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