finish(?) turbonss-getent

build.zig

@@ -80,6 +80,17 @@ pub fn build(b: *zbs.Builder) void {
         exe.install();
     }
 
+    {
+        const exe = b.addExecutable("turbo-getent", "src/turbo-getent.zig");
+        exe.strip = strip;
+        exe.linkLibC();
+        exe.linkLibrary(bdz);
+        exe.addIncludeDir("deps/cmph/src");
+        exe.setTarget(target);
+        exe.setBuildMode(mode);
+        exe.install();
+    }
+
     {
         const so = b.addSharedLibrary("nss_turbo", "src/libnss.zig", .{
             .versioned = builtin.Version{

src/PackedGroup.zig

@@ -36,7 +36,7 @@ members_offset: u64,
 
 pub const Entry = struct {
     group: PackedGroup,
-    next: ?[]const u8,
+    end: usize,
 };
 
 pub fn fromBytes(bytes: []const u8) Entry {
@@ -47,11 +47,6 @@ pub fn fromBytes(bytes: []const u8) Entry {
         error.Overflow => unreachable,
     };
     const end_blob = end_strings + members_offset.bytes_read;
-    const next_start = pad.roundUp(usize, alignment_bits, end_blob);
-
-    var next: ?[]const u8 = null;
-    if (next_start < bytes.len)
-        next = bytes[next_start..];
 
     return Entry{
         .group = PackedGroup{
@@ -59,7 +54,7 @@ pub fn fromBytes(bytes: []const u8) Entry {
             .groupdata = bytes[start_blob..end_strings],
             .members_offset = members_offset.value,
         },
-        .next = next,
+        .end = pad.roundUp(usize, alignment_bits, end_blob),
     };
 }
 
@@ -69,20 +64,26 @@ fn validateUtf8(s: []const u8) InvalidRecord!void {
 }
 
 pub const Iterator = struct {
-    section: ?[]const u8,
+    section: []const u8,
+    nextStart: usize = 0,
+    idx: u32 = 0,
+    total: u32,
 
     pub fn next(it: *Iterator) ?PackedGroup {
-        if (it.section) |section| {
+        if (it.idx == it.total) return null;
-            const entry = fromBytes(section);
+
-            it.section = entry.next;
+        const entry = fromBytes(it.section[it.nextStart..]);
-            return entry.group;
+        it.nextStart += entry.end;
-        }
+        it.idx += 1;
-        return null;
+        return entry.group;
     }
 };
 
-pub fn iterator(section: []const u8) Iterator {
+pub fn iterator(section: []const u8, total: u32) Iterator {
-    return Iterator{ .section = section };
+    return Iterator{
+        .section = section,
+        .total = total,
+    };
 }
 
 pub fn gid(self: *const PackedGroup) u32 {
@@ -139,7 +140,7 @@ test "PackedGroup construct" {
     }
 
     var i: u29 = 0;
-    var it = PackedGroup.iterator(buf.items);
+    var it = PackedGroup.iterator(buf.items, groups.len);
     while (it.next()) |group| : (i += 1) {
         try testing.expectEqual(groups[i].gid, group.gid());
         try testing.expectEqualStrings(groups[i].name, group.name());

src/PackedUser.zig

@@ -111,8 +111,7 @@ pub const Iterator = struct {
     total: u32,
 
     pub fn next(it: *Iterator) ?PackedUser {
-        if (it.idx == it.total)
+        if (it.idx == it.total) return null;
-            return null;
 
         const entry = PackedUser.fromBytes(it.section[it.nextStart..]);
         it.nextStart += entry.end;

src/libnss.zig

@@ -296,6 +296,7 @@ fn setgrent(state: *State) void {
     defer state.getgrent_iterator_mu.unlock();
     state.getgrent_iterator = PackedGroup.iterator(
         state.file.db.groups,
+        state.file.db.header.num_groups,
     );
 }
 

src/turbo-getent.zig

@@ -10,6 +10,7 @@ const flags = @import("flags.zig");
 const DB = @import("DB.zig");
 const File = @import("File.zig");
 const PackedUser = @import("PackedUser.zig");
+const PackedGroup = @import("PackedGroup.zig");
 const User = @import("User.zig");
 
 const Mode = enum { group, passwd };
@@ -100,7 +101,7 @@ fn execute(
 
 fn passwd(stdout: anytype, db: *const DB, keys: []const [*:0]const u8) u8 {
     if (keys.len == 0)
-        return passwd_all(stdout, db);
+        return passwdAll(stdout, db);
     var some_notfound = false;
     const shell_reader = db.shellReader();
     for (keys) |key| {
@@ -122,7 +123,7 @@ fn passwd(stdout: anytype, db: *const DB, keys: []const [*:0]const u8) u8 {
     return if (some_notfound) 2 else 0;
 }
 
-fn passwd_all(stdout: anytype, db: *const DB) u8 {
+fn passwdAll(stdout: anytype, db: *const DB) u8 {
     const shell_reader = db.shellReader();
     var it = PackedUser.iterator(db.users, db.header.num_users, shell_reader);
     while (it.next()) |packed_user| {
@@ -134,7 +135,7 @@ fn passwd_all(stdout: anytype, db: *const DB) u8 {
 
 fn group(stdout: anytype, db: *const DB, keys: []const [*:0]const u8) u8 {
     if (keys.len == 0)
-        return group_all(stdout, db);
+        return groupAll(stdout, db);
     var some_notfound = false;
 
     for (keys) |key| {
@@ -149,38 +150,48 @@ fn group(stdout: anytype, db: *const DB, keys: []const [*:0]const u8) u8 {
             continue;
         };
 
-        // not converting to Group to save a few memory allocations.
+        if (printGroup(stdout, db, &g)) |exit_code|
-        stdout.print("{s}:x:{d}:", .{ g.name(), g.gid() }) catch return 3;
+            return exit_code;
-
-        // TODO: move member iteration from here and DB.packCGroup
-        // to a common place.
-        const members_slice = db.groupmembers[g.members_offset..];
-        var vit = compress.varintSliceIteratorMust(members_slice);
-        var it = compress.deltaDecompressionIterator(&vit);
-
-        // lines will be buffered, but flushed on every EOL.
-        var line_writer = io.bufferedWriter(stdout);
-        var i: usize = 0;
-        while (it.nextMust()) |member_offset| : (i += 1) {
-            const puser = PackedUser.fromBytes(db.users[member_offset << 3 ..]);
-            const name = puser.user.name();
-            if (i != 0)
-                _ = line_writer.write(",") catch return 3;
-            _ = line_writer.write(name) catch return 3;
-        }
-        _ = line_writer.write("\n") catch return 3;
-        line_writer.flush() catch return 3;
     }
 
     return if (some_notfound) 2 else 0;
 }
 
-fn group_all(stdout: anytype, db: *const DB) u8 {
+fn groupAll(stdout: anytype, db: *const DB) u8 {
-    _ = stdout;
+    var it = PackedGroup.iterator(db.groups, db.header.num_groups);
-    _ = db;
+    while (it.next()) |g|
+        if (printGroup(stdout, db, &g)) |exit_code|
+            return exit_code;
+
     return 0;
 }
 
+fn printGroup(stdout: anytype, db: *const DB, g: *const PackedGroup) ?u8 {
+    // not converting to Group to save a few memory allocations.
+    stdout.print("{s}:x:{d}:", .{ g.name(), g.gid() }) catch return 3;
+
+    // TODO: move member iteration from here and DB.packCGroup
+    // to a common place.
+    const members_slice = db.groupmembers[g.members_offset..];
+    var vit = compress.varintSliceIteratorMust(members_slice);
+    var it = compress.deltaDecompressionIterator(&vit);
+
+    // lines will be buffered, but flushed on every EOL.
+    var line_writer = io.bufferedWriter(stdout);
+    var i: usize = 0;
+    while (it.nextMust()) |member_offset| : (i += 1) {
+        const puser = PackedUser.fromBytes(db.users[member_offset << 3 ..]);
+        const name = puser.user.name();
+        if (i != 0)
+            _ = line_writer.write(",") catch return 3;
+        _ = line_writer.write(name) catch return 3;
+    }
+    _ = line_writer.write("\n") catch return 3;
+    line_writer.flush() catch return 3;
+
+    return null;
+}
+
 const testing = std.testing;
 
 test "turbo-getent passwd" {
@@ -213,7 +224,7 @@ test "turbo-getent passwd" {
     }
 }
 
-test "turbo-getent passwd_all" {
+test "turbo-getent passwdAll" {
     var tf = try File.TestDB.init(testing.allocator);
     defer tf.deinit();
     var stdout = ArrayList(u8).init(testing.allocator);
@@ -278,3 +289,30 @@ test "turbo-getent group" {
         try testing.expectEqualStrings(want, stdout.items);
     }
 }
+
+test "turbo-getent groupAll" {
+    var tf = try File.TestDB.init(testing.allocator);
+    defer tf.deinit();
+    var stdout = ArrayList(u8).init(testing.allocator);
+    defer stdout.deinit();
+    var stderr = ArrayList(u8).init(testing.allocator);
+    defer stderr.deinit();
+
+    {
+        const args = &[_][*:0]const u8{
+            "--db",
+            tf.path,
+            "group",
+        };
+        const got = execute(stdout.writer(), stderr.writer(), args);
+        try testing.expectEqual(got, 0);
+        const want =
+            \\root:x:0:
+            \\vidmantas:x:128:
+            \\all:x:9999:NameNameNameNameNameNameNameName,root,svc-bar,vidmantas
+            \\service-group:x:100000:root,vidmantas
+            \\
+        ;
+        try testing.expectEqualStrings(want, stdout.items);
+    }
+}