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