Merge branch 'tls-rx-decrypt-from-the-tcp-queue'

Jakub Kicinski says:

====================
tls: rx: decrypt from the TCP queue

This is the final part of my TLS Rx rework. It switches from
strparser to decrypting data from skbs queued in TCP. We don't
need the full strparser for TLS, its needs are very basic.
This set gives us a small but measurable (6%) performance
improvement (continuous stream).
====================

Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Jakub Kicinski <[e-mail]>

include/net/tcp.h

···
 int tcp_read_sock(struct sock *sk, read_descriptor_t *desc,
 		  sk_read_actor_t recv_actor);
 int tcp_read_skb(struct sock *sk, skb_read_actor_t recv_actor);
+struct sk_buff *tcp_recv_skb(struct sock *sk, u32 seq, u32 *off);
+void tcp_read_done(struct sock *sk, size_t len);
 
 void tcp_initialize_rcv_mss(struct sock *sk);
 

include/net/tls.h

···
 	unsigned long tx_bitmask;
 };
 
+struct tls_strparser {
+	struct sock *sk;
+
+	u32 mark : 8;
+	u32 stopped : 1;
+	u32 copy_mode : 1;
+	u32 msg_ready : 1;
+
+	struct strp_msg stm;
+
+	struct sk_buff *anchor;
+	struct work_struct work;
+};
+
 struct tls_sw_context_rx {
 	struct crypto_aead *aead_recv;
 	struct crypto_wait async_wait;
-	struct strparser strp;
 	struct sk_buff_head rx_list;	/* list of decrypted 'data' records */
 	void (*saved_data_ready)(struct sock *sk);
 
-	struct sk_buff *recv_pkt;
 	u8 reader_present;
 	u8 async_capable:1;
 	u8 zc_capable:1;
 	u8 reader_contended:1;
+
+	struct tls_strparser strp;
+
 	atomic_t decrypt_pending;
 	/* protect crypto_wait with decrypt_pending*/
 	spinlock_t decrypt_compl_lock;

net/ipv4/tcp.c

···
 	__kfree_skb(skb);
 }
 
-static struct sk_buff *tcp_recv_skb(struct sock *sk, u32 seq, u32 *off)
+struct sk_buff *tcp_recv_skb(struct sock *sk, u32 seq, u32 *off)
 {
 	struct sk_buff *skb;
 	u32 offset;
···
 	}
 	return NULL;
 }
+EXPORT_SYMBOL(tcp_recv_skb);
 
 /*
  * This routine provides an alternative to tcp_recvmsg() for routines
···
 	return copied;
 }
 EXPORT_SYMBOL(tcp_read_skb);
+
+void tcp_read_done(struct sock *sk, size_t len)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	u32 seq = tp->copied_seq;
+	struct sk_buff *skb;
+	size_t left;
+	u32 offset;
+
+	if (sk->sk_state == TCP_LISTEN)
+		return;
+
+	left = len;
+	while (left && (skb = tcp_recv_skb(sk, seq, &offset)) != NULL) {
+		int used;
+
+		used = min_t(size_t, skb->len - offset, left);
+		seq += used;
+		left -= used;
+
+		if (skb->len > offset + used)
+			break;
+
+		if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) {
+			tcp_eat_recv_skb(sk, skb);
+			++seq;
+			break;
+		}
+		tcp_eat_recv_skb(sk, skb);
+	}
+	WRITE_ONCE(tp->copied_seq, seq);
+
+	tcp_rcv_space_adjust(sk);
+
+	/* Clean up data we have read: This will do ACK frames. */
+	if (left != len)
+		tcp_cleanup_rbuf(sk, len - left);
+}
+EXPORT_SYMBOL(tcp_read_done);
 
 int tcp_peek_len(struct socket *sock)
 {

net/tls/tls.h

···
 /*
+ * Copyright (c) 2016 Tom Herbert <[e-mail]>
  * Copyright (c) 2016-2017, Mellanox Technologies. All rights reserved.
  * Copyright (c) 2016-2017, Dave Watson <[e-mail]>. All rights reserved.
  *
···
 			 struct tls_offload_context_tx *offload_ctx,
 			 struct tls_crypto_info *crypto_info);
 
-int tls_strp_msg_hold(struct sock *sk, struct sk_buff *skb,
-		      struct sk_buff_head *dst);
+int tls_strp_dev_init(void);
+void tls_strp_dev_exit(void);
+
+void tls_strp_done(struct tls_strparser *strp);
+void tls_strp_stop(struct tls_strparser *strp);
+int tls_strp_init(struct tls_strparser *strp, struct sock *sk);
+void tls_strp_data_ready(struct tls_strparser *strp);
+
+void tls_strp_check_rcv(struct tls_strparser *strp);
+void tls_strp_msg_done(struct tls_strparser *strp);
+
+int tls_rx_msg_size(struct tls_strparser *strp, struct sk_buff *skb);
+void tls_rx_msg_ready(struct tls_strparser *strp);
+
+void tls_strp_msg_load(struct tls_strparser *strp, bool force_refresh);
+int tls_strp_msg_cow(struct tls_sw_context_rx *ctx);
+struct sk_buff *tls_strp_msg_detach(struct tls_sw_context_rx *ctx);
+int tls_strp_msg_hold(struct tls_strparser *strp, struct sk_buff_head *dst);
 
 static inline struct tls_msg *tls_msg(struct sk_buff *skb)
 {
···
 
 static inline struct sk_buff *tls_strp_msg(struct tls_sw_context_rx *ctx)
 {
-	return ctx->recv_pkt;
+	DEBUG_NET_WARN_ON_ONCE(!ctx->strp.msg_ready || !ctx->strp.anchor->len);
+	return ctx->strp.anchor;
+}
+
+static inline bool tls_strp_msg_ready(struct tls_sw_context_rx *ctx)
+{
+	return ctx->strp.msg_ready;
 }
 
 #ifdef CONFIG_TLS_DEVICE

net/tls/tls_device.c

···
 static int
 tls_device_reencrypt(struct sock *sk, struct tls_sw_context_rx *sw_ctx)
 {
-	int err = 0, offset, copy, nsg, data_len, pos;
-	struct sk_buff *skb, *skb_iter, *unused;
+	int err, offset, copy, data_len, pos;
+	struct sk_buff *skb, *skb_iter;
 	struct scatterlist sg[1];
 	struct strp_msg *rxm;
 	char *orig_buf, *buf;
 
-	skb = tls_strp_msg(sw_ctx);
-	rxm = strp_msg(skb);
-	offset = rxm->offset;
-
+	rxm = strp_msg(tls_strp_msg(sw_ctx));
 	orig_buf = kmalloc(rxm->full_len + TLS_HEADER_SIZE +
 			   TLS_CIPHER_AES_GCM_128_IV_SIZE, sk->sk_allocation);
 	if (!orig_buf)
 		return -ENOMEM;
 	buf = orig_buf;
 
-	nsg = skb_cow_data(skb, 0, &unused);
-	if (unlikely(nsg < 0)) {
-		err = nsg;
+	err = tls_strp_msg_cow(sw_ctx);
+	if (unlikely(err))
 		goto free_buf;
-	}
+
+	skb = tls_strp_msg(sw_ctx);
+	rxm = strp_msg(skb);
+	offset = rxm->offset;
 
 	sg_init_table(sg, 1);
 	sg_set_buf(&sg[0], buf,

net/tls/tls_main.c

···
 	if (tx) {
 		ctx->sk_write_space = sk->sk_write_space;
 		sk->sk_write_space = tls_write_space;
+	} else {
+		struct tls_sw_context_rx *rx_ctx = tls_sw_ctx_rx(ctx);
+
+		tls_strp_check_rcv(&rx_ctx->strp);
 	}
 	return 0;
 
···
 	if (err)
 		return err;
 
+	err = tls_strp_dev_init();
+	if (err)
+		goto err_pernet;
+
 	err = tls_device_init();
-	if (err) {
-		unregister_pernet_subsys(&tls_proc_ops);
-		return err;
-	}
+	if (err)
+		goto err_strp;
 
 	tcp_register_ulp(&tcp_tls_ulp_ops);
 
 	return 0;
+err_strp:
+	tls_strp_dev_exit();
+err_pernet:
+	unregister_pernet_subsys(&tls_proc_ops);
+	return err;
 }
 
 static void __exit tls_unregister(void)
 {
 	tcp_unregister_ulp(&tcp_tls_ulp_ops);
+	tls_strp_dev_exit();
 	tls_device_cleanup();
 	unregister_pernet_subsys(&tls_proc_ops);
 }

net/tls/tls_strp.c

···
 // SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2016 Tom Herbert <[e-mail]> */
 
 #include <linux/skbuff.h>
+#include <linux/workqueue.h>
+#include <net/strparser.h>
+#include <net/tcp.h>
+#include <net/sock.h>
+#include <net/tls.h>
 
 #include "tls.h"
 
-int tls_strp_msg_hold(struct sock *sk, struct sk_buff *skb,
-		      struct sk_buff_head *dst)
-{
-	struct sk_buff *clone;
+static struct workqueue_struct *tls_strp_wq;
 
-	clone = skb_clone(skb, sk->sk_allocation);
-	if (!clone)
+static void tls_strp_abort_strp(struct tls_strparser *strp, int err)
+{
+	if (strp->stopped)
+		return;
+
+	strp->stopped = 1;
+
+	/* Report an error on the lower socket */
+	strp->sk->sk_err = -err;
+	sk_error_report(strp->sk);
+}
+
+static void tls_strp_anchor_free(struct tls_strparser *strp)
+{
+	struct skb_shared_info *shinfo = skb_shinfo(strp->anchor);
+
+	DEBUG_NET_WARN_ON_ONCE(atomic_read(&shinfo->dataref) != 1);
+	shinfo->frag_list = NULL;
+	consume_skb(strp->anchor);
+	strp->anchor = NULL;
+}
+
+/* Create a new skb with the contents of input copied to its page frags */
+static struct sk_buff *tls_strp_msg_make_copy(struct tls_strparser *strp)
+{
+	struct strp_msg *rxm;
+	struct sk_buff *skb;
+	int i, err, offset;
+
+	skb = alloc_skb_with_frags(0, strp->anchor->len, TLS_PAGE_ORDER,
+				   &err, strp->sk->sk_allocation);
+	if (!skb)
+		return NULL;
+
+	offset = strp->stm.offset;
+	for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
+		skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
+
+		WARN_ON_ONCE(skb_copy_bits(strp->anchor, offset,
+					   skb_frag_address(frag),
+					   skb_frag_size(frag)));
+		offset += skb_frag_size(frag);
+	}
+
+	skb_copy_header(skb, strp->anchor);
+	rxm = strp_msg(skb);
+	rxm->offset = 0;
+	return skb;
+}
+
+/* Steal the input skb, input msg is invalid after calling this function */
+struct sk_buff *tls_strp_msg_detach(struct tls_sw_context_rx *ctx)
+{
+	struct tls_strparser *strp = &ctx->strp;
+
+#ifdef CONFIG_TLS_DEVICE
+	DEBUG_NET_WARN_ON_ONCE(!strp->anchor->decrypted);
+#else
+	/* This function turns an input into an output,
+	 * that can only happen if we have offload.
+	 */
+	WARN_ON(1);
+#endif
+
+	if (strp->copy_mode) {
+		struct sk_buff *skb;
+
+		/* Replace anchor with an empty skb, this is a little
+		 * dangerous but __tls_cur_msg() warns on empty skbs
+		 * so hopefully we'll catch abuses.
+		 */
+		skb = alloc_skb(0, strp->sk->sk_allocation);
+		if (!skb)
+			return NULL;
+
+		swap(strp->anchor, skb);
+		return skb;
+	}
+
+	return tls_strp_msg_make_copy(strp);
+}
+
+/* Force the input skb to be in copy mode. The data ownership remains
+ * with the input skb itself (meaning unpause will wipe it) but it can
+ * be modified.
+ */
+int tls_strp_msg_cow(struct tls_sw_context_rx *ctx)
+{
+	struct tls_strparser *strp = &ctx->strp;
+	struct sk_buff *skb;
+
+	if (strp->copy_mode)
+		return 0;
+
+	skb = tls_strp_msg_make_copy(strp);
+	if (!skb)
 		return -ENOMEM;
-	__skb_queue_tail(dst, clone);
+
+	tls_strp_anchor_free(strp);
+	strp->anchor = skb;
+
+	tcp_read_done(strp->sk, strp->stm.full_len);
+	strp->copy_mode = 1;
+
 	return 0;
+}
+
+/* Make a clone (in the skb sense) of the input msg to keep a reference
+ * to the underlying data. The reference-holding skbs get placed on
+ * @dst.
+ */
+int tls_strp_msg_hold(struct tls_strparser *strp, struct sk_buff_head *dst)
+{
+	struct skb_shared_info *shinfo = skb_shinfo(strp->anchor);
+
+	if (strp->copy_mode) {
+		struct sk_buff *skb;
+
+		WARN_ON_ONCE(!shinfo->nr_frags);
+
+		/* We can't skb_clone() the anchor, it gets wiped by unpause */
+		skb = alloc_skb(0, strp->sk->sk_allocation);
+		if (!skb)
+			return -ENOMEM;
+
+		__skb_queue_tail(dst, strp->anchor);
+		strp->anchor = skb;
+	} else {
+		struct sk_buff *iter, *clone;
+		int chunk, len, offset;
+
+		offset = strp->stm.offset;
+		len = strp->stm.full_len;
+		iter = shinfo->frag_list;
+
+		while (len > 0) {
+			if (iter->len <= offset) {
+				offset -= iter->len;
+				goto next;
+			}
+
+			chunk = iter->len - offset;
+			offset = 0;
+
+			clone = skb_clone(iter, strp->sk->sk_allocation);
+			if (!clone)
+				return -ENOMEM;
+			__skb_queue_tail(dst, clone);
+
+			len -= chunk;
+next:
+			iter = iter->next;
+		}
+	}
+
+	return 0;
+}
+
+static void tls_strp_flush_anchor_copy(struct tls_strparser *strp)
+{
+	struct skb_shared_info *shinfo = skb_shinfo(strp->anchor);
+	int i;
+
+	DEBUG_NET_WARN_ON_ONCE(atomic_read(&shinfo->dataref) != 1);
+
+	for (i = 0; i < shinfo->nr_frags; i++)
+		__skb_frag_unref(&shinfo->frags[i], false);
+	shinfo->nr_frags = 0;
+	strp->copy_mode = 0;
+}
+
+static int tls_strp_copyin(read_descriptor_t *desc, struct sk_buff *in_skb,
+			   unsigned int offset, size_t in_len)
+{
+	struct tls_strparser *strp = (struct tls_strparser *)desc->arg.data;
+	size_t sz, len, chunk;
+	struct sk_buff *skb;
+	skb_frag_t *frag;
+
+	if (strp->msg_ready)
+		return 0;
+
+	skb = strp->anchor;
+	frag = &skb_shinfo(skb)->frags[skb->len / PAGE_SIZE];
+
+	len = in_len;
+	/* First make sure we got the header */
+	if (!strp->stm.full_len) {
+		/* Assume one page is more than enough for headers */
+		chunk =	min_t(size_t, len, PAGE_SIZE - skb_frag_size(frag));
+		WARN_ON_ONCE(skb_copy_bits(in_skb, offset,
+					   skb_frag_address(frag) +
+					   skb_frag_size(frag),
+					   chunk));
+
+		sz = tls_rx_msg_size(strp, strp->anchor);
+		if (sz < 0) {
+			desc->error = sz;
+			return 0;
+		}
+
+		/* We may have over-read, sz == 0 is guaranteed under-read */
+		if (sz > 0)
+			chunk =	min_t(size_t, chunk, sz - skb->len);
+
+		skb->len += chunk;
+		skb->data_len += chunk;
+		skb_frag_size_add(frag, chunk);
+		frag++;
+		len -= chunk;
+		offset += chunk;
+
+		strp->stm.full_len = sz;
+		if (!strp->stm.full_len)
+			goto read_done;
+	}
+
+	/* Load up more data */
+	while (len && strp->stm.full_len > skb->len) {
+		chunk =	min_t(size_t, len, strp->stm.full_len - skb->len);
+		chunk = min_t(size_t, chunk, PAGE_SIZE - skb_frag_size(frag));
+		WARN_ON_ONCE(skb_copy_bits(in_skb, offset,
+					   skb_frag_address(frag) +
+					   skb_frag_size(frag),
+					   chunk));
+
+		skb->len += chunk;
+		skb->data_len += chunk;
+		skb_frag_size_add(frag, chunk);
+		frag++;
+		len -= chunk;
+		offset += chunk;
+	}
+
+	if (strp->stm.full_len == skb->len) {
+		desc->count = 0;
+
+		strp->msg_ready = 1;
+		tls_rx_msg_ready(strp);
+	}
+
+read_done:
+	return in_len - len;
+}
+
+static int tls_strp_read_copyin(struct tls_strparser *strp)
+{
+	struct socket *sock = strp->sk->sk_socket;
+	read_descriptor_t desc;
+
+	desc.arg.data = strp;
+	desc.error = 0;
+	desc.count = 1; /* give more than one skb per call */
+
+	/* sk should be locked here, so okay to do read_sock */
+	sock->ops->read_sock(strp->sk, &desc, tls_strp_copyin);
+
+	return desc.error;
+}
+
+static int tls_strp_read_short(struct tls_strparser *strp)
+{
+	struct skb_shared_info *shinfo;
+	struct page *page;
+	int need_spc, len;
+
+	/* If the rbuf is small or rcv window has collapsed to 0 we need
+	 * to read the data out. Otherwise the connection will stall.
+	 * Without pressure threshold of INT_MAX will never be ready.
+	 */
+	if (likely(!tcp_epollin_ready(strp->sk, INT_MAX)))
+		return 0;
+
+	shinfo = skb_shinfo(strp->anchor);
+	shinfo->frag_list = NULL;
+
+	/* If we don't know the length go max plus page for cipher overhead */
+	need_spc = strp->stm.full_len ?: TLS_MAX_PAYLOAD_SIZE + PAGE_SIZE;
+
+	for (len = need_spc; len > 0; len -= PAGE_SIZE) {
+		page = alloc_page(strp->sk->sk_allocation);
+		if (!page) {
+			tls_strp_flush_anchor_copy(strp);
+			return -ENOMEM;
+		}
+
+		skb_fill_page_desc(strp->anchor, shinfo->nr_frags++,
+				   page, 0, 0);
+	}
+
+	strp->copy_mode = 1;
+	strp->stm.offset = 0;
+
+	strp->anchor->len = 0;
+	strp->anchor->data_len = 0;
+	strp->anchor->truesize = round_up(need_spc, PAGE_SIZE);
+
+	tls_strp_read_copyin(strp);
+
+	return 0;
+}
+
+static void tls_strp_load_anchor_with_queue(struct tls_strparser *strp, int len)
+{
+	struct tcp_sock *tp = tcp_sk(strp->sk);
+	struct sk_buff *first;
+	u32 offset;
+
+	first = tcp_recv_skb(strp->sk, tp->copied_seq, &offset);
+	if (WARN_ON_ONCE(!first))
+		return;
+
+	/* Bestow the state onto the anchor */
+	strp->anchor->len = offset + len;
+	strp->anchor->data_len = offset + len;
+	strp->anchor->truesize = offset + len;
+
+	skb_shinfo(strp->anchor)->frag_list = first;
+
+	skb_copy_header(strp->anchor, first);
+	strp->anchor->destructor = NULL;
+
+	strp->stm.offset = offset;
+}
+
+void tls_strp_msg_load(struct tls_strparser *strp, bool force_refresh)
+{
+	struct strp_msg *rxm;
+	struct tls_msg *tlm;
+
+	DEBUG_NET_WARN_ON_ONCE(!strp->msg_ready);
+	DEBUG_NET_WARN_ON_ONCE(!strp->stm.full_len);
+
+	if (!strp->copy_mode && force_refresh) {
+		if (WARN_ON(tcp_inq(strp->sk) < strp->stm.full_len))
+			return;
+
+		tls_strp_load_anchor_with_queue(strp, strp->stm.full_len);
+	}
+
+	rxm = strp_msg(strp->anchor);
+	rxm->full_len	= strp->stm.full_len;
+	rxm->offset	= strp->stm.offset;
+	tlm = tls_msg(strp->anchor);
+	tlm->control	= strp->mark;
+}
+
+/* Called with lock held on lower socket */
+static int tls_strp_read_sock(struct tls_strparser *strp)
+{
+	int sz, inq;
+
+	inq = tcp_inq(strp->sk);
+	if (inq < 1)
+		return 0;
+
+	if (unlikely(strp->copy_mode))
+		return tls_strp_read_copyin(strp);
+
+	if (inq < strp->stm.full_len)
+		return tls_strp_read_short(strp);
+
+	if (!strp->stm.full_len) {
+		tls_strp_load_anchor_with_queue(strp, inq);
+
+		sz = tls_rx_msg_size(strp, strp->anchor);
+		if (sz < 0) {
+			tls_strp_abort_strp(strp, sz);
+			return sz;
+		}
+
+		strp->stm.full_len = sz;
+
+		if (!strp->stm.full_len || inq < strp->stm.full_len)
+			return tls_strp_read_short(strp);
+	}
+
+	strp->msg_ready = 1;
+	tls_rx_msg_ready(strp);
+
+	return 0;
+}
+
+void tls_strp_check_rcv(struct tls_strparser *strp)
+{
+	if (unlikely(strp->stopped) || strp->msg_ready)
+		return;
+
+	if (tls_strp_read_sock(strp) == -ENOMEM)
+		queue_work(tls_strp_wq, &strp->work);
+}
+
+/* Lower sock lock held */
+void tls_strp_data_ready(struct tls_strparser *strp)
+{
+	/* This check is needed to synchronize with do_tls_strp_work.
+	 * do_tls_strp_work acquires a process lock (lock_sock) whereas
+	 * the lock held here is bh_lock_sock. The two locks can be
+	 * held by different threads at the same time, but bh_lock_sock
+	 * allows a thread in BH context to safely check if the process
+	 * lock is held. In this case, if the lock is held, queue work.
+	 */
+	if (sock_owned_by_user_nocheck(strp->sk)) {
+		queue_work(tls_strp_wq, &strp->work);
+		return;
+	}
+
+	tls_strp_check_rcv(strp);
+}
+
+static void tls_strp_work(struct work_struct *w)
+{
+	struct tls_strparser *strp =
+		container_of(w, struct tls_strparser, work);
+
+	lock_sock(strp->sk);
+	tls_strp_check_rcv(strp);
+	release_sock(strp->sk);
+}
+
+void tls_strp_msg_done(struct tls_strparser *strp)
+{
+	WARN_ON(!strp->stm.full_len);
+
+	if (likely(!strp->copy_mode))
+		tcp_read_done(strp->sk, strp->stm.full_len);
+	else
+		tls_strp_flush_anchor_copy(strp);
+
+	strp->msg_ready = 0;
+	memset(&strp->stm, 0, sizeof(strp->stm));
+
+	tls_strp_check_rcv(strp);
+}
+
+void tls_strp_stop(struct tls_strparser *strp)
+{
+	strp->stopped = 1;
+}
+
+int tls_strp_init(struct tls_strparser *strp, struct sock *sk)
+{
+	memset(strp, 0, sizeof(*strp));
+
+	strp->sk = sk;
+
+	strp->anchor = alloc_skb(0, GFP_KERNEL);
+	if (!strp->anchor)
+		return -ENOMEM;
+
+	INIT_WORK(&strp->work, tls_strp_work);
+
+	return 0;
+}
+
+/* strp must already be stopped so that tls_strp_recv will no longer be called.
+ * Note that tls_strp_done is not called with the lower socket held.
+ */
+void tls_strp_done(struct tls_strparser *strp)
+{
+	WARN_ON(!strp->stopped);
+
+	cancel_work_sync(&strp->work);
+	tls_strp_anchor_free(strp);
+}
+
+int __init tls_strp_dev_init(void)
+{
+	tls_strp_wq = create_singlethread_workqueue("kstrp");
+	if (unlikely(!tls_strp_wq))
+		return -ENOMEM;
+
+	return 0;
+}
+
+void tls_strp_dev_exit(void)
+{
+	destroy_workqueue(tls_strp_wq);
 }

net/tls/tls_sw.c

···
 
 static int
 tls_rx_rec_wait(struct sock *sk, struct sk_psock *psock, bool nonblock,
-		long timeo)
+		bool released, long timeo)
 {
 	struct tls_context *tls_ctx = tls_get_ctx(sk);
 	struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
 
-	while (!ctx->recv_pkt) {
+	while (!tls_strp_msg_ready(ctx)) {
 		if (!sk_psock_queue_empty(psock))
 			return 0;
 
···
 			return sock_error(sk);
 
 		if (!skb_queue_empty(&sk->sk_receive_queue)) {
-			__strp_unpause(&ctx->strp);
-			if (ctx->recv_pkt)
+			tls_strp_check_rcv(&ctx->strp);
+			if (tls_strp_msg_ready(ctx))
 				break;
 		}
 
···
 		if (nonblock || !timeo)
 			return -EAGAIN;
 
+		released = true;
 		add_wait_queue(sk_sleep(sk), &wait);
 		sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
 		sk_wait_event(sk, &timeo,
-			      ctx->recv_pkt || !sk_psock_queue_empty(psock),
+			      tls_strp_msg_ready(ctx) ||
+			      !sk_psock_queue_empty(psock),
 			      &wait);
 		sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
 		remove_wait_queue(sk_sleep(sk), &wait);
···
 		if (signal_pending(current))
 			return sock_intr_errno(timeo);
 	}
+
+	tls_strp_msg_load(&ctx->strp, released);
 
 	return 1;
 }
···
 
 /* Decrypt handlers
  *
- * tls_decrypt_sg() and tls_decrypt_device() are decrypt handlers.
+ * tls_decrypt_sw() and tls_decrypt_device() are decrypt handlers.
  * They must transform the darg in/out argument are as follows:
  *       |          Input            |         Output
  * -------------------------------------------------------------------
  *    zc | Zero-copy decrypt allowed | Zero-copy performed
  * async | Async decrypt allowed     | Async crypto used / in progress
  *   skb |            *              | Output skb
+ *
+ * If ZC decryption was performed darg.skb will point to the input skb.
  */
 
 /* This function decrypts the input skb into either out_iov or in out_sg
···
 	clear_skb = NULL;
 
 	if (unlikely(darg->async)) {
-		err = tls_strp_msg_hold(sk, skb, &ctx->async_hold);
+		err = tls_strp_msg_hold(&ctx->strp, &ctx->async_hold);
 		if (err)
 			__skb_queue_tail(&ctx->async_hold, darg->skb);
 		return err;
···
 }
 
 static int
-tls_decrypt_device(struct sock *sk, struct tls_context *tls_ctx,
-		   struct tls_decrypt_arg *darg)
+tls_decrypt_sw(struct sock *sk, struct tls_context *tls_ctx,
+	       struct msghdr *msg, struct tls_decrypt_arg *darg)
 {
 	struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
-	int err;
+	struct tls_prot_info *prot = &tls_ctx->prot_info;
+	struct strp_msg *rxm;
+	int pad, err;
+
+	err = tls_decrypt_sg(sk, &msg->msg_iter, NULL, darg);
+	if (err < 0) {
+		if (err == -EBADMSG)
+			TLS_INC_STATS(sock_net(sk), LINUX_MIB_TLSDECRYPTERROR);
+		return err;
+	}
+	/* keep going even for ->async, the code below is TLS 1.3 */
+
+	/* If opportunistic TLS 1.3 ZC failed retry without ZC */
+	if (unlikely(darg->zc && prot->version == TLS_1_3_VERSION &&
+		     darg->tail != TLS_RECORD_TYPE_DATA)) {
+		darg->zc = false;
+		if (!darg->tail)
+			TLS_INC_STATS(sock_net(sk), LINUX_MIB_TLSRXNOPADVIOL);
+		TLS_INC_STATS(sock_net(sk), LINUX_MIB_TLSDECRYPTRETRY);
+		return tls_decrypt_sw(sk, tls_ctx, msg, darg);
+	}
+
+	pad = tls_padding_length(prot, darg->skb, darg);
+	if (pad < 0) {
+		if (darg->skb != tls_strp_msg(ctx))
+			consume_skb(darg->skb);
+		return pad;
+	}
+
+	rxm = strp_msg(darg->skb);
+	rxm->full_len -= pad;
+
+	return 0;
+}
+
+static int
+tls_decrypt_device(struct sock *sk, struct msghdr *msg,
+		   struct tls_context *tls_ctx, struct tls_decrypt_arg *darg)
+{
+	struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
+	struct tls_prot_info *prot = &tls_ctx->prot_info;
+	struct strp_msg *rxm;
+	int pad, err;
 
 	if (tls_ctx->rx_conf != TLS_HW)
 		return 0;
···
 	if (err <= 0)
 		return err;
 
-	darg->zc = false;
+	pad = tls_padding_length(prot, tls_strp_msg(ctx), darg);
+	if (pad < 0)
+		return pad;
+
 	darg->async = false;
 	darg->skb = tls_strp_msg(ctx);
-	ctx->recv_pkt = NULL;
-	return 1;
-}
-
-static int tls_rx_one_record(struct sock *sk, struct iov_iter *dest,
-			     struct tls_decrypt_arg *darg)
-{
-	struct tls_context *tls_ctx = tls_get_ctx(sk);
-	struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
-	struct tls_prot_info *prot = &tls_ctx->prot_info;
-	struct strp_msg *rxm;
-	int pad, err;
-
-	err = tls_decrypt_device(sk, tls_ctx, darg);
-	if (err < 0)
-		return err;
-	if (err)
-		goto decrypt_done;
-
-	err = tls_decrypt_sg(sk, dest, NULL, darg);
-	if (err < 0) {
-		if (err == -EBADMSG)
-			TLS_INC_STATS(sock_net(sk), LINUX_MIB_TLSDECRYPTERROR);
-		return err;
-	}
-	if (darg->async)
-		goto decrypt_done;
-	/* If opportunistic TLS 1.3 ZC failed retry without ZC */
-	if (unlikely(darg->zc && prot->version == TLS_1_3_VERSION &&
-		     darg->tail != TLS_RECORD_TYPE_DATA)) {
-		darg->zc = false;
-		if (!darg->tail)
-			TLS_INC_STATS(sock_net(sk), LINUX_MIB_TLSRXNOPADVIOL);
-		TLS_INC_STATS(sock_net(sk), LINUX_MIB_TLSDECRYPTRETRY);
-		return tls_rx_one_record(sk, dest, darg);
-	}
-
-decrypt_done:
-	if (darg->skb == ctx->recv_pkt)
-		ctx->recv_pkt = NULL;
-
-	pad = tls_padding_length(prot, darg->skb, darg);
-	if (pad < 0) {
-		consume_skb(darg->skb);
-		return pad;
-	}
+	/* ->zc downgrade check, in case TLS 1.3 gets here */
+	darg->zc &= !(prot->version == TLS_1_3_VERSION &&
+		      tls_msg(darg->skb)->control != TLS_RECORD_TYPE_DATA);
 
 	rxm = strp_msg(darg->skb);
 	rxm->full_len -= pad;
+
+	if (!darg->zc) {
+		/* Non-ZC case needs a real skb */
+		darg->skb = tls_strp_msg_detach(ctx);
+		if (!darg->skb)
+			return -ENOMEM;
+	} else {
+		unsigned int off, len;
+
+		/* In ZC case nobody cares about the output skb.
+		 * Just copy the data here. Note the skb is not fully trimmed.
+		 */
+		off = rxm->offset + prot->prepend_size;
+		len = rxm->full_len - prot->overhead_size;
+
+		err = skb_copy_datagram_msg(darg->skb, off, msg, len);
+		if (err)
+			return err;
+	}
+	return 1;
+}
+
+static int tls_rx_one_record(struct sock *sk, struct msghdr *msg,
+			     struct tls_decrypt_arg *darg)
+{
+	struct tls_context *tls_ctx = tls_get_ctx(sk);
+	struct tls_prot_info *prot = &tls_ctx->prot_info;
+	struct strp_msg *rxm;
+	int err;
+
+	err = tls_decrypt_device(sk, msg, tls_ctx, darg);
+	if (!err)
+		err = tls_decrypt_sw(sk, tls_ctx, msg, darg);
+	if (err < 0)
+		return err;
+
+	rxm = strp_msg(darg->skb);
 	rxm->offset += prot->prepend_size;
 	rxm->full_len -= prot->overhead_size;
 	tls_advance_record_sn(sk, prot, &tls_ctx->rx);
···
 
 static void tls_rx_rec_done(struct tls_sw_context_rx *ctx)
 {
-	consume_skb(ctx->recv_pkt);
-	ctx->recv_pkt = NULL;
-	__strp_unpause(&ctx->strp);
+	tls_strp_msg_done(&ctx->strp);
 }
 
 /* This function traverses the rx_list in tls receive context to copies the
···
 	return copied ? : err;
 }
 
-static void
+static bool
 tls_read_flush_backlog(struct sock *sk, struct tls_prot_info *prot,
 		       size_t len_left, size_t decrypted, ssize_t done,
 		       size_t *flushed_at)
···
 	size_t max_rec;
 
 	if (len_left <= decrypted)
-		return;
+		return false;
 
 	max_rec = prot->overhead_size - prot->tail_size + TLS_MAX_PAYLOAD_SIZE;
 	if (done - *flushed_at < SZ_128K && tcp_inq(sk) > max_rec)
-		return;
+		return false;
 
 	*flushed_at = done;
-	sk_flush_backlog(sk);
+	return sk_flush_backlog(sk);
 }
 
 static long tls_rx_reader_lock(struct sock *sk, struct tls_sw_context_rx *ctx,
···
 	size_t flushed_at = 0;
 	struct strp_msg *rxm;
 	struct tls_msg *tlm;
-	struct sk_buff *skb;
 	ssize_t copied = 0;
 	bool async = false;
 	int target, err = 0;
 	long timeo;
 	bool is_kvec = iov_iter_is_kvec(&msg->msg_iter);
 	bool is_peek = flags & MSG_PEEK;
+	bool released = true;
 	bool bpf_strp_enabled;
 	bool zc_capable;
 
···
 	zc_capable = !bpf_strp_enabled && !is_kvec && !is_peek &&
 		ctx->zc_capable;
 	decrypted = 0;
-	while (len && (decrypted + copied < target || ctx->recv_pkt)) {
+	while (len && (decrypted + copied < target || tls_strp_msg_ready(ctx))) {
 		struct tls_decrypt_arg darg;
 		int to_decrypt, chunk;
 
-		err = tls_rx_rec_wait(sk, psock, flags & MSG_DONTWAIT, timeo);
+		err = tls_rx_rec_wait(sk, psock, flags & MSG_DONTWAIT, released,
+				      timeo);
 		if (err <= 0) {
 			if (psock) {
 				chunk = sk_msg_recvmsg(sk, psock, msg, len,
···
 
 		memset(&darg.inargs, 0, sizeof(darg.inargs));
 
-		rxm = strp_msg(ctx->recv_pkt);
-		tlm = tls_msg(ctx->recv_pkt);
+		rxm = strp_msg(tls_strp_msg(ctx));
+		tlm = tls_msg(tls_strp_msg(ctx));
 
 		to_decrypt = rxm->full_len - prot->overhead_size;
 
···
 		else
 			darg.async = false;
 
-		err = tls_rx_one_record(sk, &msg->msg_iter, &darg);
+		err = tls_rx_one_record(sk, msg, &darg);
 		if (err < 0) {
 			tls_err_abort(sk, -EBADMSG);
 			goto recv_end;
 		}
-
-		skb = darg.skb;
-		rxm = strp_msg(skb);
-		tlm = tls_msg(skb);
 
 		async |= darg.async;
 
···
 		 * is known just after record is dequeued from stream parser.
 		 * For tls1.3, we disable async.
 		 */
-		err = tls_record_content_type(msg, tlm, &control);
+		err = tls_record_content_type(msg, tls_msg(darg.skb), &control);
 		if (err <= 0) {
+			DEBUG_NET_WARN_ON_ONCE(darg.zc);
 			tls_rx_rec_done(ctx);
 put_on_rx_list_err:
-			__skb_queue_tail(&ctx->rx_list, skb);
+			__skb_queue_tail(&ctx->rx_list, darg.skb);
 			goto recv_end;
 		}
 
 		/* periodically flush backlog, and feed strparser */
-		tls_read_flush_backlog(sk, prot, len, to_decrypt,
-				       decrypted + copied, &flushed_at);
+		released = tls_read_flush_backlog(sk, prot, len, to_decrypt,
+						  decrypted + copied,
+						  &flushed_at);
 
 		/* TLS 1.3 may have updated the length by more than overhead */
+		rxm = strp_msg(darg.skb);
 		chunk = rxm->full_len;
 		tls_rx_rec_done(ctx);
 
 		if (!darg.zc) {
 			bool partially_consumed = chunk > len;
+			struct sk_buff *skb = darg.skb;
+
+			DEBUG_NET_WARN_ON_ONCE(darg.skb == tls_strp_msg(ctx));
 
 			if (async) {
 				/* TLS 1.2-only, to_decrypt must be text len */
···
 			}
 
 			if (bpf_strp_enabled) {
+				released = true;
 				err = sk_psock_tls_strp_read(psock, skb);
 				if (err != __SK_PASS) {
 					rxm->offset = rxm->offset + rxm->full_len;
···
 				rxm->full_len -= chunk;
 				goto put_on_rx_list;
 			}
+
+			consume_skb(skb);
 		}
 
 		decrypted += chunk;
 		len -= chunk;
-
-		consume_skb(skb);
 
 		/* Return full control message to userspace before trying
 		 * to parse another message type
···
 		struct tls_decrypt_arg darg;
 
 		err = tls_rx_rec_wait(sk, NULL, flags & SPLICE_F_NONBLOCK,
-				      timeo);
+				      true, timeo);
 		if (err <= 0)
 			goto splice_read_end;
 
···
 		ingress_empty = list_empty(&psock->ingress_msg);
 	rcu_read_unlock();
 
-	return !ingress_empty || ctx->recv_pkt ||
+	return !ingress_empty || tls_strp_msg_ready(ctx) ||
 		!skb_queue_empty(&ctx->rx_list);
 }
 
-static int tls_read_size(struct strparser *strp, struct sk_buff *skb)
+int tls_rx_msg_size(struct tls_strparser *strp, struct sk_buff *skb)
 {
 	struct tls_context *tls_ctx = tls_get_ctx(strp->sk);
 	struct tls_prot_info *prot = &tls_ctx->prot_info;
 	char header[TLS_HEADER_SIZE + MAX_IV_SIZE];
-	struct strp_msg *rxm = strp_msg(skb);
-	struct tls_msg *tlm = tls_msg(skb);
 	size_t cipher_overhead;
 	size_t data_len = 0;
 	int ret;
 
 	/* Verify that we have a full TLS header, or wait for more data */
-	if (rxm->offset + prot->prepend_size > skb->len)
+	if (strp->stm.offset + prot->prepend_size > skb->len)
 		return 0;
 
 	/* Sanity-check size of on-stack buffer. */
···
 	}
 
 	/* Linearize header to local buffer */
-	ret = skb_copy_bits(skb, rxm->offset, header, prot->prepend_size);
+	ret = skb_copy_bits(skb, strp->stm.offset, header, prot->prepend_size);
 	if (ret < 0)
 		goto read_failure;
 
-	tlm->control = header[0];
+	strp->mark = header[0];
 
 	data_len = ((header[4] & 0xFF) | (header[3] << 8));
 
···
 	}
 
 	tls_device_rx_resync_new_rec(strp->sk, data_len + TLS_HEADER_SIZE,
-				     TCP_SKB_CB(skb)->seq + rxm->offset);
+				     TCP_SKB_CB(skb)->seq + strp->stm.offset);
 	return data_len + TLS_HEADER_SIZE;
 
 read_failure:
···
 	return ret;
 }
 
-static void tls_queue(struct strparser *strp, struct sk_buff *skb)
+void tls_rx_msg_ready(struct tls_strparser *strp)
 {
-	struct tls_context *tls_ctx = tls_get_ctx(strp->sk);
-	struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
+	struct tls_sw_context_rx *ctx;
 
-	ctx->recv_pkt = skb;
-	strp_pause(strp);
-
+	ctx = container_of(strp, struct tls_sw_context_rx, strp);
 	ctx->saved_data_ready(strp->sk);
 }
 
···
 	struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
 	struct sk_psock *psock;
 
-	strp_data_ready(&ctx->strp);
+	tls_strp_data_ready(&ctx->strp);
 
 	psock = sk_psock_get(sk);
 	if (psock) {
···
 	kfree(tls_ctx->rx.iv);
 
 	if (ctx->aead_recv) {
-		kfree_skb(ctx->recv_pkt);
-		ctx->recv_pkt = NULL;
 		__skb_queue_purge(&ctx->rx_list);
 		crypto_free_aead(ctx->aead_recv);
-		strp_stop(&ctx->strp);
+		tls_strp_stop(&ctx->strp);
 		/* If tls_sw_strparser_arm() was not called (cleanup paths)
-		 * we still want to strp_stop(), but sk->sk_data_ready was
+		 * we still want to tls_strp_stop(), but sk->sk_data_ready was
 		 * never swapped.
 		 */
 		if (ctx->saved_data_ready) {
···
 {
 	struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
 
-	strp_done(&ctx->strp);
+	tls_strp_done(&ctx->strp);
 }
 
 void tls_sw_free_ctx_rx(struct tls_context *tls_ctx)
···
 	rx_ctx->saved_data_ready = sk->sk_data_ready;
 	sk->sk_data_ready = tls_data_ready;
 	write_unlock_bh(&sk->sk_callback_lock);
-
-	strp_check_rcv(&rx_ctx->strp);
 }
 
 void tls_update_rx_zc_capable(struct tls_context *tls_ctx)
···
 	struct tls_sw_context_rx *sw_ctx_rx = NULL;
 	struct cipher_context *cctx;
 	struct crypto_aead **aead;
-	struct strp_callbacks cb;
 	u16 nonce_size, tag_size, iv_size, rec_seq_size, salt_size;
 	struct crypto_tfm *tfm;
 	char *iv, *rec_seq, *key, *salt, *cipher_name;
···
 			crypto_info->version != TLS_1_3_VERSION &&
 			!!(tfm->__crt_alg->cra_flags & CRYPTO_ALG_ASYNC);
 
-		/* Set up strparser */
-		memset(&cb, 0, sizeof(cb));
-		cb.rcv_msg = tls_queue;
-		cb.parse_msg = tls_read_size;
-
-		strp_init(&sw_ctx_rx->strp, sk, &cb);
+		tls_strp_init(&sw_ctx_rx->strp, sk);
 	}
 
 	goto out;