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tls_sw.c
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tls_sw.c
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/*
* Copyright (c) 2016-2017, Mellanox Technologies. All rights reserved.
* Copyright (c) 2016-2017, Dave Watson <[email protected]>. All rights reserved.
* Copyright (c) 2016-2017, Lance Chao <[email protected]>. All rights reserved.
* Copyright (c) 2016, Fridolin Pokorny <[email protected]>. All rights reserved.
* Copyright (c) 2016, Nikos Mavrogiannopoulos <[email protected]>. 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/sched/signal.h>
#include <linux/module.h>
#include <linux/splice.h>
#include <crypto/aead.h>
#include <net/strparser.h>
#include <net/tls.h>
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 padding_length(struct tls_sw_context_rx *ctx,
struct tls_prot_info *prot, struct sk_buff *skb)
{
struct strp_msg *rxm = strp_msg(skb);
int sub = 0;
/* Determine zero-padding length */
if (prot->version == TLS_1_3_VERSION) {
char content_type = 0;
int err;
int back = 17;
while (content_type == 0) {
if (back > rxm->full_len - prot->prepend_size)
return -EBADMSG;
err = skb_copy_bits(skb,
rxm->offset + rxm->full_len - back,
&content_type, 1);
if (err)
return err;
if (content_type)
break;
sub++;
back++;
}
ctx->control = content_type;
}
return sub;
}
static void tls_decrypt_done(struct crypto_async_request *req, int err)
{
struct aead_request *aead_req = (struct aead_request *)req;
struct scatterlist *sgout = aead_req->dst;
struct scatterlist *sgin = aead_req->src;
struct tls_sw_context_rx *ctx;
struct tls_context *tls_ctx;
struct tls_prot_info *prot;
struct scatterlist *sg;
struct sk_buff *skb;
unsigned int pages;
int pending;
skb = (struct sk_buff *)req->data;
tls_ctx = tls_get_ctx(skb->sk);
ctx = tls_sw_ctx_rx(tls_ctx);
prot = &tls_ctx->prot_info;
/* Propagate if there was an err */
if (err) {
if (err == -EBADMSG)
TLS_INC_STATS(sock_net(skb->sk),
LINUX_MIB_TLSDECRYPTERROR);
ctx->async_wait.err = err;
tls_err_abort(skb->sk, err);
} else {
struct strp_msg *rxm = strp_msg(skb);
int pad;
pad = padding_length(ctx, prot, skb);
if (pad < 0) {
ctx->async_wait.err = pad;
tls_err_abort(skb->sk, pad);
} else {
rxm->full_len -= pad;
rxm->offset += prot->prepend_size;
rxm->full_len -= prot->overhead_size;
}
}
/* After using skb->sk to propagate sk through crypto async callback
* we need to NULL it again.
*/
skb->sk = NULL;
/* Free the destination pages if skb was not decrypted inplace */
if (sgout != sgin) {
/* 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);
spin_lock_bh(&ctx->decrypt_compl_lock);
pending = atomic_dec_return(&ctx->decrypt_pending);
if (!pending && ctx->async_notify)
complete(&ctx->async_wait.completion);
spin_unlock_bh(&ctx->decrypt_compl_lock);
}
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_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 (async) {
/* Using skb->sk to push sk through to crypto async callback
* handler. This allows propagating errors up to the socket
* if needed. It _must_ be cleared in the async handler
* before consume_skb is called. We _know_ skb->sk is NULL
* because it is a clone from strparser.
*/
skb->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 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]);
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(struct crypto_async_request *req, int err)
{
struct aead_request *aead_req = (struct aead_request *)req;
struct sock *sk = req->data;
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 scatterlist *sge;
struct sk_msg *msg_en;
struct tls_rec *rec;
bool ready = false;
int pending;
rec = container_of(aead_req, struct tls_rec, aead_req);
msg_en = &rec->msg_encrypted;
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)
ready = true;
}
spin_lock_bh(&ctx->encrypt_compl_lock);
pending = atomic_dec_return(&ctx->encrypt_pending);
if (!pending && ctx->async_notify)
complete(&ctx->async_wait.completion);
spin_unlock_bh(&ctx->encrypt_compl_lock);
if (!ready)
return;
/* Schedule the transmission */
if (!test_and_set_bit(BIT_TX_SCHEDULED, &ctx->tx_bitmask))
schedule_delayed_work(&ctx->tx_work.work, 1);
}
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 */
if (prot->cipher_type == TLS_CIPHER_AES_CCM_128) {
rec->iv_data[0] = TLS_AES_CCM_IV_B0_BYTE;
iv_offset = 1;
}
memcpy(&rec->iv_data[iv_offset], tls_ctx->tx.iv,
prot->iv_size + prot->salt_size);
xor_iv_with_seq(prot, rec->iv_data, 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, sk);
/* Add the record in tx_list */
list_add_tail((struct list_head *)&rec->list, &ctx->tx_list);
atomic_inc(&ctx->encrypt_pending);
rc = crypto_aead_encrypt(aead_req);
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;
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 && 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 && 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:
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, &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);
}
int tls_sw_sendmsg(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;
int pending;
if (msg->msg_flags & ~(MSG_MORE | MSG_DONTWAIT | MSG_NOSIGNAL |
MSG_CMSG_COMPAT))
return -EOPNOTSUPP;
mutex_lock(&tls_ctx->tx_lock);
lock_sock(sk);
if (unlikely(msg->msg_controllen)) {
ret = tls_proccess_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;
}