src/connection.c

   1 /* This file is part of Pazpar2.
   2    Copyright (C) Index Data
   3
   4 Pazpar2 is free software; you can redistribute it and/or modify it under
   5 the terms of the GNU General Public License as published by the Free
   6 Software Foundation; either version 2, or (at your option) any later
   7 version.
   8
   9 Pazpar2 is distributed in the hope that it will be useful, but WITHOUT ANY
  10 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12 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., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  17
  18 */
  19
  20 /** \file connection.c
  21     \brief Z39.50 connection (low-level client)
  22 */
  23
  24 #if HAVE_CONFIG_H
  25 #include <config.h>
  26 #endif
  27
  28 #include <stdlib.h>
  29 #include <stdio.h>
  30 #include <string.h>
  31 #if HAVE_SYS_TIME_H
  32 #include <sys/time.h>
  33 #endif
  34 #if HAVE_UNISTD_H
  35 #include <unistd.h>
  36 #endif
  37
  38 #include <signal.h>
  39 #include <assert.h>
  40
  41 #include <yaz/log.h>
  42 #include <yaz/comstack.h>
  43 #include <yaz/tcpip.h>
  44 #include "connection.h"
  45 #include "session.h"
  46 #include "client.h"
  47 #include "settings.h"
  48
  49 /* connection counting (1) , disable connection counting (0) */
  50 #if 1
  51 static YAZ_MUTEX g_mutex = 0;
  52 static int no_connections = 0;
  53 static int total_no_connections = 0;
  54
  55 static int connection_use(int delta)
  56 {
  57     int result;
  58     if (!g_mutex)
  59         yaz_mutex_create(&g_mutex);
  60     yaz_mutex_enter(g_mutex);
  61     no_connections += delta;
  62     result = no_connections;
  63     if (delta > 0)
  64         total_no_connections += delta;
  65     yaz_mutex_leave(g_mutex);
  66     if (delta == 0)
  67             return result;
  68     yaz_log(YLOG_LOG, "%s connections=%d", delta > 0 ? "INC" : "DEC",
  69             no_connections);
  70     return result;
  71 }
  72
  73 int connections_count(void)
  74 {
  75     return connection_use(0);
  76 }
  77
  78
  79 #else
  80 #define connection_use(x)
  81 #define connections_count(x) 0
  82 #define connections_count_total(x) 0
  83 #endif
  84
  85
  86 /** \brief Represents a physical, reusable  connection to a remote Z39.50 host
  87  */
  88 struct connection {
  89     IOCHAN iochan;
  90     ZOOM_connection link;
  91     struct client *client;
  92     char *zproxy;
  93     char *url;
  94     enum {
  95         Conn_Closed,
  96         Conn_Connecting,
  97         Conn_Open
  98     } state;
  99     int operation_timeout;
 100     int session_timeout;
 101     struct connection *next; // next for same host or next in free list
 102 };
 103
 104 static int connection_connect(struct connection *con, iochan_man_t iochan_man);
 105
 106 static int connection_is_idle(struct connection *co)
 107 {
 108     ZOOM_connection link = co->link;
 109     int event;
 110
 111     if (co->state != Conn_Open || !link)
 112         return 0;
 113
 114     if (!ZOOM_connection_is_idle(link))
 115         return 0;
 116     event = ZOOM_connection_peek_event(link);
 117     if (event == ZOOM_EVENT_NONE)
 118         return 1;
 119     else
 120         return 0;
 121 }
 122
 123 ZOOM_connection connection_get_link(struct connection *co)
 124 {
 125     return co->link;
 126 }
 127
 128 // Close connection and recycle structure
 129 static void connection_destroy(struct connection *co)
 130 {
 131     if (co->link)
 132     {
 133         ZOOM_connection_destroy(co->link);
 134         iochan_destroy(co->iochan);
 135     }
 136     yaz_log(YLOG_DEBUG, "%p Connection destroy %s", co, co->url);
 137
 138     if (co->client)
 139     {
 140         client_disconnect(co->client);
 141     }
 142
 143     xfree(co->zproxy);
 144     xfree(co->url);
 145     xfree(co);
 146     connection_use(-1);
 147 }
 148
 149 // Creates a new connection for client, associated with the host of
 150 // client's database
 151 static struct connection *connection_create(struct client *cl,
 152                                             const char *url,
 153                                             const char *zproxy,
 154                                             int operation_timeout,
 155                                             int session_timeout,
 156                                             iochan_man_t iochan_man)
 157 {
 158     struct connection *co;
 159
 160     co = xmalloc(sizeof(*co));
 161
 162     co->client = cl;
 163     co->url = xstrdup(url);
 164     co->zproxy = 0;
 165     if (zproxy)
 166         co->zproxy = xstrdup(zproxy);
 167
 168     client_set_connection(cl, co);
 169     co->link = 0;
 170     co->state = Conn_Closed;
 171     co->operation_timeout = operation_timeout;
 172     co->session_timeout = session_timeout;
 173
 174     connection_connect(co, iochan_man);
 175
 176     connection_use(1);
 177     return co;
 178 }
 179
 180 static void non_block_events(struct connection *co)
 181 {
 182     int got_records = 0;
 183     IOCHAN iochan = co->iochan;
 184     ZOOM_connection link = co->link;
 185     while (1)
 186     {
 187         struct client *cl = co->client;
 188         int ev;
 189         int r = ZOOM_event_nonblock(1, &link);
 190         if (!r)
 191             break;
 192         if (!cl)
 193             continue;
 194         ev = ZOOM_connection_last_event(link);
 195
 196 #if 1
 197         yaz_log(YLOG_DEBUG, "%p Connection ZOOM_EVENT_%s", co, ZOOM_get_event_str(ev));
 198 #endif
 199         switch (ev)
 200         {
 201         case ZOOM_EVENT_TIMEOUT:
 202             break;
 203         case ZOOM_EVENT_END:
 204             {
 205                 const char *error, *addinfo;
 206                 int err;
 207                 if ((err = ZOOM_connection_error(link, &error, &addinfo)))
 208                 {
 209                     yaz_log(YLOG_LOG, "Error %s from %s",
 210                             error, client_get_id(cl));
 211                     client_set_diagnostic(cl, err, error, addinfo);
 212                     client_set_state(cl, Client_Error);
 213                 }
 214                 else
 215                 {
 216                     iochan_settimeout(iochan, co->session_timeout);
 217                     client_set_state(cl, Client_Idle);
 218                 }
 219             }
 220             break;
 221         case ZOOM_EVENT_SEND_DATA:
 222             break;
 223         case ZOOM_EVENT_RECV_DATA:
 224             break;
 225         case ZOOM_EVENT_UNKNOWN:
 226             break;
 227         case ZOOM_EVENT_SEND_APDU:
 228             client_set_state(co->client, Client_Working);
 229             iochan_settimeout(iochan, co->operation_timeout);
 230             break;
 231         case ZOOM_EVENT_RECV_APDU:
 232             break;
 233         case ZOOM_EVENT_CONNECT:
 234             yaz_log(YLOG_LOG, "Connected to %s", client_get_id(cl));
 235             co->state = Conn_Open;
 236             break;
 237         case ZOOM_EVENT_RECV_SEARCH:
 238             client_search_response(cl);
 239             break;
 240         case ZOOM_EVENT_RECV_RECORD:
 241             client_record_response(cl, &got_records);
 242             break;
 243         case ZOOM_EVENT_NONE:
 244             break;
 245         default:
 246             yaz_log(YLOG_LOG, "Unhandled event (%d) from %s",
 247                     ev, client_get_id(cl));
 248             break;
 249         }
 250     }
 251     if (got_records)
 252     {
 253         struct client *cl = co->client;
 254         if (cl)
 255         {
 256             client_check_preferred_watch(cl);
 257             client_got_records(cl);
 258         }
 259     }
 260 }
 261
 262 static void iochan_update(struct connection *co)
 263 {
 264     if (co->link)
 265     {
 266         int m = ZOOM_connection_get_mask(co->link);
 267
 268         if (m == 0)
 269             m = ZOOM_SELECT_READ;
 270         iochan_setflags(co->iochan, m);
 271         iochan_setfd(co->iochan, ZOOM_connection_get_socket(co->link));
 272     }
 273 }
 274
 275 void connection_continue(struct connection *co)
 276 {
 277     int r = ZOOM_connection_exec_task(co->link);
 278     if (!r)
 279     {
 280         struct client *cl = co->client;
 281
 282         client_lock(cl);
 283         non_block_events(co);
 284         client_unlock(cl);
 285     }
 286     else
 287         iochan_update(co);
 288 }
 289
 290 static void connection_handler(IOCHAN iochan, int event)
 291 {
 292     struct connection *co = iochan_getdata(iochan);
 293     struct client *cl;
 294
 295     cl = co->client;
 296     if (!cl)
 297     {
 298         /* no client associated with it.. We are probably getting
 299            a closed connection from the target.. Or, perhaps, an unexpected
 300            package.. We will just close the connection */
 301         yaz_log(YLOG_LOG, "timeout connection %p event=%d", co, event);
 302         connection_destroy(co);
 303     }
 304     else if (event & EVENT_TIMEOUT)
 305     {
 306         ZOOM_connection_fire_event_timeout(co->link);
 307         client_lock(cl);
 308         non_block_events(co);
 309         client_unlock(cl);
 310
 311         connection_destroy(co);
 312     }
 313     else
 314     {
 315         if (ZOOM_connection_is_idle(co->link))
 316         {
 317             connection_destroy(co);
 318             return;
 319         }
 320         client_lock(cl);
 321         non_block_events(co);
 322
 323         ZOOM_connection_fire_event_socket(co->link, event);
 324
 325         non_block_events(co);
 326         client_unlock(cl);
 327
 328         iochan_update(co);
 329     }
 330 }
 331
 332
 333 // Disassociate connection from client
 334 static void connection_release(struct connection *co)
 335 {
 336     struct client *cl = co->client;
 337
 338     if (!cl)
 339         return;
 340     client_set_connection(cl, 0);
 341     co->client = 0;
 342 }
 343
 344 static int connection_connect(struct connection *con, iochan_man_t iochan_man)
 345 {
 346     ZOOM_options zoptions = ZOOM_options_create();
 347     const char *auth;
 348     const char *charset;
 349     const char *sru;
 350     const char *sru_version = 0;
 351     const char *value;
 352     WRBUF w;
 353
 354     struct session_database *sdb = client_get_database(con->client);
 355     const char *apdulog = session_setting_oneval(sdb, PZ_APDULOG);
 356     const char *memcached = session_setting_oneval(sdb, PZ_MEMCACHED);
 357
 358     assert(con);
 359
 360     ZOOM_options_set(zoptions, "async", "1");
 361     ZOOM_options_set(zoptions, "implementationName", PACKAGE_NAME);
 362     ZOOM_options_set(zoptions, "implementationVersion", VERSION);
 363
 364     if ((charset = session_setting_oneval(sdb, PZ_NEGOTIATION_CHARSET)))
 365         ZOOM_options_set(zoptions, "charset", charset);
 366     if (memcached && *memcached)
 367         ZOOM_options_set(zoptions, "memcached", memcached);
 368
 369     if (con->zproxy)
 370     {
 371         yaz_log(YLOG_LOG, "proxy=%s", con->zproxy);
 372         ZOOM_options_set(zoptions, "proxy", con->zproxy);
 373     }
 374     if (apdulog && *apdulog)
 375         ZOOM_options_set(zoptions, "apdulog", apdulog);
 376
 377
 378     if ((sru = session_setting_oneval(sdb, PZ_SRU)) && *sru)
 379         ZOOM_options_set(zoptions, "sru", sru);
 380     if ((sru_version = session_setting_oneval(sdb, PZ_SRU_VERSION))
 381         && *sru_version)
 382         ZOOM_options_set(zoptions, "sru_version", sru_version);
 383
 384     if ((auth = session_setting_oneval(sdb, PZ_AUTHENTICATION)))
 385     {
 386         /* allow splitting user and reset with a blank always */
 387         const char *cp1 = strchr(auth, ' ');
 388         if (!cp1 && sru && *sru)
 389             cp1 =  strchr(auth, '/');
 390         if (!cp1)
 391         {
 392             /* Z39.50 user/password style, or no password for SRU */
 393             ZOOM_options_set(zoptions, "user", auth);
 394         }
 395         else
 396         {
 397             /* now consider group as well */
 398             const char *cp2 = strchr(cp1 + 1, ' ');
 399
 400             ZOOM_options_setl(zoptions, "user", auth, cp1 - auth);
 401             if (!cp2)
 402                 ZOOM_options_set(zoptions, "password", cp1 + 1);
 403             else
 404             {
 405                 ZOOM_options_setl(zoptions, "group", cp1 + 1, cp2 - cp1 - 1);
 406                 ZOOM_options_set(zoptions, "password", cp2 + 1);
 407             }
 408         }
 409     }
 410
 411     value = session_setting_oneval(sdb, PZ_AUTHENTICATION_MODE);
 412     if (value && *value)
 413         ZOOM_options_set(zoptions, "authenticationMode", value);
 414
 415     if (!(con->link = ZOOM_connection_create(zoptions)))
 416     {
 417         yaz_log(YLOG_FATAL|YLOG_ERRNO, "Failed to create ZOOM Connection");
 418         ZOOM_options_destroy(zoptions);
 419         return -1;
 420     }
 421
 422     w = wrbuf_alloc();
 423     if (sru && *sru && !strstr(con->url, "://"))
 424         wrbuf_puts(w, "http://");
 425     if (strchr(con->url, '#'))
 426     {
 427         const char *cp = strchr(con->url, '#');
 428         wrbuf_write(w, con->url, cp - con->url);
 429     }
 430     else
 431         wrbuf_puts(w, con->url);
 432
 433     ZOOM_connection_connect(con->link, wrbuf_cstr(w), 0);
 434
 435     con->iochan = iochan_create(-1, connection_handler, 0, "connection_socket");
 436     con->state = Conn_Connecting;
 437     iochan_settimeout(con->iochan, con->operation_timeout);
 438     iochan_setdata(con->iochan, con);
 439     iochan_add(iochan_man, con->iochan);
 440
 441     client_set_state(con->client, Client_Connecting);
 442     ZOOM_options_destroy(zoptions);
 443     wrbuf_destroy(w);
 444     return 0;
 445 }
 446
 447 // Ensure that client has a connection associated
 448 int client_prep_connection(struct client *cl,
 449                            int operation_timeout, int session_timeout,
 450                            iochan_man_t iochan_man,
 451                            const struct timeval *abstime)
 452 {
 453     struct connection *co;
 454     struct session_database *sdb = client_get_database(cl);
 455     const char *zproxy = session_setting_oneval(sdb, PZ_ZPROXY);
 456     const char *url = session_setting_oneval(sdb, PZ_URL);
 457
 458     if (zproxy && zproxy[0] == '\0')
 459         zproxy = 0;
 460
 461     if (!url || !*url)
 462         url = sdb->database->id;
 463
 464     yaz_log(YLOG_DEBUG, "client_prep_connection: target=%s url=%s",
 465             client_get_id(cl), url);
 466
 467     co = client_get_connection(cl);
 468     if (!co)
 469     {
 470         co = connection_create(cl, url, zproxy,
 471                                operation_timeout, session_timeout,
 472                                iochan_man);
 473     }
 474
 475     if (co && co->link)
 476         return 1;
 477     else
 478         return 0;
 479 }
 480
 481 /*
 482  * Local variables:
 483  * c-basic-offset: 4
 484  * c-file-style: "Stroustrup"
 485  * indent-tabs-mode: nil
 486  * End:
 487  * vim: shiftwidth=4 tabstop=8 expandtab
 488  */
 489