Fix segmentation fault when trying to connect via a SOCKS5 proxy.

[tinc] / src / meta.c

diff --git a/src/meta.c b/src/meta.c
index 1b34246..e60c127 100644 (file)
--- a/src/meta.c
+++ b/src/meta.c
@@ -177,15 +177,45 @@ bool receive_meta(connection_t *c) {
 
                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");
+                               if(!c->node) {
+                                       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 if(proxytype == PROXY_SOCKS5 && c->allow_request == ID) {
+                                               if(c->buffer[0] != 5) {
+                                                       logger(LOG_ERR, "Invalid response from proxy server");
+                                                       return false;
+                                               }
+                                               if(c->buffer[1] == 0xff) {
+                                                       logger(LOG_ERR, "Proxy request rejected: unsuitable authentication method");
+                                                       return false;
+                                               }
+                                               if(c->buffer[2] != 5) {
+                                                       logger(LOG_ERR, "Invalid response from proxy server");
+                                                       return false;
+                                               }
+                                               if(c->buffer[3] == 0) {
+                                                       logger(LOG_DEBUG, "Proxy request granted");
+                                               } else {
+                                                       logger(LOG_DEBUG, "Proxy request rejected");
+                                                       return false;
+                                               }
                                        } else {
-                                               logger(LOG_ERR, "Proxy request rejected");
+                                               logger(LOG_ERR, "c->tcplen set but c->node is NULL!");
+                                               abort();
+                                       }
+                               } else {
+                                       if(c->allow_request == ALL) {
+                                               receive_tcppacket(c, c->buffer, c->tcplen);
+                                       } else {
+                                               logger(LOG_ERR, "Got unauthorized TCP packet from %s (%s)", c->name, c->hostname);
                                                return false;
                                        }
-                               } else 
-                                       receive_tcppacket(c, c->buffer, c->tcplen);
+                               }
 
                                c->buflen -= c->tcplen;
                                lenin -= c->tcplen - oldlen;