popen.c

   1 /*@ S-nail - a mail user agent derived from Berkeley Mail.
   2  *@ Handling of pipes, child processes, temporary files, file enwrapping.
   3  *
   4  * Copyright (c) 2000-2004 Gunnar Ritter, Freiburg i. Br., Germany.
   5  * Copyright (c) 2012 - 2014 Steffen (Daode) Nurpmeso <sdaoden@users.sf.net>.
   6  */
   7 /*
   8  * Copyright (c) 1980, 1993
   9  * The Regents of the University of California.  All rights reserved.
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions and the following disclaimer.
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in the
  18  *    documentation and/or other materials provided with the distribution.
  19  * 3. All advertising materials mentioning features or use of this software
  20  *    must display the following acknowledgement:
  21  *    This product includes software developed by the University of
  22  *    California, Berkeley and its contributors.
  23  * 4. Neither the name of the University nor the names of its contributors
  24  *    may be used to endorse or promote products derived from this software
  25  *    without specific prior written permission.
  26  *
  27  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  28  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  29  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  30  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  31  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  32  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  33  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  34  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  35  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  36  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  37  * SUCH DAMAGE.
  38  */
  39
  40 #ifndef HAVE_AMALGAMATION
  41 # include "nail.h"
  42 #endif
  43
  44 #include <sys/wait.h>
  45
  46 #include <fcntl.h>
  47
  48 #define READ               0
  49 #define WRITE              1
  50
  51 #ifndef O_CLOEXEC
  52 # define _OUR_CLOEXEC
  53 # define O_CLOEXEC         0
  54 # define _SET_CLOEXEC(FD)  do fcntl((FD), F_SETFD, FD_CLOEXEC); while (0)
  55 #else
  56 # define _SET_CLOEXEC(FD)  do {} while (0)
  57 #endif
  58
  59 struct fp {
  60    FILE        *fp;
  61    struct fp   *link;
  62    char        *realfile;
  63    long        offset;
  64    int         omode;
  65    int         pipe;
  66    int         pid;
  67    enum {
  68       FP_RAW      = 0,
  69       FP_GZIP     = 1<<0,
  70       FP_XZ       = 1<<1,
  71       FP_BZIP2    = 1<<2,
  72       FP_IMAP     = 1<<3,
  73       FP_MAILDIR  = 1<<4,
  74       FP_MASK     = (1<<5) - 1,
  75       FP_READONLY = 1<<5
  76    }           compressed;
  77 };
  78
  79 struct child {
  80    int         pid;
  81    char        done;
  82    char        free;
  83    int         status;
  84    struct child *link;
  85 };
  86
  87 static struct fp     *fp_head;
  88 static struct child  *_popen_child;
  89
  90 static int           scan_mode(char const *mode, int *omode);
  91 static void          register_file(FILE *fp, int omode, int ispipe, int pid,
  92                         int compressed, char const *realfile, long offset);
  93 static enum okay     _compress(struct fp *fpp);
  94 static int           _decompress(int compression, int infd, int outfd);
  95 static enum okay     unregister_file(FILE *fp);
  96 static int           file_pid(FILE *fp);
  97
  98 /* Handle SIGCHLD */
  99 static void          _sigchld(int signo);
 100
 101 static int           wait_command(int pid);
 102 static struct child *findchild(int pid);
 103 static void          delchild(struct child *cp);
 104
 105 static int
 106 scan_mode(char const *mode, int *omode)
 107 {
 108    static struct {
 109       char const  mode[4];
 110       int         omode;
 111    } const maps[] = {
 112       {"r", O_RDONLY},
 113       {"w", O_WRONLY | O_CREAT | O_TRUNC},
 114       {"wx", O_WRONLY | O_CREAT | O_EXCL},
 115       {"a", O_WRONLY | O_APPEND | O_CREAT},
 116       {"a+", O_RDWR | O_APPEND},
 117       {"r+", O_RDWR},
 118       {"w+", O_RDWR | O_CREAT | O_EXCL}
 119    };
 120
 121    int i;
 122    NYD2_ENTER;
 123
 124    for (i = 0; UICMP(z, i, <, NELEM(maps)); ++i)
 125       if (!strcmp(maps[i].mode, mode)) {
 126          *omode = maps[i].omode;
 127          i = 0;
 128          goto jleave;
 129       }
 130
 131    alert(_("Internal error: bad stdio open mode %s\n"), mode);
 132    errno = EINVAL;
 133    *omode = 0; /* (silence CC) */
 134    i = -1;
 135 jleave:
 136    NYD2_LEAVE;
 137    return i;
 138 }
 139
 140 static void
 141 register_file(FILE *fp, int omode, int ispipe, int pid, int compressed,
 142    char const *realfile, long offset)
 143 {
 144    struct fp *fpp;
 145    NYD_ENTER;
 146
 147    fpp = smalloc(sizeof *fpp);
 148    fpp->fp = fp;
 149    fpp->omode = omode;
 150    fpp->pipe = ispipe;
 151    fpp->pid = pid;
 152    fpp->link = fp_head;
 153    fpp->compressed = compressed;
 154    fpp->realfile = (realfile != NULL) ? sstrdup(realfile) : NULL;
 155    fpp->offset = offset;
 156    fp_head = fpp;
 157    NYD_LEAVE;
 158 }
 159
 160 static enum okay
 161 _compress(struct fp *fpp)
 162 {
 163    char const *cmd[2];
 164    int outfd;
 165    enum okay rv;
 166    NYD_ENTER;
 167
 168    if (fpp->omode == O_RDONLY) {
 169       rv = OKAY;
 170       goto jleave;
 171    }
 172    rv = STOP;
 173
 174    fflush(fpp->fp);
 175    clearerr(fpp->fp);
 176    if (fseek(fpp->fp, fpp->offset, SEEK_SET) == -1)
 177       goto jleave;
 178
 179 #ifdef HAVE_IMAP
 180    if ((fpp->compressed & FP_MASK) == FP_IMAP) {
 181       rv = imap_append(fpp->realfile, fpp->fp);
 182       goto jleave;
 183    }
 184 #endif
 185    if ((fpp->compressed & FP_MASK) == FP_MAILDIR) {
 186       rv = maildir_append(fpp->realfile, fpp->fp);
 187       goto jleave;
 188    }
 189
 190    outfd = open(fpp->realfile, (fpp->omode | O_CREAT) & ~O_EXCL, 0666);
 191    if (outfd == -1) {
 192       fprintf(stderr, "Fatal: cannot create ");
 193       perror(fpp->realfile);
 194       goto jleave;
 195    }
 196    if (!(fpp->omode & O_APPEND))
 197       ftruncate(outfd, 0);
 198    switch (fpp->compressed & FP_MASK) {
 199    case FP_GZIP:
 200       cmd[0] = "gzip";  cmd[1] = "-c"; break;
 201    case FP_BZIP2:
 202       cmd[0] = "bzip2"; cmd[1] = "-c"; break;
 203    case FP_XZ:
 204       cmd[0] = "xz";    cmd[1] = "-c"; break;
 205    default:
 206       cmd[0] = "cat";   cmd[1] = NULL; break;
 207    }
 208    if (run_command(cmd[0], 0, fileno(fpp->fp), outfd, cmd[1], NULL, NULL) >= 0)
 209       rv = OKAY;
 210    close(outfd);
 211 jleave:
 212    NYD_LEAVE;
 213    return rv;
 214 }
 215
 216 static int
 217 _decompress(int compression, int infd, int outfd)
 218 {
 219    char const *cmd[2];
 220    int rv;
 221    NYD_ENTER;
 222
 223    switch (compression & FP_MASK) {
 224    case FP_GZIP:     cmd[0] = "gzip";  cmd[1] = "-cd"; break;
 225    case FP_BZIP2:    cmd[0] = "bzip2"; cmd[1] = "-cd"; break;
 226    case FP_XZ:       cmd[0] = "xz";    cmd[1] = "-cd"; break;
 227    default:          cmd[0] = "cat";   cmd[1] = NULL;  break;
 228    case FP_IMAP:
 229    case FP_MAILDIR:
 230       rv = 0;
 231       goto jleave;
 232    }
 233    rv = run_command(cmd[0], 0, infd, outfd, cmd[1], NULL, NULL);
 234 jleave:
 235    NYD_LEAVE;
 236    return rv;
 237 }
 238
 239 static enum okay
 240 unregister_file(FILE *fp)
 241 {
 242    struct fp **pp, *p;
 243    enum okay rv = OKAY;
 244    NYD_ENTER;
 245
 246    for (pp = &fp_head; (p = *pp) != NULL; pp = &p->link)
 247       if (p->fp == fp) {
 248          if ((p->compressed & FP_MASK) != FP_RAW) /* TODO ;} */
 249             rv = _compress(p);
 250          *pp = p->link;
 251          if (p->realfile != NULL)
 252             free(p->realfile);
 253          free(p);
 254          goto jleave;
 255       }
 256 #ifdef HAVE_DEBUG
 257    panic
 258 #else
 259    alert
 260 #endif
 261       (_("Invalid file pointer"));
 262    rv = STOP;
 263 jleave:
 264    NYD_LEAVE;
 265    return rv;
 266 }
 267
 268 static int
 269 file_pid(FILE *fp)
 270 {
 271    int rv;
 272    struct fp *p;
 273    NYD2_ENTER;
 274
 275    rv = -1;
 276    for (p = fp_head; p; p = p->link)
 277       if (p->fp == fp) {
 278          rv = p->pid;
 279          break;
 280       }
 281    NYD2_LEAVE;
 282    return rv;
 283 }
 284
 285 static void
 286 _sigchld(int signo)
 287 {
 288    int pid, status;
 289    struct child *cp;
 290    NYD_X; /* Signal handler */
 291    UNUSED(signo);
 292
 293    for (;;) {
 294       pid = (int)waitpid((pid_t)-1, &status, WNOHANG);
 295       if (pid <= 0) {
 296          if (pid == -1 && errno == EINTR)
 297             continue;
 298          break;
 299       }
 300       cp = findchild(pid);
 301       if (cp->free)
 302          delchild(cp);
 303       else {
 304          cp->done = 1;
 305          cp->status = status;
 306       }
 307    }
 308 }
 309
 310 static int
 311 wait_command(int pid)
 312 {
 313    int rv = 0;
 314    NYD_ENTER;
 315
 316    if (!wait_child(pid, NULL)) {
 317       if (ok_blook(bsdcompat) || ok_blook(bsdmsgs))
 318          fprintf(stderr, _("Fatal error in process.\n"));
 319       rv = -1;
 320    }
 321    NYD_LEAVE;
 322    return rv;
 323 }
 324
 325 static struct child *
 326 findchild(int pid)
 327 {
 328    struct child **cpp;
 329    NYD_ENTER;
 330
 331    for (cpp = &_popen_child; *cpp != NULL && (*cpp)->pid != pid;
 332          cpp = &(*cpp)->link)
 333       ;
 334    if (*cpp == NULL) {
 335       *cpp = smalloc(sizeof **cpp);
 336       (*cpp)->pid = pid;
 337       (*cpp)->done = (*cpp)->free = 0;
 338       (*cpp)->link = NULL;
 339    }
 340    NYD_LEAVE;
 341    return *cpp;
 342 }
 343
 344 static void
 345 delchild(struct child *cp)
 346 {
 347    struct child **cpp;
 348    NYD_ENTER;
 349
 350    for (cpp = &_popen_child; *cpp != cp; cpp = &(*cpp)->link)
 351       ;
 352    *cpp = cp->link;
 353    free(cp);
 354    NYD_LEAVE;
 355 }
 356
 357 FL void
 358 command_manager_start(void)
 359 {
 360    struct sigaction nact, oact;
 361    NYD_ENTER;
 362
 363    nact.sa_handler = &_sigchld;
 364    sigemptyset(&nact.sa_mask);
 365    nact.sa_flags = 0
 366 #ifdef SA_RESTART
 367          | SA_RESTART
 368 #endif
 369 #ifdef SA_NOCLDSTOP
 370          | SA_NOCLDSTOP
 371 #endif
 372          ;
 373    if (sigaction(SIGCHLD, &nact, &oact) != 0)
 374       panic("Cannot install signal handler for child process management");
 375    NYD_LEAVE;
 376 }
 377
 378 FL FILE *
 379 safe_fopen(char const *file, char const *oflags, int *xflags)
 380 {
 381    int osflags, fd;
 382    FILE *fp = NULL;
 383    NYD2_ENTER; /* (only for Fopen() and once in lex.c) */
 384
 385    if (scan_mode(oflags, &osflags) < 0)
 386       goto jleave;
 387    osflags |= O_CLOEXEC;
 388    if (xflags != NULL)
 389       *xflags = osflags;
 390
 391    if ((fd = open(file, osflags, 0666)) == -1)
 392       goto jleave;
 393    _SET_CLOEXEC(fd);
 394
 395    fp = fdopen(fd, oflags);
 396 jleave:
 397    NYD2_LEAVE;
 398    return fp;
 399 }
 400
 401 FL FILE *
 402 Fopen(char const *file, char const *oflags)
 403 {
 404    FILE *fp;
 405    int osflags;
 406    NYD_ENTER;
 407
 408    if ((fp = safe_fopen(file, oflags, &osflags)) != NULL)
 409       register_file(fp, osflags, 0, 0, FP_RAW, NULL, 0L);
 410    NYD_LEAVE;
 411    return fp;
 412 }
 413
 414 FL FILE *
 415 Fdopen(int fd, char const *oflags)
 416 {
 417    FILE *fp;
 418    int osflags;
 419    NYD_ENTER;
 420
 421    scan_mode(oflags, &osflags);
 422    osflags |= O_CLOEXEC;
 423
 424    if ((fp = fdopen(fd, oflags)) != NULL)
 425       register_file(fp, osflags, 0, 0, FP_RAW, NULL, 0L);
 426    NYD_LEAVE;
 427    return fp;
 428 }
 429
 430 FL int
 431 Fclose(FILE *fp)
 432 {
 433    int i = 0;
 434    NYD_ENTER;
 435
 436    if (unregister_file(fp) == OKAY)
 437       i |= 1;
 438    if (fclose(fp) == 0)
 439       i |= 2;
 440    NYD_LEAVE;
 441    return (i == 3 ? 0 : EOF);
 442 }
 443
 444 FL FILE *
 445 Zopen(char const *file, char const *oflags, int *compression) /* FIXME MESS! */
 446 {
 447    FILE *rv = NULL;
 448    int _compression, osflags, mode, infd;
 449    enum oflags rof;
 450    long offset;
 451    enum protocol p;
 452    NYD_ENTER;
 453
 454    if (compression == NULL)
 455       compression = &_compression;
 456
 457    if (scan_mode(oflags, &osflags) < 0)
 458       goto jleave;
 459    rof = OF_RDWR | OF_UNLINK;
 460    if (osflags & O_APPEND)
 461       rof |= OF_APPEND;
 462    if (osflags == O_RDONLY) {
 463       mode = R_OK;
 464       *compression = FP_READONLY;
 465    } else {
 466       mode = R_OK | W_OK;
 467       *compression = 0;
 468    }
 469
 470    /* TODO ???? */
 471    if ((osflags & O_APPEND) && ((p = which_protocol(file)) == PROTO_IMAP ||
 472          p == PROTO_MAILDIR)) {
 473       *compression |= (p == PROTO_IMAP) ? FP_IMAP : FP_MAILDIR;
 474       osflags = O_RDWR | O_APPEND | O_CREAT;
 475       infd = -1;
 476    } else {
 477       char const *ext;
 478
 479       if ((ext = strrchr(file, '.')) != NULL) {
 480          if (!strcmp(ext, ".gz"))
 481             *compression |= FP_GZIP;
 482          else if (!strcmp(ext, ".xz"))
 483             *compression |= FP_XZ;
 484          else if (!strcmp(ext, ".bz2"))
 485             *compression |= FP_BZIP2;
 486          else
 487             goto jraw;
 488       } else {
 489 jraw:
 490          *compression |= FP_RAW;
 491          rv = Fopen(file, oflags);
 492          goto jleave;
 493       }
 494       if ((infd = open(file, (mode & W_OK) ? O_RDWR : O_RDONLY)) == -1 &&
 495             (!(osflags & O_CREAT) || errno != ENOENT))
 496          goto jleave;
 497    }
 498
 499    if ((rv = Ftmp(NULL, "zopen", rof, 0600)) == NULL) {
 500       perror(_("tmpfile"));
 501       goto jerr;
 502    }
 503    if (infd >= 0 || (*compression & FP_MASK) == FP_IMAP ||
 504          (*compression & FP_MASK) == FP_MAILDIR) {
 505       if (_decompress(*compression, infd, fileno(rv)) < 0) {
 506 jerr:
 507          if (rv != NULL)
 508             Fclose(rv);
 509          rv = NULL;
 510          if (infd >= 0)
 511             close(infd);
 512          goto jleave;
 513       }
 514    } else {
 515       if ((infd = creat(file, 0666)) == -1) {
 516          Fclose(rv);
 517          rv = NULL;
 518          goto jleave;
 519       }
 520    }
 521    if (infd >= 0)
 522       close(infd);
 523    fflush(rv);
 524
 525    if (!(osflags & O_APPEND))
 526       rewind(rv);
 527    if ((offset = ftell(rv)) == -1) {
 528       Fclose(rv);
 529       rv = NULL;
 530       goto jleave;
 531    }
 532    register_file(rv, osflags, 0, 0, *compression, file, offset);
 533 jleave:
 534    NYD_LEAVE;
 535    return rv;
 536 }
 537
 538 FL FILE *
 539 Ftmp(char **fn, char const *prefix, enum oflags oflags, int mode)
 540 {
 541    FILE *fp = NULL;
 542    char *cp_base, *cp;
 543    int fd;
 544    NYD_ENTER;
 545
 546    cp_base =
 547    cp = smalloc(strlen(tempdir) + 1 + sizeof("mail") + strlen(prefix) + 7 +1);
 548    cp = sstpcpy(cp, tempdir);
 549    *cp++ = '/';
 550    cp = sstpcpy(cp, "mail");
 551    if (*prefix) {
 552       *cp++ = '-';
 553       cp = sstpcpy(cp, prefix);
 554    }
 555    /* TODO Ftmp(): unroll our own creation loop with atoi(random()) */
 556    sstpcpy(cp, ".XXXXXX");
 557
 558    hold_all_sigs();
 559 #ifdef HAVE_MKSTEMP
 560    if ((fd = mkstemp(cp_base)) == -1)
 561       goto jfree;
 562    if (mode != (S_IRUSR | S_IWUSR) && fchmod(fd, mode) == -1)
 563       goto jclose;
 564    if (oflags & OF_APPEND) {
 565       int f;
 566
 567       if ((f = fcntl(fd, F_GETFL)) == -1 ||
 568             fcntl(fd, F_SETFL, f | O_APPEND) == -1) {
 569 jclose:
 570          close(fd);
 571          goto junlink;
 572       }
 573    }
 574    if (!(oflags & OF_REGISTER))
 575       fcntl(fd, F_SETFD, FD_CLOEXEC);
 576 #else
 577    if (mktemp(cp_base) == NULL)
 578       goto jfree;
 579    if ((fd = open(cp_base, O_CREAT | O_EXCL | O_RDWR | O_CLOEXEC |
 580          (oflags & OF_APPEND ? O_APPEND : 0), mode)) == -1)
 581       goto junlink;
 582    if (!(oflags & OF_REGISTER))
 583       _SET_CLOEXEC(fd);
 584 #endif
 585
 586    fp = (*((oflags & OF_REGISTER) ? &Fdopen : &fdopen))(fd,
 587          (oflags & OF_RDWR ? "w+" : "w"));
 588    if (fp == NULL || (oflags & OF_UNLINK)) {
 589 junlink:
 590       unlink(cp_base);
 591       goto jfree;
 592    }
 593
 594    if (fn != NULL)
 595       *fn = cp_base;
 596 jleave:
 597    if (fp == NULL || !(oflags & OF_HOLDSIGS))
 598       rele_all_sigs();
 599    NYD_LEAVE;
 600    return fp;
 601 jfree:
 602    if ((cp = cp_base) != NULL)
 603       free(cp);
 604    goto jleave;
 605 }
 606
 607 FL void
 608 Ftmp_release(char **fn)
 609 {
 610    char *cp;
 611    NYD_ENTER;
 612
 613    cp = *fn;
 614    *fn = NULL;
 615    if (cp != NULL) {
 616       unlink(cp);
 617       rele_all_sigs();
 618       free(cp);
 619    }
 620    NYD_LEAVE;
 621 }
 622
 623 FL void
 624 Ftmp_free(char **fn)
 625 {
 626    char *cp;
 627    NYD_ENTER;
 628
 629    cp = *fn;
 630    *fn = NULL;
 631    if (cp != NULL)
 632       free(cp);
 633    NYD_LEAVE;
 634 }
 635
 636 FL bool_t
 637 pipe_cloexec(int fd[2])
 638 {
 639    bool_t rv = FAL0;
 640    NYD_ENTER;
 641
 642 #ifdef HAVE_PIPE2
 643    if (pipe2(fd, O_CLOEXEC) == -1)
 644       goto jleave;
 645 #else
 646    if (pipe(fd) == -1)
 647       goto jleave;
 648    fcntl(fd[0], F_SETFD, FD_CLOEXEC);
 649    fcntl(fd[1], F_SETFD, FD_CLOEXEC);
 650 #endif
 651    rv = TRU1;
 652 jleave:
 653    NYD_LEAVE;
 654    return rv;
 655 }
 656
 657 FL FILE *
 658 Popen(char const *cmd, char const *mode, char const *sh,
 659    char const **env_addon, int newfd1)
 660 {
 661    int p[2], myside, hisside, fd0, fd1, pid;
 662    char mod[2] = {'0', '\0'};
 663    sigset_t nset;
 664    FILE *rv = NULL;
 665    NYD_ENTER;
 666
 667    if (!pipe_cloexec(p))
 668       goto jleave;
 669
 670    if (*mode == 'r') {
 671       myside = p[READ];
 672       fd0 = -1;
 673       hisside = fd1 = p[WRITE];
 674       mod[0] = *mode;
 675    } else if (*mode == 'W') {
 676       myside = p[WRITE];
 677       hisside = fd0 = p[READ];
 678       fd1 = newfd1;
 679       mod[0] = 'w';
 680    } else {
 681       myside = p[WRITE];
 682       hisside = fd0 = p[READ];
 683       fd1 = -1;
 684       mod[0] = 'w';
 685    }
 686    sigemptyset(&nset);
 687    if (sh == NULL) {
 688       pid = start_command(cmd, &nset, fd0, fd1, NULL, NULL, NULL, env_addon);
 689    } else {
 690       pid = start_command(sh, &nset, fd0, fd1, "-c", cmd, NULL, env_addon);
 691    }
 692    if (pid < 0) {
 693       close(p[READ]);
 694       close(p[WRITE]);
 695       goto jleave;
 696    }
 697    close(hisside);
 698    if ((rv = fdopen(myside, mod)) != NULL)
 699       register_file(rv, 0, 1, pid, FP_RAW, NULL, 0L);
 700 jleave:
 701    NYD_LEAVE;
 702    return rv;
 703 }
 704
 705 FL bool_t
 706 Pclose(FILE *ptr, bool_t dowait)
 707 {
 708    sigset_t nset, oset;
 709    int pid;
 710    bool_t rv = FAL0;
 711    NYD_ENTER;
 712
 713    pid = file_pid(ptr);
 714    if (pid < 0)
 715       goto jleave;
 716    unregister_file(ptr);
 717    fclose(ptr);
 718    if (dowait) {
 719       sigemptyset(&nset);
 720       sigaddset(&nset, SIGINT);
 721       sigaddset(&nset, SIGHUP);
 722       sigprocmask(SIG_BLOCK, &nset, &oset);
 723       rv = wait_child(pid, NULL);
 724       sigprocmask(SIG_SETMASK, &oset, NULL);
 725    } else {
 726       free_child(pid);
 727       rv = TRU1;
 728    }
 729 jleave:
 730    NYD_LEAVE;
 731    return rv;
 732 }
 733
 734 FL void
 735 close_all_files(void)
 736 {
 737    NYD_ENTER;
 738    while (fp_head != NULL)
 739       if (fp_head->pipe)
 740          Pclose(fp_head->fp, TRU1);
 741       else
 742          Fclose(fp_head->fp);
 743    NYD_LEAVE;
 744 }
 745
 746 FL int
 747 run_command(char const *cmd, sigset_t *mask, int infd, int outfd,
 748    char const *a0, char const *a1, char const *a2)
 749 {
 750    int rv;
 751    NYD_ENTER;
 752
 753    if ((rv = start_command(cmd, mask, infd, outfd, a0, a1, a2, NULL)) < 0)
 754       rv = -1;
 755    else
 756       rv = wait_command(rv);
 757    NYD_LEAVE;
 758    return rv;
 759 }
 760
 761 FL int
 762 start_command(char const *cmd, sigset_t *mask, int infd, int outfd,
 763    char const *a0, char const *a1, char const *a2,
 764    char const **env_addon)
 765 {
 766    int rv;
 767    NYD_ENTER;
 768
 769    if ((rv = fork()) == -1) {
 770       perror("fork");
 771       rv = -1;
 772    } else if (rv == 0) {
 773       char *argv[128];
 774       int i;
 775
 776       if (env_addon != NULL) { /* TODO env_addon; should have struct child */
 777          extern char **environ;
 778          size_t ei, ei_orig, ai, ai_orig;
 779          char **env;
 780
 781          /* TODO note we don't check the POSIX limit:
 782           * the total space used to store the environment and the arguments to
 783           * the process is limited to {ARG_MAX} bytes */
 784          for (ei = 0; environ[ei] != NULL; ++ei)
 785             ;
 786          ei_orig = ei;
 787          for (ai = 0; env_addon[ai] != NULL; ++ai)
 788             ;
 789          ai_orig = ai;
 790          env = ac_alloc(sizeof(*env) * (ei + ai +1));
 791          memcpy(env, environ, sizeof(*env) * ei);
 792
 793          /* Replace all those keys that yet exist */
 794          while (ai-- > 0) {
 795             char const *ee, *kvs;
 796             size_t kl;
 797
 798             ee = env_addon[ai];
 799             kvs = strchr(ee, '=');
 800             assert(kvs != NULL);
 801             kl = PTR2SIZE(kvs - ee);
 802             assert(kl > 0);
 803             for (ei = ei_orig; ei-- > 0;) {
 804                char const *ekvs = strchr(env[ei], '=');
 805                if (ekvs != NULL && kl == PTR2SIZE(ekvs - env[ei]) &&
 806                      !memcmp(ee, env[ei], kl)) {
 807                   env[ei] = UNCONST(ee);
 808                   env_addon[ai] = NULL;
 809                   break;
 810                }
 811             }
 812          }
 813
 814          /* And append the rest */
 815          for (ei = ei_orig, ai = ai_orig; ai-- > 0;)
 816             if (env_addon[ai] != NULL)
 817                env[ei++] = UNCONST(env_addon[ai]);
 818
 819          env[ei] = NULL;
 820          environ = env;
 821       }
 822
 823       i = getrawlist(cmd, strlen(cmd), argv, NELEM(argv), 0);
 824
 825       if ((argv[i++] = UNCONST(a0)) != NULL &&
 826             (argv[i++] = UNCONST(a1)) != NULL &&
 827             (argv[i++] = UNCONST(a2)) != NULL)
 828          argv[i] = NULL;
 829       prepare_child(mask, infd, outfd);
 830       execvp(argv[0], argv);
 831       perror(argv[0]);
 832       _exit(1);
 833    }
 834    NYD_LEAVE;
 835    return rv;
 836 }
 837
 838 FL void
 839 prepare_child(sigset_t *nset, int infd, int outfd)
 840 {
 841    int i;
 842    sigset_t fset;
 843    NYD_ENTER;
 844
 845    /* All file descriptors other than 0, 1, and 2 are supposed to be cloexec */
 846    if (infd >= 0)
 847       dup2(infd, 0);
 848    if (outfd >= 0)
 849       dup2(outfd, 1);
 850
 851    if (nset) {
 852       for (i = 1; i < NSIG; ++i)
 853          if (sigismember(nset, i))
 854             safe_signal(i, SIG_IGN);
 855       if (!sigismember(nset, SIGINT))
 856          safe_signal(SIGINT, SIG_DFL);
 857    }
 858
 859    sigemptyset(&fset);
 860    sigprocmask(SIG_SETMASK, &fset, NULL);
 861    NYD_LEAVE;
 862 }
 863
 864 FL void
 865 free_child(int pid)
 866 {
 867    sigset_t nset, oset;
 868    struct child *cp;
 869    NYD_ENTER;
 870
 871    sigemptyset(&nset);
 872    sigaddset(&nset, SIGCHLD);
 873    sigprocmask(SIG_BLOCK, &nset, &oset);
 874
 875    cp = findchild(pid);
 876    if (cp->done)
 877       delchild(cp);
 878    else
 879       cp->free = 1;
 880
 881    sigprocmask(SIG_SETMASK, &oset, NULL);
 882    NYD_LEAVE;
 883 }
 884
 885 FL bool_t
 886 wait_child(int pid, int *wait_status)
 887 {
 888    sigset_t nset, oset;
 889    struct child *cp;
 890    int ws;
 891    bool_t rv;
 892    NYD_ENTER;
 893
 894    sigemptyset(&nset);
 895    sigaddset(&nset, SIGCHLD);
 896    sigprocmask(SIG_BLOCK, &nset, &oset);
 897
 898    cp = findchild(pid);
 899    while (!cp->done)
 900       sigsuspend(&oset);
 901    ws = cp->status;
 902    delchild(cp);
 903
 904    sigprocmask(SIG_SETMASK, &oset, NULL);
 905
 906    if (wait_status != NULL)
 907       *wait_status = ws;
 908    rv = (WIFEXITED(ws) && WEXITSTATUS(ws) == 0);
 909    NYD_LEAVE;
 910    return rv;
 911 }
 912
 913 #ifdef _OUR_CLOEXEC
 914 # undef O_CLOEXEC
 915 # undef _OUR_CLOEXEC
 916 #endif
 917 #undef _SET_CLOEXEC
 918
 919 /* s-it-mode */