wip: getgrnam_r and getgrgid_r

src/DB.zig

@@ -321,7 +321,7 @@ fn getGroup(self: *const DB, group: PackedGroup, buf: []u8) error{BufferTooSmall
 }
 
 // get a CGroup entry by name.
-fn getgrnam(self: *const DB, name: []const u8, buf: []u8) error{BufferTooSmall}!?CGroup {
+pub fn getgrnam(self: *const DB, name: []const u8, buf: []u8) error{BufferTooSmall}!?CGroup {
     const idx = bdz.search(self.bdz_groupname, name);
     if (idx >= self.header.num_groups) return null;
     const offset = self.idx_groupname2group[idx];
@@ -332,7 +332,7 @@ fn getgrnam(self: *const DB, name: []const u8, buf: []u8) error{BufferTooSmall}!
 }
 
 // get a CGroup entry by it's gid.
-fn getgrgid(self: *const DB, gid: u32, buf: []u8) error{BufferTooSmall}!?CGroup {
+pub fn getgrgid(self: *const DB, gid: u32, buf: []u8) error{BufferTooSmall}!?CGroup {
     const idx = bdz.search_u32(self.bdz_gid, gid);
     if (idx >= self.header.num_groups) return null;
     const offset = self.idx_gid2group[idx];
@@ -344,8 +344,8 @@ fn getgrgid(self: *const DB, gid: u32, buf: []u8) error{BufferTooSmall}!?CGroup
 
 fn pushStr(str: []const u8, buf: []u8, offset: *usize) [*:0]const u8 {
     const start = offset.*;
-    mem.copy(u8, buf[offset.*..], str);
-    buf[offset.* + str.len] = 0;
+    mem.copy(u8, buf[start..], str);
+    buf[start + str.len] = 0;
     offset.* += str.len + 1;
     return @ptrCast([*:0]const u8, &buf[start]);
 }

src/libnss.zig

@@ -95,13 +95,6 @@ fn init() void {
     };
 }
 
-fn shouldOmitMembers(envvar: []const u8, argv: [][*:0]u8) bool {
-    if (mem.eql(u8, envvar, "1")) return true;
-    if (mem.eql(u8, envvar, "0")) return false;
-    if (argv.len == 0) return false;
-    return mem.eql(u8, mem.sliceTo(argv[0], 0), "id");
-}
-
 export fn _nss_turbo_getpwuid_r(
     uid: c_uint,
     passwd: *CUser,
@@ -151,6 +144,55 @@ export fn _nss_turbo_getpwnam_r(
     }
 }
 
+export fn _nss_turbo_getgrgid_r(
+    gid: c_uint,
+    gr: *CGroup,
+    buffer: [*]u8,
+    buflen: usize,
+    errnop: *c_int,
+) c.enum_nss_status {
+    const db = getDb(errnop) orelse return c.NSS_STATUS_UNAVAIL;
+    if (db.getgrgid(gid, buffer[0..buflen])) |maybe_cgroup| {
+        if (maybe_cgroup) |cgroup| {
+            gr.* = cgroup;
+            return c.NSS_STATUS_SUCCESS;
+        } else {
+            errnop.* = @enumToInt(os.E.NOENT);
+            return c.NSS_STATUS_NOTFOUND;
+        }
+    } else |err| switch (err) {
+        error.BufferTooSmall => {
+            errnop.* = @enumToInt(os.E.RANGE);
+            return c.NSS_STATUS_TRYAGAIN;
+        },
+    }
+}
+
+export fn _nss_turbo_getgrnam_r(
+    name: [*:0]const u8,
+    group: *CGroup,
+    buffer: [*]u8,
+    buflen: usize,
+    errnop: *c_int,
+) c.enum_nss_status {
+    const db = getDb(errnop) orelse return c.NSS_STATUS_UNAVAIL;
+    const nameSlice = mem.sliceTo(name, 0);
+    if (db.getgrnam(nameSlice, buffer[0..buflen])) |maybe_cgroup| {
+        if (maybe_cgroup) |cgroup| {
+            group.* = cgroup;
+            return c.NSS_STATUS_SUCCESS;
+        } else {
+            errnop.* = @enumToInt(os.E.NOENT);
+            return c.NSS_STATUS_NOTFOUND;
+        }
+    } else |err| switch (err) {
+        error.BufferTooSmall => {
+            errnop.* = @enumToInt(os.E.RANGE);
+            return c.NSS_STATUS_TRYAGAIN;
+        },
+    }
+}
+
 fn getDb(errnop: *c_int) ?DB {
     global_init.call();
     if (global_state.file) |file| {
@@ -214,3 +256,29 @@ fn testVidmantas(u: CUser) !void {
     try testing.expectEqualStrings("Vidmantas Kaminskas", mem.sliceTo(u.pw_gecos, 0));
     try testing.expectEqualStrings("/bin/bash", mem.sliceTo(u.pw_shell, 0));
 }
+
+test "getgrgid_r and getgrnam_r" {
+    var tf = try File.TestDB.init(testing.allocator);
+    defer tf.deinit();
+    const turbonss_db_path_old = turbonss_db_path;
+    turbonss_db_path = tf.path;
+    defer {
+        turbonss_db_path = turbonss_db_path_old;
+    }
+
+    var buffer: [1024]u8 = undefined;
+    var errno: c_int = 0;
+    var group: CGroup = undefined;
+    try testing.expectEqual(
+        c.NSS_STATUS_SUCCESS,
+        _nss_turbo_getgrgid_r(128, &group, &buffer, buffer.len, &errno),
+    );
+    try testing.expectEqual(@as(c_int, 0), errno);
+    try testVidmantasGroup(group);
+}
+
+fn testVidmantasGroup(g: CGroup) !void {
+    try testing.expectEqual(@as(u32, 128), g.gid);
+    const members = g.members;
+    try testing.expect(members[0] != null);
+}