ssllatency.bt

#!/usr/bin/env bpftrace
/*
 * ssllatency	Trace SSL/TLS handshake for OpenSSL.
 * 		For Linux, uses bpftrace and eBPF.
 *
 * ssllatency shows handshake latency stats and distribution.
 *
 * Copyright (c) 2021 Tao Xu.
 * Licensed under the Apache License, Version 2.0 (the "License")
 *
 * 17-Dec-2021	Tao Xu	created this.
 */

config = { missing_probes = "ignore" }

BEGIN
{
	printf("Tracing SSL/TLS handshake... Hit Ctrl-C to end.\n");
}

uprobe:libssl:SSL_read,
uprobe:libssl:SSL_write,
uprobe:libssl:SSL_do_handshake
{
	@start_ssl[tid] = nsecs;
	@func_ssl[tid] = func; // store for uretprobe
}

uretprobe:libssl:SSL_read,
uretprobe:libssl:SSL_write,
uretprobe:libssl:SSL_do_handshake
/@start_ssl[tid] != 0/
{
	$lat_us = (nsecs - @start_ssl[tid]) / 1000;
	if ((int8)retval >= 1) {
		@hist[@func_ssl[tid]] = lhist($lat_us, 0, 1000, 200);
		@stat[@func_ssl[tid]] = stats($lat_us);
	} else {
		@histF[@func_ssl[tid]] = lhist($lat_us, 0, 1000, 200);
		@statF[@func_ssl[tid]] = stats($lat_us);
	}
	delete(@start_ssl, tid); delete(@func_ssl, tid);
}

// need debug symbol for ossl local functions
uprobe:libcrypto:rsa_ossl_public_encrypt,
uprobe:libcrypto:rsa_ossl_public_decrypt,
uprobe:libcrypto:rsa_ossl_private_encrypt,
uprobe:libcrypto:rsa_ossl_private_decrypt,
uprobe:libcrypto:RSA_sign,
uprobe:libcrypto:RSA_verify,
uprobe:libcrypto:ossl_ecdsa_sign,
uprobe:libcrypto:ossl_ecdsa_verify,
uprobe:libcrypto:ecdh_simple_compute_key
{
	@start_crypto[tid] = nsecs;
	@func_crypto[tid] = func; // store for uretprobe
}

uretprobe:libcrypto:rsa_ossl_public_encrypt,
uretprobe:libcrypto:rsa_ossl_public_decrypt,
uretprobe:libcrypto:rsa_ossl_private_encrypt,
uretprobe:libcrypto:rsa_ossl_private_decrypt,
uretprobe:libcrypto:RSA_sign,
uretprobe:libcrypto:RSA_verify,
uretprobe:libcrypto:ossl_ecdsa_sign,
uretprobe:libcrypto:ossl_ecdsa_verify,
uretprobe:libcrypto:ecdh_simple_compute_key
/@start_crypto[tid] != 0/
{
	$lat_us = (nsecs - @start_crypto[tid]) / 1000;
	@hist[@func_crypto[tid]] = lhist($lat_us, 0, 1000, 200);
	@stat[@func_crypto[tid]] = stats($lat_us);
	delete(@start_crypto, tid); delete(@func_crypto, tid);
}

END
{
	printf("\nLatency distribution in microsecond:");
}