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 /* The .so extension module ABI tag, supplied by the Makefile via
30 Makefile.pre.in and configure. This is used to discriminate between
31 incompatible .so files so that extensions for different Python builds can
32 live in the same directory. E.g. foomodule.cpython-32.so
33 */
34
35 const char *_PyImport_DynLoadFiletab[] = {
36 #ifdef __CYGWIN__
37 ".dll",
38 #else /* !__CYGWIN__ */
39 "." SOABI ".so",
40 ".abi" PYTHON_ABI_STRING ".so",
41 ".so",
42 #endif /* __CYGWIN__ */
43 NULL,
44 };
45
46 static struct {
47 dev_t dev;
48 ino_t ino;
49 void *handle;
50 } handles[128];
51 static int nhandles = 0;
52
53
54 dl_funcptr
_PyImport_FindSharedFuncptr(const char * prefix,const char * shortname,const char * pathname,FILE * fp)55 _PyImport_FindSharedFuncptr(const char *prefix,
56 const char *shortname,
57 const char *pathname, FILE *fp)
58 {
59 dl_funcptr p;
60 void *handle;
61 char funcname[258];
62 char pathbuf[260];
63 int dlopenflags=0;
64
65 if (strchr(pathname, '/') == NULL) {
66 /* Prefix bare filename with "./" */
67 PyOS_snprintf(pathbuf, sizeof(pathbuf), "./%-.255s", pathname);
68 pathname = pathbuf;
69 }
70
71 PyOS_snprintf(funcname, sizeof(funcname),
72 LEAD_UNDERSCORE "%.20s_%.200s", prefix, shortname);
73
74 if (fp != NULL) {
75 int i;
76 struct _Py_stat_struct status;
77 if (_Py_fstat(fileno(fp), &status) == -1)
78 return NULL;
79 for (i = 0; i < nhandles; i++) {
80 if (status.st_dev == handles[i].dev &&
81 status.st_ino == handles[i].ino) {
82 p = (dl_funcptr) dlsym(handles[i].handle,
83 funcname);
84 return p;
85 }
86 }
87 if (nhandles < 128) {
88 handles[nhandles].dev = status.st_dev;
89 handles[nhandles].ino = status.st_ino;
90 }
91 }
92
93 dlopenflags = PyThreadState_GET()->interp->dlopenflags;
94
95 handle = dlopen(pathname, dlopenflags);
96
97 if (handle == NULL) {
98 PyObject *mod_name;
99 PyObject *path;
100 PyObject *error_ob;
101 const char *error = dlerror();
102 if (error == NULL)
103 error = "unknown dlopen() error";
104 error_ob = PyUnicode_FromString(error);
105 if (error_ob == NULL)
106 return NULL;
107 mod_name = PyUnicode_FromString(shortname);
108 if (mod_name == NULL) {
109 Py_DECREF(error_ob);
110 return NULL;
111 }
112 path = PyUnicode_FromString(pathname);
113 if (path == NULL) {
114 Py_DECREF(error_ob);
115 Py_DECREF(mod_name);
116 return NULL;
117 }
118 PyErr_SetImportError(error_ob, mod_name, path);
119 Py_DECREF(error_ob);
120 Py_DECREF(mod_name);
121 Py_DECREF(path);
122 return NULL;
123 }
124 if (fp != NULL && nhandles < 128)
125 handles[nhandles++].handle = handle;
126 p = (dl_funcptr) dlsym(handle, funcname);
127 return p;
128 }
129