mDNSShared/dnssd_ipc.h

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