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1 /* Copyright 2010 Ivo Smits <Ivo@UCIS.nl>. All rights reserved. |
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2 Redistribution and use in source and binary forms, with or without modification, are |
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3 permitted provided that the following conditions are met: |
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4 |
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5 1. Redistributions of source code must retain the above copyright notice, this list of |
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6 conditions and the following disclaimer. |
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7 |
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8 2. Redistributions in binary form must reproduce the above copyright notice, this list |
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9 of conditions and the following disclaimer in the documentation and/or other materials |
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10 provided with the distribution. |
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11 |
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12 THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED |
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13 WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND |
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14 FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR |
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15 CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
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16 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR |
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17 SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON |
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18 ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING |
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19 NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF |
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20 ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
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21 |
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22 The views and conclusions contained in the software and documentation are those of the |
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23 authors and should not be interpreted as representing official policies, either expressed |
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24 or implied, of Ivo Smits.*/ |
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25 |
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26 #include <stdio.h> |
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27 #include <stdlib.h> |
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28 #include <string.h> |
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29 #include <fcntl.h> |
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30 #ifndef HAVE_NETINET_IN_H |
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31 #include <netinet/in.h> |
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32 #endif |
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33 #include <sys/ioctl.h> |
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34 #include <linux/if.h> |
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35 #include <linux/if_tun.h> |
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36 #include <linux/if_ether.h> |
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37 #include <poll.h> |
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38 #include <netdb.h> |
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39 #include <stdlib.h> |
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40 |
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41 #define MAX_PACKET_LEN (ETH_FRAME_LEN+4) //Some space for optional packet information |
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42 |
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43 struct qtsession; |
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44 struct qtproto { |
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45 int encrypted; |
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46 int buffersize_raw; |
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47 int buffersize_enc; |
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48 int offset_raw; |
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49 int offset_enc; |
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50 int (*encode)(struct qtsession* sess, char* raw, char* enc, int len); |
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51 int (*decode)(struct qtsession* sess, char* enc, char* raw, int len); |
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52 int (*init)(struct qtsession* sess); |
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53 int protocol_data_size; |
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54 }; |
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55 struct qtsession { |
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56 struct qtproto protocol; |
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57 void* protocol_data; |
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58 int fd_socket; |
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59 int fd_dev; |
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60 int remote_float; |
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61 struct sockaddr_in remote_addr; |
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62 }; |
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63 |
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64 #ifdef COMBINED_BINARY |
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65 extern char* (*getconf)(const char*); |
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66 extern int errorexit(const char*); |
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67 extern int errorexitp(const char*); |
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68 extern void print_header(); |
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69 extern void hex2bin(unsigned char*, unsigned char*, int); |
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70 #else |
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71 |
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72 char* (*getconf)(const char*) = getenv; |
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73 |
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74 int errorexit(const char* text) { |
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75 fprintf(stderr, "%s\n", text); |
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76 return -1; |
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77 } |
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78 int errorexitp(const char* text) { |
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79 perror(text); |
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80 return -1; |
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81 } |
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82 |
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83 void print_header() { |
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84 printf("UCIS QuickTun (c) 2010 Ivo Smits <Ivo@UCIS.nl>\n"); |
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85 printf("More information: http://wiki.qontrol.nl/QuickTun\n"); |
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86 } |
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87 |
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88 int init_udp(struct qtsession* session) { |
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89 char* envval; |
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90 printf("Initializing UDP socket...\n"); |
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91 int sfd = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP); |
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92 if (sfd < 0) return errorexitp("Could not create UDP socket"); |
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93 struct sockaddr_in udpaddr; |
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94 struct hostent *he; |
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95 udpaddr.sin_family = AF_INET; |
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96 udpaddr.sin_addr.s_addr = INADDR_ANY; |
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97 udpaddr.sin_port = htons(2998); |
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98 if (envval = getconf("LOCAL_ADDRESS")) { |
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99 he = gethostbyname(envval); |
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100 if (!he) return errorexit("bind address lookup failed"); |
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101 else if (!he->h_addr_list[0]) return errorexit("no address to bind to"); |
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102 udpaddr.sin_addr.s_addr = *((unsigned long*)he->h_addr_list[0]); |
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103 udpaddr.sin_family = he->h_addrtype; |
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104 } |
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105 if (envval = getconf("LOCAL_PORT")) { |
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106 udpaddr.sin_port = htons(atoi(envval)); |
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107 } |
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108 if (bind(sfd, (struct sockaddr*)&udpaddr, sizeof(struct sockaddr_in))) return errorexitp("Could not bind socket"); |
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109 if (!(envval = getconf("REMOTE_ADDRESS"))) { |
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110 session->remote_float = 1; |
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111 //return errorexit("Missing REMOTE_ADDRESS"); |
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112 } else { |
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113 session->remote_float = 0; |
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114 he = gethostbyname(envval); |
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115 if (!he) return errorexit("remote address lookup failed"); |
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116 else if (!he->h_addr_list[0]) return errorexit("no address to connect to"); |
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117 udpaddr.sin_family = he->h_addrtype; |
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118 udpaddr.sin_addr.s_addr = *((unsigned long*)he->h_addr_list[0]); |
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119 if (envval = getconf("REMOTE_PORT")) { |
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120 udpaddr.sin_port = htons(atoi(envval)); |
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121 } |
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122 if (connect(sfd, (struct sockaddr*)&udpaddr, sizeof(struct sockaddr_in))) return errorexitp("Could not connect socket"); |
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123 session->remote_addr = udpaddr; |
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124 } |
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125 session->fd_socket = sfd; |
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126 return sfd; |
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127 } |
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128 |
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129 int init_tuntap() { |
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130 char* envval; |
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131 printf("Initializing tap device...\n"); |
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132 int ttfd; //Tap device file descriptor |
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133 struct ifreq ifr; //required for tun/tap setup |
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134 memset(&ifr, 0, sizeof(ifr)); |
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135 if ((ttfd = open("/dev/net/tun", O_RDWR)) < 0) return errorexitp("Could not open tap device file"); |
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136 if (envval = getconf("INTERFACE")) strcpy(ifr.ifr_name, envval); |
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137 ifr.ifr_flags = getconf("TUN_MODE") ? IFF_TUN : IFF_TAP; |
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138 ifr.ifr_flags |= getconf("USE_PI") ? 0 : IFF_NO_PI; |
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139 if (ioctl(ttfd, TUNSETIFF, (void *)&ifr) < 0) return errorexitp("TUNSETIFF ioctl failed"); |
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140 return ttfd; |
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141 } |
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142 |
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143 void hex2bin(unsigned char* dest, unsigned char* src, int count) { |
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144 int i; |
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145 for (i = 0; i < count; i++) { |
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146 if (*src >= '0' && *src <= '9') *dest = *src - '0'; |
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147 else if (*src >= 'a' && * src <='f') *dest = *src - 'a' + 10; |
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148 else if (*src >= 'A' && * src <='F') *dest = *src - 'A' + 10; |
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149 src++; *dest = *dest << 4; |
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150 if (*src >= '0' && *src <= '9') *dest += *src - '0'; |
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151 else if (*src >= 'a' && *src <= 'f') *dest += *src - 'a' + 10; |
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152 else if (*src >= 'A' && *src <= 'F') *dest += *src - 'A' + 10; |
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153 src++; dest++; |
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154 } |
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155 } |
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156 |
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157 int qtrun(struct qtproto* p) { |
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158 struct qtsession session; |
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159 session.protocol = *p; |
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160 init_udp(&session); |
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161 session.fd_dev = init_tuntap(); |
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162 |
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163 char protocol_data[p->protocol_data_size]; |
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164 session.protocol_data = &protocol_data; |
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165 if (p->init) p->init(&session); |
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166 |
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167 int sfd = session.fd_socket; |
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168 int ttfd = session.fd_dev; |
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169 if (sfd == -1) return -1; |
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170 if (ttfd == -1) return -1; |
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171 printf("The tunnel is now operational!\n"); |
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172 |
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173 struct pollfd fds[2]; |
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174 fds[0].fd = ttfd; |
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175 fds[0].events = POLLIN; |
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176 fds[1].fd = sfd; |
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177 fds[1].events = POLLIN; |
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178 |
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179 struct sockaddr_in recvaddr; |
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180 |
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181 char buffer_raw_a[p->buffersize_raw]; |
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182 char buffer_enc_a[p->buffersize_enc]; |
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183 char* buffer_raw = buffer_raw_a; |
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184 char* buffer_enc = buffer_enc_a; |
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185 |
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186 while (1) { |
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187 int len = poll(fds, 2, -1); |
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188 if (len < 0) return errorexitp("poll error"); |
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189 else if (fds[0].revents & (POLLERR | POLLHUP | POLLNVAL)) return errorexit("poll error on tap device"); |
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190 else if (fds[1].revents & (POLLHUP | POLLNVAL)) return errorexit("poll error on udp socket"); |
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191 if (fds[0].revents & POLLIN) { |
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192 if (session.remote_float == 0 || session.remote_float == 2) { |
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193 len = read(ttfd, buffer_raw + p->offset_raw, p->buffersize_raw); |
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194 len = p->encode(&session, buffer_raw, buffer_enc, len); |
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195 if (len < 0) return len; |
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196 if (session.remote_float == 0) { |
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197 write(sfd, buffer_enc + p->offset_enc, len); |
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198 } else { |
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199 sendto(sfd, buffer_enc + p->offset_enc, len, 0, (struct sockaddr*)&session.remote_addr, sizeof(session.remote_addr)); |
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200 } |
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201 } |
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202 } |
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203 if (fds[1].revents & POLLIN) { |
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204 socklen_t recvaddr_len = sizeof(recvaddr); |
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205 if (session.remote_float == 0) { |
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206 len = read(sfd, buffer_enc + p->offset_enc, p->buffersize_enc); |
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207 } else { |
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208 len = recvfrom(sfd, buffer_enc + p->offset_enc, p->buffersize_enc, 0, (struct sockaddr*)&recvaddr, &recvaddr_len); |
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209 } |
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210 if (len < 0) { |
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211 int out; |
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212 len = 4; |
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213 getsockopt(sfd, SOL_SOCKET, SO_ERROR, &out, &len); |
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214 fprintf(stderr, "End of file on udp socket"); |
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215 } else { |
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216 len = p->decode(&session, buffer_enc, buffer_raw, len); |
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217 if (len != 0 && session.remote_float != 0 && (session.remote_addr.sin_addr.s_addr != recvaddr.sin_addr.s_addr || session.remote_addr.sin_port != recvaddr.sin_port)) { |
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218 fprintf(stderr, "Remote endpoint has changed to %s:%d", inet_ntoa(recvaddr.sin_addr), ntohs(recvaddr.sin_port)); |
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219 session.remote_addr = recvaddr; |
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220 session.remote_float = 2; |
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221 } |
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222 if (len < 0) return len; |
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223 write(ttfd, buffer_raw + p->offset_raw, len); |
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224 } |
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225 } |
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226 } |
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227 return 0; |
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228 } |
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229 #endif |
