// To target systems running 4.4.0-1-amd64, compile as follows:
//  stap -v -r 4.4.0-1-amd64 -m h2_spdy_stats h2-spdy-stats.stp -p 4
//
// These packages need to be installed on the production system:
//  systemtap-runtime libssl1.0.0-dbg
//
// Run with:
//  staprun -v h2_spdy_stats.ko

global bin

// ALPN
probe process("/usr/lib/x86_64-linux-gnu/libssl.so.1.0.0").function("SSL_select_next_proto") {
    value  = text_str(user_string($client))

    if (value =~ "h2") {
        if (value =~ "spdy") {
            bin["both"]++
        } else {
            bin["h2"]++
        }
    }
}

// NPN
probe process("/usr/lib/x86_64-linux-gnu/libssl.so.1.0.0").function("SSL_get0_next_proto_negotiated") {
    if ($s->s3->next_proto_neg_seen && $s->next_proto_negotiated_len > 0) {
        value = text_str(user_string_n($s->next_proto_negotiated, $s->next_proto_negotiated_len))
        if (value =~ "http/1.1") {
            bin["npn_http1"]++
        }
        if (value =~ "spdy") {
            bin["spdy"]++
        }
    }
}

probe process("/usr/lib/x86_64-linux-gnu/libssl.so.1.0.0").function("SSL_accept") {
    bin["total"]++
}

probe end {
    foreach (key in bin) {
        printf("%s: %d \n", key, bin[key])
    }
}