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1 /* udp.cpp
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2 *
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3 * Copyright (C) DFS Deutsche Flugsicherung (2004, 2005).
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4 * All Rights Reserved.
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5 *
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6 * UDP functions for IPv4
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7 * Multicast Doc: /usr/share/doc/howto/en/html/Multicast-HOWTO.html
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8 *
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9 * Version 0.2
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10 */
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11
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12 #include <stdio.h>
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13 #include <stdlib.h>
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14 #include <string.h>
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15
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16 /* Socket io */
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17 #include <sys/types.h>
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18 #include <sys/socket.h>
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19 #include <netinet/in.h>
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20 #include <netdb.h>
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21 #include <sys/time.h>
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22 #include <unistd.h>
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23 #include <sys/errno.h>
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24 #include <assert.h>
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25
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26 #include "udp.h"
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27 #include "intercomd.h"
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28
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29 int UDP_recv_init(int port)
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30 /* starte UDP LAN Empfang. Programm-Exit bei Fehler! */
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31 /* return: Filedescriptor fuer Empfang */
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32 /* in port: UDP Port Nummer */
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33 {
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34 int fd;
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35 struct sockaddr_in sock;
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36 int local_flag;
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37 socklen_t local_flagsize;
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38
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39 /* init UDP local1 */
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40 fd = socket(AF_INET, SOCK_DGRAM, 0);
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41 if (fd < 0) {
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42 fprintf(stderr, "if_recv_init(): socket() failed\n");
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43 exit(1);
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44 }
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45
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46 memset((char *) &sock, 0, sizeof(sock));
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47 sock.sin_family = AF_INET;
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48 sock.sin_addr.s_addr = htonl(INADDR_ANY);
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49 sock.sin_port = htons(port);
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50 if (bind(fd, (struct sockaddr *) &sock, sizeof(sock)) < 0) {
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51 fprintf(stderr, "if_recv_init(): bind() failed\n");
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52 exit(2);
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53 }
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54 local_flagsize = sizeof(int);
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55 if (getsockopt(fd, SOL_SOCKET, SO_RCVBUF, (char *) &local_flag,
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56 &local_flagsize) < 0) {
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57 fprintf(stderr, "if_recv_init(): getsockopt() failed\n");
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58 exit(3);
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59 }
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60 /* printf("SO_RCVBUF=%d\n", local_flag); */
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61
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62 /* printf("init socket\n"); */
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63 return fd;
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64 }
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65
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66 void UDP::send_init(char *foreign_name, int foreign_port, int local_fd_)
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67 /* Starte Versand von UDP Meldungen auf LAN */
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68 /* in foreign_name: IP-Adresse auf die gesendet wird */
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69 /* in foreign_port: UDP-Port auf den gesendet wird */
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70 {
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71 struct hostent *foreign_host;
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72 int local_flag;
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73 socklen_t local_flagsize;
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74
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75 local_fd = local_fd_;
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76
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77 /* turn on broadcast */
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78 local_flagsize = sizeof(int);
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79 if (getsockopt(local_fd, SOL_SOCKET, SO_BROADCAST,
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80 (char *) &local_flag, &local_flagsize) < 0) {
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81 fprintf(stderr, "udp_send_init(): getsockopt() failed\n");
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82 exit(3);
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83 }
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84 if (local_flag == 0) {
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85 local_flag = 1;
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86 setsockopt(local_fd, SOL_SOCKET, SO_BROADCAST, (char *) &local_flag,
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87 sizeof(int));
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88 local_flagsize = sizeof(int);
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89 if (getsockopt(local_fd, SOL_SOCKET, SO_BROADCAST,
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90 (char *) &local_flag, &local_flagsize) < 0) {
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91 fprintf(stderr, "udp_send_init() SO_BROADCAST failed\n");
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92 exit(3);
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93 }
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94 }
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95
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96 /* init foreign part */
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97 memset((char *) &foreign_sock, 0, sizeof(foreign_sock));
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98
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99 foreign_host = gethostbyname(foreign_name);
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100 if (foreign_host == NULL || foreign_host->h_length == 0) {
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101 fprintf(stderr, "udp_send_init(): gethostbyname() failed");
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102 exit(1);
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103 }
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104 memcpy(&foreign_sock.sin_addr.s_addr, foreign_host->h_addr_list[0],
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105 foreign_host->h_length);
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106 foreign_sock.sin_family = AF_INET;
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107 foreign_sock.sin_port = htons(foreign_port);
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108
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109
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110 in_addr_t to_ip = ntohl(foreign_sock.sin_addr.s_addr);
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111 char s[20];
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112 print_gui("c %s\n", iptoa(s, to_ip));
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113 }
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114
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115 void UDP::send(char *buf, int bytes)
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116 /* Sende UDP Meldung auf LAN */
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117 /* in buf: Meldung */
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118 /* in bytes: Laenge der Meldung */
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119 {
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120 int len;
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121
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122 len = sendto(local_fd,
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123 buf, bytes,
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124 0, (struct sockaddr *) &foreign_sock, sizeof(foreign_sock));
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125 if (len != bytes) {
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126 fprintf(stderr, "udp_send(): sendto() foreign failed ret=%d\n",
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127 len);
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128 }
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129 }
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130
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131 void UDP::send_close()
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132 {
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133 memset((char *) &foreign_sock, 0, sizeof(foreign_sock));
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134 }
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135
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136 // IP to ASCII
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137 char *iptoa(char *buf, in_addr_t ip)
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138 {
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139 int i1 = ip >> 24;
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140 int i2 = (ip >> 16) & 0xFF;
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141 int i3 = (ip >> 8) & 0xFF;
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142 int i4 = ip & 0xFF;
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143
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144 sprintf(buf, "%d.%d.%d.%d", i1, i2, i3, i4);
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145
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146 return buf;
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147 }
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148
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149 // ASCII to IP
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150 in_addr_t atoip(char *buf)
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151 {
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152 int i1, i2, i3, i4;
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153
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154 sscanf(buf, "%d.%d.%d.%d", &i1, &i2, &i3, &i4);
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155
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156 return i1 << 24 | i2 << 16 | i3 << 8 | i4;
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157 }
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