Don't send proxy requests for incoming connections.

[tinc] / src / meta.c

diff --git a/src/meta.c b/src/meta.c
index 1244bfd..3bf2809 100644 (file)
--- a/src/meta.c
+++ b/src/meta.c
@@ -185,21 +185,50 @@ bool receive_meta(connection_t *c) {
 
                        if(c->tcplen) {
                                char *tcpbuffer = buffer_read(&c->inbuf, c->tcplen);
-                               if(tcpbuffer) {
-                                       if(proxytype == PROXY_SOCKS4 && c->allow_request == ID) {
+                               if(!tcpbuffer)
+                                       break;
+
+                               if(!c->node) {
+                                       if(c->outgoing && proxytype == PROXY_SOCKS4 && c->allow_request == ID) {
                                                if(tcpbuffer[0] == 0 && tcpbuffer[1] == 0x5a) {
                                                        logger(DEBUG_CONNECTIONS, LOG_DEBUG, "Proxy request granted");
                                                } else {
                                                        logger(DEBUG_CONNECTIONS, LOG_ERR, "Proxy request rejected");
                                                        return false;
                                                }
-                                       } else
-                                               receive_tcppacket(c, tcpbuffer, c->tcplen);
-                                       c->tcplen = 0;
-                                       continue;
+                                       } else if(c->outgoing && proxytype == PROXY_SOCKS5 && c->allow_request == ID) {
+                                               if(tcpbuffer[0] != 5) {
+                                                       logger(DEBUG_CONNECTIONS, LOG_ERR, "Invalid response from proxy server");
+                                                       return false;
+                                               }
+                                               if(tcpbuffer[1] == 0xff) {
+                                                       logger(DEBUG_CONNECTIONS, LOG_ERR, "Proxy request rejected: unsuitable authentication method");
+                                                       return false;
+                                               }
+                                               if(tcpbuffer[2] != 5) {
+                                                       logger(DEBUG_CONNECTIONS, LOG_ERR, "Invalid response from proxy server");
+                                                       return false;
+                                               }
+                                               if(tcpbuffer[3] == 0) {
+                                                       logger(DEBUG_CONNECTIONS, LOG_DEBUG, "Proxy request granted");
+                                               } else {
+                                                       logger(DEBUG_CONNECTIONS, LOG_DEBUG, "Proxy request rejected");
+                                                       return false;
+                                               }
+                                       } else {
+                                               logger(DEBUG_CONNECTIONS, LOG_ERR, "c->tcplen set but c->node is NULL!");
+                                               abort();
+                                       }
                                } else {
-                                       break;
+                                       if(c->allow_request == ALL) {
+                                               receive_tcppacket(c, tcpbuffer, c->tcplen);
+                                       } else {
+                                               logger(DEBUG_CONNECTIONS, LOG_ERR, "Got unauthorized TCP packet from %s (%s)", c->name, c->hostname);
+                                               return false;
+                                       }
                                }
+
+                               c->tcplen = 0;
                        }
 
                        /* Otherwise we are waiting for a request */