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linux/net/tls/tls_sw.c
Sascha Hauer 54001d0f2f net: tls: wait for async completion on last message 
When asynchronous encryption is used KTLS sends out the final data at
proto->close time. This becomes problematic when the task calling
close() receives a signal. In this case it can happen that
tcp_sendmsg_locked() called at close time returns -ERESTARTSYS and the
final data is not sent.

The described situation happens when KTLS is used in conjunction with
io_uring, as io_uring uses task_work_add() to add work to the current
userspace task. A discussion of the problem along with a reproducer can
be found in [1] and [2]

Fix this by waiting for the asynchronous encryption to be completed on
the final message. With this there is no data left to be sent at close
time.

[1] https://lore.kernel.org/all/20231010141932.GD3114228@pengutronix.de/
[2] https://lore.kernel.org/all/20240315100159.3898944-1-s.hauer@pengutronix.de/

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Link: https://patch.msgid.link/20240904-ktls-wait-async-v1-1-a62892833110@pengutronix.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-06 18:20:55 -07:00

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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.
* Copyright (c) 2018, Covalent IO, Inc. http://covalent.io
*
* 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/bug.h>
#include <linux/sched/signal.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/splice.h>
#include <crypto/aead.h>
#include <net/strparser.h>
#include <net/tls.h>
#include <trace/events/sock.h>
#include "tls.h"
struct tls_decrypt_arg {
struct_group(inargs,
bool zc;
bool async;
bool async_done;
u8 tail;
);
struct sk_buff *skb;
};
struct tls_decrypt_ctx {
struct sock *sk;
u8 iv[TLS_MAX_IV_SIZE];
u8 aad[TLS_MAX_AAD_SIZE];
u8 tail;
bool free_sgout;
struct scatterlist sg[];
};
noinline void tls_err_abort(struct sock *sk, int err)
{
WARN_ON_ONCE(err >= 0);
/* sk->sk_err should contain a positive error code. */
WRITE_ONCE(sk->sk_err, -err);
/* Paired with smp_rmb() in tcp_poll() */
smp_wmb();
sk_error_report(sk);
}
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 int tls_padding_length(struct tls_prot_info *prot, struct sk_buff *skb,
struct tls_decrypt_arg *darg)
{
struct strp_msg *rxm = strp_msg(skb);
struct tls_msg *tlm = tls_msg(skb);
int sub = 0;
/* Determine zero-padding length */
if (prot->version == TLS_1_3_VERSION) {
int offset = rxm->full_len - TLS_TAG_SIZE - 1;
char content_type = darg->zc ? darg->tail : 0;
int err;
while (content_type == 0) {
if (offset < prot->prepend_size)
return -EBADMSG;
err = skb_copy_bits(skb, rxm->offset + offset,
&content_type, 1);
if (err)
return err;
if (content_type)
break;
sub++;
offset--;
}
tlm->control = content_type;
}
return sub;
}
static void tls_decrypt_done(void *data, int err)
{
struct aead_request *aead_req = data;
struct crypto_aead *aead = crypto_aead_reqtfm(aead_req);
struct scatterlist *sgout = aead_req->dst;
struct tls_sw_context_rx *ctx;
struct tls_decrypt_ctx *dctx;
struct tls_context *tls_ctx;
struct scatterlist *sg;
unsigned int pages;
struct sock *sk;
int aead_size;
/* If requests get too backlogged crypto API returns -EBUSY and calls
* ->complete(-EINPROGRESS) immediately followed by ->complete(0)
* to make waiting for backlog to flush with crypto_wait_req() easier.
* First wait converts -EBUSY -> -EINPROGRESS, and the second one
* -EINPROGRESS -> 0.
* We have a single struct crypto_async_request per direction, this
* scheme doesn't help us, so just ignore the first ->complete().
*/
if (err == -EINPROGRESS)
return;
aead_size = sizeof(*aead_req) + crypto_aead_reqsize(aead);
aead_size = ALIGN(aead_size, __alignof__(*dctx));
dctx = (void *)((u8 *)aead_req + aead_size);
sk = dctx->sk;
tls_ctx = tls_get_ctx(sk);
ctx = tls_sw_ctx_rx(tls_ctx);
/* Propagate if there was an err */
if (err) {
if (err == -EBADMSG)
TLS_INC_STATS(sock_net(sk), LINUX_MIB_TLSDECRYPTERROR);
ctx->async_wait.err = err;
tls_err_abort(sk, err);
}
/* Free the destination pages if skb was not decrypted inplace */
if (dctx->free_sgout) {
/* 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 (atomic_dec_and_test(&ctx->decrypt_pending))
complete(&ctx->async_wait.completion);
}
static int tls_decrypt_async_wait(struct tls_sw_context_rx *ctx)
{
if (!atomic_dec_and_test(&ctx->decrypt_pending))
crypto_wait_req(-EINPROGRESS, &ctx->async_wait);
atomic_inc(&ctx->decrypt_pending);
return ctx->async_wait.err;
}
static int tls_do_decryption(struct sock *sk,
struct scatterlist *sgin,
struct scatterlist *sgout,
char *iv_recv,
size_t data_len,
struct aead_request *aead_req,
struct tls_decrypt_arg *darg)
{
struct tls_context *tls_ctx = tls_get_ctx(sk);
struct tls_prot_info *prot = &tls_ctx->prot_info;
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, prot->aad_size);
aead_request_set_crypt(aead_req, sgin, sgout,
data_len + prot->tag_size,
(u8 *)iv_recv);
if (darg->async) {
aead_request_set_callback(aead_req,
CRYPTO_TFM_REQ_MAY_BACKLOG,
tls_decrypt_done, aead_req);
DEBUG_NET_WARN_ON_ONCE(atomic_read(&ctx->decrypt_pending) < 1);
atomic_inc(&ctx->decrypt_pending);
} else {
DECLARE_CRYPTO_WAIT(wait);
aead_request_set_callback(aead_req,
CRYPTO_TFM_REQ_MAY_BACKLOG,
crypto_req_done, &wait);
ret = crypto_aead_decrypt(aead_req);
if (ret == -EINPROGRESS || ret == -EBUSY)
ret = crypto_wait_req(ret, &wait);
return ret;
}
ret = crypto_aead_decrypt(aead_req);
if (ret == -EINPROGRESS)
return 0;
if (ret == -EBUSY) {
ret = tls_decrypt_async_wait(ctx);
darg->async_done = true;
/* all completions have run, we're not doing async anymore */
darg->async = false;
return ret;
}
atomic_dec(&ctx->decrypt_pending);
darg->async = false;
return ret;
}
static void tls_trim_both_msgs(struct sock *sk, int target_size)
{
struct tls_context *tls_ctx = tls_get_ctx(sk);
struct tls_prot_info *prot = &tls_ctx->prot_info;
struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
struct tls_rec *rec = ctx->open_rec;
sk_msg_trim(sk, &rec->msg_plaintext, target_size);
if (target_size > 0)
target_size += prot->overhead_size;
sk_msg_trim(sk, &rec->msg_encrypted, target_size);
}
static int tls_alloc_encrypted_msg(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);
struct tls_rec *rec = ctx->open_rec;
struct sk_msg *msg_en = &rec->msg_encrypted;
return sk_msg_alloc(sk, msg_en, len, 0);
}
static int tls_clone_plaintext_msg(struct sock *sk, int required)
{
struct tls_context *tls_ctx = tls_get_ctx(sk);
struct tls_prot_info *prot = &tls_ctx->prot_info;
struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
struct tls_rec *rec = ctx->open_rec;
struct sk_msg *msg_pl = &rec->msg_plaintext;
struct sk_msg *msg_en = &rec->msg_encrypted;
int skip, len;
/* We add page references worth len bytes from encrypted sg
* at the end of plaintext sg. It is guaranteed that msg_en
* has enough required room (ensured by caller).
*/
len = required - msg_pl->sg.size;
/* Skip initial bytes in msg_en's data to be able to use
* same offset of both plain and encrypted data.
*/
skip = prot->prepend_size + msg_pl->sg.size;
return sk_msg_clone(sk, msg_pl, msg_en, skip, len);
}
static struct tls_rec *tls_get_rec(struct sock *sk)
{
struct tls_context *tls_ctx = tls_get_ctx(sk);
struct tls_prot_info *prot = &tls_ctx->prot_info;
struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
struct sk_msg *msg_pl, *msg_en;
struct tls_rec *rec;
int mem_size;
mem_size = sizeof(struct tls_rec) + crypto_aead_reqsize(ctx->aead_send);
rec = kzalloc(mem_size, sk->sk_allocation);
if (!rec)
return NULL;
msg_pl = &rec->msg_plaintext;
msg_en = &rec->msg_encrypted;
sk_msg_init(msg_pl);
sk_msg_init(msg_en);
sg_init_table(rec->sg_aead_in, 2);
sg_set_buf(&rec->sg_aead_in[0], rec->aad_space, prot->aad_size);
sg_unmark_end(&rec->sg_aead_in[1]);
sg_init_table(rec->sg_aead_out, 2);
sg_set_buf(&rec->sg_aead_out[0], rec->aad_space, prot->aad_size);
sg_unmark_end(&rec->sg_aead_out[1]);
rec->sk = sk;
return rec;
}
static void tls_free_rec(struct sock *sk, struct tls_rec *rec)
{
sk_msg_free(sk, &rec->msg_encrypted);
sk_msg_free(sk, &rec->msg_plaintext);
kfree(rec);
}
static void tls_free_open_rec(struct sock *sk)
{
struct tls_context *tls_ctx = tls_get_ctx(sk);
struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
struct tls_rec *rec = ctx->open_rec;
if (rec) {
tls_free_rec(sk, rec);
ctx->open_rec = NULL;
}
}
int tls_tx_records(struct sock *sk, int flags)
{
struct tls_context *tls_ctx = tls_get_ctx(sk);
struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
struct tls_rec *rec, *tmp;
struct sk_msg *msg_en;
int tx_flags, rc = 0;
if (tls_is_partially_sent_record(tls_ctx)) {
rec = list_first_entry(&ctx->tx_list,
struct tls_rec, list);
if (flags == -1)
tx_flags = rec->tx_flags;
else
tx_flags = flags;
rc = tls_push_partial_record(sk, tls_ctx, tx_flags);
if (rc)
goto tx_err;
/* Full record has been transmitted.
* Remove the head of tx_list
*/
list_del(&rec->list);
sk_msg_free(sk, &rec->msg_plaintext);
kfree(rec);
}
/* Tx all ready records */
list_for_each_entry_safe(rec, tmp, &ctx->tx_list, list) {
if (READ_ONCE(rec->tx_ready)) {
if (flags == -1)
tx_flags = rec->tx_flags;
else
tx_flags = flags;
msg_en = &rec->msg_encrypted;
rc = tls_push_sg(sk, tls_ctx,
&msg_en->sg.data[msg_en->sg.curr],
0, tx_flags);
if (rc)
goto tx_err;
list_del(&rec->list);
sk_msg_free(sk, &rec->msg_plaintext);
kfree(rec);
} else {
break;
}
}
tx_err:
if (rc < 0 && rc != -EAGAIN)
tls_err_abort(sk, -EBADMSG);
return rc;
}
static void tls_encrypt_done(void *data, int err)
{
struct tls_sw_context_tx *ctx;
struct tls_context *tls_ctx;
struct tls_prot_info *prot;
struct tls_rec *rec = data;
struct scatterlist *sge;
struct sk_msg *msg_en;
struct sock *sk;
if (err == -EINPROGRESS) /* see the comment in tls_decrypt_done() */
return;
msg_en = &rec->msg_encrypted;
sk = rec->sk;
tls_ctx = tls_get_ctx(sk);
prot = &tls_ctx->prot_info;
ctx = tls_sw_ctx_tx(tls_ctx);
sge = sk_msg_elem(msg_en, msg_en->sg.curr);
sge->offset -= prot->prepend_size;
sge->length += prot->prepend_size;
/* Check if error is previously set on socket */
if (err || sk->sk_err) {
rec = NULL;
/* If err is already set on socket, return the same code */
if (sk->sk_err) {
ctx->async_wait.err = -sk->sk_err;
} else {
ctx->async_wait.err = err;
tls_err_abort(sk, err);
}
}
if (rec) {
struct tls_rec *first_rec;
/* Mark the record as ready for transmission */
smp_store_mb(rec->tx_ready, true);
/* If received record is at head of tx_list, schedule tx */
first_rec = list_first_entry(&ctx->tx_list,
struct tls_rec, list);
if (rec == first_rec) {
/* Schedule the transmission */
if (!test_and_set_bit(BIT_TX_SCHEDULED,
&ctx->tx_bitmask))
schedule_delayed_work(&ctx->tx_work.work, 1);
}
}
if (atomic_dec_and_test(&ctx->encrypt_pending))
complete(&ctx->async_wait.completion);
}
static int tls_encrypt_async_wait(struct tls_sw_context_tx *ctx)
{
if (!atomic_dec_and_test(&ctx->encrypt_pending))
crypto_wait_req(-EINPROGRESS, &ctx->async_wait);
atomic_inc(&ctx->encrypt_pending);
return ctx->async_wait.err;
}
static int tls_do_encryption(struct sock *sk,
struct tls_context *tls_ctx,
struct tls_sw_context_tx *ctx,
struct aead_request *aead_req,
size_t data_len, u32 start)
{
struct tls_prot_info *prot = &tls_ctx->prot_info;
struct tls_rec *rec = ctx->open_rec;
struct sk_msg *msg_en = &rec->msg_encrypted;
struct scatterlist *sge = sk_msg_elem(msg_en, start);
int rc, iv_offset = 0;
/* For CCM based ciphers, first byte of IV is a constant */
switch (prot->cipher_type) {
case TLS_CIPHER_AES_CCM_128:
rec->iv_data[0] = TLS_AES_CCM_IV_B0_BYTE;
iv_offset = 1;
break;
case TLS_CIPHER_SM4_CCM:
rec->iv_data[0] = TLS_SM4_CCM_IV_B0_BYTE;
iv_offset = 1;
break;
}
memcpy(&rec->iv_data[iv_offset], tls_ctx->tx.iv,
prot->iv_size + prot->salt_size);
tls_xor_iv_with_seq(prot, rec->iv_data + iv_offset,
tls_ctx->tx.rec_seq);
sge->offset += prot->prepend_size;
sge->length -= prot->prepend_size;
msg_en->sg.curr = start;
aead_request_set_tfm(aead_req, ctx->aead_send);
aead_request_set_ad(aead_req, prot->aad_size);
aead_request_set_crypt(aead_req, rec->sg_aead_in,
rec->sg_aead_out,
data_len, rec->iv_data);
aead_request_set_callback(aead_req, CRYPTO_TFM_REQ_MAY_BACKLOG,
tls_encrypt_done, rec);
/* Add the record in tx_list */
list_add_tail((struct list_head *)&rec->list, &ctx->tx_list);
DEBUG_NET_WARN_ON_ONCE(atomic_read(&ctx->encrypt_pending) < 1);
atomic_inc(&ctx->encrypt_pending);
rc = crypto_aead_encrypt(aead_req);
if (rc == -EBUSY) {
rc = tls_encrypt_async_wait(ctx);
rc = rc ?: -EINPROGRESS;
}
if (!rc || rc != -EINPROGRESS) {
atomic_dec(&ctx->encrypt_pending);
sge->offset -= prot->prepend_size;
sge->length += prot->prepend_size;
}
if (!rc) {
WRITE_ONCE(rec->tx_ready, true);
} else if (rc != -EINPROGRESS) {
list_del(&rec->list);
return rc;
}
/* Unhook the record from context if encryption is not failure */
ctx->open_rec = NULL;
tls_advance_record_sn(sk, prot, &tls_ctx->tx);
return rc;
}
static int tls_split_open_record(struct sock *sk, struct tls_rec *from,
struct tls_rec **to, struct sk_msg *msg_opl,
struct sk_msg *msg_oen, u32 split_point,
u32 tx_overhead_size, u32 *orig_end)
{
u32 i, j, bytes = 0, apply = msg_opl->apply_bytes;
struct scatterlist *sge, *osge, *nsge;
u32 orig_size = msg_opl->sg.size;
struct scatterlist tmp = { };
struct sk_msg *msg_npl;
struct tls_rec *new;
int ret;
new = tls_get_rec(sk);
if (!new)
return -ENOMEM;
ret = sk_msg_alloc(sk, &new->msg_encrypted, msg_opl->sg.size +
tx_overhead_size, 0);
if (ret < 0) {
tls_free_rec(sk, new);
return ret;
}
*orig_end = msg_opl->sg.end;
i = msg_opl->sg.start;
sge = sk_msg_elem(msg_opl, i);
while (apply && sge->length) {
if (sge->length > apply) {
u32 len = sge->length - apply;
get_page(sg_page(sge));
sg_set_page(&tmp, sg_page(sge), len,
sge->offset + apply);
sge->length = apply;
bytes += apply;
apply = 0;
} else {
apply -= sge->length;
bytes += sge->length;
}
sk_msg_iter_var_next(i);
if (i == msg_opl->sg.end)
break;
sge = sk_msg_elem(msg_opl, i);
}
msg_opl->sg.end = i;
msg_opl->sg.curr = i;
msg_opl->sg.copybreak = 0;
msg_opl->apply_bytes = 0;
msg_opl->sg.size = bytes;
msg_npl = &new->msg_plaintext;
msg_npl->apply_bytes = apply;
msg_npl->sg.size = orig_size - bytes;
j = msg_npl->sg.start;
nsge = sk_msg_elem(msg_npl, j);
if (tmp.length) {
memcpy(nsge, &tmp, sizeof(*nsge));
sk_msg_iter_var_next(j);
nsge = sk_msg_elem(msg_npl, j);
}
osge = sk_msg_elem(msg_opl, i);
while (osge->length) {
memcpy(nsge, osge, sizeof(*nsge));
sg_unmark_end(nsge);
sk_msg_iter_var_next(i);
sk_msg_iter_var_next(j);
if (i == *orig_end)
break;
osge = sk_msg_elem(msg_opl, i);
nsge = sk_msg_elem(msg_npl, j);
}
msg_npl->sg.end = j;
msg_npl->sg.curr = j;
msg_npl->sg.copybreak = 0;
*to = new;
return 0;
}
static void tls_merge_open_record(struct sock *sk, struct tls_rec *to,
struct tls_rec *from, u32 orig_end)
{
struct sk_msg *msg_npl = &from->msg_plaintext;
struct sk_msg *msg_opl = &to->msg_plaintext;
struct scatterlist *osge, *nsge;
u32 i, j;
i = msg_opl->sg.end;
sk_msg_iter_var_prev(i);
j = msg_npl->sg.start;
osge = sk_msg_elem(msg_opl, i);
nsge = sk_msg_elem(msg_npl, j);
if (sg_page(osge) == sg_page(nsge) &&
osge->offset + osge->length == nsge->offset) {
osge->length += nsge->length;
put_page(sg_page(nsge));
}
msg_opl->sg.end = orig_end;
msg_opl->sg.curr = orig_end;
msg_opl->sg.copybreak = 0;
msg_opl->apply_bytes = msg_opl->sg.size + msg_npl->sg.size;
msg_opl->sg.size += msg_npl->sg.size;
sk_msg_free(sk, &to->msg_encrypted);
sk_msg_xfer_full(&to->msg_encrypted, &from->msg_encrypted);
kfree(from);
}
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_prot_info *prot = &tls_ctx->prot_info;
struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
struct tls_rec *rec = ctx->open_rec, *tmp = NULL;
u32 i, split_point, orig_end;
struct sk_msg *msg_pl, *msg_en;
struct aead_request *req;
bool split;
int rc;
if (!rec)
return 0;
msg_pl = &rec->msg_plaintext;
msg_en = &rec->msg_encrypted;
split_point = msg_pl->apply_bytes;
split = split_point && split_point < msg_pl->sg.size;
if (unlikely((!split &&
msg_pl->sg.size +
prot->overhead_size > msg_en->sg.size) ||
(split &&
split_point +
prot->overhead_size > msg_en->sg.size))) {
split = true;
split_point = msg_en->sg.size;
}
if (split) {
rc = tls_split_open_record(sk, rec, &tmp, msg_pl, msg_en,
split_point, prot->overhead_size,
&orig_end);
if (rc < 0)
return rc;
/* This can happen if above tls_split_open_record allocates
* a single large encryption buffer instead of two smaller
* ones. In this case adjust pointers and continue without
* split.
*/
if (!msg_pl->sg.size) {
tls_merge_open_record(sk, rec, tmp, orig_end);
msg_pl = &rec->msg_plaintext;
msg_en = &rec->msg_encrypted;
split = false;
}
sk_msg_trim(sk, msg_en, msg_pl->sg.size +
prot->overhead_size);
}
rec->tx_flags = flags;
req = &rec->aead_req;
i = msg_pl->sg.end;
sk_msg_iter_var_prev(i);
rec->content_type = record_type;
if (prot->version == TLS_1_3_VERSION) {
/* Add content type to end of message. No padding added */
sg_set_buf(&rec->sg_content_type, &rec->content_type, 1);
sg_mark_end(&rec->sg_content_type);
sg_chain(msg_pl->sg.data, msg_pl->sg.end + 1,
&rec->sg_content_type);
} else {
sg_mark_end(sk_msg_elem(msg_pl, i));
}
if (msg_pl->sg.end < msg_pl->sg.start) {
sg_chain(&msg_pl->sg.data[msg_pl->sg.start],
MAX_SKB_FRAGS - msg_pl->sg.start + 1,
msg_pl->sg.data);
}
i = msg_pl->sg.start;
sg_chain(rec->sg_aead_in, 2, &msg_pl->sg.data[i]);
i = msg_en->sg.end;
sk_msg_iter_var_prev(i);
sg_mark_end(sk_msg_elem(msg_en, i));
i = msg_en->sg.start;
sg_chain(rec->sg_aead_out, 2, &msg_en->sg.data[i]);
tls_make_aad(rec->aad_space, msg_pl->sg.size + prot->tail_size,
tls_ctx->tx.rec_seq, record_type, prot);
tls_fill_prepend(tls_ctx,
page_address(sg_page(&msg_en->sg.data[i])) +
msg_en->sg.data[i].offset,
msg_pl->sg.size + prot->tail_size,
record_type);
tls_ctx->pending_open_record_frags = false;
rc = tls_do_encryption(sk, tls_ctx, ctx, req,
msg_pl->sg.size + prot->tail_size, i);
if (rc < 0) {
if (rc != -EINPROGRESS) {
tls_err_abort(sk, -EBADMSG);
if (split) {
tls_ctx->pending_open_record_frags = true;
tls_merge_open_record(sk, rec, tmp, orig_end);
}
}
ctx->async_capable = 1;
return rc;
} else if (split) {
msg_pl = &tmp->msg_plaintext;
msg_en = &tmp->msg_encrypted;
sk_msg_trim(sk, msg_en, msg_pl->sg.size + prot->overhead_size);
tls_ctx->pending_open_record_frags = true;
ctx->open_rec = tmp;
}
return tls_tx_records(sk, flags);
}
static int bpf_exec_tx_verdict(struct sk_msg *msg, struct sock *sk,
bool full_record, u8 record_type,
ssize_t *copied, int flags)
{
struct tls_context *tls_ctx = tls_get_ctx(sk);
struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
struct sk_msg msg_redir = { };
struct sk_psock *psock;
struct sock *sk_redir;
struct tls_rec *rec;
bool enospc, policy, redir_ingress;
int err = 0, send;
u32 delta = 0;
policy = !(flags & MSG_SENDPAGE_NOPOLICY);
psock = sk_psock_get(sk);
if (!psock || !policy) {
err = tls_push_record(sk, flags, record_type);
if (err && err != -EINPROGRESS && sk->sk_err == EBADMSG) {
*copied -= sk_msg_free(sk, msg);
tls_free_open_rec(sk);
err = -sk->sk_err;
}
if (psock)
sk_psock_put(sk, psock);
return err;
}
more_data:
enospc = sk_msg_full(msg);
if (psock->eval == __SK_NONE) {
delta = msg->sg.size;
psock->eval = sk_psock_msg_verdict(sk, psock, msg);
delta -= msg->sg.size;
}
if (msg->cork_bytes && msg->cork_bytes > msg->sg.size &&
!enospc && !full_record) {
err = -ENOSPC;
goto out_err;
}
msg->cork_bytes = 0;
send = msg->sg.size;
if (msg->apply_bytes && msg->apply_bytes < send)
send = msg->apply_bytes;
switch (psock->eval) {
case __SK_PASS:
err = tls_push_record(sk, flags, record_type);
if (err && err != -EINPROGRESS && sk->sk_err == EBADMSG) {
*copied -= sk_msg_free(sk, msg);
tls_free_open_rec(sk);
err = -sk->sk_err;
goto out_err;
}
break;
case __SK_REDIRECT:
redir_ingress = psock->redir_ingress;
sk_redir = psock->sk_redir;
memcpy(&msg_redir, msg, sizeof(*msg));
if (msg->apply_bytes < send)
msg->apply_bytes = 0;
else
msg->apply_bytes -= send;
sk_msg_return_zero(sk, msg, send);
msg->sg.size -= send;
release_sock(sk);
err = tcp_bpf_sendmsg_redir(sk_redir, redir_ingress,
&msg_redir, send, flags);
lock_sock(sk);
if (err < 0) {
*copied -= sk_msg_free_nocharge(sk, &msg_redir);
msg->sg.size = 0;
}
if (msg->sg.size == 0)
tls_free_open_rec(sk);
break;
case __SK_DROP:
default:
sk_msg_free_partial(sk, msg, send);
if (msg->apply_bytes < send)
msg->apply_bytes = 0;
else
msg->apply_bytes -= send;
if (msg->sg.size == 0)
tls_free_open_rec(sk);
*copied -= (send + delta);
err = -EACCES;
}
if (likely(!err)) {
bool reset_eval = !ctx->open_rec;
rec = ctx->open_rec;
if (rec) {
msg = &rec->msg_plaintext;
if (!msg->apply_bytes)
reset_eval = true;
}
if (reset_eval) {
psock->eval = __SK_NONE;
if (psock->sk_redir) {
sock_put(psock->sk_redir);
psock->sk_redir = NULL;
}
}
if (rec)
goto more_data;
}
out_err:
sk_psock_put(sk, psock);
return err;
}
static int tls_sw_push_pending_record(struct sock *sk, int flags)
{
struct tls_context *tls_ctx = tls_get_ctx(sk);
struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
struct tls_rec *rec = ctx->open_rec;
struct sk_msg *msg_pl;
size_t copied;
if (!rec)
return 0;
msg_pl = &rec->msg_plaintext;
copied = msg_pl->sg.size;
if (!copied)
return 0;
return bpf_exec_tx_verdict(msg_pl, sk, true, TLS_RECORD_TYPE_DATA,
&copied, flags);
}
static int tls_sw_sendmsg_splice(struct sock *sk, struct msghdr *msg,
struct sk_msg *msg_pl, size_t try_to_copy,
ssize_t *copied)
{
struct page *page = NULL, **pages = &page;
do {
ssize_t part;
size_t off;
part = iov_iter_extract_pages(&msg->msg_iter, &pages,
try_to_copy, 1, 0, &off);
if (part <= 0)
return part ?: -EIO;
if (WARN_ON_ONCE(!sendpage_ok(page))) {
iov_iter_revert(&msg->msg_iter, part);
return -EIO;
}
sk_msg_page_add(msg_pl, page, part, off);
msg_pl->sg.copybreak = 0;
msg_pl->sg.curr = msg_pl->sg.end;
sk_mem_charge(sk, part);
*copied += part;
try_to_copy -= part;
} while (try_to_copy && !sk_msg_full(msg_pl));
return 0;
}
static int tls_sw_sendmsg_locked(struct sock *sk, struct msghdr *msg,
size_t size)
{
long timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
struct tls_context *tls_ctx = tls_get_ctx(sk);
struct tls_prot_info *prot = &tls_ctx->prot_info;
struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
bool async_capable = ctx->async_capable;
unsigned char record_type = TLS_RECORD_TYPE_DATA;
bool is_kvec = iov_iter_is_kvec(&msg->msg_iter);
bool eor = !(msg->msg_flags & MSG_MORE);
size_t try_to_copy;
ssize_t copied = 0;
struct sk_msg *msg_pl, *msg_en;
struct tls_rec *rec;
int required_size;
int num_async = 0;
bool full_record;
int record_room;
int num_zc = 0;
int orig_size;
int ret = 0;
if (!eor && (msg->msg_flags & MSG_EOR))
return -EINVAL;
if (unlikely(msg->msg_controllen)) {
ret = tls_process_cmsg(sk, msg, &record_type);
if (ret) {
if (ret == -EINPROGRESS)
num_async++;
else if (ret != -EAGAIN)
goto send_end;
}
}
while (msg_data_left(msg)) {
if (sk->sk_err) {
ret = -sk->sk_err;
goto send_end;
}
if (ctx->open_rec)
rec = ctx->open_rec;
else
rec = ctx->open_rec = tls_get_rec(sk);
if (!rec) {
ret = -ENOMEM;
goto send_end;
}
msg_pl = &rec->msg_plaintext;
msg_en = &rec->msg_encrypted;
orig_size = msg_pl->sg.size;
full_record = false;
try_to_copy = msg_data_left(msg);
record_room = TLS_MAX_PAYLOAD_SIZE - msg_pl->sg.size;
if (try_to_copy >= record_room) {
try_to_copy = record_room;
full_record = true;
}
required_size = msg_pl->sg.size + try_to_copy +
prot->overhead_size;
if (!sk_stream_memory_free(sk))
goto wait_for_sndbuf;
alloc_encrypted:
ret = tls_alloc_encrypted_msg(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 - msg_en->sg.size;
full_record = true;
}
if (try_to_copy && (msg->msg_flags & MSG_SPLICE_PAGES)) {
ret = tls_sw_sendmsg_splice(sk, msg, msg_pl,
try_to_copy, &copied);
if (ret < 0)
goto send_end;
tls_ctx->pending_open_record_frags = true;
if (sk_msg_full(msg_pl))
full_record = true;
if (full_record || eor)
goto copied;
continue;
}
if (!is_kvec && (full_record || eor) && !async_capable) {
u32 first = msg_pl->sg.end;
ret = sk_msg_zerocopy_from_iter(sk, &msg->msg_iter,
msg_pl, try_to_copy);
if (ret)
goto fallback_to_reg_send;
num_zc++;
copied += try_to_copy;
sk_msg_sg_copy_set(msg_pl, first);
ret = bpf_exec_tx_verdict(msg_pl, sk, full_record,
record_type, &copied,
msg->msg_flags);
if (ret) {
if (ret == -EINPROGRESS)
num_async++;
else if (ret == -ENOMEM)
goto wait_for_memory;
else if (ctx->open_rec && ret == -ENOSPC)
goto rollback_iter;
else if (ret != -EAGAIN)
goto send_end;
}
continue;
rollback_iter:
copied -= try_to_copy;
sk_msg_sg_copy_clear(msg_pl, first);
iov_iter_revert(&msg->msg_iter,
msg_pl->sg.size - orig_size);
fallback_to_reg_send:
sk_msg_trim(sk, msg_pl, orig_size);
}
required_size = msg_pl->sg.size + try_to_copy;
ret = tls_clone_plaintext_msg(sk, required_size);
if (ret) {
if (ret != -ENOSPC)
goto send_end;
/* 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 - msg_pl->sg.size;
full_record = true;
sk_msg_trim(sk, msg_en,
msg_pl->sg.size + prot->overhead_size);
}
if (try_to_copy) {
ret = sk_msg_memcopy_from_iter(sk, &msg->msg_iter,
msg_pl, try_to_copy);
if (ret < 0)
goto trim_sgl;
}
/* Open records defined only if successfully copied, otherwise
* we would trim the sg but not reset the open record frags.
*/
tls_ctx->pending_open_record_frags = true;
copied += try_to_copy;
copied:
if (full_record || eor) {
ret = bpf_exec_tx_verdict(msg_pl, sk, full_record,
record_type, &copied,
msg->msg_flags);
if (ret) {
if (ret == -EINPROGRESS)
num_async++;
else if (ret == -ENOMEM)
goto wait_for_memory;
else if (ret != -EAGAIN) {
if (ret == -ENOSPC)
ret = 0;
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:
if (ctx->open_rec)
tls_trim_both_msgs(sk, orig_size);
goto send_end;
}
if (ctx->open_rec && msg_en->sg.size < required_size)
goto alloc_encrypted;
}
if (!num_async) {
goto send_end;
} else if (num_zc || eor) {
int err;
/* Wait for pending encryptions to get completed */
err = tls_encrypt_async_wait(ctx);
if (err) {
ret = err;
copied = 0;
}
}
/* Transmit if any encryptions have completed */
if (test_and_clear_bit(BIT_TX_SCHEDULED, &ctx->tx_bitmask)) {
cancel_delayed_work(&ctx->tx_work.work);
tls_tx_records(sk, msg->msg_flags);
}
send_end:
ret = sk_stream_error(sk, msg->msg_flags, ret);
return copied > 0 ? copied : ret;
}
int tls_sw_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
{
struct tls_context *tls_ctx = tls_get_ctx(sk);
int ret;
if (msg->msg_flags & ~(MSG_MORE | MSG_DONTWAIT | MSG_NOSIGNAL |
MSG_CMSG_COMPAT | MSG_SPLICE_PAGES | MSG_EOR |
MSG_SENDPAGE_NOPOLICY))
return -EOPNOTSUPP;
ret = mutex_lock_interruptible(&tls_ctx->tx_lock);
if (ret)
return ret;
lock_sock(sk);
ret = tls_sw_sendmsg_locked(sk, msg, size);
release_sock(sk);
mutex_unlock(&tls_ctx->tx_lock);
return ret;
}
/*
* Handle unexpected EOF during splice without SPLICE_F_MORE set.
*/
void tls_sw_splice_eof(struct socket *sock)
{
struct sock *sk = sock->sk;
struct tls_context *tls_ctx = tls_get_ctx(sk);
struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
struct tls_rec *rec;
struct sk_msg *msg_pl;
ssize_t copied = 0;
bool retrying = false;
int ret = 0;
if (!ctx->open_rec)
return;
mutex_lock(&tls_ctx->tx_lock);
lock_sock(sk);
retry:
/* same checks as in tls_sw_push_pending_record() */
rec = ctx->open_rec;
if (!rec)
goto unlock;
msg_pl = &rec->msg_plaintext;
if (msg_pl->sg.size == 0)
goto unlock;
/* Check the BPF advisor and perform transmission. */
ret = bpf_exec_tx_verdict(msg_pl, sk, false, TLS_RECORD_TYPE_DATA,
&copied, 0);
switch (ret) {
case 0:
case -EAGAIN:
if (retrying)
goto unlock;
retrying = true;
goto retry;
case -EINPROGRESS:
break;
default:
goto unlock;
}
/* Wait for pending encryptions to get completed */
if (tls_encrypt_async_wait(ctx))
goto unlock;
/* Transmit if any encryptions have completed */
if (test_and_clear_bit(BIT_TX_SCHEDULED, &ctx->tx_bitmask)) {
cancel_delayed_work(&ctx->tx_work.work);
tls_tx_records(sk, 0);
}
unlock:
release_sock(sk);
mutex_unlock(&tls_ctx->tx_lock);
}
static int
tls_rx_rec_wait(struct sock *sk, struct sk_psock *psock, bool nonblock,
bool released)
{
struct tls_context *tls_ctx = tls_get_ctx(sk);
struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
DEFINE_WAIT_FUNC(wait, woken_wake_function);
int ret = 0;
long timeo;
timeo = sock_rcvtimeo(sk, nonblock);
while (!tls_strp_msg_ready(ctx)) {
if (!sk_psock_queue_empty(psock))
return 0;
if (sk->sk_err)
return sock_error(sk);
if (ret < 0)
return ret;
if (!skb_queue_empty(&sk->sk_receive_queue)) {
tls_strp_check_rcv(&ctx->strp);
if (tls_strp_msg_ready(ctx))
break;
}
if (sk->sk_shutdown & RCV_SHUTDOWN)
return 0;
if (sock_flag(sk, SOCK_DONE))
return 0;
if (!timeo)
return -EAGAIN;
released = true;
add_wait_queue(sk_sleep(sk), &wait);
sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
ret = sk_wait_event(sk, &timeo,
tls_strp_msg_ready(ctx) ||
!sk_psock_queue_empty(psock),
&wait);
sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
remove_wait_queue(sk_sleep(sk), &wait);
/* Handle signals */
if (signal_pending(current))
return sock_intr_errno(timeo);
}
tls_strp_msg_load(&ctx->strp, released);
return 1;
}
static int tls_setup_from_iter(struct iov_iter *from,
int length, int *pages_used,
struct scatterlist *to,
int to_max_pages)
{
int rc = 0, i = 0, num_elem = *pages_used, maxpages;
struct page *pages[MAX_SKB_FRAGS];
unsigned int size = 0;
ssize_t copied, use;
size_t offset;
while (length > 0) {
i = 0;
maxpages = to_max_pages - num_elem;
if (maxpages == 0) {
rc = -EFAULT;
goto out;
}
copied = iov_iter_get_pages2(from, pages,
length,
maxpages, &offset);
if (copied <= 0) {
rc = -EFAULT;
goto out;
}
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]);
/* We do not uncharge memory from this API */
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);
*pages_used = num_elem;
return rc;
}
static struct sk_buff *
tls_alloc_clrtxt_skb(struct sock *sk, struct sk_buff *skb,
unsigned int full_len)
{
struct strp_msg *clr_rxm;
struct sk_buff *clr_skb;
int err;
clr_skb = alloc_skb_with_frags(0, full_len, TLS_PAGE_ORDER,
&err, sk->sk_allocation);
if (!clr_skb)
return NULL;
skb_copy_header(clr_skb, skb);
clr_skb->len = full_len;
clr_skb->data_len = full_len;
clr_rxm = strp_msg(clr_skb);
clr_rxm->offset = 0;
return clr_skb;
}
/* Decrypt handlers
*
* tls_decrypt_sw() and tls_decrypt_device() are decrypt handlers.
* They must transform the darg in/out argument are as follows:
* | Input | Output
* -------------------------------------------------------------------
* zc | Zero-copy decrypt allowed | Zero-copy performed
* async | Async decrypt allowed | Async crypto used / in progress
* skb | * | Output skb
*
* If ZC decryption was performed darg.skb will point to the input skb.
*/
/* This function decrypts the input skb into either out_iov or in out_sg
* or in skb buffers itself. The input parameter 'darg->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 'darg->zc' is updated.
*/
static int tls_decrypt_sg(struct sock *sk, struct iov_iter *out_iov,
struct scatterlist *out_sg,
struct tls_decrypt_arg *darg)
{
struct tls_context *tls_ctx = tls_get_ctx(sk);
struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
struct tls_prot_info *prot = &tls_ctx->prot_info;
int n_sgin, n_sgout, aead_size, err, pages = 0;
struct sk_buff *skb = tls_strp_msg(ctx);
const struct strp_msg *rxm = strp_msg(skb);
const struct tls_msg *tlm = tls_msg(skb);
struct aead_request *aead_req;
struct scatterlist *sgin = NULL;
struct scatterlist *sgout = NULL;
const int data_len = rxm->full_len - prot->overhead_size;
int tail_pages = !!prot->tail_size;
struct tls_decrypt_ctx *dctx;
struct sk_buff *clear_skb;
int iv_offset = 0;
u8 *mem;
n_sgin = skb_nsg(skb, rxm->offset + prot->prepend_size,
rxm->full_len - prot->prepend_size);
if (n_sgin < 1)
return n_sgin ?: -EBADMSG;
if (darg->zc && (out_iov || out_sg)) {
clear_skb = NULL;
if (out_iov)
n_sgout = 1 + tail_pages +
iov_iter_npages_cap(out_iov, INT_MAX, data_len);
else
n_sgout = sg_nents(out_sg);
} else {
darg->zc = false;
clear_skb = tls_alloc_clrtxt_skb(sk, skb, rxm->full_len);
if (!clear_skb)
return -ENOMEM;
n_sgout = 1 + skb_shinfo(clear_skb)->nr_frags;
}
/* Increment to accommodate AAD */
n_sgin = n_sgin + 1;
/* Allocate a single block of memory which contains
* aead_req || tls_decrypt_ctx.
* Both structs are variable length.
*/
aead_size = sizeof(*aead_req) + crypto_aead_reqsize(ctx->aead_recv);
aead_size = ALIGN(aead_size, __alignof__(*dctx));
mem = kmalloc(aead_size + struct_size(dctx, sg, size_add(n_sgin, n_sgout)),
sk->sk_allocation);
if (!mem) {
err = -ENOMEM;
goto exit_free_skb;
}
/* Segment the allocated memory */
aead_req = (struct aead_request *)mem;
dctx = (struct tls_decrypt_ctx *)(mem + aead_size);
dctx->sk = sk;
sgin = &dctx->sg[0];
sgout = &dctx->sg[n_sgin];
/* For CCM based ciphers, first byte of nonce+iv is a constant */
switch (prot->cipher_type) {
case TLS_CIPHER_AES_CCM_128:
dctx->iv[0] = TLS_AES_CCM_IV_B0_BYTE;
iv_offset = 1;
break;
case TLS_CIPHER_SM4_CCM:
dctx->iv[0] = TLS_SM4_CCM_IV_B0_BYTE;
iv_offset = 1;
break;
}
/* Prepare IV */
if (prot->version == TLS_1_3_VERSION ||
prot->cipher_type == TLS_CIPHER_CHACHA20_POLY1305) {
memcpy(&dctx->iv[iv_offset], tls_ctx->rx.iv,
prot->iv_size + prot->salt_size);
} else {
err = skb_copy_bits(skb, rxm->offset + TLS_HEADER_SIZE,
&dctx->iv[iv_offset] + prot->salt_size,
prot->iv_size);
if (err < 0)
goto exit_free;
memcpy(&dctx->iv[iv_offset], tls_ctx->rx.iv, prot->salt_size);
}
tls_xor_iv_with_seq(prot, &dctx->iv[iv_offset], tls_ctx->rx.rec_seq);
/* Prepare AAD */
tls_make_aad(dctx->aad, rxm->full_len - prot->overhead_size +
prot->tail_size,
tls_ctx->rx.rec_seq, tlm->control, prot);
/* Prepare sgin */
sg_init_table(sgin, n_sgin);
sg_set_buf(&sgin[0], dctx->aad, prot->aad_size);
err = skb_to_sgvec(skb, &sgin[1],
rxm->offset + prot->prepend_size,
rxm->full_len - prot->prepend_size);
if (err < 0)
goto exit_free;
if (clear_skb) {
sg_init_table(sgout, n_sgout);
sg_set_buf(&sgout[0], dctx->aad, prot->aad_size);
err = skb_to_sgvec(clear_skb, &sgout[1], prot->prepend_size,
data_len + prot->tail_size);
if (err < 0)
goto exit_free;
} else if (out_iov) {
sg_init_table(sgout, n_sgout);
sg_set_buf(&sgout[0], dctx->aad, prot->aad_size);
err = tls_setup_from_iter(out_iov, data_len, &pages, &sgout[1],
(n_sgout - 1 - tail_pages));
if (err < 0)
goto exit_free_pages;
if (prot->tail_size) {
sg_unmark_end(&sgout[pages]);
sg_set_buf(&sgout[pages + 1], &dctx->tail,
prot->tail_size);
sg_mark_end(&sgout[pages + 1]);
}
} else if (out_sg) {
memcpy(sgout, out_sg, n_sgout * sizeof(*sgout));
}
dctx->free_sgout = !!pages;
/* Prepare and submit AEAD request */
err = tls_do_decryption(sk, sgin, sgout, dctx->iv,
data_len + prot->tail_size, aead_req, darg);
if (err) {
if (darg->async_done)
goto exit_free_skb;
goto exit_free_pages;
}
darg->skb = clear_skb ?: tls_strp_msg(ctx);
clear_skb = NULL;
if (unlikely(darg->async)) {
err = tls_strp_msg_hold(&ctx->strp, &ctx->async_hold);
if (err)
__skb_queue_tail(&ctx->async_hold, darg->skb);
return err;
}
if (unlikely(darg->async_done))
return 0;
if (prot->tail_size)
darg->tail = dctx->tail;
exit_free_pages:
/* Release the pages in case iov was mapped to pages */
for (; pages > 0; pages--)
put_page(sg_page(&sgout[pages]));
exit_free:
kfree(mem);
exit_free_skb:
consume_skb(clear_skb);
return err;
}
static int
tls_decrypt_sw(struct sock *sk, struct tls_context *tls_ctx,
struct msghdr *msg, struct tls_decrypt_arg *darg)
{
struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
struct tls_prot_info *prot = &tls_ctx->prot_info;
struct strp_msg *rxm;
int pad, err;
err = tls_decrypt_sg(sk, &msg->msg_iter, NULL, darg);
if (err < 0) {
if (err == -EBADMSG)
TLS_INC_STATS(sock_net(sk), LINUX_MIB_TLSDECRYPTERROR);
return err;
}
/* keep going even for ->async, the code below is TLS 1.3 */
/* If opportunistic TLS 1.3 ZC failed retry without ZC */
if (unlikely(darg->zc && prot->version == TLS_1_3_VERSION &&
darg->tail != TLS_RECORD_TYPE_DATA)) {
darg->zc = false;
if (!darg->tail)
TLS_INC_STATS(sock_net(sk), LINUX_MIB_TLSRXNOPADVIOL);
TLS_INC_STATS(sock_net(sk), LINUX_MIB_TLSDECRYPTRETRY);
return tls_decrypt_sw(sk, tls_ctx, msg, darg);
}
pad = tls_padding_length(prot, darg->skb, darg);
if (pad < 0) {
if (darg->skb != tls_strp_msg(ctx))
consume_skb(darg->skb);
return pad;
}
rxm = strp_msg(darg->skb);
rxm->full_len -= pad;
return 0;
}
static int
tls_decrypt_device(struct sock *sk, struct msghdr *msg,
struct tls_context *tls_ctx, struct tls_decrypt_arg *darg)
{
struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
struct tls_prot_info *prot = &tls_ctx->prot_info;
struct strp_msg *rxm;
int pad, err;
if (tls_ctx->rx_conf != TLS_HW)
return 0;
err = tls_device_decrypted(sk, tls_ctx);
if (err <= 0)
return err;
pad = tls_padding_length(prot, tls_strp_msg(ctx), darg);
if (pad < 0)
return pad;
darg->async = false;
darg->skb = tls_strp_msg(ctx);
/* ->zc downgrade check, in case TLS 1.3 gets here */
darg->zc &= !(prot->version == TLS_1_3_VERSION &&
tls_msg(darg->skb)->control != TLS_RECORD_TYPE_DATA);
rxm = strp_msg(darg->skb);
rxm->full_len -= pad;
if (!darg->zc) {
/* Non-ZC case needs a real skb */
darg->skb = tls_strp_msg_detach(ctx);
if (!darg->skb)
return -ENOMEM;
} else {
unsigned int off, len;
/* In ZC case nobody cares about the output skb.
* Just copy the data here. Note the skb is not fully trimmed.
*/
off = rxm->offset + prot->prepend_size;
len = rxm->full_len - prot->overhead_size;
err = skb_copy_datagram_msg(darg->skb, off, msg, len);
if (err)
return err;
}
return 1;
}
static int tls_rx_one_record(struct sock *sk, struct msghdr *msg,
struct tls_decrypt_arg *darg)
{
struct tls_context *tls_ctx = tls_get_ctx(sk);
struct tls_prot_info *prot = &tls_ctx->prot_info;
struct strp_msg *rxm;
int err;
err = tls_decrypt_device(sk, msg, tls_ctx, darg);
if (!err)
err = tls_decrypt_sw(sk, tls_ctx, msg, darg);
if (err < 0)
return err;
rxm = strp_msg(darg->skb);
rxm->offset += prot->prepend_size;
rxm->full_len -= prot->overhead_size;
tls_advance_record_sn(sk, prot, &tls_ctx->rx);
return 0;
}
int decrypt_skb(struct sock *sk, struct scatterlist *sgout)
{
struct tls_decrypt_arg darg = { .zc = true, };
return tls_decrypt_sg(sk, NULL, sgout, &darg);
}
static int tls_record_content_type(struct msghdr *msg, struct tls_msg *tlm,
u8 *control)
{
int err;
if (!*control) {
*control = tlm->control;
if (!*control)
return -EBADMSG;
err = put_cmsg(msg, SOL_TLS, TLS_GET_RECORD_TYPE,
sizeof(*control), control);
if (*control != TLS_RECORD_TYPE_DATA) {
if (err || msg->msg_flags & MSG_CTRUNC)
return -EIO;
}
} else if (*control != tlm->control) {
return 0;
}
return 1;
}
static void tls_rx_rec_done(struct tls_sw_context_rx *ctx)
{
tls_strp_msg_done(&ctx->strp);
}
/* This function traverses the rx_list in tls receive context to copies the
* decrypted records into the buffer provided by caller zero copy is not
* true. Further, the records are removed from the rx_list if it is not a peek
* case and the record has been consumed completely.
*/
static int process_rx_list(struct tls_sw_context_rx *ctx,
struct msghdr *msg,
u8 *control,
size_t skip,
size_t len,
bool is_peek,
bool *more)
{
struct sk_buff *skb = skb_peek(&ctx->rx_list);
struct tls_msg *tlm;
ssize_t copied = 0;
int err;
while (skip && skb) {
struct strp_msg *rxm = strp_msg(skb);
tlm = tls_msg(skb);
err = tls_record_content_type(msg, tlm, control);
if (err <= 0)
goto more;
if (skip < rxm->full_len)
break;
skip = skip - rxm->full_len;
skb = skb_peek_next(skb, &ctx->rx_list);
}
while (len && skb) {
struct sk_buff *next_skb;
struct strp_msg *rxm = strp_msg(skb);
int chunk = min_t(unsigned int, rxm->full_len - skip, len);
tlm = tls_msg(skb);
err = tls_record_content_type(msg, tlm, control);
if (err <= 0)
goto more;
err = skb_copy_datagram_msg(skb, rxm->offset + skip,
msg, chunk);
if (err < 0)
goto more;
len = len - chunk;
copied = copied + chunk;
/* Consume the data from record if it is non-peek case*/
if (!is_peek) {
rxm->offset = rxm->offset + chunk;
rxm->full_len = rxm->full_len - chunk;
/* Return if there is unconsumed data in the record */
if (rxm->full_len - skip)
break;
}
/* The remaining skip-bytes must lie in 1st record in rx_list.
* So from the 2nd record, 'skip' should be 0.
*/
skip = 0;
if (msg)
msg->msg_flags |= MSG_EOR;
next_skb = skb_peek_next(skb, &ctx->rx_list);
if (!is_peek) {
__skb_unlink(skb, &ctx->rx_list);
consume_skb(skb);
}
skb = next_skb;
}
err = 0;
out:
return copied ? : err;
more:
if (more)
*more = true;
goto out;
}
static bool
tls_read_flush_backlog(struct sock *sk, struct tls_prot_info *prot,
size_t len_left, size_t decrypted, ssize_t done,
size_t *flushed_at)
{
size_t max_rec;
if (len_left <= decrypted)
return false;
max_rec = prot->overhead_size - prot->tail_size + TLS_MAX_PAYLOAD_SIZE;
if (done - *flushed_at < SZ_128K && tcp_inq(sk) > max_rec)
return false;
*flushed_at = done;
return sk_flush_backlog(sk);
}
static int tls_rx_reader_acquire(struct sock *sk, struct tls_sw_context_rx *ctx,
bool nonblock)
{
long timeo;
int ret;
timeo = sock_rcvtimeo(sk, nonblock);
while (unlikely(ctx->reader_present)) {
DEFINE_WAIT_FUNC(wait, woken_wake_function);
ctx->reader_contended = 1;
add_wait_queue(&ctx->wq, &wait);
ret = sk_wait_event(sk, &timeo,
!READ_ONCE(ctx->reader_present), &wait);
remove_wait_queue(&ctx->wq, &wait);
if (timeo <= 0)
return -EAGAIN;
if (signal_pending(current))
return sock_intr_errno(timeo);
if (ret < 0)
return ret;
}
WRITE_ONCE(ctx->reader_present, 1);
return 0;
}
static int tls_rx_reader_lock(struct sock *sk, struct tls_sw_context_rx *ctx,
bool nonblock)
{
int err;
lock_sock(sk);
err = tls_rx_reader_acquire(sk, ctx, nonblock);
if (err)
release_sock(sk);
return err;
}
static void tls_rx_reader_release(struct sock *sk, struct tls_sw_context_rx *ctx)
{
if (unlikely(ctx->reader_contended)) {
if (wq_has_sleeper(&ctx->wq))
wake_up(&ctx->wq);
else
ctx->reader_contended = 0;
WARN_ON_ONCE(!ctx->reader_present);
}
WRITE_ONCE(ctx->reader_present, 0);
}
static void tls_rx_reader_unlock(struct sock *sk, struct tls_sw_context_rx *ctx)
{
tls_rx_reader_release(sk, ctx);
release_sock(sk);
}
int tls_sw_recvmsg(struct sock *sk,
struct msghdr *msg,
size_t len,
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);
struct tls_prot_info *prot = &tls_ctx->prot_info;
ssize_t decrypted = 0, async_copy_bytes = 0;
struct sk_psock *psock;
unsigned char control = 0;
size_t flushed_at = 0;
struct strp_msg *rxm;
struct tls_msg *tlm;
ssize_t copied = 0;
ssize_t peeked = 0;
bool async = false;
int target, err;
bool is_kvec = iov_iter_is_kvec(&msg->msg_iter);
bool is_peek = flags & MSG_PEEK;
bool rx_more = false;
bool released = true;
bool bpf_strp_enabled;
bool zc_capable;
if (unlikely(flags & MSG_ERRQUEUE))
return sock_recv_errqueue(sk, msg, len, SOL_IP, IP_RECVERR);
err = tls_rx_reader_lock(sk, ctx, flags & MSG_DONTWAIT);
if (err < 0)
return err;
psock = sk_psock_get(sk);
bpf_strp_enabled = sk_psock_strp_enabled(psock);
/* If crypto failed the connection is broken */
err = ctx->async_wait.err;
if (err)
goto end;
/* Process pending decrypted records. It must be non-zero-copy */
err = process_rx_list(ctx, msg, &control, 0, len, is_peek, &rx_more);
if (err < 0)
goto end;
copied = err;
if (len <= copied || (copied && control != TLS_RECORD_TYPE_DATA) || rx_more)
goto end;
target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
len = len - copied;
zc_capable = !bpf_strp_enabled && !is_kvec && !is_peek &&
ctx->zc_capable;
decrypted = 0;
while (len && (decrypted + copied < target || tls_strp_msg_ready(ctx))) {
struct tls_decrypt_arg darg;
int to_decrypt, chunk;
err = tls_rx_rec_wait(sk, psock, flags & MSG_DONTWAIT,
released);
if (err <= 0) {
if (psock) {
chunk = sk_msg_recvmsg(sk, psock, msg, len,
flags);
if (chunk > 0) {
decrypted += chunk;
len -= chunk;
continue;
}
}
goto recv_end;
}
memset(&darg.inargs, 0, sizeof(darg.inargs));
rxm = strp_msg(tls_strp_msg(ctx));
tlm = tls_msg(tls_strp_msg(ctx));
to_decrypt = rxm->full_len - prot->overhead_size;
if (zc_capable && to_decrypt <= len &&
tlm->control == TLS_RECORD_TYPE_DATA)
darg.zc = true;
/* Do not use async mode if record is non-data */
if (tlm->control == TLS_RECORD_TYPE_DATA && !bpf_strp_enabled)
darg.async = ctx->async_capable;
else
darg.async = false;
err = tls_rx_one_record(sk, msg, &darg);
if (err < 0) {
tls_err_abort(sk, -EBADMSG);
goto recv_end;
}
async |= darg.async;
/* If the type of records being processed is not known yet,
* set it to record type just dequeued. If it is already known,
* but does not match the record type just dequeued, go to end.
* We always get record type here since for tls1.2, record type
* is known just after record is dequeued from stream parser.
* For tls1.3, we disable async.
*/
err = tls_record_content_type(msg, tls_msg(darg.skb), &control);
if (err <= 0) {
DEBUG_NET_WARN_ON_ONCE(darg.zc);
tls_rx_rec_done(ctx);
put_on_rx_list_err:
__skb_queue_tail(&ctx->rx_list, darg.skb);
goto recv_end;
}
/* periodically flush backlog, and feed strparser */
released = tls_read_flush_backlog(sk, prot, len, to_decrypt,
decrypted + copied,
&flushed_at);
/* TLS 1.3 may have updated the length by more than overhead */
rxm = strp_msg(darg.skb);
chunk = rxm->full_len;
tls_rx_rec_done(ctx);
if (!darg.zc) {
bool partially_consumed = chunk > len;
struct sk_buff *skb = darg.skb;
DEBUG_NET_WARN_ON_ONCE(darg.skb == ctx->strp.anchor);
if (async) {
/* TLS 1.2-only, to_decrypt must be text len */
chunk = min_t(int, to_decrypt, len);
async_copy_bytes += chunk;
put_on_rx_list:
decrypted += chunk;
len -= chunk;
__skb_queue_tail(&ctx->rx_list, skb);
if (unlikely(control != TLS_RECORD_TYPE_DATA))
break;
continue;
}
if (bpf_strp_enabled) {
released = true;
err = sk_psock_tls_strp_read(psock, skb);
if (err != __SK_PASS) {
rxm->offset = rxm->offset + rxm->full_len;
rxm->full_len = 0;
if (err == __SK_DROP)
consume_skb(skb);
continue;
}
}
if (partially_consumed)
chunk = len;
err = skb_copy_datagram_msg(skb, rxm->offset,
msg, chunk);
if (err < 0)
goto put_on_rx_list_err;
if (is_peek) {
peeked += chunk;
goto put_on_rx_list;
}
if (partially_consumed) {
rxm->offset += chunk;
rxm->full_len -= chunk;
goto put_on_rx_list;
}
consume_skb(skb);
}
decrypted += chunk;
len -= 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)
break;
}
recv_end:
if (async) {
int ret;
/* Wait for all previously submitted records to be decrypted */
ret = tls_decrypt_async_wait(ctx);
__skb_queue_purge(&ctx->async_hold);
if (ret) {
if (err >= 0 || err == -EINPROGRESS)
err = ret;
goto end;
}
/* Drain records from the rx_list & copy if required */
if (is_peek)
err = process_rx_list(ctx, msg, &control, copied + peeked,
decrypted - peeked, is_peek, NULL);
else
err = process_rx_list(ctx, msg, &control, 0,
async_copy_bytes, is_peek, NULL);
/* we could have copied less than we wanted, and possibly nothing */
decrypted += max(err, 0) - async_copy_bytes;
}
copied += decrypted;
end:
tls_rx_reader_unlock(sk, ctx);
if (psock)
sk_psock_put(sk, psock);
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 tls_msg *tlm;
struct sk_buff *skb;
ssize_t copied = 0;
int chunk;
int err;
err = tls_rx_reader_lock(sk, ctx, flags & SPLICE_F_NONBLOCK);
if (err < 0)
return err;
if (!skb_queue_empty(&ctx->rx_list)) {
skb = __skb_dequeue(&ctx->rx_list);
} else {
struct tls_decrypt_arg darg;
err = tls_rx_rec_wait(sk, NULL, flags & SPLICE_F_NONBLOCK,
true);
if (err <= 0)
goto splice_read_end;
memset(&darg.inargs, 0, sizeof(darg.inargs));
err = tls_rx_one_record(sk, NULL, &darg);
if (err < 0) {
tls_err_abort(sk, -EBADMSG);
goto splice_read_end;
}
tls_rx_rec_done(ctx);
skb = darg.skb;
}
rxm = strp_msg(skb);
tlm = tls_msg(skb);
/* splice does not support reading control messages */
if (tlm->control != TLS_RECORD_TYPE_DATA) {
err = -EINVAL;
goto splice_requeue;
}
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_requeue;
if (chunk < rxm->full_len) {
rxm->offset += len;
rxm->full_len -= len;
goto splice_requeue;
}
consume_skb(skb);
splice_read_end:
tls_rx_reader_unlock(sk, ctx);
return copied ? : err;
splice_requeue:
__skb_queue_head(&ctx->rx_list, skb);
goto splice_read_end;
}
int tls_sw_read_sock(struct sock *sk, read_descriptor_t *desc,
sk_read_actor_t read_actor)
{
struct tls_context *tls_ctx = tls_get_ctx(sk);
struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
struct tls_prot_info *prot = &tls_ctx->prot_info;
struct strp_msg *rxm = NULL;
struct sk_buff *skb = NULL;
struct sk_psock *psock;
size_t flushed_at = 0;
bool released = true;
struct tls_msg *tlm;
ssize_t copied = 0;
ssize_t decrypted;
int err, used;
psock = sk_psock_get(sk);
if (psock) {
sk_psock_put(sk, psock);
return -EINVAL;
}
err = tls_rx_reader_acquire(sk, ctx, true);
if (err < 0)
return err;
/* If crypto failed the connection is broken */
err = ctx->async_wait.err;
if (err)
goto read_sock_end;
decrypted = 0;
do {
if (!skb_queue_empty(&ctx->rx_list)) {
skb = __skb_dequeue(&ctx->rx_list);
rxm = strp_msg(skb);
tlm = tls_msg(skb);
} else {
struct tls_decrypt_arg darg;
err = tls_rx_rec_wait(sk, NULL, true, released);
if (err <= 0)
goto read_sock_end;
memset(&darg.inargs, 0, sizeof(darg.inargs));
err = tls_rx_one_record(sk, NULL, &darg);
if (err < 0) {
tls_err_abort(sk, -EBADMSG);
goto read_sock_end;
}
released = tls_read_flush_backlog(sk, prot, INT_MAX,
0, decrypted,
&flushed_at);
skb = darg.skb;
rxm = strp_msg(skb);
tlm = tls_msg(skb);
decrypted += rxm->full_len;
tls_rx_rec_done(ctx);
}
/* read_sock does not support reading control messages */
if (tlm->control != TLS_RECORD_TYPE_DATA) {
err = -EINVAL;
goto read_sock_requeue;
}
used = read_actor(desc, skb, rxm->offset, rxm->full_len);
if (used <= 0) {
if (!copied)
err = used;
goto read_sock_requeue;
}
copied += used;
if (used < rxm->full_len) {
rxm->offset += used;
rxm->full_len -= used;
if (!desc->count)
goto read_sock_requeue;
} else {
consume_skb(skb);
if (!desc->count)
skb = NULL;
}
} while (skb);
read_sock_end:
tls_rx_reader_release(sk, ctx);
return copied ? : err;
read_sock_requeue:
__skb_queue_head(&ctx->rx_list, skb);
goto read_sock_end;
}
bool tls_sw_sock_is_readable(struct sock *sk)
{
struct tls_context *tls_ctx = tls_get_ctx(sk);
struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
bool ingress_empty = true;
struct sk_psock *psock;
rcu_read_lock();
psock = sk_psock(sk);
if (psock)
ingress_empty = list_empty(&psock->ingress_msg);
rcu_read_unlock();
return !ingress_empty || tls_strp_msg_ready(ctx) ||
!skb_queue_empty(&ctx->rx_list);
}
int tls_rx_msg_size(struct tls_strparser *strp, struct sk_buff *skb)
{
struct tls_context *tls_ctx = tls_get_ctx(strp->sk);
struct tls_prot_info *prot = &tls_ctx->prot_info;
char header[TLS_HEADER_SIZE + TLS_MAX_IV_SIZE];
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 (strp->stm.offset + prot->prepend_size > skb->len)
return 0;
/* Sanity-check size of on-stack buffer. */
if (WARN_ON(prot->prepend_size > sizeof(header))) {
ret = -EINVAL;
goto read_failure;
}
/* Linearize header to local buffer */
ret = skb_copy_bits(skb, strp->stm.offset, header, prot->prepend_size);
if (ret < 0)
goto read_failure;
strp->mark = header[0];
data_len = ((header[4] & 0xFF) | (header[3] << 8));
cipher_overhead = prot->tag_size;
if (prot->version != TLS_1_3_VERSION &&
prot->cipher_type != TLS_CIPHER_CHACHA20_POLY1305)
cipher_overhead += prot->iv_size;
if (data_len > TLS_MAX_PAYLOAD_SIZE + cipher_overhead +
prot->tail_size) {
ret = -EMSGSIZE;
goto read_failure;
}
if (data_len < cipher_overhead) {
ret = -EBADMSG;
goto read_failure;
}
/* Note that both TLS1.3 and TLS1.2 use TLS_1_2 version here */
if (header[1] != TLS_1_2_VERSION_MINOR ||
header[2] != TLS_1_2_VERSION_MAJOR) {
ret = -EINVAL;
goto read_failure;
}
tls_device_rx_resync_new_rec(strp->sk, data_len + TLS_HEADER_SIZE,
TCP_SKB_CB(skb)->seq + strp->stm.offset);
return data_len + TLS_HEADER_SIZE;
read_failure:
tls_err_abort(strp->sk, ret);
return ret;
}
void tls_rx_msg_ready(struct tls_strparser *strp)
{
struct tls_sw_context_rx *ctx;
ctx = container_of(strp, struct tls_sw_context_rx, 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);
struct sk_psock *psock;
gfp_t alloc_save;
trace_sk_data_ready(sk);
alloc_save = sk->sk_allocation;
sk->sk_allocation = GFP_ATOMIC;
tls_strp_data_ready(&ctx->strp);
sk->sk_allocation = alloc_save;
psock = sk_psock_get(sk);
if (psock) {
if (!list_empty(&psock->ingress_msg))
ctx->saved_data_ready(sk);
sk_psock_put(sk, psock);
}
}
void tls_sw_cancel_work_tx(struct tls_context *tls_ctx)
{
struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
set_bit(BIT_TX_CLOSING, &ctx->tx_bitmask);
set_bit(BIT_TX_SCHEDULED, &ctx->tx_bitmask);
cancel_delayed_work_sync(&ctx->tx_work.work);
}
void tls_sw_release_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);
struct tls_rec *rec, *tmp;
/* Wait for any pending async encryptions to complete */
tls_encrypt_async_wait(ctx);
tls_tx_records(sk, -1);
/* Free up un-sent records in tx_list. First, free
* the partially sent record if any at head of tx_list.
*/
if (tls_ctx->partially_sent_record) {
tls_free_partial_record(sk, tls_ctx);
rec = list_first_entry(&ctx->tx_list,
struct tls_rec, list);
list_del(&rec->list);
sk_msg_free(sk, &rec->msg_plaintext);
kfree(rec);
}
list_for_each_entry_safe(rec, tmp, &ctx->tx_list, list) {
list_del(&rec->list);
sk_msg_free(sk, &rec->msg_encrypted);
sk_msg_free(sk, &rec->msg_plaintext);
kfree(rec);
}
crypto_free_aead(ctx->aead_send);
tls_free_open_rec(sk);
}
void tls_sw_free_ctx_tx(struct tls_context *tls_ctx)
{
struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
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) {
__skb_queue_purge(&ctx->rx_list);
crypto_free_aead(ctx->aead_recv);
tls_strp_stop(&ctx->strp);
/* If tls_sw_strparser_arm() was not called (cleanup paths)
* we still want to tls_strp_stop(), but sk->sk_data_ready was
* never swapped.
*/
if (ctx->saved_data_ready) {
write_lock_bh(&sk->sk_callback_lock);
sk->sk_data_ready = ctx->saved_data_ready;
write_unlock_bh(&sk->sk_callback_lock);
}
}
}
void tls_sw_strparser_done(struct tls_context *tls_ctx)
{
struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
tls_strp_done(&ctx->strp);
}
void tls_sw_free_ctx_rx(struct tls_context *tls_ctx)
{
struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
kfree(ctx);
}
void tls_sw_free_resources_rx(struct sock *sk)
{
struct tls_context *tls_ctx = tls_get_ctx(sk);
tls_sw_release_resources_rx(sk);
tls_sw_free_ctx_rx(tls_ctx);
}
/* The work handler to transmitt the encrypted records in tx_list */
static void tx_work_handler(struct work_struct *work)
{
struct delayed_work *delayed_work = to_delayed_work(work);
struct tx_work *tx_work = container_of(delayed_work,
struct tx_work, work);
struct sock *sk = tx_work->sk;
struct tls_context *tls_ctx = tls_get_ctx(sk);
struct tls_sw_context_tx *ctx;
if (unlikely(!tls_ctx))
return;
ctx = tls_sw_ctx_tx(tls_ctx);
if (test_bit(BIT_TX_CLOSING, &ctx->tx_bitmask))
return;
if (!test_and_clear_bit(BIT_TX_SCHEDULED, &ctx->tx_bitmask))
return;
if (mutex_trylock(&tls_ctx->tx_lock)) {
lock_sock(sk);
tls_tx_records(sk, -1);
release_sock(sk);
mutex_unlock(&tls_ctx->tx_lock);
} else if (!test_and_set_bit(BIT_TX_SCHEDULED, &ctx->tx_bitmask)) {
/* Someone is holding the tx_lock, they will likely run Tx
* and cancel the work on their way out of the lock section.
* Schedule a long delay just in case.
*/
schedule_delayed_work(&ctx->tx_work.work, msecs_to_jiffies(10));
}
}
static bool tls_is_tx_ready(struct tls_sw_context_tx *ctx)
{
struct tls_rec *rec;
rec = list_first_entry_or_null(&ctx->tx_list, struct tls_rec, list);
if (!rec)
return false;
return READ_ONCE(rec->tx_ready);
}
void tls_sw_write_space(struct sock *sk, struct tls_context *ctx)
{
struct tls_sw_context_tx *tx_ctx = tls_sw_ctx_tx(ctx);
/* Schedule the transmission if tx list is ready */
if (tls_is_tx_ready(tx_ctx) &&
!test_and_set_bit(BIT_TX_SCHEDULED, &tx_ctx->tx_bitmask))
schedule_delayed_work(&tx_ctx->tx_work.work, 0);
}
void tls_sw_strparser_arm(struct sock *sk, struct tls_context *tls_ctx)
{
struct tls_sw_context_rx *rx_ctx = tls_sw_ctx_rx(tls_ctx);
write_lock_bh(&sk->sk_callback_lock);
rx_ctx->saved_data_ready = sk->sk_data_ready;
sk->sk_data_ready = tls_data_ready;
write_unlock_bh(&sk->sk_callback_lock);
}
void tls_update_rx_zc_capable(struct tls_context *tls_ctx)
{
struct tls_sw_context_rx *rx_ctx = tls_sw_ctx_rx(tls_ctx);
rx_ctx->zc_capable = tls_ctx->rx_no_pad ||
tls_ctx->prot_info.version != TLS_1_3_VERSION;
}
static struct tls_sw_context_tx *init_ctx_tx(struct tls_context *ctx, struct sock *sk)
{
struct tls_sw_context_tx *sw_ctx_tx;
if (!ctx->priv_ctx_tx) {
sw_ctx_tx = kzalloc(sizeof(*sw_ctx_tx), GFP_KERNEL);
if (!sw_ctx_tx)
return NULL;
} else {
sw_ctx_tx = ctx->priv_ctx_tx;
}
crypto_init_wait(&sw_ctx_tx->async_wait);
atomic_set(&sw_ctx_tx->encrypt_pending, 1);
INIT_LIST_HEAD(&sw_ctx_tx->tx_list);
INIT_DELAYED_WORK(&sw_ctx_tx->tx_work.work, tx_work_handler);
sw_ctx_tx->tx_work.sk = sk;
return sw_ctx_tx;
}
static struct tls_sw_context_rx *init_ctx_rx(struct tls_context *ctx)
{
struct tls_sw_context_rx *sw_ctx_rx;
if (!ctx->priv_ctx_rx) {
sw_ctx_rx = kzalloc(sizeof(*sw_ctx_rx), GFP_KERNEL);
if (!sw_ctx_rx)
return NULL;
} else {
sw_ctx_rx = ctx->priv_ctx_rx;
}
crypto_init_wait(&sw_ctx_rx->async_wait);
atomic_set(&sw_ctx_rx->decrypt_pending, 1);
init_waitqueue_head(&sw_ctx_rx->wq);
skb_queue_head_init(&sw_ctx_rx->rx_list);
skb_queue_head_init(&sw_ctx_rx->async_hold);
return sw_ctx_rx;
}
int init_prot_info(struct tls_prot_info *prot,
const struct tls_crypto_info *crypto_info,
const struct tls_cipher_desc *cipher_desc)
{
u16 nonce_size = cipher_desc->nonce;
if (crypto_info->version == TLS_1_3_VERSION) {
nonce_size = 0;
prot->aad_size = TLS_HEADER_SIZE;
prot->tail_size = 1;
} else {
prot->aad_size = TLS_AAD_SPACE_SIZE;
prot->tail_size = 0;
}
/* Sanity-check the sizes for stack allocations. */
if (nonce_size > TLS_MAX_IV_SIZE || prot->aad_size > TLS_MAX_AAD_SIZE)
return -EINVAL;
prot->version = crypto_info->version;
prot->cipher_type = crypto_info->cipher_type;
prot->prepend_size = TLS_HEADER_SIZE + nonce_size;
prot->tag_size = cipher_desc->tag;
prot->overhead_size = prot->prepend_size + prot->tag_size + prot->tail_size;
prot->iv_size = cipher_desc->iv;
prot->salt_size = cipher_desc->salt;
prot->rec_seq_size = cipher_desc->rec_seq;
return 0;
}
int tls_set_sw_offload(struct sock *sk, int tx)
{
struct tls_sw_context_tx *sw_ctx_tx = NULL;
struct tls_sw_context_rx *sw_ctx_rx = NULL;
const struct tls_cipher_desc *cipher_desc;
struct tls_crypto_info *crypto_info;
char *iv, *rec_seq, *key, *salt;
struct cipher_context *cctx;
struct tls_prot_info *prot;
struct crypto_aead **aead;
struct tls_context *ctx;
struct crypto_tfm *tfm;
int rc = 0;
ctx = tls_get_ctx(sk);
prot = &ctx->prot_info;
if (tx) {
ctx->priv_ctx_tx = init_ctx_tx(ctx, sk);
if (!ctx->priv_ctx_tx)
return -ENOMEM;
sw_ctx_tx = ctx->priv_ctx_tx;
crypto_info = &ctx->crypto_send.info;
cctx = &ctx->tx;
aead = &sw_ctx_tx->aead_send;
} else {
ctx->priv_ctx_rx = init_ctx_rx(ctx);
if (!ctx->priv_ctx_rx)
return -ENOMEM;
sw_ctx_rx = ctx->priv_ctx_rx;
crypto_info = &ctx->crypto_recv.info;
cctx = &ctx->rx;
aead = &sw_ctx_rx->aead_recv;
}
cipher_desc = get_cipher_desc(crypto_info->cipher_type);
if (!cipher_desc) {
rc = -EINVAL;
goto free_priv;
}
rc = init_prot_info(prot, crypto_info, cipher_desc);
if (rc)
goto free_priv;
iv = crypto_info_iv(crypto_info, cipher_desc);
key = crypto_info_key(crypto_info, cipher_desc);
salt = crypto_info_salt(crypto_info, cipher_desc);
rec_seq = crypto_info_rec_seq(crypto_info, cipher_desc);
memcpy(cctx->iv, salt, cipher_desc->salt);
memcpy(cctx->iv + cipher_desc->salt, iv, cipher_desc->iv);
memcpy(cctx->rec_seq, rec_seq, cipher_desc->rec_seq);
if (!*aead) {
*aead = crypto_alloc_aead(cipher_desc->cipher_name, 0, 0);
if (IS_ERR(*aead)) {
rc = PTR_ERR(*aead);
*aead = NULL;
goto free_priv;
}
}
ctx->push_pending_record = tls_sw_push_pending_record;
rc = crypto_aead_setkey(*aead, key, cipher_desc->key);
if (rc)
goto free_aead;
rc = crypto_aead_setauthsize(*aead, prot->tag_size);
if (rc)
goto free_aead;
if (sw_ctx_rx) {
tfm = crypto_aead_tfm(sw_ctx_rx->aead_recv);
tls_update_rx_zc_capable(ctx);
sw_ctx_rx->async_capable =
crypto_info->version != TLS_1_3_VERSION &&
!!(tfm->__crt_alg->cra_flags & CRYPTO_ALG_ASYNC);
rc = tls_strp_init(&sw_ctx_rx->strp, sk);
if (rc)
goto free_aead;
}
goto out;
free_aead:
crypto_free_aead(*aead);
*aead = 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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