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1 /* Copyright 2014 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 <stdbool.h> |
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28 #include <stdlib.h> |
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29 #include <unistd.h> |
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30 #include <sys/types.h> |
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31 #include <sys/uio.h> |
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32 #include <string.h> |
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33 #include <fcntl.h> |
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34 #include <sys/ioctl.h> |
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35 #include <net/if.h> |
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36 #ifdef linux |
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37 #include <linux/if_tun.h> |
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38 #include <linux/if_ether.h> |
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39 #else |
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40 #define ETH_FRAME_LEN 1514 |
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41 #include <net/if_tun.h> |
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42 #ifdef SOLARIS |
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43 #include <sys/stropts.h> |
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44 #include <sys/sockio.h> |
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45 #endif |
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46 #endif |
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47 #include "include.h" |
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48 |
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49 static unsigned char readbuffer[2000]; |
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50 |
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51 bool tunnel_write_data(tunnel_context* context, unsigned char* buffer, int len) { |
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52 if (context->fake_pi) { |
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53 if (len == 0) return true; |
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54 int ipver = (*buffer >> 4) & 0xf; |
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55 int pihdr = 0; |
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56 #if defined linux |
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57 if (ipver == 4) pihdr = 0x0000 | (0x0008 << 16); //little endian: flags and protocol are swapped |
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58 else if (ipver == 6) pihdr = 0x0000 | (0xdd86 << 16); |
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59 #else |
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60 if (ipver == 4) pihdr = htonl(AF_INET); |
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61 else if (ipver == 6) pihdr = htonl(AF_INET6); |
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62 #endif |
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63 struct iovec iov[2]; |
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64 iov[0].iov_base = &pihdr; |
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65 iov[0].iov_len = sizeof(pihdr); |
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66 iov[1].iov_base = buffer; |
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67 iov[1].iov_len = len; |
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68 writev(context->fd, iov, 2); |
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69 } else { |
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70 write(context->fd, buffer, len); |
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71 } |
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72 return true; |
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73 } |
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74 |
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75 bool tunnel_read(tunnel_context* context) { |
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76 int len = read(context->fd, readbuffer, sizeof(readbuffer)); |
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77 if (len < 0) return errorexitp("read failure on tap device"); |
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78 if (!context->connection) return true; |
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79 if (context->fake_pi) { |
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80 if (len < 4) return errorexit("short packet received from tap device"); |
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81 connection_write_data(context->connection, readbuffer + 4, len - 4); |
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82 } else { |
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83 connection_write_data(context->connection, readbuffer, len); |
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84 } |
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85 return true; |
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86 } |
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87 |
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88 bool tunnel_init(tunnel_context* context) { |
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89 memset(context, 0, sizeof(tunnel_context)); |
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90 char* envval; |
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91 fprintf(stderr, "Initializing tun/tap device...\n"); |
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92 int ttfd; //Tap device file descriptor |
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93 int tunmode = 0; |
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94 if ((envval = getconf("TUN_MODE"))) tunmode = atoi(envval); |
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95 #if defined(__linux__) |
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96 struct ifreq ifr; //required for tun/tap setup |
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97 memset(&ifr, 0, sizeof(ifr)); |
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98 if ((ttfd = open("/dev/net/tun", O_RDWR)) < 0) return errorexitp("Could not open tun/tap device file"); |
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99 if ((envval = getconf("INTERFACE"))) strcpy(ifr.ifr_name, envval); |
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100 ifr.ifr_flags = tunmode ? IFF_TUN : IFF_TAP; |
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101 ifr.ifr_flags |= IFF_NO_PI; |
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102 if (ioctl(ttfd, TUNSETIFF, (void *)&ifr) < 0) return errorexitp("TUNSETIFF ioctl failed"); |
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103 #elif defined SOLARIS |
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104 int ip_fd = -1, if_fd = -1, ppa = 0; |
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105 if ((ttfd = open("/dev/tun", O_RDWR)) < 0) return errorexitp("Could not open tun device file"); |
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106 if ((ip_fd = open("/dev/ip", O_RDWR, 0)) < 0) return errorexitp("Could not open /dev/ip"); |
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107 if ((envval = getconf("INTERFACE"))) { |
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108 while (*envval && !isdigit((int)*envval)) envval++; |
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109 ppa = atoi(envval); |
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110 } |
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111 if ((ppa = ioctl(ttfd, TUNNEWPPA, ppa)) < 0) return errorexitp("Could not assign new PPA"); |
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112 if ((if_fd = open("/dev/tun", O_RDWR, 0)) < 0) return errorexitp("Could not open tun device file again"); |
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113 if (ioctl(if_fd, I_PUSH, "ip") < 0) return errorexitp("Could not push IP module"); |
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114 if (ioctl(if_fd, IF_UNITSEL, (char *)&ppa) < 0) return errorexitp("Could not set PPA"); |
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115 if (ioctl(ip_fd, I_LINK, if_fd) < 0) return errorexitp("Could not link TUN device to IP"); |
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116 #else |
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117 if (!(envval = getconf("INTERFACE"))) envval = "/dev/tun0"; |
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118 if ((ttfd = open(envval, O_RDWR)) < 0) return errorexitp("Could not open tun device file"); |
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119 if (tunmode) { |
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120 int i = IFF_POINTOPOINT | IFF_MULTICAST; |
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121 ioctl(ttfd, TUNSIFMODE, &i); |
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122 #if defined(__OpenBSD__) |
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123 context->fake_pi = true; |
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124 #else |
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125 i = 1; |
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126 ioctl(ttfd, TUNSIFHEAD, &i); |
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127 #endif |
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128 } |
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129 #endif |
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130 if ((envval = getconf("TUN_UP_SCRIPT"))) system(envval); |
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131 context->fd = ttfd; |
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132 return true; |
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133 } |
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134 |
