src/afb-svc.c

   1 /*
   2  * Copyright (C) 2016, 2017 "IoT.bzh"
   3  * Author: José Bollo <jose.bollo@iot.bzh>
   4  *
   5  * Licensed under the Apache License, Version 2.0 (the "License");
   6  * you may not use this file except in compliance with the License.
   7  * You may obtain a copy of the License at
   8  *
   9  *   http://www.apache.org/licenses/LICENSE-2.0
  10  *
  11  * Unless required by applicable law or agreed to in writing, software
  12  * distributed under the License is distributed on an "AS IS" BASIS,
  13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14  * See the License for the specific language governing permissions and
  15  * limitations under the License.
  16  */
  17
  18 #define _GNU_SOURCE
  19
  20 #include <stdlib.h>
  21 #include <string.h>
  22 #include <errno.h>
  23
  24 #include <json-c/json.h>
  25
  26 #include <afb/afb-binding-v1.h>
  27 #include <afb/afb-binding-v2.h>
  28
  29 #include "afb-session.h"
  30 #include "afb-context.h"
  31 #include "afb-evt.h"
  32 #include "afb-msg-json.h"
  33 #include "afb-svc.h"
  34 #include "afb-xreq.h"
  35 #include "afb-cred.h"
  36 #include "afb-apiset.h"
  37 #include "afb-hook.h"
  38 #include "jobs.h"
  39 #include "verbose.h"
  40
  41
  42 #define HOOK(x,...) if((svc)->hookflags & afb_hook_flag_svc_##x) afb_hook_svc_##x(__VA_ARGS__)
  43
  44 /*
  45  * Structure for requests initiated by the service
  46  */
  47 struct svc_req
  48 {
  49         struct afb_xreq xreq;
  50
  51         struct afb_svc *svc;
  52
  53         /* the args */
  54         void (*callback)(void*, int, struct json_object*);
  55         void *closure;
  56
  57         /* sync */
  58         struct jobloop *jobloop;
  59         struct json_object *result;
  60         int status;
  61         int async;
  62 };
  63
  64 /* functions for services */
  65 static void svc_on_event(void *closure, const char *event, int eventid, struct json_object *object);
  66 static void svc_call(void *closure, const char *api, const char *verb, struct json_object *args,
  67                                 void (*callback)(void*, int, struct json_object*), void *cbclosure);
  68 static int svc_call_sync(void *closure, const char *api, const char *verb, struct json_object *args,
  69                                 struct json_object **result);
  70
  71 /* the interface for services */
  72 static const struct afb_service_itf service_itf = {
  73         .call = svc_call,
  74         .call_sync = svc_call_sync
  75 };
  76
  77 /* the interface for events */
  78 static const struct afb_evt_itf evt_itf = {
  79         .broadcast = svc_on_event,
  80         .push = svc_on_event
  81 };
  82
  83 /* functions for requests of services */
  84 static void svcreq_destroy(struct afb_xreq *xreq);
  85 static void svcreq_reply(struct afb_xreq *xreq, int status, json_object *obj);
  86
  87 /* interface for requests of services */
  88 const struct afb_xreq_query_itf afb_svc_xreq_itf = {
  89         .unref = svcreq_destroy,
  90         .reply = svcreq_reply
  91 };
  92
  93 /* the common session for services sharing their session */
  94 static struct afb_session *common_session;
  95
  96 static inline struct afb_service to_afb_service(struct afb_svc *svc)
  97 {
  98         return (struct afb_service){ .itf = &service_itf, .closure = svc };
  99 }
 100
 101 /*
 102  * Frees a service
 103  */
 104 static void svc_free(struct afb_svc *svc)
 105 {
 106         if (svc->listener != NULL)
 107                 afb_evt_listener_unref(svc->listener);
 108         if (svc->session)
 109                 afb_session_unref(svc->session);
 110         afb_apiset_unref(svc->apiset);
 111         free(svc);
 112 }
 113
 114 /*
 115  * Allocates a new service
 116  */
 117 static struct afb_svc *afb_svc_alloc(
 118                         const char *api,
 119                         struct afb_apiset *apiset,
 120                         int share_session
 121 )
 122 {
 123         struct afb_svc *svc;
 124
 125         /* allocates the svc handler */
 126         svc = calloc(1, sizeof * svc);
 127         if (svc == NULL) {
 128                 errno = ENOMEM;
 129                 return NULL;
 130         }
 131
 132         /* instanciate the apiset */
 133         svc->api = api;
 134         svc->apiset = afb_apiset_addref(apiset);
 135
 136         /* instanciate the session */
 137         if (share_session) {
 138                 /* session shared with other svcs */
 139                 if (common_session == NULL) {
 140                         common_session = afb_session_create (NULL, 0);
 141                         if (common_session == NULL)
 142                                 goto error;
 143                 }
 144                 svc->session = afb_session_addref(common_session);
 145         } else {
 146                 /* session dedicated to the svc */
 147                 svc->session = afb_session_create (NULL, 0);
 148                 if (svc->session == NULL)
 149                         goto error;
 150         }
 151
 152         svc->hookflags = afb_hook_flags_svc(svc->api);
 153         return svc;
 154
 155 error:
 156         svc_free(svc);
 157         return NULL;
 158 }
 159
 160 /*
 161  * Creates a new service
 162  */
 163 struct afb_svc *afb_svc_create_v1(
 164                         const char *api,
 165                         struct afb_apiset *apiset,
 166                         int share_session,
 167                         int (*start)(struct afb_service service),
 168                         void (*on_event)(const char *event, struct json_object *object)
 169 )
 170 {
 171         int rc;
 172         struct afb_svc *svc;
 173
 174         /* allocates the svc handler */
 175         svc = afb_svc_alloc(api, apiset, share_session);
 176         if (svc == NULL)
 177                 goto error;
 178
 179         /* initialises the listener if needed */
 180         if (on_event) {
 181                 svc->on_event = on_event;
 182                 svc->listener = afb_evt_listener_create(&evt_itf, svc);
 183                 if (svc->listener == NULL)
 184                         goto error;
 185         }
 186
 187         /* initialises the svc now */
 188         if (start) {
 189                 HOOK(start_before, svc);
 190                 rc = start(to_afb_service(svc));
 191                 HOOK(start_after, svc, rc);
 192                 if (rc < 0)
 193                         goto error;
 194         }
 195
 196         return svc;
 197
 198 error:
 199         svc_free(svc);
 200         return NULL;
 201 }
 202
 203 /*
 204  * Creates a new service
 205  */
 206 struct afb_svc *afb_svc_create_v2(
 207                         const char *api,
 208                         struct afb_apiset *apiset,
 209                         int share_session,
 210                         int (*start)(),
 211                         void (*on_event)(const char *event, struct json_object *object),
 212                         struct afb_binding_data_v2 *data
 213 )
 214 {
 215         int rc;
 216         struct afb_svc *svc;
 217
 218         /* allocates the svc handler */
 219         svc = afb_svc_alloc(api, apiset, share_session);
 220         if (svc == NULL)
 221                 goto error;
 222         data->service = to_afb_service(svc);
 223
 224         /* initialises the listener if needed */
 225         if (on_event) {
 226                 svc->on_event = on_event;
 227                 svc->listener = afb_evt_listener_create(&evt_itf, svc);
 228                 if (svc->listener == NULL)
 229                         goto error;
 230         }
 231
 232         /* starts the svc if needed */
 233         if (start) {
 234                 HOOK(start_before, svc);
 235                 rc = start();
 236                 HOOK(start_after, svc, rc);
 237                 if (rc < 0)
 238                         goto error;
 239         }
 240
 241         return svc;
 242
 243 error:
 244         svc_free(svc);
 245         return NULL;
 246 }
 247
 248 void afb_svc_update_hook(struct afb_svc *svc)
 249 {
 250         svc->hookflags = afb_hook_flags_svc(svc->api);
 251 }
 252
 253 /*
 254  * Propagates the event to the service
 255  */
 256 static void svc_on_event(void *closure, const char *event, int eventid, struct json_object *object)
 257 {
 258         struct afb_svc *svc = closure;
 259
 260         HOOK(on_event_before, svc, event, eventid, object);
 261         svc->on_event(event, object);
 262         HOOK(on_event_after, svc, event, eventid, object);
 263         json_object_put(object);
 264 }
 265
 266 /*
 267  * create an svc_req
 268  */
 269 static struct svc_req *svcreq_create(struct afb_svc *svc, const char *api, const char *verb, struct json_object *args)
 270 {
 271         struct svc_req *svcreq;
 272         size_t lenapi, lenverb;
 273         char *copy;
 274
 275         /* allocates the request */
 276         lenapi = 1 + strlen(api);
 277         lenverb = 1 + strlen(verb);
 278         svcreq = malloc(lenapi + lenverb + sizeof *svcreq);
 279         if (svcreq != NULL) {
 280                 /* initialises the request */
 281                 afb_xreq_init(&svcreq->xreq, &afb_svc_xreq_itf);
 282                 afb_context_init(&svcreq->xreq.context, svc->session, NULL);
 283                 svcreq->xreq.context.validated = 1;
 284                 copy = (char*)&svcreq[1];
 285                 memcpy(copy, api, lenapi);
 286                 svcreq->xreq.api = copy;
 287                 copy = &copy[lenapi];
 288                 memcpy(copy, verb, lenverb);
 289                 svcreq->xreq.verb = copy;
 290                 svcreq->xreq.listener = svc->listener;
 291                 svcreq->xreq.json = args;
 292                 svcreq->svc = svc;
 293         }
 294         return svcreq;
 295 }
 296
 297 /*
 298  * destroys the svc_req
 299  */
 300 static void svcreq_destroy(struct afb_xreq *xreq)
 301 {
 302         struct svc_req *svcreq = CONTAINER_OF_XREQ(struct svc_req, xreq);
 303
 304         afb_context_disconnect(&svcreq->xreq.context);
 305         json_object_put(svcreq->xreq.json);
 306         afb_cred_unref(svcreq->xreq.cred);
 307         free(svcreq);
 308 }
 309
 310 static void svcreq_sync_leave(struct svc_req *svcreq)
 311 {
 312         struct jobloop *jobloop = svcreq->jobloop;
 313
 314         if (jobloop) {
 315                 svcreq->jobloop = NULL;
 316                 jobs_leave(jobloop);
 317         }
 318 }
 319
 320 static void svcreq_reply(struct afb_xreq *xreq, int status, json_object *obj)
 321 {
 322         struct svc_req *svcreq = CONTAINER_OF_XREQ(struct svc_req, xreq);
 323         if (svcreq->async) {
 324                 struct afb_svc *svc = svcreq->svc;
 325                 if (svcreq->callback)
 326                         svcreq->callback(svcreq->closure, status, obj);
 327                 HOOK(call_result, svc, status, obj);
 328                 json_object_put(obj);
 329         } else {
 330                 svcreq->status = status;
 331                 svcreq->result = obj;
 332                 svcreq_sync_leave(svcreq);
 333         }
 334 }
 335
 336 static void svcreq_sync_enter(int signum, void *closure, struct jobloop *jobloop)
 337 {
 338         struct svc_req *svcreq = closure;
 339
 340         if (!signum) {
 341                 svcreq->jobloop = jobloop;
 342                 afb_xreq_process(&svcreq->xreq, svcreq->svc->apiset);
 343         } else {
 344                 svcreq->result = afb_msg_json_internal_error();
 345                 svcreq->status = -1;
 346                 svcreq_sync_leave(svcreq);
 347         }
 348 }
 349
 350 /*
 351  * Initiates a call for the service
 352  */
 353 static void svc_call(void *closure, const char *api, const char *verb, struct json_object *args, void (*callback)(void*, int, struct json_object*), void *cbclosure)
 354 {
 355         struct afb_svc *svc = closure;
 356         struct svc_req *svcreq;
 357         struct json_object *ierr;
 358
 359         HOOK(call, svc, api, verb, args);
 360
 361         /* allocates the request */
 362         svcreq = svcreq_create(svc, api, verb, args);
 363         if (svcreq == NULL) {
 364                 ERROR("out of memory");
 365                 json_object_put(args);
 366                 ierr = afb_msg_json_internal_error();
 367                 if (callback)
 368                         callback(cbclosure, -1, ierr);
 369                 HOOK(call_result, svc, -1, ierr);
 370                 json_object_put(ierr);
 371                 return;
 372         }
 373
 374         /* initialises the request */
 375         svcreq->jobloop = NULL;
 376         svcreq->callback = callback;
 377         svcreq->closure = cbclosure;
 378         svcreq->async = 1;
 379
 380         /* terminates and frees ressources if needed */
 381         afb_xreq_process(&svcreq->xreq, svc->apiset);
 382 }
 383
 384 static int svc_call_sync(void *closure, const char *api, const char *verb, struct json_object *args,
 385                                 struct json_object **result)
 386 {
 387         struct afb_svc *svc = closure;
 388         struct svc_req *svcreq;
 389         struct json_object *resu;
 390         int rc;
 391
 392         HOOK(callsync, svc, api, verb, args);
 393
 394         /* allocates the request */
 395         svcreq = svcreq_create(svc, api, verb, args);
 396         if (svcreq == NULL) {
 397                 ERROR("out of memory");
 398                 errno = ENOMEM;
 399                 json_object_put(args);
 400                 resu = afb_msg_json_internal_error();
 401                 rc = -1;
 402         } else {
 403                 /* initialises the request */
 404                 svcreq->jobloop = NULL;
 405                 svcreq->callback = NULL;
 406                 svcreq->result = NULL;
 407                 svcreq->status = 0;
 408                 svcreq->async = 0;
 409                 afb_xreq_addref(&svcreq->xreq);
 410                 rc = jobs_enter(NULL, 0, svcreq_sync_enter, svcreq);
 411                 if (rc >= 0)
 412                         rc = svcreq->status;
 413                 resu = (rc >= 0 || svcreq->result) ? svcreq->result : afb_msg_json_internal_error();
 414                 afb_xreq_unref(&svcreq->xreq);
 415         }
 416         HOOK(callsync_result, svc, rc, resu);
 417         if (result)
 418                 *result = resu;
 419         else
 420                 json_object_put(resu);
 421         return rc;
 422 }
 423