From 747f4fb70ff61d3f8a7bb1bed896a913b0999450 Mon Sep 17 00:00:00 2001 From: Ben Morrison Date: Sun, 19 May 2019 23:45:48 -0400 Subject: middleware func to attach remote ip to context --- http.go | 215 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 215 insertions(+) create mode 100644 http.go (limited to 'http.go') diff --git a/http.go b/http.go new file mode 100644 index 0000000..52f9923 --- /dev/null +++ b/http.go @@ -0,0 +1,215 @@ +package main + +import ( + "context" + "crypto/sha256" + "fmt" + "io/ioutil" + "log" + "net/http" + "os" + "strings" + "time" + + "github.com/gorilla/mux" +) + +// Attaches a request's IP address to the request's context +func newCtxUserIP(ctx context.Context, r *http.Request) context.Context { + base := strings.Split(r.RemoteAddr, ":") + uip := base[0] + return context.WithValue(ctx, ctxKey, uip) +} + +// Retrieves a request's IP address from the request's context +func getIPFromCtx(ctx context.Context) string { + uip, ok := ctx.Value(ctxKey).(string) + if !ok { + log.Printf("Couldn't retrieve IP from request\n") + } + return uip +} + +// Shim function to modify/pass context value to a handler +func ipMiddleware(hop http.Handler) http.Handler { + return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { + ctx := newCtxUserIP(r.Context(), r) + hop.ServeHTTP(w, r.WithContext(ctx)) + }) +} + +// handles "/" +func indexHandler(w http.ResponseWriter, r *http.Request) { + uip := getIPFromCtx(r.Context()) + log.Printf("Request from %v :: %v %v\n", uip, r.Method, r.URL) + + // Stat the index template to get the mod time + var etag string + if indextmpl, err := os.Stat("assets/tmpl/index.html"); err != nil { + log.Printf("Couldn't stat index template for ETag ... %v\n", err) + } else { + etag = fmt.Sprintf("%x", sha256.Sum256([]byte(indextmpl.ModTime().String()))) + } + + // Take the hex-encoded sha256 sum of the index template's mod time + // to send as an ETag. If an error occured when grabbing the file info, + // the ETag will be empty. + w.Header().Set("ETag", "\""+etag+"\"") + w.Header().Set("Content-Type", htmlutf8) + + // Pass the confObj.Instance data to the template, + // then send it to the client. + err := tmpls.ExecuteTemplate(w, "index.html", confObj.Instance) + if err != nil { + log.Printf("500: Error writing to HTTP stream: %v, %v %v via %v\n", err, r.Method, r.URL, uip) + http.Error(w, err.Error(), http.StatusInternalServerError) + return + } + +} + +// handles "/api" +func apiBaseHandler(w http.ResponseWriter, r *http.Request) { + uip := getIPFromCtx(r.Context()) + log.Printf("Request from %v :: %v %v\n", uip, r.Method, r.URL) + + timerfc3339, err := time.Now().MarshalText() + if err != nil { + log.Printf("Couldn't format time as RFC3339: %v\n", err) + } + etag := fmt.Sprintf("%x", sha256.Sum256(timerfc3339)) + w.Header().Set("ETag", etag) + w.Header().Set("Content-Type", txtutf8) + pathdata := []byte("\n\n" + r.URL.Path) + timerfc3339 = append(timerfc3339, pathdata...) + n, err := w.Write(timerfc3339) + if err != nil || n == 0 { + log.Printf("500: Error writing to HTTP stream: %v, %v %v via %v\n", err, r.Method, r.URL, uip) + http.Error(w, err.Error(), http.StatusInternalServerError) + } +} + +// handles "/api/plain" +// maybe add json/xml support later +func apiFormatHandler(w http.ResponseWriter, r *http.Request) { + uip := getIPFromCtx(r.Context()) + log.Printf("Request from %v :: %v %v\n", uip, r.Method, r.URL) + + vars := mux.Vars(r) + format := vars["format"] + + w.Header().Set("Content-Type", txtutf8) + n, err := w.Write([]byte(format + "\n")) + if err != nil || n == 0 { + log.Printf("500: Error writing to HTTP stream: %v, %v %v via %v\n", err, r.Method, r.URL, uip) + http.Error(w, err.Error(), http.StatusInternalServerError) + } +} + +// handles "/api/plain/(users|mentions|tweets)" +func apiEndpointHandler(w http.ResponseWriter, r *http.Request) { + vars := mux.Vars(r) + format := vars["format"] + endpoint := vars["endpoint"] + + uip := getIPFromCtx(r.Context()) + log.Printf("Request from %v :: %v %v\n", uip, r.Method, r.URL) + + w.Header().Set("Content-Type", htmlutf8) + n, err := w.Write([]byte(format + "/" + endpoint)) + if err != nil || n == 0 { + log.Printf("500: Error writing to HTTP stream: %v, %v %v via %v\n", err, r.Method, r.URL, uip) + http.Error(w, err.Error(), http.StatusInternalServerError) + } + +} + +// handles POST for "/api/plain/users" +func apiEndpointPOSTHandler(w http.ResponseWriter, r *http.Request) { + vars := mux.Vars(r) + format := vars["format"] + endpoint := vars["endpoint"] + + uip := getIPFromCtx(r.Context()) + log.Printf("Request from %v :: %v %v\n", uip, r.Method, r.URL) + + w.Header().Set("Content-Type", htmlutf8) + n, err := w.Write([]byte(format + "/" + endpoint)) + if err != nil || n == 0 { + log.Printf("500: Error writing to HTTP stream: %v, %v %v via %v\n", err, r.Method, r.URL, uip) + http.Error(w, err.Error(), http.StatusInternalServerError) + } + +} + +// handles "/api/plain/tags" +func apiTagsBaseHandler(w http.ResponseWriter, r *http.Request) { + vars := mux.Vars(r) + format := vars["format"] + + uip := getIPFromCtx(r.Context()) + log.Printf("Request from %v :: %v %v\n", uip, r.Method, r.URL) + + w.Header().Set("Content-Type", htmlutf8) + n, err := w.Write([]byte("api/" + format + "/tags")) + if err != nil || n == 0 { + log.Printf("500: Error writing to HTTP stream: %v, %v %v via %v\n", err, r.Method, r.URL, uip) + http.Error(w, err.Error(), http.StatusInternalServerError) + } + +} + +// handles "/api/plain/tags/[a-zA-Z0-9]+" +func apiTagsHandler(w http.ResponseWriter, r *http.Request) { + vars := mux.Vars(r) + format := vars["format"] + tags := vars["tags"] + + uip := getIPFromCtx(r.Context()) + log.Printf("Request from %v :: %v %v\n", uip, r.Method, r.URL) + + w.Header().Set("Content-Type", htmlutf8) + n, err := w.Write([]byte("api/" + format + "/tags/" + tags)) + if err != nil || n == 0 { + log.Printf("500: Error writing to HTTP stream: %v, %v %v via %v\n", err, r.Method, r.URL, uip) + http.Error(w, err.Error(), http.StatusInternalServerError) + } + +} + +// Serving the stylesheet virtually because +// files aren't served directly. +func cssHandler(w http.ResponseWriter, r *http.Request) { + uip := getIPFromCtx(r.Context()) + log.Printf("Request from %v :: %v %v\n", uip, r.Method, r.URL) + + // read the raw bytes of the stylesheet + css, err := ioutil.ReadFile("assets/style.css") + if err != nil { + if os.IsNotExist(err) { + log.Printf("CSS file does not exist: /css request 404\n") + http.Error(w, err.Error(), http.StatusNotFound) + return + } + log.Printf("500: %v\n", err) + http.Error(w, err.Error(), http.StatusInternalServerError) + return + } + + // Get the mod time for the etag header + stat, err := os.Stat("assets/style.css") + if err != nil { + log.Printf("Couldn't stat CSS file to send ETag header: %v\n", err) + } + + // Sending the sha256 sum of the modtime in hexadecimal for the ETag header + etag := fmt.Sprintf("%x", sha256.Sum256([]byte(stat.ModTime().String()))) + + w.Header().Set("ETag", "\""+etag+"\"") + w.Header().Set("Content-Type", cssutf8) + n, err := w.Write(css) + if err != nil || n == 0 { + log.Printf("500: Error writing to HTTP stream: %v, %v %v via %v\n", err, r.Method, r.URL, uip) + http.Error(w, err.Error(), http.StatusInternalServerError) + } +} -- cgit 1.4.1-2-gfad0