Do not set "present" flag in deser_locator

It is done by "do_locator" after it has decided that the locator is
well-formed and, crucially, not to be ignored.  Setting it when there
are only ignored locators (of the unicast/multicast, data/metadata
variety) causes further processing to rely on uninitialized memory.

Signed-off-by: Erik Boasson <eb@ilities.com>

src/core/ddsi/src/ddsi_plist.c

@@ -117,12 +117,18 @@ struct piddesc {
   dds_return_t (*deser_validate_xform) (void * __restrict dst, const struct dd * __restrict dd);
 };
 
+enum do_locator_result {
+  DOLOC_ACCEPTED,
+  DOLOC_IGNORED,
+  DOLOC_INVALID
+};
+
 static dds_return_t validate_history_qospolicy (const dds_history_qospolicy_t *q);
 static dds_return_t validate_resource_limits_qospolicy (const dds_resource_limits_qospolicy_t *q);
 static dds_return_t validate_history_and_resource_limits (const dds_history_qospolicy_t *qh, const dds_resource_limits_qospolicy_t *qr);
 static dds_return_t validate_external_duration (const ddsi_duration_t *d);
 static dds_return_t validate_durability_service_qospolicy_acceptzero (const dds_durability_service_qospolicy_t *q, bool acceptzero);
-static dds_return_t do_locator (nn_locators_t *ls, uint64_t *present, uint64_t wanted, uint64_t fl, const struct dd *dd, const struct ddsi_tran_factory *factory);
+static enum do_locator_result do_locator (nn_locators_t *ls, uint64_t present, uint64_t wanted, uint64_t fl, const struct dd *dd, const struct ddsi_tran_factory *factory);
 static dds_return_t final_validation_qos (const dds_qos_t *dest, nn_protocol_version_t protocol_version, nn_vendorid_t vendorid, bool *dursvc_accepted_allzero, bool strict);
 static int partitions_equal (const void *srca, const void *srcb, size_t off);
 static dds_return_t ddsi_xqos_valid_strictness (const struct ddsrt_log_cfg *logcfg, const dds_qos_t *xqos, bool strict);
@@ -368,7 +374,7 @@ static dds_return_t deser_locator (void * __restrict dst, size_t * __restrict ds
   struct dd tmpdd = *dd;
   tmpdd.buf += *srcoff;
   tmpdd.bufsz -= *srcoff;
-  if (do_locator (x, flagset->present, flagset->wanted, flag, &tmpdd, dd->factory) < 0)
+  if (do_locator (x, *flagset->present, flagset->wanted, flag, &tmpdd, dd->factory) < 0)
     return DDS_RETCODE_BAD_PARAMETER;
   *srcoff += 24;
   *dstoff += sizeof (*x);
@@ -2304,12 +2310,12 @@ static dds_return_t validate_durability_service_qospolicy_acceptzero (const dds_
   return 0;
 }
 
-static dds_return_t add_locator (nn_locators_t *ls, uint64_t *present, uint64_t wanted, uint64_t fl, const nn_locator_t *loc)
+static void add_locator (nn_locators_t *ls, uint64_t present, uint64_t wanted, uint64_t fl, const nn_locator_t *loc)
 {
   if (wanted & fl)
   {
     struct nn_locators_one *nloc;
-    if (!(*present & fl))
+    if (!(present & fl))
     {
       ls->n = 0;
       ls->first = NULL;
@@ -2327,31 +2333,29 @@ static dds_return_t add_locator (nn_locators_t *ls, uint64_t *present, uint64_t
     }
     ls->last = nloc;
     ls->n++;
-    *present |= fl;
   }
-  return 0;
 }
 
-static int locator_address_prefix_zero (const nn_locator_t *loc, size_t prefixlen)
+static bool locator_address_prefix_zero (const nn_locator_t *loc, size_t prefixlen)
 {
   assert (prefixlen <= sizeof (loc->address));
   for (size_t i = 0; i < prefixlen; i++)
     if (loc->address[i] != 0)
-      return 0;
+      return false;
-  return 1;
+  return true;
 }
 
-static int locator_address_zero (const nn_locator_t *loc)
+static bool locator_address_zero (const nn_locator_t *loc)
 {
   return locator_address_prefix_zero (loc, sizeof (loc->address));
 }
 
-static dds_return_t do_locator (nn_locators_t *ls, uint64_t *present, uint64_t wanted, uint64_t fl, const struct dd *dd, const struct ddsi_tran_factory *factory)
+static enum do_locator_result do_locator (nn_locators_t *ls, uint64_t present, uint64_t wanted, uint64_t fl, const struct dd *dd, const struct ddsi_tran_factory *factory)
 {
   nn_locator_t loc;
 
   if (dd->bufsz < 24)
-    return DDS_RETCODE_BAD_PARAMETER;
+    return DOLOC_INVALID;
 
   memcpy (&loc.kind, dd->buf, 4);
   memcpy (&loc.port, dd->buf + 4, 4);
@@ -2366,62 +2370,63 @@ static dds_return_t do_locator (nn_locators_t *ls, uint64_t *present, uint64_t w
     case NN_LOCATOR_KIND_UDPv4:
     case NN_LOCATOR_KIND_TCPv4:
       if (!ddsi_factory_supports (factory, loc.kind))
-        return 0;
+        return DOLOC_IGNORED;
       if (!ddsi_is_valid_port (factory, loc.port))
-        return DDS_RETCODE_BAD_PARAMETER;
+        return DOLOC_INVALID;
       if (!locator_address_prefix_zero (&loc, 12))
-        return DDS_RETCODE_BAD_PARAMETER;
+        return DOLOC_INVALID;
       break;
     case NN_LOCATOR_KIND_UDPv6:
     case NN_LOCATOR_KIND_TCPv6:
       if (!ddsi_factory_supports (factory, loc.kind))
-        return 0;
+        return DOLOC_IGNORED;
       if (!ddsi_is_valid_port (factory, loc.port))
-        return DDS_RETCODE_BAD_PARAMETER;
+        return DOLOC_INVALID;
       break;
     case NN_LOCATOR_KIND_UDPv4MCGEN:
       if (!vendor_is_eclipse (dd->vendorid))
-        return 0;
+        return DOLOC_IGNORED;
       else
       {
         const nn_udpv4mcgen_address_t *x = (const nn_udpv4mcgen_address_t *) loc.address;
         if (!ddsi_factory_supports (factory, NN_LOCATOR_KIND_UDPv4))
-          return 0;
+          return DOLOC_IGNORED;
         if (!ddsi_is_valid_port (factory, loc.port))
-          return DDS_RETCODE_BAD_PARAMETER;
+          return DOLOC_INVALID;
         if ((uint32_t) x->base + x->count >= 28 || x->count == 0 || x->idx >= x->count)
-          return DDS_RETCODE_BAD_PARAMETER;
+          return DOLOC_INVALID;
       }
       break;
     case NN_LOCATOR_KIND_INVALID:
       if (!locator_address_zero (&loc))
-        return DDS_RETCODE_BAD_PARAMETER;
+        return DOLOC_INVALID;
       if (loc.port != 0)
-        return DDS_RETCODE_BAD_PARAMETER;
+        return DOLOC_INVALID;
       /* silently drop correctly formatted "invalid" locators. */
-      return 0;
+      return DOLOC_IGNORED;
     case NN_LOCATOR_KIND_RESERVED:
       /* silently drop "reserved" locators. */
-      return 0;
+      return DOLOC_IGNORED;
     case NN_LOCATOR_KIND_RAWETH:
       if (!vendor_is_eclipse (dd->vendorid))
-        return 0;
+        return DOLOC_IGNORED;
       else
       {
         if (!ddsi_factory_supports (factory, NN_LOCATOR_KIND_RAWETH))
-          return 0;
+          return DOLOC_IGNORED;
         if (!ddsi_is_valid_port (factory, loc.port))
-          return DDS_RETCODE_BAD_PARAMETER;
+          return DOLOC_INVALID;
         if (!locator_address_prefix_zero (&loc, 10))
-          return DDS_RETCODE_BAD_PARAMETER;
+          return DOLOC_INVALID;
       }
       break;
     default:
-      return 0;
+      return DOLOC_IGNORED;
   }
 
   loc.tran = ddsi_factory_supports (factory, loc.kind) ? factory : NULL;
-  return add_locator (ls, present, wanted, fl, &loc);
+  add_locator (ls, present, wanted, fl, &loc);
+  return DOLOC_ACCEPTED;
 }
 
 static void locator_from_ipv4address_port (nn_locator_t *loc, const nn_ipv4address_t *a, const nn_port_t *p, ddsi_tran_factory_t factory)
@@ -2473,7 +2478,7 @@ static dds_return_t do_ipv4address (ddsi_plist_t *dest, nn_ipaddress_params_tmp_
       ls = &dest->metatraffic_multicast_locators;
       break;
     default:
-      abort ();
+      return DDS_RETCODE_BAD_PARAMETER;
   }
   memcpy (a, dd->buf, sizeof (*a));
   dest_tmp->present |= fl_tmp;
@@ -2488,16 +2493,13 @@ static dds_return_t do_ipv4address (ddsi_plist_t *dest, nn_ipaddress_params_tmp_
     /* If port already known, add corresponding locator and discard
        both address & port from the set of present plist: this
        allows adding another pair. */
-
     nn_locator_t loc;
     locator_from_ipv4address_port (&loc, a, p, factory);
+    add_locator (ls, dest->present, wanted, fldest, &loc);
     dest_tmp->present &= ~(fl_tmp | fl1_tmp);
-    return add_locator (ls, &dest->present, wanted, fldest, &loc);
+    dest->present |= fldest;
-  }
-  else
-  {
-    return 0;
   }
+  return 0;
 }
 
 static dds_return_t do_port (ddsi_plist_t *dest, nn_ipaddress_params_tmp_t *dest_tmp, uint64_t wanted, uint32_t fl_tmp, const struct dd *dd, ddsi_tran_factory_t factory)
@@ -2533,7 +2535,7 @@ static dds_return_t do_port (ddsi_plist_t *dest, nn_ipaddress_params_tmp_t *dest
       ls = &dest->metatraffic_multicast_locators;
       break;
     default:
-      abort ();
+      return DDS_RETCODE_BAD_PARAMETER;
   }
   memcpy (p, dd->buf, sizeof (*p));
   if (dd->bswap)
@@ -2548,13 +2550,11 @@ static dds_return_t do_port (ddsi_plist_t *dest, nn_ipaddress_params_tmp_t *dest
        allows adding another pair. */
     nn_locator_t loc;
     locator_from_ipv4address_port (&loc, a, p, factory);
+    add_locator (ls, dest->present, wanted, fldest, &loc);
     dest_tmp->present &= ~(fl_tmp | fl1_tmp);
-    return add_locator (ls, &dest->present, wanted, fldest, &loc);
+    dest->present |= fldest;
-  }
-  else
-  {
-    return 0;
   }
+  return 0;
 }
 
 static dds_return_t return_unrecognized_pid (ddsi_plist_t *plist, nn_parameterid_t pid)