src/afb-supervision.c

   1 /*
   2  * Copyright (C) 2016, 2017, 2018 "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 #define AFB_BINDING_PRAGMA_NO_VERBOSE_MACRO
  20
  21 #include <string.h>
  22 #include <errno.h>
  23 #include <signal.h>
  24 #include <unistd.h>
  25 #include <fcntl.h>
  26 #include <pthread.h>
  27 #include <sys/types.h>
  28 #include <sys/socket.h>
  29 #include <sys/un.h>
  30
  31 #include <json-c/json.h>
  32 #include <afb/afb-binding-v2.h>
  33
  34 #include "afb-cred.h"
  35 #include "afb-api.h"
  36 #include "afb-apiset.h"
  37 #include "afb-api-so-v2.h"
  38 #include "afb-xreq.h"
  39 #include "afb-trace.h"
  40 #include "afb-session.h"
  41 #include "afb-config.h"
  42 #include "afb-supervision.h"
  43 #include "afs-supervision.h"
  44 #include "afb-stub-ws.h"
  45 #include "afb-debug.h"
  46 #include "afb-fdev.h"
  47 #include "verbose.h"
  48 #include "wrap-json.h"
  49 #include "jobs.h"
  50
  51 extern struct afb_config *main_config;
  52
  53 /* api and apiset name */
  54 static const char supervision_apiname[] = AFS_SUPERVISION_APINAME;
  55 static const char supervisor_apiname[] = AFS_SUPERVISOR_APINAME;
  56
  57 /* path of the supervision socket */
  58 static const char supervisor_socket_path[] = AFS_SUPERVISION_SOCKET;
  59
  60 /* mutual exclusion */
  61 static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
  62
  63 /* the standard apiset */
  64 extern struct afb_apiset *main_apiset;
  65
  66 /* the supervision apiset (not exported) */
  67 static struct afb_apiset *supervision_apiset;
  68
  69 /* local api implementation */
  70 static void on_supervision_call(void *closure, struct afb_xreq *xreq);
  71 static struct afb_api_itf supervision_api_itf =
  72 {
  73         .call = on_supervision_call
  74 };
  75
  76 /* the supervisor link */
  77 static struct afb_stub_ws *supervisor;
  78
  79 /* the trace api */
  80 static struct afb_trace *trace;
  81
  82 /* open the socket */
  83 static int open_supervisor_socket(const char *path)
  84 {
  85         int fd, rc;
  86         struct sockaddr_un addr;
  87         size_t length;
  88
  89         /* check path length */
  90         length = strlen(path);
  91         if (length >= 108) {
  92                 errno = ENAMETOOLONG;
  93                 return -1;
  94         }
  95
  96         /* create the unix socket */
  97         fd = socket(AF_UNIX, SOCK_STREAM, 0);
  98         if (fd < 0)
  99                 return fd;
 100
 101         /* prepare the connection address */
 102         memset(&addr, 0, sizeof addr);
 103         addr.sun_family = AF_UNIX;
 104         strcpy(addr.sun_path, path);
 105         if (addr.sun_path[0] == '@')
 106                 addr.sun_path[0] = 0; /* implement abstract sockets */
 107
 108         /* connect the socket */
 109         rc = connect(fd, (struct sockaddr *) &addr, (socklen_t)(sizeof addr));
 110         if (rc < 0) {
 111                 close(fd);
 112                 return rc;
 113         }
 114         return fd;
 115 }
 116
 117 static void disconnect_supervisor()
 118 {
 119         struct afb_stub_ws *s;
 120         struct afb_trace *t;
 121
 122         INFO("Disconnecting supervision");
 123         s = __atomic_exchange_n(&supervisor, NULL, __ATOMIC_RELAXED);
 124         t = __atomic_exchange_n(&trace, NULL, __ATOMIC_RELAXED);
 125         if (s)
 126                 afb_stub_ws_unref(s);
 127         if (t)
 128                 afb_trace_unref(t);
 129 }
 130
 131 static void on_supervisor_hangup(struct afb_stub_ws *s)
 132 {
 133         if (s && s == supervisor)
 134                 disconnect_supervisor();
 135 }
 136
 137 /* try to connect to supervisor */
 138 static void try_connect_supervisor()
 139 {
 140         int fd;
 141         ssize_t srd;
 142         struct afs_supervision_initiator initiator;
 143         struct fdev *fdev;
 144
 145         /* get the mutex */
 146         pthread_mutex_lock(&mutex);
 147
 148         /* needs to connect? */
 149         if (supervisor || !supervision_apiset)
 150                 goto end;
 151
 152         /* check existing path */
 153         if (supervisor_socket_path[0] != '@' && access(supervisor_socket_path, F_OK)) {
 154                 NOTICE("Can't acces socket path %s: %m", supervisor_socket_path);
 155                 goto end;
 156         }
 157
 158         /* socket connection */
 159         fd = open_supervisor_socket(supervisor_socket_path);
 160         if (fd < 0) {
 161                 NOTICE("Can't connect supervision socket to %s: %m", supervisor_socket_path);
 162                 goto end;
 163         }
 164
 165         /* negociation */
 166         do { srd = read(fd, &initiator, sizeof initiator); } while(srd < 0 && errno == EINTR);
 167         if (srd < 0) {
 168                 NOTICE("Can't read supervisor %s: %m", supervisor_socket_path);
 169                 goto end2;
 170         }
 171         if ((size_t)srd != sizeof initiator) {
 172                 ERROR("When reading supervisor %s: %m", supervisor_socket_path);
 173                 goto end2;
 174         }
 175         if (strnlen(initiator.interface, sizeof initiator.interface) == sizeof initiator.interface) {
 176                 ERROR("Bad interface of supervisor %s", supervisor_socket_path);
 177                 goto end2;
 178         }
 179         if (strcmp(initiator.interface, AFS_SUPERVISION_INTERFACE_1)) {
 180                 ERROR("Unknown interface %s for supervisor %s", initiator.interface, supervisor_socket_path);
 181                 goto end2;
 182         }
 183         if (strnlen(initiator.extra, sizeof initiator.extra) == sizeof initiator.extra) {
 184                 ERROR("Bad extra of supervisor %s", supervisor_socket_path);
 185                 goto end2;
 186         }
 187
 188         /* interprets extras */
 189         if (!strcmp(initiator.extra, "CLOSE")) {
 190                 INFO("Supervisor asks to CLOSE");
 191                 goto end2;
 192         }
 193         if (!strcmp(initiator.extra, "WAIT")) {
 194                 afb_debug_wait("supervisor");
 195         }
 196         if (!strcmp(initiator.extra, "BREAK")) {
 197                 afb_debug_break("supervisor");
 198         }
 199
 200         /* make the supervisor link */
 201         fdev = afb_fdev_create(fd);
 202         if (!fdev) {
 203                 ERROR("Creation of fdev failed: %m");
 204                 goto end2;
 205         }
 206         supervisor = afb_stub_ws_create_server(fdev, supervision_apiname, supervision_apiset);
 207         if (!supervisor) {
 208                 ERROR("Creation of supervisor failed: %m");
 209                 goto end;
 210         }
 211         afb_stub_ws_on_hangup(supervisor, on_supervisor_hangup);
 212
 213         /* successful termination */
 214         goto end;
 215
 216 end2:
 217         close(fd);
 218 end:
 219         pthread_mutex_unlock(&mutex);
 220 }
 221
 222 static void try_connect_supervisor_job(int signum, void *args)
 223 {
 224         INFO("Try to connect supervisor after SIGHUP");
 225         try_connect_supervisor();
 226 }
 227
 228 static void on_sighup(int signum)
 229 {
 230         INFO("Supervision received a SIGHUP");
 231         jobs_queue(NULL, 0, try_connect_supervisor_job, NULL);
 232 }
 233
 234 /**
 235  * initalize the supervision
 236  */
 237 int afb_supervision_init()
 238 {
 239         int rc;
 240         struct sigaction sa;
 241
 242         /* don't reinit */
 243         if (supervision_apiset)
 244                 return 0;
 245
 246         /* create the apiset */
 247         supervision_apiset = afb_apiset_create(supervision_apiname, 0);
 248         if (!supervision_apiset) {
 249                 ERROR("Can't create supervision's apiset");
 250                 return -1;
 251         }
 252
 253         /* init the apiset */
 254         rc = afb_apiset_add(supervision_apiset, supervision_apiname,
 255                         (struct afb_api){ .itf = &supervision_api_itf, .closure = NULL});
 256         if (rc < 0) {
 257                 ERROR("Can't create supervision's apiset: %m");
 258                 afb_apiset_unref(supervision_apiset);
 259                 supervision_apiset = NULL;
 260                 return rc;
 261         }
 262
 263         /* get SIGHUP */
 264         memset(&sa, 0, sizeof sa);
 265         sa.sa_handler = on_sighup;
 266         rc = sigaction(SIGHUP, &sa, NULL);
 267         if (rc < 0)
 268                 ERROR("Can't connect supervision to SIGHUP: %m");
 269
 270         /* connect to supervision */
 271         try_connect_supervisor();
 272         return 0;
 273 }
 274
 275 /******************************************************************************
 276 **** Implementation monitoring verbs
 277 ******************************************************************************/
 278 static void slist(void *closure, struct afb_session *session)
 279 {
 280         struct json_object *list = closure;
 281         struct json_object *item;
 282
 283         wrap_json_pack(&item, "{ss}", "token", afb_session_token(session));
 284         json_object_object_add(list, afb_session_uuid(session), item);
 285 }
 286
 287 /******************************************************************************
 288 **** Implementation monitoring verbs
 289 ******************************************************************************/
 290
 291 static const char *verbs[] = {
 292         "break", "config", "do", "exit", "sclose", "slist", "trace", "wait" };
 293 enum  {  Break ,  Config ,  Do ,  Exit ,  Sclose ,  Slist ,  Trace ,  Wait  };
 294
 295 static void on_supervision_call(void *closure, struct afb_xreq *xreq)
 296 {
 297         int i, rc;
 298         struct json_object *args, *drop, *add, *sub, *list;
 299         const char *api, *verb, *uuid;
 300         struct afb_session *session;
 301         const struct afb_api *xapi;
 302         struct afb_req req;
 303
 304         /* search the verb */
 305         i = (int)(sizeof verbs / sizeof *verbs);
 306         while(--i >= 0 && strcasecmp(verbs[i], xreq->request.verb));
 307         if (i < 0) {
 308                 afb_xreq_fail_unknown_verb(xreq);
 309                 return;
 310         }
 311
 312         /* process */
 313         args = afb_xreq_json(xreq);
 314         switch(i) {
 315         case Exit:
 316                 i = 0;
 317                 if (wrap_json_unpack(args, "i", &i))
 318                         wrap_json_unpack(args, "{si}", "code", &i);
 319                 ERROR("exiting from supervision with code %d -> %d", i, i & 127);
 320                 exit(i & 127);
 321                 break;
 322         case Sclose:
 323                 uuid = NULL;
 324                 if (wrap_json_unpack(args, "s", &uuid))
 325                         wrap_json_unpack(args, "{ss}", "uuid", &uuid);
 326                 if (!uuid)
 327                         afb_xreq_fail(xreq, "invalid", NULL);
 328                 else {
 329                         session = afb_session_search(uuid);
 330                         if (!session)
 331                                 afb_xreq_fail(xreq, "not-found", NULL);
 332                         else {
 333                                 afb_session_close(session);
 334                                 afb_session_unref(session);
 335                                 afb_session_purge();
 336                                 afb_xreq_success(xreq, NULL, NULL);
 337                         }
 338                 }
 339                 break;
 340         case Slist:
 341                 list = json_object_new_object();
 342                 afb_session_foreach(slist, list);
 343                 afb_xreq_success(xreq, list, NULL);
 344                 break;
 345         case Config:
 346                 afb_xreq_success(xreq, afb_config_json(main_config), NULL);
 347                 break;
 348         case Trace:
 349                 if (!trace)
 350                         trace = afb_trace_create(supervisor_apiname, NULL /* not bound to any session */);
 351
 352                 req = xreq_to_req(xreq);
 353                 add = drop = NULL;
 354                 wrap_json_unpack(args, "{s?o s?o}", "add", &add, "drop", &drop);
 355                 if (add) {
 356                         rc = afb_trace_add(req, add, trace);
 357                         if (rc)
 358                                 return;
 359                 }
 360                 if (drop) {
 361                         rc = afb_trace_drop(req, drop, trace);
 362                         if (rc)
 363                                 return;
 364                 }
 365                 afb_req_success(req, NULL, NULL);
 366                 break;
 367         case Do:
 368                 sub = NULL;
 369                 if (wrap_json_unpack(args, "{ss ss s?o*}", "api", &api, "verb", &verb, "args", &sub))
 370                         afb_xreq_fail(xreq, "error", "bad request");
 371                 else {
 372                         xapi = afb_apiset_lookup_started(main_apiset, api, 1);
 373                         if (!xapi)
 374                                 afb_xreq_fail_unknown_api(xreq);
 375                         else {
 376                                 afb_cred_unref(xreq->cred);
 377                                 xreq->cred = NULL;
 378                                 xreq->request.api = api;
 379                                 xreq->request.verb = verb;
 380                                 xreq->json = json_object_get(sub);
 381                                 xapi->itf->call(xapi->closure, xreq);
 382                                 json_object_put(args);
 383                         }
 384                 }
 385                 break;
 386         case Wait:
 387                 afb_req_success(req, NULL, NULL);
 388                 afb_debug_wait("supervisor");
 389                 break;
 390         case Break:
 391                 afb_req_success(req, NULL, NULL);
 392                 afb_debug_break("supervisor");
 393                 break;
 394         }
 395 }
 396