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Diffstat (limited to 'include/sys/mbuf.h')
-rw-r--r-- | include/sys/mbuf.h | 437 |
1 files changed, 437 insertions, 0 deletions
diff --git a/include/sys/mbuf.h b/include/sys/mbuf.h new file mode 100644 index 0000000000..48e9e40c2e --- /dev/null +++ b/include/sys/mbuf.h @@ -0,0 +1,437 @@ +/* + * Copyright (c) 1982, 1986, 1988, 1993 + * The Regents of the University of California. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of the University nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * @(#)mbuf.h 8.5 (Berkeley) 2/19/95 + * $FreeBSD: src/sys/sys/mbuf.h,v 1.169 2005/03/17 19:34:57 jmg Exp $ + */ + + +#ifndef _SYS_MBUF_H_ +#define _SYS_MBUF_H_ + +#ifndef M_WAITOK +#include <sys/malloc.h> +#endif + +/* + * Mbufs are of a single size, MSIZE (machine/machparam.h), which + * includes overhead. An mbuf may add a single "mbuf cluster" of size + * MCLBYTES (also in machine/machparam.h), which has no additional overhead + * and is used instead of the internal data area; this is done when + * at least MINCLSIZE of data must be stored. + */ + +#define MLEN (MSIZE - sizeof(struct m_hdr)) /* normal data len */ +#define MHLEN (MLEN - sizeof(struct pkthdr)) /* data len w/pkthdr */ +#define MINCLSIZE (MHLEN + MLEN) /* smallest amount to put in cluster */ +#define M_MAXCOMPRESS (MHLEN / 2) /* max amount to copy for compression */ + +/*- + * Macros for type conversion: + * mtod(m, t) -- Convert mbuf pointer to data pointer of correct type. + * dtom(x) -- Convert data pointer within mbuf to mbuf pointer (XXX). + * mtocl(x) -- Convert pointer within cluster to cluster index # + * cltom(x) -- Convert cluster # to ptr to beginning of cluster + */ +#define mtod(m, t) ((t)((m)->m_data)) +#define dtom(x) ((struct mbuf *)((intptr_t)(x) & ~(MSIZE-1))) +#define mtocl(x) (((uintptr_t)(x) - (uintptr_t)mbutl) >> MCLSHIFT) +#define cltom(x) ((caddr_t)((u_long)mbutl + ((u_long)(x) << MCLSHIFT))) + +/* + * Header present at the beginning of every mbuf. + */ +struct m_hdr { + struct mbuf *mh_next; /* next buffer in chain */ + struct mbuf *mh_nextpkt; /* next chain in queue/record */ + caddr_t mh_data; /* location of data */ + int mh_len; /* amount of data in this mbuf */ + int mh_flags; /* flags; see below */ + short mh_type; /* type of data in this mbuf */ +}; + +/* + * Record/packet header in first mbuf of chain; valid only if M_PKTHDR is set. + */ +struct pkthdr { + struct ifnet *rcvif; /* rcv interface */ + int32_t len; /* total packet length */ +}; + +/* + * Description of external storage mapped into mbuf; valid only if M_EXT is set. + */ +struct m_ext { + caddr_t ext_buf; /* start of buffer */ + void (*ext_free) /* free routine if not the usual */ + (caddr_t, u_int); + u_int ext_size; /* size of buffer, for ext_free */ + void (*ext_ref) /* add a reference to the ext object */ + (caddr_t, u_int); +}; + +/* + * The core of the mbuf object along with some shortcut defines for + * practical purposes. + */ +struct mbuf { + struct m_hdr m_hdr; + union { + struct { + struct pkthdr MH_pkthdr; /* M_PKTHDR set */ + union { + struct m_ext MH_ext; /* M_EXT set */ + char MH_databuf[MHLEN]; + } MH_dat; + } MH; + char M_databuf[MLEN]; /* !M_PKTHDR, !M_EXT */ + } M_dat; +}; +#define m_next m_hdr.mh_next +#define m_len m_hdr.mh_len +#define m_data m_hdr.mh_data +#define m_type m_hdr.mh_type +#define m_flags m_hdr.mh_flags +#define m_nextpkt m_hdr.mh_nextpkt +#define m_act m_nextpkt +#define m_pkthdr M_dat.MH.MH_pkthdr +#define m_ext M_dat.MH.MH_dat.MH_ext +#define m_pktdat M_dat.MH.MH_dat.MH_databuf +#define m_dat M_dat.M_databuf + +/* + * mbuf flags. + */ +#define M_EXT 0x0001 /* has associated external storage */ +#define M_PKTHDR 0x0002 /* start of record */ +#define M_EOR 0x0004 /* end of record */ +#define M_PROTO1 0x0008 /* protocol-specific */ + +/* + * mbuf pkthdr flags (also stored in m_flags). + */ +#define M_BCAST 0x0100 /* send/received as link-level broadcast */ +#define M_MCAST 0x0200 /* send/received as link-level multicast */ + +/* + * Flags copied when copying m_pkthdr. + */ +#define M_COPYFLAGS (M_PKTHDR|M_EOR|M_PROTO1|M_BCAST|M_MCAST) + +/* + * mbuf types. + */ +#define MT_FREE 0 /* should be on free list */ +#define MT_DATA 1 /* dynamic (data) allocation */ +#define MT_HEADER 2 /* packet header */ +#define MT_SOCKET 3 /* socket structure */ +#define MT_PCB 4 /* protocol control block */ +#define MT_RTABLE 5 /* routing tables */ +#define MT_HTABLE 6 /* IMP host tables */ +#define MT_ATABLE 7 /* address resolution tables */ +#define MT_SONAME 8 /* socket name */ +#define MT_SOOPTS 10 /* socket options */ +#define MT_FTABLE 11 /* fragment reassembly header */ +#define MT_RIGHTS 12 /* access rights */ +#define MT_IFADDR 13 /* interface address */ +#define MT_CONTROL 14 /* extra-data protocol message */ +#define MT_OOBDATA 15 /* expedited data */ + +/* + * General mbuf allocator statistics structure. + */ +struct mbstat { + u_long m_mbufs; /* mbufs obtained from page pool */ + u_long m_clusters; /* clusters obtained from page pool */ + u_long m_spare; /* spare field */ + u_long m_clfree; /* free clusters */ + u_long m_drops; /* times failed to find space */ + u_long m_wait; /* times waited for space */ + u_long m_drain; /* times drained protocols for space */ + u_short m_mtypes[256]; /* type specific mbuf allocations */ +}; + + +/* flags to m_get/MGET */ +#define M_DONTWAIT M_NOWAIT +#define M_WAIT M_WAITOK + +/* Freelists: + * + * Normal mbuf clusters are normally treated as character arrays + * after allocation, but use the first word of the buffer as a free list + * pointer while on the free list. + */ +union mcluster { + union mcluster *mcl_next; + char mcl_buf[MCLBYTES]; +}; + +/* + * mbuf utility macros: + * + * MBUFLOCK(code) + * prevents a section of code from from being interrupted by network + * drivers. + */ +#define MBUFLOCK(code) \ + { int ms = splimp(); \ + { code } \ + splx(ms); \ + } + +/* + * mbuf allocation/deallocation macros: + * + * MGET(struct mbuf *m, int how, int type) + * allocates an mbuf and initializes it to contain internal data. + * + * MGETHDR(struct mbuf *m, int how, int type) + * allocates an mbuf and initializes it to contain a packet header + * and internal data. + */ +#define MGET(m, how, type) { \ + int _ms = splimp(); \ + if (mmbfree == 0) \ + (void)m_mballoc(1, (how)); \ + if (((m) = mmbfree) != 0) { \ + mmbfree = (m)->m_next; \ + mbstat.m_mtypes[MT_FREE]--; \ + (m)->m_type = (type); \ + mbstat.m_mtypes[type]++; \ + (m)->m_next = (struct mbuf *)NULL; \ + (m)->m_nextpkt = (struct mbuf *)NULL; \ + (m)->m_data = (m)->m_dat; \ + (m)->m_flags = 0; \ + splx(_ms); \ + } else { \ + splx(_ms); \ + (m) = m_retry((how), (type)); \ + } \ +} + +#define MGETHDR(m, how, type) { \ + int _ms = splimp(); \ + if (mmbfree == 0) \ + (void)m_mballoc(1, (how)); \ + if (((m) = mmbfree) != 0) { \ + mmbfree = (m)->m_next; \ + mbstat.m_mtypes[MT_FREE]--; \ + (m)->m_type = (type); \ + mbstat.m_mtypes[type]++; \ + (m)->m_next = (struct mbuf *)NULL; \ + (m)->m_nextpkt = (struct mbuf *)NULL; \ + (m)->m_data = (m)->m_pktdat; \ + (m)->m_flags = M_PKTHDR; \ + splx(_ms); \ + } else { \ + splx(_ms); \ + (m) = m_retryhdr((how), (type)); \ + } \ +} + +/* + * Mbuf cluster macros. + * MCLALLOC(caddr_t p, int how) allocates an mbuf cluster. + * MCLGET adds such clusters to a normal mbuf; + * the flag M_EXT is set upon success. + * MCLFREE releases a reference to a cluster allocated by MCLALLOC, + * freeing the cluster if the reference count has reached 0. + */ +#define MCLALLOC(p, how) \ + MBUFLOCK( \ + if (mclfree == 0) \ + (void)m_clalloc(1, (how)); \ + if (((p) = (caddr_t)mclfree) != 0) { \ + ++mclrefcnt[mtocl(p)]; \ + mbstat.m_clfree--; \ + mclfree = ((union mcluster *)(p))->mcl_next; \ + } \ + ) + +#define MCLGET(m, how) \ + { MCLALLOC((m)->m_ext.ext_buf, (how)); \ + if ((m)->m_ext.ext_buf != NULL) { \ + (m)->m_data = (m)->m_ext.ext_buf; \ + (m)->m_flags |= M_EXT; \ + (m)->m_ext.ext_free = NULL; \ + (m)->m_ext.ext_ref = NULL; \ + (m)->m_ext.ext_size = MCLBYTES; \ + } \ + } + +#define MCLFREE(p) \ + MBUFLOCK ( \ + if (--mclrefcnt[mtocl(p)] == 0) { \ + ((union mcluster *)(p))->mcl_next = mclfree; \ + mclfree = (union mcluster *)(p); \ + mbstat.m_clfree++; \ + } \ + ) + +/* + * MFREE(struct mbuf *m, struct mbuf *n) + * Free a single mbuf and associated external storage. + * Place the successor, if any, in n. + */ +#define MFREE(m, n) \ + MBUFLOCK( \ + mbstat.m_mtypes[(m)->m_type]--; \ + if ((m)->m_flags & M_EXT) { \ + if ((m)->m_ext.ext_free) \ + (*((m)->m_ext.ext_free))((m)->m_ext.ext_buf, \ + (m)->m_ext.ext_size); \ + else { \ + char *p = (m)->m_ext.ext_buf; \ + if (--mclrefcnt[mtocl(p)] == 0) { \ + ((union mcluster *)(p))->mcl_next = mclfree; \ + mclfree = (union mcluster *)(p); \ + mbstat.m_clfree++; \ + } \ + } \ + } \ + (n) = (m)->m_next; \ + (m)->m_type = MT_FREE; \ + mbstat.m_mtypes[MT_FREE]++; \ + (m)->m_next = mmbfree; \ + mmbfree = (m); \ + ) + +/* + * Copy mbuf pkthdr from from to to. + * from must have M_PKTHDR set, and to must be empty. + */ +#define M_COPY_PKTHDR(to, from) { \ + (to)->m_pkthdr = (from)->m_pkthdr; \ + (to)->m_flags = (from)->m_flags & M_COPYFLAGS; \ + (to)->m_data = (to)->m_pktdat; \ +} + +/* + * Set the m_data pointer of a newly-allocated mbuf (m_get/MGET) to place + * an object of the specified size at the end of the mbuf, longword aligned. + */ +#define M_ALIGN(m, len) do { \ + (m)->m_data += (MLEN - (len)) & ~(sizeof(long) - 1); \ +} while (0) + +/* + * As above, for mbufs allocated with m_gethdr/MGETHDR + * or initialized by M_COPY_PKTHDR. + */ +#define MH_ALIGN(m, len) do { \ + (m)->m_data += (MHLEN - (len)) & ~(sizeof(long) - 1); \ +} while (0) + +/* + * Compute the amount of space available + * before the current start of data in an mbuf. + */ +#define M_LEADINGSPACE(m) \ + ((m)->m_flags & M_EXT ? /* (m)->m_data - (m)->m_ext.ext_buf */ 0 : \ + (m)->m_flags & M_PKTHDR ? (m)->m_data - (m)->m_pktdat : \ + (m)->m_data - (m)->m_dat) + +/* + * Compute the amount of space available + * after the end of data in an mbuf. + */ +#define M_TRAILINGSPACE(m) \ + ((m)->m_flags & M_EXT ? (m)->m_ext.ext_buf + (m)->m_ext.ext_size - \ + ((m)->m_data + (m)->m_len) : \ + &(m)->m_dat[MLEN] - ((m)->m_data + (m)->m_len)) + +/* + * Arrange to prepend space of size plen to mbuf m. + * If a new mbuf must be allocated, how specifies whether to wait. + * If how is M_DONTWAIT and allocation fails, the original mbuf chain + * is freed and m is set to NULL. + */ +#define M_PREPEND(m, plen, how) { \ + if (M_LEADINGSPACE(m) >= (plen)) { \ + (m)->m_data -= (plen); \ + (m)->m_len += (plen); \ + } else \ + (m) = m_prepend((m), (plen), (how)); \ + if ((m) && (m)->m_flags & M_PKTHDR) \ + (m)->m_pkthdr.len += (plen); \ +} + +/* + * Change mbuf to new type. + * This is a relatively expensive operation and should be avoided. + */ +#define MCHTYPE(m, t) { \ + MBUFLOCK(mbstat.m_mtypes[(m)->m_type]--; mbstat.m_mtypes[t]++;) \ + (m)->m_type = t;\ +} + +/* Length to m_copy to copy all. */ +#define M_COPYALL (uint32_t)1000000000L + +/* Compatibility with 4.3. */ +#define m_copy(m, o, l) m_copym((m), (o), (l), M_DONTWAIT) + +#ifdef _KERNEL +extern struct mbuf *mbutl; /* virtual address of mclusters */ +extern char *mclrefcnt; /* cluster reference counts */ +extern struct mbstat mbstat; +extern uint32_t nmbclusters; +extern uint32_t nmbufs; +extern struct mbuf *mmbfree; +extern union mcluster *mclfree; +extern int max_linkhdr; /* largest link-level header */ +extern int max_protohdr; /* largest protocol header */ +extern int max_hdr; /* largest link+protocol header */ +extern int max_datalen; /* MHLEN - max_hdr */ + +struct mbuf *m_copym(struct mbuf *, int, uint32_t, int); +struct mbuf *m_copypacket(struct mbuf *, int); +struct mbuf *m_devget(char *, int, int, struct ifnet *, + void (*copy)(char *, caddr_t, u_int)); +struct mbuf *m_free(struct mbuf *); +struct mbuf *m_get(int, int); +struct mbuf *m_getclr(int, int); +struct mbuf *m_gethdr(int, int); +struct mbuf *m_prepend(struct mbuf *,int,int); +struct mbuf *m_pullup(struct mbuf *, int); +struct mbuf *m_retry(int, int); +struct mbuf *m_retryhdr(int, int); +struct mbuf *m_split(struct mbuf *,int,int); +void m_adj(struct mbuf *, int); +void m_cat(struct mbuf *,struct mbuf *); +int m_mballoc(int, int); +int m_clalloc(int, int); +int m_copyback(struct mbuf *, int, int, caddr_t); +int m_copydata(const struct mbuf *, int, int, caddr_t); +void m_freem(struct mbuf *); +void m_reclaim(void); + +#endif /* _KERNEL */ + +#endif /* !_SYS_MBUF_H_ */ |