implement dread

1 files changed, 48 insertions, 8 deletions

diff --git a/lib9p/srv.c b/lib9p/srv.c
index 8940afe..04cd119 100644
--- a/lib9p/srv.c
+++ b/lib9p/srv.c
@@ -729,12 +729,10 @@ static void handle_Topen(struct _lib9p_srv_req *ctx,
 	if (lib9p_ctx_has_error(&ctx->ctx.basectx))
 		return;
 
-	filep->_io_flags = flags;
-	filep->_io_unit = iounit;
-	filep->_io_qid = stat.file_qid;
-
-	resp->qid = filep->_io_qid;
-	resp->iounit = filep->_io_unit;
+	filep->_io_flags = filep->_io_flags | flags;
+	filep->_io_isdir = stat.file_mode & LIB9P_DM_DIR;
+	resp->qid = stat.file_qid;
+	resp->iounit = iounit;
 }
 
 static void handle_Tcreate(struct _lib9p_srv_req *ctx,
@@ -751,8 +749,50 @@ static void handle_Tread(struct _lib9p_srv_req *ctx,
                          struct lib9p_msg_Rread *resp) {
 	handler_common(ctx, req, resp);
 
-	lib9p_error(&ctx->ctx.basectx,
-	            LINUX_EOPNOTSUPP, "read not yet implemented");
+	struct lib9p_srv_file **filepp = fidmap_load(&ctx->parent_sess->fids, req->fid);
+	if (!filepp) {
+		lib9p_errorf(&ctx->ctx.basectx,
+		             LINUX_EBADF, "bad file number %"PRIu32, req->fid);
+		return;
+	}
+	struct lib9p_srv_file *filep = *filepp;
+
+	switch (filep->_io_flags & LIB9P_O_MODE_MASK) {
+	case LIB9P_O_READ:
+	case LIB9P_O_RDWR:
+		/* ok */
+		break;
+	default:
+		lib9p_error(&ctx->ctx.basectx,
+		            LINUX_EINVAL, "FID not open for reading");
+		return;
+	}
+
+	resp->data.dat = (char *)(&resp[1]);
+	if (filep->_io_isdir) {
+		size_t idx;
+		if (req->offset == 0)
+			idx = 0;
+		else if (req->offset == filep->_io_dir_off)
+			idx = filep->_io_dir_idx;
+		else {
+			lib9p_errorf(&ctx->ctx.basectx,
+			             LINUX_EINVAL, "invalid offset (must be 0 or %"PRIu32"): %"PRIu32,
+			             filep->_io_dir_off, req->offset);
+			return;
+		}
+		size_t num = filep->vtable->dread(&ctx->ctx, filep, (uint8_t *)resp->data.dat, req->count, idx);
+		filep->_io_dir_idx = idx+num;
+		uint32_t len = 0;
+		for (size_t i = 0; i < num; i++) {
+			uint32_t i_len;
+			lib9p_validate_stat(&ctx->ctx.basectx, req->count, (uint8_t *)resp->data.dat, &i_len, NULL);
+			len += i_len;
+		}
+		filep->_io_dir_off = req->offset + len;
+		resp->data.len = len;
+	} else
+		resp->data.len = filep->vtable->pread(&ctx->ctx, filep, resp->data.dat, req->count, req->offset);
 }
 
 static void handle_Twrite(struct _lib9p_srv_req *ctx,