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freebsd-skq/sys/opencrypto/ktls_ocf.c
John Baldwin 9c0e3d3a53 Add support for optional separate output buffers to in-kernel crypto. 
Some crypto consumers such as GELI and KTLS for file-backed sendfile
need to store their output in a separate buffer from the input.
Currently these consumers copy the contents of the input buffer into
the output buffer and queue an in-place crypto operation on the output
buffer.  Using a separate output buffer avoids this copy.

- Create a new 'struct crypto_buffer' describing a crypto buffer
  containing a type and type-specific fields.  crp_ilen is gone,
  instead buffers that use a flat kernel buffer have a cb_buf_len
  field for their length.  The length of other buffer types is
  inferred from the backing store (e.g. uio_resid for a uio).
  Requests now have two such structures: crp_buf for the input buffer,
  and crp_obuf for the output buffer.

- Consumers now use helper functions (crypto_use_*,
  e.g. crypto_use_mbuf()) to configure the input buffer.  If an output
  buffer is not configured, the request still modifies the input
  buffer in-place.  A consumer uses a second set of helper functions
  (crypto_use_output_*) to configure an output buffer.

- Consumers must request support for separate output buffers when
  creating a crypto session via the CSP_F_SEPARATE_OUTPUT flag and are
  only permitted to queue a request with a separate output buffer on
  sessions with this flag set.  Existing drivers already reject
  sessions with unknown flags, so this permits drivers to be modified
  to support this extension without requiring all drivers to change.

- Several data-related functions now have matching versions that
  operate on an explicit buffer (e.g. crypto_apply_buf,
  crypto_contiguous_subsegment_buf, bus_dma_load_crp_buf).

- Most of the existing data-related functions operate on the input
  buffer.  However crypto_copyback always writes to the output buffer
  if a request uses a separate output buffer.

- For the regions in input/output buffers, the following conventions
  are followed:
  - AAD and IV are always present in input only and their
    fields are offsets into the input buffer.
  - payload is always present in both buffers.  If a request uses a
    separate output buffer, it must set a new crp_payload_start_output
    field to the offset of the payload in the output buffer.
  - digest is in the input buffer for verify operations, and in the
    output buffer for compute operations.  crp_digest_start is relative
    to the appropriate buffer.

- Add a crypto buffer cursor abstraction.  This is a more general form
  of some bits in the cryptosoft driver that tried to always use uio's.
  However, compared to the original code, this avoids rewalking the uio
  iovec array for requests with multiple vectors.  It also avoids
  allocate an iovec array for mbufs and populating it by instead walking
  the mbuf chain directly.

- Update the cryptosoft(4) driver to support separate output buffers
  making use of the cursor abstraction.

Sponsored by:	Netflix
Differential Revision:	https://reviews.freebsd.org/D24545
2020-05-25 22:12:04 +00:00

401 lines
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/*-
* SPDX-License-Identifier: BSD-2-Clause
*
* Copyright (c) 2019 Netflix Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/counter.h>
#include <sys/endian.h>
#include <sys/kernel.h>
#include <sys/ktls.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/mutex.h>
#include <sys/sysctl.h>
#include <sys/uio.h>
#include <opencrypto/cryptodev.h>
struct ocf_session {
crypto_session_t sid;
struct mtx lock;
};
struct ocf_operation {
struct ocf_session *os;
bool done;
struct iovec iov[0];
};
static MALLOC_DEFINE(M_KTLS_OCF, "ktls_ocf", "OCF KTLS");
SYSCTL_DECL(_kern_ipc_tls);
SYSCTL_DECL(_kern_ipc_tls_stats);
static SYSCTL_NODE(_kern_ipc_tls_stats, OID_AUTO, ocf,
CTLFLAG_RD | CTLFLAG_MPSAFE, 0,
"Kernel TLS offload via OCF stats");
static counter_u64_t ocf_tls12_gcm_crypts;
SYSCTL_COUNTER_U64(_kern_ipc_tls_stats_ocf, OID_AUTO, tls12_gcm_crypts,
CTLFLAG_RD, &ocf_tls12_gcm_crypts,
"Total number of OCF TLS 1.2 GCM encryption operations");
static counter_u64_t ocf_tls13_gcm_crypts;
SYSCTL_COUNTER_U64(_kern_ipc_tls_stats_ocf, OID_AUTO, tls13_gcm_crypts,
CTLFLAG_RD, &ocf_tls13_gcm_crypts,
"Total number of OCF TLS 1.3 GCM encryption operations");
static counter_u64_t ocf_retries;
SYSCTL_COUNTER_U64(_kern_ipc_tls_stats_ocf, OID_AUTO, retries, CTLFLAG_RD,
&ocf_retries,
"Number of OCF encryption operation retries");
static int
ktls_ocf_callback(struct cryptop *crp)
{
struct ocf_operation *oo;
oo = crp->crp_opaque;
mtx_lock(&oo->os->lock);
oo->done = true;
mtx_unlock(&oo->os->lock);
wakeup(oo);
return (0);
}
static int
ktls_ocf_tls12_gcm_encrypt(struct ktls_session *tls,
const struct tls_record_layer *hdr, uint8_t *trailer, struct iovec *iniov,
struct iovec *outiov, int iovcnt, uint64_t seqno,
uint8_t record_type __unused)
{
struct uio uio;
struct tls_aead_data ad;
struct cryptop *crp;
struct ocf_session *os;
struct ocf_operation *oo;
struct iovec *iov;
int i, error;
uint16_t tls_comp_len;
os = tls->cipher;
oo = malloc(sizeof(*oo) + (iovcnt + 2) * sizeof(*iov), M_KTLS_OCF,
M_WAITOK | M_ZERO);
oo->os = os;
iov = oo->iov;
crp = crypto_getreq(os->sid, M_WAITOK);
/* Setup the IV. */
memcpy(crp->crp_iv, tls->params.iv, TLS_AEAD_GCM_LEN);
memcpy(crp->crp_iv + TLS_AEAD_GCM_LEN, hdr + 1, sizeof(uint64_t));
/* Setup the AAD. */
tls_comp_len = ntohs(hdr->tls_length) -
(AES_GMAC_HASH_LEN + sizeof(uint64_t));
ad.seq = htobe64(seqno);
ad.type = hdr->tls_type;
ad.tls_vmajor = hdr->tls_vmajor;
ad.tls_vminor = hdr->tls_vminor;
ad.tls_length = htons(tls_comp_len);
iov[0].iov_base = &ad;
iov[0].iov_len = sizeof(ad);
uio.uio_resid = sizeof(ad);
/*
* OCF always does encryption in place, so copy the data if
* needed. Ugh.
*/
for (i = 0; i < iovcnt; i++) {
iov[i + 1] = outiov[i];
if (iniov[i].iov_base != outiov[i].iov_base)
memcpy(outiov[i].iov_base, iniov[i].iov_base,
outiov[i].iov_len);
uio.uio_resid += outiov[i].iov_len;
}
iov[iovcnt + 1].iov_base = trailer;
iov[iovcnt + 1].iov_len = AES_GMAC_HASH_LEN;
uio.uio_resid += AES_GMAC_HASH_LEN;
uio.uio_iov = iov;
uio.uio_iovcnt = iovcnt + 2;
uio.uio_offset = 0;
uio.uio_segflg = UIO_SYSSPACE;
uio.uio_td = curthread;
crp->crp_op = CRYPTO_OP_ENCRYPT | CRYPTO_OP_COMPUTE_DIGEST;
crp->crp_flags = CRYPTO_F_CBIMM | CRYPTO_F_IV_SEPARATE;
crypto_use_uio(crp, &uio);
crp->crp_opaque = oo;
crp->crp_callback = ktls_ocf_callback;
crp->crp_aad_start = 0;
crp->crp_aad_length = sizeof(ad);
crp->crp_payload_start = sizeof(ad);
crp->crp_payload_length = uio.uio_resid -
(sizeof(ad) + AES_GMAC_HASH_LEN);
crp->crp_digest_start = uio.uio_resid - AES_GMAC_HASH_LEN;
counter_u64_add(ocf_tls12_gcm_crypts, 1);
for (;;) {
error = crypto_dispatch(crp);
if (error)
break;
mtx_lock(&os->lock);
while (!oo->done)
mtx_sleep(oo, &os->lock, 0, "ocfktls", 0);
mtx_unlock(&os->lock);
if (crp->crp_etype != EAGAIN) {
error = crp->crp_etype;
break;
}
crp->crp_etype = 0;
crp->crp_flags &= ~CRYPTO_F_DONE;
oo->done = false;
counter_u64_add(ocf_retries, 1);
}
crypto_freereq(crp);
free(oo, M_KTLS_OCF);
return (error);
}
static int
ktls_ocf_tls13_gcm_encrypt(struct ktls_session *tls,
const struct tls_record_layer *hdr, uint8_t *trailer, struct iovec *iniov,
struct iovec *outiov, int iovcnt, uint64_t seqno, uint8_t record_type)
{
struct uio uio;
struct tls_aead_data_13 ad;
char nonce[12];
struct cryptop *crp;
struct ocf_session *os;
struct ocf_operation *oo;
struct iovec *iov;
int i, error;
os = tls->cipher;
oo = malloc(sizeof(*oo) + (iovcnt + 2) * sizeof(*iov), M_KTLS_OCF,
M_WAITOK | M_ZERO);
oo->os = os;
iov = oo->iov;
crp = crypto_getreq(os->sid, M_WAITOK);
/* Setup the nonce. */
memcpy(nonce, tls->params.iv, tls->params.iv_len);
*(uint64_t *)(nonce + 4) ^= htobe64(seqno);
/* Setup the AAD. */
ad.type = hdr->tls_type;
ad.tls_vmajor = hdr->tls_vmajor;
ad.tls_vminor = hdr->tls_vminor;
ad.tls_length = hdr->tls_length;
iov[0].iov_base = &ad;
iov[0].iov_len = sizeof(ad);
uio.uio_resid = sizeof(ad);
/*
* OCF always does encryption in place, so copy the data if
* needed. Ugh.
*/
for (i = 0; i < iovcnt; i++) {
iov[i + 1] = outiov[i];
if (iniov[i].iov_base != outiov[i].iov_base)
memcpy(outiov[i].iov_base, iniov[i].iov_base,
outiov[i].iov_len);
uio.uio_resid += outiov[i].iov_len;
}
trailer[0] = record_type;
iov[iovcnt + 1].iov_base = trailer;
iov[iovcnt + 1].iov_len = AES_GMAC_HASH_LEN + 1;
uio.uio_resid += AES_GMAC_HASH_LEN + 1;
uio.uio_iov = iov;
uio.uio_iovcnt = iovcnt + 2;
uio.uio_offset = 0;
uio.uio_segflg = UIO_SYSSPACE;
uio.uio_td = curthread;
crp->crp_op = CRYPTO_OP_ENCRYPT | CRYPTO_OP_COMPUTE_DIGEST;
crp->crp_flags = CRYPTO_F_CBIMM | CRYPTO_F_IV_SEPARATE;
crypto_use_uio(crp, &uio);
crp->crp_opaque = oo;
crp->crp_callback = ktls_ocf_callback;
crp->crp_aad_start = 0;
crp->crp_aad_length = sizeof(ad);
crp->crp_payload_start = sizeof(ad);
crp->crp_payload_length = uio.uio_resid -
(sizeof(ad) + AES_GMAC_HASH_LEN);
crp->crp_digest_start = uio.uio_resid - AES_GMAC_HASH_LEN;
memcpy(crp->crp_iv, nonce, sizeof(nonce));
counter_u64_add(ocf_tls13_gcm_crypts, 1);
for (;;) {
error = crypto_dispatch(crp);
if (error)
break;
mtx_lock(&os->lock);
while (!oo->done)
mtx_sleep(oo, &os->lock, 0, "ocfktls", 0);
mtx_unlock(&os->lock);
if (crp->crp_etype != EAGAIN) {
error = crp->crp_etype;
break;
}
crp->crp_etype = 0;
crp->crp_flags &= ~CRYPTO_F_DONE;
oo->done = false;
counter_u64_add(ocf_retries, 1);
}
crypto_freereq(crp);
free(oo, M_KTLS_OCF);
return (error);
}
static void
ktls_ocf_free(struct ktls_session *tls)
{
struct ocf_session *os;
os = tls->cipher;
crypto_freesession(os->sid);
mtx_destroy(&os->lock);
explicit_bzero(os, sizeof(*os));
free(os, M_KTLS_OCF);
}
static int
ktls_ocf_try(struct socket *so, struct ktls_session *tls)
{
struct crypto_session_params csp;
struct ocf_session *os;
int error;
memset(&csp, 0, sizeof(csp));
switch (tls->params.cipher_algorithm) {
case CRYPTO_AES_NIST_GCM_16:
switch (tls->params.cipher_key_len) {
case 128 / 8:
case 256 / 8:
break;
default:
return (EINVAL);
}
csp.csp_mode = CSP_MODE_AEAD;
csp.csp_cipher_alg = CRYPTO_AES_NIST_GCM_16;
csp.csp_cipher_key = tls->params.cipher_key;
csp.csp_cipher_klen = tls->params.cipher_key_len;
csp.csp_ivlen = AES_GCM_IV_LEN;
break;
default:
return (EPROTONOSUPPORT);
}
/* Only TLS 1.2 and 1.3 are supported. */
if (tls->params.tls_vmajor != TLS_MAJOR_VER_ONE ||
tls->params.tls_vminor < TLS_MINOR_VER_TWO ||
tls->params.tls_vminor > TLS_MINOR_VER_THREE)
return (EPROTONOSUPPORT);
os = malloc(sizeof(*os), M_KTLS_OCF, M_NOWAIT | M_ZERO);
if (os == NULL)
return (ENOMEM);
error = crypto_newsession(&os->sid, &csp,
CRYPTO_FLAG_HARDWARE | CRYPTO_FLAG_SOFTWARE);
if (error) {
free(os, M_KTLS_OCF);
return (error);
}
mtx_init(&os->lock, "ktls_ocf", NULL, MTX_DEF);
tls->cipher = os;
if (tls->params.tls_vminor == TLS_MINOR_VER_THREE)
tls->sw_encrypt = ktls_ocf_tls13_gcm_encrypt;
else
tls->sw_encrypt = ktls_ocf_tls12_gcm_encrypt;
tls->free = ktls_ocf_free;
return (0);
}
struct ktls_crypto_backend ocf_backend = {
.name = "OCF",
.prio = 5,
.api_version = KTLS_API_VERSION,
.try = ktls_ocf_try,
};
static int
ktls_ocf_modevent(module_t mod, int what, void *arg)
{
int error;
switch (what) {
case MOD_LOAD:
ocf_tls12_gcm_crypts = counter_u64_alloc(M_WAITOK);
ocf_tls13_gcm_crypts = counter_u64_alloc(M_WAITOK);
ocf_retries = counter_u64_alloc(M_WAITOK);
return (ktls_crypto_backend_register(&ocf_backend));
case MOD_UNLOAD:
error = ktls_crypto_backend_deregister(&ocf_backend);
if (error)
return (error);
counter_u64_free(ocf_tls12_gcm_crypts);
counter_u64_free(ocf_tls13_gcm_crypts);
counter_u64_free(ocf_retries);
return (0);
default:
return (EOPNOTSUPP);
}
}
static moduledata_t ktls_ocf_moduledata = {
"ktls_ocf",
ktls_ocf_modevent,
NULL
};
DECLARE_MODULE(ktls_ocf, ktls_ocf_moduledata, SI_SUB_PROTO_END, SI_ORDER_ANY);
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