1 files changed, 133 insertions, 0 deletions
diff --git a/src/main/filters.c b/src/main/filters.c
new file mode 100644
index 0000000..f770fb7
--- /dev/null
+++ b/src/main/filters.c
@@ -0,0 +1,133 @@
+/*
+ * dpkg - main program for package management
+ * filters.c - filtering routines for excluding bits of packages
+ *
+ * Copyright © 2007, 2008 Tollef Fog Heen <tfheen@err.no>
+ * Copyright © 2008, 2010, 2012-2014 Guillem Jover <guillem@debian.org>
+ * Copyright © 2010 Canonical Ltd.
+ *   written by Martin Pitt <martin.pitt@canonical.com>
+ *
+ * This is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include <config.h>
+#include <compat.h>
+
+#include <fnmatch.h>
+
+#include <dpkg/i18n.h>
+#include <dpkg/dpkg.h>
+#include <dpkg/dpkg-db.h>
+#include <dpkg/db-fsys.h>
+
+#include "main.h"
+#include "filters.h"
+
+struct filter_node {
+	struct filter_node *next;
+	char *pattern;
+	bool include;
+};
+
+static struct filter_node *filter_head = NULL;
+static struct filter_node **filter_tail = &filter_head;
+
+void
+filter_add(const char *pattern, bool include)
+{
+	struct filter_node *filter;
+
+	debug(dbg_general, "adding %s filter for '%s'",
+	      include ? "include" : "exclude", pattern);
+
+	filter = m_malloc(sizeof(*filter));
+	filter->pattern = m_strdup(pattern);
+	filter->include = include;
+	filter->next = NULL;
+
+	*filter_tail = filter;
+	filter_tail = &filter->next;
+}
+
+bool
+filter_should_skip(struct tar_entry *ti)
+{
+	struct filter_node *f;
+	bool skip = false;
+
+	if (!filter_head)
+		return false;
+
+	/* Last match wins. */
+	for (f = filter_head; f != NULL; f = f->next) {
+		debug(dbg_eachfile, "filter comparing '%s' and '%s'",
+		      &ti->name[1], f->pattern);
+
+		if (fnmatch(f->pattern, &ti->name[1], 0) == 0) {
+			if (f->include) {
+				skip = false;
+				debug(dbg_eachfile, "filter including %s",
+				      ti->name);
+			} else {
+				skip = true;
+				debug(dbg_eachfile, "filter removing %s",
+				      ti->name);
+			}
+		}
+	}
+
+	/* We need to keep directories (or symlinks to directories) if a
+	 * glob excludes them, but a more specific include glob brings back
+	 * files; XXX the current implementation will probably include more
+	 * directories than necessary, but better err on the side of caution
+	 * than failing with “no such file or directory” (which would leave
+	 * the package in a very bad state). */
+	if (skip && (ti->type == TAR_FILETYPE_DIR ||
+	             ti->type == TAR_FILETYPE_SYMLINK)) {
+		debug(dbg_eachfile,
+		      "filter seeing if '%s' needs to be reincluded",
+		      &ti->name[1]);
+
+		for (f = filter_head; f != NULL; f = f->next) {
+			const char *wildcard;
+			int path_len;
+
+			if (!f->include)
+				continue;
+
+			/* Calculate the offset of the first wildcard
+			 * character in the pattern. */
+			wildcard = strpbrk(f->pattern, "*?[\\");
+			if (wildcard)
+				path_len = wildcard - f->pattern;
+			else
+				path_len = strlen(f->pattern);
+
+			/* Ignore any trailing slash for the comparison. */
+			while (path_len && f->pattern[path_len - 1] == '/')
+				path_len--;
+
+			debug(dbg_eachfiledetail,
+			      "filter subpattern '%.*s'", path_len, f->pattern);
+
+			if (strncmp(&ti->name[1], f->pattern, path_len) == 0) {
+				debug(dbg_eachfile, "filter reincluding %s",
+				      ti->name);
+				return false;
+			}
+		}
+	}
+
+	return skip;
+}