mdw@git.distorted.org.uk Git - fwd/blob - file.c

   1 /* -*-c-*-
   2  *
   3  * $Id: file.c,v 1.2 1999/10/22 22:47:13 mdw Exp $
   4  *
   5  * File source and target
   6  *
   7  * (c) 1999 Straylight/Edgeware
   8  */
   9
  10 /*----- Licensing notice --------------------------------------------------*
  11  *
  12  * This file is part of the `fw' port forwarder.
  13  *
  14  * `fw' is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU General Public License as published by
  16  * the Free Software Foundation; either version 2 of the License, or
  17  * (at your option) any later version.
  18  *
  19  * `fw' is distributed in the hope that it will be useful,
  20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22  * GNU General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU General Public License
  25  * along with `fw'; if not, write to the Free Software Foundation,
  26  * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  27  */
  28
  29 /*----- Revision history --------------------------------------------------*
  30  *
  31  * $Log: file.c,v $
  32  * Revision 1.2  1999/10/22 22:47:13  mdw
  33  * New (empty) endpoint method required.
  34  *
  35  * Revision 1.1  1999/07/26 23:33:32  mdw
  36  * New sources and targets.
  37  *
  38  */
  39
  40 /*----- Header files ------------------------------------------------------*/
  41
  42 #include "config.h"
  43
  44 #include <ctype.h>
  45 #include <errno.h>
  46 #include <stdio.h>
  47 #include <stdlib.h>
  48 #include <string.h>
  49
  50 #include <sys/types.h>
  51 #include <sys/stat.h>
  52 #include <unistd.h>
  53 #include <fcntl.h>
  54
  55 #include <mLib/alloc.h>
  56 #include <mLib/dstr.h>
  57 #include <mLib/fdflags.h>
  58 #include <mLib/sub.h>
  59
  60 #include "conf.h"
  61 #include "endpt.h"
  62 #include "fattr.h"
  63 #include "file.h"
  64 #include "fw.h"
  65 #include "reffd.h"
  66 #include "scan.h"
  67 #include "source.h"
  68 #include "target.h"
  69
  70 /*----- Data structures ---------------------------------------------------*/
  71
  72 /* --- File specification --- */
  73
  74 typedef struct fspec {
  75   unsigned type;
  76   union {
  77     reffd *fd;
  78     char *name;
  79   } u;
  80 } fspec;
  81
  82 #define FTYPE_GUESS 0u
  83 #define FTYPE_FD 1u
  84 #define FTYPE_NAME 2u
  85 #define FTYPE_NULL 3u
  86
  87 /* --- File options --- */
  88
  89 typedef struct fopts {
  90   unsigned of;
  91 } fopts;
  92
  93 /* --- File data block --- */
  94
  95 typedef struct fdata {
  96   fspec in, out;
  97   fattr fa;
  98   fopts fo;
  99 } fdata;
 100
 101 /* --- File source block --- */
 102
 103 typedef struct fsource {
 104   source s;
 105   fdata f;
 106 } fsource;
 107
 108 /* --- File target block --- */
 109
 110 typedef struct ftarget {
 111   target t;
 112   fdata f;
 113 } ftarget;
 114
 115 /*----- Static variables --------------------------------------------------*/
 116
 117 static fopts file_opts = { O_TRUNC };
 118
 119 static reffd *rstdin, *rstdout;
 120 static reffd *rnull;
 121
 122 /*----- File endpoint operations ------------------------------------------*/
 123
 124 /* --- @wclose@ --- */
 125
 126 static void fept_wclose(endpt *e)
 127 {
 128   if (e->out) {
 129     REFFD_DEC(e->out);
 130     e->out = 0;
 131   }
 132 }
 133
 134 /* --- @close@ --- */
 135
 136 static void fept_close(endpt *e)
 137 {
 138   if (e->in)
 139     REFFD_DEC(e->in);
 140   if (e->out)
 141     REFFD_DEC(e->out);
 142   fw_dec();
 143   DESTROY(e);
 144 }
 145
 146 /* --- Endpoint operations table --- */
 147
 148 static endpt_ops fept_ops = { 0, 0, fept_wclose, fept_close };
 149
 150 /*----- General operations on sources and targets -------------------------*/
 151
 152 /* --- @file_null@ --- *
 153  *
 154  * Arguments:   @void *p@ = an uninteresting argument
 155  *
 156  * Returns:     ---
 157  *
 158  * Use:         Removes the reference to @rnull@ when the file closes.
 159  */
 160
 161 static void file_null(void *p)
 162 {
 163   rnull = 0;
 164 }
 165
 166 /* --- @file_nullref@ --- *
 167  *
 168  * Arguments:   ---
 169  *
 170  * Returns:     A reference to a file descriptor open on /dev/null.
 171  *
 172  * Use:         Obtains a file descriptor for /dev/null.  The reference
 173  *              @rnull@ is `weak', so that I only have a descriptor open when
 174  *              I actually need one.
 175  */
 176
 177 static reffd *file_nullref(void)
 178 {
 179   if (rnull)
 180     REFFD_INC(rnull);
 181   else {
 182     int n;
 183     if ((n = open("/dev/null", O_RDWR)) < 0) {
 184       fw_log(-1, "couldn't open `/dev/null': %s", strerror(errno));
 185       return (0);
 186     }
 187     fdflags(n, O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC);
 188     rnull = reffd_init(n);
 189     reffd_handler(rnull, file_null, 0);
 190   }
 191   return (rnull);
 192 }
 193
 194 /* --- @file_fspec@ --- *
 195  *
 196  * Arguments:   @fspec *f@ = pointer to filespec to fill in
 197  *              @scanner *sc@ = pointer to scanner to read from
 198  *
 199  * Returns:     ---
 200  *
 201  * Use:         Reads in a file spec.
 202  */
 203
 204 static void file_fspec(fspec *f, scanner *sc)
 205 {
 206   int c = 0;
 207   unsigned type = FTYPE_GUESS;
 208   reffd *fd = 0;
 209
 210   /* --- Set up references to @stdin@ and @stdout@ --- */
 211
 212   if (!rstdin) {
 213     fdflags(STDIN_FILENO, O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC);
 214     fdflags(STDOUT_FILENO, O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC);
 215     rstdin = reffd_init(STDIN_FILENO);
 216     rstdout = reffd_init(STDOUT_FILENO);
 217   }
 218
 219   /* --- Try to get an access type --- */
 220
 221   if (sc->t == ':') {
 222     c = 1;
 223     token(sc);
 224   }
 225
 226   if (sc->t == CTOK_WORD) {
 227     int i = conf_enum(sc, "fd,name,null", c ? ENUM_ABBREV : ENUM_NONE,
 228                       "file access type");
 229     type = i + 1;
 230     if (type && sc->t == ':')
 231       token(sc);
 232   }
 233
 234   /* --- Check for a valid file descriptor name --- */
 235
 236   if (sc->t == CTOK_WORD && type != FTYPE_NAME && type != FTYPE_NULL) {
 237     if (strcmp(sc->d.buf, "stdin") == 0) {
 238       fd = rstdin;
 239       REFFD_INC(rstdin);
 240     } else if (strcmp(sc->d.buf, "stdout") == 0) {
 241       fd = rstdout;
 242       REFFD_INC(rstdout);
 243     }
 244     if (fd)
 245       REFFD_INC(fd);
 246     else if (isdigit((unsigned char)*sc->d.buf)) {
 247       int nfd = atoi(sc->d.buf);
 248       switch (nfd) {
 249         case STDIN_FILENO: fd = rstdin; REFFD_INC(rstdin); break;
 250         case STDOUT_FILENO: fd = rstdout; REFFD_INC(rstdout); break;
 251         default:
 252           fd = reffd_init(nfd);
 253           fdflags(nfd, O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC);
 254           break;
 255       }
 256     }
 257   }
 258
 259   /* --- Sort out what to do as a result --- */
 260
 261   if (type == FTYPE_NULL)
 262     f->type = FTYPE_NULL;
 263   else if (fd) {
 264     f->type = FTYPE_FD;
 265     f->u.fd = fd;
 266     token(sc);
 267   } else if (type == FTYPE_FD) {
 268     if (sc->t == CTOK_WORD)
 269       error(sc, "bad file descriptor `%s'", sc->d.buf);
 270     else
 271       error(sc, "parse error, expected file descriptor");
 272   } else {
 273     dstr d = DSTR_INIT;
 274     conf_name(sc, '/', &d);
 275     f->type = FTYPE_NAME;
 276     f->u.name = xstrdup(d.buf);
 277     dstr_destroy(&d);
 278   }
 279 }
 280
 281 /* --- @read@ --- */
 282
 283 static void file_read(fdata *f, scanner *sc)
 284 {
 285   file_fspec(&f->in, sc);
 286   if (sc->t != ',') {
 287     f->out = f->in;
 288     if (f->out.type == FTYPE_FD && f->out.u.fd == rstdin)
 289       f->out.u.fd = rstdout;
 290   } else {
 291     token(sc);
 292     file_fspec(&f->out, sc);
 293   }
 294   f->fa = fattr_global;
 295   f->fo = file_opts;
 296 }
 297
 298 /* --- @print@ --- */
 299
 300 static void file_pfspec(fspec *f, dstr *d)
 301 {
 302   switch (f->type) {
 303     case FTYPE_FD:
 304       switch (f->u.fd->fd) {
 305         case STDIN_FILENO:
 306           dstr_puts(d, "stdin");
 307           break;
 308         case STDOUT_FILENO:
 309           dstr_puts(d, "stdout");
 310           break;
 311         default:
 312           dstr_putf(d, "fd:%i", f->u.fd->fd);
 313           break;
 314       }
 315       break;
 316     case FTYPE_NAME:
 317       dstr_putf(d, "name:%s", f->u.name);
 318       break;
 319     case FTYPE_NULL:
 320       dstr_puts(d, "null");
 321       break;
 322   }
 323 }
 324
 325 static void file_desc(fdata *f, dstr *d)
 326 {
 327   dstr_puts(d, "file ");
 328   file_pfspec(&f->in, d);
 329   dstr_puts(d, ", ");
 330   file_pfspec(&f->out, d);
 331 }
 332
 333 /* --- @option@ --- */
 334
 335 static int file_option(fdata *f, scanner *sc)
 336 {
 337   fopts *fo = f ? &f->fo : &file_opts;
 338
 339   CONF_BEGIN(sc, "file", "file")
 340
 341   /* --- Handle file-specific options --- */
 342
 343   if (strcmp(sc->d.buf, "create") == 0) {
 344     token(sc);
 345     if (sc->t == '=')
 346       token(sc);
 347     switch (conf_enum(sc, "no,yes", ENUM_ABBREV, "create status")) {
 348       case 0: fo->of &= ~O_CREAT; break;
 349       case 1: fo->of |= O_CREAT; break;
 350     }
 351     CONF_ACCEPT;
 352   }
 353
 354   else if (strcmp(sc->d.buf, "open") == 0) {
 355     token(sc);
 356     if (sc->t == '=')
 357       token(sc);
 358     fo->of &= ~(O_TRUNC | O_APPEND | O_EXCL);
 359     switch (conf_enum(sc, "no,truncate,append",
 360                       ENUM_ABBREV, "open status")) {
 361       case 0: fo->of |= O_EXCL; break;
 362       case 1: fo->of |= O_TRUNC; break;
 363       case 2: fo->of |= O_APPEND; break;
 364     }
 365     CONF_ACCEPT;
 366   }
 367
 368   /* --- See if it's a file attribute --- */
 369
 370   {
 371     fattr *fa = f ? &f->fa : &fattr_global;
 372     if (fattr_option(sc, fa))
 373       CONF_ACCEPT;
 374   }
 375
 376   /* --- Nobody understood it --- */
 377
 378   CONF_END;
 379 }
 380
 381 /* --- @endpt@ --- */
 382
 383 static endpt *file_endpt(fdata *f, const char *desc)
 384 {
 385   reffd *in = 0, *out = 0;
 386   endpt *e;
 387
 388   /* --- Make the input file first --- */
 389
 390   switch (f->in.type) {
 391     case FTYPE_NULL:
 392       in = file_nullref();
 393       break;
 394     case FTYPE_FD:
 395       in = f->in.u.fd;
 396       REFFD_INC(in);
 397       break;
 398     case FTYPE_NAME: {
 399       int fd;
 400       if ((fd = open(f->in.u.name, O_RDONLY | O_NONBLOCK)) < 0) {
 401         fw_log(-1, "[%s] couldn't open `%s' for reading: %s",
 402                desc, f->in.u.name, strerror(errno));
 403         return (0);
 404       }
 405       in = reffd_init(fd);
 406     } break;
 407   }
 408
 409   /* --- Make the output file second --- */
 410
 411   switch (f->out.type) {
 412     case FTYPE_NULL:
 413       out = file_nullref();
 414       break;
 415     case FTYPE_FD:
 416       out = f->out.u.fd;
 417       REFFD_INC(out);
 418       break;
 419     case FTYPE_NAME: {
 420       int m = f->fo.of | O_WRONLY | O_NONBLOCK;
 421       int fd = -1;
 422
 423       /* --- First try creating the file --- *
 424        *
 425        * This lets me know whether to set the file attributes or not.  It
 426        * also stands a chance of noticing people playing silly beggars with
 427        * dangling symlinks.
 428        */
 429
 430       if ((m & O_CREAT) &&
 431           (fd = open(f->out.u.name, m | O_EXCL, f->fa.mode)) < 0 &&
 432           (errno != EEXIST || (m & O_EXCL))) {
 433         fw_log(-1, "[%s] couldn't create `%s': %s",
 434                desc, f->out.u.name, strerror(errno));
 435         REFFD_DEC(in);
 436         return (0);
 437       }
 438
 439       if (fd != -1) {
 440         if (fattr_apply(f->out.u.name, &f->fa)) {
 441           fw_log(-1, "[%s] couldn't apply file attributes: %s",
 442                  desc, f->out.u.name, strerror(errno));
 443         }
 444       } else if ((fd = open(f->out.u.name, m & ~O_CREAT)) < 0) {
 445         fw_log(-1, "[%s] couldn't open `%s': %s",
 446                desc, f->out.u.name, strerror(errno));
 447         REFFD_DEC(in);
 448         return (0);
 449       }
 450
 451       fdflags(fd, O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC);
 452       out = reffd_init(fd);
 453     } break;
 454   }
 455
 456   /* --- Set up the endpoint --- */
 457
 458   e = CREATE(endpt);
 459   e->ops = &fept_ops;
 460   e->other = 0;
 461   e->f = EPF_FILE;
 462   e->t = 0;
 463   e->in = in;
 464   e->out = out;
 465   fw_inc();
 466   return (e);
 467 }
 468
 469 /* --- @destroy@ --- */
 470
 471 static void file_destroy(fdata *f)
 472 {
 473   if (f->in.type == FTYPE_NAME)
 474     free(f->in.u.name);
 475   if (f->out.type == FTYPE_NAME)
 476     free(f->out.u.name);
 477 }
 478
 479 /*----- File source description -------------------------------------------*/
 480
 481 /* --- @option@ --- */
 482
 483 static int fsource_option(source *s, scanner *sc)
 484 {
 485   fsource *fs = (fsource *)s;
 486   return (file_option(fs ? &fs->f : 0, sc));
 487 }
 488
 489 /* --- @read@ --- */
 490
 491 static source *fsource_read(scanner *sc)
 492 {
 493   fsource *fs;
 494
 495   if (!conf_prefix(sc, "file"))
 496     return (0);
 497   fs = CREATE(fsource);
 498   fs->s.ops = &fsource_ops;
 499   fs->s.desc = 0;
 500   file_read(&fs->f, sc);
 501   return (&fs->s);
 502 }
 503
 504 /* --- @attach@ --- */
 505
 506 static void fsource_destroy(source */*s*/);
 507
 508 static void fsource_attach(source *s, scanner *sc, target *t)
 509 {
 510   fsource *fs = (fsource *)s;
 511   endpt *e, *ee;
 512
 513   /* --- Set up the source description string --- */
 514
 515   {
 516     dstr d = DSTR_INIT;
 517     file_desc(&fs->f, &d);
 518     dstr_puts(&d, " -> ");
 519     dstr_puts(&d, t->desc);
 520     fs->s.desc = xstrdup(d.buf);
 521     dstr_destroy(&d);
 522   }
 523
 524   /* --- And then create the endpoints --- */
 525
 526   if ((ee = t->ops->create(t, fs->s.desc)) == 0)
 527     goto tidy;
 528   if ((e = file_endpt(&fs->f, fs->s.desc)) == 0) {
 529     ee->ops->close(ee);
 530     goto tidy;
 531   }
 532   endpt_join(e, ee);
 533
 534   /* --- Dispose of the source and target now --- */
 535
 536 tidy:
 537   t->ops->destroy(t);
 538   fsource_destroy(&fs->s);
 539 }
 540
 541 /* --- @destroy@ --- */
 542
 543 static void fsource_destroy(source *s)
 544 {
 545   fsource *fs = (fsource *)s;
 546
 547   /* free(fs->s.desc); */
 548   file_destroy(&fs->f);
 549   DESTROY(fs);
 550 }
 551
 552 /* --- File source operations --- */
 553
 554 source_ops fsource_ops = {
 555   "file",
 556   fsource_option, fsource_read, fsource_attach, fsource_destroy
 557 };
 558
 559 /*----- File target description -------------------------------------------*/
 560
 561 /* --- @option@ --- */
 562
 563 static int ftarget_option(target *t, scanner *sc)
 564 {
 565   ftarget *ft = (ftarget *)t;
 566   return (file_option(ft ? &ft->f : 0, sc));
 567 }
 568
 569 /* --- @read@ --- */
 570
 571 static target *ftarget_read(scanner *sc)
 572 {
 573   ftarget *ft;
 574   dstr d = DSTR_INIT;
 575
 576   if (!conf_prefix(sc, "file"))
 577     return (0);
 578   ft = CREATE(ftarget);
 579   ft->t.ops = &ftarget_ops;
 580   file_read(&ft->f, sc);
 581   file_desc(&ft->f, &d);
 582   ft->t.desc = xstrdup(d.buf);
 583   dstr_destroy(&d);
 584   return (&ft->t);
 585 }
 586
 587 /* --- @create@ --- */
 588
 589 static endpt *ftarget_create(target *t, const char *desc)
 590 {
 591   ftarget *ft = (ftarget *)t;
 592   endpt *e = file_endpt(&ft->f, desc);
 593   return (e);
 594 }
 595
 596 /* --- @destroy@ --- */
 597
 598 static void ftarget_destroy(target *t)
 599 {
 600   ftarget *ft = (ftarget *)t;
 601   file_destroy(&ft->f);
 602   /* free(ft->t.desc); */
 603   DESTROY(ft);
 604 }
 605
 606 /* --- File target operations --- */
 607
 608 target_ops ftarget_ops = {
 609   "file",
 610   ftarget_option, ftarget_read, ftarget_create, ftarget_destroy
 611 };
 612
 613 /*----- That's all, folks -------------------------------------------------*/