uipc_mbuf.c revision 149643
1139804Simp/*- 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 149643 2005-08-30 20:07:49Z andre $"); 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 */ 91141616Sphkstatic MALLOC_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) 202143188Salc ref_cnt = __DEVOLATILE(u_int *, 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; 225141668Sbmilekic int dofree; 226129906Sbmilekic 227141668Sbmilekic /* Account for lazy ref count assign. */ 228141668Sbmilekic if (m->m_ext.ref_cnt == NULL) 229141668Sbmilekic dofree = 1; 230141668Sbmilekic else 231141668Sbmilekic dofree = 0; 232141668Sbmilekic 233130289Sbmilekic /* 234130289Sbmilekic * This is tricky. We need to make sure to decrement the 235130289Sbmilekic * refcount in a safe way but to also clean up if we're the 236130289Sbmilekic * last reference. This method seems to do it without race. 237130289Sbmilekic */ 238141668Sbmilekic while (dofree == 0) { 239143188Salc cnt = *(m->m_ext.ref_cnt); 240130289Sbmilekic if (atomic_cmpset_int(m->m_ext.ref_cnt, cnt, cnt - 1)) { 241141668Sbmilekic if (cnt == 1) 242141668Sbmilekic dofree = 1; 243130289Sbmilekic break; 244129906Sbmilekic } 245141668Sbmilekic } 246141668Sbmilekic 247141668Sbmilekic if (dofree) { 248141668Sbmilekic /* 249141668Sbmilekic * Do the free, should be safe. 250141668Sbmilekic */ 251141668Sbmilekic if (m->m_ext.ext_type == EXT_PACKET) { 252141668Sbmilekic uma_zfree(zone_pack, m); 253141668Sbmilekic return; 254141668Sbmilekic } else if (m->m_ext.ext_type == EXT_CLUSTER) { 255141668Sbmilekic uma_zfree(zone_clust, m->m_ext.ext_buf); 256141668Sbmilekic m->m_ext.ext_buf = NULL; 257141668Sbmilekic } else { 258141668Sbmilekic (*(m->m_ext.ext_free))(m->m_ext.ext_buf, 259141668Sbmilekic m->m_ext.ext_args); 260141668Sbmilekic if (m->m_ext.ext_type != EXT_EXTREF) { 261141668Sbmilekic if (m->m_ext.ref_cnt != NULL) 262143188Salc free(__DEVOLATILE(u_int *, 263143188Salc m->m_ext.ref_cnt), M_MBUF); 264141668Sbmilekic m->m_ext.ref_cnt = NULL; 265141668Sbmilekic } 266141668Sbmilekic m->m_ext.ext_buf = NULL; 267141668Sbmilekic } 268141668Sbmilekic } 269130357Sbmilekic uma_zfree(zone_mbuf, m); 270129906Sbmilekic} 271129906Sbmilekic 272129906Sbmilekic/* 273149598Sandre * Clean up mbuf (chain) from any tags and packet headers. 274149598Sandre */ 275149598Sandrevoid 276149643Sandrem_demote(struct mbuf *m0) 277149598Sandre{ 278149598Sandre struct mbuf *m; 279149598Sandre 280149598Sandre for (m = all ? m0 : m0->m_next; m != NULL; m = m->m_next) { 281149598Sandre if (m->m_flags & M_PKTHDR) { 282149598Sandre m_tag_delete_chain(m, NULL); 283149598Sandre m->m_flags &= ~M_PKTHDR; 284149598Sandre bzero(&m->m_pkthdr, sizeof(struct pkthdr)); 285149598Sandre } 286149643Sandre if (m->m_type == MT_HEADER) 287149598Sandre m->m_type = MT_DATA; 288149643Sandre if (m != m0 && m->m_nextpkt != NULL) 289149598Sandre m->m_nextpkt = NULL; 290149598Sandre m->m_flags = m->m_flags & (M_EXT|M_EOR|M_RDONLY|M_FREELIST); 291149598Sandre } 292149598Sandre} 293149598Sandre 294149598Sandre/* 295149599Sandre * Sanity checks on mbuf (chain). 296149599Sandre * Returns 0 bad, 1 good, panic worse. 297149599Sandre * sanitize, 0 run M_SANITY_ACTION, 1 garble things so they blow up later. 298149599Sandre */ 299149599Sandreint 300149599Sandrem_sanity(struct mbuf *m0, int sanitize) 301149599Sandre{ 302149599Sandre struct mbuf *m; 303149599Sandre caddr_t a, b; 304149599Sandre int pktlen = 0; 305149599Sandre 306149599Sandre#define M_SANITY_ACTION(s) return (0) 307149599Sandre/* #define M_SANITY_ACTION(s) panic("mbuf %p: " s, m) */ 308149599Sandre 309149599Sandre m = m0; 310149599Sandre while (m) { 311149599Sandre /* 312149599Sandre * Basic pointer checks. If any of these fails then some 313149599Sandre * unrelated kernel memory before or after us is trashed. 314149599Sandre * No way to recover from that. 315149599Sandre */ 316149599Sandre a = (m->m_flags & M_EXT ? m->m_ext.ext_buf : 317149599Sandre (m->m_flags & M_PKTHDR ? (caddr_t)(&m->m_pktdat) : 318149599Sandre (caddr_t)(&m->m_dat)) ); 319149599Sandre b = (caddr_t)(a + (m->m_flags & M_EXT ? m->m_ext.ext_size : 320149599Sandre (m->m_flags & M_PKTHDR ? MHLEN : MLEN))); 321149599Sandre if ((caddr_t)m->m_data < a) 322149599Sandre M_SANITY_ACTION("m_data outside mbuf data range left"); 323149599Sandre if ((caddr_t)m->m_data > b) 324149599Sandre M_SANITY_ACTION("m_data outside mbuf data range right"); 325149599Sandre if ((caddr_t)m->m_data + m->m_len > b) 326149599Sandre M_SANITY_ACTION("m_data + m_len exeeds mbuf space"); 327149599Sandre if (m->m_flags & M_PKTHDR && m->m_pkthdr.header) { 328149599Sandre if ((caddr_t)m->m_pkthdr.header < a || 329149599Sandre (caddr_t)m->m_pkthdr.header > b) 330149599Sandre M_SANITY_ACTION("m_pkthdr.header outside mbuf data range"); 331149599Sandre } 332149599Sandre 333149599Sandre /* m->m_nextpkt may only be set on first mbuf in chain. */ 334149599Sandre if (m != m0 && m->m_nextpkt) { 335149599Sandre if (sanitize) { 336149599Sandre m_freem(m->m_nextpkt); 337149599Sandre m->m_nextpkt = (struct mbuf *)0xDEADC0DE; 338149599Sandre } else 339149599Sandre M_SANITY_ACTION("m->m_nextpkt on in-chain mbuf"); 340149599Sandre } 341149599Sandre 342149599Sandre /* correct type correlations. */ 343149599Sandre if (m->m_type == MT_HEADER && !(m->m_flags & M_PKTHDR)) { 344149599Sandre if (sanitize) 345149599Sandre m->m_type = MT_DATA; 346149599Sandre else 347149599Sandre M_SANITY_ACTION("MT_HEADER set but not M_PKTHDR"); 348149599Sandre } 349149599Sandre 350149599Sandre /* packet length (not mbuf length!) calculation */ 351149599Sandre if (m0->m_flags & M_PKTHDR) 352149599Sandre pktlen += m->m_len; 353149599Sandre 354149599Sandre /* m_tags may only be attached to first mbuf in chain. */ 355149599Sandre if (m != m0 && m->m_flags & M_PKTHDR && 356149599Sandre !SLIST_EMPTY(&m->m_pkthdr.tags)) { 357149599Sandre if (sanitize) { 358149599Sandre m_tag_delete_chain(m, NULL); 359149599Sandre /* put in 0xDEADC0DE perhaps? */ 360149599Sandre } 361149599Sandre else 362149599Sandre M_SANITY_ACTION("m_tags on in-chain mbuf"); 363149599Sandre } 364149599Sandre 365149599Sandre /* M_PKTHDR may only be set on first mbuf in chain */ 366149599Sandre if (m != m0 && m->m_flags & M_PKTHDR) { 367149599Sandre if (sanitize) { 368149599Sandre bzero(&m->m_pkthdr, sizeof(m->m_pkthdr)); 369149599Sandre m->m_flags &= ~M_PKTHDR; 370149599Sandre /* put in 0xDEADCODE and leave hdr flag in */ 371149599Sandre } else 372149599Sandre M_SANITY_ACTION("M_PKTHDR on in-chain mbuf"); 373149599Sandre } 374149599Sandre 375149599Sandre m = m->m_next; 376149599Sandre } 377149599Sandre if (pktlen && pktlen != m0->m_pkthdr.len) { 378149599Sandre if (sanitize) 379149599Sandre m0->m_pkthdr.len = 0; 380149599Sandre else 381149599Sandre M_SANITY_ACTION("m_pkthdr.len != mbuf chain length"); 382149599Sandre } 383149599Sandre#undef M_SANITY_ACTION 384149599Sandre 385149599Sandre return 1; 386149599Sandre} 387149599Sandre 388149599Sandre 389149599Sandre/* 390108466Ssam * "Move" mbuf pkthdr from "from" to "to". 391100960Srwatson * "from" must have M_PKTHDR set, and "to" must be empty. 392100960Srwatson */ 393100960Srwatsonvoid 394108466Ssamm_move_pkthdr(struct mbuf *to, struct mbuf *from) 395100960Srwatson{ 396100960Srwatson 397100960Srwatson#if 0 398108466Ssam /* see below for why these are not enabled */ 399113255Sdes M_ASSERTPKTHDR(to); 400113487Srwatson /* Note: with MAC, this may not be a good assertion. */ 401108466Ssam KASSERT(SLIST_EMPTY(&to->m_pkthdr.tags), 402108466Ssam ("m_move_pkthdr: to has tags")); 403100960Srwatson#endif 404101007Srwatson#ifdef MAC 405113487Srwatson /* 406113487Srwatson * XXXMAC: It could be this should also occur for non-MAC? 407113487Srwatson */ 408101007Srwatson if (to->m_flags & M_PKTHDR) 409113487Srwatson m_tag_delete_chain(to, NULL); 410101007Srwatson#endif 411143302Ssam to->m_flags = (from->m_flags & M_COPYFLAGS) | (to->m_flags & M_EXT); 412143302Ssam if ((to->m_flags & M_EXT) == 0) 413143302Ssam to->m_data = to->m_pktdat; 414108466Ssam to->m_pkthdr = from->m_pkthdr; /* especially tags */ 415108466Ssam SLIST_INIT(&from->m_pkthdr.tags); /* purge tags from src */ 416108466Ssam from->m_flags &= ~M_PKTHDR; 417108466Ssam} 418108466Ssam 419108466Ssam/* 420108466Ssam * Duplicate "from"'s mbuf pkthdr in "to". 421108466Ssam * "from" must have M_PKTHDR set, and "to" must be empty. 422108466Ssam * In particular, this does a deep copy of the packet tags. 423108466Ssam */ 424108466Ssamint 425108466Ssamm_dup_pkthdr(struct mbuf *to, struct mbuf *from, int how) 426108466Ssam{ 427108466Ssam 428108466Ssam#if 0 429108466Ssam /* 430108466Ssam * The mbuf allocator only initializes the pkthdr 431108466Ssam * when the mbuf is allocated with MGETHDR. Many users 432108466Ssam * (e.g. m_copy*, m_prepend) use MGET and then 433108466Ssam * smash the pkthdr as needed causing these 434108466Ssam * assertions to trip. For now just disable them. 435108466Ssam */ 436113255Sdes M_ASSERTPKTHDR(to); 437113487Srwatson /* Note: with MAC, this may not be a good assertion. */ 438108466Ssam KASSERT(SLIST_EMPTY(&to->m_pkthdr.tags), ("m_dup_pkthdr: to has tags")); 439108466Ssam#endif 440132488Salfred MBUF_CHECKSLEEP(how); 441108466Ssam#ifdef MAC 442108466Ssam if (to->m_flags & M_PKTHDR) 443113487Srwatson m_tag_delete_chain(to, NULL); 444108466Ssam#endif 445112733Ssilby to->m_flags = (from->m_flags & M_COPYFLAGS) | (to->m_flags & M_EXT); 446112733Ssilby if ((to->m_flags & M_EXT) == 0) 447112733Ssilby to->m_data = to->m_pktdat; 448100960Srwatson to->m_pkthdr = from->m_pkthdr; 449108466Ssam SLIST_INIT(&to->m_pkthdr.tags); 450113480Srwatson return (m_tag_copy_chain(to, from, MBTOM(how))); 451100960Srwatson} 452100960Srwatson 453100960Srwatson/* 4541541Srgrimes * Lesser-used path for M_PREPEND: 4551541Srgrimes * allocate new mbuf to prepend to chain, 4561541Srgrimes * copy junk along. 4571541Srgrimes */ 4581541Srgrimesstruct mbuf * 45972356Sbmilekicm_prepend(struct mbuf *m, int len, int how) 4601541Srgrimes{ 4611541Srgrimes struct mbuf *mn; 4621541Srgrimes 463117770Ssilby if (m->m_flags & M_PKTHDR) 464117770Ssilby MGETHDR(mn, how, m->m_type); 465117770Ssilby else 466117770Ssilby MGET(mn, how, m->m_type); 46772356Sbmilekic if (mn == NULL) { 4681541Srgrimes m_freem(m); 46972356Sbmilekic return (NULL); 4701541Srgrimes } 471113487Srwatson if (m->m_flags & M_PKTHDR) 472108466Ssam M_MOVE_PKTHDR(mn, m); 4731541Srgrimes mn->m_next = m; 4741541Srgrimes m = mn; 4751541Srgrimes if (len < MHLEN) 4761541Srgrimes MH_ALIGN(m, len); 4771541Srgrimes m->m_len = len; 4781541Srgrimes return (m); 4791541Srgrimes} 4801541Srgrimes 4811541Srgrimes/* 4821541Srgrimes * Make a copy of an mbuf chain starting "off0" bytes from the beginning, 4831541Srgrimes * continuing for "len" bytes. If len is M_COPYALL, copy to end of mbuf. 484111119Simp * The wait parameter is a choice of M_TRYWAIT/M_DONTWAIT from caller. 48554002Sarchie * Note that the copy is read-only, because clusters are not copied, 48654002Sarchie * only their reference counts are incremented. 4871541Srgrimes */ 4881541Srgrimesstruct mbuf * 48972356Sbmilekicm_copym(struct mbuf *m, int off0, int len, int wait) 4901541Srgrimes{ 49172356Sbmilekic struct mbuf *n, **np; 49272356Sbmilekic int off = off0; 4931541Srgrimes struct mbuf *top; 4941541Srgrimes int copyhdr = 0; 4951541Srgrimes 49652201Salfred KASSERT(off >= 0, ("m_copym, negative off %d", off)); 49752201Salfred KASSERT(len >= 0, ("m_copym, negative len %d", len)); 498132488Salfred MBUF_CHECKSLEEP(wait); 4991541Srgrimes if (off == 0 && m->m_flags & M_PKTHDR) 5001541Srgrimes copyhdr = 1; 5011541Srgrimes while (off > 0) { 50252201Salfred KASSERT(m != NULL, ("m_copym, offset > size of mbuf chain")); 5031541Srgrimes if (off < m->m_len) 5041541Srgrimes break; 5051541Srgrimes off -= m->m_len; 5061541Srgrimes m = m->m_next; 5071541Srgrimes } 5081541Srgrimes np = ⊤ 5091541Srgrimes top = 0; 5101541Srgrimes while (len > 0) { 51172356Sbmilekic if (m == NULL) { 51252201Salfred KASSERT(len == M_COPYALL, 51352201Salfred ("m_copym, length > size of mbuf chain")); 5141541Srgrimes break; 5151541Srgrimes } 516117770Ssilby if (copyhdr) 517117770Ssilby MGETHDR(n, wait, m->m_type); 518117770Ssilby else 519117770Ssilby MGET(n, wait, m->m_type); 5201541Srgrimes *np = n; 52172356Sbmilekic if (n == NULL) 5221541Srgrimes goto nospace; 5231541Srgrimes if (copyhdr) { 524108466Ssam if (!m_dup_pkthdr(n, m, wait)) 525108466Ssam goto nospace; 5261541Srgrimes if (len == M_COPYALL) 5271541Srgrimes n->m_pkthdr.len -= off0; 5281541Srgrimes else 5291541Srgrimes n->m_pkthdr.len = len; 5301541Srgrimes copyhdr = 0; 5311541Srgrimes } 5321541Srgrimes n->m_len = min(len, m->m_len - off); 5331541Srgrimes if (m->m_flags & M_EXT) { 5341541Srgrimes n->m_data = m->m_data + off; 5351541Srgrimes n->m_ext = m->m_ext; 5361541Srgrimes n->m_flags |= M_EXT; 53764837Sdwmalone MEXT_ADD_REF(m); 538141668Sbmilekic n->m_ext.ref_cnt = m->m_ext.ref_cnt; 5391541Srgrimes } else 5401541Srgrimes bcopy(mtod(m, caddr_t)+off, mtod(n, caddr_t), 541103569Sbmilekic (u_int)n->m_len); 5421541Srgrimes if (len != M_COPYALL) 5431541Srgrimes len -= n->m_len; 5441541Srgrimes off = 0; 5451541Srgrimes m = m->m_next; 5461541Srgrimes np = &n->m_next; 5471541Srgrimes } 54878592Sbmilekic if (top == NULL) 54978592Sbmilekic mbstat.m_mcfail++; /* XXX: No consistency. */ 55078592Sbmilekic 5511541Srgrimes return (top); 5521541Srgrimesnospace: 5531541Srgrimes m_freem(top); 55478592Sbmilekic mbstat.m_mcfail++; /* XXX: No consistency. */ 55572356Sbmilekic return (NULL); 5561541Srgrimes} 5571541Srgrimes 5581541Srgrimes/* 559149602Sandre * Returns mbuf chain with new head for the prepending case. 560149602Sandre * Copies from mbuf (chain) n from off for len to mbuf (chain) m 561149602Sandre * either prepending or appending the data. 562149602Sandre * The resulting mbuf (chain) m is fully writeable. 563149602Sandre * m is destination (is made writeable) 564149602Sandre * n is source, off is offset in source, len is len from offset 565149602Sandre * dir, 0 append, 1 prepend 566149602Sandre * how, wait or nowait 567149602Sandre */ 568149602Sandre 569149602Sandrestatic int 570149602Sandrem_bcopyxxx(void *s, void *t, u_int len) 571149602Sandre{ 572149602Sandre bcopy(s, t, (size_t)len); 573149602Sandre return 0; 574149602Sandre} 575149602Sandre 576149602Sandrestruct mbuf * 577149602Sandrem_copymdata(struct mbuf *m, struct mbuf *n, int off, int len, 578149602Sandre int prep, int how) 579149602Sandre{ 580149602Sandre struct mbuf *mm, *x, *z; 581149602Sandre caddr_t p; 582149602Sandre int i, mlen, nlen = 0; 583149602Sandre caddr_t buf[MLEN]; 584149602Sandre 585149602Sandre KASSERT(m != NULL && n != NULL, ("m_copymdata, no target or source")); 586149602Sandre KASSERT(off >= 0, ("m_copymdata, negative off %d", off)); 587149602Sandre KASSERT(len >= 0, ("m_copymdata, negative len %d", len)); 588149602Sandre KASSERT(prep == 0 || prep == 1, ("m_copymdata, unknown direction %d", prep)); 589149602Sandre 590149602Sandre /* Make sure environment is sane. */ 591149602Sandre for (z = m; z != NULL; z = z->m_next) { 592149602Sandre mlen += z->m_len; 593149602Sandre if (!M_WRITABLE(z)) { 594149602Sandre /* Make clusters writeable. */ 595149602Sandre if (z->m_flags & M_RDONLY) 596149602Sandre return NULL; /* Can't handle ext ref. */ 597149602Sandre x = m_getcl(how, MT_DATA, 0); 598149602Sandre if (!x) 599149602Sandre return NULL; 600149602Sandre bcopy(z->m_ext.ext_buf, x->m_ext.ext_buf, x->m_ext.ext_size); 601149602Sandre p = x->m_ext.ext_buf + (z->m_data - z->m_ext.ext_buf); 602149602Sandre MEXT_REM_REF(z); /* XXX */ 603149602Sandre z->m_data = p; 604149602Sandre x->m_flags &= ~M_EXT; 605149602Sandre (void)m_free(x); 606149602Sandre } 607149602Sandre } 608149602Sandre mm = prep ? m : z; 609149602Sandre for (z = n; z != NULL; z = z->m_next) 610149602Sandre nlen += z->m_len; 611149602Sandre if (len == M_COPYALL) 612149602Sandre len = nlen - off; 613149602Sandre if (off + len > nlen || len < 1) 614149602Sandre return NULL; 615149602Sandre 616149602Sandre /* 617149602Sandre * Append/prepend the data. Allocating mbufs as necessary. 618149602Sandre */ 619149602Sandre /* Shortcut if enough free space in first/last mbuf. */ 620149602Sandre if (!prep && M_TRAILINGSPACE(mm) >= len) { 621149602Sandre m_apply(n, off, len, m_bcopyxxx, mtod(mm, caddr_t) + 622149602Sandre mm->m_len); 623149602Sandre mm->m_len += len; 624149602Sandre mm->m_pkthdr.len += len; 625149602Sandre return m; 626149602Sandre } 627149602Sandre if (prep && M_LEADINGSPACE(mm) >= len) { 628149602Sandre mm->m_data = mtod(mm, caddr_t) - len; 629149602Sandre m_apply(n, off, len, m_bcopyxxx, mtod(mm, caddr_t)); 630149602Sandre mm->m_len += len; 631149602Sandre mm->m_pkthdr.len += len; 632149602Sandre return mm; 633149602Sandre } 634149602Sandre 635149602Sandre /* Expand first/last mbuf to cluster if possible. */ 636149602Sandre if (!prep && !(mm->m_flags & M_EXT) && len > M_TRAILINGSPACE(mm)) { 637149602Sandre bcopy(mm->m_data, &buf, mm->m_len); 638149602Sandre m_clget(mm, how); 639149602Sandre if (!(mm->m_flags & M_EXT)) 640149602Sandre return NULL; 641149602Sandre bcopy(&buf, mm->m_ext.ext_buf, mm->m_len); 642149602Sandre mm->m_data = mm->m_ext.ext_buf; 643149602Sandre mm->m_pkthdr.header = NULL; 644149602Sandre } 645149602Sandre if (prep && !(mm->m_flags & M_EXT) && len > M_LEADINGSPACE(mm)) { 646149602Sandre bcopy(mm->m_data, &buf, mm->m_len); 647149602Sandre m_clget(mm, how); 648149602Sandre if (!(mm->m_flags & M_EXT)) 649149602Sandre return NULL; 650149602Sandre bcopy(&buf, (caddr_t *)mm->m_ext.ext_buf + 651149602Sandre mm->m_ext.ext_size - mm->m_len, mm->m_len); 652149602Sandre mm->m_data = (caddr_t)mm->m_ext.ext_buf + 653149602Sandre mm->m_ext.ext_size - mm->m_len; 654149602Sandre mm->m_pkthdr.header = NULL; 655149602Sandre } 656149602Sandre 657149602Sandre /* Append/prepend as many mbuf (clusters) as necessary to fit len. */ 658149602Sandre if (!prep && len > M_TRAILINGSPACE(mm)) { 659149602Sandre if (!m_getm(mm, len - M_TRAILINGSPACE(mm), how, MT_DATA)) 660149602Sandre return NULL; 661149602Sandre } 662149602Sandre if (prep && len > M_LEADINGSPACE(mm)) { 663149602Sandre if (!(z = m_getm(NULL, len - M_LEADINGSPACE(mm), how, MT_DATA))) 664149602Sandre return NULL; 665149602Sandre i = 0; 666149602Sandre for (x = z; x != NULL; x = x->m_next) { 667149602Sandre i += x->m_flags & M_EXT ? x->m_ext.ext_size : 668149602Sandre (x->m_flags & M_PKTHDR ? MHLEN : MLEN); 669149602Sandre if (!x->m_next) 670149602Sandre break; 671149602Sandre } 672149602Sandre z->m_data += i - len; 673149602Sandre m_move_pkthdr(mm, z); 674149602Sandre x->m_next = mm; 675149602Sandre mm = z; 676149602Sandre } 677149602Sandre 678149602Sandre /* Seek to start position in source mbuf. Optimization for long chains. */ 679149602Sandre while (off > 0) { 680149602Sandre if (off < n->m_len) 681149602Sandre break; 682149602Sandre off -= n->m_len; 683149602Sandre n = n->m_next; 684149602Sandre } 685149602Sandre 686149602Sandre /* Copy data into target mbuf. */ 687149602Sandre z = mm; 688149602Sandre while (len > 0) { 689149602Sandre KASSERT(z != NULL, ("m_copymdata, falling off target edge")); 690149602Sandre i = M_TRAILINGSPACE(z); 691149602Sandre m_apply(n, off, i, m_bcopyxxx, mtod(z, caddr_t) + z->m_len); 692149602Sandre z->m_len += i; 693149602Sandre /* fixup pkthdr.len if necessary */ 694149602Sandre if ((prep ? mm : m)->m_flags & M_PKTHDR) 695149602Sandre (prep ? mm : m)->m_pkthdr.len += i; 696149602Sandre off += i; 697149602Sandre len -= i; 698149602Sandre z = z->m_next; 699149602Sandre } 700149602Sandre return (prep ? mm : m); 701149602Sandre} 702149602Sandre 703149602Sandre/* 70415689Swollman * Copy an entire packet, including header (which must be present). 70515689Swollman * An optimization of the common case `m_copym(m, 0, M_COPYALL, how)'. 70654002Sarchie * Note that the copy is read-only, because clusters are not copied, 70754002Sarchie * only their reference counts are incremented. 70872750Sluigi * Preserve alignment of the first mbuf so if the creator has left 70972750Sluigi * some room at the beginning (e.g. for inserting protocol headers) 71072750Sluigi * the copies still have the room available. 71115689Swollman */ 71215689Swollmanstruct mbuf * 71372356Sbmilekicm_copypacket(struct mbuf *m, int how) 71415689Swollman{ 71515689Swollman struct mbuf *top, *n, *o; 71615689Swollman 717132488Salfred MBUF_CHECKSLEEP(how); 71815689Swollman MGET(n, how, m->m_type); 71915689Swollman top = n; 72072356Sbmilekic if (n == NULL) 72115689Swollman goto nospace; 72215689Swollman 723108466Ssam if (!m_dup_pkthdr(n, m, how)) 724108466Ssam goto nospace; 72515689Swollman n->m_len = m->m_len; 72615689Swollman if (m->m_flags & M_EXT) { 72715689Swollman n->m_data = m->m_data; 72815689Swollman n->m_ext = m->m_ext; 72915689Swollman n->m_flags |= M_EXT; 73064837Sdwmalone MEXT_ADD_REF(m); 731141668Sbmilekic n->m_ext.ref_cnt = m->m_ext.ref_cnt; 73215689Swollman } else { 73372750Sluigi n->m_data = n->m_pktdat + (m->m_data - m->m_pktdat ); 73415689Swollman bcopy(mtod(m, char *), mtod(n, char *), n->m_len); 73515689Swollman } 73615689Swollman 73715689Swollman m = m->m_next; 73815689Swollman while (m) { 73915689Swollman MGET(o, how, m->m_type); 74072356Sbmilekic if (o == NULL) 74115689Swollman goto nospace; 74215689Swollman 74315689Swollman n->m_next = o; 74415689Swollman n = n->m_next; 74515689Swollman 74615689Swollman n->m_len = m->m_len; 74715689Swollman if (m->m_flags & M_EXT) { 74815689Swollman n->m_data = m->m_data; 74915689Swollman n->m_ext = m->m_ext; 75015689Swollman n->m_flags |= M_EXT; 75164837Sdwmalone MEXT_ADD_REF(m); 752141668Sbmilekic n->m_ext.ref_cnt = m->m_ext.ref_cnt; 75315689Swollman } else { 75415689Swollman bcopy(mtod(m, char *), mtod(n, char *), n->m_len); 75515689Swollman } 75615689Swollman 75715689Swollman m = m->m_next; 75815689Swollman } 75915689Swollman return top; 76015689Swollmannospace: 76115689Swollman m_freem(top); 76278592Sbmilekic mbstat.m_mcfail++; /* XXX: No consistency. */ 76372356Sbmilekic return (NULL); 76415689Swollman} 76515689Swollman 76615689Swollman/* 7671541Srgrimes * Copy data from an mbuf chain starting "off" bytes from the beginning, 7681541Srgrimes * continuing for "len" bytes, into the indicated buffer. 7691541Srgrimes */ 7701549Srgrimesvoid 77181907Sjulianm_copydata(const struct mbuf *m, int off, int len, caddr_t cp) 7721541Srgrimes{ 773103569Sbmilekic u_int count; 7741541Srgrimes 77552201Salfred KASSERT(off >= 0, ("m_copydata, negative off %d", off)); 77652201Salfred KASSERT(len >= 0, ("m_copydata, negative len %d", len)); 7771541Srgrimes while (off > 0) { 77852201Salfred KASSERT(m != NULL, ("m_copydata, offset > size of mbuf chain")); 7791541Srgrimes if (off < m->m_len) 7801541Srgrimes break; 7811541Srgrimes off -= m->m_len; 7821541Srgrimes m = m->m_next; 7831541Srgrimes } 7841541Srgrimes while (len > 0) { 78552201Salfred KASSERT(m != NULL, ("m_copydata, length > size of mbuf chain")); 7861541Srgrimes count = min(m->m_len - off, len); 7871541Srgrimes bcopy(mtod(m, caddr_t) + off, cp, count); 7881541Srgrimes len -= count; 7891541Srgrimes cp += count; 7901541Srgrimes off = 0; 7911541Srgrimes m = m->m_next; 7921541Srgrimes } 7931541Srgrimes} 7941541Srgrimes 7951541Srgrimes/* 79654002Sarchie * Copy a packet header mbuf chain into a completely new chain, including 79754002Sarchie * copying any mbuf clusters. Use this instead of m_copypacket() when 79854002Sarchie * you need a writable copy of an mbuf chain. 79954002Sarchie */ 80054002Sarchiestruct mbuf * 80172356Sbmilekicm_dup(struct mbuf *m, int how) 80254002Sarchie{ 80354002Sarchie struct mbuf **p, *top = NULL; 80454002Sarchie int remain, moff, nsize; 80554002Sarchie 806132488Salfred MBUF_CHECKSLEEP(how); 80754002Sarchie /* Sanity check */ 80854002Sarchie if (m == NULL) 80972356Sbmilekic return (NULL); 810113255Sdes M_ASSERTPKTHDR(m); 81154002Sarchie 81254002Sarchie /* While there's more data, get a new mbuf, tack it on, and fill it */ 81354002Sarchie remain = m->m_pkthdr.len; 81454002Sarchie moff = 0; 81554002Sarchie p = ⊤ 81654002Sarchie while (remain > 0 || top == NULL) { /* allow m->m_pkthdr.len == 0 */ 81754002Sarchie struct mbuf *n; 81854002Sarchie 81954002Sarchie /* Get the next new mbuf */ 820129906Sbmilekic if (remain >= MINCLSIZE) { 821129906Sbmilekic n = m_getcl(how, m->m_type, 0); 822129906Sbmilekic nsize = MCLBYTES; 823129906Sbmilekic } else { 824129906Sbmilekic n = m_get(how, m->m_type); 825129906Sbmilekic nsize = MLEN; 826129906Sbmilekic } 82754002Sarchie if (n == NULL) 82854002Sarchie goto nospace; 829129906Sbmilekic 830129906Sbmilekic if (top == NULL) { /* First one, must be PKTHDR */ 831129906Sbmilekic if (!m_dup_pkthdr(n, m, how)) { 832129906Sbmilekic m_free(n); 833108466Ssam goto nospace; 834129906Sbmilekic } 83554002Sarchie nsize = MHLEN; 83654002Sarchie } 83754002Sarchie n->m_len = 0; 83854002Sarchie 83954002Sarchie /* Link it into the new chain */ 84054002Sarchie *p = n; 84154002Sarchie p = &n->m_next; 84254002Sarchie 84354002Sarchie /* Copy data from original mbuf(s) into new mbuf */ 84454002Sarchie while (n->m_len < nsize && m != NULL) { 84554002Sarchie int chunk = min(nsize - n->m_len, m->m_len - moff); 84654002Sarchie 84754002Sarchie bcopy(m->m_data + moff, n->m_data + n->m_len, chunk); 84854002Sarchie moff += chunk; 84954002Sarchie n->m_len += chunk; 85054002Sarchie remain -= chunk; 85154002Sarchie if (moff == m->m_len) { 85254002Sarchie m = m->m_next; 85354002Sarchie moff = 0; 85454002Sarchie } 85554002Sarchie } 85654002Sarchie 85754002Sarchie /* Check correct total mbuf length */ 85854002Sarchie KASSERT((remain > 0 && m != NULL) || (remain == 0 && m == NULL), 85987594Sobrien ("%s: bogus m_pkthdr.len", __func__)); 86054002Sarchie } 86154002Sarchie return (top); 86254002Sarchie 86354002Sarchienospace: 86454002Sarchie m_freem(top); 86578592Sbmilekic mbstat.m_mcfail++; /* XXX: No consistency. */ 86672356Sbmilekic return (NULL); 86754002Sarchie} 86854002Sarchie 86954002Sarchie/* 8701541Srgrimes * Concatenate mbuf chain n to m. 8711541Srgrimes * Both chains must be of the same type (e.g. MT_DATA). 8721541Srgrimes * Any m_pkthdr is not updated. 8731541Srgrimes */ 8741549Srgrimesvoid 87572356Sbmilekicm_cat(struct mbuf *m, struct mbuf *n) 8761541Srgrimes{ 8771541Srgrimes while (m->m_next) 8781541Srgrimes m = m->m_next; 8791541Srgrimes while (n) { 8801541Srgrimes if (m->m_flags & M_EXT || 8811541Srgrimes m->m_data + m->m_len + n->m_len >= &m->m_dat[MLEN]) { 8821541Srgrimes /* just join the two chains */ 8831541Srgrimes m->m_next = n; 8841541Srgrimes return; 8851541Srgrimes } 8861541Srgrimes /* splat the data from one into the other */ 8871541Srgrimes bcopy(mtod(n, caddr_t), mtod(m, caddr_t) + m->m_len, 8881541Srgrimes (u_int)n->m_len); 8891541Srgrimes m->m_len += n->m_len; 8901541Srgrimes n = m_free(n); 8911541Srgrimes } 8921541Srgrimes} 8931541Srgrimes 8941549Srgrimesvoid 89572356Sbmilekicm_adj(struct mbuf *mp, int req_len) 8961541Srgrimes{ 89772356Sbmilekic int len = req_len; 89872356Sbmilekic struct mbuf *m; 89972356Sbmilekic int count; 9001541Srgrimes 9011541Srgrimes if ((m = mp) == NULL) 9021541Srgrimes return; 9031541Srgrimes if (len >= 0) { 9041541Srgrimes /* 9051541Srgrimes * Trim from head. 9061541Srgrimes */ 9071541Srgrimes while (m != NULL && len > 0) { 9081541Srgrimes if (m->m_len <= len) { 9091541Srgrimes len -= m->m_len; 9101541Srgrimes m->m_len = 0; 9111541Srgrimes m = m->m_next; 9121541Srgrimes } else { 9131541Srgrimes m->m_len -= len; 9141541Srgrimes m->m_data += len; 9151541Srgrimes len = 0; 9161541Srgrimes } 9171541Srgrimes } 9181541Srgrimes m = mp; 9191541Srgrimes if (mp->m_flags & M_PKTHDR) 9201541Srgrimes m->m_pkthdr.len -= (req_len - len); 9211541Srgrimes } else { 9221541Srgrimes /* 9231541Srgrimes * Trim from tail. Scan the mbuf chain, 9241541Srgrimes * calculating its length and finding the last mbuf. 9251541Srgrimes * If the adjustment only affects this mbuf, then just 9261541Srgrimes * adjust and return. Otherwise, rescan and truncate 9271541Srgrimes * after the remaining size. 9281541Srgrimes */ 9291541Srgrimes len = -len; 9301541Srgrimes count = 0; 9311541Srgrimes for (;;) { 9321541Srgrimes count += m->m_len; 9331541Srgrimes if (m->m_next == (struct mbuf *)0) 9341541Srgrimes break; 9351541Srgrimes m = m->m_next; 9361541Srgrimes } 9371541Srgrimes if (m->m_len >= len) { 9381541Srgrimes m->m_len -= len; 9391541Srgrimes if (mp->m_flags & M_PKTHDR) 9401541Srgrimes mp->m_pkthdr.len -= len; 9411541Srgrimes return; 9421541Srgrimes } 9431541Srgrimes count -= len; 9441541Srgrimes if (count < 0) 9451541Srgrimes count = 0; 9461541Srgrimes /* 9471541Srgrimes * Correct length for chain is "count". 9481541Srgrimes * Find the mbuf with last data, adjust its length, 9491541Srgrimes * and toss data from remaining mbufs on chain. 9501541Srgrimes */ 9511541Srgrimes m = mp; 9521541Srgrimes if (m->m_flags & M_PKTHDR) 9531541Srgrimes m->m_pkthdr.len = count; 9541541Srgrimes for (; m; m = m->m_next) { 9551541Srgrimes if (m->m_len >= count) { 9561541Srgrimes m->m_len = count; 957142350Ssam if (m->m_next != NULL) { 958142350Ssam m_freem(m->m_next); 959142350Ssam m->m_next = NULL; 960142350Ssam } 9611541Srgrimes break; 9621541Srgrimes } 9631541Srgrimes count -= m->m_len; 9641541Srgrimes } 9651541Srgrimes } 9661541Srgrimes} 9671541Srgrimes 9681541Srgrimes/* 9691541Srgrimes * Rearange an mbuf chain so that len bytes are contiguous 9701541Srgrimes * and in the data area of an mbuf (so that mtod and dtom 9711541Srgrimes * will work for a structure of size len). Returns the resulting 9721541Srgrimes * mbuf chain on success, frees it and returns null on failure. 9731541Srgrimes * If there is room, it will add up to max_protohdr-len extra bytes to the 9741541Srgrimes * contiguous region in an attempt to avoid being called next time. 9751541Srgrimes */ 9761541Srgrimesstruct mbuf * 97772356Sbmilekicm_pullup(struct mbuf *n, int len) 9781541Srgrimes{ 97972356Sbmilekic struct mbuf *m; 98072356Sbmilekic int count; 9811541Srgrimes int space; 9821541Srgrimes 9831541Srgrimes /* 9841541Srgrimes * If first mbuf has no cluster, and has room for len bytes 9851541Srgrimes * without shifting current data, pullup into it, 9861541Srgrimes * otherwise allocate a new mbuf to prepend to the chain. 9871541Srgrimes */ 9881541Srgrimes if ((n->m_flags & M_EXT) == 0 && 9891541Srgrimes n->m_data + len < &n->m_dat[MLEN] && n->m_next) { 9901541Srgrimes if (n->m_len >= len) 9911541Srgrimes return (n); 9921541Srgrimes m = n; 9931541Srgrimes n = n->m_next; 9941541Srgrimes len -= m->m_len; 9951541Srgrimes } else { 9961541Srgrimes if (len > MHLEN) 9971541Srgrimes goto bad; 998111119Simp MGET(m, M_DONTWAIT, n->m_type); 99972356Sbmilekic if (m == NULL) 10001541Srgrimes goto bad; 10011541Srgrimes m->m_len = 0; 1002108466Ssam if (n->m_flags & M_PKTHDR) 1003108466Ssam M_MOVE_PKTHDR(m, n); 10041541Srgrimes } 10051541Srgrimes space = &m->m_dat[MLEN] - (m->m_data + m->m_len); 10061541Srgrimes do { 10071541Srgrimes count = min(min(max(len, max_protohdr), space), n->m_len); 10081541Srgrimes bcopy(mtod(n, caddr_t), mtod(m, caddr_t) + m->m_len, 1009103569Sbmilekic (u_int)count); 10101541Srgrimes len -= count; 10111541Srgrimes m->m_len += count; 10121541Srgrimes n->m_len -= count; 10131541Srgrimes space -= count; 10141541Srgrimes if (n->m_len) 10151541Srgrimes n->m_data += count; 10161541Srgrimes else 10171541Srgrimes n = m_free(n); 10181541Srgrimes } while (len > 0 && n); 10191541Srgrimes if (len > 0) { 10201541Srgrimes (void) m_free(m); 10211541Srgrimes goto bad; 10221541Srgrimes } 10231541Srgrimes m->m_next = n; 10241541Srgrimes return (m); 10251541Srgrimesbad: 10261541Srgrimes m_freem(n); 102778592Sbmilekic mbstat.m_mpfail++; /* XXX: No consistency. */ 102872356Sbmilekic return (NULL); 10291541Srgrimes} 10301541Srgrimes 10311541Srgrimes/* 1032143761Sjmg * Like m_pullup(), except a new mbuf is always allocated, and we allow 1033143761Sjmg * the amount of empty space before the data in the new mbuf to be specified 1034143761Sjmg * (in the event that the caller expects to prepend later). 1035143761Sjmg */ 1036143761Sjmgint MSFail; 1037143761Sjmg 1038143761Sjmgstruct mbuf * 1039143761Sjmgm_copyup(struct mbuf *n, int len, int dstoff) 1040143761Sjmg{ 1041143761Sjmg struct mbuf *m; 1042143761Sjmg int count, space; 1043143761Sjmg 1044143761Sjmg if (len > (MHLEN - dstoff)) 1045143761Sjmg goto bad; 1046143761Sjmg MGET(m, M_DONTWAIT, n->m_type); 1047143761Sjmg if (m == NULL) 1048143761Sjmg goto bad; 1049143761Sjmg m->m_len = 0; 1050143761Sjmg if (n->m_flags & M_PKTHDR) 1051143761Sjmg M_MOVE_PKTHDR(m, n); 1052143761Sjmg m->m_data += dstoff; 1053143761Sjmg space = &m->m_dat[MLEN] - (m->m_data + m->m_len); 1054143761Sjmg do { 1055143761Sjmg count = min(min(max(len, max_protohdr), space), n->m_len); 1056143761Sjmg memcpy(mtod(m, caddr_t) + m->m_len, mtod(n, caddr_t), 1057143761Sjmg (unsigned)count); 1058143761Sjmg len -= count; 1059143761Sjmg m->m_len += count; 1060143761Sjmg n->m_len -= count; 1061143761Sjmg space -= count; 1062143761Sjmg if (n->m_len) 1063143761Sjmg n->m_data += count; 1064143761Sjmg else 1065143761Sjmg n = m_free(n); 1066143761Sjmg } while (len > 0 && n); 1067143761Sjmg if (len > 0) { 1068143761Sjmg (void) m_free(m); 1069143761Sjmg goto bad; 1070143761Sjmg } 1071143761Sjmg m->m_next = n; 1072143761Sjmg return (m); 1073143761Sjmg bad: 1074143761Sjmg m_freem(n); 1075143761Sjmg MSFail++; 1076143761Sjmg return (NULL); 1077143761Sjmg} 1078143761Sjmg 1079143761Sjmg/* 10801541Srgrimes * Partition an mbuf chain in two pieces, returning the tail -- 10811541Srgrimes * all but the first len0 bytes. In case of failure, it returns NULL and 10821541Srgrimes * attempts to restore the chain to its original state. 108397681Sarchie * 108497681Sarchie * Note that the resulting mbufs might be read-only, because the new 108597681Sarchie * mbuf can end up sharing an mbuf cluster with the original mbuf if 108697681Sarchie * the "breaking point" happens to lie within a cluster mbuf. Use the 108797681Sarchie * M_WRITABLE() macro to check for this case. 10881541Srgrimes */ 10891541Srgrimesstruct mbuf * 109072356Sbmilekicm_split(struct mbuf *m0, int len0, int wait) 10911541Srgrimes{ 109272356Sbmilekic struct mbuf *m, *n; 1093103569Sbmilekic u_int len = len0, remain; 10941541Srgrimes 1095132488Salfred MBUF_CHECKSLEEP(wait); 10961541Srgrimes for (m = m0; m && len > m->m_len; m = m->m_next) 10971541Srgrimes len -= m->m_len; 109872356Sbmilekic if (m == NULL) 109972356Sbmilekic return (NULL); 11001541Srgrimes remain = m->m_len - len; 11011541Srgrimes if (m0->m_flags & M_PKTHDR) { 11021541Srgrimes MGETHDR(n, wait, m0->m_type); 110372356Sbmilekic if (n == NULL) 110472356Sbmilekic return (NULL); 11051541Srgrimes n->m_pkthdr.rcvif = m0->m_pkthdr.rcvif; 11061541Srgrimes n->m_pkthdr.len = m0->m_pkthdr.len - len0; 11071541Srgrimes m0->m_pkthdr.len = len0; 11081541Srgrimes if (m->m_flags & M_EXT) 11091541Srgrimes goto extpacket; 11101541Srgrimes if (remain > MHLEN) { 11111541Srgrimes /* m can't be the lead packet */ 11121541Srgrimes MH_ALIGN(n, 0); 11131541Srgrimes n->m_next = m_split(m, len, wait); 111472356Sbmilekic if (n->m_next == NULL) { 11151541Srgrimes (void) m_free(n); 111672356Sbmilekic return (NULL); 111794471Shsu } else { 111894471Shsu n->m_len = 0; 11191541Srgrimes return (n); 112094471Shsu } 11211541Srgrimes } else 11221541Srgrimes MH_ALIGN(n, remain); 11231541Srgrimes } else if (remain == 0) { 11241541Srgrimes n = m->m_next; 112572356Sbmilekic m->m_next = NULL; 11261541Srgrimes return (n); 11271541Srgrimes } else { 11281541Srgrimes MGET(n, wait, m->m_type); 112972356Sbmilekic if (n == NULL) 113072356Sbmilekic return (NULL); 11311541Srgrimes M_ALIGN(n, remain); 11321541Srgrimes } 11331541Srgrimesextpacket: 11341541Srgrimes if (m->m_flags & M_EXT) { 11351541Srgrimes n->m_flags |= M_EXT; 11361541Srgrimes n->m_ext = m->m_ext; 113764837Sdwmalone MEXT_ADD_REF(m); 1138141668Sbmilekic n->m_ext.ref_cnt = m->m_ext.ref_cnt; 11391541Srgrimes n->m_data = m->m_data + len; 11401541Srgrimes } else { 11411541Srgrimes bcopy(mtod(m, caddr_t) + len, mtod(n, caddr_t), remain); 11421541Srgrimes } 11431541Srgrimes n->m_len = remain; 11441541Srgrimes m->m_len = len; 11451541Srgrimes n->m_next = m->m_next; 114672356Sbmilekic m->m_next = NULL; 11471541Srgrimes return (n); 11481541Srgrimes} 11491541Srgrimes/* 11501541Srgrimes * Routine to copy from device local memory into mbufs. 115178508Sbmilekic * Note that `off' argument is offset into first mbuf of target chain from 115278508Sbmilekic * which to begin copying the data to. 11531541Srgrimes */ 11541541Srgrimesstruct mbuf * 115578508Sbmilekicm_devget(char *buf, int totlen, int off, struct ifnet *ifp, 115672356Sbmilekic void (*copy)(char *from, caddr_t to, u_int len)) 11571541Srgrimes{ 115872356Sbmilekic struct mbuf *m; 1159129906Sbmilekic struct mbuf *top = NULL, **mp = ⊤ 116078508Sbmilekic int len; 11611541Srgrimes 116278508Sbmilekic if (off < 0 || off > MHLEN) 116378508Sbmilekic return (NULL); 116478508Sbmilekic 1165129906Sbmilekic while (totlen > 0) { 1166129906Sbmilekic if (top == NULL) { /* First one, must be PKTHDR */ 1167129906Sbmilekic if (totlen + off >= MINCLSIZE) { 1168129906Sbmilekic m = m_getcl(M_DONTWAIT, MT_DATA, M_PKTHDR); 1169129906Sbmilekic len = MCLBYTES; 1170129906Sbmilekic } else { 1171129906Sbmilekic m = m_gethdr(M_DONTWAIT, MT_DATA); 1172129906Sbmilekic len = MHLEN; 11731541Srgrimes 1174129906Sbmilekic /* Place initial small packet/header at end of mbuf */ 1175129906Sbmilekic if (m && totlen + off + max_linkhdr <= MLEN) { 1176129906Sbmilekic m->m_data += max_linkhdr; 1177129906Sbmilekic len -= max_linkhdr; 1178129906Sbmilekic } 1179129906Sbmilekic } 1180129906Sbmilekic if (m == NULL) 1181129906Sbmilekic return NULL; 1182129906Sbmilekic m->m_pkthdr.rcvif = ifp; 1183129906Sbmilekic m->m_pkthdr.len = totlen; 1184129906Sbmilekic } else { 1185129906Sbmilekic if (totlen + off >= MINCLSIZE) { 1186129906Sbmilekic m = m_getcl(M_DONTWAIT, MT_DATA, 0); 1187129906Sbmilekic len = MCLBYTES; 1188129906Sbmilekic } else { 1189129906Sbmilekic m = m_get(M_DONTWAIT, MT_DATA); 1190129906Sbmilekic len = MLEN; 1191129906Sbmilekic } 119272356Sbmilekic if (m == NULL) { 11931541Srgrimes m_freem(top); 1194129906Sbmilekic return NULL; 11951541Srgrimes } 11961541Srgrimes } 119778508Sbmilekic if (off) { 119878508Sbmilekic m->m_data += off; 119978508Sbmilekic len -= off; 120078508Sbmilekic off = 0; 120178508Sbmilekic } 120278508Sbmilekic m->m_len = len = min(totlen, len); 12031541Srgrimes if (copy) 1204103569Sbmilekic copy(buf, mtod(m, caddr_t), (u_int)len); 12051541Srgrimes else 1206103569Sbmilekic bcopy(buf, mtod(m, caddr_t), (u_int)len); 120778508Sbmilekic buf += len; 12081541Srgrimes *mp = m; 12091541Srgrimes mp = &m->m_next; 12101541Srgrimes totlen -= len; 12111541Srgrimes } 12121541Srgrimes return (top); 12131541Srgrimes} 12143352Sphk 12153352Sphk/* 12163352Sphk * Copy data from a buffer back into the indicated mbuf chain, 12173352Sphk * starting "off" bytes from the beginning, extending the mbuf 12183352Sphk * chain if necessary. 12193352Sphk */ 12203352Sphkvoid 1221128402Sluigim_copyback(struct mbuf *m0, int off, int len, c_caddr_t cp) 12223352Sphk{ 122372356Sbmilekic int mlen; 122472356Sbmilekic struct mbuf *m = m0, *n; 12253352Sphk int totlen = 0; 12263352Sphk 122772356Sbmilekic if (m0 == NULL) 12283352Sphk return; 12293352Sphk while (off > (mlen = m->m_len)) { 12303352Sphk off -= mlen; 12313352Sphk totlen += mlen; 123272356Sbmilekic if (m->m_next == NULL) { 1233129906Sbmilekic n = m_get(M_DONTWAIT, m->m_type); 123472356Sbmilekic if (n == NULL) 12353352Sphk goto out; 1236129906Sbmilekic bzero(mtod(n, caddr_t), MLEN); 12373352Sphk n->m_len = min(MLEN, len + off); 12383352Sphk m->m_next = n; 12393352Sphk } 12403352Sphk m = m->m_next; 12413352Sphk } 12423352Sphk while (len > 0) { 12433352Sphk mlen = min (m->m_len - off, len); 1244103569Sbmilekic bcopy(cp, off + mtod(m, caddr_t), (u_int)mlen); 12453352Sphk cp += mlen; 12463352Sphk len -= mlen; 12473352Sphk mlen += off; 12483352Sphk off = 0; 12493352Sphk totlen += mlen; 12503352Sphk if (len == 0) 12513352Sphk break; 125272356Sbmilekic if (m->m_next == NULL) { 1253111119Simp n = m_get(M_DONTWAIT, m->m_type); 125472356Sbmilekic if (n == NULL) 12553352Sphk break; 12563352Sphk n->m_len = min(MLEN, len); 12573352Sphk m->m_next = n; 12583352Sphk } 12593352Sphk m = m->m_next; 12603352Sphk } 12613352Sphkout: if (((m = m0)->m_flags & M_PKTHDR) && (m->m_pkthdr.len < totlen)) 12623352Sphk m->m_pkthdr.len = totlen; 12633352Sphk} 126452756Sphk 1265123557Sbms/* 1266138541Ssam * Append the specified data to the indicated mbuf chain, 1267138541Ssam * Extend the mbuf chain if the new data does not fit in 1268138541Ssam * existing space. 1269138541Ssam * 1270138541Ssam * Return 1 if able to complete the job; otherwise 0. 1271138541Ssam */ 1272138541Ssamint 1273138541Ssamm_append(struct mbuf *m0, int len, c_caddr_t cp) 1274138541Ssam{ 1275138541Ssam struct mbuf *m, *n; 1276138541Ssam int remainder, space; 1277138541Ssam 1278138541Ssam for (m = m0; m->m_next != NULL; m = m->m_next) 1279138541Ssam ; 1280138541Ssam remainder = len; 1281138541Ssam space = M_TRAILINGSPACE(m); 1282138541Ssam if (space > 0) { 1283138541Ssam /* 1284138541Ssam * Copy into available space. 1285138541Ssam */ 1286138541Ssam if (space > remainder) 1287138541Ssam space = remainder; 1288138541Ssam bcopy(cp, mtod(m, caddr_t) + m->m_len, space); 1289138541Ssam m->m_len += space; 1290138541Ssam cp += space, remainder -= space; 1291138541Ssam } 1292138541Ssam while (remainder > 0) { 1293138541Ssam /* 1294138541Ssam * Allocate a new mbuf; could check space 1295138541Ssam * and allocate a cluster instead. 1296138541Ssam */ 1297138541Ssam n = m_get(M_DONTWAIT, m->m_type); 1298138541Ssam if (n == NULL) 1299138541Ssam break; 1300138541Ssam n->m_len = min(MLEN, remainder); 1301138894Ssam bcopy(cp, mtod(n, caddr_t), n->m_len); 1302138894Ssam cp += n->m_len, remainder -= n->m_len; 1303138541Ssam m->m_next = n; 1304138541Ssam m = n; 1305138541Ssam } 1306138541Ssam if (m0->m_flags & M_PKTHDR) 1307138541Ssam m0->m_pkthdr.len += len - remainder; 1308138541Ssam return (remainder == 0); 1309138541Ssam} 1310138541Ssam 1311138541Ssam/* 1312123557Sbms * Apply function f to the data in an mbuf chain starting "off" bytes from 1313123557Sbms * the beginning, continuing for "len" bytes. 1314123557Sbms */ 1315123557Sbmsint 1316123557Sbmsm_apply(struct mbuf *m, int off, int len, 1317123564Sbms int (*f)(void *, void *, u_int), void *arg) 1318123557Sbms{ 1319123564Sbms u_int count; 1320123557Sbms int rval; 1321123557Sbms 1322123557Sbms KASSERT(off >= 0, ("m_apply, negative off %d", off)); 1323123557Sbms KASSERT(len >= 0, ("m_apply, negative len %d", len)); 1324123557Sbms while (off > 0) { 1325123557Sbms KASSERT(m != NULL, ("m_apply, offset > size of mbuf chain")); 1326123557Sbms if (off < m->m_len) 1327123557Sbms break; 1328123557Sbms off -= m->m_len; 1329123557Sbms m = m->m_next; 1330123557Sbms } 1331123557Sbms while (len > 0) { 1332123557Sbms KASSERT(m != NULL, ("m_apply, offset > size of mbuf chain")); 1333123557Sbms count = min(m->m_len - off, len); 1334123557Sbms rval = (*f)(arg, mtod(m, caddr_t) + off, count); 1335123557Sbms if (rval) 1336123557Sbms return (rval); 1337123557Sbms len -= count; 1338123557Sbms off = 0; 1339123557Sbms m = m->m_next; 1340123557Sbms } 1341123557Sbms return (0); 1342123557Sbms} 1343123557Sbms 1344123557Sbms/* 1345123557Sbms * Return a pointer to mbuf/offset of location in mbuf chain. 1346123557Sbms */ 1347123557Sbmsstruct mbuf * 1348123557Sbmsm_getptr(struct mbuf *m, int loc, int *off) 1349123557Sbms{ 1350123557Sbms 1351123557Sbms while (loc >= 0) { 1352123564Sbms /* Normal end of search. */ 1353123557Sbms if (m->m_len > loc) { 1354123557Sbms *off = loc; 1355123557Sbms return (m); 1356123557Sbms } else { 1357123557Sbms loc -= m->m_len; 1358123557Sbms if (m->m_next == NULL) { 1359123557Sbms if (loc == 0) { 1360123564Sbms /* Point at the end of valid data. */ 1361123557Sbms *off = m->m_len; 1362123557Sbms return (m); 1363123564Sbms } 1364123564Sbms return (NULL); 1365123564Sbms } 1366123564Sbms m = m->m_next; 1367123557Sbms } 1368123557Sbms } 1369123557Sbms return (NULL); 1370123557Sbms} 1371123557Sbms 137252756Sphkvoid 1373135904Sjmgm_print(const struct mbuf *m, int maxlen) 137452756Sphk{ 137552756Sphk int len; 1376135904Sjmg int pdata; 137754906Seivind const struct mbuf *m2; 137852756Sphk 1379135904Sjmg if (m->m_flags & M_PKTHDR) 1380135904Sjmg len = m->m_pkthdr.len; 1381135904Sjmg else 1382135904Sjmg len = -1; 138352756Sphk m2 = m; 1384135904Sjmg while (m2 != NULL && (len == -1 || len)) { 1385135904Sjmg pdata = m2->m_len; 1386135904Sjmg if (maxlen != -1 && pdata > maxlen) 1387135904Sjmg pdata = maxlen; 1388135904Sjmg printf("mbuf: %p len: %d, next: %p, %b%s", m2, m2->m_len, 1389135904Sjmg m2->m_next, m2->m_flags, "\20\20freelist\17skipfw" 1390135904Sjmg "\11proto5\10proto4\7proto3\6proto2\5proto1\4rdonly" 1391135904Sjmg "\3eor\2pkthdr\1ext", pdata ? "" : "\n"); 1392135904Sjmg if (pdata) 1393135904Sjmg printf(", %*D\n", m2->m_len, (u_char *)m2->m_data, "-"); 1394135904Sjmg if (len != -1) 1395135904Sjmg len -= m2->m_len; 139652756Sphk m2 = m2->m_next; 139752756Sphk } 1398135904Sjmg if (len > 0) 1399135904Sjmg printf("%d bytes unaccounted for.\n", len); 140052756Sphk return; 140152756Sphk} 1402103540Sphk 1403103569Sbmilekicu_int 1404103540Sphkm_fixhdr(struct mbuf *m0) 1405103540Sphk{ 1406103569Sbmilekic u_int len; 1407103540Sphk 1408103544Sphk len = m_length(m0, NULL); 1409103544Sphk m0->m_pkthdr.len = len; 1410103544Sphk return (len); 1411103544Sphk} 1412103544Sphk 1413103569Sbmilekicu_int 1414103544Sphkm_length(struct mbuf *m0, struct mbuf **last) 1415103544Sphk{ 1416103544Sphk struct mbuf *m; 1417103569Sbmilekic u_int len; 1418103544Sphk 1419103544Sphk len = 0; 1420103544Sphk for (m = m0; m != NULL; m = m->m_next) { 1421103540Sphk len += m->m_len; 1422103544Sphk if (m->m_next == NULL) 1423103544Sphk break; 1424103540Sphk } 1425103544Sphk if (last != NULL) 1426103544Sphk *last = m; 1427103544Sphk return (len); 1428103540Sphk} 1429112777Ssilby 1430112777Ssilby/* 1431112777Ssilby * Defragment a mbuf chain, returning the shortest possible 1432112777Ssilby * chain of mbufs and clusters. If allocation fails and 1433112777Ssilby * this cannot be completed, NULL will be returned, but 1434112777Ssilby * the passed in chain will be unchanged. Upon success, 1435112777Ssilby * the original chain will be freed, and the new chain 1436112777Ssilby * will be returned. 1437112777Ssilby * 1438112777Ssilby * If a non-packet header is passed in, the original 1439112777Ssilby * mbuf (chain?) will be returned unharmed. 1440112777Ssilby */ 1441112777Ssilbystruct mbuf * 1442112777Ssilbym_defrag(struct mbuf *m0, int how) 1443112777Ssilby{ 1444125472Ssilby struct mbuf *m_new = NULL, *m_final = NULL; 1445125472Ssilby int progress = 0, length; 1446112777Ssilby 1447132488Salfred MBUF_CHECKSLEEP(how); 1448112777Ssilby if (!(m0->m_flags & M_PKTHDR)) 1449112777Ssilby return (m0); 1450112777Ssilby 1451117770Ssilby m_fixhdr(m0); /* Needed sanity check */ 1452117770Ssilby 1453113490Ssilby#ifdef MBUF_STRESS_TEST 1454113490Ssilby if (m_defragrandomfailures) { 1455113490Ssilby int temp = arc4random() & 0xff; 1456113490Ssilby if (temp == 0xba) 1457113490Ssilby goto nospace; 1458113490Ssilby } 1459113490Ssilby#endif 1460112777Ssilby 1461112777Ssilby if (m0->m_pkthdr.len > MHLEN) 1462112777Ssilby m_final = m_getcl(how, MT_DATA, M_PKTHDR); 1463112777Ssilby else 1464112777Ssilby m_final = m_gethdr(how, MT_DATA); 1465112777Ssilby 1466112777Ssilby if (m_final == NULL) 1467112777Ssilby goto nospace; 1468112777Ssilby 1469123740Speter if (m_dup_pkthdr(m_final, m0, how) == 0) 1470112777Ssilby goto nospace; 1471112777Ssilby 1472112777Ssilby m_new = m_final; 1473112777Ssilby 1474112777Ssilby while (progress < m0->m_pkthdr.len) { 1475112777Ssilby length = m0->m_pkthdr.len - progress; 1476112777Ssilby if (length > MCLBYTES) 1477112777Ssilby length = MCLBYTES; 1478112777Ssilby 1479112777Ssilby if (m_new == NULL) { 1480112777Ssilby if (length > MLEN) 1481112777Ssilby m_new = m_getcl(how, MT_DATA, 0); 1482112777Ssilby else 1483112777Ssilby m_new = m_get(how, MT_DATA); 1484112777Ssilby if (m_new == NULL) 1485112777Ssilby goto nospace; 1486112777Ssilby } 1487112777Ssilby 1488112777Ssilby m_copydata(m0, progress, length, mtod(m_new, caddr_t)); 1489112777Ssilby progress += length; 1490112777Ssilby m_new->m_len = length; 1491112777Ssilby if (m_new != m_final) 1492112777Ssilby m_cat(m_final, m_new); 1493112777Ssilby m_new = NULL; 1494112777Ssilby } 1495116455Ssilby#ifdef MBUF_STRESS_TEST 1496112777Ssilby if (m0->m_next == NULL) 1497112777Ssilby m_defraguseless++; 1498116455Ssilby#endif 1499112777Ssilby m_freem(m0); 1500112777Ssilby m0 = m_final; 1501116455Ssilby#ifdef MBUF_STRESS_TEST 1502112777Ssilby m_defragpackets++; 1503112777Ssilby m_defragbytes += m0->m_pkthdr.len; 1504116455Ssilby#endif 1505112777Ssilby return (m0); 1506112777Ssilbynospace: 1507116455Ssilby#ifdef MBUF_STRESS_TEST 1508112777Ssilby m_defragfailure++; 1509116455Ssilby#endif 1510112777Ssilby if (m_final) 1511112777Ssilby m_freem(m_final); 1512112777Ssilby return (NULL); 1513112777Ssilby} 1514119644Ssilby 1515119644Ssilby#ifdef MBUF_STRESS_TEST 1516119644Ssilby 1517119644Ssilby/* 1518119644Ssilby * Fragment an mbuf chain. There's no reason you'd ever want to do 1519119644Ssilby * this in normal usage, but it's great for stress testing various 1520119644Ssilby * mbuf consumers. 1521119644Ssilby * 1522119644Ssilby * If fragmentation is not possible, the original chain will be 1523119644Ssilby * returned. 1524119644Ssilby * 1525119644Ssilby * Possible length values: 1526119644Ssilby * 0 no fragmentation will occur 1527119644Ssilby * > 0 each fragment will be of the specified length 1528119644Ssilby * -1 each fragment will be the same random value in length 1529119644Ssilby * -2 each fragment's length will be entirely random 1530119644Ssilby * (Random values range from 1 to 256) 1531119644Ssilby */ 1532119644Ssilbystruct mbuf * 1533119644Ssilbym_fragment(struct mbuf *m0, int how, int length) 1534119644Ssilby{ 1535125472Ssilby struct mbuf *m_new = NULL, *m_final = NULL; 1536125472Ssilby int progress = 0; 1537119644Ssilby 1538119644Ssilby if (!(m0->m_flags & M_PKTHDR)) 1539119644Ssilby return (m0); 1540119644Ssilby 1541119644Ssilby if ((length == 0) || (length < -2)) 1542119644Ssilby return (m0); 1543119644Ssilby 1544119644Ssilby m_fixhdr(m0); /* Needed sanity check */ 1545119644Ssilby 1546119644Ssilby m_final = m_getcl(how, MT_DATA, M_PKTHDR); 1547119644Ssilby 1548119644Ssilby if (m_final == NULL) 1549119644Ssilby goto nospace; 1550119644Ssilby 1551123823Ssilby if (m_dup_pkthdr(m_final, m0, how) == 0) 1552119644Ssilby goto nospace; 1553119644Ssilby 1554119644Ssilby m_new = m_final; 1555119644Ssilby 1556119644Ssilby if (length == -1) 1557119644Ssilby length = 1 + (arc4random() & 255); 1558119644Ssilby 1559119644Ssilby while (progress < m0->m_pkthdr.len) { 1560119644Ssilby int fraglen; 1561119644Ssilby 1562119644Ssilby if (length > 0) 1563119644Ssilby fraglen = length; 1564119644Ssilby else 1565119644Ssilby fraglen = 1 + (arc4random() & 255); 1566119644Ssilby if (fraglen > m0->m_pkthdr.len - progress) 1567119644Ssilby fraglen = m0->m_pkthdr.len - progress; 1568119644Ssilby 1569119644Ssilby if (fraglen > MCLBYTES) 1570119644Ssilby fraglen = MCLBYTES; 1571119644Ssilby 1572119644Ssilby if (m_new == NULL) { 1573119644Ssilby m_new = m_getcl(how, MT_DATA, 0); 1574119644Ssilby if (m_new == NULL) 1575119644Ssilby goto nospace; 1576119644Ssilby } 1577119644Ssilby 1578119644Ssilby m_copydata(m0, progress, fraglen, mtod(m_new, caddr_t)); 1579119644Ssilby progress += fraglen; 1580119644Ssilby m_new->m_len = fraglen; 1581119644Ssilby if (m_new != m_final) 1582119644Ssilby m_cat(m_final, m_new); 1583119644Ssilby m_new = NULL; 1584119644Ssilby } 1585119644Ssilby m_freem(m0); 1586119644Ssilby m0 = m_final; 1587119644Ssilby return (m0); 1588119644Ssilbynospace: 1589119644Ssilby if (m_final) 1590119644Ssilby m_freem(m_final); 1591119644Ssilby /* Return the original chain on failure */ 1592119644Ssilby return (m0); 1593119644Ssilby} 1594119644Ssilby 1595119644Ssilby#endif 1596125296Ssilby 1597125296Ssilbystruct mbuf * 1598145883Semaxm_uiotombuf(struct uio *uio, int how, int len, int align) 1599125296Ssilby{ 1600125472Ssilby struct mbuf *m_new = NULL, *m_final = NULL; 1601125472Ssilby int progress = 0, error = 0, length, total; 1602125296Ssilby 1603125296Ssilby if (len > 0) 1604125296Ssilby total = min(uio->uio_resid, len); 1605125296Ssilby else 1606125296Ssilby total = uio->uio_resid; 1607145883Semax if (align >= MHLEN) 1608145883Semax goto nospace; 1609145883Semax if (total + align > MHLEN) 1610125296Ssilby m_final = m_getcl(how, MT_DATA, M_PKTHDR); 1611125296Ssilby else 1612125296Ssilby m_final = m_gethdr(how, MT_DATA); 1613125296Ssilby if (m_final == NULL) 1614125296Ssilby goto nospace; 1615145883Semax m_final->m_data += align; 1616125296Ssilby m_new = m_final; 1617125296Ssilby while (progress < total) { 1618125296Ssilby length = total - progress; 1619125296Ssilby if (length > MCLBYTES) 1620125296Ssilby length = MCLBYTES; 1621125296Ssilby if (m_new == NULL) { 1622125296Ssilby if (length > MLEN) 1623125296Ssilby m_new = m_getcl(how, MT_DATA, 0); 1624125296Ssilby else 1625125296Ssilby m_new = m_get(how, MT_DATA); 1626125296Ssilby if (m_new == NULL) 1627125296Ssilby goto nospace; 1628125296Ssilby } 1629125296Ssilby error = uiomove(mtod(m_new, void *), length, uio); 1630125296Ssilby if (error) 1631125296Ssilby goto nospace; 1632125296Ssilby progress += length; 1633125296Ssilby m_new->m_len = length; 1634125296Ssilby if (m_new != m_final) 1635125296Ssilby m_cat(m_final, m_new); 1636125296Ssilby m_new = NULL; 1637125296Ssilby } 1638125296Ssilby m_fixhdr(m_final); 1639125296Ssilby return (m_final); 1640125296Ssilbynospace: 1641125296Ssilby if (m_new) 1642125296Ssilby m_free(m_new); 1643125296Ssilby if (m_final) 1644125296Ssilby m_freem(m_final); 1645125296Ssilby return (NULL); 1646125296Ssilby} 1647148552Ssam 1648148552Ssam/* 1649148552Ssam * Set the m_data pointer of a newly-allocated mbuf 1650148552Ssam * to place an object of the specified size at the 1651148552Ssam * end of the mbuf, longword aligned. 1652148552Ssam */ 1653148552Ssamvoid 1654148552Ssamm_align(struct mbuf *m, int len) 1655148552Ssam{ 1656148552Ssam int adjust; 1657148552Ssam 1658148552Ssam if (m->m_flags & M_EXT) 1659148552Ssam adjust = m->m_ext.ext_size - len; 1660148552Ssam else if (m->m_flags & M_PKTHDR) 1661148552Ssam adjust = MHLEN - len; 1662148552Ssam else 1663148552Ssam adjust = MLEN - len; 1664148552Ssam m->m_data += adjust &~ (sizeof(long)-1); 1665148552Ssam} 1666