xref: /dflybsd-src/sys/sys/mbuf.h (revision f3adbb3cdddf061a5f284c3d9b33d22fecdfcfaf)
1 /*
2  * Copyright (c) 2004 The DragonFly Project.  All rights reserved.
3  *
4  * Copyright (c) 1982, 1986, 1988, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *	This product includes software developed by the University of
18  *	California, Berkeley and its contributors.
19  * 4. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  *
35  *	@(#)mbuf.h	8.5 (Berkeley) 2/19/95
36  * $FreeBSD: src/sys/sys/mbuf.h,v 1.44.2.17 2003/04/15 06:15:02 silby Exp $
37  * $DragonFly: src/sys/sys/mbuf.h,v 1.54 2008/10/19 08:39:55 sephe Exp $
38  */
39 
40 #ifndef _SYS_MBUF_H_
41 #define	_SYS_MBUF_H_
42 
43 #if defined(_KERNEL) || defined(_KERNEL_STRUCTURES)
44 
45 #ifndef _SYS_TYPES_H_
46 #include <sys/types.h>
47 #endif
48 #ifndef _SYS_PARAM_H_
49 #include <sys/param.h>
50 #endif
51 #ifndef _SYS_QUEUE_H_
52 #include <sys/queue.h>
53 #endif
54 #ifndef _NET_NETISR_H_
55 #include <net/netisr.h>
56 #endif
57 #ifndef _NET_ETHERNET_H_
58 #include <net/ethernet.h>
59 #endif
60 
61 /*
62  * Mbufs are of a single size, MSIZE (machine/param.h), which
63  * includes overhead.  An mbuf may add a single "mbuf cluster" of size
64  * MCLBYTES (also in machine/param.h), which has no additional overhead
65  * and is used instead of the internal data area; this is done when
66  * at least MINCLSIZE of data must be stored.
67  */
68 #define	MLEN		(MSIZE - sizeof(struct m_hdr))	/* normal data len */
69 #define	MHLEN		(MLEN - sizeof(struct pkthdr))	/* data len w/pkthdr */
70 #define	MINCLSIZE	(MHLEN + 1)	/* smallest amount to put in cluster */
71 #define	M_MAXCOMPRESS	(MHLEN / 2)	/* max amount to copy for compression */
72 
73 /*
74  * Macros for type conversion:
75  * mtod(m, t)		-- Convert mbuf pointer to data pointer of correct type.
76  * mtodoff(m, t, off)	-- Convert mbuf pointer at the specified offset to data
77  *			   pointer of correct type.
78  */
79 #define	mtod(m, t)		((t)((m)->m_data))
80 #define	mtodoff(m, t, off)	((t)((m)->m_data + (off)))
81 
82 /*
83  * Header present at the beginning of every mbuf.
84  */
85 struct m_hdr {
86 	struct	mbuf *mh_next;		/* next buffer in chain */
87 	struct	mbuf *mh_nextpkt;	/* next chain in queue/record */
88 	caddr_t	mh_data;		/* location of data */
89 	int	mh_len;			/* amount of data in this mbuf */
90 	int	mh_flags;		/* flags; see below */
91 	short	mh_type;		/* type of data in this mbuf */
92 	short	mh_pad;			/* padding */
93 #ifdef MBUF_DEBUG
94 	const char *mh_lastfunc;
95 #endif
96 	union {
97 		struct netmsg_packet mhm_pkt;	/* hardware->proto stack msg */
98 		struct netmsg_pru_send mhm_snd;	/* usrspace->proto stack msg */
99 	} mh_msgu;
100 };
101 #define mh_netmsg	mh_msgu.mhm_pkt
102 #define mh_sndmsg	mh_msgu.mhm_snd
103 
104 /* pf stuff */
105 struct pkthdr_pf {
106 	void            *hdr;           /* saved hdr pos in mbuf, for ECN */
107 	void		*statekey;	/* pf stackside statekey */
108 	u_int            rtableid;      /* alternate routing table id */
109 	u_int32_t        qid;           /* queue id */
110 	u_int16_t        tag;           /* tag id */
111 	u_int8_t         flags;
112 	u_int8_t         routed;
113 	uint32_t	state_hash;	/* identifies 'connections' */
114 	uint8_t		ecn_af;		/* for altq_red */
115 	uint8_t		unused01;
116 	uint8_t		unused02;
117 	uint8_t		unused03;
118 };
119 
120 /* pkthdr_pf.flags */
121 #define	PF_TAG_GENERATED		0x01
122 #define	PF_TAG_FRAGCACHE		0x02
123 #define	PF_TAG_TRANSLATE_LOCALHOST	0x04
124 #define	PF_TAG_DIVERTED			0x08
125 #define	PF_TAG_DIVERTED_PACKET		0x10
126 #define	PF_TAG_REROUTE			0x20
127 
128 /*
129  * Valid if BRIDGE_MBUF_TAGGED is set in fw_flags, records
130  * the original ether header (if compatible).  The bridge
131  */
132 struct pkthdr_br {
133 	struct ether_header ether;
134 };
135 
136 /*
137  * Packet tag structure (see below for details).
138  */
139 struct m_tag {
140 	SLIST_ENTRY(m_tag)	m_tag_link;	/* List of packet tags */
141 	u_int16_t		m_tag_id;	/* Tag ID */
142 	u_int16_t		m_tag_len;	/* Length of data */
143 	u_int32_t		m_tag_cookie;	/* ABI/Module ID */
144 };
145 
146 SLIST_HEAD(packet_tags, m_tag);
147 
148 /*
149  * Record/packet header in first mbuf of chain; valid only if M_PKTHDR is set.
150  *
151  * Be careful: The fields have been carefully ordered to avoid hidden padding.
152  *             Keep this in mind, when adding or removing fields!
153  */
154 struct pkthdr {
155 	struct	ifnet *rcvif;		/* rcv interface */
156 	int	len;			/* total packet length */
157 	struct packet_tags tags;	/* list of packet tags */
158 
159 	/* variables for ip and tcp reassembly */
160 	void	*header;		/* pointer to packet header */
161 
162 	/* variables for hardware checksum */
163 	int	csum_flags;		/* flags regarding checksum */
164 	int	csum_data;		/* data field used by csum routines */
165 	uint16_t csum_iphlen;		/* IP header length */
166 					/* valid if CSUM IP|UDP|TCP|TSO */
167 	uint8_t	csum_thlen;		/* TCP/UDP header length */
168 					/* valid if CSUM UDP|TCP|TSO */
169 	uint8_t	csum_lhlen;		/* link header length */
170 
171 	uint16_t tso_segsz;		/* TSO segment size */
172 	uint16_t ether_vlantag;		/* ethernet 802.1p+q vlan tag */
173 
174 	uint16_t hash;			/* packet hash */
175 	uint16_t wlan_seqno;		/* IEEE 802.11 seq no. */
176 
177 	/* firewall flags */
178 	uint32_t fw_flags;		/* flags for PF */
179 
180 	/* variables for PF processing */
181 	struct pkthdr_pf pf;		/* structure for PF */
182 	struct pkthdr_br br;		/* structure for bridging */
183 };
184 
185 /*
186  * Description of external storage mapped into mbuf; valid only if M_EXT is set.
187  */
188 struct m_ext {
189 	caddr_t	ext_buf;		/* start of buffer */
190 	void	(*ext_free)(void *);
191 	u_int	ext_size;		/* size of buffer, for ext_free */
192 	void	(*ext_ref)(void *);
193 	void	*ext_arg;
194 };
195 
196 /*
197  * The core of the mbuf object along with some shortcut defines for
198  * practical purposes.
199  */
200 struct mbuf {
201 	struct	m_hdr m_hdr;
202 	union {
203 		struct {
204 			struct	pkthdr MH_pkthdr;	/* M_PKTHDR set */
205 			union {
206 				struct	m_ext MH_ext;	/* M_EXT set */
207 				char	MH_databuf[MHLEN];
208 			} MH_dat;
209 		} MH;
210 		char	M_databuf[MLEN];		/* !M_PKTHDR, !M_EXT */
211 	} M_dat;
212 };
213 #define	m_next		m_hdr.mh_next
214 #define	m_len		m_hdr.mh_len
215 #define	m_data		m_hdr.mh_data
216 #define	m_type		m_hdr.mh_type
217 #define	m_flags		m_hdr.mh_flags
218 #define	m_nextpkt	m_hdr.mh_nextpkt
219 #define	m_pkthdr	M_dat.MH.MH_pkthdr
220 #define	m_ext		M_dat.MH.MH_dat.MH_ext
221 #define	m_pktdat	M_dat.MH.MH_dat.MH_databuf
222 #define	m_dat		M_dat.M_databuf
223 
224 /*
225  * Code that uses m_act should be converted to use m_nextpkt
226  * instead; m_act is historical and deprecated.
227  */
228 #define m_act   	m_nextpkt
229 
230 /*
231  * mbuf flags.
232  */
233 #define	M_EXT		0x0001	/* has associated external storage */
234 #define	M_PKTHDR	0x0002	/* start of record */
235 #define	M_EOR		0x0004	/* end of record */
236 #define	M_PROTO1	0x0008	/* protocol-specific */
237 #define	M_PROTO2	0x0010	/* protocol-specific */
238 #define	M_PROTO3	0x0020	/* protocol-specific */
239 #define	M_PROTO4	0x0040	/* protocol-specific */
240 #define	M_PROTO5	0x0080	/* protocol-specific */
241 
242 /*
243  * mbuf pkthdr flags (also stored in m_flags).
244  */
245 #define	M_BCAST		0x0100	/* send/received as link-level broadcast */
246 #define	M_MCAST		0x0200	/* send/received as link-level multicast */
247 #define	M_FRAG		0x0400	/* packet is a fragment of a larger packet */
248 #define	M_FIRSTFRAG	0x0800	/* packet is first fragment */
249 #define	M_LASTFRAG	0x1000	/* packet is last fragment */
250 #define	M_CLCACHE	0x2000	/* mbuf allocated from the cluster cache */
251 #define M_EXT_CLUSTER	0x4000	/* standard cluster else special */
252 #define	M_PHCACHE	0x8000	/* mbuf allocated from the pkt header cache */
253 #define M_NOTIFICATION	0x10000	/* notification event */
254 #define M_VLANTAG	0x20000	/* ether_vlantag is valid */
255 #define M_MPLSLABELED	0x40000	/* packet is mpls labeled */
256 #define M_LENCHECKED	0x80000	/* packet proto lengths are checked */
257 #define M_HASH		0x100000/* hash field in pkthdr is valid */
258 #define M_PROTO6        0x200000/* protocol-specific */
259 #define M_PROTO7        0x400000/* protocol-specific */
260 #define M_PROTO8        0x800000/* protocol-specific */
261 
262 /*
263  * Flags copied when copying m_pkthdr.
264  */
265 #define	M_COPYFLAGS	(M_PKTHDR|M_EOR|M_PROTO1|M_PROTO2|M_PROTO3 | \
266 			 M_PROTO4|M_PROTO5|M_PROTO6|M_PROTO7|M_PROTO8 | \
267 			 M_BCAST|M_MCAST|M_FRAG|M_FIRSTFRAG|M_LASTFRAG | \
268 			 M_VLANTAG|M_MPLSLABELED | \
269 			 M_LENCHECKED|M_HASH)
270 
271 /*
272  * Flags indicating hw checksum support and sw checksum requirements.
273  */
274 #define	CSUM_IP			0x0001		/* will csum IP */
275 #define	CSUM_TCP		0x0002		/* will csum TCP */
276 #define	CSUM_UDP		0x0004		/* will csum UDP */
277 #define	CSUM_IP_FRAGS		0x0008		/* will csum IP fragments */
278 #define	CSUM_FRAGMENT		0x0010		/* will do IP fragmentation */
279 
280 #define	CSUM_IP_CHECKED		0x0100		/* did csum IP */
281 #define	CSUM_IP_VALID		0x0200		/*   ... the csum is valid */
282 #define	CSUM_DATA_VALID		0x0400		/* csum_data field is valid */
283 #define	CSUM_PSEUDO_HDR		0x0800		/* csum_data has pseudo hdr */
284 #define CSUM_FRAG_NOT_CHECKED	0x1000		/* did _not_ csum fragment
285 						 * NB: This flag is only used
286 						 * by IP defragmenter.
287 						 */
288 #define CSUM_TSO		0x2000		/* will do TCP segmentation */
289 
290 #define	CSUM_DELAY_DATA		(CSUM_TCP | CSUM_UDP)
291 #define	CSUM_DELAY_IP		(CSUM_IP)	/* XXX add ipv6 here too? */
292 
293 /*
294  * Flags indicating PF processing status
295  */
296 #define FW_MBUF_GENERATED	0x00000001
297 #define	PF_MBUF_STRUCTURE	0x00000002	/* m_pkthdr.pf valid */
298 #define	PF_MBUF_ROUTED		0x00000004	/* pf_routed field is valid */
299 #define	PF_MBUF_TAGGED		0x00000008
300 #define	XX_MBUF_UNUSED10	0x00000010
301 #define	XX_MBUF_UNUSED20	0x00000020
302 #define IPFORWARD_MBUF_TAGGED	0x00000040
303 #define DUMMYNET_MBUF_TAGGED	0x00000080
304 #define BRIDGE_MBUF_TAGGED	0x00000100
305 #define FW_MBUF_REDISPATCH	0x00000200
306 #define	IPFW_MBUF_GENERATED	FW_MBUF_GENERATED
307 /*
308  * mbuf types.
309  */
310 #define	MT_FREE		0	/* should be on free list */
311 #define	MT_DATA		1	/* dynamic (data) allocation */
312 #define	MT_HEADER	2	/* packet header */
313 #define	MT_SONAME	3	/* socket name */
314 /* 4 was MT_TAG */
315 #define	MT_CONTROL	5	/* extra-data protocol message */
316 #define	MT_OOBDATA	6	/* expedited data  */
317 #define	MT_NTYPES	7	/* number of mbuf types for mbtypes[] */
318 
319 /*
320  * General mbuf allocator statistics structure.
321  */
322 struct mbstat {
323 	u_long	m_mbufs;	/* mbufs obtained from page pool */
324 	u_long	m_clusters;	/* clusters obtained from page pool */
325 	u_long	m_spare;	/* spare field */
326 	u_long	m_clfree;	/* free clusters */
327 	u_long	m_drops;	/* times failed to find space */
328 	u_long	m_wait;		/* times waited for space */
329 	u_long	m_drain;	/* times drained protocols for space */
330 	u_long	m_mcfail;	/* times m_copym failed */
331 	u_long	m_mpfail;	/* times m_pullup failed */
332 	u_long	m_msize;	/* length of an mbuf */
333 	u_long	m_mclbytes;	/* length of an mbuf cluster */
334 	u_long	m_mjumpagesize;	/* length of a jumbo mbuf cluster */
335 	u_long	m_minclsize;	/* min length of data to allocate a cluster */
336 	u_long	m_mlen;		/* length of data in an mbuf */
337 	u_long	m_mhlen;	/* length of data in a header mbuf */
338 };
339 
340 /*
341  * Flags specifying how an allocation should be made.
342  */
343 
344 #define	MB_DONTWAIT	0x4
345 #define	MB_TRYWAIT	0x8
346 #define	MB_WAIT		MB_TRYWAIT
347 
348 /*
349  * Mbuf to Malloc Flag Conversion.
350  */
351 #define	MBTOM(how)	((how) & MB_TRYWAIT ? M_WAITOK : M_NOWAIT)
352 
353 /*
354  * These are identifying numbers passed to the m_mballoc_wait function,
355  * allowing us to determine whether the call came from an MGETHDR or
356  * an MGET.
357  */
358 #define	MGETHDR_C      1
359 #define	MGET_C         2
360 
361 /*
362  * mbuf allocation/deallocation macros (YYY deprecated, too big):
363  *
364  *	MGET(struct mbuf *m, int how, int type)
365  * allocates an mbuf and initializes it to contain internal data.
366  *
367  *	MGETHDR(struct mbuf *m, int how, int type)
368  * allocates an mbuf and initializes it to contain a packet header
369  * and internal data.
370  */
371 #define	MGET(m, how, type) do {						\
372 	(m) = m_get((how), (type));					\
373 } while (0)
374 
375 #define	MGETHDR(m, how, type) do {					\
376 	(m) = m_gethdr((how), (type));					\
377 } while (0)
378 
379 /*
380  * MCLGET adds such clusters to a normal mbuf.  The flag M_EXT is set upon
381  * success.
382  * Deprecated.  Use m_getcl() or m_getl() instead.
383  */
384 #define	MCLGET(m, how) do {						\
385 	m_mclget((m), (how));						\
386 } while (0)
387 
388 /*
389  * NB: M_COPY_PKTHDR is deprecated; use either M_MOVE_PKTHDR
390  *     or m_dup_pkthdr.
391  */
392 /*
393  * Move mbuf pkthdr from "from" to "to".
394  * from should have M_PKTHDR set, and to must be empty.
395  * from no longer has a pkthdr after this operation.
396  */
397 #define	M_MOVE_PKTHDR(_to, _from)	m_move_pkthdr((_to), (_from))
398 
399 /*
400  * Set the m_data pointer of a newly-allocated mbuf (m_get/MGET) to place
401  * an object of the specified size at the end of the mbuf, longword aligned.
402  */
403 #define	M_ALIGN(m, len) do {						\
404 	(m)->m_data += (MLEN - (len)) & ~(sizeof(long) - 1);		\
405 } while (0)
406 
407 /*
408  * As above, for mbufs allocated with m_gethdr/MGETHDR
409  * or initialized by M_COPY_PKTHDR.
410  */
411 #define	MH_ALIGN(m, len) do {						\
412 	(m)->m_data += (MHLEN - (len)) & ~(sizeof(long) - 1);		\
413 } while (0)
414 
415 /*
416  * Check if we can write to an mbuf.
417  */
418 #define M_EXT_WRITABLE(m)	(m_sharecount(m) == 1)
419 #define M_WRITABLE(m)		(!((m)->m_flags & M_EXT) || M_EXT_WRITABLE(m))
420 
421 /*
422  * Check if the supplied mbuf has a packet header, or else panic.
423  */
424 #define	M_ASSERTPKTHDR(m)						\
425 	KASSERT(m != NULL && m->m_flags & M_PKTHDR,			\
426 		("%s: invalid mbuf or no mbuf packet header!", __func__))
427 
428 /*
429  * Compute the amount of space available before the current start of data.
430  * The M_EXT_WRITABLE() is a temporary, conservative safety measure: the burden
431  * of checking writability of the mbuf data area rests solely with the caller.
432  */
433 #define	M_LEADINGSPACE(m)						\
434 	((m)->m_flags & M_EXT ?						\
435 	    (M_EXT_WRITABLE(m) ? (m)->m_data - (m)->m_ext.ext_buf : 0):	\
436 	    (m)->m_flags & M_PKTHDR ? (m)->m_data - (m)->m_pktdat :	\
437 	    (m)->m_data - (m)->m_dat)
438 
439 /*
440  * Compute the amount of space available after the end of data in an mbuf.
441  * The M_WRITABLE() is a temporary, conservative safety measure: the burden
442  * of checking writability of the mbuf data area rests solely with the caller.
443  */
444 #define	M_TRAILINGSPACE(m)						\
445 	((m)->m_flags & M_EXT ?						\
446 	    (M_WRITABLE(m) ? (m)->m_ext.ext_buf + (m)->m_ext.ext_size	\
447 		- ((m)->m_data + (m)->m_len) : 0) :			\
448 	    &(m)->m_dat[MLEN] - ((m)->m_data + (m)->m_len))
449 
450 /*
451  * Arrange to prepend space of size plen to mbuf m.
452  * If a new mbuf must be allocated, how specifies whether to wait.
453  * If how is MB_DONTWAIT and allocation fails, the original mbuf chain
454  * is freed and m is set to NULL.
455  */
456 #define	M_PREPEND(m, plen, how) do {					\
457 	struct mbuf **_mmp = &(m);					\
458 	struct mbuf *_mm = *_mmp;					\
459 	int _mplen = (plen);						\
460 	int __mhow = (how);						\
461 									\
462 	if (M_LEADINGSPACE(_mm) >= _mplen) {				\
463 		_mm->m_data -= _mplen;					\
464 		_mm->m_len += _mplen;					\
465 	} else								\
466 		_mm = m_prepend(_mm, _mplen, __mhow);			\
467 	if (_mm != NULL && (_mm->m_flags & M_PKTHDR))			\
468 		_mm->m_pkthdr.len += _mplen;				\
469 	*_mmp = _mm;							\
470 } while (0)
471 
472 /* Length to m_copy to copy all. */
473 #define	M_COPYALL	1000000000
474 
475 /* Compatibility with 4.3 */
476 #define	m_copy(m, o, l)	m_copym((m), (o), (l), MB_DONTWAIT)
477 
478 #ifdef _KERNEL
479 extern	u_int		 m_clalloc_wid;	/* mbuf cluster wait count */
480 extern	u_int		 m_mballoc_wid;	/* mbuf wait count */
481 extern	int		 max_linkhdr;	/* largest link-level header */
482 extern	int		 max_protohdr;	/* largest protocol header */
483 extern	int		 max_hdr;	/* largest link+protocol header */
484 extern	int		 max_datalen;	/* MHLEN - max_hdr */
485 extern	int		 mbuf_wait;	/* mbuf sleep time */
486 extern	int		 nmbclusters;
487 extern	int		 nmbufs;
488 
489 struct uio;
490 
491 void		 m_adj(struct mbuf *, int);
492 void		 m_align(struct mbuf *, int);
493 int		 m_apply(struct mbuf *, int, int,
494 		    int (*)(void *, void *, u_int), void *);
495 int		m_append(struct mbuf *, int, c_caddr_t);
496 void		 m_cat(struct mbuf *, struct mbuf *);
497 u_int		 m_countm(struct mbuf *m, struct mbuf **lastm, u_int *mbcnt);
498 void		 m_copyback(struct mbuf *, int, int, caddr_t);
499 void		 m_copydata(const struct mbuf *, int, int, caddr_t);
500 struct	mbuf	*m_copym(const struct mbuf *, int, int, int);
501 struct	mbuf	*m_copypacket(struct mbuf *, int);
502 struct	mbuf	*m_defrag(struct mbuf *, int);
503 struct	mbuf	*m_defrag_nofree(struct mbuf *, int);
504 struct	mbuf	*m_devget(char *, int, int, struct ifnet *,
505 		  void (*copy)(volatile const void *, volatile void *, size_t));
506 struct	mbuf	*m_dup(struct mbuf *, int);
507 struct	mbuf	*m_dup_data(struct mbuf *, int);
508 int		 m_dup_pkthdr(struct mbuf *, const struct mbuf *, int);
509 void		 m_extadd(struct mbuf *, caddr_t, u_int, void (*)(void *),
510 		  void (*)(void *), void *);
511 #ifdef MBUF_DEBUG
512 struct	mbuf	*_m_free(struct mbuf *, const char *name);
513 void		 _m_freem(struct mbuf *, const char *name);
514 #else
515 struct	mbuf	*m_free(struct mbuf *);
516 void		 m_freem(struct mbuf *);
517 #endif
518 struct	mbuf	*m_get(int, int);
519 struct	mbuf	*m_getc(int len, int how, int type);
520 struct	mbuf	*m_getcl(int how, short type, int flags);
521 struct	mbuf	*m_getjcl(int how, short type, int flags, size_t size);
522 struct	mbuf	*m_getclr(int, int);
523 struct	mbuf	*m_gethdr(int, int);
524 struct	mbuf	*m_getm(struct mbuf *, int, int, int);
525 struct	mbuf	*m_getptr(struct mbuf *, int, int *);
526 struct	mbuf	*m_last(struct mbuf *m);
527 u_int		 m_lengthm(struct mbuf *m, struct mbuf **lastm);
528 void		 m_move_pkthdr(struct mbuf *, struct mbuf *);
529 struct	mbuf	*m_prepend(struct mbuf *, int, int);
530 void		 m_print(const struct mbuf *m);
531 struct	mbuf	*m_pulldown(struct mbuf *, int, int, int *);
532 struct	mbuf	*m_pullup(struct mbuf *, int);
533 struct	mbuf	*m_split(struct mbuf *, int, int);
534 struct	mbuf 	*m_uiomove(struct uio *);
535 struct	mbuf	*m_unshare(struct mbuf *, int);
536 void		m_mclget(struct mbuf *m, int how);
537 int		m_sharecount(struct mbuf *m);
538 void		m_chtype(struct mbuf *m, int type);
539 int		m_devpad(struct mbuf *m, int padto);
540 
541 #ifdef MBUF_DEBUG
542 
543 void		mbuftrackid(struct mbuf *, int);
544 
545 #define m_free(m)	_m_free(m, __func__)
546 #define m_freem(m)	_m_freem(m, __func__)
547 
548 #else
549 
550 #define mbuftrackid(m, id)	/* empty */
551 
552 #endif
553 
554 /*
555  * Allocate the right type of mbuf for the desired total length.
556  * The mbuf returned does not necessarily cover the entire requested length.
557  * This function follows mbuf chaining policy of allowing MINCLSIZE
558  * amount of chained mbufs.
559  */
560 static __inline struct mbuf *
561 m_getl(int len, int how, int type, int flags, int *psize)
562 {
563 	struct mbuf *m;
564 	int size;
565 
566 	if (len >= MINCLSIZE) {
567 		m = m_getcl(how, type, flags);
568 		size = MCLBYTES;
569 	} else if (flags & M_PKTHDR) {
570 		m = m_gethdr(how, type);
571 		size = MHLEN;
572 	} else {
573 		m = m_get(how, type);
574 		size = MLEN;
575 	}
576 	if (psize != NULL)
577 		*psize = size;
578 	return (m);
579 }
580 
581 /*
582  * Get a single mbuf that covers the requested number of bytes.
583  * This function does not create mbuf chains.  It explicitly marks
584  * places in the code that abuse mbufs for contiguous data buffers.
585  */
586 static __inline struct mbuf *
587 m_getb(int len, int how, int type, int flags)
588 {
589 	struct mbuf *m;
590 	int mbufsize = (flags & M_PKTHDR) ? MHLEN : MLEN;
591 
592 	if (len > mbufsize)
593 		m = m_getcl(how, type, flags);
594 	else if (flags & M_PKTHDR)
595 		m = m_gethdr(how, type);
596 	else
597 		m = m_get(how, type);
598 	return (m);
599 }
600 
601 /*
602  * Packets may have annotations attached by affixing a list
603  * of "packet tags" to the pkthdr structure.  Packet tags are
604  * dynamically allocated semi-opaque data structures that have
605  * a fixed header (struct m_tag) that specifies the size of the
606  * memory block and a <cookie,type> pair that identifies it.
607  * The cookie is a 32-bit unique unsigned value used to identify
608  * a module or ABI.  By convention this value is chose as the
609  * date+time that the module is created, expressed as the number of
610  * seconds since the epoch (e.g. using date -u +'%s').  The type value
611  * is an ABI/module-specific value that identifies a particular annotation
612  * and is private to the module.  For compatibility with systems
613  * like openbsd that define packet tags w/o an ABI/module cookie,
614  * the value PACKET_ABI_COMPAT is used to implement m_tag_get and
615  * m_tag_find compatibility shim functions and several tag types are
616  * defined below.  Users that do not require compatibility should use
617  * a private cookie value so that packet tag-related definitions
618  * can be maintained privately.
619  *
620  * Note that the packet tag returned by m_tag_alloc has the default
621  * memory alignment implemented by kmalloc.  To reference private data
622  * one can use a construct like:
623  *
624  *	struct m_tag *mtag = m_tag_alloc(...);
625  *	struct foo *p = m_tag_data(mtag);
626  *
627  * if the alignment of struct m_tag is sufficient for referencing members
628  * of struct foo.  Otherwise it is necessary to embed struct m_tag within
629  * the private data structure to insure proper alignment; e.g.
630  *
631  *	struct foo {
632  *		struct m_tag	tag;
633  *		...
634  *	};
635  *	struct foo *p = (struct foo *)m_tag_alloc(...);
636  *	struct m_tag *mtag = &p->tag;
637  */
638 
639 #define	PACKET_TAG_NONE				0  /* Nadda */
640 
641 /* Packet tag for use with PACKET_ABI_COMPAT */
642 #define	PACKET_TAG_IPSEC_IN_DONE		1  /* IPsec applied, in */
643 /* struct tdb_indent */
644 #define	PACKET_TAG_IPSEC_OUT_DONE		2  /* IPsec applied, out */
645 /* struct tdb_indent */
646 #define	PACKET_TAG_IPSEC_IN_CRYPTO_DONE		3  /* NIC IPsec crypto done */
647 /* struct tdb_indent, never added */
648 #define	PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED	4  /* NIC IPsec crypto req'ed */
649 /* struct tdb_indent, never added */
650 #define	PACKET_TAG_IPSEC_PENDING_TDB		5  /* Reminder to do IPsec */
651 /* struct tdb_indent, never added */
652 #define	PACKET_TAG_ENCAP			6 /* Encap.  processing */
653 /* struct ifnet *, the GIF interface */
654 #define	PACKET_TAG_IPSEC_HISTORY		7 /* IPSEC history */
655 /* struct ipsec_history */
656 #define	PACKET_TAG_IPV6_INPUT			8 /* IPV6 input processing */
657 /* struct ip6aux */
658 #define	PACKET_TAG_IPFW_DIVERT			9 /* divert info */
659 /* struct divert_info */
660 #define	PACKET_TAG_DUMMYNET			15 /* dummynet info */
661 /* struct dn_pkt */
662 #define	PACKET_TAG_IPFORWARD			18 /* ipforward info */
663 /* struct sockaddr_in */
664 #define PACKET_TAG_IPSRCRT			27 /* IP srcrt opts */
665 /* struct ip_srcrt_opt */
666 #define	PACKET_TAG_CARP                         28 /* CARP info */
667 /* struct pf_mtag */
668 #define PACKET_TAG_PF				29 /* PF info */
669 
670 #define PACKET_TAG_PF_DIVERT			0x0200 /* pf(4) diverted packet */
671 
672 
673 /* Packet tag routines */
674 struct	m_tag 	*m_tag_alloc(u_int32_t, int, int, int);
675 void		 m_tag_free(struct m_tag *);
676 void		 m_tag_prepend(struct mbuf *, struct m_tag *);
677 void		 m_tag_unlink(struct mbuf *, struct m_tag *);
678 void		 m_tag_delete(struct mbuf *, struct m_tag *);
679 void		 m_tag_delete_chain(struct mbuf *);
680 struct	m_tag	*m_tag_locate(struct mbuf *, u_int32_t, int, struct m_tag *);
681 struct	m_tag	*m_tag_copy(struct m_tag *, int);
682 int		 m_tag_copy_chain(struct mbuf *, const struct mbuf *, int);
683 void		 m_tag_init(struct mbuf *);
684 struct	m_tag	*m_tag_first(struct mbuf *);
685 struct	m_tag	*m_tag_next(struct mbuf *, struct m_tag *);
686 
687 /* these are for openbsd compatibility */
688 #define	MTAG_ABI_COMPAT		0		/* compatibility ABI */
689 
690 static __inline void *
691 m_tag_data(struct m_tag *tag)
692 {
693 	return ((void *)(tag + 1));
694 }
695 
696 static __inline struct m_tag *
697 m_tag_get(int type, int length, int wait)
698 {
699 	return m_tag_alloc(MTAG_ABI_COMPAT, type, length, wait);
700 }
701 
702 static __inline struct m_tag *
703 m_tag_find(struct mbuf *m, int type, struct m_tag *start)
704 {
705 	return m_tag_locate(m, MTAG_ABI_COMPAT, type, start);
706 }
707 
708 #endif	/* _KERNEL */
709 
710 #endif	/* _KERNEL || _KERNEL_STRUCTURES */
711 #endif	/* !_SYS_MBUF_H_ */
712