dhcp4/parser_context.cc

Go to the documentation of this file.

// Copyright (C) 2016-2021 Internet Systems Consortium, Inc. ("ISC")
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
// file, You can obtain one at http://mozilla.org/MPL/2.0/.

#include <config.h>

#include <dhcp4/parser_context.h>
#include <dhcp4/dhcp4_parser.h>
#include <dhcp4/dhcp4_log.h>
#include <exceptions/exceptions.h>
#include <cc/data.h>
#include <boost/lexical_cast.hpp>
#include <fstream>
#include <sstream>
#include <limits>

namespace isc {
namespace dhcp {

Parser4Context::Parser4Context()
    : sfile_(nullptr), ctx_(NO_KEYWORD), trace_scanning_(false),
      trace_parsing_(false) {
}

Parser4Context::~Parser4Context() {
}

isc::data::ElementPtr
Parser4Context::parseString(const std::string& str, ParserType parser_type) {
    scanStringBegin(str, parser_type);
    return (parseCommon());
}

isc::data::ElementPtr
Parser4Context::parseFile(const std::string& filename, ParserType parser_type) {
    FILE* f = fopen(filename.c_str(), "r");
    if (!f) {
        isc_throw(Dhcp4ParseError, "Unable to open file " << filename);
    }
    scanFileBegin(f, filename, parser_type);
    return (parseCommon());
}

isc::data::ElementPtr
Parser4Context::parseCommon() {
    isc::dhcp::Dhcp4Parser parser(*this);
    // Uncomment this to get detailed parser logs.
    // trace_parsing_ = true;
    parser.set_debug_level(trace_parsing_);
    try {
        int res = parser.parse();
        if (res != 0) {
            isc_throw(Dhcp4ParseError, "Parser abort");
        }
        scanEnd();
    }
    catch (...) {
        scanEnd();
        throw;
    }
    if (stack_.size() == 1) {
        return (stack_[0]);
    } else {
        isc_throw(Dhcp4ParseError, "Expected exactly one terminal Element expected, found "
                  << stack_.size());
    }
}

void
Parser4Context::error(const isc::dhcp::location& loc,
                      const std::string& what,
                      size_t pos) {
    if (pos == 0) {
        isc_throw(Dhcp4ParseError, loc << ": " << what);
    } else {
        isc_throw(Dhcp4ParseError, loc << " (near " << pos << "): " << what);
    }
}

void
Parser4Context::error(const std::string& what) {
    isc_throw(Dhcp4ParseError, what);
}

void
Parser4Context::fatal(const std::string& what) {
    isc_throw(Dhcp4ParseError, what);
}

isc::data::Element::Position
Parser4Context::loc2pos(isc::dhcp::location& loc) {
    const std::string& file = *loc.begin.filename;
    const uint32_t line = loc.begin.line;
    const uint32_t pos = loc.begin.column;
    return (isc::data::Element::Position(file, line, pos));
}

void
Parser4Context::require(const std::string& name,
                        isc::data::Element::Position open_loc,
                        isc::data::Element::Position close_loc) {
    ConstElementPtr value = stack_.back()->get(name);
    if (!value) {
        isc_throw(Dhcp4ParseError,
                  "missing parameter '" << name << "' ("
                  << stack_.back()->getPosition() << ") ["
                  << contextName() << " map between "
                  << open_loc << " and " << close_loc << "]");
    }
}

void
Parser4Context::unique(const std::string& name,
                       isc::data::Element::Position loc) {
    ConstElementPtr value = stack_.back()->get(name);
    if (value) {
        if (ctx_ != NO_KEYWORD) {
            isc_throw(Dhcp4ParseError, loc << ": duplicate " << name
                      << " entries in " << contextName()
                      << " map (previous at " << value->getPosition() << ")");
        } else {
            isc_throw(Dhcp4ParseError, loc << ": duplicate " << name
                      << " entries in JSON"
                      << " map (previous at " << value->getPosition() << ")");
        }

    }
}

void
Parser4Context::enter(const ParserContext& ctx) {
    cstack_.push_back(ctx_);
    ctx_ = ctx;
}

void
Parser4Context::leave() {
#if 1
    if (cstack_.empty()) {
        fatal("unbalanced syntactic context");
    }
#endif
    ctx_ = cstack_.back();
    cstack_.pop_back();
}

const std::string
Parser4Context::contextName() {
    switch (ctx_) {
    case NO_KEYWORD:
        return ("__no keyword__");
    case CONFIG:
        return ("toplevel");
    case DHCP4:
        return ("Dhcp4");
    case INTERFACES_CONFIG:
        return ("interfaces-config");
    case DHCP_SOCKET_TYPE:
        return ("dhcp-socket-type");
    case OUTBOUND_INTERFACE:
        return ("outbound-interface");
    case LEASE_DATABASE:
        return ("lease-database");
    case HOSTS_DATABASE:
        return ("hosts-database");
    case DATABASE_TYPE:
        return ("database-type");
    case DATABASE_ON_FAIL:
        return ("database-on-fail");
    case HOST_RESERVATION_IDENTIFIERS:
        return ("host-reservation-identifiers");
    case HOOKS_LIBRARIES:
        return ("hooks-libraries");
    case SUBNET4:
        return ("subnet4");
    case RESERVATION_MODE:
        return ("reservation-mode");
    case OPTION_DEF:
        return ("option-def");
    case OPTION_DATA:
        return ("option-data");
    case CLIENT_CLASSES:
        return ("client-classes");
    case EXPIRED_LEASES_PROCESSING:
        return ("expired-leases-processing");
    case SERVER_ID:
        return ("server-id");
    case CONTROL_SOCKET:
        return ("control-socket");
    case DHCP_QUEUE_CONTROL:
        return ("dhcp-queue-control");
    case DHCP_MULTI_THREADING:
        return ("multi-threading");
    case POOLS:
        return ("pools");
    case RESERVATIONS:
        return ("reservations");
    case RELAY:
        return ("relay");
    case LOGGERS:
        return ("loggers");
    case OUTPUT_OPTIONS:
        return ("output-options");
    case DHCP_DDNS:
        return ("dhcp-ddns");
    case NCR_PROTOCOL:
        return ("ncr-protocol");
    case NCR_FORMAT:
        return ("ncr-format");
    case REPLACE_CLIENT_NAME:
        return ("replace-client-name");
    case SHARED_NETWORK:
        return ("shared-networks");
    case SANITY_CHECKS:
        return ("sanity-checks");
    case CONFIG_CONTROL:
        return ("config-control");
    case CONFIG_DATABASE:
        return ("config-database");
    case COMPATIBILITY:
        return ("compatibility");
    default:
        return ("__unknown__");
    }
}

void
Parser4Context::warning(const isc::dhcp::location& loc,
                        const std::string& what) {
    std::ostringstream msg;
    msg << loc << ": " << what;
    LOG_WARN(dhcp4_logger, DHCP4_CONFIG_SYNTAX_WARNING)
        .arg(msg.str());
}

void
Parser4Context::warnAboutExtraCommas(const isc::dhcp::location& loc) {
    warning(loc, "Extraneous comma. A piece of configuration may have been omitted.");
}

}  // namespace dhcp
}  // namespace isc