xref: /freebsd/sys/sys/mbuf.h (revision 145992504973bd16cf3518af9ba5ce185fefa82a)
1 /*-
2  * Copyright (c) 1982, 1986, 1988, 1993
3  *	The Regents of the University of California.
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 3. Neither the name of the University nor the names of its contributors
15  *    may be used to endorse or promote products derived from this software
16  *    without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  *
30  *	@(#)mbuf.h	8.5 (Berkeley) 2/19/95
31  * $FreeBSD$
32  */
33 
34 #ifndef _SYS_MBUF_H_
35 #define	_SYS_MBUF_H_
36 
37 /* XXX: These includes suck. Sorry! */
38 #include <sys/queue.h>
39 #ifdef _KERNEL
40 #include <sys/systm.h>
41 #include <vm/uma.h>
42 #ifdef WITNESS
43 #include <sys/lock.h>
44 #endif
45 #endif
46 
47 /*
48  * Mbufs are of a single size, MSIZE (sys/param.h), which includes overhead.
49  * An mbuf may add a single "mbuf cluster" of size MCLBYTES (also in
50  * sys/param.h), which has no additional overhead and is used instead of the
51  * internal data area; this is done when at least MINCLSIZE of data must be
52  * stored.  Additionally, it is possible to allocate a separate buffer
53  * externally and attach it to the mbuf in a way similar to that of mbuf
54  * clusters.
55  */
56 #define	MLEN		(MSIZE - sizeof(struct m_hdr))	/* normal data len */
57 #define	MHLEN		(MLEN - sizeof(struct pkthdr))	/* data len w/pkthdr */
58 #define	MINCLSIZE	(MHLEN + 1)	/* smallest amount to put in cluster */
59 #define	M_MAXCOMPRESS	(MHLEN / 2)	/* max amount to copy for compression */
60 
61 #ifdef _KERNEL
62 /*-
63  * Macro for type conversion: convert mbuf pointer to data pointer of correct
64  * type:
65  *
66  * mtod(m, t)	-- Convert mbuf pointer to data pointer of correct type.
67  */
68 #define	mtod(m, t)	((t)((m)->m_data))
69 
70 /*
71  * Argument structure passed to UMA routines during mbuf and packet
72  * allocations.
73  */
74 struct mb_args {
75 	int	flags;	/* Flags for mbuf being allocated */
76 	short	type;	/* Type of mbuf being allocated */
77 };
78 #endif /* _KERNEL */
79 
80 #if defined(__LP64__)
81 #define M_HDR_PAD    6
82 #else
83 #define M_HDR_PAD    2
84 #endif
85 
86 /*
87  * Header present at the beginning of every mbuf.
88  */
89 struct m_hdr {
90 	struct mbuf	*mh_next;	/* next buffer in chain */
91 	struct mbuf	*mh_nextpkt;	/* next chain in queue/record */
92 	caddr_t		 mh_data;	/* location of data */
93 	int		 mh_len;	/* amount of data in this mbuf */
94 	int		 mh_flags;	/* flags; see below */
95 	short		 mh_type;	/* type of data in this mbuf */
96 	uint8_t          pad[M_HDR_PAD];/* word align                  */
97 };
98 
99 /*
100  * Packet tag structure (see below for details).
101  */
102 struct m_tag {
103 	SLIST_ENTRY(m_tag)	m_tag_link;	/* List of packet tags */
104 	u_int16_t		m_tag_id;	/* Tag ID */
105 	u_int16_t		m_tag_len;	/* Length of data */
106 	u_int32_t		m_tag_cookie;	/* ABI/Module ID */
107 	void			(*m_tag_free)(struct m_tag *);
108 };
109 
110 /*
111  * Record/packet header in first mbuf of chain; valid only if M_PKTHDR is set.
112  */
113 struct pkthdr {
114 	struct ifnet	*rcvif;		/* rcv interface */
115 	/* variables for ip and tcp reassembly */
116 	void		*header;	/* pointer to packet header */
117 	int		 len;		/* total packet length */
118 	uint32_t	 flowid;	/* packet's 4-tuple system
119 					 * flow identifier
120 					 */
121 	/* variables for hardware checksum */
122 	int		 csum_flags;	/* flags regarding checksum */
123 	int		 csum_data;	/* data field used by csum routines */
124 	u_int16_t	 tso_segsz;	/* TSO segment size */
125 	union {
126 		u_int16_t vt_vtag;	/* Ethernet 802.1p+q vlan tag */
127 		u_int16_t vt_nrecs;	/* # of IGMPv3 records in this chain */
128 	} PH_vt;
129 	SLIST_HEAD(packet_tags, m_tag) tags; /* list of packet tags */
130 };
131 #define ether_vtag	PH_vt.vt_vtag
132 
133 /*
134  * Description of external storage mapped into mbuf; valid only if M_EXT is
135  * set.
136  */
137 struct m_ext {
138 	caddr_t		 ext_buf;	/* start of buffer */
139 	void		(*ext_free)	/* free routine if not the usual */
140 			    (void *, void *);
141 	void		*ext_arg1;	/* optional argument pointer */
142 	void		*ext_arg2;	/* optional argument pointer */
143 	u_int		 ext_size;	/* size of buffer, for ext_free */
144 	volatile u_int	*ref_cnt;	/* pointer to ref count info */
145 	int		 ext_type;	/* type of external storage */
146 };
147 
148 /*
149  * The core of the mbuf object along with some shortcut defines for practical
150  * purposes.
151  */
152 struct mbuf {
153 	struct m_hdr	m_hdr;
154 	union {
155 		struct {
156 			struct pkthdr	MH_pkthdr;	/* M_PKTHDR set */
157 			union {
158 				struct m_ext	MH_ext;	/* M_EXT set */
159 				char		MH_databuf[MHLEN];
160 			} MH_dat;
161 		} MH;
162 		char	M_databuf[MLEN];		/* !M_PKTHDR, !M_EXT */
163 	} M_dat;
164 };
165 #define	m_next		m_hdr.mh_next
166 #define	m_len		m_hdr.mh_len
167 #define	m_data		m_hdr.mh_data
168 #define	m_type		m_hdr.mh_type
169 #define	m_flags		m_hdr.mh_flags
170 #define	m_nextpkt	m_hdr.mh_nextpkt
171 #define	m_act		m_nextpkt
172 #define	m_pkthdr	M_dat.MH.MH_pkthdr
173 #define	m_ext		M_dat.MH.MH_dat.MH_ext
174 #define	m_pktdat	M_dat.MH.MH_dat.MH_databuf
175 #define	m_dat		M_dat.M_databuf
176 
177 /*
178  * mbuf flags.
179  */
180 #define	M_EXT		0x00000001 /* has associated external storage */
181 #define	M_PKTHDR	0x00000002 /* start of record */
182 #define	M_EOR		0x00000004 /* end of record */
183 #define	M_RDONLY	0x00000008 /* associated data is marked read-only */
184 #define	M_PROTO1	0x00000010 /* protocol-specific */
185 #define	M_PROTO2	0x00000020 /* protocol-specific */
186 #define	M_PROTO3	0x00000040 /* protocol-specific */
187 #define	M_PROTO4	0x00000080 /* protocol-specific */
188 #define	M_PROTO5	0x00000100 /* protocol-specific */
189 #define	M_BCAST		0x00000200 /* send/received as link-level broadcast */
190 #define	M_MCAST		0x00000400 /* send/received as link-level multicast */
191 #define	M_FRAG		0x00000800 /* packet is a fragment of a larger packet */
192 #define	M_FIRSTFRAG	0x00001000 /* packet is first fragment */
193 #define	M_LASTFRAG	0x00002000 /* packet is last fragment */
194 #define	M_SKIP_FIREWALL	0x00004000 /* skip firewall processing */
195 #define	M_FREELIST	0x00008000 /* mbuf is on the free list */
196 #define	M_VLANTAG	0x00010000 /* ether_vtag is valid */
197 #define	M_PROMISC	0x00020000 /* packet was not for us */
198 #define	M_NOFREE	0x00040000 /* do not free mbuf, embedded in cluster */
199 #define	M_PROTO6	0x00080000 /* protocol-specific */
200 #define	M_PROTO7	0x00100000 /* protocol-specific */
201 #define	M_PROTO8	0x00200000 /* protocol-specific */
202 #define	M_FLOWID	0x00400000 /* deprecated: flowid is valid */
203 #define	M_HASHTYPEBITS	0x0F000000 /* mask of bits holding flowid hash type */
204 
205 /*
206  * For RELENG_{6,7} steal these flags for limited multiple routing table
207  * support. In RELENG_8 and beyond, use just one flag and a tag.
208  */
209 #define	M_FIB		0xF0000000 /* steal some bits to store fib number. */
210 
211 #define	M_NOTIFICATION	M_PROTO5    /* SCTP notification */
212 
213 /*
214  * Flags to purge when crossing layers.
215  */
216 #define	M_PROTOFLAGS \
217     (M_PROTO1|M_PROTO2|M_PROTO3|M_PROTO4|M_PROTO5|M_PROTO6|M_PROTO7|M_PROTO8)
218 
219 /*
220  * Network interface cards are able to hash protocol fields (such as IPv4
221  * addresses and TCP port numbers) classify packets into flows.  These flows
222  * can then be used to maintain ordering while delivering packets to the OS
223  * via parallel input queues, as well as to provide a stateless affinity
224  * model.  NIC drivers can pass up the hash via m->m_pkthdr.flowid, and set
225  * m_flag fields to indicate how the hash should be interpreted by the
226  * network stack.
227  *
228  * Most NICs support RSS, which provides ordering and explicit affinity, and
229  * use the hash m_flag bits to indicate what header fields were covered by
230  * the hash.  M_HASHTYPE_OPAQUE can be set by non-RSS cards or configurations
231  * that provide an opaque flow identifier, allowing for ordering and
232  * distribution without explicit affinity.
233  */
234 #define	M_HASHTYPE_SHIFT		24
235 #define	M_HASHTYPE_NONE			0x0
236 #define	M_HASHTYPE_RSS_IPV4		0x1	/* IPv4 2-tuple */
237 #define	M_HASHTYPE_RSS_TCP_IPV4		0x2	/* TCPv4 4-tuple */
238 #define	M_HASHTYPE_RSS_IPV6		0x3	/* IPv6 2-tuple */
239 #define	M_HASHTYPE_RSS_TCP_IPV6		0x4	/* TCPv6 4-tuple */
240 #define	M_HASHTYPE_RSS_IPV6_EX		0x5	/* IPv6 2-tuple + ext hdrs */
241 #define	M_HASHTYPE_RSS_TCP_IPV6_EX	0x6	/* TCPv6 4-tiple + ext hdrs */
242 #define	M_HASHTYPE_OPAQUE		0xf	/* ordering, not affinity */
243 
244 #define	M_HASHTYPE_CLEAR(m)	(m)->m_flags &= ~(M_HASHTYPEBITS)
245 #define	M_HASHTYPE_GET(m)	(((m)->m_flags & M_HASHTYPEBITS) >> \
246 				    M_HASHTYPE_SHIFT)
247 #define	M_HASHTYPE_SET(m, v)	do {					\
248 	(m)->m_flags &= ~M_HASHTYPEBITS;				\
249 	(m)->m_flags |= ((v) << M_HASHTYPE_SHIFT);			\
250 } while (0)
251 #define	M_HASHTYPE_TEST(m, v)	(M_HASHTYPE_GET(m) == (v))
252 
253 /*
254  * Flags preserved when copying m_pkthdr.
255  */
256 #define	M_COPYFLAGS \
257     (M_PKTHDR|M_EOR|M_RDONLY|M_PROTOFLAGS|M_SKIP_FIREWALL|M_BCAST|M_MCAST|\
258      M_FRAG|M_FIRSTFRAG|M_LASTFRAG|M_VLANTAG|M_PROMISC|M_FIB|M_HASHTYPEBITS)
259 
260 /*
261  * External buffer types: identify ext_buf type.
262  */
263 #define	EXT_CLUSTER	1	/* mbuf cluster */
264 #define	EXT_SFBUF	2	/* sendfile(2)'s sf_bufs */
265 #define	EXT_JUMBOP	3	/* jumbo cluster 4096 bytes */
266 #define	EXT_JUMBO9	4	/* jumbo cluster 9216 bytes */
267 #define	EXT_JUMBO16	5	/* jumbo cluster 16184 bytes */
268 #define	EXT_PACKET	6	/* mbuf+cluster from packet zone */
269 #define	EXT_MBUF	7	/* external mbuf reference (M_IOVEC) */
270 #define	EXT_NET_DRV	100	/* custom ext_buf provided by net driver(s) */
271 #define	EXT_MOD_TYPE	200	/* custom module's ext_buf type */
272 #define	EXT_DISPOSABLE	300	/* can throw this buffer away w/page flipping */
273 #define	EXT_EXTREF	400	/* has externally maintained ref_cnt ptr */
274 
275 /*
276  * Flags indicating hw checksum support and sw checksum requirements.  This
277  * field can be directly tested against if_data.ifi_hwassist.
278  */
279 #define	CSUM_IP			0x0001		/* will csum IP */
280 #define	CSUM_TCP		0x0002		/* will csum TCP */
281 #define	CSUM_UDP		0x0004		/* will csum UDP */
282 #define	CSUM_IP_FRAGS		0x0008		/* will csum IP fragments */
283 #define	CSUM_FRAGMENT		0x0010		/* will do IP fragmentation */
284 #define	CSUM_TSO		0x0020		/* will do TSO */
285 #define	CSUM_SCTP		0x0040		/* will csum SCTP */
286 #define CSUM_SCTP_IPV6		0x0080		/* will csum IPv6/SCTP */
287 
288 #define	CSUM_IP_CHECKED		0x0100		/* did csum IP */
289 #define	CSUM_IP_VALID		0x0200		/*   ... the csum is valid */
290 #define	CSUM_DATA_VALID		0x0400		/* csum_data field is valid */
291 #define	CSUM_PSEUDO_HDR		0x0800		/* csum_data has pseudo hdr */
292 #define	CSUM_SCTP_VALID		0x1000		/* SCTP checksum is valid */
293 #define	CSUM_UDP_IPV6		0x2000		/* will csum IPv6/UDP */
294 #define	CSUM_TCP_IPV6		0x4000		/* will csum IPv6/TCP */
295 /*	CSUM_TSO_IPV6		0x8000		will do IPv6/TSO */
296 
297 /*	CSUM_FRAGMENT_IPV6	0x10000		will do IPv6 fragementation */
298 
299 #define	CSUM_DELAY_DATA_IPV6	(CSUM_TCP_IPV6 | CSUM_UDP_IPV6)
300 #define	CSUM_DATA_VALID_IPV6	CSUM_DATA_VALID
301 
302 #define	CSUM_DELAY_DATA		(CSUM_TCP | CSUM_UDP)
303 #define	CSUM_DELAY_IP		(CSUM_IP)	/* Only v4, no v6 IP hdr csum */
304 
305 /*
306  * mbuf types.
307  */
308 #define	MT_NOTMBUF	0	/* USED INTERNALLY ONLY! Object is not mbuf */
309 #define	MT_DATA		1	/* dynamic (data) allocation */
310 #define	MT_HEADER	MT_DATA	/* packet header, use M_PKTHDR instead */
311 #define	MT_SONAME	8	/* socket name */
312 #define	MT_CONTROL	14	/* extra-data protocol message */
313 #define	MT_OOBDATA	15	/* expedited data  */
314 #define	MT_NTYPES	16	/* number of mbuf types for mbtypes[] */
315 
316 #define	MT_NOINIT	255	/* Not a type but a flag to allocate
317 				   a non-initialized mbuf */
318 
319 #define MB_NOTAGS	0x1UL	/* no tags attached to mbuf */
320 
321 /*
322  * General mbuf allocator statistics structure.
323  *
324  * Many of these statistics are no longer used; we instead track many
325  * allocator statistics through UMA's built in statistics mechanism.
326  */
327 struct mbstat {
328 	u_long	m_mbufs;	/* XXX */
329 	u_long	m_mclusts;	/* XXX */
330 
331 	u_long	m_drain;	/* times drained protocols for space */
332 	u_long	m_mcfail;	/* XXX: times m_copym failed */
333 	u_long	m_mpfail;	/* XXX: times m_pullup failed */
334 	u_long	m_msize;	/* length of an mbuf */
335 	u_long	m_mclbytes;	/* length of an mbuf cluster */
336 	u_long	m_minclsize;	/* min length of data to allocate a cluster */
337 	u_long	m_mlen;		/* length of data in an mbuf */
338 	u_long	m_mhlen;	/* length of data in a header mbuf */
339 
340 	/* Number of mbtypes (gives # elems in mbtypes[] array) */
341 	short	m_numtypes;
342 
343 	/* XXX: Sendfile stats should eventually move to their own struct */
344 	u_long	sf_iocnt;	/* times sendfile had to do disk I/O */
345 	u_long	sf_allocfail;	/* times sfbuf allocation failed */
346 	u_long	sf_allocwait;	/* times sfbuf allocation had to wait */
347 };
348 
349 /*
350  * Flags specifying how an allocation should be made.
351  *
352  * The flag to use is as follows:
353  * - M_DONTWAIT or M_NOWAIT from an interrupt handler to not block allocation.
354  * - M_WAIT or M_WAITOK from wherever it is safe to block.
355  *
356  * M_DONTWAIT/M_NOWAIT means that we will not block the thread explicitly and
357  * if we cannot allocate immediately we may return NULL, whereas
358  * M_WAIT/M_WAITOK means that if we cannot allocate resources we
359  * will block until they are available, and thus never return NULL.
360  *
361  * XXX Eventually just phase this out to use M_WAITOK/M_NOWAIT.
362  */
363 #define	MBTOM(how)	(how)
364 #define	M_DONTWAIT	M_NOWAIT
365 #define	M_TRYWAIT	M_WAITOK
366 #define	M_WAIT		M_WAITOK
367 
368 /*
369  * String names of mbuf-related UMA(9) and malloc(9) types.  Exposed to
370  * !_KERNEL so that monitoring tools can look up the zones with
371  * libmemstat(3).
372  */
373 #define	MBUF_MEM_NAME		"mbuf"
374 #define	MBUF_CLUSTER_MEM_NAME	"mbuf_cluster"
375 #define	MBUF_PACKET_MEM_NAME	"mbuf_packet"
376 #define	MBUF_JUMBOP_MEM_NAME	"mbuf_jumbo_page"
377 #define	MBUF_JUMBO9_MEM_NAME	"mbuf_jumbo_9k"
378 #define	MBUF_JUMBO16_MEM_NAME	"mbuf_jumbo_16k"
379 #define	MBUF_TAG_MEM_NAME	"mbuf_tag"
380 #define	MBUF_EXTREFCNT_MEM_NAME	"mbuf_ext_refcnt"
381 
382 #ifdef _KERNEL
383 
384 #ifdef WITNESS
385 #define	MBUF_CHECKSLEEP(how) do {					\
386 	if (how == M_WAITOK)						\
387 		WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,		\
388 		    "Sleeping in \"%s\"", __func__);			\
389 } while (0)
390 #else
391 #define	MBUF_CHECKSLEEP(how)
392 #endif
393 
394 /*
395  * Network buffer allocation API
396  *
397  * The rest of it is defined in kern/kern_mbuf.c
398  */
399 
400 extern uma_zone_t	zone_mbuf;
401 extern uma_zone_t	zone_clust;
402 extern uma_zone_t	zone_pack;
403 extern uma_zone_t	zone_jumbop;
404 extern uma_zone_t	zone_jumbo9;
405 extern uma_zone_t	zone_jumbo16;
406 extern uma_zone_t	zone_ext_refcnt;
407 
408 static __inline struct mbuf	*m_getcl(int how, short type, int flags);
409 static __inline struct mbuf	*m_get(int how, short type);
410 static __inline struct mbuf	*m_get2(int how, short type, int flags,
411 				    int size);
412 static __inline struct mbuf	*m_gethdr(int how, short type);
413 static __inline struct mbuf	*m_getjcl(int how, short type, int flags,
414 				    int size);
415 static __inline struct mbuf	*m_getclr(int how, short type);	/* XXX */
416 static __inline int		 m_init(struct mbuf *m, uma_zone_t zone,
417 				    int size, int how, short type, int flags);
418 static __inline struct mbuf	*m_free(struct mbuf *m);
419 static __inline void		 m_clget(struct mbuf *m, int how);
420 static __inline void		*m_cljget(struct mbuf *m, int how, int size);
421 static __inline void		 m_chtype(struct mbuf *m, short new_type);
422 void				 mb_free_ext(struct mbuf *);
423 static __inline struct mbuf	*m_last(struct mbuf *m);
424 int				 m_pkthdr_init(struct mbuf *m, int how);
425 
426 static __inline int
427 m_gettype(int size)
428 {
429 	int type;
430 
431 	switch (size) {
432 	case MSIZE:
433 		type = EXT_MBUF;
434 		break;
435 	case MCLBYTES:
436 		type = EXT_CLUSTER;
437 		break;
438 #if MJUMPAGESIZE != MCLBYTES
439 	case MJUMPAGESIZE:
440 		type = EXT_JUMBOP;
441 		break;
442 #endif
443 	case MJUM9BYTES:
444 		type = EXT_JUMBO9;
445 		break;
446 	case MJUM16BYTES:
447 		type = EXT_JUMBO16;
448 		break;
449 	default:
450 		panic("%s: invalid cluster size", __func__);
451 	}
452 
453 	return (type);
454 }
455 
456 static __inline uma_zone_t
457 m_getzone(int size)
458 {
459 	uma_zone_t zone;
460 
461 	switch (size) {
462 	case MCLBYTES:
463 		zone = zone_clust;
464 		break;
465 #if MJUMPAGESIZE != MCLBYTES
466 	case MJUMPAGESIZE:
467 		zone = zone_jumbop;
468 		break;
469 #endif
470 	case MJUM9BYTES:
471 		zone = zone_jumbo9;
472 		break;
473 	case MJUM16BYTES:
474 		zone = zone_jumbo16;
475 		break;
476 	default:
477 		panic("%s: invalid cluster size", __func__);
478 	}
479 
480 	return (zone);
481 }
482 
483 /*
484  * Initialize an mbuf with linear storage.
485  *
486  * Inline because the consumer text overhead will be roughly the same to
487  * initialize or call a function with this many parameters and M_PKTHDR
488  * should go away with constant propagation for !MGETHDR.
489  */
490 static __inline int
491 m_init(struct mbuf *m, uma_zone_t zone, int size, int how, short type,
492     int flags)
493 {
494 	int error;
495 
496 	m->m_next = NULL;
497 	m->m_nextpkt = NULL;
498 	m->m_data = m->m_dat;
499 	m->m_len = 0;
500 	m->m_flags = flags;
501 	m->m_type = type;
502 	if (flags & M_PKTHDR) {
503 		if ((error = m_pkthdr_init(m, how)) != 0)
504 			return (error);
505 	}
506 
507 	return (0);
508 }
509 
510 static __inline struct mbuf *
511 m_get(int how, short type)
512 {
513 	struct mb_args args;
514 
515 	args.flags = 0;
516 	args.type = type;
517 	return ((struct mbuf *)(uma_zalloc_arg(zone_mbuf, &args, how)));
518 }
519 
520 /*
521  * XXX This should be deprecated, very little use.
522  */
523 static __inline struct mbuf *
524 m_getclr(int how, short type)
525 {
526 	struct mbuf *m;
527 	struct mb_args args;
528 
529 	args.flags = 0;
530 	args.type = type;
531 	m = uma_zalloc_arg(zone_mbuf, &args, how);
532 	if (m != NULL)
533 		bzero(m->m_data, MLEN);
534 	return (m);
535 }
536 
537 static __inline struct mbuf *
538 m_gethdr(int how, short type)
539 {
540 	struct mb_args args;
541 
542 	args.flags = M_PKTHDR;
543 	args.type = type;
544 	return ((struct mbuf *)(uma_zalloc_arg(zone_mbuf, &args, how)));
545 }
546 
547 static __inline struct mbuf *
548 m_getcl(int how, short type, int flags)
549 {
550 	struct mb_args args;
551 
552 	args.flags = flags;
553 	args.type = type;
554 	return ((struct mbuf *)(uma_zalloc_arg(zone_pack, &args, how)));
555 }
556 
557 /*
558  * m_get2() allocates minimum mbuf that would fit "size" argument.
559  *
560  * XXX: This is rather large, should be real function maybe.
561  */
562 static __inline struct mbuf *
563 m_get2(int how, short type, int flags, int size)
564 {
565 	struct mb_args args;
566 	struct mbuf *m, *n;
567 	uma_zone_t zone;
568 
569 	args.flags = flags;
570 	args.type = type;
571 
572 	if (size <= MHLEN || (size <= MLEN && (flags & M_PKTHDR) == 0))
573 		return ((struct mbuf *)(uma_zalloc_arg(zone_mbuf, &args, how)));
574 	if (size <= MCLBYTES)
575 		return ((struct mbuf *)(uma_zalloc_arg(zone_pack, &args, how)));
576 
577 	if (size > MJUM16BYTES)
578 		return (NULL);
579 
580 	m = uma_zalloc_arg(zone_mbuf, &args, how);
581 	if (m == NULL)
582 		return (NULL);
583 
584 #if MJUMPAGESIZE != MCLBYTES
585 	if (size <= MJUMPAGESIZE)
586 		zone = zone_jumbop;
587 	else
588 #endif
589 	if (size <= MJUM9BYTES)
590 		zone = zone_jumbo9;
591 	else
592 		zone = zone_jumbo16;
593 
594 	n = uma_zalloc_arg(zone, m, how);
595 	if (n == NULL) {
596 		uma_zfree(zone_mbuf, m);
597 		return (NULL);
598 	}
599 
600 	return (m);
601 }
602 
603 /*
604  * m_getjcl() returns an mbuf with a cluster of the specified size attached.
605  * For size it takes MCLBYTES, MJUMPAGESIZE, MJUM9BYTES, MJUM16BYTES.
606  *
607  * XXX: This is rather large, should be real function maybe.
608  */
609 static __inline struct mbuf *
610 m_getjcl(int how, short type, int flags, int size)
611 {
612 	struct mb_args args;
613 	struct mbuf *m, *n;
614 	uma_zone_t zone;
615 
616 	if (size == MCLBYTES)
617 		return m_getcl(how, type, flags);
618 
619 	args.flags = flags;
620 	args.type = type;
621 
622 	m = uma_zalloc_arg(zone_mbuf, &args, how);
623 	if (m == NULL)
624 		return (NULL);
625 
626 	zone = m_getzone(size);
627 	n = uma_zalloc_arg(zone, m, how);
628 	if (n == NULL) {
629 		uma_zfree(zone_mbuf, m);
630 		return (NULL);
631 	}
632 	return (m);
633 }
634 
635 static __inline void
636 m_free_fast(struct mbuf *m)
637 {
638 #ifdef INVARIANTS
639 	if (m->m_flags & M_PKTHDR)
640 		KASSERT(SLIST_EMPTY(&m->m_pkthdr.tags), ("doing fast free of mbuf with tags"));
641 #endif
642 
643 	uma_zfree_arg(zone_mbuf, m, (void *)MB_NOTAGS);
644 }
645 
646 static __inline struct mbuf *
647 m_free(struct mbuf *m)
648 {
649 	struct mbuf *n = m->m_next;
650 
651 	if (m->m_flags & M_EXT)
652 		mb_free_ext(m);
653 	else if ((m->m_flags & M_NOFREE) == 0)
654 		uma_zfree(zone_mbuf, m);
655 	return (n);
656 }
657 
658 static __inline void
659 m_clget(struct mbuf *m, int how)
660 {
661 
662 	if (m->m_flags & M_EXT)
663 		printf("%s: %p mbuf already has cluster\n", __func__, m);
664 	m->m_ext.ext_buf = (char *)NULL;
665 	uma_zalloc_arg(zone_clust, m, how);
666 	/*
667 	 * On a cluster allocation failure, drain the packet zone and retry,
668 	 * we might be able to loosen a few clusters up on the drain.
669 	 */
670 	if ((how & M_NOWAIT) && (m->m_ext.ext_buf == NULL)) {
671 		zone_drain(zone_pack);
672 		uma_zalloc_arg(zone_clust, m, how);
673 	}
674 }
675 
676 /*
677  * m_cljget() is different from m_clget() as it can allocate clusters without
678  * attaching them to an mbuf.  In that case the return value is the pointer
679  * to the cluster of the requested size.  If an mbuf was specified, it gets
680  * the cluster attached to it and the return value can be safely ignored.
681  * For size it takes MCLBYTES, MJUMPAGESIZE, MJUM9BYTES, MJUM16BYTES.
682  */
683 static __inline void *
684 m_cljget(struct mbuf *m, int how, int size)
685 {
686 	uma_zone_t zone;
687 
688 	if (m && m->m_flags & M_EXT)
689 		printf("%s: %p mbuf already has cluster\n", __func__, m);
690 	if (m != NULL)
691 		m->m_ext.ext_buf = NULL;
692 
693 	zone = m_getzone(size);
694 	return (uma_zalloc_arg(zone, m, how));
695 }
696 
697 static __inline void
698 m_cljset(struct mbuf *m, void *cl, int type)
699 {
700 	uma_zone_t zone;
701 	int size;
702 
703 	switch (type) {
704 	case EXT_CLUSTER:
705 		size = MCLBYTES;
706 		zone = zone_clust;
707 		break;
708 #if MJUMPAGESIZE != MCLBYTES
709 	case EXT_JUMBOP:
710 		size = MJUMPAGESIZE;
711 		zone = zone_jumbop;
712 		break;
713 #endif
714 	case EXT_JUMBO9:
715 		size = MJUM9BYTES;
716 		zone = zone_jumbo9;
717 		break;
718 	case EXT_JUMBO16:
719 		size = MJUM16BYTES;
720 		zone = zone_jumbo16;
721 		break;
722 	default:
723 		panic("%s: unknown cluster type", __func__);
724 		break;
725 	}
726 
727 	m->m_data = m->m_ext.ext_buf = cl;
728 	m->m_ext.ext_free = m->m_ext.ext_arg1 = m->m_ext.ext_arg2 = NULL;
729 	m->m_ext.ext_size = size;
730 	m->m_ext.ext_type = type;
731 	m->m_ext.ref_cnt = uma_find_refcnt(zone, cl);
732 	m->m_flags |= M_EXT;
733 
734 }
735 
736 static __inline void
737 m_chtype(struct mbuf *m, short new_type)
738 {
739 
740 	m->m_type = new_type;
741 }
742 
743 static __inline struct mbuf *
744 m_last(struct mbuf *m)
745 {
746 
747 	while (m->m_next)
748 		m = m->m_next;
749 	return (m);
750 }
751 
752 /*
753  * mbuf, cluster, and external object allocation macros (for compatibility
754  * purposes).
755  */
756 #define	M_MOVE_PKTHDR(to, from)	m_move_pkthdr((to), (from))
757 #define	MGET(m, how, type)	((m) = m_get((how), (type)))
758 #define	MGETHDR(m, how, type)	((m) = m_gethdr((how), (type)))
759 #define	MCLGET(m, how)		m_clget((m), (how))
760 #define	MEXTADD(m, buf, size, free, arg1, arg2, flags, type)		\
761     m_extadd((m), (caddr_t)(buf), (size), (free),(arg1),(arg2),(flags), (type))
762 #define	m_getm(m, len, how, type)					\
763     m_getm2((m), (len), (how), (type), M_PKTHDR)
764 
765 /*
766  * Evaluate TRUE if it's safe to write to the mbuf m's data region (this can
767  * be both the local data payload, or an external buffer area, depending on
768  * whether M_EXT is set).
769  */
770 #define	M_WRITABLE(m)	(!((m)->m_flags & M_RDONLY) &&			\
771 			 (!(((m)->m_flags & M_EXT)) ||			\
772 			 (*((m)->m_ext.ref_cnt) == 1)) )		\
773 
774 /* Check if the supplied mbuf has a packet header, or else panic. */
775 #define	M_ASSERTPKTHDR(m)						\
776 	KASSERT((m) != NULL && (m)->m_flags & M_PKTHDR,			\
777 	    ("%s: no mbuf packet header!", __func__))
778 
779 /*
780  * Ensure that the supplied mbuf is a valid, non-free mbuf.
781  *
782  * XXX: Broken at the moment.  Need some UMA magic to make it work again.
783  */
784 #define	M_ASSERTVALID(m)						\
785 	KASSERT((((struct mbuf *)m)->m_flags & 0) == 0,			\
786 	    ("%s: attempted use of a free mbuf!", __func__))
787 
788 /*
789  * Set the m_data pointer of a newly-allocated mbuf (m_get/MGET) to place an
790  * object of the specified size at the end of the mbuf, longword aligned.
791  */
792 #define	M_ALIGN(m, len) do {						\
793 	KASSERT(!((m)->m_flags & (M_PKTHDR|M_EXT)),			\
794 		("%s: M_ALIGN not normal mbuf", __func__));		\
795 	KASSERT((m)->m_data == (m)->m_dat,				\
796 		("%s: M_ALIGN not a virgin mbuf", __func__));		\
797 	(m)->m_data += (MLEN - (len)) & ~(sizeof(long) - 1);		\
798 } while (0)
799 
800 /*
801  * As above, for mbufs allocated with m_gethdr/MGETHDR or initialized by
802  * M_DUP/MOVE_PKTHDR.
803  */
804 #define	MH_ALIGN(m, len) do {						\
805 	KASSERT((m)->m_flags & M_PKTHDR && !((m)->m_flags & M_EXT),	\
806 		("%s: MH_ALIGN not PKTHDR mbuf", __func__));		\
807 	KASSERT((m)->m_data == (m)->m_pktdat,				\
808 		("%s: MH_ALIGN not a virgin mbuf", __func__));		\
809 	(m)->m_data += (MHLEN - (len)) & ~(sizeof(long) - 1);		\
810 } while (0)
811 
812 /*
813  * Compute the amount of space available before the current start of data in
814  * an mbuf.
815  *
816  * The M_WRITABLE() is a temporary, conservative safety measure: the burden
817  * of checking writability of the mbuf data area rests solely with the caller.
818  */
819 #define	M_LEADINGSPACE(m)						\
820 	((m)->m_flags & M_EXT ?						\
821 	    (M_WRITABLE(m) ? (m)->m_data - (m)->m_ext.ext_buf : 0):	\
822 	    (m)->m_flags & M_PKTHDR ? (m)->m_data - (m)->m_pktdat :	\
823 	    (m)->m_data - (m)->m_dat)
824 
825 /*
826  * Compute the amount of space available after the end of data in an mbuf.
827  *
828  * The M_WRITABLE() is a temporary, conservative safety measure: the burden
829  * of checking writability of the mbuf data area rests solely with the caller.
830  */
831 #define	M_TRAILINGSPACE(m)						\
832 	((m)->m_flags & M_EXT ?						\
833 	    (M_WRITABLE(m) ? (m)->m_ext.ext_buf + (m)->m_ext.ext_size	\
834 		- ((m)->m_data + (m)->m_len) : 0) :			\
835 	    &(m)->m_dat[MLEN] - ((m)->m_data + (m)->m_len))
836 
837 /*
838  * Arrange to prepend space of size plen to mbuf m.  If a new mbuf must be
839  * allocated, how specifies whether to wait.  If the allocation fails, the
840  * original mbuf chain is freed and m is set to NULL.
841  */
842 #define	M_PREPEND(m, plen, how) do {					\
843 	struct mbuf **_mmp = &(m);					\
844 	struct mbuf *_mm = *_mmp;					\
845 	int _mplen = (plen);						\
846 	int __mhow = (how);						\
847 									\
848 	MBUF_CHECKSLEEP(how);						\
849 	if (M_LEADINGSPACE(_mm) >= _mplen) {				\
850 		_mm->m_data -= _mplen;					\
851 		_mm->m_len += _mplen;					\
852 	} else								\
853 		_mm = m_prepend(_mm, _mplen, __mhow);			\
854 	if (_mm != NULL && _mm->m_flags & M_PKTHDR)			\
855 		_mm->m_pkthdr.len += _mplen;				\
856 	*_mmp = _mm;							\
857 } while (0)
858 
859 /*
860  * Change mbuf to new type.  This is a relatively expensive operation and
861  * should be avoided.
862  */
863 #define	MCHTYPE(m, t)	m_chtype((m), (t))
864 
865 /* Length to m_copy to copy all. */
866 #define	M_COPYALL	1000000000
867 
868 /* Compatibility with 4.3. */
869 #define	m_copy(m, o, l)	m_copym((m), (o), (l), M_DONTWAIT)
870 
871 extern int		max_datalen;	/* MHLEN - max_hdr */
872 extern int		max_hdr;	/* Largest link + protocol header */
873 extern int		max_linkhdr;	/* Largest link-level header */
874 extern int		max_protohdr;	/* Largest protocol header */
875 extern struct mbstat	mbstat;		/* General mbuf stats/infos */
876 extern int		nmbclusters;	/* Maximum number of clusters */
877 
878 struct uio;
879 
880 void		 m_adj(struct mbuf *, int);
881 void		 m_align(struct mbuf *, int);
882 int		 m_apply(struct mbuf *, int, int,
883 		    int (*)(void *, void *, u_int), void *);
884 int		 m_append(struct mbuf *, int, c_caddr_t);
885 void		 m_cat(struct mbuf *, struct mbuf *);
886 void		 m_extadd(struct mbuf *, caddr_t, u_int,
887 		    void (*)(void *, void *), void *, void *, int, int);
888 struct mbuf	*m_collapse(struct mbuf *, int, int);
889 void		 m_copyback(struct mbuf *, int, int, c_caddr_t);
890 void		 m_copydata(const struct mbuf *, int, int, caddr_t);
891 struct mbuf	*m_copym(struct mbuf *, int, int, int);
892 struct mbuf	*m_copymdata(struct mbuf *, struct mbuf *,
893 		    int, int, int, int);
894 struct mbuf	*m_copypacket(struct mbuf *, int);
895 void		 m_copy_pkthdr(struct mbuf *, struct mbuf *);
896 struct mbuf	*m_copyup(struct mbuf *n, int len, int dstoff);
897 struct mbuf	*m_defrag(struct mbuf *, int);
898 void		 m_demote(struct mbuf *, int);
899 struct mbuf	*m_devget(char *, int, int, struct ifnet *,
900 		    void (*)(char *, caddr_t, u_int));
901 struct mbuf	*m_dup(struct mbuf *, int);
902 int		 m_dup_pkthdr(struct mbuf *, struct mbuf *, int);
903 u_int		 m_fixhdr(struct mbuf *);
904 struct mbuf	*m_fragment(struct mbuf *, int, int);
905 void		 m_freem(struct mbuf *);
906 struct mbuf	*m_getm2(struct mbuf *, int, int, short, int);
907 struct mbuf	*m_getptr(struct mbuf *, int, int *);
908 u_int		 m_length(struct mbuf *, struct mbuf **);
909 int		 m_mbuftouio(struct uio *, struct mbuf *, int);
910 void		 m_move_pkthdr(struct mbuf *, struct mbuf *);
911 struct mbuf	*m_prepend(struct mbuf *, int, int);
912 void		 m_print(const struct mbuf *, int);
913 struct mbuf	*m_pulldown(struct mbuf *, int, int, int *);
914 struct mbuf	*m_pullup(struct mbuf *, int);
915 int		m_sanity(struct mbuf *, int);
916 struct mbuf	*m_split(struct mbuf *, int, int);
917 struct mbuf	*m_uiotombuf(struct uio *, int, int, int, int);
918 struct mbuf	*m_unshare(struct mbuf *, int how);
919 
920 /*-
921  * Network packets may have annotations attached by affixing a list of
922  * "packet tags" to the pkthdr structure.  Packet tags are dynamically
923  * allocated semi-opaque data structures that have a fixed header
924  * (struct m_tag) that specifies the size of the memory block and a
925  * <cookie,type> pair that identifies it.  The cookie is a 32-bit unique
926  * unsigned value used to identify a module or ABI.  By convention this value
927  * is chosen as the date+time that the module is created, expressed as the
928  * number of seconds since the epoch (e.g., using date -u +'%s').  The type
929  * value is an ABI/module-specific value that identifies a particular
930  * annotation and is private to the module.  For compatibility with systems
931  * like OpenBSD that define packet tags w/o an ABI/module cookie, the value
932  * PACKET_ABI_COMPAT is used to implement m_tag_get and m_tag_find
933  * compatibility shim functions and several tag types are defined below.
934  * Users that do not require compatibility should use a private cookie value
935  * so that packet tag-related definitions can be maintained privately.
936  *
937  * Note that the packet tag returned by m_tag_alloc has the default memory
938  * alignment implemented by malloc.  To reference private data one can use a
939  * construct like:
940  *
941  *	struct m_tag *mtag = m_tag_alloc(...);
942  *	struct foo *p = (struct foo *)(mtag+1);
943  *
944  * if the alignment of struct m_tag is sufficient for referencing members of
945  * struct foo.  Otherwise it is necessary to embed struct m_tag within the
946  * private data structure to insure proper alignment; e.g.,
947  *
948  *	struct foo {
949  *		struct m_tag	tag;
950  *		...
951  *	};
952  *	struct foo *p = (struct foo *) m_tag_alloc(...);
953  *	struct m_tag *mtag = &p->tag;
954  */
955 
956 /*
957  * Persistent tags stay with an mbuf until the mbuf is reclaimed.  Otherwise
958  * tags are expected to ``vanish'' when they pass through a network
959  * interface.  For most interfaces this happens normally as the tags are
960  * reclaimed when the mbuf is free'd.  However in some special cases
961  * reclaiming must be done manually.  An example is packets that pass through
962  * the loopback interface.  Also, one must be careful to do this when
963  * ``turning around'' packets (e.g., icmp_reflect).
964  *
965  * To mark a tag persistent bit-or this flag in when defining the tag id.
966  * The tag will then be treated as described above.
967  */
968 #define	MTAG_PERSISTENT				0x800
969 
970 #define	PACKET_TAG_NONE				0  /* Nadda */
971 
972 /* Packet tags for use with PACKET_ABI_COMPAT. */
973 #define	PACKET_TAG_IPSEC_IN_DONE		1  /* IPsec applied, in */
974 #define	PACKET_TAG_IPSEC_OUT_DONE		2  /* IPsec applied, out */
975 #define	PACKET_TAG_IPSEC_IN_CRYPTO_DONE		3  /* NIC IPsec crypto done */
976 #define	PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED	4  /* NIC IPsec crypto req'ed */
977 #define	PACKET_TAG_IPSEC_IN_COULD_DO_CRYPTO	5  /* NIC notifies IPsec */
978 #define	PACKET_TAG_IPSEC_PENDING_TDB		6  /* Reminder to do IPsec */
979 #define	PACKET_TAG_BRIDGE			7  /* Bridge processing done */
980 #define	PACKET_TAG_GIF				8  /* GIF processing done */
981 #define	PACKET_TAG_GRE				9  /* GRE processing done */
982 #define	PACKET_TAG_IN_PACKET_CHECKSUM		10 /* NIC checksumming done */
983 #define	PACKET_TAG_ENCAP			11 /* Encap.  processing */
984 #define	PACKET_TAG_IPSEC_SOCKET			12 /* IPSEC socket ref */
985 #define	PACKET_TAG_IPSEC_HISTORY		13 /* IPSEC history */
986 #define	PACKET_TAG_IPV6_INPUT			14 /* IPV6 input processing */
987 #define	PACKET_TAG_DUMMYNET			15 /* dummynet info */
988 #define	PACKET_TAG_DIVERT			17 /* divert info */
989 #define	PACKET_TAG_IPFORWARD			18 /* ipforward info */
990 #define	PACKET_TAG_MACLABEL	(19 | MTAG_PERSISTENT) /* MAC label */
991 #define	PACKET_TAG_PF		(21 | MTAG_PERSISTENT) /* PF/ALTQ information */
992 #define	PACKET_TAG_RTSOCKFAM			25 /* rtsock sa family */
993 #define	PACKET_TAG_IPOPTIONS			27 /* Saved IP options */
994 #define	PACKET_TAG_CARP				28 /* CARP info */
995 #define	PACKET_TAG_IPSEC_NAT_T_PORTS		29 /* two uint16_t */
996 #define	PACKET_TAG_ND_OUTGOING			30 /* ND outgoing */
997 
998 /* Specific cookies and tags. */
999 
1000 /* Packet tag routines. */
1001 struct m_tag	*m_tag_alloc(u_int32_t, int, int, int);
1002 void		 m_tag_delete(struct mbuf *, struct m_tag *);
1003 void		 m_tag_delete_chain(struct mbuf *, struct m_tag *);
1004 void		 m_tag_free_default(struct m_tag *);
1005 struct m_tag	*m_tag_locate(struct mbuf *, u_int32_t, int, struct m_tag *);
1006 struct m_tag	*m_tag_copy(struct m_tag *, int);
1007 int		 m_tag_copy_chain(struct mbuf *, struct mbuf *, int);
1008 void		 m_tag_delete_nonpersistent(struct mbuf *);
1009 
1010 /*
1011  * Initialize the list of tags associated with an mbuf.
1012  */
1013 static __inline void
1014 m_tag_init(struct mbuf *m)
1015 {
1016 
1017 	SLIST_INIT(&m->m_pkthdr.tags);
1018 }
1019 
1020 /*
1021  * Set up the contents of a tag.  Note that this does not fill in the free
1022  * method; the caller is expected to do that.
1023  *
1024  * XXX probably should be called m_tag_init, but that was already taken.
1025  */
1026 static __inline void
1027 m_tag_setup(struct m_tag *t, u_int32_t cookie, int type, int len)
1028 {
1029 
1030 	t->m_tag_id = type;
1031 	t->m_tag_len = len;
1032 	t->m_tag_cookie = cookie;
1033 }
1034 
1035 /*
1036  * Reclaim resources associated with a tag.
1037  */
1038 static __inline void
1039 m_tag_free(struct m_tag *t)
1040 {
1041 
1042 	(*t->m_tag_free)(t);
1043 }
1044 
1045 /*
1046  * Return the first tag associated with an mbuf.
1047  */
1048 static __inline struct m_tag *
1049 m_tag_first(struct mbuf *m)
1050 {
1051 
1052 	return (SLIST_FIRST(&m->m_pkthdr.tags));
1053 }
1054 
1055 /*
1056  * Return the next tag in the list of tags associated with an mbuf.
1057  */
1058 static __inline struct m_tag *
1059 m_tag_next(struct mbuf *m, struct m_tag *t)
1060 {
1061 
1062 	return (SLIST_NEXT(t, m_tag_link));
1063 }
1064 
1065 /*
1066  * Prepend a tag to the list of tags associated with an mbuf.
1067  */
1068 static __inline void
1069 m_tag_prepend(struct mbuf *m, struct m_tag *t)
1070 {
1071 
1072 	SLIST_INSERT_HEAD(&m->m_pkthdr.tags, t, m_tag_link);
1073 }
1074 
1075 /*
1076  * Unlink a tag from the list of tags associated with an mbuf.
1077  */
1078 static __inline void
1079 m_tag_unlink(struct mbuf *m, struct m_tag *t)
1080 {
1081 
1082 	SLIST_REMOVE(&m->m_pkthdr.tags, t, m_tag, m_tag_link);
1083 }
1084 
1085 /* These are for OpenBSD compatibility. */
1086 #define	MTAG_ABI_COMPAT		0		/* compatibility ABI */
1087 
1088 static __inline struct m_tag *
1089 m_tag_get(int type, int length, int wait)
1090 {
1091 	return (m_tag_alloc(MTAG_ABI_COMPAT, type, length, wait));
1092 }
1093 
1094 static __inline struct m_tag *
1095 m_tag_find(struct mbuf *m, int type, struct m_tag *start)
1096 {
1097 	return (SLIST_EMPTY(&m->m_pkthdr.tags) ? (struct m_tag *)NULL :
1098 	    m_tag_locate(m, MTAG_ABI_COMPAT, type, start));
1099 }
1100 
1101 /* XXX temporary FIB methods probably eventually use tags.*/
1102 #define M_FIBSHIFT    28
1103 #define M_FIBMASK	0x0F
1104 
1105 /* get the fib from an mbuf and if it is not set, return the default */
1106 #define M_GETFIB(_m) \
1107     ((((_m)->m_flags & M_FIB) >> M_FIBSHIFT) & M_FIBMASK)
1108 
1109 #define M_SETFIB(_m, _fib) do {						\
1110 	_m->m_flags &= ~M_FIB;					   	\
1111 	_m->m_flags |= (((_fib) << M_FIBSHIFT) & M_FIB);  \
1112 } while (0)
1113 
1114 #endif /* _KERNEL */
1115 
1116 #ifdef MBUF_PROFILING
1117  void m_profile(struct mbuf *m);
1118  #define M_PROFILE(m) m_profile(m)
1119 #else
1120  #define M_PROFILE(m)
1121 #endif
1122 
1123 
1124 #endif /* !_SYS_MBUF_H_ */
1125