1 /*
   2  * Copyright (c) 1998, 2019, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 /*
  27  * Machine Dependent implementation of the dynamic linking support
  28  * for java.  This routine is Unix specific.
  29  */
  30 
  31 #include <stdio.h>
  32 #include <dlfcn.h>
  33 #include <unistd.h>
  34 #include <stdlib.h>
  35 #include <string.h>
  36 
  37 #include "path_md.h"
  38 
  39 #ifdef __APPLE__
  40 #define LIB_SUFFIX "dylib"
  41 #else
  42 #define LIB_SUFFIX "so"
  43 #endif
  44 
  45 static void dll_build_name(char* buffer, size_t buflen,
  46                            const char* paths, const char* fname) {
  47     char *path, *paths_copy, *next_token;
  48 
  49     paths_copy = strdup(paths);
  50     if (paths_copy == NULL) {
  51         return;
  52     }
  53 
  54     next_token = NULL;
  55     path = strtok_r(paths_copy, PATH_SEPARATOR, &next_token);
  56 
  57     while (path != NULL) {
  58         snprintf(buffer, buflen, "%s/lib%s." LIB_SUFFIX, path, fname);
  59         if (access(buffer, F_OK) == 0) {
  60             break;
  61         }
  62         *buffer = '\0';
  63         path = strtok_r(NULL, PATH_SEPARATOR, &next_token);
  64     }
  65 
  66     free(paths_copy);
  67 }
  68 
  69 /*
  70  * create a string for the JNI native function name by adding the
  71  * appropriate decorations.
  72  */
  73 int
  74 dbgsysBuildFunName(char *name, int nameLen, int args_size, int encodingIndex)
  75 {
  76     // On Unix, there is only one encoding method.
  77     if (encodingIndex == 0)
  78         return 1;
  79     return 0;
  80 }
  81 
  82 /*
  83  * create a string for the dynamic lib open call by adding the
  84  * appropriate pre and extensions to a filename and the path
  85  */
  86 void
  87 dbgsysBuildLibName(char *holder, int holderlen, const char *pname,
  88                    const char *fname)
  89 {
  90     const int pnamelen = pname ? strlen(pname) : 0;
  91 
  92     *holder = '\0';
  93     // Quietly truncate on buffer overflow.  Should be an error.
  94     if (pnamelen + (int)strlen(fname) + 10 > holderlen) {
  95         return;
  96     }
  97 
  98     if (pnamelen == 0) {
  99         (void)snprintf(holder, holderlen, "lib%s." LIB_SUFFIX, fname);
 100     } else {
 101       dll_build_name(holder, holderlen, pname, fname);
 102     }
 103 }
 104 
 105 void *
 106 dbgsysLoadLibrary(const char *name, char *err_buf, int err_buflen)
 107 {
 108     void * result;
 109     result = dlopen(name, RTLD_LAZY);
 110     if (result == NULL) {
 111         (void)strncpy(err_buf, dlerror(), err_buflen-2);
 112         err_buf[err_buflen-1] = '\0';
 113     }
 114     return result;
 115 }
 116 
 117 void dbgsysUnloadLibrary(void *handle)
 118 {
 119     (void)dlclose(handle);
 120 }
 121 
 122 void * dbgsysFindLibraryEntry(void *handle, const char *name)
 123 {
 124     return dlsym(handle, name);
 125 }