Move directory iterator from libutil to libio

Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>

1 files changed, 204 insertions, 0 deletions

diff --git a/lib/io/src/unix/dir_iterator.c b/lib/io/src/unix/dir_iterator.c
new file mode 100644
index 0000000..d67fe83
--- /dev/null
+++ b/lib/io/src/unix/dir_iterator.c
@@ -0,0 +1,204 @@
+/* SPDX-License-Identifier: LGPL-3.0-or-later */
+/*
+ * dir_iterator.c
+ *
+ * Copyright (C) 2023 David Oberhollenzer <goliath@infraroot.at>
+ */
+#include "config.h"
+#include "io/dir_iterator.h"
+#include "util/util.h"
+#include "sqfs/error.h"
+
+#include <sys/stat.h>
+#include <stdlib.h>
+#include <dirent.h>
+#include <string.h>
+#include <errno.h>
+
+typedef struct {
+	dir_iterator_t base;
+
+	struct dirent *ent;
+	struct stat sb;
+	int state;
+	DIR *dir;
+} unix_dir_iterator_t;
+
+static void dir_destroy(sqfs_object_t *obj)
+{
+	unix_dir_iterator_t *it = (unix_dir_iterator_t *)obj;
+
+	closedir(it->dir);
+	free(it);
+}
+
+static int dir_read_link(dir_iterator_t *base, char **out)
+{
+	unix_dir_iterator_t *it = (unix_dir_iterator_t *)base;
+	ssize_t ret;
+	size_t size;
+	char *str;
+
+	*out = NULL;
+
+	if (it->state < 0)
+		return it->state;
+
+	if (it->state > 0 || it->ent == NULL)
+		return SQFS_ERROR_NO_ENTRY;
+
+	if ((sizeof(it->sb.st_size) > sizeof(size_t)) &&
+	    it->sb.st_size > SIZE_MAX) {
+		return SQFS_ERROR_ALLOC;
+	}
+
+	if (SZ_ADD_OV((size_t)it->sb.st_size, 1, &size))
+		return SQFS_ERROR_ALLOC;
+
+	str = calloc(1, size);
+	if (str == NULL)
+		return SQFS_ERROR_ALLOC;
+
+	ret = readlinkat(dirfd(it->dir), it->ent->d_name,
+			 str, (size_t)it->sb.st_size);
+	if (ret < 0) {
+		free(str);
+		return SQFS_ERROR_IO;
+	}
+
+	str[ret] = '\0';
+
+	*out = str;
+	return 0;
+}
+
+static int dir_next(dir_iterator_t *base, dir_entry_t **out)
+{
+	unix_dir_iterator_t *it = (unix_dir_iterator_t *)base;
+	dir_entry_t *decoded;
+	size_t len;
+
+	*out = NULL;
+	if (it->state != 0)
+		return it->state;
+
+	errno = 0;
+	it->ent = readdir(it->dir);
+
+	if (it->ent == NULL) {
+		if (errno != 0) {
+			it->state = SQFS_ERROR_IO;
+		} else {
+			it->state = 1;
+		}
+
+		return it->state;
+	}
+
+	if (fstatat(dirfd(it->dir), it->ent->d_name,
+		    &it->sb, AT_SYMLINK_NOFOLLOW)) {
+		it->state = SQFS_ERROR_IO;
+		return it->state;
+	}
+
+	len = strlen(it->ent->d_name);
+
+	decoded = alloc_flex(sizeof(*decoded), 1, len + 1);
+	if (decoded == NULL) {
+		it->state = SQFS_ERROR_ALLOC;
+		return it->state;
+	}
+
+	memcpy(decoded->name, it->ent->d_name, len);
+	decoded->mtime = it->sb.st_mtime;
+	decoded->dev = it->sb.st_dev;
+	decoded->rdev = it->sb.st_rdev;
+	decoded->uid = it->sb.st_uid;
+	decoded->gid = it->sb.st_gid;
+	decoded->mode = it->sb.st_mode;
+
+	*out = decoded;
+	return it->state;
+}
+
+static int dir_open_subdir(dir_iterator_t *base, dir_iterator_t **out)
+{
+	const unix_dir_iterator_t *it = (const unix_dir_iterator_t *)base;
+	unix_dir_iterator_t *sub = NULL;
+	int fd;
+
+	*out = NULL;
+
+	if (it->state < 0)
+		return it->state;
+
+	if (it->state > 0 || it->ent == NULL)
+		return SQFS_ERROR_NO_ENTRY;
+
+	fd = openat(dirfd(it->dir), it->ent->d_name, O_RDONLY | O_DIRECTORY);
+	if (fd < 0) {
+		if (errno == ENOTDIR)
+			return SQFS_ERROR_NOT_DIR;
+		return SQFS_ERROR_IO;
+	}
+
+	sub = calloc(1, sizeof(*sub));
+	if (sub == NULL)
+		goto fail_alloc;
+
+	sub->dir = fdopendir(fd);
+	if (sub->dir == NULL)
+		goto fail_alloc;
+
+	if (fstat(dirfd(sub->dir), &sub->sb)) {
+		free(sub);
+		return SQFS_ERROR_IO;
+	}
+
+	sqfs_object_init(sub, dir_destroy, NULL);
+	((dir_iterator_t *)sub)->dev = sub->sb.st_dev;
+	((dir_iterator_t *)sub)->next = dir_next;
+	((dir_iterator_t *)sub)->read_link = dir_read_link;
+	((dir_iterator_t *)sub)->open_subdir = dir_open_subdir;
+
+	*out = (dir_iterator_t *)sub;
+	return 0;
+fail_alloc:
+	free(sub);
+	close(fd);
+	return SQFS_ERROR_ALLOC;
+}
+
+dir_iterator_t *dir_iterator_create(const char *path)
+{
+	unix_dir_iterator_t *it = calloc(1, sizeof(*it));
+
+	if (it == NULL) {
+		perror(path);
+		return NULL;
+	}
+
+	it->state = 0;
+	it->dir = opendir(path);
+
+	if (it->dir == NULL) {
+		perror(path);
+		free(it);
+		return NULL;
+	}
+
+	if (fstat(dirfd(it->dir), &it->sb)) {
+		perror(path);
+		closedir(it->dir);
+		free(it);
+		return NULL;
+	}
+
+	sqfs_object_init(it, dir_destroy, NULL);
+	((dir_iterator_t *)it)->dev = it->sb.st_dev;
+	((dir_iterator_t *)it)->next = dir_next;
+	((dir_iterator_t *)it)->read_link = dir_read_link;
+	((dir_iterator_t *)it)->open_subdir = dir_open_subdir;
+
+	return (dir_iterator_t *)it;
+}