1 | /* |
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2 | * bbftpd/bbftpd_check.c |
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3 | * Copyright (C) 1999, 2000, 2001, 2002 IN2P3, CNRS |
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4 | * bbftp@in2p3.fr |
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5 | * http://doc.in2p3.fr/bbftp |
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6 | * |
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7 | * This program is free software; you can redistribute it and/or |
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8 | * modify it under the terms of the GNU General Public License |
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9 | * as published by the Free Software Foundation; either version 2 |
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10 | * of the License, or any later version. |
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11 | * |
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12 | * This program is distributed in the hope that it will be useful, |
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13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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15 | * GNU General Public License for more details. |
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16 | * |
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17 | * You should have received a copy of the GNU General Public License |
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18 | * along with this program; if not, write to the Free Software |
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19 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
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20 | */ |
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21 | |
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22 | /**************************************************************************** |
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23 | |
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24 | |
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25 | Routines : void checkfromwhere() |
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26 | int checkprotocol() |
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27 | |
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28 | bbftpd_check.c v 2.0.0 2000/12/18 - Creation of the routine. |
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29 | v 2.0.1 2001/04/23 - Correct indentation |
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30 | v 2.1.0 2001/06/01 - Change file name |
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31 | - Reorganise routines as in bbftp_ |
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32 | |
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33 | *****************************************************************************/ |
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34 | #include <bbftpd.h> |
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35 | |
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36 | #include <stdlib.h> |
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37 | |
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38 | #include <errno.h> |
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39 | |
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40 | #include <bbftpd_private_log.h> |
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41 | |
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42 | #if TIME_WITH_SYS_TIME |
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43 | # include <sys/time.h> |
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44 | # include <time.h> |
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45 | #else |
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46 | # if HAVE_SYS_TIME_H |
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47 | # include <sys/time.h> |
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48 | # else |
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49 | # include <time.h> |
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50 | # endif |
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51 | #endif |
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52 | #include <unistd.h> |
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53 | #include <utime.h> |
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54 | #if HAVE_STRING_H |
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55 | # include <string.h> |
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56 | #endif |
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57 | |
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58 | #include <netinet/in.h> |
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59 | #include <sys/socket.h> |
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60 | #include <common.h> |
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61 | #include <daemon.h> |
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62 | #include <daemon_proto.h> |
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63 | #include <structures.h> |
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64 | #include <version.h> |
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65 | |
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66 | extern struct sockaddr_in his_addr; |
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67 | extern struct sockaddr_in ctrl_addr; |
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68 | extern int incontrolsock ; |
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69 | extern int outcontrolsock ; |
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70 | extern int recvcontrolto ; |
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71 | extern int sendcontrolto ; |
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72 | extern int checkstdinto ; |
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73 | extern int protocolversion ; |
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74 | extern int protocolmin ; |
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75 | extern int protocolmax ; |
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76 | extern int newcontrolport ; |
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77 | extern int fixeddataport; |
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78 | extern int pasvport_min; |
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79 | extern int pasvport_max; |
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80 | extern char currentusername[MAXLEN] ; |
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81 | |
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82 | /******************************************************************************* |
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83 | ** checkfromwhere : * |
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84 | ** * |
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85 | ** This routine get a socket on a port, send a MSG_LOGGED_STDIN and * |
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86 | ** wait for a connection on that port. * |
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87 | ** * |
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88 | ** RETURN: * |
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89 | ** No return but the routine exit in case of error. * |
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90 | *******************************************************************************/ |
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91 | |
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92 | |
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93 | void checkfromwhere() |
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94 | { |
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95 | int sock,ns,retcode,nfds ; |
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96 | #if defined(HAVE_SOCKLEN_T) |
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97 | socklen_t addrlen; |
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98 | #else |
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99 | int addrlen; |
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100 | #endif |
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101 | struct sockaddr_in server ; |
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102 | char buffer[MINMESSLEN] ; |
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103 | struct message *msg ; |
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104 | struct timeval wait_timer; |
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105 | fd_set selectmask ; |
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106 | struct linger li ; |
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107 | int on = 1 ; |
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108 | |
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109 | |
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110 | sock = socket ( AF_INET, SOCK_STREAM, IPPROTO_TCP ) ; |
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111 | if ( sock < 0 ) { |
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112 | bbftpd_log(BBFTPD_ERR, "Cannot create checkreceive socket : %s",strerror(errno)); |
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113 | reply(MSG_BAD,"Cannot create checkreceive socket") ; |
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114 | bbftpd_log(BBFTPD_INFO,"User %s disconnected",currentusername) ; |
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115 | exit(1) ; |
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116 | } |
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117 | if ( setsockopt(sock,SOL_SOCKET, SO_REUSEADDR,(char *)&on,sizeof(on)) < 0 ) { |
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118 | bbftpd_log(BBFTPD_ERR,"Cannot set SO_REUSEADDR on checkreceive socket : %s\n",strerror(errno)) ; |
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119 | reply(MSG_BAD,"Cannot set SO_REUSEADDR on checkreceive socket") ; |
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120 | bbftpd_log(BBFTPD_INFO,"User %s disconnected",currentusername) ; |
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121 | close(sock) ; |
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122 | exit(1) ; |
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123 | } |
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124 | li.l_onoff = 1 ; |
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125 | li.l_linger = 1 ; |
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126 | if ( setsockopt(sock,SOL_SOCKET,SO_LINGER,(char *)&li,sizeof(li)) < 0 ) { |
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127 | bbftpd_log(BBFTPD_ERR,"Cannot set SO_LINGER on checkreceive socket : %s\n",strerror(errno)) ; |
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128 | reply(MSG_BAD,"Cannot set SO_LINGER on checkreceive socket") ; |
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129 | bbftpd_log(BBFTPD_INFO,"User %s disconnected",currentusername) ; |
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130 | close(sock) ; |
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131 | exit(1) ; |
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132 | } |
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133 | |
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134 | server.sin_family = AF_INET; |
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135 | server.sin_addr.s_addr = INADDR_ANY; |
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136 | if ( fixeddataport == 1 ) { |
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137 | server.sin_port = htons(newcontrolport+1) ; |
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138 | } else { |
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139 | server.sin_port = 0 ; |
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140 | } |
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141 | if (fixeddataport == 0 && pasvport_min) { /* Try to bind within a range */ |
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142 | int port; |
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143 | for (port=pasvport_min; port<=pasvport_max; port++) { |
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144 | server.sin_port = htons(port); |
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145 | if (bind(sock,(struct sockaddr *) &server, sizeof(server) ) >= 0) break; |
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146 | } |
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147 | if (port>pasvport_max) { |
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148 | bbftpd_log(BBFTPD_ERR, "Cannot bind on data socket : %s",strerror(errno)); |
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149 | reply(MSG_BAD,"Cannot bind checkreceive socket") ; |
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150 | bbftpd_log(BBFTPD_INFO,"User %s disconnected",currentusername) ; |
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151 | close(sock) ; |
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152 | exit(1) ; |
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153 | } |
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154 | } else if ( bind (sock,(struct sockaddr *) &server, sizeof(server) ) < 0 ) { |
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155 | bbftpd_log(BBFTPD_ERR,"Error binding checkreceive socket : %s",strerror(errno)) ; |
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156 | reply(MSG_BAD,"Cannot bind checkreceive socket") ; |
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157 | bbftpd_log(BBFTPD_INFO,"User %s disconnected",currentusername) ; |
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158 | close(sock) ; |
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159 | exit(1) ; |
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160 | } |
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161 | addrlen = sizeof(server) ; |
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162 | if (getsockname(sock,(struct sockaddr *)&server, &addrlen) < 0) { |
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163 | bbftpd_log(BBFTPD_ERR,"Error getsockname checkreceive socket : %s",strerror(errno)) ; |
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164 | reply(MSG_BAD,"Cannot getsockname checkreceive socket") ; |
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165 | bbftpd_log(BBFTPD_INFO,"User %s disconnected",currentusername) ; |
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166 | close(sock) ; |
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167 | exit(1) ; |
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168 | } |
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169 | if ( listen(sock,1) < 0 ) { |
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170 | bbftpd_log(BBFTPD_ERR,"Error listening checkreceive socket : %s",strerror(errno)) ; |
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171 | reply(MSG_BAD,"Error listening checkreceive socket") ; |
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172 | bbftpd_log(BBFTPD_INFO,"User %s disconnected",currentusername) ; |
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173 | close(sock) ; |
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174 | exit(1) ; |
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175 | } |
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176 | bbftpd_log(BBFTPD_INFO, "listen port : %d",ntohs(server.sin_port)); |
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177 | /* |
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178 | ** Send the MSG_LOGGED_STDIN message |
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179 | */ |
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180 | msg = (struct message *)buffer ; |
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181 | msg->code = MSG_LOGGED_STDIN ; |
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182 | #ifndef WORDS_BIGENDIAN |
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183 | msg->msglen = ntohl(4) ; |
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184 | #else |
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185 | msg->msglen = 4 ; |
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186 | #endif |
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187 | if ( writemessage(outcontrolsock,buffer,MINMESSLEN,sendcontrolto) < 0 ) { |
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188 | bbftpd_log(BBFTPD_ERR,"Error writing checkreceive socket part 1") ; |
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189 | reply(MSG_BAD,"Error writing checkreceive socket") ; |
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190 | bbftpd_log(BBFTPD_INFO,"User %s disconnected",currentusername) ; |
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191 | close(sock) ; |
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192 | exit(1) ; |
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193 | } |
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194 | /* |
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195 | ** Send the port number |
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196 | */ |
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197 | #ifndef WORDS_BIGENDIAN |
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198 | msg->code = ntohl(ntohs(server.sin_port)) ; |
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199 | #else |
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200 | msg->code = server.sin_port ; |
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201 | #endif |
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202 | if ( writemessage(outcontrolsock,buffer,4,sendcontrolto) < 0 ) { |
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203 | bbftpd_log(BBFTPD_ERR,"Error writing checkreceive socket part 2") ; |
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204 | reply(MSG_BAD,"Error writing checkreceive socket") ; |
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205 | bbftpd_log(BBFTPD_INFO,"User %s disconnected",currentusername) ; |
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206 | exit(1) ; |
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207 | } |
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208 | /* |
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209 | ** Now wait on the socket for a connection |
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210 | */ |
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211 | nfds = sysconf(_SC_OPEN_MAX) ; |
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212 | FD_ZERO(&selectmask) ; |
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213 | FD_SET(sock,&selectmask) ; |
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214 | /* |
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215 | ** Set the timer for the connection |
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216 | */ |
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217 | wait_timer.tv_sec = checkstdinto ; |
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218 | wait_timer.tv_usec = 0 ; |
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219 | retcode = select(nfds,&selectmask,0,0,&wait_timer) ; |
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220 | if ( retcode < 0 ) { |
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221 | bbftpd_log(BBFTPD_ERR,"Error select checkreceive socket : %s ",strerror(errno)) ; |
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222 | reply(MSG_BAD,"Error select checkreceive socket") ; |
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223 | bbftpd_log(BBFTPD_INFO,"User %s disconnected",currentusername) ; |
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224 | close(sock) ; |
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225 | exit(1) ; |
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226 | } |
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227 | if ( retcode == 0 ) { |
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228 | /* |
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229 | ** Time out |
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230 | */ |
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231 | bbftpd_log(BBFTPD_ERR,"Time out select checkreceive socket ") ; |
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232 | reply(MSG_BAD,"Time Out select checkreceive socket") ; |
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233 | bbftpd_log(BBFTPD_INFO,"User %s disconnected",currentusername) ; |
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234 | close(sock) ; |
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235 | exit(1) ; |
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236 | } |
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237 | if ( (ns = accept(sock,0,0) ) < 0 ) { |
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238 | bbftpd_log(BBFTPD_ERR,"Error accept checkreceive socket ") ; |
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239 | reply(MSG_BAD,"Error accep checkreceive socket") ; |
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240 | bbftpd_log(BBFTPD_INFO,"User %s disconnected",currentusername) ; |
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241 | close(sock) ; |
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242 | exit(1) ; |
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243 | } |
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244 | close(sock) ; |
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245 | addrlen = sizeof(his_addr); |
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246 | if (getpeername(ns, (struct sockaddr *) &his_addr, &addrlen) < 0) { |
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247 | bbftpd_log(BBFTPD_ERR, "getpeername : %s",strerror(errno)); |
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248 | reply(MSG_BAD,"getpeername error") ; |
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249 | bbftpd_log(BBFTPD_INFO,"User %s disconnected",currentusername) ; |
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250 | close(ns) ; |
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251 | exit(1); |
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252 | } |
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253 | addrlen = sizeof(ctrl_addr); |
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254 | if (getsockname(ns, (struct sockaddr *) &ctrl_addr, &addrlen) < 0) { |
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255 | bbftpd_log(BBFTPD_ERR, "getsockname : %s",strerror(errno)); |
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256 | reply(MSG_BAD,"getsockname error") ; |
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257 | bbftpd_log(BBFTPD_INFO,"User %s disconnected",currentusername) ; |
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258 | close(ns) ; |
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259 | exit(1); |
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260 | } |
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261 | /* |
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262 | ** Now read the message |
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263 | */ |
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264 | if ( readmessage(ns,buffer,MINMESSLEN,recvcontrolto) < 0 ) { |
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265 | bbftpd_log(BBFTPD_ERR,"Error reading checkreceive socket") ; |
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266 | reply(MSG_BAD,"Error reading checkreceive socket") ; |
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267 | bbftpd_log(BBFTPD_INFO,"User %s disconnected",currentusername) ; |
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268 | close(ns) ; |
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269 | exit(1) ; |
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270 | } |
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271 | if (msg->code != MSG_IPADDR ) { |
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272 | bbftpd_log(BBFTPD_ERR,"Receive unkown message on checkreceive socket") ; |
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273 | reply(MSG_BAD,"Receive unkown message on checkreceive socket") ; |
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274 | bbftpd_log(BBFTPD_INFO,"User %s disconnected",currentusername) ; |
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275 | close(ns) ; |
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276 | exit(1); |
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277 | } |
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278 | /* |
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279 | ** Everything seems OK so send a MSG_IPADDR_OK on the |
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280 | ** control socket and close the connection |
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281 | */ |
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282 | msg->code = MSG_IPADDR_OK ; |
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283 | msg->msglen = 0 ; |
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284 | if ( writemessage(ns,buffer,MINMESSLEN,sendcontrolto) < 0 ) { |
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285 | bbftpd_log(BBFTPD_ERR,"Error writing checkreceive socket OK message") ; |
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286 | reply(MSG_BAD,"Error writing checkreceive socket OK message") ; |
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287 | bbftpd_log(BBFTPD_INFO,"User %s disconnected",currentusername) ; |
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288 | close(ns) ; |
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289 | exit(1) ; |
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290 | } |
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291 | /* |
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292 | ** set the port of ctrl_addr structure to the control port |
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293 | */ |
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294 | ctrl_addr.sin_port = htons(newcontrolport) ; |
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295 | /* |
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296 | ** Wait a while before closing |
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297 | */ |
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298 | close(ns) ; |
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299 | } |
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300 | |
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301 | |
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302 | /******************************************************************************* |
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303 | ** checkprotocol : * |
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304 | ** * |
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305 | ** This routine send it protocol version and wait for the client prorocol * |
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306 | ** version. * |
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307 | ** * |
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308 | ** RETURN: * |
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309 | ** 0 OK * |
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310 | ** -1 calling program exit * |
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311 | *******************************************************************************/ |
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312 | |
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313 | int checkprotocol() |
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314 | { |
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315 | |
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316 | char buffer[MINMESSLEN] ; |
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317 | struct message *msg ; |
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318 | int msglen ; |
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319 | |
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320 | msg = ( struct message * ) buffer ; |
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321 | msg->code = MSG_PROT_ANS ; |
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322 | #ifndef WORDS_BIGENDIAN |
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323 | msg->msglen = ntohl(MINMESSLEN) ; |
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324 | #else |
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325 | msg->msglen = MINMESSLEN ; |
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326 | #endif |
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327 | if ( writemessage(outcontrolsock,buffer,MINMESSLEN,sendcontrolto) < 0 ) { |
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328 | bbftpd_log(BBFTPD_ERR,"Error writing MSG_PROT_ANS part 1") ; |
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329 | return -1 ; |
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330 | } |
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331 | /* |
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332 | ** Send the min and max protocol version |
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333 | */ |
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334 | #ifndef WORDS_BIGENDIAN |
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335 | msg->code = ntohl(protocolmin) ; |
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336 | msg->msglen = ntohl(protocolmax) ; |
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337 | #else |
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338 | msg->code = protocolmin ; |
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339 | msg->msglen = protocolmax ; |
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340 | #endif |
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341 | if ( writemessage(outcontrolsock,buffer,MINMESSLEN,sendcontrolto) < 0 ) { |
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342 | bbftpd_log(BBFTPD_ERR,"Error writing MSG_PROT_ANS part 2") ; |
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343 | return -1 ; |
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344 | } |
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345 | /* |
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346 | ** And wait for the answer |
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347 | */ |
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348 | if ( readmessage(incontrolsock,buffer,MINMESSLEN,recvcontrolto) < 0 ) { |
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349 | bbftpd_log(BBFTPD_ERR,"Error waiting MSG_PROT_ANS") ; |
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350 | return -1 ; |
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351 | } |
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352 | if ( msg->code == MSG_PROT_ANS ) { |
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353 | #ifndef WORDS_BIGENDIAN |
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354 | msglen = ntohl(msg->msglen) ; |
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355 | #else |
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356 | msglen = msg->msglen ; |
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357 | #endif |
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358 | if ( msglen == 4 ) { |
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359 | if ( readmessage(incontrolsock,buffer,4,recvcontrolto) < 0 ) { |
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360 | bbftpd_log(BBFTPD_ERR,"Error waiting MSG_PROT_ANS (protocol version)") ; |
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361 | return -1 ; |
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362 | } |
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363 | #ifndef WORDS_BIGENDIAN |
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364 | msglen = ntohl(msg->code) ; |
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365 | #else |
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366 | msglen = msg->code ; |
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367 | #endif |
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368 | protocolversion = msglen ; |
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369 | return 0 ; |
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370 | } else { |
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371 | bbftpd_log(BBFTPD_ERR,"Unexpected length while MSG_PROT_ANS %d",msglen) ; |
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372 | return -1 ; |
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373 | } |
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374 | } else if ( msg->code == MSG_BAD_NO_RETRY ) { |
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375 | bbftpd_log(BBFTPD_ERR,"Incompatible server and client") ; |
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376 | return -1 ; |
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377 | } else { |
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378 | bbftpd_log(BBFTPD_ERR,"Unexpected message while MSG_PROT_ANS %d",msg->code) ; |
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379 | return -1 ; |
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380 | } |
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381 | |
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382 | |
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383 | } |
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