libexec/rtld-aout/shlib.c

   1 /*
   2  * Copyright (c) 1993 Paul Kranenburg
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by Paul Kranenburg.
  16  * 4. The name of the author may not be used to endorse or promote products
  17  *    derived from this software without specific prior written permission
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  20  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  21  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  22  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  23  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  24  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  28  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  29  *
  30  * $FreeBSD$
  31  */
  32
  33 #include <sys/param.h>
  34 #include <sys/types.h>
  35 #include <sys/stat.h>
  36 #include <sys/file.h>
  37 #include <sys/time.h>
  38 #include <a.out.h>
  39 #include <ctype.h>
  40 #include <dirent.h>
  41 #include <err.h>
  42 #include <fcntl.h>
  43 #include <stdio.h>
  44 #include <stdlib.h>
  45 #include <string.h>
  46
  47 #include <sys/link_aout.h>
  48 #include "shlib.h"
  49 #include "support.h"
  50
  51 /*
  52  * Standard directories to search for files specified by -l.
  53  */
  54 #ifndef STANDARD_SEARCH_DIRS
  55 #define STANDARD_SEARCH_DIRS    "/usr/lib/aout"
  56 #endif
  57
  58 /*
  59  * Actual vector of library search directories,
  60  * including `-L'ed and LD_LIBRARY_PATH spec'd ones.
  61  */
  62 char     **search_dirs;
  63 int     n_search_dirs;
  64
  65 const char      *standard_search_dirs[] = {
  66         STANDARD_SEARCH_DIRS
  67 };
  68
  69
  70 void
  71 add_search_dir(const char *name)
  72 {
  73         int n;
  74
  75         for (n = 0; n < n_search_dirs; n++)
  76                 if (strcmp(search_dirs[n], name) == 0)
  77                         return;
  78         n_search_dirs++;
  79         search_dirs = (char **)
  80                 xrealloc(search_dirs, n_search_dirs * sizeof search_dirs[0]);
  81         search_dirs[n_search_dirs - 1] = strdup(name);
  82 }
  83
  84 void
  85 add_search_path(path)
  86 char    *path;
  87 {
  88         register char   *cp, *dup;
  89
  90         if (path == NULL)
  91                 return;
  92
  93         /* Add search directories from `path' */
  94         path = dup = strdup(path);
  95         while ((cp = strsep(&path, ":")) != NULL)
  96                 add_search_dir(cp);
  97         free(dup);
  98 }
  99
 100 void
 101 std_search_path()
 102 {
 103         int     i, n;
 104
 105         /* Append standard search directories */
 106         n = sizeof standard_search_dirs / sizeof standard_search_dirs[0];
 107         for (i = 0; i < n; i++)
 108                 add_search_dir(standard_search_dirs[i]);
 109 }
 110
 111 /*
 112  * Return true if CP points to a valid dewey number.
 113  * Decode and leave the result in the array DEWEY.
 114  * Return the number of decoded entries in DEWEY.
 115  */
 116
 117 int
 118 getdewey(dewey, cp)
 119 int     dewey[];
 120 char    *cp;
 121 {
 122         int     i, n;
 123
 124         for (n = 0, i = 0; i < MAXDEWEY; i++) {
 125                 if (*cp == '\0')
 126                         break;
 127
 128                 if (*cp == '.') cp++;
 129                 if (!isdigit(*cp))
 130                         return 0;
 131
 132                 dewey[n++] = strtol(cp, &cp, 10);
 133         }
 134
 135         return n;
 136 }
 137
 138 /*
 139  * Compare two dewey arrays.
 140  * Return -1 if `d1' represents a smaller value than `d2'.
 141  * Return  1 if `d1' represents a greater value than `d2'.
 142  * Return  0 if equal.
 143  */
 144 int
 145 cmpndewey(d1, n1, d2, n2)
 146 int     d1[], d2[];
 147 int     n1, n2;
 148 {
 149         register int    i;
 150
 151         for (i = 0; i < n1 && i < n2; i++) {
 152                 if (d1[i] < d2[i])
 153                         return -1;
 154                 if (d1[i] > d2[i])
 155                         return 1;
 156         }
 157
 158         if (n1 == n2)
 159                 return 0;
 160
 161         if (i == n1)
 162                 return -1;
 163
 164         if (i == n2)
 165                 return 1;
 166
 167         errx(1, "cmpndewey: cant happen");
 168         return 0;
 169 }
 170
 171 /*
 172  * Search directories for a shared library matching the given
 173  * major and minor version numbers.  See search_lib_dir() below for
 174  * the detailed matching rules.
 175  *
 176  * As soon as a directory with an acceptable match is found, the search
 177  * terminates.  Subsequent directories are not searched for a better
 178  * match.  This is in conformance with the SunOS searching rules.  Also,
 179  * it avoids a lot of directory searches that are virtually guaranteed to
 180  * be fruitless.
 181  *
 182  * The return value is a full pathname to the matching library.  The
 183  * string is dynamically allocated.  If no matching library is found, the
 184  * function returns NULL.
 185  */
 186
 187 char *
 188 findshlib(name, majorp, minorp, do_dot_a)
 189 char    *name;
 190 int     *majorp, *minorp;
 191 int     do_dot_a;
 192 {
 193         int             i;
 194
 195         for (i = 0; i < n_search_dirs; i++) {
 196                 char    *path;
 197
 198                 path = search_lib_dir(search_dirs[i], name, majorp, minorp,
 199                         do_dot_a);
 200                 if(path != NULL)
 201                         return path;
 202         }
 203
 204         return NULL;
 205 }
 206
 207 /*
 208  * Search library directories for a file with the given name.  The
 209  * return value is a full pathname to the matching file.  The string
 210  * is dynamically allocated.  If no matching file is found, the function
 211  * returns NULL.
 212  */
 213
 214 char *
 215 find_lib_file(name)
 216         const char      *name;
 217 {
 218         int             i;
 219
 220         for (i = 0; i < n_search_dirs; i++) {
 221                 char            *path = concat(search_dirs[i], "/", name);
 222                 struct stat     sb;
 223
 224                 if (lstat(path, &sb) != -1)     /* We found it */
 225                         return path;
 226
 227                 free(path);
 228         }
 229
 230         return NULL;
 231 }
 232
 233 /*
 234  * Search a given directory for a library (preferably shared) satisfying
 235  * the given criteria.
 236  *
 237  * The matching rules are as follows:
 238  *
 239  *      if(*majorp == -1)
 240  *              find the library with the highest major version;
 241  *      else
 242  *              insist on a major version identical to *majorp;
 243  *
 244  *      Always find the library with the highest minor version;
 245  *      if(*minorp != -1)
 246  *              insist on a minor version >= *minorp;
 247  *
 248  * It is invalid to specify a specific minor number while wildcarding
 249  * the major number.
 250  *
 251  * The actual major and minor numbers found are returned via the pointer
 252  * arguments.
 253  *
 254  * A suitable shared library is always preferred over a static (.a) library.
 255  * If do_dot_a is false, then a static library will not be accepted in
 256  * any case.
 257  *
 258  * The return value is a full pathname to the matching library.  The
 259  * string is dynamically allocated.  If no matching library is found, the
 260  * function returns NULL.
 261  */
 262
 263 char *
 264 search_lib_dir(dir, name, majorp, minorp, do_dot_a)
 265         char            *dir;
 266         char            *name;
 267         int             *majorp;
 268         int             *minorp;
 269         int             do_dot_a;
 270 {
 271         size_t          namelen;
 272         DIR             *dd;
 273         struct dirent   *dp;
 274         int             best_dewey[MAXDEWEY];
 275         int             best_ndewey;
 276         char            dot_a_name[MAXNAMLEN+1];
 277         char            dot_so_name[MAXNAMLEN+1];
 278
 279         if((dd = opendir(dir)) == NULL)
 280                 return NULL;
 281
 282         namelen = strlen(name);
 283         best_ndewey = 0;
 284         dot_a_name[0] = '\0';
 285         dot_so_name[0] = '\0';
 286
 287         while((dp = readdir(dd)) != NULL) {
 288                 char *extension;
 289
 290                 if(strlen(dp->d_name) < 3 + namelen + 2 ||      /* lib+xxx+.a */
 291                    strncmp(dp->d_name, "lib", 3) != 0 ||
 292                    strncmp(dp->d_name + 3, name, namelen) != 0 ||
 293                    dp->d_name[3+namelen] != '.')
 294                         continue;
 295
 296                 extension = dp->d_name + 3 + namelen + 1;       /* a or so.* */
 297
 298                 if(strncmp(extension, "so.", 3) == 0) {
 299                         int cur_dewey[MAXDEWEY];
 300                         int cur_ndewey;
 301
 302                         cur_ndewey = getdewey(cur_dewey, extension+3);
 303                         if(cur_ndewey < 2)      /* Too few version numbers */
 304                                 continue;
 305
 306                         if(*majorp != -1) {     /* Need exact match on major */
 307                                 if(cur_dewey[0] != *majorp)
 308                                         continue;
 309                                 if(*minorp != -1) {  /* Need minor >= minimum */
 310                                         if(cur_dewey[1] < *minorp)
 311                                                 continue;
 312                                 }
 313                         }
 314
 315                         if(cmpndewey(cur_dewey, cur_ndewey, best_dewey,
 316                            best_ndewey) <= 0)   /* No better than prior match */
 317                                 continue;
 318
 319                         /* We found a better match */
 320                         strcpy(dot_so_name, dp->d_name);
 321                         bcopy(cur_dewey, best_dewey,
 322                                 cur_ndewey * sizeof best_dewey[0]);
 323                         best_ndewey = cur_ndewey;
 324                 } else if(do_dot_a && strcmp(extension, "a") == 0)
 325                         strcpy(dot_a_name, dp->d_name);
 326         }
 327         closedir(dd);
 328
 329         if(dot_so_name[0] != '\0') {
 330                 *majorp = best_dewey[0];
 331                 *minorp = best_dewey[1];
 332                 return concat(dir, "/", dot_so_name);
 333         }
 334
 335         if(dot_a_name[0] != '\0')
 336                 return concat(dir, "/", dot_a_name);
 337
 338         return NULL;
 339 }