62
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1 #include "includes.h" |
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2 #include "ssh.h" |
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3 #include "tcp-accept.h" |
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4 #include "tcp-connect.h" |
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5 #include "dbutil.h" |
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6 #include "session.h" |
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7 #include "buffer.h" |
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8 #include "packet.h" |
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9 #include "listener.h" |
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10 #include "runopts.h" |
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11 |
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12 #ifndef DISABLE_SVR_REMOTETCPFWD |
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13 |
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14 static void send_msg_request_success(); |
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15 static void send_msg_request_failure(); |
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16 static int svr_cancelremotetcp(); |
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17 static int svr_remotetcpreq(); |
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18 |
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19 |
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20 const struct ChanType svr_chan_tcpdirect = { |
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21 1, /* sepfds */ |
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22 "direct-tcpip", |
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23 newtcpdirect, /* init */ |
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24 NULL, /* checkclose */ |
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25 NULL, /* reqhandler */ |
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26 NULL /* closehandler */ |
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27 }; |
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28 |
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29 static const struct ChanType svr_chan_tcpremote = { |
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30 1, /* sepfds */ |
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31 "forwarded-tcpip", |
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32 NULL, |
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33 NULL, |
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34 NULL, |
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35 NULL |
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36 }; |
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37 |
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38 /* At the moment this is completely used for tcp code (with the name reflecting |
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39 * that). If new request types are added, this should be replaced with code |
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40 * similar to the request-switching in chansession.c */ |
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41 void recv_msg_global_request_remotetcp() { |
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42 |
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43 unsigned char* reqname = NULL; |
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44 unsigned int namelen; |
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45 unsigned int wantreply = 0; |
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46 int ret = DROPBEAR_FAILURE; |
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47 |
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48 TRACE(("enter recv_msg_global_request_remotetcp")); |
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49 |
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50 if (opts.noremotetcp) { |
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51 TRACE(("leave recv_msg_global_request_remotetcp: remote tcp forwarding disabled")); |
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52 goto out; |
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53 } |
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54 |
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55 reqname = buf_getstring(ses.payload, &namelen); |
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56 wantreply = buf_getbyte(ses.payload); |
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57 |
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58 if (namelen > MAXNAMLEN) { |
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59 TRACE(("name len is wrong: %d", namelen)); |
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60 goto out; |
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61 } |
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62 |
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63 if (strcmp("tcpip-forward", reqname) == 0) { |
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64 ret = svr_remotetcpreq(); |
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65 } else if (strcmp("cancel-tcpip-forward", reqname) == 0) { |
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66 ret = svr_cancelremotetcp(); |
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67 } else { |
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68 TRACE(("reqname isn't tcpip-forward: '%s'", reqname)); |
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69 } |
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70 |
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71 out: |
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72 if (wantreply) { |
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73 if (ret == DROPBEAR_SUCCESS) { |
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74 send_msg_request_success(); |
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75 } else { |
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76 send_msg_request_failure(); |
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77 } |
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78 } |
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79 |
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80 m_free(reqname); |
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81 |
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82 TRACE(("leave recv_msg_global_request")); |
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83 } |
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84 |
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85 |
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86 static void send_msg_request_success() { |
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87 |
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88 CHECKCLEARTOWRITE(); |
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89 buf_putbyte(ses.writepayload, SSH_MSG_REQUEST_SUCCESS); |
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90 encrypt_packet(); |
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91 |
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92 } |
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93 |
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94 static void send_msg_request_failure() { |
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95 |
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96 CHECKCLEARTOWRITE(); |
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97 buf_putbyte(ses.writepayload, SSH_MSG_REQUEST_FAILURE); |
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98 encrypt_packet(); |
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99 |
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100 } |
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101 |
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102 static int matchtcp(void* typedata1, void* typedata2) { |
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103 |
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104 const struct TCPListener *info1 = (struct TCPListener*)typedata1; |
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105 const struct TCPListener *info2 = (struct TCPListener*)typedata2; |
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106 |
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107 return (info1->port == info2->port) |
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108 && (info1->chantype == info2->chantype) |
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109 && (strcmp(info1->addr, info2->addr) == 0); |
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110 } |
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111 |
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112 static int svr_cancelremotetcp() { |
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113 |
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114 int ret = DROPBEAR_FAILURE; |
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115 unsigned char * bindaddr = NULL; |
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116 unsigned int addrlen; |
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117 unsigned int port; |
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118 struct Listener * listener = NULL; |
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119 struct TCPListener tcpinfo; |
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120 |
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121 TRACE(("enter cancelremotetcp")); |
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122 |
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123 bindaddr = buf_getstring(ses.payload, &addrlen); |
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124 if (addrlen > MAX_IP_LEN) { |
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125 TRACE(("addr len too long: %d", addrlen)); |
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126 goto out; |
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127 } |
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128 |
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129 port = buf_getint(ses.payload); |
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130 |
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131 tcpinfo.addr = bindaddr; |
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132 tcpinfo.port = port; |
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133 listener = get_listener(CHANNEL_ID_TCPFORWARDED, &tcpinfo, matchtcp); |
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134 if (listener) { |
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135 remove_listener( listener ); |
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136 ret = DROPBEAR_SUCCESS; |
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137 } |
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138 |
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139 out: |
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140 m_free(bindaddr); |
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141 TRACE(("leave cancelremotetcp")); |
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142 return ret; |
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143 } |
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144 |
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145 static int svr_remotetcpreq() { |
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146 |
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147 int ret = DROPBEAR_FAILURE; |
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148 unsigned char * bindaddr = NULL; |
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149 unsigned int addrlen; |
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150 struct TCPListener *tcpinfo = NULL; |
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151 unsigned int port; |
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152 |
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153 TRACE(("enter remotetcpreq")); |
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154 |
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155 bindaddr = buf_getstring(ses.payload, &addrlen); |
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156 if (addrlen > MAX_IP_LEN) { |
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157 TRACE(("addr len too long: %d", addrlen)); |
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158 goto out; |
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159 } |
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160 |
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161 port = buf_getint(ses.payload); |
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162 |
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163 if (port == 0) { |
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164 dropbear_log(LOG_INFO, "Server chosen tcpfwd ports are unsupported"); |
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165 goto out; |
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166 } |
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167 |
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168 if (port < 1 || port > 65535) { |
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169 TRACE(("invalid port: %d", port)); |
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170 goto out; |
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171 } |
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172 |
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173 if (!ses.allowprivport && port < IPPORT_RESERVED) { |
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174 TRACE(("can't assign port < 1024 for non-root")); |
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175 goto out; |
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176 } |
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177 |
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178 tcpinfo = (struct TCPListener*)m_malloc(sizeof(struct TCPListener)); |
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179 tcpinfo->addr = bindaddr; |
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180 tcpinfo->port = port; |
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181 tcpinfo->localport = -1; |
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182 tcpinfo->chantype = &svr_chan_tcpremote; |
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183 |
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184 ret = listen_tcpfwd(tcpinfo); |
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185 |
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186 out: |
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187 if (ret == DROPBEAR_FAILURE) { |
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188 /* we only free it if a listener wasn't created, since the listener |
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189 * has to remember it if it's to be cancelled */ |
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190 m_free(tcpinfo->addr); |
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191 m_free(tcpinfo); |
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192 } |
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193 TRACE(("leave remotetcpreq")); |
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194 return ret; |
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195 } |
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196 #endif |