1 | /**
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2 | * @file
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3 | * Ethernet Interface Skeleton
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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 | * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
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9 | * All rights reserved.
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10 | *
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11 | * Redistribution and use in source and binary forms, with or without modification,
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12 | * are permitted provided that the following conditions are met:
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13 | *
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14 | * 1. Redistributions of source code must retain the above copyright notice,
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15 | * this list of conditions and the following disclaimer.
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16 | * 2. Redistributions in binary form must reproduce the above copyright notice,
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17 | * this list of conditions and the following disclaimer in the documentation
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18 | * and/or other materials provided with the distribution.
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19 | * 3. The name of the author may not be used to endorse or promote products
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20 | * derived from this software without specific prior written permission.
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21 | *
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22 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
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23 | * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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24 | * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
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25 | * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
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26 | * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
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27 | * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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28 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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29 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
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30 | * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
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31 | * OF SUCH DAMAGE.
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32 | *
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33 | * This file is part of the lwIP TCP/IP stack.
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34 | *
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35 | * Author: Adam Dunkels <adam@sics.se>
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36 | *
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37 | */
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38 |
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39 | /*
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40 | * This file is a skeleton for developing Ethernet network interface
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41 | * drivers for lwIP. Add code to the low_level functions and do a
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42 | * search-and-replace for the word "ethernetif" to replace it with
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43 | * something that better describes your network interface.
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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 0 /* don't build, this is only a skeleton, see previous comment */
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49 |
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50 | #include "lwip/def.h"
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51 | #include "lwip/mem.h"
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52 | #include "lwip/pbuf.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 "netif/etharp.h"
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56 | #include "netif/ppp_oe.h"
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57 |
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58 | /* Define those to better describe your network interface. */
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59 | #define IFNAME0 'e'
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60 | #define IFNAME1 'n'
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61 |
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62 | /**
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63 | * Helper struct to hold private data used to operate your ethernet interface.
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64 | * Keeping the ethernet address of the MAC in this struct is not necessary
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65 | * as it is already kept in the struct netif.
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66 | * But this is only an example, anyway...
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67 | */
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68 | struct ethernetif {
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69 | struct eth_addr *ethaddr;
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70 | /* Add whatever per-interface state that is needed here. */
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71 | };
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72 |
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73 | /* Forward declarations. */
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74 | static void ethernetif_input(struct netif *netif);
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75 |
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76 | /**
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77 | * In this function, the hardware should be initialized.
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78 | * Called from ethernetif_init().
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79 | *
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80 | * @param netif the already initialized lwip network interface structure
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81 | * for this ethernetif
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82 | */
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83 | static void
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84 | low_level_init(struct netif *netif)
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85 | {
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86 | struct ethernetif *ethernetif = netif->state;
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87 |
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88 | /* set MAC hardware address length */
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89 | netif->hwaddr_len = ETHARP_HWADDR_LEN;
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90 |
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91 | /* set MAC hardware address */
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92 | netif->hwaddr[0] = ;
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93 | ...
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94 | netif->hwaddr[5] = ;
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95 |
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96 | /* maximum transfer unit */
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97 | netif->mtu = 1500;
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98 |
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99 | /* device capabilities */
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100 | /* don't set NETIF_FLAG_ETHARP if this device is not an ethernet one */
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101 | netif->flags = NETIF_FLAG_BROADCAST | NETIF_FLAG_ETHARP | NETIF_FLAG_LINK_UP;
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102 |
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103 | /* Do whatever else is needed to initialize interface. */
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104 | }
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105 |
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106 | /**
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107 | * This function should do the actual transmission of the packet. The packet is
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108 | * contained in the pbuf that is passed to the function. This pbuf
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109 | * might be chained.
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110 | *
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111 | * @param netif the lwip network interface structure for this ethernetif
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112 | * @param p the MAC packet to send (e.g. IP packet including MAC addresses and type)
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113 | * @return ERR_OK if the packet could be sent
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114 | * an err_t value if the packet couldn't be sent
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115 | *
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116 | * @note Returning ERR_MEM here if a DMA queue of your MAC is full can lead to
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117 | * strange results. You might consider waiting for space in the DMA queue
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118 | * to become availale since the stack doesn't retry to send a packet
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119 | * dropped because of memory failure (except for the TCP timers).
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120 | */
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121 |
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122 | static err_t
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123 | low_level_output(struct netif *netif, struct pbuf *p)
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124 | {
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125 | struct ethernetif *ethernetif = netif->state;
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126 | struct pbuf *q;
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127 |
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128 | initiate transfer();
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129 |
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130 | #if ETH_PAD_SIZE
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131 | pbuf_header(p, -ETH_PAD_SIZE); /* drop the padding word */
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132 | #endif
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133 |
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134 | for(q = p; q != NULL; q = q->next) {
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135 | /* Send the data from the pbuf to the interface, one pbuf at a
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136 | time. The size of the data in each pbuf is kept in the ->len
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137 | variable. */
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138 | send data from(q->payload, q->len);
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139 | }
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140 |
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141 | signal that packet should be sent();
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142 |
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143 | #if ETH_PAD_SIZE
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144 | pbuf_header(p, ETH_PAD_SIZE); /* reclaim the padding word */
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145 | #endif
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146 |
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147 | LINK_STATS_INC(link.xmit);
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148 |
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149 | return ERR_OK;
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150 | }
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151 |
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152 | /**
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153 | * Should allocate a pbuf and transfer the bytes of the incoming
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154 | * packet from the interface into the pbuf.
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155 | *
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156 | * @param netif the lwip network interface structure for this ethernetif
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157 | * @return a pbuf filled with the received packet (including MAC header)
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158 | * NULL on memory error
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159 | */
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160 | static struct pbuf *
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161 | low_level_input(struct netif *netif)
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162 | {
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163 | struct ethernetif *ethernetif = netif->state;
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164 | struct pbuf *p, *q;
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165 | u16_t len;
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166 |
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167 | /* Obtain the size of the packet and put it into the "len"
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168 | variable. */
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169 | len = ;
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170 |
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171 | #if ETH_PAD_SIZE
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172 | len += ETH_PAD_SIZE; /* allow room for Ethernet padding */
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173 | #endif
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174 |
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175 | /* We allocate a pbuf chain of pbufs from the pool. */
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176 | p = pbuf_alloc(PBUF_RAW, len, PBUF_POOL);
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177 |
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178 | if (p != NULL) {
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179 |
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180 | #if ETH_PAD_SIZE
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181 | pbuf_header(p, -ETH_PAD_SIZE); /* drop the padding word */
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182 | #endif
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183 |
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184 | /* We iterate over the pbuf chain until we have read the entire
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185 | * packet into the pbuf. */
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186 | for(q = p; q != NULL; q = q->next) {
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187 | /* Read enough bytes to fill this pbuf in the chain. The
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188 | * available data in the pbuf is given by the q->len
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189 | * variable.
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190 | * This does not necessarily have to be a memcpy, you can also preallocate
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191 | * pbufs for a DMA-enabled MAC and after receiving truncate it to the
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192 | * actually received size. In this case, ensure the tot_len member of the
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193 | * pbuf is the sum of the chained pbuf len members.
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194 | */
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195 | read data into(q->payload, q->len);
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196 | }
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197 | acknowledge that packet has been read();
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198 |
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199 | #if ETH_PAD_SIZE
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200 | pbuf_header(p, ETH_PAD_SIZE); /* reclaim the padding word */
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201 | #endif
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202 |
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203 | LINK_STATS_INC(link.recv);
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204 | } else {
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205 | drop packet();
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206 | LINK_STATS_INC(link.memerr);
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207 | LINK_STATS_INC(link.drop);
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208 | }
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209 |
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210 | return p;
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211 | }
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212 |
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213 | /**
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214 | * This function should be called when a packet is ready to be read
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215 | * from the interface. It uses the function low_level_input() that
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216 | * should handle the actual reception of bytes from the network
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217 | * interface. Then the type of the received packet is determined and
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218 | * the appropriate input function is called.
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219 | *
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220 | * @param netif the lwip network interface structure for this ethernetif
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221 | */
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222 | static void
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223 | ethernetif_input(struct netif *netif)
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224 | {
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225 | struct ethernetif *ethernetif;
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226 | struct eth_hdr *ethhdr;
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227 | struct pbuf *p;
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228 |
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229 | ethernetif = netif->state;
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230 |
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231 | /* move received packet into a new pbuf */
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232 | p = low_level_input(netif);
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233 | /* no packet could be read, silently ignore this */
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234 | if (p == NULL) return;
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235 | /* points to packet payload, which starts with an Ethernet header */
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236 | ethhdr = p->payload;
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237 |
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238 | switch (htons(ethhdr->type)) {
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239 | /* IP or ARP packet? */
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240 | case ETHTYPE_IP:
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241 | case ETHTYPE_ARP:
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242 | #if PPPOE_SUPPORT
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243 | /* PPPoE packet? */
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244 | case ETHTYPE_PPPOEDISC:
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245 | case ETHTYPE_PPPOE:
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246 | #endif /* PPPOE_SUPPORT */
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247 | /* full packet send to tcpip_thread to process */
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248 | if (netif->input(p, netif)!=ERR_OK)
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249 | { LWIP_DEBUGF(NETIF_DEBUG, ("ethernetif_input: IP input error\n"));
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250 | pbuf_free(p);
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251 | p = NULL;
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252 | }
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253 | break;
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254 |
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255 | default:
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256 | pbuf_free(p);
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257 | p = NULL;
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258 | break;
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259 | }
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260 | }
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261 |
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262 | /**
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263 | * Should be called at the beginning of the program to set up the
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264 | * network interface. It calls the function low_level_init() to do the
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265 | * actual setup of the hardware.
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266 | *
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267 | * This function should be passed as a parameter to netif_add().
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268 | *
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269 | * @param netif the lwip network interface structure for this ethernetif
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270 | * @return ERR_OK if the loopif is initialized
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271 | * ERR_MEM if private data couldn't be allocated
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272 | * any other err_t on error
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273 | */
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274 | err_t
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275 | ethernetif_init(struct netif *netif)
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276 | {
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277 | struct ethernetif *ethernetif;
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278 |
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279 | LWIP_ASSERT("netif != NULL", (netif != NULL));
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280 |
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281 | ethernetif = mem_malloc(sizeof(struct ethernetif));
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282 | if (ethernetif == NULL) {
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283 | LWIP_DEBUGF(NETIF_DEBUG, ("ethernetif_init: out of memory\n"));
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284 | return ERR_MEM;
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285 | }
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286 |
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287 | #if LWIP_NETIF_HOSTNAME
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288 | /* Initialize interface hostname */
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289 | netif->hostname = "lwip";
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290 | #endif /* LWIP_NETIF_HOSTNAME */
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291 |
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292 | /*
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293 | * Initialize the snmp variables and counters inside the struct netif.
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294 | * The last argument should be replaced with your link speed, in units
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295 | * of bits per second.
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296 | */
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297 | NETIF_INIT_SNMP(netif, snmp_ifType_ethernet_csmacd, LINK_SPEED_OF_YOUR_NETIF_IN_BPS);
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298 |
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299 | netif->state = ethernetif;
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300 | netif->name[0] = IFNAME0;
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301 | netif->name[1] = IFNAME1;
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302 | /* We directly use etharp_output() here to save a function call.
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303 | * You can instead declare your own function an call etharp_output()
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304 | * from it if you have to do some checks before sending (e.g. if link
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305 | * is available...) */
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306 | netif->output = etharp_output;
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307 | netif->linkoutput = low_level_output;
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308 |
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309 | ethernetif->ethaddr = (struct eth_addr *)&(netif->hwaddr[0]);
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310 |
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311 | /* initialize the hardware */
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312 | low_level_init(netif);
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313 |
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314 | return ERR_OK;
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315 | }
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316 |
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317 | #endif /* 0 */
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