Contrib module by Dominik Spies: autoip.h, autoip.c, dhcp.h, dhcp.c, netif.h, netif.c, etharp.h, etharp.c, opt.h: AutoIP implementation available for IPv4, with new options LWIP_AUTOIP and LWIP_DHCP_AUTOIP_COOP if you want to cooperate with DHCP. Some tips to adapt (see TODO mark in the source code).

2026-05-25 01:27:05 +08:00 · 2007-06-09 16:57:04 +00:00
parent 792f5b3f22
commit e01f342048
10 changed files with 639 additions and 12 deletions
--- a/src/core/dhcp.c
+++ b/src/core/dhcp.c
@@ -538,6 +538,10 @@ err_t dhcp_start(struct netif *netif)
  struct dhcp *dhcp = netif->dhcp;
  err_t result = ERR_OK;

+#if LWIP_DHCP_AUTOIP_COOP
+  autoip_init();
+#endif /* LWIP_DHCP_AUTOIP_COOP */
+
  LWIP_ASSERT("netif != NULL", netif != NULL);
  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));
  netif->flags &= ~NETIF_FLAG_DHCP;
@@ -766,6 +770,13 @@ static err_t dhcp_discover(struct netif *netif)
    LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | 2, ("dhcp_discover: could not allocate DHCP request\n"));
  }
  dhcp->tries++;
+#if LWIP_DHCP_AUTOIP_COOP
+  /* that means we waited 57 seconds */
+  if(dhcp->tries >= 9 && dhcp->autoip_coop_state == DHCP_AUTOIP_COOP_STATE_OFF) {
+    dhcp->autoip_coop_state = DHCP_AUTOIP_COOP_STATE_ON;
+    autoip_start(netif);
+  }
+#endif /* LWIP_DHCP_AUTOIP_COOP */
  msecs = dhcp->tries < 4 ? (dhcp->tries + 1) * 1000 : 10 * 1000;
  dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS;
  LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_discover(): set request timeout %"U16_F" msecs\n", msecs));
--- a/src/core/ipv4/autoip.c
+++ b/src/core/ipv4/autoip.c
@@ -0,0 +1,374 @@
+/**
+ * @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>
+ */
+
+#include <stdlib.h>
+#include <string.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"
+
+#if LWIP_AUTOIP /* don't build if not configured for use in lwipopt.h */
+
+/* static functions */
+static void autoip_handle_arp_conflict(struct netif *netif);
+
+/* creates random LL IP-Address */
+static void autoip_create_rand_addr(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
+ * seed random with MAC-Address for creating pseudo-ramdom linc-local address
+ */
+void
+autoip_init(void)
+{
+  /* TODO MAC_ADDRESS macaddr; */
+  
+  LWIP_DEBUGF(AUTOIP_DEBUG | DBG_TRACE | 3, ("autoip_init()\n"));
+  
+  /* TODO Get_Current_MAC_Address(&macaddr);*/
+  /*srand(
+      (macaddr.addr[2] << 24) |
+      (macaddr.addr[3] << 16) |
+      (macaddr.addr[4] <<  8) |
+      (macaddr.addr[5] <<  0)
+     );*/
+}
+
+/**
+ * TODO: Add comment
+ */
+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 | DBG_TRACE | 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 | DBG_TRACE | DBG_STATE | 1, ("autoip_handle_arp_conflict(): we are defend, send ARP Announce\n"));
+      autoip_arp_announce(netif);
+      netif->autoip->lastconflict = DEFEND_INTERVAL * AUTOIP_FINE_TIMER_TICK_PER_SECOND;
+    }
+  } else {
+    LWIP_DEBUGF(AUTOIP_DEBUG | DBG_TRACE | DBG_STATE | 1, ("autoip_handle_arp_conflict(): we do not defend, retreating\n"));
+    /* TODO: close all TCP sessions */
+    autoip_start(netif);
+  }
+}
+
+/**
+ * TODO: Add comment
+ */
+static void
+autoip_create_rand_addr(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 = htonl((u32_t)(rand()  % (0xA9FEFEFF + 1 - 0xA9FE0100) + 0xA9FE0100));
+}
+
+/**
+ * TODO: Add comment
+ */
+static err_t
+autoip_arp_announce(struct netif *netif)
+{
+  struct eth_addr eth_addr_bc, eth_addr_zero;
+  u8_t k = netif->hwaddr_len;
+
+  while(k > 0) {
+    k--;
+    eth_addr_bc.addr[k]    = 0xFF;
+    eth_addr_zero.addr[k]  = 0x00;
+  }
+
+  return etharp_raw( netif,
+                     (struct eth_addr *)netif->hwaddr,
+                     &eth_addr_bc,
+                     (struct eth_addr *)netif->hwaddr,
+                     &netif->autoip->llipaddr,
+                     &eth_addr_zero,
+                     &netif->autoip->llipaddr,
+                     ARP_REQUEST
+                   );
+}
+
+/**
+ * TODO: Add comment
+ */
+static err_t
+autoip_bind(struct netif *netif)
+{
+  struct autoip *autoip = netif->autoip;
+  struct ip_addr sn_mask, gw_addr;
+  LWIP_DEBUGF(AUTOIP_DEBUG | DBG_TRACE | 3, ("autoip_bind(netif=%p) %c%c%"U16_F"\n", (void*)netif, netif->name[0], netif->name[1], (u16_t)netif->num));
+
+  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;
+}
+
+/**
+ * TODO: Add comment
+ */
+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 | DBG_TRACE | 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 | DBG_TRACE, ("autoip_start(): starting new AUTOIP client\n"));
+    autoip = mem_malloc(sizeof(struct autoip));
+    if(autoip == NULL) {
+      LWIP_DEBUGF(AUTOIP_DEBUG | 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 | 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(&(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 = (rand() % (PROBE_WAIT * AUTOIP_FINE_TIMER_TICK_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_FINE_TIMER_TICK_PER_SECOND;
+  }
+
+  return result;
+}
+
+/**
+ * TODO: Add comment
+ */
+err_t
+autoip_stop(struct netif *netif)
+{
+  netif->autoip->state = AUTOIP_STATE_OFF;
+  netif_set_down(netif);
+  return ERR_OK;
+}
+
+/**
+ * TODO: Add comment
+ */
+void
+autoip_fine_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 | DBG_TRACE | 3, ("autoip_fine_tmr()AutoIP-Sate: %d\n", netif->autoip->state));
+
+      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_FINE_TIMER_TICK_PER_SECOND;
+            } else {
+              etharp_request(netif, &(netif->autoip->llipaddr));
+              LWIP_DEBUGF(AUTOIP_DEBUG | DBG_TRACE | 3, ("autoip_fine_tmr() PROBING Sent Probe\n"));
+              netif->autoip->sent_num++;
+              /* calculate time to wait to next probe */
+              netif->autoip->ttw = (rand() % ((PROBE_MAX - PROBE_MIN) * AUTOIP_FINE_TIMER_TICK_PER_SECOND) ) + PROBE_MIN * AUTOIP_FINE_TIMER_TICK_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 | DBG_TRACE | 3, ("autoip_fine_tmr() ANNOUNCING Sent Announce\n"));
+              netif->autoip->sent_num++;
+              netif->autoip->ttw = ANNOUNCE_INTERVAL * AUTOIP_FINE_TIMER_TICK_PER_SECOND;
+            }
+          }
+          break;
+      }
+    }
+    /* proceed to next network interface */
+    netif = netif->next;
+  }
+}
+
+/**
+ * TODO: Add comment
+ */
+void
+autoip_arp_reply(struct netif *netif, struct etharp_hdr *hdr)
+{
+  LWIP_DEBUGF(AUTOIP_DEBUG | 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 | DBG_TRACE | 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 | DBG_TRACE | DBG_STATE | 1, ("autoip_arp_reply(): Conflicting ARP-Packet detected\n"));
+        autoip_handle_arp_conflict(netif);
+      }
+    }
+  }
+}
+
+#endif /* LWIP_AUTOIP */
--- a/src/core/netif.c
+++ b/src/core/netif.c
@@ -92,7 +92,11 @@ netif_add(struct netif *netif, struct ip_addr *ipaddr, struct ip_addr *netmask,
 #if LWIP_DHCP
  /* netif not under DHCP control by default */
  netif->dhcp = NULL;
-#endif
+#endif /* LWIP_DHCP */
+#if LWIP_AUTOIP
+  /* netif not under AutoIP control by default */
+  netif->autoip = NULL;
+#endif /* LWIP_AUTOIP */
 #if LWIP_NETIF_CALLBACK
  netif->status_callback = NULL;
 #endif /* LWIP_NETIF_CALLBACK */