diff --git a/agent/pkg/handler/handler.go b/agent/pkg/handler/handler.go index 9d07556..1835616 100644 --- a/agent/pkg/handler/handler.go +++ b/agent/pkg/handler/handler.go @@ -1,17 +1,14 @@ package handler import ( - "context" "fmt" - "net" "net/http" - "net/http/httputil" - "time" "github.com/yusing/go-proxy/agent/pkg/agent" "github.com/yusing/go-proxy/agent/pkg/env" "github.com/yusing/go-proxy/internal/metrics/systeminfo" "github.com/yusing/go-proxy/pkg" + socketproxy "github.com/yusing/go-proxy/socketproxy/pkg" ) type ServeMux struct{ *http.ServeMux } @@ -24,26 +21,6 @@ func (mux ServeMux) HandleFunc(endpoint string, handler http.HandlerFunc) { mux.ServeMux.HandleFunc(agent.APIEndpointBase+endpoint, handler) } -var dialer = &net.Dialer{KeepAlive: 1 * time.Second} - -func dialDockerSocket(ctx context.Context, _, _ string) (net.Conn, error) { - return dialer.DialContext(ctx, "unix", env.DockerSocket) -} - -func dockerSocketHandler() http.HandlerFunc { - rp := httputil.ReverseProxy{ - Director: func(r *http.Request) { - r.URL.Scheme = "http" - r.URL.Host = "api.moby.localhost" - r.RequestURI = r.URL.String() - }, - Transport: &http.Transport{ - DialContext: dialDockerSocket, - }, - } - return rp.ServeHTTP -} - func NewAgentHandler() http.Handler { mux := ServeMux{http.NewServeMux()} @@ -54,6 +31,6 @@ func NewAgentHandler() http.Handler { }) mux.HandleEndpoint("GET", agent.EndpointHealth, CheckHealth) mux.HandleEndpoint("GET", agent.EndpointSystemInfo, systeminfo.Poller.ServeHTTP) - mux.ServeMux.HandleFunc("/", dockerSocketHandler()) + mux.ServeMux.HandleFunc("/", socketproxy.DockerSocketHandler(env.DockerSocket)) return mux } diff --git a/internal/api/v1/dockerapi/logs.go b/internal/api/v1/dockerapi/logs.go index 385b59e..916fa3f 100644 --- a/internal/api/v1/dockerapi/logs.go +++ b/internal/api/v1/dockerapi/logs.go @@ -15,6 +15,7 @@ import ( "github.com/yusing/go-proxy/internal/task" ) +// FIXME: agent logs not updating. func Logs(w http.ResponseWriter, r *http.Request) { query := r.URL.Query() server := r.PathValue("server") diff --git a/internal/docker/client.go b/internal/docker/client.go index afadf20..7e1b892 100644 --- a/internal/docker/client.go +++ b/internal/docker/client.go @@ -20,6 +20,7 @@ import ( "github.com/yusing/go-proxy/internal/task" ) +// TODO: implement reconnect here. type ( SharedClient struct { *client.Client diff --git a/socket-proxy/go.mod b/socket-proxy/go.mod index cd8a7de..5c83f0b 100644 --- a/socket-proxy/go.mod +++ b/socket-proxy/go.mod @@ -2,4 +2,19 @@ module github.com/yusing/go-proxy/socketproxy go 1.24.3 -require github.com/gorilla/mux v1.8.1 +replace github.com/yusing/go-proxy/internal/utils => ../internal/utils + +require ( + github.com/gorilla/mux v1.8.1 + github.com/yusing/go-proxy/internal/utils v0.0.0-00010101000000-000000000000 + golang.org/x/net v0.40.0 +) + +require ( + github.com/mattn/go-colorable v0.1.14 // indirect + github.com/mattn/go-isatty v0.0.20 // indirect + github.com/rs/zerolog v1.34.0 // indirect + go.uber.org/atomic v1.11.0 // indirect + golang.org/x/sys v0.33.0 // indirect + golang.org/x/text v0.25.0 // indirect +) diff --git a/socket-proxy/go.sum b/socket-proxy/go.sum index 7128337..7967116 100644 --- a/socket-proxy/go.sum +++ b/socket-proxy/go.sum @@ -1,2 +1,34 @@ +github.com/coreos/go-systemd/v22 v22.5.0/go.mod h1:Y58oyj3AT4RCenI/lSvhwexgC+NSVTIJ3seZv2GcEnc= +github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc h1:U9qPSI2PIWSS1VwoXQT9A3Wy9MM3WgvqSxFWenqJduM= +github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38= +github.com/godbus/dbus/v5 v5.0.4/go.mod h1:xhWf0FNVPg57R7Z0UbKHbJfkEywrmjJnf7w5xrFpKfA= github.com/gorilla/mux v1.8.1 h1:TuBL49tXwgrFYWhqrNgrUNEY92u81SPhu7sTdzQEiWY= github.com/gorilla/mux v1.8.1/go.mod h1:AKf9I4AEqPTmMytcMc0KkNouC66V3BtZ4qD5fmWSiMQ= +github.com/mattn/go-colorable v0.1.13/go.mod h1:7S9/ev0klgBDR4GtXTXX8a3vIGJpMovkB8vQcUbaXHg= +github.com/mattn/go-colorable v0.1.14 h1:9A9LHSqF/7dyVVX6g0U9cwm9pG3kP9gSzcuIPHPsaIE= +github.com/mattn/go-colorable v0.1.14/go.mod h1:6LmQG8QLFO4G5z1gPvYEzlUgJ2wF+stgPZH1UqBm1s8= +github.com/mattn/go-isatty v0.0.16/go.mod h1:kYGgaQfpe5nmfYZH+SKPsOc2e4SrIfOl2e/yFXSvRLM= +github.com/mattn/go-isatty v0.0.19/go.mod h1:W+V8PltTTMOvKvAeJH7IuucS94S2C6jfK/D7dTCTo3Y= +github.com/mattn/go-isatty v0.0.20 h1:xfD0iDuEKnDkl03q4limB+vH+GxLEtL/jb4xVJSWWEY= +github.com/mattn/go-isatty v0.0.20/go.mod h1:W+V8PltTTMOvKvAeJH7IuucS94S2C6jfK/D7dTCTo3Y= +github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0= +github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2 h1:Jamvg5psRIccs7FGNTlIRMkT8wgtp5eCXdBlqhYGL6U= +github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4= +github.com/rs/xid v1.6.0/go.mod h1:7XoLgs4eV+QndskICGsho+ADou8ySMSjJKDIan90Nz0= +github.com/rs/zerolog v1.34.0 h1:k43nTLIwcTVQAncfCw4KZ2VY6ukYoZaBPNOE8txlOeY= +github.com/rs/zerolog v1.34.0/go.mod h1:bJsvje4Z08ROH4Nhs5iH600c3IkWhwp44iRc54W6wYQ= +github.com/stretchr/testify v1.10.0 h1:Xv5erBjTwe/5IxqUQTdXv5kgmIvbHo3QQyRwhJsOfJA= +github.com/stretchr/testify v1.10.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY= +go.uber.org/atomic v1.11.0 h1:ZvwS0R+56ePWxUNi+Atn9dWONBPp/AUETXlHW0DxSjE= +go.uber.org/atomic v1.11.0/go.mod h1:LUxbIzbOniOlMKjJjyPfpl4v+PKK2cNJn91OQbhoJI0= +golang.org/x/net v0.40.0 h1:79Xs7wF06Gbdcg4kdCCIQArK11Z1hr5POQ6+fIYHNuY= +golang.org/x/net v0.40.0/go.mod h1:y0hY0exeL2Pku80/zKK7tpntoX23cqL3Oa6njdgRtds= +golang.org/x/sys v0.0.0-20220811171246-fbc7d0a398ab/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg= +golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg= +golang.org/x/sys v0.12.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg= +golang.org/x/sys v0.33.0 h1:q3i8TbbEz+JRD9ywIRlyRAQbM0qF7hu24q3teo2hbuw= +golang.org/x/sys v0.33.0/go.mod h1:BJP2sWEmIv4KK5OTEluFJCKSidICx8ciO85XgH3Ak8k= +golang.org/x/text v0.25.0 h1:qVyWApTSYLk/drJRO5mDlNYskwQznZmkpV2c8q9zls4= +golang.org/x/text v0.25.0/go.mod h1:WEdwpYrmk1qmdHvhkSTNPm3app7v4rsT8F2UD6+VHIA= +gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA= +gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM= diff --git a/socket-proxy/pkg/handler.go b/socket-proxy/pkg/handler.go index 51c2049..930bc9e 100644 --- a/socket-proxy/pkg/handler.go +++ b/socket-proxy/pkg/handler.go @@ -4,30 +4,33 @@ import ( "context" "net" "net/http" - "net/http/httputil" "strings" "time" "github.com/gorilla/mux" + "github.com/yusing/go-proxy/socketproxy/pkg/reverseproxy" ) var dialer = &net.Dialer{KeepAlive: 1 * time.Second} -func dialDockerSocket(ctx context.Context, _, _ string) (net.Conn, error) { - return dialer.DialContext(ctx, "unix", DockerSocket) +func dialDockerSocket(socket string) func(ctx context.Context, _, _ string) (net.Conn, error) { + return func(ctx context.Context, _, _ string) (net.Conn, error) { + return dialer.DialContext(ctx, "unix", socket) + } } var DockerSocketHandler = dockerSocketHandler -func dockerSocketHandler() http.HandlerFunc { - rp := &httputil.ReverseProxy{ +func dockerSocketHandler(socket string) http.HandlerFunc { + rp := &reverseproxy.ReverseProxy{ Director: func(req *http.Request) { req.URL.Scheme = "http" req.URL.Host = "api.moby.localhost" req.RequestURI = req.URL.String() }, Transport: &http.Transport{ - DialContext: dialDockerSocket, + DialContext: dialDockerSocket(socket), + DisableCompression: true, }, } @@ -41,7 +44,7 @@ func endpointNotAllowed(w http.ResponseWriter, _ *http.Request) { // ref: https://github.com/Tecnativa/docker-socket-proxy/blob/master/haproxy.cfg func NewHandler() http.Handler { r := mux.NewRouter() - socketHandler := DockerSocketHandler() + socketHandler := DockerSocketHandler(DockerSocket) const apiVersionPrefix = `/{version:(?:v[\d\.]+)?}` const containerPath = "/containers/{id:[a-zA-Z0-9_.-]+}" diff --git a/socket-proxy/pkg/handler_test.go b/socket-proxy/pkg/handler_test.go index 59748e4..4c4cc0a 100644 --- a/socket-proxy/pkg/handler_test.go +++ b/socket-proxy/pkg/handler_test.go @@ -9,7 +9,7 @@ import ( . "github.com/yusing/go-proxy/socketproxy/pkg" ) -func mockDockerSocketHandler() http.HandlerFunc { +func mockDockerSocketHandler(_ string) http.HandlerFunc { return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { w.WriteHeader(http.StatusOK) w.Write([]byte("mock docker response")) diff --git a/socket-proxy/pkg/reverseproxy/reverse_proxy.go b/socket-proxy/pkg/reverseproxy/reverse_proxy.go new file mode 100644 index 0000000..cfa3c3f --- /dev/null +++ b/socket-proxy/pkg/reverseproxy/reverse_proxy.go @@ -0,0 +1,600 @@ +// Copyright 2011 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. +// License URL: https://cs.opensource.google/go/go/+/master:LICENSE + +// HTTP reverse proxy handler + +package reverseproxy + +import ( + "context" + "errors" + "fmt" + "io" + "log" + "net" + "net/http" + "net/http/httptrace" + "net/textproto" + "net/url" + "strings" + "sync" + "time" + + "github.com/yusing/go-proxy/internal/utils" + "golang.org/x/net/http/httpguts" +) + +// A ProxyRequest contains a request to be rewritten by a [ReverseProxy]. +type ProxyRequest struct { + // In is the request received by the proxy. + // The Rewrite function must not modify In. + In *http.Request + + // Out is the request which will be sent by the proxy. + // The Rewrite function may modify or replace this request. + // Hop-by-hop headers are removed from this request + // before Rewrite is called. + Out *http.Request +} + +// SetURL routes the outbound request to the scheme, host, and base path +// provided in target. If the target's path is "/base" and the incoming +// request was for "/dir", the target request will be for "/base/dir". +// +// SetURL rewrites the outbound Host header to match the target's host. +// To preserve the inbound request's Host header (the default behavior +// of [NewSingleHostReverseProxy]): +// +// rewriteFunc := func(r *httputil.ProxyRequest) { +// r.SetURL(url) +// r.Out.Host = r.In.Host +// } +func (r *ProxyRequest) SetURL(target *url.URL) { + rewriteRequestURL(r.Out, target) + r.Out.Host = "" +} + +// SetXForwarded sets the X-Forwarded-For, X-Forwarded-Host, and +// X-Forwarded-Proto headers of the outbound request. +// +// - The X-Forwarded-For header is set to the client IP address. +// - The X-Forwarded-Host header is set to the host name requested +// by the client. +// - The X-Forwarded-Proto header is set to "http" or "https", depending +// on whether the inbound request was made on a TLS-enabled connection. +// +// If the outbound request contains an existing X-Forwarded-For header, +// SetXForwarded appends the client IP address to it. To append to the +// inbound request's X-Forwarded-For header (the default behavior of +// [ReverseProxy] when using a Director function), copy the header +// from the inbound request before calling SetXForwarded: +// +// rewriteFunc := func(r *httputil.ProxyRequest) { +// r.Out.Header["X-Forwarded-For"] = r.In.Header["X-Forwarded-For"] +// r.SetXForwarded() +// } +func (r *ProxyRequest) SetXForwarded() { + clientIP, _, err := net.SplitHostPort(r.In.RemoteAddr) + if err == nil { + prior := r.Out.Header["X-Forwarded-For"] + if len(prior) > 0 { + clientIP = strings.Join(prior, ", ") + ", " + clientIP + } + r.Out.Header.Set("X-Forwarded-For", clientIP) + } else { + r.Out.Header.Del("X-Forwarded-For") + } + r.Out.Header.Set("X-Forwarded-Host", r.In.Host) + if r.In.TLS == nil { + r.Out.Header.Set("X-Forwarded-Proto", "http") + } else { + r.Out.Header.Set("X-Forwarded-Proto", "https") + } +} + +// ReverseProxy is an HTTP Handler that takes an incoming request and +// sends it to another server, proxying the response back to the +// client. +// +// 1xx responses are forwarded to the client if the underlying +// transport supports ClientTrace.Got1xxResponse. +type ReverseProxy struct { + // Director is a function which modifies + // the request into a new request to be sent + // using Transport. Its response is then copied + // back to the original client unmodified. + // Director must not access the provided Request + // after returning. + // + // By default, the X-Forwarded-For header is set to the + // value of the client IP address. If an X-Forwarded-For + // header already exists, the client IP is appended to the + // existing values. As a special case, if the header + // exists in the Request.Header map but has a nil value + // (such as when set by the Director func), the X-Forwarded-For + // header is not modified. + // + // To prevent IP spoofing, be sure to delete any pre-existing + // X-Forwarded-For header coming from the client or + // an untrusted proxy. + // + // Hop-by-hop headers are removed from the request after + // Director returns, which can remove headers added by + // Director. Use a Rewrite function instead to ensure + // modifications to the request are preserved. + // + // Unparsable query parameters are removed from the outbound + // request if Request.Form is set after Director returns. + // + // At most one of Rewrite or Director may be set. + Director func(*http.Request) + + // The transport used to perform proxy requests. + // If nil, http.DefaultTransport is used. + Transport http.RoundTripper + + // FlushInterval specifies the flush interval + // to flush to the client while copying the + // response body. + // If zero, no periodic flushing is done. + // A negative value means to flush immediately + // after each write to the client. + // The FlushInterval is ignored when ReverseProxy + // recognizes a response as a streaming response, or + // if its ContentLength is -1; for such responses, writes + // are flushed to the client immediately. + FlushInterval time.Duration + + // ErrorLog specifies an optional logger for errors + // that occur when attempting to proxy the request. + // If nil, logging is done via the log package's standard logger. + ErrorLog *log.Logger + + // BufferPool optionally specifies a buffer pool to + // get byte slices for use by io.CopyBuffer when + // copying HTTP response bodies. + BufferPool BufferPool + + // ModifyResponse is an optional function that modifies the + // Response from the backend. It is called if the backend + // returns a response at all, with any HTTP status code. + // If the backend is unreachable, the optional ErrorHandler is + // called without any call to ModifyResponse. + // + // If ModifyResponse returns an error, ErrorHandler is called + // with its error value. If ErrorHandler is nil, its default + // implementation is used. + ModifyResponse func(*http.Response) error + + // ErrorHandler is an optional function that handles errors + // reaching the backend or errors from ModifyResponse. + // + // If nil, the default is to log the provided error and return + // a 502 Status Bad Gateway response. + ErrorHandler func(http.ResponseWriter, *http.Request, error) +} + +// A BufferPool is an interface for getting and returning temporary +// byte slices for use by [io.CopyBuffer]. +type BufferPool interface { + Get() []byte + Put([]byte) +} + +func singleJoiningSlash(a, b string) string { + aslash := strings.HasSuffix(a, "/") + bslash := strings.HasPrefix(b, "/") + switch { + case aslash && bslash: + return a + b[1:] + case !aslash && !bslash: + return a + "/" + b + } + return a + b +} + +func joinURLPath(a, b *url.URL) (path, rawpath string) { + if a.RawPath == "" && b.RawPath == "" { + return singleJoiningSlash(a.Path, b.Path), "" + } + // Same as singleJoiningSlash, but uses EscapedPath to determine + // whether a slash should be added + apath := a.EscapedPath() + bpath := b.EscapedPath() + + aslash := strings.HasSuffix(apath, "/") + bslash := strings.HasPrefix(bpath, "/") + + switch { + case aslash && bslash: + return a.Path + b.Path[1:], apath + bpath[1:] + case !aslash && !bslash: + return a.Path + "/" + b.Path, apath + "/" + bpath + } + return a.Path + b.Path, apath + bpath +} + +// NewSingleHostReverseProxy returns a new [ReverseProxy] that routes +// URLs to the scheme, host, and base path provided in target. If the +// target's path is "/base" and the incoming request was for "/dir", +// the target request will be for /base/dir. +// +// NewSingleHostReverseProxy does not rewrite the Host header. +// +// To customize the ReverseProxy behavior beyond what +// NewSingleHostReverseProxy provides, use ReverseProxy directly +// with a Rewrite function. The ProxyRequest SetURL method +// may be used to route the outbound request. (Note that SetURL, +// unlike NewSingleHostReverseProxy, rewrites the Host header +// of the outbound request by default.) +// +// proxy := &ReverseProxy{ +// Rewrite: func(r *ProxyRequest) { +// r.SetURL(target) +// r.Out.Host = r.In.Host // if desired +// }, +// } +func NewSingleHostReverseProxy(target *url.URL) *ReverseProxy { + director := func(req *http.Request) { + rewriteRequestURL(req, target) + } + return &ReverseProxy{Director: director} +} + +func rewriteRequestURL(req *http.Request, target *url.URL) { + targetQuery := target.RawQuery + req.URL.Scheme = target.Scheme + req.URL.Host = target.Host + req.URL.Path, req.URL.RawPath = joinURLPath(target, req.URL) + if targetQuery == "" || req.URL.RawQuery == "" { + req.URL.RawQuery = targetQuery + req.URL.RawQuery + } else { + req.URL.RawQuery = targetQuery + "&" + req.URL.RawQuery + } +} + +func copyHeader(dst, src http.Header) { + for k, vv := range src { + for _, v := range vv { + dst.Add(k, v) + } + } +} + +// Hop-by-hop headers. These are removed when sent to the backend. +// As of RFC 7230, hop-by-hop headers are required to appear in the +// Connection header field. These are the headers defined by the +// obsoleted RFC 2616 (section 13.5.1) and are used for backward +// compatibility. +var hopHeaders = []string{ + "Connection", + "Proxy-Connection", // non-standard but still sent by libcurl and rejected by e.g. google + "Keep-Alive", + "Proxy-Authenticate", + "Proxy-Authorization", + "Te", // canonicalized version of "TE" + "Trailer", // not Trailers per URL above; https://www.rfc-editor.org/errata_search.php?eid=4522 + "Transfer-Encoding", + "Upgrade", +} + +func (p *ReverseProxy) defaultErrorHandler(rw http.ResponseWriter, req *http.Request, err error) { + p.logf("http: proxy error: %v", err) + rw.WriteHeader(http.StatusBadGateway) +} + +func (p *ReverseProxy) getErrorHandler() func(http.ResponseWriter, *http.Request, error) { + if p.ErrorHandler != nil { + return p.ErrorHandler + } + return p.defaultErrorHandler +} + +// modifyResponse conditionally runs the optional ModifyResponse hook +// and reports whether the request should proceed. +func (p *ReverseProxy) modifyResponse(rw http.ResponseWriter, res *http.Response, req *http.Request) bool { + if p.ModifyResponse == nil { + return true + } + if err := p.ModifyResponse(res); err != nil { + res.Body.Close() + p.getErrorHandler()(rw, req, err) + return false + } + return true +} + +func (p *ReverseProxy) ServeHTTP(rw http.ResponseWriter, req *http.Request) { + transport := p.Transport + ctx := req.Context() + + outreq := req.Clone(ctx) + if req.ContentLength == 0 { + outreq.Body = nil // Issue 16036: nil Body for http.Transport retries + } + if outreq.Body != nil { + // Reading from the request body after returning from a handler is not + // allowed, and the RoundTrip goroutine that reads the Body can outlive + // this handler. This can lead to a crash if the handler panics (see + // Issue 46866). Although calling Close doesn't guarantee there isn't + // any Read in flight after the handle returns, in practice it's safe to + // read after closing it. + defer outreq.Body.Close() + } + if outreq.Header == nil { + outreq.Header = make(http.Header) // Issue 33142: historical behavior was to always allocate + } + + p.Director(outreq) + if outreq.Form != nil { + outreq.URL.RawQuery = cleanQueryParams(outreq.URL.RawQuery) + } + outreq.Close = false + + reqUpType := upgradeType(outreq.Header) + if !IsPrint(reqUpType) { + p.getErrorHandler()(rw, req, fmt.Errorf("client tried to switch to invalid protocol %q", reqUpType)) + return + } + removeHopByHopHeaders(outreq.Header) + + // Issue 21096: tell backend applications that care about trailer support + // that we support trailers. (We do, but we don't go out of our way to + // advertise that unless the incoming client request thought it was worth + // mentioning.) Note that we look at req.Header, not outreq.Header, since + // the latter has passed through removeHopByHopHeaders. + if httpguts.HeaderValuesContainsToken(req.Header["Te"], "trailers") { + outreq.Header.Set("Te", "trailers") + } + + if _, ok := outreq.Header["User-Agent"]; !ok { + // If the outbound request doesn't have a User-Agent header set, + // don't send the default Go HTTP client User-Agent. + outreq.Header.Set("User-Agent", "") + } + + var ( + roundTripMutex sync.Mutex + roundTripDone bool + ) + trace := &httptrace.ClientTrace{ + Got1xxResponse: func(code int, header textproto.MIMEHeader) error { + roundTripMutex.Lock() + defer roundTripMutex.Unlock() + if roundTripDone { + // If RoundTrip has returned, don't try to further modify + // the ResponseWriter's header map. + return nil + } + h := rw.Header() + copyHeader(h, http.Header(header)) + rw.WriteHeader(code) + + // Clear headers, it's not automatically done by ResponseWriter.WriteHeader() for 1xx responses + clear(h) + return nil + }, + } + outreq = outreq.WithContext(httptrace.WithClientTrace(outreq.Context(), trace)) + + res, err := transport.RoundTrip(outreq) + roundTripMutex.Lock() + roundTripDone = true + roundTripMutex.Unlock() + if err != nil { + p.getErrorHandler()(rw, outreq, err) + return + } + + // Deal with 101 Switching Protocols responses: (WebSocket, h2c, etc) + if res.StatusCode == http.StatusSwitchingProtocols { + if !p.modifyResponse(rw, res, outreq) { + return + } + p.handleUpgradeResponse(rw, outreq, res) + return + } + + removeHopByHopHeaders(res.Header) + + if !p.modifyResponse(rw, res, outreq) { + return + } + + copyHeader(rw.Header(), res.Header) + + // The "Trailer" header isn't included in the Transport's response, + // at least for *http.Transport. Build it up from Trailer. + announcedTrailers := len(res.Trailer) + if announcedTrailers > 0 { + trailerKeys := make([]string, 0, len(res.Trailer)) + for k := range res.Trailer { + trailerKeys = append(trailerKeys, k) + } + rw.Header().Add("Trailer", strings.Join(trailerKeys, ", ")) + } + + rw.WriteHeader(res.StatusCode) + + err = utils.CopyCloseWithContext(ctx, rw, res.Body) + if err != nil { + if !errors.Is(err, context.Canceled) { + p.getErrorHandler()(rw, req, err) + } + return + } + + if len(res.Trailer) > 0 { + // Force chunking if we saw a response trailer. + // This prevents net/http from calculating the length for short + // bodies and adding a Content-Length. + http.NewResponseController(rw).Flush() + } + + if len(res.Trailer) == announcedTrailers { + copyHeader(rw.Header(), res.Trailer) + return + } + + for k, vv := range res.Trailer { + k = http.TrailerPrefix + k + for _, v := range vv { + rw.Header().Add(k, v) + } + } +} + +// removeHopByHopHeaders removes hop-by-hop headers. +func removeHopByHopHeaders(h http.Header) { + // RFC 7230, section 6.1: Remove headers listed in the "Connection" header. + for _, f := range h["Connection"] { + for sf := range strings.SplitSeq(f, ",") { + if sf = textproto.TrimString(sf); sf != "" { + h.Del(sf) + } + } + } + // RFC 2616, section 13.5.1: Remove a set of known hop-by-hop headers. + // This behavior is superseded by the RFC 7230 Connection header, but + // preserve it for backwards compatibility. + for _, f := range hopHeaders { + h.Del(f) + } +} + +func (p *ReverseProxy) logf(format string, args ...any) { + if p.ErrorLog != nil { + p.ErrorLog.Printf(format, args...) + } else { + log.Printf(format, args...) + } +} + +func upgradeType(h http.Header) string { + if !httpguts.HeaderValuesContainsToken(h["Connection"], "Upgrade") { + return "" + } + return h.Get("Upgrade") +} + +func (p *ReverseProxy) handleUpgradeResponse(rw http.ResponseWriter, req *http.Request, res *http.Response) { + reqUpType := upgradeType(req.Header) + resUpType := upgradeType(res.Header) + if !IsPrint(resUpType) { // We know reqUpType is ASCII, it's checked by the caller. + p.getErrorHandler()(rw, req, fmt.Errorf("backend tried to switch to invalid protocol %q", resUpType)) + return + } + if !strings.EqualFold(reqUpType, resUpType) { + p.getErrorHandler()(rw, req, fmt.Errorf("backend tried to switch protocol %q when %q was requested", resUpType, reqUpType)) + return + } + + backConn, ok := res.Body.(io.ReadWriteCloser) + if !ok { + p.getErrorHandler()(rw, req, fmt.Errorf("internal error: 101 switching protocols response with non-writable body")) + return + } + + rc := http.NewResponseController(rw) + conn, brw, hijackErr := rc.Hijack() + if errors.Is(hijackErr, http.ErrNotSupported) { + p.getErrorHandler()(rw, req, fmt.Errorf("can't switch protocols using non-Hijacker ResponseWriter type %T", rw)) + return + } + + backConnCloseCh := make(chan bool) + go func() { + // Ensure that the cancellation of a request closes the backend. + // See issue https://golang.org/issue/35559. + select { + case <-req.Context().Done(): + case <-backConnCloseCh: + } + backConn.Close() + }() + defer close(backConnCloseCh) + + if hijackErr != nil { + p.getErrorHandler()(rw, req, fmt.Errorf("Hijack failed on protocol switch: %v", hijackErr)) + return + } + defer conn.Close() + + copyHeader(rw.Header(), res.Header) + + res.Header = rw.Header() + res.Body = nil // so res.Write only writes the headers; we have res.Body in backConn above + if err := res.Write(brw); err != nil { + p.getErrorHandler()(rw, req, fmt.Errorf("response write: %v", err)) + return + } + if err := brw.Flush(); err != nil { + p.getErrorHandler()(rw, req, fmt.Errorf("response flush: %v", err)) + return + } + errc := make(chan error, 1) + spc := switchProtocolCopier{user: conn, backend: backConn} + go spc.copyToBackend(errc) + go spc.copyFromBackend(errc) + <-errc +} + +// switchProtocolCopier exists so goroutines proxying data back and +// forth have nice names in stacks. +type switchProtocolCopier struct { + user, backend io.ReadWriter +} + +func (c switchProtocolCopier) copyFromBackend(errc chan<- error) { + _, err := io.Copy(c.user, c.backend) + errc <- err +} + +func (c switchProtocolCopier) copyToBackend(errc chan<- error) { + _, err := io.Copy(c.backend, c.user) + errc <- err +} + +func cleanQueryParams(s string) string { + reencode := func(s string) string { + v, _ := url.ParseQuery(s) + return v.Encode() + } + for i := 0; i < len(s); { + switch s[i] { + case ';': + return reencode(s) + case '%': + if i+2 >= len(s) || !ishex(s[i+1]) || !ishex(s[i+2]) { + return reencode(s) + } + i += 3 + default: + i++ + } + } + return s +} + +func ishex(c byte) bool { + switch { + case '0' <= c && c <= '9': + return true + case 'a' <= c && c <= 'f': + return true + case 'A' <= c && c <= 'F': + return true + } + return false +} + +func IsPrint(s string) bool { + for _, r := range s { + if r < ' ' || r > '~' { + return false + } + } + return true +}