net/tls: add TlsDeviceRxResync statistic

Add a statistic for number of RX resyncs sent down to the NIC.
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Documentation/networking/tls.rst

@@ -236,3 +236,6 @@ TLS implementation exposes the following per-namespace statistics
 
 - ``TlsDecryptError`` -
   record decryption failed (e.g. due to incorrect authentication tag)
+
+- ``TlsDeviceRxResync`` -
+  number of RX resyncs sent to NICs handling cryptography

include/uapi/linux/snmp.h

@@ -336,6 +336,7 @@ enum
 	LINUX_MIB_TLSTXDEVICE,			/* TlsTxDevice */
 	LINUX_MIB_TLSRXDEVICE,			/* TlsRxDevice */
 	LINUX_MIB_TLSDECRYPTERROR,		/* TlsDecryptError */
+	LINUX_MIB_TLSRXDEVICERESYNC,		/* TlsRxDeviceResync */
 	__LINUX_MIB_TLSMAX
 };
 

net/tls/tls_device.c

@@ -661,6 +661,7 @@ static void tls_device_resync_rx(struct tls_context *tls_ctx,
 		netdev->tlsdev_ops->tls_dev_resync(netdev, sk, seq, rcd_sn,
 						   TLS_OFFLOAD_CTX_DIR_RX);
 	clear_bit_unlock(TLS_RX_SYNC_RUNNING, &tls_ctx->flags);
+	TLS_INC_STATS(sock_net(sk), LINUX_MIB_TLSRXDEVICERESYNC);
 }
 
 void tls_device_rx_resync_new_rec(struct sock *sk, u32 rcd_len, u32 seq)

net/tls/tls_proc.c

@@ -16,6 +16,7 @@ static const struct snmp_mib tls_mib_list[] = {
 	SNMP_MIB_ITEM("TlsTxDevice", LINUX_MIB_TLSTXDEVICE),
 	SNMP_MIB_ITEM("TlsRxDevice", LINUX_MIB_TLSRXDEVICE),
 	SNMP_MIB_ITEM("TlsDecryptError", LINUX_MIB_TLSDECRYPTERROR),
+	SNMP_MIB_ITEM("TlsRxDeviceResync", LINUX_MIB_TLSRXDEVICERESYNC),
 	SNMP_MIB_SENTINEL
 };