NameServer.cpp

Go to the documentation of this file.

/*
 * SPDX-FileCopyrightText: 2006-2021 Istituto Italiano di Tecnologia (IIT)
 * SPDX-FileCopyrightText: 2006-2010 RobotCub Consortium
 * SPDX-License-Identifier: BSD-3-Clause
 */
 
#include <yarp/os/impl/NameServer.h>
 
#include <yarp/conf/string.h>
#include <yarp/conf/version.h>
 
#include <yarp/os/ConnectionWriter.h>
#include <yarp/os/ManagedBytes.h>
#include <yarp/os/NetType.h>
#include <yarp/os/Network.h>
#include <yarp/os/Port.h>
#include <yarp/os/Property.h>
#include <yarp/os/Time.h>
#include <yarp/os/Value.h>
#include <yarp/os/Vocab.h>
#include <yarp/os/impl/LogComponent.h>
#include <yarp/os/impl/NameConfig.h>
 
#include <map>
#include <set>
 
using namespace yarp::os::impl;
using namespace yarp::os;
 
YARP_OS_LOG_COMPONENT(NAMESERVER, "yarp.os.impl.NameServer")
 
// produce a correctly parsed string in presence of quoting
static std::string STR_HELP(const char* txt)
{
    Value v;
    v.fromString(txt);
    return v.asString();
}
#define STR(x) STR_HELP(x).c_str()
 
//
// Basic functionality
//
 
 
Contact NameServer::unregisterName(const std::string& name)
{
    Contact prev = queryName(name);
    if (prev.isValid()) {
        if (prev.getPort() != -1) {
            NameRecord& rec = getNameRecord(prev.getRegName());
            if (rec.isReusablePort()) {
                HostRecord& host = getHostRecord(prev.getHost());
                host.release(prev.getPort());
            }
            if (rec.isReusableIp()) {
                if (rec.getAddress().getCarrier() == "mcast") {
                    mcastRecord.releaseAddress(rec.getAddress().getHost().c_str());
                }
            }
            rec.clear();
            tmpNames.release(name);
 
            Bottle event;
            event.addVocab32("del");
            event.addString(name.c_str());
            onEvent(event);
        }
    }
 
    return queryName(name);
}
 
 
Contact NameServer::registerName(const std::string& name,
                                 const Contact& address,
                                 const std::string& remote)
{
    bool reusablePort = false;
    bool reusableIp = false;
 
    yCTrace(NAMESERVER, "in registerName...");
 
    if (name != "...") {
        unregisterName(name);
    }
 
    Contact suggestion = address;
 
    if (!suggestion.isValid()) {
        suggestion = Contact(name, "...", "...", 0);
    }
 
    std::string portName = name;
    if (portName == "...") {
        portName = tmpNames.get();
    }
 
    std::string carrier = suggestion.getCarrier();
    if (carrier == "...") {
        carrier = "tcp";
    }
 
    std::string machine = suggestion.getHost();
    int overridePort = 0;
    if (machine == "...") {
        if (carrier != "mcast") {
            if (remote == "...") {
                yCError(NAMESERVER, "remote machine name was not found!  can only guess it is local...");
                machine = "127.0.0.1";
            } else {
                machine = remote;
            }
        } else {
            machine = mcastRecord.get();
            overridePort = mcastRecord.lastPortNumber();
            reusableIp = true;
        }
    }
 
    int port = suggestion.getPort();
    if (port == 0) {
        if (overridePort != 0) {
            port = overridePort;
        } else {
            port = getHostRecord(machine).get();
            reusablePort = true;
        }
    }
 
    suggestion = Contact(portName, carrier, machine, port);
 
    yCDebug(NAMESERVER, "Registering %s for %s", suggestion.toURI().c_str(), suggestion.getRegName().c_str());
 
    NameRecord& nameRecord = getNameRecord(suggestion.getRegName());
    nameRecord.setAddress(suggestion, reusablePort, reusableIp);
 
    Bottle event;
    event.addVocab32("add");
    event.addString(suggestion.getRegName().c_str());
    onEvent(event);
 
    return nameRecord.getAddress();
}
 
 
Contact NameServer::queryName(const std::string& name)
{
    std::string base = name;
    std::string pat;
    if (name.find("/net=") == 0) {
        constexpr size_t patStart = 5;
        size_t patEnd = name.find('/', patStart);
        if (patEnd >= patStart && patEnd != std::string::npos) {
            pat = name.substr(patStart, patEnd - patStart);
            base = name.substr(patEnd);
            yCDebug(NAMESERVER, "Special query form %s (%s/%s)", name.c_str(), pat.c_str(), base.c_str());
        }
    }
 
    NameRecord* rec = getNameRecord(base, false);
    if (rec != nullptr) {
        if (!pat.empty()) {
            std::string ip = rec->matchProp("ips", pat);
            if (!ip.empty()) {
                auto sip = yarp::conf::string::split(ip, ' ');
                Contact c = rec->getAddress();
                c.setHost(sip.at(0));
                return c;
            }
        }
        return rec->getAddress();
    }
    return Contact();
}
 
 
NameServer::NameRecord* NameServer::getNameRecord(const std::string& name,
                                                  bool create)
{
    auto entry = nameMap.find(name);
    if (entry == nameMap.end()) {
        if (!create) {
            return nullptr;
        }
        nameMap.emplace(name, NameRecord());
        entry = nameMap.find(name);
    }
    yCAssert(NAMESERVER, entry != nameMap.end());
    return &(entry->second);
}
 
 
NameServer::HostRecord* NameServer::getHostRecord(const std::string& name,
                                                  bool create)
{
    auto entry = hostMap.find(name);
    if (entry == hostMap.end()) {
        if (!create) {
            return nullptr;
        }
        hostMap[name] = HostRecord();
        entry = hostMap.find(name);
        entry->second.setBase(basePort);
    }
    yCAssert(NAMESERVER, entry != hostMap.end());
    return &(entry->second);
}
 
 
//
// Remote interface
//
 
 
void NameServer::setup()
{
 
    basePort = NetworkBase::getDefaultPortRange() + 2;
 
    dispatcher.add("register", &NameServer::cmdRegister);
    dispatcher.add("unregister", &NameServer::cmdUnregister);
    dispatcher.add("query", &NameServer::cmdQuery);
    dispatcher.add("help", &NameServer::cmdHelp);
    dispatcher.add("set", &NameServer::cmdSet);
    dispatcher.add("get", &NameServer::cmdGet);
    dispatcher.add("check", &NameServer::cmdCheck);
    dispatcher.add("match", &NameServer::cmdMatch);
    dispatcher.add("list", &NameServer::cmdList);
    dispatcher.add("route", &NameServer::cmdRoute);
    dispatcher.add("gc", &NameServer::cmdGarbageCollect);
    dispatcher.add("bot", &NameServer::cmdBot);
    dispatcher.add("announce", &NameServer::cmdAnnounce);
 
    ndispatcher.add("list", &NameServer::ncmdList);
    ndispatcher.add("query", &NameServer::ncmdQuery);
    ndispatcher.add("version", &NameServer::ncmdVersion);
    ndispatcher.add("set", &NameServer::ncmdSet);
    ndispatcher.add("get", &NameServer::ncmdGet);
}
 
std::string NameServer::cmdRegister(int argc, char* argv[])
{
 
    std::string remote = argv[0];
    argc--;
    argv++;
 
    if (argc < 1) {
        return "need at least one argument";
    }
    std::string portName = STR(argv[0]);
 
    std::string machine = "...";
    std::string carrier = "...";
    int port = 0;
    if (argc >= 2) {
        carrier = argv[1];
    }
    if (argc >= 3) {
        machine = argv[2];
    }
    if (argc >= 4) {
        if (std::string("...") == argv[3]) {
            port = 0;
        } else {
            port = yarp::conf::numeric::from_string<int>(argv[3]);
        }
    }
 
    Contact address = registerName(portName, Contact(portName, carrier, machine, port), remote);
 
    yCDebug(NAMESERVER, "name server register address -- %s", address.toString().c_str());
 
    return terminate(textify(address));
}
 
 
std::string NameServer::cmdQuery(int argc, char* argv[])
{
    // ignore source
    argc--;
    argv++;
 
    if (argc < 1) {
        return "need at least one argument";
    }
    std::string portName = STR(argv[0]);
    Contact address = queryName(portName);
    return terminate(textify(address));
}
 
std::string NameServer::cmdUnregister(int argc, char* argv[])
{
    // ignore source
    argc--;
    argv++;
 
    if (argc < 1) {
        return "need at least one argument";
    }
    std::string portName = STR(argv[0]);
    Contact address = unregisterName(portName);
    return terminate(textify(address));
}
 
 
std::string NameServer::cmdAnnounce(int argc, char* argv[])
{
    // ignore source
    argc--;
    argv++;
 
    return terminate("ok\n");
}
 
std::string NameServer::cmdRoute(int argc, char* argv[])
{
    // ignore source
    argc--;
    argv++;
 
    if (argc < 2) {
        return terminate("need at least two arguments: the source port and the target port\n(followed by an optional list of carriers in decreasing order of desirability)");
    }
    std::string src = STR(argv[0]);
    std::string dest = STR(argv[1]);
 
    argc -= 2;
    argv += 2;
 
    const char* altArgv[] = {
        "local",
        "shmem",
        "mcast",
        "udp",
        "tcp",
        "text"};
    int altArgc = 6;
 
    if (argc == 0) {
        argc = altArgc;
        argv = (char**)altArgv;
    }
 
 
    NameRecord& srcRec = getNameRecord(src);
    NameRecord& destRec = getNameRecord(dest);
    std::string pref;
 
    for (int i = 0; i < argc; i++) {
        std::string carrier = argv[i];
        if (srcRec.checkProp("offers", carrier) && destRec.checkProp("accepts", carrier)) {
            bool ok = true;
            if (carrier == "local" || carrier == "shmem") {
                if (srcRec.getProp("ips") == destRec.getProp("ips")) {
                    if (carrier == "local") {
                        if (srcRec.getProp("process") != destRec.getProp("process")) {
                            ok = false;
                        }
                    }
                } else {
                    ok = false;
                }
            }
            if (ok) {
                pref = carrier;
                break;
            }
        }
    }
    if (!pref.empty()) {
        pref = pref + ":/" + dest;
    } else {
        pref = dest;
    }
 
    std::string result = "port ";
    result += src + " route " + dest + " = " + pref + "\n";
    return terminate(result);
}
 
 
std::string NameServer::cmdHelp(int argc, char* argv[])
{
    // ignore source
    argc--;
    argv++;
 
    std::string result = "Here are some ways to use the name server:\n";
    //ACE_Vector<std::string> names = dispatcher.getNames();
    //for (unsigned i=0; i<names.size(); i++) {
    //const std::string& name = names[i];
    //result += std::string("   ") + name + " ...\n";
    //}
    result += std::string("+ help\n");
    result += std::string("+ list\n");
    result += std::string("+ register $portname\n");
    result += std::string("+ register $portname $carrier $ipAddress $portNumber\n");
    result += std::string("  (if you want a field set automatically, write '...')\n");
    result += std::string("+ unregister $portname\n");
    result += std::string("+ query $portname\n");
    result += std::string("+ set $portname $property $value\n");
    result += std::string("+ get $portname $property\n");
    result += std::string("+ check $portname $property\n");
    result += std::string("+ match $portname $property $prefix\n");
    result += std::string("+ route $port1 $port2\n");
    result += std::string("+ gc\n");
    return terminate(result);
}
 
 
std::string NameServer::cmdSet(int argc, char* argv[])
{
    // ignore source
    argc--;
    argv++;
 
    if (argc < 2) {
        return "need at least two arguments: the port name, and a key";
    }
    std::string target = STR(argv[0]);
    std::string key = argv[1];
    NameRecord& nameRecord = getNameRecord(target);
    nameRecord.clearProp(key);
    for (int i = 2; i < argc; i++) {
        nameRecord.addProp(key, argv[i]);
    }
    return terminate(std::string("port ") + target + " property " + key + " = " + nameRecord.getProp(key) + "\n");
}
 
std::string NameServer::cmdGet(int argc, char* argv[])
{
    // ignore source
    argc--;
    argv++;
 
    if (argc < 2) {
        return "need exactly two arguments: the port name, and a key";
    }
    std::string target = STR(argv[0]);
    std::string key = argv[1];
    NameRecord& nameRecord = getNameRecord(target);
    return terminate(std::string("port ") + target + " property " + key + " = " + nameRecord.getProp(key) + "\n");
}
 
std::string NameServer::cmdMatch(int argc, char* argv[])
{
    // ignore source
    argc--;
    argv++;
 
    if (argc < 3) {
        return "need exactly three arguments: the port name, a key, and a prefix";
    }
    std::string target = STR(argv[0]);
    std::string key = argv[1];
    std::string prefix = argv[2];
    NameRecord& nameRecord = getNameRecord(target);
    return terminate(std::string("port ") + target + " property " + key + " = " + nameRecord.matchProp(key, prefix) + "\n");
}
 
std::string NameServer::cmdCheck(int argc, char* argv[])
{
    // ignore source
    argc--;
    argv++;
 
    if (argc < 2) {
        return "need at least two arguments: the port name, and a key";
    }
    std::string response;
    std::string target = STR(argv[0]);
    std::string key = argv[1];
    NameRecord& nameRecord = getNameRecord(target);
    for (int i = 2; i < argc; i++) {
        std::string val = "false";
        if (nameRecord.checkProp(key, argv[i])) {
            val = "true";
        }
        if (i > 2) {
            response += "\n";
        }
        response.append("port ").append(target).append(" property ").append(key).append(" value ").append(argv[i]).append(" present ").append(val);
    }
    response += "\n";
    return terminate(response);
}
 
 
std::string NameServer::cmdList(int argc, char* argv[])
{
    YARP_UNUSED(argc);
    YARP_UNUSED(argv);
    std::string response;
 
    std::multiset<std::string> lines;
    for (auto& it : nameMap) {
        NameRecord& rec = it.second;
        lines.insert(textify(rec.getAddress()));
    }
 
    // return result in alphabetical order
    for (const auto& line : lines) {
        response += line;
    }
 
    return terminate(response);
}
 
 
std::string NameServer::cmdBot(int argc, char* argv[])
{
    std::string txt;
    argc--;
    argv++;
    if (argc >= 1) {
        std::string key = argv[0];
        argc--;
        argv++;
        Bottle result = ndispatcher.dispatch(this, key.c_str(), argc, argv);
        txt = result.toString();
    }
    return txt;
}
 
 
Bottle NameServer::ncmdList(int argc, char* argv[])
{
    Bottle response;
 
    std::string prefix;
 
    if (argc == 1) {
        prefix = STR(argv[0]);
    }
 
    response.addString("ports");
    for (auto& it : nameMap) {
        NameRecord& rec = it.second;
        std::string iname = rec.getAddress().getRegName();
        if (iname.find(prefix) == 0) {
            if (iname == prefix || iname[prefix.length()] == '/' || prefix[prefix.length() - 1] == '/') {
                if (rec.getAddress().isValid()) {
                    response.addList() = botify(rec.getAddress());
                }
            }
        }
    }
 
    return response;
}
 
 
yarp::os::Bottle NameServer::ncmdQuery(int argc, char* argv[])
{
    Bottle response;
    if (argc == 1) {
        std::string portName = STR(argv[0]);
        Contact address = queryName(portName);
        response = botify(address);
    }
    return response;
}
 
 
yarp::os::Bottle NameServer::ncmdVersion(int argc, char* argv[])
{
    YARP_UNUSED(argc);
    YARP_UNUSED(argv);
    Bottle response;
    response.addString("version");
    response.addString(YARP_VERSION);
    return response;
}
 
 
yarp::os::Bottle NameServer::ncmdSet(int argc, char* argv[])
{
 
    Bottle response;
    if (argc >= 2) {
        std::string target = STR(argv[0]);
        std::string key = STR(argv[1]);
        NameRecord& nameRecord = getNameRecord(target);
        nameRecord.clearProp(key);
        for (int i = 2; i < argc; i++) {
            nameRecord.addProp(key, argv[i]);
        }
        response.addString("ok");
    }
    return response;
}
 
yarp::os::Bottle NameServer::ncmdGet(int argc, char* argv[])
{
    Bottle response;
    if (argc == 2) {
        std::string target = STR(argv[0]);
        std::string key = argv[1];
        NameRecord& nameRecord = getNameRecord(target);
        return Bottle(nameRecord.getProp(key));
    }
    return response;
}
 
 
std::string NameServer::cmdGarbageCollect(int argc, char* argv[])
{
    YARP_UNUSED(argc);
    YARP_UNUSED(argv);
    std::string response;
 
    response = "No cleaning done.\n";
 
    return terminate(response);
}
 
 
std::string NameServer::textify(const Contact& address)
{
    std::string result;
    if (address.isValid()) {
        if (address.getPort() >= 0) {
            result = "registration name ";
            result = result + address.getRegName() + " ip " + address.getHost() + " port " + yarp::conf::numeric::to_string(address.getPort()) + " type " + address.getCarrier() + "\n";
        } else {
            result = "registration name ";
            result = result + address.getRegName() + " ip " + "none" + " port " + "none" + " type " + address.getCarrier() + "\n";
        }
    }
    return result;
}
 
 
Bottle NameServer::botify(const Contact& address)
{
    Bottle result;
    if (address.isValid()) {
        Bottle bname;
        bname.addString("name");
        bname.addString(address.getRegName().c_str());
        Bottle bip;
        bip.addString("ip");
        bip.addString(address.getHost().c_str());
        Bottle bnum;
        bnum.addString("port_number");
        bnum.addInt32(address.getPort());
        Bottle bcarrier;
        bcarrier.addString("carrier");
        bcarrier.addString(address.getCarrier().c_str());
 
        result.addString("port");
        result.addList() = bname;
        result.addList() = bip;
        result.addList() = bnum;
        result.addList() = bcarrier;
    } else {
        Bottle bstate;
        bstate.addString("error");
        bstate.addInt32(-2);
        bstate.addString("port not known");
        result.addString("port");
        result.addList() = bstate;
    }
    return result;
}
 
 
static std::string ns_terminate(const std::string& str)
{
    return str + "*** end of message";
}
 
std::string NameServer::terminate(const std::string& str)
{
    return ns_terminate(str);
}
 
 
std::string NameServer::apply(const std::string& txt, const Contact& remote)
{
    std::string result = "no command given";
    mutex.lock();
    auto ss = yarp::conf::string::split(txt, std::regex{"[\" \t\n]+"});
    if (ss.size() >= 2) {
        std::string key = ss.at(1);
        yCTrace(NAMESERVER, "dispatching to %s", key.c_str());
        ss.at(1) = remote.getHost();
 
        // Create argc/argv containing all arguments but the first one
        std::vector<char*> args;
        args.reserve(ss.size());
        std::transform(ss.begin() + 1, ss.end(), std::back_inserter(args), [](const std::string& str) { return const_cast<char*>(str.c_str()); });
        args.push_back(nullptr);
        int argc = static_cast<int>(args.size()) - 1;
        char** argv = args.data();
 
        result = dispatcher.dispatch(this, key.c_str(), argc, argv);
        if (result.empty()) {
            Bottle b = ndispatcher.dispatch(this, key.c_str(), argc, argv);
            result = b.toString();
            if (!result.empty()) {
                result = result + "\n";
                result = terminate(result);
            }
        }
        yCTrace(NAMESERVER, "name server request -- %s", txt.c_str());
        yCTrace(NAMESERVER, "name server result  -- %s", result.c_str());
    }
    mutex.unlock();
    return result;
}
 
 
bool NameServer::apply(const Bottle& cmd, Bottle& result, const Contact& remote)
{
    Bottle rcmd;
    rcmd.addString("ignored_legacy");
    rcmd.append(cmd);
    std::string in = rcmd.toString();
    std::string out = apply(in, remote);
    result.fromString(out);
    return true;
}
 
 
#ifndef DOXYGEN_SHOULD_SKIP_THIS
 
class MainNameServerWorker :
        public PortReader
{
private:
    NameServer* server;
 
public:
    MainNameServerWorker(NameServer* server)
    {
        this->server = server;
    }
 
    bool read(ConnectionReader& reader) override
    {
        yCTrace(NAMESERVER, "read start");
        std::string ref = "NAME_SERVER ";
        bool ok = true;
        std::string msg = "?";
        bool haveMessage = false;
        if (ok) {
            if (reader.isTextMode()) {
                msg = reader.expectText();
            } else {
                // migrate to binary mode support, eventually optimize
                Bottle b;
                b.read(reader);
                msg = b.toString();
            }
            haveMessage = (!msg.empty());
            msg = ref + msg;
        }
        if (reader.isActive() && haveMessage) {
            yCDebug(NAMESERVER, "name server got message %s", msg.c_str());
            size_t index = msg.find("NAME_SERVER");
            if (index == 0) {
                Contact remote = reader.getRemoteContact();
                yCDebug(NAMESERVER, "name server receiving from %s", remote.toURI().c_str());
                yCDebug(NAMESERVER, "name server request is %s", msg.c_str());
                std::string result = server->apply(msg, remote);
                ConnectionWriter* os = reader.getWriter();
                if (os != nullptr) {
                    if (result.empty()) {
                        result = ns_terminate(std::string("unknown command ") + msg + "\n");
                    }
                    // This change is just to make Microsoft Telnet happy
                    std::string tmp;
                    for (char i : result) {
                        if (i == '\n') {
                            tmp += '\r';
                        }
                        tmp += i;
                    }
                    tmp += '\r';
                    os->appendText(tmp);
 
                    yCDebug(NAMESERVER, "name server reply is %s", result.c_str());
                    std::string resultSparse = result;
                    size_t end = resultSparse.find("\n*** end of message");
                    if (end != std::string::npos) {
                        resultSparse[end] = '\0';
                    }
                    yCInfo(NAMESERVER, "%s", resultSparse.c_str());
                }
            } else {
                yCInfo(NAMESERVER, "Name server ignoring unknown command: %s", msg.c_str());
            }
        }
        yCTrace(NAMESERVER, "read stop");
        return true;
    }
};
 
 
class MainNameServer :
        public NameServer,
        public PortReaderCreator
{
private:
    Port* port;
 
public:
    MainNameServer(int basePort, Port* port = nullptr) :
            port(port)
    {
        setBasePort(basePort);
    }
 
    void setPort(Port& port)
    {
        this->port = &port;
    }
 
    void onEvent(Bottle& event) override
    {
        if (port != nullptr) {
            port->write(event);
        }
    }
 
    PortReader* create() const override
    {
        return new MainNameServerWorker(const_cast<MainNameServer*>(this));
    }
};
 
 
#endif // DOXYGEN_SHOULD_SKIP_THIS