dynload.c

   1 /*_. Kernel 0.0: dynload.c */
   2 /*_ , Header */
   3 /*_  . Purpose */
   4 /* Dynamic Loader for Kernel */
   5
   6 /*_  . Credits */
   7 /* See HISTORY.org */
   8 #define _KLINK_SOURCE
   9
  10 /*_  . Includes */
  11 #include "dynload.h"
  12 #include <string.h>
  13 #include <stdio.h>
  14 #include <stdlib.h>
  15
  16 #ifndef MAXPATHLEN
  17 # define MAXPATHLEN 1024
  18 #endif  /*  */
  19 static void make_filename (const char *name, char *filename);
  20 static void make_init_fn (const char *name, char *init_fn);
  21
  22 /*_  . System-specific includes */
  23 /*_   , WIN32 */
  24 #ifdef _WIN32
  25 # include <windows.h>
  26
  27 /*_   , Otherwise assume SUN */
  28 #else
  29 typedef void *HMODULE;
  30 typedef void (*FARPROC) ();
  31
  32 #define SUN_DL
  33 #include <dlfcn.h>
  34 #endif
  35
  36 /*_ , Body */
  37 /*_  . For Win32 */
  38 #ifdef _WIN32
  39
  40 #define PREFIX ""
  41 #define SUFFIX ".dll"
  42 static void
  43 display_w32_error_msg (const char *additional_message)
  44 {
  45   LPVOID msg_buf;
  46   FormatMessage (FORMAT_MESSAGE_FROM_SYSTEM |
  47                    FORMAT_MESSAGE_ALLOCATE_BUFFER, NULL, GetLastError (), 0,
  48                    (LPTSTR) & msg_buf, 0, NULL);
  49   fprintf (stderr, "klink load-extension: %s: %s", additional_message,
  50             msg_buf);
  51   LocalFree (msg_buf);
  52 } static HMODULE
  53
  54 dl_attach (const char *module)
  55 {
  56   HMODULE dll = LoadLibrary (module);
  57   if (!dll)
  58     display_w32_error_msg (module);
  59   return dll;
  60 }
  61
  62 static FARPROC
  63 dl_proc (HMODULE mo, const char *proc)
  64 {
  65   FARPROC procedure = GetProcAddress (mo, proc);
  66   if (!procedure)
  67     display_w32_error_msg (proc);
  68   return procedure;
  69 }
  70
  71 static void
  72 dl_detach (HMODULE mo)
  73 {
  74   (void) FreeLibrary (mo);
  75 }
  76
  77 /*_  . For SUN */
  78 #elif defined(SUN_DL)
  79
  80 #include <dlfcn.h>
  81
  82 #define PREFIX "lib"
  83 #define SUFFIX ".so"
  84   static HMODULE
  85 dl_attach (const char *module)
  86 {
  87   HMODULE so = dlopen (module, RTLD_LAZY);
  88   if (!so)
  89     {
  90       fprintf (stderr, "Error loading klink extension \"%s\": %s\n", module,
  91                 dlerror ());
  92     }
  93   return so;
  94 }
  95
  96 static FARPROC
  97 dl_proc (HMODULE mo, const char *proc)
  98 {
  99   const char *errmsg;
 100   FARPROC fp = (FARPROC) dlsym (mo, proc);
 101   if ((errmsg = dlerror ()) == 0)
 102     {
 103       return fp;
 104     }
 105   fprintf (stderr, "Error initializing kernel module \"%s\": %s\n", proc,
 106             errmsg);
 107   return 0;
 108 }
 109
 110 static void
 111 dl_detach (HMODULE mo)
 112 {
 113   (void) dlclose (mo);
 114 }
 115 #endif  /*  */
 116 pko
 117 klink_load_ext (klink * sc, pko args)
 118 {
 119   pko first_arg;
 120   pko retval;
 121   char filename[MAXPATHLEN], init_fn[MAXPATHLEN + 6];
 122   char *name;
 123   HMODULE dll_handle;
 124   void (*module_init) (klink * sc);
 125   if ((args != K_NIL) && is_string ((first_arg = pair_car (sc,args))))
 126     {
 127       name = string_value (first_arg);
 128       make_filename (name, filename);
 129       make_init_fn (name, init_fn);
 130       dll_handle = dl_attach (filename);
 131       if (dll_handle == 0)
 132         {
 133           retval = K_F;
 134         }
 135
 136       else
 137         {
 138           module_init = (void (*)(klink *)) dl_proc (dll_handle, init_fn);
 139           if (module_init != 0)
 140             {
 141               (*module_init) (sc);
 142               retval = K_T;
 143             }
 144
 145           else
 146             {
 147               retval = K_F;
 148             }
 149         }
 150     }
 151
 152   else
 153     {
 154       retval = K_F;
 155     }
 156   return (retval);
 157 }
 158
 159 static void
 160 make_filename (const char *name, char *filename)
 161 {
 162   strcpy (filename, name);
 163   strcat (filename, SUFFIX);
 164 } static void
 165
 166 make_init_fn (const char *name, char *init_fn)
 167 {
 168   const char *p = strrchr (name, '/');
 169   if (p == 0)
 170     {
 171       p = name;
 172     }
 173   else
 174     {
 175       p++;
 176     }
 177   strcpy (init_fn, "init_");
 178   strcat (init_fn, p);
 179 }
 180
 181
 182 /*_ , Footers */
 183 /*
 184 Local variables:
 185 c-file-style: "gnu"
 186 mode: allout
 187 End:
 188 */