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- /*
- * Copyright (C) 2017 Michael Brown <mbrown@fensystems.co.uk>.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License as
- * published by the Free Software Foundation; either version 2 of the
- * License, or any later version.
- *
- * This program is distributed in the hope that it will be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
- * 02110-1301, USA.
- *
- * You can also choose to distribute this program under the terms of
- * the Unmodified Binary Distribution Licence (as given in the file
- * COPYING.UBDL), provided that you have satisfied its requirements.
- */
-
- FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
-
- /**
- * @file
- *
- * Google Compute Engine (GCE) metadata retrieval
- *
- * For some unspecified "security" reason, the Google Compute Engine
- * metadata server will refuse any requests that do not include the
- * non-standard HTTP header "Metadata-Flavor: Google".
- */
-
- #include <strings.h>
- #include <stdio.h>
- #include <ipxe/http.h>
-
- /** Metadata host name
- *
- * This is used to identify metadata requests, in the absence of any
- * more robust mechanism.
- */
- #define GCE_METADATA_HOST_NAME "metadata.google.internal"
-
- /**
- * Construct HTTP "Metadata-Flavor" header
- *
- * @v http HTTP transaction
- * @v buf Buffer
- * @v len Length of buffer
- * @ret len Length of header value, or negative error
- */
- static int http_format_metadata_flavor ( struct http_transaction *http,
- char *buf, size_t len ) {
-
- /* Do nothing unless this appears to be a Google Compute
- * Engine metadata request.
- */
- if ( strcasecmp ( http->request.host, GCE_METADATA_HOST_NAME ) != 0 )
- return 0;
-
- /* Construct host URI */
- return snprintf ( buf, len, "Google" );
- }
-
- /** HTTP "Metadata-Flavor" header */
- struct http_request_header http_request_metadata_flavor __http_request_header ={
- .name = "Metadata-Flavor",
- .format = http_format_metadata_flavor,
- };
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