src/odhcp6c.h

   1 /**
   2  * Copyright (C) 2012-2014 Steven Barth <steven@midlink.org>
   3  * Copyright (C) 2018 Hans Dedecker <dedeckeh@gmail.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License v2 as published by
   7  * the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  */
  15 #pragma once
  16 #include <stdint.h>
  17 #include <stdbool.h>
  18 #include <netinet/in.h>
  19
  20 #define _unused __attribute__((unused))
  21 #define _packed __attribute__((packed))
  22 #define _aligned(n) __attribute__((aligned(n)))
  23
  24 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
  25
  26 #define ND_OPT_RECURSIVE_DNS 25
  27 #define ND_OPT_DNSSL 31
  28
  29 #define DHCPV6_SOL_MAX_RT 120
  30 #define DHCPV6_REQ_MAX_RT 30
  31 #define DHCPV6_CNF_MAX_RT 4
  32 #define DHCPV6_REN_MAX_RT 600
  33 #define DHCPV6_REB_MAX_RT 600
  34 #define DHCPV6_INF_MAX_RT 120
  35
  36 #define RA_MIN_ADV_INTERVAL 3   /* RFC 4861 paragraph 6.2.1 */
  37
  38 enum dhcvp6_opt {
  39         DHCPV6_OPT_CLIENTID = 1,
  40         DHCPV6_OPT_SERVERID = 2,
  41         DHCPV6_OPT_IA_NA = 3,
  42         DHCPV6_OPT_IA_TA = 4,
  43         DHCPV6_OPT_IA_ADDR = 5,
  44         DHCPV6_OPT_ORO = 6,
  45         DHCPV6_OPT_PREF = 7,
  46         DHCPV6_OPT_ELAPSED = 8,
  47         DHCPV6_OPT_RELAY_MSG = 9,
  48         DHCPV6_OPT_AUTH = 11,
  49         DHCPV6_OPT_UNICAST = 12,
  50         DHCPV6_OPT_STATUS = 13,
  51         DHCPV6_OPT_RAPID_COMMIT = 14,
  52         DHCPV6_OPT_USER_CLASS = 15,
  53         DHCPV6_OPT_VENDOR_CLASS = 16,
  54         DHCPV6_OPT_INTERFACE_ID = 18,
  55         DHCPV6_OPT_RECONF_MESSAGE = 19,
  56         DHCPV6_OPT_RECONF_ACCEPT = 20,
  57         DHCPV6_OPT_DNS_SERVERS = 23,
  58         DHCPV6_OPT_DNS_DOMAIN = 24,
  59         DHCPV6_OPT_IA_PD = 25,
  60         DHCPV6_OPT_IA_PREFIX = 26,
  61         DHCPV6_OPT_SNTP_SERVERS = 31,
  62         DHCPV6_OPT_INFO_REFRESH = 32,
  63         DHCPV6_OPT_FQDN = 39,
  64         DHCPV6_OPT_NTP_SERVER = 56,
  65         DHCPV6_OPT_SIP_SERVER_D = 21,
  66         DHCPV6_OPT_SIP_SERVER_A = 22,
  67         DHCPV6_OPT_AFTR_NAME = 64,
  68         DHCPV6_OPT_PD_EXCLUDE = 67,
  69         DHCPV6_OPT_SOL_MAX_RT = 82,
  70         DHCPV6_OPT_INF_MAX_RT = 83,
  71 #ifdef EXT_CER_ID
  72         /* draft-donley-dhc-cer-id-option-03 */
  73         DHCPV6_OPT_CER_ID = EXT_CER_ID,
  74 #endif
  75         /* draft-ietf-softwire-map-dhcp-08 */
  76         DHCPV6_OPT_S46_RULE = 89,
  77         DHCPV6_OPT_S46_BR = 90,
  78         DHCPV6_OPT_S46_DMR = 91,
  79         DHCPV6_OPT_S46_V4V6BIND = 92,
  80         DHCPV6_OPT_S46_PORTPARAMS = 93,
  81         DHCPV6_OPT_S46_CONT_MAPE = 94,
  82         DHCPV6_OPT_S46_CONT_MAPT = 95,
  83         DHCPV6_OPT_S46_CONT_LW = 96,
  84 };
  85
  86 enum dhcpv6_opt_npt {
  87         NTP_SRV_ADDR = 1,
  88         NTP_MC_ADDR = 2,
  89         NTP_SRV_FQDN = 3
  90 };
  91
  92 enum dhcpv6_msg {
  93         DHCPV6_MSG_UNKNOWN = 0,
  94         DHCPV6_MSG_SOLICIT = 1,
  95         DHCPV6_MSG_ADVERT = 2,
  96         DHCPV6_MSG_REQUEST = 3,
  97         DHCPV6_MSG_RENEW = 5,
  98         DHCPV6_MSG_REBIND = 6,
  99         DHCPV6_MSG_REPLY = 7,
 100         DHCPV6_MSG_RELEASE = 8,
 101         DHCPV6_MSG_DECLINE = 9,
 102         DHCPV6_MSG_RECONF = 10,
 103         DHCPV6_MSG_INFO_REQ = 11,
 104         _DHCPV6_MSG_MAX
 105 };
 106
 107 enum dhcpv6_status {
 108         DHCPV6_Success = 0,
 109         DHCPV6_UnspecFail = 1,
 110         DHCPV6_NoAddrsAvail = 2,
 111         DHCPV6_NoBinding = 3,
 112         DHCPV6_NotOnLink = 4,
 113         DHCPV6_UseMulticast = 5,
 114         DHCPV6_NoPrefixAvail = 6,
 115         _DHCPV6_Status_Max
 116 };
 117
 118 enum dhcpv6_config {
 119         DHCPV6_STRICT_OPTIONS = 1,
 120         DHCPV6_CLIENT_FQDN = 2,
 121         DHCPV6_ACCEPT_RECONFIGURE = 4,
 122 };
 123
 124 typedef int(reply_handler)(enum dhcpv6_msg orig, const int rc,
 125                 const void *opt, const void *end, const struct sockaddr_in6 *from);
 126
 127 // retransmission strategy
 128 struct dhcpv6_retx {
 129         bool delay;
 130         uint8_t init_timeo;
 131         uint16_t max_timeo;
 132         uint8_t max_rc;
 133         char name[8];
 134         reply_handler *handler_reply;
 135         int(*handler_finish)(void);
 136 };
 137
 138 // DHCPv6 Protocol Headers
 139 struct dhcpv6_header {
 140         uint8_t msg_type;
 141         uint8_t tr_id[3];
 142 } __attribute__((packed));
 143
 144 struct dhcpv6_ia_hdr {
 145         uint16_t type;
 146         uint16_t len;
 147         uint32_t iaid;
 148         uint32_t t1;
 149         uint32_t t2;
 150 } _packed;
 151
 152 struct dhcpv6_ia_addr {
 153         uint16_t type;
 154         uint16_t len;
 155         struct in6_addr addr;
 156         uint32_t preferred;
 157         uint32_t valid;
 158 } _packed;
 159
 160 struct dhcpv6_ia_prefix {
 161         uint16_t type;
 162         uint16_t len;
 163         uint32_t preferred;
 164         uint32_t valid;
 165         uint8_t prefix;
 166         struct in6_addr addr;
 167 } _packed;
 168
 169 struct dhcpv6_duid {
 170         uint16_t type;
 171         uint16_t len;
 172         uint16_t duid_type;
 173         uint8_t data[128];
 174 } _packed;
 175
 176 struct dhcpv6_auth_reconfigure {
 177         uint16_t type;
 178         uint16_t len;
 179         uint8_t protocol;
 180         uint8_t algorithm;
 181         uint8_t rdm;
 182         uint64_t replay;
 183         uint8_t reconf_type;
 184         uint8_t key[16];
 185 } _packed;
 186
 187 struct dhcpv6_cer_id {
 188         uint16_t type;
 189         uint16_t len;
 190         struct in6_addr addr;
 191 } _packed;
 192
 193 struct dhcpv6_s46_portparams {
 194         uint8_t offset;
 195         uint8_t psid_len;
 196         uint16_t psid;
 197 } _packed;
 198
 199 struct dhcpv6_s46_v4v6bind {
 200         struct in_addr ipv4_address;
 201         uint8_t bindprefix6_len;
 202         uint8_t bind_ipv6_prefix[];
 203 } _packed;
 204
 205 struct dhcpv6_s46_dmr {
 206         uint8_t dmr_prefix6_len;
 207         uint8_t dmr_ipv6_prefix[];
 208 } _packed;
 209
 210 struct dhcpv6_s46_rule {
 211         uint8_t flags;
 212         uint8_t ea_len;
 213         uint8_t prefix4_len;
 214         struct in_addr ipv4_prefix;
 215         uint8_t prefix6_len;
 216         uint8_t ipv6_prefix[];
 217 } _packed;
 218
 219 #define dhcpv6_for_each_option(start, end, otype, olen, odata)\
 220         for (uint8_t *_o = (uint8_t*)(start); _o + 4 <= (uint8_t*)(end) &&\
 221                 ((otype) = _o[0] << 8 | _o[1]) && ((odata) = (void*)&_o[4]) &&\
 222                 ((olen) = _o[2] << 8 | _o[3]) + (odata) <= (uint8_t*)(end); \
 223                 _o += 4 + (_o[2] << 8 | _o[3]))
 224
 225
 226 struct dhcpv6_server_cand {
 227         bool has_noaddravail;
 228         bool wants_reconfigure;
 229         int16_t preference;
 230         uint8_t duid_len;
 231         uint8_t duid[130];
 232         struct in6_addr server_addr;
 233         uint32_t sol_max_rt;
 234         uint32_t inf_max_rt;
 235         void *ia_na;
 236         void *ia_pd;
 237         size_t ia_na_len;
 238         size_t ia_pd_len;
 239 };
 240
 241
 242 enum odhcp6c_state {
 243         STATE_CLIENT_ID,
 244         STATE_SERVER_ID,
 245         STATE_SERVER_CAND,
 246         STATE_SERVER_ADDR,
 247         STATE_ORO,
 248         STATE_DNS,
 249         STATE_SEARCH,
 250         STATE_IA_NA,
 251         STATE_IA_PD,
 252         STATE_IA_PD_INIT,
 253         STATE_CUSTOM_OPTS,
 254         STATE_SNTP_IP,
 255         STATE_NTP_IP,
 256         STATE_NTP_FQDN,
 257         STATE_SIP_IP,
 258         STATE_SIP_FQDN,
 259         STATE_RA_ROUTE,
 260         STATE_RA_PREFIX,
 261         STATE_RA_DNS,
 262         STATE_RA_SEARCH,
 263         STATE_AFTR_NAME,
 264         STATE_OPTS,
 265         STATE_CER,
 266         STATE_S46_MAPT,
 267         STATE_S46_MAPE,
 268         STATE_S46_LW,
 269         STATE_PASSTHRU,
 270         _STATE_MAX
 271 };
 272
 273
 274 struct icmp6_opt {
 275         uint8_t type;
 276         uint8_t len;
 277         uint8_t data[6];
 278 };
 279
 280
 281 enum dhcpv6_mode {
 282         DHCPV6_UNKNOWN = -1,
 283         DHCPV6_STATELESS,
 284         DHCPV6_STATEFUL
 285 };
 286
 287 enum ra_config {
 288         RA_RDNSS_DEFAULT_LIFETIME = 1,
 289 };
 290
 291 enum odhcp6c_ia_mode {
 292         IA_MODE_NONE,
 293         IA_MODE_TRY,
 294         IA_MODE_FORCE,
 295 };
 296
 297
 298 struct odhcp6c_entry {
 299         struct in6_addr router;
 300         uint8_t auxlen;
 301         uint8_t length;
 302         int16_t priority;
 303         struct in6_addr target;
 304         uint32_t valid;
 305         uint32_t preferred;
 306         uint32_t t1;
 307         uint32_t t2;
 308         uint32_t iaid;
 309         uint8_t auxtarget[];
 310 };
 311
 312 // Include padding after auxtarget to align the next entry
 313 #define odhcp6c_entry_size(entry) \
 314         (sizeof(struct odhcp6c_entry) + (((entry)->auxlen + 3) & ~3))
 315
 316 #define odhcp6c_next_entry(entry) \
 317         ((struct odhcp6c_entry *)((uint8_t *)(entry) + odhcp6c_entry_size(entry)))
 318
 319
 320 struct odhcp6c_request_prefix {
 321         uint32_t iaid;
 322         uint16_t length;
 323 };
 324
 325 enum odhcp6c_opt_flags {
 326         OPT_U8 = 0,
 327         OPT_IP6,
 328         OPT_DNS_STR,
 329         OPT_USER_CLASS,
 330         OPT_MASK_SIZE = 0x0F,
 331         OPT_ARRAY = 0x10,
 332         OPT_INTERNAL = 0x20,
 333 };
 334
 335 struct odhcp6c_opt {
 336         uint16_t code;
 337         uint8_t flags;
 338         const char *str;
 339 };
 340
 341 int init_dhcpv6(const char *ifname, unsigned int client_options, int sol_timeout);
 342 int dhcpv6_set_ia_mode(enum odhcp6c_ia_mode na, enum odhcp6c_ia_mode pd);
 343 int dhcpv6_request(enum dhcpv6_msg type);
 344 int dhcpv6_poll_reconfigure(void);
 345 int dhcpv6_promote_server_cand(void);
 346
 347 int init_rtnetlink(void);
 348 int set_rtnetlink_addr(int ifindex, const struct in6_addr *addr,
 349                 uint32_t pref, uint32_t valid);
 350
 351 int ra_conf_hoplimit(int newvalue);
 352 int ra_conf_mtu(int newvalue);
 353 int ra_conf_reachable(int newvalue);
 354 int ra_conf_retransmit(int newvalue);
 355
 356 int script_init(const char *path, const char *ifname);
 357 ssize_t script_unhexlify(uint8_t *dst, size_t len, const char *src);
 358 void script_call(const char *status, int delay, bool resume);
 359
 360 bool odhcp6c_signal_process(void);
 361 uint64_t odhcp6c_get_milli_time(void);
 362 int odhcp6c_random(void *buf, size_t len);
 363 bool odhcp6c_is_bound(void);
 364 bool odhcp6c_addr_in_scope(const struct in6_addr *addr);
 365
 366 // State manipulation
 367 void odhcp6c_clear_state(enum odhcp6c_state state);
 368 int odhcp6c_add_state(enum odhcp6c_state state, const void *data, size_t len);
 369 void odhcp6c_append_state(enum odhcp6c_state state, const void *data, size_t len);
 370 int odhcp6c_insert_state(enum odhcp6c_state state, size_t offset, const void *data, size_t len);
 371 size_t odhcp6c_remove_state(enum odhcp6c_state state, size_t offset, size_t len);
 372 void* odhcp6c_move_state(enum odhcp6c_state state, size_t *len);
 373 void* odhcp6c_get_state(enum odhcp6c_state state, size_t *len);
 374
 375 // Entry manipulation
 376 bool odhcp6c_update_entry(enum odhcp6c_state state, struct odhcp6c_entry *new,
 377                                 uint32_t safe, unsigned int holdoff_interval);
 378
 379 void odhcp6c_expire(void);
 380 uint32_t odhcp6c_elapsed(void);
 381 struct odhcp6c_opt *odhcp6c_find_opt(const uint16_t code);