ServiceRegistration/route.h

   1 /* route.h
   2  *
   3  * Copyright (c) 2019-2020 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
  18 #ifndef __SERVICE_REGISTRATION_ROUTE_H
  19 #define __SERVICE_REGISTRATION_ROUTE_H
  20 #if defined(USE_IPCONFIGURATION_SERVICE)
  21 #include <SystemConfiguration/SystemConfiguration.h>
  22 #include "IPConfigurationService.h"
  23 #endif
  24
  25 #define MIN_DELAY_BETWEEN_RAS 4000
  26 #define MSEC_PER_SEC (NSEC_PER_SEC / NSEC_PER_MSEC)
  27 #define MAX_ROUTER_RECEIVED_TIME_GAP_BEFORE_STALE 600 * MSEC_PER_SEC
  28
  29 // Fix this
  30 #ifndef IPV6_ROUTER_MODE_EXCLUSIVE
  31 #define IPV6_ROUTER_MODE_DISABLED       0
  32 #define IPV6_ROUTER_MODE_EXCLUSIVE      1
  33 #define IPV6_ROUTER_MODE_HYBRID         2
  34 #endif
  35
  36
  37 typedef struct interface interface_t;
  38 typedef struct icmp_message icmp_message_t;
  39 typedef struct network_link network_link_t;
  40 struct interface {
  41     int ref_count;
  42
  43     interface_t *NULLABLE next;
  44     char *NONNULL name;
  45
  46     // Wakeup event for next beacon.
  47     wakeup_t *NULLABLE beacon_wakeup;
  48
  49     // Wakeup event called after we're done sending solicits.  At this point we delete all routes more than 10 minutes
  50     // old; if none are left, then we assume there's no IPv6 service on the interface.
  51     wakeup_t *NULLABLE post_solicit_wakeup;
  52
  53     // Wakeup event to trigger the next router solicit to be sent.
  54     wakeup_t *NULLABLE router_solicit_wakeup;
  55
  56     // Wakeup event to deconfigure the on-link prefix after it is no longer valid.
  57     wakeup_t *NULLABLE deconfigure_wakeup;
  58
  59     // Wakeup event to detect that vicarious router discovery is complete
  60     wakeup_t *NULLABLE vicarious_discovery_complete;
  61
  62     // List of ICMP messages from different routers.
  63     icmp_message_t *NULLABLE routers;
  64
  65     // The link to which this interface is connected.
  66     network_link_t *NULLABLE link;
  67
  68 #if defined(USE_IPCONFIGURATION_SERVICE)
  69     // The service used to configure this interface with an address in the on-link prefix
  70     IPConfigurationServiceRef NULLABLE ip_configuration_service;
  71
  72     // SCDynamicStoreRef
  73     SCDynamicStoreRef NULLABLE ip_configuration_store;
  74 #endif
  75
  76     struct in6_addr link_local;  // Link-local address
  77     struct in6_addr ipv6_prefix; // This is the prefix we advertise, if advertise_ipv6_prefix is true.
  78
  79     // Absolute time of last beacon, and of next beacon.
  80     uint64_t last_beacon, next_beacon;
  81
  82     // Absolute deadline for deprecating the on-link prefix we've been announcing
  83     uint64_t deprecate_deadline;
  84
  85     // Preferred lifetime for the on-link prefix
  86     uint32_t preferred_lifetime;
  87
  88     // Valid lifetime for the on-link prefix
  89     uint32_t valid_lifetime;
  90
  91     // When the interface becomes active, we send up to three solicits.
  92     int num_solicits_sent;
  93
  94     // The interface index according to the operating systme.
  95     int index;
  96
  97     // Number of IPv4 addresses configured on link.
  98     int num_ipv4_addresses;
  99
 100     // Number of beacons sent. After the first three, the inter-beacon interval goes up.
 101     int num_beacons_sent;
 102
 103     // The interface link layer address, if known.
 104     uint8_t link_layer[6];
 105
 106     // True if the interface is not usable.
 107     bool inactive;
 108
 109     // True if this interface can never be used for routing to the thread network (e.g., loopback, tunnels, etc.)
 110     bool ineligible;
 111
 112     // True if we've determined that it's the thread interface.
 113     bool is_thread;
 114
 115     // True if we should advertise an on-link prefix.
 116     bool advertise_ipv6_prefix;
 117
 118     // True if we've gotten a link-layer address.
 119     bool have_link_layer_address;
 120
 121     // True if the on-link prefix is configured on the interface.
 122     bool on_link_prefix_configured;
 123
 124     // True if we've sent our first beacon since the interface came up.
 125     bool sent_first_beacon;
 126
 127     // Indicates whether or not router discovery has completed for this interface.
 128     bool router_discovery_complete;
 129
 130     // Indicates whether we're currently doing router discovery, so that we don't
 131     // restart it when we're already doing it.
 132     bool router_discovery_in_progress;
 133
 134     // Indicates that we've received a router discovery message from some other host,
 135     // and are waiting 20 seconds to snoop for replies to that RD message that are
 136     // multicast.   If we hear no replies during that time, we trigger router discovery.
 137     bool vicarious_router_discovery_in_progress;
 138
 139     // Indicates that we have received an interface removal event, it is useful when srp-mdns-proxy is changed to a new
 140     // network where the network signature are the same and they both have no IPv6 service (so no IPv6 prefix will be
 141     // removed), in such case there will be no change from srp-mdns-proxy's point of view. However, configd may still
 142     // flush the IPv6 routing since changing network would cause interface up/down. When the flushing happens,
 143     // srp-mdns-proxy should be able to reconfigure the IPv6 routing by reconfiguring IPv6 prefix. By setting
 144     // need_reconfigure_prefix only when interface address removal happens and check it during the routing evaluation
 145     // srp-mdns-proxy can reconfigure it after the routing evaluation finishes, like router discovery.
 146     bool need_reconfigure_prefix;
 147 };
 148
 149 typedef enum icmp_option_type {
 150     icmp_option_source_link_layer_address =  1,
 151     icmp_option_target_link_layer_address =  2,
 152     icmp_option_prefix_information        =  3,
 153     icmp_option_redirected_header         =  4,
 154     icmp_option_mtu                       =  5,
 155     icmp_option_route_information         = 24,
 156 } icmp_option_type_t;
 157
 158 typedef enum icmp_type {
 159     icmp_type_echo_request           = 128,
 160     icmp_type_echo_reply             = 129,
 161     icmp_type_router_solicitation    = 133,
 162     icmp_type_router_advertisement   = 134,
 163     icmp_type_neighbor_solicitation  = 135,
 164     icmp_type_neighbor_advertisement = 136,
 165     icmp_type_redirect               = 137,
 166 } icmp_type_t;
 167
 168 typedef struct link_layer_address {
 169     uint16_t length;
 170     uint8_t address[32];
 171 } link_layer_address_t;
 172
 173 typedef struct prefix_information {
 174     struct in6_addr prefix;
 175     uint8_t length;
 176     uint8_t flags;
 177     uint32_t valid_lifetime;
 178     uint32_t preferred_lifetime;
 179 } prefix_information_t;
 180
 181 typedef struct route_information {
 182     struct in6_addr prefix;
 183     uint8_t length;
 184     uint8_t flags;
 185     uint32_t route_lifetime;
 186 } route_information_t;
 187
 188 typedef struct icmp_option {
 189     icmp_option_type_t type;
 190     union {
 191         link_layer_address_t link_layer_address;
 192         prefix_information_t prefix_information;
 193         route_information_t route_information;
 194     } option;
 195 } icmp_option_t;
 196
 197 struct icmp_message {
 198     icmp_message_t *NULLABLE next;
 199     interface_t *NULLABLE interface;
 200     icmp_option_t *NULLABLE options;
 201     bool new_router;                // If this router information is a newly recevied one.
 202     bool received_time_already_adjusted;    // if the received time of the message is already adjusted by
 203                                                     // vicarious mode
 204     struct in6_addr source;
 205     struct in6_addr destination;
 206
 207     uint64_t received_time;
 208
 209     uint32_t reachable_time;
 210     uint32_t retransmission_timer;
 211     uint8_t cur_hop_limit;          // Current hop limit for Router Advertisement messages.
 212     uint8_t flags;
 213     uint8_t type;
 214     uint8_t code;
 215     uint16_t checksum;              // We hope the kernel figures this out for us.
 216     uint16_t router_lifetime;
 217
 218     int num_options;
 219     int hop_limit;                  // Hop limit provided by the kernel, must be 255.
 220 };
 221
 222 void ula_generate(void);
 223 bool start_route_listener(void);
 224 bool start_icmp_listener(void);
 225 void icmp_leave_join(int sock, int ifindex, bool join);
 226
 227 #define interface_create(name, iface) interface_create_(name, iface, __FILE__, __LINE__)
 228 interface_t *NULLABLE interface_create_(const char *NONNULL name, int ifindex,
 229                                                       const char *NONNULL file, int line);
 230 #define interface_retain(interface) interface_retain_(interface, __FILE__, __LINE__)
 231 void interface_retain_(interface_t *NONNULL interface, const char *NONNULL file, int line);
 232 #define interface_release(interface) interface_release_(interface, __FILE__, __LINE__)
 233 void interface_release_(interface_t *NONNULL interface, const char *NONNULL file, int line);
 234 bool interface_monitor_start(void);
 235 void thread_network_startup(void);
 236 void thread_network_shutdown(void);
 237 void partition_stop_advertising_pref_id(void);
 238 void partition_start_srp_listener(void);
 239 #endif // __SERVICE_REGISTRATION_ROUTE_H
 240
 241 // Local Variables:
 242 // mode: C
 243 // tab-width: 4
 244 // c-file-style: "bsd"
 245 // c-basic-offset: 4
 246 // fill-column: 120
 247 // indent-tabs-mode: nil
 248 // End: