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.
