404

package writefreely import ( "fmt" "html/template" "net/http" "net/url" "runtime/debug" "strconv" "strings" "time" "github.com/gorilla/sessions" "github.com/writeas/impart" "github.com/writeas/web-core/log" "github.com/writeas/writefreely/page" ) type UserLevel int const ( UserLevelNone UserLevel = iota // user or not -- ignored UserLevelOptional // user or not -- object fetched if user UserLevelNoneRequired // non-user (required) UserLevelUser // user (required) ) type ( handlerFunc func(app *app, w http.ResponseWriter, r *http.Request) error userHandlerFunc func(app *app, u *User, w http.ResponseWriter, r *http.Request) error dataHandlerFunc func(app *app, w http.ResponseWriter, r *http.Request) ([]byte, string, error) authFunc func(app *app, r *http.Request) (*User, error) ) type Handler struct { errors *ErrorPages sessionStore *sessions.CookieStore app *app } // ErrorPages hold template HTML error pages for displaying errors to the user. // In each, there should be a defined template named "base". type ErrorPages struct { NotFound *template.Template Gone *template.Template InternalServerError *template.Template Blank *template.Template } // NewHandler returns a new Handler instance, using the given StaticPage data, // and saving alias to the application's CookieStore. func NewHandler(app *app) *Handler { h := &Handler{ errors: &ErrorPages{ NotFound: template.Must(template.New("").Parse("{{define \"base\"}}404

Not found.

{{end}}")), Gone: template.Must(template.New("").Parse("{{define \"base\"}}410

Gone.

{{end}}")), InternalServerError: template.Must(template.New("").Parse("{{define \"base\"}}500

Internal server error.

{{end}}")), Blank: template.Must(template.New("").Parse("{{define \"base\"}}{{.Title}}

{{end}}")), }, sessionStore: app.sessionStore, app: app, } return h } // SetErrorPages sets the given set of ErrorPages as templates for any errors // that come up. func (h *Handler) SetErrorPages(e *ErrorPages) { h.errors = e } // User handles requests made in the web application by the authenticated user. // This provides user-friendly HTML pages and actions that work in the browser. func (h *Handler) User(f userHandlerFunc) http.HandlerFunc { return func(w http.ResponseWriter, r *http.Request) { h.handleHTTPError(w, r, func() error { var status int start := time.Now() defer func() { if e := recover(); e != nil { log.Error("%s: %s", e, debug.Stack()) h.errors.InternalServerError.ExecuteTemplate(w, "base", pageForReq(h.app, r)) status = http.StatusInternalServerError } log.Info("\"%s %s\" %d %s \"%s\" \"%s\"", r.Method, r.RequestURI, status, time.Since(start), r.UserAgent(), r.Host) }() u := getUserSession(h.app, r) if u == nil { err := ErrNotLoggedIn status = err.Status return err } err := f(h.app, u, w, r) if err == nil { status = http.StatusOK } else if err, ok := err.(impart.HTTPError); ok { status = err.Status } else { status = http.StatusInternalServerError } return err }()) } } // UserAPI handles requests made in the API by the authenticated user. // This provides user-friendly HTML pages and actions that work in the browser. func (h *Handler) UserAPI(f userHandlerFunc) http.HandlerFunc { return h.UserAll(false, f, func(app *app, r *http.Request) (*User, error) { // Authorize user from Authorization header t := r.Header.Get("Authorization") if t == "" { return nil, ErrNoAccessToken } u := &User{ID: app.db.GetUserID(t)} if u.ID == -1 { return nil, ErrBadAccessToken } return u, nil }) } func (h *Handler) UserAll(web bool, f userHandlerFunc, a authFunc) http.HandlerFunc { return func(w http.ResponseWriter, r *http.Request) { handleFunc := func() error { var status int start := time.Now() defer func() { if e := recover(); e != nil { log.Error("%s: %s", e, debug.Stack()) impart.WriteError(w, impart.HTTPError{http.StatusInternalServerError, "Something didn't work quite right."}) status = 500 } log.Info("\"%s %s\" %d %s \"%s\" \"%s\"", r.Method, r.RequestURI, status, time.Since(start), r.UserAgent(), r.Host) }() u, err := a(h.app, r) if err != nil { if err, ok := err.(impart.HTTPError); ok { status = err.Status } else { status = 500 } return err } err = f(h.app, u, w, r) if err == nil { status = 200 } else if err, ok := err.(impart.HTTPError); ok { status = err.Status } else { status = 500 } return err } if web { h.handleHTTPError(w, r, handleFunc()) } else { h.handleError(w, r, handleFunc()) } } } func (h *Handler) RedirectOnErr(f handlerFunc, loc string) handlerFunc { return func(app *app, w http.ResponseWriter, r *http.Request) error { err := f(app, w, r) if err != nil { if ie, ok := err.(impart.HTTPError); ok { // Override default redirect with returned error's, if it's a // redirect error. if ie.Status == http.StatusFound { return ie } } return impart.HTTPError{http.StatusFound, loc} } return nil } } func (h *Handler) Page(n string) http.HandlerFunc { return h.Web(func(app *app, w http.ResponseWriter, r *http.Request) error { t, ok := pages[n] if !ok { return impart.HTTPError{http.StatusNotFound, "Page not found."} } sp := pageForReq(app, r) err := t.ExecuteTemplate(w, "base", sp) if err != nil { log.Error("Unable to render page: %v", err) } return err }, UserLevelOptional) } func (h *Handler) WebErrors(f handlerFunc, ul UserLevel) http.HandlerFunc { return func(w http.ResponseWriter, r *http.Request) { // TODO: factor out this logic shared with Web() h.handleHTTPError(w, r, func() error { var status int start := time.Now() defer func() { if e := recover(); e != nil { u := getUserSession(h.app, r) username := "None" if u != nil { username = u.Username } log.Error("User: %s\n\n%s: %s", username, e, debug.Stack()) h.errors.InternalServerError.ExecuteTemplate(w, "base", pageForReq(h.app, r)) status = 500 } log.Info("\"%s %s\" %d %s \"%s\" \"%s\"", r.Method, r.RequestURI, status, time.Since(start), r.UserAgent(), r.Host) }() var session *sessions.Session var err error if ul != UserLevelNone { session, err = h.sessionStore.Get(r, cookieName) if err != nil && (ul == UserLevelNoneRequired || ul == UserLevelUser) { // Cookie is required, but we can ignore this error log.Error("Handler: Unable to get session (for user permission %d); ignoring: %v", ul, err) } _, gotUser := session.Values[cookieUserVal].(*User) if ul == UserLevelNoneRequired && gotUser { to := correctPageFromLoginAttempt(r) log.Info("Handler: Required NO user, but got one. Redirecting to %s", to) err := impart.HTTPError{http.StatusFound, to} status = err.Status return err } else if ul == UserLevelUser && !gotUser { log.Info("Handler: Required a user, but DIDN'T get one. Sending not logged in.") err := ErrNotLoggedIn status = err.Status return err } } // TODO: pass User object to function err = f(h.app, w, r) if err == nil { status = 200 } else if httpErr, ok := err.(impart.HTTPError); ok { status = httpErr.Status if status < 300 || status > 399 { addSessionFlash(h.app, w, r, httpErr.Message, session) return impart.HTTPError{http.StatusFound, r.Referer()} } } else { e := fmt.Sprintf("[Web handler] 500: %v", err) if !strings.HasSuffix(e, "write: broken pipe") { log.Error(e) } else { log.Error(e) } log.Info("Web handler internal error render") h.errors.InternalServerError.ExecuteTemplate(w, "base", pageForReq(h.app, r)) status = 500 } return err }()) } } // Web handles requests made in the web application. This provides user- // friendly HTML pages and actions that work in the browser. func (h *Handler) Web(f handlerFunc, ul UserLevel) http.HandlerFunc { return func(w http.ResponseWriter, r *http.Request) { h.handleHTTPError(w, r, func() error { var status int start := time.Now() defer func() { if e := recover(); e != nil { u := getUserSession(h.app, r) username := "None" if u != nil { username = u.Username } log.Error("User: %s\n\n%s: %s", username, e, debug.Stack()) log.Info("Web deferred internal error render") h.errors.InternalServerError.ExecuteTemplate(w, "base", pageForReq(h.app, r)) status = 500 } log.Info("\"%s %s\" %d %s \"%s\" \"%s\"", r.Method, r.RequestURI, status, time.Since(start), r.UserAgent(), r.Host) }() if ul != UserLevelNone { session, err := h.sessionStore.Get(r, cookieName) if err != nil && (ul == UserLevelNoneRequired || ul == UserLevelUser) { // Cookie is required, but we can ignore this error log.Error("Handler: Unable to get session (for user permission %d); ignoring: %v", ul, err) } _, gotUser := session.Values[cookieUserVal].(*User) if ul == UserLevelNoneRequired && gotUser { to := correctPageFromLoginAttempt(r) log.Info("Handler: Required NO user, but got one. Redirecting to %s", to) err := impart.HTTPError{http.StatusFound, to} status = err.Status return err } else if ul == UserLevelUser && !gotUser { log.Info("Handler: Required a user, but DIDN'T get one. Sending not logged in.") err := ErrNotLoggedIn status = err.Status return err } } // TODO: pass User object to function err := f(h.app, w, r) if err == nil { status = 200 } else if httpErr, ok := err.(impart.HTTPError); ok { status = httpErr.Status } else { e := fmt.Sprintf("[Web handler] 500: %v", err) log.Error(e) log.Info("Web internal error render") h.errors.InternalServerError.ExecuteTemplate(w, "base", pageForReq(h.app, r)) status = 500 } return err }()) } } func (h *Handler) All(f handlerFunc) http.HandlerFunc { return func(w http.ResponseWriter, r *http.Request) { h.handleError(w, r, func() error { // TODO: return correct "success" status status := 200 start := time.Now() defer func() { if e := recover(); e != nil { log.Error("%s:\n%s", e, debug.Stack()) impart.WriteError(w, impart.HTTPError{http.StatusInternalServerError, "Something didn't work quite right."}) status = 500 } log.Info("\"%s %s\" %d %s \"%s\" \"%s\"", r.Method, r.RequestURI, status, time.Since(start), r.UserAgent(), r.Host) }() // TODO: do any needed authentication err := f(h.app, w, r) if err != nil { if err, ok := err.(impart.HTTPError); ok { status = err.Status } else { status = 500 } } return err }()) } } func (h *Handler) Download(f dataHandlerFunc, ul UserLevel) http.HandlerFunc { return func(w http.ResponseWriter, r *http.Request) { h.handleHTTPError(w, r, func() error { var status int start := time.Now() defer func() { if e := recover(); e != nil { log.Error("%s: %s", e, debug.Stack()) h.errors.InternalServerError.ExecuteTemplate(w, "base", pageForReq(h.app, r)) status = 500 } log.Info("\"%s %s\" %d %s \"%s\" \"%s\"", r.Method, r.RequestURI, status, time.Since(start), r.UserAgent(), r.Host) }() data, filename, err := f(h.app, w, r) if err != nil { if err, ok := err.(impart.HTTPError); ok { status = err.Status } else { status = 500 } return err } ext := ".json" ct := "application/json" if strings.HasSuffix(r.URL.Path, ".csv") { ext = ".csv" ct = "text/csv" } else if strings.HasSuffix(r.URL.Path, ".zip") { ext = ".zip" ct = "application/zip" } w.Header().Set("Content-Disposition", fmt.Sprintf("attachment; filename=%s%s", filename, ext)) w.Header().Set("Content-Type", ct) w.Header().Set("Content-Length", strconv.Itoa(len(data))) fmt.Fprint(w, string(data)) status = 200 return nil }()) } } func (h *Handler) Redirect(url string, ul UserLevel) http.HandlerFunc { return func(w http.ResponseWriter, r *http.Request) { h.handleHTTPError(w, r, func() error { start := time.Now() var status int if ul != UserLevelNone { session, err := h.sessionStore.Get(r, cookieName) if err != nil && (ul == UserLevelNoneRequired || ul == UserLevelUser) { // Cookie is required, but we can ignore this error log.Error("Handler: Unable to get session (for user permission %d); ignoring: %v", ul, err) } _, gotUser := session.Values[cookieUserVal].(*User) if ul == UserLevelNoneRequired && gotUser { to := correctPageFromLoginAttempt(r) log.Info("Handler: Required NO user, but got one. Redirecting to %s", to) err := impart.HTTPError{http.StatusFound, to} status = err.Status return err } else if ul == UserLevelUser && !gotUser { log.Info("Handler: Required a user, but DIDN'T get one. Sending not logged in.") err := ErrNotLoggedIn status = err.Status return err } } status = sendRedirect(w, http.StatusFound, url) log.Info("\"%s %s\" %d %s \"%s\" \"%s\"", r.Method, r.RequestURI, status, time.Since(start), r.UserAgent(), r.Host) return nil }()) } } func (h *Handler) handleHTTPError(w http.ResponseWriter, r *http.Request, err error) { if err == nil { return } if err, ok := err.(impart.HTTPError); ok { if err.Status >= 300 && err.Status < 400 { sendRedirect(w, err.Status, err.Message) return } else if err.Status == http.StatusUnauthorized { q := "" if r.URL.RawQuery != "" { q = url.QueryEscape("?" + r.URL.RawQuery) } sendRedirect(w, http.StatusFound, "/login?to="+r.URL.Path+q) return } else if err.Status == http.StatusGone { p := &struct { page.StaticPage Content *template.HTML }{ StaticPage: pageForReq(h.app, r), } if err.Message != "" { co := template.HTML(err.Message) p.Content = &co } h.errors.Gone.ExecuteTemplate(w, "base", p) return } else if err.Status == http.StatusNotFound { h.errors.NotFound.ExecuteTemplate(w, "base", pageForReq(h.app, r)) return } else if err.Status == http.StatusInternalServerError { log.Info("handleHTTPErorr internal error render") h.errors.InternalServerError.ExecuteTemplate(w, "base", pageForReq(h.app, r)) return } else if err.Status == http.StatusAccepted { impart.WriteSuccess(w, "", err.Status) return } else { p := &struct { page.StaticPage Title string Content template.HTML }{ pageForReq(h.app, r), fmt.Sprintf("Uh oh (%d)", err.Status), template.HTML(fmt.Sprintf("

", err.Message)), } h.errors.Blank.ExecuteTemplate(w, "base", p) return } impart.WriteError(w, err) return } impart.WriteError(w, impart.HTTPError{http.StatusInternalServerError, "This is an unhelpful error message for a miscellaneous internal error."}) } func (h *Handler) handleError(w http.ResponseWriter, r *http.Request, err error) { if err == nil { return } if err, ok := err.(impart.HTTPError); ok { if err.Status >= 300 && err.Status < 400 { sendRedirect(w, err.Status, err.Message) return } // if strings.Contains(r.Header.Get("Accept"), "text/html") { impart.WriteError(w, err) // } return } if IsJSON(r.Header.Get("Content-Type")) { impart.WriteError(w, impart.HTTPError{http.StatusInternalServerError, "This is an unhelpful error message for a miscellaneous internal error."}) return } h.errors.InternalServerError.ExecuteTemplate(w, "base", pageForReq(h.app, r)) } func correctPageFromLoginAttempt(r *http.Request) string { to := r.FormValue("to") if to == "" { to = "/" } else if !strings.HasPrefix(to, "/") { to = "/" + to } return to } func (h *Handler) LogHandlerFunc(f http.HandlerFunc) http.HandlerFunc { return func(w http.ResponseWriter, r *http.Request) { h.handleHTTPError(w, r, func() error { status := 200 start := time.Now() defer func() { if e := recover(); e != nil { log.Error("Handler.LogHandlerFunc\n\n%s: %s", e, debug.Stack()) h.errors.InternalServerError.ExecuteTemplate(w, "base", pageForReq(h.app, r)) status = 500 } // TODO: log actual status code returned log.Info("\"%s %s\" %d %s \"%s\" \"%s\"", r.Method, r.RequestURI, status, time.Since(start), r.UserAgent(), r.Host) }() f(w, r) return nil }()) } } func sendRedirect(w http.ResponseWriter, code int, location string) int { w.Header().Set("Location", location) w.WriteHeader(code) return code }