;; Author: Tim Vaughan <tgvaughan@gmail.com>
;; Created: 11 April 2019
-;; Version: 2.3.5
+;; Version: 2.3.6
;; Keywords: comm gopher
;; Homepage: https://github.com/tgvaughan/elpher
;; Package-Requires: ((emacs "26"))
(require 'shr)
(require 'url-util)
(require 'subr-x)
+(require 'dns)
;;; Global constants
;;
-(defconst elpher-version "2.3.5"
+(defconst elpher-version "2.3.6"
"Current version of elpher.")
(defconst elpher-margin-width 6
allows switching from an encrypted channel back to plain text without user input."
:type '(boolean))
+(defcustom elpher-connection-timeout 5
+ "Specifies the number of seconds to wait for a network connection to time out."
+ :type '(integer))
;;; Model
;;
(url-host address))
(defun elpher-address-port (address)
- "Retrieve port from ADDRESS object."
+ "Retrieve port from ADDRESS object.
+If no address is defined, returns 0. (This is for compatibility with the URL library.)"
(if (symbolp address)
- nil)
- (if (> (url-port address) 0)
- (url-port address)
- (or (and (or (equal (url-type address) "gopher")
- (equal (url-type address) "gophers"))
- 70)
- (and (equal (url-type address) "gemini")
- 1965))))
+ 0
+ (url-port address)))
(defun elpher-address-special-p (address)
"Return non-nil if ADDRESS object is special (e.g. start page, bookmarks page)."
(defvar elpher-selector-string)
-(defun elpher-get-selector (address after &optional propagate-error)
- "Retrieve selector specified by ADDRESS, then execute AFTER.
-The result is stored as a string in the variable ‘elpher-selector-string’.
-
-Usually errors result in an error page being displayed. This is only
-appropriate if the selector is to be directly viewed. If PROPAGATE-ERROR
-is non-nil, this message is not displayed. Instead, the error propagates
-up to the calling function."
+(defun elpher-get-selector (address renderer &optional force-ipv4)
+ "Retrieve selector specified by ADDRESS, then render it using RENDERER.
+If FORCE-IPV4 is non-nil, explicitly look up and use IPv4 address corresponding
+to ADDRESS."
(setq elpher-selector-string "")
(when (equal (elpher-address-protocol address) "gophers")
(if (gnutls-available-p)
(error "Cannot retrieve TLS gopher selector: GnuTLS not available")))
(condition-case the-error
(let* ((kill-buffer-query-functions nil)
+ (port (elpher-address-port address))
+ (host (if force-ipv4
+ (dns-query (elpher-address-host address))
+ (elpher-address-host address)))
(proc (open-network-stream "elpher-process"
nil
- (elpher-address-host address)
- (elpher-address-port address)
- :type (if elpher-use-tls 'tls 'plain))))
+ host
+ (if (> port 0) port 70)
+ :type (if elpher-use-tls 'tls 'plain)
+ :nowait t))
+ (timer (run-at-time elpher-connection-timeout
+ nil
+ (lambda ()
+ (elpher-process-cleanup)
+ (unless force-ipv4
+ (elpher-get-selector address renderer t))))))
(set-process-coding-system proc 'binary)
(set-process-filter proc
(lambda (_proc string)
+ (cancel-timer timer)
(setq elpher-selector-string
(concat elpher-selector-string string))))
- (set-process-sentinel proc after)
+ (set-process-sentinel proc
+ (lambda (_proc event)
+ (unless (or (string-prefix-p "deleted" event)
+ (string-prefix-p "open" event))
+ (funcall renderer elpher-selector-string)
+ (elpher-restore-pos))))
+
(let ((inhibit-eol-conversion t))
(process-send-string proc
(concat (elpher-gopher-address-selector address) "\r\n"))))
(progn
(message "Disengaging TLS gopher mode.")
(setq elpher-use-tls nil)
- (elpher-get-selector address after))
+ (elpher-get-selector address renderer))
(elpher-process-cleanup)
- (if propagate-error
- (error the-error)
- (elpher-with-clean-buffer
- (insert (propertize "\n---- ERROR -----\n\n" 'face 'error)
- "Failed to connect to " (elpher-address-to-url address) ".\n"
- (propertize "\n----------------\n\n" 'face 'error)
- "Press 'u' to return to the previous page.")))))))
+ (elpher-network-error address the-error)))))
(defun elpher-get-gopher-node (renderer)
"Getter function for gopher nodes.
(elpher-restore-pos))
(elpher-with-clean-buffer
(insert "LOADING... (use 'u' to cancel)"))
- (elpher-get-selector address
- (lambda (_proc event)
- (unless (string-prefix-p "deleted" event)
- (funcall renderer elpher-selector-string)
- (elpher-restore-pos)))))))
+ (elpher-get-selector address renderer))))
;; Index rendering
(elpher-with-clean-buffer
(insert "LOADING RESULTS... (use 'u' to cancel)"))
- (elpher-get-selector search-address
- (lambda (_proc event)
- (unless (string-prefix-p "deleted" event)
- (funcall renderer elpher-selector-string)
- (elpher-restore-pos)))))
+ (elpher-get-selector search-address renderer))
(if aborted
(elpher-visit-parent-node))))))
;; Raw server response rendering
-(defun elpher-render-raw (data &optional _mime-type-string)
- "Display raw DATA in buffer. MIME-TYPE-STRING is unused."
+(defun elpher-render-raw (data &optional mime-type-string)
+ "Display raw DATA in buffer. MIME-TYPE-STRING is also displayed if provided."
(if (not data)
nil
(elpher-with-clean-buffer
+ (when mime-type-string
+ (insert "MIME type specified by server: '" mime-type-string "'\n"))
(insert data)
(goto-char (point-min)))
(message "Displaying raw server response. Reload or redraw to return to standard view.")))
;; Gemini node retrieval
(defvar elpher-gemini-response)
+(defvar elpher-gemini-redirect-chain)
-(defun elpher-get-gemini-response (address after)
- "Retrieve gemini ADDRESS, then execute AFTER.
-The response is stored in the variable ‘elpher-gemini-response’."
+(defun elpher-get-gemini-response (address renderer &optional force-ipv4)
+ "Retrieve gemini ADDRESS, then render using RENDERER.
+If FORCE-IPV4 is non-nil, explicitly look up and use IPv4 address corresponding
+to ADDRESS."
(setq elpher-gemini-response "")
(if (not (gnutls-available-p))
(error "Cannot establish gemini connection: GnuTLS not available")
(condition-case the-error
(let* ((kill-buffer-query-functions nil)
(network-security-level 'medium)
+ (port (elpher-address-port address))
+ (host (if force-ipv4
+ (dns-query (elpher-address-host address))
+ (elpher-address-host address)))
(proc (open-network-stream "elpher-process"
nil
- (elpher-address-host address)
- (elpher-address-port address)
- :type 'tls)))
+ host
+ (if (> port 0) port 1965)
+ :type 'tls
+ :nowait t))
+ (timer (run-at-time elpher-connection-timeout nil
+ (lambda ()
+ (elpher-process-cleanup)
+ (unless force-ipv4
+ ; Try again with IPv4
+ (elpher-get-gemini-response address renderer t))))))
(set-process-coding-system proc 'binary)
(set-process-filter proc
(lambda (_proc string)
+ (cancel-timer timer)
(setq elpher-gemini-response
(concat elpher-gemini-response string))))
- (set-process-sentinel proc after)
+ (set-process-sentinel proc
+ (lambda (proc event)
+ (cond
+ ((string-prefix-p "open" event)) ; do nothing
+ ((string-prefix-p "deleted" event)) ; do nothing
+ ((and (string-empty-p elpher-gemini-response)
+ (not force-ipv4))
+ ; Try again with IPv4
+ (elpher-get-gemini-response address renderer t))
+ (t
+ (funcall #'elpher-process-gemini-response
+ renderer)
+ (elpher-restore-pos)))))
(let ((inhibit-eol-conversion t))
- (process-send-string proc
- (concat (elpher-address-to-url address) "\r\n"))))
+ (process-send-string proc (concat (elpher-address-to-url address)
+ "\r\n"))))
(error
(error "Error initiating connection to server")))))
(let* ((query-string (read-string (concat response-meta ": ")))
(url (elpher-address-to-url (elpher-node-address elpher-current-node)))
(query-address (elpher-address-from-url (concat url "?" query-string))))
- (elpher-get-gemini-response query-address
- (lambda (_proc event)
- (unless (string-prefix-p "deleted" event)
- (funcall #'elpher-process-gemini-response
- renderer)
- (elpher-restore-pos))))))
+ (elpher-get-gemini-response query-address renderer)))
(?2 ; Normal response
- ;; (message response-header)
(funcall renderer response-body response-meta))
(?3 ; Redirect
(message "Following redirect to %s" response-meta)
+ (if (>= (length elpher-gemini-redirect-chain) 5)
+ (error "More than 5 consecutive redirects followed"))
(let ((redirect-address (elpher-address-from-gemini-url response-meta)))
- (elpher-get-gemini-response redirect-address
- (lambda (_proc event)
- (unless (string-prefix-p "deleted" event)
- (funcall #'elpher-process-gemini-response
- renderer)
- (elpher-restore-pos))))))
+ (if (member redirect-address elpher-gemini-redirect-chain)
+ (error "Redirect loop detected"))
+ (if (not (string= (elpher-address-protocol redirect-address)
+ "gemini"))
+ (error "Server tried to automatically redirect to non-gemini URL: %s"
+ response-meta))
+ (add-to-list 'elpher-gemini-redirect-chain redirect-address)
+ (elpher-get-gemini-response redirect-address renderer)))
(?4 ; Temporary failure
(error "Gemini server reports TEMPORARY FAILURE for this request: %s %s"
response-code response-meta))
(elpher-restore-pos))
(elpher-with-clean-buffer
(insert "LOADING GEMINI... (use 'u' to cancel)"))
- (elpher-get-gemini-response address
- (lambda (_proc event)
- (unless (string-prefix-p "deleted" event)
- (funcall #'elpher-process-gemini-response
- renderer)
- (elpher-restore-pos)))))
+ (setq elpher-gemini-redirect-chain nil)
+ (elpher-get-gemini-response address renderer))
(error
(elpher-network-error address the-error)))))
(pcase mime-type
((or "text/gemini" "")
(elpher-render-gemini-map body parameters))
+ ("text/html"
+ (elpher-render-html body))
((pred (string-prefix-p "text/"))
(elpher-render-gemini-plain-text body parameters))
((pred (string-prefix-p "image/"))
(host (elpher-address-host address))
(port (elpher-address-port address)))
(elpher-visit-parent-node)
- (telnet host port)))
+ (if (> port 0)
+ (telnet host port)
+ (telnet host))))
;; Start page node retrieval