src/afb-supervision.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 #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 "verbose.h"
  47 #include "wrap-json.h"
  48 #include "jobs.h"
  49
  50 extern struct afb_config *main_config;
  51
  52 /* api and apiset name */
  53 static const char supervision_apiname[] = AFS_SURPERVISION_APINAME_INTERNAL;
  54
  55 /* path of the supervision socket */
  56 static const char supervisor_socket_path[] = AFS_SURPERVISION_SOCKET;
  57
  58 /* mutual exclusion */
  59 static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
  60
  61 /* the standard apiset */
  62 extern struct afb_apiset *main_apiset;
  63
  64 /* the supervision apiset (not exported) */
  65 static struct afb_apiset *supervision_apiset;
  66
  67 /* local api implementation */
  68 static void on_supervision_call(void *closure, struct afb_xreq *xreq);
  69 static struct afb_api_itf supervision_api_itf =
  70 {
  71         .call = on_supervision_call
  72 };
  73
  74 /* the supervisor link */
  75 static struct afb_stub_ws *supervisor;
  76
  77 /* the trace api */
  78 static struct afb_trace *trace;
  79
  80 /* open the socket */
  81 static int open_supervisor_socket(const char *path)
  82 {
  83         int fd, rc;
  84         struct sockaddr_un addr;
  85         size_t length;
  86
  87         /* check path length */
  88         length = strlen(path);
  89         if (length >= 108) {
  90                 errno = ENAMETOOLONG;
  91                 return -1;
  92         }
  93
  94         /* create the unix socket */
  95         fd = socket(AF_UNIX, SOCK_STREAM, 0);
  96         if (fd < 0)
  97                 return fd;
  98
  99         /* prepare the connection address */
 100         memset(&addr, 0, sizeof addr);
 101         addr.sun_family = AF_UNIX;
 102         strcpy(addr.sun_path, path);
 103         if (addr.sun_path[0] == '@')
 104                 addr.sun_path[0] = 0; /* implement abstract sockets */
 105
 106         /* connect the socket */
 107         rc = connect(fd, (struct sockaddr *) &addr, (socklen_t)(sizeof addr));
 108         if (rc < 0) {
 109                 close(fd);
 110                 return rc;
 111         }
 112         return fd;
 113 }
 114
 115 static void disconnect_supervisor()
 116 {
 117         struct afb_stub_ws *s;
 118         struct afb_trace *t;
 119
 120         INFO("Disconnecting supervision");
 121         s = __atomic_exchange_n(&supervisor, NULL, __ATOMIC_RELAXED);
 122         t = __atomic_exchange_n(&trace, NULL, __ATOMIC_RELAXED);
 123         if (s)
 124                 afb_stub_ws_unref(s);
 125         if (t)
 126                 afb_trace_unref(t);
 127 }
 128
 129 static void on_supervisor_hangup(struct afb_stub_ws *s)
 130 {
 131         if (s && s == supervisor)
 132                 disconnect_supervisor();
 133 }
 134
 135 /* try to connect to supervisor */
 136 static void try_connect_supervisor()
 137 {
 138         int fd;
 139         ssize_t srd;
 140         struct afs_supervision_initiator initiator;
 141
 142         /* get the mutex */
 143         pthread_mutex_lock(&mutex);
 144
 145         /* needs to connect? */
 146         if (supervisor || !supervision_apiset)
 147                 goto end;
 148
 149         /* check existing path */
 150         if (supervisor_socket_path[0] != '@' && access(supervisor_socket_path, F_OK)) {
 151                 NOTICE("Can't acces socket path %s: %m", supervisor_socket_path);
 152                 goto end;
 153         }
 154
 155         /* socket connection */
 156         fd = open_supervisor_socket(supervisor_socket_path);
 157         if (fd < 0) {
 158                 NOTICE("Can't connect supervision socket to %s: %m", supervisor_socket_path);
 159                 goto end;
 160         }
 161
 162         /* negociation */
 163         do { srd = read(fd, &initiator, sizeof initiator); } while(srd < 0 && errno == EINTR);
 164         if (srd < 0) {
 165                 NOTICE("Can't read supervisor %s: %m", supervisor_socket_path);
 166                 goto end2;
 167         }
 168         if ((size_t)srd != sizeof initiator) {
 169                 ERROR("When reading supervisor %s: %m", supervisor_socket_path);
 170                 goto end2;
 171         }
 172         if (strnlen(initiator.interface, sizeof initiator.interface) == sizeof initiator.interface) {
 173                 ERROR("Bad interface of supervisor %s", supervisor_socket_path);
 174                 goto end2;
 175         }
 176         if (strcmp(initiator.interface, AFS_SURPERVISION_INTERFACE_1)) {
 177                 ERROR("Unknown interface %s for supervisor %s", initiator.interface, supervisor_socket_path);
 178                 goto end2;
 179         }
 180         if (strnlen(initiator.extra, sizeof initiator.extra) == sizeof initiator.extra) {
 181                 ERROR("Bad extra of supervisor %s", supervisor_socket_path);
 182                 goto end2;
 183         }
 184
 185         /* interprets extras */
 186         if (!strcmp(initiator.extra, "CLOSE")) {
 187                 INFO("Supervisor asks to CLOSE");
 188                 goto end2;
 189         }
 190         if (!strcmp(initiator.extra, "WAIT")) {
 191                 afb_debug_wait("supervisor");
 192         }
 193         if (!strcmp(initiator.extra, "BREAK")) {
 194                 afb_debug_break("supervisor");
 195         }
 196
 197         /* make the supervisor link */
 198         supervisor = afb_stub_ws_create_server(fd, supervision_apiname, supervision_apiset);
 199         if (!supervisor) {
 200                 ERROR("Creation of supervisor failed: %m");
 201                 goto end2;
 202         }
 203         afb_stub_ws_on_hangup(supervisor, on_supervisor_hangup);
 204
 205         /* successful termination */
 206         goto end;
 207
 208 end2:
 209         close(fd);
 210 end:
 211         pthread_mutex_unlock(&mutex);
 212 }
 213
 214 static void try_connect_supervisor_job(int signum, void *args)
 215 {
 216         INFO("Try to connect supervisor after SIGHUP");
 217         try_connect_supervisor();
 218 }
 219
 220 static void on_sighup(int signum)
 221 {
 222         INFO("Supervision received a SIGHUP");
 223         jobs_queue(NULL, 0, try_connect_supervisor_job, NULL);
 224 }
 225
 226 /**
 227  * initalize the supervision
 228  */
 229 int afb_supervision_init()
 230 {
 231         int rc;
 232         struct sigaction sa;
 233
 234         /* don't reinit */
 235         if (supervision_apiset)
 236                 return 0;
 237
 238         /* create the apiset */
 239         supervision_apiset = afb_apiset_create(supervision_apiname, 0);
 240         if (!supervision_apiset) {
 241                 ERROR("Can't create supervision's apiset");
 242                 return -1;
 243         }
 244
 245         /* init the apiset */
 246         rc = afb_apiset_add(supervision_apiset, supervision_apiname,
 247                         (struct afb_api){ .itf = &supervision_api_itf, .closure = NULL});
 248         if (rc < 0) {
 249                 ERROR("Can't create supervision's apiset: %m");
 250                 afb_apiset_unref(supervision_apiset);
 251                 supervision_apiset = NULL;
 252                 return rc;
 253         }
 254
 255         /* get SIGHUP */
 256         memset(&sa, 0, sizeof sa);
 257         sa.sa_handler = on_sighup;
 258         rc = sigaction(SIGHUP, &sa, NULL);
 259         if (rc < 0)
 260                 ERROR("Can't connect supervision to SIGHUP: %m");
 261
 262         /* connect to supervision */
 263         try_connect_supervisor();
 264         return 0;
 265 }
 266
 267 /******************************************************************************
 268 **** Implementation monitoring verbs
 269 ******************************************************************************/
 270 static void slist(void *closure, struct afb_session *session)
 271 {
 272         struct json_object *list = closure;
 273         struct json_object *item;
 274
 275         wrap_json_pack(&item, "{ss}", "token", afb_session_token(session));
 276         json_object_object_add(list, afb_session_uuid(session), item);
 277 }
 278
 279 /******************************************************************************
 280 **** Implementation monitoring verbs
 281 ******************************************************************************/
 282
 283 static const char *verbs[] = {
 284         "break", "config", "do", "exit", "sclose", "slist", "trace", "wait" };
 285 enum  {  Break ,  Config ,  Do ,  Exit ,  Sclose ,  Slist ,  Trace ,  Wait  };
 286
 287
 288 static void on_supervision_call(void *closure, struct afb_xreq *xreq)
 289 {
 290         int i, rc;
 291         struct json_object *args, *drop, *add, *sub, *list;
 292         const char *api, *verb, *uuid;
 293         struct afb_session *session;
 294         const struct afb_api *xapi;
 295         struct afb_req req;
 296
 297         /* search the verb */
 298         i = (int)(sizeof verbs / sizeof *verbs);
 299         while(--i >= 0 && strcasecmp(verbs[i], xreq->request.verb));
 300         if (i < 0) {
 301                 afb_xreq_fail_unknown_verb(xreq);
 302                 return;
 303         }
 304
 305         /* process */
 306         args = afb_xreq_json(xreq);
 307         switch(i) {
 308         case Exit:
 309                 i = 0;
 310                 if (wrap_json_unpack(args, "i", &i))
 311                         wrap_json_unpack(args, "{si}", "code", &i);
 312                 ERROR("existing from supervision with code %d -> %d", i, i & 127);
 313                 exit(i & 127);
 314                 break;
 315         case Sclose:
 316                 uuid = NULL;
 317                 if (wrap_json_unpack(args, "s", &uuid))
 318                         wrap_json_unpack(args, "{ss}", "uuid", &uuid);
 319                 if (!uuid)
 320                         afb_xreq_fail(xreq, "invalid", NULL);
 321                 else {
 322                         session = afb_session_search(uuid);
 323                         if (!session)
 324                                 afb_xreq_fail(xreq, "not-found", NULL);
 325                         else {
 326                                 afb_session_close(session);
 327                                 afb_session_unref(session);
 328                                 afb_session_purge();
 329                                 afb_xreq_success(xreq, NULL, NULL);
 330                         }
 331                 }
 332                 break;
 333         case Slist:
 334                 list = json_object_new_object();
 335                 afb_session_foreach(slist, list);
 336                 afb_xreq_success(xreq, list, NULL);
 337                 break;
 338         case Config:
 339                 afb_xreq_success(xreq, afb_config_json(main_config), NULL);
 340                 break;
 341         case Trace:
 342                 if (!trace)
 343                         trace = afb_trace_create(supervision_apiname, NULL /* not bound to any session */);
 344
 345                 req = afb_xreq_unstore((struct afb_stored_req*)xreq);
 346                 wrap_json_unpack(args, "{s?o s?o}", "add", &add, "drop", &drop);
 347                 if (add) {
 348                         rc = afb_trace_add(req, add, trace);
 349                         if (rc)
 350                                 return;
 351                 }
 352                 if (drop) {
 353                         rc = afb_trace_drop(req, drop, trace);
 354                         if (rc)
 355                                 return;
 356                 }
 357                 afb_req_success(req, NULL, NULL);
 358                 break;
 359         case Do:
 360                 sub = NULL;
 361                 if (wrap_json_unpack(args, "{ss ss s?o*}", "api", &api, "verb", &verb, "args", &sub))
 362                         afb_xreq_fail(xreq, "error", "bad request");
 363                 else {
 364                         xapi = afb_apiset_lookup_started(main_apiset, api, 1);
 365                         if (!xapi)
 366                                 afb_xreq_fail_unknown_api(xreq);
 367                         else {
 368                                 afb_cred_unref(xreq->cred);
 369                                 xreq->cred = NULL;
 370                                 xreq->request.api = api;
 371                                 xreq->request.verb = verb;
 372                                 xreq->json = json_object_get(sub);
 373                                 xapi->itf->call(xapi->closure, xreq);
 374                                 json_object_put(args);
 375                         }
 376                 }
 377                 break;
 378         case Wait:
 379                 afb_req_success(req, NULL, NULL);
 380                 afb_debug_wait("supervisor");
 381                 break;
 382         case Break:
 383                 afb_req_success(req, NULL, NULL);
 384                 afb_debug_break("supervisor");
 385                 break;
 386         }
 387 }
 388