ServiceRegistration/srp-gw.h

   1 /* srp-gw.c
   2  *
   3  * Copyright (c) 2019 Apple Computer, Inc. All rights reserved.
   4  *
   5  * Licensed under the Apache License, Version 2.0 (the "License");
   6  * you may not use this file except in compliance with the License.
   7  * You may obtain a copy of the License at
   8  *
   9  *     http://www.apache.org/licenses/LICENSE-2.0
  10  *
  11  * Unless required by applicable law or agreed to in writing, software
  12  * distributed under the License is distributed on an "AS IS" BASIS,
  13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14  * See the License for the specific language governing permissions and
  15  * limitations under the License.
  16  *
  17  * Structure definitions for the Service Registration Protocol gateway.
  18  */
  19
  20 typedef struct subnet subnet_t;
  21 struct subnet {
  22     subnet_t *NULLABLE next;
  23     uint8_t preflen;
  24     uint8_t family;
  25     char bytes[8];
  26 };
  27
  28 typedef struct udp_validator udp_validator_t;
  29 struct udp_validator {
  30     udp_validator_t *NULLABLE next;
  31     char *NONNULL ifname;
  32     int ifindex;
  33     subnet_t *NONNULL subnets;
  34 };
  35
  36 typedef struct delete delete_t;
  37 struct delete {
  38     delete_t *NULLABLE next;
  39     dns_name_t *NONNULL name;
  40     dns_name_t *NONNULL zone;
  41     bool consumed;
  42 };
  43
  44 typedef struct host_addr host_addr_t;
  45 struct host_addr {
  46     host_addr_t *NULLABLE next;
  47     dns_rr_t rr;
  48 };
  49 typedef struct dns_host_description dns_host_description_t;
  50 struct dns_host_description {
  51     dns_name_t *NONNULL name;
  52     host_addr_t *NULLABLE addrs;
  53     dns_rr_t *NULLABLE key;
  54     delete_t *NULLABLE delete;
  55     int num_instances;
  56 };
  57
  58 typedef struct service service_t;
  59 struct service {
  60     service_t *NULLABLE next;
  61     dns_rr_t *NONNULL rr; // The service name is rr->name.
  62     dns_name_t *NONNULL zone;
  63 };
  64
  65 typedef struct service_instance service_instance_t;
  66 struct service_instance {
  67     service_instance_t *NULLABLE next;
  68     dns_host_description_t *NULLABLE host;
  69     dns_name_t *NONNULL name;
  70     delete_t *NULLABLE delete;
  71     service_t *NONNULL service;
  72     int num_instances;
  73     dns_rr_t *NULLABLE srv, *NULLABLE txt;
  74 };
  75
  76 // The update_t structure is used to maintain the ongoing state of a particular DNS Update.
  77
  78 typedef enum update_state update_state_t;
  79 enum update_state {
  80     connect_to_server,              // Establish a connection with the auth server.
  81     create_nonexistent,             // Update service instance assuming it's not already there (case 1).
  82     refresh_existing,               // Update service instance assuming it's already there and the same (case 2).
  83     create_nonexistent_instance,    // Update service instance assuming it's not there
  84     refresh_existing_instance,      // Update host assuming it's there and the same
  85     create_nonexistent_host,        // Update a host that's not present (and also the services)
  86     refresh_existing_host,          // Update a host that's present (and also the services)
  87     delete_failed_instance,         // The update failed, so delete service instances that were successfully added.
  88 };
  89
  90 typedef enum update_event update_event_t;
  91 enum update_event {
  92     update_event_connected,
  93     update_event_disconnected,
  94     update_event_response_received
  95 };
  96
  97 typedef struct update update_t;
  98 struct update {
  99     comm_t *NONNULL server;                       // Connection to authoritative server
 100     comm_t *NONNULL client;                       // Connection to SRP client (which might just be a UDP socket).
 101     update_state_t state;
 102     dns_host_description_t *NONNULL host;
 103     service_instance_t *NONNULL instances;
 104     service_instance_t *NULLABLE instance;        // If we are updating instances one at a time.
 105     service_instance_t *NULLABLE added_instances; // Instances we have successfully added.
 106     service_t *NONNULL services;
 107     dns_name_t *NULLABLE zone_name;               // If NULL, we are processing an update for services.arpa.
 108     message_t *NONNULL message;
 109     dns_message_t *NONNULL parsed_message;
 110     dns_wire_t *NONNULL update;                   // The current update...
 111     size_t update_length;
 112     size_t update_max;
 113     uint8_t fail_rcode;                           // rcode to return after deleting added service instances.
 114 };
 115
 116 // Local Variables:
 117 // mode: C
 118 // tab-width: 4
 119 // c-file-style: "bsd"
 120 // c-basic-offset: 4
 121 // fill-column: 108
 122 // indent-tabs-mode: nil
 123 // End: