src/snmp/Inquirer.cc

   1 /*
   2  * Copyright (C) 1996-2018 The Squid Software Foundation and contributors
   3  *
   4  * Squid software is distributed under GPLv2+ license and includes
   5  * contributions from numerous individuals and organizations.
   6  * Please see the COPYING and CONTRIBUTORS files for details.
   7  */
   8
   9 /* DEBUG: section 49    SNMP Interface */
  10
  11 #include "squid.h"
  12 #include "base/TextException.h"
  13 #include "comm.h"
  14 #include "comm/Connection.h"
  15 #include "CommCalls.h"
  16 #include "ipc/UdsOp.h"
  17 #include "snmp/Inquirer.h"
  18 #include "snmp/Request.h"
  19 #include "snmp/Response.h"
  20 #include "snmp_core.h"
  21
  22 CBDATA_NAMESPACED_CLASS_INIT(Snmp, Inquirer);
  23
  24 Snmp::Inquirer::Inquirer(const Request& aRequest, const Ipc::StrandCoords& coords):
  25     Ipc::Inquirer(aRequest.clone(), coords, 2),
  26     aggrPdu(aRequest.pdu)
  27 {
  28     conn = new Comm::Connection;
  29     conn->fd = aRequest.fd;
  30     ImportFdIntoComm(conn, SOCK_DGRAM, IPPROTO_UDP, Ipc::fdnInSnmpSocket);
  31
  32     debugs(49, 5, HERE);
  33     closer = asyncCall(49, 5, "Snmp::Inquirer::noteCommClosed",
  34                        CommCbMemFunT<Inquirer, CommCloseCbParams>(this, &Inquirer::noteCommClosed));
  35     comm_add_close_handler(conn->fd, closer);
  36
  37     // forget client FD to avoid sending it to strands that may forget to close
  38     if (Request *snmpRequest = dynamic_cast<Request*>(request.getRaw()))
  39         snmpRequest->fd = -1;
  40 }
  41
  42 /// closes our copy of the client connection socket
  43 void
  44 Snmp::Inquirer::cleanup()
  45 {
  46     if (Comm::IsConnOpen(conn)) {
  47         if (closer != NULL) {
  48             comm_remove_close_handler(conn->fd, closer);
  49             closer = NULL;
  50         }
  51         conn->close();
  52     }
  53     conn = NULL;
  54 }
  55
  56 void
  57 Snmp::Inquirer::start()
  58 {
  59     debugs(49, 5, HERE);
  60     Ipc::Inquirer::start();
  61     Must(Comm::IsConnOpen(conn));
  62     inquire();
  63 }
  64
  65 void
  66 Snmp::Inquirer::handleException(const std::exception& e)
  67 {
  68     aggrPdu.errstat = SNMP_ERR_GENERR;
  69     Ipc::Inquirer::handleException(e);
  70 }
  71
  72 bool
  73 Snmp::Inquirer::aggregate(Response::Pointer aResponse)
  74 {
  75     Snmp::Response& response = static_cast<Snmp::Response&>(*aResponse);
  76     bool error = response.pdu.errstat != SNMP_ERR_NOERROR;
  77     if (error) {
  78         aggrPdu = response.pdu;
  79     } else {
  80         aggrPdu.aggregate(response.pdu);
  81     }
  82     return !error;
  83 }
  84
  85 /// called when the some external force closed our socket
  86 void
  87 Snmp::Inquirer::noteCommClosed(const CommCloseCbParams& params)
  88 {
  89     debugs(49, 5, HERE);
  90     Must(!Comm::IsConnOpen(conn) || conn->fd == params.conn->fd);
  91     conn = NULL;
  92     mustStop("commClosed");
  93 }
  94
  95 bool
  96 Snmp::Inquirer::doneAll() const
  97 {
  98     return !writer && Ipc::Inquirer::doneAll();
  99 }
 100
 101 void
 102 Snmp::Inquirer::sendResponse()
 103 {
 104     debugs(49, 5, HERE);
 105     aggrPdu.fixAggregate();
 106     aggrPdu.command = SNMP_PDU_RESPONSE;
 107     u_char buffer[SNMP_REQUEST_SIZE];
 108     int len = sizeof(buffer);
 109     Snmp::Request& req = static_cast<Snmp::Request&>(*request);
 110     snmp_build(&req.session, &aggrPdu, buffer, &len);
 111     comm_udp_sendto(conn->fd, req.address, buffer, len);
 112 }
 113