/* $OpenBSD: uipc_mbuf.c,v 1.137 2010/06/07 19:47:25 blambert Exp $ */ /* $NetBSD: uipc_mbuf.c,v 1.15.4.1 1996/06/13 17:11:44 cgd Exp $ */ /* * 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. 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 */ /* * @(#)COPYRIGHT 1.1 (NRL) 17 January 1995 * * NRL grants permission for redistribution and use in source and binary * forms, with or without modification, of the software and documentation * created at NRL 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 acknowledgements: * This product includes software developed by the University of * California, Berkeley and its contributors. * This product includes software developed at the Information * Technology Division, US Naval Research Laboratory. * 4. Neither the name of the NRL nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THE SOFTWARE PROVIDED BY NRL IS PROVIDED BY NRL 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 NRL 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. * * The views and conclusions contained in the software and documentation * are those of the authors and should not be interpreted as representing * official policies, either expressed or implied, of the US Naval * Research Laboratory (NRL). */ #include #include #include #include #define MBTYPES #include #include #include #include #include #include #include #include #include #include #include struct mbstat mbstat; /* mbuf stats */ struct pool mbpool; /* mbuf pool */ /* mbuf cluster pools */ u_int mclsizes[] = { MCLBYTES, /* must be at slot 0 */ 4 * 1024, 8 * 1024, 9 * 1024, 12 * 1024, 16 * 1024, 64 * 1024 }; static char mclnames[MCLPOOLS][8]; struct pool mclpools[MCLPOOLS]; int m_clpool(u_int); int max_linkhdr; /* largest link-level header */ int max_protohdr; /* largest protocol header */ int max_hdr; /* largest link+protocol header */ int max_datalen; /* MHLEN - max_hdr */ struct timeout m_cltick_tmo; int m_clticks; void m_cltick(void *); void m_extfree(struct mbuf *); struct mbuf *m_copym0(struct mbuf *, int, int, int, int); void nmbclust_update(void); const char *mclpool_warnmsg = "WARNING: mclpools limit reached; increase kern.maxclusters"; /* * Initialize the mbuf allocator. */ void mbinit(void) { int i; pool_init(&mbpool, MSIZE, 0, 0, 0, "mbpl", NULL); pool_setlowat(&mbpool, mblowat); for (i = 0; i < nitems(mclsizes); i++) { snprintf(mclnames[i], sizeof(mclnames[0]), "mcl%dk", mclsizes[i] >> 10); pool_init(&mclpools[i], mclsizes[i], 0, 0, 0, mclnames[i], NULL); pool_setlowat(&mclpools[i], mcllowat); } nmbclust_update(); timeout_set(&m_cltick_tmo, m_cltick, NULL); m_cltick(NULL); } void nmbclust_update(void) { int i; /* * Set the hard limit on the mclpools to the number of * mbuf clusters the kernel is to support. Log the limit * reached message max once a minute. */ for (i = 0; i < nitems(mclsizes); i++) { (void)pool_sethardlimit(&mclpools[i], nmbclust, mclpool_warnmsg, 60); } pool_sethiwat(&mbpool, nmbclust); } void m_reclaim(void *arg, int flags) { struct domain *dp; struct protosw *pr; int s = splnet(); 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)(); mbstat.m_drain++; splx(s); } /* * Space allocation routines. */ struct mbuf * m_get(int nowait, int type) { struct mbuf *m; int s; s = splnet(); m = pool_get(&mbpool, nowait == M_WAIT ? PR_WAITOK : 0); if (m) mbstat.m_mtypes[type]++; splx(s); if (m) { m->m_type = type; m->m_next = (struct mbuf *)NULL; m->m_nextpkt = (struct mbuf *)NULL; m->m_data = m->m_dat; m->m_flags = 0; } return (m); } /* * ATTN: When changing anything here check m_inithdr() and m_defrag() those * may need to change as well. */ struct mbuf * m_gethdr(int nowait, int type) { struct mbuf *m; int s; s = splnet(); m = pool_get(&mbpool, nowait == M_WAIT ? PR_WAITOK : 0); if (m) mbstat.m_mtypes[type]++; splx(s); if (m) { m->m_type = type; /* keep in sync with m_inithdr */ m->m_next = (struct mbuf *)NULL; m->m_nextpkt = (struct mbuf *)NULL; m->m_data = m->m_pktdat; m->m_flags = M_PKTHDR; bzero(&m->m_pkthdr, sizeof(m->m_pkthdr)); } return (m); } struct mbuf * m_inithdr(struct mbuf *m) { /* keep in sync with m_gethdr */ m->m_next = (struct mbuf *)NULL; m->m_nextpkt = (struct mbuf *)NULL; m->m_data = m->m_pktdat; m->m_flags = M_PKTHDR; bzero(&m->m_pkthdr, sizeof(m->m_pkthdr)); return (m); } struct mbuf * m_getclr(int nowait, int type) { struct mbuf *m; MGET(m, nowait, type); if (m == NULL) return (NULL); memset(mtod(m, caddr_t), 0, MLEN); return (m); } int m_clpool(u_int pktlen) { int pi; for (pi = 0; pi < MCLPOOLS; pi++) { if (pktlen <= mclsizes[pi]) return (pi); } return (-1); } void m_clinitifp(struct ifnet *ifp) { struct mclpool *mclp = ifp->if_data.ifi_mclpool; int i; /* Initialize high water marks for use of cluster pools */ for (i = 0; i < MCLPOOLS; i++) { mclp = &ifp->if_data.ifi_mclpool[i]; if (mclp->mcl_lwm == 0) mclp->mcl_lwm = 2; if (mclp->mcl_hwm == 0) mclp->mcl_hwm = 32768; mclp->mcl_cwm = MAX(4, mclp->mcl_lwm); } } void m_clsetwms(struct ifnet *ifp, u_int pktlen, u_int lwm, u_int hwm) { int pi; pi = m_clpool(pktlen); if (pi == -1) return; ifp->if_data.ifi_mclpool[pi].mcl_lwm = lwm; ifp->if_data.ifi_mclpool[pi].mcl_hwm = hwm; } /* * Record when the last timeout has been run. If the delta is * too high, m_cldrop() will notice and decrease the interface * high water marks. */ void m_cltick(void *arg) { extern int ticks; m_clticks = ticks; timeout_add(&m_cltick_tmo, 1); } int m_livelock; int m_cldrop(struct ifnet *ifp, int pi) { static int liveticks; struct mclpool *mclp; extern int ticks; int i; if (m_livelock == 0 && ticks - m_clticks > 2) { struct ifnet *aifp; /* * Timeout did not run, so we are in some kind of livelock. * Decrease the cluster allocation high water marks on all * interfaces and prevent them from growth for the very near * future. */ m_livelock = 1; ifp->if_data.ifi_livelocks++; liveticks = ticks; TAILQ_FOREACH(aifp, &ifnet, if_list) { mclp = aifp->if_data.ifi_mclpool; for (i = 0; i < MCLPOOLS; i++) { mclp[i].mcl_cwm = max(mclp[i].mcl_cwm / 2, mclp[i].mcl_lwm); } } } else if (m_livelock && ticks - liveticks > 5) m_livelock = 0; /* Let the high water marks grow again */ mclp = &ifp->if_data.ifi_mclpool[pi]; if (m_livelock == 0 && ISSET(ifp->if_flags, IFF_RUNNING) && mclp->mcl_alive <= 2 && mclp->mcl_cwm < mclp->mcl_hwm) { /* About to run out, so increase the current watermark */ mclp->mcl_cwm++; } else if (mclp->mcl_alive >= mclp->mcl_cwm) return (1); /* No more packets given */ return (0); } void m_clcount(struct ifnet *ifp, int pi) { ifp->if_data.ifi_mclpool[pi].mcl_alive++; } void m_cluncount(struct mbuf *m, int all) { struct mbuf_ext *me; do { me = &m->m_ext; if (((m->m_flags & (M_EXT|M_CLUSTER)) != (M_EXT|M_CLUSTER)) || (me->ext_ifp == NULL)) continue; me->ext_ifp->if_data.ifi_mclpool[me->ext_backend].mcl_alive--; me->ext_ifp = NULL; } while (all && (m = m->m_next)); } struct mbuf * m_clget(struct mbuf *m, int how, struct ifnet *ifp, u_int pktlen) { struct mbuf *m0 = NULL; int pi; int s; pi = m_clpool(pktlen); #ifdef DIAGNOSTIC if (pi == -1) panic("m_clget: request for %u byte cluster", pktlen); #endif if (ifp != NULL && m_cldrop(ifp, pi)) return (NULL); s = splnet(); if (m == NULL) { MGETHDR(m0, M_DONTWAIT, MT_DATA); if (m0 == NULL) { splx(s); return (NULL); } m = m0; } m->m_ext.ext_buf = pool_get(&mclpools[pi], how == M_WAIT ? PR_WAITOK : 0); if (!m->m_ext.ext_buf) { if (m0) m_freem(m0); splx(s); return (NULL); } if (ifp != NULL) m_clcount(ifp, pi); splx(s); m->m_data = m->m_ext.ext_buf; m->m_flags |= M_EXT|M_CLUSTER; m->m_ext.ext_size = mclpools[pi].pr_size; m->m_ext.ext_free = NULL; m->m_ext.ext_arg = NULL; m->m_ext.ext_backend = pi; m->m_ext.ext_ifp = ifp; MCLINITREFERENCE(m); return (m); } struct mbuf * m_free_unlocked(struct mbuf *m) { struct mbuf *n; mbstat.m_mtypes[m->m_type]--; if (m->m_flags & M_PKTHDR) m_tag_delete_chain(m); if (m->m_flags & M_EXT) m_extfree(m); n = m->m_next; pool_put(&mbpool, m); return (n); } struct mbuf * m_free(struct mbuf *m) { struct mbuf *n; int s; s = splnet(); n = m_free_unlocked(m); splx(s); return (n); } void m_extfree(struct mbuf *m) { if (MCLISREFERENCED(m)) { m->m_ext.ext_nextref->m_ext.ext_prevref = m->m_ext.ext_prevref; m->m_ext.ext_prevref->m_ext.ext_nextref = m->m_ext.ext_nextref; } else if (m->m_flags & M_CLUSTER) { m_cluncount(m, 0); pool_put(&mclpools[m->m_ext.ext_backend], m->m_ext.ext_buf); } else if (m->m_ext.ext_free) (*(m->m_ext.ext_free))(m->m_ext.ext_buf, m->m_ext.ext_size, m->m_ext.ext_arg); else panic("unknown type of extension buffer"); m->m_ext.ext_size = 0; m->m_flags &= ~(M_EXT|M_CLUSTER); } void m_freem(struct mbuf *m) { struct mbuf *n; int s; if (m == NULL) return; s = splnet(); do { n = m_free_unlocked(m); } while ((m = n) != NULL); splx(s); } /* * mbuf chain defragmenter. This function uses some evil tricks to defragment * an mbuf chain into a single buffer without changing the mbuf pointer. * This needs to know a lot of the mbuf internals to make this work. */ int m_defrag(struct mbuf *m, int how) { struct mbuf *m0; if (m->m_next == NULL) return 0; #ifdef DIAGNOSTIC if (!(m->m_flags & M_PKTHDR)) panic("m_defrag: no packet hdr or not a chain"); #endif if ((m0 = m_gethdr(how, m->m_type)) == NULL) return -1; if (m->m_pkthdr.len > MHLEN) { MCLGETI(m0, how, NULL, m->m_pkthdr.len); if (!(m0->m_flags & M_EXT)) { m_free(m0); return -1; } } m_copydata(m, 0, m->m_pkthdr.len, mtod(m0, caddr_t)); m0->m_pkthdr.len = m0->m_len = m->m_pkthdr.len; /* free chain behind and possible ext buf on the first mbuf */ m_freem(m->m_next); m->m_next = NULL; if (m->m_flags & M_EXT) { int s = splnet(); m_extfree(m); splx(s); } /* * Bounce copy mbuf over to the original mbuf and set everything up. * This needs to reset or clear all pointers that may go into the * original mbuf chain. */ if (m0->m_flags & M_EXT) { bcopy(&m0->m_ext, &m->m_ext, sizeof(struct mbuf_ext)); MCLINITREFERENCE(m); m->m_flags |= M_EXT|M_CLUSTER; m->m_data = m->m_ext.ext_buf; } else { m->m_data = m->m_pktdat; bcopy(m0->m_data, m->m_data, m0->m_len); } m->m_pkthdr.len = m->m_len = m0->m_len; m->m_pkthdr.pf.hdr = NULL; /* altq will cope */ m0->m_flags &= ~(M_EXT|M_CLUSTER); /* cluster is gone */ m_free(m0); return 0; } /* * Mbuffer utility routines. */ /* * Ensure len bytes of contiguous space at the beginning of the mbuf chain */ struct mbuf * m_prepend(struct mbuf *m, int len, int how) { struct mbuf *mn; if (len > MHLEN) panic("mbuf prepend length too big"); if (M_LEADINGSPACE(m) >= len) { m->m_data -= len; m->m_len += len; } else { MGET(mn, how, m->m_type); if (mn == NULL) { m_freem(m); return (NULL); } if (m->m_flags & M_PKTHDR) M_MOVE_PKTHDR(mn, m); mn->m_next = m; m = mn; MH_ALIGN(m, len); m->m_len = len; } if (m->m_flags & M_PKTHDR) m->m_pkthdr.len += len; return (m); } /* * Make a copy of an mbuf chain starting "off" 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. */ struct mbuf * m_copym(struct mbuf *m, int off, int len, int wait) { return m_copym0(m, off, len, wait, 0); /* shallow copy on M_EXT */ } /* * m_copym2() is like m_copym(), except it COPIES cluster mbufs, instead * of merely bumping the reference count. */ struct mbuf * m_copym2(struct mbuf *m, int off, int len, int wait) { return m_copym0(m, off, len, wait, 1); /* deep copy */ } struct mbuf * m_copym0(struct mbuf *m, int off, int len, int wait, int deep) { struct mbuf *n, **np; struct mbuf *top; int copyhdr = 0; if (off < 0 || len < 0) panic("m_copym0: off %d, len %d", off, len); if (off == 0 && m->m_flags & M_PKTHDR) copyhdr = 1; if ((m = m_getptr(m, off, &off)) == NULL) panic("m_copym0: short mbuf chain"); np = ⊤ top = NULL; while (len > 0) { if (m == NULL) { if (len != M_COPYALL) panic("m_copym0: m == NULL and not COPYALL"); break; } MGET(n, wait, m->m_type); *np = n; if (n == NULL) goto nospace; if (copyhdr) { if (m_dup_pkthdr(n, m)) goto nospace; if (len != M_COPYALL) n->m_pkthdr.len = len; copyhdr = 0; } n->m_len = min(len, m->m_len - off); if (m->m_flags & M_EXT) { if (!deep) { n->m_data = m->m_data + off; n->m_ext = m->m_ext; MCLADDREFERENCE(m, n); } else { /* * we are unsure about the way m was allocated. * copy into multiple MCLBYTES cluster mbufs. */ MCLGET(n, wait); n->m_len = 0; n->m_len = M_TRAILINGSPACE(n); n->m_len = min(n->m_len, len); n->m_len = min(n->m_len, m->m_len - off); memcpy(mtod(n, caddr_t), mtod(m, caddr_t) + off, (unsigned)n->m_len); } } else memcpy(mtod(n, caddr_t), mtod(m, caddr_t) + off, (unsigned)n->m_len); if (len != M_COPYALL) len -= n->m_len; off += n->m_len; #ifdef DIAGNOSTIC if (off > m->m_len) panic("m_copym0 overrun"); #endif if (off == m->m_len) { m = m->m_next; off = 0; } np = &n->m_next; } return (top); nospace: m_freem(top); return (NULL); } /* * Copy data from an mbuf chain starting "off" bytes from the beginning, * continuing for "len" bytes, into the indicated buffer. */ void m_copydata(struct mbuf *m, int off, int len, caddr_t cp) { unsigned count; if (off < 0) panic("m_copydata: off %d < 0", off); if (len < 0) panic("m_copydata: len %d < 0", len); if ((m = m_getptr(m, off, &off)) == NULL) panic("m_copydata: short mbuf chain"); while (len > 0) { if (m == NULL) panic("m_copydata: null mbuf"); 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; } } /* * Copy data from a buffer back into the indicated mbuf chain, * starting "off" bytes from the beginning, extending the mbuf * chain if necessary. The mbuf needs to be properly initialized * including the setting of m_len. */ void m_copyback(struct mbuf *m0, int off, int len, const void *_cp) { int mlen, totlen = 0; struct mbuf *m = m0, *n; caddr_t cp = (caddr_t)_cp; if (m0 == NULL) return; while (off > (mlen = m->m_len)) { off -= mlen; totlen += mlen; if (m->m_next == NULL) { if ((n = m_get(M_DONTWAIT, m->m_type)) == NULL) goto out; if (off + len > MLEN) { MCLGETI(n, M_DONTWAIT, NULL, off + len); if (!(n->m_flags & M_EXT)) { m_free(n); goto out; } } bzero(mtod(n, caddr_t), off); n->m_len = len + off; m->m_next = n; } m = m->m_next; } while (len > 0) { /* extend last packet to be filled fully */ if (m->m_next == NULL && (len > m->m_len - off)) m->m_len += min(len - (m->m_len - off), M_TRAILINGSPACE(m)); mlen = min(m->m_len - off, len); bcopy(cp, mtod(m, caddr_t) + off, (size_t)mlen); cp += mlen; len -= mlen; totlen += mlen + off; if (len == 0) break; off = 0; if (m->m_next == NULL) { if ((n = m_get(M_DONTWAIT, m->m_type)) == NULL) goto out; if (len > MLEN) { MCLGETI(n, M_DONTWAIT, NULL, len); if (!(n->m_flags & M_EXT)) { m_free(n); goto out; } } n->m_len = 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; } /* * Concatenate mbuf chain n to m. * n might be copied into m (when n->m_len is small), therefore data portion of * n could be copied into an mbuf of different mbuf type. * Therefore both chains should be of the same type (e.g. MT_DATA). * Any m_pkthdr is not updated. */ void m_cat(struct mbuf *m, struct mbuf *n) { while (m->m_next) m = m->m_next; while (n) { if (M_READONLY(m) || n->m_len > M_TRAILINGSPACE(m)) { /* 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(struct mbuf *mp, int req_len) { int len = req_len; struct mbuf *m; 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 == NULL) 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->m_next) != NULL) m->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. */ struct mbuf * m_pullup(struct mbuf *n, int len) { struct mbuf *m; int count; int space; int s; /* * 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 == NULL) goto bad; m->m_len = 0; if (n->m_flags & M_PKTHDR) M_MOVE_PKTHDR(m, n); } space = &m->m_dat[MLEN] - (m->m_data + m->m_len); s = splnet(); 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_unlocked(n); } while (len > 0 && n); if (len > 0) { (void)m_free_unlocked(m); splx(s); goto bad; } splx(s); m->m_next = n; return (m); bad: m_freem(n); return (NULL); } /* * m_pullup2() works like m_pullup, save that len can be <= MCLBYTES. * m_pullup2() only works on values of len such that MHLEN < len <= MCLBYTES, * it calls m_pullup() for values <= MHLEN. It also only coagulates the * requested number of bytes. (For those of us who expect unwieldy option * headers. * * KEBE SAYS: Remember that dtom() calls with data in clusters does not work! */ struct mbuf * m_pullup2(struct mbuf *n, int len) { struct mbuf *m; int count; if (len <= MHLEN) return m_pullup(n, len); if ((n->m_flags & M_EXT) != 0 && n->m_data + len < &n->m_data[MCLBYTES] && n->m_next) { if (n->m_len >= len) return (n); m = n; n = n->m_next; len -= m->m_len; } else { if (len > MCLBYTES) goto bad; MGET(m, M_DONTWAIT, n->m_type); if (m == NULL) goto bad; MCLGET(m, M_DONTWAIT); if ((m->m_flags & M_EXT) == 0) { m_free(m); goto bad; } m->m_len = 0; if (n->m_flags & M_PKTHDR) { /* Too many adverse side effects. */ /* M_MOVE_PKTHDR(m, n); */ m->m_flags = (n->m_flags & M_COPYFLAGS) | M_EXT | M_CLUSTER; M_MOVE_HDR(m, n); /* n->m_data is cool. */ } } do { count = min(len, 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; 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); return (NULL); } /* * Return a pointer to mbuf/offset of location in mbuf chain. */ struct mbuf * m_getptr(struct mbuf *m, int loc, int *off) { while (loc >= 0) { /* Normal end of search */ if (m->m_len > loc) { *off = loc; return (m); } else { loc -= m->m_len; if (m->m_next == NULL) { if (loc == 0) { /* Point at the end of valid data */ *off = m->m_len; return (m); } else { return (NULL); } } else { m = m->m_next; } } } return (NULL); } /* * Inject a new mbuf chain of length siz in mbuf chain m0 at * position len0. Returns a pointer to the first injected mbuf, or * NULL on failure (m0 is left undisturbed). Note that if there is * enough space for an object of size siz in the appropriate position, * no memory will be allocated. Also, there will be no data movement in * the first len0 bytes (pointers to that will remain valid). * * XXX It is assumed that siz is less than the size of an mbuf at the moment. */ struct mbuf * m_inject(struct mbuf *m0, int len0, int siz, int wait) { struct mbuf *m, *n, *n2 = NULL, *n3; unsigned len = len0, remain; if ((siz >= MHLEN) || (len0 <= 0)) return (NULL); for (m = m0; m && len > m->m_len; m = m->m_next) len -= m->m_len; if (m == NULL) return (NULL); remain = m->m_len - len; if (remain == 0) { if ((m->m_next) && (M_LEADINGSPACE(m->m_next) >= siz)) { m->m_next->m_len += siz; if (m0->m_flags & M_PKTHDR) m0->m_pkthdr.len += siz; m->m_next->m_data -= siz; return m->m_next; } } else { n2 = m_copym2(m, len, remain, wait); if (n2 == NULL) return (NULL); } MGET(n, wait, MT_DATA); if (n == NULL) { if (n2) m_freem(n2); return (NULL); } n->m_len = siz; if (m0->m_flags & M_PKTHDR) m0->m_pkthdr.len += siz; m->m_len -= remain; /* Trim */ if (n2) { for (n3 = n; n3->m_next != NULL; n3 = n3->m_next) ; n3->m_next = n2; } else n3 = n; for (; n3->m_next != NULL; n3 = n3->m_next) ; n3->m_next = m->m_next; m->m_next = n; return n; } /* * 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(struct mbuf *m0, int len0, int wait) { struct mbuf *m, *n; unsigned len = len0, remain, olen; for (m = m0; m && len > m->m_len; m = m->m_next) len -= m->m_len; if (m == NULL) return (NULL); remain = m->m_len - len; if (m0->m_flags & M_PKTHDR) { MGETHDR(n, wait, m0->m_type); if (n == NULL) return (NULL); if (m_dup_pkthdr(n, m0)) { m_freem(n); return (NULL); } n->m_pkthdr.len -= len0; olen = m0->m_pkthdr.len; 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 == NULL) { (void) m_free(n); m0->m_pkthdr.len = olen; return (NULL); } else return (n); } else MH_ALIGN(n, remain); } else if (remain == 0) { n = m->m_next; m->m_next = NULL; return (n); } else { MGET(n, wait, m->m_type); if (n == NULL) return (NULL); M_ALIGN(n, remain); } extpacket: if (m->m_flags & M_EXT) { n->m_ext = m->m_ext; MCLADDREFERENCE(m, n); 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 = NULL; return (n); } /* * Routine to copy from device local memory into mbufs. */ struct mbuf * m_devget(char *buf, int totlen, int off, struct ifnet *ifp, void (*copy)(const void *, void *, size_t)) { struct mbuf *m; struct mbuf *top, **mp; int len; top = NULL; mp = ⊤ if (off < 0 || off > MHLEN) return (NULL); MGETHDR(m, M_DONTWAIT, MT_DATA); if (m == NULL) return (NULL); m->m_pkthdr.rcvif = ifp; m->m_pkthdr.len = totlen; len = MHLEN; while (totlen > 0) { if (top != NULL) { MGET(m, M_DONTWAIT, MT_DATA); if (m == NULL) { m_freem(top); return (NULL); } len = MLEN; } if (totlen + off >= MINCLSIZE) { MCLGET(m, M_DONTWAIT); if (m->m_flags & M_EXT) len = MCLBYTES; } else { /* Place initial small packet/header at end of mbuf. */ if (top == NULL && totlen + off + max_linkhdr <= len) { m->m_data += max_linkhdr; len -= max_linkhdr; } } if (off) { m->m_data += off; len -= off; off = 0; } m->m_len = len = min(totlen, len); if (copy) copy(buf, mtod(m, caddr_t), (size_t)len); else bcopy(buf, mtod(m, caddr_t), (size_t)len); buf += len; *mp = m; mp = &m->m_next; totlen -= len; } return (top); } void m_zero(struct mbuf *m) { while (m) { #ifdef DIAGNOSTIC if (M_READONLY(m)) panic("m_zero: M_READONLY"); #endif /* DIAGNOSTIC */ if (m->m_flags & M_EXT) memset(m->m_ext.ext_buf, 0, m->m_ext.ext_size); else { if (m->m_flags & M_PKTHDR) memset(m->m_pktdat, 0, MHLEN); else memset(m->m_dat, 0, MLEN); } m = m->m_next; } } /* * Apply function f to the data in an mbuf chain starting "off" bytes from the * beginning, continuing for "len" bytes. */ int m_apply(struct mbuf *m, int off, int len, int (*f)(caddr_t, caddr_t, unsigned int), caddr_t fstate) { int rval; unsigned int count; if (len < 0) panic("m_apply: len %d < 0", len); if (off < 0) panic("m_apply: off %d < 0", off); while (off > 0) { if (m == NULL) panic("m_apply: null mbuf in skip"); if (off < m->m_len) break; off -= m->m_len; m = m->m_next; } while (len > 0) { if (m == NULL) panic("m_apply: null mbuf"); count = min(m->m_len - off, len); rval = f(fstate, mtod(m, caddr_t) + off, count); if (rval) return (rval); len -= count; off = 0; m = m->m_next; } return (0); } int m_leadingspace(struct mbuf *m) { if (M_READONLY(m)) return 0; return (m->m_flags & M_EXT ? m->m_data - m->m_ext.ext_buf : m->m_flags & M_PKTHDR ? m->m_data - m->m_pktdat : m->m_data - m->m_dat); } int m_trailingspace(struct mbuf *m) { if (M_READONLY(m)) return 0; return (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)); } /* * Duplicate mbuf pkthdr from from to to. * from must have M_PKTHDR set, and to must be empty. */ int m_dup_pkthdr(struct mbuf *to, struct mbuf *from) { KASSERT(from->m_flags & M_PKTHDR); to->m_flags = (to->m_flags & (M_EXT | M_CLUSTER)); to->m_flags |= (from->m_flags & M_COPYFLAGS); to->m_pkthdr = from->m_pkthdr; SLIST_INIT(&to->m_pkthdr.tags); if (m_tag_copy_chain(to, from)) return (ENOMEM); if ((to->m_flags & M_EXT) == 0) to->m_data = to->m_pktdat; return (0); }