uipc_mbuf.c revision 130357
11541Srgrimes/* 21541Srgrimes * Copyright (c) 1982, 1986, 1988, 1991, 1993 31541Srgrimes * The Regents of the University of California. All rights reserved. 41541Srgrimes * 51541Srgrimes * Redistribution and use in source and binary forms, with or without 61541Srgrimes * modification, are permitted provided that the following conditions 71541Srgrimes * are met: 81541Srgrimes * 1. Redistributions of source code must retain the above copyright 91541Srgrimes * notice, this list of conditions and the following disclaimer. 101541Srgrimes * 2. Redistributions in binary form must reproduce the above copyright 111541Srgrimes * notice, this list of conditions and the following disclaimer in the 121541Srgrimes * documentation and/or other materials provided with the distribution. 131541Srgrimes * 4. Neither the name of the University nor the names of its contributors 141541Srgrimes * may be used to endorse or promote products derived from this software 151541Srgrimes * without specific prior written permission. 161541Srgrimes * 171541Srgrimes * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 181541Srgrimes * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 191541Srgrimes * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 201541Srgrimes * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 211541Srgrimes * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 221541Srgrimes * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 231541Srgrimes * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 241541Srgrimes * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 251541Srgrimes * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 261541Srgrimes * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 271541Srgrimes * SUCH DAMAGE. 281541Srgrimes * 291541Srgrimes * @(#)uipc_mbuf.c 8.2 (Berkeley) 1/4/94 301541Srgrimes */ 311541Srgrimes 32116182Sobrien#include <sys/cdefs.h> 33116182Sobrien__FBSDID("$FreeBSD: head/sys/kern/uipc_mbuf.c 130357 2004-06-11 18:17:25Z bmilekic $"); 34116182Sobrien 35101007Srwatson#include "opt_mac.h" 3677572Sobrien#include "opt_param.h" 37113490Ssilby#include "opt_mbuf_stress_test.h" 38101007Srwatson 391541Srgrimes#include <sys/param.h> 401541Srgrimes#include <sys/systm.h> 4176166Smarkm#include <sys/kernel.h> 42125296Ssilby#include <sys/limits.h> 4376166Smarkm#include <sys/lock.h> 44101173Srwatson#include <sys/mac.h> 4532036Sbde#include <sys/malloc.h> 461541Srgrimes#include <sys/mbuf.h> 4723081Swollman#include <sys/sysctl.h> 481541Srgrimes#include <sys/domain.h> 491541Srgrimes#include <sys/protosw.h> 50125296Ssilby#include <sys/uio.h> 5176166Smarkm 529759Sbdeint max_linkhdr; 539759Sbdeint max_protohdr; 549759Sbdeint max_hdr; 559759Sbdeint max_datalen; 56116455Ssilby#ifdef MBUF_STRESS_TEST 57112777Ssilbyint m_defragpackets; 58112777Ssilbyint m_defragbytes; 59112777Ssilbyint m_defraguseless; 60112777Ssilbyint m_defragfailure; 61113490Ssilbyint m_defragrandomfailures; 62113490Ssilby#endif 631541Srgrimes 6466475Sbmilekic/* 6566475Sbmilekic * sysctl(8) exported objects 6666475Sbmilekic */ 6744078SdfrSYSCTL_DECL(_kern_ipc); 6823081SwollmanSYSCTL_INT(_kern_ipc, KIPC_MAX_LINKHDR, max_linkhdr, CTLFLAG_RW, 6923081Swollman &max_linkhdr, 0, ""); 7023081SwollmanSYSCTL_INT(_kern_ipc, KIPC_MAX_PROTOHDR, max_protohdr, CTLFLAG_RW, 7123081Swollman &max_protohdr, 0, ""); 7223081SwollmanSYSCTL_INT(_kern_ipc, KIPC_MAX_HDR, max_hdr, CTLFLAG_RW, &max_hdr, 0, ""); 7323081SwollmanSYSCTL_INT(_kern_ipc, KIPC_MAX_DATALEN, max_datalen, CTLFLAG_RW, 7423081Swollman &max_datalen, 0, ""); 75116455Ssilby#ifdef MBUF_STRESS_TEST 76112777SsilbySYSCTL_INT(_kern_ipc, OID_AUTO, m_defragpackets, CTLFLAG_RD, 77112777Ssilby &m_defragpackets, 0, ""); 78112777SsilbySYSCTL_INT(_kern_ipc, OID_AUTO, m_defragbytes, CTLFLAG_RD, 79112777Ssilby &m_defragbytes, 0, ""); 80112777SsilbySYSCTL_INT(_kern_ipc, OID_AUTO, m_defraguseless, CTLFLAG_RD, 81112777Ssilby &m_defraguseless, 0, ""); 82112777SsilbySYSCTL_INT(_kern_ipc, OID_AUTO, m_defragfailure, CTLFLAG_RD, 83112777Ssilby &m_defragfailure, 0, ""); 84113490SsilbySYSCTL_INT(_kern_ipc, OID_AUTO, m_defragrandomfailures, CTLFLAG_RW, 85113490Ssilby &m_defragrandomfailures, 0, ""); 86113490Ssilby#endif 8775112Sbmilekic 881541Srgrimes/* 89129906Sbmilekic * Malloc-type for external ext_buf ref counts. 90129906Sbmilekic */ 91129906SbmilekicMALLOC_DEFINE(M_MBUF, "mbextcnt", "mbuf external ref counts"); 92129906Sbmilekic 93129906Sbmilekic/* 94129906Sbmilekic * Allocate a given length worth of mbufs and/or clusters (whatever fits 95129906Sbmilekic * best) and return a pointer to the top of the allocated chain. If an 96129906Sbmilekic * existing mbuf chain is provided, then we will append the new chain 97129906Sbmilekic * to the existing one but still return the top of the newly allocated 98129906Sbmilekic * chain. 99129906Sbmilekic */ 100129906Sbmilekicstruct mbuf * 101129906Sbmilekicm_getm(struct mbuf *m, int len, int how, short type) 102129906Sbmilekic{ 103129906Sbmilekic struct mbuf *mb, *top, *cur, *mtail; 104129906Sbmilekic int num, rem; 105129906Sbmilekic int i; 106129906Sbmilekic 107129906Sbmilekic KASSERT(len >= 0, ("m_getm(): len is < 0")); 108129906Sbmilekic 109129906Sbmilekic /* If m != NULL, we will append to the end of that chain. */ 110129906Sbmilekic if (m != NULL) 111129906Sbmilekic for (mtail = m; mtail->m_next != NULL; mtail = mtail->m_next); 112129906Sbmilekic else 113129906Sbmilekic mtail = NULL; 114129906Sbmilekic 115129906Sbmilekic /* 116129906Sbmilekic * Calculate how many mbufs+clusters ("packets") we need and how much 117129906Sbmilekic * leftover there is after that and allocate the first mbuf+cluster 118129906Sbmilekic * if required. 119129906Sbmilekic */ 120129906Sbmilekic num = len / MCLBYTES; 121129906Sbmilekic rem = len % MCLBYTES; 122129906Sbmilekic top = cur = NULL; 123129906Sbmilekic if (num > 0) { 124129906Sbmilekic if ((top = cur = m_getcl(how, type, 0)) == NULL) 125129906Sbmilekic goto failed; 126130271Smux top->m_len = 0; 127129906Sbmilekic } 128129906Sbmilekic num--; 129129906Sbmilekic 130129906Sbmilekic for (i = 0; i < num; i++) { 131129906Sbmilekic mb = m_getcl(how, type, 0); 132129906Sbmilekic if (mb == NULL) 133129906Sbmilekic goto failed; 134129906Sbmilekic mb->m_len = 0; 135129906Sbmilekic cur = (cur->m_next = mb); 136129906Sbmilekic } 137129906Sbmilekic if (rem > 0) { 138129906Sbmilekic mb = (rem > MINCLSIZE) ? 139129906Sbmilekic m_getcl(how, type, 0) : m_get(how, type); 140129906Sbmilekic if (mb == NULL) 141129906Sbmilekic goto failed; 142129906Sbmilekic mb->m_len = 0; 143129906Sbmilekic if (cur == NULL) 144129906Sbmilekic top = mb; 145129906Sbmilekic else 146129906Sbmilekic cur->m_next = mb; 147129906Sbmilekic } 148129906Sbmilekic 149129906Sbmilekic if (mtail != NULL) 150129906Sbmilekic mtail->m_next = top; 151129906Sbmilekic return top; 152129906Sbmilekicfailed: 153129906Sbmilekic if (top != NULL) 154129906Sbmilekic m_freem(top); 155129906Sbmilekic return NULL; 156129906Sbmilekic} 157129906Sbmilekic 158129906Sbmilekic/* 159129906Sbmilekic * Free an entire chain of mbufs and associated external buffers, if 160129906Sbmilekic * applicable. 161129906Sbmilekic */ 162129906Sbmilekicvoid 163129906Sbmilekicm_freem(struct mbuf *mb) 164129906Sbmilekic{ 165129906Sbmilekic 166129906Sbmilekic while (mb != NULL) 167129906Sbmilekic mb = m_free(mb); 168129906Sbmilekic} 169129906Sbmilekic 170129906Sbmilekic/*- 171129906Sbmilekic * Configure a provided mbuf to refer to the provided external storage 172129906Sbmilekic * buffer and setup a reference count for said buffer. If the setting 173129906Sbmilekic * up of the reference count fails, the M_EXT bit will not be set. If 174129906Sbmilekic * successfull, the M_EXT bit is set in the mbuf's flags. 175129906Sbmilekic * 176129906Sbmilekic * Arguments: 177129906Sbmilekic * mb The existing mbuf to which to attach the provided buffer. 178129906Sbmilekic * buf The address of the provided external storage buffer. 179129906Sbmilekic * size The size of the provided buffer. 180129906Sbmilekic * freef A pointer to a routine that is responsible for freeing the 181129906Sbmilekic * provided external storage buffer. 182129906Sbmilekic * args A pointer to an argument structure (of any type) to be passed 183129906Sbmilekic * to the provided freef routine (may be NULL). 184129906Sbmilekic * flags Any other flags to be passed to the provided mbuf. 185129906Sbmilekic * type The type that the external storage buffer should be 186129906Sbmilekic * labeled with. 187129906Sbmilekic * 188129906Sbmilekic * Returns: 189129906Sbmilekic * Nothing. 190129906Sbmilekic */ 191129906Sbmilekicvoid 192129906Sbmilekicm_extadd(struct mbuf *mb, caddr_t buf, u_int size, 193129906Sbmilekic void (*freef)(void *, void *), void *args, int flags, int type) 194129906Sbmilekic{ 195129906Sbmilekic u_int *ref_cnt = NULL; 196129906Sbmilekic 197129906Sbmilekic /* XXX Shouldn't be adding EXT_CLUSTER with this API */ 198129906Sbmilekic if (type == EXT_CLUSTER) 199129906Sbmilekic ref_cnt = (u_int *)uma_find_refcnt(zone_clust, 200129906Sbmilekic mb->m_ext.ext_buf); 201129906Sbmilekic else if (type == EXT_EXTREF) 202129906Sbmilekic ref_cnt = mb->m_ext.ref_cnt; 203129906Sbmilekic mb->m_ext.ref_cnt = (ref_cnt == NULL) ? 204129906Sbmilekic malloc(sizeof(u_int), M_MBUF, M_NOWAIT) : (u_int *)ref_cnt; 205129906Sbmilekic if (mb->m_ext.ref_cnt != NULL) { 206129906Sbmilekic *(mb->m_ext.ref_cnt) = 1; 207129906Sbmilekic mb->m_flags |= (M_EXT | flags); 208129906Sbmilekic mb->m_ext.ext_buf = buf; 209129906Sbmilekic mb->m_data = mb->m_ext.ext_buf; 210129906Sbmilekic mb->m_ext.ext_size = size; 211129906Sbmilekic mb->m_ext.ext_free = freef; 212129906Sbmilekic mb->m_ext.ext_args = args; 213129906Sbmilekic mb->m_ext.ext_type = type; 214129906Sbmilekic } 215129906Sbmilekic} 216129906Sbmilekic 217129906Sbmilekic/* 218129906Sbmilekic * Non-directly-exported function to clean up after mbufs with M_EXT 219129906Sbmilekic * storage attached to them if the reference count hits 0. 220129906Sbmilekic */ 221129906Sbmilekicvoid 222129906Sbmilekicmb_free_ext(struct mbuf *m) 223129906Sbmilekic{ 224130289Sbmilekic u_int cnt; 225129906Sbmilekic 226130289Sbmilekic /* 227130289Sbmilekic * This is tricky. We need to make sure to decrement the 228130289Sbmilekic * refcount in a safe way but to also clean up if we're the 229130289Sbmilekic * last reference. This method seems to do it without race. 230130289Sbmilekic */ 231130289Sbmilekic do { 232130289Sbmilekic cnt = *(m->m_ext.ref_cnt); 233130289Sbmilekic if (atomic_cmpset_int(m->m_ext.ref_cnt, cnt, cnt - 1)) { 234130289Sbmilekic if (cnt == 1) { 235130289Sbmilekic /* 236130289Sbmilekic * Do the free, should be safe. 237130289Sbmilekic */ 238130289Sbmilekic if (m->m_ext.ext_type == EXT_PACKET) { 239130289Sbmilekic uma_zfree(zone_pack, m); 240130357Sbmilekic return; 241130289Sbmilekic } else if (m->m_ext.ext_type == EXT_CLUSTER) { 242130289Sbmilekic uma_zfree(zone_clust, m->m_ext.ext_buf); 243130289Sbmilekic m->m_ext.ext_buf = NULL; 244130289Sbmilekic } else { 245130289Sbmilekic (*(m->m_ext.ext_free))(m->m_ext.ext_buf, 246130289Sbmilekic m->m_ext.ext_args); 247130289Sbmilekic if (m->m_ext.ext_type != EXT_EXTREF) 248130289Sbmilekic free(m->m_ext.ref_cnt, M_MBUF); 249130357Sbmilekic m->m_ext.ext_buf = NULL; 250130289Sbmilekic } 251130289Sbmilekic } 252130289Sbmilekic /* Decrement (and potentially free) done, safely. */ 253130289Sbmilekic break; 254129906Sbmilekic } 255130289Sbmilekic } while (1); 256130357Sbmilekic uma_zfree(zone_mbuf, m); 257129906Sbmilekic} 258129906Sbmilekic 259129906Sbmilekic/* 260108466Ssam * "Move" mbuf pkthdr from "from" to "to". 261100960Srwatson * "from" must have M_PKTHDR set, and "to" must be empty. 262100960Srwatson */ 263100960Srwatsonvoid 264108466Ssamm_move_pkthdr(struct mbuf *to, struct mbuf *from) 265100960Srwatson{ 266100960Srwatson 267100960Srwatson#if 0 268108466Ssam /* see below for why these are not enabled */ 269113255Sdes M_ASSERTPKTHDR(to); 270113487Srwatson /* Note: with MAC, this may not be a good assertion. */ 271108466Ssam KASSERT(SLIST_EMPTY(&to->m_pkthdr.tags), 272108466Ssam ("m_move_pkthdr: to has tags")); 273100960Srwatson#endif 274108466Ssam KASSERT((to->m_flags & M_EXT) == 0, ("m_move_pkthdr: to has cluster")); 275101007Srwatson#ifdef MAC 276113487Srwatson /* 277113487Srwatson * XXXMAC: It could be this should also occur for non-MAC? 278113487Srwatson */ 279101007Srwatson if (to->m_flags & M_PKTHDR) 280113487Srwatson m_tag_delete_chain(to, NULL); 281101007Srwatson#endif 282108466Ssam to->m_flags = from->m_flags & M_COPYFLAGS; 283100960Srwatson to->m_data = to->m_pktdat; 284108466Ssam to->m_pkthdr = from->m_pkthdr; /* especially tags */ 285108466Ssam SLIST_INIT(&from->m_pkthdr.tags); /* purge tags from src */ 286108466Ssam from->m_flags &= ~M_PKTHDR; 287108466Ssam} 288108466Ssam 289108466Ssam/* 290108466Ssam * Duplicate "from"'s mbuf pkthdr in "to". 291108466Ssam * "from" must have M_PKTHDR set, and "to" must be empty. 292108466Ssam * In particular, this does a deep copy of the packet tags. 293108466Ssam */ 294108466Ssamint 295108466Ssamm_dup_pkthdr(struct mbuf *to, struct mbuf *from, int how) 296108466Ssam{ 297108466Ssam 298108466Ssam#if 0 299108466Ssam /* 300108466Ssam * The mbuf allocator only initializes the pkthdr 301108466Ssam * when the mbuf is allocated with MGETHDR. Many users 302108466Ssam * (e.g. m_copy*, m_prepend) use MGET and then 303108466Ssam * smash the pkthdr as needed causing these 304108466Ssam * assertions to trip. For now just disable them. 305108466Ssam */ 306113255Sdes M_ASSERTPKTHDR(to); 307113487Srwatson /* Note: with MAC, this may not be a good assertion. */ 308108466Ssam KASSERT(SLIST_EMPTY(&to->m_pkthdr.tags), ("m_dup_pkthdr: to has tags")); 309108466Ssam#endif 310108466Ssam#ifdef MAC 311108466Ssam if (to->m_flags & M_PKTHDR) 312113487Srwatson m_tag_delete_chain(to, NULL); 313108466Ssam#endif 314112733Ssilby to->m_flags = (from->m_flags & M_COPYFLAGS) | (to->m_flags & M_EXT); 315112733Ssilby if ((to->m_flags & M_EXT) == 0) 316112733Ssilby to->m_data = to->m_pktdat; 317100960Srwatson to->m_pkthdr = from->m_pkthdr; 318108466Ssam SLIST_INIT(&to->m_pkthdr.tags); 319113480Srwatson return (m_tag_copy_chain(to, from, MBTOM(how))); 320100960Srwatson} 321100960Srwatson 322100960Srwatson/* 3231541Srgrimes * Lesser-used path for M_PREPEND: 3241541Srgrimes * allocate new mbuf to prepend to chain, 3251541Srgrimes * copy junk along. 3261541Srgrimes */ 3271541Srgrimesstruct mbuf * 32872356Sbmilekicm_prepend(struct mbuf *m, int len, int how) 3291541Srgrimes{ 3301541Srgrimes struct mbuf *mn; 3311541Srgrimes 332117770Ssilby if (m->m_flags & M_PKTHDR) 333117770Ssilby MGETHDR(mn, how, m->m_type); 334117770Ssilby else 335117770Ssilby MGET(mn, how, m->m_type); 33672356Sbmilekic if (mn == NULL) { 3371541Srgrimes m_freem(m); 33872356Sbmilekic return (NULL); 3391541Srgrimes } 340113487Srwatson if (m->m_flags & M_PKTHDR) 341108466Ssam M_MOVE_PKTHDR(mn, m); 3421541Srgrimes mn->m_next = m; 3431541Srgrimes m = mn; 3441541Srgrimes if (len < MHLEN) 3451541Srgrimes MH_ALIGN(m, len); 3461541Srgrimes m->m_len = len; 3471541Srgrimes return (m); 3481541Srgrimes} 3491541Srgrimes 3501541Srgrimes/* 3511541Srgrimes * Make a copy of an mbuf chain starting "off0" bytes from the beginning, 3521541Srgrimes * continuing for "len" bytes. If len is M_COPYALL, copy to end of mbuf. 353111119Simp * The wait parameter is a choice of M_TRYWAIT/M_DONTWAIT from caller. 35454002Sarchie * Note that the copy is read-only, because clusters are not copied, 35554002Sarchie * only their reference counts are incremented. 3561541Srgrimes */ 3571541Srgrimesstruct mbuf * 35872356Sbmilekicm_copym(struct mbuf *m, int off0, int len, int wait) 3591541Srgrimes{ 36072356Sbmilekic struct mbuf *n, **np; 36172356Sbmilekic int off = off0; 3621541Srgrimes struct mbuf *top; 3631541Srgrimes int copyhdr = 0; 3641541Srgrimes 36552201Salfred KASSERT(off >= 0, ("m_copym, negative off %d", off)); 36652201Salfred KASSERT(len >= 0, ("m_copym, negative len %d", len)); 3671541Srgrimes if (off == 0 && m->m_flags & M_PKTHDR) 3681541Srgrimes copyhdr = 1; 3691541Srgrimes while (off > 0) { 37052201Salfred KASSERT(m != NULL, ("m_copym, offset > size of mbuf chain")); 3711541Srgrimes if (off < m->m_len) 3721541Srgrimes break; 3731541Srgrimes off -= m->m_len; 3741541Srgrimes m = m->m_next; 3751541Srgrimes } 3761541Srgrimes np = ⊤ 3771541Srgrimes top = 0; 3781541Srgrimes while (len > 0) { 37972356Sbmilekic if (m == NULL) { 38052201Salfred KASSERT(len == M_COPYALL, 38152201Salfred ("m_copym, length > size of mbuf chain")); 3821541Srgrimes break; 3831541Srgrimes } 384117770Ssilby if (copyhdr) 385117770Ssilby MGETHDR(n, wait, m->m_type); 386117770Ssilby else 387117770Ssilby MGET(n, wait, m->m_type); 3881541Srgrimes *np = n; 38972356Sbmilekic if (n == NULL) 3901541Srgrimes goto nospace; 3911541Srgrimes if (copyhdr) { 392108466Ssam if (!m_dup_pkthdr(n, m, wait)) 393108466Ssam goto nospace; 3941541Srgrimes if (len == M_COPYALL) 3951541Srgrimes n->m_pkthdr.len -= off0; 3961541Srgrimes else 3971541Srgrimes n->m_pkthdr.len = len; 3981541Srgrimes copyhdr = 0; 3991541Srgrimes } 4001541Srgrimes n->m_len = min(len, m->m_len - off); 4011541Srgrimes if (m->m_flags & M_EXT) { 4021541Srgrimes n->m_data = m->m_data + off; 4031541Srgrimes n->m_ext = m->m_ext; 4041541Srgrimes n->m_flags |= M_EXT; 40564837Sdwmalone MEXT_ADD_REF(m); 4061541Srgrimes } else 4071541Srgrimes bcopy(mtod(m, caddr_t)+off, mtod(n, caddr_t), 408103569Sbmilekic (u_int)n->m_len); 4091541Srgrimes if (len != M_COPYALL) 4101541Srgrimes len -= n->m_len; 4111541Srgrimes off = 0; 4121541Srgrimes m = m->m_next; 4131541Srgrimes np = &n->m_next; 4141541Srgrimes } 41578592Sbmilekic if (top == NULL) 41678592Sbmilekic mbstat.m_mcfail++; /* XXX: No consistency. */ 41778592Sbmilekic 4181541Srgrimes return (top); 4191541Srgrimesnospace: 4201541Srgrimes m_freem(top); 42178592Sbmilekic mbstat.m_mcfail++; /* XXX: No consistency. */ 42272356Sbmilekic return (NULL); 4231541Srgrimes} 4241541Srgrimes 4251541Srgrimes/* 42615689Swollman * Copy an entire packet, including header (which must be present). 42715689Swollman * An optimization of the common case `m_copym(m, 0, M_COPYALL, how)'. 42854002Sarchie * Note that the copy is read-only, because clusters are not copied, 42954002Sarchie * only their reference counts are incremented. 43072750Sluigi * Preserve alignment of the first mbuf so if the creator has left 43172750Sluigi * some room at the beginning (e.g. for inserting protocol headers) 43272750Sluigi * the copies still have the room available. 43315689Swollman */ 43415689Swollmanstruct mbuf * 43572356Sbmilekicm_copypacket(struct mbuf *m, int how) 43615689Swollman{ 43715689Swollman struct mbuf *top, *n, *o; 43815689Swollman 43915689Swollman MGET(n, how, m->m_type); 44015689Swollman top = n; 44172356Sbmilekic if (n == NULL) 44215689Swollman goto nospace; 44315689Swollman 444108466Ssam if (!m_dup_pkthdr(n, m, how)) 445108466Ssam goto nospace; 44615689Swollman n->m_len = m->m_len; 44715689Swollman if (m->m_flags & M_EXT) { 44815689Swollman n->m_data = m->m_data; 44915689Swollman n->m_ext = m->m_ext; 45015689Swollman n->m_flags |= M_EXT; 45164837Sdwmalone MEXT_ADD_REF(m); 45215689Swollman } else { 45372750Sluigi n->m_data = n->m_pktdat + (m->m_data - m->m_pktdat ); 45415689Swollman bcopy(mtod(m, char *), mtod(n, char *), n->m_len); 45515689Swollman } 45615689Swollman 45715689Swollman m = m->m_next; 45815689Swollman while (m) { 45915689Swollman MGET(o, how, m->m_type); 46072356Sbmilekic if (o == NULL) 46115689Swollman goto nospace; 46215689Swollman 46315689Swollman n->m_next = o; 46415689Swollman n = n->m_next; 46515689Swollman 46615689Swollman n->m_len = m->m_len; 46715689Swollman if (m->m_flags & M_EXT) { 46815689Swollman n->m_data = m->m_data; 46915689Swollman n->m_ext = m->m_ext; 47015689Swollman n->m_flags |= M_EXT; 47164837Sdwmalone MEXT_ADD_REF(m); 47215689Swollman } else { 47315689Swollman bcopy(mtod(m, char *), mtod(n, char *), n->m_len); 47415689Swollman } 47515689Swollman 47615689Swollman m = m->m_next; 47715689Swollman } 47815689Swollman return top; 47915689Swollmannospace: 48015689Swollman m_freem(top); 48178592Sbmilekic mbstat.m_mcfail++; /* XXX: No consistency. */ 48272356Sbmilekic return (NULL); 48315689Swollman} 48415689Swollman 48515689Swollman/* 4861541Srgrimes * Copy data from an mbuf chain starting "off" bytes from the beginning, 4871541Srgrimes * continuing for "len" bytes, into the indicated buffer. 4881541Srgrimes */ 4891549Srgrimesvoid 49081907Sjulianm_copydata(const struct mbuf *m, int off, int len, caddr_t cp) 4911541Srgrimes{ 492103569Sbmilekic u_int count; 4931541Srgrimes 49452201Salfred KASSERT(off >= 0, ("m_copydata, negative off %d", off)); 49552201Salfred KASSERT(len >= 0, ("m_copydata, negative len %d", len)); 4961541Srgrimes while (off > 0) { 49752201Salfred KASSERT(m != NULL, ("m_copydata, offset > size of mbuf chain")); 4981541Srgrimes if (off < m->m_len) 4991541Srgrimes break; 5001541Srgrimes off -= m->m_len; 5011541Srgrimes m = m->m_next; 5021541Srgrimes } 5031541Srgrimes while (len > 0) { 50452201Salfred KASSERT(m != NULL, ("m_copydata, length > size of mbuf chain")); 5051541Srgrimes count = min(m->m_len - off, len); 5061541Srgrimes bcopy(mtod(m, caddr_t) + off, cp, count); 5071541Srgrimes len -= count; 5081541Srgrimes cp += count; 5091541Srgrimes off = 0; 5101541Srgrimes m = m->m_next; 5111541Srgrimes } 5121541Srgrimes} 5131541Srgrimes 5141541Srgrimes/* 51554002Sarchie * Copy a packet header mbuf chain into a completely new chain, including 51654002Sarchie * copying any mbuf clusters. Use this instead of m_copypacket() when 51754002Sarchie * you need a writable copy of an mbuf chain. 51854002Sarchie */ 51954002Sarchiestruct mbuf * 52072356Sbmilekicm_dup(struct mbuf *m, int how) 52154002Sarchie{ 52254002Sarchie struct mbuf **p, *top = NULL; 52354002Sarchie int remain, moff, nsize; 52454002Sarchie 52554002Sarchie /* Sanity check */ 52654002Sarchie if (m == NULL) 52772356Sbmilekic return (NULL); 528113255Sdes M_ASSERTPKTHDR(m); 52954002Sarchie 53054002Sarchie /* While there's more data, get a new mbuf, tack it on, and fill it */ 53154002Sarchie remain = m->m_pkthdr.len; 53254002Sarchie moff = 0; 53354002Sarchie p = ⊤ 53454002Sarchie while (remain > 0 || top == NULL) { /* allow m->m_pkthdr.len == 0 */ 53554002Sarchie struct mbuf *n; 53654002Sarchie 53754002Sarchie /* Get the next new mbuf */ 538129906Sbmilekic if (remain >= MINCLSIZE) { 539129906Sbmilekic n = m_getcl(how, m->m_type, 0); 540129906Sbmilekic nsize = MCLBYTES; 541129906Sbmilekic } else { 542129906Sbmilekic n = m_get(how, m->m_type); 543129906Sbmilekic nsize = MLEN; 544129906Sbmilekic } 54554002Sarchie if (n == NULL) 54654002Sarchie goto nospace; 547129906Sbmilekic 548129906Sbmilekic if (top == NULL) { /* First one, must be PKTHDR */ 549129906Sbmilekic if (!m_dup_pkthdr(n, m, how)) { 550129906Sbmilekic m_free(n); 551108466Ssam goto nospace; 552129906Sbmilekic } 55354002Sarchie nsize = MHLEN; 55454002Sarchie } 55554002Sarchie n->m_len = 0; 55654002Sarchie 55754002Sarchie /* Link it into the new chain */ 55854002Sarchie *p = n; 55954002Sarchie p = &n->m_next; 56054002Sarchie 56154002Sarchie /* Copy data from original mbuf(s) into new mbuf */ 56254002Sarchie while (n->m_len < nsize && m != NULL) { 56354002Sarchie int chunk = min(nsize - n->m_len, m->m_len - moff); 56454002Sarchie 56554002Sarchie bcopy(m->m_data + moff, n->m_data + n->m_len, chunk); 56654002Sarchie moff += chunk; 56754002Sarchie n->m_len += chunk; 56854002Sarchie remain -= chunk; 56954002Sarchie if (moff == m->m_len) { 57054002Sarchie m = m->m_next; 57154002Sarchie moff = 0; 57254002Sarchie } 57354002Sarchie } 57454002Sarchie 57554002Sarchie /* Check correct total mbuf length */ 57654002Sarchie KASSERT((remain > 0 && m != NULL) || (remain == 0 && m == NULL), 57787594Sobrien ("%s: bogus m_pkthdr.len", __func__)); 57854002Sarchie } 57954002Sarchie return (top); 58054002Sarchie 58154002Sarchienospace: 58254002Sarchie m_freem(top); 58378592Sbmilekic mbstat.m_mcfail++; /* XXX: No consistency. */ 58472356Sbmilekic return (NULL); 58554002Sarchie} 58654002Sarchie 58754002Sarchie/* 5881541Srgrimes * Concatenate mbuf chain n to m. 5891541Srgrimes * Both chains must be of the same type (e.g. MT_DATA). 5901541Srgrimes * Any m_pkthdr is not updated. 5911541Srgrimes */ 5921549Srgrimesvoid 59372356Sbmilekicm_cat(struct mbuf *m, struct mbuf *n) 5941541Srgrimes{ 5951541Srgrimes while (m->m_next) 5961541Srgrimes m = m->m_next; 5971541Srgrimes while (n) { 5981541Srgrimes if (m->m_flags & M_EXT || 5991541Srgrimes m->m_data + m->m_len + n->m_len >= &m->m_dat[MLEN]) { 6001541Srgrimes /* just join the two chains */ 6011541Srgrimes m->m_next = n; 6021541Srgrimes return; 6031541Srgrimes } 6041541Srgrimes /* splat the data from one into the other */ 6051541Srgrimes bcopy(mtod(n, caddr_t), mtod(m, caddr_t) + m->m_len, 6061541Srgrimes (u_int)n->m_len); 6071541Srgrimes m->m_len += n->m_len; 6081541Srgrimes n = m_free(n); 6091541Srgrimes } 6101541Srgrimes} 6111541Srgrimes 6121549Srgrimesvoid 61372356Sbmilekicm_adj(struct mbuf *mp, int req_len) 6141541Srgrimes{ 61572356Sbmilekic int len = req_len; 61672356Sbmilekic struct mbuf *m; 61772356Sbmilekic int count; 6181541Srgrimes 6191541Srgrimes if ((m = mp) == NULL) 6201541Srgrimes return; 6211541Srgrimes if (len >= 0) { 6221541Srgrimes /* 6231541Srgrimes * Trim from head. 6241541Srgrimes */ 6251541Srgrimes while (m != NULL && len > 0) { 6261541Srgrimes if (m->m_len <= len) { 6271541Srgrimes len -= m->m_len; 6281541Srgrimes m->m_len = 0; 6291541Srgrimes m = m->m_next; 6301541Srgrimes } else { 6311541Srgrimes m->m_len -= len; 6321541Srgrimes m->m_data += len; 6331541Srgrimes len = 0; 6341541Srgrimes } 6351541Srgrimes } 6361541Srgrimes m = mp; 6371541Srgrimes if (mp->m_flags & M_PKTHDR) 6381541Srgrimes m->m_pkthdr.len -= (req_len - len); 6391541Srgrimes } else { 6401541Srgrimes /* 6411541Srgrimes * Trim from tail. Scan the mbuf chain, 6421541Srgrimes * calculating its length and finding the last mbuf. 6431541Srgrimes * If the adjustment only affects this mbuf, then just 6441541Srgrimes * adjust and return. Otherwise, rescan and truncate 6451541Srgrimes * after the remaining size. 6461541Srgrimes */ 6471541Srgrimes len = -len; 6481541Srgrimes count = 0; 6491541Srgrimes for (;;) { 6501541Srgrimes count += m->m_len; 6511541Srgrimes if (m->m_next == (struct mbuf *)0) 6521541Srgrimes break; 6531541Srgrimes m = m->m_next; 6541541Srgrimes } 6551541Srgrimes if (m->m_len >= len) { 6561541Srgrimes m->m_len -= len; 6571541Srgrimes if (mp->m_flags & M_PKTHDR) 6581541Srgrimes mp->m_pkthdr.len -= len; 6591541Srgrimes return; 6601541Srgrimes } 6611541Srgrimes count -= len; 6621541Srgrimes if (count < 0) 6631541Srgrimes count = 0; 6641541Srgrimes /* 6651541Srgrimes * Correct length for chain is "count". 6661541Srgrimes * Find the mbuf with last data, adjust its length, 6671541Srgrimes * and toss data from remaining mbufs on chain. 6681541Srgrimes */ 6691541Srgrimes m = mp; 6701541Srgrimes if (m->m_flags & M_PKTHDR) 6711541Srgrimes m->m_pkthdr.len = count; 6721541Srgrimes for (; m; m = m->m_next) { 6731541Srgrimes if (m->m_len >= count) { 6741541Srgrimes m->m_len = count; 6751541Srgrimes break; 6761541Srgrimes } 6771541Srgrimes count -= m->m_len; 6781541Srgrimes } 6793308Sphk while (m->m_next) 6803308Sphk (m = m->m_next) ->m_len = 0; 6811541Srgrimes } 6821541Srgrimes} 6831541Srgrimes 6841541Srgrimes/* 6851541Srgrimes * Rearange an mbuf chain so that len bytes are contiguous 6861541Srgrimes * and in the data area of an mbuf (so that mtod and dtom 6871541Srgrimes * will work for a structure of size len). Returns the resulting 6881541Srgrimes * mbuf chain on success, frees it and returns null on failure. 6891541Srgrimes * If there is room, it will add up to max_protohdr-len extra bytes to the 6901541Srgrimes * contiguous region in an attempt to avoid being called next time. 6911541Srgrimes */ 6921541Srgrimesstruct mbuf * 69372356Sbmilekicm_pullup(struct mbuf *n, int len) 6941541Srgrimes{ 69572356Sbmilekic struct mbuf *m; 69672356Sbmilekic int count; 6971541Srgrimes int space; 6981541Srgrimes 6991541Srgrimes /* 7001541Srgrimes * If first mbuf has no cluster, and has room for len bytes 7011541Srgrimes * without shifting current data, pullup into it, 7021541Srgrimes * otherwise allocate a new mbuf to prepend to the chain. 7031541Srgrimes */ 7041541Srgrimes if ((n->m_flags & M_EXT) == 0 && 7051541Srgrimes n->m_data + len < &n->m_dat[MLEN] && n->m_next) { 7061541Srgrimes if (n->m_len >= len) 7071541Srgrimes return (n); 7081541Srgrimes m = n; 7091541Srgrimes n = n->m_next; 7101541Srgrimes len -= m->m_len; 7111541Srgrimes } else { 7121541Srgrimes if (len > MHLEN) 7131541Srgrimes goto bad; 714111119Simp MGET(m, M_DONTWAIT, n->m_type); 71572356Sbmilekic if (m == NULL) 7161541Srgrimes goto bad; 7171541Srgrimes m->m_len = 0; 718108466Ssam if (n->m_flags & M_PKTHDR) 719108466Ssam M_MOVE_PKTHDR(m, n); 7201541Srgrimes } 7211541Srgrimes space = &m->m_dat[MLEN] - (m->m_data + m->m_len); 7221541Srgrimes do { 7231541Srgrimes count = min(min(max(len, max_protohdr), space), n->m_len); 7241541Srgrimes bcopy(mtod(n, caddr_t), mtod(m, caddr_t) + m->m_len, 725103569Sbmilekic (u_int)count); 7261541Srgrimes len -= count; 7271541Srgrimes m->m_len += count; 7281541Srgrimes n->m_len -= count; 7291541Srgrimes space -= count; 7301541Srgrimes if (n->m_len) 7311541Srgrimes n->m_data += count; 7321541Srgrimes else 7331541Srgrimes n = m_free(n); 7341541Srgrimes } while (len > 0 && n); 7351541Srgrimes if (len > 0) { 7361541Srgrimes (void) m_free(m); 7371541Srgrimes goto bad; 7381541Srgrimes } 7391541Srgrimes m->m_next = n; 7401541Srgrimes return (m); 7411541Srgrimesbad: 7421541Srgrimes m_freem(n); 74378592Sbmilekic mbstat.m_mpfail++; /* XXX: No consistency. */ 74472356Sbmilekic return (NULL); 7451541Srgrimes} 7461541Srgrimes 7471541Srgrimes/* 7481541Srgrimes * Partition an mbuf chain in two pieces, returning the tail -- 7491541Srgrimes * all but the first len0 bytes. In case of failure, it returns NULL and 7501541Srgrimes * attempts to restore the chain to its original state. 75197681Sarchie * 75297681Sarchie * Note that the resulting mbufs might be read-only, because the new 75397681Sarchie * mbuf can end up sharing an mbuf cluster with the original mbuf if 75497681Sarchie * the "breaking point" happens to lie within a cluster mbuf. Use the 75597681Sarchie * M_WRITABLE() macro to check for this case. 7561541Srgrimes */ 7571541Srgrimesstruct mbuf * 75872356Sbmilekicm_split(struct mbuf *m0, int len0, int wait) 7591541Srgrimes{ 76072356Sbmilekic struct mbuf *m, *n; 761103569Sbmilekic u_int len = len0, remain; 7621541Srgrimes 7631541Srgrimes for (m = m0; m && len > m->m_len; m = m->m_next) 7641541Srgrimes len -= m->m_len; 76572356Sbmilekic if (m == NULL) 76672356Sbmilekic return (NULL); 7671541Srgrimes remain = m->m_len - len; 7681541Srgrimes if (m0->m_flags & M_PKTHDR) { 7691541Srgrimes MGETHDR(n, wait, m0->m_type); 77072356Sbmilekic if (n == NULL) 77172356Sbmilekic return (NULL); 7721541Srgrimes n->m_pkthdr.rcvif = m0->m_pkthdr.rcvif; 7731541Srgrimes n->m_pkthdr.len = m0->m_pkthdr.len - len0; 7741541Srgrimes m0->m_pkthdr.len = len0; 7751541Srgrimes if (m->m_flags & M_EXT) 7761541Srgrimes goto extpacket; 7771541Srgrimes if (remain > MHLEN) { 7781541Srgrimes /* m can't be the lead packet */ 7791541Srgrimes MH_ALIGN(n, 0); 7801541Srgrimes n->m_next = m_split(m, len, wait); 78172356Sbmilekic if (n->m_next == NULL) { 7821541Srgrimes (void) m_free(n); 78372356Sbmilekic return (NULL); 78494471Shsu } else { 78594471Shsu n->m_len = 0; 7861541Srgrimes return (n); 78794471Shsu } 7881541Srgrimes } else 7891541Srgrimes MH_ALIGN(n, remain); 7901541Srgrimes } else if (remain == 0) { 7911541Srgrimes n = m->m_next; 79272356Sbmilekic m->m_next = NULL; 7931541Srgrimes return (n); 7941541Srgrimes } else { 7951541Srgrimes MGET(n, wait, m->m_type); 79672356Sbmilekic if (n == NULL) 79772356Sbmilekic return (NULL); 7981541Srgrimes M_ALIGN(n, remain); 7991541Srgrimes } 8001541Srgrimesextpacket: 8011541Srgrimes if (m->m_flags & M_EXT) { 8021541Srgrimes n->m_flags |= M_EXT; 8031541Srgrimes n->m_ext = m->m_ext; 80464837Sdwmalone MEXT_ADD_REF(m); 8051541Srgrimes n->m_data = m->m_data + len; 8061541Srgrimes } else { 8071541Srgrimes bcopy(mtod(m, caddr_t) + len, mtod(n, caddr_t), remain); 8081541Srgrimes } 8091541Srgrimes n->m_len = remain; 8101541Srgrimes m->m_len = len; 8111541Srgrimes n->m_next = m->m_next; 81272356Sbmilekic m->m_next = NULL; 8131541Srgrimes return (n); 8141541Srgrimes} 8151541Srgrimes/* 8161541Srgrimes * Routine to copy from device local memory into mbufs. 81778508Sbmilekic * Note that `off' argument is offset into first mbuf of target chain from 81878508Sbmilekic * which to begin copying the data to. 8191541Srgrimes */ 8201541Srgrimesstruct mbuf * 82178508Sbmilekicm_devget(char *buf, int totlen, int off, struct ifnet *ifp, 82272356Sbmilekic void (*copy)(char *from, caddr_t to, u_int len)) 8231541Srgrimes{ 82472356Sbmilekic struct mbuf *m; 825129906Sbmilekic struct mbuf *top = NULL, **mp = ⊤ 82678508Sbmilekic int len; 8271541Srgrimes 82878508Sbmilekic if (off < 0 || off > MHLEN) 82978508Sbmilekic return (NULL); 83078508Sbmilekic 831129906Sbmilekic while (totlen > 0) { 832129906Sbmilekic if (top == NULL) { /* First one, must be PKTHDR */ 833129906Sbmilekic if (totlen + off >= MINCLSIZE) { 834129906Sbmilekic m = m_getcl(M_DONTWAIT, MT_DATA, M_PKTHDR); 835129906Sbmilekic len = MCLBYTES; 836129906Sbmilekic } else { 837129906Sbmilekic m = m_gethdr(M_DONTWAIT, MT_DATA); 838129906Sbmilekic len = MHLEN; 8391541Srgrimes 840129906Sbmilekic /* Place initial small packet/header at end of mbuf */ 841129906Sbmilekic if (m && totlen + off + max_linkhdr <= MLEN) { 842129906Sbmilekic m->m_data += max_linkhdr; 843129906Sbmilekic len -= max_linkhdr; 844129906Sbmilekic } 845129906Sbmilekic } 846129906Sbmilekic if (m == NULL) 847129906Sbmilekic return NULL; 848129906Sbmilekic m->m_pkthdr.rcvif = ifp; 849129906Sbmilekic m->m_pkthdr.len = totlen; 850129906Sbmilekic } else { 851129906Sbmilekic if (totlen + off >= MINCLSIZE) { 852129906Sbmilekic m = m_getcl(M_DONTWAIT, MT_DATA, 0); 853129906Sbmilekic len = MCLBYTES; 854129906Sbmilekic } else { 855129906Sbmilekic m = m_get(M_DONTWAIT, MT_DATA); 856129906Sbmilekic len = MLEN; 857129906Sbmilekic } 85872356Sbmilekic if (m == NULL) { 8591541Srgrimes m_freem(top); 860129906Sbmilekic return NULL; 8611541Srgrimes } 8621541Srgrimes } 86378508Sbmilekic if (off) { 86478508Sbmilekic m->m_data += off; 86578508Sbmilekic len -= off; 86678508Sbmilekic off = 0; 86778508Sbmilekic } 86878508Sbmilekic m->m_len = len = min(totlen, len); 8691541Srgrimes if (copy) 870103569Sbmilekic copy(buf, mtod(m, caddr_t), (u_int)len); 8711541Srgrimes else 872103569Sbmilekic bcopy(buf, mtod(m, caddr_t), (u_int)len); 87378508Sbmilekic buf += len; 8741541Srgrimes *mp = m; 8751541Srgrimes mp = &m->m_next; 8761541Srgrimes totlen -= len; 8771541Srgrimes } 8781541Srgrimes return (top); 8791541Srgrimes} 8803352Sphk 8813352Sphk/* 8823352Sphk * Copy data from a buffer back into the indicated mbuf chain, 8833352Sphk * starting "off" bytes from the beginning, extending the mbuf 8843352Sphk * chain if necessary. 8853352Sphk */ 8863352Sphkvoid 887128402Sluigim_copyback(struct mbuf *m0, int off, int len, c_caddr_t cp) 8883352Sphk{ 88972356Sbmilekic int mlen; 89072356Sbmilekic struct mbuf *m = m0, *n; 8913352Sphk int totlen = 0; 8923352Sphk 89372356Sbmilekic if (m0 == NULL) 8943352Sphk return; 8953352Sphk while (off > (mlen = m->m_len)) { 8963352Sphk off -= mlen; 8973352Sphk totlen += mlen; 89872356Sbmilekic if (m->m_next == NULL) { 899129906Sbmilekic n = m_get(M_DONTWAIT, m->m_type); 90072356Sbmilekic if (n == NULL) 9013352Sphk goto out; 902129906Sbmilekic bzero(mtod(n, caddr_t), MLEN); 9033352Sphk n->m_len = min(MLEN, len + off); 9043352Sphk m->m_next = n; 9053352Sphk } 9063352Sphk m = m->m_next; 9073352Sphk } 9083352Sphk while (len > 0) { 9093352Sphk mlen = min (m->m_len - off, len); 910103569Sbmilekic bcopy(cp, off + mtod(m, caddr_t), (u_int)mlen); 9113352Sphk cp += mlen; 9123352Sphk len -= mlen; 9133352Sphk mlen += off; 9143352Sphk off = 0; 9153352Sphk totlen += mlen; 9163352Sphk if (len == 0) 9173352Sphk break; 91872356Sbmilekic if (m->m_next == NULL) { 919111119Simp n = m_get(M_DONTWAIT, m->m_type); 92072356Sbmilekic if (n == NULL) 9213352Sphk break; 9223352Sphk n->m_len = min(MLEN, len); 9233352Sphk m->m_next = n; 9243352Sphk } 9253352Sphk m = m->m_next; 9263352Sphk } 9273352Sphkout: if (((m = m0)->m_flags & M_PKTHDR) && (m->m_pkthdr.len < totlen)) 9283352Sphk m->m_pkthdr.len = totlen; 9293352Sphk} 93052756Sphk 931123557Sbms/* 932123557Sbms * Apply function f to the data in an mbuf chain starting "off" bytes from 933123557Sbms * the beginning, continuing for "len" bytes. 934123557Sbms */ 935123557Sbmsint 936123557Sbmsm_apply(struct mbuf *m, int off, int len, 937123564Sbms int (*f)(void *, void *, u_int), void *arg) 938123557Sbms{ 939123564Sbms u_int count; 940123557Sbms int rval; 941123557Sbms 942123557Sbms KASSERT(off >= 0, ("m_apply, negative off %d", off)); 943123557Sbms KASSERT(len >= 0, ("m_apply, negative len %d", len)); 944123557Sbms while (off > 0) { 945123557Sbms KASSERT(m != NULL, ("m_apply, offset > size of mbuf chain")); 946123557Sbms if (off < m->m_len) 947123557Sbms break; 948123557Sbms off -= m->m_len; 949123557Sbms m = m->m_next; 950123557Sbms } 951123557Sbms while (len > 0) { 952123557Sbms KASSERT(m != NULL, ("m_apply, offset > size of mbuf chain")); 953123557Sbms count = min(m->m_len - off, len); 954123557Sbms rval = (*f)(arg, mtod(m, caddr_t) + off, count); 955123557Sbms if (rval) 956123557Sbms return (rval); 957123557Sbms len -= count; 958123557Sbms off = 0; 959123557Sbms m = m->m_next; 960123557Sbms } 961123557Sbms return (0); 962123557Sbms} 963123557Sbms 964123557Sbms/* 965123557Sbms * Return a pointer to mbuf/offset of location in mbuf chain. 966123557Sbms */ 967123557Sbmsstruct mbuf * 968123557Sbmsm_getptr(struct mbuf *m, int loc, int *off) 969123557Sbms{ 970123557Sbms 971123557Sbms while (loc >= 0) { 972123564Sbms /* Normal end of search. */ 973123557Sbms if (m->m_len > loc) { 974123557Sbms *off = loc; 975123557Sbms return (m); 976123557Sbms } else { 977123557Sbms loc -= m->m_len; 978123557Sbms if (m->m_next == NULL) { 979123557Sbms if (loc == 0) { 980123564Sbms /* Point at the end of valid data. */ 981123557Sbms *off = m->m_len; 982123557Sbms return (m); 983123564Sbms } 984123564Sbms return (NULL); 985123564Sbms } 986123564Sbms m = m->m_next; 987123557Sbms } 988123557Sbms } 989123557Sbms return (NULL); 990123557Sbms} 991123557Sbms 99252756Sphkvoid 99352756Sphkm_print(const struct mbuf *m) 99452756Sphk{ 99552756Sphk int len; 99654906Seivind const struct mbuf *m2; 99752756Sphk 99852756Sphk len = m->m_pkthdr.len; 99952756Sphk m2 = m; 100052756Sphk while (len) { 100152756Sphk printf("%p %*D\n", m2, m2->m_len, (u_char *)m2->m_data, "-"); 100252756Sphk len -= m2->m_len; 100352756Sphk m2 = m2->m_next; 100452756Sphk } 100552756Sphk return; 100652756Sphk} 1007103540Sphk 1008103569Sbmilekicu_int 1009103540Sphkm_fixhdr(struct mbuf *m0) 1010103540Sphk{ 1011103569Sbmilekic u_int len; 1012103540Sphk 1013103544Sphk len = m_length(m0, NULL); 1014103544Sphk m0->m_pkthdr.len = len; 1015103544Sphk return (len); 1016103544Sphk} 1017103544Sphk 1018103569Sbmilekicu_int 1019103544Sphkm_length(struct mbuf *m0, struct mbuf **last) 1020103544Sphk{ 1021103544Sphk struct mbuf *m; 1022103569Sbmilekic u_int len; 1023103544Sphk 1024103544Sphk len = 0; 1025103544Sphk for (m = m0; m != NULL; m = m->m_next) { 1026103540Sphk len += m->m_len; 1027103544Sphk if (m->m_next == NULL) 1028103544Sphk break; 1029103540Sphk } 1030103544Sphk if (last != NULL) 1031103544Sphk *last = m; 1032103544Sphk return (len); 1033103540Sphk} 1034112777Ssilby 1035112777Ssilby/* 1036112777Ssilby * Defragment a mbuf chain, returning the shortest possible 1037112777Ssilby * chain of mbufs and clusters. If allocation fails and 1038112777Ssilby * this cannot be completed, NULL will be returned, but 1039112777Ssilby * the passed in chain will be unchanged. Upon success, 1040112777Ssilby * the original chain will be freed, and the new chain 1041112777Ssilby * will be returned. 1042112777Ssilby * 1043112777Ssilby * If a non-packet header is passed in, the original 1044112777Ssilby * mbuf (chain?) will be returned unharmed. 1045112777Ssilby */ 1046112777Ssilbystruct mbuf * 1047112777Ssilbym_defrag(struct mbuf *m0, int how) 1048112777Ssilby{ 1049125472Ssilby struct mbuf *m_new = NULL, *m_final = NULL; 1050125472Ssilby int progress = 0, length; 1051112777Ssilby 1052112777Ssilby if (!(m0->m_flags & M_PKTHDR)) 1053112777Ssilby return (m0); 1054112777Ssilby 1055117770Ssilby m_fixhdr(m0); /* Needed sanity check */ 1056117770Ssilby 1057113490Ssilby#ifdef MBUF_STRESS_TEST 1058113490Ssilby if (m_defragrandomfailures) { 1059113490Ssilby int temp = arc4random() & 0xff; 1060113490Ssilby if (temp == 0xba) 1061113490Ssilby goto nospace; 1062113490Ssilby } 1063113490Ssilby#endif 1064112777Ssilby 1065112777Ssilby if (m0->m_pkthdr.len > MHLEN) 1066112777Ssilby m_final = m_getcl(how, MT_DATA, M_PKTHDR); 1067112777Ssilby else 1068112777Ssilby m_final = m_gethdr(how, MT_DATA); 1069112777Ssilby 1070112777Ssilby if (m_final == NULL) 1071112777Ssilby goto nospace; 1072112777Ssilby 1073123740Speter if (m_dup_pkthdr(m_final, m0, how) == 0) 1074112777Ssilby goto nospace; 1075112777Ssilby 1076112777Ssilby m_new = m_final; 1077112777Ssilby 1078112777Ssilby while (progress < m0->m_pkthdr.len) { 1079112777Ssilby length = m0->m_pkthdr.len - progress; 1080112777Ssilby if (length > MCLBYTES) 1081112777Ssilby length = MCLBYTES; 1082112777Ssilby 1083112777Ssilby if (m_new == NULL) { 1084112777Ssilby if (length > MLEN) 1085112777Ssilby m_new = m_getcl(how, MT_DATA, 0); 1086112777Ssilby else 1087112777Ssilby m_new = m_get(how, MT_DATA); 1088112777Ssilby if (m_new == NULL) 1089112777Ssilby goto nospace; 1090112777Ssilby } 1091112777Ssilby 1092112777Ssilby m_copydata(m0, progress, length, mtod(m_new, caddr_t)); 1093112777Ssilby progress += length; 1094112777Ssilby m_new->m_len = length; 1095112777Ssilby if (m_new != m_final) 1096112777Ssilby m_cat(m_final, m_new); 1097112777Ssilby m_new = NULL; 1098112777Ssilby } 1099116455Ssilby#ifdef MBUF_STRESS_TEST 1100112777Ssilby if (m0->m_next == NULL) 1101112777Ssilby m_defraguseless++; 1102116455Ssilby#endif 1103112777Ssilby m_freem(m0); 1104112777Ssilby m0 = m_final; 1105116455Ssilby#ifdef MBUF_STRESS_TEST 1106112777Ssilby m_defragpackets++; 1107112777Ssilby m_defragbytes += m0->m_pkthdr.len; 1108116455Ssilby#endif 1109112777Ssilby return (m0); 1110112777Ssilbynospace: 1111116455Ssilby#ifdef MBUF_STRESS_TEST 1112112777Ssilby m_defragfailure++; 1113116455Ssilby#endif 1114112777Ssilby if (m_new) 1115112777Ssilby m_free(m_new); 1116112777Ssilby if (m_final) 1117112777Ssilby m_freem(m_final); 1118112777Ssilby return (NULL); 1119112777Ssilby} 1120119644Ssilby 1121119644Ssilby#ifdef MBUF_STRESS_TEST 1122119644Ssilby 1123119644Ssilby/* 1124119644Ssilby * Fragment an mbuf chain. There's no reason you'd ever want to do 1125119644Ssilby * this in normal usage, but it's great for stress testing various 1126119644Ssilby * mbuf consumers. 1127119644Ssilby * 1128119644Ssilby * If fragmentation is not possible, the original chain will be 1129119644Ssilby * returned. 1130119644Ssilby * 1131119644Ssilby * Possible length values: 1132119644Ssilby * 0 no fragmentation will occur 1133119644Ssilby * > 0 each fragment will be of the specified length 1134119644Ssilby * -1 each fragment will be the same random value in length 1135119644Ssilby * -2 each fragment's length will be entirely random 1136119644Ssilby * (Random values range from 1 to 256) 1137119644Ssilby */ 1138119644Ssilbystruct mbuf * 1139119644Ssilbym_fragment(struct mbuf *m0, int how, int length) 1140119644Ssilby{ 1141125472Ssilby struct mbuf *m_new = NULL, *m_final = NULL; 1142125472Ssilby int progress = 0; 1143119644Ssilby 1144119644Ssilby if (!(m0->m_flags & M_PKTHDR)) 1145119644Ssilby return (m0); 1146119644Ssilby 1147119644Ssilby if ((length == 0) || (length < -2)) 1148119644Ssilby return (m0); 1149119644Ssilby 1150119644Ssilby m_fixhdr(m0); /* Needed sanity check */ 1151119644Ssilby 1152119644Ssilby m_final = m_getcl(how, MT_DATA, M_PKTHDR); 1153119644Ssilby 1154119644Ssilby if (m_final == NULL) 1155119644Ssilby goto nospace; 1156119644Ssilby 1157123823Ssilby if (m_dup_pkthdr(m_final, m0, how) == 0) 1158119644Ssilby goto nospace; 1159119644Ssilby 1160119644Ssilby m_new = m_final; 1161119644Ssilby 1162119644Ssilby if (length == -1) 1163119644Ssilby length = 1 + (arc4random() & 255); 1164119644Ssilby 1165119644Ssilby while (progress < m0->m_pkthdr.len) { 1166119644Ssilby int fraglen; 1167119644Ssilby 1168119644Ssilby if (length > 0) 1169119644Ssilby fraglen = length; 1170119644Ssilby else 1171119644Ssilby fraglen = 1 + (arc4random() & 255); 1172119644Ssilby if (fraglen > m0->m_pkthdr.len - progress) 1173119644Ssilby fraglen = m0->m_pkthdr.len - progress; 1174119644Ssilby 1175119644Ssilby if (fraglen > MCLBYTES) 1176119644Ssilby fraglen = MCLBYTES; 1177119644Ssilby 1178119644Ssilby if (m_new == NULL) { 1179119644Ssilby m_new = m_getcl(how, MT_DATA, 0); 1180119644Ssilby if (m_new == NULL) 1181119644Ssilby goto nospace; 1182119644Ssilby } 1183119644Ssilby 1184119644Ssilby m_copydata(m0, progress, fraglen, mtod(m_new, caddr_t)); 1185119644Ssilby progress += fraglen; 1186119644Ssilby m_new->m_len = fraglen; 1187119644Ssilby if (m_new != m_final) 1188119644Ssilby m_cat(m_final, m_new); 1189119644Ssilby m_new = NULL; 1190119644Ssilby } 1191119644Ssilby m_freem(m0); 1192119644Ssilby m0 = m_final; 1193119644Ssilby return (m0); 1194119644Ssilbynospace: 1195119644Ssilby if (m_new) 1196119644Ssilby m_free(m_new); 1197119644Ssilby if (m_final) 1198119644Ssilby m_freem(m_final); 1199119644Ssilby /* Return the original chain on failure */ 1200119644Ssilby return (m0); 1201119644Ssilby} 1202119644Ssilby 1203119644Ssilby#endif 1204125296Ssilby 1205125296Ssilbystruct mbuf * 1206125296Ssilbym_uiotombuf(struct uio *uio, int how, int len) 1207125296Ssilby{ 1208125472Ssilby struct mbuf *m_new = NULL, *m_final = NULL; 1209125472Ssilby int progress = 0, error = 0, length, total; 1210125296Ssilby 1211125296Ssilby if (len > 0) 1212125296Ssilby total = min(uio->uio_resid, len); 1213125296Ssilby else 1214125296Ssilby total = uio->uio_resid; 1215125296Ssilby if (total > MHLEN) 1216125296Ssilby m_final = m_getcl(how, MT_DATA, M_PKTHDR); 1217125296Ssilby else 1218125296Ssilby m_final = m_gethdr(how, MT_DATA); 1219125296Ssilby if (m_final == NULL) 1220125296Ssilby goto nospace; 1221125296Ssilby m_new = m_final; 1222125296Ssilby while (progress < total) { 1223125296Ssilby length = total - progress; 1224125296Ssilby if (length > MCLBYTES) 1225125296Ssilby length = MCLBYTES; 1226125296Ssilby if (m_new == NULL) { 1227125296Ssilby if (length > MLEN) 1228125296Ssilby m_new = m_getcl(how, MT_DATA, 0); 1229125296Ssilby else 1230125296Ssilby m_new = m_get(how, MT_DATA); 1231125296Ssilby if (m_new == NULL) 1232125296Ssilby goto nospace; 1233125296Ssilby } 1234125296Ssilby error = uiomove(mtod(m_new, void *), length, uio); 1235125296Ssilby if (error) 1236125296Ssilby goto nospace; 1237125296Ssilby progress += length; 1238125296Ssilby m_new->m_len = length; 1239125296Ssilby if (m_new != m_final) 1240125296Ssilby m_cat(m_final, m_new); 1241125296Ssilby m_new = NULL; 1242125296Ssilby } 1243125296Ssilby m_fixhdr(m_final); 1244125296Ssilby return (m_final); 1245125296Ssilbynospace: 1246125296Ssilby if (m_new) 1247125296Ssilby m_free(m_new); 1248125296Ssilby if (m_final) 1249125296Ssilby m_freem(m_final); 1250125296Ssilby return (NULL); 1251125296Ssilby} 1252