From patchwork Sat Dec 27 15:01:40 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peter Wu X-Patchwork-Id: 424214 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 46E881400D5 for ; Sun, 28 Dec 2014 02:07:06 +1100 (AEDT) Received: from localhost ([::1]:56199 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Y4sxM-0000y0-CL for incoming@patchwork.ozlabs.org; Sat, 27 Dec 2014 10:07:04 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:35475) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Y4ssP-0006In-1T for qemu-devel@nongnu.org; Sat, 27 Dec 2014 10:01:58 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Y4ssI-0000OX-TN for qemu-devel@nongnu.org; Sat, 27 Dec 2014 10:01:56 -0500 Received: from mail.lekensteyn.nl ([2a02:2308::360:1:25]:50110) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Y4ssI-0000Nt-NA for qemu-devel@nongnu.org; Sat, 27 Dec 2014 10:01:50 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lekensteyn.nl; s=s2048-2014-q3; h=References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From; bh=AUkxSQ2p7yncCMuehMvi2FvCfR6ThIIPUjzpH1gQQw4=; b=pJKW0YB7HDGfBZePe3OmDYegvqpUX0NBrSaUsytE543crflP7pMGF/j0DjiCZCSZDrTe64XdV17Yy7BPSMDhMC32C1vrhLEraMrCWeOTdenO2k4prjk9VI7MSuNf09n6ZC8X6GJ1GrLL6xf2n88/HsKM3I3jLrTsHKCmG7AJumjlvza0k7wmp6l+sbHgZPMDs4qmbFoCJOWGzunAxBnRFSKLduIuMxwlP0LhXjXSBhpTInM4C3egtRhvg98nRMCM9Dy4EHVvUdUWNVbEEuq7ToyYd31Z88zrjuvzpepxGZUeix3scylMZrW4hIFB0PePa1Q4zYfIeYMYsDTkQme98A==; Received: by lekensteyn.nl with esmtpsa (TLS1.2:RSA_AES_128_CBC_SHA256:128) (Exim 4.80) (envelope-from ) id 1Y4ssH-00082D-2S; Sat, 27 Dec 2014 16:01:49 +0100 From: Peter Wu To: qemu-devel@nongnu.org Date: Sat, 27 Dec 2014 16:01:40 +0100 Message-Id: <1419692504-29373-7-git-send-email-peter@lekensteyn.nl> X-Mailer: git-send-email 2.2.1 In-Reply-To: <1419692504-29373-1-git-send-email-peter@lekensteyn.nl> References: <1419692504-29373-1-git-send-email-peter@lekensteyn.nl> X-detected-operating-system: by eggs.gnu.org: Error: Malformed IPv6 address (bad octet value). X-Received-From: 2a02:2308::360:1:25 Cc: Kevin Wolf , Stefan Hajnoczi Subject: [Qemu-devel] [PATCH 06/10] block/dmg: process XML plists X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org The format is simple enough to avoid using a full-blown XML parser. The offsets are based on the description at http://newosxbook.com/DMG.html Signed-off-by: Peter Wu Reviewed-by: John Snow --- block/dmg.c | 69 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 69 insertions(+) diff --git a/block/dmg.c b/block/dmg.c index 19e4fe2..c03ea01 100644 --- a/block/dmg.c +++ b/block/dmg.c @@ -26,6 +26,7 @@ #include "qemu/bswap.h" #include "qemu/module.h" #include +#include enum { /* Limit chunk sizes to prevent unreasonable amounts of memory being used @@ -333,12 +334,66 @@ fail: return ret; } +static int dmg_read_plist_xml(BlockDriverState *bs, DmgHeaderState *ds, + uint64_t info_begin, uint64_t info_length) +{ + BDRVDMGState *s = bs->opaque; + int ret; + uint8_t *buffer = NULL; + char *data_begin, *data_end; + + /* Have at least some length to avoid NULL for g_malloc. Attempt to set a + * safe upper cap on the data length. A test sample had a XML length of + * about 1 MiB. */ + if (info_length == 0 || info_length > 16 * 1024 * 1024) { + ret = -EINVAL; + goto fail; + } + + buffer = g_malloc(info_length + 1); + buffer[info_length] = '\0'; + ret = bdrv_pread(bs->file, info_begin, buffer, info_length); + if (ret != info_length) { + ret = -EINVAL; + goto fail; + } + + /* look for .... The data is 284 (0x11c) bytes after base64 + * decode. The actual data element has 431 (0x1af) bytes which includes tabs + * and line feeds. */ + data_end = (char *)buffer; + while ((data_begin = strstr(data_end, "")) != NULL) { + gsize out_len = 0; + + data_begin += 6; + data_end = strstr(data_begin, ""); + /* malformed XML? */ + if (data_end == NULL) { + ret = -EINVAL; + goto fail; + } + *data_end++ = '\0'; + g_base64_decode_inplace(data_begin, &out_len); + ret = dmg_read_mish_block(s, ds, (uint8_t *)data_begin, + (uint32_t)out_len); + if (ret < 0) { + goto fail; + } + } + ret = 0; + +fail: + g_free(buffer); + return ret; +} + static int dmg_open(BlockDriverState *bs, QDict *options, int flags, Error **errp) { BDRVDMGState *s = bs->opaque; DmgHeaderState ds; uint64_t rsrc_fork_offset, rsrc_fork_length; + uint64_t plist_xml_offset, plist_xml_length; int64_t offset; int ret; @@ -366,12 +421,26 @@ static int dmg_open(BlockDriverState *bs, QDict *options, int flags, if (ret < 0) { goto fail; } + /* offset of property list (XMLOffset) */ + ret = read_uint64(bs, offset + 0xd8, &plist_xml_offset); + if (ret < 0) { + goto fail; + } + ret = read_uint64(bs, offset + 0xe0, &plist_xml_length); + if (ret < 0) { + goto fail; + } if (rsrc_fork_offset != 0 && rsrc_fork_length != 0) { ret = dmg_read_resource_fork(bs, &ds, rsrc_fork_offset, rsrc_fork_length); if (ret < 0) { goto fail; } + } else if (plist_xml_offset != 0 && plist_xml_length != 0) { + ret = dmg_read_plist_xml(bs, &ds, plist_xml_offset, plist_xml_length); + if (ret < 0) { + goto fail; + } } else { ret = -EINVAL; goto fail;