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     int ret;
 148
 149     co = xmalloc(sizeof(*co));
 150
 151     co->client = cl;
 152     co->url = xstrdup(url);
 153     co->zproxy = 0;
 154     if (zproxy)
 155         co->zproxy = xstrdup(zproxy);
 156
 157     client_set_connection(cl, co);
 158     co->link = 0;
 159     co->state = Conn_Closed;
 160     co->operation_timeout = operation_timeout;
 161     co->session_timeout = session_timeout;
 162
 163     ret = connection_connect(co, iochan_man);
 164     connection_use(1);
 165     if (ret)
 166     {   /* error */
 167         connection_destroy(co);
 168         co = 0;
 169     }
 170     return co;
 171 }
 172
 173 static void non_block_events(struct connection *co)
 174 {
 175     int got_records = 0;
 176     IOCHAN iochan = co->iochan;
 177     ZOOM_connection link = co->link;
 178     while (1)
 179     {
 180         struct client *cl = co->client;
 181         int ev;
 182         int r = ZOOM_event_nonblock(1, &link);
 183         if (!r)
 184             break;
 185         if (!cl)
 186             continue;
 187         ev = ZOOM_connection_last_event(link);
 188
 189 #if 1
 190         yaz_log(YLOG_DEBUG, "%p Connection ZOOM_EVENT_%s", co, ZOOM_get_event_str(ev));
 191 #endif
 192         switch (ev)
 193         {
 194         case ZOOM_EVENT_TIMEOUT:
 195             break;
 196         case ZOOM_EVENT_END:
 197             {
 198                 const char *error, *addinfo;
 199                 int err;
 200                 if ((err = ZOOM_connection_error(link, &error, &addinfo)))
 201                 {
 202                     struct session *se = client_get_session(cl);
 203
 204                     session_log(se, YLOG_WARN, "%s: Error %s (%s)",
 205                                 client_get_id(cl), error, addinfo);
 206                     client_set_diagnostic(cl, err, error, addinfo);
 207                     client_set_state(cl, Client_Error);
 208                 }
 209                 else
 210                 {
 211                     iochan_settimeout(iochan, co->session_timeout);
 212                     client_set_state(cl, Client_Idle);
 213                 }
 214             }
 215             break;
 216         case ZOOM_EVENT_SEND_DATA:
 217             break;
 218         case ZOOM_EVENT_RECV_DATA:
 219             break;
 220         case ZOOM_EVENT_UNKNOWN:
 221             break;
 222         case ZOOM_EVENT_SEND_APDU:
 223             client_set_state(co->client, Client_Working);
 224             iochan_settimeout(iochan, co->operation_timeout);
 225             break;
 226         case ZOOM_EVENT_RECV_APDU:
 227             break;
 228         case ZOOM_EVENT_CONNECT:
 229             co->state = Conn_Open;
 230             break;
 231         case ZOOM_EVENT_RECV_SEARCH:
 232             client_search_response(cl);
 233             break;
 234         case ZOOM_EVENT_RECV_RECORD:
 235             client_record_response(cl, &got_records);
 236             break;
 237         case ZOOM_EVENT_NONE:
 238             break;
 239         default:
 240             yaz_log(YLOG_LOG, "Unhandled event (%d) from %s",
 241                     ev, client_get_id(cl));
 242             break;
 243         }
 244     }
 245     if (got_records)
 246     {
 247         struct client *cl = co->client;
 248         if (cl)
 249             client_got_records(cl);
 250     }
 251 }
 252
 253 static void iochan_update(struct connection *co)
 254 {
 255     if (co->link)
 256     {
 257         int m = ZOOM_connection_get_mask(co->link);
 258
 259         if (m == 0)
 260             m = ZOOM_SELECT_READ;
 261         iochan_setflags(co->iochan, m);
 262         iochan_setfd(co->iochan, ZOOM_connection_get_socket(co->link));
 263     }
 264 }
 265
 266 void connection_continue(struct connection *co)
 267 {
 268     int r = ZOOM_connection_exec_task(co->link);
 269     if (!r)
 270     {
 271         struct client *cl = co->client;
 272
 273         client_lock(cl);
 274         non_block_events(co);
 275         client_unlock(cl);
 276     }
 277     else
 278         iochan_update(co);
 279 }
 280
 281 static void connection_handler(IOCHAN iochan, int event)
 282 {
 283     struct connection *co = iochan_getdata(iochan);
 284     struct client *cl;
 285
 286     cl = co->client;
 287     if (!cl)
 288     {
 289         /* no client associated with it.. We are probably getting
 290            a closed connection from the target.. Or, perhaps, an unexpected
 291            package.. We will just close the connection */
 292         yaz_log(YLOG_LOG, "timeout connection %p event=%d", co, event);
 293         connection_destroy(co);
 294     }
 295     else if (event & EVENT_TIMEOUT)
 296     {
 297         ZOOM_connection_fire_event_timeout(co->link);
 298         client_lock(cl);
 299         non_block_events(co);
 300         client_unlock(cl);
 301
 302         connection_destroy(co);
 303     }
 304     else
 305     {
 306         if (ZOOM_connection_is_idle(co->link))
 307         {
 308             connection_destroy(co);
 309             return;
 310         }
 311         client_lock(cl);
 312         non_block_events(co);
 313
 314         ZOOM_connection_fire_event_socket(co->link, event);
 315
 316         non_block_events(co);
 317         client_unlock(cl);
 318
 319         iochan_update(co);
 320     }
 321 }
 322
 323 void connection_release2(struct connection *co)
 324 {
 325     co->client = 0;
 326 }
 327
 328 static int connection_connect(struct connection *con, iochan_man_t iochan_man)
 329 {
 330     ZOOM_options zoptions = ZOOM_options_create();
 331     const char *auth;
 332     const char *charset;
 333     const char *sru;
 334     const char *sru_version = 0;
 335     const char *value;
 336     int r = 0;
 337     WRBUF w;
 338
 339     struct session_database *sdb = client_get_database(con->client);
 340     const char *apdulog = session_setting_oneval(sdb, PZ_APDULOG);
 341     const char *memcached = session_setting_oneval(sdb, PZ_MEMCACHED);
 342     const char *redis = session_setting_oneval(sdb, PZ_REDIS);
 343
 344     assert(con);
 345
 346     ZOOM_options_set(zoptions, "async", "1");
 347     ZOOM_options_set(zoptions, "implementationName", PACKAGE_NAME);
 348     ZOOM_options_set(zoptions, "implementationVersion", VERSION);
 349
 350     if ((charset = session_setting_oneval(sdb, PZ_NEGOTIATION_CHARSET)))
 351         ZOOM_options_set(zoptions, "charset", charset);
 352     if (memcached && *memcached)
 353         ZOOM_options_set(zoptions, "memcached", memcached);
 354     if (redis && *redis)
 355         ZOOM_options_set(zoptions, "redis", redis);
 356
 357     if (con->zproxy)
 358     {
 359         yaz_log(YLOG_LOG, "proxy=%s", con->zproxy);
 360         ZOOM_options_set(zoptions, "proxy", con->zproxy);
 361     }
 362     if (apdulog && *apdulog)
 363         ZOOM_options_set(zoptions, "apdulog", apdulog);
 364
 365
 366     if ((sru = session_setting_oneval(sdb, PZ_SRU)) && *sru)
 367         ZOOM_options_set(zoptions, "sru", sru);
 368     if ((sru_version = session_setting_oneval(sdb, PZ_SRU_VERSION))
 369         && *sru_version)
 370         ZOOM_options_set(zoptions, "sru_version", sru_version);
 371
 372     if ((auth = session_setting_oneval(sdb, PZ_AUTHENTICATION)))
 373     {
 374         /* allow splitting user and reset with a blank always */
 375         const char *cp1 = strchr(auth, ' ');
 376         if (!cp1 && sru && *sru)
 377             cp1 =  strchr(auth, '/');
 378         if (!cp1)
 379         {
 380             /* Z39.50 user/password style, or no password for SRU */
 381             ZOOM_options_set(zoptions, "user", auth);
 382         }
 383         else
 384         {
 385             /* now consider group as well */
 386             const char *cp2 = strchr(cp1 + 1, ' ');
 387
 388             ZOOM_options_setl(zoptions, "user", auth, cp1 - auth);
 389             if (!cp2)
 390                 ZOOM_options_set(zoptions, "password", cp1 + 1);
 391             else
 392             {
 393                 ZOOM_options_setl(zoptions, "group", cp1 + 1, cp2 - cp1 - 1);
 394                 ZOOM_options_set(zoptions, "password", cp2 + 1);
 395             }
 396         }
 397     }
 398
 399     value = session_setting_oneval(sdb, PZ_AUTHENTICATION_MODE);
 400     if (value && *value)
 401         ZOOM_options_set(zoptions, "authenticationMode", value);
 402
 403     if (!(con->link = ZOOM_connection_create(zoptions)))
 404     {
 405         yaz_log(YLOG_FATAL|YLOG_ERRNO, "Failed to create ZOOM Connection");
 406         ZOOM_options_destroy(zoptions);
 407         return -1;
 408     }
 409
 410     w = wrbuf_alloc();
 411     if (sru && *sru && !strstr(con->url, "://"))
 412         wrbuf_puts(w, "http://");
 413     if (strchr(con->url, '#'))
 414     {
 415         const char *cp = strchr(con->url, '#');
 416         wrbuf_write(w, con->url, cp - con->url);
 417     }
 418     else
 419         wrbuf_puts(w, con->url);
 420
 421     ZOOM_connection_connect(con->link, wrbuf_cstr(w), 0);
 422
 423     con->iochan = iochan_create(-1, connection_handler, 0, "connection_socket");
 424     con->state = Conn_Connecting;
 425     iochan_settimeout(con->iochan, con->operation_timeout);
 426     iochan_setdata(con->iochan, con);
 427     if (iochan_add(iochan_man, con->iochan))
 428     {
 429         yaz_log(YLOG_FATAL, "Out of connections");
 430         iochan_destroy(con->iochan);
 431         con->iochan = 0;
 432         ZOOM_connection_destroy(con->link);
 433         con->link = 0;
 434         r = -1;
 435     }
 436     else
 437     {
 438         client_set_state(con->client, Client_Connecting);
 439     }
 440     ZOOM_options_destroy(zoptions);
 441     wrbuf_destroy(w);
 442     return r;
 443 }
 444
 445 // Ensure that client has a connection associated
 446 int client_prep_connection(struct client *cl,
 447                            int operation_timeout, int session_timeout,
 448                            iochan_man_t iochan_man,
 449                            const struct timeval *abstime)
 450 {
 451     struct connection *co;
 452     struct session_database *sdb = client_get_database(cl);
 453     const char *zproxy = session_setting_oneval(sdb, PZ_ZPROXY);
 454     const char *url = session_setting_oneval(sdb, PZ_URL);
 455
 456     if (zproxy && zproxy[0] == '\0')
 457         zproxy = 0;
 458
 459     if (!url || !*url)
 460         url = sdb->database->id;
 461
 462     yaz_log(YLOG_DEBUG, "client_prep_connection: target=%s url=%s",
 463             client_get_id(cl), url);
 464
 465     co = client_get_connection(cl);
 466     if (co)
 467         return 2;
 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