| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <21dfaf9c-2910-d5d3-d75a-c749f717cee1@mellanox.com>
Date: Mon, 26 Mar 2018 10:10:14 +0300
From: Boris Pismenny <borisp@...lanox.com>
To: Shannon Nelson <shannon.nelson@...cle.com>,
Saeed Mahameed <saeedm@...lanox.com>,
"David S. Miller" <davem@...emloft.net>
Cc: netdev@...r.kernel.org, Dave Watson <davejwatson@...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
Hi Shannon,
On 3/23/2018 11:21 PM, Shannon Nelson wrote:
> 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?
>
Let's do it in a single patch for all net/tls/*
>> + *
>> + * 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.
>
Sure.
>> + 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
>
Sure.
>> + 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)
>
>
We try to catch the bad API during the netdev FEAT_CHANGE/REGISTER events.
>> + 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.
>
I'll fix it for V4.
>> + 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?
>
No, the callers of this function guarantee that there are less than
MAX_SKB_FRAGS. Specifically, we push the record to TCP once there are
MAX_SKB_FRAGS - 1 frags.
>> + 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/
>
Fixed.
>> + 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?
>
It is not necessary, because once a new record is created we set
offload_ctx->open_record, which is checked before trying to allocate a
new record.
Overall, we prefer not to free memory only to allocate it again once a
bit more memory is available.
>> +
>> + 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/
>
Fixed.
>> + * 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) {
>
>
Sure.
>> + 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?
>
It's somewhat complicated to move it, because the last record handling
logic must also be there inside the loop, and the error handling code
might be required to close a record. If you have an idea, patches are
welcome :)
>> + }
>> + 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
>
Fixed.
>> + (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?
>
Yes, this is on purpose. We want to return the number of bytes
successfully sent before returning an error. See "do_error" and "out"
labels in tcp_sendmsg for similar semantics.
>> +
>> + 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
>
Fixed.
>> +
>> + 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
>
Fixed.
>> +
>> + 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/
>
Fixed.
>> + */
>> + 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/
>
Fixed.
>> + 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
>
Fixed.
>> + 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?
>
I'll add a check in the FEAT_CHANGE netdev event.
>> + &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
>
Fixed.
>> + 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?
>
I'll add a check in FEAT_CHANGE.
>> + 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?
>
You are right, I'll add a check here.
>> + 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/
>
Fixed.
>> + * trim len accordingly. The resulting authentication tag
>> + * will contain garbage. but we don't care as we won't
>
> s/garbage./garbage,/
>
Fixed.
>> + * 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.
>
Sure.
>> +
>> + *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;
>
>
Fixed. Thanks.
>> +}
>> +
>> +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.
>
Fixed.
>> +
>> + 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++)
>
Sure.
>> + 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);
>>
Powered by blists - more mailing lists