Add probing from the server that the client is still there, also make

the client check that the server is probing.


git-svn-id: svn://svn.h5l.se/heimdal/trunk/heimdal@12419 ec53bebd-3082-4978-b11e-865c3cabbd6b

lib/kadm5/iprop.h

@@ -46,6 +46,8 @@
 #include <util.h>
 #endif
 
+#include <parse_time.h>
+
 #define IPROP_VERSION "iprop-0.0"
 
 #define KADM5_SLAVE_ACL HDB_DB_DIR "/slaves"
@@ -62,7 +64,9 @@ enum iprop_cmd { I_HAVE = 1,
 		 FOR_YOU = 2,
 		 TELL_YOU_EVERYTHING = 3,
 		 ONE_PRINC = 4,
-		 NOW_YOU_HAVE = 5
+		 NOW_YOU_HAVE = 5,
+		 ARE_YOU_THERE = 6,
+		 I_AM_HERE = 7
 };
 
 #endif /* __IPROP_H__ */

lib/kadm5/ipropd_master.c

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997 - 2002 Kungliga Tekniska H<>gskolan
+ * Copyright (c) 1997 - 2003 Kungliga Tekniska H<>gskolan
  * (Royal Institute of Technology, Stockholm, Sweden). 
  * All rights reserved. 
  *
@@ -39,6 +39,11 @@ RCSID("$Id$");
 static krb5_log_facility *log_facility;
 
 const char *slave_stats_file = KADM5_SLAVE_STATS;
+const char *slave_time_missing = "2 min";
+const char *slave_time_gone = "5 min";
+
+static int time_before_missing;
+static int time_before_gone;
 
 static int
 make_signal_socket (krb5_context context)
@@ -122,6 +127,22 @@ slave_seen(slave *s)
     s->seen = time(NULL);
 }
 
+static int
+slave_missing_p (slave *s)
+{
+    if (time(NULL) > s->seen + time_before_missing)
+	return 1;
+    return 0;
+}
+
+static int
+slave_gone_p (slave *s)
+{
+    if (time(NULL) > s->seen + time_before_gone)
+	return 1;
+    return 0;
+}
+
 static void
 slave_dead(slave *s)
 {
@@ -316,6 +337,35 @@ send_complete (krb5_context context, slave *s,
     return 0;
 }
 
+static int
+send_are_you_there (krb5_context context, slave *s)
+{
+    krb5_data data;
+    int ret;
+
+    if (s->flags & SLAVE_F_DEAD)
+	return 0;
+
+    ret = krb5_data_alloc (&data, 4);
+    if (ret) {
+	krb5_warn (context, ret, "are_you_there: krb5_data_alloc");
+	slave_dead(s);
+	return 1;
+    }
+    _krb5_put_int(data.data, ARE_YOU_THERE, 4);
+    
+    ret = krb5_write_priv_message(context, s->ac, &s->fd, &data);
+    krb5_data_free(&data);
+
+    if (ret) {
+	krb5_warn (context, ret, "are_you_there: krb5_write_priv_message");
+	slave_dead(s);
+	return 1;
+    }
+
+    return 0;
+}
+
 static int
 send_diffs (krb5_context context, slave *s, int log_fd,
 	    const char *database, u_int32_t current_version)
@@ -348,7 +398,12 @@ send_diffs (krb5_context context, slave *s, int log_fd,
 	if (left == 0)
 	    return send_complete (context, s, database, current_version);
     }
-    krb5_data_alloc (&data, right - left + 4);
+    ret = krb5_data_alloc (&data, right - left + 4);
+    if (ret) {
+	krb5_warn (context, ret, "send_diffs: krb5_data_alloc");
+	slave_dead(s);
+	return 1;
+    }
     krb5_storage_read (sp, (char *)data.data + 4, data.length - 4);
     krb5_storage_free(sp);
 
@@ -358,7 +413,7 @@ send_diffs (krb5_context context, slave *s, int log_fd,
     krb5_data_free(&data);
 
     if (ret) {
-	krb5_warn (context, ret, "krb5_write_priv_message");
+	krb5_warn (context, ret, "send_diffs: krb5_write_priv_message");
 	slave_dead(s);
 	return 1;
     }
@@ -383,13 +438,29 @@ process_msg (krb5_context context, slave *s, int log_fd,
     }
 
     sp = krb5_storage_from_mem (out.data, out.length);
-    krb5_ret_int32 (sp, &tmp);
+    if (sp == NULL) {
+	krb5_warnx (context, "process_msg: no memory");
+	krb5_data_free (&out);
+	return 1;
+    }
+    if (krb5_ret_int32 (sp, &tmp) != 0) {
+	krb5_warnx (context, "process_msg: client send too short command");
+	krb5_data_free (&out);
+	return 1;
+    }
     switch (tmp) {
     case I_HAVE :
-	krb5_ret_int32 (sp, &tmp);
+	ret = krb5_ret_int32 (sp, &tmp);
+	if (ret != 0) {
+	    krb5_warnx (context, "process_msg: client send too I_HAVE data");
+	    break;
+	}
 	s->version = tmp;
 	ret = send_diffs (context, s, log_fd, database, current_version);
 	break;
+    case I_AM_HERE :
+	break;
+    case ARE_YOU_THERE:
     case FOR_YOU :
     default :
 	krb5_warnx (context, "Ignoring command %d", tmp);
@@ -490,6 +561,8 @@ static struct getargs args[] = {
       "keytab to get authentication from", "kspec" },
     { "database", 'd', arg_string, &database, "database", "file"},
     { "slave-stats-file", 0, arg_string, &slave_stats_file, "file"},
+    { "time-missing", 0, arg_string, &slave_time_missing, "time"},
+    { "time-gone", 0, arg_string, &slave_time_gone, "time"},
     { "version", 0, arg_flag, &version_flag },
     { "help", 0, arg_flag, &help_flag }
 };
@@ -519,6 +592,13 @@ main(int argc, char **argv)
 	exit(0);
     }
 
+    time_before_gone = parse_time (slave_time_gone,  "s");
+    if (time_before_gone < 0)
+	krb5_errx (context, 1, "couldn't parse time: %s", slave_time_gone);
+    time_before_missing = parse_time (slave_time_missing,  "s");
+    if (time_before_missing < 0)
+	krb5_errx (context, 1, "couldn't parse time: %s", slave_time_missing);
+
     pidfile (NULL);
     krb5_openlog (context, "ipropd-master", &log_facility);
     krb5_set_warn_dest(context, log_facility);
@@ -593,13 +673,14 @@ main(int argc, char **argv)
 	    old_version = current_version;
 	    kadm5_log_get_version_fd (log_fd, &current_version);
 
-	    if (current_version > old_version)
+	    if (current_version > old_version) {
 		for (p = slaves; p != NULL; p = p->next) {
 		    if (p->flags & SLAVE_F_DEAD)
 			continue;
 		    send_diffs (context, p, log_fd, database, current_version);
 		}
 	    }
+	}
 
 	if (ret && FD_ISSET(signal_fd, &readset)) {
 	    struct sockaddr_un peer_addr;
@@ -624,7 +705,10 @@ main(int argc, char **argv)
 		--ret;
 		if(process_msg (context, p, log_fd, database, current_version))
 		    slave_dead(p);
-	    }
+	    } else if (slave_gone_p (p))
+		slave_dead (p);
+	    else if (slave_missing_p (p))
+		send_are_you_there (context, p);
 	}
 
 	if (ret && FD_ISSET(listen_fd, &readset)) {

lib/kadm5/ipropd_slave.c

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997 - 2002 Kungliga Tekniska H<>gskolan
+ * Copyright (c) 1997 - 2003 Kungliga Tekniska H<>gskolan
  * (Royal Institute of Technology, Stockholm, Sweden). 
  * All rights reserved. 
  *
@@ -36,6 +36,8 @@
 RCSID("$Id$");
 
 static krb5_log_facility *log_facility;
+static char *server_time_lost = "5 min";
+static int time_before_lost;
 
 static int
 connect_to_master (krb5_context context, const char *master)
@@ -191,7 +193,7 @@ receive_loop (krb5_context context,
 	ret = kadm5_log_replay (server_context,
 				op, vers, len, sp);
 	if (ret)
-	    krb5_warn (context, ret, "kadm5_log_replay");
+	    krb5_warn (context, ret, "kadm5_log_replay: %d", (int)vers);
 	else
 	    server_context->log_context.version = vers;
 	krb5_storage_seek (sp, 8, SEEK_CUR);
@@ -218,6 +220,26 @@ receive (krb5_context context,
 	krb5_err (context, 1, ret, "db->close");
 }
 
+static void
+send_im_here (krb5_context context, int fd,
+	      krb5_auth_context auth_context)
+{
+    krb5_data data;
+    int ret;
+
+    ret = krb5_data_alloc (&data, 4);
+    if (ret)
+	krb5_err (context, 1, ret, "send_im_here");
+
+    _krb5_put_int(data.data, I_AM_HERE, 4);
+
+    ret = krb5_write_priv_message(context, auth_context, &fd, &data);
+    krb5_data_free(&data);
+
+    if (ret)
+	krb5_err (context, 1, ret, "krb5_write_priv_message");
+}
+
 static void
 receive_everything (krb5_context context, int fd,
 		    kadm5_server_context *server_context,
@@ -321,6 +343,8 @@ static struct getargs args[] = {
     { "realm", 'r', arg_string, &realm },
     { "keytab", 'k', arg_string, &keytab_str,
       "keytab to get authentication from", "kspec" },
+    { "time-lost", 0, arg_string, &server_time_lost,
+      "time before server is considered lost", "time" },
     { "version", 0, arg_flag, &version_flag },
     { "help", 0, arg_flag, &help_flag }
 };
@@ -375,6 +399,10 @@ main(int argc, char **argv)
     if(ret)
 	krb5_err(context, 1, ret, "krb5_kt_register");
 
+    time_before_lost = parse_time (server_time_lost,  "s");
+    if (time_before_lost < 0)
+	krb5_errx (context, 1, "couldn't parse time: %s", server_time_lost);
+
     memset(&conf, 0, sizeof(conf));
     if(realm) {
 	conf.mask |= KADM5_CONFIG_REALM;
@@ -420,6 +448,29 @@ main(int argc, char **argv)
 	krb5_data out;
 	krb5_storage *sp;
 	int32_t tmp;
+	fd_set readset;
+	struct timeval to;
+
+	if (master_fd >= FD_SETSIZE)
+	    krb5_errx (context, 1, "fd too large");
+
+	FD_ZERO(&readset);
+	FD_SET(master_fd, &readset);
+
+	to.tv_sec = time_before_lost;
+	to.tv_usec = 0;
+
+	ret = select (master_fd + 1,
+		      &readset, NULL, NULL, &to);
+	if (ret < 0) {
+	    if (errno == EINTR)
+		continue;
+	    else
+		krb5_err (context, 1, errno, "select");
+	}
+	if (ret == 0)
+	    krb5_errx (context, 1, "server didn't send a message "
+		       "in %d seconds", time_before_lost);
 
 	ret = krb5_read_priv_message(context, auth_context, &master_fd, &out);
 
@@ -438,9 +489,13 @@ main(int argc, char **argv)
 	    receive_everything (context, master_fd, server_context,
 				auth_context);
 	    break;
+	case ARE_YOU_THERE :
+	    send_im_here (context, master_fd, auth_context);
+	    break;
 	case NOW_YOU_HAVE :
 	case I_HAVE :
 	case ONE_PRINC :
+	case I_AM_HERE :
 	default :
 	    krb5_warnx (context, "Ignoring command %d", tmp);
 	    break;