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