1 files changed, 142 insertions, 0 deletions
diff --git a/lib/exclude.c b/lib/exclude.c
new file mode 100644
index 0000000..47b467d
--- /dev/null
+++ b/lib/exclude.c
@@ -0,0 +1,142 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * erofs-utils/lib/exclude.c
+ *
+ * Created by Li Guifu <bluce.lee@aliyun.com>
+ */
+#include <string.h>
+#include <stdlib.h>
+#include "erofs/err.h"
+#include "erofs/list.h"
+#include "erofs/print.h"
+#include "erofs/exclude.h"
+
+#define EXCLUDE_RULE_EXACT_SIZE	offsetof(struct erofs_exclude_rule, reg)
+#define EXCLUDE_RULE_REGEX_SIZE	sizeof(struct erofs_exclude_rule)
+
+static LIST_HEAD(exclude_head);
+static LIST_HEAD(regex_exclude_head);
+
+static unsigned int rpathlen;		/* root directory prefix length */
+
+void erofs_exclude_set_root(const char *rootdir)
+{
+	rpathlen = strlen(rootdir);
+}
+
+static void dump_regerror(int errcode, const char *s, const regex_t *preg)
+{
+	char str[512];
+
+	regerror(errcode, preg, str, sizeof(str));
+	erofs_err("invalid regex %s (%s)\n", s, str);
+}
+
+static struct erofs_exclude_rule *erofs_insert_exclude(const char *s,
+						       bool is_regex)
+{
+	struct erofs_exclude_rule *r;
+	int ret;
+	struct list_head *h;
+
+	r = malloc(is_regex ? EXCLUDE_RULE_REGEX_SIZE :
+			      EXCLUDE_RULE_EXACT_SIZE);
+	if (!r)
+		return ERR_PTR(-ENOMEM);
+
+	r->pattern = strdup(s);
+	if (!r->pattern) {
+		ret = -ENOMEM;
+		goto err_rule;
+	}
+
+	if (is_regex) {
+		ret = regcomp(&r->reg, s, REG_EXTENDED|REG_NOSUB);
+		if (ret) {
+			dump_regerror(ret, s, &r->reg);
+			goto err_rule;
+		}
+		h = &regex_exclude_head;
+	} else {
+		h = &exclude_head;
+	}
+
+	list_add_tail(&r->list, h);
+	erofs_info("insert exclude %s: %s\n",
+		   is_regex ? "regex" : "path", s);
+	return r;
+
+err_rule:
+	if (r->pattern)
+		free(r->pattern);
+	free(r);
+	return ERR_PTR(ret);
+}
+
+void erofs_cleanup_exclude_rules(void)
+{
+	struct erofs_exclude_rule *r, *n;
+	struct list_head *h;
+
+	h = &exclude_head;
+	list_for_each_entry_safe(r, n, h, list) {
+		list_del(&r->list);
+		free(r->pattern);
+		free(r);
+	}
+
+	h = &regex_exclude_head;
+	list_for_each_entry_safe(r, n, h, list) {
+		list_del(&r->list);
+		free(r->pattern);
+		regfree(&r->reg);
+		free(r);
+	}
+}
+
+int erofs_parse_exclude_path(const char *args, bool is_regex)
+{
+	struct erofs_exclude_rule *r = erofs_insert_exclude(args, is_regex);
+
+	if (IS_ERR(r)) {
+		erofs_cleanup_exclude_rules();
+		return PTR_ERR(r);
+	}
+	return 0;
+}
+
+struct erofs_exclude_rule *erofs_is_exclude_path(const char *dir,
+						 const char *name)
+{
+	char buf[PATH_MAX];
+	const char *s;
+	struct erofs_exclude_rule *r;
+
+	if (!dir) {
+		/* no prefix */
+		s = name;
+	} else {
+		sprintf(buf, "%s/%s", dir, name);
+		s = buf;
+	}
+
+	s += rpathlen;
+	while (*s == '/')
+		s++;
+
+	list_for_each_entry(r, &exclude_head, list) {
+		if (!strcmp(r->pattern, s))
+			return r;
+	}
+
+	list_for_each_entry(r, &regex_exclude_head, list) {
+		int ret = regexec(&r->reg, s, (size_t)0, NULL, 0);
+
+		if (!ret)
+			return r;
+		if (ret != REG_NOMATCH)
+			dump_regerror(ret, s, &r->reg);
+	}
+	return NULL;
+}
+