kdeconnect-kde/core/backends/lan/mdns_wrapper.cpp
2023-12-02 14:56:20 +01:00

727 lines
30 KiB
C++

/**
* SPDX-FileCopyrightText: 2023 Albert Vaca Cintora <albertvaka@gmail.com>
*
* SPDX-License-Identifier: GPL-2.0-only OR GPL-3.0-only OR LicenseRef-KDE-Accepted-GPL
*/
#include "mdns_wrapper.h"
#include "core_debug.h"
#include "mdns.h"
#include <errno.h>
#include <QHostInfo>
#include <QNetworkInterface>
#include <QSocketNotifier>
namespace MdnsWrapper
{
const char *recordTypeToStr(int rtype)
{
switch (rtype) {
case MDNS_RECORDTYPE_PTR:
return "PTR";
case MDNS_RECORDTYPE_SRV:
return "SRV";
case MDNS_RECORDTYPE_TXT:
return "TXT";
case MDNS_RECORDTYPE_A:
return "A";
case MDNS_RECORDTYPE_AAAA:
return "AAAA";
case MDNS_RECORDTYPE_ANY:
return "ANY";
default:
return "UNKNOWN";
}
}
const char *entryTypeToStr(int entry)
{
switch (entry) {
case MDNS_ENTRYTYPE_QUESTION:
return "QUESTION";
case MDNS_ENTRYTYPE_ANSWER:
return "ANSWER";
case MDNS_ENTRYTYPE_AUTHORITY:
return "AUTHORITY";
case MDNS_ENTRYTYPE_ADDITIONAL:
return "ADDITIONAL";
default:
return "UNKNOWN";
}
}
static sockaddr_in qHostAddressToSockaddr(QHostAddress hostAddress)
{
Q_ASSERT(hostAddress.protocol() == QAbstractSocket::IPv4Protocol);
sockaddr_in socketAddress;
memset(&socketAddress, 0, sizeof(struct sockaddr_in));
socketAddress.sin_family = AF_INET;
socketAddress.sin_addr.s_addr = htonl(hostAddress.toIPv4Address());
return socketAddress;
}
static sockaddr_in6 qHostAddressToSockaddr6(QHostAddress hostAddress)
{
Q_ASSERT(hostAddress.protocol() == QAbstractSocket::IPv6Protocol);
sockaddr_in6 socketAddress;
memset(&socketAddress, 0, sizeof(struct sockaddr_in6));
socketAddress.sin6_family = AF_INET6;
Q_IPV6ADDR ipv6Address = hostAddress.toIPv6Address();
for (int i = 0; i < 16; ++i) {
socketAddress.sin6_addr.s6_addr[i] = ipv6Address[i];
}
return socketAddress;
}
// Callback that handles responses to a query
static int query_callback(int sock,
const struct sockaddr *from,
size_t addrlen,
mdns_entry_type_t entry_type,
uint16_t query_id,
uint16_t record_type,
uint16_t rclass,
uint32_t ttl,
const void *data,
size_t size,
size_t name_offset,
size_t name_length,
size_t record_offset,
size_t record_length,
void *user_data)
{
Q_UNUSED(sock);
Q_UNUSED(addrlen);
Q_UNUSED(query_id);
Q_UNUSED(entry_type);
Q_UNUSED(rclass);
Q_UNUSED(ttl);
Q_UNUSED(name_offset);
Q_UNUSED(name_length);
// qCDebug(KDECONNECT_CORE) << "Received DNS record of type" << recordTypeToStr(record_type) << "from socket" << sock << "with type" <<
// entryTypeToStr(entry_type);
Discoverer::MdnsService *discoveredService = (Discoverer::MdnsService *)user_data;
switch (record_type) {
case MDNS_RECORDTYPE_PTR: {
// We don't use mdns_record_parse_ptr() because we want to extract just the service name instead of the full
// "<instance-name>._<service-type>._tcp.local." string
mdns_string_pair_t instanceNamePos = mdns_get_next_substring(data, size, record_offset);
discoveredService->name = QString::fromLatin1((char *)data + instanceNamePos.offset, instanceNamePos.length);
// static char instanceNameBuffer[256];
// mdns_string_t instanceName = mdns_record_parse_ptr(data, size, record_offset, record_length, instanceNameBuffer, sizeof(instanceNameBuffer));
// discoveredService->name = QString::fromLatin1(instanceName.str, instanceName.length);
if (discoveredService->address == QHostAddress::Null) {
discoveredService->address = QHostAddress(from); // In case we don't receive a A record, use from as address
}
} break;
case MDNS_RECORDTYPE_SRV: {
static char nameBuffer[256];
mdns_record_srv_t record = mdns_record_parse_srv(data, size, record_offset, record_length, nameBuffer, sizeof(nameBuffer));
// We can use the IP to connect so we don't need to store the "<hostname>.local." address.
// discoveredService->qualifiedHostname = QString::fromLatin1(record.name.str, record.name.length);
discoveredService->port = record.port;
} break;
case MDNS_RECORDTYPE_A: {
sockaddr_in addr;
mdns_record_parse_a(data, size, record_offset, record_length, &addr);
discoveredService->address = QHostAddress(ntohl(addr.sin_addr.s_addr));
} break;
case MDNS_RECORDTYPE_AAAA:
// Ignore IPv6 for now
// sockaddr_in6 addr6;
// mdns_record_parse_aaaa(data, size, record_offset, record_length, &addr6);
break;
case MDNS_RECORDTYPE_TXT: {
mdns_record_txt_t records[24];
size_t parsed = mdns_record_parse_txt(data, size, record_offset, record_length, records, sizeof(records) / sizeof(mdns_record_txt_t));
for (size_t itxt = 0; itxt < parsed; ++itxt) {
QString key = QString::fromLatin1(records[itxt].key.str, records[itxt].key.length);
QString value = QString::fromLatin1(records[itxt].value.str, records[itxt].value.length);
discoveredService->txtRecords[key] = value;
}
} break;
default:
// Ignore unknown record types
break;
}
return 0;
}
void Discoverer::startDiscovering(const QString &serviceType)
{
int num_sockets = listenForQueryResponses();
if (num_sockets <= 0) {
qCWarning(KDECONNECT_CORE) << "Failed to open any MDNS server sockets";
return;
}
sendQuery(serviceType);
}
void Discoverer::stopDiscovering()
{
stopListeningForQueryResponses();
}
void Discoverer::stopListeningForQueryResponses()
{
qCDebug(KDECONNECT_CORE) << "Closing" << responseSocketNotifiers.size() << "sockets";
for (QSocketNotifier *socketNotifier : qAsConst(responseSocketNotifiers)) {
mdns_socket_close(socketNotifier->socket());
delete socketNotifier;
}
responseSocketNotifiers.clear();
}
int Discoverer::listenForQueryResponses()
{
// Open a socket for each interface
QVector<int> sockets;
for (const QNetworkInterface &iface : QNetworkInterface::allInterfaces()) {
int flags = iface.flags();
if (!(flags & QNetworkInterface::IsUp) || !(flags & QNetworkInterface::CanMulticast) || (flags & QNetworkInterface::IsLoopBack)) {
continue;
}
for (const QNetworkAddressEntry &ifaceAddress : iface.addressEntries()) {
QHostAddress sourceAddress = ifaceAddress.ip();
if (sourceAddress.protocol() == QAbstractSocket::IPv4Protocol && sourceAddress != QHostAddress::LocalHost) {
qCDebug(KDECONNECT_CORE) << "Opening socket for address" << sourceAddress;
struct sockaddr_in saddr = qHostAddressToSockaddr(sourceAddress);
int socket = mdns_socket_open_ipv4(&saddr);
if (socket >= 0) {
sockets.append(socket);
} else {
qCDebug(KDECONNECT_CORE) << "Couldn't open socket";
}
} else if (sourceAddress.protocol() == QAbstractSocket::IPv6Protocol && sourceAddress != QHostAddress::LocalHostIPv6) {
qCDebug(KDECONNECT_CORE) << "Opening socket for address6" << sourceAddress;
struct sockaddr_in6 saddr = qHostAddressToSockaddr6(sourceAddress);
int socket = mdns_socket_open_ipv6(&saddr);
if (socket >= 0) {
sockets.append(socket);
} else {
qCDebug(KDECONNECT_CORE) << "Couldn't open socket";
}
}
}
}
// Start listening on all sockets
for (int socket : std::as_const(sockets)) {
QSocketNotifier *socketNotifier = new QSocketNotifier(socket, QSocketNotifier::Read);
QObject::connect(socketNotifier, &QSocketNotifier::activated, [this](QSocketDescriptor socket) {
MdnsService discoveredService;
static char buffer[2048];
size_t num_records = mdns_query_recv(socket, buffer, sizeof(buffer), query_callback, (void *)&discoveredService, 0);
Q_UNUSED(num_records);
// qCDebug(KDECONNECT_CORE) << "Discovered service" << discoveredService.name << "at" << discoveredService.address << "in" << num_records <<
// "records via socket" << socket;
Q_EMIT serviceFound(discoveredService);
});
responseSocketNotifiers.append(socketNotifier);
}
qCDebug(KDECONNECT_CORE) << "Opened" << sockets.size() << "sockets to listen for MDNS query responses";
return sockets.size();
}
void Discoverer::sendQuery(const QString &serviceType)
{
qCDebug(KDECONNECT_CORE) << "Sending MDNS query for service" << serviceType;
mdns_query_t query;
QByteArray serviceTypeBytes = serviceType.toLatin1();
query.name = serviceTypeBytes.constData();
query.length = serviceTypeBytes.length();
query.type = MDNS_RECORDTYPE_PTR;
static char buffer[2048];
for (QSocketNotifier *socketNotifier : qAsConst(responseSocketNotifiers)) {
int socket = socketNotifier->socket();
qCDebug(KDECONNECT_CORE) << "Sending mDNS query via socket" << socket;
int ret = mdns_multiquery_send(socket, &query, 1, buffer, sizeof(buffer), 0);
if (ret < 0) {
qCWarning(KDECONNECT_CORE) << "Failed to send mDNS query:" << strerror(errno);
}
}
}
const QByteArray dnsSdName = QByteArray("_services._dns-sd._udp.local.");
static mdns_string_t createMdnsString(const QByteArray &str)
{
return mdns_string_t{str.constData(), (size_t)str.length()};
}
int countCommonLeadingBits(quint32 int1, quint32 int2)
{
int count = 0;
while (int1 != 0 && int2 != 0) {
if ((int1 & 0x80000000) == (int2 & 0x80000000)) {
count++;
int1 <<= 1;
int2 <<= 1;
} else {
break;
}
}
return count;
}
static QHostAddress findBestAddressMatchV4(const QVector<QHostAddress> &hostAddresses, const struct sockaddr *fromAddress)
{
Q_ASSERT(!hostAddresses.empty());
if (hostAddresses.size() == 1 || fromAddress == nullptr) {
return hostAddresses[0];
}
QHostAddress otherIp = QHostAddress(fromAddress);
if (otherIp.protocol() != QAbstractSocket::IPv4Protocol) {
return hostAddresses[0];
}
// qDebug() << "I have more than one IP address:" << hostAddresses << "- Finding best match for source IP:" << otherIp;
QHostAddress matchingIp = hostAddresses[0];
int matchingBits = -1;
quint32 rawOtherIp = otherIp.toIPv4Address();
for (const QHostAddress &ip : hostAddresses) {
Q_ASSERT(ip.protocol() == QAbstractSocket::IPv4Protocol);
quint32 rawMyIp = ip.toIPv4Address();
// Since we don't have the network mask, we just compare the prefixes of the IPs to find the longest match
int matchingBitsCount = countCommonLeadingBits(rawMyIp, rawOtherIp);
if (matchingBitsCount > matchingBits) {
matchingIp = ip;
matchingBits = matchingBitsCount;
}
}
// qDebug() << "Found match:" << matchingIp;
return matchingIp;
}
static QHostAddress findBestAddressMatchV6(const QVector<QHostAddress> &hostAddresses, const struct sockaddr *fromAddress)
{
Q_ASSERT(!hostAddresses.empty());
// We could do the same logic for v6 that we do for V4, but we don't care that much about IPv6
return hostAddresses[0];
Q_UNUSED(fromAddress);
}
static mdns_record_t createMdnsRecord(const Announcer::AnnouncedInfo &self,
mdns_record_type_t record_type,
const struct sockaddr *fromAddress = nullptr, // used to determine IP to set in A and AAAA records
QHash<QByteArray, QByteArray>::const_iterator txtIterator = {})
{
mdns_record_t answer;
answer.type = record_type;
answer.rclass = 0;
answer.ttl = 0;
switch (record_type) {
case MDNS_RECORDTYPE_PTR: // maps "_<service-type>._tcp.local." to "<instance-name>._<service-type>._tcp.local."
answer.name = createMdnsString(self.serviceType);
answer.data.ptr.name = createMdnsString(self.serviceInstance);
break;
case MDNS_RECORDTYPE_SRV: // maps "<instance-name>._<service-type>._tcp.local." to "<hostname>.local." and port
answer.name = createMdnsString(self.serviceInstance);
answer.data.srv.name = createMdnsString(self.hostname);
answer.data.srv.port = self.port;
answer.data.srv.priority = 0;
answer.data.srv.weight = 0;
break;
case MDNS_RECORDTYPE_A: // maps "<hostname>.local." to IPv4
answer.name = createMdnsString(self.hostname);
answer.data.a.addr = qHostAddressToSockaddr(findBestAddressMatchV4(self.addressesV4, fromAddress));
break;
case MDNS_RECORDTYPE_AAAA: // maps "<hostname>.local." to IPv6
answer.name = createMdnsString(self.hostname);
answer.data.aaaa.addr = qHostAddressToSockaddr6(findBestAddressMatchV6(self.addressesV6, fromAddress));
break;
case MDNS_RECORDTYPE_TXT:
answer.name = createMdnsString(self.serviceInstance);
answer.type = MDNS_RECORDTYPE_TXT;
answer.data.txt.key = createMdnsString(txtIterator.key());
answer.data.txt.value = createMdnsString(txtIterator.value());
break;
default:
Q_ASSERT(false);
}
return answer;
}
// Callback handling questions incoming on service sockets
static int service_callback(int sock,
const struct sockaddr *from,
size_t addrlen,
mdns_entry_type_t entry_type,
uint16_t query_id,
uint16_t record_type,
uint16_t rclass,
uint32_t ttl,
const void *data,
size_t size,
size_t name_offset,
size_t name_length,
size_t record_offset,
size_t record_length,
void *user_data)
{
Q_UNUSED(ttl);
Q_UNUSED(name_length);
Q_UNUSED(record_offset);
Q_UNUSED(record_length);
static char sendbuffer[2024];
const Announcer::AnnouncedInfo &self = *((Announcer::AnnouncedInfo *)user_data);
if (entry_type != MDNS_ENTRYTYPE_QUESTION) {
return 0;
}
static char nameBuffer[256];
mdns_string_t nameMdnsString = mdns_string_extract(data, size, &name_offset, nameBuffer, sizeof(nameBuffer));
QByteArray name = QByteArray(nameMdnsString.str, nameMdnsString.length);
int ret = 0;
if (name == dnsSdName) {
if ((record_type == MDNS_RECORDTYPE_PTR) || (record_type == MDNS_RECORDTYPE_ANY)) {
// The PTR query was for the DNS-SD domain, send answer with a PTR record for the service name we advertise.
mdns_record_t answer = createMdnsRecord(self, MDNS_RECORDTYPE_PTR);
uint16_t unicast = (rclass & MDNS_UNICAST_RESPONSE);
if (unicast) {
ret = mdns_query_answer_unicast(sock,
from,
addrlen,
sendbuffer,
sizeof(sendbuffer),
query_id,
(mdns_record_type_t)record_type,
nameMdnsString.str,
nameMdnsString.length,
answer,
nullptr,
0,
nullptr,
0);
} else {
ret = mdns_query_answer_multicast(sock, sendbuffer, sizeof(sendbuffer), answer, nullptr, 0, nullptr, 0);
}
}
} else if (name == self.serviceType) {
if ((record_type == MDNS_RECORDTYPE_PTR) || (record_type == MDNS_RECORDTYPE_ANY)) {
// The PTR query was for our service, answer a PTR record reverse mapping the queried service name
// to our service instance name and add additional records containing the SRV record mapping the
// service instance name to our qualified hostname and port, as well as any IPv4/IPv6 and TXT records
mdns_record_t answer = createMdnsRecord(self, MDNS_RECORDTYPE_PTR);
QVector<mdns_record_t> additional;
additional.append(createMdnsRecord(self, MDNS_RECORDTYPE_SRV));
if (!self.addressesV4.empty()) {
additional.append(createMdnsRecord(self, MDNS_RECORDTYPE_A, from));
}
if (!self.addressesV6.empty()) {
additional.append(createMdnsRecord(self, MDNS_RECORDTYPE_AAAA, from));
}
for (auto txtIterator = self.txtRecords.cbegin(); txtIterator != self.txtRecords.cend(); txtIterator++) {
additional.append(createMdnsRecord(self, MDNS_RECORDTYPE_TXT, nullptr, txtIterator));
}
uint16_t unicast = (rclass & MDNS_UNICAST_RESPONSE);
if (unicast) {
ret = mdns_query_answer_unicast(sock,
from,
addrlen,
sendbuffer,
sizeof(sendbuffer),
query_id,
(mdns_record_type_t)record_type,
nameMdnsString.str,
nameMdnsString.length,
answer,
nullptr,
0,
additional.constData(),
additional.length());
} else {
ret = mdns_query_answer_multicast(sock, sendbuffer, sizeof(sendbuffer), answer, nullptr, 0, additional.constData(), additional.length());
}
}
} else if (name == self.serviceInstance) {
if ((record_type == MDNS_RECORDTYPE_SRV) || (record_type == MDNS_RECORDTYPE_ANY)) {
// The SRV query was for our service instance, answer a SRV record mapping the service
// instance name to our qualified hostname (typically "<hostname>.local.") and port, as
// well as any IPv4/IPv6 address for the hostname as A/AAAA records and TXT records
mdns_record_t answer = createMdnsRecord(self, MDNS_RECORDTYPE_SRV);
QVector<mdns_record_t> additional;
if (!self.addressesV4.empty()) {
additional.append(createMdnsRecord(self, MDNS_RECORDTYPE_A, from));
}
if (!self.addressesV6.empty()) {
additional.append(createMdnsRecord(self, MDNS_RECORDTYPE_AAAA, from));
}
for (auto txtIterator = self.txtRecords.cbegin(); txtIterator != self.txtRecords.cend(); txtIterator++) {
additional.append(createMdnsRecord(self, MDNS_RECORDTYPE_TXT, nullptr, txtIterator));
}
uint16_t unicast = (rclass & MDNS_UNICAST_RESPONSE);
if (unicast) {
ret = mdns_query_answer_unicast(sock,
from,
addrlen,
sendbuffer,
sizeof(sendbuffer),
query_id,
(mdns_record_type_t)record_type,
nameMdnsString.str,
nameMdnsString.length,
answer,
nullptr,
0,
additional.constData(),
additional.length());
} else {
ret = mdns_query_answer_multicast(sock, sendbuffer, sizeof(sendbuffer), answer, nullptr, 0, additional.constData(), additional.length());
}
}
} else if (name == self.hostname) {
if (((record_type == MDNS_RECORDTYPE_A) || (record_type == MDNS_RECORDTYPE_ANY)) && !self.addressesV4.empty()) {
// The A query was for our qualified hostname and we have an IPv4 address, answer with an A
// record mapping the hostname to an IPv4 address, as well as an AAAA record and TXT records
mdns_record_t answer = createMdnsRecord(self, MDNS_RECORDTYPE_A, from);
QVector<mdns_record_t> additional;
if (!self.addressesV6.empty()) {
additional.append(createMdnsRecord(self, MDNS_RECORDTYPE_AAAA, from));
}
for (auto txtIterator = self.txtRecords.cbegin(); txtIterator != self.txtRecords.cend(); txtIterator++) {
additional.append(createMdnsRecord(self, MDNS_RECORDTYPE_TXT, nullptr, txtIterator));
}
uint16_t unicast = (rclass & MDNS_UNICAST_RESPONSE);
if (unicast) {
ret = mdns_query_answer_unicast(sock,
from,
addrlen,
sendbuffer,
sizeof(sendbuffer),
query_id,
(mdns_record_type_t)record_type,
nameMdnsString.str,
nameMdnsString.length,
answer,
nullptr,
0,
additional.constData(),
additional.length());
} else {
ret = mdns_query_answer_multicast(sock, sendbuffer, sizeof(sendbuffer), answer, nullptr, 0, additional.constData(), additional.length());
}
} else if (((record_type == MDNS_RECORDTYPE_AAAA) || (record_type == MDNS_RECORDTYPE_ANY)) && !self.addressesV6.empty()) {
// The AAAA query was for our qualified hostname and we have an IPv6 address, answer with an AAAA
// record mapping the hostname to an IPv4 address, as well as an A record and TXT records
mdns_record_t answer = createMdnsRecord(self, MDNS_RECORDTYPE_AAAA, from);
QVector<mdns_record_t> additional;
if (!self.addressesV4.empty()) {
additional.append(createMdnsRecord(self, MDNS_RECORDTYPE_A, from));
}
for (auto txtIterator = self.txtRecords.cbegin(); txtIterator != self.txtRecords.cend(); txtIterator++) {
additional.append(createMdnsRecord(self, MDNS_RECORDTYPE_TXT, nullptr, txtIterator));
}
uint16_t unicast = (rclass & MDNS_UNICAST_RESPONSE);
if (unicast) {
ret = mdns_query_answer_unicast(sock,
from,
addrlen,
sendbuffer,
sizeof(sendbuffer),
query_id,
(mdns_record_type_t)record_type,
nameMdnsString.str,
nameMdnsString.length,
answer,
nullptr,
0,
additional.constData(),
additional.length());
} else {
ret = mdns_query_answer_multicast(sock, sendbuffer, sizeof(sendbuffer), answer, nullptr, 0, additional.constData(), additional.length());
}
}
} // else request is not for me
if (ret < 0) {
qCWarning(KDECONNECT_CORE) << "Error sending MDNS query response";
}
return ret;
}
// Open sockets to listen to incoming mDNS queries on port 5353
// When recieving, each socket can recieve data from all network interfaces
// Thus we only need to open one socket for each address family
int Announcer::listenForQueries()
{
auto callback = [this](QSocketDescriptor socket) {
static char buffer[2048];
mdns_socket_listen(socket, buffer, sizeof(buffer), service_callback, &self);
};
int numSockets = 0;
{
struct sockaddr_in sock_addr;
memset(&sock_addr, 0, sizeof(struct sockaddr_in));
sock_addr.sin_family = AF_INET;
#ifdef _WIN32
sock_addr.sin_addr = in4addr_any;
#else
sock_addr.sin_addr.s_addr = INADDR_ANY;
#endif
sock_addr.sin_port = htons(MDNS_PORT);
#ifdef __APPLE__
sock_addr.sin_len = sizeof(struct sockaddr_in);
#endif
int socket = mdns_socket_open_ipv4(&sock_addr);
if (socket >= 0) {
socketNotifier = new QSocketNotifier(socket, QSocketNotifier::Read);
QObject::connect(socketNotifier, &QSocketNotifier::activated, callback);
numSockets++;
}
}
{
struct sockaddr_in6 sock_addr;
memset(&sock_addr, 0, sizeof(struct sockaddr_in6));
sock_addr.sin6_family = AF_INET6;
sock_addr.sin6_addr = in6addr_any;
sock_addr.sin6_port = htons(MDNS_PORT);
#ifdef __APPLE__
sock_addr.sin6_len = sizeof(struct sockaddr_in6);
#endif
int socket = mdns_socket_open_ipv6(&sock_addr);
if (socket >= 0) {
socketNotifierV6 = new QSocketNotifier(socket, QSocketNotifier::Read);
QObject::connect(socketNotifierV6, &QSocketNotifier::activated, callback);
numSockets++;
}
}
return numSockets;
}
Announcer::Announcer(const QString &instanceName, const QString &serviceType, uint16_t port)
{
self.serviceType = serviceType.toLatin1();
if (!self.serviceType.endsWith('.')) {
// mdns.h needs all the qualified names to end with dot for some reason
self.serviceType.append('.');
}
self.serviceInstance = instanceName.toLatin1() + '.' + self.serviceType;
self.hostname = QHostInfo::localHostName().toLatin1() + ".local.";
self.port = port;
detectHostAddresses();
}
void Announcer::detectHostAddresses()
{
self.addressesV4.clear();
self.addressesV6.clear();
for (const QNetworkInterface &iface : QNetworkInterface::allInterfaces()) {
int flags = iface.flags();
if (!(flags & QNetworkInterface::IsUp) || !(flags & QNetworkInterface::CanMulticast) || (flags & QNetworkInterface::IsLoopBack)) {
continue;
}
for (const QNetworkAddressEntry &ifaceAddress : iface.addressEntries()) {
QHostAddress sourceAddress = ifaceAddress.ip();
if (sourceAddress.protocol() == QAbstractSocket::IPv4Protocol && sourceAddress != QHostAddress::LocalHost) {
self.addressesV4.append(sourceAddress);
} else if (sourceAddress.protocol() == QAbstractSocket::IPv6Protocol && sourceAddress != QHostAddress::LocalHostIPv6) {
self.addressesV6.append(sourceAddress);
}
}
}
}
void Announcer::startAnnouncing()
{
int num_sockets = listenForQueries();
if (num_sockets <= 0) {
qCWarning(KDECONNECT_CORE) << "Failed to open any MDNS client sockets";
return;
}
sendMulticastAnnounce(false);
}
void Announcer::stopAnnouncing()
{
sendMulticastAnnounce(true);
stopListeningForQueries();
}
void Announcer::stopListeningForQueries()
{
delete socketNotifier;
socketNotifier = nullptr;
delete socketNotifierV6;
socketNotifierV6 = nullptr;
}
void Announcer::sendMulticastAnnounce(bool isGoodbye)
{
mdns_record_t ptr_record = createMdnsRecord(self, MDNS_RECORDTYPE_PTR);
QVector<mdns_record_t> additional;
additional.append(createMdnsRecord(self, MDNS_RECORDTYPE_SRV));
if (!self.addressesV4.empty()) {
additional.append(createMdnsRecord(self, MDNS_RECORDTYPE_A));
}
if (!self.addressesV6.empty()) {
additional.append(createMdnsRecord(self, MDNS_RECORDTYPE_AAAA));
}
for (auto txtIterator = self.txtRecords.cbegin(); txtIterator != self.txtRecords.cend(); txtIterator++) {
additional.append(createMdnsRecord(self, MDNS_RECORDTYPE_TXT, nullptr, txtIterator));
}
static char buffer[2048];
if (isGoodbye) {
qCDebug(KDECONNECT_CORE) << "Sending goodbye";
if (socketNotifier)
mdns_goodbye_multicast(socketNotifier->socket(), buffer, sizeof(buffer), ptr_record, nullptr, 0, additional.constData(), additional.length());
if (socketNotifierV6)
mdns_goodbye_multicast(socketNotifierV6->socket(), buffer, sizeof(buffer), ptr_record, nullptr, 0, additional.constData(), additional.length());
} else {
qCDebug(KDECONNECT_CORE) << "Sending announce";
if (socketNotifier)
mdns_announce_multicast(socketNotifier->socket(), buffer, sizeof(buffer), ptr_record, nullptr, 0, additional.constData(), additional.length());
if (socketNotifierV6)
mdns_announce_multicast(socketNotifierV6->socket(), buffer, sizeof(buffer), ptr_record, nullptr, 0, additional.constData(), additional.length());
}
}
} // namespace MdnsWrapper