/* meta.c -- handle the meta communication Copyright (C) 2000-2012 Guus Sliepen , 2000-2005 Ivo Timmermans 2006 Scott Lamb This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ #include "system.h" #include "cipher.h" #include "connection.h" #include "logger.h" #include "meta.h" #include "net.h" #include "protocol.h" #include "utils.h" #include "xalloc.h" bool send_meta_sptps(void *handle, uint8_t type, const char *buffer, size_t length) { connection_t *c = handle; if(!c) { logger(DEBUG_ALWAYS, LOG_ERR, "send_meta_sptps() called with NULL pointer!"); abort(); } buffer_add(&c->outbuf, buffer, length); io_set(&c->io, IO_READ | IO_WRITE); return true; } bool send_meta(connection_t *c, const char *buffer, int length) { if(!c) { logger(DEBUG_ALWAYS, LOG_ERR, "send_meta() called with NULL pointer!"); abort(); } logger(DEBUG_META, LOG_DEBUG, "Sending %d bytes of metadata to %s (%s)", length, c->name, c->hostname); if(c->protocol_minor >= 2) return sptps_send_record(&c->sptps, 0, buffer, length); /* Add our data to buffer */ if(c->status.encryptout) { size_t outlen = length; if(!cipher_encrypt(&c->outcipher, buffer, length, buffer_prepare(&c->outbuf, length), &outlen, false) || outlen != length) { logger(DEBUG_ALWAYS, LOG_ERR, "Error while encrypting metadata to %s (%s)", c->name, c->hostname); return false; } } else { buffer_add(&c->outbuf, buffer, length); } io_set(&c->io, IO_READ | IO_WRITE); return true; } void broadcast_meta(connection_t *from, const char *buffer, int length) { for list_each(connection_t, c, connection_list) if(c != from && c->status.active) send_meta(c, buffer, length); } bool receive_meta_sptps(void *handle, uint8_t type, const char *data, uint16_t length) { connection_t *c = handle; if(!c) { logger(DEBUG_ALWAYS, LOG_ERR, "receive_meta_sptps() called with NULL pointer!"); abort(); } if(type == SPTPS_HANDSHAKE) { if(c->allow_request == ACK) return send_ack(c); else return true; } if(!data) return true; /* Are we receiving a TCPpacket? */ if(c->tcplen) { if(length != c->tcplen) return false; receive_tcppacket(c, data, length); c->tcplen = 0; return true; } /* Change newline to null byte, just like non-SPTPS requests */ if(data[length - 1] == '\n') ((char *)data)[length - 1] = 0; /* Otherwise we are waiting for a request */ return receive_request(c, data); } bool receive_meta(connection_t *c) { int inlen; char inbuf[MAXBUFSIZE]; char *bufp = inbuf, *endp; /* Strategy: - Read as much as possible from the TCP socket in one go. - Decrypt it. - Check if a full request is in the input buffer. - If yes, process request and remove it from the buffer, then check again. - If not, keep stuff in buffer and exit. */ buffer_compact(&c->inbuf, MAXBUFSIZE); if(sizeof inbuf <= c->inbuf.len) { logger(DEBUG_ALWAYS, LOG_ERR, "Input buffer full for %s (%s)", c->name, c->hostname); return false; } inlen = recv(c->socket, inbuf, sizeof inbuf - c->inbuf.len, 0); if(inlen <= 0) { if(!inlen || !errno) { logger(DEBUG_CONNECTIONS, LOG_NOTICE, "Connection closed by %s (%s)", c->name, c->hostname); } else if(sockwouldblock(sockerrno)) return true; else logger(DEBUG_ALWAYS, LOG_ERR, "Metadata socket read error for %s (%s): %s", c->name, c->hostname, sockstrerror(sockerrno)); return false; } do { if(c->protocol_minor >= 2) return sptps_receive_data(&c->sptps, bufp, inlen); if(!c->status.decryptin) { endp = memchr(bufp, '\n', inlen); if(endp) endp++; else endp = bufp + inlen; buffer_add(&c->inbuf, bufp, endp - bufp); inlen -= endp - bufp; bufp = endp; } else { size_t outlen = inlen; if(!cipher_decrypt(&c->incipher, bufp, inlen, buffer_prepare(&c->inbuf, inlen), &outlen, false) || inlen != outlen) { logger(DEBUG_ALWAYS, LOG_ERR, "Error while decrypting metadata from %s (%s)", c->name, c->hostname); return false; } inlen = 0; } while(c->inbuf.len) { /* Are we receiving a TCPpacket? */ if(c->tcplen) { char *tcpbuffer = buffer_read(&c->inbuf, c->tcplen); if(!tcpbuffer) break; if(!c->node) { if(c->outgoing && proxytype == PROXY_SOCKS4 && c->allow_request == ID) { if(tcpbuffer[0] == 0 && tcpbuffer[1] == 0x5a) { logger(DEBUG_CONNECTIONS, LOG_DEBUG, "Proxy request granted"); } else { logger(DEBUG_CONNECTIONS, LOG_ERR, "Proxy request rejected"); return false; } } else if(c->outgoing && proxytype == PROXY_SOCKS5 && c->allow_request == ID) { if(tcpbuffer[0] != 5) { logger(DEBUG_CONNECTIONS, LOG_ERR, "Invalid response from proxy server"); return false; } if(tcpbuffer[1] == (char)0xff) { logger(DEBUG_CONNECTIONS, LOG_ERR, "Proxy request rejected: unsuitable authentication method"); return false; } if(tcpbuffer[2] != 5) { logger(DEBUG_CONNECTIONS, LOG_ERR, "Invalid response from proxy server"); return false; } if(tcpbuffer[3] == 0) { logger(DEBUG_CONNECTIONS, LOG_DEBUG, "Proxy request granted"); } else { logger(DEBUG_CONNECTIONS, LOG_DEBUG, "Proxy request rejected"); return false; } } else { logger(DEBUG_CONNECTIONS, LOG_ERR, "c->tcplen set but c->node is NULL!"); abort(); } } else { if(c->allow_request == ALL) { receive_tcppacket(c, tcpbuffer, c->tcplen); } else { logger(DEBUG_CONNECTIONS, LOG_ERR, "Got unauthorized TCP packet from %s (%s)", c->name, c->hostname); return false; } } c->tcplen = 0; } /* Otherwise we are waiting for a request */ char *request = buffer_readline(&c->inbuf); if(request) { bool result = receive_request(c, request); if(!result) return false; continue; } else { break; } } } while(inlen); return true; }