1 | /* |
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2 | * This file Copyright (C) 2007-2014 Mnemosyne LLC |
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3 | * |
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4 | * It may be used under the GNU GPL versions 2 or 3 |
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5 | * or any future license endorsed by Mnemosyne LLC. |
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6 | * |
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7 | * $Id: natpmp.c 14532 2015-05-31 22:13:31Z mikedld $ |
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8 | */ |
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9 | |
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10 | #include <errno.h> |
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11 | #include <time.h> |
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12 | #include <inttypes.h> |
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13 | |
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14 | #include <event2/util.h> /* evutil_inet_ntop () */ |
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15 | |
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16 | #define ENABLE_STRNATPMPERR |
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17 | #include "natpmp.h" |
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18 | |
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19 | #include "transmission.h" |
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20 | #include "natpmp_local.h" |
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21 | #include "log.h" |
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22 | #include "net.h" /* tr_netCloseSocket */ |
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23 | #include "port-forwarding.h" |
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24 | #include "utils.h" |
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25 | |
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26 | #define LIFETIME_SECS 3600 |
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27 | #define COMMAND_WAIT_SECS 8 |
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28 | |
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29 | static const char * |
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30 | getKey (void) { return _("Port Forwarding (NAT-PMP)"); } |
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31 | |
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32 | typedef enum |
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33 | { |
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34 | TR_NATPMP_IDLE, |
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35 | TR_NATPMP_ERR, |
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36 | TR_NATPMP_DISCOVER, |
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37 | TR_NATPMP_RECV_PUB, |
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38 | TR_NATPMP_SEND_MAP, |
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39 | TR_NATPMP_RECV_MAP, |
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40 | TR_NATPMP_SEND_UNMAP, |
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41 | TR_NATPMP_RECV_UNMAP |
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42 | } |
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43 | tr_natpmp_state; |
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44 | |
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45 | struct tr_natpmp |
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46 | { |
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47 | bool has_discovered; |
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48 | bool is_mapped; |
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49 | |
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50 | tr_port public_port; |
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51 | tr_port private_port; |
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52 | |
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53 | time_t renew_time; |
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54 | time_t command_time; |
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55 | tr_natpmp_state state; |
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56 | natpmp_t natpmp; |
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57 | }; |
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58 | |
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59 | /** |
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60 | *** |
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61 | **/ |
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62 | |
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63 | static void |
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64 | logVal (const char * func, |
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65 | int ret) |
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66 | { |
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67 | if (ret == NATPMP_TRYAGAIN) |
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68 | return; |
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69 | if (ret >= 0) |
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70 | tr_logAddNamedInfo (getKey (), _("%s succeeded (%d)"), func, ret); |
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71 | else |
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72 | tr_logAddNamedDbg ( |
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73 | getKey (), |
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74 | "%s failed. Natpmp returned %d (%s); errno is %d (%s)", |
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75 | func, ret, strnatpmperr (ret), errno, tr_strerror (errno)); |
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76 | } |
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77 | |
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78 | struct tr_natpmp* |
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79 | tr_natpmpInit (void) |
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80 | { |
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81 | struct tr_natpmp * nat; |
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82 | |
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83 | nat = tr_new0 (struct tr_natpmp, 1); |
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84 | nat->state = TR_NATPMP_DISCOVER; |
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85 | nat->public_port = 0; |
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86 | nat->private_port = 0; |
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87 | nat->natpmp.s = TR_BAD_SOCKET; /* socket */ |
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88 | return nat; |
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89 | } |
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90 | |
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91 | void |
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92 | tr_natpmpClose (tr_natpmp * nat) |
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93 | { |
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94 | if (nat) |
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95 | { |
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96 | closenatpmp (&nat->natpmp); |
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97 | tr_free (nat); |
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98 | } |
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99 | } |
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100 | |
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101 | static bool |
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102 | canSendCommand (const struct tr_natpmp * nat) |
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103 | { |
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104 | return tr_time () >= nat->command_time; |
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105 | } |
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106 | |
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107 | static void |
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108 | setCommandTime (struct tr_natpmp * nat) |
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109 | { |
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110 | nat->command_time = tr_time () + COMMAND_WAIT_SECS; |
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111 | } |
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112 | |
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113 | int |
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114 | tr_natpmpPulse (struct tr_natpmp * nat, tr_port private_port, bool is_enabled, tr_port * public_port) |
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115 | { |
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116 | int ret; |
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117 | |
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118 | if (is_enabled && (nat->state == TR_NATPMP_DISCOVER)) |
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119 | { |
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120 | int val = initnatpmp (&nat->natpmp, 0, 0); |
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121 | logVal ("initnatpmp", val); |
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122 | val = sendpublicaddressrequest (&nat->natpmp); |
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123 | logVal ("sendpublicaddressrequest", val); |
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124 | nat->state = val < 0 ? TR_NATPMP_ERR : TR_NATPMP_RECV_PUB; |
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125 | nat->has_discovered = true; |
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126 | setCommandTime (nat); |
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127 | } |
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128 | |
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129 | if ((nat->state == TR_NATPMP_RECV_PUB) && canSendCommand (nat)) |
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130 | { |
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131 | natpmpresp_t response; |
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132 | const int val = readnatpmpresponseorretry (&nat->natpmp, &response); |
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133 | logVal ("readnatpmpresponseorretry", val); |
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134 | if (val >= 0) |
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135 | { |
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136 | char str[128]; |
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137 | evutil_inet_ntop (AF_INET, &response.pnu.publicaddress.addr, str, sizeof (str)); |
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138 | tr_logAddNamedInfo (getKey (), _("Found public address \"%s\""), str); |
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139 | nat->state = TR_NATPMP_IDLE; |
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140 | } |
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141 | else if (val != NATPMP_TRYAGAIN) |
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142 | { |
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143 | nat->state = TR_NATPMP_ERR; |
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144 | } |
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145 | } |
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146 | |
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147 | if ((nat->state == TR_NATPMP_IDLE) || (nat->state == TR_NATPMP_ERR)) |
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148 | { |
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149 | if (nat->is_mapped && (!is_enabled || (nat->private_port != private_port))) |
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150 | nat->state = TR_NATPMP_SEND_UNMAP; |
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151 | } |
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152 | |
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153 | if ((nat->state == TR_NATPMP_SEND_UNMAP) && canSendCommand (nat)) |
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154 | { |
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155 | const int val = sendnewportmappingrequest (&nat->natpmp, NATPMP_PROTOCOL_TCP, |
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156 | nat->private_port, |
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157 | nat->public_port, |
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158 | 0); |
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159 | logVal ("sendnewportmappingrequest", val); |
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160 | nat->state = val < 0 ? TR_NATPMP_ERR : TR_NATPMP_RECV_UNMAP; |
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161 | setCommandTime (nat); |
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162 | } |
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163 | |
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164 | if (nat->state == TR_NATPMP_RECV_UNMAP) |
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165 | { |
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166 | natpmpresp_t resp; |
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167 | const int val = readnatpmpresponseorretry (&nat->natpmp, &resp); |
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168 | logVal ("readnatpmpresponseorretry", val); |
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169 | if (val >= 0) |
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170 | { |
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171 | const int private_port = resp.pnu.newportmapping.privateport; |
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172 | |
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173 | tr_logAddNamedInfo (getKey (), _("no longer forwarding port %d"), private_port); |
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174 | |
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175 | if (nat->private_port == private_port) |
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176 | { |
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177 | nat->private_port = 0; |
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178 | nat->public_port = 0; |
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179 | nat->state = TR_NATPMP_IDLE; |
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180 | nat->is_mapped = false; |
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181 | } |
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182 | } |
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183 | else if (val != NATPMP_TRYAGAIN) |
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184 | { |
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185 | nat->state = TR_NATPMP_ERR; |
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186 | } |
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187 | } |
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188 | |
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189 | if (nat->state == TR_NATPMP_IDLE) |
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190 | { |
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191 | if (is_enabled && !nat->is_mapped && nat->has_discovered) |
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192 | nat->state = TR_NATPMP_SEND_MAP; |
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193 | |
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194 | else if (nat->is_mapped && tr_time () >= nat->renew_time) |
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195 | nat->state = TR_NATPMP_SEND_MAP; |
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196 | } |
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197 | |
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198 | if ((nat->state == TR_NATPMP_SEND_MAP) && canSendCommand (nat)) |
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199 | { |
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200 | const int val = sendnewportmappingrequest (&nat->natpmp, NATPMP_PROTOCOL_TCP, private_port, private_port, LIFETIME_SECS); |
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201 | logVal ("sendnewportmappingrequest", val); |
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202 | nat->state = val < 0 ? TR_NATPMP_ERR : TR_NATPMP_RECV_MAP; |
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203 | setCommandTime (nat); |
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204 | } |
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205 | |
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206 | if (nat->state == TR_NATPMP_RECV_MAP) |
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207 | { |
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208 | natpmpresp_t resp; |
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209 | const int val = readnatpmpresponseorretry (&nat->natpmp, &resp); |
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210 | logVal ("readnatpmpresponseorretry", val); |
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211 | if (val >= 0) |
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212 | { |
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213 | nat->state = TR_NATPMP_IDLE; |
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214 | nat->is_mapped = true; |
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215 | nat->renew_time = tr_time () + (resp.pnu.newportmapping.lifetime / 2); |
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216 | nat->private_port = resp.pnu.newportmapping.privateport; |
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217 | nat->public_port = resp.pnu.newportmapping.mappedpublicport; |
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218 | tr_logAddNamedInfo (getKey (), _("Port %d forwarded successfully"), nat->private_port); |
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219 | } |
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220 | else if (val != NATPMP_TRYAGAIN) |
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221 | { |
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222 | nat->state = TR_NATPMP_ERR; |
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223 | } |
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224 | } |
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225 | |
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226 | switch (nat->state) |
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227 | { |
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228 | case TR_NATPMP_IDLE: |
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229 | *public_port = nat->public_port; |
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230 | return nat->is_mapped ? TR_PORT_MAPPED : TR_PORT_UNMAPPED; |
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231 | break; |
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232 | |
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233 | case TR_NATPMP_DISCOVER: |
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234 | ret = TR_PORT_UNMAPPED; break; |
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235 | |
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236 | case TR_NATPMP_RECV_PUB: |
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237 | case TR_NATPMP_SEND_MAP: |
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238 | case TR_NATPMP_RECV_MAP: |
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239 | ret = TR_PORT_MAPPING; break; |
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240 | |
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241 | case TR_NATPMP_SEND_UNMAP: |
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242 | case TR_NATPMP_RECV_UNMAP: |
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243 | ret = TR_PORT_UNMAPPING; break; |
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244 | |
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245 | default: |
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246 | ret = TR_PORT_ERROR; break; |
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247 | } |
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248 | return ret; |
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249 | } |
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250 | |
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