xref: /dragonfly/sys/sys/mbuf.h (revision 7485684f)
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, which includes overhead.
58  * An mbuf may add a single "mbuf cluster" of size MCLBYTES, which has
59  * no additional overhead and is used instead of the internal data area;
60  * this is done when at least MINCLSIZE of data must be stored.
61  */
62 #define	MLEN		(MSIZE - sizeof(struct m_hdr))	/* normal data len */
63 #define	MHLEN		(MLEN - sizeof(struct pkthdr))	/* data len w/pkthdr */
64 #define	MINCLSIZE	(MHLEN + 1)	/* smallest amount to put in cluster */
65 #define	M_MAXCOMPRESS	(MHLEN / 2)	/* max amount to copy for compression */
66 
67 /*
68  * Macros for type conversion:
69  * mtod(m, t)		-- Convert mbuf pointer to data pointer of correct type.
70  * mtodoff(m, t, off)	-- Convert mbuf pointer at the specified offset to data
71  *			   pointer of correct type.
72  */
73 #define	mtod(m, t)		((t)((m)->m_data))
74 #define	mtodoff(m, t, off)	((t)((m)->m_data + (off)))
75 
76 /*
77  * Header present at the beginning of every mbuf.
78  */
79 struct m_hdr {
80 	struct	mbuf *mh_next;		/* next buffer in chain */
81 	union {
82 		struct	mbuf *mh_nextpkt; /* next chain in queue/record */
83 		STAILQ_ENTRY(mbuf) mh_stailqpkt;
84 	};
85 	caddr_t	mh_data;		/* location of data */
86 	int	mh_len;			/* amount of data in this mbuf */
87 	int	mh_flags;		/* flags; see below */
88 	short	mh_type;		/* type of data in this mbuf */
89 	short	mh_pad;			/* padding */
90 	/* XXX implicit 4 bytes padding on x86_64 */
91 #ifdef MBUF_DEBUG
92 	const char *mh_lastfunc;
93 #endif
94 	union {
95 		struct netmsg_packet mhm_pkt;	/* hardware->proto stack msg */
96 		struct netmsg_pru_send mhm_snd;	/* usrspace->proto stack msg */
97 		struct netmsg_inarp mhm_arp;	/* proto stack arpinput msg */
98 		struct netmsg_ctlinput mhm_ctl;	/* proto stack ctlinput msg */
99 		struct netmsg_genpkt mhm_gen;	/* generic pkt send/recv msg */
100 		struct netmsg_forward mhm_fwd;	/* forwarding 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 #define mh_fwdmsg	mh_msgu.mhm_fwd
109 
110 /* pf stuff */
111 struct pkthdr_pf {
112 	void		*hdr;		/* saved hdr pos in mbuf, for ECN */
113 	void		*statekey;	/* pf stackside statekey */
114 	u_int		rtableid;	/* alternate routing table id */
115 	uint32_t	qid;		/* queue id */
116 	uint16_t	tag;		/* tag id */
117 	uint8_t		flags;
118 	uint8_t		routed;
119 	uint32_t	state_hash;	/* identifies 'connections' */
120 	uint8_t		ecn_af;		/* for altq_red */
121 	uint8_t		unused01;
122 	uint8_t		unused02;
123 	uint8_t		unused03;
124 	/* XXX implicit 4 bytes padding on x86_64 */
125 };
126 
127 /* pkthdr_pf.flags */
128 #define	PF_TAG_GENERATED		0x01
129 #define	PF_TAG_FRAGCACHE		0x02
130 #define	PF_TAG_TRANSLATE_LOCALHOST	0x04
131 #define	PF_TAG_DIVERTED			0x08
132 #define	PF_TAG_DIVERTED_PACKET		0x10
133 #define	PF_TAG_REROUTE			0x20
134 
135 /*
136  * Packet tag structure (see below for details).
137  */
138 struct m_tag {
139 	SLIST_ENTRY(m_tag)	m_tag_link;	/* List of packet tags */
140 	uint16_t		m_tag_id;	/* Tag ID */
141 	uint16_t		m_tag_len;	/* Length of data */
142 	uint32_t		m_tag_cookie;	/* ABI/Module ID */
143 };
144 
145 SLIST_HEAD(packet_tags, m_tag);
146 
147 /*
148  * Record/packet header in first mbuf of chain; valid only if M_PKTHDR is set.
149  *
150  * Be careful: The fields have been carefully ordered to avoid hidden padding.
151  *             Keep this in mind, when adding or removing fields!
152  */
153 struct pkthdr {
154 	struct ifnet *rcvif;		/* rcv interface */
155 	struct packet_tags tags;	/* list of packet tags */
156 
157 	/* variables for ip and tcp reassembly */
158 	void	*header;		/* pointer to packet header */
159 	int	len;			/* total packet length */
160 
161 	/* variables for hardware checksum */
162 	int	csum_flags;		/* flags regarding checksum */
163 	int	csum_data;		/* data field used by csum routines */
164 	uint16_t csum_iphlen;		/* IP header length */
165 					/* valid if CSUM IP|UDP|TCP|TSO */
166 	uint8_t	csum_thlen;		/* TCP/UDP header length */
167 					/* valid if CSUM UDP|TCP|TSO */
168 	uint8_t	csum_lhlen;		/* link header length */
169 
170 	uint16_t tso_segsz;		/* TSO segment size */
171 	uint16_t ether_vlantag;		/* ethernet 802.1p+q vlan tag */
172 
173 	uint16_t hash;			/* packet hash */
174 	uint16_t unused1;		/* reserved for route table id */
175 	uint32_t unused2;		/* reserved for CoDel timestamp */
176 
177 	uint16_t wlan_seqno;		/* IEEE 802.11 seq no. */
178 	/*
179 	 * Valid if BRIDGE_MBUF_TAGGED is set in fw_flags, records
180 	 * the original ether source address (if compatible).
181 	 */
182 	uint8_t ether_br_shost[ETHER_ADDR_LEN];
183 
184 	/* firewall flags */
185 	uint32_t fw_flags;		/* flags for FW */
186 
187 	/* variables for PF processing */
188 	struct pkthdr_pf pf;		/* structure for PF */
189 };
190 
191 /*
192  * Description of external storage mapped into mbuf; valid only if M_EXT is set.
193  */
194 struct m_ext {
195 	caddr_t	ext_buf;		/* start of buffer */
196 	void	(*ext_free)(void *);
197 	u_int	ext_size;		/* size of buffer, for ext_free */
198 	void	(*ext_ref)(void *);
199 	void	*ext_arg;
200 };
201 
202 /*
203  * The core of the mbuf object along with some shortcut defines for
204  * practical purposes.
205  */
206 struct mbuf {
207 	struct	m_hdr m_hdr;
208 	union {
209 		struct {
210 			struct	pkthdr MH_pkthdr;	/* M_PKTHDR set */
211 			union {
212 				struct	m_ext MH_ext;	/* M_EXT set */
213 				char	MH_databuf[MHLEN];
214 			} MH_dat;
215 		} MH;
216 		char	M_databuf[MLEN];		/* !M_PKTHDR, !M_EXT */
217 	} M_dat;
218 };
219 #define	m_next		m_hdr.mh_next
220 #define	m_len		m_hdr.mh_len
221 #define	m_data		m_hdr.mh_data
222 #define	m_type		m_hdr.mh_type
223 #define	m_flags		m_hdr.mh_flags
224 #define	m_nextpkt	m_hdr.mh_nextpkt
225 #define	m_stailqpkt	m_hdr.mh_stailqpkt
226 #define	m_pkthdr	M_dat.MH.MH_pkthdr
227 #define	m_ext		M_dat.MH.MH_dat.MH_ext
228 #define	m_pktdat	M_dat.MH.MH_dat.MH_databuf
229 #define	m_dat		M_dat.M_databuf
230 
231 /*
232  * Code that uses m_act should be converted to use m_nextpkt
233  * instead; m_act is historical and deprecated.
234  */
235 #define m_act   	m_nextpkt
236 
237 /*
238  * mbuf flags.
239  */
240 #define	M_EXT		0x0001	/* has associated external storage */
241 #define	M_PKTHDR	0x0002	/* start of record */
242 #define	M_EOR		0x0004	/* end of record */
243 #define	M_PROTO1	0x0008	/* protocol-specific */
244 #define	M_PROTO2	0x0010	/* protocol-specific */
245 #define	M_PROTO3	0x0020	/* protocol-specific */
246 #define	M_PROTO4	0x0040	/* protocol-specific */
247 #define	M_PROTO5	0x0080	/* protocol-specific */
248 
249 /*
250  * mbuf pkthdr flags (also stored in m_flags).
251  */
252 #define	M_BCAST		0x0100	/* send/received as link-level broadcast */
253 #define	M_MCAST		0x0200	/* send/received as link-level multicast */
254 #define	M_FRAG		0x0400	/* packet is a fragment of a larger packet */
255 #define	M_FIRSTFRAG	0x0800	/* packet is first fragment */
256 #define	M_LASTFRAG	0x1000	/* packet is last fragment */
257 #define	M_CLCACHE	0x2000	/* mbuf allocated from the cluster cache */
258 #define	M_EXT_CLUSTER	0x4000	/* standard cluster else special */
259 #define	M_PHCACHE	0x8000	/* mbuf allocated from the pkt header cache */
260 #define	M_UNUSED16	0x10000	/* was: notification event (SCTP) */
261 #define	M_VLANTAG	0x20000	/* ether_vlantag is valid */
262 #define	M_MPLSLABELED	0x40000	/* packet is mpls labeled */
263 #define	M_LENCHECKED	0x80000	/* packet proto lengths are checked */
264 #define	M_HASH		0x100000	/* hash field in pkthdr is valid */
265 #define	M_PROTO6	0x200000	/* protocol-specific */
266 #define	M_PROTO7	0x400000	/* protocol-specific */
267 #define	M_PROTO8	0x800000	/* protocol-specific */
268 #define	M_CKHASH	0x1000000	/* hash needs software verification */
269 #define	M_PRIO		0x2000000	/* high priority mbuf */
270 #define	M_SOLOCKED	0x4000000	/* locked by userland for read() */
271 
272 /*
273  * Flags to purge when crossing layers.
274  */
275 #define	M_PROTOFLAGS	(M_PROTO1|M_PROTO2|M_PROTO3|M_PROTO4|M_PROTO5 | \
276 			 M_PROTO6|M_PROTO7|M_PROTO8)
277 
278 /*
279  * Flags copied when copying m_pkthdr.
280  */
281 #define	M_COPYFLAGS	(M_PKTHDR|M_EOR|M_PROTOFLAGS | \
282 			 M_BCAST|M_MCAST|M_FRAG|M_FIRSTFRAG|M_LASTFRAG | \
283 			 M_VLANTAG|M_MPLSLABELED | \
284 			 M_LENCHECKED|M_HASH|M_CKHASH|M_PRIO)
285 
286 /*
287  * Flags indicating hw checksum support and sw checksum requirements.
288  */
289 #define	CSUM_IP			0x0001		/* will csum IP */
290 #define	CSUM_TCP		0x0002		/* will csum TCP */
291 #define	CSUM_UDP		0x0004		/* will csum UDP */
292 #define	CSUM_IP_FRAGS		0x0008		/* will csum IP fragments */
293 #define	CSUM_FRAGMENT		0x0010		/* will do IP fragmentation */
294 
295 #define	CSUM_IP_CHECKED		0x0100		/* did csum IP */
296 #define	CSUM_IP_VALID		0x0200		/*   ... the csum is valid */
297 #define	CSUM_DATA_VALID		0x0400		/* csum_data field is valid */
298 #define	CSUM_PSEUDO_HDR		0x0800		/* csum_data has pseudo hdr */
299 #define CSUM_FRAG_NOT_CHECKED	0x1000		/* did _not_ csum fragment
300 						 * NB: This flag is only used
301 						 * by IP defragmenter.
302 						 */
303 #define	CSUM_TSO		0x2000		/* will do TCP segmentation */
304 
305 #define	CSUM_DELAY_DATA		(CSUM_TCP | CSUM_UDP)
306 #define	CSUM_DELAY_IP		(CSUM_IP)	/* XXX add ipv6 here too? */
307 
308 /*
309  * Flags indicating PF processing status
310  */
311 #define	FW_MBUF_GENERATED	0x00000001
312 #define	PF_MBUF_STRUCTURE	0x00000002	/* m_pkthdr.pf valid */
313 #define	PF_MBUF_ROUTED		0x00000004	/* pf_routed field is valid */
314 #define	PF_MBUF_TAGGED		0x00000008
315 #define	IPFW_MBUF_CONTINUE	0x00000010
316 #define	XX_MBUF_UNUSED20	0x00000020
317 #define	IPFORWARD_MBUF_TAGGED	0x00000040
318 #define	DUMMYNET_MBUF_TAGGED	0x00000080
319 #define	BRIDGE_MBUF_TAGGED	0x00000100
320 #define	FW_MBUF_REDISPATCH	0x00000200
321 #define	FW_MBUF_PRIVATE1	0x00000400
322 #define	FW_MBUF_PRIVATE2	0x00000800
323 #define	IPFW_MBUF_GENERATED	FW_MBUF_GENERATED
324 
325 /*
326  * mbuf types.
327  */
328 #define	MT_FREE		0	/* should be on free list */
329 #define	MT_DATA		1	/* dynamic (data) allocation */
330 #define	MT_HEADER	2	/* packet header */
331 #define	MT_SONAME	3	/* socket name */
332 /* 4 was MT_TAG */
333 #define	MT_CONTROL	5	/* extra-data protocol message */
334 #define	MT_OOBDATA	6	/* expedited data  */
335 #define	MT_NTYPES	7	/* number of mbuf types for mbtypes[] */
336 
337 /*
338  * General mbuf allocator statistics structure.
339  *
340  * NOTE: Make sure this struct's size is multiple cache line size.
341  */
342 struct mbstat {
343 	u_long	m_mbufs;	/* mbufs obtained from page pool */
344 	u_long	m_clusters;	/* clusters obtained from page pool */
345 	u_long	m_jclusters;	/* jclusters obtained from page pool */
346 	u_long	m_clfree;	/* free clusters */
347 	u_long	m_drops;	/* times failed to find space */
348 	u_long	m_wait;		/* times waited for space */
349 	u_long	m_drain;	/* times drained protocols for space */
350 	u_long	m_mcfail;	/* times m_copym failed */
351 	u_long	m_mpfail;	/* times m_pullup failed */
352 	u_long	m_msize;	/* length of an mbuf */
353 	u_long	m_mclbytes;	/* length of an mbuf cluster */
354 	u_long	m_mjumpagesize;	/* length of a jumbo mbuf cluster */
355 	u_long	m_minclsize;	/* min length of data to allocate a cluster */
356 	u_long	m_mlen;		/* length of data in an mbuf */
357 	u_long	m_mhlen;	/* length of data in a header mbuf */
358 	u_long	m_pad;		/* pad to cache line size (64B) */
359 };
360 
361 /*
362  * objcache(9) ocflags sanitizing
363  */
364 #define	MB_OCFLAG(how)	((how) & M_WAITOK ? M_WAITOK : M_NOWAIT)
365 
366 /*
367  * These are identifying numbers passed to the m_mballoc_wait function,
368  * allowing us to determine whether the call came from an MGETHDR or
369  * an MGET.
370  */
371 #define	MGETHDR_C      1
372 #define	MGET_C         2
373 
374 /*
375  * mbuf allocation/deallocation macros (YYY deprecated, too big):
376  *
377  *	MGET(struct mbuf *m, int how, int type)
378  * allocates an mbuf and initializes it to contain internal data.
379  *
380  *	MGETHDR(struct mbuf *m, int how, int type)
381  * allocates an mbuf and initializes it to contain a packet header
382  * and internal data.
383  */
384 #define	MGET(m, how, type) do {						\
385 	(m) = m_get((how), (type));					\
386 } while (0)
387 
388 #define	MGETHDR(m, how, type) do {					\
389 	(m) = m_gethdr((how), (type));					\
390 } while (0)
391 
392 /*
393  * MCLGET adds such clusters to a normal mbuf.  The flag M_EXT is set upon
394  * success.
395  * Deprecated.  Use m_getcl() or m_getl() instead.
396  */
397 #define	MCLGET(m, how) do {						\
398 	m_mclget((m), (how));						\
399 } while (0)
400 
401 /*
402  * NB: M_COPY_PKTHDR is deprecated; use either M_MOVE_PKTHDR
403  *     or m_dup_pkthdr.
404  */
405 /*
406  * Move mbuf pkthdr from "from" to "to".
407  * from should have M_PKTHDR set, and to must be empty.
408  * from no longer has a pkthdr after this operation.
409  */
410 #define	M_MOVE_PKTHDR(_to, _from)	m_move_pkthdr((_to), (_from))
411 
412 /*
413  * Set the m_data pointer of a newly-allocated mbuf (m_get/MGET) to place
414  * an object of the specified size at the end of the mbuf, longword aligned.
415  */
416 #define	M_ALIGN(m, len) do {						\
417 	(m)->m_data += rounddown2(MLEN - (len), sizeof(long));		\
418 } while (0)
419 
420 /*
421  * As above, for mbufs allocated with m_gethdr/MGETHDR
422  * or initialized by M_COPY_PKTHDR.
423  */
424 #define	MH_ALIGN(m, len) do {						\
425 	(m)->m_data += rounddown2(MHLEN - (len), sizeof(long));		\
426 } while (0)
427 
428 /*
429  * Check if we can write to an mbuf.
430  */
431 #define	M_EXT_WRITABLE(m)	(m_sharecount(m) == 1)
432 #define	M_WRITABLE(m)		(!((m)->m_flags & M_EXT) || M_EXT_WRITABLE(m))
433 
434 /*
435  * Check if the supplied mbuf has a packet header, or else panic.
436  */
437 #define	M_ASSERTPKTHDR(m)						\
438 	KASSERT(m != NULL && m->m_flags & M_PKTHDR,			\
439 		("%s: invalid mbuf or no mbuf packet header!", __func__))
440 
441 /*
442  * Compute the amount of space available before the current start of data.
443  * The M_EXT_WRITABLE() is a temporary, conservative safety measure: the burden
444  * of checking writability of the mbuf data area rests solely with the caller.
445  */
446 #define	M_LEADINGSPACE(m)						\
447 	((m)->m_flags & M_EXT ?						\
448 	    (M_EXT_WRITABLE(m) ? (m)->m_data - (m)->m_ext.ext_buf : 0):	\
449 	    (m)->m_flags & M_PKTHDR ? (m)->m_data - (m)->m_pktdat :	\
450 	    (m)->m_data - (m)->m_dat)
451 
452 /*
453  * Compute the amount of space available after the end of data in an mbuf.
454  * The M_WRITABLE() is a temporary, conservative safety measure: the burden
455  * of checking writability of the mbuf data area rests solely with the caller.
456  */
457 #define	M_TRAILINGSPACE(m)						\
458 	((m)->m_flags & M_EXT ?						\
459 	    (M_WRITABLE(m) ? (m)->m_ext.ext_buf + (m)->m_ext.ext_size	\
460 		- ((m)->m_data + (m)->m_len) : 0) :			\
461 	    &(m)->m_dat[MLEN] - ((m)->m_data + (m)->m_len))
462 
463 /*
464  * Arrange to prepend space of size plen to mbuf m.
465  * If a new mbuf must be allocated, how specifies whether to wait.
466  * If how is M_NOWAIT and allocation fails, the original mbuf chain
467  * is freed and m is set to NULL.
468  */
469 #define	M_PREPEND(m, plen, how) do {					\
470 	struct mbuf **_mmp = &(m);					\
471 	struct mbuf *_mm = *_mmp;					\
472 	int _mplen = (plen);						\
473 	int __mhow = (how);						\
474 									\
475 	if (M_LEADINGSPACE(_mm) >= _mplen) {				\
476 		_mm->m_data -= _mplen;					\
477 		_mm->m_len += _mplen;					\
478 	} else								\
479 		_mm = m_prepend(_mm, _mplen, __mhow);			\
480 	if (_mm != NULL && (_mm->m_flags & M_PKTHDR))			\
481 		_mm->m_pkthdr.len += _mplen;				\
482 	*_mmp = _mm;							\
483 } while (0)
484 
485 /* Length to m_copym() to copy all. */
486 #define	M_COPYALL	1000000000
487 
488 /* Compatibility with 4.3 */
489 #define	m_copy(m, o, l)	m_copym((m), (o), (l), M_NOWAIT)
490 
491 #ifdef _KERNEL
492 
493 extern	u_int		 m_clalloc_wid;	/* mbuf cluster wait count */
494 extern	u_int		 m_mballoc_wid;	/* mbuf wait count */
495 extern	int		 max_linkhdr;	/* largest link-level header */
496 extern	int		 max_protohdr;	/* largest protocol header */
497 extern	int		 max_hdr;	/* largest link+protocol header */
498 extern	int		 max_datalen;	/* MHLEN - max_hdr */
499 extern	int		 nmbclusters;
500 extern	int		 nmbufs;
501 
502 struct uio;
503 
504 void		 mcl_inclimit(int);
505 void		 mjcl_inclimit(int);
506 void		 mb_inclimit(int);
507 void		 m_adj(struct mbuf *, int);
508 void		 m_align(struct mbuf *, int);
509 int		 m_apply(struct mbuf *, int, int,
510 		    int (*)(void *, void *, u_int), void *);
511 int		 m_append(struct mbuf *, int, const void *);
512 void		 m_cat(struct mbuf *, struct mbuf *);
513 u_int		 m_countm(struct mbuf *m, struct mbuf **lastm, u_int *mbcnt);
514 void		 m_copyback(struct mbuf *, int, int, const void *);
515 int		 m_copyback2(struct mbuf *, int, int, const void *, int);
516 void		 m_copydata(const struct mbuf *, int, int, void *);
517 struct	mbuf	*m_copym(const struct mbuf *, int, int, int);
518 struct	mbuf	*m_copypacket(struct mbuf *, int);
519 struct	mbuf	*m_defrag(struct mbuf *, int);
520 struct	mbuf	*m_defrag_nofree(struct mbuf *, int);
521 struct	mbuf	*m_devget(void *, int, int, struct ifnet *);
522 struct	mbuf	*m_dup(struct mbuf *, int);
523 struct	mbuf	*m_dup_data(struct mbuf *, int);
524 int		 m_dup_pkthdr(struct mbuf *, const struct mbuf *, int);
525 void		 m_extadd(struct mbuf *, void *, u_int, void (*)(void *),
526 		    void (*)(void *), void *);
527 #ifdef MBUF_DEBUG
528 struct	mbuf	*_m_free(struct mbuf *, const char *name);
529 void		 _m_freem(struct mbuf *, const char *name);
530 #else
531 struct	mbuf	*m_free(struct mbuf *);
532 void		 m_freem(struct mbuf *);
533 #endif
534 struct	mbuf	*m_get(int, int);
535 struct	mbuf	*m_getc(int len, int how, int type);
536 struct	mbuf	*m_getcl(int how, short type, int flags);
537 struct	mbuf	*m_getjcl(int how, short type, int flags, size_t size);
538 struct	mbuf	*m_getclr(int, int);
539 struct	mbuf	*m_gethdr(int, int);
540 struct	mbuf	*m_getm(struct mbuf *, int, int, int);
541 struct	mbuf	*m_getptr(struct mbuf *, int, int *);
542 struct	mbuf	*m_last(struct mbuf *m);
543 u_int		 m_lengthm(struct mbuf *m, struct mbuf **lastm);
544 void		 m_move_pkthdr(struct mbuf *, struct mbuf *);
545 struct	mbuf	*m_prepend(struct mbuf *, int, int);
546 void		 m_print(const struct mbuf *m);
547 struct	mbuf	*m_pulldown(struct mbuf *, int, int, int *);
548 struct	mbuf	*m_pullup(struct mbuf *, int);
549 struct	mbuf	*m_split(struct mbuf *, int, int);
550 struct	mbuf 	*m_uiomove(struct uio *);
551 struct	mbuf	*m_unshare(struct mbuf *, int);
552 void		m_mclget(struct mbuf *m, int how);
553 int		m_sharecount(struct mbuf *m);
554 void		m_chtype(struct mbuf *m, int type);
555 int		m_devpad(struct mbuf *m, int padto);
556 
557 #ifdef MBUF_DEBUG
558 
559 void		mbuftrackid(struct mbuf *, int);
560 
561 #define m_free(m)	_m_free(m, __func__)
562 #define m_freem(m)	_m_freem(m, __func__)
563 
564 #else
565 
566 #define mbuftrackid(m, id)	/* empty */
567 
568 #endif
569 
570 static __inline void
571 m_sethash(struct mbuf *m, uint16_t hash)
572 {
573 	m->m_flags |= M_HASH;
574 	m->m_pkthdr.hash = hash;
575 }
576 
577 /*
578  * Allocate the right type of mbuf for the desired total length.
579  * The mbuf returned does not necessarily cover the entire requested length.
580  * This function follows mbuf chaining policy of allowing MINCLSIZE
581  * amount of chained mbufs.
582  */
583 static __inline struct mbuf *
584 m_getl(int len, int how, int type, int flags, int *psize)
585 {
586 	struct mbuf *m;
587 	int size;
588 
589 	if (len >= MINCLSIZE) {
590 		m = m_getcl(how, type, flags);
591 		size = MCLBYTES;
592 	} else if (flags & M_PKTHDR) {
593 		m = m_gethdr(how, type);
594 		size = MHLEN;
595 	} else {
596 		m = m_get(how, type);
597 		size = MLEN;
598 	}
599 	if (psize != NULL)
600 		*psize = size;
601 	return (m);
602 }
603 
604 static __inline struct mbuf *
605 m_getlj(int len, int how, int type, int flags, int *psize)
606 {
607 	if (len > MCLBYTES) {
608 		struct mbuf *m;
609 
610 		m = m_getjcl(how, type, flags, MJUMPAGESIZE);
611 		if (psize != NULL)
612 			*psize = MJUMPAGESIZE;
613 		return m;
614 	}
615 	return m_getl(len, how, type, flags, psize);
616 }
617 
618 /*
619  * Get a single mbuf that covers the requested number of bytes.
620  * This function does not create mbuf chains.  It explicitly marks
621  * places in the code that abuse mbufs for contiguous data buffers.
622  */
623 static __inline struct mbuf *
624 m_getb(int len, int how, int type, int flags)
625 {
626 	struct mbuf *m;
627 	int mbufsize = (flags & M_PKTHDR) ? MHLEN : MLEN;
628 
629 	if (len > mbufsize)
630 		m = m_getcl(how, type, flags);
631 	else if (flags & M_PKTHDR)
632 		m = m_gethdr(how, type);
633 	else
634 		m = m_get(how, type);
635 	return (m);
636 }
637 
638 
639 /*
640  * Mbuf tags
641  *
642  * Packets may have annotations attached by affixing a list
643  * of "packet tags" to the pkthdr structure.  Packet tags are
644  * dynamically allocated semi-opaque data structures that have
645  * a fixed header (struct m_tag) that specifies the size of the
646  * memory block and a <cookie,type> pair that identifies it.
647  * The cookie is a 32-bit unique unsigned value used to identify
648  * a module or ABI.  By convention this value is chose as the
649  * date+time that the module is created, expressed as the number of
650  * seconds since the epoch (e.g. using date -u +'%s').  The type value
651  * is an ABI/module-specific value that identifies a particular annotation
652  * and is private to the module.  For compatibility with systems
653  * like openbsd that define packet tags w/o an ABI/module cookie,
654  * the value PACKET_ABI_COMPAT is used to implement m_tag_get and
655  * m_tag_find compatibility shim functions and several tag types are
656  * defined below.  Users that do not require compatibility should use
657  * a private cookie value so that packet tag-related definitions
658  * can be maintained privately.
659  *
660  * Note that the packet tag returned by m_tag_alloc has the default
661  * memory alignment implemented by kmalloc.  To reference private data
662  * one can use a construct like:
663  *
664  *	struct m_tag *mtag = m_tag_alloc(...);
665  *	struct foo *p = m_tag_data(mtag);
666  *
667  * if the alignment of struct m_tag is sufficient for referencing members
668  * of struct foo.  Otherwise it is necessary to embed struct m_tag within
669  * the private data structure to insure proper alignment; e.g.
670  *
671  *	struct foo {
672  *		struct m_tag	tag;
673  *		...
674  *	};
675  *	struct foo *p = (struct foo *)m_tag_alloc(...);
676  *	struct m_tag *mtag = &p->tag;
677  */
678 
679 #define	PACKET_TAG_NONE		0  /* Nadda */
680 #define	PACKET_TAG_ENCAP	6 /* Encap. processing */
681 				/* struct ifnet *, the GIF interface */
682 #define	PACKET_TAG_IPV6_INPUT	8 /* IPV6 input processing */
683 				/* struct ip6aux */
684 #define	PACKET_TAG_IPFW_DIVERT	9 /* divert info */
685 				/* struct divert_info */
686 #define	PACKET_TAG_DUMMYNET	15 /* dummynet info */
687 				/* struct dn_pkt */
688 #define	PACKET_TAG_IPFORWARD	18 /* ipforward info */
689 				/* struct sockaddr_in */
690 #define PACKET_TAG_IPSRCRT	27 /* IP srcrt opts */
691 				/* struct ip_srcrt_opt */
692 #define	PACKET_TAG_CARP		28 /* CARP info */
693 				/* struct ifnet */
694 #define	PACKET_TAG_PF		29 /* PF info */
695 				/* struct pf_mtag */
696 #define	PACKET_TAG_PF_DIVERT	0x0200 /* pf(4) diverted packet */
697 
698 /* Packet tag routines */
699 struct	m_tag 	*m_tag_alloc(uint32_t, int, int, int);
700 void		 m_tag_free(struct m_tag *);
701 void		 m_tag_prepend(struct mbuf *, struct m_tag *);
702 void		 m_tag_unlink(struct mbuf *, struct m_tag *);
703 void		 m_tag_delete(struct mbuf *, struct m_tag *);
704 void		 m_tag_delete_chain(struct mbuf *);
705 struct	m_tag	*m_tag_locate(struct mbuf *, uint32_t, int, struct m_tag *);
706 struct	m_tag	*m_tag_copy(struct m_tag *, int);
707 int		 m_tag_copy_chain(struct mbuf *, const struct mbuf *, int);
708 void		 m_tag_init(struct mbuf *);
709 struct	m_tag	*m_tag_first(struct mbuf *);
710 struct	m_tag	*m_tag_next(struct mbuf *, struct m_tag *);
711 
712 /* these are for openbsd compatibility */
713 #define	MTAG_ABI_COMPAT		0		/* compatibility ABI */
714 
715 static __inline void *
716 m_tag_data(struct m_tag *tag)
717 {
718 	return ((void *)(tag + 1));
719 }
720 
721 static __inline struct m_tag *
722 m_tag_get(int type, int length, int mflags)
723 {
724 	return m_tag_alloc(MTAG_ABI_COMPAT, type, length, mflags);
725 }
726 
727 static __inline struct m_tag *
728 m_tag_find(struct mbuf *m, int type, struct m_tag *start)
729 {
730 	return m_tag_locate(m, MTAG_ABI_COMPAT, type, start);
731 }
732 
733 
734 /*
735  * Mbuf queue routines
736  */
737 
738 struct mbufq {
739 	STAILQ_HEAD(, mbuf)	mq_head;
740 	int			mq_len;
741 	int			mq_maxlen;
742 };
743 
744 static inline void
745 mbufq_init(struct mbufq *mq, int maxlen)
746 {
747 	STAILQ_INIT(&mq->mq_head);
748 	mq->mq_maxlen = maxlen;
749 	mq->mq_len = 0;
750 }
751 
752 static inline struct mbuf *
753 mbufq_flush(struct mbufq *mq)
754 {
755 	struct mbuf *m;
756 
757 	m = STAILQ_FIRST(&mq->mq_head);
758 	STAILQ_INIT(&mq->mq_head);
759 	mq->mq_len = 0;
760 	return (m);
761 }
762 
763 static inline void
764 mbufq_drain(struct mbufq *mq)
765 {
766 	struct mbuf *m, *n;
767 
768 	n = mbufq_flush(mq);
769 	while ((m = n) != NULL) {
770 		n = STAILQ_NEXT(m, m_stailqpkt);
771 		m_freem(m);
772 	}
773 }
774 
775 static inline struct mbuf *
776 mbufq_first(const struct mbufq *mq)
777 {
778 	return (STAILQ_FIRST(&mq->mq_head));
779 }
780 
781 static inline struct mbuf *
782 mbufq_last(const struct mbufq *mq)
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 	return (mq->mq_len >= mq->mq_maxlen);
791 }
792 
793 static inline int
794 mbufq_len(const struct mbufq *mq)
795 {
796 	return (mq->mq_len);
797 }
798 
799 static inline int
800 mbufq_enqueue(struct mbufq *mq, struct mbuf *m)
801 {
802 	if (mbufq_full(mq))
803 		return (ENOBUFS);
804 	STAILQ_INSERT_TAIL(&mq->mq_head, m, m_stailqpkt);
805 	mq->mq_len++;
806 	return (0);
807 }
808 
809 static inline struct mbuf *
810 mbufq_dequeue(struct mbufq *mq)
811 {
812 	struct mbuf *m;
813 
814 	m = STAILQ_FIRST(&mq->mq_head);
815 	if (m) {
816 		STAILQ_REMOVE_HEAD(&mq->mq_head, m_stailqpkt);
817 		m->m_nextpkt = NULL;
818 		mq->mq_len--;
819 	}
820 	return (m);
821 }
822 
823 static inline void
824 mbufq_prepend(struct mbufq *mq, struct mbuf *m)
825 {
826 	STAILQ_INSERT_HEAD(&mq->mq_head, m, m_stailqpkt);
827 	mq->mq_len++;
828 }
829 
830 #endif	/* _KERNEL */
831 
832 #endif	/* _KERNEL || _KERNEL_STRUCTURES */
833 #endif	/* !_SYS_MBUF_H_ */
834