From ee603c47ca2c40770dd5cd9a6899265a24f4af38 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Motiejus=20Jak=C5=A1tys?= <motiejus@jakstys.lt>
Date: Wed, 20 Apr 2022 07:19:34 +0300
Subject: [PATCH] wip so

---
 lib/File.zig     | 35 +++++++++++++++++++++++
 lib/State.zig    | 15 ----------
 lib/libnss.zig   | 74 ++++++++++++++++++++++++++++++++++++++++++++++++
 lib/test_all.zig |  2 +-
 4 files changed, 110 insertions(+), 16 deletions(-)
 create mode 100644 lib/File.zig
 delete mode 100644 lib/State.zig
 create mode 100644 lib/libnss.zig

diff --git a/lib/File.zig b/lib/File.zig
new file mode 100644
index 0000000..35d2765
--- /dev/null
+++ b/lib/File.zig
@@ -0,0 +1,35 @@
+const std = @import("std");
+const os = std.os;
+
+const DB = @import("DB.zig");
+const InvalidHeader = @import("header.zig").Invalid;
+
+const File = @This();
+
+db: DB,
+ptr: []align(4096) const u8,
+
+pub const Error = os.OpenError || os.FStatError || os.MMapError || InvalidHeader;
+pub fn open(fname: []const u8) Error!File {
+    const fd = try os.open(fname, os.O.RDONLY, 0);
+    var fd_open = true;
+    errdefer {
+        if (fd_open) os.close(fd);
+    }
+
+    const st = try os.fstat(fd);
+    const size = @intCast(u64, st.size);
+    const ptr = try os.mmap(null, size, os.PROT.READ, os.MAP.SHARED, fd, 0);
+    errdefer os.munmap(ptr);
+
+    os.close(fd);
+    fd_open = false;
+
+    const db = try DB.fromBytes(ptr);
+    return File{ .db = db, .ptr = ptr };
+}
+
+pub fn close(self: *File) void {
+    os.munmap(self.ptr);
+    self.* = undefined;
+}
diff --git a/lib/State.zig b/lib/State.zig
deleted file mode 100644
index 465f1a1..0000000
--- a/lib/State.zig
+++ /dev/null
@@ -1,15 +0,0 @@
-const std = @import("std");
-const os = std.os;
-
-const DB = @import("DB.zig");
-const PackedUser = @import("PackedUser.zig");
-
-// State is a type of the global variable holding the process state:
-// the DB handle and all the iterators.
-const State = struct {
-    DB: *const DB,
-    getpwent_iterator: *PackedUser.Iterator,
-};
-
-// state is initialized on library startup.
-var state: State = undefined;
diff --git a/lib/libnss.zig b/lib/libnss.zig
new file mode 100644
index 0000000..53d25b9
--- /dev/null
+++ b/lib/libnss.zig
@@ -0,0 +1,74 @@
+const std = @import("std");
+const os = std.os;
+const fmt = std.fmt;
+const mem = std.mem;
+
+const DB = @import("DB.zig");
+const File = @import("File.zig");
+const CGroup = @import("Group.zig").CGroup;
+const PackedGroup = @import("PackedGroup.zig");
+const CUser = @import("User.zig").CUser;
+const PackedUser = @import("PackedUser.zig");
+
+const c = @cImport({
+    @cInclude("stdlib.h");
+    @cInclude("nss.h");
+});
+
+export const turbonss_default_path: [:0]const u8 = "/etc/turbonss/db.turbo";
+
+// State is a type of the global variable holding the process state:
+// the DB handle and all the iterators.
+const State = struct {
+    file: ?File,
+    getpwent_iterator: ?PackedUser.Iterator,
+    getgrent_iterator: ?PackedGroup.Iterator,
+    omit_members: bool,
+    err_msg: [1024]u8,
+};
+
+// state is initialized on library startup.
+var state: State = undefined;
+
+// constructor
+export fn _turbo_init() void {
+    const fname = os.getenvZ("TURBONSS_DB") orelse turbonss_default_path[0..];
+    state.file = File.open(fname) catch |err| {
+        _ = fmt.bufPrint(&state.err_msg, "open {s}: {s}", .{ fname, @errorName(err) }) catch return;
+        return;
+    };
+
+    const omit_members_env = os.getenvZ("TURBONSS_OMIT_MEMBERS") orelse "auto";
+    state.omit_members = shouldOmitMembers(omit_members_env, os.argv);
+
+    return;
+}
+
+fn shouldOmitMembers(env: []const u8, argv: [][*:0]u8) bool {
+    if (mem.eql(u8, env, "1")) return true;
+    if (mem.eql(u8, env, "0")) return false;
+    if (argv.len == 0) return false;
+
+    return mem.eql(u8, mem.sliceTo(argv[0], 0), "id");
+}
+
+// destructor
+export fn _turbo_fini() void {
+    if (state.file) |*fooo|
+        fooo.close();
+}
+
+export fn _nss_turbo_getpwuid_r(
+    uid: c_uint,
+    res: *CUser,
+    buf: [*]u8,
+    len: usize,
+    errnop: *c_int,
+) c.enum_nss_status {
+    _ = uid;
+    _ = res;
+    _ = buf;
+    _ = len;
+    _ = errnop;
+    return 0;
+}
diff --git a/lib/test_all.zig b/lib/test_all.zig
index 990a59f..b3ba8e0 100644
--- a/lib/test_all.zig
+++ b/lib/test_all.zig
@@ -6,11 +6,11 @@ test "turbonss test suite" {
     _ = @import("DB.zig");
     _ = @import("Group.zig");
     _ = @import("header.zig");
+    _ = @import("libnss.zig");
     _ = @import("PackedGroup.zig");
     _ = @import("PackedUser.zig");
     _ = @import("padding.zig");
     _ = @import("shell.zig");
-    _ = @import("State.zig");
     _ = @import("User.zig");
     _ = @import("validate.zig");
 }