1 | /**
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2 | * @file
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3 | * This is the IPv4 layer implementation for incoming and outgoing IP traffic.
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4 | *
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5 | * @see ip_frag.c
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6 | *
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7 | */
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8 |
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9 | /*
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10 | * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
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11 | * All rights reserved.
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12 | *
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13 | * Redistribution and use in source and binary forms, with or without modification,
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14 | * are permitted provided that the following conditions are met:
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15 | *
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16 | * 1. Redistributions of source code must retain the above copyright notice,
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17 | * this list of conditions and the following disclaimer.
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18 | * 2. Redistributions in binary form must reproduce the above copyright notice,
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19 | * this list of conditions and the following disclaimer in the documentation
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20 | * and/or other materials provided with the distribution.
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21 | * 3. The name of the author may not be used to endorse or promote products
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22 | * derived from this software without specific prior written permission.
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23 | *
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24 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
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25 | * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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26 | * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
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27 | * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
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28 | * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
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29 | * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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30 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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31 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
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32 | * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
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33 | * OF SUCH DAMAGE.
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34 | *
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35 | * This file is part of the lwIP TCP/IP stack.
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36 | *
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37 | * Author: Adam Dunkels <adam@sics.se>
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38 | *
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39 | */
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40 |
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41 | #include "lwip/opt.h"
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42 |
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43 | #if LWIP_IPV4
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44 |
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45 | #include "lwip/ip.h"
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46 | #include "lwip/def.h"
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47 | #include "lwip/mem.h"
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48 | #include "lwip/ip4_frag.h"
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49 | #include "lwip/inet_chksum.h"
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50 | #include "lwip/netif.h"
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51 | #include "lwip/icmp.h"
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52 | #include "lwip/igmp.h"
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53 | #include "lwip/priv/raw_priv.h"
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54 | #include "lwip/udp.h"
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55 | #include "lwip/priv/tcp_priv.h"
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56 | #include "lwip/autoip.h"
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57 | #include "lwip/stats.h"
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58 | #include "lwip/prot/iana.h"
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59 |
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60 | #include <string.h>
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61 |
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62 | #ifdef LWIP_HOOK_FILENAME
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63 | #include LWIP_HOOK_FILENAME
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64 | #endif
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65 |
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66 | /** Set this to 0 in the rare case of wanting to call an extra function to
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67 | * generate the IP checksum (in contrast to calculating it on-the-fly). */
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68 | #ifndef LWIP_INLINE_IP_CHKSUM
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69 | #if LWIP_CHECKSUM_CTRL_PER_NETIF
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70 | #define LWIP_INLINE_IP_CHKSUM 0
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71 | #else /* LWIP_CHECKSUM_CTRL_PER_NETIF */
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72 | #define LWIP_INLINE_IP_CHKSUM 1
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73 | #endif /* LWIP_CHECKSUM_CTRL_PER_NETIF */
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74 | #endif
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75 |
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76 | #if LWIP_INLINE_IP_CHKSUM && CHECKSUM_GEN_IP
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77 | #define CHECKSUM_GEN_IP_INLINE 1
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78 | #else
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79 | #define CHECKSUM_GEN_IP_INLINE 0
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80 | #endif
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81 |
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82 | #if LWIP_DHCP || defined(LWIP_IP_ACCEPT_UDP_PORT)
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83 | #define IP_ACCEPT_LINK_LAYER_ADDRESSING 1
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84 |
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85 | /** Some defines for DHCP to let link-layer-addressed packets through while the
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86 | * netif is down.
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87 | * To use this in your own application/protocol, define LWIP_IP_ACCEPT_UDP_PORT(port)
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88 | * to return 1 if the port is accepted and 0 if the port is not accepted.
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89 | */
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90 | #if LWIP_DHCP && defined(LWIP_IP_ACCEPT_UDP_PORT)
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91 | /* accept DHCP client port and custom port */
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92 | #define IP_ACCEPT_LINK_LAYER_ADDRESSED_PORT(port) (((port) == PP_NTOHS(LWIP_IANA_PORT_DHCP_CLIENT)) \
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93 | || (LWIP_IP_ACCEPT_UDP_PORT(port)))
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94 | #elif defined(LWIP_IP_ACCEPT_UDP_PORT) /* LWIP_DHCP && defined(LWIP_IP_ACCEPT_UDP_PORT) */
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95 | /* accept custom port only */
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96 | #define IP_ACCEPT_LINK_LAYER_ADDRESSED_PORT(port) (LWIP_IP_ACCEPT_UDP_PORT(port))
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97 | #else /* LWIP_DHCP && defined(LWIP_IP_ACCEPT_UDP_PORT) */
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98 | /* accept DHCP client port only */
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99 | #define IP_ACCEPT_LINK_LAYER_ADDRESSED_PORT(port) ((port) == PP_NTOHS(LWIP_IANA_PORT_DHCP_CLIENT))
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100 | #endif /* LWIP_DHCP && defined(LWIP_IP_ACCEPT_UDP_PORT) */
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101 |
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102 | #else /* LWIP_DHCP */
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103 | #define IP_ACCEPT_LINK_LAYER_ADDRESSING 0
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104 | #endif /* LWIP_DHCP */
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105 |
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106 | /** The IP header ID of the next outgoing IP packet */
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107 | static u16_t ip_id;
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108 |
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109 | #if LWIP_MULTICAST_TX_OPTIONS
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110 | /** The default netif used for multicast */
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111 | static struct netif *ip4_default_multicast_netif;
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112 |
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113 | /**
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114 | * @ingroup ip4
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115 | * Set a default netif for IPv4 multicast. */
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116 | void
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117 | ip4_set_default_multicast_netif(struct netif *default_multicast_netif)
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118 | {
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119 | ip4_default_multicast_netif = default_multicast_netif;
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120 | }
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121 | #endif /* LWIP_MULTICAST_TX_OPTIONS */
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122 |
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123 | #ifdef LWIP_HOOK_IP4_ROUTE_SRC
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124 | /**
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125 | * Source based IPv4 routing must be fully implemented in
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126 | * LWIP_HOOK_IP4_ROUTE_SRC(). This function only provides the parameters.
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127 | */
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128 | struct netif *
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129 | ip4_route_src(const ip4_addr_t *src, const ip4_addr_t *dest)
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130 | {
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131 | if (src != NULL) {
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132 | /* when src==NULL, the hook is called from ip4_route(dest) */
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133 | struct netif *netif = LWIP_HOOK_IP4_ROUTE_SRC(src, dest);
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134 | if (netif != NULL) {
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135 | return netif;
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136 | }
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137 | }
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138 | return ip4_route(dest);
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139 | }
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140 | #endif /* LWIP_HOOK_IP4_ROUTE_SRC */
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141 |
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142 | /**
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143 | * Finds the appropriate network interface for a given IP address. It
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144 | * searches the list of network interfaces linearly. A match is found
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145 | * if the masked IP address of the network interface equals the masked
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146 | * IP address given to the function.
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147 | *
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148 | * @param dest the destination IP address for which to find the route
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149 | * @return the netif on which to send to reach dest
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150 | */
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151 | struct netif *
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152 | ip4_route(const ip4_addr_t *dest)
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153 | {
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154 | #if !LWIP_SINGLE_NETIF
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155 | struct netif *netif;
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156 |
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157 | LWIP_ASSERT_CORE_LOCKED();
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158 |
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159 | #if LWIP_MULTICAST_TX_OPTIONS
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160 | /* Use administratively selected interface for multicast by default */
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161 | if (ip4_addr_ismulticast(dest) && ip4_default_multicast_netif) {
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162 | return ip4_default_multicast_netif;
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163 | }
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164 | #endif /* LWIP_MULTICAST_TX_OPTIONS */
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165 |
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166 | /* bug #54569: in case LWIP_SINGLE_NETIF=1 and LWIP_DEBUGF() disabled, the following loop is optimized away */
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167 | LWIP_UNUSED_ARG(dest);
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168 |
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169 | /* iterate through netifs */
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170 | NETIF_FOREACH(netif) {
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171 | /* is the netif up, does it have a link and a valid address? */
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172 | if (netif_is_up(netif) && netif_is_link_up(netif) && !ip4_addr_isany_val(*netif_ip4_addr(netif))) {
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173 | /* network mask matches? */
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174 | if (ip4_addr_netcmp(dest, netif_ip4_addr(netif), netif_ip4_netmask(netif))) {
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175 | /* return netif on which to forward IP packet */
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176 | return netif;
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177 | }
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178 | /* gateway matches on a non broadcast interface? (i.e. peer in a point to point interface) */
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179 | if (((netif->flags & NETIF_FLAG_BROADCAST) == 0) && ip4_addr_cmp(dest, netif_ip4_gw(netif))) {
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180 | /* return netif on which to forward IP packet */
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181 | return netif;
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182 | }
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183 | }
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184 | }
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185 |
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186 | #if LWIP_NETIF_LOOPBACK && !LWIP_HAVE_LOOPIF
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187 | /* loopif is disabled, looopback traffic is passed through any netif */
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188 | if (ip4_addr_isloopback(dest)) {
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189 | /* don't check for link on loopback traffic */
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190 | if (netif_default != NULL && netif_is_up(netif_default)) {
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191 | return netif_default;
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192 | }
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193 | /* default netif is not up, just use any netif for loopback traffic */
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194 | NETIF_FOREACH(netif) {
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195 | if (netif_is_up(netif)) {
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196 | return netif;
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197 | }
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198 | }
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199 | return NULL;
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200 | }
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201 | #endif /* LWIP_NETIF_LOOPBACK && !LWIP_HAVE_LOOPIF */
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202 |
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203 | #ifdef LWIP_HOOK_IP4_ROUTE_SRC
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204 | netif = LWIP_HOOK_IP4_ROUTE_SRC(NULL, dest);
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205 | if (netif != NULL) {
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206 | return netif;
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207 | }
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208 | #elif defined(LWIP_HOOK_IP4_ROUTE)
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209 | netif = LWIP_HOOK_IP4_ROUTE(dest);
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210 | if (netif != NULL) {
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211 | return netif;
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212 | }
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213 | #endif
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214 | #endif /* !LWIP_SINGLE_NETIF */
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215 |
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216 | if ((netif_default == NULL) || !netif_is_up(netif_default) || !netif_is_link_up(netif_default) ||
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217 | ip4_addr_isany_val(*netif_ip4_addr(netif_default)) || ip4_addr_isloopback(dest)) {
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218 | /* No matching netif found and default netif is not usable.
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219 | If this is not good enough for you, use LWIP_HOOK_IP4_ROUTE() */
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220 | LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("ip4_route: No route to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
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221 | ip4_addr1_16(dest), ip4_addr2_16(dest), ip4_addr3_16(dest), ip4_addr4_16(dest)));
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222 | IP_STATS_INC(ip.rterr);
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223 | MIB2_STATS_INC(mib2.ipoutnoroutes);
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224 | return NULL;
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225 | }
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226 |
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227 | return netif_default;
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228 | }
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229 |
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230 | #if IP_FORWARD
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231 | /**
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232 | * Determine whether an IP address is in a reserved set of addresses
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233 | * that may not be forwarded, or whether datagrams to that destination
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234 | * may be forwarded.
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235 | * @param p the packet to forward
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236 | * @return 1: can forward 0: discard
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237 | */
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238 | static int
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239 | ip4_canforward(struct pbuf *p)
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240 | {
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241 | u32_t addr = lwip_htonl(ip4_addr_get_u32(ip4_current_dest_addr()));
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242 |
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243 | #ifdef LWIP_HOOK_IP4_CANFORWARD
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244 | int ret = LWIP_HOOK_IP4_CANFORWARD(p, addr);
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245 | if (ret >= 0) {
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246 | return ret;
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247 | }
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248 | #endif /* LWIP_HOOK_IP4_CANFORWARD */
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249 |
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250 | if (p->flags & PBUF_FLAG_LLBCAST) {
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251 | /* don't route link-layer broadcasts */
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252 | return 0;
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253 | }
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254 | if ((p->flags & PBUF_FLAG_LLMCAST) || IP_MULTICAST(addr)) {
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255 | /* don't route link-layer multicasts (use LWIP_HOOK_IP4_CANFORWARD instead) */
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256 | return 0;
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257 | }
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258 | if (IP_EXPERIMENTAL(addr)) {
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259 | return 0;
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260 | }
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261 | if (IP_CLASSA(addr)) {
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262 | u32_t net = addr & IP_CLASSA_NET;
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263 | if ((net == 0) || (net == ((u32_t)IP_LOOPBACKNET << IP_CLASSA_NSHIFT))) {
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264 | /* don't route loopback packets */
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265 | return 0;
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266 | }
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267 | }
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268 | return 1;
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269 | }
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270 |
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271 | /**
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272 | * Forwards an IP packet. It finds an appropriate route for the
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273 | * packet, decrements the TTL value of the packet, adjusts the
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274 | * checksum and outputs the packet on the appropriate interface.
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275 | *
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276 | * @param p the packet to forward (p->payload points to IP header)
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277 | * @param iphdr the IP header of the input packet
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278 | * @param inp the netif on which this packet was received
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279 | */
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280 | static void
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281 | ip4_forward(struct pbuf *p, struct ip_hdr *iphdr, struct netif *inp)
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282 | {
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283 | struct netif *netif;
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284 |
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285 | PERF_START;
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286 | LWIP_UNUSED_ARG(inp);
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287 |
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288 | if (!ip4_canforward(p)) {
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289 | goto return_noroute;
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290 | }
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291 |
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292 | /* RFC3927 2.7: do not forward link-local addresses */
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293 | if (ip4_addr_islinklocal(ip4_current_dest_addr())) {
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294 | LWIP_DEBUGF(IP_DEBUG, ("ip4_forward: not forwarding LLA %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
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295 | ip4_addr1_16(ip4_current_dest_addr()), ip4_addr2_16(ip4_current_dest_addr()),
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296 | ip4_addr3_16(ip4_current_dest_addr()), ip4_addr4_16(ip4_current_dest_addr())));
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297 | goto return_noroute;
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298 | }
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299 |
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300 | /* Find network interface where to forward this IP packet to. */
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301 | netif = ip4_route_src(ip4_current_src_addr(), ip4_current_dest_addr());
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302 | if (netif == NULL) {
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303 | LWIP_DEBUGF(IP_DEBUG, ("ip4_forward: no forwarding route for %"U16_F".%"U16_F".%"U16_F".%"U16_F" found\n",
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304 | ip4_addr1_16(ip4_current_dest_addr()), ip4_addr2_16(ip4_current_dest_addr()),
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305 | ip4_addr3_16(ip4_current_dest_addr()), ip4_addr4_16(ip4_current_dest_addr())));
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306 | /* @todo: send ICMP_DUR_NET? */
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307 | goto return_noroute;
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308 | }
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309 | #if !IP_FORWARD_ALLOW_TX_ON_RX_NETIF
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310 | /* Do not forward packets onto the same network interface on which
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311 | * they arrived. */
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312 | if (netif == inp) {
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313 | LWIP_DEBUGF(IP_DEBUG, ("ip4_forward: not bouncing packets back on incoming interface.\n"));
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314 | goto return_noroute;
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315 | }
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316 | #endif /* IP_FORWARD_ALLOW_TX_ON_RX_NETIF */
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317 |
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318 | /* decrement TTL */
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319 | IPH_TTL_SET(iphdr, IPH_TTL(iphdr) - 1);
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320 | /* send ICMP if TTL == 0 */
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321 | if (IPH_TTL(iphdr) == 0) {
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322 | MIB2_STATS_INC(mib2.ipinhdrerrors);
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323 | #if LWIP_ICMP
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324 | /* Don't send ICMP messages in response to ICMP messages */
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325 | if (IPH_PROTO(iphdr) != IP_PROTO_ICMP) {
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326 | icmp_time_exceeded(p, ICMP_TE_TTL);
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327 | }
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328 | #endif /* LWIP_ICMP */
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329 | return;
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330 | }
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331 |
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332 | /* Incrementally update the IP checksum. */
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333 | if (IPH_CHKSUM(iphdr) >= PP_HTONS(0xffffU - 0x100)) {
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334 | IPH_CHKSUM_SET(iphdr, (u16_t)(IPH_CHKSUM(iphdr) + PP_HTONS(0x100) + 1));
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335 | } else {
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336 | IPH_CHKSUM_SET(iphdr, (u16_t)(IPH_CHKSUM(iphdr) + PP_HTONS(0x100)));
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337 | }
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338 |
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339 | LWIP_DEBUGF(IP_DEBUG, ("ip4_forward: forwarding packet to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
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340 | ip4_addr1_16(ip4_current_dest_addr()), ip4_addr2_16(ip4_current_dest_addr()),
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341 | ip4_addr3_16(ip4_current_dest_addr()), ip4_addr4_16(ip4_current_dest_addr())));
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342 |
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343 | IP_STATS_INC(ip.fw);
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344 | MIB2_STATS_INC(mib2.ipforwdatagrams);
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345 | IP_STATS_INC(ip.xmit);
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346 |
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347 | PERF_STOP("ip4_forward");
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348 | /* don't fragment if interface has mtu set to 0 [loopif] */
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349 | if (netif->mtu && (p->tot_len > netif->mtu)) {
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350 | if ((IPH_OFFSET(iphdr) & PP_NTOHS(IP_DF)) == 0) {
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351 | #if IP_FRAG
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352 | ip4_frag(p, netif, ip4_current_dest_addr());
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353 | #else /* IP_FRAG */
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354 | /* @todo: send ICMP Destination Unreachable code 13 "Communication administratively prohibited"? */
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355 | #endif /* IP_FRAG */
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356 | } else {
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357 | #if LWIP_ICMP
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358 | /* send ICMP Destination Unreachable code 4: "Fragmentation Needed and DF Set" */
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359 | icmp_dest_unreach(p, ICMP_DUR_FRAG);
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360 | #endif /* LWIP_ICMP */
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361 | }
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362 | return;
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363 | }
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364 | /* transmit pbuf on chosen interface */
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365 | netif->output(netif, p, ip4_current_dest_addr());
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366 | return;
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367 | return_noroute:
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368 | MIB2_STATS_INC(mib2.ipoutnoroutes);
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369 | }
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370 | #endif /* IP_FORWARD */
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371 |
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372 | /** Return true if the current input packet should be accepted on this netif */
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373 | static int
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374 | ip4_input_accept(struct netif *netif)
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375 | {
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376 | LWIP_DEBUGF(IP_DEBUG, ("ip_input: iphdr->dest 0x%"X32_F" netif->ip_addr 0x%"X32_F" (0x%"X32_F", 0x%"X32_F", 0x%"X32_F")\n",
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377 | ip4_addr_get_u32(ip4_current_dest_addr()), ip4_addr_get_u32(netif_ip4_addr(netif)),
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378 | ip4_addr_get_u32(ip4_current_dest_addr()) & ip4_addr_get_u32(netif_ip4_netmask(netif)),
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379 | ip4_addr_get_u32(netif_ip4_addr(netif)) & ip4_addr_get_u32(netif_ip4_netmask(netif)),
|
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380 | ip4_addr_get_u32(ip4_current_dest_addr()) & ~ip4_addr_get_u32(netif_ip4_netmask(netif))));
|
---|
381 |
|
---|
382 | /* interface is up and configured? */
|
---|
383 | if ((netif_is_up(netif)) && (!ip4_addr_isany_val(*netif_ip4_addr(netif)))) {
|
---|
384 | /* unicast to this interface address? */
|
---|
385 | if (ip4_addr_cmp(ip4_current_dest_addr(), netif_ip4_addr(netif)) ||
|
---|
386 | /* or broadcast on this interface network address? */
|
---|
387 | ip4_addr_isbroadcast(ip4_current_dest_addr(), netif)
|
---|
388 | #if LWIP_NETIF_LOOPBACK && !LWIP_HAVE_LOOPIF
|
---|
389 | || (ip4_addr_get_u32(ip4_current_dest_addr()) == PP_HTONL(IPADDR_LOOPBACK))
|
---|
390 | #endif /* LWIP_NETIF_LOOPBACK && !LWIP_HAVE_LOOPIF */
|
---|
391 | ) {
|
---|
392 | LWIP_DEBUGF(IP_DEBUG, ("ip4_input: packet accepted on interface %c%c\n",
|
---|
393 | netif->name[0], netif->name[1]));
|
---|
394 | /* accept on this netif */
|
---|
395 | return 1;
|
---|
396 | }
|
---|
397 | #if LWIP_AUTOIP
|
---|
398 | /* connections to link-local addresses must persist after changing
|
---|
399 | the netif's address (RFC3927 ch. 1.9) */
|
---|
400 | if (autoip_accept_packet(netif, ip4_current_dest_addr())) {
|
---|
401 | LWIP_DEBUGF(IP_DEBUG, ("ip4_input: LLA packet accepted on interface %c%c\n",
|
---|
402 | netif->name[0], netif->name[1]));
|
---|
403 | /* accept on this netif */
|
---|
404 | return 1;
|
---|
405 | }
|
---|
406 | #endif /* LWIP_AUTOIP */
|
---|
407 | }
|
---|
408 | return 0;
|
---|
409 | }
|
---|
410 |
|
---|
411 | /**
|
---|
412 | * This function is called by the network interface device driver when
|
---|
413 | * an IP packet is received. The function does the basic checks of the
|
---|
414 | * IP header such as packet size being at least larger than the header
|
---|
415 | * size etc. If the packet was not destined for us, the packet is
|
---|
416 | * forwarded (using ip_forward). The IP checksum is always checked.
|
---|
417 | *
|
---|
418 | * Finally, the packet is sent to the upper layer protocol input function.
|
---|
419 | *
|
---|
420 | * @param p the received IP packet (p->payload points to IP header)
|
---|
421 | * @param inp the netif on which this packet was received
|
---|
422 | * @return ERR_OK if the packet was processed (could return ERR_* if it wasn't
|
---|
423 | * processed, but currently always returns ERR_OK)
|
---|
424 | */
|
---|
425 | err_t
|
---|
426 | ip4_input(struct pbuf *p, struct netif *inp)
|
---|
427 | {
|
---|
428 | const struct ip_hdr *iphdr;
|
---|
429 | struct netif *netif;
|
---|
430 | u16_t iphdr_hlen;
|
---|
431 | u16_t iphdr_len;
|
---|
432 | #if IP_ACCEPT_LINK_LAYER_ADDRESSING || LWIP_IGMP
|
---|
433 | int check_ip_src = 1;
|
---|
434 | #endif /* IP_ACCEPT_LINK_LAYER_ADDRESSING || LWIP_IGMP */
|
---|
435 | #if LWIP_RAW
|
---|
436 | raw_input_state_t raw_status;
|
---|
437 | #endif /* LWIP_RAW */
|
---|
438 | #if ETHARP_SUPPORT_STATIC_ENTRIES && LWIP_DHCP
|
---|
439 | struct etharp_hdr *hdr = (struct etharp_hdr *)(p->payload - SIZEOF_ETH_HDR);
|
---|
440 | #endif /* ETHARP_SUPPORT_STATIC_ENTRIES */
|
---|
441 |
|
---|
442 | LWIP_ASSERT_CORE_LOCKED();
|
---|
443 |
|
---|
444 | IP_STATS_INC(ip.recv);
|
---|
445 | MIB2_STATS_INC(mib2.ipinreceives);
|
---|
446 |
|
---|
447 | /* identify the IP header */
|
---|
448 | iphdr = (struct ip_hdr *)p->payload;
|
---|
449 | if (IPH_V(iphdr) != 4) {
|
---|
450 | LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_WARNING, ("IP packet dropped due to bad version number %"U16_F"\n", (u16_t)IPH_V(iphdr)));
|
---|
451 | ip4_debug_print(p);
|
---|
452 | pbuf_free(p);
|
---|
453 | IP_STATS_INC(ip.err);
|
---|
454 | IP_STATS_INC(ip.drop);
|
---|
455 | MIB2_STATS_INC(mib2.ipinhdrerrors);
|
---|
456 | return ERR_OK;
|
---|
457 | }
|
---|
458 |
|
---|
459 | #ifdef LWIP_HOOK_IP4_INPUT
|
---|
460 | if (LWIP_HOOK_IP4_INPUT(p, inp)) {
|
---|
461 | /* the packet has been eaten */
|
---|
462 | return ERR_OK;
|
---|
463 | }
|
---|
464 | #endif
|
---|
465 |
|
---|
466 | /* obtain IP header length in bytes */
|
---|
467 | iphdr_hlen = IPH_HL_BYTES(iphdr);
|
---|
468 | /* obtain ip length in bytes */
|
---|
469 | iphdr_len = lwip_ntohs(IPH_LEN(iphdr));
|
---|
470 |
|
---|
471 | /* Trim pbuf. This is especially required for packets < 60 bytes. */
|
---|
472 | if (iphdr_len < p->tot_len) {
|
---|
473 | pbuf_realloc(p, iphdr_len);
|
---|
474 | }
|
---|
475 |
|
---|
476 | /* header length exceeds first pbuf length, or ip length exceeds total pbuf length? */
|
---|
477 | if ((iphdr_hlen > p->len) || (iphdr_len > p->tot_len) || (iphdr_hlen < IP_HLEN)) {
|
---|
478 | if (iphdr_hlen < IP_HLEN) {
|
---|
479 | LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS,
|
---|
480 | ("ip4_input: short IP header (%"U16_F" bytes) received, IP packet dropped\n", iphdr_hlen));
|
---|
481 | }
|
---|
482 | if (iphdr_hlen > p->len) {
|
---|
483 | LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS,
|
---|
484 | ("IP header (len %"U16_F") does not fit in first pbuf (len %"U16_F"), IP packet dropped.\n",
|
---|
485 | iphdr_hlen, p->len));
|
---|
486 | }
|
---|
487 | if (iphdr_len > p->tot_len) {
|
---|
488 | LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS,
|
---|
489 | ("IP (len %"U16_F") is longer than pbuf (len %"U16_F"), IP packet dropped.\n",
|
---|
490 | iphdr_len, p->tot_len));
|
---|
491 | }
|
---|
492 | /* free (drop) packet pbufs */
|
---|
493 | pbuf_free(p);
|
---|
494 | IP_STATS_INC(ip.lenerr);
|
---|
495 | IP_STATS_INC(ip.drop);
|
---|
496 | MIB2_STATS_INC(mib2.ipindiscards);
|
---|
497 | return ERR_OK;
|
---|
498 | }
|
---|
499 |
|
---|
500 | /* verify checksum */
|
---|
501 | #if CHECKSUM_CHECK_IP
|
---|
502 | IF__NETIF_CHECKSUM_ENABLED(inp, NETIF_CHECKSUM_CHECK_IP) {
|
---|
503 | if (inet_chksum(iphdr, iphdr_hlen) != 0) {
|
---|
504 |
|
---|
505 | LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS,
|
---|
506 | ("Checksum (0x%"X16_F") failed, IP packet dropped.\n", inet_chksum(iphdr, iphdr_hlen)));
|
---|
507 | ip4_debug_print(p);
|
---|
508 | pbuf_free(p);
|
---|
509 | IP_STATS_INC(ip.chkerr);
|
---|
510 | IP_STATS_INC(ip.drop);
|
---|
511 | MIB2_STATS_INC(mib2.ipinhdrerrors);
|
---|
512 | return ERR_OK;
|
---|
513 | }
|
---|
514 | }
|
---|
515 | #endif
|
---|
516 |
|
---|
517 | /* copy IP addresses to aligned ip_addr_t */
|
---|
518 | ip_addr_copy_from_ip4(ip_data.current_iphdr_dest, iphdr->dest);
|
---|
519 | ip_addr_copy_from_ip4(ip_data.current_iphdr_src, iphdr->src);
|
---|
520 |
|
---|
521 | /* match packet against an interface, i.e. is this packet for us? */
|
---|
522 | if (ip4_addr_ismulticast(ip4_current_dest_addr())) {
|
---|
523 | #if LWIP_IGMP
|
---|
524 | if ((inp->flags & NETIF_FLAG_IGMP) && (igmp_lookfor_group(inp, ip4_current_dest_addr()))) {
|
---|
525 | /* IGMP snooping switches need 0.0.0.0 to be allowed as source address (RFC 4541) */
|
---|
526 | ip4_addr_t allsystems;
|
---|
527 | IP4_ADDR(&allsystems, 224, 0, 0, 1);
|
---|
528 | if (ip4_addr_cmp(ip4_current_dest_addr(), &allsystems) &&
|
---|
529 | ip4_addr_isany(ip4_current_src_addr())) {
|
---|
530 | check_ip_src = 0;
|
---|
531 | }
|
---|
532 | netif = inp;
|
---|
533 | } else {
|
---|
534 | netif = NULL;
|
---|
535 | }
|
---|
536 | #else /* LWIP_IGMP */
|
---|
537 | if ((netif_is_up(inp)) && (!ip4_addr_isany_val(*netif_ip4_addr(inp)))) {
|
---|
538 | netif = inp;
|
---|
539 | } else {
|
---|
540 | netif = NULL;
|
---|
541 | }
|
---|
542 | #endif /* LWIP_IGMP */
|
---|
543 | } else {
|
---|
544 | /* start trying with inp. if that's not acceptable, start walking the
|
---|
545 | list of configured netifs. */
|
---|
546 | if (ip4_input_accept(inp)) {
|
---|
547 | netif = inp;
|
---|
548 | } else {
|
---|
549 | netif = NULL;
|
---|
550 | #if !LWIP_NETIF_LOOPBACK || LWIP_HAVE_LOOPIF
|
---|
551 | /* Packets sent to the loopback address must not be accepted on an
|
---|
552 | * interface that does not have the loopback address assigned to it,
|
---|
553 | * unless a non-loopback interface is used for loopback traffic. */
|
---|
554 | if (!ip4_addr_isloopback(ip4_current_dest_addr()))
|
---|
555 | #endif /* !LWIP_NETIF_LOOPBACK || LWIP_HAVE_LOOPIF */
|
---|
556 | {
|
---|
557 | #if !LWIP_SINGLE_NETIF
|
---|
558 | NETIF_FOREACH(netif) {
|
---|
559 | if (netif == inp) {
|
---|
560 | /* we checked that before already */
|
---|
561 | continue;
|
---|
562 | }
|
---|
563 | if (ip4_input_accept(netif)) {
|
---|
564 | break;
|
---|
565 | }
|
---|
566 | }
|
---|
567 | #endif /* !LWIP_SINGLE_NETIF */
|
---|
568 | }
|
---|
569 | }
|
---|
570 | }
|
---|
571 |
|
---|
572 | #if IP_ACCEPT_LINK_LAYER_ADDRESSING
|
---|
573 | /* Pass DHCP messages regardless of destination address. DHCP traffic is addressed
|
---|
574 | * using link layer addressing (such as Ethernet MAC) so we must not filter on IP.
|
---|
575 | * According to RFC 1542 section 3.1.1, referred by RFC 2131).
|
---|
576 | *
|
---|
577 | * If you want to accept private broadcast communication while a netif is down,
|
---|
578 | * define LWIP_IP_ACCEPT_UDP_PORT(dst_port), e.g.:
|
---|
579 | *
|
---|
580 | * #define LWIP_IP_ACCEPT_UDP_PORT(dst_port) ((dst_port) == PP_NTOHS(12345))
|
---|
581 | */
|
---|
582 | if (netif == NULL) {
|
---|
583 | /* remote port is DHCP server? */
|
---|
584 | if (IPH_PROTO(iphdr) == IP_PROTO_UDP) {
|
---|
585 | const struct udp_hdr *udphdr = (const struct udp_hdr *)((const u8_t *)iphdr + iphdr_hlen);
|
---|
586 | LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_TRACE, ("ip4_input: UDP packet to DHCP client port %"U16_F"\n",
|
---|
587 | lwip_ntohs(udphdr->dest)));
|
---|
588 | if (IP_ACCEPT_LINK_LAYER_ADDRESSED_PORT(udphdr->dest)) {
|
---|
589 | LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_TRACE, ("ip4_input: DHCP packet accepted.\n"));
|
---|
590 | netif = inp;
|
---|
591 | check_ip_src = 0;
|
---|
592 | }
|
---|
593 | }
|
---|
594 | }
|
---|
595 | #endif /* IP_ACCEPT_LINK_LAYER_ADDRESSING */
|
---|
596 |
|
---|
597 | /* broadcast or multicast packet source address? Compliant with RFC 1122: 3.2.1.3 */
|
---|
598 | #if LWIP_IGMP || IP_ACCEPT_LINK_LAYER_ADDRESSING
|
---|
599 | if (check_ip_src
|
---|
600 | #if IP_ACCEPT_LINK_LAYER_ADDRESSING
|
---|
601 | /* DHCP servers need 0.0.0.0 to be allowed as source address (RFC 1.1.2.2: 3.2.1.3/a) */
|
---|
602 | && !ip4_addr_isany_val(*ip4_current_src_addr())
|
---|
603 | #endif /* IP_ACCEPT_LINK_LAYER_ADDRESSING */
|
---|
604 | )
|
---|
605 | #endif /* LWIP_IGMP || IP_ACCEPT_LINK_LAYER_ADDRESSING */
|
---|
606 | {
|
---|
607 | if ((ip4_addr_isbroadcast(ip4_current_src_addr(), inp)) ||
|
---|
608 | (ip4_addr_ismulticast(ip4_current_src_addr()))) {
|
---|
609 | /* packet source is not valid */
|
---|
610 | LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, ("ip4_input: packet source is not valid.\n"));
|
---|
611 | /* free (drop) packet pbufs */
|
---|
612 | pbuf_free(p);
|
---|
613 | IP_STATS_INC(ip.drop);
|
---|
614 | MIB2_STATS_INC(mib2.ipinaddrerrors);
|
---|
615 | MIB2_STATS_INC(mib2.ipindiscards);
|
---|
616 | return ERR_OK;
|
---|
617 | }
|
---|
618 | }
|
---|
619 |
|
---|
620 | /* packet not for us? */
|
---|
621 | if (netif == NULL) {
|
---|
622 | /* packet not for us, route or discard */
|
---|
623 | LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_TRACE, ("ip4_input: packet not for us.\n"));
|
---|
624 | #if IP_FORWARD
|
---|
625 | /* non-broadcast packet? */
|
---|
626 | if (!ip4_addr_isbroadcast(ip4_current_dest_addr(), inp)) {
|
---|
627 | /* try to forward IP packet on (other) interfaces */
|
---|
628 | ip4_forward(p, (struct ip_hdr *)p->payload, inp);
|
---|
629 | } else
|
---|
630 | #endif /* IP_FORWARD */
|
---|
631 | {
|
---|
632 | IP_STATS_INC(ip.drop);
|
---|
633 | MIB2_STATS_INC(mib2.ipinaddrerrors);
|
---|
634 | MIB2_STATS_INC(mib2.ipindiscards);
|
---|
635 | }
|
---|
636 | pbuf_free(p);
|
---|
637 | return ERR_OK;
|
---|
638 | }
|
---|
639 | /* packet consists of multiple fragments? */
|
---|
640 | if ((IPH_OFFSET(iphdr) & PP_HTONS(IP_OFFMASK | IP_MF)) != 0) {
|
---|
641 | #if IP_REASSEMBLY /* packet fragment reassembly code present? */
|
---|
642 | LWIP_DEBUGF(IP_DEBUG, ("IP packet is a fragment (id=0x%04"X16_F" tot_len=%"U16_F" len=%"U16_F" MF=%"U16_F" offset=%"U16_F"), calling ip4_reass()\n",
|
---|
643 | lwip_ntohs(IPH_ID(iphdr)), p->tot_len, lwip_ntohs(IPH_LEN(iphdr)), (u16_t)!!(IPH_OFFSET(iphdr) & PP_HTONS(IP_MF)), (u16_t)((lwip_ntohs(IPH_OFFSET(iphdr)) & IP_OFFMASK) * 8)));
|
---|
644 | /* reassemble the packet*/
|
---|
645 | p = ip4_reass(p);
|
---|
646 | /* packet not fully reassembled yet? */
|
---|
647 | if (p == NULL) {
|
---|
648 | return ERR_OK;
|
---|
649 | }
|
---|
650 | iphdr = (const struct ip_hdr *)p->payload;
|
---|
651 | #else /* IP_REASSEMBLY == 0, no packet fragment reassembly code present */
|
---|
652 | pbuf_free(p);
|
---|
653 | LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("IP packet dropped since it was fragmented (0x%"X16_F") (while IP_REASSEMBLY == 0).\n",
|
---|
654 | lwip_ntohs(IPH_OFFSET(iphdr))));
|
---|
655 | IP_STATS_INC(ip.opterr);
|
---|
656 | IP_STATS_INC(ip.drop);
|
---|
657 | /* unsupported protocol feature */
|
---|
658 | MIB2_STATS_INC(mib2.ipinunknownprotos);
|
---|
659 | return ERR_OK;
|
---|
660 | #endif /* IP_REASSEMBLY */
|
---|
661 | }
|
---|
662 |
|
---|
663 | #if IP_OPTIONS_ALLOWED == 0 /* no support for IP options in the IP header? */
|
---|
664 |
|
---|
665 | #if LWIP_IGMP
|
---|
666 | /* there is an extra "router alert" option in IGMP messages which we allow for but do not police */
|
---|
667 | if ((iphdr_hlen > IP_HLEN) && (IPH_PROTO(iphdr) != IP_PROTO_IGMP)) {
|
---|
668 | #else
|
---|
669 | if (iphdr_hlen > IP_HLEN) {
|
---|
670 | #endif /* LWIP_IGMP */
|
---|
671 | LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("IP packet dropped since there were IP options (while IP_OPTIONS_ALLOWED == 0).\n"));
|
---|
672 | pbuf_free(p);
|
---|
673 | IP_STATS_INC(ip.opterr);
|
---|
674 | IP_STATS_INC(ip.drop);
|
---|
675 | /* unsupported protocol feature */
|
---|
676 | MIB2_STATS_INC(mib2.ipinunknownprotos);
|
---|
677 | return ERR_OK;
|
---|
678 | }
|
---|
679 | #endif /* IP_OPTIONS_ALLOWED == 0 */
|
---|
680 |
|
---|
681 | /* send to upper layers */
|
---|
682 | LWIP_DEBUGF(IP_DEBUG, ("ip4_input: \n"));
|
---|
683 | ip4_debug_print(p);
|
---|
684 | LWIP_DEBUGF(IP_DEBUG, ("ip4_input: p->len %"U16_F" p->tot_len %"U16_F"\n", p->len, p->tot_len));
|
---|
685 |
|
---|
686 | ip_data.current_netif = netif;
|
---|
687 | ip_data.current_input_netif = inp;
|
---|
688 | ip_data.current_ip4_header = iphdr;
|
---|
689 | ip_data.current_ip_header_tot_len = IPH_HL_BYTES(iphdr);
|
---|
690 |
|
---|
691 | #if LWIP_RAW
|
---|
692 | /* raw input did not eat the packet? */
|
---|
693 | raw_status = raw_input(p, inp);
|
---|
694 | if (raw_status != RAW_INPUT_EATEN)
|
---|
695 | #endif /* LWIP_RAW */
|
---|
696 | {
|
---|
697 | pbuf_remove_header(p, iphdr_hlen); /* Move to payload, no check necessary. */
|
---|
698 |
|
---|
699 | switch (IPH_PROTO(iphdr)) {
|
---|
700 | #if LWIP_UDP
|
---|
701 | case IP_PROTO_UDP:
|
---|
702 | #if LWIP_UDPLITE
|
---|
703 | case IP_PROTO_UDPLITE:
|
---|
704 | #endif /* LWIP_UDPLITE */
|
---|
705 | MIB2_STATS_INC(mib2.ipindelivers);
|
---|
706 | udp_input(p, inp);
|
---|
707 | break;
|
---|
708 | #endif /* LWIP_UDP */
|
---|
709 | #if LWIP_TCP
|
---|
710 | case IP_PROTO_TCP:
|
---|
711 | MIB2_STATS_INC(mib2.ipindelivers);
|
---|
712 | tcp_input(p, inp);
|
---|
713 | break;
|
---|
714 | #endif /* LWIP_TCP */
|
---|
715 | #if LWIP_ICMP
|
---|
716 | case IP_PROTO_ICMP:
|
---|
717 | MIB2_STATS_INC(mib2.ipindelivers);
|
---|
718 | #if ETHARP_SUPPORT_STATIC_ENTRIES && LWIP_DHCP
|
---|
719 | /* FOR PING ERROR WHEN NO ARP PAKCET */
|
---|
720 | etharp_add_static_entry(ip4_current_src_addr(), &(hdr->shwaddr));
|
---|
721 | #endif /* ETHARP_SUPPORT_STATIC_ENTRIES */
|
---|
722 | icmp_input(p, inp);
|
---|
723 | break;
|
---|
724 | #endif /* LWIP_ICMP */
|
---|
725 | #if LWIP_IGMP
|
---|
726 | case IP_PROTO_IGMP:
|
---|
727 | igmp_input(p, inp, ip4_current_dest_addr());
|
---|
728 | break;
|
---|
729 | #endif /* LWIP_IGMP */
|
---|
730 | default:
|
---|
731 | #if LWIP_RAW
|
---|
732 | if (raw_status == RAW_INPUT_DELIVERED) {
|
---|
733 | MIB2_STATS_INC(mib2.ipindelivers);
|
---|
734 | } else
|
---|
735 | #endif /* LWIP_RAW */
|
---|
736 | {
|
---|
737 | #if LWIP_ICMP
|
---|
738 | /* send ICMP destination protocol unreachable unless is was a broadcast */
|
---|
739 | if (!ip4_addr_isbroadcast(ip4_current_dest_addr(), netif) &&
|
---|
740 | !ip4_addr_ismulticast(ip4_current_dest_addr())) {
|
---|
741 | pbuf_header_force(p, (s16_t)iphdr_hlen); /* Move to ip header, no check necessary. */
|
---|
742 | icmp_dest_unreach(p, ICMP_DUR_PROTO);
|
---|
743 | }
|
---|
744 | #endif /* LWIP_ICMP */
|
---|
745 |
|
---|
746 | LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("Unsupported transport protocol %"U16_F"\n", (u16_t)IPH_PROTO(iphdr)));
|
---|
747 |
|
---|
748 | IP_STATS_INC(ip.proterr);
|
---|
749 | IP_STATS_INC(ip.drop);
|
---|
750 | MIB2_STATS_INC(mib2.ipinunknownprotos);
|
---|
751 | }
|
---|
752 | pbuf_free(p);
|
---|
753 | break;
|
---|
754 | }
|
---|
755 | }
|
---|
756 |
|
---|
757 | /* @todo: this is not really necessary... */
|
---|
758 | ip_data.current_netif = NULL;
|
---|
759 | ip_data.current_input_netif = NULL;
|
---|
760 | ip_data.current_ip4_header = NULL;
|
---|
761 | ip_data.current_ip_header_tot_len = 0;
|
---|
762 | ip4_addr_set_any(ip4_current_src_addr());
|
---|
763 | ip4_addr_set_any(ip4_current_dest_addr());
|
---|
764 |
|
---|
765 | return ERR_OK;
|
---|
766 | }
|
---|
767 |
|
---|
768 | /**
|
---|
769 | * Sends an IP packet on a network interface. This function constructs
|
---|
770 | * the IP header and calculates the IP header checksum. If the source
|
---|
771 | * IP address is NULL, the IP address of the outgoing network
|
---|
772 | * interface is filled in as source address.
|
---|
773 | * If the destination IP address is LWIP_IP_HDRINCL, p is assumed to already
|
---|
774 | * include an IP header and p->payload points to it instead of the data.
|
---|
775 | *
|
---|
776 | * @param p the packet to send (p->payload points to the data, e.g. next
|
---|
777 | protocol header; if dest == LWIP_IP_HDRINCL, p already includes an
|
---|
778 | IP header and p->payload points to that IP header)
|
---|
779 | * @param src the source IP address to send from (if src == IP4_ADDR_ANY, the
|
---|
780 | * IP address of the netif used to send is used as source address)
|
---|
781 | * @param dest the destination IP address to send the packet to
|
---|
782 | * @param ttl the TTL value to be set in the IP header
|
---|
783 | * @param tos the TOS value to be set in the IP header
|
---|
784 | * @param proto the PROTOCOL to be set in the IP header
|
---|
785 | * @param netif the netif on which to send this packet
|
---|
786 | * @return ERR_OK if the packet was sent OK
|
---|
787 | * ERR_BUF if p doesn't have enough space for IP/LINK headers
|
---|
788 | * returns errors returned by netif->output
|
---|
789 | *
|
---|
790 | * @note ip_id: RFC791 "some host may be able to simply use
|
---|
791 | * unique identifiers independent of destination"
|
---|
792 | */
|
---|
793 | err_t
|
---|
794 | ip4_output_if(struct pbuf *p, const ip4_addr_t *src, const ip4_addr_t *dest,
|
---|
795 | u8_t ttl, u8_t tos,
|
---|
796 | u8_t proto, struct netif *netif)
|
---|
797 | {
|
---|
798 | #if IP_OPTIONS_SEND
|
---|
799 | return ip4_output_if_opt(p, src, dest, ttl, tos, proto, netif, NULL, 0);
|
---|
800 | }
|
---|
801 |
|
---|
802 | /**
|
---|
803 | * Same as ip_output_if() but with the possibility to include IP options:
|
---|
804 | *
|
---|
805 | * @ param ip_options pointer to the IP options, copied into the IP header
|
---|
806 | * @ param optlen length of ip_options
|
---|
807 | */
|
---|
808 | err_t
|
---|
809 | ip4_output_if_opt(struct pbuf *p, const ip4_addr_t *src, const ip4_addr_t *dest,
|
---|
810 | u8_t ttl, u8_t tos, u8_t proto, struct netif *netif, void *ip_options,
|
---|
811 | u16_t optlen)
|
---|
812 | {
|
---|
813 | #endif /* IP_OPTIONS_SEND */
|
---|
814 | const ip4_addr_t *src_used = src;
|
---|
815 | if (dest != LWIP_IP_HDRINCL) {
|
---|
816 | if (ip4_addr_isany(src)) {
|
---|
817 | src_used = netif_ip4_addr(netif);
|
---|
818 | }
|
---|
819 | }
|
---|
820 |
|
---|
821 | #if IP_OPTIONS_SEND
|
---|
822 | return ip4_output_if_opt_src(p, src_used, dest, ttl, tos, proto, netif,
|
---|
823 | ip_options, optlen);
|
---|
824 | #else /* IP_OPTIONS_SEND */
|
---|
825 | return ip4_output_if_src(p, src_used, dest, ttl, tos, proto, netif);
|
---|
826 | #endif /* IP_OPTIONS_SEND */
|
---|
827 | }
|
---|
828 |
|
---|
829 | /**
|
---|
830 | * Same as ip_output_if() but 'src' address is not replaced by netif address
|
---|
831 | * when it is 'any'.
|
---|
832 | */
|
---|
833 | err_t
|
---|
834 | ip4_output_if_src(struct pbuf *p, const ip4_addr_t *src, const ip4_addr_t *dest,
|
---|
835 | u8_t ttl, u8_t tos,
|
---|
836 | u8_t proto, struct netif *netif)
|
---|
837 | {
|
---|
838 | #if IP_OPTIONS_SEND
|
---|
839 | return ip4_output_if_opt_src(p, src, dest, ttl, tos, proto, netif, NULL, 0);
|
---|
840 | }
|
---|
841 |
|
---|
842 | /**
|
---|
843 | * Same as ip_output_if_opt() but 'src' address is not replaced by netif address
|
---|
844 | * when it is 'any'.
|
---|
845 | */
|
---|
846 | err_t
|
---|
847 | ip4_output_if_opt_src(struct pbuf *p, const ip4_addr_t *src, const ip4_addr_t *dest,
|
---|
848 | u8_t ttl, u8_t tos, u8_t proto, struct netif *netif, void *ip_options,
|
---|
849 | u16_t optlen)
|
---|
850 | {
|
---|
851 | #endif /* IP_OPTIONS_SEND */
|
---|
852 | struct ip_hdr *iphdr;
|
---|
853 | ip4_addr_t dest_addr;
|
---|
854 | #if CHECKSUM_GEN_IP_INLINE
|
---|
855 | u32_t chk_sum = 0;
|
---|
856 | #endif /* CHECKSUM_GEN_IP_INLINE */
|
---|
857 |
|
---|
858 | LWIP_ASSERT_CORE_LOCKED();
|
---|
859 | LWIP_IP_CHECK_PBUF_REF_COUNT_FOR_TX(p);
|
---|
860 |
|
---|
861 | MIB2_STATS_INC(mib2.ipoutrequests);
|
---|
862 |
|
---|
863 | /* Should the IP header be generated or is it already included in p? */
|
---|
864 | if (dest != LWIP_IP_HDRINCL) {
|
---|
865 | u16_t ip_hlen = IP_HLEN;
|
---|
866 | #if IP_OPTIONS_SEND
|
---|
867 | u16_t optlen_aligned = 0;
|
---|
868 | if (optlen != 0) {
|
---|
869 | #if CHECKSUM_GEN_IP_INLINE
|
---|
870 | int i;
|
---|
871 | #endif /* CHECKSUM_GEN_IP_INLINE */
|
---|
872 | if (optlen > (IP_HLEN_MAX - IP_HLEN)) {
|
---|
873 | /* optlen too long */
|
---|
874 | LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("ip4_output_if_opt: optlen too long\n"));
|
---|
875 | IP_STATS_INC(ip.err);
|
---|
876 | MIB2_STATS_INC(mib2.ipoutdiscards);
|
---|
877 | return ERR_VAL;
|
---|
878 | }
|
---|
879 | /* round up to a multiple of 4 */
|
---|
880 | optlen_aligned = (u16_t)((optlen + 3) & ~3);
|
---|
881 | ip_hlen = (u16_t)(ip_hlen + optlen_aligned);
|
---|
882 | /* First write in the IP options */
|
---|
883 | if (pbuf_add_header(p, optlen_aligned)) {
|
---|
884 | LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("ip4_output_if_opt: not enough room for IP options in pbuf\n"));
|
---|
885 | IP_STATS_INC(ip.err);
|
---|
886 | MIB2_STATS_INC(mib2.ipoutdiscards);
|
---|
887 | return ERR_BUF;
|
---|
888 | }
|
---|
889 | MEMCPY(p->payload, ip_options, optlen);
|
---|
890 | if (optlen < optlen_aligned) {
|
---|
891 | /* zero the remaining bytes */
|
---|
892 | memset(((char *)p->payload) + optlen, 0, (size_t)(optlen_aligned - optlen));
|
---|
893 | }
|
---|
894 | #if CHECKSUM_GEN_IP_INLINE
|
---|
895 | for (i = 0; i < optlen_aligned / 2; i++) {
|
---|
896 | chk_sum += ((u16_t *)p->payload)[i];
|
---|
897 | }
|
---|
898 | #endif /* CHECKSUM_GEN_IP_INLINE */
|
---|
899 | }
|
---|
900 | #endif /* IP_OPTIONS_SEND */
|
---|
901 | /* generate IP header */
|
---|
902 | if (pbuf_add_header(p, IP_HLEN)) {
|
---|
903 | LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("ip4_output: not enough room for IP header in pbuf\n"));
|
---|
904 |
|
---|
905 | IP_STATS_INC(ip.err);
|
---|
906 | MIB2_STATS_INC(mib2.ipoutdiscards);
|
---|
907 | return ERR_BUF;
|
---|
908 | }
|
---|
909 |
|
---|
910 | iphdr = (struct ip_hdr *)p->payload;
|
---|
911 | LWIP_ASSERT("check that first pbuf can hold struct ip_hdr",
|
---|
912 | (p->len >= sizeof(struct ip_hdr)));
|
---|
913 |
|
---|
914 | IPH_TTL_SET(iphdr, ttl);
|
---|
915 | IPH_PROTO_SET(iphdr, proto);
|
---|
916 | #if CHECKSUM_GEN_IP_INLINE
|
---|
917 | chk_sum += PP_NTOHS(proto | (ttl << 8));
|
---|
918 | #endif /* CHECKSUM_GEN_IP_INLINE */
|
---|
919 |
|
---|
920 | /* dest cannot be NULL here */
|
---|
921 | ip4_addr_copy(iphdr->dest, *dest);
|
---|
922 | #if CHECKSUM_GEN_IP_INLINE
|
---|
923 | chk_sum += ip4_addr_get_u32(&iphdr->dest) & 0xFFFF;
|
---|
924 | chk_sum += ip4_addr_get_u32(&iphdr->dest) >> 16;
|
---|
925 | #endif /* CHECKSUM_GEN_IP_INLINE */
|
---|
926 |
|
---|
927 | IPH_VHL_SET(iphdr, 4, ip_hlen / 4);
|
---|
928 | IPH_TOS_SET(iphdr, tos);
|
---|
929 | #if CHECKSUM_GEN_IP_INLINE
|
---|
930 | chk_sum += PP_NTOHS(tos | (iphdr->_v_hl << 8));
|
---|
931 | #endif /* CHECKSUM_GEN_IP_INLINE */
|
---|
932 | IPH_LEN_SET(iphdr, lwip_htons(p->tot_len));
|
---|
933 | #if CHECKSUM_GEN_IP_INLINE
|
---|
934 | chk_sum += iphdr->_len;
|
---|
935 | #endif /* CHECKSUM_GEN_IP_INLINE */
|
---|
936 | IPH_OFFSET_SET(iphdr, 0);
|
---|
937 | IPH_ID_SET(iphdr, lwip_htons(ip_id));
|
---|
938 | #if CHECKSUM_GEN_IP_INLINE
|
---|
939 | chk_sum += iphdr->_id;
|
---|
940 | #endif /* CHECKSUM_GEN_IP_INLINE */
|
---|
941 | ++ip_id;
|
---|
942 |
|
---|
943 | if (src == NULL) {
|
---|
944 | ip4_addr_copy(iphdr->src, *IP4_ADDR_ANY4);
|
---|
945 | } else {
|
---|
946 | /* src cannot be NULL here */
|
---|
947 | ip4_addr_copy(iphdr->src, *src);
|
---|
948 | }
|
---|
949 |
|
---|
950 | #if CHECKSUM_GEN_IP_INLINE
|
---|
951 | chk_sum += ip4_addr_get_u32(&iphdr->src) & 0xFFFF;
|
---|
952 | chk_sum += ip4_addr_get_u32(&iphdr->src) >> 16;
|
---|
953 | chk_sum = (chk_sum >> 16) + (chk_sum & 0xFFFF);
|
---|
954 | chk_sum = (chk_sum >> 16) + chk_sum;
|
---|
955 | chk_sum = ~chk_sum;
|
---|
956 | IF__NETIF_CHECKSUM_ENABLED(netif, NETIF_CHECKSUM_GEN_IP) {
|
---|
957 | iphdr->_chksum = (u16_t)chk_sum; /* network order */
|
---|
958 | }
|
---|
959 | #if LWIP_CHECKSUM_CTRL_PER_NETIF
|
---|
960 | else {
|
---|
961 | IPH_CHKSUM_SET(iphdr, 0);
|
---|
962 | }
|
---|
963 | #endif /* LWIP_CHECKSUM_CTRL_PER_NETIF*/
|
---|
964 | #else /* CHECKSUM_GEN_IP_INLINE */
|
---|
965 | IPH_CHKSUM_SET(iphdr, 0);
|
---|
966 | #if CHECKSUM_GEN_IP
|
---|
967 | IF__NETIF_CHECKSUM_ENABLED(netif, NETIF_CHECKSUM_GEN_IP) {
|
---|
968 | IPH_CHKSUM_SET(iphdr, inet_chksum(iphdr, ip_hlen));
|
---|
969 | }
|
---|
970 | #endif /* CHECKSUM_GEN_IP */
|
---|
971 | #endif /* CHECKSUM_GEN_IP_INLINE */
|
---|
972 | } else {
|
---|
973 | /* IP header already included in p */
|
---|
974 | if (p->len < IP_HLEN) {
|
---|
975 | LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("ip4_output: LWIP_IP_HDRINCL but pbuf is too short\n"));
|
---|
976 | IP_STATS_INC(ip.err);
|
---|
977 | MIB2_STATS_INC(mib2.ipoutdiscards);
|
---|
978 | return ERR_BUF;
|
---|
979 | }
|
---|
980 | iphdr = (struct ip_hdr *)p->payload;
|
---|
981 | ip4_addr_copy(dest_addr, iphdr->dest);
|
---|
982 | dest = &dest_addr;
|
---|
983 | }
|
---|
984 |
|
---|
985 | IP_STATS_INC(ip.xmit);
|
---|
986 |
|
---|
987 | LWIP_DEBUGF(IP_DEBUG, ("ip4_output_if: %c%c%"U16_F"\n", netif->name[0], netif->name[1], (u16_t)netif->num));
|
---|
988 | ip4_debug_print(p);
|
---|
989 |
|
---|
990 | #if ENABLE_LOOPBACK
|
---|
991 | if (ip4_addr_cmp(dest, netif_ip4_addr(netif))
|
---|
992 | #if !LWIP_HAVE_LOOPIF
|
---|
993 | || ip4_addr_isloopback(dest)
|
---|
994 | #endif /* !LWIP_HAVE_LOOPIF */
|
---|
995 | ) {
|
---|
996 | /* Packet to self, enqueue it for loopback */
|
---|
997 | LWIP_DEBUGF(IP_DEBUG, ("netif_loop_output()"));
|
---|
998 | return netif_loop_output(netif, p);
|
---|
999 | }
|
---|
1000 | #if LWIP_MULTICAST_TX_OPTIONS
|
---|
1001 | if ((p->flags & PBUF_FLAG_MCASTLOOP) != 0) {
|
---|
1002 | netif_loop_output(netif, p);
|
---|
1003 | }
|
---|
1004 | #endif /* LWIP_MULTICAST_TX_OPTIONS */
|
---|
1005 | #endif /* ENABLE_LOOPBACK */
|
---|
1006 | #if IP_FRAG
|
---|
1007 | /* don't fragment if interface has mtu set to 0 [loopif] */
|
---|
1008 | if (netif->mtu && (p->tot_len > netif->mtu)) {
|
---|
1009 | return ip4_frag(p, netif, dest);
|
---|
1010 | }
|
---|
1011 | #endif /* IP_FRAG */
|
---|
1012 |
|
---|
1013 | LWIP_DEBUGF(IP_DEBUG, ("ip4_output_if: call netif->output()\n"));
|
---|
1014 | return netif->output(netif, p, dest);
|
---|
1015 | }
|
---|
1016 |
|
---|
1017 | /**
|
---|
1018 | * Simple interface to ip_output_if. It finds the outgoing network
|
---|
1019 | * interface and calls upon ip_output_if to do the actual work.
|
---|
1020 | *
|
---|
1021 | * @param p the packet to send (p->payload points to the data, e.g. next
|
---|
1022 | protocol header; if dest == LWIP_IP_HDRINCL, p already includes an
|
---|
1023 | IP header and p->payload points to that IP header)
|
---|
1024 | * @param src the source IP address to send from (if src == IP4_ADDR_ANY, the
|
---|
1025 | * IP address of the netif used to send is used as source address)
|
---|
1026 | * @param dest the destination IP address to send the packet to
|
---|
1027 | * @param ttl the TTL value to be set in the IP header
|
---|
1028 | * @param tos the TOS value to be set in the IP header
|
---|
1029 | * @param proto the PROTOCOL to be set in the IP header
|
---|
1030 | *
|
---|
1031 | * @return ERR_RTE if no route is found
|
---|
1032 | * see ip_output_if() for more return values
|
---|
1033 | */
|
---|
1034 | err_t
|
---|
1035 | ip4_output(struct pbuf *p, const ip4_addr_t *src, const ip4_addr_t *dest,
|
---|
1036 | u8_t ttl, u8_t tos, u8_t proto)
|
---|
1037 | {
|
---|
1038 | struct netif *netif;
|
---|
1039 |
|
---|
1040 | LWIP_IP_CHECK_PBUF_REF_COUNT_FOR_TX(p);
|
---|
1041 |
|
---|
1042 | if ((netif = ip4_route_src(src, dest)) == NULL) {
|
---|
1043 | LWIP_DEBUGF(IP_DEBUG, ("ip4_output: No route to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
|
---|
1044 | ip4_addr1_16(dest), ip4_addr2_16(dest), ip4_addr3_16(dest), ip4_addr4_16(dest)));
|
---|
1045 | IP_STATS_INC(ip.rterr);
|
---|
1046 | return ERR_RTE;
|
---|
1047 | }
|
---|
1048 |
|
---|
1049 | return ip4_output_if(p, src, dest, ttl, tos, proto, netif);
|
---|
1050 | }
|
---|
1051 |
|
---|
1052 | #if LWIP_NETIF_USE_HINTS
|
---|
1053 | /** Like ip_output, but takes and addr_hint pointer that is passed on to netif->addr_hint
|
---|
1054 | * before calling ip_output_if.
|
---|
1055 | *
|
---|
1056 | * @param p the packet to send (p->payload points to the data, e.g. next
|
---|
1057 | protocol header; if dest == LWIP_IP_HDRINCL, p already includes an
|
---|
1058 | IP header and p->payload points to that IP header)
|
---|
1059 | * @param src the source IP address to send from (if src == IP4_ADDR_ANY, the
|
---|
1060 | * IP address of the netif used to send is used as source address)
|
---|
1061 | * @param dest the destination IP address to send the packet to
|
---|
1062 | * @param ttl the TTL value to be set in the IP header
|
---|
1063 | * @param tos the TOS value to be set in the IP header
|
---|
1064 | * @param proto the PROTOCOL to be set in the IP header
|
---|
1065 | * @param netif_hint netif output hint pointer set to netif->hint before
|
---|
1066 | * calling ip_output_if()
|
---|
1067 | *
|
---|
1068 | * @return ERR_RTE if no route is found
|
---|
1069 | * see ip_output_if() for more return values
|
---|
1070 | */
|
---|
1071 | err_t
|
---|
1072 | ip4_output_hinted(struct pbuf *p, const ip4_addr_t *src, const ip4_addr_t *dest,
|
---|
1073 | u8_t ttl, u8_t tos, u8_t proto, struct netif_hint *netif_hint)
|
---|
1074 | {
|
---|
1075 | struct netif *netif;
|
---|
1076 | err_t err;
|
---|
1077 |
|
---|
1078 | LWIP_IP_CHECK_PBUF_REF_COUNT_FOR_TX(p);
|
---|
1079 |
|
---|
1080 | if ((netif = ip4_route_src(src, dest)) == NULL) {
|
---|
1081 | LWIP_DEBUGF(IP_DEBUG, ("ip4_output: No route to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
|
---|
1082 | ip4_addr1_16(dest), ip4_addr2_16(dest), ip4_addr3_16(dest), ip4_addr4_16(dest)));
|
---|
1083 | IP_STATS_INC(ip.rterr);
|
---|
1084 | return ERR_RTE;
|
---|
1085 | }
|
---|
1086 |
|
---|
1087 | NETIF_SET_HINTS(netif, netif_hint);
|
---|
1088 | err = ip4_output_if(p, src, dest, ttl, tos, proto, netif);
|
---|
1089 | NETIF_RESET_HINTS(netif);
|
---|
1090 |
|
---|
1091 | return err;
|
---|
1092 | }
|
---|
1093 | #endif /* LWIP_NETIF_USE_HINTS*/
|
---|
1094 |
|
---|
1095 | #if IP_DEBUG
|
---|
1096 | /* Print an IP header by using LWIP_DEBUGF
|
---|
1097 | * @param p an IP packet, p->payload pointing to the IP header
|
---|
1098 | */
|
---|
1099 | void
|
---|
1100 | ip4_debug_print(struct pbuf *p)
|
---|
1101 | {
|
---|
1102 | struct ip_hdr *iphdr = (struct ip_hdr *)p->payload;
|
---|
1103 |
|
---|
1104 | LWIP_DEBUGF(IP_DEBUG, ("IP header:\n"));
|
---|
1105 | LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
|
---|
1106 | LWIP_DEBUGF(IP_DEBUG, ("|%2"S16_F" |%2"S16_F" | 0x%02"X16_F" | %5"U16_F" | (v, hl, tos, len)\n",
|
---|
1107 | (u16_t)IPH_V(iphdr),
|
---|
1108 | (u16_t)IPH_HL(iphdr),
|
---|
1109 | (u16_t)IPH_TOS(iphdr),
|
---|
1110 | lwip_ntohs(IPH_LEN(iphdr))));
|
---|
1111 | LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
|
---|
1112 | LWIP_DEBUGF(IP_DEBUG, ("| %5"U16_F" |%"U16_F"%"U16_F"%"U16_F"| %4"U16_F" | (id, flags, offset)\n",
|
---|
1113 | lwip_ntohs(IPH_ID(iphdr)),
|
---|
1114 | (u16_t)(lwip_ntohs(IPH_OFFSET(iphdr)) >> 15 & 1),
|
---|
1115 | (u16_t)(lwip_ntohs(IPH_OFFSET(iphdr)) >> 14 & 1),
|
---|
1116 | (u16_t)(lwip_ntohs(IPH_OFFSET(iphdr)) >> 13 & 1),
|
---|
1117 | (u16_t)(lwip_ntohs(IPH_OFFSET(iphdr)) & IP_OFFMASK)));
|
---|
1118 | LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
|
---|
1119 | LWIP_DEBUGF(IP_DEBUG, ("| %3"U16_F" | %3"U16_F" | 0x%04"X16_F" | (ttl, proto, chksum)\n",
|
---|
1120 | (u16_t)IPH_TTL(iphdr),
|
---|
1121 | (u16_t)IPH_PROTO(iphdr),
|
---|
1122 | lwip_ntohs(IPH_CHKSUM(iphdr))));
|
---|
1123 | LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
|
---|
1124 | LWIP_DEBUGF(IP_DEBUG, ("| %3"U16_F" | %3"U16_F" | %3"U16_F" | %3"U16_F" | (src)\n",
|
---|
1125 | ip4_addr1_16_val(iphdr->src),
|
---|
1126 | ip4_addr2_16_val(iphdr->src),
|
---|
1127 | ip4_addr3_16_val(iphdr->src),
|
---|
1128 | ip4_addr4_16_val(iphdr->src)));
|
---|
1129 | LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
|
---|
1130 | LWIP_DEBUGF(IP_DEBUG, ("| %3"U16_F" | %3"U16_F" | %3"U16_F" | %3"U16_F" | (dest)\n",
|
---|
1131 | ip4_addr1_16_val(iphdr->dest),
|
---|
1132 | ip4_addr2_16_val(iphdr->dest),
|
---|
1133 | ip4_addr3_16_val(iphdr->dest),
|
---|
1134 | ip4_addr4_16_val(iphdr->dest)));
|
---|
1135 | LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
|
---|
1136 | }
|
---|
1137 | #endif /* IP_DEBUG */
|
---|
1138 |
|
---|
1139 | #endif /* LWIP_IPV4 */
|
---|