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