From d3a300383c1973efb37dd4baf3668f0a6a75c9b2 Mon Sep 17 00:00:00 2001
From: Michal Hrusecky <Michal@Hrusecky.net>
Date: Mon, 13 Dec 2010 16:22:37 +0100
Subject: [PATCH] Wildcards substitutions in destinations of rules

Rules can be written using wildcards, but destinations had to be static.
This patch adds support for following strings in destination:

   %u - uid
   %U - username, uid in case of error
   %g - gid
   %G - group name, gid in case of error
   %p - pid
   %P - proccess name, pid in case of error

So more general rules can be specified using wildcards. Example rule can
be:

*@users        *     %G/%U

This will put all users in their own cgroups named by their login and 
group.

Signed-off-by: Michal Hrusecky <Michal@Hrusecky.net>
---
 src/api.c |   82 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 files changed, 81 insertions(+), 1 deletions(-)

diff --git a/src/api.c b/src/api.c
index 859190a..29b8627 100644
--- a/src/api.c
+++ b/src/api.c
@@ -2366,6 +2366,12 @@ int cgroup_change_cgroup_flags(uid_t uid, gid_t gid,
 	/* Temporary pointer to a rule */
 	struct cgroup_rule *tmp = NULL;
 
+	/* Temporary variables for destination substitution */
+	char newdest[FILENAME_MAX];
+	int i, j;
+	struct passwd * user_info;
+	struct group  * group_info;
+
 	/* Return codes */
 	int ret = 0;
 
@@ -2418,7 +2424,81 @@ int cgroup_change_cgroup_flags(uid_t uid, gid_t gid,
 	do {
 		cgroup_dbg("Executing rule %s for PID %d... ", tmp->username,
 								pid);
-		ret = cgroup_change_cgroup_path(tmp->destination,
+		// Destination substitutions
+		for(j = i = 0; i < strlen(tmp->destination); i++, j++) {
+			if(tmp->destination[i] == '%') {
+				switch(tmp->destination[++i]) {
+					case 'u':
+						j += snprintf(newdest+j,
+							FILENAME_MAX-j,
+							"%d", uid);
+						i++;
+						break;
+					case 'U':
+						user_info = getpwuid(uid);
+						if(user_info) {
+							j += snprintf(newdest+j,
+								FILENAME_MAX-j,
+								"%s",
+								user_info ->
+								pw_name);
+						} else {
+							j += snprintf(newdest+j,
+								FILENAME_MAX-j,
+								"%d", uid);
+						}
+						i++;
+						break;
+					case 'g':
+						j += snprintf(newdest+j,
+							FILENAME_MAX-j,
+							"%d", gid);
+						i++;
+						break;
+					case 'G':
+						group_info = getgrgid(gid);
+						if(group_info) {
+							j += snprintf(newdest+j,
+								FILENAME_MAX-j,
+								"%s",
+								group_info ->
+								gr_name);
+						} else {
+							j += snprintf(newdest+j,
+								FILENAME_MAX-j,
+								"%d", gid);
+						}
+						i++;
+						break;
+					case 'p':
+						j += snprintf(newdest+j,
+							FILENAME_MAX-j,
+							"%d", pid);
+						i++;
+						break;
+					case 'P':
+						if(procname) {
+							j += snprintf(newdest+j,
+								FILENAME_MAX-j,
+								"%s",
+								procname);
+						} else {
+							j += snprintf(newdest+j,
+								FILENAME_MAX-j,
+								"%d", pid);
+						}
+						i++;
+						break;
+					default:
+						newdest[j++] = '%';
+				}
+			}
+			if(tmp->destination[i] == '\\')
+				i++;
+			newdest[j] = tmp->destination[i];
+		}
+		newdest[j] = 0;
+		ret = cgroup_change_cgroup_path(newdest,
 				pid, (const char * const *)tmp->controllers);
 		if (ret) {
 			cgroup_dbg("FAILED! (Error Code: %d)\n", ret);
-- 
1.7.3.3