Use MTU probes to regularly ping other nodes over UDP.
[tinc] / src / meta.c
index c2fbd7e..21400f2 100644 (file)
@@ -1,7 +1,8 @@
 /*
     meta.c -- handle the meta communication
-    Copyright (C) 2000-2003 Guus Sliepen <guus@sliepen.eu.org>,
-                  2000-2003 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 1.1.2.40 2003/08/08 22:11:54 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 "system.h"
 
+#include <openssl/err.h>
 #include <openssl/evp.h>
 
 #include "avl_tree.h"
 #include "connection.h"
 #include "logger.h"
+#include "meta.h"
 #include "net.h"
 #include "protocol.h"
-#include "system.h"
 #include "utils.h"
+#include "xalloc.h"
 
-bool send_meta(connection_t *c, char *buffer, int length)
-{
-       char *bufp;
+bool send_meta(connection_t *c, const char *buffer, int length) {
        int outlen;
-       char outbuf[MAXBUFSIZE];
        int result;
 
-       cp();
+       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,
+       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) {
-               EVP_EncryptUpdate(c->outctx, outbuf, &outlen, buffer, length);
-               bufp = outbuf;
-               length = outlen;
-       } else
-               bufp = buffer;
-
-       while(length) {
-               result = send(c->socket, bufp, length, 0);
+               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;
+}
+
+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)"),
+                               ifdebug(CONNECTIONS) logger(LOG_NOTICE, "Connection closed by %s (%s)",
                                                   c->name, c->hostname);
-                       } else if(errno == EINTR)
+                       } else if(errno == EINTR) {
                                continue;
-                       else
-                               logger(LOG_ERR, _("Sending meta data to %s (%s) failed: %s"), c->name,
+#ifdef EWOULDBLOCK
+                       } else if(errno == EWOULDBLOCK) {
+                               ifdebug(CONNECTIONS) logger(LOG_DEBUG, "Flushing %d bytes to %s (%s) would block",
+                                               c->outbuflen, c->name, c->hostname);
+                               return true;
+#endif
+                       } else {
+                               logger(LOG_ERR, "Flushing meta data to %s (%s) failed: %s", c->name,
                                           c->hostname, strerror(errno));
+                       }
+
                        return false;
                }
-               bufp += result;
-               length -= result;
+
+               c->outbufstart += result;
+               c->outbuflen -= result;
        }
-       
+
+       c->outbufstart = 0; /* avoid unnecessary memmoves */
        return true;
 }
 
-void broadcast_meta(connection_t *from, char *buffer, int length)
-{
+void broadcast_meta(connection_t *from, const 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;
+               c = node->data;
 
                if(c != from && c->status.active)
                        send_meta(c, buffer, length);
        }
 }
 
-bool receive_meta(connection_t *c)
-{
-       int x;
-       socklen_t l = sizeof(x);
-       int oldlen, i;
-       int lenin, reqlen;
+bool receive_meta(connection_t *c) {
+       int oldlen, i, result;
+       int lenin, lenout, reqlen;
        bool decrypted = false;
        char inbuf[MAXBUFSIZE];
 
-       cp();
-
-       if(getsockopt(c->socket, SOL_SOCKET, SO_ERROR, &x, &l) < 0) {
-               logger(LOG_ERR, _("This is a bug: %s:%d: %d:%s %s (%s)"), __FILE__,
-                          __LINE__, c->socket, strerror(errno), c->name, c->hostname);
-               return false;
-       }
-
-       if(x) {
-               logger(LOG_ERR, _("Metadata socket error for %s (%s): %s"),
-                          c->name, c->hostname, strerror(x));
-               return false;
-       }
-
        /* Strategy:
           - Read as much as possible from the TCP socket in one go.
           - Decrypt it.
@@ -122,12 +147,12 @@ bool receive_meta(connection_t *c)
 
        if(lenin <= 0) {
                if(!lenin || !errno) {
-                       ifdebug(CONNECTIONS) logger(LOG_NOTICE, _("Connection closed by %s (%s)"),
+                       ifdebug(CONNECTIONS) logger(LOG_NOTICE, "Connection closed by %s (%s)",
                                           c->name, c->hostname);
                } else if(errno == EINTR)
                        return true;
                else
-                       logger(LOG_ERR, _("Metadata socket read error for %s (%s): %s"),
+                       logger(LOG_ERR, "Metadata socket read error for %s (%s): %s",
                                   c->name, c->hostname, strerror(errno));
 
                return false;
@@ -136,11 +161,16 @@ bool receive_meta(connection_t *c)
        oldlen = c->buflen;
        c->buflen += lenin;
 
-       while(lenin) {
+       while(lenin > 0) {
                /* Decrypt */
 
                if(c->status.decryptin && !decrypted) {
-                       EVP_DecryptUpdate(c->inctx, inbuf, &lenin, c->buffer + oldlen, lenin);
+                       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;
                }
@@ -152,7 +182,7 @@ bool receive_meta(connection_t *c)
                                receive_tcppacket(c, c->buffer, c->tcplen);
 
                                c->buflen -= c->tcplen;
-                               lenin -= c->tcplen;
+                               lenin -= c->tcplen - oldlen;
                                memmove(c->buffer, c->buffer + c->tcplen, c->buflen);
                                oldlen = 0;
                                c->tcplen = 0;
@@ -180,7 +210,7 @@ bool receive_meta(connection_t *c)
                                return false;
 
                        c->buflen -= reqlen;
-                       lenin -= reqlen;
+                       lenin -= reqlen - oldlen;
                        memmove(c->buffer, c->buffer + reqlen, c->buflen);
                        oldlen = 0;
                        continue;
@@ -190,12 +220,10 @@ bool receive_meta(connection_t *c)
        }
 
        if(c->buflen >= MAXBUFSIZE) {
-               logger(LOG_ERR, _("Metadata read buffer overflow for %s (%s)"),
+               logger(LOG_ERR, "Metadata read buffer overflow for %s (%s)",
                           c->name, c->hostname);
                return false;
        }
 
-       c->last_ping_time = now;
-
        return true;
 }