1 | #define DEBUG_PRINTF(...) /*printf(__VA_ARGS__)*/
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2 |
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3 | /**
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4 | * \defgroup uip The uIP TCP/IP stack
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5 | * @{
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6 | *
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7 | * uIP is an implementation of the TCP/IP protocol stack intended for
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8 | * small 8-bit and 16-bit microcontrollers.
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9 | *
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10 | * uIP provides the necessary protocols for Internet communication,
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11 | * with a very small code footprint and RAM requirements - the uIP
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12 | * code size is on the order of a few kilobytes and RAM usage is on
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13 | * the order of a few hundred bytes.
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14 | */
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15 |
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16 | /**
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17 | * \file
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18 | * The uIP TCP/IP stack code.
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19 | * \author Adam Dunkels <adam@dunkels.com>
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20 | */
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21 |
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22 | /*
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23 | * Copyright (c) 2001-2003, Adam Dunkels.
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24 | * All rights reserved.
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25 | *
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26 | * Redistribution and use in source and binary forms, with or without
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27 | * modification, are permitted provided that the following conditions
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28 | * are met:
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29 | * 1. Redistributions of source code must retain the above copyright
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30 | * notice, this list of conditions and the following disclaimer.
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31 | * 2. Redistributions in binary form must reproduce the above copyright
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32 | * notice, this list of conditions and the following disclaimer in the
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33 | * documentation and/or other materials provided with the distribution.
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34 | * 3. The name of the author may not be used to endorse or promote
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35 | * products derived from this software without specific prior
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36 | * written permission.
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37 | *
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38 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
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39 | * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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40 | * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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41 | * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
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42 | * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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43 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
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44 | * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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45 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
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46 | * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
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47 | * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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48 | * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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49 | *
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50 | * This file is part of the uIP TCP/IP stack.
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51 | *
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52 | * $Id: uip.c 158 2016-02-20 13:43:32Z coas-nagasima $
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53 | *
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54 | */
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55 |
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56 | /*
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57 | * uIP is a small implementation of the IP, UDP and TCP protocols (as
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58 | * well as some basic ICMP stuff). The implementation couples the IP,
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59 | * UDP, TCP and the application layers very tightly. To keep the size
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60 | * of the compiled code down, this code frequently uses the goto
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61 | * statement. While it would be possible to break the uip_process()
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62 | * function into many smaller functions, this would increase the code
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63 | * size because of the overhead of parameter passing and the fact that
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64 | * the optimier would not be as efficient.
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65 | *
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66 | * The principle is that we have a small buffer, called the uip_buf,
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67 | * in which the device driver puts an incoming packet. The TCP/IP
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68 | * stack parses the headers in the packet, and calls the
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69 | * application. If the remote host has sent data to the application,
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70 | * this data is present in the uip_buf and the application read the
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71 | * data from there. It is up to the application to put this data into
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72 | * a byte stream if needed. The application will not be fed with data
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73 | * that is out of sequence.
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74 | *
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75 | * If the application whishes to send data to the peer, it should put
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76 | * its data into the uip_buf. The uip_appdata pointer points to the
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77 | * first available byte. The TCP/IP stack will calculate the
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78 | * checksums, and fill in the necessary header fields and finally send
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79 | * the packet back to the peer.
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80 | */
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81 |
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82 | #include "net/ip/uip.h"
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83 | #include "net/ip/uipopt.h"
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84 | #include "net/ip/uip_arch.h"
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85 |
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86 | #if UIP_CONF_IPV6
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87 | #include "net/ipv4/uip-neighbor.h"
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88 | #endif /* UIP_CONF_IPV6 */
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89 |
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90 | #include <string.h>
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91 |
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92 | /*---------------------------------------------------------------------------*/
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93 | /* Variable definitions. */
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94 |
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95 |
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96 | /* The IP address of this host. If it is defined to be fixed (by
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97 | setting UIP_FIXEDADDR to 1 in uipopt.h), the address is set
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98 | here. Otherwise, the address */
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99 | #if UIP_FIXEDADDR > 0
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100 | const uip_ipaddr_t uip_hostaddr =
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101 | {HTONS((UIP_IPADDR0 << 8) | UIP_IPADDR1),
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102 | HTONS((UIP_IPADDR2 << 8) | UIP_IPADDR3)};
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103 | const uip_ipaddr_t uip_draddr =
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104 | {HTONS((UIP_DRIPADDR0 << 8) | UIP_DRIPADDR1),
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105 | HTONS((UIP_DRIPADDR2 << 8) | UIP_DRIPADDR3)};
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106 | const uip_ipaddr_t uip_netmask =
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107 | {HTONS((UIP_NETMASK0 << 8) | UIP_NETMASK1),
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108 | HTONS((UIP_NETMASK2 << 8) | UIP_NETMASK3)};
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109 | #else
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110 | uip_ipaddr_t uip_hostaddr, uip_draddr, uip_netmask;
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111 | #endif /* UIP_FIXEDADDR */
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112 |
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113 | static const uip_ipaddr_t all_ones_addr =
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114 | #if UIP_CONF_IPV6
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115 | {0xffff,0xffff,0xffff,0xffff,0xffff,0xffff,0xffff,0xffff};
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116 | #else /* UIP_CONF_IPV6 */
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117 | {0xffff,0xffff};
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118 | #endif /* UIP_CONF_IPV6 */
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119 | static const uip_ipaddr_t all_zeroes_addr =
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120 | #if UIP_CONF_IPV6
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121 | {0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000};
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122 | #else /* UIP_CONF_IPV6 */
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123 | {0x0000,0x0000};
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124 | #endif /* UIP_CONF_IPV6 */
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125 |
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126 |
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127 | #if UIP_FIXEDETHADDR
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128 | const struct uip_eth_addr uip_ethaddr = {{UIP_ETHADDR0,
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129 | UIP_ETHADDR1,
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130 | UIP_ETHADDR2,
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131 | UIP_ETHADDR3,
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132 | UIP_ETHADDR4,
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133 | UIP_ETHADDR5}};
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134 | #else
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135 | struct uip_eth_addr uip_ethaddr = {{0,0,0,0,0,0}};
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136 | #endif
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137 |
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138 | #ifndef UIP_CONF_EXTERNAL_BUFFER
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139 | uint8_t uip_buf[UIP_BUFSIZE + 2]; /* The packet buffer that contains
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140 | incoming packets. */
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141 | #endif /* UIP_CONF_EXTERNAL_BUFFER */
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142 |
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143 | void *uip_appdata; /* The uip_appdata pointer points to
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144 | application data. */
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145 | void *uip_sappdata; /* The uip_appdata pointer points to
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146 | the application data which is to
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147 | be sent. */
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148 | #if UIP_URGDATA > 0
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149 | void *uip_urgdata; /* The uip_urgdata pointer points to
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150 | urgent data (out-of-band data), if
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151 | present. */
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152 | uint16_t uip_urglen, uip_surglen;
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153 | #endif /* UIP_URGDATA > 0 */
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154 |
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155 | uint16_t uip_len, uip_slen;
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156 | /* The uip_len is either 8 or 16 bits,
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157 | depending on the maximum packet
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158 | size. */
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159 |
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160 | uint8_t uip_flags; /* The uip_flags variable is used for
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161 | communication between the TCP/IP stack
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162 | and the application program. */
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163 | struct uip_conn *uip_conn; /* uip_conn always points to the current
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164 | connection. */
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165 |
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166 | struct uip_conn uip_conns[UIP_CONNS];
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167 | /* The uip_conns array holds all TCP
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168 | connections. */
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169 | uint16_t uip_listenports[UIP_LISTENPORTS];
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170 | /* The uip_listenports list all currently
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171 | listning ports. */
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172 | #if UIP_UDP
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173 | struct uip_udp_conn *uip_udp_conn;
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174 | struct uip_udp_conn uip_udp_conns[UIP_UDP_CONNS];
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175 | #endif /* UIP_UDP */
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176 |
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177 | static uint16_t ipid; /* Ths ipid variable is an increasing
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178 | number that is used for the IP ID
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179 | field. */
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180 |
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181 | void uip_setipid(uint16_t id) { ipid = id; }
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182 |
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183 | static uint8_t iss[4]; /* The iss variable is used for the TCP
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184 | initial sequence number. */
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185 |
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186 | #if UIP_ACTIVE_OPEN
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187 | static uint16_t lastport; /* Keeps track of the last port used for
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188 | a new connection. */
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189 | #endif /* UIP_ACTIVE_OPEN */
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190 |
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191 | /* Temporary variables. */
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192 | uint8_t uip_acc32[4];
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193 | static uint8_t c, opt;
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194 | static uint16_t tmp16;
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195 |
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196 | /* Structures and definitions. */
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197 | #define TCP_FIN 0x01
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198 | #define TCP_SYN 0x02
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199 | #define TCP_RST 0x04
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200 | #define TCP_PSH 0x08
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201 | #define TCP_ACK 0x10
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202 | #define TCP_URG 0x20
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203 | #define TCP_CTL 0x3f
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204 |
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205 | #define TCP_OPT_END 0 /* End of TCP options list */
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206 | #define TCP_OPT_NOOP 1 /* "No-operation" TCP option */
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207 | #define TCP_OPT_MSS 2 /* Maximum segment size TCP option */
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208 |
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209 | #define TCP_OPT_MSS_LEN 4 /* Length of TCP MSS option. */
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210 |
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211 | #define ICMP_ECHO_REPLY 0
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212 | #define ICMP_ECHO 8
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213 |
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214 | #define ICMP6_ECHO_REPLY 129
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215 | #define ICMP6_ECHO 128
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216 | #define ICMP6_NEIGHBOR_SOLICITATION 135
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217 | #define ICMP6_NEIGHBOR_ADVERTISEMENT 136
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218 |
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219 | #define ICMP6_FLAG_S (1 << 6)
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220 |
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221 | #define ICMP6_OPTION_SOURCE_LINK_ADDRESS 1
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222 | #define ICMP6_OPTION_TARGET_LINK_ADDRESS 2
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223 |
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224 |
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225 | /* Macros. */
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226 | #define BUF ((struct uip_tcpip_hdr *)&uip_buf[UIP_LLH_LEN])
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227 | #define FBUF ((struct uip_tcpip_hdr *)&uip_reassbuf[0])
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228 | #define ICMPBUF ((struct uip_icmpip_hdr *)&uip_buf[UIP_LLH_LEN])
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229 | #define UDPBUF ((struct uip_udpip_hdr *)&uip_buf[UIP_LLH_LEN])
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230 |
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231 |
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232 | #if UIP_STATISTICS == 1
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233 | struct uip_stats uip_stat;
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234 | #define UIP_STAT(s) s
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235 | #else
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236 | #define UIP_STAT(s)
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237 | #endif /* UIP_STATISTICS == 1 */
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238 |
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239 | #if UIP_LOGGING == 1
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240 | #include <stdio.h>
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241 | void uip_log(char *msg);
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242 | #define UIP_LOG(m) uip_log(m)
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243 | #else
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244 | #define UIP_LOG(m)
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245 | #endif /* UIP_LOGGING == 1 */
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246 |
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247 | #if ! UIP_ARCH_ADD32
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248 | void
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249 | uip_add32(uint8_t *op32, uint16_t op16)
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250 | {
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251 | uip_acc32[3] = op32[3] + (op16 & 0xff);
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252 | uip_acc32[2] = op32[2] + (op16 >> 8);
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253 | uip_acc32[1] = op32[1];
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254 | uip_acc32[0] = op32[0];
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255 |
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256 | if(uip_acc32[2] < (op16 >> 8)) {
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257 | ++uip_acc32[1];
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258 | if(uip_acc32[1] == 0) {
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259 | ++uip_acc32[0];
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260 | }
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261 | }
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262 |
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263 |
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264 | if(uip_acc32[3] < (op16 & 0xff)) {
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265 | ++uip_acc32[2];
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266 | if(uip_acc32[2] == 0) {
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267 | ++uip_acc32[1];
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268 | if(uip_acc32[1] == 0) {
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269 | ++uip_acc32[0];
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270 | }
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271 | }
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272 | }
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273 | }
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274 |
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275 | #endif /* UIP_ARCH_ADD32 */
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276 |
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277 | #if ! UIP_ARCH_CHKSUM
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278 | /*---------------------------------------------------------------------------*/
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279 | static uint16_t
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280 | chksum(uint16_t sum, const uint8_t *data, uint16_t len)
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281 | {
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282 | uint16_t t;
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283 | const uint8_t *dataptr;
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284 | const uint8_t *last_byte;
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285 |
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286 | dataptr = data;
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287 | last_byte = data + len - 1;
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288 |
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289 | while(dataptr < last_byte) { /* At least two more bytes */
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290 | t = (dataptr[0] << 8) + dataptr[1];
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291 | sum += t;
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292 | if(sum < t) {
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293 | sum++; /* carry */
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294 | }
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295 | dataptr += 2;
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296 | }
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297 |
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298 | if(dataptr == last_byte) {
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299 | t = (dataptr[0] << 8) + 0;
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300 | sum += t;
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301 | if(sum < t) {
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302 | sum++; /* carry */
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303 | }
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304 | }
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305 |
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306 | /* Return sum in host byte order. */
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307 | return sum;
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308 | }
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309 | /*---------------------------------------------------------------------------*/
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310 | uint16_t
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311 | uip_chksum(uint16_t *data, uint16_t len)
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312 | {
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313 | return htons(chksum(0, (uint8_t *)data, len));
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314 | }
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315 | /*---------------------------------------------------------------------------*/
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316 | #ifndef UIP_ARCH_IPCHKSUM
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317 | uint16_t
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318 | uip_ipchksum(void)
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319 | {
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320 | uint16_t sum;
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321 |
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322 | sum = chksum(0, &uip_buf[UIP_LLH_LEN], UIP_IPH_LEN);
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323 | DEBUG_PRINTF("uip_ipchksum: sum 0x%04x\n", sum);
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324 | return (sum == 0) ? 0xffff : htons(sum);
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325 | }
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326 | #endif
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327 | /*---------------------------------------------------------------------------*/
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328 | static uint16_t
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329 | upper_layer_chksum(uint8_t proto)
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330 | {
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331 | uint16_t upper_layer_len;
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332 | uint16_t sum;
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333 |
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334 | #if UIP_CONF_IPV6
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335 | upper_layer_len = (((uint16_t)(BUF->len[0]) << 8) + BUF->len[1]);
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336 | #else /* UIP_CONF_IPV6 */
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337 | upper_layer_len = (((uint16_t)(BUF->len[0]) << 8) + BUF->len[1]) - UIP_IPH_LEN;
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338 | #endif /* UIP_CONF_IPV6 */
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339 |
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340 | /* First sum pseudoheader. */
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341 |
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342 | /* IP protocol and length fields. This addition cannot carry. */
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343 | sum = upper_layer_len + proto;
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344 | /* Sum IP source and destination addresses. */
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345 | sum = chksum(sum, (uint8_t *)&BUF->srcipaddr[0], 2 * sizeof(uip_ipaddr_t));
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346 |
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347 | /* Sum TCP header and data. */
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348 | sum = chksum(sum, &uip_buf[UIP_IPH_LEN + UIP_LLH_LEN],
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349 | upper_layer_len);
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350 |
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351 | return (sum == 0) ? 0xffff : htons(sum);
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352 | }
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353 | /*---------------------------------------------------------------------------*/
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354 | #if UIP_CONF_IPV6
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355 | uint16_t
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356 | uip_icmp6chksum(void)
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357 | {
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358 | return upper_layer_chksum(UIP_PROTO_ICMP6);
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359 |
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360 | }
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361 | #endif /* UIP_CONF_IPV6 */
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362 | /*---------------------------------------------------------------------------*/
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363 | uint16_t
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364 | uip_tcpchksum(void)
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365 | {
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366 | return upper_layer_chksum(UIP_PROTO_TCP);
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367 | }
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368 | /*---------------------------------------------------------------------------*/
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369 | #if UIP_UDP_CHECKSUMS
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370 | uint16_t
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371 | uip_udpchksum(void)
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372 | {
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373 | return upper_layer_chksum(UIP_PROTO_UDP);
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374 | }
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375 | #endif /* UIP_UDP_CHECKSUMS */
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376 | #endif /* UIP_ARCH_CHKSUM */
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377 | uint8_t
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378 | uip_ismulticast(uip_ipaddr_t ipaddr)
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379 | {
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380 | #if UIP_CONF_IPV6
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381 | return 0;
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382 | #else
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383 | static const uint16_t multicast_ipaddr[2] = { 0x00e0, 0x0000 };
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384 | static const uint16_t multicast_mask[2] = { 0x00f0, 0x0000 };
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385 | return uip_ipaddr_maskcmp(ipaddr, multicast_ipaddr, multicast_mask);
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386 | #endif
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387 | }
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388 | /*---------------------------------------------------------------------------*/
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389 | void
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390 | uip_init(void)
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391 | {
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392 | for(c = 0; c < UIP_LISTENPORTS; ++c) {
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393 | uip_listenports[c] = 0;
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394 | }
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395 | for(c = 0; c < UIP_CONNS; ++c) {
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396 | uip_conns[c].tcpstateflags = UIP_CLOSED;
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397 | }
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398 | #if UIP_ACTIVE_OPEN
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399 | lastport = 1024;
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400 | #endif /* UIP_ACTIVE_OPEN */
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401 |
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402 | #if UIP_UDP
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403 | for(c = 0; c < UIP_UDP_CONNS; ++c) {
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404 | uip_udp_conns[c].lport = 0;
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405 | }
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406 | #endif /* UIP_UDP */
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407 |
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408 |
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409 | /* IPv4 initialization. */
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410 | #if UIP_FIXEDADDR == 0
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411 | /* uip_hostaddr[0] = uip_hostaddr[1] = 0;*/
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412 | #endif /* UIP_FIXEDADDR */
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413 |
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414 | }
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415 | /*---------------------------------------------------------------------------*/
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416 | #if UIP_ACTIVE_OPEN
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417 | struct uip_conn *
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418 | uip_connect(uip_ipaddr_t *ripaddr, uint16_t rport)
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419 | {
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420 | register struct uip_conn *conn, *cconn;
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421 |
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422 | /* Find an unused local port. */
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423 | again:
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424 | ++lastport;
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425 |
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426 | if(lastport >= 32000) {
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427 | lastport = 4096;
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428 | }
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429 |
|
---|
430 | /* Check if this port is already in use, and if so try to find
|
---|
431 | another one. */
|
---|
432 | for(c = 0; c < UIP_CONNS; ++c) {
|
---|
433 | conn = &uip_conns[c];
|
---|
434 | if(conn->tcpstateflags != UIP_CLOSED &&
|
---|
435 | conn->lport == htons(lastport)) {
|
---|
436 | goto again;
|
---|
437 | }
|
---|
438 | }
|
---|
439 |
|
---|
440 | conn = 0;
|
---|
441 | for(c = 0; c < UIP_CONNS; ++c) {
|
---|
442 | cconn = &uip_conns[c];
|
---|
443 | if(cconn->tcpstateflags == UIP_CLOSED) {
|
---|
444 | conn = cconn;
|
---|
445 | break;
|
---|
446 | }
|
---|
447 | if(cconn->tcpstateflags == UIP_TIME_WAIT) {
|
---|
448 | if(conn == 0 ||
|
---|
449 | cconn->timer > conn->timer) {
|
---|
450 | conn = cconn;
|
---|
451 | }
|
---|
452 | }
|
---|
453 | }
|
---|
454 |
|
---|
455 | if(conn == 0) {
|
---|
456 | return 0;
|
---|
457 | }
|
---|
458 |
|
---|
459 | conn->tcpstateflags = UIP_SYN_SENT;
|
---|
460 |
|
---|
461 | conn->snd_nxt[0] = iss[0];
|
---|
462 | conn->snd_nxt[1] = iss[1];
|
---|
463 | conn->snd_nxt[2] = iss[2];
|
---|
464 | conn->snd_nxt[3] = iss[3];
|
---|
465 |
|
---|
466 | conn->initialmss = conn->mss = UIP_TCP_MSS;
|
---|
467 |
|
---|
468 | conn->len = 1; /* TCP length of the SYN is one. */
|
---|
469 | conn->nrtx = 0;
|
---|
470 | conn->timer = 1; /* Send the SYN next time around. */
|
---|
471 | conn->rto = UIP_RTO;
|
---|
472 | conn->sa = 0;
|
---|
473 | conn->sv = 16; /* Initial value of the RTT variance. */
|
---|
474 | conn->lport = htons(lastport);
|
---|
475 | conn->rport = rport;
|
---|
476 | uip_ipaddr_copy(&conn->ripaddr, ripaddr);
|
---|
477 |
|
---|
478 | return conn;
|
---|
479 | }
|
---|
480 | #endif /* UIP_ACTIVE_OPEN */
|
---|
481 | /*---------------------------------------------------------------------------*/
|
---|
482 | #if UIP_UDP
|
---|
483 | struct uip_udp_conn *
|
---|
484 | uip_udp_new(uip_ipaddr_t *ripaddr, uint16_t rport)
|
---|
485 | {
|
---|
486 | register struct uip_udp_conn *conn;
|
---|
487 |
|
---|
488 | /* Find an unused local port. */
|
---|
489 | again:
|
---|
490 | ++lastport;
|
---|
491 |
|
---|
492 | if(lastport >= 32000) {
|
---|
493 | lastport = 4096;
|
---|
494 | }
|
---|
495 |
|
---|
496 | for(c = 0; c < UIP_UDP_CONNS; ++c) {
|
---|
497 | if(uip_udp_conns[c].lport == htons(lastport)) {
|
---|
498 | goto again;
|
---|
499 | }
|
---|
500 | }
|
---|
501 |
|
---|
502 |
|
---|
503 | conn = 0;
|
---|
504 | for(c = 0; c < UIP_UDP_CONNS; ++c) {
|
---|
505 | if(uip_udp_conns[c].lport == 0) {
|
---|
506 | conn = &uip_udp_conns[c];
|
---|
507 | break;
|
---|
508 | }
|
---|
509 | }
|
---|
510 |
|
---|
511 | if(conn == 0) {
|
---|
512 | return 0;
|
---|
513 | }
|
---|
514 |
|
---|
515 | conn->lport = HTONS(lastport);
|
---|
516 | conn->rport = rport;
|
---|
517 | if(ripaddr == NULL) {
|
---|
518 | memset(conn->ripaddr, 0, sizeof(uip_ipaddr_t));
|
---|
519 | } else {
|
---|
520 | uip_ipaddr_copy(&conn->ripaddr, ripaddr);
|
---|
521 | }
|
---|
522 | conn->ttl = UIP_TTL;
|
---|
523 |
|
---|
524 | return conn;
|
---|
525 | }
|
---|
526 | #endif /* UIP_UDP */
|
---|
527 | /*---------------------------------------------------------------------------*/
|
---|
528 | void
|
---|
529 | uip_unlisten(uint16_t port)
|
---|
530 | {
|
---|
531 | for(c = 0; c < UIP_LISTENPORTS; ++c) {
|
---|
532 | if(uip_listenports[c] == port) {
|
---|
533 | uip_listenports[c] = 0;
|
---|
534 | return;
|
---|
535 | }
|
---|
536 | }
|
---|
537 | }
|
---|
538 | /*---------------------------------------------------------------------------*/
|
---|
539 | void
|
---|
540 | uip_listen(uint16_t port)
|
---|
541 | {
|
---|
542 | for(c = 0; c < UIP_LISTENPORTS; ++c) {
|
---|
543 | if(uip_listenports[c] == 0) {
|
---|
544 | uip_listenports[c] = port;
|
---|
545 | return;
|
---|
546 | }
|
---|
547 | }
|
---|
548 | }
|
---|
549 | /*---------------------------------------------------------------------------*/
|
---|
550 | /* XXX: IP fragment reassembly: not well-tested. */
|
---|
551 |
|
---|
552 | #if UIP_REASSEMBLY && !UIP_CONF_IPV6
|
---|
553 | #define UIP_REASS_BUFSIZE (UIP_BUFSIZE - UIP_LLH_LEN)
|
---|
554 | static uint8_t uip_reassbuf[UIP_REASS_BUFSIZE];
|
---|
555 | static uint8_t uip_reassbitmap[UIP_REASS_BUFSIZE / (8 * 8)];
|
---|
556 | static const uint8_t bitmap_bits[8] = {0xff, 0x7f, 0x3f, 0x1f,
|
---|
557 | 0x0f, 0x07, 0x03, 0x01};
|
---|
558 | static uint16_t uip_reasslen;
|
---|
559 | static uint8_t uip_reassflags;
|
---|
560 | #define UIP_REASS_FLAG_LASTFRAG 0x01
|
---|
561 | static uint8_t uip_reasstmr;
|
---|
562 |
|
---|
563 | #define IP_MF 0x20
|
---|
564 |
|
---|
565 | static uint8_t
|
---|
566 | uip_reass(void)
|
---|
567 | {
|
---|
568 | uint16_t offset, len;
|
---|
569 | uint16_t i;
|
---|
570 |
|
---|
571 | /* If ip_reasstmr is zero, no packet is present in the buffer, so we
|
---|
572 | write the IP header of the fragment into the reassembly
|
---|
573 | buffer. The timer is updated with the maximum age. */
|
---|
574 | if(uip_reasstmr == 0) {
|
---|
575 | memcpy(uip_reassbuf, &BUF->vhl, UIP_IPH_LEN);
|
---|
576 | uip_reasstmr = UIP_REASS_MAXAGE;
|
---|
577 | uip_reassflags = 0;
|
---|
578 | /* Clear the bitmap. */
|
---|
579 | memset(uip_reassbitmap, 0, sizeof(uip_reassbitmap));
|
---|
580 | }
|
---|
581 |
|
---|
582 | /* Check if the incoming fragment matches the one currently present
|
---|
583 | in the reasembly buffer. If so, we proceed with copying the
|
---|
584 | fragment into the buffer. */
|
---|
585 | if(BUF->srcipaddr[0] == FBUF->srcipaddr[0] &&
|
---|
586 | BUF->srcipaddr[1] == FBUF->srcipaddr[1] &&
|
---|
587 | BUF->destipaddr[0] == FBUF->destipaddr[0] &&
|
---|
588 | BUF->destipaddr[1] == FBUF->destipaddr[1] &&
|
---|
589 | BUF->ipid[0] == FBUF->ipid[0] &&
|
---|
590 | BUF->ipid[1] == FBUF->ipid[1]) {
|
---|
591 |
|
---|
592 | len = (BUF->len[0] << 8) + BUF->len[1] - (BUF->vhl & 0x0f) * 4;
|
---|
593 | offset = (((BUF->ipoffset[0] & 0x3f) << 8) + BUF->ipoffset[1]) * 8;
|
---|
594 |
|
---|
595 | /* If the offset or the offset + fragment length overflows the
|
---|
596 | reassembly buffer, we discard the entire packet. */
|
---|
597 | if(offset > UIP_REASS_BUFSIZE ||
|
---|
598 | offset + len > UIP_REASS_BUFSIZE) {
|
---|
599 | uip_reasstmr = 0;
|
---|
600 | goto nullreturn;
|
---|
601 | }
|
---|
602 |
|
---|
603 | /* Copy the fragment into the reassembly buffer, at the right
|
---|
604 | offset. */
|
---|
605 | memcpy(&uip_reassbuf[UIP_IPH_LEN + offset],
|
---|
606 | (char *)BUF + (int)((BUF->vhl & 0x0f) * 4),
|
---|
607 | len);
|
---|
608 |
|
---|
609 | /* Update the bitmap. */
|
---|
610 | if(offset / (8 * 8) == (offset + len) / (8 * 8)) {
|
---|
611 | /* If the two endpoints are in the same byte, we only update
|
---|
612 | that byte. */
|
---|
613 |
|
---|
614 | uip_reassbitmap[offset / (8 * 8)] |=
|
---|
615 | bitmap_bits[(offset / 8 ) & 7] &
|
---|
616 | ~bitmap_bits[((offset + len) / 8 ) & 7];
|
---|
617 | } else {
|
---|
618 | /* If the two endpoints are in different bytes, we update the
|
---|
619 | bytes in the endpoints and fill the stuff inbetween with
|
---|
620 | 0xff. */
|
---|
621 | uip_reassbitmap[offset / (8 * 8)] |=
|
---|
622 | bitmap_bits[(offset / 8 ) & 7];
|
---|
623 | for(i = 1 + offset / (8 * 8); i < (offset + len) / (8 * 8); ++i) {
|
---|
624 | uip_reassbitmap[i] = 0xff;
|
---|
625 | }
|
---|
626 | uip_reassbitmap[(offset + len) / (8 * 8)] |=
|
---|
627 | ~bitmap_bits[((offset + len) / 8 ) & 7];
|
---|
628 | }
|
---|
629 |
|
---|
630 | /* If this fragment has the More Fragments flag set to zero, we
|
---|
631 | know that this is the last fragment, so we can calculate the
|
---|
632 | size of the entire packet. We also set the
|
---|
633 | IP_REASS_FLAG_LASTFRAG flag to indicate that we have received
|
---|
634 | the final fragment. */
|
---|
635 |
|
---|
636 | if((BUF->ipoffset[0] & IP_MF) == 0) {
|
---|
637 | uip_reassflags |= UIP_REASS_FLAG_LASTFRAG;
|
---|
638 | uip_reasslen = offset + len;
|
---|
639 | }
|
---|
640 |
|
---|
641 | /* Finally, we check if we have a full packet in the buffer. We do
|
---|
642 | this by checking if we have the last fragment and if all bits
|
---|
643 | in the bitmap are set. */
|
---|
644 | if(uip_reassflags & UIP_REASS_FLAG_LASTFRAG) {
|
---|
645 | /* Check all bytes up to and including all but the last byte in
|
---|
646 | the bitmap. */
|
---|
647 | for(i = 0; i < uip_reasslen / (8 * 8) - 1; ++i) {
|
---|
648 | if(uip_reassbitmap[i] != 0xff) {
|
---|
649 | goto nullreturn;
|
---|
650 | }
|
---|
651 | }
|
---|
652 | /* Check the last byte in the bitmap. It should contain just the
|
---|
653 | right amount of bits. */
|
---|
654 | if(uip_reassbitmap[uip_reasslen / (8 * 8)] !=
|
---|
655 | (uint8_t)~bitmap_bits[uip_reasslen / 8 & 7]) {
|
---|
656 | goto nullreturn;
|
---|
657 | }
|
---|
658 |
|
---|
659 | /* If we have come this far, we have a full packet in the
|
---|
660 | buffer, so we allocate a pbuf and copy the packet into it. We
|
---|
661 | also reset the timer. */
|
---|
662 | uip_reasstmr = 0;
|
---|
663 | memcpy(BUF, FBUF, uip_reasslen);
|
---|
664 |
|
---|
665 | /* Pretend to be a "normal" (i.e., not fragmented) IP packet
|
---|
666 | from now on. */
|
---|
667 | BUF->ipoffset[0] = BUF->ipoffset[1] = 0;
|
---|
668 | BUF->len[0] = uip_reasslen >> 8;
|
---|
669 | BUF->len[1] = uip_reasslen & 0xff;
|
---|
670 | BUF->ipchksum = 0;
|
---|
671 | BUF->ipchksum = ~(uip_ipchksum());
|
---|
672 |
|
---|
673 | return uip_reasslen;
|
---|
674 | }
|
---|
675 | }
|
---|
676 |
|
---|
677 | nullreturn:
|
---|
678 | return 0;
|
---|
679 | }
|
---|
680 | #endif /* UIP_REASSEMBLY */
|
---|
681 | /*---------------------------------------------------------------------------*/
|
---|
682 | static void
|
---|
683 | uip_add_rcv_nxt(uint16_t n)
|
---|
684 | {
|
---|
685 | uip_add32(uip_conn->rcv_nxt, n);
|
---|
686 | uip_conn->rcv_nxt[0] = uip_acc32[0];
|
---|
687 | uip_conn->rcv_nxt[1] = uip_acc32[1];
|
---|
688 | uip_conn->rcv_nxt[2] = uip_acc32[2];
|
---|
689 | uip_conn->rcv_nxt[3] = uip_acc32[3];
|
---|
690 | }
|
---|
691 | /*---------------------------------------------------------------------------*/
|
---|
692 | void
|
---|
693 | uip_process(uint8_t flag)
|
---|
694 | {
|
---|
695 | register struct uip_conn *uip_connr = uip_conn;
|
---|
696 |
|
---|
697 | #if UIP_UDP
|
---|
698 | if(flag == UIP_UDP_SEND_CONN) {
|
---|
699 | goto udp_send;
|
---|
700 | }
|
---|
701 | #endif /* UIP_UDP */
|
---|
702 |
|
---|
703 | uip_sappdata = uip_appdata = &uip_buf[UIP_IPTCPH_LEN + UIP_LLH_LEN];
|
---|
704 |
|
---|
705 | /* Check if we were invoked because of a poll request for a
|
---|
706 | particular connection. */
|
---|
707 | if(flag == UIP_POLL_REQUEST) {
|
---|
708 | if((uip_connr->tcpstateflags & UIP_TS_MASK) == UIP_ESTABLISHED &&
|
---|
709 | !uip_outstanding(uip_connr)) {
|
---|
710 | uip_flags = UIP_POLL;
|
---|
711 | UIP_APPCALL();
|
---|
712 | goto appsend;
|
---|
713 | }
|
---|
714 | goto drop;
|
---|
715 |
|
---|
716 | /* Check if we were invoked because of the perodic timer fireing. */
|
---|
717 | } else if(flag == UIP_TIMER) {
|
---|
718 | #if UIP_REASSEMBLY
|
---|
719 | if(uip_reasstmr != 0) {
|
---|
720 | --uip_reasstmr;
|
---|
721 | }
|
---|
722 | #endif /* UIP_REASSEMBLY */
|
---|
723 | /* Increase the initial sequence number. */
|
---|
724 | if(++iss[3] == 0) {
|
---|
725 | if(++iss[2] == 0) {
|
---|
726 | if(++iss[1] == 0) {
|
---|
727 | ++iss[0];
|
---|
728 | }
|
---|
729 | }
|
---|
730 | }
|
---|
731 |
|
---|
732 | /* Reset the length variables. */
|
---|
733 | uip_len = 0;
|
---|
734 | uip_slen = 0;
|
---|
735 |
|
---|
736 | /* Check if the connection is in a state in which we simply wait
|
---|
737 | for the connection to time out. If so, we increase the
|
---|
738 | connection's timer and remove the connection if it times
|
---|
739 | out. */
|
---|
740 | if(uip_connr->tcpstateflags == UIP_TIME_WAIT ||
|
---|
741 | uip_connr->tcpstateflags == UIP_FIN_WAIT_2) {
|
---|
742 | ++(uip_connr->timer);
|
---|
743 | if(uip_connr->timer == UIP_TIME_WAIT_TIMEOUT) {
|
---|
744 | uip_connr->tcpstateflags = UIP_CLOSED;
|
---|
745 | }
|
---|
746 | } else if(uip_connr->tcpstateflags != UIP_CLOSED) {
|
---|
747 | /* If the connection has outstanding data, we increase the
|
---|
748 | connection's timer and see if it has reached the RTO value
|
---|
749 | in which case we retransmit. */
|
---|
750 | if(uip_outstanding(uip_connr)) {
|
---|
751 | if(uip_connr->timer-- == 0) {
|
---|
752 | if(uip_connr->nrtx == UIP_MAXRTX ||
|
---|
753 | ((uip_connr->tcpstateflags == UIP_SYN_SENT ||
|
---|
754 | uip_connr->tcpstateflags == UIP_SYN_RCVD) &&
|
---|
755 | uip_connr->nrtx == UIP_MAXSYNRTX)) {
|
---|
756 | uip_connr->tcpstateflags = UIP_CLOSED;
|
---|
757 |
|
---|
758 | /* We call UIP_APPCALL() with uip_flags set to
|
---|
759 | UIP_TIMEDOUT to inform the application that the
|
---|
760 | connection has timed out. */
|
---|
761 | uip_flags = UIP_TIMEDOUT;
|
---|
762 | UIP_APPCALL();
|
---|
763 |
|
---|
764 | /* We also send a reset packet to the remote host. */
|
---|
765 | BUF->flags = TCP_RST | TCP_ACK;
|
---|
766 | goto tcp_send_nodata;
|
---|
767 | }
|
---|
768 |
|
---|
769 | /* Exponential backoff. */
|
---|
770 | uip_connr->timer = UIP_RTO << (uip_connr->nrtx > 4?
|
---|
771 | 4:
|
---|
772 | uip_connr->nrtx);
|
---|
773 | ++(uip_connr->nrtx);
|
---|
774 |
|
---|
775 | /* Ok, so we need to retransmit. We do this differently
|
---|
776 | depending on which state we are in. In ESTABLISHED, we
|
---|
777 | call upon the application so that it may prepare the
|
---|
778 | data for the retransmit. In SYN_RCVD, we resend the
|
---|
779 | SYNACK that we sent earlier and in LAST_ACK we have to
|
---|
780 | retransmit our FINACK. */
|
---|
781 | UIP_STAT(++uip_stat.tcp.rexmit);
|
---|
782 | switch(uip_connr->tcpstateflags & UIP_TS_MASK) {
|
---|
783 | case UIP_SYN_RCVD:
|
---|
784 | /* In the SYN_RCVD state, we should retransmit our
|
---|
785 | SYNACK. */
|
---|
786 | goto tcp_send_synack;
|
---|
787 |
|
---|
788 | #if UIP_ACTIVE_OPEN
|
---|
789 | case UIP_SYN_SENT:
|
---|
790 | /* In the SYN_SENT state, we retransmit out SYN. */
|
---|
791 | BUF->flags = 0;
|
---|
792 | goto tcp_send_syn;
|
---|
793 | #endif /* UIP_ACTIVE_OPEN */
|
---|
794 |
|
---|
795 | case UIP_ESTABLISHED:
|
---|
796 | /* In the ESTABLISHED state, we call upon the application
|
---|
797 | to do the actual retransmit after which we jump into
|
---|
798 | the code for sending out the packet (the apprexmit
|
---|
799 | label). */
|
---|
800 | uip_flags = UIP_REXMIT;
|
---|
801 | UIP_APPCALL();
|
---|
802 | goto apprexmit;
|
---|
803 |
|
---|
804 | case UIP_FIN_WAIT_1:
|
---|
805 | case UIP_CLOSING:
|
---|
806 | case UIP_LAST_ACK:
|
---|
807 | /* In all these states we should retransmit a FINACK. */
|
---|
808 | goto tcp_send_finack;
|
---|
809 |
|
---|
810 | }
|
---|
811 | }
|
---|
812 | } else if((uip_connr->tcpstateflags & UIP_TS_MASK) == UIP_ESTABLISHED) {
|
---|
813 | /* If there was no need for a retransmission, we poll the
|
---|
814 | application for new data. */
|
---|
815 | uip_flags = UIP_POLL;
|
---|
816 | UIP_APPCALL();
|
---|
817 | goto appsend;
|
---|
818 | }
|
---|
819 | }
|
---|
820 | goto drop;
|
---|
821 | }
|
---|
822 | #if UIP_UDP
|
---|
823 | if(flag == UIP_UDP_TIMER) {
|
---|
824 | if(uip_udp_conn->lport != 0) {
|
---|
825 | uip_conn = NULL;
|
---|
826 | uip_sappdata = uip_appdata = &uip_buf[UIP_LLH_LEN + UIP_IPUDPH_LEN];
|
---|
827 | uip_len = uip_slen = 0;
|
---|
828 | uip_flags = UIP_POLL;
|
---|
829 | UIP_UDP_APPCALL();
|
---|
830 | goto udp_send;
|
---|
831 | } else {
|
---|
832 | goto drop;
|
---|
833 | }
|
---|
834 | }
|
---|
835 | #endif
|
---|
836 |
|
---|
837 | /* This is where the input processing starts. */
|
---|
838 | UIP_STAT(++uip_stat.ip.recv);
|
---|
839 |
|
---|
840 | /* Start of IP input header processing code. */
|
---|
841 |
|
---|
842 | #if UIP_CONF_IPV6
|
---|
843 | /* Check validity of the IP header. */
|
---|
844 | if((BUF->vtc & 0xf0) != 0x60) { /* IP version and header length. */
|
---|
845 | UIP_STAT(++uip_stat.ip.drop);
|
---|
846 | UIP_STAT(++uip_stat.ip.vhlerr);
|
---|
847 | UIP_LOG("ipv6: invalid version.");
|
---|
848 | goto drop;
|
---|
849 | }
|
---|
850 | #else /* UIP_CONF_IPV6 */
|
---|
851 | /* Check validity of the IP header. */
|
---|
852 | if(BUF->vhl != 0x45) { /* IP version and header length. */
|
---|
853 | UIP_STAT(++uip_stat.ip.drop);
|
---|
854 | UIP_STAT(++uip_stat.ip.vhlerr);
|
---|
855 | UIP_LOG("ip: invalid version or header length.");
|
---|
856 | goto drop;
|
---|
857 | }
|
---|
858 | #endif /* UIP_CONF_IPV6 */
|
---|
859 |
|
---|
860 | /* Check the size of the packet. If the size reported to us in
|
---|
861 | uip_len is smaller the size reported in the IP header, we assume
|
---|
862 | that the packet has been corrupted in transit. If the size of
|
---|
863 | uip_len is larger than the size reported in the IP packet header,
|
---|
864 | the packet has been padded and we set uip_len to the correct
|
---|
865 | value.. */
|
---|
866 |
|
---|
867 | if((BUF->len[0] << 8) + BUF->len[1] <= uip_len) {
|
---|
868 | uip_len = (BUF->len[0] << 8) + BUF->len[1];
|
---|
869 | #if UIP_CONF_IPV6
|
---|
870 | uip_len += 40; /* The length reported in the IPv6 header is the
|
---|
871 | length of the payload that follows the
|
---|
872 | header. However, uIP uses the uip_len variable
|
---|
873 | for holding the size of the entire packet,
|
---|
874 | including the IP header. For IPv4 this is not a
|
---|
875 | problem as the length field in the IPv4 header
|
---|
876 | contains the length of the entire packet. But
|
---|
877 | for IPv6 we need to add the size of the IPv6
|
---|
878 | header (40 bytes). */
|
---|
879 | #endif /* UIP_CONF_IPV6 */
|
---|
880 | } else {
|
---|
881 | UIP_LOG("ip: packet shorter than reported in IP header.");
|
---|
882 | goto drop;
|
---|
883 | }
|
---|
884 |
|
---|
885 | #if !UIP_CONF_IPV6
|
---|
886 | /* Check the fragment flag. */
|
---|
887 | if((BUF->ipoffset[0] & 0x3f) != 0 ||
|
---|
888 | BUF->ipoffset[1] != 0) {
|
---|
889 | #if UIP_REASSEMBLY
|
---|
890 | uip_len = uip_reass();
|
---|
891 | if(uip_len == 0) {
|
---|
892 | goto drop;
|
---|
893 | }
|
---|
894 | #else /* UIP_REASSEMBLY */
|
---|
895 | UIP_STAT(++uip_stat.ip.drop);
|
---|
896 | UIP_STAT(++uip_stat.ip.fragerr);
|
---|
897 | UIP_LOG("ip: fragment dropped.");
|
---|
898 | goto drop;
|
---|
899 | #endif /* UIP_REASSEMBLY */
|
---|
900 | }
|
---|
901 | #endif /* UIP_CONF_IPV6 */
|
---|
902 |
|
---|
903 | if(uip_ipaddr_cmp(uip_hostaddr, all_zeroes_addr)) {
|
---|
904 | /* If we are configured to use ping IP address configuration and
|
---|
905 | hasn't been assigned an IP address yet, we accept all ICMP
|
---|
906 | packets. */
|
---|
907 | #if UIP_PINGADDRCONF && !UIP_CONF_IPV6
|
---|
908 | if(BUF->proto == UIP_PROTO_ICMP) {
|
---|
909 | UIP_LOG("ip: possible ping config packet received.");
|
---|
910 | goto icmp_input;
|
---|
911 | } else {
|
---|
912 | UIP_LOG("ip: packet dropped since no address assigned.");
|
---|
913 | goto drop;
|
---|
914 | }
|
---|
915 | #endif /* UIP_PINGADDRCONF */
|
---|
916 |
|
---|
917 | } else {
|
---|
918 | /* If IP broadcast support is configured, we check for a broadcast
|
---|
919 | UDP packet, which may be destined to us. */
|
---|
920 | #if UIP_BROADCAST
|
---|
921 | DEBUG_PRINTF("UDP IP checksum 0x%04x\n", uip_ipchksum());
|
---|
922 | if(BUF->proto == UIP_PROTO_UDP &&
|
---|
923 | (uip_ipaddr_cmp(BUF->destipaddr, all_ones_addr) ||
|
---|
924 | uip_ismulticast(BUF->destipaddr))
|
---|
925 | /*&&
|
---|
926 | uip_ipchksum() == 0xffff*/) {
|
---|
927 | goto udp_input;
|
---|
928 | }
|
---|
929 | #endif /* UIP_BROADCAST */
|
---|
930 |
|
---|
931 | /* Check if the packet is destined for our IP address. */
|
---|
932 | #if !UIP_CONF_IPV6
|
---|
933 | if(!uip_ipaddr_cmp(BUF->destipaddr, uip_hostaddr)) {
|
---|
934 | UIP_STAT(++uip_stat.ip.drop);
|
---|
935 | goto drop;
|
---|
936 | }
|
---|
937 | #else /* UIP_CONF_IPV6 */
|
---|
938 | /* For IPv6, packet reception is a little trickier as we need to
|
---|
939 | make sure that we listen to certain multicast addresses (all
|
---|
940 | hosts multicast address, and the solicited-node multicast
|
---|
941 | address) as well. However, we will cheat here and accept all
|
---|
942 | multicast packets that are sent to the ff02::/16 addresses. */
|
---|
943 | if(!uip_ipaddr_cmp(BUF->destipaddr, uip_hostaddr) &&
|
---|
944 | BUF->destipaddr[0] != HTONS(0xff02)) {
|
---|
945 | UIP_STAT(++uip_stat.ip.drop);
|
---|
946 | goto drop;
|
---|
947 | }
|
---|
948 | #endif /* UIP_CONF_IPV6 */
|
---|
949 | }
|
---|
950 |
|
---|
951 | #if !UIP_CONF_IPV6
|
---|
952 | if(uip_ipchksum() != 0xffff) { /* Compute and check the IP header
|
---|
953 | checksum. */
|
---|
954 | UIP_STAT(++uip_stat.ip.drop);
|
---|
955 | UIP_STAT(++uip_stat.ip.chkerr);
|
---|
956 | UIP_LOG("ip: bad checksum.");
|
---|
957 | goto drop;
|
---|
958 | }
|
---|
959 | #endif /* UIP_CONF_IPV6 */
|
---|
960 |
|
---|
961 | if(BUF->proto == UIP_PROTO_TCP) { /* Check for TCP packet. If so,
|
---|
962 | proceed with TCP input
|
---|
963 | processing. */
|
---|
964 | goto tcp_input;
|
---|
965 | }
|
---|
966 |
|
---|
967 | #if UIP_UDP
|
---|
968 | if(BUF->proto == UIP_PROTO_UDP) {
|
---|
969 | goto udp_input;
|
---|
970 | }
|
---|
971 | #endif /* UIP_UDP */
|
---|
972 |
|
---|
973 | #if !UIP_CONF_IPV6
|
---|
974 | /* ICMPv4 processing code follows. */
|
---|
975 | if(BUF->proto != UIP_PROTO_ICMP) { /* We only allow ICMP packets from
|
---|
976 | here. */
|
---|
977 | UIP_STAT(++uip_stat.ip.drop);
|
---|
978 | UIP_STAT(++uip_stat.ip.protoerr);
|
---|
979 | UIP_LOG("ip: neither tcp nor icmp.");
|
---|
980 | goto drop;
|
---|
981 | }
|
---|
982 |
|
---|
983 | #if UIP_PINGADDRCONF
|
---|
984 | icmp_input:
|
---|
985 | #endif /* UIP_PINGADDRCONF */
|
---|
986 | UIP_STAT(++uip_stat.icmp.recv);
|
---|
987 |
|
---|
988 | /* ICMP echo (i.e., ping) processing. This is simple, we only change
|
---|
989 | the ICMP type from ECHO to ECHO_REPLY and adjust the ICMP
|
---|
990 | checksum before we return the packet. */
|
---|
991 | if(ICMPBUF->type != ICMP_ECHO) {
|
---|
992 | UIP_STAT(++uip_stat.icmp.drop);
|
---|
993 | UIP_STAT(++uip_stat.icmp.typeerr);
|
---|
994 | UIP_LOG("icmp: not icmp echo.");
|
---|
995 | goto drop;
|
---|
996 | }
|
---|
997 |
|
---|
998 | /* If we are configured to use ping IP address assignment, we use
|
---|
999 | the destination IP address of this ping packet and assign it to
|
---|
1000 | ourself. */
|
---|
1001 | #if UIP_PINGADDRCONF
|
---|
1002 | if((uip_hostaddr[0] | uip_hostaddr[1]) == 0) {
|
---|
1003 | uip_hostaddr[0] = BUF->destipaddr[0];
|
---|
1004 | uip_hostaddr[1] = BUF->destipaddr[1];
|
---|
1005 | }
|
---|
1006 | #endif /* UIP_PINGADDRCONF */
|
---|
1007 |
|
---|
1008 | ICMPBUF->type = ICMP_ECHO_REPLY;
|
---|
1009 |
|
---|
1010 | if(ICMPBUF->icmpchksum >= HTONS(0xffff - (ICMP_ECHO << 8))) {
|
---|
1011 | ICMPBUF->icmpchksum += HTONS(ICMP_ECHO << 8) + 1;
|
---|
1012 | } else {
|
---|
1013 | ICMPBUF->icmpchksum += HTONS(ICMP_ECHO << 8);
|
---|
1014 | }
|
---|
1015 |
|
---|
1016 | /* Swap IP addresses. */
|
---|
1017 | uip_ipaddr_copy(BUF->destipaddr, BUF->srcipaddr);
|
---|
1018 | uip_ipaddr_copy(BUF->srcipaddr, uip_hostaddr);
|
---|
1019 |
|
---|
1020 | UIP_STAT(++uip_stat.icmp.sent);
|
---|
1021 | goto send;
|
---|
1022 |
|
---|
1023 | /* End of IPv4 input header processing code. */
|
---|
1024 | #else /* !UIP_CONF_IPV6 */
|
---|
1025 |
|
---|
1026 | /* This is IPv6 ICMPv6 processing code. */
|
---|
1027 | DEBUG_PRINTF("icmp6_input: length %d\n", uip_len);
|
---|
1028 |
|
---|
1029 | if(BUF->proto != UIP_PROTO_ICMP6) { /* We only allow ICMPv6 packets from
|
---|
1030 | here. */
|
---|
1031 | UIP_STAT(++uip_stat.ip.drop);
|
---|
1032 | UIP_STAT(++uip_stat.ip.protoerr);
|
---|
1033 | UIP_LOG("ip: neither tcp nor icmp6.");
|
---|
1034 | goto drop;
|
---|
1035 | }
|
---|
1036 |
|
---|
1037 | UIP_STAT(++uip_stat.icmp.recv);
|
---|
1038 |
|
---|
1039 | /* If we get a neighbor solicitation for our address we should send
|
---|
1040 | a neighbor advertisement message back. */
|
---|
1041 | if(ICMPBUF->type == ICMP6_NEIGHBOR_SOLICITATION) {
|
---|
1042 | if(uip_ipaddr_cmp(ICMPBUF->icmp6data, uip_hostaddr)) {
|
---|
1043 |
|
---|
1044 | if(ICMPBUF->options[0] == ICMP6_OPTION_SOURCE_LINK_ADDRESS) {
|
---|
1045 | /* Save the sender's address in our neighbor list. */
|
---|
1046 | uip_neighbor_add(ICMPBUF->srcipaddr, &(ICMPBUF->options[2]));
|
---|
1047 | }
|
---|
1048 |
|
---|
1049 | /* We should now send a neighbor advertisement back to where the
|
---|
1050 | neighbor solicication came from. */
|
---|
1051 | ICMPBUF->type = ICMP6_NEIGHBOR_ADVERTISEMENT;
|
---|
1052 | ICMPBUF->flags = ICMP6_FLAG_S; /* Solicited flag. */
|
---|
1053 |
|
---|
1054 | ICMPBUF->reserved1 = ICMPBUF->reserved2 = ICMPBUF->reserved3 = 0;
|
---|
1055 |
|
---|
1056 | uip_ipaddr_copy(ICMPBUF->destipaddr, ICMPBUF->srcipaddr);
|
---|
1057 | uip_ipaddr_copy(ICMPBUF->srcipaddr, uip_hostaddr);
|
---|
1058 | ICMPBUF->options[0] = ICMP6_OPTION_TARGET_LINK_ADDRESS;
|
---|
1059 | ICMPBUF->options[1] = 1; /* Options length, 1 = 8 bytes. */
|
---|
1060 | memcpy(&(ICMPBUF->options[2]), &uip_ethaddr, sizeof(uip_ethaddr));
|
---|
1061 | ICMPBUF->icmpchksum = 0;
|
---|
1062 | ICMPBUF->icmpchksum = ~uip_icmp6chksum();
|
---|
1063 | goto send;
|
---|
1064 |
|
---|
1065 | }
|
---|
1066 | goto drop;
|
---|
1067 | } else if(ICMPBUF->type == ICMP6_ECHO) {
|
---|
1068 | /* ICMP echo (i.e., ping) processing. This is simple, we only
|
---|
1069 | change the ICMP type from ECHO to ECHO_REPLY and update the
|
---|
1070 | ICMP checksum before we return the packet. */
|
---|
1071 |
|
---|
1072 | ICMPBUF->type = ICMP6_ECHO_REPLY;
|
---|
1073 |
|
---|
1074 | uip_ipaddr_copy(BUF->destipaddr, BUF->srcipaddr);
|
---|
1075 | uip_ipaddr_copy(BUF->srcipaddr, uip_hostaddr);
|
---|
1076 | ICMPBUF->icmpchksum = 0;
|
---|
1077 | ICMPBUF->icmpchksum = ~uip_icmp6chksum();
|
---|
1078 |
|
---|
1079 | UIP_STAT(++uip_stat.icmp.sent);
|
---|
1080 | goto send;
|
---|
1081 | } else {
|
---|
1082 | DEBUG_PRINTF("Unknown icmp6 message type %d\n", ICMPBUF->type);
|
---|
1083 | UIP_STAT(++uip_stat.icmp.drop);
|
---|
1084 | UIP_STAT(++uip_stat.icmp.typeerr);
|
---|
1085 | UIP_LOG("icmp: unknown ICMP message.");
|
---|
1086 | goto drop;
|
---|
1087 | }
|
---|
1088 |
|
---|
1089 | /* End of IPv6 ICMP processing. */
|
---|
1090 |
|
---|
1091 | #endif /* !UIP_CONF_IPV6 */
|
---|
1092 |
|
---|
1093 | #if UIP_UDP
|
---|
1094 | /* UDP input processing. */
|
---|
1095 | udp_input:
|
---|
1096 | /* UDP processing is really just a hack. We don't do anything to the
|
---|
1097 | UDP/IP headers, but let the UDP application do all the hard
|
---|
1098 | work. If the application sets uip_slen, it has a packet to
|
---|
1099 | send. */
|
---|
1100 | #if UIP_UDP_CHECKSUMS
|
---|
1101 | uip_len = uip_len - UIP_IPUDPH_LEN;
|
---|
1102 | uip_appdata = &uip_buf[UIP_LLH_LEN + UIP_IPUDPH_LEN];
|
---|
1103 | if(UDPBUF->udpchksum != 0 && uip_udpchksum() != 0xffff) {
|
---|
1104 | UIP_STAT(++uip_stat.udp.drop);
|
---|
1105 | UIP_STAT(++uip_stat.udp.chkerr);
|
---|
1106 | UIP_LOG("udp: bad checksum.");
|
---|
1107 | goto drop;
|
---|
1108 | }
|
---|
1109 | #else /* UIP_UDP_CHECKSUMS */
|
---|
1110 | uip_len = uip_len - UIP_IPUDPH_LEN;
|
---|
1111 | #endif /* UIP_UDP_CHECKSUMS */
|
---|
1112 |
|
---|
1113 | /* Demultiplex this UDP packet between the UDP "connections". */
|
---|
1114 | for(uip_udp_conn = &uip_udp_conns[0];
|
---|
1115 | uip_udp_conn < &uip_udp_conns[UIP_UDP_CONNS];
|
---|
1116 | ++uip_udp_conn) {
|
---|
1117 | /* If the local UDP port is non-zero, the connection is considered
|
---|
1118 | to be used. If so, the local port number is checked against the
|
---|
1119 | destination port number in the received packet. If the two port
|
---|
1120 | numbers match, the remote port number is checked if the
|
---|
1121 | connection is bound to a remote port. Finally, if the
|
---|
1122 | connection is bound to a remote IP address, the source IP
|
---|
1123 | address of the packet is checked. */
|
---|
1124 | if(uip_udp_conn->lport != 0 &&
|
---|
1125 | UDPBUF->destport == uip_udp_conn->lport &&
|
---|
1126 | (uip_udp_conn->rport == 0 ||
|
---|
1127 | UDPBUF->srcport == uip_udp_conn->rport) &&
|
---|
1128 | (uip_ipaddr_cmp(uip_udp_conn->ripaddr, all_zeroes_addr) ||
|
---|
1129 | uip_ipaddr_cmp(uip_udp_conn->ripaddr, all_ones_addr) ||
|
---|
1130 | uip_ipaddr_cmp(BUF->srcipaddr, uip_udp_conn->ripaddr))) {
|
---|
1131 | goto udp_found;
|
---|
1132 | }
|
---|
1133 | }
|
---|
1134 | UIP_LOG("udp: no matching connection found");
|
---|
1135 | goto drop;
|
---|
1136 |
|
---|
1137 | udp_found:
|
---|
1138 | uip_conn = NULL;
|
---|
1139 | uip_flags = UIP_NEWDATA;
|
---|
1140 | uip_sappdata = uip_appdata = &uip_buf[UIP_LLH_LEN + UIP_IPUDPH_LEN];
|
---|
1141 | uip_slen = 0;
|
---|
1142 | UIP_UDP_APPCALL();
|
---|
1143 | udp_send:
|
---|
1144 | if(uip_slen == 0) {
|
---|
1145 | goto drop;
|
---|
1146 | }
|
---|
1147 | uip_len = uip_slen + UIP_IPUDPH_LEN;
|
---|
1148 |
|
---|
1149 | #if UIP_CONF_IPV6
|
---|
1150 | /* For IPv6, the IP length field does not include the IPv6 IP header
|
---|
1151 | length. */
|
---|
1152 | BUF->len[0] = ((uip_len - UIP_IPH_LEN) >> 8);
|
---|
1153 | BUF->len[1] = ((uip_len - UIP_IPH_LEN) & 0xff);
|
---|
1154 | #else /* UIP_CONF_IPV6 */
|
---|
1155 | BUF->len[0] = (uip_len >> 8);
|
---|
1156 | BUF->len[1] = (uip_len & 0xff);
|
---|
1157 | #endif /* UIP_CONF_IPV6 */
|
---|
1158 |
|
---|
1159 | BUF->ttl = uip_udp_conn->ttl;
|
---|
1160 | BUF->proto = UIP_PROTO_UDP;
|
---|
1161 |
|
---|
1162 | UDPBUF->udplen = HTONS(uip_slen + UIP_UDPH_LEN);
|
---|
1163 | UDPBUF->udpchksum = 0;
|
---|
1164 |
|
---|
1165 | BUF->srcport = uip_udp_conn->lport;
|
---|
1166 | BUF->destport = uip_udp_conn->rport;
|
---|
1167 |
|
---|
1168 | uip_ipaddr_copy(BUF->srcipaddr, uip_hostaddr);
|
---|
1169 | uip_ipaddr_copy(BUF->destipaddr, uip_udp_conn->ripaddr);
|
---|
1170 |
|
---|
1171 | uip_appdata = &uip_buf[UIP_LLH_LEN + UIP_IPTCPH_LEN];
|
---|
1172 |
|
---|
1173 | #if UIP_UDP_CHECKSUMS
|
---|
1174 | /* Calculate UDP checksum. */
|
---|
1175 | UDPBUF->udpchksum = ~(uip_udpchksum());
|
---|
1176 | if(UDPBUF->udpchksum == 0) {
|
---|
1177 | UDPBUF->udpchksum = 0xffff;
|
---|
1178 | }
|
---|
1179 | #endif /* UIP_UDP_CHECKSUMS */
|
---|
1180 |
|
---|
1181 | goto ip_send_nolen;
|
---|
1182 | #endif /* UIP_UDP */
|
---|
1183 |
|
---|
1184 | /* TCP input processing. */
|
---|
1185 | tcp_input:
|
---|
1186 | UIP_STAT(++uip_stat.tcp.recv);
|
---|
1187 |
|
---|
1188 | /* Start of TCP input header processing code. */
|
---|
1189 |
|
---|
1190 | if(uip_tcpchksum() != 0xffff) { /* Compute and check the TCP
|
---|
1191 | checksum. */
|
---|
1192 | UIP_STAT(++uip_stat.tcp.drop);
|
---|
1193 | UIP_STAT(++uip_stat.tcp.chkerr);
|
---|
1194 | UIP_LOG("tcp: bad checksum.");
|
---|
1195 | goto drop;
|
---|
1196 | }
|
---|
1197 |
|
---|
1198 |
|
---|
1199 | /* Demultiplex this segment. */
|
---|
1200 | /* First check any active connections. */
|
---|
1201 | for(uip_connr = &uip_conns[0]; uip_connr <= &uip_conns[UIP_CONNS - 1];
|
---|
1202 | ++uip_connr) {
|
---|
1203 | if(uip_connr->tcpstateflags != UIP_CLOSED &&
|
---|
1204 | BUF->destport == uip_connr->lport &&
|
---|
1205 | BUF->srcport == uip_connr->rport &&
|
---|
1206 | uip_ipaddr_cmp(BUF->srcipaddr, uip_connr->ripaddr)) {
|
---|
1207 | goto found;
|
---|
1208 | }
|
---|
1209 | }
|
---|
1210 |
|
---|
1211 | /* If we didn't find and active connection that expected the packet,
|
---|
1212 | either this packet is an old duplicate, or this is a SYN packet
|
---|
1213 | destined for a connection in LISTEN. If the SYN flag isn't set,
|
---|
1214 | it is an old packet and we send a RST. */
|
---|
1215 | if((BUF->flags & TCP_CTL) != TCP_SYN) {
|
---|
1216 | goto reset;
|
---|
1217 | }
|
---|
1218 |
|
---|
1219 | tmp16 = BUF->destport;
|
---|
1220 | /* Next, check listening connections. */
|
---|
1221 | for(c = 0; c < UIP_LISTENPORTS; ++c) {
|
---|
1222 | if(tmp16 == uip_listenports[c])
|
---|
1223 | goto found_listen;
|
---|
1224 | }
|
---|
1225 |
|
---|
1226 | /* No matching connection found, so we send a RST packet. */
|
---|
1227 | UIP_STAT(++uip_stat.tcp.synrst);
|
---|
1228 | reset:
|
---|
1229 |
|
---|
1230 | /* We do not send resets in response to resets. */
|
---|
1231 | if(BUF->flags & TCP_RST) {
|
---|
1232 | goto drop;
|
---|
1233 | }
|
---|
1234 |
|
---|
1235 | UIP_STAT(++uip_stat.tcp.rst);
|
---|
1236 |
|
---|
1237 | BUF->flags = TCP_RST | TCP_ACK;
|
---|
1238 | uip_len = UIP_IPTCPH_LEN;
|
---|
1239 | BUF->tcpoffset = 5 << 4;
|
---|
1240 |
|
---|
1241 | /* Flip the seqno and ackno fields in the TCP header. */
|
---|
1242 | c = BUF->seqno[3];
|
---|
1243 | BUF->seqno[3] = BUF->ackno[3];
|
---|
1244 | BUF->ackno[3] = c;
|
---|
1245 |
|
---|
1246 | c = BUF->seqno[2];
|
---|
1247 | BUF->seqno[2] = BUF->ackno[2];
|
---|
1248 | BUF->ackno[2] = c;
|
---|
1249 |
|
---|
1250 | c = BUF->seqno[1];
|
---|
1251 | BUF->seqno[1] = BUF->ackno[1];
|
---|
1252 | BUF->ackno[1] = c;
|
---|
1253 |
|
---|
1254 | c = BUF->seqno[0];
|
---|
1255 | BUF->seqno[0] = BUF->ackno[0];
|
---|
1256 | BUF->ackno[0] = c;
|
---|
1257 |
|
---|
1258 | /* We also have to increase the sequence number we are
|
---|
1259 | acknowledging. If the least significant byte overflowed, we need
|
---|
1260 | to propagate the carry to the other bytes as well. */
|
---|
1261 | if(++BUF->ackno[3] == 0) {
|
---|
1262 | if(++BUF->ackno[2] == 0) {
|
---|
1263 | if(++BUF->ackno[1] == 0) {
|
---|
1264 | ++BUF->ackno[0];
|
---|
1265 | }
|
---|
1266 | }
|
---|
1267 | }
|
---|
1268 |
|
---|
1269 | /* Swap port numbers. */
|
---|
1270 | tmp16 = BUF->srcport;
|
---|
1271 | BUF->srcport = BUF->destport;
|
---|
1272 | BUF->destport = tmp16;
|
---|
1273 |
|
---|
1274 | /* Swap IP addresses. */
|
---|
1275 | uip_ipaddr_copy(BUF->destipaddr, BUF->srcipaddr);
|
---|
1276 | uip_ipaddr_copy(BUF->srcipaddr, uip_hostaddr);
|
---|
1277 |
|
---|
1278 | /* And send out the RST packet! */
|
---|
1279 | goto tcp_send_noconn;
|
---|
1280 |
|
---|
1281 | /* This label will be jumped to if we matched the incoming packet
|
---|
1282 | with a connection in LISTEN. In that case, we should create a new
|
---|
1283 | connection and send a SYNACK in return. */
|
---|
1284 | found_listen:
|
---|
1285 | /* First we check if there are any connections avaliable. Unused
|
---|
1286 | connections are kept in the same table as used connections, but
|
---|
1287 | unused ones have the tcpstate set to CLOSED. Also, connections in
|
---|
1288 | TIME_WAIT are kept track of and we'll use the oldest one if no
|
---|
1289 | CLOSED connections are found. Thanks to Eddie C. Dost for a very
|
---|
1290 | nice algorithm for the TIME_WAIT search. */
|
---|
1291 | uip_connr = 0;
|
---|
1292 | for(c = 0; c < UIP_CONNS; ++c) {
|
---|
1293 | if(uip_conns[c].tcpstateflags == UIP_CLOSED) {
|
---|
1294 | uip_connr = &uip_conns[c];
|
---|
1295 | break;
|
---|
1296 | }
|
---|
1297 | if(uip_conns[c].tcpstateflags == UIP_TIME_WAIT) {
|
---|
1298 | if(uip_connr == 0 ||
|
---|
1299 | uip_conns[c].timer > uip_connr->timer) {
|
---|
1300 | uip_connr = &uip_conns[c];
|
---|
1301 | }
|
---|
1302 | }
|
---|
1303 | }
|
---|
1304 |
|
---|
1305 | if(uip_connr == 0) {
|
---|
1306 | /* All connections are used already, we drop packet and hope that
|
---|
1307 | the remote end will retransmit the packet at a time when we
|
---|
1308 | have more spare connections. */
|
---|
1309 | UIP_STAT(++uip_stat.tcp.syndrop);
|
---|
1310 | UIP_LOG("tcp: found no unused connections.");
|
---|
1311 | goto drop;
|
---|
1312 | }
|
---|
1313 | uip_conn = uip_connr;
|
---|
1314 |
|
---|
1315 | /* Fill in the necessary fields for the new connection. */
|
---|
1316 | uip_connr->rto = uip_connr->timer = UIP_RTO;
|
---|
1317 | uip_connr->sa = 0;
|
---|
1318 | uip_connr->sv = 4;
|
---|
1319 | uip_connr->nrtx = 0;
|
---|
1320 | uip_connr->lport = BUF->destport;
|
---|
1321 | uip_connr->rport = BUF->srcport;
|
---|
1322 | uip_ipaddr_copy(uip_connr->ripaddr, BUF->srcipaddr);
|
---|
1323 | uip_connr->tcpstateflags = UIP_SYN_RCVD;
|
---|
1324 |
|
---|
1325 | uip_connr->snd_nxt[0] = iss[0];
|
---|
1326 | uip_connr->snd_nxt[1] = iss[1];
|
---|
1327 | uip_connr->snd_nxt[2] = iss[2];
|
---|
1328 | uip_connr->snd_nxt[3] = iss[3];
|
---|
1329 | uip_connr->len = 1;
|
---|
1330 |
|
---|
1331 | /* rcv_nxt should be the seqno from the incoming packet + 1. */
|
---|
1332 | uip_connr->rcv_nxt[3] = BUF->seqno[3];
|
---|
1333 | uip_connr->rcv_nxt[2] = BUF->seqno[2];
|
---|
1334 | uip_connr->rcv_nxt[1] = BUF->seqno[1];
|
---|
1335 | uip_connr->rcv_nxt[0] = BUF->seqno[0];
|
---|
1336 | uip_add_rcv_nxt(1);
|
---|
1337 |
|
---|
1338 | /* Parse the TCP MSS option, if present. */
|
---|
1339 | if((BUF->tcpoffset & 0xf0) > 0x50) {
|
---|
1340 | for(c = 0; c < ((BUF->tcpoffset >> 4) - 5) << 2 ;) {
|
---|
1341 | opt = uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + c];
|
---|
1342 | if(opt == TCP_OPT_END) {
|
---|
1343 | /* End of options. */
|
---|
1344 | break;
|
---|
1345 | } else if(opt == TCP_OPT_NOOP) {
|
---|
1346 | ++c;
|
---|
1347 | /* NOP option. */
|
---|
1348 | } else if(opt == TCP_OPT_MSS &&
|
---|
1349 | uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + c] == TCP_OPT_MSS_LEN) {
|
---|
1350 | /* An MSS option with the right option length. */
|
---|
1351 | tmp16 = ((uint16_t)uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 2 + c] << 8) |
|
---|
1352 | (uint16_t)uip_buf[UIP_IPTCPH_LEN + UIP_LLH_LEN + 3 + c];
|
---|
1353 | uip_connr->initialmss = uip_connr->mss =
|
---|
1354 | tmp16 > UIP_TCP_MSS? UIP_TCP_MSS: tmp16;
|
---|
1355 |
|
---|
1356 | /* And we are done processing options. */
|
---|
1357 | break;
|
---|
1358 | } else {
|
---|
1359 | /* All other options have a length field, so that we easily
|
---|
1360 | can skip past them. */
|
---|
1361 | if(uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + c] == 0) {
|
---|
1362 | /* If the length field is zero, the options are malformed
|
---|
1363 | and we don't process them further. */
|
---|
1364 | break;
|
---|
1365 | }
|
---|
1366 | c += uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + c];
|
---|
1367 | }
|
---|
1368 | }
|
---|
1369 | }
|
---|
1370 |
|
---|
1371 | /* Our response will be a SYNACK. */
|
---|
1372 | #if UIP_ACTIVE_OPEN
|
---|
1373 | tcp_send_synack:
|
---|
1374 | BUF->flags = TCP_ACK;
|
---|
1375 |
|
---|
1376 | tcp_send_syn:
|
---|
1377 | BUF->flags |= TCP_SYN;
|
---|
1378 | #else /* UIP_ACTIVE_OPEN */
|
---|
1379 | tcp_send_synack:
|
---|
1380 | BUF->flags = TCP_SYN | TCP_ACK;
|
---|
1381 | #endif /* UIP_ACTIVE_OPEN */
|
---|
1382 |
|
---|
1383 | /* We send out the TCP Maximum Segment Size option with our
|
---|
1384 | SYNACK. */
|
---|
1385 | BUF->optdata[0] = TCP_OPT_MSS;
|
---|
1386 | BUF->optdata[1] = TCP_OPT_MSS_LEN;
|
---|
1387 | BUF->optdata[2] = (UIP_TCP_MSS) / 256;
|
---|
1388 | BUF->optdata[3] = (UIP_TCP_MSS) & 255;
|
---|
1389 | uip_len = UIP_IPTCPH_LEN + TCP_OPT_MSS_LEN;
|
---|
1390 | BUF->tcpoffset = ((UIP_TCPH_LEN + TCP_OPT_MSS_LEN) / 4) << 4;
|
---|
1391 | goto tcp_send;
|
---|
1392 |
|
---|
1393 | /* This label will be jumped to if we found an active connection. */
|
---|
1394 | found:
|
---|
1395 | uip_conn = uip_connr;
|
---|
1396 | uip_flags = 0;
|
---|
1397 | /* We do a very naive form of TCP reset processing; we just accept
|
---|
1398 | any RST and kill our connection. We should in fact check if the
|
---|
1399 | sequence number of this reset is wihtin our advertised window
|
---|
1400 | before we accept the reset. */
|
---|
1401 | if(BUF->flags & TCP_RST) {
|
---|
1402 | uip_connr->tcpstateflags = UIP_CLOSED;
|
---|
1403 | UIP_LOG("tcp: got reset, aborting connection.");
|
---|
1404 | uip_flags = UIP_ABORT;
|
---|
1405 | UIP_APPCALL();
|
---|
1406 | goto drop;
|
---|
1407 | }
|
---|
1408 | /* Calculated the length of the data, if the application has sent
|
---|
1409 | any data to us. */
|
---|
1410 | c = (BUF->tcpoffset >> 4) << 2;
|
---|
1411 | /* uip_len will contain the length of the actual TCP data. This is
|
---|
1412 | calculated by subtracing the length of the TCP header (in
|
---|
1413 | c) and the length of the IP header (20 bytes). */
|
---|
1414 | uip_len = uip_len - c - UIP_IPH_LEN;
|
---|
1415 |
|
---|
1416 | /* First, check if the sequence number of the incoming packet is
|
---|
1417 | what we're expecting next. If not, we send out an ACK with the
|
---|
1418 | correct numbers in. */
|
---|
1419 | if(!(((uip_connr->tcpstateflags & UIP_TS_MASK) == UIP_SYN_SENT) &&
|
---|
1420 | ((BUF->flags & TCP_CTL) == (TCP_SYN | TCP_ACK)))) {
|
---|
1421 | if((uip_len > 0 || ((BUF->flags & (TCP_SYN | TCP_FIN)) != 0)) &&
|
---|
1422 | (BUF->seqno[0] != uip_connr->rcv_nxt[0] ||
|
---|
1423 | BUF->seqno[1] != uip_connr->rcv_nxt[1] ||
|
---|
1424 | BUF->seqno[2] != uip_connr->rcv_nxt[2] ||
|
---|
1425 | BUF->seqno[3] != uip_connr->rcv_nxt[3])) {
|
---|
1426 | goto tcp_send_ack;
|
---|
1427 | }
|
---|
1428 | }
|
---|
1429 |
|
---|
1430 | /* Next, check if the incoming segment acknowledges any outstanding
|
---|
1431 | data. If so, we update the sequence number, reset the length of
|
---|
1432 | the outstanding data, calculate RTT estimations, and reset the
|
---|
1433 | retransmission timer. */
|
---|
1434 | if((BUF->flags & TCP_ACK) && uip_outstanding(uip_connr)) {
|
---|
1435 | uip_add32(uip_connr->snd_nxt, uip_connr->len);
|
---|
1436 |
|
---|
1437 | if(BUF->ackno[0] == uip_acc32[0] &&
|
---|
1438 | BUF->ackno[1] == uip_acc32[1] &&
|
---|
1439 | BUF->ackno[2] == uip_acc32[2] &&
|
---|
1440 | BUF->ackno[3] == uip_acc32[3]) {
|
---|
1441 | /* Update sequence number. */
|
---|
1442 | uip_connr->snd_nxt[0] = uip_acc32[0];
|
---|
1443 | uip_connr->snd_nxt[1] = uip_acc32[1];
|
---|
1444 | uip_connr->snd_nxt[2] = uip_acc32[2];
|
---|
1445 | uip_connr->snd_nxt[3] = uip_acc32[3];
|
---|
1446 |
|
---|
1447 |
|
---|
1448 | /* Do RTT estimation, unless we have done retransmissions. */
|
---|
1449 | if(uip_connr->nrtx == 0) {
|
---|
1450 | signed char m;
|
---|
1451 | m = uip_connr->rto - uip_connr->timer;
|
---|
1452 | /* This is taken directly from VJs original code in his paper */
|
---|
1453 | m = m - (uip_connr->sa >> 3);
|
---|
1454 | uip_connr->sa += m;
|
---|
1455 | if(m < 0) {
|
---|
1456 | m = -m;
|
---|
1457 | }
|
---|
1458 | m = m - (uip_connr->sv >> 2);
|
---|
1459 | uip_connr->sv += m;
|
---|
1460 | uip_connr->rto = (uip_connr->sa >> 3) + uip_connr->sv;
|
---|
1461 |
|
---|
1462 | }
|
---|
1463 | /* Set the acknowledged flag. */
|
---|
1464 | uip_flags = UIP_ACKDATA;
|
---|
1465 | /* Reset the retransmission timer. */
|
---|
1466 | uip_connr->timer = uip_connr->rto;
|
---|
1467 |
|
---|
1468 | /* Reset length of outstanding data. */
|
---|
1469 | uip_connr->len = 0;
|
---|
1470 | }
|
---|
1471 |
|
---|
1472 | }
|
---|
1473 |
|
---|
1474 | /* Do different things depending on in what state the connection is. */
|
---|
1475 | switch(uip_connr->tcpstateflags & UIP_TS_MASK) {
|
---|
1476 | /* CLOSED and LISTEN are not handled here. CLOSE_WAIT is not
|
---|
1477 | implemented, since we force the application to close when the
|
---|
1478 | peer sends a FIN (hence the application goes directly from
|
---|
1479 | ESTABLISHED to LAST_ACK). */
|
---|
1480 | case UIP_SYN_RCVD:
|
---|
1481 | /* In SYN_RCVD we have sent out a SYNACK in response to a SYN, and
|
---|
1482 | we are waiting for an ACK that acknowledges the data we sent
|
---|
1483 | out the last time. Therefore, we want to have the UIP_ACKDATA
|
---|
1484 | flag set. If so, we enter the ESTABLISHED state. */
|
---|
1485 | if(uip_flags & UIP_ACKDATA) {
|
---|
1486 | uip_connr->tcpstateflags = UIP_ESTABLISHED;
|
---|
1487 | uip_flags = UIP_CONNECTED;
|
---|
1488 | uip_connr->len = 0;
|
---|
1489 | if(uip_len > 0) {
|
---|
1490 | uip_flags |= UIP_NEWDATA;
|
---|
1491 | uip_add_rcv_nxt(uip_len);
|
---|
1492 | }
|
---|
1493 | uip_slen = 0;
|
---|
1494 | UIP_APPCALL();
|
---|
1495 | goto appsend;
|
---|
1496 | }
|
---|
1497 | goto drop;
|
---|
1498 | #if UIP_ACTIVE_OPEN
|
---|
1499 | case UIP_SYN_SENT:
|
---|
1500 | /* In SYN_SENT, we wait for a SYNACK that is sent in response to
|
---|
1501 | our SYN. The rcv_nxt is set to sequence number in the SYNACK
|
---|
1502 | plus one, and we send an ACK. We move into the ESTABLISHED
|
---|
1503 | state. */
|
---|
1504 | if((uip_flags & UIP_ACKDATA) &&
|
---|
1505 | (BUF->flags & TCP_CTL) == (TCP_SYN | TCP_ACK)) {
|
---|
1506 |
|
---|
1507 | /* Parse the TCP MSS option, if present. */
|
---|
1508 | if((BUF->tcpoffset & 0xf0) > 0x50) {
|
---|
1509 | for(c = 0; c < ((BUF->tcpoffset >> 4) - 5) << 2 ;) {
|
---|
1510 | opt = uip_buf[UIP_IPTCPH_LEN + UIP_LLH_LEN + c];
|
---|
1511 | if(opt == TCP_OPT_END) {
|
---|
1512 | /* End of options. */
|
---|
1513 | break;
|
---|
1514 | } else if(opt == TCP_OPT_NOOP) {
|
---|
1515 | ++c;
|
---|
1516 | /* NOP option. */
|
---|
1517 | } else if(opt == TCP_OPT_MSS &&
|
---|
1518 | uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + c] == TCP_OPT_MSS_LEN) {
|
---|
1519 | /* An MSS option with the right option length. */
|
---|
1520 | tmp16 = (uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 2 + c] << 8) |
|
---|
1521 | uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 3 + c];
|
---|
1522 | uip_connr->initialmss =
|
---|
1523 | uip_connr->mss = tmp16 > UIP_TCP_MSS? UIP_TCP_MSS: tmp16;
|
---|
1524 |
|
---|
1525 | /* And we are done processing options. */
|
---|
1526 | break;
|
---|
1527 | } else {
|
---|
1528 | /* All other options have a length field, so that we easily
|
---|
1529 | can skip past them. */
|
---|
1530 | if(uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + c] == 0) {
|
---|
1531 | /* If the length field is zero, the options are malformed
|
---|
1532 | and we don't process them further. */
|
---|
1533 | break;
|
---|
1534 | }
|
---|
1535 | c += uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + c];
|
---|
1536 | }
|
---|
1537 | }
|
---|
1538 | }
|
---|
1539 | uip_connr->tcpstateflags = UIP_ESTABLISHED;
|
---|
1540 | uip_connr->rcv_nxt[0] = BUF->seqno[0];
|
---|
1541 | uip_connr->rcv_nxt[1] = BUF->seqno[1];
|
---|
1542 | uip_connr->rcv_nxt[2] = BUF->seqno[2];
|
---|
1543 | uip_connr->rcv_nxt[3] = BUF->seqno[3];
|
---|
1544 | uip_add_rcv_nxt(1);
|
---|
1545 | uip_flags = UIP_CONNECTED | UIP_NEWDATA;
|
---|
1546 | uip_connr->len = 0;
|
---|
1547 | uip_len = 0;
|
---|
1548 | uip_slen = 0;
|
---|
1549 | UIP_APPCALL();
|
---|
1550 | goto appsend;
|
---|
1551 | }
|
---|
1552 | /* Inform the application that the connection failed */
|
---|
1553 | uip_flags = UIP_ABORT;
|
---|
1554 | UIP_APPCALL();
|
---|
1555 | /* The connection is closed after we send the RST */
|
---|
1556 | uip_conn->tcpstateflags = UIP_CLOSED;
|
---|
1557 | goto reset;
|
---|
1558 | #endif /* UIP_ACTIVE_OPEN */
|
---|
1559 |
|
---|
1560 | case UIP_ESTABLISHED:
|
---|
1561 | /* In the ESTABLISHED state, we call upon the application to feed
|
---|
1562 | data into the uip_buf. If the UIP_ACKDATA flag is set, the
|
---|
1563 | application should put new data into the buffer, otherwise we are
|
---|
1564 | retransmitting an old segment, and the application should put that
|
---|
1565 | data into the buffer.
|
---|
1566 |
|
---|
1567 | If the incoming packet is a FIN, we should close the connection on
|
---|
1568 | this side as well, and we send out a FIN and enter the LAST_ACK
|
---|
1569 | state. We require that there is no outstanding data; otherwise the
|
---|
1570 | sequence numbers will be screwed up. */
|
---|
1571 |
|
---|
1572 | if(BUF->flags & TCP_FIN && !(uip_connr->tcpstateflags & UIP_STOPPED)) {
|
---|
1573 | if(uip_outstanding(uip_connr)) {
|
---|
1574 | goto drop;
|
---|
1575 | }
|
---|
1576 | uip_add_rcv_nxt(1 + uip_len);
|
---|
1577 | uip_flags |= UIP_CLOSE;
|
---|
1578 | if(uip_len > 0) {
|
---|
1579 | uip_flags |= UIP_NEWDATA;
|
---|
1580 | }
|
---|
1581 | UIP_APPCALL();
|
---|
1582 | uip_connr->len = 1;
|
---|
1583 | uip_connr->tcpstateflags = UIP_LAST_ACK;
|
---|
1584 | uip_connr->nrtx = 0;
|
---|
1585 | tcp_send_finack:
|
---|
1586 | BUF->flags = TCP_FIN | TCP_ACK;
|
---|
1587 | goto tcp_send_nodata;
|
---|
1588 | }
|
---|
1589 |
|
---|
1590 | /* Check the URG flag. If this is set, the segment carries urgent
|
---|
1591 | data that we must pass to the application. */
|
---|
1592 | if((BUF->flags & TCP_URG) != 0) {
|
---|
1593 | #if UIP_URGDATA > 0
|
---|
1594 | uip_urglen = (BUF->urgp[0] << 8) | BUF->urgp[1];
|
---|
1595 | if(uip_urglen > uip_len) {
|
---|
1596 | /* There is more urgent data in the next segment to come. */
|
---|
1597 | uip_urglen = uip_len;
|
---|
1598 | }
|
---|
1599 | uip_add_rcv_nxt(uip_urglen);
|
---|
1600 | uip_len -= uip_urglen;
|
---|
1601 | uip_urgdata = uip_appdata;
|
---|
1602 | uip_appdata += uip_urglen;
|
---|
1603 | } else {
|
---|
1604 | uip_urglen = 0;
|
---|
1605 | #else /* UIP_URGDATA > 0 */
|
---|
1606 | uip_appdata = ((char *)uip_appdata) + ((BUF->urgp[0] << 8) | BUF->urgp[1]);
|
---|
1607 | uip_len -= (BUF->urgp[0] << 8) | BUF->urgp[1];
|
---|
1608 | #endif /* UIP_URGDATA > 0 */
|
---|
1609 | }
|
---|
1610 |
|
---|
1611 | /* If uip_len > 0 we have TCP data in the packet, and we flag this
|
---|
1612 | by setting the UIP_NEWDATA flag and update the sequence number
|
---|
1613 | we acknowledge. If the application has stopped the dataflow
|
---|
1614 | using uip_stop(), we must not accept any data packets from the
|
---|
1615 | remote host. */
|
---|
1616 | if(uip_len > 0 && !(uip_connr->tcpstateflags & UIP_STOPPED)) {
|
---|
1617 | uip_flags |= UIP_NEWDATA;
|
---|
1618 | uip_add_rcv_nxt(uip_len);
|
---|
1619 | }
|
---|
1620 |
|
---|
1621 | /* Check if the available buffer space advertised by the other end
|
---|
1622 | is smaller than the initial MSS for this connection. If so, we
|
---|
1623 | set the current MSS to the window size to ensure that the
|
---|
1624 | application does not send more data than the other end can
|
---|
1625 | handle.
|
---|
1626 |
|
---|
1627 | If the remote host advertises a zero window, we set the MSS to
|
---|
1628 | the initial MSS so that the application will send an entire MSS
|
---|
1629 | of data. This data will not be acknowledged by the receiver,
|
---|
1630 | and the application will retransmit it. This is called the
|
---|
1631 | "persistent timer" and uses the retransmission mechanim.
|
---|
1632 | */
|
---|
1633 | tmp16 = ((uint16_t)BUF->wnd[0] << 8) + (uint16_t)BUF->wnd[1];
|
---|
1634 | if(tmp16 > uip_connr->initialmss ||
|
---|
1635 | tmp16 == 0) {
|
---|
1636 | tmp16 = uip_connr->initialmss;
|
---|
1637 | }
|
---|
1638 | uip_connr->mss = tmp16;
|
---|
1639 |
|
---|
1640 | /* If this packet constitutes an ACK for outstanding data (flagged
|
---|
1641 | by the UIP_ACKDATA flag, we should call the application since it
|
---|
1642 | might want to send more data. If the incoming packet had data
|
---|
1643 | from the peer (as flagged by the UIP_NEWDATA flag), the
|
---|
1644 | application must also be notified.
|
---|
1645 |
|
---|
1646 | When the application is called, the global variable uip_len
|
---|
1647 | contains the length of the incoming data. The application can
|
---|
1648 | access the incoming data through the global pointer
|
---|
1649 | uip_appdata, which usually points UIP_IPTCPH_LEN + UIP_LLH_LEN
|
---|
1650 | bytes into the uip_buf array.
|
---|
1651 |
|
---|
1652 | If the application wishes to send any data, this data should be
|
---|
1653 | put into the uip_appdata and the length of the data should be
|
---|
1654 | put into uip_len. If the application don't have any data to
|
---|
1655 | send, uip_len must be set to 0. */
|
---|
1656 | if(uip_flags & (UIP_NEWDATA | UIP_ACKDATA)) {
|
---|
1657 | uip_slen = 0;
|
---|
1658 | UIP_APPCALL();
|
---|
1659 |
|
---|
1660 | appsend:
|
---|
1661 |
|
---|
1662 | if(uip_flags & UIP_ABORT) {
|
---|
1663 | uip_slen = 0;
|
---|
1664 | uip_connr->tcpstateflags = UIP_CLOSED;
|
---|
1665 | BUF->flags = TCP_RST | TCP_ACK;
|
---|
1666 | goto tcp_send_nodata;
|
---|
1667 | }
|
---|
1668 |
|
---|
1669 | if(uip_flags & UIP_CLOSE) {
|
---|
1670 | uip_slen = 0;
|
---|
1671 | uip_connr->len = 1;
|
---|
1672 | uip_connr->tcpstateflags = UIP_FIN_WAIT_1;
|
---|
1673 | uip_connr->nrtx = 0;
|
---|
1674 | BUF->flags = TCP_FIN | TCP_ACK;
|
---|
1675 | goto tcp_send_nodata;
|
---|
1676 | }
|
---|
1677 |
|
---|
1678 | /* If uip_slen > 0, the application has data to be sent. */
|
---|
1679 | if(uip_slen > 0) {
|
---|
1680 |
|
---|
1681 | /* If the connection has acknowledged data, the contents of
|
---|
1682 | the ->len variable should be discarded. */
|
---|
1683 | if((uip_flags & UIP_ACKDATA) != 0) {
|
---|
1684 | uip_connr->len = 0;
|
---|
1685 | }
|
---|
1686 |
|
---|
1687 | /* If the ->len variable is non-zero the connection has
|
---|
1688 | already data in transit and cannot send anymore right
|
---|
1689 | now. */
|
---|
1690 | if(uip_connr->len == 0) {
|
---|
1691 |
|
---|
1692 | /* The application cannot send more than what is allowed by
|
---|
1693 | the mss (the minumum of the MSS and the available
|
---|
1694 | window). */
|
---|
1695 | if(uip_slen > uip_connr->mss) {
|
---|
1696 | uip_slen = uip_connr->mss;
|
---|
1697 | }
|
---|
1698 |
|
---|
1699 | /* Remember how much data we send out now so that we know
|
---|
1700 | when everything has been acknowledged. */
|
---|
1701 | uip_connr->len = uip_slen;
|
---|
1702 | } else {
|
---|
1703 |
|
---|
1704 | /* If the application already had unacknowledged data, we
|
---|
1705 | make sure that the application does not send (i.e.,
|
---|
1706 | retransmit) out more than it previously sent out. */
|
---|
1707 | uip_slen = uip_connr->len;
|
---|
1708 | }
|
---|
1709 | }
|
---|
1710 | uip_connr->nrtx = 0;
|
---|
1711 | apprexmit:
|
---|
1712 | uip_appdata = uip_sappdata;
|
---|
1713 |
|
---|
1714 | /* If the application has data to be sent, or if the incoming
|
---|
1715 | packet had new data in it, we must send out a packet. */
|
---|
1716 | if(uip_slen > 0 && uip_connr->len > 0) {
|
---|
1717 | /* Add the length of the IP and TCP headers. */
|
---|
1718 | uip_len = uip_connr->len + UIP_TCPIP_HLEN;
|
---|
1719 | /* We always set the ACK flag in response packets. */
|
---|
1720 | BUF->flags = TCP_ACK | TCP_PSH;
|
---|
1721 | /* Send the packet. */
|
---|
1722 | goto tcp_send_noopts;
|
---|
1723 | }
|
---|
1724 | /* If there is no data to send, just send out a pure ACK if
|
---|
1725 | there is newdata. */
|
---|
1726 | if(uip_flags & UIP_NEWDATA) {
|
---|
1727 | uip_len = UIP_TCPIP_HLEN;
|
---|
1728 | BUF->flags = TCP_ACK;
|
---|
1729 | goto tcp_send_noopts;
|
---|
1730 | }
|
---|
1731 | }
|
---|
1732 | goto drop;
|
---|
1733 | case UIP_LAST_ACK:
|
---|
1734 | /* We can close this connection if the peer has acknowledged our
|
---|
1735 | FIN. This is indicated by the UIP_ACKDATA flag. */
|
---|
1736 | if(uip_flags & UIP_ACKDATA) {
|
---|
1737 | uip_connr->tcpstateflags = UIP_CLOSED;
|
---|
1738 | uip_flags = UIP_CLOSE;
|
---|
1739 | UIP_APPCALL();
|
---|
1740 | }
|
---|
1741 | break;
|
---|
1742 |
|
---|
1743 | case UIP_FIN_WAIT_1:
|
---|
1744 | /* The application has closed the connection, but the remote host
|
---|
1745 | hasn't closed its end yet. Thus we do nothing but wait for a
|
---|
1746 | FIN from the other side. */
|
---|
1747 | if(uip_len > 0) {
|
---|
1748 | uip_add_rcv_nxt(uip_len);
|
---|
1749 | }
|
---|
1750 | if(BUF->flags & TCP_FIN) {
|
---|
1751 | if(uip_flags & UIP_ACKDATA) {
|
---|
1752 | uip_connr->tcpstateflags = UIP_TIME_WAIT;
|
---|
1753 | uip_connr->timer = 0;
|
---|
1754 | uip_connr->len = 0;
|
---|
1755 | } else {
|
---|
1756 | uip_connr->tcpstateflags = UIP_CLOSING;
|
---|
1757 | }
|
---|
1758 | uip_add_rcv_nxt(1);
|
---|
1759 | uip_flags = UIP_CLOSE;
|
---|
1760 | UIP_APPCALL();
|
---|
1761 | goto tcp_send_ack;
|
---|
1762 | } else if(uip_flags & UIP_ACKDATA) {
|
---|
1763 | uip_connr->tcpstateflags = UIP_FIN_WAIT_2;
|
---|
1764 | uip_connr->len = 0;
|
---|
1765 | goto drop;
|
---|
1766 | }
|
---|
1767 | if(uip_len > 0) {
|
---|
1768 | goto tcp_send_ack;
|
---|
1769 | }
|
---|
1770 | goto drop;
|
---|
1771 |
|
---|
1772 | case UIP_FIN_WAIT_2:
|
---|
1773 | if(uip_len > 0) {
|
---|
1774 | uip_add_rcv_nxt(uip_len);
|
---|
1775 | }
|
---|
1776 | if(BUF->flags & TCP_FIN) {
|
---|
1777 | uip_connr->tcpstateflags = UIP_TIME_WAIT;
|
---|
1778 | uip_connr->timer = 0;
|
---|
1779 | uip_add_rcv_nxt(1);
|
---|
1780 | uip_flags = UIP_CLOSE;
|
---|
1781 | UIP_APPCALL();
|
---|
1782 | goto tcp_send_ack;
|
---|
1783 | }
|
---|
1784 | if(uip_len > 0) {
|
---|
1785 | goto tcp_send_ack;
|
---|
1786 | }
|
---|
1787 | goto drop;
|
---|
1788 |
|
---|
1789 | case UIP_TIME_WAIT:
|
---|
1790 | goto tcp_send_ack;
|
---|
1791 |
|
---|
1792 | case UIP_CLOSING:
|
---|
1793 | if(uip_flags & UIP_ACKDATA) {
|
---|
1794 | uip_connr->tcpstateflags = UIP_TIME_WAIT;
|
---|
1795 | uip_connr->timer = 0;
|
---|
1796 | }
|
---|
1797 | }
|
---|
1798 | goto drop;
|
---|
1799 |
|
---|
1800 |
|
---|
1801 | /* We jump here when we are ready to send the packet, and just want
|
---|
1802 | to set the appropriate TCP sequence numbers in the TCP header. */
|
---|
1803 | tcp_send_ack:
|
---|
1804 | BUF->flags = TCP_ACK;
|
---|
1805 | tcp_send_nodata:
|
---|
1806 | uip_len = UIP_IPTCPH_LEN;
|
---|
1807 | tcp_send_noopts:
|
---|
1808 | BUF->tcpoffset = (UIP_TCPH_LEN / 4) << 4;
|
---|
1809 | tcp_send:
|
---|
1810 | /* We're done with the input processing. We are now ready to send a
|
---|
1811 | reply. Our job is to fill in all the fields of the TCP and IP
|
---|
1812 | headers before calculating the checksum and finally send the
|
---|
1813 | packet. */
|
---|
1814 | BUF->ackno[0] = uip_connr->rcv_nxt[0];
|
---|
1815 | BUF->ackno[1] = uip_connr->rcv_nxt[1];
|
---|
1816 | BUF->ackno[2] = uip_connr->rcv_nxt[2];
|
---|
1817 | BUF->ackno[3] = uip_connr->rcv_nxt[3];
|
---|
1818 |
|
---|
1819 | BUF->seqno[0] = uip_connr->snd_nxt[0];
|
---|
1820 | BUF->seqno[1] = uip_connr->snd_nxt[1];
|
---|
1821 | BUF->seqno[2] = uip_connr->snd_nxt[2];
|
---|
1822 | BUF->seqno[3] = uip_connr->snd_nxt[3];
|
---|
1823 |
|
---|
1824 | BUF->proto = UIP_PROTO_TCP;
|
---|
1825 |
|
---|
1826 | BUF->srcport = uip_connr->lport;
|
---|
1827 | BUF->destport = uip_connr->rport;
|
---|
1828 |
|
---|
1829 | uip_ipaddr_copy(BUF->srcipaddr, uip_hostaddr);
|
---|
1830 | uip_ipaddr_copy(BUF->destipaddr, uip_connr->ripaddr);
|
---|
1831 |
|
---|
1832 | if(uip_connr->tcpstateflags & UIP_STOPPED) {
|
---|
1833 | /* If the connection has issued uip_stop(), we advertise a zero
|
---|
1834 | window so that the remote host will stop sending data. */
|
---|
1835 | BUF->wnd[0] = BUF->wnd[1] = 0;
|
---|
1836 | } else {
|
---|
1837 | BUF->wnd[0] = ((UIP_RECEIVE_WINDOW) >> 8);
|
---|
1838 | BUF->wnd[1] = ((UIP_RECEIVE_WINDOW) & 0xff);
|
---|
1839 | }
|
---|
1840 |
|
---|
1841 | tcp_send_noconn:
|
---|
1842 | BUF->ttl = UIP_TTL;
|
---|
1843 | #if UIP_CONF_IPV6
|
---|
1844 | /* For IPv6, the IP length field does not include the IPv6 IP header
|
---|
1845 | length. */
|
---|
1846 | BUF->len[0] = ((uip_len - UIP_IPH_LEN) >> 8);
|
---|
1847 | BUF->len[1] = ((uip_len - UIP_IPH_LEN) & 0xff);
|
---|
1848 | #else /* UIP_CONF_IPV6 */
|
---|
1849 | BUF->len[0] = (uip_len >> 8);
|
---|
1850 | BUF->len[1] = (uip_len & 0xff);
|
---|
1851 | #endif /* UIP_CONF_IPV6 */
|
---|
1852 |
|
---|
1853 | BUF->urgp[0] = BUF->urgp[1] = 0;
|
---|
1854 |
|
---|
1855 | /* Calculate TCP checksum. */
|
---|
1856 | BUF->tcpchksum = 0;
|
---|
1857 | BUF->tcpchksum = ~(uip_tcpchksum());
|
---|
1858 |
|
---|
1859 | ip_send_nolen:
|
---|
1860 |
|
---|
1861 | #if UIP_CONF_IPV6
|
---|
1862 | BUF->vtc = 0x60;
|
---|
1863 | BUF->tcflow = 0x00;
|
---|
1864 | BUF->flow = 0x00;
|
---|
1865 | #else /* UIP_CONF_IPV6 */
|
---|
1866 | BUF->vhl = 0x45;
|
---|
1867 | BUF->tos = 0;
|
---|
1868 | BUF->ipoffset[0] = BUF->ipoffset[1] = 0;
|
---|
1869 | ++ipid;
|
---|
1870 | BUF->ipid[0] = ipid >> 8;
|
---|
1871 | BUF->ipid[1] = ipid & 0xff;
|
---|
1872 | /* Calculate IP checksum. */
|
---|
1873 | BUF->ipchksum = 0;
|
---|
1874 | BUF->ipchksum = ~(uip_ipchksum());
|
---|
1875 | DEBUG_PRINTF("uip ip_send_nolen: chkecum 0x%04x\n", uip_ipchksum());
|
---|
1876 | #endif /* UIP_CONF_IPV6 */
|
---|
1877 |
|
---|
1878 | UIP_STAT(++uip_stat.tcp.sent);
|
---|
1879 | send:
|
---|
1880 | DEBUG_PRINTF("Sending packet with length %d (%d)\n", uip_len,
|
---|
1881 | (BUF->len[0] << 8) | BUF->len[1]);
|
---|
1882 |
|
---|
1883 | UIP_STAT(++uip_stat.ip.sent);
|
---|
1884 | /* Return and let the caller do the actual transmission. */
|
---|
1885 | uip_flags = 0;
|
---|
1886 | return;
|
---|
1887 | drop:
|
---|
1888 | uip_len = 0;
|
---|
1889 | uip_flags = 0;
|
---|
1890 | return;
|
---|
1891 | }
|
---|
1892 | /*---------------------------------------------------------------------------*/
|
---|
1893 | uint16_t
|
---|
1894 | htons(uint16_t val)
|
---|
1895 | {
|
---|
1896 | return HTONS(val);
|
---|
1897 | }
|
---|
1898 | /*---------------------------------------------------------------------------*/
|
---|
1899 | void
|
---|
1900 | uip_send(const void *data, int len)
|
---|
1901 | {
|
---|
1902 | if(len > 0) {
|
---|
1903 | uip_slen = len;
|
---|
1904 | if(data != uip_sappdata) {
|
---|
1905 | memcpy(uip_sappdata, (data), uip_slen);
|
---|
1906 | }
|
---|
1907 | }
|
---|
1908 | }
|
---|
1909 | /** @} */
|
---|