From abe65b09bbbb92f384c5b8e78014f3849b1b2ce1 Mon Sep 17 00:00:00 2001
From: Martin Lenders <mlenders@inf.fu-berlin.de>
Date: Sat, 21 Sep 2013 15:23:40 +0200
Subject: [PATCH] Implement file descriptor table
Needed for pnet
---
sys/include/fd.h | 89 +++++++++++++++++++++++++++++++++++++++++++
sys/posix/fd.c | 99 ++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 188 insertions(+)
create mode 100644 sys/include/fd.h
create mode 100644 sys/posix/fd.c
diff --git a/sys/include/fd.h b/sys/include/fd.h
new file mode 100644
index 0000000000..9b5fa98bec
--- /dev/null
+++ b/sys/include/fd.h
@@ -0,0 +1,89 @@
+/*
+ * Copyright (C) 2013 INRIA.
+ *
+ * This file subject to the terms and conditions of the GNU Lesser General
+ * Public License. See the file LICENSE in the top level directory for more
+ * details.
+ */
+
+/**
+ * @addtogroup posix
+ * @{
+ */
+
+/**
+ * @file fd.h
+ * @brief Unifies diverse identifiers of RIOT to POSIX like file descriptors.
+ *
+ * @author Freie Universität Berlin
+ * @author Martin Lenders <mlenders@inf.fu-berlin.de>
+ * @author Christian Mehlis <mehlis@inf.fu-berlin.de>
+ */
+#ifndef FD_H
+#define FD_H
+#include <stdlib.h>
+#include <sys/types.h>
+
+/**
+ * File descriptor table.
+ */
+typedef struct {
+ /** private status of this fd_t */
+ int __active;
+
+ /** the internal filedescriptor */
+ int fd;
+
+ /**
+ * Read *n* into *buf* from *fd*. Return the
+ * number read, -1 for errors or 0 for EOF.
+ */
+ ssize_t (*read)(int fd, void *buf, size_t n);
+
+ /** Write *n* bytes of *buf* to *fd*. Return the number written, or -1. */
+ ssize_t (*write)(int fd, const void *buf, size_t n);
+
+ /** Close the file descriptor *fd*. */
+ int (*close)(int fd);
+} fd_t;
+
+/**
+ * @brief Initializes file descriptors
+ *
+ * @return maximum number of available file descriptors.
+ */
+int fd_init(void);
+
+/**
+ * @brief Creates a new file descriptor.
+ *
+ * @param[in] internal_fd RIOT-internal identifier for the new FD.
+ * @param[in] internal_read Function to read from new FD.
+ * @param[in] internal_write Function to write into new FD.
+ * @param[in] internal_close Function to close new FD.
+ *
+ * @return 0 on success, -1 otherwise. *errno* is set accordingly.
+ */
+int fd_new(int internal_fd, ssize_t (*internal_read)(int, void *, size_t),
+ ssize_t (*internal_write)(int, const void *, size_t),
+ int (*internal_close)(int));
+
+/**
+ * @brief Gets the file descriptor table entry associated with file
+ * descriptor *fd*.
+ *
+ * @param[in] fd A POSIX-like file descriptor.
+ *
+ * @return The file descriptor table entry associated with file descriptor
+ *fd* or NULL if there is non.
+ */
+fd_t *fd_get(int fd);
+
+/**
+ * @brief Removes file descriptor table entry associated with *fd* from table.
+ *
+ * @param[in] fd A POSIX-like file descriptor.
+ */
+void fd_destroy(int fd);
+
+#endif /* FD_H */
diff --git a/sys/posix/fd.c b/sys/posix/fd.c
new file mode 100644
index 0000000000..6029826c7d
--- /dev/null
+++ b/sys/posix/fd.c
@@ -0,0 +1,99 @@
+/*
+ * Copyright (C) 2013 Freie Universität Berlin
+ *
+ * This file subject to the terms and conditions of the GNU Lesser General
+ * Public License. See the file LICENSE in the top level directory for more
+ * details.
+ */
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "posix_io.h"
+#include "board_uart0.h"
+#include "unistd.h"
+
+#include "fd.h"
+
+#if BOARD == MSB-430
+#define FD_MAX 5
+#else
+#define FD_MAX 15
+#endif
+
+static fd_t fd_table[FD_MAX];
+
+int fd_init(void)
+{
+ memset(fd_table, 0, sizeof(fd_t) * FD_MAX);
+
+ posix_open(uart0_handler_pid, 0);
+ fd_t fd = {
+ .__active = 1,
+ .fd = uart0_handler_pid,
+ .read = (ssize_t ( *)(int, void *, size_t))posix_read,
+ .write = (ssize_t ( *)(int, const void *, size_t))posix_write,
+ .close = posix_close
+ };
+ memcpy(&fd_table[STDIN_FILENO], &fd, sizeof(fd_t));
+ memcpy(&fd_table[STDOUT_FILENO], &fd, sizeof(fd_t));
+ memcpy(&fd_table[STDERR_FILENO], &fd, sizeof(fd_t));
+ return FD_MAX;
+}
+
+static int fd_get_next_free(void)
+{
+ for (int i = 0; i < FD_MAX; i++) {
+ fd_t *cur = &fd_table[i];
+
+ if (!cur->__active) {
+ return i;
+ }
+ }
+
+ return -1;
+}
+
+int fd_new(int internal_fd, ssize_t (*internal_read)(int, void *, size_t),
+ ssize_t (*internal_write)(int, const void *, size_t),
+ int (*internal_close)(int))
+{
+ int fd = fd_get_next_free();
+
+ if (fd >= 0) {
+ fd_t *fd_s = fd_get(fd);
+ fd_s->__active = 1;
+ fd_s->fd = internal_fd;
+ fd_s->read = internal_read;
+ fd_s->write = internal_write;
+ fd_s->close = internal_close;
+ }
+ else {
+ errno = ENFILE;
+ return -1;
+ }
+
+ return fd;
+}
+
+fd_t *fd_get(int fd)
+{
+ if (fd >= 0 && fd < FD_MAX) {
+ return &fd_table[fd];
+ }
+
+ return NULL;
+}
+
+void fd_destroy(int fd)
+{
+ fd_t *cur = fd_get(fd);
+
+ if (!cur) {
+ return;
+ }
+
+ memset(cur, 0, sizeof(fd_t));
+}
--
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