Merge branch 'tls-rx-refactor-part-1'

Jakub Kicinski says:

====================
tls: rx: random refactoring part 1

TLS Rx refactoring. Part 1 of 3. A couple of features to follow.
====================

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

include/net/strparser.h

@@ -70,6 +70,10 @@ struct sk_skb_cb {
 	 * when dst_reg == src_reg.
 	 */
 	u64 temp_reg;
+	struct tls_msg {
+		u8 control;
+		u8 decrypted;
+	} tls;
 };
 
 static inline struct strp_msg *strp_msg(struct sk_buff *skb)

include/net/tls.h

@@ -64,6 +64,7 @@
 #define TLS_AAD_SPACE_SIZE		13
 
 #define MAX_IV_SIZE			16
+#define TLS_TAG_SIZE			16
 #define TLS_MAX_REC_SEQ_SIZE		8
 
 /* For CCM mode, the full 16-bytes of IV is made of '4' fields of given sizes.
@@ -117,11 +118,6 @@ struct tls_rec {
 	u8 aead_req_ctx[];
 };
 
-struct tls_msg {
-	struct strp_msg rxm;
-	u8 control;
-};
-
 struct tx_work {
 	struct delayed_work work;
 	struct sock *sk;
@@ -152,9 +148,7 @@ struct tls_sw_context_rx {
 	void (*saved_data_ready)(struct sock *sk);
 
 	struct sk_buff *recv_pkt;
-	u8 control;
 	u8 async_capable:1;
-	u8 decrypted:1;
 	atomic_t decrypt_pending;
 	/* protect crypto_wait with decrypt_pending*/
 	spinlock_t decrypt_compl_lock;
@@ -411,7 +405,9 @@ void tls_free_partial_record(struct sock *sk, struct tls_context *ctx);
 
 static inline struct tls_msg *tls_msg(struct sk_buff *skb)
 {
-	return (struct tls_msg *)strp_msg(skb);
+	struct sk_skb_cb *scb = (struct sk_skb_cb *)skb->cb;
+
+	return &scb->tls;
 }
 
 static inline bool tls_is_partially_sent_record(struct tls_context *ctx)

net/tls/tls_device.c

@@ -962,11 +962,9 @@ int tls_device_decrypted(struct sock *sk, struct tls_context *tls_ctx,
 				   tls_ctx->rx.rec_seq, rxm->full_len,
 				   is_encrypted, is_decrypted);
 
-	ctx->sw.decrypted |= is_decrypted;
-
 	if (unlikely(test_bit(TLS_RX_DEV_DEGRADED, &tls_ctx->flags))) {
 		if (likely(is_encrypted || is_decrypted))
-			return 0;
+			return is_decrypted;
 
 		/* After tls_device_down disables the offload, the next SKB will
 		 * likely have initial fragments decrypted, and final ones not
@@ -981,7 +979,7 @@ int tls_device_decrypted(struct sock *sk, struct tls_context *tls_ctx,
 	 */
 	if (is_decrypted) {
 		ctx->resync_nh_reset = 1;
-		return 0;
+		return is_decrypted;
 	}
 	if (is_encrypted) {
 		tls_device_core_ctrl_rx_resync(tls_ctx, ctx, sk, skb);

net/tls/tls_sw.c

@@ -128,32 +128,31 @@ static int skb_nsg(struct sk_buff *skb, int offset, int len)
         return __skb_nsg(skb, offset, len, 0);
 }
 
-static int padding_length(struct tls_sw_context_rx *ctx,
-			  struct tls_prot_info *prot, struct sk_buff *skb)
+static int padding_length(struct tls_prot_info *prot, struct sk_buff *skb)
 {
 	struct strp_msg *rxm = strp_msg(skb);
+	struct tls_msg *tlm = tls_msg(skb);
 	int sub = 0;
 
 	/* Determine zero-padding length */
 	if (prot->version == TLS_1_3_VERSION) {
+		int offset = rxm->full_len - TLS_TAG_SIZE - 1;
 		char content_type = 0;
 		int err;
-		int back = 17;
 
 		while (content_type == 0) {
-			if (back > rxm->full_len - prot->prepend_size)
+			if (offset < prot->prepend_size)
 				return -EBADMSG;
-			err = skb_copy_bits(skb,
-					    rxm->offset + rxm->full_len - back,
+			err = skb_copy_bits(skb, rxm->offset + offset,
 					    &content_type, 1);
 			if (err)
 				return err;
 			if (content_type)
 				break;
 			sub++;
-			back++;
+			offset--;
 		}
-		ctx->control = content_type;
+		tlm->control = content_type;
 	}
 	return sub;
 }
@@ -187,7 +186,7 @@ static void tls_decrypt_done(struct crypto_async_request *req, int err)
 		struct strp_msg *rxm = strp_msg(skb);
 		int pad;
 
-		pad = padding_length(ctx, prot, skb);
+		pad = padding_length(prot, skb);
 		if (pad < 0) {
 			ctx->async_wait.err = pad;
 			tls_err_abort(skb->sk, pad);
@@ -1421,6 +1420,7 @@ static int decrypt_internal(struct sock *sk, struct sk_buff *skb,
 	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 = strp_msg(skb);
+	struct tls_msg *tlm = tls_msg(skb);
 	int n_sgin, n_sgout, nsg, mem_size, aead_size, err, pages = 0;
 	struct aead_request *aead_req;
 	struct sk_buff *unused;
@@ -1505,7 +1505,7 @@ static int decrypt_internal(struct sock *sk, struct sk_buff *skb,
 	/* Prepare AAD */
 	tls_make_aad(aad, rxm->full_len - prot->overhead_size +
 		     prot->tail_size,
-		     tls_ctx->rx.rec_seq, ctx->control, prot);
+		     tls_ctx->rx.rec_seq, tlm->control, prot);
 
 	/* Prepare sgin */
 	sg_init_table(sgin, n_sgin);
@@ -1561,50 +1561,48 @@ static int decrypt_skb_update(struct sock *sk, struct sk_buff *skb,
 			      bool async)
 {
 	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 = strp_msg(skb);
-	int pad, err = 0;
+	struct tls_msg *tlm = tls_msg(skb);
+	int pad, err;
 
-	if (!ctx->decrypted) {
-		if (tls_ctx->rx_conf == TLS_HW) {
-			err = tls_device_decrypted(sk, tls_ctx, skb, rxm);
-			if (err < 0)
-				return err;
-		}
-
-		/* Still not decrypted after tls_device */
-		if (!ctx->decrypted) {
-			err = decrypt_internal(sk, skb, dest, NULL, chunk, zc,
-					       async);
-			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);
-				return err;
-			}
-		} else {
-			*zc = false;
-		}
-
-		pad = padding_length(ctx, prot, skb);
-		if (pad < 0)
-			return pad;
-
-		rxm->full_len -= pad;
-		rxm->offset += prot->prepend_size;
-		rxm->full_len -= prot->overhead_size;
-		tls_advance_record_sn(sk, prot, &tls_ctx->rx);
-		ctx->decrypted = 1;
-		ctx->saved_data_ready(sk);
-	} else {
+	if (tlm->decrypted) {
 		*zc = false;
+		return 0;
 	}
 
-	return err;
+	if (tls_ctx->rx_conf == TLS_HW) {
+		err = tls_device_decrypted(sk, tls_ctx, skb, rxm);
+		if (err < 0)
+			return err;
+		if (err > 0) {
+			tlm->decrypted = 1;
+			*zc = false;
+			goto decrypt_done;
+		}
+	}
+
+	err = decrypt_internal(sk, skb, dest, NULL, chunk, zc, async);
+	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);
+		return err;
+	}
+
+decrypt_done:
+	pad = padding_length(prot, skb);
+	if (pad < 0)
+		return pad;
+
+	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;
+
+	return 0;
 }
 
 int decrypt_skb(struct sock *sk, struct sk_buff *skb,
@@ -1760,6 +1758,7 @@ int tls_sw_recvmsg(struct sock *sk,
 	struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
 	struct tls_prot_info *prot = &tls_ctx->prot_info;
 	struct sk_psock *psock;
+	int num_async, pending;
 	unsigned char control = 0;
 	ssize_t decrypted = 0;
 	struct strp_msg *rxm;
@@ -1772,8 +1771,6 @@ int tls_sw_recvmsg(struct sock *sk,
 	bool is_kvec = iov_iter_is_kvec(&msg->msg_iter);
 	bool is_peek = flags & MSG_PEEK;
 	bool bpf_strp_enabled;
-	int num_async = 0;
-	int pending;
 
 	flags |= nonblock;
 
@@ -1790,17 +1787,18 @@ int tls_sw_recvmsg(struct sock *sk,
 	if (err < 0) {
 		tls_err_abort(sk, err);
 		goto end;
-	} else {
-		copied = err;
 	}
 
+	copied = err;
 	if (len <= copied)
-		goto recv_end;
+		goto end;
 
 	target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
 	len = len - copied;
 	timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
 
+	decrypted = 0;
+	num_async = 0;
 	while (len && (decrypted + copied < target || ctx->recv_pkt)) {
 		bool retain_skb = false;
 		bool zc = false;
@@ -1822,26 +1820,21 @@ int tls_sw_recvmsg(struct sock *sk,
 				}
 			}
 			goto recv_end;
-		} else {
-			tlm = tls_msg(skb);
-			if (prot->version == TLS_1_3_VERSION)
-				tlm->control = 0;
-			else
-				tlm->control = ctx->control;
 		}
 
 		rxm = strp_msg(skb);
+		tlm = tls_msg(skb);
 
 		to_decrypt = rxm->full_len - prot->overhead_size;
 
 		if (to_decrypt <= len && !is_kvec && !is_peek &&
-		    ctx->control == TLS_RECORD_TYPE_DATA &&
+		    tlm->control == TLS_RECORD_TYPE_DATA &&
 		    prot->version != TLS_1_3_VERSION &&
 		    !bpf_strp_enabled)
 			zc = true;
 
 		/* Do not use async mode if record is non-data */
-		if (ctx->control == TLS_RECORD_TYPE_DATA && !bpf_strp_enabled)
+		if (tlm->control == TLS_RECORD_TYPE_DATA && !bpf_strp_enabled)
 			async_capable = ctx->async_capable;
 		else
 			async_capable = false;
@@ -1856,8 +1849,6 @@ int tls_sw_recvmsg(struct sock *sk,
 		if (err == -EINPROGRESS) {
 			async = true;
 			num_async++;
-		} else if (prot->version == TLS_1_3_VERSION) {
-			tlm->control = ctx->control;
 		}
 
 		/* If the type of records being processed is not known yet,
@@ -2005,6 +1996,7 @@ ssize_t tls_sw_splice_read(struct socket *sock,  loff_t *ppos,
 	struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
 	struct strp_msg *rxm = NULL;
 	struct sock *sk = sock->sk;
+	struct tls_msg *tlm;
 	struct sk_buff *skb;
 	ssize_t copied = 0;
 	bool from_queue;
@@ -2033,14 +2025,15 @@ ssize_t tls_sw_splice_read(struct socket *sock,  loff_t *ppos,
 		}
 	}
 
+	rxm = strp_msg(skb);
+	tlm = tls_msg(skb);
+
 	/* splice does not support reading control messages */
-	if (ctx->control != TLS_RECORD_TYPE_DATA) {
+	if (tlm->control != TLS_RECORD_TYPE_DATA) {
 		err = -EINVAL;
 		goto splice_read_end;
 	}
 
-	rxm = strp_msg(skb);
-
 	chunk = min_t(unsigned int, rxm->full_len, len);
 	copied = skb_splice_bits(skb, sk, rxm->offset, pipe, chunk, flags);
 	if (copied < 0)
@@ -2084,10 +2077,10 @@ bool tls_sw_sock_is_readable(struct sock *sk)
 static int tls_read_size(struct strparser *strp, struct sk_buff *skb)
 {
 	struct tls_context *tls_ctx = tls_get_ctx(strp->sk);
-	struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
 	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;
@@ -2104,11 +2097,11 @@ static int tls_read_size(struct strparser *strp, struct sk_buff *skb)
 
 	/* Linearize header to local buffer */
 	ret = skb_copy_bits(skb, rxm->offset, header, prot->prepend_size);
-
 	if (ret < 0)
 		goto read_failure;
 
-	ctx->control = header[0];
+	tlm->decrypted = 0;
+	tlm->control = header[0];
 
 	data_len = ((header[4] & 0xFF) | (header[3] << 8));
 
@@ -2149,8 +2142,6 @@ static void tls_queue(struct strparser *strp, struct sk_buff *skb)
 	struct tls_context *tls_ctx = tls_get_ctx(strp->sk);
 	struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
 
-	ctx->decrypted = 0;
-
 	ctx->recv_pkt = skb;
 	strp_pause(strp);
 
@@ -2501,7 +2492,7 @@ int tls_set_sw_offload(struct sock *sk, struct tls_context *ctx, int tx)
 
 	/* Sanity-check the sizes for stack allocations. */
 	if (iv_size > MAX_IV_SIZE || nonce_size > MAX_IV_SIZE ||
-	    rec_seq_size > TLS_MAX_REC_SEQ_SIZE) {
+	    rec_seq_size > TLS_MAX_REC_SEQ_SIZE || tag_size != TLS_TAG_SIZE) {
 		rc = -EINVAL;
 		goto free_priv;
 	}