![Stephan Mueller](/assets/img/avatar_default.png)
Consolidate following data structures: skcipher_async_req, aead_async_req -> af_alg_async_req skcipher_rsgl, aead_rsql -> af_alg_rsgl skcipher_tsgl, aead_tsql -> af_alg_tsgl skcipher_ctx, aead_ctx -> af_alg_ctx Consolidate following functions: skcipher_sndbuf, aead_sndbuf -> af_alg_sndbuf skcipher_writable, aead_writable -> af_alg_writable skcipher_rcvbuf, aead_rcvbuf -> af_alg_rcvbuf skcipher_readable, aead_readable -> af_alg_readable aead_alloc_tsgl, skcipher_alloc_tsgl -> af_alg_alloc_tsgl aead_count_tsgl, skcipher_count_tsgl -> af_alg_count_tsgl aead_pull_tsgl, skcipher_pull_tsgl -> af_alg_pull_tsgl aead_free_areq_sgls, skcipher_free_areq_sgls -> af_alg_free_areq_sgls aead_wait_for_wmem, skcipher_wait_for_wmem -> af_alg_wait_for_wmem aead_wmem_wakeup, skcipher_wmem_wakeup -> af_alg_wmem_wakeup aead_wait_for_data, skcipher_wait_for_data -> af_alg_wait_for_data aead_data_wakeup, skcipher_data_wakeup -> af_alg_data_wakeup aead_sendmsg, skcipher_sendmsg -> af_alg_sendmsg aead_sendpage, skcipher_sendpage -> af_alg_sendpage aead_async_cb, skcipher_async_cb -> af_alg_async_cb aead_poll, skcipher_poll -> af_alg_poll Split out the following common code from recvmsg: af_alg_alloc_areq: allocation of the request data structure for the cipher operation af_alg_get_rsgl: creation of the RX SGL anchored in the request data structure The following changes to the implementation without affecting the functionality have been applied to synchronize slightly different code bases in algif_skcipher and algif_aead: The wakeup in af_alg_wait_for_data is triggered when either more data is received or the indicator that more data is to be expected is released. The first is triggered by user space, the second is triggered by the kernel upon finishing the processing of data (i.e. the kernel is ready for more). af_alg_sendmsg uses size_t in min_t calculation for obtaining len. Return code determination is consistent with algif_skcipher. The scope of the variable i is reduced to match algif_aead. The type of the variable i is switched from int to unsigned int to match algif_aead. af_alg_sendpage does not contain the superfluous err = 0 from aead_sendpage. af_alg_async_cb requires to store the number of output bytes in areq->outlen before the AIO callback is triggered. The POLLIN / POLLRDNORM is now set when either not more data is given or the kernel is supplied with data. This is consistent to the wakeup from sleep when the kernel waits for data. The request data structure is extended by the field last_rsgl which points to the last RX SGL list entry. This shall help recvmsg implementation to chain the RX SGL to other SG(L)s if needed. It is currently used by algif_aead which chains the tag SGL to the RX SGL during decryption. Signed-off-by: Stephan Mueller <smueller@chronox.de> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
436 lines
11 KiB
C
436 lines
11 KiB
C
/*
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* algif_skcipher: User-space interface for skcipher algorithms
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*
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* This file provides the user-space API for symmetric key ciphers.
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*
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* Copyright (c) 2010 Herbert Xu <herbert@gondor.apana.org.au>
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the Free
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* Software Foundation; either version 2 of the License, or (at your option)
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* any later version.
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*
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* The following concept of the memory management is used:
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*
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* The kernel maintains two SGLs, the TX SGL and the RX SGL. The TX SGL is
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* filled by user space with the data submitted via sendpage/sendmsg. Filling
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* up the TX SGL does not cause a crypto operation -- the data will only be
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* tracked by the kernel. Upon receipt of one recvmsg call, the caller must
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* provide a buffer which is tracked with the RX SGL.
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*
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* During the processing of the recvmsg operation, the cipher request is
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* allocated and prepared. As part of the recvmsg operation, the processed
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* TX buffers are extracted from the TX SGL into a separate SGL.
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*
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* After the completion of the crypto operation, the RX SGL and the cipher
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* request is released. The extracted TX SGL parts are released together with
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* the RX SGL release.
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*/
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#include <crypto/scatterwalk.h>
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#include <crypto/skcipher.h>
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#include <crypto/if_alg.h>
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#include <linux/init.h>
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#include <linux/list.h>
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#include <linux/kernel.h>
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#include <linux/mm.h>
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#include <linux/module.h>
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#include <linux/net.h>
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#include <net/sock.h>
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struct skcipher_tfm {
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struct crypto_skcipher *skcipher;
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bool has_key;
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};
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static int skcipher_sendmsg(struct socket *sock, struct msghdr *msg,
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size_t size)
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{
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struct sock *sk = sock->sk;
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struct alg_sock *ask = alg_sk(sk);
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struct sock *psk = ask->parent;
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struct alg_sock *pask = alg_sk(psk);
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struct skcipher_tfm *skc = pask->private;
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struct crypto_skcipher *tfm = skc->skcipher;
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unsigned ivsize = crypto_skcipher_ivsize(tfm);
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return af_alg_sendmsg(sock, msg, size, ivsize);
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}
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static int _skcipher_recvmsg(struct socket *sock, struct msghdr *msg,
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size_t ignored, int flags)
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{
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struct sock *sk = sock->sk;
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struct alg_sock *ask = alg_sk(sk);
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struct sock *psk = ask->parent;
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struct alg_sock *pask = alg_sk(psk);
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struct af_alg_ctx *ctx = ask->private;
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struct skcipher_tfm *skc = pask->private;
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struct crypto_skcipher *tfm = skc->skcipher;
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unsigned int bs = crypto_skcipher_blocksize(tfm);
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struct af_alg_async_req *areq;
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int err = 0;
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size_t len = 0;
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/* Allocate cipher request for current operation. */
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areq = af_alg_alloc_areq(sk, sizeof(struct af_alg_async_req) +
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crypto_skcipher_reqsize(tfm));
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if (IS_ERR(areq))
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return PTR_ERR(areq);
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/* convert iovecs of output buffers into RX SGL */
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err = af_alg_get_rsgl(sk, msg, flags, areq, -1, &len);
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if (err)
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goto free;
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/* Process only as much RX buffers for which we have TX data */
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if (len > ctx->used)
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len = ctx->used;
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/*
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* If more buffers are to be expected to be processed, process only
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* full block size buffers.
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*/
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if (ctx->more || len < ctx->used)
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len -= len % bs;
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/*
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* Create a per request TX SGL for this request which tracks the
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* SG entries from the global TX SGL.
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*/
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areq->tsgl_entries = af_alg_count_tsgl(sk, len, 0);
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if (!areq->tsgl_entries)
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areq->tsgl_entries = 1;
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areq->tsgl = sock_kmalloc(sk, sizeof(*areq->tsgl) * areq->tsgl_entries,
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GFP_KERNEL);
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if (!areq->tsgl) {
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err = -ENOMEM;
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goto free;
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}
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sg_init_table(areq->tsgl, areq->tsgl_entries);
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af_alg_pull_tsgl(sk, len, areq->tsgl, 0);
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/* Initialize the crypto operation */
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skcipher_request_set_tfm(&areq->cra_u.skcipher_req, tfm);
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skcipher_request_set_crypt(&areq->cra_u.skcipher_req, areq->tsgl,
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areq->first_rsgl.sgl.sg, len, ctx->iv);
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if (msg->msg_iocb && !is_sync_kiocb(msg->msg_iocb)) {
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/* AIO operation */
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areq->iocb = msg->msg_iocb;
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skcipher_request_set_callback(&areq->cra_u.skcipher_req,
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CRYPTO_TFM_REQ_MAY_SLEEP,
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af_alg_async_cb, areq);
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err = ctx->enc ?
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crypto_skcipher_encrypt(&areq->cra_u.skcipher_req) :
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crypto_skcipher_decrypt(&areq->cra_u.skcipher_req);
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} else {
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/* Synchronous operation */
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skcipher_request_set_callback(&areq->cra_u.skcipher_req,
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CRYPTO_TFM_REQ_MAY_SLEEP |
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CRYPTO_TFM_REQ_MAY_BACKLOG,
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af_alg_complete,
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&ctx->completion);
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err = af_alg_wait_for_completion(ctx->enc ?
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crypto_skcipher_encrypt(&areq->cra_u.skcipher_req) :
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crypto_skcipher_decrypt(&areq->cra_u.skcipher_req),
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&ctx->completion);
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}
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/* AIO operation in progress */
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if (err == -EINPROGRESS) {
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sock_hold(sk);
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/* Remember output size that will be generated. */
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areq->outlen = len;
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return -EIOCBQUEUED;
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}
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free:
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af_alg_free_areq_sgls(areq);
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sock_kfree_s(sk, areq, areq->areqlen);
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return err ? err : len;
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}
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static int skcipher_recvmsg(struct socket *sock, struct msghdr *msg,
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size_t ignored, int flags)
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{
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struct sock *sk = sock->sk;
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int ret = 0;
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lock_sock(sk);
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while (msg_data_left(msg)) {
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int err = _skcipher_recvmsg(sock, msg, ignored, flags);
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/*
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* This error covers -EIOCBQUEUED which implies that we can
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* only handle one AIO request. If the caller wants to have
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* multiple AIO requests in parallel, he must make multiple
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* separate AIO calls.
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*
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* Also return the error if no data has been processed so far.
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*/
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if (err <= 0) {
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if (err == -EIOCBQUEUED || !ret)
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ret = err;
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goto out;
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}
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ret += err;
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}
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out:
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af_alg_wmem_wakeup(sk);
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release_sock(sk);
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return ret;
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}
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static struct proto_ops algif_skcipher_ops = {
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.family = PF_ALG,
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.connect = sock_no_connect,
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.socketpair = sock_no_socketpair,
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.getname = sock_no_getname,
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.ioctl = sock_no_ioctl,
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.listen = sock_no_listen,
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.shutdown = sock_no_shutdown,
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.getsockopt = sock_no_getsockopt,
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.mmap = sock_no_mmap,
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.bind = sock_no_bind,
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.accept = sock_no_accept,
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.setsockopt = sock_no_setsockopt,
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.release = af_alg_release,
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.sendmsg = skcipher_sendmsg,
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.sendpage = af_alg_sendpage,
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.recvmsg = skcipher_recvmsg,
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.poll = af_alg_poll,
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};
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static int skcipher_check_key(struct socket *sock)
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{
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int err = 0;
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struct sock *psk;
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struct alg_sock *pask;
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struct skcipher_tfm *tfm;
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struct sock *sk = sock->sk;
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struct alg_sock *ask = alg_sk(sk);
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lock_sock(sk);
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if (ask->refcnt)
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goto unlock_child;
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psk = ask->parent;
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pask = alg_sk(ask->parent);
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tfm = pask->private;
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err = -ENOKEY;
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lock_sock_nested(psk, SINGLE_DEPTH_NESTING);
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if (!tfm->has_key)
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goto unlock;
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if (!pask->refcnt++)
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sock_hold(psk);
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ask->refcnt = 1;
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sock_put(psk);
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err = 0;
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unlock:
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release_sock(psk);
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unlock_child:
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release_sock(sk);
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return err;
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}
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static int skcipher_sendmsg_nokey(struct socket *sock, struct msghdr *msg,
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size_t size)
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{
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int err;
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err = skcipher_check_key(sock);
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if (err)
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return err;
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return skcipher_sendmsg(sock, msg, size);
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}
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static ssize_t skcipher_sendpage_nokey(struct socket *sock, struct page *page,
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int offset, size_t size, int flags)
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{
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int err;
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err = skcipher_check_key(sock);
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if (err)
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return err;
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return af_alg_sendpage(sock, page, offset, size, flags);
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}
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static int skcipher_recvmsg_nokey(struct socket *sock, struct msghdr *msg,
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size_t ignored, int flags)
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{
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int err;
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err = skcipher_check_key(sock);
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if (err)
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return err;
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return skcipher_recvmsg(sock, msg, ignored, flags);
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}
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static struct proto_ops algif_skcipher_ops_nokey = {
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.family = PF_ALG,
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.connect = sock_no_connect,
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.socketpair = sock_no_socketpair,
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.getname = sock_no_getname,
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.ioctl = sock_no_ioctl,
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.listen = sock_no_listen,
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.shutdown = sock_no_shutdown,
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.getsockopt = sock_no_getsockopt,
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.mmap = sock_no_mmap,
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.bind = sock_no_bind,
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.accept = sock_no_accept,
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.setsockopt = sock_no_setsockopt,
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.release = af_alg_release,
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.sendmsg = skcipher_sendmsg_nokey,
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.sendpage = skcipher_sendpage_nokey,
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.recvmsg = skcipher_recvmsg_nokey,
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.poll = af_alg_poll,
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};
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static void *skcipher_bind(const char *name, u32 type, u32 mask)
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{
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struct skcipher_tfm *tfm;
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struct crypto_skcipher *skcipher;
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tfm = kzalloc(sizeof(*tfm), GFP_KERNEL);
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if (!tfm)
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return ERR_PTR(-ENOMEM);
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skcipher = crypto_alloc_skcipher(name, type, mask);
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if (IS_ERR(skcipher)) {
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kfree(tfm);
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return ERR_CAST(skcipher);
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}
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tfm->skcipher = skcipher;
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return tfm;
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}
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static void skcipher_release(void *private)
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{
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struct skcipher_tfm *tfm = private;
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crypto_free_skcipher(tfm->skcipher);
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kfree(tfm);
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}
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static int skcipher_setkey(void *private, const u8 *key, unsigned int keylen)
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{
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struct skcipher_tfm *tfm = private;
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int err;
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err = crypto_skcipher_setkey(tfm->skcipher, key, keylen);
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tfm->has_key = !err;
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return err;
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}
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static void skcipher_sock_destruct(struct sock *sk)
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{
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struct alg_sock *ask = alg_sk(sk);
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struct af_alg_ctx *ctx = ask->private;
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struct sock *psk = ask->parent;
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struct alg_sock *pask = alg_sk(psk);
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struct skcipher_tfm *skc = pask->private;
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struct crypto_skcipher *tfm = skc->skcipher;
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af_alg_pull_tsgl(sk, ctx->used, NULL, 0);
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sock_kzfree_s(sk, ctx->iv, crypto_skcipher_ivsize(tfm));
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sock_kfree_s(sk, ctx, ctx->len);
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af_alg_release_parent(sk);
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}
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static int skcipher_accept_parent_nokey(void *private, struct sock *sk)
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{
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struct af_alg_ctx *ctx;
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struct alg_sock *ask = alg_sk(sk);
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struct skcipher_tfm *tfm = private;
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struct crypto_skcipher *skcipher = tfm->skcipher;
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unsigned int len = sizeof(*ctx);
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ctx = sock_kmalloc(sk, len, GFP_KERNEL);
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if (!ctx)
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return -ENOMEM;
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ctx->iv = sock_kmalloc(sk, crypto_skcipher_ivsize(skcipher),
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GFP_KERNEL);
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if (!ctx->iv) {
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sock_kfree_s(sk, ctx, len);
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return -ENOMEM;
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}
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memset(ctx->iv, 0, crypto_skcipher_ivsize(skcipher));
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INIT_LIST_HEAD(&ctx->tsgl_list);
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ctx->len = len;
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ctx->used = 0;
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ctx->rcvused = 0;
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ctx->more = 0;
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ctx->merge = 0;
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ctx->enc = 0;
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af_alg_init_completion(&ctx->completion);
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ask->private = ctx;
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sk->sk_destruct = skcipher_sock_destruct;
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return 0;
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}
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static int skcipher_accept_parent(void *private, struct sock *sk)
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{
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struct skcipher_tfm *tfm = private;
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if (!tfm->has_key && crypto_skcipher_has_setkey(tfm->skcipher))
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return -ENOKEY;
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return skcipher_accept_parent_nokey(private, sk);
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}
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static const struct af_alg_type algif_type_skcipher = {
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.bind = skcipher_bind,
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.release = skcipher_release,
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.setkey = skcipher_setkey,
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.accept = skcipher_accept_parent,
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.accept_nokey = skcipher_accept_parent_nokey,
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.ops = &algif_skcipher_ops,
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.ops_nokey = &algif_skcipher_ops_nokey,
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.name = "skcipher",
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.owner = THIS_MODULE
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};
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static int __init algif_skcipher_init(void)
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{
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return af_alg_register_type(&algif_type_skcipher);
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}
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static void __exit algif_skcipher_exit(void)
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{
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int err = af_alg_unregister_type(&algif_type_skcipher);
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BUG_ON(err);
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}
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module_init(algif_skcipher_init);
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module_exit(algif_skcipher_exit);
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MODULE_LICENSE("GPL");
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