linux/net/tls/tls_sw.c

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/*
* Copyright (c) 2016-2017, Mellanox Technologies. All rights reserved.
* Copyright (c) 2016-2017, Dave Watson <davejwatson@fb.com>. All rights reserved.
* Copyright (c) 2016-2017, Lance Chao <lancerchao@fb.com>. All rights reserved.
* Copyright (c) 2016, Fridolin Pokorny <fridolin.pokorny@gmail.com>. All rights reserved.
* Copyright (c) 2016, Nikos Mavrogiannopoulos <nmav@gnutls.org>. All rights reserved.
*
* This software is available to you under a choice of one of two
* licenses. You may choose to be licensed under the terms of the GNU
* General Public License (GPL) Version 2, available from the file
* COPYING in the main directory of this source tree, or the
* OpenIB.org BSD license below:
*
* Redistribution and use in source and binary forms, with or
* without modification, are permitted provided that the following
* conditions are met:
*
* - Redistributions of source code must retain the above
* copyright notice, this list of conditions and the following
* disclaimer.
*
* - 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.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#include <linux/module.h>
#include <crypto/aead.h>
#include <net/tls.h>
static void trim_sg(struct sock *sk, struct scatterlist *sg,
int *sg_num_elem, unsigned int *sg_size, int target_size)
{
int i = *sg_num_elem - 1;
int trim = *sg_size - target_size;
if (trim <= 0) {
WARN_ON(trim < 0);
return;
}
*sg_size = target_size;
while (trim >= sg[i].length) {
trim -= sg[i].length;
sk_mem_uncharge(sk, sg[i].length);
put_page(sg_page(&sg[i]));
i--;
if (i < 0)
goto out;
}
sg[i].length -= trim;
sk_mem_uncharge(sk, trim);
out:
*sg_num_elem = i + 1;
}
static void trim_both_sgl(struct sock *sk, int target_size)
{
struct tls_context *tls_ctx = tls_get_ctx(sk);
struct tls_sw_context *ctx = tls_sw_ctx(tls_ctx);
trim_sg(sk, ctx->sg_plaintext_data,
&ctx->sg_plaintext_num_elem,
&ctx->sg_plaintext_size,
target_size);
if (target_size > 0)
target_size += tls_ctx->overhead_size;
trim_sg(sk, ctx->sg_encrypted_data,
&ctx->sg_encrypted_num_elem,
&ctx->sg_encrypted_size,
target_size);
}
static int alloc_sg(struct sock *sk, int len, struct scatterlist *sg,
int *sg_num_elem, unsigned int *sg_size,
int first_coalesce)
{
struct page_frag *pfrag;
unsigned int size = *sg_size;
int num_elem = *sg_num_elem, use = 0, rc = 0;
struct scatterlist *sge;
unsigned int orig_offset;
len -= size;
pfrag = sk_page_frag(sk);
while (len > 0) {
if (!sk_page_frag_refill(sk, pfrag)) {
rc = -ENOMEM;
goto out;
}
use = min_t(int, len, pfrag->size - pfrag->offset);
if (!sk_wmem_schedule(sk, use)) {
rc = -ENOMEM;
goto out;
}
sk_mem_charge(sk, use);
size += use;
orig_offset = pfrag->offset;
pfrag->offset += use;
sge = sg + num_elem - 1;
if (num_elem > first_coalesce && sg_page(sg) == pfrag->page &&
sg->offset + sg->length == orig_offset) {
sg->length += use;
} else {
sge++;
sg_unmark_end(sge);
sg_set_page(sge, pfrag->page, use, orig_offset);
get_page(pfrag->page);
++num_elem;
if (num_elem == MAX_SKB_FRAGS) {
rc = -ENOSPC;
break;
}
}
len -= use;
}
goto out;
out:
*sg_size = size;
*sg_num_elem = num_elem;
return rc;
}
static int alloc_encrypted_sg(struct sock *sk, int len)
{
struct tls_context *tls_ctx = tls_get_ctx(sk);
struct tls_sw_context *ctx = tls_sw_ctx(tls_ctx);
int rc = 0;
rc = alloc_sg(sk, len, ctx->sg_encrypted_data,
&ctx->sg_encrypted_num_elem, &ctx->sg_encrypted_size, 0);
return rc;
}
static int alloc_plaintext_sg(struct sock *sk, int len)
{
struct tls_context *tls_ctx = tls_get_ctx(sk);
struct tls_sw_context *ctx = tls_sw_ctx(tls_ctx);
int rc = 0;
rc = alloc_sg(sk, len, ctx->sg_plaintext_data,
&ctx->sg_plaintext_num_elem, &ctx->sg_plaintext_size,
tls_ctx->pending_open_record_frags);
return rc;
}
static void free_sg(struct sock *sk, struct scatterlist *sg,
int *sg_num_elem, unsigned int *sg_size)
{
int i, n = *sg_num_elem;
for (i = 0; i < n; ++i) {
sk_mem_uncharge(sk, sg[i].length);
put_page(sg_page(&sg[i]));
}
*sg_num_elem = 0;
*sg_size = 0;
}
static void tls_free_both_sg(struct sock *sk)
{
struct tls_context *tls_ctx = tls_get_ctx(sk);
struct tls_sw_context *ctx = tls_sw_ctx(tls_ctx);
free_sg(sk, ctx->sg_encrypted_data, &ctx->sg_encrypted_num_elem,
&ctx->sg_encrypted_size);
free_sg(sk, ctx->sg_plaintext_data, &ctx->sg_plaintext_num_elem,
&ctx->sg_plaintext_size);
}
static int tls_do_encryption(struct tls_context *tls_ctx,
struct tls_sw_context *ctx, size_t data_len,
gfp_t flags)
{
unsigned int req_size = sizeof(struct aead_request) +
crypto_aead_reqsize(ctx->aead_send);
struct aead_request *aead_req;
int rc;
aead_req = kzalloc(req_size, flags);
if (!aead_req)
return -ENOMEM;
ctx->sg_encrypted_data[0].offset += tls_ctx->prepend_size;
ctx->sg_encrypted_data[0].length -= tls_ctx->prepend_size;
aead_request_set_tfm(aead_req, ctx->aead_send);
aead_request_set_ad(aead_req, TLS_AAD_SPACE_SIZE);
aead_request_set_crypt(aead_req, ctx->sg_aead_in, ctx->sg_aead_out,
data_len, tls_ctx->iv);
aead_request_set_callback(aead_req, CRYPTO_TFM_REQ_MAY_BACKLOG,
crypto_req_done, &ctx->async_wait);
rc = crypto_wait_req(crypto_aead_encrypt(aead_req), &ctx->async_wait);
ctx->sg_encrypted_data[0].offset -= tls_ctx->prepend_size;
ctx->sg_encrypted_data[0].length += tls_ctx->prepend_size;
kfree(aead_req);
return rc;
}
static int tls_push_record(struct sock *sk, int flags,
unsigned char record_type)
{
struct tls_context *tls_ctx = tls_get_ctx(sk);
struct tls_sw_context *ctx = tls_sw_ctx(tls_ctx);
int rc;
sg_mark_end(ctx->sg_plaintext_data + ctx->sg_plaintext_num_elem - 1);
sg_mark_end(ctx->sg_encrypted_data + ctx->sg_encrypted_num_elem - 1);
tls_make_aad(ctx->aad_space, ctx->sg_plaintext_size,
tls_ctx->rec_seq, tls_ctx->rec_seq_size,
record_type);
tls_fill_prepend(tls_ctx,
page_address(sg_page(&ctx->sg_encrypted_data[0])) +
ctx->sg_encrypted_data[0].offset,
ctx->sg_plaintext_size, record_type);
tls_ctx->pending_open_record_frags = 0;
set_bit(TLS_PENDING_CLOSED_RECORD, &tls_ctx->flags);
rc = tls_do_encryption(tls_ctx, ctx, ctx->sg_plaintext_size,
sk->sk_allocation);
if (rc < 0) {
/* If we are called from write_space and
* we fail, we need to set this SOCK_NOSPACE
* to trigger another write_space in the future.
*/
set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
return rc;
}
free_sg(sk, ctx->sg_plaintext_data, &ctx->sg_plaintext_num_elem,
&ctx->sg_plaintext_size);
ctx->sg_encrypted_num_elem = 0;
ctx->sg_encrypted_size = 0;
/* Only pass through MSG_DONTWAIT and MSG_NOSIGNAL flags */
rc = tls_push_sg(sk, tls_ctx, ctx->sg_encrypted_data, 0, flags);
if (rc < 0 && rc != -EAGAIN)
tls_err_abort(sk);
tls_advance_record_sn(sk, tls_ctx);
return rc;
}
static int tls_sw_push_pending_record(struct sock *sk, int flags)
{
return tls_push_record(sk, flags, TLS_RECORD_TYPE_DATA);
}
static int zerocopy_from_iter(struct sock *sk, struct iov_iter *from,
int length)
{
struct tls_context *tls_ctx = tls_get_ctx(sk);
struct tls_sw_context *ctx = tls_sw_ctx(tls_ctx);
struct page *pages[MAX_SKB_FRAGS];
size_t offset;
ssize_t copied, use;
int i = 0;
unsigned int size = ctx->sg_plaintext_size;
int num_elem = ctx->sg_plaintext_num_elem;
int rc = 0;
int maxpages;
while (length > 0) {
i = 0;
maxpages = ARRAY_SIZE(ctx->sg_plaintext_data) - num_elem;
if (maxpages == 0) {
rc = -EFAULT;
goto out;
}
copied = iov_iter_get_pages(from, pages,
length,
maxpages, &offset);
if (copied <= 0) {
rc = -EFAULT;
goto out;
}
iov_iter_advance(from, copied);
length -= copied;
size += copied;
while (copied) {
use = min_t(int, copied, PAGE_SIZE - offset);
sg_set_page(&ctx->sg_plaintext_data[num_elem],
pages[i], use, offset);
sg_unmark_end(&ctx->sg_plaintext_data[num_elem]);
sk_mem_charge(sk, use);
offset = 0;
copied -= use;
++i;
++num_elem;
}
}
out:
ctx->sg_plaintext_size = size;
ctx->sg_plaintext_num_elem = num_elem;
return rc;
}
static int memcopy_from_iter(struct sock *sk, struct iov_iter *from,
int bytes)
{
struct tls_context *tls_ctx = tls_get_ctx(sk);
struct tls_sw_context *ctx = tls_sw_ctx(tls_ctx);
struct scatterlist *sg = ctx->sg_plaintext_data;
int copy, i, rc = 0;
for (i = tls_ctx->pending_open_record_frags;
i < ctx->sg_plaintext_num_elem; ++i) {
copy = sg[i].length;
if (copy_from_iter(
page_address(sg_page(&sg[i])) + sg[i].offset,
copy, from) != copy) {
rc = -EFAULT;
goto out;
}
bytes -= copy;
++tls_ctx->pending_open_record_frags;
if (!bytes)
break;
}
out:
return rc;
}
int tls_sw_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
{
struct tls_context *tls_ctx = tls_get_ctx(sk);
struct tls_sw_context *ctx = tls_sw_ctx(tls_ctx);
int ret = 0;
int required_size;
long timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
bool eor = !(msg->msg_flags & MSG_MORE);
size_t try_to_copy, copied = 0;
unsigned char record_type = TLS_RECORD_TYPE_DATA;
int record_room;
bool full_record;
int orig_size;
if (msg->msg_flags & ~(MSG_MORE | MSG_DONTWAIT | MSG_NOSIGNAL))
return -ENOTSUPP;
lock_sock(sk);
if (tls_complete_pending_work(sk, tls_ctx, msg->msg_flags, &timeo))
goto send_end;
if (unlikely(msg->msg_controllen)) {
ret = tls_proccess_cmsg(sk, msg, &record_type);
if (ret)
goto send_end;
}
while (msg_data_left(msg)) {
if (sk->sk_err) {
ret = -sk->sk_err;
goto send_end;
}
orig_size = ctx->sg_plaintext_size;
full_record = false;
try_to_copy = msg_data_left(msg);
record_room = TLS_MAX_PAYLOAD_SIZE - ctx->sg_plaintext_size;
if (try_to_copy >= record_room) {
try_to_copy = record_room;
full_record = true;
}
required_size = ctx->sg_plaintext_size + try_to_copy +
tls_ctx->overhead_size;
if (!sk_stream_memory_free(sk))
goto wait_for_sndbuf;
alloc_encrypted:
ret = alloc_encrypted_sg(sk, required_size);
if (ret) {
if (ret != -ENOSPC)
goto wait_for_memory;
/* Adjust try_to_copy according to the amount that was
* actually allocated. The difference is due
* to max sg elements limit
*/
try_to_copy -= required_size - ctx->sg_encrypted_size;
full_record = true;
}
if (full_record || eor) {
ret = zerocopy_from_iter(sk, &msg->msg_iter,
try_to_copy);
if (ret)
goto fallback_to_reg_send;
copied += try_to_copy;
ret = tls_push_record(sk, msg->msg_flags, record_type);
if (!ret)
continue;
if (ret == -EAGAIN)
goto send_end;
copied -= try_to_copy;
fallback_to_reg_send:
iov_iter_revert(&msg->msg_iter,
ctx->sg_plaintext_size - orig_size);
trim_sg(sk, ctx->sg_plaintext_data,
&ctx->sg_plaintext_num_elem,
&ctx->sg_plaintext_size,
orig_size);
}
required_size = ctx->sg_plaintext_size + try_to_copy;
alloc_plaintext:
ret = alloc_plaintext_sg(sk, required_size);
if (ret) {
if (ret != -ENOSPC)
goto wait_for_memory;
/* Adjust try_to_copy according to the amount that was
* actually allocated. The difference is due
* to max sg elements limit
*/
try_to_copy -= required_size - ctx->sg_plaintext_size;
full_record = true;
trim_sg(sk, ctx->sg_encrypted_data,
&ctx->sg_encrypted_num_elem,
&ctx->sg_encrypted_size,
ctx->sg_plaintext_size +
tls_ctx->overhead_size);
}
ret = memcopy_from_iter(sk, &msg->msg_iter, try_to_copy);
if (ret)
goto trim_sgl;
copied += try_to_copy;
if (full_record || eor) {
push_record:
ret = tls_push_record(sk, msg->msg_flags, record_type);
if (ret) {
if (ret == -ENOMEM)
goto wait_for_memory;
goto send_end;
}
}
continue;
wait_for_sndbuf:
set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
wait_for_memory:
ret = sk_stream_wait_memory(sk, &timeo);
if (ret) {
trim_sgl:
trim_both_sgl(sk, orig_size);
goto send_end;
}
if (tls_is_pending_closed_record(tls_ctx))
goto push_record;
if (ctx->sg_encrypted_size < required_size)
goto alloc_encrypted;
goto alloc_plaintext;
}
send_end:
ret = sk_stream_error(sk, msg->msg_flags, ret);
release_sock(sk);
return copied ? copied : ret;
}
int tls_sw_sendpage(struct sock *sk, struct page *page,
int offset, size_t size, int flags)
{
struct tls_context *tls_ctx = tls_get_ctx(sk);
struct tls_sw_context *ctx = tls_sw_ctx(tls_ctx);
int ret = 0;
long timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
bool eor;
size_t orig_size = size;
unsigned char record_type = TLS_RECORD_TYPE_DATA;
struct scatterlist *sg;
bool full_record;
int record_room;
if (flags & ~(MSG_MORE | MSG_DONTWAIT | MSG_NOSIGNAL |
MSG_SENDPAGE_NOTLAST))
return -ENOTSUPP;
/* No MSG_EOR from splice, only look at MSG_MORE */
eor = !(flags & (MSG_MORE | MSG_SENDPAGE_NOTLAST));
lock_sock(sk);
sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
if (tls_complete_pending_work(sk, tls_ctx, flags, &timeo))
goto sendpage_end;
/* Call the sk_stream functions to manage the sndbuf mem. */
while (size > 0) {
size_t copy, required_size;
if (sk->sk_err) {
ret = -sk->sk_err;
goto sendpage_end;
}
full_record = false;
record_room = TLS_MAX_PAYLOAD_SIZE - ctx->sg_plaintext_size;
copy = size;
if (copy >= record_room) {
copy = record_room;
full_record = true;
}
required_size = ctx->sg_plaintext_size + copy +
tls_ctx->overhead_size;
if (!sk_stream_memory_free(sk))
goto wait_for_sndbuf;
alloc_payload:
ret = alloc_encrypted_sg(sk, required_size);
if (ret) {
if (ret != -ENOSPC)
goto wait_for_memory;
/* Adjust copy according to the amount that was
* actually allocated. The difference is due
* to max sg elements limit
*/
copy -= required_size - ctx->sg_plaintext_size;
full_record = true;
}
get_page(page);
sg = ctx->sg_plaintext_data + ctx->sg_plaintext_num_elem;
sg_set_page(sg, page, copy, offset);
sg_unmark_end(sg);
ctx->sg_plaintext_num_elem++;
sk_mem_charge(sk, copy);
offset += copy;
size -= copy;
ctx->sg_plaintext_size += copy;
tls_ctx->pending_open_record_frags = ctx->sg_plaintext_num_elem;
if (full_record || eor ||
ctx->sg_plaintext_num_elem ==
ARRAY_SIZE(ctx->sg_plaintext_data)) {
push_record:
ret = tls_push_record(sk, flags, record_type);
if (ret) {
if (ret == -ENOMEM)
goto wait_for_memory;
goto sendpage_end;
}
}
continue;
wait_for_sndbuf:
set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
wait_for_memory:
ret = sk_stream_wait_memory(sk, &timeo);
if (ret) {
trim_both_sgl(sk, ctx->sg_plaintext_size);
goto sendpage_end;
}
if (tls_is_pending_closed_record(tls_ctx))
goto push_record;
goto alloc_payload;
}
sendpage_end:
if (orig_size > size)
ret = orig_size - size;
else
ret = sk_stream_error(sk, flags, ret);
release_sock(sk);
return ret;
}
void tls_sw_free_tx_resources(struct sock *sk)
{
struct tls_context *tls_ctx = tls_get_ctx(sk);
struct tls_sw_context *ctx = tls_sw_ctx(tls_ctx);
if (ctx->aead_send)
crypto_free_aead(ctx->aead_send);
tls_free_both_sg(sk);
kfree(ctx);
kfree(tls_ctx);
}
int tls_set_sw_offload(struct sock *sk, struct tls_context *ctx)
{
char keyval[TLS_CIPHER_AES_GCM_128_KEY_SIZE];
struct tls_crypto_info *crypto_info;
struct tls12_crypto_info_aes_gcm_128 *gcm_128_info;
struct tls_sw_context *sw_ctx;
u16 nonce_size, tag_size, iv_size, rec_seq_size;
char *iv, *rec_seq;
int rc = 0;
if (!ctx) {
rc = -EINVAL;
goto out;
}
if (ctx->priv_ctx) {
rc = -EEXIST;
goto out;
}
sw_ctx = kzalloc(sizeof(*sw_ctx), GFP_KERNEL);
if (!sw_ctx) {
rc = -ENOMEM;
goto out;
}
crypto_init_wait(&sw_ctx->async_wait);
ctx->priv_ctx = (struct tls_offload_context *)sw_ctx;
crypto_info = &ctx->crypto_send;
switch (crypto_info->cipher_type) {
case TLS_CIPHER_AES_GCM_128: {
nonce_size = TLS_CIPHER_AES_GCM_128_IV_SIZE;
tag_size = TLS_CIPHER_AES_GCM_128_TAG_SIZE;
iv_size = TLS_CIPHER_AES_GCM_128_IV_SIZE;
iv = ((struct tls12_crypto_info_aes_gcm_128 *)crypto_info)->iv;
rec_seq_size = TLS_CIPHER_AES_GCM_128_REC_SEQ_SIZE;
rec_seq =
((struct tls12_crypto_info_aes_gcm_128 *)crypto_info)->rec_seq;
gcm_128_info =
(struct tls12_crypto_info_aes_gcm_128 *)crypto_info;
break;
}
default:
rc = -EINVAL;
goto free_priv;
}
ctx->prepend_size = TLS_HEADER_SIZE + nonce_size;
ctx->tag_size = tag_size;
ctx->overhead_size = ctx->prepend_size + ctx->tag_size;
ctx->iv_size = iv_size;
ctx->iv = kmalloc(iv_size + TLS_CIPHER_AES_GCM_128_SALT_SIZE, GFP_KERNEL);
if (!ctx->iv) {
rc = -ENOMEM;
goto free_priv;
}
memcpy(ctx->iv, gcm_128_info->salt, TLS_CIPHER_AES_GCM_128_SALT_SIZE);
memcpy(ctx->iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE, iv, iv_size);
ctx->rec_seq_size = rec_seq_size;
ctx->rec_seq = kmalloc(rec_seq_size, GFP_KERNEL);
if (!ctx->rec_seq) {
rc = -ENOMEM;
goto free_iv;
}
memcpy(ctx->rec_seq, rec_seq, rec_seq_size);
sg_init_table(sw_ctx->sg_encrypted_data,
ARRAY_SIZE(sw_ctx->sg_encrypted_data));
sg_init_table(sw_ctx->sg_plaintext_data,
ARRAY_SIZE(sw_ctx->sg_plaintext_data));
sg_init_table(sw_ctx->sg_aead_in, 2);
sg_set_buf(&sw_ctx->sg_aead_in[0], sw_ctx->aad_space,
sizeof(sw_ctx->aad_space));
sg_unmark_end(&sw_ctx->sg_aead_in[1]);
sg_chain(sw_ctx->sg_aead_in, 2, sw_ctx->sg_plaintext_data);
sg_init_table(sw_ctx->sg_aead_out, 2);
sg_set_buf(&sw_ctx->sg_aead_out[0], sw_ctx->aad_space,
sizeof(sw_ctx->aad_space));
sg_unmark_end(&sw_ctx->sg_aead_out[1]);
sg_chain(sw_ctx->sg_aead_out, 2, sw_ctx->sg_encrypted_data);
if (!sw_ctx->aead_send) {
sw_ctx->aead_send = crypto_alloc_aead("gcm(aes)", 0, 0);
if (IS_ERR(sw_ctx->aead_send)) {
rc = PTR_ERR(sw_ctx->aead_send);
sw_ctx->aead_send = NULL;
goto free_rec_seq;
}
}
ctx->push_pending_record = tls_sw_push_pending_record;
memcpy(keyval, gcm_128_info->key, TLS_CIPHER_AES_GCM_128_KEY_SIZE);
rc = crypto_aead_setkey(sw_ctx->aead_send, keyval,
TLS_CIPHER_AES_GCM_128_KEY_SIZE);
if (rc)
goto free_aead;
rc = crypto_aead_setauthsize(sw_ctx->aead_send, ctx->tag_size);
if (!rc)
return 0;
free_aead:
crypto_free_aead(sw_ctx->aead_send);
sw_ctx->aead_send = NULL;
free_rec_seq:
kfree(ctx->rec_seq);
ctx->rec_seq = NULL;
free_iv:
kfree(ctx->iv);
ctx->iv = NULL;
free_priv:
kfree(ctx->priv_ctx);
ctx->priv_ctx = NULL;
out:
return rc;
}