1 ;; The Right-Awful Gemini Server
12 (chicken process-context)
14 uri-common tcp6 openssl)
17 root-dir host port certfile keyfile)
20 '(("gmi" "text/gemini" "charset=utf-8")
21 ("txt" "text/plain" "charset=utf-8")))
23 (define (process-request config request-line)
24 (let ((uri (uri-normalize-path-segments (absolute-uri request-line))))
26 ((not (eq? (uri-scheme uri) 'gemini))
27 (fail-permanent "Unsupported scheme."))
29 (fail-permanent "URL lacks host name."))
30 ((not (equal? (uri-host uri) (config-host config)))
31 (fail-permanent "Proxy requests forbidden."))
32 ((uri-path-relative? uri)
33 (fail-permanent "Path must be absolute."))
34 ((not (document-available? config uri))
35 (fail-permanent "Document not found."))
37 (serve-document config uri)))))
39 (define (fail-permanent reason)
40 (print "50 " reason "\r"))
42 (define (document-available? config uri)
43 (file-exists? (document-path config uri)))
45 (define (document-path config uri)
46 (let* ((crumbs (reverse (cons (config-root-dir config) (cdr (uri-path uri)))))
47 (path (make-pathname (reverse (cdr crumbs)) (car crumbs))))
48 (if (directory-exists? path)
49 (make-pathname path "index.gmi")
52 (define (serve-document config uri)
53 (let* ((path (document-path config uri))
54 (ext (pathname-extension path))
55 (mime-detected (assoc ext file-types))
56 (mime (if mime-detected mime-detected (assoc "txt" file-types)))
57 (mime-type (cadr mime)))
58 (print "20 " (string-intersperse (cdr mime) ";") "\r")
60 ((and (equal? mime-type "text/gemini")
61 (file-executable? path))
62 (serve-text-dynamic path))
63 ((string-prefix? "text/" mime-type)
64 (serve-text-plain path))
65 (else (serve-binary path)))))
67 (define (serve-text-plain path)
68 (with-input-from-file path
70 (let loop ((str (read-string)))
71 (unless (eof-object? str)
73 (loop (read-string)))))))
75 (define (serve-text-dynamic path)
76 (with-input-from-file path
78 (let loop ((c (peek-char)))
85 (serve-dynamic-element (read) (pathname-directory path))
88 (loop (peek-char))))))))
90 (define (serve-dynamic-element element working-directory)
93 (with-current-working-directory
98 (with-current-working-directory
101 (let-values (((in-port out-port id) (process command)))
102 (let ((string (read-string #f in-port)))
103 (unless (eof-object? string)
105 (close-input-port in-port)
106 (close-output-port out-port))))))
107 (else (error "Unknown element type."))))
109 (define (with-current-working-directory directory thunk)
110 (let ((old-wd (current-directory))
114 (change-directory directory)
115 (set! result (thunk))
116 (change-directory old-wd)
119 (change-directory old-wd)
122 (define (run-server config)
123 (define listener (ssl-listen* hostname: (config-host config)
124 port: (config-port config)
125 certificate: (config-certfile config)
126 private-key: (config-keyfile config)))
128 (print "Host: '" (config-host config) "'\n"
129 "Port: '" (config-port config) "'\n"
130 "Root directory: '" (config-root-dir config) "'\n"
131 "Cert file: '" (config-certfile config) "'\n"
132 "Key file: '" (config-keyfile config) "'\n"
134 "Gemini server listening ...")
136 (server-loop listener config))
138 (define (server-loop listener config)
139 (let-values (((in-port out-port) (ssl-accept listener)))
140 (let-values (((local-ip remote-ip) (tcp-addresses (ssl-port->tcp-port in-port))))
141 (print "Accepted connection from " remote-ip
142 " on " (seconds->string))
144 (let ((request-line (read-line in-port)))
145 (print* "Serving request '" request-line "' ... ")
146 (with-output-to-port out-port
148 (process-request config request-line)))
151 (print-error-message o))))
152 (close-input-port in-port)
153 (close-output-port out-port))
154 (server-loop listener config))
157 (define (print-usage progname)
158 (print "Usage: " progname " [-h] [-p port] server-root-dir hostname certfile keyfile"))
161 (let* ((progname (pathname-file (car (argv))))
162 (config (make-config #f #f 1965 #f #f)))
163 (if (null? (cdr (argv)))
164 (print-usage progname)
165 (let loop ((args (cdr (argv))))
166 (let ((this-arg (car args))
167 (rest-args (cdr args)))
168 (if (string-prefix? "-" this-arg)
170 ((or (equal? this-arg "-h")
171 (equal? this-arg "--help"))
172 (print-usage progname))
173 ((or (equal? this-arg "-p")
174 (equal? this-arg "--port"))
175 (config-port-set! config (string->bumber (car rest-args)))
176 (loop (cdr rest-args)))
178 (print-usage progname)))
180 ((root-dir host certfile keyfile)
181 (config-root-dir-set! config root-dir)
182 (config-host-set! config host)
183 (config-certfile-set! config certfile)
184 (config-keyfile-set! config keyfile)
187 (print "One or more invalid arguments.")
188 (print-usage progname)))))))))