Hi,

This patch adds the parser of process name in /etc/cgrules.conf.

A new rule based on process name is as the following, and the process
name is stored into the member "procname" in struct cgroup_rule.
  <user>:<process name>  <controllers>   <destination>


Thanks
Ken'ichi Ohmichi

Signed-off-by: Ken'ichi Ohmichi <oomichi@mxs.nes.nec.co.jp>

3 files changed, 46 insertions, 5 deletions

diff --git a/include/libcgroup.h b/include/libcgroup.h
index 4da55e4..30c33bb 100644
--- a/include/libcgroup.h
+++ b/include/libcgroup.h
@@ -48,9 +48,14 @@ __BEGIN_DECLS
  * would require us to use a scanner/parser that can parse beyond ASCII
  */
 
+/* Task command name length (from linux-2.6.29) */
+#define TASK_COMM_LEN		16
+
+/* Maximum length of a key(<user>:<process name>) in the daemon config file */
+#define CGROUP_RULE_MAXKEY	(LOGIN_NAME_MAX + TASK_COMM_LEN + 1)
 
 /* Maximum length of a line in the daemon config file */
-#define CGROUP_RULE_MAXLINE (FILENAME_MAX + LOGIN_NAME_MAX + \
+#define CGROUP_RULE_MAXLINE	(FILENAME_MAX + CGROUP_RULE_MAXKEY + \
 	CG_CONTROLLER_MAX + 3)
 
 /* Definitions for the uid and gid members of a cgroup_rules */
diff --git a/src/api.c b/src/api.c
index 0739642..3e063cb 100644
--- a/src/api.c
+++ b/src/api.c
@@ -206,7 +206,10 @@ static void cgroup_free_rule(struct cgroup_rule *r)
 		cgroup_dbg("Warning: Attempted to free NULL rule.\n");
 		return;
 	}
-
+	if (r->procname) {
+		free(r->procname);
+		r->procname = NULL;
+	}
 	/* We must free any used controller strings, too. */
 	for(i = 0; i < MAX_MNT_ELEMENTS; i++) {
 		if (r->controllers[i])
@@ -297,6 +300,9 @@ static int cgroup_parse_rules(bool cache, uid_t muid, gid_t mgid)
 	/* Iterator for the line we're working on */
 	char *itr = NULL;
 
+	/* Pointer to process name in a line of the configuration file */
+	char *procname = NULL;
+
 	/* Pointer to the list that we're using */
 	struct cgroup_rule_list *lst = NULL;
 
@@ -310,11 +316,14 @@ static int cgroup_parse_rules(bool cache, uid_t muid, gid_t mgid)
 	struct passwd *pwd = NULL;
 
 	/* Temporary storage for a configuration rule */
+	char key[CGROUP_RULE_MAXKEY] = { '\0' };
 	char user[LOGIN_NAME_MAX] = { '\0' };
 	char controllers[CG_CONTROLLER_MAX] = { '\0' };
 	char destination[FILENAME_MAX] = { '\0' };
 	uid_t uid = CGRULE_INVALID;
 	gid_t gid = CGRULE_INVALID;
+	int len_username;
+	int len_procname;
 
 	/* The current line number */
 	unsigned int linenum = 0;
@@ -381,16 +390,33 @@ static int cgroup_parse_rules(bool cache, uid_t muid, gid_t mgid)
 		 * there's an error in the configuration file.
 		 */
 		skipped = false;
+		memset(key, '\0', sizeof(key));
 		memset(user, '\0', sizeof(user));
 		memset(controllers, '\0', sizeof(controllers));
 		memset(destination, '\0', sizeof(destination));
-		i = sscanf(itr, "%s%s%s", user, controllers, destination);
+		i = sscanf(itr, "%s%s%s", key, controllers, destination);
 		if (i != 3) {
 			cgroup_dbg("Failed to parse configuration file on"
 					" line %d.\n", linenum);
 			goto parsefail;
 		}
 
+		if (strchr(key, ':')) {
+			/* <user>:<procname>	<subsystem>	<destination> */
+			procname = strchr(key, ':') + 1;
+			len_username = procname - key - 1;
+			len_procname = strlen(key) - len_username - 1;
+			if (len_procname < 0) {
+				cgroup_dbg("Failed to parse configuration file on"
+						" line %d.\n", linenum);
+				goto parsefail;
+			}
+		} else {
+			len_username = strlen(key);
+			len_procname = 0;
+		}
+		strncpy(user, key, len_username);
+
 		/*
 		 * Next, check the user/group.  If it's a % sign, then we
 		 * are continuing another rule and UID/GID should not be
@@ -479,7 +505,13 @@ static int cgroup_parse_rules(bool cache, uid_t muid, gid_t mgid)
 
 		newrule->uid = uid;
 		newrule->gid = gid;
-		strncpy(newrule->username, user, strlen(user));
+		strncpy(newrule->username, user, len_username);
+		if (len_procname) {
+			newrule->procname = calloc(1, len_procname + 1);
+			strncpy(newrule->procname, procname, len_procname);
+		} else {
+			newrule->procname = NULL;
+		}
 		strncpy(newrule->destination, destination, strlen(destination));
 		newrule->next = NULL;
 
@@ -2008,7 +2040,10 @@ void cgroup_print_rules_config(FILE *fp)
 
 	itr = rl.head;
 	while (itr) {
-		fprintf(fp, "Rule: %s\n", itr->username);
+		fprintf(fp, "Rule: %s", itr->username);
+		if (itr->procname)
+			fprintf(fp, ":%s", itr->procname);
+		fprintf(fp, "\n");
 
 		if (itr->uid == CGRULE_WILD)
 			fprintf(fp, "  UID: any\n");
diff --git a/src/libcgroup-internal.h b/src/libcgroup-internal.h
index 9e69f10..6f314b6 100644
--- a/src/libcgroup-internal.h
+++ b/src/libcgroup-internal.h
@@ -74,6 +74,7 @@ struct cgroup_rules_data {
 struct cgroup_rule {
 	uid_t uid;
 	gid_t gid;
+	char *procname;
 	char username[LOGIN_NAME_MAX];
 	char destination[FILENAME_MAX];
 	char *controllers[MAX_MNT_ELEMENTS];