@@ -10,6 +10,12 @@ const BotDetection = @This();
pub fn init(r: *const Request) BotDetection {
if (r.user_agent == null) return .{ .bot = true, .malicious = true };
const ua = r.user_agent.?;
var score: f64 = 0.0;
inline for (rules) |rule| {
rule(ua, r, &score) catch @panic("not implemented");
}
switch (ua.resolved) {
.bot => {
return .{
@@ -21,14 +27,14 @@ pub fn init(r: *const Request) BotDetection {
switch (browser.name) {
.chrome => {
return .{
.bot = true,
.malicious = false,
.bot = score <= 0.5,
.malicious = score <= 0.5,
};
},
else => {
return .{
.bot = true,
.malicious = false,
.bot = score <= 0.5,
.malicious = score <= 0.5,
};
},
}
@@ -49,21 +55,35 @@ pub fn init(r: *const Request) BotDetection {
comptime unreachable;
}
const RuleError = error{
Generic,
};
const RuleFn = fn (UA, *const Request, *f64) RuleError!void;
const rules = [_]RuleFn{
Browsers.browserAge,
};
pub const Browsers = struct {
const Date = i64;
const VerDate = struct { u16, Date };
const browser_count = @typeInfo(UA.Browser.Name).@"enum".fields.len;
pub const Versions: [browser_count][]const Date = .{
&Chrome.Version.Dates,
&.{},
&.{},
&.{},
&.{},
&.{},
&.{},
&.{},
&.{},
pub const Versions: [browser_count][]const Date = brk: {
var v: [browser_count][]const Date = undefined;
v[@intFromEnum(UA.Browser.Name.brave)] = &.{};
v[@intFromEnum(UA.Browser.Name.chrome)] = &Chrome.Version.Dates;
v[@intFromEnum(UA.Browser.Name.edge)] = &.{};
v[@intFromEnum(UA.Browser.Name.firefox)] = &.{};
v[@intFromEnum(UA.Browser.Name.hastur)] = &.{};
v[@intFromEnum(UA.Browser.Name.ladybird)] = &.{};
v[@intFromEnum(UA.Browser.Name.opera)] = &.{};
v[@intFromEnum(UA.Browser.Name.safari)] = &.{};
v[@intFromEnum(UA.Browser.Name.unknown)] = &.{};
break :brk v;
};
pub const Chrome = struct {
pub const Version = enum(u16) {
_,
@@ -116,6 +136,47 @@ pub const Browsers = struct {
};
};
};
pub fn browserAge(ua: UA, _: *const Request, score: *f64) !void {
if (ua.resolved != .browser) return;
const dates = Versions[@intFromEnum(ua.resolved.browser.name)];
if (ua.resolved.browser.version >= dates.len) return; // TODO should this be an error?
const delta: i64 = std.time.timestamp() - dates[ua.resolved.browser.version];
const DAY: i64 = 86400;
const YEAR: i64 = 86400 * 365;
// These are all just made up based on feeling, TODO real data analysis
switch (delta) {
std.math.minInt(i64)...0 => {},
1...DAY * 45 => {},
DAY * 45 + 1...DAY * 120 => score.* = score.* + 0.1,
DAY * 120 + 1...YEAR => score.* = score.* + 0.3,
YEAR + 1...YEAR * 3 => score.* = score.* + 0.4,
YEAR * 3 + 1...std.math.maxInt(i64) => score.* = 1.0,
}
}
test browserAge {
var score: f64 = 0.0;
try browserAge(.{ .string = "", .resolved = .{
.browser = .{ .name = .chrome, .version = 0 },
} }, undefined, &score);
try std.testing.expectEqual(score, 1.0);
score = 0;
try browserAge(.{ .string = "", .resolved = .{
.browser = .{
.name = .chrome,
.version = Browsers.Chrome.Version.Dates[Browsers.Chrome.Version.Dates.len - 1],
},
} }, undefined, &score);
try std.testing.expectEqual(score, 0.0);
score = 0.0;
try browserAge(.{ .string = "", .resolved = .{
.browser = .{ .name = .unknown, .version = 0 },
} }, undefined, &score);
try std.testing.expectEqual(score, 0.0);
}
};
test Browsers {