X-Git-Url: https://git.distorted.org.uk/~mdw/zone/blobdiff_plain/15db92449a34a2fede25d8ee3db38ab5cc206193..74962377fb06e415d2abe35833aa89c04090bde9:/addr-family-ipv6.lisp

diff --git a/addr-family-ipv6.lisp b/addr-family-ipv6.lisp
index 4bec06c..5ed014e 100644
--- a/addr-family-ipv6.lisp
+++ b/addr-family-ipv6.lisp
@@ -157,7 +157,8 @@
 
     ;; Third step: output the two parts of the address either side of the
     ;; longest zero run.  If there are no zero words in the address, just
-    ;; write the whole thing.
+    ;; write the whole thing.  There's a special case here for the
+    ;; IPv6-mapped IPv4 address space ::ffff:0.0.0.0/96.
     (with-output-to-string (out)
       (flet ((chunk (start end)
 	       (when (< start end)
@@ -167,8 +168,19 @@
 		     (incf i)
 		     (when (>= i end) (return))
 		     (write-char #\: out))))))
-	(cond ((null best-start)
+	(cond ((< best-length 2)
 	       (chunk 0 8))
+	      ((and (= best-start 0)
+		    (or (and (= best-length 5)
+			     (= (aref words 5) #xffff))
+			(= best-length 6)))
+	       (let ((v4addr (make-instance 'ip4addr
+					    :addr (ldb (byte 32 0) addr))))
+		 (write-string "::" out)
+		 (when (= best-length 5)
+		   (chunk 5 6)
+		   (write-char #\: out))
+		 (write-string (ipaddr-string v4addr) out)))
 	      (t
 	       (chunk 0 best-start)
 	       (write-string "::" out)