checkin for kjd. First cut at multiple address returns and BOMBPROOFING

SCCS-vsn: lib/libc/net/gethostnamadr.c 5.3

diff --git a/usr/src/lib/libc/net/gethostnamadr.c b/usr/src/lib/libc/net/gethostnamadr.c
index 95f6900..8b0cd93 100644 (file)
--- a/usr/src/lib/libc/net/gethostnamadr.c
+++ b/usr/src/lib/libc/net/gethostnamadr.c
@@ -1,11 +1,11 @@
 /*
 /*

- * Copyright (c) 1983 Regents of the University of California.
+ * Copyright (c) 1985 Regents of the University of California.

  * All rights reserved.  The Berkeley software License Agreement
  * specifies the terms and conditions for redistribution.
  */
 
 #ifndef lint
  * All rights reserved.  The Berkeley software License Agreement
  * specifies the terms and conditions for redistribution.
  */
 
 #ifndef lint

-static char sccsid[] = "@(#)gethostnamadr.c    5.2 (Berkeley) %G%";
+static char sccsid[] = "@(#)gethostnamadr.c    5.3 (Berkeley) %G%";

 #endif not lint
 
 #include <sys/types.h>
 #endif not lint
 
 #include <sys/types.h>


@@ -18,10 +18,30 @@ static char sccsid[] = "@(#)gethostnamadr.c 5.2 (Berkeley) %G%";
 
 #define        MAXALIASES      35
 
 
 #define        MAXALIASES      35
 

-static struct hostent host;
+#define XX 2
+static char h_addr_buf[sizeof(struct in_addr) * XX];
+static char *h_addr_ptr[XX] = {
+       &h_addr_buf[0],
+       &h_addr_buf[sizeof(struct in_addr)]
+};
+static struct hostent host = {
+       NULL,           /* official name of host */
+       NULL,           /* alias list */
+       0,              /* host address type */
+       0,              /* length of address */
+       h_addr_ptr      /* list of addresses from name server */
+};

 static char *host_aliases[MAXALIASES];
 static char hostbuf[BUFSIZ+1];
 
 static char *host_aliases[MAXALIASES];
 static char hostbuf[BUFSIZ+1];
 

+#ifdef BOMBPROOFING
+#include <ndbm.h>
+DBM *_host_db = NULL;
+int    _host_stayopen = 0;
+int    _host_bombed;
+struct hostent *_oldgethostbyname(), *_oldgethostbyaddr();
+#endif BOMBPROOFING
+

 static struct hostent *
 getanswer(msg, msglen, iquery)
        char *msg;
 static struct hostent *
 getanswer(msg, msglen, iquery)
        char *msg;


@@ -34,10 +54,16 @@ getanswer(msg, msglen, iquery)
        char *eom, *bp, **ap;
        int type, class, ancount, buflen;
 
        char *eom, *bp, **ap;
        int type, class, ancount, buflen;
 

+#ifdef BOMBPROOFING
+       _host_bombed = 0;
+#endif BOMBPROOFING

        n = res_send(msg, msglen, answer, sizeof(answer));
        if (n < 0) {
                if (_res.options & RES_DEBUG)
                        printf("res_send failed\n");
        n = res_send(msg, msglen, answer, sizeof(answer));
        if (n < 0) {
                if (_res.options & RES_DEBUG)
                        printf("res_send failed\n");

+#ifdef BOMBPROOFING
+               _host_bombed++;
+#endif BOMBPROOFING

                return (NULL);
        }
        eom = answer + n;
                return (NULL);
        }
        eom = answer + n;


@@ -49,6 +75,10 @@ getanswer(msg, msglen, iquery)
        if (hp->rcode != NOERROR || ancount == 0) {
                if (_res.options & RES_DEBUG)
                        printf("rcode = %d, ancount=%d\n", hp->rcode, ancount);
        if (hp->rcode != NOERROR || ancount == 0) {
                if (_res.options & RES_DEBUG)
                        printf("rcode = %d, ancount=%d\n", hp->rcode, ancount);

+#ifdef BOMBPROOFING
+               if (!(hp->rcode == NOERROR && ancount == 0))
+                       _host_bombed++;
+#endif BOMBPROOFING

                return (NULL);
        }
        bp = hostbuf;
                return (NULL);
        }
        bp = hostbuf;


@@ -117,6 +147,9 @@ gethostbyname(name)
        char *name;
 {
        int n;
        char *name;
 {
        int n;

+#ifdef BOMBPROOFING
+       register struct hostent *hp;
+#endif BOMBPROOFING

 
        n = res_mkquery(QUERY, name, C_ANY, T_A, NULL, 0, NULL,
                hostbuf, sizeof(hostbuf));
 
        n = res_mkquery(QUERY, name, C_ANY, T_A, NULL, 0, NULL,
                hostbuf, sizeof(hostbuf));


@@ -124,8 +157,17 @@ gethostbyname(name)
                if (_res.options & RES_DEBUG)
                        printf("res_mkquery failed\n");
                return (NULL);
                if (_res.options & RES_DEBUG)
                        printf("res_mkquery failed\n");
                return (NULL);

+#ifndef BOMBPROOFING

        }
        }

-       return (getanswer(hostbuf, n, 0));
+       return(getanswer(hostbuf, n, 0));
+#else
+       } else
+               hp = getanswer(hostbuf, n, 0);
+       if (n < 0 || (hp == NULL && _host_bombed))
+               return (_oldgethostbyname(name));
+       else
+               return (hp);
+#endif BOMBPROOFING

 }
 
 struct hostent *
 }
 
 struct hostent *


@@ -134,6 +176,9 @@ gethostbyaddr(addr, len, type)
        int len, type;
 {
        int n;
        int len, type;
 {
        int n;

+#ifdef BOMBPROOFING
+       register struct hostent *hp;
+#endif BOMBPROOFING

 
        if (type != AF_INET)
                return (NULL);
 
        if (type != AF_INET)
                return (NULL);


@@ -143,6 +188,85 @@ gethostbyaddr(addr, len, type)
                if (_res.options & RES_DEBUG)
                        printf("res_mkquery failed\n");
                return (NULL);
                if (_res.options & RES_DEBUG)
                        printf("res_mkquery failed\n");
                return (NULL);

+#ifndef BOMBPROOFING

        }
        return (getanswer(hostbuf, n, 1));
        }
        return (getanswer(hostbuf, n, 1));

+#else
+       } else
+               hp = getanswer(hostbuf, n, 1);
+       if (n < 0 || (hp == NULL && _host_bombed))
+               return (_oldgethostbyaddr(addr));
+       else
+               return (hp);
+#endif BOMBPROOFING

 }
 }

+
+#ifdef BOMBPROOFING
+static
+struct hostent *
+_oldgethostbyname(name)
+       register char *name;
+{
+       register struct hostent *hp;
+       register char **cp;
+        datum key;
+
+       if ((_host_db == (DBM *)NULL)
+         && ((_host_db = dbm_open(_host_file, O_RDONLY)) == (DBM *)NULL)) {
+               sethostent(_host_stayopen);
+               while (hp = gethostent()) {
+                       if (strcmp(hp->h_name, nam) == 0)
+                               break;
+                       for (cp = hp->h_aliases; cp != 0 && *cp != 0; cp++)
+                               if (strcmp(*cp, nam) == 0)
+                                       goto found;
+               }
+       found:
+               if (!_host_stayopen)
+                       endhostent();
+               return (hp);
+       }
+        key.dptr = nam;
+        key.dsize = strlen(nam);
+       hp = fetchhost(key);
+       if (!_host_stayopen) {
+               dbm_close(_host_db);
+               _host_db = (DBM *)NULL;
+       }
+        return (hp);
+}
+
+
+static
+struct hostent *
+_oldgethostbyaddr(addr, len, type)
+       char *addr;
+       register int len, type;
+{
+
+       register struct hostent *hp;
+        datum key;
+
+       if ((_host_db == (DBM *)NULL)
+         && ((_host_db = dbm_open(_host_file, O_RDONLY)) == (DBM *)NULL)) {
+               sethostent(_host_stayopen);
+               while (hp = gethostent()) {
+                       if (hp->h_addrtype == type && hp->h_length == length
+                           && bcmp(hp->h_addr, addr, length) == 0)
+                               break;
+               }
+               if (!_host_stayopen)
+                       endhostent();
+               return (hp);
+       }
+        key.dptr = addr;
+        key.dsize = length;
+       hp = fetchhost(key);
+       if (!_host_stayopen) {
+               dbm_close(_host_db);
+               _host_db = (DBM *)NULL;
+       }
+        return (hp);
+}
+#endif BOMBPROOFING
+