ustd/ustd.c

   1 /* Copyright (C) 2009  Pierre-Marc Fournier
   2  *               2010  Alexis Halle
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2.1 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with this library; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
  17  */
  18
  19 #define _GNU_SOURCE
  20
  21 #include <sys/types.h>
  22 #include <sys/stat.h>
  23 #include <sys/shm.h>
  24 #include <fcntl.h>
  25 #include <unistd.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 "ust/ustd.h"
  36 #include "usterr.h"
  37
  38 char *sock_path=NULL;
  39 char *trace_path=NULL;
  40 int daemon_mode = 0;
  41 char *pidfile = NULL;
  42
  43 struct libustd_instance *instance;
  44
  45 struct buffer_info_local {
  46         /* output file */
  47         int file_fd;
  48         /* the offset we must truncate to, to unput the last subbuffer */
  49         off_t previous_offset;
  50 };
  51
  52 static int write_pidfile(const char *file_name, pid_t pid)
  53 {
  54         FILE *pidfp;
  55
  56         pidfp = fopen(file_name, "w");
  57         if(!pidfp) {
  58                 PERROR("fopen (%s)", file_name);
  59                 WARN("killing child process");
  60                 return -1;
  61         }
  62
  63         fprintf(pidfp, "%d\n", pid);
  64
  65         fclose(pidfp);
  66
  67         return 0;
  68 }
  69
  70 int create_dir_if_needed(char *dir)
  71 {
  72         int result;
  73         result = mkdir(dir, 0777);
  74         if(result == -1) {
  75                 if(errno != EEXIST) {
  76                         PERROR("mkdir");
  77                         return -1;
  78                 }
  79         }
  80
  81         return 0;
  82 }
  83
  84 int unwrite_last_subbuffer(struct buffer_info *buf)
  85 {
  86         int result;
  87         struct buffer_info_local *buf_local = buf->user_data;
  88
  89         result = ftruncate(buf_local->file_fd, buf_local->previous_offset);
  90         if(result == -1) {
  91                 PERROR("ftruncate");
  92                 return -1;
  93         }
  94
  95         result = lseek(buf_local->file_fd, buf_local->previous_offset, SEEK_SET);
  96         if(result == (int)(off_t)-1) {
  97                 PERROR("lseek");
  98                 return -1;
  99         }
 100
 101         return 0;
 102 }
 103
 104 int write_current_subbuffer(struct buffer_info *buf)
 105 {
 106         int result;
 107         struct buffer_info_local *buf_local = buf->user_data;
 108
 109         void *subbuf_mem = buf->mem + (buf->consumed_old & (buf->n_subbufs * buf->subbuf_size-1));
 110
 111         size_t cur_sb_size = subbuffer_data_size(subbuf_mem);
 112
 113         off_t cur_offset = lseek(buf_local->file_fd, 0, SEEK_CUR);
 114         if(cur_offset == (off_t)-1) {
 115                 PERROR("lseek");
 116                 return -1;
 117         }
 118
 119         buf_local->previous_offset = cur_offset;
 120         DBG("previous_offset: %ld", cur_offset);
 121
 122         result = patient_write(buf_local->file_fd, subbuf_mem, cur_sb_size);
 123         if(result == -1) {
 124                 PERROR("write");
 125                 return -1;
 126         }
 127
 128         return 0;
 129 }
 130
 131 int on_read_subbuffer(struct libustd_callbacks *data, struct buffer_info *buf)
 132 {
 133         return write_current_subbuffer(buf);
 134 }
 135
 136 int on_read_partial_subbuffer(struct libustd_callbacks *data, struct buffer_info *buf,
 137                                 long subbuf_index, unsigned long valid_length)
 138 {
 139         struct buffer_info_local *buf_local = buf->user_data;
 140         char *tmp;
 141         int result;
 142         unsigned long pad_size;
 143
 144         result = patient_write(buf_local->file_fd, buf->mem + subbuf_index * buf->subbuf_size, valid_length);
 145         if(result == -1) {
 146                 ERR("Error writing to buffer file");
 147                 return;
 148         }
 149
 150         /* pad with empty bytes */
 151         pad_size = PAGE_ALIGN(valid_length)-valid_length;
 152         if(pad_size) {
 153                 tmp = zmalloc(pad_size);
 154                 result = patient_write(buf_local->file_fd, tmp, pad_size);
 155                 if(result == -1) {
 156                         ERR("Error writing to buffer file");
 157                         return;
 158                 }
 159                 free(tmp);
 160         }
 161
 162 }
 163
 164 int on_open_buffer(struct libustd_callbacks *data, struct buffer_info *buf)
 165 {
 166         char *tmp;
 167         int result;
 168         int fd;
 169         struct buffer_info_local *buf_local =
 170                 zmalloc(sizeof(struct buffer_info_local));
 171
 172         if(!buf_local) {
 173                 ERR("could not allocate buffer_info_local struct");
 174                 return 1;
 175         }
 176
 177         buf->user_data = buf_local;
 178
 179         /* open file for output */
 180         if(!trace_path) {
 181                 /* Only create the directory if using the default path, because
 182                  * of the risk of typo when using trace path override. We don't
 183                  * want to risk creating plenty of useless directories in that case.
 184                  */
 185                 result = create_dir_if_needed(USTD_DEFAULT_TRACE_PATH);
 186                 if(result == -1) {
 187                         ERR("could not create directory %s", USTD_DEFAULT_TRACE_PATH);
 188                         return 1;
 189                 }
 190
 191                 trace_path = USTD_DEFAULT_TRACE_PATH;
 192         }
 193
 194         if (asprintf(&tmp, "%s/%u_%lld", trace_path, buf->pid, buf->pidunique) < 0) {
 195                 ERR("on_open_buffer : asprintf failed (%s/%u_%lld)",
 196                     trace_path, buf->pid, buf->pidunique);
 197                 return 1;
 198         }
 199         result = create_dir_if_needed(tmp);
 200         if(result == -1) {
 201                 ERR("could not create directory %s", tmp);
 202                 free(tmp);
 203                 return 1;
 204         }
 205         free(tmp);
 206
 207         if (asprintf(&tmp, "%s/%u_%lld/%s", trace_path, buf->pid, buf->pidunique, buf->name) < 0) {
 208                 ERR("on_open_buffer : asprintf failed (%s/%u_%lld/%s)",
 209                     trace_path, buf->pid, buf->pidunique, buf->name);
 210                 return 1;
 211         }
 212         result = fd = open(tmp, O_WRONLY | O_CREAT | O_TRUNC | O_EXCL, 00600);
 213         if(result == -1) {
 214                 PERROR("open");
 215                 ERR("failed opening trace file %s", tmp);
 216                 return 1;
 217         }
 218         buf_local->file_fd = fd;
 219         free(tmp);
 220
 221         return 0;
 222 }
 223
 224 int on_close_buffer(struct libustd_callbacks *data, struct buffer_info *buf)
 225 {
 226         struct buffer_info_local *buf_local = buf->user_data;
 227         int result = close(buf_local->file_fd);
 228         free(buf_local);
 229         if(result == -1) {
 230                 PERROR("close");
 231         }
 232         return 0;
 233 }
 234
 235 int on_put_error(struct libustd_callbacks *data, struct buffer_info *buf)
 236 {
 237         unwrite_last_subbuffer(buf);
 238 }
 239
 240 struct libustd_callbacks *new_callbacks()
 241 {
 242         struct libustd_callbacks *callbacks =
 243                 zmalloc(sizeof(struct libustd_callbacks));
 244
 245         if(!callbacks)
 246                 return NULL;
 247
 248         callbacks->on_open_buffer = on_open_buffer;
 249         callbacks->on_close_buffer = on_close_buffer;
 250         callbacks->on_read_subbuffer = on_read_subbuffer;
 251         callbacks->on_read_partial_subbuffer = on_read_partial_subbuffer;
 252         callbacks->on_put_error = on_put_error;
 253         callbacks->on_new_thread = NULL;
 254         callbacks->on_close_thread = NULL;
 255         callbacks->on_trace_end = NULL;
 256
 257         return callbacks;
 258
 259 }
 260
 261 int is_directory(const char *dir)
 262 {
 263         int result;
 264         struct stat st;
 265
 266         result = stat(dir, &st);
 267         if(result == -1) {
 268                 PERROR("stat");
 269                 return 0;
 270         }
 271
 272         if(!S_ISDIR(st.st_mode)) {
 273                 return 0;
 274         }
 275
 276         return 1;
 277 }
 278
 279 void usage(void)
 280 {
 281         fprintf(stderr, "Usage:\nustd OPTIONS\n\nOptions:\n"
 282                         "\t-h\t\tDisplay this usage.\n"
 283                         "\t-o DIR\t\tSpecify the directory where to output the traces.\n"
 284                         "\t-s PATH\t\tSpecify the path to use for the daemon socket.\n"
 285                         "\t-d\t\tStart as a daemon.\n"
 286                         "\t--pidfile FILE\tWrite the PID in this file (when using -d).\n");
 287 }
 288
 289 int parse_args(int argc, char **argv)
 290 {
 291         int c;
 292
 293         while (1) {
 294                 int option_index = 0;
 295                 static struct option long_options[] = {
 296                         {"pidfile", 1, 0, 'p'},
 297                         {"help", 0, 0, 'h'},
 298                         {"version", 0, 0, 'V'},
 299                         {0, 0, 0, 0}
 300                 };
 301
 302                 c = getopt_long(argc, argv, "hs:o:d", long_options, &option_index);
 303                 if (c == -1)
 304                         break;
 305
 306                 switch (c) {
 307                 case 0:
 308                         printf("option %s", long_options[option_index].name);
 309                         if (optarg)
 310                                 printf(" with arg %s", optarg);
 311                         printf("\n");
 312                         break;
 313                 case 's':
 314                         sock_path = optarg;
 315                         break;
 316                 case 'o':
 317                         trace_path = optarg;
 318                         if(!is_directory(trace_path)) {
 319                                 ERR("Not a valid directory. (%s)", trace_path);
 320                                 return -1;
 321                         }
 322                         break;
 323                 case 'd':
 324                         daemon_mode = 1;
 325                         break;
 326                 case 'p':
 327                         pidfile = strdup(optarg);
 328                         break;
 329                 case 'h':
 330                         usage();
 331                         exit(0);
 332                 case 'V':
 333                         printf("Version 0.0\n");
 334                         break;
 335
 336                 default:
 337                         /* unknown option or other error; error is
 338                         printed by getopt, just return */
 339                         return -1;
 340                 }
 341         }
 342
 343         return 0;
 344 }
 345
 346 void sigterm_handler(int sig)
 347 {
 348         libustd_stop_instance(instance, 0);
 349 }
 350
 351 int start_ustd(int fd)
 352 {
 353         int result;
 354         sigset_t sigset;
 355         struct sigaction sa;
 356
 357         struct libustd_callbacks *callbacks = new_callbacks();
 358         if(!callbacks) {
 359                 PERROR("new_callbacks");
 360                 return 1;
 361         }
 362
 363         result = sigemptyset(&sigset);
 364         if(result == -1) {
 365                 PERROR("sigemptyset");
 366                 return 1;
 367         }
 368         sa.sa_handler = sigterm_handler;
 369         sa.sa_mask = sigset;
 370         sa.sa_flags = 0;
 371         result = sigaction(SIGTERM, &sa, NULL);
 372         if(result == -1) {
 373                 PERROR("sigaction");
 374                 return 1;
 375         }
 376         result = sigaction(SIGINT, &sa, NULL);
 377         if(result == -1) {
 378                 PERROR("sigaction");
 379                 return 1;
 380         }
 381
 382         instance = libustd_new_instance(callbacks, sock_path);
 383         if(!instance) {
 384                 ERR("failed to create libustd instance");
 385                 return 1;
 386         }
 387
 388         result = libustd_init_instance(instance);
 389         if(result) {
 390                 ERR("failed to initialize libustd instance");
 391                 return 1;
 392         }
 393
 394         /* setup handler for SIGPIPE */
 395         result = sigemptyset(&sigset);
 396         if(result == -1) {
 397                 PERROR("sigemptyset");
 398                 return 1;
 399         }
 400         result = sigaddset(&sigset, SIGPIPE);
 401         if(result == -1) {
 402                 PERROR("sigaddset");
 403                 return 1;
 404         }
 405         result = sigprocmask(SIG_BLOCK, &sigset, NULL);
 406         if(result == -1) {
 407                 PERROR("sigprocmask");
 408                 return 1;
 409         }
 410
 411         /* Write pidfile */
 412         if(pidfile) {
 413                 result = write_pidfile(pidfile, getpid());
 414                 if(result == -1) {
 415                         ERR("failed to write pidfile");
 416                         return 1;
 417                 }
 418         }
 419
 420         /* Notify parent that we are successfully started. */
 421         if(fd != -1) {
 422                 /* write any one character */
 423                 result = write(fd, "!", 1);
 424                 if(result == -1) {
 425                         PERROR("write");
 426                         return -1;
 427                 }
 428                 if(result != 1) {
 429                         ERR("Problem sending confirmation of daemon start to parent");
 430                         return -1;
 431                 }
 432                 result = close(fd);
 433                 if(result == -1) {
 434                         PERROR("close");
 435                 }
 436         }
 437
 438         libustd_start_instance(instance);
 439
 440         free(callbacks);
 441
 442         return 0;
 443 }
 444
 445 int start_ustd_daemon()
 446 {
 447         int result;
 448         int fd[2];
 449         pid_t child_pid;
 450
 451         result = pipe(fd);
 452
 453         result = child_pid = fork();
 454         if(result == -1) {
 455                 PERROR("fork");
 456                 return -1;
 457         }
 458         else if(result == 0) {
 459                 return start_ustd(fd[1]);
 460         }
 461         else {
 462                 char buf;
 463
 464                 result = read(fd[0], &buf, 1);
 465                 if(result == -1) {
 466                         PERROR("read");
 467                         return -1;
 468                 }
 469                 if(result != 1) {
 470                         ERR("did not receive valid confirmation that the daemon is started");
 471                         return -1;
 472                 }
 473
 474                 result = close(fd[0]);
 475                 if(result == -1) {
 476                         PERROR("close");
 477                 }
 478
 479                 DBG("The daemon is now successfully started");
 480         }
 481
 482         /* Wait for confirmation that the server is ready. */
 483
 484
 485         return 0;
 486 }
 487
 488 int main(int argc, char **argv)
 489 {
 490         int result;
 491
 492         result = parse_args(argc, argv);
 493         if(result == -1) {
 494                 exit(1);
 495         }
 496
 497         if(daemon_mode) {
 498                 result = start_ustd_daemon();
 499         }
 500         else {
 501                 result = start_ustd(-1);
 502         }
 503
 504         return result;
 505 }