SRW/SRU 1.1. Bug fixes. cql2pqf, explain, zeerex.
[yazpp-moved-to-github.git] / src / yaz-proxy.cpp
index d623c36..71dd336 100644 (file)
@@ -2,7 +2,7 @@
  * Copyright (c) 1998-2003, Index Data.
  * See the file LICENSE for details.
  * 
- * $Id: yaz-proxy.cpp,v 1.71 2003-12-16 14:17:01 adam Exp $
+ * $Id: yaz-proxy.cpp,v 1.72 2003-12-20 22:44:30 adam Exp $
  */
 
 #include <assert.h>
@@ -105,7 +105,8 @@ Yaz_Proxy::Yaz_Proxy(IYaz_PDU_Observable *the_PDU_Observable,
     m_initRequest_mem = 0;
     m_apdu_invalid_session = 0;
     m_mem_invalid_session = 0;
-    m_s2z_odr = 0;
+    m_s2z_odr_init = 0;
+    m_s2z_odr_search = 0;
     m_s2z_init_apdu = 0;
     m_s2z_search_apdu = 0;
     m_s2z_present_apdu = 0;
@@ -113,6 +114,7 @@ Yaz_Proxy::Yaz_Proxy(IYaz_PDU_Observable *the_PDU_Observable,
     m_http_version = 0;
     m_soap_ns = 0;
     m_s2z_packing = Z_SRW_recordPacking_string;
+    m_zeerex_fname = 0;
 }
 
 Yaz_Proxy::~Yaz_Proxy()
@@ -125,8 +127,10 @@ Yaz_Proxy::~Yaz_Proxy()
     xfree (m_default_target);
     xfree (m_proxy_authentication);
     xfree (m_optimize);
-    if (m_s2z_odr)
-       odr_destroy(m_s2z_odr);
+    if (m_s2z_odr_init)
+       odr_destroy(m_s2z_odr_init);
+    if (m_s2z_odr_search)
+       odr_destroy(m_s2z_odr_search);
     delete m_config;
 }
 
@@ -310,7 +314,8 @@ Yaz_ProxyClient *Yaz_Proxy::get_client(Z_APDU *apdu, const char *cookie,
                                 &m_keepalive_limit_bw,
                                 &m_keepalive_limit_pdu,
                                 &pre_init,
-                                &cql2rpn_fname);
+                                &cql2rpn_fname,
+                                &m_zeerex_fname);
        }
        if (client_idletime != -1)
        {
@@ -318,10 +323,7 @@ Yaz_ProxyClient *Yaz_Proxy::get_client(Z_APDU *apdu, const char *cookie,
            timeout(m_client_idletime);
        }
        if (cql2rpn_fname)
-       {
-           yaz_log(LOG_LOG, "set_pqf_file %s", cql2rpn_fname);
            m_cql2rpn.set_pqf_file(cql2rpn_fname);
-       }
        if (!url[0])
        {
            yaz_log(LOG_LOG, "%sNo default target", m_session_str);
@@ -639,10 +641,9 @@ int Yaz_Proxy::send_http_response(int code)
     Z_HTTP_Response *hres = gdu->u.HTTP_Response;
     if (m_http_version)
        hres->version = odr_strdup(o, m_http_version);
+    m_http_keepalive = 0;
     int len;
-    int r = send_GDU(gdu, &len);
-    delete this;
-    return r;
+    return send_GDU(gdu, &len);
 }
 
 int Yaz_Proxy::send_srw_response(Z_SRW_PDU *srw_pdu)
@@ -659,7 +660,7 @@ int Yaz_Proxy::send_srw_response(Z_SRW_PDU *srw_pdu)
 
     static Z_SOAP_Handler soap_handlers[2] = {
 #if HAVE_XML2
-       {"http://www.loc.gov/zing/srw/v1.0/", 0,
+       {"http://www.loc.gov/zing/srw/", 0,
         (Z_SOAP_fun) yaz_srw_codec},
 #endif
        {0, 0, 0}
@@ -677,9 +678,7 @@ int Yaz_Proxy::send_srw_response(Z_SRW_PDU *srw_pdu)
                               &hres->content_buf, &hres->content_len,
                               soap_handlers, 0);
     int len;
-    int r = send_GDU(gdu, &len);
-    if (!m_http_keepalive)
-       delete this;
+    return send_GDU(gdu, &len);
 }
 
 int Yaz_Proxy::send_to_srw_client_error(int srw_error)
@@ -711,7 +710,7 @@ int Yaz_Proxy::z_to_srw_diag(ODR o, Z_SRW_searchRetrieveResponse *srw_res,
     return 0;
 }
 
-int Yaz_Proxy::send_to_srw_client_ok(int hits, Z_Records *records)
+int Yaz_Proxy::send_to_srw_client_ok(int hits, Z_Records *records, int start)
 {
     ODR o = odr_encode();
     Z_SRW_PDU *srw_pdu = yaz_srw_get(o, Z_SRW_searchRetrieve_response);
@@ -734,7 +733,7 @@ int Yaz_Proxy::send_to_srw_client_ok(int hits, Z_Records *records)
                srw_res->records[i].recordPacking = m_s2z_packing;
                srw_res->records[i].recordData_buf = "67";
                srw_res->records[i].recordData_len = 2;
-               srw_res->records[i].recordPosition = 0;
+               srw_res->records[i].recordPosition = odr_intdup(o, i+start);
                continue;
            }
            Z_External *r = npr->u.databaseRecord;
@@ -746,7 +745,7 @@ int Yaz_Proxy::send_to_srw_client_ok(int hits, Z_Records *records)
                srw_res->records[i].recordData_buf = (char*) 
                    r->u.octet_aligned->buf;
                srw_res->records[i].recordData_len = r->u.octet_aligned->len;
-               srw_res->records[i].recordPosition = 0;
+               srw_res->records[i].recordPosition = odr_intdup(o, i+start);
            }
            else
            {
@@ -754,7 +753,7 @@ int Yaz_Proxy::send_to_srw_client_ok(int hits, Z_Records *records)
                srw_res->records[i].recordPacking = m_s2z_packing;
                srw_res->records[i].recordData_buf = "67";
                srw_res->records[i].recordData_len = 2;
-               srw_res->records[i].recordPosition = 0;
+               srw_res->records[i].recordPosition = odr_intdup(o, i+start);
            }
        }
     }
@@ -769,45 +768,88 @@ int Yaz_Proxy::send_to_srw_client_ok(int hits, Z_Records *records)
     return send_srw_response(srw_pdu);
     
 }
-int Yaz_Proxy::send_PDU_convert(Z_APDU *apdu, int *len)
+
+int Yaz_Proxy::send_srw_explain()
 {
-    if (m_s2z_init_apdu && apdu->which == Z_APDU_initResponse)
+    Z_SRW_PDU *res = yaz_srw_get(odr_encode(), Z_SRW_explain_response);
+    Z_SRW_explainResponse *er = res->u.explain_response;
+    
+    if (m_zeerex_fname)
     {
-       m_s2z_init_apdu = 0;
-       Z_InitResponse *res = apdu->u.initResponse;
-       if (*res->result == 0)
+       FILE *inf = fopen(m_zeerex_fname, "rb");
+       if (inf)
        {
-           send_to_srw_client_error(3);
+           fseek(inf, 0L, SEEK_END);
+           long sz = ftell(inf);
+           fseek(inf, 0L, SEEK_SET);
+           if (sz > 0)
+           {
+               er->record.recordData_buf = 
+                   (char*) odr_malloc(odr_encode(), sz);
+               size_t s = fread(er->record.recordData_buf, 1,sz, inf);
+               if (s > 0)
+                   er->record.recordData_len = s;
+           }
+           else
+               yaz_log(LOG_WARN|LOG_ERRNO, "zeerex file: ftell");
+           fclose(inf);
        }
        else
-       {
-           handle_incoming_Z_PDU(m_s2z_search_apdu);
-       }
+           yaz_log(LOG_WARN|LOG_ERRNO, "zeerex file: fopen");
     }
-    else if (m_s2z_search_apdu && apdu->which == Z_APDU_searchResponse)
+    else
+       yaz_log(LOG_LOG, "zeerex file: not defined");
+    return send_srw_response(res);
+}
+
+int Yaz_Proxy::send_PDU_convert(Z_APDU *apdu, int *len)
+{
+    if (m_http_version)
     {
-       m_s2z_search_apdu = 0;
-       Z_SearchResponse *res = apdu->u.searchResponse;
-       m_s2z_hit_count = *res->resultCount;
-       if (res->records && res->records->which == Z_Records_NSD)
+       if (apdu->which == Z_APDU_initResponse)
        {
-           send_to_srw_client_ok(0, res->records);
+           Z_InitResponse *res = apdu->u.initResponse;
+           if (*res->result == 0)
+           {
+               send_to_srw_client_error(3);
+           }
+           else if (!m_s2z_search_apdu)
+           {
+               send_srw_explain();
+           }
+           else
+           {
+               handle_incoming_Z_PDU(m_s2z_search_apdu);
+           }
        }
-       else if (m_s2z_present_apdu)
+       else if (m_s2z_search_apdu && apdu->which == Z_APDU_searchResponse)
        {
-           handle_incoming_Z_PDU(m_s2z_present_apdu);
+           m_s2z_search_apdu = 0;
+           Z_SearchResponse *res = apdu->u.searchResponse;
+           m_s2z_hit_count = *res->resultCount;
+           if (res->records && res->records->which == Z_Records_NSD)
+           {
+               send_to_srw_client_ok(0, res->records, 1);
+           }
+           else if (m_s2z_present_apdu)
+           {
+               handle_incoming_Z_PDU(m_s2z_present_apdu);
+           }
+           else
+           {
+               send_to_srw_client_ok(m_s2z_hit_count, res->records, 1);
+           }
        }
-       else
+       else if (m_s2z_present_apdu && apdu->which == Z_APDU_presentResponse)
        {
-           send_to_srw_client_ok(m_s2z_hit_count, res->records);
+           int start = 
+               *m_s2z_present_apdu->u.presentRequest->resultSetStartPoint;
+
+           m_s2z_present_apdu = 0;
+           Z_PresentResponse *res = apdu->u.presentResponse;
+           send_to_srw_client_ok(m_s2z_hit_count, res->records, start);
        }
     }
-    else if (m_s2z_present_apdu && apdu->which == Z_APDU_presentResponse)
-    {
-       m_s2z_present_apdu = 0;
-       Z_PresentResponse *res = apdu->u.presentResponse;
-       send_to_srw_client_ok(m_s2z_hit_count, res->records);
-    }
     else
        return send_Z_PDU(apdu, len);
     return 0;
@@ -881,6 +923,18 @@ int Yaz_Proxy::send_to_client(Z_APDU *apdu)
        m_client = 0;
        m_parent->pre_init();
     }
+    if (m_http_version)
+    {
+       if (!m_http_keepalive)
+       {
+#if 1
+           timeout(1);
+#else
+           shutdown();
+           return -1;
+#endif
+       }
+    }
     return r;
 }
 
@@ -1146,8 +1200,6 @@ void Yaz_Proxy::recv_GDU(Z_GDU *apdu, int len)
     int bw_total = m_bw_stat.get_total();
     int pdu_total = m_pdu_stat.get_total();
 
-    yaz_log(LOG_LOG, "%sstat bw=%d pdu=%d limit-bw=%d limit-pdu=%d",
-           m_session_str, bw_total, pdu_total, m_bw_max, m_pdu_max);
     int reduce = 0;
     if (m_bw_max)
     {
@@ -1166,7 +1218,10 @@ void Yaz_Proxy::recv_GDU(Z_GDU *apdu, int len)
     }
     if (reduce)  
     {
-       yaz_log(LOG_LOG, "%sLimit delay=%d", m_session_str, reduce);
+       yaz_log(LOG_LOG, "%sdelay=%d bw=%d pdu=%d limit-bw=%d limit-pdu=%d",
+               m_session_str, reduce, bw_total, pdu_total,
+               m_bw_max, m_pdu_max);
+       
        m_bw_hold_PDU = apdu;  // save PDU and signal "on hold"
        timeout(reduce);       // call us reduce seconds later
     }
@@ -1343,221 +1398,19 @@ Z_APDU *Yaz_Proxy::handle_syntax_validation(Z_APDU *apdu)
     return apdu;
 }
 
-static int hex_digit (int ch)
-{
-    if (ch >= '0' && ch <= '9')
-        return ch - '0';
-    else if (ch >= 'a' && ch <= 'f')
-        return ch - 'a'+10;
-    else if (ch >= 'A' && ch <= 'F')
-        return ch - 'A'+10;
-    return 0;
-}
-
-static char *uri_val(const char *path, const char *name, ODR o)
-{
-    size_t nlen = strlen(name);
-    if (*path != '?')
-        return 0;
-    path++;
-    while (path && *path)
-    {
-        const char *p1 = strchr(path, '=');
-        if (!p1)
-            break;
-        if ((size_t)(p1 - path) == nlen && !memcmp(path, name, nlen))
-        {
-            size_t i = 0;
-            char *ret;
-            
-            path = p1 + 1;
-            p1 = strchr(path, '&');
-            if (!p1)
-                p1 = strlen(path) + path;
-            ret = (char*) odr_malloc(o, p1 - path + 1);
-            while (*path && *path != '&')
-            {
-                if (*path == '+')
-                {
-                    ret[i++] = ' ';
-                    path++;
-                }
-                else if (*path == '%' && path[1] && path[2])
-                {
-                    ret[i++] = hex_digit (path[1])*16 + hex_digit (path[2]);
-                    path = path + 3;
-                }
-                else
-                    ret[i++] = *path++;
-            }
-            ret[i] = '\0';
-            return ret;
-        }
-        path = strchr(p1, '&');
-        if (path)
-            path++;
-    }
-    return 0;
-}
-
-void uri_val_int(const char *path, const char *name, ODR o, int **intp)
-{
-    const char *v = uri_val(path, name, o);
-    if (v)
-        *intp = odr_intdup(o, atoi(v));
-}
-
-int yaz_check_for_sru(Z_HTTP_Request *hreq, Z_SRW_PDU **srw_pdu,
-                     char **soap_ns, ODR decode)
-{
-    if (!strcmp(hreq->method, "GET"))
-    {
-        char *db = "Default";
-        const char *p0 = hreq->path, *p1;
-#if HAVE_XML2
-        int ret = -1;
-        char *charset = 0;
-        Z_SOAP *soap_package = 0;
-        static Z_SOAP_Handler soap_handlers[2] = {
-            {"http://www.loc.gov/zing/srw/v1.0/", 0,
-             (Z_SOAP_fun) yaz_srw_codec},
-            {0, 0, 0}
-        };
-#endif
-        
-        if (*p0 == '/')
-            p0++;
-        p1 = strchr(p0, '?');
-        if (!p1)
-            p1 = p0 + strlen(p0);
-        if (p1 != p0)
-        {
-            db = (char*) odr_malloc(decode, p1 - p0 + 1);
-            memcpy (db, p0, p1 - p0);
-            db[p1 - p0] = '\0';
-        }
-#if HAVE_XML2
-        if (p1 && *p1 == '?' && p1[1])
-        {
-            Z_SRW_PDU *sr = yaz_srw_get(decode, Z_SRW_searchRetrieve_request);
-            char *query = uri_val(p1, "query", decode);
-            char *pQuery = uri_val(p1, "pQuery", decode);
-            char *sortKeys = uri_val(p1, "sortKeys", decode);
-            
-           *srw_pdu = sr;
-            if (query)
-            {
-                sr->u.request->query_type = Z_SRW_query_type_cql;
-                sr->u.request->query.cql = query;
-            }
-            if (pQuery)
-            {
-                sr->u.request->query_type = Z_SRW_query_type_pqf;
-                sr->u.request->query.pqf = pQuery;
-            }
-            if (sortKeys)
-            {
-                sr->u.request->sort_type = Z_SRW_sort_type_sort;
-                sr->u.request->sort.sortKeys = sortKeys;
-            }
-            sr->u.request->recordSchema = uri_val(p1, "recordSchema", decode);
-            sr->u.request->recordPacking = uri_val(p1, "recordPacking", decode);
-            if (!sr->u.request->recordPacking)
-                sr->u.request->recordPacking = "xml";
-            uri_val_int(p1, "maximumRecords", decode, 
-                        &sr->u.request->maximumRecords);
-            uri_val_int(p1, "startRecord", decode,
-                        &sr->u.request->startRecord);
-            if (sr->u.request->startRecord)
-                yaz_log(LOG_LOG, "startRecord=%d", *sr->u.request->startRecord);
-            sr->u.request->database = db;
-           *soap_ns = "SRU";
-           return 0;
-        }
-#endif
-       return 1;
-    }
-    return 2;
-}
-
-int yaz_check_for_srw(Z_HTTP_Request *hreq, Z_SRW_PDU **srw_pdu,
-                     char **soap_ns, ODR decode)
-{
-    if (!strcmp(hreq->method, "POST"))
-    {
-       const char *content_type = z_HTTP_header_lookup(hreq->headers,
-                                                       "Content-Type");
-       if (content_type && !yaz_strcmp_del("text/xml", content_type, "; "))
-       {
-           char *db = "Default";
-           const char *p0 = hreq->path, *p1;
-           Z_SOAP *soap_package = 0;
-            int ret = -1;
-            int http_code = 500;
-            const char *charset_p = 0;
-            char *charset = 0;
-           
-            static Z_SOAP_Handler soap_handlers[2] = {
-#if HAVE_XML2
-                {"http://www.loc.gov/zing/srw/v1.0/", 0,
-                 (Z_SOAP_fun) yaz_srw_codec},
-#endif
-                {0, 0, 0}
-            };
-           
-           if (*p0 == '/')
-               p0++;
-           p1 = strchr(p0, '?');
-           if (!p1)
-               p1 = p0 + strlen(p0);
-           if (p1 != p0)
-           {
-               db = (char*) odr_malloc(decode, p1 - p0 + 1);
-               memcpy (db, p0, p1 - p0);
-               db[p1 - p0] = '\0';
-           }
-
-            if ((charset_p = strstr(content_type, "; charset=")))
-            {
-                int i = 0;
-                charset_p += 10;
-                while (i < 20 && charset_p[i] &&
-                       !strchr("; \n\r", charset_p[i]))
-                    i++;
-                charset = (char*) odr_malloc(decode, i+1);
-                memcpy(charset, charset_p, i);
-                charset[i] = '\0';
-                yaz_log(LOG_LOG, "SOAP encoding %s", charset);
-            }
-            ret = z_soap_codec(decode, &soap_package, 
-                               &hreq->content_buf, &hreq->content_len,
-                               soap_handlers);
-           if (!ret && soap_package->which == Z_SOAP_generic &&
-               soap_package->u.generic->no == 0)
-           {
-               *srw_pdu = (Z_SRW_PDU*) soap_package->u.generic->p;
-               
-               if ((*srw_pdu)->which == Z_SRW_searchRetrieve_request &&
-                   (*srw_pdu)->u.request->database == 0)
-                   (*srw_pdu)->u.request->database = db;
-
-               *soap_ns = odr_strdup(decode, soap_package->ns);
-               return 0;
-           }
-           return 1;
-       }
-    }
-    return 2;
-}
-
 void Yaz_Proxy::handle_incoming_HTTP(Z_HTTP_Request *hreq)
 {
     Z_SRW_PDU *srw_pdu = 0;
     char *soap_ns = 0;
-    if (m_s2z_odr)
+    if (m_s2z_odr_init)
+    {
+       odr_destroy(m_s2z_odr_init);
+       m_s2z_odr_init = 0;
+    }
+    if (m_s2z_odr_search)
     {
-       odr_destroy(m_s2z_odr);
-       m_s2z_odr = 0;
+       odr_destroy(m_s2z_odr_search);
+       m_s2z_odr_search = 0;
     }
 
     m_http_keepalive = 0;
@@ -1584,8 +1437,9 @@ void Yaz_Proxy::handle_incoming_HTTP(Z_HTTP_Request *hreq)
     if (yaz_check_for_srw(hreq, &srw_pdu, &soap_ns, odr_decode()) == 0
        || yaz_check_for_sru(hreq, &srw_pdu, &soap_ns, odr_decode()) == 0)
     {
-       m_s2z_odr = odr_createmem(ODR_ENCODE);
-       m_soap_ns = odr_strdup(m_s2z_odr, soap_ns);
+       m_s2z_odr_init = odr_createmem(ODR_ENCODE);
+       m_s2z_odr_search = odr_createmem(ODR_ENCODE);
+       m_soap_ns = odr_strdup(m_s2z_odr_search, soap_ns);
        m_s2z_init_apdu = 0;
        m_s2z_search_apdu = 0;
        m_s2z_present_apdu = 0;
@@ -1601,27 +1455,28 @@ void Yaz_Proxy::handle_incoming_HTTP(Z_HTTP_Request *hreq)
                m_s2z_packing = Z_SRW_recordPacking_string;
 
            // prepare search PDU
-           m_s2z_search_apdu = zget_APDU(m_s2z_odr, Z_APDU_searchRequest);
+           m_s2z_search_apdu = zget_APDU(m_s2z_odr_search,
+                                         Z_APDU_searchRequest);
            Z_SearchRequest *z_searchRequest =
                m_s2z_search_apdu->u.searchRequest;
 
            z_searchRequest->num_databaseNames = 1;
            z_searchRequest->databaseNames = (char**)
-               odr_malloc(m_s2z_odr, sizeof(char *));
-           z_searchRequest->databaseNames[0] = odr_strdup(m_s2z_odr,
+               odr_malloc(m_s2z_odr_search, sizeof(char *));
+           z_searchRequest->databaseNames[0] = odr_strdup(m_s2z_odr_search,
                                                           srw_req->database);
            
            // query transformation
            Z_Query *query = (Z_Query *)
-               odr_malloc(odr_encode(), sizeof(Z_Query));
+               odr_malloc(m_s2z_odr_search, sizeof(Z_Query));
            z_searchRequest->query = query;
            
            if (srw_req->query_type == Z_SRW_query_type_cql)
            {
                Z_External *ext = (Z_External *) 
-                   odr_malloc(m_s2z_odr, sizeof(*ext));
+                   odr_malloc(m_s2z_odr_search, sizeof(*ext));
                ext->direct_reference = 
-                   odr_getoidbystr(m_s2z_odr, "1.2.840.10003.16.2");
+                   odr_getoidbystr(m_s2z_odr_search, "1.2.840.10003.16.2");
                ext->indirect_reference = 0;
                ext->descriptor = 0;
                ext->which = Z_External_CQL;
@@ -1637,7 +1492,7 @@ void Yaz_Proxy::handle_incoming_HTTP(Z_HTTP_Request *hreq)
                
                pqf_parser = yaz_pqf_create ();
                
-               RPNquery = yaz_pqf_parse (pqf_parser, m_s2z_odr,
+               RPNquery = yaz_pqf_parse (pqf_parser, m_s2z_odr_search,
                                          srw_req->query.pqf);
                if (!RPNquery)
                {
@@ -1677,25 +1532,31 @@ void Yaz_Proxy::handle_incoming_HTTP(Z_HTTP_Request *hreq)
                    *z_searchRequest->mediumSetPresentNumber = max;
                    *z_searchRequest->largeSetLowerBound = 2000000000; // 2e9
                    z_searchRequest->preferredRecordSyntax =
-                       yaz_oidval_to_z3950oid(m_s2z_odr, CLASS_RECSYN,
+                       yaz_oidval_to_z3950oid(m_s2z_odr_search, CLASS_RECSYN,
                                               VAL_TEXT_XML);
                }
                else   // Z39.50 present
                {
-                   m_s2z_present_apdu = zget_APDU(m_s2z_odr, 
+                   m_s2z_present_apdu = zget_APDU(m_s2z_odr_search, 
                                                   Z_APDU_presentRequest);
                    Z_PresentRequest *z_presentRequest = 
                        m_s2z_present_apdu->u.presentRequest;
                    *z_presentRequest->resultSetStartPoint = start;
                    *z_presentRequest->numberOfRecordsRequested = max;
                    z_presentRequest->preferredRecordSyntax =
-                       yaz_oidval_to_z3950oid(m_s2z_odr, CLASS_RECSYN,
+                       yaz_oidval_to_z3950oid(m_s2z_odr_search, CLASS_RECSYN,
                                               VAL_TEXT_XML);
                }
            }
            if (!m_client)
            {
-               m_s2z_init_apdu = zget_APDU(m_s2z_odr, Z_APDU_initRequest);
+               yaz_log(LOG_LOG, "handle_incoming: initRequest");
+               m_s2z_init_apdu = zget_APDU(m_s2z_odr_init,
+                                           Z_APDU_initRequest);
+               
+               // prevent m_initRequest_apdu memory from being grabbed
+               // in Yaz_Proxy::handle_incoming_Z_PDU
+               m_initRequest_apdu = m_s2z_init_apdu;
                handle_incoming_Z_PDU(m_s2z_init_apdu);
                return;
            }
@@ -1705,6 +1566,23 @@ void Yaz_Proxy::handle_incoming_HTTP(Z_HTTP_Request *hreq)
                return;
            }
        }
+       else if (srw_pdu->which == Z_SRW_explain_request)
+       {
+           if (!m_client)
+           {
+               yaz_log(LOG_LOG, "handle_incoming: initRequest");
+               m_s2z_init_apdu = zget_APDU(m_s2z_odr_init,
+                                           Z_APDU_initRequest);
+               
+               // prevent m_initRequest_apdu memory from being grabbed
+               // in Yaz_Proxy::handle_incoming_Z_PDU
+               m_initRequest_apdu = m_s2z_init_apdu;
+               handle_incoming_Z_PDU(m_s2z_init_apdu);
+           }
+           else
+               send_srw_explain();
+           return;
+       }
     }
     int len = 0;
     Z_GDU *p = z_get_HTTP_Response(odr_encode(), 400);
@@ -1754,12 +1632,14 @@ void Yaz_Proxy::handle_incoming_Z_PDU(Z_APDU *apdu)
        {
            if (handle_init_response_for_invalid_session(apdu))
                return;
-           Z_APDU *apdu = m_client->m_initResponse;
-           apdu->u.initResponse->otherInfo = 0;
+           Z_APDU *apdu2 = m_client->m_initResponse;
+           apdu2->u.initResponse->otherInfo = 0;
            if (m_client->m_cookie && *m_client->m_cookie)
-               set_otherInformationString(apdu, VAL_COOKIE, 1,
+               set_otherInformationString(apdu2, VAL_COOKIE, 1,
                                           m_client->m_cookie);
-           send_to_client(apdu);
+           apdu2->u.initResponse->referenceId =
+               apdu->u.initRequest->referenceId;
+           send_to_client(apdu2);
            return;
        }
        m_client->m_init_flag = 1;
@@ -1956,6 +1836,7 @@ void Yaz_Proxy::pre_init()
     int keepalive_limit_bw, keepalive_limit_pdu;
     int pre_init;
     const char *cql2rpn = 0;
+    const char *zeerex = 0;
 
     Yaz_ProxyConfig *cfg = check_reconfigure();
 
@@ -1973,7 +1854,8 @@ void Yaz_Proxy::pre_init()
                                          &keepalive_limit_bw,
                                          &keepalive_limit_pdu,
                                          &pre_init,
-                                         &cql2rpn) ; i++)
+                                         &cql2rpn,
+                                         &zeerex) ; i++)
     {
        if (pre_init)
        {