From 4ba0d882b96212e079552db8ccc9a506edcad842 Mon Sep 17 00:00:00 2001
From: Christopher Brannon <chris@the-brannons.com>
Date: Thu, 25 Mar 2021 14:50:35 -0700
Subject: [PATCH] Support name-based virtual hosting.

Instead of putting content directly under server-root, it now should
go under server-root/HOSTNAME.  E.G., /srv/gemini/the-brannons.com/ for my public capsule.
---
 rags.scm | 29 +++++++++++++++++++++--------
 1 file changed, 21 insertions(+), 8 deletions(-)

diff --git a/rags.scm b/rags.scm
index ef4726f..8fb1bd9 100644
--- a/rags.scm
+++ b/rags.scm
@@ -8,6 +8,7 @@
 ;; See the readme for details.
 
 (import (chicken io)
+        (chicken irregex)
         (chicken port)
         (chicken file)
         (chicken string)
@@ -21,7 +22,7 @@
         uri-common tcp6 openssl)
 
 (define-record config
-  root-dir host port certfile keyfile uid gid) 
+  root-dir port certfile keyfile uid gid) 
 
 (define file-types
   '(("gmi" "text/gemini" "charset=utf-8")
@@ -43,7 +44,9 @@
       (fail-permanent "Unsupported scheme."))
      ((not (uri-host uri))
       (fail-permanent "URL lacks host name."))
-     ((not (equal? (uri-host uri) (config-host config)))
+     ((not (valid-hostname (uri-host uri)))
+      (fail-permanent "Invalid host name."))
+     ((not (existing-host config uri))
       (fail-permanent "Proxy requests forbidden."))
      ((uri-path-relative? uri)
       (fail-permanent "Path must be absolute."))
@@ -72,6 +75,16 @@
 (define (uri-with-trailing-slash uri)
   (update-uri uri path: (append (uri-path uri) '(""))))
 
+(define (valid-hostname name)
+  (let*
+    ((host-label-part '(+ (or alphanumeric #\- #\_)))
+      (domain-part `(: #\. ,host-label-part))
+      (hostname-regex `(: ,host-label-part (+ ,domain-part))))
+    (irregex-match? hostname-regex name)))
+
+(define (existing-host config uri)
+  (directory-exists? (make-pathname (config-root-dir config) (uri-host uri))))
+
 (define (document-available? config uri)
   (file-exists? (document-path config uri)))
 
@@ -85,7 +98,8 @@
   (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))))))
+  (let* ((crumbs (reverse (cons (config-root-dir config)
+			    (cons (uri-host uri) (cdr (uri-path uri)))))))
     (make-pathname (reverse (cdr crumbs)) (car crumbs))))
 
 (define (document-path config uri)
@@ -186,7 +200,7 @@
                                 private-key: (config-keyfile config)
                                 protocol: 'tlsv12))
 
-  (print "Host: '" (config-host config) "'\n"
+  (print
          "Port: '" (config-port config) "'\n"
          "Root directory: '" (config-root-dir config) "'\n"
          "Cert file: '" (config-certfile config) "'\n"
@@ -230,11 +244,11 @@
     (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 " server-root-dir certfile keyfile")))
 
 (define (main)
   (let* ((progname (pathname-file (car (argv))))
-         (config (make-config #f #f 1965 #f #f #f #f)))
+         (config (make-config #f 1965 #f #f #f #f)))
     (if (null? (command-line-arguments))
         (print-usage progname)
         (let loop ((args (command-line-arguments)))
@@ -260,9 +274,8 @@
                  (else
                   (print-usage progname)))
                 (match args
-                  ((root-dir host certfile keyfile)
+                  ((root-dir certfile keyfile)
                    (config-root-dir-set! config root-dir)
-                   (config-host-set! config host)
                    (config-certfile-set! config certfile)
                    (config-keyfile-set! config keyfile)
                    (run-server config))
-- 
2.20.1