[zlib] Add support for zlib archive images

Signed-off-by: Michael Brown <mcb30@ipxe.org>

1 files changed, 162 insertions, 0 deletions

diff --git a/src/image/zlib.c b/src/image/zlib.c
new file mode 100644
index 00000000..bc27142d
--- /dev/null
+++ b/src/image/zlib.c
@@ -0,0 +1,162 @@
+/*
+ * Copyright (C) 2021 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 );
+
+#include <stdlib.h>
+#include <errno.h>
+#include <assert.h>
+#include <ipxe/deflate.h>
+#include <ipxe/uaccess.h>
+#include <ipxe/image.h>
+#include <ipxe/zlib.h>
+
+/** @file
+ *
+ * zlib compressed images
+ *
+ */
+
+/**
+ * Extract compressed data to image
+ *
+ * @v format		Compression format code
+ * @v in		Compressed input chunk
+ * @v extracted		Extracted image
+ * @ret rc		Return status code
+ */
+int zlib_deflate ( enum deflate_format format, struct deflate_chunk *in,
+		   struct image *extracted ) {
+	struct deflate *deflate;
+	struct deflate_chunk out;
+	int rc;
+
+	/* Allocate and initialise decompressor */
+	deflate = zalloc ( sizeof ( *deflate ) );
+	if ( ! deflate ) {
+		rc = -ENOMEM;
+		goto err_alloc;
+	}
+
+	/* Decompress data, (re)allocating if necessary */
+	while ( 1 ) {
+
+		/* (Re)initialise decompressor */
+		deflate_init ( deflate, format );
+
+		/* (Re)initialise input chunk */
+		in->offset = 0;
+
+		/* Initialise output chunk */
+		deflate_chunk_init ( &out, extracted->data, 0, extracted->len );
+
+		/* Decompress data */
+		if ( ( rc = deflate_inflate ( deflate, in, &out ) ) != 0 ) {
+			DBGC ( extracted, "ZLIB %p could not decompress: %s\n",
+			       extracted, strerror ( rc ) );
+			goto err_inflate;
+		}
+
+		/* Check that decompression is valid */
+		if ( ! deflate_finished ( deflate ) ) {
+			DBGC ( extracted, "ZLIB %p decompression incomplete\n",
+			       extracted );
+			rc = -EINVAL;
+			goto err_unfinished;
+		}
+
+		/* Finish if output image size was correct */
+		if ( out.offset == extracted->len )
+			break;
+
+		/* Otherwise, resize output image and retry */
+		if ( ( rc = image_set_len ( extracted, out.offset ) ) != 0 ) {
+			DBGC ( extracted, "ZLIB %p could not resize: %s\n",
+			       extracted, strerror ( rc ) );
+			goto err_set_size;
+		}
+	}
+
+	/* Success */
+	rc = 0;
+
+ err_set_size:
+ err_unfinished:
+ err_inflate:
+	free ( deflate );
+ err_alloc:
+	return rc;
+}
+
+/**
+ * Extract zlib image
+ *
+ * @v image		Image
+ * @v extracted		Extracted image
+ * @ret rc		Return status code
+ */
+static int zlib_extract ( struct image *image, struct image *extracted ) {
+	struct deflate_chunk in;
+	int rc;
+
+	/* Initialise input chunk */
+	deflate_chunk_init ( &in, image->data, 0, image->len );
+
+	/* Decompress image */
+	if ( ( rc = zlib_deflate ( DEFLATE_ZLIB, &in, extracted ) ) != 0 )
+		return rc;
+
+	return 0;
+}
+
+/**
+ * Probe zlib image
+ *
+ * @v image		zlib image
+ * @ret rc		Return status code
+ */
+static int zlib_probe ( struct image *image ) {
+	union zlib_magic magic;
+
+	/* Sanity check */
+	if ( image->len < sizeof ( magic ) ) {
+		DBGC ( image, "ZLIB %p image too short\n", image );
+		return -ENOEXEC;
+	}
+
+	/* Check magic header */
+	copy_from_user ( &magic, image->data, 0, sizeof ( magic ) );
+	if ( ! zlib_magic_is_valid ( &magic ) ) {
+		DBGC ( image, "ZLIB %p invalid magic data\n", image );
+		return -ENOEXEC;
+	}
+
+	return 0;
+}
+
+/** zlib image type */
+struct image_type zlib_image_type __image_type ( PROBE_NORMAL ) = {
+	.name = "zlib",
+	.probe = zlib_probe,
+	.extract = zlib_extract,
+};