| 1 | /* |
| 2 | * Copyright (c) 2004 Jeffrey M. Hsu. All rights reserved. |
| 3 | * Copyright (c) 2004 The DragonFly Project. All rights reserved. |
| 4 | * |
| 5 | * This code is derived from software contributed to The DragonFly Project |
| 6 | * by Jeffrey M. Hsu. |
| 7 | * |
| 8 | * Redistribution and use in source and binary forms, with or without |
| 9 | * modification, are permitted provided that the following conditions |
| 10 | * are met: |
| 11 | * 1. Redistributions of source code must retain the above copyright |
| 12 | * notice, this list of conditions and the following disclaimer. |
| 13 | * 2. Redistributions in binary form must reproduce the above copyright |
| 14 | * notice, this list of conditions and the following disclaimer in the |
| 15 | * documentation and/or other materials provided with the distribution. |
| 16 | * 3. Neither the name of The DragonFly Project nor the names of its |
| 17 | * contributors may be used to endorse or promote products derived |
| 18 | * from this software without specific, prior written permission. |
| 19 | * |
| 20 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| 21 | * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| 22 | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS |
| 23 | * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE |
| 24 | * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, |
| 25 | * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, |
| 26 | * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
| 27 | * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED |
| 28 | * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, |
| 29 | * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT |
| 30 | * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 31 | * SUCH DAMAGE. |
| 32 | */ |
| 33 | |
| 34 | /* |
| 35 | * Copyright (c) 2004 Jeffrey M. Hsu. All rights reserved. |
| 36 | * |
| 37 | * License terms: all terms for the DragonFly license above plus the following: |
| 38 | * |
| 39 | * 4. All advertising materials mentioning features or use of this software |
| 40 | * must display the following acknowledgement: |
| 41 | * |
| 42 | * This product includes software developed by Jeffrey M. Hsu |
| 43 | * for the DragonFly Project. |
| 44 | * |
| 45 | * This requirement may be waived with permission from Jeffrey Hsu. |
| 46 | * This requirement will sunset and may be removed on July 8 2005, |
| 47 | * after which the standard DragonFly license (as shown above) will |
| 48 | * apply. |
| 49 | */ |
| 50 | |
| 51 | /* |
| 52 | * Copyright (c) 1982, 1986, 1988, 1991, 1993 |
| 53 | * The Regents of the University of California. All rights reserved. |
| 54 | * |
| 55 | * Redistribution and use in source and binary forms, with or without |
| 56 | * modification, are permitted provided that the following conditions |
| 57 | * are met: |
| 58 | * 1. Redistributions of source code must retain the above copyright |
| 59 | * notice, this list of conditions and the following disclaimer. |
| 60 | * 2. Redistributions in binary form must reproduce the above copyright |
| 61 | * notice, this list of conditions and the following disclaimer in the |
| 62 | * documentation and/or other materials provided with the distribution. |
| 63 | * 3. All advertising materials mentioning features or use of this software |
| 64 | * must display the following acknowledgement: |
| 65 | * This product includes software developed by the University of |
| 66 | * California, Berkeley and its contributors. |
| 67 | * 4. Neither the name of the University nor the names of its contributors |
| 68 | * may be used to endorse or promote products derived from this software |
| 69 | * without specific prior written permission. |
| 70 | * |
| 71 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
| 72 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 73 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 74 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
| 75 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 76 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 77 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 78 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 79 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 80 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 81 | * SUCH DAMAGE. |
| 82 | * |
| 83 | * @(#)uipc_mbuf.c 8.2 (Berkeley) 1/4/94 |
| 84 | * $FreeBSD: src/sys/kern/uipc_mbuf.c,v 1.51.2.24 2003/04/15 06:59:29 silby Exp $ |
| 85 | * $DragonFly: src/sys/kern/uipc_mbuf.c,v 1.58 2006/12/17 19:28:30 dillon Exp $ |
| 86 | */ |
| 87 | |
| 88 | #include "opt_param.h" |
| 89 | #include "opt_ddb.h" |
| 90 | #include "opt_mbuf_stress_test.h" |
| 91 | #include <sys/param.h> |
| 92 | #include <sys/systm.h> |
| 93 | #include <sys/malloc.h> |
| 94 | #include <sys/mbuf.h> |
| 95 | #include <sys/kernel.h> |
| 96 | #include <sys/sysctl.h> |
| 97 | #include <sys/domain.h> |
| 98 | #include <sys/objcache.h> |
| 99 | #include <sys/protosw.h> |
| 100 | #include <sys/uio.h> |
| 101 | #include <sys/thread.h> |
| 102 | #include <sys/globaldata.h> |
| 103 | #include <sys/serialize.h> |
| 104 | #include <sys/thread2.h> |
| 105 | |
| 106 | #include <vm/vm.h> |
| 107 | #include <vm/vm_kern.h> |
| 108 | #include <vm/vm_extern.h> |
| 109 | |
| 110 | #ifdef INVARIANTS |
| 111 | #include <machine/cpu.h> |
| 112 | #endif |
| 113 | |
| 114 | /* |
| 115 | * mbuf cluster meta-data |
| 116 | */ |
| 117 | struct mbcluster { |
| 118 | int32_t mcl_refs; |
| 119 | void *mcl_data; |
| 120 | struct lwkt_serialize mcl_serializer; |
| 121 | }; |
| 122 | |
| 123 | static void mbinit(void *); |
| 124 | SYSINIT(mbuf, SI_SUB_MBUF, SI_ORDER_FIRST, mbinit, NULL) |
| 125 | |
| 126 | static u_long mbtypes[MT_NTYPES]; |
| 127 | |
| 128 | struct mbstat mbstat; |
| 129 | int max_linkhdr; |
| 130 | int max_protohdr; |
| 131 | int max_hdr; |
| 132 | int max_datalen; |
| 133 | int m_defragpackets; |
| 134 | int m_defragbytes; |
| 135 | int m_defraguseless; |
| 136 | int m_defragfailure; |
| 137 | #ifdef MBUF_STRESS_TEST |
| 138 | int m_defragrandomfailures; |
| 139 | #endif |
| 140 | |
| 141 | struct objcache *mbuf_cache, *mbufphdr_cache; |
| 142 | struct objcache *mclmeta_cache; |
| 143 | struct objcache *mbufcluster_cache, *mbufphdrcluster_cache; |
| 144 | |
| 145 | int nmbclusters; |
| 146 | int nmbufs; |
| 147 | |
| 148 | SYSCTL_INT(_kern_ipc, KIPC_MAX_LINKHDR, max_linkhdr, CTLFLAG_RW, |
| 149 | &max_linkhdr, 0, ""); |
| 150 | SYSCTL_INT(_kern_ipc, KIPC_MAX_PROTOHDR, max_protohdr, CTLFLAG_RW, |
| 151 | &max_protohdr, 0, ""); |
| 152 | SYSCTL_INT(_kern_ipc, KIPC_MAX_HDR, max_hdr, CTLFLAG_RW, &max_hdr, 0, ""); |
| 153 | SYSCTL_INT(_kern_ipc, KIPC_MAX_DATALEN, max_datalen, CTLFLAG_RW, |
| 154 | &max_datalen, 0, ""); |
| 155 | SYSCTL_INT(_kern_ipc, OID_AUTO, mbuf_wait, CTLFLAG_RW, |
| 156 | &mbuf_wait, 0, ""); |
| 157 | SYSCTL_STRUCT(_kern_ipc, KIPC_MBSTAT, mbstat, CTLFLAG_RW, &mbstat, mbstat, ""); |
| 158 | SYSCTL_OPAQUE(_kern_ipc, OID_AUTO, mbtypes, CTLFLAG_RD, mbtypes, |
| 159 | sizeof(mbtypes), "LU", ""); |
| 160 | SYSCTL_INT(_kern_ipc, KIPC_NMBCLUSTERS, nmbclusters, CTLFLAG_RW, |
| 161 | &nmbclusters, 0, "Maximum number of mbuf clusters available"); |
| 162 | SYSCTL_INT(_kern_ipc, OID_AUTO, nmbufs, CTLFLAG_RW, &nmbufs, 0, |
| 163 | "Maximum number of mbufs available"); |
| 164 | |
| 165 | SYSCTL_INT(_kern_ipc, OID_AUTO, m_defragpackets, CTLFLAG_RD, |
| 166 | &m_defragpackets, 0, ""); |
| 167 | SYSCTL_INT(_kern_ipc, OID_AUTO, m_defragbytes, CTLFLAG_RD, |
| 168 | &m_defragbytes, 0, ""); |
| 169 | SYSCTL_INT(_kern_ipc, OID_AUTO, m_defraguseless, CTLFLAG_RD, |
| 170 | &m_defraguseless, 0, ""); |
| 171 | SYSCTL_INT(_kern_ipc, OID_AUTO, m_defragfailure, CTLFLAG_RD, |
| 172 | &m_defragfailure, 0, ""); |
| 173 | #ifdef MBUF_STRESS_TEST |
| 174 | SYSCTL_INT(_kern_ipc, OID_AUTO, m_defragrandomfailures, CTLFLAG_RW, |
| 175 | &m_defragrandomfailures, 0, ""); |
| 176 | #endif |
| 177 | |
| 178 | static MALLOC_DEFINE(M_MBUF, "mbuf", "mbuf"); |
| 179 | static MALLOC_DEFINE(M_MBUFCL, "mbufcl", "mbufcl"); |
| 180 | static MALLOC_DEFINE(M_MCLMETA, "mclmeta", "mclmeta"); |
| 181 | |
| 182 | static void m_reclaim (void); |
| 183 | static void m_mclref(void *arg); |
| 184 | static void m_mclfree(void *arg); |
| 185 | |
| 186 | #ifndef NMBCLUSTERS |
| 187 | #define NMBCLUSTERS (512 + maxusers * 16) |
| 188 | #endif |
| 189 | #ifndef NMBUFS |
| 190 | #define NMBUFS (nmbclusters * 2) |
| 191 | #endif |
| 192 | |
| 193 | /* |
| 194 | * Perform sanity checks of tunables declared above. |
| 195 | */ |
| 196 | static void |
| 197 | tunable_mbinit(void *dummy) |
| 198 | { |
| 199 | |
| 200 | /* |
| 201 | * This has to be done before VM init. |
| 202 | */ |
| 203 | nmbclusters = NMBCLUSTERS; |
| 204 | TUNABLE_INT_FETCH("kern.ipc.nmbclusters", &nmbclusters); |
| 205 | nmbufs = NMBUFS; |
| 206 | TUNABLE_INT_FETCH("kern.ipc.nmbufs", &nmbufs); |
| 207 | /* Sanity checks */ |
| 208 | if (nmbufs < nmbclusters * 2) |
| 209 | nmbufs = nmbclusters * 2; |
| 210 | |
| 211 | return; |
| 212 | } |
| 213 | SYSINIT(tunable_mbinit, SI_SUB_TUNABLES, SI_ORDER_ANY, tunable_mbinit, NULL); |
| 214 | |
| 215 | /* "number of clusters of pages" */ |
| 216 | #define NCL_INIT 1 |
| 217 | |
| 218 | #define NMB_INIT 16 |
| 219 | |
| 220 | /* |
| 221 | * The mbuf object cache only guarantees that m_next and m_nextpkt are |
| 222 | * NULL and that m_data points to the beginning of the data area. In |
| 223 | * particular, m_len and m_pkthdr.len are uninitialized. It is the |
| 224 | * responsibility of the caller to initialize those fields before use. |
| 225 | */ |
| 226 | |
| 227 | static boolean_t __inline |
| 228 | mbuf_ctor(void *obj, void *private, int ocflags) |
| 229 | { |
| 230 | struct mbuf *m = obj; |
| 231 | |
| 232 | m->m_next = NULL; |
| 233 | m->m_nextpkt = NULL; |
| 234 | m->m_data = m->m_dat; |
| 235 | m->m_flags = 0; |
| 236 | |
| 237 | return (TRUE); |
| 238 | } |
| 239 | |
| 240 | /* |
| 241 | * Initialize the mbuf and the packet header fields. |
| 242 | */ |
| 243 | static boolean_t |
| 244 | mbufphdr_ctor(void *obj, void *private, int ocflags) |
| 245 | { |
| 246 | struct mbuf *m = obj; |
| 247 | |
| 248 | m->m_next = NULL; |
| 249 | m->m_nextpkt = NULL; |
| 250 | m->m_data = m->m_pktdat; |
| 251 | m->m_flags = M_PKTHDR | M_PHCACHE; |
| 252 | |
| 253 | m->m_pkthdr.rcvif = NULL; /* eliminate XXX JH */ |
| 254 | SLIST_INIT(&m->m_pkthdr.tags); |
| 255 | m->m_pkthdr.csum_flags = 0; /* eliminate XXX JH */ |
| 256 | m->m_pkthdr.fw_flags = 0; /* eliminate XXX JH */ |
| 257 | |
| 258 | return (TRUE); |
| 259 | } |
| 260 | |
| 261 | /* |
| 262 | * A mbcluster object consists of 2K (MCLBYTES) cluster and a refcount. |
| 263 | */ |
| 264 | static boolean_t |
| 265 | mclmeta_ctor(void *obj, void *private, int ocflags) |
| 266 | { |
| 267 | struct mbcluster *cl = obj; |
| 268 | void *buf; |
| 269 | |
| 270 | if (ocflags & M_NOWAIT) |
| 271 | buf = kmalloc(MCLBYTES, M_MBUFCL, M_NOWAIT | M_ZERO); |
| 272 | else |
| 273 | buf = kmalloc(MCLBYTES, M_MBUFCL, M_INTWAIT | M_ZERO); |
| 274 | if (buf == NULL) |
| 275 | return (FALSE); |
| 276 | cl->mcl_refs = 0; |
| 277 | cl->mcl_data = buf; |
| 278 | lwkt_serialize_init(&cl->mcl_serializer); |
| 279 | return (TRUE); |
| 280 | } |
| 281 | |
| 282 | static void |
| 283 | mclmeta_dtor(void *obj, void *private) |
| 284 | { |
| 285 | struct mbcluster *mcl = obj; |
| 286 | |
| 287 | KKASSERT(mcl->mcl_refs == 0); |
| 288 | kfree(mcl->mcl_data, M_MBUFCL); |
| 289 | } |
| 290 | |
| 291 | static void |
| 292 | linkcluster(struct mbuf *m, struct mbcluster *cl) |
| 293 | { |
| 294 | /* |
| 295 | * Add the cluster to the mbuf. The caller will detect that the |
| 296 | * mbuf now has an attached cluster. |
| 297 | */ |
| 298 | m->m_ext.ext_arg = cl; |
| 299 | m->m_ext.ext_buf = cl->mcl_data; |
| 300 | m->m_ext.ext_ref = m_mclref; |
| 301 | m->m_ext.ext_free = m_mclfree; |
| 302 | m->m_ext.ext_size = MCLBYTES; |
| 303 | atomic_add_int(&cl->mcl_refs, 1); |
| 304 | |
| 305 | m->m_data = m->m_ext.ext_buf; |
| 306 | m->m_flags |= M_EXT | M_EXT_CLUSTER; |
| 307 | } |
| 308 | |
| 309 | static boolean_t |
| 310 | mbufphdrcluster_ctor(void *obj, void *private, int ocflags) |
| 311 | { |
| 312 | struct mbuf *m = obj; |
| 313 | struct mbcluster *cl; |
| 314 | |
| 315 | mbufphdr_ctor(obj, private, ocflags); |
| 316 | cl = objcache_get(mclmeta_cache, ocflags); |
| 317 | if (cl == NULL) |
| 318 | return (FALSE); |
| 319 | m->m_flags |= M_CLCACHE; |
| 320 | linkcluster(m, cl); |
| 321 | return (TRUE); |
| 322 | } |
| 323 | |
| 324 | static boolean_t |
| 325 | mbufcluster_ctor(void *obj, void *private, int ocflags) |
| 326 | { |
| 327 | struct mbuf *m = obj; |
| 328 | struct mbcluster *cl; |
| 329 | |
| 330 | mbuf_ctor(obj, private, ocflags); |
| 331 | cl = objcache_get(mclmeta_cache, ocflags); |
| 332 | if (cl == NULL) |
| 333 | return (FALSE); |
| 334 | m->m_flags |= M_CLCACHE; |
| 335 | linkcluster(m, cl); |
| 336 | return (TRUE); |
| 337 | } |
| 338 | |
| 339 | /* |
| 340 | * Used for both the cluster and cluster PHDR caches. |
| 341 | * |
| 342 | * The mbuf may have lost its cluster due to sharing, deal |
| 343 | * with the situation by checking M_EXT. |
| 344 | */ |
| 345 | static void |
| 346 | mbufcluster_dtor(void *obj, void *private) |
| 347 | { |
| 348 | struct mbuf *m = obj; |
| 349 | struct mbcluster *mcl; |
| 350 | |
| 351 | if (m->m_flags & M_EXT) { |
| 352 | KKASSERT((m->m_flags & M_EXT_CLUSTER) != 0); |
| 353 | mcl = m->m_ext.ext_arg; |
| 354 | KKASSERT(mcl->mcl_refs == 1); |
| 355 | mcl->mcl_refs = 0; |
| 356 | objcache_put(mclmeta_cache, mcl); |
| 357 | } |
| 358 | } |
| 359 | |
| 360 | struct objcache_malloc_args mbuf_malloc_args = { MSIZE, M_MBUF }; |
| 361 | struct objcache_malloc_args mclmeta_malloc_args = |
| 362 | { sizeof(struct mbcluster), M_MCLMETA }; |
| 363 | |
| 364 | /* ARGSUSED*/ |
| 365 | static void |
| 366 | mbinit(void *dummy) |
| 367 | { |
| 368 | mbstat.m_msize = MSIZE; |
| 369 | mbstat.m_mclbytes = MCLBYTES; |
| 370 | mbstat.m_minclsize = MINCLSIZE; |
| 371 | mbstat.m_mlen = MLEN; |
| 372 | mbstat.m_mhlen = MHLEN; |
| 373 | |
| 374 | mbuf_cache = objcache_create("mbuf", nmbufs, 0, |
| 375 | mbuf_ctor, NULL, NULL, |
| 376 | objcache_malloc_alloc, objcache_malloc_free, &mbuf_malloc_args); |
| 377 | mbufphdr_cache = objcache_create("mbuf pkt hdr", nmbufs, 64, |
| 378 | mbufphdr_ctor, NULL, NULL, |
| 379 | objcache_malloc_alloc, objcache_malloc_free, &mbuf_malloc_args); |
| 380 | mclmeta_cache = objcache_create("cluster mbuf", nmbclusters , 0, |
| 381 | mclmeta_ctor, mclmeta_dtor, NULL, |
| 382 | objcache_malloc_alloc, objcache_malloc_free, &mclmeta_malloc_args); |
| 383 | mbufcluster_cache = objcache_create("mbuf + cluster", nmbclusters, 0, |
| 384 | mbufcluster_ctor, mbufcluster_dtor, NULL, |
| 385 | objcache_malloc_alloc, objcache_malloc_free, &mbuf_malloc_args); |
| 386 | mbufphdrcluster_cache = objcache_create("mbuf pkt hdr + cluster", |
| 387 | nmbclusters, 64, mbufphdrcluster_ctor, mbufcluster_dtor, NULL, |
| 388 | objcache_malloc_alloc, objcache_malloc_free, &mbuf_malloc_args); |
| 389 | return; |
| 390 | } |
| 391 | |
| 392 | /* |
| 393 | * Return the number of references to this mbuf's data. 0 is returned |
| 394 | * if the mbuf is not M_EXT, a reference count is returned if it is |
| 395 | * M_EXT | M_EXT_CLUSTER, and 99 is returned if it is a special M_EXT. |
| 396 | */ |
| 397 | int |
| 398 | m_sharecount(struct mbuf *m) |
| 399 | { |
| 400 | switch (m->m_flags & (M_EXT | M_EXT_CLUSTER)) { |
| 401 | case 0: |
| 402 | return (0); |
| 403 | case M_EXT: |
| 404 | return (99); |
| 405 | case M_EXT | M_EXT_CLUSTER: |
| 406 | return (((struct mbcluster *)m->m_ext.ext_arg)->mcl_refs); |
| 407 | } |
| 408 | /* NOTREACHED */ |
| 409 | return (0); /* to shut up compiler */ |
| 410 | } |
| 411 | |
| 412 | /* |
| 413 | * change mbuf to new type |
| 414 | */ |
| 415 | void |
| 416 | m_chtype(struct mbuf *m, int type) |
| 417 | { |
| 418 | crit_enter(); |
| 419 | ++mbtypes[type]; |
| 420 | --mbtypes[m->m_type]; |
| 421 | m->m_type = type; |
| 422 | crit_exit(); |
| 423 | } |
| 424 | |
| 425 | static void |
| 426 | m_reclaim(void) |
| 427 | { |
| 428 | struct domain *dp; |
| 429 | struct protosw *pr; |
| 430 | |
| 431 | crit_enter(); |
| 432 | SLIST_FOREACH(dp, &domains, dom_next) { |
| 433 | for (pr = dp->dom_protosw; pr < dp->dom_protoswNPROTOSW; pr++) { |
| 434 | if (pr->pr_drain) |
| 435 | (*pr->pr_drain)(); |
| 436 | } |
| 437 | } |
| 438 | crit_exit(); |
| 439 | mbstat.m_drain++; |
| 440 | } |
| 441 | |
| 442 | static void __inline |
| 443 | updatestats(struct mbuf *m, int type) |
| 444 | { |
| 445 | m->m_type = type; |
| 446 | |
| 447 | crit_enter(); |
| 448 | ++mbtypes[type]; |
| 449 | ++mbstat.m_mbufs; |
| 450 | crit_exit(); |
| 451 | } |
| 452 | |
| 453 | /* |
| 454 | * Allocate an mbuf. |
| 455 | */ |
| 456 | struct mbuf * |
| 457 | m_get(int how, int type) |
| 458 | { |
| 459 | struct mbuf *m; |
| 460 | int ntries = 0; |
| 461 | int ocf = MBTOM(how); |
| 462 | |
| 463 | retryonce: |
| 464 | |
| 465 | m = objcache_get(mbuf_cache, ocf); |
| 466 | |
| 467 | if (m == NULL) { |
| 468 | if ((how & MB_TRYWAIT) && ntries++ == 0) { |
| 469 | struct objcache *reclaimlist[] = { |
| 470 | mbufphdr_cache, |
| 471 | mbufcluster_cache, mbufphdrcluster_cache |
| 472 | }; |
| 473 | const int nreclaims = __arysize(reclaimlist); |
| 474 | |
| 475 | if (!objcache_reclaimlist(reclaimlist, nreclaims, ocf)) |
| 476 | m_reclaim(); |
| 477 | goto retryonce; |
| 478 | } |
| 479 | return (NULL); |
| 480 | } |
| 481 | |
| 482 | updatestats(m, type); |
| 483 | return (m); |
| 484 | } |
| 485 | |
| 486 | struct mbuf * |
| 487 | m_gethdr(int how, int type) |
| 488 | { |
| 489 | struct mbuf *m; |
| 490 | int ocf = MBTOM(how); |
| 491 | int ntries = 0; |
| 492 | |
| 493 | retryonce: |
| 494 | |
| 495 | m = objcache_get(mbufphdr_cache, ocf); |
| 496 | |
| 497 | if (m == NULL) { |
| 498 | if ((how & MB_TRYWAIT) && ntries++ == 0) { |
| 499 | struct objcache *reclaimlist[] = { |
| 500 | mbuf_cache, |
| 501 | mbufcluster_cache, mbufphdrcluster_cache |
| 502 | }; |
| 503 | const int nreclaims = __arysize(reclaimlist); |
| 504 | |
| 505 | if (!objcache_reclaimlist(reclaimlist, nreclaims, ocf)) |
| 506 | m_reclaim(); |
| 507 | goto retryonce; |
| 508 | } |
| 509 | return (NULL); |
| 510 | } |
| 511 | |
| 512 | updatestats(m, type); |
| 513 | return (m); |
| 514 | } |
| 515 | |
| 516 | /* |
| 517 | * Get a mbuf (not a mbuf cluster!) and zero it. |
| 518 | * Deprecated. |
| 519 | */ |
| 520 | struct mbuf * |
| 521 | m_getclr(int how, int type) |
| 522 | { |
| 523 | struct mbuf *m; |
| 524 | |
| 525 | m = m_get(how, type); |
| 526 | if (m != NULL) |
| 527 | bzero(m->m_data, MLEN); |
| 528 | return (m); |
| 529 | } |
| 530 | |
| 531 | /* |
| 532 | * Returns an mbuf with an attached cluster. |
| 533 | * Because many network drivers use this kind of buffers a lot, it is |
| 534 | * convenient to keep a small pool of free buffers of this kind. |
| 535 | * Even a small size such as 10 gives about 10% improvement in the |
| 536 | * forwarding rate in a bridge or router. |
| 537 | */ |
| 538 | struct mbuf * |
| 539 | m_getcl(int how, short type, int flags) |
| 540 | { |
| 541 | struct mbuf *m; |
| 542 | int ocflags = MBTOM(how); |
| 543 | int ntries = 0; |
| 544 | |
| 545 | retryonce: |
| 546 | |
| 547 | if (flags & M_PKTHDR) |
| 548 | m = objcache_get(mbufphdrcluster_cache, ocflags); |
| 549 | else |
| 550 | m = objcache_get(mbufcluster_cache, ocflags); |
| 551 | |
| 552 | if (m == NULL) { |
| 553 | if ((how & MB_TRYWAIT) && ntries++ == 0) { |
| 554 | struct objcache *reclaimlist[1]; |
| 555 | |
| 556 | if (flags & M_PKTHDR) |
| 557 | reclaimlist[0] = mbufcluster_cache; |
| 558 | else |
| 559 | reclaimlist[0] = mbufphdrcluster_cache; |
| 560 | if (!objcache_reclaimlist(reclaimlist, 1, ocflags)) |
| 561 | m_reclaim(); |
| 562 | goto retryonce; |
| 563 | } |
| 564 | return (NULL); |
| 565 | } |
| 566 | |
| 567 | m->m_type = type; |
| 568 | |
| 569 | crit_enter(); |
| 570 | ++mbtypes[type]; |
| 571 | ++mbstat.m_clusters; |
| 572 | crit_exit(); |
| 573 | return (m); |
| 574 | } |
| 575 | |
| 576 | /* |
| 577 | * Allocate chain of requested length. |
| 578 | */ |
| 579 | struct mbuf * |
| 580 | m_getc(int len, int how, int type) |
| 581 | { |
| 582 | struct mbuf *n, *nfirst = NULL, **ntail = &nfirst; |
| 583 | int nsize; |
| 584 | |
| 585 | while (len > 0) { |
| 586 | n = m_getl(len, how, type, 0, &nsize); |
| 587 | if (n == NULL) |
| 588 | goto failed; |
| 589 | n->m_len = 0; |
| 590 | *ntail = n; |
| 591 | ntail = &n->m_next; |
| 592 | len -= nsize; |
| 593 | } |
| 594 | return (nfirst); |
| 595 | |
| 596 | failed: |
| 597 | m_freem(nfirst); |
| 598 | return (NULL); |
| 599 | } |
| 600 | |
| 601 | /* |
| 602 | * Allocate len-worth of mbufs and/or mbuf clusters (whatever fits best) |
| 603 | * and return a pointer to the head of the allocated chain. If m0 is |
| 604 | * non-null, then we assume that it is a single mbuf or an mbuf chain to |
| 605 | * which we want len bytes worth of mbufs and/or clusters attached, and so |
| 606 | * if we succeed in allocating it, we will just return a pointer to m0. |
| 607 | * |
| 608 | * If we happen to fail at any point during the allocation, we will free |
| 609 | * up everything we have already allocated and return NULL. |
| 610 | * |
| 611 | * Deprecated. Use m_getc() and m_cat() instead. |
| 612 | */ |
| 613 | struct mbuf * |
| 614 | m_getm(struct mbuf *m0, int len, int type, int how) |
| 615 | { |
| 616 | struct mbuf *nfirst; |
| 617 | |
| 618 | nfirst = m_getc(len, how, type); |
| 619 | |
| 620 | if (m0 != NULL) { |
| 621 | m_last(m0)->m_next = nfirst; |
| 622 | return (m0); |
| 623 | } |
| 624 | |
| 625 | return (nfirst); |
| 626 | } |
| 627 | |
| 628 | /* |
| 629 | * Adds a cluster to a normal mbuf, M_EXT is set on success. |
| 630 | * Deprecated. Use m_getcl() instead. |
| 631 | */ |
| 632 | void |
| 633 | m_mclget(struct mbuf *m, int how) |
| 634 | { |
| 635 | struct mbcluster *mcl; |
| 636 | |
| 637 | KKASSERT((m->m_flags & M_EXT) == 0); |
| 638 | mcl = objcache_get(mclmeta_cache, MBTOM(how)); |
| 639 | if (mcl != NULL) { |
| 640 | linkcluster(m, mcl); |
| 641 | crit_enter(); |
| 642 | ++mbstat.m_clusters; |
| 643 | /* leave the m_mbufs count intact for original mbuf */ |
| 644 | crit_exit(); |
| 645 | } |
| 646 | } |
| 647 | |
| 648 | /* |
| 649 | * Updates to mbcluster must be MPSAFE. Only an entity which already has |
| 650 | * a reference to the cluster can ref it, so we are in no danger of |
| 651 | * racing an add with a subtract. But the operation must still be atomic |
| 652 | * since multiple entities may have a reference on the cluster. |
| 653 | * |
| 654 | * m_mclfree() is almost the same but it must contend with two entities |
| 655 | * freeing the cluster at the same time. If there is only one reference |
| 656 | * count we are the only entity referencing the cluster and no further |
| 657 | * locking is required. Otherwise we must protect against a race to 0 |
| 658 | * with the serializer. |
| 659 | */ |
| 660 | static void |
| 661 | m_mclref(void *arg) |
| 662 | { |
| 663 | struct mbcluster *mcl = arg; |
| 664 | |
| 665 | atomic_add_int(&mcl->mcl_refs, 1); |
| 666 | } |
| 667 | |
| 668 | static void |
| 669 | m_mclfree(void *arg) |
| 670 | { |
| 671 | struct mbcluster *mcl = arg; |
| 672 | |
| 673 | if (mcl->mcl_refs == 1) { |
| 674 | mcl->mcl_refs = 0; |
| 675 | objcache_put(mclmeta_cache, mcl); |
| 676 | } else { |
| 677 | lwkt_serialize_enter(&mcl->mcl_serializer); |
| 678 | if (mcl->mcl_refs > 1) { |
| 679 | atomic_subtract_int(&mcl->mcl_refs, 1); |
| 680 | lwkt_serialize_exit(&mcl->mcl_serializer); |
| 681 | } else { |
| 682 | lwkt_serialize_exit(&mcl->mcl_serializer); |
| 683 | KKASSERT(mcl->mcl_refs == 1); |
| 684 | mcl->mcl_refs = 0; |
| 685 | objcache_put(mclmeta_cache, mcl); |
| 686 | } |
| 687 | } |
| 688 | } |
| 689 | |
| 690 | extern void db_print_backtrace(void); |
| 691 | |
| 692 | /* |
| 693 | * Free a single mbuf and any associated external storage. The successor, |
| 694 | * if any, is returned. |
| 695 | * |
| 696 | * We do need to check non-first mbuf for m_aux, since some of existing |
| 697 | * code does not call M_PREPEND properly. |
| 698 | * (example: call to bpf_mtap from drivers) |
| 699 | */ |
| 700 | struct mbuf * |
| 701 | m_free(struct mbuf *m) |
| 702 | { |
| 703 | struct mbuf *n; |
| 704 | |
| 705 | KASSERT(m->m_type != MT_FREE, ("freeing free mbuf %p", m)); |
| 706 | --mbtypes[m->m_type]; |
| 707 | |
| 708 | n = m->m_next; |
| 709 | |
| 710 | /* |
| 711 | * Make sure the mbuf is in constructed state before returning it |
| 712 | * to the objcache. |
| 713 | */ |
| 714 | m->m_next = NULL; |
| 715 | #ifdef notyet |
| 716 | KKASSERT(m->m_nextpkt == NULL); |
| 717 | #else |
| 718 | if (m->m_nextpkt != NULL) { |
| 719 | #ifdef DDB |
| 720 | static int afewtimes = 10; |
| 721 | |
| 722 | if (afewtimes-- > 0) { |
| 723 | printf("mfree: m->m_nextpkt != NULL\n"); |
| 724 | db_print_backtrace(); |
| 725 | } |
| 726 | #endif |
| 727 | m->m_nextpkt = NULL; |
| 728 | } |
| 729 | #endif |
| 730 | if (m->m_flags & M_PKTHDR) { |
| 731 | m_tag_delete_chain(m); /* eliminate XXX JH */ |
| 732 | } |
| 733 | |
| 734 | m->m_flags &= (M_EXT | M_EXT_CLUSTER | M_CLCACHE | M_PHCACHE); |
| 735 | |
| 736 | /* |
| 737 | * Clean the M_PKTHDR state so we can return the mbuf to its original |
| 738 | * cache. This is based on the PHCACHE flag which tells us whether |
| 739 | * the mbuf was originally allocated out of a packet-header cache |
| 740 | * or a non-packet-header cache. |
| 741 | */ |
| 742 | if (m->m_flags & M_PHCACHE) { |
| 743 | m->m_flags |= M_PKTHDR; |
| 744 | m->m_pkthdr.rcvif = NULL; /* eliminate XXX JH */ |
| 745 | m->m_pkthdr.csum_flags = 0; /* eliminate XXX JH */ |
| 746 | m->m_pkthdr.fw_flags = 0; /* eliminate XXX JH */ |
| 747 | SLIST_INIT(&m->m_pkthdr.tags); |
| 748 | } |
| 749 | |
| 750 | /* |
| 751 | * Handle remaining flags combinations. M_CLCACHE tells us whether |
| 752 | * the mbuf was originally allocated from a cluster cache or not, |
| 753 | * and is totally separate from whether the mbuf is currently |
| 754 | * associated with a cluster. |
| 755 | */ |
| 756 | crit_enter(); |
| 757 | switch(m->m_flags & (M_CLCACHE | M_EXT | M_EXT_CLUSTER)) { |
| 758 | case M_CLCACHE | M_EXT | M_EXT_CLUSTER: |
| 759 | /* |
| 760 | * mbuf+cluster cache case. The mbuf was allocated from the |
| 761 | * combined mbuf_cluster cache and can be returned to the |
| 762 | * cache if the cluster hasn't been shared. |
| 763 | */ |
| 764 | if (m_sharecount(m) == 1) { |
| 765 | /* |
| 766 | * The cluster has not been shared, we can just |
| 767 | * reset the data pointer and return the mbuf |
| 768 | * to the cluster cache. Note that the reference |
| 769 | * count is left intact (it is still associated with |
| 770 | * an mbuf). |
| 771 | */ |
| 772 | m->m_data = m->m_ext.ext_buf; |
| 773 | if (m->m_flags & M_PHCACHE) |
| 774 | objcache_put(mbufphdrcluster_cache, m); |
| 775 | else |
| 776 | objcache_put(mbufcluster_cache, m); |
| 777 | --mbstat.m_clusters; |
| 778 | } else { |
| 779 | /* |
| 780 | * Hell. Someone else has a ref on this cluster, |
| 781 | * we have to disconnect it which means we can't |
| 782 | * put it back into the mbufcluster_cache, we |
| 783 | * have to destroy the mbuf. |
| 784 | * |
| 785 | * Other mbuf references to the cluster will typically |
| 786 | * be M_EXT | M_EXT_CLUSTER but without M_CLCACHE. |
| 787 | * |
| 788 | * XXX we could try to connect another cluster to |
| 789 | * it. |
| 790 | */ |
| 791 | m->m_ext.ext_free(m->m_ext.ext_arg); |
| 792 | m->m_flags &= ~(M_EXT | M_EXT_CLUSTER); |
| 793 | if (m->m_flags & M_PHCACHE) |
| 794 | objcache_dtor(mbufphdrcluster_cache, m); |
| 795 | else |
| 796 | objcache_dtor(mbufcluster_cache, m); |
| 797 | } |
| 798 | break; |
| 799 | case M_EXT | M_EXT_CLUSTER: |
| 800 | /* |
| 801 | * Normal cluster associated with an mbuf that was allocated |
| 802 | * from the normal mbuf pool rather then the cluster pool. |
| 803 | * The cluster has to be independantly disassociated from the |
| 804 | * mbuf. |
| 805 | */ |
| 806 | if (m_sharecount(m) == 1) |
| 807 | --mbstat.m_clusters; |
| 808 | /* fall through */ |
| 809 | case M_EXT: |
| 810 | /* |
| 811 | * Normal cluster association case, disconnect the cluster from |
| 812 | * the mbuf. The cluster may or may not be custom. |
| 813 | */ |
| 814 | m->m_ext.ext_free(m->m_ext.ext_arg); |
| 815 | m->m_flags &= ~(M_EXT | M_EXT_CLUSTER); |
| 816 | /* fall through */ |
| 817 | case 0: |
| 818 | /* |
| 819 | * return the mbuf to the mbuf cache. |
| 820 | */ |
| 821 | if (m->m_flags & M_PHCACHE) { |
| 822 | m->m_data = m->m_pktdat; |
| 823 | objcache_put(mbufphdr_cache, m); |
| 824 | } else { |
| 825 | m->m_data = m->m_dat; |
| 826 | objcache_put(mbuf_cache, m); |
| 827 | } |
| 828 | --mbstat.m_mbufs; |
| 829 | break; |
| 830 | default: |
| 831 | if (!panicstr) |
| 832 | panic("bad mbuf flags %p %08x\n", m, m->m_flags); |
| 833 | break; |
| 834 | } |
| 835 | crit_exit(); |
| 836 | return (n); |
| 837 | } |
| 838 | |
| 839 | void |
| 840 | m_freem(struct mbuf *m) |
| 841 | { |
| 842 | crit_enter(); |
| 843 | while (m) |
| 844 | m = m_free(m); |
| 845 | crit_exit(); |
| 846 | } |
| 847 | |
| 848 | /* |
| 849 | * mbuf utility routines |
| 850 | */ |
| 851 | |
| 852 | /* |
| 853 | * Lesser-used path for M_PREPEND: allocate new mbuf to prepend to chain and |
| 854 | * copy junk along. |
| 855 | */ |
| 856 | struct mbuf * |
| 857 | m_prepend(struct mbuf *m, int len, int how) |
| 858 | { |
| 859 | struct mbuf *mn; |
| 860 | |
| 861 | if (m->m_flags & M_PKTHDR) |
| 862 | mn = m_gethdr(how, m->m_type); |
| 863 | else |
| 864 | mn = m_get(how, m->m_type); |
| 865 | if (mn == NULL) { |
| 866 | m_freem(m); |
| 867 | return (NULL); |
| 868 | } |
| 869 | if (m->m_flags & M_PKTHDR) |
| 870 | M_MOVE_PKTHDR(mn, m); |
| 871 | mn->m_next = m; |
| 872 | m = mn; |
| 873 | if (len < MHLEN) |
| 874 | MH_ALIGN(m, len); |
| 875 | m->m_len = len; |
| 876 | return (m); |
| 877 | } |
| 878 | |
| 879 | /* |
| 880 | * Make a copy of an mbuf chain starting "off0" bytes from the beginning, |
| 881 | * continuing for "len" bytes. If len is M_COPYALL, copy to end of mbuf. |
| 882 | * The wait parameter is a choice of MB_WAIT/MB_DONTWAIT from caller. |
| 883 | * Note that the copy is read-only, because clusters are not copied, |
| 884 | * only their reference counts are incremented. |
| 885 | */ |
| 886 | struct mbuf * |
| 887 | m_copym(const struct mbuf *m, int off0, int len, int wait) |
| 888 | { |
| 889 | struct mbuf *n, **np; |
| 890 | int off = off0; |
| 891 | struct mbuf *top; |
| 892 | int copyhdr = 0; |
| 893 | |
| 894 | KASSERT(off >= 0, ("m_copym, negative off %d", off)); |
| 895 | KASSERT(len >= 0, ("m_copym, negative len %d", len)); |
| 896 | if (off == 0 && m->m_flags & M_PKTHDR) |
| 897 | copyhdr = 1; |
| 898 | while (off > 0) { |
| 899 | KASSERT(m != NULL, ("m_copym, offset > size of mbuf chain")); |
| 900 | if (off < m->m_len) |
| 901 | break; |
| 902 | off -= m->m_len; |
| 903 | m = m->m_next; |
| 904 | } |
| 905 | np = ⊤ |
| 906 | top = 0; |
| 907 | while (len > 0) { |
| 908 | if (m == NULL) { |
| 909 | KASSERT(len == M_COPYALL, |
| 910 | ("m_copym, length > size of mbuf chain")); |
| 911 | break; |
| 912 | } |
| 913 | /* |
| 914 | * Because we are sharing any cluster attachment below, |
| 915 | * be sure to get an mbuf that does not have a cluster |
| 916 | * associated with it. |
| 917 | */ |
| 918 | if (copyhdr) |
| 919 | n = m_gethdr(wait, m->m_type); |
| 920 | else |
| 921 | n = m_get(wait, m->m_type); |
| 922 | *np = n; |
| 923 | if (n == NULL) |
| 924 | goto nospace; |
| 925 | if (copyhdr) { |
| 926 | if (!m_dup_pkthdr(n, m, wait)) |
| 927 | goto nospace; |
| 928 | if (len == M_COPYALL) |
| 929 | n->m_pkthdr.len -= off0; |
| 930 | else |
| 931 | n->m_pkthdr.len = len; |
| 932 | copyhdr = 0; |
| 933 | } |
| 934 | n->m_len = min(len, m->m_len - off); |
| 935 | if (m->m_flags & M_EXT) { |
| 936 | KKASSERT((n->m_flags & M_EXT) == 0); |
| 937 | n->m_data = m->m_data + off; |
| 938 | m->m_ext.ext_ref(m->m_ext.ext_arg); |
| 939 | n->m_ext = m->m_ext; |
| 940 | n->m_flags |= m->m_flags & (M_EXT | M_EXT_CLUSTER); |
| 941 | } else { |
| 942 | bcopy(mtod(m, caddr_t)+off, mtod(n, caddr_t), |
| 943 | (unsigned)n->m_len); |
| 944 | } |
| 945 | if (len != M_COPYALL) |
| 946 | len -= n->m_len; |
| 947 | off = 0; |
| 948 | m = m->m_next; |
| 949 | np = &n->m_next; |
| 950 | } |
| 951 | if (top == NULL) |
| 952 | mbstat.m_mcfail++; |
| 953 | return (top); |
| 954 | nospace: |
| 955 | m_freem(top); |
| 956 | mbstat.m_mcfail++; |
| 957 | return (NULL); |
| 958 | } |
| 959 | |
| 960 | /* |
| 961 | * Copy an entire packet, including header (which must be present). |
| 962 | * An optimization of the common case `m_copym(m, 0, M_COPYALL, how)'. |
| 963 | * Note that the copy is read-only, because clusters are not copied, |
| 964 | * only their reference counts are incremented. |
| 965 | * Preserve alignment of the first mbuf so if the creator has left |
| 966 | * some room at the beginning (e.g. for inserting protocol headers) |
| 967 | * the copies also have the room available. |
| 968 | */ |
| 969 | struct mbuf * |
| 970 | m_copypacket(struct mbuf *m, int how) |
| 971 | { |
| 972 | struct mbuf *top, *n, *o; |
| 973 | |
| 974 | n = m_gethdr(how, m->m_type); |
| 975 | top = n; |
| 976 | if (!n) |
| 977 | goto nospace; |
| 978 | |
| 979 | if (!m_dup_pkthdr(n, m, how)) |
| 980 | goto nospace; |
| 981 | n->m_len = m->m_len; |
| 982 | if (m->m_flags & M_EXT) { |
| 983 | KKASSERT((n->m_flags & M_EXT) == 0); |
| 984 | n->m_data = m->m_data; |
| 985 | m->m_ext.ext_ref(m->m_ext.ext_arg); |
| 986 | n->m_ext = m->m_ext; |
| 987 | n->m_flags |= m->m_flags & (M_EXT | M_EXT_CLUSTER); |
| 988 | } else { |
| 989 | n->m_data = n->m_pktdat + (m->m_data - m->m_pktdat ); |
| 990 | bcopy(mtod(m, char *), mtod(n, char *), n->m_len); |
| 991 | } |
| 992 | |
| 993 | m = m->m_next; |
| 994 | while (m) { |
| 995 | o = m_get(how, m->m_type); |
| 996 | if (!o) |
| 997 | goto nospace; |
| 998 | |
| 999 | n->m_next = o; |
| 1000 | n = n->m_next; |
| 1001 | |
| 1002 | n->m_len = m->m_len; |
| 1003 | if (m->m_flags & M_EXT) { |
| 1004 | KKASSERT((n->m_flags & M_EXT) == 0); |
| 1005 | n->m_data = m->m_data; |
| 1006 | m->m_ext.ext_ref(m->m_ext.ext_arg); |
| 1007 | n->m_ext = m->m_ext; |
| 1008 | n->m_flags |= m->m_flags & (M_EXT | M_EXT_CLUSTER); |
| 1009 | } else { |
| 1010 | bcopy(mtod(m, char *), mtod(n, char *), n->m_len); |
| 1011 | } |
| 1012 | |
| 1013 | m = m->m_next; |
| 1014 | } |
| 1015 | return top; |
| 1016 | nospace: |
| 1017 | m_freem(top); |
| 1018 | mbstat.m_mcfail++; |
| 1019 | return (NULL); |
| 1020 | } |
| 1021 | |
| 1022 | /* |
| 1023 | * Copy data from an mbuf chain starting "off" bytes from the beginning, |
| 1024 | * continuing for "len" bytes, into the indicated buffer. |
| 1025 | */ |
| 1026 | void |
| 1027 | m_copydata(const struct mbuf *m, int off, int len, caddr_t cp) |
| 1028 | { |
| 1029 | unsigned count; |
| 1030 | |
| 1031 | KASSERT(off >= 0, ("m_copydata, negative off %d", off)); |
| 1032 | KASSERT(len >= 0, ("m_copydata, negative len %d", len)); |
| 1033 | while (off > 0) { |
| 1034 | KASSERT(m != NULL, ("m_copydata, offset > size of mbuf chain")); |
| 1035 | if (off < m->m_len) |
| 1036 | break; |
| 1037 | off -= m->m_len; |
| 1038 | m = m->m_next; |
| 1039 | } |
| 1040 | while (len > 0) { |
| 1041 | KASSERT(m != NULL, ("m_copydata, length > size of mbuf chain")); |
| 1042 | count = min(m->m_len - off, len); |
| 1043 | bcopy(mtod(m, caddr_t) + off, cp, count); |
| 1044 | len -= count; |
| 1045 | cp += count; |
| 1046 | off = 0; |
| 1047 | m = m->m_next; |
| 1048 | } |
| 1049 | } |
| 1050 | |
| 1051 | /* |
| 1052 | * Copy a packet header mbuf chain into a completely new chain, including |
| 1053 | * copying any mbuf clusters. Use this instead of m_copypacket() when |
| 1054 | * you need a writable copy of an mbuf chain. |
| 1055 | */ |
| 1056 | struct mbuf * |
| 1057 | m_dup(struct mbuf *m, int how) |
| 1058 | { |
| 1059 | struct mbuf **p, *top = NULL; |
| 1060 | int remain, moff, nsize; |
| 1061 | |
| 1062 | /* Sanity check */ |
| 1063 | if (m == NULL) |
| 1064 | return (NULL); |
| 1065 | KASSERT((m->m_flags & M_PKTHDR) != 0, ("%s: !PKTHDR", __func__)); |
| 1066 | |
| 1067 | /* While there's more data, get a new mbuf, tack it on, and fill it */ |
| 1068 | remain = m->m_pkthdr.len; |
| 1069 | moff = 0; |
| 1070 | p = ⊤ |
| 1071 | while (remain > 0 || top == NULL) { /* allow m->m_pkthdr.len == 0 */ |
| 1072 | struct mbuf *n; |
| 1073 | |
| 1074 | /* Get the next new mbuf */ |
| 1075 | n = m_getl(remain, how, m->m_type, top == NULL ? M_PKTHDR : 0, |
| 1076 | &nsize); |
| 1077 | if (n == NULL) |
| 1078 | goto nospace; |
| 1079 | if (top == NULL) |
| 1080 | if (!m_dup_pkthdr(n, m, how)) |
| 1081 | goto nospace0; |
| 1082 | |
| 1083 | /* Link it into the new chain */ |
| 1084 | *p = n; |
| 1085 | p = &n->m_next; |
| 1086 | |
| 1087 | /* Copy data from original mbuf(s) into new mbuf */ |
| 1088 | n->m_len = 0; |
| 1089 | while (n->m_len < nsize && m != NULL) { |
| 1090 | int chunk = min(nsize - n->m_len, m->m_len - moff); |
| 1091 | |
| 1092 | bcopy(m->m_data + moff, n->m_data + n->m_len, chunk); |
| 1093 | moff += chunk; |
| 1094 | n->m_len += chunk; |
| 1095 | remain -= chunk; |
| 1096 | if (moff == m->m_len) { |
| 1097 | m = m->m_next; |
| 1098 | moff = 0; |
| 1099 | } |
| 1100 | } |
| 1101 | |
| 1102 | /* Check correct total mbuf length */ |
| 1103 | KASSERT((remain > 0 && m != NULL) || (remain == 0 && m == NULL), |
| 1104 | ("%s: bogus m_pkthdr.len", __func__)); |
| 1105 | } |
| 1106 | return (top); |
| 1107 | |
| 1108 | nospace: |
| 1109 | m_freem(top); |
| 1110 | nospace0: |
| 1111 | mbstat.m_mcfail++; |
| 1112 | return (NULL); |
| 1113 | } |
| 1114 | |
| 1115 | /* |
| 1116 | * Concatenate mbuf chain n to m. |
| 1117 | * Both chains must be of the same type (e.g. MT_DATA). |
| 1118 | * Any m_pkthdr is not updated. |
| 1119 | */ |
| 1120 | void |
| 1121 | m_cat(struct mbuf *m, struct mbuf *n) |
| 1122 | { |
| 1123 | m = m_last(m); |
| 1124 | while (n) { |
| 1125 | if (m->m_flags & M_EXT || |
| 1126 | m->m_data + m->m_len + n->m_len >= &m->m_dat[MLEN]) { |
| 1127 | /* just join the two chains */ |
| 1128 | m->m_next = n; |
| 1129 | return; |
| 1130 | } |
| 1131 | /* splat the data from one into the other */ |
| 1132 | bcopy(mtod(n, caddr_t), mtod(m, caddr_t) + m->m_len, |
| 1133 | (u_int)n->m_len); |
| 1134 | m->m_len += n->m_len; |
| 1135 | n = m_free(n); |
| 1136 | } |
| 1137 | } |
| 1138 | |
| 1139 | void |
| 1140 | m_adj(struct mbuf *mp, int req_len) |
| 1141 | { |
| 1142 | int len = req_len; |
| 1143 | struct mbuf *m; |
| 1144 | int count; |
| 1145 | |
| 1146 | if ((m = mp) == NULL) |
| 1147 | return; |
| 1148 | if (len >= 0) { |
| 1149 | /* |
| 1150 | * Trim from head. |
| 1151 | */ |
| 1152 | while (m != NULL && len > 0) { |
| 1153 | if (m->m_len <= len) { |
| 1154 | len -= m->m_len; |
| 1155 | m->m_len = 0; |
| 1156 | m = m->m_next; |
| 1157 | } else { |
| 1158 | m->m_len -= len; |
| 1159 | m->m_data += len; |
| 1160 | len = 0; |
| 1161 | } |
| 1162 | } |
| 1163 | m = mp; |
| 1164 | if (mp->m_flags & M_PKTHDR) |
| 1165 | m->m_pkthdr.len -= (req_len - len); |
| 1166 | } else { |
| 1167 | /* |
| 1168 | * Trim from tail. Scan the mbuf chain, |
| 1169 | * calculating its length and finding the last mbuf. |
| 1170 | * If the adjustment only affects this mbuf, then just |
| 1171 | * adjust and return. Otherwise, rescan and truncate |
| 1172 | * after the remaining size. |
| 1173 | */ |
| 1174 | len = -len; |
| 1175 | count = 0; |
| 1176 | for (;;) { |
| 1177 | count += m->m_len; |
| 1178 | if (m->m_next == (struct mbuf *)0) |
| 1179 | break; |
| 1180 | m = m->m_next; |
| 1181 | } |
| 1182 | if (m->m_len >= len) { |
| 1183 | m->m_len -= len; |
| 1184 | if (mp->m_flags & M_PKTHDR) |
| 1185 | mp->m_pkthdr.len -= len; |
| 1186 | return; |
| 1187 | } |
| 1188 | count -= len; |
| 1189 | if (count < 0) |
| 1190 | count = 0; |
| 1191 | /* |
| 1192 | * Correct length for chain is "count". |
| 1193 | * Find the mbuf with last data, adjust its length, |
| 1194 | * and toss data from remaining mbufs on chain. |
| 1195 | */ |
| 1196 | m = mp; |
| 1197 | if (m->m_flags & M_PKTHDR) |
| 1198 | m->m_pkthdr.len = count; |
| 1199 | for (; m; m = m->m_next) { |
| 1200 | if (m->m_len >= count) { |
| 1201 | m->m_len = count; |
| 1202 | break; |
| 1203 | } |
| 1204 | count -= m->m_len; |
| 1205 | } |
| 1206 | while (m->m_next) |
| 1207 | (m = m->m_next) ->m_len = 0; |
| 1208 | } |
| 1209 | } |
| 1210 | |
| 1211 | /* |
| 1212 | * Rearrange an mbuf chain so that len bytes are contiguous |
| 1213 | * and in the data area of an mbuf (so that mtod will work for a structure |
| 1214 | * of size len). Returns the resulting mbuf chain on success, frees it and |
| 1215 | * returns null on failure. If there is room, it will add up to |
| 1216 | * max_protohdr-len extra bytes to the contiguous region in an attempt to |
| 1217 | * avoid being called next time. |
| 1218 | */ |
| 1219 | struct mbuf * |
| 1220 | m_pullup(struct mbuf *n, int len) |
| 1221 | { |
| 1222 | struct mbuf *m; |
| 1223 | int count; |
| 1224 | int space; |
| 1225 | |
| 1226 | /* |
| 1227 | * If first mbuf has no cluster, and has room for len bytes |
| 1228 | * without shifting current data, pullup into it, |
| 1229 | * otherwise allocate a new mbuf to prepend to the chain. |
| 1230 | */ |
| 1231 | if (!(n->m_flags & M_EXT) && |
| 1232 | n->m_data + len < &n->m_dat[MLEN] && |
| 1233 | n->m_next) { |
| 1234 | if (n->m_len >= len) |
| 1235 | return (n); |
| 1236 | m = n; |
| 1237 | n = n->m_next; |
| 1238 | len -= m->m_len; |
| 1239 | } else { |
| 1240 | if (len > MHLEN) |
| 1241 | goto bad; |
| 1242 | if (n->m_flags & M_PKTHDR) |
| 1243 | m = m_gethdr(MB_DONTWAIT, n->m_type); |
| 1244 | else |
| 1245 | m = m_get(MB_DONTWAIT, n->m_type); |
| 1246 | if (m == NULL) |
| 1247 | goto bad; |
| 1248 | m->m_len = 0; |
| 1249 | if (n->m_flags & M_PKTHDR) |
| 1250 | M_MOVE_PKTHDR(m, n); |
| 1251 | } |
| 1252 | space = &m->m_dat[MLEN] - (m->m_data + m->m_len); |
| 1253 | do { |
| 1254 | count = min(min(max(len, max_protohdr), space), n->m_len); |
| 1255 | bcopy(mtod(n, caddr_t), mtod(m, caddr_t) + m->m_len, |
| 1256 | (unsigned)count); |
| 1257 | len -= count; |
| 1258 | m->m_len += count; |
| 1259 | n->m_len -= count; |
| 1260 | space -= count; |
| 1261 | if (n->m_len) |
| 1262 | n->m_data += count; |
| 1263 | else |
| 1264 | n = m_free(n); |
| 1265 | } while (len > 0 && n); |
| 1266 | if (len > 0) { |
| 1267 | m_free(m); |
| 1268 | goto bad; |
| 1269 | } |
| 1270 | m->m_next = n; |
| 1271 | return (m); |
| 1272 | bad: |
| 1273 | m_freem(n); |
| 1274 | mbstat.m_mpfail++; |
| 1275 | return (NULL); |
| 1276 | } |
| 1277 | |
| 1278 | /* |
| 1279 | * Partition an mbuf chain in two pieces, returning the tail -- |
| 1280 | * all but the first len0 bytes. In case of failure, it returns NULL and |
| 1281 | * attempts to restore the chain to its original state. |
| 1282 | * |
| 1283 | * Note that the resulting mbufs might be read-only, because the new |
| 1284 | * mbuf can end up sharing an mbuf cluster with the original mbuf if |
| 1285 | * the "breaking point" happens to lie within a cluster mbuf. Use the |
| 1286 | * M_WRITABLE() macro to check for this case. |
| 1287 | */ |
| 1288 | struct mbuf * |
| 1289 | m_split(struct mbuf *m0, int len0, int wait) |
| 1290 | { |
| 1291 | struct mbuf *m, *n; |
| 1292 | unsigned len = len0, remain; |
| 1293 | |
| 1294 | for (m = m0; m && len > m->m_len; m = m->m_next) |
| 1295 | len -= m->m_len; |
| 1296 | if (m == NULL) |
| 1297 | return (NULL); |
| 1298 | remain = m->m_len - len; |
| 1299 | if (m0->m_flags & M_PKTHDR) { |
| 1300 | n = m_gethdr(wait, m0->m_type); |
| 1301 | if (n == NULL) |
| 1302 | return (NULL); |
| 1303 | n->m_pkthdr.rcvif = m0->m_pkthdr.rcvif; |
| 1304 | n->m_pkthdr.len = m0->m_pkthdr.len - len0; |
| 1305 | m0->m_pkthdr.len = len0; |
| 1306 | if (m->m_flags & M_EXT) |
| 1307 | goto extpacket; |
| 1308 | if (remain > MHLEN) { |
| 1309 | /* m can't be the lead packet */ |
| 1310 | MH_ALIGN(n, 0); |
| 1311 | n->m_next = m_split(m, len, wait); |
| 1312 | if (n->m_next == NULL) { |
| 1313 | m_free(n); |
| 1314 | return (NULL); |
| 1315 | } else { |
| 1316 | n->m_len = 0; |
| 1317 | return (n); |
| 1318 | } |
| 1319 | } else |
| 1320 | MH_ALIGN(n, remain); |
| 1321 | } else if (remain == 0) { |
| 1322 | n = m->m_next; |
| 1323 | m->m_next = 0; |
| 1324 | return (n); |
| 1325 | } else { |
| 1326 | n = m_get(wait, m->m_type); |
| 1327 | if (n == NULL) |
| 1328 | return (NULL); |
| 1329 | M_ALIGN(n, remain); |
| 1330 | } |
| 1331 | extpacket: |
| 1332 | if (m->m_flags & M_EXT) { |
| 1333 | KKASSERT((n->m_flags & M_EXT) == 0); |
| 1334 | n->m_data = m->m_data + len; |
| 1335 | m->m_ext.ext_ref(m->m_ext.ext_arg); |
| 1336 | n->m_ext = m->m_ext; |
| 1337 | n->m_flags |= m->m_flags & (M_EXT | M_EXT_CLUSTER); |
| 1338 | } else { |
| 1339 | bcopy(mtod(m, caddr_t) + len, mtod(n, caddr_t), remain); |
| 1340 | } |
| 1341 | n->m_len = remain; |
| 1342 | m->m_len = len; |
| 1343 | n->m_next = m->m_next; |
| 1344 | m->m_next = 0; |
| 1345 | return (n); |
| 1346 | } |
| 1347 | |
| 1348 | /* |
| 1349 | * Routine to copy from device local memory into mbufs. |
| 1350 | * Note: "offset" is ill-defined and always called as 0, so ignore it. |
| 1351 | */ |
| 1352 | struct mbuf * |
| 1353 | m_devget(char *buf, int len, int offset, struct ifnet *ifp, |
| 1354 | void (*copy)(volatile const void *from, volatile void *to, size_t length)) |
| 1355 | { |
| 1356 | struct mbuf *m, *mfirst = NULL, **mtail; |
| 1357 | int nsize, flags; |
| 1358 | |
| 1359 | if (copy == NULL) |
| 1360 | copy = bcopy; |
| 1361 | mtail = &mfirst; |
| 1362 | flags = M_PKTHDR; |
| 1363 | |
| 1364 | while (len > 0) { |
| 1365 | m = m_getl(len, MB_DONTWAIT, MT_DATA, flags, &nsize); |
| 1366 | if (m == NULL) { |
| 1367 | m_freem(mfirst); |
| 1368 | return (NULL); |
| 1369 | } |
| 1370 | m->m_len = min(len, nsize); |
| 1371 | |
| 1372 | if (flags & M_PKTHDR) { |
| 1373 | if (len + max_linkhdr <= nsize) |
| 1374 | m->m_data += max_linkhdr; |
| 1375 | m->m_pkthdr.rcvif = ifp; |
| 1376 | m->m_pkthdr.len = len; |
| 1377 | flags = 0; |
| 1378 | } |
| 1379 | |
| 1380 | copy(buf, m->m_data, (unsigned)m->m_len); |
| 1381 | buf += m->m_len; |
| 1382 | len -= m->m_len; |
| 1383 | *mtail = m; |
| 1384 | mtail = &m->m_next; |
| 1385 | } |
| 1386 | |
| 1387 | return (mfirst); |
| 1388 | } |
| 1389 | |
| 1390 | /* |
| 1391 | * Copy data from a buffer back into the indicated mbuf chain, |
| 1392 | * starting "off" bytes from the beginning, extending the mbuf |
| 1393 | * chain if necessary. |
| 1394 | */ |
| 1395 | void |
| 1396 | m_copyback(struct mbuf *m0, int off, int len, caddr_t cp) |
| 1397 | { |
| 1398 | int mlen; |
| 1399 | struct mbuf *m = m0, *n; |
| 1400 | int totlen = 0; |
| 1401 | |
| 1402 | if (m0 == NULL) |
| 1403 | return; |
| 1404 | while (off > (mlen = m->m_len)) { |
| 1405 | off -= mlen; |
| 1406 | totlen += mlen; |
| 1407 | if (m->m_next == NULL) { |
| 1408 | n = m_getclr(MB_DONTWAIT, m->m_type); |
| 1409 | if (n == NULL) |
| 1410 | goto out; |
| 1411 | n->m_len = min(MLEN, len + off); |
| 1412 | m->m_next = n; |
| 1413 | } |
| 1414 | m = m->m_next; |
| 1415 | } |
| 1416 | while (len > 0) { |
| 1417 | mlen = min (m->m_len - off, len); |
| 1418 | bcopy(cp, off + mtod(m, caddr_t), (unsigned)mlen); |
| 1419 | cp += mlen; |
| 1420 | len -= mlen; |
| 1421 | mlen += off; |
| 1422 | off = 0; |
| 1423 | totlen += mlen; |
| 1424 | if (len == 0) |
| 1425 | break; |
| 1426 | if (m->m_next == NULL) { |
| 1427 | n = m_get(MB_DONTWAIT, m->m_type); |
| 1428 | if (n == NULL) |
| 1429 | break; |
| 1430 | n->m_len = min(MLEN, len); |
| 1431 | m->m_next = n; |
| 1432 | } |
| 1433 | m = m->m_next; |
| 1434 | } |
| 1435 | out: if (((m = m0)->m_flags & M_PKTHDR) && (m->m_pkthdr.len < totlen)) |
| 1436 | m->m_pkthdr.len = totlen; |
| 1437 | } |
| 1438 | |
| 1439 | void |
| 1440 | m_print(const struct mbuf *m) |
| 1441 | { |
| 1442 | int len; |
| 1443 | const struct mbuf *m2; |
| 1444 | |
| 1445 | len = m->m_pkthdr.len; |
| 1446 | m2 = m; |
| 1447 | while (len) { |
| 1448 | printf("%p %*D\n", m2, m2->m_len, (u_char *)m2->m_data, "-"); |
| 1449 | len -= m2->m_len; |
| 1450 | m2 = m2->m_next; |
| 1451 | } |
| 1452 | return; |
| 1453 | } |
| 1454 | |
| 1455 | /* |
| 1456 | * "Move" mbuf pkthdr from "from" to "to". |
| 1457 | * "from" must have M_PKTHDR set, and "to" must be empty. |
| 1458 | */ |
| 1459 | void |
| 1460 | m_move_pkthdr(struct mbuf *to, struct mbuf *from) |
| 1461 | { |
| 1462 | KASSERT((to->m_flags & M_PKTHDR), ("m_move_pkthdr: not packet header")); |
| 1463 | |
| 1464 | to->m_flags |= from->m_flags & M_COPYFLAGS; |
| 1465 | to->m_pkthdr = from->m_pkthdr; /* especially tags */ |
| 1466 | SLIST_INIT(&from->m_pkthdr.tags); /* purge tags from src */ |
| 1467 | } |
| 1468 | |
| 1469 | /* |
| 1470 | * Duplicate "from"'s mbuf pkthdr in "to". |
| 1471 | * "from" must have M_PKTHDR set, and "to" must be empty. |
| 1472 | * In particular, this does a deep copy of the packet tags. |
| 1473 | */ |
| 1474 | int |
| 1475 | m_dup_pkthdr(struct mbuf *to, const struct mbuf *from, int how) |
| 1476 | { |
| 1477 | KASSERT((to->m_flags & M_PKTHDR), ("m_dup_pkthdr: not packet header")); |
| 1478 | |
| 1479 | to->m_flags = (from->m_flags & M_COPYFLAGS) | |
| 1480 | (to->m_flags & ~M_COPYFLAGS); |
| 1481 | to->m_pkthdr = from->m_pkthdr; |
| 1482 | SLIST_INIT(&to->m_pkthdr.tags); |
| 1483 | return (m_tag_copy_chain(to, from, how)); |
| 1484 | } |
| 1485 | |
| 1486 | /* |
| 1487 | * Defragment a mbuf chain, returning the shortest possible |
| 1488 | * chain of mbufs and clusters. If allocation fails and |
| 1489 | * this cannot be completed, NULL will be returned, but |
| 1490 | * the passed in chain will be unchanged. Upon success, |
| 1491 | * the original chain will be freed, and the new chain |
| 1492 | * will be returned. |
| 1493 | * |
| 1494 | * If a non-packet header is passed in, the original |
| 1495 | * mbuf (chain?) will be returned unharmed. |
| 1496 | * |
| 1497 | * m_defrag_nofree doesn't free the passed in mbuf. |
| 1498 | */ |
| 1499 | struct mbuf * |
| 1500 | m_defrag(struct mbuf *m0, int how) |
| 1501 | { |
| 1502 | struct mbuf *m_new; |
| 1503 | |
| 1504 | if ((m_new = m_defrag_nofree(m0, how)) == NULL) |
| 1505 | return (NULL); |
| 1506 | if (m_new != m0) |
| 1507 | m_freem(m0); |
| 1508 | return (m_new); |
| 1509 | } |
| 1510 | |
| 1511 | struct mbuf * |
| 1512 | m_defrag_nofree(struct mbuf *m0, int how) |
| 1513 | { |
| 1514 | struct mbuf *m_new = NULL, *m_final = NULL; |
| 1515 | int progress = 0, length, nsize; |
| 1516 | |
| 1517 | if (!(m0->m_flags & M_PKTHDR)) |
| 1518 | return (m0); |
| 1519 | |
| 1520 | #ifdef MBUF_STRESS_TEST |
| 1521 | if (m_defragrandomfailures) { |
| 1522 | int temp = karc4random() & 0xff; |
| 1523 | if (temp == 0xba) |
| 1524 | goto nospace; |
| 1525 | } |
| 1526 | #endif |
| 1527 | |
| 1528 | m_final = m_getl(m0->m_pkthdr.len, how, MT_DATA, M_PKTHDR, &nsize); |
| 1529 | if (m_final == NULL) |
| 1530 | goto nospace; |
| 1531 | m_final->m_len = 0; /* in case m0->m_pkthdr.len is zero */ |
| 1532 | |
| 1533 | if (m_dup_pkthdr(m_final, m0, how) == NULL) |
| 1534 | goto nospace; |
| 1535 | |
| 1536 | m_new = m_final; |
| 1537 | |
| 1538 | while (progress < m0->m_pkthdr.len) { |
| 1539 | length = m0->m_pkthdr.len - progress; |
| 1540 | if (length > MCLBYTES) |
| 1541 | length = MCLBYTES; |
| 1542 | |
| 1543 | if (m_new == NULL) { |
| 1544 | m_new = m_getl(length, how, MT_DATA, 0, &nsize); |
| 1545 | if (m_new == NULL) |
| 1546 | goto nospace; |
| 1547 | } |
| 1548 | |
| 1549 | m_copydata(m0, progress, length, mtod(m_new, caddr_t)); |
| 1550 | progress += length; |
| 1551 | m_new->m_len = length; |
| 1552 | if (m_new != m_final) |
| 1553 | m_cat(m_final, m_new); |
| 1554 | m_new = NULL; |
| 1555 | } |
| 1556 | if (m0->m_next == NULL) |
| 1557 | m_defraguseless++; |
| 1558 | m_defragpackets++; |
| 1559 | m_defragbytes += m_final->m_pkthdr.len; |
| 1560 | return (m_final); |
| 1561 | nospace: |
| 1562 | m_defragfailure++; |
| 1563 | if (m_new) |
| 1564 | m_free(m_new); |
| 1565 | m_freem(m_final); |
| 1566 | return (NULL); |
| 1567 | } |
| 1568 | |
| 1569 | /* |
| 1570 | * Move data from uio into mbufs. |
| 1571 | */ |
| 1572 | struct mbuf * |
| 1573 | m_uiomove(struct uio *uio) |
| 1574 | { |
| 1575 | struct mbuf *m; /* current working mbuf */ |
| 1576 | struct mbuf *head = NULL; /* result mbuf chain */ |
| 1577 | struct mbuf **mp = &head; |
| 1578 | int resid = uio->uio_resid, nsize, flags = M_PKTHDR, error; |
| 1579 | |
| 1580 | do { |
| 1581 | m = m_getl(resid, MB_WAIT, MT_DATA, flags, &nsize); |
| 1582 | if (flags) { |
| 1583 | m->m_pkthdr.len = 0; |
| 1584 | /* Leave room for protocol headers. */ |
| 1585 | if (resid < MHLEN) |
| 1586 | MH_ALIGN(m, resid); |
| 1587 | flags = 0; |
| 1588 | } |
| 1589 | m->m_len = min(nsize, resid); |
| 1590 | error = uiomove(mtod(m, caddr_t), m->m_len, uio); |
| 1591 | if (error) { |
| 1592 | m_free(m); |
| 1593 | goto failed; |
| 1594 | } |
| 1595 | *mp = m; |
| 1596 | mp = &m->m_next; |
| 1597 | head->m_pkthdr.len += m->m_len; |
| 1598 | resid -= m->m_len; |
| 1599 | } while (resid > 0); |
| 1600 | |
| 1601 | return (head); |
| 1602 | |
| 1603 | failed: |
| 1604 | m_freem(head); |
| 1605 | return (NULL); |
| 1606 | } |
| 1607 | |
| 1608 | struct mbuf * |
| 1609 | m_last(struct mbuf *m) |
| 1610 | { |
| 1611 | while (m->m_next) |
| 1612 | m = m->m_next; |
| 1613 | return (m); |
| 1614 | } |
| 1615 | |
| 1616 | /* |
| 1617 | * Return the number of bytes in an mbuf chain. |
| 1618 | * If lastm is not NULL, also return the last mbuf. |
| 1619 | */ |
| 1620 | u_int |
| 1621 | m_lengthm(struct mbuf *m, struct mbuf **lastm) |
| 1622 | { |
| 1623 | u_int len = 0; |
| 1624 | struct mbuf *prev = m; |
| 1625 | |
| 1626 | while (m) { |
| 1627 | len += m->m_len; |
| 1628 | prev = m; |
| 1629 | m = m->m_next; |
| 1630 | } |
| 1631 | if (lastm != NULL) |
| 1632 | *lastm = prev; |
| 1633 | return (len); |
| 1634 | } |
| 1635 | |
| 1636 | /* |
| 1637 | * Like m_lengthm(), except also keep track of mbuf usage. |
| 1638 | */ |
| 1639 | u_int |
| 1640 | m_countm(struct mbuf *m, struct mbuf **lastm, u_int *pmbcnt) |
| 1641 | { |
| 1642 | u_int len = 0, mbcnt = 0; |
| 1643 | struct mbuf *prev = m; |
| 1644 | |
| 1645 | while (m) { |
| 1646 | len += m->m_len; |
| 1647 | mbcnt += MSIZE; |
| 1648 | if (m->m_flags & M_EXT) |
| 1649 | mbcnt += m->m_ext.ext_size; |
| 1650 | prev = m; |
| 1651 | m = m->m_next; |
| 1652 | } |
| 1653 | if (lastm != NULL) |
| 1654 | *lastm = prev; |
| 1655 | *pmbcnt = mbcnt; |
| 1656 | return (len); |
| 1657 | } |