Prevent buffer overruns.

[~andy/fetchmail] / mxget.c

diff --git a/mxget.c b/mxget.c
index 484d7aad87ab6346e85eb66db8068da95d8ba033..726417b18de8ed2556bc42a60b1fb5a9ab34cff2 100644 (file)
--- a/mxget.c
+++ b/mxget.c
@@ -1,13 +1,13 @@
 /*
  * mxget.c -- fetch MX records for given DNS name
  *
- * Copyright 1996 by Eric S. Raymond
- * All rights reserved.
+ * Copyright 1997 by Eric S. Raymond
  * For license terms, see the file COPYING in this directory.
  */
 
 #include "config.h"
 #ifdef HAVE_RES_SEARCH
+#include <stdio.h>
 #include <netdb.h>
 #include <sys/types.h>
 #include <netinet/in.h>
@@ -40,9 +40,8 @@
 /* minimum possible size of MX record in packet */
 #define MIN_MX_SIZE    8       /* corresp to "a.com 0" w/ terminating space */
 
-struct mxentry *getmxrecords(name)
+struct mxentry *getmxrecords(const unsigned char *name)
 /* get MX records for given host */
-const char *name;
 {
     unsigned char answer[PACKETSZ], *eom, *cp, *bp;
     int n, ancount, qdcount, buflen, type, pref, ind;
@@ -50,7 +49,10 @@ const char *name;
     static char MXHostBuf[PACKETSZ - HFIXEDSZ]; 
     HEADER *hp;
 
-    n = res_search(name,C_IN,T_MX,(unsigned char*)&answer, sizeof(answer));
+    pmx->name = (char *)NULL;
+    pmx->pref = -1;
+    n = res_search((char *)name,
+                  C_IN,T_MX, (unsigned char*)&answer, sizeof(answer));
     if (n == -1)
        return((struct mxentry *)NULL);
 
@@ -87,7 +89,7 @@ const char *name;
        pmx[ind].pref = pref;
        ++ind;
 
-       n = strlen(bp);
+       n = strlen((const char *)bp);
        bp += n;
        *bp++ = '\0';