Bump copyright
[privoxy.git] / jcc.c
diff --git a/jcc.c b/jcc.c
index b95f245..fa88995 100644 (file)
--- a/jcc.c
+++ b/jcc.c
@@ -1,4 +1,4 @@
-const char jcc_rcs[] = "$Id: jcc.c,v 1.402 2012/10/21 12:59:40 fabiankeil Exp $";
+const char jcc_rcs[] = "$Id: jcc.c,v 1.450 2016/12/24 16:01:32 fabiankeil Exp $";
 /*********************************************************************
  *
  * File        :  $Source: /cvsroot/ijbswa/current/jcc.c,v $
@@ -6,7 +6,7 @@ const char jcc_rcs[] = "$Id: jcc.c,v 1.402 2012/10/21 12:59:40 fabiankeil Exp $"
  * Purpose     :  Main file.  Contains main() method, main loop, and
  *                the main connection-handling function.
  *
- * Copyright   :  Written by and Copyright (C) 2001-2012 the
+ * Copyright   :  Written by and Copyright (C) 2001-2016 the
  *                Privoxy team. http://www.privoxy.org/
  *
  *                Based on the Internet Junkbuster originally written
@@ -50,6 +50,7 @@ const char jcc_rcs[] = "$Id: jcc.c,v 1.402 2012/10/21 12:59:40 fabiankeil Exp $"
 #  ifndef STRICT
 #   define STRICT
 #  endif
+#  include <winsock2.h>
 #  include <windows.h>
 #  include <process.h>
 # endif /* ndef FEATURE_PTHREAD */
@@ -115,6 +116,9 @@ const char jcc_rcs[] = "$Id: jcc.c,v 1.402 2012/10/21 12:59:40 fabiankeil Exp $"
 #include "cgi.h"
 #include "loadcfg.h"
 #include "urlmatch.h"
+#ifdef FEATURE_CLIENT_TAGS
+#include "client-tags.h"
+#endif
 
 const char jcc_h_rcs[] = JCC_H_VERSION;
 const char project_h_rcs[] = PROJECT_H_VERSION;
@@ -174,6 +178,11 @@ static int32 server_thread(void *data);
 #define sleep(N)  DosSleep(((N) * 100))
 #endif
 
+#ifdef FUZZ
+int process_fuzzed_input(char *fuzz_input_type, char *fuzz_input_file);
+void show_fuzz_usage(const char *name);
+#endif
+
 #ifdef MUTEX_LOCKS_AVAILABLE
 /*
  * XXX: Does the locking stuff really belong in this file?
@@ -182,6 +191,13 @@ privoxy_mutex_t log_mutex;
 privoxy_mutex_t log_init_mutex;
 privoxy_mutex_t connection_reuse_mutex;
 
+#ifdef FEATURE_EXTERNAL_FILTERS
+privoxy_mutex_t external_filter_mutex;
+#endif
+#ifdef FEATURE_CLIENT_TAGS
+privoxy_mutex_t client_tags_mutex;
+#endif
+
 #if !defined(HAVE_GETHOSTBYADDR_R) || !defined(HAVE_GETHOSTBYNAME_R)
 privoxy_mutex_t resolver_mutex;
 #endif /* !defined(HAVE_GETHOSTBYADDR_R) || !defined(HAVE_GETHOSTBYNAME_R) */
@@ -208,12 +224,10 @@ static int received_hup_signal = 0;
 
 /* HTTP snipplets. */
 static const char CSUCCEED[] =
-   "HTTP/1.1 200 Connection established\r\n"
-   "Proxy-Agent: Privoxy/" VERSION "\r\n\r\n";
+   "HTTP/1.1 200 Connection established\r\n\r\n";
 
 static const char CHEADER[] =
    "HTTP/1.1 400 Invalid header received from client\r\n"
-   "Proxy-Agent: Privoxy " VERSION "\r\n"
    "Content-Type: text/plain\r\n"
    "Connection: close\r\n\r\n"
    "Invalid header received from client.\r\n";
@@ -233,7 +247,6 @@ static const char GOPHER_RESPONSE[] =
 /* XXX: should be a template */
 static const char MISSING_DESTINATION_RESPONSE[] =
    "HTTP/1.1 400 Bad request received from client\r\n"
-   "Proxy-Agent: Privoxy " VERSION "\r\n"
    "Content-Type: text/plain\r\n"
    "Connection: close\r\n\r\n"
    "Bad request. Privoxy was unable to extract the destination.\r\n";
@@ -241,7 +254,6 @@ static const char MISSING_DESTINATION_RESPONSE[] =
 /* XXX: should be a template */
 static const char INVALID_SERVER_HEADERS_RESPONSE[] =
    "HTTP/1.1 502 Server or forwarder response invalid\r\n"
-   "Proxy-Agent: Privoxy " VERSION "\r\n"
    "Content-Type: text/plain\r\n"
    "Connection: close\r\n\r\n"
    "Bad response. The server or forwarder response doesn't look like HTTP.\r\n";
@@ -249,25 +261,34 @@ static const char INVALID_SERVER_HEADERS_RESPONSE[] =
 /* XXX: should be a template */
 static const char MESSED_UP_REQUEST_RESPONSE[] =
    "HTTP/1.1 400 Malformed request after rewriting\r\n"
-   "Proxy-Agent: Privoxy " VERSION "\r\n"
    "Content-Type: text/plain\r\n"
    "Connection: close\r\n\r\n"
    "Bad request. Messed up with header filters.\r\n";
 
 static const char TOO_MANY_CONNECTIONS_RESPONSE[] =
    "HTTP/1.1 503 Too many open connections\r\n"
-   "Proxy-Agent: Privoxy " VERSION "\r\n"
    "Content-Type: text/plain\r\n"
    "Connection: close\r\n\r\n"
    "Maximum number of open connections reached.\r\n";
 
 static const char CLIENT_CONNECTION_TIMEOUT_RESPONSE[] =
    "HTTP/1.1 504 Connection timeout\r\n"
-   "Proxy-Agent: Privoxy " VERSION "\r\n"
    "Content-Type: text/plain\r\n"
    "Connection: close\r\n\r\n"
    "The connection timed out because the client request didn't arrive in time.\r\n";
 
+static const char CLIENT_BODY_PARSE_ERROR_RESPONSE[] =
+   "HTTP/1.1 400 Failed reading client body\r\n"
+   "Content-Type: text/plain\r\n"
+   "Connection: close\r\n\r\n"
+   "Failed parsing or buffering the chunk-encoded client body.\r\n";
+
+static const char UNSUPPORTED_CLIENT_EXPECTATION_ERROR_RESPONSE[] =
+   "HTTP/1.1 417 Expecting too much\r\n"
+   "Content-Type: text/plain\r\n"
+   "Connection: close\r\n\r\n"
+   "Privoxy detected an unsupported Expect header value.\r\n";
+
 /* A function to crunch a response */
 typedef struct http_response *(*crunch_func_ptr)(struct client_state *);
 
@@ -426,6 +447,40 @@ static int client_protocol_is_unsupported(const struct client_state *csp, char *
 }
 
 
+/*********************************************************************
+ *
+ * Function    :  client_has_unsupported_expectations
+ *
+ * Description :  Checks if the client used an unsupported expectation
+ *                in which case an error message is delivered.
+ *
+ * Parameters  :
+ *          1  :  csp = Current client state (buffers, headers, etc...)
+ *
+ * Returns     :  TRUE if an error response has been generated, or
+ *                FALSE if the request doesn't look invalid.
+ *
+ *********************************************************************/
+static int client_has_unsupported_expectations(const struct client_state *csp)
+{
+   if ((csp->flags & CSP_FLAG_UNSUPPORTED_CLIENT_EXPECTATION))
+   {
+      log_error(LOG_LEVEL_ERROR,
+         "Rejecting request from client %s with unsupported Expect header value",
+         csp->ip_addr_str);
+      log_error(LOG_LEVEL_CLF,
+         "%s - - [%T] \"%s\" 417 0", csp->ip_addr_str, csp->http->cmd);
+      write_socket(csp->cfd, UNSUPPORTED_CLIENT_EXPECTATION_ERROR_RESPONSE,
+         strlen(UNSUPPORTED_CLIENT_EXPECTATION_ERROR_RESPONSE));
+
+      return TRUE;
+   }
+
+   return FALSE;
+
+}
+
+
 /*********************************************************************
  *
  * Function    :  get_request_destination_elsewhere
@@ -866,7 +921,7 @@ static void build_request_line(struct client_state *csp, const struct forward_sp
    *request_line = strdup(http->gpc);
    string_append(request_line, " ");
 
-   if (fwd->forward_host)
+   if (fwd->forward_host && fwd->type != FORWARD_WEBSERVER)
    {
       string_append(request_line, http->url);
    }
@@ -904,7 +959,8 @@ static jb_err change_request_destination(struct client_state *csp)
    struct http_request *http = csp->http;
    jb_err err;
 
-   log_error(LOG_LEVEL_INFO, "Rewrite detected: %s", csp->headers->first->str);
+   log_error(LOG_LEVEL_REDIRECTS, "Rewrite detected: %s",
+      csp->headers->first->str);
    free_http_request(http);
    err = parse_http_request(csp->headers->first->str, http);
    if (JB_ERR_OK != err)
@@ -912,11 +968,6 @@ static jb_err change_request_destination(struct client_state *csp)
       log_error(LOG_LEVEL_ERROR, "Couldn't parse rewritten request: %s.",
          jb_err_to_string(err));
    }
-   else
-   {
-      /* XXX: ocmd is a misleading name */
-      http->ocmd = strdup_or_die(http->cmd);
-   }
 
    return err;
 }
@@ -951,6 +1002,7 @@ static int server_response_is_complete(struct client_state *csp,
        */
       csp->expected_content_length = 0;
       content_length_known = TRUE;
+      csp->flags |= CSP_FLAG_SERVER_CONTENT_LENGTH_SET;
    }
 
    if (csp->http->status == 204 || csp->http->status == 304)
@@ -960,6 +1012,7 @@ static int server_response_is_complete(struct client_state *csp,
        */
       csp->expected_content_length = 0;
       content_length_known = TRUE;
+      csp->flags |= CSP_FLAG_SERVER_CONTENT_LENGTH_SET;
    }
 
    return (content_length_known && ((0 == csp->expected_content_length)
@@ -1064,11 +1117,9 @@ void save_connection_destination(jb_socket sfd,
  *               we do.
  *
  *               Data that doesn't belong to the current request is
- *               thrown away to let the client retry on a clean socket.
- *
- *               XXX: This is a hack until we can deal with multiple
- *                    pipelined requests at the same time.
- *
+ *               either thrown away to let the client retry on a clean
+ *               socket, or stashed to be dealt with after the current
+ *               request is served.
  *
  * Parameters  :
  *          1  :  csp = Current client state (buffers, headers, etc...)
@@ -1109,7 +1160,8 @@ static void verify_request_length(struct client_state *csp)
    }
 
    if (!(csp->flags & CSP_FLAG_CLIENT_REQUEST_COMPLETELY_READ)
-    && ((csp->client_iob->cur[0] != '\0') || (csp->expected_client_content_length != 0)))
+      && ((csp->client_iob->cur < csp->client_iob->eod)
+         || (csp->expected_client_content_length != 0)))
    {
       if (strcmpic(csp->http->gpc, "GET")
          && strcmpic(csp->http->gpc, "HEAD")
@@ -1119,9 +1171,7 @@ static void verify_request_length(struct client_state *csp)
       {
          /* XXX: this is an incomplete hack */
          csp->flags &= ~CSP_FLAG_CLIENT_REQUEST_COMPLETELY_READ;
-         csp->flags |= CSP_FLAG_SERVER_SOCKET_TAINTED;
-         log_error(LOG_LEVEL_CONNECT,
-            "There might be a request body. The connection will not be kept alive.");
+         log_error(LOG_LEVEL_CONNECT, "There better be a request body.");
       }
       else
       {
@@ -1143,7 +1193,7 @@ static void verify_request_length(struct client_state *csp)
              * it once we're done serving the current request.
              */
             csp->flags |= CSP_FLAG_PIPELINED_REQUEST_WAITING;
-            assert(csp->client_iob->eod > csp->client_iob->cur);
+            assert(csp->client_iob->eod >= csp->client_iob->cur);
             log_error(LOG_LEVEL_CONNECT, "Complete client request followed by "
                "%d bytes of pipelined data received.",
                (int)(csp->client_iob->eod - csp->client_iob->cur));
@@ -1182,7 +1232,7 @@ static void mark_server_socket_tainted(struct client_state *csp)
     * actually been reused.
     */
    if ((csp->flags & CSP_FLAG_SERVER_CONNECTION_KEEP_ALIVE)
-      && !(csp->flags |= CSP_FLAG_SERVER_SOCKET_TAINTED))
+      && !(csp->flags & CSP_FLAG_SERVER_SOCKET_TAINTED))
    {
       log_error(LOG_LEVEL_CONNECT,
          "Marking the server socket %d tainted.",
@@ -1234,7 +1284,12 @@ static char *get_request_line(struct client_state *csp)
 
    do
    {
-      if (!data_is_available(csp->cfd, csp->config->socket_timeout))
+      if (
+#ifdef FUZZ
+          0 == (csp->flags & CSP_FLAG_FUZZED_INPUT) &&
+#endif
+          !data_is_available(csp->cfd, csp->config->socket_timeout)
+          )
       {
          if (socket_is_still_alive(csp->cfd))
          {
@@ -1274,6 +1329,287 @@ static char *get_request_line(struct client_state *csp)
 
 }
 
+enum chunk_status
+{
+   CHUNK_STATUS_MISSING_DATA,
+   CHUNK_STATUS_BODY_COMPLETE,
+   CHUNK_STATUS_PARSE_ERROR
+};
+
+
+/*********************************************************************
+ *
+ * Function    :  chunked_body_is_complete
+ *
+ * Description :  Figures out whether or not a chunked body is complete.
+ *
+ *                Currently it always starts at the beginning of the
+ *                buffer which is somewhat wasteful and prevents Privoxy
+ *                from starting to forward the correctly parsed chunks
+ *                as soon as theoretically possible.
+ *
+ *                Should be modified to work with a common buffer,
+ *                and allow the caller to skip already parsed chunks.
+ *
+ *                This would allow the function to be used for unbuffered
+ *                response bodies as well.
+ *
+ * Parameters  :
+ *          1  :  iob = Buffer with the body to check.
+ *          2  :  length = Length of complete body
+ *
+ * Returns     :  Enum with the result of the check.
+ *
+ *********************************************************************/
+static enum chunk_status chunked_body_is_complete(struct iob *iob, size_t *length)
+{
+   unsigned int chunksize;
+   char *p = iob->cur;
+
+   do
+   {
+      /*
+       * We need at least a single digit, followed by "\r\n",
+       * followed by an unknown amount of data, followed by "\r\n".
+       */
+      if (p + 5 > iob->eod)
+      {
+         return CHUNK_STATUS_MISSING_DATA;
+      }
+      if (sscanf(p, "%x", &chunksize) != 1)
+      {
+         return CHUNK_STATUS_PARSE_ERROR;
+      }
+
+      /*
+       * We want at least a single digit, followed by "\r\n",
+       * followed by the specified amount of data, followed by "\r\n".
+       */
+      if (p + chunksize + 5 > iob->eod)
+      {
+         return CHUNK_STATUS_MISSING_DATA;
+      }
+
+      /* Skip chunk-size. */
+      p = strstr(p, "\r\n");
+      if (NULL == p)
+      {
+         return CHUNK_STATUS_PARSE_ERROR;
+      }
+      /* Move beyond the chunkdata. */
+      p += 2 + chunksize;
+
+      /* There should be another "\r\n" to skip */
+      if (memcmp(p, "\r\n", 2))
+      {
+         return CHUNK_STATUS_PARSE_ERROR;
+      }
+      p += 2;
+   } while (chunksize > 0U);
+
+   *length = (size_t)(p - iob->cur);
+   assert(*length <= (size_t)(iob->eod - iob->cur));
+   assert(p <= iob->eod);
+
+   return CHUNK_STATUS_BODY_COMPLETE;
+
+}
+
+
+/*********************************************************************
+ *
+ * Function    : receive_chunked_client_request_body
+ *
+ * Description : Read the chunk-encoded client request body.
+ *               Failures are dealt with.
+ *
+ * Parameters  :
+ *          1  :  csp = Current client state (buffers, headers, etc...)
+ *
+ * Returns     :  JB_ERR_OK or JB_ERR_PARSE
+ *
+ *********************************************************************/
+static jb_err receive_chunked_client_request_body(struct client_state *csp)
+{
+   size_t body_length;
+   enum chunk_status status;
+
+   while (CHUNK_STATUS_MISSING_DATA ==
+      (status = chunked_body_is_complete(csp->client_iob,&body_length)))
+   {
+      char buf[BUFFER_SIZE];
+      int len;
+
+      if (!data_is_available(csp->cfd, csp->config->socket_timeout))
+      {
+         log_error(LOG_LEVEL_ERROR,
+            "Timeout while waiting for the client body.");
+         break;
+      }
+      len = read_socket(csp->cfd, buf, sizeof(buf) - 1);
+      if (len <= 0)
+      {
+         log_error(LOG_LEVEL_ERROR, "Read the client body failed: %E");
+         break;
+      }
+      if (add_to_iob(csp->client_iob, csp->config->buffer_limit, buf, len))
+      {
+         break;
+      }
+   }
+   if (status != CHUNK_STATUS_BODY_COMPLETE)
+   {
+      write_socket(csp->cfd, CLIENT_BODY_PARSE_ERROR_RESPONSE,
+         strlen(CLIENT_BODY_PARSE_ERROR_RESPONSE));
+      log_error(LOG_LEVEL_CLF,
+         "%s - - [%T] \"Failed reading chunked client body\" 400 0", csp->ip_addr_str);
+      return JB_ERR_PARSE;
+   }
+   log_error(LOG_LEVEL_CONNECT,
+      "Chunked client body completely read. Length: %d", body_length);
+   csp->expected_client_content_length = body_length;
+
+   return JB_ERR_OK;
+
+}
+
+
+#ifdef FUZZ
+/*********************************************************************
+ *
+ * Function    :  fuzz_chunked_transfer_encoding
+ *
+ * Description :  Treat the fuzzed input as chunked transfer encoding
+ *                to check and dechunk.
+ *
+ * Parameters  :
+ *          1  :  csp      = Used to store the data.
+ *          2  :  fuzz_input_file = File to read the input from.
+ *
+ * Returns     : Result of dechunking
+ *
+ *********************************************************************/
+extern int fuzz_chunked_transfer_encoding(struct client_state *csp, char *fuzz_input_file)
+{
+   size_t length;
+   size_t size = (size_t)(csp->iob->eod - csp->iob->cur);
+   enum chunk_status status;
+
+   status = chunked_body_is_complete(csp->iob, &length);
+   if (CHUNK_STATUS_BODY_COMPLETE != status)
+   {
+      log_error(LOG_LEVEL_INFO, "Chunked body is incomplete or invalid");
+   }
+
+   return (JB_ERR_OK == remove_chunked_transfer_coding(csp->iob->cur, &size));
+
+}
+
+
+/*********************************************************************
+ *
+ * Function    : fuzz_client_request
+ *
+ * Description : Try to get a client request from the fuzzed input.
+ *
+ * Parameters  :
+ *          1  :  csp = Current client state (buffers, headers, etc...)
+ *          2  :  fuzz_input_file = File to read the input from.
+ *
+ * Returns     :  Result of fuzzing.
+ *
+ *********************************************************************/
+extern int fuzz_client_request(struct client_state *csp, char *fuzz_input_file)
+{
+   jb_err err;
+
+   csp->cfd = 0;
+   csp->ip_addr_str = "fuzzer";
+
+   if (strcmp(fuzz_input_file, "-") != 0)
+   {
+      log_error(LOG_LEVEL_FATAL,
+         "Fuzzed client requests can currenty only be read from stdin (-).");
+   }
+   err = receive_client_request(csp);
+   if (err != JB_ERR_OK)
+   {
+      return 1;
+   }
+   err = parse_client_request(csp);
+   if (err != JB_ERR_OK)
+   {
+      return 1;
+   }
+
+   return 0;
+
+}
+#endif  /* def FUZZ */
+
+
+#ifdef FEATURE_FORCE_LOAD
+/*********************************************************************
+ *
+ * Function    :  force_required
+ *
+ * Description : Checks a request line to see if it contains
+ *               the FORCE_PREFIX. If it does, it is removed
+ *               unless enforcing requests has beend disabled.
+ *
+ * Parameters  :
+ *          1  :  request_line = HTTP request line
+ *
+ * Returns     :  TRUE if force is required, FALSE otherwise.
+ *
+ *********************************************************************/
+static int force_required(const struct client_state *csp, char *request_line)
+{
+   char *p;
+
+   p = strstr(request_line, "http://");
+   if (p != NULL)
+   {
+      /* Skip protocol */
+      p += strlen("http://");
+   }
+   else
+   {
+      /* Intercepted request usually don't specify the protocol. */
+      p = request_line;
+   }
+
+   /* Go to the beginning of the path */
+   p = strstr(p, "/");
+   if (p == NULL)
+   {
+      /*
+       * If the path is missing the request line is invalid and we
+       * are done here. The client-visible rejection happens later on.
+       */
+      return 0;
+   }
+
+   if (0 == strncmpic(p, FORCE_PREFIX, strlen(FORCE_PREFIX) - 1))
+   {
+      if (!(csp->config->feature_flags & RUNTIME_FEATURE_ENFORCE_BLOCKS))
+      {
+         /* XXX: Should clean more carefully */
+         strclean(request_line, FORCE_PREFIX);
+         log_error(LOG_LEVEL_FORCE,
+            "Enforcing request: \"%s\".", request_line);
+
+         return 1;
+      }
+      log_error(LOG_LEVEL_FORCE,
+         "Ignored force prefix in request: \"%s\".", request_line);
+   }
+
+   return 0;
+
+}
+#endif /* def FEATURE_FORCE_LOAD */
+
 
 /*********************************************************************
  *
@@ -1322,23 +1658,9 @@ static jb_err receive_client_request(struct client_state *csp)
    }
 
 #ifdef FEATURE_FORCE_LOAD
-   /*
-    * If this request contains the FORCE_PREFIX and blocks
-    * aren't enforced, get rid of it and set the force flag.
-    */
-   if (strstr(req, FORCE_PREFIX))
+   if (force_required(csp, req))
    {
-      if (csp->config->feature_flags & RUNTIME_FEATURE_ENFORCE_BLOCKS)
-      {
-         log_error(LOG_LEVEL_FORCE,
-            "Ignored force prefix in request: \"%s\".", req);
-      }
-      else
-      {
-         strclean(req, FORCE_PREFIX);
-         log_error(LOG_LEVEL_FORCE, "Enforcing request: \"%s\".", req);
-         csp->flags |= CSP_FLAG_FORCED;
-      }
+      csp->flags |= CSP_FLAG_FORCED;
    }
 #endif /* def FEATURE_FORCE_LOAD */
 
@@ -1403,6 +1725,14 @@ static jb_err receive_client_request(struct client_state *csp)
       }
       else
       {
+         if (!strncmpic(p, "Transfer-Encoding:", 18))
+         {
+            /*
+             * XXX: should be called through sed()
+             *      but currently can't.
+             */
+            client_transfer_encoding(csp, &p);
+         }
          /*
           * We were able to read a complete
           * header and can finally enlist it.
@@ -1433,6 +1763,12 @@ static jb_err receive_client_request(struct client_state *csp)
       }
    }
 
+#ifdef FEATURE_CLIENT_TAGS
+   /* XXX: If the headers were enlisted sooner, passing csp would do. */
+   set_client_address(csp, headers);
+   get_tag_list_for_client(csp->client_tags, csp->client_address);
+#endif
+
    /*
     * Determine the actions for this URL
     */
@@ -1448,17 +1784,13 @@ static jb_err receive_client_request(struct client_state *csp)
       get_url_actions(csp, http);
    }
 
-   /*
-    * Save a copy of the original request for logging
-    */
-   http->ocmd = strdup_or_die(http->cmd);
    enlist(csp->headers, http->cmd);
 
    /* Append the previously read headers */
-   list_append_list_unique(csp->headers, headers);
+   err = list_append_list_unique(csp->headers, headers);
    destroy_list(headers);
 
-   return JB_ERR_OK;
+   return err;
 
 }
 
@@ -1496,7 +1828,21 @@ static jb_err parse_client_request(struct client_state *csp)
 
    if (csp->http->ssl == 0)
    {
-      csp->expected_client_content_length = get_expected_content_length(csp->headers);
+      /*
+       * This whole block belongs to chat() but currently
+       * has to be executed before sed().
+       */
+      if (csp->flags & CSP_FLAG_CHUNKED_CLIENT_BODY)
+      {
+         if (receive_chunked_client_request_body(csp) != JB_ERR_OK)
+         {
+            return JB_ERR_PARSE;
+         }
+      }
+      else
+      {
+         csp->expected_client_content_length = get_expected_content_length(csp->headers);
+      }
       verify_request_length(csp);
    }
 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
@@ -1504,9 +1850,12 @@ static jb_err parse_client_request(struct client_state *csp)
    err = sed(csp, FILTER_CLIENT_HEADERS);
    if (JB_ERR_OK != err)
    {
-      /* XXX: Should be handled in sed(). */
-      assert(err == JB_ERR_PARSE);
-      log_error(LOG_LEVEL_FATAL, "Failed to parse client headers.");
+      log_error(LOG_LEVEL_ERROR, "Failed to parse client request from %s.",
+         csp->ip_addr_str);
+      log_error(LOG_LEVEL_CLF, "%s - - [%T] \"%s\" 400 0",
+         csp->ip_addr_str, csp->http->cmd);
+      write_socket(csp->cfd, CHEADER, strlen(CHEADER));
+      return JB_ERR_PARSE;
    }
    csp->flags |= CSP_FLAG_CLIENT_HEADER_PARSING_DONE;
 
@@ -1529,6 +1878,11 @@ static jb_err parse_client_request(struct client_state *csp)
       return JB_ERR_PARSE;
    }
 
+   if (client_has_unsupported_expectations(csp))
+   {
+      return JB_ERR_PARSE;
+   }
+
    return JB_ERR_OK;
 
 }
@@ -1536,31 +1890,72 @@ static jb_err parse_client_request(struct client_state *csp)
 
 /*********************************************************************
  *
- * Function    :  chat
- *
- * Description :  Once a connection from the client has been accepted,
- *                this function is called (via serve()) to handle the
- *                main business of the communication.  This function
- *                returns after dealing with a single request. It can
- *                be called multiple times with the same client socket
- *                if the client is keeping the connection alive.
- *
- *                The decision whether or not a client connection will
- *                be kept alive is up to the caller which also must
- *                close the client socket when done.
+ * Function    : send_http_request
  *
- *                FIXME: chat is nearly thousand lines long.
- *                Ridiculous.
+ * Description : Sends the HTTP headers from the client request
+ *               and all the body data that has already been received.
  *
  * Parameters  :
  *          1  :  csp = Current client state (buffers, headers, etc...)
  *
- * Returns     :  Nothing.
+ * Returns     :  0 on success, anything else is na error.
  *
  *********************************************************************/
-static void chat(struct client_state *csp)
+static int send_http_request(struct client_state *csp)
 {
-   char buf[BUFFER_SIZE];
+   char *hdr;
+   int write_failure;
+
+   hdr = list_to_text(csp->headers);
+   if (hdr == NULL)
+   {
+      /* FIXME Should handle error properly */
+      log_error(LOG_LEVEL_FATAL, "Out of memory parsing client header");
+   }
+   list_remove_all(csp->headers);
+
+   /*
+    * Write the client's (modified) header to the server
+    * (along with anything else that may be in the buffer)
+    */
+   write_failure = 0 != write_socket(csp->server_connection.sfd, hdr, strlen(hdr));
+   freez(hdr);
+
+   if (write_failure)
+   {
+      log_error(LOG_LEVEL_CONNECT, "Failed sending request headers to: %s: %E",
+         csp->http->hostport);
+   }
+   else if (((csp->flags & CSP_FLAG_PIPELINED_REQUEST_WAITING) == 0)
+      && (flush_socket(csp->server_connection.sfd, csp->client_iob) < 0))
+   {
+      write_failure = 1;
+      log_error(LOG_LEVEL_CONNECT, "Failed sending request body to: %s: %E",
+         csp->http->hostport);
+   }
+
+   return write_failure;
+
+}
+
+
+/*********************************************************************
+ *
+ * Function    :  handle_established_connection
+ *
+ * Description :  Shuffle data between client and server once the
+ *                connection has been established.
+ *
+ * Parameters  :
+ *          1  :  csp = Current client state (buffers, headers, etc...)
+ *
+ * Returns     :  Nothing.
+ *
+ *********************************************************************/
+static void handle_established_connection(struct client_state *csp,
+                                          const struct forward_spec *fwd)
+{
+   char buf[BUFFER_SIZE];
    char *hdr;
    char *p;
    fd_set rfds;
@@ -1569,7 +1964,6 @@ static void chat(struct client_state *csp)
    int server_body;
    int ms_iis5_hack = 0;
    unsigned long long byte_count = 0;
-   const struct forward_spec *fwd;
    struct http_request *http;
    long len = 0; /* for buffer sizes (and negative error codes) */
    int buffer_and_filter_content = 0;
@@ -1585,223 +1979,6 @@ static void chat(struct client_state *csp)
 
    http = csp->http;
 
-   if (receive_client_request(csp) != JB_ERR_OK)
-   {
-      return;
-   }
-   if (parse_client_request(csp) != JB_ERR_OK)
-   {
-      return;
-   }
-
-   /* decide how to route the HTTP request */
-   fwd = forward_url(csp, http);
-   if (NULL == fwd)
-   {
-      log_error(LOG_LEVEL_FATAL, "gateway spec is NULL!?!?  This can't happen!");
-      /* Never get here - LOG_LEVEL_FATAL causes program exit */
-      return;
-   }
-
-   /*
-    * build the http request to send to the server
-    * we have to do one of the following:
-    *
-    * create = use the original HTTP request to create a new
-    *          HTTP request that has either the path component
-    *          without the http://domainspec (w/path) or the
-    *          full orininal URL (w/url)
-    *          Note that the path and/or the HTTP version may
-    *          have been altered by now.
-    *
-    * connect = Open a socket to the host:port of the server
-    *           and short-circuit server and client socket.
-    *
-    * pass =  Pass the request unchanged if forwarding a CONNECT
-    *         request to a parent proxy. Note that we'll be sending
-    *         the CFAIL message ourselves if connecting to the parent
-    *         fails, but we won't send a CSUCCEED message if it works,
-    *         since that would result in a double message (ours and the
-    *         parent's). After sending the request to the parent, we simply
-    *         tunnel.
-    *
-    * here's the matrix:
-    *                        SSL
-    *                    0        1
-    *                +--------+--------+
-    *                |        |        |
-    *             0  | create | connect|
-    *                | w/path |        |
-    *  Forwarding    +--------+--------+
-    *                |        |        |
-    *             1  | create | pass   |
-    *                | w/url  |        |
-    *                +--------+--------+
-    *
-    */
-
-   if (http->ssl && connect_port_is_forbidden(csp))
-   {
-      const char *acceptable_connect_ports =
-         csp->action->string[ACTION_STRING_LIMIT_CONNECT];
-      assert(NULL != acceptable_connect_ports);
-      log_error(LOG_LEVEL_INFO, "Request from %s marked for blocking. "
-         "limit-connect{%s} doesn't allow CONNECT requests to %s",
-         csp->ip_addr_str, acceptable_connect_ports, csp->http->hostport);
-      csp->action->flags |= ACTION_BLOCK;
-      http->ssl = 0;
-   }
-
-   if (http->ssl == 0)
-   {
-      freez(csp->headers->first->str);
-      build_request_line(csp, fwd, &csp->headers->first->str);
-   }
-
-   /*
-    * We have a request. Check if one of the crunchers wants it.
-    */
-   if (crunch_response_triggered(csp, crunchers_all))
-   {
-      /*
-       * Yes. The client got the crunch response and we're done here.
-       */
-      return;
-   }
-
-   log_applied_actions(csp->action);
-   log_error(LOG_LEVEL_GPC, "%s%s", http->hostport, http->path);
-
-   if (fwd->forward_host)
-   {
-      log_error(LOG_LEVEL_CONNECT, "via [%s]:%d to: %s",
-         fwd->forward_host, fwd->forward_port, http->hostport);
-   }
-   else
-   {
-      log_error(LOG_LEVEL_CONNECT, "to %s", http->hostport);
-   }
-
-   /* here we connect to the server, gateway, or the forwarder */
-
-#ifdef FEATURE_CONNECTION_KEEP_ALIVE
-   if ((csp->server_connection.sfd != JB_INVALID_SOCKET)
-      && socket_is_still_alive(csp->server_connection.sfd)
-      && connection_destination_matches(&csp->server_connection, http, fwd))
-   {
-      log_error(LOG_LEVEL_CONNECT,
-         "Reusing server socket %d connected to %s. Total requests: %u.",
-         csp->server_connection.sfd, csp->server_connection.host,
-         csp->server_connection.requests_sent_total);
-   }
-   else
-   {
-      if (csp->server_connection.sfd != JB_INVALID_SOCKET)
-      {
-         log_error(LOG_LEVEL_CONNECT,
-            "Closing server socket %u. Opened for %s.",
-            csp->server_connection.sfd, csp->server_connection.host);
-         close_socket(csp->server_connection.sfd);
-         mark_connection_closed(&csp->server_connection);
-      }
-#endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
-
-      csp->server_connection.sfd = forwarded_connect(fwd, http, csp);
-
-      if (csp->server_connection.sfd == JB_INVALID_SOCKET)
-      {
-         if (fwd->type != SOCKS_NONE)
-         {
-            /* Socks error. */
-            rsp = error_response(csp, "forwarding-failed");
-         }
-         else if (errno == EINVAL)
-         {
-            rsp = error_response(csp, "no-such-domain");
-         }
-         else
-         {
-            rsp = error_response(csp, "connect-failed");
-         }
-
-         /* Write the answer to the client */
-         if (rsp != NULL)
-         {
-            send_crunch_response(csp, rsp);
-         }
-
-         return;
-      }
-#ifdef FEATURE_CONNECTION_KEEP_ALIVE
-      save_connection_destination(csp->server_connection.sfd,
-         http, fwd, &csp->server_connection);
-      csp->server_connection.keep_alive_timeout =
-         (unsigned)csp->config->keep_alive_timeout;
-   }
-#endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
-
-   csp->server_connection.requests_sent_total++;
-
-   if (fwd->forward_host || (http->ssl == 0))
-   {
-      int write_failure;
-      hdr = list_to_text(csp->headers);
-      if (hdr == NULL)
-      {
-         /* FIXME Should handle error properly */
-         log_error(LOG_LEVEL_FATAL, "Out of memory parsing client header");
-      }
-      list_remove_all(csp->headers);
-
-      /*
-       * Write the client's (modified) header to the server
-       * (along with anything else that may be in the buffer)
-       */
-      write_failure = 0 != write_socket(csp->server_connection.sfd, hdr, strlen(hdr));
-      freez(hdr);
-
-      if (write_failure)
-      {
-         log_error(LOG_LEVEL_CONNECT,
-            "Failed sending request headers to: %s: %E", http->hostport);
-      }
-      else if (((csp->flags & CSP_FLAG_PIPELINED_REQUEST_WAITING) == 0)
-         && (flush_socket(csp->server_connection.sfd, csp->client_iob) < 0))
-      {
-         write_failure = 1;
-         log_error(LOG_LEVEL_CONNECT,
-            "Failed sending request body to: %s: %E", http->hostport);
-      }
-
-      if (write_failure)
-      {
-         rsp = error_response(csp, "connect-failed");
-         if (rsp)
-         {
-            send_crunch_response(csp, rsp);
-         }
-         return;
-      }
-   }
-   else
-   {
-      /*
-       * We're running an SSL tunnel and we're not forwarding,
-       * so just ditch the client headers, send the "connect succeeded"
-       * message to the client, flush the rest, and get out of the way.
-       */
-      list_remove_all(csp->headers);
-      if (write_socket(csp->cfd, CSUCCEED, strlen(CSUCCEED)))
-      {
-         return;
-      }
-      clear_iob(csp->client_iob);
-   }
-
-   log_error(LOG_LEVEL_CONNECT, "to %s successful", http->hostport);
-
-   csp->server_connection.request_sent = time(NULL);
-
    maxfd = (csp->cfd > csp->server_connection.sfd) ?
       csp->cfd : csp->server_connection.sfd;
 
@@ -1811,7 +1988,9 @@ static void chat(struct client_state *csp)
 
    server_body = 0;
 
+#ifdef FEATURE_CONNECTION_KEEP_ALIVE
    watch_client_socket = 0 == (csp->flags & CSP_FLAG_PIPELINED_REQUEST_WAITING);
+#endif
 
    for (;;)
    {
@@ -2366,7 +2545,13 @@ static void chat(struct client_state *csp)
              */
             if (JB_ERR_OK != sed(csp, FILTER_SERVER_HEADERS))
             {
-               log_error(LOG_LEVEL_FATAL, "Failed to parse server headers.");
+               log_error(LOG_LEVEL_CLF,
+                  "%s - - [%T] \"%s\" 502 0", csp->ip_addr_str, http->cmd);
+               write_socket(csp->cfd, INVALID_SERVER_HEADERS_RESPONSE,
+                  strlen(INVALID_SERVER_HEADERS_RESPONSE));
+               free_http_request(http);
+               mark_server_socket_tainted(csp);
+               return;
             }
             hdr = list_to_text(csp->headers);
             if (hdr == NULL)
@@ -2375,119 +2560,438 @@ static void chat(struct client_state *csp)
                log_error(LOG_LEVEL_FATAL, "Out of memory parsing server header");
             }
 
-            if ((csp->flags & CSP_FLAG_CHUNKED)
-               && !(csp->flags & CSP_FLAG_CONTENT_LENGTH_SET)
-               && ((csp->iob->eod - csp->iob->cur) >= 5)
-               && !memcmp(csp->iob->eod-5, "0\r\n\r\n", 5))
-            {
-               log_error(LOG_LEVEL_CONNECT,
-                  "Looks like we got the last chunk together with "
-                  "the server headers. We better stop reading.");
-               byte_count = (unsigned long long)(csp->iob->eod - csp->iob->cur);
-               csp->expected_content_length = byte_count;
-               csp->flags |= CSP_FLAG_CONTENT_LENGTH_SET;
-            }
+            if ((csp->flags & CSP_FLAG_CHUNKED)
+               && !(csp->flags & CSP_FLAG_CONTENT_LENGTH_SET)
+               && ((csp->iob->eod - csp->iob->cur) >= 5)
+               && !memcmp(csp->iob->eod-5, "0\r\n\r\n", 5))
+            {
+               log_error(LOG_LEVEL_CONNECT,
+                  "Looks like we got the last chunk together with "
+                  "the server headers. We better stop reading.");
+               byte_count = (unsigned long long)(csp->iob->eod - csp->iob->cur);
+               csp->expected_content_length = byte_count;
+               csp->flags |= CSP_FLAG_CONTENT_LENGTH_SET;
+            }
+
+            csp->server_connection.response_received = time(NULL);
+
+            if (crunch_response_triggered(csp, crunchers_light))
+            {
+               /*
+                * One of the tags created by a server-header
+                * tagger triggered a crunch. We already
+                * delivered the crunch response to the client
+                * and are done here after cleaning up.
+                */
+                freez(hdr);
+                mark_server_socket_tainted(csp);
+                return;
+            }
+            /* Buffer and pcrs filter this if appropriate. */
+
+            if (!http->ssl) /* We talk plaintext */
+            {
+               buffer_and_filter_content = content_requires_filtering(csp);
+            }
+            /*
+             * Only write if we're not buffering for content modification
+             */
+            if (!buffer_and_filter_content)
+            {
+               /*
+                * Write the server's (modified) header to
+                * the client (along with anything else that
+                * may be in the buffer)
+                */
+
+               if (write_socket(csp->cfd, hdr, strlen(hdr))
+                || ((len = flush_socket(csp->cfd, csp->iob)) < 0))
+               {
+                  log_error(LOG_LEVEL_CONNECT, "write header to client failed: %E");
+
+                  /*
+                   * The write failed, so don't bother mentioning it
+                   * to the client... it probably can't hear us anyway.
+                   */
+                  freez(hdr);
+                  mark_server_socket_tainted(csp);
+                  return;
+               }
+            }
+
+            /* we're finished with the server's header */
+
+            freez(hdr);
+            server_body = 1;
+
+            /*
+             * If this was a MS IIS/5 hack then it means the server
+             * has already closed the connection. Nothing more to read.
+             * Time to bail.
+             */
+            if (ms_iis5_hack)
+            {
+               log_error(LOG_LEVEL_ERROR,
+                  "Closed server connection detected. "
+                  "Applying the MS IIS5 hack didn't help.");
+               log_error(LOG_LEVEL_CLF,
+                  "%s - - [%T] \"%s\" 502 0", csp->ip_addr_str, http->cmd);
+               write_socket(csp->cfd, INVALID_SERVER_HEADERS_RESPONSE,
+                  strlen(INVALID_SERVER_HEADERS_RESPONSE));
+               mark_server_socket_tainted(csp);
+               return;
+            }
+         }
+         continue;
+      }
+      mark_server_socket_tainted(csp);
+      return; /* huh? we should never get here */
+   }
+
+   if (csp->content_length == 0)
+   {
+      /*
+       * If Privoxy didn't recalculate the Content-Length,
+       * byte_count is still correct.
+       */
+      csp->content_length = byte_count;
+   }
+
+#ifdef FEATURE_CONNECTION_KEEP_ALIVE
+   if ((csp->flags & CSP_FLAG_CONTENT_LENGTH_SET)
+      && (csp->expected_content_length != byte_count))
+   {
+      log_error(LOG_LEVEL_CONNECT,
+         "Received %llu bytes while expecting %llu.",
+         byte_count, csp->expected_content_length);
+      mark_server_socket_tainted(csp);
+   }
+#endif
+
+   log_error(LOG_LEVEL_CLF, "%s - - [%T] \"%s\" 200 %llu",
+      csp->ip_addr_str, http->ocmd, csp->content_length);
+
+   csp->server_connection.timestamp = time(NULL);
+}
+
+
+/*********************************************************************
+ *
+ * Function    :  chat
+ *
+ * Description :  Once a connection from the client has been accepted,
+ *                this function is called (via serve()) to handle the
+ *                main business of the communication.  This function
+ *                returns after dealing with a single request. It can
+ *                be called multiple times with the same client socket
+ *                if the client is keeping the connection alive.
+ *
+ *                The decision whether or not a client connection will
+ *                be kept alive is up to the caller which also must
+ *                close the client socket when done.
+ *
+ *                FIXME: chat is nearly thousand lines long.
+ *                Ridiculous.
+ *
+ * Parameters  :
+ *          1  :  csp = Current client state (buffers, headers, etc...)
+ *
+ * Returns     :  Nothing.
+ *
+ *********************************************************************/
+static void chat(struct client_state *csp)
+{
+   char buf[BUFFER_SIZE];
+   const struct forward_spec *fwd;
+   struct http_request *http;
+   /* Skeleton for HTTP response, if we should intercept the request */
+   struct http_response *rsp;
+
+   memset(buf, 0, sizeof(buf));
+
+   http = csp->http;
+
+   if (receive_client_request(csp) != JB_ERR_OK)
+   {
+      return;
+   }
+   if (parse_client_request(csp) != JB_ERR_OK)
+   {
+      return;
+   }
+
+   /* decide how to route the HTTP request */
+   fwd = forward_url(csp, http);
+   if (NULL == fwd)
+   {
+      log_error(LOG_LEVEL_FATAL, "gateway spec is NULL!?!?  This can't happen!");
+      /* Never get here - LOG_LEVEL_FATAL causes program exit */
+      return;
+   }
+
+   /*
+    * build the http request to send to the server
+    * we have to do one of the following:
+    *
+    * create = use the original HTTP request to create a new
+    *          HTTP request that has either the path component
+    *          without the http://domainspec (w/path) or the
+    *          full orininal URL (w/url)
+    *          Note that the path and/or the HTTP version may
+    *          have been altered by now.
+    *
+    * connect = Open a socket to the host:port of the server
+    *           and short-circuit server and client socket.
+    *
+    * pass =  Pass the request unchanged if forwarding a CONNECT
+    *         request to a parent proxy. Note that we'll be sending
+    *         the CFAIL message ourselves if connecting to the parent
+    *         fails, but we won't send a CSUCCEED message if it works,
+    *         since that would result in a double message (ours and the
+    *         parent's). After sending the request to the parent, we simply
+    *         tunnel.
+    *
+    * here's the matrix:
+    *                        SSL
+    *                    0        1
+    *                +--------+--------+
+    *                |        |        |
+    *             0  | create | connect|
+    *                | w/path |        |
+    *  Forwarding    +--------+--------+
+    *                |        |        |
+    *             1  | create | pass   |
+    *                | w/url  |        |
+    *                +--------+--------+
+    *
+    */
+
+   if (http->ssl && connect_port_is_forbidden(csp))
+   {
+      const char *acceptable_connect_ports =
+         csp->action->string[ACTION_STRING_LIMIT_CONNECT];
+      assert(NULL != acceptable_connect_ports);
+      log_error(LOG_LEVEL_INFO, "Request from %s marked for blocking. "
+         "limit-connect{%s} doesn't allow CONNECT requests to %s",
+         csp->ip_addr_str, acceptable_connect_ports, csp->http->hostport);
+      csp->action->flags |= ACTION_BLOCK;
+      http->ssl = 0;
+   }
+
+   if (http->ssl == 0)
+   {
+      freez(csp->headers->first->str);
+      build_request_line(csp, fwd, &csp->headers->first->str);
+   }
+
+   /*
+    * We have a request. Check if one of the crunchers wants it.
+    */
+   if (crunch_response_triggered(csp, crunchers_all))
+   {
+      /*
+       * Yes. The client got the crunch response and we're done here.
+       */
+      return;
+   }
+
+   log_applied_actions(csp->action);
+   log_error(LOG_LEVEL_GPC, "%s%s", http->hostport, http->path);
+
+   if (fwd->forward_host)
+   {
+      log_error(LOG_LEVEL_CONNECT, "via [%s]:%d to: %s",
+         fwd->forward_host, fwd->forward_port, http->hostport);
+   }
+   else
+   {
+      log_error(LOG_LEVEL_CONNECT, "to %s", http->hostport);
+   }
+
+   /* here we connect to the server, gateway, or the forwarder */
 
-            csp->server_connection.response_received = time(NULL);
+#ifdef FEATURE_CONNECTION_KEEP_ALIVE
+   if ((csp->server_connection.sfd != JB_INVALID_SOCKET)
+      && socket_is_still_alive(csp->server_connection.sfd)
+      && connection_destination_matches(&csp->server_connection, http, fwd))
+   {
+      log_error(LOG_LEVEL_CONNECT,
+         "Reusing server socket %d connected to %s. Total requests: %u.",
+         csp->server_connection.sfd, csp->server_connection.host,
+         csp->server_connection.requests_sent_total);
+   }
+   else
+   {
+      if (csp->server_connection.sfd != JB_INVALID_SOCKET)
+      {
+#ifdef FEATURE_CONNECTION_SHARING
+         if (csp->config->feature_flags & RUNTIME_FEATURE_CONNECTION_SHARING)
+         {
+            remember_connection(&csp->server_connection);
+         }
+         else
+#endif /* def FEATURE_CONNECTION_SHARING */
+         {
+            log_error(LOG_LEVEL_CONNECT,
+               "Closing server socket %d connected to %s. Total requests: %u.",
+               csp->server_connection.sfd, csp->server_connection.host,
+               csp->server_connection.requests_sent_total);
+            close_socket(csp->server_connection.sfd);
+         }
+         mark_connection_closed(&csp->server_connection);
+      }
+#endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
 
-            if (crunch_response_triggered(csp, crunchers_light))
-            {
-               /*
-                * One of the tags created by a server-header
-                * tagger triggered a crunch. We already
-                * delivered the crunch response to the client
-                * and are done here after cleaning up.
-                */
-                freez(hdr);
-                mark_server_socket_tainted(csp);
-                return;
-            }
-            /* Buffer and pcrs filter this if appropriate. */
+      csp->server_connection.sfd = forwarded_connect(fwd, http, csp);
 
-            if (!http->ssl) /* We talk plaintext */
-            {
-               buffer_and_filter_content = content_requires_filtering(csp);
-            }
-            /*
-             * Only write if we're not buffering for content modification
-             */
-            if (!buffer_and_filter_content)
-            {
-               /*
-                * Write the server's (modified) header to
-                * the client (along with anything else that
-                * may be in the buffer)
-                */
+      if (csp->server_connection.sfd == JB_INVALID_SOCKET)
+      {
+         if (fwd->type != SOCKS_NONE)
+         {
+            /* Socks error. */
+            rsp = error_response(csp, "forwarding-failed");
+         }
+         else if (errno == EINVAL)
+         {
+            rsp = error_response(csp, "no-such-domain");
+         }
+         else
+         {
+            rsp = error_response(csp, "connect-failed");
+         }
 
-               if (write_socket(csp->cfd, hdr, strlen(hdr))
-                || ((len = flush_socket(csp->cfd, csp->iob)) < 0))
-               {
-                  log_error(LOG_LEVEL_CONNECT, "write header to client failed: %E");
+         /* Write the answer to the client */
+         if (rsp != NULL)
+         {
+            send_crunch_response(csp, rsp);
+         }
 
-                  /*
-                   * The write failed, so don't bother mentioning it
-                   * to the client... it probably can't hear us anyway.
-                   */
-                  freez(hdr);
-                  mark_server_socket_tainted(csp);
-                  return;
-               }
-            }
+         /*
+          * Temporary workaround to prevent already-read client
+          * bodies from being parsed as new requests. For now we
+          * err on the safe side and throw all the following
+          * requests under the bus, even if no client body has been
+          * buffered. A compliant client will repeat the dropped
+          * requests on an untainted connection.
+          *
+          * The proper fix is to discard the no longer needed
+          * client body in the buffer (if there is one) and to
+          * continue parsing the bytes that follow.
+          */
+         drain_and_close_socket(csp->cfd);
+         csp->cfd = JB_INVALID_SOCKET;
 
-            /* we're finished with the server's header */
+         return;
+      }
+#ifdef FEATURE_CONNECTION_KEEP_ALIVE
+      save_connection_destination(csp->server_connection.sfd,
+         http, fwd, &csp->server_connection);
+      csp->server_connection.keep_alive_timeout =
+         (unsigned)csp->config->keep_alive_timeout;
+   }
+#endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
 
-            freez(hdr);
-            server_body = 1;
+   csp->server_connection.requests_sent_total++;
 
-            /*
-             * If this was a MS IIS/5 hack then it means the server
-             * has already closed the connection. Nothing more to read.
-             * Time to bail.
-             */
-            if (ms_iis5_hack)
-            {
-               log_error(LOG_LEVEL_ERROR,
-                  "Closed server connection detected. "
-                  "Applying the MS IIS5 hack didn't help.");
-               log_error(LOG_LEVEL_CLF,
-                  "%s - - [%T] \"%s\" 502 0", csp->ip_addr_str, http->cmd);
-               write_socket(csp->cfd, INVALID_SERVER_HEADERS_RESPONSE,
-                  strlen(INVALID_SERVER_HEADERS_RESPONSE));
-               mark_server_socket_tainted(csp);
-               return;
-            }
+   if ((fwd->type == SOCKS_5T) && (NULL == csp->headers->first))
+   {
+      /* Client headers have been sent optimistically */
+      assert(csp->headers->last == NULL);
+   }
+   else if (fwd->forward_host || (http->ssl == 0))
+   {
+      if (send_http_request(csp))
+      {
+         rsp = error_response(csp, "connect-failed");
+         if (rsp)
+         {
+            send_crunch_response(csp, rsp);
          }
-         continue;
+         return;
       }
-      mark_server_socket_tainted(csp);
-      return; /* huh? we should never get here */
    }
-
-   if (csp->content_length == 0)
+   else
    {
       /*
-       * If Privoxy didn't recalculate the Content-Length,
-       * byte_count is still correct.
+       * We're running an SSL tunnel and we're not forwarding,
+       * so just ditch the client headers, send the "connect succeeded"
+       * message to the client, flush the rest, and get out of the way.
        */
-      csp->content_length = byte_count;
+      list_remove_all(csp->headers);
+      if (write_socket(csp->cfd, CSUCCEED, strlen(CSUCCEED)))
+      {
+         return;
+      }
+      clear_iob(csp->client_iob);
    }
 
-#ifdef FEATURE_CONNECTION_KEEP_ALIVE
-   if ((csp->flags & CSP_FLAG_CONTENT_LENGTH_SET)
-      && (csp->expected_content_length != byte_count))
+   log_error(LOG_LEVEL_CONNECT, "to %s successful", http->hostport);
+
+   /* XXX: should the time start earlier for optimistically sent data? */
+   csp->server_connection.request_sent = time(NULL);
+
+   handle_established_connection(csp, fwd);
+}
+
+
+#ifdef FUZZ
+/*********************************************************************
+ *
+ * Function    :  fuzz_server_response
+ *
+ * Description :  Treat the input as a whole server response.
+ *
+ * Parameters  :
+ *          1  :  csp = Current client state (buffers, headers, etc...)
+ *          2  :  fuzz_input_file = File to read the input from.
+ *
+ * Returns     :  0
+ *
+ *********************************************************************/
+extern int fuzz_server_response(struct client_state *csp, char *fuzz_input_file)
+{
+   static struct forward_spec fwd; /* Zero'd due to being static */
+   csp->cfd = 0;
+
+   if (strcmp(fuzz_input_file, "-") == 0)
    {
-      log_error(LOG_LEVEL_CONNECT,
-         "Received %llu bytes while expecting %llu.",
-         byte_count, csp->expected_content_length);
-      mark_server_socket_tainted(csp);
+      /* XXX: Doesn'T work yet. */
+      csp->server_connection.sfd = 0;
    }
-#endif
+   else
+   {
+      csp->server_connection.sfd = open(fuzz_input_file, O_RDONLY);
+      if (csp->server_connection.sfd == -1)
+      {
+         log_error(LOG_LEVEL_FATAL, "Failed to open %s: %E",
+            fuzz_input_file);
+      }
+   }
+   csp->content_type |= CT_GIF;
+   csp->action->flags |= ACTION_DEANIMATE;
+   csp->action->string[ACTION_STRING_DEANIMATE] = "last";
 
-   log_error(LOG_LEVEL_CLF, "%s - - [%T] \"%s\" 200 %llu",
-      csp->ip_addr_str, http->ocmd, csp->content_length);
+   csp->http->path = strdup_or_die("/");
+   csp->http->host = strdup_or_die("fuzz.example.org");
+   csp->http->hostport = strdup_or_die("fuzz.example.org:80");
+   /* Prevent client socket monitoring */
+   csp->flags |= CSP_FLAG_PIPELINED_REQUEST_WAITING;
+   csp->flags |= CSP_FLAG_CHUNKED;
 
-   csp->server_connection.timestamp = time(NULL);
+   csp->config->feature_flags |= RUNTIME_FEATURE_CONNECTION_KEEP_ALIVE;
+   csp->flags |= CSP_FLAG_CLIENT_CONNECTION_KEEP_ALIVE;
+
+   csp->content_type |= CT_DECLARED|CT_GIF;
+
+   csp->config->socket_timeout = 0;
+
+   cgi_init_error_messages();
+
+   handle_established_connection(csp, &fwd);
+
+   return 0;
 }
+#endif
 
 
 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
@@ -2505,8 +3009,6 @@ static void chat(struct client_state *csp)
  *********************************************************************/
 static void prepare_csp_for_next_request(struct client_state *csp)
 {
-   unsigned int toggled_on_flag_set = (0 != (csp->flags & CSP_FLAG_TOGGLED_ON));
-
    csp->content_type = 0;
    csp->content_length = 0;
    csp->expected_content_length = 0;
@@ -2517,6 +3019,10 @@ static void prepare_csp_for_next_request(struct client_state *csp)
    free_http_request(csp->http);
    destroy_list(csp->headers);
    destroy_list(csp->tags);
+#ifdef FEATURE_CLIENT_TAGS
+   destroy_list(csp->client_tags);
+   freez(csp->client_address);
+#endif
    free_current_action(csp->action);
    if (NULL != csp->fwd)
    {
@@ -2525,7 +3031,9 @@ static void prepare_csp_for_next_request(struct client_state *csp)
    }
    /* XXX: Store per-connection flags someplace else. */
    csp->flags = (CSP_FLAG_ACTIVE | CSP_FLAG_REUSED_CLIENT_CONNECTION);
-   if (toggled_on_flag_set)
+#ifdef FEATURE_TOGGLE
+   if (global_toggle_state)
+#endif /* def FEATURE_TOGGLE */
    {
       csp->flags |= CSP_FLAG_TOGGLED_ON;
    }
@@ -2584,12 +3092,12 @@ void serve(struct client_state *csp)
 static void serve(struct client_state *csp)
 #endif /* def AMIGA */
 {
+   int config_file_change_detected = 0; /* Only used for debugging */
 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
 #ifdef FEATURE_CONNECTION_SHARING
    static int monitor_thread_running = 0;
 #endif /* def FEATURE_CONNECTION_SHARING */
    int continue_chatting = 0;
-   int config_file_change_detected = 0; /* Only used for debugging */
 
    log_error(LOG_LEVEL_CONNECT, "Accepted connection from %s on socket %d",
       csp->ip_addr_str, csp->cfd);
@@ -2620,9 +3128,9 @@ static void serve(struct client_state *csp)
          & RUNTIME_FEATURE_CONNECTION_KEEP_ALIVE)
          && !(csp->flags & CSP_FLAG_SERVER_SOCKET_TAINTED)
          && (csp->cfd != JB_INVALID_SOCKET)
-         && ((csp->flags & CSP_FLAG_CLIENT_CONNECTION_KEEP_ALIVE)
-             || (csp->config->feature_flags &
-                RUNTIME_FEATURE_CONNECTION_SHARING));
+         && (csp->flags & CSP_FLAG_CLIENT_CONNECTION_KEEP_ALIVE)
+         && ((csp->flags & CSP_FLAG_SERVER_CONTENT_LENGTH_SET)
+            || (csp->flags & CSP_FLAG_CHUNKED));
 
       if (!(csp->flags & CSP_FLAG_CRUNCHED)
          && (csp->server_connection.sfd != JB_INVALID_SOCKET))
@@ -2637,14 +3145,13 @@ static void serve(struct client_state *csp)
             || !(latency < csp->server_connection.keep_alive_timeout))
          {
             log_error(LOG_LEVEL_CONNECT,
-               "Closing connection on server socket %d to %s: "
-               "keep-alive %u, tainted: %u, socket alive %u. %s timeout: %u.",
+               "Closing server socket %d connected to %s. "
+               "Keep-alive %u. Tainted: %u. Socket alive %u. Timeout: %u.",
                csp->server_connection.sfd, csp->server_connection.host,
                0 != (csp->flags & CSP_FLAG_SERVER_CONNECTION_KEEP_ALIVE),
                0 != (csp->flags & CSP_FLAG_SERVER_SOCKET_TAINTED),
                socket_is_still_alive(csp->server_connection.sfd),
-               ((csp->flags & CSP_FLAG_SERVER_KEEP_ALIVE_TIMEOUT_SET) ?
-               "Specified" : "Assumed"), csp->server_connection.keep_alive_timeout);
+               csp->server_connection.keep_alive_timeout);
 #ifdef FEATURE_CONNECTION_SHARING
             if (csp->config->feature_flags & RUNTIME_FEATURE_CONNECTION_SHARING)
             {
@@ -2656,7 +3163,7 @@ static void serve(struct client_state *csp)
          }
       }
 
-      if (continue_chatting && any_loaded_file_changed(csp->config->config_file_list))
+      if (continue_chatting && any_loaded_file_changed(csp))
       {
          continue_chatting = 0;
          config_file_change_detected = 1;
@@ -2736,8 +3243,8 @@ static void serve(struct client_state *csp)
       else if (csp->server_connection.sfd != JB_INVALID_SOCKET)
       {
          log_error(LOG_LEVEL_CONNECT,
-            "Closing server socket %d connected to %s. Keep-alive %u. "
-            "Tainted: %u. Socket alive %u. Timeout: %u. "
+            "Closing server socket %d connected to %s. Keep-alive: %u. "
+            "Tainted: %u. Socket alive: %u. Timeout: %u. "
             "Configuration file change detected: %u",
             csp->server_connection.sfd, csp->server_connection.host,
             0 != (csp->flags & CSP_FLAG_SERVER_CONNECTION_KEEP_ALIVE),
@@ -2770,7 +3277,7 @@ static void serve(struct client_state *csp)
    if (csp->cfd != JB_INVALID_SOCKET)
    {
       log_error(LOG_LEVEL_CONNECT, "Closing client socket %d. "
-         "Keep-alive: %u, Socket alive: %u. Data available: %u. "
+         "Keep-alive: %u. Socket alive: %u. Data available: %u. "
          "Configuration file change detected: %u. Requests received: %u.",
          csp->cfd, 0 != (csp->flags & CSP_FLAG_CLIENT_CONNECTION_KEEP_ALIVE),
          socket_is_still_alive(csp->cfd), data_is_available(csp->cfd, 0),
@@ -2817,10 +3324,10 @@ static int32 server_thread(void *data)
  * Returns     :  No. ,-)
  *
  *********************************************************************/
-static void usage(const char *myname)
+static void usage(const char *name)
 {
    printf("Privoxy version " VERSION " (" HOME_PAGE_URL ")\n"
-          "Usage: %s "
+          "Usage: %s [--config-test] "
 #if defined(unix)
           "[--chroot] "
 #endif /* defined(unix) */
@@ -2828,8 +3335,14 @@ static void usage(const char *myname)
 #if defined(unix)
           "[--no-daemon] [--pidfile pidfile] [--pre-chroot-nslookup hostname] [--user user[.group]] "
 #endif /* defined(unix) */
-          "[--version] [configfile]\n"
-          "Aborting\n", myname);
+         "[--version] [configfile]\n",
+          name);
+
+#ifdef FUZZ
+   show_fuzz_usage(name);
+#endif
+
+   printf("Aborting\n");
 
    exit(2);
 
@@ -2948,6 +3461,12 @@ static void initialize_mutexes(void)
    privoxy_mutex_init(&log_mutex);
    privoxy_mutex_init(&log_init_mutex);
    privoxy_mutex_init(&connection_reuse_mutex);
+#ifdef FEATURE_EXTERNAL_FILTERS
+   privoxy_mutex_init(&external_filter_mutex);
+#endif
+#ifdef FEATURE_CLIENT_TAGS
+   privoxy_mutex_init(&client_tags_mutex);
+#endif
 
    /*
     * XXX: The assumptions below are a bit naive
@@ -2979,7 +3498,6 @@ static void initialize_mutexes(void)
 #endif /* def MUTEX_LOCKS_AVAILABLE */
 }
 
-
 /*********************************************************************
  *
  * Function    :  main
@@ -3010,6 +3528,7 @@ int main(int argc, char **argv)
 #endif
 {
    int argc_pos = 0;
+   int do_config_test = 0;
    unsigned int random_seed;
 #ifdef unix
    struct passwd *pw = NULL;
@@ -3017,6 +3536,10 @@ int main(int argc, char **argv)
    int do_chroot = 0;
    char *pre_chroot_nslookup_to_load_resolver = NULL;
 #endif
+#ifdef FUZZ
+   char *fuzz_input_type = NULL;
+   char *fuzz_input_file = NULL;
+#endif
 
    Argc = argc;
    Argv = argv;
@@ -3140,6 +3663,24 @@ int main(int argc, char **argv)
       }
 #endif /* defined(unix) */
 
+      else if (strcmp(argv[argc_pos], "--config-test") == 0)
+      {
+         do_config_test = 1;
+      }
+#ifdef FUZZ
+      else if (strcmp(argv[argc_pos], "--fuzz") == 0)
+      {
+         argc_pos++;
+         if (argc < argc_pos + 2) usage(argv[0]);
+         fuzz_input_type = argv[argc_pos];
+         argc_pos++;
+         fuzz_input_file = argv[argc_pos];
+      }
+      else if (strcmp(argv[argc_pos], "--stfu") == 0)
+      {
+         set_debug_level(LOG_LEVEL_STFU);
+      }
+#endif
       else if (argc_pos + 1 != argc)
       {
          /*
@@ -3208,7 +3749,10 @@ int main(int argc, char **argv)
     *
     * Catch the abort, interrupt and terminate signals for a graceful exit
     * Catch the hangup signal so the errlog can be reopened.
-    * Ignore the broken pipe signals (FIXME: Why?)
+    *
+    * Ignore the broken pipe signal as connection failures
+    * are handled when and where they occur without relying
+    * on a signal.
     */
 #if !defined(_WIN32) && !defined(__OS2__) && !defined(AMIGA)
 {
@@ -3243,12 +3787,23 @@ int main(int argc, char **argv)
 # endif /* def _WIN_CONSOLE */
 #endif /* def _WIN32 */
 
+#ifdef FUZZ
+   if (fuzz_input_type != NULL)
+   {
+      exit(process_fuzzed_input(fuzz_input_type, fuzz_input_file));
+   }
+#endif
+
+   if (do_config_test)
+   {
+      exit(NULL == load_config());
+   }
 
    /* Initialize the CGI subsystem */
    cgi_init_error_messages();
 
    /*
-    * If runnig on unix and without the --nodaemon
+    * If running on unix and without the --no-daemon
     * option, become a daemon. I.e. fork, detach
     * from tty and get process group leadership
     */
@@ -3322,6 +3877,13 @@ int main(int argc, char **argv)
          close(fd);
       }
 
+#ifdef FEATURE_EXTERNAL_FILTERS
+      for (fd = 0; fd < 3; fd++)
+      {
+         mark_socket_for_close_on_execute(fd);
+      }
+#endif
+
       chdir("/");
 
    } /* -END- if (daemon_mode) */
@@ -3447,7 +4009,7 @@ int main(int argc, char **argv)
  *                on failure.
  *
  * Parameters  :
- *          1  :  haddr = Host addres to bind to. Use NULL to bind to
+ *          1  :  haddr = Host address to bind to. Use NULL to bind to
  *                        INADDR_ANY.
  *          2  :  hport = Specifies port to bind to.
  *
@@ -3486,6 +4048,15 @@ static jb_socket bind_port_helper(const char *haddr, int hport)
       return JB_INVALID_SOCKET;
    }
 
+#ifndef _WIN32
+   if (bfd >= FD_SETSIZE)
+   {
+      log_error(LOG_LEVEL_FATAL,
+         "Bind socket number too high to use select(): %d >= %d",
+         bfd, FD_SETSIZE);
+   }
+#endif
+
    if (haddr == NULL)
    {
       log_error(LOG_LEVEL_INFO, "Listening on port %d on all IP addresses",
@@ -3642,16 +4213,18 @@ static void listen_loop(void)
       }
 #endif
 
-      csp_list = (struct client_states *)zalloc(sizeof(*csp_list));
-      if (NULL == csp_list)
-      {
-         log_error(LOG_LEVEL_FATAL,
-            "malloc(%d) for csp_list failed: %E", sizeof(*csp_list));
-         continue;
-      }
+      csp_list = zalloc_or_die(sizeof(*csp_list));
       csp = &csp_list->csp;
 
-      log_error(LOG_LEVEL_CONNECT, "Listening for new connections ... ");
+      log_error(LOG_LEVEL_CONNECT,
+         "Waiting for the next client connection. Currently active threads: %d",
+         active_threads);
+
+      /*
+       * This config may be outdated, but for accept_connection()
+       * it's fresh enough.
+       */
+      csp->config = config;
 
       if (!accept_connection(csp, bfds))
       {
@@ -3709,9 +4282,11 @@ static void listen_loop(void)
       if (block_acl(NULL,csp))
       {
          log_error(LOG_LEVEL_CONNECT,
-            "Connection from %s on socket %d dropped due to ACL", csp->ip_addr_str, csp->cfd);
+            "Connection from %s on %s (socket %d) dropped due to ACL",
+            csp->ip_addr_str, csp->listen_addr_str, csp->cfd);
          close_socket(csp->cfd);
          freez(csp->ip_addr_str);
+         freez(csp->listen_addr_str);
          freez(csp_list);
          continue;
       }
@@ -3727,6 +4302,7 @@ static void listen_loop(void)
             strlen(TOO_MANY_CONNECTIONS_RESPONSE));
          close_socket(csp->cfd);
          freez(csp->ip_addr_str);
+         freez(csp->listen_addr_str);
          freez(csp_list);
          continue;
       }
@@ -3905,7 +4481,8 @@ static void listen_loop(void)
              * XXX: If you assume ...
              */
             log_error(LOG_LEVEL_ERROR,
-               "Unable to take any additional connections: %E");
+               "Unable to take any additional connections: %E. Active threads: %d",
+               active_threads);
             write_socket(csp->cfd, TOO_MANY_CONNECTIONS_RESPONSE,
                strlen(TOO_MANY_CONNECTIONS_RESPONSE));
             close_socket(csp->cfd);