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 #if defined(WITH_SUPERVISION)
  19
  20 #define _GNU_SOURCE
  21
  22 #include <string.h>
  23 #include <errno.h>
  24 #include <signal.h>
  25 #include <unistd.h>
  26 #include <fcntl.h>
  27 #include <pthread.h>
  28 #include <sys/types.h>
  29 #include <sys/socket.h>
  30 #include <sys/un.h>
  31
  32 #include <json-c/json.h>
  33
  34 #define AFB_BINDING_VERSION 3
  35 #include <afb/afb-binding.h>
  36
  37 #include "afb-cred.h"
  38 #include "afb-api.h"
  39 #include "afb-apiset.h"
  40 #include "afb-api-so-v2.h"
  41 #include "afb-xreq.h"
  42 #include "afb-trace.h"
  43 #include "afb-session.h"
  44 #include "afb-config.h"
  45 #include "afb-supervision.h"
  46 #include "afs-supervision.h"
  47 #include "afb-stub-ws.h"
  48 #include "afb-debug.h"
  49 #include "afb-fdev.h"
  50 #include "verbose.h"
  51 #include "wrap-json.h"
  52 #include "jobs.h"
  53
  54 extern struct afb_config *main_config;
  55
  56 /* api and apiset name */
  57 static const char supervision_apiname[] = AFS_SUPERVISION_APINAME;
  58 static const char supervisor_apiname[] = AFS_SUPERVISOR_APINAME;
  59
  60 /* path of the supervision socket */
  61 static const char supervisor_socket_path[] = AFS_SUPERVISION_SOCKET;
  62
  63 /* mutual exclusion */
  64 static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
  65
  66 /* the standard apiset */
  67 extern struct afb_apiset *main_apiset;
  68
  69 /* the supervision apiset (not exported) */
  70 static struct afb_apiset *supervision_apiset;
  71
  72 /* local api implementation */
  73 static void on_supervision_call(void *closure, struct afb_xreq *xreq);
  74 static struct afb_api_itf supervision_api_itf =
  75 {
  76         .call = on_supervision_call
  77 };
  78
  79 /* the supervisor link */
  80 static struct afb_stub_ws *supervisor;
  81
  82 /* the trace api */
  83 static struct afb_trace *trace;
  84
  85 /* open the socket */
  86 static int open_supervisor_socket(const char *path)
  87 {
  88         int fd, rc;
  89         struct sockaddr_un addr;
  90         size_t length;
  91
  92         /* check path length */
  93         length = strlen(path);
  94         if (length >= 108) {
  95                 errno = ENAMETOOLONG;
  96                 return -1;
  97         }
  98
  99         /* create the unix socket */
 100         fd = socket(AF_UNIX, SOCK_STREAM, 0);
 101         if (fd < 0)
 102                 return fd;
 103
 104         /* prepare the connection address */
 105         memset(&addr, 0, sizeof addr);
 106         addr.sun_family = AF_UNIX;
 107         strcpy(addr.sun_path, path);
 108         if (addr.sun_path[0] == '@')
 109                 addr.sun_path[0] = 0; /* implement abstract sockets */
 110
 111         /* connect the socket */
 112         rc = connect(fd, (struct sockaddr *) &addr, (socklen_t)(sizeof addr));
 113         if (rc < 0) {
 114                 close(fd);
 115                 return rc;
 116         }
 117         return fd;
 118 }
 119
 120 static void disconnect_supervisor()
 121 {
 122         struct afb_stub_ws *s;
 123         struct afb_trace *t;
 124
 125         INFO("Disconnecting supervision");
 126         s = __atomic_exchange_n(&supervisor, NULL, __ATOMIC_RELAXED);
 127         t = __atomic_exchange_n(&trace, NULL, __ATOMIC_RELAXED);
 128         if (s)
 129                 afb_stub_ws_unref(s);
 130         if (t)
 131                 afb_trace_unref(t);
 132 }
 133
 134 static void on_supervisor_hangup(struct afb_stub_ws *s)
 135 {
 136         if (s && s == supervisor)
 137                 disconnect_supervisor();
 138 }
 139
 140 /* try to connect to supervisor */
 141 static void try_connect_supervisor()
 142 {
 143         int fd;
 144         ssize_t srd;
 145         struct afs_supervision_initiator initiator;
 146         struct fdev *fdev;
 147
 148         /* get the mutex */
 149         pthread_mutex_lock(&mutex);
 150
 151         /* needs to connect? */
 152         if (supervisor || !supervision_apiset)
 153                 goto end;
 154
 155         /* check existing path */
 156         if (supervisor_socket_path[0] != '@' && access(supervisor_socket_path, F_OK)) {
 157                 NOTICE("Can't acces socket path %s: %m", supervisor_socket_path);
 158                 goto end;
 159         }
 160
 161         /* socket connection */
 162         fd = open_supervisor_socket(supervisor_socket_path);
 163         if (fd < 0) {
 164                 NOTICE("Can't connect supervision socket to %s: %m", supervisor_socket_path);
 165                 goto end;
 166         }
 167
 168         /* negotiation */
 169         do { srd = read(fd, &initiator, sizeof initiator); } while(srd < 0 && errno == EINTR);
 170         if (srd < 0) {
 171                 NOTICE("Can't read supervisor %s: %m", supervisor_socket_path);
 172                 goto end2;
 173         }
 174         if ((size_t)srd != sizeof initiator) {
 175                 ERROR("When reading supervisor %s: %m", supervisor_socket_path);
 176                 goto end2;
 177         }
 178         if (strnlen(initiator.interface, sizeof initiator.interface) == sizeof initiator.interface) {
 179                 ERROR("Bad interface of supervisor %s", supervisor_socket_path);
 180                 goto end2;
 181         }
 182         if (strcmp(initiator.interface, AFS_SUPERVISION_INTERFACE_1)) {
 183                 ERROR("Unknown interface %s for supervisor %s", initiator.interface, supervisor_socket_path);
 184                 goto end2;
 185         }
 186         if (strnlen(initiator.extra, sizeof initiator.extra) == sizeof initiator.extra) {
 187                 ERROR("Bad extra of supervisor %s", supervisor_socket_path);
 188                 goto end2;
 189         }
 190
 191         /* interprets extras */
 192         if (!strcmp(initiator.extra, "CLOSE")) {
 193                 INFO("Supervisor asks to CLOSE");
 194                 goto end2;
 195         }
 196         if (!strcmp(initiator.extra, "WAIT")) {
 197                 afb_debug_wait("supervisor");
 198         }
 199         if (!strcmp(initiator.extra, "BREAK")) {
 200                 afb_debug_break("supervisor");
 201         }
 202
 203         /* make the supervisor link */
 204         fdev = afb_fdev_create(fd);
 205         if (!fdev) {
 206                 ERROR("Creation of fdev failed: %m");
 207                 goto end2;
 208         }
 209         supervisor = afb_stub_ws_create_server(fdev, supervision_apiname, supervision_apiset);
 210         if (!supervisor) {
 211                 ERROR("Creation of supervisor failed: %m");
 212                 goto end;
 213         }
 214         afb_stub_ws_on_hangup(supervisor, on_supervisor_hangup);
 215
 216         /* successful termination */
 217         goto end;
 218
 219 end2:
 220         close(fd);
 221 end:
 222         pthread_mutex_unlock(&mutex);
 223 }
 224
 225 static void try_connect_supervisor_job(int signum, void *args)
 226 {
 227         INFO("Try to connect supervisor after SIGHUP");
 228         try_connect_supervisor();
 229 }
 230
 231 static void on_sighup(int signum)
 232 {
 233         INFO("Supervision received a SIGHUP");
 234         jobs_queue(NULL, 0, try_connect_supervisor_job, NULL);
 235 }
 236
 237 /**
 238  * initialize the supervision
 239  */
 240 int afb_supervision_init()
 241 {
 242         int rc;
 243         struct sigaction sa;
 244
 245         /* don't reinit */
 246         if (supervision_apiset)
 247                 return 0;
 248
 249         /* create the apiset */
 250         supervision_apiset = afb_apiset_create(supervision_apiname, 0);
 251         if (!supervision_apiset) {
 252                 ERROR("Can't create supervision's apiset");
 253                 return -1;
 254         }
 255
 256         /* init the apiset */
 257         rc = afb_apiset_add(supervision_apiset, supervision_apiname,
 258                         (struct afb_api_item){ .itf = &supervision_api_itf, .closure = NULL});
 259         if (rc < 0) {
 260                 ERROR("Can't create supervision's apiset: %m");
 261                 afb_apiset_unref(supervision_apiset);
 262                 supervision_apiset = NULL;
 263                 return rc;
 264         }
 265
 266         /* get SIGHUP */
 267         memset(&sa, 0, sizeof sa);
 268         sa.sa_handler = on_sighup;
 269         rc = sigaction(SIGHUP, &sa, NULL);
 270         if (rc < 0)
 271                 ERROR("Can't connect supervision to SIGHUP: %m");
 272
 273         /* connect to supervision */
 274         try_connect_supervisor();
 275         return 0;
 276 }
 277
 278 /******************************************************************************
 279 **** Implementation monitoring verbs
 280 ******************************************************************************/
 281 static void slist(void *closure, struct afb_session *session)
 282 {
 283         struct json_object *list = closure;
 284         struct json_object *item;
 285
 286         wrap_json_pack(&item, "{ss}", "token", afb_session_token(session));
 287         json_object_object_add(list, afb_session_uuid(session), item);
 288 }
 289
 290 /******************************************************************************
 291 **** Implementation monitoring verbs
 292 ******************************************************************************/
 293
 294 static const char *verbs[] = {
 295         "break", "config", "do", "exit", "sclose", "slist", "trace", "wait" };
 296 enum  {  Break ,  Config ,  Do ,  Exit ,  Sclose ,  Slist ,  Trace ,  Wait  };
 297
 298 static void on_supervision_call(void *closure, struct afb_xreq *xreq)
 299 {
 300         int i, rc;
 301         struct json_object *args, *drop, *add, *sub, *list;
 302         const char *api, *verb, *uuid;
 303         struct afb_session *session;
 304         const struct afb_api_item *xapi;
 305         afb_req_t req;
 306
 307         /* search the verb */
 308         i = (int)(sizeof verbs / sizeof *verbs);
 309         while(--i >= 0 && strcasecmp(verbs[i], xreq->request.called_verb));
 310         if (i < 0) {
 311                 afb_xreq_reply_unknown_verb(xreq);
 312                 return;
 313         }
 314
 315         /* process */
 316         args = afb_xreq_json(xreq);
 317         switch(i) {
 318         case Exit:
 319                 i = 0;
 320                 if (wrap_json_unpack(args, "i", &i))
 321                         wrap_json_unpack(args, "{si}", "code", &i);
 322                 ERROR("exiting from supervision with code %d -> %d", i, i & 127);
 323                 exit(i & 127);
 324                 break;
 325         case Sclose:
 326                 uuid = NULL;
 327                 if (wrap_json_unpack(args, "s", &uuid))
 328                         wrap_json_unpack(args, "{ss}", "uuid", &uuid);
 329                 if (!uuid)
 330                         afb_xreq_reply(xreq, NULL, "invalid", NULL);
 331                 else {
 332                         session = afb_session_search(uuid);
 333                         if (!session)
 334                                 afb_xreq_reply(xreq, NULL, "not-found", NULL);
 335                         else {
 336                                 afb_session_close(session);
 337                                 afb_session_unref(session);
 338                                 afb_session_purge();
 339                                 afb_xreq_reply(xreq, NULL, NULL, NULL);
 340                         }
 341                 }
 342                 break;
 343         case Slist:
 344                 list = json_object_new_object();
 345                 afb_session_foreach(slist, list);
 346                 afb_xreq_reply(xreq, list, NULL, NULL);
 347                 break;
 348         case Config:
 349                 afb_xreq_reply(xreq, afb_config_json(main_config), NULL, NULL);
 350                 break;
 351         case Trace:
 352                 if (!trace)
 353                         trace = afb_trace_create(supervisor_apiname, NULL /* not bound to any session */);
 354
 355                 req = xreq_to_req_x2(xreq);
 356                 add = drop = NULL;
 357                 wrap_json_unpack(args, "{s?o s?o}", "add", &add, "drop", &drop);
 358                 if (add) {
 359                         rc = afb_trace_add(req, add, trace);
 360                         if (rc)
 361                                 return;
 362                 }
 363                 if (drop) {
 364                         rc = afb_trace_drop(req, drop, trace);
 365                         if (rc)
 366                                 return;
 367                 }
 368                 afb_req_success(req, NULL, NULL);
 369                 break;
 370         case Do:
 371                 sub = NULL;
 372                 if (wrap_json_unpack(args, "{ss ss s?o*}", "api", &api, "verb", &verb, "args", &sub))
 373                         afb_xreq_reply(xreq, NULL, "error", "bad request");
 374                 else {
 375                         xapi = afb_apiset_lookup_started(main_apiset, api, 1);
 376                         if (!xapi)
 377                                 afb_xreq_reply_unknown_api(xreq);
 378                         else {
 379                                 afb_cred_unref(xreq->cred);
 380                                 xreq->cred = NULL;
 381                                 xreq->request.called_api = api;
 382                                 xreq->request.called_verb = verb;
 383                                 xreq->json = json_object_get(sub);
 384                                 xapi->itf->call(xapi->closure, xreq);
 385                                 json_object_put(args);
 386                         }
 387                 }
 388                 break;
 389         case Wait:
 390                 afb_xreq_reply(xreq, NULL, NULL, NULL);
 391                 afb_debug_wait("supervisor");
 392                 break;
 393         case Break:
 394                 afb_xreq_reply(xreq, NULL, NULL, NULL);
 395                 afb_debug_break("supervisor");
 396                 break;
 397         }
 398 }
 399
 400 #endif