AdGuardHome/internal/filtering/safesearch.go

package filtering

import (
	"github.com/AdguardTeam/urlfilter/rules"
	"github.com/miekg/dns"
)

// SafeSearch interface describes a service for search engines hosts rewrites.
type SafeSearch interface {
	// SearchHost returns a replacement address for the search engine host.
	SearchHost(host string, qtype uint16) (res *rules.DNSRewrite)

	// CheckHost checks host with safe search engine.
	CheckHost(host string, qtype uint16) (res Result, err error)
}

// SafeSearchConfig is a struct with safe search related settings.
type SafeSearchConfig struct {
	// CustomResolver is the resolver used by safe search.
	CustomResolver Resolver `yaml:"-" json:"-"`

	// Enabled indicates if safe search is enabled entirely.
	Enabled bool `yaml:"enabled" json:"enabled"`

	// Services flags.  Each flag indicates if the corresponding service is
	// enabled or disabled.

	Bing       bool `yaml:"bing" json:"bing"`
	DuckDuckGo bool `yaml:"duckduckgo" json:"duckduckgo"`
	Google     bool `yaml:"google" json:"google"`
	Pixabay    bool `yaml:"pixabay" json:"pixabay"`
	Yandex     bool `yaml:"yandex" json:"yandex"`
	YouTube    bool `yaml:"youtube" json:"youtube"`
}

// checkSafeSearch checks host with safe search engine.  Matches
// [hostChecker.check].
func (d *DNSFilter) checkSafeSearch(
	host string,
	_ uint16,
	setts *Settings,
) (res Result, err error) {
	if !setts.ProtectionEnabled || !setts.SafeSearchEnabled {
		return Result{}, nil
	}

	if d.safeSearch == nil {
		return Result{}, nil
	}

	clientSafeSearch := setts.ClientSafeSearch
	if clientSafeSearch != nil {
		return clientSafeSearch.CheckHost(host, dns.TypeA)
	}

	return d.safeSearch.CheckHost(host, dns.TypeA)
}