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: head/usr.bin/patch/inp.c 246091 2013-01-29 20:05:16Z delphij $
  28  */
  29
  30 #include <sys/types.h>
  31 #include <sys/file.h>
  32 #include <sys/stat.h>
  33 #include <sys/mman.h>
  34
  35 #include <ctype.h>
  36 #include <libgen.h>
  37 #include <limits.h>
  38 #include <stddef.h>
  39 #include <stdio.h>
  40 #include <stdlib.h>
  41 #include <string.h>
  42 #include <unistd.h>
  43
  44 #include "common.h"
  45 #include "util.h"
  46 #include "pch.h"
  47 #include "inp.h"
  48
  49
  50 /* Input-file-with-indexable-lines abstract type */
  51
  52 static size_t   i_size;         /* size of the input file */
  53 static char     *i_womp;        /* plan a buffer for entire file */
  54 static char     **i_ptr;        /* pointers to lines in i_womp */
  55 static char     empty_line[] = { '\0' };
  56
  57 static int      tifd = -1;      /* plan b virtual string array */
  58 static char     *tibuf[2];      /* plan b buffers */
  59 static LINENUM  tiline[2] = {-1, -1};   /* 1st line in each buffer */
  60 static LINENUM  lines_per_buf;  /* how many lines per buffer */
  61 static int      tireclen;       /* length of records in tmp file */
  62
  63 static bool     rev_in_string(const char *);
  64 static bool     reallocate_lines(size_t *);
  65
  66 /* returns false if insufficient memory */
  67 static bool     plan_a(const char *);
  68
  69 static void     plan_b(const char *);
  70
  71 /* New patch--prepare to edit another file. */
  72
  73 void
  74 re_input(void)
  75 {
  76         if (using_plan_a) {
  77                 free(i_ptr);
  78                 i_ptr = NULL;
  79                 if (i_womp != NULL) {
  80                         munmap(i_womp, i_size);
  81                         i_womp = NULL;
  82                 }
  83                 i_size = 0;
  84         } else {
  85                 using_plan_a = true;    /* maybe the next one is smaller */
  86                 close(tifd);
  87                 tifd = -1;
  88                 free(tibuf[0]);
  89                 free(tibuf[1]);
  90                 tibuf[0] = tibuf[1] = NULL;
  91                 tiline[0] = tiline[1] = -1;
  92                 tireclen = 0;
  93         }
  94 }
  95
  96 /* Construct the line index, somehow or other. */
  97
  98 void
  99 scan_input(const char *filename)
 100 {
 101         if (!plan_a(filename))
 102                 plan_b(filename);
 103         if (verbose) {
 104                 say("Patching file %s using Plan %s...\n", filename,
 105                     (using_plan_a ? "A" : "B"));
 106         }
 107 }
 108
 109 static bool
 110 reallocate_lines(size_t *lines_allocated)
 111 {
 112         char    **p;
 113         size_t  new_size;
 114
 115         new_size = *lines_allocated * 3 / 2;
 116         p = realloc(i_ptr, (new_size + 2) * sizeof(char *));
 117         if (p == NULL) {        /* shucks, it was a near thing */
 118                 munmap(i_womp, i_size);
 119                 i_womp = NULL;
 120                 free(i_ptr);
 121                 i_ptr = NULL;
 122                 *lines_allocated = 0;
 123                 return false;
 124         }
 125         *lines_allocated = new_size;
 126         i_ptr = p;
 127         return true;
 128 }
 129
 130 /* Try keeping everything in memory. */
 131
 132 static bool
 133 plan_a(const char *filename)
 134 {
 135         int             ifd, statfailed;
 136         char            *p, *s, lbuf[INITLINELEN];
 137         struct stat     filestat;
 138         ptrdiff_t       sz;
 139         size_t          i;
 140         size_t          iline, lines_allocated;
 141
 142 #ifdef DEBUGGING
 143         if (debug & 8)
 144                 return false;
 145 #endif
 146
 147         if (filename == NULL || *filename == '\0')
 148                 return false;
 149
 150         statfailed = stat(filename, &filestat);
 151         if (statfailed && ok_to_create_file) {
 152                 if (verbose)
 153                         say("(Creating file %s...)\n", filename);
 154
 155                 /*
 156                  * in check_patch case, we still display `Creating file' even
 157                  * though we're not. The rule is that -C should be as similar
 158                  * to normal patch behavior as possible
 159                  */
 160                 if (check_only)
 161                         return true;
 162                 makedirs(filename, true);
 163                 close(creat(filename, 0666));
 164                 statfailed = stat(filename, &filestat);
 165         }
 166         if (statfailed && check_only)
 167                 fatal("%s not found, -C mode, can't probe further\n", filename);
 168         /* For nonexistent or read-only files, look for RCS or SCCS versions.  */
 169         if (statfailed ||
 170             /* No one can write to it.  */
 171             (filestat.st_mode & 0222) == 0 ||
 172             /* I can't write to it.  */
 173             ((filestat.st_mode & 0022) == 0 && filestat.st_uid != getuid())) {
 174                 const char      *cs = NULL, *filebase, *filedir;
 175                 struct stat     cstat;
 176                 char *tmp_filename1, *tmp_filename2;
 177
 178                 tmp_filename1 = strdup(filename);
 179                 tmp_filename2 = strdup(filename);
 180                 if (tmp_filename1 == NULL || tmp_filename2 == NULL)
 181                         fatal("strdupping filename");
 182                 filebase = basename(tmp_filename1);
 183                 filedir = dirname(tmp_filename2);
 184
 185                 /* Leave room in lbuf for the diff command.  */
 186                 s = lbuf + 20;
 187
 188 #define try(f, a1, a2, a3) \
 189         (snprintf(s, buf_size - 20, f, a1, a2, a3), stat(s, &cstat) == 0)
 190
 191                 if (try("%s/RCS/%s%s", filedir, filebase, RCSSUFFIX) ||
 192                     try("%s/RCS/%s%s", filedir, filebase, "") ||
 193                     try("%s/%s%s", filedir, filebase, RCSSUFFIX)) {
 194                         snprintf(buf, buf_size, CHECKOUT, filename);
 195                         snprintf(lbuf, sizeof lbuf, RCSDIFF, filename);
 196                         cs = "RCS";
 197                 } else if (try("%s/SCCS/%s%s", filedir, SCCSPREFIX, filebase) ||
 198                     try("%s/%s%s", filedir, SCCSPREFIX, filebase)) {
 199                         snprintf(buf, buf_size, GET, s);
 200                         snprintf(lbuf, sizeof lbuf, SCCSDIFF, s, filename);
 201                         cs = "SCCS";
 202                 } else if (statfailed)
 203                         fatal("can't find %s\n", filename);
 204
 205                 free(tmp_filename1);
 206                 free(tmp_filename2);
 207
 208                 /*
 209                  * else we can't write to it but it's not under a version
 210                  * control system, so just proceed.
 211                  */
 212                 if (cs) {
 213                         if (!statfailed) {
 214                                 if ((filestat.st_mode & 0222) != 0)
 215                                         /* The owner can write to it.  */
 216                                         fatal("file %s seems to be locked "
 217                                             "by somebody else under %s\n",
 218                                             filename, cs);
 219                                 /*
 220                                  * It might be checked out unlocked.  See if
 221                                  * it's safe to check out the default version
 222                                  * locked.
 223                                  */
 224                                 if (verbose)
 225                                         say("Comparing file %s to default "
 226                                             "%s version...\n",
 227                                             filename, cs);
 228                                 if (system(lbuf))
 229                                         fatal("can't check out file %s: "
 230                                             "differs from default %s version\n",
 231                                             filename, cs);
 232                         }
 233                         if (verbose)
 234                                 say("Checking out file %s from %s...\n",
 235                                     filename, cs);
 236                         if (system(buf) || stat(filename, &filestat))
 237                                 fatal("can't check out file %s from %s\n",
 238                                     filename, cs);
 239                 }
 240         }
 241         filemode = filestat.st_mode;
 242         if (!S_ISREG(filemode))
 243                 fatal("%s is not a normal file--can't patch\n", filename);
 244         if ((uint64_t)filestat.st_size > SIZE_MAX) {
 245                 say("block too large to mmap\n");
 246                 return false;
 247         }
 248         i_size = (size_t)filestat.st_size;
 249         if (out_of_mem) {
 250                 set_hunkmax();  /* make sure dynamic arrays are allocated */
 251                 out_of_mem = false;
 252                 return false;   /* force plan b because plan a bombed */
 253         }
 254         if ((ifd = open(filename, O_RDONLY)) < 0)
 255                 pfatal("can't open file %s", filename);
 256
 257         if (i_size) {
 258                 i_womp = mmap(NULL, i_size, PROT_READ, MAP_PRIVATE, ifd, 0);
 259                 if (i_womp == MAP_FAILED) {
 260                         perror("mmap failed");
 261                         i_womp = NULL;
 262                         close(ifd);
 263                         return false;
 264                 }
 265         } else {
 266                 i_womp = NULL;
 267         }
 268
 269         close(ifd);
 270         if (i_size)
 271                 madvise(i_womp, i_size, MADV_SEQUENTIAL);
 272
 273         /* estimate the number of lines */
 274         lines_allocated = i_size / 25;
 275         if (lines_allocated < 100)
 276                 lines_allocated = 100;
 277
 278         if (!reallocate_lines(&lines_allocated))
 279                 return false;
 280
 281         /* now scan the buffer and build pointer array */
 282         iline = 1;
 283         i_ptr[iline] = i_womp;
 284         /* test for NUL too, to maintain the behavior of the original code */
 285         for (s = i_womp, i = 0; i < i_size && *s != '\0'; s++, i++) {
 286                 if (*s == '\n') {
 287                         if (iline == lines_allocated) {
 288                                 if (!reallocate_lines(&lines_allocated))
 289                                         return false;
 290                         }
 291                         /* these are NOT NUL terminated */
 292                         i_ptr[++iline] = s + 1;
 293                 }
 294         }
 295         /* if the last line contains no EOL, append one */
 296         if (i_size > 0 && i_womp[i_size - 1] != '\n') {
 297                 last_line_missing_eol = true;
 298                 /* fix last line */
 299                 sz = s - i_ptr[iline];
 300                 p = malloc(sz + 1);
 301                 if (p == NULL) {
 302                         free(i_ptr);
 303                         i_ptr = NULL;
 304                         munmap(i_womp, i_size);
 305                         i_womp = NULL;
 306                         return false;
 307                 }
 308
 309                 memcpy(p, i_ptr[iline], sz);
 310                 p[sz] = '\n';
 311                 i_ptr[iline] = p;
 312                 /* count the extra line and make it point to some valid mem */
 313                 i_ptr[++iline] = empty_line;
 314         } else
 315                 last_line_missing_eol = false;
 316
 317         input_lines = iline - 1;
 318
 319         /* now check for revision, if any */
 320
 321         if (revision != NULL) {
 322                 if (!rev_in_string(i_womp)) {
 323                         if (force) {
 324                                 if (verbose)
 325                                         say("Warning: this file doesn't appear "
 326                                             "to be the %s version--patching anyway.\n",
 327                                             revision);
 328                         } else if (batch) {
 329                                 fatal("this file doesn't appear to be the "
 330                                     "%s version--aborting.\n",
 331                                     revision);
 332                         } else {
 333                                 ask("This file doesn't appear to be the "
 334                                     "%s version--patch anyway? [n] ",
 335                                     revision);
 336                                 if (*buf != 'y')
 337                                         fatal("aborted\n");
 338                         }
 339                 } else if (verbose)
 340                         say("Good.  This file appears to be the %s version.\n",
 341                             revision);
 342         }
 343         return true;            /* plan a will work */
 344 }
 345
 346 /* Keep (virtually) nothing in memory. */
 347
 348 static void
 349 plan_b(const char *filename)
 350 {
 351         FILE    *ifp;
 352         size_t  i = 0, j, maxlen = 1;
 353         char    *p;
 354         bool    found_revision = (revision == NULL);
 355
 356         using_plan_a = false;
 357         if ((ifp = fopen(filename, "r")) == NULL)
 358                 pfatal("can't open file %s", filename);
 359         unlink(TMPINNAME);
 360         if ((tifd = open(TMPINNAME, O_EXCL | O_CREAT | O_WRONLY, 0666)) < 0)
 361                 pfatal("can't open file %s", TMPINNAME);
 362         while (fgets(buf, buf_size, ifp) != NULL) {
 363                 if (revision != NULL && !found_revision && rev_in_string(buf))
 364                         found_revision = true;
 365                 if ((i = strlen(buf)) > maxlen)
 366                         maxlen = i;     /* find longest line */
 367         }
 368         last_line_missing_eol = i > 0 && buf[i - 1] != '\n';
 369         if (last_line_missing_eol && maxlen == i)
 370                 maxlen++;
 371
 372         if (revision != NULL) {
 373                 if (!found_revision) {
 374                         if (force) {
 375                                 if (verbose)
 376                                         say("Warning: this file doesn't appear "
 377                                             "to be the %s version--patching anyway.\n",
 378                                             revision);
 379                         } else if (batch) {
 380                                 fatal("this file doesn't appear to be the "
 381                                     "%s version--aborting.\n",
 382                                     revision);
 383                         } else {
 384                                 ask("This file doesn't appear to be the %s "
 385                                     "version--patch anyway? [n] ",
 386                                     revision);
 387                                 if (*buf != 'y')
 388                                         fatal("aborted\n");
 389                         }
 390                 } else if (verbose)
 391                         say("Good.  This file appears to be the %s version.\n",
 392                             revision);
 393         }
 394         fseek(ifp, 0L, SEEK_SET);       /* rewind file */
 395         lines_per_buf = BUFFERSIZE / maxlen;
 396         tireclen = maxlen;
 397         tibuf[0] = malloc(BUFFERSIZE + 1);
 398         if (tibuf[0] == NULL)
 399                 fatal("out of memory\n");
 400         tibuf[1] = malloc(BUFFERSIZE + 1);
 401         if (tibuf[1] == NULL)
 402                 fatal("out of memory\n");
 403         for (i = 1;; i++) {
 404                 p = tibuf[0] + maxlen * (i % lines_per_buf);
 405                 if (i % lines_per_buf == 0)     /* new block */
 406                         if (write(tifd, tibuf[0], BUFFERSIZE) < BUFFERSIZE)
 407                                 pfatal("can't write temp file");
 408                 if (fgets(p, maxlen + 1, ifp) == NULL) {
 409                         input_lines = i - 1;
 410                         if (i % lines_per_buf != 0)
 411                                 if (write(tifd, tibuf[0], BUFFERSIZE) < BUFFERSIZE)
 412                                         pfatal("can't write temp file");
 413                         break;
 414                 }
 415                 j = strlen(p);
 416                 /* These are '\n' terminated strings, so no need to add a NUL */
 417                 if (j == 0 || p[j - 1] != '\n')
 418                         p[j] = '\n';
 419         }
 420         fclose(ifp);
 421         close(tifd);
 422         if ((tifd = open(TMPINNAME, O_RDONLY)) < 0)
 423                 pfatal("can't reopen file %s", TMPINNAME);
 424 }
 425
 426 /*
 427  * Fetch a line from the input file, \n terminated, not necessarily \0.
 428  */
 429 char *
 430 ifetch(LINENUM line, int whichbuf)
 431 {
 432         if (line < 1 || line > input_lines) {
 433                 if (warn_on_invalid_line) {
 434                         say("No such line %ld in input file, ignoring\n", line);
 435                         warn_on_invalid_line = false;
 436                 }
 437                 return NULL;
 438         }
 439         if (using_plan_a)
 440                 return i_ptr[line];
 441         else {
 442                 LINENUM offline = line % lines_per_buf;
 443                 LINENUM baseline = line - offline;
 444
 445                 if (tiline[0] == baseline)
 446                         whichbuf = 0;
 447                 else if (tiline[1] == baseline)
 448                         whichbuf = 1;
 449                 else {
 450                         tiline[whichbuf] = baseline;
 451
 452                         if (lseek(tifd, (off_t) (baseline / lines_per_buf *
 453                             BUFFERSIZE), SEEK_SET) < 0)
 454                                 pfatal("cannot seek in the temporary input file");
 455
 456                         if (read(tifd, tibuf[whichbuf], BUFFERSIZE) < 0)
 457                                 pfatal("error reading tmp file %s", TMPINNAME);
 458                 }
 459                 return tibuf[whichbuf] + (tireclen * offline);
 460         }
 461 }
 462
 463 /*
 464  * True if the string argument contains the revision number we want.
 465  */
 466 static bool
 467 rev_in_string(const char *string)
 468 {
 469         const char      *s;
 470         size_t          patlen;
 471
 472         if (revision == NULL)
 473                 return true;
 474         patlen = strlen(revision);
 475         if (strnEQ(string, revision, patlen) && isspace((unsigned char)string[patlen]))
 476                 return true;
 477         for (s = string; *s; s++) {
 478                 if (isspace((unsigned char)*s) && strnEQ(s + 1, revision, patlen) &&
 479                     isspace((unsigned char)s[patlen + 1])) {
 480                         return true;
 481                 }
 482         }
 483         return false;
 484 }