ctx, req, resp);
 
 	struct _srv_fidinfo *fidinfo = fidmap_load(&ctx->parent_sess->fids, req->fid);
 	if (!fidinfo) {
@@ -903,12 +907,14 @@ static void handle_Tstat(struct _lib9p_srv_req *ctx,
 	}
 
 	resp->stat = fidinfo->file->vtable->stat(&ctx->ctx, fidinfo->file);
+	if (!lib9p_ctx_has_error(&ctx->ctx.basectx))
+		lib9p_assert_stat(resp->stat);
 }
 
 static void handle_Twstat(struct _lib9p_srv_req *ctx,
                           struct lib9p_msg_Twstat *req,
                           struct lib9p_msg_Rwstat *resp) {
-	handler_common(ctx, req, resp);
+	util_handler_common(ctx, req, resp);
 
 	lib9p_error(&ctx->ctx.basectx,
 	            LINUX_EOPNOTSUPP, "wstat not (yet?) implemented");
@@ -918,7 +924,7 @@ static void handle_Twstat(struct _lib9p_srv_req *ctx,
 static void handle_Tsession(struct _lib9p_srv_req *ctx,
                             struct lib9p_msg_Tsession *req,
                             struct lib9p_msg_Rsession *resp) {
-	handler_common(ctx, req, resp);
+	util_handler_common(ctx, req, resp);
 
 	lib9p_error(&ctx->ctx.basectx,
 	            LINUX_EOPNOTSUPP, "session not (yet?) implemented");
@@ -927,7 +933,7 @@ static void handle_Tsession(struct _lib9p_srv_req *ctx,
 static void handle_Tsread(struct _lib9p_srv_req *ctx,
                           struct lib9p_msg_Tsread *req,
                           struct lib9p_msg_Rsread *resp) {
-	handler_common(ctx, req, resp);
+	util_handler_common(ctx, req, resp);
 
 	lib9p_error(&ctx->ctx.basectx,
 	            LINUX_EOPNOTSUPP, "sread not (yet?) implemented");
@@ -936,7 +942,7 @@ static void handle_Tsread(struct _lib9p_srv_req *ctx,
 static void handle_Tswrite(struct _lib9p_srv_req *ctx,
                            struct lib9p_msg_Tswrite *req,
                            struct lib9p_msg_Rswrite *resp) {
-	handler_common(ctx, req, resp);
+	util_handler_common(ctx, req, resp);
 
 	lib9p_error(&ctx->ctx.basectx,
 	            LINUX_EOPNOTSUPP, "swrite not (yet?) implemented");