src/afb-hook.c

   1 /*
   2  * Copyright (C) 2016-2019 "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 WITH_AFB_HOOK  /***********************************************************/
  19
  20 #define _GNU_SOURCE
  21
  22 #include <limits.h>
  23 #include <stdio.h>
  24 #include <stdarg.h>
  25 #include <string.h>
  26 #include <pthread.h>
  27 #include <unistd.h>
  28 #include <sys/uio.h>
  29
  30 #include <json-c/json.h>
  31 #if !defined(JSON_C_TO_STRING_NOSLASHESCAPE)
  32 #define JSON_C_TO_STRING_NOSLASHESCAPE 0
  33 #endif
  34
  35 #include <afb/afb-req-x1.h>
  36 #include <afb/afb-event-x2.h>
  37
  38 #include "afb-context.h"
  39 #include "afb-hook.h"
  40 #include "afb-session.h"
  41 #include "afb-cred.h"
  42 #include "afb-xreq.h"
  43 #include "afb-export.h"
  44 #include "afb-evt.h"
  45 #include "afb-api.h"
  46 #include "afb-msg-json.h"
  47
  48 #include "globmatch.h"
  49 #include "verbose.h"
  50
  51 #define MATCH(pattern,string)   (\
  52                 pattern \
  53                         ? !fnmatch((pattern),(string),FNM_CASEFOLD|FNM_EXTMATCH|FNM_PERIOD) \
  54                         : afb_api_is_public(string))
  55
  56 #define MATCH_API(pattern,string)       MATCH(pattern,string)
  57 #define MATCH_VERB(pattern,string)      MATCH(pattern,string)
  58 #define MATCH_EVENT(pattern,string)     MATCH(pattern,string)
  59 #define MATCH_SESSION(pattern,string)   MATCH(pattern,string)
  60
  61 /**
  62  * Definition of a hook for xreq
  63  */
  64 struct afb_hook_xreq {
  65         struct afb_hook_xreq *next; /**< next hook */
  66         unsigned refcount; /**< reference count */
  67         unsigned flags; /**< hook flags */
  68         char *api; /**< api hooked or NULL for any */
  69         char *verb; /**< verb hooked or NULL for any */
  70         struct afb_session *session; /**< session hooked or NULL if any */
  71         struct afb_hook_xreq_itf *itf; /**< interface of hook */
  72         void *closure; /**< closure for callbacks */
  73 };
  74
  75 /**
  76  * Definition of a hook for export
  77  */
  78 struct afb_hook_api {
  79         struct afb_hook_api *next; /**< next hook */
  80         unsigned refcount; /**< reference count */
  81         unsigned flags; /**< hook flags */
  82         char *api; /**< api hooked or NULL for any */
  83         struct afb_hook_api_itf *itf; /**< interface of hook */
  84         void *closure; /**< closure for callbacks */
  85 };
  86
  87 /**
  88  * Definition of a hook for evt
  89  */
  90 struct afb_hook_evt {
  91         struct afb_hook_evt *next; /**< next hook */
  92         unsigned refcount; /**< reference count */
  93         unsigned flags; /**< hook flags */
  94         char *pattern; /**< event pattern name hooked or NULL for any */
  95         struct afb_hook_evt_itf *itf; /**< interface of hook */
  96         void *closure; /**< closure for callbacks */
  97 };
  98
  99 /**
 100  * Definition of a hook for session
 101  */
 102 struct afb_hook_session {
 103         struct afb_hook_session *next; /**< next hook */
 104         unsigned refcount; /**< reference count */
 105         unsigned flags; /**< hook flags */
 106         char *pattern; /**< event pattern name hooked or NULL for any */
 107         struct afb_hook_session_itf *itf; /**< interface of hook */
 108         void *closure; /**< closure for callbacks */
 109 };
 110
 111 /**
 112  * Definition of a hook for global
 113  */
 114 struct afb_hook_global {
 115         struct afb_hook_global *next; /**< next hook */
 116         unsigned refcount; /**< reference count */
 117         unsigned flags; /**< hook flags */
 118         struct afb_hook_global_itf *itf; /**< interface of hook */
 119         void *closure; /**< closure for callbacks */
 120 };
 121
 122 /* synchronization across threads */
 123 static pthread_rwlock_t rwlock = PTHREAD_RWLOCK_INITIALIZER;
 124 static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
 125
 126 /* list of hooks for xreq */
 127 static struct afb_hook_xreq *list_of_xreq_hooks = NULL;
 128
 129 /* list of hooks for export */
 130 static struct afb_hook_api *list_of_api_hooks = NULL;
 131
 132 /* list of hooks for evt */
 133 static struct afb_hook_evt *list_of_evt_hooks = NULL;
 134
 135 /* list of hooks for session */
 136 static struct afb_hook_session *list_of_session_hooks = NULL;
 137
 138 /* list of hooks for global */
 139 static struct afb_hook_global *list_of_global_hooks = NULL;
 140
 141 /* hook id */
 142 static unsigned next_hookid = 0;
 143
 144 /******************************************************************************
 145  * section: hook id
 146  *****************************************************************************/
 147 static void init_hookid(struct afb_hookid *hookid)
 148 {
 149         hookid->id = __atomic_add_fetch(&next_hookid, 1, __ATOMIC_RELAXED);
 150         clock_gettime(CLOCK_REALTIME, &hookid->time);
 151 }
 152
 153 /******************************************************************************
 154  * section: default callbacks for tracing requests
 155  *****************************************************************************/
 156
 157 static char *_pbuf_(const char *fmt, va_list args, char **palloc, char *sbuf, size_t szsbuf, size_t *outlen)
 158 {
 159         int rc;
 160         va_list cp;
 161
 162         *palloc = NULL;
 163         va_copy(cp, args);
 164         rc = vsnprintf(sbuf, szsbuf, fmt, args);
 165         if ((size_t)rc >= szsbuf) {
 166                 sbuf[szsbuf-1] = 0;
 167                 sbuf[szsbuf-2] = sbuf[szsbuf-3] = sbuf[szsbuf-4] = '.';
 168                 rc = vasprintf(palloc, fmt, cp);
 169                 if (rc >= 0)
 170                         sbuf = *palloc;
 171         }
 172         va_end(cp);
 173         if (rc >= 0 && outlen)
 174                 *outlen = (size_t)rc;
 175         return sbuf;
 176 }
 177
 178 static void _hook_(const char *fmt1, const char *fmt2, va_list arg2, ...)
 179 {
 180         static const char chars[] = "HOOK: [] \n";
 181         char *mem1, *mem2, buf1[256], buf2[2000];
 182         struct iovec iov[5];
 183         va_list arg1;
 184
 185         /* "HOOK: [" */
 186         iov[0].iov_base = (void*)&chars[0];
 187         iov[0].iov_len = 7;
 188
 189         /* fmt1 ... */
 190         va_start(arg1, arg2);
 191         iov[1].iov_base = _pbuf_(fmt1, arg1, &mem1, buf1, sizeof buf1, &iov[1].iov_len);
 192         va_end(arg1);
 193
 194         /* "] " */
 195         iov[2].iov_base = (void*)&chars[7];
 196         iov[2].iov_len = 2;
 197
 198         /* fmt2 arg2 */
 199         iov[3].iov_base = _pbuf_(fmt2, arg2, &mem2, buf2, sizeof buf2, &iov[3].iov_len);
 200
 201         /* "\n" */
 202         iov[4].iov_base = (void*)&chars[9];
 203         iov[4].iov_len = 1;
 204
 205         (void)writev(2, iov, 5);
 206
 207         free(mem1);
 208         free(mem2);
 209 }
 210
 211 static void _hook_xreq_(const struct afb_xreq *xreq, const char *format, ...)
 212 {
 213         va_list ap;
 214         va_start(ap, format);
 215         _hook_("xreq-%06d:%s/%s", format, ap, xreq->hookindex, xreq->request.called_api, xreq->request.called_verb);
 216         va_end(ap);
 217 }
 218
 219 static void hook_xreq_begin_cb(void *closure, const struct afb_hookid *hookid, const struct afb_xreq *xreq)
 220 {
 221         if (!xreq->cred)
 222                 _hook_xreq_(xreq, "BEGIN");
 223         else
 224                 _hook_xreq_(xreq, "BEGIN uid=%d=%s gid=%d pid=%d label=%s id=%s",
 225                         (int)xreq->cred->uid,
 226                         xreq->cred->user,
 227                         (int)xreq->cred->gid,
 228                         (int)xreq->cred->pid,
 229                         xreq->cred->label?:"(null)",
 230                         xreq->cred->id?:"(null)"
 231                 );
 232 }
 233
 234 static void hook_xreq_end_cb(void *closure, const struct afb_hookid *hookid, const struct afb_xreq *xreq)
 235 {
 236         _hook_xreq_(xreq, "END");
 237 }
 238
 239 static void hook_xreq_json_cb(void *closure, const struct afb_hookid *hookid, const struct afb_xreq *xreq, struct json_object *obj)
 240 {
 241         _hook_xreq_(xreq, "json() -> %s", json_object_to_json_string_ext(obj, JSON_C_TO_STRING_NOSLASHESCAPE));
 242 }
 243
 244 static void hook_xreq_get_cb(void *closure, const struct afb_hookid *hookid, const struct afb_xreq *xreq, const char *name, struct afb_arg arg)
 245 {
 246         _hook_xreq_(xreq, "get(%s) -> { name: %s, value: %s, path: %s }", name, arg.name, arg.value, arg.path);
 247 }
 248
 249 static void hook_xreq_reply_cb(void *closure, const struct afb_hookid *hookid, const struct afb_xreq *xreq, struct json_object *obj, const char *error, const char *info)
 250 {
 251         _hook_xreq_(xreq, "reply[%s](%s, %s)", error?:"success", json_object_to_json_string_ext(obj, JSON_C_TO_STRING_NOSLASHESCAPE), info);
 252 }
 253
 254 static void hook_xreq_legacy_context_get_cb(void *closure, const struct afb_hookid *hookid, const struct afb_xreq *xreq, void *value)
 255 {
 256         _hook_xreq_(xreq, "context_get() -> %p", value);
 257 }
 258
 259 static void hook_xreq_legacy_context_set_cb(void *closure, const struct afb_hookid *hookid, const struct afb_xreq *xreq, void *value, void (*free_value)(void*))
 260 {
 261         _hook_xreq_(xreq, "context_set(%p, %p)", value, free_value);
 262 }
 263
 264 static void hook_xreq_addref_cb(void *closure, const struct afb_hookid *hookid, const struct afb_xreq *xreq)
 265 {
 266         _hook_xreq_(xreq, "addref()");
 267 }
 268
 269 static void hook_xreq_unref_cb(void *closure, const struct afb_hookid *hookid, const struct afb_xreq *xreq)
 270 {
 271         _hook_xreq_(xreq, "unref()");
 272 }
 273
 274 static void hook_xreq_session_close_cb(void *closure, const struct afb_hookid *hookid, const struct afb_xreq *xreq)
 275 {
 276         _hook_xreq_(xreq, "session_close()");
 277 }
 278
 279 static void hook_xreq_session_set_LOA_cb(void *closure, const struct afb_hookid *hookid, const struct afb_xreq *xreq, unsigned level, int result)
 280 {
 281         _hook_xreq_(xreq, "session_set_LOA(%u) -> %d", level, result);
 282 }
 283
 284 static void hook_xreq_subscribe_cb(void *closure, const struct afb_hookid *hookid, const struct afb_xreq *xreq, struct afb_event_x2 *event_x2, int result)
 285 {
 286         _hook_xreq_(xreq, "subscribe(%s:%d) -> %d", afb_evt_event_x2_fullname(event_x2), afb_evt_event_x2_id(event_x2), result);
 287 }
 288
 289 static void hook_xreq_unsubscribe_cb(void *closure, const struct afb_hookid *hookid, const struct afb_xreq *xreq, struct afb_event_x2 *event_x2, int result)
 290 {
 291         _hook_xreq_(xreq, "unsubscribe(%s:%d) -> %d", afb_evt_event_x2_fullname(event_x2), afb_evt_event_x2_id(event_x2), result);
 292 }
 293
 294 static void hook_xreq_subcall_cb(void *closure, const struct afb_hookid *hookid, const struct afb_xreq *xreq, const char *api, const char *verb, struct json_object *args)
 295 {
 296         _hook_xreq_(xreq, "subcall(%s/%s, %s) ...", api, verb, json_object_to_json_string_ext(args, JSON_C_TO_STRING_NOSLASHESCAPE));
 297 }
 298
 299 static void hook_xreq_subcall_result_cb(void *closure, const struct afb_hookid *hookid, const struct afb_xreq *xreq, struct json_object *object, const char *error, const char *info)
 300 {
 301         _hook_xreq_(xreq, "    ...subcall... [%s] -> %s (%s)", error?:"success", json_object_to_json_string_ext(object, JSON_C_TO_STRING_NOSLASHESCAPE), info?:"");
 302 }
 303
 304 static void hook_xreq_subcallsync_cb(void *closure, const struct afb_hookid *hookid, const struct afb_xreq *xreq, const char *api, const char *verb, struct json_object *args)
 305 {
 306         _hook_xreq_(xreq, "subcallsync(%s/%s, %s) ...", api, verb, json_object_to_json_string_ext(args, JSON_C_TO_STRING_NOSLASHESCAPE));
 307 }
 308
 309 static void hook_xreq_subcallsync_result_cb(void *closure, const struct afb_hookid *hookid, const struct afb_xreq *xreq, int status, struct json_object *object, const char *error, const char *info)
 310 {
 311         _hook_xreq_(xreq, "    ...subcallsync... %d [%s] -> %s (%s)", status, error?:"success", json_object_to_json_string_ext(object, JSON_C_TO_STRING_NOSLASHESCAPE), info?:"");
 312 }
 313
 314 static void hook_xreq_vverbose_cb(void *closure, const struct afb_hookid *hookid, const struct afb_xreq *xreq, int level, const char *file, int line, const char *func, const char *fmt, va_list args)
 315 {
 316         int len;
 317         char *msg;
 318         va_list ap;
 319
 320         va_copy(ap, args);
 321         len = vasprintf(&msg, fmt, ap);
 322         va_end(ap);
 323
 324         if (len < 0)
 325                 _hook_xreq_(xreq, "vverbose(%d:%s, %s, %d, %s) -> %s ? ? ?", level, verbose_name_of_level(level), file, line, func, fmt);
 326         else {
 327                 _hook_xreq_(xreq, "vverbose(%d:%s, %s, %d, %s) -> %s", level, verbose_name_of_level(level), file, line, func, msg);
 328                 free(msg);
 329         }
 330 }
 331
 332 static void hook_xreq_legacy_store_cb(void *closure, const struct afb_hookid *hookid, const struct afb_xreq *xreq, struct afb_stored_req *sreq)
 333 {
 334         _hook_xreq_(xreq, "store() -> %p", sreq);
 335 }
 336
 337 static void hook_xreq_legacy_unstore_cb(void *closure, const struct afb_hookid *hookid, const struct afb_xreq *xreq)
 338 {
 339         _hook_xreq_(xreq, "unstore()");
 340 }
 341
 342 static void hook_xreq_has_permission_cb(void *closure, const struct afb_hookid *hookid, const struct afb_xreq *xreq, const char *permission, int result)
 343 {
 344         _hook_xreq_(xreq, "has_permission(%s) -> %d", permission, result);
 345 }
 346
 347 static void hook_xreq_get_application_id_cb(void *closure, const struct afb_hookid *hookid, const struct afb_xreq *xreq, char *result)
 348 {
 349         _hook_xreq_(xreq, "get_application_id() -> %s", result);
 350 }
 351
 352 static void hook_xreq_context_make_cb(void *closure, const struct afb_hookid *hookid, const struct afb_xreq *xreq, int replace, void *(*create_value)(void*), void (*free_value)(void*), void *create_closure, void *result)
 353 {
 354         _hook_xreq_(xreq, "context_make(replace=%s, %p, %p, %p) -> %p", replace?"yes":"no", create_value, free_value, create_closure, result);
 355 }
 356
 357 static void hook_xreq_get_uid_cb(void *closure, const struct afb_hookid *hookid, const struct afb_xreq *xreq, int result)
 358 {
 359         _hook_xreq_(xreq, "get_uid() -> %d", result);
 360 }
 361
 362 static void hook_xreq_get_client_info_cb(void *closure, const struct afb_hookid *hookid, const struct afb_xreq *xreq, struct json_object *result)
 363 {
 364         _hook_xreq_(xreq, "get_client_info() -> %s", json_object_to_json_string_ext(result, JSON_C_TO_STRING_NOSLASHESCAPE));
 365 }
 366
 367 static struct afb_hook_xreq_itf hook_xreq_default_itf = {
 368         .hook_xreq_begin = hook_xreq_begin_cb,
 369         .hook_xreq_end = hook_xreq_end_cb,
 370         .hook_xreq_json = hook_xreq_json_cb,
 371         .hook_xreq_get = hook_xreq_get_cb,
 372         .hook_xreq_reply = hook_xreq_reply_cb,
 373         .hook_xreq_legacy_context_get = hook_xreq_legacy_context_get_cb,
 374         .hook_xreq_legacy_context_set = hook_xreq_legacy_context_set_cb,
 375         .hook_xreq_addref = hook_xreq_addref_cb,
 376         .hook_xreq_unref = hook_xreq_unref_cb,
 377         .hook_xreq_session_close = hook_xreq_session_close_cb,
 378         .hook_xreq_session_set_LOA = hook_xreq_session_set_LOA_cb,
 379         .hook_xreq_subscribe = hook_xreq_subscribe_cb,
 380         .hook_xreq_unsubscribe = hook_xreq_unsubscribe_cb,
 381         .hook_xreq_subcall = hook_xreq_subcall_cb,
 382         .hook_xreq_subcall_result = hook_xreq_subcall_result_cb,
 383         .hook_xreq_subcallsync = hook_xreq_subcallsync_cb,
 384         .hook_xreq_subcallsync_result = hook_xreq_subcallsync_result_cb,
 385         .hook_xreq_vverbose = hook_xreq_vverbose_cb,
 386         .hook_xreq_legacy_store = hook_xreq_legacy_store_cb,
 387         .hook_xreq_legacy_unstore = hook_xreq_legacy_unstore_cb,
 388         .hook_xreq_has_permission = hook_xreq_has_permission_cb,
 389         .hook_xreq_get_application_id = hook_xreq_get_application_id_cb,
 390         .hook_xreq_context_make = hook_xreq_context_make_cb,
 391         .hook_xreq_get_uid = hook_xreq_get_uid_cb,
 392         .hook_xreq_get_client_info = hook_xreq_get_client_info_cb,
 393 };
 394
 395 /******************************************************************************
 396  * section: hooks for tracing requests
 397  *****************************************************************************/
 398
 399 #define _HOOK_XREQ_2_(flag,func,...)   \
 400         struct afb_hook_xreq *hook; \
 401         struct afb_hookid hookid; \
 402         pthread_rwlock_rdlock(&rwlock); \
 403         init_hookid(&hookid); \
 404         hook = list_of_xreq_hooks; \
 405         while (hook) { \
 406                 if (hook->refcount \
 407                  && hook->itf->hook_xreq_##func \
 408                  && (hook->flags & afb_hook_flag_req_##flag) != 0 \
 409                  && (!hook->session || hook->session == xreq->context.session) \
 410                  && MATCH_API(hook->api, xreq->request.called_api) \
 411                  && MATCH_VERB(hook->verb, xreq->request.called_verb)) { \
 412                         hook->itf->hook_xreq_##func(hook->closure, &hookid, __VA_ARGS__); \
 413                 } \
 414                 hook = hook->next; \
 415         } \
 416         pthread_rwlock_unlock(&rwlock);
 417
 418 #define _HOOK_XREQ_(what,...)   _HOOK_XREQ_2_(what,what,__VA_ARGS__)
 419
 420 void afb_hook_xreq_begin(const struct afb_xreq *xreq)
 421 {
 422         _HOOK_XREQ_(begin, xreq);
 423 }
 424
 425 void afb_hook_xreq_end(const struct afb_xreq *xreq)
 426 {
 427         _HOOK_XREQ_(end, xreq);
 428 }
 429
 430 struct json_object *afb_hook_xreq_json(const struct afb_xreq *xreq, struct json_object *obj)
 431 {
 432         _HOOK_XREQ_(json, xreq, obj);
 433         return obj;
 434 }
 435
 436 struct afb_arg afb_hook_xreq_get(const struct afb_xreq *xreq, const char *name, struct afb_arg arg)
 437 {
 438         _HOOK_XREQ_(get, xreq, name, arg);
 439         return arg;
 440 }
 441
 442 void afb_hook_xreq_reply(const struct afb_xreq *xreq, struct json_object *obj, const char *error, const char *info)
 443 {
 444         _HOOK_XREQ_(reply, xreq, obj, error, info);
 445 }
 446
 447 void *afb_hook_xreq_legacy_context_get(const struct afb_xreq *xreq, void *value)
 448 {
 449         _HOOK_XREQ_(legacy_context_get, xreq, value);
 450         return value;
 451 }
 452
 453 void afb_hook_xreq_legacy_context_set(const struct afb_xreq *xreq, void *value, void (*free_value)(void*))
 454 {
 455         _HOOK_XREQ_(legacy_context_set, xreq, value, free_value);
 456 }
 457
 458 void afb_hook_xreq_addref(const struct afb_xreq *xreq)
 459 {
 460         _HOOK_XREQ_(addref, xreq);
 461 }
 462
 463 void afb_hook_xreq_unref(const struct afb_xreq *xreq)
 464 {
 465         _HOOK_XREQ_(unref, xreq);
 466 }
 467
 468 void afb_hook_xreq_session_close(const struct afb_xreq *xreq)
 469 {
 470         _HOOK_XREQ_(session_close, xreq);
 471 }
 472
 473 int afb_hook_xreq_session_set_LOA(const struct afb_xreq *xreq, unsigned level, int result)
 474 {
 475         _HOOK_XREQ_(session_set_LOA, xreq, level, result);
 476         return result;
 477 }
 478
 479 int afb_hook_xreq_subscribe(const struct afb_xreq *xreq, struct afb_event_x2 *event_x2, int result)
 480 {
 481         _HOOK_XREQ_(subscribe, xreq, event_x2, result);
 482         return result;
 483 }
 484
 485 int afb_hook_xreq_unsubscribe(const struct afb_xreq *xreq, struct afb_event_x2 *event_x2, int result)
 486 {
 487         _HOOK_XREQ_(unsubscribe, xreq, event_x2, result);
 488         return result;
 489 }
 490
 491 void afb_hook_xreq_subcall(const struct afb_xreq *xreq, const char *api, const char *verb, struct json_object *args, int flags)
 492 {
 493         _HOOK_XREQ_(subcall, xreq, api, verb, args);
 494 }
 495
 496 void afb_hook_xreq_subcall_result(const struct afb_xreq *xreq, struct json_object *object, const char *error, const char *info)
 497 {
 498         _HOOK_XREQ_(subcall_result, xreq, object, error, info);
 499 }
 500
 501 void afb_hook_xreq_subcallsync(const struct afb_xreq *xreq, const char *api, const char *verb, struct json_object *args, int flags)
 502 {
 503         _HOOK_XREQ_(subcallsync, xreq, api, verb, args);
 504 }
 505
 506 int  afb_hook_xreq_subcallsync_result(const struct afb_xreq *xreq, int status, struct json_object *object, const char *error, const char *info)
 507 {
 508         _HOOK_XREQ_(subcallsync_result, xreq, status, object, error, info);
 509         return status;
 510 }
 511
 512 void afb_hook_xreq_vverbose(const struct afb_xreq *xreq, int level, const char *file, int line, const char *func, const char *fmt, va_list args)
 513 {
 514         _HOOK_XREQ_(vverbose, xreq, level, file ?: "?", line, func ?: "?", fmt, args);
 515 }
 516
 517 void afb_hook_xreq_legacy_store(const struct afb_xreq *xreq, struct afb_stored_req *sreq)
 518 {
 519         _HOOK_XREQ_(legacy_store, xreq, sreq);
 520 }
 521
 522 void afb_hook_xreq_legacy_unstore(const struct afb_xreq *xreq)
 523 {
 524         _HOOK_XREQ_(legacy_unstore, xreq);
 525 }
 526
 527 int afb_hook_xreq_has_permission(const struct afb_xreq *xreq, const char *permission, int result)
 528 {
 529         _HOOK_XREQ_(has_permission, xreq, permission, result);
 530         return result;
 531 }
 532
 533 char *afb_hook_xreq_get_application_id(const struct afb_xreq *xreq, char *result)
 534 {
 535         _HOOK_XREQ_(get_application_id, xreq, result);
 536         return result;
 537 }
 538
 539 void *afb_hook_xreq_context_make(const struct afb_xreq *xreq, int replace, void *(*create_value)(void*), void (*free_value)(void*), void *create_closure, void *result)
 540 {
 541         _HOOK_XREQ_(context_make, xreq, replace, create_value, free_value, create_closure, result);
 542         return result;
 543 }
 544
 545 int afb_hook_xreq_get_uid(const struct afb_xreq *xreq, int result)
 546 {
 547         _HOOK_XREQ_(get_uid, xreq, result);
 548         return result;
 549 }
 550
 551 struct json_object *afb_hook_xreq_get_client_info(const struct afb_xreq *xreq, struct json_object *result)
 552 {
 553         _HOOK_XREQ_(get_client_info, xreq, result);
 554         return result;
 555 }
 556
 557 /******************************************************************************
 558  * section: hooking xreqs
 559  *****************************************************************************/
 560
 561 void afb_hook_init_xreq(struct afb_xreq *xreq)
 562 {
 563         static int reqindex = 0;
 564
 565         int f, flags;
 566         int add, x;
 567         struct afb_hook_xreq *hook;
 568
 569         /* scan hook list to get the expected flags */
 570         flags = 0;
 571         pthread_rwlock_rdlock(&rwlock);
 572         hook = list_of_xreq_hooks;
 573         while (hook) {
 574                 f = hook->flags & afb_hook_flags_req_all;
 575                 add = f != 0
 576                    && (!hook->session || hook->session == xreq->context.session)
 577                    && MATCH_API(hook->api, xreq->request.called_api)
 578                    && MATCH_VERB(hook->verb, xreq->request.called_verb);
 579                 if (add)
 580                         flags |= f;
 581                 hook = hook->next;
 582         }
 583         pthread_rwlock_unlock(&rwlock);
 584
 585         /* store the hooking data */
 586         xreq->hookflags = flags;
 587         if (flags) {
 588                 do {
 589                         x = __atomic_load_n(&reqindex, __ATOMIC_RELAXED);
 590                         xreq->hookindex = (x + 1) % 1000000 ?: 1;
 591                 } while (x != __atomic_exchange_n(&reqindex, xreq->hookindex, __ATOMIC_RELAXED));
 592         }
 593 }
 594
 595 struct afb_hook_xreq *afb_hook_create_xreq(const char *api, const char *verb, struct afb_session *session, int flags, struct afb_hook_xreq_itf *itf, void *closure)
 596 {
 597         struct afb_hook_xreq *hook;
 598
 599         /* alloc the result */
 600         hook = calloc(1, sizeof *hook);
 601         if (hook == NULL)
 602                 return NULL;
 603
 604         /* get a copy of the names */
 605         hook->api = api ? strdup(api) : NULL;
 606         hook->verb = verb ? strdup(verb) : NULL;
 607         if ((api && !hook->api) || (verb && !hook->verb)) {
 608                 free(hook->api);
 609                 free(hook->verb);
 610                 free(hook);
 611                 return NULL;
 612         }
 613
 614         /* initialise the rest */
 615         hook->session = session;
 616         if (session)
 617                 afb_session_addref(session);
 618         hook->refcount = 1;
 619         hook->flags = flags;
 620         hook->itf = itf ? itf : &hook_xreq_default_itf;
 621         hook->closure = closure;
 622
 623         /* record the hook */
 624         pthread_mutex_lock(&mutex);
 625         hook->next = list_of_xreq_hooks;
 626         list_of_xreq_hooks = hook;
 627         pthread_mutex_unlock(&mutex);
 628
 629         /* returns it */
 630         return hook;
 631 }
 632
 633 struct afb_hook_xreq *afb_hook_addref_xreq(struct afb_hook_xreq *hook)
 634 {
 635         __atomic_add_fetch(&hook->refcount, 1, __ATOMIC_RELAXED);
 636         return hook;
 637 }
 638
 639 static void hook_clean_xreq()
 640 {
 641         struct afb_hook_xreq **prv, *hook, *head;
 642
 643         if (pthread_rwlock_trywrlock(&rwlock) == 0) {
 644                 /* unlink under mutex */
 645                 head = NULL;
 646                 pthread_mutex_lock(&mutex);
 647                 prv = &list_of_xreq_hooks;
 648                 while ((hook = *prv)) {
 649                         if (hook->refcount)
 650                                 prv = &(*prv)->next;
 651                         else {
 652                                 *prv = hook->next;
 653                                 hook->next = head;
 654                                 head = hook;
 655                         }
 656                 }
 657                 pthread_mutex_unlock(&mutex);
 658                 pthread_rwlock_unlock(&rwlock);
 659
 660                 /* free found hooks */
 661                 while((hook = head)) {
 662                         head = hook->next;
 663                         free(hook->api);
 664                         free(hook->verb);
 665                         if (hook->session)
 666                                 afb_session_unref(hook->session);
 667                         free(hook);
 668                 }
 669         }
 670 }
 671
 672 void afb_hook_unref_xreq(struct afb_hook_xreq *hook)
 673 {
 674         if (hook && !__atomic_sub_fetch(&hook->refcount, 1, __ATOMIC_RELAXED))
 675                 hook_clean_xreq();
 676 }
 677
 678 /******************************************************************************
 679  * section: default callbacks for tracing daemon interface
 680  *****************************************************************************/
 681
 682 static void _hook_api_(const struct afb_export *export, const char *format, ...)
 683 {
 684         va_list ap;
 685         va_start(ap, format);
 686         _hook_("api-%s", format, ap, afb_export_apiname(export));
 687         va_end(ap);
 688 }
 689
 690 static void hook_api_event_broadcast_before_cb(void *closure, const struct afb_hookid *hookid, const struct afb_export *export, const char *name, struct json_object *object)
 691 {
 692         _hook_api_(export, "event_broadcast.before(%s, %s)....", name, json_object_to_json_string_ext(object, JSON_C_TO_STRING_NOSLASHESCAPE));
 693 }
 694
 695 static void hook_api_event_broadcast_after_cb(void *closure, const struct afb_hookid *hookid, const struct afb_export *export, const char *name, struct json_object *object, int result)
 696 {
 697         _hook_api_(export, "event_broadcast.after(%s, %s) -> %d", name, json_object_to_json_string_ext(object, JSON_C_TO_STRING_NOSLASHESCAPE), result);
 698 }
 699
 700 static void hook_api_get_event_loop_cb(void *closure, const struct afb_hookid *hookid, const struct afb_export *export, struct sd_event *result)
 701 {
 702         _hook_api_(export, "get_event_loop() -> %p", result);
 703 }
 704
 705 static void hook_api_get_user_bus_cb(void *closure, const struct afb_hookid *hookid, const struct afb_export *export, struct sd_bus *result)
 706 {
 707         _hook_api_(export, "get_user_bus() -> %p", result);
 708 }
 709
 710 static void hook_api_get_system_bus_cb(void *closure, const struct afb_hookid *hookid, const struct afb_export *export, struct sd_bus *result)
 711 {
 712         _hook_api_(export, "get_system_bus() -> %p", result);
 713 }
 714
 715 static void hook_api_vverbose_cb(void *closure, const struct afb_hookid *hookid, const struct afb_export *export, int level, const char *file, int line, const char *function, const char *fmt, va_list args)
 716 {
 717         int len;
 718         char *msg;
 719         va_list ap;
 720
 721         va_copy(ap, args);
 722         len = vasprintf(&msg, fmt, ap);
 723         va_end(ap);
 724
 725         if (len < 0)
 726                 _hook_api_(export, "vverbose(%d:%s, %s, %d, %s) -> %s ? ? ?", level, verbose_name_of_level(level), file, line, function, fmt);
 727         else {
 728                 _hook_api_(export, "vverbose(%d:%s, %s, %d, %s) -> %s", level, verbose_name_of_level(level), file, line, function, msg);
 729                 free(msg);
 730         }
 731 }
 732
 733 static void hook_api_event_make_cb(void *closure, const struct afb_hookid *hookid, const struct afb_export *export, const char *name, struct afb_event_x2 *result)
 734 {
 735         _hook_api_(export, "event_make(%s) -> %s:%d", name, afb_evt_event_x2_fullname(result), afb_evt_event_x2_id(result));
 736 }
 737
 738 static void hook_api_rootdir_get_fd_cb(void *closure, const struct afb_hookid *hookid, const struct afb_export *export, int result)
 739 {
 740         char path[PATH_MAX], proc[100];
 741         ssize_t s;
 742
 743         if (result < 0)
 744                 _hook_api_(export, "rootdir_get_fd() -> %d, %m", result);
 745         else {
 746                 snprintf(proc, sizeof proc, "/proc/self/fd/%d", result);
 747                 s = readlink(proc, path, sizeof path);
 748                 path[s < 0 ? 0 : s >= sizeof path ? sizeof path - 1 : s] = 0;
 749                 _hook_api_(export, "rootdir_get_fd() -> %d = %s", result, path);
 750         }
 751 }
 752
 753 static void hook_api_rootdir_open_locale_cb(void *closure, const struct afb_hookid *hookid, const struct afb_export *export, const char *filename, int flags, const char *locale, int result)
 754 {
 755         char path[PATH_MAX], proc[100];
 756         ssize_t s;
 757
 758         if (!locale)
 759                 locale = "(null)";
 760         if (result < 0)
 761                 _hook_api_(export, "rootdir_open_locale(%s, %d, %s) -> %d, %m", filename, flags, locale, result);
 762         else {
 763                 snprintf(proc, sizeof proc, "/proc/self/fd/%d", result);
 764                 s = readlink(proc, path, sizeof path);
 765                 path[s < 0 ? 0 : s >= sizeof path ? sizeof path - 1 : s] = 0;
 766                 _hook_api_(export, "rootdir_open_locale(%s, %d, %s) -> %d = %s", filename, flags, locale, result, path);
 767         }
 768 }
 769
 770 static void hook_api_queue_job_cb(void *closure, const struct afb_hookid *hookid, const struct afb_export *export, void (*callback)(int signum, void *arg), void *argument, void *group, int timeout, int result)
 771 {
 772         _hook_api_(export, "queue_job(%p, %p, %p, %d) -> %d", callback, argument, group, timeout, result);
 773 }
 774
 775 static void hook_api_unstore_req_cb(void *closure, const struct afb_hookid *hookid,  const struct afb_export *export, struct afb_stored_req *sreq)
 776 {
 777         _hook_api_(export, "unstore_req(%p)", sreq);
 778 }
 779
 780 static void hook_api_require_api_cb(void *closure, const struct afb_hookid *hookid, const struct afb_export *export, const char *name, int initialized)
 781 {
 782         _hook_api_(export, "require_api(%s, %d)...", name, initialized);
 783 }
 784
 785 static void hook_api_require_api_result_cb(void *closure, const struct afb_hookid *hookid, const struct afb_export *export, const char *name, int initialized, int result)
 786 {
 787         _hook_api_(export, "...require_api(%s, %d) -> %d", name, initialized, result);
 788 }
 789
 790 static void hook_api_add_alias_cb(void *closure, const struct afb_hookid *hookid, const struct afb_export *export, const char *api, const char *alias, int result)
 791 {
 792         _hook_api_(export, "add_alias(%s -> %s) -> %d", api, alias?:"<null>", result);
 793 }
 794
 795 static void hook_api_start_before_cb(void *closure, const struct afb_hookid *hookid, const struct afb_export *export)
 796 {
 797         _hook_api_(export, "start.before");
 798 }
 799
 800 static void hook_api_start_after_cb(void *closure, const struct afb_hookid *hookid, const struct afb_export *export, int status)
 801 {
 802         _hook_api_(export, "start.after -> %d", status);
 803 }
 804
 805 static void hook_api_on_event_before_cb(void *closure, const struct afb_hookid *hookid, const struct afb_export *export, const char *event, int event_x2, struct json_object *object)
 806 {
 807         _hook_api_(export, "on_event.before(%s, %d, %s)", event, event_x2, json_object_to_json_string_ext(object, JSON_C_TO_STRING_NOSLASHESCAPE));
 808 }
 809
 810 static void hook_api_on_event_after_cb(void *closure, const struct afb_hookid *hookid, const struct afb_export *export, const char *event, int event_x2, struct json_object *object)
 811 {
 812         _hook_api_(export, "on_event.after(%s, %d, %s)", event, event_x2, json_object_to_json_string_ext(object, JSON_C_TO_STRING_NOSLASHESCAPE));
 813 }
 814
 815 static void hook_api_call_cb(void *closure, const struct afb_hookid *hookid, const struct afb_export *export, const char *api, const char *verb, struct json_object *args)
 816 {
 817         _hook_api_(export, "call(%s/%s, %s) ...", api, verb, json_object_to_json_string_ext(args, JSON_C_TO_STRING_NOSLASHESCAPE));
 818 }
 819
 820 static void hook_api_call_result_cb(void *closure, const struct afb_hookid *hookid, const struct afb_export *export, struct json_object *object, const char *error, const char *info)
 821 {
 822         _hook_api_(export, "    ...call... [%s] -> %s (%s)", error?:"success", json_object_to_json_string_ext(object, JSON_C_TO_STRING_NOSLASHESCAPE), info?:"");
 823 }
 824
 825 static void hook_api_callsync_cb(void *closure, const struct afb_hookid *hookid, const struct afb_export *export, const char *api, const char *verb, struct json_object *args)
 826 {
 827         _hook_api_(export, "callsync(%s/%s, %s) ...", api, verb, json_object_to_json_string_ext(args, JSON_C_TO_STRING_NOSLASHESCAPE));
 828 }
 829
 830 static void hook_api_callsync_result_cb(void *closure, const struct afb_hookid *hookid, const struct afb_export *export, int status, struct json_object *object, const char *error, const char *info)
 831 {
 832         _hook_api_(export, "    ...callsync... %d [%s] -> %s (%s)", status, error?:"success", json_object_to_json_string_ext(object, JSON_C_TO_STRING_NOSLASHESCAPE), info?:"");
 833 }
 834
 835 static void hook_api_new_api_before_cb(void *closure, const struct afb_hookid *hookid, const struct afb_export *export, const char *api, const char *info, int noconcurrency)
 836 {
 837         _hook_api_(export, "new_api.before %s (%s)%s ...", api, info?:"", noconcurrency?" no-concurrency" : "");
 838 }
 839
 840 static void hook_api_new_api_after_cb(void *closure, const struct afb_hookid *hookid, const struct afb_export *export, int result, const char *api)
 841 {
 842         _hook_api_(export, "... new_api.after %s -> %s (%d)", api, result >= 0 ? "OK" : "ERROR", result);
 843 }
 844
 845 static void hook_api_api_set_verbs_v2_cb(void *closure, const struct afb_hookid *hookid, const struct afb_export *export, int result, const struct afb_verb_v2 *verbs)
 846 {
 847         _hook_api_(export, "set_verbs_v2 -> %s (%d)", result >= 0 ? "OK" : "ERROR", result);
 848 }
 849
 850 static void hook_api_api_set_verbs_v3_cb(void *closure, const struct afb_hookid *hookid, const struct afb_export *export, int result, const struct afb_verb_v3 *verbs)
 851 {
 852         _hook_api_(export, "set_verbs_v3 -> %s (%d)", result >= 0 ? "OK" : "ERROR", result);
 853 }
 854
 855 static void hook_api_api_add_verb_cb(void *closure, const struct afb_hookid *hookid, const struct afb_export *export, int result, const char *verb, const char *info, int glob)
 856 {
 857         _hook_api_(export, "add_verb(%s%s [%s]) -> %s (%d)", verb, glob?" (GLOB)":"", info?:"", result >= 0 ? "OK" : "ERROR", result);
 858 }
 859
 860 static void hook_api_api_del_verb_cb(void *closure, const struct afb_hookid *hookid, const struct afb_export *export, int result, const char *verb)
 861 {
 862         _hook_api_(export, "del_verb(%s) -> %s (%d)", verb, result >= 0 ? "OK" : "ERROR", result);
 863 }
 864
 865 static void hook_api_api_set_on_event_cb(void *closure, const struct afb_hookid *hookid, const struct afb_export *export, int result)
 866 {
 867         _hook_api_(export, "set_on_event -> %s (%d)", result >= 0 ? "OK" : "ERROR", result);
 868 }
 869
 870 static void hook_api_api_set_on_init_cb(void *closure, const struct afb_hookid *hookid, const struct afb_export *export, int result)
 871 {
 872         _hook_api_(export, "set_on_init -> %s (%d)", result >= 0 ? "OK" : "ERROR", result);
 873 }
 874
 875 static void hook_api_api_seal_cb(void *closure, const struct afb_hookid *hookid, const struct afb_export *export)
 876 {
 877         _hook_api_(export, "seal");
 878 }
 879
 880 static void hook_api_event_handler_add_cb(void *closure, const struct afb_hookid *hookid, const struct afb_export *export, int result, const char *pattern)
 881 {
 882         _hook_api_(export, "event_handler_add(%s) -> %s (%d)", pattern, result >= 0 ? "OK" : "ERROR", result);
 883 }
 884
 885 static void hook_api_event_handler_del_cb(void *closure, const struct afb_hookid *hookid, const struct afb_export *export, int result, const char *pattern)
 886 {
 887         _hook_api_(export, "event_handler_del(%s) -> %s (%d)", pattern, result >= 0 ? "OK" : "ERROR", result);
 888 }
 889
 890 static void hook_api_class_provide_cb(void *closure, const struct afb_hookid *hookid, const struct afb_export *export, int result, const char *name)
 891 {
 892         _hook_api_(export, "class_provide(%s) -> %s (%d)", name, result >= 0 ? "OK" : "ERROR", result);
 893 }
 894
 895 static void hook_api_class_require_cb(void *closure, const struct afb_hookid *hookid, const struct afb_export *export, int result, const char *name)
 896 {
 897         _hook_api_(export, "class_require(%s) -> %s (%d)", name, result >= 0 ? "OK" : "ERROR", result);
 898 }
 899
 900 static void hook_api_delete_api_cb(void *closure, const struct afb_hookid *hookid, const struct afb_export *export, int result)
 901 {
 902         _hook_api_(export, "delete_api -> %s (%d)", result >= 0 ? "OK" : "ERROR", result);
 903 }
 904
 905 static void hook_api_on_event_handler_before_cb(void *closure, const struct afb_hookid *hookid, const struct afb_export *export, const char *event, int event_x2, struct json_object *object, const char *pattern)
 906 {
 907         _hook_api_(export, "on_event_handler[%s].before(%s, %d, %s)", pattern, event, event_x2, json_object_to_json_string_ext(object, JSON_C_TO_STRING_NOSLASHESCAPE));
 908 }
 909
 910 static void hook_api_on_event_handler_after_cb(void *closure, const struct afb_hookid *hookid, const struct afb_export *export, const char *event, int event_x2, struct json_object *object, const char *pattern)
 911 {
 912         _hook_api_(export, "on_event_handler[%s].after(%s, %d, %s)", pattern, event, event_x2, json_object_to_json_string_ext(object, JSON_C_TO_STRING_NOSLASHESCAPE));
 913 }
 914
 915 static void hook_api_settings_cb(void *closure, const struct afb_hookid *hookid, const struct afb_export *export, struct json_object *object)
 916 {
 917         _hook_api_(export, "settings -> %s", json_object_to_json_string_ext(object, JSON_C_TO_STRING_NOSLASHESCAPE));
 918 }
 919
 920 static struct afb_hook_api_itf hook_api_default_itf = {
 921         .hook_api_event_broadcast_before = hook_api_event_broadcast_before_cb,
 922         .hook_api_event_broadcast_after = hook_api_event_broadcast_after_cb,
 923         .hook_api_get_event_loop = hook_api_get_event_loop_cb,
 924         .hook_api_get_user_bus = hook_api_get_user_bus_cb,
 925         .hook_api_get_system_bus = hook_api_get_system_bus_cb,
 926         .hook_api_vverbose = hook_api_vverbose_cb,
 927         .hook_api_event_make = hook_api_event_make_cb,
 928         .hook_api_rootdir_get_fd = hook_api_rootdir_get_fd_cb,
 929         .hook_api_rootdir_open_locale = hook_api_rootdir_open_locale_cb,
 930         .hook_api_queue_job = hook_api_queue_job_cb,
 931         .hook_api_legacy_unstore_req = hook_api_unstore_req_cb,
 932         .hook_api_require_api = hook_api_require_api_cb,
 933         .hook_api_require_api_result = hook_api_require_api_result_cb,
 934         .hook_api_add_alias = hook_api_add_alias_cb,
 935         .hook_api_start_before = hook_api_start_before_cb,
 936         .hook_api_start_after = hook_api_start_after_cb,
 937         .hook_api_on_event_before = hook_api_on_event_before_cb,
 938         .hook_api_on_event_after = hook_api_on_event_after_cb,
 939         .hook_api_call = hook_api_call_cb,
 940         .hook_api_call_result = hook_api_call_result_cb,
 941         .hook_api_callsync = hook_api_callsync_cb,
 942         .hook_api_callsync_result = hook_api_callsync_result_cb,
 943         .hook_api_new_api_before = hook_api_new_api_before_cb,
 944         .hook_api_new_api_after = hook_api_new_api_after_cb,
 945         .hook_api_api_set_verbs_v2 = hook_api_api_set_verbs_v2_cb,
 946         .hook_api_api_set_verbs_v3 = hook_api_api_set_verbs_v3_cb,
 947         .hook_api_api_add_verb = hook_api_api_add_verb_cb,
 948         .hook_api_api_del_verb = hook_api_api_del_verb_cb,
 949         .hook_api_api_set_on_event = hook_api_api_set_on_event_cb,
 950         .hook_api_api_set_on_init = hook_api_api_set_on_init_cb,
 951         .hook_api_api_seal = hook_api_api_seal_cb,
 952         .hook_api_event_handler_add = hook_api_event_handler_add_cb,
 953         .hook_api_event_handler_del = hook_api_event_handler_del_cb,
 954         .hook_api_class_provide = hook_api_class_provide_cb,
 955         .hook_api_class_require = hook_api_class_require_cb,
 956         .hook_api_delete_api = hook_api_delete_api_cb,
 957         .hook_api_on_event_handler_before = hook_api_on_event_handler_before_cb,
 958         .hook_api_on_event_handler_after = hook_api_on_event_handler_after_cb,
 959         .hook_api_settings = hook_api_settings_cb,
 960 };
 961
 962 /******************************************************************************
 963  * section: hooks for tracing daemon interface (export)
 964  *****************************************************************************/
 965
 966 #define _HOOK_API_2_(flag,func,...)   \
 967         struct afb_hook_api *hook; \
 968         struct afb_hookid hookid; \
 969         const char *apiname = afb_export_apiname(export); \
 970         pthread_rwlock_rdlock(&rwlock); \
 971         init_hookid(&hookid); \
 972         hook = list_of_api_hooks; \
 973         while (hook) { \
 974                 if (hook->refcount \
 975                  && hook->itf->hook_api_##func \
 976                  && (hook->flags & afb_hook_flag_api_##flag) != 0 \
 977                  && MATCH_API(hook->api, apiname)) { \
 978                         hook->itf->hook_api_##func(hook->closure, &hookid, __VA_ARGS__); \
 979                 } \
 980                 hook = hook->next; \
 981         } \
 982         pthread_rwlock_unlock(&rwlock);
 983
 984 #define _HOOK_API_(what,...)   _HOOK_API_2_(what,what,__VA_ARGS__)
 985
 986 void afb_hook_api_event_broadcast_before(const struct afb_export *export, const char *name, struct json_object *object)
 987 {
 988         _HOOK_API_2_(event_broadcast, event_broadcast_before, export, name, object);
 989 }
 990
 991 int afb_hook_api_event_broadcast_after(const struct afb_export *export, const char *name, struct json_object *object, int result)
 992 {
 993         _HOOK_API_2_(event_broadcast, event_broadcast_after, export, name, object, result);
 994         return result;
 995 }
 996
 997 struct sd_event *afb_hook_api_get_event_loop(const struct afb_export *export, struct sd_event *result)
 998 {
 999         _HOOK_API_(get_event_loop, export, result);
1000         return result;
1001 }
1002
1003 struct sd_bus *afb_hook_api_get_user_bus(const struct afb_export *export, struct sd_bus *result)
1004 {
1005         _HOOK_API_(get_user_bus, export, result);
1006         return result;
1007 }
1008
1009 struct sd_bus *afb_hook_api_get_system_bus(const struct afb_export *export, struct sd_bus *result)
1010 {
1011         _HOOK_API_(get_system_bus, export, result);
1012         return result;
1013 }
1014
1015 void afb_hook_api_vverbose(const struct afb_export *export, int level, const char *file, int line, const char *function, const char *fmt, va_list args)
1016 {
1017         _HOOK_API_(vverbose, export, level, file, line, function, fmt, args);
1018 }
1019
1020 struct afb_event_x2 *afb_hook_api_event_make(const struct afb_export *export, const char *name, struct afb_event_x2 *result)
1021 {
1022         _HOOK_API_(event_make, export, name, result);
1023         return result;
1024 }
1025
1026 int afb_hook_api_rootdir_get_fd(const struct afb_export *export, int result)
1027 {
1028         _HOOK_API_(rootdir_get_fd, export, result);
1029         return result;
1030 }
1031
1032 int afb_hook_api_rootdir_open_locale(const struct afb_export *export, const char *filename, int flags, const char *locale, int result)
1033 {
1034         _HOOK_API_(rootdir_open_locale, export, filename, flags, locale, result);
1035         return result;
1036 }
1037
1038 int afb_hook_api_queue_job(const struct afb_export *export, void (*callback)(int signum, void *arg), void *argument, void *group, int timeout, int result)
1039 {
1040         _HOOK_API_(queue_job, export, callback, argument, group, timeout, result);
1041         return result;
1042 }
1043
1044 void afb_hook_api_legacy_unstore_req(const struct afb_export *export, struct afb_stored_req *sreq)
1045 {
1046         _HOOK_API_(legacy_unstore_req, export, sreq);
1047 }
1048
1049 void afb_hook_api_require_api(const struct afb_export *export, const char *name, int initialized)
1050 {
1051         _HOOK_API_(require_api, export, name, initialized);
1052 }
1053
1054 int afb_hook_api_require_api_result(const struct afb_export *export, const char *name, int initialized, int result)
1055 {
1056         _HOOK_API_2_(require_api, require_api_result, export, name, initialized, result);
1057         return result;
1058 }
1059
1060 int afb_hook_api_add_alias(const struct afb_export *export, const char *api, const char *alias, int result)
1061 {
1062         _HOOK_API_(add_alias, export, api, alias, result);
1063         return result;
1064 }
1065
1066 void afb_hook_api_start_before(const struct afb_export *export)
1067 {
1068         _HOOK_API_2_(start, start_before, export);
1069 }
1070
1071 int afb_hook_api_start_after(const struct afb_export *export, int status)
1072 {
1073         _HOOK_API_2_(start, start_after, export, status);
1074         return status;
1075 }
1076
1077 void afb_hook_api_on_event_before(const struct afb_export *export, const char *event, int event_x2, struct json_object *object)
1078 {
1079         _HOOK_API_2_(on_event, on_event_before, export, event, event_x2, object);
1080 }
1081
1082 void afb_hook_api_on_event_after(const struct afb_export *export, const char *event, int event_x2, struct json_object *object)
1083 {
1084         _HOOK_API_2_(on_event, on_event_after, export, event, event_x2, object);
1085 }
1086
1087 void afb_hook_api_call(const struct afb_export *export, const char *api, const char *verb, struct json_object *args)
1088 {
1089         _HOOK_API_(call, export, api, verb, args);
1090 }
1091
1092 void afb_hook_api_call_result(const struct afb_export *export, struct json_object *object, const char*error, const char *info)
1093 {
1094         _HOOK_API_2_(call, call_result, export, object, error, info);
1095
1096 }
1097
1098 void afb_hook_api_callsync(const struct afb_export *export, const char *api, const char *verb, struct json_object *args)
1099 {
1100         _HOOK_API_(callsync, export, api, verb, args);
1101 }
1102
1103 int afb_hook_api_callsync_result(const struct afb_export *export, int status, struct json_object *object, const char *error, const char *info)
1104 {
1105         _HOOK_API_2_(callsync, callsync_result, export, status, object, error, info);
1106         return status;
1107 }
1108
1109 void afb_hook_api_new_api_before(const struct afb_export *export, const char *api, const char *info, int noconcurrency)
1110 {
1111         _HOOK_API_2_(new_api, new_api_before, export, api, info, noconcurrency);
1112 }
1113
1114 int afb_hook_api_new_api_after(const struct afb_export *export, int result, const char *api)
1115 {
1116         _HOOK_API_2_(new_api, new_api_after, export, result, api);
1117         return result;
1118 }
1119
1120 int afb_hook_api_api_set_verbs_v2(const struct afb_export *export, int result, const struct afb_verb_v2 *verbs)
1121 {
1122         _HOOK_API_2_(api_set_verbs, api_set_verbs_v2, export, result, verbs);
1123         return result;
1124 }
1125
1126 int afb_hook_api_api_set_verbs_v3(const struct afb_export *export, int result, const struct afb_verb_v3 *verbs)
1127 {
1128         _HOOK_API_2_(api_set_verbs, api_set_verbs_v3, export, result, verbs);
1129         return result;
1130 }
1131
1132 int afb_hook_api_api_add_verb(const struct afb_export *export, int result, const char *verb, const char *info, int glob)
1133 {
1134         _HOOK_API_(api_add_verb, export, result, verb, info, glob);
1135         return result;
1136 }
1137
1138 int afb_hook_api_api_del_verb(const struct afb_export *export, int result, const char *verb)
1139 {
1140         _HOOK_API_(api_del_verb, export, result, verb);
1141         return result;
1142 }
1143
1144 int afb_hook_api_api_set_on_event(const struct afb_export *export, int result)
1145 {
1146         _HOOK_API_(api_set_on_event, export, result);
1147         return result;
1148 }
1149
1150 int afb_hook_api_api_set_on_init(const struct afb_export *export, int result)
1151 {
1152         _HOOK_API_(api_set_on_init, export, result);
1153         return result;
1154 }
1155
1156 void afb_hook_api_api_seal(const struct afb_export *export)
1157 {
1158         _HOOK_API_(api_seal, export);
1159 }
1160
1161 int afb_hook_api_event_handler_add(const struct afb_export *export, int result, const char *pattern)
1162 {
1163         _HOOK_API_(event_handler_add, export, result, pattern);
1164         return result;
1165 }
1166 int afb_hook_api_event_handler_del(const struct afb_export *export, int result, const char *pattern)
1167 {
1168         _HOOK_API_(event_handler_del, export, result, pattern);
1169         return result;
1170 }
1171 int afb_hook_api_class_provide(const struct afb_export *export, int result, const char *name)
1172 {
1173         _HOOK_API_(class_provide, export, result, name);
1174         return result;
1175 }
1176 int afb_hook_api_class_require(const struct afb_export *export, int result, const char *name)
1177 {
1178         _HOOK_API_(class_require, export, result, name);
1179         return result;
1180 }
1181
1182 int afb_hook_api_delete_api(const struct afb_export *export, int result)
1183 {
1184         _HOOK_API_(delete_api, export, result);
1185         return result;
1186 }
1187
1188 void afb_hook_api_on_event_handler_before(const struct afb_export *export, const char *event, int event_x2, struct json_object *object, const char *pattern)
1189 {
1190         _HOOK_API_2_(on_event_handler, on_event_handler_before, export, event, event_x2, object, pattern);
1191 }
1192
1193 void afb_hook_api_on_event_handler_after(const struct afb_export *export, const char *event, int event_x2, struct json_object *object, const char *pattern)
1194 {
1195         _HOOK_API_2_(on_event_handler, on_event_handler_after, export, event, event_x2, object, pattern);
1196 }
1197
1198 struct json_object *afb_hook_api_settings(const struct afb_export *export, struct json_object *object)
1199 {
1200         _HOOK_API_(settings, export, object);
1201         return object;
1202 }
1203
1204 /******************************************************************************
1205  * section: hooking export
1206  *****************************************************************************/
1207
1208 int afb_hook_flags_api(const char *api)
1209 {
1210         int flags;
1211         struct afb_hook_api *hook;
1212
1213         flags = 0;
1214         pthread_rwlock_rdlock(&rwlock);
1215         hook = list_of_api_hooks;
1216         while (hook) {
1217                 if (!api || MATCH_API(hook->api, api))
1218                         flags |= hook->flags;
1219                 hook = hook->next;
1220         }
1221         pthread_rwlock_unlock(&rwlock);
1222         return flags;
1223 }
1224
1225 struct afb_hook_api *afb_hook_create_api(const char *api, int flags, struct afb_hook_api_itf *itf, void *closure)
1226 {
1227         struct afb_hook_api *hook;
1228
1229         /* alloc the result */
1230         hook = calloc(1, sizeof *hook);
1231         if (hook == NULL)
1232                 return NULL;
1233
1234         /* get a copy of the names */
1235         hook->api = api ? strdup(api) : NULL;
1236         if (api && !hook->api) {
1237                 free(hook);
1238                 return NULL;
1239         }
1240
1241         /* initialise the rest */
1242         hook->refcount = 1;
1243         hook->flags = flags;
1244         hook->itf = itf ? itf : &hook_api_default_itf;
1245         hook->closure = closure;
1246
1247         /* record the hook */
1248         pthread_mutex_lock(&mutex);
1249         hook->next = list_of_api_hooks;
1250         list_of_api_hooks = hook;
1251         pthread_mutex_unlock(&mutex);
1252
1253         /* returns it */
1254         return hook;
1255 }
1256
1257 struct afb_hook_api *afb_hook_addref_api(struct afb_hook_api *hook)
1258 {
1259         __atomic_add_fetch(&hook->refcount, 1, __ATOMIC_RELAXED);
1260         return hook;
1261 }
1262
1263 static void hook_clean_api()
1264 {
1265         struct afb_hook_api **prv, *hook, *head;
1266
1267         if (pthread_rwlock_trywrlock(&rwlock) == 0) {
1268                 /* unlink under mutex */
1269                 head = NULL;
1270                 pthread_mutex_lock(&mutex);
1271                 prv = &list_of_api_hooks;
1272                 while ((hook = *prv)) {
1273                         if (hook->refcount)
1274                                 prv = &(*prv)->next;
1275                         else {
1276                                 *prv = hook->next;
1277                                 hook->next = head;
1278                                 head = hook;
1279                         }
1280                 }
1281                 pthread_mutex_unlock(&mutex);
1282                 pthread_rwlock_unlock(&rwlock);
1283
1284                 /* free found hooks */
1285                 while((hook = head)) {
1286                         head = hook->next;
1287                         free(hook->api);
1288                         free(hook);
1289                 }
1290         }
1291 }
1292
1293 void afb_hook_unref_api(struct afb_hook_api *hook)
1294 {
1295         if (hook && !__atomic_sub_fetch(&hook->refcount, 1, __ATOMIC_RELAXED))
1296                 hook_clean_api();
1297 }
1298
1299 /******************************************************************************
1300  * section: default callbacks for tracing service interface (evt)
1301  *****************************************************************************/
1302
1303 static void _hook_evt_(const char *evt, int id, const char *format, ...)
1304 {
1305         va_list ap;
1306         va_start(ap, format);
1307         _hook_("evt-%s:%d", format, ap, evt, id);
1308         va_end(ap);
1309 }
1310
1311 static void hook_evt_create_cb(void *closure, const struct afb_hookid *hookid, const char *evt, int id)
1312 {
1313         _hook_evt_(evt, id, "create");
1314 }
1315
1316 static void hook_evt_push_before_cb(void *closure, const struct afb_hookid *hookid, const char *evt, int id, struct json_object *obj)
1317 {
1318         _hook_evt_(evt, id, "push.before(%s)", json_object_to_json_string_ext(obj, JSON_C_TO_STRING_NOSLASHESCAPE));
1319 }
1320
1321
1322 static void hook_evt_push_after_cb(void *closure, const struct afb_hookid *hookid, const char *evt, int id, struct json_object *obj, int result)
1323 {
1324         _hook_evt_(evt, id, "push.after(%s) -> %d", json_object_to_json_string_ext(obj, JSON_C_TO_STRING_NOSLASHESCAPE), result);
1325 }
1326
1327 static void hook_evt_broadcast_before_cb(void *closure, const struct afb_hookid *hookid, const char *evt, int id, struct json_object *obj)
1328 {
1329         _hook_evt_(evt, id, "broadcast.before(%s)", json_object_to_json_string_ext(obj, JSON_C_TO_STRING_NOSLASHESCAPE));
1330 }
1331
1332 static void hook_evt_broadcast_after_cb(void *closure, const struct afb_hookid *hookid, const char *evt, int id, struct json_object *obj, int result)
1333 {
1334         _hook_evt_(evt, id, "broadcast.after(%s) -> %d", json_object_to_json_string_ext(obj, JSON_C_TO_STRING_NOSLASHESCAPE), result);
1335 }
1336
1337 static void hook_evt_name_cb(void *closure, const struct afb_hookid *hookid, const char *evt, int id, const char *result)
1338 {
1339         _hook_evt_(evt, id, "name -> %s", result);
1340 }
1341
1342 static void hook_evt_addref_cb(void *closure, const struct afb_hookid *hookid, const char *evt, int id)
1343 {
1344         _hook_evt_(evt, id, "addref");
1345 }
1346
1347 static void hook_evt_unref_cb(void *closure, const struct afb_hookid *hookid, const char *evt, int id)
1348 {
1349         _hook_evt_(evt, id, "unref");
1350 }
1351
1352 static struct afb_hook_evt_itf hook_evt_default_itf = {
1353         .hook_evt_create = hook_evt_create_cb,
1354         .hook_evt_push_before = hook_evt_push_before_cb,
1355         .hook_evt_push_after = hook_evt_push_after_cb,
1356         .hook_evt_broadcast_before = hook_evt_broadcast_before_cb,
1357         .hook_evt_broadcast_after = hook_evt_broadcast_after_cb,
1358         .hook_evt_name = hook_evt_name_cb,
1359         .hook_evt_addref = hook_evt_addref_cb,
1360         .hook_evt_unref = hook_evt_unref_cb
1361 };
1362
1363 /******************************************************************************
1364  * section: hooks for tracing events interface (evt)
1365  *****************************************************************************/
1366
1367 #define _HOOK_EVT_(what,...)   \
1368         struct afb_hook_evt *hook; \
1369         struct afb_hookid hookid; \
1370         pthread_rwlock_rdlock(&rwlock); \
1371         init_hookid(&hookid); \
1372         hook = list_of_evt_hooks; \
1373         while (hook) { \
1374                 if (hook->refcount \
1375                  && hook->itf->hook_evt_##what \
1376                  && (hook->flags & afb_hook_flag_evt_##what) != 0 \
1377                  && MATCH_EVENT(hook->pattern, evt)) { \
1378                         hook->itf->hook_evt_##what(hook->closure, &hookid, __VA_ARGS__); \
1379                 } \
1380                 hook = hook->next; \
1381         } \
1382         pthread_rwlock_unlock(&rwlock);
1383
1384 void afb_hook_evt_create(const char *evt, int id)
1385 {
1386         _HOOK_EVT_(create, evt, id);
1387 }
1388
1389 void afb_hook_evt_push_before(const char *evt, int id, struct json_object *obj)
1390 {
1391         _HOOK_EVT_(push_before, evt, id, obj);
1392 }
1393
1394 int afb_hook_evt_push_after(const char *evt, int id, struct json_object *obj, int result)
1395 {
1396         _HOOK_EVT_(push_after, evt, id, obj, result);
1397         return result;
1398 }
1399
1400 void afb_hook_evt_broadcast_before(const char *evt, int id, struct json_object *obj)
1401 {
1402         _HOOK_EVT_(broadcast_before, evt, id, obj);
1403 }
1404
1405 int afb_hook_evt_broadcast_after(const char *evt, int id, struct json_object *obj, int result)
1406 {
1407         _HOOK_EVT_(broadcast_after, evt, id, obj, result);
1408         return result;
1409 }
1410
1411 void afb_hook_evt_name(const char *evt, int id, const char *result)
1412 {
1413         _HOOK_EVT_(name, evt, id, result);
1414 }
1415
1416 void afb_hook_evt_addref(const char *evt, int id)
1417 {
1418         _HOOK_EVT_(addref, evt, id);
1419 }
1420
1421 void afb_hook_evt_unref(const char *evt, int id)
1422 {
1423         _HOOK_EVT_(unref, evt, id);
1424 }
1425
1426 /******************************************************************************
1427  * section: hooking services (evt)
1428  *****************************************************************************/
1429
1430 int afb_hook_flags_evt(const char *name)
1431 {
1432         int flags;
1433         struct afb_hook_evt *hook;
1434
1435         flags = 0;
1436         pthread_rwlock_rdlock(&rwlock);
1437         hook = list_of_evt_hooks;
1438         while (hook) {
1439                 if (!name || MATCH_EVENT(hook->pattern, name))
1440                         flags |= hook->flags;
1441                 hook = hook->next;
1442         }
1443         pthread_rwlock_unlock(&rwlock);
1444         return flags;
1445 }
1446
1447 struct afb_hook_evt *afb_hook_create_evt(const char *pattern, int flags, struct afb_hook_evt_itf *itf, void *closure)
1448 {
1449         struct afb_hook_evt *hook;
1450
1451         /* alloc the result */
1452         hook = calloc(1, sizeof *hook);
1453         if (hook == NULL)
1454                 return NULL;
1455
1456         /* get a copy of the names */
1457         hook->pattern = pattern ? strdup(pattern) : NULL;
1458         if (pattern && !hook->pattern) {
1459                 free(hook);
1460                 return NULL;
1461         }
1462
1463         /* initialise the rest */
1464         hook->refcount = 1;
1465         hook->flags = flags;
1466         hook->itf = itf ? itf : &hook_evt_default_itf;
1467         hook->closure = closure;
1468
1469         /* record the hook */
1470         pthread_mutex_lock(&mutex);
1471         hook->next = list_of_evt_hooks;
1472         list_of_evt_hooks = hook;
1473         pthread_mutex_unlock(&mutex);
1474
1475         /* returns it */
1476         return hook;
1477 }
1478
1479 struct afb_hook_evt *afb_hook_addref_evt(struct afb_hook_evt *hook)
1480 {
1481         __atomic_add_fetch(&hook->refcount, 1, __ATOMIC_RELAXED);
1482         return hook;
1483 }
1484
1485 static void hook_clean_evt()
1486 {
1487         struct afb_hook_evt **prv, *hook, *head;
1488
1489         if (pthread_rwlock_trywrlock(&rwlock) == 0) {
1490                 /* unlink under mutex */
1491                 head = NULL;
1492                 pthread_mutex_lock(&mutex);
1493                 prv = &list_of_evt_hooks;
1494                 while ((hook = *prv)) {
1495                         if (hook->refcount)
1496                                 prv = &(*prv)->next;
1497                         else {
1498                                 *prv = hook->next;
1499                                 hook->next = head;
1500                                 head = hook;
1501                         }
1502                 }
1503                 pthread_mutex_unlock(&mutex);
1504                 pthread_rwlock_unlock(&rwlock);
1505
1506                 /* free found hooks */
1507                 while((hook = head)) {
1508                         head = hook->next;
1509                         free(hook->pattern);
1510                         free(hook);
1511                 }
1512         }
1513 }
1514
1515 void afb_hook_unref_evt(struct afb_hook_evt *hook)
1516 {
1517         if (hook && !__atomic_sub_fetch(&hook->refcount, 1, __ATOMIC_RELAXED))
1518                 hook_clean_evt();
1519 }
1520
1521 /******************************************************************************
1522  * section: default callbacks for sessions (session)
1523  *****************************************************************************/
1524
1525 static void _hook_session_(struct afb_session *session, const char *format, ...)
1526 {
1527         va_list ap;
1528         va_start(ap, format);
1529         _hook_("session-%s", format, ap, afb_session_uuid(session));
1530         va_end(ap);
1531 }
1532
1533 static void hook_session_create_cb(void *closure, const struct afb_hookid *hookid, struct afb_session *session)
1534 {
1535         _hook_session_(session, "create -> token=%s", afb_session_token(session));
1536 }
1537
1538 static void hook_session_close_cb(void *closure, const struct afb_hookid *hookid, struct afb_session *session)
1539 {
1540         _hook_session_(session, "close");
1541 }
1542
1543 static void hook_session_destroy_cb(void *closure, const struct afb_hookid *hookid, struct afb_session *session)
1544 {
1545         _hook_session_(session, "destroy");
1546 }
1547
1548 static void hook_session_renew_cb(void *closure, const struct afb_hookid *hookid, struct afb_session *session)
1549 {
1550         _hook_session_(session, "renew -> token=%s", afb_session_token(session));
1551 }
1552
1553 static void hook_session_addref_cb(void *closure, const struct afb_hookid *hookid, struct afb_session *session)
1554 {
1555         _hook_session_(session, "addref");
1556 }
1557
1558 static void hook_session_unref_cb(void *closure, const struct afb_hookid *hookid, struct afb_session *session)
1559 {
1560         _hook_session_(session, "unref");
1561 }
1562
1563 static struct afb_hook_session_itf hook_session_default_itf = {
1564         .hook_session_create = hook_session_create_cb,
1565         .hook_session_close = hook_session_close_cb,
1566         .hook_session_destroy = hook_session_destroy_cb,
1567         .hook_session_renew = hook_session_renew_cb,
1568         .hook_session_addref = hook_session_addref_cb,
1569         .hook_session_unref = hook_session_unref_cb
1570 };
1571
1572 /******************************************************************************
1573  * section: hooks for tracing sessions (session)
1574  *****************************************************************************/
1575
1576 #define _HOOK_SESSION_(what,...)   \
1577         struct afb_hook_session *hook; \
1578         struct afb_hookid hookid; \
1579         const char *sessid = 0; \
1580         pthread_rwlock_rdlock(&rwlock); \
1581         init_hookid(&hookid); \
1582         hook = list_of_session_hooks; \
1583         while (hook) { \
1584                 if (hook->refcount \
1585                  && hook->itf->hook_session_##what \
1586                  && (hook->flags & afb_hook_flag_session_##what) != 0 \
1587                  && MATCH_SESSION(hook->pattern, (sessid?:(sessid=afb_session_uuid(session))))) { \
1588                         hook->itf->hook_session_##what(hook->closure, &hookid, __VA_ARGS__); \
1589                 } \
1590                 hook = hook->next; \
1591         } \
1592         pthread_rwlock_unlock(&rwlock);
1593
1594 void afb_hook_session_create(struct afb_session *session)
1595 {
1596         _HOOK_SESSION_(create, session);
1597 }
1598
1599 void afb_hook_session_close(struct afb_session *session)
1600 {
1601         _HOOK_SESSION_(close, session);
1602 }
1603
1604 void afb_hook_session_destroy(struct afb_session *session)
1605 {
1606         _HOOK_SESSION_(destroy, session);
1607 }
1608
1609 void afb_hook_session_renew(struct afb_session *session)
1610 {
1611         _HOOK_SESSION_(renew, session);
1612 }
1613
1614 void afb_hook_session_addref(struct afb_session *session)
1615 {
1616         _HOOK_SESSION_(addref, session);
1617 }
1618
1619 void afb_hook_session_unref(struct afb_session *session)
1620 {
1621         _HOOK_SESSION_(unref, session);
1622 }
1623
1624
1625 /******************************************************************************
1626  * section: hooking sessions (session)
1627  *****************************************************************************/
1628
1629 struct afb_hook_session *afb_hook_create_session(const char *pattern, int flags, struct afb_hook_session_itf *itf, void *closure)
1630 {
1631         struct afb_hook_session *hook;
1632
1633         /* alloc the result */
1634         hook = calloc(1, sizeof *hook);
1635         if (hook == NULL)
1636                 return NULL;
1637
1638         /* get a copy of the names */
1639         hook->pattern = pattern ? strdup(pattern) : NULL;
1640         if (pattern && !hook->pattern) {
1641                 free(hook);
1642                 return NULL;
1643         }
1644
1645         /* initialise the rest */
1646         hook->refcount = 1;
1647         hook->flags = flags;
1648         hook->itf = itf ? itf : &hook_session_default_itf;
1649         hook->closure = closure;
1650
1651         /* record the hook */
1652         pthread_mutex_lock(&mutex);
1653         hook->next = list_of_session_hooks;
1654         list_of_session_hooks = hook;
1655         pthread_mutex_unlock(&mutex);
1656
1657         /* returns it */
1658         return hook;
1659 }
1660
1661 struct afb_hook_session *afb_hook_addref_session(struct afb_hook_session *hook)
1662 {
1663         __atomic_add_fetch(&hook->refcount, 1, __ATOMIC_RELAXED);
1664         return hook;
1665 }
1666
1667 static void hook_clean_session()
1668 {
1669         struct afb_hook_session **prv, *hook, *head;
1670
1671         if (pthread_rwlock_trywrlock(&rwlock) == 0) {
1672                 /* unlink under mutex */
1673                 head = NULL;
1674                 pthread_mutex_lock(&mutex);
1675                 prv = &list_of_session_hooks;
1676                 while ((hook = *prv)) {
1677                         if (hook->refcount)
1678                                 prv = &(*prv)->next;
1679                         else {
1680                                 *prv = hook->next;
1681                                 hook->next = head;
1682                                 head = hook;
1683                         }
1684                 }
1685                 pthread_mutex_unlock(&mutex);
1686                 pthread_rwlock_unlock(&rwlock);
1687
1688                 /* free found hooks */
1689                 while((hook = head)) {
1690                         head = hook->next;
1691                         free(hook->pattern);
1692                         free(hook);
1693                 }
1694         }
1695 }
1696
1697 void afb_hook_unref_session(struct afb_hook_session *hook)
1698 {
1699         if (hook && !__atomic_sub_fetch(&hook->refcount, 1, __ATOMIC_RELAXED))
1700                 hook_clean_session();
1701 }
1702
1703 /******************************************************************************
1704  * section: default callbacks for globals (global)
1705  *****************************************************************************/
1706
1707 static void _hook_global_(const char *format, ...)
1708 {
1709         va_list ap;
1710         va_start(ap, format);
1711         _hook_("global", format, ap);
1712         va_end(ap);
1713 }
1714
1715 static void hook_global_vverbose_cb(void *closure, const struct afb_hookid *hookid, int level, const char *file, int line, const char *func, const char *fmt, va_list args)
1716 {
1717         int len;
1718         char *msg;
1719         va_list ap;
1720
1721         va_copy(ap, args);
1722         len = vasprintf(&msg, fmt, ap);
1723         va_end(ap);
1724
1725         if (len < 0)
1726                 _hook_global_("vverbose(%d:%s, %s, %d, %s) -> %s ? ? ?", level, verbose_name_of_level(level), file, line, func, fmt);
1727         else {
1728                 _hook_global_("vverbose(%d:%s, %s, %d, %s) -> %s", level, verbose_name_of_level(level), file, line, func, msg);
1729                 free(msg);
1730         }
1731 }
1732
1733 static struct afb_hook_global_itf hook_global_default_itf = {
1734         .hook_global_vverbose = hook_global_vverbose_cb
1735 };
1736
1737 /******************************************************************************
1738  * section: hooks for tracing globals (global)
1739  *****************************************************************************/
1740
1741 #define _HOOK_GLOBAL_(what,...)   \
1742         struct afb_hook_global *hook; \
1743         struct afb_hookid hookid; \
1744         pthread_rwlock_rdlock(&rwlock); \
1745         init_hookid(&hookid); \
1746         hook = list_of_global_hooks; \
1747         while (hook) { \
1748                 if (hook->refcount \
1749                  && hook->itf->hook_global_##what \
1750                  && (hook->flags & afb_hook_flag_global_##what) != 0) { \
1751                         hook->itf->hook_global_##what(hook->closure, &hookid, __VA_ARGS__); \
1752                 } \
1753                 hook = hook->next; \
1754         } \
1755         pthread_rwlock_unlock(&rwlock);
1756
1757 static void afb_hook_global_vverbose(int level, const char *file, int line, const char *func, const char *fmt, va_list args)
1758 {
1759         _HOOK_GLOBAL_(vverbose, level, file ?: "?", line, func ?: "?", fmt ?: "", args);
1760 }
1761
1762 /******************************************************************************
1763  * section: hooking globals (global)
1764  *****************************************************************************/
1765
1766 static void update_global()
1767 {
1768         struct afb_hook_global *hook;
1769         int flags = 0;
1770
1771         pthread_rwlock_rdlock(&rwlock);
1772         hook = list_of_global_hooks;
1773         while (hook) {
1774                 if (hook->refcount)
1775                         flags = hook->flags;
1776                 hook = hook->next;
1777         }
1778         verbose_observer = (flags & afb_hook_flag_global_vverbose) ? afb_hook_global_vverbose : NULL;
1779         pthread_rwlock_unlock(&rwlock);
1780 }
1781
1782 struct afb_hook_global *afb_hook_create_global(int flags, struct afb_hook_global_itf *itf, void *closure)
1783 {
1784         struct afb_hook_global *hook;
1785
1786         /* alloc the result */
1787         hook = calloc(1, sizeof *hook);
1788         if (hook == NULL)
1789                 return NULL;
1790
1791         /* initialise the rest */
1792         hook->refcount = 1;
1793         hook->flags = flags;
1794         hook->itf = itf ? itf : &hook_global_default_itf;
1795         hook->closure = closure;
1796
1797         /* record the hook */
1798         pthread_mutex_lock(&mutex);
1799         hook->next = list_of_global_hooks;
1800         list_of_global_hooks = hook;
1801         pthread_mutex_unlock(&mutex);
1802
1803         /* update hooking */
1804         update_global();
1805
1806         /* returns it */
1807         return hook;
1808 }
1809
1810 struct afb_hook_global *afb_hook_addref_global(struct afb_hook_global *hook)
1811 {
1812         __atomic_add_fetch(&hook->refcount, 1, __ATOMIC_RELAXED);
1813         return hook;
1814 }
1815
1816 static void hook_clean_global()
1817 {
1818         struct afb_hook_global **prv, *hook, *head;
1819
1820         if (pthread_rwlock_trywrlock(&rwlock) == 0) {
1821                 /* unlink under mutex */
1822                 head = NULL;
1823                 pthread_mutex_lock(&mutex);
1824                 prv = &list_of_global_hooks;
1825                 while ((hook = *prv)) {
1826                         if (hook->refcount)
1827                                 prv = &(*prv)->next;
1828                         else {
1829                                 *prv = hook->next;
1830                                 hook->next = head;
1831                                 head = hook;
1832                         }
1833                 }
1834                 pthread_mutex_unlock(&mutex);
1835                 pthread_rwlock_unlock(&rwlock);
1836
1837                 /* free found hooks */
1838                 while((hook = head)) {
1839                         head = hook->next;
1840                         free(hook);
1841                 }
1842         }
1843 }
1844
1845 void afb_hook_unref_global(struct afb_hook_global *hook)
1846 {
1847         if (hook && !__atomic_sub_fetch(&hook->refcount, 1, __ATOMIC_RELAXED)) {
1848                 /* update hooking */
1849                 update_global();
1850                 hook_clean_global();
1851         }
1852 }
1853
1854 #endif /* WITH_AFB_HOOK *******************************************************/