text: /*
   * Copyright (c) 2016-2017, Mellanox Technologies. All rights reserved.
   * Copyright (c) 2016-2017, Dave Watson <davejwatson@fb.com>. All rights reserved.
   * Copyright (c) 2016-2017, Lance Chao <lancerchao@fb.com>. All rights reserved.
   * Copyright (c) 2016, Fridolin Pokorny <fridolin.pokorny@gmail.com>. All rights reserved.
   * Copyright (c) 2016, Nikos Mavrogiannopoulos <nmav@gnutls.org>. All rights reserved.
   *
   * This software is available to you under a choice of one of two
   * licenses.  You may choose to be licensed under the terms of the GNU
   * General Public License (GPL) Version 2, available from the file
   * COPYING in the main directory of this source tree, or the
   * OpenIB.org BSD license below:
   *
   *     Redistribution and use in source and binary forms, with or
   *     without modification, are permitted provided that the following
   *     conditions are met:
   *
   *      - Redistributions of source code must retain the above
   *        copyright notice, this list of conditions and the following
   *        disclaimer.
   *
   *      - Redistributions in binary form must reproduce the above
   *        copyright notice, this list of conditions and the following
   *        disclaimer in the documentation and/or other materials
   *        provided with the distribution.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
   * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
   * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
   * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
   * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
   * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
   * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
   * SOFTWARE.
   */
  
  #include <linux/module.h>
  #include <crypto/aead.h>
  
  #include <net/tls.h>
  
  static inline void tls_make_aad(int recv,
  				char *buf,
  				size_t size,
  				char *record_sequence,
  				int record_sequence_size,
  				unsigned char record_type)
  {
  	memcpy(buf, record_sequence, record_sequence_size);
  
  	buf[8] = record_type;
  	buf[9] = TLS_1_2_VERSION_MAJOR;
  	buf[10] = TLS_1_2_VERSION_MINOR;
  	buf[11] = size >> 8;
  	buf[12] = size & 0xFF;
  }
  
  static void trim_sg(struct sock *sk, struct scatterlist *sg,
  		    int *sg_num_elem, unsigned int *sg_size, int target_size)
  {
  	int i = *sg_num_elem - 1;
  	int trim = *sg_size - target_size;
  
  	if (trim <= 0) {
  		WARN_ON(trim < 0);
  		return;
  	}
  
  	*sg_size = target_size;
  	while (trim >= sg[i].length) {
  		trim -= sg[i].length;
  		sk_mem_uncharge(sk, sg[i].length);
  		put_page(sg_page(&sg[i]));
  		i--;
  
  		if (i < 0)
  			goto out;
  	}
  
  	sg[i].length -= trim;
  	sk_mem_uncharge(sk, trim);
  
  out:
  	*sg_num_elem = i + 1;
  }
  
  static void trim_both_sgl(struct sock *sk, int target_size)
  {
  	struct tls_context *tls_ctx = tls_get_ctx(sk);
  	struct tls_sw_context *ctx = tls_sw_ctx(tls_ctx);
  
  	trim_sg(sk, ctx->sg_plaintext_data,
  		&ctx->sg_plaintext_num_elem,
  		&ctx->sg_plaintext_size,
  		target_size);
  
  	if (target_size > 0)
  		target_size += tls_ctx->overhead_size;
  
  	trim_sg(sk, ctx->sg_encrypted_data,
  		&ctx->sg_encrypted_num_elem,
  		&ctx->sg_encrypted_size,
  		target_size);
  }
  
  static int alloc_sg(struct sock *sk, int len, struct scatterlist *sg,
  		    int *sg_num_elem, unsigned int *sg_size,
  		    int first_coalesce)
  {
  	struct page_frag *pfrag;
  	unsigned int size = *sg_size;
  	int num_elem = *sg_num_elem, use = 0, rc = 0;
  	struct scatterlist *sge;
  	unsigned int orig_offset;
  
  	len -= size;
  	pfrag = sk_page_frag(sk);
  
  	while (len > 0) {
  		if (!sk_page_frag_refill(sk, pfrag)) {
  			rc = -ENOMEM;
  			goto out;
  		}
  
  		use = min_t(int, len, pfrag->size - pfrag->offset);
  
  		if (!sk_wmem_schedule(sk, use)) {
  			rc = -ENOMEM;
  			goto out;
  		}
  
  		sk_mem_charge(sk, use);
  		size += use;
  		orig_offset = pfrag->offset;
  		pfrag->offset += use;
  
  		sge = sg + num_elem - 1;
  
  		if (num_elem > first_coalesce && sg_page(sge) == pfrag->page &&
  		    sge->offset + sge->length == orig_offset) {
  			sge->length += use;
  		} else {
  			sge++;
  			sg_unmark_end(sge);
  			sg_set_page(sge, pfrag->page, use, orig_offset);
  			get_page(pfrag->page);
  			++num_elem;
  			if (num_elem == MAX_SKB_FRAGS) {
  				rc = -ENOSPC;
  				break;
  			}
  		}
  
  		len -= use;
  	}
  	goto out;
  
  out:
  	*sg_size = size;
  	*sg_num_elem = num_elem;
  	return rc;
  }
  
  static int alloc_encrypted_sg(struct sock *sk, int len)
  {
  	struct tls_context *tls_ctx = tls_get_ctx(sk);
  	struct tls_sw_context *ctx = tls_sw_ctx(tls_ctx);
  	int rc = 0;
  
  	rc = alloc_sg(sk, len, ctx->sg_encrypted_data,
  		      &ctx->sg_encrypted_num_elem, &ctx->sg_encrypted_size, 0);
  
  	if (rc == -ENOSPC)
  		ctx->sg_encrypted_num_elem = ARRAY_SIZE(ctx->sg_encrypted_data);
  
  	return rc;
  }
  
  static int alloc_plaintext_sg(struct sock *sk, int len)
  {
  	struct tls_context *tls_ctx = tls_get_ctx(sk);
  	struct tls_sw_context *ctx = tls_sw_ctx(tls_ctx);
  	int rc = 0;
  
  	rc = alloc_sg(sk, len, ctx->sg_plaintext_data,
  		      &ctx->sg_plaintext_num_elem, &ctx->sg_plaintext_size,
  		      tls_ctx->pending_open_record_frags);
  
  	if (rc == -ENOSPC)
  		ctx->sg_plaintext_num_elem = ARRAY_SIZE(ctx->sg_plaintext_data);
  
  	return rc;
  }
  
  static void free_sg(struct sock *sk, struct scatterlist *sg,
  		    int *sg_num_elem, unsigned int *sg_size)
  {
  	int i, n = *sg_num_elem;
  
  	for (i = 0; i < n; ++i) {
  		sk_mem_uncharge(sk, sg[i].length);
  		put_page(sg_page(&sg[i]));
  	}
  	*sg_num_elem = 0;
  	*sg_size = 0;
  }
  
  static void tls_free_both_sg(struct sock *sk)
  {
  	struct tls_context *tls_ctx = tls_get_ctx(sk);
  	struct tls_sw_context *ctx = tls_sw_ctx(tls_ctx);
  
  	free_sg(sk, ctx->sg_encrypted_data, &ctx->sg_encrypted_num_elem,
  		&ctx->sg_encrypted_size);
  
  	free_sg(sk, ctx->sg_plaintext_data, &ctx->sg_plaintext_num_elem,
  		&ctx->sg_plaintext_size);
  }
  
  static int tls_do_encryption(struct tls_context *tls_ctx,
  			     struct tls_sw_context *ctx,
  			     struct aead_request *aead_req,
  			     size_t data_len)
  {
  	int rc;
  
  	ctx->sg_encrypted_data[0].offset += tls_ctx->prepend_size;
  	ctx->sg_encrypted_data[0].length -= tls_ctx->prepend_size;
  
  	aead_request_set_tfm(aead_req, ctx->aead_send);
  	aead_request_set_ad(aead_req, TLS_AAD_SPACE_SIZE);
  	aead_request_set_crypt(aead_req, ctx->sg_aead_in, ctx->sg_aead_out,
  			       data_len, tls_ctx->iv);
  	rc = crypto_aead_encrypt(aead_req);
  
  	ctx->sg_encrypted_data[0].offset -= tls_ctx->prepend_size;
  	ctx->sg_encrypted_data[0].length += tls_ctx->prepend_size;
  
  	return rc;
  }
  
  static int tls_push_record(struct sock *sk, int flags,
  			   unsigned char record_type)
  {
  	struct tls_context *tls_ctx = tls_get_ctx(sk);
  	struct tls_sw_context *ctx = tls_sw_ctx(tls_ctx);
  	struct aead_request *req;
  	int rc;
  
  	req = kzalloc(sizeof(struct aead_request) +
  		      crypto_aead_reqsize(ctx->aead_send), sk->sk_allocation);
  	if (!req)
  		return -ENOMEM;
  
  	sg_mark_end(ctx->sg_plaintext_data + ctx->sg_plaintext_num_elem - 1);
  	sg_mark_end(ctx->sg_encrypted_data + ctx->sg_encrypted_num_elem - 1);
  
  	tls_make_aad(0, ctx->aad_space, ctx->sg_plaintext_size,
  		     tls_ctx->rec_seq, tls_ctx->rec_seq_size,
  		     record_type);
  
  	tls_fill_prepend(tls_ctx,
  			 page_address(sg_page(&ctx->sg_encrypted_data[0])) +
  			 ctx->sg_encrypted_data[0].offset,
  			 ctx->sg_plaintext_size, record_type);
  
  	tls_ctx->pending_open_record_frags = 0;
  	set_bit(TLS_PENDING_CLOSED_RECORD, &tls_ctx->flags);
  
  	rc = tls_do_encryption(tls_ctx, ctx, req, ctx->sg_plaintext_size);
  	if (rc < 0) {
  		/* If we are called from write_space and
  		 * we fail, we need to set this SOCK_NOSPACE
  		 * to trigger another write_space in the future.
  		 */
  		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
  		goto out_req;
  	}
  
  	free_sg(sk, ctx->sg_plaintext_data, &ctx->sg_plaintext_num_elem,
  		&ctx->sg_plaintext_size);
  
  	ctx->sg_encrypted_num_elem = 0;
  	ctx->sg_encrypted_size = 0;
  
  	/* Only pass through MSG_DONTWAIT and MSG_NOSIGNAL flags */
  	rc = tls_push_sg(sk, tls_ctx, ctx->sg_encrypted_data, 0, flags);
  	if (rc < 0 && rc != -EAGAIN)
  		tls_err_abort(sk);
  
  	tls_advance_record_sn(sk, tls_ctx);
  out_req:
  	kfree(req);
  	return rc;
  }
  
  static int tls_sw_push_pending_record(struct sock *sk, int flags)
  {
  	return tls_push_record(sk, flags, TLS_RECORD_TYPE_DATA);
  }
  
  static int zerocopy_from_iter(struct sock *sk, struct iov_iter *from,
  			      int length)
  {
  	struct tls_context *tls_ctx = tls_get_ctx(sk);
  	struct tls_sw_context *ctx = tls_sw_ctx(tls_ctx);
  	struct page *pages[MAX_SKB_FRAGS];
  
  	size_t offset;
  	ssize_t copied, use;
  	int i = 0;
  	unsigned int size = ctx->sg_plaintext_size;
  	int num_elem = ctx->sg_plaintext_num_elem;
  	int rc = 0;
  	int maxpages;
  
  	while (length > 0) {
  		i = 0;
  		maxpages = ARRAY_SIZE(ctx->sg_plaintext_data) - num_elem;
  		if (maxpages == 0) {
  			rc = -EFAULT;
  			goto out;
  		}
  		copied = iov_iter_get_pages(from, pages,
  					    length,
  					    maxpages, &offset);
  		if (copied <= 0) {
  			rc = -EFAULT;
  			goto out;
  		}
  
  		iov_iter_advance(from, copied);
  
  		length -= copied;
  		size += copied;
  		while (copied) {
  			use = min_t(int, copied, PAGE_SIZE - offset);
  
  			sg_set_page(&ctx->sg_plaintext_data[num_elem],
  				    pages[i], use, offset);
  			sg_unmark_end(&ctx->sg_plaintext_data[num_elem]);
  			sk_mem_charge(sk, use);
  
  			offset = 0;
  			copied -= use;
  
  			++i;
  			++num_elem;
  		}
  	}
  
  out:
  	ctx->sg_plaintext_size = size;
  	ctx->sg_plaintext_num_elem = num_elem;
  	return rc;
  }
  
  static int memcopy_from_iter(struct sock *sk, struct iov_iter *from,
  			     int bytes)
  {
  	struct tls_context *tls_ctx = tls_get_ctx(sk);
  	struct tls_sw_context *ctx = tls_sw_ctx(tls_ctx);
  	struct scatterlist *sg = ctx->sg_plaintext_data;
  	int copy, i, rc = 0;
  
  	for (i = tls_ctx->pending_open_record_frags;
  	     i < ctx->sg_plaintext_num_elem; ++i) {
  		copy = sg[i].length;
  		if (copy_from_iter(
  				page_address(sg_page(&sg[i])) + sg[i].offset,
  				copy, from) != copy) {
  			rc = -EFAULT;
  			goto out;
  		}
  		bytes -= copy;
  
  		++tls_ctx->pending_open_record_frags;
  
  		if (!bytes)
  			break;
  	}
  
  out:
  	return rc;
  }
  
  int tls_sw_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
  {
  	struct tls_context *tls_ctx = tls_get_ctx(sk);
  	struct tls_sw_context *ctx = tls_sw_ctx(tls_ctx);
  	int ret;
  	int required_size;
  	long timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
  	bool eor = !(msg->msg_flags & MSG_MORE);
  	size_t try_to_copy, copied = 0;
  	unsigned char record_type = TLS_RECORD_TYPE_DATA;
  	int record_room;
  	bool full_record;
  	int orig_size;
  
  	if (msg->msg_flags & ~(MSG_MORE | MSG_DONTWAIT | MSG_NOSIGNAL))
  		return -ENOTSUPP;
  
  	lock_sock(sk);
  
  	ret = tls_complete_pending_work(sk, tls_ctx, msg->msg_flags, &timeo);
  	if (ret)
  		goto send_end;
  
  	if (unlikely(msg->msg_controllen)) {
  		ret = tls_proccess_cmsg(sk, msg, &record_type);
  		if (ret)
  			goto send_end;
  	}
  
  	while (msg_data_left(msg)) {
  		if (sk->sk_err) {
  			ret = -sk->sk_err;
  			goto send_end;
  		}
  
  		orig_size = ctx->sg_plaintext_size;
  		full_record = false;
  		try_to_copy = msg_data_left(msg);
  		record_room = TLS_MAX_PAYLOAD_SIZE - ctx->sg_plaintext_size;
  		if (try_to_copy >= record_room) {
  			try_to_copy = record_room;
  			full_record = true;
  		}
  
  		required_size = ctx->sg_plaintext_size + try_to_copy +
  				tls_ctx->overhead_size;
  
  		if (!sk_stream_memory_free(sk))
  			goto wait_for_sndbuf;
  alloc_encrypted:
  		ret = alloc_encrypted_sg(sk, required_size);
  		if (ret) {
  			if (ret != -ENOSPC)
  				goto wait_for_memory;
  
  			/* Adjust try_to_copy according to the amount that was
  			 * actually allocated. The difference is due
  			 * to max sg elements limit
  			 */
  			try_to_copy -= required_size - ctx->sg_encrypted_size;
  			full_record = true;
  		}
  
  		if (full_record || eor) {
  			ret = zerocopy_from_iter(sk, &msg->msg_iter,
  						 try_to_copy);
  			if (ret)
  				goto fallback_to_reg_send;
  
  			copied += try_to_copy;
  			ret = tls_push_record(sk, msg->msg_flags, record_type);
  			if (!ret)
  				continue;
  			if (ret < 0)
  				goto send_end;
  
  			copied -= try_to_copy;
  fallback_to_reg_send:
  			iov_iter_revert(&msg->msg_iter,
  					ctx->sg_plaintext_size - orig_size);
  			trim_sg(sk, ctx->sg_plaintext_data,
  				&ctx->sg_plaintext_num_elem,
  				&ctx->sg_plaintext_size,
  				orig_size);
  		}
  
  		required_size = ctx->sg_plaintext_size + try_to_copy;
  alloc_plaintext:
  		ret = alloc_plaintext_sg(sk, required_size);
  		if (ret) {
  			if (ret != -ENOSPC)
  				goto wait_for_memory;
  
  			/* Adjust try_to_copy according to the amount that was
  			 * actually allocated. The difference is due
  			 * to max sg elements limit
  			 */
  			try_to_copy -= required_size - ctx->sg_plaintext_size;
  			full_record = true;
  
  			trim_sg(sk, ctx->sg_encrypted_data,
  				&ctx->sg_encrypted_num_elem,
  				&ctx->sg_encrypted_size,
  				ctx->sg_plaintext_size +
  				tls_ctx->overhead_size);
  		}
  
  		ret = memcopy_from_iter(sk, &msg->msg_iter, try_to_copy);
  		if (ret)
  			goto trim_sgl;
  
  		copied += try_to_copy;
  		if (full_record || eor) {
  push_record:
  			ret = tls_push_record(sk, msg->msg_flags, record_type);
  			if (ret) {
  				if (ret == -ENOMEM)
  					goto wait_for_memory;
  
  				goto send_end;
  			}
  		}
  
  		continue;
  
  wait_for_sndbuf:
  		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
  wait_for_memory:
  		ret = sk_stream_wait_memory(sk, &timeo);
  		if (ret) {
  trim_sgl:
  			trim_both_sgl(sk, orig_size);
  			goto send_end;
  		}
  
  		if (tls_is_pending_closed_record(tls_ctx))
  			goto push_record;
  
  		if (ctx->sg_encrypted_size < required_size)
  			goto alloc_encrypted;
  
  		goto alloc_plaintext;
  	}
  
  send_end:
  	ret = sk_stream_error(sk, msg->msg_flags, ret);
  
  	release_sock(sk);
  	return copied ? copied : ret;
  }
  
  int tls_sw_sendpage(struct sock *sk, struct page *page,
  		    int offset, size_t size, int flags)
  {
  	struct tls_context *tls_ctx = tls_get_ctx(sk);
  	struct tls_sw_context *ctx = tls_sw_ctx(tls_ctx);
  	int ret;
  	long timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
  	bool eor;
  	size_t orig_size = size;
  	unsigned char record_type = TLS_RECORD_TYPE_DATA;
  	struct scatterlist *sg;
  	bool full_record;
  	int record_room;
  
  	if (flags & ~(MSG_MORE | MSG_DONTWAIT | MSG_NOSIGNAL |
  		      MSG_SENDPAGE_NOTLAST))
  		return -ENOTSUPP;
  
  	/* No MSG_EOR from splice, only look at MSG_MORE */
  	eor = !(flags & (MSG_MORE | MSG_SENDPAGE_NOTLAST));
  
  	lock_sock(sk);
  
  	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
  
  	ret = tls_complete_pending_work(sk, tls_ctx, flags, &timeo);
  	if (ret)
  		goto sendpage_end;
  
  	/* Call the sk_stream functions to manage the sndbuf mem. */
  	while (size > 0) {
  		size_t copy, required_size;
  
  		if (sk->sk_err) {
  			ret = -sk->sk_err;
  			goto sendpage_end;
  		}
  
  		full_record = false;
  		record_room = TLS_MAX_PAYLOAD_SIZE - ctx->sg_plaintext_size;
  		copy = size;
  		if (copy >= record_room) {
  			copy = record_room;
  			full_record = true;
  		}
  		required_size = ctx->sg_plaintext_size + copy +
  			      tls_ctx->overhead_size;
  
  		if (!sk_stream_memory_free(sk))
  			goto wait_for_sndbuf;
  alloc_payload:
  		ret = alloc_encrypted_sg(sk, required_size);
  		if (ret) {
  			if (ret != -ENOSPC)
  				goto wait_for_memory;
  
  			/* Adjust copy according to the amount that was
  			 * actually allocated. The difference is due
  			 * to max sg elements limit
  			 */
  			copy -= required_size - ctx->sg_plaintext_size;
  			full_record = true;
  		}
  
  		get_page(page);
  		sg = ctx->sg_plaintext_data + ctx->sg_plaintext_num_elem;
  		sg_set_page(sg, page, copy, offset);
  		ctx->sg_plaintext_num_elem++;
  
  		sk_mem_charge(sk, copy);
  		offset += copy;
  		size -= copy;
  		ctx->sg_plaintext_size += copy;
  		tls_ctx->pending_open_record_frags = ctx->sg_plaintext_num_elem;
  
  		if (full_record || eor ||
  		    ctx->sg_plaintext_num_elem ==
  		    ARRAY_SIZE(ctx->sg_plaintext_data)) {
  push_record:
  			ret = tls_push_record(sk, flags, record_type);
  			if (ret) {
  				if (ret == -ENOMEM)
  					goto wait_for_memory;
  
  				goto sendpage_end;
  			}
  		}
  		continue;
  wait_for_sndbuf:
  		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
  wait_for_memory:
  		ret = sk_stream_wait_memory(sk, &timeo);
  		if (ret) {
  			trim_both_sgl(sk, ctx->sg_plaintext_size);
  			goto sendpage_end;
  		}
  
  		if (tls_is_pending_closed_record(tls_ctx))
  			goto push_record;
  
  		goto alloc_payload;
  	}
  
  sendpage_end:
  	if (orig_size > size)
  		ret = orig_size - size;
  	else
  		ret = sk_stream_error(sk, flags, ret);
  
  	release_sock(sk);
  	return ret;
  }
  
  void tls_sw_free_tx_resources(struct sock *sk)
  {
  	struct tls_context *tls_ctx = tls_get_ctx(sk);
  	struct tls_sw_context *ctx = tls_sw_ctx(tls_ctx);
  
  	if (ctx->aead_send)
  		crypto_free_aead(ctx->aead_send);
  
  	tls_free_both_sg(sk);
  
  	kfree(ctx);
  }
  
  int tls_set_sw_offload(struct sock *sk, struct tls_context *ctx)
  {
  	struct tls_crypto_info *crypto_info;
  	struct tls12_crypto_info_aes_gcm_128 *gcm_128_info;
  	struct tls_sw_context *sw_ctx;
  	u16 nonce_size, tag_size, iv_size, rec_seq_size;
  	char *iv, *rec_seq;
  	int rc = 0;
  
  	if (!ctx) {
  		rc = -EINVAL;
  		goto out;
  	}
  
  	if (ctx->priv_ctx) {
  		rc = -EEXIST;
  		goto out;
  	}
  
  	sw_ctx = kzalloc(sizeof(*sw_ctx), GFP_KERNEL);
  	if (!sw_ctx) {
  		rc = -ENOMEM;
  		goto out;
  	}
  
  	ctx->priv_ctx = (struct tls_offload_context *)sw_ctx;
  
  	crypto_info = &ctx->crypto_send.info;
  	switch (crypto_info->cipher_type) {
  	case TLS_CIPHER_AES_GCM_128: {
  		nonce_size = TLS_CIPHER_AES_GCM_128_IV_SIZE;
  		tag_size = TLS_CIPHER_AES_GCM_128_TAG_SIZE;
  		iv_size = TLS_CIPHER_AES_GCM_128_IV_SIZE;
  		iv = ((struct tls12_crypto_info_aes_gcm_128 *)crypto_info)->iv;
  		rec_seq_size = TLS_CIPHER_AES_GCM_128_REC_SEQ_SIZE;
  		rec_seq =
  		 ((struct tls12_crypto_info_aes_gcm_128 *)crypto_info)->rec_seq;
  		gcm_128_info =
  			(struct tls12_crypto_info_aes_gcm_128 *)crypto_info;
  		break;
  	}
  	default:
  		rc = -EINVAL;
  		goto free_priv;
  	}
  
  	ctx->prepend_size = TLS_HEADER_SIZE + nonce_size;
  	ctx->tag_size = tag_size;
  	ctx->overhead_size = ctx->prepend_size + ctx->tag_size;
  	ctx->iv_size = iv_size;
  	ctx->iv = kmalloc(iv_size + TLS_CIPHER_AES_GCM_128_SALT_SIZE, GFP_KERNEL);
  	if (!ctx->iv) {
  		rc = -ENOMEM;
  		goto free_priv;
  	}
  	memcpy(ctx->iv, gcm_128_info->salt, TLS_CIPHER_AES_GCM_128_SALT_SIZE);
  	memcpy(ctx->iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE, iv, iv_size);
  	ctx->rec_seq_size = rec_seq_size;
  	ctx->rec_seq = kmalloc(rec_seq_size, GFP_KERNEL);
  	if (!ctx->rec_seq) {
  		rc = -ENOMEM;
  		goto free_iv;
  	}
  	memcpy(ctx->rec_seq, rec_seq, rec_seq_size);
  
  	sg_init_table(sw_ctx->sg_encrypted_data,
  		      ARRAY_SIZE(sw_ctx->sg_encrypted_data));
  	sg_init_table(sw_ctx->sg_plaintext_data,
  		      ARRAY_SIZE(sw_ctx->sg_plaintext_data));
  
  	sg_init_table(sw_ctx->sg_aead_in, 2);
  	sg_set_buf(&sw_ctx->sg_aead_in[0], sw_ctx->aad_space,
  		   sizeof(sw_ctx->aad_space));
  	sg_unmark_end(&sw_ctx->sg_aead_in[1]);
  	sg_chain(sw_ctx->sg_aead_in, 2, sw_ctx->sg_plaintext_data);
  	sg_init_table(sw_ctx->sg_aead_out, 2);
  	sg_set_buf(&sw_ctx->sg_aead_out[0], sw_ctx->aad_space,
  		   sizeof(sw_ctx->aad_space));
  	sg_unmark_end(&sw_ctx->sg_aead_out[1]);
  	sg_chain(sw_ctx->sg_aead_out, 2, sw_ctx->sg_encrypted_data);
  
  	if (!sw_ctx->aead_send) {
  		sw_ctx->aead_send = crypto_alloc_aead("gcm(aes)", 0, 0);
  		if (IS_ERR(sw_ctx->aead_send)) {
  			rc = PTR_ERR(sw_ctx->aead_send);
  			sw_ctx->aead_send = NULL;
  			goto free_rec_seq;
  		}
  	}
  
  	ctx->push_pending_record = tls_sw_push_pending_record;
  
  	rc = crypto_aead_setkey(sw_ctx->aead_send, gcm_128_info->key,
  				TLS_CIPHER_AES_GCM_128_KEY_SIZE);
  	if (rc)
  		goto free_aead;
  
  	rc = crypto_aead_setauthsize(sw_ctx->aead_send, ctx->tag_size);
  	if (!rc)
  		return 0;
  
  free_aead:
  	crypto_free_aead(sw_ctx->aead_send);
  	sw_ctx->aead_send = NULL;
  free_rec_seq:
  	kfree(ctx->rec_seq);
  	ctx->rec_seq = NULL;
  free_iv:
  	kfree(ctx->iv);
  	ctx->iv = NULL;
  free_priv:
  	kfree(ctx->priv_ctx);
  	ctx->priv_ctx = NULL;
  out:
  	return rc;
  }
  