aaa_diameter: Add Diameter server support

* add the E_DM_REQUEST event, for receiving arbitrary Diameter requests
* add the dm_send_reply(<avps-json>) function, in order to reply back
    to the sender

Author: liviuchircu

aaa/aaa.h

@@ -52,7 +52,8 @@
 #define AAA_AUTH 4
 #define AAA_ACCT 5
 #define AAA_RECV 6
-#define AAA_CUSTOM 7
+#define AAA_CUSTOM_REQ 7
+#define AAA_CUSTOM_RPL 8
 
 #define AAA_GET_FROM_START 8
 #define AAA_GET_FROM_CURRENT 9

modules/aaa_diameter/aaa_diameter.c

@@ -26,6 +26,7 @@
 #include "../../ut.h"
 
 #include "aaa_impl.h"
+#include "aaa_evi.h"
 #include "peer.h"
 
 static int mod_init(void);
@@ -40,6 +41,7 @@ static int dm_send_request(struct sip_msg *msg, int *app_id, int *cmd_code,
 				str *avp_json, pv_spec_t *rpl_avps_pv);
 static int dm_send_request_async(struct sip_msg *msg, async_ctx *ctx,
 				int *app_id, int *cmd_code, str *avp_json, pv_spec_t *rpl_avps_pv);
+static int dm_send_reply(struct sip_msg *msg, str *avp_json);
 static int dm_bind_api(aaa_prot *api);
 
 int fd_log_level = FD_LOG_NOTICE;
@@ -56,6 +58,10 @@ static const cmd_export_t cmds[]= {
 		{CMD_PARAM_VAR|CMD_PARAM_OPT,0,0}, {0,0,0}},
 		ALL_ROUTES},
 
+	{"dm_send_reply", (cmd_function)dm_send_reply, {
+		{CMD_PARAM_STR,0,0}, {0,0,0}},
+		EVENT_ROUTE},
+
 	{"aaa_bind_api", (cmd_function) dm_bind_api, {{0, 0, 0}}, 0},
 	{0,0,{{0,0,0}},0}
 };
@@ -143,6 +149,11 @@ int mod_init(void)
 		return -1;
 	}
 
+	if (dm_init_evi() != 0) {
+		LM_ERR("failed to init the Diameter event\n");
+		return -1;
+	}
+
 	if (dm_init_peer() != 0) {
 		LM_ERR("failed to init the local Diameter peer\n");
 		return -1;
@@ -229,11 +240,11 @@ static int dm_send_request(struct sip_msg *msg, int *app_id, int *cmd_code,
 	struct dict_object *req;
 	cJSON *avps;
 	int rc;
-	char *rpl_avps;
+	char *rpl_avps = NULL;
 
-	if (fd_dict_search(fd_g_config->cnf_dict, DICT_COMMAND, CMD_BY_CODE_R,
-	      cmd_code, &req, ENOENT) == ENOENT) {
-		LM_ERR("unrecognized Request command code: %d\n", *cmd_code);
+	if ((rc = fd_dict_search(fd_g_config->cnf_dict, DICT_COMMAND,CMD_BY_CODE_R,
+	      cmd_code, &req, ENOENT)) != 0) {
+		LM_ERR("unrecognized Request command code: %d (errno: %d)\n", *cmd_code, rc);
 		LM_ERR("to fix this, you can define the Request/Answer format in the "
 		       "'extra-avps-file' config file\n");
 		return -1;
@@ -259,7 +270,7 @@ static int dm_send_request(struct sip_msg *msg, int *app_id, int *cmd_code,
 		goto error;
 	}
 
-	dmsg = _dm_create_message(NULL, AAA_CUSTOM, *app_id, *cmd_code);
+	dmsg = _dm_create_message(NULL, AAA_CUSTOM_REQ, *app_id, *cmd_code, NULL);
 	if (!dmsg) {
 		LM_ERR("oom\n");
 		goto error;
@@ -280,8 +291,8 @@ static int dm_send_request(struct sip_msg *msg, int *app_id, int *cmd_code,
 			LM_ERR("failed to set output rpl_avps pv to: %s\n", rpl_avps);
 	}
 
-	if (rc != 0) {
-		LM_ERR("Diameter request failed\n");
+	if (rc < 0) {
+		LM_ERR("Diameter request failed (rc: %d)\n", rc);
 		cJSON_Delete(avps);
 		return rc;
 	}
@@ -301,6 +312,108 @@ static int dm_send_request(struct sip_msg *msg, int *app_id, int *cmd_code,
 	return -1;
 }
 
+
+static int dm_send_reply(struct sip_msg *msg, str *avp_json)
+{
+	aaa_message *dmsg = NULL;
+	cJSON *avps;
+	pv_param_t evp;
+	pv_value_t res;
+	str sessid;
+	int appid, cmdcode, rc;
+	unsigned long fd_req;
+
+	if (ZSTRP(avp_json)) {
+		LM_ERR("unable to build reply (NULL 'avps_json' input)\n");
+		return -1;
+	}
+
+	avps = cJSON_Parse(avp_json->s);
+	if (!avps) {
+		LM_ERR("failed to parse input JSON ('%.*s' ..., total: %d)\n",
+		       avp_json->len > 512 ? 512 : avp_json->len, avp_json->s, avp_json->len);
+		return -1;
+	}
+
+	if (avps->type != cJSON_Array) {
+		LM_ERR("bad JSON type: must be Array ('%.*s' ..., total: %d)\n",
+		       avp_json->len > 512 ? 512 : avp_json->len, avp_json->s, avp_json->len);
+		goto error;
+	}
+
+	/* Here, we know 100% that we're inside an event_route, so we can pull the
+	 * Diameter request info (Session-ID, App, Code) using the "params" API */
+	memset(&evp, 0, sizeof evp);
+	evp.pvn.type = PV_NAME_INTSTR;
+	evp.pvn.u.isname.type = AVP_NAME_STR;
+
+	evp.pvn.u.isname.name.s = dmev_req_pname_sessid;
+	route_params_run(msg, &evp, &res);
+	if (ZSTR(res.rs) || !pvv_is_str(&res)) {
+		LM_ERR("failed to fetch unique session ID\n");
+		sessid = STR_NULL;
+	} else {
+		sessid = res.rs;
+	}
+
+	evp.pvn.u.isname.name.s = dmev_req_pname_appid;
+	route_params_run(msg, &evp, &res);
+	if (!pvv_is_int(&res)) {
+		LM_ERR("failed to fetch Application ID\n");
+		appid = 0;
+	} else {
+		appid = res.ri;
+	}
+
+	evp.pvn.u.isname.name.s = dmev_req_pname_cmdcode;
+	route_params_run(msg, &evp, &res);
+	if (!pvv_is_int(&res)) {
+		LM_ERR("failed to fetch Command Code\n");
+		cmdcode = 0;
+	} else {
+		cmdcode = res.ri;
+	}
+
+	evp.pvn.u.isname.name.s = dmev_req_pname_fdmsg;
+	route_params_run(msg, &evp, &res);
+	if (!pvv_is_str(&res)) {
+		LM_ERR("failed to fetch FD Message\n");
+		goto error;
+	} else {
+		reverse_hex2int64(res.rs.s, res.rs.len, 1, &fd_req);
+	}
+
+	dmsg = _dm_create_message(NULL, AAA_CUSTOM_RPL, appid, cmdcode, (void *)fd_req);
+	if (!dmsg) {
+		LM_ERR("oom\n");
+		goto error;
+	}
+
+	if (dm_build_avps(&((struct dm_message *)(dmsg->avpair))->avps,
+	                     avps->child) != 0) {
+		LM_ERR("failed to unpack JSON ('%.*s' ..., total: %d)\n",
+		       avp_json->len > 512 ? 512 : avp_json->len, avp_json->s, avp_json->len);
+		goto error;
+	}
+
+	rc = _dm_send_message(NULL, dmsg, NULL, NULL);
+	if (rc < 0) {
+		LM_ERR("failed to send Diameter reply (sess: %.*s, app: %d, cmd: %d)\n",
+		        sessid.len, sessid.s, appid, cmdcode);
+		cJSON_Delete(avps);
+		return rc;
+	}
+
+	cJSON_Delete(avps);
+	return 0;
+
+error:
+	_dm_destroy_message(dmsg);
+	cJSON_Delete(avps);
+	return -1;
+}
+
+
 struct dm_async_msg {
 	pv_spec_p ret;
 	struct dm_cond *cond;
@@ -403,7 +516,7 @@ static int dm_send_request_async(struct sip_msg *msg, async_ctx *ctx,
 		goto error;
 	}
 
-	dmsg = _dm_create_message(NULL, AAA_CUSTOM, *app_id, *cmd_code);
+	dmsg = _dm_create_message(NULL, AAA_CUSTOM_REQ, *app_id, *cmd_code, NULL);
 	if (!dmsg) {
 		LM_ERR("oom\n");
 		goto error;

modules/aaa_diameter/aaa_evi.c

@@ -0,0 +1,174 @@
+/*
+ * Copyright (C) 2024 OpenSIPS Solutions
+ *
+ * This file is part of opensips, a free SIP server.
+ *
+ * opensips 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
+ *
+ * opensips 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 Street, Fifth Floor, Boston, MA 02110-1301,USA
+ */
+
+#include "aaa_evi.h"
+
+#include "../../dprint.h"
+#include "../../ut.h"
+#include "../../ipc.h"
+
+ipc_handler_type dmev_req_ipc;
+
+static event_id_t dmev_req_id = EVI_ERROR; /* E_DM_REQUEST */
+static evi_params_p dmev_req_params;
+
+static evi_param_p dmev_req_param_sessid;
+static evi_param_p dmev_req_param_appid;
+static evi_param_p dmev_req_param_cmdcode;
+static evi_param_p dmev_req_param_avpsjson;
+static evi_param_p dmev_req_param_fdmsg;
+
+str dmev_req_pname_sessid = str_init("sess_id");
+str dmev_req_pname_appid = str_init("app_id");
+str dmev_req_pname_cmdcode = str_init("cmd_code");
+str dmev_req_pname_avpsjson = str_init("avps_json");
+str dmev_req_pname_fdmsg = str_init("_fdmsg_");
+
+
+static int dm_init_ipc(void)
+{
+	dmev_req_ipc = ipc_register_handler(dm_raise_event_request,
+	                                         "DM Request Dispatch");
+	if (ipc_bad_handler_type(dmev_req_ipc)) {
+		LM_ERR("failed to register 'DM Request Dispatch' IPC handler\n");
+		return -1;
+	}
+
+	return 0;
+}
+
+
+int dm_init_evi(void)
+{
+	if (dm_init_ipc() != 0) {
+		LM_ERR("failed to init IPC\n");
+		return -1;
+	}
+
+	/* First publish the events */
+	dmev_req_id = evi_publish_event(str_init("E_DM_REQUEST"));
+	if (dmev_req_id == EVI_ERROR) {
+		LM_ERR("cannot register 'request' event\n");
+		return -1;
+	}
+
+	dmev_req_params = pkg_malloc(sizeof *dmev_req_params);
+	if (!dmev_req_params) {
+		LM_ERR("oom\n");
+		return -1;
+	}
+	memset(dmev_req_params, 0, sizeof *dmev_req_params);
+
+	dmev_req_param_sessid = evi_param_create(dmev_req_params, &dmev_req_pname_sessid);
+	dmev_req_param_appid = evi_param_create(dmev_req_params, &dmev_req_pname_appid);
+	dmev_req_param_cmdcode = evi_param_create(dmev_req_params, &dmev_req_pname_cmdcode);
+	dmev_req_param_avpsjson = evi_param_create(dmev_req_params, &dmev_req_pname_avpsjson);
+	dmev_req_param_fdmsg = evi_param_create(dmev_req_params, &dmev_req_pname_fdmsg);
+	if (!dmev_req_param_sessid || !dmev_req_param_appid
+	        || !dmev_req_param_cmdcode || !dmev_req_param_avpsjson
+	        || !dmev_req_param_fdmsg) {
+		LM_ERR("failed to create EVI params\n");
+		return -1;
+	}
+
+	return 0;
+}
+
+
+int dm_dispatch_event_req(struct msg *msg, const str *sessid, int app_id,
+                          int cmd_code, const str *avps_json)
+{
+	dm_ipc_event_req *job;
+
+	job = shm_malloc(sizeof *job);
+	if (!job)
+		goto out_oom;
+	memset(job, 0, sizeof *job);
+
+	job->fd_msg = msg;
+	job->app_id = app_id;
+	job->cmd_code = cmd_code;
+
+	if (shm_nt_str_dup(&job->sessid, sessid)
+	        || shm_nt_str_dup(&job->avps_json, avps_json))
+		goto out_oom;
+
+	return ipc_dispatch_job(dmev_req_ipc, job);
+
+out_oom:
+	if (job) {
+		shm_free(job->sessid.s);
+		shm_free(job->avps_json.s);
+		shm_free(job);
+	}
+	LM_ERR("oom\n");
+	return -1;
+}
+
+
+void dm_raise_event_request(int sender, void *dm_req)
+{
+	char buf[sizeof(long)*2 + 1], *p = buf;
+	int sz = sizeof(buf);
+	str ptr;
+
+	dm_ipc_event_req *job = (dm_ipc_event_req *)dm_req;
+
+	LM_DBG("received Diameter request via IPC, tid: %.*s\n",
+	        job->sessid.len, job->sessid.s);
+
+	/* raise the event to script (dispatch) */
+	if (evi_param_set_str(dmev_req_param_sessid, &job->sessid) < 0) {
+		LM_ERR("failed to set 'sess_id'\n");
+		goto out;
+	}
+
+	if (evi_param_set_int(dmev_req_param_appid, &job->app_id) < 0) {
+		LM_ERR("failed to set 'app_id'\n");
+		goto out;
+	}
+
+	if (evi_param_set_int(dmev_req_param_cmdcode, &job->cmd_code) < 0) {
+		LM_ERR("failed to set 'cmd_code'\n");
+		goto out;
+	}
+
+	if (evi_param_set_str(dmev_req_param_avpsjson, &job->avps_json) < 0) {
+		LM_ERR("failed to set 'avps_json'\n");
+		goto out;
+	}
+
+	int64_2reverse_hex(&p, &sz, (unsigned long)job->fd_msg);
+	*p = '\0';
+	init_str(&ptr, buf);
+
+	if (evi_param_set_str(dmev_req_param_fdmsg, &ptr) < 0) {
+		LM_ERR("failed to set '_fdmsg_'\n");
+		goto out;
+	}
+
+	if (evi_raise_event(dmev_req_id, dmev_req_params) < 0)
+		LM_ERR("failed to raise 'E_DM_REQUEST' event\n");
+
+out:
+	shm_free(job->sessid.s);
+	shm_free(job->avps_json.s);
+	shm_free(job);
+}