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                     yaz_log(YLOG_LOG, "Error %s from %s",
 198                             error, client_get_id(cl));
 199                     client_set_diagnostic(cl, err, error, addinfo);
 200                     client_set_state(cl, Client_Error);
 201                 }
 202                 else
 203                 {
 204                     iochan_settimeout(iochan, co->session_timeout);
 205                     client_set_state(cl, Client_Idle);
 206                 }
 207             }
 208             break;
 209         case ZOOM_EVENT_SEND_DATA:
 210             break;
 211         case ZOOM_EVENT_RECV_DATA:
 212             break;
 213         case ZOOM_EVENT_UNKNOWN:
 214             break;
 215         case ZOOM_EVENT_SEND_APDU:
 216             client_set_state(co->client, Client_Working);
 217             iochan_settimeout(iochan, co->operation_timeout);
 218             break;
 219         case ZOOM_EVENT_RECV_APDU:
 220             break;
 221         case ZOOM_EVENT_CONNECT:
 222             yaz_log(YLOG_LOG, "Connected to %s", client_get_id(cl));
 223             co->state = Conn_Open;
 224             break;
 225         case ZOOM_EVENT_RECV_SEARCH:
 226             client_search_response(cl);
 227             break;
 228         case ZOOM_EVENT_RECV_RECORD:
 229             client_record_response(cl, &got_records);
 230             break;
 231         case ZOOM_EVENT_NONE:
 232             break;
 233         default:
 234             yaz_log(YLOG_LOG, "Unhandled event (%d) from %s",
 235                     ev, client_get_id(cl));
 236             break;
 237         }
 238     }
 239     if (got_records)
 240     {
 241         struct client *cl = co->client;
 242         if (cl)
 243         {
 244             client_check_preferred_watch(cl);
 245             client_got_records(cl);
 246         }
 247     }
 248 }
 249
 250 static void iochan_update(struct connection *co)
 251 {
 252     if (co->link)
 253     {
 254         int m = ZOOM_connection_get_mask(co->link);
 255
 256         if (m == 0)
 257             m = ZOOM_SELECT_READ;
 258         iochan_setflags(co->iochan, m);
 259         iochan_setfd(co->iochan, ZOOM_connection_get_socket(co->link));
 260     }
 261 }
 262
 263 void connection_continue(struct connection *co)
 264 {
 265     int r = ZOOM_connection_exec_task(co->link);
 266     if (!r)
 267     {
 268         struct client *cl = co->client;
 269
 270         client_lock(cl);
 271         non_block_events(co);
 272         client_unlock(cl);
 273     }
 274     else
 275         iochan_update(co);
 276 }
 277
 278 static void connection_handler(IOCHAN iochan, int event)
 279 {
 280     struct connection *co = iochan_getdata(iochan);
 281     struct client *cl;
 282
 283     cl = co->client;
 284     if (!cl)
 285     {
 286         /* no client associated with it.. We are probably getting
 287            a closed connection from the target.. Or, perhaps, an unexpected
 288            package.. We will just close the connection */
 289         yaz_log(YLOG_LOG, "timeout connection %p event=%d", co, event);
 290         connection_destroy(co);
 291     }
 292     else if (event & EVENT_TIMEOUT)
 293     {
 294         ZOOM_connection_fire_event_timeout(co->link);
 295         client_lock(cl);
 296         non_block_events(co);
 297         client_unlock(cl);
 298
 299         connection_destroy(co);
 300     }
 301     else
 302     {
 303         if (ZOOM_connection_is_idle(co->link))
 304         {
 305             connection_destroy(co);
 306             return;
 307         }
 308         client_lock(cl);
 309         non_block_events(co);
 310
 311         ZOOM_connection_fire_event_socket(co->link, event);
 312
 313         non_block_events(co);
 314         client_unlock(cl);
 315
 316         iochan_update(co);
 317     }
 318 }
 319
 320 static int connection_connect(struct connection *con, iochan_man_t iochan_man)
 321 {
 322     ZOOM_options zoptions = ZOOM_options_create();
 323     const char *auth;
 324     const char *charset;
 325     const char *sru;
 326     const char *sru_version = 0;
 327     const char *value;
 328     WRBUF w;
 329
 330     struct session_database *sdb = client_get_database(con->client);
 331     const char *apdulog = session_setting_oneval(sdb, PZ_APDULOG);
 332     const char *memcached = session_setting_oneval(sdb, PZ_MEMCACHED);
 333
 334     assert(con);
 335
 336     ZOOM_options_set(zoptions, "async", "1");
 337     ZOOM_options_set(zoptions, "implementationName", PACKAGE_NAME);
 338     ZOOM_options_set(zoptions, "implementationVersion", VERSION);
 339
 340     if ((charset = session_setting_oneval(sdb, PZ_NEGOTIATION_CHARSET)))
 341         ZOOM_options_set(zoptions, "charset", charset);
 342     if (memcached && *memcached)
 343         ZOOM_options_set(zoptions, "memcached", memcached);
 344
 345     if (con->zproxy)
 346     {
 347         yaz_log(YLOG_LOG, "proxy=%s", con->zproxy);
 348         ZOOM_options_set(zoptions, "proxy", con->zproxy);
 349     }
 350     if (apdulog && *apdulog)
 351         ZOOM_options_set(zoptions, "apdulog", apdulog);
 352
 353
 354     if ((sru = session_setting_oneval(sdb, PZ_SRU)) && *sru)
 355         ZOOM_options_set(zoptions, "sru", sru);
 356     if ((sru_version = session_setting_oneval(sdb, PZ_SRU_VERSION))
 357         && *sru_version)
 358         ZOOM_options_set(zoptions, "sru_version", sru_version);
 359
 360     if ((auth = session_setting_oneval(sdb, PZ_AUTHENTICATION)))
 361     {
 362         /* allow splitting user and reset with a blank always */
 363         const char *cp1 = strchr(auth, ' ');
 364         if (!cp1 && sru && *sru)
 365             cp1 =  strchr(auth, '/');
 366         if (!cp1)
 367         {
 368             /* Z39.50 user/password style, or no password for SRU */
 369             ZOOM_options_set(zoptions, "user", auth);
 370         }
 371         else
 372         {
 373             /* now consider group as well */
 374             const char *cp2 = strchr(cp1 + 1, ' ');
 375
 376             ZOOM_options_setl(zoptions, "user", auth, cp1 - auth);
 377             if (!cp2)
 378                 ZOOM_options_set(zoptions, "password", cp1 + 1);
 379             else
 380             {
 381                 ZOOM_options_setl(zoptions, "group", cp1 + 1, cp2 - cp1 - 1);
 382                 ZOOM_options_set(zoptions, "password", cp2 + 1);
 383             }
 384         }
 385     }
 386
 387     value = session_setting_oneval(sdb, PZ_AUTHENTICATION_MODE);
 388     if (value && *value)
 389         ZOOM_options_set(zoptions, "authenticationMode", value);
 390
 391     if (!(con->link = ZOOM_connection_create(zoptions)))
 392     {
 393         yaz_log(YLOG_FATAL|YLOG_ERRNO, "Failed to create ZOOM Connection");
 394         ZOOM_options_destroy(zoptions);
 395         return -1;
 396     }
 397
 398     w = wrbuf_alloc();
 399     if (sru && *sru && !strstr(con->url, "://"))
 400         wrbuf_puts(w, "http://");
 401     if (strchr(con->url, '#'))
 402     {
 403         const char *cp = strchr(con->url, '#');
 404         wrbuf_write(w, con->url, cp - con->url);
 405     }
 406     else
 407         wrbuf_puts(w, con->url);
 408
 409     ZOOM_connection_connect(con->link, wrbuf_cstr(w), 0);
 410
 411     con->iochan = iochan_create(-1, connection_handler, 0, "connection_socket");
 412     con->state = Conn_Connecting;
 413     iochan_settimeout(con->iochan, con->operation_timeout);
 414     iochan_setdata(con->iochan, con);
 415     iochan_add(iochan_man, con->iochan);
 416
 417     client_set_state(con->client, Client_Connecting);
 418     ZOOM_options_destroy(zoptions);
 419     wrbuf_destroy(w);
 420     return 0;
 421 }
 422
 423 // Ensure that client has a connection associated
 424 int client_prep_connection(struct client *cl,
 425                            int operation_timeout, int session_timeout,
 426                            iochan_man_t iochan_man,
 427                            const struct timeval *abstime)
 428 {
 429     struct connection *co;
 430     struct session_database *sdb = client_get_database(cl);
 431     const char *zproxy = session_setting_oneval(sdb, PZ_ZPROXY);
 432     const char *url = session_setting_oneval(sdb, PZ_URL);
 433
 434     if (zproxy && zproxy[0] == '\0')
 435         zproxy = 0;
 436
 437     if (!url || !*url)
 438         url = sdb->database->id;
 439
 440     yaz_log(YLOG_DEBUG, "client_prep_connection: target=%s url=%s",
 441             client_get_id(cl), url);
 442
 443     co = client_get_connection(cl);
 444     if (!co)
 445     {
 446         co = connection_create(cl, url, zproxy,
 447                                operation_timeout, session_timeout,
 448                                iochan_man);
 449     }
 450
 451     if (co && co->link)
 452         return 1;
 453     else
 454         return 0;
 455 }
 456
 457 /*
 458  * Local variables:
 459  * c-basic-offset: 4
 460  * c-file-style: "Stroustrup"
 461  * indent-tabs-mode: nil
 462  * End:
 463  * vim: shiftwidth=4 tabstop=8 expandtab
 464  */
 465