syscall/open: add the full suite of READ/WRITE flags

4 files changed, 33 insertions, 17 deletions

diff --git a/src/kernel/handle.h b/src/kernel/handle.h
index 6b095e5..3c16061 100644
--- a/src/kernel/handle.h
+++ b/src/kernel/handle.h
@@ -19,7 +19,8 @@ struct handle {
 	enum handle_type type;
 	struct vfs_backend *backend; // HANDLE_FILE | HANDLE_FS_FRONT
 	void __user *file_id; // only applicable to HANDLE_FILE
-	bool ro; /* currently only for HANDLE_FILE */
+	// TODO readable/writeable could be reused for pipes
+	bool readable, writeable; /* currently only for HANDLE_FILE */
 	struct vfs_request *req; /* HANDLE_FS_REQ */
 	struct {
 		struct process *queued;
diff --git a/src/kernel/syscalls.c b/src/kernel/syscalls.c
index aa3c28f..dc8f9df 100644
--- a/src/kernel/syscalls.c
+++ b/src/kernel/syscalls.c
@@ -83,7 +83,7 @@ handle_t _syscall_open(const char __user *path, long len, int flags) {
 	struct vfs_mount *mount;
 	char *path_buf = NULL;
 
-	if (flags & ~(OPEN_CREATE | OPEN_RO)) SYSCALL_RETURN(-ENOSYS);
+	if (flags & ~(OPEN_RW | OPEN_CREATE)) SYSCALL_RETURN(-ENOSYS);
 
 	if (PATH_MAX < len)
 		SYSCALL_RETURN(-1);
@@ -184,11 +184,16 @@ static long simple_vfsop(
 		enum vfs_operation vfsop, handle_t hid, void __user *buf,
 		size_t len, long offset, int flags)
 {
-	assert(vfsop != VFSOP_OPEN && vfsop != VFSOP_CLOSE);
+	assert(vfsop == VFSOP_READ
+		|| vfsop == VFSOP_WRITE
+		|| vfsop == VFSOP_GETSIZE);
 	struct handle *h = process_handle_get(process_current, hid);
 	if (!h) SYSCALL_RETURN(-1);
 	if (h->type == HANDLE_FILE) {
-		if (h->ro && !(vfsop == VFSOP_READ || vfsop == VFSOP_GETSIZE))
+		// TODO those checks really need some comprehensive tests
+		if (!h->readable && vfsop == VFSOP_READ)
+			SYSCALL_RETURN(-EACCES);
+		if (!h->writeable && vfsop == VFSOP_WRITE)
 			SYSCALL_RETURN(-EACCES);
 		struct vfs_request req = (struct vfs_request){
 			.type = vfsop,
@@ -235,19 +240,22 @@ long _syscall_getsize(handle_t hid) {
 long _syscall_remove(handle_t hid) {
 	struct handle *h = process_handle_get(process_current, hid);
 	if (!h) SYSCALL_RETURN(-EBADF);
-	if (!h->ro && h->type == HANDLE_FILE) {
-		vfsreq_create((struct vfs_request) {
-				.type = VFSOP_REMOVE,
-				.id = h->file_id,
-				.caller = process_current,
-				.backend = h->backend,
-			});
+	if (h->type != HANDLE_FILE) {
 		process_handle_close(process_current, hid);
-		return -1; // dummy
-	} else {
+		SYSCALL_RETURN(-ENOSYS);
+	}
+	if (!h->writeable) {
 		process_handle_close(process_current, hid);
-		SYSCALL_RETURN(h->ro ? -EACCES : -ENOSYS);
+		SYSCALL_RETURN(-EACCES);
 	}
+	vfsreq_create((struct vfs_request) {
+			.type = VFSOP_REMOVE,
+			.id = h->file_id,
+			.caller = process_current,
+			.backend = h->backend,
+		});
+	process_handle_close(process_current, hid);
+	return -1; // dummy
 }
 
 long _syscall_close(handle_t hid) {
diff --git a/src/kernel/vfs/request.c b/src/kernel/vfs/request.c
index 24d5dac..0a377d3 100644
--- a/src/kernel/vfs/request.c
+++ b/src/kernel/vfs/request.c
@@ -23,8 +23,12 @@ void vfsreq_create(struct vfs_request req_) {
 	memcpy(req, &req_, sizeof *req);
 	if (req->backend) req->backend->refcount++;
 
-	if (req->type == VFSOP_OPEN && (req->flags & OPEN_RO))
-		req->flags &= ~OPEN_CREATE;
+	if (req->type == VFSOP_OPEN && !(req->flags & OPEN_WRITE) && (req->flags & OPEN_CREATE)) {
+		vfsreq_finish_short(req, -EINVAL);
+		return;
+	}
+
+	// TODO if i add a handle field to vfs_request, check ->readable ->writeable here
 
 	if (req->backend && req->backend->potential_handlers) {
 		struct vfs_request **iter = &req->backend->queue;
@@ -47,7 +51,8 @@ void vfsreq_finish(struct vfs_request *req, char __user *stored, long ret,
 			h = handle_init(HANDLE_FILE);
 			h->backend = req->backend; req->backend->refcount++;
 			h->file_id = stored;
-			h->ro = req->flags & OPEN_RO;
+			h->readable = OPEN_READABLE(req->flags);
+			h->writeable = OPEN_WRITEABLE(req->flags);
 		} else {
 			/* delegating - moving a handle to the caller */
 			assert(handler);
diff --git a/src/kernel/vfs/request.h b/src/kernel/vfs/request.h
index 4e309b0..db707d0 100644
--- a/src/kernel/vfs/request.h
+++ b/src/kernel/vfs/request.h
@@ -42,6 +42,8 @@ struct vfs_request {
 		size_t len;
 	} output;
 
+	// TODO why doesn't this just have a reference to the handle?
+
 	void __user *id; // handle.file.id
 	long offset;
 	int flags;