Python/dynload_shlib.c

   1
   2 /* Support for dynamic loading of extension modules */
   3
   4 #include "Python.h"
   5 #include "importdl.h"
   6
   7 #include <sys/types.h>
   8 #include <sys/stat.h>
   9
  10 #if defined(__NetBSD__)
  11 #include <sys/param.h>
  12 #if (NetBSD < 199712)
  13 #include <nlist.h>
  14 #include <link.h>
  15 #define dlerror() "error in dynamic linking"
  16 #endif
  17 #endif /* NetBSD */
  18
  19 #ifdef HAVE_DLFCN_H
  20 #include <dlfcn.h>
  21 #endif
  22
  23 #if (defined(__OpenBSD__) || defined(__NetBSD__)) && !defined(__ELF__)
  24 #define LEAD_UNDERSCORE "_"
  25 #else
  26 #define LEAD_UNDERSCORE ""
  27 #endif
  28
  29
  30 const struct filedescr _PyImport_DynLoadFiletab[] = {
  31 #ifdef __CYGWIN__
  32         {".dll", "rb", C_EXTENSION},
  33         {"module.dll", "rb", C_EXTENSION},
  34 #else
  35         {".so", "rb", C_EXTENSION},
  36         {"module.so", "rb", C_EXTENSION},
  37 #endif
  38         {0, 0}
  39 };
  40
  41 static struct {
  42         dev_t dev;
  43         ino_t ino;
  44         void *handle;
  45 } handles[128];
  46 static int nhandles = 0;
  47
  48
  49 dl_funcptr _PyImport_GetDynLoadFunc(const char *fqname, const char *shortname,
  50                                     const char *pathname, FILE *fp)
  51 {
  52         dl_funcptr p;
  53         void *handle;
  54         char funcname[258];
  55         char pathbuf[260];
  56         int dlopenflags=0;
  57
  58         if (strchr(pathname, '/') == NULL) {
  59                 /* Prefix bare filename with "./" */
  60                 PyOS_snprintf(pathbuf, sizeof(pathbuf), "./%-.255s", pathname);
  61                 pathname = pathbuf;
  62         }
  63
  64         PyOS_snprintf(funcname, sizeof(funcname),
  65                       LEAD_UNDERSCORE "init%.200s", shortname);
  66
  67         if (fp != NULL) {
  68                 int i;
  69                 struct stat statb;
  70                 fstat(fileno(fp), &statb);
  71                 for (i = 0; i < nhandles; i++) {
  72                         if (statb.st_dev == handles[i].dev &&
  73                             statb.st_ino == handles[i].ino) {
  74                                 p = (dl_funcptr) dlsym(handles[i].handle,
  75                                                        funcname);
  76                                 return p;
  77                         }
  78                 }
  79                 if (nhandles < 128) {
  80                         handles[nhandles].dev = statb.st_dev;
  81                         handles[nhandles].ino = statb.st_ino;
  82                 }
  83         }
  84
  85         dlopenflags = PyThreadState_Get()->interp->dlopenflags;
  86
  87         if (Py_VerboseFlag)
  88                 printf("dlopen(\"%s\", %x);\n", pathname, dlopenflags);
  89
  90         handle = dlopen(pathname, dlopenflags);
  91
  92         if (handle == NULL) {
  93                 PyErr_SetString(PyExc_ImportError, dlerror());
  94                 return NULL;
  95         }
  96         if (fp != NULL && nhandles < 128)
  97                 handles[nhandles++].handle = handle;
  98         p = (dl_funcptr) dlsym(handle, funcname);
  99         return p;
 100 }