FreeBSD/Linux Kernel Cross Reference
sys/sys/mbuf.h
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: releng/9.0/sys/sys/mbuf.h 223637 2011-06-28 11:57:25Z bz $
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
287 #define CSUM_IP_CHECKED 0x0100 /* did csum IP */
288 #define CSUM_IP_VALID 0x0200 /* ... the csum is valid */
289 #define CSUM_DATA_VALID 0x0400 /* csum_data field is valid */
290 #define CSUM_PSEUDO_HDR 0x0800 /* csum_data has pseudo hdr */
291 #define CSUM_SCTP_VALID 0x1000 /* SCTP checksum is valid */
292
293 #define CSUM_DELAY_DATA (CSUM_TCP | CSUM_UDP)
294 #define CSUM_DELAY_IP (CSUM_IP) /* XXX add ipv6 here too? */
295
296 /*
297 * mbuf types.
298 */
299 #define MT_NOTMBUF 0 /* USED INTERNALLY ONLY! Object is not mbuf */
300 #define MT_DATA 1 /* dynamic (data) allocation */
301 #define MT_HEADER MT_DATA /* packet header, use M_PKTHDR instead */
302 #define MT_SONAME 8 /* socket name */
303 #define MT_CONTROL 14 /* extra-data protocol message */
304 #define MT_OOBDATA 15 /* expedited data */
305 #define MT_NTYPES 16 /* number of mbuf types for mbtypes[] */
306
307 #define MT_NOINIT 255 /* Not a type but a flag to allocate
308 a non-initialized mbuf */
309
310 #define MB_NOTAGS 0x1UL /* no tags attached to mbuf */
311
312 /*
313 * General mbuf allocator statistics structure.
314 *
315 * Many of these statistics are no longer used; we instead track many
316 * allocator statistics through UMA's built in statistics mechanism.
317 */
318 struct mbstat {
319 u_long m_mbufs; /* XXX */
320 u_long m_mclusts; /* XXX */
321
322 u_long m_drain; /* times drained protocols for space */
323 u_long m_mcfail; /* XXX: times m_copym failed */
324 u_long m_mpfail; /* XXX: times m_pullup failed */
325 u_long m_msize; /* length of an mbuf */
326 u_long m_mclbytes; /* length of an mbuf cluster */
327 u_long m_minclsize; /* min length of data to allocate a cluster */
328 u_long m_mlen; /* length of data in an mbuf */
329 u_long m_mhlen; /* length of data in a header mbuf */
330
331 /* Number of mbtypes (gives # elems in mbtypes[] array) */
332 short m_numtypes;
333
334 /* XXX: Sendfile stats should eventually move to their own struct */
335 u_long sf_iocnt; /* times sendfile had to do disk I/O */
336 u_long sf_allocfail; /* times sfbuf allocation failed */
337 u_long sf_allocwait; /* times sfbuf allocation had to wait */
338 };
339
340 /*
341 * Flags specifying how an allocation should be made.
342 *
343 * The flag to use is as follows:
344 * - M_DONTWAIT or M_NOWAIT from an interrupt handler to not block allocation.
345 * - M_WAIT or M_WAITOK from wherever it is safe to block.
346 *
347 * M_DONTWAIT/M_NOWAIT means that we will not block the thread explicitly and
348 * if we cannot allocate immediately we may return NULL, whereas
349 * M_WAIT/M_WAITOK means that if we cannot allocate resources we
350 * will block until they are available, and thus never return NULL.
351 *
352 * XXX Eventually just phase this out to use M_WAITOK/M_NOWAIT.
353 */
354 #define MBTOM(how) (how)
355 #define M_DONTWAIT M_NOWAIT
356 #define M_TRYWAIT M_WAITOK
357 #define M_WAIT M_WAITOK
358
359 /*
360 * String names of mbuf-related UMA(9) and malloc(9) types. Exposed to
361 * !_KERNEL so that monitoring tools can look up the zones with
362 * libmemstat(3).
363 */
364 #define MBUF_MEM_NAME "mbuf"
365 #define MBUF_CLUSTER_MEM_NAME "mbuf_cluster"
366 #define MBUF_PACKET_MEM_NAME "mbuf_packet"
367 #define MBUF_JUMBOP_MEM_NAME "mbuf_jumbo_page"
368 #define MBUF_JUMBO9_MEM_NAME "mbuf_jumbo_9k"
369 #define MBUF_JUMBO16_MEM_NAME "mbuf_jumbo_16k"
370 #define MBUF_TAG_MEM_NAME "mbuf_tag"
371 #define MBUF_EXTREFCNT_MEM_NAME "mbuf_ext_refcnt"
372
373 #ifdef _KERNEL
374
375 #ifdef WITNESS
376 #define MBUF_CHECKSLEEP(how) do { \
377 if (how == M_WAITOK) \
378 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, \
379 "Sleeping in \"%s\"", __func__); \
380 } while (0)
381 #else
382 #define MBUF_CHECKSLEEP(how)
383 #endif
384
385 /*
386 * Network buffer allocation API
387 *
388 * The rest of it is defined in kern/kern_mbuf.c
389 */
390
391 extern uma_zone_t zone_mbuf;
392 extern uma_zone_t zone_clust;
393 extern uma_zone_t zone_pack;
394 extern uma_zone_t zone_jumbop;
395 extern uma_zone_t zone_jumbo9;
396 extern uma_zone_t zone_jumbo16;
397 extern uma_zone_t zone_ext_refcnt;
398
399 static __inline struct mbuf *m_getcl(int how, short type, int flags);
400 static __inline struct mbuf *m_get(int how, short type);
401 static __inline struct mbuf *m_gethdr(int how, short type);
402 static __inline struct mbuf *m_getjcl(int how, short type, int flags,
403 int size);
404 static __inline struct mbuf *m_getclr(int how, short type); /* XXX */
405 static __inline int m_init(struct mbuf *m, uma_zone_t zone,
406 int size, int how, short type, int flags);
407 static __inline struct mbuf *m_free(struct mbuf *m);
408 static __inline void m_clget(struct mbuf *m, int how);
409 static __inline void *m_cljget(struct mbuf *m, int how, int size);
410 static __inline void m_chtype(struct mbuf *m, short new_type);
411 void mb_free_ext(struct mbuf *);
412 static __inline struct mbuf *m_last(struct mbuf *m);
413 int m_pkthdr_init(struct mbuf *m, int how);
414
415 static __inline int
416 m_gettype(int size)
417 {
418 int type;
419
420 switch (size) {
421 case MSIZE:
422 type = EXT_MBUF;
423 break;
424 case MCLBYTES:
425 type = EXT_CLUSTER;
426 break;
427 #if MJUMPAGESIZE != MCLBYTES
428 case MJUMPAGESIZE:
429 type = EXT_JUMBOP;
430 break;
431 #endif
432 case MJUM9BYTES:
433 type = EXT_JUMBO9;
434 break;
435 case MJUM16BYTES:
436 type = EXT_JUMBO16;
437 break;
438 default:
439 panic("%s: m_getjcl: invalid cluster size", __func__);
440 }
441
442 return (type);
443 }
444
445 static __inline uma_zone_t
446 m_getzone(int size)
447 {
448 uma_zone_t zone;
449
450 switch (size) {
451 case MSIZE:
452 zone = zone_mbuf;
453 break;
454 case MCLBYTES:
455 zone = zone_clust;
456 break;
457 #if MJUMPAGESIZE != MCLBYTES
458 case MJUMPAGESIZE:
459 zone = zone_jumbop;
460 break;
461 #endif
462 case MJUM9BYTES:
463 zone = zone_jumbo9;
464 break;
465 case MJUM16BYTES:
466 zone = zone_jumbo16;
467 break;
468 default:
469 panic("%s: m_getjcl: invalid cluster type", __func__);
470 }
471
472 return (zone);
473 }
474
475 /*
476 * Initialize an mbuf with linear storage.
477 *
478 * Inline because the consumer text overhead will be roughly the same to
479 * initialize or call a function with this many parameters and M_PKTHDR
480 * should go away with constant propagation for !MGETHDR.
481 */
482 static __inline int
483 m_init(struct mbuf *m, uma_zone_t zone, int size, int how, short type,
484 int flags)
485 {
486 int error;
487
488 m->m_next = NULL;
489 m->m_nextpkt = NULL;
490 m->m_data = m->m_dat;
491 m->m_len = 0;
492 m->m_flags = flags;
493 m->m_type = type;
494 if (flags & M_PKTHDR) {
495 if ((error = m_pkthdr_init(m, how)) != 0)
496 return (error);
497 }
498
499 return (0);
500 }
501
502 static __inline struct mbuf *
503 m_get(int how, short type)
504 {
505 struct mb_args args;
506
507 args.flags = 0;
508 args.type = type;
509 return ((struct mbuf *)(uma_zalloc_arg(zone_mbuf, &args, how)));
510 }
511
512 /*
513 * XXX This should be deprecated, very little use.
514 */
515 static __inline struct mbuf *
516 m_getclr(int how, short type)
517 {
518 struct mbuf *m;
519 struct mb_args args;
520
521 args.flags = 0;
522 args.type = type;
523 m = uma_zalloc_arg(zone_mbuf, &args, how);
524 if (m != NULL)
525 bzero(m->m_data, MLEN);
526 return (m);
527 }
528
529 static __inline struct mbuf *
530 m_gethdr(int how, short type)
531 {
532 struct mb_args args;
533
534 args.flags = M_PKTHDR;
535 args.type = type;
536 return ((struct mbuf *)(uma_zalloc_arg(zone_mbuf, &args, how)));
537 }
538
539 static __inline struct mbuf *
540 m_getcl(int how, short type, int flags)
541 {
542 struct mb_args args;
543
544 args.flags = flags;
545 args.type = type;
546 return ((struct mbuf *)(uma_zalloc_arg(zone_pack, &args, how)));
547 }
548
549 /*
550 * m_getjcl() returns an mbuf with a cluster of the specified size attached.
551 * For size it takes MCLBYTES, MJUMPAGESIZE, MJUM9BYTES, MJUM16BYTES.
552 *
553 * XXX: This is rather large, should be real function maybe.
554 */
555 static __inline struct mbuf *
556 m_getjcl(int how, short type, int flags, int size)
557 {
558 struct mb_args args;
559 struct mbuf *m, *n;
560 uma_zone_t zone;
561
562 if (size == MCLBYTES)
563 return m_getcl(how, type, flags);
564
565 args.flags = flags;
566 args.type = type;
567
568 m = uma_zalloc_arg(zone_mbuf, &args, how);
569 if (m == NULL)
570 return (NULL);
571
572 zone = m_getzone(size);
573 n = uma_zalloc_arg(zone, m, how);
574 if (n == NULL) {
575 uma_zfree(zone_mbuf, m);
576 return (NULL);
577 }
578 return (m);
579 }
580
581 static __inline void
582 m_free_fast(struct mbuf *m)
583 {
584 #ifdef INVARIANTS
585 if (m->m_flags & M_PKTHDR)
586 KASSERT(SLIST_EMPTY(&m->m_pkthdr.tags), ("doing fast free of mbuf with tags"));
587 #endif
588
589 uma_zfree_arg(zone_mbuf, m, (void *)MB_NOTAGS);
590 }
591
592 static __inline struct mbuf *
593 m_free(struct mbuf *m)
594 {
595 struct mbuf *n = m->m_next;
596
597 if (m->m_flags & M_EXT)
598 mb_free_ext(m);
599 else if ((m->m_flags & M_NOFREE) == 0)
600 uma_zfree(zone_mbuf, m);
601 return (n);
602 }
603
604 static __inline void
605 m_clget(struct mbuf *m, int how)
606 {
607
608 if (m->m_flags & M_EXT)
609 printf("%s: %p mbuf already has cluster\n", __func__, m);
610 m->m_ext.ext_buf = (char *)NULL;
611 uma_zalloc_arg(zone_clust, m, how);
612 /*
613 * On a cluster allocation failure, drain the packet zone and retry,
614 * we might be able to loosen a few clusters up on the drain.
615 */
616 if ((how & M_NOWAIT) && (m->m_ext.ext_buf == NULL)) {
617 zone_drain(zone_pack);
618 uma_zalloc_arg(zone_clust, m, how);
619 }
620 }
621
622 /*
623 * m_cljget() is different from m_clget() as it can allocate clusters without
624 * attaching them to an mbuf. In that case the return value is the pointer
625 * to the cluster of the requested size. If an mbuf was specified, it gets
626 * the cluster attached to it and the return value can be safely ignored.
627 * For size it takes MCLBYTES, MJUMPAGESIZE, MJUM9BYTES, MJUM16BYTES.
628 */
629 static __inline void *
630 m_cljget(struct mbuf *m, int how, int size)
631 {
632 uma_zone_t zone;
633
634 if (m && m->m_flags & M_EXT)
635 printf("%s: %p mbuf already has cluster\n", __func__, m);
636 if (m != NULL)
637 m->m_ext.ext_buf = NULL;
638
639 zone = m_getzone(size);
640 return (uma_zalloc_arg(zone, m, how));
641 }
642
643 static __inline void
644 m_cljset(struct mbuf *m, void *cl, int type)
645 {
646 uma_zone_t zone;
647 int size;
648
649 switch (type) {
650 case EXT_CLUSTER:
651 size = MCLBYTES;
652 zone = zone_clust;
653 break;
654 #if MJUMPAGESIZE != MCLBYTES
655 case EXT_JUMBOP:
656 size = MJUMPAGESIZE;
657 zone = zone_jumbop;
658 break;
659 #endif
660 case EXT_JUMBO9:
661 size = MJUM9BYTES;
662 zone = zone_jumbo9;
663 break;
664 case EXT_JUMBO16:
665 size = MJUM16BYTES;
666 zone = zone_jumbo16;
667 break;
668 default:
669 panic("unknown cluster type");
670 break;
671 }
672
673 m->m_data = m->m_ext.ext_buf = cl;
674 m->m_ext.ext_free = m->m_ext.ext_arg1 = m->m_ext.ext_arg2 = NULL;
675 m->m_ext.ext_size = size;
676 m->m_ext.ext_type = type;
677 m->m_ext.ref_cnt = uma_find_refcnt(zone, cl);
678 m->m_flags |= M_EXT;
679
680 }
681
682 static __inline void
683 m_chtype(struct mbuf *m, short new_type)
684 {
685
686 m->m_type = new_type;
687 }
688
689 static __inline struct mbuf *
690 m_last(struct mbuf *m)
691 {
692
693 while (m->m_next)
694 m = m->m_next;
695 return (m);
696 }
697
698 extern void (*m_addr_chg_pf_p)(struct mbuf *m);
699
700 static __inline void
701 m_addr_changed(struct mbuf *m)
702 {
703
704 if (m_addr_chg_pf_p)
705 m_addr_chg_pf_p(m);
706 }
707
708 /*
709 * mbuf, cluster, and external object allocation macros (for compatibility
710 * purposes).
711 */
712 #define M_MOVE_PKTHDR(to, from) m_move_pkthdr((to), (from))
713 #define MGET(m, how, type) ((m) = m_get((how), (type)))
714 #define MGETHDR(m, how, type) ((m) = m_gethdr((how), (type)))
715 #define MCLGET(m, how) m_clget((m), (how))
716 #define MEXTADD(m, buf, size, free, arg1, arg2, flags, type) \
717 m_extadd((m), (caddr_t)(buf), (size), (free),(arg1),(arg2),(flags), (type))
718 #define m_getm(m, len, how, type) \
719 m_getm2((m), (len), (how), (type), M_PKTHDR)
720
721 /*
722 * Evaluate TRUE if it's safe to write to the mbuf m's data region (this can
723 * be both the local data payload, or an external buffer area, depending on
724 * whether M_EXT is set).
725 */
726 #define M_WRITABLE(m) (!((m)->m_flags & M_RDONLY) && \
727 (!(((m)->m_flags & M_EXT)) || \
728 (*((m)->m_ext.ref_cnt) == 1)) ) \
729
730 /* Check if the supplied mbuf has a packet header, or else panic. */
731 #define M_ASSERTPKTHDR(m) \
732 KASSERT((m) != NULL && (m)->m_flags & M_PKTHDR, \
733 ("%s: no mbuf packet header!", __func__))
734
735 /*
736 * Ensure that the supplied mbuf is a valid, non-free mbuf.
737 *
738 * XXX: Broken at the moment. Need some UMA magic to make it work again.
739 */
740 #define M_ASSERTVALID(m) \
741 KASSERT((((struct mbuf *)m)->m_flags & 0) == 0, \
742 ("%s: attempted use of a free mbuf!", __func__))
743
744 /*
745 * Set the m_data pointer of a newly-allocated mbuf (m_get/MGET) to place an
746 * object of the specified size at the end of the mbuf, longword aligned.
747 */
748 #define M_ALIGN(m, len) do { \
749 KASSERT(!((m)->m_flags & (M_PKTHDR|M_EXT)), \
750 ("%s: M_ALIGN not normal mbuf", __func__)); \
751 KASSERT((m)->m_data == (m)->m_dat, \
752 ("%s: M_ALIGN not a virgin mbuf", __func__)); \
753 (m)->m_data += (MLEN - (len)) & ~(sizeof(long) - 1); \
754 } while (0)
755
756 /*
757 * As above, for mbufs allocated with m_gethdr/MGETHDR or initialized by
758 * M_DUP/MOVE_PKTHDR.
759 */
760 #define MH_ALIGN(m, len) do { \
761 KASSERT((m)->m_flags & M_PKTHDR && !((m)->m_flags & M_EXT), \
762 ("%s: MH_ALIGN not PKTHDR mbuf", __func__)); \
763 KASSERT((m)->m_data == (m)->m_pktdat, \
764 ("%s: MH_ALIGN not a virgin mbuf", __func__)); \
765 (m)->m_data += (MHLEN - (len)) & ~(sizeof(long) - 1); \
766 } while (0)
767
768 /*
769 * Compute the amount of space available before the current start of data in
770 * an mbuf.
771 *
772 * The M_WRITABLE() is a temporary, conservative safety measure: the burden
773 * of checking writability of the mbuf data area rests solely with the caller.
774 */
775 #define M_LEADINGSPACE(m) \
776 ((m)->m_flags & M_EXT ? \
777 (M_WRITABLE(m) ? (m)->m_data - (m)->m_ext.ext_buf : 0): \
778 (m)->m_flags & M_PKTHDR ? (m)->m_data - (m)->m_pktdat : \
779 (m)->m_data - (m)->m_dat)
780
781 /*
782 * Compute the amount of space available after the end of data in an mbuf.
783 *
784 * The M_WRITABLE() is a temporary, conservative safety measure: the burden
785 * of checking writability of the mbuf data area rests solely with the caller.
786 */
787 #define M_TRAILINGSPACE(m) \
788 ((m)->m_flags & M_EXT ? \
789 (M_WRITABLE(m) ? (m)->m_ext.ext_buf + (m)->m_ext.ext_size \
790 - ((m)->m_data + (m)->m_len) : 0) : \
791 &(m)->m_dat[MLEN] - ((m)->m_data + (m)->m_len))
792
793 /*
794 * Arrange to prepend space of size plen to mbuf m. If a new mbuf must be
795 * allocated, how specifies whether to wait. If the allocation fails, the
796 * original mbuf chain is freed and m is set to NULL.
797 */
798 #define M_PREPEND(m, plen, how) do { \
799 struct mbuf **_mmp = &(m); \
800 struct mbuf *_mm = *_mmp; \
801 int _mplen = (plen); \
802 int __mhow = (how); \
803 \
804 MBUF_CHECKSLEEP(how); \
805 if (M_LEADINGSPACE(_mm) >= _mplen) { \
806 _mm->m_data -= _mplen; \
807 _mm->m_len += _mplen; \
808 } else \
809 _mm = m_prepend(_mm, _mplen, __mhow); \
810 if (_mm != NULL && _mm->m_flags & M_PKTHDR) \
811 _mm->m_pkthdr.len += _mplen; \
812 *_mmp = _mm; \
813 } while (0)
814
815 /*
816 * Change mbuf to new type. This is a relatively expensive operation and
817 * should be avoided.
818 */
819 #define MCHTYPE(m, t) m_chtype((m), (t))
820
821 /* Length to m_copy to copy all. */
822 #define M_COPYALL 1000000000
823
824 /* Compatibility with 4.3. */
825 #define m_copy(m, o, l) m_copym((m), (o), (l), M_DONTWAIT)
826
827 extern int max_datalen; /* MHLEN - max_hdr */
828 extern int max_hdr; /* Largest link + protocol header */
829 extern int max_linkhdr; /* Largest link-level header */
830 extern int max_protohdr; /* Largest protocol header */
831 extern struct mbstat mbstat; /* General mbuf stats/infos */
832 extern int nmbclusters; /* Maximum number of clusters */
833
834 struct uio;
835
836 void m_adj(struct mbuf *, int);
837 void m_align(struct mbuf *, int);
838 int m_apply(struct mbuf *, int, int,
839 int (*)(void *, void *, u_int), void *);
840 int m_append(struct mbuf *, int, c_caddr_t);
841 void m_cat(struct mbuf *, struct mbuf *);
842 void m_extadd(struct mbuf *, caddr_t, u_int,
843 void (*)(void *, void *), void *, void *, int, int);
844 struct mbuf *m_collapse(struct mbuf *, int, int);
845 void m_copyback(struct mbuf *, int, int, c_caddr_t);
846 void m_copydata(const struct mbuf *, int, int, caddr_t);
847 struct mbuf *m_copym(struct mbuf *, int, int, int);
848 struct mbuf *m_copymdata(struct mbuf *, struct mbuf *,
849 int, int, int, int);
850 struct mbuf *m_copypacket(struct mbuf *, int);
851 void m_copy_pkthdr(struct mbuf *, struct mbuf *);
852 struct mbuf *m_copyup(struct mbuf *n, int len, int dstoff);
853 struct mbuf *m_defrag(struct mbuf *, int);
854 void m_demote(struct mbuf *, int);
855 struct mbuf *m_devget(char *, int, int, struct ifnet *,
856 void (*)(char *, caddr_t, u_int));
857 struct mbuf *m_dup(struct mbuf *, int);
858 int m_dup_pkthdr(struct mbuf *, struct mbuf *, int);
859 u_int m_fixhdr(struct mbuf *);
860 struct mbuf *m_fragment(struct mbuf *, int, int);
861 void m_freem(struct mbuf *);
862 struct mbuf *m_getm2(struct mbuf *, int, int, short, int);
863 struct mbuf *m_getptr(struct mbuf *, int, int *);
864 u_int m_length(struct mbuf *, struct mbuf **);
865 int m_mbuftouio(struct uio *, struct mbuf *, int);
866 void m_move_pkthdr(struct mbuf *, struct mbuf *);
867 struct mbuf *m_prepend(struct mbuf *, int, int);
868 void m_print(const struct mbuf *, int);
869 struct mbuf *m_pulldown(struct mbuf *, int, int, int *);
870 struct mbuf *m_pullup(struct mbuf *, int);
871 int m_sanity(struct mbuf *, int);
872 struct mbuf *m_split(struct mbuf *, int, int);
873 struct mbuf *m_uiotombuf(struct uio *, int, int, int, int);
874 struct mbuf *m_unshare(struct mbuf *, int how);
875
876 /*-
877 * Network packets may have annotations attached by affixing a list of
878 * "packet tags" to the pkthdr structure. Packet tags are dynamically
879 * allocated semi-opaque data structures that have a fixed header
880 * (struct m_tag) that specifies the size of the memory block and a
881 * <cookie,type> pair that identifies it. The cookie is a 32-bit unique
882 * unsigned value used to identify a module or ABI. By convention this value
883 * is chosen as the date+time that the module is created, expressed as the
884 * number of seconds since the epoch (e.g., using date -u +'%s'). The type
885 * value is an ABI/module-specific value that identifies a particular
886 * annotation and is private to the module. For compatibility with systems
887 * like OpenBSD that define packet tags w/o an ABI/module cookie, the value
888 * PACKET_ABI_COMPAT is used to implement m_tag_get and m_tag_find
889 * compatibility shim functions and several tag types are defined below.
890 * Users that do not require compatibility should use a private cookie value
891 * so that packet tag-related definitions can be maintained privately.
892 *
893 * Note that the packet tag returned by m_tag_alloc has the default memory
894 * alignment implemented by malloc. To reference private data one can use a
895 * construct like:
896 *
897 * struct m_tag *mtag = m_tag_alloc(...);
898 * struct foo *p = (struct foo *)(mtag+1);
899 *
900 * if the alignment of struct m_tag is sufficient for referencing members of
901 * struct foo. Otherwise it is necessary to embed struct m_tag within the
902 * private data structure to insure proper alignment; e.g.,
903 *
904 * struct foo {
905 * struct m_tag tag;
906 * ...
907 * };
908 * struct foo *p = (struct foo *) m_tag_alloc(...);
909 * struct m_tag *mtag = &p->tag;
910 */
911
912 /*
913 * Persistent tags stay with an mbuf until the mbuf is reclaimed. Otherwise
914 * tags are expected to ``vanish'' when they pass through a network
915 * interface. For most interfaces this happens normally as the tags are
916 * reclaimed when the mbuf is free'd. However in some special cases
917 * reclaiming must be done manually. An example is packets that pass through
918 * the loopback interface. Also, one must be careful to do this when
919 * ``turning around'' packets (e.g., icmp_reflect).
920 *
921 * To mark a tag persistent bit-or this flag in when defining the tag id.
922 * The tag will then be treated as described above.
923 */
924 #define MTAG_PERSISTENT 0x800
925
926 #define PACKET_TAG_NONE 0 /* Nadda */
927
928 /* Packet tags for use with PACKET_ABI_COMPAT. */
929 #define PACKET_TAG_IPSEC_IN_DONE 1 /* IPsec applied, in */
930 #define PACKET_TAG_IPSEC_OUT_DONE 2 /* IPsec applied, out */
931 #define PACKET_TAG_IPSEC_IN_CRYPTO_DONE 3 /* NIC IPsec crypto done */
932 #define PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED 4 /* NIC IPsec crypto req'ed */
933 #define PACKET_TAG_IPSEC_IN_COULD_DO_CRYPTO 5 /* NIC notifies IPsec */
934 #define PACKET_TAG_IPSEC_PENDING_TDB 6 /* Reminder to do IPsec */
935 #define PACKET_TAG_BRIDGE 7 /* Bridge processing done */
936 #define PACKET_TAG_GIF 8 /* GIF processing done */
937 #define PACKET_TAG_GRE 9 /* GRE processing done */
938 #define PACKET_TAG_IN_PACKET_CHECKSUM 10 /* NIC checksumming done */
939 #define PACKET_TAG_ENCAP 11 /* Encap. processing */
940 #define PACKET_TAG_IPSEC_SOCKET 12 /* IPSEC socket ref */
941 #define PACKET_TAG_IPSEC_HISTORY 13 /* IPSEC history */
942 #define PACKET_TAG_IPV6_INPUT 14 /* IPV6 input processing */
943 #define PACKET_TAG_DUMMYNET 15 /* dummynet info */
944 #define PACKET_TAG_DIVERT 17 /* divert info */
945 #define PACKET_TAG_IPFORWARD 18 /* ipforward info */
946 #define PACKET_TAG_MACLABEL (19 | MTAG_PERSISTENT) /* MAC label */
947 #define PACKET_TAG_PF 21 /* PF + ALTQ information */
948 #define PACKET_TAG_RTSOCKFAM 25 /* rtsock sa family */
949 #define PACKET_TAG_IPOPTIONS 27 /* Saved IP options */
950 #define PACKET_TAG_CARP 28 /* CARP info */
951 #define PACKET_TAG_IPSEC_NAT_T_PORTS 29 /* two uint16_t */
952 #define PACKET_TAG_ND_OUTGOING 30 /* ND outgoing */
953
954 /* Specific cookies and tags. */
955
956 /* Packet tag routines. */
957 struct m_tag *m_tag_alloc(u_int32_t, int, int, int);
958 void m_tag_delete(struct mbuf *, struct m_tag *);
959 void m_tag_delete_chain(struct mbuf *, struct m_tag *);
960 void m_tag_free_default(struct m_tag *);
961 struct m_tag *m_tag_locate(struct mbuf *, u_int32_t, int, struct m_tag *);
962 struct m_tag *m_tag_copy(struct m_tag *, int);
963 int m_tag_copy_chain(struct mbuf *, struct mbuf *, int);
964 void m_tag_delete_nonpersistent(struct mbuf *);
965
966 /*
967 * Initialize the list of tags associated with an mbuf.
968 */
969 static __inline void
970 m_tag_init(struct mbuf *m)
971 {
972
973 SLIST_INIT(&m->m_pkthdr.tags);
974 }
975
976 /*
977 * Set up the contents of a tag. Note that this does not fill in the free
978 * method; the caller is expected to do that.
979 *
980 * XXX probably should be called m_tag_init, but that was already taken.
981 */
982 static __inline void
983 m_tag_setup(struct m_tag *t, u_int32_t cookie, int type, int len)
984 {
985
986 t->m_tag_id = type;
987 t->m_tag_len = len;
988 t->m_tag_cookie = cookie;
989 }
990
991 /*
992 * Reclaim resources associated with a tag.
993 */
994 static __inline void
995 m_tag_free(struct m_tag *t)
996 {
997
998 (*t->m_tag_free)(t);
999 }
1000
1001 /*
1002 * Return the first tag associated with an mbuf.
1003 */
1004 static __inline struct m_tag *
1005 m_tag_first(struct mbuf *m)
1006 {
1007
1008 return (SLIST_FIRST(&m->m_pkthdr.tags));
1009 }
1010
1011 /*
1012 * Return the next tag in the list of tags associated with an mbuf.
1013 */
1014 static __inline struct m_tag *
1015 m_tag_next(struct mbuf *m, struct m_tag *t)
1016 {
1017
1018 return (SLIST_NEXT(t, m_tag_link));
1019 }
1020
1021 /*
1022 * Prepend a tag to the list of tags associated with an mbuf.
1023 */
1024 static __inline void
1025 m_tag_prepend(struct mbuf *m, struct m_tag *t)
1026 {
1027
1028 SLIST_INSERT_HEAD(&m->m_pkthdr.tags, t, m_tag_link);
1029 }
1030
1031 /*
1032 * Unlink a tag from the list of tags associated with an mbuf.
1033 */
1034 static __inline void
1035 m_tag_unlink(struct mbuf *m, struct m_tag *t)
1036 {
1037
1038 SLIST_REMOVE(&m->m_pkthdr.tags, t, m_tag, m_tag_link);
1039 }
1040
1041 /* These are for OpenBSD compatibility. */
1042 #define MTAG_ABI_COMPAT 0 /* compatibility ABI */
1043
1044 static __inline struct m_tag *
1045 m_tag_get(int type, int length, int wait)
1046 {
1047 return (m_tag_alloc(MTAG_ABI_COMPAT, type, length, wait));
1048 }
1049
1050 static __inline struct m_tag *
1051 m_tag_find(struct mbuf *m, int type, struct m_tag *start)
1052 {
1053 return (SLIST_EMPTY(&m->m_pkthdr.tags) ? (struct m_tag *)NULL :
1054 m_tag_locate(m, MTAG_ABI_COMPAT, type, start));
1055 }
1056
1057 /* XXX temporary FIB methods probably eventually use tags.*/
1058 #define M_FIBSHIFT 28
1059 #define M_FIBMASK 0x0F
1060
1061 /* get the fib from an mbuf and if it is not set, return the default */
1062 #define M_GETFIB(_m) \
1063 ((((_m)->m_flags & M_FIB) >> M_FIBSHIFT) & M_FIBMASK)
1064
1065 #define M_SETFIB(_m, _fib) do { \
1066 _m->m_flags &= ~M_FIB; \
1067 _m->m_flags |= (((_fib) << M_FIBSHIFT) & M_FIB); \
1068 } while (0)
1069
1070 #endif /* _KERNEL */
1071
1072 #ifdef MBUF_PROFILING
1073 void m_profile(struct mbuf *m);
1074 #define M_PROFILE(m) m_profile(m)
1075 #else
1076 #define M_PROFILE(m)
1077 #endif
1078
1079
1080 #endif /* !_SYS_MBUF_H_ */
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