uIP 1.0: dhcpc.c

00001 /*
+00002  * Copyright (c) 2005, Swedish Institute of Computer Science
+00003  * All rights reserved.
+00004  *
+00005  * Redistribution and use in source and binary forms, with or without
+00006  * modification, are permitted provided that the following conditions
+00007  * are met:
+00008  * 1. Redistributions of source code must retain the above copyright
+00009  *    notice, this list of conditions and the following disclaimer.
+00010  * 2. Redistributions in binary form must reproduce the above copyright
+00011  *    notice, this list of conditions and the following disclaimer in the
+00012  *    documentation and/or other materials provided with the distribution.
+00013  * 3. Neither the name of the Institute nor the names of its contributors
+00014  *    may be used to endorse or promote products derived from this software
+00015  *    without specific prior written permission.
+00016  *
+00017  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
+00018  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+00019  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+00020  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
+00021  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+00022  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+00023  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+00024  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+00025  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+00026  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+00027  * SUCH DAMAGE.
+00028  *
+00029  * This file is part of the uIP TCP/IP stack
+00030  *
+00031  * @(#)$Id: dhcpc.c,v 1.2 2006/06/11 21:46:37 adam Exp $
+00032  */
+00033 
+00034 #include <stdio.h>
+00035 #include <string.h>
+00036 
+00037 #include "uip.h"
+00038 #include "dhcpc.h"
+00039 #include "timer.h"
+00040 #include "pt.h"
+00041 
+00042 #define STATE_INITIAL         0
+00043 #define STATE_SENDING         1
+00044 #define STATE_OFFER_RECEIVED  2
+00045 #define STATE_CONFIG_RECEIVED 3
+00046 
+00047 static struct dhcpc_state s;
+00048 
+00049 struct dhcp_msg {
+00050   u8_t op, htype, hlen, hops;
+00051   u8_t xid[4];
+00052   u16_t secs, flags;
+00053   u8_t ciaddr[4];
+00054   u8_t yiaddr[4];
+00055   u8_t siaddr[4];
+00056   u8_t giaddr[4];
+00057   u8_t chaddr[16];
+00058 #ifndef UIP_CONF_DHCP_LIGHT
+00059   u8_t sname[64];
+00060   u8_t file[128];
+00061 #endif
+00062   u8_t options[312];
+00063 };
+00064 
+00065 #define BOOTP_BROADCAST 0x8000
+00066 
+00067 #define DHCP_REQUEST        1
+00068 #define DHCP_REPLY          2
+00069 #define DHCP_HTYPE_ETHERNET 1
+00070 #define DHCP_HLEN_ETHERNET  6
+00071 #define DHCP_MSG_LEN      236
+00072 
+00073 #define DHCPC_SERVER_PORT  67
+00074 #define DHCPC_CLIENT_PORT  68
+00075 
+00076 #define DHCPDISCOVER  1
+00077 #define DHCPOFFER     2
+00078 #define DHCPREQUEST   3
+00079 #define DHCPDECLINE   4
+00080 #define DHCPACK       5
+00081 #define DHCPNAK       6
+00082 #define DHCPRELEASE   7
+00083 
+00084 #define DHCP_OPTION_SUBNET_MASK   1
+00085 #define DHCP_OPTION_ROUTER        3
+00086 #define DHCP_OPTION_DNS_SERVER    6
+00087 #define DHCP_OPTION_REQ_IPADDR   50
+00088 #define DHCP_OPTION_LEASE_TIME   51
+00089 #define DHCP_OPTION_MSG_TYPE     53
+00090 #define DHCP_OPTION_SERVER_ID    54
+00091 #define DHCP_OPTION_REQ_LIST     55
+00092 #define DHCP_OPTION_END         255
+00093 
+00094 static const u8_t xid[4] = {0xad, 0xde, 0x12, 0x23};
+00095 static const u8_t magic_cookie[4] = {99, 130, 83, 99};
+00096 /*---------------------------------------------------------------------------*/
+00097 static u8_t *
+00098 add_msg_type(u8_t *optptr, u8_t type)
+00099 {
+00100   *optptr++ = DHCP_OPTION_MSG_TYPE;
+00101   *optptr++ = 1;
+00102   *optptr++ = type;
+00103   return optptr;
+00104 }
+00105 /*---------------------------------------------------------------------------*/
+00106 static u8_t *
+00107 add_server_id(u8_t *optptr)
+00108 {
+00109   *optptr++ = DHCP_OPTION_SERVER_ID;
+00110   *optptr++ = 4;
+00111   memcpy(optptr, s.serverid, 4);
+00112   return optptr + 4;
+00113 }
+00114 /*---------------------------------------------------------------------------*/
+00115 static u8_t *
+00116 add_req_ipaddr(u8_t *optptr)
+00117 {
+00118   *optptr++ = DHCP_OPTION_REQ_IPADDR;
+00119   *optptr++ = 4;
+00120   memcpy(optptr, s.ipaddr, 4);
+00121   return optptr + 4;
+00122 }
+00123 /*---------------------------------------------------------------------------*/
+00124 static u8_t *
+00125 add_req_options(u8_t *optptr)
+00126 {
+00127   *optptr++ = DHCP_OPTION_REQ_LIST;
+00128   *optptr++ = 3;
+00129   *optptr++ = DHCP_OPTION_SUBNET_MASK;
+00130   *optptr++ = DHCP_OPTION_ROUTER;
+00131   *optptr++ = DHCP_OPTION_DNS_SERVER;
+00132   return optptr;
+00133 }
+00134 /*---------------------------------------------------------------------------*/
+00135 static u8_t *
+00136 add_end(u8_t *optptr)
+00137 {
+00138   *optptr++ = DHCP_OPTION_END;
+00139   return optptr;
+00140 }
+00141 /*---------------------------------------------------------------------------*/
+00142 static void
+00143 create_msg(register struct dhcp_msg *m)
+00144 {
+00145   m->op = DHCP_REQUEST;
+00146   m->htype = DHCP_HTYPE_ETHERNET;
+00147   m->hlen = s.mac_len;
+00148   m->hops = 0;
+00149   memcpy(m->xid, xid, sizeof(m->xid));
+00150   m->secs = 0;
+00151   m->flags = HTONS(BOOTP_BROADCAST); /*  Broadcast bit. */
+00152   /*  uip_ipaddr_copy(m->ciaddr, uip_hostaddr);*/
+00153   memcpy(m->ciaddr, uip_hostaddr, sizeof(m->ciaddr));
+00154   memset(m->yiaddr, 0, sizeof(m->yiaddr));
+00155   memset(m->siaddr, 0, sizeof(m->siaddr));
+00156   memset(m->giaddr, 0, sizeof(m->giaddr));
+00157   memcpy(m->chaddr, s.mac_addr, s.mac_len);
+00158   memset(&m->chaddr[s.mac_len], 0, sizeof(m->chaddr) - s.mac_len);
+00159 #ifndef UIP_CONF_DHCP_LIGHT
+00160   memset(m->sname, 0, sizeof(m->sname));
+00161   memset(m->file, 0, sizeof(m->file));
+00162 #endif
+00163 
+00164   memcpy(m->options, magic_cookie, sizeof(magic_cookie));
+00165 }
+00166 /*---------------------------------------------------------------------------*/
+00167 static void
+00168 send_discover(void)
+00169 {
+00170   u8_t *end;
+00171   struct dhcp_msg *m = (struct dhcp_msg *)uip_appdata;
+00172 
+00173   create_msg(m);
+00174 
+00175   end = add_msg_type(&m->options[4], DHCPDISCOVER);
+00176   end = add_req_options(end);
+00177   end = add_end(end);
+00178 
+00179   uip_send(uip_appdata, end - (u8_t *)uip_appdata);
+00180 }
+00181 /*---------------------------------------------------------------------------*/
+00182 static void
+00183 send_request(void)
+00184 {
+00185   u8_t *end;
+00186   struct dhcp_msg *m = (struct dhcp_msg *)uip_appdata;
+00187 
+00188   create_msg(m);
+00189   
+00190   end = add_msg_type(&m->options[4], DHCPREQUEST);
+00191   end = add_server_id(end);
+00192   end = add_req_ipaddr(end);
+00193   end = add_end(end);
+00194   
+00195   uip_send(uip_appdata, end - (u8_t *)uip_appdata);
+00196 }
+00197 /*---------------------------------------------------------------------------*/
+00198 static u8_t
+00199 parse_options(u8_t *optptr, int len)
+00200 {
+00201   u8_t *end = optptr + len;
+00202   u8_t type = 0;
+00203 
+00204   while(optptr < end) {
+00205     switch(*optptr) {
+00206     case DHCP_OPTION_SUBNET_MASK:
+00207       memcpy(s.netmask, optptr + 2, 4);
+00208       break;
+00209     case DHCP_OPTION_ROUTER:
+00210       memcpy(s.default_router, optptr + 2, 4);
+00211       break;
+00212     case DHCP_OPTION_DNS_SERVER:
+00213       memcpy(s.dnsaddr, optptr + 2, 4);
+00214       break;
+00215     case DHCP_OPTION_MSG_TYPE:
+00216       type = *(optptr + 2);
+00217       break;
+00218     case DHCP_OPTION_SERVER_ID:
+00219       memcpy(s.serverid, optptr + 2, 4);
+00220       break;
+00221     case DHCP_OPTION_LEASE_TIME:
+00222       memcpy(s.lease_time, optptr + 2, 4);
+00223       break;
+00224     case DHCP_OPTION_END:
+00225       return type;
+00226     }
+00227 
+00228     optptr += optptr[1] + 2;
+00229   }
+00230   return type;
+00231 }
+00232 /*---------------------------------------------------------------------------*/
+00233 static u8_t
+00234 parse_msg(void)
+00235 {
+00236   struct dhcp_msg *m = (struct dhcp_msg *)uip_appdata;
+00237   
+00238   if(m->op == DHCP_REPLY &&
+00239      memcmp(m->xid, xid, sizeof(xid)) == 0 &&
+00240      memcmp(m->chaddr, s.mac_addr, s.mac_len) == 0) {
+00241     memcpy(s.ipaddr, m->yiaddr, 4);
+00242     return parse_options(&m->options[4], uip_datalen());
+00243   }
+00244   return 0;
+00245 }
+00246 /*---------------------------------------------------------------------------*/
+00247 static
+00248 PT_THREAD(handle_dhcp(void))
+00249 {
+00250   PT_BEGIN(&s.pt);
+00251   
+00252   /* try_again:*/
+00253   s.state = STATE_SENDING;
+00254   s.ticks = CLOCK_SECOND;
+00255 
+00256   do {
+00257     send_discover();
+00258     timer_set(&s.timer, s.ticks);
+00259     PT_WAIT_UNTIL(&s.pt, uip_newdata() || timer_expired(&s.timer));
+00260 
+00261     if(uip_newdata() && parse_msg() == DHCPOFFER) {
+00262       s.state = STATE_OFFER_RECEIVED;
+00263       break;
+00264     }
+00265 
+00266     if(s.ticks < CLOCK_SECOND * 60) {
+00267       s.ticks *= 2;
+00268     }
+00269   } while(s.state != STATE_OFFER_RECEIVED);
+00270   
+00271   s.ticks = CLOCK_SECOND;
+00272 
+00273   do {
+00274     send_request();
+00275     timer_set(&s.timer, s.ticks);
+00276     PT_WAIT_UNTIL(&s.pt, uip_newdata() || timer_expired(&s.timer));
+00277 
+00278     if(uip_newdata() && parse_msg() == DHCPACK) {
+00279       s.state = STATE_CONFIG_RECEIVED;
+00280       break;
+00281     }
+00282 
+00283     if(s.ticks <= CLOCK_SECOND * 10) {
+00284       s.ticks += CLOCK_SECOND;
+00285     } else {
+00286       PT_RESTART(&s.pt);
+00287     }
+00288   } while(s.state != STATE_CONFIG_RECEIVED);
+00289   
+00290 #if 0
+00291   printf("Got IP address %d.%d.%d.%d\n",
+00292          uip_ipaddr1(s.ipaddr), uip_ipaddr2(s.ipaddr),
+00293          uip_ipaddr3(s.ipaddr), uip_ipaddr4(s.ipaddr));
+00294   printf("Got netmask %d.%d.%d.%d\n",
+00295          uip_ipaddr1(s.netmask), uip_ipaddr2(s.netmask),
+00296          uip_ipaddr3(s.netmask), uip_ipaddr4(s.netmask));
+00297   printf("Got DNS server %d.%d.%d.%d\n",
+00298          uip_ipaddr1(s.dnsaddr), uip_ipaddr2(s.dnsaddr),
+00299          uip_ipaddr3(s.dnsaddr), uip_ipaddr4(s.dnsaddr));
+00300   printf("Got default router %d.%d.%d.%d\n",
+00301          uip_ipaddr1(s.default_router), uip_ipaddr2(s.default_router),
+00302          uip_ipaddr3(s.default_router), uip_ipaddr4(s.default_router));
+00303   printf("Lease expires in %ld seconds\n",
+00304          ntohs(s.lease_time[0])*65536ul + ntohs(s.lease_time[1]));
+00305 #endif
+00306 
+00307   dhcpc_configured(&s);
+00308   
+00309   /*  timer_stop(&s.timer);*/
+00310 
+00311   /*
+00312    * PT_END restarts the thread so we do this instead. Eventually we
+00313    * should reacquire expired leases here.
+00314    */
+00315   while(1) {
+00316     PT_YIELD(&s.pt);
+00317   }
+00318 
+00319   PT_END(&s.pt);
+00320 }
+00321 /*---------------------------------------------------------------------------*/
+00322 void
+00323 dhcpc_init(const void *mac_addr, int mac_len)
+00324 {
+00325   uip_ipaddr_t addr;
+00326   
+00327   s.mac_addr = mac_addr;
+00328   s.mac_len  = mac_len;
+00329 
+00330   s.state = STATE_INITIAL;
+00331   uip_ipaddr(addr, 255,255,255,255);
+00332   s.conn = uip_udp_new(&addr, HTONS(DHCPC_SERVER_PORT));
+00333   if(s.conn != NULL) {
+00334     uip_udp_bind(s.conn, HTONS(DHCPC_CLIENT_PORT));
+00335   }
+00336   PT_INIT(&s.pt);
+00337 }
+00338 /*---------------------------------------------------------------------------*/
+00339 void
+00340 dhcpc_appcall(void)
+00341 {
+00342   handle_dhcp();
+00343 }
+00344 /*---------------------------------------------------------------------------*/
+00345 void
+00346 dhcpc_request(void)
+00347 {
+00348   u16_t ipaddr[2];
+00349   
+00350   if(s.state == STATE_INITIAL) {
+00351     uip_ipaddr(ipaddr, 0,0,0,0);
+00352     uip_sethostaddr(ipaddr);
+00353     /*    handle_dhcp(PROCESS_EVENT_NONE, NULL);*/
+00354   }
+00355 }
+00356 /*---------------------------------------------------------------------------*/
+