Add basic support for SOCKS 4 and HTTP CONNECT proxies.
[oweals/tinc.git] / src / meta.c
index 8d6b0a84f561fd5d073b0e1391550bcb7af43052..1b3424606771b813aa3a15c096a8ad751eaafbcc 100644 (file)
@@ -1,7 +1,8 @@
 /*
     meta.c -- handle the meta communication
-    Copyright (C) 2000-2002 Guus Sliepen <guus@sliepen.eu.org>,
-                  2000-2002 Ivo Timmermans <ivo@o2w.nl>
+    Copyright (C) 2000-2009 Guus Sliepen <guus@tinc-vpn.org>,
+                  2000-2005 Ivo Timmermans
+                  2006      Scott Lamb <slamb@slamb.org>
 
     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
     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., 675 Mass Ave, Cambridge, MA 02139, USA.
-
-    $Id: meta.c,v 1.1.2.26 2002/06/21 10:11:12 guus Exp $
+    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 "config.h"
-#include <utils.h>
-#include <avl_tree.h>
-
-#include <errno.h>
-#include <syslog.h>
-#include <unistd.h>
-#include <string.h>
-/* This line must be below the rest for FreeBSD */
-#include <sys/types.h>
-#include <sys/socket.h>
+#include "system.h"
 
+#include <openssl/err.h>
 #include <openssl/evp.h>
 
-#include "net.h"
+#include "avl_tree.h"
 #include "connection.h"
-#include "system.h"
+#include "logger.h"
+#include "meta.h"
+#include "net.h"
 #include "protocol.h"
+#include "utils.h"
+#include "xalloc.h"
+
+bool send_meta(connection_t *c, const char *buffer, int length) {
+       int outlen;
+       int result;
+
+       if(!c) {
+               logger(LOG_ERR, "send_meta() called with NULL pointer!");
+               abort();
+       }
+
+       ifdebug(META) logger(LOG_DEBUG, "Sending %d bytes of metadata to %s (%s)", length,
+                          c->name, c->hostname);
+
+       if(!c->outbuflen)
+               c->last_flushed_time = now;
+
+       /* Find room in connection's buffer */
+       if(length + c->outbuflen > c->outbufsize) {
+               c->outbufsize = length + c->outbuflen;
+               c->outbuf = xrealloc(c->outbuf, c->outbufsize);
+       }
+
+       if(length + c->outbuflen + c->outbufstart > c->outbufsize) {
+               memmove(c->outbuf, c->outbuf + c->outbufstart, c->outbuflen);
+               c->outbufstart = 0;
+       }
+
+       /* Add our data to buffer */
+       if(c->status.encryptout) {
+               result = EVP_EncryptUpdate(c->outctx, (unsigned char *)c->outbuf + c->outbufstart + c->outbuflen,
+                               &outlen, (unsigned char *)buffer, length);
+               if(!result || outlen < length) {
+                       logger(LOG_ERR, "Error while encrypting metadata to %s (%s): %s",
+                                       c->name, c->hostname, ERR_error_string(ERR_get_error(), NULL));
+                       return false;
+               } else if(outlen > length) {
+                       logger(LOG_EMERG, "Encrypted data too long! Heap corrupted!");
+                       abort();
+               }
+               c->outbuflen += outlen;
+       } else {
+               memcpy(c->outbuf + c->outbufstart + c->outbuflen, buffer, length);
+               c->outbuflen += length;
+       }
+
+       return true;
+}
 
-int send_meta(connection_t *c, char *buffer, int length)
-{
-  char *bufp;
-  int outlen;
-  char outbuf[MAXBUFSIZE];
-cp
-  if(debug_lvl >= DEBUG_META)
-    syslog(LOG_DEBUG, _("Sending %d bytes of metadata to %s (%s)"), length,
-           c->name, c->hostname);
-
-  if(c->status.encryptout)
-    {
-      EVP_EncryptUpdate(c->outctx, outbuf, &outlen, buffer, length);
-      bufp = outbuf;
-      length = outlen;
-    }
-  else
-      bufp = buffer;
-
-  if(write(c->socket, bufp, length) < 0)
-    {
-      syslog(LOG_ERR, _("Sending meta data to %s (%s) failed: %s"), c->name, c->hostname, strerror(errno));
-      return -1;
-    }
-cp
-  return 0;
+bool flush_meta(connection_t *c) {
+       int result;
+       
+       ifdebug(META) logger(LOG_DEBUG, "Flushing %d bytes to %s (%s)",
+                        c->outbuflen, c->name, c->hostname);
+
+       while(c->outbuflen) {
+               result = send(c->socket, c->outbuf + c->outbufstart, c->outbuflen, 0);
+               if(result <= 0) {
+                       if(!errno || errno == EPIPE) {
+                               ifdebug(CONNECTIONS) logger(LOG_NOTICE, "Connection closed by %s (%s)",
+                                                  c->name, c->hostname);
+                       } else if(errno == EINTR) {
+                               continue;
+                       } else if(sockwouldblock(sockerrno)) {
+                               ifdebug(CONNECTIONS) logger(LOG_DEBUG, "Flushing %d bytes to %s (%s) would block",
+                                               c->outbuflen, c->name, c->hostname);
+                               return true;
+                       } else {
+                               logger(LOG_ERR, "Flushing meta data to %s (%s) failed: %s", c->name,
+                                          c->hostname, sockstrerror(sockerrno));
+                       }
+
+                       return false;
+               }
+
+               c->outbufstart += result;
+               c->outbuflen -= result;
+       }
+
+       c->outbufstart = 0; /* avoid unnecessary memmoves */
+       return true;
 }
 
-void broadcast_meta(connection_t *from, char *buffer, int length)
-{
-  avl_node_t *node;
-  connection_t *c;
-cp
-  for(node = connection_tree->head; node; node = node->next)
-    {
-      c = (connection_t *)node->data;
-      if(c != from && c->status.active)
-        send_meta(c, buffer, length);
-    }
-cp
+void broadcast_meta(connection_t *from, const char *buffer, int length) {
+       avl_node_t *node;
+       connection_t *c;
+
+       for(node = connection_tree->head; node; node = node->next) {
+               c = node->data;
+
+               if(c != from && c->status.active)
+                       send_meta(c, buffer, length);
+       }
 }
 
-int receive_meta(connection_t *c)
-{
-  int x, l = sizeof(x);
-  int oldlen, i;
-  int lenin, reqlen;
-  int decrypted = 0;
-  char inbuf[MAXBUFSIZE];
-cp
-  if(getsockopt(c->socket, SOL_SOCKET, SO_ERROR, &x, &l) < 0)
-    {
-      syslog(LOG_ERR, _("This is a bug: %s:%d: %d:%s %s (%s)"), __FILE__, __LINE__, c->socket, strerror(errno),
-             c->name, c->hostname);
-      return -1;
-    }
-  if(x)
-    {
-      syslog(LOG_ERR, _("Metadata socket error for %s (%s): %s"),
-             c->name, c->hostname, strerror(x));
-      return -1;
-    }
-
-  /* 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.
-   */
-
-  lenin = read(c->socket, c->buffer + c->buflen, MAXBUFSIZE - c->buflen);
-
-  if(lenin<=0)
-    {
-      if(lenin==0)
-        {
-          if(debug_lvl >= DEBUG_CONNECTIONS)
-            syslog(LOG_NOTICE, _("Connection closed by %s (%s)"),
-                c->name, c->hostname);
-        }
-      else
-        if(errno==EINTR)
-          return 0;      
-        else
-          syslog(LOG_ERR, _("Metadata socket read error for %s (%s): %s"),
-                 c->name, c->hostname, strerror(errno));
-
-      return -1;
-    }
-
-  oldlen = c->buflen;
-  c->buflen += lenin;
-
-  while(lenin)
-    {
-      /* Decrypt */
-
-      if(c->status.decryptin && !decrypted)
-        {
-          EVP_DecryptUpdate(c->inctx, inbuf, &lenin, c->buffer + oldlen, lenin);
-          memcpy(c->buffer + oldlen, inbuf, lenin);
-          decrypted = 1;
-        }
-
-      /* Are we receiving a TCPpacket? */
-
-      if(c->tcplen)
-        {
-          if(c->tcplen <= c->buflen)
-            {
-              receive_tcppacket(c, c->buffer, c->tcplen);
-
-              c->buflen -= c->tcplen;
-              lenin -= c->tcplen;
-              memmove(c->buffer, c->buffer + c->tcplen, c->buflen);
-              oldlen = 0;
-              c->tcplen = 0;
-              continue;
-            }
-          else
-            {
-              break;
-            }
-        }
-
-      /* Otherwise we are waiting for a request */
-
-      reqlen = 0;
-
-      for(i = oldlen; i < c->buflen; i++)
-        {
-          if(c->buffer[i] == '\n')
-            {
-              c->buffer[i] = '\0';  /* replace end-of-line by end-of-string so we can use sscanf */
-              reqlen = i + 1;
-              break;
-            }
-        }
-
-      if(reqlen)
-        {
-          if(receive_request(c))
-            return -1;
-
-          c->buflen -= reqlen;
-          lenin -= reqlen;
-          memmove(c->buffer, c->buffer + reqlen, c->buflen);
-          oldlen = 0;
-          continue;
-        }
-      else
-        {
-          break;
-        }
-    }
-
-  if(c->buflen >= MAXBUFSIZE)
-    {
-      syslog(LOG_ERR, _("Metadata read buffer overflow for %s (%s)"),
-            c->name, c->hostname);
-      return -1;
-    }
-
-  c->last_ping_time = now;
-cp  
-  return 0;
+bool receive_meta(connection_t *c) {
+       int oldlen, i, result;
+       int lenin, lenout, reqlen;
+       bool decrypted = false;
+       char inbuf[MAXBUFSIZE];
+
+       /* 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.
+        */
+
+       lenin = recv(c->socket, c->buffer + c->buflen, MAXBUFSIZE - c->buflen, 0);
+
+       if(lenin <= 0) {
+               if(!lenin || !errno) {
+                       ifdebug(CONNECTIONS) logger(LOG_NOTICE, "Connection closed by %s (%s)",
+                                          c->name, c->hostname);
+               } else if(sockwouldblock(sockerrno))
+                       return true;
+               else
+                       logger(LOG_ERR, "Metadata socket read error for %s (%s): %s",
+                                  c->name, c->hostname, sockstrerror(sockerrno));
+
+               return false;
+       }
+
+       oldlen = c->buflen;
+       c->buflen += lenin;
+
+       while(lenin > 0) {
+               /* Decrypt */
+
+               if(c->status.decryptin && !decrypted) {
+                       result = EVP_DecryptUpdate(c->inctx, (unsigned char *)inbuf, &lenout, (unsigned char *)c->buffer + oldlen, lenin);
+                       if(!result || lenout != lenin) {
+                               logger(LOG_ERR, "Error while decrypting metadata from %s (%s): %s",
+                                               c->name, c->hostname, ERR_error_string(ERR_get_error(), NULL));
+                               return false;
+                       }
+                       memcpy(c->buffer + oldlen, inbuf, lenin);
+                       decrypted = true;
+               }
+
+               /* Are we receiving a TCPpacket? */
+
+               if(c->tcplen) {
+                       if(c->tcplen <= c->buflen) {
+                               if(proxytype == PROXY_SOCKS4 && c->allow_request == ID) {
+                                       if(c->buffer[0] == 0 && c->buffer[1] == 0x5a) {
+                                               logger(LOG_DEBUG, "Proxy request granted");
+                                       } else {
+                                               logger(LOG_ERR, "Proxy request rejected");
+                                               return false;
+                                       }
+                               } else 
+                                       receive_tcppacket(c, c->buffer, c->tcplen);
+
+                               c->buflen -= c->tcplen;
+                               lenin -= c->tcplen - oldlen;
+                               memmove(c->buffer, c->buffer + c->tcplen, c->buflen);
+                               oldlen = 0;
+                               c->tcplen = 0;
+                               continue;
+                       } else {
+                               break;
+                       }
+               }
+
+               /* Otherwise we are waiting for a request */
+
+               reqlen = 0;
+
+               for(i = oldlen; i < c->buflen; i++) {
+                       if(c->buffer[i] == '\n') {
+                               c->buffer[i] = '\0';    /* replace end-of-line by end-of-string so we can use sscanf */
+                               reqlen = i + 1;
+                               break;
+                       }
+               }
+
+               if(reqlen) {
+                       c->reqlen = reqlen;
+                       if(!receive_request(c))
+                               return false;
+
+                       c->buflen -= reqlen;
+                       lenin -= reqlen - oldlen;
+                       memmove(c->buffer, c->buffer + reqlen, c->buflen);
+                       oldlen = 0;
+                       continue;
+               } else {
+                       break;
+               }
+       }
+
+       if(c->buflen >= MAXBUFSIZE) {
+               logger(LOG_ERR, "Metadata read buffer overflow for %s (%s)",
+                          c->name, c->hostname);
+               return false;
+       }
+
+       return true;
 }