1/*
2 * Copyright (c) 2008-2011 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
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14 *
15 * Please obtain a copy of the License at
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27 */
28/*!
29	@header kpi_mbuf.h
30	This header defines an API for interacting with mbufs. mbufs are the
31	primary method of storing packets in the networking stack.
32
33	mbufs are used to store various items in the networking stack. The
34	most common usage of an mbuf is to store a packet or data on a
35	socket waiting to be sent or received. The mbuf is a contiguous
36	structure with some header followed by some data. To store more data
37	than would fit in an mbuf, external data is used. Most mbufs with
38	external data use clusters to store the external data.
39
40	mbufs can be chained, contiguous data in a packet can be found by
41	following the m_next chain. Packets may be bundled together using
42	m_nextpacket. Many parts of the stack do not properly handle chains
43	of packets. When in doubt, don't chain packets.
44 */
45
46#ifndef __KPI_MBUF__
47#define __KPI_MBUF__
48#include <sys/kernel_types.h>
49#include <mach/vm_types.h>
50
51/*!
52	@enum mbuf_flags_t
53	@abstract Constants defining mbuf flags. Only the flags listed below
54		can be set or retrieved.
55	@constant MBUF_EXT Indicates this mbuf has external data.
56	@constant MBUF_PKTHDR Indicates this mbuf has a packet header.
57	@constant MBUF_EOR Indicates this mbuf is the end of a record.
58	@constant MBUF_LOOP Indicates this packet is looped back.
59	@constant MBUF_BCAST Indicates this packet will be sent or was
60		received as a brodcast.
61	@constant MBUF_MCAST Indicates this packet will be sent or was
62		received as a multicast.
63	@constant MBUF_FRAG Indicates this packet is a fragment of a larger
64		packet.
65	@constant MBUF_FIRSTFRAG Indicates this packet is the first fragment.
66	@constant MBUF_LASTFRAG Indicates this packet is the last fragment.
67	@constant MBUF_PROMISC Indicates this packet was only received
68		because the interface is in promiscuous mode. This should be set
69		by the demux function. These packets will be discarded after
70		being passed to any interface filters.
71*/
72enum {
73	MBUF_EXT	= 0x0001,	/* has associated external storage */
74	MBUF_PKTHDR	= 0x0002,	/* start of record */
75	MBUF_EOR	= 0x0004,	/* end of record */
76	MBUF_LOOP	= 0x0040,	/* packet is looped back */
77
78	MBUF_BCAST	= 0x0100,	/* send/received as link-level broadcast */
79	MBUF_MCAST	= 0x0200,	/* send/received as link-level multicast */
80	MBUF_FRAG	= 0x0400,	/* packet is a fragment of a larger packet */
81	MBUF_FIRSTFRAG	= 0x0800,	/* packet is first fragment */
82	MBUF_LASTFRAG	= 0x1000,	/* packet is last fragment */
83	MBUF_PROMISC	= 0x2000,	/* packet is promiscuous */
84	MBUF_HASFCS	= 0x4000	/* packet has FCS */
85};
86typedef u_int32_t mbuf_flags_t;
87
88/*!
89	@enum mbuf_type_t
90	@abstract Types of mbufs.
91	@discussion Some mbufs represent packets, some represnt data waiting
92		on sockets. Other mbufs store control data or other various
93		structures. The mbuf type is used to store what sort of data the
94		mbuf contains.
95	@constant MBUF_MT_FREE Indicates the mbuf is free and is
96		sitting on the queue of free mbufs. If you find that an mbuf you
97		have a reference to has this type, something has gone terribly
98		wrong.
99	@constant MBUF_MT_DATA Indicates this mbuf is being used to store
100		data.
101	@constant MBUF_MT_HEADER Indicates this mbuf has a packet header,
102		this is probably a packet.
103	@constant MBUF_MT_SOCKET Socket structure.
104	@constant MBUF_MT_PCB Protocol control block.
105	@constant MBUF_MT_RTABLE Routing table entry.
106	@constant MBUF_MT_HTABLE IMP host tables???.
107	@constant MBUF_MT_ATABLE Address resolution table data.
108	@constant MBUF_MT_SONAME Socket name, usually a sockaddr of some
109		sort.
110	@constant MBUF_MT_FTABLE Fragment reassembly header.
111	@constant MBUF_MT_RIGHTS Access rights.
112	@constant MBUF_MT_IFADDR Interface address.
113	@constant MBUF_MT_CONTROL Extra-data protocol message (control
114		message).
115	@constant MBUF_MT_OOBDATA Out of band data.
116*/
117enum {
118	MBUF_TYPE_FREE		= 0,	/* should be on free list */
119	MBUF_TYPE_DATA		= 1,	/* dynamic (data) allocation */
120	MBUF_TYPE_HEADER	= 2,	/* packet header */
121	MBUF_TYPE_SOCKET	= 3,	/* socket structure */
122	MBUF_TYPE_PCB		= 4,	/* protocol control block */
123	MBUF_TYPE_RTABLE	= 5,	/* routing tables */
124	MBUF_TYPE_HTABLE	= 6,	/* IMP host tables */
125	MBUF_TYPE_ATABLE	= 7,	/* address resolution tables */
126	MBUF_TYPE_SONAME	= 8,	/* socket name */
127	MBUF_TYPE_SOOPTS	= 10,	/* socket options */
128	MBUF_TYPE_FTABLE	= 11,	/* fragment reassembly header */
129	MBUF_TYPE_RIGHTS	= 12,	/* access rights */
130	MBUF_TYPE_IFADDR	= 13,	/* interface address */
131	MBUF_TYPE_CONTROL	= 14,	/* extra-data protocol message */
132	MBUF_TYPE_OOBDATA	= 15	/* expedited data  */
133};
134typedef u_int32_t mbuf_type_t;
135
136/*!
137	@enum mbuf_csum_request_flags_t
138	@abstract Checksum performed/requested flags.
139	@discussion Mbufs often contain packets. Some hardware supports
140		performing checksums in hardware. The stack uses these flags to
141		indicate to the driver what sort of checksumming should be
142		handled in by the driver/hardware. These flags will only be set
143		if the driver indicates that it supports the corresponding
144		checksums using ifnet_set_offload.
145	@constant MBUF_CSUM_REQ_IP Indicates the IP checksum has not been
146		calculated yet.
147	@constant MBUF_CSUM_REQ_TCP Indicates the TCP checksum has not been
148		calculated yet.
149	@constant MBUF_CSUM_REQ_UDP Indicates the UDP checksum has not been
150		calculated yet.
151	@constant MBUF_CSUM_REQ_TCPIPV6 Indicates the TCP checksum for IPv6
152       		has not been calculated yet.
153	@constant MBUF_CSUM_REQ_UDPIPV6 Indicates the UDP checksum for IPv6
154		has not been calculated yet.
155*/
156enum {
157	MBUF_TSO_IPV4		= 0x100000,
158	MBUF_TSO_IPV6		= 0x200000
159};
160typedef u_int32_t mbuf_tso_request_flags_t;
161
162enum {
163#ifdef KERNEL_PRIVATE
164	MBUF_CSUM_REQ_SUM16	= 0x1000, /* Weird apple hardware checksum */
165#endif /* KERNEL_PRIVATE */
166	MBUF_CSUM_REQ_IP	= 0x0001,
167	MBUF_CSUM_REQ_TCP	= 0x0002,
168	MBUF_CSUM_REQ_UDP	= 0x0004,
169	MBUF_CSUM_REQ_TCPIPV6	= 0x0020,
170	MBUF_CSUM_REQ_UDPIPV6	= 0x0040
171};
172typedef u_int32_t mbuf_csum_request_flags_t;
173
174/*!
175	@enum mbuf_csum_performed_flags_t
176	@abstract Checksum performed/requested flags.
177	@discussion Mbufs often contain packets. Some hardware supports
178		performing checksums in hardware. The driver uses these flags to
179		communicate to the stack the checksums that were calculated in
180		hardware.
181	@constant MBUF_CSUM_DID_IP Indicates that the driver/hardware verified
182		the IP checksum in hardware.
183	@constant MBUF_CSUM_IP_GOOD Indicates whether or not the IP checksum
184		was good or bad. Only valid when MBUF_CSUM_DID_IP is set.
185	@constant MBUF_CSUM_DID_DATA Indicates that the TCP or UDP checksum
186		was calculated. The value for the checksum calculated in
187		hardware should be passed as the second parameter of
188		mbuf_set_csum_performed. The hardware calculated checksum value
189		can be retrieved using the second parameter passed to
190		mbuf_get_csum_performed. This should be done for IPv4 or IPv6.
191	@constant MBUF_CSUM_PSEUDO_HDR If set, this indicates that the
192		checksum value for MBUF_CSUM_DID_DATA includes the pseudo header
193		value. If this is not set, the stack will calculate the pseudo
194		header value and add that to the checksum. The value of this bit
195		is only valid when MBUF_CSUM_DID_DATA is set.
196*/
197enum {
198#ifdef KERNEL_PRIVATE
199	MBUF_CSUM_TCP_SUM16	= MBUF_CSUM_REQ_SUM16,	/* Weird apple hardware checksum */
200#endif /* KERNEL_PRIVATE */
201	MBUF_CSUM_DID_IP	= 0x0100,
202	MBUF_CSUM_IP_GOOD	= 0x0200,
203	MBUF_CSUM_DID_DATA	= 0x0400,
204	MBUF_CSUM_PSEUDO_HDR	= 0x0800
205};
206typedef u_int32_t mbuf_csum_performed_flags_t;
207
208/*!
209	@enum mbuf_how_t
210	@abstract Method of allocating an mbuf.
211	@discussion Blocking will cause the funnel to be dropped. If the
212		funnel is dropped, other threads may make changes to networking
213		data structures. This can lead to very bad things happening.
214		Blocking on the input our output path can also impact
215		performance. There are some cases where making a blocking call
216		is acceptable. When in doubt, use MBUF_DONTWAIT.
217	@constant MBUF_WAITOK Allow a call to allocate an mbuf to block.
218	@constant MBUF_DONTWAIT Don't allow the mbuf allocation call to
219		block, if blocking is necessary fail and return immediately.
220*/
221enum {
222	MBUF_WAITOK	= 0,	/* Ok to block to get memory */
223	MBUF_DONTWAIT	= 1	/* Don't block, fail if blocking would be required */
224};
225typedef u_int32_t mbuf_how_t;
226
227typedef u_int32_t mbuf_tag_id_t;
228typedef	u_int16_t mbuf_tag_type_t;
229
230/*!
231	@struct mbuf_stat
232	@discussion The mbuf_stat contains mbuf statistics.
233	@field mbufs Number of mbufs (free or otherwise).
234	@field clusters Number of clusters (free or otherwise).
235	@field clfree Number of free clusters.
236	@field drops Number of times allocation failed.
237	@field wait Number of times allocation blocked.
238	@field drain Number of times protocol drain functions were called.
239	@field mtypes An array of counts of each type of mbuf allocated.
240	@field mcfail Number of times m_copym failed.
241	@field mpfail Number of times m_pullup failed.
242	@field msize Length of an mbuf.
243	@field mclbytes Length of an mbuf cluster.
244	@field minclsize Minimum length of data to allocate a cluster.
245		Anything smaller than this should be placed in chained mbufs.
246	@field mlen Length of data in an mbuf.
247	@field mhlen Length of data in an mbuf with a packet header.
248	@field bigclusters Number of big clusters.
249	@field bigclfree Number of unused big clusters.
250	@field bigmclbytes Length of a big mbuf cluster.
251*/
252struct mbuf_stat {
253	u_int32_t	mbufs;		/* mbufs obtained from page pool */
254	u_int32_t	clusters;	/* clusters obtained from page pool */
255	u_int32_t	clfree;		/* free clusters */
256	u_int32_t	drops;		/* times failed to find space */
257	u_int32_t	wait;		/* times waited for space */
258	u_int32_t	drain;		/* times drained protocols for space */
259	u_short		mtypes[256];	/* type specific mbuf allocations */
260	u_int32_t	mcfail;		/* times m_copym failed */
261	u_int32_t	mpfail;		/* times m_pullup failed */
262	u_int32_t	msize;		/* length of an mbuf */
263	u_int32_t	mclbytes;	/* length of an mbuf cluster */
264	u_int32_t	minclsize;	/* min length of data to allocate a cluster */
265	u_int32_t	mlen;		/* length of data in an mbuf */
266	u_int32_t	mhlen;		/* length of data in a header mbuf */
267	u_int32_t	bigclusters;	/* number of big clusters */
268	u_int32_t	bigclfree;	/* number of big clustser free */
269	u_int32_t	bigmclbytes;	/* length of data in a big cluster */
270};
271
272/* Parameter for m_copym to copy all bytes */
273#define	MBUF_COPYALL	1000000000
274
275__BEGIN_DECLS
276/* Data access */
277/*!
278	@function mbuf_data
279	@discussion Returns a pointer to the start of data in this mbuf.
280		There may be additional data on chained mbufs. The data you're
281		looking for may not be virtually contiguous if it spans more
282		than one mbuf.  In addition, data that is virtually contiguous
283		might not be represented by physically contiguous pages; see
284		further comments in mbuf_data_to_physical.  Use mbuf_len to
285		determine the lenght of data available in this mbuf. If a data
286		structure you want to access stradles two mbufs in a chain,
287		either use mbuf_pullup to get the data contiguous in one mbuf
288		or copy the pieces of data from each mbuf in to a contiguous
289		buffer. Using mbuf_pullup has the advantage of not having to
290		copy the data. On the other hand, if you don't make sure there
291		is space in the mbuf, mbuf_pullup may fail and free the mbuf.
292	@param mbuf The mbuf.
293	@result A pointer to the data in the mbuf.
294 */
295extern void *mbuf_data(mbuf_t mbuf);
296
297/*!
298	@function mbuf_datastart
299	@discussion Returns the start of the space set aside for storing
300		data in an mbuf. An mbuf's data may come from a cluster or be
301		embedded in the mbuf structure itself. The data pointer
302		retrieved by mbuf_data may not be at the start of the data
303		(mbuf_leadingspace will be non-zero). This function will return
304		a pointer that matches mbuf_data() - mbuf_leadingspace().
305	@param mbuf The mbuf.
306	@result A pointer to smallest possible value for data.
307 */
308extern void *mbuf_datastart(mbuf_t mbuf);
309
310/*!
311	@function mbuf_setdata
312	@discussion Sets the data and length values for an mbuf. The data
313	value must be in a valid range. In the case of an mbuf with a cluster,
314	the data value must point to a location in the cluster and the data
315	value plus the length, must be less than the end of the cluster. For
316	data embedded directly in an mbuf (no cluster), the data value must
317	fall somewhere between the start and end of the data area in the
318	mbuf and the data + length must also be in the same range.
319	@param mbuf The mbuf.
320	@param data The new pointer value for data.
321	@param len The new length of data in the mbuf.
322	@result 0 on success, errno error on failure.
323 */
324extern errno_t mbuf_setdata(mbuf_t mbuf, void *data, size_t len);
325
326/*!
327	@function mbuf_align_32
328	@discussion mbuf_align_32 is a replacement for M_ALIGN and MH_ALIGN.
329		mbuf_align_32 will set the data pointer to a location aligned on
330		a four byte boundry with at least 'len' bytes between the data
331		pointer and the end of the data block.
332	@param mbuf The mbuf.
333	@param len The minimum length of space that should follow the new
334		data location.
335	@result 0 on success, errno error on failure.
336 */
337extern errno_t mbuf_align_32(mbuf_t mbuf, size_t len);
338
339/*!
340	@function mbuf_data_to_physical
341	@discussion mbuf_data_to_physical is a replacement for mcl_to_paddr.
342		Given a pointer returned from mbuf_data of mbuf_datastart,
343		mbuf_data_to_physical will return the phyical address for that
344		block of data.  Note that even though the data is in virtually
345		contiguous span, the underlying physical pages might not be
346		physically contiguous.  Because of this, callers must ensure
347		to call this routine for each page boundary.  Device drivers
348		that deal with DMA are strongly encouraged to utilize the
349		IOMbufNaturalMemoryCursor and walk down the list of vectors
350		instead of using this interface to obtain the physical address.
351		Use of this routine is therefore discouraged.
352	@param ptr A pointer to data stored in an mbuf.
353	@result The 64 bit physical address of the mbuf data or NULL if ptr
354		does not point to data stored in an mbuf.
355 */
356extern addr64_t mbuf_data_to_physical(void *ptr);
357
358
359/* Allocation */
360
361/*!
362	@function mbuf_get
363	@discussion Allocates an mbuf without a cluster for external data.
364	@param how Blocking or non-blocking.
365	@param type The type of the mbuf.
366	@param mbuf The mbuf.
367	@result 0 on success, errno error on failure.
368 */
369extern errno_t mbuf_get(mbuf_how_t how, mbuf_type_t type, mbuf_t *mbuf);
370
371/*!
372	@function mbuf_gethdr
373	@discussion Allocates an mbuf without a cluster for external data.
374		Sets a flag to indicate there is a packet header and initializes
375		the packet header.
376	@param how Blocking or non-blocking.
377	@param type The type of the mbuf.
378	@param mbuf The mbuf.
379	@result 0 on success, errno error on failure.
380 */
381extern errno_t mbuf_gethdr(mbuf_how_t how, mbuf_type_t type, mbuf_t *mbuf);
382
383/*!
384	@function mbuf_attachcluster
385	@discussion Attach an external buffer as a cluster for an mbuf.  If mbuf
386		points to a NULL mbuf_t, an mbuf will be allocated for you.  If
387		mbuf points to a non-NULL mbuf_t, the user-supplied mbuf will
388		be used instead.  The caller is responsible for allocating the
389		external buffer by calling mbuf_alloccluster().
390	@param how Blocking or non-blocking.
391	@param type The type of the mbuf if mbuf is non-NULL; otherwise ignored.
392	@param mbuf Pointer to the address of the mbuf; if NULL, an mbuf will
393		be allocated, otherwise, it must point to a valid mbuf address.
394		If the user-supplied mbuf is already attached to a cluster, the
395		current cluster will be freed before the mbuf gets attached to
396		the supplied external buffer.  Note that this routine may return
397		a different mbuf_t than the one you passed in.
398	@param extbuf Address of the external buffer.
399	@param extfree Free routine for the external buffer; the caller is
400		required to defined a routine that will be invoked when the
401		mbuf is freed.
402	@param extsize Size of the external buffer.
403	@param extarg Private value that will be passed to the free routine
404		when it is called at the time the mbuf is freed.
405	@result 0 on success
406		EINVAL - Invalid parameter
407		ENOMEM - Not enough memory available
408 */
409extern errno_t mbuf_attachcluster(mbuf_how_t how, mbuf_type_t type,
410    mbuf_t *mbuf, caddr_t extbuf, void (*extfree)(caddr_t , u_int, caddr_t),
411    size_t extsize, caddr_t extarg);
412
413/*!
414	@function mbuf_alloccluster
415	@discussion Allocate a cluster that can be later attached to an
416		mbuf by calling mbuf_attachcluster().  The allocated cluster
417		can also be freed (without being attached to an mbuf) by
418		calling mbuf_freecluster().  At the moment this routine
419		will either return a cluster of 2048, 4096 or 16384 bytes
420		depending on the requested size.  Note that clusters greater
421		than 4096 bytes might not be available in all configurations;
422		the caller must additionally check for ENOTSUP (see below).
423	@param how Blocking or non-blocking.
424	@param size Pointer to size of requested cluster.  Sizes up to 2048
425		will be rounded up to 2048; sizes greater than 2048 and up
426		to 4096 will be rounded up to 4096.  Sizes greater than 4096
427		will be rounded up to 16384.
428	@param addr Pointer to the address of the requested cluster.
429	@result 0 on success or ENOMEM if failure.  If the caller requests
430		greater than 4096 bytes and the system is unable to fulfill
431		the request due to the lack of jumbo clusters support based
432		on the configuration, this routine will return ENOTSUP.
433		In this case, the caller is advised to use 4096 bytes or
434		smaller during subseqent requests.
435 */
436extern errno_t mbuf_alloccluster(mbuf_how_t how, size_t *size, caddr_t *addr);
437
438/*!
439	@function mbuf_freecluster
440	@discussion Free a cluster that was previously allocated by a call
441		to mbuf_alloccluster().  The caller must pass the actual
442		size of the cluster as returned by mbuf_alloccluster(),
443		which at this point must be either 2048, 4096 or 16384 bytes.
444	@param addr The address of the cluster.
445	@param size The actual size of the cluster.
446 */
447extern void mbuf_freecluster(caddr_t addr, size_t size);
448
449/*!
450	@function mbuf_getcluster
451	@discussion Allocate a cluster of the requested size and attach it to
452		an mbuf for use as external data. If mbuf points to a NULL
453		mbuf_t, an mbuf will be allocated for you. If mbuf points to
454		a non-NULL mbuf_t, mbuf_getcluster may return a different
455		mbuf_t than the one you passed in.
456	@param how Blocking or non-blocking.
457	@param type The type of the mbuf.
458	@param size The size of the cluster to be allocated. Supported sizes
459		for a cluster are be 2048, 4096, or 16384. Any other value
460		with return EINVAL.  Note that clusters greater than 4096
461		bytes might not be available in all configurations; the
462		caller must additionally check for ENOTSUP (see below).
463	@param mbuf The mbuf the cluster will be attached to.
464	@result 0 on success, errno error on failure. If you specified NULL
465		for the mbuf, any intermediate mbuf that may have been allocated
466		will be freed. If you specify an mbuf value in *mbuf,
467		mbuf_mclget will not free it.
468		EINVAL - Invalid parameter
469		ENOMEM - Not enough memory available
470		ENOTSUP - The caller had requested greater than 4096 bytes
471		    cluster and the system is unable to fulfill it due to the
472		    lack of jumbo clusters support based on the configuration.
473		    In this case, the caller is advised to use 4096 bytes or
474		    smaller during subsequent requests.
475 */
476extern errno_t mbuf_getcluster(mbuf_how_t how, mbuf_type_t type, size_t size,
477    mbuf_t *mbuf);
478
479/*!
480	@function mbuf_mclget
481	@discussion Allocate a cluster and attach it to an mbuf for use as
482		external data. If mbuf points to a NULL mbuf_t, an mbuf will be
483		allocated for you. If mbuf points to a non-NULL mbuf_t,
484		mbuf_mclget may return a different mbuf_t than the one you
485		passed in.
486	@param how Blocking or non-blocking.
487	@param type The type of the mbuf.
488	@param mbuf The mbuf the cluster will be attached to.
489	@result 0 on success, errno error on failure. If you specified NULL
490		for the mbuf, any intermediate mbuf that may have been allocated
491		will be freed. If you specify an mbuf value in *mbuf,
492		mbuf_mclget will not free it.
493 */
494extern errno_t mbuf_mclget(mbuf_how_t how, mbuf_type_t type, mbuf_t *mbuf);
495
496/*!
497	@function mbuf_allocpacket
498	@discussion Allocate an mbuf chain to store a single packet of the
499		requested length.  According to the requested length, a chain
500		of mbufs will be created. The mbuf type will be set to
501		MBUF_TYPE_DATA. The caller may specify the maximum number of
502		buffer.
503	@param how Blocking or non-blocking
504	@param packetlen The total length of the packet mbuf to be allocated.
505		The length must be greater than zero.
506	@param maxchunks An input/output pointer to the maximum number of mbufs
507		segments making up the chain.  On input, if maxchunks is NULL,
508		or the value pointed to by maxchunks is zero, the packet will
509		be made up of as few or as many buffer segments as necessary
510		to fit the length.  The allocation will fail with ENOBUFS if
511		the number of segments requested is too small and the sum of
512		the maximum size of each individual segment is less than the
513		packet length.  On output, if the allocation succeed and
514		maxchunks is non-NULL, it will point to the actual number
515		of segments allocated.
516		Additional notes for packetlen greater than 4096 bytes:
517		the caller may pass a non-NULL maxchunks and initialize it
518		with zero such that upon success, it can find out whether
519		or not the system configuration allows for larger than
520		4096 bytes cluster allocations, by checking on the value
521		pointed to by maxchunks.  E.g. a request for 9018 bytes may
522		result in 1 chunk when jumbo clusters are available, or
523		3 chunks otherwise.
524	@param Upon success, *mbuf will be a reference to the new mbuf.
525	@result Returns 0 upon success or the following error code:
526		EINVAL - Invalid parameter
527		ENOMEM - Not enough memory available
528		ENOBUFS - Buffers not big enough for the maximum number of
529		    chunks requested
530*/
531extern errno_t mbuf_allocpacket(mbuf_how_t how, size_t packetlen,
532    unsigned int * maxchunks, mbuf_t *mbuf);
533
534/*!
535	@function mbuf_allocpacket_list
536	@discussion Allocate a linked list of packets.  According to the
537		requested length, each packet will made of a chain of one
538		or more mbufs.  The mbuf type will be set to MBUF_TYPE_DATA.
539		The caller may specify the maximum number of element for
540		each mbuf chain making up a packet.
541	@param numpkts Number of packets to allocate
542	@param how Blocking or non-blocking
543	@param packetlen The total length of the packet mbuf to be allocated.
544		The length must be greater than zero.
545	@param maxchunks An input/output pointer to the maximum number of
546		mbufs segments making up the chain.  On input, if maxchunks is
547		zero, or the value pointed to by maxchunks is zero, the packet
548		will be made of as few or as many buffer segments as necessary
549		to fit the length.  The allocation will fail with ENOBUFS if
550		the number of segments requested is too small and the sum of
551		the maximum size of each individual segment is less than the
552		packet length.  On output, if the allocation succeed and
553		maxchunks is non zero, it will point to the actual number
554		of segments allocated.
555		Additional notes for packetlen greater than 4096 bytes:
556		the caller may pass a non-NULL maxchunks and initialize it
557		with zero such that upon success, it can find out whether
558		or not the system configuration allows for larger than
559		4096 bytes cluster allocations, by checking on the value
560		pointed to by maxchunks.  E.g. a request for 9018 bytes may
561		result in 1 chunk when jumbo clusters are available, or
562		3 chunks otherwise.
563	@param Upon success, *mbuf will be a reference to the new mbuf.
564	@result Returns 0 upon success or the following error code:
565		EINVAL - Invalid parameter
566		ENOMEM - Not enough memory available
567		ENOBUFS - Buffers not big enough for the maximum number of
568		    chunks requested
569*/
570extern errno_t mbuf_allocpacket_list(unsigned int numpkts, mbuf_how_t how,
571    size_t packetlen, unsigned int * maxchunks, mbuf_t *mbuf);
572
573
574/*!
575	@function mbuf_getpacket
576	@discussion Allocate an mbuf, allocate and attach a cluster, and set
577		the packet header flag.
578	@param how Blocking or non-blocking.
579	@param mbuf Upon success, *mbuf will be a reference to the new mbuf.
580	@result 0 on success, errno error on failure.
581 */
582extern errno_t mbuf_getpacket(mbuf_how_t how, mbuf_t *mbuf);
583
584/*!
585	@function mbuf_free
586	@discussion Frees a single mbuf. Not commonly used because it
587		doesn't touch the rest of the mbufs on the chain.
588	@param mbuf The mbuf to free.
589	@result The next mbuf in the chain.
590 */
591extern mbuf_t mbuf_free(mbuf_t mbuf);
592
593/*!
594	@function mbuf_freem
595	@discussion Frees a chain of mbufs link through mnext.
596	@param mbuf The first mbuf in the chain to free.
597 */
598extern void mbuf_freem(mbuf_t mbuf);
599
600/*!
601	@function mbuf_freem_list
602	@discussion Frees linked list of mbuf chains. Walks through
603		mnextpackt and does the equivalent of mbuf_freem to each.
604	@param mbuf The first mbuf in the linked list to free.
605	@result The number of mbufs freed.
606 */
607extern int mbuf_freem_list(mbuf_t mbuf);
608
609/*!
610	@function mbuf_leadingspace
611	@discussion Determines the space available in the mbuf proceeding
612		the current data.
613	@param mbuf The mbuf.
614	@result The number of unused bytes at the start of the mbuf.
615 */
616extern size_t mbuf_leadingspace(const mbuf_t mbuf);
617
618/*!
619	@function mbuf_trailingspace
620	@discussion Determines the space available in the mbuf following
621		the current data.
622	@param mbuf The mbuf.
623	@result The number of unused bytes following the current data.
624 */
625extern size_t mbuf_trailingspace(const mbuf_t mbuf);
626
627/* Manipulation */
628
629/*!
630	@function mbuf_copym
631	@discussion Copies len bytes from offset from src to a new mbuf.  If
632	    the original mbuf contains a packet header, the new mbuf will
633	    contain similar packet header except for any tags which may be
634	    associated with the original mbuf.  mbuf_dup() should be used
635	    instead if tags are to be copied to the new mbuf.
636	@param src The source mbuf.
637	@param offset The offset in the mbuf to start copying from.
638	@param len The the number of bytes to copy.
639	@param how To block or not to block, that is a question.
640	@param new_mbuf Upon success, the newly allocated mbuf.
641	@result 0 upon success otherwise the errno error.
642 */
643extern errno_t mbuf_copym(const mbuf_t src, size_t offset, size_t len,
644    mbuf_how_t how, mbuf_t *new_mbuf);
645
646/*!
647	@function mbuf_dup
648	@discussion Exactly duplicates an mbuf chain.  If the original mbuf
649	    contains a packet header (including tags), the new mbuf will have
650	    the same packet header contents and a copy of each tag associated
651	    with the original mbuf.
652	@param src The source mbuf.
653	@param how Blocking or non-blocking.
654	@param new_mbuf Upon success, the newly allocated mbuf.
655	@result 0 upon success otherwise the errno error.
656 */
657extern errno_t mbuf_dup(const mbuf_t src, mbuf_how_t how, mbuf_t *new_mbuf);
658
659/*!
660	@function mbuf_prepend
661	@discussion Prepend len bytes to an mbuf. If there is space
662		(mbuf_leadingspace >= len), the mbuf's data ptr is changed and
663		the same mbuf is returned. If there is no space, a new mbuf may
664		be allocated and prepended to the mbuf chain. If the operation
665		fails, the mbuf may be freed (*mbuf will be NULL).
666	@param mbuf The mbuf to prepend data to. This may change if a new
667		mbuf must be allocated or may be NULL if the operation fails.
668	@param len The length, in bytes, to be prepended to the mbuf.
669	@param how Blocking or non-blocking.
670	@result 0 upon success otherwise the errno error.
671 */
672extern errno_t mbuf_prepend(mbuf_t *mbuf, size_t len, mbuf_how_t how);
673
674/*!
675	@function mbuf_split
676	@discussion Split an mbuf chain at a specific offset.
677	@param src The mbuf to be split.
678	@param offset The offset in the buffer where the mbuf should be
679		split.
680	@param how Blocking or non-blocking.
681	@param new_mbuf Upon success, the second half of the split mbuf
682		chain.
683	@result 0 upon success otherwise the errno error. In the case of
684		failure, the original mbuf chain passed in to src will be
685		preserved.
686 */
687extern errno_t mbuf_split(mbuf_t src, size_t offset, mbuf_how_t how,
688    mbuf_t *new_mbuf);
689
690/*!
691	@function mbuf_pullup
692	@discussion Move the next len bytes in to mbuf from other mbufs in
693		the chain. This is commonly used to get the IP and TCP or UDP
694		header contiguous in the first mbuf. If mbuf_pullup fails, the
695		entire mbuf chain will be freed.
696	@param mbuf The mbuf in the chain the data should be contiguous in.
697	@param len The number of bytes to pull from the next mbuf(s).
698	@result 0 upon success otherwise the errno error. In the case of an
699		error, the mbuf chain has been freed.
700 */
701extern errno_t mbuf_pullup(mbuf_t *mbuf, size_t len);
702
703/*!
704	@function mbuf_pulldown
705	@discussion Make length bytes at offset in the mbuf chain
706		contiguous. Nothing before offset bytes in the chain will be
707		modified. Upon return, location will be the mbuf the data is
708		contiguous in and offset will be the offset in that mbuf at
709		which the data is located.  In the case of a failure, the mbuf
710		chain will be freed.
711	@param src The start of the mbuf chain.
712	@param offset Pass in a pointer to a value with the offset of the
713		data you're interested in making contiguous. Upon success, this
714		will be overwritten with the offset from the mbuf returned in
715		location.
716	@param length The length of data that should be made contiguous.
717	@param location Upon success, *location will be the mbuf the data is
718		in.
719	@result 0 upon success otherwise the errno error.
720 */
721extern errno_t mbuf_pulldown(mbuf_t src, size_t *offset, size_t length,
722    mbuf_t *location);
723
724/*!
725	@function mbuf_adj
726	@discussion Trims len bytes from the mbuf. If the length is greater
727		than zero, the bytes are trimmed from the front of the mbuf. If
728		the length is less than zero, the bytes are trimmed from the end
729		of the mbuf chain.
730	@param mbuf The mbuf chain to trim.
731	@param len The number of bytes to trim from the mbuf chain.
732 */
733extern void mbuf_adj(mbuf_t mbuf, int len);
734
735/*!
736	@function mbuf_adjustlen
737	@discussion Adds amount to the mbuf len. Verifies that the new
738		length is valid (greater than or equal to zero and less than
739		maximum amount of data that may be stored in the mbuf). This
740		function will not adjust the packet header length field or
741		affect any other mbufs in a chain.
742	@param mbuf The mbuf to adjust.
743	@param amount The number of bytes increment the length by.
744	@result 0 upon success otherwise the errno error.
745 */
746extern errno_t mbuf_adjustlen(mbuf_t mbuf, int amount);
747
748/*!
749	@function mbuf_concatenate
750	@discussion Concatenate mbuf chain src to dst using m_next and return
751		a chain which represents the concatenated chain.  The routine
752		does not prevent two chains of different mbuf types to be
753		concatenated, nor does it modify any packet header in the
754		destination chain.  Therefore, it's the responsibility of the
755		caller to ensure that the resulted concatenated mbuf chain is
756		correct for further usages.
757	@param dst The destination mbuf chain.
758	@param src The source mbuf chain.
759	@result A pointer to the head of the concatenated mbuf chain.  This
760		should be treated as the updated destination mbuf chain; the
761		caller must no longer refer to the original src or dst mbuf
762		chain.  Otherwise it returns NULL if the original dst mbuf
763		chain is NULL.
764 */
765extern mbuf_t mbuf_concatenate(mbuf_t dst, mbuf_t src);
766
767/*!
768	@function mbuf_copydata
769	@discussion Copies data out of an mbuf in to a specified buffer. If
770		the data is stored in a chain of mbufs, the data will be copied
771		from each mbuf in the chain until length bytes have been copied.
772	@param mbuf The mbuf chain to copy data out of.
773	@param offset The offset in to the mbuf to start copying.
774	@param length The number of bytes to copy.
775	@param out_data A pointer to the location where the data will be
776		copied.
777	@result 0 upon success otherwise the errno error.
778 */
779extern errno_t mbuf_copydata(const mbuf_t mbuf, size_t offset, size_t length,
780    void *out_data);
781
782/*!
783	@function mbuf_copyback
784	@discussion Copies data from a buffer to an mbuf chain.
785		mbuf_copyback will grow the chain to fit the specified buffer.
786
787		If mbuf_copydata is unable to allocate enough mbufs to grow the
788		chain, ENOBUFS will be returned. The mbuf chain will be shorter
789		than expected but all of the data up to the end of the mbuf
790		chain will be valid.
791
792		If an offset is specified, mbuf_copyback will skip that many
793		bytes in the mbuf chain before starting to write the buffer in
794		to the chain. If the mbuf chain does not contain this many
795		bytes, mbufs will be allocated to create the space.
796	@param mbuf The first mbuf in the chain to copy the data in to.
797	@param offset Offset in bytes to skip before copying data.
798	@param length The length, in bytes, of the data to copy in to the mbuf
799		chain.
800	@param data A pointer to data in the kernel's address space.
801	@param how Blocking or non-blocking.
802	@result 0 upon success, EINVAL or ENOBUFS upon failure.
803 */
804extern errno_t mbuf_copyback(mbuf_t mbuf, size_t offset, size_t length,
805    const void *data, mbuf_how_t how);
806
807/*!
808	@function mbuf_mclhasreference
809	@discussion Check if a cluster of an mbuf is referenced by another mbuf.
810		References may be taken, for example, as a result of a call to
811		mbuf_split or mbuf_copym
812	@param mbuf The mbuf with the cluster to test.
813	@result 0 if there is no reference by another mbuf, 1 otherwise.
814 */
815extern int mbuf_mclhasreference(mbuf_t mbuf);
816
817
818/* mbuf header */
819
820/*!
821	@function mbuf_next
822	@discussion Returns the next mbuf in the chain.
823	@param mbuf The mbuf.
824	@result The next mbuf in the chain.
825 */
826extern mbuf_t mbuf_next(const mbuf_t mbuf);
827
828/*!
829	@function mbuf_setnext
830	@discussion Sets the next mbuf in the chain.
831	@param mbuf The mbuf.
832	@param next The new next mbuf.
833	@result 0 upon success otherwise the errno error.
834 */
835extern errno_t mbuf_setnext(mbuf_t mbuf, mbuf_t next);
836
837/*!
838	@function mbuf_nextpkt
839	@discussion Gets the next packet from the mbuf.
840	@param mbuf The mbuf.
841	@result The nextpkt.
842 */
843extern mbuf_t mbuf_nextpkt(const mbuf_t mbuf);
844
845/*!
846	@function mbuf_setnextpkt
847	@discussion Sets the next packet attached to this mbuf.
848	@param mbuf The mbuf.
849	@param nextpkt The new next packet.
850 */
851extern void mbuf_setnextpkt(mbuf_t mbuf, mbuf_t nextpkt);
852
853/*!
854	@function mbuf_len
855	@discussion Gets the length of data in this mbuf.
856	@param mbuf The mbuf.
857	@result The length.
858 */
859extern size_t mbuf_len(const mbuf_t mbuf);
860
861/*!
862	@function mbuf_setlen
863	@discussion Sets the length of data in this packet. Be careful to
864		not set the length over the space available in the mbuf.
865	@param mbuf The mbuf.
866	@param len The new length.
867	@result 0 upon success otherwise the errno error.
868 */
869extern void mbuf_setlen(mbuf_t mbuf, size_t len);
870
871/*!
872	@function mbuf_maxlen
873	@discussion Retrieves the maximum length of data that may be stored
874		in this mbuf. This value assumes that the data pointer was set
875		to the start of the possible range for that pointer
876		(mbuf_data_start).
877	@param mbuf The mbuf.
878	@result The maximum lenght of data for this mbuf.
879 */
880extern size_t mbuf_maxlen(const mbuf_t mbuf);
881
882/*!
883	@function mbuf_type
884	@discussion Gets the type of mbuf.
885	@param mbuf The mbuf.
886	@result The type.
887 */
888extern mbuf_type_t mbuf_type(const mbuf_t mbuf);
889
890/*!
891	@function mbuf_settype
892	@discussion Sets the type of mbuf.
893	@param mbuf The mbuf.
894	@param new_type The new type.
895	@result 0 upon success otherwise the errno error.
896 */
897extern errno_t mbuf_settype(mbuf_t mbuf, mbuf_type_t new_type);
898
899/*!
900	@function mbuf_flags
901	@discussion Returns the set flags.
902	@param mbuf The mbuf.
903	@result The flags.
904 */
905extern mbuf_flags_t mbuf_flags(const mbuf_t mbuf);
906
907/*!
908	@function mbuf_setflags
909	@discussion Sets the set of set flags.
910	@param mbuf The mbuf.
911	@param flags The flags that should be set, all other flags will be cleared.
912	@result 0 upon success otherwise the errno error.
913 */
914extern errno_t mbuf_setflags(mbuf_t mbuf, mbuf_flags_t flags);
915
916/*!
917	@function mbuf_setflags_mask
918	@discussion Useful for setting or clearing individual flags. Easier
919		than calling mbuf_setflags(m, mbuf_flags(m) | M_FLAG).
920	@param mbuf The mbuf.
921	@param flags The flags that should be set or cleared.
922	@param mask The mask controlling which flags will be modified.
923	@result 0 upon success otherwise the errno error.
924 */
925extern errno_t mbuf_setflags_mask(mbuf_t mbuf, mbuf_flags_t flags,
926    mbuf_flags_t mask);
927
928/*!
929	@function mbuf_copy_pkthdr
930	@discussion Copies the packet header from src to dest.
931	@param src The mbuf from which the packet header will be copied.
932	@param mbuf The mbuf to which the packet header will be copied.
933	@result 0 upon success otherwise the errno error.
934 */
935extern errno_t mbuf_copy_pkthdr(mbuf_t dest, const mbuf_t src);
936
937/*!
938	@function mbuf_pkthdr_len
939	@discussion Returns the length as reported by the packet header.
940	@param mbuf The mbuf containing the packet header with the length to
941		be changed.
942	@result The length, in bytes, of the packet.
943 */
944extern size_t mbuf_pkthdr_len(const mbuf_t mbuf);
945
946/*!
947	@function mbuf_pkthdr_setlen
948	@discussion Sets the length of the packet in the packet header.
949	@param mbuf The mbuf containing the packet header.
950	@param len The new length of the packet.
951 */
952extern void mbuf_pkthdr_setlen(mbuf_t mbuf, size_t len);
953
954/*!
955	@function mbuf_pkthdr_adjustlen
956	@discussion Adjusts the length of the packet in the packet header.
957	@param mbuf The mbuf containing the packet header.
958	@param amount The number of bytes to adjust the packet header length
959		field by.
960 */
961extern void mbuf_pkthdr_adjustlen(mbuf_t mbuf, int amount);
962
963/*!
964	@function mbuf_pkthdr_rcvif
965	@discussion Returns the interface the packet was received on. This
966		funciton does not modify the reference count of the interface.
967		The interface is only valid for as long as the mbuf is not freed
968		and the rcvif for the mbuf is not changed. Take a reference on
969		the interface that you will release later before doing any of
970		the following: free the mbuf, change the rcvif, pass the mbuf to
971		any function that may free the mbuf or change the rcvif.
972	@param mbuf The mbuf containing the packet header.
973	@result A reference to the interface.
974 */
975extern ifnet_t mbuf_pkthdr_rcvif(const mbuf_t mbuf);
976
977/*!
978	@function mbuf_pkthdr_setrcvif
979	@discussion Sets the interface the packet was received on.
980	@param mbuf The mbuf containing the packet header.
981	@param ifnet A reference to an interface.
982	@result 0 upon success otherwise the errno error.
983 */
984extern errno_t mbuf_pkthdr_setrcvif(mbuf_t mbuf, ifnet_t ifp);
985
986/*!
987	@function mbuf_pkthdr_header
988	@discussion Returns a pointer to the packet header.
989	@param mbuf The mbuf containing the packet header.
990	@result A pointer to the packet header.
991 */
992extern void *mbuf_pkthdr_header(const mbuf_t mbuf);
993
994/*!
995	@function mbuf_pkthdr_setheader
996	@discussion Sets the pointer to the packet header.
997	@param mbuf The mbuf containing the packet header.
998	@param ifnet A pointer to the header.
999	@result 0 upon success otherwise the errno error.
1000 */
1001extern void mbuf_pkthdr_setheader(mbuf_t mbuf, void *header);
1002
1003/* Checksums */
1004
1005/*!
1006	@function mbuf_inbound_modified
1007	@discussion This function will clear the checksum flags to indicate
1008		that a hardware checksum should not be used. Any filter
1009		modifying data should call this function on an mbuf before
1010		passing the packet up the stack. If a filter modifies a packet
1011		in a way that affects any checksum, the filter is responsible
1012		for either modifying the checksum to compensate for the changes
1013		or verifying the checksum before making the changes and then
1014		modifying the data and calculating a new checksum only if the
1015		original checksum was valid.
1016	@param mbuf The mbuf that has been modified.
1017 */
1018extern void mbuf_inbound_modified(mbuf_t mbuf);
1019
1020/*!
1021	@function mbuf_outbound_finalize
1022	@discussion This function will "finalize" the packet allowing your
1023		code to inspect the final packet.
1024
1025		There are a number of operations that are performed in hardware,
1026		such as calculating checksums. This function will perform in
1027		software the various opterations that were scheduled to be done
1028		in hardware. Future operations may include IPSec processing or
1029		vlan support. If you are redirecting a packet to a new interface
1030		which may not have the same hardware support or encapsulating
1031		the packet, you should call this function to force the stack to
1032		calculate and fill out the checksums. This will bypass hardware
1033		checksums but give you a complete packet to work with. If you
1034		need to inspect aspects of the packet which may be generated by
1035		hardware, you must call this function to get an aproximate final
1036		packet. If you plan to modify the packet in any way, you should
1037		call this function.
1038
1039		This function should be called before modifying any outbound
1040		packets.
1041
1042		This function may be called at various levels, in some cases
1043		additional headers may have already been prepended, such as the
1044		case of a packet seen by an interface filter. To handle this,
1045		the caller must pass the protocol family of the packet as well
1046		as the offset from the start of the packet to the protocol
1047		header.
1048	@param mbuf The mbuf that should be finalized.
1049	@param protocol_family The protocol family of the packet in the
1050		mbuf.
1051	@param protocol_offset The offset from the start of the mbuf to the
1052		protocol header. For an IP packet with an ethernet header, this
1053		would be the length of an ethernet header.
1054 */
1055extern void mbuf_outbound_finalize(mbuf_t mbuf, u_int32_t protocol_family,
1056    size_t protocol_offset);
1057
1058/*!
1059	@function mbuf_set_vlan_tag
1060	@discussion This function is used by interfaces that support vlan
1061		tagging in hardware. This function will set properties in the
1062		mbuf to indicate which vlan the packet was received for.
1063	@param mbuf The mbuf containing the packet.
1064	@param vlan The protocol family of the aux data to add.
1065	@result 0 upon success otherwise the errno error.
1066 */
1067extern errno_t mbuf_set_vlan_tag(mbuf_t mbuf, u_int16_t vlan);
1068
1069/*!
1070	@function mbuf_get_vlan_tag
1071	@discussion This function is used by drivers that support hardware
1072		vlan tagging to determine which vlan this packet belongs to. To
1073		differentiate between the case where the vlan tag is zero and
1074		the case where there is no vlan tag, this function will return
1075		ENXIO when there is no vlan.
1076	@param mbuf The mbuf containing the packet.
1077	@param vlan The protocol family of the aux data to add.
1078	@result 0 upon success otherwise the errno error. ENXIO indicates
1079		that the vlan tag is not set.
1080 */
1081extern errno_t mbuf_get_vlan_tag(mbuf_t mbuf, u_int16_t *vlan);
1082
1083/*!
1084	@function mbuf_clear_vlan_tag
1085	@discussion This function will clear any vlan tag associated with
1086		the mbuf.
1087	@param mbuf The mbuf containing the packet.
1088	@result 0 upon success otherwise the errno error.
1089 */
1090extern errno_t mbuf_clear_vlan_tag(mbuf_t mbuf);
1091
1092#ifdef KERNEL_PRIVATE
1093/*
1094	@function mbuf_set_csum_requested
1095	@discussion This function is used by the stack to indicate which
1096		checksums should be calculated in hardware. The stack normally
1097		sets these flags as the packet is processed in the outbound
1098		direction. Just before send the packe to the interface, the
1099		stack will look at these flags and perform any checksums in
1100		software that are not supported by the interface.
1101	@param mbuf The mbuf containing the packet.
1102	@param request Flags indicating which checksums are being requested
1103		for this packet.
1104	@param value This parameter is currently unsupported.
1105	@result 0 upon success otherwise the errno error.
1106 */
1107extern errno_t mbuf_set_csum_requested(mbuf_t mbuf,
1108    mbuf_csum_request_flags_t request, u_int32_t value);
1109#endif /* KERNEL_PRIVATE */
1110
1111/*!
1112	@function mbuf_get_csum_requested
1113	@discussion This function is used by the driver to determine which
1114		checksum operations should be performed in hardware.
1115	@param mbuf The mbuf containing the packet.
1116	@param request Flags indicating which checksums are being requested
1117		for this packet.
1118	@param value This parameter is currently unsupported.
1119	@result 0 upon success otherwise the errno error.
1120 */
1121extern errno_t mbuf_get_csum_requested(mbuf_t mbuf,
1122    mbuf_csum_request_flags_t *request, u_int32_t *value);
1123
1124/*!
1125	@function mbuf_get_tso_requested
1126	@discussion This function is used by the driver to determine which
1127		checksum operations should be performed in hardware.
1128	@param mbuf The mbuf containing the packet.
1129	@param request Flags indicating which values are being requested
1130		for this packet.
1131	@param value The requested value.
1132	@result 0 upon success otherwise the errno error.
1133 */
1134extern errno_t mbuf_get_tso_requested(mbuf_t mbuf,
1135    mbuf_tso_request_flags_t *request, u_int32_t *value);
1136
1137/*!
1138	@function mbuf_clear_csum_requested
1139	@discussion This function clears the checksum request flags.
1140	@param mbuf The mbuf containing the packet.
1141	@result 0 upon success otherwise the errno error.
1142 */
1143extern errno_t mbuf_clear_csum_requested(mbuf_t mbuf);
1144
1145/*!
1146	@function mbuf_set_csum_performed
1147	@discussion This is used by the driver to indicate to the stack which
1148		checksum operations were performed in hardware.
1149	@param mbuf The mbuf containing the packet.
1150	@param flags Flags indicating which hardware checksum operations
1151		were performed.
1152	@param value If the MBUF_CSUM_DID_DATA flag is set, value should be
1153		set to the value of the TCP or UDP header as calculated by the
1154		hardware.
1155	@result 0 upon success otherwise the errno error.
1156 */
1157extern errno_t mbuf_set_csum_performed(mbuf_t mbuf,
1158    mbuf_csum_performed_flags_t flags, u_int32_t value);
1159
1160#ifdef KERNEL_PRIVATE
1161/*
1162	@function mbuf_get_csum_performed
1163	@discussion This is used by the stack to determine which checksums
1164		were calculated in hardware on the inbound path.
1165	@param mbuf The mbuf containing the packet.
1166	@param flags Flags indicating which hardware checksum operations
1167		were performed.
1168	@param value If the MBUF_CSUM_DID_DATA flag is set, value will be
1169		set to the value of the TCP or UDP header as calculated by the
1170		hardware.
1171	@result 0 upon success otherwise the errno error.
1172 */
1173extern errno_t mbuf_get_csum_performed(mbuf_t mbuf,
1174    mbuf_csum_performed_flags_t *flags, u_int32_t *value);
1175#endif /* KERNEL_PRIVATE */
1176
1177/*!
1178	@function mbuf_get_mlen
1179	@discussion This routine returns the number of data bytes in a normal
1180		mbuf, i.e. an mbuf that is not a packet header, nor one with
1181		an external cluster attached to it.  This is equivalent to the
1182		legacy MLEN macro.
1183	@result	The number of bytes of available data.
1184 */
1185extern u_int32_t mbuf_get_mlen(void);
1186
1187/*!
1188	@function mbuf_get_mhlen
1189	@discussion This routine returns the number of data bytes in a packet
1190		header mbuf.  This is equivalent to the legacy MHLEN macro.
1191	@result	The number of bytes of available data.
1192 */
1193extern u_int32_t mbuf_get_mhlen(void);
1194
1195/*!
1196	@function mbuf_get_minclsize
1197	@discussion This routine returns the minimum number of data bytes
1198		before an external cluster is used.  This is equivalent to the
1199		legacy MINCLSIZE macro.
1200	@result	The minimum number of bytes before a cluster will be used.
1201 */
1202extern u_int32_t mbuf_get_minclsize(void);
1203
1204/*!
1205	@function mbuf_clear_csum_performed
1206	@discussion Clears the hardware checksum flags and values.
1207	@param mbuf The mbuf containing the packet.
1208	@result 0 upon success otherwise the errno error.
1209 */
1210extern errno_t mbuf_clear_csum_performed(mbuf_t mbuf);
1211
1212/*!
1213	@function mbuf_inet_cksum
1214	@discussions Calculates 16-bit 1's complement Internet checksum of the
1215		transport segment with or without the pseudo header checksum
1216		of a given IPv4 packet.  If the caller specifies a non-zero
1217		transport protocol, the checksum returned will also include
1218		the pseudo header checksum for the corresponding transport
1219		header.  Otherwise, no header parsing will be done and the
1220		caller may use this to calculate the Internet checksum of
1221		an arbitrary span of data.
1222
1223		This routine does not modify the contents of the packet.  If
1224		the caller specifies a non-zero protocol and/or offset, the
1225		routine expects the complete protocol header to be present
1226		at the beginning of the first mbuf.
1227	@param mbuf The mbuf (or chain of mbufs) containing the packet.
1228	@param protocol A zero or non-zero value.  A non-zero value specifies
1229		the transport protocol used for pseudo header checksum.
1230	@param offset A zero or non-zero value; if the latter, it specifies
1231		the offset of the transport header from the beginning of mbuf.
1232	@param length The total (non-zero) length of the transport segment.
1233	@param csum Pointer to the checksum variable; upon success, this
1234		routine will return the calculated Internet checksum through
1235		this variable.  The caller must set it to a non-NULL value.
1236	@result 0 upon success otherwise the errno error.
1237 */
1238extern errno_t mbuf_inet_cksum(mbuf_t mbuf, int protocol, u_int32_t offset,
1239    u_int32_t length, u_int16_t *csum);
1240
1241/*!
1242	@function mbuf_inet6_cksum
1243	@discussions Calculates 16-bit 1's complement Internet checksum of the
1244		transport segment with or without the pseudo header checksum
1245		of a given IPv6 packet.  If the caller specifies a non-zero
1246		transport protocol, the checksum returned will also include
1247		the pseudo header checksum for the corresponding transport
1248		header.  Otherwise, no header parsing will be done and the
1249		caller may use this to calculate the Internet checksum of
1250		an arbitrary span of data.
1251
1252		This routine does not modify the contents of the packet.  If
1253		the caller specifies a non-zero protocol and/or offset, the
1254		routine expects the complete protocol header(s) to be present
1255		at the beginning of the first mbuf.
1256	@param mbuf The mbuf (or chain of mbufs) containing the packet.
1257	@param protocol A zero or non-zero value.  A non-zero value specifies
1258		the transport protocol used for pseudo header checksum.
1259	@param offset A zero or non-zero value; if the latter, it specifies
1260		the offset of the transport header from the beginning of mbuf.
1261	@param length The total (non-zero) length of the transport segment.
1262	@param csum Pointer to the checksum variable; upon success, this
1263		routine will return the calculated Internet checksum through
1264		this variable.  The caller must set it to a non-NULL value.
1265	@result 0 upon success otherwise the errno error.
1266 */
1267extern errno_t mbuf_inet6_cksum(mbuf_t mbuf, int protocol, u_int32_t offset,
1268    u_int32_t length, u_int16_t *csum);
1269
1270/* mbuf tags */
1271
1272/*!
1273	@function mbuf_tag_id_find
1274	@discussion Lookup the module id for a string. If there is no module
1275		id assigned to this string, a new module id will be assigned.
1276		The string should be the bundle id of the kext. In the case of a
1277		tag that will be shared across multiple kexts, a common bundle
1278		id style string should be used.
1279
1280		The lookup operation is not optimized. A module should call this
1281		function once during startup and chache the module id. The
1282		module id will not be resassigned until the machine reboots.
1283	@param module_string A unique string identifying your module.
1284		Example: com.apple.nke.SharedIP.
1285	@param module_id Upon return, a unique identifier for use with
1286		mbuf_tag_* functions. This identifier is valid until the machine
1287		is rebooted.
1288	@result 0 upon success otherwise the errno error.
1289 */
1290extern errno_t mbuf_tag_id_find(const char *module_string,
1291    mbuf_tag_id_t *module_id);
1292
1293/*!
1294	@function mbuf_tag_allocate
1295	@discussion Allocate an mbuf tag. Mbuf tags allow various portions
1296		of the stack to tag mbufs with data that will travel with the
1297		mbuf through the stack.
1298
1299		Tags may only be added to mbufs with packet headers
1300		(MBUF_PKTHDR flag is set). Mbuf tags are freed when the mbuf is
1301		freed or when mbuf_tag_free is called.
1302	@param mbuf The mbuf to attach this tag to.
1303	@param module_id A module identifier returned by mbuf_tag_id_find.
1304	@param type A 16 bit type value. For a given module_id, you can use
1305		a number of different tag types.
1306	@param length The length, in bytes, to allocate for storage that
1307		will be associated with this tag on this mbuf.
1308	@param how Indicate whether you want to block and wait for memory if
1309		memory is not immediately available.
1310	@param data_p Upon successful return, *data_p will point to the
1311		buffer allocated for the mtag.
1312	@result 0 upon success otherwise the errno error.
1313 */
1314extern errno_t mbuf_tag_allocate(mbuf_t mbuf, mbuf_tag_id_t module_id,
1315    mbuf_tag_type_t type, size_t length, mbuf_how_t how, void **data_p);
1316
1317/*!
1318	@function mbuf_tag_find
1319	@discussion Find the data associated with an mbuf tag.
1320	@param mbuf The mbuf the tag is attached to.
1321	@param module_id A module identifier returned by mbuf_tag_id_find.
1322	@param type The 16 bit type of the tag to find.
1323	@param length Upon success, the length of data will be store in
1324		*length.
1325	@param data_p Upon successful return, *data_p will point to the
1326		buffer allocated for the mtag.
1327	@result 0 upon success otherwise the errno error.
1328 */
1329extern errno_t mbuf_tag_find(mbuf_t mbuf, mbuf_tag_id_t module_id,
1330    mbuf_tag_type_t type, size_t *length, void **data_p);
1331
1332/*!
1333	@function mbuf_tag_free
1334	@discussion Frees a previously allocated mbuf tag.
1335	@param mbuf The mbuf the tag was allocated on.
1336	@param module_id The ID of the tag to free.
1337	@param type The type of the tag to free.
1338 */
1339extern void mbuf_tag_free(mbuf_t mbuf, mbuf_tag_id_t module_id,
1340    mbuf_tag_type_t type);
1341
1342/* mbuf stats */
1343
1344/*!
1345	@function mbuf_stats
1346	@discussion Get the mbuf statistics.
1347	@param stats Storage to copy the stats in to.
1348 */
1349extern void mbuf_stats(struct mbuf_stat *stats);
1350
1351
1352/*!
1353	@enum mbuf_traffic_class_t
1354	@abstract Traffic class of a packet
1355	@discussion Property that represent the category of traffic of a packet.
1356		This information may be used by the driver and at the link level.
1357	@constant MBUF_TC_BE Best effort, normal class.
1358	@constant MBUF_TC_BK Background, low priority or bulk traffic.
1359	@constant MBUF_TC_VI Interactive video, constant bit rate, low latency.
1360	@constant MBUF_TC_VO Interactive voice, constant bit rate, lowest latency.
1361*/
1362typedef enum {
1363#ifdef XNU_KERNEL_PRIVATE
1364	MBUF_TC_UNSPEC	= -1,		/* Internal: not specified */
1365#endif
1366	MBUF_TC_BE		= 0,
1367	MBUF_TC_BK		= 1,
1368	MBUF_TC_VI		= 2,
1369	MBUF_TC_VO		= 3
1370#ifdef XNU_KERNEL_PRIVATE
1371        ,
1372	MBUF_TC_MAX		= 4	/* Internal: traffic class count */
1373#endif
1374} mbuf_traffic_class_t;
1375
1376/*!
1377	@function mbuf_get_traffic_class
1378	@discussion Get the traffic class of an mbuf packet
1379	@param mbuf The mbuf to get the traffic class of.
1380	@result The traffic class
1381*/
1382extern mbuf_traffic_class_t mbuf_get_traffic_class(mbuf_t mbuf);
1383
1384/*!
1385	@function mbuf_set_traffic_class
1386	@discussion Set the traffic class of an mbuf packet.
1387	@param mbuf The mbuf to set the traffic class on.
1388	@tc The traffic class
1389	@result 0 on success, EINVAL if bad paramater is passed
1390*/
1391extern errno_t mbuf_set_traffic_class(mbuf_t mbuf, mbuf_traffic_class_t tc);
1392
1393/*!
1394	@function mbuf_is_traffic_class_privileged
1395	@discussion Returns the privileged status of the traffic class
1396		of the packet specified by the mbuf.
1397	@param mbuf The mbuf to retrieve the status from.
1398	@result Non-zero if privileged, 0 otherwise.
1399 */
1400extern int mbuf_is_traffic_class_privileged(mbuf_t mbuf);
1401
1402#ifdef KERNEL_PRIVATE
1403/*!
1404	@enum mbuf_svc_class_t
1405	@abstract Service class of a packet
1406	@discussion Property that represents the category of service
1407		of a packet. This information may be used by the driver
1408		and at the link level.
1409	@constant MBUF_SC_BK_SYS "Background System-Initiated", high delay
1410		tolerant, high loss tolerant, elastic flow, variable size &
1411		long-lived.
1412	@constant MBUF_SC_BK "Background", user-initiated, high delay tolerant,
1413		high loss tolerant, elastic flow, variable size.  This level
1414		corresponds to WMM access class "BG", or MBUF_TC_BK.
1415	@constant MBUF_SC_BE "Best Effort", unclassified/standard.  This is
1416		the default service class; pretty much a mix of everything.
1417		This level corresponds to WMM access class "BE" or MBUF_TC_BE.
1418	@constant MBUF_SC_RD
1419		"Responsive Data", a notch higher than "Best Effort", medium
1420		delay tolerant, medium loss tolerant, elastic flow, bursty,
1421		long-lived.
1422	@constant MBUF_SC_OAM "Operations, Administration, and Management",
1423		medium delay tolerant, low-medium loss tolerant, elastic &
1424		inelastic flows, variable size.
1425	@constant MBUF_SC_AV "Multimedia Audio/Video Streaming", medium delay
1426		tolerant, low-medium loss tolerant, elastic flow, constant
1427		packet interval, variable rate & size.
1428	@constant MBUF_SC_RV "Responsive Multimedia Audio/Video", low delay
1429		tolerant, low-medium loss tolerant, elastic flow, variable
1430		packet interval, rate and size.
1431	@constant MBUF_SC_VI "Interactive Video", low delay tolerant, low-
1432		medium loss tolerant, elastic flow, constant packet interval,
1433		variable rate & size.  This level corresponds to WMM access
1434		class "VI" or MBUF_TC_VI.
1435	@constant MBUF_SC_VO "Interactive Voice", low delay tolerant, low loss
1436		tolerant, inelastic flow, constant packet rate, somewhat fixed
1437		size.  This level corresponds to WMM access class "VO" or
1438		MBUF_TC_VO.
1439	@constant MBUF_SC_CTL "Network Control", low delay tolerant, low loss
1440		tolerant, inelastic flow, rate is short & burst, variable size.
1441*/
1442typedef enum {
1443#ifdef XNU_KERNEL_PRIVATE
1444	MBUF_SC_UNSPEC		= -1,		/* Internal: not specified */
1445#endif
1446	MBUF_SC_BK_SYS		= 0x00080090,	/* lowest class */
1447	MBUF_SC_BK		= 0x00100080,
1448
1449	MBUF_SC_BE		= 0x00000000,
1450	MBUF_SC_RD		= 0x00180010,
1451	MBUF_SC_OAM		= 0x00200020,
1452
1453	MBUF_SC_AV		= 0x00280120,
1454	MBUF_SC_RV		= 0x00300110,
1455	MBUF_SC_VI		= 0x00380100,
1456
1457	MBUF_SC_VO		= 0x00400180,
1458	MBUF_SC_CTL		= 0x00480190,	/* highest class */
1459} mbuf_svc_class_t;
1460
1461/*!
1462	@function mbuf_get_service_class
1463	@discussion Get the service class of an mbuf packet
1464	@param mbuf The mbuf to get the service class of.
1465	@result The service class
1466*/
1467extern mbuf_svc_class_t mbuf_get_service_class(mbuf_t mbuf);
1468
1469/*!
1470	@function mbuf_set_servicec_class
1471	@discussion Set the service class of an mbuf packet.
1472	@param mbuf The mbuf to set the service class on.
1473	@sc The service class
1474	@result 0 on success, EINVAL if bad paramater is passed
1475*/
1476extern errno_t mbuf_set_service_class(mbuf_t mbuf, mbuf_svc_class_t sc);
1477
1478/*!
1479	@function mbuf_is_service_class_privileged
1480	@discussion Returns the privileged status of the service class
1481		of the packet specified by the mbuf.
1482	@param mbuf The mbuf to retrieve the status from.
1483	@result Non-zero if privileged, 0 otherwise.
1484 */
1485extern int mbuf_is_service_class_privileged(mbuf_t mbuf);
1486
1487/*
1488	@enum mbuf_pkthdr_aux_flags_t
1489	@abstract Constants defining mbuf auxiliary flags.  Only the flags
1490		listed below can be retrieved.
1491	@constant MBUF_PKTAUXF_INET_RESOLVE_RTR Indicates this is an ARP
1492		request packet, whose target is the address of the default
1493		IPv4 router.
1494	@constant MBUF_PKTAUXF_INET6_RESOLVE_RTR Indicates this is an ICMPv6
1495		Neighbor Solicitation packet, whose target is the address of
1496		the default IPv6 router.
1497 */
1498enum {
1499	MBUF_PKTAUXF_INET_RESOLVE_RTR	= 0x0004,
1500	MBUF_PKTAUXF_INET6_RESOLVE_RTR	= 0x0008,
1501};
1502typedef u_int32_t mbuf_pkthdr_aux_flags_t;
1503
1504/*
1505	@function mbuf_pkthdr_aux_flags
1506	@discussion Returns the auxiliary flags of a packet.
1507	@param mbuf The mbuf containing the packet header.
1508	@param paux_flags Pointer to mbuf_pkthdr_aux_flags_t variable.
1509	@result 0 upon success otherwise the errno error.
1510*/
1511extern errno_t mbuf_pkthdr_aux_flags(mbuf_t mbuf,
1512    mbuf_pkthdr_aux_flags_t *paux_flags);
1513#endif /* KERNEL_PRIVATE */
1514
1515/* IF_QUEUE interaction */
1516
1517#define IF_ENQUEUE_MBUF(ifq, m) {					\
1518	mbuf_setnextpkt((m), 0);					\
1519	if ((ifq)->ifq_tail == 0)					\
1520		(ifq)->ifq_head = (m);					\
1521	else								\
1522		mbuf_setnextpkt((mbuf_t)(ifq)->ifq_tail, (m));		\
1523	(ifq)->ifq_tail = (m);						\
1524	(ifq)->ifq_len++;						\
1525}
1526
1527#define	IF_PREPEND_MBUF(ifq, m) {					\
1528	mbuf_setnextpkt((m), (ifq)->ifq_head);				\
1529	if ((ifq)->ifq_tail == 0)					\
1530		(ifq)->ifq_tail = (m);					\
1531	(ifq)->ifq_head = (m);						\
1532	(ifq)->ifq_len++;						\
1533}
1534
1535#define	IF_DEQUEUE_MBUF(ifq, m) {					\
1536	(m) = (ifq)->ifq_head;						\
1537	if (m) {							\
1538		if (((ifq)->ifq_head = mbuf_nextpkt((m))) == 0)		\
1539			(ifq)->ifq_tail = 0;				\
1540		mbuf_setnextpkt((m), 0);				\
1541		(ifq)->ifq_len--;					\
1542	}								\
1543}
1544
1545__END_DECLS
1546#endif /* __KPI_MBUF__ */
1547