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1 /* -*- Mode: C; tab-width: 4 -*-
2  *
3  * Copyright (c) 2003-2004, Apple Computer, Inc. All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions are met:
7  *
8  * 1.  Redistributions of source code must retain the above copyright notice,
9  *     this list of conditions and the following disclaimer.
10  * 2.  Redistributions in binary form must reproduce the above copyright notice,
11  *     this list of conditions and the following disclaimer in the documentation
12  *     and/or other materials provided with the distribution.
13  * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of its
14  *     contributors may be used to endorse or promote products derived from this
15  *     software without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
18  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
19  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
20  * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
21  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
22  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
23  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
24  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
26  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 #include <errno.h>
30 #include <stdlib.h>
31 
32 #include "dnssd_ipc.h"
33 
34 static int gDaemonErr = kDNSServiceErr_NoError;
35 
36 #if defined(_WIN32)
37 
38 	#define _SSIZE_T
39 	#include <CommonServices.h>
40 	#include <DebugServices.h>
41 	#include <winsock2.h>
42 	#include <ws2tcpip.h>
43 	#include <windows.h>
44 	#include <stdarg.h>
45 
46 	#define sockaddr_mdns sockaddr_in
47 	#define AF_MDNS AF_INET
48 
49 	// Disable warning: "'type cast' : from data pointer 'void *' to function pointer"
50 	#pragma warning(disable:4055)
51 
52 	// Disable warning: "nonstandard extension, function/data pointer conversion in expression"
53 	#pragma warning(disable:4152)
54 
55 	extern BOOL IsSystemServiceDisabled();
56 
57 	#define sleep(X) Sleep((X) * 1000)
58 
59 	static int g_initWinsock = 0;
60 	#define LOG_WARNING kDebugLevelWarning
61 	#define LOG_INFO kDebugLevelInfo
syslog(int priority,const char * message,...)62 	static void syslog( int priority, const char * message, ...)
63 		{
64 		va_list args;
65 		int len;
66 		char * buffer;
67 		DWORD err = WSAGetLastError();
68 		(void) priority;
69 		va_start( args, message );
70 		len = _vscprintf( message, args ) + 1;
71 		buffer = malloc( len * sizeof(char) );
72 		if ( buffer ) { vsprintf( buffer, message, args ); OutputDebugString( buffer ); free( buffer ); }
73 		WSASetLastError( err );
74 		}
75 #else
76 #ifndef __ANDROID__
77 	#include <sys/fcntl.h>		// For O_RDWR etc.
78 #else
79 	#include <fcntl.h>
80 	#define LOG_TAG "libmdnsd"
81 #endif
82 	#include <sys/time.h>
83 	#include <sys/socket.h>
84 	#include <syslog.h>
85 
86 	#define sockaddr_mdns sockaddr_un
87 	#define AF_MDNS AF_LOCAL
88 
89 #endif
90 
91 // <rdar://problem/4096913> Specifies how many times we'll try and connect to the server.
92 
93 #define DNSSD_CLIENT_MAXTRIES 4
94 
95 // Uncomment the line below to use the old error return mechanism of creating a temporary named socket (e.g. in /var/tmp)
96 //#define USE_NAMED_ERROR_RETURN_SOCKET 1
97 
98 #define DNSSD_CLIENT_TIMEOUT 10  // In seconds
99 
100 #ifndef CTL_PATH_PREFIX
101 #define CTL_PATH_PREFIX "/var/tmp/dnssd_result_socket."
102 #endif
103 
104 typedef struct
105 	{
106 	ipc_msg_hdr         ipc_hdr;
107 	DNSServiceFlags     cb_flags;
108 	uint32_t            cb_interface;
109 	DNSServiceErrorType cb_err;
110 	} CallbackHeader;
111 
112 typedef struct _DNSServiceRef_t DNSServiceOp;
113 typedef struct _DNSRecordRef_t DNSRecord;
114 
115 // client stub callback to process message from server and deliver results to client application
116 typedef void (*ProcessReplyFn)(DNSServiceOp *const sdr, const CallbackHeader *const cbh, const char *msg, const char *const end);
117 
118 #define ValidatorBits 0x12345678
119 #define DNSServiceRefValid(X) (dnssd_SocketValid((X)->sockfd) && (((X)->sockfd ^ (X)->validator) == ValidatorBits))
120 
121 // When using kDNSServiceFlagsShareConnection, there is one primary _DNSServiceOp_t, and zero or more subordinates
122 // For the primary, the 'next' field points to the first subordinate, and its 'next' field points to the next, and so on.
123 // For the primary, the 'primary' field is NULL; for subordinates the 'primary' field points back to the associated primary
124 //
125 // _DNS_SD_LIBDISPATCH is defined where libdispatch/GCD is available. This does not mean that the application will use the
126 // DNSServiceSetDispatchQueue API. Hence any new code guarded with _DNS_SD_LIBDISPATCH should still be backwards compatible.
127 struct _DNSServiceRef_t
128 	{
129 	DNSServiceOp     *next;				// For shared connection
130 	DNSServiceOp     *primary;			// For shared connection
131 	dnssd_sock_t      sockfd;			// Connected socket between client and daemon
132 	dnssd_sock_t      validator;		// Used to detect memory corruption, double disposals, etc.
133 	client_context_t  uid;				// For shared connection requests, each subordinate DNSServiceRef has its own ID,
134 										// unique within the scope of the same shared parent DNSServiceRef
135 	uint32_t          op;				// request_op_t or reply_op_t
136 	uint32_t          max_index;		// Largest assigned record index - 0 if no additional records registered
137 	uint32_t          logcounter;		// Counter used to control number of syslog messages we write
138 	int              *moreptr;			// Set while DNSServiceProcessResult working on this particular DNSServiceRef
139 	ProcessReplyFn    ProcessReply;		// Function pointer to the code to handle received messages
140 	void             *AppCallback;		// Client callback function and context
141 	void             *AppContext;
142 	DNSRecord        *rec;
143 #if _DNS_SD_LIBDISPATCH
144 	dispatch_source_t disp_source;
145 	dispatch_queue_t  disp_queue;
146 #endif
147 	};
148 
149 struct _DNSRecordRef_t
150 	{
151 	DNSRecord		*recnext;
152 	void *AppContext;
153 	DNSServiceRegisterRecordReply AppCallback;
154 	DNSRecordRef recref;
155 	uint32_t record_index;  // index is unique to the ServiceDiscoveryRef
156 	DNSServiceOp *sdr;
157 	};
158 
159 // Write len bytes. Return 0 on success, -1 on error
write_all(dnssd_sock_t sd,char * buf,size_t len)160 static int write_all(dnssd_sock_t sd, char *buf, size_t len)
161 	{
162 	// Don't use "MSG_WAITALL"; it returns "Invalid argument" on some Linux versions; use an explicit while() loop instead.
163 	//if (send(sd, buf, len, MSG_WAITALL) != len) return -1;
164 	while (len)
165 		{
166 		ssize_t num_written = send(sd, buf, (long)len, 0);
167 		if (num_written < 0 || (size_t)num_written > len)
168 			{
169 			// Should never happen. If it does, it indicates some OS bug,
170 			// or that the mDNSResponder daemon crashed (which should never happen).
171 			#if !defined(__ppc__) && defined(SO_ISDEFUNCT)
172 			int defunct;
173 			socklen_t dlen = sizeof (defunct);
174 			if (getsockopt(sd, SOL_SOCKET, SO_ISDEFUNCT, &defunct, &dlen) < 0)
175 				syslog(LOG_WARNING, "dnssd_clientstub write_all: SO_ISDEFUNCT failed %d %s", dnssd_errno, dnssd_strerror(dnssd_errno));
176 			if (!defunct)
177 				syslog(LOG_WARNING, "dnssd_clientstub write_all(%d) failed %ld/%ld %d %s", sd,
178 					(long)num_written, (long)len,
179 					(num_written < 0) ? dnssd_errno                 : 0,
180 					(num_written < 0) ? dnssd_strerror(dnssd_errno) : "");
181 			else
182 				syslog(LOG_INFO, "dnssd_clientstub write_all(%d) DEFUNCT", sd);
183 			#else
184 			syslog(LOG_WARNING, "dnssd_clientstub write_all(%d) failed %ld/%ld %d %s", sd,
185 				(long)num_written, (long)len,
186 				(num_written < 0) ? dnssd_errno                 : 0,
187 				(num_written < 0) ? dnssd_strerror(dnssd_errno) : "");
188 			#endif
189 			return -1;
190 			}
191 		buf += num_written;
192 		len -= num_written;
193 		}
194 	return 0;
195 	}
196 
197 enum { read_all_success = 0, read_all_fail = -1, read_all_wouldblock = -2 };
198 
199 // Read len bytes. Return 0 on success, read_all_fail on error, or read_all_wouldblock for
read_all(dnssd_sock_t sd,char * buf,int len)200 static int read_all(dnssd_sock_t sd, char *buf, int len)
201 	{
202 	// Don't use "MSG_WAITALL"; it returns "Invalid argument" on some Linux versions; use an explicit while() loop instead.
203 	//if (recv(sd, buf, len, MSG_WAITALL) != len) return -1;
204 
205 	while (len)
206 		{
207 		ssize_t num_read = recv(sd, buf, len, 0);
208 		// It is valid to get an interrupted system call error e.g., somebody attaching
209 		// in a debugger, retry without failing
210 		if ((num_read < 0) && (errno == EINTR)) { syslog(LOG_INFO, "dnssd_clientstub read_all: EINTR continue"); continue; }
211 		if ((num_read == 0) || (num_read < 0) || (num_read > len))
212 			{
213 			int printWarn = 0;
214 			int defunct = 0;
215 			// Should never happen. If it does, it indicates some OS bug,
216 			// or that the mDNSResponder daemon crashed (which should never happen).
217 #if defined(WIN32)
218 			// <rdar://problem/7481776> Suppress logs for "A non-blocking socket operation
219 			//                          could not be completed immediately"
220 			if (WSAGetLastError() != WSAEWOULDBLOCK)
221 				printWarn = 1;
222 #endif
223 #if !defined(__ppc__) && defined(SO_ISDEFUNCT)
224 			{
225 			socklen_t dlen = sizeof (defunct);
226 			if (getsockopt(sd, SOL_SOCKET, SO_ISDEFUNCT, &defunct, &dlen) < 0)
227 				syslog(LOG_WARNING, "dnssd_clientstub read_all: SO_ISDEFUNCT failed %d %s", dnssd_errno, dnssd_strerror(dnssd_errno));
228 			}
229 			if (!defunct)
230 				printWarn = 1;
231 #endif
232 			if (printWarn)
233 				syslog(LOG_WARNING, "dnssd_clientstub read_all(%d) failed %ld/%ld %d %s", sd,
234 					(long)num_read, (long)len,
235 					(num_read < 0) ? dnssd_errno                 : 0,
236 					(num_read < 0) ? dnssd_strerror(dnssd_errno) : "");
237 			else if (defunct)
238 				syslog(LOG_INFO, "dnssd_clientstub read_all(%d) DEFUNCT", sd);
239 			return (num_read < 0 && dnssd_errno == dnssd_EWOULDBLOCK) ? read_all_wouldblock : read_all_fail;
240 			}
241 		buf += num_read;
242 		len -= num_read;
243 		}
244 	return read_all_success;
245 	}
246 
247 // Returns 1 if more bytes remain to be read on socket descriptor sd, 0 otherwise
more_bytes(dnssd_sock_t sd)248 static int more_bytes(dnssd_sock_t sd)
249 	{
250 	struct timeval tv = { 0, 0 };
251 	fd_set readfds;
252 	fd_set *fs;
253 	int ret;
254 
255 	if (sd < FD_SETSIZE)
256 		{
257 		fs = &readfds;
258 		FD_ZERO(fs);
259 		}
260 	else
261 		{
262 		// Compute the number of integers needed for storing "sd". Internally fd_set is stored
263 		// as an array of ints with one bit for each fd and hence we need to compute
264 		// the number of ints needed rather than the number of bytes. If "sd" is 32, we need
265 		// two ints and not just one.
266 		int nfdbits = sizeof (int) * 8;
267 		int nints = (sd/nfdbits) + 1;
268 		fs = (fd_set *)calloc(nints, sizeof(int));
269 		if (fs == NULL) { syslog(LOG_WARNING, "dnssd_clientstub more_bytes: malloc failed"); return 0; }
270 		}
271 	FD_SET(sd, fs);
272 	ret = select((int)sd+1, fs, (fd_set*)NULL, (fd_set*)NULL, &tv);
273 	if (fs != &readfds) free(fs);
274 	return (ret > 0);
275 	}
276 
277 // Wait for daemon to write to socket
wait_for_daemon(dnssd_sock_t sock,int timeout)278 static int wait_for_daemon(dnssd_sock_t sock, int timeout)
279 	{
280 #ifndef WIN32
281 	// At this point the next operation (accept() or read()) on this socket may block for a few milliseconds waiting
282 	// for the daemon to respond, but that's okay -- the daemon is a trusted service and we know if won't take more
283 	// than a few milliseconds to respond.  So we'll forego checking for readability of the socket.
284 	(void) sock;
285 	(void) timeout;
286 #else
287 	// Windows on the other hand suffers from 3rd party software (primarily 3rd party firewall software) that
288 	// interferes with proper functioning of the TCP protocol stack. Because of this and because we depend on TCP
289 	// to communicate with the system service, we want to make sure that the next operation on this socket (accept() or
290 	// read()) doesn't block indefinitely.
291 	if (!gDaemonErr)
292 		{
293 		struct timeval tv;
294 		fd_set set;
295 
296 		FD_ZERO(&set);
297 		FD_SET(sock, &set);
298 		tv.tv_sec = timeout;
299 		tv.tv_usec = 0;
300 		if (!select((int)(sock + 1), &set, NULL, NULL, &tv))
301 			{
302 				syslog(LOG_WARNING, "dnssd_clientstub wait_for_daemon timed out");
303 				gDaemonErr = kDNSServiceErr_Timeout;
304 			}
305 		}
306 #endif
307 	return gDaemonErr;
308 	}
309 
310 /* create_hdr
311  *
312  * allocate and initialize an ipc message header. Value of len should initially be the
313  * length of the data, and is set to the value of the data plus the header. data_start
314  * is set to point to the beginning of the data section. SeparateReturnSocket should be
315  * non-zero for calls that can't receive an immediate error return value on their primary
316  * socket, and therefore require a separate return path for the error code result.
317  * if zero, the path to a control socket is appended at the beginning of the message buffer.
318  * data_start is set past this string.
319  */
create_hdr(uint32_t op,size_t * len,char ** data_start,int SeparateReturnSocket,DNSServiceOp * ref)320 static ipc_msg_hdr *create_hdr(uint32_t op, size_t *len, char **data_start, int SeparateReturnSocket, DNSServiceOp *ref)
321 	{
322 	char *msg = NULL;
323 	ipc_msg_hdr *hdr;
324 	int datalen;
325 #if !defined(USE_TCP_LOOPBACK)
326 	char ctrl_path[64] = "";	// "/var/tmp/dnssd_result_socket.xxxxxxxxxx-xxx-xxxxxx"
327 #endif
328 
329 	if (SeparateReturnSocket)
330 		{
331 #if defined(USE_TCP_LOOPBACK)
332 		*len += 2;  // Allocate space for two-byte port number
333 #elif defined(USE_NAMED_ERROR_RETURN_SOCKET)
334 		struct timeval tv;
335 		if (gettimeofday(&tv, NULL) < 0)
336 			{ syslog(LOG_WARNING, "dnssd_clientstub create_hdr: gettimeofday failed %d %s", dnssd_errno, dnssd_strerror(dnssd_errno)); return NULL; }
337 		sprintf(ctrl_path, "%s%d-%.3lx-%.6lu", CTL_PATH_PREFIX, (int)getpid(),
338 			(unsigned long)(tv.tv_sec & 0xFFF), (unsigned long)(tv.tv_usec));
339 		*len += strlen(ctrl_path) + 1;
340 #else
341 		*len += 1;		// Allocate space for single zero byte (empty C string)
342 #endif
343 		}
344 
345 	datalen = (int) *len;
346 	*len += sizeof(ipc_msg_hdr);
347 
348 	// Write message to buffer
349 	msg = malloc(*len);
350 	if (!msg) { syslog(LOG_WARNING, "dnssd_clientstub create_hdr: malloc failed"); return NULL; }
351 
352 	memset(msg, 0, *len);
353 	hdr = (ipc_msg_hdr *)msg;
354 	hdr->version                = VERSION;
355 	hdr->datalen                = datalen;
356 	hdr->ipc_flags              = 0;
357 	hdr->op                     = op;
358 	hdr->client_context         = ref->uid;
359 	hdr->reg_index              = 0;
360 	*data_start = msg + sizeof(ipc_msg_hdr);
361 #if defined(USE_TCP_LOOPBACK)
362 	// Put dummy data in for the port, since we don't know what it is yet.
363 	// The data will get filled in before we send the message. This happens in deliver_request().
364 	if (SeparateReturnSocket) put_uint16(0, data_start);
365 #else
366 	if (SeparateReturnSocket) put_string(ctrl_path, data_start);
367 #endif
368 	return hdr;
369 	}
370 
FreeDNSRecords(DNSServiceOp * sdRef)371 static void FreeDNSRecords(DNSServiceOp *sdRef)
372 	{
373 	DNSRecord *rec = sdRef->rec;
374 	while (rec)
375 		{
376 		DNSRecord *next = rec->recnext;
377 		free(rec);
378 		rec = next;
379 		}
380 	}
381 
FreeDNSServiceOp(DNSServiceOp * x)382 static void FreeDNSServiceOp(DNSServiceOp *x)
383 	{
384 	// We don't use our DNSServiceRefValid macro here because if we're cleaning up after a socket() call failed
385 	// then sockfd could legitimately contain a failing value (e.g. dnssd_InvalidSocket)
386 	if ((x->sockfd ^ x->validator) != ValidatorBits)
387 		syslog(LOG_WARNING, "dnssd_clientstub attempt to dispose invalid DNSServiceRef %p %08X %08X", x, x->sockfd, x->validator);
388 	else
389 		{
390 		x->next         = NULL;
391 		x->primary      = NULL;
392 		x->sockfd       = dnssd_InvalidSocket;
393 		x->validator    = 0xDDDDDDDD;
394 		x->op           = request_op_none;
395 		x->max_index    = 0;
396 		x->logcounter   = 0;
397 		x->moreptr      = NULL;
398 		x->ProcessReply = NULL;
399 		x->AppCallback  = NULL;
400 		x->AppContext   = NULL;
401 #if _DNS_SD_LIBDISPATCH
402 		if (x->disp_source)	dispatch_release(x->disp_source);
403 		x->disp_source  = NULL;
404 		x->disp_queue   = NULL;
405 #endif
406 		// DNSRecords may have been added to subordinate sdRef e.g., DNSServiceRegister/DNSServiceAddRecord
407 		// or on the main sdRef e.g., DNSServiceCreateConnection/DNSServiveRegisterRecord. DNSRecords may have
408 		// been freed if the application called DNSRemoveRecord
409 		FreeDNSRecords(x);
410 		free(x);
411 		}
412 	}
413 
414 // Return a connected service ref (deallocate with DNSServiceRefDeallocate)
ConnectToServer(DNSServiceRef * ref,DNSServiceFlags flags,uint32_t op,ProcessReplyFn ProcessReply,void * AppCallback,void * AppContext)415 static DNSServiceErrorType ConnectToServer(DNSServiceRef *ref, DNSServiceFlags flags, uint32_t op, ProcessReplyFn ProcessReply, void *AppCallback, void *AppContext)
416 	{
417 	#if APPLE_OSX_mDNSResponder
418 	int NumTries = DNSSD_CLIENT_MAXTRIES;
419 	#else
420 	int NumTries = 0;
421 	#endif
422 
423 	dnssd_sockaddr_t saddr;
424 	DNSServiceOp *sdr;
425 
426 	if (!ref) { syslog(LOG_WARNING, "dnssd_clientstub DNSService operation with NULL DNSServiceRef"); return kDNSServiceErr_BadParam; }
427 
428 	if (flags & kDNSServiceFlagsShareConnection)
429 		{
430 		if (!*ref)
431 			{
432 			syslog(LOG_WARNING, "dnssd_clientstub kDNSServiceFlagsShareConnection used with NULL DNSServiceRef");
433 			return kDNSServiceErr_BadParam;
434 			}
435 		if (!DNSServiceRefValid(*ref) || (*ref)->op != connection_request || (*ref)->primary)
436 			{
437 			syslog(LOG_WARNING, "dnssd_clientstub kDNSServiceFlagsShareConnection used with invalid DNSServiceRef %p %08X %08X",
438 				(*ref), (*ref)->sockfd, (*ref)->validator);
439 			*ref = NULL;
440 			return kDNSServiceErr_BadReference;
441 			}
442 		}
443 
444 	#if defined(_WIN32)
445 	if (!g_initWinsock)
446 		{
447 		WSADATA wsaData;
448 		g_initWinsock = 1;
449 		if (WSAStartup(MAKEWORD(2,2), &wsaData) != 0) { *ref = NULL; return kDNSServiceErr_ServiceNotRunning; }
450 		}
451 	// <rdar://problem/4096913> If the system service is disabled, we only want to try to connect once
452 	if (IsSystemServiceDisabled()) NumTries = DNSSD_CLIENT_MAXTRIES;
453 	#endif
454 
455 	sdr = malloc(sizeof(DNSServiceOp));
456 	if (!sdr) { syslog(LOG_WARNING, "dnssd_clientstub ConnectToServer: malloc failed"); *ref = NULL; return kDNSServiceErr_NoMemory; }
457 	sdr->next          = NULL;
458 	sdr->primary       = NULL;
459 	sdr->sockfd        = dnssd_InvalidSocket;
460 	sdr->validator     = sdr->sockfd ^ ValidatorBits;
461 	sdr->op            = op;
462 	sdr->max_index     = 0;
463 	sdr->logcounter    = 0;
464 	sdr->moreptr       = NULL;
465 	sdr->uid.u32[0]    = 0;
466 	sdr->uid.u32[1]    = 0;
467 	sdr->ProcessReply  = ProcessReply;
468 	sdr->AppCallback   = AppCallback;
469 	sdr->AppContext    = AppContext;
470 	sdr->rec           = NULL;
471 #if _DNS_SD_LIBDISPATCH
472 	sdr->disp_source   = NULL;
473 	sdr->disp_queue    = NULL;
474 #endif
475 
476 	if (flags & kDNSServiceFlagsShareConnection)
477 		{
478 		DNSServiceOp **p = &(*ref)->next;		// Append ourselves to end of primary's list
479 		while (*p) p = &(*p)->next;
480 		*p = sdr;
481 		// Preincrement counter before we use it -- it helps with debugging if we know the all-zeroes ID should never appear
482 		if (++(*ref)->uid.u32[0] == 0) ++(*ref)->uid.u32[1];	// In parent DNSServiceOp increment UID counter
483 		sdr->primary    = *ref;					// Set our primary pointer
484 		sdr->sockfd     = (*ref)->sockfd;		// Inherit primary's socket
485 		sdr->validator  = (*ref)->validator;
486 		sdr->uid        = (*ref)->uid;
487 		//printf("ConnectToServer sharing socket %d\n", sdr->sockfd);
488 		}
489 	else
490 		{
491 		#ifdef SO_NOSIGPIPE
492 		const unsigned long optval = 1;
493 		#endif
494 		*ref = NULL;
495 		sdr->sockfd    = socket(AF_DNSSD, SOCK_STREAM, 0);
496 		sdr->validator = sdr->sockfd ^ ValidatorBits;
497 		if (!dnssd_SocketValid(sdr->sockfd))
498 			{
499 			syslog(LOG_WARNING, "dnssd_clientstub ConnectToServer: socket failed %d %s", dnssd_errno, dnssd_strerror(dnssd_errno));
500 			FreeDNSServiceOp(sdr);
501 			return kDNSServiceErr_NoMemory;
502 			}
503 		#ifdef SO_NOSIGPIPE
504 		// Some environments (e.g. OS X) support turning off SIGPIPE for a socket
505 		if (setsockopt(sdr->sockfd, SOL_SOCKET, SO_NOSIGPIPE, &optval, sizeof(optval)) < 0)
506 			syslog(LOG_WARNING, "dnssd_clientstub ConnectToServer: SO_NOSIGPIPE failed %d %s", dnssd_errno, dnssd_strerror(dnssd_errno));
507 		#endif
508 		#if defined(USE_TCP_LOOPBACK)
509 		saddr.sin_family      = AF_INET;
510 		saddr.sin_addr.s_addr = inet_addr(MDNS_TCP_SERVERADDR);
511 		saddr.sin_port        = htons(MDNS_TCP_SERVERPORT);
512 		#else
513 		saddr.sun_family      = AF_LOCAL;
514 		strcpy(saddr.sun_path, MDNS_UDS_SERVERPATH);
515 		#if !defined(__ppc__) && defined(SO_DEFUNCTOK)
516 		{
517 		int defunct = 1;
518 		if (setsockopt(sdr->sockfd, SOL_SOCKET, SO_DEFUNCTOK, &defunct, sizeof(defunct)) < 0)
519 			syslog(LOG_WARNING, "dnssd_clientstub ConnectToServer: SO_DEFUNCTOK failed %d %s", dnssd_errno, dnssd_strerror(dnssd_errno));
520 		}
521 		#endif
522 		#endif
523 
524 		while (1)
525 			{
526 			int err = connect(sdr->sockfd, (struct sockaddr *) &saddr, sizeof(saddr));
527 			if (!err) break; // If we succeeded, return sdr
528 			// If we failed, then it may be because the daemon is still launching.
529 			// This can happen for processes that launch early in the boot process, while the
530 			// daemon is still coming up. Rather than fail here, we'll wait a bit and try again.
531 			// If, after four seconds, we still can't connect to the daemon,
532 			// then we give up and return a failure code.
533 			if (++NumTries < DNSSD_CLIENT_MAXTRIES) sleep(1); // Sleep a bit, then try again
534 			else { dnssd_close(sdr->sockfd); FreeDNSServiceOp(sdr); return kDNSServiceErr_ServiceNotRunning; }
535 			}
536 		//printf("ConnectToServer opened socket %d\n", sdr->sockfd);
537 		}
538 
539 	*ref = sdr;
540 	return kDNSServiceErr_NoError;
541 	}
542 
543 #define deliver_request_bailout(MSG) \
544 	do { syslog(LOG_WARNING, "dnssd_clientstub deliver_request: %s failed %d (%s)", (MSG), dnssd_errno, dnssd_strerror(dnssd_errno)); goto cleanup; } while(0)
545 
deliver_request(ipc_msg_hdr * hdr,DNSServiceOp * sdr)546 static DNSServiceErrorType deliver_request(ipc_msg_hdr *hdr, DNSServiceOp *sdr)
547 	{
548 	uint32_t datalen = hdr->datalen;	// We take a copy here because we're going to convert hdr->datalen to network byte order
549 	#if defined(USE_TCP_LOOPBACK) || defined(USE_NAMED_ERROR_RETURN_SOCKET)
550 	char *const data = (char *)hdr + sizeof(ipc_msg_hdr);
551 	#endif
552 	dnssd_sock_t listenfd = dnssd_InvalidSocket, errsd = dnssd_InvalidSocket;
553 	DNSServiceErrorType err = kDNSServiceErr_Unknown;	// Default for the "goto cleanup" cases
554 	int MakeSeparateReturnSocket = 0;
555 
556 	// Note: need to check hdr->op, not sdr->op.
557 	// hdr->op contains the code for the specific operation we're currently doing, whereas sdr->op
558 	// contains the original parent DNSServiceOp (e.g. for an add_record_request, hdr->op will be
559 	// add_record_request but the parent sdr->op will be connection_request or reg_service_request)
560 	if (sdr->primary ||
561 		hdr->op == reg_record_request || hdr->op == add_record_request || hdr->op == update_record_request || hdr->op == remove_record_request)
562 		MakeSeparateReturnSocket = 1;
563 
564 	if (!DNSServiceRefValid(sdr))
565 		{
566 		syslog(LOG_WARNING, "dnssd_clientstub deliver_request: invalid DNSServiceRef %p %08X %08X", sdr, sdr->sockfd, sdr->validator);
567 		return kDNSServiceErr_BadReference;
568 		}
569 
570 	if (!hdr) { syslog(LOG_WARNING, "dnssd_clientstub deliver_request: !hdr"); return kDNSServiceErr_Unknown; }
571 
572 	if (MakeSeparateReturnSocket)
573 		{
574 		#if defined(USE_TCP_LOOPBACK)
575 			{
576 			union { uint16_t s; u_char b[2]; } port;
577 			dnssd_sockaddr_t caddr;
578 			dnssd_socklen_t len = (dnssd_socklen_t) sizeof(caddr);
579 			listenfd = socket(AF_DNSSD, SOCK_STREAM, 0);
580 			if (!dnssd_SocketValid(listenfd)) deliver_request_bailout("TCP socket");
581 
582 			caddr.sin_family      = AF_INET;
583 			caddr.sin_port        = 0;
584 			caddr.sin_addr.s_addr = inet_addr(MDNS_TCP_SERVERADDR);
585 			if (bind(listenfd, (struct sockaddr*) &caddr, sizeof(caddr)) < 0) deliver_request_bailout("TCP bind");
586 			if (getsockname(listenfd, (struct sockaddr*) &caddr, &len)   < 0) deliver_request_bailout("TCP getsockname");
587 			if (listen(listenfd, 1)                                      < 0) deliver_request_bailout("TCP listen");
588 			port.s = caddr.sin_port;
589 			data[0] = port.b[0];  // don't switch the byte order, as the
590 			data[1] = port.b[1];  // daemon expects it in network byte order
591 			}
592 		#elif defined(USE_NAMED_ERROR_RETURN_SOCKET)
593 			{
594 			mode_t mask;
595 			int bindresult;
596 			dnssd_sockaddr_t caddr;
597 			listenfd = socket(AF_DNSSD, SOCK_STREAM, 0);
598 			if (!dnssd_SocketValid(listenfd)) deliver_request_bailout("USE_NAMED_ERROR_RETURN_SOCKET socket");
599 
600 			caddr.sun_family = AF_LOCAL;
601 			// According to Stevens (section 3.2), there is no portable way to
602 			// determine whether sa_len is defined on a particular platform.
603 			#ifndef NOT_HAVE_SA_LEN
604 			caddr.sun_len = sizeof(struct sockaddr_un);
605 			#endif
606 			strcpy(caddr.sun_path, data);
607 			mask = umask(0);
608 			bindresult = bind(listenfd, (struct sockaddr *)&caddr, sizeof(caddr));
609 			umask(mask);
610 			if (bindresult          < 0) deliver_request_bailout("USE_NAMED_ERROR_RETURN_SOCKET bind");
611 			if (listen(listenfd, 1) < 0) deliver_request_bailout("USE_NAMED_ERROR_RETURN_SOCKET listen");
612 			}
613 		#else
614 			{
615 			dnssd_sock_t sp[2];
616 			if (socketpair(AF_DNSSD, SOCK_STREAM, 0, sp) < 0) deliver_request_bailout("socketpair");
617 			else
618 				{
619 				errsd    = sp[0];	// We'll read our four-byte error code from sp[0]
620 				listenfd = sp[1];	// We'll send sp[1] to the daemon
621 				#if !defined(__ppc__) && defined(SO_DEFUNCTOK)
622 				{
623 				int defunct = 1;
624 				if (setsockopt(errsd, SOL_SOCKET, SO_DEFUNCTOK, &defunct, sizeof(defunct)) < 0)
625 					syslog(LOG_WARNING, "dnssd_clientstub ConnectToServer: SO_DEFUNCTOK failed %d %s", dnssd_errno, dnssd_strerror(dnssd_errno));
626 				}
627 				#endif
628 				}
629 			}
630 		#endif
631 		}
632 
633 #if !defined(USE_TCP_LOOPBACK) && !defined(USE_NAMED_ERROR_RETURN_SOCKET)
634 	// If we're going to make a separate error return socket, and pass it to the daemon
635 	// using sendmsg, then we'll hold back one data byte to go with it.
636 	// On some versions of Unix (including Leopard) sending a control message without
637 	// any associated data does not work reliably -- e.g. one particular issue we ran
638 	// into is that if the receiving program is in a kqueue loop waiting to be notified
639 	// of the received message, it doesn't get woken up when the control message arrives.
640 	if (MakeSeparateReturnSocket || sdr->op == send_bpf) datalen--;		// Okay to use sdr->op when checking for op == send_bpf
641 #endif
642 
643 	// At this point, our listening socket is set up and waiting, if necessary, for the daemon to connect back to
644 	ConvertHeaderBytes(hdr);
645 	//syslog(LOG_WARNING, "dnssd_clientstub deliver_request writing %lu bytes", (unsigned long)(datalen + sizeof(ipc_msg_hdr)));
646 	//if (MakeSeparateReturnSocket) syslog(LOG_WARNING, "dnssd_clientstub deliver_request name is %s", data);
647 #if TEST_SENDING_ONE_BYTE_AT_A_TIME
648 	unsigned int i;
649 	for (i=0; i<datalen + sizeof(ipc_msg_hdr); i++)
650 		{
651 		syslog(LOG_WARNING, "dnssd_clientstub deliver_request writing %d", i);
652 		if (write_all(sdr->sockfd, ((char *)hdr)+i, 1) < 0)
653 			{ syslog(LOG_WARNING, "write_all (byte %u) failed", i); goto cleanup; }
654 		usleep(10000);
655 		}
656 #else
657 	if (write_all(sdr->sockfd, (char *)hdr, datalen + sizeof(ipc_msg_hdr)) < 0)
658 		{
659 		// write_all already prints an error message if there is an error writing to
660 		// the socket except for DEFUNCT. Logging here is unnecessary and also wrong
661 		// in the case of DEFUNCT sockets
662 		syslog(LOG_INFO, "dnssd_clientstub deliver_request ERROR: write_all(%d, %lu bytes) failed",
663 			sdr->sockfd, (unsigned long)(datalen + sizeof(ipc_msg_hdr)));
664 		goto cleanup;
665 		}
666 #endif
667 
668 	if (!MakeSeparateReturnSocket) errsd = sdr->sockfd;
669 	if (MakeSeparateReturnSocket || sdr->op == send_bpf)	// Okay to use sdr->op when checking for op == send_bpf
670 		{
671 #if defined(USE_TCP_LOOPBACK) || defined(USE_NAMED_ERROR_RETURN_SOCKET)
672 		// At this point we may block in accept for a few milliseconds waiting for the daemon to connect back to us,
673 		// but that's okay -- the daemon is a trusted service and we know if won't take more than a few milliseconds to respond.
674 		dnssd_sockaddr_t daddr;
675 		dnssd_socklen_t len = sizeof(daddr);
676 		if ((err = wait_for_daemon(listenfd, DNSSD_CLIENT_TIMEOUT)) != kDNSServiceErr_NoError) goto cleanup;
677 		errsd = accept(listenfd, (struct sockaddr *)&daddr, &len);
678 		if (!dnssd_SocketValid(errsd)) deliver_request_bailout("accept");
679 #else
680 
681 #if APPLE_OSX_mDNSResponder
682 // On Leopard, the stock definitions of the CMSG_* macros in /usr/include/sys/socket.h,
683 // while arguably correct in theory, nonetheless in practice produce code that doesn't work on 64-bit machines
684 // For details see <rdar://problem/5565787> Bonjour API broken for 64-bit apps (SCM_RIGHTS sendmsg fails)
685 #undef  CMSG_DATA
686 #define CMSG_DATA(cmsg) ((unsigned char *)(cmsg) + (sizeof(struct cmsghdr)))
687 #undef  CMSG_SPACE
688 #define CMSG_SPACE(l)   ((sizeof(struct cmsghdr)) + (l))
689 #undef  CMSG_LEN
690 #define CMSG_LEN(l)     ((sizeof(struct cmsghdr)) + (l))
691 #endif
692 
693 		struct iovec vec = { ((char *)hdr) + sizeof(ipc_msg_hdr) + datalen, 1 }; // Send the last byte along with the SCM_RIGHTS
694 		struct msghdr msg;
695 		struct cmsghdr *cmsg;
696 		char cbuf[CMSG_SPACE(sizeof(dnssd_sock_t))];
697 
698 		if (sdr->op == send_bpf)	// Okay to use sdr->op when checking for op == send_bpf
699 			{
700 			int i;
701 			char p[12];		// Room for "/dev/bpf999" with terminating null
702 			for (i=0; i<100; i++)
703 				{
704 				snprintf(p, sizeof(p), "/dev/bpf%d", i);
705 				listenfd = open(p, O_RDWR, 0);
706 				//if (dnssd_SocketValid(listenfd)) syslog(LOG_WARNING, "Sending fd %d for %s", listenfd, p);
707 				if (!dnssd_SocketValid(listenfd) && dnssd_errno != EBUSY)
708 					syslog(LOG_WARNING, "Error opening %s %d (%s)", p, dnssd_errno, dnssd_strerror(dnssd_errno));
709 				if (dnssd_SocketValid(listenfd) || dnssd_errno != EBUSY) break;
710 				}
711 			}
712 
713 		msg.msg_name       = 0;
714 		msg.msg_namelen    = 0;
715 		msg.msg_iov        = &vec;
716 		msg.msg_iovlen     = 1;
717 		msg.msg_control    = cbuf;
718 		msg.msg_controllen = CMSG_LEN(sizeof(dnssd_sock_t));
719 		msg.msg_flags      = 0;
720 		cmsg = CMSG_FIRSTHDR(&msg);
721 		cmsg->cmsg_len     = CMSG_LEN(sizeof(dnssd_sock_t));
722 		cmsg->cmsg_level   = SOL_SOCKET;
723 		cmsg->cmsg_type    = SCM_RIGHTS;
724 		*((dnssd_sock_t *)CMSG_DATA(cmsg)) = listenfd;
725 
726 #if TEST_KQUEUE_CONTROL_MESSAGE_BUG
727 		sleep(1);
728 #endif
729 
730 #if DEBUG_64BIT_SCM_RIGHTS
731 		syslog(LOG_WARNING, "dnssd_clientstub sendmsg read sd=%d write sd=%d %ld %ld %ld/%ld/%ld/%ld",
732 			errsd, listenfd, sizeof(dnssd_sock_t), sizeof(void*),
733 			sizeof(struct cmsghdr) + sizeof(dnssd_sock_t),
734 			CMSG_LEN(sizeof(dnssd_sock_t)), (long)CMSG_SPACE(sizeof(dnssd_sock_t)),
735 			(long)((char*)CMSG_DATA(cmsg) + 4 - cbuf));
736 #endif // DEBUG_64BIT_SCM_RIGHTS
737 
738 		if (sendmsg(sdr->sockfd, &msg, 0) < 0)
739 			{
740 			syslog(LOG_WARNING, "dnssd_clientstub deliver_request ERROR: sendmsg failed read sd=%d write sd=%d errno %d (%s)",
741 				errsd, listenfd, dnssd_errno, dnssd_strerror(dnssd_errno));
742 			err = kDNSServiceErr_Incompatible;
743 			goto cleanup;
744 			}
745 
746 #if DEBUG_64BIT_SCM_RIGHTS
747 		syslog(LOG_WARNING, "dnssd_clientstub sendmsg read sd=%d write sd=%d okay", errsd, listenfd);
748 #endif // DEBUG_64BIT_SCM_RIGHTS
749 
750 #endif
751 		// Close our end of the socketpair *before* blocking in read_all to get the four-byte error code.
752 		// Otherwise, if the daemon closes our socket (or crashes), we block in read_all() forever
753 		// because the socket is not closed (we still have an open reference to it ourselves).
754 		dnssd_close(listenfd);
755 		listenfd = dnssd_InvalidSocket;		// Make sure we don't close it a second time in the cleanup handling below
756 		}
757 
758 	// At this point we may block in read_all for a few milliseconds waiting for the daemon to send us the error code,
759 	// but that's okay -- the daemon is a trusted service and we know if won't take more than a few milliseconds to respond.
760 	if (sdr->op == send_bpf)	// Okay to use sdr->op when checking for op == send_bpf
761 		err = kDNSServiceErr_NoError;
762 	else if ((err = wait_for_daemon(errsd, DNSSD_CLIENT_TIMEOUT)) == kDNSServiceErr_NoError)
763 		{
764 		if (read_all(errsd, (char*)&err, (int)sizeof(err)) < 0)
765 			err = kDNSServiceErr_ServiceNotRunning; // On failure read_all will have written a message to syslog for us
766 		else
767 			err = ntohl(err);
768 		}
769 
770 	//syslog(LOG_WARNING, "dnssd_clientstub deliver_request: retrieved error code %d", err);
771 
772 cleanup:
773 	if (MakeSeparateReturnSocket)
774 		{
775 		if (dnssd_SocketValid(listenfd)) dnssd_close(listenfd);
776 		if (dnssd_SocketValid(errsd))    dnssd_close(errsd);
777 #if defined(USE_NAMED_ERROR_RETURN_SOCKET)
778 		// syslog(LOG_WARNING, "dnssd_clientstub deliver_request: removing UDS: %s", data);
779 		if (unlink(data) != 0)
780 			syslog(LOG_WARNING, "dnssd_clientstub WARNING: unlink(\"%s\") failed errno %d (%s)", data, dnssd_errno, dnssd_strerror(dnssd_errno));
781 		// else syslog(LOG_WARNING, "dnssd_clientstub deliver_request: removed UDS: %s", data);
782 #endif
783 		}
784 
785 	free(hdr);
786 	return err;
787 	}
788 
DNSServiceRefSockFD(DNSServiceRef sdRef)789 int DNSSD_API DNSServiceRefSockFD(DNSServiceRef sdRef)
790 	{
791 	if (!sdRef) { syslog(LOG_WARNING, "dnssd_clientstub DNSServiceRefSockFD called with NULL DNSServiceRef"); return dnssd_InvalidSocket; }
792 
793 	if (!DNSServiceRefValid(sdRef))
794 		{
795 		syslog(LOG_WARNING, "dnssd_clientstub DNSServiceRefSockFD called with invalid DNSServiceRef %p %08X %08X",
796 			sdRef, sdRef->sockfd, sdRef->validator);
797 		return dnssd_InvalidSocket;
798 		}
799 
800 	if (sdRef->primary)
801 		{
802 		syslog(LOG_WARNING, "dnssd_clientstub DNSServiceRefSockFD undefined for kDNSServiceFlagsShareConnection subordinate DNSServiceRef %p", sdRef);
803 		return dnssd_InvalidSocket;
804 		}
805 
806 	return (int) sdRef->sockfd;
807 	}
808 
809 #if _DNS_SD_LIBDISPATCH
CallbackWithError(DNSServiceRef sdRef,DNSServiceErrorType error)810 static void CallbackWithError(DNSServiceRef sdRef, DNSServiceErrorType error)
811 	{
812 	DNSServiceOp *sdr = sdRef;
813 	DNSServiceOp *sdrNext;
814 	DNSRecord *rec;
815 	DNSRecord *recnext;
816 	int morebytes;
817 
818 	while (sdr)
819 		{
820 		// We can't touch the sdr after the callback as it can be deallocated in the callback
821 		sdrNext = sdr->next;
822 		morebytes = 1;
823 		sdr->moreptr = &morebytes;
824 		switch (sdr->op)
825 			{
826 			case resolve_request:
827 				if (sdr->AppCallback)((DNSServiceResolveReply)    sdr->AppCallback)(sdr, 0, 0, error, NULL, 0, 0, 0, NULL,    sdr->AppContext);
828 				break;
829 			case query_request:
830 				if (sdr->AppCallback)((DNSServiceQueryRecordReply)sdr->AppCallback)(sdr, 0, 0, error, NULL, 0, 0, 0, NULL, 0, sdr->AppContext);
831 				break;
832 			case addrinfo_request:
833 				if (sdr->AppCallback)((DNSServiceGetAddrInfoReply)sdr->AppCallback)(sdr, 0, 0, error, NULL, NULL, 0,          sdr->AppContext);
834 				break;
835 			case browse_request:
836 				if (sdr->AppCallback)((DNSServiceBrowseReply)     sdr->AppCallback)(sdr, 0, 0, error, NULL, 0, NULL,          sdr->AppContext);
837 				break;
838 			case reg_service_request:
839 				if (sdr->AppCallback)((DNSServiceRegisterReply)   sdr->AppCallback)(sdr, 0,    error, NULL, 0, NULL,          sdr->AppContext);
840 				break;
841 			case enumeration_request:
842 				if (sdr->AppCallback)((DNSServiceDomainEnumReply) sdr->AppCallback)(sdr, 0, 0, error, NULL,                   sdr->AppContext);
843 				break;
844 			case sethost_request:
845 				if (sdr->AppCallback)((DNSServiceSetHostReply)    sdr->AppCallback)(sdr, 0,    error, NULL,                   sdr->AppContext);
846 				break;
847 			case connection_request:
848 				// This means Register Record, walk the list of DNSRecords to do the callback
849 				rec = sdr->rec;
850 				while (rec)
851 					{
852 					recnext = rec->recnext;
853 					if (rec->AppCallback) ((DNSServiceRegisterRecordReply)rec->AppCallback)(sdr, 0, 0, error, rec->AppContext);
854 					// The Callback can call DNSServiceRefDeallocate which in turn frees sdr and all the records.
855 					// Detect that and return early
856 					if (!morebytes){syslog(LOG_WARNING, "dnssdclientstub:Record: CallbackwithError morebytes zero"); return;}
857 					rec = recnext;
858 					}
859 				break;
860 			case port_mapping_request:
861 				if (sdr->AppCallback)((DNSServiceNATPortMappingReply)sdr->AppCallback)(sdr, 0, 0, error, 0, 0, 0, 0, 0, sdr->AppContext);
862 				break;
863 			default:
864 				syslog(LOG_WARNING, "dnssd_clientstub CallbackWithError called with bad op %d", sdr->op);
865 			}
866 		// If DNSServiceRefDeallocate was called in the callback, morebytes will be zero. It means
867 		// all other sdrefs have been freed. This happens for shared connections where the
868 		// DNSServiceRefDeallocate on the first sdRef frees all other sdrefs.
869 		if (!morebytes){syslog(LOG_WARNING, "dnssdclientstub:sdRef: CallbackwithError morebytes zero"); return;}
870 		sdr = sdrNext;
871 		}
872 	}
873 #endif // _DNS_SD_LIBDISPATCH
874 
875 // Handle reply from server, calling application client callback. If there is no reply
876 // from the daemon on the socket contained in sdRef, the call will block.
DNSServiceProcessResult(DNSServiceRef sdRef)877 DNSServiceErrorType DNSSD_API DNSServiceProcessResult(DNSServiceRef sdRef)
878 	{
879 	int morebytes = 0;
880 
881 	if (!sdRef) { syslog(LOG_WARNING, "dnssd_clientstub DNSServiceProcessResult called with NULL DNSServiceRef"); return kDNSServiceErr_BadParam; }
882 
883 	if (!DNSServiceRefValid(sdRef))
884 		{
885 		syslog(LOG_WARNING, "dnssd_clientstub DNSServiceProcessResult called with invalid DNSServiceRef %p %08X %08X", sdRef, sdRef->sockfd, sdRef->validator);
886 		return kDNSServiceErr_BadReference;
887 		}
888 
889 	if (sdRef->primary)
890 		{
891 		syslog(LOG_WARNING, "dnssd_clientstub DNSServiceProcessResult undefined for kDNSServiceFlagsShareConnection subordinate DNSServiceRef %p", sdRef);
892 		return kDNSServiceErr_BadReference;
893 		}
894 
895 	if (!sdRef->ProcessReply)
896 		{
897 		static int num_logs = 0;
898 		if (num_logs < 10) syslog(LOG_WARNING, "dnssd_clientstub DNSServiceProcessResult called with DNSServiceRef with no ProcessReply function");
899 		if (num_logs < 1000) num_logs++; else sleep(1);
900 		return kDNSServiceErr_BadReference;
901 		}
902 
903 	do
904 		{
905 		CallbackHeader cbh;
906 		char *data;
907 
908 		// return NoError on EWOULDBLOCK. This will handle the case
909 		// where a non-blocking socket is told there is data, but it was a false positive.
910 		// On error, read_all will write a message to syslog for us, so don't need to duplicate that here
911 		// Note: If we want to properly support using non-blocking sockets in the future
912 		int result = read_all(sdRef->sockfd, (void *)&cbh.ipc_hdr, sizeof(cbh.ipc_hdr));
913 		if (result == read_all_fail)
914 			{
915 			// Set the ProcessReply to NULL before callback as the sdRef can get deallocated
916 			// in the callback.
917 			sdRef->ProcessReply = NULL;
918 #if _DNS_SD_LIBDISPATCH
919 			// Call the callbacks with an error if using the dispatch API, as DNSServiceProcessResult
920 			// is not called by the application and hence need to communicate the error. Cancel the
921 			// source so that we don't get any more events
922 			if (sdRef->disp_source)
923 				{
924 				dispatch_source_cancel(sdRef->disp_source);
925 				dispatch_release(sdRef->disp_source);
926 				sdRef->disp_source = NULL;
927 				CallbackWithError(sdRef, kDNSServiceErr_ServiceNotRunning);
928 				}
929 #endif
930 			// Don't touch sdRef anymore as it might have been deallocated
931 			return kDNSServiceErr_ServiceNotRunning;
932 			}
933 		else if (result == read_all_wouldblock)
934 			{
935 			if (morebytes && sdRef->logcounter < 100)
936 				{
937 				sdRef->logcounter++;
938 				syslog(LOG_WARNING, "dnssd_clientstub DNSServiceProcessResult error: select indicated data was waiting but read_all returned EWOULDBLOCK");
939 				}
940 			return kDNSServiceErr_NoError;
941 			}
942 
943 		ConvertHeaderBytes(&cbh.ipc_hdr);
944 		if (cbh.ipc_hdr.version != VERSION)
945 			{
946 			syslog(LOG_WARNING, "dnssd_clientstub DNSServiceProcessResult daemon version %d does not match client version %d", cbh.ipc_hdr.version, VERSION);
947 			sdRef->ProcessReply = NULL;
948 			return kDNSServiceErr_Incompatible;
949 			}
950 
951 		data = malloc(cbh.ipc_hdr.datalen);
952 		if (!data) return kDNSServiceErr_NoMemory;
953 		if (read_all(sdRef->sockfd, data, cbh.ipc_hdr.datalen) < 0) // On error, read_all will write a message to syslog for us
954 			{
955 			// Set the ProcessReply to NULL before callback as the sdRef can get deallocated
956 			// in the callback.
957 			sdRef->ProcessReply = NULL;
958 #if _DNS_SD_LIBDISPATCH
959 			// Call the callbacks with an error if using the dispatch API, as DNSServiceProcessResult
960 			// is not called by the application and hence need to communicate the error. Cancel the
961 			// source so that we don't get any more events
962 			if (sdRef->disp_source)
963 				{
964 				dispatch_source_cancel(sdRef->disp_source);
965 				dispatch_release(sdRef->disp_source);
966 				sdRef->disp_source = NULL;
967 				CallbackWithError(sdRef, kDNSServiceErr_ServiceNotRunning);
968 				}
969 #endif
970 			// Don't touch sdRef anymore as it might have been deallocated
971 			free(data);
972 			return kDNSServiceErr_ServiceNotRunning;
973 			}
974 		else
975 			{
976 			const char *ptr = data;
977 			cbh.cb_flags     = get_flags     (&ptr, data + cbh.ipc_hdr.datalen);
978 			cbh.cb_interface = get_uint32    (&ptr, data + cbh.ipc_hdr.datalen);
979 			cbh.cb_err       = get_error_code(&ptr, data + cbh.ipc_hdr.datalen);
980 
981 			// CAUTION: We have to handle the case where the client calls DNSServiceRefDeallocate from within the callback function.
982 			// To do this we set moreptr to point to morebytes. If the client does call DNSServiceRefDeallocate(),
983 			// then that routine will clear morebytes for us, and cause us to exit our loop.
984 			morebytes = more_bytes(sdRef->sockfd);
985 			if (morebytes)
986 				{
987 				cbh.cb_flags |= kDNSServiceFlagsMoreComing;
988 				sdRef->moreptr = &morebytes;
989 				}
990 			if (ptr) sdRef->ProcessReply(sdRef, &cbh, ptr, data + cbh.ipc_hdr.datalen);
991 			// Careful code here:
992 			// If morebytes is non-zero, that means we set sdRef->moreptr above, and the operation was not
993 			// cancelled out from under us, so now we need to clear sdRef->moreptr so we don't leave a stray
994 			// dangling pointer pointing to a long-gone stack variable.
995 			// If morebytes is zero, then one of two thing happened:
996 			// (a) morebytes was 0 above, so we didn't set sdRef->moreptr, so we don't need to clear it
997 			// (b) morebytes was 1 above, and we set sdRef->moreptr, but the operation was cancelled (with DNSServiceRefDeallocate()),
998 			//     so we MUST NOT try to dereference our stale sdRef pointer.
999 			if (morebytes) sdRef->moreptr = NULL;
1000 			}
1001 		free(data);
1002 		} while (morebytes);
1003 
1004 	return kDNSServiceErr_NoError;
1005 	}
1006 
DNSServiceRefDeallocate(DNSServiceRef sdRef)1007 void DNSSD_API DNSServiceRefDeallocate(DNSServiceRef sdRef)
1008 	{
1009 	if (!sdRef) { syslog(LOG_WARNING, "dnssd_clientstub DNSServiceRefDeallocate called with NULL DNSServiceRef"); return; }
1010 
1011 	if (!DNSServiceRefValid(sdRef))		// Also verifies dnssd_SocketValid(sdRef->sockfd) for us too
1012 		{
1013 		syslog(LOG_WARNING, "dnssd_clientstub DNSServiceRefDeallocate called with invalid DNSServiceRef %p %08X %08X", sdRef, sdRef->sockfd, sdRef->validator);
1014 		return;
1015 		}
1016 
1017 	// If we're in the middle of a DNSServiceProcessResult() invocation for this DNSServiceRef, clear its morebytes flag to break it out of its while loop
1018 	if (sdRef->moreptr) *(sdRef->moreptr) = 0;
1019 
1020 	if (sdRef->primary)		// If this is a subordinate DNSServiceOp, just send a 'stop' command
1021 		{
1022 		DNSServiceOp **p = &sdRef->primary->next;
1023 		while (*p && *p != sdRef) p = &(*p)->next;
1024 		if (*p)
1025 			{
1026 			char *ptr;
1027 			size_t len = 0;
1028 			ipc_msg_hdr *hdr = create_hdr(cancel_request, &len, &ptr, 0, sdRef);
1029 			if (hdr)
1030 				{
1031 				ConvertHeaderBytes(hdr);
1032 				write_all(sdRef->sockfd, (char *)hdr, len);
1033 				free(hdr);
1034 				}
1035 			*p = sdRef->next;
1036 			FreeDNSServiceOp(sdRef);
1037 			}
1038 		}
1039 	else					// else, make sure to terminate all subordinates as well
1040 		{
1041 #if _DNS_SD_LIBDISPATCH
1042 		// The cancel handler will close the fd if a dispatch source has been set
1043 		if (sdRef->disp_source)
1044 			{
1045 			// By setting the ProcessReply to NULL, we make sure that we never call
1046 			// the application callbacks ever, after returning from this function. We
1047 			// assume that DNSServiceRefDeallocate is called from the serial queue
1048 			// that was passed to DNSServiceSetDispatchQueue. Hence, dispatch_source_cancel
1049 			// should cancel all the blocks on the queue and hence there should be no more
1050 			// callbacks when we return from this function. Setting ProcessReply to NULL
1051 			// provides extra protection.
1052 			sdRef->ProcessReply = NULL;
1053 			dispatch_source_cancel(sdRef->disp_source);
1054 			dispatch_release(sdRef->disp_source);
1055 			sdRef->disp_source = NULL;
1056 			}
1057 			// if disp_queue is set, it means it used the DNSServiceSetDispatchQueue API. In that case,
1058 			// when the source was cancelled, the fd was closed in the handler. Currently the source
1059 			// is cancelled only when the mDNSResponder daemon dies
1060 		else if (!sdRef->disp_queue) dnssd_close(sdRef->sockfd);
1061 #else
1062 		dnssd_close(sdRef->sockfd);
1063 #endif
1064 		// Free DNSRecords added in DNSRegisterRecord if they have not
1065 		// been freed in DNSRemoveRecord
1066 		while (sdRef)
1067 			{
1068 			DNSServiceOp *p = sdRef;
1069 			sdRef = sdRef->next;
1070 			FreeDNSServiceOp(p);
1071 			}
1072 		}
1073 	}
1074 
DNSServiceGetProperty(const char * property,void * result,uint32_t * size)1075 DNSServiceErrorType DNSSD_API DNSServiceGetProperty(const char *property, void *result, uint32_t *size)
1076 	{
1077 	char *ptr;
1078 	size_t len = strlen(property) + 1;
1079 	ipc_msg_hdr *hdr;
1080 	DNSServiceOp *tmp;
1081 	uint32_t actualsize;
1082 
1083 	DNSServiceErrorType err = ConnectToServer(&tmp, 0, getproperty_request, NULL, NULL, NULL);
1084 	if (err) return err;
1085 
1086 	hdr = create_hdr(getproperty_request, &len, &ptr, 0, tmp);
1087 	if (!hdr) { DNSServiceRefDeallocate(tmp); return kDNSServiceErr_NoMemory; }
1088 
1089 	put_string(property, &ptr);
1090 	err = deliver_request(hdr, tmp);		// Will free hdr for us
1091 	if (read_all(tmp->sockfd, (char*)&actualsize, (int)sizeof(actualsize)) < 0)
1092 		{ DNSServiceRefDeallocate(tmp); return kDNSServiceErr_ServiceNotRunning; }
1093 
1094 	actualsize = ntohl(actualsize);
1095 	if (read_all(tmp->sockfd, (char*)result, actualsize < *size ? actualsize : *size) < 0)
1096 		{ DNSServiceRefDeallocate(tmp); return kDNSServiceErr_ServiceNotRunning; }
1097 	DNSServiceRefDeallocate(tmp);
1098 
1099 	// Swap version result back to local process byte order
1100 	if (!strcmp(property, kDNSServiceProperty_DaemonVersion) && *size >= 4)
1101 		*(uint32_t*)result = ntohl(*(uint32_t*)result);
1102 
1103 	*size = actualsize;
1104 	return kDNSServiceErr_NoError;
1105 	}
1106 
handle_resolve_response(DNSServiceOp * const sdr,const CallbackHeader * const cbh,const char * data,const char * end)1107 static void handle_resolve_response(DNSServiceOp *const sdr, const CallbackHeader *const cbh, const char *data, const char *end)
1108 	{
1109 	char fullname[kDNSServiceMaxDomainName];
1110 	char target[kDNSServiceMaxDomainName];
1111 	uint16_t txtlen;
1112 	union { uint16_t s; u_char b[2]; } port;
1113 	unsigned char *txtrecord;
1114 
1115 	get_string(&data, end, fullname, kDNSServiceMaxDomainName);
1116 	get_string(&data, end, target,   kDNSServiceMaxDomainName);
1117 	if (!data || data + 2 > end) goto fail;
1118 
1119 	port.b[0] = *data++;
1120 	port.b[1] = *data++;
1121 	txtlen = get_uint16(&data, end);
1122 	txtrecord = (unsigned char *)get_rdata(&data, end, txtlen);
1123 
1124 	if (!data) goto fail;
1125 	((DNSServiceResolveReply)sdr->AppCallback)(sdr, cbh->cb_flags, cbh->cb_interface, cbh->cb_err, fullname, target, port.s, txtlen, txtrecord, sdr->AppContext);
1126 	return;
1127 	// MUST NOT touch sdr after invoking AppCallback -- client is allowed to dispose it from within callback function
1128 fail:
1129 	syslog(LOG_WARNING, "dnssd_clientstub handle_resolve_response: error reading result from daemon");
1130 	}
1131 
DNSServiceResolve(DNSServiceRef * sdRef,DNSServiceFlags flags,uint32_t interfaceIndex,const char * name,const char * regtype,const char * domain,DNSServiceResolveReply callBack,void * context)1132 DNSServiceErrorType DNSSD_API DNSServiceResolve
1133 	(
1134 	DNSServiceRef                 *sdRef,
1135 	DNSServiceFlags               flags,
1136 	uint32_t                      interfaceIndex,
1137 	const char                    *name,
1138 	const char                    *regtype,
1139 	const char                    *domain,
1140 	DNSServiceResolveReply        callBack,
1141 	void                          *context
1142 	)
1143 	{
1144 	char *ptr;
1145 	size_t len;
1146 	ipc_msg_hdr *hdr;
1147 	DNSServiceErrorType err;
1148 
1149 	if (!name || !regtype || !domain || !callBack) return kDNSServiceErr_BadParam;
1150 
1151 	// Need a real InterfaceID for WakeOnResolve
1152 	if ((flags & kDNSServiceFlagsWakeOnResolve) != 0 &&
1153 		((interfaceIndex == kDNSServiceInterfaceIndexAny) ||
1154 		(interfaceIndex == kDNSServiceInterfaceIndexLocalOnly) ||
1155 		(interfaceIndex == kDNSServiceInterfaceIndexUnicast) ||
1156 		(interfaceIndex == kDNSServiceInterfaceIndexP2P)))
1157 		{
1158 		return kDNSServiceErr_BadParam;
1159 		}
1160 
1161 	err = ConnectToServer(sdRef, flags, resolve_request, handle_resolve_response, callBack, context);
1162 	if (err) return err;	// On error ConnectToServer leaves *sdRef set to NULL
1163 
1164 	// Calculate total message length
1165 	len = sizeof(flags);
1166 	len += sizeof(interfaceIndex);
1167 	len += strlen(name) + 1;
1168 	len += strlen(regtype) + 1;
1169 	len += strlen(domain) + 1;
1170 
1171 	hdr = create_hdr(resolve_request, &len, &ptr, (*sdRef)->primary ? 1 : 0, *sdRef);
1172 	if (!hdr) { DNSServiceRefDeallocate(*sdRef); *sdRef = NULL; return kDNSServiceErr_NoMemory; }
1173 
1174 	put_flags(flags, &ptr);
1175 	put_uint32(interfaceIndex, &ptr);
1176 	put_string(name, &ptr);
1177 	put_string(regtype, &ptr);
1178 	put_string(domain, &ptr);
1179 
1180 	err = deliver_request(hdr, *sdRef);		// Will free hdr for us
1181 	if (err) { DNSServiceRefDeallocate(*sdRef); *sdRef = NULL; }
1182 	return err;
1183 	}
1184 
handle_query_response(DNSServiceOp * const sdr,const CallbackHeader * const cbh,const char * data,const char * const end)1185 static void handle_query_response(DNSServiceOp *const sdr, const CallbackHeader *const cbh, const char *data, const char *const end)
1186 	{
1187 	uint32_t ttl;
1188 	char name[kDNSServiceMaxDomainName];
1189 	uint16_t rrtype, rrclass, rdlen;
1190 	const char *rdata;
1191 
1192 	get_string(&data, end, name, kDNSServiceMaxDomainName);
1193 	rrtype  = get_uint16(&data, end);
1194 	rrclass = get_uint16(&data, end);
1195 	rdlen   = get_uint16(&data, end);
1196 	rdata   = get_rdata(&data, end, rdlen);
1197 	ttl     = get_uint32(&data, end);
1198 
1199 	if (!data) syslog(LOG_WARNING, "dnssd_clientstub handle_query_response: error reading result from daemon");
1200 	else ((DNSServiceQueryRecordReply)sdr->AppCallback)(sdr, cbh->cb_flags, cbh->cb_interface, cbh->cb_err, name, rrtype, rrclass, rdlen, rdata, ttl, sdr->AppContext);
1201 	// MUST NOT touch sdr after invoking AppCallback -- client is allowed to dispose it from within callback function
1202 	}
1203 
DNSServiceQueryRecord(DNSServiceRef * sdRef,DNSServiceFlags flags,uint32_t interfaceIndex,const char * name,uint16_t rrtype,uint16_t rrclass,DNSServiceQueryRecordReply callBack,void * context)1204 DNSServiceErrorType DNSSD_API DNSServiceQueryRecord
1205 	(
1206 	DNSServiceRef              *sdRef,
1207 	DNSServiceFlags             flags,
1208 	uint32_t                    interfaceIndex,
1209 	const char                 *name,
1210 	uint16_t                    rrtype,
1211 	uint16_t                    rrclass,
1212 	DNSServiceQueryRecordReply  callBack,
1213 	void                       *context
1214 	)
1215 	{
1216 	char *ptr;
1217 	size_t len;
1218 	ipc_msg_hdr *hdr;
1219 	DNSServiceErrorType err = ConnectToServer(sdRef, flags, query_request, handle_query_response, callBack, context);
1220 	if (err) return err;	// On error ConnectToServer leaves *sdRef set to NULL
1221 
1222 	if (!name) name = "\0";
1223 
1224 	// Calculate total message length
1225 	len = sizeof(flags);
1226 	len += sizeof(uint32_t);  // interfaceIndex
1227 	len += strlen(name) + 1;
1228 	len += 2 * sizeof(uint16_t);  // rrtype, rrclass
1229 
1230 	hdr = create_hdr(query_request, &len, &ptr, (*sdRef)->primary ? 1 : 0, *sdRef);
1231 	if (!hdr) { DNSServiceRefDeallocate(*sdRef); *sdRef = NULL; return kDNSServiceErr_NoMemory; }
1232 
1233 	put_flags(flags, &ptr);
1234 	put_uint32(interfaceIndex, &ptr);
1235 	put_string(name, &ptr);
1236 	put_uint16(rrtype, &ptr);
1237 	put_uint16(rrclass, &ptr);
1238 
1239 	err = deliver_request(hdr, *sdRef);		// Will free hdr for us
1240 	if (err) { DNSServiceRefDeallocate(*sdRef); *sdRef = NULL; }
1241 	return err;
1242 	}
1243 
handle_addrinfo_response(DNSServiceOp * const sdr,const CallbackHeader * const cbh,const char * data,const char * const end)1244 static void handle_addrinfo_response(DNSServiceOp *const sdr, const CallbackHeader *const cbh, const char *data, const char *const end)
1245 	{
1246 	char hostname[kDNSServiceMaxDomainName];
1247 	uint16_t rrtype, rrclass, rdlen;
1248 	const char *rdata;
1249 	uint32_t ttl;
1250 
1251 	get_string(&data, end, hostname, kDNSServiceMaxDomainName);
1252 	rrtype  = get_uint16(&data, end);
1253 	rrclass = get_uint16(&data, end);
1254 	rdlen   = get_uint16(&data, end);
1255 	rdata   = get_rdata (&data, end, rdlen);
1256 	ttl     = get_uint32(&data, end);
1257 
1258 	// We only generate client callbacks for A and AAAA results (including NXDOMAIN results for
1259 	// those types, if the client has requested those with the kDNSServiceFlagsReturnIntermediates).
1260 	// Other result types, specifically CNAME referrals, are not communicated to the client, because
1261 	// the DNSServiceGetAddrInfoReply interface doesn't have any meaningful way to communiate CNAME referrals.
1262 	if (!data) syslog(LOG_WARNING, "dnssd_clientstub handle_addrinfo_response: error reading result from daemon");
1263 	else if (rrtype == kDNSServiceType_A || rrtype == kDNSServiceType_AAAA)
1264 		{
1265 		struct sockaddr_in  sa4;
1266 		struct sockaddr_in6 sa6;
1267 		const struct sockaddr *const sa = (rrtype == kDNSServiceType_A) ? (struct sockaddr*)&sa4 : (struct sockaddr*)&sa6;
1268 		if (rrtype == kDNSServiceType_A)
1269 			{
1270 			memset(&sa4, 0, sizeof(sa4));
1271 			#ifndef NOT_HAVE_SA_LEN
1272 			sa4.sin_len = sizeof(struct sockaddr_in);
1273 			#endif
1274 			sa4.sin_family = AF_INET;
1275 			//  sin_port   = 0;
1276 			if (!cbh->cb_err) memcpy(&sa4.sin_addr, rdata, rdlen);
1277 			}
1278 		else
1279 			{
1280 			memset(&sa6, 0, sizeof(sa6));
1281 			#ifndef NOT_HAVE_SA_LEN
1282 			sa6.sin6_len = sizeof(struct sockaddr_in6);
1283 			#endif
1284 			sa6.sin6_family     = AF_INET6;
1285 			//  sin6_port     = 0;
1286 			//  sin6_flowinfo = 0;
1287 			//  sin6_scope_id = 0;
1288 			if (!cbh->cb_err)
1289 				{
1290 				memcpy(&sa6.sin6_addr, rdata, rdlen);
1291 				if (IN6_IS_ADDR_LINKLOCAL(&sa6.sin6_addr)) sa6.sin6_scope_id = cbh->cb_interface;
1292 				}
1293 			}
1294 		((DNSServiceGetAddrInfoReply)sdr->AppCallback)(sdr, cbh->cb_flags, cbh->cb_interface, cbh->cb_err, hostname, sa, ttl, sdr->AppContext);
1295 		// MUST NOT touch sdr after invoking AppCallback -- client is allowed to dispose it from within callback function
1296 		}
1297 	}
1298 
DNSServiceGetAddrInfo(DNSServiceRef * sdRef,DNSServiceFlags flags,uint32_t interfaceIndex,uint32_t protocol,const char * hostname,DNSServiceGetAddrInfoReply callBack,void * context)1299 DNSServiceErrorType DNSSD_API DNSServiceGetAddrInfo
1300 	(
1301 	DNSServiceRef                    *sdRef,
1302 	DNSServiceFlags                  flags,
1303 	uint32_t                         interfaceIndex,
1304 	uint32_t                         protocol,
1305 	const char                       *hostname,
1306 	DNSServiceGetAddrInfoReply       callBack,
1307 	void                             *context          /* may be NULL */
1308 	)
1309 	{
1310 	char *ptr;
1311 	size_t len;
1312 	ipc_msg_hdr *hdr;
1313 	DNSServiceErrorType err;
1314 
1315 	if (!hostname) return kDNSServiceErr_BadParam;
1316 
1317 	err = ConnectToServer(sdRef, flags, addrinfo_request, handle_addrinfo_response, callBack, context);
1318 	if (err) return err;	// On error ConnectToServer leaves *sdRef set to NULL
1319 
1320 	// Calculate total message length
1321 	len = sizeof(flags);
1322 	len += sizeof(uint32_t);      // interfaceIndex
1323 	len += sizeof(uint32_t);      // protocol
1324 	len += strlen(hostname) + 1;
1325 
1326 	hdr = create_hdr(addrinfo_request, &len, &ptr, (*sdRef)->primary ? 1 : 0, *sdRef);
1327 	if (!hdr) { DNSServiceRefDeallocate(*sdRef); *sdRef = NULL; return kDNSServiceErr_NoMemory; }
1328 
1329 	put_flags(flags, &ptr);
1330 	put_uint32(interfaceIndex, &ptr);
1331 	put_uint32(protocol, &ptr);
1332 	put_string(hostname, &ptr);
1333 
1334 	err = deliver_request(hdr, *sdRef);		// Will free hdr for us
1335 	if (err) { DNSServiceRefDeallocate(*sdRef); *sdRef = NULL; }
1336 	return err;
1337 	}
1338 
handle_browse_response(DNSServiceOp * const sdr,const CallbackHeader * const cbh,const char * data,const char * const end)1339 static void handle_browse_response(DNSServiceOp *const sdr, const CallbackHeader *const cbh, const char *data, const char *const end)
1340 	{
1341 	char replyName[256], replyType[kDNSServiceMaxDomainName], replyDomain[kDNSServiceMaxDomainName];
1342 	get_string(&data, end, replyName, 256);
1343 	get_string(&data, end, replyType, kDNSServiceMaxDomainName);
1344 	get_string(&data, end, replyDomain, kDNSServiceMaxDomainName);
1345 	if (!data) syslog(LOG_WARNING, "dnssd_clientstub handle_browse_response: error reading result from daemon");
1346 	else ((DNSServiceBrowseReply)sdr->AppCallback)(sdr, cbh->cb_flags, cbh->cb_interface, cbh->cb_err, replyName, replyType, replyDomain, sdr->AppContext);
1347 	// MUST NOT touch sdr after invoking AppCallback -- client is allowed to dispose it from within callback function
1348 	}
1349 
DNSServiceBrowse(DNSServiceRef * sdRef,DNSServiceFlags flags,uint32_t interfaceIndex,const char * regtype,const char * domain,DNSServiceBrowseReply callBack,void * context)1350 DNSServiceErrorType DNSSD_API DNSServiceBrowse
1351 	(
1352 	DNSServiceRef         *sdRef,
1353 	DNSServiceFlags        flags,
1354 	uint32_t               interfaceIndex,
1355 	const char            *regtype,
1356 	const char            *domain,
1357 	DNSServiceBrowseReply  callBack,
1358 	void                  *context
1359 	)
1360 	{
1361 	char *ptr;
1362 	size_t len;
1363 	ipc_msg_hdr *hdr;
1364 	DNSServiceErrorType err = ConnectToServer(sdRef, flags, browse_request, handle_browse_response, callBack, context);
1365 	if (err) return err;	// On error ConnectToServer leaves *sdRef set to NULL
1366 
1367 	if (!domain) domain = "";
1368 	len = sizeof(flags);
1369 	len += sizeof(interfaceIndex);
1370 	len += strlen(regtype) + 1;
1371 	len += strlen(domain) + 1;
1372 
1373 	hdr = create_hdr(browse_request, &len, &ptr, (*sdRef)->primary ? 1 : 0, *sdRef);
1374 	if (!hdr) { DNSServiceRefDeallocate(*sdRef); *sdRef = NULL; return kDNSServiceErr_NoMemory; }
1375 
1376 	put_flags(flags, &ptr);
1377 	put_uint32(interfaceIndex, &ptr);
1378 	put_string(regtype, &ptr);
1379 	put_string(domain, &ptr);
1380 
1381 	err = deliver_request(hdr, *sdRef);		// Will free hdr for us
1382 	if (err) { DNSServiceRefDeallocate(*sdRef); *sdRef = NULL; }
1383 	return err;
1384 	}
1385 
handle_hostname_changed_response(DNSServiceOp * const sdr,const CallbackHeader * const cbh,const char * data,const char * const end)1386 static void handle_hostname_changed_response(DNSServiceOp *const sdr, const CallbackHeader *const cbh, const char *data, const char *const end)
1387 	{
1388 	char replyHostname[256];
1389 
1390 	get_string(&data, end, replyHostname, sizeof(replyHostname));
1391 	if (!data) syslog(LOG_WARNING, "dnssd_clientstub handle_hostname_changed_response: error reading result from daemon");
1392 	else ((DNSHostnameChangedReply)sdr->AppCallback)(sdr, cbh->cb_flags, cbh->cb_err, replyHostname, sdr->AppContext);
1393 	// MUST NOT touch sdr after invoking AppCallback -- client is allowed to dispose it from within callback function
1394 	}
1395 
DNSSetHostname(DNSServiceRef * sdRef,DNSServiceFlags flags,const char * hostname,DNSHostnameChangedReply callBack,void * context)1396 DNSServiceErrorType DNSSD_API DNSSetHostname
1397 	(
1398 	DNSServiceRef           *sdRef,
1399 	DNSServiceFlags          flags,
1400 	const char              *hostname,
1401 	DNSHostnameChangedReply  callBack,
1402 	void                    *context
1403 	)
1404 	{
1405 	char *ptr;
1406 	size_t len;
1407 	ipc_msg_hdr *hdr;
1408 	DNSServiceErrorType err = ConnectToServer(sdRef, flags, sethost_request, handle_hostname_changed_response, callBack, context);
1409 	if (err) return err;
1410 	len = sizeof(flags);
1411 	len += strlen(hostname) + 1;
1412 
1413 	hdr = create_hdr(sethost_request, &len, &ptr, (*sdRef)->primary ? 1 : 0, *sdRef);
1414 	if (!hdr) { DNSServiceRefDeallocate(*sdRef); *sdRef = NULL; return kDNSServiceErr_NoMemory; }
1415 
1416 	put_flags(flags, &ptr);
1417 	put_string(hostname, &ptr);
1418 	err = deliver_request(hdr, *sdRef);		// Will free hdr for us
1419 	if (err) { DNSServiceRefDeallocate(*sdRef); *sdRef = NULL; }
1420 	return err;
1421 	}
1422 
1423 DNSServiceErrorType DNSSD_API DNSServiceSetDefaultDomainForUser(DNSServiceFlags flags, const char *domain);
DNSServiceSetDefaultDomainForUser(DNSServiceFlags flags,const char * domain)1424 DNSServiceErrorType DNSSD_API DNSServiceSetDefaultDomainForUser(DNSServiceFlags flags, const char *domain)
1425 	{
1426 	DNSServiceOp *tmp;
1427 	char *ptr;
1428 	size_t len = sizeof(flags) + strlen(domain) + 1;
1429 	ipc_msg_hdr *hdr;
1430 	DNSServiceErrorType err = ConnectToServer(&tmp, 0, setdomain_request, NULL, NULL, NULL);
1431 	if (err) return err;
1432 
1433 	hdr = create_hdr(setdomain_request, &len, &ptr, 0, tmp);
1434 	if (!hdr) { DNSServiceRefDeallocate(tmp); return kDNSServiceErr_NoMemory; }
1435 
1436 	put_flags(flags, &ptr);
1437 	put_string(domain, &ptr);
1438 	err = deliver_request(hdr, tmp);		// Will free hdr for us
1439 	DNSServiceRefDeallocate(tmp);
1440 	return err;
1441 	}
1442 
handle_regservice_response(DNSServiceOp * const sdr,const CallbackHeader * const cbh,const char * data,const char * const end)1443 static void handle_regservice_response(DNSServiceOp *const sdr, const CallbackHeader *const cbh, const char *data, const char *const end)
1444 	{
1445 	char name[256], regtype[kDNSServiceMaxDomainName], domain[kDNSServiceMaxDomainName];
1446 	get_string(&data, end, name, 256);
1447 	get_string(&data, end, regtype, kDNSServiceMaxDomainName);
1448 	get_string(&data, end, domain,  kDNSServiceMaxDomainName);
1449 	if (!data) syslog(LOG_WARNING, "dnssd_clientstub handle_regservice_response: error reading result from daemon");
1450 	else ((DNSServiceRegisterReply)sdr->AppCallback)(sdr, cbh->cb_flags, cbh->cb_err, name, regtype, domain, sdr->AppContext);
1451 	// MUST NOT touch sdr after invoking AppCallback -- client is allowed to dispose it from within callback function
1452 	}
1453 
DNSServiceRegister(DNSServiceRef * sdRef,DNSServiceFlags flags,uint32_t interfaceIndex,const char * name,const char * regtype,const char * domain,const char * host,uint16_t PortInNetworkByteOrder,uint16_t txtLen,const void * txtRecord,DNSServiceRegisterReply callBack,void * context)1454 DNSServiceErrorType DNSSD_API DNSServiceRegister
1455 	(
1456 	DNSServiceRef                       *sdRef,
1457 	DNSServiceFlags                     flags,
1458 	uint32_t                            interfaceIndex,
1459 	const char                          *name,
1460 	const char                          *regtype,
1461 	const char                          *domain,
1462 	const char                          *host,
1463 	uint16_t                            PortInNetworkByteOrder,
1464 	uint16_t                            txtLen,
1465 	const void                          *txtRecord,
1466 	DNSServiceRegisterReply             callBack,
1467 	void                                *context
1468 	)
1469 	{
1470 	char *ptr;
1471 	size_t len;
1472 	ipc_msg_hdr *hdr;
1473 	DNSServiceErrorType err;
1474 	union { uint16_t s; u_char b[2]; } port = { PortInNetworkByteOrder };
1475 
1476 	if (!name) name = "";
1477 	if (!regtype) return kDNSServiceErr_BadParam;
1478 	if (!domain) domain = "";
1479 	if (!host) host = "";
1480 	if (!txtRecord) txtRecord = (void*)"";
1481 
1482 	// No callback must have auto-rename
1483 	if (!callBack && (flags & kDNSServiceFlagsNoAutoRename)) return kDNSServiceErr_BadParam;
1484 
1485 	err = ConnectToServer(sdRef, flags, reg_service_request, callBack ? handle_regservice_response : NULL, callBack, context);
1486 	if (err) return err;	// On error ConnectToServer leaves *sdRef set to NULL
1487 
1488 	len = sizeof(DNSServiceFlags);
1489 	len += sizeof(uint32_t);  // interfaceIndex
1490 	len += strlen(name) + strlen(regtype) + strlen(domain) + strlen(host) + 4;
1491 	len += 2 * sizeof(uint16_t);  // port, txtLen
1492 	len += txtLen;
1493 
1494 	hdr = create_hdr(reg_service_request, &len, &ptr, (*sdRef)->primary ? 1 : 0, *sdRef);
1495 	if (!hdr) { DNSServiceRefDeallocate(*sdRef); *sdRef = NULL; return kDNSServiceErr_NoMemory; }
1496 	if (!callBack) hdr->ipc_flags |= IPC_FLAGS_NOREPLY;
1497 
1498 	put_flags(flags, &ptr);
1499 	put_uint32(interfaceIndex, &ptr);
1500 	put_string(name, &ptr);
1501 	put_string(regtype, &ptr);
1502 	put_string(domain, &ptr);
1503 	put_string(host, &ptr);
1504 	*ptr++ = port.b[0];
1505 	*ptr++ = port.b[1];
1506 	put_uint16(txtLen, &ptr);
1507 	put_rdata(txtLen, txtRecord, &ptr);
1508 
1509 	err = deliver_request(hdr, *sdRef);		// Will free hdr for us
1510 	if (err) { DNSServiceRefDeallocate(*sdRef); *sdRef = NULL; }
1511 	return err;
1512 	}
1513 
handle_enumeration_response(DNSServiceOp * const sdr,const CallbackHeader * const cbh,const char * data,const char * const end)1514 static void handle_enumeration_response(DNSServiceOp *const sdr, const CallbackHeader *const cbh, const char *data, const char *const end)
1515 	{
1516 	char domain[kDNSServiceMaxDomainName];
1517 	get_string(&data, end, domain, kDNSServiceMaxDomainName);
1518 	if (!data) syslog(LOG_WARNING, "dnssd_clientstub handle_enumeration_response: error reading result from daemon");
1519 	else ((DNSServiceDomainEnumReply)sdr->AppCallback)(sdr, cbh->cb_flags, cbh->cb_interface, cbh->cb_err, domain, sdr->AppContext);
1520 	// MUST NOT touch sdr after invoking AppCallback -- client is allowed to dispose it from within callback function
1521 	}
1522 
DNSServiceEnumerateDomains(DNSServiceRef * sdRef,DNSServiceFlags flags,uint32_t interfaceIndex,DNSServiceDomainEnumReply callBack,void * context)1523 DNSServiceErrorType DNSSD_API DNSServiceEnumerateDomains
1524 	(
1525 	DNSServiceRef             *sdRef,
1526 	DNSServiceFlags            flags,
1527 	uint32_t                   interfaceIndex,
1528 	DNSServiceDomainEnumReply  callBack,
1529 	void                      *context
1530 	)
1531 	{
1532 	char *ptr;
1533 	size_t len;
1534 	ipc_msg_hdr *hdr;
1535 	DNSServiceErrorType err;
1536 
1537 	int f1 = (flags & kDNSServiceFlagsBrowseDomains) != 0;
1538 	int f2 = (flags & kDNSServiceFlagsRegistrationDomains) != 0;
1539 	if (f1 + f2 != 1) return kDNSServiceErr_BadParam;
1540 
1541 	err = ConnectToServer(sdRef, flags, enumeration_request, handle_enumeration_response, callBack, context);
1542 	if (err) return err;	// On error ConnectToServer leaves *sdRef set to NULL
1543 
1544 	len = sizeof(DNSServiceFlags);
1545 	len += sizeof(uint32_t);
1546 
1547 	hdr = create_hdr(enumeration_request, &len, &ptr, (*sdRef)->primary ? 1 : 0, *sdRef);
1548 	if (!hdr) { DNSServiceRefDeallocate(*sdRef); *sdRef = NULL; return kDNSServiceErr_NoMemory; }
1549 
1550 	put_flags(flags, &ptr);
1551 	put_uint32(interfaceIndex, &ptr);
1552 
1553 	err = deliver_request(hdr, *sdRef);		// Will free hdr for us
1554 	if (err) { DNSServiceRefDeallocate(*sdRef); *sdRef = NULL; }
1555 	return err;
1556 	}
1557 
ConnectionResponse(DNSServiceOp * const sdr,const CallbackHeader * const cbh,const char * const data,const char * const end)1558 static void ConnectionResponse(DNSServiceOp *const sdr, const CallbackHeader *const cbh, const char *const data, const char *const end)
1559 	{
1560 	DNSRecordRef rref = cbh->ipc_hdr.client_context.context;
1561 	(void)data; // Unused
1562 
1563 	//printf("ConnectionResponse got %d\n", cbh->ipc_hdr.op);
1564 	if (cbh->ipc_hdr.op != reg_record_reply_op)
1565 		{
1566 		// When using kDNSServiceFlagsShareConnection, need to search the list of associated DNSServiceOps
1567 		// to find the one this response is intended for, and then call through to its ProcessReply handler.
1568 		// We start with our first subordinate DNSServiceRef -- don't want to accidentally match the parent DNSServiceRef.
1569 		DNSServiceOp *op = sdr->next;
1570 		while (op && (op->uid.u32[0] != cbh->ipc_hdr.client_context.u32[0] || op->uid.u32[1] != cbh->ipc_hdr.client_context.u32[1]))
1571 			op = op->next;
1572 		// Note: We may sometimes not find a matching DNSServiceOp, in the case where the client has
1573 		// cancelled the subordinate DNSServiceOp, but there are still messages in the pipeline from the daemon
1574 		if (op && op->ProcessReply) op->ProcessReply(op, cbh, data, end);
1575 		// WARNING: Don't touch op or sdr after this -- client may have called DNSServiceRefDeallocate
1576 		return;
1577 		}
1578 
1579 	if (sdr->op == connection_request)
1580 		rref->AppCallback(rref->sdr, rref, cbh->cb_flags, cbh->cb_err, rref->AppContext);
1581 	else
1582 		{
1583 		syslog(LOG_WARNING, "dnssd_clientstub ConnectionResponse: sdr->op != connection_request");
1584 		rref->AppCallback(rref->sdr, rref, 0, kDNSServiceErr_Unknown, rref->AppContext);
1585 		}
1586 	// MUST NOT touch sdr after invoking AppCallback -- client is allowed to dispose it from within callback function
1587 	}
1588 
DNSServiceCreateConnection(DNSServiceRef * sdRef)1589 DNSServiceErrorType DNSSD_API DNSServiceCreateConnection(DNSServiceRef *sdRef)
1590 	{
1591 	char *ptr;
1592 	size_t len = 0;
1593 	ipc_msg_hdr *hdr;
1594 	DNSServiceErrorType err = ConnectToServer(sdRef, 0, connection_request, ConnectionResponse, NULL, NULL);
1595 	if (err) return err;	// On error ConnectToServer leaves *sdRef set to NULL
1596 
1597 	hdr = create_hdr(connection_request, &len, &ptr, 0, *sdRef);
1598 	if (!hdr) { DNSServiceRefDeallocate(*sdRef); *sdRef = NULL; return kDNSServiceErr_NoMemory; }
1599 
1600 	err = deliver_request(hdr, *sdRef);		// Will free hdr for us
1601 	if (err) { DNSServiceRefDeallocate(*sdRef); *sdRef = NULL; }
1602 	return err;
1603 	}
1604 
DNSServiceRegisterRecord(DNSServiceRef sdRef,DNSRecordRef * RecordRef,DNSServiceFlags flags,uint32_t interfaceIndex,const char * fullname,uint16_t rrtype,uint16_t rrclass,uint16_t rdlen,const void * rdata,uint32_t ttl,DNSServiceRegisterRecordReply callBack,void * context)1605 DNSServiceErrorType DNSSD_API DNSServiceRegisterRecord
1606 	(
1607 	DNSServiceRef                  sdRef,
1608 	DNSRecordRef                  *RecordRef,
1609 	DNSServiceFlags                flags,
1610 	uint32_t                       interfaceIndex,
1611 	const char                    *fullname,
1612 	uint16_t                       rrtype,
1613 	uint16_t                       rrclass,
1614 	uint16_t                       rdlen,
1615 	const void                    *rdata,
1616 	uint32_t                       ttl,
1617 	DNSServiceRegisterRecordReply  callBack,
1618 	void                          *context
1619 	)
1620 	{
1621 	char *ptr;
1622 	size_t len;
1623 	ipc_msg_hdr *hdr = NULL;
1624 	DNSRecordRef rref = NULL;
1625 	DNSRecord **p;
1626 	int f1 = (flags & kDNSServiceFlagsShared) != 0;
1627 	int f2 = (flags & kDNSServiceFlagsUnique) != 0;
1628 	if (f1 + f2 != 1) return kDNSServiceErr_BadParam;
1629 
1630 	if (!sdRef) { syslog(LOG_WARNING, "dnssd_clientstub DNSServiceRegisterRecord called with NULL DNSServiceRef"); return kDNSServiceErr_BadParam; }
1631 
1632 	if (!DNSServiceRefValid(sdRef))
1633 		{
1634 		syslog(LOG_WARNING, "dnssd_clientstub DNSServiceRegisterRecord called with invalid DNSServiceRef %p %08X %08X", sdRef, sdRef->sockfd, sdRef->validator);
1635 		return kDNSServiceErr_BadReference;
1636 		}
1637 
1638 	if (sdRef->op != connection_request)
1639 		{
1640 		syslog(LOG_WARNING, "dnssd_clientstub DNSServiceRegisterRecord called with non-DNSServiceCreateConnection DNSServiceRef %p %d", sdRef, sdRef->op);
1641 		return kDNSServiceErr_BadReference;
1642 		}
1643 
1644 	*RecordRef = NULL;
1645 
1646 	len = sizeof(DNSServiceFlags);
1647 	len += 2 * sizeof(uint32_t);  // interfaceIndex, ttl
1648 	len += 3 * sizeof(uint16_t);  // rrtype, rrclass, rdlen
1649 	len += strlen(fullname) + 1;
1650 	len += rdlen;
1651 
1652 	hdr = create_hdr(reg_record_request, &len, &ptr, 1, sdRef);
1653 	if (!hdr) return kDNSServiceErr_NoMemory;
1654 
1655 	put_flags(flags, &ptr);
1656 	put_uint32(interfaceIndex, &ptr);
1657 	put_string(fullname, &ptr);
1658 	put_uint16(rrtype, &ptr);
1659 	put_uint16(rrclass, &ptr);
1660 	put_uint16(rdlen, &ptr);
1661 	put_rdata(rdlen, rdata, &ptr);
1662 	put_uint32(ttl, &ptr);
1663 
1664 	rref = malloc(sizeof(DNSRecord));
1665 	if (!rref) { free(hdr); return kDNSServiceErr_NoMemory; }
1666 	rref->AppContext = context;
1667 	rref->AppCallback = callBack;
1668 	rref->record_index = sdRef->max_index++;
1669 	rref->sdr = sdRef;
1670 	rref->recnext = NULL;
1671 	*RecordRef = rref;
1672 	hdr->client_context.context = rref;
1673 	hdr->reg_index = rref->record_index;
1674 
1675 	p = &(sdRef)->rec;
1676 	while (*p) p = &(*p)->recnext;
1677 	*p = rref;
1678 
1679 	return deliver_request(hdr, sdRef);		// Will free hdr for us
1680 	}
1681 
1682 // sdRef returned by DNSServiceRegister()
DNSServiceAddRecord(DNSServiceRef sdRef,DNSRecordRef * RecordRef,DNSServiceFlags flags,uint16_t rrtype,uint16_t rdlen,const void * rdata,uint32_t ttl)1683 DNSServiceErrorType DNSSD_API DNSServiceAddRecord
1684 	(
1685 	DNSServiceRef    sdRef,
1686 	DNSRecordRef    *RecordRef,
1687 	DNSServiceFlags  flags,
1688 	uint16_t         rrtype,
1689 	uint16_t         rdlen,
1690 	const void      *rdata,
1691 	uint32_t         ttl
1692 	)
1693 	{
1694 	ipc_msg_hdr *hdr;
1695 	size_t len = 0;
1696 	char *ptr;
1697 	DNSRecordRef rref;
1698 	DNSRecord **p;
1699 
1700 	if (!sdRef)     { syslog(LOG_WARNING, "dnssd_clientstub DNSServiceAddRecord called with NULL DNSServiceRef");        return kDNSServiceErr_BadParam; }
1701 	if (!RecordRef) { syslog(LOG_WARNING, "dnssd_clientstub DNSServiceAddRecord called with NULL DNSRecordRef pointer"); return kDNSServiceErr_BadParam; }
1702 	if (sdRef->op != reg_service_request)
1703 		{
1704 		syslog(LOG_WARNING, "dnssd_clientstub DNSServiceAddRecord called with non-DNSServiceRegister DNSServiceRef %p %d", sdRef, sdRef->op);
1705 		return kDNSServiceErr_BadReference;
1706 		}
1707 
1708 	if (!DNSServiceRefValid(sdRef))
1709 		{
1710 		syslog(LOG_WARNING, "dnssd_clientstub DNSServiceAddRecord called with invalid DNSServiceRef %p %08X %08X", sdRef, sdRef->sockfd, sdRef->validator);
1711 		return kDNSServiceErr_BadReference;
1712 		}
1713 
1714 	*RecordRef = NULL;
1715 
1716 	len += 2 * sizeof(uint16_t);  // rrtype, rdlen
1717 	len += rdlen;
1718 	len += sizeof(uint32_t);
1719 	len += sizeof(DNSServiceFlags);
1720 
1721 	hdr = create_hdr(add_record_request, &len, &ptr, 1, sdRef);
1722 	if (!hdr) return kDNSServiceErr_NoMemory;
1723 	put_flags(flags, &ptr);
1724 	put_uint16(rrtype, &ptr);
1725 	put_uint16(rdlen, &ptr);
1726 	put_rdata(rdlen, rdata, &ptr);
1727 	put_uint32(ttl, &ptr);
1728 
1729 	rref = malloc(sizeof(DNSRecord));
1730 	if (!rref) { free(hdr); return kDNSServiceErr_NoMemory; }
1731 	rref->AppContext = NULL;
1732 	rref->AppCallback = NULL;
1733 	rref->record_index = sdRef->max_index++;
1734 	rref->sdr = sdRef;
1735 	rref->recnext = NULL;
1736 	*RecordRef = rref;
1737 	hdr->reg_index = rref->record_index;
1738 
1739 	p = &(sdRef)->rec;
1740 	while (*p) p = &(*p)->recnext;
1741 	*p = rref;
1742 
1743 	return deliver_request(hdr, sdRef);		// Will free hdr for us
1744 	}
1745 
1746 // DNSRecordRef returned by DNSServiceRegisterRecord or DNSServiceAddRecord
DNSServiceUpdateRecord(DNSServiceRef sdRef,DNSRecordRef RecordRef,DNSServiceFlags flags,uint16_t rdlen,const void * rdata,uint32_t ttl)1747 DNSServiceErrorType DNSSD_API DNSServiceUpdateRecord
1748 	(
1749 	DNSServiceRef    sdRef,
1750 	DNSRecordRef     RecordRef,
1751 	DNSServiceFlags  flags,
1752 	uint16_t         rdlen,
1753 	const void      *rdata,
1754 	uint32_t         ttl
1755 	)
1756 	{
1757 	ipc_msg_hdr *hdr;
1758 	size_t len = 0;
1759 	char *ptr;
1760 
1761 	if (!sdRef) { syslog(LOG_WARNING, "dnssd_clientstub DNSServiceUpdateRecord called with NULL DNSServiceRef"); return kDNSServiceErr_BadParam; }
1762 
1763 	if (!DNSServiceRefValid(sdRef))
1764 		{
1765 		syslog(LOG_WARNING, "dnssd_clientstub DNSServiceUpdateRecord called with invalid DNSServiceRef %p %08X %08X", sdRef, sdRef->sockfd, sdRef->validator);
1766 		return kDNSServiceErr_BadReference;
1767 		}
1768 
1769 	// Note: RecordRef is allowed to be NULL
1770 
1771 	len += sizeof(uint16_t);
1772 	len += rdlen;
1773 	len += sizeof(uint32_t);
1774 	len += sizeof(DNSServiceFlags);
1775 
1776 	hdr = create_hdr(update_record_request, &len, &ptr, 1, sdRef);
1777 	if (!hdr) return kDNSServiceErr_NoMemory;
1778 	hdr->reg_index = RecordRef ? RecordRef->record_index : TXT_RECORD_INDEX;
1779 	put_flags(flags, &ptr);
1780 	put_uint16(rdlen, &ptr);
1781 	put_rdata(rdlen, rdata, &ptr);
1782 	put_uint32(ttl, &ptr);
1783 	return deliver_request(hdr, sdRef);		// Will free hdr for us
1784 	}
1785 
DNSServiceRemoveRecord(DNSServiceRef sdRef,DNSRecordRef RecordRef,DNSServiceFlags flags)1786 DNSServiceErrorType DNSSD_API DNSServiceRemoveRecord
1787 	(
1788 	DNSServiceRef    sdRef,
1789 	DNSRecordRef     RecordRef,
1790 	DNSServiceFlags  flags
1791 	)
1792 	{
1793 	ipc_msg_hdr *hdr;
1794 	size_t len = 0;
1795 	char *ptr;
1796 	DNSServiceErrorType err;
1797 
1798 	if (!sdRef)            { syslog(LOG_WARNING, "dnssd_clientstub DNSServiceRemoveRecord called with NULL DNSServiceRef"); return kDNSServiceErr_BadParam; }
1799 	if (!RecordRef)        { syslog(LOG_WARNING, "dnssd_clientstub DNSServiceRemoveRecord called with NULL DNSRecordRef");  return kDNSServiceErr_BadParam; }
1800 	if (!sdRef->max_index) { syslog(LOG_WARNING, "dnssd_clientstub DNSServiceRemoveRecord called with bad DNSServiceRef");  return kDNSServiceErr_BadReference; }
1801 
1802 	if (!DNSServiceRefValid(sdRef))
1803 		{
1804 		syslog(LOG_WARNING, "dnssd_clientstub DNSServiceRemoveRecord called with invalid DNSServiceRef %p %08X %08X", sdRef, sdRef->sockfd, sdRef->validator);
1805 		return kDNSServiceErr_BadReference;
1806 		}
1807 
1808 	len += sizeof(flags);
1809 	hdr = create_hdr(remove_record_request, &len, &ptr, 1, sdRef);
1810 	if (!hdr) return kDNSServiceErr_NoMemory;
1811 	hdr->reg_index = RecordRef->record_index;
1812 	put_flags(flags, &ptr);
1813 	err = deliver_request(hdr, sdRef);		// Will free hdr for us
1814 	if (!err)
1815 		{
1816 		// This RecordRef could have been allocated in DNSServiceRegisterRecord or DNSServiceAddRecord.
1817 		// If so, delink from the list before freeing
1818 		DNSRecord **p = &sdRef->rec;
1819 		while (*p && *p != RecordRef) p = &(*p)->recnext;
1820 		if (*p) *p = RecordRef->recnext;
1821 		free(RecordRef);
1822 		}
1823 	return err;
1824 	}
1825 
DNSServiceReconfirmRecord(DNSServiceFlags flags,uint32_t interfaceIndex,const char * fullname,uint16_t rrtype,uint16_t rrclass,uint16_t rdlen,const void * rdata)1826 DNSServiceErrorType DNSSD_API DNSServiceReconfirmRecord
1827 	(
1828 	DNSServiceFlags  flags,
1829 	uint32_t         interfaceIndex,
1830 	const char      *fullname,
1831 	uint16_t         rrtype,
1832 	uint16_t         rrclass,
1833 	uint16_t         rdlen,
1834 	const void      *rdata
1835 	)
1836 	{
1837 	char *ptr;
1838 	size_t len;
1839 	ipc_msg_hdr *hdr;
1840 	DNSServiceOp *tmp;
1841 
1842 	DNSServiceErrorType err = ConnectToServer(&tmp, flags, reconfirm_record_request, NULL, NULL, NULL);
1843 	if (err) return err;
1844 
1845 	len = sizeof(DNSServiceFlags);
1846 	len += sizeof(uint32_t);
1847 	len += strlen(fullname) + 1;
1848 	len += 3 * sizeof(uint16_t);
1849 	len += rdlen;
1850 	hdr = create_hdr(reconfirm_record_request, &len, &ptr, 0, tmp);
1851 	if (!hdr) { DNSServiceRefDeallocate(tmp); return kDNSServiceErr_NoMemory; }
1852 
1853 	put_flags(flags, &ptr);
1854 	put_uint32(interfaceIndex, &ptr);
1855 	put_string(fullname, &ptr);
1856 	put_uint16(rrtype, &ptr);
1857 	put_uint16(rrclass, &ptr);
1858 	put_uint16(rdlen, &ptr);
1859 	put_rdata(rdlen, rdata, &ptr);
1860 
1861 	err = deliver_request(hdr, tmp);		// Will free hdr for us
1862 	DNSServiceRefDeallocate(tmp);
1863 	return err;
1864 	}
1865 
handle_port_mapping_response(DNSServiceOp * const sdr,const CallbackHeader * const cbh,const char * data,const char * const end)1866 static void handle_port_mapping_response(DNSServiceOp *const sdr, const CallbackHeader *const cbh, const char *data, const char *const end)
1867 	{
1868 	union { uint32_t l; u_char b[4]; } addr;
1869 	uint8_t protocol;
1870 	union { uint16_t s; u_char b[2]; } internalPort;
1871 	union { uint16_t s; u_char b[2]; } externalPort;
1872 	uint32_t ttl;
1873 
1874 	if (!data || data + 13 > end) goto fail;
1875 
1876 	addr        .b[0] = *data++;
1877 	addr        .b[1] = *data++;
1878 	addr        .b[2] = *data++;
1879 	addr        .b[3] = *data++;
1880 	protocol          = *data++;
1881 	internalPort.b[0] = *data++;
1882 	internalPort.b[1] = *data++;
1883 	externalPort.b[0] = *data++;
1884 	externalPort.b[1] = *data++;
1885 	ttl               = get_uint32(&data, end);
1886 	if (!data) goto fail;
1887 
1888 	((DNSServiceNATPortMappingReply)sdr->AppCallback)(sdr, cbh->cb_flags, cbh->cb_interface, cbh->cb_err, addr.l, protocol, internalPort.s, externalPort.s, ttl, sdr->AppContext);
1889 	return;
1890 	// MUST NOT touch sdr after invoking AppCallback -- client is allowed to dispose it from within callback function
1891 
1892 fail:
1893 	syslog(LOG_WARNING, "dnssd_clientstub handle_port_mapping_response: error reading result from daemon");
1894 	}
1895 
DNSServiceNATPortMappingCreate(DNSServiceRef * sdRef,DNSServiceFlags flags,uint32_t interfaceIndex,uint32_t protocol,uint16_t internalPortInNetworkByteOrder,uint16_t externalPortInNetworkByteOrder,uint32_t ttl,DNSServiceNATPortMappingReply callBack,void * context)1896 DNSServiceErrorType DNSSD_API DNSServiceNATPortMappingCreate
1897 	(
1898 	DNSServiceRef                       *sdRef,
1899 	DNSServiceFlags                     flags,
1900 	uint32_t                            interfaceIndex,
1901 	uint32_t                            protocol,     /* TCP and/or UDP */
1902 	uint16_t                            internalPortInNetworkByteOrder,
1903 	uint16_t                            externalPortInNetworkByteOrder,
1904 	uint32_t                            ttl,          /* time to live in seconds */
1905 	DNSServiceNATPortMappingReply       callBack,
1906 	void                                *context      /* may be NULL */
1907 	)
1908 	{
1909 	char *ptr;
1910 	size_t len;
1911 	ipc_msg_hdr *hdr;
1912 	union { uint16_t s; u_char b[2]; } internalPort = { internalPortInNetworkByteOrder };
1913 	union { uint16_t s; u_char b[2]; } externalPort = { externalPortInNetworkByteOrder };
1914 
1915 	DNSServiceErrorType err = ConnectToServer(sdRef, flags, port_mapping_request, handle_port_mapping_response, callBack, context);
1916 	if (err) return err;	// On error ConnectToServer leaves *sdRef set to NULL
1917 
1918 	len = sizeof(flags);
1919 	len += sizeof(interfaceIndex);
1920 	len += sizeof(protocol);
1921 	len += sizeof(internalPort);
1922 	len += sizeof(externalPort);
1923 	len += sizeof(ttl);
1924 
1925 	hdr = create_hdr(port_mapping_request, &len, &ptr, (*sdRef)->primary ? 1 : 0, *sdRef);
1926 	if (!hdr) { DNSServiceRefDeallocate(*sdRef); *sdRef = NULL; return kDNSServiceErr_NoMemory; }
1927 
1928 	put_flags(flags, &ptr);
1929 	put_uint32(interfaceIndex, &ptr);
1930 	put_uint32(protocol, &ptr);
1931 	*ptr++ = internalPort.b[0];
1932 	*ptr++ = internalPort.b[1];
1933 	*ptr++ = externalPort.b[0];
1934 	*ptr++ = externalPort.b[1];
1935 	put_uint32(ttl, &ptr);
1936 
1937 	err = deliver_request(hdr, *sdRef);		// Will free hdr for us
1938 	if (err) { DNSServiceRefDeallocate(*sdRef); *sdRef = NULL; }
1939 	return err;
1940 	}
1941 
1942 #if _DNS_SD_LIBDISPATCH
DNSServiceSetDispatchQueue(DNSServiceRef service,dispatch_queue_t queue)1943 DNSServiceErrorType DNSSD_API DNSServiceSetDispatchQueue
1944 	(
1945 	DNSServiceRef service,
1946 	dispatch_queue_t queue
1947 	)
1948 	{
1949 	int dnssd_fd  = DNSServiceRefSockFD(service);
1950 	if (dnssd_fd == dnssd_InvalidSocket) return kDNSServiceErr_BadParam;
1951 	if (!queue)
1952 		{
1953 		syslog(LOG_WARNING, "dnssd_clientstub: DNSServiceSetDispatchQueue dispatch queue NULL");
1954 		return kDNSServiceErr_BadParam;
1955 		}
1956 	if (service->disp_queue)
1957 		{
1958 		syslog(LOG_WARNING, "dnssd_clientstub DNSServiceSetDispatchQueue dispatch queue set already");
1959 		return kDNSServiceErr_BadParam;
1960 		}
1961 	if (service->disp_source)
1962 		{
1963 		syslog(LOG_WARNING, "DNSServiceSetDispatchQueue dispatch source set already");
1964 		return kDNSServiceErr_BadParam;
1965 		}
1966 	service->disp_source = dispatch_source_create(DISPATCH_SOURCE_TYPE_READ, dnssd_fd, 0, queue);
1967 	if (!service->disp_source)
1968 		{
1969 		syslog(LOG_WARNING, "DNSServiceSetDispatchQueue dispatch_source_create failed");
1970 		return kDNSServiceErr_NoMemory;
1971 		}
1972 	service->disp_queue = queue;
1973 	dispatch_source_set_event_handler(service->disp_source, ^{DNSServiceProcessResult(service);});
1974 	dispatch_source_set_cancel_handler(service->disp_source, ^{dnssd_close(dnssd_fd);});
1975 	dispatch_resume(service->disp_source);
1976 	return kDNSServiceErr_NoError;
1977 	}
1978 #endif // _DNS_SD_LIBDISPATCH
1979