From: Kamalesh Babulal <kamalesh.babulal@oracle.com>
Date: Tue, 21 Jan 2025 08:10:27 +0000 (+0530)
Subject: cgrules: add support for process/dest cgroups with spaces
X-Git-Tag: v3.2.0~15
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=914b919d007611912d714f7935111d9275494f8e;p=thirdparty%2Flibcgroup.git

cgrules: add support for process/dest cgroups with spaces

In a cgrules rule, allow the process names and the destination
cgroups with spaces and other allowed special characters.

Reported-by: @LinuxOnTheDesktop (github username)
Fixes: https://github.com/libcgroup/libcgroup/issues/462
Signed-off-by: Kamalesh Babulal <kamalesh.babulal@oracle.com>
Signed-off-by: Tom Hromatka <tom.hromatka@oracle.com>
TJH: slight logic changes and add gunit support
---

diff --git a/src/api.c b/src/api.c
index 6df516fa..7ff095e7 100644
--- a/src/api.c
+++ b/src/api.c
@@ -554,6 +554,71 @@ STATIC int cgroup_parse_rules_options(char *options, struct cgroup_rule * const
 
 	return ret;
 }
+
+STATIC int get_next_rule_field(char *rule, char *field, size_t field_len, bool expect_quotes)
+{
+	char *quote_start = NULL, *quote_end = NULL;
+	char *tmp, *_rule = rule;
+	int len = 0;
+
+	if (!rule || !field)
+		return ECGINVAL;
+
+	/* trim the leading whitespace */
+	while (*rule == ' ' || *rule == '\t')
+		rule++;
+
+	tmp = rule;
+
+	while (*rule != ' ' && *rule != '\t' && *rule != '\n' && *rule != '\0') {
+		if (*rule == '"') {
+			quote_start = rule;
+			rule++;
+			break;
+		}
+		rule++;
+	}
+
+	if (quote_start) {
+		if (!expect_quotes)
+			return ECGINVAL;
+
+		while (*rule != '"' && *rule != '\n' && *rule != '\0')
+			rule++;
+
+		/* there should be a ending quote */
+		if (*rule != '"')
+			return ECGINVAL;
+
+		quote_end = rule;
+	}
+
+	if (quote_end) {
+		/* copy until the ending quotes */
+		len = quote_end - quote_start - 1;
+		if (len >= field_len)
+			return ECGINVAL;
+
+		strncpy(field, quote_start + 1, len);
+		field[len] = '\0';
+	} else {
+		len = rule - tmp;
+		if (len >= field_len)
+			return ECGINVAL;
+
+		strncpy(field, tmp, len);
+		field[len] = '\0';
+	}
+
+	len = (rule - _rule);
+
+	/* count until the ending quotes */
+	if (quote_start)
+		len += 1;
+
+	return len;
+}
+
 /**
  * Parse the configuration file that maps UID/GIDs to cgroups.  If ever the
  * configuration file is modified, applications should call this function to
@@ -677,15 +742,33 @@ static int cgroup_parse_rules_file(char *filename, bool cache, uid_t muid, gid_t
 		 * there's an error in the configuration file.
 		 */
 		skipped = false;
-		i = sscanf(itr, "%s%s%s%s", key, controllers, destination, options);
-		if (i < 3) {
+
+		ret = get_next_rule_field(itr, key, CGRP_RULE_MAXKEY, true);
+		if (!ret) {
+			cgroup_err("failed to parse configuration file on line %d\n", linenum);
+			goto parsefail;
+		}
+
+		itr += ret;
+		ret = get_next_rule_field(itr, controllers, CG_CONTROLLER_MAX, false);
+		if (!ret) {
+			cgroup_err("failed to parse configuration file on line %d\n", linenum);
+			goto parsefail;
+		}
+
+		itr += ret;
+		ret = get_next_rule_field(itr, destination, FILENAME_MAX, true);
+		if (!ret) {
 			cgroup_err("failed to parse configuration file on line %d\n", linenum);
 			goto parsefail;
-		} else if (i == 3) {
+		}
+
+		itr += ret;
+		ret = get_next_rule_field(itr, options, CG_OPTIONS_MAX, false);
+		if (!ret)
 			has_options = false;
-		} else if (i == 4) {
+		else
 			has_options = true;
-		}
 
 		procname = strchr(key, ':');
 		if (procname) {
diff --git a/src/libcgroup-internal.h b/src/libcgroup-internal.h
index 48dbf1c0..bb5c2213 100644
--- a/src/libcgroup-internal.h
+++ b/src/libcgroup-internal.h
@@ -423,6 +423,7 @@ int cgroup_chown_chmod_tasks(const char * const cg_path, uid_t uid, gid_t gid, m
 int cgroupv2_subtree_control(const char *path, const char *ctrl_name, bool enable);
 int cgroupv2_get_subtree_control(const char *path,  const char *ctrl_name, bool * const enabled);
 int cgroupv2_controller_enabled(const char * const cg_name, const char * const ctrl_name);
+int get_next_rule_field(char *rule, char *field, size_t field_len, bool expect_quotes);
 
 #endif /* UNIT_TEST */