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