segment_health_check.cc

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/*
 * Copyright (c) 2017 Juniper Networks, Inc. All rights reserved.
 */

#include <pkt/proto_handler.h>
#include <diag/diag_pkt_handler.h>
#include <diag/diag_proto.h>
#include <diag/segment_health_check.h>
#include <oper/health_check.h>
#include <oper/metadata_ip.h>

SegmentHealthCheckPkt::SegmentHealthCheckPkt(HealthCheckInstanceService *svc,
                                             DiagTable *diag_table) :
    DiagEntry(svc->source_ip().to_string(),
              svc->destination_ip().to_string(), IPPROTO_ICMP, 0, 0, "",
              ((svc->service()->timeout() * 1000) +
               (svc->service()->timeout_usecs()/1000)),
              svc->service()->max_retries(),
              diag_table), service_(svc), state_(SUCCESS) {
    delay_msecs_ = GetDelay(svc);
    delay_timer_ = TimerManager::CreateTimer
        (*(diag_table->agent()->event_manager())->io_service(),
         "SegmentHCDelayTimeoutHandler",
         TaskScheduler::GetInstance()->GetTaskId("Agent::Diag"),
         PktHandler::DIAG);
}


SegmentHealthCheckPkt::~SegmentHealthCheckPkt() {
    delay_timer_->Cancel();
    TimerManager::DeleteTimer(delay_timer_);
}

int SegmentHealthCheckPkt::GetDelay(const HealthCheckInstanceService *svc)
    const {
    /* Convert delay from seconds to milliseconds and store */
    int msecs = svc->service()->delay() * 1000;
    /* Convert delay_usecs from micro-seconds to milliseconds and update */
    msecs += svc->service()->delay_usecs() / 1000;
    return msecs;
}

int SegmentHealthCheckPkt::GetTimeout(const HealthCheckInstanceService *svc)
    const {
    /* Convert timeout from seconds to milliseconds and store */
    int msecs = svc->service()->timeout() * 1000;
    /* Convert timeout_usecs from micro-seconds to milliseconds and update */
    msecs += svc->service()->timeout_usecs() / 1000;
    return msecs;
}

void SegmentHealthCheckPkt::Retry() {
    delay_timer_->Cancel();
    delay_timer_->Start(delay_msecs_,
                       boost::bind(&SegmentHealthCheckPkt::RetryHandler, this));
}

bool SegmentHealthCheckPkt::RetryHandler() {
    SendRequest();
    RestartTimer();
    /* return false to suppress auto-restart of timer */
    return false;
}

void SegmentHealthCheckPkt::FillDiagHeader(AgentDiagPktData *data) const {
    data->op_ = htonl(AgentDiagPktData::DIAG_REQUEST);
    data->key_ = htons(key_);
    data->seq_no_ = htonl(seq_no_);
    strcpy(data->data_, DiagTable::kDiagData.c_str());
}

void SegmentHealthCheckPkt::SendRequest() {
    Agent *agent = diag_table_->agent();

    //Allocate buffer to hold packet
    boost::shared_ptr<PktInfo> pkt_info(new PktInfo(agent, kBufferSize,
                                                    PktHandler::DIAG, 0));
    uint8_t *msg = pkt_info->packet_buffer()->data();
    memset(msg, 0, kBufferSize);

    DiagPktHandler *pkt_handler =
        new DiagPktHandler(agent, pkt_info,
                           *(agent->event_manager())->io_service());
    uint16_t len = sizeof(AgentDiagPktData);
    uint8_t *data = NULL;
    if (sip_.is_v4()) {
        //Update pointers to ethernet header, ip header and l4 header
        pkt_info->UpdateHeaderPtr();
        switch (proto_) {
            case IPPROTO_ICMP:
                len += 8;
                data = (uint8_t *)pkt_handler->pkt_info()->transp.icmp + 8;
                pkt_handler->pkt_info()->transp.icmp->icmp_type = ICMP_ECHO;
                pkt_handler->pkt_info()->transp.icmp->icmp_code = 0;
                pkt_handler->pkt_info()->transp.icmp->icmp_cksum = 0xffff;
                break;
            default:
                assert(0);
        }
        //Add Diag header as ICMP payload
        FillDiagHeader((AgentDiagPktData *)data);
        len += sizeof(struct ip);
        pkt_handler->IpHdr(len, ntohl(sip_.to_v4().to_ulong()),
                           ntohl(dip_.to_v4().to_ulong()),
                           proto_, DEFAULT_IP_ID, DEFAULT_IP_TTL);
        len += sizeof(ether_header);
        InterfaceRef interface = service_->interface();

        uint32_t service_mode = (static_cast<VmInterface *>(interface.get()))->service_mode();
        bool l3_mode = false;
        MacAddress    dest_mac;
        if (service_mode == VmInterface::SERVICE_MODE_ERROR) {
            delete pkt_handler;
            return;
        }

        if ((service_mode == VmInterface::ROUTED_MODE) ||
            (service_mode == VmInterface::ROUTED_NAT_MODE)) {
            l3_mode = true;
            dest_mac = (static_cast<VmInterface *>(interface.get()))->vm_mac();
        }

        if ((static_cast<VmInterface *>(interface.get()))->is_left_si()) {
            if (l3_mode) {
                pkt_handler->EthHdr(agent->left_si_mac(), dest_mac,
                                    ETHERTYPE_IP);
            } else {
                pkt_handler->EthHdr(agent->left_si_mac(), agent->right_si_mac(),
                                    ETHERTYPE_IP);
            }
        } else {
            if (l3_mode) {
                pkt_handler->EthHdr(agent->right_si_mac(), dest_mac,
                                    ETHERTYPE_IP);
            } else {
                pkt_handler->EthHdr(agent->right_si_mac(), agent->left_si_mac(),
                                    ETHERTYPE_IP);
            }
        }
    } else {
        //TODO: support for IPv6
        assert(0);
    }
    //Increment the attempt count
    seq_no_++;

    //Send request out
    pkt_handler->pkt_info()->set_len(len);
    pkt_handler->Send(service_->interface()->id(),
                      service_->interface()->vrf_id(), AgentHdr::TX_SWITCH,
                      CMD_PARAM_PACKET_CTRL, CMD_PARAM_1_DIAG,
                      PktHandler::DIAG);
    delete pkt_handler;
    diag_table_->diag_proto()->IncrementDiagStats(service_->interface()->id(),
                                                  DiagProto::REQUESTS_SENT);
    return;
}

void SegmentHealthCheckPkt::RequestTimedOut(uint32_t seqno) {
    if (seq_no_ >= GetMaxAttempts()) {
        Notify(FAILURE);
        seq_no_ = 0;
    }
    Retry();
}

void SegmentHealthCheckPkt::HandleReply(DiagPktHandler *handler) {
    diag_table_->diag_proto()->IncrementDiagStats(service_->interface()->id(),
                                                  DiagProto::REPLIES_RECEIVED);
    seq_no_ = 0;
    Notify(SUCCESS);
    /* Cancel the timeout timer and start delay timer to resend the request */
    TimerCancel();
    Retry();
}

void SegmentHealthCheckPkt::StopDelayTimer() {
    delay_timer_->Cancel();
}

void SegmentHealthCheckPkt::Notify(Status status) {
    if (state_ != status) {
        state_ = status;
        std::string data = (state_ == SUCCESS) ? "success" : "failure";
        service_->OnRead(data);
    }
}

void SegmentHealthCheckPkt::UpdateService(HealthCheckInstanceService *service) {
    service_ = service;
    delay_msecs_ = GetDelay(service);
    timeout_ = GetTimeout(service);
    max_attempts_ = service->service()->max_retries();
}