1 | #include <machine/rtems-bsd-kernel-space.h> |
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2 | |
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3 | /*- |
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4 | * Copyright (c) 1998 Brian Somers <brian@Awfulhak.org> |
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5 | * with the aid of code written by |
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6 | * Junichi SATOH <junichi@astec.co.jp> 1996, 1997. |
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7 | * All rights reserved. |
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8 | * |
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9 | * Redistribution and use in source and binary forms, with or without |
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10 | * modification, are permitted provided that the following conditions |
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11 | * are met: |
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12 | * 1. Redistributions of source code must retain the above copyright |
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13 | * notice, this list of conditions and the following disclaimer. |
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14 | * 2. Redistributions in binary form must reproduce the above copyright |
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15 | * notice, this list of conditions and the following disclaimer in the |
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16 | * documentation and/or other materials provided with the distribution. |
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17 | * |
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18 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND |
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19 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
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20 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
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21 | * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE |
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22 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
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23 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
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24 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
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25 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
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26 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
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27 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
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28 | * SUCH DAMAGE. |
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29 | */ |
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30 | |
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31 | #include <sys/cdefs.h> |
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32 | __FBSDID("$FreeBSD$"); |
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33 | |
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34 | #ifdef _KERNEL |
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35 | #include <rtems/bsd/sys/param.h> |
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36 | #include <sys/kernel.h> |
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37 | #include <sys/module.h> |
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38 | #else |
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39 | #include <errno.h> |
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40 | #include <sys/types.h> |
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41 | #include <stdio.h> |
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42 | #endif |
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43 | |
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44 | #include <netinet/in_systm.h> |
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45 | #include <netinet/in.h> |
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46 | #include <netinet/ip.h> |
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47 | #include <netinet/udp.h> |
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48 | |
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49 | #ifdef _KERNEL |
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50 | #include <netinet/libalias/alias.h> |
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51 | #include <netinet/libalias/alias_local.h> |
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52 | #include <netinet/libalias/alias_mod.h> |
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53 | #else |
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54 | #include "alias_local.h" |
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55 | #include "alias_mod.h" |
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56 | #endif |
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57 | |
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58 | #define CUSEEME_PORT_NUMBER 7648 |
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59 | |
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60 | static void |
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61 | AliasHandleCUSeeMeOut(struct libalias *la, struct ip *pip, |
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62 | struct alias_link *lnk); |
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63 | |
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64 | static void |
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65 | AliasHandleCUSeeMeIn(struct libalias *la, struct ip *pip, |
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66 | struct in_addr original_addr); |
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67 | |
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68 | static int |
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69 | fingerprint(struct libalias *la, struct alias_data *ah) |
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70 | { |
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71 | |
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72 | if (ah->dport == NULL || ah->oaddr == NULL) |
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73 | return (-1); |
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74 | if (ntohs(*ah->dport) == CUSEEME_PORT_NUMBER) |
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75 | return (0); |
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76 | return (-1); |
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77 | } |
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78 | |
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79 | static int |
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80 | protohandlerin(struct libalias *la, struct ip *pip, struct alias_data *ah) |
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81 | { |
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82 | |
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83 | AliasHandleCUSeeMeIn(la, pip, *ah->oaddr); |
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84 | return (0); |
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85 | } |
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86 | |
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87 | static int |
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88 | protohandlerout(struct libalias *la, struct ip *pip, struct alias_data *ah) |
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89 | { |
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90 | |
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91 | AliasHandleCUSeeMeOut(la, pip, ah->lnk); |
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92 | return (0); |
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93 | } |
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94 | |
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95 | /* Kernel module definition. */ |
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96 | struct proto_handler handlers[] = { |
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97 | { |
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98 | .pri = 120, |
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99 | .dir = OUT, |
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100 | .proto = UDP, |
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101 | .fingerprint = &fingerprint, |
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102 | .protohandler = &protohandlerout |
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103 | }, |
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104 | { |
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105 | .pri = 120, |
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106 | .dir = IN, |
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107 | .proto = UDP, |
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108 | .fingerprint = &fingerprint, |
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109 | .protohandler = &protohandlerin |
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110 | }, |
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111 | { EOH } |
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112 | }; |
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113 | |
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114 | static int |
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115 | mod_handler(module_t mod, int type, void *data) |
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116 | { |
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117 | int error; |
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118 | |
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119 | switch (type) { |
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120 | case MOD_LOAD: |
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121 | error = 0; |
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122 | LibAliasAttachHandlers(handlers); |
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123 | break; |
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124 | case MOD_UNLOAD: |
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125 | error = 0; |
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126 | LibAliasDetachHandlers(handlers); |
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127 | break; |
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128 | default: |
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129 | error = EINVAL; |
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130 | } |
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131 | return (error); |
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132 | } |
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133 | |
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134 | #ifdef _KERNEL |
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135 | static |
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136 | #endif |
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137 | moduledata_t |
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138 | alias_mod = { |
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139 | "alias_cuseeme", mod_handler, NULL |
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140 | }; |
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141 | |
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142 | #ifdef _KERNEL |
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143 | DECLARE_MODULE(alias_cuseeme, alias_mod, SI_SUB_DRIVERS, SI_ORDER_SECOND); |
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144 | MODULE_VERSION(alias_cuseeme, 1); |
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145 | MODULE_DEPEND(alias_cuseeme, libalias, 1, 1, 1); |
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146 | #endif |
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147 | |
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148 | /* CU-SeeMe Data Header */ |
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149 | struct cu_header { |
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150 | u_int16_t dest_family; |
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151 | u_int16_t dest_port; |
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152 | u_int32_t dest_addr; |
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153 | int16_t family; |
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154 | u_int16_t port; |
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155 | u_int32_t addr; |
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156 | u_int32_t seq; |
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157 | u_int16_t msg; |
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158 | u_int16_t data_type; |
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159 | u_int16_t packet_len; |
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160 | }; |
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161 | |
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162 | /* Open Continue Header */ |
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163 | struct oc_header { |
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164 | u_int16_t client_count; /* Number of client info structs */ |
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165 | u_int32_t seq_no; |
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166 | char user_name [20]; |
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167 | char reserved [4]; /* flags, version stuff, etc */ |
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168 | }; |
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169 | |
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170 | /* client info structures */ |
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171 | struct client_info { |
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172 | u_int32_t address;/* Client address */ |
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173 | char reserved [8]; /* Flags, pruning bitfield, packet |
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174 | * counts etc */ |
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175 | }; |
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176 | |
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177 | static void |
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178 | AliasHandleCUSeeMeOut(struct libalias *la, struct ip *pip, struct alias_link *lnk) |
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179 | { |
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180 | struct udphdr *ud = ip_next(pip); |
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181 | |
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182 | if (ntohs(ud->uh_ulen) - sizeof(struct udphdr) >= sizeof(struct cu_header)) { |
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183 | struct cu_header *cu; |
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184 | struct alias_link *cu_lnk; |
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185 | |
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186 | cu = udp_next(ud); |
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187 | if (cu->addr) |
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188 | cu->addr = (u_int32_t) GetAliasAddress(lnk).s_addr; |
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189 | |
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190 | cu_lnk = FindUdpTcpOut(la, pip->ip_src, GetDestAddress(lnk), |
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191 | ud->uh_dport, 0, IPPROTO_UDP, 1); |
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192 | |
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193 | #ifndef NO_FW_PUNCH |
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194 | if (cu_lnk) |
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195 | PunchFWHole(cu_lnk); |
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196 | #endif |
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197 | } |
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198 | } |
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199 | |
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200 | static void |
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201 | AliasHandleCUSeeMeIn(struct libalias *la, struct ip *pip, struct in_addr original_addr) |
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202 | { |
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203 | struct in_addr alias_addr; |
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204 | struct udphdr *ud; |
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205 | struct cu_header *cu; |
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206 | struct oc_header *oc; |
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207 | struct client_info *ci; |
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208 | char *end; |
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209 | int i; |
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210 | |
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211 | (void)la; |
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212 | alias_addr.s_addr = pip->ip_dst.s_addr; |
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213 | ud = ip_next(pip); |
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214 | cu = udp_next(ud); |
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215 | oc = (struct oc_header *)(cu + 1); |
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216 | ci = (struct client_info *)(oc + 1); |
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217 | end = (char *)ud + ntohs(ud->uh_ulen); |
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218 | |
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219 | if ((char *)oc <= end) { |
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220 | if (cu->dest_addr) |
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221 | cu->dest_addr = (u_int32_t) original_addr.s_addr; |
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222 | if (ntohs(cu->data_type) == 101) |
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223 | /* Find and change our address */ |
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224 | for (i = 0; (char *)(ci + 1) <= end && i < oc->client_count; i++, ci++) |
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225 | if (ci->address == (u_int32_t) alias_addr.s_addr) { |
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226 | ci->address = (u_int32_t) original_addr.s_addr; |
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227 | break; |
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228 | } |
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229 | } |
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230 | } |
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