net_S3c44b0.rar_arm_cs8900a

/** * @file * * Dynamic Host Configuration Protocol client */ /* * * Copyright (c) 2001-2004 Leon Woestenberg <leon.woestenberg@gmx.net> * Copyright (c) 2001-2004 Axon Digital Design B.V., The Netherlands. * 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. The name of the author may not be used to endorse or promote products * derived from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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 a contribution to the lwIP TCP/IP stack. * The Swedish Institute of Computer Science and Adam Dunkels * are specifically granted permission to redistribute this * source code. * * Author: Leon Woestenberg <leon.woestenberg@gmx.net> * * This is a DHCP client for the lwIP TCP/IP stack. It aims to conform * with RFC 2131 and RFC 2132. * * TODO: * - Proper parsing of DHCP messages exploiting file/sname field overloading. * - Add JavaDoc style documentation (API, internals). * - Support for interfaces other than Ethernet (SLIP, PPP, ...) * * Please coordinate changes and requests with Leon Woestenberg * <leon.woestenberg@gmx.net> * * Integration with your code: * * In lwip/dhcp.h * #define DHCP_COARSE_TIMER_SECS (recommended 60 which is a minute) * #define DHCP_FINE_TIMER_MSECS (recommended 500 which equals TCP coarse timer) * * Then have your application call dhcp_coarse_tmr() and * dhcp_fine_tmr() on the defined intervals. * * dhcp_start(struct netif *netif); * starts a DHCP client instance which configures the interface by * obtaining an IP address lease and maintaining it. * * Use dhcp_release(netif) to end the lease and use dhcp_stop(netif) * to remove the DHCP client. * */ #include "lwip/stats.h" #include "lwip/mem.h" #include "lwip/udp.h" #include "lwip/ip_addr.h" #include "lwip/netif.h" #include "lwip/inet.h" #include "netif/etharp.h" #include "lwip/sys.h" #include "lwip/opt.h" #include "lwip/dhcp.h" #if LWIP_DHCP /* don't build if not configured for use in lwipopt.h */ /** global transaction identifier, must be * unique for each DHCP request. */ static u32_t xid = 0xABCD0000; /** DHCP client state machine functions */ static void dhcp_handle_ack(struct netif *netif); static void dhcp_handle_nak(struct netif *netif); static void dhcp_handle_offer(struct netif *netif); static err_t dhcp_discover(struct netif *netif); static err_t dhcp_select(struct netif *netif); static void dhcp_check(struct netif *netif); static void dhcp_bind(struct netif *netif); static err_t dhcp_decline(struct netif *netif); static err_t dhcp_rebind(struct netif *netif); static err_t dhcp_release(struct netif *netif); static void dhcp_set_state(struct dhcp *dhcp, unsigned char new_state); /** receive, unfold, parse and free incoming messages */ static void dhcp_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, struct ip_addr *addr, u16_t port); static err_t dhcp_unfold_reply(struct dhcp *dhcp); static u8_t *dhcp_get_option_ptr(struct dhcp *dhcp, u8_t option_type); static u8_t dhcp_get_option_byte(u8_t *ptr); static u16_t dhcp_get_option_short(u8_t *ptr); static u32_t dhcp_get_option_long(u8_t *ptr); static void dhcp_free_reply(struct dhcp *dhcp); /** set the DHCP timers */ static void dhcp_timeout(struct netif *netif); static void dhcp_t1_timeout(struct netif *netif); static void dhcp_t2_timeout(struct netif *netif); /** build outgoing messages */ /** create a DHCP request, fill in common headers */ static err_t dhcp_create_request(struct netif *netif); /** free a DHCP request */ static void dhcp_delete_request(struct netif *netif); /** add a DHCP option (type, then length in bytes) */ static void dhcp_option(struct dhcp *dhcp, u8_t option_type, u8_t option_len); /** add option values */ static void dhcp_option_byte(struct dhcp *dhcp, u8_t value); static void dhcp_option_short(struct dhcp *dhcp, u16_t value); static void dhcp_option_long(struct dhcp *dhcp, u32_t value); /** always add the DHCP options trailer to end and pad */ static void dhcp_option_trailer(struct dhcp *dhcp); /** * Back-off the DHCP client (because of a received NAK response). * * Back-off the DHCP client because of a received NAK. Receiving a * NAK means the client asked for something non-sensible, for * example when it tries to renew a lease obtained on another network. * * We back-off and will end up restarting a fresh DHCP negotiation later. * * @param state pointer to DHCP state structure */ static void dhcp_handle_nak(struct netif *netif) { struct dhcp *dhcp = netif->dhcp; u16_t msecs = 10 * 1000; LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | 3, ("dhcp_handle_nak(netif=%p) %c%c%u\n", netif, netif->name[0], netif->name[1], (unsigned int)netif->num)); dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS; LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | DBG_STATE, ("dhcp_handle_nak(): set request timeout %u msecs\n", msecs)); dhcp_set_state(dhcp, DHCP_BACKING_OFF); } /** * Checks if the offered IP address is already in use. * * It does so by sending an ARP request for the offered address and * entering CHECKING state. If no ARP reply is received within a small * interval, the address is assumed to be free for use by us. */ static void dhcp_check(struct netif *netif) { struct dhcp *dhcp = netif->dhcp; err_t result; u16_t msecs; LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | 3, ("dhcp_check(netif=%p) %c%c\n", (void *)netif, (unsigned int)netif->name[0], (unsigned int)netif->name[1])); /* create an ARP query for the offered IP address, expecting that no host responds, as the IP address should not be in use. */ result = etharp_query(netif, &dhcp->offered_ip_addr, NULL); if (result != ERR_OK) { LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | 2, ("dhcp_check: could not perform ARP query\n")); } dhcp->tries++; msecs = 500; dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS; LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | DBG_STATE, ("dhcp_check(): set request timeout %u msecs\n", msecs)); dhcp_set_state(dhcp, DHCP_CHECKING); } /** * Remember the configuration offered by a DHCP server. * * @param state pointer to DHCP state structure */ static void dhcp_handle_offer(struct netif *netif) { struct dhcp *dhcp = netif->dhcp; /* obtain the server address */ u8_t *option_ptr = dhcp_get_option_ptr(dhcp, DHCP_OPTION_SERVER_ID); LWIP_DEBUGF(DHCP_DEBUG | DBG_TRACE | 3, ("dhcp_handle_offer(netif=%p) %c%c%u\n", netif, netif->name[0], netif->name[1], netif->num)); if (option_ptr != NULL) { dhcp->server_ip_addr.addr = htonl(dhcp_get_option_long(&option_ptr[2])); LWIP_DEBUGF(DHCP_DEBUG | DBG_STATE, ("dhcp_handle_offer(): server 0x%08lx\n", dhcp->server_ip_addr.addr)); /* remember offered address */ ip_addr_set(&dhcp->offered_ip_addr,