[Bug 3094] ntpd trying to listen for broadcasts on a completely ipv6 network

bk: 5cf29f67_eZkyqH1Lo6pFGMDBkmZTg

diff --git a/ChangeLog b/ChangeLog
index 9ff845c81028eeecbd72fd587d28555bc5f781e5..191d04fe64d64ab1f05aed4145d17bec883c071a 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+---
+* [Bug 3094] ntpd trying to listen for broadcasts on a completely ipv6 network
+  <perlinger@ntp.org>
+
 ---
 (4.2.8p13) 2019/03/07 Released by Harlan Stenn <stenn@ntp.org>
 

diff --git a/include/ntp_io.h b/include/ntp_io.h
index d34d60a80b985ef24688b64876c0fd6418a148ac..9d63c9da06b259deee415851d74ae4b5f0f7ae7b 100644 (file)
--- a/include/ntp_io.h
+++ b/include/ntp_io.h
@@ -84,7 +84,7 @@ typedef enum {
 
 extern int     qos;
 SOCKET         move_fd(SOCKET fd);
-isc_boolean_t  get_broadcastclient_flag(void);
+/*isc_boolean_t        get_broadcastclient_flag(void);*/
 extern void    sau_from_netaddr(sockaddr_u *, const isc_netaddr_t *);
 extern void    add_nic_rule(nic_rule_match match_type,
                             const char *if_name, int prefixlen,

diff --git a/ntpd/ntp_io.c b/ntpd/ntp_io.c
index b89b996e9310c56d2f8a66ab9ced05a9a4160ea1..a1c318169a2f5a63782c58433c87d20229a8087c 100644 (file)
--- a/ntpd/ntp_io.c
+++ b/ntpd/ntp_io.c
@@ -177,7 +177,7 @@ endpt *     any_interface;          /* wildcard ipv4 interface */
 endpt *        any6_interface;         /* wildcard ipv6 interface */
 endpt *        loopback_interface;     /* loopback ipv4 interface */
 
-isc_boolean_t broadcast_client_enabled;        /* is broadcast client enabled */
+static isc_boolean_t broadcast_client_enabled; /* is broadcast client enabled */
 u_int sys_ifnum;                       /* next .ifnum to assign */
 int ninterfaces;                       /* Total number of interfaces */
 
@@ -2011,10 +2011,7 @@ update_interfaces(
         */
        refresh_all_peerinterfaces();
 
-       if (broadcast_client_enabled)
-               io_setbclient();
-
-       if (sys_bclient)
+       if (broadcast_client_enabled || sys_bclient)
                io_setbclient();
 
 #ifdef MCAST
@@ -2343,11 +2340,12 @@ socket_broadcast_disable(
 /*
  * return the broadcast client flag value
  */
-isc_boolean_t
+/*isc_boolean_t
 get_broadcastclient_flag(void)
 {
        return (broadcast_client_enabled);
 }
+*/
 
 /*
  * Check to see if the address is a multicast address
@@ -2605,32 +2603,38 @@ void
 io_setbclient(void)
 {
 #ifdef OPEN_BCAST_SOCKET
-       struct interface *      interf;
-       unsigned int            nif;
+       endpt *         ep;
+       unsigned int    nif, ni4, ni6;
 
-       nif = 0;
+       nif = ni4 = ni6 = 0;
        set_reuseaddr(1);
 
-       for (interf = ep_list;
-            interf != NULL;
-            interf = interf->elink) {
-
-               if (interf->flags & (INT_WILDCARD | INT_LOOPBACK))
+       for (ep = ep_list; ep != NULL; ep = ep->elink) {
+               /* count IPv6 vs IPv4 interfaces. Needed later to decide
+                * if we should log an error or not.
+                */
+               switch (ep->family) {
+               case AF_INET : ++ni4; break;
+               case AF_INET6: ++ni6; break;
+               default      :        break;
+               }
+               
+               if (ep->flags & (INT_WILDCARD | INT_LOOPBACK))
                        continue;
 
                /* use only allowed addresses */
-               if (interf->ignore_packets)
+               if (ep->ignore_packets)
                        continue;
 
                /* Need a broadcast-capable interface */
-               if (!(interf->flags & INT_BROADCAST))
+               if (!(ep->flags & INT_BROADCAST))
                        continue;
 
                /* Only IPv4 addresses are valid for broadcast */
-               REQUIRE(IS_IPV4(&interf->bcast));
+               REQUIRE(IS_IPV4(&ep->bcast));
 
                /* Do we already have the broadcast address open? */
-               if (interf->flags & INT_BCASTOPEN) {
+               if (ep->flags & INT_BCASTOPEN) {
                        /*
                         * account for already open interfaces to avoid
                         * misleading warning below
@@ -2642,19 +2646,19 @@ io_setbclient(void)
                /*
                 * Try to open the broadcast address
                 */
-               interf->family = AF_INET;
-               interf->bfd = open_socket(&interf->bcast, 1, 0, interf);
+               ep->family = AF_INET;
+               ep->bfd = open_socket(&ep->bcast, 1, 0, ep);
 
                /*
                 * If we succeeded then we use it otherwise enable
                 * broadcast on the interface address
                 */
-               if (interf->bfd != INVALID_SOCKET) {
+               if (ep->bfd != INVALID_SOCKET) {
                        nif++;
-                       interf->flags |= INT_BCASTOPEN;
+                       ep->flags |= INT_BCASTOPEN;
                        msyslog(LOG_INFO,
                                "Listen for broadcasts to %s on interface #%d %s",
-                               stoa(&interf->bcast), interf->ifnum, interf->name);
+                               stoa(&ep->bcast), ep->ifnum, ep->name);
                } else switch (errno) {
                        /* Silently ignore EADDRINUSE as we probably
                         * opened the socket already for an address in
@@ -2668,8 +2672,8 @@ io_setbclient(void)
                         * regular socket, it's quite useless to try this
                         * again.
                         */
-                       if (interf->fd != INVALID_SOCKET) {
-                               interf->flags |= INT_BCASTOPEN;
+                       if (ep->fd != INVALID_SOCKET) {
+                               ep->flags |= INT_BCASTOPEN;
                                nif++;
                        }
 #                  endif
@@ -2678,7 +2682,7 @@ io_setbclient(void)
                default:
                        msyslog(LOG_INFO,
                                "failed to listen for broadcasts to %s on interface #%d %s",
-                               stoa(&interf->bcast), interf->ifnum, interf->name);
+                               stoa(&ep->bcast), ep->ifnum, ep->name);
                        break;
                }
        }
@@ -2688,8 +2692,14 @@ io_setbclient(void)
                DPRINTF(1, ("io_setbclient: listening to %d broadcast addresses\n", nif));
        } else {
                broadcast_client_enabled = ISC_FALSE;
-               msyslog(LOG_ERR,
-                       "Unable to listen for broadcasts, no broadcast interfaces available");
+               /* This is expected when having only IPv6 interfaces
+                * and no IPv4 interfaces at all. We suppress the error
+                * log in that case... everything else should work!
+                */
+               if (ni4 && !ni6) {
+                       msyslog(LOG_ERR,
+                               "Unable to listen for broadcasts, no broadcast interfaces available");
+               }
        }
 #else
        msyslog(LOG_ERR,