OpenBSD-4.6/kerberosV/src/lib/krb5/krbhst.c
/*
* Copyright (c) 2001 - 2003 Kungliga Tekniska Högskolan
* (Royal Institute of Technology, Stockholm, Sweden).
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* 3. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include "krb5_locl.h"
#include <resolve.h>
RCSID("$KTH: krbhst.c,v 1.51 2005/05/20 09:09:42 lha Exp $");
static int
string_to_proto(const char *string)
{
if(strcasecmp(string, "udp") == 0)
return KRB5_KRBHST_UDP;
else if(strcasecmp(string, "tcp") == 0)
return KRB5_KRBHST_TCP;
else if(strcasecmp(string, "http") == 0)
return KRB5_KRBHST_HTTP;
return -1;
}
/*
* set `res' and `count' to the result of looking up SRV RR in DNS for
* `proto', `proto', `realm' using `dns_type'.
* if `port' != 0, force that port number
*/
static krb5_error_code
srv_find_realm(krb5_context context, krb5_krbhst_info ***res, int *count,
const char *realm, const char *dns_type,
const char *proto, const char *service, int port)
{
char domain[1024];
struct dns_reply *r;
struct resource_record *rr;
int num_srv;
int proto_num;
int def_port;
*res = NULL;
*count = 0;
proto_num = string_to_proto(proto);
if(proto_num < 0) {
krb5_set_error_string(context, "unknown protocol `%s'", proto);
return EINVAL;
}
if(proto_num == KRB5_KRBHST_HTTP)
def_port = ntohs(krb5_getportbyname (context, "http", "tcp", 80));
else if(port == 0)
def_port = ntohs(krb5_getportbyname (context, service, proto, 88));
else
def_port = port;
snprintf(domain, sizeof(domain), "_%s._%s.%s.", service, proto, realm);
r = dns_lookup(domain, dns_type);
if(r == NULL)
return KRB5_KDC_UNREACH;
for(num_srv = 0, rr = r->head; rr; rr = rr->next)
if(rr->type == T_SRV)
num_srv++;
*res = malloc(num_srv * sizeof(**res));
if(*res == NULL) {
dns_free_data(r);
krb5_set_error_string(context, "malloc: out of memory");
return ENOMEM;
}
dns_srv_order(r);
for(num_srv = 0, rr = r->head; rr; rr = rr->next)
if(rr->type == T_SRV) {
krb5_krbhst_info *hi;
size_t len = strlen(rr->u.srv->target);
hi = calloc(1, sizeof(*hi) + len);
if(hi == NULL) {
dns_free_data(r);
while(--num_srv >= 0)
free((*res)[num_srv]);
free(*res);
*res = NULL;
return ENOMEM;
}
(*res)[num_srv++] = hi;
hi->proto = proto_num;
hi->def_port = def_port;
if (port != 0)
hi->port = port;
else
hi->port = rr->u.srv->port;
strlcpy(hi->hostname, rr->u.srv->target, len + 1);
}
*count = num_srv;
dns_free_data(r);
return 0;
}
struct krb5_krbhst_data {
char *realm;
unsigned int flags;
int def_port;
int port; /* hardwired port number if != 0 */
#define KD_CONFIG 1
#define KD_SRV_UDP 2
#define KD_SRV_TCP 4
#define KD_SRV_HTTP 8
#define KD_FALLBACK 16
#define KD_CONFIG_EXISTS 32
#define KD_LARGE_MSG 64
krb5_error_code (*get_next)(krb5_context, struct krb5_krbhst_data *,
krb5_krbhst_info**);
unsigned int fallback_count;
struct krb5_krbhst_info *hosts, **index, **end;
};
static krb5_boolean
krbhst_empty(const struct krb5_krbhst_data *kd)
{
return kd->index == &kd->hosts;
}
/*
* Return the default protocol for the `kd' (either TCP or UDP)
*/
static int
krbhst_get_default_proto(struct krb5_krbhst_data *kd)
{
if (kd->flags & KD_LARGE_MSG)
return KRB5_KRBHST_TCP;
return KRB5_KRBHST_UDP;
}
/*
* parse `spec' into a krb5_krbhst_info, defaulting the port to `def_port'
* and forcing it to `port' if port != 0
*/
static struct krb5_krbhst_info*
parse_hostspec(krb5_context context, struct krb5_krbhst_data *kd,
const char *spec, int def_port, int port)
{
const char *p = spec;
struct krb5_krbhst_info *hi;
hi = calloc(1, sizeof(*hi) + strlen(spec));
if(hi == NULL)
return NULL;
hi->proto = krbhst_get_default_proto(kd);
if(strncmp(p, "http://", 7) == 0){
hi->proto = KRB5_KRBHST_HTTP;
p += 7;
} else if(strncmp(p, "http/", 5) == 0) {
hi->proto = KRB5_KRBHST_HTTP;
p += 5;
def_port = ntohs(krb5_getportbyname (context, "http", "tcp", 80));
}else if(strncmp(p, "tcp/", 4) == 0){
hi->proto = KRB5_KRBHST_TCP;
p += 4;
} else if(strncmp(p, "udp/", 4) == 0) {
p += 4;
}
if(strsep_copy(&p, ":", hi->hostname, strlen(spec) + 1) < 0) {
free(hi);
return NULL;
}
/* get rid of trailing /, and convert to lower case */
hi->hostname[strcspn(hi->hostname, "/")] = '\0';
strlwr(hi->hostname);
hi->port = hi->def_port = def_port;
if(p != NULL) {
char *end;
hi->port = strtol(p, &end, 0);
if(end == p) {
free(hi);
return NULL;
}
}
if (port)
hi->port = port;
return hi;
}
static void
free_krbhst_info(krb5_krbhst_info *hi)
{
if (hi->ai != NULL)
freeaddrinfo(hi->ai);
free(hi);
}
static void
append_host_hostinfo(struct krb5_krbhst_data *kd, struct krb5_krbhst_info *host)
{
struct krb5_krbhst_info *h;
for(h = kd->hosts; h; h = h->next)
if(h->proto == host->proto &&
h->port == host->port &&
strcmp(h->hostname, host->hostname) == 0) {
free_krbhst_info(host);
return;
}
*kd->end = host;
kd->end = &host->next;
}
static krb5_error_code
append_host_string(krb5_context context, struct krb5_krbhst_data *kd,
const char *host, int def_port, int port)
{
struct krb5_krbhst_info *hi;
hi = parse_hostspec(context, kd, host, def_port, port);
if(hi == NULL)
return ENOMEM;
append_host_hostinfo(kd, hi);
return 0;
}
/*
* return a readable representation of `host' in `hostname, hostlen'
*/
krb5_error_code KRB5_LIB_FUNCTION
krb5_krbhst_format_string(krb5_context context, const krb5_krbhst_info *host,
char *hostname, size_t hostlen)
{
const char *proto = "";
char portstr[7] = "";
if(host->proto == KRB5_KRBHST_TCP)
proto = "tcp/";
else if(host->proto == KRB5_KRBHST_HTTP)
proto = "http://";
if(host->port != host->def_port)
snprintf(portstr, sizeof(portstr), ":%d", host->port);
snprintf(hostname, hostlen, "%s%s%s", proto, host->hostname, portstr);
return 0;
}
/*
* create a getaddrinfo `hints' based on `proto'
*/
static void
make_hints(struct addrinfo *hints, int proto)
{
memset(hints, 0, sizeof(*hints));
hints->ai_family = AF_UNSPEC;
switch(proto) {
case KRB5_KRBHST_UDP :
hints->ai_socktype = SOCK_DGRAM;
break;
case KRB5_KRBHST_HTTP :
case KRB5_KRBHST_TCP :
hints->ai_socktype = SOCK_STREAM;
break;
}
}
/*
* return an `struct addrinfo *' in `ai' corresponding to the information
* in `host'. free:ing is handled by krb5_krbhst_free.
*/
krb5_error_code KRB5_LIB_FUNCTION
krb5_krbhst_get_addrinfo(krb5_context context, krb5_krbhst_info *host,
struct addrinfo **ai)
{
struct addrinfo hints;
char portstr[NI_MAXSERV];
int ret;
if (host->ai == NULL) {
make_hints(&hints, host->proto);
snprintf (portstr, sizeof(portstr), "%d", host->port);
ret = getaddrinfo(host->hostname, portstr, &hints, &host->ai);
if (ret)
return krb5_eai_to_heim_errno(ret, errno);
}
*ai = host->ai;
return 0;
}
static krb5_boolean
get_next(struct krb5_krbhst_data *kd, krb5_krbhst_info **host)
{
struct krb5_krbhst_info *hi = *kd->index;
if(hi != NULL) {
*host = hi;
kd->index = &(*kd->index)->next;
return TRUE;
}
return FALSE;
}
static void
srv_get_hosts(krb5_context context, struct krb5_krbhst_data *kd,
const char *proto, const char *service)
{
krb5_krbhst_info **res;
int count, i;
if (srv_find_realm(context, &res, &count, kd->realm, "SRV", proto, service,
kd->port))
return;
for(i = 0; i < count; i++)
append_host_hostinfo(kd, res[i]);
free(res);
}
/*
* read the configuration for `conf_string', defaulting to kd->def_port and
* forcing it to `kd->port' if kd->port != 0
*/
static void
config_get_hosts(krb5_context context, struct krb5_krbhst_data *kd,
const char *conf_string)
{
int i;
char **hostlist;
hostlist = krb5_config_get_strings(context, NULL,
"realms", kd->realm, conf_string, NULL);
if(hostlist == NULL)
return;
kd->flags |= KD_CONFIG_EXISTS;
for(i = 0; hostlist && hostlist[i] != NULL; i++)
append_host_string(context, kd, hostlist[i], kd->def_port, kd->port);
krb5_config_free_strings(hostlist);
}
/*
* as a fallback, look for `serv_string.kd->realm' (typically
* kerberos.REALM, kerberos-1.REALM, ...
* `port' is the default port for the service, and `proto' the
* protocol
*/
static krb5_error_code
fallback_get_hosts(krb5_context context, struct krb5_krbhst_data *kd,
const char *serv_string, int port, int proto)
{
char *host;
int ret;
struct addrinfo *ai;
struct addrinfo hints;
char portstr[NI_MAXSERV];
if(kd->fallback_count == 0)
asprintf(&host, "%s.%s.", serv_string, kd->realm);
else
asprintf(&host, "%s-%d.%s.",
serv_string, kd->fallback_count, kd->realm);
if (host == NULL)
return ENOMEM;
make_hints(&hints, proto);
snprintf(portstr, sizeof(portstr), "%d", port);
ret = getaddrinfo(host, portstr, &hints, &ai);
if (ret) {
/* no more hosts, so we're done here */
free(host);
kd->flags |= KD_FALLBACK;
} else {
struct krb5_krbhst_info *hi;
size_t hostlen = strlen(host);
hi = calloc(1, sizeof(*hi) + hostlen);
if(hi == NULL) {
free(host);
return ENOMEM;
}
hi->proto = proto;
hi->port = hi->def_port = port;
hi->ai = ai;
memmove(hi->hostname, host, hostlen - 1);
hi->hostname[hostlen - 1] = '\0';
free(host);
append_host_hostinfo(kd, hi);
kd->fallback_count++;
}
return 0;
}
static krb5_error_code
kdc_get_next(krb5_context context,
struct krb5_krbhst_data *kd,
krb5_krbhst_info **host)
{
krb5_error_code ret;
if((kd->flags & KD_CONFIG) == 0) {
config_get_hosts(context, kd, "kdc");
kd->flags |= KD_CONFIG;
if(get_next(kd, host))
return 0;
}
if (kd->flags & KD_CONFIG_EXISTS)
return KRB5_KDC_UNREACH; /* XXX */
if(context->srv_lookup) {
if((kd->flags & KD_SRV_UDP) == 0 && (kd->flags & KD_LARGE_MSG) == 0) {
srv_get_hosts(context, kd, "udp", "kerberos");
kd->flags |= KD_SRV_UDP;
if(get_next(kd, host))
return 0;
}
if((kd->flags & KD_SRV_TCP) == 0) {
srv_get_hosts(context, kd, "tcp", "kerberos");
kd->flags |= KD_SRV_TCP;
if(get_next(kd, host))
return 0;
}
if((kd->flags & KD_SRV_HTTP) == 0) {
srv_get_hosts(context, kd, "http", "kerberos");
kd->flags |= KD_SRV_HTTP;
if(get_next(kd, host))
return 0;
}
}
while((kd->flags & KD_FALLBACK) == 0) {
ret = fallback_get_hosts(context, kd, "kerberos",
kd->def_port,
krbhst_get_default_proto(kd));
if(ret)
return ret;
if(get_next(kd, host))
return 0;
}
return KRB5_KDC_UNREACH; /* XXX */
}
static krb5_error_code
admin_get_next(krb5_context context,
struct krb5_krbhst_data *kd,
krb5_krbhst_info **host)
{
krb5_error_code ret;
if((kd->flags & KD_CONFIG) == 0) {
config_get_hosts(context, kd, "admin_server");
kd->flags |= KD_CONFIG;
if(get_next(kd, host))
return 0;
}
if (kd->flags & KD_CONFIG_EXISTS)
return KRB5_KDC_UNREACH; /* XXX */
if(context->srv_lookup) {
if((kd->flags & KD_SRV_TCP) == 0) {
srv_get_hosts(context, kd, "tcp", "kerberos-adm");
kd->flags |= KD_SRV_TCP;
if(get_next(kd, host))
return 0;
}
}
if (krbhst_empty(kd)
&& (kd->flags & KD_FALLBACK) == 0) {
ret = fallback_get_hosts(context, kd, "kerberos",
kd->def_port,
krbhst_get_default_proto(kd));
if(ret)
return ret;
kd->flags |= KD_FALLBACK;
if(get_next(kd, host))
return 0;
}
return KRB5_KDC_UNREACH; /* XXX */
}
static krb5_error_code
kpasswd_get_next(krb5_context context,
struct krb5_krbhst_data *kd,
krb5_krbhst_info **host)
{
krb5_error_code ret;
if((kd->flags & KD_CONFIG) == 0) {
config_get_hosts(context, kd, "kpasswd_server");
kd->flags |= KD_CONFIG;
if(get_next(kd, host))
return 0;
}
if (kd->flags & KD_CONFIG_EXISTS)
return KRB5_KDC_UNREACH; /* XXX */
if(context->srv_lookup) {
if((kd->flags & KD_SRV_UDP) == 0) {
srv_get_hosts(context, kd, "udp", "kpasswd");
kd->flags |= KD_SRV_UDP;
if(get_next(kd, host))
return 0;
}
if((kd->flags & KD_SRV_TCP) == 0) {
srv_get_hosts(context, kd, "tcp", "kpasswd");
kd->flags |= KD_SRV_TCP;
if(get_next(kd, host))
return 0;
}
}
/* no matches -> try admin */
if (krbhst_empty(kd)) {
kd->flags = 0;
kd->port = kd->def_port;
kd->get_next = admin_get_next;
ret = (*kd->get_next)(context, kd, host);
if (ret == 0)
(*host)->proto = krbhst_get_default_proto(kd);
return ret;
}
return KRB5_KDC_UNREACH; /* XXX */
}
static krb5_error_code
krb524_get_next(krb5_context context,
struct krb5_krbhst_data *kd,
krb5_krbhst_info **host)
{
if((kd->flags & KD_CONFIG) == 0) {
config_get_hosts(context, kd, "krb524_server");
if(get_next(kd, host))
return 0;
kd->flags |= KD_CONFIG;
}
if (kd->flags & KD_CONFIG_EXISTS)
return KRB5_KDC_UNREACH; /* XXX */
if(context->srv_lookup) {
if((kd->flags & KD_SRV_UDP) == 0) {
srv_get_hosts(context, kd, "udp", "krb524");
kd->flags |= KD_SRV_UDP;
if(get_next(kd, host))
return 0;
}
if((kd->flags & KD_SRV_TCP) == 0) {
srv_get_hosts(context, kd, "tcp", "krb524");
kd->flags |= KD_SRV_TCP;
if(get_next(kd, host))
return 0;
}
}
/* no matches -> try kdc */
if (krbhst_empty(kd)) {
kd->flags = 0;
kd->port = kd->def_port;
kd->get_next = kdc_get_next;
return (*kd->get_next)(context, kd, host);
}
return KRB5_KDC_UNREACH; /* XXX */
}
static struct krb5_krbhst_data*
common_init(krb5_context context,
const char *realm,
int flags)
{
struct krb5_krbhst_data *kd;
if((kd = calloc(1, sizeof(*kd))) == NULL)
return NULL;
if((kd->realm = strdup(realm)) == NULL) {
free(kd);
return NULL;
}
if (flags & KRB5_KRBHST_FLAGS_LARGE_MSG)
kd->flags |= KD_LARGE_MSG;
kd->end = kd->index = &kd->hosts;
return kd;
}
/*
* initialize `handle' to look for hosts of type `type' in realm `realm'
*/
krb5_error_code KRB5_LIB_FUNCTION
krb5_krbhst_init(krb5_context context,
const char *realm,
unsigned int type,
krb5_krbhst_handle *handle)
{
return krb5_krbhst_init_flags(context, realm, type, 0, handle);
}
krb5_error_code KRB5_LIB_FUNCTION
krb5_krbhst_init_flags(krb5_context context,
const char *realm,
unsigned int type,
int flags,
krb5_krbhst_handle *handle)
{
struct krb5_krbhst_data *kd;
krb5_error_code (*get_next)(krb5_context, struct krb5_krbhst_data *,
krb5_krbhst_info **);
int def_port;
switch(type) {
case KRB5_KRBHST_KDC:
get_next = kdc_get_next;
def_port = ntohs(krb5_getportbyname (context, "kerberos", "udp", 88));
break;
case KRB5_KRBHST_ADMIN:
get_next = admin_get_next;
def_port = ntohs(krb5_getportbyname (context, "kerberos-adm",
"tcp", 749));
break;
case KRB5_KRBHST_CHANGEPW:
get_next = kpasswd_get_next;
def_port = ntohs(krb5_getportbyname (context, "kpasswd", "udp",
KPASSWD_PORT));
break;
case KRB5_KRBHST_KRB524:
get_next = krb524_get_next;
def_port = ntohs(krb5_getportbyname (context, "krb524", "udp", 4444));
break;
default:
krb5_set_error_string(context, "unknown krbhst type (%u)", type);
return ENOTTY;
}
if((kd = common_init(context, realm, flags)) == NULL)
return ENOMEM;
kd->get_next = get_next;
kd->def_port = def_port;
*handle = kd;
return 0;
}
/*
* return the next host information from `handle' in `host'
*/
krb5_error_code KRB5_LIB_FUNCTION
krb5_krbhst_next(krb5_context context,
krb5_krbhst_handle handle,
krb5_krbhst_info **host)
{
if(get_next(handle, host))
return 0;
return (*handle->get_next)(context, handle, host);
}
/*
* return the next host information from `handle' as a host name
* in `hostname' (or length `hostlen)
*/
krb5_error_code KRB5_LIB_FUNCTION
krb5_krbhst_next_as_string(krb5_context context,
krb5_krbhst_handle handle,
char *hostname,
size_t hostlen)
{
krb5_error_code ret;
krb5_krbhst_info *host;
ret = krb5_krbhst_next(context, handle, &host);
if(ret)
return ret;
return krb5_krbhst_format_string(context, host, hostname, hostlen);
}
void KRB5_LIB_FUNCTION
krb5_krbhst_reset(krb5_context context, krb5_krbhst_handle handle)
{
handle->index = &handle->hosts;
}
void KRB5_LIB_FUNCTION
krb5_krbhst_free(krb5_context context, krb5_krbhst_handle handle)
{
krb5_krbhst_info *h, *next;
if (handle == NULL)
return;
for (h = handle->hosts; h != NULL; h = next) {
next = h->next;
free_krbhst_info(h);
}
free(handle->realm);
free(handle);
}
/* backwards compatibility ahead */
static krb5_error_code
gethostlist(krb5_context context, const char *realm,
unsigned int type, char ***hostlist)
{
krb5_error_code ret;
int nhost = 0;
krb5_krbhst_handle handle;
char host[MAXHOSTNAMELEN];
krb5_krbhst_info *hostinfo;
ret = krb5_krbhst_init(context, realm, type, &handle);
if (ret)
return ret;
while(krb5_krbhst_next(context, handle, &hostinfo) == 0)
nhost++;
if(nhost == 0)
return KRB5_KDC_UNREACH;
*hostlist = calloc(nhost + 1, sizeof(**hostlist));
if(*hostlist == NULL) {
krb5_krbhst_free(context, handle);
return ENOMEM;
}
krb5_krbhst_reset(context, handle);
nhost = 0;
while(krb5_krbhst_next_as_string(context, handle,
host, sizeof(host)) == 0) {
if(((*hostlist)[nhost++] = strdup(host)) == NULL) {
krb5_free_krbhst(context, *hostlist);
krb5_krbhst_free(context, handle);
return ENOMEM;
}
}
(*hostlist)[nhost++] = NULL;
krb5_krbhst_free(context, handle);
return 0;
}
/*
* return an malloced list of kadmin-hosts for `realm' in `hostlist'
*/
krb5_error_code KRB5_LIB_FUNCTION
krb5_get_krb_admin_hst (krb5_context context,
const krb5_realm *realm,
char ***hostlist)
{
return gethostlist(context, *realm, KRB5_KRBHST_ADMIN, hostlist);
}
/*
* return an malloced list of changepw-hosts for `realm' in `hostlist'
*/
krb5_error_code KRB5_LIB_FUNCTION
krb5_get_krb_changepw_hst (krb5_context context,
const krb5_realm *realm,
char ***hostlist)
{
return gethostlist(context, *realm, KRB5_KRBHST_CHANGEPW, hostlist);
}
/*
* return an malloced list of 524-hosts for `realm' in `hostlist'
*/
krb5_error_code KRB5_LIB_FUNCTION
krb5_get_krb524hst (krb5_context context,
const krb5_realm *realm,
char ***hostlist)
{
return gethostlist(context, *realm, KRB5_KRBHST_KRB524, hostlist);
}
/*
* return an malloced list of KDC's for `realm' in `hostlist'
*/
krb5_error_code KRB5_LIB_FUNCTION
krb5_get_krbhst (krb5_context context,
const krb5_realm *realm,
char ***hostlist)
{
return gethostlist(context, *realm, KRB5_KRBHST_KDC, hostlist);
}
/*
* free all the memory allocated in `hostlist'
*/
krb5_error_code KRB5_LIB_FUNCTION
krb5_free_krbhst (krb5_context context,
char **hostlist)
{
char **p;
for (p = hostlist; *p; ++p)
free (*p);
free (hostlist);
return 0;
}