Linux Archive
OpenVPNを、Ubuntu 10.04で立ててみました。この前のクリスマスだったか、OpenVPNのサービスを動かしていたVMをオペミスでESXiのDatastoreごと吹っ飛ばして以来、ずっと止まってしまっていたので、そのリベンジです。Ubuntu 10.04には最新のOpenVPN 2.1のパッケージが入っており、aptitudeで依存関係のあるパッケージもまとめて入れることができます。また、10.04はLTS(Long Time Support)版でもあり、OpenVPNを安定して運用するには便利なディストリとなっていました。
さて、そもそもOpenVPNとは何かというと、その名の通り、オープンソースで開発が進められているVPNデーモンです。L2、L3のどちらでのVPNも提供しています。今回は、L2でのVPNである、bridge接続でのVPNについてを扱います。
まずはネットワーク図をば。
今回はこんなネットワークを組みました。自宅のホストにはすべてプライベートアドレスがついていて、ルータのWAN側のポートにのみグローバルIPアドレスがついています。ちなみにアクセス回線はADSL、どこにでもあるような普通のホームネットワークですね。唯一異なっているのは、プライベートアドレスに10.10.0.0/16のサブネットを利用している点。出先のネットワークとなるべく被らないように、という理由です。「10.10.0.0/16は僕のアドレスなので使わないでください!」(笑)というやつです。 OpenVPNのクライアントとなるのはラップトップ。大学やバイト先などから家に接続することを想定しています。この時、ラップトップには有線LANや無線LANのネットワークインターフェイスとは別に、TAPインターフェイスという仮想的なインターフェイスがつき、このインターフェイスの先で直接自宅ネットワークのサブネットに仮想的に接続することになります。図の、点線部分がそれにあたります。10.10/16宛てのパケットはTAPインターフェイスから出ていき、それ以外のパケットは有線LANなり無線LANなりから出ていくというマルチホーム状態を構成しました。
参考までに自分の環境のconf晒し。
################################################# # Sample OpenVPN 2.0 config file for # # multi-client server. # # # # This file is for the server side # # of a many-clients <-> one-server # # OpenVPN configuration. # # # # OpenVPN also supports # # single-machine <-> single-machine # # configurations (See the Examples page # # on the web site for more info). # # # # This config should work on Windows # # or Linux/BSD systems. Remember on # # Windows to quote pathnames and use # # double backslashes, e.g.: # # "C:\\Program Files\\OpenVPN\\config\\foo.key" # # # # Comments are preceded with '#' or ';' # ################################################# # Which local IP address should OpenVPN # listen on? (optional) local 10.10.11.4 # Which TCP/UDP port should OpenVPN listen on? # If you want to run multiple OpenVPN instances # on the same machine, use a different port # number for each one. You will need to # open up this port on your firewall. port 1194 # TCP or UDP server? ;proto tcp proto udp # "dev tun" will create a routed IP tunnel, # "dev tap" will create an ethernet tunnel. # Use "dev tap0" if you are ethernet bridging # and have precreated a tap0 virtual interface # and bridged it with your ethernet interface. # If you want to control access policies # over the VPN, you must create firewall # rules for the the TUN/TAP interface. # On non-Windows systems, you can give # an explicit unit number, such as tun0. # On Windows, use "dev-node" for this. # On most systems, the VPN will not function # unless you partially or fully disable # the firewall for the TUN/TAP interface. dev tap0 ;dev tun # Windows needs the TAP-Win32 adapter name # from the Network Connections panel if you # have more than one. On XP SP2 or higher, # you may need to selectively disable the # Windows firewall for the TAP adapter. # Non-Windows systems usually don't need this. ;dev-node tap0 # SSL/TLS root certificate (ca), certificate # (cert), and private key (key). Each client # and the server must have their own cert and # key file. The server and all clients will # use the same ca file. # # See the "easy-rsa" directory for a series # of scripts for generating RSA certificates # and private keys. Remember to use # a unique Common Name for the server # and each of the client certificates. # # Any X509 key management system can be used. # OpenVPN can also use a PKCS #12 formatted key file # (see "pkcs12" directive in man page). ca /etc/openvpn/ca.crt cert /etc/openvpn/ambient.crt key /etc/openvpn/ambient.key # This file should be kept secret # Diffie hellman parameters. # Generate your own with: # openssl dhparam -out dh1024.pem 1024 # Substitute 2048 for 1024 if you are using # 2048 bit keys. dh dh2048.pem # Configure server mode and supply a VPN subnet # for OpenVPN to draw client addresses from. # The server will take 10.8.0.1 for itself, # the rest will be made available to clients. # Each client will be able to reach the server # on 10.8.0.1. Comment this line out if you are # ethernet bridging. See the man page for more info. ; server 10.8.0.0 255.255.255.0 # Maintain a record of client <-> virtual IP address # associations in this file. If OpenVPN goes down or # is restarted, reconnecting clients can be assigned # the same virtual IP address from the pool that was # previously assigned. ifconfig-pool-persist ipp.txt # Configure server mode for ethernet bridging. # You must first use your OS's bridging capability # to bridge the TAP interface with the ethernet # NIC interface. Then you must manually set the # IP/netmask on the bridge interface, here we # assume 10.8.0.4/255.255.255.0. Finally we # must set aside an IP range in this subnet # (start=10.8.0.50 end=10.8.0.100) to allocate # to connecting clients. Leave this line commented # out unless you are ethernet bridging. server-bridge 10.10.11.3 255.255.0.0 10.10.90.1 10.10.90.254 # Configure server mode for ethernet bridging # using a DHCP-proxy, where clients talk # to the OpenVPN server-side DHCP server # to receive their IP address allocation # and DNS server addresses. You must first use # your OS's bridging capability to bridge the TAP # interface with the ethernet NIC interface. # Note: this mode only works on clients (such as # Windows), where the client-side TAP adapter is # bound to a DHCP client. ;server-bridge # Push routes to the client to allow it # to reach other private subnets behind # the server. Remember that these # private subnets will also need # to know to route the OpenVPN client # address pool (10.8.0.0/255.255.255.0) # back to the OpenVPN server. push "route 10.10.0.0 255.255.0.0" ;push "route 192.168.10.0 255.255.255.0" ;push "route 192.168.20.0 255.255.255.0" # To assign specific IP addresses to specific # clients or if a connecting client has a private # subnet behind it that should also have VPN access, # use the subdirectory "ccd" for client-specific # configuration files (see man page for more info). # EXAMPLE: Suppose the client # having the certificate common name "Thelonious" # also has a small subnet behind his connecting # machine, such as 192.168.40.128/255.255.255.248. # First, uncomment out these lines: ;client-config-dir ccd ;route 192.168.40.128 255.255.255.248 # Then create a file ccd/Thelonious with this line: # iroute 192.168.40.128 255.255.255.248 # This will allow Thelonious' private subnet to # access the VPN. This example will only work # if you are routing, not bridging, i.e. you are # using "dev tun" and "server" directives. # EXAMPLE: Suppose you want to give # Thelonious a fixed VPN IP address of 10.9.0.1. # First uncomment out these lines: ;client-config-dir ccd ;route 10.9.0.0 255.255.255.252 # Then add this line to ccd/Thelonious: # ifconfig-push 10.9.0.1 10.9.0.2 # Suppose that you want to enable different # firewall access policies for different groups # of clients. There are two methods: # (1) Run multiple OpenVPN daemons, one for each # group, and firewall the TUN/TAP interface # for each group/daemon appropriately. # (2) (Advanced) Create a script to dynamically # modify the firewall in response to access # from different clients. See man # page for more info on learn-address script. ;learn-address ./script # If enabled, this directive will configure # all clients to redirect their default # network gateway through the VPN, causing # all IP traffic such as web browsing and # and DNS lookups to go through the VPN # (The OpenVPN server machine may need to NAT # or bridge the TUN/TAP interface to the internet # in order for this to work properly). ;push "redirect-gateway def1 bypass-dhcp" # Certain Windows-specific network settings # can be pushed to clients, such as DNS # or WINS server addresses. CAVEAT: # http://openvpn.net/faq.html#dhcpcaveats # The addresses below refer to the public # DNS servers provided by opendns.com. ;push "dhcp-option DNS 208.67.222.222" ;push "dhcp-option DNS 208.67.220.220" # Uncomment this directive to allow different # clients to be able to "see" each other. # By default, clients will only see the server. # To force clients to only see the server, you # will also need to appropriately firewall the # server's TUN/TAP interface. ;client-to-client # Uncomment this directive if multiple clients # might connect with the same certificate/key # files or common names. This is recommended # only for testing purposes. For production use, # each client should have its own certificate/key # pair. # # IF YOU HAVE NOT GENERATED INDIVIDUAL # CERTIFICATE/KEY PAIRS FOR EACH CLIENT, # EACH HAVING ITS OWN UNIQUE "COMMON NAME", # UNCOMMENT THIS LINE OUT. ;duplicate-cn # The keepalive directive causes ping-like # messages to be sent back and forth over # the link so that each side knows when # the other side has gone down. # Ping every 10 seconds, assume that remote # peer is down if no ping received during # a 120 second time period. keepalive 10 120 # For extra security beyond that provided # by SSL/TLS, create an "HMAC firewall" # to help block DoS attacks and UDP port flooding. # # Generate with: # openvpn --genkey --secret ta.key # # The server and each client must have # a copy of this key. # The second parameter should be '0' # on the server and '1' on the clients. ;tls-auth ta.key 0 # This file is secret # Select a cryptographic cipher. # This config item must be copied to # the client config file as well. ;cipher BF-CBC # Blowfish (default) ;cipher AES-128-CBC # AES ;cipher DES-EDE3-CBC # Triple-DES # Enable compression on the VPN link. # If you enable it here, you must also # enable it in the client config file. comp-lzo # The maximum number of concurrently connected # clients we want to allow. ;max-clients 100 # It's a good idea to reduce the OpenVPN # daemon's privileges after initialization. # # You can uncomment this out on # non-Windows systems. user nobody group nogroup # The persist options will try to avoid # accessing certain resources on restart # that may no longer be accessible because # of the privilege downgrade. persist-key persist-tun # Output a short status file showing # current connections, truncated # and rewritten every minute. status openvpn-status.log # By default, log messages will go to the syslog (or # on Windows, if running as a service, they will go to # the "\Program Files\OpenVPN\log" directory). # Use log or log-append to override this default. # "log" will truncate the log file on OpenVPN startup, # while "log-append" will append to it. Use one # or the other (but not both). ;log openvpn.log ;log-append openvpn.log # Set the appropriate level of log # file verbosity. # # 0 is silent, except for fatal errors # 4 is reasonable for general usage # 5 and 6 can help to debug connection problems # 9 is extremely verbose verb 3 # Silence repeating messages. At most 20 # sequential messages of the same message # category will be output to the log. ;mute 20 #Autoconfigure scripts up "./openvpn-startup" down "./openvpn-shutdown"
############################################## # Sample client-side OpenVPN 2.0 config file # # for connecting to multi-client server. # # # # This configuration can be used by multiple # # clients, however each client should have # # its own cert and key files. # # # # On Windows, you might want to rename this # # file so it has a .ovpn extension # ############################################## # Specify that we are a client and that we # will be pulling certain config file directives # from the server. client # Use the same setting as you are using on # the server. # On most systems, the VPN will not function # unless you partially or fully disable # the firewall for the TUN/TAP interface. dev tap ;dev tun # Windows needs the TAP-Win32 adapter name # from the Network Connections panel # if you have more than one. On XP SP2, # you may need to disable the firewall # for the TAP adapter. ;dev-node Tap # Are we connecting to a TCP or # UDP server? Use the same setting as # on the server. ;proto tcp proto udp # The hostname/IP and port of the server. # You can have multiple remote entries # to load balance between the servers. remote im3.sharplab.net 1194 ;remote my-server-2 1194 # Choose a random host from the remote # list for load-balancing. Otherwise # try hosts in the order specified. ;remote-random # Keep trying indefinitely to resolve the # host name of the OpenVPN server. Very useful # on machines which are not permanently connected # to the internet such as laptops. resolv-retry infinite # Most clients don't need to bind to # a specific local port number. nobind # Downgrade privileges after initialization (non-Windows only) ;user nobody ;group nogroup # Try to preserve some state across restarts. persist-key persist-tun # If you are connecting through an # HTTP proxy to reach the actual OpenVPN # server, put the proxy server/IP and # port number here. See the man page # if your proxy server requires # authentication. ;http-proxy-retry # retry on connection failures ;http-proxy [proxy server] [proxy port #] # Wireless networks often produce a lot # of duplicate packets. Set this flag # to silence duplicate packet warnings. ;mute-replay-warnings # SSL/TLS parms. # See the server config file for more # description. It's best to use # a separate .crt/.key file pair # for each client. A single ca # file can be used for all clients. ca ca.crt cert tpx201s.crt key tpx201s.key # Verify server certificate by checking # that the certicate has the nsCertType # field set to "server". This is an # important precaution to protect against # a potential attack discussed here: # http://openvpn.net/howto.html#mitm # # To use this feature, you will need to generate # your server certificates with the nsCertType # field set to "server". The build-key-server # script in the easy-rsa folder will do this. ns-cert-type server # If a tls-auth key is used on the server # then every client must also have the key. ;tls-auth ta.key 1 # Select a cryptographic cipher. # If the cipher option is used on the server # then you must also specify it here. ;cipher x # Enable compression on the VPN link. # Don't enable this unless it is also # enabled in the server config file. comp-lzo
やむにやまれぬ事情でGTKを勉強中です。。とりあえずHello world。右のスクリーンショットはWindowsっぽいですが、テーマをいじっているだけで正真正銘のUbuntu上での表示です。 Hello world表示するだけでちょこちょこコーディングしなければいけないのがめどい。。デザイナがあるらしいので、使い方を早くマスターしないと。。
#include <stdio.h>
#include <gtk/gtk.h>
static gboolean my_delete_event_handler(GtkWidget *widget,
GdkEvent *event,
gpointer data)
{
g_print("delete!\n");
return FALSE;
}
static void my_destroy_handler( GtkWidget *widget,
gpointer data)
{
g_print("destry!\n");
gtk_main_quit();
}
int main(int argc, char *argv[]){
GtkWidget *window;
GtkWidget *bbox;
GtkWidget *button;
gtk_init(&argc, &argv);
window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
bbox = gtk_hbutton_box_new();
button = gtk_button_new();
gtk_button_set_label(GTK_BUTTON(button), "Hello GTK!");
g_signal_connect( G_OBJECT(window), "delete-event",
G_CALLBACK(my_delete_event_handler),
NULL);
g_signal_connect( G_OBJECT(window), "destroy",
G_CALLBACK(my_destroy_handler),
NULL);
gtk_container_add(GTK_CONTAINER(bbox), button);
gtk_container_add(GTK_CONTAINER(window), bbox);
gtk_widget_show_all(window);
gtk_main();
return 0;
}
Virtual PCに入れるだけでは飽き足らず、Windows 7 RCをデスクトップPCやラップトップPCにもインストールしている今日この頃。
ただ、入れてみたはいいものの、デュアルブートでUbuntuが入っているPCに後から入れたものだから、MBRが書き換えられてGRUBに入れなくなってしまったのでその対処法メモ。
- UbuntuのLive CDでとりあえず起動
- 今回自分は内蔵光学ドライブが壊れていたのでUSB接続の光学ドライブを使用したのですが、この場合BIOSで外部デバイスからのブートを有効にする必要があったので注意
- GNOMEパーティションエディタなりでUbuntuがインストールされているパーティションを特定。
- 再起動してLive CDの起動オプションをfile=/cdrom/preseed/ubuntu.seed boot=casper initrd=/casper/initrd.gz となっているところで”boot=casper"の部分を”root=/dev/sda1" 等環境に合わせて書き換えて起動。(参考:Goro&Ubuntu GRUBの再インストール)
- 起動できたらGRUB復活の呪文。 sudo grub-install /dev/sda
Linuxややこしいなぁ。
この前払い下げられてきた家族共用PCを再利用するため、自分の扱えるドメインをLinuxにも拡張するため、そして物欲を満たすため(笑)に、最近PC周りの環境を再整備中。今回のエントリはそのメモ。
さて、払い下げてきたるはFMV CE18B。自分が中二の頃からある六年選手の古参PCで、CPUはAthlon 1800+、メモリ256MB、HDD 80GBのポンコツPC。ここ二年位はほとんど稼働していなかったPCだけれども、遊んでいるデスクトップPCはこれしかなかったので今回これにUbuntuを入れて実験機にしてみることにした。Ubuntuを入れる前に、ひとまず残っているデータの吸い出しを試みたのだが、吸い出そうにもXPの動作が重すぎて話にならなかったので、とりあえずメモリを512MB分増設。768MBとした上で「Documents and Setting」辺りのデータを外部HDDに吸い出した。
その後はUbuntuを.isoファイルから焼いたCDでサクッとインストール。これでUbuntuマシンがいっちょあがりなのだから簡単なものだ。Linuxといったら恐ろしく難解で、訳の分からないコマンドを山のように覚えて、解読不能の設定ファイルの山と格闘してもなおインストールする前に挫折してしまう恐怖のOS…という思い込みが自分にはあったのだが、自分の認識はこのポンコツPC以上に古すぎたようだ。
あとH/W的にはモニタをBenQ 20.1inchLCDに交換し、そこら辺に転がっていた無線LANカードを差した位だろうか。S/Wはこれから弄るつもりである。
そして調子に乗った自分は、今回は本務機のラップトップ、VAIO TypeS(VGN-SZ53B)にも手を入れてみた。実験機にUbuntuを入れるだけでは飽き足らず、こちらにも仮想マシンとしてUbuntuを入れることにしてみたのだ。デュアルブートではなく仮想化を選んだ理由?仮想化はロマンですよ、ええ。ウィンドウの中で別のOSが走っているとか、ヲタな心性に相当アピールしますから。
さて、使った仮想マシン環境はVMware Server。VirtualBoxというソフトもあるらしいけれども、そちらを選ばなかったのは単なる気まぐれ。VMwareの方が動作が軽いという耳にした噂を信じて決めた。VMware Serverというソフトは、元は有償ソフトだったそうだが、最近無償で提供されるようになったという。ありがたい話だ。で、その軽いと噂のVMware、どんなものかとwktkしながらUbuntuの仮想マシンをマウントして立ち上げてみたものの…やっぱ重すぎ。メモリ増設前の払下げPCと大差ない体感速度。…いや、Vistaだけでももたつく1GBメモリPCで無謀なトライをした自分が悪いんですけどね。
ということで、ラップトップについても急遽4GB分のメモリを注文して全て換装。今度は殆どストレスなく動くようになった。仮想マシンの立ち上げ時こそCPUがネックになり、大分待たされるが、立ち上げてしまえば普通に使っている限りサクサク動いてくれてありがたい限り。
でも目下一つの問題に直面中。VMware内のUbuntuからネットワークに接続する際、bridge構成を選択すると上手くいかない。NATを選べば接続できるので、ひとまずは困っていないのだが、ネットワーク内の他のPC(ubuntu入れた払下げPCとか)から見えないというのは後々困りそうなので、なんとかしたいところだ。