╭─────────────╮ │scroll to top│ ╰─────────────╯ ╭ web.zig ──────────────────────────────────────────────────────╮ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ ╰───────────────────────────────────────────────────────────────╯
╭────╮ ╭ clone ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ╮ │http│ ssh │ │ ╰────╯ ╰ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ╯
2645 try output.appendSlice(allocator, try std.fmt.bufPrint(&pos_buf, " style=\"opacity:0;left:{d}ch;top:{d}em;width:{d}ch;height:{d}em\">", .{ r.x, r.y, r.size.width, r.size.height })); 2646 } else if (std.mem.startsWith(u8, custom, ui.file_input_prefix)) { 2647 try output.appendSlice(allocator, "<input type=\"file\" data-preserve-value data-action=\""); 2648 try appendEscapedHtml(allocator, output, custom[ui.file_input_prefix.len..]); 2649 var id_buf: [128]u8 = undefined; 2650 try output.appendSlice(allocator, try std.fmt.bufPrint(&id_buf, "\" data-key=\"control:{d}\" data-focus-id=\"{d}\" style=\"opacity:0;left:{d}ch;top:{d}em;width:{d}ch;height:{d}em\">", .{ id, id, r.x, r.y, r.size.width, r.size.height })); 2651 } 2652 }, 2653 else => {}, 2654 } 2655 } 2656 } 2657 2658 // emit hidden form owners beside the rendered panels. their controls point 2659 // back here with the standard HTML `form` attribute. 2660 fn renderForms(allocator: std.mem.Allocator, output: *std.ArrayList(u8), root_focus: *Focus) !void { 2661 // the focus child map preserves insertion order, which matches the order 2662 // widgets were added in code 2663 var iter = root_focus.children.iterator(); 2664 while (iter.next()) |entry| { 2665 const child = entry.value_ptr.*; 2666 const action_url = formAction(child.focus) orelse continue; 2667 2668 try output.appendSlice(allocator, "<form hidden data-key=\"form:"); 2669 var id_buf: [96]u8 = undefined; 2670 try output.appendSlice(allocator, try std.fmt.bufPrint(&id_buf, "{d}\" id=\"" ++ form_id_prefix ++ "{d}\" action=\"", .{ entry.key_ptr.*, entry.key_ptr.* })); 2671 try appendEscapedHtml(allocator, output, action_url); 2672 try output.appendSlice(allocator, "\" method=\"post\"></form>"); 2673 } 2674 } 2675 2676 // the 16 ansi colors as the browser shows them (xterm's defaults) 2677 const ansi_palette = [16]Grid.Color.Rgb{ 2678 .{ .r = 0x00, .g = 0x00, .b = 0x00 }, .{ .r = 0xcd, .g = 0x00, .b = 0x00 }, .{ .r = 0x00, .g = 0xcd, .b = 0x00 }, .{ .r = 0xcd, .g = 0xcd, .b = 0x00 }, 2679 .{ .r = 0x00, .g = 0x00, .b = 0xee }, .{ .r = 0xcd, .g = 0x00, .b = 0xcd }, .{ .r = 0x00, .g = 0xcd, .b = 0xcd }, .{ .r = 0xe5, .g = 0xe5, .b = 0xe5 }, 2680 .{ .r = 0x7f, .g = 0x7f, .b = 0x7f }, .{ .r = 0xff, .g = 0x00, .b = 0x00 }, .{ .r = 0x00, .g = 0xff, .b = 0x00 }, .{ .r = 0xff, .g = 0xff, .b = 0x00 }, 2681 .{ .r = 0x5c, .g = 0x5c, .b = 0xff }, .{ .r = 0xff, .g = 0x00, .b = 0xff }, .{ .r = 0x00, .g = 0xff, .b = 0xff }, .{ .r = 0xff, .g = 0xff, .b = 0xff }, 2682 }; 2683 2684 // resolve any color to rgb: palette colors through the ansi table and the 2685 // xterm 256-color layout (16 ansi, a 6x6x6 cube, then 24 grays) 2686 fn colorRgb(color: Grid.Color) Grid.Color.Rgb { 2687 return switch (color) { 2688 .rgb => |c| c, 2689 .ansi => |a| ansi_palette[@backingInt(a)], 2690 .indexed => |n| if (n < 16) 2691 ansi_palette[n] 2692 else if (n < 232) blk: { 2693 const levels = [6]u8{ 0, 0x5f, 0x87, 0xaf, 0xd7, 0xff }; 2694 const i = n - 16; 2695 break :blk .{ .r = levels[i / 36], .g = levels[(i / 6) % 6], .b = levels[i % 6] }; 2696 } else blk: { 2697 const v: u8 = 8 + (n - 232) * 10; 2698 break :blk .{ .r = v, .g = v, .b = v }; 2699 }, 2700 }; 2701 } 2702 2703 // builds an HTML ` style="color:…;background-color:…"` attribute from a 2704 // cell's style into `buf`, omitting whichever color is unset. an inverted 2705 // cell swaps the two, falling back to the page's --fg/--bg variables for 2706 // whichever side is unset. text attributes follow the colors. returns an 2707 // empty slice when nothing is set. 2708 fn styleAttr(buf: []u8, style: Grid.Style) []const u8 { 2709 if (style.eql(.{})) return buf[0..0]; 2710 const prefix = " style=\""; 2711 @memcpy(buf[0..prefix.len], prefix); 2712 var i: usize = prefix.len; 2713 const inverted = style.inverted; 2714 i = cssColor(buf, i, "color", if (inverted) style.bg else style.fg, if (inverted) "var(--bg)" else null) orelse return buf[0..0]; 2715 i = cssColor(buf, i, "background-color", if (inverted) style.fg else style.bg, if (inverted) "var(--fg)" else null) orelse return buf[0..0]; 2716 const decoration: []const u8 = if (style.underline and style.strikethrough) 2717 "text-decoration:underline line-through;" 2718 else if (style.underline) 2719 "text-decoration:underline;" 2720 else if (style.strikethrough) 2721 "text-decoration:line-through;" 2722 else 2723 ""; 2724 const attributes = std.fmt.bufPrint(buf[i..], "{s}{s}{s}{s}", .{ 2725 if (style.bold) "font-weight:bold;" else "", 2726 if (style.italic) "font-style:italic;" else "", 2727 decoration, 2728 if (style.dim) "opacity:.6;" else "", 2729 }) catch return buf[0..0]; 2730 i += attributes.len; 2731 if (i >= buf.len) return buf[0..0]; 2732 buf[i] = '"'; 2733 return buf[0 .. i + 1]; 2734 } 2735 2736 // append `prop:value;` at buf[i..] for the color, or for the fallback when 2737 // the color is unset (nothing when both are). returns the new end, or null 2738 // when it doesn't fit. 2739 fn cssColor(buf: []u8, i: usize, prop: []const u8, color: ?Grid.Color, fallback: ?[]const u8) ?usize { 2740 const s = if (color) |c| blk: { 2741 const v = colorRgb(c); 2742 break :blk std.fmt.bufPrint(buf[i..], "{s}:#{x:0>2}{x:0>2}{x:0>2};", .{ prop, v.r, v.g, v.b }) catch return null; 2743 } else if (fallback) |f| 2744 std.fmt.bufPrint(buf[i..], "{s}:{s};", .{ prop, f }) catch return null 2745 else 2746 return i; 2747 return i + s.len; 2748 } 2749 2750 // a cell's link as an href, when it's a page path or a web or mail url 2751 fn webLink(link: ?[]const u8) ?[]const u8 { 2752 const url = link orelse return null; 2753 // a page path, not a protocol-relative url 2754 if (url.len > 1 and url[0] == '/' and url[1] != '/') return url; 2755 for ([_][]const u8{ "http://", "https://", "mailto:" }) |scheme| { 2756 if (std.ascii.startsWithIgnoreCase(url, scheme)) return url; 2757 } 2758 return null; 2759 } 2760 2761 fn sameLink(a: ?[]const u8, b: ?[]const u8) bool { 2762 if (a) |x| return if (b) |y| std.mem.eql(u8, x, y) else false; 2763 return b == null; 2764 } 2765 2766 fn appendEscapedHtml(allocator: std.mem.Allocator, out: *std.ArrayList(u8), input: []const u8) !void { 2767 for (input) |ch| { 2768 switch (ch) { 2769 '&' => try out.appendSlice(allocator, "&amp;"), 2770 '<' => try out.appendSlice(allocator, "&lt;"), 2771 '>' => try out.appendSlice(allocator, "&gt;"), 2772 '"' => try out.appendSlice(allocator, "&quot;"), 2773 '\'' => try out.appendSlice(allocator, "&#39;"), 2774 else => try out.append(allocator, ch), 2775 } 2776 } 2777 } 2778 2779 // --- helpers -------------------------------------------------------------- 2780 2781 fn getCookieValue(request: *std.http.Server.Request, name: []const u8) ?[]const u8 { 2782 var iter = request.iterateHeaders(); 2783 while (iter.next()) |header| { 2784 if (!std.ascii.eqlIgnoreCase(header.name, "cookie")) continue; 2785 var pairs = std.mem.splitScalar(u8, header.value, ';'); 2786 while (pairs.next()) |pair| { 2787 const trimmed = std.mem.trim(u8, pair, " \t"); 2788 const eq = std.mem.indexOfScalar(u8, trimmed, '=') orelse continue; 2789 if (std.mem.eql(u8, trimmed[0..eq], name)) { 2790 return trimmed[eq + 1 ..]; 2791 } 2792 } 2793 } 2794 return null; 2795 } 2796 2797 fn parseFormField(allocator: std.mem.Allocator, body: []const u8, key: []const u8) !?[]u8 { 2798 var iter = std.mem.splitScalar(u8, body, '&'); 2799 while (iter.next()) |pair| { 2800 const eq = std.mem.indexOfScalar(u8, pair, '=') orelse continue; 2801 if (std.mem.eql(u8, pair[0..eq], key)) { 2802 return try decodeFormValue(allocator, pair[eq + 1 ..]); 2803 } 2804 } 2805 return null; 2806 } 2807 2808 fn readFormBody(request: *std.http.Server.Request, allocator: std.mem.Allocator) ![]u8 { 2809 var buffer: [256]u8 = undefined; 2810 return request.readerExpectNone(&buffer).allocRemaining(allocator, .limited(65536)); 2811 } 2812 2813 fn decodeFormValue(allocator: std.mem.Allocator, encoded: []const u8) ![]u8 { 2814 var out: std.ArrayList(u8) = .empty; 2815 errdefer out.deinit(allocator); 2816 var i: usize = 0; 2817 while (i < encoded.len) : (i += 1) { 2818 switch (encoded[i]) { 2819 '+' => try out.append(allocator, ' '), 2820 '%' => { 2821 if (i + 2 >= encoded.len) return error.InvalidPercentEncoding; 2822 const hi = std.fmt.charToDigit(encoded[i + 1], 16) catch return error.InvalidPercentEncoding; 2823 const lo = std.fmt.charToDigit(encoded[i + 2], 16) catch return error.InvalidPercentEncoding; 2824 try out.append(allocator, hi * 16 + lo); 2825 i += 2; 2826 }, 2827 else => try out.append(allocator, encoded[i]), 2828 } 2829 } 2830 return try out.toOwnedSlice(allocator); 2831 } 2832 2833 // disk-backed web session store. each login mints a random, opaque token 2834 // (not the user's id) that is stored as a file named by the token hex, whose 2835 // contents are the raw user_id bytes. authenticating a request is a lookup of 2836 // the cookie's token; logout deletes the file, revoking the session. there is 2837 // deliberately no expiry — a session lives until logout. form failures use 2838 // files in the flash subdirectory that the redirected GET consumes. the 2839 // directory is cleared whenever the server starts. 2840 pub const SessionStore = struct { 2841 io: std.Io, 2842 dir: std.Io.Dir, 2843 flash_dir: std.Io.Dir, 2844 auto_login: ?[token_hex_len]u8, 2845 2846 pub const token_hex_len = evt.event_id_size * 2; 2847 2848 pub fn init(io: std.Io, data_dir: std.Io.Dir) !SessionStore { 2849 try data_dir.createDirPath(io, "sessions"); 2850 const dir = try data_dir.openDir(io, "sessions", .{}); 2851 errdefer dir.close(io); 2852 try dir.deleteTree(io, "flash"); 2853 try dir.createDirPath(io, "flash"); 2854 const flash_dir = try dir.openDir(io, "flash", .{}); 2855 errdefer flash_dir.close(io); 2856 const auto_login = blk: { 2857 const file = dir.openFile(io, auto_login_name, .{ .mode = .read_only }) catch break :blk null; 2858 defer file.close(io); 2859 var token: [token_hex_len]u8 = undefined; 2860 var storage: [token_hex_len]u8 = undefined; 2861 var reader = file.reader(io, &storage); 2862 reader.interface.readSliceAll(&token) catch break :blk null; 2863 break :blk token; 2864 }; 2865 return .{ .io = io, .dir = dir, .flash_dir = flash_dir, .auto_login = auto_login }; 2866 } 2867 2868 pub fn deinit(self: SessionStore) void { 2869 self.flash_dir.close(self.io); 2870 self.dir.close(self.io); 2871 } 2872 2873 // mint a new session for user_id, returning the token hex to set as the 2874 // cookie value. 2875 pub fn create(self: SessionStore, user_id: *const [evt.event_id_size]u8) ![token_hex_len]u8 { 2876 var token: [evt.event_id_size]u8 = undefined; 2877 self.io.random(&token); 2878 const token_hex = std.fmt.bytesToHex(token, .lower); 2879 const file = try self.dir.createFile(self.io, &token_hex, .{}); 2880 defer file.close(self.io); 2881 try file.writeStreamingAll(self.io, user_id); 2882 return token_hex; 2883 } 2884 2885 fn createFlash(self: SessionStore, allocator: std.mem.Allocator, value: ui.Session.FormFeedback) ![token_hex_len]u8 { 2886 var token: [evt.event_id_size]u8 = undefined; 2887 self.io.random(&token); 2888 const token_hex = std.fmt.bytesToHex(token, .lower); 2889 const file = try self.flash_dir.createFile(self.io, &token_hex, .{}); 2890 errdefer self.flash_dir.deleteFile(self.io, &token_hex) catch {}; 2891 defer file.close(self.io); 2892 2893 var json: std.Io.Writer.Allocating = .init(allocator); 2894 defer json.deinit(); 2895 try std.json.Stringify.value(value, .{}, &json.writer); 2896 try file.writeStreamingAll(self.io, json.written()); 2897 return token_hex; 2898 } 2899 2900 fn takeFlash(self: SessionStore, allocator: std.mem.Allocator, token_hex: []const u8) ?ui.Session.FormFeedback { 2901 if (!isToken(token_hex)) return null; 2902 const file = self.flash_dir.openFile(self.io, token_hex, .{ .mode = .read_only }) catch return null; 2903 defer self.flash_dir.deleteFile(self.io, token_hex) catch {}; 2904 defer file.close(self.io); 2905 2906 var storage: [4096]u8 = undefined; 2907 var reader = file.reader(self.io, &storage); 2908 const bytes = reader.interface.allocRemaining(allocator, .limited(512 * 1024)) catch return null; 2909 return std.json.parseFromSliceLeaky(ui.Session.FormFeedback, allocator, bytes, .{}) catch null; 2910 } 2911 2912 // resolve a cookie's token to its user_id. returns false (logged out) for a 2913 // missing, malformed, or unknown token. 2914 pub fn lookup(self: SessionStore, token_hex: []const u8, out: *[evt.event_id_size]u8) bool { 2915 if (!isToken(token_hex)) return false; 2916 const file = self.dir.openFile(self.io, token_hex, .{ .mode = .read_only }) catch return false; 2917 defer file.close(self.io); 2918 var storage: [evt.event_id_size]u8 = undefined; 2919 var file_reader = file.reader(self.io, &storage); 2920 file_reader.interface.readSliceAll(out) catch return false; 2921 return true; 2922 } 2923 2924 // revoke a session. a no-op for a missing or malformed token. 2925 pub fn remove(self: SessionStore, token_hex: []const u8) void { 2926 if (!isToken(token_hex)) return; 2927 self.dir.deleteFile(self.io, token_hex) catch {}; 2928 } 2929 2930 // leave `token_hex`'s session for visitors arriving without one. only the 2931 // `try` fixture writes one. the name can't collide with a session token. 2932 pub fn offerAutoLogin(self: SessionStore, token_hex: *const [token_hex_len]u8) !void { 2933 const file = try self.dir.createFile(self.io, auto_login_name, .{}); 2934 defer file.close(self.io); 2935 try file.writeStreamingAll(self.io, token_hex); 2936 } 2937 2938 pub fn autoLogin(self: SessionStore, out: *[token_hex_len]u8) bool { 2939 out.* = self.auto_login orelse return false; 2940 return true; 2941 } 2942 2943 const auto_login_name = "auto-login"; 2944 2945 // a token is exactly token_hex_len hex chars. validating before using the 2946 // value as a path keeps attacker-supplied cookies from escaping the 2947 // sessions dir (e.g. via "/" or ".." bytes). 2948 fn isToken(token_hex: []const u8) bool { 2949 if (token_hex.len != token_hex_len) return false; 2950 for (token_hex) |c| if (!std.ascii.isHex(c)) return false; 2951 return true; 2952 } 2953 }; 2954