1 | /**
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2 | * @file
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3 | * AutoIP Automatic LinkLocal IP Configuration
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4 | *
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5 | */
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6 |
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7 | /*
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8 | *
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9 | * Copyright (c) 2007 Dominik Spies <kontakt@dspies.de>
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10 | * All rights reserved.
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11 | *
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12 | * Redistribution and use in source and binary forms, with or without modification,
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13 | * are permitted provided that the following conditions are met:
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14 | *
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15 | * 1. Redistributions of source code must retain the above copyright notice,
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16 | * this list of conditions and the following disclaimer.
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17 | * 2. Redistributions in binary form must reproduce the above copyright notice,
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18 | * this list of conditions and the following disclaimer in the documentation
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19 | * and/or other materials provided with the distribution.
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20 | * 3. The name of the author may not be used to endorse or promote products
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21 | * derived from this software without specific prior written permission.
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22 | *
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23 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
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24 | * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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25 | * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
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26 | * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
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27 | * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
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28 | * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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29 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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30 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
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31 | * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
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32 | * OF SUCH DAMAGE.
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33 | *
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34 | * Author: Dominik Spies <kontakt@dspies.de>
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35 | *
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36 | * This is a AutoIP implementation for the lwIP TCP/IP stack. It aims to conform
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37 | * with RFC 3927.
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38 | *
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39 | *
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40 | * Please coordinate changes and requests with Dominik Spies
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41 | * <kontakt@dspies.de>
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42 | */
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43 |
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44 | /*******************************************************************************
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45 | * USAGE:
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46 | *
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47 | * define LWIP_AUTOIP 1 in your lwipopts.h
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48 | *
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49 | * If you don't use tcpip.c (so, don't call, you don't call tcpip_init):
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50 | * - First, call autoip_init().
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51 | * - call autoip_tmr() all AUTOIP_TMR_INTERVAL msces,
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52 | * that should be defined in autoip.h.
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53 | * I recommend a value of 100. The value must divide 1000 with a remainder almost 0.
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54 | * Possible values are 1000, 500, 333, 250, 200, 166, 142, 125, 111, 100 ....
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55 | *
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56 | * Without DHCP:
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57 | * - Call autoip_start() after netif_add().
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58 | *
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59 | * With DHCP:
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60 | * - define LWIP_DHCP_AUTOIP_COOP 1 in your lwipopts.h.
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61 | * - Configure your DHCP Client.
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62 | *
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63 | */
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64 |
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65 | #include "lwip/opt.h"
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66 |
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67 | #if LWIP_AUTOIP /* don't build if not configured for use in lwipopts.h */
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68 |
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69 | #include "lwip/mem.h"
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70 | #include "lwip/udp.h"
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71 | #include "lwip/ip_addr.h"
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72 | #include "lwip/netif.h"
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73 | #include "lwip/autoip.h"
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74 | #include "netif/etharp.h"
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75 |
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76 | #include <stdlib.h>
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77 | #include <string.h>
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78 |
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79 | /* 169.254.0.0 */
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80 | #define AUTOIP_NET 0xA9FE0000
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81 | /* 169.254.1.0 */
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82 | #define AUTOIP_RANGE_START (AUTOIP_NET | 0x0100)
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83 | /* 169.254.254.255 */
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84 | #define AUTOIP_RANGE_END (AUTOIP_NET | 0xFEFF)
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85 |
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86 |
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87 | /** Pseudo random macro based on netif informations.
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88 | * You could use "rand()" from the C Library if you define LWIP_AUTOIP_RAND in lwipopts.h */
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89 | #ifndef LWIP_AUTOIP_RAND
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90 | #define LWIP_AUTOIP_RAND(netif) ( (((u32_t)((netif->hwaddr[5]) & 0xff) << 24) | \
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91 | ((u32_t)((netif->hwaddr[3]) & 0xff) << 16) | \
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92 | ((u32_t)((netif->hwaddr[2]) & 0xff) << 8) | \
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93 | ((u32_t)((netif->hwaddr[4]) & 0xff))) + \
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94 | (netif->autoip?netif->autoip->tried_llipaddr:0))
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95 | #endif /* LWIP_AUTOIP_RAND */
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96 |
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97 | /**
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98 | * Macro that generates the initial IP address to be tried by AUTOIP.
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99 | * If you want to override this, define it to something else in lwipopts.h.
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100 | */
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101 | #ifndef LWIP_AUTOIP_CREATE_SEED_ADDR
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102 | #define LWIP_AUTOIP_CREATE_SEED_ADDR(netif) \
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103 | htonl(AUTOIP_RANGE_START + ((u32_t)(((u8_t)(netif->hwaddr[4])) | \
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104 | ((u32_t)((u8_t)(netif->hwaddr[5]))) << 8)))
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105 | #endif /* LWIP_AUTOIP_CREATE_SEED_ADDR */
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106 |
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107 | /* static functions */
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108 | static void autoip_handle_arp_conflict(struct netif *netif);
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109 |
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110 | /* creates a pseudo random LL IP-Address for a network interface */
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111 | static void autoip_create_addr(struct netif *netif, ip_addr_t *ipaddr);
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112 |
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113 | /* sends an ARP probe */
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114 | static err_t autoip_arp_probe(struct netif *netif);
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115 |
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116 | /* sends an ARP announce */
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117 | static err_t autoip_arp_announce(struct netif *netif);
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118 |
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119 | /* configure interface for use with current LL IP-Address */
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120 | static err_t autoip_bind(struct netif *netif);
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121 |
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122 | /* start sending probes for llipaddr */
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123 | static void autoip_start_probing(struct netif *netif);
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124 |
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125 |
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126 | /** Set a statically allocated struct autoip to work with.
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127 | * Using this prevents autoip_start to allocate it using mem_malloc.
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128 | *
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129 | * @param netif the netif for which to set the struct autoip
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130 | * @param dhcp (uninitialised) dhcp struct allocated by the application
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131 | */
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132 | void
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133 | autoip_set_struct(struct netif *netif, struct autoip *autoip)
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134 | {
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135 | LWIP_ASSERT("netif != NULL", netif != NULL);
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136 | LWIP_ASSERT("autoip != NULL", autoip != NULL);
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137 | LWIP_ASSERT("netif already has a struct autoip set", netif->autoip == NULL);
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138 |
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139 | /* clear data structure */
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140 | memset(autoip, 0, sizeof(struct autoip));
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141 | /* autoip->state = AUTOIP_STATE_OFF; */
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142 | netif->autoip = autoip;
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143 | }
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144 |
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145 | /** Restart AutoIP client and check the next address (conflict detected)
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146 | *
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147 | * @param netif The netif under AutoIP control
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148 | */
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149 | static void
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150 | autoip_restart(struct netif *netif)
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151 | {
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152 | netif->autoip->tried_llipaddr++;
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153 | autoip_start(netif);
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154 | }
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155 |
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156 | /**
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157 | * Handle a IP address conflict after an ARP conflict detection
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158 | */
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159 | static void
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160 | autoip_handle_arp_conflict(struct netif *netif)
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161 | {
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162 | /* Somehow detect if we are defending or retreating */
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163 | unsigned char defend = 1; /* tbd */
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164 |
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165 | if (defend) {
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166 | if (netif->autoip->lastconflict > 0) {
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167 | /* retreat, there was a conflicting ARP in the last
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168 | * DEFEND_INTERVAL seconds
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169 | */
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170 | LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
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171 | ("autoip_handle_arp_conflict(): we are defending, but in DEFEND_INTERVAL, retreating\n"));
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172 |
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173 | /* TODO: close all TCP sessions */
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174 | autoip_restart(netif);
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175 | } else {
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176 | LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
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177 | ("autoip_handle_arp_conflict(): we are defend, send ARP Announce\n"));
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178 | autoip_arp_announce(netif);
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179 | netif->autoip->lastconflict = DEFEND_INTERVAL * AUTOIP_TICKS_PER_SECOND;
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180 | }
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181 | } else {
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182 | LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
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183 | ("autoip_handle_arp_conflict(): we do not defend, retreating\n"));
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184 | /* TODO: close all TCP sessions */
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185 | autoip_restart(netif);
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186 | }
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187 | }
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188 |
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189 | /**
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190 | * Create an IP-Address out of range 169.254.1.0 to 169.254.254.255
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191 | *
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192 | * @param netif network interface on which create the IP-Address
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193 | * @param ipaddr ip address to initialize
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194 | */
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195 | static void
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196 | autoip_create_addr(struct netif *netif, ip_addr_t *ipaddr)
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197 | {
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198 | /* Here we create an IP-Address out of range 169.254.1.0 to 169.254.254.255
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199 | * compliant to RFC 3927 Section 2.1
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200 | * We have 254 * 256 possibilities */
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201 |
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202 | u32_t addr = ntohl(LWIP_AUTOIP_CREATE_SEED_ADDR(netif));
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203 | addr += netif->autoip->tried_llipaddr;
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204 | addr = AUTOIP_NET | (addr & 0xffff);
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205 | /* Now, 169.254.0.0 <= addr <= 169.254.255.255 */
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206 |
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207 | if (addr < AUTOIP_RANGE_START) {
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208 | addr += AUTOIP_RANGE_END - AUTOIP_RANGE_START + 1;
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209 | }
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210 | if (addr > AUTOIP_RANGE_END) {
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211 | addr -= AUTOIP_RANGE_END - AUTOIP_RANGE_START + 1;
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212 | }
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213 | LWIP_ASSERT("AUTOIP address not in range", (addr >= AUTOIP_RANGE_START) &&
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214 | (addr <= AUTOIP_RANGE_END));
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215 | ip4_addr_set_u32(ipaddr, htonl(addr));
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216 |
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217 | LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
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218 | ("autoip_create_addr(): tried_llipaddr=%"U16_F", %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
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219 | (u16_t)(netif->autoip->tried_llipaddr), ip4_addr1_16(ipaddr), ip4_addr2_16(ipaddr),
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220 | ip4_addr3_16(ipaddr), ip4_addr4_16(ipaddr)));
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221 | }
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222 |
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223 | /**
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224 | * Sends an ARP probe from a network interface
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225 | *
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226 | * @param netif network interface used to send the probe
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227 | */
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228 | static err_t
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229 | autoip_arp_probe(struct netif *netif)
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230 | {
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231 | return etharp_raw(netif, (struct eth_addr *)netif->hwaddr, ðbroadcast,
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232 | (struct eth_addr *)netif->hwaddr, IP_ADDR_ANY, ðzero,
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233 | &netif->autoip->llipaddr, ARP_REQUEST);
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234 | }
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235 |
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236 | /**
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237 | * Sends an ARP announce from a network interface
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238 | *
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239 | * @param netif network interface used to send the announce
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240 | */
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241 | static err_t
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242 | autoip_arp_announce(struct netif *netif)
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243 | {
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244 | return etharp_raw(netif, (struct eth_addr *)netif->hwaddr, ðbroadcast,
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245 | (struct eth_addr *)netif->hwaddr, &netif->autoip->llipaddr, ðzero,
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246 | &netif->autoip->llipaddr, ARP_REQUEST);
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247 | }
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248 |
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249 | /**
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250 | * Configure interface for use with current LL IP-Address
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251 | *
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252 | * @param netif network interface to configure with current LL IP-Address
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253 | */
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254 | static err_t
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255 | autoip_bind(struct netif *netif)
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256 | {
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257 | struct autoip *autoip = netif->autoip;
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258 | ip_addr_t sn_mask, gw_addr;
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259 |
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260 | LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE,
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261 | ("autoip_bind(netif=%p) %c%c%"U16_F" %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
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262 | (void*)netif, netif->name[0], netif->name[1], (u16_t)netif->num,
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263 | ip4_addr1_16(&autoip->llipaddr), ip4_addr2_16(&autoip->llipaddr),
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264 | ip4_addr3_16(&autoip->llipaddr), ip4_addr4_16(&autoip->llipaddr)));
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265 |
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266 | IP4_ADDR(&sn_mask, 255, 255, 0, 0);
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267 | IP4_ADDR(&gw_addr, 0, 0, 0, 0);
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268 |
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269 | netif_set_ipaddr(netif, &autoip->llipaddr);
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270 | netif_set_netmask(netif, &sn_mask);
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271 | netif_set_gw(netif, &gw_addr);
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272 |
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273 | /* bring the interface up */
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274 | netif_set_up(netif);
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275 |
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276 | return ERR_OK;
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277 | }
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278 |
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279 | /**
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280 | * Start AutoIP client
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281 | *
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282 | * @param netif network interface on which start the AutoIP client
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283 | */
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284 | err_t
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285 | autoip_start(struct netif *netif)
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286 | {
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287 | struct autoip *autoip = netif->autoip;
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288 | err_t result = ERR_OK;
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289 |
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290 | if (netif_is_up(netif)) {
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291 | netif_set_down(netif);
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292 | }
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293 |
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294 | /* Set IP-Address, Netmask and Gateway to 0 to make sure that
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295 | * ARP Packets are formed correctly
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296 | */
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297 | ip_addr_set_zero(&netif->ip_addr);
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298 | ip_addr_set_zero(&netif->netmask);
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299 | ip_addr_set_zero(&netif->gw);
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300 |
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301 | LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
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302 | ("autoip_start(netif=%p) %c%c%"U16_F"\n", (void*)netif, netif->name[0],
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303 | netif->name[1], (u16_t)netif->num));
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304 | if (autoip == NULL) {
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305 | /* no AutoIP client attached yet? */
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306 | LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE,
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307 | ("autoip_start(): starting new AUTOIP client\n"));
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308 | autoip = (struct autoip *)mem_malloc(sizeof(struct autoip));
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309 | if (autoip == NULL) {
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310 | LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE,
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311 | ("autoip_start(): could not allocate autoip\n"));
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312 | return ERR_MEM;
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313 | }
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314 | memset(autoip, 0, sizeof(struct autoip));
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315 | /* store this AutoIP client in the netif */
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316 | netif->autoip = autoip;
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317 | LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE, ("autoip_start(): allocated autoip"));
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318 | } else {
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319 | autoip->state = AUTOIP_STATE_OFF;
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320 | autoip->ttw = 0;
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321 | autoip->sent_num = 0;
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322 | ip_addr_set_zero(&autoip->llipaddr);
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323 | autoip->lastconflict = 0;
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324 | }
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325 |
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326 | autoip_create_addr(netif, &(autoip->llipaddr));
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327 | autoip_start_probing(netif);
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328 |
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329 | return result;
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330 | }
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331 |
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332 | static void
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333 | autoip_start_probing(struct netif *netif)
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334 | {
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335 | struct autoip *autoip = netif->autoip;
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336 |
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337 | autoip->state = AUTOIP_STATE_PROBING;
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338 | autoip->sent_num = 0;
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339 | LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
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340 | ("autoip_start_probing(): changing state to PROBING: %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
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341 | ip4_addr1_16(&netif->autoip->llipaddr), ip4_addr2_16(&netif->autoip->llipaddr),
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342 | ip4_addr3_16(&netif->autoip->llipaddr), ip4_addr4_16(&netif->autoip->llipaddr)));
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343 |
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344 | /* time to wait to first probe, this is randomly
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345 | * choosen out of 0 to PROBE_WAIT seconds.
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346 | * compliant to RFC 3927 Section 2.2.1
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347 | */
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348 | autoip->ttw = (u16_t)(LWIP_AUTOIP_RAND(netif) % (PROBE_WAIT * AUTOIP_TICKS_PER_SECOND));
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349 |
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350 | /*
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351 | * if we tried more then MAX_CONFLICTS we must limit our rate for
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352 | * accquiring and probing address
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353 | * compliant to RFC 3927 Section 2.2.1
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354 | */
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355 | if (autoip->tried_llipaddr > MAX_CONFLICTS) {
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356 | autoip->ttw = RATE_LIMIT_INTERVAL * AUTOIP_TICKS_PER_SECOND;
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357 | }
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358 | }
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359 |
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360 | /**
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361 | * Handle a possible change in the network configuration.
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362 | *
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363 | * If there is an AutoIP address configured, take the interface down
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364 | * and begin probing with the same address.
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365 | */
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366 | void
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367 | autoip_network_changed(struct netif *netif)
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368 | {
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369 | if (netif->autoip && netif->autoip->state != AUTOIP_STATE_OFF) {
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370 | netif_set_down(netif);
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371 | autoip_start_probing(netif);
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372 | }
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373 | }
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374 |
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375 | /**
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376 | * Stop AutoIP client
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377 | *
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378 | * @param netif network interface on which stop the AutoIP client
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379 | */
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380 | err_t
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381 | autoip_stop(struct netif *netif)
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382 | {
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383 | netif->autoip->state = AUTOIP_STATE_OFF;
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384 | netif_set_down(netif);
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385 | return ERR_OK;
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386 | }
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387 |
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388 | /**
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389 | * Has to be called in loop every AUTOIP_TMR_INTERVAL milliseconds
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390 | */
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391 | void
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392 | autoip_tmr()
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393 | {
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394 | struct netif *netif = netif_list;
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395 | /* loop through netif's */
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396 | while (netif != NULL) {
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397 | /* only act on AutoIP configured interfaces */
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398 | if (netif->autoip != NULL) {
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399 | if (netif->autoip->lastconflict > 0) {
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400 | netif->autoip->lastconflict--;
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401 | }
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402 |
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403 | LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE,
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404 | ("autoip_tmr() AutoIP-State: %"U16_F", ttw=%"U16_F"\n",
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405 | (u16_t)(netif->autoip->state), netif->autoip->ttw));
|
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406 |
|
---|
407 | switch(netif->autoip->state) {
|
---|
408 | case AUTOIP_STATE_PROBING:
|
---|
409 | if (netif->autoip->ttw > 0) {
|
---|
410 | netif->autoip->ttw--;
|
---|
411 | } else {
|
---|
412 | if (netif->autoip->sent_num >= PROBE_NUM) {
|
---|
413 | netif->autoip->state = AUTOIP_STATE_ANNOUNCING;
|
---|
414 | netif->autoip->sent_num = 0;
|
---|
415 | netif->autoip->ttw = ANNOUNCE_WAIT * AUTOIP_TICKS_PER_SECOND;
|
---|
416 | LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
|
---|
417 | ("autoip_tmr(): changing state to ANNOUNCING: %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
|
---|
418 | ip4_addr1_16(&netif->autoip->llipaddr), ip4_addr2_16(&netif->autoip->llipaddr),
|
---|
419 | ip4_addr3_16(&netif->autoip->llipaddr), ip4_addr4_16(&netif->autoip->llipaddr)));
|
---|
420 | } else {
|
---|
421 | autoip_arp_probe(netif);
|
---|
422 | LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE,
|
---|
423 | ("autoip_tmr() PROBING Sent Probe\n"));
|
---|
424 | netif->autoip->sent_num++;
|
---|
425 | /* calculate time to wait to next probe */
|
---|
426 | netif->autoip->ttw = (u16_t)((LWIP_AUTOIP_RAND(netif) %
|
---|
427 | ((PROBE_MAX - PROBE_MIN) * AUTOIP_TICKS_PER_SECOND) ) +
|
---|
428 | PROBE_MIN * AUTOIP_TICKS_PER_SECOND);
|
---|
429 | }
|
---|
430 | }
|
---|
431 | break;
|
---|
432 |
|
---|
433 | case AUTOIP_STATE_ANNOUNCING:
|
---|
434 | if (netif->autoip->ttw > 0) {
|
---|
435 | netif->autoip->ttw--;
|
---|
436 | } else {
|
---|
437 | if (netif->autoip->sent_num == 0) {
|
---|
438 | /* We are here the first time, so we waited ANNOUNCE_WAIT seconds
|
---|
439 | * Now we can bind to an IP address and use it.
|
---|
440 | *
|
---|
441 | * autoip_bind calls netif_set_up. This triggers a gratuitous ARP
|
---|
442 | * which counts as an announcement.
|
---|
443 | */
|
---|
444 | autoip_bind(netif);
|
---|
445 | } else {
|
---|
446 | autoip_arp_announce(netif);
|
---|
447 | LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE,
|
---|
448 | ("autoip_tmr() ANNOUNCING Sent Announce\n"));
|
---|
449 | }
|
---|
450 | netif->autoip->ttw = ANNOUNCE_INTERVAL * AUTOIP_TICKS_PER_SECOND;
|
---|
451 | netif->autoip->sent_num++;
|
---|
452 |
|
---|
453 | if (netif->autoip->sent_num >= ANNOUNCE_NUM) {
|
---|
454 | netif->autoip->state = AUTOIP_STATE_BOUND;
|
---|
455 | netif->autoip->sent_num = 0;
|
---|
456 | netif->autoip->ttw = 0;
|
---|
457 | LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
|
---|
458 | ("autoip_tmr(): changing state to BOUND: %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
|
---|
459 | ip4_addr1_16(&netif->autoip->llipaddr), ip4_addr2_16(&netif->autoip->llipaddr),
|
---|
460 | ip4_addr3_16(&netif->autoip->llipaddr), ip4_addr4_16(&netif->autoip->llipaddr)));
|
---|
461 | }
|
---|
462 | }
|
---|
463 | break;
|
---|
464 | }
|
---|
465 | }
|
---|
466 | /* proceed to next network interface */
|
---|
467 | netif = netif->next;
|
---|
468 | }
|
---|
469 | }
|
---|
470 |
|
---|
471 | /**
|
---|
472 | * Handles every incoming ARP Packet, called by etharp_arp_input.
|
---|
473 | *
|
---|
474 | * @param netif network interface to use for autoip processing
|
---|
475 | * @param hdr Incoming ARP packet
|
---|
476 | */
|
---|
477 | void
|
---|
478 | autoip_arp_reply(struct netif *netif, struct etharp_hdr *hdr)
|
---|
479 | {
|
---|
480 | LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE, ("autoip_arp_reply()\n"));
|
---|
481 | if ((netif->autoip != NULL) && (netif->autoip->state != AUTOIP_STATE_OFF)) {
|
---|
482 | /* when ip.src == llipaddr && hw.src != netif->hwaddr
|
---|
483 | *
|
---|
484 | * when probing ip.dst == llipaddr && hw.src != netif->hwaddr
|
---|
485 | * we have a conflict and must solve it
|
---|
486 | */
|
---|
487 | ip_addr_t sipaddr, dipaddr;
|
---|
488 | struct eth_addr netifaddr;
|
---|
489 | ETHADDR16_COPY(netifaddr.addr, netif->hwaddr);
|
---|
490 |
|
---|
491 | /* Copy struct ip_addr2 to aligned ip_addr, to support compilers without
|
---|
492 | * structure packing (not using structure copy which breaks strict-aliasing rules).
|
---|
493 | */
|
---|
494 | IPADDR2_COPY(&sipaddr, &hdr->sipaddr);
|
---|
495 | IPADDR2_COPY(&dipaddr, &hdr->dipaddr);
|
---|
496 |
|
---|
497 | if ((netif->autoip->state == AUTOIP_STATE_PROBING) ||
|
---|
498 | ((netif->autoip->state == AUTOIP_STATE_ANNOUNCING) &&
|
---|
499 | (netif->autoip->sent_num == 0))) {
|
---|
500 | /* RFC 3927 Section 2.2.1:
|
---|
501 | * from beginning to after ANNOUNCE_WAIT
|
---|
502 | * seconds we have a conflict if
|
---|
503 | * ip.src == llipaddr OR
|
---|
504 | * ip.dst == llipaddr && hw.src != own hwaddr
|
---|
505 | */
|
---|
506 | if ((ip_addr_cmp(&sipaddr, &netif->autoip->llipaddr)) ||
|
---|
507 | (ip_addr_cmp(&dipaddr, &netif->autoip->llipaddr) &&
|
---|
508 | !eth_addr_cmp(&netifaddr, &hdr->shwaddr))) {
|
---|
509 | LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE | LWIP_DBG_LEVEL_WARNING,
|
---|
510 | ("autoip_arp_reply(): Probe Conflict detected\n"));
|
---|
511 | autoip_restart(netif);
|
---|
512 | }
|
---|
513 | } else {
|
---|
514 | /* RFC 3927 Section 2.5:
|
---|
515 | * in any state we have a conflict if
|
---|
516 | * ip.src == llipaddr && hw.src != own hwaddr
|
---|
517 | */
|
---|
518 | if (ip_addr_cmp(&sipaddr, &netif->autoip->llipaddr) &&
|
---|
519 | !eth_addr_cmp(&netifaddr, &hdr->shwaddr)) {
|
---|
520 | LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE | LWIP_DBG_LEVEL_WARNING,
|
---|
521 | ("autoip_arp_reply(): Conflicting ARP-Packet detected\n"));
|
---|
522 | autoip_handle_arp_conflict(netif);
|
---|
523 | }
|
---|
524 | }
|
---|
525 | }
|
---|
526 | }
|
---|
527 |
|
---|
528 | #endif /* LWIP_AUTOIP */
|
---|