libc: handle 'O_APPEND' flag for 'open()'

Fixes #319.

libports/src/lib/libc/file_operations.cc

@@ -813,8 +813,15 @@ extern "C" int unlink(const char *path)
 }
 
 
-extern "C" ssize_t _write(int libc_fd, const void *buf, ::size_t count) {
+extern "C" ssize_t _write(int libc_fd, const void *buf, ::size_t count)
-	FD_FUNC_WRAPPER(write, libc_fd, buf, count); }
+{
+	int flags = fcntl(libc_fd, F_GETFL);
+
+	if ((flags != -1) && (flags & O_APPEND))
+		lseek(libc_fd, 0, SEEK_END);
+
+	FD_FUNC_WRAPPER(write, libc_fd, buf, count);
+}
 
 
 extern "C" ssize_t write(int libc_fd, const void *buf, ::size_t count) {

libports/src/lib/libc_ffat/plugin.cc

@@ -51,10 +51,13 @@ class Plugin_context : public Libc::Plugin_context
 	private:
 
 		char *_filename; /* needed for fstat() */
+		int   _fd_flags;
+		int   _status_flags;
 
 	public:
 
 		Plugin_context(const char *filename)
+		: _fd_flags(0), _status_flags(0)
 		{
 			if (verbose)
 				PDBG("new context at %p", this);
@@ -68,6 +71,18 @@ class Plugin_context : public Libc::Plugin_context
 		}
 
 		const char *filename() { return _filename; }
+
+		/**
+		 * Set/get file descriptor flags
+		 */
+		void fd_flags(int flags) { _fd_flags = flags; }
+		int fd_flags() { return _fd_flags; }
+
+		/**
+		 * Set/get file status status flags
+		 */
+		void status_flags(int flags) { _status_flags = flags; }
+		int status_flags() { return _status_flags; }
 };
 
 
@@ -242,12 +257,14 @@ class Plugin : public Libc::Plugin
 			}
 		}
 
-		int fcntl(Libc::File_descriptor *, int cmd, long arg)
+		int fcntl(Libc::File_descriptor *fd, int cmd, long arg)
 		{
-			/* libc's opendir() fails if fcntl() returns -1, so we return 0 here */
+			switch (cmd) {
-			if (verbose)
+				case F_GETFD: return context(fd)->fd_flags();
-				PDBG("fcntl() called - not yet implemented");
+				case F_SETFD: context(fd)->fd_flags(arg); return 0;
-			return 0;
+				case F_GETFL: return context(fd)->status_flags();
+				default: PERR("fcntl(): command %d not supported", cmd); return -1;
+			}
 		}
 
 		int fstat(Libc::File_descriptor *fd, struct stat *buf)
@@ -478,6 +495,7 @@ class Plugin : public Libc::Plugin
 				case FR_OK: {
 					Plugin_context *context = new (Genode::env()->heap())
 						File_plugin_context(pathname, ffat_file);
+					context->status_flags(flags);
 					Libc::File_descriptor *fd = Libc::file_descriptor_allocator()->alloc(this, context);
 					if ((flags & O_TRUNC) && (ftruncate(fd, 0) == -1))
 						return 0;
@@ -497,6 +515,7 @@ class Plugin : public Libc::Plugin
 						case FR_OK: {
 							Plugin_context *context = new (Genode::env()->heap())
 								Directory_plugin_context(pathname, ffat_dir);
+							context->status_flags(flags);
 							Libc::File_descriptor *f =
 								Libc::file_descriptor_allocator()->alloc(this, context);
 							if (verbose)

libports/src/lib/libc_fs/plugin.cc

@@ -76,6 +76,9 @@ class Plugin_context : public Libc::Plugin_context,
 
 		File_system::Node_handle _node_handle;
 
+		int _fd_flags;
+		int _status_flags;
+
 		/**
 		 * Current file position if manually seeked, or ~0 for append mode
 		 */
@@ -86,16 +89,31 @@ class Plugin_context : public Libc::Plugin_context,
 		bool in_flight;
 
 		Plugin_context(File_system::File_handle handle)
-		: _type(TYPE_FILE), _node_handle(handle), _seek_offset(~0), in_flight(false) { }
+		: _type(TYPE_FILE), _node_handle(handle), _fd_flags(0),
+		  _status_flags(0), _seek_offset(~0), in_flight(false) { }
 
 		Plugin_context(File_system::Dir_handle handle)
-		: _type(TYPE_DIR), _node_handle(handle), _seek_offset(0), in_flight(false) { }
+		: _type(TYPE_DIR), _node_handle(handle), _fd_flags(0),
+		  _status_flags(0), _seek_offset(0), in_flight(false) { }
 
 		Plugin_context(File_system::Symlink_handle handle)
-		: _type(TYPE_SYMLINK), _node_handle(handle), _seek_offset(~0), in_flight(false) { }
+		: _type(TYPE_SYMLINK), _node_handle(handle), _fd_flags(0),
+		  _status_flags(0), _seek_offset(~0), in_flight(false) { }
 
 		File_system::Node_handle node_handle() const { return _node_handle; }
 
+		/**
+		 * Set/get file descriptor flags
+		 */
+		void fd_flags(int flags) { _fd_flags = flags; }
+		int fd_flags() { return _fd_flags; }
+
+		/**
+		 * Set/get file status status flags
+		 */
+		void status_flags(int flags) { _status_flags = flags; }
+		int status_flags() { return _status_flags; }
+
 		/**
 		 * Return true of handle is append mode
 		 */
@@ -284,12 +302,14 @@ class Plugin : public Libc::Plugin
 			return 0;
 		}
 
-		int fcntl(Libc::File_descriptor *, int cmd, long arg)
+		int fcntl(Libc::File_descriptor *fd, int cmd, long arg)
 		{
-			/* libc's opendir() fails if fcntl() returns -1, so we return 0 here */
+			switch (cmd) {
-			if (verbose)
+				case F_GETFD: return context(fd)->fd_flags();
-				PDBG("fcntl() called - not yet implemented");
+				case F_SETFD: context(fd)->fd_flags(arg); return 0;
-			return 0;
+				case F_GETFL: return context(fd)->status_flags();
+				default: PERR("fcntl(): command %d not supported", cmd); return -1;
+			}
 		}
 
 		int fstat(Libc::File_descriptor *fd, struct stat *buf)
@@ -506,6 +526,8 @@ class Plugin : public Libc::Plugin
 				Plugin_context *context = new (Genode::env()->heap())
 					Plugin_context(handle);
 
+				context->status_flags(flags);
+
 				Libc::File_descriptor *fd = Libc::file_descriptor_allocator()->alloc(this, context);
 				if ((flags & O_TRUNC) && (ftruncate(fd, 0) == -1))
 					return 0;

libports/src/lib/libc_log/plugin.cc

@@ -20,6 +20,7 @@
 
 /* libc includes */
 #include <errno.h>
+#include <fcntl.h>
 #include <string.h>
 
 /* interface to 'log_console' */
@@ -51,6 +52,14 @@ namespace {
 				_stderr(Libc::file_descriptor_allocator()->alloc(this, &_context, 2))
 			{ }
 
+			int fcntl(Libc::File_descriptor *fd, int cmd, long arg)
+			{
+				switch (cmd) {
+					case F_GETFL: return O_WRONLY;
+					default: PERR("fcntl(): command %d not supported", cmd); return -1;
+				}
+			}
+
 			/*
 			 * We provide fstat here because printf inqueries _fstat about stdout
 			 */

libports/src/lib/libc_terminal/plugin.cc

@@ -17,6 +17,7 @@
 
 /* libc includes */
 #include <errno.h>
+#include <fcntl.h>
 #include <string.h>
 #include <termios.h>
 
@@ -99,12 +100,25 @@ namespace {
 	 * notifications about data available for reading are delivered to
 	 * the 'Read_sigh' thread, which cares about unblocking 'select()'.
 	 */
-	struct Plugin_context : Libc::Plugin_context, Terminal::Connection
+	class Plugin_context : public Libc::Plugin_context, public Terminal::Connection
 	{
-		Plugin_context()
+		private:
-		{
+
-			read_avail_sigh(read_sigh());
+			int _status_flags;
-		}
+
+		public:
+
+			Plugin_context()
+			: _status_flags(0)
+			{
+				read_avail_sigh(read_sigh());
+			}
+
+			/**
+			 * Set/get file status status flags
+			 */
+			void status_flags(int flags) { _status_flags = flags; }
+			int status_flags() { return _status_flags; }
 	};
 
 
@@ -145,6 +159,7 @@ namespace {
 			Libc::File_descriptor *open(const char *pathname, int flags)
 			{
 				Plugin_context *context = new (Genode::env()->heap()) Plugin_context;
+				context->status_flags(flags);
 				return Libc::file_descriptor_allocator()->alloc(this, context);
 			}
 
@@ -275,10 +290,13 @@ namespace {
 				}
 			}
 
-			/**
+			int fcntl(Libc::File_descriptor *fd, int cmd, long arg)
-			 * Suppress dummy message of the default plugin function
+			{
-			 */
+				switch (cmd) {
-			int fcntl(Libc::File_descriptor *, int cmd, long arg) { return -1; }
+					case F_GETFL: return context(fd)->status_flags();
+					default: PERR("fcntl(): command %d not supported", cmd); return -1;
+				}
+			}
 
 			int ioctl(Libc::File_descriptor *, int request, char *argp)
 			{

ports/src/lib/libc_noux/plugin.cc

@@ -1074,12 +1074,14 @@ namespace {
 			break;
 
 		case F_GETFL:
-			PINF("fcntl: F_GETFL for libc_fd=%d", fd->libc_fd);
+			if (verbose)
+				PINF("fcntl: F_GETFL for libc_fd=%d", fd->libc_fd);
 			sysio()->fcntl_in.cmd = Noux::Sysio::FCNTL_CMD_GET_FILE_STATUS_FLAGS;
 			break;
 
 		case F_SETFL:
-			PINF("fcntl: F_SETFL for libc_fd=%d", fd->libc_fd);
+			if (verbose)
+				PINF("fcntl: F_SETFL for libc_fd=%d", fd->libc_fd);
 			sysio()->fcntl_in.cmd      = Noux::Sysio::FCNTL_CMD_SET_FILE_STATUS_FLAGS;
 			sysio()->fcntl_in.long_arg = arg;
 			break;