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[/] [openrisc/] [trunk/] [rtos/] [rtems/] [c/] [src/] [libnetworking/] [kern/] [uipc_mbuf.c] - Rev 173
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/* * 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: uipc_mbuf.c,v 1.2 2001-09-27 12:01:51 chris Exp $ */ #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 *)) __attribute__ ((unused)); 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; /* "number of clusters of pages" */ #define NCL_INIT 1 #define NMB_INIT 16 /* * 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); } void m_reclaim(void) { 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; }