[tor-commits] [obfsproxy/master] We can now send 'SOCKS5_FAILED_UNSUPPORTED' replies as well!

[nickm at torproject.org]

commit 7eb36a85f4884668a259040e5dcb2350ed3b0595
Author: George Kadianakis <desnacked at gmail.com>
Date:   Tue May 24 16:43:28 2011 +0200

    We can now send 'SOCKS5_FAILED_UNSUPPORTED' replies as well!
---
 src/network.c |   13 +++++++++++--
 src/socks.c   |   22 ++++++++++++----------
 src/socks.h   |    3 +++
 3 files changed, 26 insertions(+), 12 deletions(-)

diff --git a/src/network.c b/src/network.c
index 835dff1..1f68804 100644
--- a/src/network.c
+++ b/src/network.c
@@ -268,6 +268,15 @@ socks_read_cb(struct bufferevent *bev, void *arg)
     return; /* need to read more data. */
   else if (r == -1)
     conn_free(conn); /* XXXX maybe send socks reply */
+  else if (r == -2) {
+    bufferevent_enable(bev, EV_WRITE);
+    bufferevent_disable(bev, EV_READ);
+    socks5_send_reply(bufferevent_get_output(bev), conn->socks_state,
+                      SOCKS5_FAILED_UNSUPPORTED);
+    bufferevent_setcb(bev, NULL,
+                      close_conn_on_flush, output_event_cb, conn);
+    return;
+  }
 }
 
 static void
@@ -399,8 +408,8 @@ output_event_cb(struct bufferevent *bev, short what, void *arg)
          * socks client */
         socks_state_set_address(conn->socks_state, sa);
       }
-      socks_send_reply(conn->socks_state, bufferevent_get_output(conn->input),
-                       0);
+      socks_send_reply(conn->socks_state, 
+                       bufferevent_get_output(conn->input), 0);
       /* we sent a socks reply.  We can finally move over to being a regular
          input bufferevent. */
       socks_state_free(conn->socks_state);
diff --git a/src/socks.c b/src/socks.c
index a388363..367c2f1 100644
--- a/src/socks.c
+++ b/src/socks.c
@@ -90,13 +90,13 @@ socks_errno_to_reply(socks_state_t *state, int error)
         return SOCKS5_FAILED_GENERAL;
       }      
     }
-  }
-  return -1;
+  } else
+    return -1;
 }
 
 /**
    Takes a command request from 'source', it evaluates it and if it's
-   legit it parses into 'parsereq'.
+   legit it parses it into 'parsereq'.
    
    It returns '1' if everything went fine.
    It returns '0' if we need more data from the client.
@@ -138,6 +138,7 @@ socks5_handle_request(struct evbuffer *source, struct parsereq *parsereq)
     printf("socks: Corrupted packet. Discarding.\n");
     goto err;
   }
+
   if (p[1] != SOCKS5_CMD_CONNECT)
     return -2; /* We must send reply to the client. */
 
@@ -495,13 +496,14 @@ handle_socks(struct evbuffer *source, struct evbuffer *dest,
     if (socks_state->state == ST_NEGOTIATION_DONE) {
       /* We know this connection. Let's see what it wants. */
       r = socks5_handle_request(source,&socks_state->parsereq);
-      if (r == -1)
-        goto broken;
-      else if (r == -2) {
-        socks5_send_reply(dest,socks_state,
-                          SOCKS5_FAILED_UNSUPPORTED);
+      if (r == -2) { /* Request CMD != CONNECT. */ 
+        socks_state->broken = 1;
+        return -2;
+      } else if (r == -1) /* Broken request. */
         goto broken;
-      } else if (r == 1)
+      else if (r == 0) /* Incomplete. */
+        return 0;
+      else if (r == 1) /* Neat request. */
         socks_state->state = ST_HAVE_ADDR;
       return r;
     }
@@ -565,6 +567,7 @@ socks_state_set_address(socks_state_t *state, const struct sockaddr *sa)
 }
 
 /**
+   This function sends a SOCKS{5,4} "Server Reply" to 'dest'.
    'error' is 0 if no errors were encountered during the SOCKS
    operation (normally a CONNECT with no errors means that the
    connect() was successful).
@@ -582,4 +585,3 @@ socks_send_reply(socks_state_t *state, struct evbuffer *dest, int error)
   else
     return -1;
 }
-
diff --git a/src/socks.h b/src/socks.h
index 01a76ff..09ebe28 100644
--- a/src/socks.h
+++ b/src/socks.h
@@ -28,6 +28,9 @@ int socks_state_get_address(const socks_state_t *state,
                             int *port_out);
 int socks_state_set_address(socks_state_t *state, const struct sockaddr *sa);
 int socks_send_reply(socks_state_t *state, struct evbuffer *dest, int error);
+int socks5_send_reply(struct evbuffer *reply_dest, 
+                      socks_state_t *state, int status);
+
 
 #define SOCKS_SUCCESS     0x0
 #define SOCKS_FAILED        0x01