From: mdw <mdw>
Date: Sat, 3 Jul 1999 13:56:04 +0000 (+0000)
Subject: Perform a forward resolution to verify result of reverse lookup.
X-Git-Tag: 1.0.0~2
X-Git-Url: https://git.distorted.org.uk/~mdw/fwd/commitdiff_plain/08c3700b9bfe51e9b09c11a3aff64bcfad11f52b

Perform a forward resolution to verify result of reverse lookup.
---

diff --git a/bres.c b/bres.c
index d04d15f..0d09f3b 100644
--- a/bres.c
+++ b/bres.c
@@ -1,6 +1,6 @@
 /* -*-c-*-
  *
- * $Id: bres.c,v 1.1 1999/07/01 08:56:23 mdw Exp $
+ * $Id: bres.c,v 1.2 1999/07/03 13:56:04 mdw Exp $
  *
  * Background reverse name resolution
  *
@@ -29,8 +29,11 @@
 /*----- Revision history --------------------------------------------------* 
  *
  * $Log: bres.c,v $
- * Revision 1.1  1999/07/01 08:56:23  mdw
- * Initial revision
+ * Revision 1.2  1999/07/03 13:56:04  mdw
+ * Perform a forward resolution to verify result of reverse lookup.
+ *
+ * Revision 1.1.1.1  1999/07/01 08:56:23  mdw
+ * Initial revision.
  *
  */
 
@@ -52,6 +55,7 @@
 #include <arpa/inet.h>
 #include <netdb.h>
 
+#include <mLib/alloc.h>
 #include <mLib/report.h>
 #include <mLib/sel.h>
 #include <mLib/selbuf.h>
@@ -166,9 +170,26 @@ static void child(int rfd, int cfd)
       continue;
 
     h = gethostbyaddr((char *)&addr, sizeof(addr), AF_INET);
-    if (h)
-      p = h->h_name;
-    else
+    if (h) {
+      char **pp;
+
+      p = xstrdup(h->h_name);
+      h = gethostbyname(p);
+      free(p);
+      p = 0;
+      if (h) {
+	for (pp = h->h_addr_list; *pp; pp++) {
+	  struct in_addr a;
+	  memcpy(&a, *pp, sizeof(a));
+	  if (a.s_addr == addr.s_addr) {
+	    p = h->h_name;
+	    break;
+	  }
+	}
+      }
+    }
+
+    if (!p)
       p = inet_ntoa(addr);
     fprintf(fp, "%s\n", p);
     fflush(fp);