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 "splay_tree.h"
  25 #include "cipher.h"
  26 #include "connection.h"
  27 #include "logger.h"
  28 #include "meta.h"
  29 #include "net.h"
  30 #include "protocol.h"
  31 #include "utils.h"
  32 #include "xalloc.h"
  33
  34 bool send_meta_sptps(void *handle, uint8_t type, const char *buffer, size_t length) {
  35         connection_t *c = handle;
  36
  37         if(!c) {
  38                 logger(DEBUG_ALWAYS, LOG_ERR, "send_meta_sptps() called with NULL pointer!");
  39                 abort();
  40         }
  41
  42         buffer_add(&c->outbuf, buffer, length);
  43         event_add(&c->outevent, NULL);
  44
  45         return true;
  46 }
  47
  48 bool send_meta(connection_t *c, const char *buffer, int length) {
  49         if(!c) {
  50                 logger(DEBUG_ALWAYS, LOG_ERR, "send_meta() called with NULL pointer!");
  51                 abort();
  52         }
  53
  54         logger(DEBUG_META, LOG_DEBUG, "Sending %d bytes of metadata to %s (%s)", length,
  55                            c->name, c->hostname);
  56
  57         if(c->protocol_minor >= 2)
  58                 return sptps_send_record(&c->sptps, 0, buffer, length);
  59
  60         /* Add our data to buffer */
  61         if(c->status.encryptout) {
  62                 size_t outlen = length;
  63
  64                 if(!cipher_encrypt(&c->outcipher, buffer, length, buffer_prepare(&c->outbuf, length), &outlen, false) || outlen != length) {
  65                         logger(DEBUG_ALWAYS, LOG_ERR, "Error while encrypting metadata to %s (%s)",
  66                                         c->name, c->hostname);
  67                         return false;
  68                 }
  69
  70         } else {
  71                 buffer_add(&c->outbuf, buffer, length);
  72         }
  73
  74         event_add(&c->outevent, NULL);
  75
  76         return true;
  77 }
  78
  79 void broadcast_meta(connection_t *from, const char *buffer, int length) {
  80         splay_node_t *node;
  81         connection_t *c;
  82
  83         for(node = connection_tree->head; node; node = node->next) {
  84                 c = node->data;
  85
  86                 if(c != from && c->status.active)
  87                         send_meta(c, buffer, length);
  88         }
  89 }
  90
  91 bool receive_meta_sptps(void *handle, uint8_t type, const char *data, uint16_t length) {
  92         connection_t *c = handle;
  93
  94         if(!c) {
  95                 logger(DEBUG_ALWAYS, LOG_ERR, "receive_meta_sptps() called with NULL pointer!");
  96                 abort();
  97         }
  98
  99         if(type == SPTPS_HANDSHAKE) {
 100                 if(c->allow_request == ACK)
 101                         return send_ack(c);
 102                 else
 103                         return true;
 104         }
 105
 106         if(!data)
 107                 return true;
 108
 109         /* Are we receiving a TCPpacket? */
 110
 111         if(c->tcplen) {
 112                 if(length != c->tcplen)
 113                         return false;
 114                 receive_tcppacket(c, data, length);
 115                 c->tcplen = 0;
 116                 return true;
 117         }
 118
 119         /* Otherwise we are waiting for a request */
 120
 121         return receive_request(c, data);
 122 }
 123
 124 bool receive_meta(connection_t *c) {
 125         int inlen;
 126         char inbuf[MAXBUFSIZE];
 127         char *bufp = inbuf, *endp;
 128
 129         /* Strategy:
 130            - Read as much as possible from the TCP socket in one go.
 131            - Decrypt it.
 132            - Check if a full request is in the input buffer.
 133            - If yes, process request and remove it from the buffer,
 134            then check again.
 135            - If not, keep stuff in buffer and exit.
 136          */
 137
 138         buffer_compact(&c->inbuf, MAXBUFSIZE);
 139
 140         if(sizeof inbuf <= c->inbuf.len) {
 141                 logger(DEBUG_ALWAYS, LOG_ERR, "Input buffer full for %s (%s)", c->name, c->hostname);
 142                 return false;
 143         }
 144
 145         inlen = recv(c->socket, inbuf, sizeof inbuf - c->inbuf.len, 0);
 146
 147         if(inlen <= 0) {
 148                 if(!inlen || !errno) {
 149                         logger(DEBUG_CONNECTIONS, LOG_NOTICE, "Connection closed by %s (%s)",
 150                                            c->name, c->hostname);
 151                 } else if(sockwouldblock(sockerrno))
 152                         return true;
 153                 else
 154                         logger(DEBUG_ALWAYS, LOG_ERR, "Metadata socket read error for %s (%s): %s",
 155                                    c->name, c->hostname, sockstrerror(sockerrno));
 156                 return false;
 157         }
 158
 159         do {
 160                 if(c->protocol_minor >= 2)
 161                         return sptps_receive_data(&c->sptps, bufp, inlen);
 162
 163                 if(!c->status.decryptin) {
 164                         endp = memchr(bufp, '\n', inlen);
 165                         if(endp)
 166                                 endp++;
 167                         else
 168                                 endp = bufp + inlen;
 169
 170                         buffer_add(&c->inbuf, bufp, endp - bufp);
 171
 172                         inlen -= endp - bufp;
 173                         bufp = endp;
 174                 } else {
 175                         size_t outlen = inlen;
 176
 177                         if(!cipher_decrypt(&c->incipher, bufp, inlen, buffer_prepare(&c->inbuf, inlen), &outlen, false) || inlen != outlen) {
 178                                 logger(DEBUG_ALWAYS, LOG_ERR, "Error while decrypting metadata from %s (%s)",
 179                                            c->name, c->hostname);
 180                                 return false;
 181                         }
 182
 183                         inlen = 0;
 184                 }
 185
 186                 while(c->inbuf.len) {
 187                         /* Are we receiving a TCPpacket? */
 188
 189                         if(c->tcplen) {
 190                                 char *tcpbuffer = buffer_read(&c->inbuf, c->tcplen);
 191                                 if(tcpbuffer) {
 192                                         if(proxytype == PROXY_SOCKS4 && c->allow_request == ID) {
 193                                                 if(tcpbuffer[0] == 0 && tcpbuffer[1] == 0x5a) {
 194                                                         logger(DEBUG_CONNECTIONS, LOG_DEBUG, "Proxy request granted");
 195                                                 } else {
 196                                                         logger(DEBUG_CONNECTIONS, LOG_ERR, "Proxy request rejected");
 197                                                         return false;
 198                                                 }
 199                                         } else
 200                                                 receive_tcppacket(c, tcpbuffer, c->tcplen);
 201                                         c->tcplen = 0;
 202                                         continue;
 203                                 } else {
 204                                         break;
 205                                 }
 206                         }
 207
 208                         /* Otherwise we are waiting for a request */
 209
 210                         char *request = buffer_readline(&c->inbuf);
 211                         if(request) {
 212                                 bool result = receive_request(c, request);
 213                                 if(!result)
 214                                         return false;
 215                                 continue;
 216                         } else {
 217                                 break;
 218                         }
 219                 }
 220         } while(inlen);
 221
 222         return true;
 223 }