bsd/sys/kpi_socket.h

   1 /*
   2  * Copyright (c) 2008 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 #include <sys/socket.h>
  43
  44 __BEGIN_DECLS
  45
  46 struct timeval;
  47
  48 /*!
  49         @typedef sock_upcall
  50
  51         @discussion sock_upcall is used by a socket to notify an in kernel
  52                 client that data is waiting. Instead of making blocking calls in
  53                 the kernel, a client can specify an upcall which will be called
  54                 when data is available or the socket is ready for sending.
  55
  56                 Calls to your upcall function are not serialized and may be
  57                 called concurrently from multiple threads in the kernel.
  58
  59                 Your upcall function will be called when:
  60
  61         @param so A reference to the socket that's ready.
  62         @param cookie The cookie passed in when the socket was created.
  63         @param waitf Indicates whether or not it's safe to block.
  64 */
  65 typedef void (*sock_upcall)(socket_t so, void *cookie, int waitf);
  66
  67 /*!
  68         @function sock_accept
  69         @discussion Accepts an incoming connection on a socket. See 'man 2
  70                 accept' for more information. Allocating a socket in this manner
  71                 creates a socket with no associated file descriptor.
  72         @param so The listening socket you'd like to accept a connection on.
  73         @param from A pointer to a socket address that will be filled in
  74                 with the address the connection is from.
  75         @param fromlen Maximum length of from.
  76         @param flags Supports MSG_DONTWAIT and MSG_USEUPCALL. If
  77                 MSG_DONTWAIT is set, accept will return EWOULDBLOCK if there are
  78                 no connections ready to be accepted. If MSG_USEUPCALL is set,
  79                 the created socket will use the same upcall function attached to
  80                 the original socket.
  81         @param callback A notifier function to be called when an event
  82                 occurs on the socket. This may be NULL.
  83         @param cookie A cookie passed directly to the callback.
  84         @param new_so Upon success, *new_so will be a reference to a new
  85                 socket for tracking the connection.
  86         @result 0 on success otherwise the errno error.
  87  */
  88 extern errno_t sock_accept(socket_t so, struct sockaddr *from, int fromlen,
  89     int flags, sock_upcall callback, void *cookie, socket_t *new_so);
  90
  91 /*!
  92         @function sock_bind
  93         @discussion Binds a socket to a specific address. See 'man 2 bind'
  94                 for more information.
  95         @param so The socket to be bound.
  96         @param to The local address the socket should be bound to.
  97         @result 0 on success otherwise the errno error.
  98  */
  99 extern errno_t sock_bind(socket_t so, const struct sockaddr *to);
 100
 101 /*!
 102         @function sock_connect
 103         @discussion Initiates a connection on the socket. See 'man 2
 104                 connect' for more information.
 105         @param so The socket to be connect.
 106         @param to The remote address the socket should connect to.
 107         @param flags Flags for connecting. The only flag supported so far is
 108                 MSG_DONTWAIT. MSG_DONTWAIT will perform a non-blocking connect.
 109                 sock_connect will return immediately with EINPROGRESS. The
 110                 upcall, if supplied, will be called when the connection is
 111                 completed.
 112         @result 0 on success, EINPROGRESS for a non-blocking connect that
 113                 has not completed, otherwise the errno error.
 114  */
 115 extern errno_t sock_connect(socket_t so, const struct sockaddr *to, int flags);
 116
 117 #ifdef KERNEL_PRIVATE
 118 /*
 119         This function was added to support NFS. NFS does something funny,
 120         setting a short timeout and checking to see if it should abort the
 121         connect every two seconds. Ideally, NFS would use the upcall to be
 122         notified when the connect is complete.
 123
 124         If you feel you need to use this function, please contact us to
 125         explain why.
 126
 127         @function sock_connectwait
 128         @discussion Allows a caller to wait on a socket connect.
 129         @param so The socket being connected.
 130         @param tv The amount of time to wait.
 131         @result 0 on success otherwise the errno error. EINPROGRESS will be
 132                 returned if the connection did not complete in the timeout
 133                 specified.
 134  */
 135 extern errno_t sock_connectwait(socket_t so, const struct timeval *tv);
 136 #endif /* KERNEL_PRIVATE */
 137
 138 /*!
 139         @function sock_getpeername
 140         @discussion Retrieves the remote address of a connected socket. See
 141                 'man 2 getpeername'.
 142         @param so The socket.
 143         @param peername Storage for the peer name.
 144         @param peernamelen Length of storage for the peer name.
 145         @result 0 on success otherwise the errno error.
 146  */
 147 extern errno_t sock_getpeername(socket_t so, struct sockaddr *peername,
 148     int peernamelen);
 149
 150 /*!
 151         @function sock_getsockname
 152         @discussion Retrieves the local address of a socket. See 'man 2
 153                 getsockname'.
 154         @param so The socket.
 155         @param sockname Storage for the local name.
 156         @param socknamelen Length of storage for the socket name.
 157         @result 0 on success otherwise the errno error.
 158  */
 159 extern errno_t sock_getsockname(socket_t so, struct sockaddr *sockname,
 160     int socknamelen);
 161
 162 /*!
 163         @function sock_getsockopt
 164         @discussion Retrieves a socket option. See 'man 2 getsockopt'.
 165         @param so The socket.
 166         @param level Level of the socket option.
 167         @param optname The option name.
 168         @param optval The option value.
 169         @param optlen The length of optval, returns the actual length.
 170         @result 0 on success otherwise the errno error.
 171  */
 172 extern errno_t sock_getsockopt(socket_t so, int level, int optname,
 173     void *optval, int *optlen);
 174
 175 /*!
 176         @function sock_ioctl
 177         @discussion Performs an ioctl operation on a socket. See 'man 2 ioctl'.
 178         @param so The socket.
 179         @param request The ioctl name.
 180         @param argp The argument.
 181         @result 0 on success otherwise the errno error.
 182  */
 183 extern errno_t sock_ioctl(socket_t so, unsigned long request, void *argp);
 184
 185 /*!
 186         @function sock_setsockopt
 187         @discussion Sets a socket option. See 'man 2 setsockopt'.
 188         @param so The socket.
 189         @param level Level of the socket option.
 190         @param optname The option name.
 191         @param optval The option value.
 192         @param optlen The length of optval.
 193         @result 0 on success otherwise the errno error.
 194  */
 195 extern errno_t sock_setsockopt(socket_t so, int level, int optname,
 196     const void *optval, int optlen);
 197
 198 #ifdef KERNEL_PRIVATE
 199 /*
 200         This function was added to support AFP setting the traffic class
 201         for a backup stream within a wireless LAN or over link-local address.
 202
 203         If you feel you need to use this function, please contact us to
 204         explain why.
 205
 206         @function sock_settclassopt
 207         @discussion Allows a caller to set the traffic class.
 208         @param so The socket.
 209         @param optval The option value.
 210         @param optlen The length of optval.
 211         @result 0 on success otherwise the errno error.
 212  */
 213 extern errno_t sock_settclassopt(socket_t so, const void* optval, size_t optlen);
 214
 215 /*
 216         This function was added to support AFP getting the traffic class
 217         set on a stream.
 218
 219         This is also a private API, please contact us if you need to use it.
 220
 221         @function sockgettclassopt
 222         @discussion Allows a caller to get the traffic class.
 223         @param so The socket.
 224         @param optval The option value.
 225         @param optlen The length of optval, returns the actual length.
 226         @result 0 on success otherwise the errno error.
 227 */
 228 extern errno_t sock_gettclassopt(socket_t so, void* optval, size_t* optlen);
 229 #endif
 230
 231 /*!
 232         @function sock_listen
 233         @discussion Indicate that the socket should start accepting incoming
 234                 connections. See 'man 2 listen'.
 235         @param so The socket.
 236         @param backlog The maximum length of the queue of pending connections.
 237         @result 0 on success otherwise the errno error.
 238  */
 239 extern errno_t sock_listen(socket_t so, int backlog);
 240
 241 /*!
 242         @function sock_receive
 243         @discussion Receive data from a socket. Similar to recvmsg. See 'man
 244                 2 recvmsg' for more information about receiving data.
 245         @param so The socket.
 246         @param msg The msg describing how the data should be received.
 247         @param flags See 'man 2 recvmsg'.
 248         @param recvdlen Number of bytes received, same as return value of
 249                 userland recvmsg.
 250         @result 0 on success, EWOULDBLOCK if non-blocking and operation
 251                 would cause the thread to block, otherwise the errno error.
 252  */
 253 extern errno_t sock_receive(socket_t so, struct msghdr *msg, int flags,
 254     size_t *recvdlen);
 255
 256 /*!
 257         @function sock_receivembuf
 258         @discussion Receive data from a socket. Similar to sock_receive
 259                 though data is returned as a chain of mbufs. See 'man 2 recvmsg'
 260                 for more information about receiving data.
 261         @param so The socket.
 262         @param msg The msg describing how the data should be received. May
 263                 be NULL. The msg_iov is ignored.
 264         @param data Upon return *data will be a reference to an mbuf chain
 265                 containing the data received. This eliminates copying the data
 266                 out of the mbufs. Caller is responsible for freeing the mbufs.
 267         @param flags See 'man 2 recvmsg'.
 268         @param recvlen Maximum number of bytes to receive in the mbuf chain.
 269                 Upon return, this value will be set to the number of bytes
 270                 received, same as return value of userland recvmsg.
 271         @result 0 on success, EWOULDBLOCK if non-blocking and operation
 272                 would cause the thread to block, otherwise the errno error.
 273  */
 274 extern errno_t sock_receivembuf(socket_t so, struct msghdr *msg, mbuf_t *data,
 275     int flags, size_t *recvlen);
 276
 277 /*!
 278         @function sock_send
 279         @discussion Send data on a socket. Similar to sendmsg. See 'man 2
 280                 sendmsg' for more information about sending data.
 281         @param so The socket.
 282         @param msg The msg describing how the data should be sent. Any
 283                 pointers must point to data in the kernel.
 284         @param flags See 'man 2 sendmsg'.
 285         @param sentlen The number of bytes sent.
 286         @result 0 on success, EWOULDBLOCK if non-blocking and operation
 287                 would cause the thread to block, otherwise the errno error.
 288  */
 289 extern errno_t sock_send(socket_t so, const struct msghdr *msg, int flags,
 290     size_t *sentlen);
 291
 292 /*!
 293         @function sock_sendmbuf
 294         @discussion Send data in an mbuf on a socket. Similar to sock_send
 295                 only the data to be sent is taken from the mbuf chain.
 296         @param so The socket.
 297         @param msg The msg describing how the data should be sent. The
 298                 msg_iov is ignored. msg may be NULL.
 299         @param data The mbuf chain of data to send.
 300         @param flags See 'man 2 sendmsg'.
 301         @param sentlen The number of bytes sent.
 302         @result 0 on success, EWOULDBLOCK if non-blocking and operation
 303                 would cause the thread to block, otherwise the errno error.
 304                 Regardless of return value, the mbuf chain 'data' will be freed.
 305  */
 306 extern errno_t sock_sendmbuf(socket_t so, const struct msghdr *msg, mbuf_t data,
 307     int flags, size_t *sentlen);
 308
 309 /*!
 310         @function sock_shutdown
 311         @discussion Shutdown one or both directions of a connection. See
 312                 'man 2 shutdown' for more information.
 313         @param so The socket.
 314         @param how SHUT_RD - shutdown receive.
 315                 SHUT_WR - shutdown send.
 316                 SHUT_RDWR - shutdown both.
 317         @result 0 on success otherwise the errno error.
 318  */
 319 extern errno_t sock_shutdown(socket_t so, int how);
 320
 321 /*!
 322         @function sock_socket
 323         @discussion Allocate a socket. Allocating a socket in this manner
 324                 creates a socket with no associated file descriptor. For more
 325                 information, see 'man 2 socket'.
 326         @param domain The socket domain (PF_INET, etc...).
 327         @param type The socket type (SOCK_STREAM, SOCK_DGRAM, etc...).
 328         @param protocol The socket protocol.
 329         @param callback A notifier function to be called when an event
 330                 occurs on the socket. This may be NULL.
 331         @param cookie A cookie passed directly to the callback.
 332         @param new_so Upon success, a reference to the new socket.
 333         @result 0 on success otherwise the errno error.
 334  */
 335 extern errno_t sock_socket(int domain, int type, int protocol,
 336     sock_upcall callback, void *cookie, socket_t *new_so);
 337
 338 /*!
 339         @function sock_close
 340         @discussion Close the socket.
 341         @param so The socket to close. This should only ever be a socket
 342                 created with sock_socket. Closing a socket created in user space
 343                 using sock_close may leave a file descriptor pointing to the
 344                 closed socket, resulting in undefined behavior.
 345  */
 346 extern void sock_close(socket_t so);
 347
 348 #ifdef KERNEL_PRIVATE
 349 /*
 350         @function sock_retain
 351         @discussion Prevents the socket from closing
 352         @param so The socket to close.  Increment a retain count on the
 353                 socket, preventing it from being closed when sock_close is
 354                 called. This is used when a File Descriptor is passed (and
 355                 closed) from userland and the kext wants to keep ownership of
 356                 that socket. It is used in conjunction with
 357                 sock_release(socket_t so).
 358  */
 359 extern void sock_retain(socket_t so);
 360
 361 /*
 362         @function sock_release
 363         @discussion Decrement the retain count and close the socket if the
 364                 retain count reaches zero.
 365         @param so The socket to release. This is used to release ownership
 366                 on a socket acquired with sock_retain. When the last retain
 367                 count is reached, this will call sock_close to close the socket.
 368  */
 369 extern void sock_release(socket_t so);
 370 #endif /* KERNEL_PRIVATE */
 371
 372 /*!
 373         @function sock_setpriv
 374         @discussion Set the privileged bit in the socket. Allows for
 375                 operations that require root privileges.
 376         @param so The socket on which to modify the SS_PRIV flag.
 377         @param on Indicate whether or not the SS_PRIV flag should be set.
 378         @result 0 on success otherwise the errno error.
 379  */
 380 extern errno_t sock_setpriv(socket_t so, int on);
 381
 382 /*!
 383         @function sock_isconnected
 384         @discussion Returns whether or not the socket is connected.
 385         @param so The socket to check.
 386         @result 0 - socket is not connected. 1 - socket is connected.
 387  */
 388 extern int sock_isconnected(socket_t so);
 389
 390 /*!
 391         @function sock_isnonblocking
 392         @discussion Returns whether or not the socket is non-blocking. In
 393                 the context of this KPI, non-blocking means that functions to
 394                 perform operations on a socket will not wait for completion.
 395
 396                 To enable or disable blocking, use the FIONBIO ioctl. The
 397                 parameter is an int. If the int is zero, the socket will block.
 398                 If the parameter is non-zero, the socket will not block.
 399         @result 0 - socket will block. 1 - socket will not block.
 400  */
 401 extern int sock_isnonblocking(socket_t so);
 402
 403 /*!
 404         @function sock_gettype
 405         @discussion Retrieves information about the socket. This is the same
 406                 information that was used to create the socket. If any of the
 407                 parameters following so are NULL, that information is not
 408                 retrieved.
 409         @param so The socket to check.
 410         @param domain The domain of the socket (PF_INET, ...). May be NULL.
 411         @param type The socket type (SOCK_STREAM, SOCK_DGRAM, ...). May be NULL.
 412         @param protocol The socket protocol. May be NULL.
 413         @result 0 on success otherwise the errno error.
 414  */
 415 extern errno_t sock_gettype(socket_t so, int *domain, int *type, int *protocol);
 416
 417 #ifdef KERNEL_PRIVATE
 418 /*
 419         @function sock_nointerrupt
 420         @discussion Disables interrupt on socket buffers (sets SB_NOINTR on
 421                 send and receive socket buffers).
 422         @param so The socket to modify.
 423         @param on Indicate whether or not the SB_NOINTR flag should be set.
 424         @result 0 on success otherwise the errno error.
 425  */
 426 extern errno_t sock_nointerrupt(socket_t so, int on);
 427
 428 /*
 429         @function sock_getlistener
 430         @discussion Retrieves the listening socket of a pre-accepted socket,
 431                 i.e. a socket which is still in the incomplete/completed list.
 432                 Once a socket has been accepted, the information pertaining
 433                 to its listener is no longer available.  Therefore, modules
 434                 interested in finding out the listening socket should install
 435                 the appropriate socket filter callback (sf_attach) which gets
 436                 invoked prior to the socket being fully accepted, and call
 437                 this routine at such a time to obtain the listener.  Callers
 438                 are guaranteed that the listener socket will not go away
 439                 during the sf_attach callback, and therefore the value is
 440                 safe to be used only in that callback context.  Callers should
 441                 therefore take note that the listening socket's lock will be
 442                 held throughout the duration of the callback.
 443         @param so The pre-accepted socket.
 444         @result Non-NULL value which indicates the listening socket; otherwise,
 445                 NULL if the socket is not in the incomplete/completed list
 446                 of a listener.
 447  */
 448 extern socket_t sock_getlistener(socket_t so);
 449
 450 /*
 451         @function sock_getaddr
 452         @discussion Retrieves the local or remote address of a socket.
 453                 This is a composite of sock_getpeername and sock_getsockname,
 454                 except that the allocated socket address is returned to the
 455                 caller, and that the caller is reponsible for calling
 456                 sock_freeaddr once finished with it.
 457         @param so The socket.
 458         @param psockname Pointer to the storage for the socket name.
 459         @param peername 0 for local address, and non-zero for peer address.
 460         @result 0 on success otherwise the errno error.
 461  */
 462 extern errno_t sock_getaddr(socket_t so, struct sockaddr **psockname,
 463     int peername);
 464
 465 /*
 466         @function sock_freeaddr
 467         @discussion Frees the socket address allocated by sock_getaddr.
 468         @param sockname The socket name to be freed.
 469  */
 470 extern void sock_freeaddr(struct sockaddr *sockname);
 471 #endif /* KERNEL_PRIVATE */
 472
 473 __END_DECLS
 474 #endif /* __KPI_SOCKET__ */