xref: /illumos-gate/usr/src/contrib/mDNSResponder/mDNSShared/dnssd_ipc.h (revision d4039345c8fe6e54a31d17d91e86e393fdcf401b)
1 /* -*- Mode: C; tab-width: 4 -*-
2  *
3  * Copyright (c) 2003-2020 Apple 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 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
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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_socklen_t      int
45 #   define dnssd_close(sock)    closesocket(sock)
46 #   define dnssd_errno          WSAGetLastError()
47 #   define dnssd_strerror(X)    win32_strerror(X)
48 #   define ssize_t              int
49 #   define getpid               _getpid
50 #   define unlink               _unlink
51 extern char *win32_strerror(int inErrorCode);
52 #else
53 #   include <sys/types.h>
54 #   include <unistd.h>
55 #   include <sys/un.h>
56 #   include <string.h>
57 #   include <stdio.h>
58 #   include <stdlib.h>
59 #   include <sys/stat.h>
60 #   include <sys/socket.h>
61 #   include <netinet/in.h>
62 #   include <arpa/inet.h>
63 #   define dnssd_InvalidSocket  -1
64 #   define dnssd_SocketValid(s) ((s) >= 0)
65 #   define dnssd_EWOULDBLOCK    EWOULDBLOCK
66 #   define dnssd_EINTR          EINTR
67 #   define dnssd_ECONNRESET     ECONNRESET
68 #   define dnssd_EPIPE          EPIPE
69 #   define dnssd_socklen_t      unsigned int
70 #   define dnssd_close(sock)    close(sock)
71 #   define dnssd_errno          errno
72 #   define dnssd_strerror(X)    strerror(X)
73 #endif
74 
75 #if defined(USE_TCP_LOOPBACK)
76 #   define AF_DNSSD             AF_INET
77 #   define MDNS_TCP_SERVERADDR  "127.0.0.1"
78 #   define MDNS_TCP_SERVERPORT  5354
79 #   define LISTENQ              5
80 #   define dnssd_sockaddr_t     struct sockaddr_in
81 #else
82 #   define AF_DNSSD             AF_LOCAL
83 #   ifndef MDNS_UDS_SERVERPATH
84 #       define MDNS_UDS_SERVERPATH  "/var/run/mDNSResponder"
85 #   endif
86 #   define MDNS_UDS_SERVERPATH_ENVVAR "DNSSD_UDS_PATH"
87 #   define LISTENQ              100
88 // longest legal control path length
89 #   define MAX_CTLPATH          (sizeof(((struct sockaddr_un*)0)->sun_path))
90 #   define dnssd_sockaddr_t     struct sockaddr_un
91 #endif
92 
93 // Compatibility workaround
94 #ifndef AF_LOCAL
95 #define AF_LOCAL    AF_UNIX
96 #endif
97 
98 // General UDS constants
99 #define TXT_RECORD_INDEX ((uint32_t)(-1))   // record index for default text record
100 
101 // IPC data encoding constants and types
102 #define VERSION 1
103 #define IPC_FLAGS_NOREPLY       (1U << 0) // Set flag if no asynchronous replies are to be sent to client.
104 #define IPC_FLAGS_TRAILING_TLVS (1U << 1) // Set flag if TLVs follow the standard request data.
105 
106 #define IPC_TLV_TYPE_RESOLVER_CONFIG_PLIST_DATA 1   // An nw_resolver_config as a binary property list.
107 #define IPC_TLV_TYPE_REQUIRE_PRIVACY            2   // A uint8. Non-zero means privacy is required, zero means not required.
108 
109 // Structure packing macro. If we're not using GNUC, it's not fatal. Most compilers naturally pack the on-the-wire
110 // structures correctly anyway, so a plain "struct" is usually fine. In the event that structures are not packed
111 // correctly, our compile-time assertion checks will catch it and prevent inadvertent generation of non-working code.
112 #ifndef packedstruct
113  #if ((__GNUC__ > 2) || ((__GNUC__ == 2) && (__GNUC_MINOR__ >= 9)))
114   #define packedstruct struct __attribute__((__packed__))
115   #define packedunion  union  __attribute__((__packed__))
116  #else
117   #define packedstruct struct
118   #define packedunion  union
119  #endif
120 #endif
121 
122 typedef enum
123 {
124     request_op_none = 0,    // No request yet received on this connection
125     connection_request = 1, // connected socket via DNSServiceConnect()
126     reg_record_request,     // reg/remove record only valid for connected sockets
127     remove_record_request,
128     enumeration_request,
129     reg_service_request,
130     browse_request,
131     resolve_request,
132     query_request,
133     reconfirm_record_request,
134     add_record_request,
135     update_record_request,
136     setdomain_request,      // Up to here is in Tiger and B4W 1.0.3
137     getproperty_request,    // New in B4W 1.0.4
138     port_mapping_request,   // New in Leopard and B4W 2.0
139     addrinfo_request,
140     send_bpf,               // New in SL
141     getpid_request,
142     release_request,
143     connection_delegate_request,
144 
145     cancel_request = 63
146 } request_op_t;
147 
148 typedef enum
149 {
150     enumeration_reply_op = 64,
151     reg_service_reply_op,
152     browse_reply_op,
153     resolve_reply_op,
154     query_reply_op,
155     reg_record_reply_op,    // Up to here is in Tiger and B4W 1.0.3
156     getproperty_reply_op,   // New in B4W 1.0.4
157     port_mapping_reply_op,  // New in Leopard and B4W 2.0
158     addrinfo_reply_op
159 } reply_op_t;
160 
161 #if defined(_WIN64)
162 #   pragma pack(push,4)
163 #elif !defined(__GNUC__)
164 #   pragma pack(1)
165 #endif
166 
167 // Define context object big enough to hold a 64-bit pointer,
168 // to accomodate 64-bit clients communicating with 32-bit daemon.
169 // There's no reason for the daemon to ever be a 64-bit process, but its clients might be
170 typedef packedunion
171 {
172     void *context;
173     uint32_t u32[2];
174 } client_context_t;
175 
176 typedef packedstruct
177 {
178     uint32_t version;
179     uint32_t datalen;
180     uint32_t ipc_flags;
181     uint32_t op;        // request_op_t or reply_op_t
182     client_context_t client_context; // context passed from client, returned by server in corresponding reply
183     uint32_t reg_index;            // identifier for a record registered via DNSServiceRegisterRecord() on a
184     // socket connected by DNSServiceCreateConnection().  Must be unique in the scope of the connection, such that and
185     // index/socket pair uniquely identifies a record.  (Used to select records for removal by DNSServiceRemoveRecord())
186 } ipc_msg_hdr;
187 
188 #if defined(_WIN64)
189 #   pragma pack(pop)
190 #elif !defined(__GNUC__)
191 #   pragma pack()
192 #endif
193 
194 // routines to write to and extract data from message buffers.
195 // caller responsible for bounds checking.
196 // ptr is the address of the pointer to the start of the field.
197 // it is advanced to point to the next field, or the end of the message
198 
199 void put_uint32(const uint32_t l, char **ptr);
200 uint32_t get_uint32(const char **ptr, const char *end);
201 
202 void put_uint16(uint16_t s, char **ptr);
203 uint16_t get_uint16(const char **ptr, const char *end);
204 
205 #define put_flags put_uint32
206 #define get_flags get_uint32
207 
208 #define put_error_code put_uint32
209 #define get_error_code get_uint32
210 
211 int put_string(const char *str, char **ptr);
212 int get_string(const char **ptr, const char *const end, char *buffer, int buflen);
213 
214 void put_rdata(const int rdlen, const unsigned char *rdata, char **ptr);
215 const char *get_rdata(const char **ptr, const char *end, int rdlen);  // return value is rdata pointed to by *ptr -
216 // rdata is not copied from buffer.
217 
218 #if APPLE_OSX_mDNSResponder
219 size_t get_required_tlv16_length(const uint16_t valuelen);
220 void put_tlv16(const uint16_t type, const uint16_t length, const uint8_t *value, char **ptr);
221 #endif
222 
223 void ConvertHeaderBytes(ipc_msg_hdr *hdr);
224 
225 struct CompileTimeAssertionChecks_dnssd_ipc
226 {
227     // Check that the compiler generated our on-the-wire packet format structure definitions
228     // properly packed, without adding padding bytes to align fields on 32-bit or 64-bit boundaries.
229     char assert0[(sizeof(client_context_t) ==  8) ? 1 : -1];
230     char assert1[(sizeof(ipc_msg_hdr)      == 28) ? 1 : -1];
231 };
232 
233 #endif // DNSSD_IPC_H
234