mDNSShared/dnssd_ipc.h

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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_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 LISTENQ              100
  89 // longest legal control path length
  90 #   define MAX_CTLPATH          256
  91 #   define dnssd_sockaddr_t     struct sockaddr_un
  92 #endif
  93
  94 // Compatibility workaround
  95 #ifndef AF_LOCAL
  96 #define AF_LOCAL    AF_UNIX
  97 #endif
  98
  99 // General UDS constants
 100 #define TXT_RECORD_INDEX ((uint32_t)(-1))   // record index for default text record
 101
 102 // IPC data encoding constants and types
 103 #define VERSION 1
 104 #define IPC_FLAGS_NOREPLY 1 // set flag if no asynchronous replies are to be sent to client
 105
 106 // Structure packing macro. If we're not using GNUC, it's not fatal. Most compilers naturally pack the on-the-wire
 107 // structures correctly anyway, so a plain "struct" is usually fine. In the event that structures are not packed
 108 // correctly, our compile-time assertion checks will catch it and prevent inadvertent generation of non-working code.
 109 #ifndef packedstruct
 110  #if ((__GNUC__ > 2) || ((__GNUC__ == 2) && (__GNUC_MINOR__ >= 9)))
 111   #define packedstruct struct __attribute__((__packed__))
 112   #define packedunion  union  __attribute__((__packed__))
 113  #else
 114   #define packedstruct struct
 115   #define packedunion  union
 116  #endif
 117 #endif
 118
 119 typedef enum
 120 {
 121     request_op_none = 0,    // No request yet received on this connection
 122     connection_request = 1, // connected socket via DNSServiceConnect()
 123     reg_record_request,     // reg/remove record only valid for connected sockets
 124     remove_record_request,
 125     enumeration_request,
 126     reg_service_request,
 127     browse_request,
 128     resolve_request,
 129     query_request,
 130     reconfirm_record_request,
 131     add_record_request,
 132     update_record_request,
 133     setdomain_request,      // Up to here is in Tiger and B4W 1.0.3
 134     getproperty_request,    // New in B4W 1.0.4
 135     port_mapping_request,   // New in Leopard and B4W 2.0
 136     addrinfo_request,
 137     send_bpf,               // New in SL
 138     release_request,
 139
 140     cancel_request = 63
 141 } request_op_t;
 142
 143 typedef enum
 144 {
 145     enumeration_reply_op = 64,
 146     reg_service_reply_op,
 147     browse_reply_op,
 148     resolve_reply_op,
 149     query_reply_op,
 150     reg_record_reply_op,    // Up to here is in Tiger and B4W 1.0.3
 151     getproperty_reply_op,   // New in B4W 1.0.4
 152     port_mapping_reply_op,  // New in Leopard and B4W 2.0
 153     addrinfo_reply_op
 154 } reply_op_t;
 155
 156 #if defined(_WIN64)
 157 #   pragma pack(push,4)
 158 #endif
 159
 160 // Define context object big enough to hold a 64-bit pointer,
 161 // to accomodate 64-bit clients communicating with 32-bit daemon.
 162 // There's no reason for the daemon to ever be a 64-bit process, but its clients might be
 163 typedef packedunion
 164 {
 165     void *context;
 166     uint32_t u32[2];
 167 } client_context_t;
 168
 169 typedef packedstruct
 170 {
 171     uint32_t version;
 172     uint32_t datalen;
 173     uint32_t ipc_flags;
 174     uint32_t op;        // request_op_t or reply_op_t
 175     client_context_t client_context; // context passed from client, returned by server in corresponding reply
 176     uint32_t reg_index;            // identifier for a record registered via DNSServiceRegisterRecord() on a
 177     // socket connected by DNSServiceCreateConnection().  Must be unique in the scope of the connection, such that and
 178     // index/socket pair uniquely identifies a record.  (Used to select records for removal by DNSServiceRemoveRecord())
 179 } ipc_msg_hdr;
 180
 181 #if defined(_WIN64)
 182 #   pragma pack(pop)
 183 #endif
 184
 185 // routines to write to and extract data from message buffers.
 186 // caller responsible for bounds checking.
 187 // ptr is the address of the pointer to the start of the field.
 188 // it is advanced to point to the next field, or the end of the message
 189
 190 void put_uint32(const uint32_t l, char **ptr);
 191 uint32_t get_uint32(const char **ptr, const char *end);
 192
 193 void put_uint16(uint16_t s, char **ptr);
 194 uint16_t get_uint16(const char **ptr, const char *end);
 195
 196 #define put_flags put_uint32
 197 #define get_flags get_uint32
 198
 199 #define put_error_code put_uint32
 200 #define get_error_code get_uint32
 201
 202 int put_string(const char *str, char **ptr);
 203 int get_string(const char **ptr, const char *const end, char *buffer, int buflen);
 204
 205 void put_rdata(const int rdlen, const unsigned char *rdata, char **ptr);
 206 const char *get_rdata(const char **ptr, const char *end, int rdlen);  // return value is rdata pointed to by *ptr -
 207 // rdata is not copied from buffer.
 208
 209 void ConvertHeaderBytes(ipc_msg_hdr *hdr);
 210
 211 struct CompileTimeAssertionChecks_dnssd_ipc
 212 {
 213     // Check that the compiler generated our on-the-wire packet format structure definitions
 214     // properly packed, without adding padding bytes to align fields on 32-bit or 64-bit boundaries.
 215     char assert0[(sizeof(client_context_t) ==  8) ? 1 : -1];
 216     char assert1[(sizeof(ipc_msg_hdr)      == 28) ? 1 : -1];
 217 };
 218
 219 #endif // DNSSD_IPC_H