ustd/ustd.c

   1 /* Copyright (C) 2009  Pierre-Marc Fournier
   2  *
   3  * This library is free software; you can redistribute it and/or
   4  * modify it under the terms of the GNU Lesser General Public
   5  * License as published by the Free Software Foundation; either
   6  * version 2.1 of the License, or (at your option) any later version.
   7  *
   8  * This library is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * Lesser General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU Lesser General Public
  14  * License along with this library; if not, write to the Free Software
  15  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
  16  */
  17
  18 #define _GNU_SOURCE
  19
  20 #include <sys/types.h>
  21 #include <sys/stat.h>
  22 #include <sys/shm.h>
  23 #include <fcntl.h>
  24 #include <unistd.h>
  25 #include <pthread.h>
  26 #include <signal.h>
  27
  28 #include <stdlib.h>
  29 #include <stdio.h>
  30 #include <string.h>
  31 #include <errno.h>
  32 #include <assert.h>
  33 #include <getopt.h>
  34
  35 #include "ustd.h"
  36 #include "localerr.h"
  37 #include "ustcomm.h"
  38
  39 /* return value: 0 = subbuffer is finished, it won't produce data anymore
  40  *               1 = got subbuffer successfully
  41  *               <0 = error
  42  */
  43
  44 #define GET_SUBBUF_OK 1
  45 #define GET_SUBBUF_DONE 0
  46 #define GET_SUBBUF_DIED 2
  47
  48 #define PUT_SUBBUF_OK 1
  49 #define PUT_SUBBUF_DIED 0
  50 #define PUT_SUBBUF_PUSHED 2
  51
  52 char *sock_path=NULL;
  53 char *trace_path=NULL;
  54
  55 /* Number of active buffers and the mutex to protect it. */
  56 int active_buffers = 0;
  57 pthread_mutex_t active_buffers_mutex = PTHREAD_MUTEX_INITIALIZER;
  58 /* Whether a request to end the program was received. */
  59 sig_atomic_t terminate_req = 0;
  60
  61 int test_sigpipe(void)
  62 {
  63         sigset_t sigset;
  64         int result;
  65
  66         result = sigemptyset(&sigset);
  67         if(result == -1) {
  68                 PERROR("sigemptyset");
  69                 return -1;
  70         }
  71         result = sigaddset(&sigset, SIGPIPE);
  72         if(result == -1) {
  73                 PERROR("sigaddset");
  74                 return -1;
  75         }
  76
  77         result = sigtimedwait(&sigset, NULL, &(struct timespec){0,0});
  78         if(result == -1 && errno == EAGAIN) {
  79                 /* no signal received */
  80                 return 0;
  81         }
  82         else if(result == -1) {
  83                 PERROR("sigtimedwait");
  84                 return -1;
  85         }
  86         else if(result == SIGPIPE) {
  87                 /* received sigpipe */
  88                 return 1;
  89         }
  90         else {
  91                 assert(0);
  92         }
  93 }
  94
  95 int get_subbuffer(struct buffer_info *buf)
  96 {
  97         char *send_msg=NULL;
  98         char *received_msg=NULL;
  99         char *rep_code=NULL;
 100         int retval;
 101         int result;
 102
 103         asprintf(&send_msg, "get_subbuffer %s", buf->name);
 104         result = ustcomm_send_request(&buf->conn, send_msg, &received_msg);
 105         if(test_sigpipe()) {
 106                 WARN("process %d destroyed before we could connect to it", buf->pid);
 107                 retval = GET_SUBBUF_DONE;
 108                 goto end;
 109         }
 110         else if(result < 0) {
 111                 ERR("get_subbuffer: ustcomm_send_request failed");
 112                 retval = -1;
 113                 goto end;
 114         }
 115         else if(result == 0) {
 116                 DBG("app died while being traced");
 117                 retval = GET_SUBBUF_DIED;
 118                 goto end;
 119         }
 120
 121         result = sscanf(received_msg, "%as %ld", &rep_code, &buf->consumed_old);
 122         if(result != 2 && result != 1) {
 123                 ERR("unable to parse response to get_subbuffer");
 124                 retval = -1;
 125                 goto end_rep;
 126         }
 127
 128         DBG("received msg is %s", received_msg);
 129
 130         if(!strcmp(rep_code, "OK")) {
 131                 DBG("got subbuffer %s", buf->name);
 132                 retval = GET_SUBBUF_OK;
 133         }
 134         else if(nth_token_is(received_msg, "END", 0) == 1) {
 135                 retval = GET_SUBBUF_DONE;
 136                 goto end_rep;
 137         }
 138         else {
 139                 DBG("error getting subbuffer %s", buf->name);
 140                 retval = -1;
 141         }
 142
 143         /* FIMXE: free correctly the stuff */
 144 end_rep:
 145         if(rep_code)
 146                 free(rep_code);
 147 end:
 148         if(send_msg)
 149                 free(send_msg);
 150         if(received_msg)
 151                 free(received_msg);
 152
 153         return retval;
 154 }
 155
 156 int put_subbuffer(struct buffer_info *buf)
 157 {
 158         char *send_msg=NULL;
 159         char *received_msg=NULL;
 160         char *rep_code=NULL;
 161         int retval;
 162         int result;
 163
 164         asprintf(&send_msg, "put_subbuffer %s %ld", buf->name, buf->consumed_old);
 165         result = ustcomm_send_request(&buf->conn, send_msg, &received_msg);
 166         if(result < 0 && errno == ECONNRESET) {
 167                 retval = PUT_SUBBUF_DIED;
 168                 goto end;
 169         }
 170         if(result < 0) {
 171                 ERR("put_subbuffer: send_message failed");
 172                 retval = -1;
 173                 goto end;
 174         }
 175
 176         result = sscanf(received_msg, "%as", &rep_code);
 177         if(result != 1) {
 178                 ERR("unable to parse response to put_subbuffer");
 179                 retval = -1;
 180                 goto end_rep;
 181         }
 182
 183         if(!strcmp(rep_code, "OK")) {
 184                 DBG("subbuffer put %s", buf->name);
 185                 retval = PUT_SUBBUF_OK;
 186         }
 187         else {
 188                 DBG("put_subbuffer: received error, we were pushed");
 189                 retval = PUT_SUBBUF_PUSHED;
 190                 goto end_rep;
 191         }
 192
 193 end_rep:
 194         if(rep_code)
 195                 free(rep_code);
 196
 197 end:
 198         if(send_msg)
 199                 free(send_msg);
 200         if(received_msg)
 201                 free(received_msg);
 202
 203         return retval;
 204 }
 205
 206 /* This write is patient because it restarts if it was incomplete.
 207  */
 208
 209 ssize_t patient_write(int fd, const void *buf, size_t count)
 210 {
 211         const char *bufc = (const char *) buf;
 212         int result;
 213
 214         for(;;) {
 215                 result = write(fd, bufc, count);
 216                 if(result <= 0) {
 217                         return result;
 218                 }
 219                 count -= result;
 220                 bufc += result;
 221
 222                 if(count == 0) {
 223                         break;
 224                 }
 225         }
 226
 227         return bufc-(const char *)buf;
 228 }
 229
 230 void decrement_active_buffers(void *arg)
 231 {
 232         pthread_mutex_lock(&active_buffers_mutex);
 233         active_buffers--;
 234         pthread_mutex_unlock(&active_buffers_mutex);
 235 }
 236
 237 void *consumer_thread(void *arg)
 238 {
 239         struct buffer_info *buf = (struct buffer_info *) arg;
 240         int result;
 241
 242         pthread_cleanup_push(decrement_active_buffers, NULL);
 243
 244         for(;;) {
 245                 /* get the subbuffer */
 246                 result = get_subbuffer(buf);
 247                 if(result == -1) {
 248                         ERR("error getting subbuffer");
 249                         continue;
 250                 }
 251                 else if(result == GET_SUBBUF_DONE) {
 252                         /* this is done */
 253                         break;
 254                 }
 255                 else if(result == GET_SUBBUF_DIED) {
 256                         finish_consuming_dead_subbuffer(buf);
 257                         break;
 258                 }
 259
 260                 /* write data to file */
 261                 result = patient_write(buf->file_fd, buf->mem + (buf->consumed_old & (buf->n_subbufs * buf->subbuf_size-1)), buf->subbuf_size);
 262                 if(result == -1) {
 263                         PERROR("write");
 264                         /* FIXME: maybe drop this trace */
 265                 }
 266
 267                 /* put the subbuffer */
 268                 result = put_subbuffer(buf);
 269                 if(result == -1) {
 270                         ERR("unknown error putting subbuffer (channel=%s)", buf->name);
 271                         break;
 272                 }
 273                 else if(result == PUT_SUBBUF_PUSHED) {
 274                         ERR("Buffer overflow (channel=%s), reader pushed. This channel will not be usable passed this point.", buf->name);
 275                         break;
 276                 }
 277                 else if(result == PUT_SUBBUF_DIED) {
 278                         WARN("application died while putting subbuffer");
 279                         /* FIXME: probably need to skip the first subbuffer in finish_consuming_dead_subbuffer */
 280                         finish_consuming_dead_subbuffer(buf);
 281                         break;
 282                 }
 283                 else if(result == PUT_SUBBUF_OK) {
 284                 }
 285         }
 286
 287         DBG("thread for buffer %s is stopping", buf->name);
 288
 289         /* FIXME: destroy, unalloc... */
 290
 291         pthread_cleanup_pop(1);
 292
 293         return NULL;
 294 }
 295
 296 int create_dir_if_needed(char *dir)
 297 {
 298         int result;
 299         result = mkdir(dir, 0777);
 300         if(result == -1) {
 301                 if(errno != EEXIST) {
 302                         PERROR("mkdir");
 303                         return -1;
 304                 }
 305         }
 306
 307         return 0;
 308 }
 309
 310 int is_directory(const char *dir)
 311 {
 312         int result;
 313         struct stat st;
 314
 315         result = stat(dir, &st);
 316         if(result == -1) {
 317                 PERROR("stat");
 318                 return 0;
 319         }
 320
 321         if(!S_ISDIR(st.st_mode)) {
 322                 return 0;
 323         }
 324
 325         return 1;
 326 }
 327
 328 int add_buffer(pid_t pid, char *bufname)
 329 {
 330         struct buffer_info *buf;
 331         char *send_msg;
 332         char *received_msg;
 333         int result;
 334         char *tmp;
 335         int fd;
 336         pthread_t thr;
 337         struct shmid_ds shmds;
 338
 339         buf = (struct buffer_info *) malloc(sizeof(struct buffer_info));
 340         if(buf == NULL) {
 341                 ERR("add_buffer: insufficient memory");
 342                 return -1;
 343         }
 344
 345         buf->name = bufname;
 346         buf->pid = pid;
 347
 348         /* connect to app */
 349         result = ustcomm_connect_app(buf->pid, &buf->conn);
 350         if(result) {
 351                 WARN("unable to connect to process, it probably died before we were able to connect");
 352                 return -1;
 353         }
 354
 355         /* get pidunique */
 356         asprintf(&send_msg, "get_pidunique");
 357         result = ustcomm_send_request(&buf->conn, send_msg, &received_msg);
 358         free(send_msg);
 359         if(result == -1) {
 360                 ERR("problem in ustcomm_send_request(get_pidunique)");
 361                 return -1;
 362         }
 363
 364         result = sscanf(received_msg, "%lld", &buf->pidunique);
 365         if(result != 1) {
 366                 ERR("unable to parse response to get_pidunique");
 367                 return -1;
 368         }
 369         free(received_msg);
 370         DBG("got pidunique %lld", buf->pidunique);
 371
 372         /* get shmid */
 373         asprintf(&send_msg, "get_shmid %s", buf->name);
 374         result = ustcomm_send_request(&buf->conn, send_msg, &received_msg);
 375         free(send_msg);
 376         if(result == -1) {
 377                 ERR("problem in ustcomm_send_request(get_shmid)");
 378                 return -1;
 379         }
 380
 381         result = sscanf(received_msg, "%d %d", &buf->shmid, &buf->bufstruct_shmid);
 382         if(result != 2) {
 383                 ERR("unable to parse response to get_shmid");
 384                 return -1;
 385         }
 386         free(received_msg);
 387         DBG("got shmids %d %d", buf->shmid, buf->bufstruct_shmid);
 388
 389         /* get n_subbufs */
 390         asprintf(&send_msg, "get_n_subbufs %s", buf->name);
 391         result = ustcomm_send_request(&buf->conn, send_msg, &received_msg);
 392         free(send_msg);
 393         if(result == -1) {
 394                 ERR("problem in ustcomm_send_request(g_n_subbufs)");
 395                 return -1;
 396         }
 397
 398         result = sscanf(received_msg, "%d", &buf->n_subbufs);
 399         if(result != 1) {
 400                 ERR("unable to parse response to get_n_subbufs");
 401                 return -1;
 402         }
 403         free(received_msg);
 404         DBG("got n_subbufs %d", buf->n_subbufs);
 405
 406         /* get subbuf size */
 407         asprintf(&send_msg, "get_subbuf_size %s", buf->name);
 408         ustcomm_send_request(&buf->conn, send_msg, &received_msg);
 409         free(send_msg);
 410
 411         result = sscanf(received_msg, "%d", &buf->subbuf_size);
 412         if(result != 1) {
 413                 ERR("unable to parse response to get_subbuf_size");
 414                 return -1;
 415         }
 416         free(received_msg);
 417         DBG("got subbuf_size %d", buf->subbuf_size);
 418
 419         /* attach memory */
 420         buf->mem = shmat(buf->shmid, NULL, 0);
 421         if(buf->mem == (void *) 0) {
 422                 PERROR("shmat");
 423                 return -1;
 424         }
 425         DBG("successfully attached buffer memory");
 426
 427         buf->bufstruct_mem = shmat(buf->bufstruct_shmid, NULL, 0);
 428         if(buf->bufstruct_mem == (void *) 0) {
 429                 PERROR("shmat");
 430                 return -1;
 431         }
 432         DBG("successfully attached buffer bufstruct memory");
 433
 434         /* obtain info on the memory segment */
 435         result = shmctl(buf->shmid, IPC_STAT, &shmds);
 436         if(result == -1) {
 437                 PERROR("shmctl");
 438                 return -1;
 439         }
 440         buf->memlen = shmds.shm_segsz;
 441
 442         /* open file for output */
 443         if(!trace_path) {
 444                 /* Only create the directory if using the default path, because
 445                  * of the risk of typo when using trace path override. We don't
 446                  * want to risk creating plenty of useless directories in that case.
 447                  */
 448                 result = create_dir_if_needed(USTD_DEFAULT_TRACE_PATH);
 449                 if(result == -1) {
 450                         ERR("could not create directory %s", USTD_DEFAULT_TRACE_PATH);
 451                         return -1;
 452                 }
 453
 454                 trace_path = USTD_DEFAULT_TRACE_PATH;
 455         }
 456
 457         asprintf(&tmp, "%s/%u_%lld", trace_path, buf->pid, buf->pidunique);
 458         result = create_dir_if_needed(tmp);
 459         if(result == -1) {
 460                 ERR("could not create directory %s", tmp);
 461                 free(tmp);
 462                 return -1;
 463         }
 464         free(tmp);
 465
 466         asprintf(&tmp, "%s/%u_%lld/%s_0", trace_path, buf->pid, buf->pidunique, buf->name);
 467         result = fd = open(tmp, O_WRONLY | O_CREAT | O_TRUNC | O_EXCL, 00600);
 468         if(result == -1) {
 469                 PERROR("open");
 470                 ERR("failed opening trace file %s", tmp);
 471                 return -1;
 472         }
 473         buf->file_fd = fd;
 474         free(tmp);
 475
 476         pthread_mutex_lock(&active_buffers_mutex);
 477         active_buffers++;
 478         pthread_mutex_unlock(&active_buffers_mutex);
 479
 480         pthread_create(&thr, NULL, consumer_thread, buf);
 481
 482         return 0;
 483 }
 484
 485 void usage(void)
 486 {
 487         fprintf(stderr, "Usage:\nustd OPTIONS\n\nOptions:\n"
 488                         "\t-h\t\tDisplay this usage.\n"
 489                         "\t-o DIR\t\tSpecify the directory where to output the traces.\n"
 490                         "\t-s PATH\t\tSpecify the path to use for the daemon socket.\n");
 491 }
 492
 493 int parse_args(int argc, char **argv)
 494 {
 495         int c;
 496
 497         while (1) {
 498                 int option_index = 0;
 499                 static struct option long_options[] = {
 500                         {"help", 0, 0, 'h'},
 501                         {"version", 0, 0, 'V'},
 502                         {0, 0, 0, 0}
 503                 };
 504
 505                 c = getopt_long(argc, argv, "hs:o:", long_options, &option_index);
 506                 if (c == -1)
 507                         break;
 508
 509                 switch (c) {
 510                 case 0:
 511                         printf("option %s", long_options[option_index].name);
 512                         if (optarg)
 513                                 printf(" with arg %s", optarg);
 514                         printf("\n");
 515                         break;
 516                 case 's':
 517                         sock_path = optarg;
 518                         break;
 519                 case 'o':
 520                         trace_path = optarg;
 521                         if(!is_directory(trace_path)) {
 522                                 ERR("Not a valid directory. (%s)", trace_path);
 523                                 return -1;
 524                         }
 525                         break;
 526                 case 'h':
 527                         usage();
 528                         exit(0);
 529                 case 'V':
 530                         printf("Version 0.0\n");
 531                         break;
 532
 533                 default:
 534                         /* unknown option or other error; error is
 535                         printed by getopt, just return */
 536                         return -1;
 537                 }
 538         }
 539
 540         return 0;
 541 }
 542
 543 void sigterm_handler(int sig)
 544 {
 545         terminate_req = 1;
 546 }
 547
 548 int main(int argc, char **argv)
 549 {
 550         struct ustcomm_ustd ustd;
 551         int result;
 552         sigset_t sigset;
 553         struct sigaction sa;
 554
 555         result = sigemptyset(&sigset);
 556         if(result == -1) {
 557                 PERROR("sigemptyset");
 558                 return 1;
 559         }
 560         sa.sa_handler = sigterm_handler;
 561         sa.sa_mask = sigset;
 562         sa.sa_flags = SA_RESTART;
 563         result = sigaction(SIGTERM, &sa, NULL);
 564         if(result == -1) {
 565                 PERROR("sigaction");
 566                 return 1;
 567         }
 568
 569         result = parse_args(argc, argv);
 570         if(result == -1) {
 571                 exit(1);
 572         }
 573
 574         result = ustcomm_init_ustd(&ustd, sock_path);
 575         if(result == -1) {
 576                 ERR("failed to initialize socket");
 577                 return 1;
 578         }
 579
 580         /* setup handler for SIGPIPE */
 581         result = sigemptyset(&sigset);
 582         if(result == -1) {
 583                 PERROR("sigemptyset");
 584                 return 1;
 585         }
 586         result = sigaddset(&sigset, SIGPIPE);
 587         if(result == -1) {
 588                 PERROR("sigaddset");
 589                 return 1;
 590         }
 591         result = sigprocmask(SIG_BLOCK, &sigset, NULL);
 592         if(result == -1) {
 593                 PERROR("sigprocmask");
 594                 return 1;
 595         }
 596
 597         /* app loop */
 598         for(;;) {
 599                 char *recvbuf;
 600
 601                 /* check for requests on our public socket */
 602                 result = ustcomm_ustd_recv_message(&ustd, &recvbuf, NULL, 100);
 603                 if(result == -1) {
 604                         ERR("error in ustcomm_ustd_recv_message");
 605                         continue;
 606                 }
 607                 if(result > 0) {
 608                         if(!strncmp(recvbuf, "collect", 7)) {
 609                                 pid_t pid;
 610                                 char *bufname;
 611                                 int result;
 612
 613                                 result = sscanf(recvbuf, "%*s %d %50as", &pid, &bufname);
 614                                 if(result != 2) {
 615                                         fprintf(stderr, "parsing error: %s\n", recvbuf);
 616                                 }
 617
 618                                 result = add_buffer(pid, bufname);
 619                                 if(result < 0) {
 620                                         ERR("error in add_buffer");
 621                                         continue;
 622                                 }
 623                         }
 624
 625                         free(recvbuf);
 626                 }
 627
 628                 if(terminate_req) {
 629                         pthread_mutex_lock(&active_buffers_mutex);
 630                         if(active_buffers == 0) {
 631                                 pthread_mutex_unlock(&active_buffers_mutex);
 632                                 break;
 633                         }
 634                         pthread_mutex_unlock(&active_buffers_mutex);
 635                 }
 636         }
 637
 638         return 0;
 639 }