/* $OpenBSD: uipc_mbuf.c,v 1.198 2014/11/05 00:28:15 dlg 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 #include #include #include #include #include #include #include #include #include #ifdef DDB #include #include #endif struct mbstat mbstat; /* mbuf stats */ struct mutex mbstatmtx = MUTEX_INITIALIZER(IPL_NET); struct pool mbpool; /* mbuf pool */ struct pool mtagpool; /* 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]; struct pool *m_clpool(u_int); int max_linkhdr; /* largest link-level header */ int max_protohdr; /* largest protocol header */ int max_hdr; /* largest link+protocol header */ struct mutex m_extref_mtx = MUTEX_INITIALIZER(IPL_NET); void m_extfree(struct mbuf *); struct mbuf *m_copym0(struct mbuf *, int, int, int, int); void nmbclust_update(void); void m_zero(struct mbuf *); const char *mclpool_warnmsg = "WARNING: mclpools limit reached; increase kern.maxclusters"; /* * Initialize the mbuf allocator. */ void mbinit(void) { int i; #if DIAGNOSTIC if (mclsizes[0] != MCLBYTES) panic("mbinit: the smallest cluster size != MCLBYTES"); if (mclsizes[nitems(mclsizes) - 1] != MAXMCLBYTES) panic("mbinit: the largest cluster size != MAXMCLBYTES"); #endif pool_init(&mbpool, MSIZE, 0, 0, 0, "mbufpl", NULL); pool_setipl(&mbpool, IPL_NET); pool_set_constraints(&mbpool, &kp_dma_contig); pool_setlowat(&mbpool, mblowat); pool_init(&mtagpool, PACKET_TAG_MAXSIZE + sizeof(struct m_tag), 0, 0, 0, "mtagpl", NULL); pool_setipl(&mtagpool, IPL_NET); 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_setipl(&mclpools[i], IPL_NET); pool_set_constraints(&mclpools[i], &kp_dma_contig); pool_setlowat(&mclpools[i], mcllowat); } nmbclust_update(); } 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); /* * XXX this needs to be reconsidered. * Setting the high water mark to nmbclust is too high * but we need to have enough spare buffers around so that * allocations in interrupt context don't fail or mclgeti() * drivers may end up with empty rings. */ pool_sethiwat(&mclpools[i], nmbclust); } pool_sethiwat(&mbpool, nmbclust); } /* * Space allocation routines. */ struct mbuf * m_get(int nowait, int type) { struct mbuf *m; m = pool_get(&mbpool, nowait == M_WAIT ? PR_WAITOK : PR_NOWAIT); if (m == NULL) return (NULL); mtx_enter(&mbstatmtx); mbstat.m_mtypes[type]++; mtx_leave(&mbstatmtx); m->m_type = type; m->m_next = NULL; m->m_nextpkt = 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; m = pool_get(&mbpool, nowait == M_WAIT ? PR_WAITOK : PR_NOWAIT); if (m == NULL) return (NULL); mtx_enter(&mbstatmtx); mbstat.m_mtypes[type]++; mtx_leave(&mbstatmtx); m->m_type = type; return (m_inithdr(m)); } struct mbuf * m_inithdr(struct mbuf *m) { /* keep in sync with m_gethdr */ m->m_next = NULL; m->m_nextpkt = NULL; m->m_data = m->m_pktdat; m->m_flags = M_PKTHDR; memset(&m->m_pkthdr, 0, sizeof(m->m_pkthdr)); m->m_pkthdr.pf.prio = IFQ_DEFPRIO; 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); } struct pool * m_clpool(u_int pktlen) { struct pool *pp; int pi; for (pi = 0; pi < nitems(mclpools); pi++) { pp = &mclpools[pi]; if (pktlen <= pp->pr_size) return (pp); } return (NULL); } struct mbuf * m_clget(struct mbuf *m, int how, struct ifnet *ifp, u_int pktlen) { struct mbuf *m0 = NULL; struct pool *pp; caddr_t buf; pp = m_clpool(pktlen); #ifdef DIAGNOSTIC if (pp == NULL) panic("m_clget: request for %u byte cluster", pktlen); #endif if (m == NULL) { m0 = m_gethdr(how, MT_DATA); if (m0 == NULL) return (NULL); m = m0; } buf = pool_get(pp, how == M_WAIT ? PR_WAITOK : PR_NOWAIT); if (buf == NULL) { if (m0) m_freem(m0); return (NULL); } MEXTADD(m, buf, pp->pr_size, M_EXTWR, m_extfree_pool, pp); return (m); } void m_extfree_pool(caddr_t buf, u_int size, void *pp) { pool_put(pp, buf); } struct mbuf * m_free(struct mbuf *m) { struct mbuf *n; mtx_enter(&mbstatmtx); mbstat.m_mtypes[m->m_type]--; mtx_leave(&mbstatmtx); n = m->m_next; if (m->m_flags & M_ZEROIZE) { m_zero(m); /* propagate M_ZEROIZE to the next mbuf in the chain */ if (n) n->m_flags |= M_ZEROIZE; } if (m->m_flags & M_PKTHDR) m_tag_delete_chain(m); if (m->m_flags & M_EXT) m_extfree(m); pool_put(&mbpool, m); return (n); } void m_extref(struct mbuf *o, struct mbuf *n) { int refs = MCLISREFERENCED(o); n->m_flags |= o->m_flags & (M_EXT|M_EXTWR); if (refs) mtx_enter(&m_extref_mtx); n->m_ext.ext_nextref = o->m_ext.ext_nextref; n->m_ext.ext_prevref = o; o->m_ext.ext_nextref = n; n->m_ext.ext_nextref->m_ext.ext_prevref = n; if (refs) mtx_leave(&m_extref_mtx); MCLREFDEBUGN((n), __FILE__, __LINE__); } static inline u_int m_extunref(struct mbuf *m) { int refs = 1; if (!MCLISREFERENCED(m)) return (0); mtx_enter(&m_extref_mtx); 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 refs = 0; mtx_leave(&m_extref_mtx); return (refs); } void m_extfree(struct mbuf *m) { if (m_extunref(m) == 0) { (*(m->m_ext.ext_free))(m->m_ext.ext_buf, m->m_ext.ext_size, m->m_ext.ext_arg); } m->m_flags &= ~(M_EXT|M_EXTWR); } void m_freem(struct mbuf *m) { while (m != NULL) m = m_free(m); } /* * 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 (ENOBUFS); if (m->m_pkthdr.len > MHLEN) { MCLGETI(m0, how, NULL, m->m_pkthdr.len); if (!(m0->m_flags & M_EXT)) { m_free(m0); return (ENOBUFS); } } 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) m_extfree(m); /* * 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) { memcpy(&m->m_ext, &m0->m_ext, sizeof(struct mbuf_ext)); MCLINITREFERENCE(m); m->m_flags |= m0->m_flags & (M_EXT|M_EXTWR); m->m_data = m->m_ext.ext_buf; } else { m->m_data = m->m_pktdat; memcpy(m->m_data, m0->m_data, m0->m_len); } m->m_pkthdr.len = m->m_len = m0->m_len; m0->m_flags &= ~(M_EXT|M_EXTWR); /* 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 *m0, int off, int len, int wait, int deep) { struct mbuf *m, *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 && m0->m_flags & M_PKTHDR) copyhdr = 1; if ((m = m_getptr(m0, 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, m0, wait)) 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, n->m_len); } } else memcpy(mtod(n, caddr_t), mtod(m, caddr_t) + off, 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. */ int m_copyback(struct mbuf *m0, int off, int len, const void *_cp, int wait) { int mlen, totlen = 0; struct mbuf *m = m0, *n; caddr_t cp = (caddr_t)_cp; int error = 0; if (m0 == NULL) return (0); while (off > (mlen = m->m_len)) { off -= mlen; totlen += mlen; if (m->m_next == NULL) { if ((n = m_get(wait, m->m_type)) == NULL) { error = ENOBUFS; goto out; } if (off + len > MLEN) { MCLGETI(n, wait, NULL, off + len); if (!(n->m_flags & M_EXT)) { m_free(n); error = ENOBUFS; goto out; } } memset(mtod(n, caddr_t), 0, 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(wait, m->m_type)) == NULL) { error = ENOBUFS; goto out; } if (len > MLEN) { MCLGETI(n, wait, NULL, len); if (!(n->m_flags & M_EXT)) { m_free(n); error = ENOBUFS; 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; return (error); } /* * 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; } } if (mp->m_flags & M_PKTHDR) mp->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; } } /* * Rearrange an mbuf chain so that len bytes are contiguous * and in the data area of an mbuf (so that mtod will work * for a structure of size len). Returns the resulting * mbuf chain on success, frees it and returns null on failure. */ struct mbuf * m_pullup(struct mbuf *n, int len) { struct mbuf *m; int count; /* * 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_next && n->m_data + len < &n->m_dat[MLEN]) { if (n->m_len >= len) return (n); m = n; n = n->m_next; len -= m->m_len; } else if ((n->m_flags & M_EXT) != 0 && len > MHLEN && n->m_next && n->m_data + len < &n->m_ext.ext_buf[n->m_ext.ext_size]) { if (n->m_len >= len) return (n); m = n; n = n->m_next; len -= m->m_len; } else { if (len > MAXMCLBYTES) goto bad; MGET(m, M_DONTWAIT, n->m_type); if (m == NULL) goto bad; if (len > MHLEN) { MCLGETI(m, M_DONTWAIT, NULL, len); if ((m->m_flags & M_EXT) == 0) { m_free(m); goto bad; } } m->m_len = 0; if (n->m_flags & M_PKTHDR) M_MOVE_PKTHDR(m, n); } 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, wait)) { 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) { 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) { /* * As we might get called by pfkey, make sure * we do not leak sensitive data. */ top->m_flags |= M_ZEROIZE; 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); memcpy(mtod(m, void *), buf, (size_t)len); buf += len; *mp = m; mp = &m->m_next; totlen -= len; } return (top); } void m_zero(struct mbuf *m) { #ifdef DIAGNOSTIC if (M_READONLY(m)) panic("m_zero: M_READONLY"); #endif /* DIAGNOSTIC */ if (m->m_flags & M_EXT) explicit_bzero(m->m_ext.ext_buf, m->m_ext.ext_size); else { if (m->m_flags & M_PKTHDR) explicit_bzero(m->m_pktdat, MHLEN); else explicit_bzero(m->m_dat, MLEN); } } /* * 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, int wait) { int error; KASSERT(from->m_flags & M_PKTHDR); to->m_flags = (to->m_flags & (M_EXT | M_EXTWR)); to->m_flags |= (from->m_flags & M_COPYFLAGS); to->m_pkthdr = from->m_pkthdr; SLIST_INIT(&to->m_pkthdr.tags); if ((error = m_tag_copy_chain(to, from, wait)) != 0) return (error); if ((to->m_flags & M_EXT) == 0) to->m_data = to->m_pktdat; return (0); } #ifdef DDB void m_print(void *v, int (*pr)(const char *, ...) __attribute__((__format__(__kprintf__,1,2)))) { struct mbuf *m = v; (*pr)("mbuf %p\n", m); (*pr)("m_type: %i\tm_flags: %b\n", m->m_type, m->m_flags, M_BITS); (*pr)("m_next: %p\tm_nextpkt: %p\n", m->m_next, m->m_nextpkt); (*pr)("m_data: %p\tm_len: %u\n", m->m_data, m->m_len); (*pr)("m_dat: %p\tm_pktdat: %p\n", m->m_dat, m->m_pktdat); if (m->m_flags & M_PKTHDR) { (*pr)("m_ptkhdr.rcvif: %p\tm_pkthdr.len: %i\n", m->m_pkthdr.rcvif, m->m_pkthdr.len); (*pr)("m_ptkhdr.tags: %p\tm_pkthdr.tagsset: %b\n", SLIST_FIRST(&m->m_pkthdr.tags), m->m_pkthdr.tagsset, MTAG_BITS); (*pr)("m_pkthdr.csum_flags: %b\n", m->m_pkthdr.csum_flags, MCS_BITS); (*pr)("m_pkthdr.ether_vtag: %u\tm_ptkhdr.ph_rtableid: %u\n", m->m_pkthdr.ether_vtag, m->m_pkthdr.ph_rtableid); (*pr)("m_pkthdr.pf.statekey: %p\tm_pkthdr.pf.inp %p\n", m->m_pkthdr.pf.statekey, m->m_pkthdr.pf.inp); (*pr)("m_pkthdr.pf.qid: %u\tm_pkthdr.pf.tag: %u\n", m->m_pkthdr.pf.qid, m->m_pkthdr.pf.tag); (*pr)("m_pkthdr.pf.flags: %b\n", m->m_pkthdr.pf.flags, MPF_BITS); (*pr)("m_pkthdr.pf.routed: %u\tm_pkthdr.pf.prio: %u\n", m->m_pkthdr.pf.routed, m->m_pkthdr.pf.prio); } if (m->m_flags & M_EXT) { (*pr)("m_ext.ext_buf: %p\tm_ext.ext_size: %u\n", m->m_ext.ext_buf, m->m_ext.ext_size); (*pr)("m_ext.ext_free: %p\tm_ext.ext_arg: %p\n", m->m_ext.ext_free, m->m_ext.ext_arg); (*pr)("m_ext.ext_nextref: %p\tm_ext.ext_prevref: %p\n", m->m_ext.ext_nextref, m->m_ext.ext_prevref); } } #endif /* * mbuf lists */ void ml_join(struct mbuf_list *, struct mbuf_list *); void ml_init(struct mbuf_list *ml) { ml->ml_head = ml->ml_tail = NULL; ml->ml_len = 0; } void ml_enqueue(struct mbuf_list *ml, struct mbuf *m) { if (ml->ml_tail == NULL) ml->ml_head = ml->ml_tail = m; else { ml->ml_tail->m_nextpkt = m; ml->ml_tail = m; } m->m_nextpkt = NULL; ml->ml_len++; } void ml_join(struct mbuf_list *mla, struct mbuf_list *mlb) { if (mla->ml_tail == NULL) *mla = *mlb; else if (mlb->ml_tail != NULL) { mla->ml_tail->m_nextpkt = mlb->ml_head; mla->ml_tail = mlb->ml_tail; mla->ml_len += mlb->ml_len; ml_init(mlb); } } struct mbuf * ml_dequeue(struct mbuf_list *ml) { struct mbuf *m; m = ml->ml_head; if (m != NULL) { ml->ml_head = m->m_nextpkt; if (ml->ml_head == NULL) ml->ml_tail = NULL; m->m_nextpkt = NULL; ml->ml_len--; } return (m); } struct mbuf * ml_dechain(struct mbuf_list *ml) { struct mbuf *m0; m0 = ml->ml_head; ml_init(ml); return (m0); } /* * mbuf queues */ void mq_init(struct mbuf_queue *mq, u_int maxlen, int ipl) { mtx_init(&mq->mq_mtx, ipl); ml_init(&mq->mq_list); mq->mq_maxlen = maxlen; } int mq_enqueue(struct mbuf_queue *mq, struct mbuf *m) { int dropped = 0; mtx_enter(&mq->mq_mtx); if (mq_len(mq) < mq->mq_maxlen) ml_enqueue(&mq->mq_list, m); else { mq->mq_drops++; dropped = 1; } mtx_leave(&mq->mq_mtx); if (dropped) m_freem(m); return (dropped); } struct mbuf * mq_dequeue(struct mbuf_queue *mq) { struct mbuf *m; mtx_enter(&mq->mq_mtx); m = ml_dequeue(&mq->mq_list); mtx_leave(&mq->mq_mtx); return (m); } int mq_enlist(struct mbuf_queue *mq, struct mbuf_list *ml) { int full; mtx_enter(&mq->mq_mtx); ml_join(&mq->mq_list, ml); full = mq_len(mq) >= mq->mq_maxlen; mtx_leave(&mq->mq_mtx); return (full); } void mq_delist(struct mbuf_queue *mq, struct mbuf_list *ml) { mtx_enter(&mq->mq_mtx); *ml = mq->mq_list; ml_init(&mq->mq_list); mtx_leave(&mq->mq_mtx); } struct mbuf * mq_dechain(struct mbuf_queue *mq) { struct mbuf *m0; mtx_enter(&mq->mq_mtx); m0 = ml_dechain(&mq->mq_list); mtx_leave(&mq->mq_mtx); return (m0); }