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