Bug 150288

Created attachment 111657 [details]
sendmail.cf

FWIW, changing 'DSpobox.surrey.redhat.com' to 'DS[pobox.surrey.redhat.com]' in
sendmail.cf made this work again, but I couldn't work out why res_search() was
returning -1 but leaving h_errno=0.

I think this is a bind problem, not a sendmail problem.  The following
program prints h_errno=4 correctly when linked against the libresolv
that comes with glibc but prints h_errno when linked against the
libbind that comes with bind-libs-9.3.1rc1-3.

#include <netinet/in.h>
#include <arpa/nameser.h>
#include <resolv.h>
#include <netdb.h>

main()
{
  int ret;
  unsigned char answer[256] = {0};

  res_init();
  ret = res_search("105-10.202-68.tampabay.res.rr.com.", ns_c_in, ns_t_mx,
		   answer, sizeof answer);
  printf("ret=%d, h_errno=%d, answer=%s\n", ret, h_errno, answer);
}

This problem is now fixed with bind-9.3.1rc1-5 .

Incorrect assumptions in the code about pthread
availability resulted in the wrong h_errno_location()
being used.   

Note that the res_search function is deprecated, and the proper
way to write the above code would be:

#include <sys/types.h>
#include <unistd.h>
#include <string.h>
#include <netinet/in.h>
#include <bind/arpa/inet.h>
#include <bind/arpa/nameser.h>
#include <bind/resolv.h>
#include <bind/netdb.h>
#include <stdio.h>

static struct __res_state res;

main()
{
  int ret;
  unsigned char answer[256] = {0};


  memset(&res, '\0', sizeof(res));
  res_ninit(&res);
  ret = res_nsearch(&res,"105-10.202-68.tampabay.res.rr.com.",
ns_c_in, ns_t_mx,
		   answer, sizeof answer);
  printf("ret=%d, h_errno=%d\n", ret, h_errno);
  if ( ret > 0 )
      fp_nquery(answer,ret,stdout);
}

*** Bug 150703 has been marked as a duplicate of this bug. ***

Looks like fixed. If still exists, please reopen.

Regards, Adam

Huh, after investigation about bug #245857 patch for this bug is completely wrong. 
About comment #3 :
libbind uses different resolving mechanisms so if you want use libbind resolver
you must bind/* headers instead glibc's headers (as Jason wrote in comment #4).
Also I believe when sendmail was linked against libbind it includes wrong
headers => NOTABUG

Adam

This problem needs more investigation especially with recently upstream changes.
Patch's idea is completely unusable

2205.   [bug]           libbind: change #2119 broke thread support. [RT #16982]
2119.   [compat]        libbind: allow res_init() to succeed enough to
                        return the default domain even if it was unable
                        to allocate memory.

*** This bug has been marked as a duplicate of 254501 ***