From 23351e725d31dfab8fab8634da1ef04d5c296bbd Mon Sep 17 00:00:00 2001
From: niten <niten@fudo.org>
Date: Sun, 21 Nov 2021 14:20:06 -0800
Subject: [PATCH] Initial checkin

---
 flake.nix          |  7 +++++
 lib/dns.nix        | 70 +++++++++++++++++++++++++++++++++++++++++
 lib/filesystem.nix | 32 +++++++++++++++++++
 lib/ip.nix         | 78 ++++++++++++++++++++++++++++++++++++++++++++++
 lib/lisp.nix       |  8 +++++
 lib/network.nix    | 53 +++++++++++++++++++++++++++++++
 lib/passwd.nix     | 54 ++++++++++++++++++++++++++++++++
 overlay.nix        | 14 +++++++++
 8 files changed, 316 insertions(+)
 create mode 100644 flake.nix
 create mode 100644 lib/dns.nix
 create mode 100644 lib/filesystem.nix
 create mode 100644 lib/ip.nix
 create mode 100644 lib/lisp.nix
 create mode 100644 lib/network.nix
 create mode 100644 lib/passwd.nix
 create mode 100644 overlay.nix

diff --git a/flake.nix b/flake.nix
new file mode 100644
index 0000000..7b70842
--- /dev/null
+++ b/flake.nix
@@ -0,0 +1,7 @@
+{
+  description = "Fudo Nix Helper Functions";
+
+  outputs = { self, nixpkgs, ... }: {
+    overlay = import ./overlay.nix;
+  };
+}
diff --git a/lib/dns.nix b/lib/dns.nix
new file mode 100644
index 0000000..c0979f4
--- /dev/null
+++ b/lib/dns.nix
@@ -0,0 +1,70 @@
+{ pkgs, ... }:
+
+with pkgs.lib;
+let
+  join-lines = concatStringsSep "\n";
+
+  dump = obj: builtins.trace obj obj;
+
+  makeSrvRecords = protocol: service: records: let
+    service-blah = (dump service);
+    record-blah = (dump records);
+    in
+    join-lines (map (record:
+      "_${service}._${protocol} IN SRV ${toString record.priority} ${
+        toString record.weight
+      } ${toString record.port} ${record.host}.") records);
+
+  makeSrvProtocolRecords = protocol: services:
+    join-lines (mapAttrsToList (makeSrvRecords protocol) services);
+
+  srvRecordOpts = with types; {
+    options = {
+      weight = mkOption {
+        type = int;
+        description = "Weight relative to other records.";
+        default = 1;
+      };
+
+      priority = mkOption {
+        type = int;
+        description = "Priority to give this record.";
+        default = 0;
+      };
+
+      port = mkOption {
+        type = port;
+        description = "Port to use when connecting.";
+      };
+
+      host = mkOption {
+        type = str;
+        description = "Host to contact for this service.";
+        example = "my-host.my-domain.com.";
+      };
+    };
+  };
+
+  srvRecordPair = domain: protocol: service: record: {
+    "_${service}._${protocol}.${domain}" =
+      "${toString record.priority} ${toString record.weight} ${
+        toString record.port
+      } ${record.host}.";
+  };
+
+in rec {
+
+  srvRecords = with types; attrsOf (attrsOf (listOf (submodule srvRecordOpts)));
+
+  srvRecordsToBindZone = srvRecords:
+    join-lines (mapAttrsToList makeSrvProtocolRecords srvRecords);
+
+  concatMapAttrs = f: attrs:
+    concatMap (x: x) (mapAttrsToList (key: val: f key val) attrs);
+
+  srvRecordsToPairs = domain: srvRecords: 
+    listToAttrs (concatMapAttrs (protocol: services:
+      concatMapAttrs
+      (service: records: map (srvRecordPair domain protocol service) records) services)
+      srvRecords);
+}
diff --git a/lib/filesystem.nix b/lib/filesystem.nix
new file mode 100644
index 0000000..b330564
--- /dev/null
+++ b/lib/filesystem.nix
@@ -0,0 +1,32 @@
+{ pkgs, ... }:
+
+with pkgs.lib;
+let
+  head-or-null = lst: if (lst == []) then null else head lst;
+  is-regular-file = filename: type: type == "regular" || type == "link";
+  regular-files = path: filterAttrs is-regular-file (builtins.readDir path);
+  matches-ext = ext: filename: type: (builtins.match ".+[.]${ext}$" filename) != null;
+  is-nix-file = matches-ext "nix";
+  strip-ext = ext: filename: head-or-null (builtins.match "(.+)[.]${ext}$" filename);
+  get-ext = filename: head-or-null (builtins.match "^.+[.](.+)$" filename);
+  hostname-from-file = filename: strip-ext "nix";
+  nix-files = path:
+    attrNames
+      (filterAttrs is-nix-file
+        (filterAttrs is-regular-file
+          (builtins.readDir path)));
+
+  basename-to-file-map = path: let
+    files = nix-files path;
+  in listToAttrs
+    (map (file:
+      nameValuePair (strip-ext "nix" file)
+        (path + "/${file}"))
+      files);
+
+  import-by-basename = path:
+    mapAttrs (attr: attr-file: import attr-file)
+      (basename-to-file path);
+in {
+  inherit basename-to-file-map import-by-basename;
+}
diff --git a/lib/ip.nix b/lib/ip.nix
new file mode 100644
index 0000000..33d477a
--- /dev/null
+++ b/lib/ip.nix
@@ -0,0 +1,78 @@
+{ pkgs, ... }:
+
+with pkgs.lib;
+let
+  pow = x: e: if (e == 0) then 1 else x * (pow x (e - 1));
+
+  generateNBits = n:
+    let
+      helper = n: c:
+        if (c == n) then pow 2 c else (pow 2 c) + (helper n (c + 1));
+    in if (n <= 0) then
+      throw "Can't generate 0 or fewer bits"
+    else
+      helper (n - 1) 0;
+
+  rightPadBits = int: bits: bitOr int (generateNBits bits);
+
+  reverseIpv4 = ip: concatStringsSep "." (reverseList (splitString "." ip));
+
+  intToBinaryList = int:
+    let
+      helper = int: cur:
+        let curExp = pow 2 cur;
+        in if (curExp > int) then
+          [ ]
+        else
+          [ (if ((bitAnd curExp int) > 0) then 1 else 0) ]
+          ++ (helper int (cur + 1));
+    in reverseList (helper int 0);
+
+  leftShift = int: n: int * (pow 2 n);
+
+  rightShift = int: n: int / (pow 2 n);
+
+in rec {
+
+  ipv4ToInt = ip:
+    let els = map toInt (reverseList (splitString "." ip));
+    in foldr (a: b: a + b) 0 (imap0 (i: el: (leftShift el (i * 8))) els);
+
+  intToIpv4 = int:
+    concatStringsSep "."
+    (map (i: toString (bitAnd (rightShift int (i * 8)) 255)) [ 3 2 1 0 ]);
+
+  maskFromV32Network = network:
+    let
+      fullMask = ipv4ToInt "255.255.255.255";
+      insignificantBits = 32 - (getNetworkMask network);
+    in intToIpv4
+    (leftShift (rightShift fullMask insignificantBits) insignificantBits);
+
+  networkMinIp = network: intToIpv4 (1 + (ipv4ToInt (getNetworkBase network)));
+
+  networkMaxIp = network:
+    intToIpv4 (rightPadBits (ipv4ToInt (getNetworkBase network))
+      (32 - (getNetworkMask network)));
+
+  # To avoid broadcast IP...
+  networkMaxButOneIp = network:
+    intToIpv4 ((rightPadBits (ipv4ToInt (getNetworkBase network))
+      (32 - (getNetworkMask network))) - 1);
+
+  ipv4OnNetwork = ip: network:
+    let
+      ip-int = ipv4ToInt ip;
+      net-min = networkMinIp network;
+      net-max = networkMaxIp network;
+    in (ip-int >= networkMinIp) && (ip-int <= networkMaxIp);
+
+  getNetworkMask = network: toInt (elemAt (splitString "/" network) 1);
+
+  getNetworkBase = network:
+    let
+      ip = elemAt (splitString "/" network) 0;
+      insignificantBits = 32 - (getNetworkMask network);
+    in intToIpv4
+    (leftShift (rightShift (ipv4ToInt ip) insignificantBits) insignificantBits);
+}
diff --git a/lib/lisp.nix b/lib/lisp.nix
new file mode 100644
index 0000000..1eea537
--- /dev/null
+++ b/lib/lisp.nix
@@ -0,0 +1,8 @@
+{ pkgs, ... }:
+
+with pkgs.lib;
+rec {
+  gather-dependencies = pkg: unique (pkg.propagatedBuildInputs ++ (concatMap gather-dependencies pkg.propagatedBuildInputs));
+  
+  lisp-source-registry = pkg: concatStringsSep ":" (map (p: "${p}//") (gather-dependencies pkg));
+}
diff --git a/lib/network.nix b/lib/network.nix
new file mode 100644
index 0000000..944b722
--- /dev/null
+++ b/lib/network.nix
@@ -0,0 +1,53 @@
+{ pkgs, ... }:
+
+with pkgs.lib;
+let
+  generate-mac-address = hostname: interface: pkgs.stdenv.mkDerivation {
+    name = "mk-mac-${hostname}-${interface}";
+    phases = [ "installPhase" ];
+    installPhase = ''
+      echo ${hostname}-${interface} | sha1sum | sed 's/^\(..\)\(..\)\(..\)\(..\)\(..\).*$/02:\1:\2:\3:\4:\5/' > $out
+    '';
+  };
+
+  # dropUntil = pred: lst: let
+  #   drop-until-helper = pred: lst:
+  #     if (length lst) == 0 then [] else
+  #       if (pred (head lst)) then lst else (drop-until-helper pred (tail lst));
+  # in drop-until-helper pred lst;
+
+  # dropWhile = pred: dropUntil (el: !(pred el));
+
+  # is-whitespace = str: (builtins.match "^[[:space:]]*$" str) != null;
+
+  # stripWhitespace = str: let
+  #   lines = builtins.split "\n" str;
+  #   lines-front-stripped = dropWhile is-whitespace lines;
+  #   lines-rear-stripped = lib.reverseList
+  #     (dropWhile is-whitespace
+  #       (lib.reverseList lines-front-stripped));
+  # in concatStringsSep "\n" lines-rear-stripped;
+
+  host-ipv4 = config: hostname: let
+    domain = config.fudo.hosts.${hostname}.domain;
+    host-network = config.fudo.networks.${domain};
+  in host-network.hosts.${hostname}.ipv4-address;
+
+  host-ipv6 = config: hostname: let
+    domain = config.fudo.hosts.${hostname}.domain;
+    host-network = config.fudo.networks.${domain};
+  in host-network.hosts.${hostname}.ipv6-address;
+
+  host-ips = config: hostname: let
+    ipv4 = host-ipv4 config hostname;
+    ipv6 = host-ipv6 config hostname;
+    not-null = o: o != null;
+  in filter not-null [ ipv4 ipv6 ];
+
+in {
+  inherit host-ipv4 host-ipv6 host-ips;
+
+  generate-mac-address = hostname: interface: let
+    pkg = generate-mac-address hostname interface;
+  in removeSuffix "\n" (builtins.readFile "${pkg}");
+}
diff --git a/lib/passwd.nix b/lib/passwd.nix
new file mode 100644
index 0000000..97c2088
--- /dev/null
+++ b/lib/passwd.nix
@@ -0,0 +1,54 @@
+{ pkgs, ... }:
+
+with pkgs.lib;
+let
+  hash-ldap-passwd-pkg = name: passwd-file: pkgs.stdenv.mkDerivation {
+    name = "${name}-ldap-passwd";
+
+    phases = [ "installPhase" ];
+
+    buildInputs = with pkgs; [ openldap ];
+
+    installPhase = ''
+      slappasswd -T ${passwd-file} > $out
+    '';
+  };
+
+  hash-ldap-passwd = name: passwd-file:
+    builtins.readFile "${hash-ldap-passwd-pkg name passwd-file}";
+
+  generate-random-passwd = name: length: pkgs.stdenv.mkDerivation {
+    name = "${name}-random-passwd";
+
+    phases = [ "installPhase" ];
+
+    buildInputs = with pkgs; [ pwgen ];
+
+    installPhase = ''
+      pwgen --secure --num-passwords=1 ${toString length} > $out
+    '';
+  };
+
+  generate-stablerandom-passwd = name: { seed, length ? 20, ... }:
+    pkgs.stdenv.mkDerivation {
+      name = "${name}-stablerandom-passwd";
+
+      phases = [ "installPhase" ];
+
+      buildInputs = with pkgs; [ pwgen ];
+
+      installPhase = ''
+        echo "${name}-${seed}" > seedfile
+        pwgen --secure --num-passwords=1 -H seedfile ${toString length} > $out
+      '';
+    };
+
+in {
+  hash-ldap-passwd = hash-ldap-passwd;
+
+  random-passwd-file = name: length:
+    builtins.toPath "${generate-random-passwd name length}";
+
+  stablerandom-passwd-file = name: seed:
+    builtins.toPath "${generate-stablerandom-passwd name { seed = seed; }}";
+}
diff --git a/overlay.nix b/overlay.nix
new file mode 100644
index 0000000..86b7c29
--- /dev/null
+++ b/overlay.nix
@@ -0,0 +1,14 @@
+(final: prev: with builtins; {
+  lib = let
+    pkgs = prev;
+    lib = prev.lib;
+  in
+    lib // {
+      ip = import ./lib/ip.nix { inherit pkgs; };
+      dns = import ./lib/dns.nix { inherit pkgs; };
+      passwd = import ./lib/passwd.nix { inherit pkgs; };
+      lisp = import ./lib/lisp.nix { inherit pkgs; };
+      network = import ./lib/network.nix { inherit pkgs; };
+      fs = import ./lib/filesystem.nix { inherit pkgs; };
+    };
+})