Greg Hartman | 76d05dc | 2016-11-23 15:51:27 -0800 | [diff] [blame] | 1 | /** |
| 2 | * @file |
| 3 | * Dynamic Host Configuration Protocol client |
| 4 | * |
| 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 | * - Support for interfaces other than Ethernet (SLIP, PPP, ...) |
| 47 | * |
| 48 | * Please coordinate changes and requests with Leon Woestenberg |
| 49 | * <leon.woestenberg@gmx.net> |
| 50 | * |
| 51 | * Integration with your code: |
| 52 | * |
| 53 | * In lwip/dhcp.h |
| 54 | * #define DHCP_COARSE_TIMER_SECS (recommended 60 which is a minute) |
| 55 | * #define DHCP_FINE_TIMER_MSECS (recommended 500 which equals TCP coarse timer) |
| 56 | * |
| 57 | * Then have your application call dhcp_coarse_tmr() and |
| 58 | * dhcp_fine_tmr() on the defined intervals. |
| 59 | * |
| 60 | * dhcp_start(struct netif *netif); |
| 61 | * starts a DHCP client instance which configures the interface by |
| 62 | * obtaining an IP address lease and maintaining it. |
| 63 | * |
| 64 | * Use dhcp_release(netif) to end the lease and use dhcp_stop(netif) |
| 65 | * to remove the DHCP client. |
| 66 | * |
| 67 | */ |
| 68 | |
| 69 | #include "lwip/opt.h" |
| 70 | |
| 71 | #if LWIP_DHCP /* don't build if not configured for use in lwipopts.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/def.h" |
| 79 | #include "lwip/sys.h" |
| 80 | #include "lwip/dhcp.h" |
| 81 | #include "lwip/autoip.h" |
| 82 | #include "lwip/dns.h" |
| 83 | #include "netif/etharp.h" |
| 84 | |
| 85 | #include <string.h> |
| 86 | |
| 87 | /** Default for DHCP_GLOBAL_XID is 0xABCD0000 |
| 88 | * This can be changed by defining DHCP_GLOBAL_XID and DHCP_GLOBAL_XID_HEADER, e.g. |
| 89 | * #define DHCP_GLOBAL_XID_HEADER "stdlib.h" |
| 90 | * #define DHCP_GLOBAL_XID rand() |
| 91 | */ |
| 92 | #ifdef DHCP_GLOBAL_XID_HEADER |
| 93 | #include DHCP_GLOBAL_XID_HEADER /* include optional starting XID generation prototypes */ |
| 94 | #endif |
| 95 | |
| 96 | /** DHCP_OPTION_MAX_MSG_SIZE is set to the MTU |
| 97 | * MTU is checked to be big enough in dhcp_start */ |
| 98 | #define DHCP_MAX_MSG_LEN(netif) (netif->mtu) |
| 99 | #define DHCP_MAX_MSG_LEN_MIN_REQUIRED 576 |
| 100 | /** Minimum length for reply before packet is parsed */ |
| 101 | #define DHCP_MIN_REPLY_LEN 44 |
| 102 | |
| 103 | #define REBOOT_TRIES 2 |
| 104 | |
| 105 | /** Option handling: options are parsed in dhcp_parse_reply |
| 106 | * and saved in an array where other functions can load them from. |
| 107 | * This might be moved into the struct dhcp (not necessarily since |
| 108 | * lwIP is single-threaded and the array is only used while in recv |
| 109 | * callback). */ |
| 110 | #define DHCP_OPTION_IDX_OVERLOAD 0 |
| 111 | #define DHCP_OPTION_IDX_MSG_TYPE 1 |
| 112 | #define DHCP_OPTION_IDX_SERVER_ID 2 |
| 113 | #define DHCP_OPTION_IDX_LEASE_TIME 3 |
| 114 | #define DHCP_OPTION_IDX_T1 4 |
| 115 | #define DHCP_OPTION_IDX_T2 5 |
| 116 | #define DHCP_OPTION_IDX_SUBNET_MASK 6 |
| 117 | #define DHCP_OPTION_IDX_ROUTER 7 |
| 118 | #define DHCP_OPTION_IDX_DNS_SERVER 8 |
| 119 | #define DHCP_OPTION_IDX_MAX (DHCP_OPTION_IDX_DNS_SERVER + DNS_MAX_SERVERS) |
| 120 | |
| 121 | /** Holds the decoded option values, only valid while in dhcp_recv. |
| 122 | @todo: move this into struct dhcp? */ |
| 123 | u32_t dhcp_rx_options_val[DHCP_OPTION_IDX_MAX]; |
| 124 | /** Holds a flag which option was received and is contained in dhcp_rx_options_val, |
| 125 | only valid while in dhcp_recv. |
| 126 | @todo: move this into struct dhcp? */ |
| 127 | u8_t dhcp_rx_options_given[DHCP_OPTION_IDX_MAX]; |
| 128 | |
| 129 | #define dhcp_option_given(dhcp, idx) (dhcp_rx_options_given[idx] != 0) |
| 130 | #define dhcp_got_option(dhcp, idx) (dhcp_rx_options_given[idx] = 1) |
| 131 | #define dhcp_clear_option(dhcp, idx) (dhcp_rx_options_given[idx] = 0) |
| 132 | #define dhcp_clear_all_options(dhcp) (memset(dhcp_rx_options_given, 0, sizeof(dhcp_rx_options_given))) |
| 133 | #define dhcp_get_option_value(dhcp, idx) (dhcp_rx_options_val[idx]) |
| 134 | #define dhcp_set_option_value(dhcp, idx, val) (dhcp_rx_options_val[idx] = (val)) |
| 135 | |
| 136 | |
| 137 | /* DHCP client state machine functions */ |
| 138 | static err_t dhcp_discover(struct netif *netif); |
| 139 | static err_t dhcp_select(struct netif *netif); |
| 140 | static void dhcp_bind(struct netif *netif); |
| 141 | #if DHCP_DOES_ARP_CHECK |
| 142 | static err_t dhcp_decline(struct netif *netif); |
| 143 | #endif /* DHCP_DOES_ARP_CHECK */ |
| 144 | static err_t dhcp_rebind(struct netif *netif); |
| 145 | static err_t dhcp_reboot(struct netif *netif); |
| 146 | static void dhcp_set_state(struct dhcp *dhcp, u8_t new_state); |
| 147 | |
| 148 | /* receive, unfold, parse and free incoming messages */ |
| 149 | static void dhcp_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, ip_addr_t *addr, u16_t port); |
| 150 | |
| 151 | /* set the DHCP timers */ |
| 152 | static void dhcp_timeout(struct netif *netif); |
| 153 | static void dhcp_t1_timeout(struct netif *netif); |
| 154 | static void dhcp_t2_timeout(struct netif *netif); |
| 155 | |
| 156 | /* build outgoing messages */ |
| 157 | /* create a DHCP message, fill in common headers */ |
| 158 | static err_t dhcp_create_msg(struct netif *netif, struct dhcp *dhcp, u8_t message_type); |
| 159 | /* free a DHCP request */ |
| 160 | static void dhcp_delete_msg(struct dhcp *dhcp); |
| 161 | /* add a DHCP option (type, then length in bytes) */ |
| 162 | static void dhcp_option(struct dhcp *dhcp, u8_t option_type, u8_t option_len); |
| 163 | /* add option values */ |
| 164 | static void dhcp_option_byte(struct dhcp *dhcp, u8_t value); |
| 165 | static void dhcp_option_short(struct dhcp *dhcp, u16_t value); |
| 166 | static void dhcp_option_long(struct dhcp *dhcp, u32_t value); |
| 167 | /* always add the DHCP options trailer to end and pad */ |
| 168 | static void dhcp_option_trailer(struct dhcp *dhcp); |
| 169 | |
| 170 | /** |
| 171 | * Back-off the DHCP client (because of a received NAK response). |
| 172 | * |
| 173 | * Back-off the DHCP client because of a received NAK. Receiving a |
| 174 | * NAK means the client asked for something non-sensible, for |
| 175 | * example when it tries to renew a lease obtained on another network. |
| 176 | * |
| 177 | * We clear any existing set IP address and restart DHCP negotiation |
| 178 | * afresh (as per RFC2131 3.2.3). |
| 179 | * |
| 180 | * @param netif the netif under DHCP control |
| 181 | */ |
| 182 | static void |
| 183 | dhcp_handle_nak(struct netif *netif) |
| 184 | { |
| 185 | struct dhcp *dhcp = netif->dhcp; |
| 186 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_handle_nak(netif=%p) %c%c%"U16_F"\n", |
| 187 | (void*)netif, netif->name[0], netif->name[1], (u16_t)netif->num)); |
| 188 | /* Set the interface down since the address must no longer be used, as per RFC2131 */ |
| 189 | netif_set_down(netif); |
| 190 | /* remove IP address from interface */ |
| 191 | netif_set_ipaddr(netif, IP_ADDR_ANY); |
| 192 | netif_set_gw(netif, IP_ADDR_ANY); |
| 193 | netif_set_netmask(netif, IP_ADDR_ANY); |
| 194 | /* Change to a defined state */ |
| 195 | dhcp_set_state(dhcp, DHCP_BACKING_OFF); |
| 196 | /* We can immediately restart discovery */ |
| 197 | dhcp_discover(netif); |
| 198 | } |
| 199 | |
| 200 | #if DHCP_DOES_ARP_CHECK |
| 201 | /** |
| 202 | * Checks if the offered IP address is already in use. |
| 203 | * |
| 204 | * It does so by sending an ARP request for the offered address and |
| 205 | * entering CHECKING state. If no ARP reply is received within a small |
| 206 | * interval, the address is assumed to be free for use by us. |
| 207 | * |
| 208 | * @param netif the netif under DHCP control |
| 209 | */ |
| 210 | static void |
| 211 | dhcp_check(struct netif *netif) |
| 212 | { |
| 213 | struct dhcp *dhcp = netif->dhcp; |
| 214 | err_t result; |
| 215 | u16_t msecs; |
| 216 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_check(netif=%p) %c%c\n", (void *)netif, (s16_t)netif->name[0], |
| 217 | (s16_t)netif->name[1])); |
| 218 | dhcp_set_state(dhcp, DHCP_CHECKING); |
| 219 | /* create an ARP query for the offered IP address, expecting that no host |
| 220 | responds, as the IP address should not be in use. */ |
| 221 | result = etharp_query(netif, &dhcp->offered_ip_addr, NULL); |
| 222 | if (result != ERR_OK) { |
| 223 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, ("dhcp_check: could not perform ARP query\n")); |
| 224 | } |
| 225 | dhcp->tries++; |
| 226 | msecs = 500; |
| 227 | dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS; |
| 228 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_check(): set request timeout %"U16_F" msecs\n", msecs)); |
| 229 | } |
| 230 | #endif /* DHCP_DOES_ARP_CHECK */ |
| 231 | |
| 232 | /** |
| 233 | * Remember the configuration offered by a DHCP server. |
| 234 | * |
| 235 | * @param netif the netif under DHCP control |
| 236 | */ |
| 237 | static void |
| 238 | dhcp_handle_offer(struct netif *netif) |
| 239 | { |
| 240 | struct dhcp *dhcp = netif->dhcp; |
| 241 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_handle_offer(netif=%p) %c%c%"U16_F"\n", |
| 242 | (void*)netif, netif->name[0], netif->name[1], (u16_t)netif->num)); |
| 243 | /* obtain the server address */ |
| 244 | if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_SERVER_ID)) { |
| 245 | ip4_addr_set_u32(&dhcp->server_ip_addr, htonl(dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_SERVER_ID))); |
| 246 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_handle_offer(): server 0x%08"X32_F"\n", |
| 247 | ip4_addr_get_u32(&dhcp->server_ip_addr))); |
| 248 | /* remember offered address */ |
| 249 | ip_addr_copy(dhcp->offered_ip_addr, dhcp->msg_in->yiaddr); |
| 250 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_handle_offer(): offer for 0x%08"X32_F"\n", |
| 251 | ip4_addr_get_u32(&dhcp->offered_ip_addr))); |
| 252 | |
| 253 | dhcp_select(netif); |
| 254 | } else { |
| 255 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, |
| 256 | ("dhcp_handle_offer(netif=%p) did not get server ID!\n", (void*)netif)); |
| 257 | } |
| 258 | } |
| 259 | |
| 260 | /** |
| 261 | * Select a DHCP server offer out of all offers. |
| 262 | * |
| 263 | * Simply select the first offer received. |
| 264 | * |
| 265 | * @param netif the netif under DHCP control |
| 266 | * @return lwIP specific error (see error.h) |
| 267 | */ |
| 268 | static err_t |
| 269 | dhcp_select(struct netif *netif) |
| 270 | { |
| 271 | struct dhcp *dhcp = netif->dhcp; |
| 272 | err_t result; |
| 273 | u16_t msecs; |
| 274 | |
| 275 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_select(netif=%p) %c%c%"U16_F"\n", (void*)netif, netif->name[0], netif->name[1], (u16_t)netif->num)); |
| 276 | dhcp_set_state(dhcp, DHCP_REQUESTING); |
| 277 | |
| 278 | /* create and initialize the DHCP message header */ |
| 279 | result = dhcp_create_msg(netif, dhcp, DHCP_REQUEST); |
| 280 | if (result == ERR_OK) { |
| 281 | dhcp_option(dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN); |
| 282 | dhcp_option_short(dhcp, DHCP_MAX_MSG_LEN(netif)); |
| 283 | |
| 284 | /* MUST request the offered IP address */ |
| 285 | dhcp_option(dhcp, DHCP_OPTION_REQUESTED_IP, 4); |
| 286 | dhcp_option_long(dhcp, ntohl(ip4_addr_get_u32(&dhcp->offered_ip_addr))); |
| 287 | |
| 288 | dhcp_option(dhcp, DHCP_OPTION_SERVER_ID, 4); |
| 289 | dhcp_option_long(dhcp, ntohl(ip4_addr_get_u32(&dhcp->server_ip_addr))); |
| 290 | |
| 291 | dhcp_option(dhcp, DHCP_OPTION_PARAMETER_REQUEST_LIST, 4/*num options*/); |
| 292 | dhcp_option_byte(dhcp, DHCP_OPTION_SUBNET_MASK); |
| 293 | dhcp_option_byte(dhcp, DHCP_OPTION_ROUTER); |
| 294 | dhcp_option_byte(dhcp, DHCP_OPTION_BROADCAST); |
| 295 | dhcp_option_byte(dhcp, DHCP_OPTION_DNS_SERVER); |
| 296 | |
| 297 | #if LWIP_NETIF_HOSTNAME |
| 298 | if (netif->hostname != NULL) { |
| 299 | const char *p = (const char*)netif->hostname; |
| 300 | u8_t namelen = (u8_t)strlen(p); |
| 301 | if (namelen > 0) { |
| 302 | LWIP_ASSERT("DHCP: hostname is too long!", namelen < 255); |
| 303 | dhcp_option(dhcp, DHCP_OPTION_HOSTNAME, namelen); |
| 304 | while (*p) { |
| 305 | dhcp_option_byte(dhcp, *p++); |
| 306 | } |
| 307 | } |
| 308 | } |
| 309 | #endif /* LWIP_NETIF_HOSTNAME */ |
| 310 | |
| 311 | dhcp_option_trailer(dhcp); |
| 312 | /* shrink the pbuf to the actual content length */ |
| 313 | pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len); |
| 314 | |
| 315 | /* send broadcast to any DHCP server */ |
| 316 | udp_sendto_if(dhcp->pcb, dhcp->p_out, IP_ADDR_BROADCAST, DHCP_SERVER_PORT, netif); |
| 317 | dhcp_delete_msg(dhcp); |
| 318 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_select: REQUESTING\n")); |
| 319 | } else { |
| 320 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, ("dhcp_select: could not allocate DHCP request\n")); |
| 321 | } |
| 322 | dhcp->tries++; |
| 323 | msecs = (dhcp->tries < 6 ? 1 << dhcp->tries : 60) * 1000; |
| 324 | dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS; |
| 325 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_select(): set request timeout %"U16_F" msecs\n", msecs)); |
| 326 | return result; |
| 327 | } |
| 328 | |
| 329 | /** |
| 330 | * The DHCP timer that checks for lease renewal/rebind timeouts. |
| 331 | */ |
| 332 | void |
| 333 | dhcp_coarse_tmr() |
| 334 | { |
| 335 | struct netif *netif = netif_list; |
| 336 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_coarse_tmr()\n")); |
| 337 | /* iterate through all network interfaces */ |
| 338 | while (netif != NULL) { |
| 339 | /* only act on DHCP configured interfaces */ |
| 340 | if (netif->dhcp != NULL) { |
| 341 | /* timer is active (non zero), and triggers (zeroes) now? */ |
| 342 | if (netif->dhcp->t2_timeout-- == 1) { |
| 343 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_coarse_tmr(): t2 timeout\n")); |
| 344 | /* this clients' rebind timeout triggered */ |
| 345 | dhcp_t2_timeout(netif); |
| 346 | /* timer is active (non zero), and triggers (zeroes) now */ |
| 347 | } else if (netif->dhcp->t1_timeout-- == 1) { |
| 348 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_coarse_tmr(): t1 timeout\n")); |
| 349 | /* this clients' renewal timeout triggered */ |
| 350 | dhcp_t1_timeout(netif); |
| 351 | } |
| 352 | } |
| 353 | /* proceed to next netif */ |
| 354 | netif = netif->next; |
| 355 | } |
| 356 | } |
| 357 | |
| 358 | /** |
| 359 | * DHCP transaction timeout handling |
| 360 | * |
| 361 | * A DHCP server is expected to respond within a short period of time. |
| 362 | * This timer checks whether an outstanding DHCP request is timed out. |
| 363 | */ |
| 364 | void |
| 365 | dhcp_fine_tmr() |
| 366 | { |
| 367 | struct netif *netif = netif_list; |
| 368 | /* loop through netif's */ |
| 369 | while (netif != NULL) { |
| 370 | /* only act on DHCP configured interfaces */ |
| 371 | if (netif->dhcp != NULL) { |
| 372 | /* timer is active (non zero), and is about to trigger now */ |
| 373 | if (netif->dhcp->request_timeout > 1) { |
| 374 | netif->dhcp->request_timeout--; |
| 375 | } |
| 376 | else if (netif->dhcp->request_timeout == 1) { |
| 377 | netif->dhcp->request_timeout--; |
| 378 | /* { netif->dhcp->request_timeout == 0 } */ |
| 379 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_fine_tmr(): request timeout\n")); |
| 380 | /* this client's request timeout triggered */ |
| 381 | dhcp_timeout(netif); |
| 382 | } |
| 383 | } |
| 384 | /* proceed to next network interface */ |
| 385 | netif = netif->next; |
| 386 | } |
| 387 | } |
| 388 | |
| 389 | /** |
| 390 | * A DHCP negotiation transaction, or ARP request, has timed out. |
| 391 | * |
| 392 | * The timer that was started with the DHCP or ARP request has |
| 393 | * timed out, indicating no response was received in time. |
| 394 | * |
| 395 | * @param netif the netif under DHCP control |
| 396 | */ |
| 397 | static void |
| 398 | dhcp_timeout(struct netif *netif) |
| 399 | { |
| 400 | struct dhcp *dhcp = netif->dhcp; |
| 401 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_timeout()\n")); |
| 402 | /* back-off period has passed, or server selection timed out */ |
| 403 | if ((dhcp->state == DHCP_BACKING_OFF) || (dhcp->state == DHCP_SELECTING)) { |
| 404 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_timeout(): restarting discovery\n")); |
| 405 | dhcp_discover(netif); |
| 406 | /* receiving the requested lease timed out */ |
| 407 | } else if (dhcp->state == DHCP_REQUESTING) { |
| 408 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_timeout(): REQUESTING, DHCP request timed out\n")); |
| 409 | if (dhcp->tries <= 5) { |
| 410 | dhcp_select(netif); |
| 411 | } else { |
| 412 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_timeout(): REQUESTING, releasing, restarting\n")); |
| 413 | dhcp_release(netif); |
| 414 | dhcp_discover(netif); |
| 415 | } |
| 416 | #if DHCP_DOES_ARP_CHECK |
| 417 | /* received no ARP reply for the offered address (which is good) */ |
| 418 | } else if (dhcp->state == DHCP_CHECKING) { |
| 419 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_timeout(): CHECKING, ARP request timed out\n")); |
| 420 | if (dhcp->tries <= 1) { |
| 421 | dhcp_check(netif); |
| 422 | /* no ARP replies on the offered address, |
| 423 | looks like the IP address is indeed free */ |
| 424 | } else { |
| 425 | /* bind the interface to the offered address */ |
| 426 | dhcp_bind(netif); |
| 427 | } |
| 428 | #endif /* DHCP_DOES_ARP_CHECK */ |
| 429 | } |
| 430 | /* did not get response to renew request? */ |
| 431 | else if (dhcp->state == DHCP_RENEWING) { |
| 432 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_timeout(): RENEWING, DHCP request timed out\n")); |
| 433 | /* just retry renewal */ |
| 434 | /* note that the rebind timer will eventually time-out if renew does not work */ |
| 435 | dhcp_renew(netif); |
| 436 | /* did not get response to rebind request? */ |
| 437 | } else if (dhcp->state == DHCP_REBINDING) { |
| 438 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_timeout(): REBINDING, DHCP request timed out\n")); |
| 439 | if (dhcp->tries <= 8) { |
| 440 | dhcp_rebind(netif); |
| 441 | } else { |
| 442 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_timeout(): RELEASING, DISCOVERING\n")); |
| 443 | dhcp_release(netif); |
| 444 | dhcp_discover(netif); |
| 445 | } |
| 446 | } else if (dhcp->state == DHCP_REBOOTING) { |
| 447 | if (dhcp->tries < REBOOT_TRIES) { |
| 448 | dhcp_reboot(netif); |
| 449 | } else { |
| 450 | dhcp_discover(netif); |
| 451 | } |
| 452 | } |
| 453 | } |
| 454 | |
| 455 | /** |
| 456 | * The renewal period has timed out. |
| 457 | * |
| 458 | * @param netif the netif under DHCP control |
| 459 | */ |
| 460 | static void |
| 461 | dhcp_t1_timeout(struct netif *netif) |
| 462 | { |
| 463 | struct dhcp *dhcp = netif->dhcp; |
| 464 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_t1_timeout()\n")); |
| 465 | if ((dhcp->state == DHCP_REQUESTING) || (dhcp->state == DHCP_BOUND) || |
| 466 | (dhcp->state == DHCP_RENEWING)) { |
| 467 | /* just retry to renew - note that the rebind timer (t2) will |
| 468 | * eventually time-out if renew tries fail. */ |
| 469 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, |
| 470 | ("dhcp_t1_timeout(): must renew\n")); |
| 471 | /* This slightly different to RFC2131: DHCPREQUEST will be sent from state |
| 472 | DHCP_RENEWING, not DHCP_BOUND */ |
| 473 | dhcp_renew(netif); |
| 474 | } |
| 475 | } |
| 476 | |
| 477 | /** |
| 478 | * The rebind period has timed out. |
| 479 | * |
| 480 | * @param netif the netif under DHCP control |
| 481 | */ |
| 482 | static void |
| 483 | dhcp_t2_timeout(struct netif *netif) |
| 484 | { |
| 485 | struct dhcp *dhcp = netif->dhcp; |
| 486 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_t2_timeout()\n")); |
| 487 | if ((dhcp->state == DHCP_REQUESTING) || (dhcp->state == DHCP_BOUND) || |
| 488 | (dhcp->state == DHCP_RENEWING)) { |
| 489 | /* just retry to rebind */ |
| 490 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, |
| 491 | ("dhcp_t2_timeout(): must rebind\n")); |
| 492 | /* This slightly different to RFC2131: DHCPREQUEST will be sent from state |
| 493 | DHCP_REBINDING, not DHCP_BOUND */ |
| 494 | dhcp_rebind(netif); |
| 495 | } |
| 496 | } |
| 497 | |
| 498 | /** |
| 499 | * Handle a DHCP ACK packet |
| 500 | * |
| 501 | * @param netif the netif under DHCP control |
| 502 | */ |
| 503 | static void |
| 504 | dhcp_handle_ack(struct netif *netif) |
| 505 | { |
| 506 | struct dhcp *dhcp = netif->dhcp; |
| 507 | #if LWIP_DNS |
| 508 | u8_t n; |
| 509 | #endif /* LWIP_DNS */ |
| 510 | |
| 511 | /* clear options we might not get from the ACK */ |
| 512 | ip_addr_set_zero(&dhcp->offered_sn_mask); |
| 513 | ip_addr_set_zero(&dhcp->offered_gw_addr); |
| 514 | #if LWIP_DHCP_BOOTP_FILE |
| 515 | ip_addr_set_zero(&dhcp->offered_si_addr); |
| 516 | #endif /* LWIP_DHCP_BOOTP_FILE */ |
| 517 | |
| 518 | /* lease time given? */ |
| 519 | if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_LEASE_TIME)) { |
| 520 | /* remember offered lease time */ |
| 521 | dhcp->offered_t0_lease = dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_LEASE_TIME); |
| 522 | } |
| 523 | /* renewal period given? */ |
| 524 | if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_T1)) { |
| 525 | /* remember given renewal period */ |
| 526 | dhcp->offered_t1_renew = dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_T1); |
| 527 | } else { |
| 528 | /* calculate safe periods for renewal */ |
| 529 | dhcp->offered_t1_renew = dhcp->offered_t0_lease / 2; |
| 530 | } |
| 531 | |
| 532 | /* renewal period given? */ |
| 533 | if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_T2)) { |
| 534 | /* remember given rebind period */ |
| 535 | dhcp->offered_t2_rebind = dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_T2); |
| 536 | } else { |
| 537 | /* calculate safe periods for rebinding */ |
| 538 | dhcp->offered_t2_rebind = dhcp->offered_t0_lease; |
| 539 | } |
| 540 | |
| 541 | /* (y)our internet address */ |
| 542 | ip_addr_copy(dhcp->offered_ip_addr, dhcp->msg_in->yiaddr); |
| 543 | |
| 544 | #if LWIP_DHCP_BOOTP_FILE |
| 545 | /* copy boot server address, |
| 546 | boot file name copied in dhcp_parse_reply if not overloaded */ |
| 547 | ip_addr_copy(dhcp->offered_si_addr, dhcp->msg_in->siaddr); |
| 548 | #endif /* LWIP_DHCP_BOOTP_FILE */ |
| 549 | |
| 550 | /* subnet mask given? */ |
| 551 | if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_SUBNET_MASK)) { |
| 552 | /* remember given subnet mask */ |
| 553 | ip4_addr_set_u32(&dhcp->offered_sn_mask, htonl(dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_SUBNET_MASK))); |
| 554 | dhcp->subnet_mask_given = 1; |
| 555 | } else { |
| 556 | dhcp->subnet_mask_given = 0; |
| 557 | } |
| 558 | |
| 559 | /* gateway router */ |
| 560 | if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_ROUTER)) { |
| 561 | ip4_addr_set_u32(&dhcp->offered_gw_addr, htonl(dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_ROUTER))); |
| 562 | } |
| 563 | |
| 564 | #if LWIP_DNS |
| 565 | /* DNS servers */ |
| 566 | n = 0; |
| 567 | while(dhcp_option_given(dhcp, DHCP_OPTION_IDX_DNS_SERVER + n) && (n < DNS_MAX_SERVERS)) { |
| 568 | ip_addr_t dns_addr; |
| 569 | ip4_addr_set_u32(&dns_addr, htonl(dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_DNS_SERVER + n))); |
| 570 | dns_setserver(n, &dns_addr); |
| 571 | n++; |
| 572 | } |
| 573 | #endif /* LWIP_DNS */ |
| 574 | } |
| 575 | |
| 576 | /** Set a statically allocated struct dhcp to work with. |
| 577 | * Using this prevents dhcp_start to allocate it using mem_malloc. |
| 578 | * |
| 579 | * @param netif the netif for which to set the struct dhcp |
| 580 | * @param dhcp (uninitialised) dhcp struct allocated by the application |
| 581 | */ |
| 582 | void |
| 583 | dhcp_set_struct(struct netif *netif, struct dhcp *dhcp) |
| 584 | { |
| 585 | LWIP_ASSERT("netif != NULL", netif != NULL); |
| 586 | LWIP_ASSERT("dhcp != NULL", dhcp != NULL); |
| 587 | LWIP_ASSERT("netif already has a struct dhcp set", netif->dhcp == NULL); |
| 588 | |
| 589 | /* clear data structure */ |
| 590 | memset(dhcp, 0, sizeof(struct dhcp)); |
| 591 | /* dhcp_set_state(&dhcp, DHCP_OFF); */ |
| 592 | netif->dhcp = dhcp; |
| 593 | } |
| 594 | |
| 595 | /** Removes a struct dhcp from a netif. |
| 596 | * |
| 597 | * ATTENTION: Only use this when not using dhcp_set_struct() to allocate the |
| 598 | * struct dhcp since the memory is passed back to the heap. |
| 599 | * |
| 600 | * @param netif the netif from which to remove the struct dhcp |
| 601 | */ |
| 602 | void dhcp_cleanup(struct netif *netif) |
| 603 | { |
| 604 | LWIP_ASSERT("netif != NULL", netif != NULL); |
| 605 | |
| 606 | if (netif->dhcp != NULL) { |
| 607 | mem_free(netif->dhcp); |
| 608 | netif->dhcp = NULL; |
| 609 | } |
| 610 | } |
| 611 | |
| 612 | /** |
| 613 | * Start DHCP negotiation for a network interface. |
| 614 | * |
| 615 | * If no DHCP client instance was attached to this interface, |
| 616 | * a new client is created first. If a DHCP client instance |
| 617 | * was already present, it restarts negotiation. |
| 618 | * |
| 619 | * @param netif The lwIP network interface |
| 620 | * @return lwIP error code |
| 621 | * - ERR_OK - No error |
| 622 | * - ERR_MEM - Out of memory |
| 623 | */ |
| 624 | err_t |
| 625 | dhcp_start(struct netif *netif) |
| 626 | { |
| 627 | struct dhcp *dhcp; |
| 628 | err_t result = ERR_OK; |
| 629 | |
| 630 | LWIP_ERROR("netif != NULL", (netif != NULL), return ERR_ARG;); |
| 631 | dhcp = netif->dhcp; |
| 632 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_start(netif=%p) %c%c%"U16_F"\n", (void*)netif, netif->name[0], netif->name[1], (u16_t)netif->num)); |
| 633 | /* Remove the flag that says this netif is handled by DHCP, |
| 634 | it is set when we succeeded starting. */ |
| 635 | netif->flags &= ~NETIF_FLAG_DHCP; |
| 636 | |
| 637 | /* check hwtype of the netif */ |
| 638 | if ((netif->flags & NETIF_FLAG_ETHARP) == 0) { |
| 639 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): No ETHARP netif\n")); |
| 640 | return ERR_ARG; |
| 641 | } |
| 642 | |
| 643 | /* check MTU of the netif */ |
| 644 | if (netif->mtu < DHCP_MAX_MSG_LEN_MIN_REQUIRED) { |
| 645 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): Cannot use this netif with DHCP: MTU is too small\n")); |
| 646 | return ERR_MEM; |
| 647 | } |
| 648 | |
| 649 | /* no DHCP client attached yet? */ |
| 650 | if (dhcp == NULL) { |
| 651 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): starting new DHCP client\n")); |
| 652 | dhcp = (struct dhcp *)mem_malloc(sizeof(struct dhcp)); |
| 653 | if (dhcp == NULL) { |
| 654 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): could not allocate dhcp\n")); |
| 655 | return ERR_MEM; |
| 656 | } |
| 657 | /* store this dhcp client in the netif */ |
| 658 | netif->dhcp = dhcp; |
| 659 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): allocated dhcp")); |
| 660 | /* already has DHCP client attached */ |
| 661 | } else { |
| 662 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_start(): restarting DHCP configuration\n")); |
| 663 | if (dhcp->pcb != NULL) { |
| 664 | udp_remove(dhcp->pcb); |
| 665 | } |
| 666 | LWIP_ASSERT("pbuf p_out wasn't freed", dhcp->p_out == NULL); |
| 667 | LWIP_ASSERT("reply wasn't freed", dhcp->msg_in == NULL ); |
| 668 | } |
| 669 | |
| 670 | /* clear data structure */ |
| 671 | memset(dhcp, 0, sizeof(struct dhcp)); |
| 672 | /* dhcp_set_state(&dhcp, DHCP_OFF); */ |
| 673 | /* allocate UDP PCB */ |
| 674 | dhcp->pcb = udp_new(); |
| 675 | if (dhcp->pcb == NULL) { |
| 676 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): could not obtain pcb\n")); |
| 677 | return ERR_MEM; |
| 678 | } |
| 679 | dhcp->pcb->so_options |= SOF_BROADCAST; |
| 680 | /* set up local and remote port for the pcb */ |
| 681 | udp_bind(dhcp->pcb, IP_ADDR_ANY, DHCP_CLIENT_PORT); |
| 682 | udp_connect(dhcp->pcb, IP_ADDR_ANY, DHCP_SERVER_PORT); |
| 683 | /* set up the recv callback and argument */ |
| 684 | udp_recv(dhcp->pcb, dhcp_recv, netif); |
| 685 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): starting DHCP configuration\n")); |
| 686 | /* (re)start the DHCP negotiation */ |
| 687 | result = dhcp_discover(netif); |
| 688 | if (result != ERR_OK) { |
| 689 | /* free resources allocated above */ |
| 690 | dhcp_stop(netif); |
| 691 | return ERR_MEM; |
| 692 | } |
| 693 | /* Set the flag that says this netif is handled by DHCP. */ |
| 694 | netif->flags |= NETIF_FLAG_DHCP; |
| 695 | return result; |
| 696 | } |
| 697 | |
| 698 | /** |
| 699 | * Inform a DHCP server of our manual configuration. |
| 700 | * |
| 701 | * This informs DHCP servers of our fixed IP address configuration |
| 702 | * by sending an INFORM message. It does not involve DHCP address |
| 703 | * configuration, it is just here to be nice to the network. |
| 704 | * |
| 705 | * @param netif The lwIP network interface |
| 706 | */ |
| 707 | void |
| 708 | dhcp_inform(struct netif *netif) |
| 709 | { |
| 710 | struct dhcp dhcp; |
| 711 | err_t result = ERR_OK; |
| 712 | struct udp_pcb *pcb; |
| 713 | |
| 714 | LWIP_ERROR("netif != NULL", (netif != NULL), return;); |
| 715 | |
| 716 | memset(&dhcp, 0, sizeof(struct dhcp)); |
| 717 | dhcp_set_state(&dhcp, DHCP_INFORM); |
| 718 | |
| 719 | if ((netif->dhcp != NULL) && (netif->dhcp->pcb != NULL)) { |
| 720 | /* re-use existing pcb */ |
| 721 | pcb = netif->dhcp->pcb; |
| 722 | } else { |
| 723 | pcb = udp_new(); |
| 724 | if (pcb == NULL) { |
| 725 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_inform(): could not obtain pcb")); |
| 726 | return; |
| 727 | } |
| 728 | dhcp.pcb = pcb; |
| 729 | dhcp.pcb->so_options |= SOF_BROADCAST; |
| 730 | udp_bind(dhcp.pcb, IP_ADDR_ANY, DHCP_CLIENT_PORT); |
| 731 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_inform(): created new udp pcb\n")); |
| 732 | } |
| 733 | /* create and initialize the DHCP message header */ |
| 734 | result = dhcp_create_msg(netif, &dhcp, DHCP_INFORM); |
| 735 | if (result == ERR_OK) { |
| 736 | dhcp_option(&dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN); |
| 737 | dhcp_option_short(&dhcp, DHCP_MAX_MSG_LEN(netif)); |
| 738 | |
| 739 | dhcp_option_trailer(&dhcp); |
| 740 | |
| 741 | pbuf_realloc(dhcp.p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp.options_out_len); |
| 742 | |
| 743 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_inform: INFORMING\n")); |
| 744 | udp_sendto_if(pcb, dhcp.p_out, IP_ADDR_BROADCAST, DHCP_SERVER_PORT, netif); |
| 745 | dhcp_delete_msg(&dhcp); |
| 746 | } else { |
| 747 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_inform: could not allocate DHCP request\n")); |
| 748 | } |
| 749 | |
| 750 | if (dhcp.pcb != NULL) { |
| 751 | /* otherwise, the existing pcb was used */ |
| 752 | udp_remove(dhcp.pcb); |
| 753 | } |
| 754 | } |
| 755 | |
| 756 | /** Handle a possible change in the network configuration. |
| 757 | * |
| 758 | * This enters the REBOOTING state to verify that the currently bound |
| 759 | * address is still valid. |
| 760 | */ |
| 761 | void |
| 762 | dhcp_network_changed(struct netif *netif) |
| 763 | { |
| 764 | struct dhcp *dhcp = netif->dhcp; |
| 765 | if (!dhcp) |
| 766 | return; |
| 767 | switch (dhcp->state) { |
| 768 | case DHCP_REBINDING: |
| 769 | case DHCP_RENEWING: |
| 770 | case DHCP_BOUND: |
| 771 | case DHCP_REBOOTING: |
| 772 | netif_set_down(netif); |
| 773 | dhcp->tries = 0; |
| 774 | dhcp_reboot(netif); |
| 775 | break; |
| 776 | case DHCP_OFF: |
| 777 | /* stay off */ |
| 778 | break; |
| 779 | default: |
| 780 | dhcp->tries = 0; |
| 781 | #if LWIP_DHCP_AUTOIP_COOP |
| 782 | if(dhcp->autoip_coop_state == DHCP_AUTOIP_COOP_STATE_ON) { |
| 783 | autoip_stop(netif); |
| 784 | dhcp->autoip_coop_state = DHCP_AUTOIP_COOP_STATE_OFF; |
| 785 | } |
| 786 | #endif /* LWIP_DHCP_AUTOIP_COOP */ |
| 787 | dhcp_discover(netif); |
| 788 | break; |
| 789 | } |
| 790 | } |
| 791 | |
| 792 | #if DHCP_DOES_ARP_CHECK |
| 793 | /** |
| 794 | * Match an ARP reply with the offered IP address. |
| 795 | * |
| 796 | * @param netif the network interface on which the reply was received |
| 797 | * @param addr The IP address we received a reply from |
| 798 | */ |
| 799 | void dhcp_arp_reply(struct netif *netif, ip_addr_t *addr) |
| 800 | { |
| 801 | LWIP_ERROR("netif != NULL", (netif != NULL), return;); |
| 802 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_arp_reply()\n")); |
| 803 | /* is a DHCP client doing an ARP check? */ |
| 804 | if ((netif->dhcp != NULL) && (netif->dhcp->state == DHCP_CHECKING)) { |
| 805 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_arp_reply(): CHECKING, arp reply for 0x%08"X32_F"\n", |
| 806 | ip4_addr_get_u32(addr))); |
| 807 | /* did a host respond with the address we |
| 808 | were offered by the DHCP server? */ |
| 809 | if (ip_addr_cmp(addr, &netif->dhcp->offered_ip_addr)) { |
| 810 | /* we will not accept the offered address */ |
| 811 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE | LWIP_DBG_LEVEL_WARNING, |
| 812 | ("dhcp_arp_reply(): arp reply matched with offered address, declining\n")); |
| 813 | dhcp_decline(netif); |
| 814 | } |
| 815 | } |
| 816 | } |
| 817 | |
| 818 | /** |
| 819 | * Decline an offered lease. |
| 820 | * |
| 821 | * Tell the DHCP server we do not accept the offered address. |
| 822 | * One reason to decline the lease is when we find out the address |
| 823 | * is already in use by another host (through ARP). |
| 824 | * |
| 825 | * @param netif the netif under DHCP control |
| 826 | */ |
| 827 | static err_t |
| 828 | dhcp_decline(struct netif *netif) |
| 829 | { |
| 830 | struct dhcp *dhcp = netif->dhcp; |
| 831 | err_t result = ERR_OK; |
| 832 | u16_t msecs; |
| 833 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_decline()\n")); |
| 834 | dhcp_set_state(dhcp, DHCP_BACKING_OFF); |
| 835 | /* create and initialize the DHCP message header */ |
| 836 | result = dhcp_create_msg(netif, dhcp, DHCP_DECLINE); |
| 837 | if (result == ERR_OK) { |
| 838 | dhcp_option(dhcp, DHCP_OPTION_REQUESTED_IP, 4); |
| 839 | dhcp_option_long(dhcp, ntohl(ip4_addr_get_u32(&dhcp->offered_ip_addr))); |
| 840 | |
| 841 | dhcp_option_trailer(dhcp); |
| 842 | /* resize pbuf to reflect true size of options */ |
| 843 | pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len); |
| 844 | |
| 845 | /* per section 4.4.4, broadcast DECLINE messages */ |
| 846 | udp_sendto_if(dhcp->pcb, dhcp->p_out, IP_ADDR_BROADCAST, DHCP_SERVER_PORT, netif); |
| 847 | dhcp_delete_msg(dhcp); |
| 848 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_decline: BACKING OFF\n")); |
| 849 | } else { |
| 850 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, |
| 851 | ("dhcp_decline: could not allocate DHCP request\n")); |
| 852 | } |
| 853 | dhcp->tries++; |
| 854 | msecs = 10*1000; |
| 855 | dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS; |
| 856 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_decline(): set request timeout %"U16_F" msecs\n", msecs)); |
| 857 | return result; |
| 858 | } |
| 859 | #endif /* DHCP_DOES_ARP_CHECK */ |
| 860 | |
| 861 | |
| 862 | /** |
| 863 | * Start the DHCP process, discover a DHCP server. |
| 864 | * |
| 865 | * @param netif the netif under DHCP control |
| 866 | */ |
| 867 | static err_t |
| 868 | dhcp_discover(struct netif *netif) |
| 869 | { |
| 870 | struct dhcp *dhcp = netif->dhcp; |
| 871 | err_t result = ERR_OK; |
| 872 | u16_t msecs; |
| 873 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover()\n")); |
| 874 | ip_addr_set_any(&dhcp->offered_ip_addr); |
| 875 | dhcp_set_state(dhcp, DHCP_SELECTING); |
| 876 | /* create and initialize the DHCP message header */ |
| 877 | result = dhcp_create_msg(netif, dhcp, DHCP_DISCOVER); |
| 878 | if (result == ERR_OK) { |
| 879 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover: making request\n")); |
| 880 | |
| 881 | dhcp_option(dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN); |
| 882 | dhcp_option_short(dhcp, DHCP_MAX_MSG_LEN(netif)); |
| 883 | |
| 884 | dhcp_option(dhcp, DHCP_OPTION_PARAMETER_REQUEST_LIST, 4/*num options*/); |
| 885 | dhcp_option_byte(dhcp, DHCP_OPTION_SUBNET_MASK); |
| 886 | dhcp_option_byte(dhcp, DHCP_OPTION_ROUTER); |
| 887 | dhcp_option_byte(dhcp, DHCP_OPTION_BROADCAST); |
| 888 | dhcp_option_byte(dhcp, DHCP_OPTION_DNS_SERVER); |
| 889 | |
| 890 | dhcp_option_trailer(dhcp); |
| 891 | |
| 892 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover: realloc()ing\n")); |
| 893 | pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len); |
| 894 | |
| 895 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover: sendto(DISCOVER, IP_ADDR_BROADCAST, DHCP_SERVER_PORT)\n")); |
| 896 | udp_sendto_if(dhcp->pcb, dhcp->p_out, IP_ADDR_BROADCAST, DHCP_SERVER_PORT, netif); |
| 897 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover: deleting()ing\n")); |
| 898 | dhcp_delete_msg(dhcp); |
| 899 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_discover: SELECTING\n")); |
| 900 | } else { |
| 901 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_discover: could not allocate DHCP request\n")); |
| 902 | } |
| 903 | dhcp->tries++; |
| 904 | #if LWIP_DHCP_AUTOIP_COOP |
| 905 | if(dhcp->tries >= LWIP_DHCP_AUTOIP_COOP_TRIES && dhcp->autoip_coop_state == DHCP_AUTOIP_COOP_STATE_OFF) { |
| 906 | dhcp->autoip_coop_state = DHCP_AUTOIP_COOP_STATE_ON; |
| 907 | autoip_start(netif); |
| 908 | } |
| 909 | #endif /* LWIP_DHCP_AUTOIP_COOP */ |
| 910 | msecs = (dhcp->tries < 6 ? 1 << dhcp->tries : 60) * 1000; |
| 911 | dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS; |
| 912 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_discover(): set request timeout %"U16_F" msecs\n", msecs)); |
| 913 | return result; |
| 914 | } |
| 915 | |
| 916 | |
| 917 | /** |
| 918 | * Bind the interface to the offered IP address. |
| 919 | * |
| 920 | * @param netif network interface to bind to the offered address |
| 921 | */ |
| 922 | static void |
| 923 | dhcp_bind(struct netif *netif) |
| 924 | { |
| 925 | u32_t timeout; |
| 926 | struct dhcp *dhcp; |
| 927 | ip_addr_t sn_mask, gw_addr; |
| 928 | LWIP_ERROR("dhcp_bind: netif != NULL", (netif != NULL), return;); |
| 929 | dhcp = netif->dhcp; |
| 930 | LWIP_ERROR("dhcp_bind: dhcp != NULL", (dhcp != NULL), return;); |
| 931 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_bind(netif=%p) %c%c%"U16_F"\n", (void*)netif, netif->name[0], netif->name[1], (u16_t)netif->num)); |
| 932 | |
| 933 | /* temporary DHCP lease? */ |
| 934 | if (dhcp->offered_t1_renew != 0xffffffffUL) { |
| 935 | /* set renewal period timer */ |
| 936 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_bind(): t1 renewal timer %"U32_F" secs\n", dhcp->offered_t1_renew)); |
| 937 | timeout = (dhcp->offered_t1_renew + DHCP_COARSE_TIMER_SECS / 2) / DHCP_COARSE_TIMER_SECS; |
| 938 | if(timeout > 0xffff) { |
| 939 | timeout = 0xffff; |
| 940 | } |
| 941 | dhcp->t1_timeout = (u16_t)timeout; |
| 942 | if (dhcp->t1_timeout == 0) { |
| 943 | dhcp->t1_timeout = 1; |
| 944 | } |
| 945 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_bind(): set request timeout %"U32_F" msecs\n", dhcp->offered_t1_renew*1000)); |
| 946 | } |
| 947 | /* set renewal period timer */ |
| 948 | if (dhcp->offered_t2_rebind != 0xffffffffUL) { |
| 949 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_bind(): t2 rebind timer %"U32_F" secs\n", dhcp->offered_t2_rebind)); |
| 950 | timeout = (dhcp->offered_t2_rebind + DHCP_COARSE_TIMER_SECS / 2) / DHCP_COARSE_TIMER_SECS; |
| 951 | if(timeout > 0xffff) { |
| 952 | timeout = 0xffff; |
| 953 | } |
| 954 | dhcp->t2_timeout = (u16_t)timeout; |
| 955 | if (dhcp->t2_timeout == 0) { |
| 956 | dhcp->t2_timeout = 1; |
| 957 | } |
| 958 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_bind(): set request timeout %"U32_F" msecs\n", dhcp->offered_t2_rebind*1000)); |
| 959 | } |
| 960 | |
| 961 | if (dhcp->subnet_mask_given) { |
| 962 | /* copy offered network mask */ |
| 963 | ip_addr_copy(sn_mask, dhcp->offered_sn_mask); |
| 964 | } else { |
| 965 | /* subnet mask not given, choose a safe subnet mask given the network class */ |
| 966 | u8_t first_octet = ip4_addr1(&dhcp->offered_ip_addr); |
| 967 | if (first_octet <= 127) { |
| 968 | ip4_addr_set_u32(&sn_mask, PP_HTONL(0xff000000UL)); |
| 969 | } else if (first_octet >= 192) { |
| 970 | ip4_addr_set_u32(&sn_mask, PP_HTONL(0xffffff00UL)); |
| 971 | } else { |
| 972 | ip4_addr_set_u32(&sn_mask, PP_HTONL(0xffff0000UL)); |
| 973 | } |
| 974 | } |
| 975 | |
| 976 | ip_addr_copy(gw_addr, dhcp->offered_gw_addr); |
| 977 | /* gateway address not given? */ |
| 978 | if (ip_addr_isany(&gw_addr)) { |
| 979 | /* copy network address */ |
| 980 | ip_addr_get_network(&gw_addr, &dhcp->offered_ip_addr, &sn_mask); |
| 981 | /* use first host address on network as gateway */ |
| 982 | ip4_addr_set_u32(&gw_addr, ip4_addr_get_u32(&gw_addr) | PP_HTONL(0x00000001UL)); |
| 983 | } |
| 984 | |
| 985 | #if LWIP_DHCP_AUTOIP_COOP |
| 986 | if(dhcp->autoip_coop_state == DHCP_AUTOIP_COOP_STATE_ON) { |
| 987 | autoip_stop(netif); |
| 988 | dhcp->autoip_coop_state = DHCP_AUTOIP_COOP_STATE_OFF; |
| 989 | } |
| 990 | #endif /* LWIP_DHCP_AUTOIP_COOP */ |
| 991 | |
| 992 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_bind(): IP: 0x%08"X32_F"\n", |
| 993 | ip4_addr_get_u32(&dhcp->offered_ip_addr))); |
| 994 | netif_set_ipaddr(netif, &dhcp->offered_ip_addr); |
| 995 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_bind(): SN: 0x%08"X32_F"\n", |
| 996 | ip4_addr_get_u32(&sn_mask))); |
| 997 | netif_set_netmask(netif, &sn_mask); |
| 998 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_bind(): GW: 0x%08"X32_F"\n", |
| 999 | ip4_addr_get_u32(&gw_addr))); |
| 1000 | netif_set_gw(netif, &gw_addr); |
| 1001 | /* bring the interface up */ |
| 1002 | netif_set_up(netif); |
| 1003 | /* netif is now bound to DHCP leased address */ |
| 1004 | dhcp_set_state(dhcp, DHCP_BOUND); |
| 1005 | } |
| 1006 | |
| 1007 | /** |
| 1008 | * Renew an existing DHCP lease at the involved DHCP server. |
| 1009 | * |
| 1010 | * @param netif network interface which must renew its lease |
| 1011 | */ |
| 1012 | err_t |
| 1013 | dhcp_renew(struct netif *netif) |
| 1014 | { |
| 1015 | struct dhcp *dhcp = netif->dhcp; |
| 1016 | err_t result; |
| 1017 | u16_t msecs; |
| 1018 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_renew()\n")); |
| 1019 | dhcp_set_state(dhcp, DHCP_RENEWING); |
| 1020 | |
| 1021 | /* create and initialize the DHCP message header */ |
| 1022 | result = dhcp_create_msg(netif, dhcp, DHCP_REQUEST); |
| 1023 | if (result == ERR_OK) { |
| 1024 | dhcp_option(dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN); |
| 1025 | dhcp_option_short(dhcp, DHCP_MAX_MSG_LEN(netif)); |
| 1026 | |
| 1027 | #if LWIP_NETIF_HOSTNAME |
| 1028 | if (netif->hostname != NULL) { |
| 1029 | const char *p = (const char*)netif->hostname; |
| 1030 | u8_t namelen = (u8_t)strlen(p); |
| 1031 | if (namelen > 0) { |
| 1032 | LWIP_ASSERT("DHCP: hostname is too long!", namelen < 255); |
| 1033 | dhcp_option(dhcp, DHCP_OPTION_HOSTNAME, namelen); |
| 1034 | while (*p) { |
| 1035 | dhcp_option_byte(dhcp, *p++); |
| 1036 | } |
| 1037 | } |
| 1038 | } |
| 1039 | #endif /* LWIP_NETIF_HOSTNAME */ |
| 1040 | |
| 1041 | #if 0 |
| 1042 | dhcp_option(dhcp, DHCP_OPTION_REQUESTED_IP, 4); |
| 1043 | dhcp_option_long(dhcp, ntohl(dhcp->offered_ip_addr.addr)); |
| 1044 | #endif |
| 1045 | |
| 1046 | #if 0 |
| 1047 | dhcp_option(dhcp, DHCP_OPTION_SERVER_ID, 4); |
| 1048 | dhcp_option_long(dhcp, ntohl(dhcp->server_ip_addr.addr)); |
| 1049 | #endif |
| 1050 | /* append DHCP message trailer */ |
| 1051 | dhcp_option_trailer(dhcp); |
| 1052 | |
| 1053 | pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len); |
| 1054 | |
| 1055 | udp_sendto_if(dhcp->pcb, dhcp->p_out, &dhcp->server_ip_addr, DHCP_SERVER_PORT, netif); |
| 1056 | dhcp_delete_msg(dhcp); |
| 1057 | |
| 1058 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_renew: RENEWING\n")); |
| 1059 | } else { |
| 1060 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_renew: could not allocate DHCP request\n")); |
| 1061 | } |
| 1062 | dhcp->tries++; |
| 1063 | /* back-off on retries, but to a maximum of 20 seconds */ |
| 1064 | msecs = dhcp->tries < 10 ? dhcp->tries * 2000 : 20 * 1000; |
| 1065 | dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS; |
| 1066 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_renew(): set request timeout %"U16_F" msecs\n", msecs)); |
| 1067 | return result; |
| 1068 | } |
| 1069 | |
| 1070 | /** |
| 1071 | * Rebind with a DHCP server for an existing DHCP lease. |
| 1072 | * |
| 1073 | * @param netif network interface which must rebind with a DHCP server |
| 1074 | */ |
| 1075 | static err_t |
| 1076 | dhcp_rebind(struct netif *netif) |
| 1077 | { |
| 1078 | struct dhcp *dhcp = netif->dhcp; |
| 1079 | err_t result; |
| 1080 | u16_t msecs; |
| 1081 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_rebind()\n")); |
| 1082 | dhcp_set_state(dhcp, DHCP_REBINDING); |
| 1083 | |
| 1084 | /* create and initialize the DHCP message header */ |
| 1085 | result = dhcp_create_msg(netif, dhcp, DHCP_REQUEST); |
| 1086 | if (result == ERR_OK) { |
| 1087 | dhcp_option(dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN); |
| 1088 | dhcp_option_short(dhcp, DHCP_MAX_MSG_LEN(netif)); |
| 1089 | |
| 1090 | #if LWIP_NETIF_HOSTNAME |
| 1091 | if (netif->hostname != NULL) { |
| 1092 | const char *p = (const char*)netif->hostname; |
| 1093 | u8_t namelen = (u8_t)strlen(p); |
| 1094 | if (namelen > 0) { |
| 1095 | LWIP_ASSERT("DHCP: hostname is too long!", namelen < 255); |
| 1096 | dhcp_option(dhcp, DHCP_OPTION_HOSTNAME, namelen); |
| 1097 | while (*p) { |
| 1098 | dhcp_option_byte(dhcp, *p++); |
| 1099 | } |
| 1100 | } |
| 1101 | } |
| 1102 | #endif /* LWIP_NETIF_HOSTNAME */ |
| 1103 | |
| 1104 | #if 0 |
| 1105 | dhcp_option(dhcp, DHCP_OPTION_REQUESTED_IP, 4); |
| 1106 | dhcp_option_long(dhcp, ntohl(dhcp->offered_ip_addr.addr)); |
| 1107 | |
| 1108 | dhcp_option(dhcp, DHCP_OPTION_SERVER_ID, 4); |
| 1109 | dhcp_option_long(dhcp, ntohl(dhcp->server_ip_addr.addr)); |
| 1110 | #endif |
| 1111 | |
| 1112 | dhcp_option_trailer(dhcp); |
| 1113 | |
| 1114 | pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len); |
| 1115 | |
| 1116 | /* broadcast to server */ |
| 1117 | udp_sendto_if(dhcp->pcb, dhcp->p_out, IP_ADDR_BROADCAST, DHCP_SERVER_PORT, netif); |
| 1118 | dhcp_delete_msg(dhcp); |
| 1119 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_rebind: REBINDING\n")); |
| 1120 | } else { |
| 1121 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_rebind: could not allocate DHCP request\n")); |
| 1122 | } |
| 1123 | dhcp->tries++; |
| 1124 | msecs = dhcp->tries < 10 ? dhcp->tries * 1000 : 10 * 1000; |
| 1125 | dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS; |
| 1126 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_rebind(): set request timeout %"U16_F" msecs\n", msecs)); |
| 1127 | return result; |
| 1128 | } |
| 1129 | |
| 1130 | /** |
| 1131 | * Enter REBOOTING state to verify an existing lease |
| 1132 | * |
| 1133 | * @param netif network interface which must reboot |
| 1134 | */ |
| 1135 | static err_t |
| 1136 | dhcp_reboot(struct netif *netif) |
| 1137 | { |
| 1138 | struct dhcp *dhcp = netif->dhcp; |
| 1139 | err_t result; |
| 1140 | u16_t msecs; |
| 1141 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_reboot()\n")); |
| 1142 | dhcp_set_state(dhcp, DHCP_REBOOTING); |
| 1143 | |
| 1144 | /* create and initialize the DHCP message header */ |
| 1145 | result = dhcp_create_msg(netif, dhcp, DHCP_REQUEST); |
| 1146 | if (result == ERR_OK) { |
| 1147 | dhcp_option(dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN); |
| 1148 | dhcp_option_short(dhcp, 576); |
| 1149 | |
| 1150 | dhcp_option(dhcp, DHCP_OPTION_REQUESTED_IP, 4); |
| 1151 | dhcp_option_long(dhcp, ntohl(ip4_addr_get_u32(&dhcp->offered_ip_addr))); |
| 1152 | |
| 1153 | dhcp_option_trailer(dhcp); |
| 1154 | |
| 1155 | pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len); |
| 1156 | |
| 1157 | /* broadcast to server */ |
| 1158 | udp_sendto_if(dhcp->pcb, dhcp->p_out, IP_ADDR_BROADCAST, DHCP_SERVER_PORT, netif); |
| 1159 | dhcp_delete_msg(dhcp); |
| 1160 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_reboot: REBOOTING\n")); |
| 1161 | } else { |
| 1162 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_reboot: could not allocate DHCP request\n")); |
| 1163 | } |
| 1164 | dhcp->tries++; |
| 1165 | msecs = dhcp->tries < 10 ? dhcp->tries * 1000 : 10 * 1000; |
| 1166 | dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS; |
| 1167 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_reboot(): set request timeout %"U16_F" msecs\n", msecs)); |
| 1168 | return result; |
| 1169 | } |
| 1170 | |
| 1171 | |
| 1172 | /** |
| 1173 | * Release a DHCP lease. |
| 1174 | * |
| 1175 | * @param netif network interface which must release its lease |
| 1176 | */ |
| 1177 | err_t |
| 1178 | dhcp_release(struct netif *netif) |
| 1179 | { |
| 1180 | struct dhcp *dhcp = netif->dhcp; |
| 1181 | err_t result; |
| 1182 | u16_t msecs; |
| 1183 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_release()\n")); |
| 1184 | |
| 1185 | /* idle DHCP client */ |
| 1186 | dhcp_set_state(dhcp, DHCP_OFF); |
| 1187 | /* clean old DHCP offer */ |
| 1188 | ip_addr_set_zero(&dhcp->server_ip_addr); |
| 1189 | ip_addr_set_zero(&dhcp->offered_ip_addr); |
| 1190 | ip_addr_set_zero(&dhcp->offered_sn_mask); |
| 1191 | ip_addr_set_zero(&dhcp->offered_gw_addr); |
| 1192 | #if LWIP_DHCP_BOOTP_FILE |
| 1193 | ip_addr_set_zero(&dhcp->offered_si_addr); |
| 1194 | #endif /* LWIP_DHCP_BOOTP_FILE */ |
| 1195 | dhcp->offered_t0_lease = dhcp->offered_t1_renew = dhcp->offered_t2_rebind = 0; |
| 1196 | |
| 1197 | /* create and initialize the DHCP message header */ |
| 1198 | result = dhcp_create_msg(netif, dhcp, DHCP_RELEASE); |
| 1199 | if (result == ERR_OK) { |
| 1200 | dhcp_option_trailer(dhcp); |
| 1201 | |
| 1202 | pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len); |
| 1203 | |
| 1204 | udp_sendto_if(dhcp->pcb, dhcp->p_out, &dhcp->server_ip_addr, DHCP_SERVER_PORT, netif); |
| 1205 | dhcp_delete_msg(dhcp); |
| 1206 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_release: RELEASED, DHCP_OFF\n")); |
| 1207 | } else { |
| 1208 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_release: could not allocate DHCP request\n")); |
| 1209 | } |
| 1210 | dhcp->tries++; |
| 1211 | msecs = dhcp->tries < 10 ? dhcp->tries * 1000 : 10 * 1000; |
| 1212 | dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS; |
| 1213 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_release(): set request timeout %"U16_F" msecs\n", msecs)); |
| 1214 | /* bring the interface down */ |
| 1215 | netif_set_down(netif); |
| 1216 | /* remove IP address from interface */ |
| 1217 | netif_set_ipaddr(netif, IP_ADDR_ANY); |
| 1218 | netif_set_gw(netif, IP_ADDR_ANY); |
| 1219 | netif_set_netmask(netif, IP_ADDR_ANY); |
| 1220 | |
| 1221 | return result; |
| 1222 | } |
| 1223 | |
| 1224 | /** |
| 1225 | * Remove the DHCP client from the interface. |
| 1226 | * |
| 1227 | * @param netif The network interface to stop DHCP on |
| 1228 | */ |
| 1229 | void |
| 1230 | dhcp_stop(struct netif *netif) |
| 1231 | { |
| 1232 | struct dhcp *dhcp; |
| 1233 | LWIP_ERROR("dhcp_stop: netif != NULL", (netif != NULL), return;); |
| 1234 | dhcp = netif->dhcp; |
| 1235 | /* Remove the flag that says this netif is handled by DHCP. */ |
| 1236 | netif->flags &= ~NETIF_FLAG_DHCP; |
| 1237 | |
| 1238 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_stop()\n")); |
| 1239 | /* netif is DHCP configured? */ |
| 1240 | if (dhcp != NULL) { |
| 1241 | #if LWIP_DHCP_AUTOIP_COOP |
| 1242 | if(dhcp->autoip_coop_state == DHCP_AUTOIP_COOP_STATE_ON) { |
| 1243 | autoip_stop(netif); |
| 1244 | dhcp->autoip_coop_state = DHCP_AUTOIP_COOP_STATE_OFF; |
| 1245 | } |
| 1246 | #endif /* LWIP_DHCP_AUTOIP_COOP */ |
| 1247 | |
| 1248 | if (dhcp->pcb != NULL) { |
| 1249 | udp_remove(dhcp->pcb); |
| 1250 | dhcp->pcb = NULL; |
| 1251 | } |
| 1252 | LWIP_ASSERT("reply wasn't freed", dhcp->msg_in == NULL); |
| 1253 | dhcp_set_state(dhcp, DHCP_OFF); |
| 1254 | } |
| 1255 | } |
| 1256 | |
| 1257 | /* |
| 1258 | * Set the DHCP state of a DHCP client. |
| 1259 | * |
| 1260 | * If the state changed, reset the number of tries. |
| 1261 | */ |
| 1262 | static void |
| 1263 | dhcp_set_state(struct dhcp *dhcp, u8_t new_state) |
| 1264 | { |
| 1265 | if (new_state != dhcp->state) { |
| 1266 | dhcp->state = new_state; |
| 1267 | dhcp->tries = 0; |
| 1268 | dhcp->request_timeout = 0; |
| 1269 | } |
| 1270 | } |
| 1271 | |
| 1272 | /* |
| 1273 | * Concatenate an option type and length field to the outgoing |
| 1274 | * DHCP message. |
| 1275 | * |
| 1276 | */ |
| 1277 | static void |
| 1278 | dhcp_option(struct dhcp *dhcp, u8_t option_type, u8_t option_len) |
| 1279 | { |
| 1280 | LWIP_ASSERT("dhcp_option: dhcp->options_out_len + 2 + option_len <= DHCP_OPTIONS_LEN", dhcp->options_out_len + 2U + option_len <= DHCP_OPTIONS_LEN); |
| 1281 | dhcp->msg_out->options[dhcp->options_out_len++] = option_type; |
| 1282 | dhcp->msg_out->options[dhcp->options_out_len++] = option_len; |
| 1283 | } |
| 1284 | /* |
| 1285 | * Concatenate a single byte to the outgoing DHCP message. |
| 1286 | * |
| 1287 | */ |
| 1288 | static void |
| 1289 | dhcp_option_byte(struct dhcp *dhcp, u8_t value) |
| 1290 | { |
| 1291 | LWIP_ASSERT("dhcp_option_byte: dhcp->options_out_len < DHCP_OPTIONS_LEN", dhcp->options_out_len < DHCP_OPTIONS_LEN); |
| 1292 | dhcp->msg_out->options[dhcp->options_out_len++] = value; |
| 1293 | } |
| 1294 | |
| 1295 | static void |
| 1296 | dhcp_option_short(struct dhcp *dhcp, u16_t value) |
| 1297 | { |
| 1298 | LWIP_ASSERT("dhcp_option_short: dhcp->options_out_len + 2 <= DHCP_OPTIONS_LEN", dhcp->options_out_len + 2U <= DHCP_OPTIONS_LEN); |
| 1299 | dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t)((value & 0xff00U) >> 8); |
| 1300 | dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t) (value & 0x00ffU); |
| 1301 | } |
| 1302 | |
| 1303 | static void |
| 1304 | dhcp_option_long(struct dhcp *dhcp, u32_t value) |
| 1305 | { |
| 1306 | LWIP_ASSERT("dhcp_option_long: dhcp->options_out_len + 4 <= DHCP_OPTIONS_LEN", dhcp->options_out_len + 4U <= DHCP_OPTIONS_LEN); |
| 1307 | dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t)((value & 0xff000000UL) >> 24); |
| 1308 | dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t)((value & 0x00ff0000UL) >> 16); |
| 1309 | dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t)((value & 0x0000ff00UL) >> 8); |
| 1310 | dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t)((value & 0x000000ffUL)); |
| 1311 | } |
| 1312 | |
| 1313 | /** |
| 1314 | * Extract the DHCP message and the DHCP options. |
| 1315 | * |
| 1316 | * Extract the DHCP message and the DHCP options, each into a contiguous |
| 1317 | * piece of memory. As a DHCP message is variable sized by its options, |
| 1318 | * and also allows overriding some fields for options, the easy approach |
| 1319 | * is to first unfold the options into a conitguous piece of memory, and |
| 1320 | * use that further on. |
| 1321 | * |
| 1322 | */ |
| 1323 | static err_t |
| 1324 | dhcp_parse_reply(struct dhcp *dhcp, struct pbuf *p) |
| 1325 | { |
| 1326 | u8_t *options; |
| 1327 | u16_t offset; |
| 1328 | u16_t offset_max; |
| 1329 | u16_t options_idx; |
| 1330 | u16_t options_idx_max; |
| 1331 | struct pbuf *q; |
| 1332 | int parse_file_as_options = 0; |
| 1333 | int parse_sname_as_options = 0; |
| 1334 | |
| 1335 | /* clear received options */ |
| 1336 | dhcp_clear_all_options(dhcp); |
| 1337 | /* check that beginning of dhcp_msg (up to and including chaddr) is in first pbuf */ |
| 1338 | if (p->len < DHCP_SNAME_OFS) { |
| 1339 | return ERR_BUF; |
| 1340 | } |
| 1341 | dhcp->msg_in = (struct dhcp_msg *)p->payload; |
| 1342 | #if LWIP_DHCP_BOOTP_FILE |
| 1343 | /* clear boot file name */ |
| 1344 | dhcp->boot_file_name[0] = 0; |
| 1345 | #endif /* LWIP_DHCP_BOOTP_FILE */ |
| 1346 | |
| 1347 | /* parse options */ |
| 1348 | |
| 1349 | /* start with options field */ |
| 1350 | options_idx = DHCP_OPTIONS_OFS; |
| 1351 | /* parse options to the end of the received packet */ |
| 1352 | options_idx_max = p->tot_len; |
| 1353 | again: |
| 1354 | q = p; |
| 1355 | while((q != NULL) && (options_idx >= q->len)) { |
| 1356 | options_idx -= q->len; |
| 1357 | options_idx_max -= q->len; |
| 1358 | q = q->next; |
| 1359 | } |
| 1360 | if (q == NULL) { |
| 1361 | return ERR_BUF; |
| 1362 | } |
| 1363 | offset = options_idx; |
| 1364 | offset_max = options_idx_max; |
| 1365 | options = (u8_t*)q->payload; |
| 1366 | /* at least 1 byte to read and no end marker, then at least 3 bytes to read? */ |
| 1367 | while((q != NULL) && (options[offset] != DHCP_OPTION_END) && (offset < offset_max)) { |
| 1368 | u8_t op = options[offset]; |
| 1369 | u8_t len; |
| 1370 | u8_t decode_len = 0; |
| 1371 | int decode_idx = -1; |
| 1372 | u16_t val_offset = offset + 2; |
| 1373 | /* len byte might be in the next pbuf */ |
| 1374 | if (offset + 1 < q->len) { |
| 1375 | len = options[offset + 1]; |
| 1376 | } else { |
| 1377 | len = (q->next != NULL ? ((u8_t*)q->next->payload)[0] : 0); |
| 1378 | } |
| 1379 | /* LWIP_DEBUGF(DHCP_DEBUG, ("msg_offset=%"U16_F", q->len=%"U16_F, msg_offset, q->len)); */ |
| 1380 | decode_len = len; |
| 1381 | switch(op) { |
| 1382 | /* case(DHCP_OPTION_END): handled above */ |
| 1383 | case(DHCP_OPTION_PAD): |
| 1384 | /* special option: no len encoded */ |
| 1385 | decode_len = len = 0; |
| 1386 | /* will be increased below */ |
| 1387 | offset--; |
| 1388 | break; |
| 1389 | case(DHCP_OPTION_SUBNET_MASK): |
| 1390 | LWIP_ASSERT("len == 4", len == 4); |
| 1391 | decode_idx = DHCP_OPTION_IDX_SUBNET_MASK; |
| 1392 | break; |
| 1393 | case(DHCP_OPTION_ROUTER): |
| 1394 | decode_len = 4; /* only copy the first given router */ |
| 1395 | LWIP_ASSERT("len >= decode_len", len >= decode_len); |
| 1396 | decode_idx = DHCP_OPTION_IDX_ROUTER; |
| 1397 | break; |
| 1398 | case(DHCP_OPTION_DNS_SERVER): |
| 1399 | /* special case: there might be more than one server */ |
| 1400 | LWIP_ASSERT("len % 4 == 0", len % 4 == 0); |
| 1401 | /* limit number of DNS servers */ |
| 1402 | decode_len = LWIP_MIN(len, 4 * DNS_MAX_SERVERS); |
| 1403 | LWIP_ASSERT("len >= decode_len", len >= decode_len); |
| 1404 | decode_idx = DHCP_OPTION_IDX_DNS_SERVER; |
| 1405 | break; |
| 1406 | case(DHCP_OPTION_LEASE_TIME): |
| 1407 | LWIP_ASSERT("len == 4", len == 4); |
| 1408 | decode_idx = DHCP_OPTION_IDX_LEASE_TIME; |
| 1409 | break; |
| 1410 | case(DHCP_OPTION_OVERLOAD): |
| 1411 | LWIP_ASSERT("len == 1", len == 1); |
| 1412 | decode_idx = DHCP_OPTION_IDX_OVERLOAD; |
| 1413 | break; |
| 1414 | case(DHCP_OPTION_MESSAGE_TYPE): |
| 1415 | LWIP_ASSERT("len == 1", len == 1); |
| 1416 | decode_idx = DHCP_OPTION_IDX_MSG_TYPE; |
| 1417 | break; |
| 1418 | case(DHCP_OPTION_SERVER_ID): |
| 1419 | LWIP_ASSERT("len == 4", len == 4); |
| 1420 | decode_idx = DHCP_OPTION_IDX_SERVER_ID; |
| 1421 | break; |
| 1422 | case(DHCP_OPTION_T1): |
| 1423 | LWIP_ASSERT("len == 4", len == 4); |
| 1424 | decode_idx = DHCP_OPTION_IDX_T1; |
| 1425 | break; |
| 1426 | case(DHCP_OPTION_T2): |
| 1427 | LWIP_ASSERT("len == 4", len == 4); |
| 1428 | decode_idx = DHCP_OPTION_IDX_T2; |
| 1429 | break; |
| 1430 | default: |
| 1431 | decode_len = 0; |
| 1432 | LWIP_DEBUGF(DHCP_DEBUG, ("skipping option %"U16_F" in options\n", op)); |
| 1433 | break; |
| 1434 | } |
| 1435 | offset += len + 2; |
| 1436 | if (decode_len > 0) { |
| 1437 | u32_t value = 0; |
| 1438 | u16_t copy_len; |
| 1439 | decode_next: |
| 1440 | LWIP_ASSERT("check decode_idx", decode_idx >= 0 && decode_idx < DHCP_OPTION_IDX_MAX); |
| 1441 | LWIP_ASSERT("option already decoded", !dhcp_option_given(dhcp, decode_idx)); |
| 1442 | copy_len = LWIP_MIN(decode_len, 4); |
| 1443 | pbuf_copy_partial(q, &value, copy_len, val_offset); |
| 1444 | if (decode_len > 4) { |
| 1445 | /* decode more than one u32_t */ |
| 1446 | LWIP_ASSERT("decode_len % 4 == 0", decode_len % 4 == 0); |
| 1447 | dhcp_got_option(dhcp, decode_idx); |
| 1448 | dhcp_set_option_value(dhcp, decode_idx, htonl(value)); |
| 1449 | decode_len -= 4; |
| 1450 | val_offset += 4; |
| 1451 | decode_idx++; |
| 1452 | goto decode_next; |
| 1453 | } else if (decode_len == 4) { |
| 1454 | value = ntohl(value); |
| 1455 | } else { |
| 1456 | LWIP_ASSERT("invalid decode_len", decode_len == 1); |
| 1457 | value = ((u8_t*)&value)[0]; |
| 1458 | } |
| 1459 | dhcp_got_option(dhcp, decode_idx); |
| 1460 | dhcp_set_option_value(dhcp, decode_idx, value); |
| 1461 | } |
| 1462 | if (offset >= q->len) { |
| 1463 | offset -= q->len; |
| 1464 | offset_max -= q->len; |
| 1465 | q = q->next; |
| 1466 | options = (u8_t*)q->payload; |
| 1467 | } |
| 1468 | } |
| 1469 | /* is this an overloaded message? */ |
| 1470 | if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_OVERLOAD)) { |
| 1471 | u32_t overload = dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_OVERLOAD); |
| 1472 | dhcp_clear_option(dhcp, DHCP_OPTION_IDX_OVERLOAD); |
| 1473 | if (overload == DHCP_OVERLOAD_FILE) { |
| 1474 | parse_file_as_options = 1; |
| 1475 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("overloaded file field\n")); |
| 1476 | } else if (overload == DHCP_OVERLOAD_SNAME) { |
| 1477 | parse_sname_as_options = 1; |
| 1478 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("overloaded sname field\n")); |
| 1479 | } else if (overload == DHCP_OVERLOAD_SNAME_FILE) { |
| 1480 | parse_sname_as_options = 1; |
| 1481 | parse_file_as_options = 1; |
| 1482 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("overloaded sname and file field\n")); |
| 1483 | } else { |
| 1484 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("invalid overload option: %d\n", (int)overload)); |
| 1485 | } |
| 1486 | #if LWIP_DHCP_BOOTP_FILE |
| 1487 | if (!parse_file_as_options) { |
| 1488 | /* only do this for ACK messages */ |
| 1489 | if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_MSG_TYPE) && |
| 1490 | (dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_MSG_TYPE) == DHCP_ACK)) |
| 1491 | /* copy bootp file name, don't care for sname (server hostname) */ |
| 1492 | pbuf_copy_partial(p, dhcp->boot_file_name, DHCP_FILE_LEN-1, DHCP_FILE_OFS); |
| 1493 | /* make sure the string is really NULL-terminated */ |
| 1494 | dhcp->boot_file_name[DHCP_FILE_LEN-1] = 0; |
| 1495 | } |
| 1496 | #endif /* LWIP_DHCP_BOOTP_FILE */ |
| 1497 | } |
| 1498 | if (parse_file_as_options) { |
| 1499 | /* if both are overloaded, parse file first and then sname (RFC 2131 ch. 4.1) */ |
| 1500 | parse_file_as_options = 0; |
| 1501 | options_idx = DHCP_FILE_OFS; |
| 1502 | options_idx_max = DHCP_FILE_OFS + DHCP_FILE_LEN; |
| 1503 | goto again; |
| 1504 | } else if (parse_sname_as_options) { |
| 1505 | parse_sname_as_options = 0; |
| 1506 | options_idx = DHCP_SNAME_OFS; |
| 1507 | options_idx_max = DHCP_SNAME_OFS + DHCP_SNAME_LEN; |
| 1508 | goto again; |
| 1509 | } |
| 1510 | return ERR_OK; |
| 1511 | } |
| 1512 | |
| 1513 | /** |
| 1514 | * If an incoming DHCP message is in response to us, then trigger the state machine |
| 1515 | */ |
| 1516 | static void |
| 1517 | dhcp_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, ip_addr_t *addr, u16_t port) |
| 1518 | { |
| 1519 | struct netif *netif = (struct netif *)arg; |
| 1520 | struct dhcp *dhcp = netif->dhcp; |
| 1521 | struct dhcp_msg *reply_msg = (struct dhcp_msg *)p->payload; |
| 1522 | u8_t msg_type; |
| 1523 | u8_t i; |
| 1524 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_recv(pbuf = %p) from DHCP server %"U16_F".%"U16_F".%"U16_F".%"U16_F" port %"U16_F"\n", (void*)p, |
| 1525 | ip4_addr1_16(addr), ip4_addr2_16(addr), ip4_addr3_16(addr), ip4_addr4_16(addr), port)); |
| 1526 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("pbuf->len = %"U16_F"\n", p->len)); |
| 1527 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("pbuf->tot_len = %"U16_F"\n", p->tot_len)); |
| 1528 | /* prevent warnings about unused arguments */ |
| 1529 | LWIP_UNUSED_ARG(pcb); |
| 1530 | LWIP_UNUSED_ARG(addr); |
| 1531 | LWIP_UNUSED_ARG(port); |
| 1532 | |
| 1533 | LWIP_ASSERT("reply wasn't freed", dhcp->msg_in == NULL); |
| 1534 | |
| 1535 | if (p->len < DHCP_MIN_REPLY_LEN) { |
| 1536 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, ("DHCP reply message or pbuf too short\n")); |
| 1537 | goto free_pbuf_and_return; |
| 1538 | } |
| 1539 | |
| 1540 | if (reply_msg->op != DHCP_BOOTREPLY) { |
| 1541 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, ("not a DHCP reply message, but type %"U16_F"\n", (u16_t)reply_msg->op)); |
| 1542 | goto free_pbuf_and_return; |
| 1543 | } |
| 1544 | /* iterate through hardware address and match against DHCP message */ |
| 1545 | for (i = 0; i < netif->hwaddr_len; i++) { |
| 1546 | if (netif->hwaddr[i] != reply_msg->chaddr[i]) { |
| 1547 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, |
| 1548 | ("netif->hwaddr[%"U16_F"]==%02"X16_F" != reply_msg->chaddr[%"U16_F"]==%02"X16_F"\n", |
| 1549 | (u16_t)i, (u16_t)netif->hwaddr[i], (u16_t)i, (u16_t)reply_msg->chaddr[i])); |
| 1550 | goto free_pbuf_and_return; |
| 1551 | } |
| 1552 | } |
| 1553 | /* match transaction ID against what we expected */ |
| 1554 | if (ntohl(reply_msg->xid) != dhcp->xid) { |
| 1555 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, |
| 1556 | ("transaction id mismatch reply_msg->xid(%"X32_F")!=dhcp->xid(%"X32_F")\n",ntohl(reply_msg->xid),dhcp->xid)); |
| 1557 | goto free_pbuf_and_return; |
| 1558 | } |
| 1559 | /* option fields could be unfold? */ |
| 1560 | if (dhcp_parse_reply(dhcp, p) != ERR_OK) { |
| 1561 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, |
| 1562 | ("problem unfolding DHCP message - too short on memory?\n")); |
| 1563 | goto free_pbuf_and_return; |
| 1564 | } |
| 1565 | |
| 1566 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("searching DHCP_OPTION_MESSAGE_TYPE\n")); |
| 1567 | /* obtain pointer to DHCP message type */ |
| 1568 | if (!dhcp_option_given(dhcp, DHCP_OPTION_IDX_MSG_TYPE)) { |
| 1569 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, ("DHCP_OPTION_MESSAGE_TYPE option not found\n")); |
| 1570 | goto free_pbuf_and_return; |
| 1571 | } |
| 1572 | |
| 1573 | /* read DHCP message type */ |
| 1574 | msg_type = (u8_t)dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_MSG_TYPE); |
| 1575 | /* message type is DHCP ACK? */ |
| 1576 | if (msg_type == DHCP_ACK) { |
| 1577 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("DHCP_ACK received\n")); |
| 1578 | /* in requesting state? */ |
| 1579 | if (dhcp->state == DHCP_REQUESTING) { |
| 1580 | dhcp_handle_ack(netif); |
| 1581 | #if DHCP_DOES_ARP_CHECK |
| 1582 | /* check if the acknowledged lease address is already in use */ |
| 1583 | dhcp_check(netif); |
| 1584 | #else |
| 1585 | /* bind interface to the acknowledged lease address */ |
| 1586 | dhcp_bind(netif); |
| 1587 | #endif |
| 1588 | } |
| 1589 | /* already bound to the given lease address? */ |
| 1590 | else if ((dhcp->state == DHCP_REBOOTING) || (dhcp->state == DHCP_REBINDING) || (dhcp->state == DHCP_RENEWING)) { |
| 1591 | dhcp_bind(netif); |
| 1592 | } |
| 1593 | } |
| 1594 | /* received a DHCP_NAK in appropriate state? */ |
| 1595 | else if ((msg_type == DHCP_NAK) && |
| 1596 | ((dhcp->state == DHCP_REBOOTING) || (dhcp->state == DHCP_REQUESTING) || |
| 1597 | (dhcp->state == DHCP_REBINDING) || (dhcp->state == DHCP_RENEWING ))) { |
| 1598 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("DHCP_NAK received\n")); |
| 1599 | dhcp_handle_nak(netif); |
| 1600 | } |
| 1601 | /* received a DHCP_OFFER in DHCP_SELECTING state? */ |
| 1602 | else if ((msg_type == DHCP_OFFER) && (dhcp->state == DHCP_SELECTING)) { |
| 1603 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("DHCP_OFFER received in DHCP_SELECTING state\n")); |
| 1604 | dhcp->request_timeout = 0; |
| 1605 | /* remember offered lease */ |
| 1606 | dhcp_handle_offer(netif); |
| 1607 | } |
| 1608 | free_pbuf_and_return: |
| 1609 | dhcp->msg_in = NULL; |
| 1610 | pbuf_free(p); |
| 1611 | } |
| 1612 | |
| 1613 | /** |
| 1614 | * Create a DHCP request, fill in common headers |
| 1615 | * |
| 1616 | * @param netif the netif under DHCP control |
| 1617 | * @param dhcp dhcp control struct |
| 1618 | * @param message_type message type of the request |
| 1619 | */ |
| 1620 | static err_t |
| 1621 | dhcp_create_msg(struct netif *netif, struct dhcp *dhcp, u8_t message_type) |
| 1622 | { |
| 1623 | u16_t i; |
| 1624 | #ifndef DHCP_GLOBAL_XID |
| 1625 | /** default global transaction identifier starting value (easy to match |
| 1626 | * with a packet analyser). We simply increment for each new request. |
| 1627 | * Predefine DHCP_GLOBAL_XID to a better value or a function call to generate one |
| 1628 | * at runtime, any supporting function prototypes can be defined in DHCP_GLOBAL_XID_HEADER */ |
| 1629 | static u32_t xid = 0xABCD0000; |
| 1630 | #else |
| 1631 | static u32_t xid; |
| 1632 | static u8_t xid_initialised = 0; |
| 1633 | if (!xid_initialised) { |
| 1634 | xid = DHCP_GLOBAL_XID; |
| 1635 | xid_initialised = !xid_initialised; |
| 1636 | } |
| 1637 | #endif |
| 1638 | LWIP_ERROR("dhcp_create_msg: netif != NULL", (netif != NULL), return ERR_ARG;); |
| 1639 | LWIP_ERROR("dhcp_create_msg: dhcp != NULL", (dhcp != NULL), return ERR_VAL;); |
| 1640 | LWIP_ASSERT("dhcp_create_msg: dhcp->p_out == NULL", dhcp->p_out == NULL); |
| 1641 | LWIP_ASSERT("dhcp_create_msg: dhcp->msg_out == NULL", dhcp->msg_out == NULL); |
| 1642 | dhcp->p_out = pbuf_alloc(PBUF_TRANSPORT, sizeof(struct dhcp_msg), PBUF_RAM); |
| 1643 | if (dhcp->p_out == NULL) { |
| 1644 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, |
| 1645 | ("dhcp_create_msg(): could not allocate pbuf\n")); |
| 1646 | return ERR_MEM; |
| 1647 | } |
| 1648 | LWIP_ASSERT("dhcp_create_msg: check that first pbuf can hold struct dhcp_msg", |
| 1649 | (dhcp->p_out->len >= sizeof(struct dhcp_msg))); |
| 1650 | |
| 1651 | /* reuse transaction identifier in retransmissions */ |
| 1652 | if (dhcp->tries == 0) { |
| 1653 | xid++; |
| 1654 | } |
| 1655 | dhcp->xid = xid; |
| 1656 | LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, |
| 1657 | ("transaction id xid(%"X32_F")\n", xid)); |
| 1658 | |
| 1659 | dhcp->msg_out = (struct dhcp_msg *)dhcp->p_out->payload; |
| 1660 | |
| 1661 | dhcp->msg_out->op = DHCP_BOOTREQUEST; |
| 1662 | /* TODO: make link layer independent */ |
| 1663 | dhcp->msg_out->htype = DHCP_HTYPE_ETH; |
| 1664 | dhcp->msg_out->hlen = netif->hwaddr_len; |
| 1665 | dhcp->msg_out->hops = 0; |
| 1666 | dhcp->msg_out->xid = htonl(dhcp->xid); |
| 1667 | dhcp->msg_out->secs = 0; |
| 1668 | /* we don't need the broadcast flag since we can receive unicast traffic |
| 1669 | before being fully configured! */ |
| 1670 | dhcp->msg_out->flags = 0; |
| 1671 | ip_addr_set_zero(&dhcp->msg_out->ciaddr); |
| 1672 | /* set ciaddr to netif->ip_addr based on message_type and state */ |
| 1673 | if ((message_type == DHCP_INFORM) || (message_type == DHCP_DECLINE) || |
| 1674 | ((message_type == DHCP_REQUEST) && /* DHCP_BOUND not used for sending! */ |
| 1675 | ((dhcp->state==DHCP_RENEWING) || dhcp->state==DHCP_REBINDING))) { |
| 1676 | ip_addr_copy(dhcp->msg_out->ciaddr, netif->ip_addr); |
| 1677 | } |
| 1678 | ip_addr_set_zero(&dhcp->msg_out->yiaddr); |
| 1679 | ip_addr_set_zero(&dhcp->msg_out->siaddr); |
| 1680 | ip_addr_set_zero(&dhcp->msg_out->giaddr); |
| 1681 | for (i = 0; i < DHCP_CHADDR_LEN; i++) { |
| 1682 | /* copy netif hardware address, pad with zeroes */ |
| 1683 | dhcp->msg_out->chaddr[i] = (i < netif->hwaddr_len) ? netif->hwaddr[i] : 0/* pad byte*/; |
| 1684 | } |
| 1685 | for (i = 0; i < DHCP_SNAME_LEN; i++) { |
| 1686 | dhcp->msg_out->sname[i] = 0; |
| 1687 | } |
| 1688 | for (i = 0; i < DHCP_FILE_LEN; i++) { |
| 1689 | dhcp->msg_out->file[i] = 0; |
| 1690 | } |
| 1691 | dhcp->msg_out->cookie = PP_HTONL(DHCP_MAGIC_COOKIE); |
| 1692 | dhcp->options_out_len = 0; |
| 1693 | /* fill options field with an incrementing array (for debugging purposes) */ |
| 1694 | for (i = 0; i < DHCP_OPTIONS_LEN; i++) { |
| 1695 | dhcp->msg_out->options[i] = (u8_t)i; /* for debugging only, no matter if truncated */ |
| 1696 | } |
| 1697 | /* Add option MESSAGE_TYPE */ |
| 1698 | dhcp_option(dhcp, DHCP_OPTION_MESSAGE_TYPE, DHCP_OPTION_MESSAGE_TYPE_LEN); |
| 1699 | dhcp_option_byte(dhcp, message_type); |
| 1700 | return ERR_OK; |
| 1701 | } |
| 1702 | |
| 1703 | /** |
| 1704 | * Free previously allocated memory used to send a DHCP request. |
| 1705 | * |
| 1706 | * @param dhcp the dhcp struct to free the request from |
| 1707 | */ |
| 1708 | static void |
| 1709 | dhcp_delete_msg(struct dhcp *dhcp) |
| 1710 | { |
| 1711 | LWIP_ERROR("dhcp_delete_msg: dhcp != NULL", (dhcp != NULL), return;); |
| 1712 | LWIP_ASSERT("dhcp_delete_msg: dhcp->p_out != NULL", dhcp->p_out != NULL); |
| 1713 | LWIP_ASSERT("dhcp_delete_msg: dhcp->msg_out != NULL", dhcp->msg_out != NULL); |
| 1714 | if (dhcp->p_out != NULL) { |
| 1715 | pbuf_free(dhcp->p_out); |
| 1716 | } |
| 1717 | dhcp->p_out = NULL; |
| 1718 | dhcp->msg_out = NULL; |
| 1719 | } |
| 1720 | |
| 1721 | /** |
| 1722 | * Add a DHCP message trailer |
| 1723 | * |
| 1724 | * Adds the END option to the DHCP message, and if |
| 1725 | * necessary, up to three padding bytes. |
| 1726 | * |
| 1727 | * @param dhcp DHCP state structure |
| 1728 | */ |
| 1729 | static void |
| 1730 | dhcp_option_trailer(struct dhcp *dhcp) |
| 1731 | { |
| 1732 | LWIP_ERROR("dhcp_option_trailer: dhcp != NULL", (dhcp != NULL), return;); |
| 1733 | LWIP_ASSERT("dhcp_option_trailer: dhcp->msg_out != NULL\n", dhcp->msg_out != NULL); |
| 1734 | LWIP_ASSERT("dhcp_option_trailer: dhcp->options_out_len < DHCP_OPTIONS_LEN\n", dhcp->options_out_len < DHCP_OPTIONS_LEN); |
| 1735 | dhcp->msg_out->options[dhcp->options_out_len++] = DHCP_OPTION_END; |
| 1736 | /* packet is too small, or not 4 byte aligned? */ |
| 1737 | while ((dhcp->options_out_len < DHCP_MIN_OPTIONS_LEN) || (dhcp->options_out_len & 3)) { |
| 1738 | /* 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)); */ |
| 1739 | LWIP_ASSERT("dhcp_option_trailer: dhcp->options_out_len < DHCP_OPTIONS_LEN\n", dhcp->options_out_len < DHCP_OPTIONS_LEN); |
| 1740 | /* add a fill/padding byte */ |
| 1741 | dhcp->msg_out->options[dhcp->options_out_len++] = 0; |
| 1742 | } |
| 1743 | } |
| 1744 | |
| 1745 | #endif /* LWIP_DHCP */ |