ceremonyclient/go-libp2p/p2p/http/libp2phttp.go
Cassie Heart ebb31fd792 v1.4.19
2024-06-08 11:32:45 +00:00

919 lines
28 KiB
Go

// HTTP semantics with libp2p. Can use a libp2p stream transport or stock HTTP
// transports. This API is experimental and will likely change soon. Implements [libp2p spec #508](https://github.com/libp2p/specs/pull/508).
package libp2phttp
import (
"bufio"
"context"
"crypto/tls"
"encoding/json"
"errors"
"fmt"
"io"
"net"
"net/http"
"net/url"
"strconv"
"strings"
"sync"
"time"
lru "github.com/hashicorp/golang-lru/v2"
logging "github.com/ipfs/go-log/v2"
host "github.com/libp2p/go-libp2p/core/host"
"github.com/libp2p/go-libp2p/core/network"
"github.com/libp2p/go-libp2p/core/peer"
"github.com/libp2p/go-libp2p/core/peerstore"
"github.com/libp2p/go-libp2p/core/protocol"
gostream "github.com/libp2p/go-libp2p/p2p/net/gostream"
ma "github.com/multiformats/go-multiaddr"
)
var log = logging.Logger("libp2phttp")
var WellKnownRequestTimeout = 30 * time.Second
const ProtocolIDForMultistreamSelect = "/http/1.1"
const WellKnownProtocols = "/.well-known/libp2p/protocols"
// LegacyWellKnownProtocols refer to a the well-known resource used in an early
// draft of the libp2p+http spec. Some users have deployed this, and need backwards compatibility.
// Hopefully we can phase this out in the future. Context: https://github.com/libp2p/go-libp2p/pull/2797
const LegacyWellKnownProtocols = "/.well-known/libp2p"
const peerMetadataLimit = 8 << 10 // 8KB
const peerMetadataLRUSize = 256 // How many different peer's metadata to keep in our LRU cache
// ProtocolMeta is metadata about a protocol.
type ProtocolMeta struct {
// Path defines the HTTP Path prefix used for this protocol
Path string `json:"path"`
}
type PeerMeta map[protocol.ID]ProtocolMeta
// WellKnownHandler is an http.Handler that serves the well-known resource
type WellKnownHandler struct {
wellknownMapMu sync.Mutex
wellKnownMapping PeerMeta
wellKnownCache []byte
}
// streamHostListen returns a net.Listener that listens on libp2p streams for HTTP/1.1 messages.
func streamHostListen(streamHost host.Host) (net.Listener, error) {
return gostream.Listen(streamHost, ProtocolIDForMultistreamSelect)
}
func (h *WellKnownHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
// Check if the requests accepts JSON
accepts := r.Header.Get("Accept")
if accepts != "" && !(strings.Contains(accepts, "application/json") || strings.Contains(accepts, "*/*")) {
http.Error(w, "Only application/json is supported", http.StatusNotAcceptable)
return
}
if r.Method != http.MethodGet {
http.Error(w, "Only GET requests are supported", http.StatusMethodNotAllowed)
return
}
// Return a JSON object with the well-known protocols
h.wellknownMapMu.Lock()
mapping := h.wellKnownCache
var err error
if mapping == nil {
mapping, err = json.Marshal(h.wellKnownMapping)
if err == nil {
h.wellKnownCache = mapping
}
}
h.wellknownMapMu.Unlock()
if err != nil {
http.Error(w, "Marshal error", http.StatusInternalServerError)
return
}
w.Header().Add("Content-Type", "application/json")
w.Header().Add("Content-Length", strconv.Itoa(len(mapping)))
w.Write(mapping)
}
func (h *WellKnownHandler) AddProtocolMeta(p protocol.ID, protocolMeta ProtocolMeta) {
h.wellknownMapMu.Lock()
if h.wellKnownMapping == nil {
h.wellKnownMapping = make(map[protocol.ID]ProtocolMeta)
}
h.wellKnownMapping[p] = protocolMeta
h.wellKnownCache = nil
h.wellknownMapMu.Unlock()
}
func (h *WellKnownHandler) RemoveProtocolMeta(p protocol.ID) {
h.wellknownMapMu.Lock()
if h.wellKnownMapping != nil {
delete(h.wellKnownMapping, p)
}
h.wellKnownCache = nil
h.wellknownMapMu.Unlock()
}
// Host is a libp2p host for request/responses with HTTP semantics. This is
// in contrast to a stream-oriented host like the core host.Host interface. Its
// zero-value (&Host{}) is usable. Do not copy by value.
// See examples for usage.
//
// Warning, this is experimental. The API will likely change.
type Host struct {
// StreamHost is a stream based libp2p host used to do HTTP over libp2p streams. May be nil
StreamHost host.Host
// ListenAddrs are the requested addresses to listen on. Multiaddrs must be
// valid HTTP(s) multiaddr. Only multiaddrs for an HTTP transport are
// supported (must end with /http or /https).
ListenAddrs []ma.Multiaddr
// TLSConfig is the TLS config for the server to use
TLSConfig *tls.Config
// InsecureAllowHTTP indicates if the server is allowed to serve unencrypted
// HTTP requests over TCP.
InsecureAllowHTTP bool
// ServeMux is the http.ServeMux used by the server to serve requests. If
// nil, a new serve mux will be created. Users may manually add handlers to
// this mux instead of using `SetHTTPHandler`, but if they do, they should
// also update the WellKnownHandler's protocol mapping.
ServeMux *http.ServeMux
initializeServeMux sync.Once
// DefaultClientRoundTripper is the default http.RoundTripper for clients to
// use when making requests over an HTTP transport. This must be an
// `*http.Transport` type so that the transport can be cloned and the
// `TLSClientConfig` field can be configured. If unset, it will create a new
// `http.Transport` on first use.
DefaultClientRoundTripper *http.Transport
// WellKnownHandler is the http handler for the well-known
// resource. It is responsible for sharing this node's protocol metadata
// with other nodes. Users only care about this if they set their own
// ServeMux with pre-existing routes. By default, new protocols are added
// here when a user calls `SetHTTPHandler` or `SetHTTPHandlerAtPath`.
WellKnownHandler WellKnownHandler
// EnableCompatibilityWithLegacyWellKnownEndpoint allows compatibility with
// an older version of the spec that defined the well-known resource as:
// .well-known/libp2p.
// For servers, this means hosting the well-known resource at both the
// legacy and current paths.
// For clients it means making two parallel requests and picking the first one that succeeds.
//
// Long term this should be deprecated once enough users have upgraded to a
// newer go-libp2p version and we can remove all this code.
EnableCompatibilityWithLegacyWellKnownEndpoint bool
// peerMetadata is an LRU cache of a peer's well-known protocol map.
peerMetadata *lru.Cache[peer.ID, PeerMeta]
// createHTTPTransport is used to lazily create the httpTransport in a thread-safe way.
createHTTPTransport sync.Once
// createDefaultClientRoundTripper is used to lazily create the default
// client round tripper in a thread-safe way.
createDefaultClientRoundTripper sync.Once
httpTransport *httpTransport
}
type httpTransport struct {
listenAddrs []ma.Multiaddr
listeners []net.Listener
closeListeners chan struct{}
waitingForListeners chan struct{}
}
func newPeerMetadataCache() *lru.Cache[peer.ID, PeerMeta] {
peerMetadata, err := lru.New[peer.ID, PeerMeta](peerMetadataLRUSize)
if err != nil {
// Only happens if size is < 1. We make sure to not do that, so this should never happen.
panic(err)
}
return peerMetadata
}
func (h *Host) httpTransportInit() {
h.createHTTPTransport.Do(func() {
h.httpTransport = &httpTransport{
closeListeners: make(chan struct{}),
waitingForListeners: make(chan struct{}),
}
})
}
func (h *Host) serveMuxInit() {
h.initializeServeMux.Do(func() {
if h.ServeMux == nil {
h.ServeMux = http.NewServeMux()
}
})
}
func (h *Host) Addrs() []ma.Multiaddr {
h.httpTransportInit()
<-h.httpTransport.waitingForListeners
return h.httpTransport.listenAddrs
}
// ID returns the peer ID of the underlying stream host, or the zero value if there is no stream host.
func (h *Host) PeerID() peer.ID {
if h.StreamHost != nil {
return h.StreamHost.ID()
}
return ""
}
var ErrNoListeners = errors.New("nothing to listen on")
func (h *Host) setupListeners(listenerErrCh chan error) error {
for _, addr := range h.ListenAddrs {
parsedAddr := parseMultiaddr(addr)
// resolve the host
ipaddr, err := net.ResolveIPAddr("ip", parsedAddr.host)
if err != nil {
return err
}
host := ipaddr.String()
l, err := net.Listen("tcp", host+":"+parsedAddr.port)
if err != nil {
return err
}
h.httpTransport.listeners = append(h.httpTransport.listeners, l)
// get resolved port
_, port, err := net.SplitHostPort(l.Addr().String())
if err != nil {
return err
}
var listenAddr ma.Multiaddr
if parsedAddr.useHTTPS && parsedAddr.sni != "" && parsedAddr.sni != host {
listenAddr = ma.StringCast(fmt.Sprintf("/ip4/%s/tcp/%s/tls/sni/%s/http", host, port, parsedAddr.sni))
} else {
scheme := "http"
if parsedAddr.useHTTPS {
scheme = "https"
}
listenAddr = ma.StringCast(fmt.Sprintf("/ip4/%s/tcp/%s/%s", host, port, scheme))
}
if parsedAddr.useHTTPS {
go func() {
srv := http.Server{
Handler: h.ServeMux,
TLSConfig: h.TLSConfig,
}
listenerErrCh <- srv.ServeTLS(l, "", "")
}()
h.httpTransport.listenAddrs = append(h.httpTransport.listenAddrs, listenAddr)
} else if h.InsecureAllowHTTP {
go func() {
listenerErrCh <- http.Serve(l, h.ServeMux)
}()
h.httpTransport.listenAddrs = append(h.httpTransport.listenAddrs, listenAddr)
} else {
// We are not serving insecure HTTP
log.Warnf("Not serving insecure HTTP on %s. Prefer an HTTPS endpoint.", listenAddr)
}
}
return nil
}
// Serve starts the HTTP transport listeners. Always returns a non-nil error.
// If there are no listeners, returns ErrNoListeners.
func (h *Host) Serve() error {
// assert that each addr contains a /http component
for _, addr := range h.ListenAddrs {
_, isHTTP := normalizeHTTPMultiaddr(addr)
if !isHTTP {
return fmt.Errorf("address %s does not contain a /http or /https component", addr)
}
}
h.serveMuxInit()
h.ServeMux.Handle(WellKnownProtocols, &h.WellKnownHandler)
if h.EnableCompatibilityWithLegacyWellKnownEndpoint {
h.ServeMux.Handle(LegacyWellKnownProtocols, &h.WellKnownHandler)
}
h.httpTransportInit()
closedWaitingForListeners := false
defer func() {
if !closedWaitingForListeners {
close(h.httpTransport.waitingForListeners)
}
}()
if len(h.ListenAddrs) == 0 && h.StreamHost == nil {
return ErrNoListeners
}
h.httpTransport.listeners = make([]net.Listener, 0, len(h.ListenAddrs)+1) // +1 for stream host
streamHostAddrsCount := 0
if h.StreamHost != nil {
streamHostAddrsCount = len(h.StreamHost.Addrs())
}
h.httpTransport.listenAddrs = make([]ma.Multiaddr, 0, len(h.ListenAddrs)+streamHostAddrsCount)
errCh := make(chan error)
if h.StreamHost != nil {
listener, err := streamHostListen(h.StreamHost)
if err != nil {
return err
}
h.httpTransport.listeners = append(h.httpTransport.listeners, listener)
h.httpTransport.listenAddrs = append(h.httpTransport.listenAddrs, h.StreamHost.Addrs()...)
go func() {
errCh <- http.Serve(listener, connectionCloseHeaderMiddleware(h.ServeMux))
}()
}
closeAllListeners := func() {
for _, l := range h.httpTransport.listeners {
l.Close()
}
}
err := h.setupListeners(errCh)
if err != nil {
closeAllListeners()
return err
}
close(h.httpTransport.waitingForListeners)
closedWaitingForListeners = true
if len(h.httpTransport.listeners) == 0 || len(h.httpTransport.listenAddrs) == 0 {
closeAllListeners()
return ErrNoListeners
}
expectedErrCount := len(h.httpTransport.listeners)
select {
case <-h.httpTransport.closeListeners:
case err = <-errCh:
expectedErrCount--
}
// Close all listeners
closeAllListeners()
for i := 0; i < expectedErrCount; i++ {
<-errCh
}
close(errCh)
return err
}
func (h *Host) Close() error {
h.httpTransportInit()
close(h.httpTransport.closeListeners)
return nil
}
// SetHTTPHandler sets the HTTP handler for a given protocol. Automatically
// manages the well-known resource mapping.
// http.StripPrefix is called on the handler, so the handler will be unaware of
// its prefix path.
func (h *Host) SetHTTPHandler(p protocol.ID, handler http.Handler) {
h.SetHTTPHandlerAtPath(p, string(p), handler)
}
// SetHTTPHandlerAtPath sets the HTTP handler for a given protocol using the
// given path. Automatically manages the well-known resource mapping.
// http.StripPrefix is called on the handler, so the handler will be unaware of
// its prefix path.
func (h *Host) SetHTTPHandlerAtPath(p protocol.ID, path string, handler http.Handler) {
if path == "" || path[len(path)-1] != '/' {
// We are nesting this handler under this path, so it should end with a slash.
path += "/"
}
h.WellKnownHandler.AddProtocolMeta(p, ProtocolMeta{Path: path})
h.serveMuxInit()
// Do not trim the trailing / from path
// This allows us to serve `/a/b` when we mount a handler for `/b` at path `/a`
h.ServeMux.Handle(path, http.StripPrefix(strings.TrimSuffix(path, "/"), handler))
}
// PeerMetadataGetter lets RoundTrippers implement a specific way of caching a peer's protocol mapping.
type PeerMetadataGetter interface {
GetPeerMetadata() (PeerMeta, error)
}
type streamRoundTripper struct {
server peer.ID
addrsAdded sync.Once
serverAddrs []ma.Multiaddr
h host.Host
httpHost *Host
}
// streamReadCloser wraps an io.ReadCloser and closes the underlying stream when
// closed (as well as closing the wrapped ReadCloser). This is necessary because
// we have two things to close, the body and the stream. The stream isn't closed
// by the body automatically, as hinted at by the fact that `http.ReadResponse`
// takes a bufio.Reader.
type streamReadCloser struct {
io.ReadCloser
s network.Stream
}
func (s *streamReadCloser) Close() error {
s.s.Close()
return s.ReadCloser.Close()
}
func (rt *streamRoundTripper) GetPeerMetadata() (PeerMeta, error) {
ctx := context.Background()
ctx, cancel := context.WithDeadline(ctx, time.Now().Add(WellKnownRequestTimeout))
defer cancel()
return rt.httpHost.getAndStorePeerMetadata(ctx, rt, rt.server)
}
// RoundTrip implements http.RoundTripper.
func (rt *streamRoundTripper) RoundTrip(r *http.Request) (*http.Response, error) {
// Add the addresses we learned about for this server
rt.addrsAdded.Do(func() {
if len(rt.serverAddrs) > 0 {
rt.h.Peerstore().AddAddrs(rt.server, rt.serverAddrs, peerstore.TempAddrTTL)
}
rt.serverAddrs = nil // may as well cleanup
})
s, err := rt.h.NewStream(r.Context(), rt.server, ProtocolIDForMultistreamSelect)
if err != nil {
return nil, err
}
// Write connection: close header to ensure the stream is closed after the response
r.Header.Add("connection", "close")
go func() {
defer s.CloseWrite()
r.Write(s)
if r.Body != nil {
r.Body.Close()
}
}()
if deadline, ok := r.Context().Deadline(); ok {
s.SetReadDeadline(deadline)
}
resp, err := http.ReadResponse(bufio.NewReader(s), r)
if err != nil {
s.Close()
return nil, err
}
resp.Body = &streamReadCloser{resp.Body, s}
return resp, nil
}
// roundTripperForSpecificServer is an http.RoundTripper targets a specific server. Still reuses the underlying RoundTripper for the requests.
// The underlying RoundTripper MUST be an HTTP Transport.
type roundTripperForSpecificServer struct {
http.RoundTripper
ownRoundtripper bool
httpHost *Host
server peer.ID
targetServerAddr string
sni string
scheme string
cachedProtos PeerMeta
}
func (rt *roundTripperForSpecificServer) GetPeerMetadata() (PeerMeta, error) {
// Do we already have the peer's protocol mapping?
if rt.cachedProtos != nil {
return rt.cachedProtos, nil
}
// if the underlying roundtripper implements GetPeerMetadata, use that
if g, ok := rt.RoundTripper.(PeerMetadataGetter); ok {
wk, err := g.GetPeerMetadata()
if err == nil {
rt.cachedProtos = wk
return wk, nil
}
}
ctx := context.Background()
ctx, cancel := context.WithDeadline(ctx, time.Now().Add(WellKnownRequestTimeout))
defer cancel()
wk, err := rt.httpHost.getAndStorePeerMetadata(ctx, rt, rt.server)
if err == nil {
rt.cachedProtos = wk
return wk, nil
}
return wk, err
}
// RoundTrip implements http.RoundTripper.
func (rt *roundTripperForSpecificServer) RoundTrip(r *http.Request) (*http.Response, error) {
if (r.URL.Scheme != "" && r.URL.Scheme != rt.scheme) || (r.URL.Host != "" && r.URL.Host != rt.targetServerAddr) {
return nil, fmt.Errorf("this transport is only for requests to %s://%s", rt.scheme, rt.targetServerAddr)
}
r.URL.Scheme = rt.scheme
r.URL.Host = rt.targetServerAddr
r.Host = rt.sni
return rt.RoundTripper.RoundTrip(r)
}
func (rt *roundTripperForSpecificServer) CloseIdleConnections() {
if rt.ownRoundtripper {
// Safe to close idle connections, since we own the RoundTripper. We
// aren't closing other's idle connections.
type closeIdler interface {
CloseIdleConnections()
}
if tr, ok := rt.RoundTripper.(closeIdler); ok {
tr.CloseIdleConnections()
}
}
// No-op, since we don't want users thinking they are closing idle
// connections for this server, when in fact they are closing all idle
// connections
}
// namespacedRoundTripper is a round tripper that prefixes all requests with a
// given path prefix. It is used to namespace requests to a specific protocol.
type namespacedRoundTripper struct {
http.RoundTripper
protocolPrefix string
protocolPrefixRaw string
}
func (rt *namespacedRoundTripper) GetPeerMetadata() (PeerMeta, error) {
if g, ok := rt.RoundTripper.(PeerMetadataGetter); ok {
return g.GetPeerMetadata()
}
return nil, fmt.Errorf("can not get peer protocol map. Inner roundtripper does not implement GetPeerMetadata")
}
// RoundTrip implements http.RoundTripper.
func (rt *namespacedRoundTripper) RoundTrip(r *http.Request) (*http.Response, error) {
if !strings.HasPrefix(r.URL.Path, rt.protocolPrefix) {
r.URL.Path = rt.protocolPrefix + r.URL.Path
}
if !strings.HasPrefix(r.URL.RawPath, rt.protocolPrefixRaw) {
r.URL.RawPath = rt.protocolPrefixRaw + r.URL.Path
}
return rt.RoundTripper.RoundTrip(r)
}
// NamespaceRoundTripper returns an http.RoundTripper that are scoped to the given protocol on the given server.
func (h *Host) NamespaceRoundTripper(roundtripper http.RoundTripper, p protocol.ID, server peer.ID) (*namespacedRoundTripper, error) {
ctx := context.Background()
ctx, cancel := context.WithDeadline(ctx, time.Now().Add(WellKnownRequestTimeout))
defer cancel()
protos, err := h.getAndStorePeerMetadata(ctx, roundtripper, server)
if err != nil {
return &namespacedRoundTripper{}, err
}
v, ok := protos[p]
if !ok {
return &namespacedRoundTripper{}, fmt.Errorf("no protocol %s for server %s", p, server)
}
path := v.Path
if path[len(path)-1] == '/' {
// Trim the trailing slash, since it's common to make requests starting with a leading forward slash for the path
path = path[:len(path)-1]
}
u, err := url.Parse(path)
if err != nil {
return &namespacedRoundTripper{}, fmt.Errorf("invalid path %s for protocol %s for server %s", v.Path, p, server)
}
return &namespacedRoundTripper{
RoundTripper: roundtripper,
protocolPrefix: u.Path,
protocolPrefixRaw: u.RawPath,
}, nil
}
// NamespacedClient returns an http.Client that is scoped to the given protocol
// on the given server. It creates a new RoundTripper for each call. If you are
// creating many namespaced clients, consider creating a round tripper directly
// and namespacing the roundripper yourself, then creating clients from the
// namespace round tripper.
func (h *Host) NamespacedClient(p protocol.ID, server peer.AddrInfo, opts ...RoundTripperOption) (http.Client, error) {
rt, err := h.NewConstrainedRoundTripper(server, opts...)
if err != nil {
return http.Client{}, err
}
nrt, err := h.NamespaceRoundTripper(rt, p, server.ID)
if err != nil {
return http.Client{}, err
}
return http.Client{Transport: nrt}, nil
}
// NewConstrainedRoundTripper returns an http.RoundTripper that can fulfill and HTTP
// request to the given server. It may use an HTTP transport or a stream based
// transport. It is valid to pass an empty server.ID.
// If there are multiple addresses for the server, it will pick the best
// transport (stream vs standard HTTP) using the following rules:
// - If PreferHTTPTransport is set, use the HTTP transport.
// - If ServerMustAuthenticatePeerID is set, use the stream transport, as the
// HTTP transport does not do peer id auth yet.
// - If we already have a connection on a stream transport, use that.
// - Otherwise, if we have both, use the HTTP transport.
func (h *Host) NewConstrainedRoundTripper(server peer.AddrInfo, opts ...RoundTripperOption) (http.RoundTripper, error) {
options := roundTripperOpts{}
for _, o := range opts {
options = o(options)
}
if options.serverMustAuthenticatePeerID && server.ID == "" {
return nil, fmt.Errorf("server must authenticate peer ID, but no peer ID provided")
}
httpAddrs := make([]ma.Multiaddr, 0, 1) // The common case of a single http address
nonHTTPAddrs := make([]ma.Multiaddr, 0, len(server.Addrs))
firstAddrIsHTTP := false
for i, addr := range server.Addrs {
addr, isHTTP := normalizeHTTPMultiaddr(addr)
if isHTTP {
if i == 0 {
firstAddrIsHTTP = true
}
httpAddrs = append(httpAddrs, addr)
} else {
nonHTTPAddrs = append(nonHTTPAddrs, addr)
}
}
// Do we have an existing connection to this peer?
existingStreamConn := false
if server.ID != "" && h.StreamHost != nil {
existingStreamConn = len(h.StreamHost.Network().ConnsToPeer(server.ID)) > 0
}
// Currently the HTTP transport can not authenticate peer IDs.
if !options.serverMustAuthenticatePeerID && len(httpAddrs) > 0 && (options.preferHTTPTransport || (firstAddrIsHTTP && !existingStreamConn)) {
parsed := parseMultiaddr(httpAddrs[0])
scheme := "http"
if parsed.useHTTPS {
scheme = "https"
}
h.createDefaultClientRoundTripper.Do(func() {
if h.DefaultClientRoundTripper == nil {
h.DefaultClientRoundTripper = &http.Transport{}
}
})
rt := h.DefaultClientRoundTripper
ownRoundtripper := false
if parsed.sni != parsed.host {
// We have a different host and SNI (e.g. using an IP address but specifying a SNI)
// We need to make our own transport to support this.
rt = rt.Clone()
rt.TLSClientConfig.ServerName = parsed.sni
ownRoundtripper = true
}
return &roundTripperForSpecificServer{
RoundTripper: rt,
ownRoundtripper: ownRoundtripper,
httpHost: h,
server: server.ID,
targetServerAddr: parsed.host + ":" + parsed.port,
sni: parsed.sni,
scheme: scheme,
}, nil
}
// Otherwise use a stream based transport
if h.StreamHost == nil {
return nil, fmt.Errorf("can not use the HTTP transport (either no address or PeerID auth is required), and no stream host provided")
}
if !existingStreamConn {
if server.ID == "" {
return nil, fmt.Errorf("can not use the HTTP transport, and no server peer ID provided")
}
}
return &streamRoundTripper{h: h.StreamHost, server: server.ID, serverAddrs: nonHTTPAddrs, httpHost: h}, nil
}
type httpMultiaddr struct {
useHTTPS bool
host string
port string
sni string
}
func parseMultiaddr(addr ma.Multiaddr) httpMultiaddr {
out := httpMultiaddr{}
ma.ForEach(addr, func(c ma.Component) bool {
switch c.Protocol().Code {
case ma.P_IP4, ma.P_IP6, ma.P_DNS, ma.P_DNS4, ma.P_DNS6:
out.host = c.Value()
case ma.P_TCP, ma.P_UDP:
out.port = c.Value()
case ma.P_TLS, ma.P_HTTPS:
out.useHTTPS = true
case ma.P_SNI:
out.sni = c.Value()
}
return out.host == "" || out.port == "" || !out.useHTTPS || out.sni == ""
})
if out.useHTTPS && out.sni == "" {
out.sni = out.host
}
return out
}
var httpComponent, _ = ma.NewComponent("http", "")
var tlsComponent, _ = ma.NewComponent("tls", "")
// normalizeHTTPMultiaddr converts an https multiaddr to a tls/http one.
// Returns a bool indicating if the input multiaddr has an http (or https) component.
func normalizeHTTPMultiaddr(addr ma.Multiaddr) (ma.Multiaddr, bool) {
isHTTPMultiaddr := false
beforeHTTPS, afterIncludingHTTPS := ma.SplitFunc(addr, func(c ma.Component) bool {
if c.Protocol().Code == ma.P_HTTP {
isHTTPMultiaddr = true
}
if c.Protocol().Code == ma.P_HTTPS {
isHTTPMultiaddr = true
return true
}
return false
})
if afterIncludingHTTPS == nil {
// No HTTPS component, just return the original
return addr, isHTTPMultiaddr
}
_, afterHTTPS := ma.SplitFirst(afterIncludingHTTPS)
if afterHTTPS == nil {
return ma.Join(beforeHTTPS, tlsComponent, httpComponent), isHTTPMultiaddr
}
return ma.Join(beforeHTTPS, tlsComponent, httpComponent, afterHTTPS), isHTTPMultiaddr
}
// getAndStorePeerMetadata looks up the protocol path in the well-known mapping and
// returns it. Will only store the peer's protocol mapping if the server ID is
// provided.
func (h *Host) getAndStorePeerMetadata(ctx context.Context, roundtripper http.RoundTripper, server peer.ID) (PeerMeta, error) {
if h.peerMetadata == nil {
h.peerMetadata = newPeerMetadataCache()
}
if meta, ok := h.peerMetadata.Get(server); server != "" && ok {
return meta, nil
}
var meta PeerMeta
var err error
if h.EnableCompatibilityWithLegacyWellKnownEndpoint {
type metaAndErr struct {
m PeerMeta
err error
}
legacyRespCh := make(chan metaAndErr, 1)
wellKnownRespCh := make(chan metaAndErr, 1)
ctx, cancel := context.WithCancel(ctx)
go func() {
meta, err := requestPeerMeta(ctx, roundtripper, LegacyWellKnownProtocols)
legacyRespCh <- metaAndErr{meta, err}
}()
go func() {
meta, err := requestPeerMeta(ctx, roundtripper, WellKnownProtocols)
wellKnownRespCh <- metaAndErr{meta, err}
}()
select {
case resp := <-legacyRespCh:
if resp.err != nil {
resp = <-wellKnownRespCh
}
meta, err = resp.m, resp.err
case resp := <-wellKnownRespCh:
if resp.err != nil {
legacyResp := <-legacyRespCh
if legacyResp.err != nil {
// If both endpoints error, return the error from the well
// known resource (not the legacy well known resource)
meta, err = resp.m, resp.err
} else {
meta, err = legacyResp.m, legacyResp.err
}
} else {
meta, err = resp.m, resp.err
}
}
cancel()
} else {
meta, err = requestPeerMeta(ctx, roundtripper, WellKnownProtocols)
}
if err != nil {
return nil, err
}
if server != "" {
h.peerMetadata.Add(server, meta)
}
return meta, nil
}
func requestPeerMeta(ctx context.Context, roundtripper http.RoundTripper, wellKnownResource string) (PeerMeta, error) {
req, err := http.NewRequest("GET", wellKnownResource, nil)
if err != nil {
return nil, err
}
req.Header.Set("Accept", "application/json")
client := http.Client{Transport: roundtripper}
resp, err := client.Do(req)
if err != nil {
return nil, err
}
defer resp.Body.Close()
if resp.StatusCode != http.StatusOK {
return nil, fmt.Errorf("unexpected status code: %d", resp.StatusCode)
}
meta := PeerMeta{}
err = json.NewDecoder(&io.LimitedReader{
R: resp.Body,
N: peerMetadataLimit,
}).Decode(&meta)
if err != nil {
return nil, err
}
return meta, nil
}
// SetPeerMetadata adds a peer's protocol metadata to the http host. Useful if
// you have out-of-band knowledge of a peer's protocol mapping.
func (h *Host) SetPeerMetadata(server peer.ID, meta PeerMeta) {
if h.peerMetadata == nil {
h.peerMetadata = newPeerMetadataCache()
}
h.peerMetadata.Add(server, meta)
}
// AddPeerMetadata merges the given peer's protocol metadata to the http host. Useful if
// you have out-of-band knowledge of a peer's protocol mapping.
func (h *Host) AddPeerMetadata(server peer.ID, meta PeerMeta) {
if h.peerMetadata == nil {
h.peerMetadata = newPeerMetadataCache()
}
origMeta, ok := h.peerMetadata.Get(server)
if !ok {
h.peerMetadata.Add(server, meta)
return
}
for proto, m := range meta {
origMeta[proto] = m
}
h.peerMetadata.Add(server, origMeta)
}
// GetPeerMetadata gets a peer's cached protocol metadata from the http host.
func (h *Host) GetPeerMetadata(server peer.ID) (PeerMeta, bool) {
if h.peerMetadata == nil {
return nil, false
}
return h.peerMetadata.Get(server)
}
// RemovePeerMetadata removes a peer's protocol metadata from the http host
func (h *Host) RemovePeerMetadata(server peer.ID) {
if h.peerMetadata == nil {
return
}
h.peerMetadata.Remove(server)
}
func connectionCloseHeaderMiddleware(next http.Handler) http.Handler {
// Sets connection: close. It's preferable to not reuse streams for HTTP.
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
w.Header().Set("Connection", "close")
next.ServeHTTP(w, r)
})
}