1 /* -*- Mode: C; tab-width: 4 -*-
2 *
3 * Copyright (c) 2002-2004 Apple Computer, Inc. All rights reserved.
4 *
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 *
17 */
18
19 #include "mDNSEmbeddedAPI.h" // Defines the interface provided to the client layer above
20 #include "DNSCommon.h"
21 #include "mDNSPosix.h" // Defines the specific types needed to run mDNS on this platform
22 #include "dns_sd.h"
23 #include "dnssec.h"
24 #include "nsec.h"
25
26 #include <assert.h>
27 #include <stdio.h>
28 #include <stdlib.h>
29 #include <errno.h>
30 #include <string.h>
31 #include <unistd.h>
32 #include <syslog.h>
33 #include <stdarg.h>
34 #include <fcntl.h>
35 #include <sys/types.h>
36 #include <sys/time.h>
37 #include <sys/socket.h>
38 #include <sys/uio.h>
39 #include <sys/select.h>
40 #include <netinet/in.h>
41 #include <arpa/inet.h>
42 #include <time.h> // platform support for UTC time
43
44 #if USES_NETLINK
45 #include <asm/types.h>
46 #include <linux/netlink.h>
47 #include <linux/rtnetlink.h>
48 #else // USES_NETLINK
49 #include <net/route.h>
50 #include <net/if.h>
51 #endif // USES_NETLINK
52
53 #include "mDNSUNP.h"
54 #include "GenLinkedList.h"
55
56 // ***************************************************************************
57 // Structures
58
59 // We keep a list of client-supplied event sources in PosixEventSource records
60 struct PosixEventSource
61 {
62 mDNSPosixEventCallback Callback;
63 void *Context;
64 int fd;
65 struct PosixEventSource *Next;
66 };
67 typedef struct PosixEventSource PosixEventSource;
68
69 // Context record for interface change callback
70 struct IfChangeRec
71 {
72 int NotifySD;
73 mDNS *mDNS;
74 };
75 typedef struct IfChangeRec IfChangeRec;
76
77 // Note that static data is initialized to zero in (modern) C.
78 static fd_set gEventFDs;
79 static int gMaxFD; // largest fd in gEventFDs
80 static GenLinkedList gEventSources; // linked list of PosixEventSource's
81 static sigset_t gEventSignalSet; // Signals which event loop listens for
82 static sigset_t gEventSignals; // Signals which were received while inside loop
83
84 static PosixNetworkInterface *gRecentInterfaces;
85
86 // ***************************************************************************
87 // Globals (for debugging)
88
89 static int num_registered_interfaces = 0;
90 static int num_pkts_accepted = 0;
91 static int num_pkts_rejected = 0;
92
93 // ***************************************************************************
94 // Functions
95
96 int gMDNSPlatformPosixVerboseLevel = 0;
97
98 #define PosixErrorToStatus(errNum) ((errNum) == 0 ? mStatus_NoError : mStatus_UnknownErr)
99
SockAddrTomDNSAddr(const struct sockaddr * const sa,mDNSAddr * ipAddr,mDNSIPPort * ipPort)100 mDNSlocal void SockAddrTomDNSAddr(const struct sockaddr *const sa, mDNSAddr *ipAddr, mDNSIPPort *ipPort)
101 {
102 switch (sa->sa_family)
103 {
104 case AF_INET:
105 {
106 struct sockaddr_in *sin = (struct sockaddr_in*)sa;
107 ipAddr->type = mDNSAddrType_IPv4;
108 ipAddr->ip.v4.NotAnInteger = sin->sin_addr.s_addr;
109 if (ipPort) ipPort->NotAnInteger = sin->sin_port;
110 break;
111 }
112
113 #if HAVE_IPV6
114 case AF_INET6:
115 {
116 struct sockaddr_in6 *sin6 = (struct sockaddr_in6*)sa;
117 #ifndef NOT_HAVE_SA_LEN
118 assert(sin6->sin6_len == sizeof(*sin6));
119 #endif
120 ipAddr->type = mDNSAddrType_IPv6;
121 ipAddr->ip.v6 = *(mDNSv6Addr*)&sin6->sin6_addr;
122 if (ipPort) ipPort->NotAnInteger = sin6->sin6_port;
123 break;
124 }
125 #endif
126
127 default:
128 verbosedebugf("SockAddrTomDNSAddr: Uknown address family %d\n", sa->sa_family);
129 ipAddr->type = mDNSAddrType_None;
130 if (ipPort) ipPort->NotAnInteger = 0;
131 break;
132 }
133 }
134
135 /*
136 * Apple source is using this to set mobile platform
137 * specific options.
138 */
139 /*ARGSUSED*/
mDNSPlatformSetuDNSSocktOpt(UDPSocket * src,const mDNSAddr * dst,DNSQuestion * q)140 mDNSexport void mDNSPlatformSetuDNSSocktOpt(UDPSocket *src, const mDNSAddr *dst, DNSQuestion *q)
141 {
142 (void)src; /* unused */
143 (void)dst; /* unused */
144 (void)q; /* unused */
145 }
146
147 #if COMPILER_LIKES_PRAGMA_MARK
148 #pragma mark ***** Send and Receive
149 #endif
150
151 // mDNS core calls this routine when it needs to send a packet.
mDNSPlatformSendUDP(const mDNS * const m,const void * const msg,const mDNSu8 * const end,mDNSInterfaceID InterfaceID,UDPSocket * src,const mDNSAddr * dst,mDNSIPPort dstPort,mDNSBool useBackgroundTrafficClass)152 mDNSexport mStatus mDNSPlatformSendUDP(const mDNS *const m, const void *const msg, const mDNSu8 *const end,
153 mDNSInterfaceID InterfaceID, UDPSocket *src, const mDNSAddr *dst,
154 mDNSIPPort dstPort, mDNSBool useBackgroundTrafficClass)
155 {
156 int err = 0;
157 struct sockaddr_storage to;
158 PosixNetworkInterface * thisIntf = (PosixNetworkInterface *)(InterfaceID);
159 int sendingsocket = -1;
160
161 (void)src; // Will need to use this parameter once we implement mDNSPlatformUDPSocket/mDNSPlatformUDPClose
162 (void) useBackgroundTrafficClass;
163
164 assert(m != NULL);
165 assert(msg != NULL);
166 assert(end != NULL);
167 assert((((char *) end) - ((char *) msg)) > 0);
168
169 if (dstPort.NotAnInteger == 0)
170 {
171 LogMsg("mDNSPlatformSendUDP: Invalid argument -dstPort is set to 0");
172 return PosixErrorToStatus(EINVAL);
173 }
174 if (dst->type == mDNSAddrType_IPv4)
175 {
176 struct sockaddr_in *sin = (struct sockaddr_in*)&to;
177 #ifndef NOT_HAVE_SA_LEN
178 sin->sin_len = sizeof(*sin);
179 #endif
180 sin->sin_family = AF_INET;
181 sin->sin_port = dstPort.NotAnInteger;
182 sin->sin_addr.s_addr = dst->ip.v4.NotAnInteger;
183 sendingsocket = thisIntf ? thisIntf->multicastSocket4 : m->p->unicastSocket4;
184 }
185
186 #if HAVE_IPV6
187 else if (dst->type == mDNSAddrType_IPv6)
188 {
189 struct sockaddr_in6 *sin6 = (struct sockaddr_in6*)&to;
190 mDNSPlatformMemZero(sin6, sizeof(*sin6));
191 #ifndef NOT_HAVE_SA_LEN
192 sin6->sin6_len = sizeof(*sin6);
193 #endif
194 sin6->sin6_family = AF_INET6;
195 sin6->sin6_port = dstPort.NotAnInteger;
196 sin6->sin6_addr = *(struct in6_addr*)&dst->ip.v6;
197 sendingsocket = thisIntf ? thisIntf->multicastSocket6 : m->p->unicastSocket6;
198 }
199 #endif
200
201 if (sendingsocket >= 0)
202 err = sendto(sendingsocket, msg, (char*)end - (char*)msg, 0, (struct sockaddr *)&to, GET_SA_LEN(to));
203
204 if (err > 0) err = 0;
205 else if (err < 0)
206 {
207 static int MessageCount = 0;
208 // Don't report EHOSTDOWN (i.e. ARP failure), ENETDOWN, or no route to host for unicast destinations
209 if (!mDNSAddressIsAllDNSLinkGroup(dst))
210 if (errno == EHOSTDOWN || errno == ENETDOWN || errno == EHOSTUNREACH || errno == ENETUNREACH) return(mStatus_TransientErr);
211
212 /* dont report ENETUNREACH */
213 if (errno == ENETUNREACH) return(mStatus_TransientErr);
214
215 if (MessageCount < 1000)
216 {
217 MessageCount++;
218 if (thisIntf)
219 LogMsg("mDNSPlatformSendUDP got error %d (%s) sending packet to %#a on interface %#a/%s/%d",
220 errno, strerror(errno), dst, &thisIntf->coreIntf.ip, thisIntf->intfName, thisIntf->index);
221 else
222 LogMsg("mDNSPlatformSendUDP got error %d (%s) sending packet to %#a", errno, strerror(errno), dst);
223 }
224 }
225
226 return PosixErrorToStatus(err);
227 }
228
229 // This routine is called when the main loop detects that data is available on a socket.
SocketDataReady(mDNS * const m,PosixNetworkInterface * intf,int skt)230 mDNSlocal void SocketDataReady(mDNS *const m, PosixNetworkInterface *intf, int skt)
231 {
232 mDNSAddr senderAddr, destAddr;
233 mDNSIPPort senderPort;
234 ssize_t packetLen;
235 DNSMessage packet;
236 struct my_in_pktinfo packetInfo;
237 struct sockaddr_storage from;
238 socklen_t fromLen;
239 int flags;
240 mDNSu8 ttl;
241 mDNSBool reject;
242 const mDNSInterfaceID InterfaceID = intf ? intf->coreIntf.InterfaceID : NULL;
243
244 assert(m != NULL);
245 assert(skt >= 0);
246
247 fromLen = sizeof(from);
248 flags = 0;
249 packetLen = recvfrom_flags(skt, &packet, sizeof(packet), &flags, (struct sockaddr *) &from, &fromLen, &packetInfo, &ttl);
250
251 if (packetLen >= 0)
252 {
253 SockAddrTomDNSAddr((struct sockaddr*)&from, &senderAddr, &senderPort);
254 SockAddrTomDNSAddr((struct sockaddr*)&packetInfo.ipi_addr, &destAddr, NULL);
255
256 // If we have broken IP_RECVDSTADDR functionality (so far
257 // I've only seen this on OpenBSD) then apply a hack to
258 // convince mDNS Core that this isn't a spoof packet.
259 // Basically what we do is check to see whether the
260 // packet arrived as a multicast and, if so, set its
261 // destAddr to the mDNS address.
262 //
263 // I must admit that I could just be doing something
264 // wrong on OpenBSD and hence triggering this problem
265 // but I'm at a loss as to how.
266 //
267 // If this platform doesn't have IP_PKTINFO or IP_RECVDSTADDR, then we have
268 // no way to tell the destination address or interface this packet arrived on,
269 // so all we can do is just assume it's a multicast
270
271 #if HAVE_BROKEN_RECVDSTADDR || (!defined(IP_PKTINFO) && !defined(IP_RECVDSTADDR))
272 if ((destAddr.NotAnInteger == 0) && (flags & MSG_MCAST))
273 {
274 destAddr.type = senderAddr.type;
275 if (senderAddr.type == mDNSAddrType_IPv4) destAddr.ip.v4 = AllDNSLinkGroup_v4.ip.v4;
276 else if (senderAddr.type == mDNSAddrType_IPv6) destAddr.ip.v6 = AllDNSLinkGroup_v6.ip.v6;
277 }
278 #endif
279
280 // We only accept the packet if the interface on which it came
281 // in matches the interface associated with this socket.
282 // We do this match by name or by index, depending on which
283 // information is available. recvfrom_flags sets the name
284 // to "" if the name isn't available, or the index to -1
285 // if the index is available. This accomodates the various
286 // different capabilities of our target platforms.
287
288 reject = mDNSfalse;
289 if (!intf)
290 {
291 // Ignore multicasts accidentally delivered to our unicast receiving socket
292 if (mDNSAddrIsDNSMulticast(&destAddr)) packetLen = -1;
293 }
294 else
295 {
296 if (packetInfo.ipi_ifname[0] != 0) reject = (strcmp(packetInfo.ipi_ifname, intf->intfName) != 0);
297 else if (packetInfo.ipi_ifindex != -1) reject = (packetInfo.ipi_ifindex != intf->index);
298
299 if (reject)
300 {
301 verbosedebugf("SocketDataReady ignored a packet from %#a to %#a on interface %s/%d expecting %#a/%s/%d/%d",
302 &senderAddr, &destAddr, packetInfo.ipi_ifname, packetInfo.ipi_ifindex,
303 &intf->coreIntf.ip, intf->intfName, intf->index, skt);
304 packetLen = -1;
305 num_pkts_rejected++;
306 if (num_pkts_rejected > (num_pkts_accepted + 1) * (num_registered_interfaces + 1) * 2)
307 {
308 fprintf(stderr,
309 "*** WARNING: Received %d packets; Accepted %d packets; Rejected %d packets because of interface mismatch\n",
310 num_pkts_accepted + num_pkts_rejected, num_pkts_accepted, num_pkts_rejected);
311 num_pkts_accepted = 0;
312 num_pkts_rejected = 0;
313 }
314 }
315 else
316 {
317 verbosedebugf("SocketDataReady got a packet from %#a to %#a on interface %#a/%s/%d/%d",
318 &senderAddr, &destAddr, &intf->coreIntf.ip, intf->intfName, intf->index, skt);
319 num_pkts_accepted++;
320 }
321 }
322 }
323
324 if (packetLen >= 0)
325 mDNSCoreReceive(m, &packet, (mDNSu8 *)&packet + packetLen,
326 &senderAddr, senderPort, &destAddr, MulticastDNSPort, InterfaceID);
327 }
328
mDNSPlatformPeekUDP(mDNS * const m,UDPSocket * src)329 mDNSexport mDNSBool mDNSPlatformPeekUDP(mDNS *const m, UDPSocket *src)
330 {
331 (void)m; // unused
332 (void)src; // unused
333 return mDNSfalse;
334 }
335
mDNSPlatformTCPSocket(mDNS * const m,TCPSocketFlags flags,mDNSIPPort * port,mDNSBool useBackgroundTrafficClass)336 mDNSexport TCPSocket *mDNSPlatformTCPSocket(mDNS * const m, TCPSocketFlags flags, mDNSIPPort * port, mDNSBool useBackgroundTrafficClass)
337 {
338 (void)m; // Unused
339 (void)flags; // Unused
340 (void)port; // Unused
341 (void)useBackgroundTrafficClass; // Unused
342 return NULL;
343 }
344
mDNSPlatformTCPAccept(TCPSocketFlags flags,int sd)345 mDNSexport TCPSocket *mDNSPlatformTCPAccept(TCPSocketFlags flags, int sd)
346 {
347 (void)flags; // Unused
348 (void)sd; // Unused
349 return NULL;
350 }
351
mDNSPlatformTCPGetFD(TCPSocket * sock)352 mDNSexport int mDNSPlatformTCPGetFD(TCPSocket *sock)
353 {
354 (void)sock; // Unused
355 return -1;
356 }
357
mDNSPlatformTCPConnect(TCPSocket * sock,const mDNSAddr * dst,mDNSOpaque16 dstport,domainname * hostname,mDNSInterfaceID InterfaceID,TCPConnectionCallback callback,void * context)358 mDNSexport mStatus mDNSPlatformTCPConnect(TCPSocket *sock, const mDNSAddr *dst, mDNSOpaque16 dstport, domainname *hostname, mDNSInterfaceID InterfaceID,
359 TCPConnectionCallback callback, void *context)
360 {
361 (void)sock; // Unused
362 (void)dst; // Unused
363 (void)dstport; // Unused
364 (void)hostname; // Unused
365 (void)InterfaceID; // Unused
366 (void)callback; // Unused
367 (void)context; // Unused
368 return(mStatus_UnsupportedErr);
369 }
370
mDNSPlatformTCPCloseConnection(TCPSocket * sock)371 mDNSexport void mDNSPlatformTCPCloseConnection(TCPSocket *sock)
372 {
373 (void)sock; // Unused
374 }
375
mDNSPlatformReadTCP(TCPSocket * sock,void * buf,unsigned long buflen,mDNSBool * closed)376 mDNSexport long mDNSPlatformReadTCP(TCPSocket *sock, void *buf, unsigned long buflen, mDNSBool * closed)
377 {
378 (void)sock; // Unused
379 (void)buf; // Unused
380 (void)buflen; // Unused
381 (void)closed; // Unused
382 return 0;
383 }
384
mDNSPlatformWriteTCP(TCPSocket * sock,const char * msg,unsigned long len)385 mDNSexport long mDNSPlatformWriteTCP(TCPSocket *sock, const char *msg, unsigned long len)
386 {
387 (void)sock; // Unused
388 (void)msg; // Unused
389 (void)len; // Unused
390 return 0;
391 }
392
mDNSPlatformUDPSocket(mDNS * const m,mDNSIPPort port)393 mDNSexport UDPSocket *mDNSPlatformUDPSocket(mDNS * const m, mDNSIPPort port)
394 {
395 (void)m; // Unused
396 (void)port; // Unused
397 return NULL;
398 }
399
mDNSPlatformUDPClose(UDPSocket * sock)400 mDNSexport void mDNSPlatformUDPClose(UDPSocket *sock)
401 {
402 (void)sock; // Unused
403 }
404
mDNSPlatformUpdateProxyList(mDNS * const m,const mDNSInterfaceID InterfaceID)405 mDNSexport void mDNSPlatformUpdateProxyList(mDNS *const m, const mDNSInterfaceID InterfaceID)
406 {
407 (void)m; // Unused
408 (void)InterfaceID; // Unused
409 }
410
mDNSPlatformSendRawPacket(const void * const msg,const mDNSu8 * const end,mDNSInterfaceID InterfaceID)411 mDNSexport void mDNSPlatformSendRawPacket(const void *const msg, const mDNSu8 *const end, mDNSInterfaceID InterfaceID)
412 {
413 (void)msg; // Unused
414 (void)end; // Unused
415 (void)InterfaceID; // Unused
416 }
417
mDNSPlatformSetLocalAddressCacheEntry(mDNS * const m,const mDNSAddr * const tpa,const mDNSEthAddr * const tha,mDNSInterfaceID InterfaceID)418 mDNSexport void mDNSPlatformSetLocalAddressCacheEntry(mDNS *const m, const mDNSAddr *const tpa, const mDNSEthAddr *const tha, mDNSInterfaceID InterfaceID)
419 {
420 (void)m; // Unused
421 (void)tpa; // Unused
422 (void)tha; // Unused
423 (void)InterfaceID; // Unused
424 }
425
mDNSPlatformTLSSetupCerts(void)426 mDNSexport mStatus mDNSPlatformTLSSetupCerts(void)
427 {
428 return(mStatus_UnsupportedErr);
429 }
430
mDNSPlatformTLSTearDownCerts(void)431 mDNSexport void mDNSPlatformTLSTearDownCerts(void)
432 {
433 }
434
mDNSPlatformSetAllowSleep(mDNS * const m,mDNSBool allowSleep,const char * reason)435 mDNSexport void mDNSPlatformSetAllowSleep(mDNS *const m, mDNSBool allowSleep, const char *reason)
436 {
437 (void) m;
438 (void) allowSleep;
439 (void) reason;
440 }
441
442 #if COMPILER_LIKES_PRAGMA_MARK
443 #pragma mark -
444 #pragma mark - /etc/hosts support
445 #endif
446
FreeEtcHosts(mDNS * const m,AuthRecord * const rr,mStatus result)447 mDNSexport void FreeEtcHosts(mDNS *const m, AuthRecord *const rr, mStatus result)
448 {
449 (void)m; // unused
450 (void)rr;
451 (void)result;
452 }
453
454
455 #if COMPILER_LIKES_PRAGMA_MARK
456 #pragma mark ***** DDNS Config Platform Functions
457 #endif
458
mDNSPlatformSetDNSConfig(mDNS * const m,mDNSBool setservers,mDNSBool setsearch,domainname * const fqdn,DNameListElem ** RegDomains,DNameListElem ** BrowseDomains,mDNSBool ackConfig)459 mDNSexport mDNSBool mDNSPlatformSetDNSConfig(mDNS *const m, mDNSBool setservers, mDNSBool setsearch, domainname *const fqdn, DNameListElem **RegDomains,
460 DNameListElem **BrowseDomains, mDNSBool ackConfig)
461 {
462 (void) m;
463 (void) setservers;
464 (void) fqdn;
465 (void) setsearch;
466 (void) RegDomains;
467 (void) BrowseDomains;
468 (void) ackConfig;
469
470 return mDNStrue;
471 }
472
mDNSPlatformGetPrimaryInterface(mDNS * const m,mDNSAddr * v4,mDNSAddr * v6,mDNSAddr * router)473 mDNSexport mStatus mDNSPlatformGetPrimaryInterface(mDNS * const m, mDNSAddr * v4, mDNSAddr * v6, mDNSAddr * router)
474 {
475 (void) m;
476 (void) v4;
477 (void) v6;
478 (void) router;
479
480 return mStatus_UnsupportedErr;
481 }
482
mDNSPlatformDynDNSHostNameStatusChanged(const domainname * const dname,const mStatus status)483 mDNSexport void mDNSPlatformDynDNSHostNameStatusChanged(const domainname *const dname, const mStatus status)
484 {
485 (void) dname;
486 (void) status;
487 }
488
489 #if COMPILER_LIKES_PRAGMA_MARK
490 #pragma mark ***** Init and Term
491 #endif
492
493 // This gets the current hostname, truncating it at the first dot if necessary
GetUserSpecifiedRFC1034ComputerName(domainlabel * const namelabel)494 mDNSlocal void GetUserSpecifiedRFC1034ComputerName(domainlabel *const namelabel)
495 {
496 int len = 0;
497 gethostname((char *)(&namelabel->c[1]), MAX_DOMAIN_LABEL);
498 while (len < MAX_DOMAIN_LABEL && namelabel->c[len+1] && namelabel->c[len+1] != '.') len++;
499 namelabel->c[0] = len;
500 }
501
502 // On OS X this gets the text of the field labelled "Computer Name" in the Sharing Prefs Control Panel
503 // Other platforms can either get the information from the appropriate place,
504 // or they can alternatively just require all registering services to provide an explicit name
GetUserSpecifiedFriendlyComputerName(domainlabel * const namelabel)505 mDNSlocal void GetUserSpecifiedFriendlyComputerName(domainlabel *const namelabel)
506 {
507 // On Unix we have no better name than the host name, so we just use that.
508 GetUserSpecifiedRFC1034ComputerName(namelabel);
509 }
510
ParseDNSServers(mDNS * m,const char * filePath)511 mDNSexport int ParseDNSServers(mDNS *m, const char *filePath)
512 {
513 char line[256];
514 char nameserver[16];
515 char keyword[11];
516 int numOfServers = 0;
517 FILE *fp = fopen(filePath, "r");
518 if (fp == NULL) return -1;
519 while (fgets(line,sizeof(line),fp))
520 {
521 struct in_addr ina;
522 line[255]='\0'; // just to be safe
523 if (sscanf(line,"%10s %15s", keyword, nameserver) != 2) continue; // it will skip whitespaces
524 if (strncasecmp(keyword,"nameserver",10)) continue;
525 if (inet_aton(nameserver, (struct in_addr *)&ina) != 0)
526 {
527 mDNSAddr DNSAddr;
528 DNSAddr.type = mDNSAddrType_IPv4;
529 DNSAddr.ip.v4.NotAnInteger = ina.s_addr;
530 mDNS_AddDNSServer(m, NULL, mDNSInterface_Any, 0, &DNSAddr, UnicastDNSPort, kScopeNone, 0, mDNSfalse, 0, mDNStrue, mDNStrue, mDNSfalse);
531 numOfServers++;
532 }
533 }
534 fclose(fp);
535 return (numOfServers > 0) ? 0 : -1;
536 }
537
538 // Searches the interface list looking for the named interface.
539 // Returns a pointer to if it found, or NULL otherwise.
SearchForInterfaceByName(mDNS * const m,const char * intfName)540 mDNSlocal PosixNetworkInterface *SearchForInterfaceByName(mDNS *const m, const char *intfName)
541 {
542 PosixNetworkInterface *intf;
543
544 assert(m != NULL);
545 assert(intfName != NULL);
546
547 intf = (PosixNetworkInterface*)(m->HostInterfaces);
548 while ((intf != NULL) && (strcmp(intf->intfName, intfName) != 0))
549 intf = (PosixNetworkInterface *)(intf->coreIntf.next);
550
551 return intf;
552 }
553
mDNSPlatformInterfaceIDfromInterfaceIndex(mDNS * const m,mDNSu32 index)554 mDNSexport mDNSInterfaceID mDNSPlatformInterfaceIDfromInterfaceIndex(mDNS *const m, mDNSu32 index)
555 {
556 PosixNetworkInterface *intf;
557
558 assert(m != NULL);
559
560 if (index == kDNSServiceInterfaceIndexLocalOnly) return(mDNSInterface_LocalOnly);
561 if (index == kDNSServiceInterfaceIndexP2P ) return(mDNSInterface_P2P);
562 if (index == kDNSServiceInterfaceIndexAny ) return(mDNSInterface_Any);
563
564 intf = (PosixNetworkInterface*)(m->HostInterfaces);
565 while ((intf != NULL) && (mDNSu32) intf->index != index)
566 intf = (PosixNetworkInterface *)(intf->coreIntf.next);
567
568 return (mDNSInterfaceID) intf;
569 }
570
mDNSPlatformInterfaceIndexfromInterfaceID(mDNS * const m,mDNSInterfaceID id,mDNSBool suppressNetworkChange)571 mDNSexport mDNSu32 mDNSPlatformInterfaceIndexfromInterfaceID(mDNS *const m, mDNSInterfaceID id, mDNSBool suppressNetworkChange)
572 {
573 PosixNetworkInterface *intf;
574 (void) suppressNetworkChange; // Unused
575
576 assert(m != NULL);
577
578 if (id == mDNSInterface_LocalOnly) return(kDNSServiceInterfaceIndexLocalOnly);
579 if (id == mDNSInterface_P2P ) return(kDNSServiceInterfaceIndexP2P);
580 if (id == mDNSInterface_Any ) return(kDNSServiceInterfaceIndexAny);
581
582 intf = (PosixNetworkInterface*)(m->HostInterfaces);
583 while ((intf != NULL) && (mDNSInterfaceID) intf != id)
584 intf = (PosixNetworkInterface *)(intf->coreIntf.next);
585
586 if (intf) return intf->index;
587
588 // If we didn't find the interface, check the RecentInterfaces list as well
589 intf = gRecentInterfaces;
590 while ((intf != NULL) && (mDNSInterfaceID) intf != id)
591 intf = (PosixNetworkInterface *)(intf->coreIntf.next);
592
593 return intf ? intf->index : 0;
594 }
595
596 // Frees the specified PosixNetworkInterface structure. The underlying
597 // interface must have already been deregistered with the mDNS core.
FreePosixNetworkInterface(PosixNetworkInterface * intf)598 mDNSlocal void FreePosixNetworkInterface(PosixNetworkInterface *intf)
599 {
600 assert(intf != NULL);
601 if (intf->intfName != NULL) free((void *)intf->intfName);
602 if (intf->multicastSocket4 != -1) assert(close(intf->multicastSocket4) == 0);
603 #if HAVE_IPV6
604 if (intf->multicastSocket6 != -1) assert(close(intf->multicastSocket6) == 0);
605 #endif
606
607 // Move interface to the RecentInterfaces list for a minute
608 intf->LastSeen = mDNSPlatformUTC();
609 intf->coreIntf.next = &gRecentInterfaces->coreIntf;
610 gRecentInterfaces = intf;
611 }
612
613 // Grab the first interface, deregister it, free it, and repeat until done.
ClearInterfaceList(mDNS * const m)614 mDNSlocal void ClearInterfaceList(mDNS *const m)
615 {
616 assert(m != NULL);
617
618 while (m->HostInterfaces)
619 {
620 PosixNetworkInterface *intf = (PosixNetworkInterface*)(m->HostInterfaces);
621 mDNS_DeregisterInterface(m, &intf->coreIntf, mDNSfalse);
622 if (gMDNSPlatformPosixVerboseLevel > 0) fprintf(stderr, "Deregistered interface %s\n", intf->intfName);
623 FreePosixNetworkInterface(intf);
624 }
625 num_registered_interfaces = 0;
626 num_pkts_accepted = 0;
627 num_pkts_rejected = 0;
628 }
629
630 // Sets up a send/receive socket.
631 // If mDNSIPPort port is non-zero, then it's a multicast socket on the specified interface
632 // If mDNSIPPort port is zero, then it's a randomly assigned port number, used for sending unicast queries
SetupSocket(struct sockaddr * intfAddr,mDNSIPPort port,int interfaceIndex,int * sktPtr)633 mDNSlocal int SetupSocket(struct sockaddr *intfAddr, mDNSIPPort port, int interfaceIndex, int *sktPtr)
634 {
635 int err = 0;
636 static const int kOn = 1;
637 static const int kIntTwoFiveFive = 255;
638 static const unsigned char kByteTwoFiveFive = 255;
639 const mDNSBool JoinMulticastGroup = (port.NotAnInteger != 0);
640
641 (void) interfaceIndex; // This parameter unused on plaforms that don't have IPv6
642 assert(intfAddr != NULL);
643 assert(sktPtr != NULL);
644 assert(*sktPtr == -1);
645
646 // Open the socket...
647 if (intfAddr->sa_family == AF_INET) *sktPtr = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP);
648 #if HAVE_IPV6
649 else if (intfAddr->sa_family == AF_INET6) *sktPtr = socket(PF_INET6, SOCK_DGRAM, IPPROTO_UDP);
650 #endif
651 else return EINVAL;
652
653 if (*sktPtr < 0) { err = errno; perror((intfAddr->sa_family == AF_INET) ? "socket AF_INET" : "socket AF_INET6"); }
654
655 // ... with a shared UDP port, if it's for multicast receiving
656 if (err == 0 && port.NotAnInteger)
657 {
658 #if defined(SO_REUSEPORT)
659 err = setsockopt(*sktPtr, SOL_SOCKET, SO_REUSEPORT, &kOn, sizeof(kOn));
660 #elif defined(SO_REUSEADDR)
661 err = setsockopt(*sktPtr, SOL_SOCKET, SO_REUSEADDR, &kOn, sizeof(kOn));
662 #else
663 #error This platform has no way to avoid address busy errors on multicast.
664 #endif
665 if (err < 0) { err = errno; perror("setsockopt - SO_REUSExxxx"); }
666
667 // Enable inbound packets on IFEF_AWDL interface.
668 // Only done for multicast sockets, since we don't expect unicast socket operations
669 // on the IFEF_AWDL interface. Operation is a no-op for other interface types.
670 #ifdef SO_RECV_ANYIF
671 if (setsockopt(*sktPtr, SOL_SOCKET, SO_RECV_ANYIF, &kOn, sizeof(kOn)) < 0) perror("setsockopt - SO_RECV_ANYIF");
672 #endif
673 }
674
675 // We want to receive destination addresses and interface identifiers.
676 if (intfAddr->sa_family == AF_INET)
677 {
678 struct ip_mreq imr;
679 struct sockaddr_in bindAddr;
680 if (err == 0)
681 {
682 #if defined(IP_PKTINFO) // Linux
683 err = setsockopt(*sktPtr, IPPROTO_IP, IP_PKTINFO, &kOn, sizeof(kOn));
684 if (err < 0) { err = errno; perror("setsockopt - IP_PKTINFO"); }
685 #elif defined(IP_RECVDSTADDR) || defined(IP_RECVIF) // BSD and Solaris
686 #if defined(IP_RECVDSTADDR)
687 err = setsockopt(*sktPtr, IPPROTO_IP, IP_RECVDSTADDR, &kOn, sizeof(kOn));
688 if (err < 0) { err = errno; perror("setsockopt - IP_RECVDSTADDR"); }
689 #endif
690 #if defined(IP_RECVIF)
691 if (err == 0)
692 {
693 err = setsockopt(*sktPtr, IPPROTO_IP, IP_RECVIF, &kOn, sizeof(kOn));
694 if (err < 0) { err = errno; perror("setsockopt - IP_RECVIF"); }
695 }
696 #endif
697 #else
698 #warning This platform has no way to get the destination interface information -- will only work for single-homed hosts
699 #endif
700 }
701 #if defined(IP_RECVTTL) // Linux
702 if (err == 0)
703 {
704 setsockopt(*sktPtr, IPPROTO_IP, IP_RECVTTL, &kOn, sizeof(kOn));
705 // We no longer depend on being able to get the received TTL, so don't worry if the option fails
706 }
707 #endif
708
709 // Add multicast group membership on this interface
710 if (err == 0 && JoinMulticastGroup)
711 {
712 imr.imr_multiaddr.s_addr = AllDNSLinkGroup_v4.ip.v4.NotAnInteger;
713 imr.imr_interface = ((struct sockaddr_in*)intfAddr)->sin_addr;
714 err = setsockopt(*sktPtr, IPPROTO_IP, IP_ADD_MEMBERSHIP, &imr, sizeof(imr));
715 if (err < 0) { err = errno; perror("setsockopt - IP_ADD_MEMBERSHIP"); }
716 }
717
718 // Specify outgoing interface too
719 if (err == 0 && JoinMulticastGroup)
720 {
721 err = setsockopt(*sktPtr, IPPROTO_IP, IP_MULTICAST_IF, &((struct sockaddr_in*)intfAddr)->sin_addr, sizeof(struct in_addr));
722 if (err < 0) { err = errno; perror("setsockopt - IP_MULTICAST_IF"); }
723 }
724
725 // Per the mDNS spec, send unicast packets with TTL 255
726 if (err == 0)
727 {
728 err = setsockopt(*sktPtr, IPPROTO_IP, IP_TTL, &kIntTwoFiveFive, sizeof(kIntTwoFiveFive));
729 if (err < 0) { err = errno; perror("setsockopt - IP_TTL"); }
730 }
731
732 // and multicast packets with TTL 255 too
733 // There's some debate as to whether IP_MULTICAST_TTL is an int or a byte so we just try both.
734 if (err == 0)
735 {
736 err = setsockopt(*sktPtr, IPPROTO_IP, IP_MULTICAST_TTL, &kByteTwoFiveFive, sizeof(kByteTwoFiveFive));
737 if (err < 0 && errno == EINVAL)
738 err = setsockopt(*sktPtr, IPPROTO_IP, IP_MULTICAST_TTL, &kIntTwoFiveFive, sizeof(kIntTwoFiveFive));
739 if (err < 0) { err = errno; perror("setsockopt - IP_MULTICAST_TTL"); }
740 }
741
742 // And start listening for packets
743 if (err == 0)
744 {
745 bindAddr.sin_family = AF_INET;
746 bindAddr.sin_port = port.NotAnInteger;
747 bindAddr.sin_addr.s_addr = INADDR_ANY; // Want to receive multicasts AND unicasts on this socket
748 err = bind(*sktPtr, (struct sockaddr *) &bindAddr, sizeof(bindAddr));
749 if (err < 0) { err = errno; perror("bind"); fflush(stderr); }
750 }
751 } // endif (intfAddr->sa_family == AF_INET)
752
753 #if HAVE_IPV6
754 else if (intfAddr->sa_family == AF_INET6)
755 {
756 struct ipv6_mreq imr6;
757 struct sockaddr_in6 bindAddr6;
758 #if defined(IPV6_RECVPKTINFO) // Solaris
759 if (err == 0)
760 {
761 err = setsockopt(*sktPtr, IPPROTO_IPV6, IPV6_RECVPKTINFO, &kOn, sizeof(kOn));
762 if (err < 0) { err = errno; perror("setsockopt - IPV6_RECVPKTINFO"); }
763 }
764 #elif defined(IPV6_PKTINFO)
765 if (err == 0)
766 {
767 err = setsockopt(*sktPtr, IPPROTO_IPV6, IPV6_2292_PKTINFO, &kOn, sizeof(kOn));
768 if (err < 0) { err = errno; perror("setsockopt - IPV6_PKTINFO"); }
769 }
770 #else
771 #warning This platform has no way to get the destination interface information for IPv6 -- will only work for single-homed hosts
772 #endif
773 #if defined(IPV6_RECVHOPLIMIT)
774 if (err == 0)
775 {
776 err = setsockopt(*sktPtr, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &kOn, sizeof(kOn));
777 if (err < 0) { err = errno; perror("setsockopt - IPV6_RECVHOPLIMIT"); }
778 }
779 #elif defined(IPV6_HOPLIMIT)
780 if (err == 0)
781 {
782 err = setsockopt(*sktPtr, IPPROTO_IPV6, IPV6_2292_HOPLIMIT, &kOn, sizeof(kOn));
783 if (err < 0) { err = errno; perror("setsockopt - IPV6_HOPLIMIT"); }
784 }
785 #endif
786
787 // Add multicast group membership on this interface
788 if (err == 0 && JoinMulticastGroup)
789 {
790 imr6.ipv6mr_multiaddr = *(const struct in6_addr*)&AllDNSLinkGroup_v6.ip.v6;
791 imr6.ipv6mr_interface = interfaceIndex;
792 //LogMsg("Joining %.16a on %d", &imr6.ipv6mr_multiaddr, imr6.ipv6mr_interface);
793 err = setsockopt(*sktPtr, IPPROTO_IPV6, IPV6_JOIN_GROUP, &imr6, sizeof(imr6));
794 if (err < 0)
795 {
796 err = errno;
797 verbosedebugf("IPV6_JOIN_GROUP %.16a on %d failed.\n", &imr6.ipv6mr_multiaddr, imr6.ipv6mr_interface);
798 perror("setsockopt - IPV6_JOIN_GROUP");
799 }
800 }
801
802 // Specify outgoing interface too
803 if (err == 0 && JoinMulticastGroup)
804 {
805 u_int multicast_if = interfaceIndex;
806 err = setsockopt(*sktPtr, IPPROTO_IPV6, IPV6_MULTICAST_IF, &multicast_if, sizeof(multicast_if));
807 if (err < 0) { err = errno; perror("setsockopt - IPV6_MULTICAST_IF"); }
808 }
809
810 // We want to receive only IPv6 packets on this socket.
811 // Without this option, we may get IPv4 addresses as mapped addresses.
812 if (err == 0)
813 {
814 err = setsockopt(*sktPtr, IPPROTO_IPV6, IPV6_V6ONLY, &kOn, sizeof(kOn));
815 if (err < 0) { err = errno; perror("setsockopt - IPV6_V6ONLY"); }
816 }
817
818 // Per the mDNS spec, send unicast packets with TTL 255
819 if (err == 0)
820 {
821 err = setsockopt(*sktPtr, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &kIntTwoFiveFive, sizeof(kIntTwoFiveFive));
822 if (err < 0) { err = errno; perror("setsockopt - IPV6_UNICAST_HOPS"); }
823 }
824
825 // and multicast packets with TTL 255 too
826 // There's some debate as to whether IPV6_MULTICAST_HOPS is an int or a byte so we just try both.
827 if (err == 0)
828 {
829 err = setsockopt(*sktPtr, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &kByteTwoFiveFive, sizeof(kByteTwoFiveFive));
830 if (err < 0 && errno == EINVAL)
831 err = setsockopt(*sktPtr, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &kIntTwoFiveFive, sizeof(kIntTwoFiveFive));
832 if (err < 0) { err = errno; perror("setsockopt - IPV6_MULTICAST_HOPS"); }
833 }
834
835 // And start listening for packets
836 if (err == 0)
837 {
838 mDNSPlatformMemZero(&bindAddr6, sizeof(bindAddr6));
839 #ifndef NOT_HAVE_SA_LEN
840 bindAddr6.sin6_len = sizeof(bindAddr6);
841 #endif
842 bindAddr6.sin6_family = AF_INET6;
843 bindAddr6.sin6_port = port.NotAnInteger;
844 bindAddr6.sin6_flowinfo = 0;
845 bindAddr6.sin6_addr = in6addr_any; // Want to receive multicasts AND unicasts on this socket
846 bindAddr6.sin6_scope_id = 0;
847 err = bind(*sktPtr, (struct sockaddr *) &bindAddr6, sizeof(bindAddr6));
848 if (err < 0) { err = errno; perror("bind"); fflush(stderr); }
849 }
850 } // endif (intfAddr->sa_family == AF_INET6)
851 #endif
852
853 // Set the socket to non-blocking.
854 if (err == 0)
855 {
856 err = fcntl(*sktPtr, F_GETFL, 0);
857 if (err < 0) err = errno;
858 else
859 {
860 err = fcntl(*sktPtr, F_SETFL, err | O_NONBLOCK);
861 if (err < 0) err = errno;
862 }
863 }
864
865 // Clean up
866 if (err != 0 && *sktPtr != -1) { assert(close(*sktPtr) == 0); *sktPtr = -1; }
867 assert((err == 0) == (*sktPtr != -1));
868 return err;
869 }
870
871 // Creates a PosixNetworkInterface for the interface whose IP address is
872 // intfAddr and whose name is intfName and registers it with mDNS core.
SetupOneInterface(mDNS * const m,struct sockaddr * intfAddr,struct sockaddr * intfMask,const char * intfName,int intfIndex)873 mDNSlocal int SetupOneInterface(mDNS *const m, struct sockaddr *intfAddr, struct sockaddr *intfMask, const char *intfName, int intfIndex)
874 {
875 int err = 0;
876 PosixNetworkInterface *intf;
877 PosixNetworkInterface *alias = NULL;
878
879 assert(m != NULL);
880 assert(intfAddr != NULL);
881 assert(intfName != NULL);
882 assert(intfMask != NULL);
883
884 // Allocate the interface structure itself.
885 intf = (PosixNetworkInterface*)malloc(sizeof(*intf));
886 if (intf == NULL) { assert(0); err = ENOMEM; }
887
888 // And make a copy of the intfName.
889 if (err == 0)
890 {
891 intf->intfName = strdup(intfName);
892 if (intf->intfName == NULL) { assert(0); err = ENOMEM; }
893 }
894
895 if (err == 0)
896 {
897 // Set up the fields required by the mDNS core.
898 SockAddrTomDNSAddr(intfAddr, &intf->coreIntf.ip, NULL);
899 SockAddrTomDNSAddr(intfMask, &intf->coreIntf.mask, NULL);
900
901 //LogMsg("SetupOneInterface: %#a %#a", &intf->coreIntf.ip, &intf->coreIntf.mask);
902 strncpy(intf->coreIntf.ifname, intfName, sizeof(intf->coreIntf.ifname));
903 intf->coreIntf.ifname[sizeof(intf->coreIntf.ifname)-1] = 0;
904 intf->coreIntf.Advertise = m->AdvertiseLocalAddresses;
905 intf->coreIntf.McastTxRx = mDNStrue;
906
907 // Set up the extra fields in PosixNetworkInterface.
908 assert(intf->intfName != NULL); // intf->intfName already set up above
909 intf->index = intfIndex;
910 intf->multicastSocket4 = -1;
911 #if HAVE_IPV6
912 intf->multicastSocket6 = -1;
913 #endif
914 alias = SearchForInterfaceByName(m, intf->intfName);
915 if (alias == NULL) alias = intf;
916 intf->coreIntf.InterfaceID = (mDNSInterfaceID)alias;
917
918 if (alias != intf)
919 debugf("SetupOneInterface: %s %#a is an alias of %#a", intfName, &intf->coreIntf.ip, &alias->coreIntf.ip);
920 }
921
922 // Set up the multicast socket
923 if (err == 0)
924 {
925 if (alias->multicastSocket4 == -1 && intfAddr->sa_family == AF_INET)
926 err = SetupSocket(intfAddr, MulticastDNSPort, intf->index, &alias->multicastSocket4);
927 #if HAVE_IPV6
928 else if (alias->multicastSocket6 == -1 && intfAddr->sa_family == AF_INET6)
929 err = SetupSocket(intfAddr, MulticastDNSPort, intf->index, &alias->multicastSocket6);
930 #endif
931 }
932
933 // If interface is a direct link, address record will be marked as kDNSRecordTypeKnownUnique
934 // and skip the probe phase of the probe/announce packet sequence.
935 intf->coreIntf.DirectLink = mDNSfalse;
936 #ifdef DIRECTLINK_INTERFACE_NAME
937 if (strcmp(intfName, STRINGIFY(DIRECTLINK_INTERFACE_NAME)) == 0)
938 intf->coreIntf.DirectLink = mDNStrue;
939 #endif
940
941 // The interface is all ready to go, let's register it with the mDNS core.
942 if (err == 0)
943 err = mDNS_RegisterInterface(m, &intf->coreIntf, mDNSfalse);
944
945 // Clean up.
946 if (err == 0)
947 {
948 num_registered_interfaces++;
949 debugf("SetupOneInterface: %s %#a Registered", intf->intfName, &intf->coreIntf.ip);
950 if (gMDNSPlatformPosixVerboseLevel > 0)
951 fprintf(stderr, "Registered interface %s\n", intf->intfName);
952 }
953 else
954 {
955 // Use intfName instead of intf->intfName in the next line to avoid dereferencing NULL.
956 debugf("SetupOneInterface: %s %#a failed to register %d", intfName, &intf->coreIntf.ip, err);
957 if (intf) { FreePosixNetworkInterface(intf); intf = NULL; }
958 }
959
960 assert((err == 0) == (intf != NULL));
961
962 return err;
963 }
964
965 // Call get_ifi_info() to obtain a list of active interfaces and call SetupOneInterface() on each one.
SetupInterfaceList(mDNS * const m)966 mDNSlocal int SetupInterfaceList(mDNS *const m)
967 {
968 mDNSBool foundav4 = mDNSfalse;
969 int err = 0;
970 struct ifi_info *intfList = get_ifi_info(AF_INET, mDNStrue);
971 struct ifi_info *firstLoopback = NULL;
972
973 assert(m != NULL);
974 debugf("SetupInterfaceList");
975
976 if (intfList == NULL) err = ENOENT;
977
978 #if HAVE_IPV6
979 if (err == 0) /* Link the IPv6 list to the end of the IPv4 list */
980 {
981 struct ifi_info **p = &intfList;
982 while (*p) p = &(*p)->ifi_next;
983 *p = get_ifi_info(AF_INET6, mDNStrue);
984 }
985 #endif
986
987 if (err == 0)
988 {
989 struct ifi_info *i = intfList;
990 while (i)
991 {
992 if ( ((i->ifi_addr->sa_family == AF_INET)
993 #if HAVE_IPV6
994 || (i->ifi_addr->sa_family == AF_INET6)
995 #endif
996 ) && (i->ifi_flags & IFF_UP) && !(i->ifi_flags & IFF_POINTOPOINT))
997 {
998 if (i->ifi_flags & IFF_LOOPBACK)
999 {
1000 if (firstLoopback == NULL)
1001 firstLoopback = i;
1002 }
1003 else
1004 {
1005 if (SetupOneInterface(m, i->ifi_addr, i->ifi_netmask, i->ifi_name, i->ifi_index) == 0)
1006 if (i->ifi_addr->sa_family == AF_INET)
1007 foundav4 = mDNStrue;
1008 }
1009 }
1010 i = i->ifi_next;
1011 }
1012
1013 // If we found no normal interfaces but we did find a loopback interface, register the
1014 // loopback interface. This allows self-discovery if no interfaces are configured.
1015 // Temporary workaround: Multicast loopback on IPv6 interfaces appears not to work.
1016 // In the interim, we skip loopback interface only if we found at least one v4 interface to use
1017 // if ((m->HostInterfaces == NULL) && (firstLoopback != NULL))
1018 if (!foundav4 && firstLoopback)
1019 (void) SetupOneInterface(m, firstLoopback->ifi_addr, firstLoopback->ifi_netmask, firstLoopback->ifi_name, firstLoopback->ifi_index);
1020 }
1021
1022 // Clean up.
1023 if (intfList != NULL) free_ifi_info(intfList);
1024
1025 // Clean up any interfaces that have been hanging around on the RecentInterfaces list for more than a minute
1026 PosixNetworkInterface **ri = &gRecentInterfaces;
1027 const mDNSs32 utc = mDNSPlatformUTC();
1028 while (*ri)
1029 {
1030 PosixNetworkInterface *pi = *ri;
1031 if (utc - pi->LastSeen < 60) ri = (PosixNetworkInterface **)&pi->coreIntf.next;
1032 else { *ri = (PosixNetworkInterface *)pi->coreIntf.next; free(pi); }
1033 }
1034
1035 return err;
1036 }
1037
1038 #if USES_NETLINK
1039
1040 // See <http://www.faqs.org/rfcs/rfc3549.html> for a description of NetLink
1041
1042 // Open a socket that will receive interface change notifications
OpenIfNotifySocket(int * pFD)1043 mDNSlocal mStatus OpenIfNotifySocket(int *pFD)
1044 {
1045 mStatus err = mStatus_NoError;
1046 struct sockaddr_nl snl;
1047 int sock;
1048 int ret;
1049
1050 sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
1051 if (sock < 0)
1052 return errno;
1053
1054 // Configure read to be non-blocking because inbound msg size is not known in advance
1055 (void) fcntl(sock, F_SETFL, O_NONBLOCK);
1056
1057 /* Subscribe the socket to Link & IP addr notifications. */
1058 mDNSPlatformMemZero(&snl, sizeof snl);
1059 snl.nl_family = AF_NETLINK;
1060 snl.nl_groups = RTMGRP_LINK | RTMGRP_IPV4_IFADDR;
1061 ret = bind(sock, (struct sockaddr *) &snl, sizeof snl);
1062 if (0 == ret)
1063 *pFD = sock;
1064 else
1065 err = errno;
1066
1067 return err;
1068 }
1069
1070 #if MDNS_DEBUGMSGS
PrintNetLinkMsg(const struct nlmsghdr * pNLMsg)1071 mDNSlocal void PrintNetLinkMsg(const struct nlmsghdr *pNLMsg)
1072 {
1073 const char *kNLMsgTypes[] = { "", "NLMSG_NOOP", "NLMSG_ERROR", "NLMSG_DONE", "NLMSG_OVERRUN" };
1074 const char *kNLRtMsgTypes[] = { "RTM_NEWLINK", "RTM_DELLINK", "RTM_GETLINK", "RTM_NEWADDR", "RTM_DELADDR", "RTM_GETADDR" };
1075
1076 printf("nlmsghdr len=%d, type=%s, flags=0x%x\n", pNLMsg->nlmsg_len,
1077 pNLMsg->nlmsg_type < RTM_BASE ? kNLMsgTypes[pNLMsg->nlmsg_type] : kNLRtMsgTypes[pNLMsg->nlmsg_type - RTM_BASE],
1078 pNLMsg->nlmsg_flags);
1079
1080 if (RTM_NEWLINK <= pNLMsg->nlmsg_type && pNLMsg->nlmsg_type <= RTM_GETLINK)
1081 {
1082 struct ifinfomsg *pIfInfo = (struct ifinfomsg*) NLMSG_DATA(pNLMsg);
1083 printf("ifinfomsg family=%d, type=%d, index=%d, flags=0x%x, change=0x%x\n", pIfInfo->ifi_family,
1084 pIfInfo->ifi_type, pIfInfo->ifi_index, pIfInfo->ifi_flags, pIfInfo->ifi_change);
1085
1086 }
1087 else if (RTM_NEWADDR <= pNLMsg->nlmsg_type && pNLMsg->nlmsg_type <= RTM_GETADDR)
1088 {
1089 struct ifaddrmsg *pIfAddr = (struct ifaddrmsg*) NLMSG_DATA(pNLMsg);
1090 printf("ifaddrmsg family=%d, index=%d, flags=0x%x\n", pIfAddr->ifa_family,
1091 pIfAddr->ifa_index, pIfAddr->ifa_flags);
1092 }
1093 printf("\n");
1094 }
1095 #endif
1096
ProcessRoutingNotification(int sd)1097 mDNSlocal mDNSu32 ProcessRoutingNotification(int sd)
1098 // Read through the messages on sd and if any indicate that any interface records should
1099 // be torn down and rebuilt, return affected indices as a bitmask. Otherwise return 0.
1100 {
1101 ssize_t readCount;
1102 char buff[4096];
1103 struct nlmsghdr *pNLMsg = (struct nlmsghdr*) buff;
1104 mDNSu32 result = 0;
1105
1106 // The structure here is more complex than it really ought to be because,
1107 // unfortunately, there's no good way to size a buffer in advance large
1108 // enough to hold all pending data and so avoid message fragmentation.
1109 // (Note that FIONREAD is not supported on AF_NETLINK.)
1110
1111 readCount = read(sd, buff, sizeof buff);
1112 while (1)
1113 {
1114 // Make sure we've got an entire nlmsghdr in the buffer, and payload, too.
1115 // If not, discard already-processed messages in buffer and read more data.
1116 if (((char*) &pNLMsg[1] > (buff + readCount)) || // i.e. *pNLMsg extends off end of buffer
1117 ((char*) pNLMsg + pNLMsg->nlmsg_len > (buff + readCount)))
1118 {
1119 if (buff < (char*) pNLMsg) // we have space to shuffle
1120 {
1121 // discard processed data
1122 readCount -= ((char*) pNLMsg - buff);
1123 memmove(buff, pNLMsg, readCount);
1124 pNLMsg = (struct nlmsghdr*) buff;
1125
1126 // read more data
1127 readCount += read(sd, buff + readCount, sizeof buff - readCount);
1128 continue; // spin around and revalidate with new readCount
1129 }
1130 else
1131 break; // Otherwise message does not fit in buffer
1132 }
1133
1134 #if MDNS_DEBUGMSGS
1135 PrintNetLinkMsg(pNLMsg);
1136 #endif
1137
1138 // Process the NetLink message
1139 if (pNLMsg->nlmsg_type == RTM_GETLINK || pNLMsg->nlmsg_type == RTM_NEWLINK)
1140 result |= 1 << ((struct ifinfomsg*) NLMSG_DATA(pNLMsg))->ifi_index;
1141 else if (pNLMsg->nlmsg_type == RTM_DELADDR || pNLMsg->nlmsg_type == RTM_NEWADDR)
1142 result |= 1 << ((struct ifaddrmsg*) NLMSG_DATA(pNLMsg))->ifa_index;
1143
1144 // Advance pNLMsg to the next message in the buffer
1145 if ((pNLMsg->nlmsg_flags & NLM_F_MULTI) != 0 && pNLMsg->nlmsg_type != NLMSG_DONE)
1146 {
1147 ssize_t len = readCount - ((char*)pNLMsg - buff);
1148 pNLMsg = NLMSG_NEXT(pNLMsg, len);
1149 }
1150 else
1151 break; // all done!
1152 }
1153
1154 return result;
1155 }
1156
1157 #else // USES_NETLINK
1158
1159 // Open a socket that will receive interface change notifications
OpenIfNotifySocket(int * pFD)1160 mDNSlocal mStatus OpenIfNotifySocket(int *pFD)
1161 {
1162 *pFD = socket(AF_ROUTE, SOCK_RAW, 0);
1163
1164 if (*pFD < 0)
1165 return mStatus_UnknownErr;
1166
1167 // Configure read to be non-blocking because inbound msg size is not known in advance
1168 (void) fcntl(*pFD, F_SETFL, O_NONBLOCK);
1169
1170 return mStatus_NoError;
1171 }
1172
1173 #if MDNS_DEBUGMSGS
PrintRoutingSocketMsg(const struct ifa_msghdr * pRSMsg)1174 mDNSlocal void PrintRoutingSocketMsg(const struct ifa_msghdr *pRSMsg)
1175 {
1176 const char *kRSMsgTypes[] = { "", "RTM_ADD", "RTM_DELETE", "RTM_CHANGE", "RTM_GET", "RTM_LOSING",
1177 "RTM_REDIRECT", "RTM_MISS", "RTM_LOCK", "RTM_OLDADD", "RTM_OLDDEL", "RTM_RESOLVE",
1178 "RTM_NEWADDR", "RTM_DELADDR", "RTM_IFINFO", "RTM_NEWMADDR", "RTM_DELMADDR" };
1179
1180 int index = pRSMsg->ifam_type == RTM_IFINFO ? ((struct if_msghdr*) pRSMsg)->ifm_index : pRSMsg->ifam_index;
1181
1182 printf("ifa_msghdr len=%d, type=%s, index=%d\n", pRSMsg->ifam_msglen, kRSMsgTypes[pRSMsg->ifam_type], index);
1183 }
1184 #endif
1185
ProcessRoutingNotification(int sd)1186 mDNSlocal mDNSu32 ProcessRoutingNotification(int sd)
1187 // Read through the messages on sd and if any indicate that any interface records should
1188 // be torn down and rebuilt, return affected indices as a bitmask. Otherwise return 0.
1189 {
1190 ssize_t readCount;
1191 char buff[4096];
1192 struct ifa_msghdr *pRSMsg = (struct ifa_msghdr*) buff;
1193 mDNSu32 result = 0;
1194
1195 readCount = read(sd, buff, sizeof buff);
1196 if (readCount < (ssize_t) sizeof(struct ifa_msghdr))
1197 return mStatus_UnsupportedErr; // cannot decipher message
1198
1199 #if MDNS_DEBUGMSGS
1200 PrintRoutingSocketMsg(pRSMsg);
1201 #endif
1202
1203 // Process the message
1204 switch (pRSMsg->ifam_type)
1205 {
1206 case RTM_NEWADDR:
1207 case RTM_DELADDR:
1208 case RTM_IFINFO:
1209 if (pRSMsg->ifam_type == RTM_IFINFO)
1210 result |= 1 << ((struct if_msghdr*) pRSMsg)->ifm_index;
1211 else
1212 result |= 1 << pRSMsg->ifam_index;
1213 break;
1214 /*
1215 * ADD & DELETE are happening when IPv6 announces are changing,
1216 * and for some reason it will stop mdnsd to announce IPv6
1217 * addresses. So we force mdnsd to check interfaces.
1218 */
1219 case RTM_ADD:
1220 case RTM_DELETE:
1221 result |= 1;
1222 }
1223
1224 return result;
1225 }
1226
1227 #endif // USES_NETLINK
1228
1229 // Called when data appears on interface change notification socket
InterfaceChangeCallback(int fd,short filter,void * context)1230 mDNSlocal void InterfaceChangeCallback(int fd, short filter, void *context)
1231 {
1232 IfChangeRec *pChgRec = (IfChangeRec*) context;
1233 fd_set readFDs;
1234 mDNSu32 changedInterfaces = 0;
1235 struct timeval zeroTimeout = { 0, 0 };
1236
1237 (void)fd; // Unused
1238 (void)filter; // Unused
1239
1240 FD_ZERO(&readFDs);
1241 FD_SET(pChgRec->NotifySD, &readFDs);
1242
1243 do
1244 {
1245 changedInterfaces |= ProcessRoutingNotification(pChgRec->NotifySD);
1246 }
1247 while (0 < select(pChgRec->NotifySD + 1, &readFDs, (fd_set*) NULL, (fd_set*) NULL, &zeroTimeout));
1248
1249 // Currently we rebuild the entire interface list whenever any interface change is
1250 // detected. If this ever proves to be a performance issue in a multi-homed
1251 // configuration, more care should be paid to changedInterfaces.
1252 if (changedInterfaces)
1253 mDNSPlatformPosixRefreshInterfaceList(pChgRec->mDNS);
1254 }
1255
1256 // Register with either a Routing Socket or RtNetLink to listen for interface changes.
WatchForInterfaceChange(mDNS * const m)1257 mDNSlocal mStatus WatchForInterfaceChange(mDNS *const m)
1258 {
1259 mStatus err;
1260 IfChangeRec *pChgRec;
1261
1262 pChgRec = (IfChangeRec*) mDNSPlatformMemAllocate(sizeof *pChgRec);
1263 if (pChgRec == NULL)
1264 return mStatus_NoMemoryErr;
1265
1266 pChgRec->mDNS = m;
1267 err = OpenIfNotifySocket(&pChgRec->NotifySD);
1268 if (err == 0)
1269 err = mDNSPosixAddFDToEventLoop(pChgRec->NotifySD, InterfaceChangeCallback, pChgRec);
1270
1271 return err;
1272 }
1273
1274 // Test to see if we're the first client running on UDP port 5353, by trying to bind to 5353 without using SO_REUSEPORT.
1275 // If we fail, someone else got here first. That's not a big problem; we can share the port for multicast responses --
1276 // we just need to be aware that we shouldn't expect to successfully receive unicast UDP responses.
mDNSPlatformInit_CanReceiveUnicast(void)1277 mDNSlocal mDNSBool mDNSPlatformInit_CanReceiveUnicast(void)
1278 {
1279 int err;
1280 int s = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
1281 struct sockaddr_in s5353;
1282 s5353.sin_family = AF_INET;
1283 s5353.sin_port = MulticastDNSPort.NotAnInteger;
1284 s5353.sin_addr.s_addr = 0;
1285 err = bind(s, (struct sockaddr *)&s5353, sizeof(s5353));
1286 close(s);
1287 if (err) debugf("No unicast UDP responses");
1288 else debugf("Unicast UDP responses okay");
1289 return(err == 0);
1290 }
1291
1292 // mDNS core calls this routine to initialise the platform-specific data.
mDNSPlatformInit(mDNS * const m)1293 mDNSexport mStatus mDNSPlatformInit(mDNS *const m)
1294 {
1295 int err = 0;
1296 struct sockaddr sa;
1297 assert(m != NULL);
1298
1299 if (mDNSPlatformInit_CanReceiveUnicast()) m->CanReceiveUnicastOn5353 = mDNStrue;
1300
1301 // Tell mDNS core the names of this machine.
1302
1303 // Set up the nice label
1304 m->nicelabel.c[0] = 0;
1305 GetUserSpecifiedFriendlyComputerName(&m->nicelabel);
1306 if (m->nicelabel.c[0] == 0) MakeDomainLabelFromLiteralString(&m->nicelabel, "Computer");
1307
1308 // Set up the RFC 1034-compliant label
1309 m->hostlabel.c[0] = 0;
1310 GetUserSpecifiedRFC1034ComputerName(&m->hostlabel);
1311 if (m->hostlabel.c[0] == 0) MakeDomainLabelFromLiteralString(&m->hostlabel, "Computer");
1312
1313 mDNS_SetFQDN(m);
1314
1315 sa.sa_family = AF_INET;
1316 m->p->unicastSocket4 = -1;
1317 if (err == mStatus_NoError) err = SetupSocket(&sa, zeroIPPort, 0, &m->p->unicastSocket4);
1318 #if HAVE_IPV6
1319 sa.sa_family = AF_INET6;
1320 m->p->unicastSocket6 = -1;
1321 if (err == mStatus_NoError) err = SetupSocket(&sa, zeroIPPort, 0, &m->p->unicastSocket6);
1322 #endif
1323
1324 // Tell mDNS core about the network interfaces on this machine.
1325 if (err == mStatus_NoError) err = SetupInterfaceList(m);
1326
1327 // Tell mDNS core about DNS Servers
1328 mDNS_Lock(m);
1329 if (err == mStatus_NoError) ParseDNSServers(m, uDNS_SERVERS_FILE);
1330 mDNS_Unlock(m);
1331
1332 if (err == mStatus_NoError)
1333 {
1334 err = WatchForInterfaceChange(m);
1335 // Failure to observe interface changes is non-fatal.
1336 if (err != mStatus_NoError)
1337 {
1338 fprintf(stderr, "mDNS(%d) WARNING: Unable to detect interface changes (%d).\n", (int)getpid(), err);
1339 err = mStatus_NoError;
1340 }
1341 }
1342
1343 // We don't do asynchronous initialization on the Posix platform, so by the time
1344 // we get here the setup will already have succeeded or failed. If it succeeded,
1345 // we should just call mDNSCoreInitComplete() immediately.
1346 if (err == mStatus_NoError)
1347 mDNSCoreInitComplete(m, mStatus_NoError);
1348
1349 return PosixErrorToStatus(err);
1350 }
1351
1352 // mDNS core calls this routine to clean up the platform-specific data.
1353 // In our case all we need to do is to tear down every network interface.
mDNSPlatformClose(mDNS * const m)1354 mDNSexport void mDNSPlatformClose(mDNS *const m)
1355 {
1356 assert(m != NULL);
1357 ClearInterfaceList(m);
1358 if (m->p->unicastSocket4 != -1) assert(close(m->p->unicastSocket4) == 0);
1359 #if HAVE_IPV6
1360 if (m->p->unicastSocket6 != -1) assert(close(m->p->unicastSocket6) == 0);
1361 #endif
1362 }
1363
1364 // This is used internally by InterfaceChangeCallback.
1365 // It's also exported so that the Standalone Responder (mDNSResponderPosix)
1366 // can call it in response to a SIGHUP (mainly for debugging purposes).
mDNSPlatformPosixRefreshInterfaceList(mDNS * const m)1367 mDNSexport mStatus mDNSPlatformPosixRefreshInterfaceList(mDNS *const m)
1368 {
1369 int err;
1370 // This is a pretty heavyweight way to process interface changes --
1371 // destroying the entire interface list and then making fresh one from scratch.
1372 // We should make it like the OS X version, which leaves unchanged interfaces alone.
1373 ClearInterfaceList(m);
1374 err = SetupInterfaceList(m);
1375 return PosixErrorToStatus(err);
1376 }
1377
1378 #if COMPILER_LIKES_PRAGMA_MARK
1379 #pragma mark ***** Locking
1380 #endif
1381
1382 // On the Posix platform, locking is a no-op because we only ever enter
1383 // mDNS core on the main thread.
1384
1385 // mDNS core calls this routine when it wants to prevent
1386 // the platform from reentering mDNS core code.
mDNSPlatformLock(const mDNS * const m)1387 mDNSexport void mDNSPlatformLock (const mDNS *const m)
1388 {
1389 (void) m; // Unused
1390 }
1391
1392 // mDNS core calls this routine when it release the lock taken by
1393 // mDNSPlatformLock and allow the platform to reenter mDNS core code.
mDNSPlatformUnlock(const mDNS * const m)1394 mDNSexport void mDNSPlatformUnlock (const mDNS *const m)
1395 {
1396 (void) m; // Unused
1397 }
1398
1399 #if COMPILER_LIKES_PRAGMA_MARK
1400 #pragma mark ***** Strings
1401 #endif
1402
1403 // mDNS core calls this routine to copy C strings.
1404 // On the Posix platform this maps directly to the ANSI C strcpy.
mDNSPlatformStrCopy(void * dst,const void * src)1405 mDNSexport void mDNSPlatformStrCopy(void *dst, const void *src)
1406 {
1407 strcpy((char *)dst, (char *)src);
1408 }
1409
1410 // mDNS core calls this routine to get the length of a C string.
1411 // On the Posix platform this maps directly to the ANSI C strlen.
mDNSPlatformStrLen(const void * src)1412 mDNSexport mDNSu32 mDNSPlatformStrLen (const void *src)
1413 {
1414 return strlen((char*)src);
1415 }
1416
1417 // mDNS core calls this routine to copy memory.
1418 // On the Posix platform this maps directly to the ANSI C memcpy.
mDNSPlatformMemCopy(void * dst,const void * src,mDNSu32 len)1419 mDNSexport void mDNSPlatformMemCopy(void *dst, const void *src, mDNSu32 len)
1420 {
1421 memcpy(dst, src, len);
1422 }
1423
1424 // mDNS core calls this routine to test whether blocks of memory are byte-for-byte
1425 // identical. On the Posix platform this is a simple wrapper around ANSI C memcmp.
mDNSPlatformMemSame(const void * dst,const void * src,mDNSu32 len)1426 mDNSexport mDNSBool mDNSPlatformMemSame(const void *dst, const void *src, mDNSu32 len)
1427 {
1428 return memcmp(dst, src, len) == 0;
1429 }
1430
1431 // If the caller wants to know the exact return of memcmp, then use this instead
1432 // of mDNSPlatformMemSame
mDNSPlatformMemCmp(const void * dst,const void * src,mDNSu32 len)1433 mDNSexport int mDNSPlatformMemCmp(const void *dst, const void *src, mDNSu32 len)
1434 {
1435 return (memcmp(dst, src, len));
1436 }
1437
mDNSPlatformQsort(void * base,int nel,int width,int (* compar)(const void *,const void *))1438 mDNSexport void mDNSPlatformQsort(void *base, int nel, int width, int (*compar)(const void *, const void *))
1439 {
1440 (void)qsort(base, nel, width, compar);
1441 }
1442
1443 // DNSSEC stub functions
VerifySignature(mDNS * const m,DNSSECVerifier * dv,DNSQuestion * q)1444 mDNSexport void VerifySignature(mDNS *const m, DNSSECVerifier *dv, DNSQuestion *q)
1445 {
1446 (void)m;
1447 (void)dv;
1448 (void)q;
1449 }
1450
AddNSECSForCacheRecord(mDNS * const m,CacheRecord * crlist,CacheRecord * negcr,mDNSu8 rcode)1451 mDNSexport mDNSBool AddNSECSForCacheRecord(mDNS *const m, CacheRecord *crlist, CacheRecord *negcr, mDNSu8 rcode)
1452 {
1453 (void)m;
1454 (void)crlist;
1455 (void)negcr;
1456 (void)rcode;
1457 return mDNSfalse;
1458 }
1459
BumpDNSSECStats(mDNS * const m,DNSSECStatsAction action,DNSSECStatsType type,mDNSu32 value)1460 mDNSexport void BumpDNSSECStats(mDNS *const m, DNSSECStatsAction action, DNSSECStatsType type, mDNSu32 value)
1461 {
1462 (void)m;
1463 (void)action;
1464 (void)type;
1465 (void)value;
1466 }
1467
1468 // Proxy stub functions
DNSProxySetAttributes(DNSQuestion * q,DNSMessageHeader * h,DNSMessage * msg,mDNSu8 * ptr,mDNSu8 * limit)1469 mDNSexport mDNSu8 *DNSProxySetAttributes(DNSQuestion *q, DNSMessageHeader *h, DNSMessage *msg, mDNSu8 *ptr, mDNSu8 *limit)
1470 {
1471 (void) q;
1472 (void) h;
1473 (void) msg;
1474 (void) ptr;
1475 (void) limit;
1476
1477 return ptr;
1478 }
1479
DNSProxyInit(mDNS * const m,mDNSu32 IpIfArr[],mDNSu32 OpIf)1480 mDNSexport void DNSProxyInit(mDNS *const m, mDNSu32 IpIfArr[], mDNSu32 OpIf)
1481 {
1482 (void) m;
1483 (void) IpIfArr;
1484 (void) OpIf;
1485 }
1486
DNSProxyTerminate(mDNS * const m)1487 mDNSexport void DNSProxyTerminate(mDNS *const m)
1488 {
1489 (void) m;
1490 }
1491
1492 // mDNS core calls this routine to clear blocks of memory.
1493 // On the Posix platform this is a simple wrapper around ANSI C memset.
mDNSPlatformMemZero(void * dst,mDNSu32 len)1494 mDNSexport void mDNSPlatformMemZero(void *dst, mDNSu32 len)
1495 {
1496 memset(dst, 0, len);
1497 }
1498
mDNSPlatformMemAllocate(mDNSu32 len)1499 mDNSexport void * mDNSPlatformMemAllocate(mDNSu32 len) { return(malloc(len)); }
mDNSPlatformMemFree(void * mem)1500 mDNSexport void mDNSPlatformMemFree (void *mem) { free(mem); }
1501
mDNSPlatformRandomSeed(void)1502 mDNSexport mDNSu32 mDNSPlatformRandomSeed(void)
1503 {
1504 struct timeval tv;
1505 gettimeofday(&tv, NULL);
1506 return(tv.tv_usec);
1507 }
1508
1509 mDNSexport mDNSs32 mDNSPlatformOneSecond = 1024;
1510
mDNSPlatformTimeInit(void)1511 mDNSexport mStatus mDNSPlatformTimeInit(void)
1512 {
1513 // No special setup is required on Posix -- we just use gettimeofday();
1514 // This is not really safe, because gettimeofday can go backwards if the user manually changes the date or time
1515 // We should find a better way to do this
1516 return(mStatus_NoError);
1517 }
1518
mDNSPlatformRawTime()1519 mDNSexport mDNSs32 mDNSPlatformRawTime()
1520 {
1521 struct timeval tv;
1522 gettimeofday(&tv, NULL);
1523 // tv.tv_sec is seconds since 1st January 1970 (GMT, with no adjustment for daylight savings time)
1524 // tv.tv_usec is microseconds since the start of this second (i.e. values 0 to 999999)
1525 // We use the lower 22 bits of tv.tv_sec for the top 22 bits of our result
1526 // and we multiply tv.tv_usec by 16 / 15625 to get a value in the range 0-1023 to go in the bottom 10 bits.
1527 // This gives us a proper modular (cyclic) counter that has a resolution of roughly 1ms (actually 1/1024 second)
1528 // and correctly cycles every 2^22 seconds (4194304 seconds = approx 48 days).
1529 return((tv.tv_sec << 10) | (tv.tv_usec * 16 / 15625));
1530 }
1531
mDNSPlatformUTC(void)1532 mDNSexport mDNSs32 mDNSPlatformUTC(void)
1533 {
1534 return time(NULL);
1535 }
1536
mDNSPlatformSendWakeupPacket(mDNS * const m,mDNSInterfaceID InterfaceID,char * EthAddr,char * IPAddr,int iteration)1537 mDNSexport void mDNSPlatformSendWakeupPacket(mDNS *const m, mDNSInterfaceID InterfaceID, char *EthAddr, char *IPAddr, int iteration)
1538 {
1539 (void) m;
1540 (void) InterfaceID;
1541 (void) EthAddr;
1542 (void) IPAddr;
1543 (void) iteration;
1544 }
1545
mDNSPlatformValidRecordForInterface(AuthRecord * rr,const NetworkInterfaceInfo * intf)1546 mDNSexport mDNSBool mDNSPlatformValidRecordForInterface(AuthRecord *rr, const NetworkInterfaceInfo *intf)
1547 {
1548 (void) rr;
1549 (void) intf;
1550
1551 return 1;
1552 }
1553
mDNSPlatformValidQuestionForInterface(DNSQuestion * q,const NetworkInterfaceInfo * intf)1554 mDNSexport mDNSBool mDNSPlatformValidQuestionForInterface(DNSQuestion *q, const NetworkInterfaceInfo *intf)
1555 {
1556 (void) q;
1557 (void) intf;
1558
1559 return 1;
1560 }
1561
1562 // Used for debugging purposes. For now, just set the buffer to zero
mDNSPlatformFormatTime(unsigned long te,mDNSu8 * buf,int bufsize)1563 mDNSexport void mDNSPlatformFormatTime(unsigned long te, mDNSu8 *buf, int bufsize)
1564 {
1565 (void) te;
1566 if (bufsize) buf[0] = 0;
1567 }
1568
mDNSPlatformSendKeepalive(mDNSAddr * sadd,mDNSAddr * dadd,mDNSIPPort * lport,mDNSIPPort * rport,mDNSu32 seq,mDNSu32 ack,mDNSu16 win)1569 mDNSexport void mDNSPlatformSendKeepalive(mDNSAddr *sadd, mDNSAddr *dadd, mDNSIPPort *lport, mDNSIPPort *rport, mDNSu32 seq, mDNSu32 ack, mDNSu16 win)
1570 {
1571 (void) sadd; // Unused
1572 (void) dadd; // Unused
1573 (void) lport; // Unused
1574 (void) rport; // Unused
1575 (void) seq; // Unused
1576 (void) ack; // Unused
1577 (void) win; // Unused
1578 }
1579
mDNSPlatformRetrieveTCPInfo(mDNS * const m,mDNSAddr * laddr,mDNSIPPort * lport,mDNSAddr * raddr,mDNSIPPort * rport,mDNSTCPInfo * mti)1580 mDNSexport mStatus mDNSPlatformRetrieveTCPInfo(mDNS *const m, mDNSAddr *laddr, mDNSIPPort *lport, mDNSAddr *raddr, mDNSIPPort *rport, mDNSTCPInfo *mti)
1581 {
1582 (void) m; // Unused
1583 (void) laddr; // Unused
1584 (void) raddr; // Unused
1585 (void) lport; // Unused
1586 (void) rport; // Unused
1587 (void) mti; // Unused
1588
1589 return mStatus_NoError;
1590 }
1591
mDNSPlatformGetRemoteMacAddr(mDNS * const m,mDNSAddr * raddr)1592 mDNSexport mStatus mDNSPlatformGetRemoteMacAddr(mDNS *const m, mDNSAddr *raddr)
1593 {
1594 (void) raddr; // Unused
1595 (void) m; // Unused
1596
1597 return mStatus_NoError;
1598 }
1599
mDNSPlatformStoreSPSMACAddr(mDNSAddr * spsaddr,char * ifname)1600 mDNSexport mStatus mDNSPlatformStoreSPSMACAddr(mDNSAddr *spsaddr, char *ifname)
1601 {
1602 (void) spsaddr; // Unused
1603 (void) ifname; // Unused
1604
1605 return mStatus_NoError;
1606 }
1607
mDNSPlatformClearSPSMACAddr(void)1608 mDNSexport mStatus mDNSPlatformClearSPSMACAddr(void)
1609 {
1610 return mStatus_NoError;
1611 }
1612
mDNSPlatformGetUDPPort(UDPSocket * sock)1613 mDNSexport mDNSu16 mDNSPlatformGetUDPPort(UDPSocket *sock)
1614 {
1615 (void) sock; // unused
1616
1617 return (mDNSu16)-1;
1618 }
1619
mDNSPlatformInterfaceIsD2D(mDNSInterfaceID InterfaceID)1620 mDNSexport mDNSBool mDNSPlatformInterfaceIsD2D(mDNSInterfaceID InterfaceID)
1621 {
1622 (void) InterfaceID; // unused
1623
1624 return mDNSfalse;
1625 }
1626
mDNSPlatformAllowPID(mDNS * const m,DNSQuestion * q)1627 mDNSexport mDNSBool mDNSPlatformAllowPID(mDNS *const m, DNSQuestion *q)
1628 {
1629 (void) m;
1630 (void) q;
1631 return mDNStrue;
1632 }
1633
mDNSPlatformGetServiceID(mDNS * const m,DNSQuestion * q)1634 mDNSexport mDNSs32 mDNSPlatformGetServiceID(mDNS *const m, DNSQuestion *q)
1635 {
1636 (void) m;
1637 (void) q;
1638 return -1;
1639 }
1640
mDNSPlatformSetDelegatePID(UDPSocket * src,const mDNSAddr * dst,DNSQuestion * q)1641 mDNSexport void mDNSPlatformSetDelegatePID(UDPSocket *src, const mDNSAddr *dst, DNSQuestion *q)
1642 {
1643 (void) src;
1644 (void) dst;
1645 (void) q;
1646 }
1647
mDNSPlatformGetPID()1648 mDNSexport mDNSs32 mDNSPlatformGetPID()
1649 {
1650 return 0;
1651 }
1652
mDNSPosixAddToFDSet(int * nfds,fd_set * readfds,int s)1653 mDNSlocal void mDNSPosixAddToFDSet(int *nfds, fd_set *readfds, int s)
1654 {
1655 if (*nfds < s + 1) *nfds = s + 1;
1656 FD_SET(s, readfds);
1657 }
1658
mDNSPosixGetFDSet(mDNS * m,int * nfds,fd_set * readfds,struct timeval * timeout)1659 mDNSexport void mDNSPosixGetFDSet(mDNS *m, int *nfds, fd_set *readfds, struct timeval *timeout)
1660 {
1661 mDNSs32 ticks;
1662 struct timeval interval;
1663
1664 // 1. Call mDNS_Execute() to let mDNSCore do what it needs to do
1665 mDNSs32 nextevent = mDNS_Execute(m);
1666
1667 // 2. Build our list of active file descriptors
1668 PosixNetworkInterface *info = (PosixNetworkInterface *)(m->HostInterfaces);
1669 if (m->p->unicastSocket4 != -1) mDNSPosixAddToFDSet(nfds, readfds, m->p->unicastSocket4);
1670 #if HAVE_IPV6
1671 if (m->p->unicastSocket6 != -1) mDNSPosixAddToFDSet(nfds, readfds, m->p->unicastSocket6);
1672 #endif
1673 while (info)
1674 {
1675 if (info->multicastSocket4 != -1) mDNSPosixAddToFDSet(nfds, readfds, info->multicastSocket4);
1676 #if HAVE_IPV6
1677 if (info->multicastSocket6 != -1) mDNSPosixAddToFDSet(nfds, readfds, info->multicastSocket6);
1678 #endif
1679 info = (PosixNetworkInterface *)(info->coreIntf.next);
1680 }
1681
1682 // 3. Calculate the time remaining to the next scheduled event (in struct timeval format)
1683 ticks = nextevent - mDNS_TimeNow(m);
1684 if (ticks < 1) ticks = 1;
1685 interval.tv_sec = ticks >> 10; // The high 22 bits are seconds
1686 interval.tv_usec = ((ticks & 0x3FF) * 15625) / 16; // The low 10 bits are 1024ths
1687
1688 // 4. If client's proposed timeout is more than what we want, then reduce it
1689 if (timeout->tv_sec > interval.tv_sec ||
1690 (timeout->tv_sec == interval.tv_sec && timeout->tv_usec > interval.tv_usec))
1691 *timeout = interval;
1692 }
1693
mDNSPosixProcessFDSet(mDNS * const m,fd_set * readfds)1694 mDNSexport void mDNSPosixProcessFDSet(mDNS *const m, fd_set *readfds)
1695 {
1696 PosixNetworkInterface *info;
1697 assert(m != NULL);
1698 assert(readfds != NULL);
1699 info = (PosixNetworkInterface *)(m->HostInterfaces);
1700
1701 if (m->p->unicastSocket4 != -1 && FD_ISSET(m->p->unicastSocket4, readfds))
1702 {
1703 FD_CLR(m->p->unicastSocket4, readfds);
1704 SocketDataReady(m, NULL, m->p->unicastSocket4);
1705 }
1706 #if HAVE_IPV6
1707 if (m->p->unicastSocket6 != -1 && FD_ISSET(m->p->unicastSocket6, readfds))
1708 {
1709 FD_CLR(m->p->unicastSocket6, readfds);
1710 SocketDataReady(m, NULL, m->p->unicastSocket6);
1711 }
1712 #endif
1713
1714 while (info)
1715 {
1716 if (info->multicastSocket4 != -1 && FD_ISSET(info->multicastSocket4, readfds))
1717 {
1718 FD_CLR(info->multicastSocket4, readfds);
1719 SocketDataReady(m, info, info->multicastSocket4);
1720 }
1721 #if HAVE_IPV6
1722 if (info->multicastSocket6 != -1 && FD_ISSET(info->multicastSocket6, readfds))
1723 {
1724 FD_CLR(info->multicastSocket6, readfds);
1725 SocketDataReady(m, info, info->multicastSocket6);
1726 }
1727 #endif
1728 info = (PosixNetworkInterface *)(info->coreIntf.next);
1729 }
1730 }
1731
1732 // update gMaxFD
DetermineMaxEventFD(void)1733 mDNSlocal void DetermineMaxEventFD(void)
1734 {
1735 PosixEventSource *iSource;
1736
1737 gMaxFD = 0;
1738 for (iSource=(PosixEventSource*)gEventSources.Head; iSource; iSource = iSource->Next)
1739 if (gMaxFD < iSource->fd)
1740 gMaxFD = iSource->fd;
1741 }
1742
1743 // Add a file descriptor to the set that mDNSPosixRunEventLoopOnce() listens to.
mDNSPosixAddFDToEventLoop(int fd,mDNSPosixEventCallback callback,void * context)1744 mStatus mDNSPosixAddFDToEventLoop(int fd, mDNSPosixEventCallback callback, void *context)
1745 {
1746 PosixEventSource *newSource;
1747
1748 if (gEventSources.LinkOffset == 0)
1749 InitLinkedList(&gEventSources, offsetof(PosixEventSource, Next));
1750
1751 if (fd >= (int) FD_SETSIZE || fd < 0)
1752 return mStatus_UnsupportedErr;
1753 if (callback == NULL)
1754 return mStatus_BadParamErr;
1755
1756 newSource = (PosixEventSource*) malloc(sizeof *newSource);
1757 if (NULL == newSource)
1758 return mStatus_NoMemoryErr;
1759
1760 newSource->Callback = callback;
1761 newSource->Context = context;
1762 newSource->fd = fd;
1763
1764 AddToTail(&gEventSources, newSource);
1765 FD_SET(fd, &gEventFDs);
1766
1767 DetermineMaxEventFD();
1768
1769 return mStatus_NoError;
1770 }
1771
1772 // Remove a file descriptor from the set that mDNSPosixRunEventLoopOnce() listens to.
mDNSPosixRemoveFDFromEventLoop(int fd)1773 mStatus mDNSPosixRemoveFDFromEventLoop(int fd)
1774 {
1775 PosixEventSource *iSource;
1776
1777 for (iSource=(PosixEventSource*)gEventSources.Head; iSource; iSource = iSource->Next)
1778 {
1779 if (fd == iSource->fd)
1780 {
1781 FD_CLR(fd, &gEventFDs);
1782 RemoveFromList(&gEventSources, iSource);
1783 free(iSource);
1784 DetermineMaxEventFD();
1785 return mStatus_NoError;
1786 }
1787 }
1788 return mStatus_NoSuchNameErr;
1789 }
1790
1791 // Simply note the received signal in gEventSignals.
NoteSignal(int signum)1792 mDNSlocal void NoteSignal(int signum)
1793 {
1794 sigaddset(&gEventSignals, signum);
1795 }
1796
1797 // Tell the event package to listen for signal and report it in mDNSPosixRunEventLoopOnce().
mDNSPosixListenForSignalInEventLoop(int signum)1798 mStatus mDNSPosixListenForSignalInEventLoop(int signum)
1799 {
1800 struct sigaction action;
1801 mStatus err;
1802
1803 mDNSPlatformMemZero(&action, sizeof action); // more portable than member-wise assignment
1804 action.sa_handler = NoteSignal;
1805 err = sigaction(signum, &action, (struct sigaction*) NULL);
1806
1807 sigaddset(&gEventSignalSet, signum);
1808
1809 return err;
1810 }
1811
1812 // Tell the event package to stop listening for signal in mDNSPosixRunEventLoopOnce().
mDNSPosixIgnoreSignalInEventLoop(int signum)1813 mStatus mDNSPosixIgnoreSignalInEventLoop(int signum)
1814 {
1815 struct sigaction action;
1816 mStatus err;
1817
1818 mDNSPlatformMemZero(&action, sizeof action); // more portable than member-wise assignment
1819 action.sa_handler = SIG_DFL;
1820 err = sigaction(signum, &action, (struct sigaction*) NULL);
1821
1822 sigdelset(&gEventSignalSet, signum);
1823
1824 return err;
1825 }
1826
1827 // Do a single pass through the attendent event sources and dispatch any found to their callbacks.
1828 // Return as soon as internal timeout expires, or a signal we're listening for is received.
mDNSPosixRunEventLoopOnce(mDNS * m,const struct timeval * pTimeout,sigset_t * pSignalsReceived,mDNSBool * pDataDispatched)1829 mStatus mDNSPosixRunEventLoopOnce(mDNS *m, const struct timeval *pTimeout,
1830 sigset_t *pSignalsReceived, mDNSBool *pDataDispatched)
1831 {
1832 fd_set listenFDs = gEventFDs;
1833 int fdMax = 0, numReady;
1834 struct timeval timeout = *pTimeout;
1835
1836 // Include the sockets that are listening to the wire in our select() set
1837 mDNSPosixGetFDSet(m, &fdMax, &listenFDs, &timeout); // timeout may get modified
1838 if (fdMax < gMaxFD)
1839 fdMax = gMaxFD;
1840
1841 numReady = select(fdMax + 1, &listenFDs, (fd_set*) NULL, (fd_set*) NULL, &timeout);
1842
1843 // If any data appeared, invoke its callback
1844 if (numReady > 0)
1845 {
1846 PosixEventSource *iSource;
1847
1848 (void) mDNSPosixProcessFDSet(m, &listenFDs); // call this first to process wire data for clients
1849
1850 for (iSource=(PosixEventSource*)gEventSources.Head; iSource; iSource = iSource->Next)
1851 {
1852 if (FD_ISSET(iSource->fd, &listenFDs))
1853 {
1854 iSource->Callback(iSource->fd, 0, iSource->Context);
1855 break; // in case callback removed elements from gEventSources
1856 }
1857 }
1858 *pDataDispatched = mDNStrue;
1859 }
1860 else
1861 *pDataDispatched = mDNSfalse;
1862
1863 (void) sigprocmask(SIG_BLOCK, &gEventSignalSet, (sigset_t*) NULL);
1864 *pSignalsReceived = gEventSignals;
1865 sigemptyset(&gEventSignals);
1866 (void) sigprocmask(SIG_UNBLOCK, &gEventSignalSet, (sigset_t*) NULL);
1867
1868 return mStatus_NoError;
1869 }
1870