1/*
2 * Copyright (c) 2008-2012 Apple 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
46struct 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:
60		    when there is data more than the low water mark for reading,
61		    or when there is space for a write,
62		    or when there is a connection to accept,
63		    or when a socket is connected,
64		    or when a socket is closed or disconnected
65
66	@param so A reference to the socket that's ready.
67	@param cookie The cookie passed in when the socket was created.
68	@param waitf Indicates whether or not it's safe to block.
69*/
70typedef void (*sock_upcall)(socket_t so, void *cookie, int waitf);
71
72#ifdef KERNEL_PRIVATE
73/*!
74	@typedef sock_evupcall
75
76	@discussion sock_evupcall is used by a socket to notify an in kernel
77		client when an event occurs. Instead of making blocking calls in
78		the kernel, a client can specify an upcall which will be called
79		when an event status is available.
80	@param so A reference to the socket that's ready.
81	@param cookie The cookie passed in when the socket was created.
82	@param int Indicates the event as defined by SO_FILT_HINT_*
83*/
84typedef void (*sock_evupcall)(socket_t so, void *cookie, u_int32_t event);
85#endif /* KERNEL_PRIVATE */
86
87/*!
88	@function sock_accept
89	@discussion Accepts an incoming connection on a socket. See 'man 2
90		accept' for more information. Allocating a socket in this manner
91		creates a socket with no associated file descriptor.
92	@param so The listening socket you'd like to accept a connection on.
93	@param from A pointer to a socket address that will be filled in
94		with the address the connection is from.
95	@param fromlen Maximum length of from.
96	@param flags Supports MSG_DONTWAIT and MSG_USEUPCALL. If
97		MSG_DONTWAIT is set, accept will return EWOULDBLOCK if there are
98		no connections ready to be accepted. If MSG_USEUPCALL is set,
99		the created socket will use the same upcall function attached to
100		the original socket.
101	@param callback A notifier function to be called when an event
102		occurs on the socket. This may be NULL.
103	@param cookie A cookie passed directly to the callback.
104	@param new_so Upon success, *new_so will be a reference to a new
105		socket for tracking the connection.
106	@result 0 on success otherwise the errno error.
107 */
108extern errno_t sock_accept(socket_t so, struct sockaddr *from, int fromlen,
109    int flags, sock_upcall callback, void *cookie, socket_t *new_so);
110
111/*!
112	@function sock_bind
113	@discussion Binds a socket to a specific address. See 'man 2 bind'
114		for more information.
115	@param so The socket to be bound.
116	@param to The local address the socket should be bound to.
117	@result 0 on success otherwise the errno error.
118 */
119extern errno_t sock_bind(socket_t so, const struct sockaddr *to);
120
121/*!
122	@function sock_connect
123	@discussion Initiates a connection on the socket. See 'man 2
124		connect' for more information.
125	@param so The socket to be connect.
126	@param to The remote address the socket should connect to.
127	@param flags Flags for connecting. The only flag supported so far is
128		MSG_DONTWAIT. MSG_DONTWAIT will perform a non-blocking connect.
129		sock_connect will return immediately with EINPROGRESS. The
130		upcall, if supplied, will be called when the connection is
131		completed.
132	@result 0 on success, EINPROGRESS for a non-blocking connect that
133		has not completed, otherwise the errno error.
134 */
135extern errno_t sock_connect(socket_t so, const struct sockaddr *to, int flags);
136
137#ifdef KERNEL_PRIVATE
138/*
139	This function was added to support NFS. NFS does something funny,
140	setting a short timeout and checking to see if it should abort the
141	connect every two seconds. Ideally, NFS would use the upcall to be
142	notified when the connect is complete.
143
144	If you feel you need to use this function, please contact us to
145	explain why.
146
147	@function sock_connectwait
148	@discussion Allows a caller to wait on a socket connect.
149	@param so The socket being connected.
150	@param tv The amount of time to wait.
151	@result 0 on success otherwise the errno error. EINPROGRESS will be
152		returned if the connection did not complete in the timeout
153		specified.
154 */
155extern errno_t sock_connectwait(socket_t so, const struct timeval *tv);
156#endif /* KERNEL_PRIVATE */
157
158/*!
159	@function sock_getpeername
160	@discussion Retrieves the remote address of a connected socket. See
161		'man 2 getpeername'.
162	@param so The socket.
163	@param peername Storage for the peer name.
164	@param peernamelen Length of storage for the peer name.
165	@result 0 on success otherwise the errno error.
166 */
167extern errno_t sock_getpeername(socket_t so, struct sockaddr *peername,
168    int peernamelen);
169
170/*!
171	@function sock_getsockname
172	@discussion Retrieves the local address of a socket. See 'man 2
173		getsockname'.
174	@param so The socket.
175	@param sockname Storage for the local name.
176	@param socknamelen Length of storage for the socket name.
177	@result 0 on success otherwise the errno error.
178 */
179extern errno_t sock_getsockname(socket_t so, struct sockaddr *sockname,
180    int socknamelen);
181
182/*!
183	@function sock_getsockopt
184	@discussion Retrieves a socket option. See 'man 2 getsockopt'.
185	@param so The socket.
186	@param level Level of the socket option.
187	@param optname The option name.
188	@param optval The option value.
189	@param optlen The length of optval, returns the actual length.
190	@result 0 on success otherwise the errno error.
191 */
192extern errno_t sock_getsockopt(socket_t so, int level, int optname,
193    void *optval, int *optlen);
194
195/*!
196	@function sock_ioctl
197	@discussion Performs an ioctl operation on a socket. See 'man 2 ioctl'.
198	@param so The socket.
199	@param request The ioctl name.
200	@param argp The argument.
201	@result 0 on success otherwise the errno error.
202 */
203extern errno_t sock_ioctl(socket_t so, unsigned long request, void *argp);
204
205/*!
206	@function sock_setsockopt
207	@discussion Sets a socket option. See 'man 2 setsockopt'.
208	@param so The socket.
209	@param level Level of the socket option.
210	@param optname The option name.
211	@param optval The option value.
212	@param optlen The length of optval.
213	@result 0 on success otherwise the errno error.
214 */
215extern errno_t sock_setsockopt(socket_t so, int level, int optname,
216    const void *optval, int optlen);
217
218#ifdef KERNEL_PRIVATE
219/*
220	This function was added to support AFP setting the traffic class
221	for a backup stream within a wireless LAN or over link-local address.
222
223	If you feel you need to use this function, please contact us to
224	explain why.
225
226	@function sock_settclassopt
227	@discussion Allows a caller to set the traffic class.
228	@param so The socket.
229	@param optval The option value.
230	@param optlen The length of optval.
231	@result 0 on success otherwise the errno error.
232 */
233extern errno_t sock_settclassopt(socket_t so, const void* optval, size_t optlen);
234
235/*
236	This function was added to support AFP getting the traffic class
237	set on a stream.
238
239	This is also a private API, please contact us if you need to use it.
240
241	@function sockgettclassopt
242	@discussion Allows a caller to get the traffic class.
243	@param so The socket.
244	@param optval The option value.
245	@param optlen The length of optval, returns the actual length.
246	@result 0 on success otherwise the errno error.
247*/
248extern errno_t sock_gettclassopt(socket_t so, void* optval, size_t* optlen);
249
250#ifdef XNU_KERNEL_PRIVATE
251extern void socket_set_traffic_mgt_flags_locked(socket_t so, u_int32_t flags);
252extern void socket_clear_traffic_mgt_flags_locked(socket_t so, u_int32_t flags);
253#endif /* XNU_KERNEL_PRIVATE */
254#ifdef BSD_KERNEL_PRIVATE
255extern void socket_set_traffic_mgt_flags(socket_t so, u_int32_t flags);
256extern void socket_clear_traffic_mgt_flags(socket_t so, u_int32_t flags);
257extern errno_t socket_defunct(struct proc *, socket_t so, int);
258extern errno_t sock_receive_internal(socket_t, struct msghdr *, mbuf_t *,
259    int, size_t *);
260#endif /* BSD_KERNEL_PRIVATE */
261#endif /* KERNEL_PRIVATE */
262
263/*!
264	@function sock_listen
265	@discussion Indicate that the socket should start accepting incoming
266		connections. See 'man 2 listen'.
267	@param so The socket.
268	@param backlog The maximum length of the queue of pending connections.
269	@result 0 on success otherwise the errno error.
270 */
271extern errno_t sock_listen(socket_t so, int backlog);
272
273/*!
274	@function sock_receive
275	@discussion Receive data from a socket. Similar to recvmsg. See 'man
276		2 recvmsg' for more information about receiving data.
277	@param so The socket.
278	@param msg The msg describing how the data should be received.
279	@param flags See 'man 2 recvmsg'.
280	@param recvdlen Number of bytes received, same as return value of
281		userland recvmsg.
282	@result 0 on success, EWOULDBLOCK if non-blocking and operation
283		would cause the thread to block, otherwise the errno error.
284 */
285extern errno_t sock_receive(socket_t so, struct msghdr *msg, int flags,
286    size_t *recvdlen);
287
288/*!
289	@function sock_receivembuf
290	@discussion Receive data from a socket. Similar to sock_receive
291		though data is returned as a chain of mbufs. See 'man 2 recvmsg'
292		for more information about receiving data.
293	@param so The socket.
294	@param msg The msg describing how the data should be received. May
295		be NULL. The msg_iov is ignored.
296	@param data Upon return *data will be a reference to an mbuf chain
297		containing the data received. This eliminates copying the data
298		out of the mbufs. Caller is responsible for freeing the mbufs.
299	@param flags See 'man 2 recvmsg'.
300	@param recvlen Maximum number of bytes to receive in the mbuf chain.
301		Upon return, this value will be set to the number of bytes
302		received, same as return value of userland recvmsg.
303	@result 0 on success, EWOULDBLOCK if non-blocking and operation
304		would cause the thread to block, otherwise the errno error.
305 */
306extern errno_t sock_receivembuf(socket_t so, struct msghdr *msg, mbuf_t *data,
307    int flags, size_t *recvlen);
308
309/*!
310	@function sock_send
311	@discussion Send data on a socket. Similar to sendmsg. See 'man 2
312		sendmsg' for more information about sending data.
313	@param so The socket.
314	@param msg The msg describing how the data should be sent. Any
315		pointers must point to data in the kernel.
316	@param flags See 'man 2 sendmsg'.
317	@param sentlen The number of bytes sent.
318	@result 0 on success, EWOULDBLOCK if non-blocking and operation
319		would cause the thread to block, otherwise the errno error.
320 */
321extern errno_t sock_send(socket_t so, const struct msghdr *msg, int flags,
322    size_t *sentlen);
323
324/*!
325	@function sock_sendmbuf
326	@discussion Send data in an mbuf on a socket. Similar to sock_send
327		only the data to be sent is taken from the mbuf chain.
328	@param so The socket.
329	@param msg The msg describing how the data should be sent. The
330		msg_iov is ignored. msg may be NULL.
331	@param data The mbuf chain of data to send.
332	@param flags See 'man 2 sendmsg'.
333	@param sentlen The number of bytes sent.
334	@result 0 on success, EWOULDBLOCK if non-blocking and operation
335		would cause the thread to block, otherwise the errno error.
336		Regardless of return value, the mbuf chain 'data' will be freed.
337 */
338extern errno_t sock_sendmbuf(socket_t so, const struct msghdr *msg, mbuf_t data,
339    int flags, size_t *sentlen);
340
341/*!
342	@function sock_shutdown
343	@discussion Shutdown one or both directions of a connection. See
344		'man 2 shutdown' for more information.
345	@param so The socket.
346	@param how SHUT_RD - shutdown receive.
347		SHUT_WR - shutdown send.
348		SHUT_RDWR - shutdown both.
349	@result 0 on success otherwise the errno error.
350 */
351extern errno_t sock_shutdown(socket_t so, int how);
352
353/*!
354	@function sock_socket
355	@discussion Allocate a socket. Allocating a socket in this manner
356		creates a socket with no associated file descriptor. For more
357		information, see 'man 2 socket'.
358	@param domain The socket domain (PF_INET, etc...).
359	@param type The socket type (SOCK_STREAM, SOCK_DGRAM, etc...).
360	@param protocol The socket protocol.
361	@param callback A notifier function to be called when an event
362		occurs on the socket. This may be NULL.
363	@param cookie A cookie passed directly to the callback.
364	@param new_so Upon success, a reference to the new socket.
365	@result 0 on success otherwise the errno error.
366 */
367extern errno_t sock_socket(int domain, int type, int protocol,
368    sock_upcall callback, void *cookie, socket_t *new_so);
369
370/*!
371	@function sock_close
372	@discussion Close the socket.
373	@param so The socket to close. This should only ever be a socket
374		created with sock_socket. Closing a socket created in user space
375		using sock_close may leave a file descriptor pointing to the
376		closed socket, resulting in undefined behavior.
377 */
378extern void sock_close(socket_t so);
379
380#ifdef KERNEL_PRIVATE
381/*
382	@function sock_retain
383	@discussion Prevents the socket from closing
384	@param so The socket to close.  Increment a retain count on the
385		socket, preventing it from being closed when sock_close is
386		called. This is used when a File Descriptor is passed (and
387		closed) from userland and the kext wants to keep ownership of
388		that socket. It is used in conjunction with
389		sock_release(socket_t so).
390 */
391extern void sock_retain(socket_t so);
392
393/*
394	@function sock_release
395	@discussion Decrement the retain count and close the socket if the
396		retain count reaches zero.
397	@param so The socket to release. This is used to release ownership
398		on a socket acquired with sock_retain. When the last retain
399		count is reached, this will call sock_close to close the socket.
400 */
401extern void sock_release(socket_t so);
402#endif /* KERNEL_PRIVATE */
403
404/*!
405	@function sock_setpriv
406	@discussion Set the privileged bit in the socket. Allows for
407		operations that require root privileges.
408	@param so The socket on which to modify the SS_PRIV flag.
409	@param on Indicate whether or not the SS_PRIV flag should be set.
410	@result 0 on success otherwise the errno error.
411 */
412extern errno_t sock_setpriv(socket_t so, int on);
413
414/*!
415	@function sock_isconnected
416	@discussion Returns whether or not the socket is connected.
417	@param so The socket to check.
418	@result 0 - socket is not connected. 1 - socket is connected.
419 */
420extern int sock_isconnected(socket_t so);
421
422/*!
423	@function sock_isnonblocking
424	@discussion Returns whether or not the socket is non-blocking. In
425		the context of this KPI, non-blocking means that functions to
426		perform operations on a socket will not wait for completion.
427
428		To enable or disable blocking, use the FIONBIO ioctl. The
429		parameter is an int. If the int is zero, the socket will block.
430		If the parameter is non-zero, the socket will not block.
431	@result 0 - socket will block. 1 - socket will not block.
432 */
433extern int sock_isnonblocking(socket_t so);
434
435/*!
436	@function sock_gettype
437	@discussion Retrieves information about the socket. This is the same
438		information that was used to create the socket. If any of the
439		parameters following so are NULL, that information is not
440		retrieved.
441	@param so The socket to check.
442	@param domain The domain of the socket (PF_INET, ...). May be NULL.
443	@param type The socket type (SOCK_STREAM, SOCK_DGRAM, ...). May be NULL.
444	@param protocol The socket protocol. May be NULL.
445	@result 0 on success otherwise the errno error.
446 */
447extern errno_t sock_gettype(socket_t so, int *domain, int *type, int *protocol);
448
449#ifdef KERNEL_PRIVATE
450/*
451	@function sock_nointerrupt
452	@discussion Disables interrupt on socket buffers (sets SB_NOINTR on
453		send and receive socket buffers).
454	@param so The socket to modify.
455	@param on Indicate whether or not the SB_NOINTR flag should be set.
456	@result 0 on success otherwise the errno error.
457 */
458extern errno_t sock_nointerrupt(socket_t so, int on);
459
460/*
461	@function sock_getlistener
462	@discussion Retrieves the listening socket of a pre-accepted socket,
463		i.e. a socket which is still in the incomplete/completed list.
464		Once a socket has been accepted, the information pertaining
465		to its listener is no longer available.  Therefore, modules
466		interested in finding out the listening socket should install
467		the appropriate socket filter callback (sf_attach) which gets
468		invoked prior to the socket being fully accepted, and call
469		this routine at such a time to obtain the listener.  Callers
470		are guaranteed that the listener socket will not go away
471		during the sf_attach callback, and therefore the value is
472		safe to be used only in that callback context.  Callers should
473		therefore take note that the listening socket's lock will be
474		held throughout the duration of the callback.
475	@param so The pre-accepted socket.
476	@result Non-NULL value which indicates the listening socket; otherwise,
477		NULL if the socket is not in the incomplete/completed list
478		of a listener.
479 */
480extern socket_t sock_getlistener(socket_t so);
481
482/*
483	@function sock_getaddr
484	@discussion Retrieves the local or remote address of a socket.
485		This is a composite of sock_getpeername and sock_getsockname,
486		except that the allocated socket address is returned to the
487		caller, and that the caller is reponsible for calling
488		sock_freeaddr once finished with it.
489	@param so The socket.
490	@param psockname Pointer to the storage for the socket name.
491	@param peername 0 for local address, and non-zero for peer address.
492	@result 0 on success otherwise the errno error.
493 */
494extern errno_t sock_getaddr(socket_t so, struct sockaddr **psockname,
495    int peername);
496
497/*
498	@function sock_freeaddr
499	@discussion Frees the socket address allocated by sock_getaddr.
500	@param sockname The socket name to be freed.
501 */
502extern void sock_freeaddr(struct sockaddr *sockname);
503
504/*
505	@function sock_setupcall
506	@discussion Set the notifier function to be called when an event
507		occurs on the socket. This may be set to NULL to disable
508		further notifications. Setting the function does not
509		affect currently notifications about to be sent or being sent.
510		Note: When this function is used on a socket passed from
511		userspace it is crucial to call sock_retain() on the socket
512		otherwise a callback could be dispatched on a closed socket
513		and cause a crash.
514	@param sock The socket.
515	@param callback The notifier function
516	@param context A cookie passed directly to the callback
517*/
518extern errno_t sock_setupcall(socket_t sock, sock_upcall callback,
519    void *context);
520
521/*
522	@function sock_setupcalls
523	@discussion Set the notifier function to be called when an event
524		occurs on the socket. This may be set to NULL to disable
525		further notifications. Setting the function does not
526		affect currently notifications about to be sent or being sent.
527		Note: When this function is used on a socket passed from
528		userspace it is crucial to call sock_retain() on the socket
529		otherwise a callback could be dispatched on a closed socket
530		and cause a crash.
531	@param sock The socket.
532	@param read_callback The read notifier function
533	@param read_context A cookie passed directly to the read callback
534	@param write_callback The write notifier function
535	@param write_context A cookie passed directly to the write callback
536*/
537extern errno_t sock_setupcalls(socket_t sock, sock_upcall read_callback,
538    void *read_context, sock_upcall write_callback, void *write_context);
539
540/*
541	@function sock_catchevents
542	@discussion Set the notifier function to be called when an event
543		occurs on the socket. This may be set to NULL to disable
544		further notifications. Setting the function does not
545		affect currently notifications about to be sent or being sent.
546	@param sock The socket.
547	@param event_callback The event notifier function
548	@param event_context A cookie passed directly to the event callback
549	@param event_mask One or more SO_FILT_HINT_* values OR'ed together,
550		indicating the registered event(s).
551*/
552extern errno_t sock_catchevents(socket_t sock, sock_evupcall event_callback,
553    void *event_context, u_int32_t event_mask);
554#endif /* KERNEL_PRIVATE */
555
556__END_DECLS
557#endif /* __KPI_SOCKET__ */
558