misc/172390: __res_state_ext missing from system headers

[Antonio Querubin]

>Number:         172390
>Category:       misc
>Synopsis:       __res_state_ext missing from system headers
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Sat Oct 06 11:10:13 UTC 2012
>Closed-Date:
>Last-Modified:
>Originator:     Antonio Querubin
>Release:        9.0
>Organization:
>Environment:
FreeBSD vm2 9.0-RELEASE FreeBSD 9.0-RELEASE #0: Tue Jan  3 07:15:25 UTC 2012     root at obrian.cse.buffalo.edu:/usr/obj/usr/src/sys/GENERIC  i386
>Description:
Programs that use the resolver library but query IPv6 resolvers directly require access to the IPv6 extensions in resolv.h.  However, the definition for struct __res_state_ext is missing from the standard system header files.
>How-To-Repeat:
The following will fail to compile:

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

int main(void) {
  struct __res_state myres;
  struct __res_state_ext *myres6;
  struct sockaddr_in6 *mysockaddr6;

  res_ninit(&myres);
  myres6 = myres._u._ext.ext;
  mysockaddr6 = &(myres6->nsaddrs[0].sin6); 
}

>Fix:
Include a definition for struct __res_state_ext in resolv.h

struct __res_state_ext {
        union res_sockaddr_union nsaddrs[MAXNS];
        struct sort_list {
                int     af;
                union {
                        struct in_addr  ina;
                        struct in6_addr in6a;
                } addr, mask;
        } sort_list[MAXRESOLVSORT];
        char nsuffix[64];
        char nsuffix2[64];
};


>Release-Note:
>Audit-Trail:
>Unformatted: