Merge branch 'tls-rx-refactor-part-3'

Jakub Kicinski says:

====================
tls: rx: random refactoring part 3

TLS Rx refactoring. Part 3 of 3. This set is mostly around rx_list
and async processing. The last two patches are minor optimizations.
A couple of features to follow.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 60 insertions, 71 deletions

diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c
index 17c4e236ec8b..ddbe05ec5489 100644
--- a/net/tls/tls_sw.c
+++ b/net/tls/tls_sw.c
@@ -188,17 +188,12 @@ static void tls_decrypt_done(struct crypto_async_request *req, int err)
 		tls_err_abort(skb->sk, err);
 	} else {
 		struct strp_msg *rxm = strp_msg(skb);
-		int pad;
 
-		pad = padding_length(prot, skb);
-		if (pad < 0) {
-			ctx->async_wait.err = pad;
-			tls_err_abort(skb->sk, pad);
-		} else {
-			rxm->full_len -= pad;
-			rxm->offset += prot->prepend_size;
-			rxm->full_len -= prot->overhead_size;
-		}
+		/* No TLS 1.3 support with async crypto */
+		WARN_ON(prot->tail_size);
+
+		rxm->offset += prot->prepend_size;
+		rxm->full_len -= prot->overhead_size;
 	}
 
 	/* After using skb->sk to propagate sk through crypto async callback
@@ -232,7 +227,7 @@ static int tls_do_decryption(struct sock *sk,
 			     char *iv_recv,
 			     size_t data_len,
 			     struct aead_request *aead_req,
-			     bool async)
+			     struct tls_decrypt_arg *darg)
 {
 	struct tls_context *tls_ctx = tls_get_ctx(sk);
 	struct tls_prot_info *prot = &tls_ctx->prot_info;
@@ -245,7 +240,7 @@ static int tls_do_decryption(struct sock *sk,
 			       data_len + prot->tag_size,
 			       (u8 *)iv_recv);
 
-	if (async) {
+	if (darg->async) {
 		/* Using skb->sk to push sk through to crypto async callback
 		 * handler. This allows propagating errors up to the socket
 		 * if needed. It _must_ be cleared in the async handler
@@ -265,14 +260,15 @@ static int tls_do_decryption(struct sock *sk,
 
 	ret = crypto_aead_decrypt(aead_req);
 	if (ret == -EINPROGRESS) {
-		if (async)
-			return ret;
+		if (darg->async)
+			return 0;
 
 		ret = crypto_wait_req(ret, &ctx->async_wait);
 	}
+	darg->async = false;
 
-	if (async)
-		atomic_dec(&ctx->decrypt_pending);
+	if (ret == -EBADMSG)
+		TLS_INC_STATS(sock_net(sk), LINUX_MIB_TLSDECRYPTERROR);
 
 	return ret;
 }
@@ -1456,7 +1452,7 @@ static int decrypt_internal(struct sock *sk, struct sk_buff *skb,
 	aead_size = sizeof(*aead_req) + crypto_aead_reqsize(ctx->aead_recv);
 	mem_size = aead_size + (nsg * sizeof(struct scatterlist));
 	mem_size = mem_size + prot->aad_size;
-	mem_size = mem_size + crypto_aead_ivsize(ctx->aead_recv);
+	mem_size = mem_size + MAX_IV_SIZE;
 
 	/* Allocate a single block of memory which contains
 	 * aead_req || sgin[] || sgout[] || aad || iv.
@@ -1486,20 +1482,20 @@ static int decrypt_internal(struct sock *sk, struct sk_buff *skb,
 	}
 
 	/* Prepare IV */
-	err = skb_copy_bits(skb, rxm->offset + TLS_HEADER_SIZE,
-			    iv + iv_offset + prot->salt_size,
-			    prot->iv_size);
-	if (err < 0) {
-		kfree(mem);
-		return err;
-	}
 	if (prot->version == TLS_1_3_VERSION ||
-	    prot->cipher_type == TLS_CIPHER_CHACHA20_POLY1305)
+	    prot->cipher_type == TLS_CIPHER_CHACHA20_POLY1305) {
 		memcpy(iv + iv_offset, tls_ctx->rx.iv,
 		       prot->iv_size + prot->salt_size);
-	else
+	} else {
+		err = skb_copy_bits(skb, rxm->offset + TLS_HEADER_SIZE,
+				    iv + iv_offset + prot->salt_size,
+				    prot->iv_size);
+		if (err < 0) {
+			kfree(mem);
+			return err;
+		}
 		memcpy(iv + iv_offset, tls_ctx->rx.iv, prot->salt_size);
-
+	}
 	xor_iv_with_seq(prot, iv + iv_offset, tls_ctx->rx.rec_seq);
 
 	/* Prepare AAD */
@@ -1542,9 +1538,9 @@ fallback_to_reg_recv:
 
 	/* Prepare and submit AEAD request */
 	err = tls_do_decryption(sk, skb, sgin, sgout, iv,
-				data_len, aead_req, darg->async);
-	if (err == -EINPROGRESS)
-		return err;
+				data_len, aead_req, darg);
+	if (darg->async)
+		return 0;
 
 	/* Release the pages in case iov was mapped to pages */
 	for (; pages > 0; pages--)
@@ -1581,13 +1577,10 @@ static int decrypt_skb_update(struct sock *sk, struct sk_buff *skb,
 	}
 
 	err = decrypt_internal(sk, skb, dest, NULL, darg);
-	if (err < 0) {
-		if (err == -EINPROGRESS)
-			tls_advance_record_sn(sk, prot, &tls_ctx->rx);
-		else if (err == -EBADMSG)
-			TLS_INC_STATS(sock_net(sk), LINUX_MIB_TLSDECRYPTERROR);
+	if (err < 0)
 		return err;
-	}
+	if (darg->async)
+		goto decrypt_next;
 
 decrypt_done:
 	pad = padding_length(prot, skb);
@@ -1597,8 +1590,9 @@ decrypt_done:
 	rxm->full_len -= pad;
 	rxm->offset += prot->prepend_size;
 	rxm->full_len -= prot->overhead_size;
-	tls_advance_record_sn(sk, prot, &tls_ctx->rx);
 	tlm->decrypted = 1;
+decrypt_next:
+	tls_advance_record_sn(sk, prot, &tls_ctx->rx);
 
 	return 0;
 }
@@ -1658,7 +1652,7 @@ static int process_rx_list(struct tls_sw_context_rx *ctx,
 
 		err = tls_record_content_type(msg, tlm, control);
 		if (err <= 0)
-			return err;
+			goto out;
 
 		if (skip < rxm->full_len)
 			break;
@@ -1676,13 +1670,13 @@ static int process_rx_list(struct tls_sw_context_rx *ctx,
 
 		err = tls_record_content_type(msg, tlm, control);
 		if (err <= 0)
-			return err;
+			goto out;
 
 		if (!zc || (rxm->full_len - skip) > len) {
 			err = skb_copy_datagram_msg(skb, rxm->offset + skip,
 						    msg, chunk);
 			if (err < 0)
-				return err;
+				goto out;
 		}
 
 		len = len - chunk;
@@ -1709,14 +1703,16 @@ static int process_rx_list(struct tls_sw_context_rx *ctx,
 		next_skb = skb_peek_next(skb, &ctx->rx_list);
 
 		if (!is_peek) {
-			skb_unlink(skb, &ctx->rx_list);
+			__skb_unlink(skb, &ctx->rx_list);
 			consume_skb(skb);
 		}
 
 		skb = next_skb;
 	}
+	err = 0;
 
-	return copied;
+out:
+	return copied ? : err;
 }
 
 int tls_sw_recvmsg(struct sock *sk,
@@ -1750,12 +1746,15 @@ int tls_sw_recvmsg(struct sock *sk,
 	lock_sock(sk);
 	bpf_strp_enabled = sk_psock_strp_enabled(psock);
 
+	/* If crypto failed the connection is broken */
+	err = ctx->async_wait.err;
+	if (err)
+		goto end;
+
 	/* Process pending decrypted records. It must be non-zero-copy */
 	err = process_rx_list(ctx, msg, &control, 0, len, false, is_peek);
-	if (err < 0) {
-		tls_err_abort(sk, err);
+	if (err < 0)
 		goto end;
-	}
 
 	copied = err;
 	if (len <= copied)
@@ -1775,14 +1774,10 @@ int tls_sw_recvmsg(struct sock *sk,
 		skb = tls_wait_data(sk, psock, flags & MSG_DONTWAIT, timeo, &err);
 		if (!skb) {
 			if (psock) {
-				int ret = sk_msg_recvmsg(sk, psock, msg, len,
-							 flags);
-
-				if (ret > 0) {
-					decrypted += ret;
-					len -= ret;
-					continue;
-				}
+				chunk = sk_msg_recvmsg(sk, psock, msg, len,
+						       flags);
+				if (chunk > 0)
+					goto leave_on_list;
 			}
 			goto recv_end;
 		}
@@ -1803,13 +1798,12 @@ int tls_sw_recvmsg(struct sock *sk,
 			darg.async = false;
 
 		err = decrypt_skb_update(sk, skb, &msg->msg_iter, &darg);
-		if (err < 0 && err != -EINPROGRESS) {
+		if (err < 0) {
 			tls_err_abort(sk, -EBADMSG);
 			goto recv_end;
 		}
 
-		if (err == -EINPROGRESS)
-			async = true;
+		async |= darg.async;
 
 		/* If the type of records being processed is not known yet,
 		 * set it to record type just dequeued. If it is already known,
@@ -1824,7 +1818,7 @@ int tls_sw_recvmsg(struct sock *sk,
 
 		ctx->recv_pkt = NULL;
 		__strp_unpause(&ctx->strp);
-		skb_queue_tail(&ctx->rx_list, skb);
+		__skb_queue_tail(&ctx->rx_list, skb);
 
 		if (async) {
 			/* TLS 1.2-only, to_decrypt must be text length */
@@ -1845,7 +1839,7 @@ leave_on_list:
 				if (err != __SK_PASS) {
 					rxm->offset = rxm->offset + rxm->full_len;
 					rxm->full_len = 0;
-					skb_unlink(skb, &ctx->rx_list);
+					__skb_unlink(skb, &ctx->rx_list);
 					if (err == __SK_DROP)
 						consume_skb(skb);
 					continue;
@@ -1873,7 +1867,7 @@ leave_on_list:
 		decrypted += chunk;
 		len -= chunk;
 
-		skb_unlink(skb, &ctx->rx_list);
+		__skb_unlink(skb, &ctx->rx_list);
 		consume_skb(skb);
 
 		/* Return full control message to userspace before trying
@@ -1886,7 +1880,7 @@ leave_on_list:
 
 recv_end:
 	if (async) {
-		int pending;
+		int ret, pending;
 
 		/* Wait for all previously submitted records to be decrypted */
 		spin_lock_bh(&ctx->decrypt_compl_lock);
@@ -1894,11 +1888,10 @@ recv_end:
 		pending = atomic_read(&ctx->decrypt_pending);
 		spin_unlock_bh(&ctx->decrypt_compl_lock);
 		if (pending) {
-			err = crypto_wait_req(-EINPROGRESS, &ctx->async_wait);
-			if (err) {
-				/* one of async decrypt failed */
-				tls_err_abort(sk, err);
-				copied = 0;
+			ret = crypto_wait_req(-EINPROGRESS, &ctx->async_wait);
+			if (ret) {
+				if (err >= 0 || err == -EINPROGRESS)
+					err = ret;
 				decrypted = 0;
 				goto end;
 			}
@@ -1911,11 +1904,7 @@ recv_end:
 		else
 			err = process_rx_list(ctx, msg, &control, 0,
 					      decrypted, true, is_peek);
-		if (err < 0) {
-			tls_err_abort(sk, err);
-			copied = 0;
-			goto end;
-		}
+		decrypted = max(err, 0);
 	}
 
 	copied += decrypted;
@@ -2173,7 +2162,7 @@ void tls_sw_release_resources_rx(struct sock *sk)
 	if (ctx->aead_recv) {
 		kfree_skb(ctx->recv_pkt);
 		ctx->recv_pkt = NULL;
-		skb_queue_purge(&ctx->rx_list);
+		__skb_queue_purge(&ctx->rx_list);
 		crypto_free_aead(ctx->aead_recv);
 		strp_stop(&ctx->strp);
 		/* If tls_sw_strparser_arm() was not called (cleanup paths)