X-Git-Url: https://git.distorted.org.uk/~mdw/zone/blobdiff_plain/f38bc59e4fdc74fc56553b04b0e135f0ee438747..f4e0c48f17d3c959d3751faba9ce9cd0becfba41:/zone.lisp

diff --git a/zone.lisp b/zone.lisp
index b0e5582..9e5795d 100644
--- a/zone.lisp
+++ b/zone.lisp
@@ -63,7 +63,7 @@
 (defun timespec-seconds (ts)
   "Convert a timespec TS to seconds.
 
-   A timespec may be a real count of seconds, or a list (COUNT UNIT): UNIT
+   A timespec may be a real count of seconds, or a list (COUNT UNIT).  UNIT
    may be any of a number of obvious time units."
   (cond ((null ts) 0)
 	((realp ts) (floor ts))
@@ -200,15 +200,21 @@
 
 (export 'zone-subdomain)
 (defstruct (zone-subdomain (:conc-name zs-))
-  "A subdomain.  Slightly weird.  Used internally by zone-process-records
-   below, and shouldn't escape."
+  "A subdomain.
+
+   Slightly weird.  Used internally by `zone-process-records', and shouldn't
+   escape."
   name
   ttl
   records)
 
 (export '*zone-output-path*)
-(defvar *zone-output-path* *default-pathname-defaults*
-  "Pathname defaults to merge into output files.")
+(defvar *zone-output-path* nil
+  "Pathname defaults to merge into output files.
+
+   If this is nil then use the prevailing `*default-pathname-defaults*'.
+   This is not the same as capturing the `*default-pathname-defaults*' from
+   load time.")
 
 (export '*preferred-subnets*)
 (defvar *preferred-subnets* nil
@@ -221,7 +227,7 @@
   "Choose a file name for a given ZONE and TYPE."
   (merge-pathnames (make-pathname :name (string-downcase zone)
 				  :type (string-downcase type))
-		   *zone-output-path*))
+		   (or *zone-output-path* *default-pathname-defaults*)))
 
 (export 'zone-preferred-subnet-p)
 (defun zone-preferred-subnet-p (name)
@@ -230,11 +236,12 @@
 
 (export 'preferred-subnet-case)
 (defmacro preferred-subnet-case (&body clauses)
-  "CLAUSES have the form (SUBNETS . FORMS).
+  "Execute a form based on which networks are considered preferred.
 
-   Evaluate the first FORMS whose SUBNETS (a list or single symbol, not
-   evaluated) are considered preferred by zone-preferred-subnet-p.  If
-   SUBNETS is the symbol t then the clause always matches."
+   The CLAUSES have the form (SUBNETS . FORMS) -- evaluate the first FORMS
+   whose SUBNETS (a list or single symbol, not evaluated) are listed in
+   `*preferred-subnets*'.  If SUBNETS is the symbol `t' then the clause
+   always matches."
   `(cond
     ,@(mapcar (lambda (clause)
 		(let ((subnets (car clause)))
@@ -253,8 +260,45 @@
 (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.
+
+   REC is a list of records of the form
+
+	({ :ttl TTL | TYPE DATA | (LABEL . REC) }*)
+
+   The various kinds of entries have the following meanings.
+
+   :ttl TTL		Set the TTL for subsequent records (at this level of
+			  nesting only).
+
+   TYPE DATA		Define a record with a particular TYPE and DATA.
+			  Record types are defined using `defzoneparse' and
+			  the syntax of the data is idiosyncratic.
+
+   ((LABEL ...) . REC)	Define records for labels within the zone.  Any
+			  records defined within REC will have their domains
+			  prefixed by each of the LABELs.  A singleton list
+			  of labels may instead be written as a single
+			  label.  Note, therefore, that
+
+				(host (sub :a \"169.254.1.1\"))
+
+			  defines a record for `host.sub' -- not `sub.host'.
+
+   If REC contains no top-level records, but it does define records for a
+   label listed in `*preferred-subnets*', then the records for the first such
+   label are also promoted to top-level.
+
+   The FUNC is called for each record encountered, represented as a
+   `zone-record' object.  Zone parsers are not called: you get the record
+   types and data from the input form; see `zone-parse-records' if you want
+   the raw output."
+
   (labels ((sift (rec ttl)
+	     ;; Parse the record list REC into lists of `zone-record' and
+	     ;; `zone-subdomain' objects, sorting out TTLs and so on.
+	     ;; Returns them as two values.
+
 	     (collecting (top sub)
 	       (loop
 		 (unless rec
@@ -275,7 +319,13 @@
 				     sub)))
 			 (t
 			  (error "Unexpected record form ~A" (car r))))))))
+
 	   (process (rec dom ttl)
+	     ;; Recursirvely process the record list REC, with a list DOM of
+	     ;; prefix labels, and a default TTL.  Promote records for a
+	     ;; preferred subnet to toplevel if there are no toplevel records
+	     ;; already.
+
 	     (multiple-value-bind (top sub) (sift rec ttl)
 	       (if (and dom (null top) sub)
 		   (let ((preferred
@@ -298,12 +348,16 @@
 		 (process (zs-records s)
 			  (cons (zs-name s) dom)
 			  (zs-ttl s))))))
+
+    ;; Process the records we're given with no prefix.
     (process rec nil ttl)))
 
 (export 'zone-parse-host)
 (defun zone-parse-host (f zname)
-  "Parse a host name F: if F ends in a dot then it's considered absolute;
-   otherwise it's relative to ZNAME."
+  "Parse a host name F.
+
+   If F ends in a dot then it's considered absolute; otherwise it's relative
+   to ZNAME."
   (setf f (stringify f))
   (cond ((string= f "@") (stringify zname))
 	((and (plusp (length f))
@@ -447,6 +501,11 @@
 
 (export 'zone-make-name)
 (defun zone-make-name (prefix zone-name)
+  "Compute a full domain name from a PREFIX and a ZONE-NAME.
+
+   If the PREFIX ends with `.' then it's absolute already; otherwise, append
+   the ZONE-NAME, separated with a `.'.  If PREFIX is nil, or `@', then
+   return the ZONE-NAME only."
   (if (or (not prefix) (string= prefix "@"))
       zone-name
       (let ((len (length prefix)))
@@ -462,7 +521,9 @@
 			&body body)
   "Define a new zone record type.
 
-   The TYPES may be a list of synonyms.  The other arguments are as follows:
+   The arguments are as follows:
+
+   TYPES	A singleton type symbol, or a list of aliases.
 
    NAME		The name of the record to be added.
 
@@ -512,32 +573,28 @@
 						   :make-ptr-p ,tmakeptrp)
 				 ,col)))
 		 ,@body)))
-	  ',type)))))
-
-(defun zone-parse-records (zone records)
-  (let ((zname (zone-name zone)))
-    (with-collection (rec)
-	(flet ((parse-record (zr)
-		 (let ((func (or (get (zr-type zr) 'zone-parse)
-				 (error "No parser for record ~A."
-					(zr-type zr))))
-		       (name (and (zr-name zr) (stringify (zr-name zr)))))
-		   (funcall func
-			    name
-			    zname
-			    (zr-data zr)
-			    (zr-ttl zr)
-			    rec))))
-	  (zone-process-records records
-				(zone-default-ttl zone)
-				#'parse-record))
-      (setf (zone-records zone) (nconc (zone-records zone) rec)))))
+	   ',type)))))
+
+(export 'zone-parse-records)
+(defun zone-parse-records (zname ttl records)
+  "Parse a sequence of RECORDS and return a list of raw records.
+
+   The records are parsed relative to the zone name ZNAME, and using the
+   given default TTL."
+  (collecting (rec)
+    (flet ((parse-record (zr)
+	     (let ((func (or (get (zr-type zr) 'zone-parse)
+			     (error "No parser for record ~A."
+				    (zr-type zr))))
+		   (name (and (zr-name zr) (stringify (zr-name zr)))))
+	       (funcall func name zname (zr-data zr) (zr-ttl zr) rec))))
+      (zone-process-records records ttl #'parse-record))))
 
 (export 'zone-parse)
 (defun zone-parse (zf)
   "Parse a ZONE form.
 
-  The syntax of a zone form is as follows:
+   The syntax of a zone form is as follows:
 
    ZONE-FORM:
      ZONE-HEAD ZONE-RECORD*
@@ -546,12 +603,10 @@
      ((NAME*) ZONE-RECORD*)
    | SYM ARGS"
   (multiple-value-bind (zname ttl soa) (zone-parse-head (car zf))
-    (let ((zone (make-zone :name zname
-			   :default-ttl ttl
-			   :soa soa
-			   :records nil)))
-      (zone-parse-records zone (cdr zf))
-      zone)))
+    (make-zone :name zname
+	       :default-ttl ttl
+	       :soa soa
+	       :records (zone-parse-records zname ttl (cdr zf)))))
 
 (export 'zone-create)
 (defun zone-create (zf)
@@ -601,6 +656,98 @@
   ":txt TEXT"
   (rec :data data))
 
+(export '*dkim-pathname-defaults*)
+(defvar *dkim-pathname-defaults*
+  (make-pathname :directory '(:relative "keys")
+		 :type "dkim"))
+
+(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 (merge-pathnames file *dkim-pathname-defaults*))
+		    (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)))))
+
+(eval-when (:load-toplevel :execute)
+  (dolist (item '((sshfp-algorithm rsa 1)
+		  (sshfp-algorithm dsa 2)
+		  (sshfp-algorithm ecdsa 3)
+		  (sshfp-type sha-1 1)
+		  (sshfp-type sha-256 2)))
+    (destructuring-bind (prop sym val) item
+      (setf (get sym prop) val)
+      (export sym))))
+
+(export '*sshfp-pathname-defaults*)
+(defvar *sshfp-pathname-defaults*
+  (make-pathname :directory '(:relative "keys")
+		 :type "sshfp"))
+
+(defzoneparse :sshfp (name data rec)
+  ":sshfp { FILENAME | ((FPR :alg ALG :type HASH)*) }"
+  (if (stringp data)
+      (with-open-file (in (merge-pathnames data *sshfp-pathname-defaults*))
+	(loop (let ((line (read-line in nil)))
+		(unless line (return))
+		(let ((words (str-split-words line)))
+		  (pop words)
+		  (when (string= (car words) "IN") (pop words))
+		  (unless (and (string= (car words) "SSHFP")
+			       (= (length words) 4))
+		    (error "Invalid SSHFP record."))
+		  (pop words)
+		  (destructuring-bind (alg type fpr) words
+		    (rec :data (list (parse-integer alg)
+				     (parse-integer type)
+				     fpr)))))))
+      (flet ((lookup (what prop)
+	       (etypecase what
+		 (fixnum what)
+		 (symbol (or (get what prop)
+			     (error "~S is not a known ~A" what prop))))))
+	(dolist (item (listify data))
+	  (destructuring-bind (fpr &key (alg 'rsa) (type 'sha-1))
+	      (listify item)
+	    (rec :data (list (lookup alg 'sshfp-algorithm)
+			     (lookup type 'sshfp-type)
+			     fpr)))))))
+
 (defzoneparse :mx (name data rec :zname zname)
   ":mx ((HOST :prio INT :ip IPADDR)*)"
   (dolist (mx (listify data))
@@ -765,6 +912,7 @@
   "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 +1021,10 @@ $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 :sshfp)) data)
+    (cons "~2D ~2D ~A" data))
+  (:method ((type (eql :txt)) data)
+    (cons "~#[\"\"~;~S~:;(~@{~%~8T~S~} )~]"
+	  (mapcar #'stringify (listify data)))))
 
 ;;;----- That's all, folks --------------------------------------------------