Hi,

There are some similar functions for getting process's data (uid,
gid) from /proc/<pid>/status file, so this patch integrates these
functions into one cgroup_get_procdata_from_status().
In addition, cgroup_get_procdata_from_status() can get also a
process name from /proc/<pid>/status file.


Thanks
Ken'ichi Ohmichi

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

5 files changed, 86 insertions, 132 deletions

diff --git a/include/libcgroup.h b/include/libcgroup.h
index 085c17a..4da55e4 100644
--- a/include/libcgroup.h
+++ b/include/libcgroup.h
@@ -285,6 +285,32 @@ int cgroup_get_task_begin(char *cgroup, char *controller, void **handle,
 								pid_t *pid);
 
 /**
+ * Get process data (euid, egid, and process name) from /proc/<pid>status
+ * file.
+ * @param pid: The process id
+ * @param euid: If this is NULL, the euid is not taken
+ * @param egid: If this is NULL, the egid is not taken
+ * @param procname: If this is NULL, the process name is not taken
+ * @param size_procname: The buffer size of procname
+ * @return 0 on success, > 0 on error.
+ */
+int cgroup_get_procdata_from_status(pid_t pid, uid_t *euid, gid_t *egid,
+					char *procname, size_t size_procname);
+
+/**
+ * Get process data (euid, egid, and process name) from /proc/<pid>status
+ * file.
+ * @param pid: The process id
+ * @param euid: If this is NULL, the euid is not taken
+ * @param egid: If this is NULL, the egid is not taken
+ * @param procname: If this is NULL, the process name is not taken
+ * @param size_procname: The buffer size of procname
+ * @return 0 on success, > 0 on error.
+ */
+int cgroup_get_procdata_from_status(pid_t pid, uid_t *euid, gid_t *egid,
+					char *procname, size_t size_procname);
+
+/**
  * Read the next task value
  * @handle: The handle used for iterating
  * @pid: The variable where the value will be stored
diff --git a/src/api.c b/src/api.c
index 9da3ebb..0739642 100644
--- a/src/api.c
+++ b/src/api.c
@@ -2477,3 +2477,58 @@ int cgroup_get_task_begin(char *cgroup, char *controller, void **handle,
 
 	return ret;
 }
+
+int cgroup_get_procdata_from_status(pid_t pid, uid_t *euid, gid_t *egid,
+					char *procname, size_t size_procname)
+{
+	FILE *f;
+	char path[FILENAME_MAX];
+	char buf[4092];
+	uid_t ruid, suid, fsuid;
+	gid_t rgid, sgid, fsgid;
+	bool find_euid = false;
+	bool find_egid = false;
+	bool find_procname = false;
+
+	if (euid)
+		find_euid = true;
+	if (egid)
+		find_egid = true;
+	if (procname)
+		find_procname = true;
+
+	sprintf(path, "/proc/%d/status", pid);
+	f = fopen(path, "r");
+	if (!f)
+		return 1;
+
+	memset(buf, '\0', sizeof(buf));
+	while (fgets(buf, sizeof(buf), f)) {
+		if (!strncmp(buf, "Uid:", 4) && find_euid) {
+			sscanf((buf + 5), "%d%d%d%d", &ruid, euid,
+				&suid, &fsuid);
+			cgroup_dbg("Scanned proc values are %d %d %d %d\n",
+				ruid, *euid, suid, fsuid);
+			find_euid = false;
+		} else if (!strncmp(buf, "Gid:", 4) && find_egid) {
+			sscanf((buf + 5), "%d%d%d%d", &rgid, egid,
+				&sgid, &fsgid);
+			cgroup_dbg("Scanned proc values are %d %d %d %d\n",
+				rgid, *egid, sgid, fsgid);
+			find_egid = false;
+		} else if (!strncmp(buf, "Name:", 5) && find_procname &&
+				(strlen(buf + 6) < size_procname)) {
+			sscanf((buf + 6), "%s", procname);
+			find_procname = false;
+		}
+		if (!find_euid && !find_egid && !find_procname) {
+			fclose(f);
+			return 0;
+		}
+		memset(buf, '\0', sizeof(buf));
+	}
+	/* failed to find some process data. */
+	fclose(f);
+	return 1;
+}
+
diff --git a/src/daemon/cgrulesengd.c b/src/daemon/cgrulesengd.c
index fb757c1..ea093ad 100644
--- a/src/daemon/cgrulesengd.c
+++ b/src/daemon/cgrulesengd.c
@@ -140,52 +140,6 @@ void flog(int level, const char *format, ...)
 	}
 }
 
-static int cgre_get_euid_egid_from_status(pid_t pid, uid_t *euid, gid_t *egid)
-{
-	/* Handle for the /proc/PID/status file */
-	FILE *f;
-
-	/* Path for /proc/PID/status file */
-	char path[FILENAME_MAX];
-
-	/* Temporary buffer */
-	char buf[4092];
-
-	/* UID data */
-	uid_t ruid, suid, fsuid;
-
-	/* GID data */
-	gid_t rgid, sgid, fsgid;
-
-	/*
-	 * First, we need to open the /proc/PID/status file so that we can
-	 * get the effective UID and GID for the process that we're working
-	 * on.  This process is probably not us, so we can't just call
-	 * geteuid() or getegid().
-	 */
-	sprintf(path, "/proc/%d/status", pid);
-	f = fopen(path, "r");
-	if (!f) {
-		flog(LOG_WARNING, "Failed to open %s", path);
-		return 1;
-	}
-
-	/* Have the eUID, need to find the eGID. */
-	memset(buf, '\0', sizeof(buf));
-	while (fgets(buf, sizeof(buf), f)) {
-		if (!strncmp(buf, "Uid:", 4)) {
-			sscanf((buf + 5), "%d%d%d%d", &ruid, euid,
-				&suid, &fsuid);
-		} else if (!strncmp(buf, "Gid:", 4)) {
-			sscanf((buf + 5), "%d%d%d%d", &rgid, egid,
-				&sgid, &fsgid);
-		}
-		memset(buf, '\0', sizeof(buf));
-	}
-	fclose(f);
-	return 0;
-}
-
 struct parent_info {
 	__u64 timestamp;
 	pid_t pid;
@@ -325,8 +279,8 @@ int cgre_process_event(const struct proc_event *ev, const int type)
 	default:
 		break;
 	}
-	if (cgre_get_euid_egid_from_status(pid, &euid, &egid))
-		/* cgre_get_euid_egid_from_status() returns 1 if it fails to
+	if (cgroup_get_procdata_from_status(pid, &euid, &egid, NULL, 0))
+		/* cgroup_get_procdata_from_status() returns 1 if it fails to
 		 * open /proc/<pid>/status file and that is not a problem. */
 		return 0;
 
diff --git a/src/libcgroup.map b/src/libcgroup.map
index 4b95daa..b8eff4e 100644
--- a/src/libcgroup.map
+++ b/src/libcgroup.map
@@ -62,4 +62,5 @@ global:
 	cgroup_read_stats_begin;
 	cgroup_read_stats_next;
 	cgroup_read_stats_end;
+	cgroup_get_procdata_from_status;
 } CGROUP_0.33;
diff --git a/src/tools/cgclassify.c b/src/tools/cgclassify.c
index de10510..f7d32ff 100644
--- a/src/tools/cgclassify.c
+++ b/src/tools/cgclassify.c
@@ -31,80 +31,6 @@
 #define TEMP_BUF	81
 
 /*
- * Go through /proc/<pid>/status file to determine the euid of the
- * process.
- * It returns 0 on success and negative values on failure.
- */
-
-int euid_of_pid(pid_t pid)
-{
-	FILE *fp;
-	char path[FILENAME_MAX];
-	char buf[TEMP_BUF];
-	uid_t ruid, euid, suid, fsuid;
-
-	sprintf(path, "/proc/%d/status", pid);
-	fp = fopen(path, "r");
-	if (!fp) {
-		cgroup_dbg("Error in opening file %s:%s\n", path,
-				strerror(errno));
-		return -1;
-	}
-
-	while (fgets(buf, TEMP_BUF, fp)) {
-		if (!strncmp(buf, "Uid:", 4)) {
-			sscanf((buf + 5), "%d%d%d%d", (int *)&ruid,
-				(int *)&euid, (int *)&suid, (int *)&fsuid);
-			cgroup_dbg("Scanned proc values are %d %d %d %d\n",
-				ruid, euid, suid, fsuid);
-			fclose(fp);
-			return euid;
-		}
-	}
-	fclose(fp);
-
-	/* If we are here, we could not find euid. Return error. */
-	return -1;
-}
-
-/*
- * Go through /proc/<pid>/status file to determine the egid of the
- * process.
- * It returns 0 on success and negative values on failure.
- */
-
-int egid_of_pid(pid_t pid)
-{
-	FILE *fp;
-	char path[FILENAME_MAX];
-	char buf[TEMP_BUF];
-	gid_t rgid, egid, sgid, fsgid;
-
-	sprintf(path, "/proc/%d/status", pid);
-	fp = fopen(path, "r");
-	if (!fp) {
-		cgroup_dbg("Error in opening file %s:%s\n", path,
-				strerror(errno));
-		return -1;
-	}
-
-	while (fgets(buf, TEMP_BUF, fp)) {
-		if (!strncmp(buf, "Gid:", 4)) {
-			sscanf((buf + 5), "%d%d%d%d", (int *)&rgid,
-				(int *)&egid, (int *)&sgid, (int *)&fsgid);
-			cgroup_dbg("Scanned proc values are %d %d %d %d\n",
-				rgid, egid, sgid, fsgid);
-			fclose(fp);
-			return egid;
-		}
-	}
-	fclose(fp);
-
-	/* If we are here, we could not find egid. Return error. */
-	return -1;
-}
-
-/*
  * Change process group as specified on command line.
  */
 int change_group_path(pid_t pid, struct cgroup_group_spec *cgroup_list[])
@@ -137,16 +63,8 @@ int change_group_uid_gid(pid_t pid)
 	int ret;
 
 	/* Put pid into right cgroup as per rules in /etc/cgrules.conf */
-	euid = euid_of_pid(pid);
-	if (euid == -1) {
-		fprintf(stderr, "Error in determining euid of"
-		" pid %d\n", pid);
-		return -1;
-	}
-
-	egid = egid_of_pid(pid);
-	if (egid == -1) {
-		fprintf(stderr, "Error in determining egid of"
+	if (cgroup_get_procdata_from_status(pid, &euid, &egid, NULL, 0)) {
+		fprintf(stderr, "Error in determining euid/egid of"
 		" pid %d\n", pid);
 		return -1;
 	}