X-Git-Url: https://thelambdalab.xyz/gitweb/index.cgi?p=rags.git;a=blobdiff_plain;f=rags.scm;h=febfd823f986ac4a36478c9c3904c16ad7a921db;hp=1ec9bf723d26e715dd0958cade6314d3f26b5b97;hb=HEAD;hpb=fd37c59f02d3f282ed288c162428c53e4d156e67

diff --git a/rags.scm b/rags.scm
index 1ec9bf7..febfd82 100644
--- a/rags.scm
+++ b/rags.scm
@@ -1,5 +1,11 @@
 ;; The Right-Awful Gemini Server
-;;
+;; 
+;; This is a gemini server in the spirit of the
+;; scratchy gopher server.  Just as for that server,
+;; rags uses runtime evaluation of embedded scheme
+;; expressions to provide dynamically generated content.
+;; 
+;; See the readme for details.
 
 (import (chicken io)
         (chicken port)
@@ -11,16 +17,28 @@
         (chicken process)
         (chicken process-context)
         (chicken process-context posix)
-        matchable srfi-13
+        (chicken gc)
+        matchable srfi-13 srfi-1
         uri-common tcp6 openssl)
 
 (define-record config
-  root-dir host port certfile keyfile uid gid) 
+  root-dir host port certfile keyfile uid gid blacklist blacklist-resp)
 
 (define file-types
   '(("gmi" "text/gemini" "charset=utf-8")
     ("txt" "text/plain" "charset=utf-8")
-    ("xml" "text/xml" "charset=utf-8")))
+    ("csv" "text/csv" "charset=utf-8")
+    ("html" "text/html" "charset=utf-8")
+    ("xml" "text/xml" "charset=utf-8")
+    ("pdf" "application/pdf")
+    ("zip" "application/zip")
+    ("jpg" "image/jpeg")
+    ("jpeg" "image/jpeg")
+    ("png" "image/png")
+    ("mp3" "audio/mpeg")))
+
+(define eval-env-file "eval-env.scm")
+(define eval-env (interaction-environment))
 
 (define (process-request config request-line)
   (let ((uri (uri-normalize-path-segments (absolute-uri request-line))))
@@ -35,33 +53,69 @@
       (fail-permanent "Path must be absolute."))
      ((not (document-available? config uri))
       (fail-permanent "Document not found."))
+     ((and (document-path-directory? config uri)
+           (uri-lacks-trailing-slash? uri))
+      (redirect-permanent (uri-with-trailing-slash uri)))
+     ((document-script? config uri)
+      (serve-script config uri))
      (else 
       (serve-document config uri)))))
 
 (define (fail-permanent reason)
   (print "50 " reason "\r"))
 
+(define (redirect-permanent new-uri)
+  (print "30 " (uri->string new-uri) "\r"))
+
+(define (serve-query prompt)
+  (print "10 " prompt "\r"))
+
+(define (uri-lacks-trailing-slash? uri)
+  (not (string-null? (last (uri-path uri)))))
+
+(define (uri-with-trailing-slash uri)
+  (update-uri uri path: (append (uri-path uri) '(""))))
+
 (define (document-available? config uri)
   (file-exists? (document-path config uri)))
 
+(define (document-script? config uri)
+  (let ((path (document-path config uri)))
+    (and (file-exists? path)
+         (file-executable? path)
+         (equal? (pathname-extension path) "scm"))))
+
+(define (document-path-directory? config uri)
+  (directory-exists? (document-path-raw config uri)))
+
+(define (document-path-raw config uri)
+  (let* ((crumbs (reverse (cons (config-root-dir config) (cdr (uri-path uri))))))
+    (make-pathname (reverse (cdr crumbs)) (car crumbs))))
+
 (define (document-path config uri)
-  (let* ((crumbs (reverse (cons (config-root-dir config) (cdr (uri-path uri)))))
-         (path (make-pathname (reverse (cdr crumbs)) (car crumbs))))
+  (let* ((path (document-path-raw config uri)))
     (if (directory-exists? path)
         (make-pathname path "index.gmi")
         path)))
+
+(define (ext->mime ext)
+  (let* ((mime-detected (assoc ext file-types)))
+    (cdr (if mime-detected
+             mime-detected
+             (assoc "txt" file-types)))))
+
+(define (serve-document-header mime)
+  (print "20 " (string-intersperse mime ";") "\r"))
     
 (define (serve-document config uri)
   (let* ((path (document-path config uri))
          (ext (pathname-extension path))
-         (mime-detected (assoc ext file-types))
-         (mime (if mime-detected mime-detected (assoc "txt" file-types)))
-         (mime-type (cadr mime)))
-    (print "20 " (string-intersperse (cdr mime) ";") "\r")
+         (mime (ext->mime ext)))
+    (serve-document-header mime)
     (cond 
      ((file-executable? path)
       (serve-text-dynamic path)) ; Binary-files can also be generated here, but the source is dynamic text
-     ((string-prefix? "text/" mime-type)
+     ((string-prefix? "text/" (car mime))
       (serve-text-plain path))
      (else (serve-binary path)))))
 
@@ -94,7 +148,7 @@
      (with-current-working-directory
       working-directory
       (lambda ()
-        (eval expression))))
+        (eval expression eval-env))))
     (('shell command)
      (with-current-working-directory
       working-directory
@@ -107,6 +161,15 @@
             (close-output-port out-port))))))
     (else (error "Unknown element type."))))
 
+(define (serve-script config uri)
+  ;; Scripts are responsible for the entire response, including header
+  (let* ((path (document-path config uri))
+         (proc (eval (with-input-from-file path read) eval-env)))
+    (with-current-working-directory
+     (pathname-directory (document-path config uri))
+     (lambda ()
+       (apply proc (list uri))))))
+
 (define (with-current-working-directory directory thunk)
   (let ((old-wd (current-directory))
         (result 'none))
@@ -131,13 +194,38 @@
          "Port: '" (config-port config) "'\n"
          "Root directory: '" (config-root-dir config) "'\n"
          "Cert file: '" (config-certfile config) "'\n"
-         "Key file: '" (config-keyfile config) "'\n"
-         "\n"
-         "Gemini server listening ...")
+         "Key file: '" (config-keyfile config) "'")
+
+  (if (config-blacklist config)
+      (print "Blacklist file: '" (config-blacklist config) "'"))
+  (if (config-blacklist-resp config)
+      (print "Blacklist responce file: '" (config-blacklist-resp config) "'"))
 
+  (print)
+
+  (print* "Dropping privilages ... ")
   (drop-privs config)
+  (print "done")
+
+  (print* "Setting up environment ... ")
+  (setup-env config)
+  (print "done")
+
+  (print "\nGemini server listening ...")
   (server-loop listener config))
 
+(define (setup-env config)
+  (with-current-working-directory
+   (config-root-dir config)
+   (lambda ()
+     (if (and (file-exists? eval-env-file) (file-readable? eval-env-file))
+         (with-input-from-file eval-env-file
+           (lambda ()
+             (let loop ((next-expr (read)))
+               (unless (eof-object? next-expr)
+                 (eval next-expr eval-env)
+                 (loop (read))))))))))
+
 (define (drop-privs config)
   (let ((uid (config-uid config))
         (gid (config-gid config)))
@@ -150,15 +238,33 @@
 (define (server-loop listener config)
   (let-values (((in-port out-port) (ssl-accept listener)))
     (let-values (((local-ip remote-ip) (tcp-addresses (ssl-port->tcp-port in-port))))
+      (print (conc "Memory statistics: " (memory-statistics)))
       (print "Accepted connection from " remote-ip
              " on " (seconds->string))
       (condition-case
-          (let ((request-line (read-line in-port)))
-            (print* "Serving request '" request-line "' ... ")
-            (with-output-to-port out-port
-              (lambda ()
-                (process-request config request-line)))
-            (print "done."))
+          (if (and (config-blacklist config)
+                   (member remote-ip
+                           (with-input-from-file
+                               (config-blacklist config)
+                             read)))
+              (begin
+                (print "Connection from blacklisted IP. Closing.")
+                (with-output-to-port out-port
+                  (lambda ()
+                    (serve-document-header (ext->mime "txt"))
+                    (print "Refusing to serve to IP " remote-ip ".\n")
+                    (when (config-blacklist-resp config)
+                      (print)
+                      (for-each print
+                                (with-input-from-file
+                                    (config-blacklist-resp config)
+                                  read-lines))))))
+              (let ((request-line (read-line in-port)))
+                (print* "Serving request '" request-line "' ... ")
+                (with-output-to-port out-port
+                  (lambda ()
+                    (process-request config request-line)))
+                (print "done.")))
         (o (exn)
            (print-error-message o))))
     (close-input-port in-port)
@@ -171,14 +277,19 @@
     (print "Usage:\n"
            progname " [-h/--help]\n"
            progname " [-p/--port PORT] [-u/--user UID] [-g/--group GID]\n"
-           indent-str " server-root-dir hostname certfile keyfile")))
+           indent-str " [-b/--blacklist FILE] [-r/--blacklist-resp RESPFILE]\n"
+           indent-str " server-root-dir hostname certfile keyfile\n"
+           "\n"
+           "The -b option can be used to specify a FILE containing a list of IP addresses\n"
+           "to block from the server. If a connection from a blocked address is served,\n"
+           "the response file RESPFILE is served instead, if this is provided.")))
 
 (define (main)
   (let* ((progname (pathname-file (car (argv))))
-         (config (make-config #f #f 1965 #f #f #f #f)))
-    (if (null? (cdr (argv)))
+         (config (make-config #f #f 1965 #f #f #f #f #f #f)))
+    (if (null? (command-line-arguments))
         (print-usage progname)
-        (let loop ((args (cdr (argv))))
+        (let loop ((args (command-line-arguments)))
           (let ((this-arg (car args))
                 (rest-args (cdr args)))
             (if (string-prefix? "-" this-arg)
@@ -198,6 +309,14 @@
                       (equal? this-arg "--group"))
                   (config-gid-set! config (string->number (car rest-args)))
                   (loop (cdr rest-args)))
+                 ((or (equal? this-arg "-b")
+                      (equal? this-arg "--blacklist"))
+                  (config-blacklist-set! config (car rest-args))
+                  (loop (cdr rest-args)))
+                 ((or (equal? this-arg "-r")
+                      (equal? this-arg "--blacklist-resp"))
+                  (config-blacklist-resp-set! config (car rest-args))
+                  (loop (cdr rest-args)))
                  (else
                   (print-usage progname)))
                 (match args