From 98db4ce0b216b1f17120c73bbf4d2b95dc706aea Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Motiejus=20Jak=C5=A1tys?= <motiejus@jakstys.lt>
Date: Thu, 7 Jul 2022 16:42:45 +0300
Subject: [PATCH] wip: setgrent/setpwent + endpwent/endgrent

---
 src/libnss.zig | 64 +++++++++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 58 insertions(+), 6 deletions(-)

diff --git a/src/libnss.zig b/src/libnss.zig
index e9e6487..dcd2552 100644
--- a/src/libnss.zig
+++ b/src/libnss.zig
@@ -5,6 +5,7 @@ const log = std.log;
 const mem = std.mem;
 const process = std.process;
 const once = std.once;
+const Mutex = std.Thread.Mutex;
 
 const DB = @import("DB.zig");
 const File = @import("File.zig");
@@ -13,6 +14,7 @@ const CGroup = @import("Group.zig").CGroup;
 const PackedGroup = @import("PackedGroup.zig");
 const CUser = @import("User.zig").CUser;
 const PackedUser = @import("PackedUser.zig");
+const ShellReader = @import("shell.zig").ShellReader;
 
 const c = @cImport({
     @cInclude("nss.h");
@@ -29,14 +31,18 @@ pub var log_level: std.log.Level = .err;
 // 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 = null,
-    getgrent_iterator: ?PackedGroup.Iterator = null,
+    file: File,
     omit_members: bool,
+
+    getpwent_iterator_mu: Mutex = Mutex{},
+    getpwent_iterator: ?PackedUser.Iterator = null,
+
+    getgrent_iterator_mu: Mutex = Mutex{},
+    getgrent_iterator: ?PackedGroup.Iterator = null,
 };
 
 // global_state is initialized on first call to an nss function
-var global_state: State = undefined;
+var global_state: ?State = null;
 var global_init = once(init);
 
 // assigns State from environment variables et al
@@ -193,10 +199,56 @@ export fn _nss_turbo_getgrnam_r(
     }
 }
 
+export fn _nss_turbo_setpwent(_: c_int) void {
+    global_init.call();
+    if (global_state) |*state| {
+        state.getpwent_iterator_mu.lock();
+        defer state.getpwent_iterator_mu.unlock();
+
+        state.getpwent_iterator = PackedUser.iterator(
+            state.file.db.users,
+            ShellReader{
+                .index = state.file.db.shell_index,
+                .blob = state.file.db.shell_blob,
+            },
+        );
+    }
+}
+
+export fn _nss_turbo_endpwent() void {
+    global_init.call();
+    if (global_state) |*state| {
+        state.getpwent_iterator_mu.lock();
+        defer state.getpwent_iterator_mu.unlock();
+        state.getpwent_iterator = null;
+    }
+}
+
+export fn _nss_turbo_setgrent(_: c_int) void {
+    global_init.call();
+    if (global_state) |*state| {
+        state.getgrent_iterator_mu.lock();
+        defer state.getgrent_iterator_mu.unlock();
+
+        state.getgrent_iterator = PackedGroup.iterator(
+            state.file.db.groups,
+        );
+    }
+}
+
+export fn _nss_turbo_endgrent() void {
+    global_init.call();
+    if (global_state) |*state| {
+        state.getgrent_iterator_mu.lock();
+        defer state.getgrent_iterator_mu.unlock();
+        state.getgrent_iterator = null;
+    }
+}
+
 fn getDb(errnop: *c_int) ?DB {
     global_init.call();
-    if (global_state.file) |file| {
-        return file.db;
+    if (global_state) |state| {
+        return state.file.db;
     } else {
         errnop.* = @enumToInt(os.E.AGAIN);
         return null;