🚀 go-pugleaf

Subject: /etc/hosts and multiple addresses (2nd try)
Index:	lib/libc/net/hosttable/gethnamadr.c 2.10BSD

Description:
	The /etc/hosts file does not correctly handle the
	case where a host has more than one address - only the
	first is returned when a gethostbyaddr() is performed.

Repeat-By:
	Do a gethostbyname() on a host with multiple addresses, print the
	addresses returned in h_addr_list, note there will be only one.

Fix:
	Apply the patches below to gethostent.c and gethnamadr.c, replace
	gethnamadr.o and gethostent.o in libc.a and libc_p.a.
	install in /etc.

	This is the second (and hopefully last) correction, 
	I blew it in the earlier patch to gethnamadr.c

	The latest versions of rlogind(8) and rshd(8) were the reason
	for making changes to mkhosts(8) - if a host has more than one
	address, the authentication performed by rshd(8) and rlogind(8)
	would fail.

	It turns out that a static area is required after all.  
	To help save some D-space the maximum number of aliases is reduced 
	from 35 to 20 (still seems way too high - i've never seen more 
	than 5 or 6 aliases) the maximum line length is reduced to 160 
	from 256 and the address buffer in gethostent.c is down sized
	as well.
	
*** gethnamadr.old	Tue Aug 23 14:45:14 1988
--- gethnamadr.c	Sat Oct  7 14:02:26 1989
***************
*** 15,26 ****
  #include <ndbm.h>
  #include <ctype.h>
  
! #define	MAXALIASES	35
  
  static struct hostent host;
  static char *host_aliases[MAXALIASES];
! static char hostbuf[256+1];
! static char *host_addrs[2];
  
  int h_errno;
  
--- 15,27 ----
  #include <ndbm.h>
  #include <ctype.h>
  
! #define	MAXALIASES	20
! #define	MAXADDRS	10
  
  static struct hostent host;
+ static char hostbuf[256];
  static char *host_aliases[MAXALIASES];
! static char *host_addrs[MAXADDRS];
  
  int h_errno;
  
***************
*** 36,42 ****
  	datum key;
  {
          register char *cp, *tp, **ap;
! 	int naliases;
  
          if (key.dptr == 0)
                  return ((struct hostent *)NULL);
--- 37,43 ----
  	datum key;
  {
          register char *cp, *tp, **ap;
! 	int naliases, naddrs;
  
          if (key.dptr == 0)
                  return ((struct hostent *)NULL);
***************
*** 43,54 ****
  	key = dbm_fetch(_host_db, key);
  	if (key.dptr == 0)
                  return ((struct hostent *)NULL);
!         cp = key.dptr;
! 	tp = hostbuf;
  	host.h_name = tp;
  	while (*tp++ = *cp++)
  		;
! 	bcopy(cp, (char *)&naliases, sizeof(int)); cp += sizeof (int);
  	for (ap = host_aliases; naliases > 0; naliases--) {
  		*ap++ = tp;
  		while (*tp++ = *cp++)
--- 44,56 ----
  	key = dbm_fetch(_host_db, key);
  	if (key.dptr == 0)
                  return ((struct hostent *)NULL);
! 	cp = key.dptr;
!         tp = hostbuf;
  	host.h_name = tp;
  	while (*tp++ = *cp++)
  		;
! 	bcopy(cp, (char *)&naliases, sizeof(int));
! 	cp += sizeof (int);
  	for (ap = host_aliases; naliases > 0; naliases--) {
  		*ap++ = tp;
  		while (*tp++ = *cp++)
***************
*** 61,68 ****
  	bcopy(cp, (char *)&host.h_length, sizeof (int));
  	cp += sizeof (int);
  	host.h_addr_list = host_addrs;
! 	host.h_addr = tp;
! 	bcopy(cp, tp, host.h_length);
          return (&host);
  }
  
--- 63,78 ----
  	bcopy(cp, (char *)&host.h_length, sizeof (int));
  	cp += sizeof (int);
  	host.h_addr_list = host_addrs;
! 	naddrs = (key.dsize - (cp - key.dptr)) / host.h_length;
! 	if (naddrs > MAXADDRS)
! 		naddrs = MAXADDRS;
! 	for (ap = host_addrs; naddrs; naddrs--) {
! 		*ap++ = tp;
! 		bcopy(cp, tp, host.h_length);
! 		cp += host.h_length;
! 		tp += host.h_length;
! 	}
! 	*ap = (char *)NULL;
          return (&host);
  }
  
*** gethostent.old	Sat Oct  7 14:08:14 1989
--- gethostent.c	Sat Oct  7 14:03:41 1989
***************
*** 19,29 ****
  /*
   * Internet version.
   */
! #define	MAXALIASES	35
! #define	MAXADDRSIZE	14
  
  static FILE *hostf = NULL;
! static char line[256+1];
  static char hostaddr[MAXADDRSIZE];
  static struct hostent host;
  static char *host_aliases[MAXALIASES];
--- 19,29 ----
  /*
   * Internet version.
   */
! #define	MAXALIASES	20
! #define	MAXADDRSIZE	(sizeof (u_long))
  
  static FILE *hostf = NULL;
! static char line[160+1];
  static char hostaddr[MAXADDRSIZE];
  static struct hostent host;
  static char *host_aliases[MAXALIASES];