Files
anubis-mirror/lib/checker/remoteaddress/remoteaddress.go
2025-07-01 23:58:42 +00:00

107 lines
2.3 KiB
Go

package remoteaddress
import (
"encoding/json"
"errors"
"fmt"
"net/http"
"net/netip"
"github.com/TecharoHQ/anubis/internal"
"github.com/TecharoHQ/anubis/lib/checker"
"github.com/TecharoHQ/anubis/lib/policy"
"github.com/TecharoHQ/anubis/lib/policy/config"
"github.com/gaissmai/bart"
)
var (
ErrNoRemoteAddresses = errors.New("remoteaddress: no remote addresses defined")
)
func init() {
checker.Register("remote_address", Factory{})
}
type Factory struct{}
func (Factory) ValidateConfig(inp json.RawMessage) error {
var fc fileConfig
if err := json.Unmarshal([]byte(inp), &fc); err != nil {
return fmt.Errorf("%w: %w", config.ErrUnparseableConfig, err)
}
if err := fc.Valid(); err != nil {
return err
}
return nil
}
func (Factory) Create(inp json.RawMessage) (checker.Impl, error) {
c := struct {
RemoteAddr []netip.Prefix `json:"remote_addresses,omitempty" yaml:"remote_addresses,omitempty"`
}{}
if err := json.Unmarshal([]byte(inp), &c); err != nil {
return nil, fmt.Errorf("%w: %w", config.ErrUnparseableConfig, err)
}
table := new(bart.Lite)
for _, cidr := range c.RemoteAddr {
table.Insert(cidr)
}
return &Impl{
prefixTable: table,
hash: internal.FastHash(string(inp)),
}, nil
}
type fileConfig struct {
RemoteAddr []string `json:"remote_addresses,omitempty" yaml:"remote_addresses,omitempty"`
}
func (fc fileConfig) Valid() error {
var errs []error
if len(fc.RemoteAddr) == 0 {
errs = append(errs, ErrNoRemoteAddresses)
}
for _, cidr := range fc.RemoteAddr {
if _, err := netip.ParsePrefix(cidr); err != nil {
errs = append(errs, fmt.Errorf("%w: cidr %q is invalid: %w", config.ErrInvalidCIDR, cidr, err))
}
}
if len(errs) != 0 {
return fmt.Errorf("%w: %w", policy.ErrMisconfiguration, errors.Join(errs...))
}
return nil
}
type Impl struct {
prefixTable *bart.Lite
hash string
}
func (rac *Impl) Check(r *http.Request) (bool, error) {
host := r.Header.Get("X-Real-Ip")
if host == "" {
return false, fmt.Errorf("%w: header X-Real-Ip is not set", policy.ErrMisconfiguration)
}
addr, err := netip.ParseAddr(host)
if err != nil {
return false, fmt.Errorf("%w: %s is not an IP address: %w", policy.ErrMisconfiguration, host, err)
}
return rac.prefixTable.Contains(addr), nil
}
func (rac *Impl) Hash() string {
return rac.hash
}