NAME

       krb5_krbhst_init,       krb5_krbhst_init_flags,       krb5_krbhst_next,       krb5_krbhst_next_as_string,
       krb5_krbhst_reset,  krb5_krbhst_free,  krb5_krbhst_format_string,   krb5_krbhst_get_addrinfo   —   lookup
       Kerberos KDC hosts

LIBRARY

       Kerberos 5 Library (libkrb5, -lkrb5)

SYNOPSIS

       #include <krb5.h>

       krb5_error_code
       krb5_krbhst_init(krb5_context context, const char *realm, unsigned int type, krb5_krbhst_handle *handle);

       krb5_error_code
       krb5_krbhst_init_flags(krb5_context   context,   const   char  *realm,  unsigned  int  type,  int  flags,
           krb5_krbhst_handle *handle);

       krb5_error_code
       krb5_krbhst_next(krb5_context context, krb5_krbhst_handle handle, krb5_krbhst_info **host);

       krb5_error_code
       krb5_krbhst_next_as_string(krb5_context   context,    krb5_krbhst_handle    handle,    char    *hostname,
           size_t hostlen);

       void
       krb5_krbhst_reset(krb5_context context, krb5_krbhst_handle handle);

       void
       krb5_krbhst_free(krb5_context context, krb5_krbhst_handle handle);

       krb5_error_code
       krb5_krbhst_format_string(krb5_context   context,   const   krb5_krbhst_info   *host,   char   *hostname,
           size_t hostlen);

       krb5_error_code
       krb5_krbhst_get_addrinfo(krb5_context context, krb5_krbhst_info *host, struct addrinfo **ai);

DESCRIPTION

       These functions are used to sequence through all Kerberos hosts of a particular realm  and  service.  The
       service  type  can be the KDCs, the administrative servers, the password changing servers, or the servers
       for Kerberos 4 ticket conversion.

       First  a  handle  to   a   particular   service   is   obtained   by   calling   krb5_krbhst_init()   (or
       krb5_krbhst_init_flags())  with  the realm of interest and the type of service to lookup. The type can be
       one of:

             KRB5_KRBHST_KDC
             KRB5_KRBHST_ADMIN
             KRB5_KRBHST_CHANGEPW
             KRB5_KRBHST_KRB524

       The handle is returned to the caller, and should be passed to the other functions.

       The flag argument to krb5_krbhst_init_flags is the same flags as krb5_send_to_kdc_flags() uses.  Possible
       values are:

             KRB5_KRBHST_FLAGS_MASTER     only talk to master (readwrite) KDC
             KRB5_KRBHST_FLAGS_LARGE_MSG  this is a large message, so use transport that can handle that.

       For each call to krb5_krbhst_next() information on a new host is returned. The former function returns in
       host a pointer to a structure containing information about the host,  such  as  protocol,  hostname,  and
       port:

             typedef struct krb5_krbhst_info {
                 enum { KRB5_KRBHST_UDP,
                        KRB5_KRBHST_TCP,
                        KRB5_KRBHST_HTTP } proto;
                 unsigned short port;
                 struct addrinfo *ai;
                 struct krb5_krbhst_info *next;
                 char hostname[1];
             } krb5_krbhst_info;

       The related function, krb5_krbhst_next_as_string(), return the same information as a URL-like string.

       When there are no more hosts, these functions return KRB5_KDC_UNREACH.

       To  re-iterate  over  all  hosts,  call  krb5_krbhst_reset() and the next call to krb5_krbhst_next() will
       return the first host.

       When done with the handle, krb5_krbhst_free() should be called.

       To use a krb5_krbhst_info, there are  two  functions:  krb5_krbhst_format_string()  that  will  return  a
       printable representation of that struct and krb5_krbhst_get_addrinfo() that will return a struct addrinfo
       that can then be used for communicating with the server mentioned.

EXAMPLES

       The following code will print the KDCs of the realm “MY.REALM”:

             krb5_krbhst_handle handle;
             char host[MAXHOSTNAMELEN];
             krb5_krbhst_init(context, "MY.REALM", KRB5_KRBHST_KDC, &handle);
             while(krb5_krbhst_next_as_string(context, handle,
                                              host, sizeof(host)) == 0)
                 printf("%s\n", host);
             krb5_krbhst_free(context, handle);

SEE ALSO

       getaddrinfo(3), krb5_get_krbhst(3), krb5_send_to_kdc_flags(3)

HISTORY

       These functions first appeared in Heimdal 0.3g.

HEIMDAL                                           May 10, 2005                               KRB5_KRBHST_INIT(3)