--- /dev/null
+/**
+ * @file
+ * AutoIP Automatic LinkLocal IP Configuration
+ *
+ */
+
+/*
+ *
+ * Copyright (c) 2007 Dominik Spies <kontakt@dspies.de>
+ * 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.
+ *
+ * Author: Dominik Spies <kontakt@dspies.de>
+ *
+ * This is a AutoIP implementation for the lwIP TCP/IP stack. It aims to conform
+ * with RFC 3927.
+ *
+ *
+ * Please coordinate changes and requests with Dominik Spies
+ * <kontakt@dspies.de>
+ */
+
+/*******************************************************************************
+ * USAGE:
+ *
+ * define LWIP_AUTOIP 1 in your lwipopts.h
+ *
+ * If you don't use tcpip.c (so, don't call, you don't call tcpip_init):
+ * - First, call autoip_init().
+ * - call autoip_tmr() all AUTOIP_TMR_INTERVAL msces,
+ * that should be defined in autoip.h.
+ * I recommend a value of 100. The value must divide 1000 with a remainder almost 0.
+ * Possible values are 1000, 500, 333, 250, 200, 166, 142, 125, 111, 100 ....
+ *
+ * Without DHCP:
+ * - Call autoip_start() after netif_add().
+ *
+ * With DHCP:
+ * - define LWIP_DHCP_AUTOIP_COOP 1 in your lwipopts.h.
+ * - Configure your DHCP Client.
+ *
+ */
+
+#include "lwip/opt.h"
+
+#if LWIP_AUTOIP /* don't build if not configured for use in lwipopts.h */
+
+#include "lwip/mem.h"
+#include "lwip/udp.h"
+#include "lwip/ip_addr.h"
+#include "lwip/netif.h"
+#include "lwip/autoip.h"
+#include "netif/etharp.h"
+
+#include <stdlib.h>
+#include <string.h>
+
+/* Pseudo random macro based on netif informations.
+ * You could use "rand()" from the C Library if you define LWIP_AUTOIP_RAND in lwipopts.h */
+#ifndef LWIP_AUTOIP_RAND
+#define LWIP_AUTOIP_RAND(netif) ( (((u32_t)((netif->hwaddr[5]) & 0xff) << 24) | \
+ ((u32_t)((netif->hwaddr[3]) & 0xff) << 16) | \
+ ((u32_t)((netif->hwaddr[2]) & 0xff) << 8) | \
+ ((u32_t)((netif->hwaddr[4]) & 0xff))) + \
+ (netif->autoip?netif->autoip->tried_llipaddr:0))
+#endif /* LWIP_AUTOIP_RAND */
+
+/* static functions */
+static void autoip_handle_arp_conflict(struct netif *netif);
+
+/* creates random LL IP-Address for a network interface */
+static void autoip_create_rand_addr(struct netif *netif, struct ip_addr *RandomIPAddr);
+
+/* sends an ARP announce */
+static err_t autoip_arp_announce(struct netif *netif);
+
+/* configure interface for use with current LL IP-Address */
+static err_t autoip_bind(struct netif *netif);
+
+/**
+ * Initialize this module
+ */
+void
+autoip_init(void)
+{
+ LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | 3, ("autoip_init()\n"));
+}
+
+/**
+ * Handle a IP address conflict after an ARP conflict detection
+ */
+static void
+autoip_handle_arp_conflict(struct netif *netif)
+{
+ /* Somehow detect if we are defending or retreating */
+ unsigned char defend = 1; /* tbd */
+
+ if(defend) {
+ if(netif->autoip->lastconflict > 0) {
+ /* retreat, there was a conflicting ARP in the last
+ * DEFEND_INTERVAL seconds
+ */
+ LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE | 1,
+ ("autoip_handle_arp_conflict(): we are defending, but in DEFEND_INTERVAL, retreating\n"));
+
+ /* TODO: close all TCP sessions */
+ autoip_start(netif);
+ } else {
+ LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE | 1,
+ ("autoip_handle_arp_conflict(): we are defend, send ARP Announce\n"));
+ autoip_arp_announce(netif);
+ netif->autoip->lastconflict = DEFEND_INTERVAL * AUTOIP_TICKS_PER_SECOND;
+ }
+ } else {
+ LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE | 1,
+ ("autoip_handle_arp_conflict(): we do not defend, retreating\n"));
+ /* TODO: close all TCP sessions */
+ autoip_start(netif);
+ }
+}
+
+/**
+ * Create an IP-Address out of range 169.254.1.0 to 169.254.254.255
+ *
+ * @param netif network interface on which create the IP-Address
+ * @param RandomIPAddr ip address to initialize
+ */
+static void
+autoip_create_rand_addr(struct netif *netif, struct ip_addr *RandomIPAddr)
+{
+ /* Here we create an IP-Address out of range 169.254.1.0 to 169.254.254.255
+ * compliant to RFC 3927 Section 2.1
+ * We have 254 * 256 possibilities
+ */
+
+ RandomIPAddr->addr = (0xA9FE0100 + ((u32_t)(((u8_t)(netif->hwaddr[4])) |
+ ((u32_t)((u8_t)(netif->hwaddr[5]))) << 8)) + netif->autoip->tried_llipaddr);
+
+ if (RandomIPAddr->addr>0xA9FEFEFF) {
+ RandomIPAddr->addr = (0xA9FE0100 + (RandomIPAddr->addr-0xA9FEFEFF));
+ }
+ if (RandomIPAddr->addr<0xA9FE0100) {
+ RandomIPAddr->addr = (0xA9FEFEFF - (0xA9FE0100-RandomIPAddr->addr));
+ }
+ RandomIPAddr->addr = htonl(RandomIPAddr->addr);
+
+ LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE | 1,
+ ("autoip_create_rand_addr(): tried_llipaddr=%"U16_F", 0x%08"X32_F"\n",
+ (u16_t)(netif->autoip->tried_llipaddr), (u32_t)(RandomIPAddr->addr)));
+}
+
+/**
+ * Sends an ARP announce from a network interface
+ *
+ * @param netif network interface used to send the announce
+ */
+static err_t
+autoip_arp_announce(struct netif *netif)
+{
+ return etharp_raw(netif, (struct eth_addr *)netif->hwaddr, ðbroadcast,
+ (struct eth_addr *)netif->hwaddr, &netif->autoip->llipaddr, ðzero,
+ &netif->autoip->llipaddr, ARP_REQUEST);
+}
+
+/**
+ * Configure interface for use with current LL IP-Address
+ *
+ * @param netif network interface to configure with current LL IP-Address
+ */
+static err_t
+autoip_bind(struct netif *netif)
+{
+ struct autoip *autoip = netif->autoip;
+ struct ip_addr sn_mask, gw_addr;
+
+ LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | 3,
+ ("autoip_bind(netif=%p) %c%c%"U16_F" 0x%08"X32_F"\n",
+ (void*)netif, netif->name[0], netif->name[1], (u16_t)netif->num, autoip->llipaddr.addr));
+
+ IP4_ADDR(&sn_mask, 255, 255, 0, 0);
+ IP4_ADDR(&gw_addr, 0, 0, 0, 0);
+
+ netif_set_ipaddr(netif, &autoip->llipaddr);
+ netif_set_netmask(netif, &sn_mask);
+ netif_set_gw(netif, &gw_addr);
+
+ /* bring the interface up */
+ netif_set_up(netif);
+
+ return ERR_OK;
+}
+
+/**
+ * Start AutoIP client
+ *
+ * @param netif network interface on which start the AutoIP client
+ */
+err_t
+autoip_start(struct netif *netif)
+{
+ struct autoip *autoip = netif->autoip;
+ err_t result = ERR_OK;
+
+ if(netif_is_up(netif)) {
+ netif_set_down(netif);
+ }
+
+ /* Set IP-Address, Netmask and Gateway to 0 to make sure that
+ * ARP Packets are formed correctly
+ */
+ netif->ip_addr.addr = 0;
+ netif->netmask.addr = 0;
+ netif->gw.addr = 0;
+
+ LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
+ ("autoip_start(netif=%p) %c%c%"U16_F"\n", (void*)netif, netif->name[0],
+ netif->name[1], (u16_t)netif->num));
+ if(autoip == NULL) {
+ /* no AutoIP client attached yet? */
+ LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE,
+ ("autoip_start(): starting new AUTOIP client\n"));
+ autoip = mem_malloc(sizeof(struct autoip));
+ if(autoip == NULL) {
+ LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE,
+ ("autoip_start(): could not allocate autoip\n"));
+ return ERR_MEM;
+ }
+ memset( autoip, 0, sizeof(struct autoip));
+ /* store this AutoIP client in the netif */
+ netif->autoip = autoip;
+ LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE, ("autoip_start(): allocated autoip"));
+ } else {
+ autoip->state = AUTOIP_STATE_OFF;
+ autoip->ttw = 0;
+ autoip->sent_num = 0;
+ memset(&autoip->llipaddr, 0, sizeof(struct ip_addr));
+ autoip->lastconflict = 0;
+ }
+
+ autoip_create_rand_addr(netif, &(autoip->llipaddr));
+ autoip->tried_llipaddr++;
+ autoip->state = AUTOIP_STATE_PROBING;
+ autoip->sent_num = 0;
+
+ /* time to wait to first probe, this is randomly
+ * choosen out of 0 to PROBE_WAIT seconds.
+ * compliant to RFC 3927 Section 2.2.1
+ */
+ autoip->ttw = (u16_t)(LWIP_AUTOIP_RAND(netif) % (PROBE_WAIT * AUTOIP_TICKS_PER_SECOND));
+
+ /*
+ * if we tried more then MAX_CONFLICTS we must limit our rate for
+ * accquiring and probing address
+ * compliant to RFC 3927 Section 2.2.1
+ */
+
+ if(autoip->tried_llipaddr > MAX_CONFLICTS) {
+ autoip->ttw = RATE_LIMIT_INTERVAL * AUTOIP_TICKS_PER_SECOND;
+ }
+
+ return result;
+}
+
+/**
+ * Stop AutoIP client
+ *
+ * @param netif network interface on which stop the AutoIP client
+ */
+err_t
+autoip_stop(struct netif *netif)
+{
+ netif->autoip->state = AUTOIP_STATE_OFF;
+ netif_set_down(netif);
+ return ERR_OK;
+}
+
+/**
+ * Has to be called in loop every AUTOIP_TMR_INTERVAL milliseconds
+ */
+void
+autoip_tmr()
+{
+ struct netif *netif = netif_list;
+ /* loop through netif's */
+ while (netif != NULL) {
+ /* only act on AutoIP configured interfaces */
+ if (netif->autoip != NULL) {
+ if(netif->autoip->lastconflict > 0) {
+ netif->autoip->lastconflict--;
+ }
+
+ LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE,
+ ("autoip_tmr() AutoIP-State: %"U16_F", ttw=%"U16_F"\n",
+ (u16_t)(netif->autoip->state), netif->autoip->ttw));
+
+ switch(netif->autoip->state) {
+ case AUTOIP_STATE_PROBING:
+ if(netif->autoip->ttw > 0) {
+ netif->autoip->ttw--;
+ } else {
+ if(netif->autoip->sent_num == PROBE_NUM) {
+ netif->autoip->state = AUTOIP_STATE_ANNOUNCING;
+ netif->autoip->sent_num = 0;
+ netif->autoip->ttw = ANNOUNCE_WAIT * AUTOIP_TICKS_PER_SECOND;
+ } else {
+ etharp_request(netif, &(netif->autoip->llipaddr));
+ LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | 3,
+ ("autoip_tmr() PROBING Sent Probe\n"));
+ netif->autoip->sent_num++;
+ /* calculate time to wait to next probe */
+ netif->autoip->ttw = (u16_t)((LWIP_AUTOIP_RAND(netif) %
+ ((PROBE_MAX - PROBE_MIN) * AUTOIP_TICKS_PER_SECOND) ) +
+ PROBE_MIN * AUTOIP_TICKS_PER_SECOND);
+ }
+ }
+ break;
+
+ case AUTOIP_STATE_ANNOUNCING:
+ if(netif->autoip->ttw > 0) {
+ netif->autoip->ttw--;
+ } else {
+ if(netif->autoip->sent_num == 0) {
+ /* We are here the first time, so we waited ANNOUNCE_WAIT seconds
+ * Now we can bind to an IP address and use it
+ */
+ autoip_bind(netif);
+ }
+
+ if(netif->autoip->sent_num == ANNOUNCE_NUM) {
+ netif->autoip->state = AUTOIP_STATE_BOUND;
+ netif->autoip->sent_num = 0;
+ netif->autoip->ttw = 0;
+ } else {
+ autoip_arp_announce(netif);
+ LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | 3,
+ ("autoip_tmr() ANNOUNCING Sent Announce\n"));
+ netif->autoip->sent_num++;
+ netif->autoip->ttw = ANNOUNCE_INTERVAL * AUTOIP_TICKS_PER_SECOND;
+ }
+ }
+ break;
+ }
+ }
+ /* proceed to next network interface */
+ netif = netif->next;
+ }
+}
+
+/**
+ * Handles every incoming ARP Packet, called by etharp_arp_input.
+ *
+ * @param netif network interface to use for autoip processing
+ * @param hdr Incoming ARP packet
+ */
+void
+autoip_arp_reply(struct netif *netif, struct etharp_hdr *hdr)
+{
+ LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | 3, ("autoip_arp_reply()\n"));
+ if ((netif->autoip != NULL) && (netif->autoip->state != AUTOIP_STATE_OFF)) {
+ /* when ip.src == llipaddr && hw.src != netif->hwaddr
+ *
+ * when probing ip.dst == llipaddr && hw.src != netif->hwaddr
+ * we have a conflict and must solve it
+ */
+ struct ip_addr sipaddr, dipaddr;
+ struct eth_addr netifaddr;
+ netifaddr.addr[0] = netif->hwaddr[0];
+ netifaddr.addr[1] = netif->hwaddr[1];
+ netifaddr.addr[2] = netif->hwaddr[2];
+ netifaddr.addr[3] = netif->hwaddr[3];
+ netifaddr.addr[4] = netif->hwaddr[4];
+ netifaddr.addr[5] = netif->hwaddr[5];
+
+ /* Copy struct ip_addr2 to aligned ip_addr, to support compilers without
+ * structure packing (not using structure copy which breaks strict-aliasing rules).
+ */
+ MEMCPY(&sipaddr, &hdr->sipaddr, sizeof(sipaddr));
+ MEMCPY(&dipaddr, &hdr->dipaddr, sizeof(dipaddr));
+
+ if ((netif->autoip->state == AUTOIP_STATE_PROBING) ||
+ ((netif->autoip->state == AUTOIP_STATE_ANNOUNCING) &&
+ (netif->autoip->sent_num == 0))) {
+ /* RFC 3927 Section 2.2.1:
+ * from beginning to after ANNOUNCE_WAIT
+ * seconds we have a conflict if
+ * ip.src == llipaddr OR
+ * ip.dst == llipaddr && hw.src != own hwaddr
+ */
+ if ((ip_addr_cmp(&sipaddr, &netif->autoip->llipaddr)) ||
+ (ip_addr_cmp(&dipaddr, &netif->autoip->llipaddr) &&
+ !eth_addr_cmp(&netifaddr, &hdr->shwaddr))) {
+ LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE | 1,
+ ("autoip_arp_reply(): Probe Conflict detected\n"));
+ autoip_start(netif);
+ }
+ } else {
+ /* RFC 3927 Section 2.5:
+ * in any state we have a conflict if
+ * ip.src == llipaddr && hw.src != own hwaddr
+ */
+ if (ip_addr_cmp(&sipaddr, &netif->autoip->llipaddr) &&
+ !eth_addr_cmp(&netifaddr, &hdr->shwaddr)) {
+ LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE | 1,
+ ("autoip_arp_reply(): Conflicting ARP-Packet detected\n"));
+ autoip_handle_arp_conflict(netif);
+ }
+ }
+ }
+}
+
+#endif /* LWIP_AUTOIP */
