/*
* Copyright (c) 2005, Swedish Institute of Computer Science
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* This file is part of the Contiki operating system.
*
* @(#)$Id: dhcpc.c,v 1.2 2006/06/24 17:59:28 gpz Exp $
*/
#include <stdio.h>
#include <string.h>
#include "contiki.h"
#include "contiki-net.h"
#include "net/dhcpc.h"
#define STATE_INITIAL 0
#define STATE_SENDING 1
#define STATE_OFFER_RECEIVED 2
#define STATE_CONFIG_RECEIVED 3
static struct dhcpc_state s;
struct dhcp_msg {
u8_t op, htype, hlen, hops;
u8_t xid[4];
u16_t secs, flags;
u8_t ciaddr[4];
u8_t yiaddr[4];
u8_t siaddr[4];
u8_t giaddr[4];
u8_t chaddr[16];
#ifndef UIP_CONF_DHCP_LIGHT
u8_t sname[64];
u8_t file[128];
#endif
u8_t options[312];
};
#define BOOTP_BROADCAST 0x8000
#define DHCP_REQUEST 1
#define DHCP_REPLY 2
#define DHCP_HTYPE_ETHERNET 1
#define DHCP_HLEN_ETHERNET 6
#define DHCP_MSG_LEN 236
#define DHCPC_SERVER_PORT 67
#define DHCPC_CLIENT_PORT 68
#define DHCPDISCOVER 1
#define DHCPOFFER 2
#define DHCPREQUEST 3
#define DHCPDECLINE 4
#define DHCPACK 5
#define DHCPNAK 6
#define DHCPRELEASE 7
#define DHCP_OPTION_SUBNET_MASK 1
#define DHCP_OPTION_ROUTER 3
#define DHCP_OPTION_DNS_SERVER 6
#define DHCP_OPTION_REQ_IPADDR 50
#define DHCP_OPTION_LEASE_TIME 51
#define DHCP_OPTION_MSG_TYPE 53
#define DHCP_OPTION_SERVER_ID 54
#define DHCP_OPTION_REQ_LIST 55
#define DHCP_OPTION_END 255
static u32_t xid;
static const u8_t magic_cookie[4] = {99, 130, 83, 99};
/*---------------------------------------------------------------------------*/
static u8_t *
add_msg_type(u8_t *optptr, u8_t type)
{
*optptr++ = DHCP_OPTION_MSG_TYPE;
*optptr++ = 1;
*optptr++ = type;
return optptr;
}
/*---------------------------------------------------------------------------*/
static u8_t *
add_server_id(u8_t *optptr)
{
*optptr++ = DHCP_OPTION_SERVER_ID;
*optptr++ = 4;
memcpy(optptr, s.serverid, 4);
return optptr + 4;
}
/*---------------------------------------------------------------------------*/
static u8_t *
add_req_ipaddr(u8_t *optptr)
{
*optptr++ = DHCP_OPTION_REQ_IPADDR;
*optptr++ = 4;
memcpy(optptr, s.ipaddr, 4);
return optptr + 4;
}
/*---------------------------------------------------------------------------*/
static u8_t *
add_req_options(u8_t *optptr)
{
*optptr++ = DHCP_OPTION_REQ_LIST;
*optptr++ = 3;
*optptr++ = DHCP_OPTION_SUBNET_MASK;
*optptr++ = DHCP_OPTION_ROUTER;
*optptr++ = DHCP_OPTION_DNS_SERVER;
return optptr;
}
/*---------------------------------------------------------------------------*/
static u8_t *
add_end(u8_t *optptr)
{
*optptr++ = DHCP_OPTION_END;
return optptr;
}
/*---------------------------------------------------------------------------*/
static void
create_msg(register struct dhcp_msg *m)
{
m->op = DHCP_REQUEST;
m->htype = DHCP_HTYPE_ETHERNET;
m->hlen = s.mac_len;
m->hops = 0;
memcpy(m->xid, &xid, sizeof(m->xid));
m->secs = 0;
m->flags = HTONS(BOOTP_BROADCAST); /* Broadcast bit. */
/* uip_ipaddr_copy(m->ciaddr, uip_hostaddr);*/
memcpy(m->ciaddr, uip_hostaddr, sizeof(m->ciaddr));
memset(m->yiaddr, 0, sizeof(m->yiaddr));
memset(m->siaddr, 0, sizeof(m->siaddr));
memset(m->giaddr, 0, sizeof(m->giaddr));
memcpy(m->chaddr, s.mac_addr, s.mac_len);
memset(&m->chaddr[s.mac_len], 0, sizeof(m->chaddr) - s.mac_len);
#ifndef UIP_CONF_DHCP_LIGHT
memset(m->sname, 0, sizeof(m->sname));
memset(m->file, 0, sizeof(m->file));
#endif
memcpy(m->options, magic_cookie, sizeof(magic_cookie));
}
/*---------------------------------------------------------------------------*/
static void
send_discover(void)
{
u8_t *end;
struct dhcp_msg *m = (struct dhcp_msg *)uip_appdata;
create_msg(m);
end = add_msg_type(&m->options[4], DHCPDISCOVER);
end = add_req_options(end);
end = add_end(end);
uip_send(uip_appdata, end - (u8_t *)uip_appdata);
}
/*---------------------------------------------------------------------------*/
static void
send_request(void)
{
u8_t *end;
struct dhcp_msg *m = (struct dhcp_msg *)uip_appdata;
create_msg(m);
end = add_msg_type(&m->options[4], DHCPREQUEST);
end = add_server_id(end);
end = add_req_ipaddr(end);
end = add_end(end);
uip_send(uip_appdata, end - (u8_t *)uip_appdata);
}
/*---------------------------------------------------------------------------*/
static u8_t
parse_options(u8_t *optptr, int len)
{
u8_t *end = optptr + len;
u8_t type = 0;
while(optptr < end) {
switch(*optptr) {
case DHCP_OPTION_SUBNET_MASK:
memcpy(s.netmask, optptr + 2, 4);
break;
case DHCP_OPTION_ROUTER:
memcpy(s.default_router, optptr + 2, 4);
break;
case DHCP_OPTION_DNS_SERVER:
memcpy(s.dnsaddr, optptr + 2, 4);
break;
case DHCP_OPTION_MSG_TYPE:
type = *(optptr + 2);
break;
case DHCP_OPTION_SERVER_ID:
memcpy(s.serverid, optptr + 2, 4);
break;
case DHCP_OPTION_LEASE_TIME:
memcpy(s.lease_time, optptr + 2, 4);
break;
case DHCP_OPTION_END:
return type;
}
optptr += optptr[1] + 2;
}
return type;
}
/*---------------------------------------------------------------------------*/
static u8_t
parse_msg(void)
{
struct dhcp_msg *m = (struct dhcp_msg *)uip_appdata;
if(m->op == DHCP_REPLY &&
memcmp(m->xid, &xid, sizeof(xid)) == 0 &&
memcmp(m->chaddr, s.mac_addr, s.mac_len) == 0) {
memcpy(s.ipaddr, m->yiaddr, 4);
return parse_options(&m->options[4], uip_datalen());
}
return 0;
}
/*---------------------------------------------------------------------------*/
/*
* Is this a "fresh" reply for me? If it is, return the type.
*/
static int
msg_for_me(void)
{
struct dhcp_msg *m = (struct dhcp_msg *)uip_appdata;
u8_t *optptr = &m->options[4];
u8_t *end = (u8_t*)uip_appdata + uip_datalen();
if(m->op == DHCP_REPLY &&
memcmp(m->xid, &xid, sizeof(xid)) == 0 &&
memcmp(m->chaddr, s.mac_addr, s.mac_len) == 0) {
while(optptr < end) {
if(*optptr == DHCP_OPTION_MSG_TYPE) {
return *(optptr + 2);
} else if (*optptr == DHCP_OPTION_END) {
return -1;
}
optptr += optptr[1] + 2;
}
}
return -1;
}
/*---------------------------------------------------------------------------*/
static
PT_THREAD(handle_dhcp(process_event_t ev, void *data))
{
PT_BEGIN(&s.pt);
init:
xid++;
s.state = STATE_SENDING;
s.ticks = CLOCK_SECOND;
while (1) {
while(ev != tcpip_event) {
tcpip_poll_udp(s.conn);
PT_YIELD(&s.pt);
}
send_discover();
etimer_set(&s.etimer, s.ticks);
do {
PT_YIELD(&s.pt);
if(ev == tcpip_event && uip_newdata() && msg_for_me() == DHCPOFFER) {
parse_msg();
s.state = STATE_OFFER_RECEIVED;
goto selecting;
}
} while (!etimer_expired(&s.etimer));
if(s.ticks < CLOCK_SECOND * 60) {
s.ticks *= 2;
}
}
selecting:
xid++;
s.ticks = CLOCK_SECOND;
do {
while(ev != tcpip_event) {
tcpip_poll_udp(s.conn);
PT_YIELD(&s.pt);
}
send_request();
etimer_set(&s.etimer, s.ticks);
do {
PT_YIELD(&s.pt);
if(ev == tcpip_event && uip_newdata() && msg_for_me() == DHCPACK) {
parse_msg();
s.state = STATE_CONFIG_RECEIVED;
goto bound;
}
} while (!etimer_expired(&s.etimer));
if(s.ticks <= CLOCK_SECOND * 10) {
s.ticks += CLOCK_SECOND;
} else {
goto init;
}
} while(s.state != STATE_CONFIG_RECEIVED);
bound:
#if 0
printf("Got IP address %d.%d.%d.%d\n",
uip_ipaddr1(s.ipaddr), uip_ipaddr2(s.ipaddr),
uip_ipaddr3(s.ipaddr), uip_ipaddr4(s.ipaddr));
printf("Got netmask %d.%d.%d.%d\n",
uip_ipaddr1(s.netmask), uip_ipaddr2(s.netmask),
uip_ipaddr3(s.netmask), uip_ipaddr4(s.netmask));
printf("Got DNS server %d.%d.%d.%d\n",
uip_ipaddr1(s.dnsaddr), uip_ipaddr2(s.dnsaddr),
uip_ipaddr3(s.dnsaddr), uip_ipaddr4(s.dnsaddr));
printf("Got default router %d.%d.%d.%d\n",
uip_ipaddr1(s.default_router), uip_ipaddr2(s.default_router),
uip_ipaddr3(s.default_router), uip_ipaddr4(s.default_router));
printf("Lease expires in %ld seconds\n",
ntohs(s.lease_time[0])*65536ul + ntohs(s.lease_time[1]));
#endif
dhcpc_configured(&s);
if((s.lease_time[0]*65536ul + ntohs(s.lease_time[1]))*CLOCK_SECOND/2
<= (clock_time_t)~0ul) {
s.ticks = (s.lease_time[0]*65536ul +ntohs(s.lease_time[1]))*CLOCK_SECOND/2;
} else {
s.ticks = ~0u;
}
etimer_set(&s.etimer, s.ticks);
PT_YIELD_UNTIL(&s.pt, etimer_expired(&s.etimer));
/* renewing: */
xid++;
do {
while(ev != tcpip_event) {
tcpip_poll_udp(s.conn);
PT_YIELD(&s.pt);
}
send_request();
s.ticks /= 2;
etimer_set(&s.etimer, s.ticks);
do {
PT_YIELD(&s.pt);
if(ev == tcpip_event && uip_newdata() && msg_for_me() == DHCPACK) {
parse_msg();
goto bound;
}
} while(!etimer_expired(&s.etimer));
} while(s.ticks >= CLOCK_SECOND*3);
/* rebinding: */
/* lease_expired: */
dhcpc_unconfigured(&s);
goto init;
PT_END(&s.pt);
}
/*---------------------------------------------------------------------------*/
void
dhcpc_init(const void *mac_addr, int mac_len)
{
u16_t addr[2];
s.mac_addr = mac_addr;
s.mac_len = mac_len;
s.state = STATE_INITIAL;
uip_ipaddr(addr, 255,255,255,255);
s.conn = udp_new(addr, HTONS(DHCPC_SERVER_PORT), NULL);
if(s.conn != NULL) {
udp_bind(s.conn, HTONS(DHCPC_CLIENT_PORT));
}
PT_INIT(&s.pt);
}
/*---------------------------------------------------------------------------*/
void
dhcpc_appcall(process_event_t ev, void *data)
{
if(ev == tcpip_event || ev == PROCESS_EVENT_TIMER) {
handle_dhcp(ev, data);
}
}
/*---------------------------------------------------------------------------*/
void
dhcpc_request(void)
{
u16_t ipaddr[2];
if(s.state == STATE_INITIAL) {
uip_ipaddr(ipaddr, 0,0,0,0);
uip_sethostaddr(ipaddr);
handle_dhcp(PROCESS_EVENT_NONE, NULL);
}
}
/*---------------------------------------------------------------------------*/