xref: /titanic_52/usr/src/lib/libdns_sd/common/dnssd_ipc.h (revision dcdfe824b3dff2df12578b936adf1daf000aa129)
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 #ifndef DNSSD_IPC_H
30 #define DNSSD_IPC_H
31 
32 #include "dns_sd.h"
33 
34 //
35 // Common cross platform services
36 //
37 #if defined(WIN32)
38 #   include <winsock2.h>
39 #   define dnssd_InvalidSocket  INVALID_SOCKET
40 #   define dnssd_SocketValid(s) ((s) != INVALID_SOCKET)
41 #   define dnssd_EWOULDBLOCK    WSAEWOULDBLOCK
42 #   define dnssd_EINTR          WSAEINTR
43 #   define dnssd_ECONNRESET     WSAECONNRESET
44 #   define dnssd_sock_t         SOCKET
45 #   define dnssd_socklen_t      int
46 #   define dnssd_close(sock)    closesocket(sock)
47 #   define dnssd_errno          WSAGetLastError()
48 #   define dnssd_strerror(X)    win32_strerror(X)
49 #   define ssize_t              int
50 #   define getpid               _getpid
51 #   define unlink               _unlink
52 extern char *win32_strerror(int inErrorCode);
53 #else
54 #   include <sys/types.h>
55 #   include <unistd.h>
56 #   include <sys/un.h>
57 #   include <string.h>
58 #   include <stdio.h>
59 #   include <stdlib.h>
60 #   include <sys/stat.h>
61 #   include <sys/socket.h>
62 #   include <netinet/in.h>
63 #   include <arpa/inet.h>
64 #   define dnssd_InvalidSocket  -1
65 #   define dnssd_SocketValid(s) ((s) >= 0)
66 #   define dnssd_EWOULDBLOCK    EWOULDBLOCK
67 #   define dnssd_EINTR          EINTR
68 #   define dnssd_ECONNRESET     ECONNRESET
69 #   define dnssd_EPIPE          EPIPE
70 #   define dnssd_sock_t         int
71 #   define dnssd_socklen_t      unsigned int
72 #   define dnssd_close(sock)    close(sock)
73 #   define dnssd_errno          errno
74 #   define dnssd_strerror(X)    strerror(X)
75 #endif
76 
77 #if defined(USE_TCP_LOOPBACK)
78 #   define AF_DNSSD             AF_INET
79 #   define MDNS_TCP_SERVERADDR  "127.0.0.1"
80 #   define MDNS_TCP_SERVERPORT  5354
81 #   define LISTENQ              5
82 #   define dnssd_sockaddr_t     struct sockaddr_in
83 #else
84 #   define AF_DNSSD             AF_LOCAL
85 #   ifndef MDNS_UDS_SERVERPATH
86 #       define MDNS_UDS_SERVERPATH  "/var/run/mDNSResponder"
87 #   endif
88 #   define MDNS_UDS_SERVERPATH_ENVVAR "DNSSD_UDS_PATH"
89 #   define LISTENQ              100
90 // longest legal control path length
91 #   define MAX_CTLPATH          256
92 #   define dnssd_sockaddr_t     struct sockaddr_un
93 #endif
94 
95 // Compatibility workaround
96 #ifndef AF_LOCAL
97 #define AF_LOCAL    AF_UNIX
98 #endif
99 
100 // General UDS constants
101 #define TXT_RECORD_INDEX ((uint32_t)(-1))   // record index for default text record
102 
103 // IPC data encoding constants and types
104 #define VERSION 1
105 #define IPC_FLAGS_NOREPLY 1 // set flag if no asynchronous replies are to be sent to client
106 
107 // Structure packing macro. If we're not using GNUC, it's not fatal. Most compilers naturally pack the on-the-wire
108 // structures correctly anyway, so a plain "struct" is usually fine. In the event that structures are not packed
109 // correctly, our compile-time assertion checks will catch it and prevent inadvertent generation of non-working code.
110 #ifndef packedstruct
111  #if ((__GNUC__ > 2) || ((__GNUC__ == 2) && (__GNUC_MINOR__ >= 9)))
112   #define packedstruct struct __attribute__((__packed__))
113   #define packedunion  union  __attribute__((__packed__))
114  #else
115   #define packedstruct struct
116   #define packedunion  union
117  #endif
118 #endif
119 
120 typedef enum
121 {
122     request_op_none = 0,    // No request yet received on this connection
123     connection_request = 1, // connected socket via DNSServiceConnect()
124     reg_record_request,     // reg/remove record only valid for connected sockets
125     remove_record_request,
126     enumeration_request,
127     reg_service_request,
128     browse_request,
129     resolve_request,
130     query_request,
131     reconfirm_record_request,
132     add_record_request,
133     update_record_request,
134     setdomain_request,      // Up to here is in Tiger and B4W 1.0.3
135     getproperty_request,    // New in B4W 1.0.4
136     port_mapping_request,   // New in Leopard and B4W 2.0
137     addrinfo_request,
138     send_bpf,               // New in SL
139     getpid_request,
140     release_request,
141     connection_delegate_request,
142 
143     cancel_request = 63
144 } request_op_t;
145 
146 typedef enum
147 {
148     enumeration_reply_op = 64,
149     reg_service_reply_op,
150     browse_reply_op,
151     resolve_reply_op,
152     query_reply_op,
153     reg_record_reply_op,    // Up to here is in Tiger and B4W 1.0.3
154     getproperty_reply_op,   // New in B4W 1.0.4
155     port_mapping_reply_op,  // New in Leopard and B4W 2.0
156     addrinfo_reply_op
157 } reply_op_t;
158 
159 #if defined(_WIN64)
160 #   pragma pack(push,4)
161 #elif !defined(__GNUC__)
162 #   pragma pack(1)
163 #endif
164 
165 // Define context object big enough to hold a 64-bit pointer,
166 // to accomodate 64-bit clients communicating with 32-bit daemon.
167 // There's no reason for the daemon to ever be a 64-bit process, but its clients might be
168 typedef packedunion
169 {
170     void *context;
171     uint32_t u32[2];
172 } client_context_t;
173 
174 typedef packedstruct
175 {
176     uint32_t version;
177     uint32_t datalen;
178     uint32_t ipc_flags;
179     uint32_t op;        // request_op_t or reply_op_t
180     client_context_t client_context; // context passed from client, returned by server in corresponding reply
181     uint32_t reg_index;            // identifier for a record registered via DNSServiceRegisterRecord() on a
182     // socket connected by DNSServiceCreateConnection().  Must be unique in the scope of the connection, such that and
183     // index/socket pair uniquely identifies a record.  (Used to select records for removal by DNSServiceRemoveRecord())
184 } ipc_msg_hdr;
185 
186 #if defined(_WIN64)
187 #   pragma pack(pop)
188 #elif !defined(__GNUC__)
189 #   pragma pack()
190 #endif
191 
192 // routines to write to and extract data from message buffers.
193 // caller responsible for bounds checking.
194 // ptr is the address of the pointer to the start of the field.
195 // it is advanced to point to the next field, or the end of the message
196 
197 void put_uint32(const uint32_t l, char **ptr);
198 uint32_t get_uint32(const char **ptr, const char *end);
199 
200 void put_uint16(uint16_t s, char **ptr);
201 uint16_t get_uint16(const char **ptr, const char *end);
202 
203 #define put_flags put_uint32
204 #define get_flags get_uint32
205 
206 #define put_error_code put_uint32
207 #define get_error_code get_uint32
208 
209 int put_string(const char *str, char **ptr);
210 int get_string(const char **ptr, const char *const end, char *buffer, int buflen);
211 
212 void put_rdata(const int rdlen, const unsigned char *rdata, char **ptr);
213 const char *get_rdata(const char **ptr, const char *end, int rdlen);  // return value is rdata pointed to by *ptr -
214 // rdata is not copied from buffer.
215 
216 void ConvertHeaderBytes(ipc_msg_hdr *hdr);
217 
218 struct CompileTimeAssertionChecks_dnssd_ipc
219 {
220     // Check that the compiler generated our on-the-wire packet format structure definitions
221     // properly packed, without adding padding bytes to align fields on 32-bit or 64-bit boundaries.
222     char assert0[(sizeof(client_context_t) ==  8) ? 1 : -1];
223     char assert1[(sizeof(ipc_msg_hdr)      == 28) ? 1 : -1];
224 };
225 
226 #endif // DNSSD_IPC_H
227