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Date: Fri, 23 Mar 2018 13:21:59 -0700
From: Shannon Nelson <shannon.nelson@...cle.com>
To: Saeed Mahameed <saeedm@...lanox.com>,
"David S. Miller" <davem@...emloft.net>
Cc: netdev@...r.kernel.org, Dave Watson <davejwatson@...com>,
Boris Pismenny <borisp@...lanox.com>,
Ilya Lesokhin <ilyal@...lanox.com>,
Aviad Yehezkel <aviadye@...lanox.com>
Subject: Re: [PATCH V3 net-next 06/14] net/tls: Add generic NIC offload
infrastructure
On 3/22/2018 3:33 PM, Saeed Mahameed wrote:
> From: Ilya Lesokhin <ilyal@...lanox.com>
>
> This patch adds a generic infrastructure to offload TLS crypto to a
> network devices. It enables the kernel TLS socket to skip encryption
s/devices/device/
> and authentication operations on the transmit side of the data path.
> Leaving those computationally expensive operations to the NIC.
>
> The NIC offload infrastructure builds TLS records and pushes them to
> the TCP layer just like the SW KTLS implementation and using the same API.
> TCP segmentation is mostly unaffected. Currently the only exception is
> that we prevent mixed SKBs where only part of the payload requires
> offload. In the future we are likely to add a similar restriction
> following a change cipher spec record.
>
> The notable differences between SW KTLS and NIC offloaded TLS
> implementations are as follows:
> 1. The offloaded implementation builds "plaintext TLS record", those
> records contain plaintext instead of ciphertext and place holder bytes
> instead of authentication tags.
> 2. The offloaded implementation maintains a mapping from TCP sequence
> number to TLS records. Thus given a TCP SKB sent from a NIC offloaded
> TLS socket, we can use the tls NIC offload infrastructure to obtain
> enough context to encrypt the payload of the SKB.
> A TLS record is released when the last byte of the record is ack'ed,
> this is done through the new icsk_clean_acked callback.
>
> The infrastructure should be extendable to support various NIC offload
> implementations. However it is currently written with the
> implementation below in mind:
> The NIC assumes that packets from each offloaded stream are sent as
> plaintext and in-order. It keeps track of the TLS records in the TCP
> stream. When a packet marked for offload is transmitted, the NIC
> encrypts the payload in-place and puts authentication tags in the
> relevant place holders.
>
> The responsibility for handling out-of-order packets (i.e. TCP
> retransmission, qdisc drops) falls on the netdev driver.
>
> The netdev driver keeps track of the expected TCP SN from the NIC's
> perspective. If the next packet to transmit matches the expected TCP
> SN, the driver advances the expected TCP SN, and transmits the packet
> with TLS offload indication.
>
> If the next packet to transmit does not match the expected TCP SN. The
> driver calls the TLS layer to obtain the TLS record that includes the
> TCP of the packet for transmission. Using this TLS record, the driver
> posts a work entry on the transmit queue to reconstruct the NIC TLS
> state required for the offload of the out-of-order packet. It updates
> the expected TCP SN accordingly and transmit the now in-order packet.
s/transmit/transmits/
> The same queue is used for packet transmission and TLS context
> reconstruction to avoid the need for flushing the transmit queue before
> issuing the context reconstruction request.
>
> Signed-off-by: Ilya Lesokhin <ilyal@...lanox.com>
> Signed-off-by: Boris Pismenny <borisp@...lanox.com>
> Signed-off-by: Aviad Yehezkel <aviadye@...lanox.com>
> Signed-off-by: Saeed Mahameed <saeedm@...lanox.com>
> ---
> include/net/tls.h | 73 +++-
> net/tls/Kconfig | 10 +
> net/tls/Makefile | 2 +
> net/tls/tls_device.c | 756 ++++++++++++++++++++++++++++++++++++++++++
> net/tls/tls_device_fallback.c | 412 +++++++++++++++++++++++
> net/tls/tls_main.c | 33 +-
> 6 files changed, 1279 insertions(+), 7 deletions(-)
> create mode 100644 net/tls/tls_device.c
> create mode 100644 net/tls/tls_device_fallback.c
>
> diff --git a/include/net/tls.h b/include/net/tls.h
> index 4913430ab807..4f6a6f98d62b 100644
> --- a/include/net/tls.h
> +++ b/include/net/tls.h
> @@ -77,6 +77,37 @@ struct tls_sw_context {
> struct scatterlist sg_aead_out[2];
> };
>
> +struct tls_record_info {
> + struct list_head list;
> + u32 end_seq;
> + int len;
> + int num_frags;
> + skb_frag_t frags[MAX_SKB_FRAGS];
> +};
> +
> +struct tls_offload_context {
> + struct crypto_aead *aead_send;
> + spinlock_t lock; /* protects records list */
> + struct list_head records_list;
> + struct tls_record_info *open_record;
> + struct tls_record_info *retransmit_hint;
> + u64 hint_record_sn;
> + u64 unacked_record_sn;
> +
> + struct scatterlist sg_tx_data[MAX_SKB_FRAGS];
> + void (*sk_destruct)(struct sock *sk);
> + u8 driver_state[];
> + /* The TLS layer reserves room for driver specific state
> + * Currently the belief is that there is not enough
> + * driver specific state to justify another layer of indirection
> + */
> +#define TLS_DRIVER_STATE_SIZE (max_t(size_t, 8, sizeof(void *)))
> +};
> +
> +#define TLS_OFFLOAD_CONTEXT_SIZE \
> + (ALIGN(sizeof(struct tls_offload_context), sizeof(void *)) + \
> + TLS_DRIVER_STATE_SIZE)
> +
> enum {
> TLS_PENDING_CLOSED_RECORD
> };
> @@ -87,6 +118,10 @@ struct tls_context {
> struct tls12_crypto_info_aes_gcm_128 crypto_send_aes_gcm_128;
> };
>
> + struct list_head list;
> + struct net_device *netdev;
> + refcount_t refcount;
> +
> void *priv_ctx;
>
> u8 tx_conf:2;
> @@ -131,9 +166,28 @@ int tls_sw_sendpage(struct sock *sk, struct page *page,
> void tls_sw_close(struct sock *sk, long timeout);
> void tls_sw_free_tx_resources(struct sock *sk);
>
> -void tls_sk_destruct(struct sock *sk, struct tls_context *ctx);
> -void tls_icsk_clean_acked(struct sock *sk);
> +int tls_set_device_offload(struct sock *sk, struct tls_context *ctx);
> +int tls_device_sendmsg(struct sock *sk, struct msghdr *msg, size_t size);
> +int tls_device_sendpage(struct sock *sk, struct page *page,
> + int offset, size_t size, int flags);
> +void tls_device_sk_destruct(struct sock *sk);
> +void tls_device_init(void);
> +void tls_device_cleanup(void);
> +
> +struct tls_record_info *tls_get_record(struct tls_offload_context *context,
> + u32 seq, u64 *p_record_sn);
> +
> +static inline bool tls_record_is_start_marker(struct tls_record_info *rec)
> +{
> + return rec->len == 0;
> +}
> +
> +static inline u32 tls_record_start_seq(struct tls_record_info *rec)
> +{
> + return rec->end_seq - rec->len;
> +}
>
> +void tls_sk_destruct(struct sock *sk, struct tls_context *ctx);
> int tls_push_sg(struct sock *sk, struct tls_context *ctx,
> struct scatterlist *sg, u16 first_offset,
> int flags);
> @@ -170,6 +224,13 @@ static inline bool tls_is_pending_open_record(struct tls_context *tls_ctx)
> return tls_ctx->pending_open_record_frags;
> }
>
> +static inline bool tls_is_sk_tx_device_offloaded(struct sock *sk)
> +{
> + return sk_fullsock(sk) &&
> + /* matches smp_store_release in tls_set_device_offload */
> + smp_load_acquire(&sk->sk_destruct) == &tls_device_sk_destruct;
> +}
> +
> static inline void tls_err_abort(struct sock *sk)
> {
> sk->sk_err = EBADMSG;
> @@ -257,4 +318,12 @@ static inline struct tls_offload_context *tls_offload_ctx(
> int tls_proccess_cmsg(struct sock *sk, struct msghdr *msg,
> unsigned char *record_type);
>
> +struct sk_buff *tls_validate_xmit_skb(struct sock *sk,
> + struct net_device *dev,
> + struct sk_buff *skb);
> +
> +int tls_sw_fallback_init(struct sock *sk,
> + struct tls_offload_context *offload_ctx,
> + struct tls_crypto_info *crypto_info);
> +
> #endif /* _TLS_OFFLOAD_H */
> diff --git a/net/tls/Kconfig b/net/tls/Kconfig
> index eb583038c67e..9d3ef820bb16 100644
> --- a/net/tls/Kconfig
> +++ b/net/tls/Kconfig
> @@ -13,3 +13,13 @@ config TLS
> encryption handling of the TLS protocol to be done in-kernel.
>
> If unsure, say N.
> +
> +config TLS_DEVICE
> + bool "Transport Layer Security HW offload"
> + depends on TLS
> + select SOCK_VALIDATE_XMIT
> + default n
> + ---help---
> + Enable kernel support for HW offload of the TLS protocol.
> +
> + If unsure, say N.
> diff --git a/net/tls/Makefile b/net/tls/Makefile
> index a930fd1c4f7b..4d6b728a67d0 100644
> --- a/net/tls/Makefile
> +++ b/net/tls/Makefile
> @@ -5,3 +5,5 @@
> obj-$(CONFIG_TLS) += tls.o
>
> tls-y := tls_main.o tls_sw.o
> +
> +tls-$(CONFIG_TLS_DEVICE) += tls_device.o tls_device_fallback.o
> diff --git a/net/tls/tls_device.c b/net/tls/tls_device.c
> new file mode 100644
> index 000000000000..34555ac0b959
> --- /dev/null
> +++ b/net/tls/tls_device.c
> @@ -0,0 +1,756 @@
> +/* Copyright (c) 2018, Mellanox Technologies All rights reserved.
Maybe add the appropriate SPDX tag to the top of this new file?
> + *
> + * 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 <net/tcp.h>
> +#include <net/inet_common.h>
> +#include <linux/highmem.h>
> +#include <linux/netdevice.h>
> +
> +#include <net/tls.h>
> +#include <crypto/aead.h>
> +
> +/* device_offload_lock is used to synchronize tls_dev_add
> + * against NETDEV_DOWN notifications.
> + */
> +static DECLARE_RWSEM(device_offload_lock);
> +
> +static void tls_device_gc_task(struct work_struct *work);
> +
> +static DECLARE_WORK(tls_device_gc_work, tls_device_gc_task);
> +static LIST_HEAD(tls_device_gc_list);
> +static LIST_HEAD(tls_device_list);
> +static DEFINE_SPINLOCK(tls_device_lock);
> +
> +static void tls_device_free_ctx(struct tls_context *ctx)
> +{
> + struct tls_offload_context *offlad_ctx = tls_offload_ctx(ctx);
> +
> + kfree(offlad_ctx);
Don't misspell a variable name, please either use something like
offload_ctx or shortened to olc.
> + kfree(ctx);
> +}
> +
> +static void tls_device_gc_task(struct work_struct *work)
> +{
> + struct tls_context *ctx, *tmp;
> + unsigned long flags;
> + LIST_HEAD(gc_list);
> +
> +
Drop the extra blank line
> + spin_lock_irqsave(&tls_device_lock, flags);
> + list_splice_init(&tls_device_gc_list, &gc_list);
> + spin_unlock_irqrestore(&tls_device_lock, flags);
> +
> + list_for_each_entry_safe(ctx, tmp, &gc_list, list) {
> + struct net_device *netdev = ctx->netdev;
> +
> + if (netdev) {
> + netdev->tlsdev_ops->tls_dev_del(netdev, ctx,
> + TLS_OFFLOAD_CTX_DIR_TX);
Perhaps it will be clear in later code, but are you guaranteed there are
good ops and function pointers here, or should there be a check like in
many API calls like this? Maybe
if (netdev) {
if (netdev->tlsdev_ops &&
netdev->tlsdev_ops->tls_dev_del)
> + dev_put(netdev);
> + }
> +
> + list_del(&ctx->list);
> + tls_device_free_ctx(ctx);
> + }
> +}
> +
> +static void tls_device_queue_ctx_destruction(struct tls_context *ctx)
> +{
> + unsigned long flags;
> +
> + spin_lock_irqsave(&tls_device_lock, flags);
> + list_move_tail(&ctx->list, &tls_device_gc_list);
> +
> + /* schedule_work inside the spinlock
> + * to make sure tls_device_down waits for that work.
> + */
> + schedule_work(&tls_device_gc_work);
> +
> + spin_unlock_irqrestore(&tls_device_lock, flags);
> +}
> +
> +/* We assume that the socket is already connected */
> +static struct net_device *get_netdev_for_sock(struct sock *sk)
> +{
> + struct inet_sock *inet = inet_sk(sk);
> + struct net_device *netdev = NULL;
This initialization is unnecessary;
> +
> + netdev = dev_get_by_index(sock_net(sk), inet->cork.fl.flowi_oif);
> +
> + return netdev;
> +}
> +
> +static void destroy_record(struct tls_record_info *record)
> +{
> + int nr_frags = record->num_frags;
> + skb_frag_t *frag;
> +
> + while (nr_frags-- > 0) {
> + frag = &record->frags[nr_frags];
> + __skb_frag_unref(frag);
> + }
> + kfree(record);
> +}
> +
> +static void delete_all_records(struct tls_offload_context *offload_ctx)
> +{
> + struct tls_record_info *info, *temp;
> +
> + list_for_each_entry_safe(info, temp, &offload_ctx->records_list, list) {
> + list_del(&info->list);
> + destroy_record(info);
> + }
> +
> + offload_ctx->retransmit_hint = NULL;
> +}
> +
> +static void tls_icsk_clean_acked(struct sock *sk, u32 acked_seq)
> +{
> + struct tls_context *tls_ctx = tls_get_ctx(sk);
> + struct tls_record_info *info, *temp;
> + struct tls_offload_context *ctx;
> + u64 deleted_records = 0;
> + unsigned long flags;
> +
> + if (!tls_ctx)
> + return;
> +
> + ctx = tls_offload_ctx(tls_ctx);
> +
> + spin_lock_irqsave(&ctx->lock, flags);
> + info = ctx->retransmit_hint;
> + if (info && !before(acked_seq, info->end_seq)) {
> + ctx->retransmit_hint = NULL;
> + list_del(&info->list);
> + destroy_record(info);
> + deleted_records++;
> + }
> +
> + list_for_each_entry_safe(info, temp, &ctx->records_list, list) {
> + if (before(acked_seq, info->end_seq))
> + break;
> + list_del(&info->list);
> +
> + destroy_record(info);
> + deleted_records++;
> + }
> +
> + ctx->unacked_record_sn += deleted_records;
> + spin_unlock_irqrestore(&ctx->lock, flags);
> +}
> +
> +/* At this point, there should be no references on this
> + * socket and no in-flight SKBs associated with this
> + * socket, so it is safe to free all the resources.
> + */
> +void tls_device_sk_destruct(struct sock *sk)
> +{
> + struct tls_context *tls_ctx = tls_get_ctx(sk);
> + struct tls_offload_context *ctx = tls_offload_ctx(tls_ctx);
> +
> + if (ctx->open_record)
> + destroy_record(ctx->open_record);
> +
> + delete_all_records(ctx);
> + crypto_free_aead(ctx->aead_send);
> + ctx->sk_destruct(sk);
> + static_branch_dec(&clean_acked_data_enabled);
> +
> + if (refcount_dec_and_test(&tls_ctx->refcount))
> + tls_device_queue_ctx_destruction(tls_ctx);
> +}
> +EXPORT_SYMBOL(tls_device_sk_destruct);
> +
> +static inline void tls_append_frag(struct tls_record_info *record,
I think Dave has already mentioned this, but you can drop all the
"inline" tags.
> + struct page_frag *pfrag,
> + int size)
> +{
> + skb_frag_t *frag;
> +
> + frag = &record->frags[record->num_frags - 1];
> + if (frag->page.p == pfrag->page &&
> + frag->page_offset + frag->size == pfrag->offset) {
> + frag->size += size;
> + } else {
> + ++frag;
Should this get checked against MAX_SKB_FRAGS to be sure we haven't gone
off the end of the array?
> + frag->page.p = pfrag->page;
> + frag->page_offset = pfrag->offset;
> + frag->size = size;
> + ++record->num_frags;
> + get_page(pfrag->page);
> + }
> +
> + pfrag->offset += size;
> + record->len += size;
> +}
> +
> +static inline int tls_push_record(struct sock *sk,
> + struct tls_context *ctx,
> + struct tls_offload_context *offload_ctx,
> + struct tls_record_info *record,
> + struct page_frag *pfrag,
> + int flags,
> + unsigned char record_type)
> +{
> + struct tcp_sock *tp = tcp_sk(sk);
> + struct page_frag dummy_tag_frag;
> + skb_frag_t *frag;
> + int i;
> +
> + /* fill prepand */
s/prepand/prepend/
> + frag = &record->frags[0];
> + tls_fill_prepend(ctx,
> + skb_frag_address(frag),
> + record->len - ctx->prepend_size,
> + record_type);
> +
> + /* HW doesn't care about the data in the tag, because it fills it. */
> + dummy_tag_frag.page = skb_frag_page(frag);
> + dummy_tag_frag.offset = 0;
> +
> + tls_append_frag(record, &dummy_tag_frag, ctx->tag_size);
> + record->end_seq = tp->write_seq + record->len;
> + spin_lock_irq(&offload_ctx->lock);
> + list_add_tail(&record->list, &offload_ctx->records_list);
> + spin_unlock_irq(&offload_ctx->lock);
> + offload_ctx->open_record = NULL;
> + set_bit(TLS_PENDING_CLOSED_RECORD, &ctx->flags);
> + tls_advance_record_sn(sk, ctx);
> +
> + for (i = 0; i < record->num_frags; i++) {
> + frag = &record->frags[i];
> + sg_unmark_end(&offload_ctx->sg_tx_data[i]);
> + sg_set_page(&offload_ctx->sg_tx_data[i], skb_frag_page(frag),
> + frag->size, frag->page_offset);
> + sk_mem_charge(sk, frag->size);
> + get_page(skb_frag_page(frag));
> + }
> + sg_mark_end(&offload_ctx->sg_tx_data[record->num_frags - 1]);
> +
> + /* all ready, send */
> + return tls_push_sg(sk, ctx, offload_ctx->sg_tx_data, 0, flags);
> +}
> +
> +static inline int tls_create_new_record(struct tls_offload_context *offload_ctx,
> + struct page_frag *pfrag,
> + size_t prepend_size)
> +{
> + struct tls_record_info *record;
> + skb_frag_t *frag;
> +
> + record = kmalloc(sizeof(*record), GFP_KERNEL);
> + if (!record)
> + return -ENOMEM;
> +
> + frag = &record->frags[0];
> + __skb_frag_set_page(frag, pfrag->page);
> + frag->page_offset = pfrag->offset;
> + skb_frag_size_set(frag, prepend_size);
> +
> + get_page(pfrag->page);
> + pfrag->offset += prepend_size;
> +
> + record->num_frags = 1;
> + record->len = prepend_size;
> + offload_ctx->open_record = record;
> + return 0;
> +}
> +
> +static inline int tls_do_allocation(struct sock *sk,
> + struct tls_offload_context *offload_ctx,
> + struct page_frag *pfrag,
> + size_t prepend_size)
> +{
> + int ret;
> +
> + if (!offload_ctx->open_record) {
> + if (unlikely(!skb_page_frag_refill(prepend_size, pfrag,
> + sk->sk_allocation))) {
> + sk->sk_prot->enter_memory_pressure(sk);
> + sk_stream_moderate_sndbuf(sk);
> + return -ENOMEM;
> + }
> +
> + ret = tls_create_new_record(offload_ctx, pfrag, prepend_size);
> + if (ret)
> + return ret;
> +
> + if (pfrag->size > pfrag->offset)
> + return 0;
> + }
> +
> + if (!sk_page_frag_refill(sk, pfrag))
> + return -ENOMEM;
If a new record was created and then this fails, do you need to free the
new record?
> +
> + return 0;
> +}
> +
> +static int tls_push_data(struct sock *sk,
> + struct iov_iter *msg_iter,
> + size_t size, int flags,
> + unsigned char record_type)
> +{
> + struct tls_context *tls_ctx = tls_get_ctx(sk);
> + struct tls_offload_context *ctx = tls_offload_ctx(tls_ctx);
> + int tls_push_record_flags = flags | MSG_SENDPAGE_NOTLAST;
> + int more = flags & (MSG_SENDPAGE_NOTLAST | MSG_MORE);
> + struct tls_record_info *record = ctx->open_record;
> + struct page_frag *pfrag;
> + size_t orig_size = size;
> + u32 max_open_record_len;
> + int copy, rc = 0;
> + bool done = false;
> + long timeo;
> +
> + if (flags &
> + ~(MSG_MORE | MSG_DONTWAIT | MSG_NOSIGNAL | MSG_SENDPAGE_NOTLAST))
> + return -ENOTSUPP;
> +
> + if (sk->sk_err)
> + return -sk->sk_err;
> +
> + timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
> + rc = tls_complete_pending_work(sk, tls_ctx, flags, &timeo);
> + if (rc < 0)
> + return rc;
> +
> + pfrag = sk_page_frag(sk);
> +
> + /* TLS_TLS_HEADER_SIZE is not counted as part of the TLS record, and
s/TLS_TLS_HEADER_SIZE/TLS_HEADER_SIZE/
> + * we need to leave room for an authentication tag.
> + */
> + max_open_record_len = TLS_MAX_PAYLOAD_SIZE +
> + tls_ctx->prepend_size;
> + do {
> + if (tls_do_allocation(sk, ctx, pfrag,
> + tls_ctx->prepend_size)) {
So you do this block if tls_do_allocation() fails, right? This is not
clear to the drive-by reader, it looks a bit like the opposite. I'd
suggest something a little more obvious like
rc = tls_do_allocation(sk, ctx, pfrag,
tls_ctx->prepend_size)
if (rc) {
> + rc = sk_stream_wait_memory(sk, &timeo);
> + if (!rc)
> + continue;
> +
> + record = ctx->open_record;
> + if (!record)
> + break;
> +handle_error:
> + if (record_type != TLS_RECORD_TYPE_DATA) {
> + /* avoid sending partial
> + * record with type !=
> + * application_data
> + */
> + size = orig_size;
> + destroy_record(record);
> + ctx->open_record = NULL;
> + } else if (record->len > tls_ctx->prepend_size) {
> + goto last_record;
> + }
> +
> + break;
> + }
> +
> + record = ctx->open_record;
> + copy = min_t(size_t, size, (pfrag->size - pfrag->offset));
> + copy = min_t(size_t, copy, (max_open_record_len - record->len));
> +
> + if (copy_from_iter_nocache(page_address(pfrag->page) +
> + pfrag->offset,
> + copy, msg_iter) != copy) {
> + rc = -EFAULT;
> + goto handle_error;
This jumping around begins to feel a bit convoluted - is there another
way you can handle this?
> + }
> + tls_append_frag(record, pfrag, copy);
> +
> + size -= copy;
> + if (!size) {
> +last_record:
> + tls_push_record_flags = flags;
> + if (more) {
> + tls_ctx->pending_open_record_frags =
> + record->num_frags;
> + break;
> + }
> +
> + done = true;
> + }
> +
> + if ((done) || record->len >= max_open_record_len ||
parens around (done) are unnecessary
> + (record->num_frags >= MAX_SKB_FRAGS - 1)) {
> + rc = tls_push_record(sk,
> + tls_ctx,
> + ctx,
> + record,
> + pfrag,
> + tls_push_record_flags,
> + record_type);
> + if (rc < 0)
> + break;
> + }
> + } while (!done);
> +
> + if (orig_size - size > 0)
> + rc = orig_size - size;
If there was an error returned from tls_push_record(), will this
overwrite the error rc code?
> +
> + return rc;
> +}
> +
> +int tls_device_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
> +{
> + unsigned char record_type = TLS_RECORD_TYPE_DATA;
> + int rc = 0;
rc initialization unnecessary
> +
> + lock_sock(sk);
> +
> + if (unlikely(msg->msg_controllen)) {
> + rc = tls_proccess_cmsg(sk, msg, &record_type);
> + if (rc)
> + goto out;
> + }
> +
> + rc = tls_push_data(sk, &msg->msg_iter, size,
> + msg->msg_flags, record_type);
> +
> +out:
> + release_sock(sk);
> + return rc;
> +}
> +
> +int tls_device_sendpage(struct sock *sk, struct page *page,
> + int offset, size_t size, int flags)
> +{
> + struct iov_iter msg_iter;
> + char *kaddr = kmap(page);
> + struct kvec iov;
> + int rc = 0;
rc initialization unnecessary
> +
> + if (flags & MSG_SENDPAGE_NOTLAST)
> + flags |= MSG_MORE;
> +
> + lock_sock(sk);
> +
> + if (flags & MSG_OOB) {
> + rc = -ENOTSUPP;
> + goto out;
> + }
> +
> + iov.iov_base = kaddr + offset;
> + iov.iov_len = size;
> + iov_iter_kvec(&msg_iter, WRITE | ITER_KVEC, &iov, 1, size);
> + rc = tls_push_data(sk, &msg_iter, size,
> + flags, TLS_RECORD_TYPE_DATA);
> + kunmap(page);
> +
> +out:
> + release_sock(sk);
> + return rc;
> +}
> +
> +struct tls_record_info *tls_get_record(struct tls_offload_context *context,
> + u32 seq, u64 *p_record_sn)
> +{
> + u64 record_sn = context->hint_record_sn;
> + struct tls_record_info *info;
> +
> + info = context->retransmit_hint;
> + if (!info ||
> + before(seq, info->end_seq - info->len)) {
> + /* if retransmit_hint is irrelevant start
> + * from the begging of the list
s/begging/beginning/
> + */
> + info = list_first_entry(&context->records_list,
> + struct tls_record_info, list);
> + record_sn = context->unacked_record_sn;
> + }
> +
> + list_for_each_entry_from(info, &context->records_list, list) {
> + if (before(seq, info->end_seq)) {
> + if (!context->retransmit_hint ||
> + after(info->end_seq,
> + context->retransmit_hint->end_seq)) {
> + context->hint_record_sn = record_sn;
> + context->retransmit_hint = info;
> + }
> + *p_record_sn = record_sn;
> + return info;
> + }
> + record_sn++;
> + }
> +
> + return NULL;
> +}
> +EXPORT_SYMBOL(tls_get_record);
> +
> +static int tls_device_push_pending_record(struct sock *sk, int flags)
> +{
> + struct iov_iter msg_iter;
> +
> + iov_iter_kvec(&msg_iter, WRITE | ITER_KVEC, NULL, 0, 0);
> + return tls_push_data(sk, &msg_iter, 0, flags, TLS_RECORD_TYPE_DATA);
> +}
> +
> +int tls_set_device_offload(struct sock *sk, struct tls_context *ctx)
> +{
> + u16 nonece_size, tag_size, iv_size, rec_seq_size;
s/nonece/nonce/
> + struct tls_record_info *start_marker_record;
> + struct tls_offload_context *offload_ctx;
> + struct tls_crypto_info *crypto_info;
> + struct net_device *netdev;
> + char *iv, *rec_seq;
> + struct sk_buff *skb;
> + int rc = -EINVAL;
> + __be64 rcd_sn;
> +
> + if (!ctx)
> + goto out;
> +
> + if (ctx->priv_ctx) {
> + rc = -EEXIST;
> + goto out;
> + }
> +
> + start_marker_record = kmalloc(sizeof(*start_marker_record), GFP_KERNEL);
> + if (!start_marker_record) {
> + rc = -ENOMEM;
> + goto out;
> + }
> +
> + offload_ctx = kzalloc(TLS_OFFLOAD_CONTEXT_SIZE, GFP_KERNEL);
> + if (!offload_ctx) {
> + rc = -ENOMEM;
> + goto free_marker_record;
> + }
> +
> + crypto_info = &ctx->crypto_send;
> + switch (crypto_info->cipher_type) {
> + case TLS_CIPHER_AES_GCM_128: {
> + nonece_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;
> + break;
> + }
{}'s are unnecessary here
> + default:
> + rc = -EINVAL;
> + goto free_offload_ctx;
> + }
> +
> + ctx->prepend_size = TLS_HEADER_SIZE + nonece_size;
> + ctx->tag_size = 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_offload_ctx;
> + }
> +
> + 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);
> +
> + rc = tls_sw_fallback_init(sk, offload_ctx, crypto_info);
> + if (rc)
> + goto free_rec_seq;
> +
> + /* start at rec_seq - 1 to account for the start marker record */
> + memcpy(&rcd_sn, ctx->rec_seq, sizeof(rcd_sn));
> + offload_ctx->unacked_record_sn = be64_to_cpu(rcd_sn) - 1;
> +
> + start_marker_record->end_seq = tcp_sk(sk)->write_seq;
> + start_marker_record->len = 0;
> + start_marker_record->num_frags = 0;
> +
> + INIT_LIST_HEAD(&offload_ctx->records_list);
> + list_add_tail(&start_marker_record->list, &offload_ctx->records_list);
> + spin_lock_init(&offload_ctx->lock);
> +
> + static_branch_inc(&clean_acked_data_enabled);
> + inet_csk(sk)->icsk_clean_acked = &tls_icsk_clean_acked;
> + ctx->push_pending_record = tls_device_push_pending_record;
> + offload_ctx->sk_destruct = sk->sk_destruct;
> +
> + /* TLS offload is greatly simplified if we don't send
> + * SKBs where only part of the payload needs to be encrypted.
> + * So mark the last skb in the write queue as end of record.
> + */
> + skb = tcp_write_queue_tail(sk);
> + if (skb)
> + TCP_SKB_CB(skb)->eor = 1;
> +
> + refcount_set(&ctx->refcount, 1);
> +
> + /* We support starting offload on multiple sockets
> + * concurrently, so we only need a read lock here.
> + * This lock must preceed get_netdev_for_sock to prevent races between
> + * NETDEV_DOWN and setsockopt.
> + */
> + down_read(&device_offload_lock);
> + netdev = get_netdev_for_sock(sk);
> + if (!netdev) {
> + pr_err_ratelimited("%s: netdev not found\n", __func__);
> + rc = -EINVAL;
> + goto release_lock;
> + }
> +
> + if (!(netdev->features & NETIF_F_HW_TLS_TX)) {
> + rc = -ENOTSUPP;
> + goto release_netdev;
> + }
> +
> + /* Avoid offloading if the device is down
> + * We don't want to offload new flows after
> + * the NETDEV_DOWN event
> + */
> + if (!(netdev->flags & IFF_UP)) {
> + rc = -EINVAL;
> + goto release_netdev;
> + }
> +
> + ctx->priv_ctx = offload_ctx;
> + rc = netdev->tlsdev_ops->tls_dev_add(netdev, sk, TLS_OFFLOAD_CTX_DIR_TX,
Do you have a check somewhere that guarantees any netdev with
NETIF_F_HW_TLS_TX set actually has the tlsdev_ops defined so you can
call this without checking it?
> + &ctx->crypto_send,
> + tcp_sk(sk)->write_seq);
> + if (rc)
> + goto release_netdev;
> +
> + ctx->netdev = netdev;
> +
> + spin_lock_irq(&tls_device_lock);
> + list_add_tail(&ctx->list, &tls_device_list);
> + spin_unlock_irq(&tls_device_lock);
> +
> + sk->sk_validate_xmit_skb = tls_validate_xmit_skb;
> + /* following this assignment tls_is_sk_tx_device_offloaded
> + * will return true and the context might be accessed
> + * by the netdev's xmit function.
> + */
> + smp_store_release(&sk->sk_destruct,
> + &tls_device_sk_destruct);
> + up_read(&device_offload_lock);
> + goto out;
> +
> +release_netdev:
> + dev_put(netdev);
> +release_lock:
> + up_read(&device_offload_lock);
> + static_branch_dec(&clean_acked_data_enabled);
> + crypto_free_aead(offload_ctx->aead_send);
> +free_rec_seq:
> + kfree(ctx->rec_seq);
> +free_iv:
> + kfree(ctx->iv);
> +free_offload_ctx:
> + kfree(offload_ctx);
> + ctx->priv_ctx = NULL;
> +free_marker_record:
> + kfree(start_marker_record);
> +out:
> + return rc;
> +}
> +
> +static int tls_device_down(struct net_device *netdev)
> +{
> + struct tls_context *ctx, *tmp;
> + unsigned long flags;
> + LIST_HEAD(list);
> +
> + /* Request a write lock to block new offload attempts
> + */
single line comment
> + down_write(&device_offload_lock);
> +
> + spin_lock_irqsave(&tls_device_lock, flags);
> + list_for_each_entry_safe(ctx, tmp, &tls_device_list, list) {
> + if (ctx->netdev != netdev ||
> + !refcount_inc_not_zero(&ctx->refcount))
> + continue;
> +
> + list_move(&ctx->list, &list);
> + }
> + spin_unlock_irqrestore(&tls_device_lock, flags);
> +
> + list_for_each_entry_safe(ctx, tmp, &list, list) {
> + netdev->tlsdev_ops->tls_dev_del(netdev, ctx,
> + TLS_OFFLOAD_CTX_DIR_TX);
Are tlsdev_ops and tls_dev_del defined?
> + ctx->netdev = NULL;
> + dev_put(netdev);
> + list_del_init(&ctx->list);
> +
> + if (refcount_dec_and_test(&ctx->refcount))
> + tls_device_free_ctx(ctx);
> + }
> +
> + up_write(&device_offload_lock);
> +
> + flush_work(&tls_device_gc_work);
> +
> + return NOTIFY_DONE;
> +}
> +
> +static int tls_dev_event(struct notifier_block *this, unsigned long event,
> + void *ptr)
> +{
> + struct net_device *dev = netdev_notifier_info_to_dev(ptr);
> +
> + if (!(dev->features & NETIF_F_HW_TLS_TX))
> + return NOTIFY_DONE;
> +
> + switch (event) {
> + case NETDEV_REGISTER:
> + case NETDEV_FEAT_CHANGE:
> + return dev->tlsdev_ops ? NOTIFY_DONE : NOTIFY_BAD;
Okay, you've got a check for tlsdev_ops, but what about the function
pointers that are assumed to be good?
> + case NETDEV_DOWN:
> + return tls_device_down(dev);
> + }
> + return NOTIFY_DONE;
> +}
> +
> +static struct notifier_block tls_dev_notifier = {
> + .notifier_call = tls_dev_event,
> +};
> +
> +void __init tls_device_init(void)
> +{
> + register_netdevice_notifier(&tls_dev_notifier);
> +}
> +
> +void __exit tls_device_cleanup(void)
> +{
> + unregister_netdevice_notifier(&tls_dev_notifier);
> + flush_work(&tls_device_gc_work);
> +}
> diff --git a/net/tls/tls_device_fallback.c b/net/tls/tls_device_fallback.c
> new file mode 100644
> index 000000000000..f1302f479209
> --- /dev/null
> +++ b/net/tls/tls_device_fallback.c
> @@ -0,0 +1,412 @@
> +/* Copyright (c) 2018, Mellanox Technologies 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 <net/tls.h>
> +#include <crypto/aead.h>
> +#include <crypto/scatterwalk.h>
> +#include <net/ip6_checksum.h>
> +
> +static void chain_to_walk(struct scatterlist *sg, struct scatter_walk *walk)
> +{
> + struct scatterlist *src = walk->sg;
> + int diff = walk->offset - src->offset;
> +
> + sg_set_page(sg, sg_page(src),
> + src->length - diff, walk->offset);
> +
> + scatterwalk_crypto_chain(sg, sg_next(src), 0, 2);
> +}
> +
> +static int tls_enc_record(struct aead_request *aead_req,
> + struct crypto_aead *aead, char *aad, char *iv,
> + __be64 rcd_sn, struct scatter_walk *in,
> + struct scatter_walk *out, int *in_len)
> +{
> + unsigned char buf[TLS_HEADER_SIZE + TLS_CIPHER_AES_GCM_128_IV_SIZE];
> + struct scatterlist sg_in[3];
> + struct scatterlist sg_out[3];
> + u16 len;
> + int rc;
> +
> + len = min_t(int, *in_len, ARRAY_SIZE(buf));
> +
> + scatterwalk_copychunks(buf, in, len, 0);
> + scatterwalk_copychunks(buf, out, len, 1);
> +
> + *in_len -= len;
> + if (!*in_len)
> + return 0;
> +
> + scatterwalk_pagedone(in, 0, 1);
> + scatterwalk_pagedone(out, 1, 1);
> +
> + len = buf[4] | (buf[3] << 8);
> + len -= TLS_CIPHER_AES_GCM_128_IV_SIZE;
> +
> + tls_make_aad(aad, len - TLS_CIPHER_AES_GCM_128_TAG_SIZE,
> + (char *)&rcd_sn, sizeof(rcd_sn), buf[0]);
> +
> + memcpy(iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE, buf + TLS_HEADER_SIZE,
> + TLS_CIPHER_AES_GCM_128_IV_SIZE);
> +
> + sg_init_table(sg_in, ARRAY_SIZE(sg_in));
> + sg_init_table(sg_out, ARRAY_SIZE(sg_out));
> + sg_set_buf(sg_in, aad, TLS_AAD_SPACE_SIZE);
> + sg_set_buf(sg_out, aad, TLS_AAD_SPACE_SIZE);
> + chain_to_walk(sg_in + 1, in);
> + chain_to_walk(sg_out + 1, out);
> +
> + *in_len -= len;
> + if (*in_len < 0) {
> + *in_len += TLS_CIPHER_AES_GCM_128_TAG_SIZE;
> + if (*in_len < 0)
> + /* the input buffer doesn't contain the entire record.
s/./, so/
> + * trim len accordingly. The resulting authentication tag
> + * will contain garbage. but we don't care as we won't
s/garbage./garbage,/
> + * include any of it in the output skb
> + * Note that we assume the output buffer length
> + * is larger then input buffer length + tag size
> + */
> + len += *in_len;
Especially with that large of a comment, I think the if (*in_len < 0)
should be after and right next to the one line it protects.
> +
> + *in_len = 0;
> + }
> +
> + if (*in_len) {
> + scatterwalk_copychunks(NULL, in, len, 2);
> + scatterwalk_pagedone(in, 0, 1);
> + scatterwalk_copychunks(NULL, out, len, 2);
> + scatterwalk_pagedone(out, 1, 1);
> + }
> +
> + len -= TLS_CIPHER_AES_GCM_128_TAG_SIZE;
> + aead_request_set_crypt(aead_req, sg_in, sg_out, len, iv);
> +
> + rc = crypto_aead_encrypt(aead_req);
> +
> + return rc;
> +}
> +
> +static void tls_init_aead_request(struct aead_request *aead_req,
> + struct crypto_aead *aead)
> +{
> + aead_request_set_tfm(aead_req, aead);
> + aead_request_set_ad(aead_req, TLS_AAD_SPACE_SIZE);
> +}
> +
> +static struct aead_request *tls_alloc_aead_request(struct crypto_aead *aead,
> + gfp_t flags)
> +{
> + unsigned int req_size = sizeof(struct aead_request) +
> + crypto_aead_reqsize(aead);
> + struct aead_request *aead_req;
> +
> + aead_req = kzalloc(req_size, flags);
> + if (!aead_req)
> + return NULL;
> +
> + tls_init_aead_request(aead_req, aead);
> + return aead_req;
This could be turned around and shortened a little
aead_req = kzalloc(req_size, flags);
if (aead_req)
tls_init_aead_request(aead_req, aead);
return aead_req;
> +}
> +
> +static int tls_enc_records(struct aead_request *aead_req,
> + struct crypto_aead *aead, struct scatterlist *sg_in,
> + struct scatterlist *sg_out, char *aad, char *iv,
> + u64 rcd_sn, int len)
> +{
> + struct scatter_walk out, in;
> + int rc;
> +
> + scatterwalk_start(&in, sg_in);
> + scatterwalk_start(&out, sg_out);
> +
> + do {
> + rc = tls_enc_record(aead_req, aead, aad, iv,
> + cpu_to_be64(rcd_sn), &in, &out, &len);
> + rcd_sn++;
> +
> + } while (rc == 0 && len);
> +
> + scatterwalk_done(&in, 0, 0);
> + scatterwalk_done(&out, 1, 0);
> +
> + return rc;
> +}
> +
> +/* Can't use icsk->icsk_af_ops->send_check here because the ip addresses
> + * might have been changed by NAT.
> + */
> +static inline void update_chksum(struct sk_buff *skb, int headln)
> +{
> + struct tcphdr *th = tcp_hdr(skb);
> + int datalen = skb->len - headln;
> + const struct ipv6hdr *ipv6h;
> + const struct iphdr *iph;
> +
> + /* We only changed the payload so if we are using partial we don't
> + * need to update anything.
> + */
> + if (likely(skb->ip_summed == CHECKSUM_PARTIAL))
> + return;
> +
> + skb->ip_summed = CHECKSUM_PARTIAL;
> + skb->csum_start = skb_transport_header(skb) - skb->head;
> + skb->csum_offset = offsetof(struct tcphdr, check);
> +
> + if (skb->sk->sk_family == AF_INET6) {
> + ipv6h = ipv6_hdr(skb);
> + th->check = ~csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr,
> + datalen, IPPROTO_TCP, 0);
> + } else {
> + iph = ip_hdr(skb);
> + th->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr, datalen,
> + IPPROTO_TCP, 0);
> + }
> +}
> +
> +static void complete_skb(struct sk_buff *nskb, struct sk_buff *skb, int headln)
> +{
> + skb_copy_header(nskb, skb);
> +
> + skb_put(nskb, skb->len);
> + memcpy(nskb->data, skb->data, headln);
> + update_chksum(nskb, headln);
> +
> + nskb->destructor = skb->destructor;
> + nskb->sk = skb->sk;
> + skb->destructor = NULL;
> + skb->sk = NULL;
> + refcount_add(nskb->truesize - skb->truesize,
> + &nskb->sk->sk_wmem_alloc);
> +}
> +
> +/* This function may be called after the user socket is already
> + * closed so make sure we don't use anything freed during
> + * tls_sk_proto_close here
> + */
> +static struct sk_buff *tls_sw_fallback(struct sock *sk, struct sk_buff *skb)
> +{
> + int tcp_header_size = tcp_hdrlen(skb);
> + int tcp_payload_offset = skb_transport_offset(skb) + tcp_header_size;
> + int payload_len = skb->len - tcp_payload_offset;
> + struct tls_context *tls_ctx = tls_get_ctx(sk);
> + struct tls_offload_context *ctx = tls_offload_ctx(tls_ctx);
> + int remaining, buf_len, resync_sgs, rc, i = 0;
> + void *buf, *dummy_buf, *iv, *aad;
> + struct scatterlist *sg_in, sg_out[3];
> + u32 tcp_seq = ntohl(tcp_hdr(skb)->seq);
> + struct aead_request *aead_req;
> + struct sk_buff *nskb = NULL;
> + struct tls_record_info *record;
> + unsigned long flags;
> + s32 sync_size;
> + u64 rcd_sn;
> +
> + /* worst case is:
> + * MAX_SKB_FRAGS in tls_record_info
> + * MAX_SKB_FRAGS + 1 in SKB head and frags.
> + */
> + int sg_in_max_elements = 2 * MAX_SKB_FRAGS + 1;
> +
> + if (!payload_len)
> + return skb;
> +
> + sg_in = kmalloc_array(sg_in_max_elements, sizeof(*sg_in), GFP_ATOMIC);
> + if (!sg_in)
> + goto free_orig;
> +
> + sg_init_table(sg_in, sg_in_max_elements);
> + sg_init_table(sg_out, ARRAY_SIZE(sg_out));
> +
> + spin_lock_irqsave(&ctx->lock, flags);
> + record = tls_get_record(ctx, tcp_seq, &rcd_sn);
> + if (!record) {
> + spin_unlock_irqrestore(&ctx->lock, flags);
> + WARN(1, "Record not found for seq %u\n", tcp_seq);
> + goto free_sg;
> + }
> +
> + sync_size = tcp_seq - tls_record_start_seq(record);
> + if (sync_size < 0) {
> + int is_start_marker = tls_record_is_start_marker(record);
> +
> + spin_unlock_irqrestore(&ctx->lock, flags);
> + if (!is_start_marker)
> + /* This should only occur if the relevant record was
> + * already acked. In that case it should be ok
> + * to drop the packet and avoid retransmission.
> + *
> + * There is a corner case where the packet contains
> + * both an acked and a non-acked record.
> + * We currently don't handle that case and rely
> + * on TCP to retranmit a packet that doesn't contain
> + * already acked payload.
> + */
> + goto free_orig;
Again, let's keep the "if ..." closer to the one line being protected.
> +
> + if (payload_len > -sync_size) {
> + WARN(1, "Fallback of partially offloaded packets is not supported\n");
> + goto free_sg;
> + } else {
> + return skb;
> + }
> + }
> +
> + remaining = sync_size;
It would be a bit clearer, and more future safe, to set i=0 here rather
than rely on the initialization way back at the top of the function. In
fact, why not use a normal for-loop?
for (i = 0; remaining > 0; i++)
> + while (remaining > 0) {
> + skb_frag_t *frag = &record->frags[i];
> +
> + __skb_frag_ref(frag);
> + sg_set_page(sg_in + i, skb_frag_page(frag),
> + skb_frag_size(frag), frag->page_offset);
> +
> + remaining -= skb_frag_size(frag);
> +
> + if (remaining < 0)
> + sg_in[i].length += remaining;
> +
> + i++;
> + }
> + spin_unlock_irqrestore(&ctx->lock, flags);
> + resync_sgs = i;
> +
> + aead_req = tls_alloc_aead_request(ctx->aead_send, GFP_ATOMIC);
> + if (!aead_req)
> + goto put_sg;
> +
> + buf_len = TLS_CIPHER_AES_GCM_128_SALT_SIZE +
> + TLS_CIPHER_AES_GCM_128_IV_SIZE +
> + TLS_AAD_SPACE_SIZE +
> + sync_size +
> + tls_ctx->tag_size;
> + buf = kmalloc(buf_len, GFP_ATOMIC);
> + if (!buf)
> + goto free_req;
> +
> + nskb = alloc_skb(skb_headroom(skb) + skb->len, GFP_ATOMIC);
> + if (!nskb)
> + goto free_buf;
> +
> + skb_reserve(nskb, skb_headroom(skb));
> +
> + iv = buf;
> +
> + memcpy(iv, tls_ctx->crypto_send_aes_gcm_128.salt,
> + TLS_CIPHER_AES_GCM_128_SALT_SIZE);
> + aad = buf + TLS_CIPHER_AES_GCM_128_SALT_SIZE +
> + TLS_CIPHER_AES_GCM_128_IV_SIZE;
> + dummy_buf = aad + TLS_AAD_SPACE_SIZE;
> +
> + sg_set_buf(&sg_out[0], dummy_buf, sync_size);
> + sg_set_buf(&sg_out[1], nskb->data + tcp_payload_offset,
> + payload_len);
> + /* Add room for authentication tag produced by crypto */
> + dummy_buf += sync_size;
> + sg_set_buf(&sg_out[2], dummy_buf, tls_ctx->tag_size);
> + rc = skb_to_sgvec(skb, &sg_in[i], tcp_payload_offset,
> + payload_len);
> + if (rc < 0)
> + goto free_nskb;
> +
> + rc = tls_enc_records(aead_req, ctx->aead_send, sg_in, sg_out, aad, iv,
> + rcd_sn, sync_size + payload_len);
> + if (rc < 0)
> + goto free_nskb;
> +
> + complete_skb(nskb, skb, tcp_payload_offset);
> +
> + /* validate_xmit_skb_list assumes that if the skb wasn't segmented
> + * nskb->prev will point to the skb itself
> + */
> + nskb->prev = nskb;
> +free_buf:
> + kfree(buf);
> +free_req:
> + kfree(aead_req);
> +put_sg:
> + for (i = 0; i < resync_sgs; i++)
> + put_page(sg_page(&sg_in[i]));
> +free_sg:
> + kfree(sg_in);
> +free_orig:
> + kfree_skb(skb);
> + return nskb;
> +
> +free_nskb:
> + kfree_skb(nskb);
> + nskb = NULL;
> + goto free_buf;
> +}
> +
> +struct sk_buff *tls_validate_xmit_skb(struct sock *sk,
> + struct net_device *dev,
> + struct sk_buff *skb)
> +{
> + if (dev == tls_get_ctx(sk)->netdev)
> + return skb;
> +
> + return tls_sw_fallback(sk, skb);
> +}
> +
> +int tls_sw_fallback_init(struct sock *sk,
> + struct tls_offload_context *offload_ctx,
> + struct tls_crypto_info *crypto_info)
> +{
> + const u8 *key;
> + int rc;
> +
> + offload_ctx->aead_send =
> + crypto_alloc_aead("gcm(aes)", 0, CRYPTO_ALG_ASYNC);
> + if (IS_ERR(offload_ctx->aead_send)) {
> + rc = PTR_ERR(offload_ctx->aead_send);
> + pr_err_ratelimited("crypto_alloc_aead failed rc=%d\n", rc);
> + offload_ctx->aead_send = NULL;
> + goto err_out;
> + }
> +
> + key = ((struct tls12_crypto_info_aes_gcm_128 *)crypto_info)->key;
> +
> + rc = crypto_aead_setkey(offload_ctx->aead_send, key,
> + TLS_CIPHER_AES_GCM_128_KEY_SIZE);
> + if (rc)
> + goto free_aead;
> +
> + rc = crypto_aead_setauthsize(offload_ctx->aead_send,
> + TLS_CIPHER_AES_GCM_128_TAG_SIZE);
> + if (rc)
> + goto free_aead;
> +
> + return 0;
> +free_aead:
> + crypto_free_aead(offload_ctx->aead_send);
> +err_out:
> + return rc;
> +}
> diff --git a/net/tls/tls_main.c b/net/tls/tls_main.c
> index d824d548447e..e0dface33017 100644
> --- a/net/tls/tls_main.c
> +++ b/net/tls/tls_main.c
> @@ -54,6 +54,9 @@ enum {
> enum {
> TLS_BASE_TX,
> TLS_SW_TX,
> +#ifdef CONFIG_TLS_DEVICE
> + TLS_HW_TX,
> +#endif
> TLS_NUM_CONFIG,
> };
>
> @@ -416,11 +419,19 @@ static int do_tls_setsockopt_tx(struct sock *sk, char __user *optval,
> goto err_crypto_info;
> }
>
> - /* currently SW is default, we will have ethtool in future */
> - rc = tls_set_sw_offload(sk, ctx);
> - tx_conf = TLS_SW_TX;
> - if (rc)
> - goto err_crypto_info;
> +#ifdef CONFIG_TLS_DEVICE
> + rc = tls_set_device_offload(sk, ctx);
> + tx_conf = TLS_HW_TX;
> + if (rc) {
> +#else
> + {
> +#endif
> + /* if HW offload fails fallback to SW */
> + rc = tls_set_sw_offload(sk, ctx);
> + tx_conf = TLS_SW_TX;
> + if (rc)
> + goto err_crypto_info;
> + }
>
> ctx->tx_conf = tx_conf;
> update_sk_prot(sk, ctx);
> @@ -473,6 +484,12 @@ static void build_protos(struct proto *prot, struct proto *base)
> prot[TLS_SW_TX] = prot[TLS_BASE_TX];
> prot[TLS_SW_TX].sendmsg = tls_sw_sendmsg;
> prot[TLS_SW_TX].sendpage = tls_sw_sendpage;
> +
> +#ifdef CONFIG_TLS_DEVICE
> + prot[TLS_HW_TX] = prot[TLS_SW_TX];
> + prot[TLS_HW_TX].sendmsg = tls_device_sendmsg;
> + prot[TLS_HW_TX].sendpage = tls_device_sendpage;
> +#endif
> }
>
> static int tls_init(struct sock *sk)
> @@ -531,6 +548,9 @@ static int __init tls_register(void)
> {
> build_protos(tls_prots[TLSV4], &tcp_prot);
>
> +#ifdef CONFIG_TLS_DEVICE
> + tls_device_init();
> +#endif
> tcp_register_ulp(&tcp_tls_ulp_ops);
>
> return 0;
> @@ -539,6 +559,9 @@ static int __init tls_register(void)
> static void __exit tls_unregister(void)
> {
> tcp_unregister_ulp(&tcp_tls_ulp_ops);
> +#ifdef CONFIG_TLS_DEVICE
> + tls_device_cleanup();
> +#endif
> }
>
> module_init(tls_register);
>
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