From 61e71ab74ad9b5edb044b84ccf1111a33eb468cb Mon Sep 17 00:00:00 2001
From: Guus Sliepen <guus@tinc-vpn.org>
Date: Sat, 27 May 2000 20:23:01 +0000
Subject: [PATCH] Terminate a connection on any error. Furthermore, disallow
 del_host, add_host and other important requests until remote host has
 properly authenticated itself.

---
 src/net.c      | 15 ++++++++++-----
 src/protocol.c |  9 +++++++++
 2 files changed, 19 insertions(+), 5 deletions(-)

diff --git a/src/net.c b/src/net.c
index 3c884782..9daf8c81 100644
--- a/src/net.c
+++ b/src/net.c
@@ -935,8 +935,8 @@ cp
 
   if(cl->buflen >= MAXBUFSIZE)
     {
-      syslog(LOG_ERR, "Metadata read buffer full! Discarding contents.");
-      cl->buflen = 0;
+      syslog(LOG_ERR, "Metadata read buffer overflow.");
+      return -1;
     }
 
   lenin = read(cl->meta_socket, cl->buffer, MAXBUFSIZE-cl->buflen);
@@ -971,17 +971,22 @@ cp
               if(request_handlers[request] == NULL)
                 {
                   syslog(LOG_ERR, "Unknown request: %s", cl->buffer);
-                  return 0;
+                  return -1;
                 }
 
               if(debug_lvl > 3)
                 syslog(LOG_DEBUG, "Got request: %s", cl->buffer);                             
 
-              request_handlers[request](cl);
+              if(request_handlers[request](cl))  /* Something went wrong. Probably scriptkiddies. Terminate. */
+                {
+                  syslog(LOG_ERR, "Error while processing request from IP_ADDR_S", IP_ADDR_V(cl->real_ip));
+                  return -1;
+                }
             }
           else
             {
-              syslog(LOG_ERR, "Bogus data received: %s", cl->buffer);
+              syslog(LOG_ERR, "Bogus data received.");
+              return -1;
             }
 
           cl->buflen -= cl->reqlen;
diff --git a/src/protocol.c b/src/protocol.c
index 51d95e9d..2691bb07 100644
--- a/src/protocol.c
+++ b/src/protocol.c
@@ -490,6 +490,7 @@ cp
 int timeout_h(conn_list_t *cl)
 {
 cp
+  if(!cl->status.active) return -1;
   syslog(LOG_NOTICE, IP_ADDR_S " says it's gotten a timeout from us", IP_ADDR_V(cl->vpn_ip));
   cl->status.termreq = 1;
   terminate_connection(cl);
@@ -502,6 +503,8 @@ int del_host_h(conn_list_t *cl)
   ip_t vpn_ip;
   conn_list_t *fw;
 cp
+  if(!cl->status.active) return -1;
+
   if(sscanf(cl->buffer, "%*d %lx", &vpn_ip) != 1)
     {
        syslog(LOG_ERR, "got bad DEL_HOST request: %s", cl->buffer);
@@ -530,6 +533,7 @@ cp
 int ping_h(conn_list_t *cl)
 {
 cp
+  if(!cl->status.active) return -1;
   if(debug_lvl > 3)
     syslog(LOG_DEBUG, "responding to ping from " IP_ADDR_S, IP_ADDR_V(cl->vpn_ip));
   cl->status.pinged = 0;
@@ -543,6 +547,7 @@ cp
 int pong_h(conn_list_t *cl)
 {
 cp
+  if(!cl->status.active) return -1;
   if(debug_lvl > 3)
     syslog(LOG_DEBUG, "ok, got pong from " IP_ADDR_S, IP_ADDR_V(cl->vpn_ip));
   cl->status.got_pong = 1;
@@ -558,6 +563,7 @@ int add_host_h(conn_list_t *cl)
   unsigned short port;
   conn_list_t *ncn, *fw;
 cp
+  if(!cl->status.active) return -1;
   if(sscanf(cl->buffer, "%*d %lx %lx/%lx:%hx", &real_ip, &vpn_ip, &vpn_mask, &port) != 4)
     {
        syslog(LOG_ERR, "got bad ADD_HOST request: %s", cl->buffer);
@@ -600,6 +606,7 @@ int req_key_h(conn_list_t *cl)
   ip_t from;
   conn_list_t *fw;
 cp
+  if(!cl->status.active) return -1;
   if(sscanf(cl->buffer, "%*d %lx %lx", &to, &from) != 2)
     {
        syslog(LOG_ERR, "got bad request: %s", cl->buffer);
@@ -683,6 +690,7 @@ int ans_key_h(conn_list_t *cl)
   char *key;
   conn_list_t *fw, *gk;
 cp
+  if(!cl->status.active) return -1;
   if(sscanf(cl->buffer, "%*d %lx %lx %d %as", &to, &from, &expiry, &key) != 4)
     {
        syslog(LOG_ERR, "got bad ANS_KEY request: %s", cl->buffer);
@@ -742,6 +750,7 @@ int key_changed_h(conn_list_t *cl)
   ip_t from;
   conn_list_t *ik;
 cp
+  if(!cl->status.active) return -1;
   if(sscanf(cl->buffer, "%*d %lx", &from) != 1)
     {
        syslog(LOG_ERR, "got bad ANS_KEY request: %s", cl->buffer);
-- 
2.39.5