From 73b4ec8392541a27815bccbaeccbdf1cdd5e19dd Mon Sep 17 00:00:00 2001
From: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
Date: Mon, 5 Aug 2019 15:00:08 +0200
Subject: Add a helper utility to compare filesystem trees

The intended use case is to compare two mounted or unpacke squashfs
images, so a repacked test image can be compared against its original
or an image unpacked with unsquashfs can be compared with an image
unpacked by rdsquashfs or sqfs2tar.

Since the tool is only intended to aid development (specifically
automated testing), it is not installed by `make install`.

Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
---
 difftool/node_compare.c | 99 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 99 insertions(+)
 create mode 100644 difftool/node_compare.c

(limited to 'difftool/node_compare.c')

diff --git a/difftool/node_compare.c b/difftool/node_compare.c
new file mode 100644
index 0000000..fae35ab
--- /dev/null
+++ b/difftool/node_compare.c
@@ -0,0 +1,99 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+/*
+ * node_compare.c
+ *
+ * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ */
+#include "difftool.h"
+
+int node_compare(tree_node_t *a, tree_node_t *b)
+{
+	char *path = node_path(a);
+	tree_node_t *ait, *bit;
+	int ret, status = 0;
+
+	if (path == NULL)
+		return -1;
+
+	if ((a->mode & S_IFMT) != (b->mode & S_IFMT)) {
+		fprintf(stdout, "%s has a different type\n", path);
+		free(path);
+		return 1;
+	}
+
+	if (!(compare_flags & COMPARE_NO_PERM)) {
+		if ((a->mode & ~S_IFMT) != (b->mode & ~S_IFMT)) {
+			fprintf(stdout, "%s has different permissions\n",
+				path);
+			status = 1;
+		}
+	}
+
+	if (!(compare_flags & COMPARE_NO_OWNER)) {
+		if (a->uid != b->uid || a->gid != b->gid) {
+			fprintf(stdout, "%s has different ownership\n", path);
+			status = 1;
+		}
+	}
+
+	switch (a->mode & S_IFMT) {
+	case S_IFSOCK:
+	case S_IFIFO:
+		break;
+	case S_IFBLK:
+	case S_IFCHR:
+		if (a->data.devno != b->data.devno) {
+			fprintf(stdout, "%s has different device number\n",
+				path);
+			status = 1;
+		}
+		break;
+	case S_IFLNK:
+		if (strcmp(a->data.slink_target, b->data.slink_target) != 0) {
+			fprintf(stdout, "%s has a different link target\n",
+				path);
+		}
+		break;
+	case S_IFDIR:
+		ret = compare_dir_entries(a, b);
+		if (ret < 0) {
+			status = -1;
+			break;
+		}
+		if (ret > 0)
+			status = 1;
+
+		free(path);
+		path = NULL;
+
+		ait = a->data.dir->children;
+		bit = b->data.dir->children;
+
+		while (ait != NULL && bit != NULL) {
+			ret = node_compare(ait, bit);
+			if (ret < 0)
+				return -1;
+			if (ret > 0)
+				status = 1;
+
+			ait = ait->next;
+			bit = bit->next;
+		}
+		break;
+	case S_IFREG:
+		ret = compare_files(a->data.file, b->data.file, path);
+		if (ret < 0) {
+			status = -1;
+		} else if (ret > 0) {
+			fprintf(stdout, "regular file %s differs\n", path);
+			status = 1;
+		}
+		break;
+	default:
+		fprintf(stdout, "%s has unknown type, ignoring\n", path);
+		break;
+	}
+
+	free(path);
+	return status;
+}
-- 
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