From 5ef4673d1ea3ef8a5881831a80978a4a40f99dec Mon Sep 17 00:00:00 2001 From: Tim Vaughan Date: Fri, 25 Oct 2019 15:11:24 +0200 Subject: [PATCH] Accelerated IPv4 fallback working on gemini servers. --- elpher.el | 122 +++++++++++++++++++++++++++--------------------------- 1 file changed, 62 insertions(+), 60 deletions(-) diff --git a/elpher.el b/elpher.el index 08b2227..2a8e216 100644 --- a/elpher.el +++ b/elpher.el @@ -176,6 +176,9 @@ While enabling this may seem convenient, it is also potentially dangerous as it 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 ;; @@ -488,14 +491,10 @@ away CRs and any terminating period." (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) @@ -506,19 +505,34 @@ up to the calling function." (condition-case the-error (let* ((kill-buffer-query-functions nil) (port (elpher-address-port address)) - (host (elpher-address-host address)) + (host (if force-ipv4 + (dns-query (elpher-address-host address)) + (elpher-address-host address))) (proc (open-network-stream "elpher-process" nil host (if (> port 0) port 70) :type (if elpher-use-tls 'tls 'plain) - :nowait t))) + :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")))) @@ -531,15 +545,9 @@ up to the calling function." (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. @@ -553,12 +561,7 @@ once they are retrieved from the gopher server." (elpher-restore-pos)) (elpher-with-clean-buffer (insert "LOADING... (use 'u' to cancel)")) - (elpher-get-selector address - (lambda (_proc event) - (unless (or (string-prefix-p "deleted" event) - (string-prefix-p "open" event)) - (funcall renderer elpher-selector-string) - (elpher-restore-pos))))))) + (elpher-get-selector address renderer)))) ;; Index rendering @@ -720,11 +723,7 @@ The response is rendered using the rendering function RENDERER." (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)))))) @@ -778,9 +777,10 @@ The response is rendered using the rendering function RENDERER." (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") @@ -788,22 +788,43 @@ The response is stored in the variable ‘elpher-gemini-response’." (let* ((kill-buffer-query-functions nil) (network-security-level 'medium) (port (elpher-address-port address)) - (host (elpher-address-host address)) + (host (if force-ipv4 + (dns-query (elpher-address-host address)) + (elpher-address-host address))) (proc (open-network-stream "elpher-process" nil host (if (> port 0) port 1965) :type 'tls - :nowait t))) + :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"))))) @@ -838,15 +859,8 @@ The response is assumed to be in the variable `elpher-gemini-response'." (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 (or (string-prefix-p "deleted" event) - (string-prefix-p "open" 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) @@ -860,13 +874,7 @@ The response is assumed to be in the variable `elpher-gemini-response'." (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 - (lambda (_proc event) - (unless (or (string-prefix-p "deleted" event) - (string-prefix-p "open" event)) - (funcall #'elpher-process-gemini-response - renderer) - (elpher-restore-pos)))))) + (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)) @@ -893,13 +901,7 @@ The response is assumed to be in the variable `elpher-gemini-response'." (elpher-with-clean-buffer (insert "LOADING GEMINI... (use 'u' to cancel)")) (setq elpher-gemini-redirect-chain nil) - (elpher-get-gemini-response address - (lambda (_proc event) - (unless (or (string-prefix-p "deleted" event) - (string-prefix-p "open" event)) - (funcall #'elpher-process-gemini-response - renderer) - (elpher-restore-pos))))) + (elpher-get-gemini-response address renderer)) (error (elpher-network-error address the-error))))) -- 2.20.1