passwd fields now have sentinels

src/DB.zig

@@ -280,13 +280,13 @@ pub fn fromBytes(buf: []align(8) const u8) InvalidHeader!DB {
 }
 
 // dumps PackedGroup to []u8 and returns a CGroup.
-fn getGroup(self: *const DB, group: PackedGroup, buf: []u8) error{OutOfMemory}!CGroup {
+fn getGroup(self: *const DB, group: PackedGroup, buf: []u8) error{BufferTooSmall}!CGroup {
     const members_slice = self.groupmembers[group.members_offset..];
     var vit = compress.VarintSliceIteratorMust(members_slice);
     const num_members = vit.remaining;
 
     const ptr_end = @sizeOf(?[*:0]const u8) * (num_members + 1);
-    if (ptr_end > buf.len) return error.OutOfMemory;
+    if (ptr_end > buf.len) return error.BufferTooSmall;
     var member_ptrs = mem.bytesAsSlice(?[*:0]const u8, buf[0..ptr_end]);
     member_ptrs[member_ptrs.len - 1] = null;
     var buf_offset: usize = ptr_end;
@@ -297,7 +297,7 @@ fn getGroup(self: *const DB, group: PackedGroup, buf: []u8) error{OutOfMemory}!C
         const entry = PackedUser.fromBytes(self.users[member_offset << 3 ..]);
         const start = buf_offset;
         const name = entry.user.name();
-        if (buf_offset + name.len + 1 > buf.len) return error.OutOfMemory;
+        if (buf_offset + name.len + 1 > buf.len) return error.BufferTooSmall;
         mem.copy(u8, buf[buf_offset..], name);
         buf_offset += name.len;
         buf[buf_offset] = 0;
@@ -309,7 +309,7 @@ fn getGroup(self: *const DB, group: PackedGroup, buf: []u8) error{OutOfMemory}!C
     }
 
     const name = group.name();
-    if (buf_offset + name.len + 1 > buf.len) return error.OutOfMemory;
+    if (buf_offset + name.len + 1 > buf.len) return error.BufferTooSmall;
     mem.copy(u8, buf[buf_offset..], name);
     buf[buf_offset + name.len] = 0;
 
@@ -321,7 +321,7 @@ fn getGroup(self: *const DB, group: PackedGroup, buf: []u8) error{OutOfMemory}!C
 }
 
 // get a CGroup entry by name.
-fn getgrnam(self: *const DB, name: []const u8, buf: []u8) error{OutOfMemory}!?CGroup {
+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{OutOfMemory}!?CG
 }
 
 // get a CGroup entry by it's gid.
-fn getgrgid(self: *const DB, gid: u32, buf: []u8) error{OutOfMemory}!?CGroup {
+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];
@@ -342,12 +342,12 @@ fn getgrgid(self: *const DB, gid: u32, buf: []u8) error{OutOfMemory}!?CGroup {
     return try self.getGroup(group, buf);
 }
 
-fn pushStr(str: []const u8, buf: []u8, offset: *usize) [*]const u8 {
+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;
     offset.* += str.len + 1;
-    return @ptrCast([*]const u8, &buf[start]);
+    return @ptrCast([*:0]const u8, &buf[start]);
 }
 
 fn getUser(self: *const DB, user: PackedUser, buf: []u8) error{BufferTooSmall}!CUser {
@@ -725,7 +725,7 @@ test "getgrnam/getgrgid" {
 
     _ = try db.getgrnam("all", buf);
     buf.len -= 1;
-    try testing.expectError(error.OutOfMemory, db.getgrnam("all", buf));
+    try testing.expectError(error.BufferTooSmall, db.getgrnam("all", buf));
 }
 
 test "getpwnam/getpwuid" {

src/File.zig

@@ -43,11 +43,12 @@ pub const TestDB = struct {
     dir: testing.TmpDir,
     path: [:0]const u8,
 
-    pub fn init(allocator: Allocator, errc: *ErrCtx) !TestDB {
+    pub fn init(allocator: Allocator) !TestDB {
+        var errc = ErrCtx{};
         var corpus = try Corpus.testCorpus(allocator);
         defer corpus.deinit();
 
-        var db = try DB.fromCorpus(allocator, &corpus, errc);
+        var db = try DB.fromCorpus(allocator, &corpus, &errc);
         defer db.deinit(allocator);
 
         var tmp = testing.tmpDir(.{});

src/User.zig

@@ -145,13 +145,13 @@ pub fn fromReader(allocator: Allocator, err: *ErrCtx, reader: anytype) ![]User {
 }
 
 pub const CUser = extern struct {
-    pw_name: [*]const u8,
+    pw_name: [*:0]const u8,
-    pw_passwd: [*]const u8 = pw_passwd,
+    pw_passwd: [*:0]const u8 = pw_passwd,
     pw_uid: u32,
     pw_gid: u32,
-    pw_gecos: [*]const u8,
+    pw_gecos: [*:0]const u8,
-    pw_dir: [*]const u8,
+    pw_dir: [*:0]const u8,
-    pw_shell: [*]const u8,
+    pw_shell: [*:0]const u8,
 };
 
 const testing = std.testing;

src/libnss.zig

@@ -127,7 +127,7 @@ export fn _nss_turbo_getpwuid_r(
 }
 
 export fn _nss_turbo_getpwnam_r(
-    name: [*:0]u8,
+    name: [*:0]const u8,
     passwd: *CUser,
     buffer: [*]u8,
     buflen: usize,
@@ -164,17 +164,54 @@ fn get_db(errnop: *c_int) ?DB {
 
 const testing = std.testing;
 
-test "nss_turbo_getpwuid_r" {
+test "getpwuid_r and getpwnam_r" {
-    var errc = ErrCtx{};
+    var tf = try File.TestDB.init(testing.allocator);
-    var tf = try File.TestDB.init(testing.allocator, &errc);
     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 passwd: CUser = undefined;
     var buffer: [1024]u8 = undefined;
     var errno: c_int = 0;
 
-    const status = _nss_turbo_getpwuid_r(0, &passwd, &buffer, buffer.len, &errno);
+    var passwd: CUser = undefined;
+    try testing.expectEqual(
+        c.NSS_STATUS_SUCCESS,
+        _nss_turbo_getpwuid_r(128, &passwd, &buffer, buffer.len, &errno),
+    );
     try testing.expectEqual(@as(c_int, 0), errno);
-    try testing.expectEqual(c.NSS_STATUS_SUCCESS, status);
+    try testVidmantas(passwd);
+
+    passwd = undefined;
+    try testing.expectEqual(
+        c.NSS_STATUS_SUCCESS,
+        _nss_turbo_getpwnam_r("vidmantas", &passwd, &buffer, buffer.len, &errno),
+    );
+    try testing.expectEqual(@as(c_int, 0), errno);
+    try testVidmantas(passwd);
+
+    passwd = undefined;
+    try testing.expectEqual(
+        c.NSS_STATUS_NOTFOUND,
+        _nss_turbo_getpwnam_r("does not exist", &passwd, &buffer, buffer.len, &errno),
+    );
+    try testing.expectEqual(@enumToInt(os.E.NOENT), @intCast(u16, errno));
+
+    passwd = undefined;
+    var small_buffer: [1]u8 = undefined;
+    try testing.expectEqual(
+        c.NSS_STATUS_TRYAGAIN,
+        _nss_turbo_getpwuid_r(0, &passwd, &small_buffer, small_buffer.len, &errno),
+    );
+    try testing.expectEqual(@enumToInt(os.E.RANGE), @intCast(u16, errno));
+}
+
+fn testVidmantas(u: CUser) !void {
+    try testing.expectEqualStrings("vidmantas", mem.sliceTo(u.pw_name, 0));
+    try testing.expectEqual(@as(u32, 128), u.pw_uid);
+    try testing.expectEqual(@as(u32, 128), u.pw_gid);
+    try testing.expectEqualStrings("Vidmantas Kaminskas", mem.sliceTo(u.pw_gecos, 0));
+    try testing.expectEqualStrings("/bin/bash", mem.sliceTo(u.pw_shell, 0));
 }