1 files changed, 196 insertions, 0 deletions
diff --git a/lib/sqfs/src/unix/io_file.c b/lib/sqfs/src/unix/io_file.c
new file mode 100644
index 0000000..e1fb9db
--- /dev/null
+++ b/lib/sqfs/src/unix/io_file.c
@@ -0,0 +1,196 @@
+/* SPDX-License-Identifier: LGPL-3.0-or-later */
+/*
+ * io_file.c
+ *
+ * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ */
+#define SQFS_BUILDING_DLL
+#include "config.h"
+
+#include "sqfs/io.h"
+#include "sqfs/error.h"
+
+#include <sys/stat.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <errno.h>
+#include <fcntl.h>
+
+
+typedef struct {
+	sqfs_file_t base;
+
+	bool readonly;
+	sqfs_u64 size;
+	int fd;
+} sqfs_file_stdio_t;
+
+
+static void stdio_destroy(sqfs_object_t *base)
+{
+	sqfs_file_stdio_t *file = (sqfs_file_stdio_t *)base;
+
+	close(file->fd);
+	free(file);
+}
+
+static sqfs_object_t *stdio_copy(const sqfs_object_t *base)
+{
+	const sqfs_file_stdio_t *file = (const sqfs_file_stdio_t *)base;
+	sqfs_file_stdio_t *copy;
+	int err;
+
+	if (!file->readonly) {
+		errno = ENOTSUP;
+		return NULL;
+	}
+
+	copy = calloc(1, sizeof(*copy));
+	if (copy == NULL)
+		return NULL;
+
+	memcpy(copy, file, sizeof(*file));
+
+	copy->fd = dup(file->fd);
+	if (copy->fd < 0) {
+		err = errno;
+		free(copy);
+		copy = NULL;
+		errno = err;
+	}
+
+	return (sqfs_object_t *)copy;
+}
+
+static int stdio_read_at(sqfs_file_t *base, sqfs_u64 offset,
+			 void *buffer, size_t size)
+{
+	sqfs_file_stdio_t *file = (sqfs_file_stdio_t *)base;
+	ssize_t ret;
+
+	while (size > 0) {
+		ret = pread(file->fd, buffer, size, offset);
+
+		if (ret < 0) {
+			if (errno == EINTR)
+				continue;
+			return SQFS_ERROR_IO;
+		}
+
+		if (ret == 0)
+			return SQFS_ERROR_OUT_OF_BOUNDS;
+
+		buffer = (char *)buffer + ret;
+		size -= ret;
+		offset += ret;
+	}
+
+	return 0;
+}
+
+static int stdio_write_at(sqfs_file_t *base, sqfs_u64 offset,
+			  const void *buffer, size_t size)
+{
+	sqfs_file_stdio_t *file = (sqfs_file_stdio_t *)base;
+	ssize_t ret;
+
+	while (size > 0) {
+		ret = pwrite(file->fd, buffer, size, offset);
+
+		if (ret < 0) {
+			if (errno == EINTR)
+				continue;
+			return SQFS_ERROR_IO;
+		}
+
+		if (ret == 0)
+			return SQFS_ERROR_OUT_OF_BOUNDS;
+
+		buffer = (const char *)buffer + ret;
+		size -= ret;
+		offset += ret;
+	}
+
+	if (offset >= file->size)
+		file->size = offset;
+
+	return 0;
+}
+
+static sqfs_u64 stdio_get_size(const sqfs_file_t *base)
+{
+	const sqfs_file_stdio_t *file = (const sqfs_file_stdio_t *)base;
+
+	return file->size;
+}
+
+static int stdio_truncate(sqfs_file_t *base, sqfs_u64 size)
+{
+	sqfs_file_stdio_t *file = (sqfs_file_stdio_t *)base;
+
+	if (ftruncate(file->fd, size))
+		return SQFS_ERROR_IO;
+
+	file->size = size;
+	return 0;
+}
+
+
+sqfs_file_t *sqfs_open_file(const char *filename, sqfs_u32 flags)
+{
+	sqfs_file_stdio_t *file;
+	int open_mode, temp;
+	sqfs_file_t *base;
+	struct stat sb;
+
+	if (flags & ~SQFS_FILE_OPEN_ALL_FLAGS) {
+		errno = EINVAL;
+		return NULL;
+	}
+
+	file = calloc(1, sizeof(*file));
+	base = (sqfs_file_t *)file;
+	if (file == NULL)
+		return NULL;
+
+	sqfs_object_init(file, stdio_destroy, stdio_copy);
+
+	if (flags & SQFS_FILE_OPEN_READ_ONLY) {
+		file->readonly = true;
+		open_mode = O_RDONLY;
+	} else {
+		file->readonly = false;
+		open_mode = O_CREAT | O_RDWR;
+
+		if (flags & SQFS_FILE_OPEN_OVERWRITE) {
+			open_mode |= O_TRUNC;
+		} else {
+			open_mode |= O_EXCL;
+		}
+	}
+
+	file->fd = open(filename, open_mode, 0644);
+	if (file->fd < 0) {
+		temp = errno;
+		free(file);
+		errno = temp;
+		return NULL;
+	}
+
+	if (fstat(file->fd, &sb)) {
+		temp = errno;
+		close(file->fd);
+		free(file);
+		errno = temp;
+		return NULL;
+	}
+
+	file->size = sb.st_size;
+
+	base->read_at = stdio_read_at;
+	base->write_at = stdio_write_at;
+	base->get_size = stdio_get_size;
+	base->truncate = stdio_truncate;
+	return base;
+}