xref: /dragonfly/sys/sys/mbuf.h (revision ef3ac1d1)
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 	/* XXX implicit 4 bytes padding on x86_64 */
94 #ifdef MBUF_DEBUG
95 	const char *mh_lastfunc;
96 #endif
97 	union {
98 		struct netmsg_packet mhm_pkt;	/* hardware->proto stack msg */
99 		struct netmsg_pru_send mhm_snd;	/* usrspace->proto stack msg */
100 		struct netmsg_inarp mhm_arp;	/* proto stack<->route msg */
101 	} mh_msgu;
102 };
103 #define mh_netmsg	mh_msgu.mhm_pkt
104 #define mh_sndmsg	mh_msgu.mhm_snd
105 #define mh_arpmsg	mh_msgu.mhm_arp
106 
107 /* pf stuff */
108 struct pkthdr_pf {
109 	void		*hdr;		/* saved hdr pos in mbuf, for ECN */
110 	void		*statekey;	/* pf stackside statekey */
111 	u_int		rtableid;	/* alternate routing table id */
112 	uint32_t	qid;		/* queue id */
113 	uint16_t	tag;		/* tag id */
114 	uint8_t		flags;
115 	uint8_t		routed;
116 	uint32_t	state_hash;	/* identifies 'connections' */
117 	uint8_t		ecn_af;		/* for altq_red */
118 	uint8_t		unused01;
119 	uint8_t		unused02;
120 	uint8_t		unused03;
121 	/* XXX implicit 4 bytes padding on x86_64 */
122 };
123 
124 /* pkthdr_pf.flags */
125 #define	PF_TAG_GENERATED		0x01
126 #define	PF_TAG_FRAGCACHE		0x02
127 #define	PF_TAG_TRANSLATE_LOCALHOST	0x04
128 #define	PF_TAG_DIVERTED			0x08
129 #define	PF_TAG_DIVERTED_PACKET		0x10
130 #define	PF_TAG_REROUTE			0x20
131 
132 /*
133  * Packet tag structure (see below for details).
134  */
135 struct m_tag {
136 	SLIST_ENTRY(m_tag)	m_tag_link;	/* List of packet tags */
137 	uint16_t		m_tag_id;	/* Tag ID */
138 	uint16_t		m_tag_len;	/* Length of data */
139 	uint32_t		m_tag_cookie;	/* ABI/Module ID */
140 };
141 
142 SLIST_HEAD(packet_tags, m_tag);
143 
144 /*
145  * Record/packet header in first mbuf of chain; valid only if M_PKTHDR is set.
146  *
147  * Be careful: The fields have been carefully ordered to avoid hidden padding.
148  *             Keep this in mind, when adding or removing fields!
149  */
150 struct pkthdr {
151 	struct	ifnet *rcvif;		/* rcv interface */
152 	struct packet_tags tags;	/* list of packet tags */
153 
154 	/* variables for ip and tcp reassembly */
155 	void	*header;		/* pointer to packet header */
156 	int	len;			/* total packet length */
157 
158 	/* variables for hardware checksum */
159 	int	csum_flags;		/* flags regarding checksum */
160 	int	csum_data;		/* data field used by csum routines */
161 	uint16_t csum_iphlen;		/* IP header length */
162 					/* valid if CSUM IP|UDP|TCP|TSO */
163 	uint8_t	csum_thlen;		/* TCP/UDP header length */
164 					/* valid if CSUM UDP|TCP|TSO */
165 	uint8_t	csum_lhlen;		/* link header length */
166 
167 	uint16_t tso_segsz;		/* TSO segment size */
168 	uint16_t ether_vlantag;		/* ethernet 802.1p+q vlan tag */
169 
170 	uint16_t hash;			/* packet hash */
171 	uint16_t unused1;		/* reserved for route table id */
172 	uint32_t unused2;		/* reserved for codel timestamp */
173 
174 	uint16_t wlan_seqno;		/* IEEE 802.11 seq no. */
175 	/*
176 	 * Valid if BRIDGE_MBUF_TAGGED is set in fw_flags, records
177 	 * the original ether source address (if compatible).
178 	 */
179 	uint8_t ether_br_shost[ETHER_ADDR_LEN];
180 
181 	/* firewall flags */
182 	uint32_t fw_flags;		/* flags for FW */
183 
184 	/* variables for PF processing */
185 	struct pkthdr_pf pf;		/* structure for PF */
186 };
187 
188 /*
189  * Description of external storage mapped into mbuf; valid only if M_EXT is set.
190  */
191 struct m_ext {
192 	caddr_t	ext_buf;		/* start of buffer */
193 	void	(*ext_free)(void *);
194 	u_int	ext_size;		/* size of buffer, for ext_free */
195 	void	(*ext_ref)(void *);
196 	void	*ext_arg;
197 };
198 
199 /*
200  * The core of the mbuf object along with some shortcut defines for
201  * practical purposes.
202  */
203 struct mbuf {
204 	struct	m_hdr m_hdr;
205 	union {
206 		struct {
207 			struct	pkthdr MH_pkthdr;	/* M_PKTHDR set */
208 			union {
209 				struct	m_ext MH_ext;	/* M_EXT set */
210 				char	MH_databuf[MHLEN];
211 			} MH_dat;
212 		} MH;
213 		char	M_databuf[MLEN];		/* !M_PKTHDR, !M_EXT */
214 	} M_dat;
215 };
216 #define	m_next		m_hdr.mh_next
217 #define	m_len		m_hdr.mh_len
218 #define	m_data		m_hdr.mh_data
219 #define	m_type		m_hdr.mh_type
220 #define	m_flags		m_hdr.mh_flags
221 #define	m_nextpkt	m_hdr.mh_nextpkt
222 #define	m_pkthdr	M_dat.MH.MH_pkthdr
223 #define	m_ext		M_dat.MH.MH_dat.MH_ext
224 #define	m_pktdat	M_dat.MH.MH_dat.MH_databuf
225 #define	m_dat		M_dat.M_databuf
226 
227 /*
228  * Code that uses m_act should be converted to use m_nextpkt
229  * instead; m_act is historical and deprecated.
230  */
231 #define m_act   	m_nextpkt
232 
233 /*
234  * mbuf flags.
235  */
236 #define	M_EXT		0x0001	/* has associated external storage */
237 #define	M_PKTHDR	0x0002	/* start of record */
238 #define	M_EOR		0x0004	/* end of record */
239 #define	M_PROTO1	0x0008	/* protocol-specific */
240 #define	M_PROTO2	0x0010	/* protocol-specific */
241 #define	M_PROTO3	0x0020	/* protocol-specific */
242 #define	M_PROTO4	0x0040	/* protocol-specific */
243 #define	M_PROTO5	0x0080	/* protocol-specific */
244 
245 /*
246  * mbuf pkthdr flags (also stored in m_flags).
247  */
248 #define	M_BCAST		0x0100	/* send/received as link-level broadcast */
249 #define	M_MCAST		0x0200	/* send/received as link-level multicast */
250 #define	M_FRAG		0x0400	/* packet is a fragment of a larger packet */
251 #define	M_FIRSTFRAG	0x0800	/* packet is first fragment */
252 #define	M_LASTFRAG	0x1000	/* packet is last fragment */
253 #define	M_CLCACHE	0x2000	/* mbuf allocated from the cluster cache */
254 #define M_EXT_CLUSTER	0x4000	/* standard cluster else special */
255 #define	M_PHCACHE	0x8000	/* mbuf allocated from the pkt header cache */
256 #define M_NOTIFICATION	0x10000	/* notification event */
257 #define M_VLANTAG	0x20000	/* ether_vlantag is valid */
258 #define M_MPLSLABELED	0x40000	/* packet is mpls labeled */
259 #define M_LENCHECKED	0x80000	/* packet proto lengths are checked */
260 #define M_HASH		0x100000/* hash field in pkthdr is valid */
261 #define M_PROTO6        0x200000/* protocol-specific */
262 #define M_PROTO7        0x400000/* protocol-specific */
263 #define M_PROTO8        0x800000/* protocol-specific */
264 #define M_CKHASH	0x1000000/* hash needs software verification */
265 #define M_PRIO		0x2000000/* high priority mbuf */
266 #define M_SOLOCKED	0x4000000/* locked by userland for read() */
267 
268 /*
269  * Flags copied when copying m_pkthdr.
270  */
271 #define	M_COPYFLAGS	(M_PKTHDR|M_EOR|M_PROTO1|M_PROTO2|M_PROTO3 | \
272 			 M_PROTO4|M_PROTO5|M_PROTO6|M_PROTO7|M_PROTO8 | \
273 			 M_BCAST|M_MCAST|M_FRAG|M_FIRSTFRAG|M_LASTFRAG | \
274 			 M_VLANTAG|M_MPLSLABELED | \
275 			 M_LENCHECKED|M_HASH|M_CKHASH|M_PRIO)
276 
277 /*
278  * Flags indicating hw checksum support and sw checksum requirements.
279  */
280 #define	CSUM_IP			0x0001		/* will csum IP */
281 #define	CSUM_TCP		0x0002		/* will csum TCP */
282 #define	CSUM_UDP		0x0004		/* will csum UDP */
283 #define	CSUM_IP_FRAGS		0x0008		/* will csum IP fragments */
284 #define	CSUM_FRAGMENT		0x0010		/* will do IP fragmentation */
285 
286 #define	CSUM_IP_CHECKED		0x0100		/* did csum IP */
287 #define	CSUM_IP_VALID		0x0200		/*   ... the csum is valid */
288 #define	CSUM_DATA_VALID		0x0400		/* csum_data field is valid */
289 #define	CSUM_PSEUDO_HDR		0x0800		/* csum_data has pseudo hdr */
290 #define CSUM_FRAG_NOT_CHECKED	0x1000		/* did _not_ csum fragment
291 						 * NB: This flag is only used
292 						 * by IP defragmenter.
293 						 */
294 #define CSUM_TSO		0x2000		/* will do TCP segmentation */
295 
296 #define	CSUM_DELAY_DATA		(CSUM_TCP | CSUM_UDP)
297 #define	CSUM_DELAY_IP		(CSUM_IP)	/* XXX add ipv6 here too? */
298 
299 /*
300  * Flags indicating PF processing status
301  */
302 #define FW_MBUF_GENERATED	0x00000001
303 #define	PF_MBUF_STRUCTURE	0x00000002	/* m_pkthdr.pf valid */
304 #define	PF_MBUF_ROUTED		0x00000004	/* pf_routed field is valid */
305 #define	PF_MBUF_TAGGED		0x00000008
306 #define	XX_MBUF_UNUSED10	0x00000010
307 #define	XX_MBUF_UNUSED20	0x00000020
308 #define IPFORWARD_MBUF_TAGGED	0x00000040
309 #define DUMMYNET_MBUF_TAGGED	0x00000080
310 #define BRIDGE_MBUF_TAGGED	0x00000100
311 #define FW_MBUF_REDISPATCH	0x00000200
312 #define	IPFW_MBUF_GENERATED	FW_MBUF_GENERATED
313 /*
314  * mbuf types.
315  */
316 #define	MT_FREE		0	/* should be on free list */
317 #define	MT_DATA		1	/* dynamic (data) allocation */
318 #define	MT_HEADER	2	/* packet header */
319 #define	MT_SONAME	3	/* socket name */
320 /* 4 was MT_TAG */
321 #define	MT_CONTROL	5	/* extra-data protocol message */
322 #define	MT_OOBDATA	6	/* expedited data  */
323 #define	MT_NTYPES	7	/* number of mbuf types for mbtypes[] */
324 
325 /*
326  * General mbuf allocator statistics structure.
327  *
328  * NOTE: Make sure this struct's size is multiple cache line size.
329  */
330 struct mbstat {
331 	u_long	m_mbufs;	/* mbufs obtained from page pool */
332 	u_long	m_clusters;	/* clusters obtained from page pool */
333 	u_long	m_jclusters;	/* jclusters obtained from page pool */
334 	u_long	m_clfree;	/* free clusters */
335 	u_long	m_drops;	/* times failed to find space */
336 	u_long	m_wait;		/* times waited for space */
337 	u_long	m_drain;	/* times drained protocols for space */
338 	u_long	m_mcfail;	/* times m_copym failed */
339 	u_long	m_mpfail;	/* times m_pullup failed */
340 	u_long	m_msize;	/* length of an mbuf */
341 	u_long	m_mclbytes;	/* length of an mbuf cluster */
342 	u_long	m_mjumpagesize;	/* length of a jumbo mbuf cluster */
343 	u_long	m_minclsize;	/* min length of data to allocate a cluster */
344 	u_long	m_mlen;		/* length of data in an mbuf */
345 	u_long	m_mhlen;	/* length of data in a header mbuf */
346 	u_long	m_pad;		/* pad to cache line size (64B) */
347 };
348 
349 /*
350  * Flags specifying how an allocation should be made.
351  */
352 
353 #define	MB_DONTWAIT	0x4
354 #define	MB_TRYWAIT	0x8
355 #define	MB_WAIT		MB_TRYWAIT
356 
357 /*
358  * Mbuf to Malloc Flag Conversion.
359  */
360 #define	MBTOM(how)	((how) & MB_TRYWAIT ? M_WAITOK : M_NOWAIT)
361 
362 /*
363  * These are identifying numbers passed to the m_mballoc_wait function,
364  * allowing us to determine whether the call came from an MGETHDR or
365  * an MGET.
366  */
367 #define	MGETHDR_C      1
368 #define	MGET_C         2
369 
370 /*
371  * mbuf allocation/deallocation macros (YYY deprecated, too big):
372  *
373  *	MGET(struct mbuf *m, int how, int type)
374  * allocates an mbuf and initializes it to contain internal data.
375  *
376  *	MGETHDR(struct mbuf *m, int how, int type)
377  * allocates an mbuf and initializes it to contain a packet header
378  * and internal data.
379  */
380 #define	MGET(m, how, type) do {						\
381 	(m) = m_get((how), (type));					\
382 } while (0)
383 
384 #define	MGETHDR(m, how, type) do {					\
385 	(m) = m_gethdr((how), (type));					\
386 } while (0)
387 
388 /*
389  * MCLGET adds such clusters to a normal mbuf.  The flag M_EXT is set upon
390  * success.
391  * Deprecated.  Use m_getcl() or m_getl() instead.
392  */
393 #define	MCLGET(m, how) do {						\
394 	m_mclget((m), (how));						\
395 } while (0)
396 
397 /*
398  * NB: M_COPY_PKTHDR is deprecated; use either M_MOVE_PKTHDR
399  *     or m_dup_pkthdr.
400  */
401 /*
402  * Move mbuf pkthdr from "from" to "to".
403  * from should have M_PKTHDR set, and to must be empty.
404  * from no longer has a pkthdr after this operation.
405  */
406 #define	M_MOVE_PKTHDR(_to, _from)	m_move_pkthdr((_to), (_from))
407 
408 /*
409  * Set the m_data pointer of a newly-allocated mbuf (m_get/MGET) to place
410  * an object of the specified size at the end of the mbuf, longword aligned.
411  */
412 #define	M_ALIGN(m, len) do {						\
413 	(m)->m_data += (MLEN - (len)) & ~(sizeof(long) - 1);		\
414 } while (0)
415 
416 /*
417  * As above, for mbufs allocated with m_gethdr/MGETHDR
418  * or initialized by M_COPY_PKTHDR.
419  */
420 #define	MH_ALIGN(m, len) do {						\
421 	(m)->m_data += (MHLEN - (len)) & ~(sizeof(long) - 1);		\
422 } while (0)
423 
424 /*
425  * Check if we can write to an mbuf.
426  */
427 #define M_EXT_WRITABLE(m)	(m_sharecount(m) == 1)
428 #define M_WRITABLE(m)		(!((m)->m_flags & M_EXT) || M_EXT_WRITABLE(m))
429 
430 /*
431  * Check if the supplied mbuf has a packet header, or else panic.
432  */
433 #define	M_ASSERTPKTHDR(m)						\
434 	KASSERT(m != NULL && m->m_flags & M_PKTHDR,			\
435 		("%s: invalid mbuf or no mbuf packet header!", __func__))
436 
437 /*
438  * Compute the amount of space available before the current start of data.
439  * The M_EXT_WRITABLE() is a temporary, conservative safety measure: the burden
440  * of checking writability of the mbuf data area rests solely with the caller.
441  */
442 #define	M_LEADINGSPACE(m)						\
443 	((m)->m_flags & M_EXT ?						\
444 	    (M_EXT_WRITABLE(m) ? (m)->m_data - (m)->m_ext.ext_buf : 0):	\
445 	    (m)->m_flags & M_PKTHDR ? (m)->m_data - (m)->m_pktdat :	\
446 	    (m)->m_data - (m)->m_dat)
447 
448 /*
449  * Compute the amount of space available after the end of data in an mbuf.
450  * The M_WRITABLE() is a temporary, conservative safety measure: the burden
451  * of checking writability of the mbuf data area rests solely with the caller.
452  */
453 #define	M_TRAILINGSPACE(m)						\
454 	((m)->m_flags & M_EXT ?						\
455 	    (M_WRITABLE(m) ? (m)->m_ext.ext_buf + (m)->m_ext.ext_size	\
456 		- ((m)->m_data + (m)->m_len) : 0) :			\
457 	    &(m)->m_dat[MLEN] - ((m)->m_data + (m)->m_len))
458 
459 /*
460  * Arrange to prepend space of size plen to mbuf m.
461  * If a new mbuf must be allocated, how specifies whether to wait.
462  * If how is MB_DONTWAIT and allocation fails, the original mbuf chain
463  * is freed and m is set to NULL.
464  */
465 #define	M_PREPEND(m, plen, how) do {					\
466 	struct mbuf **_mmp = &(m);					\
467 	struct mbuf *_mm = *_mmp;					\
468 	int _mplen = (plen);						\
469 	int __mhow = (how);						\
470 									\
471 	if (M_LEADINGSPACE(_mm) >= _mplen) {				\
472 		_mm->m_data -= _mplen;					\
473 		_mm->m_len += _mplen;					\
474 	} else								\
475 		_mm = m_prepend(_mm, _mplen, __mhow);			\
476 	if (_mm != NULL && (_mm->m_flags & M_PKTHDR))			\
477 		_mm->m_pkthdr.len += _mplen;				\
478 	*_mmp = _mm;							\
479 } while (0)
480 
481 /* Length to m_copy to copy all. */
482 #define	M_COPYALL	1000000000
483 
484 /* Compatibility with 4.3 */
485 #define	m_copy(m, o, l)	m_copym((m), (o), (l), MB_DONTWAIT)
486 
487 #ifdef _KERNEL
488 extern	u_int		 m_clalloc_wid;	/* mbuf cluster wait count */
489 extern	u_int		 m_mballoc_wid;	/* mbuf wait count */
490 extern	int		 max_linkhdr;	/* largest link-level header */
491 extern	int		 max_protohdr;	/* largest protocol header */
492 extern	int		 max_hdr;	/* largest link+protocol header */
493 extern	int		 max_datalen;	/* MHLEN - max_hdr */
494 extern	int		 mbuf_wait;	/* mbuf sleep time */
495 extern	int		 nmbclusters;
496 extern	int		 nmbufs;
497 
498 struct uio;
499 
500 void		 m_adj(struct mbuf *, int);
501 void		 m_align(struct mbuf *, int);
502 int		 m_apply(struct mbuf *, int, int,
503 		    int (*)(void *, void *, u_int), void *);
504 int		m_append(struct mbuf *, int, c_caddr_t);
505 void		 m_cat(struct mbuf *, struct mbuf *);
506 u_int		 m_countm(struct mbuf *m, struct mbuf **lastm, u_int *mbcnt);
507 void		 m_copyback(struct mbuf *, int, int, caddr_t);
508 void		 m_copydata(const struct mbuf *, int, int, caddr_t);
509 struct	mbuf	*m_copym(const struct mbuf *, int, int, int);
510 struct	mbuf	*m_copypacket(struct mbuf *, int);
511 struct	mbuf	*m_defrag(struct mbuf *, int);
512 struct	mbuf	*m_defrag_nofree(struct mbuf *, int);
513 struct	mbuf	*m_devget(char *, int, int, struct ifnet *,
514 		  void (*copy)(volatile const void *, volatile void *, size_t));
515 struct	mbuf	*m_dup(struct mbuf *, int);
516 struct	mbuf	*m_dup_data(struct mbuf *, int);
517 int		 m_dup_pkthdr(struct mbuf *, const struct mbuf *, int);
518 void		 m_extadd(struct mbuf *, caddr_t, u_int, void (*)(void *),
519 		  void (*)(void *), void *);
520 #ifdef MBUF_DEBUG
521 struct	mbuf	*_m_free(struct mbuf *, const char *name);
522 void		 _m_freem(struct mbuf *, const char *name);
523 #else
524 struct	mbuf	*m_free(struct mbuf *);
525 void		 m_freem(struct mbuf *);
526 #endif
527 struct	mbuf	*m_get(int, int);
528 struct	mbuf	*m_getc(int len, int how, int type);
529 struct	mbuf	*m_getcl(int how, short type, int flags);
530 struct	mbuf	*m_getjcl(int how, short type, int flags, size_t size);
531 struct	mbuf	*m_getclr(int, int);
532 struct	mbuf	*m_gethdr(int, int);
533 struct	mbuf	*m_getm(struct mbuf *, int, int, int);
534 struct	mbuf	*m_getptr(struct mbuf *, int, int *);
535 struct	mbuf	*m_last(struct mbuf *m);
536 u_int		 m_lengthm(struct mbuf *m, struct mbuf **lastm);
537 void		 m_move_pkthdr(struct mbuf *, struct mbuf *);
538 struct	mbuf	*m_prepend(struct mbuf *, int, int);
539 void		 m_print(const struct mbuf *m);
540 struct	mbuf	*m_pulldown(struct mbuf *, int, int, int *);
541 struct	mbuf	*m_pullup(struct mbuf *, int);
542 struct	mbuf	*m_split(struct mbuf *, int, int);
543 struct	mbuf 	*m_uiomove(struct uio *);
544 struct	mbuf	*m_unshare(struct mbuf *, int);
545 void		m_mclget(struct mbuf *m, int how);
546 int		m_sharecount(struct mbuf *m);
547 void		m_chtype(struct mbuf *m, int type);
548 int		m_devpad(struct mbuf *m, int padto);
549 
550 #ifdef MBUF_DEBUG
551 
552 void		mbuftrackid(struct mbuf *, int);
553 
554 #define m_free(m)	_m_free(m, __func__)
555 #define m_freem(m)	_m_freem(m, __func__)
556 
557 #else
558 
559 #define mbuftrackid(m, id)	/* empty */
560 
561 #endif
562 
563 /*
564  * Allocate the right type of mbuf for the desired total length.
565  * The mbuf returned does not necessarily cover the entire requested length.
566  * This function follows mbuf chaining policy of allowing MINCLSIZE
567  * amount of chained mbufs.
568  */
569 static __inline struct mbuf *
570 m_getl(int len, int how, int type, int flags, int *psize)
571 {
572 	struct mbuf *m;
573 	int size;
574 
575 	if (len >= MINCLSIZE) {
576 		m = m_getcl(how, type, flags);
577 		size = MCLBYTES;
578 	} else if (flags & M_PKTHDR) {
579 		m = m_gethdr(how, type);
580 		size = MHLEN;
581 	} else {
582 		m = m_get(how, type);
583 		size = MLEN;
584 	}
585 	if (psize != NULL)
586 		*psize = size;
587 	return (m);
588 }
589 
590 static __inline struct mbuf *
591 m_getlj(int len, int how, int type, int flags, int *psize)
592 {
593 	if (len > MCLBYTES) {
594 		struct mbuf *m;
595 
596 		m = m_getjcl(how, type, flags, MJUMPAGESIZE);
597 		if (psize != NULL)
598 			*psize = MJUMPAGESIZE;
599 		return m;
600 	}
601 	return m_getl(len, how, type, flags, psize);
602 }
603 
604 /*
605  * Get a single mbuf that covers the requested number of bytes.
606  * This function does not create mbuf chains.  It explicitly marks
607  * places in the code that abuse mbufs for contiguous data buffers.
608  */
609 static __inline struct mbuf *
610 m_getb(int len, int how, int type, int flags)
611 {
612 	struct mbuf *m;
613 	int mbufsize = (flags & M_PKTHDR) ? MHLEN : MLEN;
614 
615 	if (len > mbufsize)
616 		m = m_getcl(how, type, flags);
617 	else if (flags & M_PKTHDR)
618 		m = m_gethdr(how, type);
619 	else
620 		m = m_get(how, type);
621 	return (m);
622 }
623 
624 /*
625  * Packets may have annotations attached by affixing a list
626  * of "packet tags" to the pkthdr structure.  Packet tags are
627  * dynamically allocated semi-opaque data structures that have
628  * a fixed header (struct m_tag) that specifies the size of the
629  * memory block and a <cookie,type> pair that identifies it.
630  * The cookie is a 32-bit unique unsigned value used to identify
631  * a module or ABI.  By convention this value is chose as the
632  * date+time that the module is created, expressed as the number of
633  * seconds since the epoch (e.g. using date -u +'%s').  The type value
634  * is an ABI/module-specific value that identifies a particular annotation
635  * and is private to the module.  For compatibility with systems
636  * like openbsd that define packet tags w/o an ABI/module cookie,
637  * the value PACKET_ABI_COMPAT is used to implement m_tag_get and
638  * m_tag_find compatibility shim functions and several tag types are
639  * defined below.  Users that do not require compatibility should use
640  * a private cookie value so that packet tag-related definitions
641  * can be maintained privately.
642  *
643  * Note that the packet tag returned by m_tag_alloc has the default
644  * memory alignment implemented by kmalloc.  To reference private data
645  * one can use a construct like:
646  *
647  *	struct m_tag *mtag = m_tag_alloc(...);
648  *	struct foo *p = m_tag_data(mtag);
649  *
650  * if the alignment of struct m_tag is sufficient for referencing members
651  * of struct foo.  Otherwise it is necessary to embed struct m_tag within
652  * the private data structure to insure proper alignment; e.g.
653  *
654  *	struct foo {
655  *		struct m_tag	tag;
656  *		...
657  *	};
658  *	struct foo *p = (struct foo *)m_tag_alloc(...);
659  *	struct m_tag *mtag = &p->tag;
660  */
661 
662 #define	PACKET_TAG_NONE				0  /* Nadda */
663 
664 /* Packet tag for use with PACKET_ABI_COMPAT */
665 #define	PACKET_TAG_IPSEC_IN_DONE		1  /* IPsec applied, in */
666 /* struct tdb_indent */
667 #define	PACKET_TAG_IPSEC_OUT_DONE		2  /* IPsec applied, out */
668 /* struct tdb_indent */
669 #define	PACKET_TAG_IPSEC_IN_CRYPTO_DONE		3  /* NIC IPsec crypto done */
670 /* struct tdb_indent, never added */
671 #define	PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED	4  /* NIC IPsec crypto req'ed */
672 /* struct tdb_indent, never added */
673 #define	PACKET_TAG_IPSEC_PENDING_TDB		5  /* Reminder to do IPsec */
674 /* struct tdb_indent, never added */
675 #define	PACKET_TAG_ENCAP			6 /* Encap.  processing */
676 /* struct ifnet *, the GIF interface */
677 #define	PACKET_TAG_IPSEC_HISTORY		7 /* IPSEC history */
678 /* struct ipsec_history */
679 #define	PACKET_TAG_IPV6_INPUT			8 /* IPV6 input processing */
680 /* struct ip6aux */
681 #define	PACKET_TAG_IPFW_DIVERT			9 /* divert info */
682 /* struct divert_info */
683 #define	PACKET_TAG_DUMMYNET			15 /* dummynet info */
684 /* struct dn_pkt */
685 #define	PACKET_TAG_IPFORWARD			18 /* ipforward info */
686 /* struct sockaddr_in */
687 #define PACKET_TAG_IPSRCRT			27 /* IP srcrt opts */
688 /* struct ip_srcrt_opt */
689 #define	PACKET_TAG_CARP                         28 /* CARP info */
690 /* struct pf_mtag */
691 #define PACKET_TAG_PF				29 /* PF info */
692 
693 #define PACKET_TAG_PF_DIVERT			0x0200 /* pf(4) diverted packet */
694 
695 
696 /* Packet tag routines */
697 struct	m_tag 	*m_tag_alloc(uint32_t, int, int, int);
698 void		 m_tag_free(struct m_tag *);
699 void		 m_tag_prepend(struct mbuf *, struct m_tag *);
700 void		 m_tag_unlink(struct mbuf *, struct m_tag *);
701 void		 m_tag_delete(struct mbuf *, struct m_tag *);
702 void		 m_tag_delete_chain(struct mbuf *);
703 struct	m_tag	*m_tag_locate(struct mbuf *, uint32_t, int, struct m_tag *);
704 struct	m_tag	*m_tag_copy(struct m_tag *, int);
705 int		 m_tag_copy_chain(struct mbuf *, const struct mbuf *, int);
706 void		 m_tag_init(struct mbuf *);
707 struct	m_tag	*m_tag_first(struct mbuf *);
708 struct	m_tag	*m_tag_next(struct mbuf *, struct m_tag *);
709 
710 /* these are for openbsd compatibility */
711 #define	MTAG_ABI_COMPAT		0		/* compatibility ABI */
712 
713 static __inline void *
714 m_tag_data(struct m_tag *tag)
715 {
716 	return ((void *)(tag + 1));
717 }
718 
719 static __inline struct m_tag *
720 m_tag_get(int type, int length, int wait)
721 {
722 	return m_tag_alloc(MTAG_ABI_COMPAT, type, length, wait);
723 }
724 
725 static __inline struct m_tag *
726 m_tag_find(struct mbuf *m, int type, struct m_tag *start)
727 {
728 	return m_tag_locate(m, MTAG_ABI_COMPAT, type, start);
729 }
730 
731 #endif	/* _KERNEL */
732 
733 #endif	/* _KERNEL || _KERNEL_STRUCTURES */
734 #endif	/* !_SYS_MBUF_H_ */
735