krb5_krbhst_next_as_string (3) - Linux Manuals


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


Kerberos 5 Library (libkrb5, -lkrb5)


In krb5.h Ft krb5_error_code Fn krb5_krbhst_init krb5_context context const char *realm unsigned int type krb5_krbhst_handle *handle Ft krb5_error_code Fn krb5_krbhst_init_flags krb5_context context const char *realm unsigned int type int flags krb5_krbhst_handle *handle Ft krb5_error_code Fn krb5_krbhst_next krb5_context context krb5_krbhst_handle handle krb5_krbhst_info **host Ft krb5_error_code Fn krb5_krbhst_next_as_string krb5_context context krb5_krbhst_handle handle char *hostname size_t hostlen Ft void Fn krb5_krbhst_reset krb5_context context krb5_krbhst_handle handle Ft void Fn krb5_krbhst_free krb5_context context krb5_krbhst_handle handle Ft krb5_error_code Fn krb5_krbhst_format_string krb5_context context const krb5_krbhst_info *host char *hostname size_t hostlen Ft krb5_error_code Fn 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 Fn krb5_krbhst_init (or Fn krb5_krbhst_init_flags ) with the Fa realm of interest and the type of service to lookup. The Fa type can be one of:


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

The Fa flag argument to krb5_krbhst_init_flags is the same flags as Fn krb5_send_to_kdc_flags 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 Fn krb5_krbhst_next information on a new host is returned. The former function returns in Fa 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, Fn 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 Fn krb5_krbhst_reset and the next call to Fn krb5_krbhst_next will return the first host.

When done with the handle, Fn krb5_krbhst_free should be called.

To use a krb5_krbhst_info there are two functions: Fn krb5_krbhst_format_string that will return a printable representation of that struct and Fn krb5_krbhst_get_addrinfo 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);


These functions first appeared in Heimdal 0.3g.


getaddrinfo(3), krb5_get_krbhst3, krb5_send_to_kdc_flags3