doggo/cmd/resolver.go

85 lines
2.5 KiB
Go

package main
import (
"time"
"github.com/mr-karan/doggo/pkg/resolvers"
)
const (
//DefaultResolvConfPath specifies path to default resolv config file on UNIX.
DefaultResolvConfPath = "/etc/resolv.conf"
// DefaultTLSPort specifies the default port for a DNS server connecting over TCP over TLS
DefaultTLSPort = "853"
// DefaultUDPPort specifies the default port for a DNS server connecting over UDP
DefaultUDPPort = "53"
// DefaultTCPPort specifies the default port for a DNS server connecting over TCP
DefaultTCPPort = "53"
UDPResolver = "udp"
DOHResolver = "doh"
TCPResolver = "tcp"
DOTResolver = "dot"
SystemResolver = "system"
)
// loadResolvers loads differently configured
// resolvers based on a list of nameserver.
func (hub *Hub) loadResolvers() error {
// for each nameserver, initialise the correct resolver
for _, ns := range hub.Nameservers {
if ns.Type == DOHResolver {
hub.Logger.Debug("initiating DOH resolver")
rslvr, err := resolvers.NewDOHResolver(ns.Address, resolvers.DOHResolverOpts{
Timeout: hub.QueryFlags.Timeout * time.Second,
})
if err != nil {
return err
}
hub.Resolver = append(hub.Resolver, rslvr)
}
if ns.Type == DOTResolver {
hub.Logger.Debug("initiating DOT resolver")
rslvr, err := resolvers.NewClassicResolver(ns.Address, resolvers.ClassicResolverOpts{
IPv4Only: hub.QueryFlags.UseIPv4,
IPv6Only: hub.QueryFlags.UseIPv6,
Timeout: hub.QueryFlags.Timeout * time.Second,
UseTLS: true,
UseTCP: true,
})
if err != nil {
return err
}
hub.Resolver = append(hub.Resolver, rslvr)
}
if ns.Type == TCPResolver {
hub.Logger.Debug("initiating TCP resolver")
rslvr, err := resolvers.NewClassicResolver(ns.Address, resolvers.ClassicResolverOpts{
IPv4Only: hub.QueryFlags.UseIPv4,
IPv6Only: hub.QueryFlags.UseIPv6,
Timeout: hub.QueryFlags.Timeout * time.Second,
UseTLS: false,
UseTCP: true,
})
if err != nil {
return err
}
hub.Resolver = append(hub.Resolver, rslvr)
}
if ns.Type == UDPResolver || ns.Type == SystemResolver {
hub.Logger.Debug("initiating UDP resolver")
rslvr, err := resolvers.NewClassicResolver(ns.Address, resolvers.ClassicResolverOpts{
IPv4Only: hub.QueryFlags.UseIPv4,
IPv6Only: hub.QueryFlags.UseIPv6,
Timeout: hub.QueryFlags.Timeout * time.Second,
UseTLS: false,
UseTCP: false,
})
if err != nil {
return err
}
hub.Resolver = append(hub.Resolver, rslvr)
}
}
return nil
}