Skip to content

Commit

Permalink
crypto: af_alg - add async support to algif_aead
Browse files Browse the repository at this point in the history 
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: Tadeusz Struk <[email protected]>
Signed-off-by: Herbert Xu <[email protected]>
  • Loading branch information
@tstruk @herbertx
tstruk authored and herbertx committed Apr 5, 2016
1 parent 47cd306 commit 83094e5
Showing 1 changed file with 237 additions and 31 deletions.
268 changes: 237 additions & 31 deletions crypto/algif_aead.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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>
Expand All @@ -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;

Expand Down Expand Up @@ -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);
Expand All @@ -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)
Expand Down Expand Up @@ -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);

Expand Down Expand Up @@ -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;
Expand All @@ -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);

Expand All @@ -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)
{
Expand Down Expand Up @@ -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);
Expand Down Expand Up @@ -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;

Expand Down

0 comments on commit 83094e5

Please sign in to comment.