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) { uip := getIPFromCtx(r.Context()) log.Printf("Request from %v :: %v %v\n", uip, r.Method, r.URL) if r.FormValue("q") != "" || r.FormValue("url") != "" { apiEndpointQuery(w, r) return } w.Header().Set("Content-Type", htmlutf8) n, err := w.Write([]byte(r.URL.String())) 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) } }