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Commit 83094e5e authored by Tadeusz Struk's avatar Tadeusz Struk Committed by Herbert Xu
Browse files

crypto: af_alg - add async support to algif_aead 



Following the async change for algif_skcipher
this patch adds similar async read to algif_aead.

changes in v3:
- add call to aead_reset_ctx directly from aead_put_sgl instead of calling
  them separatelly one after the other
- remove wait from aead_sock_destruct function as it is not needed
  when sock_hold is used

changes in v2:
- change internal data structures from fixed size arrays, limited to
  RSGL_MAX_ENTRIES, to linked list model with no artificial limitation.
- use sock_kmalloc instead of kmalloc for memory allocation
- use sock_hold instead of separate atomic ctr to wait for outstanding
  request

Signed-off-by: default avatarTadeusz Struk <tadeusz.struk@intel.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 47cd3060

crypto/algif_aead.c

+237 −31
Original line number Diff line number Diff line
@@ -13,7 +13,7 @@ 
 * any later version.

 */



#include <crypto/aead.h>

#include <crypto/internal/aead.h>

#include <crypto/scatterwalk.h>

#include <crypto/if_alg.h>

#include <linux/init.h>
@@ -29,15 +29,24 @@ struct aead_sg_list { 
	struct scatterlist sg[ALG_MAX_PAGES];

};



struct aead_async_rsgl {

	struct af_alg_sgl sgl;

	struct list_head list;

};



struct aead_async_req {

	struct scatterlist *tsgl;

	struct aead_async_rsgl first_rsgl;

	struct list_head list;

	struct kiocb *iocb;

	unsigned int tsgls;

	char iv[];

};



struct aead_ctx {

	struct aead_sg_list tsgl;

	/*

	 * RSGL_MAX_ENTRIES is an artificial limit where user space at maximum

	 * can cause the kernel to allocate RSGL_MAX_ENTRIES * ALG_MAX_PAGES

	 * pages

	 */

#define RSGL_MAX_ENTRIES ALG_MAX_PAGES

	struct af_alg_sgl rsgl[RSGL_MAX_ENTRIES];

	struct aead_async_rsgl first_rsgl;

	struct list_head list;



	void *iv;
@@ -75,6 +84,17 @@ static inline bool aead_sufficient_data(struct aead_ctx *ctx) 
	return ctx->used >= ctx->aead_assoclen + as;

}



static void aead_reset_ctx(struct aead_ctx *ctx)

{

	struct aead_sg_list *sgl = &ctx->tsgl;



	sg_init_table(sgl->sg, ALG_MAX_PAGES);

	sgl->cur = 0;

	ctx->used = 0;

	ctx->more = 0;

	ctx->merge = 0;

}



static void aead_put_sgl(struct sock *sk)

{

	struct alg_sock *ask = alg_sk(sk);
@@ -90,11 +110,7 @@ static void aead_put_sgl(struct sock *sk) 
		put_page(sg_page(sg + i));

		sg_assign_page(sg + i, NULL);

	}

	sg_init_table(sg, ALG_MAX_PAGES);

	sgl->cur = 0;

	ctx->used = 0;

	ctx->more = 0;

	ctx->merge = 0;

	aead_reset_ctx(ctx);

}



static void aead_wmem_wakeup(struct sock *sk)
@@ -349,23 +365,188 @@ static ssize_t aead_sendpage(struct socket *sock, struct page *page, 
	return err ?: size;

}



static int aead_recvmsg(struct socket *sock, struct msghdr *msg, size_t ignored, int flags)

#define GET_ASYM_REQ(req, tfm) (struct aead_async_req *) \

		((char *)req + sizeof(struct aead_request) + \

		 crypto_aead_reqsize(tfm))



 #define GET_REQ_SIZE(tfm) sizeof(struct aead_async_req) + \

	crypto_aead_reqsize(tfm) + crypto_aead_ivsize(tfm) + \

	sizeof(struct aead_request)



static void aead_async_cb(struct crypto_async_request *_req, int err)

{

	struct sock *sk = _req->data;

	struct alg_sock *ask = alg_sk(sk);

	struct aead_ctx *ctx = ask->private;

	struct crypto_aead *tfm = crypto_aead_reqtfm(&ctx->aead_req);

	struct aead_request *req = aead_request_cast(_req);

	struct aead_async_req *areq = GET_ASYM_REQ(req, tfm);

	struct scatterlist *sg = areq->tsgl;

	struct aead_async_rsgl *rsgl;

	struct kiocb *iocb = areq->iocb;

	unsigned int i, reqlen = GET_REQ_SIZE(tfm);



	list_for_each_entry(rsgl, &areq->list, list) {

		af_alg_free_sg(&rsgl->sgl);

		if (rsgl != &areq->first_rsgl)

			sock_kfree_s(sk, rsgl, sizeof(*rsgl));

	}



	for (i = 0; i < areq->tsgls; i++)

		put_page(sg_page(sg + i));



	sock_kfree_s(sk, areq->tsgl, sizeof(*areq->tsgl) * areq->tsgls);

	sock_kfree_s(sk, req, reqlen);

	__sock_put(sk);

	iocb->ki_complete(iocb, err, err);

}



static int aead_recvmsg_async(struct socket *sock, struct msghdr *msg,

			      int flags)

{

	struct sock *sk = sock->sk;

	struct alg_sock *ask = alg_sk(sk);

	struct aead_ctx *ctx = ask->private;

	struct crypto_aead *tfm = crypto_aead_reqtfm(&ctx->aead_req);

	struct aead_async_req *areq;

	struct aead_request *req = NULL;

	struct aead_sg_list *sgl = &ctx->tsgl;

	struct aead_async_rsgl *last_rsgl = NULL, *rsgl;

	unsigned int as = crypto_aead_authsize(tfm);

	unsigned int i, reqlen = GET_REQ_SIZE(tfm);

	int err = -ENOMEM;

	unsigned long used;

	size_t outlen;

	size_t usedpages = 0;



	lock_sock(sk);

	if (ctx->more) {

		err = aead_wait_for_data(sk, flags);

		if (err)

			goto unlock;

	}



	used = ctx->used;

	outlen = used;



	if (!aead_sufficient_data(ctx))

		goto unlock;



	req = sock_kmalloc(sk, reqlen, GFP_KERNEL);

	if (unlikely(!req))

		goto unlock;



	areq = GET_ASYM_REQ(req, tfm);

	memset(&areq->first_rsgl, '\0', sizeof(areq->first_rsgl));

	INIT_LIST_HEAD(&areq->list);

	areq->iocb = msg->msg_iocb;

	memcpy(areq->iv, ctx->iv, crypto_aead_ivsize(tfm));

	aead_request_set_tfm(req, tfm);

	aead_request_set_ad(req, ctx->aead_assoclen);

	aead_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,

				  aead_async_cb, sk);

	used -= ctx->aead_assoclen + (ctx->enc ? as : 0);



	/* take over all tx sgls from ctx */

	areq->tsgl = sock_kmalloc(sk, sizeof(*areq->tsgl) * sgl->cur,

				  GFP_KERNEL);

	if (unlikely(!areq->tsgl))

		goto free;



	sg_init_table(areq->tsgl, sgl->cur);

	for (i = 0; i < sgl->cur; i++)

		sg_set_page(&areq->tsgl[i], sg_page(&sgl->sg[i]),

			    sgl->sg[i].length, sgl->sg[i].offset);



	areq->tsgls = sgl->cur;



	/* create rx sgls */

	while (iov_iter_count(&msg->msg_iter)) {

		size_t seglen = min_t(size_t, iov_iter_count(&msg->msg_iter),

				      (outlen - usedpages));



		if (list_empty(&areq->list)) {

			rsgl = &areq->first_rsgl;



		} else {

			rsgl = sock_kmalloc(sk, sizeof(*rsgl), GFP_KERNEL);

			if (unlikely(!rsgl)) {

				err = -ENOMEM;

				goto free;

			}

		}

		rsgl->sgl.npages = 0;

		list_add_tail(&rsgl->list, &areq->list);



		/* make one iovec available as scatterlist */

		err = af_alg_make_sg(&rsgl->sgl, &msg->msg_iter, seglen);

		if (err < 0)

			goto free;



		usedpages += err;



		/* chain the new scatterlist with previous one */

		if (last_rsgl)

			af_alg_link_sg(&last_rsgl->sgl, &rsgl->sgl);



		last_rsgl = rsgl;



		/* we do not need more iovecs as we have sufficient memory */

		if (outlen <= usedpages)

			break;



		iov_iter_advance(&msg->msg_iter, err);

	}

	err = -EINVAL;

	/* ensure output buffer is sufficiently large */

	if (usedpages < outlen)

		goto free;



	aead_request_set_crypt(req, areq->tsgl, areq->first_rsgl.sgl.sg, used,

			       areq->iv);

	err = ctx->enc ? crypto_aead_encrypt(req) : crypto_aead_decrypt(req);

	if (err) {

		if (err == -EINPROGRESS) {

			sock_hold(sk);

			err = -EIOCBQUEUED;

			aead_reset_ctx(ctx);

			goto unlock;

		} else if (err == -EBADMSG) {

			aead_put_sgl(sk);

		}

		goto free;

	}

	aead_put_sgl(sk);



free:

	list_for_each_entry(rsgl, &areq->list, list) {

		af_alg_free_sg(&rsgl->sgl);

		if (rsgl != &areq->first_rsgl)

			sock_kfree_s(sk, rsgl, sizeof(*rsgl));

	}

	if (areq->tsgl)

		sock_kfree_s(sk, areq->tsgl, sizeof(*areq->tsgl) * areq->tsgls);

	if (req)

		sock_kfree_s(sk, req, reqlen);

unlock:

	aead_wmem_wakeup(sk);

	release_sock(sk);

	return err ? err : outlen;

}



static int aead_recvmsg_sync(struct socket *sock, struct msghdr *msg, int flags)

{

	struct sock *sk = sock->sk;

	struct alg_sock *ask = alg_sk(sk);

	struct aead_ctx *ctx = ask->private;

	unsigned as = crypto_aead_authsize(crypto_aead_reqtfm(&ctx->aead_req));

	struct aead_sg_list *sgl = &ctx->tsgl;

	unsigned int i = 0;

	struct aead_async_rsgl *last_rsgl = NULL;

	struct aead_async_rsgl *rsgl, *tmp;

	int err = -EINVAL;

	unsigned long used = 0;

	size_t outlen = 0;

	size_t usedpages = 0;

	unsigned int cnt = 0;



	/* Limit number of IOV blocks to be accessed below */

	if (msg->msg_iter.nr_segs > RSGL_MAX_ENTRIES)

		return -ENOMSG;



	lock_sock(sk);
@@ -417,21 +598,33 @@ static int aead_recvmsg(struct socket *sock, struct msghdr *msg, size_t ignored, 
		size_t seglen = min_t(size_t, iov_iter_count(&msg->msg_iter),

				      (outlen - usedpages));



		if (list_empty(&ctx->list)) {

			rsgl = &ctx->first_rsgl;

		} else {

			rsgl = sock_kmalloc(sk, sizeof(*rsgl), GFP_KERNEL);

			if (unlikely(!rsgl)) {

				err = -ENOMEM;

				goto unlock;

			}

		}

		rsgl->sgl.npages = 0;

		list_add_tail(&rsgl->list, &ctx->list);



		/* make one iovec available as scatterlist */

		err = af_alg_make_sg(&ctx->rsgl[cnt], &msg->msg_iter,

				     seglen);

		err = af_alg_make_sg(&rsgl->sgl, &msg->msg_iter, seglen);

		if (err < 0)

			goto unlock;

		usedpages += err;

		/* chain the new scatterlist with previous one */

		if (cnt)

			af_alg_link_sg(&ctx->rsgl[cnt-1], &ctx->rsgl[cnt]);

		if (last_rsgl)

			af_alg_link_sg(&last_rsgl->sgl, &rsgl->sgl);



		last_rsgl = rsgl;



		/* we do not need more iovecs as we have sufficient memory */

		if (outlen <= usedpages)

			break;

		iov_iter_advance(&msg->msg_iter, err);

		cnt++;

	}



	err = -EINVAL;
@@ -440,8 +633,7 @@ static int aead_recvmsg(struct socket *sock, struct msghdr *msg, size_t ignored, 
		goto unlock;



	sg_mark_end(sgl->sg + sgl->cur - 1);



	aead_request_set_crypt(&ctx->aead_req, sgl->sg, ctx->rsgl[0].sg,

	aead_request_set_crypt(&ctx->aead_req, sgl->sg, ctx->first_rsgl.sgl.sg,

			       used, ctx->iv);

	aead_request_set_ad(&ctx->aead_req, ctx->aead_assoclen);
@@ -454,23 +646,35 @@ static int aead_recvmsg(struct socket *sock, struct msghdr *msg, size_t ignored, 
		/* EBADMSG implies a valid cipher operation took place */

		if (err == -EBADMSG)

			aead_put_sgl(sk);



		goto unlock;

	}



	aead_put_sgl(sk);



	err = 0;



unlock:

	for (i = 0; i < cnt; i++)

		af_alg_free_sg(&ctx->rsgl[i]);



	list_for_each_entry_safe(rsgl, tmp, &ctx->list, list) {

		af_alg_free_sg(&rsgl->sgl);

		if (rsgl != &ctx->first_rsgl)

			sock_kfree_s(sk, rsgl, sizeof(*rsgl));

		list_del(&rsgl->list);

	}

	INIT_LIST_HEAD(&ctx->list);

	aead_wmem_wakeup(sk);

	release_sock(sk);



	return err ? err : outlen;

}



static int aead_recvmsg(struct socket *sock, struct msghdr *msg, size_t ignored,

			int flags)

{

	return (msg->msg_iocb && !is_sync_kiocb(msg->msg_iocb)) ?

		aead_recvmsg_async(sock, msg, flags) :

		aead_recvmsg_sync(sock, msg, flags);

}



static unsigned int aead_poll(struct file *file, struct socket *sock,

			      poll_table *wait)

{
@@ -540,6 +744,7 @@ static void aead_sock_destruct(struct sock *sk) 
	unsigned int ivlen = crypto_aead_ivsize(

				crypto_aead_reqtfm(&ctx->aead_req));



	WARN_ON(atomic_read(&sk->sk_refcnt) != 0);

	aead_put_sgl(sk);

	sock_kzfree_s(sk, ctx->iv, ivlen);

	sock_kfree_s(sk, ctx, ctx->len);
@@ -574,6 +779,7 @@ static int aead_accept_parent(void *private, struct sock *sk) 
	ctx->aead_assoclen = 0;

	af_alg_init_completion(&ctx->completion);

	sg_init_table(ctx->tsgl.sg, ALG_MAX_PAGES);

	INIT_LIST_HEAD(&ctx->list);



	ask->private = ctx;