tests/ust-multi-test/ust-multi-test.c

   1 /*
   2  * ust-multi-test.c - single-proces, multi-session, multi-channel, multi-event UST tracing
   3  *
   4  * Copyright (C) 2011 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   5  * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; version 2 of the License only.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along
  17  * with this program; if not, write to the Free Software Foundation, Inc.,
  18  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  19  */
  20
  21 #define _LARGEFILE64_SOURCE
  22 #define _GNU_SOURCE
  23 #include <errno.h>
  24 #include <stdio.h>
  25 #include <stdlib.h>
  26 #include <string.h>
  27 #include <signal.h>
  28 #include <unistd.h>
  29 #include <sys/wait.h>
  30 #include <sys/types.h>
  31 #include <sys/time.h>
  32 #include <sys/resource.h>
  33 #include <sys/stat.h>
  34 #include <fcntl.h>
  35 #include <sys/mman.h>
  36 #include <limits.h>
  37 #include <urcu/futex.h>
  38 #include <urcu/uatomic.h>
  39 #include <assert.h>
  40 #include <sys/socket.h>
  41
  42 #include <ust-comm.h>
  43 #include <lttng/ust-error.h>
  44 #include <../../libringbuffer/backend.h>
  45 #include <../../libringbuffer/frontend.h>
  46 #include "../../liblttng-ust/compat.h"  /* For ENODATA */
  47
  48 #define NR_SESSIONS     4
  49 #define NR_CHANNELS     1
  50 #define MAX_NR_STREAMS  64
  51 #define NR_EVENTS       3
  52
  53 const char *evname[] = {
  54         "ust_tests_hello_tptest",
  55         "ust_tests_hello_tptest_sighandler",
  56         "ust_tests_hello_dontexist",
  57 };
  58
  59 static int session_handle[NR_SESSIONS];
  60 static struct lttng_ust_object_data metadata_stream_data[NR_SESSIONS];
  61 static struct lttng_ust_object_data metadata_data[NR_SESSIONS];
  62 static struct lttng_ust_object_data channel_data[NR_SESSIONS][NR_CHANNELS];
  63 static struct lttng_ust_object_data stream_data[NR_SESSIONS][NR_CHANNELS][MAX_NR_STREAMS];
  64 static int event_handle[NR_SESSIONS][NR_CHANNELS][NR_EVENTS];
  65
  66 static int apps_socket = -1;
  67 static char apps_sock_path[PATH_MAX];
  68 static char local_apps_wait_shm_path[PATH_MAX];
  69
  70 static volatile int quit_program;
  71
  72 static void handle_signals(int signo)
  73 {
  74         quit_program = 1;
  75 }
  76
  77 static
  78 int open_streams(int sock, int channel_handle, struct lttng_ust_object_data *stream_datas,
  79                 int nr_check)
  80 {
  81         int ret, k = 0;
  82
  83         for (;;) {
  84                 struct ustcomm_ust_msg lum;
  85                 struct ustcomm_ust_reply lur;
  86
  87                 memset(&lum, 0, sizeof(lum));
  88                 lum.handle = channel_handle;
  89                 lum.cmd = LTTNG_UST_STREAM;
  90                 ret = ustcomm_send_app_cmd(sock, &lum, &lur);
  91                 if (!ret) {
  92                         assert(k < nr_check);
  93                         stream_datas[k].handle = lur.ret_val;
  94                         printf("received stream handle %u\n",
  95                                 stream_datas[k].handle);
  96                         if (lur.ret_code == LTTNG_UST_OK) {
  97                                 ssize_t len;
  98
  99                                 stream_datas[k].memory_map_size = lur.u.stream.memory_map_size;
 100                                 /* get shm fd */
 101                                 len = ustcomm_recv_fd(sock);
 102                                 if (len < 0)
 103                                         return -EINVAL;
 104                                 stream_datas[k].shm_fd = len;
 105                                 /* get wait fd */
 106                                 len = ustcomm_recv_fd(sock);
 107                                 if (len < 0)
 108                                         return -EINVAL;
 109                                 stream_datas[k].wait_fd = len;
 110                         }
 111                         k++;
 112                 }
 113                 if (ret == -LTTNG_UST_ERR_NOENT)
 114                         break;
 115                 if (ret)
 116                         return ret;
 117         }
 118         return 0;
 119 }
 120
 121 static
 122 int close_streams(int sock, struct lttng_ust_object_data *stream_datas, int nr_check)
 123 {
 124         int ret, k;
 125
 126         for (k = 0; k < nr_check; k++) {
 127                 struct ustcomm_ust_msg lum;
 128                 struct ustcomm_ust_reply lur;
 129
 130                 if (!stream_datas[k].handle)
 131                         continue;
 132                 memset(&lum, 0, sizeof(lum));
 133                 lum.handle = stream_datas[k].handle;
 134                 lum.cmd = LTTNG_UST_RELEASE;
 135                 ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 136                 if (ret) {
 137                         printf("Error closing stream\n");
 138                         return ret;
 139                 }
 140                 if (stream_datas[k].shm_fd >= 0) {
 141                         ret = close(stream_datas[k].shm_fd);
 142                         if (ret) {
 143                                 printf("Error closing stream shm_fd\n");
 144                                 return ret;
 145                         }
 146                 }
 147                 if (stream_datas[k].wait_fd >= 0) {
 148                         ret = close(stream_datas[k].wait_fd);
 149                         if (ret) {
 150                                 printf("Error closing stream wait_fd\n");
 151                                 return ret;
 152                         }
 153                 }
 154         }
 155         return 0;
 156 }
 157
 158 static
 159 struct lttng_ust_shm_handle *map_channel(struct lttng_ust_object_data *chan_data,
 160                 struct lttng_ust_object_data *stream_datas, int nr_check)
 161 {
 162         struct lttng_ust_shm_handle *handle;
 163         struct channel *chan;
 164         int k, ret;
 165
 166         /* map metadata channel */
 167         handle = channel_handle_create(chan_data->shm_fd,
 168                 chan_data->wait_fd,
 169                 chan_data->memory_map_size);
 170         if (!handle) {
 171                 printf("create handle error\n");
 172                 return NULL;
 173         }
 174         chan_data->shm_fd = -1;
 175         chan_data->wait_fd = -1;
 176         chan = shmp(handle, handle->chan);
 177
 178         for (k = 0; k < nr_check; k++) {
 179                 struct lttng_ust_object_data *stream_data = &stream_datas[k];
 180
 181                 if (!stream_data->handle)
 182                         break;
 183                 /* map stream */
 184                 ret = channel_handle_add_stream(handle,
 185                         stream_data->shm_fd,
 186                         stream_data->wait_fd,
 187                         stream_data->memory_map_size);
 188                 if (ret) {
 189                         printf("add stream error\n");
 190                         goto error_destroy;
 191                 }
 192                 stream_data->shm_fd = -1;
 193                 stream_data->wait_fd = -1;
 194         }
 195         return handle;
 196
 197 error_destroy:
 198         channel_destroy(chan, handle, 1);
 199         return NULL;
 200 }
 201
 202 static
 203 void unmap_channel(struct lttng_ust_shm_handle *handle)
 204 {
 205         struct channel *chan;
 206
 207         chan = shmp(handle, handle->chan);
 208         /* unmap channel */
 209         channel_destroy(chan, handle, 1);
 210 }
 211
 212 static
 213 int consume_stream(struct lttng_ust_shm_handle *handle, int cpu, char *outfile)
 214 {
 215         struct channel *chan;
 216         struct lttng_ust_lib_ring_buffer *buf;
 217         int outfd, ret;
 218         int *shm_fd, *wait_fd;
 219         uint64_t *memory_map_size;
 220
 221         chan = shmp(handle, handle->chan);
 222
 223         /* open stream */
 224         buf = channel_get_ring_buffer(&chan->backend.config,
 225                 chan, cpu, handle, &shm_fd, &wait_fd, &memory_map_size);
 226         if (!buf)
 227                 return -ENOENT;
 228         ret = lib_ring_buffer_open_read(buf, handle, 1);
 229         if (ret) {
 230                 return -1;
 231         }
 232
 233         /* copy */
 234         outfd = open(outfile, O_WRONLY | O_CREAT | O_TRUNC,
 235                         S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
 236         if (outfd < 0) {
 237                 perror("open output");
 238                 return -1;
 239         }
 240
 241         printf("Waiting for buffer data for %s\n", outfile);
 242         for (;;) {
 243                 unsigned long read_size;
 244                 unsigned long copy_size;
 245                 char *ptr;
 246
 247                 ret = lib_ring_buffer_get_next_subbuf(buf, handle);
 248                 printf("get next ret %d\n", ret);
 249                 if (ret == -ENODATA)
 250                         break;
 251                 if (ret == -EAGAIN) {
 252                         sleep(1);
 253                         continue;
 254                 }
 255                 if (ret) {
 256                         printf("Error %d in lib_ring_buffer_get_next_subbuf\n", ret);
 257                         return -1;
 258                 }
 259                 read_size = lib_ring_buffer_get_read_data_size(
 260                         &chan->backend.config, buf, handle);
 261                 read_size = PAGE_ALIGN(read_size);
 262                 ptr = lib_ring_buffer_read_offset_address(
 263                         &buf->backend, 0, handle);
 264                 printf("WRITE: copy %lu bytes\n", read_size);
 265                 copy_size = write(outfd, ptr, read_size);
 266                 if (copy_size < read_size) {
 267                         printf("write issue: copied %lu, expected %lu\n", copy_size, read_size);
 268                 }
 269                 lib_ring_buffer_put_next_subbuf(buf, handle);
 270         }
 271
 272         ret = close(outfd);
 273         if (ret) {
 274                 perror("close");
 275                 return -1;
 276         }
 277
 278         /* close stream */
 279         lib_ring_buffer_release_read(buf, handle, 1);
 280         return 0;
 281 }
 282
 283 static
 284 int consume_buffers(void)
 285 {
 286         int i, j, k, ret;
 287         mode_t old_umask;
 288
 289         for (i = 0; i < NR_SESSIONS; i++) {
 290                 char pathname[PATH_MAX];
 291                 struct lttng_ust_shm_handle *handle;
 292
 293                 snprintf(pathname, PATH_MAX - 1, "/tmp/testtrace%u", i);
 294                 old_umask = umask(0);
 295                 ret = mkdir(pathname, S_IRWXU | S_IRWXG);
 296                 if (ret && errno != EEXIST) {
 297                         perror("mkdir");
 298                         umask(old_umask);
 299                         return -1;
 300                 }
 301                 umask(old_umask);
 302
 303                 /* copy metadata */
 304                 handle = map_channel(&metadata_data[i],
 305                                 &metadata_stream_data[i], 1);
 306                 if (!handle)
 307                         return -1;
 308                 snprintf(pathname, PATH_MAX - 1,
 309                         "/tmp/testtrace%u/metadata", i);
 310                 ret = consume_stream(handle, -1, pathname);
 311                 if (ret && ret != -ENOENT) {
 312                         printf("Error in consume_stream\n");
 313                         return ret;
 314                 }
 315                 unmap_channel(handle);
 316
 317                 /* copy binary data */
 318                 for (j = 0; j < NR_CHANNELS; j++) {
 319                         handle = map_channel(&channel_data[i][j],
 320                                         stream_data[i][j], MAX_NR_STREAMS);
 321                         if (!handle)
 322                                 return -1;
 323                         for (k = 0; k < MAX_NR_STREAMS; k++) {
 324                                 snprintf(pathname, PATH_MAX - 1,
 325                                         "/tmp/testtrace%u/data_%u", i, k);
 326                                 ret = consume_stream(handle, k, pathname);
 327                                 if (ret && ret != -ENOENT) {
 328                                         printf("Error in consume_stream\n");
 329                                         return ret;
 330                                 }
 331                         }
 332                         unmap_channel(handle);
 333                 }
 334         }
 335
 336         return 0;
 337 }
 338
 339 int send_app_msgs(int sock)
 340 {
 341         struct ustcomm_ust_msg lum;
 342         struct ustcomm_ust_reply lur;
 343         int ret, i, j, k;
 344
 345         for (i = 0; i < NR_SESSIONS; i++) {
 346                 /* Create session */
 347                 memset(&lum, 0, sizeof(lum));
 348                 lum.handle = LTTNG_UST_ROOT_HANDLE;
 349                 lum.cmd = LTTNG_UST_SESSION;
 350                 ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 351                 if (ret)
 352                         return ret;
 353                 session_handle[i] = lur.ret_val;
 354                 printf("received session handle %u\n", session_handle[i]);
 355
 356                 /* Create metadata channel */
 357                 memset(&lum, 0, sizeof(lum));
 358                 lum.handle = session_handle[i];
 359                 lum.cmd = LTTNG_UST_METADATA;
 360                 lum.u.channel.overwrite = 0;
 361                 lum.u.channel.subbuf_size = 32768;
 362                 lum.u.channel.num_subbuf = 4;
 363                 lum.u.channel.switch_timer_interval = 0;
 364                 lum.u.channel.read_timer_interval = 0;
 365                 lum.u.channel.output = LTTNG_UST_MMAP;
 366                 ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 367                 if (ret)
 368                         return ret;
 369                 metadata_data[i].handle = lur.ret_val;
 370                 printf("received metadata handle %u\n", metadata_data[i].handle);
 371                 if (lur.ret_code == LTTNG_UST_OK) {
 372                         ssize_t len;
 373
 374                         metadata_data[i].memory_map_size = lur.u.channel.memory_map_size;
 375                         /* get shm fd */
 376                         len = ustcomm_recv_fd(sock);
 377                         if (len < 0)
 378                                 return -EINVAL;
 379                         metadata_data[i].shm_fd = len;
 380                         /* get wait fd */
 381                         len = ustcomm_recv_fd(sock);
 382                         if (len < 0)
 383                                 return -EINVAL;
 384                         metadata_data[i].wait_fd = len;
 385                 }
 386
 387                 ret = open_streams(sock, metadata_data[i].handle,
 388                                 &metadata_stream_data[i], 1);
 389                 if (ret) {
 390                         printf("Error in open_streams\n");
 391                         return ret;
 392                 }
 393
 394                 /* Create channels */
 395                 for (j = 0; j < NR_CHANNELS; j++) {
 396                         memset(&lum, 0, sizeof(lum));
 397                         lum.handle = session_handle[i];
 398                         lum.cmd = LTTNG_UST_CHANNEL;
 399                         //lum.u.channel.overwrite = 0;
 400                         lum.u.channel.overwrite = 1;
 401                         lum.u.channel.subbuf_size = 32768;
 402                         lum.u.channel.num_subbuf = 8;
 403                         //lum.u.channel.num_subbuf = 4;
 404                         //lum.u.channel.num_subbuf = 2;
 405                         lum.u.channel.switch_timer_interval = 0;
 406                         lum.u.channel.read_timer_interval = 0;
 407                         lum.u.channel.output = LTTNG_UST_MMAP;
 408                         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 409                         if (ret)
 410                                 return ret;
 411                         channel_data[i][j].handle = lur.ret_val;
 412                         printf("received channel handle %u\n", channel_data[i][j].handle);
 413                         if (lur.ret_code == LTTNG_UST_OK) {
 414                                 ssize_t len;
 415
 416                                 channel_data[i][j].memory_map_size = lur.u.channel.memory_map_size;
 417                                 /* get shm fd */
 418                                 len = ustcomm_recv_fd(sock);
 419                                 if (len < 0)
 420                                         return -EINVAL;
 421                                 channel_data[i][j].shm_fd = len;
 422                                 /* get wait fd */
 423                                 len = ustcomm_recv_fd(sock);
 424                                 if (len < 0)
 425                                         return -EINVAL;
 426                                 channel_data[i][j].wait_fd = len;
 427                         }
 428
 429                         /* Create events */
 430                         for (k = 0; k < NR_EVENTS; k++) {
 431                                 memset(&lum, 0, sizeof(lum));
 432                                 lum.handle = channel_data[i][j].handle;
 433                                 lum.cmd = LTTNG_UST_EVENT;
 434                                 strncpy(lum.u.event.name, evname[k],
 435                                         LTTNG_UST_SYM_NAME_LEN);
 436                                 lum.u.event.instrumentation = LTTNG_UST_TRACEPOINT;
 437                                 ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 438                                 if (ret)
 439                                         return ret;
 440                                 event_handle[i][j][k] = lur.ret_val;
 441                                 printf("received event handle %u\n", event_handle[i][j][k]);
 442                         }
 443
 444                         /* Get references to channel streams */
 445                         ret = open_streams(sock, channel_data[i][j].handle,
 446                                         stream_data[i][j], MAX_NR_STREAMS);
 447                         if (ret) {
 448                                 printf("Error in open_streams\n");
 449                                 return ret;
 450                         }
 451                 }
 452
 453                 memset(&lum, 0, sizeof(lum));
 454                 lum.handle = session_handle[i];
 455                 lum.cmd = LTTNG_UST_SESSION_START;
 456                 ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 457                 if (ret)
 458                         return ret;
 459                 printf("Session handle %u started.\n", session_handle[i]);
 460         }
 461
 462         /* Tell application registration is done */
 463         memset(&lum, 0, sizeof(lum));
 464         lum.handle = LTTNG_UST_ROOT_HANDLE;
 465         lum.cmd = LTTNG_UST_REGISTER_DONE;
 466         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 467         if (ret)
 468                 return ret;
 469         printf("Registration done acknowledged.\n");
 470
 471         sleep(4);
 472
 473         ret = consume_buffers();
 474         if (ret) {
 475                 printf("Error in consume_buffers\n");
 476                 return ret;
 477         }
 478
 479         for (i = 0; i < NR_SESSIONS; i++) {
 480                 /* Release channels */
 481                 for (j = 0; j < NR_CHANNELS; j++) {
 482                         /* Release streams */
 483                         ret = close_streams(sock, stream_data[i][j],
 484                                         MAX_NR_STREAMS);
 485                         if (ret)
 486                                 return ret;
 487
 488                         /* Release events */
 489                         for (k = 0; k < NR_EVENTS; k++) {
 490                                 memset(&lum, 0, sizeof(lum));
 491                                 lum.handle = event_handle[i][j][k];
 492                                 lum.cmd = LTTNG_UST_RELEASE;
 493                                 ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 494                                 if (ret)
 495                                         return ret;
 496                         }
 497                         memset(&lum, 0, sizeof(lum));
 498                         lum.handle = channel_data[i][j].handle;
 499                         lum.cmd = LTTNG_UST_RELEASE;
 500                         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 501                         if (ret)
 502                                 return ret;
 503                         if (channel_data[i][j].shm_fd >= 0) {
 504                                 ret = close(channel_data[i][j].shm_fd);
 505                                 if (ret)
 506                                         return ret;
 507                         }
 508                         if (channel_data[i][j].wait_fd >= 0) {
 509                                 ret = close(channel_data[i][j].wait_fd);
 510                                 if (ret)
 511                                         return ret;
 512                         }
 513                 }
 514
 515                 /* Release metadata channel */
 516                 ret = close_streams(sock, &metadata_stream_data[i], 1);
 517                 if (ret)
 518                         return ret;
 519
 520                 memset(&lum, 0, sizeof(lum));
 521                 lum.handle = metadata_data[i].handle;
 522                 lum.cmd = LTTNG_UST_RELEASE;
 523                 ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 524                 if (ret)
 525                         return ret;
 526                 if (metadata_data[i].shm_fd >= 0) {
 527                         ret = close(metadata_data[i].shm_fd);
 528                         if (ret)
 529                                 return ret;
 530                 }
 531                 if (metadata_data[i].wait_fd >= 0) {
 532                         ret = close(metadata_data[i].wait_fd);
 533                         if (ret)
 534                                 return ret;
 535                 }
 536
 537                 /* Release session */
 538                 memset(&lum, 0, sizeof(lum));
 539                 lum.handle = session_handle[i];
 540                 lum.cmd = LTTNG_UST_RELEASE;
 541                 ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 542                 if (ret)
 543                         return ret;
 544         }
 545
 546         return 0;
 547 }
 548
 549 /*
 550  * Using fork to set umask in the child process (not multi-thread safe). We
 551  * deal with the shm_open vs ftruncate race (happening when the sessiond owns
 552  * the shm and does not let everybody modify it, to ensure safety against
 553  * shm_unlink) by simply letting the mmap fail and retrying after a few
 554  * seconds. For global shm, everybody has rw access to it until the sessiond
 555  * starts.
 556  */
 557 static int get_wait_shm(char *shm_path, size_t mmap_size, int global)
 558 {
 559         int wait_shm_fd, ret;
 560         mode_t mode;
 561
 562         /* Default permissions */
 563         mode = S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP;
 564
 565         /* Change owner of the shm path */
 566         if (global) {
 567                 ret = chown(shm_path, 0, 0);
 568                 if (ret < 0) {
 569                         if (errno != ENOENT) {
 570                                 perror("chown wait shm");
 571                                 goto error;
 572                         }
 573                 }
 574
 575                 /*
 576                  * If global session daemon, any application can register so the shm
 577                  * needs to be set in read-only mode for others.
 578                  */
 579                 mode |= S_IROTH;
 580         } else {
 581                 ret = chown(shm_path, getuid(), getgid());
 582                 if (ret < 0) {
 583                         if (errno != ENOENT) {
 584                                 perror("chown wait shm");
 585                                 goto error;
 586                         }
 587                 }
 588         }
 589
 590         /*
 591          * Set permissions to the shm even if we did not create the shm.
 592          */
 593         ret = chmod(shm_path, mode);
 594         if (ret < 0) {
 595                 if (errno != ENOENT) {
 596                         perror("chmod wait shm");
 597                         goto error;
 598                 }
 599         }
 600
 601         /*
 602          * We're alone in a child process, so we can modify the process-wide
 603          * umask.
 604          */
 605         umask(~mode);
 606
 607         /*
 608          * Try creating shm (or get rw access). We don't do an exclusive open,
 609          * because we allow other processes to create+ftruncate it concurrently.
 610          */
 611         wait_shm_fd = shm_open(shm_path, O_RDWR | O_CREAT, mode);
 612         if (wait_shm_fd < 0) {
 613                 perror("shm_open wait shm");
 614                 goto error;
 615         }
 616
 617         ret = ftruncate(wait_shm_fd, mmap_size);
 618         if (ret < 0) {
 619                 perror("ftruncate wait shm");
 620                 exit(EXIT_FAILURE);
 621         }
 622
 623         ret = fchmod(wait_shm_fd, mode);
 624         if (ret < 0) {
 625                 perror("fchmod");
 626                 exit(EXIT_FAILURE);
 627         }
 628
 629         printf("Got the wait shm fd %d\n", wait_shm_fd);
 630
 631         return wait_shm_fd;
 632
 633 error:
 634         printf("Failing to get the wait shm fd\n");
 635
 636         return -1;
 637 }
 638
 639 int update_futex(int fd, int active)
 640 {
 641         long page_size;
 642         char *wait_shm_mmap;
 643         int ret;
 644
 645         page_size = sysconf(_SC_PAGE_SIZE);
 646         if (page_size < 0) {
 647                 goto error;
 648         }
 649         wait_shm_mmap = mmap(NULL, page_size, PROT_READ | PROT_WRITE,
 650                   MAP_SHARED, fd, 0);
 651         if (wait_shm_mmap == MAP_FAILED) {
 652                 perror("mmap");
 653                 goto error;
 654         }
 655
 656         if (active) {
 657                 uatomic_set((int32_t *) wait_shm_mmap, 1);
 658                 futex_async((int32_t *) wait_shm_mmap, FUTEX_WAKE,
 659                                 INT_MAX, NULL, NULL, 0);
 660         } else {
 661                 uatomic_set((int32_t *) wait_shm_mmap, 0);
 662         }
 663         ret = munmap(wait_shm_mmap, page_size);
 664         if (ret) {
 665                 perror("Error unmapping wait shm");
 666                 goto error;
 667         }
 668         return 0;
 669 error:
 670         return -1;
 671 }
 672
 673 /*
 674  * Set open files limit to unlimited. This daemon can open a large number of
 675  * file descriptors in order to consumer multiple kernel traces.
 676  */
 677 static void set_ulimit(void)
 678 {
 679         int ret;
 680         struct rlimit lim;
 681
 682         /*
 683          * If not root, we cannot increase our max open files. But our
 684          * scope is then limited to processes from a single user.
 685          */
 686         if (getuid() != 0)
 687                 return;
 688         /* The kernel does not allowed an infinite limit for open files */
 689         lim.rlim_cur = 65535;
 690         lim.rlim_max = 65535;
 691
 692         ret = setrlimit(RLIMIT_NOFILE, &lim);
 693         if (ret < 0) {
 694                 perror("failed to set open files limit");
 695         }
 696 }
 697
 698 int main(int argc, char **argv)
 699 {
 700         const char *home_dir;
 701         char home_rundir[PATH_MAX];
 702         char *cmd = NULL;
 703         int ret, wait_shm_fd;
 704         struct sigaction act;
 705         mode_t old_umask = 0;
 706
 707         set_ulimit();
 708
 709         /* Ignore sigpipe */
 710         memset(&act, 0, sizeof(act));
 711         ret = sigemptyset(&act.sa_mask);
 712         if (ret == -1) {
 713                 perror("sigemptyset");
 714                 return -1;
 715         }
 716
 717         act.sa_handler = SIG_IGN;
 718         ret = sigaction(SIGPIPE, &act, NULL);
 719         if (ret == -1) {
 720                 perror("sigaction");
 721                 return -1;
 722         }
 723
 724         /* Handle SIGTERM */
 725         act.sa_handler = handle_signals;
 726         ret = sigaction(SIGTERM, &act, NULL);
 727         if (ret == -1) {
 728                 perror("sigaction");
 729                 return -1;
 730         }
 731         /* Handle SIGINT */
 732         ret = sigaction(SIGINT, &act, NULL);
 733         if (ret == -1) {
 734                 perror("sigaction");
 735                 return -1;
 736         }
 737
 738         if (geteuid() == 0) {
 739                 ret = mkdir(LTTNG_RUNDIR, S_IRWXU | S_IRWXG | S_IROTH | S_IXOTH);
 740                 if (ret && errno != EEXIST) {
 741                         perror("mkdir");
 742                         return -1;
 743                 }
 744                 wait_shm_fd = get_wait_shm(DEFAULT_GLOBAL_APPS_WAIT_SHM_PATH,
 745                                         sysconf(_SC_PAGE_SIZE), 1);
 746                 if (wait_shm_fd < 0) {
 747                         perror("global wait shm error");
 748                         return -1;
 749                 }
 750                 strcpy(apps_sock_path, DEFAULT_GLOBAL_APPS_UNIX_SOCK);
 751                 old_umask = umask(0);
 752         } else {
 753                 home_dir = (const char *) getenv("HOME");
 754                 if (!home_dir) {
 755                         perror("getenv error");
 756                         return -ENOENT;
 757                 }
 758
 759                 snprintf(home_rundir, PATH_MAX,
 760                          LTTNG_HOME_RUNDIR, home_dir);
 761
 762                 ret = mkdir(home_rundir, S_IRWXU | S_IRWXG | S_IROTH | S_IXOTH);
 763                 if (ret && errno != EEXIST) {
 764                         perror("mkdir");
 765                         return -1;
 766                 }
 767
 768                 snprintf(local_apps_wait_shm_path, PATH_MAX,
 769                          DEFAULT_HOME_APPS_WAIT_SHM_PATH, getuid());
 770                 wait_shm_fd = get_wait_shm(local_apps_wait_shm_path,
 771                                         sysconf(_SC_PAGE_SIZE), 0);
 772                 if (wait_shm_fd < 0) {
 773                         perror("local wait shm error");
 774                         return -1;
 775                 }
 776                 snprintf(apps_sock_path, PATH_MAX,
 777                          DEFAULT_HOME_APPS_UNIX_SOCK, home_dir);
 778         }
 779
 780         ret = ustcomm_create_unix_sock(apps_sock_path);
 781         if (ret < 0) {
 782                 perror("create error");
 783                 return ret;
 784         }
 785         apps_socket = ret;
 786
 787         if (getuid() == 0) {
 788                 /* File permission MUST be 666 */
 789                 ret = chmod(apps_sock_path,
 790                                 S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH);
 791                 if (ret < 0) {
 792                         printf("Set file permissions failed: %s\n", apps_sock_path);
 793                         perror("chmod");
 794                         goto end;
 795                 }
 796                 umask(old_umask);
 797         }
 798         ret = ustcomm_listen_unix_sock(apps_socket);
 799         if (ret < 0) {
 800                 perror("listen error");
 801                 return ret;
 802         }
 803
 804         /* wake up futexes */
 805         ret = update_futex(wait_shm_fd, 1);
 806         if (ret) {
 807                 fprintf(stderr, "Error wakeup futex\n");
 808                 return -1;
 809         }
 810
 811         for (;;) {
 812                 int sock;
 813                 ssize_t len;
 814                 struct {
 815                         uint32_t major;
 816                         uint32_t minor;
 817                         pid_t pid;
 818                         pid_t ppid;
 819                         uid_t uid;
 820                         gid_t gid;
 821                         uint32_t bits_per_long;
 822                         char name[16];  /* Process name */
 823                 } reg_msg;
 824                 char bufname[17];
 825
 826                 if (quit_program)
 827                         break;
 828
 829                 printf("Accepting application registration\n");
 830                 sock = ustcomm_accept_unix_sock(apps_socket);
 831                 if (sock < 0) {
 832                         perror("accept error");
 833                         goto end;
 834                 }
 835
 836                 /*
 837                  * Basic recv here to handle the very simple data
 838                  * that the libust send to register (reg_msg).
 839                  */
 840                 len = ustcomm_recv_unix_sock(sock, &reg_msg, sizeof(reg_msg));
 841                 if (len < 0 || len != sizeof(reg_msg)) {
 842                         perror("ustcomm_recv_unix_sock");
 843                         continue;
 844                 }
 845                 memcpy(bufname, reg_msg.name, 16);
 846                 bufname[16] = '\0';
 847                 printf("Application %s pid %u ppid %u uid %u gid %u has registered (version : %u.%u)\n",
 848                         bufname, reg_msg.pid, reg_msg.ppid, reg_msg.uid,
 849                         reg_msg.gid, reg_msg.major, reg_msg.minor);
 850                 ret = send_app_msgs(sock);
 851                 if (ret) {
 852                         printf("Error in send_app_msgs.\n");
 853                         sleep(1);
 854                 }
 855                 close(sock);
 856         }
 857
 858 end:
 859         printf("quitting.\n");
 860         /* Let applications know we are not responding anymore */
 861         ret = update_futex(wait_shm_fd, 0);
 862         if (ret) {
 863                 fprintf(stderr, "Error wakeup futex\n");
 864                 return -1;
 865         }
 866
 867         if (geteuid()) {
 868                 printf("Removing %s directory\n", home_rundir);
 869                 ret = asprintf(&cmd, "rm -rf %s", home_rundir);
 870                 if (ret < 0) {
 871                         printf("asprintf failed. Something is really wrong!\n");
 872                         return -1;
 873                 }
 874
 875                 /* Remove lttng run directory */
 876                 ret = system(cmd);
 877                 if (ret < 0) {
 878                         printf("Unable to clean %s\n", home_rundir);
 879                         return -1;
 880                 }
 881         }
 882
 883         return 0;
 884 }