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 - 2015 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. Neither the name of the University nor the names of its contributors
  20  *    may be used to endorse or promote products derived from this software
  21  *    without specific prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33  * SUCH DAMAGE.
  34  */
  35 #undef n_FILE
  36 #define n_FILE popen
  37
  38 #ifndef HAVE_AMALGAMATION
  39 # include "nail.h"
  40 #endif
  41
  42 #include <sys/wait.h>
  43
  44 #define READ               0
  45 #define WRITE              1
  46
  47 struct fp {
  48    FILE        *fp;
  49    struct fp   *link;
  50    char        *realfile;
  51    char        *save_cmd;
  52    long        offset;
  53    int         omode;
  54    int         pipe;
  55    int         pid;
  56    enum {
  57       FP_RAW      = 0,
  58       FP_GZIP     = 1<<0,
  59       FP_XZ       = 1<<1,
  60       FP_BZIP2    = 1<<2,
  61       FP_IMAP     = 1<<3,
  62       FP_MAILDIR  = 1<<4,
  63       FP_HOOK     = 1<<5,
  64       FP_MASK     = (1<<6) - 1
  65    }           flags;
  66 };
  67
  68 struct child {
  69    int         pid;
  70    char        done;
  71    char        free;
  72    int         status;
  73    struct child *link;
  74 };
  75
  76 static struct fp     *fp_head;
  77 static struct child  *_popen_child;
  78
  79 static int           scan_mode(char const *mode, int *omode);
  80 static void          register_file(FILE *fp, int omode, int ispipe, int pid,
  81                         int flags, char const *realfile, long offset,
  82                         char const *save_cmd);
  83 static enum okay     _file_save(struct fp *fpp);
  84 static int           _file_load(int flags, int infd, int outfd,
  85                         char const *load_cmd);
  86 static enum okay     unregister_file(FILE *fp);
  87 static int           file_pid(FILE *fp);
  88
  89 /* Handle SIGCHLD */
  90 static void          _sigchld(int signo);
  91
  92 static int           wait_command(int pid);
  93 static struct child *_findchild(int pid, bool_t create);
  94 static void          _delchild(struct child *cp);
  95
  96 static int
  97 scan_mode(char const *mode, int *omode)
  98 {
  99    static struct {
 100       char const  mode[4];
 101       int         omode;
 102    } const maps[] = {
 103       {"r", O_RDONLY},
 104       {"w", O_WRONLY | O_CREAT | O_TRUNC},
 105       {"wx", O_WRONLY | O_CREAT | O_EXCL},
 106       {"a", O_WRONLY | O_APPEND | O_CREAT},
 107       {"a+", O_RDWR | O_APPEND},
 108       {"r+", O_RDWR},
 109       {"w+", O_RDWR | O_CREAT | O_EXCL}
 110    };
 111
 112    int i;
 113    NYD2_ENTER;
 114
 115    for (i = 0; UICMP(z, i, <, NELEM(maps)); ++i)
 116       if (!strcmp(maps[i].mode, mode)) {
 117          *omode = maps[i].omode;
 118          i = 0;
 119          goto jleave;
 120       }
 121
 122    n_alert(_("Internal error: bad stdio open mode %s"), mode);
 123    errno = EINVAL;
 124    *omode = 0; /* (silence CC) */
 125    i = -1;
 126 jleave:
 127    NYD2_LEAVE;
 128    return i;
 129 }
 130
 131 static void
 132 register_file(FILE *fp, int omode, int ispipe, int pid, int flags,
 133    char const *realfile, long offset, char const *save_cmd)
 134 {
 135    struct fp *fpp;
 136    NYD_ENTER;
 137
 138    fpp = smalloc(sizeof *fpp);
 139    fpp->fp = fp;
 140    fpp->omode = omode;
 141    fpp->pipe = ispipe;
 142    fpp->pid = pid;
 143    fpp->link = fp_head;
 144    fpp->flags = flags;
 145    fpp->realfile = (realfile != NULL) ? sstrdup(realfile) : NULL;
 146    fpp->save_cmd = (save_cmd != NULL) ? sstrdup(save_cmd) : NULL;
 147    fpp->offset = offset;
 148    fp_head = fpp;
 149    NYD_LEAVE;
 150 }
 151
 152 static enum okay
 153 _file_save(struct fp *fpp)
 154 {
 155    char const *cmd[3];
 156    int outfd;
 157    enum okay rv;
 158    NYD_ENTER;
 159
 160    if (fpp->omode == O_RDONLY) {
 161       rv = OKAY;
 162       goto jleave;
 163    }
 164    rv = STOP;
 165
 166    fflush(fpp->fp);
 167    clearerr(fpp->fp);
 168    if (fseek(fpp->fp, fpp->offset, SEEK_SET) == -1)
 169       goto jleave;
 170
 171 #ifdef HAVE_IMAP
 172    if ((fpp->flags & FP_MASK) == FP_IMAP) {
 173       rv = imap_append(fpp->realfile, fpp->fp);
 174       goto jleave;
 175    }
 176 #endif
 177    if ((fpp->flags & FP_MASK) == FP_MAILDIR) {
 178       rv = maildir_append(fpp->realfile, fpp->fp);
 179       goto jleave;
 180    }
 181
 182    outfd = open(fpp->realfile, (fpp->omode | O_CREAT) & ~O_EXCL, 0666);
 183    if (outfd == -1) {
 184       n_err(_("Fatal: cannot create \"%s\": %s\n"),
 185          fpp->realfile, strerror(errno));
 186       goto jleave;
 187    }
 188    if (!(fpp->omode & O_APPEND))
 189       ftruncate(outfd, 0);
 190
 191    cmd[2] = NULL;
 192    switch (fpp->flags & FP_MASK) {
 193    case FP_GZIP:
 194       cmd[0] = "gzip";  cmd[1] = "-c"; break;
 195    case FP_BZIP2:
 196       cmd[0] = "bzip2"; cmd[1] = "-c"; break;
 197    case FP_XZ:
 198       cmd[0] = "xz";    cmd[1] = "-c"; break;
 199    default:
 200       cmd[0] = "cat";   cmd[1] = NULL; break;
 201    case FP_HOOK:
 202       if ((cmd[0] = ok_vlook(SHELL)) == NULL)
 203          cmd[0] = XSHELL;
 204       cmd[1] = "-c";
 205       cmd[2] = fpp->save_cmd;
 206    }
 207    if (run_command(cmd[0], 0, fileno(fpp->fp), outfd, cmd[1], cmd[2], NULL)
 208          >= 0)
 209       rv = OKAY;
 210    close(outfd);
 211 jleave:
 212    NYD_LEAVE;
 213    return rv;
 214 }
 215
 216 static int
 217 _file_load(int flags, int infd, int outfd, char const *load_cmd)
 218 {
 219    char const *cmd[3];
 220    int rv;
 221    NYD_ENTER;
 222
 223    cmd[2] = NULL;
 224    switch (flags & FP_MASK) {
 225    case FP_GZIP:     cmd[0] = "gzip";  cmd[1] = "-cd"; break;
 226    case FP_BZIP2:    cmd[0] = "bzip2"; cmd[1] = "-cd"; break;
 227    case FP_XZ:       cmd[0] = "xz";    cmd[1] = "-cd"; break;
 228    default:          cmd[0] = "cat";   cmd[1] = NULL;  break;
 229    case FP_HOOK:
 230       if ((cmd[0] = ok_vlook(SHELL)) == NULL)
 231          cmd[0] = XSHELL;
 232       cmd[1] = "-c";
 233       cmd[2] = load_cmd;
 234       break;
 235    case FP_MAILDIR:
 236    case FP_IMAP:
 237       rv = 0;
 238       goto jleave;
 239    }
 240
 241    rv = run_command(cmd[0], 0, infd, outfd, cmd[1], cmd[2], NULL);
 242 jleave:
 243    NYD_LEAVE;
 244    return rv;
 245 }
 246
 247 static enum okay
 248 unregister_file(FILE *fp)
 249 {
 250    struct fp **pp, *p;
 251    enum okay rv = OKAY;
 252    NYD_ENTER;
 253
 254    for (pp = &fp_head; (p = *pp) != NULL; pp = &p->link)
 255       if (p->fp == fp) {
 256          if ((p->flags & FP_MASK) != FP_RAW) /* TODO ;} */
 257             rv = _file_save(p);
 258          *pp = p->link;
 259          if (p->save_cmd != NULL)
 260             free(p->save_cmd);
 261          if (p->realfile != NULL)
 262             free(p->realfile);
 263          free(p);
 264          goto jleave;
 265       }
 266    DBGOR(n_panic, n_alert)(_("Invalid file pointer"));
 267    rv = STOP;
 268 jleave:
 269    NYD_LEAVE;
 270    return rv;
 271 }
 272
 273 static int
 274 file_pid(FILE *fp)
 275 {
 276    int rv;
 277    struct fp *p;
 278    NYD2_ENTER;
 279
 280    rv = -1;
 281    for (p = fp_head; p; p = p->link)
 282       if (p->fp == fp) {
 283          rv = p->pid;
 284          break;
 285       }
 286    NYD2_LEAVE;
 287    return rv;
 288 }
 289
 290 static void
 291 _sigchld(int signo)
 292 {
 293    pid_t pid;
 294    int status;
 295    struct child *cp;
 296    NYD_X; /* Signal handler */
 297    UNUSED(signo);
 298
 299    for (;;) {
 300       pid = waitpid(-1, &status, WNOHANG);
 301       if (pid <= 0) {
 302          if (pid == -1 && errno == EINTR)
 303             continue;
 304          break;
 305       }
 306
 307       if ((cp = _findchild(pid, FAL0)) != NULL) {
 308          if (cp->free)
 309             cp->pid = -1; /* XXX Was _delchild(cp);# */
 310          else {
 311             cp->done = 1;
 312             cp->status = status;
 313          }
 314       }
 315    }
 316 }
 317
 318 static int
 319 wait_command(int pid)
 320 {
 321    int rv = 0;
 322    NYD_ENTER;
 323
 324    if (!wait_child(pid, NULL)) {
 325       if (ok_blook(bsdcompat) || ok_blook(bsdmsgs))
 326          n_err(_("Fatal error in process\n"));
 327       rv = -1;
 328    }
 329    NYD_LEAVE;
 330    return rv;
 331 }
 332
 333 static struct child *
 334 _findchild(int pid, bool_t create)
 335 {
 336    struct child **cpp;
 337    NYD_ENTER;
 338
 339    for (cpp = &_popen_child; *cpp != NULL && (*cpp)->pid != pid;
 340          cpp = &(*cpp)->link)
 341       ;
 342
 343    if (*cpp == NULL && create) {
 344       *cpp = smalloc(sizeof **cpp);
 345       (*cpp)->pid = pid;
 346       (*cpp)->done = (*cpp)->free = 0;
 347       (*cpp)->link = NULL;
 348    }
 349    NYD_LEAVE;
 350    return *cpp;
 351 }
 352
 353 static void
 354 _delchild(struct child *cp)
 355 {
 356    struct child **cpp;
 357    NYD_ENTER;
 358
 359    cpp = &_popen_child;
 360    for (;;) {
 361       if (*cpp == cp) {
 362          *cpp = cp->link;
 363          free(cp);
 364          break;
 365       }
 366       if (*(cpp = &(*cpp)->link) == NULL) {
 367          DBG( n_err("! popen.c:_delchild(): implementation error\n"); )
 368          break;
 369       }
 370    }
 371    NYD_LEAVE;
 372 }
 373
 374 FL void
 375 command_manager_start(void)
 376 {
 377    struct sigaction nact, oact;
 378    NYD_ENTER;
 379
 380    nact.sa_handler = &_sigchld;
 381    sigemptyset(&nact.sa_mask);
 382    nact.sa_flags = 0
 383 #ifdef SA_RESTART
 384          | SA_RESTART
 385 #endif
 386 #ifdef SA_NOCLDSTOP
 387          | SA_NOCLDSTOP
 388 #endif
 389          ;
 390    if (sigaction(SIGCHLD, &nact, &oact) != 0)
 391       n_panic(_("Cannot install signal handler for child process management"));
 392    NYD_LEAVE;
 393 }
 394
 395 FL FILE *
 396 safe_fopen(char const *file, char const *oflags, int *xflags)
 397 {
 398    int osflags, fd;
 399    FILE *fp = NULL;
 400    NYD2_ENTER; /* (only for Fopen() and once in lex.c) */
 401
 402    if (scan_mode(oflags, &osflags) < 0)
 403       goto jleave;
 404    osflags |= _O_CLOEXEC;
 405    if (xflags != NULL)
 406       *xflags = osflags;
 407
 408    if ((fd = open(file, osflags, 0666)) == -1)
 409       goto jleave;
 410    _CLOEXEC_SET(fd);
 411
 412    fp = fdopen(fd, oflags);
 413 jleave:
 414    NYD2_LEAVE;
 415    return fp;
 416 }
 417
 418 FL FILE *
 419 Fopen(char const *file, char const *oflags)
 420 {
 421    FILE *fp;
 422    int osflags;
 423    NYD_ENTER;
 424
 425    if ((fp = safe_fopen(file, oflags, &osflags)) != NULL)
 426       register_file(fp, osflags, 0, 0, FP_RAW, NULL, 0L, NULL);
 427    NYD_LEAVE;
 428    return fp;
 429 }
 430
 431 FL FILE *
 432 Fdopen(int fd, char const *oflags, bool_t nocloexec)
 433 {
 434    FILE *fp;
 435    int osflags;
 436    NYD_ENTER;
 437
 438    scan_mode(oflags, &osflags);
 439    if (!nocloexec)
 440       osflags |= _O_CLOEXEC; /* Ensured to be set by caller as documented! */
 441
 442    if ((fp = fdopen(fd, oflags)) != NULL)
 443       register_file(fp, osflags, 0, 0, FP_RAW, NULL, 0L, NULL);
 444    NYD_LEAVE;
 445    return fp;
 446 }
 447
 448 FL int
 449 Fclose(FILE *fp)
 450 {
 451    int i = 0;
 452    NYD_ENTER;
 453
 454    if (unregister_file(fp) == OKAY)
 455       i |= 1;
 456    if (fclose(fp) == 0)
 457       i |= 2;
 458    NYD_LEAVE;
 459    return (i == 3 ? 0 : EOF);
 460 }
 461
 462 FL FILE *
 463 Zopen(char const *file, char const *oflags) /* FIXME MESS! */
 464 {
 465    FILE *rv = NULL;
 466    char const *cload = NULL, *csave = NULL;
 467    int flags, osflags, mode, infd;
 468    enum oflags rof;
 469    long offset;
 470    enum protocol p;
 471    NYD_ENTER;
 472
 473    if (scan_mode(oflags, &osflags) < 0)
 474       goto jleave;
 475
 476    flags = 0;
 477    rof = OF_RDWR | OF_UNLINK;
 478    if (osflags & O_APPEND)
 479       rof |= OF_APPEND;
 480    mode = (osflags == O_RDONLY) ? R_OK : R_OK | W_OK;
 481
 482    if ((osflags & O_APPEND) && ((p = which_protocol(file)) == PROTO_IMAP ||
 483          p == PROTO_MAILDIR)) {
 484       flags |= (p == PROTO_IMAP) ? FP_IMAP : FP_MAILDIR;
 485       osflags = O_RDWR | O_APPEND | O_CREAT;
 486       infd = -1;
 487    } else {
 488       char const *ext;
 489
 490       if ((ext = strrchr(file, '.')) != NULL) {
 491          if (!strcmp(ext, ".gz"))
 492             flags |= FP_GZIP;
 493          else if (!strcmp(ext, ".xz"))
 494             flags |= FP_XZ;
 495          else if (!strcmp(ext, ".bz2"))
 496             flags |= FP_BZIP2;
 497          else {
 498 #undef _X1
 499 #define _X1 "file-hook-load-"
 500 #undef _X2
 501 #define _X2 "file-hook-save-"
 502             size_t l = strlen(++ext);
 503             char *vbuf = ac_alloc(l + MAX(sizeof(_X1), sizeof(_X2)));
 504
 505             memcpy(vbuf, _X1, sizeof(_X1) -1);
 506             memcpy(vbuf + sizeof(_X1) -1, ext, l);
 507             vbuf[sizeof(_X1) -1 + l] = '\0';
 508             cload = vok_vlook(vbuf);
 509             memcpy(vbuf, _X2, sizeof(_X2) -1);
 510             memcpy(vbuf + sizeof(_X2) -1, ext, l);
 511             vbuf[sizeof(_X2) -1 + l] = '\0';
 512             csave = vok_vlook(vbuf);
 513 #undef _X2
 514 #undef _X1
 515             ac_free(vbuf);
 516
 517             if ((csave != NULL) && (cload != NULL))
 518                flags |= FP_HOOK;
 519             else if ((csave != NULL) | (cload != NULL)) {
 520                n_alert(_("Only one of *mailbox-(load|save)-%s* is set!  "
 521                   "Treating as plain text!"), ext);
 522                goto jraw;
 523             } else
 524                goto jraw;
 525          }
 526       } else {
 527 jraw:
 528          /*flags |= FP_RAW;*/
 529          rv = Fopen(file, oflags);
 530          goto jleave;
 531       }
 532
 533       if ((infd = open(file, (mode & W_OK) ? O_RDWR : O_RDONLY)) == -1 &&
 534             (!(osflags & O_CREAT) || errno != ENOENT))
 535          goto jleave;
 536    }
 537
 538    if ((rv = Ftmp(NULL, "zopen", rof, 0600)) == NULL) {
 539       n_perr(_("tmpfile"), 0);
 540       goto jerr;
 541    }
 542
 543    if (flags & (FP_IMAP | FP_MAILDIR))
 544       ;
 545    else if (infd >= 0) {
 546       if (_file_load(flags, infd, fileno(rv), cload) < 0) {
 547 jerr:
 548          if (rv != NULL)
 549             Fclose(rv);
 550          rv = NULL;
 551          if (infd >= 0)
 552             close(infd);
 553          goto jleave;
 554       }
 555    } else {
 556       if ((infd = creat(file, 0666)) == -1) {
 557          Fclose(rv);
 558          rv = NULL;
 559          goto jleave;
 560       }
 561    }
 562
 563    if (infd >= 0)
 564       close(infd);
 565    fflush(rv);
 566
 567    if (!(osflags & O_APPEND))
 568       rewind(rv);
 569    if ((offset = ftell(rv)) == -1) {
 570       Fclose(rv);
 571       rv = NULL;
 572       goto jleave;
 573    }
 574
 575    register_file(rv, osflags, 0, 0, flags, file, offset, csave);
 576 jleave:
 577    NYD_LEAVE;
 578    return rv;
 579 }
 580
 581 FL FILE *
 582 Ftmp(char **fn, char const *prefix, enum oflags oflags, int mode)
 583 {
 584    FILE *fp = NULL;
 585    size_t maxname, tries;
 586    char *cp_base, *cp;
 587    int osoflags, fd;
 588    NYD_ENTER;
 589
 590    assert((oflags & OF_WRONLY) || (oflags & OF_RDWR));
 591    assert(!(oflags & OF_RDONLY));
 592
 593    maxname = NAME_MAX;
 594 #ifdef HAVE_PATHCONF
 595    {  long pc;
 596
 597       if ((pc = pathconf(tempdir, _PC_NAME_MAX)) != -1)
 598          maxname = (size_t)pc;
 599    }
 600 #endif
 601
 602    cp_base =
 603    cp = smalloc(strlen(tempdir) + 1 + maxname +1);
 604    cp = sstpcpy(cp, tempdir);
 605    *cp++ = '/';
 606
 607    osoflags = O_CREAT | O_EXCL | _O_CLOEXEC;
 608    osoflags |= (oflags & OF_WRONLY) ? O_WRONLY : O_RDWR;
 609    if (oflags & OF_APPEND)
 610       osoflags |= O_APPEND;
 611
 612    for (tries = 0;; ++tries) {
 613       size_t i;
 614       char *x;
 615
 616       x = sstpcpy(cp, UAGENT);
 617       *x++ = '-';
 618       if (*prefix != '\0') {
 619          x = sstpcpy(x, prefix);
 620          *x++ = '-';
 621       }
 622
 623       /* Calculate length of a random string addon */
 624       i = PTR2SIZE(x - cp);
 625       if (i >= maxname >> 1) {
 626          x = cp;
 627          i = maxname -1;
 628       } else
 629          i = maxname >> 1;
 630       /* But don't be too fatalistic */
 631       if (i > 8 && tries < FTMP_OPEN_TRIES / 2)
 632          i = 8;
 633       memcpy(x, getrandstring(i), i +1);
 634
 635       hold_all_sigs();
 636       if ((fd = open(cp_base, osoflags, mode)) != -1) {
 637          _CLOEXEC_SET(fd);
 638          break;
 639       }
 640       if (tries >= FTMP_OPEN_TRIES)
 641          goto jfree;
 642       rele_all_sigs();
 643    }
 644
 645    if (oflags & OF_REGISTER)
 646       fp = Fdopen(fd, (oflags & OF_RDWR ? "w+" : "w"), FAL0);
 647    else
 648       fp = fdopen(fd, (oflags & OF_RDWR ? "w+" : "w"));
 649
 650    if (fp == NULL || (oflags & OF_UNLINK)) {
 651       unlink(cp_base);
 652       goto jfree;
 653    }
 654
 655    if (fn != NULL)
 656       *fn = cp_base;
 657    else
 658       free(cp_base);
 659 jleave:
 660    if (fp == NULL || !(oflags & OF_HOLDSIGS))
 661       rele_all_sigs();
 662    NYD_LEAVE;
 663    return fp;
 664 jfree:
 665    if ((cp = cp_base) != NULL)
 666       free(cp);
 667    goto jleave;
 668 }
 669
 670 FL void
 671 Ftmp_release(char **fn)
 672 {
 673    char *cp;
 674    NYD_ENTER;
 675
 676    cp = *fn;
 677    *fn = NULL;
 678    if (cp != NULL) {
 679       unlink(cp);
 680       rele_all_sigs();
 681       free(cp);
 682    }
 683    NYD_LEAVE;
 684 }
 685
 686 FL void
 687 Ftmp_free(char **fn)
 688 {
 689    char *cp;
 690    NYD_ENTER;
 691
 692    cp = *fn;
 693    *fn = NULL;
 694    if (cp != NULL)
 695       free(cp);
 696    NYD_LEAVE;
 697 }
 698
 699 FL bool_t
 700 pipe_cloexec(int fd[2])
 701 {
 702    bool_t rv = FAL0;
 703    NYD_ENTER;
 704
 705 #ifdef HAVE_PIPE2
 706    if (pipe2(fd, O_CLOEXEC) == -1)
 707       goto jleave;
 708 #else
 709    if (pipe(fd) == -1)
 710       goto jleave;
 711    (void)fcntl(fd[0], F_SETFD, FD_CLOEXEC);
 712    (void)fcntl(fd[1], F_SETFD, FD_CLOEXEC);
 713 #endif
 714    rv = TRU1;
 715 jleave:
 716    NYD_LEAVE;
 717    return rv;
 718 }
 719
 720 FL FILE *
 721 Popen(char const *cmd, char const *mode, char const *sh,
 722    char const **env_addon, int newfd1)
 723 {
 724    int p[2], myside, hisside, fd0, fd1, pid;
 725    char mod[2] = {'0', '\0'};
 726    sigset_t nset;
 727    FILE *rv = NULL;
 728    NYD_ENTER;
 729
 730    /* First clean up child structures */
 731    {  sigset_t oset;
 732       struct child **cpp, *cp;
 733
 734       sigfillset(&nset);
 735       sigprocmask(SIG_BLOCK, &nset, &oset);
 736
 737       for (cpp = &_popen_child; *cpp != NULL;) {
 738          if ((*cpp)->pid == -1) {
 739             cp = *cpp;
 740             *cpp = cp->link;
 741             free(cp);
 742          } else
 743             cpp = &(*cpp)->link;
 744       }
 745
 746       sigprocmask(SIG_SETMASK, &oset, NULL);
 747    }
 748
 749    if (!pipe_cloexec(p))
 750       goto jleave;
 751
 752    if (*mode == 'r') {
 753       myside = p[READ];
 754       fd0 = -1;
 755       hisside = fd1 = p[WRITE];
 756       mod[0] = *mode;
 757    } else if (*mode == 'W') {
 758       myside = p[WRITE];
 759       hisside = fd0 = p[READ];
 760       fd1 = newfd1;
 761       mod[0] = 'w';
 762    } else {
 763       myside = p[WRITE];
 764       hisside = fd0 = p[READ];
 765       fd1 = -1;
 766       mod[0] = 'w';
 767    }
 768
 769    sigemptyset(&nset);
 770
 771    if (cmd == (char*)-1) {
 772       if ((pid = fork_child()) == -1)
 773          n_perr(_("fork"), 0);
 774       else if (pid == 0) {
 775          union {char const *ccp; int (*ptf)(void); int es;} u;
 776          prepare_child(&nset, fd0, fd1);
 777          close(p[READ]);
 778          close(p[WRITE]);
 779          u.ccp = sh;
 780          u.es = (*u.ptf)();
 781          _exit(u.es);
 782       }
 783    } else if (sh == NULL) {
 784       pid = start_command(cmd, &nset, fd0, fd1, NULL, NULL, NULL, env_addon);
 785    } else {
 786       pid = start_command(sh, &nset, fd0, fd1, "-c", cmd, NULL, env_addon);
 787    }
 788    if (pid < 0) {
 789       close(p[READ]);
 790       close(p[WRITE]);
 791       goto jleave;
 792    }
 793    close(hisside);
 794    if ((rv = fdopen(myside, mod)) != NULL)
 795       register_file(rv, 0, 1, pid, FP_RAW, NULL, 0L, NULL);
 796    else
 797       close(myside);
 798 jleave:
 799    NYD_LEAVE;
 800    return rv;
 801 }
 802
 803 FL bool_t
 804 Pclose(FILE *ptr, bool_t dowait)
 805 {
 806    sigset_t nset, oset;
 807    int pid;
 808    bool_t rv = FAL0;
 809    NYD_ENTER;
 810
 811    pid = file_pid(ptr);
 812    if (pid < 0)
 813       goto jleave;
 814    unregister_file(ptr);
 815    fclose(ptr);
 816    if (dowait) {
 817       sigemptyset(&nset);
 818       sigaddset(&nset, SIGINT);
 819       sigaddset(&nset, SIGHUP);
 820       sigprocmask(SIG_BLOCK, &nset, &oset);
 821       rv = wait_child(pid, NULL);
 822       sigprocmask(SIG_SETMASK, &oset, NULL);
 823    } else {
 824       free_child(pid);
 825       rv = TRU1;
 826    }
 827 jleave:
 828    NYD_LEAVE;
 829    return rv;
 830 }
 831
 832 FL void
 833 close_all_files(void)
 834 {
 835    NYD_ENTER;
 836    while (fp_head != NULL)
 837       if (fp_head->pipe)
 838          Pclose(fp_head->fp, TRU1);
 839       else
 840          Fclose(fp_head->fp);
 841    NYD_LEAVE;
 842 }
 843
 844 FL int
 845 fork_child(void)
 846 {
 847    struct child *cp;
 848    int pid;
 849    NYD_ENTER;
 850
 851    cp = _findchild(0, TRU1);
 852
 853    if ((cp->pid = pid = fork()) == -1) {
 854       _delchild(cp);
 855       n_perr(_("fork"), 0);
 856    }
 857    NYD_LEAVE;
 858    return pid;
 859 }
 860
 861 FL int
 862 run_command(char const *cmd, sigset_t *mask, int infd, int outfd,
 863    char const *a0, char const *a1, char const *a2)
 864 {
 865    int rv;
 866    NYD_ENTER;
 867
 868    if ((rv = start_command(cmd, mask, infd, outfd, a0, a1, a2, NULL)) < 0)
 869       rv = -1;
 870    else
 871       rv = wait_command(rv);
 872    NYD_LEAVE;
 873    return rv;
 874 }
 875
 876 FL int
 877 start_command(char const *cmd, sigset_t *mask, int infd, int outfd,
 878    char const *a0, char const *a1, char const *a2,
 879    char const **env_addon)
 880 {
 881    int rv;
 882    NYD_ENTER;
 883
 884    if ((rv = fork_child()) == -1) {
 885       n_perr(_("fork"), 0);
 886       rv = -1;
 887    } else if (rv == 0) {
 888       char *argv[128];
 889       int i;
 890
 891       if (env_addon != NULL) { /* TODO env_addon; should have struct child */
 892          extern char **environ;
 893          size_t ei, ei_orig, ai, ai_orig;
 894          char **env;
 895
 896          /* TODO note we don't check the POSIX limit:
 897           * the total space used to store the environment and the arguments to
 898           * the process is limited to {ARG_MAX} bytes */
 899          for (ei = 0; environ[ei] != NULL; ++ei)
 900             ;
 901          ei_orig = ei;
 902          for (ai = 0; env_addon[ai] != NULL; ++ai)
 903             ;
 904          ai_orig = ai;
 905          env = ac_alloc(sizeof(*env) * (ei + ai +1));
 906          memcpy(env, environ, sizeof(*env) * ei);
 907
 908          /* Replace all those keys that yet exist */
 909          while (ai-- > 0) {
 910             char const *ee, *kvs;
 911             size_t kl;
 912
 913             ee = env_addon[ai];
 914             kvs = strchr(ee, '=');
 915             assert(kvs != NULL);
 916             kl = PTR2SIZE(kvs - ee);
 917             assert(kl > 0);
 918             for (ei = ei_orig; ei-- > 0;) {
 919                char const *ekvs = strchr(env[ei], '=');
 920                if (ekvs != NULL && kl == PTR2SIZE(ekvs - env[ei]) &&
 921                      !memcmp(ee, env[ei], kl)) {
 922                   env[ei] = UNCONST(ee);
 923                   env_addon[ai] = NULL;
 924                   break;
 925                }
 926             }
 927          }
 928
 929          /* And append the rest */
 930          for (ei = ei_orig, ai = ai_orig; ai-- > 0;)
 931             if (env_addon[ai] != NULL)
 932                env[ei++] = UNCONST(env_addon[ai]);
 933
 934          env[ei] = NULL;
 935          environ = env;
 936       }
 937
 938       i = getrawlist(cmd, strlen(cmd), argv, NELEM(argv), 0);
 939
 940       if ((argv[i++] = UNCONST(a0)) != NULL &&
 941             (argv[i++] = UNCONST(a1)) != NULL &&
 942             (argv[i++] = UNCONST(a2)) != NULL)
 943          argv[i] = NULL;
 944       prepare_child(mask, infd, outfd);
 945       execvp(argv[0], argv);
 946       perror(argv[0]);
 947       _exit(EXIT_ERR);
 948    }
 949    NYD_LEAVE;
 950    return rv;
 951 }
 952
 953 FL void
 954 prepare_child(sigset_t *nset, int infd, int outfd)
 955 {
 956    int i;
 957    sigset_t fset;
 958    NYD_ENTER;
 959
 960    /* All file descriptors other than 0, 1, and 2 are supposed to be cloexec */
 961    if (infd >= 0)
 962       dup2(infd, STDIN_FILENO);
 963    if (outfd >= 0)
 964       dup2(outfd, STDOUT_FILENO);
 965
 966    if (nset) {
 967       for (i = 1; i < NSIG; ++i)
 968          if (sigismember(nset, i))
 969             safe_signal(i, SIG_IGN);
 970       if (!sigismember(nset, SIGINT))
 971          safe_signal(SIGINT, SIG_DFL);
 972    }
 973
 974    sigemptyset(&fset);
 975    sigprocmask(SIG_SETMASK, &fset, NULL);
 976    NYD_LEAVE;
 977 }
 978
 979 FL void
 980 free_child(int pid)
 981 {
 982    sigset_t nset, oset;
 983    struct child *cp;
 984    NYD_ENTER;
 985
 986    sigemptyset(&nset);
 987    sigaddset(&nset, SIGCHLD);
 988    sigprocmask(SIG_BLOCK, &nset, &oset);
 989
 990    if ((cp = _findchild(pid, FAL0)) != NULL) {
 991       if (cp->done)
 992          _delchild(cp);
 993       else
 994          cp->free = 1;
 995    }
 996
 997    sigprocmask(SIG_SETMASK, &oset, NULL);
 998    NYD_LEAVE;
 999 }
1000
1001 FL bool_t
1002 wait_child(int pid, int *wait_status)
1003 {
1004    sigset_t nset, oset;
1005    struct child *cp;
1006    int ws;
1007    bool_t rv;
1008    NYD_ENTER;
1009
1010    sigemptyset(&nset);
1011    sigaddset(&nset, SIGCHLD);
1012    sigprocmask(SIG_BLOCK, &nset, &oset);
1013
1014    cp = _findchild(pid, FAL0);
1015    if (cp != NULL) {
1016       while (!cp->done)
1017          sigsuspend(&oset);
1018       ws = cp->status;
1019       _delchild(cp);
1020    } else
1021       ws = 0;
1022
1023    sigprocmask(SIG_SETMASK, &oset, NULL);
1024
1025    if (wait_status != NULL)
1026       *wait_status = ws;
1027    rv = (WIFEXITED(ws) && WEXITSTATUS(ws) == 0);
1028    NYD_LEAVE;
1029    return rv;
1030 }
1031
1032 /* s-it-mode */