bsd/sys/kpi_socket.h

   1 /*
   2  * Copyright (c) 2004 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28 /*!
  29         @header kpi_socket.h
  30         This header defines an API for creating and interacting with sockets
  31         in the kernel. It is possible to create sockets in the kernel
  32         without an associated file descriptor. In some cases, a reference to
  33         the socket may be known while the file descriptor is not. These
  34         functions can be used for interacting with sockets in the kernel.
  35         The API is similar to the user space socket API.
  36  */
  37 #ifndef __KPI_SOCKET__
  38 #define __KPI_SOCKET__
  39
  40 #include <sys/types.h>
  41 #include <sys/kernel_types.h>
  42
  43 struct timeval;
  44
  45 /*!
  46         @typedef sock_upcall
  47
  48         @discussion sock_upcall is used by a socket to notify an in kernel
  49                 client that data is waiting. Instead of making blocking calls in
  50                 the kernel, a client can specify an upcall which will be called
  51                 when data is available or the socket is ready for sending.
  52
  53                 Calls to your upcall function are not serialized and may be
  54                 called concurrently from multiple threads in the kernel.
  55
  56                 Your upcall function will be called when:
  57
  58         @param so A reference to the socket that's ready.
  59         @param cookie The cookie passed in when the socket was created.
  60         @param waitf Indicates whether or not it's safe to block.
  61 */
  62 typedef void (*sock_upcall)(socket_t so, void* cookie, int waitf);
  63
  64 /*!
  65         @function sock_accept
  66         @discussion Accepts an incoming connection on a socket. See 'man 2
  67                 accept' for more information. Allocating a socket in this manner
  68                 creates a socket with no associated file descriptor.
  69         @param so The listening socket you'd like to accept a connection on.
  70         @param from A pointer to a socket address that will be filled in
  71                 with the address the connection is from.
  72         @param fromlen Maximum length of from.
  73         @param flags Supports MSG_DONTWAIT and MSG_USEUPCALL. If
  74                 MSG_DONTWAIT is set, accept will return EWOULDBLOCK if there are
  75                 no connections ready to be accepted. If MSG_USEUPCALL is set,
  76                 the created socket will use the same upcall function attached to
  77                 the original socket.
  78         @param callback A notifier function to be called when an event
  79                 occurs on the socket. This may be NULL.
  80         @param cookie A cookie passed directly to the callback.
  81         @param new_so Upon success, *new_so will be a reference to a new
  82                 socket for tracking the connection.
  83         @result 0 on success otherwise the errno error.
  84  */
  85 errno_t sock_accept(socket_t so, struct sockaddr *from, int fromlen,
  86                                         int flags, sock_upcall callback, void* cookie,
  87                                         socket_t *new_so);
  88
  89 /*!
  90         @function sock_bind
  91         @discussion Binds a socket to a specific address. See 'man 2 bind'
  92                 for more information.
  93         @param so The socket to be bound.
  94         @param to The local address the socket should be bound to.
  95         @result 0 on success otherwise the errno error.
  96  */
  97 errno_t sock_bind(socket_t so, const struct sockaddr *to);
  98
  99 /*!
 100         @function sock_connect
 101         @discussion Initiates a connection on the socket. See 'man 2
 102                 connect' for more information.
 103         @param so The socket to be connect.
 104         @param to The remote address the socket should connect to.
 105         @param flags Flags for connecting. The only flag supported so far is
 106                 MSG_DONTWAIT. MSG_DONTWAIT will perform a non-blocking connect.
 107                 sock_connect will return immediately with EINPROGRESS. The
 108                 upcall, if supplied, will be called when the connection is
 109                 completed.
 110         @result 0 on success, EINPROGRESS for a non-blocking connect that
 111                 has not completed, otherwise the errno error.
 112  */
 113 errno_t sock_connect(socket_t so, const struct sockaddr *to, int flags);
 114
 115 #ifdef KERNEL_PRIVATE
 116 /*!
 117         This function was added to support NFS. NFS does something funny,
 118         setting a short timeout and checking to see if it should abort the
 119         connect every two seconds. Ideally, NFS would use the upcall to be
 120         notified when the connect is complete.
 121
 122         If you feel you need to use this function, please contact us to
 123         explain why.
 124
 125         @function sock_connectwait
 126         @discussion Allows a caller to wait on a socket connect.
 127         @param so The socket being connected.
 128         @param tv The amount of time to wait.
 129         @result 0 on success otherwise the errno error. EINPROGRESS will be
 130                 returned if the connection did not complete in the timeout
 131                 specified.
 132  */
 133 errno_t sock_connectwait(socket_t so, const struct timeval *tv);
 134 #endif KERNEL_PRIVATE
 135
 136 /*!
 137         @function sock_getpeername
 138         @discussion Retrieves the remote address of a connected socket. See
 139                 'man 2 getpeername'.
 140         @param so The socket.
 141         @param peername Storage for the peer name.
 142         @param peernamelen Length of storage for the peer name.
 143         @result 0 on success otherwise the errno error.
 144  */
 145 errno_t sock_getpeername(socket_t so, struct sockaddr *peername, int peernamelen);
 146
 147 /*!
 148         @function sock_getsockname
 149         @discussion Retrieves the local address of a socket. See 'man 2
 150                 getsockname'.
 151         @param so The socket.
 152         @param sockname Storage for the local name.
 153         @param socknamelen Length of storage for the socket name.
 154         @result 0 on success otherwise the errno error.
 155  */
 156 errno_t sock_getsockname(socket_t so, struct sockaddr *sockname, int socknamelen);
 157
 158 /*!
 159         @function sock_getsockopt
 160         @discussion Retrieves a socket option. See 'man 2 getsockopt'.
 161         @param so The socket.
 162         @param level Level of the socket option.
 163         @param optname The option name.
 164         @param optval The option value.
 165         @param optlen The length of optval, returns the actual length.
 166         @result 0 on success otherwise the errno error.
 167  */
 168 errno_t sock_getsockopt(socket_t so, int level, int optname, void *optval, int *optlen);
 169
 170 /*!
 171         @function sock_ioctl
 172         @discussion Performs an ioctl operation on a socket. See 'man 2 ioctl'.
 173         @param so The socket.
 174         @param request The ioctl name.
 175         @param argp The argument.
 176         @result 0 on success otherwise the errno error.
 177  */
 178 errno_t sock_ioctl(socket_t so, unsigned long request, void *argp);
 179
 180 /*!
 181         @function sock_setsockopt
 182         @discussion Sets a socket option. See 'man 2 setsockopt'.
 183         @param so The socket.
 184         @param level Level of the socket option.
 185         @param optname The option name.
 186         @param optval The option value.
 187         @param optlen The length of optval.
 188         @result 0 on success otherwise the errno error.
 189  */
 190 errno_t sock_setsockopt(socket_t so, int level, int optname, const void *optval, int optlen);
 191
 192 /*!
 193         @function sock_listen
 194         @discussion Indicate that the socket should start accepting incoming
 195                 connections. See 'man 2 listen'.
 196         @param so The socket.
 197         @param backlog The maximum length of the queue of pending connections.
 198         @result 0 on success otherwise the errno error.
 199  */
 200 errno_t sock_listen(socket_t so, int backlog);
 201
 202 /*!
 203         @function sock_receive
 204         @discussion Receive data from a socket. Similar to recvmsg. See 'man
 205                 2 recvmsg' for more information about receiving data.
 206         @param so The socket.
 207         @param msg The msg describing how the data should be received.
 208         @param flags See 'man 2 recvmsg'.
 209         @param recvdlen Number of bytes received, same as return value of
 210                 userland recvmsg.
 211         @result 0 on success, EWOULDBLOCK if non-blocking and operation
 212                 would cause the thread to block, otherwise the errno error.
 213  */
 214 errno_t sock_receive(socket_t so, struct msghdr *msg, int flags, size_t *recvdlen);
 215
 216 /*!
 217         @function sock_receivembuf
 218         @discussion Receive data from a socket. Similar to sock_receive
 219                 though data is returned as a chain of mbufs. See 'man 2 recvmsg'
 220                 for more information about receiving data.
 221         @param so The socket.
 222         @param msg The msg describing how the data should be received. May
 223                 be NULL. The msg_iov is ignored.
 224         @param data Upon return *data will be a reference to an mbuf chain
 225                 containing the data received. This eliminates copying the data
 226                 out of the mbufs. Caller is responsible for freeing the mbufs.
 227         @param flags See 'man 2 recvmsg'.
 228         @param recvlen Maximum number of bytes to receive in the mbuf chain.
 229                 Upon return, this value will be set to the number of bytes
 230                 received, same as return value of userland recvmsg.
 231         @result 0 on success, EWOULDBLOCK if non-blocking and operation
 232                 would cause the thread to block, otherwise the errno error.
 233  */
 234 errno_t sock_receivembuf(socket_t so, struct msghdr *msg, mbuf_t *data, int flags, size_t *recvlen);
 235
 236 /*!
 237         @function sock_send
 238         @discussion Send data on a socket. Similar to sendmsg. See 'man 2
 239                 sendmsg' for more information about sending data.
 240         @param so The socket.
 241         @param msg The msg describing how the data should be sent. Any
 242                 pointers must point to data in the kernel.
 243         @param flags See 'man 2 sendmsg'.
 244         @param sentlen The number of bytes sent.
 245         @result 0 on success, EWOULDBLOCK if non-blocking and operation
 246                 would cause the thread to block, otherwise the errno error.
 247  */
 248 errno_t sock_send(socket_t so, const struct msghdr *msg, int flags, size_t *sentlen);
 249
 250 /*!
 251         @function sock_sendmbuf
 252         @discussion Send data in an mbuf on a socket. Similar to sock_send
 253                 only the data to be sent is taken from the mbuf chain.
 254         @param so The socket.
 255         @param msg The msg describing how the data should be sent. The
 256                 msg_iov is ignored. msg may be NULL.
 257         @param data The mbuf chain of data to send.
 258         @param flags See 'man 2 sendmsg'.
 259         @param sentlen The number of bytes sent.
 260         @result 0 on success, EWOULDBLOCK if non-blocking and operation
 261                 would cause the thread to block, otherwise the errno error.
 262                 Regardless of return value, the mbuf chain 'data' will be freed.
 263  */
 264 errno_t sock_sendmbuf(socket_t so, const struct msghdr *msg, mbuf_t data, int flags, size_t *sentlen);
 265
 266 /*!
 267         @function sock_shutdown
 268         @discussion Shutdown one or both directions of a connection. See
 269                 'man 2 shutdown' for more information.
 270         @param so The socket.
 271         @param how SHUT_RD - shutdown receive. SHUT_WR - shutdown send. SHUT_RDWR - shutdown both.
 272         @result 0 on success otherwise the errno error.
 273  */
 274 errno_t sock_shutdown(socket_t so, int how);
 275
 276 /*!
 277         @function sock_socket
 278         @discussion Allocate a socket. Allocating a socket in this manner
 279                 creates a socket with no associated file descriptor. For more
 280                 information, see 'man 2 socket'.
 281         @param domain The socket domain (PF_INET, etc...).
 282         @param type The socket type (SOCK_STREAM, SOCK_DGRAM, etc...).
 283         @param protocol The socket protocol.
 284         @param callback A notifier function to be called when an event
 285                 occurs on the socket. This may be NULL.
 286         @param cookie A cookie passed directly to the callback.
 287         @param new_so Upon success, a reference to the new socket.
 288         @result 0 on success otherwise the errno error.
 289  */
 290 errno_t sock_socket(int domain, int type, int protocol, sock_upcall callback,
 291                            void* cookie, socket_t *new_so);
 292
 293 /*!
 294         @function sock_close
 295         @discussion Close the socket.
 296         @param so The socket to close. This should only ever be a socket
 297                 created with sock_socket. Closing a socket created in user space
 298                 using sock_close may leave a file descriptor pointing to the closed
 299                 socket, resulting in undefined behavior.
 300  */
 301 void    sock_close(socket_t so);
 302
 303 /*!
 304         @function sock_retain
 305         @discussion Prevents the socket from closing
 306         @param so The socket to close.  Increment a retain count on the
 307                 socket, preventing it from being closed when sock_close is
 308                 called. This is used when a File Descriptor is passed (and
 309                 closed) from userland and the kext wants to keep ownership of
 310                 that socket. It is used in conjunction with
 311                 sock_release(socket_t so).
 312  */
 313 void    sock_retain(socket_t so);
 314
 315 /*!
 316         @function sock_release
 317         @discussion Decrement the retain count and close the socket if the
 318                 retain count reaches zero.
 319         @param so The socket to release. This is used to release ownership
 320                 on a socket acquired with sock_retain. When the last retain
 321                 count is reached, this will call sock_close to close the socket.
 322  */
 323 void    sock_release(socket_t so);
 324
 325 /*!
 326         @function sock_setpriv
 327         @discussion Set the privileged bit in the socket. Allows for
 328                 operations that require root privileges.
 329         @param so The socket on which to modify the SS_PRIV flag.
 330         @param on Indicate whether or not the SS_PRIV flag should be set.
 331         @result 0 on success otherwise the errno error.
 332  */
 333 errno_t sock_setpriv(socket_t so, int on);
 334
 335 /*!
 336         @function sock_isconnected
 337         @discussion Returns whether or not the socket is connected.
 338         @param so The socket to check.
 339         @result 0 - socket is not connected. 1 - socket is connected.
 340  */
 341 int sock_isconnected(socket_t so);
 342
 343 /*!
 344         @function sock_isnonblocking
 345         @discussion Returns whether or not the socket is non-blocking. In
 346                 the context of this KPI, non-blocking means that functions to
 347                 perform operations on a socket will not wait for completion.
 348
 349                 To enable or disable blocking, use the FIONBIO ioctl. The
 350                 parameter is an int. If the int is zero, the socket will block.
 351                 If the parameter is non-zero, the socket will not block.
 352         @result 0 - socket will block. 1 - socket will not block.
 353  */
 354 int sock_isnonblocking(socket_t so);
 355
 356 /*!
 357         @function sock_gettype
 358         @discussion Retrieves information about the socket. This is the same
 359                 information that was used to create the socket. If any of the
 360                 parameters following so are NULL, that information is not
 361                 retrieved.
 362         @param so The socket to check.
 363         @param domain The domain of the socket (PF_INET, etc...). May be NULL.
 364         @param type The socket type (SOCK_STREAM, SOCK_DGRAM, etc...). May be NULL.
 365         @param protocol The socket protocol. May be NULL.
 366         @result 0 on success otherwise the errno error.
 367  */
 368 errno_t sock_gettype(socket_t so, int *domain, int *type, int *protocol);
 369
 370 #ifdef KERNEL_PRIVATE
 371 /*!
 372         @function sock_nointerrupt
 373         @discussion Disables interrupt on socket buffers (sets SB_NOINTR on
 374                 send and receive socket buffers).
 375         @param so The socket to modify.
 376         @param on Indicate whether or not the SB_NOINTR flag should be set.
 377         @result 0 on success otherwise the errno error.
 378  */
 379 errno_t sock_nointerrupt(socket_t so, int on);
 380 #endif KERNEL_PRIVATE
 381 #endif __KPI_SOCKET__