package vpn

import "tailscale.com/net/dns"

func NewDNSConfigurator(t *Tunnel) dns.OSConfigurator {

return &dnsManager{tunnel: t}

}

type dnsManager struct {

tunnel *Tunnel

}

func (v *dnsManager) SetDNS(cfg dns.OSConfig) error {

settings := convertDNSConfig(cfg)

return v.tunnel.ApplyNetworkSettings(v.tunnel.ctx, &NetworkSettingsRequest{

DnsSettings: settings,

})

}

func (*dnsManager) GetBaseConfig() (dns.OSConfig, error) {

// Tailscale calls this function to blend the OS's DNS configuration with

// it's own, so this is only called if `SupportsSplitDNS` returns false.

return dns.OSConfig{}, dns.ErrGetBaseConfigNotSupported

}

func (*dnsManager) SupportsSplitDNS() bool {

// macOS & Windows 10+ support split DNS, so we'll assume all CoderVPN

// clients do too.

return true

}

// Close implements dns.OSConfigurator.

func (*dnsManager) Close() error {

// There's no cleanup that we need to initiate from within the dylib.

return nil

}

func convertDNSConfig(cfg dns.OSConfig) *NetworkSettingsRequest_DNSSettings {

servers := make([]string, 0, len(cfg.Nameservers))

for _, ns := range cfg.Nameservers {

servers = append(servers, ns.String())

}

searchDomains := make([]string, 0, len(cfg.SearchDomains))

for _, domain := range cfg.SearchDomains {

searchDomains = append(searchDomains, domain.WithoutTrailingDot())

}

matchDomains := make([]string, 0, len(cfg.MatchDomains))

for _, domain := range cfg.MatchDomains {

matchDomains = append(matchDomains, domain.WithoutTrailingDot())

}

return &NetworkSettingsRequest_DNSSettings{

Servers: servers,

SearchDomains: searchDomains,

DomainName: "coder",

MatchDomains: matchDomains,

MatchDomainsNoSearch: false,

}

}