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sudo 1.8.5p1

    1: /*
    2:  * Copyright (c) 2010 Todd C. Miller <Todd.Miller@courtesan.com>
    3:  *
    4:  * Permission to use, copy, modify, and distribute this software for any
    5:  * purpose with or without fee is hereby granted, provided that the above
    6:  * copyright notice and this permission notice appear in all copies.
    7:  *
    8:  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
    9:  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
   10:  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
   11:  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
   12:  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
   13:  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
   14:  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
   15:  */
   16: 
   17: #include <config.h>
   18: 
   19: #include <sys/types.h>
   20: 
   21: #include <stdio.h>
   22: #ifdef STDC_HEADERS
   23: # include <stdlib.h>
   24: # include <stddef.h>
   25: #else
   26: # ifdef HAVE_STDLIB_H
   27: #  include <stdlib.h>
   28: # endif
   29: #endif /* STDC_HEADERS */
   30: #ifdef HAVE_STRING_H
   31: # include <string.h>
   32: #endif /* HAVE_STRING_H */
   33: #ifdef HAVE_STRINGS_H
   34: # include <strings.h>
   35: #endif /* HAVE_STRINGS_H */
   36: #include <errno.h>
   37: 
   38: #include "compat/dlfcn.h"
   39: #include "missing.h"
   40: 
   41: #ifdef HAVE_SHL_LOAD
   42: /*
   43:  * Emulate dlopen() using shl_load().
   44:  */
   45: #include <dl.h>
   46: 
   47: #ifndef DYNAMIC_PATH
   48: # define DYNAMIC_PATH	0
   49: #endif
   50: 
   51: void *
   52: sudo_dlopen(const char *path, int mode)
   53: {
   54:     int flags = DYNAMIC_PATH;
   55: 
   56:     if (mode == 0)
   57: 	mode = RTLD_LAZY;	/* default behavior */
   58: 
   59:     /* We don't support RTLD_GLOBAL or RTLD_LOCAL yet. */
   60:     if (ISSET(mode, RTLD_LAZY))
   61: 	flags |= BIND_DEFERRED;
   62:     if (ISSET(mode, RTLD_NOW))
   63: 	flags |= BIND_IMMEDIATE;
   64: 
   65:     return (void *)shl_load(path, flags, 0L);
   66: }
   67: 
   68: int
   69: sudo_dlclose(void *handle)
   70: {
   71:     return shl_unload((shl_t)handle);
   72: }
   73: 
   74: void *
   75: sudo_dlsym(void *vhandle, const char *symbol)
   76: {
   77:     shl_t handle = vhandle;
   78:     void *value = NULL;
   79: 
   80:     /*
   81:      * Note that the behavior of of RTLD_NEXT and RTLD_SELF 
   82:      * differs from most implementations when called from
   83:      * a shared library.
   84:      */
   85:     if (vhandle == RTLD_NEXT) {
   86: 	/* Iterate over all shared libs looking for symbol. */
   87: 	struct shl_descriptor *desc;
   88: 	int idx = 0;
   89: 	while (shl_get(idx++, &desc) == 0) {
   90: 	    if (shl_findsym(&desc->handle, symbol, TYPE_UNDEFINED, &value) == 0)
   91: 		break;
   92: 	}
   93:     } else {
   94: 	if (vhandle == RTLD_DEFAULT)
   95: 	    handle = NULL;
   96: 	else if (vhandle == RTLD_SELF)
   97: 	    handle = PROG_HANDLE;
   98: 	(void)shl_findsym(&handle, symbol, TYPE_UNDEFINED, &value);
   99:     }
  100: 
  101:     return value;
  102: }
  103: 
  104: char *
  105: sudo_dlerror(void)
  106: {
  107:     return strerror(errno);
  108: }
  109: 
  110: #else /* !HAVE_SHL_LOAD */
  111: 
  112: /*
  113:  * Emulate dlopen() using a static list of symbols compiled into sudo.
  114:  */
  115: 
  116: struct sudo_preload_table {
  117:     const char *name;
  118:     void *address;
  119: };
  120: extern struct sudo_preload_table sudo_preload_table[];
  121: 
  122: void *
  123: sudo_dlopen(const char *path, int mode)
  124: {
  125:     return (void *)path;
  126: }
  127: 
  128: int
  129: sudo_dlclose(void *handle)
  130: {
  131:     return 0;
  132: }
  133: 
  134: void *
  135: sudo_dlsym(void *handle, const char *symbol)
  136: {
  137:     struct sudo_preload_table *sym;
  138: 
  139:     if (symbol != RTLD_NEXT && symbol != RTLD_DEFAULT && symbol != RTLD_SELF) {
  140: 	for (sym = sudo_preload_table; sym->name != NULL; sym++) {
  141: 	    if (strcmp(symbol, sym->name) == 0)
  142: 		return sym->address;
  143: 	}
  144:     }
  145:     return NULL;
  146: }
  147: 
  148: char *
  149: sudo_dlerror(void)
  150: {
  151:     return strerror(errno);
  152: }
  153: 
  154: #endif /* HAVE_SHL_LOAD */