diff options
Diffstat (limited to 'src/modules/rlm_json/rlm_json.c')
| -rw-r--r-- | src/modules/rlm_json/rlm_json.c | 237 |
1 files changed, 237 insertions, 0 deletions
diff --git a/src/modules/rlm_json/rlm_json.c b/src/modules/rlm_json/rlm_json.c new file mode 100644 index 0000000..9cf99d8 --- /dev/null +++ b/src/modules/rlm_json/rlm_json.c @@ -0,0 +1,237 @@ +/* + * 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_json.c + * @brief Parses JSON responses + * + * @author Matthew Newton + * @author Arran Cudbard-Bell + * + * @copyright 2015 Arran Cudbard-Bell (a.cudbardb@freeradius.org) + * @copyright 2015,2021 Network RADIUS SARL (legal@networkradius.com) + * @copyright 2015 The FreeRADIUS Server Project + */ +RCSID("$Id$") + +#include <freeradius-devel/radiusd.h> +#include <freeradius-devel/modules.h> + +#include "json.h" +#include <ctype.h> + +#ifndef HAVE_JSON +# error "rlm_json should not be built unless json-c is available" +#endif + + +static CONF_PARSER const json_format_attr_config[] = { + { "prefix", FR_CONF_OFFSET(PW_TYPE_STRING, rlm_json_t, attr_prefix), NULL }, + + CONF_PARSER_TERMINATOR +}; + +static CONF_PARSER const json_format_value_config[] = { + { "single_value_as_array", FR_CONF_OFFSET(PW_TYPE_BOOLEAN, rlm_json_t, value_as_array), "no" }, + { "enum_as_integer", FR_CONF_OFFSET(PW_TYPE_BOOLEAN, rlm_json_t, enum_as_int), "no" }, + { "always_string", FR_CONF_OFFSET(PW_TYPE_BOOLEAN, rlm_json_t, always_string), "no" }, + + CONF_PARSER_TERMINATOR +}; + +static CONF_PARSER const fr_json_format_config[] = { + { "output_mode", FR_CONF_OFFSET(PW_TYPE_STRING, rlm_json_t, output_mode_str), "object" }, + { "attribute", FR_CONF_POINTER(PW_TYPE_SUBSECTION, NULL), (void const *) json_format_attr_config }, + { "value", FR_CONF_POINTER(PW_TYPE_SUBSECTION, NULL), (void const *) json_format_value_config }, + + CONF_PARSER_TERMINATOR +}; + +static CONF_PARSER const module_config[] = { + { "encode", FR_CONF_POINTER(PW_TYPE_SUBSECTION, NULL), (void const *) fr_json_format_config }, + + CONF_PARSER_TERMINATOR +}; + + +/** Convert given attributes to a JSON document + * + * Usage is `%{json_encode:attr tmpl list}` + * + * @ingroup xlat_functions + * + * @param instance module instance + * @param request the current request + * @param fmt input to the xlat + * @param out where to write the output + * @param outlen space available for the output + * @return length of output generated + */ +static ssize_t json_encode_xlat(UNUSED void * instance, REQUEST *request, char const *fmt, + char *out, size_t outlen) +{ + rlm_json_t const *inst = instance; + ssize_t slen; + vp_tmpl_t *vpt = NULL; + VALUE_PAIR *json_vps = NULL, *vps; + bool negate; + char const *p = fmt; + char *json_str = NULL; + char *buf; + + + /* + * Iterate through the list of attribute templates in the xlat. For each + * one we either add it to the list of attributes for the JSON document + * or, if prefixed with '!', remove from the JSON list. + */ + + p = fmt; + + while (isspace((uint8_t) *p)) p++; + if (*p == '\0') return -1; + + while (*p) { + while (isspace((uint8_t) *p)) p++; + + if (*p == '\0') break; + + negate = false; + + /* Check if we should be removing attributes */ + if (*p == '!') { + p++; + negate = true; + } + + if (*p == '\0') { + /* May happen e.g. with '!' on its own at the end */ + REMARKER(fmt, (p - fmt), "Missing attribute name"); + error: + fr_pair_list_free(&json_vps); + talloc_free(vpt); + return -1; + } + + + /* Decode next attr template */ + slen = tmpl_afrom_attr_substr(request, &vpt, p, REQUEST_CURRENT, PAIR_LIST_REQUEST, false, false); + + if (slen <= 0) { + REMARKER(fmt, (p - fmt) -slen, fr_strerror()); + goto error; + } + + /* + * Get attributes from the template. + * Missing attribute isn't an error (so -1, not 0). + */ + if (tmpl_copy_vps(request, &vps, request, vpt) < -1) { + REDEBUG("Error copying attributes"); + goto error; + } + + if (negate) { + /* Remove all template attributes from JSON list */ + for (VALUE_PAIR *vp = vps; + vp; + vp = vp->next) { + fr_pair_delete_by_da(&json_vps, vp->da); + } + + fr_pair_list_free(&vps); + } else { + /* Add template VPs to JSON list */ + fr_pair_add(&json_vps, vps); + } + + TALLOC_FREE(vpt); + + /* Jump forward to next attr */ + p += slen; + + if (*p != '\0' && !isspace((uint8_t)*p)) { + REMARKER(fmt, (p - fmt), "Missing whitespace"); + goto error; + } + } + + /* + * Given the list of attributes we now have in json_vps, + * convert them into a JSON document and append it to the + * return cursor. + */ + MEM(buf = talloc_zero_array(request, char, 8192)); + + json_str = fr_json_afrom_pair_list(request, json_vps, inst); + if (!json_str) { + REDEBUG("Failed to generate JSON string"); + goto error; + } + + slen = snprintf(out, outlen, "%s", json_str); + + fr_pair_list_free(&json_vps); + + return slen; +} + + +static int mod_bootstrap(CONF_SECTION *conf, void *instance) +{ + rlm_json_t *inst = talloc_get_type_abort(instance, rlm_json_t); + char *name; + + inst->name = cf_section_name2(conf); + if (!inst->name) inst->name = cf_section_name1(conf); + + name = talloc_asprintf(inst, "%s_encode", inst->name); + xlat_register(name, json_encode_xlat, NULL, inst); + talloc_free(name); + + /* + * Check the output format type and warn on unused + * format options + */ + inst->output_mode = fr_str2int(fr_json_format_table, inst->output_mode_str, JSON_MODE_UNSET); + if (inst->output_mode == JSON_MODE_UNSET) { + cf_log_err_cs(conf, "output_mode value \"%s\" is invalid", inst->output_mode_str); + return -1; + } + fr_json_format_verify(inst, true); + + 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_json; +module_t rlm_json = { + .magic = RLM_MODULE_INIT, + .name = "json", + .type = RLM_TYPE_THREAD_SAFE, + .inst_size = sizeof(rlm_json_t), + .config = module_config, + .bootstrap = mod_bootstrap, +}; |