Man page - krb5_krbhst_format_string(3)

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Manual

KRB5_KRBHST_INIT (3) 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 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)