This implements the worst-case compression size querying interface for
lz4hc, based on the logic originally used by pstore.
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
crypto/lz4hc.c | 22 +++++++++++++++++++++-
1 file changed, 21 insertions(+), 1 deletion(-)
diff --git a/crypto/lz4hc.c b/crypto/lz4hc.c
index 2be14f054daf..cf6f38a1c35b 100644
--- a/crypto/lz4hc.c
+++ b/crypto/lz4hc.c
@@ -118,6 +118,24 @@ static int lz4hc_decompress_crypto(struct crypto_tfm *tfm, const u8 *src,
return __lz4hc_decompress_crypto(src, slen, dst, dlen, NULL);
}
+static int __lz4hc_zbufsize_crypto(unsigned int slen, unsigned int *dlen)
+{
+ *dlen = LZ4_compressBound(slen);
+ return 0;
+}
+
+static int lz4hc_szbufsize(struct crypto_scomp *tfm, unsigned int slen,
+ unsigned int *dlen, void *ctx)
+{
+ return __lz4hc_zbufsize_crypto(slen, dlen);
+}
+
+static int lz4hc_zbufsize_crypto(struct crypto_tfm *tfm, unsigned int slen,
+ unsigned int *dlen)
+{
+ return __lz4hc_zbufsize_crypto(slen, dlen);
+}
+
static struct crypto_alg alg_lz4hc = {
.cra_name = "lz4hc",
.cra_flags = CRYPTO_ALG_TYPE_COMPRESS,
@@ -128,7 +146,8 @@ static struct crypto_alg alg_lz4hc = {
.cra_exit = lz4hc_exit,
.cra_u = { .compress = {
.coa_compress = lz4hc_compress_crypto,
- .coa_decompress = lz4hc_decompress_crypto } }
+ .coa_decompress = lz4hc_decompress_crypto,
+ .coa_zbufsize = lz4hc_zbufsize_crypto } }
};
static struct scomp_alg scomp = {
@@ -136,6 +155,7 @@ static struct scomp_alg scomp = {
.free_ctx = lz4hc_free_ctx,
.compress = lz4hc_scompress,
.decompress = lz4hc_sdecompress,
+ .zbufsize = lz4hc_szbufsize,
.base = {
.cra_name = "lz4hc",
.cra_driver_name = "lz4hc-scomp",
--
2.17.1
