[DFS] Support 9PFS

What is 9PFS (https://en.wikipedia.org/wiki/9P_(protocol)):
9P (or the Plan 9 Filesystem Protocol or Styx) is a network protocol developed for the Plan 9 from Bell Labs distributed operating system as the means of connecting the components of a Plan 9 system. Files are key objects in Plan 9. They represent windows, network connections, processes, and almost anything else available in the operating system.

rt-thread could share filesystem in VM mode with 9pfs such as QEMU...

Signed-off-by: GuEe-GUI <2991707448@qq.com>

components/dfs/Kconfig

@@ -163,6 +163,12 @@ endif
         default y
 
 if RT_USING_DFS_V1
+    config RT_USING_DFS_9PFS
+        bool "Using Plan 9 remote filesystem"
+        select RT_USING_ADT_BITMAP
+        depends on RT_USING_MEMHEAP
+        default n
+
     config RT_USING_DFS_ISO9660
         bool "Using ISO9660 filesystem"
         depends on RT_USING_MEMHEAP

components/dfs/dfs_v1/filesystems/9pfs/SConscript

@@ -0,0 +1,11 @@
+# RT-Thread building script for component
+
+from building import *
+
+cwd = GetCurrentDir()
+src = Glob('*.c')
+CPPPATH = [cwd]
+
+group = DefineGroup('Filesystem', src, depend = ['RT_USING_DFS', 'RT_USING_DFS_9PFS'], CPPPATH = CPPPATH)
+
+Return('group')

components/dfs/dfs_v1/filesystems/9pfs/dfs_9pfs.h

@@ -0,0 +1,247 @@
+/*
+ * Copyright (c) 2006-2023, RT-Thread Development Team
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Change Logs:
+ * Date           Author       Notes
+ * 2023-02-25     GuEe-GUI     the first version
+ */
+
+#ifndef __DFS_9PFS_H__
+#define __DFS_9PFS_H__
+
+#include <rtdef.h>
+
+#include <dfs.h>
+#include <dfs_fs.h>
+#include <dfs_file.h>
+#include <bitmap.h>
+
+#define P9_ERROR                    -1
+#define P9_UNKNOWN_VERSION          -2
+#define P9_R_ERROR                  -3
+#define P9_MSG_TOO_LONG             -4
+#define P9_UNEXPECTED_MSG           -5
+#define P9_UNEXPECTED_TAG           -6
+#define P9_TRANSPORT_ERROR          -7
+#define P9_NO_TRANSPORT             -8
+#define P9_NULL_PATH                -9
+#define P9_PATH_ELEMENT_TOO_LONG    -10
+#define P9_READ_UNEXPECTED_DATA     -11
+#define P9_NO_BUFFER                -12
+#define P9_MSG_SIZE_TOO_BIG         -13
+
+#define P9_PARTIAL_WALK             1
+
+#define P9_VERSION                  "9P2000.u"
+#define P9_VERSION_UNKNOWN          "unknown"
+
+#define P9_MSG_F_TYPE               7
+#define P9_MSG_F_BSIZE              11
+#define P9_MSG_F_BLOCKS             15
+#define P9_MSG_F_BFREE              23
+#define P9_MSG_F_BAVAIL             31
+#define P9_MSG_F_FILES              39
+#define P9_MSG_F_FFREE              47
+#define P9_MSG_FSID_VAL             55
+#define P9_MSG_F_NAMELEN            63
+#define P9_MSG_SIZE                 0
+#define P9_MSG_ID                   4
+#define P9_MSG_ERR                  0x6b
+#define P9_MSG_ERR_STR              9
+#define P9_MSG_ERR_STR_LEN          7
+#define P9_MSG_TAG                  5
+#define P9_MSG_VER_MSIZE            7
+#define P9_MSG_VER_STR_LEN          11
+#define P9_MSG_VER_STR              13
+#define P9_MSG_WALK_TX_ELMT         15
+#define P9_MSG_WALK_RX_ELMT         7
+#define P9_MSG_WALK_MAX_ELMT        16
+#define P9_MSG_QID_SIZE             13
+#define P9_MSG_WALK_RX_HDR_SIZE     9
+#define P9_MSG_OPEN_IOUNIT          20
+#define P9_MSG_OPEN_MODE_MASK       0x5f
+#define P9_MSG_CREATE_IOUNIT        20
+#define P9_MSG_READ_COUNT           7
+#define P9_MSG_READ_DATA            11
+#define P9_MSG_WRITE_COUNT          7
+#define P9_MSG_WRITE_DATA           23
+#define P9_MSG_RENAME_DATA          15
+#define P9_MSG_STAT_SIZE            9
+#define P9_MSG_STAT_TYPE            11
+#define P9_MSG_STAT_DEV             13
+#define P9_MSG_STAT_QID_TYPE        17
+#define P9_MSG_STAT_QID_VERSION     18
+#define P9_MSG_STAT_QID_PATH        22
+#define P9_MSG_STAT_MODE            30
+#define P9_MSG_STAT_ATIME           34
+#define P9_MSG_STAT_MTIME           38
+#define P9_MSG_STAT_LEN             42
+#define P9_MSG_STAT_NAME_LEN        50
+#define P9_MSG_STAT_NAME            52
+
+#define P9_HD_TSTATFS               8
+#define P9_HD_RSTATFS               (P9_HD_TSTATFS + 1)
+#define P9_HD_TRENAME               20
+#define P9_HD_RRENAME               (P9_HD_TRENAME + 1)
+#define P9_HD_TFSYNC                50
+#define P9_HD_RFSYNC                (P9_HD_TFSYNC + 1)
+#define P9_HD_TVERSION              100
+#define P9_HD_RVERSION              (P9_HD_TVERSION + 1)
+#define P9_HD_TAUTH                 102
+#define P9_HD_RAUTH                 (P9_HD_TAUTH + 1)
+#define P9_HD_TATTACH               104
+#define P9_HD_RATTACH               (P9_HD_TATTACH + 1)
+#define P9_HD_TERROR                106
+#define P9_HD_RERROR                (P9_HD_TERROR + 1)
+#define P9_HD_TFLUSH                108
+#define P9_HD_RFLUSH                (P9_HD_TFLUSH + 1)
+#define P9_HD_TWALK                 110
+#define P9_HD_RWALK                 (P9_HD_TWALK + 1)
+#define P9_HD_TOPEN                 112
+#define P9_HD_ROPEN                 (P9_HD_TOPEN + 1)
+#define P9_HD_TCREATE               114
+#define P9_HD_RCREATE               (P9_HD_TCREATE + 1)
+#define P9_HD_TREAD                 116
+#define P9_HD_RREAD                 (P9_HD_TREAD + 1)
+#define P9_HD_TWRITE                118
+#define P9_HD_RWRITE                (P9_HD_TWRITE + 1)
+#define P9_HD_TCLUNK                120
+#define P9_HD_RCLUNK                (P9_HD_TCLUNK + 1)
+#define P9_HD_TREMOVE               122
+#define P9_HD_RREMOVE               (P9_HD_TREMOVE + 1)
+#define P9_HD_TSTAT                 124
+#define P9_HD_RSTAT                 (P9_HD_TSTAT + 1)
+
+#define P9_STAT_MODE_DIR            0x80000000
+#define P9_STAT_MODE_APPEND         0x40000000
+#define P9_STAT_MODE_EXCL           0x20000000
+#define P9_STAT_MODE_MOUNT          0x10000000
+#define P9_STAT_MODE_AUTH           0x08000000
+#define P9_STAT_MODE_TMP            0x04000000
+#define P9_STAT_MODE_SYMLINK        0x02000000
+#define P9_STAT_MODE_LINK           0x01000000
+#define P9_STAT_MODE_DEVICE         0x00800000
+#define P9_STAT_MODE_NAMED_PIPE     0x00200000
+#define P9_STAT_MODE_SOCKET         0x00100000
+#define P9_STAT_MODE_SETUID         0x00080000
+#define P9_STAT_MODE_SETGID         0x00040000
+#define P9_STAT_MODE_SETVTX         0x00010000
+
+struct p9_protocol
+{
+    rt_list_t list;
+    char *name;
+
+    const char *tag;
+    rt_err_t (*transport)(struct p9_protocol *p9p,
+            rt_uint8_t *tx_data, rt_uint32_t tx_size,
+            rt_uint8_t *rx_data, rt_uint32_t *ref_rx_size);
+};
+
+struct p9_connection
+{
+    char *uname;            /* User name */
+    char *aname;            /* Tree/mount name/path */
+    rt_uint32_t fid;        /* Represents mount point */
+    rt_uint32_t msg_size;
+
+    char error[200];
+    rt_uint8_t *rx_buffer;
+    rt_uint8_t *tx_buffer;
+    struct rt_mutex lock;
+
+    struct p9_protocol *protocol;
+    RT_BITMAP_DECLARE(fid_map, DFS_FD_MAX);
+};
+
+struct p9_file
+{
+#define P9_ROOT_FID     1
+#define P9_FILE_FID     2
+    rt_uint32_t fid;        /* Identifies the file to P9 server */
+    rt_uint32_t iounit;     /* Maximum read size in bytes */
+
+    struct p9_connection *connection;
+};
+
+/**
+ * @brief Allocate a new 9P connection.
+ *
+ * @param p9p Pointer to the 9P protocol structure.
+ * @param aname Mount name/path.
+ * @param buffer_size Size of the buffer to allocate.
+ * @return Pointer to the allocated p9_connection structure, or RT_NULL on failure.
+ */
+struct p9_connection *p9_connection_alloc(struct p9_protocol *p9p,
+        const char *aname, rt_uint32_t buffer_size);
+
+/**
+ * @brief Free a 9P connection and release its resources.
+ *
+ * @param conn Pointer to the p9_connection to free.
+ * @return RT_EOK on success, error code otherwise.
+ */
+rt_err_t p9_connection_free(struct p9_connection *conn);
+
+/**
+ * @brief Perform a 9P transaction.
+ *
+ * @param conn Pointer to the p9_connection.
+ * @param tx_size Size of the transmit buffer.
+ * @param out_rx_size Pointer to store the received buffer size.
+ * @return 0 on success, negative error code otherwise.
+ */
+int p9_transaction(struct p9_connection *conn,
+        rt_uint32_t tx_size, rt_uint32_t *out_rx_size);
+
+/**
+ * @brief Negotiate 9P protocol version with the server.
+ *
+ * @param conn Pointer to the p9_connection.
+ * @return 0 on success, negative error code otherwise.
+ */
+int p9_version(struct p9_connection *conn);
+
+/**
+ * @brief Attach to the 9P server.
+ *
+ * @param conn Pointer to the p9_connection.
+ * @return 0 on success, negative error code otherwise.
+ */
+int p9_attach(struct p9_connection *conn);
+
+/**
+ * @brief Clunk (close) a file identifier (fid) on the 9P server.
+ *
+ * @param conn Pointer to the p9_connection.
+ * @param fid File identifier to clunk.
+ * @return 0 on success, negative error code otherwise.
+ */
+int p9_clunk(struct p9_connection *conn, rt_uint32_t fid);
+
+/**
+ * @brief Register a 9P protocol tag.
+ *
+ * @param p9p Pointer to the p9_protocol structure.
+ * @return RT_EOK on success, error code otherwise.
+ */
+rt_err_t dfs_9pfs_add_tag(struct p9_protocol *p9p);
+
+/**
+ * @brief Unregister a 9P protocol tag.
+ *
+ * @param p9p Pointer to the p9_protocol structure.
+ * @return RT_EOK on success, error code otherwise.
+ */
+rt_err_t dfs_9pfs_del_tag(struct p9_protocol *p9p);
+
+/**
+ * @brief Initialize the 9P filesystem.
+ *
+ * @return 0 on success, negative error code otherwise.
+ */
+int dfs_9pfs_init(void);
+
+#endif /* __DFS_9PFS_H__ */

components/finsh/msh_file.c

@@ -585,7 +585,7 @@ static int cmd_mount(int argc, char **argv)
 
         /* mount a filesystem to the specified directory */
         rt_kprintf("mount device %s(%s) onto %s ... ", device, fstype, path);
-        if (rt_strcmp(fstype, "nfs") == 0)
+        if (rt_strcmp(fstype, "nfs") == 0 || rt_strcmp(fstype, "9p") == 0)
         {
             data = argv[1];
             device = 0;