From 6d49d3a859b0f19226dbb0df5e7f50267b42f45c Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Fri, 21 Feb 2020 11:25:19 +0000 Subject: luks: extract qcrypto_block_calculate_payload_offset() The qcow2 .bdrv_measure() code calculates the crypto payload offset. This logic really belongs in crypto/block.c where it can be reused by other image formats. The "luks" block driver will need this same logic in order to implement .bdrv_measure(), so extract the qcrypto_block_calculate_payload_offset() function now. Signed-off-by: Stefan Hajnoczi Reviewed-by: Max Reitz Message-Id: <20200221112522.1497712-2-stefanha@redhat.com> Signed-off-by: Max Reitz --- crypto/block.c | 36 ++++++++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+) (limited to 'crypto') diff --git a/crypto/block.c b/crypto/block.c index 3257528..6f42b32 100644 --- a/crypto/block.c +++ b/crypto/block.c @@ -115,6 +115,42 @@ QCryptoBlock *qcrypto_block_create(QCryptoBlockCreateOptions *options, } +static ssize_t qcrypto_block_headerlen_hdr_init_func(QCryptoBlock *block, + size_t headerlen, void *opaque, Error **errp) +{ + size_t *headerlenp = opaque; + + /* Stash away the payload size */ + *headerlenp = headerlen; + return 0; +} + + +static ssize_t qcrypto_block_headerlen_hdr_write_func(QCryptoBlock *block, + size_t offset, const uint8_t *buf, size_t buflen, + void *opaque, Error **errp) +{ + /* Discard the bytes, we're not actually writing to an image */ + return buflen; +} + + +bool +qcrypto_block_calculate_payload_offset(QCryptoBlockCreateOptions *create_opts, + const char *optprefix, + size_t *len, + Error **errp) +{ + /* Fake LUKS creation in order to determine the payload size */ + g_autoptr(QCryptoBlock) crypto = + qcrypto_block_create(create_opts, optprefix, + qcrypto_block_headerlen_hdr_init_func, + qcrypto_block_headerlen_hdr_write_func, + len, errp); + return crypto != NULL; +} + + QCryptoBlockInfo *qcrypto_block_get_info(QCryptoBlock *block, Error **errp) { -- cgit v1.1