src/server/plugins/postgresql/service.c

/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 *
 * Copyright 2022 Olaf Wintermann. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *   1. Redistributions of source code must retain the above copyright
 *      notice, this list of conditions and the following disclaimer.
 *
 *   2. Redistributions in binary form must reproduce the above copyright
 *      notice, this list of conditions and the following disclaimer in the
 *      documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include "service.h"

#include <stdio.h>
#include <string.h>

#include "resource.h"

int pg_query(pblock *pb, Session *sn, Request *rq) {
    char *respool = pblock_findval("resource", pb);
    char *query = pblock_findval("query", pb);
    
    if(!respool) {
        log_ereport(LOG_MISCONFIG, "pg-query: missing resource parameter");
        return REQ_ABORTED;
    }
    if(!query) {
        log_ereport(LOG_MISCONFIG, "pg-query: missing query parameter");
        return REQ_ABORTED;
    }
    
    // Get the named resource and check if the PG connection works
    ResourceData *res = resourcepool_lookup(sn, rq, respool, 0);
    if(!res) {
        log_ereport(LOG_FAILURE, "pg-query: cannot get resource '%s'", respool);
        return REQ_ABORTED;
    }
    
    PGconn *connection = res->data;
    if(pg_check_connection(LOG_FAILURE, respool, connection)) {
        return REQ_ABORTED;
    }
    
    // execute query
    PGresult *result = PQexec(connection, query);
    if(!result) return REQ_ABORTED;
    
    // start response
    pblock_remove("content-type", rq->srvhdrs);
    pblock_nvinsert("content-type", "text/html", rq->srvhdrs);
    
    protocol_status(sn, rq, 200, NULL);
    http_start_response(sn, rq);
    
    // (html) header
    net_printf(sn->csd, "%s", "<!DOCTYPE html>\n<html><head></head><body>\n");
    
    int nfields = PQnfields(result);
    if(nfields > 0) {
        net_printf(sn->csd, "<table>\n<tr>\n");
        for(int i=0;i<nfields;i++) {
            char *fieldName = PQfname(result, i);
            char *fieldNameEscaped = util_html_escape(fieldName);
            if(fieldNameEscaped) {
                net_printf(sn->csd, "<th>%s</th>\n", fieldNameEscaped);
                FREE(fieldNameEscaped);
            }
        }
        net_printf(sn->csd, "</tr>\n");
        
        int nrows = PQntuples(result);
        for(int r=0;r<nrows;r++) {
            net_printf(sn->csd, "<tr>\n");
            for(int c=0;c<nfields;c++) {
                char *fieldValue = PQgetvalue(result, r, c);
                char *fieldValueEscaped = util_html_escape(fieldValue);
                if(fieldValueEscaped) {
                    net_printf(sn->csd, "<td>%s</td>\n", fieldValueEscaped);
                    FREE(fieldValueEscaped);
                }
            }
            net_printf(sn->csd, "</tr>\n");
        }
        
        
        net_printf(sn->csd, "</table>\n");
    } else {
        net_printf(sn->csd, "<p>%s</p>\n", PQresStatus(PQresultStatus(result)));
    }
    
    net_printf(sn->csd, "%s", "</body></html>\n");
    
    PQclear(result);
    
    return REQ_PROCEED;
}