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