cleanups on handling SIGHUP; other nits

[unix-history] / usr / src / lib / libc / net / res_query.c

diff --git a/usr/src/lib/libc/net/res_query.c b/usr/src/lib/libc/net/res_query.c
index 5b1ed65..ef1e24b 100644 (file)
--- a/usr/src/lib/libc/net/res_query.c
+++ b/usr/src/lib/libc/net/res_query.c
@@ -2,29 +2,24 @@
  * Copyright (c) 1988 Regents of the University of California.
  * All rights reserved.
  *
  * Copyright (c) 1988 Regents of the University of California.
  * All rights reserved.
  *

- * Redistribution and use in source and binary forms are permitted
- * provided that this notice is preserved and that due credit is given
- * to the University of California at Berkeley. The name of the University
- * may not be used to endorse or promote products derived from this
- * software without specific prior written permission. This software
- * is provided ``as is'' without express or implied warranty.
+ * %sccs.include.redist.c%

  */
 
 #if defined(LIBC_SCCS) && !defined(lint)
  */
 
 #if defined(LIBC_SCCS) && !defined(lint)

-static char sccsid[] = "@(#)res_query.c        5.2 (Berkeley) %G%";
+static char sccsid[] = "@(#)res_query.c        5.11 (Berkeley) %G%";

 #endif /* LIBC_SCCS and not lint */
 
 #include <sys/param.h>
 #endif /* LIBC_SCCS and not lint */
 
 #include <sys/param.h>

-#include <sys/socket.h>

 #include <netinet/in.h>
 #include <netinet/in.h>

-#include <ctype.h>
-#include <netdb.h>
-#include <stdio.h>
-#include <errno.h>
-#include <strings.h>

 #include <arpa/inet.h>
 #include <arpa/nameser.h>
 #include <arpa/inet.h>
 #include <arpa/nameser.h>

+#include <netdb.h>

 #include <resolv.h>
 #include <resolv.h>

+#include <stdio.h>
+#include <ctype.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>

 
 #if PACKETSZ > 1024
 #define MAXPACKET      PACKETSZ
 
 #if PACKETSZ > 1024
 #define MAXPACKET      PACKETSZ


@@ -32,7 +27,6 @@ static char sccsid[] = "@(#)res_query.c       5.2 (Berkeley) %G%";
 #define MAXPACKET      1024
 #endif
 
 #define MAXPACKET      1024
 #endif
 

-extern int errno;

 int h_errno;
 
 /*
 int h_errno;
 
 /*


@@ -71,7 +65,7 @@ res_query(name, class, type, answer, anslen)
                h_errno = NO_RECOVERY;
                return (n);
        }
                h_errno = NO_RECOVERY;
                return (n);
        }

-       n = res_send(buf, n, answer, anslen);
+       n = res_send(buf, n, (char *)answer, anslen);

        if (n < 0) {
 #ifdef DEBUG
                if (_res.options & RES_DEBUG)
        if (n < 0) {
 #ifdef DEBUG
                if (_res.options & RES_DEBUG)


@@ -96,7 +90,7 @@ res_query(name, class, type, answer, anslen)
                                h_errno = TRY_AGAIN;
                                break;
                        case NOERROR:
                                h_errno = TRY_AGAIN;
                                break;
                        case NOERROR:

-                               h_errno = NO_ADDRESS;
+                               h_errno = NO_DATA;

                                break;
                        case FORMERR:
                        case NOTIMP:
                                break;
                        case FORMERR:
                        case NOTIMP:


@@ -125,21 +119,29 @@ res_search(name, class, type, answer, anslen)
        int anslen;             /* size of answer */
 {
        register char *cp, **domain;
        int anslen;             /* size of answer */
 {
        register char *cp, **domain;

-       int n, ret;
-       char *hostalias();
+       int n, ret, got_nodata = 0;
+       char *__hostalias();

 
        if ((_res.options & RES_INIT) == 0 && res_init() == -1)
                return (-1);
 
        errno = 0;
 
        if ((_res.options & RES_INIT) == 0 && res_init() == -1)
                return (-1);
 
        errno = 0;

+       h_errno = HOST_NOT_FOUND;               /* default, if we never query */

        for (cp = name, n = 0; *cp; cp++)
                if (*cp == '.')
                        n++;
        for (cp = name, n = 0; *cp; cp++)
                if (*cp == '.')
                        n++;

-       if (n == 0 && (cp = hostalias(name)))
+       if (n == 0 && (cp = __hostalias(name)))

                return (res_query(cp, class, type, answer, anslen));
 
                return (res_query(cp, class, type, answer, anslen));
 

-       if ((n == 0 || *--cp != '.') && (_res.options & RES_DEFNAMES))
-           for (domain = _res.dnsrch; *domain; domain++) {
+       /*
+        * We do at least one level of search if
+        *      - there is no dot and RES_DEFNAME is set, or
+        *      - there is at least one dot, there is no trailing dot,
+        *        and RES_DNSRCH is set.
+        */
+       if ((n == 0 && _res.options & RES_DEFNAMES) ||
+          (n != 0 && *--cp != '.' && _res.options & RES_DNSRCH))
+            for (domain = _res.dnsrch; *domain; domain++) {

                ret = res_querydomain(name, *domain, class, type,
                    answer, anslen);
                if (ret > 0)
                ret = res_querydomain(name, *domain, class, type,
                    answer, anslen);
                if (ret > 0)


@@ -149,30 +151,35 @@ res_search(name, class, type, answer, anslen)
                 * If name isn't found in this domain,
                 * keep trying higher domains in the search list
                 * (if that's enabled).
                 * If name isn't found in this domain,
                 * keep trying higher domains in the search list
                 * (if that's enabled).

-                * On a NO_ADDRESS error, keep trying, otherwise
+                * On a NO_DATA error, keep trying, otherwise

                 * a wildcard entry of another type could keep us
                 * from finding this entry higher in the domain.
                 * a wildcard entry of another type could keep us
                 * from finding this entry higher in the domain.

-                * If we get some other error (non-authoritative negative
-                * answer or server failure), then stop searching up,
+                * If we get some other error (negative answer or
+                * server failure), then stop searching up,

                 * but try the input name below in case it's fully-qualified.
                 */
                if (errno == ECONNREFUSED) {
                        h_errno = TRY_AGAIN;
                        return (-1);
                }
                 * but try the input name below in case it's fully-qualified.
                 */
                if (errno == ECONNREFUSED) {
                        h_errno = TRY_AGAIN;
                        return (-1);
                }

-               if ((h_errno != HOST_NOT_FOUND && h_errno != NO_ADDRESS) ||
+               if (h_errno == NO_DATA)
+                       got_nodata++;
+               if ((h_errno != HOST_NOT_FOUND && h_errno != NO_DATA) ||

                    (_res.options & RES_DNSRCH) == 0)
                        break;
                    (_res.options & RES_DNSRCH) == 0)
                        break;

-               h_errno = 0;

        }
        /*
         * If the search/default failed, try the name as fully-qualified,
         * but only if it contained at least one dot (even trailing).
        }
        /*
         * If the search/default failed, try the name as fully-qualified,
         * but only if it contained at least one dot (even trailing).

+        * This is purely a heuristic; we assume that any reasonable query
+        * about a top-level domain (for servers, SOA, etc) will not use
+        * res_search.

         */
         */

-       if (n)
-               return (res_querydomain(name, (char *)NULL, class, type,
-                   answer, anslen));
-       h_errno = HOST_NOT_FOUND;
+       if (n && (ret = res_querydomain(name, (char *)NULL, class, type,
+           answer, anslen)) > 0)
+               return (ret);
+       if (got_nodata)
+               h_errno = NO_DATA;

        return (-1);
 }
 
        return (-1);
 }
 


@@ -190,6 +197,11 @@ res_querydomain(name, domain, class, type, answer, anslen)
        char *longname = nbuf;
        int n;
 
        char *longname = nbuf;
        int n;
 

+#ifdef DEBUG
+       if (_res.options & RES_DEBUG)
+               printf("res_querydomain(%s, %s, %d, %d)\n",
+                   name, domain, class, type);
+#endif

        if (domain == NULL) {
                /*
                 * Check for trailing '.';
        if (domain == NULL) {
                /*
                 * Check for trailing '.';


@@ -209,8 +221,8 @@ res_querydomain(name, domain, class, type, answer, anslen)
 }
 
 char *
 }
 
 char *

-hostalias(name)
-       register char *name;
+__hostalias(name)
+       register const char *name;

 {
        register char *C1, *C2;
        FILE *fp;
 {
        register char *C1, *C2;
        FILE *fp;