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 static struct {
52 dev_t dev;
53 ino_t ino;
54 void *handle;
55 } handles[128];
56 static int nhandles = 0;
57
58
59 dl_funcptr
_PyImport_FindSharedFuncptr(const char * prefix,const char * shortname,const char * pathname,FILE * fp)60 _PyImport_FindSharedFuncptr(const char *prefix,
61 const char *shortname,
62 const char *pathname, FILE *fp)
63 {
64 dl_funcptr p;
65 void *handle;
66 char funcname[258];
67 char pathbuf[260];
68 int dlopenflags=0;
69
70 if (strchr(pathname, '/') == NULL) {
71 /* Prefix bare filename with "./" */
72 PyOS_snprintf(pathbuf, sizeof(pathbuf), "./%-.255s", pathname);
73 pathname = pathbuf;
74 }
75
76 PyOS_snprintf(funcname, sizeof(funcname),
77 LEAD_UNDERSCORE "%.20s_%.200s", prefix, shortname);
78
79 if (fp != NULL) {
80 int i;
81 struct _Py_stat_struct status;
82 if (_Py_fstat(fileno(fp), &status) == -1)
83 return NULL;
84 for (i = 0; i < nhandles; i++) {
85 if (status.st_dev == handles[i].dev &&
86 status.st_ino == handles[i].ino) {
87 p = (dl_funcptr) dlsym(handles[i].handle,
88 funcname);
89 return p;
90 }
91 }
92 if (nhandles < 128) {
93 handles[nhandles].dev = status.st_dev;
94 handles[nhandles].ino = status.st_ino;
95 }
96 }
97
98 dlopenflags = _PyInterpreterState_GET()->dlopenflags;
99
100 handle = dlopen(pathname, dlopenflags);
101
102 if (handle == NULL) {
103 PyObject *mod_name;
104 PyObject *path;
105 PyObject *error_ob;
106 const char *error = dlerror();
107 if (error == NULL)
108 error = "unknown dlopen() error";
109 error_ob = PyUnicode_DecodeLocale(error, "surrogateescape");
110 if (error_ob == NULL)
111 return NULL;
112 mod_name = PyUnicode_FromString(shortname);
113 if (mod_name == NULL) {
114 Py_DECREF(error_ob);
115 return NULL;
116 }
117 path = PyUnicode_DecodeFSDefault(pathname);
118 if (path == NULL) {
119 Py_DECREF(error_ob);
120 Py_DECREF(mod_name);
121 return NULL;
122 }
123 PyErr_SetImportError(error_ob, mod_name, path);
124 Py_DECREF(error_ob);
125 Py_DECREF(mod_name);
126 Py_DECREF(path);
127 return NULL;
128 }
129 if (fp != NULL && nhandles < 128)
130 handles[nhandles++].handle = handle;
131 p = (dl_funcptr) dlsym(handle, funcname);
132 return p;
133 }
134