OpenSRF/src/gateway/mod_ils_gateway.c

   1 /*
   2 Copyright 2002 Kevin O'Donnell
   3
   4 This program is free software; you can redistribute it and/or modify
   5 it under the terms of the GNU General Public License as published by
   6 the Free Software Foundation; either version 2 of the License, or
   7 (at your option) any later version.
   8
   9 This program is distributed in the hope that it will be useful,
  10 but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 GNU General Public License for more details.
  13
  14 You should have received a copy of the GNU General Public License
  15 along with this program; if not, write to the Free Software
  16 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  17 */
  18
  19 /*
  20  * Include the core server components.
  21   */
  22 #include "httpd.h"
  23 #include "http_config.h"
  24 #include "http_core.h"
  25 #include "http_protocol.h"
  26 #include "apr_compat.h"
  27 #include "apr_strings.h"
  28
  29
  30
  31 /* our stuff */
  32 #include "opensrf/transport_client.h"
  33 #include "opensrf/osrf_message.h"
  34 #include "opensrf/osrf_app_session.h"
  35 #include "opensrf/string_array.h"
  36 #include "md5.h"
  37 #include "objson/object.h"
  38 #include "objson/json_parser.h"
  39
  40 #ifdef RESTGATEWAY
  41 #include "rest_xml.h"
  42 #endif
  43
  44 /*
  45  * This function is registered as a handler for HTTP methods and will
  46   * therefore be invoked for all GET requests (and others).  Regardless
  47    * of the request type, this function simply sends a message to
  48  * STDERR (which httpd redirects to logs/error_log).  A real module
  49   * would do *alot* more at this point.
  50    */
  51 #define MODULE_NAME "ils_gateway_module"
  52
  53 /*
  54 struct session_list_struct {
  55         osrf_app_session* session;
  56         struct session_list_struct* next;
  57         int serve_count;
  58 };
  59 typedef struct session_list_struct session_list;
  60
  61 static session_list* the_list = NULL;
  62
  63 static void del_session( char* service ) {
  64         if(!service || ! the_list)
  65                 return;
  66
  67         debug_handler("In del_sesion for %s", service );
  68         session_list* prev = the_list;
  69         session_list* item = prev->next;
  70
  71         if(!strcmp(prev->session->remote_service, service)) {
  72                 info_handler("Removing gateway session for %s", service );
  73                 the_list = item;
  74                 osrf_app_session_destroy(prev->session);
  75                 free(prev);
  76                 return;
  77         }
  78
  79         while(item) {
  80                 if( !strcmp(item->session->remote_service, service)) {
  81                         info_handler("Removing gateway session for %s", service );
  82                         prev->next = item->next;
  83                         osrf_app_session_destroy(item->session);
  84                         free(item);
  85                         return;
  86                 }
  87                 prev = item;
  88                 item = item->next;
  89         }
  90
  91         warning_handler("Attempt to remove gateway session "
  92                         "that does not exist: %s", service );
  93
  94 }
  95
  96 // if(update) we add 1 to the serve_count
  97 static osrf_app_session* find_session( char* service, int update ) {
  98
  99         session_list* item = the_list;
 100         while(item) {
 101
 102                 if(!strcmp(item->session->remote_service,service)) {
 103                         if(update) {
 104                                 if( item->serve_count++ > 20 ) {
 105                                         debug_handler("Disconnected session on 20 requests => %s", service);
 106                                         osrf_app_session_disconnect(item->session);
 107                                         del_session(service);
 108                                         return NULL;
 109                                         //item->serve_count = 0;
 110                                 }
 111                         }
 112                         debug_handler("Found session for %s in gateway cache", service);
 113                         return item->session;
 114                 }
 115
 116                 item = item->next;
 117         }
 118         return NULL;
 119 }
 120
 121 static void add_session( char* service, osrf_app_session* session ) {
 122
 123         if(!session) return;
 124
 125         if(find_session(service,0))
 126                 return;
 127
 128         debug_handler("Add session for %s to the cache", service );
 129
 130         session_list* new_item = (session_list*) safe_malloc(sizeof(session_list));
 131         new_item->session = session;
 132         //new_item->service = service;
 133         new_item->serve_count = 0;
 134
 135         if(the_list) {
 136                 session_list* second = the_list->next;
 137                 the_list = new_item;
 138                 new_item->next = second;
 139         } else {
 140                 the_list = new_item;
 141         }
 142 }
 143 */
 144
 145 static void mod_ils_gateway_child_init(apr_pool_t *p, server_rec *s) {
 146         if( ! osrf_system_bootstrap_client( "/openils/conf/gateway.xml") ) {
 147                 fatal_handler("Unable to load gateway config file...");
 148         }
 149
 150         /* we don't want to waste time parsing json that we're not going to look at*/
 151         osrf_message_set_json_parse_result(0);
 152         osrf_message_set_json_parse_params(0);
 153         fprintf(stderr, "Bootstrapping %d\n", getpid() );
 154         fflush(stderr);
 155 }
 156
 157 static int mod_ils_gateway_method_handler (request_rec *r) {
 158
 159
 160         /* make sure we're needed first thing*/
 161         if (strcmp(r->handler, MODULE_NAME ))
 162                 return DECLINED;
 163
 164
 165         apr_pool_t *p = r->pool;        /* memory pool */
 166         char* arg = r->args;                    /* url query string */
 167
 168         char* service                                   = NULL; /* service to connect to */
 169         char* method                                    = NULL; /* method to perform */
 170
 171         //json* exception                               = NULL; /* returned in error conditions */
 172         object* exception                               = NULL; /* returned in error conditions */
 173         string_array* sarray                    = init_string_array(12); /* method parameters */
 174
 175         growing_buffer* buffer          = NULL; /* POST data */
 176         growing_buffer* tmp_buf         = NULL; /* temp buffer */
 177
 178         char* key                                               = NULL; /* query item name */
 179         char* val                                               = NULL; /* query item value */
 180
 181
 182
 183         /* verify we are connected */
 184         if(!osrf_system_get_transport_client()) {
 185                 fatal_handler("Bootstrap Failed, no transport client");
 186                 return HTTP_INTERNAL_SERVER_ERROR;
 187         }
 188
 189         /* set content type to text/plain for passing around JSON objects */
 190         ap_set_content_type(r, "text/plain");
 191
 192
 193
 194         /* gather the post args and append them to the url query string */
 195         if( !strcmp(r->method,"POST") ) {
 196
 197                 ap_setup_client_block(r,REQUEST_CHUNKED_DECHUNK);
 198
 199                 if(! ap_should_client_block(r)) {
 200                         warning_handler("No Post Body");
 201                 }
 202
 203                 char body[1025];
 204                 memset(body,0,1025);
 205                 buffer = buffer_init(1025);
 206
 207                 while(ap_get_client_block(r, body, 1024)) {
 208                         debug_handler("Apache read POST block data: %s\n", body);
 209                         buffer_add( buffer, body );
 210                         memset(body,0,1025);
 211                 }
 212
 213                 if(arg && arg[0]) {
 214                         tmp_buf = buffer_init(1024);
 215                         buffer_add(tmp_buf,arg);
 216                         buffer_add(tmp_buf,buffer->buf);
 217                         arg = (char*) apr_pstrdup(p, tmp_buf->buf);
 218                         buffer_free(tmp_buf);
 219                 } else {
 220                         arg = (char*) apr_pstrdup(p, buffer->buf);
 221                 }
 222                 buffer_free(buffer);
 223
 224         }
 225
 226         debug_handler("params args are %s", arg);
 227
 228
 229         if( ! arg || !arg[0] ) { /* we received no request */
 230                 warning_handler("No Args");
 231                 return OK;
 232         }
 233
 234         r->allowed |= (AP_METHOD_BIT << M_GET);
 235         r->allowed |= (AP_METHOD_BIT << M_POST);
 236
 237
 238         //char* argcopy = (char*) apr_pstrdup(p, arg);
 239
 240         //while( argcopy && (val = ap_getword(p, (const char**) &argcopy, '&'))) {
 241         while( arg && (val = ap_getword(p, (const char**) &arg, '&'))) {
 242
 243                 //const char* val2 = val;
 244
 245                 key = ap_getword(r->pool, (const char**) &val, '=');
 246                 if(!key || !key[0])
 247                         break;
 248
 249                 ap_unescape_url((char*)key);
 250                 ap_unescape_url((char*)val);
 251
 252                 if(!strcmp(key,"service"))
 253                         service = val;
 254
 255                 if(!strcmp(key,"method"))
 256                         method = val;
 257
 258                 if(!strcmp(key,"param"))
 259                         string_array_add(sarray, val);
 260
 261         }
 262
 263         info_handler("Performing(%d):  service %s | method %s | \n",
 264                         getpid(), service, method );
 265
 266         int k;
 267         for( k = 0; k!= sarray->size; k++ ) {
 268                 info_handler( "param %s", string_array_get_string(sarray,k));
 269         }
 270
 271         /*
 272         osrf_app_session* session = find_session(service,1);
 273
 274         if(!session) {
 275                 debug_handler("building new session for %s", service );
 276                 session = osrf_app_client_session_init(service);
 277                 add_session(service, session);
 278         }
 279         */
 280
 281         osrf_app_session* session = osrf_app_client_session_init(service);
 282
 283         debug_handler("MOD session service: %s", session->remote_service );
 284
 285
 286         /* connect to the remote service */
 287         /*
 288         if(!osrf_app_session_connect(session)) {
 289                 exception = json_object_new_object();
 290                 json_object_object_add( exception, "is_err", json_object_new_int(1));
 291                 json_object_object_add( exception,
 292                                 "err_msg", json_object_new_string("Unable to connect to remote service"));
 293
 294                 ap_rputs(json_object_to_json_string(exception), r );
 295                 json_object_put(exception);
 296                 return OK;
 297         }
 298         */
 299
 300         int req_id = osrf_app_session_make_req( session, NULL, method, 1, sarray );
 301         string_array_destroy(sarray);
 302
 303         osrf_message* omsg = NULL;
 304
 305         growing_buffer* result_data = buffer_init(256);
 306         buffer_add(result_data, "[");
 307
 308         /* gather result data */
 309         while((omsg = osrf_app_session_request_recv( session, req_id, 60 ))) {
 310
 311                 if( omsg->result_string ) {
 312                         buffer_add(result_data, omsg->result_string);
 313                         buffer_add( result_data, ",");
 314
 315                 } else {
 316
 317
 318                         /* build the exception information */
 319                         growing_buffer* exc_buffer = buffer_init(256);
 320                         buffer_add( exc_buffer, "\nReceived Exception:\nName: " );
 321                         buffer_add( exc_buffer, omsg->status_name );
 322                         buffer_add( exc_buffer, "\nStatus: " );
 323                         buffer_add( exc_buffer, omsg->status_text );
 324                         buffer_add( exc_buffer, "\nStatus: " );
 325
 326                         char code[16];
 327                         memset(code, 0, 16);
 328                         sprintf( code, "%d", omsg->status_code );
 329                         buffer_add( exc_buffer, code );
 330
 331                         /* build the exception object */
 332                         /*
 333                         exception = json_object_new_object();
 334                         json_object_object_add( exception, "is_err", json_object_new_int(1));
 335                         json_object_object_add( exception,
 336                                         "err_msg", json_object_new_string(exc_buffer->buf));
 337                                         */
 338
 339                         exception = json_parse_string("{}");
 340                         exception->add_key(exception, "is_err", json_parse_string("1"));
 341                         exception->add_key(exception, "err_msg", new_object(exc_buffer->buf) );
 342
 343                         warning_handler("*** Looks like we got a "
 344                                         "server exception\n%s", exc_buffer->buf );
 345
 346                         buffer_free(exc_buffer);
 347                         osrf_message_free(omsg);
 348                         break;
 349                 }
 350
 351                 osrf_message_free(omsg);
 352                 omsg = NULL;
 353         }
 354
 355         /* remove trailing comma */
 356         if( result_data->buf[strlen(result_data->buf)-1] == ',') {
 357                 result_data->buf[strlen(result_data->buf)-1] = '\0';
 358                 result_data->n_used--;
 359         }
 360
 361         buffer_add(result_data,"]");
 362
 363         char* content = NULL;
 364
 365         /* round up our data */
 366         if(exception) {
 367                 //content = strdup(json_object_to_json_string(exception));
 368                 //json_object_put(exception);
 369                 content = strdup(exception->to_json(exception));
 370                 free_object(exception);
 371         } else {
 372 #ifdef RESTGATEWAY
 373                 content = json_string_to_xml( buffer_data(result_data) );
 374 #else
 375                 content = buffer_data(result_data);
 376 #endif
 377         }
 378
 379
 380         buffer_free(result_data);
 381
 382         if(content) {
 383                 debug_handler( "APACHE writing data to web client: %s", content );
 384                 ap_rputs(content,r);
 385                 free(content);
 386         }
 387
 388         osrf_app_session_request_finish( session, req_id );
 389         debug_handler("gateway process message successfully");
 390
 391
 392         osrf_app_session_destroy(session);
 393         return OK;
 394
 395 }
 396
 397 /*
 398  * This function is a callback and it declares what other functions
 399   * should be called for request processing and configuration requests.
 400    * This callback function declares the Handlers for other events.  */
 401 static void mod_ils_gateway_register_hooks (apr_pool_t *p) {
 402 // I think this is the call to make to register a handler for method calls (GET PUT et. al.).
 403 // We will ask to be last so that the comment has a higher tendency to
 404 // go at the end.
 405         ap_hook_handler(mod_ils_gateway_method_handler, NULL, NULL, APR_HOOK_MIDDLE);
 406         ap_hook_child_init(mod_ils_gateway_child_init,NULL,NULL,APR_HOOK_MIDDLE);
 407 }
 408
 409 /*
 410  * Declare and populate the module's data structure.  The
 411   * name of this structure ('tut1_module') is important - it
 412    * must match the name of the module.  This structure is the
 413  * only "glue" between the httpd core and the module.
 414   */
 415
 416 module AP_MODULE_DECLARE_DATA ils_gateway_module =
 417 {
 418 STANDARD20_MODULE_STUFF,
 419 NULL,
 420 NULL,
 421 NULL,
 422 NULL,
 423 NULL,
 424 mod_ils_gateway_register_hooks,
 425 };
 426