cd: initial commit

5 files changed, 691 insertions, 0 deletions

diff --git a/cd.nix b/cd.nix
new file mode 100644
index 00000000..47bd4c86
--- /dev/null
+++ b/cd.nix
@@ -0,0 +1,102 @@
+{ config, pkgs, ... }:
+
+{
+  imports =
+    [
+      <secrets/hashedPasswords.nix>
+      ./modules/base-cac-CentOS-7-64bit.nix
+      ./modules/exim-cd.nix
+      #./modules/ejabberd-cd.nix # XXX echtes modul
+      ./modules/iptables-cd.nix
+      ./modules/networking-cd.nix
+      ./modules/retiolum.nix
+    ];
+
+  # "Developer 2" plan has two vCPUs.
+  nix.maxJobs = 2;
+
+
+  environment.systemPackages = with pkgs; [
+    htop
+    iftop
+    iotop
+    nethogs
+    rxvt_unicode.terminfo
+    tcpdump
+  ];
+
+  security.rtkit.enable = false;
+
+  services.cron.enable = false;
+
+  #services.ejabberd-cd = {
+  #  enable = true;
+  #  #virtualHosts = ''"jabber.viljetic.de", "viljetic.de"'';
+  #};
+
+  services.journald.extraConfig = ''
+    SystemMaxUse=1G
+    RuntimeMaxUse=128M
+  '';
+
+  services.ntp.enable = false;
+
+  services.openssh = {
+    enable = true;
+    hostKeys = [
+      # XXX bits here make no science
+      { bits = 8192; type = "ed25519"; path = "/etc/ssh/ssh_host_ed25519_key"; }
+    ];
+    permitRootLogin = "yes";
+  };
+
+  services.retiolum = {
+    enable = true;
+    hosts = ./hosts;
+    privateKeyFile = "/etc/nixos/secrets/cd.retiolum.rsa_key.priv";
+    connectTo = [
+      "fastpoke"
+      "pigstarter"
+      "ire"
+    ];
+  };
+
+  sound.enable = false;
+
+  # TODO base
+  time.timeZone = "UTC";
+
+  # TODO replace by ./modules/cd-users.nix
+  users.extraGroups = {
+
+    # ● systemd-tmpfiles-setup.service - Create Volatile Files and Directories
+    #    Loaded: loaded (/nix/store/2l33gg7nmncqkpysq9f5fxyhlw6ncm2j-systemd-217/example/systemd/system/systemd-tmpfiles-setup.service)
+    #    Active: failed (Result: exit-code) since Mon 2015-03-16 10:29:18 UTC; 4s ago
+    #      Docs: man:tmpfiles.d(5)
+    #            man:systemd-tmpfiles(8)
+    #   Process: 19272 ExecStart=/nix/store/2l33gg7nmncqkpysq9f5fxyhlw6ncm2j-systemd-217/bin/systemd-tmpfiles --create --remove --boot --exclude-prefix=/dev (code=exited, status=1/FAILURE)
+    #  Main PID: 19272 (code=exited, status=1/FAILURE)
+    # 
+    # Mar 16 10:29:17 cd systemd-tmpfiles[19272]: [/usr/lib/tmpfiles.d/legacy.conf:26] Unknown group 'lock'.
+    # Mar 16 10:29:18 cd systemd-tmpfiles[19272]: Two or more conflicting lines for /var/log/journal configured, ignoring.
+    # Mar 16 10:29:18 cd systemd-tmpfiles[19272]: Two or more conflicting lines for /var/log/journal/7b35116927d74ea58785e00b47ac0f0d configured, ignoring.
+    # Mar 16 10:29:18 cd systemd[1]: systemd-tmpfiles-setup.service: main process exited, code=exited, status=1/FAILURE
+    # Mar 16 10:29:18 cd systemd[1]: Failed to start Create Volatile Files and Directories.
+    # Mar 16 10:29:18 cd systemd[1]: Unit systemd-tmpfiles-setup.service entered failed state.
+    # Mar 16 10:29:18 cd systemd[1]: systemd-tmpfiles-setup.service failed.
+    # warning: error(s) occured while switching to the new configuration
+    lock.gid = 10001;
+
+  };
+  users.extraUsers =
+    {
+      root = {
+        openssh.authorizedKeys.keys = [
+          "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIEieAihh+o208aeCA14fAtjzyZN/nrpOJt2vZ5VYZp69 deploy@wu"
+          "ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQDDYv5OkVrnerkzJwgi7ol7HzcWJf4oWCJTX84trFX5vgJXu1zMvSe+koY8xpnMOd7WHF2wgsjjrFlMuixTrfMPc/OjvG2N1TlnvzlFD8ivTW/AJzDwNxT//niqAYAZ9kmb8e/zE/SyNHSKZcyEKGiiW2+YW9wWHPYRP/XiNEjLP3BeTGScMwWr001V/8m7ne4SGHrE1FbHbHqaBXgqUFgnvzMY3CsfDafODZlj5xSMNGHyLGNNKvu3YR1crcAjbQrBXBdwaArThFxp+e2uWrnffshlks6WtRyR1AFVjc/gxEG74Axq1AHY6EJm2Fw/JdFNiYQ7yyQZHS9bZJYjgnWF tv@nomic"
+        ];
+      };
+    };
+  users.mutableUsers = false;
+
+}
diff --git a/modules/base-cac-CentOS-7-64bit.nix b/modules/base-cac-CentOS-7-64bit.nix
new file mode 100644
index 00000000..42ab481b
--- /dev/null
+++ b/modules/base-cac-CentOS-7-64bit.nix
@@ -0,0 +1,27 @@
+{ config, pkgs, ... }:
+
+{
+  boot.loader.grub.device = "/dev/sda";
+  boot.loader.grub.enable = true;
+  boot.loader.grub.version = 2;
+
+  boot.initrd.availableKernelModules = [
+    "ata_piix"
+    "vmw_pvscsi"
+  ];
+
+  fileSystems."/" = {
+    device = "/dev/centos/root";
+    fsType = "xfs";
+  };
+
+  fileSystems."/boot" = {
+    device = "/dev/sda1";
+    fsType = "xfs";
+  };
+
+  swapDevices = [
+    { device = "/dev/centos/swap"; }
+  ];
+}
+
diff --git a/modules/exim-cd.nix b/modules/exim-cd.nix
new file mode 100644
index 00000000..b28f3943
--- /dev/null
+++ b/modules/exim-cd.nix
@@ -0,0 +1,473 @@
+{ config, pkgs, ... }:
+
+let
+  inherit (builtins) toFile;
+  inherit (pkgs.lib.attrsets) mapAttrs;
+  inherit (pkgs.lib.strings) concatMapStringsSep;
+in
+
+{
+  services.exim =
+    let
+      retiolumHostname = "${config.networking.hostName}.retiolum";
+
+      internet-aliases = [
+        { from = "tomislav@viljetic.de"; to = "tv@wu.retiolum"; }
+
+        # (mindestens) lisp-stammtisch und elli haben die:
+        { from = "tv@viljetic.de"; to = "tv@wu.retiolum"; }
+
+        { from = "tv@destroy.dyn.shackspace.de"; to = "tv@wu.retiolum"; }
+
+        { from = "mirko@viljetic.de"; to = "mv@cd.retiolum"; }
+
+        # TODO killme (wo wird die benutzt?)
+        { from = "tv@cd.retiolum"; to = "tv@wu.retiolum"; }
+
+        { from = "postmaster@krebsco.de"; to = "tv@wu.retiolum"; }
+      ];
+
+      system-aliases = [
+        { from = "mailer-daemon"; to = "postmaster"; }
+        { from = "postmaster"; to = "root"; }
+        { from = "nobody"; to = "root"; }
+        { from = "hostmaster"; to = "root"; }
+        { from = "usenet"; to = "root"; }
+        { from = "news"; to = "root"; }
+        { from = "webmaster"; to = "root"; }
+        { from = "www"; to = "root"; }
+        { from = "ftp"; to = "root"; }
+        { from = "abuse"; to = "root"; }
+        { from = "noc"; to = "root"; }
+        { from = "security"; to = "root"; }
+        { from = "root"; to = "tv"; }
+      ];
+
+      to-lsearch = concatMapStringsSep "\n" ({ from, to }: "${from}: ${to}");
+      lsearch =
+        mapAttrs (name: set: toFile name (to-lsearch set)) {
+          inherit internet-aliases;
+          inherit system-aliases;
+        };
+    in
+    {
+      enable = true;
+      config =
+        ''
+          primary_hostname = ${retiolumHostname}
+
+          # HOST_REDIR contains the real destinations for "local_domains".
+          #HOST_REDIR = /etc/exim4/host_redirect
+
+
+          # Domains not listed in local_domains need to be deliverable remotely.
+          # XXX We abuse local_domains to mean "domains, we're the gateway for".
+          domainlist local_domains    = @ : localhost
+          #: viljetic.de : SHACK_REDIR_HOSTNAME
+          domainlist relay_to_domains =
+          hostlist   relay_from_hosts = <; 127.0.0.1 ; ::1 ; 10.243.13.37
+
+          acl_smtp_rcpt = acl_check_rcpt
+          acl_smtp_data = acl_check_data
+
+          # av_scanner = clamd:/tmp/clamd
+          # spamd_address = 127.0.0.1 783
+
+          # tls_advertise_hosts = *
+          # tls_certificate = /etc/ssl/exim.crt
+          # tls_privatekey = /etc/ssl/exim.pem
+          # (debian) tls_verify_certificates (to check client certs)
+
+          # daemon_smtp_ports = 25 : 465 : 587
+          # tls_on_connect_ports = 465
+
+          # qualify_domain defaults to primary_hostname
+          # qualify_recipient defaults to qualify_domain
+
+          # allow_domain_literals
+
+          never_users = root
+
+          host_lookup = *
+
+          # ident callbacks for all incoming SMTP calls
+          rfc1413_hosts = *
+          rfc1413_query_timeout = 5s
+
+          # sender_unqualified_hosts =
+          # recipient_unqualified_hosts =
+
+          # percent_hack_domains =
+
+          # arch & debian
+          #ignore_bounce_errors_after = 2d
+          #timeout_frozen_after = 7d
+          # debian
+          #smtp_banner = $smtp_active_hostname ESMTP Exim $version_number $tod_full
+          #freeze_tell = postmaster
+          #trusted_users = uucp
+          # arch
+          #split_spool_directory = true
+
+          log_selector = -queue_run +address_rewrite +all_parents +queue_time
+          log_file_path = syslog
+          syslog_timestamp = false
+          syslog_duplication = false
+
+          begin acl
+
+          acl_check_rcpt:
+            # Accept if the source is local SMTP (i.e. not over TCP/IP).
+            # We do this by testing for an empty sending host field.
+            accept  hosts = :
+                    # arch & debian:
+                    control = dkim_disable_verify
+
+            deny    message       = Restricted characters in address
+                    domains       = +local_domains
+                    local_parts   = ^[.] : ^.*[@%!/|]
+
+            deny    message       = Restricted characters in address
+                    domains       = !+local_domains
+                    local_parts   = ^[./|] : ^.*[@%!] : ^.*/\\.\\./
+
+            accept  local_parts   = postmaster
+                    domains       = +local_domains
+
+            ## feature RETIOLUM_MAIL
+            #accept
+            #  hosts = *.retiolum
+            #  domains = *.retiolum
+            #  control = dkim_disable_verify
+
+            #require verify        = sender
+
+            accept  hosts         = +relay_from_hosts
+                    control       = submission
+                    # debian: control = submission/sender_retain
+                    # arch & debian:
+                    control       = dkim_disable_verify
+
+            accept  authenticated = *
+                    control       = submission
+                    control       = dkim_disable_verify
+
+            accept message = relay not permitted 2
+                    recipients = lsearch;${lsearch.internet-aliases}
+
+            require message = relay not permitted
+                    domains = +local_domains : +relay_to_domains
+
+            require
+              message = unknown user
+              verify = recipient/callout
+
+            # deny    message       = rejected because $sender_host_address is in a black list at $dnslist_domain\n$dnslist_text
+            #         dnslists      = black.list.example
+            #
+            # warn    dnslists      = black.list.example
+            #         add_header    = X-Warning: $sender_host_address is in a black list at $dnslist_domain
+            #         log_message   = found in $dnslist_domain
+
+            # Client SMTP Authorization (csa) checks on the sending host.
+            # Such checks do DNS lookups for special SRV records.
+            # require verify = csa
+
+            accept
+
+
+          acl_check_data:
+            # see av_scanner
+            #deny    malware    = *
+            #        message    = This message contains a virus ($malware_name).
+
+            # Add headers to a message if it is judged to be spam. Before enabling this,
+            # you must install SpamAssassin. You may also need to set the spamd_address
+            # option above.
+            #
+            # warn    spam       = nobody
+            #         add_header = X-Spam_score: $spam_score\n\
+            #                      X-Spam_score_int: $spam_score_int\n\
+            #                      X-Spam_bar: $spam_bar\n\
+            #                      X-Spam_report: $spam_report
+
+            # feature HELO_REWRITE
+            # XXX note that the public ip (162.219.5.183) resolves to viljetic.de
+            warn
+              sender_domains = viljetic.de : shackspace.de
+              set acl_m_special_dom = $sender_address_domain
+
+            accept
+
+
+          begin routers
+
+          # feature RETIOLUM_MAIL
+          retiolum:
+            debug_print = "R: retiolum for $local_part@$domain"
+            driver = manualroute
+            domains = ! ${retiolumHostname} : *.retiolum
+            transport = retiolum_smtp
+            route_list = ^.* $0 byname
+            no_more
+
+          internet_aliases:
+            debug_print = "R: internet_aliases for $local_part@$domain"
+            driver = redirect
+            data = ''${lookup{$local_part@$domain}lsearch{${lsearch.internet-aliases}}}
+
+          dnslookup:
+            debug_print = "R: dnslookup for $local_part@$domain"
+            driver = dnslookup
+            domains = ! +local_domains
+            transport = remote_smtp
+            ignore_target_hosts = 0.0.0.0 : 127.0.0.0/8
+            # if ipv6-enabled then instead use:
+            # ignore_target_hosts = <; 0.0.0.0 ; 127.0.0.0/8 ; ::1
+
+            # (debian) same_domain_copy_routing = yes
+            # (debian) ignore private rfc1918 and APIPA addresses
+            # (debian) ignore_target_hosts = 0.0.0.0 : 127.0.0.0/8 : 192.168.0.0/16 :\
+            #                   172.16.0.0/12 : 10.0.0.0/8 : 169.254.0.0/16 :\
+            #                   255.255.255.255
+
+            # Fail and bounce if the router does not find the domain in the DNS.
+            # I.e. no more routers are tried.
+            # There are a few cases where a dnslookup router will decline to accept an
+            # address; if such a router is expected to handle "all remaining non-local
+            # domains", then it is important to set no_more.
+            no_more
+
+          # XXX this is only used because these "well known aliases" goto tv@cd.retiolum
+          # TODO bounce everything, there is no @cd.retiolum
+          system_aliases:
+            debug_print = "R: system_aliases for $local_part@$domain"
+            driver = redirect
+            data = ''${lookup{$local_part}lsearch{${lsearch.system-aliases}}}
+
+          # TODO this is only b/c mv here... send mv's mails somewhere else...
+          local_user:
+            debug_print = "R: local_user for $local_part@$domain"
+            driver = accept
+            check_local_user
+          # local_part_suffix = +* : -*
+          # local_part_suffix_optional
+            transport = home_maildir
+            cannot_route_message = Unknown user
+
+          begin transports
+
+          retiolum_smtp:
+            driver = smtp
+            retry_include_ip_address = false
+            # serialize_hosts = TODO-all-slow-hosts
+
+          remote_smtp:
+            driver = smtp
+            # debian has also stuff for tls, headers_rewrite and more here
+
+            # feature HELO_REWRITE
+            # XXX note that the public ip (162.219.5.183) resolves to viljetic.de
+            helo_data = ''${if eq{$acl_m_special_dom}{}  \
+                                 {$primary_hostname}   \
+                                 {$acl_m_special_dom} }
+
+          home_maildir:
+            driver = appendfile
+            maildir_format
+            maildir_use_size_file
+            directory = $home/Maildir
+            directory_mode = 0700
+            delivery_date_add
+            envelope_to_add
+            return_path_add
+
+          begin retry
+          *.retiolum             *           F,42d,1m
+          *                      *           F,2h,15m; G,16h,1h,1.5; F,4d,6h
+
+          begin rewrite
+          begin authenticators
+        '';
+
+
+          # group = mail
+          # mode = 0660
+
+
+          #address_pipe:
+          #  driver = pipe
+          #  return_output
+          #
+          #address_file:
+          #  driver = appendfile
+          #  delivery_date_add
+          #  envelope_to_add
+          #  return_path_add
+          #
+          #address_reply:
+          #  driver = autoreply
+
+
+          #maildrop_pipe:
+          #  debug_print = "T: maildrop_pipe for $local_part@$domain"
+          #  driver = pipe
+          #  path = "/bin:/usr/bin:/usr/local/bin"
+          #  command = "/usr/bin/maildrop"
+          #  return_path_add
+          #  delivery_date_add
+          #  envelope_to_add
+
+
+
+
+
+          ##begin retry
+          # Address or Domain    Error       Retries
+
+          # Our host_redirect destinations might be offline a lot.
+          # TODO define fallback destinations(?)
+          #lsearch;${lsearch.internet-aliases} * F,42d,1m
+
+
+          ## begin rewrite
+
+          # just in case (shackspace.de should already do this)
+          #tv@shackspace.de  tv@SHACK_REDIR_HOSTNAME  T
+
+
+          ## begin authenticators
+          #PLAIN:
+          #  driver                  = plaintext
+          #  server_set_id           = $auth2
+          #  server_prompts          = :
+          #  server_condition        = Authentication is not yet configured
+          #  server_advertise_condition = ''${if def:tls_in_cipher }
+
+          #LOGIN:
+          #  driver                  = plaintext
+          #  server_set_id           = $auth1
+          #  server_prompts          = <| Username: | Password:
+          #  server_condition        = Authentication is not yet configured
+          #  server_advertise_condition = ''${if def:tls_in_cipher }
+
+
+
+      };
+
+}
+
+#        config = ''
+#          primary_hostname = ${retiolumHostname}
+#          domainlist local_domains    = @ : localhost
+#          domainlist relay_to_domains = *.retiolum
+#          hostlist   relay_from_hosts = <; 127.0.0.1 ; ::1
+#
+#          acl_smtp_rcpt = acl_check_rcpt
+#          acl_smtp_data = acl_check_data
+#
+#          host_lookup = *
+#          rfc1413_hosts = *
+#          rfc1413_query_timeout = 5s
+#
+#          log_file_path = syslog
+#          syslog_timestamp = false
+#          syslog_duplication = false
+#
+#          begin acl
+#
+#          acl_check_rcpt:
+#            accept  hosts = :
+#                    control = dkim_disable_verify
+#
+#            deny    message       = Restricted characters in address
+#                    domains       = +local_domains
+#                    local_parts   = ^[.] : ^.*[@%!/|]
+#
+#            deny    message       = Restricted characters in address
+#                    domains       = !+local_domains
+#                    local_parts   = ^[./|] : ^.*[@%!] : ^.*/\\.\\./
+#
+#            accept  local_parts   = postmaster
+#                    domains       = +local_domains
+#
+#            #accept
+#            #  hosts = *.retiolum
+#            #  domains = *.retiolum
+#            #  control = dkim_disable_verify
+#
+#            #require verify        = sender
+#
+#            accept  hosts         = +relay_from_hosts
+#                    control       = submission
+#                    control       = dkim_disable_verify
+#
+#            accept  authenticated = *
+#                    control       = submission
+#                    control       = dkim_disable_verify
+#
+#            require message = relay not permitted
+#                    domains = +local_domains : +relay_to_domains
+#
+#            require verify = recipient
+#
+#            accept
+#
+#
+#          acl_check_data:
+#            accept
+#
+#
+#          begin routers
+#
+#          retiolum:
+#            driver = manualroute
+#            domains = ! ${retiolumHostname} : *.retiolum
+#            transport = remote_smtp
+#            route_list = ^.* $0 byname
+#            no_more
+#
+#          nonlocal:
+#            debug_print = "R: nonlocal for $local_part@$domain"
+#            driver = redirect
+#            domains = ! +local_domains
+#            allow_fail
+#            data = :fail: Mailing to remote domains not supported
+#            no_more
+#
+#          local_user:
+#            # debug_print = "R: local_user for $local_part@$domain"
+#            driver = accept
+#            check_local_user
+#          # local_part_suffix = +* : -*
+#          # local_part_suffix_optional
+#            transport = home_maildir
+#            cannot_route_message = Unknown user
+#
+#
+#          begin transports
+#
+#          remote_smtp:
+#            driver = smtp
+#
+#          home_maildir:
+#            driver = appendfile
+#            maildir_format
+#            directory = $home/Maildir
+#            directory_mode = 0700
+#            delivery_date_add
+#            envelope_to_add
+#            return_path_add
+#          # group = mail
+#          # mode = 0660
+#
+#          begin retry
+#          *.retiolum             *           F,42d,1m
+#          *                      *           F,2h,15m; G,16h,1h,1.5; F,4d,6h
+#
+#          begin rewrite
+#
+#          begin authenticators
+#        '';
+#      };
+#}
diff --git a/modules/iptables-cd.nix b/modules/iptables-cd.nix
new file mode 100644
index 00000000..70736e49
--- /dev/null
+++ b/modules/iptables-cd.nix
@@ -0,0 +1,75 @@
+{ config, pkgs, ... }:
+
+{
+  #
+  # iptables
+  #
+  networking.firewall.enable = false;
+  system.activationScripts.iptables =
+    let
+      log = false;
+      when = c: f: if c then f else "";
+    in
+      ''
+        ip4tables() { ${pkgs.iptables}/sbin/iptables "$@"; }
+        ip6tables() { ${pkgs.iptables}/sbin/ip6tables "$@"; }
+        ipXtables() { ip4tables "$@" && ip6tables "$@"; }
+
+        # XXX This fails with the original CAC CentOS 7 kernel.
+        if ipXtables -vL >/dev/null; then
+
+          #
+          # nat
+          #
+
+          # reset tables
+          ipXtables -t nat -F
+          ipXtables -t nat -X
+
+          #
+          ipXtables -t nat -A PREROUTING -j REDIRECT ! -i retiolum -p tcp --dport ssh --to-ports 0
+          ipXtables -t nat -A PREROUTING -j REDIRECT -p tcp --dport 11423 --to-ports ssh
+
+          #
+          # filter
+          #
+
+          # reset tables
+          ipXtables -P INPUT DROP
+          ipXtables -P FORWARD DROP
+          ipXtables -F
+          ipXtables -X
+
+          # create custom chains
+          ipXtables -N Retiolum
+
+          # INPUT
+          ipXtables -A INPUT -j ACCEPT -m conntrack --ctstate RELATED,ESTABLISHED
+          ipXtables -A INPUT -j ACCEPT -i lo
+          ipXtables -A INPUT -j ACCEPT -p tcp --dport ssh -m conntrack --ctstate NEW
+          #ipXtables -A INPUT -j ACCEPT -p tcp --dport http -m conntrack --ctstate NEW
+          ipXtables -A INPUT -j ACCEPT -p tcp --dport tinc -m conntrack --ctstate NEW
+          ipXtables -A INPUT -j ACCEPT -p tcp --dport smtp -m conntrack --ctstate NEW
+          #ipXtables -A INPUT -j ACCEPT -p tcp --dport xmpp-client -m conntrack --ctstate NEW
+          #ipXtables -A INPUT -j ACCEPT -p tcp --dport xmpp-server -m conntrack --ctstate NEW
+
+          ipXtables -A INPUT -j Retiolum -i retiolum
+          ${when log "ipXtables -A INPUT -j LOG --log-level info --log-prefix 'INPUT DROP '"}
+
+          # FORWARD
+          ${when log "ipXtables -A FORWARD -j LOG --log-level info --log-prefix 'FORWARD DROP '"}
+
+          # Retiolum
+          ip4tables -A Retiolum -j ACCEPT -p icmp --icmp-type echo-request
+          ip6tables -A Retiolum -j ACCEPT -p ipv6-icmp -m icmp6 --icmpv6-type echo-request
+
+
+          ${when log "ipXtables -A Retiolum -j LOG --log-level info --log-prefix 'REJECT '"}
+          ipXtables -A Retiolum -j REJECT -p tcp --reject-with tcp-reset
+          ip4tables -A Retiolum -j REJECT -p udp --reject-with icmp-port-unreachable
+          ip4tables -A Retiolum -j REJECT        --reject-with icmp-proto-unreachable
+          ip6tables -A Retiolum -j REJECT -p udp --reject-with icmp6-port-unreachable
+          ip6tables -A Retiolum -j REJECT
+        fi
+      '';
+}
diff --git a/modules/networking-cd.nix b/modules/networking-cd.nix
new file mode 100644
index 00000000..215e2082
--- /dev/null
+++ b/modules/networking-cd.nix
@@ -0,0 +1,14 @@
+{...}:
+{
+  networking.hostName = "cd";
+  networking.interfaces.enp2s1.ip4 = [
+    {
+      address = "162.219.7.216";
+      prefixLength = 24;
+    }
+  ];
+  networking.defaultGateway = "162.219.7.1";
+  networking.nameservers = [
+    "8.8.8.8"
+  ];
+}