1  
       2  /* Support for dynamic loading of extension modules */
       3  
       4  #include "Python.h"
       5  #include "pycore_interp.h"    // _PyInterpreterState.dlopenflags
       6  #include "pycore_pystate.h"   // _PyInterpreterState_GET()
       7  #include "importdl.h"
       8  
       9  #include <sys/types.h>
      10  #include <sys/stat.h>
      11  
      12  #if defined(__NetBSD__)
      13  #include <sys/param.h>
      14  #if (NetBSD < 199712)
      15  #include <nlist.h>
      16  #include <link.h>
      17  #define dlerror() "error in dynamic linking"
      18  #endif
      19  #endif /* NetBSD */
      20  
      21  #ifdef HAVE_DLFCN_H
      22  #include <dlfcn.h>
      23  #endif
      24  
      25  #if (defined(__OpenBSD__) || defined(__NetBSD__)) && !defined(__ELF__)
      26  #define LEAD_UNDERSCORE "_"
      27  #else
      28  #define LEAD_UNDERSCORE ""
      29  #endif
      30  
      31  /* The .so extension module ABI tag, supplied by the Makefile via
      32     Makefile.pre.in and configure.  This is used to discriminate between
      33     incompatible .so files so that extensions for different Python builds can
      34     live in the same directory.  E.g. foomodule.cpython-32.so
      35  */
      36  
      37  const char *_PyImport_DynLoadFiletab[] = {
      38  #ifdef __CYGWIN__
      39      ".dll",
      40  #else  /* !__CYGWIN__ */
      41      "." SOABI ".so",
      42  #ifdef ALT_SOABI
      43      "." ALT_SOABI ".so",
      44  #endif
      45      ".abi" PYTHON_ABI_STRING ".so",
      46      ".so",
      47  #endif  /* __CYGWIN__ */
      48      NULL,
      49  };
      50  
      51  
      52  dl_funcptr
      53  _PyImport_FindSharedFuncptr(const char *prefix,
      54                              const char *shortname,
      55                              const char *pathname, FILE *fp)
      56  {
      57      dl_funcptr p;
      58      void *handle;
      59      char funcname[258];
      60      char pathbuf[260];
      61      int dlopenflags=0;
      62  
      63      if (strchr(pathname, '/') == NULL) {
      64          /* Prefix bare filename with "./" */
      65          PyOS_snprintf(pathbuf, sizeof(pathbuf), "./%-.255s", pathname);
      66          pathname = pathbuf;
      67      }
      68  
      69      PyOS_snprintf(funcname, sizeof(funcname),
      70                    LEAD_UNDERSCORE "%.20s_%.200s", prefix, shortname);
      71  
      72      if (fp != NULL) {
      73          struct _Py_stat_struct status;
      74          if (_Py_fstat(fileno(fp), &status) == -1)
      75              return NULL;
      76      }
      77  
      78      dlopenflags = _PyImport_GetDLOpenFlags(_PyInterpreterState_GET());
      79  
      80      handle = dlopen(pathname, dlopenflags);
      81  
      82      if (handle == NULL) {
      83          PyObject *mod_name;
      84          PyObject *path;
      85          PyObject *error_ob;
      86          const char *error = dlerror();
      87          if (error == NULL)
      88              error = "unknown dlopen() error";
      89          error_ob = PyUnicode_DecodeLocale(error, "surrogateescape");
      90          if (error_ob == NULL)
      91              return NULL;
      92          mod_name = PyUnicode_FromString(shortname);
      93          if (mod_name == NULL) {
      94              Py_DECREF(error_ob);
      95              return NULL;
      96          }
      97          path = PyUnicode_DecodeFSDefault(pathname);
      98          if (path == NULL) {
      99              Py_DECREF(error_ob);
     100              Py_DECREF(mod_name);
     101              return NULL;
     102          }
     103          PyErr_SetImportError(error_ob, mod_name, path);
     104          Py_DECREF(error_ob);
     105          Py_DECREF(mod_name);
     106          Py_DECREF(path);
     107          return NULL;
     108      }
     109      p = (dl_funcptr) dlsym(handle, funcname);
     110      return p;
     111  }