Implementing..

1 files changed, 99 insertions, 21 deletions

diff --git a/src/fuse.c b/src/fuse.c
index a3c946d..9cfd2bf 100644
--- a/src/fuse.c
+++ b/src/fuse.c
@@ -7,6 +7,7 @@
 
 #include <spec.h>
 
+#include <assert.h>
 #include <errno.h>
 #include <fuse.h>
 #include <limits.h>
@@ -16,9 +17,11 @@
 #include <sys/time.h>
 #include <time.h>
 
-static char *image = 0;
+static FILE *image = NULL;
 
-static void marfs_debug(const char *fmt, ...)
+static struct marfs_header header = { 0 };
+
+static void debug(const char *fmt, ...)
 {
 	printf("\t>>> ");
 	va_list args;
@@ -28,9 +31,56 @@ static void marfs_debug(const char *fmt, ...)
 	printf("\n");
 }
 
+static void sector(u32 index, u32 size, void *buf)
+{
+	fseek(image, index * header.entry_size, SEEK_SET);
+	assert(fread(buf, 1, size, image) == size);
+}
+
+// first -> start = header.main.head
+static u8 read_entry_header(const char *path, u32 start, struct marfs_entry_header *entry_header)
+{
+	while (*path && *path == '/')
+		path++;
+
+	struct marfs_entry_header h;
+	sector(start, sizeof(h), &h);
+
+	if (h.type == MARFS_DIR_ENTRY) {
+		struct marfs_dir_entry entry;
+		sector(start, sizeof(entry), &entry);
+		assert(entry.count <= MARFS_DIR_ENTRY_COUNT);
+		for (u32 i = 0; i < entry.count; i++) {
+			struct marfs_dir_entry_data *data = &entry.entries[i];
+			if (!strncmp(path, data->name, data->length)) {
+				if (path[data->length] == '/') {
+					return read_entry_header(path, data->pointer.head,
+								 entry_header);
+				}
+				if (!path[data->length]) {
+					*entry_header = h;
+					return 1;
+				}
+			}
+		}
+
+		if (entry.header.next != MARFS_END)
+			return read_entry_header(path, entry.header.next, entry_header);
+	} else if (h.type == MARFS_FILE_ENTRY) {
+		*entry_header = h;
+		return 1;
+	}
+
+	return 0;
+}
+
+/**
+ * Fuse operations
+ */
+
 static void *marfs_init(struct fuse_conn_info *conn, struct fuse_config *cfg)
 {
-	marfs_debug("init()");
+	debug("init()");
 	UNUSED(conn);
 	cfg->kernel_cache = 1;
 	return NULL;
@@ -38,26 +88,28 @@ static void *marfs_init(struct fuse_conn_info *conn, struct fuse_config *cfg)
 
 static void marfs_destroy(void *data)
 {
-	marfs_debug("destroy()");
+	debug("destroy()");
+	UNUSED(data);
+
 	if (image)
-		free(image);
+		fclose(image);
 }
 
 static int marfs_open(const char *file_path, struct fuse_file_info *file_info)
 {
-	marfs_debug("open() on %s", file_path);
+	debug("open() on %s", file_path);
 	return 0;
 }
 
 static int marfs_opendir(const char *dir_path, struct fuse_file_info *file_info)
 {
-	marfs_debug("opendir() on %s", dir_path);
+	debug("opendir() on %s", dir_path);
 	return 0;
 }
 
 static int marfs_getattr(const char *path, struct stat *stat, struct fuse_file_info *info)
 {
-	marfs_debug("getattr() on %s", path);
+	debug("getattr() on %s", path);
 	UNUSED(info);
 
 	memset(stat, 0, sizeof(*stat));
@@ -76,7 +128,7 @@ static int marfs_getattr(const char *path, struct stat *stat, struct fuse_file_i
 static int marfs_readdir(const char *path, void *buf, fuse_fill_dir_t fill, off_t offset,
 			 struct fuse_file_info *file_info, enum fuse_readdir_flags flags)
 {
-	marfs_debug("readdir() on %s and offset %lu", path, offset);
+	debug("readdir() on %s and offset %lu", path, offset);
 
 	UNUSED(offset);
 	UNUSED(file_info);
@@ -93,70 +145,70 @@ static int marfs_readdir(const char *path, void *buf, fuse_fill_dir_t fill, off_
 
 static int marfs_release(const char *path, struct fuse_file_info *file_info)
 {
-	marfs_debug("release() on %s", path);
+	debug("release() on %s", path);
 	return 0;
 }
 
 static int marfs_releasedir(const char *path, struct fuse_file_info *file_info)
 {
-	marfs_debug("releasedir() on %s", path);
+	debug("releasedir() on %s", path);
 	return 0;
 }
 
 static int marfs_read(const char *path, char *buf, size_t to_read, off_t offset,
 		      struct fuse_file_info *file_info)
 {
-	marfs_debug("read() on %s, %lu", path, to_read);
+	debug("read() on %s, %lu", path, to_read);
 	return to_read;
 }
 
 static int marfs_write(const char *path, const char *buf, size_t to_write, off_t offset,
 		       struct fuse_file_info *file_info)
 {
-	marfs_debug("write() on %s", path);
+	debug("write() on %s", path);
 	return to_write;
 }
 
 static int marfs_create(const char *path, mode_t mode, struct fuse_file_info *file_info)
 {
-	marfs_debug("create() on %s", path);
+	debug("create() on %s", path);
 	return 0;
 }
 
 static int marfs_mkdir(const char *path, mode_t mode)
 {
-	marfs_debug("mkdir() on %s", path);
+	debug("mkdir() on %s", path);
 	return 0;
 }
 
 static int marfs_unlink(const char *path)
 {
-	marfs_debug("unlink() on %s", path);
+	debug("unlink() on %s", path);
 	return 0;
 }
 
 static int marfs_rmdir(const char *path)
 {
-	marfs_debug("rmdir() on %s", path);
+	debug("rmdir() on %s", path);
 	return 0;
 }
 
 static int marfs_utimens(const char *path, const struct timespec tv[2],
 			 struct fuse_file_info *file_info)
 {
-	marfs_debug("utimens() on %s", path);
+	debug("utimens() on %s", path);
 	return 0;
 }
 
 static int marfs_truncate(const char *path, off_t size, struct fuse_file_info *file_info)
 {
-	marfs_debug("truncate() on %s, size %lu", path, size);
+	debug("truncate() on %s, size %lu", path, size);
 	return 0;
 }
 
 static int marfs_rename(const char *path, const char *new, unsigned int flags)
 {
-	marfs_debug("rename() on %s -> %s", path, new);
+	debug("rename() on %s -> %s", path, new);
 	return 0;
 }
 
@@ -188,10 +240,36 @@ int main(int argc, char **argv)
 	}
 
 	// I don't think that's how fuse is supposed to work but idc
-	image = strdup(argv[1]);
+	char *path = argv[1];
 	argv++;
 	argc--;
 
+	image = fopen(path, "r");
+	if (!image) {
+		fprintf(stderr, "error: invalid image path '%s' specified: %s\n", path,
+			strerror(errno));
+		exit(1);
+	}
+
+	int head_read = fread(&header, 1, sizeof(header), image);
+	if (head_read != sizeof(header)) {
+		fprintf(stderr, "error: could not read full header: %d\n", head_read);
+		fclose(image);
+		exit(1);
+	}
+
+	if (strcmp(header.magic, MARFS_MAGIC) != 0) {
+		fprintf(stderr, "error: invalid header magic: %s\n", header.magic);
+		fclose(image);
+		exit(1);
+	}
+
+	if (header.version != MARFS_SPEC_VERSION) {
+		fprintf(stderr, "error: non-supported spec-version %d\n", header.version);
+		fclose(image);
+		exit(1);
+	}
+
 	fuse_main(argc, argv, &operations, NULL);
 
 	return 0;