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 - 2017 Steffen (Daode) Nurpmeso <steffen@sdaoden.eu>.
   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    struct termios *fp_tios;
  53    long        offset;
  54    int         omode;
  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_MAILDIR  = 1<<4,
  62       FP_HOOK     = 1<<5,
  63       FP_PIPE     = 1<<6,
  64       FP_MASK     = (1<<7) - 1,
  65       /* TODO FP_UNLINK: should be in a separated process so that unlinking
  66        * TODO the temporary "garbage" is "safe"(r than it is like that) */
  67       FP_UNLINK   = 1<<9,
  68       FP_TERMIOS  = 1<<10
  69    }           flags;
  70 };
  71
  72 struct child {
  73    int         pid;
  74    char        done;
  75    char        free;
  76    int         status;
  77    struct child *link;
  78 };
  79
  80 static struct fp     *fp_head;
  81 static struct child  *_popen_child;
  82
  83 /* TODO Rather temporary: deal with job control with FD_PASS */
  84 static struct termios a_popen_tios;
  85 static sighandler_type a_popen_otstp, a_popen_ottin, a_popen_ottou;
  86 static volatile int a_popen_hadsig;
  87
  88 static int           scan_mode(char const *mode, int *omode);
  89 static void          register_file(FILE *fp, int omode, int pid,
  90                         int flags, char const *realfile, long offset,
  91                         char const *save_cmd, struct termios *tiosp);
  92 static enum okay     _file_save(struct fp *fpp);
  93 static int           _file_load(int flags, int infd, int outfd,
  94                         char const *load_cmd);
  95 static enum okay     unregister_file(FILE *fp, struct termios **tiosp);
  96 static int           file_pid(FILE *fp);
  97
  98 /* TODO Rather temporary: deal with job control with FD_PASS */
  99 static void a_popen_jobsigs_up(void);
 100 static void a_popen_jobsigs_down(void);
 101 static void a_popen_jobsig(int sig);
 102
 103 /* Handle SIGCHLD */
 104 static void          _sigchld(int signo);
 105
 106 static struct child *_findchild(int pid, bool_t create);
 107 static void          _delchild(struct child *cp);
 108
 109 static int
 110 scan_mode(char const *mode, int *omode)
 111 {
 112    static struct {
 113       char const  mode[4];
 114       int         omode;
 115    } const maps[] = {
 116       {"r", O_RDONLY},
 117       {"w", O_WRONLY | O_CREAT | n_O_NOFOLLOW | O_TRUNC},
 118       {"wx", O_WRONLY | O_CREAT | O_EXCL},
 119       {"a", O_WRONLY | O_APPEND | O_CREAT | n_O_NOFOLLOW},
 120       {"a+", O_RDWR | O_APPEND},
 121       {"r+", O_RDWR},
 122       {"w+", O_RDWR | O_CREAT | O_EXCL}
 123    };
 124
 125    int i;
 126    NYD2_ENTER;
 127
 128    for (i = 0; UICMP(z, i, <, n_NELEM(maps)); ++i)
 129       if (!strcmp(maps[i].mode, mode)) {
 130          *omode = maps[i].omode;
 131          i = 0;
 132          goto jleave;
 133       }
 134
 135    n_alert(_("Internal error: bad stdio open mode %s"), mode);
 136    errno = EINVAL;
 137    *omode = 0; /* (silence CC) */
 138    i = -1;
 139 jleave:
 140    NYD2_LEAVE;
 141    return i;
 142 }
 143
 144 static void
 145 register_file(FILE *fp, int omode, int pid, int flags,
 146    char const *realfile, long offset, char const *save_cmd,
 147    struct termios *tiosp)
 148 {
 149    struct fp *fpp;
 150    NYD_ENTER;
 151
 152    assert(!(flags & FP_UNLINK) || realfile != NULL);
 153    assert(!(flags & FP_TERMIOS) || tiosp != NULL);
 154
 155    fpp = smalloc(sizeof *fpp);
 156    fpp->fp = fp;
 157    fpp->omode = omode;
 158    fpp->pid = pid;
 159    fpp->link = fp_head;
 160    fpp->flags = flags;
 161    fpp->realfile = (realfile != NULL) ? sstrdup(realfile) : NULL;
 162    fpp->save_cmd = (save_cmd != NULL) ? sstrdup(save_cmd) : NULL;
 163    fpp->fp_tios = tiosp;
 164    fpp->offset = offset;
 165    fp_head = fpp;
 166    NYD_LEAVE;
 167 }
 168
 169 static enum okay
 170 _file_save(struct fp *fpp)
 171 {
 172    char const *cmd[3];
 173    int outfd;
 174    enum okay rv;
 175    NYD_ENTER;
 176
 177    if (fpp->omode == O_RDONLY) {
 178       rv = OKAY;
 179       goto jleave;
 180    }
 181    rv = STOP;
 182
 183    fflush(fpp->fp);
 184    clearerr(fpp->fp);
 185
 186    /* Ensure the I/O library doesn't optimize the fseek(3) away! */
 187    if(!n_real_seek(fpp->fp, fpp->offset, SEEK_SET)){
 188       outfd = errno;
 189       n_err(_("Fatal: cannot restore file position and save %s: %s\n"),
 190          n_shexp_quote_cp(fpp->realfile, FAL0), strerror(outfd));
 191       goto jleave;
 192    }
 193
 194    if ((fpp->flags & FP_MASK) == FP_MAILDIR) {
 195       rv = maildir_append(fpp->realfile, fpp->fp, fpp->offset);
 196       goto jleave;
 197    }
 198
 199    outfd = open(fpp->realfile,
 200          ((fpp->omode | O_CREAT | (fpp->omode & O_APPEND ? 0 : O_TRUNC) |
 201             n_O_NOFOLLOW) & ~O_EXCL), 0666);
 202    if (outfd == -1) {
 203       outfd = errno;
 204       n_err(_("Fatal: cannot create %s: %s\n"),
 205          n_shexp_quote_cp(fpp->realfile, FAL0), strerror(outfd));
 206       goto jleave;
 207    }
 208
 209    cmd[2] = NULL;
 210    switch (fpp->flags & FP_MASK) {
 211    case FP_GZIP:
 212       cmd[0] = "gzip";  cmd[1] = "-c"; break;
 213    case FP_BZIP2:
 214       cmd[0] = "bzip2"; cmd[1] = "-c"; break;
 215    case FP_XZ:
 216       cmd[0] = "xz";    cmd[1] = "-c"; break;
 217    default:
 218       cmd[0] = "cat";   cmd[1] = NULL; break;
 219    case FP_HOOK:
 220       cmd[0] = ok_vlook(SHELL);
 221       cmd[1] = "-c";
 222       cmd[2] = fpp->save_cmd;
 223    }
 224    if (run_command(cmd[0], 0, fileno(fpp->fp), outfd,
 225          cmd[1], cmd[2], NULL, NULL) >= 0)
 226       rv = OKAY;
 227
 228    close(outfd);
 229 jleave:
 230    NYD_LEAVE;
 231    return rv;
 232 }
 233
 234 static int
 235 _file_load(int flags, int infd, int outfd, char const *load_cmd)
 236 {
 237    char const *cmd[3];
 238    int rv;
 239    NYD_ENTER;
 240
 241    cmd[2] = NULL;
 242    switch (flags & FP_MASK) {
 243    case FP_GZIP:     cmd[0] = "gzip";  cmd[1] = "-cd"; break;
 244    case FP_BZIP2:    cmd[0] = "bzip2"; cmd[1] = "-cd"; break;
 245    case FP_XZ:       cmd[0] = "xz";    cmd[1] = "-cd"; break;
 246    default:          cmd[0] = "cat";   cmd[1] = NULL;  break;
 247    case FP_HOOK:
 248       cmd[0] = ok_vlook(SHELL);
 249       cmd[1] = "-c";
 250       cmd[2] = load_cmd;
 251       break;
 252    case FP_MAILDIR:
 253       rv = 0;
 254       goto jleave;
 255    }
 256
 257    rv = run_command(cmd[0], 0, infd, outfd, cmd[1], cmd[2], NULL, NULL);
 258 jleave:
 259    NYD_LEAVE;
 260    return rv;
 261 }
 262
 263 static enum okay
 264 unregister_file(FILE *fp, struct termios **tiosp)
 265 {
 266    struct fp **pp, *p;
 267    enum okay rv = OKAY;
 268    NYD_ENTER;
 269
 270    if (tiosp)
 271       *tiosp = NULL;
 272
 273    for (pp = &fp_head; (p = *pp) != NULL; pp = &p->link)
 274       if (p->fp == fp) {
 275          switch (p->flags & FP_MASK) {
 276          case FP_RAW:
 277          case FP_PIPE:
 278             break;
 279          default:
 280             rv = _file_save(p);
 281             break;
 282          }
 283          if ((p->flags & FP_UNLINK) && unlink(p->realfile))
 284             rv = STOP;
 285
 286          *pp = p->link;
 287          if (p->save_cmd != NULL)
 288             free(p->save_cmd);
 289          if (p->realfile != NULL)
 290             free(p->realfile);
 291          if (p->flags & FP_TERMIOS) {
 292             if (tiosp != NULL)
 293                *tiosp = p->fp_tios;
 294             else
 295                free(p->fp_tios);
 296          }
 297          free(p);
 298          goto jleave;
 299       }
 300    DBGOR(n_panic, n_alert)(_("Invalid file pointer"));
 301    rv = STOP;
 302 jleave:
 303    NYD_LEAVE;
 304    return rv;
 305 }
 306
 307 static int
 308 file_pid(FILE *fp)
 309 {
 310    int rv;
 311    struct fp *p;
 312    NYD2_ENTER;
 313
 314    rv = -1;
 315    for (p = fp_head; p; p = p->link)
 316       if (p->fp == fp) {
 317          rv = p->pid;
 318          break;
 319       }
 320    NYD2_LEAVE;
 321    return rv;
 322 }
 323
 324 static void
 325 a_popen_jobsigs_up(void){
 326    sigset_t nset, oset;
 327    NYD2_ENTER;
 328
 329    sigfillset(&nset);
 330
 331    sigprocmask(SIG_BLOCK, &nset, &oset);
 332    a_popen_otstp = safe_signal(SIGTSTP, &a_popen_jobsig);
 333    a_popen_ottin = safe_signal(SIGTTIN, &a_popen_jobsig);
 334    a_popen_ottou = safe_signal(SIGTTOU, &a_popen_jobsig);
 335
 336    /* This assumes oset contains nothing but SIGCHLD, so to say */
 337    sigdelset(&oset, SIGTSTP);
 338    sigdelset(&oset, SIGTTIN);
 339    sigdelset(&oset, SIGTTOU);
 340    sigprocmask(SIG_SETMASK, &oset, NULL);
 341    NYD2_LEAVE;
 342 }
 343
 344 static void
 345 a_popen_jobsigs_down(void){
 346    sigset_t nset, oset;
 347    NYD2_ENTER;
 348
 349    sigfillset(&nset);
 350
 351    sigprocmask(SIG_BLOCK, &nset, &oset);
 352    safe_signal(SIGTSTP, a_popen_otstp);
 353    safe_signal(SIGTTIN, a_popen_ottin);
 354    safe_signal(SIGTTOU, a_popen_ottou);
 355
 356    sigaddset(&oset, SIGTSTP);
 357    sigaddset(&oset, SIGTTIN);
 358    sigaddset(&oset, SIGTTOU);
 359    sigprocmask(SIG_SETMASK, &oset, NULL);
 360    NYD2_LEAVE;
 361 }
 362
 363 static void
 364 a_popen_jobsig(int sig){
 365    sighandler_type oldact;
 366    sigset_t nset;
 367    bool_t hadsig;
 368    NYD_X; /* Signal handler */
 369
 370    hadsig = (a_popen_hadsig != 0);
 371    a_popen_hadsig = 1;
 372    if(!hadsig)
 373       n_TERMCAP_SUSPEND(TRU1);
 374
 375    oldact = safe_signal(sig, SIG_DFL);
 376
 377    sigemptyset(&nset);
 378    sigaddset(&nset, sig);
 379    sigprocmask(SIG_UNBLOCK, &nset, NULL);
 380    n_raise(sig);
 381    sigprocmask(SIG_BLOCK, &nset, NULL);
 382
 383    safe_signal(sig, oldact);
 384 }
 385
 386 static void
 387 _sigchld(int signo)
 388 {
 389    pid_t pid;
 390    int status;
 391    struct child *cp;
 392    NYD_X; /* Signal handler */
 393    n_UNUSED(signo);
 394
 395    for (;;) {
 396       pid = waitpid(-1, &status, WNOHANG);
 397       if (pid <= 0) {
 398          if (pid == -1 && errno == EINTR)
 399             continue;
 400          break;
 401       }
 402
 403       if ((cp = _findchild(pid, FAL0)) != NULL) {
 404          if (cp->free)
 405             cp->pid = -1; /* XXX Was _delchild(cp);# */
 406          else {
 407             cp->done = 1;
 408             cp->status = status;
 409          }
 410       }
 411    }
 412 }
 413
 414 static struct child *
 415 _findchild(int pid, bool_t create)
 416 {
 417    struct child **cpp;
 418    NYD_ENTER;
 419
 420    for (cpp = &_popen_child; *cpp != NULL && (*cpp)->pid != pid;
 421          cpp = &(*cpp)->link)
 422       ;
 423
 424    if (*cpp == NULL && create) {
 425       *cpp = smalloc(sizeof **cpp);
 426       (*cpp)->pid = pid;
 427       (*cpp)->done = (*cpp)->free = 0;
 428       (*cpp)->link = NULL;
 429    }
 430    NYD_LEAVE;
 431    return *cpp;
 432 }
 433
 434 static void
 435 _delchild(struct child *cp)
 436 {
 437    struct child **cpp;
 438    NYD_ENTER;
 439
 440    cpp = &_popen_child;
 441    for (;;) {
 442       if (*cpp == cp) {
 443          *cpp = cp->link;
 444          free(cp);
 445          break;
 446       }
 447       if (*(cpp = &(*cpp)->link) == NULL) {
 448          DBG( n_err("! popen.c:_delchild(): implementation error\n"); )
 449          break;
 450       }
 451    }
 452    NYD_LEAVE;
 453 }
 454
 455 FL void
 456 command_manager_start(void)
 457 {
 458    struct sigaction nact, oact;
 459    NYD_ENTER;
 460
 461    nact.sa_handler = &_sigchld;
 462    sigemptyset(&nact.sa_mask);
 463    nact.sa_flags = SA_RESTART
 464 #ifdef SA_NOCLDSTOP
 465          | SA_NOCLDSTOP
 466 #endif
 467          ;
 468    if (sigaction(SIGCHLD, &nact, &oact) != 0)
 469       n_panic(_("Cannot install signal handler for child process management"));
 470    NYD_LEAVE;
 471 }
 472
 473 FL FILE *
 474 safe_fopen(char const *file, char const *oflags, int *xflags)
 475 {
 476    int osflags, fd;
 477    FILE *fp = NULL;
 478    NYD2_ENTER; /* (only for Fopen() and once in lex.c) */
 479
 480    if (scan_mode(oflags, &osflags) < 0)
 481       goto jleave;
 482    osflags |= _O_CLOEXEC;
 483    if (xflags != NULL)
 484       *xflags = osflags;
 485
 486    if ((fd = open(file, osflags, 0666)) == -1)
 487       goto jleave;
 488    _CLOEXEC_SET(fd);
 489
 490    fp = fdopen(fd, oflags);
 491 jleave:
 492    NYD2_LEAVE;
 493    return fp;
 494 }
 495
 496 FL FILE *
 497 Fopen(char const *file, char const *oflags)
 498 {
 499    FILE *fp;
 500    int osflags;
 501    NYD_ENTER;
 502
 503    if ((fp = safe_fopen(file, oflags, &osflags)) != NULL)
 504       register_file(fp, osflags, 0, FP_RAW, NULL, 0L, NULL, NULL);
 505    NYD_LEAVE;
 506    return fp;
 507 }
 508
 509 FL FILE *
 510 Fdopen(int fd, char const *oflags, bool_t nocloexec)
 511 {
 512    FILE *fp;
 513    int osflags;
 514    NYD_ENTER;
 515
 516    scan_mode(oflags, &osflags);
 517    if (!nocloexec)
 518       osflags |= _O_CLOEXEC; /* Ensured to be set by caller as documented! */
 519
 520    if ((fp = fdopen(fd, oflags)) != NULL)
 521       register_file(fp, osflags, 0, FP_RAW, NULL, 0L, NULL, NULL);
 522    NYD_LEAVE;
 523    return fp;
 524 }
 525
 526 FL int
 527 Fclose(FILE *fp)
 528 {
 529    int i = 0;
 530    NYD_ENTER;
 531
 532    if (unregister_file(fp, NULL) == OKAY)
 533       i |= 1;
 534    if (fclose(fp) == 0)
 535       i |= 2;
 536    NYD_LEAVE;
 537    return (i == 3 ? 0 : EOF);
 538 }
 539
 540 FL FILE *
 541 Zopen(char const *file, char const *oflags) /* FIXME MESS! */
 542 {
 543    FILE *rv = NULL;
 544    char const *cload = NULL, *csave = NULL;
 545    int flags, osflags, mode, infd;
 546    enum oflags rof;
 547    long offset;
 548    enum protocol p;
 549    NYD_ENTER;
 550
 551    if (scan_mode(oflags, &osflags) < 0)
 552       goto jleave;
 553
 554    flags = 0;
 555    rof = OF_RDWR | OF_UNLINK;
 556    if (osflags & O_APPEND)
 557       rof |= OF_APPEND;
 558    mode = (osflags == O_RDONLY) ? R_OK : R_OK | W_OK;
 559
 560    if ((osflags & O_APPEND) && ((p = which_protocol(file)) == PROTO_MAILDIR)) {
 561       flags |= FP_MAILDIR;
 562       osflags = O_RDWR | O_APPEND | O_CREAT | n_O_NOFOLLOW;
 563       infd = -1;
 564    } else {
 565       char const *ext;
 566
 567       if ((ext = strrchr(file, '.')) != NULL) {
 568          if (!asccasecmp(ext, ".gz"))
 569             flags |= FP_GZIP;
 570          else if (!asccasecmp(ext, ".xz")) {
 571             flags |= FP_XZ;
 572             osflags &= ~O_APPEND;
 573             rof &= ~OF_APPEND;
 574          } else if (!asccasecmp(ext, ".bz2")) {
 575             flags |= FP_BZIP2;
 576             osflags &= ~O_APPEND;
 577             rof &= ~OF_APPEND;
 578          } else {
 579 #undef _X1
 580 #define _X1 "file-hook-load-"
 581 #undef _X2
 582 #define _X2 "file-hook-save-"
 583             size_t l = strlen(++ext);
 584             char *vbuf = ac_alloc(l + n_MAX(sizeof(_X1), sizeof(_X2)));
 585
 586             memcpy(vbuf, _X1, sizeof(_X1) -1);
 587             memcpy(vbuf + sizeof(_X1) -1, ext, l);
 588             vbuf[sizeof(_X1) -1 + l] = '\0';
 589             cload = vok_vlook(vbuf);
 590             memcpy(vbuf, _X2, sizeof(_X2) -1);
 591             memcpy(vbuf + sizeof(_X2) -1, ext, l);
 592             vbuf[sizeof(_X2) -1 + l] = '\0';
 593             csave = vok_vlook(vbuf);
 594 #undef _X2
 595 #undef _X1
 596             ac_free(vbuf);
 597
 598             if ((csave != NULL) && (cload != NULL)) {
 599                flags |= FP_HOOK;
 600                osflags &= ~O_APPEND;
 601                rof &= ~OF_APPEND;
 602             } else if ((csave != NULL) | (cload != NULL)) {
 603                n_alert(_("Only one of *mailbox-(load|save)-%s* is set!  "
 604                   "Treating as plain text!"), ext);
 605                goto jraw;
 606             } else
 607                goto jraw;
 608          }
 609       } else {
 610 jraw:
 611          /*flags |= FP_RAW;*/
 612          rv = Fopen(file, oflags);
 613          goto jleave;
 614       }
 615
 616       if ((infd = open(file, (mode & W_OK) ? O_RDWR : O_RDONLY)) == -1 &&
 617             (!(osflags & O_CREAT) || errno != ENOENT))
 618          goto jleave;
 619    }
 620
 621    /* Note rv is not yet register_file()d, fclose() it in error path! */
 622    if ((rv = Ftmp(NULL, "zopen", rof)) == NULL) {
 623       n_perr(_("tmpfile"), 0);
 624       goto jerr;
 625    }
 626
 627    if (flags & FP_MAILDIR)
 628       ;
 629    else if (infd >= 0) {
 630       if (_file_load(flags, infd, fileno(rv), cload) < 0) {
 631 jerr:
 632          if (rv != NULL)
 633             fclose(rv);
 634          rv = NULL;
 635          if (infd >= 0)
 636             close(infd);
 637          goto jleave;
 638       }
 639    } else {
 640       if ((infd = creat(file, 0666)) == -1) {
 641          fclose(rv);
 642          rv = NULL;
 643          goto jleave;
 644       }
 645    }
 646
 647    if (infd >= 0)
 648       close(infd);
 649    fflush(rv);
 650
 651    if (!(osflags & O_APPEND))
 652       rewind(rv);
 653    if ((offset = ftell(rv)) == -1) {
 654       Fclose(rv);
 655       rv = NULL;
 656       goto jleave;
 657    }
 658
 659    register_file(rv, osflags, 0, flags, file, offset, csave, NULL);
 660 jleave:
 661    NYD_LEAVE;
 662    return rv;
 663 }
 664
 665 FL FILE *
 666 Ftmp(char **fn, char const *namehint, enum oflags oflags)
 667 {
 668    /* The 8 is arbitrary but leaves room for a six character suffix (the
 669     * POSIX minimum path length is 14, though we don't check that XXX).
 670     * 8 should be more than sufficient given that we use base64url encoding
 671     * for our random string */
 672    enum {_RANDCHARS = 8u};
 673
 674    char *cp_base, *cp;
 675    size_t maxname, xlen, i;
 676    char const *tmpdir;
 677    int osoflags, fd, e;
 678    bool_t relesigs;
 679    FILE *fp;
 680    NYD_ENTER;
 681
 682    assert(namehint != NULL);
 683    assert((oflags & OF_WRONLY) || (oflags & OF_RDWR));
 684    assert(!(oflags & OF_RDONLY));
 685    assert(!(oflags & OF_REGISTER_UNLINK) || (oflags & OF_REGISTER));
 686
 687    fp = NULL;
 688    relesigs = FAL0;
 689    e = 0;
 690    tmpdir = ok_vlook(TMPDIR);
 691    maxname = NAME_MAX;
 692 #ifdef HAVE_PATHCONF
 693    {  long pc;
 694
 695       if ((pc = pathconf(tmpdir, _PC_NAME_MAX)) != -1)
 696          maxname = (size_t)pc;
 697    }
 698 #endif
 699
 700    if ((oflags & OF_SUFFIX) && *namehint != '\0') {
 701       if ((xlen = strlen(namehint)) > maxname - _RANDCHARS) {
 702          errno = ENAMETOOLONG;
 703          goto jleave;
 704       }
 705    } else
 706       xlen = 0;
 707
 708    /* Prepare the template string once, then iterate over the random range */
 709    cp_base =
 710    cp = smalloc(strlen(tmpdir) + 1 + maxname +1);
 711    cp = sstpcpy(cp, tmpdir);
 712    *cp++ = '/';
 713    {
 714       char *x = sstpcpy(cp, VAL_UAGENT);
 715       *x++ = '-';
 716       if (!(oflags & OF_SUFFIX))
 717          x = sstpcpy(x, namehint);
 718
 719       i = PTR2SIZE(x - cp);
 720       if (i > maxname - xlen - _RANDCHARS) {
 721          size_t j = maxname - xlen - _RANDCHARS;
 722          x -= i - j;
 723          i = j;
 724       }
 725
 726       if ((oflags & OF_SUFFIX) && xlen > 0)
 727          memcpy(x + _RANDCHARS, namehint, xlen);
 728
 729       x[xlen + _RANDCHARS] = '\0';
 730       cp = x;
 731    }
 732
 733    osoflags = O_CREAT | O_EXCL | _O_CLOEXEC;
 734    osoflags |= (oflags & OF_WRONLY) ? O_WRONLY : O_RDWR;
 735    if (oflags & OF_APPEND)
 736       osoflags |= O_APPEND;
 737
 738    for (i = 0;; ++i) {
 739       memcpy(cp, getrandstring(_RANDCHARS), _RANDCHARS);
 740
 741       hold_all_sigs();
 742       relesigs = TRU1;
 743
 744       if ((fd = open(cp_base, osoflags, 0600)) != -1) {
 745          _CLOEXEC_SET(fd);
 746          break;
 747       }
 748       if (i >= FTMP_OPEN_TRIES) {
 749          e = errno;
 750          goto jfree;
 751       }
 752       relesigs = FAL0;
 753       rele_all_sigs();
 754    }
 755
 756    if (oflags & OF_REGISTER) {
 757       char const *osflags = (oflags & OF_RDWR ? "w+" : "w");
 758       int osflagbits;
 759
 760       scan_mode(osflags, &osflagbits); /* TODO osoflags&xy ?!!? */
 761       if ((fp = fdopen(fd, osflags)) != NULL)
 762          register_file(fp, osflagbits | _O_CLOEXEC, 0,
 763             (FP_RAW | (oflags & OF_REGISTER_UNLINK ? FP_UNLINK : 0)),
 764             cp_base, 0L, NULL, NULL);
 765    } else
 766       fp = fdopen(fd, (oflags & OF_RDWR ? "w+" : "w"));
 767
 768    if (fp == NULL || (oflags & OF_UNLINK)) {
 769       e = errno;
 770       unlink(cp_base);
 771       goto jfree;
 772    }
 773
 774    if (fn != NULL)
 775       *fn = cp_base;
 776    else
 777       free(cp_base);
 778 jleave:
 779    if (relesigs && (fp == NULL || !(oflags & OF_HOLDSIGS)))
 780       rele_all_sigs();
 781    if (fp == NULL)
 782       errno = e;
 783    NYD_LEAVE;
 784    return fp;
 785 jfree:
 786    if ((cp = cp_base) != NULL)
 787       free(cp);
 788    goto jleave;
 789 }
 790
 791 FL void
 792 Ftmp_release(char **fn)
 793 {
 794    char *cp;
 795    NYD_ENTER;
 796
 797    cp = *fn;
 798    *fn = NULL;
 799    if (cp != NULL) {
 800       unlink(cp);
 801       rele_all_sigs();
 802       free(cp);
 803    }
 804    NYD_LEAVE;
 805 }
 806
 807 FL void
 808 Ftmp_free(char **fn) /* TODO DROP: OF_REGISTER_FREEPATH! */
 809 {
 810    char *cp;
 811    NYD_ENTER;
 812
 813    cp = *fn;
 814    *fn = NULL;
 815    if (cp != NULL)
 816       free(cp);
 817    NYD_LEAVE;
 818 }
 819
 820 FL bool_t
 821 pipe_cloexec(int fd[2])
 822 {
 823    bool_t rv = FAL0;
 824    NYD_ENTER;
 825
 826 #ifdef HAVE_PIPE2
 827    if (pipe2(fd, O_CLOEXEC) == -1)
 828       goto jleave;
 829 #else
 830    if (pipe(fd) == -1)
 831       goto jleave;
 832    (void)fcntl(fd[0], F_SETFD, FD_CLOEXEC);
 833    (void)fcntl(fd[1], F_SETFD, FD_CLOEXEC);
 834 #endif
 835    rv = TRU1;
 836 jleave:
 837    NYD_LEAVE;
 838    return rv;
 839 }
 840
 841 FL FILE *
 842 Popen(char const *cmd, char const *mode, char const *sh,
 843    char const **env_addon, int newfd1)
 844 {
 845    struct termios *tiosp;
 846    int p[2], myside, hisside, fd0, fd1, pid;
 847    char mod[2] = {'0', '\0'};
 848    sigset_t nset;
 849    FILE *rv = NULL;
 850    NYD_ENTER;
 851
 852    /* First clean up child structures */
 853    {  sigset_t oset;
 854       struct child **cpp, *cp;
 855
 856       sigfillset(&nset);
 857       sigprocmask(SIG_BLOCK, &nset, &oset);
 858
 859       for (cpp = &_popen_child; *cpp != NULL;) {
 860          if ((*cpp)->pid == -1) {
 861             cp = *cpp;
 862             *cpp = cp->link;
 863             free(cp);
 864          } else
 865             cpp = &(*cpp)->link;
 866       }
 867
 868       sigprocmask(SIG_SETMASK, &oset, NULL);
 869    }
 870
 871    if (!pipe_cloexec(p))
 872       goto jleave;
 873
 874    if (*mode == 'r') {
 875       myside = p[READ];
 876       fd0 = COMMAND_FD_PASS;
 877       hisside = fd1 = p[WRITE];
 878       mod[0] = *mode;
 879    } else if (*mode == 'W') {
 880       myside = p[WRITE];
 881       hisside = fd0 = p[READ];
 882       fd1 = newfd1;
 883       mod[0] = 'w';
 884    } else {
 885       myside = p[WRITE];
 886       hisside = fd0 = p[READ];
 887       fd1 = COMMAND_FD_PASS;
 888       mod[0] = 'w';
 889    }
 890
 891    /* In interactive mode both STDIN and STDOUT point to the terminal.  If we
 892     * pass through the TTY restore terminal attributes after pipe returns.
 893     * XXX It shouldn't matter which FD we actually use in this case */
 894    if ((options & OPT_INTERACTIVE) && (fd0 == COMMAND_FD_PASS ||
 895          fd1 == COMMAND_FD_PASS)) {
 896       tiosp = smalloc(sizeof *tiosp);
 897       tcgetattr(STDIN_FILENO, tiosp);
 898       n_TERMCAP_SUSPEND(TRU1);
 899    } else
 900       tiosp = NULL;
 901
 902    sigemptyset(&nset);
 903
 904    if (cmd == (char*)-1) {
 905       if ((pid = fork_child()) == -1)
 906          n_perr(_("fork"), 0);
 907       else if (pid == 0) {
 908          union {char const *ccp; int (*ptf)(void); int es;} u;
 909          prepare_child(&nset, fd0, fd1);
 910          close(p[READ]);
 911          close(p[WRITE]);
 912          u.ccp = sh;
 913          u.es = (*u.ptf)();
 914          _exit(u.es);
 915       }
 916    } else if (sh == NULL) {
 917       pid = start_command(cmd, &nset, fd0, fd1, NULL, NULL, NULL, env_addon);
 918    } else {
 919       pid = start_command(sh, &nset, fd0, fd1, "-c", cmd, NULL, env_addon);
 920    }
 921    if (pid < 0) {
 922       close(p[READ]);
 923       close(p[WRITE]);
 924       goto jleave;
 925    }
 926    close(hisside);
 927    if ((rv = fdopen(myside, mod)) != NULL)
 928       register_file(rv, 0, pid,
 929          (tiosp == NULL ? FP_PIPE : FP_PIPE | FP_TERMIOS),
 930          NULL, 0L, NULL, tiosp);
 931    else
 932       close(myside);
 933 jleave:
 934    NYD_LEAVE;
 935    return rv;
 936 }
 937
 938 FL bool_t
 939 Pclose(FILE *ptr, bool_t dowait)
 940 {
 941    struct termios *tiosp;
 942    sigset_t nset, oset;
 943    int pid;
 944    bool_t rv = FAL0;
 945    NYD_ENTER;
 946
 947    pid = file_pid(ptr);
 948    if (pid < 0)
 949       goto jleave;
 950
 951    unregister_file(ptr, &tiosp);
 952    fclose(ptr);
 953
 954    if (dowait) {
 955       sigemptyset(&nset);
 956       sigaddset(&nset, SIGINT);
 957       sigaddset(&nset, SIGHUP);
 958       sigprocmask(SIG_BLOCK, &nset, &oset);
 959       rv = wait_child(pid, NULL);
 960       if (tiosp != NULL) {
 961          n_TERMCAP_RESUME(TRU1);
 962          tcsetattr(STDIN_FILENO, TCSAFLUSH, tiosp);
 963       }
 964       sigprocmask(SIG_SETMASK, &oset, NULL);
 965    } else {
 966       free_child(pid);
 967       rv = TRU1;
 968    }
 969    if (tiosp != NULL)
 970       free(tiosp);
 971 jleave:
 972    NYD_LEAVE;
 973    return rv;
 974 }
 975
 976 FL FILE *
 977 n_pager_open(void)
 978 {
 979    char const *env_add[2], *pager;
 980    FILE *rv;
 981    NYD_ENTER;
 982
 983    assert(options & OPT_INTERACTIVE);
 984
 985    pager = n_pager_get(env_add + 0);
 986    env_add[1] = NULL;
 987
 988    if ((rv = Popen(pager, "w", NULL, env_add, COMMAND_FD_PASS)) == NULL)
 989       n_perr(pager, 0);
 990    NYD_LEAVE;
 991    return rv;
 992 }
 993
 994 FL bool_t
 995 n_pager_close(FILE *fp)
 996 {
 997    sighandler_type sh;
 998    bool_t rv;
 999    NYD_ENTER;
1000
1001    sh = safe_signal(SIGPIPE, SIG_IGN);
1002    rv = Pclose(fp, TRU1);
1003    safe_signal(SIGPIPE, sh);
1004    NYD_LEAVE;
1005    return rv;
1006 }
1007
1008 FL void
1009 close_all_files(void)
1010 {
1011    NYD_ENTER;
1012    while (fp_head != NULL)
1013       if ((fp_head->flags & FP_MASK) == FP_PIPE)
1014          Pclose(fp_head->fp, TRU1);
1015       else
1016          Fclose(fp_head->fp);
1017    NYD_LEAVE;
1018 }
1019
1020 FL int
1021 fork_child(void)
1022 {
1023    struct child *cp;
1024    int pid;
1025    NYD_ENTER;
1026
1027    cp = _findchild(0, TRU1);
1028
1029    if ((cp->pid = pid = fork()) == -1) {
1030       _delchild(cp);
1031       n_perr(_("fork"), 0);
1032    }
1033    NYD_LEAVE;
1034    return pid;
1035 }
1036
1037 FL int
1038 run_command(char const *cmd, sigset_t *mask, int infd, int outfd,
1039    char const *a0, char const *a1, char const *a2, char const **env_addon)
1040 {
1041    sigset_t nset, oset;
1042    sighandler_t soldint;
1043    bool_t tio_set;
1044    int rv;
1045    NYD_ENTER;
1046
1047    /* TODO Of course this is a joke given that during a "p*" the PAGER may
1048     * TODO be up and running while we play around like this... but i guess
1049     * TODO this can't be helped at all unless we perform complete and true
1050     * TODO process group separation and ensure we don't deadlock us out
1051     * TODO via TTY jobcontrol signal storms (could this really happen?).
1052     * TODO Or have a builtin pager.  Or query any necessity BEFORE we start
1053     * TODO any action, and shall we find we need to run programs dump it
1054     * TODO all into a temporary file which is then passed through to the
1055     * TODO PAGER.  Ugh.  That still won't help for "needsterminal" anyway */
1056    if ((tio_set = ((options & OPT_INTERACTIVE) &&
1057          (infd == COMMAND_FD_PASS || outfd == COMMAND_FD_PASS)))) {
1058       /* TODO Simply ignore SIGINT then, it surely will be ment for the program
1059        * TODO which takes the terminal */
1060       soldint = safe_signal(SIGINT, SIG_IGN);
1061       tcgetattr((options & OPT_TTYIN ? STDIN_FILENO : STDOUT_FILENO), &a_popen_tios);
1062       n_TERMCAP_SUSPEND(FAL0);
1063       sigfillset(&nset);
1064       sigdelset(&nset, SIGCHLD);
1065       sigdelset(&nset, SIGINT);
1066       /* sigdelset(&nset, SIGPIPE); TODO would need a handler */
1067       sigprocmask(SIG_BLOCK, &nset, &oset);
1068       a_popen_hadsig = 0;
1069       a_popen_jobsigs_up();
1070    }
1071
1072    if ((rv = start_command(cmd, mask, infd, outfd, a0, a1, a2, env_addon)) < 0)
1073       rv = -1;
1074    else {
1075       if (wait_child(rv, NULL))
1076          rv = 0;
1077       else {
1078          if (ok_blook(bsdcompat) || ok_blook(bsdmsgs))
1079             n_err(_("Fatal error in process\n"));
1080          rv = -1;
1081       }
1082    }
1083
1084    if (tio_set) {
1085       a_popen_jobsigs_down();
1086       tio_set = ((options & OPT_TTYIN) != 0);
1087       n_TERMCAP_RESUME(a_popen_hadsig ? TRU1 : FAL0);
1088       tcsetattr((tio_set ? STDIN_FILENO : STDOUT_FILENO),
1089          (tio_set ? TCSAFLUSH : TCSADRAIN), &a_popen_tios);
1090       if(soldint != SIG_IGN)
1091          safe_signal(SIGINT, soldint);
1092       sigprocmask(SIG_SETMASK, &oset, NULL);
1093    }
1094    NYD_LEAVE;
1095    return rv;
1096 }
1097
1098 FL int
1099 start_command(char const *cmd, sigset_t *mask, int infd, int outfd,
1100    char const *a0, char const *a1, char const *a2,
1101    char const **env_addon)
1102 {
1103    int rv;
1104    NYD_ENTER;
1105
1106    if ((rv = fork_child()) == -1) {
1107       n_perr(_("fork"), 0);
1108       rv = -1;
1109    } else if (rv == 0) {
1110       char *argv[128];
1111       int i;
1112
1113       if (env_addon != NULL) { /* TODO env_addon; should have struct child */
1114          extern char **environ;
1115          size_t ei, ei_orig, ai, ai_orig;
1116          char **env;
1117
1118          /* TODO note we don't check the POSIX limit:
1119           * the total space used to store the environment and the arguments to
1120           * the process is limited to {ARG_MAX} bytes */
1121          for (ei = 0; environ[ei] != NULL; ++ei)
1122             ;
1123          ei_orig = ei;
1124          for (ai = 0; env_addon[ai] != NULL; ++ai)
1125             ;
1126          ai_orig = ai;
1127          env = ac_alloc(sizeof(*env) * (ei + ai +1));
1128          memcpy(env, environ, sizeof(*env) * ei);
1129
1130          /* Replace all those keys that yet exist */
1131          while (ai-- > 0) {
1132             char const *ee, *kvs;
1133             size_t kl;
1134
1135             ee = env_addon[ai];
1136             kvs = strchr(ee, '=');
1137             assert(kvs != NULL);
1138             kl = PTR2SIZE(kvs - ee);
1139             assert(kl > 0);
1140             for (ei = ei_orig; ei-- > 0;) {
1141                char const *ekvs = strchr(env[ei], '=');
1142                if (ekvs != NULL && kl == PTR2SIZE(ekvs - env[ei]) &&
1143                      !memcmp(ee, env[ei], kl)) {
1144                   env[ei] = n_UNCONST(ee);
1145                   env_addon[ai] = NULL;
1146                   break;
1147                }
1148             }
1149          }
1150
1151          /* And append the rest */
1152          for (ei = ei_orig, ai = ai_orig; ai-- > 0;)
1153             if (env_addon[ai] != NULL)
1154                env[ei++] = n_UNCONST(env_addon[ai]);
1155
1156          env[ei] = NULL;
1157          environ = env;
1158       }
1159
1160       i = (int)getrawlist(FAL0, argv, n_NELEM(argv), cmd, strlen(cmd));
1161
1162       if ((argv[i++] = n_UNCONST(a0)) != NULL &&
1163             (argv[i++] = n_UNCONST(a1)) != NULL &&
1164             (argv[i++] = n_UNCONST(a2)) != NULL)
1165          argv[i] = NULL;
1166       prepare_child(mask, infd, outfd);
1167       execvp(argv[0], argv);
1168       perror(argv[0]);
1169       _exit(EXIT_ERR);
1170    }
1171    NYD_LEAVE;
1172    return rv;
1173 }
1174
1175 FL void
1176 prepare_child(sigset_t *nset, int infd, int outfd)
1177 {
1178    int i;
1179    sigset_t fset;
1180    NYD_ENTER;
1181
1182    /* All file descriptors other than 0, 1, and 2 are supposed to be cloexec */
1183    /* TODO WHAT IS WITH STDERR_FILENO DAMN? */
1184    if ((i = (infd == COMMAND_FD_NULL)))
1185       infd = open("/dev/null", O_RDONLY);
1186    if (infd >= 0) {
1187       dup2(infd, STDIN_FILENO);
1188       if (i)
1189          close(infd);
1190    }
1191
1192    if ((i = (outfd == COMMAND_FD_NULL)))
1193       outfd = open("/dev/null", O_WRONLY);
1194    if (outfd >= 0) {
1195       dup2(outfd, STDOUT_FILENO);
1196       if (i)
1197          close(outfd);
1198    }
1199
1200    if (nset) {
1201       for (i = 1; i < NSIG; ++i)
1202          if (sigismember(nset, i))
1203             safe_signal(i, SIG_IGN);
1204       if (!sigismember(nset, SIGINT))
1205          safe_signal(SIGINT, SIG_DFL);
1206    }
1207
1208    sigemptyset(&fset);
1209    sigprocmask(SIG_SETMASK, &fset, NULL);
1210    NYD_LEAVE;
1211 }
1212
1213 FL void
1214 free_child(int pid)
1215 {
1216    sigset_t nset, oset;
1217    struct child *cp;
1218    NYD_ENTER;
1219
1220    sigemptyset(&nset);
1221    sigaddset(&nset, SIGCHLD);
1222    sigprocmask(SIG_BLOCK, &nset, &oset);
1223
1224    if ((cp = _findchild(pid, FAL0)) != NULL) {
1225       if (cp->done)
1226          _delchild(cp);
1227       else
1228          cp->free = 1;
1229    }
1230
1231    sigprocmask(SIG_SETMASK, &oset, NULL);
1232    NYD_LEAVE;
1233 }
1234
1235 FL bool_t
1236 wait_child(int pid, int *wait_status)
1237 {
1238    sigset_t nset, oset;
1239    struct child *cp;
1240    int ws;
1241    bool_t rv;
1242    NYD_ENTER;
1243
1244    sigemptyset(&nset);
1245    sigaddset(&nset, SIGCHLD);
1246    sigprocmask(SIG_BLOCK, &nset, &oset);
1247
1248    cp = _findchild(pid, FAL0);
1249    if (cp != NULL) {
1250       while (!cp->done)
1251          sigsuspend(&oset);
1252       ws = cp->status;
1253       _delchild(cp);
1254    } else
1255       ws = 0;
1256
1257    sigprocmask(SIG_SETMASK, &oset, NULL);
1258
1259    if (wait_status != NULL)
1260       *wait_status = ws;
1261    rv = (WIFEXITED(ws) && WEXITSTATUS(ws) == 0);
1262    NYD_LEAVE;
1263    return rv;
1264 }
1265
1266 /* s-it-mode */