1 | /**
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2 | * @file
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3 | * Address Resolution Protocol module for IP over Ethernet
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4 | *
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5 | * Functionally, ARP is divided into two parts. The first maps an IP address
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6 | * to a physical address when sending a packet, and the second part answers
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7 | * requests from other machines for our physical address.
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8 | *
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9 | * This implementation complies with RFC 826 (Ethernet ARP). It supports
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10 | * Gratuitious ARP from RFC3220 (IP Mobility Support for IPv4) section 4.6
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11 | * if an interface calls etharp_gratuitous(our_netif) upon address change.
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12 | */
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13 |
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14 | /*
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15 | * Copyright (c) 2001-2003 Swedish Institute of Computer Science.
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16 | * Copyright (c) 2003-2004 Leon Woestenberg <leon.woestenberg@axon.tv>
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17 | * Copyright (c) 2003-2004 Axon Digital Design B.V., The Netherlands.
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18 | * All rights reserved.
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19 | *
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20 | * Redistribution and use in source and binary forms, with or without modification,
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21 | * are permitted provided that the following conditions are met:
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22 | *
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23 | * 1. Redistributions of source code must retain the above copyright notice,
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24 | * this list of conditions and the following disclaimer.
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25 | * 2. Redistributions in binary form must reproduce the above copyright notice,
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26 | * this list of conditions and the following disclaimer in the documentation
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27 | * and/or other materials provided with the distribution.
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28 | * 3. The name of the author may not be used to endorse or promote products
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29 | * derived from this software without specific prior written permission.
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30 | *
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31 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
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32 | * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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33 | * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
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34 | * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
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35 | * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
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36 | * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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37 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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38 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
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39 | * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
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40 | * OF SUCH DAMAGE.
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41 | *
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42 | * This file is part of the lwIP TCP/IP stack.
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43 | *
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44 | */
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45 |
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46 | #include "lwip/opt.h"
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47 |
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48 | #if LWIP_ARP || LWIP_ETHERNET
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49 |
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50 | #include "lwip/ip_addr.h"
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51 | #include "lwip/def.h"
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52 | #include "lwip/ip.h"
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53 | #include "lwip/stats.h"
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54 | #include "lwip/snmp.h"
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55 | #include "lwip/dhcp.h"
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56 | #include "lwip/autoip.h"
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57 | #include "netif/etharp.h"
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58 |
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59 | #if PPPOE_SUPPORT
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60 | #include "netif/ppp_oe.h"
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61 | #endif /* PPPOE_SUPPORT */
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62 |
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63 | #include <string.h>
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64 |
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65 | const struct eth_addr ethbroadcast = {{0xff,0xff,0xff,0xff,0xff,0xff}};
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66 | const struct eth_addr ethzero = {{0,0,0,0,0,0}};
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67 |
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68 | /** The 24-bit IANA multicast OUI is 01-00-5e: */
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69 | #define LL_MULTICAST_ADDR_0 0x01
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70 | #define LL_MULTICAST_ADDR_1 0x00
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71 | #define LL_MULTICAST_ADDR_2 0x5e
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72 |
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73 | #if LWIP_ARP /* don't build if not configured for use in lwipopts.h */
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74 |
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75 | /** the time an ARP entry stays valid after its last update,
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76 | * for ARP_TMR_INTERVAL = 5000, this is
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77 | * (240 * 5) seconds = 20 minutes.
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78 | */
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79 | #define ARP_MAXAGE 240
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80 | /** Re-request a used ARP entry 1 minute before it would expire to prevent
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81 | * breaking a steadily used connection because the ARP entry timed out. */
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82 | #define ARP_AGE_REREQUEST_USED (ARP_MAXAGE - 12)
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83 |
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84 | /** the time an ARP entry stays pending after first request,
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85 | * for ARP_TMR_INTERVAL = 5000, this is
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86 | * (2 * 5) seconds = 10 seconds.
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87 | *
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88 | * @internal Keep this number at least 2, otherwise it might
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89 | * run out instantly if the timeout occurs directly after a request.
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90 | */
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91 | #define ARP_MAXPENDING 2
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92 |
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93 | #define HWTYPE_ETHERNET 1
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94 |
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95 | enum etharp_state {
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96 | ETHARP_STATE_EMPTY = 0,
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97 | ETHARP_STATE_PENDING,
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98 | ETHARP_STATE_STABLE,
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99 | ETHARP_STATE_STABLE_REREQUESTING
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100 | #if ETHARP_SUPPORT_STATIC_ENTRIES
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101 | ,ETHARP_STATE_STATIC
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102 | #endif /* ETHARP_SUPPORT_STATIC_ENTRIES */
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103 | };
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104 |
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105 | struct etharp_entry {
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106 | #if ARP_QUEUEING
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107 | /** Pointer to queue of pending outgoing packets on this ARP entry. */
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108 | struct etharp_q_entry *q;
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109 | #else /* ARP_QUEUEING */
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110 | /** Pointer to a single pending outgoing packet on this ARP entry. */
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111 | struct pbuf *q;
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112 | #endif /* ARP_QUEUEING */
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113 | ip_addr_t ipaddr;
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114 | struct netif *netif;
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115 | struct eth_addr ethaddr;
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116 | u8_t state;
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117 | u8_t ctime;
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118 | };
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119 |
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120 | static struct etharp_entry arp_table[ARP_TABLE_SIZE];
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121 |
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122 | #if !LWIP_NETIF_HWADDRHINT
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123 | static u8_t etharp_cached_entry;
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124 | #endif /* !LWIP_NETIF_HWADDRHINT */
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125 |
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126 | /** Try hard to create a new entry - we want the IP address to appear in
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127 | the cache (even if this means removing an active entry or so). */
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128 | #define ETHARP_FLAG_TRY_HARD 1
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129 | #define ETHARP_FLAG_FIND_ONLY 2
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130 | #if ETHARP_SUPPORT_STATIC_ENTRIES
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131 | #define ETHARP_FLAG_STATIC_ENTRY 4
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132 | #endif /* ETHARP_SUPPORT_STATIC_ENTRIES */
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133 |
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134 | #if LWIP_NETIF_HWADDRHINT
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135 | #define ETHARP_SET_HINT(netif, hint) if (((netif) != NULL) && ((netif)->addr_hint != NULL)) \
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136 | *((netif)->addr_hint) = (hint);
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137 | #else /* LWIP_NETIF_HWADDRHINT */
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138 | #define ETHARP_SET_HINT(netif, hint) (etharp_cached_entry = (hint))
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139 | #endif /* LWIP_NETIF_HWADDRHINT */
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140 |
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141 |
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142 | /* Some checks, instead of etharp_init(): */
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143 | #if (LWIP_ARP && (ARP_TABLE_SIZE > 0x7f))
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144 | #error "ARP_TABLE_SIZE must fit in an s8_t, you have to reduce it in your lwipopts.h"
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145 | #endif
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146 |
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147 |
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148 | #if ARP_QUEUEING
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149 | /**
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150 | * Free a complete queue of etharp entries
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151 | *
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152 | * @param q a qeueue of etharp_q_entry's to free
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153 | */
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154 | static void
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155 | free_etharp_q(struct etharp_q_entry *q)
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156 | {
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157 | struct etharp_q_entry *r;
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158 | LWIP_ASSERT("q != NULL", q != NULL);
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159 | LWIP_ASSERT("q->p != NULL", q->p != NULL);
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160 | while (q) {
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161 | r = q;
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162 | q = q->next;
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163 | LWIP_ASSERT("r->p != NULL", (r->p != NULL));
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164 | pbuf_free(r->p);
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165 | memp_free(MEMP_ARP_QUEUE, r);
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166 | }
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167 | }
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168 | #else /* ARP_QUEUEING */
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169 |
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170 | /** Compatibility define: free the queued pbuf */
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171 | #define free_etharp_q(q) pbuf_free(q)
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172 |
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173 | #endif /* ARP_QUEUEING */
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174 |
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175 | /** Clean up ARP table entries */
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176 | static void
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177 | etharp_free_entry(int i)
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178 | {
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179 | /* remove from SNMP ARP index tree */
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180 | snmp_delete_arpidx_tree(arp_table[i].netif, &arp_table[i].ipaddr);
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181 | /* and empty packet queue */
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182 | if (arp_table[i].q != NULL) {
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183 | /* remove all queued packets */
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184 | LWIP_DEBUGF(ETHARP_DEBUG, ("etharp_free_entry: freeing entry %"U16_F", packet queue %p.\n", (u16_t)i, (void *)(arp_table[i].q)));
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185 | free_etharp_q(arp_table[i].q);
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186 | arp_table[i].q = NULL;
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187 | }
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188 | /* recycle entry for re-use */
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189 | arp_table[i].state = ETHARP_STATE_EMPTY;
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190 | #ifdef LWIP_DEBUG
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191 | /* for debugging, clean out the complete entry */
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192 | arp_table[i].ctime = 0;
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193 | arp_table[i].netif = NULL;
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194 | ip_addr_set_zero(&arp_table[i].ipaddr);
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195 | arp_table[i].ethaddr = ethzero;
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196 | #endif /* LWIP_DEBUG */
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197 | }
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198 |
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199 | /**
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200 | * Clears expired entries in the ARP table.
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201 | *
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202 | * This function should be called every ETHARP_TMR_INTERVAL milliseconds (5 seconds),
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203 | * in order to expire entries in the ARP table.
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204 | */
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205 | void
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206 | etharp_tmr(void)
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207 | {
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208 | u8_t i;
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209 |
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210 | LWIP_DEBUGF(ETHARP_DEBUG, ("etharp_timer\n"));
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211 | /* remove expired entries from the ARP table */
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212 | for (i = 0; i < ARP_TABLE_SIZE; ++i) {
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213 | u8_t state = arp_table[i].state;
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214 | if (state != ETHARP_STATE_EMPTY
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215 | #if ETHARP_SUPPORT_STATIC_ENTRIES
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216 | && (state != ETHARP_STATE_STATIC)
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217 | #endif /* ETHARP_SUPPORT_STATIC_ENTRIES */
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218 | ) {
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219 | arp_table[i].ctime++;
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220 | if ((arp_table[i].ctime >= ARP_MAXAGE) ||
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221 | ((arp_table[i].state == ETHARP_STATE_PENDING) &&
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222 | (arp_table[i].ctime >= ARP_MAXPENDING))) {
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223 | /* pending or stable entry has become old! */
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224 | LWIP_DEBUGF(ETHARP_DEBUG, ("etharp_timer: expired %s entry %"U16_F".\n",
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225 | arp_table[i].state >= ETHARP_STATE_STABLE ? "stable" : "pending", (u16_t)i));
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226 | /* clean up entries that have just been expired */
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227 | etharp_free_entry(i);
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228 | }
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229 | else if (arp_table[i].state == ETHARP_STATE_STABLE_REREQUESTING) {
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230 | /* Reset state to stable, so that the next transmitted packet will
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231 | re-send an ARP request. */
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232 | arp_table[i].state = ETHARP_STATE_STABLE;
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233 | }
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234 | #if ARP_QUEUEING
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235 | /* still pending entry? (not expired) */
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236 | if (arp_table[i].state == ETHARP_STATE_PENDING) {
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237 | /* resend an ARP query here? */
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238 | }
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239 | #endif /* ARP_QUEUEING */
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240 | }
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241 | }
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242 | }
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243 |
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244 | /**
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245 | * Search the ARP table for a matching or new entry.
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246 | *
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247 | * If an IP address is given, return a pending or stable ARP entry that matches
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248 | * the address. If no match is found, create a new entry with this address set,
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249 | * but in state ETHARP_EMPTY. The caller must check and possibly change the
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250 | * state of the returned entry.
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251 | *
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252 | * If ipaddr is NULL, return a initialized new entry in state ETHARP_EMPTY.
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253 | *
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254 | * In all cases, attempt to create new entries from an empty entry. If no
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255 | * empty entries are available and ETHARP_FLAG_TRY_HARD flag is set, recycle
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256 | * old entries. Heuristic choose the least important entry for recycling.
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257 | *
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258 | * @param ipaddr IP address to find in ARP cache, or to add if not found.
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259 | * @param flags @see definition of ETHARP_FLAG_*
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260 | * @param netif netif related to this address (used for NETIF_HWADDRHINT)
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261 | *
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262 | * @return The ARP entry index that matched or is created, ERR_MEM if no
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263 | * entry is found or could be recycled.
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264 | */
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265 | static s8_t
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266 | etharp_find_entry(ip_addr_t *ipaddr, u8_t flags)
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267 | {
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268 | s8_t old_pending = ARP_TABLE_SIZE, old_stable = ARP_TABLE_SIZE;
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269 | s8_t empty = ARP_TABLE_SIZE;
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270 | u8_t i = 0, age_pending = 0, age_stable = 0;
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271 | /* oldest entry with packets on queue */
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272 | s8_t old_queue = ARP_TABLE_SIZE;
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273 | /* its age */
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274 | u8_t age_queue = 0;
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275 |
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276 | /**
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277 | * a) do a search through the cache, remember candidates
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278 | * b) select candidate entry
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279 | * c) create new entry
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280 | */
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281 |
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282 | /* a) in a single search sweep, do all of this
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283 | * 1) remember the first empty entry (if any)
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284 | * 2) remember the oldest stable entry (if any)
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285 | * 3) remember the oldest pending entry without queued packets (if any)
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286 | * 4) remember the oldest pending entry with queued packets (if any)
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287 | * 5) search for a matching IP entry, either pending or stable
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288 | * until 5 matches, or all entries are searched for.
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289 | */
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290 |
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291 | for (i = 0; i < ARP_TABLE_SIZE; ++i) {
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292 | u8_t state = arp_table[i].state;
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293 | /* no empty entry found yet and now we do find one? */
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294 | if ((empty == ARP_TABLE_SIZE) && (state == ETHARP_STATE_EMPTY)) {
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295 | LWIP_DEBUGF(ETHARP_DEBUG, ("etharp_find_entry: found empty entry %"U16_F"\n", (u16_t)i));
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296 | /* remember first empty entry */
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297 | empty = i;
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298 | } else if (state != ETHARP_STATE_EMPTY) {
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299 | LWIP_ASSERT("state == ETHARP_STATE_PENDING || state >= ETHARP_STATE_STABLE",
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300 | state == ETHARP_STATE_PENDING || state >= ETHARP_STATE_STABLE);
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301 | /* if given, does IP address match IP address in ARP entry? */
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302 | if (ipaddr && ip_addr_cmp(ipaddr, &arp_table[i].ipaddr)) {
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303 | LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_find_entry: found matching entry %"U16_F"\n", (u16_t)i));
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304 | /* found exact IP address match, simply bail out */
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305 | return i;
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306 | }
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307 | /* pending entry? */
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308 | if (state == ETHARP_STATE_PENDING) {
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309 | /* pending with queued packets? */
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310 | if (arp_table[i].q != NULL) {
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311 | if (arp_table[i].ctime >= age_queue) {
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312 | old_queue = i;
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313 | age_queue = arp_table[i].ctime;
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314 | }
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315 | } else
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316 | /* pending without queued packets? */
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317 | {
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318 | if (arp_table[i].ctime >= age_pending) {
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319 | old_pending = i;
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320 | age_pending = arp_table[i].ctime;
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321 | }
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322 | }
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323 | /* stable entry? */
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324 | } else if (state >= ETHARP_STATE_STABLE) {
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325 | #if ETHARP_SUPPORT_STATIC_ENTRIES
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326 | /* don't record old_stable for static entries since they never expire */
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327 | if (state < ETHARP_STATE_STATIC)
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328 | #endif /* ETHARP_SUPPORT_STATIC_ENTRIES */
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329 | {
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330 | /* remember entry with oldest stable entry in oldest, its age in maxtime */
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331 | if (arp_table[i].ctime >= age_stable) {
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332 | old_stable = i;
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333 | age_stable = arp_table[i].ctime;
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334 | }
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335 | }
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336 | }
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337 | }
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338 | }
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339 | /* { we have no match } => try to create a new entry */
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340 |
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341 | /* don't create new entry, only search? */
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342 | if (((flags & ETHARP_FLAG_FIND_ONLY) != 0) ||
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343 | /* or no empty entry found and not allowed to recycle? */
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344 | ((empty == ARP_TABLE_SIZE) && ((flags & ETHARP_FLAG_TRY_HARD) == 0))) {
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345 | LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_find_entry: no empty entry found and not allowed to recycle\n"));
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346 | return (s8_t)ERR_MEM;
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347 | }
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348 |
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349 | /* b) choose the least destructive entry to recycle:
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350 | * 1) empty entry
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351 | * 2) oldest stable entry
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352 | * 3) oldest pending entry without queued packets
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353 | * 4) oldest pending entry with queued packets
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354 | *
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355 | * { ETHARP_FLAG_TRY_HARD is set at this point }
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356 | */
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357 |
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358 | /* 1) empty entry available? */
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359 | if (empty < ARP_TABLE_SIZE) {
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360 | i = empty;
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361 | LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_find_entry: selecting empty entry %"U16_F"\n", (u16_t)i));
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362 | } else {
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363 | /* 2) found recyclable stable entry? */
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364 | if (old_stable < ARP_TABLE_SIZE) {
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365 | /* recycle oldest stable*/
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366 | i = old_stable;
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367 | LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_find_entry: selecting oldest stable entry %"U16_F"\n", (u16_t)i));
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368 | /* no queued packets should exist on stable entries */
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369 | LWIP_ASSERT("arp_table[i].q == NULL", arp_table[i].q == NULL);
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370 | /* 3) found recyclable pending entry without queued packets? */
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371 | } else if (old_pending < ARP_TABLE_SIZE) {
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372 | /* recycle oldest pending */
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373 | i = old_pending;
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374 | LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_find_entry: selecting oldest pending entry %"U16_F" (without queue)\n", (u16_t)i));
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375 | /* 4) found recyclable pending entry with queued packets? */
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376 | } else if (old_queue < ARP_TABLE_SIZE) {
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377 | /* recycle oldest pending (queued packets are free in etharp_free_entry) */
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378 | i = old_queue;
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379 | LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_find_entry: selecting oldest pending entry %"U16_F", freeing packet queue %p\n", (u16_t)i, (void *)(arp_table[i].q)));
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380 | /* no empty or recyclable entries found */
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381 | } else {
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382 | LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_find_entry: no empty or recyclable entries found\n"));
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383 | return (s8_t)ERR_MEM;
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384 | }
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385 |
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386 | /* { empty or recyclable entry found } */
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387 | LWIP_ASSERT("i < ARP_TABLE_SIZE", i < ARP_TABLE_SIZE);
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388 | etharp_free_entry(i);
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389 | }
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390 |
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391 | LWIP_ASSERT("i < ARP_TABLE_SIZE", i < ARP_TABLE_SIZE);
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392 | LWIP_ASSERT("arp_table[i].state == ETHARP_STATE_EMPTY",
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393 | arp_table[i].state == ETHARP_STATE_EMPTY);
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394 |
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395 | /* IP address given? */
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396 | if (ipaddr != NULL) {
|
---|
397 | /* set IP address */
|
---|
398 | ip_addr_copy(arp_table[i].ipaddr, *ipaddr);
|
---|
399 | }
|
---|
400 | arp_table[i].ctime = 0;
|
---|
401 | return (err_t)i;
|
---|
402 | }
|
---|
403 |
|
---|
404 | /**
|
---|
405 | * Send an IP packet on the network using netif->linkoutput
|
---|
406 | * The ethernet header is filled in before sending.
|
---|
407 | *
|
---|
408 | * @params netif the lwIP network interface on which to send the packet
|
---|
409 | * @params p the packet to send, p->payload pointing to the (uninitialized) ethernet header
|
---|
410 | * @params src the source MAC address to be copied into the ethernet header
|
---|
411 | * @params dst the destination MAC address to be copied into the ethernet header
|
---|
412 | * @return ERR_OK if the packet was sent, any other err_t on failure
|
---|
413 | */
|
---|
414 | static err_t
|
---|
415 | etharp_send_ip(struct netif *netif, struct pbuf *p, struct eth_addr *src, struct eth_addr *dst)
|
---|
416 | {
|
---|
417 | struct eth_hdr *ethhdr = (struct eth_hdr *)p->payload;
|
---|
418 |
|
---|
419 | LWIP_ASSERT("netif->hwaddr_len must be the same as ETHARP_HWADDR_LEN for etharp!",
|
---|
420 | (netif->hwaddr_len == ETHARP_HWADDR_LEN));
|
---|
421 | ETHADDR32_COPY(ðhdr->dest, dst);
|
---|
422 | ETHADDR16_COPY(ðhdr->src, src);
|
---|
423 | ethhdr->type = PP_HTONS(ETHTYPE_IP);
|
---|
424 | LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_send_ip: sending packet %p\n", (void *)p));
|
---|
425 | /* send the packet */
|
---|
426 | return netif->linkoutput(netif, p);
|
---|
427 | }
|
---|
428 |
|
---|
429 | /**
|
---|
430 | * Update (or insert) a IP/MAC address pair in the ARP cache.
|
---|
431 | *
|
---|
432 | * If a pending entry is resolved, any queued packets will be sent
|
---|
433 | * at this point.
|
---|
434 | *
|
---|
435 | * @param netif netif related to this entry (used for NETIF_ADDRHINT)
|
---|
436 | * @param ipaddr IP address of the inserted ARP entry.
|
---|
437 | * @param ethaddr Ethernet address of the inserted ARP entry.
|
---|
438 | * @param flags @see definition of ETHARP_FLAG_*
|
---|
439 | *
|
---|
440 | * @return
|
---|
441 | * - ERR_OK Succesfully updated ARP cache.
|
---|
442 | * - ERR_MEM If we could not add a new ARP entry when ETHARP_FLAG_TRY_HARD was set.
|
---|
443 | * - ERR_ARG Non-unicast address given, those will not appear in ARP cache.
|
---|
444 | *
|
---|
445 | * @see pbuf_free()
|
---|
446 | */
|
---|
447 | static err_t
|
---|
448 | etharp_update_arp_entry(struct netif *netif, ip_addr_t *ipaddr, struct eth_addr *ethaddr, u8_t flags)
|
---|
449 | {
|
---|
450 | s8_t i;
|
---|
451 | LWIP_ASSERT("netif->hwaddr_len == ETHARP_HWADDR_LEN", netif->hwaddr_len == ETHARP_HWADDR_LEN);
|
---|
452 | LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_update_arp_entry: %"U16_F".%"U16_F".%"U16_F".%"U16_F" - %02"X16_F":%02"X16_F":%02"X16_F":%02"X16_F":%02"X16_F":%02"X16_F"\n",
|
---|
453 | ip4_addr1_16(ipaddr), ip4_addr2_16(ipaddr), ip4_addr3_16(ipaddr), ip4_addr4_16(ipaddr),
|
---|
454 | ethaddr->addr[0], ethaddr->addr[1], ethaddr->addr[2],
|
---|
455 | ethaddr->addr[3], ethaddr->addr[4], ethaddr->addr[5]));
|
---|
456 | /* non-unicast address? */
|
---|
457 | if (ip_addr_isany(ipaddr) ||
|
---|
458 | ip_addr_isbroadcast(ipaddr, netif) ||
|
---|
459 | ip_addr_ismulticast(ipaddr)) {
|
---|
460 | LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_update_arp_entry: will not add non-unicast IP address to ARP cache\n"));
|
---|
461 | return ERR_ARG;
|
---|
462 | }
|
---|
463 | /* find or create ARP entry */
|
---|
464 | i = etharp_find_entry(ipaddr, flags);
|
---|
465 | /* bail out if no entry could be found */
|
---|
466 | if (i < 0) {
|
---|
467 | return (err_t)i;
|
---|
468 | }
|
---|
469 |
|
---|
470 | #if ETHARP_SUPPORT_STATIC_ENTRIES
|
---|
471 | if (flags & ETHARP_FLAG_STATIC_ENTRY) {
|
---|
472 | /* record static type */
|
---|
473 | arp_table[i].state = ETHARP_STATE_STATIC;
|
---|
474 | } else
|
---|
475 | #endif /* ETHARP_SUPPORT_STATIC_ENTRIES */
|
---|
476 | {
|
---|
477 | /* mark it stable */
|
---|
478 | arp_table[i].state = ETHARP_STATE_STABLE;
|
---|
479 | }
|
---|
480 |
|
---|
481 | /* record network interface */
|
---|
482 | arp_table[i].netif = netif;
|
---|
483 | /* insert in SNMP ARP index tree */
|
---|
484 | snmp_insert_arpidx_tree(netif, &arp_table[i].ipaddr);
|
---|
485 |
|
---|
486 | LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_update_arp_entry: updating stable entry %"S16_F"\n", (s16_t)i));
|
---|
487 | /* update address */
|
---|
488 | ETHADDR32_COPY(&arp_table[i].ethaddr, ethaddr);
|
---|
489 | /* reset time stamp */
|
---|
490 | arp_table[i].ctime = 0;
|
---|
491 | /* this is where we will send out queued packets! */
|
---|
492 | #if ARP_QUEUEING
|
---|
493 | while (arp_table[i].q != NULL) {
|
---|
494 | struct pbuf *p;
|
---|
495 | /* remember remainder of queue */
|
---|
496 | struct etharp_q_entry *q = arp_table[i].q;
|
---|
497 | /* pop first item off the queue */
|
---|
498 | arp_table[i].q = q->next;
|
---|
499 | /* get the packet pointer */
|
---|
500 | p = q->p;
|
---|
501 | /* now queue entry can be freed */
|
---|
502 | memp_free(MEMP_ARP_QUEUE, q);
|
---|
503 | #else /* ARP_QUEUEING */
|
---|
504 | if (arp_table[i].q != NULL) {
|
---|
505 | struct pbuf *p = arp_table[i].q;
|
---|
506 | arp_table[i].q = NULL;
|
---|
507 | #endif /* ARP_QUEUEING */
|
---|
508 | /* send the queued IP packet */
|
---|
509 | etharp_send_ip(netif, p, (struct eth_addr*)(netif->hwaddr), ethaddr);
|
---|
510 | /* free the queued IP packet */
|
---|
511 | pbuf_free(p);
|
---|
512 | }
|
---|
513 | return ERR_OK;
|
---|
514 | }
|
---|
515 |
|
---|
516 | #if ETHARP_SUPPORT_STATIC_ENTRIES
|
---|
517 | /** Add a new static entry to the ARP table. If an entry exists for the
|
---|
518 | * specified IP address, this entry is overwritten.
|
---|
519 | * If packets are queued for the specified IP address, they are sent out.
|
---|
520 | *
|
---|
521 | * @param ipaddr IP address for the new static entry
|
---|
522 | * @param ethaddr ethernet address for the new static entry
|
---|
523 | * @return @see return values of etharp_add_static_entry
|
---|
524 | */
|
---|
525 | err_t
|
---|
526 | etharp_add_static_entry(ip_addr_t *ipaddr, struct eth_addr *ethaddr)
|
---|
527 | {
|
---|
528 | struct netif *netif;
|
---|
529 | LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_add_static_entry: %"U16_F".%"U16_F".%"U16_F".%"U16_F" - %02"X16_F":%02"X16_F":%02"X16_F":%02"X16_F":%02"X16_F":%02"X16_F"\n",
|
---|
530 | ip4_addr1_16(ipaddr), ip4_addr2_16(ipaddr), ip4_addr3_16(ipaddr), ip4_addr4_16(ipaddr),
|
---|
531 | ethaddr->addr[0], ethaddr->addr[1], ethaddr->addr[2],
|
---|
532 | ethaddr->addr[3], ethaddr->addr[4], ethaddr->addr[5]));
|
---|
533 |
|
---|
534 | netif = ip_route(ipaddr);
|
---|
535 | if (netif == NULL) {
|
---|
536 | return ERR_RTE;
|
---|
537 | }
|
---|
538 |
|
---|
539 | return etharp_update_arp_entry(netif, ipaddr, ethaddr, ETHARP_FLAG_TRY_HARD | ETHARP_FLAG_STATIC_ENTRY);
|
---|
540 | }
|
---|
541 |
|
---|
542 | /** Remove a static entry from the ARP table previously added with a call to
|
---|
543 | * etharp_add_static_entry.
|
---|
544 | *
|
---|
545 | * @param ipaddr IP address of the static entry to remove
|
---|
546 | * @return ERR_OK: entry removed
|
---|
547 | * ERR_MEM: entry wasn't found
|
---|
548 | * ERR_ARG: entry wasn't a static entry but a dynamic one
|
---|
549 | */
|
---|
550 | err_t
|
---|
551 | etharp_remove_static_entry(ip_addr_t *ipaddr)
|
---|
552 | {
|
---|
553 | s8_t i;
|
---|
554 | LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_remove_static_entry: %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
|
---|
555 | ip4_addr1_16(ipaddr), ip4_addr2_16(ipaddr), ip4_addr3_16(ipaddr), ip4_addr4_16(ipaddr)));
|
---|
556 |
|
---|
557 | /* find or create ARP entry */
|
---|
558 | i = etharp_find_entry(ipaddr, ETHARP_FLAG_FIND_ONLY);
|
---|
559 | /* bail out if no entry could be found */
|
---|
560 | if (i < 0) {
|
---|
561 | return (err_t)i;
|
---|
562 | }
|
---|
563 |
|
---|
564 | if (arp_table[i].state != ETHARP_STATE_STATIC) {
|
---|
565 | /* entry wasn't a static entry, cannot remove it */
|
---|
566 | return ERR_ARG;
|
---|
567 | }
|
---|
568 | /* entry found, free it */
|
---|
569 | etharp_free_entry(i);
|
---|
570 | return ERR_OK;
|
---|
571 | }
|
---|
572 | #endif /* ETHARP_SUPPORT_STATIC_ENTRIES */
|
---|
573 |
|
---|
574 | /**
|
---|
575 | * Remove all ARP table entries of the specified netif.
|
---|
576 | *
|
---|
577 | * @param netif points to a network interface
|
---|
578 | */
|
---|
579 | void etharp_cleanup_netif(struct netif *netif)
|
---|
580 | {
|
---|
581 | u8_t i;
|
---|
582 |
|
---|
583 | for (i = 0; i < ARP_TABLE_SIZE; ++i) {
|
---|
584 | u8_t state = arp_table[i].state;
|
---|
585 | if ((state != ETHARP_STATE_EMPTY) && (arp_table[i].netif == netif)) {
|
---|
586 | etharp_free_entry(i);
|
---|
587 | }
|
---|
588 | }
|
---|
589 | }
|
---|
590 |
|
---|
591 | /**
|
---|
592 | * Finds (stable) ethernet/IP address pair from ARP table
|
---|
593 | * using interface and IP address index.
|
---|
594 | * @note the addresses in the ARP table are in network order!
|
---|
595 | *
|
---|
596 | * @param netif points to interface index
|
---|
597 | * @param ipaddr points to the (network order) IP address index
|
---|
598 | * @param eth_ret points to return pointer
|
---|
599 | * @param ip_ret points to return pointer
|
---|
600 | * @return table index if found, -1 otherwise
|
---|
601 | */
|
---|
602 | s8_t
|
---|
603 | etharp_find_addr(struct netif *netif, ip_addr_t *ipaddr,
|
---|
604 | struct eth_addr **eth_ret, ip_addr_t **ip_ret)
|
---|
605 | {
|
---|
606 | s8_t i;
|
---|
607 |
|
---|
608 | LWIP_ASSERT("eth_ret != NULL && ip_ret != NULL",
|
---|
609 | eth_ret != NULL && ip_ret != NULL);
|
---|
610 |
|
---|
611 | LWIP_UNUSED_ARG(netif);
|
---|
612 |
|
---|
613 | i = etharp_find_entry(ipaddr, ETHARP_FLAG_FIND_ONLY);
|
---|
614 | if((i >= 0) && (arp_table[i].state >= ETHARP_STATE_STABLE)) {
|
---|
615 | *eth_ret = &arp_table[i].ethaddr;
|
---|
616 | *ip_ret = &arp_table[i].ipaddr;
|
---|
617 | return i;
|
---|
618 | }
|
---|
619 | return -1;
|
---|
620 | }
|
---|
621 |
|
---|
622 | #if ETHARP_TRUST_IP_MAC
|
---|
623 | /**
|
---|
624 | * Updates the ARP table using the given IP packet.
|
---|
625 | *
|
---|
626 | * Uses the incoming IP packet's source address to update the
|
---|
627 | * ARP cache for the local network. The function does not alter
|
---|
628 | * or free the packet. This function must be called before the
|
---|
629 | * packet p is passed to the IP layer.
|
---|
630 | *
|
---|
631 | * @param netif The lwIP network interface on which the IP packet pbuf arrived.
|
---|
632 | * @param p The IP packet that arrived on netif.
|
---|
633 | *
|
---|
634 | * @return NULL
|
---|
635 | *
|
---|
636 | * @see pbuf_free()
|
---|
637 | */
|
---|
638 | static void
|
---|
639 | etharp_ip_input(struct netif *netif, struct pbuf *p)
|
---|
640 | {
|
---|
641 | struct eth_hdr *ethhdr;
|
---|
642 | struct ip_hdr *iphdr;
|
---|
643 | ip_addr_t iphdr_src;
|
---|
644 | LWIP_ERROR("netif != NULL", (netif != NULL), return;);
|
---|
645 |
|
---|
646 | /* Only insert an entry if the source IP address of the
|
---|
647 | incoming IP packet comes from a host on the local network. */
|
---|
648 | ethhdr = (struct eth_hdr *)p->payload;
|
---|
649 | iphdr = (struct ip_hdr *)((u8_t*)ethhdr + SIZEOF_ETH_HDR);
|
---|
650 | #if ETHARP_SUPPORT_VLAN
|
---|
651 | if (ethhdr->type == PP_HTONS(ETHTYPE_VLAN)) {
|
---|
652 | iphdr = (struct ip_hdr *)((u8_t*)ethhdr + SIZEOF_ETH_HDR + SIZEOF_VLAN_HDR);
|
---|
653 | }
|
---|
654 | #endif /* ETHARP_SUPPORT_VLAN */
|
---|
655 |
|
---|
656 | ip_addr_copy(iphdr_src, iphdr->src);
|
---|
657 |
|
---|
658 | /* source is not on the local network? */
|
---|
659 | if (!ip_addr_netcmp(&iphdr_src, &(netif->ip_addr), &(netif->netmask))) {
|
---|
660 | /* do nothing */
|
---|
661 | return;
|
---|
662 | }
|
---|
663 |
|
---|
664 | LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_ip_input: updating ETHARP table.\n"));
|
---|
665 | /* update the source IP address in the cache, if present */
|
---|
666 | /* @todo We could use ETHARP_FLAG_TRY_HARD if we think we are going to talk
|
---|
667 | * back soon (for example, if the destination IP address is ours. */
|
---|
668 | etharp_update_arp_entry(netif, &iphdr_src, &(ethhdr->src), ETHARP_FLAG_FIND_ONLY);
|
---|
669 | }
|
---|
670 | #endif /* ETHARP_TRUST_IP_MAC */
|
---|
671 |
|
---|
672 | /**
|
---|
673 | * Responds to ARP requests to us. Upon ARP replies to us, add entry to cache
|
---|
674 | * send out queued IP packets. Updates cache with snooped address pairs.
|
---|
675 | *
|
---|
676 | * Should be called for incoming ARP packets. The pbuf in the argument
|
---|
677 | * is freed by this function.
|
---|
678 | *
|
---|
679 | * @param netif The lwIP network interface on which the ARP packet pbuf arrived.
|
---|
680 | * @param ethaddr Ethernet address of netif.
|
---|
681 | * @param p The ARP packet that arrived on netif. Is freed by this function.
|
---|
682 | *
|
---|
683 | * @return NULL
|
---|
684 | *
|
---|
685 | * @see pbuf_free()
|
---|
686 | */
|
---|
687 | static void
|
---|
688 | etharp_arp_input(struct netif *netif, struct eth_addr *ethaddr, struct pbuf *p)
|
---|
689 | {
|
---|
690 | struct etharp_hdr *hdr;
|
---|
691 | struct eth_hdr *ethhdr;
|
---|
692 | /* these are aligned properly, whereas the ARP header fields might not be */
|
---|
693 | ip_addr_t sipaddr, dipaddr;
|
---|
694 | u8_t for_us;
|
---|
695 | #if LWIP_AUTOIP
|
---|
696 | const u8_t * ethdst_hwaddr;
|
---|
697 | #endif /* LWIP_AUTOIP */
|
---|
698 |
|
---|
699 | LWIP_ERROR("netif != NULL", (netif != NULL), return;);
|
---|
700 |
|
---|
701 | /* drop short ARP packets: we have to check for p->len instead of p->tot_len here
|
---|
702 | since a struct etharp_hdr is pointed to p->payload, so it musn't be chained! */
|
---|
703 | if (p->len < SIZEOF_ETHARP_PACKET) {
|
---|
704 | LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING,
|
---|
705 | ("etharp_arp_input: packet dropped, too short (%"S16_F"/%"S16_F")\n", p->tot_len,
|
---|
706 | (s16_t)SIZEOF_ETHARP_PACKET));
|
---|
707 | ETHARP_STATS_INC(etharp.lenerr);
|
---|
708 | ETHARP_STATS_INC(etharp.drop);
|
---|
709 | pbuf_free(p);
|
---|
710 | return;
|
---|
711 | }
|
---|
712 |
|
---|
713 | ethhdr = (struct eth_hdr *)p->payload;
|
---|
714 | hdr = (struct etharp_hdr *)((u8_t*)ethhdr + SIZEOF_ETH_HDR);
|
---|
715 | #if ETHARP_SUPPORT_VLAN
|
---|
716 | if (ethhdr->type == PP_HTONS(ETHTYPE_VLAN)) {
|
---|
717 | hdr = (struct etharp_hdr *)(((u8_t*)ethhdr) + SIZEOF_ETH_HDR + SIZEOF_VLAN_HDR);
|
---|
718 | }
|
---|
719 | #endif /* ETHARP_SUPPORT_VLAN */
|
---|
720 |
|
---|
721 | /* RFC 826 "Packet Reception": */
|
---|
722 | if ((hdr->hwtype != PP_HTONS(HWTYPE_ETHERNET)) ||
|
---|
723 | (hdr->hwlen != ETHARP_HWADDR_LEN) ||
|
---|
724 | (hdr->protolen != sizeof(ip_addr_t)) ||
|
---|
725 | (hdr->proto != PP_HTONS(ETHTYPE_IP))) {
|
---|
726 | LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING,
|
---|
727 | ("etharp_arp_input: packet dropped, wrong hw type, hwlen, proto, protolen or ethernet type (%"U16_F"/%"U16_F"/%"U16_F"/%"U16_F")\n",
|
---|
728 | hdr->hwtype, hdr->hwlen, hdr->proto, hdr->protolen));
|
---|
729 | ETHARP_STATS_INC(etharp.proterr);
|
---|
730 | ETHARP_STATS_INC(etharp.drop);
|
---|
731 | pbuf_free(p);
|
---|
732 | return;
|
---|
733 | }
|
---|
734 | ETHARP_STATS_INC(etharp.recv);
|
---|
735 |
|
---|
736 | #if LWIP_AUTOIP
|
---|
737 | /* We have to check if a host already has configured our random
|
---|
738 | * created link local address and continously check if there is
|
---|
739 | * a host with this IP-address so we can detect collisions */
|
---|
740 | autoip_arp_reply(netif, hdr);
|
---|
741 | #endif /* LWIP_AUTOIP */
|
---|
742 |
|
---|
743 | /* Copy struct ip_addr2 to aligned ip_addr, to support compilers without
|
---|
744 | * structure packing (not using structure copy which breaks strict-aliasing rules). */
|
---|
745 | IPADDR2_COPY(&sipaddr, &hdr->sipaddr);
|
---|
746 | IPADDR2_COPY(&dipaddr, &hdr->dipaddr);
|
---|
747 |
|
---|
748 | /* this interface is not configured? */
|
---|
749 | if (ip_addr_isany(&netif->ip_addr)) {
|
---|
750 | for_us = 0;
|
---|
751 | } else {
|
---|
752 | /* ARP packet directed to us? */
|
---|
753 | for_us = (u8_t)ip_addr_cmp(&dipaddr, &(netif->ip_addr));
|
---|
754 | }
|
---|
755 |
|
---|
756 | /* ARP message directed to us?
|
---|
757 | -> add IP address in ARP cache; assume requester wants to talk to us,
|
---|
758 | can result in directly sending the queued packets for this host.
|
---|
759 | ARP message not directed to us?
|
---|
760 | -> update the source IP address in the cache, if present */
|
---|
761 | etharp_update_arp_entry(netif, &sipaddr, &(hdr->shwaddr),
|
---|
762 | for_us ? ETHARP_FLAG_TRY_HARD : ETHARP_FLAG_FIND_ONLY);
|
---|
763 |
|
---|
764 | /* now act on the message itself */
|
---|
765 | switch (hdr->opcode) {
|
---|
766 | /* ARP request? */
|
---|
767 | case PP_HTONS(ARP_REQUEST):
|
---|
768 | /* ARP request. If it asked for our address, we send out a
|
---|
769 | * reply. In any case, we time-stamp any existing ARP entry,
|
---|
770 | * and possiby send out an IP packet that was queued on it. */
|
---|
771 |
|
---|
772 | LWIP_DEBUGF (ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_arp_input: incoming ARP request\n"));
|
---|
773 | /* ARP request for our address? */
|
---|
774 | if (for_us) {
|
---|
775 |
|
---|
776 | LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_arp_input: replying to ARP request for our IP address\n"));
|
---|
777 | /* Re-use pbuf to send ARP reply.
|
---|
778 | Since we are re-using an existing pbuf, we can't call etharp_raw since
|
---|
779 | that would allocate a new pbuf. */
|
---|
780 | hdr->opcode = htons(ARP_REPLY);
|
---|
781 |
|
---|
782 | IPADDR2_COPY(&hdr->dipaddr, &hdr->sipaddr);
|
---|
783 | IPADDR2_COPY(&hdr->sipaddr, &netif->ip_addr);
|
---|
784 |
|
---|
785 | LWIP_ASSERT("netif->hwaddr_len must be the same as ETHARP_HWADDR_LEN for etharp!",
|
---|
786 | (netif->hwaddr_len == ETHARP_HWADDR_LEN));
|
---|
787 | #if LWIP_AUTOIP
|
---|
788 | /* If we are using Link-Local, all ARP packets that contain a Link-Local
|
---|
789 | * 'sender IP address' MUST be sent using link-layer broadcast instead of
|
---|
790 | * link-layer unicast. (See RFC3927 Section 2.5, last paragraph) */
|
---|
791 | ethdst_hwaddr = ip_addr_islinklocal(&netif->ip_addr) ? (u8_t*)(ethbroadcast.addr) : hdr->shwaddr.addr;
|
---|
792 | #endif /* LWIP_AUTOIP */
|
---|
793 |
|
---|
794 | ETHADDR16_COPY(&hdr->dhwaddr, &hdr->shwaddr);
|
---|
795 | #if LWIP_AUTOIP
|
---|
796 | ETHADDR16_COPY(ðhdr->dest, ethdst_hwaddr);
|
---|
797 | #else /* LWIP_AUTOIP */
|
---|
798 | ETHADDR16_COPY(ðhdr->dest, &hdr->shwaddr);
|
---|
799 | #endif /* LWIP_AUTOIP */
|
---|
800 | ETHADDR16_COPY(&hdr->shwaddr, ethaddr);
|
---|
801 | ETHADDR16_COPY(ðhdr->src, ethaddr);
|
---|
802 |
|
---|
803 | /* hwtype, hwaddr_len, proto, protolen and the type in the ethernet header
|
---|
804 | are already correct, we tested that before */
|
---|
805 |
|
---|
806 | /* return ARP reply */
|
---|
807 | netif->linkoutput(netif, p);
|
---|
808 | /* we are not configured? */
|
---|
809 | } else if (ip_addr_isany(&netif->ip_addr)) {
|
---|
810 | /* { for_us == 0 and netif->ip_addr.addr == 0 } */
|
---|
811 | LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_arp_input: we are unconfigured, ARP request ignored.\n"));
|
---|
812 | /* request was not directed to us */
|
---|
813 | } else {
|
---|
814 | /* { for_us == 0 and netif->ip_addr.addr != 0 } */
|
---|
815 | LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_arp_input: ARP request was not for us.\n"));
|
---|
816 | }
|
---|
817 | break;
|
---|
818 | case PP_HTONS(ARP_REPLY):
|
---|
819 | /* ARP reply. We already updated the ARP cache earlier. */
|
---|
820 | LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_arp_input: incoming ARP reply\n"));
|
---|
821 | #if (LWIP_DHCP && DHCP_DOES_ARP_CHECK)
|
---|
822 | /* DHCP wants to know about ARP replies from any host with an
|
---|
823 | * IP address also offered to us by the DHCP server. We do not
|
---|
824 | * want to take a duplicate IP address on a single network.
|
---|
825 | * @todo How should we handle redundant (fail-over) interfaces? */
|
---|
826 | dhcp_arp_reply(netif, &sipaddr);
|
---|
827 | #endif /* (LWIP_DHCP && DHCP_DOES_ARP_CHECK) */
|
---|
828 | break;
|
---|
829 | default:
|
---|
830 | LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_arp_input: ARP unknown opcode type %"S16_F"\n", htons(hdr->opcode)));
|
---|
831 | ETHARP_STATS_INC(etharp.err);
|
---|
832 | break;
|
---|
833 | }
|
---|
834 | /* free ARP packet */
|
---|
835 | pbuf_free(p);
|
---|
836 | }
|
---|
837 |
|
---|
838 | /** Just a small helper function that sends a pbuf to an ethernet address
|
---|
839 | * in the arp_table specified by the index 'arp_idx'.
|
---|
840 | */
|
---|
841 | static err_t
|
---|
842 | etharp_output_to_arp_index(struct netif *netif, struct pbuf *q, u8_t arp_idx)
|
---|
843 | {
|
---|
844 | LWIP_ASSERT("arp_table[arp_idx].state >= ETHARP_STATE_STABLE",
|
---|
845 | arp_table[arp_idx].state >= ETHARP_STATE_STABLE);
|
---|
846 | /* if arp table entry is about to expire: re-request it,
|
---|
847 | but only if its state is ETHARP_STATE_STABLE to prevent flooding the
|
---|
848 | network with ARP requests if this address is used frequently. */
|
---|
849 | if ((arp_table[arp_idx].state == ETHARP_STATE_STABLE) &&
|
---|
850 | (arp_table[arp_idx].ctime >= ARP_AGE_REREQUEST_USED)) {
|
---|
851 | if (etharp_request(netif, &arp_table[arp_idx].ipaddr) == ERR_OK) {
|
---|
852 | arp_table[arp_idx].state = ETHARP_STATE_STABLE_REREQUESTING;
|
---|
853 | }
|
---|
854 | }
|
---|
855 |
|
---|
856 | return etharp_send_ip(netif, q, (struct eth_addr*)(netif->hwaddr),
|
---|
857 | &arp_table[arp_idx].ethaddr);
|
---|
858 | }
|
---|
859 |
|
---|
860 | /**
|
---|
861 | * Resolve and fill-in Ethernet address header for outgoing IP packet.
|
---|
862 | *
|
---|
863 | * For IP multicast and broadcast, corresponding Ethernet addresses
|
---|
864 | * are selected and the packet is transmitted on the link.
|
---|
865 | *
|
---|
866 | * For unicast addresses, the packet is submitted to etharp_query(). In
|
---|
867 | * case the IP address is outside the local network, the IP address of
|
---|
868 | * the gateway is used.
|
---|
869 | *
|
---|
870 | * @param netif The lwIP network interface which the IP packet will be sent on.
|
---|
871 | * @param q The pbuf(s) containing the IP packet to be sent.
|
---|
872 | * @param ipaddr The IP address of the packet destination.
|
---|
873 | *
|
---|
874 | * @return
|
---|
875 | * - ERR_RTE No route to destination (no gateway to external networks),
|
---|
876 | * or the return type of either etharp_query() or etharp_send_ip().
|
---|
877 | */
|
---|
878 | err_t
|
---|
879 | etharp_output(struct netif *netif, struct pbuf *q, ip_addr_t *ipaddr)
|
---|
880 | {
|
---|
881 | struct eth_addr *dest;
|
---|
882 | struct eth_addr mcastaddr;
|
---|
883 | ip_addr_t *dst_addr = ipaddr;
|
---|
884 |
|
---|
885 | LWIP_ASSERT("netif != NULL", netif != NULL);
|
---|
886 | LWIP_ASSERT("q != NULL", q != NULL);
|
---|
887 | LWIP_ASSERT("ipaddr != NULL", ipaddr != NULL);
|
---|
888 |
|
---|
889 | /* make room for Ethernet header - should not fail */
|
---|
890 | if (pbuf_header(q, sizeof(struct eth_hdr)) != 0) {
|
---|
891 | /* bail out */
|
---|
892 | LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS,
|
---|
893 | ("etharp_output: could not allocate room for header.\n"));
|
---|
894 | LINK_STATS_INC(link.lenerr);
|
---|
895 | return ERR_BUF;
|
---|
896 | }
|
---|
897 |
|
---|
898 | /* Determine on destination hardware address. Broadcasts and multicasts
|
---|
899 | * are special, other IP addresses are looked up in the ARP table. */
|
---|
900 |
|
---|
901 | /* broadcast destination IP address? */
|
---|
902 | if (ip_addr_isbroadcast(ipaddr, netif)) {
|
---|
903 | /* broadcast on Ethernet also */
|
---|
904 | dest = (struct eth_addr *)ðbroadcast;
|
---|
905 | /* multicast destination IP address? */
|
---|
906 | } else if (ip_addr_ismulticast(ipaddr)) {
|
---|
907 | /* Hash IP multicast address to MAC address.*/
|
---|
908 | mcastaddr.addr[0] = LL_MULTICAST_ADDR_0;
|
---|
909 | mcastaddr.addr[1] = LL_MULTICAST_ADDR_1;
|
---|
910 | mcastaddr.addr[2] = LL_MULTICAST_ADDR_2;
|
---|
911 | mcastaddr.addr[3] = ip4_addr2(ipaddr) & 0x7f;
|
---|
912 | mcastaddr.addr[4] = ip4_addr3(ipaddr);
|
---|
913 | mcastaddr.addr[5] = ip4_addr4(ipaddr);
|
---|
914 | /* destination Ethernet address is multicast */
|
---|
915 | dest = &mcastaddr;
|
---|
916 | /* unicast destination IP address? */
|
---|
917 | } else {
|
---|
918 | s8_t i;
|
---|
919 | /* outside local network? if so, this can neither be a global broadcast nor
|
---|
920 | a subnet broadcast. */
|
---|
921 | if (!ip_addr_netcmp(ipaddr, &(netif->ip_addr), &(netif->netmask)) &&
|
---|
922 | !ip_addr_islinklocal(ipaddr)) {
|
---|
923 | #if LWIP_AUTOIP
|
---|
924 | struct ip_hdr *iphdr = (struct ip_hdr*)((u8_t*)q->payload +
|
---|
925 | sizeof(struct eth_hdr));
|
---|
926 | /* According to RFC 3297, chapter 2.6.2 (Forwarding Rules), a packet with
|
---|
927 | a link-local source address must always be "directly to its destination
|
---|
928 | on the same physical link. The host MUST NOT send the packet to any
|
---|
929 | router for forwarding". */
|
---|
930 | if (!ip_addr_islinklocal(&iphdr->src))
|
---|
931 | #endif /* LWIP_AUTOIP */
|
---|
932 | {
|
---|
933 | /* interface has default gateway? */
|
---|
934 | if (!ip_addr_isany(&netif->gw)) {
|
---|
935 | /* send to hardware address of default gateway IP address */
|
---|
936 | dst_addr = &(netif->gw);
|
---|
937 | /* no default gateway available */
|
---|
938 | } else {
|
---|
939 | /* no route to destination error (default gateway missing) */
|
---|
940 | return ERR_RTE;
|
---|
941 | }
|
---|
942 | }
|
---|
943 | }
|
---|
944 | #if LWIP_NETIF_HWADDRHINT
|
---|
945 | if (netif->addr_hint != NULL) {
|
---|
946 | /* per-pcb cached entry was given */
|
---|
947 | u8_t etharp_cached_entry = *(netif->addr_hint);
|
---|
948 | if (etharp_cached_entry < ARP_TABLE_SIZE) {
|
---|
949 | #endif /* LWIP_NETIF_HWADDRHINT */
|
---|
950 | if ((arp_table[etharp_cached_entry].state >= ETHARP_STATE_STABLE) &&
|
---|
951 | (ip_addr_cmp(dst_addr, &arp_table[etharp_cached_entry].ipaddr))) {
|
---|
952 | /* the per-pcb-cached entry is stable and the right one! */
|
---|
953 | ETHARP_STATS_INC(etharp.cachehit);
|
---|
954 | return etharp_output_to_arp_index(netif, q, etharp_cached_entry);
|
---|
955 | }
|
---|
956 | #if LWIP_NETIF_HWADDRHINT
|
---|
957 | }
|
---|
958 | }
|
---|
959 | #endif /* LWIP_NETIF_HWADDRHINT */
|
---|
960 |
|
---|
961 | /* find stable entry: do this here since this is a critical path for
|
---|
962 | throughput and etharp_find_entry() is kind of slow */
|
---|
963 | for (i = 0; i < ARP_TABLE_SIZE; i++) {
|
---|
964 | if ((arp_table[i].state >= ETHARP_STATE_STABLE) &&
|
---|
965 | (ip_addr_cmp(dst_addr, &arp_table[i].ipaddr))) {
|
---|
966 | /* found an existing, stable entry */
|
---|
967 | ETHARP_SET_HINT(netif, i);
|
---|
968 | return etharp_output_to_arp_index(netif, q, i);
|
---|
969 | }
|
---|
970 | }
|
---|
971 | /* no stable entry found, use the (slower) query function:
|
---|
972 | queue on destination Ethernet address belonging to ipaddr */
|
---|
973 | return etharp_query(netif, dst_addr, q);
|
---|
974 | }
|
---|
975 |
|
---|
976 | /* continuation for multicast/broadcast destinations */
|
---|
977 | /* obtain source Ethernet address of the given interface */
|
---|
978 | /* send packet directly on the link */
|
---|
979 | return etharp_send_ip(netif, q, (struct eth_addr*)(netif->hwaddr), dest);
|
---|
980 | }
|
---|
981 |
|
---|
982 | /**
|
---|
983 | * Send an ARP request for the given IP address and/or queue a packet.
|
---|
984 | *
|
---|
985 | * If the IP address was not yet in the cache, a pending ARP cache entry
|
---|
986 | * is added and an ARP request is sent for the given address. The packet
|
---|
987 | * is queued on this entry.
|
---|
988 | *
|
---|
989 | * If the IP address was already pending in the cache, a new ARP request
|
---|
990 | * is sent for the given address. The packet is queued on this entry.
|
---|
991 | *
|
---|
992 | * If the IP address was already stable in the cache, and a packet is
|
---|
993 | * given, it is directly sent and no ARP request is sent out.
|
---|
994 | *
|
---|
995 | * If the IP address was already stable in the cache, and no packet is
|
---|
996 | * given, an ARP request is sent out.
|
---|
997 | *
|
---|
998 | * @param netif The lwIP network interface on which ipaddr
|
---|
999 | * must be queried for.
|
---|
1000 | * @param ipaddr The IP address to be resolved.
|
---|
1001 | * @param q If non-NULL, a pbuf that must be delivered to the IP address.
|
---|
1002 | * q is not freed by this function.
|
---|
1003 | *
|
---|
1004 | * @note q must only be ONE packet, not a packet queue!
|
---|
1005 | *
|
---|
1006 | * @return
|
---|
1007 | * - ERR_BUF Could not make room for Ethernet header.
|
---|
1008 | * - ERR_MEM Hardware address unknown, and no more ARP entries available
|
---|
1009 | * to query for address or queue the packet.
|
---|
1010 | * - ERR_MEM Could not queue packet due to memory shortage.
|
---|
1011 | * - ERR_RTE No route to destination (no gateway to external networks).
|
---|
1012 | * - ERR_ARG Non-unicast address given, those will not appear in ARP cache.
|
---|
1013 | *
|
---|
1014 | */
|
---|
1015 | err_t
|
---|
1016 | etharp_query(struct netif *netif, ip_addr_t *ipaddr, struct pbuf *q)
|
---|
1017 | {
|
---|
1018 | struct eth_addr * srcaddr = (struct eth_addr *)netif->hwaddr;
|
---|
1019 | err_t result = ERR_MEM;
|
---|
1020 | s8_t i; /* ARP entry index */
|
---|
1021 |
|
---|
1022 | /* non-unicast address? */
|
---|
1023 | if (ip_addr_isbroadcast(ipaddr, netif) ||
|
---|
1024 | ip_addr_ismulticast(ipaddr) ||
|
---|
1025 | ip_addr_isany(ipaddr)) {
|
---|
1026 | LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_query: will not add non-unicast IP address to ARP cache\n"));
|
---|
1027 | return ERR_ARG;
|
---|
1028 | }
|
---|
1029 |
|
---|
1030 | /* find entry in ARP cache, ask to create entry if queueing packet */
|
---|
1031 | i = etharp_find_entry(ipaddr, ETHARP_FLAG_TRY_HARD);
|
---|
1032 |
|
---|
1033 | /* could not find or create entry? */
|
---|
1034 | if (i < 0) {
|
---|
1035 | LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_query: could not create ARP entry\n"));
|
---|
1036 | if (q) {
|
---|
1037 | LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_query: packet dropped\n"));
|
---|
1038 | ETHARP_STATS_INC(etharp.memerr);
|
---|
1039 | }
|
---|
1040 | return (err_t)i;
|
---|
1041 | }
|
---|
1042 |
|
---|
1043 | /* mark a fresh entry as pending (we just sent a request) */
|
---|
1044 | if (arp_table[i].state == ETHARP_STATE_EMPTY) {
|
---|
1045 | arp_table[i].state = ETHARP_STATE_PENDING;
|
---|
1046 | }
|
---|
1047 |
|
---|
1048 | /* { i is either a STABLE or (new or existing) PENDING entry } */
|
---|
1049 | LWIP_ASSERT("arp_table[i].state == PENDING or STABLE",
|
---|
1050 | ((arp_table[i].state == ETHARP_STATE_PENDING) ||
|
---|
1051 | (arp_table[i].state >= ETHARP_STATE_STABLE)));
|
---|
1052 |
|
---|
1053 | /* do we have a pending entry? or an implicit query request? */
|
---|
1054 | if ((arp_table[i].state == ETHARP_STATE_PENDING) || (q == NULL)) {
|
---|
1055 | /* try to resolve it; send out ARP request */
|
---|
1056 | result = etharp_request(netif, ipaddr);
|
---|
1057 | if (result != ERR_OK) {
|
---|
1058 | /* ARP request couldn't be sent */
|
---|
1059 | /* We don't re-send arp request in etharp_tmr, but we still queue packets,
|
---|
1060 | since this failure could be temporary, and the next packet calling
|
---|
1061 | etharp_query again could lead to sending the queued packets. */
|
---|
1062 | }
|
---|
1063 | if (q == NULL) {
|
---|
1064 | return result;
|
---|
1065 | }
|
---|
1066 | }
|
---|
1067 |
|
---|
1068 | /* packet given? */
|
---|
1069 | LWIP_ASSERT("q != NULL", q != NULL);
|
---|
1070 | /* stable entry? */
|
---|
1071 | if (arp_table[i].state >= ETHARP_STATE_STABLE) {
|
---|
1072 | /* we have a valid IP->Ethernet address mapping */
|
---|
1073 | ETHARP_SET_HINT(netif, i);
|
---|
1074 | /* send the packet */
|
---|
1075 | result = etharp_send_ip(netif, q, srcaddr, &(arp_table[i].ethaddr));
|
---|
1076 | /* pending entry? (either just created or already pending */
|
---|
1077 | } else if (arp_table[i].state == ETHARP_STATE_PENDING) {
|
---|
1078 | /* entry is still pending, queue the given packet 'q' */
|
---|
1079 | struct pbuf *p;
|
---|
1080 | int copy_needed = 0;
|
---|
1081 | /* IF q includes a PBUF_REF, PBUF_POOL or PBUF_RAM, we have no choice but
|
---|
1082 | * to copy the whole queue into a new PBUF_RAM (see bug #11400)
|
---|
1083 | * PBUF_ROMs can be left as they are, since ROM must not get changed. */
|
---|
1084 | p = q;
|
---|
1085 | while (p) {
|
---|
1086 | LWIP_ASSERT("no packet queues allowed!", (p->len != p->tot_len) || (p->next == 0));
|
---|
1087 | if(p->type != PBUF_ROM) {
|
---|
1088 | copy_needed = 1;
|
---|
1089 | break;
|
---|
1090 | }
|
---|
1091 | p = p->next;
|
---|
1092 | }
|
---|
1093 | if(copy_needed) {
|
---|
1094 | /* copy the whole packet into new pbufs */
|
---|
1095 | p = pbuf_alloc(PBUF_RAW, p->tot_len, PBUF_RAM);
|
---|
1096 | if(p != NULL) {
|
---|
1097 | if (pbuf_copy(p, q) != ERR_OK) {
|
---|
1098 | pbuf_free(p);
|
---|
1099 | p = NULL;
|
---|
1100 | }
|
---|
1101 | }
|
---|
1102 | } else {
|
---|
1103 | /* referencing the old pbuf is enough */
|
---|
1104 | p = q;
|
---|
1105 | pbuf_ref(p);
|
---|
1106 | }
|
---|
1107 | /* packet could be taken over? */
|
---|
1108 | if (p != NULL) {
|
---|
1109 | /* queue packet ... */
|
---|
1110 | #if ARP_QUEUEING
|
---|
1111 | struct etharp_q_entry *new_entry;
|
---|
1112 | /* allocate a new arp queue entry */
|
---|
1113 | new_entry = (struct etharp_q_entry *)memp_malloc(MEMP_ARP_QUEUE);
|
---|
1114 | if (new_entry != NULL) {
|
---|
1115 | new_entry->next = 0;
|
---|
1116 | new_entry->p = p;
|
---|
1117 | if(arp_table[i].q != NULL) {
|
---|
1118 | /* queue was already existent, append the new entry to the end */
|
---|
1119 | struct etharp_q_entry *r;
|
---|
1120 | r = arp_table[i].q;
|
---|
1121 | while (r->next != NULL) {
|
---|
1122 | r = r->next;
|
---|
1123 | }
|
---|
1124 | r->next = new_entry;
|
---|
1125 | } else {
|
---|
1126 | /* queue did not exist, first item in queue */
|
---|
1127 | arp_table[i].q = new_entry;
|
---|
1128 | }
|
---|
1129 | LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_query: queued packet %p on ARP entry %"S16_F"\n", (void *)q, (s16_t)i));
|
---|
1130 | result = ERR_OK;
|
---|
1131 | } else {
|
---|
1132 | /* the pool MEMP_ARP_QUEUE is empty */
|
---|
1133 | pbuf_free(p);
|
---|
1134 | LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_query: could not queue a copy of PBUF_REF packet %p (out of memory)\n", (void *)q));
|
---|
1135 | result = ERR_MEM;
|
---|
1136 | }
|
---|
1137 | #else /* ARP_QUEUEING */
|
---|
1138 | /* always queue one packet per ARP request only, freeing a previously queued packet */
|
---|
1139 | if (arp_table[i].q != NULL) {
|
---|
1140 | LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_query: dropped previously queued packet %p for ARP entry %"S16_F"\n", (void *)q, (s16_t)i));
|
---|
1141 | pbuf_free(arp_table[i].q);
|
---|
1142 | }
|
---|
1143 | arp_table[i].q = p;
|
---|
1144 | result = ERR_OK;
|
---|
1145 | LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_query: queued packet %p on ARP entry %"S16_F"\n", (void *)q, (s16_t)i));
|
---|
1146 | #endif /* ARP_QUEUEING */
|
---|
1147 | } else {
|
---|
1148 | ETHARP_STATS_INC(etharp.memerr);
|
---|
1149 | LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_query: could not queue a copy of PBUF_REF packet %p (out of memory)\n", (void *)q));
|
---|
1150 | result = ERR_MEM;
|
---|
1151 | }
|
---|
1152 | }
|
---|
1153 | return result;
|
---|
1154 | }
|
---|
1155 |
|
---|
1156 | /**
|
---|
1157 | * Send a raw ARP packet (opcode and all addresses can be modified)
|
---|
1158 | *
|
---|
1159 | * @param netif the lwip network interface on which to send the ARP packet
|
---|
1160 | * @param ethsrc_addr the source MAC address for the ethernet header
|
---|
1161 | * @param ethdst_addr the destination MAC address for the ethernet header
|
---|
1162 | * @param hwsrc_addr the source MAC address for the ARP protocol header
|
---|
1163 | * @param ipsrc_addr the source IP address for the ARP protocol header
|
---|
1164 | * @param hwdst_addr the destination MAC address for the ARP protocol header
|
---|
1165 | * @param ipdst_addr the destination IP address for the ARP protocol header
|
---|
1166 | * @param opcode the type of the ARP packet
|
---|
1167 | * @return ERR_OK if the ARP packet has been sent
|
---|
1168 | * ERR_MEM if the ARP packet couldn't be allocated
|
---|
1169 | * any other err_t on failure
|
---|
1170 | */
|
---|
1171 | #if !LWIP_AUTOIP
|
---|
1172 | static
|
---|
1173 | #endif /* LWIP_AUTOIP */
|
---|
1174 | err_t
|
---|
1175 | etharp_raw(struct netif *netif, const struct eth_addr *ethsrc_addr,
|
---|
1176 | const struct eth_addr *ethdst_addr,
|
---|
1177 | const struct eth_addr *hwsrc_addr, const ip_addr_t *ipsrc_addr,
|
---|
1178 | const struct eth_addr *hwdst_addr, const ip_addr_t *ipdst_addr,
|
---|
1179 | const u16_t opcode)
|
---|
1180 | {
|
---|
1181 | struct pbuf *p;
|
---|
1182 | err_t result = ERR_OK;
|
---|
1183 | struct eth_hdr *ethhdr;
|
---|
1184 | struct etharp_hdr *hdr;
|
---|
1185 | #if LWIP_AUTOIP
|
---|
1186 | const u8_t * ethdst_hwaddr;
|
---|
1187 | #endif /* LWIP_AUTOIP */
|
---|
1188 |
|
---|
1189 | LWIP_ASSERT("netif != NULL", netif != NULL);
|
---|
1190 |
|
---|
1191 | /* allocate a pbuf for the outgoing ARP request packet */
|
---|
1192 | p = pbuf_alloc(PBUF_RAW, SIZEOF_ETHARP_PACKET, PBUF_RAM);
|
---|
1193 | /* could allocate a pbuf for an ARP request? */
|
---|
1194 | if (p == NULL) {
|
---|
1195 | LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS,
|
---|
1196 | ("etharp_raw: could not allocate pbuf for ARP request.\n"));
|
---|
1197 | ETHARP_STATS_INC(etharp.memerr);
|
---|
1198 | return ERR_MEM;
|
---|
1199 | }
|
---|
1200 | LWIP_ASSERT("check that first pbuf can hold struct etharp_hdr",
|
---|
1201 | (p->len >= SIZEOF_ETHARP_PACKET));
|
---|
1202 |
|
---|
1203 | ethhdr = (struct eth_hdr *)p->payload;
|
---|
1204 | hdr = (struct etharp_hdr *)((u8_t*)ethhdr + SIZEOF_ETH_HDR);
|
---|
1205 | LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_raw: sending raw ARP packet.\n"));
|
---|
1206 | hdr->opcode = htons(opcode);
|
---|
1207 |
|
---|
1208 | LWIP_ASSERT("netif->hwaddr_len must be the same as ETHARP_HWADDR_LEN for etharp!",
|
---|
1209 | (netif->hwaddr_len == ETHARP_HWADDR_LEN));
|
---|
1210 | #if LWIP_AUTOIP
|
---|
1211 | /* If we are using Link-Local, all ARP packets that contain a Link-Local
|
---|
1212 | * 'sender IP address' MUST be sent using link-layer broadcast instead of
|
---|
1213 | * link-layer unicast. (See RFC3927 Section 2.5, last paragraph) */
|
---|
1214 | ethdst_hwaddr = ip_addr_islinklocal(ipsrc_addr) ? (u8_t*)(ethbroadcast.addr) : ethdst_addr->addr;
|
---|
1215 | #endif /* LWIP_AUTOIP */
|
---|
1216 | /* Write the ARP MAC-Addresses */
|
---|
1217 | ETHADDR16_COPY(&hdr->shwaddr, hwsrc_addr);
|
---|
1218 | ETHADDR16_COPY(&hdr->dhwaddr, hwdst_addr);
|
---|
1219 | /* Write the Ethernet MAC-Addresses */
|
---|
1220 | #if LWIP_AUTOIP
|
---|
1221 | ETHADDR16_COPY(ðhdr->dest, ethdst_hwaddr);
|
---|
1222 | #else /* LWIP_AUTOIP */
|
---|
1223 | ETHADDR16_COPY(ðhdr->dest, ethdst_addr);
|
---|
1224 | #endif /* LWIP_AUTOIP */
|
---|
1225 | ETHADDR16_COPY(ðhdr->src, ethsrc_addr);
|
---|
1226 | /* Copy struct ip_addr2 to aligned ip_addr, to support compilers without
|
---|
1227 | * structure packing. */
|
---|
1228 | IPADDR2_COPY(&hdr->sipaddr, ipsrc_addr);
|
---|
1229 | IPADDR2_COPY(&hdr->dipaddr, ipdst_addr);
|
---|
1230 |
|
---|
1231 | hdr->hwtype = PP_HTONS(HWTYPE_ETHERNET);
|
---|
1232 | hdr->proto = PP_HTONS(ETHTYPE_IP);
|
---|
1233 | /* set hwlen and protolen */
|
---|
1234 | hdr->hwlen = ETHARP_HWADDR_LEN;
|
---|
1235 | hdr->protolen = sizeof(ip_addr_t);
|
---|
1236 |
|
---|
1237 | ethhdr->type = PP_HTONS(ETHTYPE_ARP);
|
---|
1238 | /* send ARP query */
|
---|
1239 | result = netif->linkoutput(netif, p);
|
---|
1240 | ETHARP_STATS_INC(etharp.xmit);
|
---|
1241 | /* free ARP query packet */
|
---|
1242 | pbuf_free(p);
|
---|
1243 | p = NULL;
|
---|
1244 | /* could not allocate pbuf for ARP request */
|
---|
1245 |
|
---|
1246 | return result;
|
---|
1247 | }
|
---|
1248 |
|
---|
1249 | /**
|
---|
1250 | * Send an ARP request packet asking for ipaddr.
|
---|
1251 | *
|
---|
1252 | * @param netif the lwip network interface on which to send the request
|
---|
1253 | * @param ipaddr the IP address for which to ask
|
---|
1254 | * @return ERR_OK if the request has been sent
|
---|
1255 | * ERR_MEM if the ARP packet couldn't be allocated
|
---|
1256 | * any other err_t on failure
|
---|
1257 | */
|
---|
1258 | err_t
|
---|
1259 | etharp_request(struct netif *netif, ip_addr_t *ipaddr)
|
---|
1260 | {
|
---|
1261 | LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_request: sending ARP request.\n"));
|
---|
1262 | return etharp_raw(netif, (struct eth_addr *)netif->hwaddr, ðbroadcast,
|
---|
1263 | (struct eth_addr *)netif->hwaddr, &netif->ip_addr, ðzero,
|
---|
1264 | ipaddr, ARP_REQUEST);
|
---|
1265 | }
|
---|
1266 | #endif /* LWIP_ARP */
|
---|
1267 |
|
---|
1268 | /**
|
---|
1269 | * Process received ethernet frames. Using this function instead of directly
|
---|
1270 | * calling ip_input and passing ARP frames through etharp in ethernetif_input,
|
---|
1271 | * the ARP cache is protected from concurrent access.
|
---|
1272 | *
|
---|
1273 | * @param p the recevied packet, p->payload pointing to the ethernet header
|
---|
1274 | * @param netif the network interface on which the packet was received
|
---|
1275 | */
|
---|
1276 | err_t
|
---|
1277 | ethernet_input(struct pbuf *p, struct netif *netif)
|
---|
1278 | {
|
---|
1279 | struct eth_hdr* ethhdr;
|
---|
1280 | u16_t type;
|
---|
1281 | #if LWIP_ARP || ETHARP_SUPPORT_VLAN
|
---|
1282 | s16_t ip_hdr_offset = SIZEOF_ETH_HDR;
|
---|
1283 | #endif /* LWIP_ARP || ETHARP_SUPPORT_VLAN */
|
---|
1284 |
|
---|
1285 | if (p->len <= SIZEOF_ETH_HDR) {
|
---|
1286 | /* a packet with only an ethernet header (or less) is not valid for us */
|
---|
1287 | ETHARP_STATS_INC(etharp.proterr);
|
---|
1288 | ETHARP_STATS_INC(etharp.drop);
|
---|
1289 | goto free_and_return;
|
---|
1290 | }
|
---|
1291 |
|
---|
1292 | /* points to packet payload, which starts with an Ethernet header */
|
---|
1293 | ethhdr = (struct eth_hdr *)p->payload;
|
---|
1294 | LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE,
|
---|
1295 | ("ethernet_input: dest:%"X8_F":%"X8_F":%"X8_F":%"X8_F":%"X8_F":%"X8_F", src:%"X8_F":%"X8_F":%"X8_F":%"X8_F":%"X8_F":%"X8_F", type:%"X16_F"\n",
|
---|
1296 | (unsigned)ethhdr->dest.addr[0], (unsigned)ethhdr->dest.addr[1], (unsigned)ethhdr->dest.addr[2],
|
---|
1297 | (unsigned)ethhdr->dest.addr[3], (unsigned)ethhdr->dest.addr[4], (unsigned)ethhdr->dest.addr[5],
|
---|
1298 | (unsigned)ethhdr->src.addr[0], (unsigned)ethhdr->src.addr[1], (unsigned)ethhdr->src.addr[2],
|
---|
1299 | (unsigned)ethhdr->src.addr[3], (unsigned)ethhdr->src.addr[4], (unsigned)ethhdr->src.addr[5],
|
---|
1300 | (unsigned)htons(ethhdr->type)));
|
---|
1301 |
|
---|
1302 | type = ethhdr->type;
|
---|
1303 | #if ETHARP_SUPPORT_VLAN
|
---|
1304 | if (type == PP_HTONS(ETHTYPE_VLAN)) {
|
---|
1305 | struct eth_vlan_hdr *vlan = (struct eth_vlan_hdr*)(((char*)ethhdr) + SIZEOF_ETH_HDR);
|
---|
1306 | if (p->len <= SIZEOF_ETH_HDR + SIZEOF_VLAN_HDR) {
|
---|
1307 | /* a packet with only an ethernet/vlan header (or less) is not valid for us */
|
---|
1308 | ETHARP_STATS_INC(etharp.proterr);
|
---|
1309 | ETHARP_STATS_INC(etharp.drop);
|
---|
1310 | goto free_and_return;
|
---|
1311 | }
|
---|
1312 | #if defined(ETHARP_VLAN_CHECK) || defined(ETHARP_VLAN_CHECK_FN) /* if not, allow all VLANs */
|
---|
1313 | #ifdef ETHARP_VLAN_CHECK_FN
|
---|
1314 | if (!ETHARP_VLAN_CHECK_FN(ethhdr, vlan)) {
|
---|
1315 | #elif defined(ETHARP_VLAN_CHECK)
|
---|
1316 | if (VLAN_ID(vlan) != ETHARP_VLAN_CHECK) {
|
---|
1317 | #endif
|
---|
1318 | /* silently ignore this packet: not for our VLAN */
|
---|
1319 | pbuf_free(p);
|
---|
1320 | return ERR_OK;
|
---|
1321 | }
|
---|
1322 | #endif /* defined(ETHARP_VLAN_CHECK) || defined(ETHARP_VLAN_CHECK_FN) */
|
---|
1323 | type = vlan->tpid;
|
---|
1324 | ip_hdr_offset = SIZEOF_ETH_HDR + SIZEOF_VLAN_HDR;
|
---|
1325 | }
|
---|
1326 | #endif /* ETHARP_SUPPORT_VLAN */
|
---|
1327 |
|
---|
1328 | #if LWIP_ARP_FILTER_NETIF
|
---|
1329 | netif = LWIP_ARP_FILTER_NETIF_FN(p, netif, htons(type));
|
---|
1330 | #endif /* LWIP_ARP_FILTER_NETIF*/
|
---|
1331 |
|
---|
1332 | if (ethhdr->dest.addr[0] & 1) {
|
---|
1333 | /* this might be a multicast or broadcast packet */
|
---|
1334 | if (ethhdr->dest.addr[0] == LL_MULTICAST_ADDR_0) {
|
---|
1335 | if ((ethhdr->dest.addr[1] == LL_MULTICAST_ADDR_1) &&
|
---|
1336 | (ethhdr->dest.addr[2] == LL_MULTICAST_ADDR_2)) {
|
---|
1337 | /* mark the pbuf as link-layer multicast */
|
---|
1338 | p->flags |= PBUF_FLAG_LLMCAST;
|
---|
1339 | }
|
---|
1340 | } else if (eth_addr_cmp(ðhdr->dest, ðbroadcast)) {
|
---|
1341 | /* mark the pbuf as link-layer broadcast */
|
---|
1342 | p->flags |= PBUF_FLAG_LLBCAST;
|
---|
1343 | }
|
---|
1344 | }
|
---|
1345 |
|
---|
1346 | switch (type) {
|
---|
1347 | #if LWIP_ARP
|
---|
1348 | /* IP packet? */
|
---|
1349 | case PP_HTONS(ETHTYPE_IP):
|
---|
1350 | if (!(netif->flags & NETIF_FLAG_ETHARP)) {
|
---|
1351 | goto free_and_return;
|
---|
1352 | }
|
---|
1353 | #if ETHARP_TRUST_IP_MAC
|
---|
1354 | /* update ARP table */
|
---|
1355 | etharp_ip_input(netif, p);
|
---|
1356 | #endif /* ETHARP_TRUST_IP_MAC */
|
---|
1357 | /* skip Ethernet header */
|
---|
1358 | if(pbuf_header(p, -ip_hdr_offset)) {
|
---|
1359 | LWIP_ASSERT("Can't move over header in packet", 0);
|
---|
1360 | goto free_and_return;
|
---|
1361 | } else {
|
---|
1362 | /* pass to IP layer */
|
---|
1363 | ip_input(p, netif);
|
---|
1364 | }
|
---|
1365 | break;
|
---|
1366 |
|
---|
1367 | case PP_HTONS(ETHTYPE_ARP):
|
---|
1368 | if (!(netif->flags & NETIF_FLAG_ETHARP)) {
|
---|
1369 | goto free_and_return;
|
---|
1370 | }
|
---|
1371 | /* pass p to ARP module */
|
---|
1372 | etharp_arp_input(netif, (struct eth_addr*)(netif->hwaddr), p);
|
---|
1373 | break;
|
---|
1374 | #endif /* LWIP_ARP */
|
---|
1375 | #if PPPOE_SUPPORT
|
---|
1376 | case PP_HTONS(ETHTYPE_PPPOEDISC): /* PPP Over Ethernet Discovery Stage */
|
---|
1377 | pppoe_disc_input(netif, p);
|
---|
1378 | break;
|
---|
1379 |
|
---|
1380 | case PP_HTONS(ETHTYPE_PPPOE): /* PPP Over Ethernet Session Stage */
|
---|
1381 | pppoe_data_input(netif, p);
|
---|
1382 | break;
|
---|
1383 | #endif /* PPPOE_SUPPORT */
|
---|
1384 |
|
---|
1385 | default:
|
---|
1386 | ETHARP_STATS_INC(etharp.proterr);
|
---|
1387 | ETHARP_STATS_INC(etharp.drop);
|
---|
1388 | goto free_and_return;
|
---|
1389 | }
|
---|
1390 |
|
---|
1391 | /* This means the pbuf is freed or consumed,
|
---|
1392 | so the caller doesn't have to free it again */
|
---|
1393 | return ERR_OK;
|
---|
1394 |
|
---|
1395 | free_and_return:
|
---|
1396 | pbuf_free(p);
|
---|
1397 | return ERR_OK;
|
---|
1398 | }
|
---|
1399 | #endif /* LWIP_ARP || LWIP_ETHERNET */
|
---|