diff options
Diffstat (limited to 'src/modules/proto_dhcp/rlm_dhcp.c')
| -rw-r--r-- | src/modules/proto_dhcp/rlm_dhcp.c | 203 |
1 files changed, 203 insertions, 0 deletions
diff --git a/src/modules/proto_dhcp/rlm_dhcp.c b/src/modules/proto_dhcp/rlm_dhcp.c new file mode 100644 index 0000000..1cd73ff --- /dev/null +++ b/src/modules/proto_dhcp/rlm_dhcp.c @@ -0,0 +1,203 @@ +/* + * 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((int) *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((int) *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, +}; |