Fixed a race condition triggered by receive_meta() and the new

[tinc] / src / meta.c

diff --git a/src/meta.c b/src/meta.c
index 31a387a..ecf875c 100644 (file)
--- a/src/meta.c
+++ b/src/meta.c
@@ -1,7 +1,7 @@
 /*
     meta.c -- handle the meta communication
-    Copyright (C) 2000 Guus Sliepen <guus@sliepen.warande.net>,
-                  2000 Ivo Timmermans <itimmermans@bigfoot.com>
+    Copyright (C) 2000,2001 Guus Sliepen <guus@sliepen.warande.net>,
+                  2000,2001 Ivo Timmermans <itimmermans@bigfoot.com>
 
     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
@@ -17,22 +17,33 @@
     along with this program; if not, write to the Free Software
     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 
-    $Id: meta.c,v 1.1.2.5 2000/10/21 11:52:06 guus Exp $
+    $Id: meta.c,v 1.1.2.16 2001/03/12 23:58:19 guus Exp $
 */
 
 #include "config.h"
 #include <utils.h>
+#include <avl_tree.h>
 
 #include <errno.h>
 #include <syslog.h>
 #include <sys/signal.h>
+#include <unistd.h>
+#include <string.h>
+/* This line must be below the rest for FreeBSD */
 #include <sys/socket.h>
-#include <openssl/evp.h>
+
+#ifdef HAVE_OPENSSL_EVP_H
+# include <openssl/evp.h>
+#else
+# include <evp.h>
+#endif
 
 #include "net.h"
+#include "connection.h"
 #include "system.h"
+#include "protocol.h"
 
-int send_meta(conn_list_t *cl, char *buffer, int length)
+int send_meta(connection_t *cl, char *buffer, int length)
 {
   char outbuf[MAXBUFSIZE];
   char *bufp;
@@ -43,14 +54,15 @@ cp
            cl->name, cl->hostname, buffer);
 
   buffer[length-1]='\n';
-  
+
   if(cl->status.encryptout)
     {
       EVP_EncryptUpdate(cl->cipher_outctx, outbuf, &outlen, buffer, length);
       bufp = outbuf;
+      length = outlen;
     }
   else
-    bufp = buffer;
+      bufp = buffer;
 
   if(write(cl->meta_socket, bufp, length) < 0)
     {
@@ -61,24 +73,28 @@ cp
   return 0;
 }
 
-int broadcast_meta(conn_list_t *cl, char *buffer, int length)
+void broadcast_meta(connection_t *cl, char *buffer, int length)
 {
-  conn_list_t *p;
+  avl_node_t *node;
+  connection_t *p;
 cp
-  for(p = conn_list; p != NULL; p = p->next)
-    if(p != cl && p->status.meta && p->status.active)
-      send_meta(p, buffer, length);
+  for(node = connection_tree->head; node; node = node->next)
+    {
+      p = (connection_t *)node->data;
+      if(p != cl && p->status.meta && p->status.active)
+        send_meta(p, buffer, length);
+    }
 cp
-  return 0;
 }
 
-int receive_meta(conn_list_t *cl)
+int receive_meta(connection_t *cl)
 {
   int x, l = sizeof(x);
   int oldlen, i;
   int lenin = 0;
   char inbuf[MAXBUFSIZE];
   char *bufp;
+  int decrypted = 0;
 cp
   if(getsockopt(cl->meta_socket, SOL_SOCKET, SO_ERROR, &x, &l) < 0)
     {
@@ -93,39 +109,38 @@ cp
       return -1;
     }
 
-  if(cl->status.decryptin)
-    bufp = inbuf;
-  else
-    bufp = cl->buffer + cl->buflen;
-
-  lenin = read(cl->meta_socket, bufp, MAXBUFSIZE - cl->buflen);
+  lenin = read(cl->meta_socket, cl->buffer + cl->buflen, MAXBUFSIZE - cl->buflen);
 
   if(lenin<=0)
     {
-      if(errno==EINTR)
-        return 0;      
-      if(errno==0)
+      if(lenin==0)
         {
           if(debug_lvl >= DEBUG_CONNECTIONS)
             syslog(LOG_NOTICE, _("Connection closed by %s (%s)"),
                 cl->name, cl->hostname);
         }
       else
-        syslog(LOG_ERR, _("Metadata socket read error for %s (%s): %m"),
-               cl->name, cl->hostname);
+        if(errno==EINTR)
+          return 0;      
+        else
+          syslog(LOG_ERR, _("Metadata socket read error for %s (%s): %m"),
+                 cl->name, cl->hostname);
+
       return -1;
     }
 
-  if(cl->status.decryptin)
-    {
-      EVP_DecryptUpdate(cl->cipher_inctx, cl->buffer + cl->buflen, NULL, inbuf, lenin);
-    }
-    
   oldlen = cl->buflen;
   cl->buflen += lenin;
 
-  for(;;)
+  while(lenin)
     {
+      if(cl->status.decryptin && !decrypted)
+        {
+          EVP_DecryptUpdate(cl->cipher_inctx, inbuf, &lenin, cl->buffer + oldlen, lenin);
+          memcpy(cl->buffer + oldlen, inbuf, lenin);
+          decrypted = 1;
+        }
+
       cl->reqlen = 0;
 
       for(i = oldlen; i < cl->buflen; i++)
@@ -140,7 +155,7 @@ cp
 
       if(cl->reqlen)
         {
-          if(debug_lvl >= DEBUG_PROTOCOL)
+          if(debug_lvl >= DEBUG_META)
             syslog(LOG_DEBUG, _("Got request from %s (%s): %s"),
                   cl->name, cl->hostname, cl->buffer);
 
@@ -148,6 +163,7 @@ cp
             return -1;
 
           cl->buflen -= cl->reqlen;
+          lenin -= cl->reqlen;
           memmove(cl->buffer, cl->buffer + cl->reqlen, cl->buflen);
           oldlen = 0;
         }
@@ -165,7 +181,6 @@ cp
     }
 
   cl->last_ping_time = time(NULL);
-  cl->want_ping = 0;
 cp  
   return 0;
 }