tools/perf/builtin-daemon.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <internal/lib.h>
   3 #include <subcmd/parse-options.h>
   4 #include <api/fd/array.h>
   5 #include <api/fs/fs.h>
   6 #include <linux/zalloc.h>
   7 #include <linux/string.h>
   8 #include <linux/limits.h>
   9 #include <string.h>
  10 #include <sys/file.h>
  11 #include <signal.h>
  12 #include <stdlib.h>
  13 #include <time.h>
  14 #include <stdio.h>
  15 #include <unistd.h>
  16 #include <errno.h>
  17 #include <sys/inotify.h>
  18 #include <libgen.h>
  19 #include <sys/types.h>
  20 #include <sys/socket.h>
  21 #include <sys/un.h>
  22 #include <sys/stat.h>
  23 #include <sys/signalfd.h>
  24 #include <sys/wait.h>
  25 #include <poll.h>
  26 #include "builtin.h"
  27 #include "perf.h"
  28 #include "debug.h"
  29 #include "config.h"
  30 #include "util.h"
  31
  32 #define SESSION_OUTPUT  "output"
  33 #define SESSION_CONTROL "control"
  34 #define SESSION_ACK     "ack"
  35
  36 /*
  37  * Session states:
  38  *
  39  *   OK       - session is up and running
  40  *   RECONFIG - session is pending for reconfiguration,
  41  *              new values are already loaded in session object
  42  *   KILL     - session is pending to be killed
  43  *
  44  * Session object life and its state is maintained by
  45  * following functions:
  46  *
  47  *  setup_server_config
  48  *    - reads config file and setup session objects
  49  *      with following states:
  50  *
  51  *      OK       - no change needed
  52  *      RECONFIG - session needs to be changed
  53  *                 (run variable changed)
  54  *      KILL     - session needs to be killed
  55  *                 (session is no longer in config file)
  56  *
  57  *  daemon__reconfig
  58  *    - scans session objects and does following actions
  59  *      for states:
  60  *
  61  *      OK       - skip
  62  *      RECONFIG - session is killed and re-run with new config
  63  *      KILL     - session is killed
  64  *
  65  *    - all sessions have OK state on the function exit
  66  */
  67 enum daemon_session_state {
  68         OK,
  69         RECONFIG,
  70         KILL,
  71 };
  72
  73 struct daemon_session {
  74         char                            *base;
  75         char                            *name;
  76         char                            *run;
  77         char                            *control;
  78         int                              pid;
  79         struct list_head                 list;
  80         enum daemon_session_state        state;
  81         time_t                           start;
  82 };
  83
  84 struct daemon {
  85         const char              *config;
  86         char                    *config_real;
  87         char                    *config_base;
  88         const char              *csv_sep;
  89         const char              *base_user;
  90         char                    *base;
  91         struct list_head         sessions;
  92         FILE                    *out;
  93         char                     perf[PATH_MAX];
  94         int                      signal_fd;
  95         time_t                   start;
  96 };
  97
  98 static struct daemon __daemon = {
  99         .sessions = LIST_HEAD_INIT(__daemon.sessions),
 100 };
 101
 102 static const char * const daemon_usage[] = {
 103         "perf daemon start [<options>]",
 104         "perf daemon [<options>]",
 105         NULL
 106 };
 107
 108 static bool done;
 109
 110 static void sig_handler(int sig __maybe_unused)
 111 {
 112         done = true;
 113 }
 114
 115 static struct daemon_session *daemon__add_session(struct daemon *config, char *name)
 116 {
 117         struct daemon_session *session = zalloc(sizeof(*session));
 118
 119         if (!session)
 120                 return NULL;
 121
 122         session->name = strdup(name);
 123         if (!session->name) {
 124                 free(session);
 125                 return NULL;
 126         }
 127
 128         session->pid = -1;
 129         list_add_tail(&session->list, &config->sessions);
 130         return session;
 131 }
 132
 133 static struct daemon_session *daemon__find_session(struct daemon *daemon, char *name)
 134 {
 135         struct daemon_session *session;
 136
 137         list_for_each_entry(session, &daemon->sessions, list) {
 138                 if (!strcmp(session->name, name))
 139                         return session;
 140         }
 141
 142         return NULL;
 143 }
 144
 145 static int get_session_name(const char *var, char *session, int len)
 146 {
 147         const char *p = var + sizeof("session-") - 1;
 148
 149         while (*p != '.' && *p != 0x0 && len--)
 150                 *session++ = *p++;
 151
 152         *session = 0;
 153         return *p == '.' ? 0 : -EINVAL;
 154 }
 155
 156 static int session_config(struct daemon *daemon, const char *var, const char *value)
 157 {
 158         struct daemon_session *session;
 159         char name[100];
 160
 161         if (get_session_name(var, name, sizeof(name) - 1))
 162                 return -EINVAL;
 163
 164         var = strchr(var, '.');
 165         if (!var)
 166                 return -EINVAL;
 167
 168         var++;
 169
 170         session = daemon__find_session(daemon, name);
 171
 172         if (!session) {
 173                 /* New session is defined. */
 174                 session = daemon__add_session(daemon, name);
 175                 if (!session)
 176                         return -ENOMEM;
 177
 178                 pr_debug("reconfig: found new session %s\n", name);
 179
 180                 /* Trigger reconfig to start it. */
 181                 session->state = RECONFIG;
 182         } else if (session->state == KILL) {
 183                 /* Current session is defined, no action needed. */
 184                 pr_debug("reconfig: found current session %s\n", name);
 185                 session->state = OK;
 186         }
 187
 188         if (!strcmp(var, "run")) {
 189                 bool same = false;
 190
 191                 if (session->run)
 192                         same = !strcmp(session->run, value);
 193
 194                 if (!same) {
 195                         if (session->run) {
 196                                 free(session->run);
 197                                 pr_debug("reconfig: session %s is changed\n", name);
 198                         }
 199
 200                         session->run = strdup(value);
 201                         if (!session->run)
 202                                 return -ENOMEM;
 203
 204                         /*
 205                          * Either new or changed run value is defined,
 206                          * trigger reconfig for the session.
 207                          */
 208                         session->state = RECONFIG;
 209                 }
 210         }
 211
 212         return 0;
 213 }
 214
 215 static int server_config(const char *var, const char *value, void *cb)
 216 {
 217         struct daemon *daemon = cb;
 218
 219         if (strstarts(var, "session-")) {
 220                 return session_config(daemon, var, value);
 221         } else if (!strcmp(var, "daemon.base") && !daemon->base_user) {
 222                 if (daemon->base && strcmp(daemon->base, value)) {
 223                         pr_err("failed: can't redefine base, bailing out\n");
 224                         return -EINVAL;
 225                 }
 226                 daemon->base = strdup(value);
 227                 if (!daemon->base)
 228                         return -ENOMEM;
 229         }
 230
 231         return 0;
 232 }
 233
 234 static int client_config(const char *var, const char *value, void *cb)
 235 {
 236         struct daemon *daemon = cb;
 237
 238         if (!strcmp(var, "daemon.base") && !daemon->base_user) {
 239                 daemon->base = strdup(value);
 240                 if (!daemon->base)
 241                         return -ENOMEM;
 242         }
 243
 244         return 0;
 245 }
 246
 247 static int check_base(struct daemon *daemon)
 248 {
 249         struct stat st;
 250
 251         if (!daemon->base) {
 252                 pr_err("failed: base not defined\n");
 253                 return -EINVAL;
 254         }
 255
 256         if (stat(daemon->base, &st)) {
 257                 switch (errno) {
 258                 case EACCES:
 259                         pr_err("failed: permission denied for '%s' base\n",
 260                                daemon->base);
 261                         return -EACCES;
 262                 case ENOENT:
 263                         pr_err("failed: base '%s' does not exists\n",
 264                                daemon->base);
 265                         return -EACCES;
 266                 default:
 267                         pr_err("failed: can't access base '%s': %s\n",
 268                                daemon->base, strerror(errno));
 269                         return -errno;
 270                 }
 271         }
 272
 273         if ((st.st_mode & S_IFMT) != S_IFDIR) {
 274                 pr_err("failed: base '%s' is not directory\n",
 275                        daemon->base);
 276                 return -EINVAL;
 277         }
 278
 279         return 0;
 280 }
 281
 282 static int setup_client_config(struct daemon *daemon)
 283 {
 284         struct perf_config_set *set = perf_config_set__load_file(daemon->config_real);
 285         int err = -ENOMEM;
 286
 287         if (set) {
 288                 err = perf_config_set(set, client_config, daemon);
 289                 perf_config_set__delete(set);
 290         }
 291
 292         return err ?: check_base(daemon);
 293 }
 294
 295 static int setup_server_config(struct daemon *daemon)
 296 {
 297         struct perf_config_set *set;
 298         struct daemon_session *session;
 299         int err = -ENOMEM;
 300
 301         pr_debug("reconfig: started\n");
 302
 303         /*
 304          * Mark all sessions for kill, the server config
 305          * will set following states, see explanation at
 306          * enum daemon_session_state declaration.
 307          */
 308         list_for_each_entry(session, &daemon->sessions, list)
 309                 session->state = KILL;
 310
 311         set = perf_config_set__load_file(daemon->config_real);
 312         if (set) {
 313                 err = perf_config_set(set, server_config, daemon);
 314                 perf_config_set__delete(set);
 315         }
 316
 317         return err ?: check_base(daemon);
 318 }
 319
 320 static int daemon_session__run(struct daemon_session *session,
 321                                struct daemon *daemon)
 322 {
 323         char buf[PATH_MAX];
 324         char **argv;
 325         int argc, fd;
 326
 327         if (asprintf(&session->base, "%s/session-%s",
 328                      daemon->base, session->name) < 0) {
 329                 perror("failed: asprintf");
 330                 return -1;
 331         }
 332
 333         if (mkdir(session->base, 0755) && errno != EEXIST) {
 334                 perror("failed: mkdir");
 335                 return -1;
 336         }
 337
 338         session->start = time(NULL);
 339
 340         session->pid = fork();
 341         if (session->pid < 0)
 342                 return -1;
 343         if (session->pid > 0) {
 344                 pr_info("reconfig: ruining session [%s:%d]: %s\n",
 345                         session->name, session->pid, session->run);
 346                 return 0;
 347         }
 348
 349         if (chdir(session->base)) {
 350                 perror("failed: chdir");
 351                 return -1;
 352         }
 353
 354         fd = open("/dev/null", O_RDONLY);
 355         if (fd < 0) {
 356                 perror("failed: open /dev/null");
 357                 return -1;
 358         }
 359
 360         dup2(fd, 0);
 361         close(fd);
 362
 363         fd = open(SESSION_OUTPUT, O_RDWR|O_CREAT|O_TRUNC, 0644);
 364         if (fd < 0) {
 365                 perror("failed: open session output");
 366                 return -1;
 367         }
 368
 369         dup2(fd, 1);
 370         dup2(fd, 2);
 371         close(fd);
 372
 373         if (mkfifo(SESSION_CONTROL, 0600) && errno != EEXIST) {
 374                 perror("failed: create control fifo");
 375                 return -1;
 376         }
 377
 378         if (mkfifo(SESSION_ACK, 0600) && errno != EEXIST) {
 379                 perror("failed: create ack fifo");
 380                 return -1;
 381         }
 382
 383         scnprintf(buf, sizeof(buf), "%s record --control=fifo:%s,%s %s",
 384                   daemon->perf, SESSION_CONTROL, SESSION_ACK, session->run);
 385
 386         argv = argv_split(buf, &argc);
 387         if (!argv)
 388                 exit(-1);
 389
 390         exit(execve(daemon->perf, argv, NULL));
 391         return -1;
 392 }
 393
 394 static pid_t handle_signalfd(struct daemon *daemon)
 395 {
 396         struct daemon_session *session;
 397         struct signalfd_siginfo si;
 398         ssize_t err;
 399         int status;
 400         pid_t pid;
 401
 402         /*
 403          * Take signal fd data as pure signal notification and check all
 404          * the sessions state. The reason is that multiple signals can get
 405          * coalesced in kernel and we can receive only single signal even
 406          * if multiple SIGCHLD were generated.
 407          */
 408         err = read(daemon->signal_fd, &si, sizeof(struct signalfd_siginfo));
 409         if (err != sizeof(struct signalfd_siginfo)) {
 410                 pr_err("failed to read signal fd\n");
 411                 return -1;
 412         }
 413
 414         list_for_each_entry(session, &daemon->sessions, list) {
 415                 if (session->pid == -1)
 416                         continue;
 417
 418                 pid = waitpid(session->pid, &status, WNOHANG);
 419                 if (pid <= 0)
 420                         continue;
 421
 422                 if (WIFEXITED(status)) {
 423                         pr_info("session '%s' exited, status=%d\n",
 424                                 session->name, WEXITSTATUS(status));
 425                 } else if (WIFSIGNALED(status)) {
 426                         pr_info("session '%s' killed (signal %d)\n",
 427                                 session->name, WTERMSIG(status));
 428                 } else if (WIFSTOPPED(status)) {
 429                         pr_info("session '%s' stopped (signal %d)\n",
 430                                 session->name, WSTOPSIG(status));
 431                 } else {
 432                         pr_info("session '%s' Unexpected status (0x%x)\n",
 433                                 session->name, status);
 434                 }
 435
 436                 session->state = KILL;
 437                 session->pid = -1;
 438         }
 439
 440         return 0;
 441 }
 442
 443 static int daemon_session__wait(struct daemon_session *session, struct daemon *daemon,
 444                                 int secs)
 445 {
 446         struct pollfd pollfd = {
 447                 .fd     = daemon->signal_fd,
 448                 .events = POLLIN,
 449         };
 450         time_t start;
 451
 452         start = time(NULL);
 453
 454         do {
 455                 int err = poll(&pollfd, 1, 1000);
 456
 457                 if (err > 0) {
 458                         handle_signalfd(daemon);
 459                 } else if (err < 0) {
 460                         perror("failed: poll\n");
 461                         return -1;
 462                 }
 463
 464                 if (start + secs < time(NULL))
 465                         return -1;
 466         } while (session->pid != -1);
 467
 468         return 0;
 469 }
 470
 471 static bool daemon__has_alive_session(struct daemon *daemon)
 472 {
 473         struct daemon_session *session;
 474
 475         list_for_each_entry(session, &daemon->sessions, list) {
 476                 if (session->pid != -1)
 477                         return true;
 478         }
 479
 480         return false;
 481 }
 482
 483 static int daemon__wait(struct daemon *daemon, int secs)
 484 {
 485         struct pollfd pollfd = {
 486                 .fd     = daemon->signal_fd,
 487                 .events = POLLIN,
 488         };
 489         time_t start;
 490
 491         start = time(NULL);
 492
 493         do {
 494                 int err = poll(&pollfd, 1, 1000);
 495
 496                 if (err > 0) {
 497                         handle_signalfd(daemon);
 498                 } else if (err < 0) {
 499                         perror("failed: poll\n");
 500                         return -1;
 501                 }
 502
 503                 if (start + secs < time(NULL))
 504                         return -1;
 505         } while (daemon__has_alive_session(daemon));
 506
 507         return 0;
 508 }
 509
 510 static int daemon_session__control(struct daemon_session *session,
 511                                    const char *msg, bool do_ack)
 512 {
 513         struct pollfd pollfd = { .events = POLLIN, };
 514         char control_path[PATH_MAX];
 515         char ack_path[PATH_MAX];
 516         int control, ack = -1, len;
 517         char buf[20];
 518         int ret = -1;
 519         ssize_t err;
 520
 521         /* open the control file */
 522         scnprintf(control_path, sizeof(control_path), "%s/%s",
 523                   session->base, SESSION_CONTROL);
 524
 525         control = open(control_path, O_WRONLY|O_NONBLOCK);
 526         if (!control)
 527                 return -1;
 528
 529         if (do_ack) {
 530                 /* open the ack file */
 531                 scnprintf(ack_path, sizeof(ack_path), "%s/%s",
 532                           session->base, SESSION_ACK);
 533
 534                 ack = open(ack_path, O_RDONLY, O_NONBLOCK);
 535                 if (!ack) {
 536                         close(control);
 537                         return -1;
 538                 }
 539         }
 540
 541         /* write the command */
 542         len = strlen(msg);
 543
 544         err = writen(control, msg, len);
 545         if (err != len) {
 546                 pr_err("failed: write to control pipe: %d (%s)\n",
 547                        errno, control_path);
 548                 goto out;
 549         }
 550
 551         if (!do_ack)
 552                 goto out;
 553
 554         /* wait for an ack */
 555         pollfd.fd = ack;
 556
 557         if (!poll(&pollfd, 1, 2000)) {
 558                 pr_err("failed: control ack timeout\n");
 559                 goto out;
 560         }
 561
 562         if (!(pollfd.revents & POLLIN)) {
 563                 pr_err("failed: did not received an ack\n");
 564                 goto out;
 565         }
 566
 567         err = read(ack, buf, sizeof(buf));
 568         if (err > 0)
 569                 ret = strcmp(buf, "ack\n");
 570         else
 571                 perror("failed: read ack %d\n");
 572
 573 out:
 574         if (ack != -1)
 575                 close(ack);
 576
 577         close(control);
 578         return ret;
 579 }
 580
 581 static int setup_server_socket(struct daemon *daemon)
 582 {
 583         struct sockaddr_un addr;
 584         char path[PATH_MAX];
 585         int fd = socket(AF_UNIX, SOCK_STREAM, 0);
 586
 587         if (fd < 0) {
 588                 fprintf(stderr, "socket: %s\n", strerror(errno));
 589                 return -1;
 590         }
 591
 592         if (fcntl(fd, F_SETFD, FD_CLOEXEC)) {
 593                 perror("failed: fcntl FD_CLOEXEC");
 594                 close(fd);
 595                 return -1;
 596         }
 597
 598         scnprintf(path, sizeof(path), "%s/control", daemon->base);
 599
 600         if (strlen(path) + 1 >= sizeof(addr.sun_path)) {
 601                 pr_err("failed: control path too long '%s'\n", path);
 602                 close(fd);
 603                 return -1;
 604         }
 605
 606         memset(&addr, 0, sizeof(addr));
 607         addr.sun_family = AF_UNIX;
 608
 609         strlcpy(addr.sun_path, path, sizeof(addr.sun_path) - 1);
 610         unlink(path);
 611
 612         if (bind(fd, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
 613                 perror("failed: bind");
 614                 close(fd);
 615                 return -1;
 616         }
 617
 618         if (listen(fd, 1) == -1) {
 619                 perror("failed: listen");
 620                 close(fd);
 621                 return -1;
 622         }
 623
 624         return fd;
 625 }
 626
 627 enum {
 628         CMD_LIST   = 0,
 629         CMD_SIGNAL = 1,
 630         CMD_STOP   = 2,
 631         CMD_PING   = 3,
 632         CMD_MAX,
 633 };
 634
 635 #define SESSION_MAX 64
 636
 637 union cmd {
 638         int cmd;
 639
 640         /* CMD_LIST */
 641         struct {
 642                 int     cmd;
 643                 int     verbose;
 644                 char    csv_sep;
 645         } list;
 646
 647         /* CMD_SIGNAL */
 648         struct {
 649                 int     cmd;
 650                 int     sig;
 651                 char    name[SESSION_MAX];
 652         } signal;
 653
 654         /* CMD_PING */
 655         struct {
 656                 int     cmd;
 657                 char    name[SESSION_MAX];
 658         } ping;
 659 };
 660
 661 enum {
 662         PING_OK   = 0,
 663         PING_FAIL = 1,
 664         PING_MAX,
 665 };
 666
 667 static int daemon_session__ping(struct daemon_session *session)
 668 {
 669         return daemon_session__control(session, "ping", true) ?  PING_FAIL : PING_OK;
 670 }
 671
 672 static int cmd_session_list(struct daemon *daemon, union cmd *cmd, FILE *out)
 673 {
 674         char csv_sep = cmd->list.csv_sep;
 675         struct daemon_session *session;
 676         time_t curr = time(NULL);
 677
 678         if (csv_sep) {
 679                 fprintf(out, "%d%c%s%c%s%c%s/%s",
 680                         /* pid daemon  */
 681                         getpid(), csv_sep, "daemon",
 682                         /* base */
 683                         csv_sep, daemon->base,
 684                         /* output */
 685                         csv_sep, daemon->base, SESSION_OUTPUT);
 686
 687                 fprintf(out, "%c%s/%s",
 688                         /* lock */
 689                         csv_sep, daemon->base, "lock");
 690
 691                 fprintf(out, "%c%lu",
 692                         /* session up time */
 693                         csv_sep, (curr - daemon->start) / 60);
 694
 695                 fprintf(out, "\n");
 696         } else {
 697                 fprintf(out, "[%d:daemon] base: %s\n", getpid(), daemon->base);
 698                 if (cmd->list.verbose) {
 699                         fprintf(out, "  output:  %s/%s\n",
 700                                 daemon->base, SESSION_OUTPUT);
 701                         fprintf(out, "  lock:    %s/lock\n",
 702                                 daemon->base);
 703                         fprintf(out, "  up:      %lu minutes\n",
 704                                 (curr - daemon->start) / 60);
 705                 }
 706         }
 707
 708         list_for_each_entry(session, &daemon->sessions, list) {
 709                 if (csv_sep) {
 710                         fprintf(out, "%d%c%s%c%s",
 711                                 /* pid */
 712                                 session->pid,
 713                                 /* name */
 714                                 csv_sep, session->name,
 715                                 /* base */
 716                                 csv_sep, session->run);
 717
 718                         fprintf(out, "%c%s%c%s/%s",
 719                                 /* session dir */
 720                                 csv_sep, session->base,
 721                                 /* session output */
 722                                 csv_sep, session->base, SESSION_OUTPUT);
 723
 724                         fprintf(out, "%c%s/%s%c%s/%s",
 725                                 /* session control */
 726                                 csv_sep, session->base, SESSION_CONTROL,
 727                                 /* session ack */
 728                                 csv_sep, session->base, SESSION_ACK);
 729
 730                         fprintf(out, "%c%lu",
 731                                 /* session up time */
 732                                 csv_sep, (curr - session->start) / 60);
 733
 734                         fprintf(out, "\n");
 735                 } else {
 736                         fprintf(out, "[%d:%s] perf record %s\n",
 737                                 session->pid, session->name, session->run);
 738                         if (!cmd->list.verbose)
 739                                 continue;
 740                         fprintf(out, "  base:    %s\n",
 741                                 session->base);
 742                         fprintf(out, "  output:  %s/%s\n",
 743                                 session->base, SESSION_OUTPUT);
 744                         fprintf(out, "  control: %s/%s\n",
 745                                 session->base, SESSION_CONTROL);
 746                         fprintf(out, "  ack:     %s/%s\n",
 747                                 session->base, SESSION_ACK);
 748                         fprintf(out, "  up:      %lu minutes\n",
 749                                 (curr - session->start) / 60);
 750                 }
 751         }
 752
 753         return 0;
 754 }
 755
 756 static int daemon_session__signal(struct daemon_session *session, int sig)
 757 {
 758         if (session->pid < 0)
 759                 return -1;
 760         return kill(session->pid, sig);
 761 }
 762
 763 static int cmd_session_kill(struct daemon *daemon, union cmd *cmd, FILE *out)
 764 {
 765         struct daemon_session *session;
 766         bool all = false;
 767
 768         all = !strcmp(cmd->signal.name, "all");
 769
 770         list_for_each_entry(session, &daemon->sessions, list) {
 771                 if (all || !strcmp(cmd->signal.name, session->name)) {
 772                         daemon_session__signal(session, cmd->signal.sig);
 773                         fprintf(out, "signal %d sent to session '%s [%d]'\n",
 774                                 cmd->signal.sig, session->name, session->pid);
 775                 }
 776         }
 777
 778         return 0;
 779 }
 780
 781 static const char *ping_str[PING_MAX] = {
 782         [PING_OK]   = "OK",
 783         [PING_FAIL] = "FAIL",
 784 };
 785
 786 static int cmd_session_ping(struct daemon *daemon, union cmd *cmd, FILE *out)
 787 {
 788         struct daemon_session *session;
 789         bool all = false, found = false;
 790
 791         all = !strcmp(cmd->ping.name, "all");
 792
 793         list_for_each_entry(session, &daemon->sessions, list) {
 794                 if (all || !strcmp(cmd->ping.name, session->name)) {
 795                         int state = daemon_session__ping(session);
 796
 797                         fprintf(out, "%-4s %s\n", ping_str[state], session->name);
 798                         found = true;
 799                 }
 800         }
 801
 802         if (!found && !all) {
 803                 fprintf(out, "%-4s %s (not found)\n",
 804                         ping_str[PING_FAIL], cmd->ping.name);
 805         }
 806         return 0;
 807 }
 808
 809 static int handle_server_socket(struct daemon *daemon, int sock_fd)
 810 {
 811         int ret = -1, fd;
 812         FILE *out = NULL;
 813         union cmd cmd;
 814
 815         fd = accept(sock_fd, NULL, NULL);
 816         if (fd < 0) {
 817                 perror("failed: accept");
 818                 return -1;
 819         }
 820
 821         if (sizeof(cmd) != readn(fd, &cmd, sizeof(cmd))) {
 822                 perror("failed: read");
 823                 goto out;
 824         }
 825
 826         out = fdopen(fd, "w");
 827         if (!out) {
 828                 perror("failed: fdopen");
 829                 goto out;
 830         }
 831
 832         switch (cmd.cmd) {
 833         case CMD_LIST:
 834                 ret = cmd_session_list(daemon, &cmd, out);
 835                 break;
 836         case CMD_SIGNAL:
 837                 ret = cmd_session_kill(daemon, &cmd, out);
 838                 break;
 839         case CMD_STOP:
 840                 done = 1;
 841                 ret = 0;
 842                 pr_debug("perf daemon is exciting\n");
 843                 break;
 844         case CMD_PING:
 845                 ret = cmd_session_ping(daemon, &cmd, out);
 846                 break;
 847         default:
 848                 break;
 849         }
 850
 851         fclose(out);
 852 out:
 853         /* If out is defined, then fd is closed via fclose. */
 854         if (!out)
 855                 close(fd);
 856         return ret;
 857 }
 858
 859 static int setup_client_socket(struct daemon *daemon)
 860 {
 861         struct sockaddr_un addr;
 862         char path[PATH_MAX];
 863         int fd = socket(AF_UNIX, SOCK_STREAM, 0);
 864
 865         if (fd == -1) {
 866                 perror("failed: socket");
 867                 return -1;
 868         }
 869
 870         scnprintf(path, sizeof(path), "%s/control", daemon->base);
 871
 872         if (strlen(path) + 1 >= sizeof(addr.sun_path)) {
 873                 pr_err("failed: control path too long '%s'\n", path);
 874                 close(fd);
 875                 return -1;
 876         }
 877
 878         memset(&addr, 0, sizeof(addr));
 879         addr.sun_family = AF_UNIX;
 880         strlcpy(addr.sun_path, path, sizeof(addr.sun_path) - 1);
 881
 882         if (connect(fd, (struct sockaddr *) &addr, sizeof(addr)) == -1) {
 883                 perror("failed: connect");
 884                 close(fd);
 885                 return -1;
 886         }
 887
 888         return fd;
 889 }
 890
 891 static void daemon_session__kill(struct daemon_session *session,
 892                                  struct daemon *daemon)
 893 {
 894         int how = 0;
 895
 896         do {
 897                 switch (how) {
 898                 case 0:
 899                         daemon_session__control(session, "stop", false);
 900                         break;
 901                 case 1:
 902                         daemon_session__signal(session, SIGTERM);
 903                         break;
 904                 case 2:
 905                         daemon_session__signal(session, SIGKILL);
 906                         break;
 907                 default:
 908                         pr_err("failed to wait for session %s\n",
 909                                session->name);
 910                         return;
 911                 }
 912                 how++;
 913
 914         } while (daemon_session__wait(session, daemon, 10));
 915 }
 916
 917 static void daemon__signal(struct daemon *daemon, int sig)
 918 {
 919         struct daemon_session *session;
 920
 921         list_for_each_entry(session, &daemon->sessions, list)
 922                 daemon_session__signal(session, sig);
 923 }
 924
 925 static void daemon_session__delete(struct daemon_session *session)
 926 {
 927         free(session->base);
 928         free(session->name);
 929         free(session->run);
 930         free(session);
 931 }
 932
 933 static void daemon_session__remove(struct daemon_session *session)
 934 {
 935         list_del(&session->list);
 936         daemon_session__delete(session);
 937 }
 938
 939 static void daemon__stop(struct daemon *daemon)
 940 {
 941         struct daemon_session *session;
 942
 943         list_for_each_entry(session, &daemon->sessions, list)
 944                 daemon_session__control(session, "stop", false);
 945 }
 946
 947 static void daemon__kill(struct daemon *daemon)
 948 {
 949         int how = 0;
 950
 951         do {
 952                 switch (how) {
 953                 case 0:
 954                         daemon__stop(daemon);
 955                         break;
 956                 case 1:
 957                         daemon__signal(daemon, SIGTERM);
 958                         break;
 959                 case 2:
 960                         daemon__signal(daemon, SIGKILL);
 961                         break;
 962                 default:
 963                         pr_err("failed to wait for sessions\n");
 964                         return;
 965                 }
 966                 how++;
 967
 968         } while (daemon__wait(daemon, 10));
 969 }
 970
 971 static void daemon__exit(struct daemon *daemon)
 972 {
 973         struct daemon_session *session, *h;
 974
 975         list_for_each_entry_safe(session, h, &daemon->sessions, list)
 976                 daemon_session__remove(session);
 977
 978         free(daemon->config_real);
 979         free(daemon->config_base);
 980         free(daemon->base);
 981 }
 982
 983 static int daemon__reconfig(struct daemon *daemon)
 984 {
 985         struct daemon_session *session, *n;
 986
 987         list_for_each_entry_safe(session, n, &daemon->sessions, list) {
 988                 /* No change. */
 989                 if (session->state == OK)
 990                         continue;
 991
 992                 /* Remove session. */
 993                 if (session->state == KILL) {
 994                         if (session->pid > 0) {
 995                                 daemon_session__kill(session, daemon);
 996                                 pr_info("reconfig: session '%s' killed\n", session->name);
 997                         }
 998                         daemon_session__remove(session);
 999                         continue;
1000                 }
1001
1002                 /* Reconfig session. */
1003                 if (session->pid > 0) {
1004                         daemon_session__kill(session, daemon);
1005                         pr_info("reconfig: session '%s' killed\n", session->name);
1006                 }
1007                 if (daemon_session__run(session, daemon))
1008                         return -1;
1009
1010                 session->state = OK;
1011         }
1012
1013         return 0;
1014 }
1015
1016 static int setup_config_changes(struct daemon *daemon)
1017 {
1018         char *basen = strdup(daemon->config_real);
1019         char *dirn  = strdup(daemon->config_real);
1020         char *base, *dir;
1021         int fd, wd = -1;
1022
1023         if (!dirn || !basen)
1024                 goto out;
1025
1026         fd = inotify_init1(IN_NONBLOCK|O_CLOEXEC);
1027         if (fd < 0) {
1028                 perror("failed: inotify_init");
1029                 goto out;
1030         }
1031
1032         dir = dirname(dirn);
1033         base = basename(basen);
1034         pr_debug("config file: %s, dir: %s\n", base, dir);
1035
1036         wd = inotify_add_watch(fd, dir, IN_CLOSE_WRITE);
1037         if (wd >= 0) {
1038                 daemon->config_base = strdup(base);
1039                 if (!daemon->config_base) {
1040                         close(fd);
1041                         wd = -1;
1042                 }
1043         } else {
1044                 perror("failed: inotify_add_watch");
1045         }
1046
1047 out:
1048         free(basen);
1049         free(dirn);
1050         return wd < 0 ? -1 : fd;
1051 }
1052
1053 static bool process_inotify_event(struct daemon *daemon, char *buf, ssize_t len)
1054 {
1055         char *p = buf;
1056
1057         while (p < (buf + len)) {
1058                 struct inotify_event *event = (struct inotify_event *) p;
1059
1060                 /*
1061                  * We monitor config directory, check if our
1062                  * config file was changes.
1063                  */
1064                 if ((event->mask & IN_CLOSE_WRITE) &&
1065                     !(event->mask & IN_ISDIR)) {
1066                         if (!strcmp(event->name, daemon->config_base))
1067                                 return true;
1068                 }
1069                 p += sizeof(*event) + event->len;
1070         }
1071         return false;
1072 }
1073
1074 static int handle_config_changes(struct daemon *daemon, int conf_fd,
1075                                  bool *config_changed)
1076 {
1077         char buf[4096];
1078         ssize_t len;
1079
1080         while (!(*config_changed)) {
1081                 len = read(conf_fd, buf, sizeof(buf));
1082                 if (len == -1) {
1083                         if (errno != EAGAIN) {
1084                                 perror("failed: read");
1085                                 return -1;
1086                         }
1087                         return 0;
1088                 }
1089                 *config_changed = process_inotify_event(daemon, buf, len);
1090         }
1091         return 0;
1092 }
1093
1094 static int setup_config(struct daemon *daemon)
1095 {
1096         if (daemon->base_user) {
1097                 daemon->base = strdup(daemon->base_user);
1098                 if (!daemon->base)
1099                         return -ENOMEM;
1100         }
1101
1102         if (daemon->config) {
1103                 char *real = realpath(daemon->config, NULL);
1104
1105                 if (!real) {
1106                         perror("failed: realpath");
1107                         return -1;
1108                 }
1109                 daemon->config_real = real;
1110                 return 0;
1111         }
1112
1113         if (perf_config_system() && !access(perf_etc_perfconfig(), R_OK))
1114                 daemon->config_real = strdup(perf_etc_perfconfig());
1115         else if (perf_config_global() && perf_home_perfconfig())
1116                 daemon->config_real = strdup(perf_home_perfconfig());
1117
1118         return daemon->config_real ? 0 : -1;
1119 }
1120
1121 #ifndef F_TLOCK
1122 #define F_TLOCK 2
1123
1124 #include <sys/file.h>
1125
1126 static int lockf(int fd, int cmd, off_t len)
1127 {
1128         if (cmd != F_TLOCK || len != 0)
1129                 return -1;
1130
1131         return flock(fd, LOCK_EX | LOCK_NB);
1132 }
1133 #endif // F_TLOCK
1134
1135 /*
1136  * Each daemon tries to create and lock BASE/lock file,
1137  * if it's successful we are sure we're the only daemon
1138  * running over the BASE.
1139  *
1140  * Once daemon is finished, file descriptor to lock file
1141  * is closed and lock is released.
1142  */
1143 static int check_lock(struct daemon *daemon)
1144 {
1145         char path[PATH_MAX];
1146         char buf[20];
1147         int fd, pid;
1148         ssize_t len;
1149
1150         scnprintf(path, sizeof(path), "%s/lock", daemon->base);
1151
1152         fd = open(path, O_RDWR|O_CREAT|O_CLOEXEC, 0640);
1153         if (fd < 0)
1154                 return -1;
1155
1156         if (lockf(fd, F_TLOCK, 0) < 0) {
1157                 filename__read_int(path, &pid);
1158                 fprintf(stderr, "failed: another perf daemon (pid %d) owns %s\n",
1159                         pid, daemon->base);
1160                 close(fd);
1161                 return -1;
1162         }
1163
1164         scnprintf(buf, sizeof(buf), "%d", getpid());
1165         len = strlen(buf);
1166
1167         if (write(fd, buf, len) != len) {
1168                 perror("failed: write");
1169                 close(fd);
1170                 return -1;
1171         }
1172
1173         if (ftruncate(fd, len)) {
1174                 perror("failed: ftruncate");
1175                 close(fd);
1176                 return -1;
1177         }
1178
1179         return 0;
1180 }
1181
1182 static int go_background(struct daemon *daemon)
1183 {
1184         int pid, fd;
1185
1186         pid = fork();
1187         if (pid < 0)
1188                 return -1;
1189
1190         if (pid > 0)
1191                 return 1;
1192
1193         if (setsid() < 0)
1194                 return -1;
1195
1196         if (check_lock(daemon))
1197                 return -1;
1198
1199         umask(0);
1200
1201         if (chdir(daemon->base)) {
1202                 perror("failed: chdir");
1203                 return -1;
1204         }
1205
1206         fd = open("output", O_RDWR|O_CREAT|O_TRUNC, 0644);
1207         if (fd < 0) {
1208                 perror("failed: open");
1209                 return -1;
1210         }
1211
1212         if (fcntl(fd, F_SETFD, FD_CLOEXEC)) {
1213                 perror("failed: fcntl FD_CLOEXEC");
1214                 close(fd);
1215                 return -1;
1216         }
1217
1218         close(0);
1219         dup2(fd, 1);
1220         dup2(fd, 2);
1221         close(fd);
1222
1223         daemon->out = fdopen(1, "w");
1224         if (!daemon->out) {
1225                 close(1);
1226                 close(2);
1227                 return -1;
1228         }
1229
1230         setbuf(daemon->out, NULL);
1231         return 0;
1232 }
1233
1234 static int setup_signalfd(struct daemon *daemon)
1235 {
1236         sigset_t mask;
1237
1238         sigemptyset(&mask);
1239         sigaddset(&mask, SIGCHLD);
1240
1241         if (sigprocmask(SIG_BLOCK, &mask, NULL) == -1)
1242                 return -1;
1243
1244         daemon->signal_fd = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC);
1245         return daemon->signal_fd;
1246 }
1247
1248 static int __cmd_start(struct daemon *daemon, struct option parent_options[],
1249                        int argc, const char **argv)
1250 {
1251         bool foreground = false;
1252         struct option start_options[] = {
1253                 OPT_BOOLEAN('f', "foreground", &foreground, "stay on console"),
1254                 OPT_PARENT(parent_options),
1255                 OPT_END()
1256         };
1257         int sock_fd = -1, conf_fd = -1, signal_fd = -1;
1258         int sock_pos, file_pos, signal_pos;
1259         struct fdarray fda;
1260         int err = 0;
1261
1262         argc = parse_options(argc, argv, start_options, daemon_usage, 0);
1263         if (argc)
1264                 usage_with_options(daemon_usage, start_options);
1265
1266         daemon->start = time(NULL);
1267
1268         if (setup_config(daemon)) {
1269                 pr_err("failed: config not found\n");
1270                 return -1;
1271         }
1272
1273         if (setup_server_config(daemon))
1274                 return -1;
1275
1276         if (foreground && check_lock(daemon))
1277                 return -1;
1278
1279         if (!foreground) {
1280                 err = go_background(daemon);
1281                 if (err) {
1282                         /* original process, exit normally */
1283                         if (err == 1)
1284                                 err = 0;
1285                         daemon__exit(daemon);
1286                         return err;
1287                 }
1288         }
1289
1290         debug_set_file(daemon->out);
1291         debug_set_display_time(true);
1292
1293         pr_info("daemon started (pid %d)\n", getpid());
1294
1295         fdarray__init(&fda, 3);
1296
1297         sock_fd = setup_server_socket(daemon);
1298         if (sock_fd < 0)
1299                 goto out;
1300
1301         conf_fd = setup_config_changes(daemon);
1302         if (conf_fd < 0)
1303                 goto out;
1304
1305         signal_fd = setup_signalfd(daemon);
1306         if (signal_fd < 0)
1307                 goto out;
1308
1309         sock_pos = fdarray__add(&fda, sock_fd, POLLIN|POLLERR|POLLHUP, 0);
1310         if (sock_pos < 0)
1311                 goto out;
1312
1313         file_pos = fdarray__add(&fda, conf_fd, POLLIN|POLLERR|POLLHUP, 0);
1314         if (file_pos < 0)
1315                 goto out;
1316
1317         signal_pos = fdarray__add(&fda, signal_fd, POLLIN|POLLERR|POLLHUP, 0);
1318         if (signal_pos < 0)
1319                 goto out;
1320
1321         signal(SIGINT, sig_handler);
1322         signal(SIGTERM, sig_handler);
1323         signal(SIGPIPE, SIG_IGN);
1324
1325         while (!done && !err) {
1326                 err = daemon__reconfig(daemon);
1327
1328                 if (!err && fdarray__poll(&fda, -1)) {
1329                         bool reconfig = false;
1330
1331                         if (fda.entries[sock_pos].revents & POLLIN)
1332                                 err = handle_server_socket(daemon, sock_fd);
1333                         if (fda.entries[file_pos].revents & POLLIN)
1334                                 err = handle_config_changes(daemon, conf_fd, &reconfig);
1335                         if (fda.entries[signal_pos].revents & POLLIN)
1336                                 err = handle_signalfd(daemon) < 0;
1337
1338                         if (reconfig)
1339                                 err = setup_server_config(daemon);
1340                 }
1341         }
1342
1343 out:
1344         fdarray__exit(&fda);
1345
1346         daemon__kill(daemon);
1347         daemon__exit(daemon);
1348
1349         if (sock_fd != -1)
1350                 close(sock_fd);
1351         if (conf_fd != -1)
1352                 close(conf_fd);
1353         if (signal_fd != -1)
1354                 close(signal_fd);
1355
1356         pr_info("daemon exited\n");
1357         fclose(daemon->out);
1358         return err;
1359 }
1360
1361 static int send_cmd(struct daemon *daemon, union cmd *cmd)
1362 {
1363         int ret = -1, fd;
1364         char *line = NULL;
1365         size_t len = 0;
1366         ssize_t nread;
1367         FILE *in = NULL;
1368
1369         if (setup_client_config(daemon))
1370                 return -1;
1371
1372         fd = setup_client_socket(daemon);
1373         if (fd < 0)
1374                 return -1;
1375
1376         if (sizeof(*cmd) != writen(fd, cmd, sizeof(*cmd))) {
1377                 perror("failed: write");
1378                 goto out;
1379         }
1380
1381         in = fdopen(fd, "r");
1382         if (!in) {
1383                 perror("failed: fdopen");
1384                 goto out;
1385         }
1386
1387         while ((nread = getline(&line, &len, in)) != -1) {
1388                 if (fwrite(line, nread, 1, stdout) != 1)
1389                         goto out_fclose;
1390                 fflush(stdout);
1391         }
1392
1393         ret = 0;
1394 out_fclose:
1395         fclose(in);
1396         free(line);
1397 out:
1398         /* If in is defined, then fd is closed via fclose. */
1399         if (!in)
1400                 close(fd);
1401         return ret;
1402 }
1403
1404 static int send_cmd_list(struct daemon *daemon)
1405 {
1406         union cmd cmd = { .cmd = CMD_LIST, };
1407
1408         cmd.list.verbose = verbose;
1409         cmd.list.csv_sep = daemon->csv_sep ? *daemon->csv_sep : 0;
1410
1411         return send_cmd(daemon, &cmd);
1412 }
1413
1414 static int __cmd_signal(struct daemon *daemon, struct option parent_options[],
1415                         int argc, const char **argv)
1416 {
1417         const char *name = "all";
1418         struct option start_options[] = {
1419                 OPT_STRING(0, "session", &name, "session",
1420                         "Sent signal to specific session"),
1421                 OPT_PARENT(parent_options),
1422                 OPT_END()
1423         };
1424         union cmd cmd;
1425
1426         argc = parse_options(argc, argv, start_options, daemon_usage, 0);
1427         if (argc)
1428                 usage_with_options(daemon_usage, start_options);
1429
1430         if (setup_config(daemon)) {
1431                 pr_err("failed: config not found\n");
1432                 return -1;
1433         }
1434
1435         cmd.signal.cmd = CMD_SIGNAL,
1436         cmd.signal.sig = SIGUSR2;
1437         strncpy(cmd.signal.name, name, sizeof(cmd.signal.name) - 1);
1438
1439         return send_cmd(daemon, &cmd);
1440 }
1441
1442 static int __cmd_stop(struct daemon *daemon, struct option parent_options[],
1443                         int argc, const char **argv)
1444 {
1445         struct option start_options[] = {
1446                 OPT_PARENT(parent_options),
1447                 OPT_END()
1448         };
1449         union cmd cmd = { .cmd = CMD_STOP, };
1450
1451         argc = parse_options(argc, argv, start_options, daemon_usage, 0);
1452         if (argc)
1453                 usage_with_options(daemon_usage, start_options);
1454
1455         if (setup_config(daemon)) {
1456                 pr_err("failed: config not found\n");
1457                 return -1;
1458         }
1459
1460         return send_cmd(daemon, &cmd);
1461 }
1462
1463 static int __cmd_ping(struct daemon *daemon, struct option parent_options[],
1464                       int argc, const char **argv)
1465 {
1466         const char *name = "all";
1467         struct option ping_options[] = {
1468                 OPT_STRING(0, "session", &name, "session",
1469                         "Ping to specific session"),
1470                 OPT_PARENT(parent_options),
1471                 OPT_END()
1472         };
1473         union cmd cmd = { .cmd = CMD_PING, };
1474
1475         argc = parse_options(argc, argv, ping_options, daemon_usage, 0);
1476         if (argc)
1477                 usage_with_options(daemon_usage, ping_options);
1478
1479         if (setup_config(daemon)) {
1480                 pr_err("failed: config not found\n");
1481                 return -1;
1482         }
1483
1484         scnprintf(cmd.ping.name, sizeof(cmd.ping.name), "%s", name);
1485         return send_cmd(daemon, &cmd);
1486 }
1487
1488 int cmd_daemon(int argc, const char **argv)
1489 {
1490         struct option daemon_options[] = {
1491                 OPT_INCR('v', "verbose", &verbose, "be more verbose"),
1492                 OPT_STRING(0, "config", &__daemon.config,
1493                         "config file", "config file path"),
1494                 OPT_STRING(0, "base", &__daemon.base_user,
1495                         "directory", "base directory"),
1496                 OPT_STRING_OPTARG('x', "field-separator", &__daemon.csv_sep,
1497                         "field separator", "print counts with custom separator", ","),
1498                 OPT_END()
1499         };
1500
1501         perf_exe(__daemon.perf, sizeof(__daemon.perf));
1502         __daemon.out = stdout;
1503
1504         argc = parse_options(argc, argv, daemon_options, daemon_usage,
1505                              PARSE_OPT_STOP_AT_NON_OPTION);
1506
1507         if (argc) {
1508                 if (!strcmp(argv[0], "start"))
1509                         return __cmd_start(&__daemon, daemon_options, argc, argv);
1510                 if (!strcmp(argv[0], "signal"))
1511                         return __cmd_signal(&__daemon, daemon_options, argc, argv);
1512                 else if (!strcmp(argv[0], "stop"))
1513                         return __cmd_stop(&__daemon, daemon_options, argc, argv);
1514                 else if (!strcmp(argv[0], "ping"))
1515                         return __cmd_ping(&__daemon, daemon_options, argc, argv);
1516
1517                 pr_err("failed: unknown command '%s'\n", argv[0]);
1518                 return -1;
1519         }
1520
1521         if (setup_config(&__daemon)) {
1522                 pr_err("failed: config not found\n");
1523                 return -1;
1524         }
1525
1526         return send_cmd_list(&__daemon);
1527 }