Merge branch 'tls-RX'

Dave Watson says:

====================
TLS Rx

TLS tcp socket RX implementation, to match existing TX code.

This patchset completes the software TLS socket, allowing full
bi-directional communication over TLS using normal socket syscalls,
after the handshake has been done in userspace.  Only the symmetric
encryption is done in the kernel.

This allows usage of TLS sockets from within the kernel (for example
with network block device, or from bpf).  Performance can be better
than userspace, with appropriate crypto routines [1].

sk->sk_socket->ops must be overridden to implement splice_read and
poll, but otherwise the interface & implementation match TX closely.
strparser is used to parse TLS framing on receive.

There are Openssl RX patches that work with this interface [2], as
well as a testing tool using the socket interface directly (without
cmsg support) [3].  An example tcp socket setup is:

  // Normal tcp socket connect/accept, and TLS handshake
  // using any TLS library.
  setsockopt(sock, SOL_TCP, TCP_ULP, "tls", sizeof("tls"));

  struct tls12_crypto_info_aes_gcm_128 crypto_info_rx;
  // Fill in crypto_info based on negotiated keys.

  setsockopt(sock, SOL_TLS, TLS_RX, &crypto_info, sizeof(crypto_info_rx));
  // You can optionally TLX_TX as well.

  char buffer[16384];
  int ret = recv(sock, buffer, 16384);

  // cmsg can be received using recvmsg and a msg_control
  // of type TLS_GET_RECORD_TYPE will be set.

V1 -> V2

* For too-small framing errors, return EBADMSG, to match openssl error
  code semantics.  Docs and commit logs about this also updated.

RFC -> V1

* Refactor 'tx' variable names to drop tx
* Error return codes changed per discussion
* Only call skb_cow_data based on in-place decryption,
  drop unnecessary frag list check.

[1] Recent crypto patchset to remove copies, resulting in optimally
    zero copies vs. userspace's one, vs. previous kernel's two.

https://marc.info/?l=linux-crypto-vger&m=151931242406416&w=2

[2] https://github.com/Mellanox/openssl/commits/tls_rx2

[3] https://github.com/ktls/af_ktls-tool/tree/RX
====================

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

1 files changed, 44 insertions, 17 deletions

diff --git a/include/net/tls.h b/include/net/tls.h
index 4913430ab807..437a746300bf 100644
--- a/include/net/tls.h
+++ b/include/net/tls.h
@@ -40,6 +40,7 @@
 #include <linux/socket.h>
 #include <linux/tcp.h>
 #include <net/tcp.h>
+#include <net/strparser.h>
 
 #include <uapi/linux/tls.h>
 
@@ -58,8 +59,18 @@
 
 struct tls_sw_context {
 	struct crypto_aead *aead_send;
+	struct crypto_aead *aead_recv;
 	struct crypto_wait async_wait;
 
+	/* Receive context */
+	struct strparser strp;
+	void (*saved_data_ready)(struct sock *sk);
+	unsigned int (*sk_poll)(struct file *file, struct socket *sock,
+				struct poll_table_struct *wait);
+	struct sk_buff *recv_pkt;
+	u8 control;
+	bool decrypted;
+
 	/* Sending context */
 	char aad_space[TLS_AAD_SPACE_SIZE];
 
@@ -81,23 +92,32 @@ enum {
 	TLS_PENDING_CLOSED_RECORD
 };
 
+struct cipher_context {
+	u16 prepend_size;
+	u16 tag_size;
+	u16 overhead_size;
+	u16 iv_size;
+	char *iv;
+	u16 rec_seq_size;
+	char *rec_seq;
+};
+
 struct tls_context {
 	union {
 		struct tls_crypto_info crypto_send;
 		struct tls12_crypto_info_aes_gcm_128 crypto_send_aes_gcm_128;
 	};
+	union {
+		struct tls_crypto_info crypto_recv;
+		struct tls12_crypto_info_aes_gcm_128 crypto_recv_aes_gcm_128;
+	};
 
 	void *priv_ctx;
 
-	u8 tx_conf:2;
+	u8 conf:2;
 
-	u16 prepend_size;
-	u16 tag_size;
-	u16 overhead_size;
-	u16 iv_size;
-	char *iv;
-	u16 rec_seq_size;
-	char *rec_seq;
+	struct cipher_context tx;
+	struct cipher_context rx;
 
 	struct scatterlist *partially_sent_record;
 	u16 partially_sent_offset;
@@ -124,12 +144,19 @@ int tls_sk_attach(struct sock *sk, int optname, char __user *optval,
 		  unsigned int optlen);
 
 
-int tls_set_sw_offload(struct sock *sk, struct tls_context *ctx);
+int tls_set_sw_offload(struct sock *sk, struct tls_context *ctx, int tx);
 int tls_sw_sendmsg(struct sock *sk, struct msghdr *msg, size_t size);
 int tls_sw_sendpage(struct sock *sk, struct page *page,
 		    int offset, size_t size, int flags);
 void tls_sw_close(struct sock *sk, long timeout);
-void tls_sw_free_tx_resources(struct sock *sk);
+void tls_sw_free_resources(struct sock *sk);
+int tls_sw_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
+		   int nonblock, int flags, int *addr_len);
+unsigned int tls_sw_poll(struct file *file, struct socket *sock,
+			 struct poll_table_struct *wait);
+ssize_t tls_sw_splice_read(struct socket *sock, loff_t *ppos,
+			   struct pipe_inode_info *pipe,
+			   size_t len, unsigned int flags);
 
 void tls_sk_destruct(struct sock *sk, struct tls_context *ctx);
 void tls_icsk_clean_acked(struct sock *sk);
@@ -170,9 +197,9 @@ static inline bool tls_is_pending_open_record(struct tls_context *tls_ctx)
 	return tls_ctx->pending_open_record_frags;
 }
 
-static inline void tls_err_abort(struct sock *sk)
+static inline void tls_err_abort(struct sock *sk, int err)
 {
-	sk->sk_err = EBADMSG;
+	sk->sk_err = err;
 	sk->sk_error_report(sk);
 }
 
@@ -190,10 +217,10 @@ static inline bool tls_bigint_increment(unsigned char *seq, int len)
 }
 
 static inline void tls_advance_record_sn(struct sock *sk,
-					 struct tls_context *ctx)
+					 struct cipher_context *ctx)
 {
 	if (tls_bigint_increment(ctx->rec_seq, ctx->rec_seq_size))
-		tls_err_abort(sk);
+		tls_err_abort(sk, EBADMSG);
 	tls_bigint_increment(ctx->iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE,
 			     ctx->iv_size);
 }
@@ -203,9 +230,9 @@ static inline void tls_fill_prepend(struct tls_context *ctx,
 			     size_t plaintext_len,
 			     unsigned char record_type)
 {
-	size_t pkt_len, iv_size = ctx->iv_size;
+	size_t pkt_len, iv_size = ctx->tx.iv_size;
 
-	pkt_len = plaintext_len + iv_size + ctx->tag_size;
+	pkt_len = plaintext_len + iv_size + ctx->tx.tag_size;
 
 	/* we cover nonce explicit here as well, so buf should be of
 	 * size KTLS_DTLS_HEADER_SIZE + KTLS_DTLS_NONCE_EXPLICIT_SIZE
@@ -217,7 +244,7 @@ static inline void tls_fill_prepend(struct tls_context *ctx,
 	buf[3] = pkt_len >> 8;
 	buf[4] = pkt_len & 0xFF;
 	memcpy(buf + TLS_NONCE_OFFSET,
-	       ctx->iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE, iv_size);
+	       ctx->tx.iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE, iv_size);
 }
 
 static inline void tls_make_aad(char *buf,