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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/sched/signal.h>
#include <linux/module.h>
#include <crypto/aead.h>
#include <net/strparser.h>
#include <net/tls.h>
#define MAX_IV_SIZE TLS_CIPHER_AES_GCM_128_IV_SIZE
static int __skb_nsg(struct sk_buff *skb, int offset, int len,
unsigned int recursion_level)
{
int start = skb_headlen(skb);
int i, chunk = start - offset;
struct sk_buff *frag_iter;
int elt = 0;
if (unlikely(recursion_level >= 24))
return -EMSGSIZE;
if (chunk > 0) {
if (chunk > len)
chunk = len;
elt++;
len -= chunk;
if (len == 0)
return elt;
offset += chunk;
}
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
int end;
WARN_ON(start > offset + len);
end = start + skb_frag_size(&skb_shinfo(skb)->frags[i]);
chunk = end - offset;
if (chunk > 0) {
if (chunk > len)
chunk = len;
elt++;
len -= chunk;
if (len == 0)
return elt;
offset += chunk;
}
start = end;
}
if (unlikely(skb_has_frag_list(skb))) {
skb_walk_frags(skb, frag_iter) {
int end, ret;
WARN_ON(start > offset + len);
end = start + frag_iter->len;
chunk = end - offset;
if (chunk > 0) {
if (chunk > len)
chunk = len;
ret = __skb_nsg(frag_iter, offset - start, chunk,
recursion_level + 1);
if (unlikely(ret < 0))
return ret;
elt += ret;
len -= chunk;
if (len == 0)
return elt;
offset += chunk;
}
start = end;
}
}
BUG_ON(len);
return elt;
}
/* Return the number of scatterlist elements required to completely map the
* skb, or -EMSGSIZE if the recursion depth is exceeded.
*/
static int skb_nsg(struct sk_buff *skb, int offset, int len)
{
return __skb_nsg(skb, offset, len, 0);
}
static void tls_decrypt_done(struct crypto_async_request *req, int err)
{
struct aead_request *aead_req = (struct aead_request *)req;
struct decrypt_req_ctx *req_ctx =
(struct decrypt_req_ctx *)(aead_req + 1);
struct scatterlist *sgout = aead_req->dst;
struct tls_context *tls_ctx = tls_get_ctx(req_ctx->sk);
struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
int pending = atomic_dec_return(&ctx->decrypt_pending);
struct scatterlist *sg;
unsigned int pages;
/* Propagate if there was an err */
if (err) {
ctx->async_wait.err = err;
tls_err_abort(req_ctx->sk, err);
}
/* Release the skb, pages and memory allocated for crypto req */
kfree_skb(req->data);
/* Skip the first S/G entry as it points to AAD */
for_each_sg(sg_next(sgout), sg, UINT_MAX, pages) {
if (!sg)
break;
put_page(sg_page(sg));
}
kfree(aead_req);
if (!pending && READ_ONCE(ctx->async_notify))
complete(&ctx->async_wait.completion);
}
static int tls_do_decryption(struct sock *sk,
struct sk_buff *skb,
struct scatterlist *sgin,
struct scatterlist *sgout,
char *iv_recv,
size_t data_len,
struct aead_request *aead_req,
bool async)
{
struct tls_context *tls_ctx = tls_get_ctx(sk);
struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
int ret;
aead_request_set_tfm(aead_req, ctx->aead_recv);
aead_request_set_ad(aead_req, TLS_AAD_SPACE_SIZE);
aead_request_set_crypt(aead_req, sgin, sgout,
data_len + tls_ctx->rx.tag_size,
(u8 *)iv_recv);
if (async) {
struct decrypt_req_ctx *req_ctx;
req_ctx = (struct decrypt_req_ctx *)(aead_req + 1);
req_ctx->sk = sk;
aead_request_set_callback(aead_req,
CRYPTO_TFM_REQ_MAY_BACKLOG,
tls_decrypt_done, skb);
atomic_inc(&ctx->decrypt_pending);
} else {
aead_request_set_callback(aead_req,
CRYPTO_TFM_REQ_MAY_BACKLOG,
crypto_req_done, &ctx->async_wait);
}
ret = crypto_aead_decrypt(aead_req);
if (ret == -EINPROGRESS) {
if (async)
return ret;
ret = crypto_wait_req(ret, &ctx->async_wait);
}
if (async)
atomic_dec(&ctx->decrypt_pending);
return ret;
}
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_tx *ctx = tls_sw_ctx_tx(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->tx.overhead_size;
trim_sg(sk, ctx->sg_encrypted_data,
&ctx->sg_encrypted_num_elem,
&ctx->sg_encrypted_size,
target_size);
}
static int alloc_encrypted_sg(struct sock *sk, int len)
{
struct tls_context *tls_ctx = tls_get_ctx(sk);
struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
int rc = 0;
rc = sk_alloc_sg(sk, len,
ctx->sg_encrypted_data, 0,
&ctx->sg_encrypted_num_elem,
&ctx->sg_encrypted_size, 0);
if (rc == -ENOSPC)
ctx->sg_encrypted_num_elem = ARRAY_SIZE(ctx->sg_encrypted_data);
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_tx *ctx = tls_sw_ctx_tx(tls_ctx);
int rc = 0;
rc = sk_alloc_sg(sk, len, ctx->sg_plaintext_data, 0,
&ctx->sg_plaintext_num_elem, &ctx->sg_plaintext_size,
tls_ctx->pending_open_record_frags);
if (rc == -ENOSPC)
ctx->sg_plaintext_num_elem = ARRAY_SIZE(ctx->sg_plaintext_data);
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_tx *ctx = tls_sw_ctx_tx(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_tx *ctx,
struct aead_request *aead_req,
size_t data_len)
{
int rc;
ctx->sg_encrypted_data[0].offset += tls_ctx->tx.prepend_size;
ctx->sg_encrypted_data[0].length -= tls_ctx->tx.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->tx.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->tx.prepend_size;
ctx->sg_encrypted_data[0].length += tls_ctx->tx.prepend_size;
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_tx *ctx = tls_sw_ctx_tx(tls_ctx);
struct aead_request *req;
int rc;
req = aead_request_alloc(ctx->aead_send, sk->sk_allocation);
if (!req)
return -ENOMEM;
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->tx.rec_seq, tls_ctx->tx.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, req, ctx->sg_plaintext_size);
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);
goto out_req;
}
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, EBADMSG);
tls_advance_record_sn(sk, &tls_ctx->tx);
out_req:
aead_request_free(req);
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, int *pages_used,
unsigned int *size_used,
struct scatterlist *to, int to_max_pages,
bool charge)
{
struct page *pages[MAX_SKB_FRAGS];
size_t offset;
ssize_t copied, use;
int i = 0;
unsigned int size = *size_used;
int num_elem = *pages_used;
int rc = 0;
int maxpages;
while (length > 0) {
i = 0;
maxpages = to_max_pages - 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(&to[num_elem],
pages[i], use, offset);
sg_unmark_end(&to[num_elem]);
if (charge)
sk_mem_charge(sk, use);
offset = 0;
copied -= use;
++i;
++num_elem;
}
}
/* Mark the end in the last sg entry if newly added */
if (num_elem > *pages_used)
sg_mark_end(&to[num_elem - 1]);
out:
if (rc)
iov_iter_revert(from, size - *size_used);
*size_used = size;
*pages_used = 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_tx *ctx = tls_sw_ctx_tx(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_tx *ctx = tls_sw_ctx_tx(tls_ctx);
int ret;
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;
bool is_kvec = msg->msg_iter.type & ITER_KVEC;
if (msg->msg_flags & ~(MSG_MORE | MSG_DONTWAIT | MSG_NOSIGNAL))
return -ENOTSUPP;
lock_sock(sk);
ret = tls_complete_pending_work(sk, tls_ctx, msg->msg_flags, &timeo);
if (ret)
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->tx.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 (!is_kvec && (full_record || eor)) {
ret = zerocopy_from_iter(sk, &msg->msg_iter,
try_to_copy, &ctx->sg_plaintext_num_elem,
&ctx->sg_plaintext_size,
ctx->sg_plaintext_data,
ARRAY_SIZE(ctx->sg_plaintext_data),
true);
if (ret)
goto fallback_to_reg_send;
copied += try_to_copy;
ret = tls_push_record(sk, msg->msg_flags, record_type);
if (ret)
goto send_end;
continue;
fallback_to_reg_send:
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->tx.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_tx *ctx = tls_sw_ctx_tx(tls_ctx);
int ret;
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);
ret = tls_complete_pending_work(sk, tls_ctx, flags, &timeo);
if (ret)
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->tx.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;
}
static struct sk_buff *tls_wait_data(struct sock *sk, int flags,
long timeo, int *err)
{
struct tls_context *tls_ctx = tls_get_ctx(sk);
struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
struct sk_buff *skb;
DEFINE_WAIT_FUNC(wait, woken_wake_function);
while (!(skb = ctx->recv_pkt)) {
if (sk->sk_err) {
*err = sock_error(sk);
return NULL;
}
if (sk->sk_shutdown & RCV_SHUTDOWN)
return NULL;
if (sock_flag(sk, SOCK_DONE))
return NULL;
if ((flags & MSG_DONTWAIT) || !timeo) {
*err = -EAGAIN;
return NULL;
}
add_wait_queue(sk_sleep(sk), &wait);
sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
sk_wait_event(sk, &timeo, ctx->recv_pkt != skb, &wait);
sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
remove_wait_queue(sk_sleep(sk), &wait);
/* Handle signals */
if (signal_pending(current)) {
*err = sock_intr_errno(timeo);
return NULL;
}
}
return skb;
}
/* This function decrypts the input skb into either out_iov or in out_sg
* or in skb buffers itself. The input parameter 'zc' indicates if
* zero-copy mode needs to be tried or not. With zero-copy mode, either
* out_iov or out_sg must be non-NULL. In case both out_iov and out_sg are
* NULL, then the decryption happens inside skb buffers itself, i.e.
* zero-copy gets disabled and 'zc' is updated.
*/
static int decrypt_internal(struct sock *sk, struct sk_buff *skb,
struct iov_iter *out_iov,
struct scatterlist *out_sg,
int *chunk, bool *zc)
{
struct tls_context *tls_ctx = tls_get_ctx(sk);
struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
struct strp_msg *rxm = strp_msg(skb);
int n_sgin, n_sgout, nsg, mem_size, aead_size, err, pages = 0;
struct aead_request *aead_req;
struct sk_buff *unused;
u8 *aad, *iv, *mem = NULL;
struct scatterlist *sgin = NULL;
struct scatterlist *sgout = NULL;
const int data_len = rxm->full_len - tls_ctx->rx.overhead_size;
if (*zc && (out_iov || out_sg)) {
if (out_iov)
n_sgout = iov_iter_npages(out_iov, INT_MAX) + 1;
else
n_sgout = sg_nents(out_sg);
n_sgin = skb_nsg(skb, rxm->offset + tls_ctx->rx.prepend_size,
rxm->full_len - tls_ctx->rx.prepend_size);
} else {
n_sgout = 0;
*zc = false;
n_sgin = skb_cow_data(skb, 0, &unused);
}
if (n_sgin < 1)
return -EBADMSG;
/* Increment to accommodate AAD */
n_sgin = n_sgin + 1;
nsg = n_sgin + n_sgout;
aead_size = sizeof(*aead_req) + crypto_aead_reqsize(ctx->aead_recv);
mem_size = aead_size + (nsg * sizeof(struct scatterlist));
mem_size = mem_size + TLS_AAD_SPACE_SIZE;
mem_size = mem_size + crypto_aead_ivsize(ctx->aead_recv);
/* Allocate a single block of memory which contains
* aead_req || sgin[] || sgout[] || aad || iv.
* This order achieves correct alignment for aead_req, sgin, sgout.
*/
mem = kmalloc(mem_size, sk->sk_allocation);
if (!mem)
return -ENOMEM;
/* Segment the allocated memory */
aead_req = (struct aead_request *)mem;
sgin = (struct scatterlist *)(mem + aead_size);
sgout = sgin + n_sgin;
aad = (u8 *)(sgout + n_sgout);
iv = aad + TLS_AAD_SPACE_SIZE;
/* Prepare IV */
err = skb_copy_bits(skb, rxm->offset + TLS_HEADER_SIZE,
iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE,
tls_ctx->rx.iv_size);
if (err < 0) {
kfree(mem);
return err;
}
memcpy(iv, tls_ctx->rx.iv, TLS_CIPHER_AES_GCM_128_SALT_SIZE);
/* Prepare AAD */
tls_make_aad(aad, rxm->full_len - tls_ctx->rx.overhead_size,
tls_ctx->rx.rec_seq, tls_ctx->rx.rec_seq_size,
ctx->control);
/* Prepare sgin */
sg_init_table(sgin, n_sgin);
sg_set_buf(&sgin[0], aad, TLS_AAD_SPACE_SIZE);
err = skb_to_sgvec(skb, &sgin[1],
rxm->offset + tls_ctx->rx.prepend_size,
rxm->full_len - tls_ctx->rx.prepend_size);
if (err < 0) {
kfree(mem);
return err;
}
if (n_sgout) {
if (out_iov) {
sg_init_table(sgout, n_sgout);
sg_set_buf(&sgout[0], aad, TLS_AAD_SPACE_SIZE);
*chunk = 0;
err = zerocopy_from_iter(sk, out_iov, data_len, &pages,
chunk, &sgout[1],
(n_sgout - 1), false);
if (err < 0)
goto fallback_to_reg_recv;
} else if (out_sg) {
memcpy(sgout, out_sg, n_sgout * sizeof(*sgout));
} else {
goto fallback_to_reg_recv;
}
} else {
fallback_to_reg_recv:
sgout = sgin;
pages = 0;
*chunk = 0;
*zc = false;
}
/* Prepare and submit AEAD request */
err = tls_do_decryption(sk, skb, sgin, sgout, iv,
data_len, aead_req, *zc);
if (err == -EINPROGRESS)
return err;
/* Release the pages in case iov was mapped to pages */
for (; pages > 0; pages--)
put_page(sg_page(&sgout[pages]));
kfree(mem);
return err;
}
static int decrypt_skb_update(struct sock *sk, struct sk_buff *skb,
struct iov_iter *dest, int *chunk, bool *zc)
{
struct tls_context *tls_ctx = tls_get_ctx(sk);
struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
struct strp_msg *rxm = strp_msg(skb);
int err = 0;
#ifdef CONFIG_TLS_DEVICE
err = tls_device_decrypted(sk, skb);
if (err < 0)
return err;
#endif
if (!ctx->decrypted) {
err = decrypt_internal(sk, skb, dest, NULL, chunk, zc);
if (err < 0) {
if (err == -EINPROGRESS)
tls_advance_record_sn(sk, &tls_ctx->rx);
return err;
}
} else {
*zc = false;
}
rxm->offset += tls_ctx->rx.prepend_size;
rxm->full_len -= tls_ctx->rx.overhead_size;
tls_advance_record_sn(sk, &tls_ctx->rx);
ctx->decrypted = true;
ctx->saved_data_ready(sk);
return err;
}
int decrypt_skb(struct sock *sk, struct sk_buff *skb,
struct scatterlist *sgout)
{
bool zc = true;
int chunk;
return decrypt_internal(sk, skb, NULL, sgout, &chunk, &zc);
}
static bool tls_sw_advance_skb(struct sock *sk, struct sk_buff *skb,
unsigned int len)
{
struct tls_context *tls_ctx = tls_get_ctx(sk);
struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
if (skb) {
struct strp_msg *rxm = strp_msg(skb);
if (len < rxm->full_len) {
rxm->offset += len;
rxm->full_len -= len;
return false;
}
kfree_skb(skb);
}
/* Finished with message */
ctx->recv_pkt = NULL;
__strp_unpause(&ctx->strp);
return true;
}
int tls_sw_recvmsg(struct sock *sk,
struct msghdr *msg,
size_t len,
int nonblock,
int flags,
int *addr_len)
{
struct tls_context *tls_ctx = tls_get_ctx(sk);
struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
unsigned char control;
struct strp_msg *rxm;
struct sk_buff *skb;
ssize_t copied = 0;
bool cmsg = false;
int target, err = 0;
long timeo;
bool is_kvec = msg->msg_iter.type & ITER_KVEC;
int num_async = 0;
flags |= nonblock;
if (unlikely(flags & MSG_ERRQUEUE))
return sock_recv_errqueue(sk, msg, len, SOL_IP, IP_RECVERR);
lock_sock(sk);
target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
do {
bool zc = false;
bool async = false;
int chunk = 0;
skb = tls_wait_data(sk, flags, timeo, &err);
if (!skb)
goto recv_end;
rxm = strp_msg(skb);
if (!cmsg) {
int cerr;
cerr = put_cmsg(msg, SOL_TLS, TLS_GET_RECORD_TYPE,
sizeof(ctx->control), &ctx->control);
cmsg = true;
control = ctx->control;
if (ctx->control != TLS_RECORD_TYPE_DATA) {
if (cerr || msg->msg_flags & MSG_CTRUNC) {
err = -EIO;
goto recv_end;
}
}
} else if (control != ctx->control) {
goto recv_end;
}
if (!ctx->decrypted) {
int to_copy = rxm->full_len - tls_ctx->rx.overhead_size;
if (!is_kvec && to_copy <= len &&
likely(!(flags & MSG_PEEK)))
zc = true;
err = decrypt_skb_update(sk, skb, &msg->msg_iter,
&chunk, &zc);
if (err < 0 && err != -EINPROGRESS) {
tls_err_abort(sk, EBADMSG);
goto recv_end;
}
if (err == -EINPROGRESS) {
async = true;
num_async++;
goto pick_next_record;
}
ctx->decrypted = true;
}
if (!zc) {
chunk = min_t(unsigned int, rxm->full_len, len);
err = skb_copy_datagram_msg(skb, rxm->offset, msg,
chunk);
if (err < 0)
goto recv_end;
}
pick_next_record:
copied += chunk;
len -= chunk;
if (likely(!(flags & MSG_PEEK))) {
u8 control = ctx->control;
/* For async, drop current skb reference */
if (async)
skb = NULL;
if (tls_sw_advance_skb(sk, skb, chunk)) {
/* Return full control message to
* userspace before trying to parse
* another message type
*/
msg->msg_flags |= MSG_EOR;
if (control != TLS_RECORD_TYPE_DATA)
goto recv_end;
} else {
break;
}
}
/* If we have a new message from strparser, continue now. */
if (copied >= target && !ctx->recv_pkt)
break;
} while (len);
recv_end:
if (num_async) {
/* Wait for all previously submitted records to be decrypted */
smp_store_mb(ctx->async_notify, true);
if (atomic_read(&ctx->decrypt_pending)) {
err = crypto_wait_req(-EINPROGRESS, &ctx->async_wait);
if (err) {
/* one of async decrypt failed */
tls_err_abort(sk, err);
copied = 0;
}
} else {
reinit_completion(&ctx->async_wait.completion);
}
WRITE_ONCE(ctx->async_notify, false);
}
release_sock(sk);
return copied ? : err;
}
ssize_t tls_sw_splice_read(struct socket *sock, loff_t *ppos,
struct pipe_inode_info *pipe,
size_t len, unsigned int flags)
{
struct tls_context *tls_ctx = tls_get_ctx(sock->sk);
struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
struct strp_msg *rxm = NULL;
struct sock *sk = sock->sk;
struct sk_buff *skb;
ssize_t copied = 0;
int err = 0;
long timeo;
int chunk;
bool zc = false;
lock_sock(sk);
timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
skb = tls_wait_data(sk, flags, timeo, &err);
if (!skb)
goto splice_read_end;
/* splice does not support reading control messages */
if (ctx->control != TLS_RECORD_TYPE_DATA) {
err = -ENOTSUPP;
goto splice_read_end;
}
if (!ctx->decrypted) {
err = decrypt_skb_update(sk, skb, NULL, &chunk, &zc);
if (err < 0) {
tls_err_abort(sk, EBADMSG);
goto splice_read_end;
}
ctx->decrypted = true;
}
rxm = strp_msg(skb);
chunk = min_t(unsigned int, rxm->full_len, len);
copied = skb_splice_bits(skb, sk, rxm->offset, pipe, chunk, flags);
if (copied < 0)
goto splice_read_end;
if (likely(!(flags & MSG_PEEK)))
tls_sw_advance_skb(sk, skb, copied);
splice_read_end:
release_sock(sk);
return copied ? : err;
}
unsigned int tls_sw_poll(struct file *file, struct socket *sock,
struct poll_table_struct *wait)
{
unsigned int ret;
struct sock *sk = sock->sk;
struct tls_context *tls_ctx = tls_get_ctx(sk);
struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
/* Grab POLLOUT and POLLHUP from the underlying socket */
ret = ctx->sk_poll(file, sock, wait);
/* Clear POLLIN bits, and set based on recv_pkt */
ret &= ~(POLLIN | POLLRDNORM);
if (ctx->recv_pkt)
ret |= POLLIN | POLLRDNORM;
return ret;
}
static int tls_read_size(struct strparser *strp, struct sk_buff *skb)
{
struct tls_context *tls_ctx = tls_get_ctx(strp->sk);
struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
char header[TLS_HEADER_SIZE + MAX_IV_SIZE];
struct strp_msg *rxm = strp_msg(skb);
size_t cipher_overhead;
size_t data_len = 0;
int ret;
/* Verify that we have a full TLS header, or wait for more data */
if (rxm->offset + tls_ctx->rx.prepend_size > skb->len)
return 0;
/* Sanity-check size of on-stack buffer. */
if (WARN_ON(tls_ctx->rx.prepend_size > sizeof(header))) {
ret = -EINVAL;
goto read_failure;
}
/* Linearize header to local buffer */
ret = skb_copy_bits(skb, rxm->offset, header, tls_ctx->rx.prepend_size);
if (ret < 0)
goto read_failure;
ctx->control = header[0];
data_len = ((header[4] & 0xFF) | (header[3] << 8));
cipher_overhead = tls_ctx->rx.tag_size + tls_ctx->rx.iv_size;
if (data_len > TLS_MAX_PAYLOAD_SIZE + cipher_overhead) {
ret = -EMSGSIZE;
goto read_failure;
}
if (data_len < cipher_overhead) {
ret = -EBADMSG;
goto read_failure;
}
if (header[1] != TLS_VERSION_MINOR(tls_ctx->crypto_recv.version) ||
header[2] != TLS_VERSION_MAJOR(tls_ctx->crypto_recv.version)) {
ret = -EINVAL;
goto read_failure;
}
#ifdef CONFIG_TLS_DEVICE
handle_device_resync(strp->sk, TCP_SKB_CB(skb)->seq + rxm->offset,
*(u64*)tls_ctx->rx.rec_seq);
#endif
return data_len + TLS_HEADER_SIZE;
read_failure:
tls_err_abort(strp->sk, ret);
return ret;
}
static void tls_queue(struct strparser *strp, struct sk_buff *skb)
{
struct tls_context *tls_ctx = tls_get_ctx(strp->sk);
struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
ctx->decrypted = false;
ctx->recv_pkt = skb;
strp_pause(strp);
ctx->saved_data_ready(strp->sk);
}
static void tls_data_ready(struct sock *sk)
{
struct tls_context *tls_ctx = tls_get_ctx(sk);
struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
strp_data_ready(&ctx->strp);
}
void tls_sw_free_resources_tx(struct sock *sk)
{
struct tls_context *tls_ctx = tls_get_ctx(sk);
struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
crypto_free_aead(ctx->aead_send);
tls_free_both_sg(sk);
kfree(ctx);
}
void tls_sw_release_resources_rx(struct sock *sk)
{
struct tls_context *tls_ctx = tls_get_ctx(sk);
struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
if (ctx->aead_recv) {
kfree_skb(ctx->recv_pkt);
ctx->recv_pkt = NULL;
crypto_free_aead(ctx->aead_recv);
strp_stop(&ctx->strp);
write_lock_bh(&sk->sk_callback_lock);
sk->sk_data_ready = ctx->saved_data_ready;
write_unlock_bh(&sk->sk_callback_lock);
release_sock(sk);
strp_done(&ctx->strp);
lock_sock(sk);
}
}
void tls_sw_free_resources_rx(struct sock *sk)
{
struct tls_context *tls_ctx = tls_get_ctx(sk);
struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
tls_sw_release_resources_rx(sk);
kfree(ctx);
}
int tls_set_sw_offload(struct sock *sk, struct tls_context *ctx, int tx)
{
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_tx *sw_ctx_tx = NULL;
struct tls_sw_context_rx *sw_ctx_rx = NULL;
struct cipher_context *cctx;
struct crypto_aead **aead;
struct strp_callbacks cb;
u16 nonce_size, tag_size, iv_size, rec_seq_size;
char *iv, *rec_seq;
int rc = 0;
if (!ctx) {
rc = -EINVAL;
goto out;
}
if (tx) {
if (!ctx->priv_ctx_tx) {
sw_ctx_tx = kzalloc(sizeof(*sw_ctx_tx), GFP_KERNEL);
if (!sw_ctx_tx) {
rc = -ENOMEM;
goto out;
}
ctx->priv_ctx_tx = sw_ctx_tx;
} else {
sw_ctx_tx =
(struct tls_sw_context_tx *)ctx->priv_ctx_tx;
}
} else {
if (!ctx->priv_ctx_rx) {
sw_ctx_rx = kzalloc(sizeof(*sw_ctx_rx), GFP_KERNEL);
if (!sw_ctx_rx) {
rc = -ENOMEM;
goto out;
}
ctx->priv_ctx_rx = sw_ctx_rx;
} else {
sw_ctx_rx =
(struct tls_sw_context_rx *)ctx->priv_ctx_rx;
}
}
if (tx) {
crypto_init_wait(&sw_ctx_tx->async_wait);
crypto_info = &ctx->crypto_send;
cctx = &ctx->tx;
aead = &sw_ctx_tx->aead_send;
} else {
crypto_init_wait(&sw_ctx_rx->async_wait);
crypto_info = &ctx->crypto_recv;
cctx = &ctx->rx;
aead = &sw_ctx_rx->aead_recv;
}
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;
}
/* Sanity-check the IV size for stack allocations. */
if (iv_size > MAX_IV_SIZE || nonce_size > MAX_IV_SIZE) {
rc = -EINVAL;
goto free_priv;
}
cctx->prepend_size = TLS_HEADER_SIZE + nonce_size;
cctx->tag_size = tag_size;
cctx->overhead_size = cctx->prepend_size + cctx->tag_size;
cctx->iv_size = iv_size;
cctx->iv = kmalloc(iv_size + TLS_CIPHER_AES_GCM_128_SALT_SIZE,
GFP_KERNEL);
if (!cctx->iv) {
rc = -ENOMEM;
goto free_priv;
}
memcpy(cctx->iv, gcm_128_info->salt, TLS_CIPHER_AES_GCM_128_SALT_SIZE);
memcpy(cctx->iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE, iv, iv_size);
cctx->rec_seq_size = rec_seq_size;
cctx->rec_seq = kmemdup(rec_seq, rec_seq_size, GFP_KERNEL);
if (!cctx->rec_seq) {
rc = -ENOMEM;
goto free_iv;
}
if (sw_ctx_tx) {
sg_init_table(sw_ctx_tx->sg_encrypted_data,
ARRAY_SIZE(sw_ctx_tx->sg_encrypted_data));
sg_init_table(sw_ctx_tx->sg_plaintext_data,
ARRAY_SIZE(sw_ctx_tx->sg_plaintext_data));
sg_init_table(sw_ctx_tx->sg_aead_in, 2);
sg_set_buf(&sw_ctx_tx->sg_aead_in[0], sw_ctx_tx->aad_space,
sizeof(sw_ctx_tx->aad_space));
sg_unmark_end(&sw_ctx_tx->sg_aead_in[1]);
sg_chain(sw_ctx_tx->sg_aead_in, 2,
sw_ctx_tx->sg_plaintext_data);
sg_init_table(sw_ctx_tx->sg_aead_out, 2);
sg_set_buf(&sw_ctx_tx->sg_aead_out[0], sw_ctx_tx->aad_space,
sizeof(sw_ctx_tx->aad_space));
sg_unmark_end(&sw_ctx_tx->sg_aead_out[1]);
sg_chain(sw_ctx_tx->sg_aead_out, 2,
sw_ctx_tx->sg_encrypted_data);
}
if (!*aead) {
*aead = crypto_alloc_aead("gcm(aes)", 0, 0);
if (IS_ERR(*aead)) {
rc = PTR_ERR(*aead);
*aead = 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(*aead, keyval,
TLS_CIPHER_AES_GCM_128_KEY_SIZE);
if (rc)
goto free_aead;
rc = crypto_aead_setauthsize(*aead, cctx->tag_size);
if (rc)
goto free_aead;
if (sw_ctx_rx) {
(*aead)->reqsize = sizeof(struct decrypt_req_ctx);
/* Set up strparser */
memset(&cb, 0, sizeof(cb));
cb.rcv_msg = tls_queue;
cb.parse_msg = tls_read_size;
strp_init(&sw_ctx_rx->strp, sk, &cb);
write_lock_bh(&sk->sk_callback_lock);
sw_ctx_rx->saved_data_ready = sk->sk_data_ready;
sk->sk_data_ready = tls_data_ready;
write_unlock_bh(&sk->sk_callback_lock);
sw_ctx_rx->sk_poll = sk->sk_socket->ops->poll;
strp_check_rcv(&sw_ctx_rx->strp);
}
goto out;
free_aead:
crypto_free_aead(*aead);
*aead = NULL;
free_rec_seq:
kfree(cctx->rec_seq);
cctx->rec_seq = NULL;
free_iv:
kfree(cctx->iv);
cctx->iv = NULL;
free_priv:
if (tx) {
kfree(ctx->priv_ctx_tx);
ctx->priv_ctx_tx = NULL;
} else {
kfree(ctx->priv_ctx_rx);
ctx->priv_ctx_rx = NULL;
}
out:
return rc;
}
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