libmisc: implement active_sessions_count()

Implement `active_sessions_count()` in `utmp.c` and `logind.c`.

Signed-off-by: Iker Pedrosa <ipedrosa@redhat.com>

lib/prototypes.h

@@ -511,6 +511,18 @@ extern void record_failure(const char *failent_user,
                            const char *hostname);
 #endif /* ENABLE_LOGIND */
 
+/**
+ * @brief Number of active user sessions
+ *
+ * @param[in] name username
+ * @param[in] limit maximum number of active sessions
+ *
+ * @return number of active sessions.
+ *
+ */
+extern unsigned long active_sessions_count(const char *name,
+                                           unsigned long limit);
+
 /* valid.c */
 extern bool valid (const char *, const struct passwd *);
 

libmisc/logind.c

@@ -34,3 +34,18 @@ done:
     free (session);
     return ret;
 }
+
+unsigned long active_sessions_count(const char *name, unsigned long unused)
+{
+    struct passwd *pw;
+    unsigned long count = 0;
+
+    pw = prefix_getpwnam(name);
+    if (pw == NULL) {
+        return 0;
+    }
+
+    count = sd_uid_get_sessions(pw->pw_uid, 0, NULL);
+
+    return count;
+}

libmisc/utmp.c

@@ -395,3 +395,30 @@ void record_failure(const char *failent_user,
 		free (failent);
 	}
 }
+
+unsigned long active_sessions_count(const char *name, unsigned long limit)
+{
+	struct utmp *ut;
+	unsigned long count = 0;
+
+	setutent ();
+	while ((ut = getutent ()))
+	{
+		if (USER_PROCESS != ut->ut_type) {
+			continue;
+		}
+		if ('\0' == ut->ut_user[0]) {
+			continue;
+		}
+		if (strncmp (name, ut->ut_user, sizeof (ut->ut_user)) != 0) {
+			continue;
+		}
+		count++;
+		if (count > limit) {
+			break;
+		}
+	}
+	endutent ();
+
+	return count;
+}