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