Using DNS , /etc/hosts with SUNOS 4.1.1 (more)

[Benoit Debande]

Hello,

In a previous UNIX-DIGEST, rob at sswax1.dnet.loral.com made a (long) mail about
using DNS and /etc/hosts with SUNOS 4.1

I followed his 2nd solution (based upond the sources of BIND) and applied
his modification to allow host lookup first by DNS and then on /etc/hosts.

This is the first patch enclosed : it replaces
 resolver.patch/gethostnamadr.c.patch
included in the file "bidon41.shar"

But, I'm not fully satisfied with the order of looking, and I prefer looking
first in /etc/hosts and then by DNS.  ie: that allows me to use local aliases
for hosts.

So, I made another modification to the sources, and it is the second patch
 enclosed.
It also replace the original one from the file "bidon41.shar".

I hope it will help ....

===============================================================================
      Dr. Benoit DEBANDE                      E-MAIL : debande at smd.ucl.ac.be
      School of Medicine                               debande at buclln11.bitnet
      Catholic University of Louvain	      FAX    : 32-2-7645322
      Av. Hippocrate 50 (50.20)               PHONE  : 32-2-7645268
      B-1200 BRUXELLES (BELGIUM)
===============================================================================
                Theory : it doesn't work an you know why
              Practice : it works an you don't know why
         C programming : it doesn't work and you don't know why
===============================================================================

FISRT ENCLOSURE : rob's modification patch

*** gethostnamadr.c.orig	Thu Jan  4 19:25:13 1990
--- gethostnamadr.c	Wed Mar 13 18:57:33 1991
***************
*** 40,49 ****
  static char hostbuf[BUFSIZ+1];
  static struct in_addr host_addr;
  static char HOSTDB[] = "/etc/hosts";
! static FILE *hostf = NULL;
  static char hostaddr[MAXADDRS];
  static char *host_addrs[2];
! static int stayopen = 0;
  char *strpbrk();

  #if PACKETSZ > 1024
--- 40,49 ----
  static char hostbuf[BUFSIZ+1];
  static struct in_addr host_addr;
  static char HOSTDB[] = "/etc/hosts";
! static FILE *hostf;
  static char hostaddr[MAXADDRS];
  static char *host_addrs[2];
! static int stayopen;
  char *strpbrk();

  #if PACKETSZ > 1024
***************
*** 261,270 ****
  		if (_res.options & RES_DEBUG)
  			printf("res_search failed\n");
  #endif
- 		if (errno == ECONNREFUSED)
  			return (_gethtbyname(name));
- 		else
- 			return ((struct hostent *) NULL);
  	}
  	return (getanswer(&buf, n, 0));
  }
--- 261,267 ----
***************
*** 293,301 ****
  		if (_res.options & RES_DEBUG)
  			printf("res_query failed\n");
  #endif
- 		if (errno == ECONNREFUSED)
  			return (_gethtbyaddr(addr, len, type));
- 		return ((struct hostent *) NULL);
  	}
  	hp = getanswer(&buf, n, 1);
  	if (hp == NULL)
--- 290,296 ----

SECOND ENCLOSURE my modification patch

*** gethostnamadr.c.orig	Thu Jan  4 19:25:13 1990
--- gethostnamadr.c	Wed Mar 13 18:47:49 1991
***************
*** 40,49 ****
  static char hostbuf[BUFSIZ+1];
  static struct in_addr host_addr;
  static char HOSTDB[] = "/etc/hosts";
! static FILE *hostf = NULL;
  static char hostaddr[MAXADDRS];
  static char *host_addrs[2];
! static int stayopen = 0;
  char *strpbrk();

  #if PACKETSZ > 1024
--- 40,49 ----
  static char hostbuf[BUFSIZ+1];
  static struct in_addr host_addr;
  static char HOSTDB[] = "/etc/hosts";
! static FILE *hostf;
  static char hostaddr[MAXADDRS];
  static char *host_addrs[2];
! static int stayopen;
  char *strpbrk();

  #if PACKETSZ > 1024
***************
*** 217,222 ****
--- 217,223 ----
  	register char *cp;
  	int n;
  	extern struct hostent *_gethtbyname();
+ 	struct hostent *hp;

  	/*
  	 * disallow names consisting only of digits/dots, unless
***************
*** 254,272 ****
  			}
  			if (!isdigit(*cp) && *cp != '.')
  				break;
! 		}

! 	if ((n = res_search(name, C_IN, T_A, buf.buf, sizeof(buf))) < 0) {
  #ifdef DEBUG
  		if (_res.options & RES_DEBUG)
  			printf("res_search failed\n");
  #endif
! 		if (errno == ECONNREFUSED)
! 			return (_gethtbyname(name));
! 		else
! 			return ((struct hostent *) NULL);
! 	}
! 	return (getanswer(&buf, n, 0));
  }

  struct hostent *
--- 255,275 ----
  			}
  			if (!isdigit(*cp) && *cp != '.')
  				break;
! 		      }

! 	if (( hp = _gethtbyname(name)) != NULL)
! 	  return(hp);
!
! 	if ((n = res_search(name, C_IN, T_A, buf.buf, sizeof(buf))) < 0)
  #ifdef DEBUG
  		if (_res.options & RES_DEBUG)
  			printf("res_search failed\n");
  #endif
! 	    return ((struct hostent *) NULL);
!
! 	 else
!
! 	    return (getanswer(&buf, n, 0));
  }

  struct hostent *
***************
*** 287,292 ****
--- 290,297 ----
  		((unsigned)addr[2] & 0xff),
  		((unsigned)addr[1] & 0xff),
  		((unsigned)addr[0] & 0xff));
+ 	if ((hp =_gethtbyaddr(addr, len, type)) != NULL)
+ 	  return(hp);
  	n = res_query(qbuf, C_IN, T_PTR, (char *)&buf, sizeof(buf));
  	if (n < 0) {
  #ifdef DEBUG
***************
*** 293,301 ****
  		if (_res.options & RES_DEBUG)
  			printf("res_query failed\n");
  #endif
! 		if (errno == ECONNREFUSED)
! 			return (_gethtbyaddr(addr, len, type));
! 		return ((struct hostent *) NULL);
  	}
  	hp = getanswer(&buf, n, 1);
  	if (hp == NULL)
--- 298,304 ----
  		if (_res.options & RES_DEBUG)
  			printf("res_query failed\n");
  #endif
! 			return ((struct hostent *) NULL);
  	}
  	hp = getanswer(&buf, n, 1);
  	if (hp == NULL)

--