From: PrasannaKumar Muralidharan Subject: Re: [RFC PATCH v1 1/1] crypto: algif_compression - User-space interface for compression Date: Fri, 14 Apr 2017 09:49:34 +0530 Message-ID: References: <1492108494-10694-1-git-send-email-akamaluddin@cavium.com> <1492108494-10694-2-git-send-email-akamaluddin@cavium.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Cc: Herbert Xu , linux-crypto@vger.kernel.org, akamaluddin@cavium.com, pathreya@cavium.com, machalla@cavium.com To: Abed Kamaluddin Return-path: Received: from mail-ua0-f195.google.com ([209.85.217.195]:35357 "EHLO mail-ua0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750734AbdDNETg (ORCPT ); Fri, 14 Apr 2017 00:19:36 -0400 Received: by mail-ua0-f195.google.com with SMTP id g30so5439504uab.2 for ; Thu, 13 Apr 2017 21:19:35 -0700 (PDT) In-Reply-To: <1492108494-10694-2-git-send-email-akamaluddin@cavium.com> Sender: linux-crypto-owner@vger.kernel.org List-ID: On 14 April 2017 at 00:04, Abed Kamaluddin wrote: > crypto: algif_compression - User-space interface for compression > > This patch adds af_alg plugin for compression algorithms of type scomp/acomp > registered to the kernel crypto layer. > > The user needs to set operation (compression/decompression) as a control > message to sendmsg, identical to selecting the cipher operation type in case of > ciphers. Once a sendmsg call occurs, no further writes can be made to the > socket until all previous data has been processed and read. Therefore the > interface only supports one request at a time. > > The interface is completely synchronous; all operations are carried out in > recvmsg and will complete prior to the system call returning. > > The sendmsg and recvmsg interface supports directly reading/writing to > user-space without additional copying, i.e., the kernel crypto interface will > receive the user-space address as its input/output SG list. The scomp interface > or crypto drivers may copy the data as required. > > Signed-off-by: Abed Kamaluddin > Signed-off-by: Mahipal Challa > > --- > crypto/Kconfig | 11 ++ > crypto/Makefile | 1 + > crypto/algif_compression.c | 272 ++++++++++++++++++++++++++++++++++++++++++++ > include/uapi/linux/if_alg.h | 2 + > 4 files changed, 286 insertions(+) > > diff --git a/crypto/Kconfig b/crypto/Kconfig > index f37e9cc..13b03ba 100644 > --- a/crypto/Kconfig > +++ b/crypto/Kconfig > @@ -1741,6 +1741,17 @@ config CRYPTO_USER_API_AEAD > This option enables the user-spaces interface for AEAD > cipher algorithms. > > +config CRYPTO_USER_API_COMPRESSION > + tristate "User-space interface for compression algorithms" > + depends on NET > + select CRYPTO_ACOMP > + select CRYPTO_USER_API > + help > + This option enables the user-space interface for compression > + algorithms. Enable this option for access to compression algorithms > + of type scomp/acomp exported by the kernel crypto layer through > + AF_ALG interface. > + > config CRYPTO_HASH_INFO > bool > > diff --git a/crypto/Makefile b/crypto/Makefile > index 8a44057..1469e06 100644 > --- a/crypto/Makefile > +++ b/crypto/Makefile > @@ -134,6 +134,7 @@ obj-$(CONFIG_CRYPTO_TEST) += tcrypt.o > obj-$(CONFIG_CRYPTO_GHASH) += ghash-generic.o > obj-$(CONFIG_CRYPTO_USER_API) += af_alg.o > obj-$(CONFIG_CRYPTO_USER_API_HASH) += algif_hash.o > +obj-$(CONFIG_CRYPTO_USER_API_COMPRESSION) += algif_compression.o > obj-$(CONFIG_CRYPTO_USER_API_SKCIPHER) += algif_skcipher.o > obj-$(CONFIG_CRYPTO_USER_API_RNG) += algif_rng.o > obj-$(CONFIG_CRYPTO_USER_API_AEAD) += algif_aead.o > diff --git a/crypto/algif_compression.c b/crypto/algif_compression.c > new file mode 100644 > index 0000000..0ba6d1e > --- /dev/null > +++ b/crypto/algif_compression.c > @@ -0,0 +1,272 @@ > +/* > + * algif_compression: User-space interface for COMPRESSION algorithms > + * > + * This file provides user-space API support for compression algorithms > + * registered through the kernel crypto layer. > + * > + * Copyright (C) 2017 Cavium, Inc. > + * > + * Original Authors: Abed Kamaluddin > + * > + * This program is free software; you can redistribute it and/or modify it > + * under the terms of the GNU General Public License as published by the Free > + * Software Foundation; either version 2 of the License, or (at your option) > + * any later version. > + */ > + > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +/* scomp scratch is currently 128KB */ > +#define COMP_BUFFER_SIZE 65535 > + > +struct comp_ctx { > + struct af_alg_sgl tsgl; > + struct af_alg_sgl rsgl; > + struct af_alg_completion completion; > + unsigned int clen; > + unsigned int slen; > + unsigned int dlen; > + bool comp; > + bool used; > + struct acomp_req *acomp_req; > +}; Is it necessary to have 3 len fields viz clen, slen, dlen? Please add a comment indicating their purpose. > +struct comp_tfm { > + struct crypto_acomp *acomp; > +}; > + > +static int comp_sendmsg(struct socket *sock, struct msghdr *msg, > + size_t ignored) > +{ > + struct sock *sk = sock->sk; > + struct alg_sock *ask = alg_sk(sk); > + struct comp_ctx *ctx = ask->private; > + struct af_alg_control con = {}; > + int limit = COMP_BUFFER_SIZE; > + int len; > + int err = -EINVAL; > + > + if (msg->msg_controllen) { > + err = af_alg_cmsg_send(msg, &con); > + if (err) > + return err; > + > + switch (con.op) { > + case ALG_OP_COMPRESS: > + ctx->comp = 1; > + break; > + > + case ALG_OP_DECOMPRESS: > + ctx->comp = 0; > + break; > + > + default: > + return -EINVAL; > + } > + } > + > + lock_sock(sk); > + > + /* One request at a time supported, data submitted for comp/decomp will > + * be processed at subsequent recvmsg > + */ > + if (ctx->used) { > + err = -EAGAIN; > + goto unlock; > + } > + > + len = msg_data_left(msg); > + > + if (len > limit) > + len = limit; > + > + len = af_alg_make_sg(&ctx->tsgl, &msg->msg_iter, len); > + > + if (len < 0) { > + err = len; > + goto unlock; > + } > + > + ctx->slen = len; > + ctx->used = 1; > + > +unlock: > + release_sock(sk); > + > + return err ?: len; > +} > + > +static int comp_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, > + int flags) > +{ > + struct sock *sk = sock->sk; > + struct alg_sock *ask = alg_sk(sk); > + struct comp_ctx *ctx = ask->private; > + int rlen = ctx->dlen; > + int err; > + > + if (len > rlen) > + len = rlen; > + > + lock_sock(sk); > + > + if (!ctx->used) { > + err = -EAGAIN; > + goto unlock; > + } > + > + len = af_alg_make_sg(&ctx->rsgl, &msg->msg_iter, len); > + if (len < 0) { > + err = len; > + goto unlock; > + } > + > + acomp_request_set_params(ctx->acomp_req, ctx->tsgl.sg, ctx->rsgl.sg, > + ctx->slen, len); > + > + /* Synchronous completion of comp/decomp requests */ > + err = af_alg_wait_for_completion( > + ctx->comp ? > + crypto_acomp_compress(ctx->acomp_req) : > + crypto_acomp_decompress(ctx->acomp_req), > + &ctx->completion); > + > + /* Add acomp req wrapper for dlen */ > + len = (ctx->acomp_req)->dlen; > + > + af_alg_free_sg(&ctx->tsgl); > + af_alg_free_sg(&ctx->rsgl); > + > +unlock: > + ctx->used = 0; > + release_sock(sk); > + > + return err ?: len; > +} > + > +static struct proto_ops algif_comp_ops = { > + .family = PF_ALG, > + > + .connect = sock_no_connect, > + .socketpair = sock_no_socketpair, > + .getname = sock_no_getname, > + .ioctl = sock_no_ioctl, > + .listen = sock_no_listen, > + .shutdown = sock_no_shutdown, > + .getsockopt = sock_no_getsockopt, > + .mmap = sock_no_mmap, > + .bind = sock_no_bind, > + .setsockopt = sock_no_setsockopt, > + .poll = sock_no_poll, > + > + .release = af_alg_release, > + .sendmsg = comp_sendmsg, > + .recvmsg = comp_recvmsg, > + .sendpage = sock_no_sendpage, > + .accept = sock_no_accept, > +}; > + > +static void *comp_bind(const char *name, u32 type, u32 mask) > +{ > + struct comp_tfm *tfm; > + struct crypto_acomp *acomp; > + > + tfm = kzalloc(sizeof(*tfm), GFP_KERNEL); > + if (!tfm) > + return ERR_PTR(-ENOMEM); > + > + acomp = crypto_alloc_acomp(name, type, mask); > + if (IS_ERR_OR_NULL(acomp)) { > + kfree(tfm); > + return ERR_PTR(-ENOMEM); > + } > + tfm->acomp = acomp; > + > + return tfm; > +} > + > +static void comp_release(void *private) > +{ > + struct comp_tfm *tfm = private; > + > + crypto_free_acomp(tfm->acomp); > + kfree(tfm); > +} > + > +static void comp_sock_destruct(struct sock *sk) > +{ > + struct alg_sock *ask = alg_sk(sk); > + struct comp_ctx *ctx = ask->private; > + > + acomp_request_free(ctx->acomp_req); > + sock_kfree_s(sk, ctx, ctx->clen); > + af_alg_release_parent(sk); > +} > + > +static int comp_accept_parent(void *private, struct sock *sk) > +{ > + struct comp_ctx *ctx; > + struct alg_sock *ask = alg_sk(sk); > + struct comp_tfm *tfm = private; > + struct crypto_acomp *acomp = tfm->acomp; > + unsigned int len = sizeof(*ctx); > + > + ctx = sock_kmalloc(sk, len, GFP_KERNEL); > + if (!ctx) > + return -ENOMEM; > + > + ctx->used = 0; > + ctx->clen = len; > + ctx->dlen = COMP_BUFFER_SIZE; > + ctx->slen = COMP_BUFFER_SIZE; > + > + af_alg_init_completion(&ctx->completion); > + > + ctx->acomp_req = acomp_request_alloc(acomp); > + if (!ctx->acomp_req) { > + sock_kfree_s(sk, ctx, ctx->clen); > + return -ENOMEM; > + } > + > + acomp_request_set_callback(ctx->acomp_req, CRYPTO_TFM_REQ_MAY_BACKLOG, > + af_alg_complete, &ctx->completion); > + > + ask->private = ctx; > + sk->sk_destruct = comp_sock_destruct; > + > + return 0; > +} > + > +static const struct af_alg_type algif_type_comp = { > + .bind = comp_bind, > + .release = comp_release, > + .accept = comp_accept_parent, > + .ops = &algif_comp_ops, > + .name = "compression", > + .owner = THIS_MODULE > +}; > + > +static int __init algif_comp_init(void) > +{ > + return af_alg_register_type(&algif_type_comp); > +} > + > +static void __exit algif_comp_exit(void) > +{ > + int err = af_alg_unregister_type(&algif_type_comp); > + > + BUG_ON(err); > +} > + > +module_init(algif_comp_init); > +module_exit(algif_comp_exit); > +MODULE_LICENSE("GPL"); > diff --git a/include/uapi/linux/if_alg.h b/include/uapi/linux/if_alg.h > index f2acd2f..5cca9eb 100644 > --- a/include/uapi/linux/if_alg.h > +++ b/include/uapi/linux/if_alg.h > @@ -38,5 +38,7 @@ struct af_alg_iv { > /* Operations */ > #define ALG_OP_DECRYPT 0 > #define ALG_OP_ENCRYPT 1 > +#define ALG_OP_DECOMPRESS 0 > +#define ALG_OP_COMPRESS 1 > > #endif /* _LINUX_IF_ALG_H */ > -- > 2.7.4 > Regards, PrasannaKumar