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 /* api and apiset name */
  55 static const char supervision_apiname[] = AFS_SUPERVISION_APINAME;
  56 static const char supervisor_apiname[] = AFS_SUPERVISOR_APINAME;
  57
  58 /* path of the supervision socket */
  59 static const char supervisor_socket_path[] = AFS_SUPERVISION_SOCKET;
  60
  61 /* mutual exclusion */
  62 static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
  63
  64 /* the standard apiset */
  65 static struct {
  66         struct afb_apiset *apiset;
  67         struct json_object *config;
  68 } global;
  69
  70 /* the supervision apiset (not exported) */
  71 static struct afb_apiset *supervision_apiset;
  72
  73 /* local api implementation */
  74 static void on_supervision_call(void *closure, struct afb_xreq *xreq);
  75 static struct afb_api_itf supervision_api_itf =
  76 {
  77         .call = on_supervision_call
  78 };
  79
  80 /* the supervisor link */
  81 static struct afb_stub_ws *supervisor;
  82
  83 /* the trace api */
  84 static struct afb_trace *trace;
  85
  86 /* open the socket */
  87 static int open_supervisor_socket(const char *path)
  88 {
  89         int fd, rc;
  90         struct sockaddr_un addr;
  91         size_t length;
  92
  93         /* check path length */
  94         length = strlen(path);
  95         if (length >= 108) {
  96                 errno = ENAMETOOLONG;
  97                 return -1;
  98         }
  99
 100         /* create the unix socket */
 101         fd = socket(AF_UNIX, SOCK_STREAM, 0);
 102         if (fd < 0)
 103                 return fd;
 104
 105         /* prepare the connection address */
 106         memset(&addr, 0, sizeof addr);
 107         addr.sun_family = AF_UNIX;
 108         strcpy(addr.sun_path, path);
 109         if (addr.sun_path[0] == '@')
 110                 addr.sun_path[0] = 0; /* implement abstract sockets */
 111
 112         /* connect the socket */
 113         rc = connect(fd, (struct sockaddr *) &addr, (socklen_t)(sizeof addr));
 114         if (rc < 0) {
 115                 close(fd);
 116                 return rc;
 117         }
 118         return fd;
 119 }
 120
 121 static void disconnect_supervisor()
 122 {
 123         struct afb_stub_ws *s;
 124         struct afb_trace *t;
 125
 126         INFO("Disconnecting supervision");
 127         s = __atomic_exchange_n(&supervisor, NULL, __ATOMIC_RELAXED);
 128         t = __atomic_exchange_n(&trace, NULL, __ATOMIC_RELAXED);
 129         if (s)
 130                 afb_stub_ws_unref(s);
 131         if (t)
 132                 afb_trace_unref(t);
 133 }
 134
 135 static void on_supervisor_hangup(struct afb_stub_ws *s)
 136 {
 137         if (s && s == supervisor)
 138                 disconnect_supervisor();
 139 }
 140
 141 /* try to connect to supervisor */
 142 static void try_connect_supervisor()
 143 {
 144         int fd;
 145         ssize_t srd;
 146         struct afs_supervision_initiator initiator;
 147         struct fdev *fdev;
 148
 149         /* get the mutex */
 150         pthread_mutex_lock(&mutex);
 151
 152         /* needs to connect? */
 153         if (supervisor || !supervision_apiset)
 154                 goto end;
 155
 156         /* check existing path */
 157         if (supervisor_socket_path[0] != '@' && access(supervisor_socket_path, F_OK)) {
 158                 NOTICE("Can't acces socket path %s: %m", supervisor_socket_path);
 159                 goto end;
 160         }
 161
 162         /* socket connection */
 163         fd = open_supervisor_socket(supervisor_socket_path);
 164         if (fd < 0) {
 165                 NOTICE("Can't connect supervision socket to %s: %m", supervisor_socket_path);
 166                 goto end;
 167         }
 168
 169         /* negotiation */
 170         do { srd = read(fd, &initiator, sizeof initiator); } while(srd < 0 && errno == EINTR);
 171         if (srd < 0) {
 172                 NOTICE("Can't read supervisor %s: %m", supervisor_socket_path);
 173                 goto end2;
 174         }
 175         if ((size_t)srd != sizeof initiator) {
 176                 ERROR("When reading supervisor %s: %m", supervisor_socket_path);
 177                 goto end2;
 178         }
 179         if (strnlen(initiator.interface, sizeof initiator.interface) == sizeof initiator.interface) {
 180                 ERROR("Bad interface of supervisor %s", supervisor_socket_path);
 181                 goto end2;
 182         }
 183         if (strcmp(initiator.interface, AFS_SUPERVISION_INTERFACE_1)) {
 184                 ERROR("Unknown interface %s for supervisor %s", initiator.interface, supervisor_socket_path);
 185                 goto end2;
 186         }
 187         if (strnlen(initiator.extra, sizeof initiator.extra) == sizeof initiator.extra) {
 188                 ERROR("Bad extra of supervisor %s", supervisor_socket_path);
 189                 goto end2;
 190         }
 191
 192         /* interprets extras */
 193         if (!strcmp(initiator.extra, "CLOSE")) {
 194                 INFO("Supervisor asks to CLOSE");
 195                 goto end2;
 196         }
 197         if (!strcmp(initiator.extra, "WAIT")) {
 198                 afb_debug_wait("supervisor");
 199         }
 200         if (!strcmp(initiator.extra, "BREAK")) {
 201                 afb_debug_break("supervisor");
 202         }
 203
 204         /* make the supervisor link */
 205         fdev = afb_fdev_create(fd);
 206         if (!fdev) {
 207                 ERROR("Creation of fdev failed: %m");
 208                 goto end2;
 209         }
 210         supervisor = afb_stub_ws_create_server(fdev, supervision_apiname, supervision_apiset);
 211         if (!supervisor) {
 212                 ERROR("Creation of supervisor failed: %m");
 213                 goto end;
 214         }
 215         afb_stub_ws_set_on_hangup(supervisor, on_supervisor_hangup);
 216
 217         /* successful termination */
 218         goto end;
 219
 220 end2:
 221         close(fd);
 222 end:
 223         pthread_mutex_unlock(&mutex);
 224 }
 225
 226 static void try_connect_supervisor_job(int signum, void *args)
 227 {
 228         INFO("Try to connect supervisor after SIGHUP");
 229         try_connect_supervisor();
 230 }
 231
 232 static void on_sighup(int signum)
 233 {
 234         INFO("Supervision received a SIGHUP");
 235         jobs_queue(NULL, 0, try_connect_supervisor_job, NULL);
 236 }
 237
 238 /**
 239  * initialize the supervision
 240  */
 241 int afb_supervision_init(struct afb_apiset *apiset, struct json_object *config)
 242 {
 243         int rc;
 244         struct sigaction sa;
 245
 246         /* don't reinit */
 247         if (supervision_apiset)
 248                 return 0;
 249
 250         /* create the apiset */
 251         supervision_apiset = afb_apiset_create(supervision_apiname, 0);
 252         if (!supervision_apiset) {
 253                 ERROR("Can't create supervision's apiset");
 254                 return -1;
 255         }
 256
 257         /* init the apiset */
 258         rc = afb_apiset_add(supervision_apiset, supervision_apiname,
 259                         (struct afb_api_item){ .itf = &supervision_api_itf, .closure = NULL});
 260         if (rc < 0) {
 261                 ERROR("Can't create supervision's apiset: %m");
 262                 afb_apiset_unref(supervision_apiset);
 263                 supervision_apiset = NULL;
 264                 return rc;
 265         }
 266
 267         /* init the globals */
 268         global.apiset = apiset;
 269         global.config = config;
 270
 271         /* get SIGHUP */
 272         memset(&sa, 0, sizeof sa);
 273         sa.sa_handler = on_sighup;
 274         rc = sigaction(SIGHUP, &sa, NULL);
 275         if (rc < 0)
 276                 ERROR("Can't connect supervision to SIGHUP: %m");
 277
 278         /* connect to supervision */
 279         try_connect_supervisor();
 280         return 0;
 281 }
 282
 283 /******************************************************************************
 284 **** Implementation monitoring verbs
 285 ******************************************************************************/
 286 static void slist(void *closure, struct afb_session *session)
 287 {
 288         struct json_object *list = closure;
 289         struct json_object *item;
 290
 291         wrap_json_pack(&item, "{ss}", "token", afb_session_token(session));
 292         json_object_object_add(list, afb_session_uuid(session), item);
 293 }
 294
 295 /******************************************************************************
 296 **** Implementation monitoring verbs
 297 ******************************************************************************/
 298
 299 static const char *verbs[] = {
 300         "break", "config", "do", "exit", "sclose", "slist", "trace", "wait" };
 301 enum  {  Break ,  Config ,  Do ,  Exit ,  Sclose ,  Slist ,  Trace ,  Wait  };
 302
 303 static void on_supervision_call(void *closure, struct afb_xreq *xreq)
 304 {
 305         int i, rc;
 306         struct json_object *args, *drop, *add, *sub, *list;
 307         const char *api, *verb, *uuid;
 308         struct afb_session *session;
 309         const struct afb_api_item *xapi;
 310         afb_req_t req;
 311
 312         /* search the verb */
 313         i = (int)(sizeof verbs / sizeof *verbs);
 314         while(--i >= 0 && strcasecmp(verbs[i], xreq->request.called_verb));
 315         if (i < 0) {
 316                 afb_xreq_reply_unknown_verb(xreq);
 317                 return;
 318         }
 319
 320         /* process */
 321         args = afb_xreq_json(xreq);
 322         switch(i) {
 323         case Exit:
 324                 i = 0;
 325                 if (wrap_json_unpack(args, "i", &i))
 326                         wrap_json_unpack(args, "{si}", "code", &i);
 327                 ERROR("exiting from supervision with code %d -> %d", i, i & 127);
 328                 exit(i & 127);
 329                 break;
 330         case Sclose:
 331                 uuid = NULL;
 332                 if (wrap_json_unpack(args, "s", &uuid))
 333                         wrap_json_unpack(args, "{ss}", "uuid", &uuid);
 334                 if (!uuid)
 335                         afb_xreq_reply(xreq, NULL, "invalid", NULL);
 336                 else {
 337                         session = afb_session_search(uuid);
 338                         if (!session)
 339                                 afb_xreq_reply(xreq, NULL, "not-found", NULL);
 340                         else {
 341                                 afb_session_close(session);
 342                                 afb_session_unref(session);
 343                                 afb_session_purge();
 344                                 afb_xreq_reply(xreq, NULL, NULL, NULL);
 345                         }
 346                 }
 347                 break;
 348         case Slist:
 349                 list = json_object_new_object();
 350                 afb_session_foreach(slist, list);
 351                 afb_xreq_reply(xreq, list, NULL, NULL);
 352                 break;
 353         case Config:
 354                 afb_xreq_reply(xreq, json_object_get(global.config), NULL, NULL);
 355                 break;
 356         case Trace:
 357                 if (!trace)
 358                         trace = afb_trace_create(supervisor_apiname, NULL /* not bound to any session */);
 359
 360                 req = xreq_to_req_x2(xreq);
 361                 add = drop = NULL;
 362                 wrap_json_unpack(args, "{s?o s?o}", "add", &add, "drop", &drop);
 363                 if (add) {
 364                         rc = afb_trace_add(req, add, trace);
 365                         if (rc)
 366                                 return;
 367                 }
 368                 if (drop) {
 369                         rc = afb_trace_drop(req, drop, trace);
 370                         if (rc)
 371                                 return;
 372                 }
 373                 afb_req_success(req, NULL, NULL);
 374                 break;
 375         case Do:
 376                 sub = NULL;
 377                 if (wrap_json_unpack(args, "{ss ss s?o*}", "api", &api, "verb", &verb, "args", &sub))
 378                         afb_xreq_reply(xreq, NULL, "error", "bad request");
 379                 else {
 380                         xapi = afb_apiset_lookup_started(global.apiset, api, 1);
 381                         if (!xapi)
 382                                 afb_xreq_reply_unknown_api(xreq);
 383                         else {
 384                                 afb_cred_unref(xreq->cred);
 385                                 xreq->cred = NULL;
 386                                 xreq->request.called_api = api;
 387                                 xreq->request.called_verb = verb;
 388                                 xreq->json = json_object_get(sub);
 389                                 xapi->itf->call(xapi->closure, xreq);
 390                                 json_object_put(args);
 391                         }
 392                 }
 393                 break;
 394         case Wait:
 395                 afb_xreq_reply(xreq, NULL, NULL, NULL);
 396                 afb_debug_wait("supervisor");
 397                 break;
 398         case Break:
 399                 afb_xreq_reply(xreq, NULL, NULL, NULL);
 400                 afb_debug_break("supervisor");
 401                 break;
 402         }
 403 }
 404
 405 #endif