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 ZOOM_connection connection_get_link(struct connection *co)
 107 {
 108     return co->link;
 109 }
 110
 111 void connection_mark_dead(struct connection *co)
 112 {
 113     iochan_settimeout(co->iochan, 1);
 114 }
 115
 116 // Close connection and recycle structure
 117 static void connection_destroy(struct connection *co)
 118 {
 119     if (co->link)
 120     {
 121         ZOOM_connection_destroy(co->link);
 122         iochan_destroy(co->iochan);
 123     }
 124     yaz_log(YLOG_DEBUG, "%p Connection destroy %s", co, co->url);
 125
 126     if (co->client)
 127     {
 128         client_disconnect(co->client);
 129     }
 130
 131     xfree(co->zproxy);
 132     xfree(co->url);
 133     xfree(co);
 134     connection_use(-1);
 135 }
 136
 137 // Creates a new connection for client, associated with the host of
 138 // client's database
 139 static struct connection *connection_create(struct client *cl,
 140                                             const char *url,
 141                                             const char *zproxy,
 142                                             int operation_timeout,
 143                                             int session_timeout,
 144                                             iochan_man_t iochan_man)
 145 {
 146     struct connection *co;
 147
 148     co = xmalloc(sizeof(*co));
 149
 150     co->client = cl;
 151     co->url = xstrdup(url);
 152     co->zproxy = 0;
 153     if (zproxy)
 154         co->zproxy = xstrdup(zproxy);
 155
 156     client_set_connection(cl, co);
 157     co->link = 0;
 158     co->state = Conn_Closed;
 159     co->operation_timeout = operation_timeout;
 160     co->session_timeout = session_timeout;
 161
 162     connection_connect(co, iochan_man);
 163
 164     connection_use(1);
 165     return co;
 166 }
 167
 168 static void non_block_events(struct connection *co)
 169 {
 170     int got_records = 0;
 171     IOCHAN iochan = co->iochan;
 172     ZOOM_connection link = co->link;
 173     while (1)
 174     {
 175         struct client *cl = co->client;
 176         int ev;
 177         int r = ZOOM_event_nonblock(1, &link);
 178         if (!r)
 179             break;
 180         if (!cl)
 181             continue;
 182         ev = ZOOM_connection_last_event(link);
 183
 184 #if 1
 185         yaz_log(YLOG_DEBUG, "%p Connection ZOOM_EVENT_%s", co, ZOOM_get_event_str(ev));
 186 #endif
 187         switch (ev)
 188         {
 189         case ZOOM_EVENT_TIMEOUT:
 190             break;
 191         case ZOOM_EVENT_END:
 192             {
 193                 const char *error, *addinfo;
 194                 int err;
 195                 if ((err = ZOOM_connection_error(link, &error, &addinfo)))
 196                 {
 197                     struct session *se = client_get_session(cl);
 198
 199                     session_log(se, YLOG_WARN, "%s: Error %s (%s)",
 200                                 client_get_id(cl), error, addinfo);
 201                     client_set_diagnostic(cl, err, error, addinfo);
 202                     client_set_state(cl, Client_Error);
 203                 }
 204                 else
 205                 {
 206                     iochan_settimeout(iochan, co->session_timeout);
 207                     client_set_state(cl, Client_Idle);
 208                 }
 209             }
 210             break;
 211         case ZOOM_EVENT_SEND_DATA:
 212             break;
 213         case ZOOM_EVENT_RECV_DATA:
 214             break;
 215         case ZOOM_EVENT_UNKNOWN:
 216             break;
 217         case ZOOM_EVENT_SEND_APDU:
 218             client_set_state(co->client, Client_Working);
 219             iochan_settimeout(iochan, co->operation_timeout);
 220             break;
 221         case ZOOM_EVENT_RECV_APDU:
 222             break;
 223         case ZOOM_EVENT_CONNECT:
 224             co->state = Conn_Open;
 225             break;
 226         case ZOOM_EVENT_RECV_SEARCH:
 227             client_search_response(cl);
 228             break;
 229         case ZOOM_EVENT_RECV_RECORD:
 230             client_record_response(cl, &got_records);
 231             break;
 232         case ZOOM_EVENT_NONE:
 233             break;
 234         default:
 235             yaz_log(YLOG_LOG, "Unhandled event (%d) from %s",
 236                     ev, client_get_id(cl));
 237             break;
 238         }
 239     }
 240     if (got_records)
 241     {
 242         struct client *cl = co->client;
 243         if (cl)
 244         {
 245             client_check_preferred_watch(cl);
 246             client_got_records(cl);
 247         }
 248     }
 249 }
 250
 251 static void iochan_update(struct connection *co)
 252 {
 253     if (co->link)
 254     {
 255         int m = ZOOM_connection_get_mask(co->link);
 256
 257         if (m == 0)
 258             m = ZOOM_SELECT_READ;
 259         iochan_setflags(co->iochan, m);
 260         iochan_setfd(co->iochan, ZOOM_connection_get_socket(co->link));
 261     }
 262 }
 263
 264 void connection_continue(struct connection *co)
 265 {
 266     int r = ZOOM_connection_exec_task(co->link);
 267     if (!r)
 268     {
 269         struct client *cl = co->client;
 270
 271         client_lock(cl);
 272         non_block_events(co);
 273         client_unlock(cl);
 274     }
 275     else
 276         iochan_update(co);
 277 }
 278
 279 static void connection_handler(IOCHAN iochan, int event)
 280 {
 281     struct connection *co = iochan_getdata(iochan);
 282     struct client *cl;
 283
 284     cl = co->client;
 285     if (!cl)
 286     {
 287         /* no client associated with it.. We are probably getting
 288            a closed connection from the target.. Or, perhaps, an unexpected
 289            package.. We will just close the connection */
 290         yaz_log(YLOG_LOG, "timeout connection %p event=%d", co, event);
 291         connection_destroy(co);
 292     }
 293     else if (event & EVENT_TIMEOUT)
 294     {
 295         ZOOM_connection_fire_event_timeout(co->link);
 296         client_lock(cl);
 297         non_block_events(co);
 298         client_unlock(cl);
 299
 300         connection_destroy(co);
 301     }
 302     else
 303     {
 304         if (ZOOM_connection_is_idle(co->link))
 305         {
 306             connection_destroy(co);
 307             return;
 308         }
 309         client_lock(cl);
 310         non_block_events(co);
 311
 312         ZOOM_connection_fire_event_socket(co->link, event);
 313
 314         non_block_events(co);
 315         client_unlock(cl);
 316
 317         iochan_update(co);
 318     }
 319 }
 320
 321 void connection_release2(struct connection *co)
 322 {
 323     co->client = 0;
 324 }
 325
 326 static int connection_connect(struct connection *con, iochan_man_t iochan_man)
 327 {
 328     ZOOM_options zoptions = ZOOM_options_create();
 329     const char *auth;
 330     const char *charset;
 331     const char *sru;
 332     const char *sru_version = 0;
 333     const char *value;
 334     WRBUF w;
 335
 336     struct session_database *sdb = client_get_database(con->client);
 337     const char *apdulog = session_setting_oneval(sdb, PZ_APDULOG);
 338     const char *memcached = session_setting_oneval(sdb, PZ_MEMCACHED);
 339     const char *redis = session_setting_oneval(sdb, PZ_REDIS);
 340
 341     assert(con);
 342
 343     ZOOM_options_set(zoptions, "async", "1");
 344     ZOOM_options_set(zoptions, "implementationName", PACKAGE_NAME);
 345     ZOOM_options_set(zoptions, "implementationVersion", VERSION);
 346
 347     if ((charset = session_setting_oneval(sdb, PZ_NEGOTIATION_CHARSET)))
 348         ZOOM_options_set(zoptions, "charset", charset);
 349     if (memcached && *memcached)
 350         ZOOM_options_set(zoptions, "memcached", memcached);
 351     if (redis && *redis)
 352         ZOOM_options_set(zoptions, "redis", redis);
 353
 354     if (con->zproxy)
 355     {
 356         yaz_log(YLOG_LOG, "proxy=%s", con->zproxy);
 357         ZOOM_options_set(zoptions, "proxy", con->zproxy);
 358     }
 359     if (apdulog && *apdulog)
 360         ZOOM_options_set(zoptions, "apdulog", apdulog);
 361
 362
 363     if ((sru = session_setting_oneval(sdb, PZ_SRU)) && *sru)
 364         ZOOM_options_set(zoptions, "sru", sru);
 365     if ((sru_version = session_setting_oneval(sdb, PZ_SRU_VERSION))
 366         && *sru_version)
 367         ZOOM_options_set(zoptions, "sru_version", sru_version);
 368
 369     if ((auth = session_setting_oneval(sdb, PZ_AUTHENTICATION)))
 370     {
 371         /* allow splitting user and reset with a blank always */
 372         const char *cp1 = strchr(auth, ' ');
 373         if (!cp1 && sru && *sru)
 374             cp1 =  strchr(auth, '/');
 375         if (!cp1)
 376         {
 377             /* Z39.50 user/password style, or no password for SRU */
 378             ZOOM_options_set(zoptions, "user", auth);
 379         }
 380         else
 381         {
 382             /* now consider group as well */
 383             const char *cp2 = strchr(cp1 + 1, ' ');
 384
 385             ZOOM_options_setl(zoptions, "user", auth, cp1 - auth);
 386             if (!cp2)
 387                 ZOOM_options_set(zoptions, "password", cp1 + 1);
 388             else
 389             {
 390                 ZOOM_options_setl(zoptions, "group", cp1 + 1, cp2 - cp1 - 1);
 391                 ZOOM_options_set(zoptions, "password", cp2 + 1);
 392             }
 393         }
 394     }
 395
 396     value = session_setting_oneval(sdb, PZ_AUTHENTICATION_MODE);
 397     if (value && *value)
 398         ZOOM_options_set(zoptions, "authenticationMode", value);
 399
 400     if (!(con->link = ZOOM_connection_create(zoptions)))
 401     {
 402         yaz_log(YLOG_FATAL|YLOG_ERRNO, "Failed to create ZOOM Connection");
 403         ZOOM_options_destroy(zoptions);
 404         return -1;
 405     }
 406
 407     w = wrbuf_alloc();
 408     if (sru && *sru && !strstr(con->url, "://"))
 409         wrbuf_puts(w, "http://");
 410     if (strchr(con->url, '#'))
 411     {
 412         const char *cp = strchr(con->url, '#');
 413         wrbuf_write(w, con->url, cp - con->url);
 414     }
 415     else
 416         wrbuf_puts(w, con->url);
 417
 418     ZOOM_connection_connect(con->link, wrbuf_cstr(w), 0);
 419
 420     con->iochan = iochan_create(-1, connection_handler, 0, "connection_socket");
 421     con->state = Conn_Connecting;
 422     iochan_settimeout(con->iochan, con->operation_timeout);
 423     iochan_setdata(con->iochan, con);
 424     iochan_add(iochan_man, con->iochan);
 425
 426     client_set_state(con->client, Client_Connecting);
 427     ZOOM_options_destroy(zoptions);
 428     wrbuf_destroy(w);
 429     return 0;
 430 }
 431
 432 // Ensure that client has a connection associated
 433 int client_prep_connection(struct client *cl,
 434                            int operation_timeout, int session_timeout,
 435                            iochan_man_t iochan_man,
 436                            const struct timeval *abstime)
 437 {
 438     struct connection *co;
 439     struct session_database *sdb = client_get_database(cl);
 440     const char *zproxy = session_setting_oneval(sdb, PZ_ZPROXY);
 441     const char *url = session_setting_oneval(sdb, PZ_URL);
 442
 443     if (zproxy && zproxy[0] == '\0')
 444         zproxy = 0;
 445
 446     if (!url || !*url)
 447         url = sdb->database->id;
 448
 449     yaz_log(YLOG_DEBUG, "client_prep_connection: target=%s url=%s",
 450             client_get_id(cl), url);
 451
 452     co = client_get_connection(cl);
 453     if (!co)
 454     {
 455         co = connection_create(cl, url, zproxy,
 456                                operation_timeout, session_timeout,
 457                                iochan_man);
 458     }
 459
 460     if (co && co->link)
 461         return 1;
 462     else
 463         return 0;
 464 }
 465
 466 /*
 467  * Local variables:
 468  * c-basic-offset: 4
 469  * c-file-style: "Stroustrup"
 470  * indent-tabs-mode: nil
 471  * End:
 472  * vim: shiftwidth=4 tabstop=8 expandtab
 473  */
 474