When client body filters are enabled, buffer the whole request
authorFabian Keil <fk@fabiankeil.de>
Sat, 27 Mar 2021 07:20:59 +0000 (08:20 +0100)
committerFabian Keil <fk@fabiankeil.de>
Tue, 26 Apr 2022 14:51:25 +0000 (16:51 +0200)
... before opening a connection to the server.

Makes it less likely that the server connection times out
and we don't open a connection if the buffering fails anyway.

Sponsored by: Robert Klemme

filters.c
filters.h
jcc.c

index 48259a8..2dd6503 100644 (file)
--- a/filters.c
+++ b/filters.c
@@ -2407,21 +2407,20 @@ char *execute_content_filters(struct client_state *csp)
  * Function    :  execute_client_body_filters
  *
  * Description :  Executes client body filters for the request that is buffered
- *                in the client_iob. Upon success moves client_iob cur pointer
- *                to the end of the processed data.
+ *                in the client_iob. The client_iob is updated with the filtered
+ *                content.
  *
  * Parameters  :
  *          1  :  csp = Current client state (buffers, headers, etc...)
  *          2  :  content_length = content length. Upon successful filtering
  *                the passed value is updated with the new content length.
  *
- * Returns     :  Pointer to the modified buffer, or
- *                NULL if filtering failed or wasn't necessary.
+ * Returns     :  1 if the content has been filterd. 0 if it hasn't.
  *
  *********************************************************************/
-char *execute_client_body_filters(struct client_state *csp, size_t *content_length)
+int execute_client_body_filters(struct client_state *csp, size_t *content_length)
 {
-   char *ret;
+   char *filtered_content;
 
    assert(client_body_filters_enabled(csp->action));
 
@@ -2430,15 +2429,22 @@ char *execute_client_body_filters(struct client_state *csp, size_t *content_leng
       /*
        * No content, no filtering necessary.
        */
-      return NULL;
+      return 0;
    }
 
-   ret = pcrs_filter_request_body(csp, csp->client_iob->cur, content_length);
-   if (ret != NULL)
+   filtered_content = pcrs_filter_request_body(csp, csp->client_iob->cur, content_length);
+   if (filtered_content != NULL)
    {
-      csp->client_iob->cur = csp->client_iob->eod;
+      freez(csp->client_iob->buf);
+      csp->client_iob->buf  = filtered_content;
+      csp->client_iob->cur  = csp->client_iob->buf;
+      csp->client_iob->eod  = csp->client_iob->cur + *content_length;
+      csp->client_iob->size = *content_length;
+
+      return 1;
    }
-   return ret;
+   
+   return 0;
 }
 
 
index e16a3ea..829a167 100644 (file)
--- a/filters.h
+++ b/filters.h
@@ -84,7 +84,7 @@ extern const struct forward_spec *forward_url(struct client_state *csp,
  * Content modification
  */
 extern char *execute_content_filters(struct client_state *csp);
-extern char *execute_client_body_filters(struct client_state *csp, size_t *filtered_data_len);
+extern int execute_client_body_filters(struct client_state *csp, size_t *content_length);
 extern char *execute_single_pcrs_command(char *subject, const char *pcrs_command, int *hits);
 extern char *rewrite_url(char *old_url, const char *pcrs_command);
 
diff --git a/jcc.c b/jcc.c
index f4dc57d..81222a4 100644 (file)
--- a/jcc.c
+++ b/jcc.c
@@ -288,6 +288,13 @@ static const char CLIENT_BODY_PARSE_ERROR_RESPONSE[] =
    "Connection: close\r\n\r\n"
    "Failed parsing or buffering the chunk-encoded client body.\n";
 
+static const char CLIENT_BODY_BUFFER_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 to buffer the client body to apply content filters.\n"
+   "Could be caused by a socket timeout\n";
+
 static const char UNSUPPORTED_CLIENT_EXPECTATION_ERROR_RESPONSE[] =
    "HTTP/1.1 417 Expecting too much\r\n"
    "Content-Type: text/plain\r\n"
@@ -2210,33 +2217,6 @@ static int send_http_request(struct client_state *csp)
 {
    char *hdr;
    int write_failure;
-   const char *to_send;
-   size_t to_send_len;
-   int filter_client_body = csp->expected_client_content_length != 0 &&
-      client_body_filters_enabled(csp->action) && can_filter_request_body(csp);
-
-   if (filter_client_body)
-   {
-      if (read_http_request_body(csp))
-      {
-         return 1;
-      }
-      to_send_len = csp->expected_client_content_length;
-      to_send = execute_client_body_filters(csp, &to_send_len);
-      if (to_send == NULL)
-      {
-         /* just flush client_iob */
-         filter_client_body = FALSE;
-      }
-      else if (to_send_len != csp->expected_client_content_length &&
-         update_client_headers(csp, to_send_len))
-      {
-         log_error(LOG_LEVEL_HEADER, "Error updating client headers");
-         freez(to_send);
-         return 1;
-      }
-      csp->expected_client_content_length = 0;
-   }
 
    hdr = list_to_text(csp->headers);
    if (hdr == NULL)
@@ -2257,25 +2237,10 @@ static int send_http_request(struct client_state *csp)
    {
       log_error(LOG_LEVEL_CONNECT, "Failed sending request headers to: %s: %E",
          csp->http->hostport);
-      if (filter_client_body)
-      {
-         freez(to_send);
-      }
       return 1;
    }
 
-   if (filter_client_body)
-   {
-      write_failure = 0 != write_socket(csp->server_connection.sfd, to_send, to_send_len);
-      freez(to_send);
-      if (write_failure)
-      {
-         log_error(LOG_LEVEL_CONNECT, "Failed sending filtered request body to: %s: %E",
-            csp->http->hostport);
-         return 1;
-      }
-   }
-
+   /* XXX: Filtered data is not sent if there's a pipelined request? */
    if (((csp->flags & CSP_FLAG_PIPELINED_REQUEST_WAITING) == 0)
       && (flush_iob(csp->server_connection.sfd, csp->client_iob, 0) < 0))
    {
@@ -2444,32 +2409,6 @@ static int send_https_request(struct client_state *csp)
    char *hdr;
    int ret;
    long flushed = 0;
-   const char *to_send;
-   size_t to_send_len;
-   int filter_client_body = csp->expected_client_content_length != 0 &&
-      client_body_filters_enabled(csp->action) && can_filter_request_body(csp);
-
-   if (filter_client_body)
-   {
-      if (read_https_request_body(csp))
-      {
-         return 1;
-      }
-      to_send_len = csp->expected_client_content_length;
-      to_send = execute_client_body_filters(csp, &to_send_len);
-      if (to_send == NULL)
-      {
-         /* just flush client_iob */
-         filter_client_body = FALSE;
-      }
-      else if (to_send_len != csp->expected_client_content_length &&
-         update_client_headers(csp, to_send_len))
-      {
-         log_error(LOG_LEVEL_HEADER, "Error updating client headers");
-         return 1;
-      }
-      csp->expected_client_content_length = 0;
-   }
 
    hdr = list_to_text(csp->https_headers);
    if (hdr == NULL)
@@ -2496,18 +2435,7 @@ static int send_https_request(struct client_state *csp)
       return 1;
    }
 
-   if (filter_client_body)
-   {
-      ret = ssl_send_data(&(csp->ssl_server_attr), (const unsigned char *)to_send, to_send_len);
-      freez(to_send);
-      if (ret < 0)
-      {
-         log_error(LOG_LEVEL_CONNECT, "Failed sending filtered request body to: %s",
-            csp->http->hostport);
-         return 1;
-      }
-   }
-
+   /* XXX: Client body isn't sent if there's pipelined data? */
    if (((csp->flags & CSP_FLAG_PIPELINED_REQUEST_WAITING) == 0)
       && ((flushed = ssl_flush_socket(&(csp->ssl_server_attr),
             csp->client_iob)) < 0))
@@ -3010,6 +2938,32 @@ static void continue_https_chat(struct client_state *csp)
    }
    assert(csp->server_connection.sfd != JB_INVALID_SOCKET);
 
+   if (csp->expected_client_content_length != 0 &&
+      client_body_filters_enabled(csp->action) &&
+      can_filter_request_body(csp))
+   {
+      int content_modified;
+      size_t buffered_content_length;
+
+      if (read_https_request_body(csp))
+      {
+         /* XXX: handle */
+         return;
+      }
+      buffered_content_length = csp->expected_client_content_length;
+      content_modified  = execute_client_body_filters(csp, &buffered_content_length);
+      if ((content_modified == 1) &&
+         (buffered_content_length != csp->expected_client_content_length) &&
+         update_client_headers(csp, buffered_content_length))
+      {
+         log_error(LOG_LEVEL_HEADER, "Failed to update client headers "
+            "after filtering the encrypted client body");
+         /* XXX: handle */
+         return;
+      }
+      csp->expected_client_content_length = 0;
+   }
+
    fwd = forward_url(csp, csp->http);
    if (!connection_destination_matches(&csp->server_connection, csp->http, fwd))
    {
@@ -4406,6 +4360,56 @@ static void chat(struct client_state *csp)
    }
 #endif
 
+   /* If we need to apply client body filters, buffer the whole request now. */
+   if (csp->expected_client_content_length != 0 &&
+      client_body_filters_enabled(csp->action) && can_filter_request_body(csp))
+   {
+      int content_modified;
+      size_t modified_content_length;
+
+#ifdef FEATURE_HTTPS_INSPECTION
+      if (client_use_ssl(csp) && read_https_request_body(csp))
+      {
+         log_error(LOG_LEVEL_ERROR,
+            "Failed to buffer the encrypted request body to apply filters");
+         log_error(LOG_LEVEL_CLF,
+            "%s - - [%T] \"%s\" 400 0", csp->ip_addr_str, csp->http->cmd);
+
+         ssl_send_data_delayed(&(csp->ssl_client_attr),
+            (const unsigned char *)CLIENT_BODY_BUFFER_ERROR_RESPONSE,
+            strlen(CLIENT_BODY_BUFFER_ERROR_RESPONSE),
+            get_write_delay(csp));
+
+         return;
+      }
+      else
+#endif
+      if (read_http_request_body(csp))
+      {
+         log_error(LOG_LEVEL_ERROR,
+            "Failed to buffer the request body to apply filters");
+         log_error(LOG_LEVEL_CLF,
+            "%s - - [%T] \"%s\" 400 0", csp->ip_addr_str, csp->http->cmd);
+
+         write_socket_delayed(csp->cfd, CLIENT_BODY_BUFFER_ERROR_RESPONSE,
+            strlen(CLIENT_BODY_BUFFER_ERROR_RESPONSE), get_write_delay(csp));
+
+         return;
+      }
+      modified_content_length = csp->expected_client_content_length;
+      content_modified = execute_client_body_filters(csp,
+         &modified_content_length);
+      if ((content_modified == 1) &&
+         (modified_content_length != csp->expected_client_content_length) &&
+         update_client_headers(csp, modified_content_length))
+      {
+         /* XXX: Send error response */
+         log_error(LOG_LEVEL_HEADER, "Error updating client headers");
+         return;
+      }
+      csp->expected_client_content_length = 0;
+   }
+
    log_applied_actions(csp->action);
 
    /* decide how to route the HTTP request */