Hi Herbert, This patch adds compression support to the AF_ALG interface exported by the kernel crypto API. By extending AF_ALG, all compression algorithms of types scomp and acomp, which the kernel crypto API allows access to, are now also accessible from userspace. The new compression interface has been tested with both kernel software deflate(scomp) and HW accelerated ThunderX deflate(scomp) using the zpipe example application provided by zlib. The user-space side would look similar to hash/cipher implementations. struct sockaddr_alg sa = { .salg_family = AF_ALG, .salg_type = "compression", .salg_name = "deflate" }; The operations supported are ALG_OP_DECOMPRESS and ALG_OP_COMPRESS. This interface is synchronous and handles one request at a time. The data for compression/decompression is read in sendmsg and all operations are carried out and completed in recvmsg. This interface can utilize full deflate functionality provided by kernel. However to achieve complete zlib functionality in user space, the acomp interface needs to be modified and provide api's to pass context and additional data between the kernel user and algorithm as has been pointed on a different thread. Patches have been generated on top of "kernel/git/herbert/crypto-2.6.git" repo. Abed Kamaluddin (1): crypto: algif_compression - User-space interface for compression crypto/Kconfig | 11 ++ crypto/Makefile | 1 + crypto/algif_compression.c | 272 ++++++++++++++++++++++++++++++++++++++++++++ include/uapi/linux/if_alg.h | 2 + 4 files changed, 286 insertions(+) create mode 100644 crypto/algif_compression.c -- 2.7.4