src/libsystemd-network/radv-internal.h

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2 #pragma once
   3
   4 /***
   5   Copyright © 2017 Intel Corporation. All rights reserved.
   6 ***/
   7
   8 #include <netinet/icmp6.h>
   9
  10 #include "sd-radv.h"
  11
  12 #include "list.h"
  13 #include "ndisc-option.h"
  14 #include "network-common.h"
  15 #include "sparse-endian.h"
  16 #include "time-util.h"
  17
  18 /* RFC 4861 section 6.2.1.
  19  * MaxRtrAdvInterval
  20  * The maximum time allowed between sending unsolicited multicast Router Advertisements from the
  21  * interface, in seconds. MUST be no less than 4 seconds and no greater than 1800 seconds.
  22  * Default: 600 seconds */
  23 #define RADV_MIN_MAX_TIMEOUT_USEC                 (4 * USEC_PER_SEC)
  24 #define RADV_MAX_MAX_TIMEOUT_USEC                 (1800 * USEC_PER_SEC)
  25 #define RADV_DEFAULT_MAX_TIMEOUT_USEC             (600 * USEC_PER_SEC)
  26 /* RFC 4861 section 6.2.1.
  27  * MinRtrAdvInterval
  28  * The minimum time allowed between sending unsolicited multicast Router Advertisements from the
  29  * interface, in seconds. MUST be no less than 3 seconds and no greater than .75 * MaxRtrAdvInterval.
  30  * Default: 0.33 * MaxRtrAdvInterval If MaxRtrAdvInterval >= 9 seconds; otherwise, the Default is
  31  * MaxRtrAdvInterval (Note, this should be a typo. We use 0.75 * MaxRtrAdvInterval). */
  32 #define RADV_MIN_MIN_TIMEOUT_USEC                 (3 * USEC_PER_SEC)
  33 /* RFC 4861 section 6.2.4.
  34  * AdvDefaultLifetime
  35  * The value to be placed in the Router Lifetime field of Router Advertisements sent from the interface,
  36  * in seconds. MUST be either zero or between MaxRtrAdvInterval and 9000 seconds. A value of zero
  37  * indicates that the router is not to be used as a default router. These limits may be overridden by
  38  * specific documents that describe how IPv6 operates over different link layers. For instance, in a
  39  * point-to-point link the peers may have enough information about the number and status of devices at
  40  * the other end so that advertisements are needed less frequently.
  41  * Default: 3 * MaxRtrAdvInterval */
  42 #define RADV_MIN_ROUTER_LIFETIME_USEC             RADV_MIN_MAX_TIMEOUT_USEC
  43 #define RADV_MAX_ROUTER_LIFETIME_USEC             (9000 * USEC_PER_SEC)
  44 #define RADV_DEFAULT_ROUTER_LIFETIME_USEC         (3 * RADV_DEFAULT_MAX_TIMEOUT_USEC)
  45 /* RFC 4861 section 4.2.
  46  * Reachable Time and Retrans Timer
  47  * 32-bit unsigned integer. The time, in milliseconds. */
  48 #define RADV_MAX_UINT32_MSEC_USEC                 (UINT32_MAX * USEC_PER_MSEC)
  49 #define RADV_MAX_REACHABLE_TIME_USEC              RADV_MAX_UINT32_MSEC_USEC
  50 #define RADV_MAX_RETRANSMIT_USEC                  RADV_MAX_UINT32_MSEC_USEC
  51 /* draft-ietf-6man-slaac-renum-02 section 4.1.1.
  52  * AdvPreferredLifetime: max(AdvDefaultLifetime, 3 * MaxRtrAdvInterval)
  53  * AdvValidLifetime: 2 * AdvPreferredLifetime */
  54 #define RADV_DEFAULT_PREFERRED_LIFETIME_USEC      CONST_MAX(RADV_DEFAULT_ROUTER_LIFETIME_USEC, 3 * RADV_DEFAULT_MAX_TIMEOUT_USEC)
  55 #define RADV_DEFAULT_VALID_LIFETIME_USEC          (2 * RADV_DEFAULT_PREFERRED_LIFETIME_USEC)
  56 /* RFC 4861 section 10.
  57  * MAX_INITIAL_RTR_ADVERT_INTERVAL  16 seconds
  58  * MAX_INITIAL_RTR_ADVERTISEMENTS    3 transmissions
  59  * MAX_FINAL_RTR_ADVERTISEMENTS      3 transmissions
  60  * MIN_DELAY_BETWEEN_RAS             3 seconds
  61  * MAX_RA_DELAY_TIME                .5 seconds */
  62 #define RADV_MAX_INITIAL_RTR_ADVERT_INTERVAL_USEC (16 * USEC_PER_SEC)
  63 #define RADV_MAX_INITIAL_RTR_ADVERTISEMENTS       3
  64 #define RADV_MAX_FINAL_RTR_ADVERTISEMENTS         3
  65 #define RADV_MIN_DELAY_BETWEEN_RAS                3
  66 #define RADV_MAX_RA_DELAY_TIME_USEC               (500 * USEC_PER_MSEC)
  67 /* From RFC 8781 section 4.1
  68  * By default, the value of the Scaled Lifetime field SHOULD be set to the lesser of 3 x MaxRtrAdvInterval */
  69 #define RADV_PREF64_DEFAULT_LIFETIME_USEC         (3 * RADV_DEFAULT_MAX_TIMEOUT_USEC)
  70
  71 #define RADV_RDNSS_MAX_LIFETIME_USEC              (UINT32_MAX * USEC_PER_SEC)
  72 #define RADV_DNSSL_MAX_LIFETIME_USEC              (UINT32_MAX * USEC_PER_SEC)
  73 /* rfc6275 7.4 Neighbor Discovery Home Agent Lifetime.
  74  * The default value is the same as the Router Lifetime.
  75  * The maximum value corresponds to 18.2 hours. 0 MUST NOT be used. */
  76 #define RADV_HOME_AGENT_MAX_LIFETIME_USEC         (UINT16_MAX * USEC_PER_SEC)
  77
  78 #define RADV_OPT_ROUTE_INFORMATION                24
  79 #define RADV_OPT_RDNSS                            25
  80 #define RADV_OPT_DNSSL                            31
  81 /* Pref64 option type (RFC8781, section 4) */
  82 #define RADV_OPT_PREF64                           38
  83
  84 typedef enum RAdvState {
  85         RADV_STATE_IDLE                      = 0,
  86         RADV_STATE_ADVERTISING               = 1,
  87 } RAdvState;
  88
  89 struct sd_radv_opt_dns {
  90         uint8_t type;
  91         uint8_t length;
  92         uint16_t reserved;
  93         be32_t lifetime;
  94 } _packed_;
  95
  96 struct sd_radv {
  97         unsigned n_ref;
  98         RAdvState state;
  99
 100         int ifindex;
 101         char *ifname;
 102         struct in6_addr ipv6ll;
 103
 104         sd_event *event;
 105         int event_priority;
 106
 107         struct ether_addr mac_addr;
 108         uint8_t hop_limit;
 109         uint8_t flags;
 110         uint8_t preference;
 111         uint32_t mtu;
 112         usec_t reachable_usec;
 113         usec_t retransmit_usec;
 114         usec_t lifetime_usec; /* timespan */
 115
 116         int fd;
 117         unsigned ra_sent;
 118         sd_event_source *recv_event_source;
 119         sd_event_source *timeout_event_source;
 120
 121         unsigned n_prefixes;
 122         LIST_HEAD(sd_radv_prefix, prefixes);
 123
 124         unsigned n_route_prefixes;
 125         LIST_HEAD(sd_radv_route_prefix, route_prefixes);
 126
 127         unsigned n_pref64_prefixes;
 128         LIST_HEAD(sd_radv_pref64_prefix, pref64_prefixes);
 129
 130         size_t n_rdnss;
 131         struct sd_radv_opt_dns *rdnss;
 132         struct sd_radv_opt_dns *dnssl;
 133
 134         /* Mobile IPv6 extension: Home Agent Info.  */
 135         struct nd_opt_home_agent_info home_agent;
 136 };
 137
 138 #define radv_prefix_opt__contents {             \
 139         uint8_t type;                           \
 140         uint8_t length;                         \
 141         uint8_t prefixlen;                      \
 142         uint8_t flags;                          \
 143         be32_t lifetime_valid;                  \
 144         be32_t lifetime_preferred;              \
 145         uint32_t reserved;                      \
 146         struct in6_addr in6_addr;               \
 147 }
 148
 149 struct radv_prefix_opt radv_prefix_opt__contents;
 150
 151 /* We need the opt substructure to be packed, because we use it in send(). But
 152  * if we use _packed_, this means that the structure cannot be used directly in
 153  * normal code in general, because the fields might not be properly aligned.
 154  * But in this particular case, the structure is defined in a way that gives
 155  * proper alignment, even without the explicit _packed_ attribute. To appease
 156  * the compiler we use the "unpacked" structure, but we also verify that
 157  * structure contains no holes, so offsets are the same when _packed_ is used.
 158  */
 159 struct radv_prefix_opt__packed radv_prefix_opt__contents _packed_;
 160 assert_cc(sizeof(struct radv_prefix_opt) == sizeof(struct radv_prefix_opt__packed));
 161
 162 struct sd_radv_prefix {
 163         unsigned n_ref;
 164
 165         struct radv_prefix_opt opt;
 166
 167         LIST_FIELDS(struct sd_radv_prefix, prefix);
 168
 169         /* These are timespans, NOT points in time. */
 170         usec_t lifetime_valid_usec;
 171         usec_t lifetime_preferred_usec;
 172         /* These are points in time specified with clock_boottime_or_monotonic(), NOT timespans. */
 173         usec_t valid_until;
 174         usec_t preferred_until;
 175 };
 176
 177 #define radv_route_prefix_opt__contents {       \
 178         uint8_t type;                           \
 179         uint8_t length;                         \
 180         uint8_t prefixlen;                      \
 181         uint8_t flags_reserved;                 \
 182         be32_t  lifetime;                       \
 183         struct in6_addr in6_addr;               \
 184 }
 185
 186 struct radv_route_prefix_opt radv_route_prefix_opt__contents;
 187
 188 struct radv_route_prefix_opt__packed radv_route_prefix_opt__contents _packed_;
 189 assert_cc(sizeof(struct radv_route_prefix_opt) == sizeof(struct radv_route_prefix_opt__packed));
 190
 191 struct sd_radv_route_prefix {
 192         unsigned n_ref;
 193
 194         struct radv_route_prefix_opt opt;
 195
 196         LIST_FIELDS(struct sd_radv_route_prefix, prefix);
 197
 198         /* This is a timespan, NOT a point in time. */
 199         usec_t lifetime_usec;
 200         /* This is a point in time specified with clock_boottime_or_monotonic(), NOT a timespan. */
 201         usec_t valid_until;
 202 };
 203
 204 struct sd_radv_pref64_prefix {
 205         unsigned n_ref;
 206
 207         struct nd_opt_prefix64_info opt;
 208
 209         struct in6_addr in6_addr;
 210         uint8_t prefixlen;
 211
 212         usec_t lifetime_usec;
 213
 214         LIST_FIELDS(struct sd_radv_pref64_prefix, prefix);
 215 };
 216
 217 #define log_radv_errno(radv, error, fmt, ...)           \
 218         log_interface_prefix_full_errno(                \
 219                 "RADV: ",                               \
 220                 sd_radv, radv,                          \
 221                 error, fmt, ##__VA_ARGS__)
 222 #define log_radv(radv, fmt, ...)                        \
 223         log_interface_prefix_full_errno_zerook(         \
 224                 "RADV: ",                               \
 225                 sd_radv, radv,                          \
 226                 0, fmt, ##__VA_ARGS__)