1 /*
   2  * Copyright (c) 1998, 2013, 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  * Maintains a list of currently loaded DLLs (Dynamic Link Libraries)
  28  * and their associated handles. Library names are case-insensitive.
  29  */
  30 
  31 #include <windows.h>
  32 #include <stdio.h>
  33 #include <string.h>
  34 #include <errno.h>
  35 #include <io.h>
  36 #include <stdlib.h>
  37 
  38 #include "sys.h"
  39 
  40 #include "path_md.h"
  41 
  42 static void dll_build_name(char* buffer, size_t buflen,
  43                            const char* paths, const char* fname) {
  44     char *path, *paths_copy, *next_token;
  45 
  46     paths_copy = strdup(paths);
  47     if (paths_copy == NULL) {
  48         return;
  49     }
  50 
  51     next_token = NULL;
  52     path = strtok_s(paths_copy, PATH_SEPARATOR, &next_token);
  53 
  54     while (path != NULL) {
  55         _snprintf(buffer, buflen, "%s\\%s.dll", path, fname);
  56         if (_access(buffer, 0) == 0) {
  57             break;
  58         }
  59         *buffer = '\0';
  60         path = strtok_s(NULL, PATH_SEPARATOR, &next_token);
  61     }
  62 
  63     free(paths_copy);
  64 }
  65 
  66 /*
  67  * From system_md.c v1.54
  68  */
  69 int
  70 dbgsysGetLastErrorString(char *buf, int len)
  71 {
  72     long errval;
  73 
  74     if ((errval = GetLastError()) != 0) {
  75         /* DOS error */
  76         int n = FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM|FORMAT_MESSAGE_IGNORE_INSERTS,
  77                               NULL, errval,
  78                               0, buf, len, NULL);
  79         if (n > 3) {
  80             /* Drop final '.', CR, LF */
  81             if (buf[n - 1] == '\n') n--;
  82             if (buf[n - 1] == '\r') n--;
  83             if (buf[n - 1] == '.') n--;
  84             buf[n] = '\0';
  85         }
  86         return n;
  87     }
  88 
  89     if (errno != 0) {
  90         /* C runtime error that has no corresponding DOS error code */
  91         const char *s = strerror(errno);
  92         int n = (int)strlen(s);
  93         if (n >= len) n = len - 1;
  94         strncpy(buf, s, n);
  95         buf[n] = '\0';
  96         return n;
  97     }
  98 
  99     return 0;
 100 }
 101 
 102 /*
 103  * Build a machine dependent library name out of a path and file name.
 104  */
 105 void
 106 dbgsysBuildLibName(char *holder, int holderlen, const char *pname, const char *fname)
 107 {
 108     const int pnamelen = pname ? (int)strlen(pname) : 0;
 109 
 110     *holder = '\0';
 111     /* Quietly truncates on buffer overflow. Should be an error. */
 112     if (pnamelen + (int)strlen(fname) + 10 > holderlen) {
 113         return;
 114     }
 115 
 116     if (pnamelen == 0) {
 117         sprintf(holder, "%s.dll", fname);
 118     } else {
 119       dll_build_name(holder, holderlen, pname, fname);
 120     }
 121 }
 122 
 123 void *
 124 dbgsysLoadLibrary(const char * name, char *err_buf, int err_buflen)
 125 {
 126     void *result = LoadLibrary(name);
 127     if (result == NULL) {
 128         /* Error message is pretty lame, try to make a better guess. */
 129         long errcode = GetLastError();
 130         if (errcode == ERROR_MOD_NOT_FOUND) {
 131             strncpy(err_buf, "Can't find dependent libraries", err_buflen-2);
 132             err_buf[err_buflen-1] = '\0';
 133         } else {
 134             dbgsysGetLastErrorString(err_buf, err_buflen);
 135         }
 136     }
 137     return result;
 138 }
 139 
 140 void dbgsysUnloadLibrary(void *handle)
 141 {
 142     FreeLibrary(handle);
 143 }
 144 
 145 void * dbgsysFindLibraryEntry(void *handle, const char *name)
 146 {
 147     return GetProcAddress(handle, name);
 148 }