xref: /dflybsd-src/sys/sys/mbuf.h (revision 617f6bd6553bb7523bb0198e7aaa5d9c36fb6e05)
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. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  *
31  *	@(#)mbuf.h	8.5 (Berkeley) 2/19/95
32  * $FreeBSD: src/sys/sys/mbuf.h,v 1.44.2.17 2003/04/15 06:15:02 silby Exp $
33  */
34 
35 #ifndef _SYS_MBUF_H_
36 #define	_SYS_MBUF_H_
37 
38 #if defined(_KERNEL) || defined(_KERNEL_STRUCTURES)
39 
40 #ifndef _SYS_TYPES_H_
41 #include <sys/types.h>
42 #endif
43 #ifndef _SYS_PARAM_H_
44 #include <sys/param.h>
45 #endif
46 #ifndef _SYS_QUEUE_H_
47 #include <sys/queue.h>
48 #endif
49 #ifndef _NET_NETISR_H_
50 #include <net/netisr.h>
51 #endif
52 #ifndef _NET_ETHERNET_H_
53 #include <net/ethernet.h>
54 #endif
55 
56 /*
57  * Mbufs are of a single size, MSIZE (machine/param.h), which
58  * includes overhead.  An mbuf may add a single "mbuf cluster" of size
59  * MCLBYTES (also in machine/param.h), which has no additional overhead
60  * and is used instead of the internal data area; this is done when
61  * at least MINCLSIZE of data must be stored.
62  */
63 #define	MLEN		(MSIZE - sizeof(struct m_hdr))	/* normal data len */
64 #define	MHLEN		(MLEN - sizeof(struct pkthdr))	/* data len w/pkthdr */
65 #define	MINCLSIZE	(MHLEN + 1)	/* smallest amount to put in cluster */
66 #define	M_MAXCOMPRESS	(MHLEN / 2)	/* max amount to copy for compression */
67 
68 /*
69  * Macros for type conversion:
70  * mtod(m, t)		-- Convert mbuf pointer to data pointer of correct type.
71  * mtodoff(m, t, off)	-- Convert mbuf pointer at the specified offset to data
72  *			   pointer of correct type.
73  */
74 #define	mtod(m, t)		((t)((m)->m_data))
75 #define	mtodoff(m, t, off)	((t)((m)->m_data + (off)))
76 
77 /*
78  * Header present at the beginning of every mbuf.
79  */
80 struct m_hdr {
81 	struct	mbuf *mh_next;		/* next buffer in chain */
82 	union {
83 		struct	mbuf *mh_nextpkt; /* next chain in queue/record */
84 		STAILQ_ENTRY(mbuf) mh_stailqpkt;
85 	};
86 	caddr_t	mh_data;		/* location of data */
87 	int	mh_len;			/* amount of data in this mbuf */
88 	int	mh_flags;		/* flags; see below */
89 	short	mh_type;		/* type of data in this mbuf */
90 	short	mh_pad;			/* padding */
91 	/* XXX implicit 4 bytes padding on x86_64 */
92 #ifdef MBUF_DEBUG
93 	const char *mh_lastfunc;
94 #endif
95 	union {
96 		struct netmsg_packet mhm_pkt;	/* hardware->proto stack msg */
97 		struct netmsg_pru_send mhm_snd;	/* usrspace->proto stack msg */
98 		struct netmsg_inarp mhm_arp;	/* proto stack arpinput msg */
99 		struct netmsg_ctlinput mhm_ctl;	/* proto stack ctlinput msg */
100 		struct netmsg_genpkt mhm_gen;	/* generic pkt send/recv 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 #define mh_ctlmsg	mh_msgu.mhm_ctl
107 #define mh_genmsg	mh_msgu.mhm_gen
108 
109 /* pf stuff */
110 struct pkthdr_pf {
111 	void		*hdr;		/* saved hdr pos in mbuf, for ECN */
112 	void		*statekey;	/* pf stackside statekey */
113 	u_int		rtableid;	/* alternate routing table id */
114 	uint32_t	qid;		/* queue id */
115 	uint16_t	tag;		/* tag id */
116 	uint8_t		flags;
117 	uint8_t		routed;
118 	uint32_t	state_hash;	/* identifies 'connections' */
119 	uint8_t		ecn_af;		/* for altq_red */
120 	uint8_t		unused01;
121 	uint8_t		unused02;
122 	uint8_t		unused03;
123 	/* XXX implicit 4 bytes padding on x86_64 */
124 };
125 
126 /* pkthdr_pf.flags */
127 #define	PF_TAG_GENERATED		0x01
128 #define	PF_TAG_FRAGCACHE		0x02
129 #define	PF_TAG_TRANSLATE_LOCALHOST	0x04
130 #define	PF_TAG_DIVERTED			0x08
131 #define	PF_TAG_DIVERTED_PACKET		0x10
132 #define	PF_TAG_REROUTE			0x20
133 
134 /*
135  * Packet tag structure (see below for details).
136  */
137 struct m_tag {
138 	SLIST_ENTRY(m_tag)	m_tag_link;	/* List of packet tags */
139 	uint16_t		m_tag_id;	/* Tag ID */
140 	uint16_t		m_tag_len;	/* Length of data */
141 	uint32_t		m_tag_cookie;	/* ABI/Module ID */
142 };
143 
144 SLIST_HEAD(packet_tags, m_tag);
145 
146 /*
147  * Record/packet header in first mbuf of chain; valid only if M_PKTHDR is set.
148  *
149  * Be careful: The fields have been carefully ordered to avoid hidden padding.
150  *             Keep this in mind, when adding or removing fields!
151  */
152 struct pkthdr {
153 	struct	ifnet *rcvif;		/* rcv interface */
154 	struct packet_tags tags;	/* list of packet tags */
155 
156 	/* variables for ip and tcp reassembly */
157 	void	*header;		/* pointer to packet header */
158 	int	len;			/* total packet length */
159 
160 	/* variables for hardware checksum */
161 	int	csum_flags;		/* flags regarding checksum */
162 	int	csum_data;		/* data field used by csum routines */
163 	uint16_t csum_iphlen;		/* IP header length */
164 					/* valid if CSUM IP|UDP|TCP|TSO */
165 	uint8_t	csum_thlen;		/* TCP/UDP header length */
166 					/* valid if CSUM UDP|TCP|TSO */
167 	uint8_t	csum_lhlen;		/* link header length */
168 
169 	uint16_t tso_segsz;		/* TSO segment size */
170 	uint16_t ether_vlantag;		/* ethernet 802.1p+q vlan tag */
171 
172 	uint16_t hash;			/* packet hash */
173 	uint16_t unused1;		/* reserved for route table id */
174 	uint32_t unused2;		/* reserved for codel timestamp */
175 
176 	uint16_t wlan_seqno;		/* IEEE 802.11 seq no. */
177 	/*
178 	 * Valid if BRIDGE_MBUF_TAGGED is set in fw_flags, records
179 	 * the original ether source address (if compatible).
180 	 */
181 	uint8_t ether_br_shost[ETHER_ADDR_LEN];
182 
183 	/* firewall flags */
184 	uint32_t fw_flags;		/* flags for FW */
185 
186 	/* variables for PF processing */
187 	struct pkthdr_pf pf;		/* structure for PF */
188 };
189 
190 /*
191  * Description of external storage mapped into mbuf; valid only if M_EXT is set.
192  */
193 struct m_ext {
194 	caddr_t	ext_buf;		/* start of buffer */
195 	void	(*ext_free)(void *);
196 	u_int	ext_size;		/* size of buffer, for ext_free */
197 	void	(*ext_ref)(void *);
198 	void	*ext_arg;
199 };
200 
201 /*
202  * The core of the mbuf object along with some shortcut defines for
203  * practical purposes.
204  */
205 struct mbuf {
206 	struct	m_hdr m_hdr;
207 	union {
208 		struct {
209 			struct	pkthdr MH_pkthdr;	/* M_PKTHDR set */
210 			union {
211 				struct	m_ext MH_ext;	/* M_EXT set */
212 				char	MH_databuf[MHLEN];
213 			} MH_dat;
214 		} MH;
215 		char	M_databuf[MLEN];		/* !M_PKTHDR, !M_EXT */
216 	} M_dat;
217 };
218 #define	m_next		m_hdr.mh_next
219 #define	m_len		m_hdr.mh_len
220 #define	m_data		m_hdr.mh_data
221 #define	m_type		m_hdr.mh_type
222 #define	m_flags		m_hdr.mh_flags
223 #define	m_nextpkt	m_hdr.mh_nextpkt
224 #define	m_stailqpkt	m_hdr.mh_stailqpkt
225 #define	m_pkthdr	M_dat.MH.MH_pkthdr
226 #define	m_ext		M_dat.MH.MH_dat.MH_ext
227 #define	m_pktdat	M_dat.MH.MH_dat.MH_databuf
228 #define	m_dat		M_dat.M_databuf
229 
230 /*
231  * Code that uses m_act should be converted to use m_nextpkt
232  * instead; m_act is historical and deprecated.
233  */
234 #define m_act   	m_nextpkt
235 
236 /*
237  * mbuf flags.
238  */
239 #define	M_EXT		0x0001	/* has associated external storage */
240 #define	M_PKTHDR	0x0002	/* start of record */
241 #define	M_EOR		0x0004	/* end of record */
242 #define	M_PROTO1	0x0008	/* protocol-specific */
243 #define	M_PROTO2	0x0010	/* protocol-specific */
244 #define	M_PROTO3	0x0020	/* protocol-specific */
245 #define	M_PROTO4	0x0040	/* protocol-specific */
246 #define	M_PROTO5	0x0080	/* protocol-specific */
247 
248 /*
249  * mbuf pkthdr flags (also stored in m_flags).
250  */
251 #define	M_BCAST		0x0100	/* send/received as link-level broadcast */
252 #define	M_MCAST		0x0200	/* send/received as link-level multicast */
253 #define	M_FRAG		0x0400	/* packet is a fragment of a larger packet */
254 #define	M_FIRSTFRAG	0x0800	/* packet is first fragment */
255 #define	M_LASTFRAG	0x1000	/* packet is last fragment */
256 #define	M_CLCACHE	0x2000	/* mbuf allocated from the cluster cache */
257 #define M_EXT_CLUSTER	0x4000	/* standard cluster else special */
258 #define	M_PHCACHE	0x8000	/* mbuf allocated from the pkt header cache */
259 #define M_UNUSED16	0x10000	/* was: notification event (SCTP) */
260 #define M_VLANTAG	0x20000	/* ether_vlantag is valid */
261 #define M_MPLSLABELED	0x40000	/* packet is mpls labeled */
262 #define M_LENCHECKED	0x80000	/* packet proto lengths are checked */
263 #define M_HASH		0x100000/* hash field in pkthdr is valid */
264 #define M_PROTO6        0x200000/* protocol-specific */
265 #define M_PROTO7        0x400000/* protocol-specific */
266 #define M_PROTO8        0x800000/* protocol-specific */
267 #define M_CKHASH	0x1000000/* hash needs software verification */
268 #define M_PRIO		0x2000000/* high priority mbuf */
269 #define M_SOLOCKED	0x4000000/* locked by userland for read() */
270 
271 /*
272  * Flags copied when copying m_pkthdr.
273  */
274 #define	M_COPYFLAGS	(M_PKTHDR|M_EOR|M_PROTO1|M_PROTO2|M_PROTO3 | \
275 			 M_PROTO4|M_PROTO5|M_PROTO6|M_PROTO7|M_PROTO8 | \
276 			 M_BCAST|M_MCAST|M_FRAG|M_FIRSTFRAG|M_LASTFRAG | \
277 			 M_VLANTAG|M_MPLSLABELED | \
278 			 M_LENCHECKED|M_HASH|M_CKHASH|M_PRIO)
279 
280 /*
281  * Flags indicating hw checksum support and sw checksum requirements.
282  */
283 #define	CSUM_IP			0x0001		/* will csum IP */
284 #define	CSUM_TCP		0x0002		/* will csum TCP */
285 #define	CSUM_UDP		0x0004		/* will csum UDP */
286 #define	CSUM_IP_FRAGS		0x0008		/* will csum IP fragments */
287 #define	CSUM_FRAGMENT		0x0010		/* will do IP fragmentation */
288 
289 #define	CSUM_IP_CHECKED		0x0100		/* did csum IP */
290 #define	CSUM_IP_VALID		0x0200		/*   ... the csum is valid */
291 #define	CSUM_DATA_VALID		0x0400		/* csum_data field is valid */
292 #define	CSUM_PSEUDO_HDR		0x0800		/* csum_data has pseudo hdr */
293 #define CSUM_FRAG_NOT_CHECKED	0x1000		/* did _not_ csum fragment
294 						 * NB: This flag is only used
295 						 * by IP defragmenter.
296 						 */
297 #define CSUM_TSO		0x2000		/* will do TCP segmentation */
298 
299 #define	CSUM_DELAY_DATA		(CSUM_TCP | CSUM_UDP)
300 #define	CSUM_DELAY_IP		(CSUM_IP)	/* XXX add ipv6 here too? */
301 
302 /*
303  * Flags indicating PF processing status
304  */
305 #define FW_MBUF_GENERATED	0x00000001
306 #define	PF_MBUF_STRUCTURE	0x00000002	/* m_pkthdr.pf valid */
307 #define	PF_MBUF_ROUTED		0x00000004	/* pf_routed field is valid */
308 #define	PF_MBUF_TAGGED		0x00000008
309 #define	IPFW_MBUF_CONTINUE	0x00000010
310 #define	XX_MBUF_UNUSED20	0x00000020
311 #define IPFORWARD_MBUF_TAGGED	0x00000040
312 #define DUMMYNET_MBUF_TAGGED	0x00000080
313 #define BRIDGE_MBUF_TAGGED	0x00000100
314 #define FW_MBUF_REDISPATCH	0x00000200
315 #define	IPFW_MBUF_GENERATED	FW_MBUF_GENERATED
316 /*
317  * mbuf types.
318  */
319 #define	MT_FREE		0	/* should be on free list */
320 #define	MT_DATA		1	/* dynamic (data) allocation */
321 #define	MT_HEADER	2	/* packet header */
322 #define	MT_SONAME	3	/* socket name */
323 /* 4 was MT_TAG */
324 #define	MT_CONTROL	5	/* extra-data protocol message */
325 #define	MT_OOBDATA	6	/* expedited data  */
326 #define	MT_NTYPES	7	/* number of mbuf types for mbtypes[] */
327 
328 /*
329  * General mbuf allocator statistics structure.
330  *
331  * NOTE: Make sure this struct's size is multiple cache line size.
332  */
333 struct mbstat {
334 	u_long	m_mbufs;	/* mbufs obtained from page pool */
335 	u_long	m_clusters;	/* clusters obtained from page pool */
336 	u_long	m_jclusters;	/* jclusters obtained from page pool */
337 	u_long	m_clfree;	/* free clusters */
338 	u_long	m_drops;	/* times failed to find space */
339 	u_long	m_wait;		/* times waited for space */
340 	u_long	m_drain;	/* times drained protocols for space */
341 	u_long	m_mcfail;	/* times m_copym failed */
342 	u_long	m_mpfail;	/* times m_pullup failed */
343 	u_long	m_msize;	/* length of an mbuf */
344 	u_long	m_mclbytes;	/* length of an mbuf cluster */
345 	u_long	m_mjumpagesize;	/* length of a jumbo mbuf cluster */
346 	u_long	m_minclsize;	/* min length of data to allocate a cluster */
347 	u_long	m_mlen;		/* length of data in an mbuf */
348 	u_long	m_mhlen;	/* length of data in a header mbuf */
349 	u_long	m_pad;		/* pad to cache line size (64B) */
350 };
351 
352 /*
353  * objcache(9) ocflags sanitizing
354  */
355 #define	MB_OCFLAG(how)	((how) & M_WAITOK ? M_WAITOK : M_NOWAIT)
356 
357 /*
358  * These are identifying numbers passed to the m_mballoc_wait function,
359  * allowing us to determine whether the call came from an MGETHDR or
360  * an MGET.
361  */
362 #define	MGETHDR_C      1
363 #define	MGET_C         2
364 
365 /*
366  * mbuf allocation/deallocation macros (YYY deprecated, too big):
367  *
368  *	MGET(struct mbuf *m, int how, int type)
369  * allocates an mbuf and initializes it to contain internal data.
370  *
371  *	MGETHDR(struct mbuf *m, int how, int type)
372  * allocates an mbuf and initializes it to contain a packet header
373  * and internal data.
374  */
375 #define	MGET(m, how, type) do {						\
376 	(m) = m_get((how), (type));					\
377 } while (0)
378 
379 #define	MGETHDR(m, how, type) do {					\
380 	(m) = m_gethdr((how), (type));					\
381 } while (0)
382 
383 /*
384  * MCLGET adds such clusters to a normal mbuf.  The flag M_EXT is set upon
385  * success.
386  * Deprecated.  Use m_getcl() or m_getl() instead.
387  */
388 #define	MCLGET(m, how) do {						\
389 	m_mclget((m), (how));						\
390 } while (0)
391 
392 /*
393  * NB: M_COPY_PKTHDR is deprecated; use either M_MOVE_PKTHDR
394  *     or m_dup_pkthdr.
395  */
396 /*
397  * Move mbuf pkthdr from "from" to "to".
398  * from should have M_PKTHDR set, and to must be empty.
399  * from no longer has a pkthdr after this operation.
400  */
401 #define	M_MOVE_PKTHDR(_to, _from)	m_move_pkthdr((_to), (_from))
402 
403 /*
404  * Set the m_data pointer of a newly-allocated mbuf (m_get/MGET) to place
405  * an object of the specified size at the end of the mbuf, longword aligned.
406  */
407 #define	M_ALIGN(m, len) do {						\
408 	(m)->m_data += (MLEN - (len)) & ~(sizeof(long) - 1);		\
409 } while (0)
410 
411 /*
412  * As above, for mbufs allocated with m_gethdr/MGETHDR
413  * or initialized by M_COPY_PKTHDR.
414  */
415 #define	MH_ALIGN(m, len) do {						\
416 	(m)->m_data += (MHLEN - (len)) & ~(sizeof(long) - 1);		\
417 } while (0)
418 
419 /*
420  * Check if we can write to an mbuf.
421  */
422 #define M_EXT_WRITABLE(m)	(m_sharecount(m) == 1)
423 #define M_WRITABLE(m)		(!((m)->m_flags & M_EXT) || M_EXT_WRITABLE(m))
424 
425 /*
426  * Check if the supplied mbuf has a packet header, or else panic.
427  */
428 #define	M_ASSERTPKTHDR(m)						\
429 	KASSERT(m != NULL && m->m_flags & M_PKTHDR,			\
430 		("%s: invalid mbuf or no mbuf packet header!", __func__))
431 
432 /*
433  * Compute the amount of space available before the current start of data.
434  * The M_EXT_WRITABLE() is a temporary, conservative safety measure: the burden
435  * of checking writability of the mbuf data area rests solely with the caller.
436  */
437 #define	M_LEADINGSPACE(m)						\
438 	((m)->m_flags & M_EXT ?						\
439 	    (M_EXT_WRITABLE(m) ? (m)->m_data - (m)->m_ext.ext_buf : 0):	\
440 	    (m)->m_flags & M_PKTHDR ? (m)->m_data - (m)->m_pktdat :	\
441 	    (m)->m_data - (m)->m_dat)
442 
443 /*
444  * Compute the amount of space available after the end of data in an mbuf.
445  * The M_WRITABLE() is a temporary, conservative safety measure: the burden
446  * of checking writability of the mbuf data area rests solely with the caller.
447  */
448 #define	M_TRAILINGSPACE(m)						\
449 	((m)->m_flags & M_EXT ?						\
450 	    (M_WRITABLE(m) ? (m)->m_ext.ext_buf + (m)->m_ext.ext_size	\
451 		- ((m)->m_data + (m)->m_len) : 0) :			\
452 	    &(m)->m_dat[MLEN] - ((m)->m_data + (m)->m_len))
453 
454 /*
455  * Arrange to prepend space of size plen to mbuf m.
456  * If a new mbuf must be allocated, how specifies whether to wait.
457  * If how is M_NOWAIT and allocation fails, the original mbuf chain
458  * is freed and m is set to NULL.
459  */
460 #define	M_PREPEND(m, plen, how) do {					\
461 	struct mbuf **_mmp = &(m);					\
462 	struct mbuf *_mm = *_mmp;					\
463 	int _mplen = (plen);						\
464 	int __mhow = (how);						\
465 									\
466 	if (M_LEADINGSPACE(_mm) >= _mplen) {				\
467 		_mm->m_data -= _mplen;					\
468 		_mm->m_len += _mplen;					\
469 	} else								\
470 		_mm = m_prepend(_mm, _mplen, __mhow);			\
471 	if (_mm != NULL && (_mm->m_flags & M_PKTHDR))			\
472 		_mm->m_pkthdr.len += _mplen;				\
473 	*_mmp = _mm;							\
474 } while (0)
475 
476 /* Length to m_copy to copy all. */
477 #define	M_COPYALL	1000000000
478 
479 /* Compatibility with 4.3 */
480 #define	m_copy(m, o, l)	m_copym((m), (o), (l), M_NOWAIT)
481 
482 #ifdef _KERNEL
483 extern	u_int		 m_clalloc_wid;	/* mbuf cluster wait count */
484 extern	u_int		 m_mballoc_wid;	/* mbuf wait count */
485 extern	int		 max_linkhdr;	/* largest link-level header */
486 extern	int		 max_protohdr;	/* largest protocol header */
487 extern	int		 max_hdr;	/* largest link+protocol header */
488 extern	int		 max_datalen;	/* MHLEN - max_hdr */
489 extern	int		 mbuf_wait;	/* mbuf sleep time */
490 extern	int		 nmbclusters;
491 extern	int		 nmbufs;
492 
493 struct uio;
494 
495 void		 mcl_inclimit(int);
496 void		 mjcl_inclimit(int);
497 void		 mb_inclimit(int);
498 void		 m_adj(struct mbuf *, int);
499 void		 m_align(struct mbuf *, int);
500 int		 m_apply(struct mbuf *, int, int,
501 		    int (*)(void *, void *, u_int), void *);
502 int		m_append(struct mbuf *, int, c_caddr_t);
503 void		 m_cat(struct mbuf *, struct mbuf *);
504 u_int		 m_countm(struct mbuf *m, struct mbuf **lastm, u_int *mbcnt);
505 void		 m_copyback(struct mbuf *, int, int, caddr_t);
506 void		 m_copydata(const struct mbuf *, int, int, caddr_t);
507 struct	mbuf	*m_copym(const struct mbuf *, int, int, int);
508 struct	mbuf	*m_copypacket(struct mbuf *, int);
509 struct	mbuf	*m_defrag(struct mbuf *, int);
510 struct	mbuf	*m_defrag_nofree(struct mbuf *, int);
511 struct	mbuf	*m_devget(char *, int, int, struct ifnet *);
512 struct	mbuf	*m_dup(struct mbuf *, int);
513 struct	mbuf	*m_dup_data(struct mbuf *, int);
514 int		 m_dup_pkthdr(struct mbuf *, const struct mbuf *, int);
515 void		 m_extadd(struct mbuf *, caddr_t, u_int, void (*)(void *),
516 		  void (*)(void *), void *);
517 #ifdef MBUF_DEBUG
518 struct	mbuf	*_m_free(struct mbuf *, const char *name);
519 void		 _m_freem(struct mbuf *, const char *name);
520 #else
521 struct	mbuf	*m_free(struct mbuf *);
522 void		 m_freem(struct mbuf *);
523 #endif
524 struct	mbuf	*m_get(int, int);
525 struct	mbuf	*m_getc(int len, int how, int type);
526 struct	mbuf	*m_getcl(int how, short type, int flags);
527 struct	mbuf	*m_getjcl(int how, short type, int flags, size_t size);
528 struct	mbuf	*m_getclr(int, int);
529 struct	mbuf	*m_gethdr(int, int);
530 struct	mbuf	*m_getm(struct mbuf *, int, int, int);
531 struct	mbuf	*m_getptr(struct mbuf *, int, int *);
532 struct	mbuf	*m_last(struct mbuf *m);
533 u_int		 m_lengthm(struct mbuf *m, struct mbuf **lastm);
534 void		 m_move_pkthdr(struct mbuf *, struct mbuf *);
535 struct	mbuf	*m_prepend(struct mbuf *, int, int);
536 void		 m_print(const struct mbuf *m);
537 struct	mbuf	*m_pulldown(struct mbuf *, int, int, int *);
538 struct	mbuf	*m_pullup(struct mbuf *, int);
539 struct	mbuf	*m_split(struct mbuf *, int, int);
540 struct	mbuf 	*m_uiomove(struct uio *);
541 struct	mbuf	*m_unshare(struct mbuf *, int);
542 void		m_mclget(struct mbuf *m, int how);
543 int		m_sharecount(struct mbuf *m);
544 void		m_chtype(struct mbuf *m, int type);
545 int		m_devpad(struct mbuf *m, int padto);
546 
547 #ifdef MBUF_DEBUG
548 
549 void		mbuftrackid(struct mbuf *, int);
550 
551 #define m_free(m)	_m_free(m, __func__)
552 #define m_freem(m)	_m_freem(m, __func__)
553 
554 #else
555 
556 #define mbuftrackid(m, id)	/* empty */
557 
558 #endif
559 
560 static __inline void
561 m_sethash(struct mbuf *m, uint16_t hash)
562 {
563 	m->m_flags |= M_HASH;
564 	m->m_pkthdr.hash = hash;
565 }
566 
567 /*
568  * Allocate the right type of mbuf for the desired total length.
569  * The mbuf returned does not necessarily cover the entire requested length.
570  * This function follows mbuf chaining policy of allowing MINCLSIZE
571  * amount of chained mbufs.
572  */
573 static __inline struct mbuf *
574 m_getl(int len, int how, int type, int flags, int *psize)
575 {
576 	struct mbuf *m;
577 	int size;
578 
579 	if (len >= MINCLSIZE) {
580 		m = m_getcl(how, type, flags);
581 		size = MCLBYTES;
582 	} else if (flags & M_PKTHDR) {
583 		m = m_gethdr(how, type);
584 		size = MHLEN;
585 	} else {
586 		m = m_get(how, type);
587 		size = MLEN;
588 	}
589 	if (psize != NULL)
590 		*psize = size;
591 	return (m);
592 }
593 
594 static __inline struct mbuf *
595 m_getlj(int len, int how, int type, int flags, int *psize)
596 {
597 	if (len > MCLBYTES) {
598 		struct mbuf *m;
599 
600 		m = m_getjcl(how, type, flags, MJUMPAGESIZE);
601 		if (psize != NULL)
602 			*psize = MJUMPAGESIZE;
603 		return m;
604 	}
605 	return m_getl(len, how, type, flags, psize);
606 }
607 
608 /*
609  * Get a single mbuf that covers the requested number of bytes.
610  * This function does not create mbuf chains.  It explicitly marks
611  * places in the code that abuse mbufs for contiguous data buffers.
612  */
613 static __inline struct mbuf *
614 m_getb(int len, int how, int type, int flags)
615 {
616 	struct mbuf *m;
617 	int mbufsize = (flags & M_PKTHDR) ? MHLEN : MLEN;
618 
619 	if (len > mbufsize)
620 		m = m_getcl(how, type, flags);
621 	else if (flags & M_PKTHDR)
622 		m = m_gethdr(how, type);
623 	else
624 		m = m_get(how, type);
625 	return (m);
626 }
627 
628 /*
629  * Packets may have annotations attached by affixing a list
630  * of "packet tags" to the pkthdr structure.  Packet tags are
631  * dynamically allocated semi-opaque data structures that have
632  * a fixed header (struct m_tag) that specifies the size of the
633  * memory block and a <cookie,type> pair that identifies it.
634  * The cookie is a 32-bit unique unsigned value used to identify
635  * a module or ABI.  By convention this value is chose as the
636  * date+time that the module is created, expressed as the number of
637  * seconds since the epoch (e.g. using date -u +'%s').  The type value
638  * is an ABI/module-specific value that identifies a particular annotation
639  * and is private to the module.  For compatibility with systems
640  * like openbsd that define packet tags w/o an ABI/module cookie,
641  * the value PACKET_ABI_COMPAT is used to implement m_tag_get and
642  * m_tag_find compatibility shim functions and several tag types are
643  * defined below.  Users that do not require compatibility should use
644  * a private cookie value so that packet tag-related definitions
645  * can be maintained privately.
646  *
647  * Note that the packet tag returned by m_tag_alloc has the default
648  * memory alignment implemented by kmalloc.  To reference private data
649  * one can use a construct like:
650  *
651  *	struct m_tag *mtag = m_tag_alloc(...);
652  *	struct foo *p = m_tag_data(mtag);
653  *
654  * if the alignment of struct m_tag is sufficient for referencing members
655  * of struct foo.  Otherwise it is necessary to embed struct m_tag within
656  * the private data structure to insure proper alignment; e.g.
657  *
658  *	struct foo {
659  *		struct m_tag	tag;
660  *		...
661  *	};
662  *	struct foo *p = (struct foo *)m_tag_alloc(...);
663  *	struct m_tag *mtag = &p->tag;
664  */
665 
666 #define	PACKET_TAG_NONE				0  /* Nadda */
667 
668 /* Packet tag for use with PACKET_ABI_COMPAT */
669 #define	PACKET_TAG_IPSEC_IN_DONE		1  /* IPsec applied, in */
670 /* struct tdb_indent */
671 #define	PACKET_TAG_IPSEC_OUT_DONE		2  /* IPsec applied, out */
672 /* struct tdb_indent */
673 #define	PACKET_TAG_IPSEC_IN_CRYPTO_DONE		3  /* NIC IPsec crypto done */
674 /* struct tdb_indent, never added */
675 #define	PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED	4  /* NIC IPsec crypto req'ed */
676 /* struct tdb_indent, never added */
677 #define	PACKET_TAG_IPSEC_PENDING_TDB		5  /* Reminder to do IPsec */
678 /* struct tdb_indent, never added */
679 #define	PACKET_TAG_ENCAP			6 /* Encap.  processing */
680 /* struct ifnet *, the GIF interface */
681 #define	PACKET_TAG_IPSEC_HISTORY		7 /* IPSEC history */
682 /* struct ipsec_history */
683 #define	PACKET_TAG_IPV6_INPUT			8 /* IPV6 input processing */
684 /* struct ip6aux */
685 #define	PACKET_TAG_IPFW_DIVERT			9 /* divert info */
686 /* struct divert_info */
687 #define	PACKET_TAG_DUMMYNET			15 /* dummynet info */
688 /* struct dn_pkt */
689 #define	PACKET_TAG_IPFORWARD			18 /* ipforward info */
690 /* struct sockaddr_in */
691 #define PACKET_TAG_IPSRCRT			27 /* IP srcrt opts */
692 /* struct ip_srcrt_opt */
693 #define	PACKET_TAG_CARP                         28 /* CARP info */
694 /* struct pf_mtag */
695 #define PACKET_TAG_PF				29 /* PF info */
696 
697 #define PACKET_TAG_PF_DIVERT			0x0200 /* pf(4) diverted packet */
698 
699 
700 /* Packet tag routines */
701 struct	m_tag 	*m_tag_alloc(uint32_t, int, int, int);
702 void		 m_tag_free(struct m_tag *);
703 void		 m_tag_prepend(struct mbuf *, struct m_tag *);
704 void		 m_tag_unlink(struct mbuf *, struct m_tag *);
705 void		 m_tag_delete(struct mbuf *, struct m_tag *);
706 void		 m_tag_delete_chain(struct mbuf *);
707 struct	m_tag	*m_tag_locate(struct mbuf *, uint32_t, int, struct m_tag *);
708 struct	m_tag	*m_tag_copy(struct m_tag *, int);
709 int		 m_tag_copy_chain(struct mbuf *, const struct mbuf *, int);
710 void		 m_tag_init(struct mbuf *);
711 struct	m_tag	*m_tag_first(struct mbuf *);
712 struct	m_tag	*m_tag_next(struct mbuf *, struct m_tag *);
713 
714 /* these are for openbsd compatibility */
715 #define	MTAG_ABI_COMPAT		0		/* compatibility ABI */
716 
717 static __inline void *
718 m_tag_data(struct m_tag *tag)
719 {
720 	return ((void *)(tag + 1));
721 }
722 
723 static __inline struct m_tag *
724 m_tag_get(int type, int length, int mflags)
725 {
726 	return m_tag_alloc(MTAG_ABI_COMPAT, type, length, mflags);
727 }
728 
729 static __inline struct m_tag *
730 m_tag_find(struct mbuf *m, int type, struct m_tag *start)
731 {
732 	return m_tag_locate(m, MTAG_ABI_COMPAT, type, start);
733 }
734 
735 struct mbufq {
736 	STAILQ_HEAD(, mbuf)	mq_head;
737 	int			mq_len;
738 	int			mq_maxlen;
739 };
740 
741 static inline void
742 mbufq_init(struct mbufq *mq, int maxlen)
743 {
744 
745 	STAILQ_INIT(&mq->mq_head);
746 	mq->mq_maxlen = maxlen;
747 	mq->mq_len = 0;
748 }
749 
750 static inline struct mbuf *
751 mbufq_flush(struct mbufq *mq)
752 {
753 	struct mbuf *m;
754 
755 	m = STAILQ_FIRST(&mq->mq_head);
756 	STAILQ_INIT(&mq->mq_head);
757 	mq->mq_len = 0;
758 	return (m);
759 }
760 
761 static inline void
762 mbufq_drain(struct mbufq *mq)
763 {
764 	struct mbuf *m, *n;
765 
766 	n = mbufq_flush(mq);
767 	while ((m = n) != NULL) {
768 		n = STAILQ_NEXT(m, m_stailqpkt);
769 		m_freem(m);
770 	}
771 }
772 
773 static inline struct mbuf *
774 mbufq_first(const struct mbufq *mq)
775 {
776 
777 	return (STAILQ_FIRST(&mq->mq_head));
778 }
779 
780 static inline struct mbuf *
781 mbufq_last(const struct mbufq *mq)
782 {
783 
784 	return (STAILQ_LAST(&mq->mq_head, mbuf, m_stailqpkt));
785 }
786 
787 static inline int
788 mbufq_full(const struct mbufq *mq)
789 {
790 
791 	return (mq->mq_len >= mq->mq_maxlen);
792 }
793 
794 static inline int
795 mbufq_len(const struct mbufq *mq)
796 {
797 
798 	return (mq->mq_len);
799 }
800 
801 static inline int
802 mbufq_enqueue(struct mbufq *mq, struct mbuf *m)
803 {
804 
805 	if (mbufq_full(mq))
806 		return (ENOBUFS);
807 	STAILQ_INSERT_TAIL(&mq->mq_head, m, m_stailqpkt);
808 	mq->mq_len++;
809 	return (0);
810 }
811 
812 static inline struct mbuf *
813 mbufq_dequeue(struct mbufq *mq)
814 {
815 	struct mbuf *m;
816 
817 	m = STAILQ_FIRST(&mq->mq_head);
818 	if (m) {
819 		STAILQ_REMOVE_HEAD(&mq->mq_head, m_stailqpkt);
820 		m->m_nextpkt = NULL;
821 		mq->mq_len--;
822 	}
823 	return (m);
824 }
825 
826 static inline void
827 mbufq_prepend(struct mbufq *mq, struct mbuf *m)
828 {
829 
830 	STAILQ_INSERT_HEAD(&mq->mq_head, m, m_stailqpkt);
831 	mq->mq_len++;
832 }
833 
834 #endif	/* _KERNEL */
835 
836 #endif	/* _KERNEL || _KERNEL_STRUCTURES */
837 #endif	/* !_SYS_MBUF_H_ */
838