source4/web_server/wsgi.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Samba utility functions
   4    Copyright © Jelmer Vernooij <jelmer@samba.org> 2008
   5
   6    Implementation of the WSGI interface described in PEP0333
   7    (http://www.python.org/dev/peps/pep-0333)
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 3 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  21 */
  22
  23 #include <Python.h>
  24 #include "includes.h"
  25 #include "web_server/web_server.h"
  26 #include "../lib/util/dlinklist.h"
  27 #include "lib/tls/tls.h"
  28 #include "lib/tsocket/tsocket.h"
  29 #include "python/modules.h"
  30
  31 /* There's no Py_ssize_t in 2.4, apparently */
  32 #if PY_MAJOR_VERSION == 2 && PY_MINOR_VERSION < 5
  33 typedef int Py_ssize_t;
  34 typedef inquiry lenfunc;
  35 typedef intargfunc ssizeargfunc;
  36 #endif
  37
  38 typedef struct {
  39         PyObject_HEAD
  40         struct websrv_context *web;
  41 } web_request_Object;
  42
  43 static PyObject *start_response(PyObject *self, PyObject *args, PyObject *kwargs)
  44 {
  45         PyObject *response_header, *exc_info = NULL;
  46         char *status;
  47         Py_ssize_t i;
  48         const char *kwnames[] = {
  49                 "status", "response_header", "exc_info", NULL
  50         };
  51         web_request_Object *py_web = (web_request_Object *)self;
  52         struct websrv_context *web = py_web->web;
  53         struct http_header *headers = NULL;
  54
  55         if (!PyArg_ParseTupleAndKeywords(args, kwargs, "sO|O:start_response", discard_const_p(char *, kwnames), &status, &response_header, &exc_info)) {
  56                 return NULL;
  57         }
  58
  59         /* FIXME: exc_info */
  60
  61         if (!PyList_Check(response_header)) {
  62                 PyErr_SetString(PyExc_TypeError, "response_header should be list");
  63                 return NULL;
  64         }
  65
  66         for (i = 0; i < PyList_Size(response_header); i++) {
  67                 struct http_header *hdr = talloc_zero(web, struct http_header);
  68                 PyObject *item = PyList_GetItem(response_header, i);
  69                 PyObject *py_name, *py_value;
  70
  71                 if (!PyTuple_Check(item)) {
  72                         PyErr_SetString(PyExc_TypeError, "Expected tuple");
  73                         return NULL;
  74                 }
  75
  76                 if (PyTuple_Size(item) != 2) {
  77                         PyErr_SetString(PyExc_TypeError, "header tuple has invalid size, expected 2");
  78                         return NULL;
  79                 }
  80
  81                 py_name = PyTuple_GetItem(item, 0);
  82
  83                 if (!PyString_Check(py_name)) {
  84                         PyErr_SetString(PyExc_TypeError, "header name should be string");
  85                         return NULL;
  86                 }
  87
  88                 py_value = PyTuple_GetItem(item, 1);
  89                 if (!PyString_Check(py_value)) {
  90                         PyErr_SetString(PyExc_TypeError, "header value should be string");
  91                         return NULL;
  92                 }
  93
  94                 hdr->name = talloc_strdup(hdr, PyString_AsString(py_name));
  95                 hdr->value = talloc_strdup(hdr, PyString_AsString(py_value));
  96                 DLIST_ADD(headers, hdr);
  97         }
  98
  99         websrv_output_headers(web, status, headers);
 100
 101         Py_RETURN_NONE;
 102 }
 103
 104 static PyMethodDef web_request_methods[] = {
 105         { "start_response", (PyCFunction)start_response, METH_VARARGS|METH_KEYWORDS, NULL },
 106         { NULL }
 107 };
 108
 109
 110 PyTypeObject web_request_Type = {
 111         PyObject_HEAD_INIT(NULL) 0,
 112         .tp_name = "wsgi.Request",
 113         .tp_methods = web_request_methods,
 114         .tp_basicsize = sizeof(web_request_Object),
 115         .tp_flags = Py_TPFLAGS_DEFAULT,
 116 };
 117
 118 typedef struct {
 119         PyObject_HEAD
 120 } error_Stream_Object;
 121
 122 static PyObject *py_error_flush(PyObject *self, PyObject *args, PyObject *kwargs)
 123 {
 124         /* Nothing to do here */
 125         Py_RETURN_NONE;
 126 }
 127
 128 static PyObject *py_error_write(PyObject *self, PyObject *args, PyObject *kwargs)
 129 {
 130         const char *kwnames[] = { "str", NULL };
 131         char *str = NULL;
 132
 133         if (!PyArg_ParseTupleAndKeywords(args, kwargs, "s:write", discard_const_p(char *, kwnames), &str)) {
 134                 return NULL;
 135         }
 136
 137         DEBUG(0, ("%s", str));
 138
 139         Py_RETURN_NONE;
 140 }
 141
 142 static PyObject *py_error_writelines(PyObject *self, PyObject *args, PyObject *kwargs)
 143 {
 144         const char *kwnames[] = { "seq", NULL };
 145         PyObject *seq = NULL, *item;
 146
 147         if (!PyArg_ParseTupleAndKeywords(args, kwargs, "O:writelines", discard_const_p(char *, kwnames), &seq)) {
 148                 return NULL;
 149         }
 150
 151         while ((item = PyIter_Next(seq))) {
 152                 char *str = PyString_AsString(item);
 153
 154                 DEBUG(0, ("%s", str));
 155         }
 156
 157         Py_RETURN_NONE;
 158 }
 159
 160 static PyMethodDef error_Stream_methods[] = {
 161         { "flush", (PyCFunction)py_error_flush, METH_VARARGS|METH_KEYWORDS, NULL },
 162         { "write", (PyCFunction)py_error_write, METH_VARARGS|METH_KEYWORDS, NULL },
 163         { "writelines", (PyCFunction)py_error_writelines, METH_VARARGS|METH_KEYWORDS, NULL },
 164         { NULL, NULL, 0, NULL }
 165 };
 166
 167 PyTypeObject error_Stream_Type = {
 168         PyObject_HEAD_INIT(NULL) 0,
 169         .tp_name = "wsgi.ErrorStream",
 170         .tp_basicsize = sizeof(error_Stream_Object),
 171         .tp_methods = error_Stream_methods,
 172         .tp_flags = Py_TPFLAGS_DEFAULT,
 173 };
 174
 175 typedef struct {
 176         PyObject_HEAD
 177         struct websrv_context *web;
 178         size_t offset;
 179 } input_Stream_Object;
 180
 181 static PyObject *py_input_read(PyObject *_self, PyObject *args, PyObject *kwargs)
 182 {
 183         const char *kwnames[] = { "size", NULL };
 184         PyObject *ret;
 185         input_Stream_Object *self = (input_Stream_Object *)_self;
 186         int size = -1;
 187
 188         if (!PyArg_ParseTupleAndKeywords(args, kwargs, "|i", discard_const_p(char *, kwnames), &size))
 189                 return NULL;
 190
 191         /* Don't read beyond buffer boundaries */
 192         if (size == -1)
 193                 size = self->web->input.partial.length-self->offset;
 194         else
 195                 size = MIN(size, self->web->input.partial.length-self->offset);
 196
 197         ret = PyString_FromStringAndSize((char *)self->web->input.partial.data+self->offset, size);
 198         self->offset += size;
 199
 200         return ret;
 201 }
 202
 203 static PyObject *py_input_readline(PyObject *_self)
 204 {
 205         /* FIXME */
 206         PyErr_SetString(PyExc_NotImplementedError,
 207                         "readline() not yet implemented");
 208         return NULL;
 209 }
 210
 211 static PyObject *py_input_readlines(PyObject *_self, PyObject *args, PyObject *kwargs)
 212 {
 213         const char *kwnames[] = { "hint", NULL };
 214         int hint;
 215
 216         if (!PyArg_ParseTupleAndKeywords(args, kwargs, "|i", discard_const_p(char *, kwnames), &hint))
 217                 return NULL;
 218
 219         /* FIXME */
 220         PyErr_SetString(PyExc_NotImplementedError,
 221                         "readlines() not yet implemented");
 222         return NULL;
 223 }
 224
 225 static PyObject *py_input___iter__(PyObject *_self)
 226 {
 227         /* FIXME */
 228         PyErr_SetString(PyExc_NotImplementedError,
 229                         "__iter__() not yet implemented");
 230         return NULL;
 231 }
 232
 233 static PyMethodDef input_Stream_methods[] = {
 234         { "read", (PyCFunction)py_input_read, METH_VARARGS|METH_KEYWORDS, NULL },
 235         { "readline", (PyCFunction)py_input_readline, METH_NOARGS, NULL },
 236         { "readlines", (PyCFunction)py_input_readlines, METH_VARARGS|METH_KEYWORDS, NULL },
 237         { "__iter__", (PyCFunction)py_input___iter__, METH_NOARGS, NULL },
 238         { NULL, NULL, 0, NULL }
 239 };
 240
 241 PyTypeObject input_Stream_Type = {
 242         PyObject_HEAD_INIT(NULL) 0,
 243         .tp_name = "wsgi.InputStream",
 244         .tp_basicsize = sizeof(input_Stream_Object),
 245         .tp_methods = input_Stream_methods,
 246         .tp_flags = Py_TPFLAGS_DEFAULT,
 247 };
 248
 249 static PyObject *Py_InputHttpStream(struct websrv_context *web)
 250 {
 251         input_Stream_Object *ret = PyObject_New(input_Stream_Object, &input_Stream_Type);
 252         ret->web = web;
 253         ret->offset = 0;
 254         return (PyObject *)ret;
 255 }
 256
 257 static PyObject *Py_ErrorHttpStream(void)
 258 {
 259         error_Stream_Object *ret = PyObject_New(error_Stream_Object, &error_Stream_Type);
 260         return (PyObject *)ret;
 261 }
 262
 263 static void DEBUG_Print_PyError(int level, const char *message)
 264 {
 265         PyObject *old_stderr, *new_stderr;
 266         PyObject *sys_module;
 267         PyObject *ptype, *pvalue, *ptb;
 268
 269         PyErr_Fetch(&ptype, &pvalue, &ptb);
 270
 271         DEBUG(0, ("WSGI: Server exception occurred: %s\n", message));
 272
 273         sys_module = PyImport_ImportModule("sys");
 274         if (sys_module == NULL) {
 275                 DEBUG(0, ("Unable to obtain sys module while printing error"));
 276                 return;
 277         }
 278
 279         old_stderr = PyObject_GetAttrString(sys_module, "stderr");
 280         if (old_stderr == NULL) {
 281                 DEBUG(0, ("Unable to obtain old stderr"));
 282                 Py_DECREF(sys_module);
 283                 return;
 284         }
 285
 286         new_stderr = Py_ErrorHttpStream();
 287         if (new_stderr == NULL) {
 288                 DEBUG(0, ("Unable to create error stream"));
 289                 Py_DECREF(sys_module);
 290                 Py_DECREF(old_stderr);
 291                 return;
 292         }
 293
 294         PyObject_SetAttrString(sys_module, "stderr", new_stderr);
 295         Py_DECREF(new_stderr);
 296
 297         PyErr_Restore(ptype, pvalue, ptb);
 298         PyErr_Print();
 299
 300         PyObject_SetAttrString(sys_module, "stderr", old_stderr);
 301         Py_DECREF(old_stderr);
 302
 303         Py_DECREF(sys_module);
 304 }
 305
 306 static PyObject *create_environ(bool tls, int content_length, struct http_header *headers, const char *request_method, const char *servername, int serverport, PyObject *inputstream, const char *request_string)
 307 {
 308         PyObject *env;
 309         PyObject *py_scheme;
 310         PyObject *py_val;
 311         struct http_header *hdr;
 312         char *questionmark;
 313
 314         env = PyDict_New();
 315         if (env == NULL) {
 316                 return NULL;
 317         }
 318
 319         PyDict_SetItemString(env, "wsgi.input", inputstream);
 320
 321         py_val = Py_ErrorHttpStream();
 322         if (py_val == NULL) goto error;
 323         PyDict_SetItemString(env, "wsgi.errors", py_val);
 324         Py_DECREF(py_val);
 325
 326         py_val = Py_BuildValue("(i,i)", 1, 0);
 327         if (py_val == NULL) goto error;
 328         PyDict_SetItemString(env, "wsgi.version", py_val);
 329         Py_DECREF(py_val);
 330         PyDict_SetItemString(env, "wsgi.multithread", Py_False);
 331         PyDict_SetItemString(env, "wsgi.multiprocess", Py_False);
 332         PyDict_SetItemString(env, "wsgi.run_once", Py_False);
 333         py_val = PyString_FromString("HTTP/1.0");
 334         if (py_val == NULL) goto error;
 335         PyDict_SetItemString(env, "SERVER_PROTOCOL", py_val);
 336         Py_DECREF(py_val);
 337         if (content_length > 0) {
 338                 py_val = PyLong_FromLong(content_length);
 339                 if (py_val == NULL) goto error;
 340                 PyDict_SetItemString(env, "CONTENT_LENGTH", py_val);
 341                 Py_DECREF(py_val);
 342         }
 343         py_val = PyString_FromString(request_method);
 344         if (py_val == NULL) goto error;
 345         PyDict_SetItemString(env, "REQUEST_METHOD", py_val);
 346         Py_DECREF(py_val);
 347
 348         /* There is always a single wsgi app to which all requests are redirected,
 349          * so SCRIPT_NAME will be / */
 350         py_val = PyString_FromString("/");
 351         if (py_val == NULL) goto error;
 352         PyDict_SetItemString(env, "SCRIPT_NAME", py_val);
 353         Py_DECREF(py_val);
 354         questionmark = strchr(request_string, '?');
 355         if (questionmark == NULL) {
 356                 py_val = PyString_FromString(request_string);
 357                 if (py_val == NULL) goto error;
 358                 PyDict_SetItemString(env, "PATH_INFO", py_val);
 359                 Py_DECREF(py_val);
 360         } else {
 361                 py_val = PyString_FromString(questionmark+1);
 362                 if (py_val == NULL) goto error;
 363                 PyDict_SetItemString(env, "QUERY_STRING", py_val);
 364                 Py_DECREF(py_val);
 365                 py_val = PyString_FromStringAndSize(request_string, questionmark-request_string);
 366                 if (py_val == NULL) goto error;
 367                 PyDict_SetItemString(env, "PATH_INFO", py_val);
 368                 Py_DECREF(py_val);
 369         }
 370
 371         py_val = PyString_FromString(servername);
 372         if (py_val == NULL) goto error;
 373         PyDict_SetItemString(env, "SERVER_NAME", py_val);
 374         Py_DECREF(py_val);
 375         py_val = PyString_FromFormat("%d", serverport);
 376         if (py_val == NULL) goto error;
 377         PyDict_SetItemString(env, "SERVER_PORT", py_val);
 378         Py_DECREF(py_val);
 379
 380         for (hdr = headers; hdr; hdr = hdr->next) {
 381                 char *name;
 382                 if (!strcasecmp(hdr->name, "Content-Type")) {
 383                         py_val = PyString_FromString(hdr->value);
 384                         PyDict_SetItemString(env, "CONTENT_TYPE", py_val);
 385                         Py_DECREF(py_val);
 386                 } else {
 387                         if (asprintf(&name, "HTTP_%s", hdr->name) < 0) {
 388                                 PyErr_NoMemory();
 389                                 goto error;
 390                         }
 391                         py_val = PyString_FromString(hdr->value);
 392                         PyDict_SetItemString(env, name, py_val);
 393                         Py_DECREF(py_val);
 394                         free(name);
 395                 }
 396         }
 397
 398         if (tls) {
 399                 py_scheme = PyString_FromString("https");
 400         } else {
 401                 py_scheme = PyString_FromString("http");
 402         }
 403         if (py_scheme == NULL) goto error;
 404         PyDict_SetItemString(env, "wsgi.url_scheme", py_scheme);
 405         Py_DECREF(py_scheme);
 406
 407         return env;
 408 error:
 409         Py_DECREF(env);
 410         return NULL;
 411 }
 412
 413 static void wsgi_serve_500(struct websrv_context *web)
 414 {
 415         struct http_header *headers = NULL;
 416         const char *contents[] = {
 417                 "An internal server error occurred while handling this request. ",
 418                 "Please refer to the server logs for more details. ",
 419                 NULL
 420         };
 421         int i;
 422
 423         websrv_output_headers(web, "500 Internal Server Error", headers);
 424         for (i = 0; contents[i]; i++) {
 425                 websrv_output(web, contents[i], strlen(contents[i]));
 426         }
 427 }
 428
 429 static void wsgi_process_http_input(struct web_server_data *wdata,
 430                                     struct websrv_context *web)
 431 {
 432         PyObject *py_environ, *result, *item, *iter;
 433         PyObject *request_handler = (PyObject *)wdata->private_data;
 434         struct tsocket_address *my_address = web->conn->local_address;
 435         const char *addr = "0.0.0.0";
 436         uint16_t port = 0;
 437         web_request_Object *py_web;
 438         PyObject *py_input_stream;
 439
 440         py_web = PyObject_New(web_request_Object, &web_request_Type);
 441         if (py_web == NULL) {
 442                 DEBUG_Print_PyError(0, "Unable to allocate web request");
 443                 return;
 444         }
 445         py_web->web = web;
 446
 447         if (tsocket_address_is_inet(my_address, "ip")) {
 448                 addr = tsocket_address_inet_addr_string(my_address, wdata);
 449                 port = tsocket_address_inet_port(my_address);
 450         }
 451
 452         py_input_stream = Py_InputHttpStream(web);
 453         if (py_input_stream == NULL) {
 454                 DEBUG_Print_PyError(0, "unable to create python input stream");
 455                 return;
 456         }
 457
 458         py_environ = create_environ(tls_enabled(web->conn->socket),
 459                                     web->input.content_length,
 460                                     web->input.headers,
 461                                     web->input.post_request?"POST":"GET",
 462                                     addr,
 463                                     port,
 464                                     py_input_stream,
 465                                     web->input.url
 466                                     );
 467
 468         Py_DECREF(py_input_stream);
 469
 470         if (py_environ == NULL) {
 471                 DEBUG_Print_PyError(0, "Unable to create WSGI environment object");
 472                 wsgi_serve_500(web);
 473                 return;
 474         }
 475
 476         result = PyObject_CallMethod(request_handler, discard_const_p(char, "__call__"), discard_const_p(char, "OO"),
 477                                        py_environ, PyObject_GetAttrString((PyObject *)py_web, "start_response"));
 478
 479         if (result == NULL) {
 480                 DEBUG_Print_PyError(0, "error while handling request");
 481                 wsgi_serve_500(web);
 482                 return;
 483         }
 484
 485         iter = PyObject_GetIter(result);
 486         Py_DECREF(result);
 487
 488         if (iter == NULL) {
 489                 DEBUG_Print_PyError(0, "application did not return iterable");
 490                 wsgi_serve_500(web);
 491                 return;
 492         }
 493
 494         /* Now, iter over all the data returned */
 495
 496         while ((item = PyIter_Next(iter))) {
 497                 websrv_output(web, PyString_AsString(item), PyString_Size(item));
 498                 Py_DECREF(item);
 499         }
 500
 501         Py_DECREF(iter);
 502 }
 503
 504 bool wsgi_initialize(struct web_server_data *wdata)
 505 {
 506         PyObject *py_web_server;
 507
 508         Py_Initialize();
 509
 510         py_update_path(); /* Ensure that we have the Samba paths at
 511                            * the start of the sys.path() */
 512
 513         if (PyType_Ready(&web_request_Type) < 0)
 514                 return false;
 515
 516         if (PyType_Ready(&input_Stream_Type) < 0)
 517                 return false;
 518
 519         if (PyType_Ready(&error_Stream_Type) < 0)
 520                 return false;
 521
 522         wdata->http_process_input = wsgi_process_http_input;
 523         py_web_server = PyImport_ImportModule("samba.web_server");
 524         if (py_web_server == NULL) {
 525                 DEBUG_Print_PyError(0, "Unable to find web server");
 526                 return false;
 527         }
 528         wdata->private_data = py_web_server;
 529         return true;
 530 }