Travis Geiselbrecht | 1d0df69 | 2008-09-01 02:26:09 -0700 | [diff] [blame^] | 1 | /** |
| 2 | * @file |
| 3 | * |
| 4 | * Dynamic Host Configuration Protocol client |
| 5 | */ |
| 6 | |
| 7 | /* |
| 8 | * |
| 9 | * Copyright (c) 2001-2004 Leon Woestenberg <leon.woestenberg@gmx.net> |
| 10 | * Copyright (c) 2001-2004 Axon Digital Design B.V., The Netherlands. |
| 11 | * All rights reserved. |
| 12 | * |
| 13 | * Redistribution and use in source and binary forms, with or without modification, |
| 14 | * are permitted provided that the following conditions are met: |
| 15 | * |
| 16 | * 1. Redistributions of source code must retain the above copyright notice, |
| 17 | * this list of conditions and the following disclaimer. |
| 18 | * 2. Redistributions in binary form must reproduce the above copyright notice, |
| 19 | * this list of conditions and the following disclaimer in the documentation |
| 20 | * and/or other materials provided with the distribution. |
| 21 | * 3. The name of the author may not be used to endorse or promote products |
| 22 | * derived from this software without specific prior written permission. |
| 23 | * |
| 24 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED |
| 25 | * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF |
| 26 | * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT |
| 27 | * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, |
| 28 | * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT |
| 29 | * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| 30 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| 31 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING |
| 32 | * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY |
| 33 | * OF SUCH DAMAGE. |
| 34 | * |
| 35 | * This file is a contribution to the lwIP TCP/IP stack. |
| 36 | * The Swedish Institute of Computer Science and Adam Dunkels |
| 37 | * are specifically granted permission to redistribute this |
| 38 | * source code. |
| 39 | * |
| 40 | * Author: Leon Woestenberg <leon.woestenberg@gmx.net> |
| 41 | * |
| 42 | * This is a DHCP client for the lwIP TCP/IP stack. It aims to conform |
| 43 | * with RFC 2131 and RFC 2132. |
| 44 | * |
| 45 | * TODO: |
| 46 | * - Proper parsing of DHCP messages exploiting file/sname field overloading. |
| 47 | * - Add JavaDoc style documentation (API, internals). |
| 48 | * - Support for interfaces other than Ethernet (SLIP, PPP, ...) |
| 49 | * |
| 50 | * Please coordinate changes and requests with Leon Woestenberg |
| 51 | * <leon.woestenberg@gmx.net> |
| 52 | * |
| 53 | * Integration with your code: |
| 54 | * |
| 55 | * In lwip/dhcp.h |
| 56 | * #define DHCP_COARSE_TIMER_SECS (recommended 60 which is a minute) |
| 57 | * #define DHCP_FINE_TIMER_MSECS (recommended 500 which equals TCP coarse timer) |
| 58 | * |
| 59 | * Then have your application call dhcp_coarse_tmr() and |
| 60 | * dhcp_fine_tmr() on the defined intervals. |
| 61 | * |
| 62 | * dhcp_start(struct netif *netif); |
| 63 | * starts a DHCP client instance which configures the interface by |
| 64 | * obtaining an IP address lease and maintaining it. |
| 65 | * |
| 66 | * Use dhcp_release(netif) to end the lease and use dhcp_stop(netif) |
| 67 | * to remove the DHCP client. |
| 68 | * |
| 69 | */ |
| 70 | |
| 71 | #include <string.h> |
| 72 | |
| 73 | #include "lwip/stats.h" |
| 74 | #include "lwip/mem.h" |
| 75 | #include "lwip/udp.h" |
| 76 | #include "lwip/ip_addr.h" |
| 77 | #include "lwip/netif.h" |
| 78 | #include "lwip/inet.h" |
| 79 | #include "netif/etharp.h" |
| 80 | |
| 81 | #include "lwip/sys.h" |
| 82 | #include "lwip/opt.h" |
| 83 | #include "lwip/dhcp.h" |
| 84 | |
| 85 | #if LWIP_DHCP /* don't build if not configured for use in lwipopt.h */ |
| 86 | |
| 87 | /** global transaction identifier, must be |
| 88 | * unique for each DHCP request. We simply increment, starting |
| 89 | * with this value (easy to match with a packet analyzer) */ |
| 90 | static u32_t xid = 0xABCD0000; |
| 91 | |
| 92 | /** DHCP client state machine functions */ |
| 93 | static void dhcp_handle_ack(struct netif *netif); |
| 94 | static void dhcp_handle_nak(struct netif *netif); |
| 95 | static void dhcp_handle_offer(struct netif *netif); |
| 96 | |
| 97 | static err_t dhcp_discover(struct netif *netif); |
| 98 | static err_t dhcp_select(struct netif *netif); |
| 99 | static void dhcp_check(struct netif *netif); |
| 100 | static void dhcp_bind(struct netif *netif); |
| 101 | static err_t dhcp_decline(struct netif *netif); |
| 102 | static err_t dhcp_rebind(struct netif *netif); |
| 103 | static void dhcp_set_state(struct dhcp *dhcp, u8_t new_state); |
| 104 | |
| 105 | /** receive, unfold, parse and free incoming messages */ |
| 106 | static void dhcp_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, struct ip_addr *addr, u16_t port); |
| 107 | static err_t dhcp_unfold_reply(struct dhcp *dhcp); |
| 108 | static u8_t *dhcp_get_option_ptr(struct dhcp *dhcp, u8_t option_type); |
| 109 | static u8_t dhcp_get_option_byte(u8_t *ptr); |
| 110 | static u16_t dhcp_get_option_short(u8_t *ptr); |
| 111 | static u32_t dhcp_get_option_long(u8_t *ptr); |
| 112 | static void dhcp_free_reply(struct dhcp *dhcp); |
| 113 | |
| 114 | /** set the DHCP timers */ |
| 115 | static void dhcp_timeout(struct netif *netif); |
| 116 | static void dhcp_t1_timeout(struct netif *netif); |
| 117 | static void dhcp_t2_timeout(struct netif *netif); |
| 118 | |
| 119 | /** build outgoing messages */ |
| 120 | /** create a DHCP request, fill in common headers */ |
| 121 | static err_t dhcp_create_request(struct netif *netif); |
| 122 | /** free a DHCP request */ |
| 123 | static void dhcp_delete_request(struct netif *netif); |
| 124 | /** add a DHCP option (type, then length in bytes) */ |
| 125 | static void dhcp_option(struct dhcp *dhcp, u8_t option_type, u8_t option_len); |
| 126 | /** add option values */ |
| 127 | static void dhcp_option_byte(struct dhcp *dhcp, u8_t value); |
| 128 | static void dhcp_option_short(struct dhcp *dhcp, u16_t value); |
| 129 | static void dhcp_option_long(struct dhcp *dhcp, u32_t value); |
| 130 | /** always add the DHCP options trailer to end and pad */ |
| 131 | static void dhcp_option_trailer(struct dhcp *dhcp); |
| 132 | |
| 133 | /** |
| 134 | * Back-off the DHCP client (because of a received NAK response). |
| 135 | * |
| 136 | * Back-off the DHCP client because of a received NAK. Receiving a |
| 137 | * NAK means the client asked for something non-sensible, for |
| 138 | * example when it tries to renew a lease obtained on another network. |
| 139 | * |
| 140 | * We back-off and will end up restarting a fresh DHCP negotiation later. |
| 141 | * |
| 142 | * @param state pointer to DHCP state structure |
| 143 | */ |
| 144 | static void dhcp_handle_nak(struct netif *netif) { |
| 145 | struct dhcp *dhcp = netif->dhcp; |
| 146 | u16_t msecs = 10 * 1000; |
| 147 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | 3, ("dhcp_handle_nak(netif=%p) %c%c%"U16_F"\n", |
| 148 | (void*)netif, netif->name[0], netif->name[1], (u16_t)netif->num)); |
| 149 | dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS; |
| 150 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | DBG_STATE, ("dhcp_handle_nak(): set request timeout %"U16_F" msecs\n", msecs)); |
| 151 | dhcp_set_state(dhcp, DHCP_BACKING_OFF); |
| 152 | } |
| 153 | |
| 154 | /** |
| 155 | * Checks if the offered IP address is already in use. |
| 156 | * |
| 157 | * It does so by sending an ARP request for the offered address and |
| 158 | * entering CHECKING state. If no ARP reply is received within a small |
| 159 | * interval, the address is assumed to be free for use by us. |
| 160 | */ |
| 161 | static void dhcp_check(struct netif *netif) |
| 162 | { |
| 163 | struct dhcp *dhcp = netif->dhcp; |
| 164 | err_t result; |
| 165 | u16_t msecs; |
| 166 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | 3, ("dhcp_check(netif=%p) %c%c\n", (void *)netif, (s16_t)netif->name[0], |
| 167 | (s16_t)netif->name[1])); |
| 168 | /* create an ARP query for the offered IP address, expecting that no host |
| 169 | responds, as the IP address should not be in use. */ |
| 170 | result = etharp_query(netif, &dhcp->offered_ip_addr, NULL); |
| 171 | if (result != ERR_OK) { |
| 172 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | 2, ("dhcp_check: could not perform ARP query\n")); |
| 173 | } |
| 174 | dhcp->tries++; |
| 175 | msecs = 500; |
| 176 | dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS; |
| 177 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | DBG_STATE, ("dhcp_check(): set request timeout %"U16_F" msecs\n", msecs)); |
| 178 | dhcp_set_state(dhcp, DHCP_CHECKING); |
| 179 | } |
| 180 | |
| 181 | /** |
| 182 | * Remember the configuration offered by a DHCP server. |
| 183 | * |
| 184 | * @param state pointer to DHCP state structure |
| 185 | */ |
| 186 | static void dhcp_handle_offer(struct netif *netif) |
| 187 | { |
| 188 | struct dhcp *dhcp = netif->dhcp; |
| 189 | /* obtain the server address */ |
| 190 | u8_t *option_ptr = dhcp_get_option_ptr(dhcp, DHCP_OPTION_SERVER_ID); |
| 191 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | 3, ("dhcp_handle_offer(netif=%p) %c%c%"U16_F"\n", |
| 192 | (void*)netif, netif->name[0], netif->name[1], (u16_t)netif->num)); |
| 193 | if (option_ptr != NULL) |
| 194 | { |
| 195 | dhcp->server_ip_addr.addr = htonl(dhcp_get_option_long(&option_ptr[2])); |
| 196 | LWIP_DEBUGF(DHCP_DEBUG | DBG_STATE, ("dhcp_handle_offer(): server 0x%08"X32_F"\n", dhcp->server_ip_addr.addr)); |
| 197 | /* remember offered address */ |
| 198 | ip_addr_set(&dhcp->offered_ip_addr, (struct ip_addr *)&dhcp->msg_in->yiaddr); |
| 199 | LWIP_DEBUGF(DHCP_DEBUG | DBG_STATE, ("dhcp_handle_offer(): offer for 0x%08"X32_F"\n", dhcp->offered_ip_addr.addr)); |
| 200 | |
| 201 | dhcp_select(netif); |
| 202 | } |
| 203 | } |
| 204 | |
| 205 | /** |
| 206 | * Select a DHCP server offer out of all offers. |
| 207 | * |
| 208 | * Simply select the first offer received. |
| 209 | * |
| 210 | * @param netif the netif under DHCP control |
| 211 | * @return lwIP specific error (see error.h) |
| 212 | */ |
| 213 | static err_t dhcp_select(struct netif *netif) |
| 214 | { |
| 215 | struct dhcp *dhcp = netif->dhcp; |
| 216 | err_t result; |
| 217 | u32_t msecs; |
| 218 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | 3, ("dhcp_select(netif=%p) %c%c%"U16_F"\n", (void*)netif, netif->name[0], netif->name[1], (u16_t)netif->num)); |
| 219 | |
| 220 | /* create and initialize the DHCP message header */ |
| 221 | result = dhcp_create_request(netif); |
| 222 | if (result == ERR_OK) |
| 223 | { |
| 224 | dhcp_option(dhcp, DHCP_OPTION_MESSAGE_TYPE, DHCP_OPTION_MESSAGE_TYPE_LEN); |
| 225 | dhcp_option_byte(dhcp, DHCP_REQUEST); |
| 226 | |
| 227 | dhcp_option(dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN); |
| 228 | dhcp_option_short(dhcp, 576); |
| 229 | |
| 230 | /* MUST request the offered IP address */ |
| 231 | dhcp_option(dhcp, DHCP_OPTION_REQUESTED_IP, 4); |
| 232 | dhcp_option_long(dhcp, ntohl(dhcp->offered_ip_addr.addr)); |
| 233 | |
| 234 | dhcp_option(dhcp, DHCP_OPTION_SERVER_ID, 4); |
| 235 | dhcp_option_long(dhcp, ntohl(dhcp->server_ip_addr.addr)); |
| 236 | |
| 237 | dhcp_option(dhcp, DHCP_OPTION_PARAMETER_REQUEST_LIST, 4/*num options*/); |
| 238 | dhcp_option_byte(dhcp, DHCP_OPTION_SUBNET_MASK); |
| 239 | dhcp_option_byte(dhcp, DHCP_OPTION_ROUTER); |
| 240 | dhcp_option_byte(dhcp, DHCP_OPTION_BROADCAST); |
| 241 | dhcp_option_byte(dhcp, DHCP_OPTION_DNS_SERVER); |
| 242 | |
| 243 | dhcp_option_trailer(dhcp); |
| 244 | /* shrink the pbuf to the actual content length */ |
| 245 | pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len); |
| 246 | |
| 247 | /* TODO: we really should bind to a specific local interface here |
| 248 | but we cannot specify an unconfigured netif as it is addressless */ |
| 249 | udp_bind(dhcp->pcb, IP_ADDR_ANY, DHCP_CLIENT_PORT); |
| 250 | /* send broadcast to any DHCP server */ |
| 251 | udp_connect(dhcp->pcb, IP_ADDR_BROADCAST, DHCP_SERVER_PORT); |
| 252 | udp_send(dhcp->pcb, dhcp->p_out); |
| 253 | /* reconnect to any (or to server here?!) */ |
| 254 | udp_connect(dhcp->pcb, IP_ADDR_ANY, DHCP_SERVER_PORT); |
| 255 | dhcp_delete_request(netif); |
| 256 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | DBG_STATE, ("dhcp_select: REQUESTING\n")); |
| 257 | dhcp_set_state(dhcp, DHCP_REQUESTING); |
| 258 | } else { |
| 259 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | 2, ("dhcp_select: could not allocate DHCP request\n")); |
| 260 | } |
| 261 | dhcp->tries++; |
| 262 | msecs = dhcp->tries < 4 ? dhcp->tries * 1000 : 4 * 1000; |
| 263 | dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS; |
| 264 | LWIP_DEBUGF(DHCP_DEBUG | DBG_STATE, ("dhcp_select(): set request timeout %"U32_F" msecs\n", msecs)); |
| 265 | return result; |
| 266 | } |
| 267 | |
| 268 | /** |
| 269 | * The DHCP timer that checks for lease renewal/rebind timeouts. |
| 270 | * |
| 271 | */ |
| 272 | void dhcp_coarse_tmr() |
| 273 | { |
| 274 | struct netif *netif = netif_list; |
| 275 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE, ("dhcp_coarse_tmr()\n")); |
| 276 | /* iterate through all network interfaces */ |
| 277 | while (netif != NULL) { |
| 278 | /* only act on DHCP configured interfaces */ |
| 279 | if (netif->dhcp != NULL) { |
| 280 | /* timer is active (non zero), and triggers (zeroes) now? */ |
| 281 | if (netif->dhcp->t2_timeout-- == 1) { |
| 282 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | DBG_STATE, ("dhcp_coarse_tmr(): t2 timeout\n")); |
| 283 | /* this clients' rebind timeout triggered */ |
| 284 | dhcp_t2_timeout(netif); |
| 285 | /* timer is active (non zero), and triggers (zeroes) now */ |
| 286 | } else if (netif->dhcp->t1_timeout-- == 1) { |
| 287 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | DBG_STATE, ("dhcp_coarse_tmr(): t1 timeout\n")); |
| 288 | /* this clients' renewal timeout triggered */ |
| 289 | dhcp_t1_timeout(netif); |
| 290 | } |
| 291 | } |
| 292 | /* proceed to next netif */ |
| 293 | netif = netif->next; |
| 294 | } |
| 295 | } |
| 296 | |
| 297 | /** |
| 298 | * DHCP transaction timeout handling |
| 299 | * |
| 300 | * A DHCP server is expected to respond within a short period of time. |
| 301 | * This timer checks whether an outstanding DHCP request is timed out. |
| 302 | * |
| 303 | */ |
| 304 | void dhcp_fine_tmr() |
| 305 | { |
| 306 | struct netif *netif = netif_list; |
| 307 | /* loop through netif's */ |
| 308 | while (netif != NULL) { |
| 309 | /* only act on DHCP configured interfaces */ |
| 310 | if (netif->dhcp != NULL) { |
| 311 | /* timer is active (non zero), and is about to trigger now */ |
| 312 | if (netif->dhcp->request_timeout-- == 1) { |
| 313 | /* { netif->dhcp->request_timeout == 0 } */ |
| 314 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | DBG_STATE, ("dhcp_fine_tmr(): request timeout\n")); |
| 315 | /* this clients' request timeout triggered */ |
| 316 | dhcp_timeout(netif); |
| 317 | } |
| 318 | } |
| 319 | /* proceed to next network interface */ |
| 320 | netif = netif->next; |
| 321 | } |
| 322 | } |
| 323 | |
| 324 | /** |
| 325 | * A DHCP negotiation transaction, or ARP request, has timed out. |
| 326 | * |
| 327 | * The timer that was started with the DHCP or ARP request has |
| 328 | * timed out, indicating no response was received in time. |
| 329 | * |
| 330 | * @param netif the netif under DHCP control |
| 331 | * |
| 332 | */ |
| 333 | static void dhcp_timeout(struct netif *netif) |
| 334 | { |
| 335 | struct dhcp *dhcp = netif->dhcp; |
| 336 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | 3, ("dhcp_timeout()\n")); |
| 337 | /* back-off period has passed, or server selection timed out */ |
| 338 | if ((dhcp->state == DHCP_BACKING_OFF) || (dhcp->state == DHCP_SELECTING)) { |
| 339 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE, ("dhcp_timeout(): restarting discovery\n")); |
| 340 | dhcp_discover(netif); |
| 341 | /* receiving the requested lease timed out */ |
| 342 | } else if (dhcp->state == DHCP_REQUESTING) { |
| 343 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | DBG_STATE, ("dhcp_timeout(): REQUESTING, DHCP request timed out\n")); |
| 344 | if (dhcp->tries <= 5) { |
| 345 | dhcp_select(netif); |
| 346 | } else { |
| 347 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | DBG_STATE, ("dhcp_timeout(): REQUESTING, releasing, restarting\n")); |
| 348 | dhcp_release(netif); |
| 349 | dhcp_discover(netif); |
| 350 | } |
| 351 | /* received no ARP reply for the offered address (which is good) */ |
| 352 | } else if (dhcp->state == DHCP_CHECKING) { |
| 353 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | DBG_STATE, ("dhcp_timeout(): CHECKING, ARP request timed out\n")); |
| 354 | if (dhcp->tries <= 1) { |
| 355 | dhcp_check(netif); |
| 356 | /* no ARP replies on the offered address, |
| 357 | looks like the IP address is indeed free */ |
| 358 | } else { |
| 359 | /* bind the interface to the offered address */ |
| 360 | dhcp_bind(netif); |
| 361 | } |
| 362 | } |
| 363 | /* did not get response to renew request? */ |
| 364 | else if (dhcp->state == DHCP_RENEWING) { |
| 365 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | DBG_STATE, ("dhcp_timeout(): RENEWING, DHCP request timed out\n")); |
| 366 | /* just retry renewal */ |
| 367 | /* note that the rebind timer will eventually time-out if renew does not work */ |
| 368 | dhcp_renew(netif); |
| 369 | /* did not get response to rebind request? */ |
| 370 | } else if (dhcp->state == DHCP_REBINDING) { |
| 371 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | DBG_STATE, ("dhcp_timeout(): REBINDING, DHCP request timed out\n")); |
| 372 | if (dhcp->tries <= 8) { |
| 373 | dhcp_rebind(netif); |
| 374 | } else { |
| 375 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | DBG_STATE, ("dhcp_timeout(): RELEASING, DISCOVERING\n")); |
| 376 | dhcp_release(netif); |
| 377 | dhcp_discover(netif); |
| 378 | } |
| 379 | } |
| 380 | } |
| 381 | |
| 382 | /** |
| 383 | * The renewal period has timed out. |
| 384 | * |
| 385 | * @param netif the netif under DHCP control |
| 386 | */ |
| 387 | static void dhcp_t1_timeout(struct netif *netif) |
| 388 | { |
| 389 | struct dhcp *dhcp = netif->dhcp; |
| 390 | LWIP_DEBUGF(DHCP_DEBUG | DBG_STATE, ("dhcp_t1_timeout()\n")); |
| 391 | if ((dhcp->state == DHCP_REQUESTING) || (dhcp->state == DHCP_BOUND) || (dhcp->state == DHCP_RENEWING)) { |
| 392 | /* just retry to renew - note that the rebind timer (t2) will |
| 393 | * eventually time-out if renew tries fail. */ |
| 394 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | DBG_STATE, ("dhcp_t1_timeout(): must renew\n")); |
| 395 | dhcp_renew(netif); |
| 396 | } |
| 397 | } |
| 398 | |
| 399 | /** |
| 400 | * The rebind period has timed out. |
| 401 | * |
| 402 | */ |
| 403 | static void dhcp_t2_timeout(struct netif *netif) |
| 404 | { |
| 405 | struct dhcp *dhcp = netif->dhcp; |
| 406 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | DBG_STATE, ("dhcp_t2_timeout()\n")); |
| 407 | if ((dhcp->state == DHCP_REQUESTING) || (dhcp->state == DHCP_BOUND) || (dhcp->state == DHCP_RENEWING)) { |
| 408 | /* just retry to rebind */ |
| 409 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | DBG_STATE, ("dhcp_t2_timeout(): must rebind\n")); |
| 410 | dhcp_rebind(netif); |
| 411 | } |
| 412 | } |
| 413 | |
| 414 | /** |
| 415 | * |
| 416 | * @param netif the netif under DHCP control |
| 417 | */ |
| 418 | static void dhcp_handle_ack(struct netif *netif) |
| 419 | { |
| 420 | struct dhcp *dhcp = netif->dhcp; |
| 421 | u8_t *option_ptr; |
| 422 | /* clear options we might not get from the ACK */ |
| 423 | dhcp->offered_sn_mask.addr = 0; |
| 424 | dhcp->offered_gw_addr.addr = 0; |
| 425 | dhcp->offered_bc_addr.addr = 0; |
| 426 | |
| 427 | /* lease time given? */ |
| 428 | option_ptr = dhcp_get_option_ptr(dhcp, DHCP_OPTION_LEASE_TIME); |
| 429 | if (option_ptr != NULL) { |
| 430 | /* remember offered lease time */ |
| 431 | dhcp->offered_t0_lease = dhcp_get_option_long(option_ptr + 2); |
| 432 | } |
| 433 | /* renewal period given? */ |
| 434 | option_ptr = dhcp_get_option_ptr(dhcp, DHCP_OPTION_T1); |
| 435 | if (option_ptr != NULL) { |
| 436 | /* remember given renewal period */ |
| 437 | dhcp->offered_t1_renew = dhcp_get_option_long(option_ptr + 2); |
| 438 | } else { |
| 439 | /* calculate safe periods for renewal */ |
| 440 | dhcp->offered_t1_renew = dhcp->offered_t0_lease / 2; |
| 441 | } |
| 442 | |
| 443 | /* renewal period given? */ |
| 444 | option_ptr = dhcp_get_option_ptr(dhcp, DHCP_OPTION_T2); |
| 445 | if (option_ptr != NULL) { |
| 446 | /* remember given rebind period */ |
| 447 | dhcp->offered_t2_rebind = dhcp_get_option_long(option_ptr + 2); |
| 448 | } else { |
| 449 | /* calculate safe periods for rebinding */ |
| 450 | dhcp->offered_t2_rebind = dhcp->offered_t0_lease; |
| 451 | } |
| 452 | |
| 453 | /* (y)our internet address */ |
| 454 | ip_addr_set(&dhcp->offered_ip_addr, &dhcp->msg_in->yiaddr); |
| 455 | |
| 456 | /** |
| 457 | * Patch #1308 |
| 458 | * TODO: we must check if the file field is not overloaded by DHCP options! |
| 459 | */ |
| 460 | #if 0 |
| 461 | /* boot server address */ |
| 462 | ip_addr_set(&dhcp->offered_si_addr, &dhcp->msg_in->siaddr); |
| 463 | /* boot file name */ |
| 464 | if (dhcp->msg_in->file[0]) { |
| 465 | dhcp->boot_file_name = mem_malloc(strlen(dhcp->msg_in->file) + 1); |
| 466 | strcpy(dhcp->boot_file_name, dhcp->msg_in->file); |
| 467 | } |
| 468 | #endif |
| 469 | |
| 470 | /* subnet mask */ |
| 471 | option_ptr = dhcp_get_option_ptr(dhcp, DHCP_OPTION_SUBNET_MASK); |
| 472 | /* subnet mask given? */ |
| 473 | if (option_ptr != NULL) { |
| 474 | dhcp->offered_sn_mask.addr = htonl(dhcp_get_option_long(&option_ptr[2])); |
| 475 | } |
| 476 | |
| 477 | /* gateway router */ |
| 478 | option_ptr = dhcp_get_option_ptr(dhcp, DHCP_OPTION_ROUTER); |
| 479 | if (option_ptr != NULL) { |
| 480 | dhcp->offered_gw_addr.addr = htonl(dhcp_get_option_long(&option_ptr[2])); |
| 481 | } |
| 482 | |
| 483 | /* broadcast address */ |
| 484 | option_ptr = dhcp_get_option_ptr(dhcp, DHCP_OPTION_BROADCAST); |
| 485 | if (option_ptr != NULL) { |
| 486 | dhcp->offered_bc_addr.addr = htonl(dhcp_get_option_long(&option_ptr[2])); |
| 487 | } |
| 488 | |
| 489 | /* DNS servers */ |
| 490 | option_ptr = dhcp_get_option_ptr(dhcp, DHCP_OPTION_DNS_SERVER); |
| 491 | if (option_ptr != NULL) { |
| 492 | u8_t n; |
| 493 | dhcp->dns_count = dhcp_get_option_byte(&option_ptr[1]); |
| 494 | /* limit to at most DHCP_MAX_DNS DNS servers */ |
| 495 | if (dhcp->dns_count > DHCP_MAX_DNS) dhcp->dns_count = DHCP_MAX_DNS; |
| 496 | for (n = 0; n < dhcp->dns_count; n++) |
| 497 | { |
| 498 | dhcp->offered_dns_addr[n].addr = htonl(dhcp_get_option_long(&option_ptr[2+(n<<2)])); |
| 499 | } |
| 500 | } |
| 501 | } |
| 502 | |
| 503 | /** |
| 504 | * Start DHCP negotiation for a network interface. |
| 505 | * |
| 506 | * If no DHCP client instance was attached to this interface, |
| 507 | * a new client is created first. If a DHCP client instance |
| 508 | * was already present, it restarts negotiation. |
| 509 | * |
| 510 | * @param netif The lwIP network interface |
| 511 | * @return lwIP error code |
| 512 | * - ERR_OK - No error |
| 513 | * - ERR_MEM - Out of memory |
| 514 | * |
| 515 | */ |
| 516 | err_t dhcp_start(struct netif *netif) |
| 517 | { |
| 518 | struct dhcp *dhcp = netif->dhcp; |
| 519 | err_t result = ERR_OK; |
| 520 | |
| 521 | LWIP_ASSERT("netif != NULL", netif != NULL); |
| 522 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | DBG_STATE, ("dhcp_start(netif=%p) %c%c%"U16_F"\n", (void*)netif, netif->name[0], netif->name[1], (u16_t)netif->num)); |
| 523 | netif->flags &= ~NETIF_FLAG_DHCP; |
| 524 | |
| 525 | /* no DHCP client attached yet? */ |
| 526 | if (dhcp == NULL) { |
| 527 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE, ("dhcp_start(): starting new DHCP client\n")); |
| 528 | dhcp = mem_malloc(sizeof(struct dhcp)); |
| 529 | if (dhcp == NULL) { |
| 530 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE, ("dhcp_start(): could not allocate dhcp\n")); |
| 531 | return ERR_MEM; |
| 532 | } |
| 533 | /* store this dhcp client in the netif */ |
| 534 | netif->dhcp = dhcp; |
| 535 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE, ("dhcp_start(): allocated dhcp")); |
| 536 | /* already has DHCP client attached */ |
| 537 | } else { |
| 538 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | DBG_STATE | 3, ("dhcp_start(): restarting DHCP configuration\n")); |
| 539 | } |
| 540 | |
| 541 | /* clear data structure */ |
| 542 | memset(dhcp, 0, sizeof(struct dhcp)); |
| 543 | /* allocate UDP PCB */ |
| 544 | dhcp->pcb = udp_new(); |
| 545 | if (dhcp->pcb == NULL) { |
| 546 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE, ("dhcp_start(): could not obtain pcb\n")); |
| 547 | mem_free((void *)dhcp); |
| 548 | netif->dhcp = dhcp = NULL; |
| 549 | return ERR_MEM; |
| 550 | } |
| 551 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE, ("dhcp_start(): starting DHCP configuration\n")); |
| 552 | /* (re)start the DHCP negotiation */ |
| 553 | result = dhcp_discover(netif); |
| 554 | if (result != ERR_OK) { |
| 555 | /* free resources allocated above */ |
| 556 | dhcp_stop(netif); |
| 557 | return ERR_MEM; |
| 558 | } |
| 559 | netif->flags |= NETIF_FLAG_DHCP; |
| 560 | return result; |
| 561 | } |
| 562 | |
| 563 | /** |
| 564 | * Inform a DHCP server of our manual configuration. |
| 565 | * |
| 566 | * This informs DHCP servers of our fixed IP address configuration |
| 567 | * by sending an INFORM message. It does not involve DHCP address |
| 568 | * configuration, it is just here to be nice to the network. |
| 569 | * |
| 570 | * @param netif The lwIP network interface |
| 571 | * |
| 572 | */ |
| 573 | void dhcp_inform(struct netif *netif) |
| 574 | { |
| 575 | struct dhcp *dhcp; |
| 576 | err_t result = ERR_OK; |
| 577 | dhcp = mem_malloc(sizeof(struct dhcp)); |
| 578 | if (dhcp == NULL) { |
| 579 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | 2, ("dhcp_inform(): could not allocate dhcp\n")); |
| 580 | return; |
| 581 | } |
| 582 | netif->dhcp = dhcp; |
| 583 | memset(dhcp, 0, sizeof(struct dhcp)); |
| 584 | |
| 585 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE, ("dhcp_inform(): allocated dhcp\n")); |
| 586 | dhcp->pcb = udp_new(); |
| 587 | if (dhcp->pcb == NULL) { |
| 588 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | 2, ("dhcp_inform(): could not obtain pcb")); |
| 589 | mem_free((void *)dhcp); |
| 590 | return; |
| 591 | } |
| 592 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE, ("dhcp_inform(): created new udp pcb\n")); |
| 593 | /* create and initialize the DHCP message header */ |
| 594 | result = dhcp_create_request(netif); |
| 595 | if (result == ERR_OK) { |
| 596 | |
| 597 | dhcp_option(dhcp, DHCP_OPTION_MESSAGE_TYPE, DHCP_OPTION_MESSAGE_TYPE_LEN); |
| 598 | dhcp_option_byte(dhcp, DHCP_INFORM); |
| 599 | |
| 600 | dhcp_option(dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN); |
| 601 | /* TODO: use netif->mtu ?! */ |
| 602 | dhcp_option_short(dhcp, 576); |
| 603 | |
| 604 | dhcp_option_trailer(dhcp); |
| 605 | |
| 606 | pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len); |
| 607 | |
| 608 | udp_bind(dhcp->pcb, IP_ADDR_ANY, DHCP_CLIENT_PORT); |
| 609 | udp_connect(dhcp->pcb, IP_ADDR_BROADCAST, DHCP_SERVER_PORT); |
| 610 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | DBG_STATE, ("dhcp_inform: INFORMING\n")); |
| 611 | udp_send(dhcp->pcb, dhcp->p_out); |
| 612 | udp_connect(dhcp->pcb, IP_ADDR_ANY, DHCP_SERVER_PORT); |
| 613 | dhcp_delete_request(netif); |
| 614 | } else { |
| 615 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | 2, ("dhcp_inform: could not allocate DHCP request\n")); |
| 616 | } |
| 617 | |
| 618 | if (dhcp != NULL) |
| 619 | { |
| 620 | if (dhcp->pcb != NULL) udp_remove(dhcp->pcb); |
| 621 | dhcp->pcb = NULL; |
| 622 | mem_free((void *)dhcp); |
| 623 | netif->dhcp = NULL; |
| 624 | } |
| 625 | } |
| 626 | |
| 627 | #if DHCP_DOES_ARP_CHECK |
| 628 | /** |
| 629 | * Match an ARP reply with the offered IP address. |
| 630 | * |
| 631 | * @param addr The IP address we received a reply from |
| 632 | * |
| 633 | */ |
| 634 | void dhcp_arp_reply(struct netif *netif, struct ip_addr *addr) |
| 635 | { |
| 636 | LWIP_ASSERT("netif != NULL", netif != NULL); |
| 637 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | 3, ("dhcp_arp_reply()\n")); |
| 638 | /* is a DHCP client doing an ARP check? */ |
| 639 | if ((netif->dhcp != NULL) && (netif->dhcp->state == DHCP_CHECKING)) { |
| 640 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | DBG_STATE, ("dhcp_arp_reply(): CHECKING, arp reply for 0x%08"X32_F"\n", addr->addr)); |
| 641 | /* did a host respond with the address we |
| 642 | were offered by the DHCP server? */ |
| 643 | if (ip_addr_cmp(addr, &netif->dhcp->offered_ip_addr)) { |
| 644 | /* we will not accept the offered address */ |
| 645 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | DBG_STATE | 1, ("dhcp_arp_reply(): arp reply matched with offered address, declining\n")); |
| 646 | dhcp_decline(netif); |
| 647 | } |
| 648 | } |
| 649 | } |
| 650 | |
| 651 | /** |
| 652 | * Decline an offered lease. |
| 653 | * |
| 654 | * Tell the DHCP server we do not accept the offered address. |
| 655 | * One reason to decline the lease is when we find out the address |
| 656 | * is already in use by another host (through ARP). |
| 657 | */ |
| 658 | static err_t dhcp_decline(struct netif *netif) |
| 659 | { |
| 660 | struct dhcp *dhcp = netif->dhcp; |
| 661 | err_t result = ERR_OK; |
| 662 | u16_t msecs; |
| 663 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | 3, ("dhcp_decline()\n")); |
| 664 | dhcp_set_state(dhcp, DHCP_BACKING_OFF); |
| 665 | /* create and initialize the DHCP message header */ |
| 666 | result = dhcp_create_request(netif); |
| 667 | if (result == ERR_OK) |
| 668 | { |
| 669 | dhcp_option(dhcp, DHCP_OPTION_MESSAGE_TYPE, DHCP_OPTION_MESSAGE_TYPE_LEN); |
| 670 | dhcp_option_byte(dhcp, DHCP_DECLINE); |
| 671 | |
| 672 | dhcp_option(dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN); |
| 673 | dhcp_option_short(dhcp, 576); |
| 674 | |
| 675 | dhcp_option(dhcp, DHCP_OPTION_REQUESTED_IP, 4); |
| 676 | dhcp_option_long(dhcp, ntohl(dhcp->offered_ip_addr.addr)); |
| 677 | |
| 678 | dhcp_option_trailer(dhcp); |
| 679 | /* resize pbuf to reflect true size of options */ |
| 680 | pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len); |
| 681 | |
| 682 | udp_bind(dhcp->pcb, IP_ADDR_ANY, DHCP_CLIENT_PORT); |
| 683 | /* @todo: should we really connect here? we are performing sendto() */ |
| 684 | udp_connect(dhcp->pcb, IP_ADDR_ANY, DHCP_SERVER_PORT); |
| 685 | /* per section 4.4.4, broadcast DECLINE messages */ |
| 686 | udp_sendto(dhcp->pcb, dhcp->p_out, IP_ADDR_BROADCAST, DHCP_SERVER_PORT); |
| 687 | dhcp_delete_request(netif); |
| 688 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | DBG_STATE, ("dhcp_decline: BACKING OFF\n")); |
| 689 | } else { |
| 690 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | 2, ("dhcp_decline: could not allocate DHCP request\n")); |
| 691 | } |
| 692 | dhcp->tries++; |
| 693 | msecs = 10*1000; |
| 694 | dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS; |
| 695 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE, ("dhcp_decline(): set request timeout %"U16_F" msecs\n", msecs)); |
| 696 | return result; |
| 697 | } |
| 698 | #endif |
| 699 | |
| 700 | |
| 701 | /** |
| 702 | * Start the DHCP process, discover a DHCP server. |
| 703 | * |
| 704 | */ |
| 705 | static err_t dhcp_discover(struct netif *netif) |
| 706 | { |
| 707 | struct dhcp *dhcp = netif->dhcp; |
| 708 | err_t result = ERR_OK; |
| 709 | u16_t msecs; |
| 710 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | 3, ("dhcp_discover()\n")); |
| 711 | ip_addr_set(&dhcp->offered_ip_addr, IP_ADDR_ANY); |
| 712 | /* create and initialize the DHCP message header */ |
| 713 | result = dhcp_create_request(netif); |
| 714 | if (result == ERR_OK) |
| 715 | { |
| 716 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE, ("dhcp_discover: making request\n")); |
| 717 | dhcp_option(dhcp, DHCP_OPTION_MESSAGE_TYPE, DHCP_OPTION_MESSAGE_TYPE_LEN); |
| 718 | dhcp_option_byte(dhcp, DHCP_DISCOVER); |
| 719 | |
| 720 | dhcp_option(dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN); |
| 721 | dhcp_option_short(dhcp, 576); |
| 722 | |
| 723 | dhcp_option(dhcp, DHCP_OPTION_PARAMETER_REQUEST_LIST, 4/*num options*/); |
| 724 | dhcp_option_byte(dhcp, DHCP_OPTION_SUBNET_MASK); |
| 725 | dhcp_option_byte(dhcp, DHCP_OPTION_ROUTER); |
| 726 | dhcp_option_byte(dhcp, DHCP_OPTION_BROADCAST); |
| 727 | dhcp_option_byte(dhcp, DHCP_OPTION_DNS_SERVER); |
| 728 | |
| 729 | dhcp_option_trailer(dhcp); |
| 730 | |
| 731 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE, ("dhcp_discover: realloc()ing\n")); |
| 732 | pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len); |
| 733 | |
| 734 | /* set receive callback function with netif as user data */ |
| 735 | udp_recv(dhcp->pcb, dhcp_recv, netif); |
| 736 | udp_bind(dhcp->pcb, IP_ADDR_ANY, DHCP_CLIENT_PORT); |
| 737 | udp_connect(dhcp->pcb, IP_ADDR_ANY, DHCP_SERVER_PORT); |
| 738 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE, ("dhcp_discover: sendto(DISCOVER, IP_ADDR_BROADCAST, DHCP_SERVER_PORT)\n")); |
| 739 | udp_sendto(dhcp->pcb, dhcp->p_out, IP_ADDR_BROADCAST, DHCP_SERVER_PORT); |
| 740 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE, ("dhcp_discover: deleting()ing\n")); |
| 741 | dhcp_delete_request(netif); |
| 742 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | DBG_STATE, ("dhcp_discover: SELECTING\n")); |
| 743 | dhcp_set_state(dhcp, DHCP_SELECTING); |
| 744 | } else { |
| 745 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | 2, ("dhcp_discover: could not allocate DHCP request\n")); |
| 746 | } |
| 747 | dhcp->tries++; |
| 748 | msecs = dhcp->tries < 4 ? (dhcp->tries + 1) * 1000 : 10 * 1000; |
| 749 | dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS; |
| 750 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | DBG_STATE, ("dhcp_discover(): set request timeout %"U16_F" msecs\n", msecs)); |
| 751 | return result; |
| 752 | } |
| 753 | |
| 754 | |
| 755 | /** |
| 756 | * Bind the interface to the offered IP address. |
| 757 | * |
| 758 | * @param netif network interface to bind to the offered address |
| 759 | */ |
| 760 | static void dhcp_bind(struct netif *netif) |
| 761 | { |
| 762 | struct dhcp *dhcp = netif->dhcp; |
| 763 | struct ip_addr sn_mask, gw_addr; |
| 764 | LWIP_ASSERT("dhcp_bind: netif != NULL", netif != NULL); |
| 765 | LWIP_ASSERT("dhcp_bind: dhcp != NULL", dhcp != NULL); |
| 766 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | 3, ("dhcp_bind(netif=%p) %c%c%"U16_F"\n", (void*)netif, netif->name[0], netif->name[1], (u16_t)netif->num)); |
| 767 | |
| 768 | /* temporary DHCP lease? */ |
| 769 | if (dhcp->offered_t1_renew != 0xffffffffUL) { |
| 770 | /* set renewal period timer */ |
| 771 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE, ("dhcp_bind(): t1 renewal timer %"U32_F" secs\n", dhcp->offered_t1_renew)); |
| 772 | dhcp->t1_timeout = (dhcp->offered_t1_renew + DHCP_COARSE_TIMER_SECS / 2) / DHCP_COARSE_TIMER_SECS; |
| 773 | if (dhcp->t1_timeout == 0) dhcp->t1_timeout = 1; |
| 774 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | DBG_STATE, ("dhcp_bind(): set request timeout %"U32_F" msecs\n", dhcp->offered_t1_renew*1000)); |
| 775 | } |
| 776 | /* set renewal period timer */ |
| 777 | if (dhcp->offered_t2_rebind != 0xffffffffUL) { |
| 778 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE, ("dhcp_bind(): t2 rebind timer %"U32_F" secs\n", dhcp->offered_t2_rebind)); |
| 779 | dhcp->t2_timeout = (dhcp->offered_t2_rebind + DHCP_COARSE_TIMER_SECS / 2) / DHCP_COARSE_TIMER_SECS; |
| 780 | if (dhcp->t2_timeout == 0) dhcp->t2_timeout = 1; |
| 781 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | DBG_STATE, ("dhcp_bind(): set request timeout %"U32_F" msecs\n", dhcp->offered_t2_rebind*1000)); |
| 782 | } |
| 783 | /* copy offered network mask */ |
| 784 | ip_addr_set(&sn_mask, &dhcp->offered_sn_mask); |
| 785 | |
| 786 | /* subnet mask not given? */ |
| 787 | /* TODO: this is not a valid check. what if the network mask is 0? */ |
| 788 | if (sn_mask.addr == 0) { |
| 789 | /* choose a safe subnet mask given the network class */ |
| 790 | u8_t first_octet = ip4_addr1(&sn_mask); |
| 791 | if (first_octet <= 127) sn_mask.addr = htonl(0xff000000); |
| 792 | else if (first_octet >= 192) sn_mask.addr = htonl(0xffffff00); |
| 793 | else sn_mask.addr = htonl(0xffff0000); |
| 794 | } |
| 795 | |
| 796 | ip_addr_set(&gw_addr, &dhcp->offered_gw_addr); |
| 797 | /* gateway address not given? */ |
| 798 | if (gw_addr.addr == 0) { |
| 799 | /* copy network address */ |
| 800 | gw_addr.addr = (dhcp->offered_ip_addr.addr & sn_mask.addr); |
| 801 | /* use first host address on network as gateway */ |
| 802 | gw_addr.addr |= htonl(0x00000001); |
| 803 | } |
| 804 | |
| 805 | LWIP_DEBUGF(DHCP_DEBUG | DBG_STATE, ("dhcp_bind(): IP: 0x%08"X32_F"\n", dhcp->offered_ip_addr.addr)); |
| 806 | netif_set_ipaddr(netif, &dhcp->offered_ip_addr); |
| 807 | LWIP_DEBUGF(DHCP_DEBUG | DBG_STATE, ("dhcp_bind(): SN: 0x%08"X32_F"\n", sn_mask.addr)); |
| 808 | netif_set_netmask(netif, &sn_mask); |
| 809 | LWIP_DEBUGF(DHCP_DEBUG | DBG_STATE, ("dhcp_bind(): GW: 0x%08"X32_F"\n", gw_addr.addr)); |
| 810 | netif_set_gw(netif, &gw_addr); |
| 811 | /* bring the interface up */ |
| 812 | netif_set_up(netif); |
| 813 | /* netif is now bound to DHCP leased address */ |
| 814 | dhcp_set_state(dhcp, DHCP_BOUND); |
| 815 | } |
| 816 | |
| 817 | /** |
| 818 | * Renew an existing DHCP lease at the involved DHCP server. |
| 819 | * |
| 820 | * @param netif network interface which must renew its lease |
| 821 | */ |
| 822 | err_t dhcp_renew(struct netif *netif) |
| 823 | { |
| 824 | struct dhcp *dhcp = netif->dhcp; |
| 825 | err_t result; |
| 826 | u16_t msecs; |
| 827 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | 3, ("dhcp_renew()\n")); |
| 828 | dhcp_set_state(dhcp, DHCP_RENEWING); |
| 829 | |
| 830 | /* create and initialize the DHCP message header */ |
| 831 | result = dhcp_create_request(netif); |
| 832 | if (result == ERR_OK) { |
| 833 | |
| 834 | dhcp_option(dhcp, DHCP_OPTION_MESSAGE_TYPE, DHCP_OPTION_MESSAGE_TYPE_LEN); |
| 835 | dhcp_option_byte(dhcp, DHCP_REQUEST); |
| 836 | |
| 837 | dhcp_option(dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN); |
| 838 | /* TODO: use netif->mtu in some way */ |
| 839 | dhcp_option_short(dhcp, 576); |
| 840 | |
| 841 | #if 0 |
| 842 | dhcp_option(dhcp, DHCP_OPTION_REQUESTED_IP, 4); |
| 843 | dhcp_option_long(dhcp, ntohl(dhcp->offered_ip_addr.addr)); |
| 844 | #endif |
| 845 | |
| 846 | #if 0 |
| 847 | dhcp_option(dhcp, DHCP_OPTION_SERVER_ID, 4); |
| 848 | dhcp_option_long(dhcp, ntohl(dhcp->server_ip_addr.addr)); |
| 849 | #endif |
| 850 | /* append DHCP message trailer */ |
| 851 | dhcp_option_trailer(dhcp); |
| 852 | |
| 853 | pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len); |
| 854 | |
| 855 | udp_bind(dhcp->pcb, IP_ADDR_ANY, DHCP_CLIENT_PORT); |
| 856 | udp_connect(dhcp->pcb, &dhcp->server_ip_addr, DHCP_SERVER_PORT); |
| 857 | udp_send(dhcp->pcb, dhcp->p_out); |
| 858 | dhcp_delete_request(netif); |
| 859 | |
| 860 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | DBG_STATE, ("dhcp_renew: RENEWING\n")); |
| 861 | } else { |
| 862 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | 2, ("dhcp_renew: could not allocate DHCP request\n")); |
| 863 | } |
| 864 | dhcp->tries++; |
| 865 | /* back-off on retries, but to a maximum of 20 seconds */ |
| 866 | msecs = dhcp->tries < 10 ? dhcp->tries * 2000 : 20 * 1000; |
| 867 | dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS; |
| 868 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | DBG_STATE, ("dhcp_renew(): set request timeout %"U16_F" msecs\n", msecs)); |
| 869 | return result; |
| 870 | } |
| 871 | |
| 872 | /** |
| 873 | * Rebind with a DHCP server for an existing DHCP lease. |
| 874 | * |
| 875 | * @param netif network interface which must rebind with a DHCP server |
| 876 | */ |
| 877 | static err_t dhcp_rebind(struct netif *netif) |
| 878 | { |
| 879 | struct dhcp *dhcp = netif->dhcp; |
| 880 | err_t result; |
| 881 | u16_t msecs; |
| 882 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | DBG_STATE, ("dhcp_rebind()\n")); |
| 883 | dhcp_set_state(dhcp, DHCP_REBINDING); |
| 884 | |
| 885 | /* create and initialize the DHCP message header */ |
| 886 | result = dhcp_create_request(netif); |
| 887 | if (result == ERR_OK) |
| 888 | { |
| 889 | |
| 890 | dhcp_option(dhcp, DHCP_OPTION_MESSAGE_TYPE, DHCP_OPTION_MESSAGE_TYPE_LEN); |
| 891 | dhcp_option_byte(dhcp, DHCP_REQUEST); |
| 892 | |
| 893 | dhcp_option(dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN); |
| 894 | dhcp_option_short(dhcp, 576); |
| 895 | |
| 896 | #if 0 |
| 897 | dhcp_option(dhcp, DHCP_OPTION_REQUESTED_IP, 4); |
| 898 | dhcp_option_long(dhcp, ntohl(dhcp->offered_ip_addr.addr)); |
| 899 | |
| 900 | dhcp_option(dhcp, DHCP_OPTION_SERVER_ID, 4); |
| 901 | dhcp_option_long(dhcp, ntohl(dhcp->server_ip_addr.addr)); |
| 902 | #endif |
| 903 | |
| 904 | dhcp_option_trailer(dhcp); |
| 905 | |
| 906 | pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len); |
| 907 | |
| 908 | /* set remote IP association to any DHCP server */ |
| 909 | udp_bind(dhcp->pcb, IP_ADDR_ANY, DHCP_CLIENT_PORT); |
| 910 | udp_connect(dhcp->pcb, IP_ADDR_ANY, DHCP_SERVER_PORT); |
| 911 | /* broadcast to server */ |
| 912 | udp_sendto(dhcp->pcb, dhcp->p_out, IP_ADDR_BROADCAST, DHCP_SERVER_PORT); |
| 913 | dhcp_delete_request(netif); |
| 914 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | DBG_STATE, ("dhcp_rebind: REBINDING\n")); |
| 915 | } else { |
| 916 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | 2, ("dhcp_rebind: could not allocate DHCP request\n")); |
| 917 | } |
| 918 | dhcp->tries++; |
| 919 | msecs = dhcp->tries < 10 ? dhcp->tries * 1000 : 10 * 1000; |
| 920 | dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS; |
| 921 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | DBG_STATE, ("dhcp_rebind(): set request timeout %"U16_F" msecs\n", msecs)); |
| 922 | return result; |
| 923 | } |
| 924 | |
| 925 | /** |
| 926 | * Release a DHCP lease. |
| 927 | * |
| 928 | * @param netif network interface which must release its lease |
| 929 | */ |
| 930 | err_t dhcp_release(struct netif *netif) |
| 931 | { |
| 932 | struct dhcp *dhcp = netif->dhcp; |
| 933 | err_t result; |
| 934 | u16_t msecs; |
| 935 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | 3, ("dhcp_release()\n")); |
| 936 | |
| 937 | /* idle DHCP client */ |
| 938 | dhcp_set_state(dhcp, DHCP_OFF); |
| 939 | /* clean old DHCP offer */ |
| 940 | dhcp->server_ip_addr.addr = 0; |
| 941 | dhcp->offered_ip_addr.addr = dhcp->offered_sn_mask.addr = 0; |
| 942 | dhcp->offered_gw_addr.addr = dhcp->offered_bc_addr.addr = 0; |
| 943 | dhcp->offered_t0_lease = dhcp->offered_t1_renew = dhcp->offered_t2_rebind = 0; |
| 944 | dhcp->dns_count = 0; |
| 945 | |
| 946 | /* create and initialize the DHCP message header */ |
| 947 | result = dhcp_create_request(netif); |
| 948 | if (result == ERR_OK) { |
| 949 | dhcp_option(dhcp, DHCP_OPTION_MESSAGE_TYPE, DHCP_OPTION_MESSAGE_TYPE_LEN); |
| 950 | dhcp_option_byte(dhcp, DHCP_RELEASE); |
| 951 | |
| 952 | dhcp_option_trailer(dhcp); |
| 953 | |
| 954 | pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len); |
| 955 | |
| 956 | udp_bind(dhcp->pcb, IP_ADDR_ANY, DHCP_CLIENT_PORT); |
| 957 | udp_connect(dhcp->pcb, &dhcp->server_ip_addr, DHCP_SERVER_PORT); |
| 958 | udp_send(dhcp->pcb, dhcp->p_out); |
| 959 | dhcp_delete_request(netif); |
| 960 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | DBG_STATE, ("dhcp_release: RELEASED, DHCP_OFF\n")); |
| 961 | } else { |
| 962 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | 2, ("dhcp_release: could not allocate DHCP request\n")); |
| 963 | } |
| 964 | dhcp->tries++; |
| 965 | msecs = dhcp->tries < 10 ? dhcp->tries * 1000 : 10 * 1000; |
| 966 | dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS; |
| 967 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | DBG_STATE, ("dhcp_release(): set request timeout %"U16_F" msecs\n", msecs)); |
| 968 | /* bring the interface down */ |
| 969 | netif_set_down(netif); |
| 970 | /* remove IP address from interface */ |
| 971 | netif_set_ipaddr(netif, IP_ADDR_ANY); |
| 972 | netif_set_gw(netif, IP_ADDR_ANY); |
| 973 | netif_set_netmask(netif, IP_ADDR_ANY); |
| 974 | |
| 975 | /* TODO: netif_down(netif); */ |
| 976 | return result; |
| 977 | } |
| 978 | /** |
| 979 | * Remove the DHCP client from the interface. |
| 980 | * |
| 981 | * @param netif The network interface to stop DHCP on |
| 982 | */ |
| 983 | void dhcp_stop(struct netif *netif) |
| 984 | { |
| 985 | struct dhcp *dhcp = netif->dhcp; |
| 986 | LWIP_ASSERT("dhcp_stop: netif != NULL", netif != NULL); |
| 987 | |
| 988 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | 3, ("dhcp_stop()\n")); |
| 989 | /* netif is DHCP configured? */ |
| 990 | if (dhcp != NULL) |
| 991 | { |
| 992 | if (dhcp->pcb != NULL) |
| 993 | { |
| 994 | udp_remove(dhcp->pcb); |
| 995 | dhcp->pcb = NULL; |
| 996 | } |
| 997 | if (dhcp->p != NULL) |
| 998 | { |
| 999 | pbuf_free(dhcp->p); |
| 1000 | dhcp->p = NULL; |
| 1001 | } |
| 1002 | /* free unfolded reply */ |
| 1003 | dhcp_free_reply(dhcp); |
| 1004 | mem_free((void *)dhcp); |
| 1005 | netif->dhcp = NULL; |
| 1006 | } |
| 1007 | } |
| 1008 | |
| 1009 | /* |
| 1010 | * Set the DHCP state of a DHCP client. |
| 1011 | * |
| 1012 | * If the state changed, reset the number of tries. |
| 1013 | * |
| 1014 | * TODO: we might also want to reset the timeout here? |
| 1015 | */ |
| 1016 | static void dhcp_set_state(struct dhcp *dhcp, u8_t new_state) |
| 1017 | { |
| 1018 | if (new_state != dhcp->state) |
| 1019 | { |
| 1020 | dhcp->state = new_state; |
| 1021 | dhcp->tries = 0; |
| 1022 | } |
| 1023 | } |
| 1024 | |
| 1025 | /* |
| 1026 | * Concatenate an option type and length field to the outgoing |
| 1027 | * DHCP message. |
| 1028 | * |
| 1029 | */ |
| 1030 | static void dhcp_option(struct dhcp *dhcp, u8_t option_type, u8_t option_len) |
| 1031 | { |
| 1032 | LWIP_ASSERT("dhcp_option_short: dhcp->options_out_len + 2 + option_len <= DHCP_OPTIONS_LEN", dhcp->options_out_len + 2 + option_len <= DHCP_OPTIONS_LEN); |
| 1033 | dhcp->msg_out->options[dhcp->options_out_len++] = option_type; |
| 1034 | dhcp->msg_out->options[dhcp->options_out_len++] = option_len; |
| 1035 | } |
| 1036 | /* |
| 1037 | * Concatenate a single byte to the outgoing DHCP message. |
| 1038 | * |
| 1039 | */ |
| 1040 | static void dhcp_option_byte(struct dhcp *dhcp, u8_t value) |
| 1041 | { |
| 1042 | LWIP_ASSERT("dhcp_option_short: dhcp->options_out_len < DHCP_OPTIONS_LEN", dhcp->options_out_len < DHCP_OPTIONS_LEN); |
| 1043 | dhcp->msg_out->options[dhcp->options_out_len++] = value; |
| 1044 | } |
| 1045 | static void dhcp_option_short(struct dhcp *dhcp, u16_t value) |
| 1046 | { |
| 1047 | LWIP_ASSERT("dhcp_option_short: dhcp->options_out_len + 2 <= DHCP_OPTIONS_LEN", dhcp->options_out_len + 2 <= DHCP_OPTIONS_LEN); |
| 1048 | dhcp->msg_out->options[dhcp->options_out_len++] = (value & 0xff00U) >> 8; |
| 1049 | dhcp->msg_out->options[dhcp->options_out_len++] = value & 0x00ffU; |
| 1050 | } |
| 1051 | static void dhcp_option_long(struct dhcp *dhcp, u32_t value) |
| 1052 | { |
| 1053 | LWIP_ASSERT("dhcp_option_long: dhcp->options_out_len + 4 <= DHCP_OPTIONS_LEN", dhcp->options_out_len + 4 <= DHCP_OPTIONS_LEN); |
| 1054 | dhcp->msg_out->options[dhcp->options_out_len++] = (value & 0xff000000UL) >> 24; |
| 1055 | dhcp->msg_out->options[dhcp->options_out_len++] = (value & 0x00ff0000UL) >> 16; |
| 1056 | dhcp->msg_out->options[dhcp->options_out_len++] = (value & 0x0000ff00UL) >> 8; |
| 1057 | dhcp->msg_out->options[dhcp->options_out_len++] = (value & 0x000000ffUL); |
| 1058 | } |
| 1059 | |
| 1060 | /** |
| 1061 | * Extract the DHCP message and the DHCP options. |
| 1062 | * |
| 1063 | * Extract the DHCP message and the DHCP options, each into a contiguous |
| 1064 | * piece of memory. As a DHCP message is variable sized by its options, |
| 1065 | * and also allows overriding some fields for options, the easy approach |
| 1066 | * is to first unfold the options into a conitguous piece of memory, and |
| 1067 | * use that further on. |
| 1068 | * |
| 1069 | */ |
| 1070 | static err_t dhcp_unfold_reply(struct dhcp *dhcp) |
| 1071 | { |
| 1072 | struct pbuf *p = dhcp->p; |
| 1073 | u8_t *ptr; |
| 1074 | u16_t i; |
| 1075 | u16_t j = 0; |
| 1076 | LWIP_ASSERT("dhcp->p != NULL", dhcp->p != NULL); |
| 1077 | /* free any left-overs from previous unfolds */ |
| 1078 | dhcp_free_reply(dhcp); |
| 1079 | /* options present? */ |
| 1080 | if (dhcp->p->tot_len > (sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN)) |
| 1081 | { |
| 1082 | dhcp->options_in_len = dhcp->p->tot_len - (sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN); |
| 1083 | dhcp->options_in = mem_malloc(dhcp->options_in_len); |
| 1084 | if (dhcp->options_in == NULL) |
| 1085 | { |
| 1086 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | 2, ("dhcp_unfold_reply(): could not allocate dhcp->options\n")); |
| 1087 | return ERR_MEM; |
| 1088 | } |
| 1089 | } |
| 1090 | dhcp->msg_in = mem_malloc(sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN); |
| 1091 | if (dhcp->msg_in == NULL) |
| 1092 | { |
| 1093 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | 2, ("dhcp_unfold_reply(): could not allocate dhcp->msg_in\n")); |
| 1094 | mem_free((void *)dhcp->options_in); |
| 1095 | dhcp->options_in = NULL; |
| 1096 | return ERR_MEM; |
| 1097 | } |
| 1098 | |
| 1099 | ptr = (u8_t *)dhcp->msg_in; |
| 1100 | /* proceed through struct dhcp_msg */ |
| 1101 | for (i = 0; i < sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN; i++) |
| 1102 | { |
| 1103 | *ptr++ = ((u8_t *)p->payload)[j++]; |
| 1104 | /* reached end of pbuf? */ |
| 1105 | if (j == p->len) |
| 1106 | { |
| 1107 | /* proceed to next pbuf in chain */ |
| 1108 | p = p->next; |
| 1109 | j = 0; |
| 1110 | } |
| 1111 | } |
| 1112 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE, ("dhcp_unfold_reply(): copied %"U16_F" bytes into dhcp->msg_in[]\n", i)); |
| 1113 | if (dhcp->options_in != NULL) { |
| 1114 | ptr = (u8_t *)dhcp->options_in; |
| 1115 | /* proceed through options */ |
| 1116 | for (i = 0; i < dhcp->options_in_len; i++) { |
| 1117 | *ptr++ = ((u8_t *)p->payload)[j++]; |
| 1118 | /* reached end of pbuf? */ |
| 1119 | if (j == p->len) { |
| 1120 | /* proceed to next pbuf in chain */ |
| 1121 | p = p->next; |
| 1122 | j = 0; |
| 1123 | } |
| 1124 | } |
| 1125 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE, ("dhcp_unfold_reply(): copied %"U16_F" bytes to dhcp->options_in[]\n", i)); |
| 1126 | } |
| 1127 | return ERR_OK; |
| 1128 | } |
| 1129 | |
| 1130 | /** |
| 1131 | * Free the incoming DHCP message including contiguous copy of |
| 1132 | * its DHCP options. |
| 1133 | * |
| 1134 | */ |
| 1135 | static void dhcp_free_reply(struct dhcp *dhcp) |
| 1136 | { |
| 1137 | if (dhcp->msg_in != NULL) { |
| 1138 | mem_free((void *)dhcp->msg_in); |
| 1139 | dhcp->msg_in = NULL; |
| 1140 | } |
| 1141 | if (dhcp->options_in) { |
| 1142 | mem_free((void *)dhcp->options_in); |
| 1143 | dhcp->options_in = NULL; |
| 1144 | dhcp->options_in_len = 0; |
| 1145 | } |
| 1146 | LWIP_DEBUGF(DHCP_DEBUG, ("dhcp_free_reply(): free'd\n")); |
| 1147 | } |
| 1148 | |
| 1149 | |
| 1150 | /** |
| 1151 | * If an incoming DHCP message is in response to us, then trigger the state machine |
| 1152 | */ |
| 1153 | static void dhcp_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, struct ip_addr *addr, u16_t port) |
| 1154 | { |
| 1155 | struct netif *netif = (struct netif *)arg; |
| 1156 | struct dhcp *dhcp = netif->dhcp; |
| 1157 | struct dhcp_msg *reply_msg = (struct dhcp_msg *)p->payload; |
| 1158 | u8_t *options_ptr; |
| 1159 | u8_t msg_type; |
| 1160 | u8_t i; |
| 1161 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | 3, ("dhcp_recv(pbuf = %p) from DHCP server %"U16_F".%"U16_F".%"U16_F".%"U16_F" port %"U16_F"\n", (void*)p, |
| 1162 | (u16_t)(ntohl(addr->addr) >> 24 & 0xff), (u16_t)(ntohl(addr->addr) >> 16 & 0xff), |
| 1163 | (u16_t)(ntohl(addr->addr) >> 8 & 0xff), (u16_t)(ntohl(addr->addr) & 0xff), port)); |
| 1164 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE, ("pbuf->len = %"U16_F"\n", p->len)); |
| 1165 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE, ("pbuf->tot_len = %"U16_F"\n", p->tot_len)); |
| 1166 | /* prevent warnings about unused arguments */ |
| 1167 | (void)pcb; (void)addr; (void)port; |
| 1168 | dhcp->p = p; |
| 1169 | /* TODO: check packet length before reading them */ |
| 1170 | if (reply_msg->op != DHCP_BOOTREPLY) { |
| 1171 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | 1, ("not a DHCP reply message, but type %"U16_F"\n", (u16_t)reply_msg->op)); |
| 1172 | pbuf_free(p); |
| 1173 | dhcp->p = NULL; |
| 1174 | return; |
| 1175 | } |
| 1176 | /* iterate through hardware address and match against DHCP message */ |
| 1177 | for (i = 0; i < netif->hwaddr_len; i++) { |
| 1178 | if (netif->hwaddr[i] != reply_msg->chaddr[i]) { |
| 1179 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | 2, ("netif->hwaddr[%"U16_F"]==%02"X16_F" != reply_msg->chaddr[%"U16_F"]==%02"X16_F"\n", |
| 1180 | (u16_t)i, (u16_t)netif->hwaddr[i], (u16_t)i, (u16_t)reply_msg->chaddr[i])); |
| 1181 | pbuf_free(p); |
| 1182 | dhcp->p = NULL; |
| 1183 | return; |
| 1184 | } |
| 1185 | } |
| 1186 | /* match transaction ID against what we expected */ |
| 1187 | if (ntohl(reply_msg->xid) != dhcp->xid) { |
| 1188 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | 2, ("transaction id mismatch\n")); |
| 1189 | pbuf_free(p); |
| 1190 | dhcp->p = NULL; |
| 1191 | return; |
| 1192 | } |
| 1193 | /* option fields could be unfold? */ |
| 1194 | if (dhcp_unfold_reply(dhcp) != ERR_OK) { |
| 1195 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | 2, ("problem unfolding DHCP message - too short on memory?\n")); |
| 1196 | pbuf_free(p); |
| 1197 | dhcp->p = NULL; |
| 1198 | return; |
| 1199 | } |
| 1200 | |
| 1201 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE, ("searching DHCP_OPTION_MESSAGE_TYPE\n")); |
| 1202 | /* obtain pointer to DHCP message type */ |
| 1203 | options_ptr = dhcp_get_option_ptr(dhcp, DHCP_OPTION_MESSAGE_TYPE); |
| 1204 | if (options_ptr == NULL) { |
| 1205 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | 1, ("DHCP_OPTION_MESSAGE_TYPE option not found\n")); |
| 1206 | pbuf_free(p); |
| 1207 | dhcp->p = NULL; |
| 1208 | return; |
| 1209 | } |
| 1210 | |
| 1211 | /* read DHCP message type */ |
| 1212 | msg_type = dhcp_get_option_byte(options_ptr + 2); |
| 1213 | /* message type is DHCP ACK? */ |
| 1214 | if (msg_type == DHCP_ACK) { |
| 1215 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | 1, ("DHCP_ACK received\n")); |
| 1216 | /* in requesting state? */ |
| 1217 | if (dhcp->state == DHCP_REQUESTING) { |
| 1218 | dhcp_handle_ack(netif); |
| 1219 | dhcp->request_timeout = 0; |
| 1220 | #if DHCP_DOES_ARP_CHECK |
| 1221 | /* check if the acknowledged lease address is already in use */ |
| 1222 | dhcp_check(netif); |
| 1223 | #else |
| 1224 | /* bind interface to the acknowledged lease address */ |
| 1225 | dhcp_bind(netif); |
| 1226 | #endif |
| 1227 | } |
| 1228 | /* already bound to the given lease address? */ |
| 1229 | else if ((dhcp->state == DHCP_REBOOTING) || (dhcp->state == DHCP_REBINDING) || (dhcp->state == DHCP_RENEWING)) { |
| 1230 | dhcp->request_timeout = 0; |
| 1231 | dhcp_bind(netif); |
| 1232 | } |
| 1233 | } |
| 1234 | /* received a DHCP_NAK in appropriate state? */ |
| 1235 | else if ((msg_type == DHCP_NAK) && |
| 1236 | ((dhcp->state == DHCP_REBOOTING) || (dhcp->state == DHCP_REQUESTING) || |
| 1237 | (dhcp->state == DHCP_REBINDING) || (dhcp->state == DHCP_RENEWING ))) { |
| 1238 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | 1, ("DHCP_NAK received\n")); |
| 1239 | dhcp->request_timeout = 0; |
| 1240 | dhcp_handle_nak(netif); |
| 1241 | } |
| 1242 | /* received a DHCP_OFFER in DHCP_SELECTING state? */ |
| 1243 | else if ((msg_type == DHCP_OFFER) && (dhcp->state == DHCP_SELECTING)) { |
| 1244 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | 1, ("DHCP_OFFER received in DHCP_SELECTING state\n")); |
| 1245 | dhcp->request_timeout = 0; |
| 1246 | /* remember offered lease */ |
| 1247 | dhcp_handle_offer(netif); |
| 1248 | } |
| 1249 | pbuf_free(p); |
| 1250 | dhcp->p = NULL; |
| 1251 | } |
| 1252 | |
| 1253 | |
| 1254 | static err_t dhcp_create_request(struct netif *netif) |
| 1255 | { |
| 1256 | struct dhcp *dhcp = netif->dhcp; |
| 1257 | u16_t i; |
| 1258 | LWIP_ASSERT("dhcp_create_request: dhcp->p_out == NULL", dhcp->p_out == NULL); |
| 1259 | LWIP_ASSERT("dhcp_create_request: dhcp->msg_out == NULL", dhcp->msg_out == NULL); |
| 1260 | dhcp->p_out = pbuf_alloc(PBUF_TRANSPORT, sizeof(struct dhcp_msg), PBUF_RAM); |
| 1261 | if (dhcp->p_out == NULL) { |
| 1262 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | 2, ("dhcp_create_request(): could not allocate pbuf\n")); |
| 1263 | return ERR_MEM; |
| 1264 | } |
| 1265 | /* give unique transaction identifier to this request */ |
| 1266 | dhcp->xid = xid++; |
| 1267 | |
| 1268 | dhcp->msg_out = (struct dhcp_msg *)dhcp->p_out->payload; |
| 1269 | |
| 1270 | dhcp->msg_out->op = DHCP_BOOTREQUEST; |
| 1271 | /* TODO: make link layer independent */ |
| 1272 | dhcp->msg_out->htype = DHCP_HTYPE_ETH; |
| 1273 | /* TODO: make link layer independent */ |
| 1274 | dhcp->msg_out->hlen = DHCP_HLEN_ETH; |
| 1275 | dhcp->msg_out->hops = 0; |
| 1276 | dhcp->msg_out->xid = htonl(dhcp->xid); |
| 1277 | dhcp->msg_out->secs = 0; |
| 1278 | dhcp->msg_out->flags = 0; |
| 1279 | dhcp->msg_out->ciaddr.addr = netif->ip_addr.addr; |
| 1280 | dhcp->msg_out->yiaddr.addr = 0; |
| 1281 | dhcp->msg_out->siaddr.addr = 0; |
| 1282 | dhcp->msg_out->giaddr.addr = 0; |
| 1283 | for (i = 0; i < DHCP_CHADDR_LEN; i++) { |
| 1284 | /* copy netif hardware address, pad with zeroes */ |
| 1285 | dhcp->msg_out->chaddr[i] = (i < netif->hwaddr_len) ? netif->hwaddr[i] : 0/* pad byte*/; |
| 1286 | } |
| 1287 | for (i = 0; i < DHCP_SNAME_LEN; i++) dhcp->msg_out->sname[i] = 0; |
| 1288 | for (i = 0; i < DHCP_FILE_LEN; i++) dhcp->msg_out->file[i] = 0; |
| 1289 | dhcp->msg_out->cookie = htonl(0x63825363UL); |
| 1290 | dhcp->options_out_len = 0; |
| 1291 | /* fill options field with an incrementing array (for debugging purposes) */ |
| 1292 | for (i = 0; i < DHCP_OPTIONS_LEN; i++) dhcp->msg_out->options[i] = i; |
| 1293 | return ERR_OK; |
| 1294 | } |
| 1295 | |
| 1296 | static void dhcp_delete_request(struct netif *netif) |
| 1297 | { |
| 1298 | struct dhcp *dhcp = netif->dhcp; |
| 1299 | LWIP_ASSERT("dhcp_free_msg: dhcp->p_out != NULL", dhcp->p_out != NULL); |
| 1300 | LWIP_ASSERT("dhcp_free_msg: dhcp->msg_out != NULL", dhcp->msg_out != NULL); |
| 1301 | pbuf_free(dhcp->p_out); |
| 1302 | dhcp->p_out = NULL; |
| 1303 | dhcp->msg_out = NULL; |
| 1304 | } |
| 1305 | |
| 1306 | /** |
| 1307 | * Add a DHCP message trailer |
| 1308 | * |
| 1309 | * Adds the END option to the DHCP message, and if |
| 1310 | * necessary, up to three padding bytes. |
| 1311 | */ |
| 1312 | |
| 1313 | static void dhcp_option_trailer(struct dhcp *dhcp) |
| 1314 | { |
| 1315 | LWIP_ASSERT("dhcp_option_trailer: dhcp->msg_out != NULL\n", dhcp->msg_out != NULL); |
| 1316 | LWIP_ASSERT("dhcp_option_trailer: dhcp->options_out_len < DHCP_OPTIONS_LEN\n", dhcp->options_out_len < DHCP_OPTIONS_LEN); |
| 1317 | dhcp->msg_out->options[dhcp->options_out_len++] = DHCP_OPTION_END; |
| 1318 | /* packet is too small, or not 4 byte aligned? */ |
| 1319 | while ((dhcp->options_out_len < DHCP_MIN_OPTIONS_LEN) || (dhcp->options_out_len & 3)) { |
| 1320 | /* LWIP_DEBUGF(DHCP_DEBUG,("dhcp_option_trailer:dhcp->options_out_len=%"U16_F", DHCP_OPTIONS_LEN=%"U16_F, dhcp->options_out_len, DHCP_OPTIONS_LEN)); */ |
| 1321 | LWIP_ASSERT("dhcp_option_trailer: dhcp->options_out_len < DHCP_OPTIONS_LEN\n", dhcp->options_out_len < DHCP_OPTIONS_LEN); |
| 1322 | /* add a fill/padding byte */ |
| 1323 | dhcp->msg_out->options[dhcp->options_out_len++] = 0; |
| 1324 | } |
| 1325 | } |
| 1326 | |
| 1327 | /** |
| 1328 | * Find the offset of a DHCP option inside the DHCP message. |
| 1329 | * |
| 1330 | * @param client DHCP client |
| 1331 | * @param option_type |
| 1332 | * |
| 1333 | * @return a byte offset into the UDP message where the option was found, or |
| 1334 | * zero if the given option was not found. |
| 1335 | */ |
| 1336 | static u8_t *dhcp_get_option_ptr(struct dhcp *dhcp, u8_t option_type) |
| 1337 | { |
| 1338 | u8_t overload = DHCP_OVERLOAD_NONE; |
| 1339 | |
| 1340 | /* options available? */ |
| 1341 | if ((dhcp->options_in != NULL) && (dhcp->options_in_len > 0)) { |
| 1342 | /* start with options field */ |
| 1343 | u8_t *options = (u8_t *)dhcp->options_in; |
| 1344 | u16_t offset = 0; |
| 1345 | /* at least 1 byte to read and no end marker, then at least 3 bytes to read? */ |
| 1346 | while ((offset < dhcp->options_in_len) && (options[offset] != DHCP_OPTION_END)) { |
| 1347 | /* LWIP_DEBUGF(DHCP_DEBUG, ("msg_offset=%"U16_F", q->len=%"U16_F, msg_offset, q->len)); */ |
| 1348 | /* are the sname and/or file field overloaded with options? */ |
| 1349 | if (options[offset] == DHCP_OPTION_OVERLOAD) { |
| 1350 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | 2, ("overloaded message detected\n")); |
| 1351 | /* skip option type and length */ |
| 1352 | offset += 2; |
| 1353 | overload = options[offset++]; |
| 1354 | } |
| 1355 | /* requested option found */ |
| 1356 | else if (options[offset] == option_type) { |
| 1357 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE, ("option found at offset %"U16_F" in options\n", offset)); |
| 1358 | return &options[offset]; |
| 1359 | /* skip option */ |
| 1360 | } else { |
| 1361 | LWIP_DEBUGF(DHCP_DEBUG, ("skipping option %"U16_F" in options\n", options[offset])); |
| 1362 | /* skip option type */ |
| 1363 | offset++; |
| 1364 | /* skip option length, and then length bytes */ |
| 1365 | offset += 1 + options[offset]; |
| 1366 | } |
| 1367 | } |
| 1368 | /* is this an overloaded message? */ |
| 1369 | if (overload != DHCP_OVERLOAD_NONE) { |
| 1370 | u16_t field_len; |
| 1371 | if (overload == DHCP_OVERLOAD_FILE) { |
| 1372 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | 1, ("overloaded file field\n")); |
| 1373 | options = (u8_t *)&dhcp->msg_in->file; |
| 1374 | field_len = DHCP_FILE_LEN; |
| 1375 | } else if (overload == DHCP_OVERLOAD_SNAME) { |
| 1376 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | 1, ("overloaded sname field\n")); |
| 1377 | options = (u8_t *)&dhcp->msg_in->sname; |
| 1378 | field_len = DHCP_SNAME_LEN; |
| 1379 | /* TODO: check if else if () is necessary */ |
| 1380 | } else { |
| 1381 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | 1, ("overloaded sname and file field\n")); |
| 1382 | options = (u8_t *)&dhcp->msg_in->sname; |
| 1383 | field_len = DHCP_FILE_LEN + DHCP_SNAME_LEN; |
| 1384 | } |
| 1385 | offset = 0; |
| 1386 | |
| 1387 | /* at least 1 byte to read and no end marker */ |
| 1388 | while ((offset < field_len) && (options[offset] != DHCP_OPTION_END)) { |
| 1389 | if (options[offset] == option_type) { |
| 1390 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE, ("option found at offset=%"U16_F"\n", offset)); |
| 1391 | return &options[offset]; |
| 1392 | /* skip option */ |
| 1393 | } else { |
| 1394 | LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE, ("skipping option %"U16_F"\n", options[offset])); |
| 1395 | /* skip option type */ |
| 1396 | offset++; |
| 1397 | offset += 1 + options[offset]; |
| 1398 | } |
| 1399 | } |
| 1400 | } |
| 1401 | } |
| 1402 | return 0; |
| 1403 | } |
| 1404 | |
| 1405 | /** |
| 1406 | * Return the byte of DHCP option data. |
| 1407 | * |
| 1408 | * @param client DHCP client. |
| 1409 | * @param ptr pointer obtained by dhcp_get_option_ptr(). |
| 1410 | * |
| 1411 | * @return byte value at the given address. |
| 1412 | */ |
| 1413 | static u8_t dhcp_get_option_byte(u8_t *ptr) |
| 1414 | { |
| 1415 | LWIP_DEBUGF(DHCP_DEBUG, ("option byte value=%"U16_F"\n", (u16_t)(*ptr))); |
| 1416 | return *ptr; |
| 1417 | } |
| 1418 | |
| 1419 | /** |
| 1420 | * Return the 16-bit value of DHCP option data. |
| 1421 | * |
| 1422 | * @param client DHCP client. |
| 1423 | * @param ptr pointer obtained by dhcp_get_option_ptr(). |
| 1424 | * |
| 1425 | * @return byte value at the given address. |
| 1426 | */ |
| 1427 | static u16_t dhcp_get_option_short(u8_t *ptr) |
| 1428 | { |
| 1429 | u16_t value; |
| 1430 | value = *ptr++ << 8; |
| 1431 | value |= *ptr; |
| 1432 | LWIP_DEBUGF(DHCP_DEBUG, ("option short value=%"U16_F"\n", value)); |
| 1433 | return value; |
| 1434 | } |
| 1435 | |
| 1436 | /** |
| 1437 | * Return the 32-bit value of DHCP option data. |
| 1438 | * |
| 1439 | * @param client DHCP client. |
| 1440 | * @param ptr pointer obtained by dhcp_get_option_ptr(). |
| 1441 | * |
| 1442 | * @return byte value at the given address. |
| 1443 | */ |
| 1444 | static u32_t dhcp_get_option_long(u8_t *ptr) |
| 1445 | { |
| 1446 | u32_t value; |
| 1447 | value = (u32_t)(*ptr++) << 24; |
| 1448 | value |= (u32_t)(*ptr++) << 16; |
| 1449 | value |= (u32_t)(*ptr++) << 8; |
| 1450 | value |= (u32_t)(*ptr++); |
| 1451 | LWIP_DEBUGF(DHCP_DEBUG, ("option long value=%"U32_F"\n", value)); |
| 1452 | return value; |
| 1453 | } |
| 1454 | |
| 1455 | #endif /* LWIP_DHCP */ |