gensquashfs: add option to simply pack an input directory

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

1 files changed, 189 insertions, 0 deletions

diff --git a/lib/fstree/fstree_from_dir.c b/lib/fstree/fstree_from_dir.c
new file mode 100644
index 0000000..fb906f1
--- /dev/null
+++ b/lib/fstree/fstree_from_dir.c
@@ -0,0 +1,189 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+#include "fstree.h"
+#include "util.h"
+
+#include <sys/types.h>
+#include <dirent.h>
+#include <unistd.h>
+#include <string.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <errno.h>
+#include <fcntl.h>
+
+static size_t path_size(tree_node_t *n)
+{
+	size_t size = 0;
+
+	while (n != NULL) {
+		size += strlen(n->name) + 1;
+		n = n->parent;
+	}
+
+	return size;
+}
+
+static char *print_path(char *ptr, tree_node_t *n)
+{
+	if (n->parent != NULL) {
+		ptr = print_path(ptr, n->parent);
+		*(ptr++) = '/';
+		strcpy(ptr, n->name);
+		return ptr + strlen(ptr);
+	}
+
+	return ptr;
+}
+
+static int populate_dir(tree_node_t *root, int fd, size_t blocksize,
+			const char *rootdir)
+{
+	size_t size, blockcount;
+	struct dirent *ent;
+	struct stat sb;
+	tree_node_t *n;
+	ssize_t ret;
+	void *ptr;
+	DIR *dir;
+	int cfd;
+
+	dir = fdopendir(fd);
+	if (dir == NULL) {
+		perror("fdopendir");
+		close(fd);
+		return -1;
+	}
+
+	for (;;) {
+		n = NULL;
+		errno = 0;
+		ent = readdir(dir);
+
+		if (ent == NULL) {
+			if (errno) {
+				perror("readdir");
+				goto fail;
+			}
+			break;
+		}
+
+		if (!strcmp(ent->d_name, "..") || !strcmp(ent->d_name, "."))
+			continue;
+
+		if (fstatat(fd, ent->d_name, &sb, AT_SYMLINK_NOFOLLOW)) {
+			perror(ent->d_name);
+			goto fail;
+		}
+
+		size = sizeof(tree_node_t) + strlen(ent->d_name) + 1;
+
+		switch (sb.st_mode & S_IFMT) {
+		case S_IFLNK:
+			size += sb.st_size + 1;
+			break;
+		case S_IFREG:
+			blockcount = sb.st_size / blocksize + 1;
+
+			size += sizeof(file_info_t);
+			size += sizeof(uint32_t) * blockcount;
+
+			size += path_size(root) + strlen(ent->d_name) + 1;
+			size += strlen(rootdir) + 2;
+			break;
+		case S_IFDIR:
+			size += sizeof(dir_info_t);
+			break;
+		}
+
+		n = calloc(1, size);
+		if (n == NULL) {
+			perror("allocating tree node");
+			goto fail;
+		}
+
+		n->uid = sb.st_uid;
+		n->gid = sb.st_gid;
+		n->mode = sb.st_mode;
+		n->parent = root;
+
+		ptr = n->payload;
+
+		switch (sb.st_mode & S_IFMT) {
+		case S_IFLNK:
+			ret = readlinkat(fd, ent->d_name, ptr, sb.st_size);
+			if (ret < 0) {
+				perror("readlink");
+				goto fail;
+			}
+
+			n->data.slink_target = ptr;
+			ptr = (char *)ptr + strlen(ptr) + 1;
+			break;
+		case S_IFBLK:
+		case S_IFCHR:
+			n->data.devno = sb.st_rdev;
+			break;
+		case S_IFDIR:
+			n->data.dir = ptr;
+			ptr = (char *)ptr + sizeof(dir_info_t);
+			break;
+		case S_IFREG:
+			n->data.file = ptr;
+			ptr = (char *)ptr + sizeof(file_info_t);
+			ptr = (char *)ptr + sizeof(uint32_t) * blockcount;
+
+			n->data.file->input_file = ptr;
+			n->data.file->size = sb.st_size;
+
+			strcpy(ptr, rootdir);
+			ptr = (char *)ptr + strlen(ptr);
+			ptr = print_path(ptr, root);
+
+			*((char*)ptr) = '/';
+			strcpy((char *)ptr + 1, ent->d_name);
+			ptr = (char *)ptr + strlen(ptr) + 1;
+			break;
+		}
+
+		n->name = ptr;
+		strcpy(ptr, ent->d_name);
+
+		n->next = root->data.dir->children;
+		root->data.dir->children = n;
+	}
+
+	for (n = root->data.dir->children; n != NULL; n = n->next) {
+		if (S_ISDIR(n->mode)) {
+			cfd = openat(fd, n->name, O_RDONLY | O_DIRECTORY);
+			if (cfd < 0) {
+				perror(n->name);
+				goto fail_dir;
+			}
+
+			if (populate_dir(n, cfd, blocksize, rootdir)) {
+				close(cfd);
+				goto fail_dir;
+			}
+		}
+	}
+
+	closedir(dir);
+	return 0;
+fail:
+	free(n);
+fail_dir:
+	closedir(dir);
+	return -1;
+}
+
+int fstree_from_dir(fstree_t *fs, const char *path)
+{
+	int fd = open(path, O_RDONLY | O_DIRECTORY);
+
+	if (fd < 0) {
+		perror(path);
+		return -1;
+	}
+
+	return populate_dir(fs->root, fd, fs->block_size, path);
+}