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