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/*
* This program is is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or (at
* your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
*/
/**
* $Id$
* @file rlm_dhcp.c
* @brief Will contain dhcp listener code.
*
* @copyright 2012 The FreeRADIUS server project
*/
RCSID("$Id$")
#include <freeradius-devel/libradius.h>
#include <freeradius-devel/radiusd.h>
#include <freeradius-devel/modules.h>
#include <freeradius-devel/dhcp.h>
#include <ctype.h>
#define PW_DHCP_PARAMETER_REQUEST_LIST 55
/*
* Define a structure for our module configuration.
*
* These variables do not need to be in a structure, but it's
* a lot cleaner to do so, and a pointer to the structure can
* be used as the instance handle.
*/
typedef struct rlm_dhcp_t {
int nothing;
} rlm_dhcp_t;
/*
* Allow single attribute values to be retrieved from the dhcp.
*/
static ssize_t dhcp_options_xlat(UNUSED void *instance, REQUEST *request,
char const *fmt, char *out, size_t freespace)
{
vp_cursor_t cursor, src_cursor;
vp_tmpl_t src;
VALUE_PAIR *vp, *head = NULL;
int decoded = 0;
ssize_t slen;
while (isspace((uint8_t) *fmt)) fmt++;
slen = tmpl_from_attr_str(&src, fmt, REQUEST_CURRENT, PAIR_LIST_REQUEST, false, false);
if (slen <= 0) {
REMARKER(fmt, slen, fr_strerror());
error:
*out = '\0';
return -1;
}
if (src.type != TMPL_TYPE_ATTR) {
REDEBUG("dhcp_options cannot operate on a %s", fr_int2str(tmpl_names, src.type, "<INVALID>"));
goto error;
}
if (src.tmpl_da->type != PW_TYPE_OCTETS) {
REDEBUG("dhcp_options got a %s attribute needed octets",
fr_int2str(dict_attr_types, src.tmpl_da->type, "<INVALID>"));
goto error;
}
for (vp = tmpl_cursor_init(NULL, &src_cursor, request, &src);
vp;
vp = tmpl_cursor_next(&src_cursor, &src)) {
/*
* @fixme: we should pass in a cursor, then decoding multiple
* source attributes can be made atomic.
*/
if ((fr_dhcp_decode_options(request->packet, &head, vp->vp_octets, vp->vp_length) < 0) || (!head)) {
RWDEBUG("DHCP option decoding failed: %s", fr_strerror());
goto error;
}
for (vp = fr_cursor_init(&cursor, &head);
vp;
vp = fr_cursor_next(&cursor)) {
rdebug_pair(L_DBG_LVL_2, request, vp, "dhcp_options: ");
decoded++;
}
fr_pair_list_move(request->packet, &(request->packet->vps), &head, T_OP_ADD);
/* Free any unmoved pairs */
fr_pair_list_free(&head);
}
snprintf(out, freespace, "%i", decoded);
return strlen(out);
}
static ssize_t dhcp_xlat(UNUSED void *instance, REQUEST *request, char const *fmt, char *out, size_t freespace)
{
vp_cursor_t cursor;
VALUE_PAIR *head = NULL, *vp;
uint8_t binbuf[1024];
uint8_t *p = binbuf, *end = p + sizeof(binbuf);
ssize_t slen;
while (isspace((uint8_t) *fmt)) fmt++;
if ((radius_copy_vp(request, &head, request, fmt) < 0) || !head) {
*out = '\0';
return 0;
}
fr_cursor_init(&cursor, &head);
while ((vp = fr_cursor_current(&cursor))) {
slen = fr_dhcp_encode_option(request, p, end - p, &cursor);
talloc_free(vp);
if (slen <= 0) {
REDEBUG("DHCP option encoding failed: %s", fr_strerror());
return -1;
}
p += (size_t)slen;
}
if ((size_t)(((p - binbuf) * 2) + 1) > freespace) {
REDEBUG("DHCP option encoding failed: Output buffer exhausted, needed %zd bytes, have %zd bytes",
((p - binbuf) * 2) + 1, freespace);
return -1;
}
return fr_bin2hex(out, binbuf, (p - binbuf));
}
/*
* Instantiate the module.
*/
static int mod_bootstrap(UNUSED CONF_SECTION *conf, void *instance)
{
rlm_dhcp_t *inst = instance;
DICT_ATTR const *da;
xlat_register("dhcp_options", dhcp_options_xlat, NULL, inst);
xlat_register("dhcp", dhcp_xlat, NULL, inst);
/*
* Fixup dictionary entry for DHCP-Paramter-Request-List adding all the options
*/
da = dict_attrbyvalue(PW_DHCP_PARAMETER_REQUEST_LIST, DHCP_MAGIC_VENDOR);
if (da) {
DICT_ATTR const *value;
int i;
/* No padding or termination options */
DEBUG3("Adding values for %s", da->name);
for (i = 1; i < 255; i++) {
value = dict_attrbyvalue(i, DHCP_MAGIC_VENDOR);
if (!value) {
DEBUG3("No DHCP RFC space attribute at %i", i);
continue;
}
DEBUG3("Adding %s value %i %s", da->name, i, value->name);
if (dict_addvalue(value->name, da->name, i) < 0) {
DEBUG3("Failed adding value: %s", fr_strerror());
}
}
}
return 0;
}
/*
* The module name should be the only globally exported symbol.
* That is, everything else should be 'static'.
*
* If the module needs to temporarily modify it's instantiation
* data, the type should be changed to RLM_TYPE_THREAD_UNSAFE.
* The server will then take care of ensuring that the module
* is single-threaded.
*/
extern module_t rlm_dhcp;
module_t rlm_dhcp = {
.magic = RLM_MODULE_INIT,
.name = "dhcp",
.inst_size = sizeof(rlm_dhcp_t),
.bootstrap = mod_bootstrap,
};
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