KRB5_KRBHST_INIT(3) BSD Library Functions Manual KRB5_KRBHST_INIT(3)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 par‐
ticular realm and service. The service type can be the KDCs, the adminis‐
trative servers, the password changing servers, or the servers for Ker‐
beros 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 inter‐
est 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 trans‐
port 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 men‐
tioned.
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 ALSOgetaddrinfo(3), krb5_get_krbhst(3), krb5_send_to_kdc_flags(3)HISTORY
These functions first appeared in Heimdal 0.3g.
HEIMDAL May 10, 2005 HEIMDAL
