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DB.header is becoming a pointer

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Also, move User, PackedUser, Group, PackedGroup to better-fit places.
This commit is contained in:
Motiejus Jakštys 2022-03-25 14:31:56 +02:00 committed by Motiejus Jakštys
parent 347f0a1392
commit fad7c9fbaf
10 changed files with 682 additions and 657 deletions
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6
lib/Corpus.zig
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@ -9,8 +9,8 @@ const StringHashMap = std.StringHashMap;
const MultiArrayList = std.MultiArrayList;
const ArrayListUnmanaged = std.ArrayListUnmanaged;
const User = @import("user.zig").User;
const Group = @import("group.zig").Group;
const User = @import("User.zig");
const Group = @import("Group.zig");
pub const Corpus = @This();
@ -152,7 +152,7 @@ fn testUser(name: []const u8) User {
}
const testing = std.testing;
const someMembers = @import("group.zig").someMembers;
const someMembers = @import("Group.zig").someMembers;
test "users compare function" {
const a = testUser("a");

163
lib/DB.zig
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@ -13,14 +13,15 @@ const BoundedArray = std.BoundedArray;
const Corpus = @import("Corpus.zig");
const pad = @import("padding.zig");
const compress = @import("compress.zig");
const PackedUser = @import("user.zig").PackedUser;
const User = @import("user.zig").User;
const Group = @import("group.zig").Group;
const GroupStored = @import("group.zig").GroupStored;
const PackedGroup = @import("group.zig").PackedGroup;
const PackedUser = @import("PackedUser.zig");
const User = @import("User.zig");
const Group = @import("Group.zig");
const PackedGroup = @import("PackedGroup.zig");
const GroupStored = PackedGroup.GroupStored;
const ShellSections = @import("shell.zig").ShellWriter.ShellSections;
const ShellReader = @import("shell.zig").ShellReader;
const ShellWriter = @import("shell.zig").ShellWriter;
const InvalidHeader = @import("header.zig").Invalid;
const Header = @import("header.zig").Header;
const max_shells = @import("shell.zig").max_shells;
const section_length_bits = @import("header.zig").section_length_bits;
@ -32,7 +33,7 @@ const zeroes = &[_]u8{0} ** section_length;
const DB = @This();
// All sections, as they end up in the DB. Order is important.
header: Header,
header: *const Header,
bdz_gid: []const u8,
bdz_groupname: []const u8,
bdz_uid: []const u8,
@ -57,13 +58,13 @@ pub fn fromCorpus(
const uids = corpus.users.items(.uid);
const unames = corpus.users.items(.name);
var bdz_gid = try cmph.packU32(allocator, gids);
const bdz_gid = try cmph.packU32(allocator, gids);
errdefer allocator.free(bdz_gid);
var bdz_groupname = try cmph.packStr(allocator, gnames);
const bdz_groupname = try cmph.packStr(allocator, gnames);
errdefer allocator.free(bdz_groupname);
var bdz_uid = try cmph.packU32(allocator, uids);
const bdz_uid = try cmph.packU32(allocator, uids);
errdefer allocator.free(bdz_uid);
const bdz_username = try cmph.packStr(allocator, unames);
@ -72,35 +73,38 @@ pub fn fromCorpus(
var shell = try shellSections(allocator, corpus);
defer shell.deinit();
var additional_gids = try additionalGids(allocator, corpus);
const additional_gids = try additionalGids(allocator, corpus);
errdefer allocator.free(additional_gids.blob);
defer allocator.free(additional_gids.idx2offset);
var users = try usersSection(allocator, corpus, &additional_gids, &shell);
allocator.free(additional_gids.idx2offset);
const users = try usersSection(allocator, corpus, &additional_gids, &shell);
errdefer allocator.free(users.blob);
defer allocator.free(users.idx2offset);
var groupmembers = try groupMembers(allocator, corpus, users.idx2offset);
const groupmembers = try groupMembers(allocator, corpus, users.idx2offset);
errdefer allocator.free(groupmembers.blob);
defer allocator.free(groupmembers.idx2offset);
var groups = try groupsSection(allocator, corpus, groupmembers.idx2offset);
allocator.free(groupmembers.idx2offset);
const groups = try groupsSection(allocator, corpus, groupmembers.idx2offset);
errdefer allocator.free(groups.blob);
defer allocator.free(groups.idx2offset);
var idx_gid2group = try bdzIdx(u32, allocator, bdz_gid, gids, groups.idx2offset);
const idx_gid2group = try bdzIdx(u32, allocator, bdz_gid, gids, groups.idx2offset);
errdefer allocator.free(idx_gid2group);
var idx_groupname2group = try bdzIdx([]const u8, allocator, bdz_groupname, gnames, groups.idx2offset);
allocator.free(groups.idx2offset);
const idx_groupname2group = try bdzIdx([]const u8, allocator, bdz_groupname, gnames, groups.idx2offset);
errdefer allocator.free(idx_groupname2group);
var idx_uid2user = try bdzIdx(u32, allocator, bdz_uid, uids, users.idx2offset);
const idx_uid2user = try bdzIdx(u32, allocator, bdz_uid, uids, users.idx2offset);
errdefer allocator.free(idx_uid2user);
var idx_name2user = try bdzIdx([]const u8, allocator, bdz_username, unames, users.idx2offset);
allocator.free(users.idx2offset);
const idx_name2user = try bdzIdx([]const u8, allocator, bdz_username, unames, users.idx2offset);
errdefer allocator.free(idx_name2user);
const header = Header{
const header = try allocator.create(Header);
errdefer allocator.destroy(header);
header.* = Header{
.nblocks_shell_blob = nblocks(u8, shell.blob.constSlice()),
.num_shells = shell.len,
.num_groups = groups.len,
@ -134,6 +138,23 @@ pub fn fromCorpus(
};
}
pub fn deinit(self: *DB, allocator: Allocator) void {
allocator.destroy(self.header);
allocator.free(self.bdz_gid);
allocator.free(self.bdz_groupname);
allocator.free(self.bdz_uid);
allocator.free(self.bdz_username);
allocator.free(self.idx_gid2group);
allocator.free(self.idx_groupname2group);
allocator.free(self.idx_uid2user);
allocator.free(self.idx_name2user);
allocator.free(self.groups);
allocator.free(self.users);
allocator.free(self.groupmembers);
allocator.free(self.additional_gids);
self.* = undefined;
}
const DB_fields = meta.fields(DB);
pub fn iov(self: *const DB) BoundedArray(os.iovec_const, DB_fields.len * 2) {
var result = BoundedArray(os.iovec_const, DB_fields.len * 2).init(0) catch unreachable;
@ -141,7 +162,7 @@ pub fn iov(self: *const DB) BoundedArray(os.iovec_const, DB_fields.len * 2) {
comptime assertDefinedLayout(field.field_type);
const value = @field(self, field.name);
const bytes: []const u8 = switch (@TypeOf(value)) {
Header => mem.asBytes(&value),
*const Header => mem.asBytes(value),
else => mem.sliceAsBytes(value),
};
result.appendAssumeCapacity(os.iovec_const{
@ -159,58 +180,44 @@ pub fn iov(self: *const DB) BoundedArray(os.iovec_const, DB_fields.len * 2) {
return result;
}
pub fn fromBytes(buf: []const u8) Header.Invalid!DB {
const header = try Header.fromBytes(buf);
pub fn fromBytes(buf: []align(8) const u8) InvalidHeader!DB {
const header = try Header.fromBytes(buf[0..@sizeOf(Header)]);
// At first the tuple below had field names too, but moved it to comments,
// because it segfaulted. https://github.com/ziglang/zig/issues/3915 and
// https://paste.sr.ht/~motiejus/2830736e796801517c1fa8639be6615cd56ada27
const lengths = .{
.{ "bdz_gid", header.nblocks_bdz_gid },
.{ "bdz_groupname", header.nblocks_bdz_groupname },
.{ "bdz_uid", header.nblocks_bdz_uid },
.{ "bdz_username", header.nblocks_bdz_username },
.{ "idx_gid2group", nblocks_n(header.num_groups * 4) },
.{ "idx_groupname2group", nblocks_n(header.num_groups * 4) },
.{ "idx_uid2user", nblocks_n(header.num_users * 4) },
.{ "idx_name2user", nblocks_n(header.num_users * 4) },
.{ "shell_index", nblocks_n(header.num_shells * 2) },
.{ "shell_blob", header.nblocks_shell_blob },
.{ "groups", header.nblocks_groups },
.{ "users", header.nblocks_users },
.{ "groupmembers", header.nblocks_groupmembers },
.{ "additional_gids", header.nblocks_additional_gids },
header.nblocks_bdz_gid, // bdz_gid
header.nblocks_bdz_groupname, // bdz_groupname
header.nblocks_bdz_uid, // bdz_uid
header.nblocks_bdz_username, // bdz_username
nblocks_n(u32, header.num_groups * 4), // idx_gid2group
nblocks_n(u32, header.num_groups * 4), // idx_groupname2group
nblocks_n(u32, header.num_users * 4), // idx_uid2user
nblocks_n(u32, header.num_users * 4), // idx_name2user
nblocks_n(u16, header.num_shells * 2), // shell_index
header.nblocks_shell_blob, // shell_blob
header.nblocks_groups, // groups
header.nblocks_users, // users
header.nblocks_groupmembers, // groupmembers
header.nblocks_additional_gids, // additional_gids
};
var result: DB = undefined;
result.header = header;
var offset = comptime nblocks_n(usize, @sizeOf(Header));
comptime assert(DB_fields[0].name == "header");
var offset = comptime nblocks_n(u64, @sizeOf(Header));
comptime assert(mem.eql(u8, DB_fields[0].name, "header"));
inline for (DB_fields[1..]) |field, i| {
assert(lengths[i][0] == field.name);
const start = offset << 6;
const end = (offset + lengths[i][1]) << 6;
const value = mem.bytesAsValue(field.field_type, buf[start..end]);
const start = offset << section_length_bits;
const end = (offset + lengths[i]) << section_length_bits;
const slice_type = meta.Child(field.field_type);
const value = mem.bytesAsSlice(slice_type, buf[start..end]);
@field(result, field.name) = value;
offset += lengths[i][1];
offset += lengths[i];
}
return result;
}
pub fn deinit(self: *DB, allocator: Allocator) void {
allocator.free(self.bdz_gid);
allocator.free(self.bdz_groupname);
allocator.free(self.bdz_uid);
allocator.free(self.bdz_username);
allocator.free(self.idx_gid2group);
allocator.free(self.idx_groupname2group);
allocator.free(self.idx_uid2user);
allocator.free(self.idx_name2user);
allocator.free(self.groups);
allocator.free(self.users);
allocator.free(self.groupmembers);
allocator.free(self.additional_gids);
self.* = undefined;
}
fn shellSections(
allocator: Allocator,
corpus: *const Corpus,
@ -414,12 +421,10 @@ fn bdzIdx(
keys: []const T,
idx2offset: []const u32,
) error{OutOfMemory}![]const u32 {
const search_fn = comptime blk: {
switch (T) {
u32 => break :blk bdz.search_u32,
[]const u8 => break :blk bdz.search,
const search_fn = switch (T) {
u32 => bdz.search_u32,
[]const u8 => bdz.search,
else => unreachable,
}
};
assert(keys.len <= math.maxInt(u32));
var result = try allocator.alloc(u32, keys.len);
@ -432,13 +437,14 @@ fn bdzIdx(
fn nblocks_n(comptime T: type, nbytes: usize) T {
const B = switch (T) {
u8 => u14,
u16 => u22,
u32 => u38,
u64 => u70,
else => @compileError("only u8, u32 and u64 are supported"),
else => @compileError("got " ++ @typeName(T) ++ ", only u8, u32 and u64 are supported"),
};
const upper = pad.roundUp(B, section_length_bits, @intCast(B, nbytes));
assert(upper & (section_length - 1) == 0);
return @truncate(T, upper >> 6);
return @truncate(T, upper >> section_length_bits);
}
// nblocks returns how many blocks a particular slice will take.
@ -450,7 +456,8 @@ fn assertDefinedLayout(comptime T: type) void {
return switch (T) {
u8, u16, u32, u64 => {},
else => switch (@typeInfo(T)) {
.Array, .Pointer => assertDefinedLayout(meta.Elem(T)),
.Array => assertDefinedLayout(meta.Elem(T)),
.Pointer => |info| assertDefinedLayout(info.child),
.Enum => assertDefinedLayout(meta.Tag(T)),
.Struct => {
if (meta.containerLayout(T) == .Auto)
@ -505,8 +512,18 @@ test "test groups, group members and users" {
const fd = try os.memfd_create("test_turbonss_db", 0);
defer os.close(fd);
const written = try os.writev(fd, db.iov().constSlice());
try testing.expect(written != 0);
const len = try os.writev(fd, db.iov().constSlice());
const buf = try os.mmap(null, len, os.PROT.READ, os.MAP.SHARED, fd, 0);
const db2 = try fromBytes(buf);
try testing.expectEqual(corpus.groups.len, db.header.num_groups);
try testing.expectEqual(corpus.users.len, db.header.num_users);
try testing.expectEqual(db.header.num_groups, db2.header.num_groups);
try testing.expectEqual(db.header.num_users, db2.header.num_users);
const num_groups = db2.header.num_groups;
const num_users = db2.header.num_users;
try testing.expectEqualSlices(u32, db.idx_gid2group, db2.idx_gid2group[0..num_groups]);
try testing.expectEqualSlices(u32, db.idx_uid2user, db2.idx_uid2user[0..num_users]);
}
test "additionalGids" {

61
lib/Group.zig Normal file
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@ -0,0 +1,61 @@
const std = @import("std");
const mem = std.mem;
const Allocator = mem.Allocator;
const BufSet = std.BufSet;
const Group = @This();
gid: u32,
name: []const u8,
members: BufSet,
pub fn clone(self: *const Group, allocator: Allocator) Allocator.Error!Group {
var name = try allocator.dupe(u8, self.name);
return Group{
.gid = self.gid,
.name = name,
.members = try self.members.cloneWithAllocator(allocator),
};
}
pub fn deinit(self: *Group, allocator: Allocator) void {
allocator.free(self.name);
self.members.deinit();
self.* = undefined;
}
// someMembers constructs a bufset from an allocator and a list of strings.
pub fn someMembers(
allocator: Allocator,
members: []const []const u8,
) Allocator.Error!BufSet {
var bufset = BufSet.init(allocator);
errdefer bufset.deinit();
for (members) |member|
try bufset.insert(member);
return bufset;
}
const testing = std.testing;
test "Group.clone" {
var allocator = testing.allocator;
var arena = std.heap.ArenaAllocator.init(allocator);
defer arena.deinit();
var members = BufSet.init(allocator);
try members.insert("member1");
try members.insert("member2");
defer members.deinit();
var cloned = try members.cloneWithAllocator(arena.allocator());
cloned.remove("member1");
try cloned.insert("member4");
try testing.expect(members.contains("member1"));
try testing.expect(!members.contains("member4"));
try testing.expect(!cloned.contains("member1"));
try testing.expect(cloned.contains("member4"));
}

149
lib/PackedGroup.zig Normal file
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@ -0,0 +1,149 @@
const std = @import("std");
const pad = @import("padding.zig");
const validate = @import("validate.zig");
const compress = @import("compress.zig");
const InvalidRecord = validate.InvalidRecord;
const mem = std.mem;
const Allocator = mem.Allocator;
const ArrayList = std.ArrayList;
const BufSet = std.BufSet;
const PackedGroup = @This();
pub const GroupStored = struct {
gid: u32,
name: []const u8,
members_offset: u64,
};
pub const alignment_bits = 3;
const Inner = packed struct {
gid: u32,
padding: u3 = 0,
groupname_len: u5,
pub fn groupnameLen(self: *const Inner) usize {
return @as(usize, self.groupname_len) + 1;
}
};
inner: *const Inner,
groupdata: []const u8,
members_offset: u64,
pub const Entry = struct {
group: PackedGroup,
next: ?[]const u8,
};
pub fn fromBytes(bytes: []const u8) Entry {
const inner = mem.bytesAsValue(Inner, bytes[0..@sizeOf(Inner)]);
const start_blob = @sizeOf(Inner);
const end_strings = @sizeOf(Inner) + inner.groupnameLen();
const members_offset = compress.uvarint(bytes[end_strings..]) catch |err| switch (err) {
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{
.inner = inner,
.groupdata = bytes[start_blob..end_strings],
.members_offset = members_offset.value,
},
.next = next,
};
}
fn validateUtf8(s: []const u8) InvalidRecord!void {
if (!std.unicode.utf8ValidateSlice(s))
return error.InvalidRecord;
}
pub const Iterator = struct {
section: ?[]const u8,
pub fn next(it: *Iterator) ?PackedGroup {
if (it.section) |section| {
const entry = fromBytes(section);
it.section = entry.next;
return entry.group;
}
return null;
}
};
pub fn iterator(section: []const u8) Iterator {
return Iterator{ .section = section };
}
pub fn gid(self: *const PackedGroup) u32 {
return self.inner.gid;
}
pub fn membersOffset(self: *const PackedGroup) u64 {
return self.members_offset;
}
pub fn name(self: *const PackedGroup) []const u8 {
return self.groupdata;
}
pub fn packTo(
arr: *ArrayList(u8),
group: GroupStored,
) error{ InvalidRecord, OutOfMemory }!void {
std.debug.assert(arr.items.len & 7 == 0);
try validate.utf8(group.name);
const len = try validate.downCast(u5, group.name.len - 1);
const inner = Inner{ .gid = group.gid, .groupname_len = len };
try arr.*.appendSlice(mem.asBytes(&inner));
try arr.*.appendSlice(group.name);
try compress.appendUvarint(arr, group.members_offset);
}
const testing = std.testing;
test "PackedGroup alignment" {
try testing.expectEqual(@sizeOf(PackedGroup) * 8, @bitSizeOf(PackedGroup));
}
test "construct PackedGroups" {
var buf = ArrayList(u8).init(testing.allocator);
defer buf.deinit();
const groups = [_]GroupStored{
GroupStored{
.gid = 1000,
.name = "sudo",
.members_offset = 1,
},
GroupStored{
.gid = std.math.maxInt(u32),
.name = "Name" ** 8, // 32
.members_offset = std.math.maxInt(u64),
},
};
for (groups) |group| {
try PackedGroup.packTo(&buf, group);
try pad.arrayList(&buf, PackedGroup.alignment_bits);
}
var i: u29 = 0;
var it = PackedGroup.iterator(buf.items);
while (it.next()) |group| : (i += 1) {
try testing.expectEqual(groups[i].gid, group.gid());
try testing.expectEqualStrings(groups[i].name, group.name());
try testing.expectEqual(groups[i].members_offset, group.membersOffset());
}
try testing.expectEqual(groups.len, i);
}

288
lib/PackedUser.zig Normal file
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@ -0,0 +1,288 @@
const std = @import("std");
const assert = std.debug.assert;
const mem = std.mem;
const math = std.math;
const Allocator = mem.Allocator;
const ArrayList = std.ArrayList;
const StringHashMap = std.StringHashMap;
const pad = @import("padding.zig");
const validate = @import("validate.zig");
const compress = @import("compress.zig");
const shellImport = @import("shell.zig");
const InvalidRecord = validate.InvalidRecord;
const User = @import("User.zig");
const PackedUser = @This();
pub const alignment_bits = 3;
const Inner = packed struct {
uid: u32,
gid: u32,
shell_len_or_idx: u8,
shell_here: bool,
name_is_a_suffix: bool,
home_len: u6,
name_len: u5,
gecos_len: u11,
fn homeLen(self: *const Inner) usize {
return @as(u32, self.home_len) + 1;
}
fn nameStart(self: *const Inner) usize {
const name_len = self.nameLen();
if (self.name_is_a_suffix) {
return self.homeLen() - name_len;
} else return self.homeLen();
}
fn nameLen(self: *const Inner) usize {
return @as(u32, self.name_len) + 1;
}
fn gecosStart(self: *const Inner) usize {
if (self.name_is_a_suffix) {
return self.homeLen();
} else return self.homeLen() + self.nameLen();
}
fn gecosLen(self: *const Inner) usize {
return self.gecos_len;
}
fn maybeShellStart(self: *const Inner) usize {
assert(self.shell_here);
return self.gecosStart() + self.gecosLen();
}
fn shellLen(self: *const Inner) usize {
return @as(u32, self.shell_len_or_idx) + 1;
}
// stringLength returns the length of the blob storing string values.
fn stringLength(self: *const Inner) usize {
var result: usize = self.homeLen() + self.gecosLen();
if (!self.name_is_a_suffix)
result += self.nameLen();
if (self.shell_here)
result += self.shellLen();
return result;
}
};
// PackedUser does not allocate; it re-interprets the "bytes" blob
// field. Both of those fields are pointers to "our representation" of
// that field.
inner: *const Inner,
bytes: []const u8,
additional_gids_offset: u64,
pub const Entry = struct {
user: PackedUser,
next: ?[]const u8,
};
// TODO(motiejus) provide a way to return an entry without decoding the
// additional_gids_offset:
// - will not return the 'next' slice.
// - cannot throw an Overflow error.
pub fn fromBytes(bytes: []const u8) Entry {
const inner = mem.bytesAsValue(Inner, bytes[0..@sizeOf(Inner)]);
const start_blob = @sizeOf(Inner);
const end_strings = start_blob + inner.stringLength();
const gids_offset = compress.uvarint(bytes[end_strings..]) catch |err| switch (err) {
error.Overflow => unreachable,
};
const end_blob = end_strings + gids_offset.bytes_read;
const nextStart = pad.roundUp(usize, alignment_bits, end_blob);
var next: ?[]const u8 = null;
if (nextStart < bytes.len)
next = bytes[nextStart..];
return Entry{
.user = PackedUser{
.inner = inner,
.bytes = bytes[start_blob..end_blob],
.additional_gids_offset = gids_offset.value,
},
.next = next,
};
}
pub const Iterator = struct {
section: ?[]const u8,
shell_reader: shellImport.ShellReader,
pub fn next(it: *Iterator) ?PackedUser {
if (it.section) |section| {
const entry = PackedUser.fromBytes(section);
it.section = entry.next;
return entry.user;
}
return null;
}
};
pub fn iterator(section: []const u8, shell_reader: shellImport.ShellReader) Iterator {
return Iterator{ .section = section, .shell_reader = shell_reader };
}
// packTo packs the User record and copies it to the given byte slice.
// The slice must have at least maxRecordSize() bytes available. The
// slice is passed as a pointer, so it can be mutated.
pub fn packTo(
arr: *ArrayList(u8),
user: User,
additional_gids_offset: u64,
idxFn: StringHashMap(u8),
) error{ InvalidRecord, OutOfMemory }!void {
std.debug.assert(arr.items.len & 7 == 0);
// function arguments are consts. We need to mutate the underlying
// slice, so passing it via pointer instead.
const home_len = try validate.downCast(u6, user.home.len - 1);
const name_len = try validate.downCast(u5, user.name.len - 1);
const shell_len = try validate.downCast(u8, user.shell.len - 1);
const gecos_len = try validate.downCast(u8, user.gecos.len);
try validate.utf8(user.home);
try validate.utf8(user.name);
try validate.utf8(user.shell);
try validate.utf8(user.gecos);
const inner = Inner{
.uid = user.uid,
.gid = user.gid,
.shell_here = idxFn.get(user.shell) == null,
.shell_len_or_idx = idxFn.get(user.shell) orelse shell_len,
.home_len = home_len,
.name_is_a_suffix = mem.endsWith(u8, user.home, user.name),
.name_len = name_len,
.gecos_len = gecos_len,
};
const innerBytes = mem.asBytes(&inner);
try arr.*.appendSlice(innerBytes[0..@sizeOf(Inner)]);
try arr.*.appendSlice(user.home);
if (!inner.name_is_a_suffix)
try arr.*.appendSlice(user.name);
try arr.*.appendSlice(user.gecos);
if (inner.shell_here)
try arr.*.appendSlice(user.shell);
try compress.appendUvarint(arr, additional_gids_offset);
}
pub fn uid(self: PackedUser) u32 {
return self.inner.uid;
}
pub fn gid(self: PackedUser) u32 {
return self.inner.gid;
}
pub fn additionalGidsOffset(self: PackedUser) u64 {
return self.additional_gids_offset;
}
pub fn home(self: PackedUser) []const u8 {
return self.bytes[0..self.inner.homeLen()];
}
pub fn name(self: PackedUser) []const u8 {
const name_pos = self.inner.nameStart();
const name_len = self.inner.nameLen();
return self.bytes[name_pos .. name_pos + name_len];
}
pub fn gecos(self: PackedUser) []const u8 {
const gecos_pos = self.inner.gecosStart();
const gecos_len = self.inner.gecosLen();
return self.bytes[gecos_pos .. gecos_pos + gecos_len];
}
pub fn shell(self: PackedUser, shell_reader: shellImport.ShellReader) []const u8 {
if (self.inner.shell_here) {
const shell_pos = self.inner.maybeShellStart();
const shell_len = self.inner.shellLen();
return self.bytes[shell_pos .. shell_pos + shell_len];
}
return shell_reader.get(self.inner.shell_len_or_idx);
}
const testing = std.testing;
test "PackedUser internal and external alignment" {
try testing.expectEqual(
@sizeOf(PackedUser.Inner) * 8,
@bitSizeOf(PackedUser.Inner),
);
}
fn testShellIndex(allocator: Allocator) StringHashMap(u8) {
var result = StringHashMap(u8).init(allocator);
result.put("/bin/bash", 0) catch unreachable;
result.put("/bin/zsh", 1) catch unreachable;
return result;
}
const test_shell_reader = shellImport.ShellReader{
.blob = "/bin/bash/bin/zsh",
.index = &[_]u16{ 0, 9, 17 },
};
test "construct PackedUser section" {
var buf = ArrayList(u8).init(testing.allocator);
defer buf.deinit();
const users = [_]User{ User{
.uid = 1000,
.gid = 1000,
.name = "vidmantas",
.gecos = "Vidmantas Kaminskas",
.home = "/home/vidmantas",
.shell = "/bin/bash",
}, User{
.uid = 1001,
.gid = 1001,
.name = "svc-foo",
.gecos = "Service Account",
.home = "/home/service1",
.shell = "/usr/bin/nologin",
}, User{
.uid = 0,
.gid = math.maxInt(u32),
.name = "Name" ** 8,
.gecos = "Gecos" ** 51,
.home = "Home" ** 16,
.shell = "She.LllL" ** 32,
}, User{
.uid = 1002,
.gid = 1002,
.name = "svc-bar",
.gecos = "",
.home = "/",
.shell = "/bin/zsh",
} };
var shellIndex = testShellIndex(testing.allocator);
const additional_gids = math.maxInt(u64);
defer shellIndex.deinit();
for (users) |user| {
try PackedUser.packTo(&buf, user, additional_gids, shellIndex);
try pad.arrayList(&buf, PackedUser.alignment_bits);
}
var i: u29 = 0;
var it1 = PackedUser.iterator(buf.items, test_shell_reader);
while (it1.next()) |user| : (i += 1) {
try testing.expectEqual(users[i].uid, user.uid());
try testing.expectEqual(users[i].gid, user.gid());
try testing.expectEqual(user.additionalGidsOffset(), additional_gids);
try testing.expectEqualStrings(users[i].name, user.name());
try testing.expectEqualStrings(users[i].gecos, user.gecos());
try testing.expectEqualStrings(users[i].home, user.home());
try testing.expectEqualStrings(users[i].shell, user.shell(test_shell_reader));
}
try testing.expectEqual(users.len, i);
}

67
lib/User.zig Normal file
View File

@ -0,0 +1,67 @@
const std = @import("std");
const mem = std.mem;
const Allocator = mem.Allocator;
const User = @This();
uid: u32,
gid: u32,
name: []const u8,
gecos: []const u8,
home: []const u8,
shell: []const u8,
// deep-clones a User record with a given Allocator.
pub fn clone(
self: *const User,
allocator: Allocator,
) error{OutOfMemory}!User {
const stringdata = try allocator.alloc(u8, self.strlen());
const gecos_start = self.name.len;
const home_start = gecos_start + self.gecos.len;
const shell_start = home_start + self.home.len;
mem.copy(u8, stringdata[0..self.name.len], self.name);
mem.copy(u8, stringdata[gecos_start..], self.gecos);
mem.copy(u8, stringdata[home_start..], self.home);
mem.copy(u8, stringdata[shell_start..], self.shell);
return User{
.uid = self.uid,
.gid = self.gid,
.name = stringdata[0..self.name.len],
.gecos = stringdata[gecos_start .. gecos_start + self.gecos.len],
.home = stringdata[home_start .. home_start + self.home.len],
.shell = stringdata[shell_start .. shell_start + self.shell.len],
};
}
fn strlen(self: *const User) usize {
return self.name.len +
self.gecos.len +
self.home.len +
self.shell.len;
}
pub fn deinit(self: *User, allocator: Allocator) void {
const slice = self.home.ptr[0..self.strlen()];
allocator.free(slice);
self.* = undefined;
}
const testing = std.testing;
test "User.clone" {
var allocator = testing.allocator;
const user = User{
.uid = 1000,
.gid = 1000,
.name = "vidmantas",
.gecos = "Vidmantas Kaminskas",
.home = "/home/vidmantas",
.shell = "/bin/bash",
};
var user2 = try user.clone(allocator);
defer user2.deinit(allocator);
try testing.expectEqualStrings(user.shell, "/bin/bash");
}

201
lib/group.zig
View File

@ -1,201 +0,0 @@
const std = @import("std");
const pad = @import("padding.zig");
const validate = @import("validate.zig");
const compress = @import("compress.zig");
const InvalidRecord = validate.InvalidRecord;
const mem = std.mem;
const Allocator = mem.Allocator;
const ArrayList = std.ArrayList;
const BufSet = std.BufSet;
pub const Group = struct {
gid: u32,
name: []const u8,
members: BufSet,
pub fn clone(self: *const Group, allocator: Allocator) Allocator.Error!Group {
var name = try allocator.dupe(u8, self.name);
return Group{
.gid = self.gid,
.name = name,
.members = try self.members.cloneWithAllocator(allocator),
};
}
pub fn deinit(self: *Group, allocator: Allocator) void {
allocator.free(self.name);
self.members.deinit();
self.* = undefined;
}
};
pub const GroupStored = struct {
gid: u32,
name: []const u8,
members_offset: u64,
};
pub const PackedGroup = struct {
pub const alignment_bits = 3;
const Inner = packed struct {
gid: u32,
padding: u3 = 0,
groupname_len: u5,
pub fn groupnameLen(self: *const Inner) usize {
return @as(usize, self.groupname_len) + 1;
}
};
inner: *const Inner,
groupdata: []const u8,
members_offset: u64,
pub const Entry = struct {
group: PackedGroup,
next: ?[]const u8,
};
pub fn fromBytes(bytes: []const u8) error{Overflow}!Entry {
const inner = mem.bytesAsValue(Inner, bytes[0..@sizeOf(Inner)]);
const start_blob = @sizeOf(Inner);
const end_strings = @sizeOf(Inner) + inner.groupnameLen();
const members_offset = try compress.uvarint(bytes[end_strings..]);
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{
.inner = inner,
.groupdata = bytes[start_blob..end_strings],
.members_offset = members_offset.value,
},
.next = next,
};
}
fn validateUtf8(s: []const u8) InvalidRecord!void {
if (!std.unicode.utf8ValidateSlice(s))
return error.InvalidRecord;
}
pub const Iterator = struct {
section: ?[]const u8,
pub fn next(it: *Iterator) error{Overflow}!?PackedGroup {
if (it.section) |section| {
const entry = try fromBytes(section);
it.section = entry.next;
return entry.group;
}
return null;
}
};
pub fn iterator(section: []const u8) Iterator {
return Iterator{ .section = section };
}
pub fn gid(self: *const PackedGroup) u32 {
return self.inner.gid;
}
pub fn membersOffset(self: *const PackedGroup) u64 {
return self.members_offset;
}
pub fn name(self: *const PackedGroup) []const u8 {
return self.groupdata;
}
pub fn packTo(
arr: *ArrayList(u8),
group: GroupStored,
) error{ InvalidRecord, OutOfMemory }!void {
std.debug.assert(arr.items.len & 7 == 0);
try validate.utf8(group.name);
const len = try validate.downCast(u5, group.name.len - 1);
const inner = Inner{ .gid = group.gid, .groupname_len = len };
try arr.*.appendSlice(mem.asBytes(&inner));
try arr.*.appendSlice(group.name);
try compress.appendUvarint(arr, group.members_offset);
}
};
const testing = std.testing;
// someMembers constructs a bufset from an allocator and a list of strings.
pub fn someMembers(
allocator: Allocator,
members: []const []const u8,
) Allocator.Error!BufSet {
var bufset = BufSet.init(allocator);
errdefer bufset.deinit();
for (members) |member|
try bufset.insert(member);
return bufset;
}
test "PackedGroup alignment" {
try testing.expectEqual(@sizeOf(PackedGroup) * 8, @bitSizeOf(PackedGroup));
}
test "construct PackedGroups" {
var buf = ArrayList(u8).init(testing.allocator);
defer buf.deinit();
const groups = [_]GroupStored{
GroupStored{
.gid = 1000,
.name = "sudo",
.members_offset = 1,
},
GroupStored{
.gid = std.math.maxInt(u32),
.name = "Name" ** 8, // 32
.members_offset = std.math.maxInt(u64),
},
};
for (groups) |group| {
try PackedGroup.packTo(&buf, group);
try pad.arrayList(&buf, PackedGroup.alignment_bits);
}
var i: u29 = 0;
var it = PackedGroup.iterator(buf.items);
while (try it.next()) |group| : (i += 1) {
try testing.expectEqual(groups[i].gid, group.gid());
try testing.expectEqualStrings(groups[i].name, group.name());
try testing.expectEqual(groups[i].members_offset, group.membersOffset());
}
try testing.expectEqual(groups.len, i);
}
test "Group.clone" {
var allocator = testing.allocator;
var arena = std.heap.ArenaAllocator.init(allocator);
defer arena.deinit();
var members = BufSet.init(allocator);
try members.insert("member1");
try members.insert("member2");
defer members.deinit();
var cloned = try members.cloneWithAllocator(arena.allocator());
cloned.remove("member1");
try cloned.insert("member4");
try testing.expect(members.contains("member1"));
try testing.expect(!members.contains("member4"));
try testing.expect(!cloned.contains("member1"));
try testing.expect(cloned.contains("member4"));
}

44
lib/header.zig
View File

@ -45,10 +45,10 @@ pub const Header = packed struct {
nblocks_groupmembers: u64,
nblocks_additional_gids: u64,
pub fn fromBytes(blob: []const u8) Invalid!Header {
pub fn fromBytes(blob: *const [@sizeOf(Header)]u8) Invalid!*const Header {
const self = mem.bytesAsValue(Header, blob);
if (!mem.eql(magic, blob[0..4]))
if (!mem.eql(u8, magic[0..4], blob[0..4]))
return error.InvalidMagic;
if (self.version != 0)
@ -75,27 +75,23 @@ test "bit header size is equal to @sizeOf(Header)" {
try testing.expectEqual(@sizeOf(Header) * 8, @bitSizeOf(Header));
}
test "header pack, unpack and validation" {
//const goodHeader = Header{};
test "header pack and unpack" {
const header1 = Header{
.nblocks_shell_blob = 0,
.num_shells = 0,
.num_groups = 0,
.num_users = 0,
.nblocks_bdz_gid = 0,
.nblocks_bdz_groupname = 0,
.nblocks_bdz_uid = 0,
.nblocks_bdz_username = 0,
.nblocks_groups = 0,
.nblocks_users = 0,
.nblocks_groupmembers = 0,
.nblocks_additional_gids = 1,
};
//const gotHeader = try Header.init(goodHeader.asArray());
//try testing.expectEqual(goodHeader, gotHeader);
//{
// var header = goodHeader;
// header.magic[0] = 0;
// try testing.expectError(error.InvalidMagic, Header.init(header.asArray()));
//}
//{
// var header = goodHeader;
// header.bom = 0x3412;
// try testing.expectError(error.InvalidBom, Header.init(header.asArray()));
//}
//{
// var header = goodHeader;
// header.offset_bdz_uid2user = 65;
// try testing.expectError(error.InvalidOffset, Header.init(header.asArray()));
//}
const bytes = mem.asBytes(&header1);
const header = try Header.fromBytes(bytes);
try testing.expectEqual(header1, header.*);
}

5
lib/test_all.zig
View File

@ -4,8 +4,9 @@ test "turbonss test suite" {
_ = @import("DB.zig");
_ = @import("Corpus.zig");
_ = @import("shell.zig");
_ = @import("user.zig");
_ = @import("group.zig");
_ = @import("User.zig");
_ = @import("PackedUser.zig");
_ = @import("Group.zig");
_ = @import("validate.zig");
_ = @import("padding.zig");
_ = @import("compress.zig");

353
lib/user.zig
View File

@ -1,353 +0,0 @@
const std = @import("std");
const pad = @import("padding.zig");
const validate = @import("validate.zig");
const compress = @import("compress.zig");
const shellImport = @import("shell.zig");
const InvalidRecord = validate.InvalidRecord;
const assert = std.debug.assert;
const mem = std.mem;
const math = std.math;
const Allocator = mem.Allocator;
const ArrayList = std.ArrayList;
const StringHashMap = std.StringHashMap;
// User is a convenient public struct for record construction and
// serialization.
pub const User = struct {
uid: u32,
gid: u32,
name: []const u8,
gecos: []const u8,
home: []const u8,
shell: []const u8,
// deep-clones a User record with a given Allocator.
pub fn clone(
self: *const User,
allocator: Allocator,
) Allocator.Error!User {
const stringdata = try allocator.alloc(u8, self.strlen());
const gecos_start = self.name.len;
const home_start = gecos_start + self.gecos.len;
const shell_start = home_start + self.home.len;
mem.copy(u8, stringdata[0..self.name.len], self.name);
mem.copy(u8, stringdata[gecos_start..], self.gecos);
mem.copy(u8, stringdata[home_start..], self.home);
mem.copy(u8, stringdata[shell_start..], self.shell);
return User{
.uid = self.uid,
.gid = self.gid,
.name = stringdata[0..self.name.len],
.gecos = stringdata[gecos_start .. gecos_start + self.gecos.len],
.home = stringdata[home_start .. home_start + self.home.len],
.shell = stringdata[shell_start .. shell_start + self.shell.len],
};
}
fn strlen(self: *const User) usize {
return self.name.len +
self.gecos.len +
self.home.len +
self.shell.len;
}
pub fn deinit(self: *User, allocator: Allocator) void {
const slice = self.home.ptr[0..self.strlen()];
allocator.free(slice);
self.* = undefined;
}
};
pub const PackedUser = struct {
const Self = @This();
pub const alignment_bits = 3;
const Inner = packed struct {
uid: u32,
gid: u32,
shell_len_or_idx: u8,
shell_here: bool,
name_is_a_suffix: bool,
home_len: u6,
name_len: u5,
gecos_len: u11,
fn homeLen(self: *const Inner) usize {
return @as(u32, self.home_len) + 1;
}
fn nameStart(self: *const Inner) usize {
const name_len = self.nameLen();
if (self.name_is_a_suffix) {
return self.homeLen() - name_len;
} else return self.homeLen();
}
fn nameLen(self: *const Inner) usize {
return @as(u32, self.name_len) + 1;
}
fn gecosStart(self: *const Inner) usize {
if (self.name_is_a_suffix) {
return self.homeLen();
} else return self.homeLen() + self.nameLen();
}
fn gecosLen(self: *const Inner) usize {
return self.gecos_len;
}
fn maybeShellStart(self: *const Inner) usize {
assert(self.shell_here);
return self.gecosStart() + self.gecosLen();
}
fn shellLen(self: *const Inner) usize {
return @as(u32, self.shell_len_or_idx) + 1;
}
// stringLength returns the length of the blob storing string values.
fn stringLength(self: *const Inner) usize {
var result: usize = self.homeLen() + self.gecosLen();
if (!self.name_is_a_suffix)
result += self.nameLen();
if (self.shell_here)
result += self.shellLen();
return result;
}
};
// PackedUser does not allocate; it re-interprets the "bytes" blob
// field. Both of those fields are pointers to "our representation" of
// that field.
inner: *const Inner,
bytes: []const u8,
additional_gids_offset: u64,
pub const Entry = struct {
user: Self,
next: ?[]const u8,
};
// TODO(motiejus) provide a way to return an entry without decoding the
// additional_gids_offset:
// - will not return the 'next' slice.
// - cannot throw an Overflow error.
pub fn fromBytes(bytes: []const u8) error{Overflow}!Entry {
const inner = mem.bytesAsValue(Inner, bytes[0..@sizeOf(Inner)]);
const start_blob = @sizeOf(Inner);
const end_strings = start_blob + inner.stringLength();
const gids_offset = try compress.uvarint(bytes[end_strings..]);
const end_blob = end_strings + gids_offset.bytes_read;
const nextStart = pad.roundUp(usize, alignment_bits, end_blob);
var next: ?[]const u8 = null;
if (nextStart < bytes.len)
next = bytes[nextStart..];
return Entry{
.user = Self{
.inner = inner,
.bytes = bytes[start_blob..end_blob],
.additional_gids_offset = gids_offset.value,
},
.next = next,
};
}
pub const Iterator = struct {
section: ?[]const u8,
shell_reader: shellImport.ShellReader,
pub fn next(it: *Iterator) error{Overflow}!?Self {
if (it.section) |section| {
const entry = try Self.fromBytes(section);
it.section = entry.next;
return entry.user;
}
return null;
}
};
pub fn iterator(section: []const u8, shell_reader: shellImport.ShellReader) Iterator {
return Iterator{ .section = section, .shell_reader = shell_reader };
}
// packTo packs the User record and copies it to the given byte slice.
// The slice must have at least maxRecordSize() bytes available. The
// slice is passed as a pointer, so it can be mutated.
pub fn packTo(
arr: *ArrayList(u8),
user: User,
additional_gids_offset: u64,
idxFn: StringHashMap(u8),
) error{ InvalidRecord, OutOfMemory }!void {
std.debug.assert(arr.items.len & 7 == 0);
// function arguments are consts. We need to mutate the underlying
// slice, so passing it via pointer instead.
const home_len = try validate.downCast(u6, user.home.len - 1);
const name_len = try validate.downCast(u5, user.name.len - 1);
const shell_len = try validate.downCast(u8, user.shell.len - 1);
const gecos_len = try validate.downCast(u8, user.gecos.len);
try validate.utf8(user.home);
try validate.utf8(user.name);
try validate.utf8(user.shell);
try validate.utf8(user.gecos);
const inner = Inner{
.uid = user.uid,
.gid = user.gid,
.shell_here = idxFn.get(user.shell) == null,
.shell_len_or_idx = idxFn.get(user.shell) orelse shell_len,
.home_len = home_len,
.name_is_a_suffix = mem.endsWith(u8, user.home, user.name),
.name_len = name_len,
.gecos_len = gecos_len,
};
const innerBytes = mem.asBytes(&inner);
try arr.*.appendSlice(innerBytes[0..@sizeOf(Inner)]);
try arr.*.appendSlice(user.home);
if (!inner.name_is_a_suffix)
try arr.*.appendSlice(user.name);
try arr.*.appendSlice(user.gecos);
if (inner.shell_here)
try arr.*.appendSlice(user.shell);
try compress.appendUvarint(arr, additional_gids_offset);
}
pub fn uid(self: Self) u32 {
return self.inner.uid;
}
pub fn gid(self: Self) u32 {
return self.inner.gid;
}
pub fn additionalGidsOffset(self: Self) u64 {
return self.additional_gids_offset;
}
pub fn home(self: Self) []const u8 {
return self.bytes[0..self.inner.homeLen()];
}
pub fn name(self: Self) []const u8 {
const name_pos = self.inner.nameStart();
const name_len = self.inner.nameLen();
return self.bytes[name_pos .. name_pos + name_len];
}
pub fn gecos(self: Self) []const u8 {
const gecos_pos = self.inner.gecosStart();
const gecos_len = self.inner.gecosLen();
return self.bytes[gecos_pos .. gecos_pos + gecos_len];
}
pub fn shell(self: Self, shell_reader: shellImport.ShellReader) []const u8 {
if (self.inner.shell_here) {
const shell_pos = self.inner.maybeShellStart();
const shell_len = self.inner.shellLen();
return self.bytes[shell_pos .. shell_pos + shell_len];
}
return shell_reader.get(self.inner.shell_len_or_idx);
}
};
const testing = std.testing;
test "PackedUser internal and external alignment" {
try testing.expectEqual(
@sizeOf(PackedUser.Inner) * 8,
@bitSizeOf(PackedUser.Inner),
);
}
fn testShellIndex(allocator: Allocator) StringHashMap(u8) {
var result = StringHashMap(u8).init(allocator);
result.put("/bin/bash", 0) catch unreachable;
result.put("/bin/zsh", 1) catch unreachable;
return result;
}
const test_shell_reader = shellImport.ShellReader{
.blob = "/bin/bash/bin/zsh",
.index = &[_]u16{ 0, 9, 17 },
};
test "construct PackedUser section" {
var buf = ArrayList(u8).init(testing.allocator);
defer buf.deinit();
const users = [_]User{ User{
.uid = 1000,
.gid = 1000,
.name = "vidmantas",
.gecos = "Vidmantas Kaminskas",
.home = "/home/vidmantas",
.shell = "/bin/bash",
}, User{
.uid = 1001,
.gid = 1001,
.name = "svc-foo",
.gecos = "Service Account",
.home = "/home/service1",
.shell = "/usr/bin/nologin",
}, User{
.uid = 0,
.gid = math.maxInt(u32),
.name = "Name" ** 8,
.gecos = "Gecos" ** 51,
.home = "Home" ** 16,
.shell = "She.LllL" ** 32,
}, User{
.uid = 1002,
.gid = 1002,
.name = "svc-bar",
.gecos = "",
.home = "/",
.shell = "/bin/zsh",
} };
var shellIndex = testShellIndex(testing.allocator);
const additional_gids = math.maxInt(u64);
defer shellIndex.deinit();
for (users) |user| {
try PackedUser.packTo(&buf, user, additional_gids, shellIndex);
try pad.arrayList(&buf, PackedUser.alignment_bits);
}
var i: u29 = 0;
var it1 = PackedUser.iterator(buf.items, test_shell_reader);
while (try it1.next()) |user| : (i += 1) {
try testing.expectEqual(users[i].uid, user.uid());
try testing.expectEqual(users[i].gid, user.gid());
try testing.expectEqual(user.additionalGidsOffset(), additional_gids);
try testing.expectEqualStrings(users[i].name, user.name());
try testing.expectEqualStrings(users[i].gecos, user.gecos());
try testing.expectEqualStrings(users[i].home, user.home());
try testing.expectEqualStrings(users[i].shell, user.shell(test_shell_reader));
}
try testing.expectEqual(users.len, i);
}
test "User.clone" {
var allocator = testing.allocator;
const user = User{
.uid = 1000,
.gid = 1000,
.name = "vidmantas",
.gecos = "Vidmantas Kaminskas",
.home = "/home/vidmantas",
.shell = "/bin/bash",
};
var user2 = try user.clone(allocator);
defer user2.deinit(allocator);
try testing.expectEqualStrings(user.shell, "/bin/bash");
}