/*************************************************************************** * _ _ ____ _ * Project ___| | | | _ \| | * / __| | | | |_) | | * | (__| |_| | _ <| |___ * \___|\___/|_| \_\_____| * * Copyright (C) 1998 - 2007, Daniel Stenberg, , et al. * * This software is licensed as described in the file COPYING, which * you should have received as part of this distribution. The terms * are also available at http://curl.haxx.se/docs/copyright.html. * * You may opt to use, copy, modify, merge, publish, distribute and/or sell * copies of the Software, and permit persons to whom the Software is * furnished to do so, under the terms of the COPYING file. * * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY * KIND, either express or implied. * * $Id: socks.c,v 1.14 2007-06-05 13:42:23 bagder Exp $ ***************************************************************************/ #include "setup.h" #include #ifdef NEED_MALLOC_H #include #endif #ifdef HAVE_STDLIB_H #include #endif #ifdef HAVE_SYS_SOCKET_H #include #endif #ifdef HAVE_NETINET_IN_H #include #endif #ifdef HAVE_ARPA_INET_H #include #endif #include "urldata.h" #include "sendf.h" #include "strequal.h" #include "select.h" #include "connect.h" #include "timeval.h" #include "socks.h" /* The last #include file should be: */ #include "memdebug.h" /* * Helper read-from-socket functions. Does the same as Curl_read() but it * blocks until all bytes amount of buffersize will be read. No more, no less. * * This is STUPID BLOCKING behaviour which we frown upon, but right now this * is what we have... */ static int blockread_all(struct connectdata *conn, /* connection data */ curl_socket_t sockfd, /* read from this socket */ char *buf, /* store read data here */ ssize_t buffersize, /* max amount to read */ ssize_t *n, /* amount bytes read */ long conn_timeout) /* timeout for data wait relative to conn->created */ { ssize_t nread; ssize_t allread = 0; int result; struct timeval tvnow; long conntime; *n = 0; do { tvnow = Curl_tvnow(); /* calculating how long connection is establishing */ conntime = Curl_tvdiff(tvnow, conn->created); if(conntime > conn_timeout) { /* we already got the timeout */ result = ~CURLE_OK; break; } if(Curl_socket_ready(sockfd, CURL_SOCKET_BAD, (int)(conn_timeout - conntime)) <= 0) { result = ~CURLE_OK; break; } result = Curl_read(conn, sockfd, buf, buffersize, &nread); if(result) break; if(buffersize == nread) { allread += nread; *n = allread; result = CURLE_OK; break; } if(!nread) { result = ~CURLE_OK; break; } buffersize -= nread; buf += nread; allread += nread; } while(1); return result; } /* * This function logs in to a SOCKS4 proxy and sends the specifics to the final * destination server. * * Reference : * http://socks.permeo.com/protocol/socks4.protocol * * Note : * Nonsupport "SOCKS 4A (Simple Extension to SOCKS 4 Protocol)" * Nonsupport "Identification Protocol (RFC1413)" */ CURLcode Curl_SOCKS4(const char *proxy_name, char *hostname, int remote_port, int sockindex, struct connectdata *conn) { unsigned char socksreq[262]; /* room for SOCKS4 request incl. user id */ int result; CURLcode code; curl_socket_t sock = conn->sock[sockindex]; long timeout; struct SessionHandle *data = conn->data; /* get timeout */ if(data->set.timeout && data->set.connecttimeout) { if (data->set.timeout < data->set.connecttimeout) timeout = data->set.timeout; else timeout = data->set.connecttimeout; } else if(data->set.timeout) timeout = data->set.timeout; else if(data->set.connecttimeout) timeout = data->set.connecttimeout; else timeout = DEFAULT_CONNECT_TIMEOUT; Curl_nonblock(sock, FALSE); /* * Compose socks4 request * * Request format * * +----+----+----+----+----+----+----+----+----+----+....+----+ * | VN | CD | DSTPORT | DSTIP | USERID |NULL| * +----+----+----+----+----+----+----+----+----+----+....+----+ * # of bytes: 1 1 2 4 variable 1 */ socksreq[0] = 4; /* version (SOCKS4) */ socksreq[1] = 1; /* connect */ *((unsigned short*)&socksreq[2]) = htons((unsigned short)remote_port); /* DNS resolve */ { struct Curl_dns_entry *dns; Curl_addrinfo *hp=NULL; int rc; rc = Curl_resolv(conn, hostname, remote_port, &dns); if(rc == CURLRESOLV_ERROR) return CURLE_COULDNT_RESOLVE_PROXY; if(rc == CURLRESOLV_PENDING) /* this requires that we're in "wait for resolve" state */ rc = Curl_wait_for_resolv(conn, &dns); /* * We cannot use 'hostent' as a struct that Curl_resolv() returns. It * returns a Curl_addrinfo pointer that may not always look the same. */ if(dns) hp=dns->addr; if (hp) { char buf[64]; unsigned short ip[4]; Curl_printable_address(hp, buf, sizeof(buf)); if(4 == sscanf( buf, "%hu.%hu.%hu.%hu", &ip[0], &ip[1], &ip[2], &ip[3])) { /* Set DSTIP */ socksreq[4] = (unsigned char)ip[0]; socksreq[5] = (unsigned char)ip[1]; socksreq[6] = (unsigned char)ip[2]; socksreq[7] = (unsigned char)ip[3]; } else hp = NULL; /* fail! */ Curl_resolv_unlock(data, dns); /* not used anymore from now on */ } if(!hp) { failf(data, "Failed to resolve \"%s\" for SOCKS4 connect.", hostname); return CURLE_COULDNT_RESOLVE_HOST; } } /* * This is currently not supporting "Identification Protocol (RFC1413)". */ socksreq[8] = 0; /* ensure empty userid is NUL-terminated */ if (proxy_name) strlcat((char*)socksreq + 8, proxy_name, sizeof(socksreq) - 8); /* * Make connection */ { ssize_t actualread; ssize_t written; int packetsize = 9 + (int)strlen((char*)socksreq + 8); /* size including NUL */ /* Send request */ code = Curl_write(conn, sock, (char *)socksreq, packetsize, &written); if ((code != CURLE_OK) || (written != packetsize)) { failf(data, "Failed to send SOCKS4 connect request."); return CURLE_COULDNT_CONNECT; } packetsize = 8; /* receive data size */ /* Receive response */ result = blockread_all(conn, sock, (char *)socksreq, packetsize, &actualread, timeout); if ((result != CURLE_OK) || (actualread != packetsize)) { failf(data, "Failed to receive SOCKS4 connect request ack."); return CURLE_COULDNT_CONNECT; } /* * Response format * * +----+----+----+----+----+----+----+----+ * | VN | CD | DSTPORT | DSTIP | * +----+----+----+----+----+----+----+----+ * # of bytes: 1 1 2 4 * * VN is the version of the reply code and should be 0. CD is the result * code with one of the following values: * * 90: request granted * 91: request rejected or failed * 92: request rejected because SOCKS server cannot connect to * identd on the client * 93: request rejected because the client program and identd * report different user-ids */ /* wrong version ? */ if (socksreq[0] != 0) { failf(data, "SOCKS4 reply has wrong version, version should be 4."); return CURLE_COULDNT_CONNECT; } /* Result */ switch(socksreq[1]) { case 90: infof(data, "SOCKS4 request granted.\n"); break; case 91: failf(data, "Can't complete SOCKS4 connection to %d.%d.%d.%d:%d. (%d)" ", request rejected or failed.", (unsigned char)socksreq[4], (unsigned char)socksreq[5], (unsigned char)socksreq[6], (unsigned char)socksreq[7], (unsigned int)ntohs(*(unsigned short*)(&socksreq[8])), socksreq[1]); return CURLE_COULDNT_CONNECT; case 92: failf(data, "Can't complete SOCKS4 connection to %d.%d.%d.%d:%d. (%d)" ", request rejected because SOCKS server cannot connect to " "identd on the client.", (unsigned char)socksreq[4], (unsigned char)socksreq[5], (unsigned char)socksreq[6], (unsigned char)socksreq[7], (unsigned int)ntohs(*(unsigned short*)(&socksreq[8])), socksreq[1]); return CURLE_COULDNT_CONNECT; case 93: failf(data, "Can't complete SOCKS4 connection to %d.%d.%d.%d:%d. (%d)" ", request rejected because the client program and identd " "report different user-ids.", (unsigned char)socksreq[4], (unsigned char)socksreq[5], (unsigned char)socksreq[6], (unsigned char)socksreq[7], (unsigned int)ntohs(*(unsigned short*)(&socksreq[8])), socksreq[1]); return CURLE_COULDNT_CONNECT; default: failf(data, "Can't complete SOCKS4 connection to %d.%d.%d.%d:%d. (%d)" ", Unknown.", (unsigned char)socksreq[4], (unsigned char)socksreq[5], (unsigned char)socksreq[6], (unsigned char)socksreq[7], (unsigned int)ntohs(*(unsigned short*)(&socksreq[8])), socksreq[1]); return CURLE_COULDNT_CONNECT; } } Curl_nonblock(sock, TRUE); return CURLE_OK; /* Proxy was successful! */ } /* * This function logs in to a SOCKS5 proxy and sends the specifics to the final * destination server. */ CURLcode Curl_SOCKS5(const char *proxy_name, const char *proxy_password, char *hostname, int remote_port, int sockindex, struct connectdata *conn) { /* According to the RFC1928, section "6. Replies". This is what a SOCK5 replies: +----+-----+-------+------+----------+----------+ |VER | REP | RSV | ATYP | BND.ADDR | BND.PORT | +----+-----+-------+------+----------+----------+ | 1 | 1 | X'00' | 1 | Variable | 2 | +----+-----+-------+------+----------+----------+ Where: o VER protocol version: X'05' o REP Reply field: o X'00' succeeded */ unsigned char socksreq[600]; /* room for large user/pw (255 max each) */ ssize_t actualread; ssize_t written; int result; CURLcode code; curl_socket_t sock = conn->sock[sockindex]; struct SessionHandle *data = conn->data; long timeout; /* get timeout */ if(data->set.timeout && data->set.connecttimeout) { if (data->set.timeout < data->set.connecttimeout) timeout = data->set.timeout; else timeout = data->set.connecttimeout; } else if(data->set.timeout) timeout = data->set.timeout; else if(data->set.connecttimeout) timeout = data->set.connecttimeout; else timeout = DEFAULT_CONNECT_TIMEOUT; Curl_nonblock(sock, TRUE); /* wait until socket gets connected */ result = Curl_socket_ready(CURL_SOCKET_BAD, sock, (int)timeout); if(-1 == result) { failf(conn->data, "SOCKS5: no connection here"); return CURLE_COULDNT_CONNECT; } else if(0 == result) { failf(conn->data, "SOCKS5: connection timeout"); return CURLE_OPERATION_TIMEDOUT; } if(result & CURL_CSELECT_ERR) { failf(conn->data, "SOCKS5: error occured during connection"); return CURLE_COULDNT_CONNECT; } socksreq[0] = 5; /* version */ socksreq[1] = (char)(proxy_name ? 2 : 1); /* number of methods (below) */ socksreq[2] = 0; /* no authentication */ socksreq[3] = 2; /* username/password */ Curl_nonblock(sock, FALSE); code = Curl_write(conn, sock, (char *)socksreq, (2 + (int)socksreq[1]), &written); if ((code != CURLE_OK) || (written != (2 + (int)socksreq[1]))) { failf(data, "Unable to send initial SOCKS5 request."); return CURLE_COULDNT_CONNECT; } Curl_nonblock(sock, TRUE); result = Curl_socket_ready(sock, CURL_SOCKET_BAD, (int)timeout); if(-1 == result) { failf(conn->data, "SOCKS5 nothing to read"); return CURLE_COULDNT_CONNECT; } else if(0 == result) { failf(conn->data, "SOCKS5 read timeout"); return CURLE_OPERATION_TIMEDOUT; } if(result & CURL_CSELECT_ERR) { failf(conn->data, "SOCKS5 read error occured"); return CURLE_RECV_ERROR; } Curl_nonblock(sock, FALSE); result=blockread_all(conn, sock, (char *)socksreq, 2, &actualread, timeout); if ((result != CURLE_OK) || (actualread != 2)) { failf(data, "Unable to receive initial SOCKS5 response."); return CURLE_COULDNT_CONNECT; } if (socksreq[0] != 5) { failf(data, "Received invalid version in initial SOCKS5 response."); return CURLE_COULDNT_CONNECT; } if (socksreq[1] == 0) { /* Nothing to do, no authentication needed */ ; } else if (socksreq[1] == 2) { /* Needs user name and password */ size_t userlen, pwlen; int len; if(proxy_name && proxy_password) { userlen = strlen(proxy_name); pwlen = strlen(proxy_password); } else { userlen = 0; pwlen = 0; } /* username/password request looks like * +----+------+----------+------+----------+ * |VER | ULEN | UNAME | PLEN | PASSWD | * +----+------+----------+------+----------+ * | 1 | 1 | 1 to 255 | 1 | 1 to 255 | * +----+------+----------+------+----------+ */ len = 0; socksreq[len++] = 1; /* username/pw subnegotiation version */ socksreq[len++] = (char) userlen; memcpy(socksreq + len, proxy_name, (int) userlen); len += userlen; socksreq[len++] = (char) pwlen; memcpy(socksreq + len, proxy_password, (int) pwlen); len += pwlen; code = Curl_write(conn, sock, (char *)socksreq, len, &written); if ((code != CURLE_OK) || (len != written)) { failf(data, "Failed to send SOCKS5 sub-negotiation request."); return CURLE_COULDNT_CONNECT; } result=blockread_all(conn, sock, (char *)socksreq, 2, &actualread, timeout); if ((result != CURLE_OK) || (actualread != 2)) { failf(data, "Unable to receive SOCKS5 sub-negotiation response."); return CURLE_COULDNT_CONNECT; } /* ignore the first (VER) byte */ if (socksreq[1] != 0) { /* status */ failf(data, "User was rejected by the SOCKS5 server (%d %d).", socksreq[0], socksreq[1]); return CURLE_COULDNT_CONNECT; } /* Everything is good so far, user was authenticated! */ } else { /* error */ if (socksreq[1] == 1) { failf(data, "SOCKS5 GSSAPI per-message authentication is not supported."); return CURLE_COULDNT_CONNECT; } else if (socksreq[1] == 255) { if (!proxy_name || !*proxy_name) { failf(data, "No authentication method was acceptable. (It is quite likely" " that the SOCKS5 server wanted a username/password, since none" " was supplied to the server on this connection.)"); } else { failf(data, "No authentication method was acceptable."); } return CURLE_COULDNT_CONNECT; } else { failf(data, "Undocumented SOCKS5 mode attempted to be used by server."); return CURLE_COULDNT_CONNECT; } } /* Authentication is complete, now specify destination to the proxy */ socksreq[0] = 5; /* version (SOCKS5) */ socksreq[1] = 1; /* connect */ socksreq[2] = 0; /* must be zero */ socksreq[3] = 1; /* IPv4 = 1 */ { struct Curl_dns_entry *dns; Curl_addrinfo *hp=NULL; int rc = Curl_resolv(conn, hostname, remote_port, &dns); if(rc == CURLRESOLV_ERROR) return CURLE_COULDNT_RESOLVE_HOST; if(rc == CURLRESOLV_PENDING) /* this requires that we're in "wait for resolve" state */ rc = Curl_wait_for_resolv(conn, &dns); /* * We cannot use 'hostent' as a struct that Curl_resolv() returns. It * returns a Curl_addrinfo pointer that may not always look the same. */ if(dns) hp=dns->addr; if (hp) { char buf[64]; unsigned short ip[4]; Curl_printable_address(hp, buf, sizeof(buf)); if(4 == sscanf( buf, "%hu.%hu.%hu.%hu", &ip[0], &ip[1], &ip[2], &ip[3])) { socksreq[4] = (unsigned char)ip[0]; socksreq[5] = (unsigned char)ip[1]; socksreq[6] = (unsigned char)ip[2]; socksreq[7] = (unsigned char)ip[3]; } else hp = NULL; /* fail! */ Curl_resolv_unlock(data, dns); /* not used anymore from now on */ } if(!hp) { failf(data, "Failed to resolve \"%s\" for SOCKS5 connect.", hostname); return CURLE_COULDNT_RESOLVE_HOST; } } *((unsigned short*)&socksreq[8]) = htons((unsigned short)remote_port); { const int packetsize = 10; code = Curl_write(conn, sock, (char *)socksreq, packetsize, &written); if ((code != CURLE_OK) || (written != packetsize)) { failf(data, "Failed to send SOCKS5 connect request."); return CURLE_COULDNT_CONNECT; } result = blockread_all(conn, sock, (char *)socksreq, packetsize, &actualread, timeout); if ((result != CURLE_OK) || (actualread != packetsize)) { failf(data, "Failed to receive SOCKS5 connect request ack."); return CURLE_COULDNT_CONNECT; } if (socksreq[0] != 5) { /* version */ failf(data, "SOCKS5 reply has wrong version, version should be 5."); return CURLE_COULDNT_CONNECT; } if (socksreq[1] != 0) { /* Anything besides 0 is an error */ failf(data, "Can't complete SOCKS5 connection to %d.%d.%d.%d:%d. (%d)", (unsigned char)socksreq[4], (unsigned char)socksreq[5], (unsigned char)socksreq[6], (unsigned char)socksreq[7], (unsigned int)ntohs(*(unsigned short*)(&socksreq[8])), socksreq[1]); return CURLE_COULDNT_CONNECT; } } Curl_nonblock(sock, TRUE); return CURLE_OK; /* Proxy was successful! */ }