2 * Network proxy abstraction in PuTTY
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4 * A proxy layer, if necessary, wedges itself between the network
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5 * code and the higher level backend.
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12 #define DEFINE_PLUG_METHOD_MACROS
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14 #include "network.h"
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17 #define do_proxy_dns(conf) \
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18 (conf_get_int(conf, CONF_proxy_dns) == FORCE_ON || \
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19 (conf_get_int(conf, CONF_proxy_dns) == AUTO && \
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20 conf_get_int(conf, CONF_proxy_type) != PROXY_SOCKS4))
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23 * Call this when proxy negotiation is complete, so that this
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24 * socket can begin working normally.
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26 void proxy_activate (Proxy_Socket p)
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30 long output_before, output_after;
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32 p->state = PROXY_STATE_ACTIVE;
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34 /* we want to ignore new receive events until we have sent
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35 * all of our buffered receive data.
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37 sk_set_frozen(p->sub_socket, 1);
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39 /* how many bytes of output have we buffered? */
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40 output_before = bufchain_size(&p->pending_oob_output_data) +
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41 bufchain_size(&p->pending_output_data);
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42 /* and keep track of how many bytes do not get sent. */
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45 /* send buffered OOB writes */
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46 while (bufchain_size(&p->pending_oob_output_data) > 0) {
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47 bufchain_prefix(&p->pending_oob_output_data, &data, &len);
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48 output_after += sk_write_oob(p->sub_socket, data, len);
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49 bufchain_consume(&p->pending_oob_output_data, len);
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52 /* send buffered normal writes */
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53 while (bufchain_size(&p->pending_output_data) > 0) {
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54 bufchain_prefix(&p->pending_output_data, &data, &len);
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55 output_after += sk_write(p->sub_socket, data, len);
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56 bufchain_consume(&p->pending_output_data, len);
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59 /* if we managed to send any data, let the higher levels know. */
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60 if (output_after < output_before)
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61 plug_sent(p->plug, output_after);
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63 /* if we were asked to flush the output during
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64 * the proxy negotiation process, do so now.
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66 if (p->pending_flush) sk_flush(p->sub_socket);
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68 /* if we have a pending EOF to send, send it */
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69 if (p->pending_eof) sk_write_eof(p->sub_socket);
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71 /* if the backend wanted the socket unfrozen, try to unfreeze.
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72 * our set_frozen handler will flush buffered receive data before
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73 * unfreezing the actual underlying socket.
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76 sk_set_frozen((Socket)p, 0);
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79 /* basic proxy socket functions */
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81 static Plug sk_proxy_plug (Socket s, Plug p)
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83 Proxy_Socket ps = (Proxy_Socket) s;
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84 Plug ret = ps->plug;
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90 static void sk_proxy_close (Socket s)
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92 Proxy_Socket ps = (Proxy_Socket) s;
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94 sk_close(ps->sub_socket);
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95 sk_addr_free(ps->remote_addr);
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99 static int sk_proxy_write (Socket s, const char *data, int len)
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101 Proxy_Socket ps = (Proxy_Socket) s;
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103 if (ps->state != PROXY_STATE_ACTIVE) {
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104 bufchain_add(&ps->pending_output_data, data, len);
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105 return bufchain_size(&ps->pending_output_data);
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107 return sk_write(ps->sub_socket, data, len);
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110 static int sk_proxy_write_oob (Socket s, const char *data, int len)
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112 Proxy_Socket ps = (Proxy_Socket) s;
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114 if (ps->state != PROXY_STATE_ACTIVE) {
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115 bufchain_clear(&ps->pending_output_data);
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116 bufchain_clear(&ps->pending_oob_output_data);
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117 bufchain_add(&ps->pending_oob_output_data, data, len);
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120 return sk_write_oob(ps->sub_socket, data, len);
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123 static void sk_proxy_write_eof (Socket s)
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125 Proxy_Socket ps = (Proxy_Socket) s;
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127 if (ps->state != PROXY_STATE_ACTIVE) {
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128 ps->pending_eof = 1;
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131 sk_write_eof(ps->sub_socket);
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134 static void sk_proxy_flush (Socket s)
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136 Proxy_Socket ps = (Proxy_Socket) s;
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138 if (ps->state != PROXY_STATE_ACTIVE) {
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139 ps->pending_flush = 1;
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142 sk_flush(ps->sub_socket);
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145 static void sk_proxy_set_private_ptr (Socket s, void *ptr)
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147 Proxy_Socket ps = (Proxy_Socket) s;
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148 sk_set_private_ptr(ps->sub_socket, ptr);
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151 static void * sk_proxy_get_private_ptr (Socket s)
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153 Proxy_Socket ps = (Proxy_Socket) s;
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154 return sk_get_private_ptr(ps->sub_socket);
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157 static void sk_proxy_set_frozen (Socket s, int is_frozen)
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159 Proxy_Socket ps = (Proxy_Socket) s;
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161 if (ps->state != PROXY_STATE_ACTIVE) {
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162 ps->freeze = is_frozen;
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166 /* handle any remaining buffered recv data first */
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167 if (bufchain_size(&ps->pending_input_data) > 0) {
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168 ps->freeze = is_frozen;
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170 /* loop while we still have buffered data, and while we are
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171 * unfrozen. the plug_receive call in the loop could result
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172 * in a call back into this function refreezing the socket,
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173 * so we have to check each time.
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175 while (!ps->freeze && bufchain_size(&ps->pending_input_data) > 0) {
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179 bufchain_prefix(&ps->pending_input_data, &data, &len);
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180 if (len > lenof(databuf))
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181 len = lenof(databuf);
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182 memcpy(databuf, data, len);
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183 bufchain_consume(&ps->pending_input_data, len);
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184 plug_receive(ps->plug, 0, databuf, len);
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187 /* if we're still frozen, we'll have to wait for another
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188 * call from the backend to finish unbuffering the data.
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190 if (ps->freeze) return;
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193 sk_set_frozen(ps->sub_socket, is_frozen);
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196 static const char * sk_proxy_socket_error (Socket s)
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198 Proxy_Socket ps = (Proxy_Socket) s;
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199 if (ps->error != NULL || ps->sub_socket == NULL) {
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202 return sk_socket_error(ps->sub_socket);
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205 /* basic proxy plug functions */
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207 static void plug_proxy_log(Plug plug, int type, SockAddr addr, int port,
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208 const char *error_msg, int error_code)
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210 Proxy_Plug pp = (Proxy_Plug) plug;
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211 Proxy_Socket ps = pp->proxy_socket;
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213 plug_log(ps->plug, type, addr, port, error_msg, error_code);
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216 static int plug_proxy_closing (Plug p, const char *error_msg,
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217 int error_code, int calling_back)
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219 Proxy_Plug pp = (Proxy_Plug) p;
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220 Proxy_Socket ps = pp->proxy_socket;
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222 if (ps->state != PROXY_STATE_ACTIVE) {
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223 ps->closing_error_msg = error_msg;
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224 ps->closing_error_code = error_code;
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225 ps->closing_calling_back = calling_back;
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226 return ps->negotiate(ps, PROXY_CHANGE_CLOSING);
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228 return plug_closing(ps->plug, error_msg,
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229 error_code, calling_back);
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232 static int plug_proxy_receive (Plug p, int urgent, char *data, int len)
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234 Proxy_Plug pp = (Proxy_Plug) p;
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235 Proxy_Socket ps = pp->proxy_socket;
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237 if (ps->state != PROXY_STATE_ACTIVE) {
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238 /* we will lose the urgentness of this data, but since most,
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239 * if not all, of this data will be consumed by the negotiation
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240 * process, hopefully it won't affect the protocol above us
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242 bufchain_add(&ps->pending_input_data, data, len);
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243 ps->receive_urgent = urgent;
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244 ps->receive_data = data;
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245 ps->receive_len = len;
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246 return ps->negotiate(ps, PROXY_CHANGE_RECEIVE);
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248 return plug_receive(ps->plug, urgent, data, len);
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251 static void plug_proxy_sent (Plug p, int bufsize)
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253 Proxy_Plug pp = (Proxy_Plug) p;
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254 Proxy_Socket ps = pp->proxy_socket;
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256 if (ps->state != PROXY_STATE_ACTIVE) {
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257 ps->sent_bufsize = bufsize;
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258 ps->negotiate(ps, PROXY_CHANGE_SENT);
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261 plug_sent(ps->plug, bufsize);
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264 static int plug_proxy_accepting (Plug p, OSSocket sock)
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266 Proxy_Plug pp = (Proxy_Plug) p;
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267 Proxy_Socket ps = pp->proxy_socket;
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269 if (ps->state != PROXY_STATE_ACTIVE) {
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270 ps->accepting_sock = sock;
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271 return ps->negotiate(ps, PROXY_CHANGE_ACCEPTING);
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273 return plug_accepting(ps->plug, sock);
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277 * This function can accept a NULL pointer as `addr', in which case
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278 * it will only check the host name.
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280 static int proxy_for_destination (SockAddr addr, const char *hostname,
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281 int port, Conf *conf)
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285 int hostip_len, hostname_len;
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286 const char *exclude_list;
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289 * Special local connections such as Unix-domain sockets
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290 * unconditionally cannot be proxied, even in proxy-localhost
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291 * mode. There just isn't any way to ask any known proxy type for
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294 if (addr && sk_address_is_special_local(addr))
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295 return 0; /* do not proxy */
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298 * Check the host name and IP against the hard-coded
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299 * representations of `localhost'.
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301 if (!conf_get_int(conf, CONF_even_proxy_localhost) &&
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302 (sk_hostname_is_local(hostname) ||
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303 (addr && sk_address_is_local(addr))))
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304 return 0; /* do not proxy */
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306 /* we want a string representation of the IP address for comparisons */
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308 sk_getaddr(addr, hostip, 64);
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309 hostip_len = strlen(hostip);
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311 hostip_len = 0; /* placate gcc; shouldn't be required */
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313 hostname_len = strlen(hostname);
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315 exclude_list = conf_get_str(conf, CONF_proxy_exclude_list);
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317 /* now parse the exclude list, and see if either our IP
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318 * or hostname matches anything in it.
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321 while (exclude_list[s]) {
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322 while (exclude_list[s] &&
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323 (isspace((unsigned char)exclude_list[s]) ||
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324 exclude_list[s] == ',')) s++;
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326 if (!exclude_list[s]) break;
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330 while (exclude_list[e] &&
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331 (isalnum((unsigned char)exclude_list[e]) ||
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332 exclude_list[e] == '-' ||
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333 exclude_list[e] == '.' ||
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334 exclude_list[e] == '*')) e++;
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336 if (exclude_list[s] == '*') {
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337 /* wildcard at beginning of entry */
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339 if ((addr && strnicmp(hostip + hostip_len - (e - s - 1),
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340 exclude_list + s + 1, e - s - 1) == 0) ||
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341 strnicmp(hostname + hostname_len - (e - s - 1),
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342 exclude_list + s + 1, e - s - 1) == 0)
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343 return 0; /* IP/hostname range excluded. do not use proxy. */
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345 } else if (exclude_list[e-1] == '*') {
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346 /* wildcard at end of entry */
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348 if ((addr && strnicmp(hostip, exclude_list + s, e - s - 1) == 0) ||
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349 strnicmp(hostname, exclude_list + s, e - s - 1) == 0)
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350 return 0; /* IP/hostname range excluded. do not use proxy. */
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353 /* no wildcard at either end, so let's try an absolute
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354 * match (ie. a specific IP)
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357 if (addr && strnicmp(hostip, exclude_list + s, e - s) == 0)
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358 return 0; /* IP/hostname excluded. do not use proxy. */
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359 if (strnicmp(hostname, exclude_list + s, e - s) == 0)
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360 return 0; /* IP/hostname excluded. do not use proxy. */
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365 /* Make sure we really have reached the next comma or end-of-string */
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366 while (exclude_list[s] &&
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367 !isspace((unsigned char)exclude_list[s]) &&
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368 exclude_list[s] != ',') s++;
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371 /* no matches in the exclude list, so use the proxy */
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375 SockAddr name_lookup(char *host, int port, char **canonicalname,
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376 Conf *conf, int addressfamily)
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378 if (conf_get_int(conf, CONF_proxy_type) != PROXY_NONE &&
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379 do_proxy_dns(conf) &&
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380 proxy_for_destination(NULL, host, port, conf)) {
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381 *canonicalname = dupstr(host);
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382 return sk_nonamelookup(host);
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385 return sk_namelookup(host, canonicalname, addressfamily);
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388 Socket new_connection(SockAddr addr, char *hostname,
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389 int port, int privport,
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390 int oobinline, int nodelay, int keepalive,
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391 Plug plug, Conf *conf)
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393 static const struct socket_function_table socket_fn_table = {
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397 sk_proxy_write_oob,
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398 sk_proxy_write_eof,
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400 sk_proxy_set_private_ptr,
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401 sk_proxy_get_private_ptr,
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402 sk_proxy_set_frozen,
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403 sk_proxy_socket_error
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406 static const struct plug_function_table plug_fn_table = {
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408 plug_proxy_closing,
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409 plug_proxy_receive,
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411 plug_proxy_accepting
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414 if (conf_get_int(conf, CONF_proxy_type) != PROXY_NONE &&
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415 proxy_for_destination(addr, hostname, port, conf))
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419 SockAddr proxy_addr;
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420 char *proxy_canonical_name;
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424 if ((sret = platform_new_connection(addr, hostname, port, privport,
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425 oobinline, nodelay, keepalive,
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430 ret = snew(struct Socket_proxy_tag);
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431 ret->fn = &socket_fn_table;
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432 ret->conf = conf_copy(conf);
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434 ret->remote_addr = addr; /* will need to be freed on close */
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435 ret->remote_port = port;
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438 ret->pending_flush = 0;
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439 ret->pending_eof = 0;
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442 bufchain_init(&ret->pending_input_data);
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443 bufchain_init(&ret->pending_output_data);
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444 bufchain_init(&ret->pending_oob_output_data);
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446 ret->sub_socket = NULL;
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447 ret->state = PROXY_STATE_NEW;
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448 ret->negotiate = NULL;
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450 type = conf_get_int(conf, CONF_proxy_type);
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451 if (type == PROXY_HTTP) {
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452 ret->negotiate = proxy_http_negotiate;
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453 } else if (type == PROXY_SOCKS4) {
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454 ret->negotiate = proxy_socks4_negotiate;
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455 } else if (type == PROXY_SOCKS5) {
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456 ret->negotiate = proxy_socks5_negotiate;
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457 } else if (type == PROXY_TELNET) {
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458 ret->negotiate = proxy_telnet_negotiate;
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460 ret->error = "Proxy error: Unknown proxy method";
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461 return (Socket) ret;
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464 /* create the proxy plug to map calls from the actual
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465 * socket into our proxy socket layer */
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466 pplug = snew(struct Plug_proxy_tag);
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467 pplug->fn = &plug_fn_table;
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468 pplug->proxy_socket = ret;
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470 /* look-up proxy */
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471 proxy_addr = sk_namelookup(conf_get_str(conf, CONF_proxy_host),
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472 &proxy_canonical_name,
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473 conf_get_int(conf, CONF_addressfamily));
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474 if (sk_addr_error(proxy_addr) != NULL) {
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475 ret->error = "Proxy error: Unable to resolve proxy host name";
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477 sk_addr_free(proxy_addr);
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478 return (Socket)ret;
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480 sfree(proxy_canonical_name);
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482 /* create the actual socket we will be using,
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483 * connected to our proxy server and port.
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485 ret->sub_socket = sk_new(proxy_addr,
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486 conf_get_int(conf, CONF_proxy_port),
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487 privport, oobinline,
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488 nodelay, keepalive, (Plug) pplug);
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489 if (sk_socket_error(ret->sub_socket) != NULL)
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490 return (Socket) ret;
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492 /* start the proxy negotiation process... */
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493 sk_set_frozen(ret->sub_socket, 0);
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494 ret->negotiate(ret, PROXY_CHANGE_NEW);
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496 return (Socket) ret;
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499 /* no proxy, so just return the direct socket */
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500 return sk_new(addr, port, privport, oobinline, nodelay, keepalive, plug);
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503 Socket new_listener(char *srcaddr, int port, Plug plug, int local_host_only,
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504 Conf *conf, int addressfamily)
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506 /* TODO: SOCKS (and potentially others) support inbound
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507 * TODO: connections via the proxy. support them.
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510 return sk_newlistener(srcaddr, port, plug, local_host_only, addressfamily);
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513 /* ----------------------------------------------------------------------
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514 * HTTP CONNECT proxy type.
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517 static int get_line_end (char * data, int len)
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523 if (data[off] == '\n') {
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524 /* we have a newline */
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527 /* is that the only thing on this line? */
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528 if (off <= 2) return off;
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530 /* if not, then there is the possibility that this header
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531 * continues onto the next line, if it starts with a space
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535 if (off + 1 < len &&
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536 data[off+1] != ' ' &&
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537 data[off+1] != '\t') return off;
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539 /* the line does continue, so we have to keep going
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540 * until we see an the header's "real" end of line.
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551 int proxy_http_negotiate (Proxy_Socket p, int change)
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553 if (p->state == PROXY_STATE_NEW) {
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554 /* we are just beginning the proxy negotiate process,
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555 * so we'll send off the initial bits of the request.
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556 * for this proxy method, it's just a simple HTTP
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559 char *buf, dest[512];
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560 char *username, *password;
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562 sk_getaddr(p->remote_addr, dest, lenof(dest));
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564 buf = dupprintf("CONNECT %s:%i HTTP/1.1\r\nHost: %s:%i\r\n",
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565 dest, p->remote_port, dest, p->remote_port);
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566 sk_write(p->sub_socket, buf, strlen(buf));
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569 username = conf_get_str(p->conf, CONF_proxy_username);
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570 password = conf_get_str(p->conf, CONF_proxy_password);
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571 if (username[0] || password[0]) {
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574 buf = dupprintf("%s:%s", username, password);
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576 buf2 = snewn(len * 4 / 3 + 100, char);
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577 sprintf(buf2, "Proxy-Authorization: Basic ");
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578 for (i = 0, j = strlen(buf2); i < len; i += 3, j += 4)
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579 base64_encode_atom((unsigned char *)(buf+i),
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580 (len-i > 3 ? 3 : len-i), buf2+j);
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581 strcpy(buf2+j, "\r\n");
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582 sk_write(p->sub_socket, buf2, strlen(buf2));
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587 sk_write(p->sub_socket, "\r\n", 2);
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593 if (change == PROXY_CHANGE_CLOSING) {
\r
594 /* if our proxy negotiation process involves closing and opening
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595 * new sockets, then we would want to intercept this closing
\r
596 * callback when we were expecting it. if we aren't anticipating
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597 * a socket close, then some error must have occurred. we'll
\r
598 * just pass those errors up to the backend.
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600 return plug_closing(p->plug, p->closing_error_msg,
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601 p->closing_error_code,
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602 p->closing_calling_back);
\r
605 if (change == PROXY_CHANGE_SENT) {
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606 /* some (or all) of what we wrote to the proxy was sent.
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607 * we don't do anything new, however, until we receive the
\r
608 * proxy's response. we might want to set a timer so we can
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609 * timeout the proxy negotiation after a while...
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614 if (change == PROXY_CHANGE_ACCEPTING) {
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615 /* we should _never_ see this, as we are using our socket to
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616 * connect to a proxy, not accepting inbound connections.
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617 * what should we do? close the socket with an appropriate
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620 return plug_accepting(p->plug, p->accepting_sock);
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623 if (change == PROXY_CHANGE_RECEIVE) {
\r
624 /* we have received data from the underlying socket, which
\r
625 * we'll need to parse, process, and respond to appropriately.
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628 char *data, *datap;
\r
632 if (p->state == 1) {
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634 int min_ver, maj_ver, status;
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636 /* get the status line */
\r
637 len = bufchain_size(&p->pending_input_data);
\r
638 assert(len > 0); /* or we wouldn't be here */
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639 data = snewn(len+1, char);
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640 bufchain_fetch(&p->pending_input_data, data, len);
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642 * We must NUL-terminate this data, because Windows
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643 * sscanf appears to require a NUL at the end of the
\r
644 * string because it strlens it _first_. Sigh.
\r
648 eol = get_line_end(data, len);
\r
655 /* We can't rely on whether the %n incremented the sscanf return */
\r
656 if (sscanf((char *)data, "HTTP/%i.%i %n",
\r
657 &maj_ver, &min_ver, &status) < 2 || status == -1) {
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658 plug_closing(p->plug, "Proxy error: HTTP response was absent",
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659 PROXY_ERROR_GENERAL, 0);
\r
664 /* remove the status line from the input buffer. */
\r
665 bufchain_consume(&p->pending_input_data, eol);
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666 if (data[status] != '2') {
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670 while (eol > status &&
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671 (data[eol-1] == '\r' || data[eol-1] == '\n'))
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672 data[--eol] = '\0';
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673 buf = dupprintf("Proxy error: %s", data+status);
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674 plug_closing(p->plug, buf, PROXY_ERROR_GENERAL, 0);
\r
685 if (p->state == 2) {
\r
687 /* get headers. we're done when we get a
\r
688 * header of length 2, (ie. just "\r\n")
\r
691 len = bufchain_size(&p->pending_input_data);
\r
692 assert(len > 0); /* or we wouldn't be here */
\r
693 data = snewn(len, char);
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695 bufchain_fetch(&p->pending_input_data, data, len);
\r
697 eol = get_line_end(datap, len);
\r
704 bufchain_consume(&p->pending_input_data, eol);
\r
707 eol = get_line_end(datap, len);
\r
712 bufchain_consume(&p->pending_input_data, 2);
\r
714 /* proxy activate will have dealt with
\r
715 * whatever is left of the buffer */
\r
725 plug_closing(p->plug, "Proxy error: unexpected proxy error",
\r
726 PROXY_ERROR_UNEXPECTED, 0);
\r
730 /* ----------------------------------------------------------------------
\r
731 * SOCKS proxy type.
\r
734 /* SOCKS version 4 */
\r
735 int proxy_socks4_negotiate (Proxy_Socket p, int change)
\r
737 if (p->state == PROXY_CHANGE_NEW) {
\r
740 * version number (1 byte) = 4
\r
741 * command code (1 byte)
\r
744 * dest. port (2 bytes) [network order]
\r
745 * dest. address (4 bytes)
\r
746 * user ID (variable length, null terminated string)
\r
749 int length, type, namelen;
\r
750 char *command, addr[4], hostname[512];
\r
753 type = sk_addrtype(p->remote_addr);
\r
754 if (type == ADDRTYPE_IPV6) {
\r
755 p->error = "Proxy error: SOCKS version 4 does not support IPv6";
\r
757 } else if (type == ADDRTYPE_IPV4) {
\r
759 sk_addrcopy(p->remote_addr, addr);
\r
760 } else { /* type == ADDRTYPE_NAME */
\r
761 assert(type == ADDRTYPE_NAME);
\r
762 sk_getaddr(p->remote_addr, hostname, lenof(hostname));
\r
763 namelen = strlen(hostname) + 1; /* include the NUL */
\r
764 addr[0] = addr[1] = addr[2] = 0;
\r
768 username = conf_get_str(p->conf, CONF_proxy_username);
\r
769 length = strlen(username) + namelen + 9;
\r
770 command = snewn(length, char);
\r
771 strcpy(command + 8, username);
\r
773 command[0] = 4; /* version 4 */
\r
774 command[1] = 1; /* CONNECT command */
\r
777 command[2] = (char) (p->remote_port >> 8) & 0xff;
\r
778 command[3] = (char) p->remote_port & 0xff;
\r
781 memcpy(command + 4, addr, 4);
\r
784 memcpy(command + 8 + strlen(username) + 1,
\r
785 hostname, namelen);
\r
787 sk_write(p->sub_socket, command, length);
\r
795 if (change == PROXY_CHANGE_CLOSING) {
\r
796 /* if our proxy negotiation process involves closing and opening
\r
797 * new sockets, then we would want to intercept this closing
\r
798 * callback when we were expecting it. if we aren't anticipating
\r
799 * a socket close, then some error must have occurred. we'll
\r
800 * just pass those errors up to the backend.
\r
802 return plug_closing(p->plug, p->closing_error_msg,
\r
803 p->closing_error_code,
\r
804 p->closing_calling_back);
\r
807 if (change == PROXY_CHANGE_SENT) {
\r
808 /* some (or all) of what we wrote to the proxy was sent.
\r
809 * we don't do anything new, however, until we receive the
\r
810 * proxy's response. we might want to set a timer so we can
\r
811 * timeout the proxy negotiation after a while...
\r
816 if (change == PROXY_CHANGE_ACCEPTING) {
\r
817 /* we should _never_ see this, as we are using our socket to
\r
818 * connect to a proxy, not accepting inbound connections.
\r
819 * what should we do? close the socket with an appropriate
\r
822 return plug_accepting(p->plug, p->accepting_sock);
\r
825 if (change == PROXY_CHANGE_RECEIVE) {
\r
826 /* we have received data from the underlying socket, which
\r
827 * we'll need to parse, process, and respond to appropriately.
\r
830 if (p->state == 1) {
\r
831 /* response format:
\r
832 * version number (1 byte) = 4
\r
833 * reply code (1 byte)
\r
834 * 90 = request granted
\r
835 * 91 = request rejected or failed
\r
836 * 92 = request rejected due to lack of IDENTD on client
\r
837 * 93 = request rejected due to difference in user ID
\r
838 * (what we sent vs. what IDENTD said)
\r
839 * dest. port (2 bytes)
\r
840 * dest. address (4 bytes)
\r
845 if (bufchain_size(&p->pending_input_data) < 8)
\r
846 return 1; /* not got anything yet */
\r
848 /* get the response */
\r
849 bufchain_fetch(&p->pending_input_data, data, 8);
\r
851 if (data[0] != 0) {
\r
852 plug_closing(p->plug, "Proxy error: SOCKS proxy responded with "
\r
853 "unexpected reply code version",
\r
854 PROXY_ERROR_GENERAL, 0);
\r
858 if (data[1] != 90) {
\r
862 plug_closing(p->plug, "Proxy error: SOCKS server wanted IDENTD on client",
\r
863 PROXY_ERROR_GENERAL, 0);
\r
866 plug_closing(p->plug, "Proxy error: Username and IDENTD on client don't agree",
\r
867 PROXY_ERROR_GENERAL, 0);
\r
871 plug_closing(p->plug, "Proxy error: Error while communicating with proxy",
\r
872 PROXY_ERROR_GENERAL, 0);
\r
878 bufchain_consume(&p->pending_input_data, 8);
\r
882 /* proxy activate will have dealt with
\r
883 * whatever is left of the buffer */
\r
888 plug_closing(p->plug, "Proxy error: unexpected proxy error",
\r
889 PROXY_ERROR_UNEXPECTED, 0);
\r
893 /* SOCKS version 5 */
\r
894 int proxy_socks5_negotiate (Proxy_Socket p, int change)
\r
896 if (p->state == PROXY_CHANGE_NEW) {
\r
898 /* initial command:
\r
899 * version number (1 byte) = 5
\r
900 * number of available authentication methods (1 byte)
\r
901 * available authentication methods (1 byte * previous value)
\r
902 * authentication methods:
\r
903 * 0x00 = no authentication
\r
905 * 0x02 = username/password
\r
910 char *username, *password;
\r
913 command[0] = 5; /* version 5 */
\r
914 username = conf_get_str(p->conf, CONF_proxy_username);
\r
915 password = conf_get_str(p->conf, CONF_proxy_password);
\r
916 if (username[0] || password[0]) {
\r
917 command[2] = 0x00; /* no authentication */
\r
919 proxy_socks5_offerencryptedauth (command, &len);
\r
920 command[len++] = 0x02; /* username/password */
\r
921 command[1] = len - 2; /* Number of methods supported */
\r
923 command[1] = 1; /* one methods supported: */
\r
924 command[2] = 0x00; /* no authentication */
\r
928 sk_write(p->sub_socket, command, len);
\r
934 if (change == PROXY_CHANGE_CLOSING) {
\r
935 /* if our proxy negotiation process involves closing and opening
\r
936 * new sockets, then we would want to intercept this closing
\r
937 * callback when we were expecting it. if we aren't anticipating
\r
938 * a socket close, then some error must have occurred. we'll
\r
939 * just pass those errors up to the backend.
\r
941 return plug_closing(p->plug, p->closing_error_msg,
\r
942 p->closing_error_code,
\r
943 p->closing_calling_back);
\r
946 if (change == PROXY_CHANGE_SENT) {
\r
947 /* some (or all) of what we wrote to the proxy was sent.
\r
948 * we don't do anything new, however, until we receive the
\r
949 * proxy's response. we might want to set a timer so we can
\r
950 * timeout the proxy negotiation after a while...
\r
955 if (change == PROXY_CHANGE_ACCEPTING) {
\r
956 /* we should _never_ see this, as we are using our socket to
\r
957 * connect to a proxy, not accepting inbound connections.
\r
958 * what should we do? close the socket with an appropriate
\r
961 return plug_accepting(p->plug, p->accepting_sock);
\r
964 if (change == PROXY_CHANGE_RECEIVE) {
\r
965 /* we have received data from the underlying socket, which
\r
966 * we'll need to parse, process, and respond to appropriately.
\r
969 if (p->state == 1) {
\r
971 /* initial response:
\r
972 * version number (1 byte) = 5
\r
973 * authentication method (1 byte)
\r
974 * authentication methods:
\r
975 * 0x00 = no authentication
\r
977 * 0x02 = username/password
\r
979 * 0xff = no acceptable methods
\r
983 if (bufchain_size(&p->pending_input_data) < 2)
\r
984 return 1; /* not got anything yet */
\r
986 /* get the response */
\r
987 bufchain_fetch(&p->pending_input_data, data, 2);
\r
989 if (data[0] != 5) {
\r
990 plug_closing(p->plug, "Proxy error: SOCKS proxy returned unexpected version",
\r
991 PROXY_ERROR_GENERAL, 0);
\r
995 if (data[1] == 0x00) p->state = 2; /* no authentication needed */
\r
996 else if (data[1] == 0x01) p->state = 4; /* GSSAPI authentication */
\r
997 else if (data[1] == 0x02) p->state = 5; /* username/password authentication */
\r
998 else if (data[1] == 0x03) p->state = 6; /* CHAP authentication */
\r
1000 plug_closing(p->plug, "Proxy error: SOCKS proxy did not accept our authentication",
\r
1001 PROXY_ERROR_GENERAL, 0);
\r
1004 bufchain_consume(&p->pending_input_data, 2);
\r
1007 if (p->state == 7) {
\r
1009 /* password authentication reply format:
\r
1010 * version number (1 bytes) = 1
\r
1011 * reply code (1 byte)
\r
1017 if (bufchain_size(&p->pending_input_data) < 2)
\r
1018 return 1; /* not got anything yet */
\r
1020 /* get the response */
\r
1021 bufchain_fetch(&p->pending_input_data, data, 2);
\r
1023 if (data[0] != 1) {
\r
1024 plug_closing(p->plug, "Proxy error: SOCKS password "
\r
1025 "subnegotiation contained wrong version number",
\r
1026 PROXY_ERROR_GENERAL, 0);
\r
1030 if (data[1] != 0) {
\r
1032 plug_closing(p->plug, "Proxy error: SOCKS proxy refused"
\r
1033 " password authentication",
\r
1034 PROXY_ERROR_GENERAL, 0);
\r
1038 bufchain_consume(&p->pending_input_data, 2);
\r
1039 p->state = 2; /* now proceed as authenticated */
\r
1042 if (p->state == 8) {
\r
1044 ret = proxy_socks5_handlechap(p);
\r
1045 if (ret) return ret;
\r
1048 if (p->state == 2) {
\r
1050 /* request format:
\r
1051 * version number (1 byte) = 5
\r
1052 * command code (1 byte)
\r
1055 * 3 = UDP ASSOCIATE
\r
1056 * reserved (1 byte) = 0x00
\r
1057 * address type (1 byte)
\r
1059 * 3 = domainname (first byte has length, no terminating null)
\r
1061 * dest. address (variable)
\r
1062 * dest. port (2 bytes) [network order]
\r
1065 char command[512];
\r
1069 type = sk_addrtype(p->remote_addr);
\r
1070 if (type == ADDRTYPE_IPV4) {
\r
1071 len = 10; /* 4 hdr + 4 addr + 2 trailer */
\r
1072 command[3] = 1; /* IPv4 */
\r
1073 sk_addrcopy(p->remote_addr, command+4);
\r
1074 } else if (type == ADDRTYPE_IPV6) {
\r
1075 len = 22; /* 4 hdr + 16 addr + 2 trailer */
\r
1076 command[3] = 4; /* IPv6 */
\r
1077 sk_addrcopy(p->remote_addr, command+4);
\r
1079 assert(type == ADDRTYPE_NAME);
\r
1081 sk_getaddr(p->remote_addr, command+5, 256);
\r
1082 command[4] = strlen(command+5);
\r
1083 len = 7 + command[4]; /* 4 hdr, 1 len, N addr, 2 trailer */
\r
1086 command[0] = 5; /* version 5 */
\r
1087 command[1] = 1; /* CONNECT command */
\r
1088 command[2] = 0x00;
\r
1091 command[len-2] = (char) (p->remote_port >> 8) & 0xff;
\r
1092 command[len-1] = (char) p->remote_port & 0xff;
\r
1094 sk_write(p->sub_socket, command, len);
\r
1100 if (p->state == 3) {
\r
1103 * version number (1 bytes) = 5
\r
1104 * reply code (1 byte)
\r
1106 * 1 = general SOCKS server failure
\r
1107 * 2 = connection not allowed by ruleset
\r
1108 * 3 = network unreachable
\r
1109 * 4 = host unreachable
\r
1110 * 5 = connection refused
\r
1112 * 7 = command not supported
\r
1113 * 8 = address type not supported
\r
1114 * reserved (1 byte) = x00
\r
1115 * address type (1 byte)
\r
1117 * 3 = domainname (first byte has length, no terminating null)
\r
1119 * server bound address (variable)
\r
1120 * server bound port (2 bytes) [network order]
\r
1125 /* First 5 bytes of packet are enough to tell its length. */
\r
1126 if (bufchain_size(&p->pending_input_data) < 5)
\r
1127 return 1; /* not got anything yet */
\r
1129 /* get the response */
\r
1130 bufchain_fetch(&p->pending_input_data, data, 5);
\r
1132 if (data[0] != 5) {
\r
1133 plug_closing(p->plug, "Proxy error: SOCKS proxy returned wrong version number",
\r
1134 PROXY_ERROR_GENERAL, 0);
\r
1138 if (data[1] != 0) {
\r
1141 strcpy(buf, "Proxy error: ");
\r
1143 switch (data[1]) {
\r
1144 case 1: strcat(buf, "General SOCKS server failure"); break;
\r
1145 case 2: strcat(buf, "Connection not allowed by ruleset"); break;
\r
1146 case 3: strcat(buf, "Network unreachable"); break;
\r
1147 case 4: strcat(buf, "Host unreachable"); break;
\r
1148 case 5: strcat(buf, "Connection refused"); break;
\r
1149 case 6: strcat(buf, "TTL expired"); break;
\r
1150 case 7: strcat(buf, "Command not supported"); break;
\r
1151 case 8: strcat(buf, "Address type not supported"); break;
\r
1152 default: sprintf(buf+strlen(buf),
\r
1153 "Unrecognised SOCKS error code %d",
\r
1157 plug_closing(p->plug, buf, PROXY_ERROR_GENERAL, 0);
\r
1163 * Eat the rest of the reply packet.
\r
1165 len = 6; /* first 4 bytes, last 2 */
\r
1166 switch (data[3]) {
\r
1167 case 1: len += 4; break; /* IPv4 address */
\r
1168 case 4: len += 16; break;/* IPv6 address */
\r
1169 case 3: len += (unsigned char)data[4]; break; /* domain name */
\r
1171 plug_closing(p->plug, "Proxy error: SOCKS proxy returned "
\r
1172 "unrecognised address format",
\r
1173 PROXY_ERROR_GENERAL, 0);
\r
1176 if (bufchain_size(&p->pending_input_data) < len)
\r
1177 return 1; /* not got whole reply yet */
\r
1178 bufchain_consume(&p->pending_input_data, len);
\r
1181 proxy_activate(p);
\r
1185 if (p->state == 4) {
\r
1186 /* TODO: Handle GSSAPI authentication */
\r
1187 plug_closing(p->plug, "Proxy error: We don't support GSSAPI authentication",
\r
1188 PROXY_ERROR_GENERAL, 0);
\r
1192 if (p->state == 5) {
\r
1193 char *username = conf_get_str(p->conf, CONF_proxy_username);
\r
1194 char *password = conf_get_str(p->conf, CONF_proxy_password);
\r
1195 if (username[0] || password[0]) {
\r
1196 char userpwbuf[255 + 255 + 3];
\r
1198 ulen = strlen(username);
\r
1199 if (ulen > 255) ulen = 255; if (ulen < 1) ulen = 1;
\r
1200 plen = strlen(password);
\r
1201 if (plen > 255) plen = 255; if (plen < 1) plen = 1;
\r
1202 userpwbuf[0] = 1; /* version number of subnegotiation */
\r
1203 userpwbuf[1] = ulen;
\r
1204 memcpy(userpwbuf+2, username, ulen);
\r
1205 userpwbuf[ulen+2] = plen;
\r
1206 memcpy(userpwbuf+ulen+3, password, plen);
\r
1207 sk_write(p->sub_socket, userpwbuf, ulen + plen + 3);
\r
1210 plug_closing(p->plug, "Proxy error: Server chose "
\r
1211 "username/password authentication but we "
\r
1212 "didn't offer it!",
\r
1213 PROXY_ERROR_GENERAL, 0);
\r
1217 if (p->state == 6) {
\r
1219 ret = proxy_socks5_selectchap(p);
\r
1220 if (ret) return ret;
\r
1225 plug_closing(p->plug, "Proxy error: Unexpected proxy error",
\r
1226 PROXY_ERROR_UNEXPECTED, 0);
\r
1230 /* ----------------------------------------------------------------------
\r
1231 * `Telnet' proxy type.
\r
1233 * (This is for ad-hoc proxies where you connect to the proxy's
\r
1234 * telnet port and send a command such as `connect host port'. The
\r
1235 * command is configurable, since this proxy type is typically not
\r
1236 * standardised or at all well-defined.)
\r
1239 char *format_telnet_command(SockAddr addr, int port, Conf *conf)
\r
1241 char *fmt = conf_get_str(conf, CONF_proxy_telnet_command);
\r
1243 int retlen = 0, retsize = 0;
\r
1244 int so = 0, eo = 0;
\r
1245 #define ENSURE(n) do { \
\r
1246 if (retsize < retlen + n) { \
\r
1247 retsize = retlen + n + 512; \
\r
1248 ret = sresize(ret, retsize, char); \
\r
1252 /* we need to escape \\, \%, \r, \n, \t, \x??, \0???,
\r
1253 * %%, %host, %port, %user, and %pass
\r
1256 while (fmt[eo] != 0) {
\r
1258 /* scan forward until we hit end-of-line,
\r
1259 * or an escape character (\ or %) */
\r
1260 while (fmt[eo] != 0 && fmt[eo] != '%' && fmt[eo] != '\\')
\r
1263 /* if we hit eol, break out of our escaping loop */
\r
1264 if (fmt[eo] == 0) break;
\r
1266 /* if there was any unescaped text before the escape
\r
1267 * character, send that now */
\r
1270 memcpy(ret + retlen, fmt + so, eo - so);
\r
1271 retlen += eo - so;
\r
1276 /* if the escape character was the last character of
\r
1277 * the line, we'll just stop and send it. */
\r
1278 if (fmt[eo] == 0) break;
\r
1280 if (fmt[so] == '\\') {
\r
1282 /* we recognize \\, \%, \r, \n, \t, \x??.
\r
1283 * anything else, we just send unescaped (including the \).
\r
1286 switch (fmt[eo]) {
\r
1290 ret[retlen++] = '\\';
\r
1296 ret[retlen++] = '%';
\r
1302 ret[retlen++] = '\r';
\r
1308 ret[retlen++] = '\n';
\r
1314 ret[retlen++] = '\t';
\r
1321 /* escaped hexadecimal value (ie. \xff) */
\r
1322 unsigned char v = 0;
\r
1327 if (fmt[eo] >= '0' && fmt[eo] <= '9')
\r
1328 v += fmt[eo] - '0';
\r
1329 else if (fmt[eo] >= 'a' && fmt[eo] <= 'f')
\r
1330 v += fmt[eo] - 'a' + 10;
\r
1331 else if (fmt[eo] >= 'A' && fmt[eo] <= 'F')
\r
1332 v += fmt[eo] - 'A' + 10;
\r
1334 /* non hex character, so we abort and just
\r
1335 * send the whole thing unescaped (including \x)
\r
1338 ret[retlen++] = '\\';
\r
1343 /* we only extract two hex characters */
\r
1346 ret[retlen++] = v;
\r
1359 memcpy(ret+retlen, fmt + so, 2);
\r
1366 /* % escape. we recognize %%, %host, %port, %user, %pass.
\r
1367 * %proxyhost, %proxyport. Anything else we just send
\r
1368 * unescaped (including the %).
\r
1371 if (fmt[eo] == '%') {
\r
1373 ret[retlen++] = '%';
\r
1376 else if (strnicmp(fmt + eo, "host", 4) == 0) {
\r
1379 sk_getaddr(addr, dest, lenof(dest));
\r
1380 destlen = strlen(dest);
\r
1382 memcpy(ret+retlen, dest, destlen);
\r
1383 retlen += destlen;
\r
1386 else if (strnicmp(fmt + eo, "port", 4) == 0) {
\r
1387 char portstr[8], portlen;
\r
1388 portlen = sprintf(portstr, "%i", port);
\r
1390 memcpy(ret + retlen, portstr, portlen);
\r
1391 retlen += portlen;
\r
1394 else if (strnicmp(fmt + eo, "user", 4) == 0) {
\r
1395 char *username = conf_get_str(conf, CONF_proxy_username);
\r
1396 int userlen = strlen(username);
\r
1398 memcpy(ret+retlen, username, userlen);
\r
1399 retlen += userlen;
\r
1402 else if (strnicmp(fmt + eo, "pass", 4) == 0) {
\r
1403 char *password = conf_get_str(conf, CONF_proxy_password);
\r
1404 int passlen = strlen(password);
\r
1406 memcpy(ret+retlen, password, passlen);
\r
1407 retlen += passlen;
\r
1410 else if (strnicmp(fmt + eo, "proxyhost", 9) == 0) {
\r
1411 char *host = conf_get_str(conf, CONF_proxy_host);
\r
1412 int phlen = strlen(host);
\r
1414 memcpy(ret+retlen, host, phlen);
\r
1418 else if (strnicmp(fmt + eo, "proxyport", 9) == 0) {
\r
1419 int port = conf_get_int(conf, CONF_proxy_port);
\r
1422 sprintf(pport, "%d", port);
\r
1423 pplen = strlen(pport);
\r
1425 memcpy(ret+retlen, pport, pplen);
\r
1430 /* we don't escape this, so send the % now, and
\r
1431 * don't advance eo, so that we'll consider the
\r
1432 * text immediately following the % as unescaped.
\r
1435 ret[retlen++] = '%';
\r
1439 /* resume scanning for additional escapes after this one. */
\r
1443 /* if there is any unescaped text at the end of the line, send it */
\r
1446 memcpy(ret + retlen, fmt + so, eo - so);
\r
1447 retlen += eo - so;
\r
1451 ret[retlen] = '\0';
\r
1457 int proxy_telnet_negotiate (Proxy_Socket p, int change)
\r
1459 if (p->state == PROXY_CHANGE_NEW) {
\r
1460 char *formatted_cmd;
\r
1462 formatted_cmd = format_telnet_command(p->remote_addr, p->remote_port,
\r
1465 sk_write(p->sub_socket, formatted_cmd, strlen(formatted_cmd));
\r
1466 sfree(formatted_cmd);
\r
1472 if (change == PROXY_CHANGE_CLOSING) {
\r
1473 /* if our proxy negotiation process involves closing and opening
\r
1474 * new sockets, then we would want to intercept this closing
\r
1475 * callback when we were expecting it. if we aren't anticipating
\r
1476 * a socket close, then some error must have occurred. we'll
\r
1477 * just pass those errors up to the backend.
\r
1479 return plug_closing(p->plug, p->closing_error_msg,
\r
1480 p->closing_error_code,
\r
1481 p->closing_calling_back);
\r
1484 if (change == PROXY_CHANGE_SENT) {
\r
1485 /* some (or all) of what we wrote to the proxy was sent.
\r
1486 * we don't do anything new, however, until we receive the
\r
1487 * proxy's response. we might want to set a timer so we can
\r
1488 * timeout the proxy negotiation after a while...
\r
1493 if (change == PROXY_CHANGE_ACCEPTING) {
\r
1494 /* we should _never_ see this, as we are using our socket to
\r
1495 * connect to a proxy, not accepting inbound connections.
\r
1496 * what should we do? close the socket with an appropriate
\r
1499 return plug_accepting(p->plug, p->accepting_sock);
\r
1502 if (change == PROXY_CHANGE_RECEIVE) {
\r
1503 /* we have received data from the underlying socket, which
\r
1504 * we'll need to parse, process, and respond to appropriately.
\r
1508 proxy_activate(p);
\r
1509 /* proxy activate will have dealt with
\r
1510 * whatever is left of the buffer */
\r
1514 plug_closing(p->plug, "Proxy error: Unexpected proxy error",
\r
1515 PROXY_ERROR_UNEXPECTED, 0);
\r