tinc-vpn.org Git - tinc/blob - src/meta.c

   1 /*
   2     meta.c -- handle the meta communication
   3     Copyright (C) 2000-2009 Guus Sliepen <guus@tinc-vpn.org>,
   4                   2000-2005 Ivo Timmermans
   5                   2006      Scott Lamb <slamb@slamb.org>
   6
   7     This program is free software; you can redistribute it and/or modify
   8     it under the terms of the GNU General Public License as published by
   9     the Free Software Foundation; either version 2 of the License, or
  10     (at your option) any later version.
  11
  12     This program is distributed in the hope that it will be useful,
  13     but WITHOUT ANY WARRANTY; without even the implied warranty of
  14     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15     GNU General Public License for more details.
  16
  17     You should have received a copy of the GNU General Public License along
  18     with this program; if not, write to the Free Software Foundation, Inc.,
  19     51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  20 */
  21
  22 #include "system.h"
  23
  24 #include "cipher.h"
  25 #include "connection.h"
  26 #include "logger.h"
  27 #include "meta.h"
  28 #include "net.h"
  29 #include "protocol.h"
  30 #include "utils.h"
  31 #include "xalloc.h"
  32
  33 bool send_meta_sptps(void *handle, uint8_t type, const char *buffer, size_t length) {
  34         connection_t *c = handle;
  35
  36         if(!c) {
  37                 logger(DEBUG_ALWAYS, LOG_ERR, "send_meta_sptps() called with NULL pointer!");
  38                 abort();
  39         }
  40
  41         buffer_add(&c->outbuf, buffer, length);
  42         event_add(&c->outevent, NULL);
  43
  44         return true;
  45 }
  46
  47 bool send_meta(connection_t *c, const char *buffer, int length) {
  48         if(!c) {
  49                 logger(DEBUG_ALWAYS, LOG_ERR, "send_meta() called with NULL pointer!");
  50                 abort();
  51         }
  52
  53         logger(DEBUG_META, LOG_DEBUG, "Sending %d bytes of metadata to %s (%s)", length,
  54                            c->name, c->hostname);
  55
  56         if(c->protocol_minor >= 2)
  57                 return sptps_send_record(&c->sptps, 0, buffer, length);
  58
  59         /* Add our data to buffer */
  60         if(c->status.encryptout) {
  61                 size_t outlen = length;
  62
  63                 if(!cipher_encrypt(&c->outcipher, buffer, length, buffer_prepare(&c->outbuf, length), &outlen, false) || outlen != length) {
  64                         logger(DEBUG_ALWAYS, LOG_ERR, "Error while encrypting metadata to %s (%s)",
  65                                         c->name, c->hostname);
  66                         return false;
  67                 }
  68
  69         } else {
  70                 buffer_add(&c->outbuf, buffer, length);
  71         }
  72
  73         event_add(&c->outevent, NULL);
  74
  75         return true;
  76 }
  77
  78 void broadcast_meta(connection_t *from, const char *buffer, int length) {
  79         for list_each(connection_t, c, connection_list)
  80                 if(c != from && c->status.active)
  81                         send_meta(c, buffer, length);
  82 }
  83
  84 bool receive_meta_sptps(void *handle, uint8_t type, const char *data, uint16_t length) {
  85         connection_t *c = handle;
  86
  87         if(!c) {
  88                 logger(DEBUG_ALWAYS, LOG_ERR, "receive_meta_sptps() called with NULL pointer!");
  89                 abort();
  90         }
  91
  92         if(type == SPTPS_HANDSHAKE) {
  93                 if(c->allow_request == ACK)
  94                         return send_ack(c);
  95                 else
  96                         return true;
  97         }
  98
  99         if(!data)
 100                 return true;
 101
 102         /* Are we receiving a TCPpacket? */
 103
 104         if(c->tcplen) {
 105                 if(length != c->tcplen)
 106                         return false;
 107                 receive_tcppacket(c, data, length);
 108                 c->tcplen = 0;
 109                 return true;
 110         }
 111
 112         /* Otherwise we are waiting for a request */
 113
 114         return receive_request(c, data);
 115 }
 116
 117 bool receive_meta(connection_t *c) {
 118         int inlen;
 119         char inbuf[MAXBUFSIZE];
 120         char *bufp = inbuf, *endp;
 121
 122         /* Strategy:
 123            - Read as much as possible from the TCP socket in one go.
 124            - Decrypt it.
 125            - Check if a full request is in the input buffer.
 126            - If yes, process request and remove it from the buffer,
 127            then check again.
 128            - If not, keep stuff in buffer and exit.
 129          */
 130
 131         buffer_compact(&c->inbuf, MAXBUFSIZE);
 132
 133         if(sizeof inbuf <= c->inbuf.len) {
 134                 logger(DEBUG_ALWAYS, LOG_ERR, "Input buffer full for %s (%s)", c->name, c->hostname);
 135                 return false;
 136         }
 137
 138         inlen = recv(c->socket, inbuf, sizeof inbuf - c->inbuf.len, 0);
 139
 140         if(inlen <= 0) {
 141                 if(!inlen || !errno) {
 142                         logger(DEBUG_CONNECTIONS, LOG_NOTICE, "Connection closed by %s (%s)",
 143                                            c->name, c->hostname);
 144                 } else if(sockwouldblock(sockerrno))
 145                         return true;
 146                 else
 147                         logger(DEBUG_ALWAYS, LOG_ERR, "Metadata socket read error for %s (%s): %s",
 148                                    c->name, c->hostname, sockstrerror(sockerrno));
 149                 return false;
 150         }
 151
 152         do {
 153                 if(c->protocol_minor >= 2)
 154                         return sptps_receive_data(&c->sptps, bufp, inlen);
 155
 156                 if(!c->status.decryptin) {
 157                         endp = memchr(bufp, '\n', inlen);
 158                         if(endp)
 159                                 endp++;
 160                         else
 161                                 endp = bufp + inlen;
 162
 163                         buffer_add(&c->inbuf, bufp, endp - bufp);
 164
 165                         inlen -= endp - bufp;
 166                         bufp = endp;
 167                 } else {
 168                         size_t outlen = inlen;
 169
 170                         if(!cipher_decrypt(&c->incipher, bufp, inlen, buffer_prepare(&c->inbuf, inlen), &outlen, false) || inlen != outlen) {
 171                                 logger(DEBUG_ALWAYS, LOG_ERR, "Error while decrypting metadata from %s (%s)",
 172                                            c->name, c->hostname);
 173                                 return false;
 174                         }
 175
 176                         inlen = 0;
 177                 }
 178
 179                 while(c->inbuf.len) {
 180                         /* Are we receiving a TCPpacket? */
 181
 182                         if(c->tcplen) {
 183                                 char *tcpbuffer = buffer_read(&c->inbuf, c->tcplen);
 184                                 if(tcpbuffer) {
 185                                         if(proxytype == PROXY_SOCKS4 && c->allow_request == ID) {
 186                                                 if(tcpbuffer[0] == 0 && tcpbuffer[1] == 0x5a) {
 187                                                         logger(DEBUG_CONNECTIONS, LOG_DEBUG, "Proxy request granted");
 188                                                 } else {
 189                                                         logger(DEBUG_CONNECTIONS, LOG_ERR, "Proxy request rejected");
 190                                                         return false;
 191                                                 }
 192                                         } else
 193                                                 receive_tcppacket(c, tcpbuffer, c->tcplen);
 194                                         c->tcplen = 0;
 195                                         continue;
 196                                 } else {
 197                                         break;
 198                                 }
 199                         }
 200
 201                         /* Otherwise we are waiting for a request */
 202
 203                         char *request = buffer_readline(&c->inbuf);
 204                         if(request) {
 205                                 bool result = receive_request(c, request);
 206                                 if(!result)
 207                                         return false;
 208                                 continue;
 209                         } else {
 210                                 break;
 211                         }
 212                 }
 213         } while(inlen);
 214
 215         return true;
 216 }