// resolveOnce implements resolver.
// TXT records for a given domain name should contain a b58
// encoded multihash.
func (r *DNSResolver) resolveOnce(ctx context.Context, name string) (path.Path, error) {
segments := strings.SplitN(name, "/", 2)
domain := segments[0]
if !isd.IsDomain(domain) {
return "", errors.New("not a valid domain name")
}
log.Infof("DNSResolver resolving %s", domain)
rootChan := make(chan lookupRes, 1)
go workDomain(r, domain, rootChan)
subChan := make(chan lookupRes, 1)
go workDomain(r, "_dnslink."+domain, subChan)
var subRes lookupRes
select {
case subRes = <-subChan:
case <-ctx.Done():
return "", ctx.Err()
}
var p path.Path
if subRes.error == nil {
p = subRes.path
} else {
var rootRes lookupRes
select {
case rootRes = <-rootChan:
case <-ctx.Done():
return "", ctx.Err()
}
if rootRes.error == nil {
p = rootRes.path
} else {
return "", ErrResolveFailed
}
}
if len(segments) > 1 {
return path.FromSegments("", strings.TrimRight(p.String(), "/"), segments[1])
} else {
return p, nil
}
}
// IPNSHostnameOption rewrites an incoming request if its Host: header contains
// an IPNS name.
// The rewritten request points at the resolved name on the gateway handler.
func IPNSHostnameOption() ServeOption {
return func(n *core.IpfsNode, _ net.Listener, mux *http.ServeMux) (*http.ServeMux, error) {
childMux := http.NewServeMux()
mux.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
ctx, cancel := context.WithCancel(n.Context())
defer cancel()
host := strings.SplitN(r.Host, ":", 2)[0]
if len(host) > 0 && isd.IsDomain(host) {
name := "/ipns/" + host
if _, err := n.Namesys.Resolve(ctx, name); err == nil {
r.Header["X-Ipns-Original-Path"] = []string{r.URL.Path}
r.URL.Path = name + r.URL.Path
}
}
childMux.ServeHTTP(w, r)
})
return childMux, nil
}
}