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1 
2 /* dl module */
3 
4 #include "Python.h"
5 
6 #include <dlfcn.h>
7 
8 #ifdef __VMS
9 #include <unistd.h>
10 #endif
11 
12 #ifndef RTLD_LAZY
13 #define RTLD_LAZY 1
14 #endif
15 
16 typedef void *PyUnivPtr;
17 typedef struct {
18     PyObject_HEAD
19     PyUnivPtr *dl_handle;
20 } dlobject;
21 
22 static PyTypeObject Dltype;
23 
24 static PyObject *Dlerror;
25 
26 static PyObject *
newdlobject(PyUnivPtr * handle)27 newdlobject(PyUnivPtr *handle)
28 {
29     dlobject *xp;
30     xp = PyObject_New(dlobject, &Dltype);
31     if (xp == NULL)
32         return NULL;
33     xp->dl_handle = handle;
34     return (PyObject *)xp;
35 }
36 
37 static void
dl_dealloc(dlobject * xp)38 dl_dealloc(dlobject *xp)
39 {
40     if (xp->dl_handle != NULL)
41         dlclose(xp->dl_handle);
42     PyObject_Del(xp);
43 }
44 
45 static PyObject *
dl_close(dlobject * xp)46 dl_close(dlobject *xp)
47 {
48     if (xp->dl_handle != NULL) {
49         dlclose(xp->dl_handle);
50         xp->dl_handle = NULL;
51     }
52     Py_INCREF(Py_None);
53     return Py_None;
54 }
55 
56 static PyObject *
dl_sym(dlobject * xp,PyObject * args)57 dl_sym(dlobject *xp, PyObject *args)
58 {
59     char *name;
60     PyUnivPtr *func;
61     if (PyString_Check(args)) {
62         name = PyString_AS_STRING(args);
63     } else {
64         PyErr_Format(PyExc_TypeError, "expected string, found %.200s",
65                      Py_TYPE(args)->tp_name);
66         return NULL;
67     }
68     func = dlsym(xp->dl_handle, name);
69     if (func == NULL) {
70         Py_INCREF(Py_None);
71         return Py_None;
72     }
73     return PyInt_FromLong((long)func);
74 }
75 
76 static PyObject *
dl_call(dlobject * xp,PyObject * args)77 dl_call(dlobject *xp, PyObject *args)
78 {
79     PyObject *name;
80     long (*func)(long, long, long, long, long,
81                  long, long, long, long, long);
82     long alist[10];
83     long res;
84     Py_ssize_t i;
85     Py_ssize_t n = PyTuple_Size(args);
86     if (n < 1) {
87         PyErr_SetString(PyExc_TypeError, "at least a name is needed");
88         return NULL;
89     }
90     name = PyTuple_GetItem(args, 0);
91     if (!PyString_Check(name)) {
92         PyErr_SetString(PyExc_TypeError,
93                         "function name must be a string");
94         return NULL;
95     }
96     func = (long (*)(long, long, long, long, long,
97                      long, long, long, long, long))
98       dlsym(xp->dl_handle, PyString_AsString(name));
99     if (func == NULL) {
100         PyErr_SetString(PyExc_ValueError, dlerror());
101         return NULL;
102     }
103     if (n-1 > 10) {
104         PyErr_SetString(PyExc_TypeError,
105                         "too many arguments (max 10)");
106         return NULL;
107     }
108     for (i = 1; i < n; i++) {
109         PyObject *v = PyTuple_GetItem(args, i);
110         if (_PyAnyInt_Check(v)) {
111             alist[i-1] = PyInt_AsLong(v);
112             if (alist[i-1] == -1 && PyErr_Occurred())
113                 return NULL;
114         }
115         else if (PyString_Check(v))
116             alist[i-1] = (long)PyString_AsString(v);
117         else if (v == Py_None)
118             alist[i-1] = (long) ((char *)NULL);
119         else {
120             PyErr_SetString(PyExc_TypeError,
121                        "arguments must be int, string or None");
122             return NULL;
123         }
124     }
125     for (; i <= 10; i++)
126         alist[i-1] = 0;
127     res = (*func)(alist[0], alist[1], alist[2], alist[3], alist[4],
128                   alist[5], alist[6], alist[7], alist[8], alist[9]);
129     return PyInt_FromLong(res);
130 }
131 
132 static PyMethodDef dlobject_methods[] = {
133     {"call",            (PyCFunction)dl_call, METH_VARARGS},
134     {"sym",             (PyCFunction)dl_sym, METH_O},
135     {"close",           (PyCFunction)dl_close, METH_NOARGS},
136     {NULL,              NULL}                    /* Sentinel */
137 };
138 
139 static PyObject *
dl_getattr(dlobject * xp,char * name)140 dl_getattr(dlobject *xp, char *name)
141 {
142     return Py_FindMethod(dlobject_methods, (PyObject *)xp, name);
143 }
144 
145 
146 static PyTypeObject Dltype = {
147     PyVarObject_HEAD_INIT(NULL, 0)
148     "dl.dl",                    /*tp_name*/
149     sizeof(dlobject),           /*tp_basicsize*/
150     0,                          /*tp_itemsize*/
151     /* methods */
152     (destructor)dl_dealloc, /*tp_dealloc*/
153     0,                          /*tp_print*/
154     (getattrfunc)dl_getattr,/*tp_getattr*/
155     0,                          /*tp_setattr*/
156     0,                          /*tp_compare*/
157     0,                          /*tp_repr*/
158     0,                          /*tp_as_number*/
159     0,                          /*tp_as_sequence*/
160     0,                          /*tp_as_mapping*/
161     0,                          /*tp_hash*/
162 };
163 
164 static PyObject *
dl_open(PyObject * self,PyObject * args)165 dl_open(PyObject *self, PyObject *args)
166 {
167     char *name;
168     int mode;
169     PyUnivPtr *handle;
170     if (sizeof(int) != sizeof(long) ||
171         sizeof(long) != sizeof(char *)) {
172         PyErr_SetString(PyExc_SystemError,
173  "module dl requires sizeof(int) == sizeof(long) == sizeof(char*)");
174                 return NULL;
175     }
176 
177     if (PyArg_ParseTuple(args, "z:open", &name))
178         mode = RTLD_LAZY;
179     else {
180         PyErr_Clear();
181         if (!PyArg_ParseTuple(args, "zi:open", &name, &mode))
182             return NULL;
183 #ifndef RTLD_NOW
184         if (mode != RTLD_LAZY) {
185             PyErr_SetString(PyExc_ValueError, "mode must be 1");
186             return NULL;
187         }
188 #endif
189     }
190     handle = dlopen(name, mode);
191     if (handle == NULL) {
192         char *errmsg = dlerror();
193         if (!errmsg)
194             errmsg = "dlopen() error";
195         PyErr_SetString(Dlerror, errmsg);
196         return NULL;
197     }
198 #ifdef __VMS
199     /*   Under OpenVMS dlopen doesn't do any check, just save the name
200      * for later use, so we have to check if the file is readable,
201      * the name can be a logical or a file from SYS$SHARE.
202      */
203     if (access(name, R_OK)) {
204         char fname[strlen(name) + 20];
205         strcpy(fname, "SYS$SHARE:");
206         strcat(fname, name);
207         strcat(fname, ".EXE");
208         if (access(fname, R_OK)) {
209             dlclose(handle);
210             PyErr_SetString(Dlerror,
211                 "File not found or protection violation");
212             return NULL;
213         }
214     }
215 #endif
216     return newdlobject(handle);
217 }
218 
219 static PyMethodDef dl_methods[] = {
220     {"open",            dl_open, METH_VARARGS},
221     {NULL,              NULL}           /* sentinel */
222 };
223 
224 /* From socketmodule.c
225  * Convenience routine to export an integer value.
226  *
227  * Errors are silently ignored, for better or for worse...
228  */
229 static void
insint(PyObject * d,char * name,int value)230 insint(PyObject *d, char *name, int value)
231 {
232     PyObject *v = PyInt_FromLong((long) value);
233     if (!v || PyDict_SetItemString(d, name, v))
234         PyErr_Clear();
235 
236     Py_XDECREF(v);
237 }
238 
239 PyMODINIT_FUNC
initdl(void)240 initdl(void)
241 {
242     PyObject *m, *d, *x;
243 
244     if (PyErr_WarnPy3k("the dl module has been removed in "
245                         "Python 3.0; use the ctypes module instead", 2) < 0)
246         return;
247 
248     /* Initialize object type */
249     Py_TYPE(&Dltype) = &PyType_Type;
250 
251     /* Create the module and add the functions */
252     m = Py_InitModule("dl", dl_methods);
253     if (m == NULL)
254         return;
255 
256     /* Add some symbolic constants to the module */
257     d = PyModule_GetDict(m);
258     Dlerror = x = PyErr_NewException("dl.error", NULL, NULL);
259     PyDict_SetItemString(d, "error", x);
260     x = PyInt_FromLong((long)RTLD_LAZY);
261     PyDict_SetItemString(d, "RTLD_LAZY", x);
262 #define INSINT(X)    insint(d,#X,X)
263 #ifdef RTLD_NOW
264     INSINT(RTLD_NOW);
265 #endif
266 #ifdef RTLD_NOLOAD
267     INSINT(RTLD_NOLOAD);
268 #endif
269 #ifdef RTLD_GLOBAL
270     INSINT(RTLD_GLOBAL);
271 #endif
272 #ifdef RTLD_LOCAL
273     INSINT(RTLD_LOCAL);
274 #endif
275 #ifdef RTLD_PARENT
276     INSINT(RTLD_PARENT);
277 #endif
278 #ifdef RTLD_GROUP
279     INSINT(RTLD_GROUP);
280 #endif
281 #ifdef RTLD_WORLD
282     INSINT(RTLD_WORLD);
283 #endif
284 #ifdef RTLD_NODELETE
285     INSINT(RTLD_NODELETE);
286 #endif
287 }
288