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)  fcntl((FD), F_SETFD, FD_CLOEXEC)
  55 #else
  56 # define _SET_CLOEXEC(FD)
  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 static int           wait_command(int pid);
  98 static struct child *findchild(int pid);
  99 static void          delchild(struct child *cp);
 100
 101 static int
 102 scan_mode(char const *mode, int *omode)
 103 {
 104    static struct {
 105       char const  mode[4];
 106       int         omode;
 107    } const maps[] = {
 108       {"r", O_RDONLY},
 109       {"w", O_WRONLY | O_CREAT | O_TRUNC},
 110       {"wx", O_WRONLY | O_CREAT | O_EXCL},
 111       {"a", O_WRONLY | O_APPEND | O_CREAT},
 112       {"a+", O_RDWR | O_APPEND},
 113       {"r+", O_RDWR},
 114       {"w+", O_RDWR | O_CREAT | O_EXCL}
 115    };
 116
 117    int i;
 118    NYD_ENTER;
 119
 120    for (i = 0; UICMP(z, i, <, NELEM(maps)); ++i)
 121       if (!strcmp(maps[i].mode, mode)) {
 122          *omode = maps[i].omode;
 123          i = 0;
 124          goto jleave;
 125       }
 126
 127    fprintf(stderr, tr(152, "Internal error: bad stdio open mode %s\n"), mode);
 128    errno = EINVAL;
 129    *omode = 0; /* (silence CC) */
 130    i = -1;
 131 jleave:
 132    NYD_LEAVE;
 133    return i;
 134 }
 135
 136 static void
 137 register_file(FILE *fp, int omode, int ispipe, int pid, int compressed,
 138    char const *realfile, long offset)
 139 {
 140    struct fp *fpp;
 141    NYD_ENTER;
 142
 143    fpp = smalloc(sizeof *fpp);
 144    fpp->fp = fp;
 145    fpp->omode = omode;
 146    fpp->pipe = ispipe;
 147    fpp->pid = pid;
 148    fpp->link = fp_head;
 149    fpp->compressed = compressed;
 150    fpp->realfile = realfile ? sstrdup(realfile) : NULL;
 151    fpp->offset = offset;
 152    fp_head = fpp;
 153    NYD_LEAVE;
 154 }
 155
 156 static enum okay
 157 _compress(struct fp *fpp)
 158 {
 159    char const *cmd[2];
 160    int outfd;
 161    enum okay rv;
 162    NYD_ENTER;
 163
 164    if (fpp->omode == O_RDONLY) {
 165       rv = OKAY;
 166       goto jleave;
 167    }
 168    rv = STOP;
 169
 170    fflush(fpp->fp);
 171    clearerr(fpp->fp);
 172    if (fseek(fpp->fp, fpp->offset, SEEK_SET) < 0)
 173       goto jleave;
 174
 175 #ifdef HAVE_IMAP
 176    if ((fpp->compressed & FP_MASK) == FP_IMAP) {
 177       rv = imap_append(fpp->realfile, fpp->fp);
 178       goto jleave;
 179    }
 180 #endif
 181    if ((fpp->compressed & FP_MASK) == FP_MAILDIR) {
 182       rv = maildir_append(fpp->realfile, fpp->fp);
 183       goto jleave;
 184    }
 185
 186    outfd = open(fpp->realfile, (fpp->omode | O_CREAT) & ~O_EXCL, 0666);
 187    if (outfd < 0) {
 188       fprintf(stderr, "Fatal: cannot create ");
 189       perror(fpp->realfile);
 190       goto jleave;
 191    }
 192    if ((fpp->omode & O_APPEND) == 0)
 193       ftruncate(outfd, 0);
 194    switch (fpp->compressed & FP_MASK) {
 195    case FP_GZIP:
 196       cmd[0] = "gzip";  cmd[1] = "-c"; break;
 197    case FP_BZIP2:
 198       cmd[0] = "bzip2"; cmd[1] = "-c"; break;
 199    case FP_XZ:
 200       cmd[0] = "xz";    cmd[1] = "-c"; break;
 201    default:
 202       cmd[0] = "cat";   cmd[1] = NULL; break;
 203    }
 204    if (run_command(cmd[0], 0, fileno(fpp->fp), outfd, cmd[1], NULL, NULL) >= 0)
 205       rv = OKAY;
 206    close(outfd);
 207 jleave:
 208    NYD_LEAVE;
 209    return rv;
 210 }
 211
 212 static int
 213 _decompress(int compression, int infd, int outfd)
 214 {
 215    char const *cmd[2];
 216    int rv;
 217    NYD_ENTER;
 218
 219    switch (compression & FP_MASK) {
 220    case FP_GZIP:     cmd[0] = "gzip";  cmd[1] = "-cd"; break;
 221    case FP_BZIP2:    cmd[0] = "bzip2"; cmd[1] = "-cd"; break;
 222    case FP_XZ:       cmd[0] = "xz";    cmd[1] = "-cd"; break;
 223    default:          cmd[0] = "cat";   cmd[1] = NULL;  break;
 224    case FP_IMAP:
 225    case FP_MAILDIR:
 226       rv = 0;
 227       goto jleave;
 228    }
 229    rv = run_command(cmd[0], 0, infd, outfd, cmd[1], NULL, NULL);
 230 jleave:
 231    NYD_LEAVE;
 232    return rv;
 233 }
 234
 235 static enum okay
 236 unregister_file(FILE *fp)
 237 {
 238    struct fp **pp, *p;
 239    enum okay rv = OKAY;
 240    NYD_ENTER;
 241
 242    for (pp = &fp_head; (p = *pp) != NULL; pp = &p->link)
 243       if (p->fp == fp) {
 244          if ((p->compressed & FP_MASK) != FP_RAW) /* TODO ;} */
 245             rv = _compress(p);
 246          *pp = p->link;
 247          free(p);
 248          goto jleave;
 249       }
 250    rv = STOP;
 251    panic(tr(153, "Invalid file pointer"));
 252 jleave:
 253    NYD_LEAVE;
 254    return rv;
 255 }
 256
 257 static int
 258 file_pid(FILE *fp)
 259 {
 260    int rv;
 261    struct fp *p;
 262    NYD_ENTER;
 263
 264    rv = -1;
 265    for (p = fp_head; p; p = p->link)
 266       if (p->fp == fp) {
 267          rv = p->pid;
 268          break;
 269       }
 270    NYD_LEAVE;
 271    return rv;
 272 }
 273
 274 static int
 275 wait_command(int pid)
 276 {
 277    int rv = 0;
 278    NYD_ENTER;
 279
 280    if (!wait_child(pid, NULL)) {
 281       if (ok_blook(bsdcompat) || ok_blook(bsdmsgs))
 282          fprintf(stderr, tr(154, "Fatal error in process.\n"));
 283       rv = -1;
 284    }
 285    NYD_LEAVE;
 286    return rv;
 287 }
 288
 289 static struct child *
 290 findchild(int pid)
 291 {
 292    struct child **cpp;
 293    NYD_ENTER;
 294
 295    for (cpp = &_popen_child; *cpp != NULL && (*cpp)->pid != pid;
 296          cpp = &(*cpp)->link)
 297       ;
 298    if (*cpp == NULL) {
 299       *cpp = smalloc(sizeof **cpp);
 300       (*cpp)->pid = pid;
 301       (*cpp)->done = (*cpp)->free = 0;
 302       (*cpp)->link = NULL;
 303    }
 304    NYD_LEAVE;
 305    return *cpp;
 306 }
 307
 308 static void
 309 delchild(struct child *cp)
 310 {
 311    struct child **cpp;
 312    NYD_ENTER;
 313
 314    for (cpp = &_popen_child; *cpp != cp; cpp = &(*cpp)->link)
 315       ;
 316    *cpp = cp->link;
 317    free(cp);
 318    NYD_LEAVE;
 319 }
 320
 321 FL FILE *
 322 safe_fopen(char const *file, char const *oflags, int *xflags)
 323 {
 324    int osflags, fd;
 325    FILE *fp = NULL;
 326    NYD_ENTER;
 327
 328    if (scan_mode(oflags, &osflags) < 0)
 329       goto jleave;
 330    osflags |= O_CLOEXEC;
 331    if (xflags != NULL)
 332       *xflags = osflags;
 333
 334    if ((fd = open(file, osflags, 0666)) < 0)
 335       goto jleave;
 336    _SET_CLOEXEC(fd);
 337
 338    fp = fdopen(fd, oflags);
 339 jleave:
 340    NYD_LEAVE;
 341    return fp;
 342 }
 343
 344 FL FILE *
 345 Fopen(char const *file, char const *oflags)
 346 {
 347    FILE *fp;
 348    int osflags;
 349    NYD_ENTER;
 350
 351    if ((fp = safe_fopen(file, oflags, &osflags)) != NULL)
 352       register_file(fp, osflags, 0, 0, FP_RAW, NULL, 0L);
 353    NYD_LEAVE;
 354    return fp;
 355 }
 356
 357 FL FILE *
 358 Fdopen(int fd, char const *oflags)
 359 {
 360    FILE *fp;
 361    int osflags;
 362    NYD_ENTER;
 363
 364    scan_mode(oflags, &osflags);
 365    osflags |= O_CLOEXEC;
 366
 367    if ((fp = fdopen(fd, oflags)) != NULL)
 368       register_file(fp, osflags, 0, 0, FP_RAW, NULL, 0L);
 369    NYD_LEAVE;
 370    return fp;
 371 }
 372
 373 FL int
 374 Fclose(FILE *fp)
 375 {
 376    int i = 0;
 377    NYD_ENTER;
 378
 379    if (unregister_file(fp) == OKAY)
 380       i |= 1;
 381    if (fclose(fp) == 0)
 382       i |= 2;
 383    NYD_LEAVE;
 384    return i == 3 ? 0 : EOF;
 385 }
 386
 387 FL FILE *
 388 Zopen(char const *file, char const *oflags, int *compression) /* FIXME MESS! */
 389 {
 390    FILE *rv = NULL;
 391    int _compression, osflags, mode, infd;
 392    enum oflags rof;
 393    long offset;
 394    enum protocol p;
 395    NYD_ENTER;
 396
 397    if (compression == NULL)
 398       compression = &_compression;
 399
 400    if (scan_mode(oflags, &osflags) < 0)
 401       goto jleave;
 402    rof = OF_RDWR | OF_UNLINK;
 403    if (osflags & O_APPEND)
 404       rof |= OF_APPEND;
 405    if (osflags == O_RDONLY) {
 406       mode = R_OK;
 407       *compression = FP_READONLY;
 408    } else {
 409       mode = R_OK | W_OK;
 410       *compression = 0;
 411    }
 412
 413    /* TODO ???? */
 414    if ((osflags & O_APPEND) && ((p = which_protocol(file)) == PROTO_IMAP ||
 415          p == PROTO_MAILDIR)) {
 416       *compression |= (p == PROTO_IMAP) ? FP_IMAP : FP_MAILDIR;
 417       osflags = O_RDWR | O_APPEND | O_CREAT;
 418       infd = -1;
 419    } else {
 420       char const *ext;
 421
 422       if ((ext = strrchr(file, '.')) != NULL) {
 423          if (!strcmp(ext, ".gz"))
 424             *compression |= FP_GZIP;
 425          else if (!strcmp(ext, ".xz"))
 426             *compression |= FP_XZ;
 427          else if (!strcmp(ext, ".bz2"))
 428             *compression |= FP_BZIP2;
 429          else
 430             goto jraw;
 431       } else {
 432 jraw:
 433          *compression |= FP_RAW;
 434          rv = Fopen(file, oflags);
 435          goto jleave;
 436       }
 437       if ((infd = open(file, (mode & W_OK) ? O_RDWR : O_RDONLY)) == -1 &&
 438             (!(osflags & O_CREAT) || errno != ENOENT))
 439          goto jleave;
 440    }
 441
 442    if ((rv = Ftmp(NULL, "zopen", rof, 0600)) == NULL) {
 443       perror(tr(167, "tmpfile"));
 444       goto jerr;
 445    }
 446    if (infd >= 0 || (*compression & FP_MASK) == FP_IMAP ||
 447          (*compression & FP_MASK) == FP_MAILDIR) {
 448       if (_decompress(*compression, infd, fileno(rv)) < 0) {
 449 jerr:
 450          if (rv != NULL)
 451             Fclose(rv);
 452          rv = NULL;
 453          if (infd >= 0)
 454             close(infd);
 455          goto jleave;
 456       }
 457    } else {
 458       if ((infd = creat(file, 0666)) == -1) {
 459          Fclose(rv);
 460          rv = NULL;
 461          goto jleave;
 462       }
 463    }
 464    if (infd >= 0)
 465       close(infd);
 466    fflush(rv);
 467
 468    if (!(osflags & O_APPEND))
 469       rewind(rv);
 470    if ((offset = ftell(rv)) == -1) {
 471       Fclose(rv);
 472       rv = NULL;
 473       goto jleave;
 474    }
 475    register_file(rv, osflags, 0, 0, *compression, file, offset);
 476 jleave:
 477    NYD_LEAVE;
 478    return rv;
 479 }
 480
 481 FL FILE *
 482 Ftmp(char **fn, char const *prefix, enum oflags oflags, int mode)
 483 {
 484    FILE *fp = NULL;
 485    char *cp_base, *cp;
 486    int fd;
 487    NYD_ENTER;
 488
 489    cp_base =
 490    cp = smalloc(strlen(tempdir) + 1 + sizeof("mail") + strlen(prefix) + 7 +1);
 491    cp = sstpcpy(cp, tempdir);
 492    *cp++ = '/';
 493    cp = sstpcpy(cp, "mail");
 494    if (*prefix) {
 495       *cp++ = '-';
 496       cp = sstpcpy(cp, prefix);
 497    }
 498    /* TODO Ftmp(): unroll our own creation loop with atoi(random()) */
 499    sstpcpy(cp, ".XXXXXX");
 500
 501    hold_all_sigs();
 502 #ifdef HAVE_MKSTEMP
 503    if ((fd = mkstemp(cp_base)) == -1)
 504       goto jfree;
 505    if (mode != (S_IRUSR | S_IWUSR) && fchmod(fd, mode) == -1)
 506       goto jclose;
 507    if (oflags & OF_APPEND) {
 508       int f;
 509
 510       if ((f = fcntl(fd, F_GETFL)) == -1 ||
 511             fcntl(fd, F_SETFL, f | O_APPEND) == -1) {
 512 jclose:
 513          close(fd);
 514          goto junlink;
 515       }
 516    }
 517    if (!(oflags & OF_REGISTER))
 518       fcntl(fd, F_SETFD, FD_CLOEXEC);
 519 #else
 520    if (mktemp(cp_base) == NULL)
 521       goto jfree;
 522    if ((fd = open(cp_base, O_CREAT | O_EXCL | O_RDWR | O_CLOEXEC |
 523          (oflags & OF_APPEND ? O_APPEND : 0), mode)) < 0)
 524       goto junlink;
 525 #endif
 526
 527    fp = (*((oflags & OF_REGISTER) ? &Fdopen : &fdopen))(fd,
 528          (oflags & OF_RDWR ? "w+" : "w"));
 529    if (fp == NULL || (oflags & OF_UNLINK)) {
 530 junlink:
 531       unlink(cp_base);
 532       goto jfree;
 533    }
 534
 535    if (fn != NULL)
 536       *fn = cp_base;
 537 jleave:
 538    if (fp == NULL || !(oflags & OF_HOLDSIGS))
 539       rele_all_sigs();
 540    NYD_LEAVE;
 541    return fp;
 542 jfree:
 543    if ((cp = cp_base) != NULL)
 544       free(cp);
 545    goto jleave;
 546 }
 547
 548 FL void
 549 Ftmp_release(char **fn)
 550 {
 551    char *cp;
 552    NYD_ENTER;
 553
 554    cp = *fn;
 555    *fn = NULL;
 556    if (cp != NULL) {
 557       unlink(cp);
 558       rele_all_sigs();
 559       free(cp);
 560    }
 561    NYD_LEAVE;
 562 }
 563
 564 FL void
 565 Ftmp_free(char **fn)
 566 {
 567    char *cp;
 568    NYD_ENTER;
 569
 570    cp = *fn;
 571    *fn = NULL;
 572    if (cp != NULL)
 573       free(cp);
 574    NYD_LEAVE;
 575 }
 576
 577 FL bool_t
 578 pipe_cloexec(int fd[2])
 579 {
 580    bool_t rv = FAL0;
 581    NYD_ENTER;
 582
 583    if (pipe(fd) < 0)
 584       goto jleave;
 585    fcntl(fd[0], F_SETFD, FD_CLOEXEC);
 586    fcntl(fd[1], F_SETFD, FD_CLOEXEC);
 587    rv = TRU1;
 588 jleave:
 589    NYD_LEAVE;
 590    return rv;
 591 }
 592
 593 FL FILE *
 594 Popen(char const *cmd, char const *mode, char const *sh, int newfd1)
 595 {
 596    int p[2], myside, hisside, fd0, fd1, pid;
 597    char mod[2] = { '0', '\0' };
 598    sigset_t nset;
 599    FILE *rv = NULL;
 600    NYD_ENTER;
 601
 602    if (!pipe_cloexec(p))
 603       goto jleave;
 604
 605    if (*mode == 'r') {
 606       myside = p[READ];
 607       fd0 = -1;
 608       hisside = fd1 = p[WRITE];
 609       mod[0] = *mode;
 610    } else if (*mode == 'W') {
 611       myside = p[WRITE];
 612       hisside = fd0 = p[READ];
 613       fd1 = newfd1;
 614       mod[0] = 'w';
 615    } else {
 616       myside = p[WRITE];
 617       hisside = fd0 = p[READ];
 618       fd1 = -1;
 619       mod[0] = 'w';
 620    }
 621    sigemptyset(&nset);
 622    if (sh == NULL) {
 623       pid = start_command(cmd, &nset, fd0, fd1, NULL, NULL, NULL);
 624    } else {
 625       pid = start_command(sh, &nset, fd0, fd1, "-c", cmd, NULL);
 626    }
 627    if (pid < 0) {
 628       close(p[READ]);
 629       close(p[WRITE]);
 630       goto jleave;
 631    }
 632    close(hisside);
 633    if ((rv = fdopen(myside, mod)) != NULL)
 634       register_file(rv, 0, 1, pid, FP_RAW, NULL, 0L);
 635 jleave:
 636    NYD_LEAVE;
 637    return rv;
 638 }
 639
 640 FL bool_t
 641 Pclose(FILE *ptr, bool_t dowait)
 642 {
 643    sigset_t nset, oset;
 644    int pid;
 645    bool_t rv = FAL0;
 646    NYD_ENTER;
 647
 648    pid = file_pid(ptr);
 649    if (pid < 0)
 650       goto jleave;
 651    unregister_file(ptr);
 652    fclose(ptr);
 653    if (dowait) {
 654       sigemptyset(&nset);
 655       sigaddset(&nset, SIGINT);
 656       sigaddset(&nset, SIGHUP);
 657       sigprocmask(SIG_BLOCK, &nset, &oset);
 658       rv = wait_child(pid, NULL);
 659       sigprocmask(SIG_SETMASK, &oset, NULL);
 660    } else {
 661       free_child(pid);
 662       rv = TRU1;
 663    }
 664 jleave:
 665    NYD_LEAVE;
 666    return rv;
 667 }
 668
 669 FL void
 670 close_all_files(void)
 671 {
 672    NYD_ENTER;
 673    while (fp_head != NULL)
 674       if (fp_head->pipe)
 675          Pclose(fp_head->fp, TRU1);
 676       else
 677          Fclose(fp_head->fp);
 678    NYD_LEAVE;
 679 }
 680
 681 FL int
 682 run_command(char const *cmd, sigset_t *mask, int infd, int outfd,
 683    char const *a0, char const *a1, char const *a2)
 684 {
 685    int rv;
 686    NYD_ENTER;
 687
 688    if ((rv = start_command(cmd, mask, infd, outfd, a0, a1, a2)) < 0)
 689       rv = -1;
 690    else
 691       rv = wait_command(rv);
 692    NYD_LEAVE;
 693    return rv;
 694 }
 695
 696 FL int
 697 start_command(char const *cmd, sigset_t *mask, int infd, int outfd,
 698    char const *a0, char const *a1, char const *a2)
 699 {
 700    int rv;
 701    NYD_ENTER;
 702
 703    if ((rv = fork()) < 0) {
 704       perror("fork");
 705       rv = -1;
 706    } else if (rv == 0) {
 707       char *argv[100];
 708       int i = getrawlist(cmd, strlen(cmd), argv, NELEM(argv), 0);
 709
 710       if ((argv[i++] = UNCONST(a0)) != NULL &&
 711           (argv[i++] = UNCONST(a1)) != NULL &&
 712           (argv[i++] = UNCONST(a2)) != NULL)
 713          argv[i] = NULL;
 714       prepare_child(mask, infd, outfd);
 715       execvp(argv[0], argv);
 716       perror(argv[0]);
 717       _exit(1);
 718    }
 719    NYD_LEAVE;
 720    return rv;
 721 }
 722
 723 FL void
 724 prepare_child(sigset_t *nset, int infd, int outfd)
 725 {
 726    int i;
 727    sigset_t fset;
 728    NYD_ENTER;
 729
 730    /* All file descriptors other than 0, 1, and 2 are supposed to be cloexec */
 731    if (infd >= 0)
 732       dup2(infd, 0);
 733    if (outfd >= 0)
 734       dup2(outfd, 1);
 735
 736    if (nset) {
 737       for (i = 1; i < NSIG; ++i)
 738          if (sigismember(nset, i))
 739             safe_signal(i, SIG_IGN);
 740       if (!sigismember(nset, SIGINT))
 741          safe_signal(SIGINT, SIG_DFL);
 742    }
 743
 744    sigemptyset(&fset);
 745    sigprocmask(SIG_SETMASK, &fset, NULL);
 746    NYD_LEAVE;
 747 }
 748
 749 FL void
 750 sigchild(int signo)
 751 {
 752    int pid, status;
 753    struct child *cp;
 754    NYD_X; /* Signal handler */
 755    UNUSED(signo);
 756
 757 jagain:
 758    while ((pid = waitpid(-1, &status, WNOHANG)) > 0) {
 759       cp = findchild(pid);
 760       if (cp->free)
 761          delchild(cp);
 762       else {
 763          cp->done = 1;
 764          cp->status = status;
 765       }
 766    }
 767    if (pid == -1 && errno == EINTR)
 768       goto jagain;
 769 }
 770
 771 FL void
 772 free_child(int pid)
 773 {
 774    sigset_t nset, oset;
 775    struct child *cp;
 776    NYD_ENTER;
 777
 778    sigemptyset(&nset);
 779    sigaddset(&nset, SIGCHLD);
 780    sigprocmask(SIG_BLOCK, &nset, &oset);
 781
 782    cp = findchild(pid);
 783    if (cp->done)
 784       delchild(cp);
 785    else
 786       cp->free = 1;
 787
 788    sigprocmask(SIG_SETMASK, &oset, NULL);
 789    NYD_LEAVE;
 790 }
 791
 792 FL bool_t
 793 wait_child(int pid, int *wait_status)
 794 {
 795    sigset_t nset, oset;
 796    struct child *cp;
 797    int ws;
 798    bool_t rv;
 799    NYD_ENTER;
 800
 801    sigemptyset(&nset);
 802    sigaddset(&nset, SIGCHLD);
 803    sigprocmask(SIG_BLOCK, &nset, &oset);
 804
 805    cp = findchild(pid);
 806    while (!cp->done)
 807       sigsuspend(&oset);
 808    ws = cp->status;
 809    delchild(cp);
 810
 811    sigprocmask(SIG_SETMASK, &oset, NULL);
 812
 813    if (wait_status != NULL)
 814       *wait_status = ws;
 815    rv = (WIFEXITED(ws) && WEXITSTATUS(ws) == 0);
 816    NYD_LEAVE;
 817    return rv;
 818 }
 819
 820 #ifdef _OUR_CLOEXEC
 821 # undef O_CLOEXEC
 822 # undef _OUR_CLOEXEC
 823 #endif
 824 #undef _SET_CLOEXEC
 825
 826 /* vim:set fenc=utf-8:s-it-mode */