Files
go-away/lib/conditions.go
2025-04-12 02:13:05 +02:00

121 lines
2.8 KiB
Go

package lib
import (
"context"
"fmt"
"github.com/google/cel-go/cel"
"github.com/google/cel-go/common/types"
"github.com/google/cel-go/common/types/ref"
"log/slog"
"net"
"time"
)
func (state *State) initConditions() (err error) {
state.RulesEnv, err = cel.NewEnv(
cel.DefaultUTCTimeZone(true),
cel.Variable("remoteAddress", cel.BytesType),
cel.Variable("host", cel.StringType),
cel.Variable("method", cel.StringType),
cel.Variable("userAgent", cel.StringType),
cel.Variable("path", cel.StringType),
cel.Variable("query", cel.MapType(cel.StringType, cel.StringType)),
cel.Variable("fpJA3N", cel.StringType),
cel.Variable("fpJA4", cel.StringType),
// http.Header
cel.Variable("headers", cel.MapType(cel.StringType, cel.StringType)),
//TODO: dynamic type?
cel.Function("inDNSBL",
cel.Overload("inDNSBL_ip",
[]*cel.Type{cel.AnyType},
cel.BoolType,
cel.UnaryBinding(func(val ref.Val) ref.Val {
if state.Settings.DNSBL == nil {
return types.Bool(false)
}
var ip net.IP
switch v := val.Value().(type) {
case []byte:
ip = v
case net.IP:
ip = v
case string:
ip = net.ParseIP(v)
}
if ip == nil {
panic(fmt.Errorf("invalid ip %v", val.Value()))
}
var key [net.IPv6len]byte
copy(key[:], ip.To16())
result, ok := state.DecayMap.Get(key)
if ok {
return types.Bool(result.Bad())
}
ctx, cancel := context.WithTimeout(context.Background(), time.Second)
defer cancel()
result, err := state.Settings.DNSBL.Lookup(ctx, ip)
if err != nil {
slog.Debug("dnsbl lookup failed", "address", ip.String(), "result", result, "err", err)
} else {
slog.Debug("dnsbl lookup", "address", ip.String(), "result", result)
}
//TODO: configure decay
state.DecayMap.Set(key, result, time.Hour)
return types.Bool(result.Bad())
}),
),
),
cel.Function("inNetwork",
cel.Overload("inNetwork_string_ip",
[]*cel.Type{cel.StringType, cel.AnyType},
cel.BoolType,
cel.BinaryBinding(func(lhs ref.Val, rhs ref.Val) ref.Val {
var ip net.IP
switch v := rhs.Value().(type) {
case []byte:
ip = v
case net.IP:
ip = v
case string:
ip = net.ParseIP(v)
}
if ip == nil {
panic(fmt.Errorf("invalid ip %v", rhs.Value()))
}
val, ok := lhs.Value().(string)
if !ok {
panic(fmt.Errorf("invalid value %v", lhs.Value()))
}
network, ok := state.Networks[val]
if !ok {
_, ipNet, err := net.ParseCIDR(val)
if err != nil {
panic("network not found")
}
return types.Bool(ipNet.Contains(ip))
} else {
ok, err := network.Contains(ip)
if err != nil {
panic(err)
}
return types.Bool(ok)
}
}),
),
),
)
if err != nil {
return err
}
return nil
}