-(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."
- (when (equal (elpher-address-protocol address) "gophers")
- (if (gnutls-available-p)
- (when (not elpher-use-tls)
- (setq elpher-use-tls t)
- (message "Engaging TLS gopher mode."))
- (error "Cannot retrieve TLS gopher selector: GnuTLS not available")))
- (unless (< (elpher-address-port address) 65536)
- (error "Cannot retrieve gopher selector: port number > 65536"))
- (condition-case nil
- (let* ((kill-buffer-query-functions nil)
- (port (elpher-address-port address))
- (host (elpher-address-host address))
- (selector-string-parts nil)
- (bytes-received 0)
- (hkbytes-received 0)
- (proc (open-network-stream "elpher-process"
- nil
- (if force-ipv4 (dns-query host) host)
- (if (> port 0) port 70)
- :type (if elpher-use-tls 'tls 'plain)
- :nowait t))
- (timer (run-at-time elpher-connection-timeout
- nil
- (lambda ()
- (pcase (process-status proc)
- ('failed
- (if (and (not (equal (elpher-address-protocol address)
- "gophers"))
- elpher-use-tls
- (or elpher-auto-disengage-TLS
- (yes-or-no-p "Could not establish encrypted connection. Disable TLS mode?")))
- (progn
- (message "Disabling TLS mode.")
- (setq elpher-use-tls nil)
- (elpher-get-selector address renderer))
- (elpher-network-error address "Could not establish encrypted connection")))
- ('connect
- (elpher-process-cleanup)
- (unless force-ipv4
- (message "Connection timed out. Retrying with IPv4 address.")
- (elpher-get-selector address renderer t))))))))
- (setq elpher-network-timer timer)
- (set-process-coding-system proc 'binary)
- (set-process-filter proc
- (lambda (_proc string)
- (when timer
- (cancel-timer timer)
- (setq timer nil))
- (setq bytes-received (+ bytes-received (length string)))
- (let ((new-hkbytes-received (/ bytes-received 102400)))
- (when (> new-hkbytes-received hkbytes-received)
- (setq hkbytes-received new-hkbytes-received)
- (with-current-buffer "*elpher*"
- (let ((inhibit-read-only t))
- (goto-char (point-min))
- (beginning-of-line 2)
- (delete-region (point) (point-max))
- (insert "("
- (number-to-string (/ hkbytes-received 10.0))
- " MB read)")))))
- (setq selector-string-parts
- (cons string selector-string-parts))))
- (set-process-sentinel proc
- (lambda (_proc event)
- (condition-case the-error
- (cond
- ((string-prefix-p "deleted" event))
- ((string-prefix-p "open" event)
- (let ((inhibit-eol-conversion t))
- (process-send-string
- proc
- (concat (elpher-gopher-address-selector address)
- "\r\n"))))
- (t
- (when timer
- (cancel-timer timer)
- (setq timer nil))
- (funcall renderer (apply #'concat
- (reverse selector-string-parts)))
- (elpher-restore-pos)))
- (error
- (elpher-network-error address the-error))))))
- (error
- (error "Error initiating connection to server"))))
+If non-nil, USE-TLS specifies that the connection is to be made over
+TLS. If set to gemini, the certificate verification will be disabled
+unless `elpher-gemini-TLS-cert-checks' is non-nil.
+
+If non-nil, FORCE-IPV4 causes the network connection to be made over
+ipv4 only. (The default behaviour when this is not set depends on
+the host operating system and the local network capabilities."
+ (if (and use-tls (not (gnutls-available-p)))
+ (error "Use of TLS requires Emacs to be compiled with GNU TLS support")
+ (unless (< (elpher-address-port address) 65536)
+ (error "Cannot establish network connection: port number > 65536"))
+ (when (and (eq use-tls 'gemini) (not elpher-gemini-TLS-cert-checks))
+ (setq-local network-security-level 'low))
+ (condition-case nil
+ (let* ((kill-buffer-query-functions nil)
+ (port (elpher-address-port address))
+ (host (elpher-address-host address))
+ (response-string-parts nil)
+ (bytes-received 0)
+ (hkbytes-received 0)
+ (proc (make-network-process :name "elpher-process"
+ :host host
+ :family (and force-ipv4 'ipv4)
+ :service (if (> port 0) port default-port)
+ :buffer nil
+ :coding 'binary
+ :noquery t
+ :nowait t
+ :tls-parameters
+ (and use-tls
+ (cons 'gnutls-x509pki
+ (gnutls-boot-parameters
+ :type 'gnutls-x509pki
+ :hostname host)))))
+ (timer (run-at-time elpher-connection-timeout nil
+ (lambda ()
+ (elpher-process-cleanup)
+ (cond
+ ; Try again with IPv4
+ ((not force-ipv4)
+ (message "Connection timed out. Retrying with IPv4.")
+ (elpher-get-host-response address default-port
+ query-string
+ response-processor
+ use-tls t))
+ ((and use-tls
+ (not (eq use-tls 'gemini))
+ (or elpher-auto-disengage-TLS
+ (y-or-n-p
+ "TLS connetion failed. Disable TLS mode and retry? ")))
+ (setq elpher-use-tls nil)
+ (elpher-get-host-response address default-port
+ query-string
+ response-processor
+ nil force-ipv4))
+ (t
+ (elpher-network-error address "Connection time-out.")))))))
+ (setq elpher-network-timer timer)
+ (elpher-buffer-message (concat "Connecting to " host "..."))
+ (set-process-filter proc
+ (lambda (_proc string)
+ (when timer
+ (cancel-timer timer)
+ (setq timer nil))
+ (setq bytes-received (+ bytes-received (length string)))
+ (let ((new-hkbytes-received (/ bytes-received 102400)))
+ (when (> new-hkbytes-received hkbytes-received)
+ (setq hkbytes-received new-hkbytes-received)
+ (elpher-buffer-message
+ (concat "("
+ (number-to-string (/ hkbytes-received 10.0))
+ " MB read)")
+ 1)))
+ (setq response-string-parts
+ (cons string response-string-parts))))
+ (set-process-sentinel proc
+ (lambda (proc event)
+ (when timer
+ (cancel-timer timer))
+ (condition-case the-error
+ (cond
+ ((string-prefix-p "open" event) ; request URL
+ (elpher-buffer-message
+ (concat "Connected to " host ". Receiving data..."))
+ (let ((inhibit-eol-conversion t))
+ (process-send-string proc query-string)))
+ ((string-prefix-p "deleted" event)) ; do nothing
+ ((and (not response-string-parts)
+ (not (or elpher-ipv4-always force-ipv4)))
+ ; Try again with IPv4
+ (message "Connection failed. Retrying with IPv4.")
+ (elpher-get-host-response address default-port
+ query-string
+ response-processor
+ use-tls t))
+ (response-string-parts
+ (elpher-with-clean-buffer
+ (insert "Data received. Rendering..."))
+ (funcall response-processor
+ (apply #'concat (reverse response-string-parts)))
+ (elpher-restore-pos))
+ (t
+ (error "No response from server")))
+ (error
+ (elpher-network-error address the-error))))))
+ (error
+ (error "Error initiating connection to server")))))
+
+
+
+;;; Gopher selector retrieval
+;;
+
+(defun elpher-get-gopher-response (address renderer)
+ "Get response string from gopher server at ADDRESS and render using RENDERER."
+ (elpher-get-host-response address 70
+ (concat (elpher-gopher-address-selector address) "\r\n")
+ renderer
+ (or (string= (elpher-address-protocol address) "gophers")
+ elpher-use-tls)))