patch_cmds/patch/inp.c

   1 /*      $OpenBSD: inp.c,v 1.35 2009/10/27 23:59:41 deraadt Exp $        */
   2
   3 /*
   4  * patch - a program to apply diffs to original files
   5  *
   6  * Copyright 1986, Larry Wall
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following condition is met:
  10  * 1. Redistributions of source code must retain the above copyright notice,
  11  * this condition and the following disclaimer.
  12  *
  13  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND ANY
  14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  15  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  16  * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
  17  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  18  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  19  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  20  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  21  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  22  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  23  * SUCH DAMAGE.
  24  *
  25  * -C option added in 1998, original code by Marc Espie, based on FreeBSD
  26  * behaviour
  27  */
  28
  29 #include <sys/types.h>
  30 #include <sys/file.h>
  31 #include <sys/stat.h>
  32 #include <sys/mman.h>
  33
  34 #include <ctype.h>
  35 #include <libgen.h>
  36 #include <limits.h>
  37 #include <stddef.h>
  38 #include <stdio.h>
  39 #include <stdlib.h>
  40 #include <string.h>
  41 #include <unistd.h>
  42
  43 #include "common.h"
  44 #include "util.h"
  45 #include "pch.h"
  46 #include "inp.h"
  47
  48
  49 /* Input-file-with-indexable-lines abstract type */
  50
  51 static off_t    i_size;         /* size of the input file */
  52 static char     *i_womp;        /* plan a buffer for entire file */
  53 static char     **i_ptr;        /* pointers to lines in i_womp */
  54
  55 static int      tifd = -1;      /* plan b virtual string array */
  56 static char     *tibuf[2];      /* plan b buffers */
  57 static LINENUM  tiline[2] = {-1, -1};   /* 1st line in each buffer */
  58 static LINENUM  lines_per_buf;  /* how many lines per buffer */
  59 static int      tireclen;       /* length of records in tmp file */
  60
  61 static bool     rev_in_string(const char *);
  62 static bool     reallocate_lines(size_t *);
  63
  64 /* returns false if insufficient memory */
  65 static bool     plan_a(const char *);
  66
  67 static void     plan_b(const char *);
  68
  69 /* New patch--prepare to edit another file. */
  70
  71 void
  72 re_input(void)
  73 {
  74         if (using_plan_a) {
  75                 i_size = 0;
  76                 free(i_ptr);
  77                 i_ptr = NULL;
  78                 if (i_womp != NULL) {
  79                         munmap(i_womp, i_size);
  80                         i_womp = NULL;
  81                 }
  82         } else {
  83                 using_plan_a = true;    /* maybe the next one is smaller */
  84                 close(tifd);
  85                 tifd = -1;
  86                 free(tibuf[0]);
  87                 free(tibuf[1]);
  88                 tibuf[0] = tibuf[1] = NULL;
  89                 tiline[0] = tiline[1] = -1;
  90                 tireclen = 0;
  91         }
  92 }
  93
  94 /* Construct the line index, somehow or other. */
  95
  96 void
  97 scan_input(const char *filename)
  98 {
  99         if (!plan_a(filename))
 100                 plan_b(filename);
 101         if (verbose) {
 102                 say("Patching file %s using Plan %s...\n", filename,
 103                     (using_plan_a ? "A" : "B"));
 104         } else {
 105                 say("patching file %s\n", filename);
 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[MAXLINELEN];
 137         struct stat     filestat;
 138         off_t           i;
 139         ptrdiff_t       sz;
 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                 char    *cs = NULL, *filebase, *filedir;
 175                 struct stat     cstat;
 176
 177                 filebase = basename((char *)filename);
 178                 filedir = dirname((char *)filename);
 179
 180                 /* Leave room in lbuf for the diff command.  */
 181                 s = lbuf + 20;
 182
 183 #define try(f, a1, a2, a3) \
 184         (snprintf(s, sizeof lbuf - 20, f, a1, a2, a3), stat(s, &cstat) == 0)
 185
 186                 if (try("%s/RCS/%s%s", filedir, filebase, RCSSUFFIX) ||
 187                     try("%s/RCS/%s%s", filedir, filebase, "") ||
 188                     try("%s/%s%s", filedir, filebase, RCSSUFFIX)) {
 189                         snprintf(buf, sizeof buf, CHECKOUT, filename);
 190                         snprintf(lbuf, sizeof lbuf, RCSDIFF, filename);
 191                         cs = "RCS";
 192                 } else if (try("%s/SCCS/%s%s", filedir, SCCSPREFIX, filebase) ||
 193                     try("%s/%s%s", filedir, SCCSPREFIX, filebase)) {
 194                         snprintf(buf, sizeof buf, GET, s);
 195                         snprintf(lbuf, sizeof lbuf, SCCSDIFF, s, filename);
 196                         cs = "SCCS";
 197                 } else if (statfailed)
 198                         fatal("can't find %s\n", filename);
 199                 /*
 200                  * else we can't write to it but it's not under a version
 201                  * control system, so just proceed.
 202                  */
 203                 if (cs) {
 204                         if (!statfailed) {
 205                                 if ((filestat.st_mode & 0222) != 0)
 206                                         /* The owner can write to it.  */
 207                                         fatal("file %s seems to be locked "
 208                                             "by somebody else under %s\n",
 209                                             filename, cs);
 210                                 /*
 211                                  * It might be checked out unlocked.  See if
 212                                  * it's safe to check out the default version
 213                                  * locked.
 214                                  */
 215                                 if (verbose)
 216                                         say("Comparing file %s to default "
 217                                             "%s version...\n",
 218                                             filename, cs);
 219                                 if (system(lbuf))
 220                                         fatal("can't check out file %s: "
 221                                             "differs from default %s version\n",
 222                                             filename, cs);
 223                         }
 224                         if (verbose)
 225                                 say("Checking out file %s from %s...\n",
 226                                     filename, cs);
 227                         if (system(buf) || stat(filename, &filestat))
 228                                 fatal("can't check out file %s from %s\n",
 229                                     filename, cs);
 230                 }
 231         }
 232         filemode = filestat.st_mode;
 233         if (!S_ISREG(filemode))
 234                 fatal("%s is not a normal file--can't patch\n", filename);
 235         i_size = filestat.st_size;
 236         if (out_of_mem) {
 237                 set_hunkmax();  /* make sure dynamic arrays are allocated */
 238                 out_of_mem = false;
 239                 return false;   /* force plan b because plan a bombed */
 240         }
 241         if (i_size > SIZE_MAX) {
 242                 say("block too large to mmap\n");
 243                 return false;
 244         }
 245         if ((ifd = open(filename, O_RDONLY)) < 0)
 246                 pfatal("can't open file %s", filename);
 247
 248         i_womp = mmap(NULL, i_size == 0 ? 64 : i_size, PROT_READ, MAP_PRIVATE, ifd, 0);
 249         if (i_womp == MAP_FAILED) {
 250                 perror("mmap failed");
 251                 i_womp = NULL;
 252                 close(ifd);
 253                 return false;
 254         }
 255
 256         close(ifd);
 257         if (i_size)
 258                 madvise(i_womp, i_size, MADV_SEQUENTIAL);
 259
 260         /* estimate the number of lines */
 261         lines_allocated = i_size / 25;
 262         if (lines_allocated < 100)
 263                 lines_allocated = 100;
 264
 265         if (!reallocate_lines(&lines_allocated))
 266                 return false;
 267
 268         /* now scan the buffer and build pointer array */
 269         iline = 1;
 270         i_ptr[iline] = i_womp;
 271         /* test for NUL too, to maintain the behavior of the original code */
 272         for (s = i_womp, i = 0; i < i_size && *s != '\0'; s++, i++) {
 273                 if (*s == '\n') {
 274                         if (iline == lines_allocated) {
 275                                 if (!reallocate_lines(&lines_allocated))
 276                                         return false;
 277                         }
 278                         /* these are NOT NUL terminated */
 279                         i_ptr[++iline] = s + 1;
 280                 }
 281         }
 282         /* if the last line contains no EOL, append one */
 283         if (i_size > 0 && i_womp[i_size - 1] != '\n') {
 284                 last_line_missing_eol = true;
 285                 /* fix last line */
 286                 sz = s - i_ptr[iline];
 287                 p = malloc(sz + 1);
 288                 if (p == NULL) {
 289                         free(i_ptr);
 290                         i_ptr = NULL;
 291                         munmap(i_womp, i_size);
 292                         i_womp = NULL;
 293                         return false;
 294                 }
 295
 296                 memcpy(p, i_ptr[iline], sz);
 297                 p[sz] = '\n';
 298                 i_ptr[iline] = p;
 299                 /* count the extra line and make it point to some valid mem */
 300                 i_ptr[++iline] = "";
 301         } else
 302                 last_line_missing_eol = false;
 303
 304         input_lines = iline - 1;
 305
 306         /* now check for revision, if any */
 307
 308         if (revision != NULL) {
 309                 if (!rev_in_string(i_womp)) {
 310                         if (force) {
 311                                 if (verbose)
 312                                         say("Warning: this file doesn't appear "
 313                                             "to be the %s version--patching anyway.\n",
 314                                             revision);
 315                         } else if (batch) {
 316                                 fatal("this file doesn't appear to be the "
 317                                     "%s version--aborting.\n",
 318                                     revision);
 319                         } else {
 320                                 ask("This file doesn't appear to be the "
 321                                     "%s version--patch anyway? [n] ",
 322                                     revision);
 323                                 if (*buf != 'y')
 324                                         fatal("aborted\n");
 325                         }
 326                 } else if (verbose)
 327                         say("Good.  This file appears to be the %s version.\n",
 328                             revision);
 329         }
 330         return true;            /* plan a will work */
 331 }
 332
 333 /* Keep (virtually) nothing in memory. */
 334
 335 static void
 336 plan_b(const char *filename)
 337 {
 338         FILE    *ifp;
 339         size_t  i = 0, j, maxlen = 1;
 340         char    *p;
 341         bool    found_revision = (revision == NULL);
 342
 343         using_plan_a = false;
 344         if ((ifp = fopen(filename, "r")) == NULL)
 345                 pfatal("can't open file %s", filename);
 346         (void) unlink(TMPINNAME);
 347         if ((tifd = open(TMPINNAME, O_EXCL | O_CREAT | O_WRONLY, 0666)) < 0)
 348                 pfatal("can't open file %s", TMPINNAME);
 349         while (fgets(buf, sizeof buf, ifp) != NULL) {
 350                 if (revision != NULL && !found_revision && rev_in_string(buf))
 351                         found_revision = true;
 352                 if ((i = strlen(buf)) > maxlen)
 353                         maxlen = i;     /* find longest line */
 354         }
 355         last_line_missing_eol = i > 0 && buf[i - 1] != '\n';
 356         if (last_line_missing_eol && maxlen == i)
 357                 maxlen++;
 358
 359         if (revision != NULL) {
 360                 if (!found_revision) {
 361                         if (force) {
 362                                 if (verbose)
 363                                         say("Warning: this file doesn't appear "
 364                                             "to be the %s version--patching anyway.\n",
 365                                             revision);
 366                         } else if (batch) {
 367                                 fatal("this file doesn't appear to be the "
 368                                     "%s version--aborting.\n",
 369                                     revision);
 370                         } else {
 371                                 ask("This file doesn't appear to be the %s "
 372                                     "version--patch anyway? [n] ",
 373                                     revision);
 374                                 if (*buf != 'y')
 375                                         fatal("aborted\n");
 376                         }
 377                 } else if (verbose)
 378                         say("Good.  This file appears to be the %s version.\n",
 379                             revision);
 380         }
 381         fseek(ifp, 0L, SEEK_SET);       /* rewind file */
 382         lines_per_buf = BUFFERSIZE / maxlen;
 383         tireclen = maxlen;
 384         tibuf[0] = malloc(BUFFERSIZE + 1);
 385         if (tibuf[0] == NULL)
 386                 fatal("out of memory\n");
 387         tibuf[1] = malloc(BUFFERSIZE + 1);
 388         if (tibuf[1] == NULL)
 389                 fatal("out of memory\n");
 390         for (i = 1;; i++) {
 391                 p = tibuf[0] + maxlen * (i % lines_per_buf);
 392                 if (i % lines_per_buf == 0)     /* new block */
 393                         if (write(tifd, tibuf[0], BUFFERSIZE) < BUFFERSIZE)
 394                                 pfatal("can't write temp file");
 395                 if (fgets(p, maxlen + 1, ifp) == NULL) {
 396                         input_lines = i - 1;
 397                         if (i % lines_per_buf != 0)
 398                                 if (write(tifd, tibuf[0], BUFFERSIZE) < BUFFERSIZE)
 399                                         pfatal("can't write temp file");
 400                         break;
 401                 }
 402                 j = strlen(p);
 403                 /* These are '\n' terminated strings, so no need to add a NUL */
 404                 if (j == 0 || p[j - 1] != '\n')
 405                         p[j] = '\n';
 406         }
 407         fclose(ifp);
 408         close(tifd);
 409         if ((tifd = open(TMPINNAME, O_RDONLY)) < 0)
 410                 pfatal("can't reopen file %s", TMPINNAME);
 411 }
 412
 413 /*
 414  * Fetch a line from the input file, \n terminated, not necessarily \0.
 415  */
 416 char *
 417 ifetch(LINENUM line, int whichbuf)
 418 {
 419         if (line < 1 || line > input_lines) {
 420                 if (warn_on_invalid_line) {
 421                         say("No such line %ld in input file, ignoring\n", line);
 422                         warn_on_invalid_line = false;
 423                 }
 424                 return NULL;
 425         }
 426         if (using_plan_a)
 427                 return i_ptr[line];
 428         else {
 429                 LINENUM offline = line % lines_per_buf;
 430                 LINENUM baseline = line - offline;
 431
 432                 if (tiline[0] == baseline)
 433                         whichbuf = 0;
 434                 else if (tiline[1] == baseline)
 435                         whichbuf = 1;
 436                 else {
 437                         tiline[whichbuf] = baseline;
 438
 439                         if (lseek(tifd, (off_t) (baseline / lines_per_buf *
 440                             BUFFERSIZE), SEEK_SET) < 0)
 441                                 pfatal("cannot seek in the temporary input file");
 442
 443                         if (read(tifd, tibuf[whichbuf], BUFFERSIZE) < 0)
 444                                 pfatal("error reading tmp file %s", TMPINNAME);
 445                 }
 446                 return tibuf[whichbuf] + (tireclen * offline);
 447         }
 448 }
 449
 450 /*
 451  * True if the string argument contains the revision number we want.
 452  */
 453 static bool
 454 rev_in_string(const char *string)
 455 {
 456         const char      *s;
 457         size_t          patlen;
 458
 459         if (revision == NULL)
 460                 return true;
 461         patlen = strlen(revision);
 462         if (strnEQ(string, revision, patlen) && isspace(string[patlen]))
 463                 return true;
 464         for (s = string; *s; s++) {
 465                 if (isspace(*s) && strnEQ(s + 1, revision, patlen) &&
 466                     isspace(s[patlen + 1])) {
 467                         return true;
 468                 }
 469         }
 470         return false;
 471 }