src/snmp/Forwarder.cc

   1 /*
   2  * Copyright (C) 1996-2015 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 "CommCalls.h"
  15 #include "globals.h"
  16 #include "ipc/Port.h"
  17 #include "snmp/Forwarder.h"
  18 #include "snmp/Request.h"
  19 #include "snmp/Response.h"
  20 #include "snmp_core.h"
  21
  22 CBDATA_NAMESPACED_CLASS_INIT(Snmp, Forwarder);
  23
  24 Snmp::Forwarder::Forwarder(const Pdu& aPdu, const Session& aSession, int aFd,
  25                            const Ip::Address& anAddress):
  26     Ipc::Forwarder(new Request(KidIdentifier, 0, aPdu, aSession, aFd, anAddress), 2),
  27     fd(aFd)
  28 {
  29     debugs(49, 5, HERE << "FD " << aFd);
  30     Must(fd >= 0);
  31     closer = asyncCall(49, 5, "Snmp::Forwarder::noteCommClosed",
  32                        CommCbMemFunT<Forwarder, CommCloseCbParams>(this, &Forwarder::noteCommClosed));
  33     comm_add_close_handler(fd, closer);
  34 }
  35
  36 /// removes our cleanup handler of the client connection socket
  37 void
  38 Snmp::Forwarder::cleanup()
  39 {
  40     if (fd >= 0) {
  41         if (closer != NULL) {
  42             comm_remove_close_handler(fd, closer);
  43             closer = NULL;
  44         }
  45         fd = -1;
  46     }
  47 }
  48
  49 /// called when the client socket gets closed by some external force
  50 void
  51 Snmp::Forwarder::noteCommClosed(const CommCloseCbParams& params)
  52 {
  53     debugs(49, 5, HERE);
  54     Must(fd == params.fd);
  55     fd = -1;
  56     mustStop("commClosed");
  57 }
  58
  59 void
  60 Snmp::Forwarder::handleTimeout()
  61 {
  62     sendError(SNMP_ERR_RESOURCEUNAVAILABLE);
  63     Ipc::Forwarder::handleTimeout();
  64 }
  65
  66 void
  67 Snmp::Forwarder::handleException(const std::exception& e)
  68 {
  69     debugs(49, 3, HERE << e.what());
  70     if (fd >= 0)
  71         sendError(SNMP_ERR_GENERR);
  72     Ipc::Forwarder::handleException(e);
  73 }
  74
  75 /// send error SNMP response
  76 void
  77 Snmp::Forwarder::sendError(int error)
  78 {
  79     debugs(49, 3, HERE);
  80     Snmp::Request& req = static_cast<Snmp::Request&>(*request);
  81     req.pdu.command = SNMP_PDU_RESPONSE;
  82     req.pdu.errstat = error;
  83     u_char buffer[SNMP_REQUEST_SIZE];
  84     int len = sizeof(buffer);
  85     snmp_build(&req.session, &req.pdu, buffer, &len);
  86     comm_udp_sendto(fd, req.address, buffer, len);
  87 }
  88
  89 void
  90 Snmp::SendResponse(unsigned int requestId, const Pdu& pdu)
  91 {
  92     debugs(49, 5, HERE);
  93     // snmpAgentResponse() can modify arg
  94     Pdu tmp = pdu;
  95     Snmp::Response response(requestId);
  96     snmp_pdu* response_pdu = NULL;
  97     try {
  98         response_pdu = snmpAgentResponse(&tmp);
  99         Must(response_pdu != NULL);
 100         response.pdu = static_cast<Pdu&>(*response_pdu);
 101         snmp_free_pdu(response_pdu);
 102     } catch (const std::exception& e) {
 103         debugs(49, DBG_CRITICAL, HERE << e.what());
 104         response.pdu.command = SNMP_PDU_RESPONSE;
 105         response.pdu.errstat = SNMP_ERR_GENERR;
 106     }
 107     Ipc::TypedMsgHdr message;
 108     response.pack(message);
 109     Ipc::SendMessage(Ipc::Port::CoordinatorAddr(), message);
 110 }
 111