usr.bin/patch/inp.c

   1 /*-
   2  * Copyright 1986, Larry Wall
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following condition is met:
   6  * 1. Redistributions of source code must retain the above copyright notice,
   7  * this condition and the following disclaimer.
   8  *
   9  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND ANY
  10  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  11  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  12  * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
  13  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  14  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  15  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  16  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  17  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  18  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  19  * SUCH DAMAGE.
  20  *
  21  * patch - a program to apply diffs to original files
  22  *
  23  * -C option added in 1998, original code by Marc Espie, based on FreeBSD
  24  * behaviour
  25  *
  26  * $OpenBSD: inp.c,v 1.36 2012/04/10 14:46:34 ajacoutot Exp $
  27  * $FreeBSD$
  28  */
  29
  30 #include <sys/types.h>
  31 #include <sys/file.h>
  32 #include <sys/stat.h>
  33 #include <sys/mman.h>
  34 #include <sys/wait.h>
  35
  36 #include <ctype.h>
  37 #include <errno.h>
  38 #include <libgen.h>
  39 #include <limits.h>
  40 #include <stddef.h>
  41 #include <stdio.h>
  42 #include <stdlib.h>
  43 #include <string.h>
  44 #include <unistd.h>
  45
  46 #include "common.h"
  47 #include "util.h"
  48 #include "pch.h"
  49 #include "inp.h"
  50
  51
  52 /* Input-file-with-indexable-lines abstract type */
  53
  54 static size_t   i_size;         /* size of the input file */
  55 static char     *i_womp;        /* plan a buffer for entire file */
  56 static char     **i_ptr;        /* pointers to lines in i_womp */
  57 static char     empty_line[] = { '\0' };
  58
  59 static int      tifd = -1;      /* plan b virtual string array */
  60 static char     *tibuf[2];      /* plan b buffers */
  61 static LINENUM  tiline[2] = {-1, -1};   /* 1st line in each buffer */
  62 static LINENUM  lines_per_buf;  /* how many lines per buffer */
  63 static int      tireclen;       /* length of records in tmp file */
  64
  65 static bool     rev_in_string(const char *);
  66 static bool     reallocate_lines(size_t *);
  67
  68 /* returns false if insufficient memory */
  69 static bool     plan_a(const char *);
  70
  71 static void     plan_b(const char *);
  72
  73 /* New patch--prepare to edit another file. */
  74
  75 void
  76 re_input(void)
  77 {
  78         if (using_plan_a) {
  79                 free(i_ptr);
  80                 i_ptr = NULL;
  81                 if (i_womp != NULL) {
  82                         munmap(i_womp, i_size);
  83                         i_womp = NULL;
  84                 }
  85                 i_size = 0;
  86         } else {
  87                 using_plan_a = true;    /* maybe the next one is smaller */
  88                 close(tifd);
  89                 tifd = -1;
  90                 free(tibuf[0]);
  91                 free(tibuf[1]);
  92                 tibuf[0] = tibuf[1] = NULL;
  93                 tiline[0] = tiline[1] = -1;
  94                 tireclen = 0;
  95         }
  96 }
  97
  98 /* Construct the line index, somehow or other. */
  99
 100 void
 101 scan_input(const char *filename)
 102 {
 103         if (!plan_a(filename))
 104                 plan_b(filename);
 105         if (verbose) {
 106                 say("Patching file %s using Plan %s...\n", filename,
 107                     (using_plan_a ? "A" : "B"));
 108         }
 109 }
 110
 111 static bool
 112 reallocate_lines(size_t *lines_allocated)
 113 {
 114         char    **p;
 115         size_t  new_size;
 116
 117         new_size = *lines_allocated * 3 / 2;
 118         p = realloc(i_ptr, (new_size + 2) * sizeof(char *));
 119         if (p == NULL) {        /* shucks, it was a near thing */
 120                 munmap(i_womp, i_size);
 121                 i_womp = NULL;
 122                 free(i_ptr);
 123                 i_ptr = NULL;
 124                 *lines_allocated = 0;
 125                 return false;
 126         }
 127         *lines_allocated = new_size;
 128         i_ptr = p;
 129         return true;
 130 }
 131
 132 /* Try keeping everything in memory. */
 133
 134 static bool
 135 plan_a(const char *filename)
 136 {
 137         int             ifd, statfailed, devnull, pstat;
 138         char            *p, *s, lbuf[INITLINELEN];
 139         struct stat     filestat;
 140         ptrdiff_t       sz;
 141         size_t          i;
 142         size_t          iline, lines_allocated;
 143         pid_t           pid;
 144         char            *argp[4] = {NULL};
 145
 146 #ifdef DEBUGGING
 147         if (debug & 8)
 148                 return false;
 149 #endif
 150
 151         if (filename == NULL || *filename == '\0')
 152                 return false;
 153
 154         statfailed = stat(filename, &filestat);
 155         if (statfailed && ok_to_create_file) {
 156                 if (verbose)
 157                         say("(Creating file %s...)\n", filename);
 158
 159                 /*
 160                  * in check_patch case, we still display `Creating file' even
 161                  * though we're not. The rule is that -C should be as similar
 162                  * to normal patch behavior as possible
 163                  */
 164                 if (check_only)
 165                         return true;
 166                 makedirs(filename, true);
 167                 close(creat(filename, 0666));
 168                 statfailed = stat(filename, &filestat);
 169         }
 170         if (statfailed && check_only)
 171                 fatal("%s not found, -C mode, can't probe further\n", filename);
 172         /* For nonexistent or read-only files, look for RCS versions.  */
 173
 174         if (statfailed ||
 175             /* No one can write to it.  */
 176             (filestat.st_mode & 0222) == 0 ||
 177             /* I can't write to it.  */
 178             ((filestat.st_mode & 0022) == 0 && filestat.st_uid != getuid())) {
 179                 char    *filebase, *filedir;
 180                 struct stat     cstat;
 181                 char *tmp_filename1, *tmp_filename2;
 182
 183                 tmp_filename1 = strdup(filename);
 184                 tmp_filename2 = strdup(filename);
 185                 if (tmp_filename1 == NULL || tmp_filename2 == NULL)
 186                         fatal("strdupping filename");
 187
 188                 filebase = basename(tmp_filename1);
 189                 filedir = dirname(tmp_filename2);
 190
 191 #define try(f, a1, a2, a3) \
 192         (snprintf(lbuf, sizeof(lbuf), f, a1, a2, a3), stat(lbuf, &cstat) == 0)
 193
 194                 /*
 195                  * else we can't write to it but it's not under a version
 196                  * control system, so just proceed.
 197                  */
 198                 if (try("%s/RCS/%s%s", filedir, filebase, RCSSUFFIX) ||
 199                     try("%s/RCS/%s%s", filedir, filebase, "") ||
 200                     try("%s/%s%s", filedir, filebase, RCSSUFFIX)) {
 201                         if (!statfailed) {
 202                                 if ((filestat.st_mode & 0222) != 0)
 203                                         /* The owner can write to it.  */
 204                                         fatal("file %s seems to be locked "
 205                                             "by somebody else under RCS\n",
 206                                             filename);
 207                                 /*
 208                                  * It might be checked out unlocked.  See if
 209                                  * it's safe to check out the default version
 210                                  * locked.
 211                                  */
 212                                 if (verbose)
 213                                         say("Comparing file %s to default "
 214                                             "RCS version...\n", filename);
 215
 216                                 switch (pid = fork()) {
 217                                 case -1:
 218                                         fatal("can't fork: %s\n",
 219                                             strerror(errno));
 220                                 case 0:
 221                                         devnull = open("/dev/null", O_RDONLY);
 222                                         if (devnull == -1) {
 223                                                 fatal("can't open /dev/null: %s",
 224                                                     strerror(errno));
 225                                         }
 226                                         (void)dup2(devnull, STDOUT_FILENO);
 227                                         argp[0] = strdup(RCSDIFF);
 228                                         argp[1] = strdup(filename);
 229                                         execv(RCSDIFF, argp);
 230                                         exit(127);
 231                                 }
 232                                 pid = waitpid(pid, &pstat, 0);
 233                                 if (pid == -1 || WEXITSTATUS(pstat) != 0) {
 234                                         fatal("can't check out file %s: "
 235                                             "differs from default RCS version\n",
 236                                             filename);
 237                                 }
 238                         }
 239
 240                         if (verbose)
 241                                 say("Checking out file %s from RCS...\n",
 242                                     filename);
 243
 244                         switch (pid = fork()) {
 245                         case -1:
 246                                 fatal("can't fork: %s\n", strerror(errno));
 247                         case 0:
 248                                 argp[0] = strdup(CHECKOUT);
 249                                 argp[1] = strdup("-l");
 250                                 argp[2] = strdup(filename);
 251                                 execv(CHECKOUT, argp);
 252                                 exit(127);
 253                         }
 254                         pid = waitpid(pid, &pstat, 0);
 255                         if (pid == -1 || WEXITSTATUS(pstat) != 0 ||
 256                             stat(filename, &filestat)) {
 257                                 fatal("can't check out file %s from RCS\n",
 258                                     filename);
 259                         }
 260                 } else if (statfailed) {
 261                         fatal("can't find %s\n", filename);
 262                 }
 263                 free(tmp_filename1);
 264                 free(tmp_filename2);
 265         }
 266
 267         filemode = filestat.st_mode;
 268         if (!S_ISREG(filemode))
 269                 fatal("%s is not a normal file--can't patch\n", filename);
 270         if ((uint64_t)filestat.st_size > SIZE_MAX) {
 271                 say("block too large to mmap\n");
 272                 return false;
 273         }
 274         i_size = (size_t)filestat.st_size;
 275         if (out_of_mem) {
 276                 set_hunkmax();  /* make sure dynamic arrays are allocated */
 277                 out_of_mem = false;
 278                 return false;   /* force plan b because plan a bombed */
 279         }
 280         if ((ifd = open(filename, O_RDONLY)) < 0)
 281                 pfatal("can't open file %s", filename);
 282
 283         if (i_size) {
 284                 i_womp = mmap(NULL, i_size, PROT_READ, MAP_PRIVATE, ifd, 0);
 285                 if (i_womp == MAP_FAILED) {
 286                         perror("mmap failed");
 287                         i_womp = NULL;
 288                         close(ifd);
 289                         return false;
 290                 }
 291         } else {
 292                 i_womp = NULL;
 293         }
 294
 295         close(ifd);
 296         if (i_size)
 297                 madvise(i_womp, i_size, MADV_SEQUENTIAL);
 298
 299         /* estimate the number of lines */
 300         lines_allocated = i_size / 25;
 301         if (lines_allocated < 100)
 302                 lines_allocated = 100;
 303
 304         if (!reallocate_lines(&lines_allocated))
 305                 return false;
 306
 307         /* now scan the buffer and build pointer array */
 308         iline = 1;
 309         i_ptr[iline] = i_womp;
 310         /* test for NUL too, to maintain the behavior of the original code */
 311         for (s = i_womp, i = 0; i < i_size && *s != '\0'; s++, i++) {
 312                 if (*s == '\n') {
 313                         if (iline == lines_allocated) {
 314                                 if (!reallocate_lines(&lines_allocated))
 315                                         return false;
 316                         }
 317                         /* these are NOT NUL terminated */
 318                         i_ptr[++iline] = s + 1;
 319                 }
 320         }
 321         /* if the last line contains no EOL, append one */
 322         if (i_size > 0 && i_womp[i_size - 1] != '\n') {
 323                 last_line_missing_eol = true;
 324                 /* fix last line */
 325                 sz = s - i_ptr[iline];
 326                 p = malloc(sz + 1);
 327                 if (p == NULL) {
 328                         free(i_ptr);
 329                         i_ptr = NULL;
 330                         munmap(i_womp, i_size);
 331                         i_womp = NULL;
 332                         return false;
 333                 }
 334
 335                 memcpy(p, i_ptr[iline], sz);
 336                 p[sz] = '\n';
 337                 i_ptr[iline] = p;
 338                 /* count the extra line and make it point to some valid mem */
 339                 i_ptr[++iline] = empty_line;
 340         } else
 341                 last_line_missing_eol = false;
 342
 343         input_lines = iline - 1;
 344
 345         /* now check for revision, if any */
 346
 347         if (revision != NULL) {
 348                 if (!rev_in_string(i_womp)) {
 349                         if (force) {
 350                                 if (verbose)
 351                                         say("Warning: this file doesn't appear "
 352                                             "to be the %s version--patching anyway.\n",
 353                                             revision);
 354                         } else if (batch) {
 355                                 fatal("this file doesn't appear to be the "
 356                                     "%s version--aborting.\n",
 357                                     revision);
 358                         } else {
 359                                 ask("This file doesn't appear to be the "
 360                                     "%s version--patch anyway? [n] ",
 361                                     revision);
 362                                 if (*buf != 'y')
 363                                         fatal("aborted\n");
 364                         }
 365                 } else if (verbose)
 366                         say("Good.  This file appears to be the %s version.\n",
 367                             revision);
 368         }
 369         return true;            /* plan a will work */
 370 }
 371
 372 /* Keep (virtually) nothing in memory. */
 373
 374 static void
 375 plan_b(const char *filename)
 376 {
 377         FILE    *ifp;
 378         size_t  i = 0, j, maxlen = 1;
 379         char    *p;
 380         bool    found_revision = (revision == NULL);
 381
 382         using_plan_a = false;
 383         if ((ifp = fopen(filename, "r")) == NULL)
 384                 pfatal("can't open file %s", filename);
 385         unlink(TMPINNAME);
 386         if ((tifd = open(TMPINNAME, O_EXCL | O_CREAT | O_WRONLY, 0666)) < 0)
 387                 pfatal("can't open file %s", TMPINNAME);
 388         while (fgets(buf, buf_size, ifp) != NULL) {
 389                 if (revision != NULL && !found_revision && rev_in_string(buf))
 390                         found_revision = true;
 391                 if ((i = strlen(buf)) > maxlen)
 392                         maxlen = i;     /* find longest line */
 393         }
 394         last_line_missing_eol = i > 0 && buf[i - 1] != '\n';
 395         if (last_line_missing_eol && maxlen == i)
 396                 maxlen++;
 397
 398         if (revision != NULL) {
 399                 if (!found_revision) {
 400                         if (force) {
 401                                 if (verbose)
 402                                         say("Warning: this file doesn't appear "
 403                                             "to be the %s version--patching anyway.\n",
 404                                             revision);
 405                         } else if (batch) {
 406                                 fatal("this file doesn't appear to be the "
 407                                     "%s version--aborting.\n",
 408                                     revision);
 409                         } else {
 410                                 ask("This file doesn't appear to be the %s "
 411                                     "version--patch anyway? [n] ",
 412                                     revision);
 413                                 if (*buf != 'y')
 414                                         fatal("aborted\n");
 415                         }
 416                 } else if (verbose)
 417                         say("Good.  This file appears to be the %s version.\n",
 418                             revision);
 419         }
 420         fseek(ifp, 0L, SEEK_SET);       /* rewind file */
 421         lines_per_buf = BUFFERSIZE / maxlen;
 422         tireclen = maxlen;
 423         tibuf[0] = malloc(BUFFERSIZE + 1);
 424         if (tibuf[0] == NULL)
 425                 fatal("out of memory\n");
 426         tibuf[1] = malloc(BUFFERSIZE + 1);
 427         if (tibuf[1] == NULL)
 428                 fatal("out of memory\n");
 429         for (i = 1;; i++) {
 430                 p = tibuf[0] + maxlen * (i % lines_per_buf);
 431                 if (i % lines_per_buf == 0)     /* new block */
 432                         if (write(tifd, tibuf[0], BUFFERSIZE) < BUFFERSIZE)
 433                                 pfatal("can't write temp file");
 434                 if (fgets(p, maxlen + 1, ifp) == NULL) {
 435                         input_lines = i - 1;
 436                         if (i % lines_per_buf != 0)
 437                                 if (write(tifd, tibuf[0], BUFFERSIZE) < BUFFERSIZE)
 438                                         pfatal("can't write temp file");
 439                         break;
 440                 }
 441                 j = strlen(p);
 442                 /* These are '\n' terminated strings, so no need to add a NUL */
 443                 if (j == 0 || p[j - 1] != '\n')
 444                         p[j] = '\n';
 445         }
 446         fclose(ifp);
 447         close(tifd);
 448         if ((tifd = open(TMPINNAME, O_RDONLY)) < 0)
 449                 pfatal("can't reopen file %s", TMPINNAME);
 450 }
 451
 452 /*
 453  * Fetch a line from the input file, \n terminated, not necessarily \0.
 454  */
 455 char *
 456 ifetch(LINENUM line, int whichbuf)
 457 {
 458         if (line < 1 || line > input_lines) {
 459                 if (warn_on_invalid_line) {
 460                         say("No such line %ld in input file, ignoring\n", line);
 461                         warn_on_invalid_line = false;
 462                 }
 463                 return NULL;
 464         }
 465         if (using_plan_a)
 466                 return i_ptr[line];
 467         else {
 468                 LINENUM offline = line % lines_per_buf;
 469                 LINENUM baseline = line - offline;
 470
 471                 if (tiline[0] == baseline)
 472                         whichbuf = 0;
 473                 else if (tiline[1] == baseline)
 474                         whichbuf = 1;
 475                 else {
 476                         tiline[whichbuf] = baseline;
 477
 478                         if (lseek(tifd, (off_t) (baseline / lines_per_buf *
 479                             BUFFERSIZE), SEEK_SET) < 0)
 480                                 pfatal("cannot seek in the temporary input file");
 481
 482                         if (read(tifd, tibuf[whichbuf], BUFFERSIZE) < 0)
 483                                 pfatal("error reading tmp file %s", TMPINNAME);
 484                 }
 485                 return tibuf[whichbuf] + (tireclen * offline);
 486         }
 487 }
 488
 489 /*
 490  * True if the string argument contains the revision number we want.
 491  */
 492 static bool
 493 rev_in_string(const char *string)
 494 {
 495         const char      *s;
 496         size_t          patlen;
 497
 498         if (revision == NULL)
 499                 return true;
 500         patlen = strlen(revision);
 501         if (strnEQ(string, revision, patlen) && isspace((unsigned char)string[patlen]))
 502                 return true;
 503         for (s = string; *s; s++) {
 504                 if (isspace((unsigned char)*s) && strnEQ(s + 1, revision, patlen) &&
 505                     isspace((unsigned char)s[patlen + 1])) {
 506                         return true;
 507                 }
 508         }
 509         return false;
 510 }