src/odhcpd.h

   1 /**
   2  * Copyright (C) 2012-2013 Steven Barth <steven@midlink.org>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License v2 as published by
   6  * the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  *
  13  */
  14
  15 #pragma once
  16 #include <netinet/in.h>
  17 #include <netinet/icmp6.h>
  18 #include <netinet/ether.h>
  19 #include <stdbool.h>
  20 #include <syslog.h>
  21
  22 #include <libubox/blobmsg.h>
  23 #include <libubox/list.h>
  24 #include <libubox/uloop.h>
  25 #include <libubox/avl.h>
  26 #include <libubox/ustream.h>
  27 #include <libubox/vlist.h>
  28
  29 #define min(a, b) (((a) < (b)) ? (a) : (b))
  30 #define max(a, b) (((a) > (b)) ? (a) : (b))
  31
  32 // RFC 6106 defines this router advertisement option
  33 #define ND_OPT_ROUTE_INFO 24
  34 #define ND_OPT_RECURSIVE_DNS 25
  35 #define ND_OPT_DNS_SEARCH 31
  36
  37 // RFC 8781 defines PREF64 option
  38 #define ND_OPT_PREF64 38
  39
  40 #define INFINITE_VALID(x) ((x) == 0)
  41
  42 #define _unused __attribute__((unused))
  43 #define _packed __attribute__((packed))
  44
  45 #define ALL_IPV6_NODES "ff02::1"
  46 #define ALL_IPV6_ROUTERS "ff02::2"
  47
  48 #define NTP_SUBOPTION_SRV_ADDR 1
  49 #define NTP_SUBOPTION_MC_ADDR 2
  50 #define NTP_SUBOPTION_SRV_FQDN 3
  51 #define IPV6_ADDR_LEN 16
  52
  53 #define IN6_IS_ADDR_ULA(a) (((a)->s6_addr32[0] & htonl(0xfe000000)) == htonl(0xfc000000))
  54
  55 #define ADDR_MATCH_PIO_FILTER(_addr, iface) (odhcpd_bmemcmp(&(_addr)->addr, \
  56                                                             &(iface)->pio_filter_addr, \
  57                                                             (iface)->pio_filter_length) != 0 || \
  58                                              (_addr)->prefix < (iface)->pio_filter_length)
  59
  60 struct interface;
  61 struct nl_sock;
  62 extern struct vlist_tree leases;
  63 extern struct config config;
  64
  65 struct odhcpd_event {
  66         struct uloop_fd uloop;
  67         void (*handle_dgram)(void *addr, void *data, size_t len,
  68                         struct interface *iface, void *dest_addr);
  69         void (*handle_error)(struct odhcpd_event *e, int error);
  70         void (*recv_msgs)(struct odhcpd_event *e);
  71 };
  72
  73 typedef int (*send_reply_cb_t)(const void *buf, size_t len,
  74                                const struct sockaddr *dest, socklen_t dest_len,
  75                                void *opaque);
  76
  77 typedef void (*dhcpv6_binding_cb_handler_t)(struct in6_addr *addr, int prefix,
  78                                             uint32_t pref, uint32_t valid,
  79                                             void *arg);
  80
  81 union if_addr {
  82         struct in_addr in;
  83         struct in6_addr in6;
  84 };
  85
  86 struct netevent_handler_info {
  87         struct interface *iface;
  88         union {
  89                 struct {
  90                         union if_addr dst;
  91                         uint8_t dst_len;
  92                         union if_addr gateway;
  93                 } rt;
  94                 struct {
  95                         union if_addr dst;
  96                         uint16_t state;
  97                         uint8_t flags;
  98                 } neigh;
  99                 struct {
 100                         struct odhcpd_ipaddr *addrs;
 101                         size_t len;
 102                 } addrs_old;
 103                 union if_addr addr;
 104         };
 105 };
 106
 107 enum netevents {
 108         NETEV_IFINDEX_CHANGE,
 109         NETEV_ADDR_ADD,
 110         NETEV_ADDR_DEL,
 111         NETEV_ADDRLIST_CHANGE,
 112         NETEV_ADDR6_ADD,
 113         NETEV_ADDR6_DEL,
 114         NETEV_ADDR6LIST_CHANGE,
 115         NETEV_ROUTE6_ADD,
 116         NETEV_ROUTE6_DEL,
 117         NETEV_NEIGH6_ADD,
 118         NETEV_NEIGH6_DEL,
 119 };
 120
 121 struct netevent_handler {
 122         struct list_head head;
 123         void (*cb) (unsigned long event, struct netevent_handler_info *info);
 124 };
 125
 126 struct odhcpd_ipaddr {
 127         union if_addr addr;
 128         uint8_t prefix;
 129         uint32_t preferred_lt;
 130         uint32_t valid_lt;
 131
 132         union {
 133                 /* ipv6 only */
 134                 struct {
 135                         uint8_t dprefix;
 136                         uint8_t invalid_advertisements;
 137                         bool tentative;
 138                 };
 139
 140                 /* ipv4 only */
 141                 struct in_addr broadcast;
 142         };
 143 };
 144
 145 enum odhcpd_mode {
 146         MODE_DISABLED,
 147         MODE_SERVER,
 148         MODE_RELAY,
 149         MODE_HYBRID
 150 };
 151
 152
 153 enum odhcpd_assignment_flags {
 154         OAF_TENTATIVE           = (1 << 0),
 155         OAF_BOUND               = (1 << 1),
 156         OAF_STATIC              = (1 << 2),
 157         OAF_BROKEN_HOSTNAME     = (1 << 3),
 158         OAF_DHCPV4              = (1 << 4),
 159         OAF_DHCPV6_NA           = (1 << 5),
 160         OAF_DHCPV6_PD           = (1 << 6),
 161 };
 162
 163 struct config {
 164         bool legacy;
 165         bool main_dhcpv4;
 166         char *dhcp_cb;
 167         char *dhcp_statefile;
 168         char *dhcp_hostsfile;
 169         int log_level;
 170 };
 171
 172
 173 struct lease {
 174         struct vlist_node node;
 175         struct list_head assignments;
 176         uint32_t ipaddr;
 177         uint64_t hostid;
 178         struct ether_addr mac;
 179         uint16_t duid_len;
 180         uint8_t *duid;
 181         uint32_t leasetime;
 182         char *hostname;
 183 };
 184
 185 enum {
 186         LEASE_ATTR_IP,
 187         LEASE_ATTR_MAC,
 188         LEASE_ATTR_DUID,
 189         LEASE_ATTR_HOSTID,
 190         LEASE_ATTR_LEASETIME,
 191         LEASE_ATTR_NAME,
 192         LEASE_ATTR_MAX
 193 };
 194
 195 struct odhcpd_ref_ip;
 196
 197 struct dhcp_assignment {
 198         struct list_head head;
 199         struct list_head lease_list;
 200
 201         void (*dhcp_free_cb)(struct dhcp_assignment *a);
 202
 203         struct interface *iface;
 204         struct lease *lease;
 205
 206         struct sockaddr_in6 peer;
 207         time_t valid_until;
 208         time_t preferred_until;
 209
 210 #define fr_timer        reconf_timer
 211         struct uloop_timeout reconf_timer;
 212 #define accept_fr_nonce accept_reconf
 213         bool accept_reconf;
 214 #define fr_cnt          reconf_cnt
 215         int reconf_cnt;
 216         uint8_t key[16];
 217         struct odhcpd_ref_ip *fr_ip;
 218
 219         uint32_t addr;
 220         union {
 221                 uint64_t assigned_host_id;
 222                 uint32_t assigned_subnet_id;
 223         };
 224         uint32_t iaid;
 225         uint8_t length; // length == 128 -> IA_NA, length <= 64 -> IA_PD
 226
 227         struct odhcpd_ipaddr *managed;
 228         ssize_t managed_size;
 229         struct ustream_fd managed_sock;
 230
 231         unsigned int flags;
 232         uint32_t leasetime;
 233         char *hostname;
 234         char *reqopts;
 235 #define hwaddr          mac
 236         uint8_t mac[6];
 237
 238         uint16_t clid_len;
 239         uint8_t clid_data[];
 240 };
 241
 242
 243 struct interface {
 244         struct avl_node avl;
 245
 246         int ifflags;
 247         int ifindex;
 248         char *ifname;
 249         const char *name;
 250
 251         // IPv6 runtime data
 252         struct odhcpd_ipaddr *addr6;
 253         size_t addr6_len;
 254         struct odhcpd_ipaddr *invalid_addr6;
 255         size_t invalid_addr6_len;
 256
 257         // RA runtime data
 258         struct odhcpd_event router_event;
 259         struct uloop_timeout timer_rs;
 260         uint32_t ra_sent;
 261
 262         // DHCPv6 runtime data
 263         struct odhcpd_event dhcpv6_event;
 264         struct list_head ia_assignments;
 265
 266         // NDP runtime data
 267         struct odhcpd_event ndp_event;
 268         int ndp_ping_fd;
 269
 270         // IPv4 runtime data
 271         struct odhcpd_ipaddr *addr4;
 272         size_t addr4_len;
 273
 274         // DHCPv4 runtime data
 275         struct odhcpd_event dhcpv4_event;
 276         struct list_head dhcpv4_assignments;
 277         struct list_head dhcpv4_fr_ips;
 278
 279         // Managed PD
 280         char dhcpv6_pd_manager[128];
 281         struct in6_addr dhcpv6_pd_cer;
 282
 283         // Services
 284         enum odhcpd_mode ra;
 285         enum odhcpd_mode dhcpv6;
 286         enum odhcpd_mode ndp;
 287         enum odhcpd_mode dhcpv4;
 288
 289         // Config
 290         bool inuse;
 291         bool external;
 292         bool master;
 293         bool ignore;
 294         bool always_rewrite_dns;
 295         bool dns_service;
 296
 297         // NDP
 298         int learn_routes;
 299
 300         // RA
 301         uint8_t ra_flags;
 302         bool ra_slaac;
 303         bool ra_not_onlink;
 304         bool ra_advrouter;
 305         bool ra_useleasetime;
 306         bool ra_dns;
 307         uint8_t pref64_length;
 308         struct in6_addr pref64_addr;
 309         bool no_dynamic_dhcp;
 310         bool have_link_local;
 311         uint8_t pio_filter_length;
 312         struct in6_addr pio_filter_addr;
 313         int default_router;
 314         int route_preference;
 315         int ra_maxinterval;
 316         int ra_mininterval;
 317         int ra_lifetime;
 318         uint32_t ra_reachabletime;
 319         uint32_t ra_retranstime;
 320         uint32_t ra_hoplimit;
 321         int ra_mtu;
 322         uint32_t preferred_lifetime;
 323
 324         // DHCP
 325         uint32_t dhcp_leasetime;
 326
 327         // DHCPv4
 328         struct in_addr dhcpv4_start;
 329         struct in_addr dhcpv4_end;
 330         struct in_addr dhcpv4_start_ip;
 331         struct in_addr dhcpv4_end_ip;
 332         struct in_addr dhcpv4_local;
 333         struct in_addr dhcpv4_bcast;
 334         struct in_addr dhcpv4_mask;
 335         struct in_addr *dhcpv4_router;
 336         size_t dhcpv4_router_cnt;
 337         struct in_addr *dhcpv4_dns;
 338         size_t dhcpv4_dns_cnt;
 339         bool dhcpv4_forcereconf;
 340
 341         // DNS
 342         struct in6_addr *dns;
 343         size_t dns_cnt;
 344         uint8_t *search;
 345         size_t search_len;
 346
 347         // DHCPV6
 348         void *dhcpv6_raw;
 349         size_t dhcpv6_raw_len;
 350         bool dhcpv6_assignall;
 351         bool dhcpv6_pd;
 352         bool dhcpv6_na;
 353         uint32_t dhcpv6_hostid_len;
 354         uint32_t dhcpv6_pd_min_len; // minimum delegated prefix length
 355
 356         char *upstream;
 357         size_t upstream_len;
 358
 359         char *filter_class;
 360
 361         // NTP
 362         struct in_addr *dhcpv4_ntp;
 363         size_t dhcpv4_ntp_cnt;
 364         uint8_t *dhcpv6_ntp;
 365         uint16_t dhcpv6_ntp_len;
 366         size_t dhcpv6_ntp_cnt;
 367
 368         // SNTP
 369         struct in6_addr *dhcpv6_sntp;
 370         size_t dhcpv6_sntp_cnt;
 371 };
 372
 373 extern struct avl_tree interfaces;
 374 extern const struct blobmsg_policy lease_attrs[LEASE_ATTR_MAX];
 375
 376 inline static void free_assignment(struct dhcp_assignment *a)
 377 {
 378         list_del(&a->head);
 379         list_del(&a->lease_list);
 380
 381         if (a->dhcp_free_cb)
 382                 a->dhcp_free_cb(a);
 383
 384         free(a->hostname);
 385         free(a->reqopts);
 386         free(a);
 387 }
 388
 389 inline static struct dhcp_assignment *alloc_assignment(size_t extra_len)
 390 {
 391         struct dhcp_assignment *a = calloc(1, sizeof(*a) + extra_len);
 392
 393         if (!a)
 394                 return NULL;
 395
 396         INIT_LIST_HEAD(&a->head);
 397         INIT_LIST_HEAD(&a->lease_list);
 398
 399         return a;
 400 }
 401
 402 // Exported main functions
 403 int odhcpd_register(struct odhcpd_event *event);
 404 int odhcpd_deregister(struct odhcpd_event *event);
 405 void odhcpd_process(struct odhcpd_event *event);
 406
 407 ssize_t odhcpd_send(int socket, struct sockaddr_in6 *dest,
 408                 struct iovec *iov, size_t iov_len,
 409                 const struct interface *iface);
 410 int odhcpd_get_interface_dns_addr(const struct interface *iface,
 411                 struct in6_addr *addr);
 412 int odhcpd_get_interface_config(const char *ifname, const char *what);
 413 int odhcpd_get_mac(const struct interface *iface, uint8_t mac[6]);
 414 int odhcpd_get_flags(const struct interface *iface);
 415 struct interface* odhcpd_get_interface_by_index(int ifindex);
 416 int odhcpd_urandom(void *data, size_t len);
 417
 418 void odhcpd_run(void);
 419 time_t odhcpd_time(void);
 420 ssize_t odhcpd_unhexlify(uint8_t *dst, size_t len, const char *src);
 421 void odhcpd_hexlify(char *dst, const uint8_t *src, size_t len);
 422 const char *odhcpd_print_mac(const uint8_t *mac, const size_t len);
 423
 424 int odhcpd_bmemcmp(const void *av, const void *bv, size_t bits);
 425 void odhcpd_bmemcpy(void *av, const void *bv, size_t bits);
 426
 427 int odhcpd_netmask2bitlen(bool v6, void *mask);
 428 bool odhcpd_bitlen2netmask(bool v6, unsigned int bits, void *mask);
 429 bool odhcpd_valid_hostname(const char *name);
 430
 431 int config_parse_interface(void *data, size_t len, const char *iname, bool overwrite);
 432 struct lease *config_find_lease_by_duid(const uint8_t *duid, const uint16_t len);
 433 struct lease *config_find_lease_by_mac(const uint8_t *mac);
 434 struct lease *config_find_lease_by_hostid(const uint64_t hostid);
 435 struct lease *config_find_lease_by_ipaddr(const uint32_t ipaddr);
 436 int set_lease_from_blobmsg(struct blob_attr *ba);
 437
 438 #ifdef WITH_UBUS
 439 int ubus_init(void);
 440 const char* ubus_get_ifname(const char *name);
 441 void ubus_apply_network(void);
 442 bool ubus_has_prefix(const char *name, const char *ifname);
 443 void ubus_bcast_dhcp_event(const char *type, const uint8_t *mac, const size_t mac_len,
 444                 const struct in_addr *addr, const char *name, const char *interface);
 445 #endif
 446
 447 ssize_t dhcpv6_ia_handle_IAs(uint8_t *buf, size_t buflen, struct interface *iface,
 448                 const struct sockaddr_in6 *addr, const void *data, const uint8_t *end);
 449 int dhcpv6_ia_init(void);
 450 int dhcpv6_ia_setup_interface(struct interface *iface, bool enable);
 451 void dhcpv6_ia_enum_addrs(struct interface *iface, struct dhcp_assignment *c, time_t now,
 452                                 dhcpv6_binding_cb_handler_t func, void *arg);
 453 void dhcpv6_ia_write_statefile(void);
 454
 455 int netlink_add_netevent_handler(struct netevent_handler *hdlr);
 456 ssize_t netlink_get_interface_addrs(const int ifindex, bool v6,
 457                 struct odhcpd_ipaddr **addrs);
 458 ssize_t netlink_get_interface_linklocal(int ifindex, struct odhcpd_ipaddr **addrs);
 459 int netlink_get_interface_proxy_neigh(int ifindex, const struct in6_addr *addr);
 460 int netlink_setup_route(const struct in6_addr *addr, const int prefixlen,
 461                 const int ifindex, const struct in6_addr *gw,
 462                 const uint32_t metric, const bool add);
 463 int netlink_setup_proxy_neigh(const struct in6_addr *addr,
 464                 const int ifindex, const bool add);
 465 int netlink_setup_addr(struct odhcpd_ipaddr *addr,
 466                 const int ifindex, const bool v6, const bool add);
 467 void netlink_dump_neigh_table(const bool proxy);
 468 void netlink_dump_addr_table(const bool v6);
 469
 470 // Exported module initializers
 471 int netlink_init(void);
 472 int router_init(void);
 473 int dhcpv6_init(void);
 474 int ndp_init(void);
 475 #ifdef DHCPV4_SUPPORT
 476 int dhcpv4_init(void);
 477
 478 int dhcpv4_setup_interface(struct interface *iface, bool enable);
 479 void dhcpv4_handle_msg(void *addr, void *data, size_t len,
 480                        struct interface *iface, _unused void *dest_addr,
 481                        send_reply_cb_t send_reply, void *opaque);
 482 #endif
 483 int router_setup_interface(struct interface *iface, bool enable);
 484 int dhcpv6_setup_interface(struct interface *iface, bool enable);
 485 int ndp_setup_interface(struct interface *iface, bool enable);
 486 void reload_services(struct interface *iface);
 487
 488 void odhcpd_reload(void);