zone.lisp: Support for DKIM key records.

[zone] / zone.lisp

diff --git a/zone.lisp b/zone.lisp
index b0e5582..762c6e2 100644 (file)
--- a/zone.lisp
+++ b/zone.lisp
@@ -253,7 +253,25 @@
 (defun zone-process-records (rec ttl func)
   "Sort out the list of records in REC, calling FUNC for each one.
 
-   TTL is the default time-to-live for records which don't specify one."
+   TTL is the default time-to-live for records which don't specify one.
+
+   The syntax is a little fiddly to describe.  It operates relative to a
+   subzone name NAME.
+
+   ZONE-RECORD: RR | TTL | SUBZONE
+       The body of a zone form is a sequence of these.
+
+   TTL: :ttl INTEGER
+       Sets the TTL for subsequent RRs in this zone or subzone.
+
+   RR: SYMBOL DATA
+       Adds a record for the current NAME; the SYMBOL denotes the record
+       type, and the DATA depends on the type.
+
+   SUBZONE: (LABELS ZONE-RECORD*)
+       Defines a subzone.  The LABELS is either a list of labels, or a
+       singleton label.  For each LABEL, evaluate the ZONE-RECORDs relative
+       to LABEL.NAME.  The special LABEL `@' is a no-op."
   (labels ((sift (rec ttl)
             (collecting (top sub)
               (loop
@@ -515,6 +533,9 @@
          ',type)))))
 
 (defun zone-parse-records (zone records)
+  "Parse the body of a zone form.
+
+   ZONE is the zone object; RECORDS is the body of the form."
   (let ((zname (zone-name zone)))
     (with-collection (rec)
        (flet ((parse-record (zr)
@@ -601,6 +622,48 @@
   ":txt TEXT"
   (rec :data data))
 
+(defzoneparse :dkim (name data rec)
+  ":dkim (KEYFILE {:TAG VALUE}*)"
+  (destructuring-bind (file &rest plist) (listify data)
+    (let ((things nil) (out nil))
+      (labels ((flush ()
+                (when out
+                  (push (get-output-stream-string out) things)
+                  (setf out nil)))
+              (emit (text)
+                (let ((len (length text)))
+                  (when (and out (> (+ (file-position out)
+                                       (length text))
+                                    64))
+                    (flush))
+                  (when (plusp len)
+                    (cond ((< len 64)
+                           (unless out (setf out (make-string-output-stream)))
+                           (write-string text out))
+                          (t
+                           (do ((i 0 j)
+                                (j 64 (+ j 64)))
+                               ((>= i len))
+                             (push (subseq text i (min j len)) things))))))))
+       (do ((p plist (cddr p)))
+           ((endp p))
+         (emit (format nil "~(~A~)=~A;" (car p) (cadr p))))
+       (emit (with-output-to-string (out)
+               (write-string "p=" out)
+               (when file
+                 (with-open-file (in file :direction :input)
+                   (loop
+                     (when (string= (read-line in)
+                                    "-----BEGIN PUBLIC KEY-----")
+                       (return)))
+                   (loop
+                     (let ((line (read-line in)))
+                       (if (string= line "-----END PUBLIC KEY-----")
+                           (return)
+                           (write-string line out)))))))))
+      (rec :type :txt
+          :data (nreverse things)))))
+
 (defzoneparse :mx (name data rec :zname zname)
   ":mx ((HOST :prio INT :ip IPADDR)*)"
   (dolist (mx (listify data))
@@ -765,6 +828,7 @@
   "Stream to write zone data on.")
 
 (defmethod zone-write :around (format zone stream)
+  (declare (ignore format))
   (let ((*writing-zone* zone)
        (*zone-output-stream* stream))
     (call-next-method)))
@@ -873,6 +937,8 @@ $TTL ~2@*~D~2%"
   (:method ((type (eql :srv)) data)
     (destructuring-bind (prio weight port host) data
       (list "~2D ~5D ~5D ~A" prio weight port (bind-hostname host))))
-  (:method ((type (eql :txt)) data) (list "~S" (stringify data))))
+  (:method ((type (eql :txt)) data)
+    (cons "~#[\"\"~;~S~:;(~@{~%~8T~S~} )~]"
+         (mapcar #'stringify (listify data)))))
 
 ;;;----- That's all, folks --------------------------------------------------