MDnsSdListener.cpp revision 4833e47bb886db80cf4ec23a00cc4ba2a1f113e7 
1/*
2 * Copyright (C) 2010 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include <arpa/inet.h>
18#include <dirent.h>
19#include <errno.h>
20#include <linux/if.h>
21#include <netdb.h>
22#include <netinet/in.h>
23#include <pthread.h>
24#include <stdlib.h>
25#include <sys/poll.h>
26#include <sys/socket.h>
27#include <sys/types.h>
28#include <string.h>
29
30#define LOG_TAG "MDnsDS"
31#define DBG 1
32#define VDBG 1
33
34#include <cutils/log.h>
35#include <cutils/properties.h>
36#include <sysutils/SocketClient.h>
37
38#include "MDnsSdListener.h"
39#include "ResponseCode.h"
40
41#define MDNS_SERVICE_NAME "mdnsd"
42#define MDNS_SERVICE_STATUS "init.svc.mdnsd"
43
44MDnsSdListener::MDnsSdListener() :
45                 FrameworkListener("mdns", true) {
46    Monitor *m = new Monitor();
47    registerCmd(new Handler(m, this));
48}
49
50MDnsSdListener::Handler::Handler(Monitor *m, MDnsSdListener *listener) :
51   NetdCommand("mdnssd") {
52   if (DBG) ALOGD("MDnsSdListener::Hander starting up");
53   mMonitor = m;
54   mListener = listener;
55}
56
57MDnsSdListener::Handler::~Handler() {}
58
59void MDnsSdListener::Handler::discover(SocketClient *cli,
60        const char *iface,
61        const char *regType,
62        const char *domain,
63        const int requestId,
64        const int requestFlags) {
65    if (VDBG) {
66        ALOGD("discover(%s, %s, %s, %d, %d)", iface, regType, domain, requestId,
67                requestFlags);
68    }
69    Context *context = new Context(requestId, mListener);
70    DNSServiceRef *ref = mMonitor->allocateServiceRef(requestId, context);
71    if (ref == NULL) {
72        ALOGE("requestId %d already in use during discover call", requestId);
73        cli->sendMsg(ResponseCode::CommandParameterError,
74                "RequestId already in use during discover call", false);
75        return;
76    }
77    if (VDBG) ALOGD("using ref %p", ref);
78    DNSServiceFlags nativeFlags = iToFlags(requestFlags);
79    int interfaceInt = ifaceNameToI(iface);
80
81    DNSServiceErrorType result = DNSServiceBrowse(ref, nativeFlags, interfaceInt, regType,
82            domain, &MDnsSdListenerDiscoverCallback, context);
83    if (result != kDNSServiceErr_NoError) {
84        ALOGE("Discover request %d got an error from DNSServiceBrowse %d", requestId, result);
85        mMonitor->freeServiceRef(requestId);
86        cli->sendMsg(ResponseCode::CommandParameterError,
87                "Discover request got an error from DNSServiceBrowse", false);
88        return;
89    }
90    mMonitor->startMonitoring(requestId);
91    if (VDBG) ALOGD("discover successful");
92    cli->sendMsg(ResponseCode::CommandOkay, "Discover operation started", false);
93    return;
94}
95
96void MDnsSdListenerDiscoverCallback(DNSServiceRef sdRef, DNSServiceFlags flags,
97        uint32_t interfaceIndex, DNSServiceErrorType errorCode, const char *serviceName,
98        const char *regType, const char *replyDomain, void *inContext) {
99    MDnsSdListener::Context *context = reinterpret_cast<MDnsSdListener::Context *>(inContext);
100    char *msg;
101    int refNumber = context->mRefNumber;
102
103    if (errorCode != kDNSServiceErr_NoError) {
104        asprintf(&msg, "%d %d", refNumber, errorCode);
105        context->mListener->sendBroadcast(ResponseCode::ServiceDiscoveryFailed, msg, false);
106        if (DBG) ALOGE("discover failure for %d, error= %d", refNumber, errorCode);
107    } else {
108        int respCode;
109        char *quotedServiceName = SocketClient::quoteArg(serviceName);
110        if (flags & kDNSServiceFlagsAdd) {
111            if (VDBG) {
112                ALOGD("Discover found new serviceName %s, regType %s and domain %s for %d",
113                        serviceName, regType, replyDomain, refNumber);
114            }
115            respCode = ResponseCode::ServiceDiscoveryServiceAdded;
116        } else {
117            if (VDBG) {
118                ALOGD("Discover lost serviceName %s, regType %s and domain %s for %d",
119                        serviceName, regType, replyDomain, refNumber);
120            }
121            respCode = ResponseCode::ServiceDiscoveryServiceRemoved;
122        }
123        asprintf(&msg, "%d %s %s %s", refNumber, quotedServiceName, regType, replyDomain);
124        free(quotedServiceName);
125        context->mListener->sendBroadcast(respCode, msg, false);
126    }
127    free(msg);
128}
129
130void MDnsSdListener::Handler::stop(SocketClient *cli, int argc, char **argv, const char *str) {
131    if (argc != 3) {
132        char *msg;
133        asprintf(&msg, "Invalid number of arguments to %s", str);
134        cli->sendMsg(ResponseCode::CommandParameterError, msg, false);
135        free(msg);
136        return;
137    }
138    int requestId = atoi(argv[2]);
139    DNSServiceRef *ref = mMonitor->lookupServiceRef(requestId);
140    if (ref == NULL) {
141        if (DBG) ALOGE("%s stop used unknown requestId %d", str, requestId);
142        cli->sendMsg(ResponseCode::CommandParameterError, "Unknown requestId", false);
143        return;
144    }
145    if (VDBG) ALOGD("Stopping %s with ref %p", str, ref);
146    DNSServiceRefDeallocate(*ref);
147    mMonitor->freeServiceRef(requestId);
148    char *msg;
149    asprintf(&msg, "%s stopped", str);
150    cli->sendMsg(ResponseCode::CommandOkay, msg, false);
151    free(msg);
152}
153
154void MDnsSdListener::Handler::serviceRegister(SocketClient *cli, int requestId,
155        const char *interfaceName, const char *serviceName, const char *serviceType,
156        const char *domain, const char *host, int port, int txtLen, void *txtRecord) {
157    if (VDBG) {
158        ALOGD("serviceRegister(%d, %s, %s, %s, %s, %s, %d, %d, <binary>)", requestId,
159                interfaceName, serviceName, serviceType, domain, host, port, txtLen);
160    }
161    Context *context = new Context(requestId, mListener);
162    DNSServiceRef *ref = mMonitor->allocateServiceRef(requestId, context);
163    port = htons(port);
164    if (ref == NULL) {
165        ALOGE("requestId %d already in use during register call", requestId);
166        cli->sendMsg(ResponseCode::CommandParameterError,
167                "RequestId already in use during register call", false);
168        return;
169    }
170    DNSServiceFlags nativeFlags = 0;
171    int interfaceInt = ifaceNameToI(interfaceName);
172    DNSServiceErrorType result = DNSServiceRegister(ref, interfaceInt, nativeFlags, serviceName,
173            serviceType, domain, host, port, txtLen, txtRecord, &MDnsSdListenerRegisterCallback,
174            context);
175    if (result != kDNSServiceErr_NoError) {
176        ALOGE("service register request %d got an error from DNSServiceRegister %d", requestId,
177                result);
178        mMonitor->freeServiceRef(requestId);
179        cli->sendMsg(ResponseCode::CommandParameterError,
180                "serviceRegister request got an error from DNSServiceRegister", false);
181        return;
182    }
183    mMonitor->startMonitoring(requestId);
184    if (VDBG) ALOGD("serviceRegister successful");
185    cli->sendMsg(ResponseCode::CommandOkay, "serviceRegister started", false);
186    return;
187}
188
189void MDnsSdListenerRegisterCallback(DNSServiceRef sdRef, DNSServiceFlags flags,
190        DNSServiceErrorType errorCode, const char *serviceName, const char *regType,
191        const char *domain, void *inContext) {
192    MDnsSdListener::Context *context = reinterpret_cast<MDnsSdListener::Context *>(inContext);
193    char *msg;
194    int refNumber = context->mRefNumber;
195    if (errorCode != kDNSServiceErr_NoError) {
196        asprintf(&msg, "%d %d", refNumber, errorCode);
197        context->mListener->sendBroadcast(ResponseCode::ServiceRegistrationFailed, msg, false);
198        if (DBG) ALOGE("register failure for %d, error= %d", refNumber, errorCode);
199    } else {
200        char *quotedServiceName = SocketClient::quoteArg(serviceName);
201        asprintf(&msg, "%d %s", refNumber, quotedServiceName);
202        free(quotedServiceName);
203        context->mListener->sendBroadcast(ResponseCode::ServiceRegistrationSucceeded, msg, false);
204        if (VDBG) ALOGD("register succeeded for %d as %s", refNumber, serviceName);
205    }
206    free(msg);
207}
208
209
210void MDnsSdListener::Handler::resolveService(SocketClient *cli, int requestId,
211        const char *interfaceName, const char *serviceName, const char *regType,
212        const char *domain) {
213    if (VDBG) {
214        ALOGD("resolveService(%d, %s, %s, %s, %s)", requestId, interfaceName,
215                serviceName, regType, domain);
216    }
217    Context *context = new Context(requestId, mListener);
218    DNSServiceRef *ref = mMonitor->allocateServiceRef(requestId, context);
219    if (ref == NULL) {
220        ALOGE("request Id %d already in use during resolve call", requestId);
221        cli->sendMsg(ResponseCode::CommandParameterError,
222                "RequestId already in use during resolve call", false);
223        return;
224    }
225    DNSServiceFlags nativeFlags = 0;
226    int interfaceInt = ifaceNameToI(interfaceName);
227    DNSServiceErrorType result = DNSServiceResolve(ref, nativeFlags, interfaceInt, serviceName,
228            regType, domain, &MDnsSdListenerResolveCallback, context);
229    if (result != kDNSServiceErr_NoError) {
230        ALOGE("service resolve request %d got an error from DNSServiceResolve %d", requestId,
231                result);
232        mMonitor->freeServiceRef(requestId);
233        cli->sendMsg(ResponseCode::CommandParameterError,
234                "resolveService got an error from DNSServiceResolve", false);
235        return;
236    }
237    mMonitor->startMonitoring(requestId);
238    if (VDBG) ALOGD("resolveService successful");
239    cli->sendMsg(ResponseCode::CommandOkay, "resolveService started", false);
240    return;
241}
242
243void MDnsSdListenerResolveCallback(DNSServiceRef sdRef, DNSServiceFlags flags, uint32_t interface,
244        DNSServiceErrorType errorCode, const char *fullname, const char *hosttarget, uint16_t port,
245        uint16_t txtLen, const unsigned char *txtRecord, void *inContext) {
246    MDnsSdListener::Context *context = reinterpret_cast<MDnsSdListener::Context *>(inContext);
247    char *msg;
248    int refNumber = context->mRefNumber;
249    port = ntohs(port);
250    if (errorCode != kDNSServiceErr_NoError) {
251        asprintf(&msg, "%d %d", refNumber, errorCode);
252        context->mListener->sendBroadcast(ResponseCode::ServiceResolveFailed, msg, false);
253        if (DBG) ALOGE("resolve failure for %d, error= %d", refNumber, errorCode);
254    } else {
255        char *quotedFullName = SocketClient::quoteArg(fullname);
256        char *quotedHostTarget = SocketClient::quoteArg(hosttarget);
257        asprintf(&msg, "%d %s %s %d %d", refNumber, quotedFullName, quotedHostTarget, port, txtLen);
258        free(quotedFullName);
259        free(quotedHostTarget);
260        context->mListener->sendBroadcast(ResponseCode::ServiceResolveSuccess, msg, false);
261        if (VDBG) {
262            ALOGD("resolve succeeded for %d finding %s at %s:%d with txtLen %d",
263                    refNumber, fullname, hosttarget, port, txtLen);
264        }
265    }
266    free(msg);
267}
268
269void MDnsSdListener::Handler::getAddrInfo(SocketClient *cli, int requestId,
270        const char *interfaceName, uint32_t protocol, const char *hostname) {
271    if (VDBG) ALOGD("getAddrInfo(%d, %s %d, %s)", requestId, interfaceName, protocol, hostname);
272    Context *context = new Context(requestId, mListener);
273    DNSServiceRef *ref = mMonitor->allocateServiceRef(requestId, context);
274    if (ref == NULL) {
275        ALOGE("request ID %d already in use during getAddrInfo call", requestId);
276        cli->sendMsg(ResponseCode::CommandParameterError,
277                "RequestId already in use during getAddrInfo call", false);
278        return;
279    }
280    DNSServiceFlags nativeFlags = 0;
281    int interfaceInt = ifaceNameToI(interfaceName);
282    DNSServiceErrorType result = DNSServiceGetAddrInfo(ref, nativeFlags, interfaceInt, protocol,
283            hostname, &MDnsSdListenerGetAddrInfoCallback, context);
284    if (result != kDNSServiceErr_NoError) {
285        ALOGE("getAddrInfo request %d got an error from DNSServiceGetAddrInfo %d", requestId,
286                result);
287        mMonitor->freeServiceRef(requestId);
288        cli->sendMsg(ResponseCode::CommandParameterError,
289                "getAddrInfo request got an error from DNSServiceGetAddrInfo", false);
290        return;
291    }
292    mMonitor->startMonitoring(requestId);
293    if (VDBG) ALOGD("getAddrInfo successful");
294    cli->sendMsg(ResponseCode::CommandOkay, "getAddrInfo started", false);
295    return;
296}
297
298void MDnsSdListenerGetAddrInfoCallback(DNSServiceRef sdRef, DNSServiceFlags flags,
299        uint32_t interface, DNSServiceErrorType errorCode, const char *hostname,
300        const struct sockaddr *const sa, uint32_t ttl, void *inContext) {
301    MDnsSdListener::Context *context = reinterpret_cast<MDnsSdListener::Context *>(inContext);
302    int refNumber = context->mRefNumber;
303
304    if (errorCode != kDNSServiceErr_NoError) {
305        char *msg;
306        asprintf(&msg, "%d %d", refNumber, errorCode);
307        context->mListener->sendBroadcast(ResponseCode::ServiceGetAddrInfoFailed, msg, false);
308        if (DBG) ALOGE("getAddrInfo failure for %d, error= %d", refNumber, errorCode);
309        free(msg);
310    } else {
311        char addr[INET6_ADDRSTRLEN];
312        char *msg;
313        char *quotedHostname = SocketClient::quoteArg(hostname);
314        if (sa->sa_family == AF_INET) {
315            inet_ntop(sa->sa_family, &(((struct sockaddr_in *)sa)->sin_addr), addr, sizeof(addr));
316        } else {
317            inet_ntop(sa->sa_family, &(((struct sockaddr_in6 *)sa)->sin6_addr), addr, sizeof(addr));
318        }
319        asprintf(&msg, "%d %s %d %s", refNumber, quotedHostname, ttl, addr);
320        free(quotedHostname);
321        context->mListener->sendBroadcast(ResponseCode::ServiceGetAddrInfoSuccess, msg, false);
322        if (VDBG) {
323            ALOGD("getAddrInfo succeeded for %d: %s", refNumber, msg);
324        }
325        free(msg);
326    }
327}
328
329void MDnsSdListener::Handler::setHostname(SocketClient *cli, int requestId,
330        const char *hostname) {
331    if (VDBG) ALOGD("setHostname(%d, %s)", requestId, hostname);
332    Context *context = new Context(requestId, mListener);
333    DNSServiceRef *ref = mMonitor->allocateServiceRef(requestId, context);
334    if (ref == NULL) {
335        ALOGE("request Id %d already in use during setHostname call", requestId);
336        cli->sendMsg(ResponseCode::CommandParameterError,
337                "RequestId already in use during setHostname call", false);
338        return;
339    }
340    DNSServiceFlags nativeFlags = 0;
341    DNSServiceErrorType result = DNSSetHostname(ref, nativeFlags, hostname,
342            &MDnsSdListenerSetHostnameCallback, context);
343    if (result != kDNSServiceErr_NoError) {
344        ALOGE("setHostname request %d got an error from DNSSetHostname %d", requestId, result);
345        mMonitor->freeServiceRef(requestId);
346        cli->sendMsg(ResponseCode::CommandParameterError,
347                "setHostname got an error from DNSSetHostname", false);
348        return;
349    }
350    mMonitor->startMonitoring(requestId);
351    if (VDBG) ALOGD("setHostname successful");
352    cli->sendMsg(ResponseCode::CommandOkay, "setHostname started", false);
353    return;
354}
355
356void MDnsSdListenerSetHostnameCallback(DNSServiceRef sdRef, DNSServiceFlags flags,
357        DNSServiceErrorType errorCode, const char *hostname, void *inContext) {
358    MDnsSdListener::Context *context = reinterpret_cast<MDnsSdListener::Context *>(inContext);
359    char *msg;
360    int refNumber = context->mRefNumber;
361    if (errorCode != kDNSServiceErr_NoError) {
362        asprintf(&msg, "%d %d", refNumber, errorCode);
363        context->mListener->sendBroadcast(ResponseCode::ServiceSetHostnameFailed, msg, false);
364        if (DBG) ALOGE("setHostname failure for %d, error= %d", refNumber, errorCode);
365    } else {
366        char *quotedHostname = SocketClient::quoteArg(hostname);
367        asprintf(&msg, "%d %s", refNumber, quotedHostname);
368        free(quotedHostname);
369        context->mListener->sendBroadcast(ResponseCode::ServiceSetHostnameSuccess, msg, false);
370        if (VDBG) ALOGD("setHostname succeeded for %d.  Set to %s", refNumber, hostname);
371    }
372    free(msg);
373}
374
375
376int MDnsSdListener::Handler::ifaceNameToI(const char *iface) {
377    return 0;
378}
379
380const char *MDnsSdListener::Handler::iToIfaceName(int i) {
381    return NULL;
382}
383
384DNSServiceFlags MDnsSdListener::Handler::iToFlags(int i) {
385    return 0;
386}
387
388int MDnsSdListener::Handler::flagsToI(DNSServiceFlags flags) {
389    return 0;
390}
391
392int MDnsSdListener::Handler::runCommand(SocketClient *cli,
393                                        int argc, char **argv) {
394    if (argc < 2) {
395        char* msg = NULL;
396        asprintf( &msg, "Invalid number of arguments to mdnssd: %i", argc);
397        ALOGW("%s", msg);
398        cli->sendMsg(ResponseCode::CommandParameterError, msg, false);
399        free(msg);
400        return -1;
401    }
402
403    char* cmd = argv[1];
404
405    if (strcmp(cmd, "discover") == 0) {
406        if (argc != 4) {
407            cli->sendMsg(ResponseCode::CommandParameterError,
408                    "Invalid number of arguments to mdnssd discover", false);
409            return 0;
410        }
411        int requestId = atoi(argv[2]);
412        char *serviceType = argv[3];
413
414        discover(cli, NULL, serviceType, NULL, requestId, 0);
415    } else if (strcmp(cmd, "stop-discover") == 0) {
416        stop(cli, argc, argv, "discover");
417    } else if (strcmp(cmd, "register") == 0) {
418        if (argc != 6) {
419            cli->sendMsg(ResponseCode::CommandParameterError,
420                    "Invalid number of arguments to mdnssd register", false);
421            return 0;
422        }
423        int requestId = atoi(argv[2]);
424        char *serviceName = argv[3];
425        char *serviceType = argv[4];
426        int port = atoi(argv[5]);
427        char *interfaceName = NULL; // will use all
428        char *domain = NULL;        // will use default
429        char *host = NULL;          // will use default hostname
430        int textLen = 0;
431        void *textRecord = NULL;
432
433        serviceRegister(cli, requestId, interfaceName, serviceName,
434                serviceType, domain, host, port, textLen, textRecord);
435    } else if (strcmp(cmd, "stop-register") == 0) {
436        stop(cli, argc, argv, "register");
437    } else if (strcmp(cmd, "resolve") == 0) {
438        if (argc != 6) {
439            cli->sendMsg(ResponseCode::CommandParameterError,
440                    "Invalid number of arguments to mdnssd resolve", false);
441            return 0;
442        }
443        int requestId = atoi(argv[2]);
444        char *interfaceName = NULL;  // will use all
445        char *serviceName = argv[3];
446        char *regType = argv[4];
447        char *domain = argv[5];
448        resolveService(cli, requestId, interfaceName, serviceName, regType, domain);
449    } else if (strcmp(cmd, "stop-resolve") == 0) {
450        stop(cli, argc, argv, "resolve");
451    } else if (strcmp(cmd, "start-service") == 0) {
452        if (mMonitor->startService()) {
453            cli->sendMsg(ResponseCode::CommandOkay, "Service Started", false);
454        } else {
455            cli->sendMsg(ResponseCode::ServiceStartFailed, "Service already running", false);
456        }
457    } else if (strcmp(cmd, "stop-service") == 0) {
458        if (mMonitor->stopService()) {
459            cli->sendMsg(ResponseCode::CommandOkay, "Service Stopped", false);
460        } else {
461            cli->sendMsg(ResponseCode::ServiceStopFailed, "Service still in use", false);
462        }
463    } else if (strcmp(cmd, "sethostname") == 0) {
464        if (argc != 4) {
465            cli->sendMsg(ResponseCode::CommandParameterError,
466                    "Invalid number of arguments to mdnssd sethostname", false);
467            return 0;
468        }
469        int requestId = atoi(argv[2]);
470        char *hostname = argv[3];
471        setHostname(cli, requestId, hostname);
472    } else if (strcmp(cmd, "stop-sethostname") == 0) {
473        stop(cli, argc, argv, "sethostname");
474    } else if (strcmp(cmd, "getaddrinfo") == 0) {
475        if (argc != 4) {
476            cli->sendMsg(ResponseCode::CommandParameterError,
477                    "Invalid number of arguments to mdnssd getaddrinfo", false);
478            return 0;
479        }
480        int requestId = atoi(argv[2]);
481        char *hostname = argv[3];
482        char *interfaceName = NULL;  // default
483        int protocol = 0;            // intelligient heuristic (both v4 + v6)
484        getAddrInfo(cli, requestId, interfaceName, protocol, hostname);
485    } else if (strcmp(cmd, "stop-getaddrinfo") == 0) {
486        stop(cli, argc, argv, "getaddrinfo");
487    } else {
488        if (VDBG) ALOGE("Unknown cmd %s", cmd);
489        cli->sendMsg(ResponseCode::CommandSyntaxError, "Unknown mdnssd cmd", false);
490        return 0;
491    }
492    return 0;
493}
494
495MDnsSdListener::Monitor::Monitor() {
496    mHead = NULL;
497    pthread_mutex_init(&mHeadMutex, NULL);
498    socketpair(AF_LOCAL, SOCK_STREAM, 0, mCtrlSocketPair);
499    pthread_create(&mThread, NULL, MDnsSdListener::Monitor::threadStart, this);
500}
501
502void *MDnsSdListener::Monitor::threadStart(void *obj) {
503    Monitor *monitor = reinterpret_cast<Monitor *>(obj);
504
505    monitor->run();
506    delete monitor;
507    pthread_exit(NULL);
508    return NULL;
509}
510
511int MDnsSdListener::Monitor::startService() {
512    int result = 0;
513    char property_value[PROPERTY_VALUE_MAX];
514    pthread_mutex_lock(&mHeadMutex);
515    property_get(MDNS_SERVICE_STATUS, property_value, "");
516    if (strcmp("running", property_value) != 0) {
517        ALOGD("Starting MDNSD");
518        property_set("ctl.start", MDNS_SERVICE_NAME);
519        wait_for_property(MDNS_SERVICE_STATUS, "running", 5);
520        result = -1;
521    } else {
522        result = 0;
523    }
524    pthread_mutex_unlock(&mHeadMutex);
525    return result;
526}
527
528int MDnsSdListener::Monitor::stopService() {
529    int result = 0;
530    pthread_mutex_lock(&mHeadMutex);
531    if (mHead == NULL) {
532        ALOGD("Stopping MDNSD");
533        property_set("ctl.stop", MDNS_SERVICE_NAME);
534        wait_for_property(MDNS_SERVICE_STATUS, "stopped", 5);
535        result = -1;
536    } else {
537        result = 0;
538    }
539    pthread_mutex_unlock(&mHeadMutex);
540    return result;
541}
542
543void MDnsSdListener::Monitor::run() {
544    int pollCount = 1;
545    mPollSize = 10;
546
547    mPollFds = (struct pollfd *)calloc(sizeof(struct pollfd), mPollSize);
548    mPollRefs = (DNSServiceRef **)calloc(sizeof(DNSServiceRef *), mPollSize);
549
550    mPollFds[0].fd = mCtrlSocketPair[0];
551    mPollFds[0].events = POLLIN;
552
553    if (VDBG) ALOGD("MDnsSdListener starting to monitor");
554    while (1) {
555        if (VDBG) ALOGD("Going to poll with pollCount %d", pollCount);
556        int pollResults = poll(mPollFds, pollCount, 10000000);
557        if (pollResults < 0) {
558            ALOGE("Error in poll - got %d", errno);
559        } else if (pollResults > 0) {
560            if (VDBG) ALOGD("Monitor poll got data pollCount = %d, %d", pollCount, pollResults);
561            for(int i = 1; i < pollCount; i++) {
562                if (mPollFds[i].revents != 0) {
563                    if (VDBG) {
564                        ALOGD("Monitor found [%d].revents = %d - calling ProcessResults",
565                                i, mPollFds[i].revents);
566                    }
567                    DNSServiceProcessResult(*(mPollRefs[i]));
568                    mPollFds[i].revents = 0;
569                }
570            }
571            if (VDBG) ALOGD("controlSocket shows revent= %d", mPollFds[0].revents);
572            switch (mPollFds[0].revents) {
573                case POLLIN: {
574                    char readBuf[2];
575                    read(mCtrlSocketPair[0], &readBuf, 1);
576                    if (DBG) ALOGD("MDnsSdListener::Monitor got %c", readBuf[0]);
577                    if (memcmp(RESCAN, readBuf, 1) == 0) {
578                        pollCount = rescan();
579                    }
580                }
581            }
582            mPollFds[0].revents = 0;
583        } else {
584            if (VDBG) ALOGD("MDnsSdListener::Monitor poll timed out");
585        }
586    }
587    free(mPollFds);
588    free(mPollRefs);
589}
590
591#define DBG_RESCAN 0
592
593int MDnsSdListener::Monitor::rescan() {
594// rescan the list from mHead and make new pollfds and serviceRefs
595    if (VDBG) {
596        ALOGD("MDnsSdListener::Monitor poll rescanning - size=%d, live=%d", mPollSize, mLiveCount);
597    }
598    int count = 0;
599    pthread_mutex_lock(&mHeadMutex);
600    Element **prevPtr = &mHead;
601    int i = 1;
602    if (mPollSize <= mLiveCount) {
603        mPollSize = mLiveCount + 5;
604        free(mPollFds);
605        free(mPollRefs);
606        mPollFds = (struct pollfd *)calloc(sizeof(struct pollfd), mPollSize);
607        mPollRefs = (DNSServiceRef **)calloc(sizeof(DNSServiceRef *), mPollSize);
608    } else {
609        memset(mPollFds, sizeof(struct pollfd) * mPollSize, 0);
610        memset(mPollRefs, sizeof(DNSServiceRef *) * mPollSize, 0);
611    }
612    mPollFds[0].fd = mCtrlSocketPair[0];
613    mPollFds[0].events = POLLIN;
614    if (DBG_RESCAN) ALOGD("mHead = %p", mHead);
615    while (*prevPtr != NULL) {
616        if (DBG_RESCAN) ALOGD("checking %p, mReady = %d", *prevPtr, (*prevPtr)->mReady);
617        if ((*prevPtr)->mReady == 1) {
618            int fd = DNSServiceRefSockFD((*prevPtr)->mRef);
619            if (fd != -1) {
620                if (DBG_RESCAN) ALOGD("  adding FD %d", fd);
621                mPollFds[i].fd = fd;
622                mPollFds[i].events = POLLIN;
623                mPollRefs[i] = &((*prevPtr)->mRef);
624                i++;
625            } else {
626                ALOGE("Error retreving socket FD for live ServiceRef");
627            }
628            prevPtr = &((*prevPtr)->mNext); // advance to the next element
629        } else if ((*prevPtr)->mReady == -1) {
630            if (DBG_RESCAN) ALOGD("  removing %p from  play", *prevPtr);
631            Element *cur = *prevPtr;
632            *prevPtr = (cur)->mNext; // change our notion of this element and don't advance
633            delete cur;
634        }
635    }
636    pthread_mutex_unlock(&mHeadMutex);
637    return i;
638}
639
640DNSServiceRef *MDnsSdListener::Monitor::allocateServiceRef(int id, Context *context) {
641    if (lookupServiceRef(id) != NULL) {
642        delete(context);
643        return NULL;
644    }
645    Element *e = new Element(id, context);
646    pthread_mutex_lock(&mHeadMutex);
647    e->mNext = mHead;
648    mHead = e;
649    pthread_mutex_unlock(&mHeadMutex);
650    return &(e->mRef);
651}
652
653DNSServiceRef *MDnsSdListener::Monitor::lookupServiceRef(int id) {
654    pthread_mutex_lock(&mHeadMutex);
655    Element *cur = mHead;
656    while (cur != NULL) {
657        if (cur->mId == id) {
658            DNSServiceRef *result = &(cur->mRef);
659            pthread_mutex_unlock(&mHeadMutex);
660            return result;
661        }
662        cur = cur->mNext;
663    }
664    pthread_mutex_unlock(&mHeadMutex);
665    return NULL;
666}
667
668void MDnsSdListener::Monitor::startMonitoring(int id) {
669    if (VDBG) ALOGD("startMonitoring %d", id);
670    pthread_mutex_lock(&mHeadMutex);
671    Element *cur = mHead;
672    while (cur != NULL) {
673        if (cur->mId == id) {
674            if (DBG_RESCAN) ALOGD("marking %p as ready to be added", cur);
675            mLiveCount++;
676            cur->mReady = 1;
677            pthread_mutex_unlock(&mHeadMutex);
678            write(mCtrlSocketPair[1], RESCAN, 1);  // trigger a rescan for a fresh poll
679            if (VDBG) ALOGD("triggering rescan");
680            return;
681        }
682        cur = cur->mNext;
683    }
684    pthread_mutex_unlock(&mHeadMutex);
685}
686
687#define NAP_TIME 200  // 200 ms between polls
688static int wait_for_property(const char *name, const char *desired_value, int maxwait)
689{
690    char value[PROPERTY_VALUE_MAX] = {'\0'};
691    int maxnaps = (maxwait * 1000) / NAP_TIME;
692
693    if (maxnaps < 1) {
694        maxnaps = 1;
695    }
696
697    while (maxnaps-- > 0) {
698        usleep(NAP_TIME * 1000);
699        if (property_get(name, value, NULL)) {
700            if (desired_value == NULL || strcmp(value, desired_value) == 0) {
701                return 0;
702            }
703        }
704    }
705    return -1; /* failure */
706}
707
708void MDnsSdListener::Monitor::freeServiceRef(int id) {
709    if (VDBG) ALOGD("freeServiceRef %d", id);
710    pthread_mutex_lock(&mHeadMutex);
711    Element **prevPtr = &mHead;
712    Element *cur;
713    while (*prevPtr != NULL) {
714        cur = *prevPtr;
715        if (cur->mId == id) {
716            if (DBG_RESCAN) ALOGD("marking %p as ready to be removed", cur);
717            mLiveCount--;
718            if (cur->mReady == 1) {
719                cur->mReady = -1; // tell poll thread to delete
720                write(mCtrlSocketPair[1], RESCAN, 1); // trigger a rescan for a fresh poll
721                if (VDBG) ALOGD("triggering rescan");
722            } else {
723                *prevPtr = cur->mNext;
724                delete cur;
725            }
726            pthread_mutex_unlock(&mHeadMutex);
727            return;
728        }
729        prevPtr = &(cur->mNext);
730    }
731    pthread_mutex_unlock(&mHeadMutex);
732}
733