/*
    Posadis - A DNS Server
    SQL-based dns server
    Copyright (C) 2002  Meilof Veeningen <meilof@users.sourceforge.net>

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

#define POS_DEFAULTLOG
#define POS_DEFAULTLOG_STDOUT
#define POS_DEFAULTLOG_SYSLOG

#include <unistd.h>
#include <stdlib.h>
#include <signal.h>
#include <pthread.h>
#include <sys/types.h>
#include <dirent.h>
#include <errno.h>
#include <dbconn.h>

#include <poslib/server/server.h>

void cleanup(int sig) {
  pos_setquitflag();
}

_addr them;
dbconn driver(dbconn::MYSQL);

DnsMessage *my_handle_query(pending_query *query);

int main(int argc, char **argv) {
  _addr we;
  handle_query = my_handle_query;

  try {
    /* get command-line arguments */
    if (argc == 2 && argv[1][0] == '@') {
      txt_to_addr(&we, argv[1] + 1);
    } else if (argc == 1) {
      txt_to_addr(&we, "0.0.0.0");
    } else {
      printf("Usage: sqldns [@interface]\n");
      return 1;
    }

    /* at first, connect to the sql database */
    if (!driver.connect("localhost", "possql", "possql", "possql")) throw PException(true, "Could not connect to database: %s", driver.errorMsg());

    /* bring up posadis */
    servers.push_front(ServerSocket(ss_udp, udpcreateserver(&we)));
    servers.push_front(ServerSocket(ss_tcp, tcpcreateserver(&we)));

    pos_log(context_none, log_info, "Posadis sqldns starting up...");

    signal(SIGINT, cleanup);
    signal(SIGTERM, cleanup);

    posserver_run();
    driver.disconnect();
  } catch (PException p) {
    printf("Fatal exception: %s\n", p.message);
    return 1;
  }

  return 0;
}

domainname lookup_zone(domainname dname) {
  int x = dname.nlabels();
  domainname dom;

  for (int t = 0; t < x; t++) {
    dom = dname.from(t);

    char sqlquery[1024];
    sprintf(sqlquery, "SELECT ttl, domain, ns, mailbox, snum, refresh, retry, expire, nttl FROM zones WHERE domain = \"%s\";", dom.tocstr());

    if (!driver.execute(sqlquery)) {
      pos_log(context_server, log_error, "Could not execute SQL query: %s", driver.errorMsg());
      throw PException("Could not execute query");
    }

    if (!driver.eof) return dom;
  }
  throw PException("No zone found");
}

/* the entry function which will handle all queries */

DnsMessage *my_handle_query(pending_query *query) {
  DnsQuestion q;
  DnsMessage *a = new DnsMessage();
  domainname zone;
  a->ID = query->message->ID;
  bool done = false;

  if (query->message->OPCODE != OPCODE_QUERY) {
    a->RCODE = RCODE_NOTIMP;
    return a;
  }

  if (query->message->questions.begin() == query->message->questions.end()) {
    a->RCODE = RCODE_QUERYERR;
    return a;
  }
  q = *query->message->questions.begin();
    
  try {
    zone = lookup_zone(q.QNAME);
  } catch (PException p) {
    /* we should do root hints or something */
    a->RCODE = RCODE_SRVFAIL;
    return a;
  }
  
  a->AA = true;
  
  if (q.QNAME == zone && (q.QTYPE == DNS_TYPE_SOA || q.QTYPE == QTYPE_ANY)) {
    /* add the zone information */
    string rrdata;
    domainname dom;
    DnsRR rr;
    dom = domainname(driver.getFieldByColumn(2)->asString());
    rrdata.append(dom.c_str(), dom.len());
    dom = domainname(driver.getFieldByColumn(3)->asString());
    rrdata.append(dom.c_str(), dom.len());
    rrdata.append(uint32_buff((u_int32)driver.getFieldByColumn(4)->asInteger()), 4);
    rrdata.append(uint32_buff((u_int32)driver.getFieldByColumn(5)->asInteger()), 4);
    rrdata.append(uint32_buff((u_int32)driver.getFieldByColumn(6)->asInteger()), 4);
    rrdata.append(uint32_buff((u_int32)driver.getFieldByColumn(7)->asInteger()), 4);
    rrdata.append(uint32_buff((u_int32)driver.getFieldByColumn(8)->asInteger()), 4);
  
    rr = DnsRR(q.QNAME, DNS_TYPE_SOA, CLASS_IN, (u_int32)driver.getFieldByColumn(0)->asInteger());
    rr.RDLENGTH = rrdata.size();
    rr.RDATA = (char *)memdup((void *)rrdata.c_str(), rr.RDLENGTH);
    a->answers.push_front(rr);  
    done = true;
  }
    
  /* now query for rrs */

  char sqlquery[1024];
  sprintf(sqlquery, "SELECT domain, ttl, type, data FROM rrs WHERE domain = \"%s\";", q.QNAME.tocstr());

  if (!driver.execute(sqlquery)) {
    pos_log(context_server, log_error, "Could not execute SQL query: %s", driver.errorMsg());
    a->RCODE = RCODE_SRVFAIL;
    return a;
  }
  if (driver.eof) {
    /* apparently, not a domain */
    if (!done) a->RCODE = RCODE_NXDOMAIN;
    return a;
  } else {
    domainname dom;
    u_int32 ttl;
    char *type;
    char *data;
    char *querytype = rrtype_getinfo(q.QTYPE)->name;
    if (querytype == NULL) querytype = "";
    int rrtype;
    DnsRR rr;
    /* enumerate through data */
    while (!driver.eof) {
      dom = domainname(driver.getFieldByColumn(0)->asString());
      ttl = (u_int32)driver.getFieldByColumn(1)->asInteger();
      type = driver.getFieldByColumn(2)->asString();
      data = driver.getFieldByColumn(3)->asString();

      if (rrtype_getinfo(type)) rrtype = rrtype_getinfo(type)->type; else rrtype = 0;

      if (q.QTYPE == QTYPE_ALL || (strcmpi(type, querytype) == 0) && rrtype) {
        /* this is what we need! */
        try {
          string str = rr_fromstring(rrtype_getinfo(type)->type, data);
          rr = DnsRR(q.QNAME, rrtype, CLASS_IN, ttl);
          rr.RDLENGTH = str.size();
          rr.RDATA = (char *)memdup((void *)str.c_str(), rr.RDLENGTH);
          a->answers.push_front(rr);
        } catch (PException p) {
          pos_log(context_server, log_error, "Could not convert RR: %s", p.message);
          a->RCODE = RCODE_SRVFAIL;
          return a;
        }

      }
      driver.next();
    }
  }
  return a;
}