diff options
Diffstat (limited to 'net/tls/tls_device.c')
| -rw-r--r-- | net/tls/tls_device.c | 766 |
1 files changed, 766 insertions, 0 deletions
diff --git a/net/tls/tls_device.c b/net/tls/tls_device.c new file mode 100644 index 0000000000000..a7a8f8e20ff30 --- /dev/null +++ b/net/tls/tls_device.c @@ -0,0 +1,766 @@ +/* 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 <crypto/aead.h> +#include <linux/highmem.h> +#include <linux/module.h> +#include <linux/netdevice.h> +#include <net/dst.h> +#include <net/inet_connection_sock.h> +#include <net/tcp.h> +#include <net/tls.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 *offload_ctx = tls_offload_ctx(ctx); + + kfree(offload_ctx); + kfree(ctx); +} + +static void tls_device_gc_task(struct work_struct *work) +{ + struct tls_context *ctx, *tmp; + unsigned long flags; + LIST_HEAD(gc_list); + + 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); + 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 dst_entry *dst = sk_dst_get(sk); + struct net_device *netdev = NULL; + + if (likely(dst)) { + netdev = dst->dev; + dev_hold(netdev); + } + + dst_release(dst); + + 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); + clean_acked_data_disable(inet_csk(sk)); + + if (refcount_dec_and_test(&tls_ctx->refcount)) + tls_device_queue_ctx_destruction(tls_ctx); +} +EXPORT_SYMBOL(tls_device_sk_destruct); + +static void tls_append_frag(struct tls_record_info *record, + 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; + 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 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 prepend */ + frag = &record->frags[0]; + tls_fill_prepend(ctx, + skb_frag_address(frag), + record->len - ctx->tx.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->tx.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->tx); + + 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 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 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; + + 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_HEADER_SIZE is not counted as part of the TLS record, and + * we need to leave room for an authentication tag. + */ + max_open_record_len = TLS_MAX_PAYLOAD_SIZE + + tls_ctx->tx.prepend_size; + do { + rc = tls_do_allocation(sk, ctx, pfrag, + tls_ctx->tx.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->tx.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; + } + 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 || + (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; + + 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; + + 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; + + 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 beggining of the list + */ + 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 nonce_size, tag_size, iv_size, rec_seq_size; + 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_tx) { + 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: + nonce_size = TLS_CIPHER_AES_GCM_128_IV_SIZE; + tag_size = TLS_CIPHER_AES_GCM_128_TAG_SIZE; + iv_size = TLS_CIPHER_AES_GCM_128_IV_SIZE; + iv = ((struct tls12_crypto_info_aes_gcm_128 *)crypto_info)->iv; + rec_seq_size = TLS_CIPHER_AES_GCM_128_REC_SEQ_SIZE; + rec_seq = + ((struct tls12_crypto_info_aes_gcm_128 *)crypto_info)->rec_seq; + break; + default: + rc = -EINVAL; + goto free_offload_ctx; + } + + ctx->tx.prepend_size = TLS_HEADER_SIZE + nonce_size; + ctx->tx.tag_size = tag_size; + ctx->tx.overhead_size = ctx->tx.prepend_size + ctx->tx.tag_size; + ctx->tx.iv_size = iv_size; + ctx->tx.iv = kmalloc(iv_size + TLS_CIPHER_AES_GCM_128_SALT_SIZE, + GFP_KERNEL); + if (!ctx->tx.iv) { + rc = -ENOMEM; + goto free_offload_ctx; + } + + memcpy(ctx->tx.iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE, iv, iv_size); + + ctx->tx.rec_seq_size = rec_seq_size; + ctx->tx.rec_seq = kmalloc(rec_seq_size, GFP_KERNEL); + if (!ctx->tx.rec_seq) { + rc = -ENOMEM; + goto free_iv; + } + memcpy(ctx->tx.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->tx.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); + sg_init_table(offload_ctx->sg_tx_data, + ARRAY_SIZE(offload_ctx->sg_tx_data)); + + clean_acked_data_enable(inet_csk(sk), &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 precede 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_tx = offload_ctx; + rc = netdev->tlsdev_ops->tls_dev_add(netdev, sk, TLS_OFFLOAD_CTX_DIR_TX, + &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); + clean_acked_data_disable(inet_csk(sk)); + crypto_free_aead(offload_ctx->aead_send); +free_rec_seq: + kfree(ctx->tx.rec_seq); +free_iv: + kfree(ctx->tx.iv); +free_offload_ctx: + kfree(offload_ctx); + ctx->priv_ctx_tx = 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 */ + 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); + 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: + if (dev->tlsdev_ops && + dev->tlsdev_ops->tls_dev_add && + dev->tlsdev_ops->tls_dev_del) + return NOTIFY_DONE; + else + return NOTIFY_BAD; + 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); +} |