src/afb-hook.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
  20 #include <limits.h>
  21 #include <stdio.h>
  22 #include <stdarg.h>
  23 #include <string.h>
  24 #include <pthread.h>
  25 #include <unistd.h>
  26 #include <fnmatch.h>
  27
  28 #include <json-c/json.h>
  29
  30 #include <afb/afb-req-common.h>
  31 #include <afb/afb-event-itf.h>
  32
  33 #include "afb-context.h"
  34 #include "afb-hook.h"
  35 #include "afb-session.h"
  36 #include "afb-cred.h"
  37 #include "afb-xreq.h"
  38 #include "afb-ditf.h"
  39 #include "afb-svc.h"
  40 #include "afb-evt.h"
  41 #include "verbose.h"
  42
  43 /**
  44  * Definition of a hook for xreq
  45  */
  46 struct afb_hook_xreq {
  47         struct afb_hook_xreq *next; /**< next hook */
  48         unsigned refcount; /**< reference count */
  49         char *api; /**< api hooked or NULL for any */
  50         char *verb; /**< verb hooked or NULL for any */
  51         struct afb_session *session; /**< session hooked or NULL if any */
  52         unsigned flags; /**< hook flags */
  53         struct afb_hook_xreq_itf *itf; /**< interface of hook */
  54         void *closure; /**< closure for callbacks */
  55 };
  56
  57 /**
  58  * Definition of a hook for ditf
  59  */
  60 struct afb_hook_ditf {
  61         struct afb_hook_ditf *next; /**< next hook */
  62         unsigned refcount; /**< reference count */
  63         char *api; /**< api hooked or NULL for any */
  64         unsigned flags; /**< hook flags */
  65         struct afb_hook_ditf_itf *itf; /**< interface of hook */
  66         void *closure; /**< closure for callbacks */
  67 };
  68
  69 /**
  70  * Definition of a hook for svc
  71  */
  72 struct afb_hook_svc {
  73         struct afb_hook_svc *next; /**< next hook */
  74         unsigned refcount; /**< reference count */
  75         char *api; /**< api hooked or NULL for any */
  76         unsigned flags; /**< hook flags */
  77         struct afb_hook_svc_itf *itf; /**< interface of hook */
  78         void *closure; /**< closure for callbacks */
  79 };
  80
  81 /**
  82  * Definition of a hook for evt
  83  */
  84 struct afb_hook_evt {
  85         struct afb_hook_evt *next; /**< next hook */
  86         unsigned refcount; /**< reference count */
  87         char *pattern; /**< event pattern name hooked or NULL for any */
  88         unsigned flags; /**< hook flags */
  89         struct afb_hook_evt_itf *itf; /**< interface of hook */
  90         void *closure; /**< closure for callbacks */
  91 };
  92
  93 /* synchronisation across threads */
  94 static pthread_rwlock_t rwlock = PTHREAD_RWLOCK_INITIALIZER;
  95
  96 /* list of hooks for xreq */
  97 static struct afb_hook_xreq *list_of_xreq_hooks = NULL;
  98
  99 /* list of hooks for ditf */
 100 static struct afb_hook_ditf *list_of_ditf_hooks = NULL;
 101
 102 /* list of hooks for svc */
 103 static struct afb_hook_svc *list_of_svc_hooks = NULL;
 104
 105 /* list of hooks for evt */
 106 static struct afb_hook_evt *list_of_evt_hooks = NULL;
 107
 108 /******************************************************************************
 109  * section: default callbacks for tracing requests
 110  *****************************************************************************/
 111
 112 static char *_pbuf_(const char *fmt, va_list args, char **palloc, char *sbuf, size_t szsbuf)
 113 {
 114         int rc;
 115         va_list cp;
 116
 117         *palloc = NULL;
 118         va_copy(cp, args);
 119         rc = vsnprintf(sbuf, szsbuf, fmt, args);
 120         if ((size_t)rc >= szsbuf) {
 121                 sbuf[szsbuf-1] = 0;
 122                 sbuf[szsbuf-2] = sbuf[szsbuf-3] = sbuf[szsbuf-4] = '.';
 123                 rc = vasprintf(palloc, fmt, cp);
 124                 if (rc >= 0)
 125                         sbuf = *palloc;
 126         }
 127         va_end(cp);
 128         return sbuf;
 129 }
 130
 131 static void _hook_(const char *fmt1, const char *fmt2, va_list arg2, ...)
 132 {
 133         char *tag, *data, *mem1, *mem2, buf1[256], buf2[2000];
 134         va_list arg1;
 135
 136         data = _pbuf_(fmt2, arg2, &mem2, buf2, sizeof buf2);
 137
 138         va_start(arg1, arg2);
 139         tag = _pbuf_(fmt1, arg1, &mem1, buf1, sizeof buf1);
 140         va_end(arg1);
 141
 142         NOTICE("[HOOK %s] %s", tag, data);
 143
 144         free(mem1);
 145         free(mem2);
 146 }
 147
 148 static void _hook_xreq_(const struct afb_xreq *xreq, const char *format, ...)
 149 {
 150         va_list ap;
 151         va_start(ap, format);
 152         _hook_("xreq-%06d:%s/%s", format, ap, xreq->hookindex, xreq->api, xreq->verb);
 153         va_end(ap);
 154 }
 155
 156 static void hook_xreq_begin_default_cb(void * closure, const struct afb_xreq *xreq)
 157 {
 158         if (!xreq->cred)
 159                 _hook_xreq_(xreq, "BEGIN");
 160         else
 161                 _hook_xreq_(xreq, "BEGIN uid=%d=%s gid=%d pid=%d label=%s id=%s",
 162                         (int)xreq->cred->uid,
 163                         xreq->cred->user,
 164                         (int)xreq->cred->gid,
 165                         (int)xreq->cred->pid,
 166                         xreq->cred->label?:"(null)",
 167                         xreq->cred->id?:"(null)"
 168                 );
 169 }
 170
 171 static void hook_xreq_end_default_cb(void * closure, const struct afb_xreq *xreq)
 172 {
 173         _hook_xreq_(xreq, "END");
 174 }
 175
 176 static void hook_xreq_json_default_cb(void * closure, const struct afb_xreq *xreq, struct json_object *obj)
 177 {
 178         _hook_xreq_(xreq, "json() -> %s", json_object_to_json_string(obj));
 179 }
 180
 181 static void hook_xreq_get_default_cb(void * closure, const struct afb_xreq *xreq, const char *name, struct afb_arg arg)
 182 {
 183         _hook_xreq_(xreq, "get(%s) -> { name: %s, value: %s, path: %s }", name, arg.name, arg.value, arg.path);
 184 }
 185
 186 static void hook_xreq_success_default_cb(void * closure, const struct afb_xreq *xreq, struct json_object *obj, const char *info)
 187 {
 188         _hook_xreq_(xreq, "success(%s, %s)", json_object_to_json_string(obj), info);
 189 }
 190
 191 static void hook_xreq_fail_default_cb(void * closure, const struct afb_xreq *xreq, const char *status, const char *info)
 192 {
 193         _hook_xreq_(xreq, "fail(%s, %s)", status, info);
 194 }
 195
 196 static void hook_xreq_context_get_default_cb(void * closure, const struct afb_xreq *xreq, void *value)
 197 {
 198         _hook_xreq_(xreq, "context_get() -> %p", value);
 199 }
 200
 201 static void hook_xreq_context_set_default_cb(void * closure, const struct afb_xreq *xreq, void *value, void (*free_value)(void*))
 202 {
 203         _hook_xreq_(xreq, "context_set(%p, %p)", value, free_value);
 204 }
 205
 206 static void hook_xreq_addref_default_cb(void * closure, const struct afb_xreq *xreq)
 207 {
 208         _hook_xreq_(xreq, "addref()");
 209 }
 210
 211 static void hook_xreq_unref_default_cb(void * closure, const struct afb_xreq *xreq)
 212 {
 213         _hook_xreq_(xreq, "unref()");
 214 }
 215
 216 static void hook_xreq_session_close_default_cb(void * closure, const struct afb_xreq *xreq)
 217 {
 218         _hook_xreq_(xreq, "session_close()");
 219 }
 220
 221 static void hook_xreq_session_set_LOA_default_cb(void * closure, const struct afb_xreq *xreq, unsigned level, int result)
 222 {
 223         _hook_xreq_(xreq, "session_set_LOA(%u) -> %d", level, result);
 224 }
 225
 226 static void hook_xreq_subscribe_default_cb(void * closure, const struct afb_xreq *xreq, struct afb_event event, int result)
 227 {
 228         _hook_xreq_(xreq, "subscribe(%s:%d) -> %d", afb_evt_event_name(event), afb_evt_event_id(event), result);
 229 }
 230
 231 static void hook_xreq_unsubscribe_default_cb(void * closure, const struct afb_xreq *xreq, struct afb_event event, int result)
 232 {
 233         _hook_xreq_(xreq, "unsubscribe(%s:%d) -> %d", afb_evt_event_name(event), afb_evt_event_id(event), result);
 234 }
 235
 236 static void hook_xreq_subcall_default_cb(void * closure, const struct afb_xreq *xreq, const char *api, const char *verb, struct json_object *args)
 237 {
 238         _hook_xreq_(xreq, "subcall(%s/%s, %s) ...", api, verb, json_object_to_json_string(args));
 239 }
 240
 241 static void hook_xreq_subcall_result_default_cb(void * closure, const struct afb_xreq *xreq, int status, struct json_object *result)
 242 {
 243         _hook_xreq_(xreq, "    ...subcall... -> %d: %s", status, json_object_to_json_string(result));
 244 }
 245
 246 static void hook_xreq_subcallsync_default_cb(void * closure, const struct afb_xreq *xreq, const char *api, const char *verb, struct json_object *args)
 247 {
 248         _hook_xreq_(xreq, "subcallsync(%s/%s, %s) ...", api, verb, json_object_to_json_string(args));
 249 }
 250
 251 static void hook_xreq_subcallsync_result_default_cb(void * closure, const struct afb_xreq *xreq, int status, struct json_object *result)
 252 {
 253         _hook_xreq_(xreq, "    ...subcallsync... -> %d: %s", status, json_object_to_json_string(result));
 254 }
 255
 256 static void hook_xreq_vverbose_default_cb(void * closure, const struct afb_xreq *xreq, int level, const char *file, int line, const char *func, const char *fmt, va_list args)
 257 {
 258         int len;
 259         char *msg;
 260         va_list ap;
 261
 262         va_copy(ap, args);
 263         len = vasprintf(&msg, fmt, ap);
 264         va_end(ap);
 265
 266         if (len < 0)
 267                 _hook_xreq_(xreq, "vverbose(%d, %s, %d, %s) -> %s ? ? ?", level, file, line, func, fmt);
 268         else {
 269                 _hook_xreq_(xreq, "vverbose(%d, %s, %d, %s) -> %s", level, file, line, func, msg);
 270                 free(msg);
 271         }
 272 }
 273
 274 static void hook_xreq_store_default_cb(void * closure, const struct afb_xreq *xreq, struct afb_stored_req *sreq)
 275 {
 276         _hook_xreq_(xreq, "store() -> %p", sreq);
 277 }
 278
 279 static void hook_xreq_unstore_default_cb(void * closure, const struct afb_xreq *xreq)
 280 {
 281         _hook_xreq_(xreq, "unstore()");
 282 }
 283
 284 static struct afb_hook_xreq_itf hook_xreq_default_itf = {
 285         .hook_xreq_begin = hook_xreq_begin_default_cb,
 286         .hook_xreq_end = hook_xreq_end_default_cb,
 287         .hook_xreq_json = hook_xreq_json_default_cb,
 288         .hook_xreq_get = hook_xreq_get_default_cb,
 289         .hook_xreq_success = hook_xreq_success_default_cb,
 290         .hook_xreq_fail = hook_xreq_fail_default_cb,
 291         .hook_xreq_context_get = hook_xreq_context_get_default_cb,
 292         .hook_xreq_context_set = hook_xreq_context_set_default_cb,
 293         .hook_xreq_addref = hook_xreq_addref_default_cb,
 294         .hook_xreq_unref = hook_xreq_unref_default_cb,
 295         .hook_xreq_session_close = hook_xreq_session_close_default_cb,
 296         .hook_xreq_session_set_LOA = hook_xreq_session_set_LOA_default_cb,
 297         .hook_xreq_subscribe = hook_xreq_subscribe_default_cb,
 298         .hook_xreq_unsubscribe = hook_xreq_unsubscribe_default_cb,
 299         .hook_xreq_subcall = hook_xreq_subcall_default_cb,
 300         .hook_xreq_subcall_result = hook_xreq_subcall_result_default_cb,
 301         .hook_xreq_subcallsync = hook_xreq_subcallsync_default_cb,
 302         .hook_xreq_subcallsync_result = hook_xreq_subcallsync_result_default_cb,
 303         .hook_xreq_vverbose = hook_xreq_vverbose_default_cb,
 304         .hook_xreq_store = hook_xreq_store_default_cb,
 305         .hook_xreq_unstore = hook_xreq_unstore_default_cb
 306 };
 307
 308 /******************************************************************************
 309  * section: hooks for tracing requests
 310  *****************************************************************************/
 311
 312 #define _HOOK_XREQ_(what,...)   \
 313         struct afb_hook_xreq *hook; \
 314         pthread_rwlock_rdlock(&rwlock); \
 315         hook = list_of_xreq_hooks; \
 316         while (hook) { \
 317                 if (hook->itf->hook_xreq_##what \
 318                  && (hook->flags & afb_hook_flag_req_##what) != 0 \
 319                  && (!hook->session || hook->session == xreq->context.session) \
 320                  && (!hook->api || !strcasecmp(hook->api, xreq->api)) \
 321                  && (!hook->verb || !strcasecmp(hook->verb, xreq->verb))) { \
 322                         hook->itf->hook_xreq_##what(hook->closure, __VA_ARGS__); \
 323                 } \
 324                 hook = hook->next; \
 325         } \
 326         pthread_rwlock_unlock(&rwlock);
 327
 328
 329 void afb_hook_xreq_begin(const struct afb_xreq *xreq)
 330 {
 331         _HOOK_XREQ_(begin, xreq);
 332 }
 333
 334 void afb_hook_xreq_end(const struct afb_xreq *xreq)
 335 {
 336         _HOOK_XREQ_(end, xreq);
 337 }
 338
 339 struct json_object *afb_hook_xreq_json(const struct afb_xreq *xreq, struct json_object *obj)
 340 {
 341         _HOOK_XREQ_(json, xreq, obj);
 342         return obj;
 343 }
 344
 345 struct afb_arg afb_hook_xreq_get(const struct afb_xreq *xreq, const char *name, struct afb_arg arg)
 346 {
 347         _HOOK_XREQ_(get, xreq, name, arg);
 348         return arg;
 349 }
 350
 351 void afb_hook_xreq_success(const struct afb_xreq *xreq, struct json_object *obj, const char *info)
 352 {
 353         _HOOK_XREQ_(success, xreq, obj, info);
 354 }
 355
 356 void afb_hook_xreq_fail(const struct afb_xreq *xreq, const char *status, const char *info)
 357 {
 358         _HOOK_XREQ_(fail, xreq, status, info);
 359 }
 360
 361 void *afb_hook_xreq_context_get(const struct afb_xreq *xreq, void *value)
 362 {
 363         _HOOK_XREQ_(context_get, xreq, value);
 364         return value;
 365 }
 366
 367 void afb_hook_xreq_context_set(const struct afb_xreq *xreq, void *value, void (*free_value)(void*))
 368 {
 369         _HOOK_XREQ_(context_set, xreq, value, free_value);
 370 }
 371
 372 void afb_hook_xreq_addref(const struct afb_xreq *xreq)
 373 {
 374         _HOOK_XREQ_(addref, xreq);
 375 }
 376
 377 void afb_hook_xreq_unref(const struct afb_xreq *xreq)
 378 {
 379         _HOOK_XREQ_(unref, xreq);
 380 }
 381
 382 void afb_hook_xreq_session_close(const struct afb_xreq *xreq)
 383 {
 384         _HOOK_XREQ_(session_close, xreq);
 385 }
 386
 387 int afb_hook_xreq_session_set_LOA(const struct afb_xreq *xreq, unsigned level, int result)
 388 {
 389         _HOOK_XREQ_(session_set_LOA, xreq, level, result);
 390         return result;
 391 }
 392
 393 int afb_hook_xreq_subscribe(const struct afb_xreq *xreq, struct afb_event event, int result)
 394 {
 395         _HOOK_XREQ_(subscribe, xreq, event, result);
 396         return result;
 397 }
 398
 399 int afb_hook_xreq_unsubscribe(const struct afb_xreq *xreq, struct afb_event event, int result)
 400 {
 401         _HOOK_XREQ_(unsubscribe, xreq, event, result);
 402         return result;
 403 }
 404
 405 void afb_hook_xreq_subcall(const struct afb_xreq *xreq, const char *api, const char *verb, struct json_object *args)
 406 {
 407         _HOOK_XREQ_(subcall, xreq, api, verb, args);
 408 }
 409
 410 void afb_hook_xreq_subcall_result(const struct afb_xreq *xreq, int status, struct json_object *result)
 411 {
 412         _HOOK_XREQ_(subcall_result, xreq, status, result);
 413 }
 414
 415 void afb_hook_xreq_subcallsync(const struct afb_xreq *xreq, const char *api, const char *verb, struct json_object *args)
 416 {
 417         _HOOK_XREQ_(subcallsync, xreq, api, verb, args);
 418 }
 419
 420 int afb_hook_xreq_subcallsync_result(const struct afb_xreq *xreq, int status, struct json_object *result)
 421 {
 422         _HOOK_XREQ_(subcallsync_result, xreq, status, result);
 423         return status;
 424 }
 425
 426 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)
 427 {
 428         _HOOK_XREQ_(vverbose, xreq, level, file ?: "?", line, func ?: "?", fmt, args);
 429 }
 430
 431 void afb_hook_xreq_store(const struct afb_xreq *xreq, struct afb_stored_req *sreq)
 432 {
 433         _HOOK_XREQ_(store, xreq, sreq);
 434 }
 435
 436 void afb_hook_xreq_unstore(const struct afb_xreq *xreq)
 437 {
 438         _HOOK_XREQ_(unstore, xreq);
 439 }
 440
 441 /******************************************************************************
 442  * section: hooking xreqs
 443  *****************************************************************************/
 444
 445 void afb_hook_init_xreq(struct afb_xreq *xreq)
 446 {
 447         static int reqindex;
 448
 449         int f, flags;
 450         int add;
 451         struct afb_hook_xreq *hook;
 452
 453         /* scan hook list to get the expected flags */
 454         flags = 0;
 455         pthread_rwlock_rdlock(&rwlock);
 456         hook = list_of_xreq_hooks;
 457         while (hook) {
 458                 f = hook->flags & afb_hook_flags_req_all;
 459                 add = f != 0
 460                    && (!hook->session || hook->session == xreq->context.session)
 461                    && (!hook->api || !strcasecmp(hook->api, xreq->api))
 462                    && (!hook->verb || !strcasecmp(hook->verb, xreq->verb));
 463                 if (add)
 464                         flags |= f;
 465                 hook = hook->next;
 466         }
 467         pthread_rwlock_unlock(&rwlock);
 468
 469         /* store the hooking data */
 470         xreq->hookflags = flags;
 471         if (flags) {
 472                 pthread_rwlock_wrlock(&rwlock);
 473                 if (++reqindex < 0)
 474                         reqindex = 1;
 475                 xreq->hookindex = reqindex;
 476                 pthread_rwlock_unlock(&rwlock);
 477         }
 478 }
 479
 480 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)
 481 {
 482         struct afb_hook_xreq *hook;
 483
 484         /* alloc the result */
 485         hook = calloc(1, sizeof *hook);
 486         if (hook == NULL)
 487                 return NULL;
 488
 489         /* get a copy of the names */
 490         hook->api = api ? strdup(api) : NULL;
 491         hook->verb = verb ? strdup(verb) : NULL;
 492         if ((api && !hook->api) || (verb && !hook->verb)) {
 493                 free(hook->api);
 494                 free(hook->verb);
 495                 free(hook);
 496                 return NULL;
 497         }
 498
 499         /* initialise the rest */
 500         hook->session = session;
 501         if (session)
 502                 afb_session_addref(session);
 503         hook->refcount = 1;
 504         hook->flags = flags;
 505         hook->itf = itf ? itf : &hook_xreq_default_itf;
 506         hook->closure = closure;
 507
 508         /* record the hook */
 509         pthread_rwlock_wrlock(&rwlock);
 510         hook->next = list_of_xreq_hooks;
 511         list_of_xreq_hooks = hook;
 512         pthread_rwlock_unlock(&rwlock);
 513
 514         /* returns it */
 515         return hook;
 516 }
 517
 518 struct afb_hook_xreq *afb_hook_addref_xreq(struct afb_hook_xreq *hook)
 519 {
 520         pthread_rwlock_wrlock(&rwlock);
 521         hook->refcount++;
 522         pthread_rwlock_unlock(&rwlock);
 523         return hook;
 524 }
 525
 526 void afb_hook_unref_xreq(struct afb_hook_xreq *hook)
 527 {
 528         struct afb_hook_xreq **prv;
 529
 530         if (hook) {
 531                 pthread_rwlock_wrlock(&rwlock);
 532                 if (--hook->refcount)
 533                         hook = NULL;
 534                 else {
 535                         /* unlink */
 536                         prv = &list_of_xreq_hooks;
 537                         while (*prv && *prv != hook)
 538                                 prv = &(*prv)->next;
 539                         if(*prv)
 540                                 *prv = hook->next;
 541                 }
 542                 pthread_rwlock_unlock(&rwlock);
 543                 if (hook) {
 544                         /* free */
 545                         free(hook->api);
 546                         free(hook->verb);
 547                         if (hook->session)
 548                                 afb_session_unref(hook->session);
 549                         free(hook);
 550                 }
 551         }
 552 }
 553
 554 /******************************************************************************
 555  * section: default callbacks for tracing daemon interface
 556  *****************************************************************************/
 557
 558 static void _hook_ditf_(const struct afb_ditf *ditf, const char *format, ...)
 559 {
 560         va_list ap;
 561         va_start(ap, format);
 562         _hook_("ditf-%s", format, ap, ditf->api);
 563         va_end(ap);
 564 }
 565
 566 static void hook_ditf_event_broadcast_before_cb(void *closure, const struct afb_ditf *ditf, const char *name, struct json_object *object)
 567 {
 568         _hook_ditf_(ditf, "event_broadcast.before(%s, %s)....", name, json_object_to_json_string(object));
 569 }
 570
 571 static void hook_ditf_event_broadcast_after_cb(void *closure, const struct afb_ditf *ditf, const char *name, struct json_object *object, int result)
 572 {
 573         _hook_ditf_(ditf, "event_broadcast.after(%s, %s) -> %d", name, json_object_to_json_string(object), result);
 574 }
 575
 576 static void hook_ditf_get_event_loop_cb(void *closure, const struct afb_ditf *ditf, struct sd_event *result)
 577 {
 578         _hook_ditf_(ditf, "get_event_loop() -> %p", result);
 579 }
 580
 581 static void hook_ditf_get_user_bus_cb(void *closure, const struct afb_ditf *ditf, struct sd_bus *result)
 582 {
 583         _hook_ditf_(ditf, "get_user_bus() -> %p", result);
 584 }
 585
 586 static void hook_ditf_get_system_bus_cb(void *closure, const struct afb_ditf *ditf, struct sd_bus *result)
 587 {
 588         _hook_ditf_(ditf, "get_system_bus() -> %p", result);
 589 }
 590
 591 static void hook_ditf_vverbose_cb(void*closure, const struct afb_ditf *ditf, int level, const char *file, int line, const char *function, const char *fmt, va_list args)
 592 {
 593         int len;
 594         char *msg;
 595         va_list ap;
 596
 597         va_copy(ap, args);
 598         len = vasprintf(&msg, fmt, ap);
 599         va_end(ap);
 600
 601         if (len < 0)
 602                 _hook_ditf_(ditf, "vverbose(%d, %s, %d, %s) -> %s ? ? ?", level, file, line, function, fmt);
 603         else {
 604                 _hook_ditf_(ditf, "vverbose(%d, %s, %d, %s) -> %s", level, file, line, function, msg);
 605                 free(msg);
 606         }
 607 }
 608
 609 static void hook_ditf_event_make_cb(void *closure, const struct afb_ditf *ditf, const char *name, struct afb_event result)
 610 {
 611         _hook_ditf_(ditf, "event_make(%s) -> %s:%d", name, afb_evt_event_name(result), afb_evt_event_id(result));
 612 }
 613
 614 static void hook_ditf_rootdir_get_fd_cb(void *closure, const struct afb_ditf *ditf, int result)
 615 {
 616         char path[PATH_MAX];
 617         if (result < 0)
 618                 _hook_ditf_(ditf, "rootdir_get_fd() -> %d, %m", result);
 619         else {
 620                 sprintf(path, "/proc/self/fd/%d", result);
 621                 readlink(path, path, sizeof path);
 622                 _hook_ditf_(ditf, "rootdir_get_fd() -> %d = %s", result, path);
 623         }
 624 }
 625
 626 static void hook_ditf_rootdir_open_locale_cb(void *closure, const struct afb_ditf *ditf, const char *filename, int flags, const char *locale, int result)
 627 {
 628         char path[PATH_MAX];
 629         if (!locale)
 630                 locale = "(null)";
 631         if (result < 0)
 632                 _hook_ditf_(ditf, "rootdir_open_locale(%s, %d, %s) -> %d, %m", filename, flags, locale, result);
 633         else {
 634                 sprintf(path, "/proc/self/fd/%d", result);
 635                 readlink(path, path, sizeof path);
 636                 _hook_ditf_(ditf, "rootdir_open_locale(%s, %d, %s) -> %d = %s", filename, flags, locale, result, path);
 637         }
 638 }
 639
 640 static void hook_ditf_queue_job_cb(void *closure, const struct afb_ditf *ditf, void (*callback)(int signum, void *arg), void *argument, void *group, int timeout, int result)
 641 {
 642         _hook_ditf_(ditf, "queue_job(%p, %p, %p, %d) -> %d", callback, argument, group, timeout, result);
 643 }
 644
 645 static void hook_ditf_unstore_req_cb(void * closure,  const struct afb_ditf *ditf, struct afb_stored_req *sreq)
 646 {
 647         _hook_ditf_(ditf, "unstore_req(%p)", sreq);
 648 }
 649
 650 static void hook_ditf_require_api_cb(void *closure, const struct afb_ditf *ditf, const char *name, int initialized)
 651 {
 652         _hook_ditf_(ditf, "require_api(%s, %d)...", name, initialized);
 653 }
 654
 655 static void hook_ditf_require_api_result_cb(void *closure, const struct afb_ditf *ditf, const char *name, int initialized, int result)
 656 {
 657         _hook_ditf_(ditf, "...require_api(%s, %d) -> %d", name, initialized, result);
 658 }
 659
 660 static struct afb_hook_ditf_itf hook_ditf_default_itf = {
 661         .hook_ditf_event_broadcast_before = hook_ditf_event_broadcast_before_cb,
 662         .hook_ditf_event_broadcast_after = hook_ditf_event_broadcast_after_cb,
 663         .hook_ditf_get_event_loop = hook_ditf_get_event_loop_cb,
 664         .hook_ditf_get_user_bus = hook_ditf_get_user_bus_cb,
 665         .hook_ditf_get_system_bus = hook_ditf_get_system_bus_cb,
 666         .hook_ditf_vverbose = hook_ditf_vverbose_cb,
 667         .hook_ditf_event_make = hook_ditf_event_make_cb,
 668         .hook_ditf_rootdir_get_fd = hook_ditf_rootdir_get_fd_cb,
 669         .hook_ditf_rootdir_open_locale = hook_ditf_rootdir_open_locale_cb,
 670         .hook_ditf_queue_job = hook_ditf_queue_job_cb,
 671         .hook_ditf_unstore_req = hook_ditf_unstore_req_cb,
 672         .hook_ditf_require_api = hook_ditf_require_api_cb,
 673         .hook_ditf_require_api_result = hook_ditf_require_api_result_cb
 674 };
 675
 676 /******************************************************************************
 677  * section: hooks for tracing daemon interface (ditf)
 678  *****************************************************************************/
 679
 680 #define _HOOK_DITF_(what,...)   \
 681         struct afb_hook_ditf *hook; \
 682         pthread_rwlock_rdlock(&rwlock); \
 683         hook = list_of_ditf_hooks; \
 684         while (hook) { \
 685                 if (hook->itf->hook_ditf_##what \
 686                  && (hook->flags & afb_hook_flag_ditf_##what) != 0 \
 687                  && (!hook->api || !strcasecmp(hook->api, ditf->api))) { \
 688                         hook->itf->hook_ditf_##what(hook->closure, __VA_ARGS__); \
 689                 } \
 690                 hook = hook->next; \
 691         } \
 692         pthread_rwlock_unlock(&rwlock);
 693
 694 void afb_hook_ditf_event_broadcast_before(const struct afb_ditf *ditf, const char *name, struct json_object *object)
 695 {
 696         _HOOK_DITF_(event_broadcast_before, ditf, name, object);
 697 }
 698
 699 int afb_hook_ditf_event_broadcast_after(const struct afb_ditf *ditf, const char *name, struct json_object *object, int result)
 700 {
 701         _HOOK_DITF_(event_broadcast_after, ditf, name, object, result);
 702         return result;
 703 }
 704
 705 struct sd_event *afb_hook_ditf_get_event_loop(const struct afb_ditf *ditf, struct sd_event *result)
 706 {
 707         _HOOK_DITF_(get_event_loop, ditf, result);
 708         return result;
 709 }
 710
 711 struct sd_bus *afb_hook_ditf_get_user_bus(const struct afb_ditf *ditf, struct sd_bus *result)
 712 {
 713         _HOOK_DITF_(get_user_bus, ditf, result);
 714         return result;
 715 }
 716
 717 struct sd_bus *afb_hook_ditf_get_system_bus(const struct afb_ditf *ditf, struct sd_bus *result)
 718 {
 719         _HOOK_DITF_(get_system_bus, ditf, result);
 720         return result;
 721 }
 722
 723 void afb_hook_ditf_vverbose(const struct afb_ditf *ditf, int level, const char *file, int line, const char *function, const char *fmt, va_list args)
 724 {
 725         _HOOK_DITF_(vverbose, ditf, level, file, line, function, fmt, args);
 726 }
 727
 728 struct afb_event afb_hook_ditf_event_make(const struct afb_ditf *ditf, const char *name, struct afb_event result)
 729 {
 730         _HOOK_DITF_(event_make, ditf, name, result);
 731         return result;
 732 }
 733
 734 int afb_hook_ditf_rootdir_get_fd(const struct afb_ditf *ditf, int result)
 735 {
 736         _HOOK_DITF_(rootdir_get_fd, ditf, result);
 737         return result;
 738 }
 739
 740 int afb_hook_ditf_rootdir_open_locale(const struct afb_ditf *ditf, const char *filename, int flags, const char *locale, int result)
 741 {
 742         _HOOK_DITF_(rootdir_open_locale, ditf, filename, flags, locale, result);
 743         return result;
 744 }
 745
 746 int afb_hook_ditf_queue_job(const struct afb_ditf *ditf, void (*callback)(int signum, void *arg), void *argument, void *group, int timeout, int result)
 747 {
 748         _HOOK_DITF_(queue_job, ditf, callback, argument, group, timeout, result);
 749         return result;
 750 }
 751
 752 void afb_hook_ditf_unstore_req(const struct afb_ditf *ditf, struct afb_stored_req *sreq)
 753 {
 754         _HOOK_DITF_(unstore_req, ditf, sreq);
 755 }
 756
 757 void afb_hook_ditf_require_api(const struct afb_ditf *ditf, const char *name, int initialized)
 758 {
 759         _HOOK_DITF_(require_api, ditf, name, initialized);
 760 }
 761
 762 int afb_hook_ditf_require_api_result(const struct afb_ditf *ditf, const char *name, int initialized, int result)
 763 {
 764         _HOOK_DITF_(require_api_result, ditf, name, initialized, result);
 765         return result;
 766 }
 767
 768 /******************************************************************************
 769  * section: hooking ditf
 770  *****************************************************************************/
 771
 772 int afb_hook_flags_ditf(const char *api)
 773 {
 774         int flags;
 775         struct afb_hook_ditf *hook;
 776
 777         pthread_rwlock_rdlock(&rwlock);
 778         flags = 0;
 779         hook = list_of_ditf_hooks;
 780         while (hook) {
 781                 if (!api || !hook->api || !strcasecmp(hook->api, api))
 782                         flags |= hook->flags;
 783                 hook = hook->next;
 784         }
 785         pthread_rwlock_unlock(&rwlock);
 786         return flags;
 787 }
 788
 789 struct afb_hook_ditf *afb_hook_create_ditf(const char *api, int flags, struct afb_hook_ditf_itf *itf, void *closure)
 790 {
 791         struct afb_hook_ditf *hook;
 792
 793         /* alloc the result */
 794         hook = calloc(1, sizeof *hook);
 795         if (hook == NULL)
 796                 return NULL;
 797
 798         /* get a copy of the names */
 799         hook->api = api ? strdup(api) : NULL;
 800         if (api && !hook->api) {
 801                 free(hook);
 802                 return NULL;
 803         }
 804
 805         /* initialise the rest */
 806         hook->refcount = 1;
 807         hook->flags = flags;
 808         hook->itf = itf ? itf : &hook_ditf_default_itf;
 809         hook->closure = closure;
 810
 811         /* record the hook */
 812         pthread_rwlock_wrlock(&rwlock);
 813         hook->next = list_of_ditf_hooks;
 814         list_of_ditf_hooks = hook;
 815         pthread_rwlock_unlock(&rwlock);
 816
 817         /* returns it */
 818         return hook;
 819 }
 820
 821 struct afb_hook_ditf *afb_hook_addref_ditf(struct afb_hook_ditf *hook)
 822 {
 823         pthread_rwlock_wrlock(&rwlock);
 824         hook->refcount++;
 825         pthread_rwlock_unlock(&rwlock);
 826         return hook;
 827 }
 828
 829 void afb_hook_unref_ditf(struct afb_hook_ditf *hook)
 830 {
 831         struct afb_hook_ditf **prv;
 832
 833         if (hook) {
 834                 pthread_rwlock_wrlock(&rwlock);
 835                 if (--hook->refcount)
 836                         hook = NULL;
 837                 else {
 838                         /* unlink */
 839                         prv = &list_of_ditf_hooks;
 840                         while (*prv && *prv != hook)
 841                                 prv = &(*prv)->next;
 842                         if(*prv)
 843                                 *prv = hook->next;
 844                 }
 845                 pthread_rwlock_unlock(&rwlock);
 846                 if (hook) {
 847                         /* free */
 848                         free(hook->api);
 849                         free(hook);
 850                 }
 851         }
 852 }
 853
 854 /******************************************************************************
 855  * section: default callbacks for tracing service interface (svc)
 856  *****************************************************************************/
 857
 858 static void _hook_svc_(const struct afb_svc *svc, const char *format, ...)
 859 {
 860         va_list ap;
 861         va_start(ap, format);
 862         _hook_("svc-%s", format, ap, svc->api);
 863         va_end(ap);
 864 }
 865
 866 static void hook_svc_start_before_default_cb(void *closure, const struct afb_svc *svc)
 867 {
 868         _hook_svc_(svc, "start.before");
 869 }
 870
 871 static void hook_svc_start_after_default_cb(void *closure, const struct afb_svc *svc, int status)
 872 {
 873         _hook_svc_(svc, "start.after -> %d", status);
 874 }
 875
 876 static void hook_svc_on_event_before_default_cb(void *closure, const struct afb_svc *svc, const char *event, int eventid, struct json_object *object)
 877 {
 878         _hook_svc_(svc, "on_event.before(%s, %d, %s)", event, eventid, json_object_to_json_string(object));
 879 }
 880
 881 static void hook_svc_on_event_after_default_cb(void *closure, const struct afb_svc *svc, const char *event, int eventid, struct json_object *object)
 882 {
 883         _hook_svc_(svc, "on_event.after(%s, %d, %s)", event, eventid, json_object_to_json_string(object));
 884 }
 885
 886 static void hook_svc_call_default_cb(void *closure, const struct afb_svc *svc, const char *api, const char *verb, struct json_object *args)
 887 {
 888         _hook_svc_(svc, "call(%s/%s, %s) ...", api, verb, json_object_to_json_string(args));
 889 }
 890
 891 static void hook_svc_call_result_default_cb(void *closure, const struct afb_svc *svc, int status, struct json_object *result)
 892 {
 893         _hook_svc_(svc, "    ...call... -> %d: %s", status, json_object_to_json_string(result));
 894 }
 895
 896 static void hook_svc_callsync_default_cb(void *closure, const struct afb_svc *svc, const char *api, const char *verb, struct json_object *args)
 897 {
 898         _hook_svc_(svc, "callsync(%s/%s, %s) ...", api, verb, json_object_to_json_string(args));
 899 }
 900
 901 static void hook_svc_callsync_result_default_cb(void *closure, const struct afb_svc *svc, int status, struct json_object *result)
 902 {
 903         _hook_svc_(svc, "    ...callsync... -> %d: %s", status, json_object_to_json_string(result));
 904 }
 905
 906 static struct afb_hook_svc_itf hook_svc_default_itf = {
 907         .hook_svc_start_before = hook_svc_start_before_default_cb,
 908         .hook_svc_start_after = hook_svc_start_after_default_cb,
 909         .hook_svc_on_event_before = hook_svc_on_event_before_default_cb,
 910         .hook_svc_on_event_after = hook_svc_on_event_after_default_cb,
 911         .hook_svc_call = hook_svc_call_default_cb,
 912         .hook_svc_call_result = hook_svc_call_result_default_cb,
 913         .hook_svc_callsync = hook_svc_callsync_default_cb,
 914         .hook_svc_callsync_result = hook_svc_callsync_result_default_cb
 915 };
 916
 917 /******************************************************************************
 918  * section: hooks for tracing service interface (svc)
 919  *****************************************************************************/
 920
 921 #define _HOOK_SVC_(what,...)   \
 922         struct afb_hook_svc *hook; \
 923         pthread_rwlock_rdlock(&rwlock); \
 924         hook = list_of_svc_hooks; \
 925         while (hook) { \
 926                 if (hook->itf->hook_svc_##what \
 927                  && (hook->flags & afb_hook_flag_svc_##what) != 0 \
 928                  && (!hook->api || !strcasecmp(hook->api, svc->api))) { \
 929                         hook->itf->hook_svc_##what(hook->closure, __VA_ARGS__); \
 930                 } \
 931                 hook = hook->next; \
 932         } \
 933         pthread_rwlock_unlock(&rwlock);
 934
 935 void afb_hook_svc_start_before(const struct afb_svc *svc)
 936 {
 937         _HOOK_SVC_(start_before, svc);
 938 }
 939
 940 int afb_hook_svc_start_after(const struct afb_svc *svc, int status)
 941 {
 942         _HOOK_SVC_(start_after, svc, status);
 943         return status;
 944 }
 945
 946 void afb_hook_svc_on_event_before(const struct afb_svc *svc, const char *event, int eventid, struct json_object *object)
 947 {
 948         _HOOK_SVC_(on_event_before, svc, event, eventid, object);
 949 }
 950
 951 void afb_hook_svc_on_event_after(const struct afb_svc *svc, const char *event, int eventid, struct json_object *object)
 952 {
 953         _HOOK_SVC_(on_event_after, svc, event, eventid, object);
 954 }
 955
 956 void afb_hook_svc_call(const struct afb_svc *svc, const char *api, const char *verb, struct json_object *args)
 957 {
 958         _HOOK_SVC_(call, svc, api, verb, args);
 959 }
 960
 961 void afb_hook_svc_call_result(const struct afb_svc *svc, int status, struct json_object *result)
 962 {
 963         _HOOK_SVC_(call_result, svc, status, result);
 964 }
 965
 966 void afb_hook_svc_callsync(const struct afb_svc *svc, const char *api, const char *verb, struct json_object *args)
 967 {
 968         _HOOK_SVC_(callsync, svc, api, verb, args);
 969 }
 970
 971 int afb_hook_svc_callsync_result(const struct afb_svc *svc, int status, struct json_object *result)
 972 {
 973         _HOOK_SVC_(callsync_result, svc, status, result);
 974         return status;
 975 }
 976
 977 /******************************************************************************
 978  * section: hooking services (svc)
 979  *****************************************************************************/
 980
 981 int afb_hook_flags_svc(const char *api)
 982 {
 983         int flags;
 984         struct afb_hook_svc *hook;
 985
 986         pthread_rwlock_rdlock(&rwlock);
 987         flags = 0;
 988         hook = list_of_svc_hooks;
 989         while (hook) {
 990                 if (!api || !hook->api || !strcasecmp(hook->api, api))
 991                         flags |= hook->flags;
 992                 hook = hook->next;
 993         }
 994         pthread_rwlock_unlock(&rwlock);
 995         return flags;
 996 }
 997
 998 struct afb_hook_svc *afb_hook_create_svc(const char *api, int flags, struct afb_hook_svc_itf *itf, void *closure)
 999 {
1000         struct afb_hook_svc *hook;
1001
1002         /* alloc the result */
1003         hook = calloc(1, sizeof *hook);
1004         if (hook == NULL)
1005                 return NULL;
1006
1007         /* get a copy of the names */
1008         hook->api = api ? strdup(api) : NULL;
1009         if (api && !hook->api) {
1010                 free(hook);
1011                 return NULL;
1012         }
1013
1014         /* initialise the rest */
1015         hook->refcount = 1;
1016         hook->flags = flags;
1017         hook->itf = itf ? itf : &hook_svc_default_itf;
1018         hook->closure = closure;
1019
1020         /* record the hook */
1021         pthread_rwlock_wrlock(&rwlock);
1022         hook->next = list_of_svc_hooks;
1023         list_of_svc_hooks = hook;
1024         pthread_rwlock_unlock(&rwlock);
1025
1026         /* returns it */
1027         return hook;
1028 }
1029
1030 struct afb_hook_svc *afb_hook_addref_svc(struct afb_hook_svc *hook)
1031 {
1032         pthread_rwlock_wrlock(&rwlock);
1033         hook->refcount++;
1034         pthread_rwlock_unlock(&rwlock);
1035         return hook;
1036 }
1037
1038 void afb_hook_unref_svc(struct afb_hook_svc *hook)
1039 {
1040         struct afb_hook_svc **prv;
1041
1042         if (hook) {
1043                 pthread_rwlock_wrlock(&rwlock);
1044                 if (--hook->refcount)
1045                         hook = NULL;
1046                 else {
1047                         /* unlink */
1048                         prv = &list_of_svc_hooks;
1049                         while (*prv && *prv != hook)
1050                                 prv = &(*prv)->next;
1051                         if(*prv)
1052                                 *prv = hook->next;
1053                 }
1054                 pthread_rwlock_unlock(&rwlock);
1055                 if (hook) {
1056                         /* free */
1057                         free(hook->api);
1058                         free(hook);
1059                 }
1060         }
1061 }
1062
1063 /******************************************************************************
1064  * section: default callbacks for tracing service interface (evt)
1065  *****************************************************************************/
1066
1067 static void _hook_evt_(const char *evt, int id, const char *format, ...)
1068 {
1069         va_list ap;
1070         va_start(ap, format);
1071         _hook_("evt-%s:%d", format, ap, evt, id);
1072         va_end(ap);
1073 }
1074
1075 static void hook_evt_create_default_cb(void *closure, const char *evt, int id)
1076 {
1077         _hook_evt_(evt, id, "create");
1078 }
1079
1080 static void hook_evt_push_before_default_cb(void *closure, const char *evt, int id, struct json_object *obj)
1081 {
1082         _hook_evt_(evt, id, "push.before(%s)", json_object_to_json_string(obj));
1083 }
1084
1085
1086 static void hook_evt_push_after_default_cb(void *closure, const char *evt, int id, struct json_object *obj, int result)
1087 {
1088         _hook_evt_(evt, id, "push.after(%s) -> %d", json_object_to_json_string(obj), result);
1089 }
1090
1091 static void hook_evt_broadcast_before_default_cb(void *closure, const char *evt, int id, struct json_object *obj)
1092 {
1093         _hook_evt_(evt, id, "broadcast.before(%s)", json_object_to_json_string(obj));
1094 }
1095
1096 static void hook_evt_broadcast_after_default_cb(void *closure, const char *evt, int id, struct json_object *obj, int result)
1097 {
1098         _hook_evt_(evt, id, "broadcast.after(%s) -> %d", json_object_to_json_string(obj), result);
1099 }
1100
1101 static void hook_evt_name_default_cb(void *closure, const char *evt, int id)
1102 {
1103         _hook_evt_(evt, id, "name");
1104 }
1105
1106 static void hook_evt_drop_default_cb(void *closure, const char *evt, int id)
1107 {
1108         _hook_evt_(evt, id, "drop");
1109 }
1110
1111 static struct afb_hook_evt_itf hook_evt_default_itf = {
1112         .hook_evt_create = hook_evt_create_default_cb,
1113         .hook_evt_push_before = hook_evt_push_before_default_cb,
1114         .hook_evt_push_after = hook_evt_push_after_default_cb,
1115         .hook_evt_broadcast_before = hook_evt_broadcast_before_default_cb,
1116         .hook_evt_broadcast_after = hook_evt_broadcast_after_default_cb,
1117         .hook_evt_name = hook_evt_name_default_cb,
1118         .hook_evt_drop = hook_evt_drop_default_cb
1119 };
1120
1121 /******************************************************************************
1122  * section: hooks for tracing service interface (evt)
1123  *****************************************************************************/
1124
1125 #define _HOOK_EVT_(what,...)   \
1126         struct afb_hook_evt *hook; \
1127         pthread_rwlock_rdlock(&rwlock); \
1128         hook = list_of_evt_hooks; \
1129         while (hook) { \
1130                 if (hook->itf->hook_evt_##what \
1131                  && (hook->flags & afb_hook_flag_evt_##what) != 0 \
1132                  && (!hook->pattern || !fnmatch(hook->pattern, evt, FNM_CASEFOLD))) { \
1133                         hook->itf->hook_evt_##what(hook->closure, __VA_ARGS__); \
1134                 } \
1135                 hook = hook->next; \
1136         } \
1137         pthread_rwlock_unlock(&rwlock);
1138
1139 void afb_hook_evt_create(const char *evt, int id)
1140 {
1141         _HOOK_EVT_(create, evt, id);
1142 }
1143
1144 void afb_hook_evt_push_before(const char *evt, int id, struct json_object *obj)
1145 {
1146         _HOOK_EVT_(push_before, evt, id, obj);
1147 }
1148
1149 int afb_hook_evt_push_after(const char *evt, int id, struct json_object *obj, int result)
1150 {
1151         _HOOK_EVT_(push_after, evt, id, obj, result);
1152         return result;
1153 }
1154
1155 void afb_hook_evt_broadcast_before(const char *evt, int id, struct json_object *obj)
1156 {
1157         _HOOK_EVT_(broadcast_before, evt, id, obj);
1158 }
1159
1160 int afb_hook_evt_broadcast_after(const char *evt, int id, struct json_object *obj, int result)
1161 {
1162         _HOOK_EVT_(broadcast_after, evt, id, obj, result);
1163         return result;
1164 }
1165
1166 void afb_hook_evt_name(const char *evt, int id)
1167 {
1168         _HOOK_EVT_(name, evt, id);
1169 }
1170
1171 void afb_hook_evt_drop(const char *evt, int id)
1172 {
1173         _HOOK_EVT_(drop, evt, id);
1174 }
1175
1176 /******************************************************************************
1177  * section: hooking services (evt)
1178  *****************************************************************************/
1179
1180 int afb_hook_flags_evt(const char *name)
1181 {
1182         int flags;
1183         struct afb_hook_evt *hook;
1184
1185         pthread_rwlock_rdlock(&rwlock);
1186         flags = 0;
1187         hook = list_of_evt_hooks;
1188         while (hook) {
1189                 if (!name || !hook->pattern || !fnmatch(hook->pattern, name, FNM_CASEFOLD))
1190                         flags |= hook->flags;
1191                 hook = hook->next;
1192         }
1193         pthread_rwlock_unlock(&rwlock);
1194         return flags;
1195 }
1196
1197 struct afb_hook_evt *afb_hook_create_evt(const char *pattern, int flags, struct afb_hook_evt_itf *itf, void *closure)
1198 {
1199         struct afb_hook_evt *hook;
1200
1201         /* alloc the result */
1202         hook = calloc(1, sizeof *hook);
1203         if (hook == NULL)
1204                 return NULL;
1205
1206         /* get a copy of the names */
1207         hook->pattern = pattern ? strdup(pattern) : NULL;
1208         if (pattern && !hook->pattern) {
1209                 free(hook);
1210                 return NULL;
1211         }
1212
1213         /* initialise the rest */
1214         hook->refcount = 1;
1215         hook->flags = flags;
1216         hook->itf = itf ? itf : &hook_evt_default_itf;
1217         hook->closure = closure;
1218
1219         /* record the hook */
1220         pthread_rwlock_wrlock(&rwlock);
1221         hook->next = list_of_evt_hooks;
1222         list_of_evt_hooks = hook;
1223         pthread_rwlock_unlock(&rwlock);
1224
1225         /* returns it */
1226         return hook;
1227 }
1228
1229 struct afb_hook_evt *afb_hook_addref_evt(struct afb_hook_evt *hook)
1230 {
1231         pthread_rwlock_wrlock(&rwlock);
1232         hook->refcount++;
1233         pthread_rwlock_unlock(&rwlock);
1234         return hook;
1235 }
1236
1237 void afb_hook_unref_evt(struct afb_hook_evt *hook)
1238 {
1239         struct afb_hook_evt **prv;
1240
1241         if (hook) {
1242                 pthread_rwlock_wrlock(&rwlock);
1243                 if (--hook->refcount)
1244                         hook = NULL;
1245                 else {
1246                         /* unlink */
1247                         prv = &list_of_evt_hooks;
1248                         while (*prv && *prv != hook)
1249                                 prv = &(*prv)->next;
1250                         if(*prv)
1251                                 *prv = hook->next;
1252                 }
1253                 pthread_rwlock_unlock(&rwlock);
1254                 if (hook) {
1255                         /* free */
1256                         free(hook->pattern);
1257                         free(hook);
1258                 }
1259         }
1260 }