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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/splice.h>
 #include <crypto/aead.h>
 
 #include <net/strparser.h>
 #include <net/tls.h>
 
 #include "tls.h"
 
 struct tls_decrypt_arg {
     struct_group(inargs,
     bool zc;
     bool async;
     u8 tail;
     );
 
     struct sk_buff *skb;
 };
 
 struct tls_decrypt_ctx {
     u8 iv[MAX_IV_SIZE];
     u8 aad[TLS_MAX_AAD_SIZE];
     u8 tail;
     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. */
     sk->sk_err = -err;
     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(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 scatterlist *sg;
     unsigned int pages;
     struct sock *sk;
 
     sk = (struct sock *)req->data;
     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 (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);
     if (!atomic_dec_return(&ctx->decrypt_pending))
         complete(&ctx->async_wait.completion);
     spin_unlock_bh(&ctx->decrypt_compl_lock);
 }
 
 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, sk);
         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 (darg->async)
             return 0;
 
         ret = crypto_wait_req(ret, &ctx->async_wait);
     }
     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]);
 
     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 */
     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, 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_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 (!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;
         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) {
         /* Wait for pending encryptions to get completed */
         spin_lock_bh(&ctx->encrypt_compl_lock);
         ctx->async_notify = true;
 
         pending = atomic_read(&ctx->encrypt_pending);
         spin_unlock_bh(&ctx->encrypt_compl_lock);
         if (pending)
             crypto_wait_req(-EINPROGRESS, &ctx->async_wait);
         else
             reinit_completion(&ctx->async_wait.completion);
 
         /* There can be no concurrent accesses, since we have no
          * pending encrypt operations
          */
         WRITE_ONCE(ctx->async_notify, false);
 
         if (ctx->async_wait.err) {
             ret = ctx->async_wait.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);
 
     release_sock(sk);
     mutex_unlock(&tls_ctx->tx_lock);
     return copied > 0 ? copied : ret;
 }
 
 static int tls_sw_do_sendpage(struct sock *sk, struct page *page,
                   int offset, size_t size, int flags)
 {
     long timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
     struct tls_context *tls_ctx = tls_get_ctx(sk);
     struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
     struct tls_prot_info *prot = &tls_ctx->prot_info;
     unsigned char record_type = TLS_RECORD_TYPE_DATA;
     struct sk_msg *msg_pl;
     struct tls_rec *rec;
     int num_async = 0;
     ssize_t copied = 0;
     bool full_record;
     int record_room;
     int ret = 0;
     bool eor;
 
     eor = !(flags & MSG_SENDPAGE_NOTLAST);
     sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
 
     /* 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;
         }
 
         if (ctx->open_rec)
             rec = ctx->open_rec;
         else
             rec = ctx->open_rec = tls_get_rec(sk);
         if (!rec) {
             ret = -ENOMEM;
             goto sendpage_end;
         }
 
         msg_pl = &rec->msg_plaintext;
 
         full_record = false;
         record_room = TLS_MAX_PAYLOAD_SIZE - msg_pl->sg.size;
         copy = size;
         if (copy >= record_room) {
             copy = record_room;
             full_record = true;
         }
 
         required_size = msg_pl->sg.size + copy + prot->overhead_size;
 
         if (!sk_stream_memory_free(sk))
             goto wait_for_sndbuf;
 alloc_payload:
         ret = tls_alloc_encrypted_msg(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 - msg_pl->sg.size;
             full_record = true;
         }
 
         sk_msg_page_add(msg_pl, page, copy, offset);
         sk_mem_charge(sk, copy);
 
         offset += copy;
         size -= copy;
         copied += copy;
 
         tls_ctx->pending_open_record_frags = true;
         if (full_record || eor || sk_msg_full(msg_pl)) {
             ret = bpf_exec_tx_verdict(msg_pl, sk, full_record,
                           record_type, &copied, 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 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) {
             if (ctx->open_rec)
                 tls_trim_both_msgs(sk, msg_pl->sg.size);
             goto sendpage_end;
         }
 
         if (ctx->open_rec)
             goto alloc_payload;
     }
 
     if (num_async) {
         /* 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, flags);
         }
     }
 sendpage_end:
     ret = sk_stream_error(sk, flags, ret);
     return copied > 0 ? copied : ret;
 }
 
 int tls_sw_sendpage_locked(struct sock *sk, struct page *page,
                int offset, size_t size, int flags)
 {
     if (flags & ~(MSG_MORE | MSG_DONTWAIT | MSG_NOSIGNAL |
               MSG_SENDPAGE_NOTLAST | MSG_SENDPAGE_NOPOLICY |
               MSG_NO_SHARED_FRAGS))
         return -EOPNOTSUPP;
 
     return tls_sw_do_sendpage(sk, page, offset, size, flags);
 }
 
 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);
     int ret;
 
     if (flags & ~(MSG_MORE | MSG_DONTWAIT | MSG_NOSIGNAL |
               MSG_SENDPAGE_NOTLAST | MSG_SENDPAGE_NOPOLICY))
         return -EOPNOTSUPP;
 
     mutex_lock(&tls_ctx->tx_lock);
     lock_sock(sk);
     ret = tls_sw_do_sendpage(sk, page, offset, size, flags);
     release_sock(sk);
     mutex_unlock(&tls_ctx->tx_lock);
     return ret;
 }
 
 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);
     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 (!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);
         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);
     mem = kmalloc(aead_size + struct_size(dctx, sg, 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);
     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));
     }
 
     /* Prepare and submit AEAD request */
     err = tls_do_decryption(sk, sgin, sgout, dctx->iv,
                 data_len + prot->tail_size, aead_req, darg);
     if (err)
         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 (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)
 {
     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 out;
 
         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 out;
 
         err = skb_copy_datagram_msg(skb, rxm->offset + skip,
                         msg, chunk);
         if (err < 0)
             goto out;
 
         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;
 }
 
 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_lock(struct sock *sk, struct tls_sw_context_rx *ctx,
                   bool nonblock)
 {
     long timeo;
     int err;
 
     lock_sock(sk);
 
     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);
         sk_wait_event(sk, &timeo,
                   !READ_ONCE(ctx->reader_present), &wait);
         remove_wait_queue(&ctx->wq, &wait);
 
         if (timeo <= 0) {
             err = -EAGAIN;
             goto err_unlock;
         }
         if (signal_pending(current)) {
             err = sock_intr_errno(timeo);
             goto err_unlock;
         }
     }
 
     WRITE_ONCE(ctx->reader_present, 1);
 
     return 0;
 
 err_unlock:
     release_sock(sk);
     return err;
 }
 
 static void tls_rx_reader_unlock(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);
     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;
     bool async = false;
     int target, err;
     bool is_kvec = iov_iter_is_kvec(&msg->msg_iter);
     bool is_peek = flags & MSG_PEEK;
     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);
 
     psock = sk_psock_get(sk);
     err = tls_rx_reader_lock(sk, ctx, flags & MSG_DONTWAIT);
     if (err < 0)
         return err;
     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);
     if (err < 0)
         goto end;
 
     copied = err;
     if (len <= copied)
         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);
                 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)
                 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, pending;
 
         /* Wait for all previously submitted records to be decrypted */
         spin_lock_bh(&ctx->decrypt_compl_lock);
         reinit_completion(&ctx->async_wait.completion);
         pending = atomic_read(&ctx->decrypt_pending);
         spin_unlock_bh(&ctx->decrypt_compl_lock);
         ret = 0;
         if (pending)
             ret = crypto_wait_req(-EINPROGRESS, &ctx->async_wait);
         __skb_queue_purge(&ctx->async_hold);
 
         if (ret) {
             if (err >= 0 || err == -EINPROGRESS)
                 err = ret;
             decrypted = 0;
             goto end;
         }
 
         /* Drain records from the rx_list & copy if required */
         if (is_peek || is_kvec)
             err = process_rx_list(ctx, msg, &control, copied,
                           decrypted, is_peek);
         else
             err = process_rx_list(ctx, msg, &control, 0,
                           async_copy_bytes, is_peek);
         decrypted = max(err, 0);
     }
 
     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;
 }
 
 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 + 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;
 
     tls_strp_data_ready(&ctx->strp);
 
     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;
     int pending;
 
     /* Wait for any pending async encryptions to complete */
     spin_lock_bh(&ctx->encrypt_compl_lock);
     ctx->async_notify = true;
     pending = atomic_read(&ctx->encrypt_pending);
     spin_unlock_bh(&ctx->encrypt_compl_lock);
 
     if (pending)
         crypto_wait_req(-EINPROGRESS, &ctx->async_wait);
 
     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);
 
     kfree(tls_ctx->rx.rec_seq);
     kfree(tls_ctx->rx.iv);
 
     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;
     mutex_lock(&tls_ctx->tx_lock);
     lock_sock(sk);
     tls_tx_records(sk, -1);
     release_sock(sk);
     mutex_unlock(&tls_ctx->tx_lock);
 }
 
 static bool tls_is_tx_ready(struct tls_sw_context_tx *ctx)
 {
     struct tls_rec *rec;
 
     rec = list_first_entry(&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;
 }
 
 int tls_set_sw_offload(struct sock *sk, struct tls_context *ctx, int tx)
 {
     struct tls_context *tls_ctx = tls_get_ctx(sk);
     struct tls_prot_info *prot = &tls_ctx->prot_info;
     struct tls_crypto_info *crypto_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;
     u16 nonce_size, tag_size, iv_size, rec_seq_size, salt_size;
     struct crypto_tfm *tfm;
     char *iv, *rec_seq, *key, *salt, *cipher_name;
     size_t keysize;
     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);
         spin_lock_init(&sw_ctx_tx->encrypt_compl_lock);
         crypto_info = &ctx->crypto_send.info;
         cctx = &ctx->tx;
         aead = &sw_ctx_tx->aead_send;
         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;
     } else {
         crypto_init_wait(&sw_ctx_rx->async_wait);
         spin_lock_init(&sw_ctx_rx->decrypt_compl_lock);
         init_waitqueue_head(&sw_ctx_rx->wq);
         crypto_info = &ctx->crypto_recv.info;
         cctx = &ctx->rx;
         skb_queue_head_init(&sw_ctx_rx->rx_list);
         skb_queue_head_init(&sw_ctx_rx->async_hold);
         aead = &sw_ctx_rx->aead_recv;
     }
 
     switch (crypto_info->cipher_type) {
     case TLS_CIPHER_AES_GCM_128: {
         struct tls12_crypto_info_aes_gcm_128 *gcm_128_info;
 
         gcm_128_info = (void *)crypto_info;
         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 = gcm_128_info->iv;
         rec_seq_size = TLS_CIPHER_AES_GCM_128_REC_SEQ_SIZE;
         rec_seq = gcm_128_info->rec_seq;
         keysize = TLS_CIPHER_AES_GCM_128_KEY_SIZE;
         key = gcm_128_info->key;
         salt = gcm_128_info->salt;
         salt_size = TLS_CIPHER_AES_GCM_128_SALT_SIZE;
         cipher_name = "gcm(aes)";
         break;
     }
     case TLS_CIPHER_AES_GCM_256: {
         struct tls12_crypto_info_aes_gcm_256 *gcm_256_info;
 
         gcm_256_info = (void *)crypto_info;
         nonce_size = TLS_CIPHER_AES_GCM_256_IV_SIZE;
         tag_size = TLS_CIPHER_AES_GCM_256_TAG_SIZE;
         iv_size = TLS_CIPHER_AES_GCM_256_IV_SIZE;
         iv = gcm_256_info->iv;
         rec_seq_size = TLS_CIPHER_AES_GCM_256_REC_SEQ_SIZE;
         rec_seq = gcm_256_info->rec_seq;
         keysize = TLS_CIPHER_AES_GCM_256_KEY_SIZE;
         key = gcm_256_info->key;
         salt = gcm_256_info->salt;
         salt_size = TLS_CIPHER_AES_GCM_256_SALT_SIZE;
         cipher_name = "gcm(aes)";
         break;
     }
     case TLS_CIPHER_AES_CCM_128: {
         struct tls12_crypto_info_aes_ccm_128 *ccm_128_info;
 
         ccm_128_info = (void *)crypto_info;
         nonce_size = TLS_CIPHER_AES_CCM_128_IV_SIZE;
         tag_size = TLS_CIPHER_AES_CCM_128_TAG_SIZE;
         iv_size = TLS_CIPHER_AES_CCM_128_IV_SIZE;
         iv = ccm_128_info->iv;
         rec_seq_size = TLS_CIPHER_AES_CCM_128_REC_SEQ_SIZE;
         rec_seq = ccm_128_info->rec_seq;
         keysize = TLS_CIPHER_AES_CCM_128_KEY_SIZE;
         key = ccm_128_info->key;
         salt = ccm_128_info->salt;
         salt_size = TLS_CIPHER_AES_CCM_128_SALT_SIZE;
         cipher_name = "ccm(aes)";
         break;
     }
     case TLS_CIPHER_CHACHA20_POLY1305: {
         struct tls12_crypto_info_chacha20_poly1305 *chacha20_poly1305_info;
 
         chacha20_poly1305_info = (void *)crypto_info;
         nonce_size = 0;
         tag_size = TLS_CIPHER_CHACHA20_POLY1305_TAG_SIZE;
         iv_size = TLS_CIPHER_CHACHA20_POLY1305_IV_SIZE;
         iv = chacha20_poly1305_info->iv;
         rec_seq_size = TLS_CIPHER_CHACHA20_POLY1305_REC_SEQ_SIZE;
         rec_seq = chacha20_poly1305_info->rec_seq;
         keysize = TLS_CIPHER_CHACHA20_POLY1305_KEY_SIZE;
         key = chacha20_poly1305_info->key;
         salt = chacha20_poly1305_info->salt;
         salt_size = TLS_CIPHER_CHACHA20_POLY1305_SALT_SIZE;
         cipher_name = "rfc7539(chacha20,poly1305)";
         break;
     }
     case TLS_CIPHER_SM4_GCM: {
         struct tls12_crypto_info_sm4_gcm *sm4_gcm_info;
 
         sm4_gcm_info = (void *)crypto_info;
         nonce_size = TLS_CIPHER_SM4_GCM_IV_SIZE;
         tag_size = TLS_CIPHER_SM4_GCM_TAG_SIZE;
         iv_size = TLS_CIPHER_SM4_GCM_IV_SIZE;
         iv = sm4_gcm_info->iv;
         rec_seq_size = TLS_CIPHER_SM4_GCM_REC_SEQ_SIZE;
         rec_seq = sm4_gcm_info->rec_seq;
         keysize = TLS_CIPHER_SM4_GCM_KEY_SIZE;
         key = sm4_gcm_info->key;
         salt = sm4_gcm_info->salt;
         salt_size = TLS_CIPHER_SM4_GCM_SALT_SIZE;
         cipher_name = "gcm(sm4)";
         break;
     }
     case TLS_CIPHER_SM4_CCM: {
         struct tls12_crypto_info_sm4_ccm *sm4_ccm_info;
 
         sm4_ccm_info = (void *)crypto_info;
         nonce_size = TLS_CIPHER_SM4_CCM_IV_SIZE;
         tag_size = TLS_CIPHER_SM4_CCM_TAG_SIZE;
         iv_size = TLS_CIPHER_SM4_CCM_IV_SIZE;
         iv = sm4_ccm_info->iv;
         rec_seq_size = TLS_CIPHER_SM4_CCM_REC_SEQ_SIZE;
         rec_seq = sm4_ccm_info->rec_seq;
         keysize = TLS_CIPHER_SM4_CCM_KEY_SIZE;
         key = sm4_ccm_info->key;
         salt = sm4_ccm_info->salt;
         salt_size = TLS_CIPHER_SM4_CCM_SALT_SIZE;
         cipher_name = "ccm(sm4)";
         break;
     }
     default:
         rc = -EINVAL;
         goto free_priv;
     }
 
     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 (iv_size > MAX_IV_SIZE || nonce_size > MAX_IV_SIZE ||
         rec_seq_size > TLS_MAX_REC_SEQ_SIZE || tag_size != TLS_TAG_SIZE ||
         prot->aad_size > TLS_MAX_AAD_SIZE) {
         rc = -EINVAL;
         goto free_priv;
     }
 
     prot->version = crypto_info->version;
     prot->cipher_type = crypto_info->cipher_type;
     prot->prepend_size = TLS_HEADER_SIZE + nonce_size;
     prot->tag_size = tag_size;
     prot->overhead_size = prot->prepend_size +
                   prot->tag_size + prot->tail_size;
     prot->iv_size = iv_size;
     prot->salt_size = salt_size;
     cctx->iv = kmalloc(iv_size + salt_size, GFP_KERNEL);
     if (!cctx->iv) {
         rc = -ENOMEM;
         goto free_priv;
     }
     /* Note: 128 & 256 bit salt are the same size */
     prot->rec_seq_size = rec_seq_size;
     memcpy(cctx->iv, salt, salt_size);
     memcpy(cctx->iv + salt_size, iv, iv_size);
     cctx->rec_seq = kmemdup(rec_seq, rec_seq_size, GFP_KERNEL);
     if (!cctx->rec_seq) {
         rc = -ENOMEM;
         goto free_iv;
     }
 
     if (!*aead) {
         *aead = crypto_alloc_aead(cipher_name, 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;
 
     rc = crypto_aead_setkey(*aead, key, keysize);
 
     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_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;
 }