DOKK / manpages / debian 12 / heimdal-dev / krb5_krbhst_next.3.en
KRB5_KRBHST_INIT(3) Library Functions Manual KRB5_KRBHST_INIT(3)

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_addrinfolookup Kerberos KDC hosts

Kerberos 5 Library (libkrb5, -lkrb5)

#include <krb5.h>

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

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

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

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

krb5_krbhst_reset(krb5_context context, krb5_krbhst_handle handle);

krb5_krbhst_free(krb5_context context, krb5_krbhst_handle handle);

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

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

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 () (or ()) with the realm of interest and the type of service to lookup. The type can be one of:


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 () uses. Possible values are:

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

For each call to () 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_HTTP } proto;
    unsigned short port;
    struct addrinfo *ai;
    struct krb5_krbhst_info *next;
    char hostname[1];
} krb5_krbhst_info;

The related function, (), 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 () and the next call to krb5_krbhst_next() will return the first host.

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

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

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

krb5_krbhst_handle handle;
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);

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

These functions first appeared in Heimdal 0.3g.

May 10, 2005 HEIMDAL