From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:49870) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YC8xt-0001Sd-9g for qemu-devel@nongnu.org; Fri, 16 Jan 2015 10:37:41 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YC8xr-0000gx-Pg for qemu-devel@nongnu.org; Fri, 16 Jan 2015 10:37:37 -0500 Received: from mx1.redhat.com ([209.132.183.28]:57719) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YC8xr-0000gs-JI for qemu-devel@nongnu.org; Fri, 16 Jan 2015 10:37:35 -0500 From: Stefan Hajnoczi Date: Fri, 16 Jan 2015 15:37:04 +0000 Message-Id: <1421422633-25536-8-git-send-email-stefanha@redhat.com> In-Reply-To: <1421422633-25536-1-git-send-email-stefanha@redhat.com> References: <1421422633-25536-1-git-send-email-stefanha@redhat.com> Subject: [Qemu-devel] [PULL 07/16] block/dmg: process XML plists List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Peter Maydell , Peter Wu , Stefan Hajnoczi From: Peter Wu The format is simple enough to avoid using a full-blown XML parser. It assumes that all BLKX items begin with the "mish" magic word, therefore it is not a problem if other values get matched which are not a BLKX block. The offsets are based on the description at http://newosxbook.com/DMG.html Signed-off-by: Peter Wu Reviewed-by: John Snow Message-id: 1420566495-13284-7-git-send-email-peter@lekensteyn.nl Signed-off-by: Stefan Hajnoczi --- block/dmg.c | 74 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 74 insertions(+) diff --git a/block/dmg.c b/block/dmg.c index 5c2c2c2..d4a7520 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 @@ -343,12 +344,66 @@ 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; @@ -382,12 +437,31 @@ static int dmg_open(BlockDriverState *bs, QDict *options, int flags, ret = -EINVAL; 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 (plist_xml_offset >= offset || + plist_xml_length > offset - plist_xml_offset) { + ret = -EINVAL; + goto fail; + } if (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_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; -- 2.1.0