bvc-mahimahi

bvc-mahimahi is a network emulation tools implemented by BVC (Bilibili Video Cloud team). The project is based on MIT mahimahi(http://mahimahi.mit.edu/). In order to support experiment using multiple HTTP protocols such as HTTP2 and HTTP3 (QUIC), BVC replaced the apache server with nginx server on the basis of the original implementation. And by dynamically configuring HTTP network modules in the nginx configuration file, it can support the recording of various websites and replaying the recorded traffic over multiple network protocols, so that will facilitate the developers to do measurement test and tune their web service performance by using the toolkit.

Features

• Record and replay HTTP traffic
• Emulate numerous network conditions
• Use unmodified client applications

Getting Started

Build

./autogen.sh
./configure
make
sudo make install

Dependencies

Name	Typical package
Protocol Buffers	protobuf-compiler, libprotobuf-dev
autotools	autotools-dev
autoreconf	dh-autoreconf
iptables	iptables
pkg-config	pkg-config
dnsmasq	dnsmasq-base
debhelper (>= 9)	debhelper
OpenSSL	libssl-dev, ssl-cert
xcb	libxcb-present-dev
Cairo	libcairo2-dev
Pango	libpango1.0-dev
nginx	tengine-2.3.2
spawn-fcgi	spawn-fcgi-1.6.4
flup	flup-1.0.2
fastcgi	fcgi2

Play examples

• To record traffic from www.bilibili.com in Chromium:

cd mahimahi
mm-webrecord  test
/path-to/Chromium  --ignore-certificate-errors  --ignore-ssl-errors https://www.bilibili.com 

Then you will enter bilibili homepage. You can look through the web pages and click any interested item like video. The toolkit will record all the web HTTP traffic during the whole process until you type ‘exit’ to quit the shell.

exit

• Pre-works for web replay:

Before excuting the replay binary, you should firstly compile and install nginx with its network modules by configuration. In the example, the nginx version that we use is tengine-2.3.2, and the nginx QUIC network module is implemented by our team.

cd tengine-2.3.2
./configure --prefix=/data/tools/nginx --with-http_ssl_module --with-http_v2_module --add-dynamic-module=/path-to/nginx-quic-module
make && make install

You should also create a local root certificate authority (CA) for traffic replaying over HTTP2 protocol. Create the root CA directory:

mkdir  /data/CA
cd /data/CA
mkdir certs crl newcerts private
chmod 700 private
touch index.txt
echo 1000 > serial.txt

Generate the private key of the root CA:

openssl genrsa -aes256 -out /data/CA/private/ca.key.pem 4096
    Enter pass phrase for ca.key.pem:SECRET
    Verifying - Enter pass phrase for ca.key.pem:SECRET
chmod 400 /data/CA/private/ca.key.pem

Create the root CA config file:

cd  /data/CA
cp /etc/ssl/openssl.cnf root_CA.cnf
vim root_CA.cnf

Edit CA config template to ensure the following fields to be properly set:

    [ CA_default ]

        dir = /path-to/mahimahi/CA
        certs = $dir/certs
        private = $dir/private
        certificate = $certs/ca.cert.pem
        private_key = $private/ca.key.pem

    [ usr_cert ]
        basicConstraints=CA:FALSE
        keyUsage = nonRepudiation, digitalSignature, keyEncipherment
        nsComment = "OpenSSL Generated Certificate"
        subjectKeyIdentifier=hash
        authorityKeyIdentifier=keyid,issuer

    [ v3_ca ]
        subjectKeyIdentifier=hash
        authorityKeyIdentifier=keyid:always,issuer
        basicConstraints = CA:true
        keyUsage = cRLSign, keyCertSign

Generate the self-signed root CA certificate:

cd  /data/CA
openssl req -new -x509 -days 3650 -key private/ca.key.pem -sha256 -extensions v3_ca -out certs/ca.cert.pem -config root_CA.cnf

The root CA certificate will be generated and saved in certs/ directory, and will be later used to generate self-signed certificates for each individual web server.

• To replay traffic over HTTP2 protocol in Chromium:

Run webreplay binary and input secret in order to generate certificates to be used by nginx server.

cd mahimahi
mm-webreplay  test

Install self-signed root CA to Chromium: Open Chromium → settings → Privacy and security → security → Manage certificates → Authorities → import /data/CA/cert/ca.cert.pem → restart Chromium

/path-to/Chromium https://www.bilibili.com

• To replay traffic over QUIC protocol in Chromium:

Because Chromium handles QUIC and TLS (over TCP) differently in cert verification, we should explicitly set some flags to force traffic run over QUIC. Especially, we shoud explicitly set hostname and QUIC version for those servers we expect them to server over QUIC, while the rest will serve over HTTP2.

 /path-to/Chromium --quic-host-whitelist=<sitename> --origin-to-force-quic-on=<sitename:port> --quic-version=h3-Q050  https://www.bilibili.com