diff options
Diffstat (limited to 'cpukit/libnetworking/kern/uipc_mbuf.c')
| -rw-r--r-- | cpukit/libnetworking/kern/uipc_mbuf.c | 851 |
1 files changed, 851 insertions, 0 deletions
diff --git a/cpukit/libnetworking/kern/uipc_mbuf.c b/cpukit/libnetworking/kern/uipc_mbuf.c new file mode 100644 index 0000000000..f682be94a7 --- /dev/null +++ b/cpukit/libnetworking/kern/uipc_mbuf.c @@ -0,0 +1,851 @@ +/* + * Copyright (c) 1982, 1986, 1988, 1991, 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. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by the University of + * California, Berkeley and its contributors. + * 4. 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. + * + * @(#)uipc_mbuf.c 8.2 (Berkeley) 1/4/94 + * $Id$ + */ + +#include <sys/param.h> +#include <sys/systm.h> +#include <sys/proc.h> +#include <sys/malloc.h> +#define MBTYPES +#include <sys/mbuf.h> +#include <sys/kernel.h> +#include <sys/syslog.h> +#include <sys/domain.h> +#include <sys/protosw.h> + +#include <vm/vm.h> +#include <vm/vm_param.h> +#include <vm/vm_kern.h> +#include <vm/vm_extern.h> + +static void mbinit __P((void *)); +SYSINIT(mbuf, SI_SUB_MBUF, SI_ORDER_FIRST, mbinit, NULL) + +struct mbuf *mbutl; +char *mclrefcnt; +struct mbstat mbstat; +struct mbuf *mmbfree; +union mcluster *mclfree; +int max_linkhdr; +int max_protohdr; +int max_hdr; +int max_datalen; + +static void m_reclaim __P((void)); + +/* "number of clusters of pages" */ +#define NCL_INIT 1 + +#define NMB_INIT 16 + +/* ARGSUSED*/ +static void +mbinit(dummy) + void *dummy; +{ + int s; + + mmbfree = NULL; mclfree = NULL; + s = splimp(); + if (m_mballoc(NMB_INIT, M_DONTWAIT) == 0) + goto bad; + if (m_clalloc(NCL_INIT, M_DONTWAIT) == 0) + goto bad; + splx(s); + return; +bad: + panic("mbinit"); +} + +/* + * Allocate at least nmb mbufs and place on mbuf free list. + * Must be called at splimp. + */ +/* ARGSUSED */ +int +m_mballoc(nmb, nowait) + register int nmb; + int nowait; +{ + register caddr_t p; + register int i; + int nbytes; + + /* Once we run out of map space, it will be impossible to get + * any more (nothing is ever freed back to the map) (XXX which + * is dumb). (however you are not dead as m_reclaim might + * still be able to free a substantial amount of space). + */ + if (mb_map_full) + return (0); + + nbytes = round_page(nmb * MSIZE); + p = (caddr_t)kmem_malloc(mb_map, nbytes, nowait ? M_NOWAIT : M_WAITOK); + /* + * Either the map is now full, or this is nowait and there + * are no pages left. + */ + if (p == NULL) + return (0); + + nmb = nbytes / MSIZE; + for (i = 0; i < nmb; i++) { + ((struct mbuf *)p)->m_next = mmbfree; + mmbfree = (struct mbuf *)p; + p += MSIZE; + } + mbstat.m_mbufs += nmb; + return (1); +} + +/* + * Allocate some number of mbuf clusters + * and place on cluster free list. + * Must be called at splimp. + */ +/* ARGSUSED */ +int +m_clalloc(ncl, nowait) + register int ncl; + int nowait; +{ + register caddr_t p; + register int i; + + /* + * Once we run out of map space, it will be impossible + * to get any more (nothing is ever freed back to the + * map). + */ + if (mb_map_full) + return (0); + + p = (caddr_t)kmem_malloc(mb_map, ncl*MCLBYTES, + nowait ? M_NOWAIT : M_WAITOK); + /* + * Either the map is now full, or this is nowait and there + * are no pages left. + */ + if (p == NULL) + return (0); + + for (i = 0; i < ncl; i++) { + ((union mcluster *)p)->mcl_next = mclfree; + mclfree = (union mcluster *)p; + p += MCLBYTES; + mbstat.m_clfree++; + } + mbstat.m_clusters += ncl; + return (1); +} + +/* + * When MGET failes, ask protocols to free space when short of memory, + * then re-attempt to allocate an mbuf. + */ +struct mbuf * +m_retry(i, t) + int i, t; +{ + register struct mbuf *m; + + m_reclaim(); +#define m_retry(i, t) (struct mbuf *)0 + MGET(m, i, t); +#undef m_retry + if (m != NULL) + mbstat.m_wait++; + else + mbstat.m_drops++; + return (m); +} + +/* + * As above; retry an MGETHDR. + */ +struct mbuf * +m_retryhdr(i, t) + int i, t; +{ + register struct mbuf *m; + + m_reclaim(); +#define m_retryhdr(i, t) (struct mbuf *)0 + MGETHDR(m, i, t); +#undef m_retryhdr + if (m != NULL) + mbstat.m_wait++; + else + mbstat.m_drops++; + return (m); +} + +static void +m_reclaim() +{ + register struct domain *dp; + register struct protosw *pr; + int s = splimp(); + + for (dp = domains; dp; dp = dp->dom_next) + for (pr = dp->dom_protosw; pr < dp->dom_protoswNPROTOSW; pr++) + if (pr->pr_drain) + (*pr->pr_drain)(); + splx(s); + mbstat.m_drain++; +} + +/* + * Space allocation routines. + * These are also available as macros + * for critical paths. + */ +struct mbuf * +m_get(nowait, type) + int nowait, type; +{ + register struct mbuf *m; + + MGET(m, nowait, type); + return (m); +} + +struct mbuf * +m_gethdr(nowait, type) + int nowait, type; +{ + register struct mbuf *m; + + MGETHDR(m, nowait, type); + return (m); +} + +struct mbuf * +m_getclr(nowait, type) + int nowait, type; +{ + register struct mbuf *m; + + MGET(m, nowait, type); + if (m == 0) + return (0); + bzero(mtod(m, caddr_t), MLEN); + return (m); +} + +struct mbuf * +m_free(m) + struct mbuf *m; +{ + register struct mbuf *n; + + MFREE(m, n); + return (n); +} + +void +m_freem(m) + register struct mbuf *m; +{ + register struct mbuf *n; + + if (m == NULL) + return; + do { + MFREE(m, n); + m = n; + } while (m); +} + +/* + * Mbuffer utility routines. + */ + +/* + * Lesser-used path for M_PREPEND: + * allocate new mbuf to prepend to chain, + * copy junk along. + */ +struct mbuf * +m_prepend(m, len, how) + register struct mbuf *m; + int len, how; +{ + struct mbuf *mn; + + MGET(mn, how, m->m_type); + if (mn == (struct mbuf *)NULL) { + m_freem(m); + return ((struct mbuf *)NULL); + } + if (m->m_flags & M_PKTHDR) { + M_COPY_PKTHDR(mn, m); + m->m_flags &= ~M_PKTHDR; + } + mn->m_next = m; + m = mn; + if (len < MHLEN) + MH_ALIGN(m, len); + m->m_len = len; + return (m); +} + +/* + * Make a copy of an mbuf chain starting "off0" bytes from the beginning, + * continuing for "len" bytes. If len is M_COPYALL, copy to end of mbuf. + * The wait parameter is a choice of M_WAIT/M_DONTWAIT from caller. + */ +static int MCFail; + +struct mbuf * +m_copym(m, off0, len, wait) + register struct mbuf *m; + int off0, wait; + register int len; +{ + register struct mbuf *n, **np; + register int off = off0; + struct mbuf *top; + int copyhdr = 0; + + if (off < 0 || len < 0) + panic("m_copym"); + if (off == 0 && m->m_flags & M_PKTHDR) + copyhdr = 1; + while (off > 0) { + if (m == 0) + panic("m_copym"); + if (off < m->m_len) + break; + off -= m->m_len; + m = m->m_next; + } + np = ⊤ + top = 0; + while (len > 0) { + if (m == 0) { + if (len != M_COPYALL) + panic("m_copym"); + break; + } + MGET(n, wait, m->m_type); + *np = n; + if (n == 0) + goto nospace; + if (copyhdr) { + M_COPY_PKTHDR(n, m); + if (len == M_COPYALL) + n->m_pkthdr.len -= off0; + else + n->m_pkthdr.len = len; + copyhdr = 0; + } + n->m_len = min(len, m->m_len - off); + if (m->m_flags & M_EXT) { + n->m_data = m->m_data + off; + if(!m->m_ext.ext_ref) + mclrefcnt[mtocl(m->m_ext.ext_buf)]++; + else + (*(m->m_ext.ext_ref))(m->m_ext.ext_buf, + m->m_ext.ext_size); + n->m_ext = m->m_ext; + n->m_flags |= M_EXT; + } else + bcopy(mtod(m, caddr_t)+off, mtod(n, caddr_t), + (unsigned)n->m_len); + if (len != M_COPYALL) + len -= n->m_len; + off = 0; + m = m->m_next; + np = &n->m_next; + } + if (top == 0) + MCFail++; + return (top); +nospace: + m_freem(top); + MCFail++; + return (0); +} + +/* + * Copy an entire packet, including header (which must be present). + * An optimization of the common case `m_copym(m, 0, M_COPYALL, how)'. + */ +struct mbuf * +m_copypacket(m, how) + struct mbuf *m; + int how; +{ + struct mbuf *top, *n, *o; + + MGET(n, how, m->m_type); + top = n; + if (!n) + goto nospace; + + M_COPY_PKTHDR(n, m); + n->m_len = m->m_len; + if (m->m_flags & M_EXT) { + n->m_data = m->m_data; + mclrefcnt[mtocl(m->m_ext.ext_buf)]++; + n->m_ext = m->m_ext; + n->m_flags |= M_EXT; + } else { + bcopy(mtod(m, char *), mtod(n, char *), n->m_len); + } + + m = m->m_next; + while (m) { + MGET(o, how, m->m_type); + if (!o) + goto nospace; + + n->m_next = o; + n = n->m_next; + + n->m_len = m->m_len; + if (m->m_flags & M_EXT) { + n->m_data = m->m_data; + mclrefcnt[mtocl(m->m_ext.ext_buf)]++; + n->m_ext = m->m_ext; + n->m_flags |= M_EXT; + } else { + bcopy(mtod(m, char *), mtod(n, char *), n->m_len); + } + + m = m->m_next; + } + return top; +nospace: + m_freem(top); + MCFail++; + return 0; +} + +/* + * Copy data from an mbuf chain starting "off" bytes from the beginning, + * continuing for "len" bytes, into the indicated buffer. + */ +void +m_copydata(m, off, len, cp) + register struct mbuf *m; + register int off; + register int len; + caddr_t cp; +{ + register unsigned count; + + if (off < 0 || len < 0) + panic("m_copydata"); + while (off > 0) { + if (m == 0) + panic("m_copydata"); + if (off < m->m_len) + break; + off -= m->m_len; + m = m->m_next; + } + while (len > 0) { + if (m == 0) + panic("m_copydata"); + count = min(m->m_len - off, len); + bcopy(mtod(m, caddr_t) + off, cp, count); + len -= count; + cp += count; + off = 0; + m = m->m_next; + } +} + +/* + * Concatenate mbuf chain n to m. + * Both chains must be of the same type (e.g. MT_DATA). + * Any m_pkthdr is not updated. + */ +void +m_cat(m, n) + register struct mbuf *m, *n; +{ + while (m->m_next) + m = m->m_next; + while (n) { + if (m->m_flags & M_EXT || + m->m_data + m->m_len + n->m_len >= &m->m_dat[MLEN]) { + /* just join the two chains */ + m->m_next = n; + return; + } + /* splat the data from one into the other */ + bcopy(mtod(n, caddr_t), mtod(m, caddr_t) + m->m_len, + (u_int)n->m_len); + m->m_len += n->m_len; + n = m_free(n); + } +} + +void +m_adj(mp, req_len) + struct mbuf *mp; + int req_len; +{ + register int len = req_len; + register struct mbuf *m; + register int count; + + if ((m = mp) == NULL) + return; + if (len >= 0) { + /* + * Trim from head. + */ + while (m != NULL && len > 0) { + if (m->m_len <= len) { + len -= m->m_len; + m->m_len = 0; + m = m->m_next; + } else { + m->m_len -= len; + m->m_data += len; + len = 0; + } + } + m = mp; + if (mp->m_flags & M_PKTHDR) + m->m_pkthdr.len -= (req_len - len); + } else { + /* + * Trim from tail. Scan the mbuf chain, + * calculating its length and finding the last mbuf. + * If the adjustment only affects this mbuf, then just + * adjust and return. Otherwise, rescan and truncate + * after the remaining size. + */ + len = -len; + count = 0; + for (;;) { + count += m->m_len; + if (m->m_next == (struct mbuf *)0) + break; + m = m->m_next; + } + if (m->m_len >= len) { + m->m_len -= len; + if (mp->m_flags & M_PKTHDR) + mp->m_pkthdr.len -= len; + return; + } + count -= len; + if (count < 0) + count = 0; + /* + * Correct length for chain is "count". + * Find the mbuf with last data, adjust its length, + * and toss data from remaining mbufs on chain. + */ + m = mp; + if (m->m_flags & M_PKTHDR) + m->m_pkthdr.len = count; + for (; m; m = m->m_next) { + if (m->m_len >= count) { + m->m_len = count; + break; + } + count -= m->m_len; + } + while (m->m_next) + (m = m->m_next) ->m_len = 0; + } +} + +/* + * Rearange an mbuf chain so that len bytes are contiguous + * and in the data area of an mbuf (so that mtod and dtom + * will work for a structure of size len). Returns the resulting + * mbuf chain on success, frees it and returns null on failure. + * If there is room, it will add up to max_protohdr-len extra bytes to the + * contiguous region in an attempt to avoid being called next time. + */ +static int MPFail; + +struct mbuf * +m_pullup(n, len) + register struct mbuf *n; + int len; +{ + register struct mbuf *m; + register int count; + int space; + + /* + * If first mbuf has no cluster, and has room for len bytes + * without shifting current data, pullup into it, + * otherwise allocate a new mbuf to prepend to the chain. + */ + if ((n->m_flags & M_EXT) == 0 && + n->m_data + len < &n->m_dat[MLEN] && n->m_next) { + if (n->m_len >= len) + return (n); + m = n; + n = n->m_next; + len -= m->m_len; + } else { + if (len > MHLEN) + goto bad; + MGET(m, M_DONTWAIT, n->m_type); + if (m == 0) + goto bad; + m->m_len = 0; + if (n->m_flags & M_PKTHDR) { + M_COPY_PKTHDR(m, n); + n->m_flags &= ~M_PKTHDR; + } + } + space = &m->m_dat[MLEN] - (m->m_data + m->m_len); + do { + count = min(min(max(len, max_protohdr), space), n->m_len); + bcopy(mtod(n, caddr_t), mtod(m, caddr_t) + m->m_len, + (unsigned)count); + len -= count; + m->m_len += count; + n->m_len -= count; + space -= count; + if (n->m_len) + n->m_data += count; + else + n = m_free(n); + } while (len > 0 && n); + if (len > 0) { + (void) m_free(m); + goto bad; + } + m->m_next = n; + return (m); +bad: + m_freem(n); + MPFail++; + return (0); +} + +/* + * Partition an mbuf chain in two pieces, returning the tail -- + * all but the first len0 bytes. In case of failure, it returns NULL and + * attempts to restore the chain to its original state. + */ +struct mbuf * +m_split(m0, len0, wait) + register struct mbuf *m0; + int len0, wait; +{ + register struct mbuf *m, *n; + unsigned len = len0, remain; + + for (m = m0; m && len > m->m_len; m = m->m_next) + len -= m->m_len; + if (m == 0) + return (0); + remain = m->m_len - len; + if (m0->m_flags & M_PKTHDR) { + MGETHDR(n, wait, m0->m_type); + if (n == 0) + return (0); + n->m_pkthdr.rcvif = m0->m_pkthdr.rcvif; + n->m_pkthdr.len = m0->m_pkthdr.len - len0; + m0->m_pkthdr.len = len0; + if (m->m_flags & M_EXT) + goto extpacket; + if (remain > MHLEN) { + /* m can't be the lead packet */ + MH_ALIGN(n, 0); + n->m_next = m_split(m, len, wait); + if (n->m_next == 0) { + (void) m_free(n); + return (0); + } else + return (n); + } else + MH_ALIGN(n, remain); + } else if (remain == 0) { + n = m->m_next; + m->m_next = 0; + return (n); + } else { + MGET(n, wait, m->m_type); + if (n == 0) + return (0); + M_ALIGN(n, remain); + } +extpacket: + if (m->m_flags & M_EXT) { + n->m_flags |= M_EXT; + n->m_ext = m->m_ext; + if(!m->m_ext.ext_ref) + mclrefcnt[mtocl(m->m_ext.ext_buf)]++; + else + (*(m->m_ext.ext_ref))(m->m_ext.ext_buf, + m->m_ext.ext_size); + m->m_ext.ext_size = 0; /* For Accounting XXXXXX danger */ + n->m_data = m->m_data + len; + } else { + bcopy(mtod(m, caddr_t) + len, mtod(n, caddr_t), remain); + } + n->m_len = remain; + m->m_len = len; + n->m_next = m->m_next; + m->m_next = 0; + return (n); +} +/* + * Routine to copy from device local memory into mbufs. + */ +struct mbuf * +m_devget(buf, totlen, off0, ifp, copy) + char *buf; + int totlen, off0; + struct ifnet *ifp; + void (*copy) __P((char *from, caddr_t to, u_int len)); +{ + register struct mbuf *m; + struct mbuf *top = 0, **mp = ⊤ + register int off = off0, len; + register char *cp; + char *epkt; + + cp = buf; + epkt = cp + totlen; + if (off) { + cp += off + 2 * sizeof(u_short); + totlen -= 2 * sizeof(u_short); + } + MGETHDR(m, M_DONTWAIT, MT_DATA); + if (m == 0) + return (0); + m->m_pkthdr.rcvif = ifp; + m->m_pkthdr.len = totlen; + m->m_len = MHLEN; + + while (totlen > 0) { + if (top) { + MGET(m, M_DONTWAIT, MT_DATA); + if (m == 0) { + m_freem(top); + return (0); + } + m->m_len = MLEN; + } + len = min(totlen, epkt - cp); + if (len >= MINCLSIZE) { + MCLGET(m, M_DONTWAIT); + if (m->m_flags & M_EXT) + m->m_len = len = min(len, MCLBYTES); + else + len = m->m_len; + } else { + /* + * Place initial small packet/header at end of mbuf. + */ + if (len < m->m_len) { + if (top == 0 && len + max_linkhdr <= m->m_len) + m->m_data += max_linkhdr; + m->m_len = len; + } else + len = m->m_len; + } + if (copy) + copy(cp, mtod(m, caddr_t), (unsigned)len); + else + bcopy(cp, mtod(m, caddr_t), (unsigned)len); + cp += len; + *mp = m; + mp = &m->m_next; + totlen -= len; + if (cp == epkt) + cp = buf; + } + return (top); +} + +/* + * Copy data from a buffer back into the indicated mbuf chain, + * starting "off" bytes from the beginning, extending the mbuf + * chain if necessary. + */ +void +m_copyback(m0, off, len, cp) + struct mbuf *m0; + register int off; + register int len; + caddr_t cp; +{ + register int mlen; + register struct mbuf *m = m0, *n; + int totlen = 0; + + if (m0 == 0) + return; + while (off > (mlen = m->m_len)) { + off -= mlen; + totlen += mlen; + if (m->m_next == 0) { + n = m_getclr(M_DONTWAIT, m->m_type); + if (n == 0) + goto out; + n->m_len = min(MLEN, len + off); + m->m_next = n; + } + m = m->m_next; + } + while (len > 0) { + mlen = min (m->m_len - off, len); + bcopy(cp, off + mtod(m, caddr_t), (unsigned)mlen); + cp += mlen; + len -= mlen; + mlen += off; + off = 0; + totlen += mlen; + if (len == 0) + break; + if (m->m_next == 0) { + n = m_get(M_DONTWAIT, m->m_type); + if (n == 0) + break; + n->m_len = min(MLEN, len); + m->m_next = n; + } + m = m->m_next; + } +out: if (((m = m0)->m_flags & M_PKTHDR) && (m->m_pkthdr.len < totlen)) + m->m_pkthdr.len = totlen; +} |