Experimental virtual file support

QuRT does not have a filesystem, so creating a virtual filesystem
that could be implemented as an in-memory file or a remote file
over fastRPC.

Signed-off-by: Mark Charlebois <charlebm@gmail.com>

Tools/posix_apps.py

@@ -61,6 +61,7 @@ for app in apps:
 print """
 static int shutdown_main(int argc, char *argv[]);
 static int list_tasks_main(int argc, char *argv[]);
+static int list_files_main(int argc, char *argv[]);
 static int list_devices_main(int argc, char *argv[]);
 static int list_topics_main(int argc, char *argv[]);
 }
@@ -77,6 +78,7 @@ for app in apps:
 
 print '\tapps["shutdown"] = shutdown_main;'
 print '\tapps["list_tasks"] = list_tasks_main;'
+print '\tapps["list_files"] = list_files_main;'
 print '\tapps["list_devices"] = list_devices_main;'
 print '\tapps["list_topics"] = list_topics_main;'
 print """
@@ -115,5 +117,10 @@ static int list_topics_main(int argc, char *argv[])
 	px4_show_topics();
 	return 0;
 }
+static int list_files_main(int argc, char *argv[])
+{
+	px4_show_files();
+	return 0;
+}
 """
 

src/drivers/device/module.mk

@@ -47,6 +47,7 @@ else
 SRCS =		  \
 		  device_posix.cpp \
 		  vdev.cpp \
+		  vfile.cpp \
 		  vdev_posix.cpp \
 		  i2c_posix.cpp  \
 		  sim.cpp \

src/drivers/device/vdev.cpp

@@ -64,7 +64,7 @@ private:
 	px4_dev_t() {}
 };
 
-#define PX4_MAX_DEV 100
+#define PX4_MAX_DEV 30
 static px4_dev_t *devmap[PX4_MAX_DEV];
 
 /*
@@ -448,8 +448,12 @@ VDev::remove_poll_waiter(px4_pollfd_struct_t *fds)
 
 VDev *VDev::getDev(const char *path)
 {
+	printf("VDev::getDev\n");
 	int i=0;
 	for (; i<PX4_MAX_DEV; ++i) {
+		if (devmap[i]) {
+			printf("%s %s\n", devmap[i]->name, path);
+		}
 		if (devmap[i] && (strcmp(devmap[i]->name, path) == 0)) {
 			return (VDev *)(devmap[i]->cdev);
 		}
@@ -479,6 +483,18 @@ void VDev::showTopics()
 	}
 }
 
+void VDev::showFiles()
+{
+	int i=0;
+	printf("Files:\n");
+	for (; i<PX4_MAX_DEV; ++i) {
+		if (devmap[i] && strncmp(devmap[i]->name, "/obj/", 5) != 0 &&
+				 strncmp(devmap[i]->name, "/dev/", 5) != 0) {
+			printf("   %s\n", devmap[i]->name);
+		}
+	}
+}
+
 const char *VDev::topicList(unsigned int *next)
 {
 	for (;*next<PX4_MAX_DEV; (*next)++)

src/drivers/device/vdev.h

@@ -60,6 +60,7 @@ namespace device __EXPORT
 struct file_t {
 	int fd;
 	int flags;
+	mode_t mode;
 	void *priv;
 	void *vdev;
 
@@ -330,6 +331,7 @@ public:
 	virtual int	ioctl(file_t *filep, int cmd, unsigned long arg);
 
 	static VDev *getDev(const char *path);
+	static void showFiles(void);
 	static void showDevices(void);
 	static void showTopics(void);
 	static const char *devList(unsigned int *next);

src/drivers/device/vdev_posix.cpp

@@ -40,6 +40,7 @@
 #include <px4_posix.h>
 #include <px4_time.h>
 #include "device.h"
+#include "vfile.h"
 
 #include <stdlib.h>
 #include <stdio.h>
@@ -85,16 +86,26 @@ inline bool valid_fd(int fd)
 	return (fd < PX4_MAX_FD && fd >= 0 && filemap[fd] != NULL);
 }
 
-int px4_open(const char *path, int flags)
+int px4_open(const char *path, int flags, ...)
 {
+	printf("px4_open\n");
 	VDev *dev = VDev::getDev(path);
 	int ret = 0;
 	int i;
+	mode_t mode;
 
-	if (!dev) {
+	if (!dev && (flags & (PX4_F_WRONLY|PX4_F_CREAT)) != 0)
-		ret = -EINVAL;
+	{
+		va_list p;
+		va_start(p, flags);
+ 		mode = va_arg(p, mode_t);
+		va_end(p);
+
+		// Create the file
+		warnx("Creating virtual file %s\n", path);
+		dev = VFile::createFile(path, mode);
 	}
-	else {
+	if (dev) {
 		for (i=0; i<PX4_MAX_FD; ++i) {
 			if (filemap[i] == 0) {
 				filemap[i] = new device::file_t(flags,dev,i);
@@ -108,6 +119,9 @@ int px4_open(const char *path, int flags)
 			ret = -ENOENT;
 		}
 	}
+	else {
+		ret = -EINVAL;
+	}
 	if (ret < 0) {
 		px4_errno = -ret;
 		return -1;
@@ -272,6 +286,11 @@ cleanup:
 	return count;
 }
 
+int px4_fsync(int fd)
+{
+	return 0;
+}
+
 void px4_show_devices()
 {
 	VDev::showDevices();
@@ -282,6 +301,11 @@ void px4_show_topics()
 	VDev::showTopics();
 }
 
+void px4_show_files()
+{
+	VDev::showFiles();
+}
+
 const char * px4_get_device_names(unsigned int *handle)
 {
 	return VDev::devList(handle);

src/drivers/device/vfile.cpp

@@ -0,0 +1,65 @@
+/****************************************************************************
+ *
+ *   Copyright (C) 2015 Mark Charlebois. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name PX4 nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/**
+ * @file vdev_file.cpp
+ * Virtual file
+ *
+ * @author Mark Charlebois <charlebm@gmail.com>
+ */
+
+#include "vfile.h"
+#include <stdio.h>
+
+using namespace device;
+
+VFile::VFile(const char *fname, mode_t mode) :
+	VDev("vfile", fname)
+{
+}
+
+VFile * VFile::createFile(const char *fname, mode_t mode)
+{
+	VFile *me = new VFile(fname, mode);
+	me->register_driver(fname, me);
+	return me;
+}
+
+ssize_t VFile::write(device::file_t *handlep, const char *buffer, size_t buflen)
+{
+	// ignore what was written, but let pollers know something was written
+	poll_notify(POLLIN);
+
+	return buflen;
+}
+

src/drivers/device/vfile.h

@@ -0,0 +1,58 @@
+/****************************************************************************
+ *
+ *   Copyright (C) 2015 Mark Charlebois. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name PX4 nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/**
+ * @file vfile.cpp
+ * Virtual file
+ *
+ * @author Mark Charlebois <charlebm@gmail.com>
+ */
+
+#include <px4_tasks.h>
+#include <drivers/drv_device.h>
+#include "device.h"
+#include <unistd.h>
+#include <stdio.h>
+
+class VFile : public device::VDev {
+public:
+
+	static VFile *createFile(const char *fname, mode_t mode);
+	~VFile() {}
+
+	virtual ssize_t write(device::file_t *handlep, const char *buffer, size_t buflen);
+
+private:
+	VFile(const char *fname, mode_t mode);
+	VFile(const VFile &);
+};

src/modules/systemlib/bson/tinybson.c

@@ -37,6 +37,7 @@
  * A simple subset SAX-style BSON parser and generator.
  */
 
+#include <px4_posix.h>
 #include <unistd.h>
 #include <string.h>
 #include <stdlib.h>
@@ -59,7 +60,7 @@ read_x(bson_decoder_t decoder, void *p, size_t s)
 	CODER_CHECK(decoder);
 
 	if (decoder->fd > -1)
-		return (read(decoder->fd, p, s) == (int)s) ? 0 : -1;
+		return (px4_read(decoder->fd, p, s) == (int)s) ? 0 : -1;
 
 	if (decoder->buf != NULL) {
 		/* staged operations to avoid integer overflow for corrupt data */
@@ -301,7 +302,7 @@ write_x(bson_encoder_t encoder, const void *p, size_t s)
 	CODER_CHECK(encoder);
 
 	if (encoder->fd > -1)
-		return (write(encoder->fd, p, s) == (int)s) ? 0 : -1;
+		return (px4_write(encoder->fd, p, s) == (int)s) ? 0 : -1;
 
 	/* do we need to extend the buffer? */
 	while ((encoder->bufpos + s) > encoder->bufsize) {
@@ -408,7 +409,7 @@ bson_encoder_fini(bson_encoder_t encoder)
 	}
 
 	/* sync file */
-	fsync(encoder->fd);
+	px4_fsync(encoder->fd);
 
 	return 0;
 }

src/modules/systemlib/param/param.c

@@ -43,6 +43,7 @@
 
 //#include <debug.h>
 #include <px4_defines.h>
+#include <px4_posix.h>
 #include <string.h>
 #include <stdbool.h>
 #include <fcntl.h>
@@ -684,7 +685,7 @@ param_save_default(void)
 	const char *filename = param_get_default_file();
 
 	/* write parameters to temp file */
-	fd = open(filename, O_WRONLY | O_CREAT, 0x777);
+	fd = px4_open(filename, O_WRONLY | O_CREAT, 0x777);
 
 	if (fd < 0) {
 		warn("failed to open param file: %s", filename);
@@ -697,7 +698,7 @@ param_save_default(void)
 		warnx("failed to write parameters to file: %s", filename);
 	}
 
-	close(fd);
+	px4_close(fd);
 
 	return res;
 }
@@ -708,7 +709,8 @@ param_save_default(void)
 int
 param_load_default(void)
 {
-	int fd_load = open(param_get_default_file(), O_RDONLY);
+	warnx("param_load_default\n");
+	int fd_load = px4_open(param_get_default_file(), O_RDONLY);
 
 	if (fd_load < 0) {
 		/* no parameter file is OK, otherwise this is an error */
@@ -720,7 +722,7 @@ param_load_default(void)
 	}
 
 	int result = param_load(fd_load);
-	close(fd_load);
+	px4_close(fd_load);
 
 	if (result != 0) {
 		warn("error reading parameters from '%s'", param_get_default_file());

src/platforms/px4_posix.h

@@ -43,14 +43,16 @@
 #include <stdint.h>
 #include <sys/types.h>
 #include <unistd.h>
+#include <fcntl.h>
 #include <poll.h>
 #include <semaphore.h>
 
-#define  PX4_F_RDONLY 1
-#define  PX4_F_WRONLY 2
 
 #ifdef __PX4_NUTTX
 
+#define  PX4_F_RDONLY 1
+#define  PX4_F_WRONLY 2
+
 typedef struct pollfd px4_pollfd_struct_t;
 
 #if defined(__cplusplus)
@@ -64,11 +66,13 @@ typedef struct pollfd px4_pollfd_struct_t;
 #define px4_write 	_GLOBAL write
 #define px4_read 	_GLOBAL read
 #define px4_poll 	_GLOBAL poll
+#define px4_fsync 	_GLOBAL fsync
 
 #elif defined(__PX4_POSIX)
 
-#define  PX4_F_RDONLY 1
+#define  PX4_F_RDONLY O_RDONLY
-#define  PX4_F_WRONLY 2
+#define  PX4_F_WRONLY O_WRONLY
+#define  PX4_F_CREAT  O_CREAT
 
 typedef short pollevent_t;
 
@@ -85,12 +89,13 @@ typedef struct {
 
 __BEGIN_DECLS
 
-__EXPORT int 		px4_open(const char *path, int flags);
+__EXPORT int 		px4_open(const char *path, int flags, ...);
 __EXPORT int 		px4_close(int fd);
 __EXPORT ssize_t	px4_read(int fd, void *buffer, size_t buflen);
 __EXPORT ssize_t	px4_write(int fd, const void *buffer, size_t buflen);
 __EXPORT int		px4_ioctl(int fd, int cmd, unsigned long arg);
 __EXPORT int		px4_poll(px4_pollfd_struct_t *fds, nfds_t nfds, int timeout);
+__EXPORT int		px4_fsync(int fd);
 
 __END_DECLS
 #else
@@ -101,6 +106,7 @@ __BEGIN_DECLS
 extern int px4_errno;
 
 __EXPORT void		px4_show_devices(void);
+__EXPORT void		px4_show_files(void);
 __EXPORT const char *	px4_get_device_names(unsigned int *handle);
 
 __EXPORT void		px4_show_topics(void);

src/systemcmds/param/param.c

@@ -40,6 +40,7 @@
  */
 
 #include <px4_config.h>
+#include <px4_posix.h>
 
 #include <stdio.h>
 #include <stdlib.h>
@@ -182,7 +183,7 @@ static int
 do_save(const char *param_file_name)
 {
 	/* create the file */
-	int fd = open(param_file_name, O_WRONLY | O_CREAT, 0x777);
+	int fd = px4_open(param_file_name, O_WRONLY | O_CREAT, 0x777);
 
 	if (fd < 0) {
 		warn("opening '%s' failed", param_file_name);
@@ -190,7 +191,7 @@ do_save(const char *param_file_name)
 	}
 
 	int result = param_export(fd, false);
-	close(fd);
+	px4_close(fd);
 
 	if (result < 0) {
 		(void)unlink(param_file_name);
@@ -204,7 +205,7 @@ do_save(const char *param_file_name)
 static int
 do_load(const char *param_file_name)
 {
-	int fd = open(param_file_name, O_RDONLY);
+	int fd = px4_open(param_file_name, O_RDONLY);
 
 	if (fd < 0) {
 		warn("open '%s'", param_file_name);
@@ -212,7 +213,7 @@ do_load(const char *param_file_name)
 	}
 
 	int result = param_load(fd);
-	close(fd);
+	px4_close(fd);
 
 	if (result < 0) {
 		warnx("error importing from '%s'", param_file_name);
@@ -225,7 +226,7 @@ do_load(const char *param_file_name)
 static int
 do_import(const char *param_file_name)
 {
-	int fd = open(param_file_name, O_RDONLY);
+	int fd = px4_open(param_file_name, O_RDONLY);
 
 	if (fd < 0) {
 		warn("open '%s'", param_file_name);
@@ -233,7 +234,7 @@ do_import(const char *param_file_name)
 	}
 
 	int result = param_import(fd);
-	close(fd);
+	px4_close(fd);
 
 	if (result < 0) {
 		warnx("error importing from '%s'", param_file_name);