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 // RFC 6106 defines this router advertisement option
  30 #define ND_OPT_ROUTE_INFO 24
  31 #define ND_OPT_RECURSIVE_DNS 25
  32 #define ND_OPT_DNS_SEARCH 31
  33
  34 #define INFINITE_VALID(x) ((x) == 0)
  35
  36 #define _unused __attribute__((unused))
  37 #define _packed __attribute__((packed))
  38
  39 #define ALL_IPV6_NODES "ff02::1"
  40 #define ALL_IPV6_ROUTERS "ff02::2"
  41
  42 #define IN6_IS_ADDR_ULA(a) (((a)->s6_addr32[0] & htonl(0xfe000000)) == htonl(0xfc000000))
  43
  44 struct interface;
  45 struct nl_sock;
  46 extern struct vlist_tree leases;
  47 extern struct config config;
  48
  49 struct odhcpd_event {
  50         struct uloop_fd uloop;
  51         void (*handle_dgram)(void *addr, void *data, size_t len,
  52                         struct interface *iface, void *dest_addr);
  53         void (*handle_error)(struct odhcpd_event *e, int error);
  54         void (*recv_msgs)(struct odhcpd_event *e);
  55 };
  56
  57 typedef int (*send_reply_cb_t)(const void *buf, size_t len,
  58                                const struct sockaddr *dest, socklen_t dest_len,
  59                                void *opaque);
  60
  61 typedef void (*dhcpv6_binding_cb_handler_t)(struct in6_addr *addr, int prefix,
  62                                             uint32_t pref, uint32_t valid,
  63                                             void *arg);
  64
  65 union if_addr {
  66         struct in_addr in;
  67         struct in6_addr in6;
  68 };
  69
  70 struct netevent_handler_info {
  71         struct interface *iface;
  72         union {
  73                 struct {
  74                         union if_addr dst;
  75                         uint8_t dst_len;
  76                         union if_addr gateway;
  77                 } rt;
  78                 struct {
  79                         union if_addr dst;
  80                         uint16_t state;
  81                         uint8_t flags;
  82                 } neigh;
  83                 struct {
  84                         struct odhcpd_ipaddr *addrs;
  85                         size_t len;
  86                 } addrs_old;
  87                 union if_addr addr;
  88         };
  89 };
  90
  91 enum netevents {
  92         NETEV_IFINDEX_CHANGE,
  93         NETEV_ADDR_ADD,
  94         NETEV_ADDR_DEL,
  95         NETEV_ADDRLIST_CHANGE,
  96         NETEV_ADDR6_ADD,
  97         NETEV_ADDR6_DEL,
  98         NETEV_ADDR6LIST_CHANGE,
  99         NETEV_ROUTE6_ADD,
 100         NETEV_ROUTE6_DEL,
 101         NETEV_NEIGH6_ADD,
 102         NETEV_NEIGH6_DEL,
 103 };
 104
 105 struct netevent_handler {
 106         struct list_head head;
 107         void (*cb) (unsigned long event, struct netevent_handler_info *info);
 108 };
 109
 110 struct odhcpd_ipaddr {
 111         union if_addr addr;
 112         uint8_t prefix;
 113         uint32_t preferred;
 114         uint32_t valid;
 115
 116         /* ipv6 only */
 117         uint8_t dprefix;
 118
 119         /* ipv4 only */
 120         struct in_addr broadcast;
 121 };
 122
 123 enum odhcpd_mode {
 124         MODE_DISABLED,
 125         MODE_SERVER,
 126         MODE_RELAY,
 127         MODE_HYBRID
 128 };
 129
 130
 131 enum odhcpd_assignment_flags {
 132         OAF_TENTATIVE           = (1 << 0),
 133         OAF_BOUND               = (1 << 1),
 134         OAF_STATIC              = (1 << 2),
 135         OAF_BROKEN_HOSTNAME     = (1 << 3),
 136         OAF_DHCPV4              = (1 << 4),
 137         OAF_DHCPV6_NA           = (1 << 5),
 138         OAF_DHCPV6_PD           = (1 << 6),
 139 };
 140
 141 struct config {
 142         bool legacy;
 143         bool main_dhcpv4;
 144         char *dhcp_cb;
 145         char *dhcp_statefile;
 146         int log_level;
 147 };
 148
 149
 150 struct lease {
 151         struct vlist_node node;
 152         struct list_head assignments;
 153         uint32_t ipaddr;
 154         uint32_t hostid;
 155         struct ether_addr mac;
 156         uint16_t duid_len;
 157         uint8_t *duid;
 158         uint32_t leasetime;
 159         char *hostname;
 160 };
 161
 162
 163 struct odhcpd_ref_ip;
 164
 165 struct dhcp_assignment {
 166         struct list_head head;
 167         struct list_head lease_list;
 168
 169         void (*dhcp_free_cb)(struct dhcp_assignment *a);
 170
 171         struct interface *iface;
 172         struct lease *lease;
 173
 174         struct sockaddr_in6 peer;
 175         time_t valid_until;
 176
 177 #define fr_timer        reconf_timer
 178         struct uloop_timeout reconf_timer;
 179 #define accept_fr_nonce accept_reconf
 180         bool accept_reconf;
 181 #define fr_cnt          reconf_cnt
 182         int reconf_cnt;
 183         uint8_t key[16];
 184         struct odhcpd_ref_ip *fr_ip;
 185
 186         uint32_t addr;
 187         uint32_t assigned;
 188         uint32_t iaid;
 189         uint8_t length; // length == 128 -> IA_NA, length <= 64 -> IA_PD
 190
 191         struct odhcpd_ipaddr *managed;
 192         ssize_t managed_size;
 193         struct ustream_fd managed_sock;
 194
 195         unsigned int flags;
 196         uint32_t leasetime;
 197         char *hostname;
 198         char *reqopts;
 199 #define hwaddr          mac
 200         uint8_t mac[6];
 201
 202         uint16_t clid_len;
 203         uint8_t clid_data[];
 204 };
 205
 206
 207 struct interface {
 208         struct avl_node avl;
 209
 210         int ifindex;
 211         char *ifname;
 212         const char *name;
 213
 214         // IPv6 runtime data
 215         struct odhcpd_ipaddr *addr6;
 216         size_t addr6_len;
 217
 218         // RA runtime data
 219         struct odhcpd_event router_event;
 220         struct uloop_timeout timer_rs;
 221         uint32_t ra_sent;
 222
 223         // DHCPv6 runtime data
 224         struct odhcpd_event dhcpv6_event;
 225         struct list_head ia_assignments;
 226
 227         // NDP runtime data
 228         struct odhcpd_event ndp_event;
 229         int ndp_ping_fd;
 230
 231         // IPv4 runtime data
 232         struct odhcpd_ipaddr *addr4;
 233         size_t addr4_len;
 234
 235         // DHCPv4 runtime data
 236         struct odhcpd_event dhcpv4_event;
 237         struct list_head dhcpv4_assignments;
 238         struct list_head dhcpv4_fr_ips;
 239
 240         // Managed PD
 241         char dhcpv6_pd_manager[128];
 242         struct in6_addr dhcpv6_pd_cer;
 243
 244         // Services
 245         enum odhcpd_mode ra;
 246         enum odhcpd_mode dhcpv6;
 247         enum odhcpd_mode ndp;
 248         enum odhcpd_mode dhcpv4;
 249
 250         // Config
 251         bool inuse;
 252         bool external;
 253         bool master;
 254         bool ignore;
 255         bool always_rewrite_dns;
 256         bool dns_service;
 257
 258         // NDP
 259         int learn_routes;
 260
 261         // RA
 262         uint8_t ra_flags;
 263         bool ra_slaac;
 264         bool ra_not_onlink;
 265         bool ra_advrouter;
 266         bool ra_useleasetime;
 267         bool ra_dns;
 268         bool no_dynamic_dhcp;
 269         uint8_t pio_filter_length;
 270         struct in6_addr pio_filter_addr;
 271         int default_router;
 272         int route_preference;
 273         int ra_maxinterval;
 274         int ra_mininterval;
 275         int ra_lifetime;
 276         uint32_t ra_reachabletime;
 277         uint32_t ra_retranstime;
 278         uint32_t ra_hoplimit;
 279         int ra_mtu;
 280
 281         // DHCP
 282         uint32_t dhcp_leasetime;
 283
 284         // DHCPv4
 285         struct in_addr dhcpv4_start;
 286         struct in_addr dhcpv4_end;
 287         struct in_addr dhcpv4_start_ip;
 288         struct in_addr dhcpv4_end_ip;
 289         struct in_addr dhcpv4_local;
 290         struct in_addr dhcpv4_bcast;
 291         struct in_addr dhcpv4_mask;
 292         struct in_addr *dhcpv4_router;
 293         size_t dhcpv4_router_cnt;
 294         struct in_addr *dhcpv4_dns;
 295         size_t dhcpv4_dns_cnt;
 296         bool dhcpv4_forcereconf;
 297
 298         // DNS
 299         struct in6_addr *dns;
 300         size_t dns_cnt;
 301         uint8_t *search;
 302         size_t search_len;
 303
 304         // DHCPV6
 305         void *dhcpv6_raw;
 306         size_t dhcpv6_raw_len;
 307         bool dhcpv6_assignall;
 308         bool dhcpv6_pd;
 309         bool dhcpv6_na;
 310
 311         char *upstream;
 312         size_t upstream_len;
 313
 314         char *filter_class;
 315 };
 316
 317 extern struct avl_tree interfaces;
 318
 319 inline static void free_assignment(struct dhcp_assignment *a)
 320 {
 321         list_del(&a->head);
 322         list_del(&a->lease_list);
 323
 324         if (a->dhcp_free_cb)
 325                 a->dhcp_free_cb(a);
 326
 327         free(a->hostname);
 328         free(a->reqopts);
 329         free(a);
 330 }
 331
 332 inline static struct dhcp_assignment *alloc_assignment(size_t extra_len)
 333 {
 334         struct dhcp_assignment *a = calloc(1, sizeof(*a) + extra_len);
 335
 336         if (!a)
 337                 return NULL;
 338
 339         INIT_LIST_HEAD(&a->head);
 340         INIT_LIST_HEAD(&a->lease_list);
 341
 342         return a;
 343 }
 344
 345 // Exported main functions
 346 int odhcpd_register(struct odhcpd_event *event);
 347 int odhcpd_deregister(struct odhcpd_event *event);
 348 void odhcpd_process(struct odhcpd_event *event);
 349
 350 ssize_t odhcpd_send(int socket, struct sockaddr_in6 *dest,
 351                 struct iovec *iov, size_t iov_len,
 352                 const struct interface *iface);
 353 int odhcpd_get_interface_dns_addr(const struct interface *iface,
 354                 struct in6_addr *addr);
 355 int odhcpd_get_interface_config(const char *ifname, const char *what);
 356 int odhcpd_get_mac(const struct interface *iface, uint8_t mac[6]);
 357 struct interface* odhcpd_get_interface_by_index(int ifindex);
 358 int odhcpd_urandom(void *data, size_t len);
 359
 360 void odhcpd_run(void);
 361 time_t odhcpd_time(void);
 362 ssize_t odhcpd_unhexlify(uint8_t *dst, size_t len, const char *src);
 363 void odhcpd_hexlify(char *dst, const uint8_t *src, size_t len);
 364 const char *odhcpd_print_mac(const uint8_t *mac, const size_t len);
 365
 366 int odhcpd_bmemcmp(const void *av, const void *bv, size_t bits);
 367 void odhcpd_bmemcpy(void *av, const void *bv, size_t bits);
 368
 369 int odhcpd_netmask2bitlen(bool v6, void *mask);
 370 bool odhcpd_bitlen2netmask(bool v6, unsigned int bits, void *mask);
 371 bool odhcpd_valid_hostname(const char *name);
 372
 373 int config_parse_interface(void *data, size_t len, const char *iname, bool overwrite);
 374 struct lease *config_find_lease_by_duid(const uint8_t *duid, const uint16_t len);
 375 struct lease *config_find_lease_by_mac(const uint8_t *mac);
 376 struct lease *config_find_lease_by_hostid(const uint32_t hostid);
 377 struct lease *config_find_lease_by_ipaddr(const uint32_t ipaddr);
 378
 379 #ifdef WITH_UBUS
 380 int ubus_init(void);
 381 const char* ubus_get_ifname(const char *name);
 382 void ubus_apply_network(void);
 383 bool ubus_has_prefix(const char *name, const char *ifname);
 384 void ubus_bcast_dhcp_event(const char *type, const uint8_t *mac, const size_t mac_len,
 385                 const struct in_addr *addr, const char *name, const char *interface);
 386 #endif
 387
 388 ssize_t dhcpv6_ia_handle_IAs(uint8_t *buf, size_t buflen, struct interface *iface,
 389                 const struct sockaddr_in6 *addr, const void *data, const uint8_t *end);
 390 int dhcpv6_ia_init(void);
 391 int dhcpv6_ia_setup_interface(struct interface *iface, bool enable);
 392 void dhcpv6_ia_enum_addrs(struct interface *iface, struct dhcp_assignment *c, time_t now,
 393                                 dhcpv6_binding_cb_handler_t func, void *arg);
 394 void dhcpv6_ia_write_statefile(void);
 395
 396 int netlink_add_netevent_handler(struct netevent_handler *hdlr);
 397 ssize_t netlink_get_interface_addrs(const int ifindex, bool v6,
 398                 struct odhcpd_ipaddr **addrs);
 399 int netlink_get_interface_proxy_neigh(int ifindex, const struct in6_addr *addr);
 400 int netlink_setup_route(const struct in6_addr *addr, const int prefixlen,
 401                 const int ifindex, const struct in6_addr *gw,
 402                 const uint32_t metric, const bool add);
 403 int netlink_setup_proxy_neigh(const struct in6_addr *addr,
 404                 const int ifindex, const bool add);
 405 int netlink_setup_addr(struct odhcpd_ipaddr *addr,
 406                 const int ifindex, const bool v6, const bool add);
 407 void netlink_dump_neigh_table(const bool proxy);
 408 void netlink_dump_addr_table(const bool v6);
 409
 410 // Exported module initializers
 411 int netlink_init(void);
 412 int router_init(void);
 413 int dhcpv6_init(void);
 414 int ndp_init(void);
 415 #ifdef DHCPV4_SUPPORT
 416 int dhcpv4_init(void);
 417
 418 int dhcpv4_setup_interface(struct interface *iface, bool enable);
 419 void dhcpv4_handle_msg(void *addr, void *data, size_t len,
 420                        struct interface *iface, _unused void *dest_addr,
 421                        send_reply_cb_t send_reply, void *opaque);
 422 #endif
 423 int router_setup_interface(struct interface *iface, bool enable);
 424 int dhcpv6_setup_interface(struct interface *iface, bool enable);
 425 int ndp_setup_interface(struct interface *iface, bool enable);
 426
 427 void odhcpd_reload(void);