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/*
* Copyright (C) 2010 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "MDnsSdListener.h"
#include <arpa/inet.h>
#include <dirent.h>
#include <errno.h>
#include <inttypes.h>
#include <linux/if.h>
#include <netdb.h>
#include <netinet/in.h>
#include <pthread.h>
#include <resolv.h>
#include <stdlib.h>
#include <string.h>
#include <sys/poll.h>
#include <sys/socket.h>
#include <sys/types.h>
#define LOG_TAG "MDnsDS"
#define DBG 1
#define VDBG 1
#include <cutils/properties.h>
#include <log/log.h>
#include <netdutils/ThreadUtil.h>
#include <sysutils/SocketClient.h>
#include "Controllers.h"
#include "MDnsEventReporter.h"
#include "netid_client.h"
using android::net::gCtls;
#define MDNS_SERVICE_NAME "mdnsd"
#define MDNS_SERVICE_STATUS "init.svc.mdnsd"
#define CEIL(x, y) (((x) + (y) - 1) / (y))
constexpr char RESCAN[] = "1";
using android::net::mdns::aidl::DiscoveryInfo;
using android::net::mdns::aidl::GetAddressInfo;
using android::net::mdns::aidl::IMDnsEventListener;
using android::net::mdns::aidl::RegistrationInfo;
using android::net::mdns::aidl::ResolutionInfo;
static unsigned ifaceIndexToNetId(uint32_t interfaceIndex) {
char interfaceName[IFNAMSIZ] = {};
unsigned netId;
if (if_indextoname(interfaceIndex, interfaceName) == nullptr) {
ALOGE("Interface %d was not found", interfaceIndex);
return NETID_UNSET;
} else if ((netId = gCtls->netCtrl.getNetworkForInterface(interfaceName)) == NETID_UNSET) {
ALOGE("Network was not found for interface %s", interfaceName);
return NETID_UNSET;
}
return netId;
}
int MDnsSdListener::discover(uint32_t ifIndex, const char* regType, const char* domain,
const int requestId, const int requestFlags) {
if (VDBG) {
ALOGD("discover(%d, %s, %s, %d, %d)", ifIndex, regType, domain ? domain : "null", requestId,
requestFlags);
}
Context* context = new Context(requestId);
DNSServiceRef* ref = mMonitor.allocateServiceRef(requestId, context);
if (ref == nullptr) {
ALOGE("requestId %d already in use during discover call", requestId);
return -EBUSY;
}
if (VDBG) ALOGD("using ref %p", ref);
DNSServiceErrorType result = DNSServiceBrowse(ref, requestFlags, ifIndex, regType, domain,
&MDnsSdListenerDiscoverCallback, context);
if (result != kDNSServiceErr_NoError) {
ALOGE("Discover request %d got an error from DNSServiceBrowse %d", requestId, result);
mMonitor.freeServiceRef(requestId);
// Return kDNSServiceErr_* directly instead of transferring to an UNIX error.
// This can help caller to know what going wrong from mdnsresponder side.
return -result;
}
mMonitor.startMonitoring(requestId);
if (VDBG) ALOGD("discover successful");
return 0;
}
void MDnsSdListenerDiscoverCallback(DNSServiceRef /* sdRef */, DNSServiceFlags flags,
uint32_t ifIndex, DNSServiceErrorType errorCode,
const char* serviceName, const char* regType,
const char* replyDomain, void* inContext) {
MDnsSdListener::Context *context = reinterpret_cast<MDnsSdListener::Context *>(inContext);
int refNumber = context->mRefNumber;
const auto& listeners = MDnsEventReporter::getInstance().getEventListeners();
if (listeners.empty()) {
ALOGI("Discover callback not sent since no IMDnsEventListener receiver is available.");
return;
}
DiscoveryInfo info;
info.id = refNumber;
info.serviceName = serviceName;
info.registrationType = regType;
info.interfaceIdx = ifIndex;
// If the network is not found, still send the event and let
// the service decide what to do with a callback with an empty network
info.netId = ifaceIndexToNetId(ifIndex);
if (errorCode == kDNSServiceErr_NoError) {
if (flags & kDNSServiceFlagsAdd) {
if (VDBG) {
ALOGD("Discover found new serviceName %s, regType %s and domain %s for %d",
serviceName, regType, replyDomain, refNumber);
}
info.result = IMDnsEventListener::SERVICE_FOUND;
} else {
if (VDBG) {
ALOGD("Discover lost serviceName %s, regType %s and domain %s for %d", serviceName,
regType, replyDomain, refNumber);
}
info.result = IMDnsEventListener::SERVICE_LOST;
}
} else {
if (DBG) ALOGE("discover failure for %d, error= %d", refNumber, errorCode);
info.result = IMDnsEventListener::SERVICE_DISCOVERY_FAILED;
}
for (const auto& it : listeners) {
it->getListener()->onServiceDiscoveryStatus(info);
}
}
int MDnsSdListener::stop(int requestId) {
DNSServiceRef* ref = mMonitor.lookupServiceRef(requestId);
if (ref == nullptr) {
if (DBG) ALOGE("Stop used unknown requestId %d", requestId);
return -ESRCH;
}
if (VDBG) ALOGD("Stopping operation with ref %p", ref);
mMonitor.deallocateServiceRef(ref);
mMonitor.freeServiceRef(requestId);
return 0;
}
int MDnsSdListener::serviceRegister(int requestId, const char* serviceName, const char* serviceType,
const char* domain, const char* host, int port,
const std::vector<unsigned char>& txtRecord, uint32_t ifIndex) {
if (VDBG) {
ALOGD("serviceRegister(%d, %d, %s, %s, %s, %s, %d, <binary>)", requestId, ifIndex,
serviceName, serviceType, domain ? domain : "null", host ? host : "null", port);
}
Context* context = new Context(requestId);
DNSServiceRef* ref = mMonitor.allocateServiceRef(requestId, context);
if (ref == nullptr) {
ALOGE("requestId %d already in use during register call", requestId);
return -EBUSY;
}
port = htons(port);
DNSServiceFlags nativeFlags = 0;
DNSServiceErrorType result = DNSServiceRegister(
ref, nativeFlags, ifIndex, serviceName, serviceType, domain, host, port,
txtRecord.size(), &txtRecord.front(), &MDnsSdListenerRegisterCallback, context);
if (result != kDNSServiceErr_NoError) {
ALOGE("service register request %d got an error from DNSServiceRegister %d", requestId,
result);
mMonitor.freeServiceRef(requestId);
// Return kDNSServiceErr_* directly instead of transferring to an UNIX error.
// This can help caller to know what going wrong from mdnsresponder side.
return -result;
}
mMonitor.startMonitoring(requestId);
if (VDBG) ALOGD("serviceRegister successful");
return 0;
}
void MDnsSdListenerRegisterCallback(DNSServiceRef /* sdRef */, DNSServiceFlags /* flags */,
DNSServiceErrorType errorCode, const char* serviceName,
const char* regType, const char* /* domain */,
void* inContext) {
MDnsSdListener::Context* context = reinterpret_cast<MDnsSdListener::Context*>(inContext);
int refNumber = context->mRefNumber;
const auto& listeners = MDnsEventReporter::getInstance().getEventListeners();
if (listeners.empty()) {
ALOGI("Register callback not sent since no IMDnsEventListener receiver is available.");
return;
}
RegistrationInfo info;
info.id = refNumber;
info.serviceName = serviceName;
info.registrationType = regType;
if (errorCode == kDNSServiceErr_NoError) {
if (VDBG) ALOGD("register succeeded for %d as %s", refNumber, serviceName);
info.result = IMDnsEventListener::SERVICE_REGISTERED;
} else {
if (DBG) ALOGE("register failure for %d, error= %d", refNumber, errorCode);
info.result = IMDnsEventListener::SERVICE_REGISTRATION_FAILED;
}
for (const auto& it : listeners) {
it->getListener()->onServiceRegistrationStatus(info);
}
}
int MDnsSdListener::resolveService(int requestId, uint32_t ifIndex, const char* serviceName,
const char* regType, const char* domain) {
if (VDBG) {
ALOGD("resolveService(%d, %d, %s, %s, %s)", requestId, ifIndex, serviceName, regType,
domain);
}
Context* context = new Context(requestId);
DNSServiceRef* ref = mMonitor.allocateServiceRef(requestId, context);
if (ref == nullptr) {
ALOGE("request Id %d already in use during resolve call", requestId);
return -EBUSY;
}
DNSServiceFlags nativeFlags = 0;
DNSServiceErrorType result = DNSServiceResolve(ref, nativeFlags, ifIndex, serviceName, regType,
domain, &MDnsSdListenerResolveCallback, context);
if (result != kDNSServiceErr_NoError) {
ALOGE("service resolve request %d on iface %d: got an error from DNSServiceResolve %d",
requestId, ifIndex, result);
mMonitor.freeServiceRef(requestId);
// Return kDNSServiceErr_* directly instead of transferring to an UNIX error.
// This can help caller to know what going wrong from mdnsresponder side.
return -result;
}
mMonitor.startMonitoring(requestId);
if (VDBG) ALOGD("resolveService successful");
return 0;
}
void MDnsSdListenerResolveCallback(DNSServiceRef /* sdRef */, DNSServiceFlags /* flags */,
uint32_t ifIndex, DNSServiceErrorType errorCode,
const char* fullname, const char* hosttarget, uint16_t port,
uint16_t txtLen, const unsigned char* txtRecord,
void* inContext) {
MDnsSdListener::Context* context = reinterpret_cast<MDnsSdListener::Context*>(inContext);
int refNumber = context->mRefNumber;
const auto& listeners = MDnsEventReporter::getInstance().getEventListeners();
if (listeners.empty()) {
ALOGI("Resolve callback not sent since no IMDnsEventListener receiver is available.");
return;
}
port = ntohs(port);
ResolutionInfo info;
info.id = refNumber;
info.port = port;
info.serviceFullName = fullname;
info.hostname = hosttarget;
info.txtRecord = std::vector<unsigned char>(txtRecord, txtRecord + txtLen);
info.interfaceIdx = ifIndex;
if (errorCode == kDNSServiceErr_NoError) {
if (VDBG) {
ALOGD("resolve succeeded for %d finding %s at %s:%d with txtLen %d", refNumber,
fullname, hosttarget, port, txtLen);
}
info.result = IMDnsEventListener::SERVICE_RESOLVED;
} else {
if (DBG) ALOGE("resolve failure for %d, error= %d", refNumber, errorCode);
info.result = IMDnsEventListener::SERVICE_RESOLUTION_FAILED;
}
for (const auto& it : listeners) {
it->getListener()->onServiceResolutionStatus(info);
}
}
int MDnsSdListener::getAddrInfo(int requestId, uint32_t ifIndex, uint32_t protocol,
const char* hostname) {
if (VDBG) ALOGD("getAddrInfo(%d, %u %d, %s)", requestId, ifIndex, protocol, hostname);
Context* context = new Context(requestId);
DNSServiceRef* ref = mMonitor.allocateServiceRef(requestId, context);
if (ref == nullptr) {
ALOGE("request ID %d already in use during getAddrInfo call", requestId);
return -EBUSY;
}
DNSServiceFlags nativeFlags = 0;
DNSServiceErrorType result =
DNSServiceGetAddrInfo(ref, nativeFlags, ifIndex, protocol, hostname,
&MDnsSdListenerGetAddrInfoCallback, context);
if (result != kDNSServiceErr_NoError) {
ALOGE("getAddrInfo request %d got an error from DNSServiceGetAddrInfo %d", requestId,
result);
mMonitor.freeServiceRef(requestId);
// Return kDNSServiceErr_* directly instead of transferring to an UNIX error.
// This can help caller to know what going wrong from mdnsresponder side.
return -result;
}
mMonitor.startMonitoring(requestId);
if (VDBG) ALOGD("getAddrInfo successful");
return 0;
}
void MDnsSdListenerGetAddrInfoCallback(DNSServiceRef /* sdRef */, DNSServiceFlags /* flags */,
uint32_t ifIndex, DNSServiceErrorType errorCode,
const char* hostname, const struct sockaddr* const sa,
uint32_t /* ttl */, void* inContext) {
MDnsSdListener::Context *context = reinterpret_cast<MDnsSdListener::Context *>(inContext);
int refNumber = context->mRefNumber;
const auto& listeners = MDnsEventReporter::getInstance().getEventListeners();
if (listeners.empty()) {
ALOGI("Get address callback not sent since no IMDnsEventListener receiver is available.");
return;
}
GetAddressInfo info;
info.id = refNumber;
info.hostname = hostname;
info.interfaceIdx = ifIndex;
// If the network is not found, still send the event with an empty network
// and let the service decide what to do with it
info.netId = ifaceIndexToNetId(ifIndex);
if (errorCode == kDNSServiceErr_NoError) {
char addr[INET6_ADDRSTRLEN];
if (sa->sa_family == AF_INET) {
inet_ntop(sa->sa_family, &(((struct sockaddr_in *)sa)->sin_addr), addr, sizeof(addr));
} else {
inet_ntop(sa->sa_family, &(((struct sockaddr_in6 *)sa)->sin6_addr), addr, sizeof(addr));
}
info.address = addr;
if (VDBG) {
ALOGD("getAddrInfo succeeded for %d:", refNumber);
}
info.result = IMDnsEventListener::SERVICE_GET_ADDR_SUCCESS;
} else {
if (DBG) ALOGE("getAddrInfo failure for %d, error= %d", refNumber, errorCode);
info.result = IMDnsEventListener::SERVICE_GET_ADDR_FAILED;
}
for (const auto& it : listeners) {
it->getListener()->onGettingServiceAddressStatus(info);
}
}
int MDnsSdListener::startDaemon() {
if (!mMonitor.startService()) {
ALOGE("Failed to start: Service already running");
return -EBUSY;
}
return 0;
}
int MDnsSdListener::stopDaemon() {
if (!mMonitor.stopService()) {
ALOGE("Failed to stop: Service still in use");
return -EBUSY;
}
return 0;
}
MDnsSdListener::Monitor::Monitor() {
mHead = nullptr;
mLiveCount = 0;
mPollFds = nullptr;
mPollRefs = nullptr;
mPollSize = 10;
socketpair(AF_LOCAL, SOCK_STREAM | SOCK_CLOEXEC, 0, mCtrlSocketPair);
const int rval = ::android::netdutils::threadLaunch(this);
if (rval != 0) {
ALOGW("Error spawning monitor thread: %s (%d)", strerror(-rval), -rval);
}
}
#define NAP_TIME 200 // 200 ms between polls
static int wait_for_property(const char *name, const char *desired_value, int maxwait)
{
char value[PROPERTY_VALUE_MAX] = {'\0'};
int maxnaps = (maxwait * 1000) / NAP_TIME;
if (maxnaps < 1) {
maxnaps = 1;
}
while (maxnaps-- > 0) {
usleep(NAP_TIME * 1000);
if (property_get(name, value, nullptr)) {
if (desired_value == nullptr || strcmp(value, desired_value) == 0) {
return 0;
}
}
}
return -1; /* failure */
}
int MDnsSdListener::Monitor::startService() {
char property_value[PROPERTY_VALUE_MAX];
std::lock_guard guard(mMutex);
property_get(MDNS_SERVICE_STATUS, property_value, "");
if (strcmp("running", property_value) != 0) {
ALOGD("Starting MDNSD");
property_set("ctl.start", MDNS_SERVICE_NAME);
wait_for_property(MDNS_SERVICE_STATUS, "running", 5);
return -1;
}
return 0;
}
int MDnsSdListener::Monitor::stopService() {
std::lock_guard guard(mMutex);
if (mHead == nullptr) {
ALOGD("Stopping MDNSD");
property_set("ctl.stop", MDNS_SERVICE_NAME);
wait_for_property(MDNS_SERVICE_STATUS, "stopped", 5);
return -1;
}
return 0;
}
void MDnsSdListener::Monitor::run() {
int pollCount = 1;
mPollFds = (struct pollfd *)calloc(sizeof(struct pollfd), mPollSize);
mPollRefs = (DNSServiceRef **)calloc(sizeof(DNSServiceRef *), mPollSize);
LOG_ALWAYS_FATAL_IF((mPollFds == nullptr), "initial calloc failed on mPollFds with a size of %d",
((int)sizeof(struct pollfd)) * mPollSize);
LOG_ALWAYS_FATAL_IF((mPollRefs == nullptr), "initial calloc failed on mPollRefs with a size of %d",
((int)sizeof(DNSServiceRef *)) * mPollSize);
mPollFds[0].fd = mCtrlSocketPair[0];
mPollFds[0].events = POLLIN;
if (VDBG) ALOGD("MDnsSdListener starting to monitor");
while (1) {
if (VDBG) ALOGD("Going to poll with pollCount %d", pollCount);
int pollResults = poll(mPollFds, pollCount, 10000000);
if (VDBG) ALOGD("pollResults=%d", pollResults);
if (pollResults < 0) {
ALOGE("Error in poll - got %d", errno);
} else if (pollResults > 0) {
if (VDBG) ALOGD("Monitor poll got data pollCount = %d, %d", pollCount, pollResults);
for(int i = 1; i < pollCount; i++) {
if (mPollFds[i].revents != 0) {
if (VDBG) {
ALOGD("Monitor found [%d].revents = %d - calling ProcessResults",
i, mPollFds[i].revents);
}
std::lock_guard guard(mMutex);
DNSServiceProcessResult(*(mPollRefs[i]));
mPollFds[i].revents = 0;
}
}
if (VDBG) ALOGD("controlSocket shows revent= %d", mPollFds[0].revents);
switch (mPollFds[0].revents) {
case POLLIN: {
char readBuf[2];
read(mCtrlSocketPair[0], &readBuf, 1);
if (DBG) ALOGD("MDnsSdListener::Monitor got %c", readBuf[0]);
if (memcmp(RESCAN, readBuf, 1) == 0) {
pollCount = rescan();
}
}
}
mPollFds[0].revents = 0;
} else {
if (VDBG) ALOGD("MDnsSdListener::Monitor poll timed out");
}
}
free(mPollFds);
free(mPollRefs);
}
#define DBG_RESCAN 0
int MDnsSdListener::Monitor::rescan() {
// rescan the list from mHead and make new pollfds and serviceRefs
if (VDBG) {
ALOGD("MDnsSdListener::Monitor poll rescanning - size=%d, live=%d", mPollSize, mLiveCount);
}
std::lock_guard guard(mMutex);
Element **prevPtr = &mHead;
int i = 1;
if (mPollSize <= mLiveCount) {
mPollSize = mLiveCount + 5;
free(mPollFds);
free(mPollRefs);
mPollFds = (struct pollfd *)calloc(sizeof(struct pollfd), mPollSize);
mPollRefs = (DNSServiceRef **)calloc(sizeof(DNSServiceRef *), mPollSize);
LOG_ALWAYS_FATAL_IF((mPollFds == nullptr), "calloc failed on mPollFds with a size of %d",
((int)sizeof(struct pollfd)) * mPollSize);
LOG_ALWAYS_FATAL_IF((mPollRefs == nullptr), "calloc failed on mPollRefs with a size of %d",
((int)sizeof(DNSServiceRef *)) * mPollSize);
} else {
memset(mPollFds, 0, sizeof(struct pollfd) * mPollSize);
memset(mPollRefs, 0, sizeof(DNSServiceRef *) * mPollSize);
}
mPollFds[0].fd = mCtrlSocketPair[0];
mPollFds[0].events = POLLIN;
if (DBG_RESCAN) ALOGD("mHead = %p", mHead);
while (*prevPtr != nullptr) {
if (DBG_RESCAN) ALOGD("checking %p, mReady = %d", *prevPtr, (*prevPtr)->mReady);
if ((*prevPtr)->mReady == 1) {
int fd = DNSServiceRefSockFD((*prevPtr)->mRef);
if (fd != -1) {
if (DBG_RESCAN) ALOGD(" adding FD %d", fd);
mPollFds[i].fd = fd;
mPollFds[i].events = POLLIN;
mPollRefs[i] = &((*prevPtr)->mRef);
i++;
} else {
ALOGE("Error retreving socket FD for live ServiceRef");
}
prevPtr = &((*prevPtr)->mNext); // advance to the next element
} else if ((*prevPtr)->mReady == -1) {
if (DBG_RESCAN) ALOGD(" removing %p from play", *prevPtr);
Element *cur = *prevPtr;
*prevPtr = (cur)->mNext; // change our notion of this element and don't advance
delete cur;
} else if ((*prevPtr)->mReady == 0) {
// Not ready so just skip this node and continue on
if (DBG_RESCAN) ALOGD("%p not ready. Continuing.", *prevPtr);
prevPtr = &((*prevPtr)->mNext);
}
}
return i;
}
DNSServiceRef *MDnsSdListener::Monitor::allocateServiceRef(int id, Context *context) {
if (lookupServiceRef(id) != nullptr) {
delete(context);
return nullptr;
}
Element *e = new Element(id, context);
std::lock_guard guard(mMutex);
e->mNext = mHead;
mHead = e;
return &(e->mRef);
}
DNSServiceRef *MDnsSdListener::Monitor::lookupServiceRef(int id) {
std::lock_guard guard(mMutex);
Element *cur = mHead;
while (cur != nullptr) {
if (cur->mId == id) {
DNSServiceRef *result = &(cur->mRef);
return result;
}
cur = cur->mNext;
}
return nullptr;
}
void MDnsSdListener::Monitor::startMonitoring(int id) {
if (VDBG) ALOGD("startMonitoring %d", id);
std::lock_guard guard(mMutex);
for (Element* cur = mHead; cur != nullptr; cur = cur->mNext) {
if (cur->mId == id) {
if (DBG_RESCAN) ALOGD("marking %p as ready to be added", cur);
mLiveCount++;
cur->mReady = 1;
write(mCtrlSocketPair[1], RESCAN, 1); // trigger a rescan for a fresh poll
if (VDBG) ALOGD("triggering rescan");
return;
}
}
}
void MDnsSdListener::Monitor::freeServiceRef(int id) {
if (VDBG) ALOGD("freeServiceRef %d", id);
std::lock_guard guard(mMutex);
Element* cur;
for (Element** prevPtr = &mHead; *prevPtr != nullptr; prevPtr = &(cur->mNext)) {
cur = *prevPtr;
if (cur->mId == id) {
if (DBG_RESCAN) ALOGD("marking %p as ready to be removed", cur);
mLiveCount--;
if (cur->mReady == 1) {
cur->mReady = -1; // tell poll thread to delete
cur->mRef = nullptr; // do not process further results
write(mCtrlSocketPair[1], RESCAN, 1); // trigger a rescan for a fresh poll
if (VDBG) ALOGD("triggering rescan");
} else {
*prevPtr = cur->mNext;
delete cur;
}
return;
}
}
}
void MDnsSdListener::Monitor::deallocateServiceRef(DNSServiceRef* ref) {
std::lock_guard guard(mMutex);
DNSServiceRefDeallocate(*ref);
*ref = nullptr;
}