add basic JavaScript functionality

This was the point of this little project: generating a bunch of config
files. That's what main.js does.

Also, rework the layout in index.html a bit. form-horizontal is not used
that way.

2 files changed, 487 insertions, 15 deletions

diff --git a/assets/js/main.js b/assets/js/main.js
new file mode 100644
index 0000000..b042c2a
--- /dev/null
+++ b/assets/js/main.js
@@ -0,0 +1,466 @@
+var iface = 'wg0';
+var persistent_keepalive = 25;
+
+function parse_placeholder(val) {
+    return true;
+}
+
+function parse_endpoint(val) {
+    val = val.trim();
+    if (val.length == 0) {
+        throw new Error('Server endpoint cannot be an empty string.');
+    }
+    return val;
+}
+
+function parse_key(val) {
+    val = val.trim();
+    if (val.length == 0) {
+        throw new Error('Key as used by WireGuard cannot be an empty string.');
+    }
+    return val;
+}
+
+var IPAddr = function(src, parser) {
+    this.src = src;
+    this.parser = parser;
+
+    try {
+        var val = parser.parseCIDR(src);
+    } catch (err) {
+        throw new Error('Sorry, IP address validation failed with the following error:\n' + err.message);
+    }
+
+    this.addr = val[0];
+    this.netmask = val[1];
+
+    this.str = this.addr.toString();
+
+    if (this.addr.kind() == 'ipv4') {
+        var networkID = parser.networkAddressFromCIDR(this.src);
+        if (this.str == networkID) {
+            throw new Error('Please use a real host IP address, not a network identifier.');
+        }
+        var broadcast = parser.broadcastAddressFromCIDR(this.src);
+        if (this.str == broadcast) {
+            throw new Error('Please use a real host IP address, not a broadcast address.');
+        }
+    }
+}
+
+IPAddr.prototype.for_client = function() {
+    return this.str + '/' + this.netmask;
+}
+
+IPAddr.prototype.for_server = function() {
+    if (this.addr.kind() == 'ipv4') {
+        var netmask = 32;
+    } else if (this.addr.kind() == 'ipv6') {
+        var netmask = 128;
+    } else {
+        throw new Error('What? Not IPv4, and _not_ IPv6?!');
+    }
+    return this.str + '/' + netmask;
+}
+
+function parse_ip(src, parser) {
+    src = src.trim();
+    if (src.length == 0) {
+        throw new Error('IP address cannot be an empty string.');
+    }
+    return new IPAddr(src, parser);
+}
+
+function parse_ipv4(val) {
+    return parse_ip(val, ipaddr.IPv4);
+}
+
+function parse_ipv6(val) {
+    return parse_ip(val, ipaddr.IPv6);
+}
+
+var Input = function(name) {
+    this.name = name;
+}
+
+Input.prototype.input_id = function() {
+    return '#param_' + this.name;
+}
+
+Input.prototype.error_id = function() {
+    return this.input_id() + '_error';
+}
+
+Input.prototype.value = function() {
+    return $(this.input_id()).val();
+}
+
+Input.prototype.show_error = function(msg) {
+    $(this.error_id()).text(msg);
+    $(this.error_id()).show();
+}
+
+Input.prototype.hide_error = function() {
+    $(this.error_id()).hide();
+}
+
+var Value = function(name, parser) {
+    this.input = new Input(name);
+    this.parser = parser;
+
+    this.value = null;
+    this.error = null;
+    try {
+        this.value = parser(this.input.value());
+        this.input.hide_error();
+    } catch (err) {
+        this.error = err.message;
+        this.input.show_error(this.error);
+    }
+}
+
+var Endpoint = function(name) {
+    Value.call(this, name, parse_endpoint);
+}
+
+Endpoint.prototype = Object.create(Value.prototype);
+Endpoint.prototype.constructor = Endpoint;
+
+var Key = function(name) {
+    Value.call(this, name, parse_key);
+}
+
+Key.prototype = Object.create(Value.prototype);
+Key.prototype.constructor = Key;
+
+var IPv4 = function(name) {
+    Value.call(this, name, parse_ipv4);
+}
+
+IPv4.prototype = Object.create(Value.prototype);
+IPv4.prototype.constructor = IPv4;
+
+var IPv6 = function(name) {
+    Value.call(this, name, parse_ipv6);
+}
+
+IPv6.prototype = Object.create(Value.prototype);
+IPv6.prototype.constructor = IPv6;
+
+var Data = function() {
+    this.server_endpoint  = new Endpoint('server_endpoint');
+    this.server_public    = new Key('server_public_key');
+    this.server_preshared = new Key('server_preshared_key');
+    this.client_public    = new Key('client_public_key');
+    this.client_private   = new Key('client_private_key');
+    this.client_ipv4      = new IPv4('client_ipv4');
+    this.client_ipv6      = new IPv6('client_ipv6');
+
+    this.values = [
+        this.server_endpoint,
+        this.server_public,
+        this.server_preshared,
+        this.client_public,
+        this.client_private,
+        this.client_ipv4,
+        this.client_ipv6
+    ];
+
+    if (this.has_errors()) {
+        this.show_error('Please correct the input errors above first.');
+    } else {
+        this.hide_error();
+    }
+}
+
+Data.prototype.has_errors = function() {
+    var has = false;
+    this.values.forEach(function(value) {
+        if (value.error) {
+            has = true;
+        }
+    });
+    return has;
+}
+
+Data.prototype.show_error = function(msg) {
+    $('#params_error').text(msg);
+    $('#params_error').show();
+}
+
+Data.prototype.hide_error = function() {
+    $('#params_error').hide();
+}
+
+var ConfigFile = function(name, contents) {
+    this.name = name;
+    this.contents = contents;
+}
+
+ConfigFile.prototype.toString = function() {
+    return this.contents;
+}
+
+var Script = function(text) {
+    this.text = text;
+}
+
+Script.prototype.toString = function() {
+    return this.text;
+}
+
+function wg_quick_client_file(data) {
+    var path = `/etc/wireguard/${iface}.conf`;
+    return new ConfigFile(path,
+`# On the client, put this to ${path} and either start the
+# the wg-quick@${iface} systemd service, or run \`wg-quick up ${iface}\`.
+
+[Interface]
+PrivateKey = ${data.client_private.value}
+
+[Peer]
+Endpoint = ${data.server_endpoint.value}
+PublicKey = ${data.server_public.value}
+PresharedKey = ${data.server_preshared.value}
+AllowedIPs = ${data.client_ipv4.value.for_client()}, ${data.client_ipv6.value.for_client()}
+PersistentKeepalive = ${persistent_keepalive}
+`);
+}
+
+function wg_quick_server_file(data) {
+    var path = `/etc/wireguard/${iface}.conf`;
+    return new ConfigFile(path,
+`# On the server, add this to ${path} and either restart
+# the wg-quick@${iface} systemd service, or run \`wg syncconf ${iface}
+# ${path}\`.
+
+# Previous contents goes here...
+
+[Peer]
+PublicKey = ${data.client_public.value}
+PresharedKey = ${data.server_preshared.value}
+AllowedIPs = ${data.client_ipv4.value.for_server()}, ${data.client_ipv6.value.for_server()}
+`);
+}
+
+function systemd_client_netdev_file(data) {
+    var path = `/etc/systemd/network/${iface}.netdev`;
+    return new ConfigFile(path,
+`# On the client, you need two files. Put this into ${path}
+# and after you're done with both files, restart the systemd-networkd service.
+
+[NetDev]
+Name = ${iface}
+Kind = wireguard
+
+[WireGuard]
+PrivateKey = ${data.client_private.value}
+
+[WireGuardPeer]
+Endpoint = ${data.server_endpoint.value}
+PublicKey = ${data.server_public.value}
+PresharedKey = ${data.server_preshared.value}
+AllowedIPs = ${data.client_ipv4.value.for_client()}, ${data.client_ipv6.value.for_client()}
+PersistentKeepalive = ${persistent_keepalive}
+`);
+}
+
+function systemd_client_network_file(data) {
+    var path = `/etc/systemd/network/${iface}.network`;
+    return new ConfigFile(path,
+`# This is the second file. Put this into ${path}
+# and if you're done the first file already, restart the systemd-networkd
+# service.
+
+[Match]
+Name = ${iface}
+
+[Network]
+Address = ${data.client_ipv4.value.for_client()}
+Address = ${data.client_ipv6.value.for_client()}
+`);
+}
+
+function systemd_server_netdev_file(data) {
+    var path = `/etc/systemd/network/${iface}.netdev`;
+    return new ConfigFile(path,
+`# On the server, add this to ${path} and restart
+# the systemd-networkd service.
+
+# Previous contents goes here...
+
+[WireGuardPeer]
+PublicKey = ${data.client_public.value}
+PresharedKey = ${data.server_preshared.value}
+AllowedIPs = ${data.client_ipv4.value.for_server()}, ${data.client_ipv6.value.for_server()}
+`);
+}
+
+function nmcli_client_file(data) {
+    var path = `/etc/NetworkManager/system-connections/${iface}.nmconnection`;
+    return new ConfigFile(path,
+`# On the client, put this to ${path}
+# and run \`nmcli c reload && nmcli c up ${iface}\`.
+
+[connection]
+id=${iface}
+type=wireguard
+interface-name=${iface}
+
+[wireguard]
+private-key=${data.client_private.value}
+private-key-flags=0
+
+[wireguard-peer.${data.server_public.value}]
+endpoint=${data.server_endpoint.value}
+preshared-key=${data.server_preshared.value}
+preshared-key-flags=0
+allowed-ips=${data.client_ipv4.value.for_client()};${data.client_ipv6.value.for_client()};
+persistent-keepalive=${persistent_keepalive}
+
+[ipv4]
+address1=${data.client_ipv4.value.for_client()}
+method=manual
+
+[ipv6]
+address1=${data.client_ipv6.value.for_client()}
+method=manual
+`);
+}
+
+function nmcli_server_file(data) {
+    var path = `/etc/NetworkManager/system-connections/${iface}.nmconnection`;
+    return new ConfigFile(path,
+`# On the server, add this to ${path}
+# and run \`nmcli c reload && nmcli c up ${iface}\';
+
+# Previous contents goes here...
+
+[wireguard-peer.${data.client_public.value}]
+preshared-key=${data.server_preshared.value}
+preshared-key-flags=0
+allowed-ips=${data.client_ipv4.value.for_server()};${data.client_ipv6.value.for_server()};
+`);
+}
+
+function manual_client_script(data) {
+    return new Script(
+`# On the client, run this to set up a connection.
+# Make sure your .bash_history or whatever is secure before running this.
+
+ip link add dev ${iface} type wireguard
+ip addr add ${data.client_ipv4.value.for_client()} dev ${iface}
+ip addr add ${data.client_ipv6.value.for_client()} dev ${iface}
+wg set ${iface} private-key <( echo ${data.client_private.value} )
+wg set ${iface} peer ${data.server_public.value} preshared-key <( echo ${data.server_preshared.value} ) endpoint ${data.server_endpoint.value} allowed-ips ${data.client_ipv4.value.for_client()},${data.client_ipv6.value.for_client()}
+ip link set ${iface} up
+`);
+}
+
+function manual_server_script(data) {
+    return new Script(
+`# On the server, run this to tweak an existing connection.
+# Make sure your .bash_history or whatever is secure before running this.
+
+wg set ${iface} peer ${data.client_public.value} preshared-key <( echo ${data.server_preshared.value} ) allowed-ips ${data.client_ipv4.value.for_server()},${data.client_ipv6.value.for_server()}
+`);
+}
+
+var InstructWgQuick = function() {}
+
+InstructWgQuick.prototype.name = function() { return 'wg-quick'; }
+
+InstructWgQuick.prototype.for_client = function(data) {
+    return [wg_quick_client_file(data)];
+}
+
+InstructWgQuick.prototype.for_server = function(data) {
+    return [wg_quick_server_file(data)];
+}
+
+var InstructSystemd = function() {}
+
+InstructSystemd.prototype.name = function() { return 'systemd-networkd'; }
+
+InstructSystemd.prototype.for_client = function(data) {
+    return [systemd_client_netdev_file(data), systemd_client_network_file(data)];
+}
+InstructSystemd.prototype.for_server = function(data) {
+    return [systemd_server_netdev_file(data)];
+}
+
+var InstructNetworkManager = function() {}
+
+InstructNetworkManager.prototype.name = function() { return 'NetworkManager'; }
+
+InstructNetworkManager.prototype.for_client = function(data) {
+    return [nmcli_client_file(data)];
+}
+
+InstructNetworkManager.prototype.for_server = function(data) {
+    return [nmcli_server_file(data)];
+}
+
+var InstructManual = function() {}
+
+InstructManual.prototype.name = function() { return 'Manual'; }
+
+InstructManual.prototype.for_client = function(data) {
+    return [manual_client_script(data)];
+}
+
+InstructManual.prototype.for_server = function(data) {
+    return [manual_server_script(data)];
+}
+
+function clear_instructors() {
+    $('#instructors').empty();
+}
+
+function format_instructions(instructions) {
+    var container = $('<div/>');
+    instructions.forEach(function(instruction) {
+        container.append($('<pre/>').text(instruction.toString()));
+    });
+    return container;
+}
+
+function format_server_instructions(instructor, data) {
+    return format_instructions(instructor.for_server(data));
+}
+
+function format_client_instructions(instructor, data) {
+    return format_instructions(instructor.for_client(data));
+}
+
+function add_instructor(instructor, data) {
+    $('#instructors').append($('<div/>')
+        .append($('<h2/>').text(instructor.name()))
+        .append($('<div class="row"/>')
+            .append($('<div class="col-md-6"/>')
+                .append(format_server_instructions(instructor, data)))
+            .append($('<div class="col-md-6"/>')
+                .append(format_client_instructions(instructor, data)))));
+}
+
+function form_on_submit() {
+    clear_instructors();
+
+    var data = new Data();
+    if (data.has_errors()) {
+        return false;
+    }
+
+    var instructors = [
+        new InstructWgQuick(),
+        new InstructSystemd(),
+        new InstructNetworkManager(),
+        new InstructManual()
+    ];
+
+    instructors.forEach(function(instructor) {
+        add_instructor(instructor, data);
+    });
+
+    return false;
+}
diff --git a/index.html b/index.html
index 832fb1b..66d8e60 100644
--- a/index.html
+++ b/index.html
@@ -4,6 +4,9 @@ layout: plain
 navbar:
   link: Main
   icon: home
+custom_js:
+  - https://cdn.jsdelivr.net/npm/ipaddr.js@2.0.0/ipaddr.min.js
+  - main.js
 
 params:
   - id: server
@@ -68,38 +71,41 @@ show the configuration that can be easily consumed by the new client.</p>
   </div>
 </div>
 
-<form class="form-horizontal">
+<form action="javascript:void(0);" onsubmit="form_on_submit(); return false;">
   <div class="row">
 {% for grp in page.params %}
     <div class="col-md-6">
-      <div class="form-group">
-        <div class="row">
+      <div class="form-horizontal">
+        <div class="form-group">
           <div class="col-sm-offset-3 col-sm-9">
             <h2 class="text-center h3" style="margin-bottom: 0;">{{ grp.desc }}</h2>
           </div>
         </div>
-      </div>
   {% for param in grp.items %}
-      <div class="form-group">
-        <div class="row">
+        <div class="form-group">
           <label for="param_{{ grp.id }}_{{ param.id }}" class="col-sm-3 control-label">{{ param.name }}</label>
           <div class="col-sm-9">
             <input type="text" class="form-control" id="param_{{ grp.id }}_{{ param.id }}" placeholder="{{ param.placeholder }}" aria-describedby="param_{{ grp.id }}_{{ param.id }}_help">
-            <span id="param_{{ grp.id }}_{{ param.id }}_help" class="help-block" style="margin-bottom: 0;">{{ param.help }}</span>
+            <span id="param_{{ grp.id }}_{{ param.id }}_help" class="help-block" style="margin-bottom: 0;">
+              <span id="param_{{ grp.id }}_{{ param.id }}_error" class="text-danger small" style="display: block; white-space: pre-line;"></span>
+              <span>{{ param.help }}</span>
+            </span>
           </div>
         </div>
-      </div>
   {% endfor %}
+      </div>
     </div>
 {% endfor %}
-    <div class="col-md-offset-6 col-md-6">
-      <div class="form-group">
-        <div class="row">
-          <div class="col-sm-offset-3 col-sm-9 text-center">
-            <button type="submit" class="btn btn-primary">Generate</button>
-          </div>
-        </div>
+    <div class="row">
+      <div class="col-md-offset-6 col-md-6 text-center">
+        <button type="submit" class="btn btn-primary">Generate</button>
+        <span class="help-block" style="margin-bottom: 0;">
+          <span id="params_error" class="text-danger small" style="white-space: pre-line;"></span>
+        </span>
       </div>
     </div>
   </div>
 </form>
+
+<div id="instructors">
+</div>