Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_mbuf.c
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1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2004, 2005, 5 * Bosko Milekic <bmilekic@FreeBSD.org>. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice unmodified, this list of conditions and the following 12 * 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 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30 #include <sys/cdefs.h> 31 __FBSDID("$FreeBSD$"); 32 33 #include "opt_param.h" 34 #include "opt_kern_tls.h" 35 36 #include <sys/param.h> 37 #include <sys/conf.h> 38 #include <sys/domainset.h> 39 #include <sys/malloc.h> 40 #include <sys/systm.h> 41 #include <sys/mbuf.h> 42 #include <sys/eventhandler.h> 43 #include <sys/kernel.h> 44 #include <sys/ktls.h> 45 #include <sys/limits.h> 46 #include <sys/lock.h> 47 #include <sys/mutex.h> 48 #include <sys/refcount.h> 49 #include <sys/sf_buf.h> 50 #include <sys/smp.h> 51 #include <sys/socket.h> 52 #include <sys/sysctl.h> 53 54 #include <net/if.h> 55 #include <net/if_var.h> 56 57 #include <vm/vm.h> 58 #include <vm/vm_extern.h> 59 #include <vm/vm_kern.h> 60 #include <vm/vm_page.h> 61 #include <vm/vm_pageout.h> 62 #include <vm/vm_map.h> 63 #include <vm/uma.h> 64 #include <vm/uma_dbg.h> 65 66 _Static_assert(MJUMPAGESIZE > MCLBYTES, 67 "Cluster must be smaller than a jumbo page"); 68 69 /* 70 * In FreeBSD, Mbufs and Mbuf Clusters are allocated from UMA 71 * Zones. 72 * 73 * Mbuf Clusters (2K, contiguous) are allocated from the Cluster 74 * Zone. The Zone can be capped at kern.ipc.nmbclusters, if the 75 * administrator so desires. 76 * 77 * Mbufs are allocated from a UMA Primary Zone called the Mbuf 78 * Zone. 79 * 80 * Additionally, FreeBSD provides a Packet Zone, which it 81 * configures as a Secondary Zone to the Mbuf Primary Zone, 82 * thus sharing backend Slab kegs with the Mbuf Primary Zone. 83 * 84 * Thus common-case allocations and locking are simplified: 85 * 86 * m_clget() m_getcl() 87 * | | 88 * | .------------>[(Packet Cache)] m_get(), m_gethdr() 89 * | | [ Packet ] | 90 * [(Cluster Cache)] [ Secondary ] [ (Mbuf Cache) ] 91 * [ Cluster Zone ] [ Zone ] [ Mbuf Primary Zone ] 92 * | \________ | 93 * [ Cluster Keg ] \ / 94 * | [ Mbuf Keg ] 95 * [ Cluster Slabs ] | 96 * | [ Mbuf Slabs ] 97 * \____________(VM)_________________/ 98 * 99 * 100 * Whenever an object is allocated with uma_zalloc() out of 101 * one of the Zones its _ctor_ function is executed. The same 102 * for any deallocation through uma_zfree() the _dtor_ function 103 * is executed. 104 * 105 * Caches are per-CPU and are filled from the Primary Zone. 106 * 107 * Whenever an object is allocated from the underlying global 108 * memory pool it gets pre-initialized with the _zinit_ functions. 109 * When the Keg's are overfull objects get decommissioned with 110 * _zfini_ functions and free'd back to the global memory pool. 111 * 112 */ 113 114 int nmbufs; /* limits number of mbufs */ 115 int nmbclusters; /* limits number of mbuf clusters */ 116 int nmbjumbop; /* limits number of page size jumbo clusters */ 117 int nmbjumbo9; /* limits number of 9k jumbo clusters */ 118 int nmbjumbo16; /* limits number of 16k jumbo clusters */ 119 120 bool mb_use_ext_pgs = false; /* use M_EXTPG mbufs for sendfile & TLS */ 121 122 static int 123 sysctl_mb_use_ext_pgs(SYSCTL_HANDLER_ARGS) 124 { 125 int error, extpg; 126 127 extpg = mb_use_ext_pgs; 128 error = sysctl_handle_int(oidp, &extpg, 0, req); 129 if (error == 0 && req->newptr != NULL) { 130 if (extpg != 0 && !PMAP_HAS_DMAP) 131 error = EOPNOTSUPP; 132 else 133 mb_use_ext_pgs = extpg != 0; 134 } 135 return (error); 136 } 137 SYSCTL_PROC(_kern_ipc, OID_AUTO, mb_use_ext_pgs, CTLTYPE_INT | CTLFLAG_RW, 138 &mb_use_ext_pgs, 0, 139 sysctl_mb_use_ext_pgs, "IU", 140 "Use unmapped mbufs for sendfile(2) and TLS offload"); 141 142 static quad_t maxmbufmem; /* overall real memory limit for all mbufs */ 143 144 SYSCTL_QUAD(_kern_ipc, OID_AUTO, maxmbufmem, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &maxmbufmem, 0, 145 "Maximum real memory allocatable to various mbuf types"); 146 147 static counter_u64_t snd_tag_count; 148 SYSCTL_COUNTER_U64(_kern_ipc, OID_AUTO, num_snd_tags, CTLFLAG_RW, 149 &snd_tag_count, "# of active mbuf send tags"); 150 151 /* 152 * tunable_mbinit() has to be run before any mbuf allocations are done. 153 */ 154 static void 155 tunable_mbinit(void *dummy) 156 { 157 quad_t realmem; 158 int extpg; 159 160 /* 161 * The default limit for all mbuf related memory is 1/2 of all 162 * available kernel memory (physical or kmem). 163 * At most it can be 3/4 of available kernel memory. 164 */ 165 realmem = qmin((quad_t)physmem * PAGE_SIZE, vm_kmem_size); 166 maxmbufmem = realmem / 2; 167 TUNABLE_QUAD_FETCH("kern.ipc.maxmbufmem", &maxmbufmem); 168 if (maxmbufmem > realmem / 4 * 3) 169 maxmbufmem = realmem / 4 * 3; 170 171 TUNABLE_INT_FETCH("kern.ipc.nmbclusters", &nmbclusters); 172 if (nmbclusters == 0) 173 nmbclusters = maxmbufmem / MCLBYTES / 4; 174 175 TUNABLE_INT_FETCH("kern.ipc.nmbjumbop", &nmbjumbop); 176 if (nmbjumbop == 0) 177 nmbjumbop = maxmbufmem / MJUMPAGESIZE / 4; 178 179 TUNABLE_INT_FETCH("kern.ipc.nmbjumbo9", &nmbjumbo9); 180 if (nmbjumbo9 == 0) 181 nmbjumbo9 = maxmbufmem / MJUM9BYTES / 6; 182 183 TUNABLE_INT_FETCH("kern.ipc.nmbjumbo16", &nmbjumbo16); 184 if (nmbjumbo16 == 0) 185 nmbjumbo16 = maxmbufmem / MJUM16BYTES / 6; 186 187 /* 188 * We need at least as many mbufs as we have clusters of 189 * the various types added together. 190 */ 191 TUNABLE_INT_FETCH("kern.ipc.nmbufs", &nmbufs); 192 if (nmbufs < nmbclusters + nmbjumbop + nmbjumbo9 + nmbjumbo16) 193 nmbufs = lmax(maxmbufmem / MSIZE / 5, 194 nmbclusters + nmbjumbop + nmbjumbo9 + nmbjumbo16); 195 196 /* 197 * Unmapped mbufs can only safely be used on platforms with a direct 198 * map. 199 */ 200 if (PMAP_HAS_DMAP) { 201 extpg = 1; 202 TUNABLE_INT_FETCH("kern.ipc.mb_use_ext_pgs", &extpg); 203 mb_use_ext_pgs = extpg != 0; 204 } 205 } 206 SYSINIT(tunable_mbinit, SI_SUB_KMEM, SI_ORDER_MIDDLE, tunable_mbinit, NULL); 207 208 static int 209 sysctl_nmbclusters(SYSCTL_HANDLER_ARGS) 210 { 211 int error, newnmbclusters; 212 213 newnmbclusters = nmbclusters; 214 error = sysctl_handle_int(oidp, &newnmbclusters, 0, req); 215 if (error == 0 && req->newptr && newnmbclusters != nmbclusters) { 216 if (newnmbclusters > nmbclusters && 217 nmbufs >= nmbclusters + nmbjumbop + nmbjumbo9 + nmbjumbo16) { 218 nmbclusters = newnmbclusters; 219 nmbclusters = uma_zone_set_max(zone_clust, nmbclusters); 220 EVENTHANDLER_INVOKE(nmbclusters_change); 221 } else 222 error = EINVAL; 223 } 224 return (error); 225 } 226 SYSCTL_PROC(_kern_ipc, OID_AUTO, nmbclusters, 227 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, &nmbclusters, 0, 228 sysctl_nmbclusters, "IU", 229 "Maximum number of mbuf clusters allowed"); 230 231 static int 232 sysctl_nmbjumbop(SYSCTL_HANDLER_ARGS) 233 { 234 int error, newnmbjumbop; 235 236 newnmbjumbop = nmbjumbop; 237 error = sysctl_handle_int(oidp, &newnmbjumbop, 0, req); 238 if (error == 0 && req->newptr && newnmbjumbop != nmbjumbop) { 239 if (newnmbjumbop > nmbjumbop && 240 nmbufs >= nmbclusters + nmbjumbop + nmbjumbo9 + nmbjumbo16) { 241 nmbjumbop = newnmbjumbop; 242 nmbjumbop = uma_zone_set_max(zone_jumbop, nmbjumbop); 243 } else 244 error = EINVAL; 245 } 246 return (error); 247 } 248 SYSCTL_PROC(_kern_ipc, OID_AUTO, nmbjumbop, 249 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, &nmbjumbop, 0, 250 sysctl_nmbjumbop, "IU", 251 "Maximum number of mbuf page size jumbo clusters allowed"); 252 253 static int 254 sysctl_nmbjumbo9(SYSCTL_HANDLER_ARGS) 255 { 256 int error, newnmbjumbo9; 257 258 newnmbjumbo9 = nmbjumbo9; 259 error = sysctl_handle_int(oidp, &newnmbjumbo9, 0, req); 260 if (error == 0 && req->newptr && newnmbjumbo9 != nmbjumbo9) { 261 if (newnmbjumbo9 > nmbjumbo9 && 262 nmbufs >= nmbclusters + nmbjumbop + nmbjumbo9 + nmbjumbo16) { 263 nmbjumbo9 = newnmbjumbo9; 264 nmbjumbo9 = uma_zone_set_max(zone_jumbo9, nmbjumbo9); 265 } else 266 error = EINVAL; 267 } 268 return (error); 269 } 270 SYSCTL_PROC(_kern_ipc, OID_AUTO, nmbjumbo9, 271 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, &nmbjumbo9, 0, 272 sysctl_nmbjumbo9, "IU", 273 "Maximum number of mbuf 9k jumbo clusters allowed"); 274 275 static int 276 sysctl_nmbjumbo16(SYSCTL_HANDLER_ARGS) 277 { 278 int error, newnmbjumbo16; 279 280 newnmbjumbo16 = nmbjumbo16; 281 error = sysctl_handle_int(oidp, &newnmbjumbo16, 0, req); 282 if (error == 0 && req->newptr && newnmbjumbo16 != nmbjumbo16) { 283 if (newnmbjumbo16 > nmbjumbo16 && 284 nmbufs >= nmbclusters + nmbjumbop + nmbjumbo9 + nmbjumbo16) { 285 nmbjumbo16 = newnmbjumbo16; 286 nmbjumbo16 = uma_zone_set_max(zone_jumbo16, nmbjumbo16); 287 } else 288 error = EINVAL; 289 } 290 return (error); 291 } 292 SYSCTL_PROC(_kern_ipc, OID_AUTO, nmbjumbo16, 293 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, &nmbjumbo16, 0, 294 sysctl_nmbjumbo16, "IU", 295 "Maximum number of mbuf 16k jumbo clusters allowed"); 296 297 static int 298 sysctl_nmbufs(SYSCTL_HANDLER_ARGS) 299 { 300 int error, newnmbufs; 301 302 newnmbufs = nmbufs; 303 error = sysctl_handle_int(oidp, &newnmbufs, 0, req); 304 if (error == 0 && req->newptr && newnmbufs != nmbufs) { 305 if (newnmbufs > nmbufs) { 306 nmbufs = newnmbufs; 307 nmbufs = uma_zone_set_max(zone_mbuf, nmbufs); 308 EVENTHANDLER_INVOKE(nmbufs_change); 309 } else 310 error = EINVAL; 311 } 312 return (error); 313 } 314 SYSCTL_PROC(_kern_ipc, OID_AUTO, nmbufs, 315 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, 316 &nmbufs, 0, sysctl_nmbufs, "IU", 317 "Maximum number of mbufs allowed"); 318 319 /* 320 * Zones from which we allocate. 321 */ 322 uma_zone_t zone_mbuf; 323 uma_zone_t zone_clust; 324 uma_zone_t zone_pack; 325 uma_zone_t zone_jumbop; 326 uma_zone_t zone_jumbo9; 327 uma_zone_t zone_jumbo16; 328 329 /* 330 * Local prototypes. 331 */ 332 static int mb_ctor_mbuf(void *, int, void *, int); 333 static int mb_ctor_clust(void *, int, void *, int); 334 static int mb_ctor_pack(void *, int, void *, int); 335 static void mb_dtor_mbuf(void *, int, void *); 336 static void mb_dtor_pack(void *, int, void *); 337 static int mb_zinit_pack(void *, int, int); 338 static void mb_zfini_pack(void *, int); 339 static void mb_reclaim(uma_zone_t, int); 340 341 /* Ensure that MSIZE is a power of 2. */ 342 CTASSERT((((MSIZE - 1) ^ MSIZE) + 1) >> 1 == MSIZE); 343 344 _Static_assert(sizeof(struct mbuf) <= MSIZE, 345 "size of mbuf exceeds MSIZE"); 346 /* 347 * Initialize FreeBSD Network buffer allocation. 348 */ 349 static void 350 mbuf_init(void *dummy) 351 { 352 353 /* 354 * Configure UMA zones for Mbufs, Clusters, and Packets. 355 */ 356 zone_mbuf = uma_zcreate(MBUF_MEM_NAME, MSIZE, 357 mb_ctor_mbuf, mb_dtor_mbuf, NULL, NULL, 358 MSIZE - 1, UMA_ZONE_CONTIG | UMA_ZONE_MAXBUCKET); 359 if (nmbufs > 0) 360 nmbufs = uma_zone_set_max(zone_mbuf, nmbufs); 361 uma_zone_set_warning(zone_mbuf, "kern.ipc.nmbufs limit reached"); 362 uma_zone_set_maxaction(zone_mbuf, mb_reclaim); 363 364 zone_clust = uma_zcreate(MBUF_CLUSTER_MEM_NAME, MCLBYTES, 365 mb_ctor_clust, NULL, NULL, NULL, 366 UMA_ALIGN_PTR, UMA_ZONE_CONTIG); 367 if (nmbclusters > 0) 368 nmbclusters = uma_zone_set_max(zone_clust, nmbclusters); 369 uma_zone_set_warning(zone_clust, "kern.ipc.nmbclusters limit reached"); 370 uma_zone_set_maxaction(zone_clust, mb_reclaim); 371 372 zone_pack = uma_zsecond_create(MBUF_PACKET_MEM_NAME, mb_ctor_pack, 373 mb_dtor_pack, mb_zinit_pack, mb_zfini_pack, zone_mbuf); 374 375 /* Make jumbo frame zone too. Page size, 9k and 16k. */ 376 zone_jumbop = uma_zcreate(MBUF_JUMBOP_MEM_NAME, MJUMPAGESIZE, 377 mb_ctor_clust, NULL, NULL, NULL, 378 UMA_ALIGN_PTR, UMA_ZONE_CONTIG); 379 if (nmbjumbop > 0) 380 nmbjumbop = uma_zone_set_max(zone_jumbop, nmbjumbop); 381 uma_zone_set_warning(zone_jumbop, "kern.ipc.nmbjumbop limit reached"); 382 uma_zone_set_maxaction(zone_jumbop, mb_reclaim); 383 384 zone_jumbo9 = uma_zcreate(MBUF_JUMBO9_MEM_NAME, MJUM9BYTES, 385 mb_ctor_clust, NULL, NULL, NULL, 386 UMA_ALIGN_PTR, UMA_ZONE_CONTIG); 387 if (nmbjumbo9 > 0) 388 nmbjumbo9 = uma_zone_set_max(zone_jumbo9, nmbjumbo9); 389 uma_zone_set_warning(zone_jumbo9, "kern.ipc.nmbjumbo9 limit reached"); 390 uma_zone_set_maxaction(zone_jumbo9, mb_reclaim); 391 392 zone_jumbo16 = uma_zcreate(MBUF_JUMBO16_MEM_NAME, MJUM16BYTES, 393 mb_ctor_clust, NULL, NULL, NULL, 394 UMA_ALIGN_PTR, UMA_ZONE_CONTIG); 395 if (nmbjumbo16 > 0) 396 nmbjumbo16 = uma_zone_set_max(zone_jumbo16, nmbjumbo16); 397 uma_zone_set_warning(zone_jumbo16, "kern.ipc.nmbjumbo16 limit reached"); 398 uma_zone_set_maxaction(zone_jumbo16, mb_reclaim); 399 400 snd_tag_count = counter_u64_alloc(M_WAITOK); 401 } 402 SYSINIT(mbuf, SI_SUB_MBUF, SI_ORDER_FIRST, mbuf_init, NULL); 403 404 #ifdef DEBUGNET 405 /* 406 * debugnet makes use of a pre-allocated pool of mbufs and clusters. When 407 * debugnet is configured, we initialize a set of UMA cache zones which return 408 * items from this pool. At panic-time, the regular UMA zone pointers are 409 * overwritten with those of the cache zones so that drivers may allocate and 410 * free mbufs and clusters without attempting to allocate physical memory. 411 * 412 * We keep mbufs and clusters in a pair of mbuf queues. In particular, for 413 * the purpose of caching clusters, we treat them as mbufs. 414 */ 415 static struct mbufq dn_mbufq = 416 { STAILQ_HEAD_INITIALIZER(dn_mbufq.mq_head), 0, INT_MAX }; 417 static struct mbufq dn_clustq = 418 { STAILQ_HEAD_INITIALIZER(dn_clustq.mq_head), 0, INT_MAX }; 419 420 static int dn_clsize; 421 static uma_zone_t dn_zone_mbuf; 422 static uma_zone_t dn_zone_clust; 423 static uma_zone_t dn_zone_pack; 424 425 static struct debugnet_saved_zones { 426 uma_zone_t dsz_mbuf; 427 uma_zone_t dsz_clust; 428 uma_zone_t dsz_pack; 429 uma_zone_t dsz_jumbop; 430 uma_zone_t dsz_jumbo9; 431 uma_zone_t dsz_jumbo16; 432 bool dsz_debugnet_zones_enabled; 433 } dn_saved_zones; 434 435 static int 436 dn_buf_import(void *arg, void **store, int count, int domain __unused, 437 int flags) 438 { 439 struct mbufq *q; 440 struct mbuf *m; 441 int i; 442 443 q = arg; 444 445 for (i = 0; i < count; i++) { 446 m = mbufq_dequeue(q); 447 if (m == NULL) 448 break; 449 trash_init(m, q == &dn_mbufq ? MSIZE : dn_clsize, flags); 450 store[i] = m; 451 } 452 KASSERT((flags & M_WAITOK) == 0 || i == count, 453 ("%s: ran out of pre-allocated mbufs", __func__)); 454 return (i); 455 } 456 457 static void 458 dn_buf_release(void *arg, void **store, int count) 459 { 460 struct mbufq *q; 461 struct mbuf *m; 462 int i; 463 464 q = arg; 465 466 for (i = 0; i < count; i++) { 467 m = store[i]; 468 (void)mbufq_enqueue(q, m); 469 } 470 } 471 472 static int 473 dn_pack_import(void *arg __unused, void **store, int count, int domain __unused, 474 int flags __unused) 475 { 476 struct mbuf *m; 477 void *clust; 478 int i; 479 480 for (i = 0; i < count; i++) { 481 m = m_get(M_NOWAIT, MT_DATA); 482 if (m == NULL) 483 break; 484 clust = uma_zalloc(dn_zone_clust, M_NOWAIT); 485 if (clust == NULL) { 486 m_free(m); 487 break; 488 } 489 mb_ctor_clust(clust, dn_clsize, m, 0); 490 store[i] = m; 491 } 492 KASSERT((flags & M_WAITOK) == 0 || i == count, 493 ("%s: ran out of pre-allocated mbufs", __func__)); 494 return (i); 495 } 496 497 static void 498 dn_pack_release(void *arg __unused, void **store, int count) 499 { 500 struct mbuf *m; 501 void *clust; 502 int i; 503 504 for (i = 0; i < count; i++) { 505 m = store[i]; 506 clust = m->m_ext.ext_buf; 507 uma_zfree(dn_zone_clust, clust); 508 uma_zfree(dn_zone_mbuf, m); 509 } 510 } 511 512 /* 513 * Free the pre-allocated mbufs and clusters reserved for debugnet, and destroy 514 * the corresponding UMA cache zones. 515 */ 516 void 517 debugnet_mbuf_drain(void) 518 { 519 struct mbuf *m; 520 void *item; 521 522 if (dn_zone_mbuf != NULL) { 523 uma_zdestroy(dn_zone_mbuf); 524 dn_zone_mbuf = NULL; 525 } 526 if (dn_zone_clust != NULL) { 527 uma_zdestroy(dn_zone_clust); 528 dn_zone_clust = NULL; 529 } 530 if (dn_zone_pack != NULL) { 531 uma_zdestroy(dn_zone_pack); 532 dn_zone_pack = NULL; 533 } 534 535 while ((m = mbufq_dequeue(&dn_mbufq)) != NULL) 536 m_free(m); 537 while ((item = mbufq_dequeue(&dn_clustq)) != NULL) 538 uma_zfree(m_getzone(dn_clsize), item); 539 } 540 541 /* 542 * Callback invoked immediately prior to starting a debugnet connection. 543 */ 544 void 545 debugnet_mbuf_start(void) 546 { 547 548 MPASS(!dn_saved_zones.dsz_debugnet_zones_enabled); 549 550 /* Save the old zone pointers to restore when debugnet is closed. */ 551 dn_saved_zones = (struct debugnet_saved_zones) { 552 .dsz_debugnet_zones_enabled = true, 553 .dsz_mbuf = zone_mbuf, 554 .dsz_clust = zone_clust, 555 .dsz_pack = zone_pack, 556 .dsz_jumbop = zone_jumbop, 557 .dsz_jumbo9 = zone_jumbo9, 558 .dsz_jumbo16 = zone_jumbo16, 559 }; 560 561 /* 562 * All cluster zones return buffers of the size requested by the 563 * drivers. It's up to the driver to reinitialize the zones if the 564 * MTU of a debugnet-enabled interface changes. 565 */ 566 printf("debugnet: overwriting mbuf zone pointers\n"); 567 zone_mbuf = dn_zone_mbuf; 568 zone_clust = dn_zone_clust; 569 zone_pack = dn_zone_pack; 570 zone_jumbop = dn_zone_clust; 571 zone_jumbo9 = dn_zone_clust; 572 zone_jumbo16 = dn_zone_clust; 573 } 574 575 /* 576 * Callback invoked when a debugnet connection is closed/finished. 577 */ 578 void 579 debugnet_mbuf_finish(void) 580 { 581 582 MPASS(dn_saved_zones.dsz_debugnet_zones_enabled); 583 584 printf("debugnet: restoring mbuf zone pointers\n"); 585 zone_mbuf = dn_saved_zones.dsz_mbuf; 586 zone_clust = dn_saved_zones.dsz_clust; 587 zone_pack = dn_saved_zones.dsz_pack; 588 zone_jumbop = dn_saved_zones.dsz_jumbop; 589 zone_jumbo9 = dn_saved_zones.dsz_jumbo9; 590 zone_jumbo16 = dn_saved_zones.dsz_jumbo16; 591 592 memset(&dn_saved_zones, 0, sizeof(dn_saved_zones)); 593 } 594 595 /* 596 * Reinitialize the debugnet mbuf+cluster pool and cache zones. 597 */ 598 void 599 debugnet_mbuf_reinit(int nmbuf, int nclust, int clsize) 600 { 601 struct mbuf *m; 602 void *item; 603 604 debugnet_mbuf_drain(); 605 606 dn_clsize = clsize; 607 608 dn_zone_mbuf = uma_zcache_create("debugnet_" MBUF_MEM_NAME, 609 MSIZE, mb_ctor_mbuf, mb_dtor_mbuf, NULL, NULL, 610 dn_buf_import, dn_buf_release, 611 &dn_mbufq, UMA_ZONE_NOBUCKET); 612 613 dn_zone_clust = uma_zcache_create("debugnet_" MBUF_CLUSTER_MEM_NAME, 614 clsize, mb_ctor_clust, NULL, NULL, NULL, 615 dn_buf_import, dn_buf_release, 616 &dn_clustq, UMA_ZONE_NOBUCKET); 617 618 dn_zone_pack = uma_zcache_create("debugnet_" MBUF_PACKET_MEM_NAME, 619 MCLBYTES, mb_ctor_pack, mb_dtor_pack, NULL, NULL, 620 dn_pack_import, dn_pack_release, 621 NULL, UMA_ZONE_NOBUCKET); 622 623 while (nmbuf-- > 0) { 624 m = m_get(M_WAITOK, MT_DATA); 625 uma_zfree(dn_zone_mbuf, m); 626 } 627 while (nclust-- > 0) { 628 item = uma_zalloc(m_getzone(dn_clsize), M_WAITOK); 629 uma_zfree(dn_zone_clust, item); 630 } 631 } 632 #endif /* DEBUGNET */ 633 634 /* 635 * Constructor for Mbuf primary zone. 636 * 637 * The 'arg' pointer points to a mb_args structure which 638 * contains call-specific information required to support the 639 * mbuf allocation API. See mbuf.h. 640 */ 641 static int 642 mb_ctor_mbuf(void *mem, int size, void *arg, int how) 643 { 644 struct mbuf *m; 645 struct mb_args *args; 646 int error; 647 int flags; 648 short type; 649 650 args = (struct mb_args *)arg; 651 type = args->type; 652 653 /* 654 * The mbuf is initialized later. The caller has the 655 * responsibility to set up any MAC labels too. 656 */ 657 if (type == MT_NOINIT) 658 return (0); 659 660 m = (struct mbuf *)mem; 661 flags = args->flags; 662 MPASS((flags & M_NOFREE) == 0); 663 664 error = m_init(m, how, type, flags); 665 666 return (error); 667 } 668 669 /* 670 * The Mbuf primary zone destructor. 671 */ 672 static void 673 mb_dtor_mbuf(void *mem, int size, void *arg) 674 { 675 struct mbuf *m; 676 unsigned long flags __diagused; 677 678 m = (struct mbuf *)mem; 679 flags = (unsigned long)arg; 680 681 KASSERT((m->m_flags & M_NOFREE) == 0, ("%s: M_NOFREE set", __func__)); 682 KASSERT((flags & 0x1) == 0, ("%s: obsolete MB_DTOR_SKIP passed", __func__)); 683 if ((m->m_flags & M_PKTHDR) && !SLIST_EMPTY(&m->m_pkthdr.tags)) 684 m_tag_delete_chain(m, NULL); 685 } 686 687 /* 688 * The Mbuf Packet zone destructor. 689 */ 690 static void 691 mb_dtor_pack(void *mem, int size, void *arg) 692 { 693 struct mbuf *m; 694 695 m = (struct mbuf *)mem; 696 if ((m->m_flags & M_PKTHDR) != 0) 697 m_tag_delete_chain(m, NULL); 698 699 /* Make sure we've got a clean cluster back. */ 700 KASSERT((m->m_flags & M_EXT) == M_EXT, ("%s: M_EXT not set", __func__)); 701 KASSERT(m->m_ext.ext_buf != NULL, ("%s: ext_buf == NULL", __func__)); 702 KASSERT(m->m_ext.ext_free == NULL, ("%s: ext_free != NULL", __func__)); 703 KASSERT(m->m_ext.ext_arg1 == NULL, ("%s: ext_arg1 != NULL", __func__)); 704 KASSERT(m->m_ext.ext_arg2 == NULL, ("%s: ext_arg2 != NULL", __func__)); 705 KASSERT(m->m_ext.ext_size == MCLBYTES, ("%s: ext_size != MCLBYTES", __func__)); 706 KASSERT(m->m_ext.ext_type == EXT_PACKET, ("%s: ext_type != EXT_PACKET", __func__)); 707 #if defined(INVARIANTS) && !defined(KMSAN) 708 trash_dtor(m->m_ext.ext_buf, MCLBYTES, arg); 709 #endif 710 /* 711 * If there are processes blocked on zone_clust, waiting for pages 712 * to be freed up, cause them to be woken up by draining the 713 * packet zone. We are exposed to a race here (in the check for 714 * the UMA_ZFLAG_FULL) where we might miss the flag set, but that 715 * is deliberate. We don't want to acquire the zone lock for every 716 * mbuf free. 717 */ 718 if (uma_zone_exhausted(zone_clust)) 719 uma_zone_reclaim(zone_pack, UMA_RECLAIM_DRAIN); 720 } 721 722 /* 723 * The Cluster and Jumbo[PAGESIZE|9|16] zone constructor. 724 * 725 * Here the 'arg' pointer points to the Mbuf which we 726 * are configuring cluster storage for. If 'arg' is 727 * empty we allocate just the cluster without setting 728 * the mbuf to it. See mbuf.h. 729 */ 730 static int 731 mb_ctor_clust(void *mem, int size, void *arg, int how) 732 { 733 struct mbuf *m; 734 735 m = (struct mbuf *)arg; 736 if (m != NULL) { 737 m->m_ext.ext_buf = (char *)mem; 738 m->m_data = m->m_ext.ext_buf; 739 m->m_flags |= M_EXT; 740 m->m_ext.ext_free = NULL; 741 m->m_ext.ext_arg1 = NULL; 742 m->m_ext.ext_arg2 = NULL; 743 m->m_ext.ext_size = size; 744 m->m_ext.ext_type = m_gettype(size); 745 m->m_ext.ext_flags = EXT_FLAG_EMBREF; 746 m->m_ext.ext_count = 1; 747 } 748 749 return (0); 750 } 751 752 /* 753 * The Packet secondary zone's init routine, executed on the 754 * object's transition from mbuf keg slab to zone cache. 755 */ 756 static int 757 mb_zinit_pack(void *mem, int size, int how) 758 { 759 struct mbuf *m; 760 761 m = (struct mbuf *)mem; /* m is virgin. */ 762 if (uma_zalloc_arg(zone_clust, m, how) == NULL || 763 m->m_ext.ext_buf == NULL) 764 return (ENOMEM); 765 m->m_ext.ext_type = EXT_PACKET; /* Override. */ 766 #if defined(INVARIANTS) && !defined(KMSAN) 767 trash_init(m->m_ext.ext_buf, MCLBYTES, how); 768 #endif 769 return (0); 770 } 771 772 /* 773 * The Packet secondary zone's fini routine, executed on the 774 * object's transition from zone cache to keg slab. 775 */ 776 static void 777 mb_zfini_pack(void *mem, int size) 778 { 779 struct mbuf *m; 780 781 m = (struct mbuf *)mem; 782 #if defined(INVARIANTS) && !defined(KMSAN) 783 trash_fini(m->m_ext.ext_buf, MCLBYTES); 784 #endif 785 uma_zfree_arg(zone_clust, m->m_ext.ext_buf, NULL); 786 #if defined(INVARIANTS) && !defined(KMSAN) 787 trash_dtor(mem, size, NULL); 788 #endif 789 } 790 791 /* 792 * The "packet" keg constructor. 793 */ 794 static int 795 mb_ctor_pack(void *mem, int size, void *arg, int how) 796 { 797 struct mbuf *m; 798 struct mb_args *args; 799 int error, flags; 800 short type; 801 802 m = (struct mbuf *)mem; 803 args = (struct mb_args *)arg; 804 flags = args->flags; 805 type = args->type; 806 MPASS((flags & M_NOFREE) == 0); 807 808 #if defined(INVARIANTS) && !defined(KMSAN) 809 trash_ctor(m->m_ext.ext_buf, MCLBYTES, arg, how); 810 #endif 811 812 error = m_init(m, how, type, flags); 813 814 /* m_ext is already initialized. */ 815 m->m_data = m->m_ext.ext_buf; 816 m->m_flags = (flags | M_EXT); 817 818 return (error); 819 } 820 821 /* 822 * This is the protocol drain routine. Called by UMA whenever any of the 823 * mbuf zones is closed to its limit. 824 */ 825 static void 826 mb_reclaim(uma_zone_t zone __unused, int pending __unused) 827 { 828 829 EVENTHANDLER_INVOKE(mbuf_lowmem, VM_LOW_MBUFS); 830 } 831 832 /* 833 * Free "count" units of I/O from an mbuf chain. They could be held 834 * in M_EXTPG or just as a normal mbuf. This code is intended to be 835 * called in an error path (I/O error, closed connection, etc). 836 */ 837 void 838 mb_free_notready(struct mbuf *m, int count) 839 { 840 int i; 841 842 for (i = 0; i < count && m != NULL; i++) { 843 if ((m->m_flags & M_EXTPG) != 0) { 844 m->m_epg_nrdy--; 845 if (m->m_epg_nrdy != 0) 846 continue; 847 } 848 m = m_free(m); 849 } 850 KASSERT(i == count, ("Removed only %d items from %p", i, m)); 851 } 852 853 /* 854 * Compress an unmapped mbuf into a simple mbuf when it holds a small 855 * amount of data. This is used as a DOS defense to avoid having 856 * small packets tie up wired pages, an ext_pgs structure, and an 857 * mbuf. Since this converts the existing mbuf in place, it can only 858 * be used if there are no other references to 'm'. 859 */ 860 int 861 mb_unmapped_compress(struct mbuf *m) 862 { 863 volatile u_int *refcnt; 864 char buf[MLEN]; 865 866 /* 867 * Assert that 'm' does not have a packet header. If 'm' had 868 * a packet header, it would only be able to hold MHLEN bytes 869 * and m_data would have to be initialized differently. 870 */ 871 KASSERT((m->m_flags & M_PKTHDR) == 0 && (m->m_flags & M_EXTPG), 872 ("%s: m %p !M_EXTPG or M_PKTHDR", __func__, m)); 873 KASSERT(m->m_len <= MLEN, ("m_len too large %p", m)); 874 875 if (m->m_ext.ext_flags & EXT_FLAG_EMBREF) { 876 refcnt = &m->m_ext.ext_count; 877 } else { 878 KASSERT(m->m_ext.ext_cnt != NULL, 879 ("%s: no refcounting pointer on %p", __func__, m)); 880 refcnt = m->m_ext.ext_cnt; 881 } 882 883 if (*refcnt != 1) 884 return (EBUSY); 885 886 m_copydata(m, 0, m->m_len, buf); 887 888 /* Free the backing pages. */ 889 m->m_ext.ext_free(m); 890 891 /* Turn 'm' into a "normal" mbuf. */ 892 m->m_flags &= ~(M_EXT | M_RDONLY | M_EXTPG); 893 m->m_data = m->m_dat; 894 895 /* Copy data back into m. */ 896 bcopy(buf, mtod(m, char *), m->m_len); 897 898 return (0); 899 } 900 901 /* 902 * These next few routines are used to permit downgrading an unmapped 903 * mbuf to a chain of mapped mbufs. This is used when an interface 904 * doesn't supported unmapped mbufs or if checksums need to be 905 * computed in software. 906 * 907 * Each unmapped mbuf is converted to a chain of mbufs. First, any 908 * TLS header data is stored in a regular mbuf. Second, each page of 909 * unmapped data is stored in an mbuf with an EXT_SFBUF external 910 * cluster. These mbufs use an sf_buf to provide a valid KVA for the 911 * associated physical page. They also hold a reference on the 912 * original M_EXTPG mbuf to ensure the physical page doesn't go away. 913 * Finally, any TLS trailer data is stored in a regular mbuf. 914 * 915 * mb_unmapped_free_mext() is the ext_free handler for the EXT_SFBUF 916 * mbufs. It frees the associated sf_buf and releases its reference 917 * on the original M_EXTPG mbuf. 918 * 919 * _mb_unmapped_to_ext() is a helper function that converts a single 920 * unmapped mbuf into a chain of mbufs. 921 * 922 * mb_unmapped_to_ext() is the public function that walks an mbuf 923 * chain converting any unmapped mbufs to mapped mbufs. It returns 924 * the new chain of unmapped mbufs on success. On failure it frees 925 * the original mbuf chain and returns NULL. 926 */ 927 static void 928 mb_unmapped_free_mext(struct mbuf *m) 929 { 930 struct sf_buf *sf; 931 struct mbuf *old_m; 932 933 sf = m->m_ext.ext_arg1; 934 sf_buf_free(sf); 935 936 /* Drop the reference on the backing M_EXTPG mbuf. */ 937 old_m = m->m_ext.ext_arg2; 938 mb_free_extpg(old_m); 939 } 940 941 static struct mbuf * 942 _mb_unmapped_to_ext(struct mbuf *m) 943 { 944 struct mbuf *m_new, *top, *prev, *mref; 945 struct sf_buf *sf; 946 vm_page_t pg; 947 int i, len, off, pglen, pgoff, seglen, segoff; 948 volatile u_int *refcnt; 949 u_int ref_inc = 0; 950 951 M_ASSERTEXTPG(m); 952 len = m->m_len; 953 KASSERT(m->m_epg_tls == NULL, ("%s: can't convert TLS mbuf %p", 954 __func__, m)); 955 956 /* See if this is the mbuf that holds the embedded refcount. */ 957 if (m->m_ext.ext_flags & EXT_FLAG_EMBREF) { 958 refcnt = &m->m_ext.ext_count; 959 mref = m; 960 } else { 961 KASSERT(m->m_ext.ext_cnt != NULL, 962 ("%s: no refcounting pointer on %p", __func__, m)); 963 refcnt = m->m_ext.ext_cnt; 964 mref = __containerof(refcnt, struct mbuf, m_ext.ext_count); 965 } 966 967 /* Skip over any data removed from the front. */ 968 off = mtod(m, vm_offset_t); 969 970 top = NULL; 971 if (m->m_epg_hdrlen != 0) { 972 if (off >= m->m_epg_hdrlen) { 973 off -= m->m_epg_hdrlen; 974 } else { 975 seglen = m->m_epg_hdrlen - off; 976 segoff = off; 977 seglen = min(seglen, len); 978 off = 0; 979 len -= seglen; 980 m_new = m_get(M_NOWAIT, MT_DATA); 981 if (m_new == NULL) 982 goto fail; 983 m_new->m_len = seglen; 984 prev = top = m_new; 985 memcpy(mtod(m_new, void *), &m->m_epg_hdr[segoff], 986 seglen); 987 } 988 } 989 pgoff = m->m_epg_1st_off; 990 for (i = 0; i < m->m_epg_npgs && len > 0; i++) { 991 pglen = m_epg_pagelen(m, i, pgoff); 992 if (off >= pglen) { 993 off -= pglen; 994 pgoff = 0; 995 continue; 996 } 997 seglen = pglen - off; 998 segoff = pgoff + off; 999 off = 0; 1000 seglen = min(seglen, len); 1001 len -= seglen; 1002 1003 pg = PHYS_TO_VM_PAGE(m->m_epg_pa[i]); 1004 m_new = m_get(M_NOWAIT, MT_DATA); 1005 if (m_new == NULL) 1006 goto fail; 1007 if (top == NULL) { 1008 top = prev = m_new; 1009 } else { 1010 prev->m_next = m_new; 1011 prev = m_new; 1012 } 1013 sf = sf_buf_alloc(pg, SFB_NOWAIT); 1014 if (sf == NULL) 1015 goto fail; 1016 1017 ref_inc++; 1018 m_extadd(m_new, (char *)sf_buf_kva(sf), PAGE_SIZE, 1019 mb_unmapped_free_mext, sf, mref, M_RDONLY, EXT_SFBUF); 1020 m_new->m_data += segoff; 1021 m_new->m_len = seglen; 1022 1023 pgoff = 0; 1024 }; 1025 if (len != 0) { 1026 KASSERT((off + len) <= m->m_epg_trllen, 1027 ("off + len > trail (%d + %d > %d)", off, len, 1028 m->m_epg_trllen)); 1029 m_new = m_get(M_NOWAIT, MT_DATA); 1030 if (m_new == NULL) 1031 goto fail; 1032 if (top == NULL) 1033 top = m_new; 1034 else 1035 prev->m_next = m_new; 1036 m_new->m_len = len; 1037 memcpy(mtod(m_new, void *), &m->m_epg_trail[off], len); 1038 } 1039 1040 if (ref_inc != 0) { 1041 /* 1042 * Obtain an additional reference on the old mbuf for 1043 * each created EXT_SFBUF mbuf. They will be dropped 1044 * in mb_unmapped_free_mext(). 1045 */ 1046 if (*refcnt == 1) 1047 *refcnt += ref_inc; 1048 else 1049 atomic_add_int(refcnt, ref_inc); 1050 } 1051 m_free(m); 1052 return (top); 1053 1054 fail: 1055 if (ref_inc != 0) { 1056 /* 1057 * Obtain an additional reference on the old mbuf for 1058 * each created EXT_SFBUF mbuf. They will be 1059 * immediately dropped when these mbufs are freed 1060 * below. 1061 */ 1062 if (*refcnt == 1) 1063 *refcnt += ref_inc; 1064 else 1065 atomic_add_int(refcnt, ref_inc); 1066 } 1067 m_free(m); 1068 m_freem(top); 1069 return (NULL); 1070 } 1071 1072 struct mbuf * 1073 mb_unmapped_to_ext(struct mbuf *top) 1074 { 1075 struct mbuf *m, *next, *prev = NULL; 1076 1077 prev = NULL; 1078 for (m = top; m != NULL; m = next) { 1079 /* m might be freed, so cache the next pointer. */ 1080 next = m->m_next; 1081 if (m->m_flags & M_EXTPG) { 1082 if (prev != NULL) { 1083 /* 1084 * Remove 'm' from the new chain so 1085 * that the 'top' chain terminates 1086 * before 'm' in case 'top' is freed 1087 * due to an error. 1088 */ 1089 prev->m_next = NULL; 1090 } 1091 m = _mb_unmapped_to_ext(m); 1092 if (m == NULL) { 1093 m_freem(top); 1094 m_freem(next); 1095 return (NULL); 1096 } 1097 if (prev == NULL) { 1098 top = m; 1099 } else { 1100 prev->m_next = m; 1101 } 1102 1103 /* 1104 * Replaced one mbuf with a chain, so we must 1105 * find the end of chain. 1106 */ 1107 prev = m_last(m); 1108 } else { 1109 if (prev != NULL) { 1110 prev->m_next = m; 1111 } 1112 prev = m; 1113 } 1114 } 1115 return (top); 1116 } 1117 1118 /* 1119 * Allocate an empty M_EXTPG mbuf. The ext_free routine is 1120 * responsible for freeing any pages backing this mbuf when it is 1121 * freed. 1122 */ 1123 struct mbuf * 1124 mb_alloc_ext_pgs(int how, m_ext_free_t ext_free) 1125 { 1126 struct mbuf *m; 1127 1128 m = m_get(how, MT_DATA); 1129 if (m == NULL) 1130 return (NULL); 1131 1132 m->m_epg_npgs = 0; 1133 m->m_epg_nrdy = 0; 1134 m->m_epg_1st_off = 0; 1135 m->m_epg_last_len = 0; 1136 m->m_epg_flags = 0; 1137 m->m_epg_hdrlen = 0; 1138 m->m_epg_trllen = 0; 1139 m->m_epg_tls = NULL; 1140 m->m_epg_so = NULL; 1141 m->m_data = NULL; 1142 m->m_flags |= (M_EXT | M_RDONLY | M_EXTPG); 1143 m->m_ext.ext_flags = EXT_FLAG_EMBREF; 1144 m->m_ext.ext_count = 1; 1145 m->m_ext.ext_size = 0; 1146 m->m_ext.ext_free = ext_free; 1147 return (m); 1148 } 1149 1150 /* 1151 * Clean up after mbufs with M_EXT storage attached to them if the 1152 * reference count hits 1. 1153 */ 1154 void 1155 mb_free_ext(struct mbuf *m) 1156 { 1157 volatile u_int *refcnt; 1158 struct mbuf *mref; 1159 int freembuf; 1160 1161 KASSERT(m->m_flags & M_EXT, ("%s: M_EXT not set on %p", __func__, m)); 1162 1163 /* See if this is the mbuf that holds the embedded refcount. */ 1164 if (m->m_ext.ext_flags & EXT_FLAG_EMBREF) { 1165 refcnt = &m->m_ext.ext_count; 1166 mref = m; 1167 } else { 1168 KASSERT(m->m_ext.ext_cnt != NULL, 1169 ("%s: no refcounting pointer on %p", __func__, m)); 1170 refcnt = m->m_ext.ext_cnt; 1171 mref = __containerof(refcnt, struct mbuf, m_ext.ext_count); 1172 } 1173 1174 /* 1175 * Check if the header is embedded in the cluster. It is 1176 * important that we can't touch any of the mbuf fields 1177 * after we have freed the external storage, since mbuf 1178 * could have been embedded in it. For now, the mbufs 1179 * embedded into the cluster are always of type EXT_EXTREF, 1180 * and for this type we won't free the mref. 1181 */ 1182 if (m->m_flags & M_NOFREE) { 1183 freembuf = 0; 1184 KASSERT(m->m_ext.ext_type == EXT_EXTREF || 1185 m->m_ext.ext_type == EXT_RXRING, 1186 ("%s: no-free mbuf %p has wrong type", __func__, m)); 1187 } else 1188 freembuf = 1; 1189 1190 /* Free attached storage if this mbuf is the only reference to it. */ 1191 if (*refcnt == 1 || atomic_fetchadd_int(refcnt, -1) == 1) { 1192 switch (m->m_ext.ext_type) { 1193 case EXT_PACKET: 1194 /* The packet zone is special. */ 1195 if (*refcnt == 0) 1196 *refcnt = 1; 1197 uma_zfree(zone_pack, mref); 1198 break; 1199 case EXT_CLUSTER: 1200 uma_zfree(zone_clust, m->m_ext.ext_buf); 1201 m_free_raw(mref); 1202 break; 1203 case EXT_JUMBOP: 1204 uma_zfree(zone_jumbop, m->m_ext.ext_buf); 1205 m_free_raw(mref); 1206 break; 1207 case EXT_JUMBO9: 1208 uma_zfree(zone_jumbo9, m->m_ext.ext_buf); 1209 m_free_raw(mref); 1210 break; 1211 case EXT_JUMBO16: 1212 uma_zfree(zone_jumbo16, m->m_ext.ext_buf); 1213 m_free_raw(mref); 1214 break; 1215 case EXT_SFBUF: 1216 case EXT_NET_DRV: 1217 case EXT_MOD_TYPE: 1218 case EXT_DISPOSABLE: 1219 KASSERT(mref->m_ext.ext_free != NULL, 1220 ("%s: ext_free not set", __func__)); 1221 mref->m_ext.ext_free(mref); 1222 m_free_raw(mref); 1223 break; 1224 case EXT_EXTREF: 1225 KASSERT(m->m_ext.ext_free != NULL, 1226 ("%s: ext_free not set", __func__)); 1227 m->m_ext.ext_free(m); 1228 break; 1229 case EXT_RXRING: 1230 KASSERT(m->m_ext.ext_free == NULL, 1231 ("%s: ext_free is set", __func__)); 1232 break; 1233 default: 1234 KASSERT(m->m_ext.ext_type == 0, 1235 ("%s: unknown ext_type", __func__)); 1236 } 1237 } 1238 1239 if (freembuf && m != mref) 1240 m_free_raw(m); 1241 } 1242 1243 /* 1244 * Clean up after mbufs with M_EXTPG storage attached to them if the 1245 * reference count hits 1. 1246 */ 1247 void 1248 mb_free_extpg(struct mbuf *m) 1249 { 1250 volatile u_int *refcnt; 1251 struct mbuf *mref; 1252 1253 M_ASSERTEXTPG(m); 1254 1255 /* See if this is the mbuf that holds the embedded refcount. */ 1256 if (m->m_ext.ext_flags & EXT_FLAG_EMBREF) { 1257 refcnt = &m->m_ext.ext_count; 1258 mref = m; 1259 } else { 1260 KASSERT(m->m_ext.ext_cnt != NULL, 1261 ("%s: no refcounting pointer on %p", __func__, m)); 1262 refcnt = m->m_ext.ext_cnt; 1263 mref = __containerof(refcnt, struct mbuf, m_ext.ext_count); 1264 } 1265 1266 /* Free attached storage if this mbuf is the only reference to it. */ 1267 if (*refcnt == 1 || atomic_fetchadd_int(refcnt, -1) == 1) { 1268 KASSERT(mref->m_ext.ext_free != NULL, 1269 ("%s: ext_free not set", __func__)); 1270 1271 mref->m_ext.ext_free(mref); 1272 #ifdef KERN_TLS 1273 if (mref->m_epg_tls != NULL && 1274 !refcount_release_if_not_last(&mref->m_epg_tls->refcount)) 1275 ktls_enqueue_to_free(mref); 1276 else 1277 #endif 1278 m_free_raw(mref); 1279 } 1280 1281 if (m != mref) 1282 m_free_raw(m); 1283 } 1284 1285 /* 1286 * Official mbuf(9) allocation KPI for stack and drivers: 1287 * 1288 * m_get() - a single mbuf without any attachments, sys/mbuf.h. 1289 * m_gethdr() - a single mbuf initialized as M_PKTHDR, sys/mbuf.h. 1290 * m_getcl() - an mbuf + 2k cluster, sys/mbuf.h. 1291 * m_clget() - attach cluster to already allocated mbuf. 1292 * m_cljget() - attach jumbo cluster to already allocated mbuf. 1293 * m_get2() - allocate minimum mbuf that would fit size argument. 1294 * m_getm2() - allocate a chain of mbufs/clusters. 1295 * m_extadd() - attach external cluster to mbuf. 1296 * 1297 * m_free() - free single mbuf with its tags and ext, sys/mbuf.h. 1298 * m_freem() - free chain of mbufs. 1299 */ 1300 1301 int 1302 m_clget(struct mbuf *m, int how) 1303 { 1304 1305 KASSERT((m->m_flags & M_EXT) == 0, ("%s: mbuf %p has M_EXT", 1306 __func__, m)); 1307 m->m_ext.ext_buf = (char *)NULL; 1308 uma_zalloc_arg(zone_clust, m, how); 1309 /* 1310 * On a cluster allocation failure, drain the packet zone and retry, 1311 * we might be able to loosen a few clusters up on the drain. 1312 */ 1313 if ((how & M_NOWAIT) && (m->m_ext.ext_buf == NULL)) { 1314 uma_zone_reclaim(zone_pack, UMA_RECLAIM_DRAIN); 1315 uma_zalloc_arg(zone_clust, m, how); 1316 } 1317 MBUF_PROBE2(m__clget, m, how); 1318 return (m->m_flags & M_EXT); 1319 } 1320 1321 /* 1322 * m_cljget() is different from m_clget() as it can allocate clusters without 1323 * attaching them to an mbuf. In that case the return value is the pointer 1324 * to the cluster of the requested size. If an mbuf was specified, it gets 1325 * the cluster attached to it and the return value can be safely ignored. 1326 * For size it takes MCLBYTES, MJUMPAGESIZE, MJUM9BYTES, MJUM16BYTES. 1327 */ 1328 void * 1329 m_cljget(struct mbuf *m, int how, int size) 1330 { 1331 uma_zone_t zone; 1332 void *retval; 1333 1334 if (m != NULL) { 1335 KASSERT((m->m_flags & M_EXT) == 0, ("%s: mbuf %p has M_EXT", 1336 __func__, m)); 1337 m->m_ext.ext_buf = NULL; 1338 } 1339 1340 zone = m_getzone(size); 1341 retval = uma_zalloc_arg(zone, m, how); 1342 1343 MBUF_PROBE4(m__cljget, m, how, size, retval); 1344 1345 return (retval); 1346 } 1347 1348 /* 1349 * m_get2() allocates minimum mbuf that would fit "size" argument. 1350 */ 1351 struct mbuf * 1352 m_get2(int size, int how, short type, int flags) 1353 { 1354 struct mb_args args; 1355 struct mbuf *m, *n; 1356 1357 args.flags = flags; 1358 args.type = type; 1359 1360 if (size <= MHLEN || (size <= MLEN && (flags & M_PKTHDR) == 0)) 1361 return (uma_zalloc_arg(zone_mbuf, &args, how)); 1362 if (size <= MCLBYTES) 1363 return (uma_zalloc_arg(zone_pack, &args, how)); 1364 1365 if (size > MJUMPAGESIZE) 1366 return (NULL); 1367 1368 m = uma_zalloc_arg(zone_mbuf, &args, how); 1369 if (m == NULL) 1370 return (NULL); 1371 1372 n = uma_zalloc_arg(zone_jumbop, m, how); 1373 if (n == NULL) { 1374 m_free_raw(m); 1375 return (NULL); 1376 } 1377 1378 return (m); 1379 } 1380 1381 /* 1382 * m_get3() allocates minimum mbuf that would fit "size" argument. 1383 * Unlike m_get2() it can allocate clusters up to MJUM16BYTES. 1384 */ 1385 struct mbuf * 1386 m_get3(int size, int how, short type, int flags) 1387 { 1388 struct mb_args args; 1389 struct mbuf *m, *n; 1390 uma_zone_t zone; 1391 1392 if (size <= MJUMPAGESIZE) 1393 return (m_get2(size, how, type, flags)); 1394 1395 if (size > MJUM16BYTES) 1396 return (NULL); 1397 1398 args.flags = flags; 1399 args.type = type; 1400 1401 m = uma_zalloc_arg(zone_mbuf, &args, how); 1402 if (m == NULL) 1403 return (NULL); 1404 1405 if (size <= MJUM9BYTES) 1406 zone = zone_jumbo9; 1407 else 1408 zone = zone_jumbo16; 1409 1410 n = uma_zalloc_arg(zone, m, how); 1411 if (n == NULL) { 1412 m_free_raw(m); 1413 return (NULL); 1414 } 1415 1416 return (m); 1417 } 1418 1419 /* 1420 * m_getjcl() returns an mbuf with a cluster of the specified size attached. 1421 * For size it takes MCLBYTES, MJUMPAGESIZE, MJUM9BYTES, MJUM16BYTES. 1422 */ 1423 struct mbuf * 1424 m_getjcl(int how, short type, int flags, int size) 1425 { 1426 struct mb_args args; 1427 struct mbuf *m, *n; 1428 uma_zone_t zone; 1429 1430 if (size == MCLBYTES) 1431 return m_getcl(how, type, flags); 1432 1433 args.flags = flags; 1434 args.type = type; 1435 1436 m = uma_zalloc_arg(zone_mbuf, &args, how); 1437 if (m == NULL) 1438 return (NULL); 1439 1440 zone = m_getzone(size); 1441 n = uma_zalloc_arg(zone, m, how); 1442 if (n == NULL) { 1443 m_free_raw(m); 1444 return (NULL); 1445 } 1446 MBUF_PROBE5(m__getjcl, how, type, flags, size, m); 1447 return (m); 1448 } 1449 1450 /* 1451 * Allocate a given length worth of mbufs and/or clusters (whatever fits 1452 * best) and return a pointer to the top of the allocated chain. If an 1453 * existing mbuf chain is provided, then we will append the new chain 1454 * to the existing one and return a pointer to the provided mbuf. 1455 */ 1456 struct mbuf * 1457 m_getm2(struct mbuf *m, int len, int how, short type, int flags) 1458 { 1459 struct mbuf *mb, *nm = NULL, *mtail = NULL; 1460 1461 KASSERT(len >= 0, ("%s: len is < 0", __func__)); 1462 1463 /* Validate flags. */ 1464 flags &= (M_PKTHDR | M_EOR); 1465 1466 /* Packet header mbuf must be first in chain. */ 1467 if ((flags & M_PKTHDR) && m != NULL) 1468 flags &= ~M_PKTHDR; 1469 1470 /* Loop and append maximum sized mbufs to the chain tail. */ 1471 while (len > 0) { 1472 mb = NULL; 1473 if (len > MCLBYTES) { 1474 mb = m_getjcl(M_NOWAIT, type, (flags & M_PKTHDR), 1475 MJUMPAGESIZE); 1476 } 1477 if (mb == NULL) { 1478 if (len >= MINCLSIZE) 1479 mb = m_getcl(how, type, (flags & M_PKTHDR)); 1480 else if (flags & M_PKTHDR) 1481 mb = m_gethdr(how, type); 1482 else 1483 mb = m_get(how, type); 1484 1485 /* 1486 * Fail the whole operation if one mbuf can't be 1487 * allocated. 1488 */ 1489 if (mb == NULL) { 1490 m_freem(nm); 1491 return (NULL); 1492 } 1493 } 1494 1495 /* Book keeping. */ 1496 len -= M_SIZE(mb); 1497 if (mtail != NULL) 1498 mtail->m_next = mb; 1499 else 1500 nm = mb; 1501 mtail = mb; 1502 flags &= ~M_PKTHDR; /* Only valid on the first mbuf. */ 1503 } 1504 if (flags & M_EOR) 1505 mtail->m_flags |= M_EOR; /* Only valid on the last mbuf. */ 1506 1507 /* If mbuf was supplied, append new chain to the end of it. */ 1508 if (m != NULL) { 1509 for (mtail = m; mtail->m_next != NULL; mtail = mtail->m_next) 1510 ; 1511 mtail->m_next = nm; 1512 mtail->m_flags &= ~M_EOR; 1513 } else 1514 m = nm; 1515 1516 return (m); 1517 } 1518 1519 /*- 1520 * Configure a provided mbuf to refer to the provided external storage 1521 * buffer and setup a reference count for said buffer. 1522 * 1523 * Arguments: 1524 * mb The existing mbuf to which to attach the provided buffer. 1525 * buf The address of the provided external storage buffer. 1526 * size The size of the provided buffer. 1527 * freef A pointer to a routine that is responsible for freeing the 1528 * provided external storage buffer. 1529 * args A pointer to an argument structure (of any type) to be passed 1530 * to the provided freef routine (may be NULL). 1531 * flags Any other flags to be passed to the provided mbuf. 1532 * type The type that the external storage buffer should be 1533 * labeled with. 1534 * 1535 * Returns: 1536 * Nothing. 1537 */ 1538 void 1539 m_extadd(struct mbuf *mb, char *buf, u_int size, m_ext_free_t freef, 1540 void *arg1, void *arg2, int flags, int type) 1541 { 1542 1543 KASSERT(type != EXT_CLUSTER, ("%s: EXT_CLUSTER not allowed", __func__)); 1544 1545 mb->m_flags |= (M_EXT | flags); 1546 mb->m_ext.ext_buf = buf; 1547 mb->m_data = mb->m_ext.ext_buf; 1548 mb->m_ext.ext_size = size; 1549 mb->m_ext.ext_free = freef; 1550 mb->m_ext.ext_arg1 = arg1; 1551 mb->m_ext.ext_arg2 = arg2; 1552 mb->m_ext.ext_type = type; 1553 1554 if (type != EXT_EXTREF) { 1555 mb->m_ext.ext_count = 1; 1556 mb->m_ext.ext_flags = EXT_FLAG_EMBREF; 1557 } else 1558 mb->m_ext.ext_flags = 0; 1559 } 1560 1561 /* 1562 * Free an entire chain of mbufs and associated external buffers, if 1563 * applicable. 1564 */ 1565 void 1566 m_freem(struct mbuf *mb) 1567 { 1568 1569 MBUF_PROBE1(m__freem, mb); 1570 while (mb != NULL) 1571 mb = m_free(mb); 1572 } 1573 1574 /* 1575 * Temporary primitive to allow freeing without going through m_free. 1576 */ 1577 void 1578 m_free_raw(struct mbuf *mb) 1579 { 1580 1581 uma_zfree(zone_mbuf, mb); 1582 } 1583 1584 int 1585 m_snd_tag_alloc(struct ifnet *ifp, union if_snd_tag_alloc_params *params, 1586 struct m_snd_tag **mstp) 1587 { 1588 1589 if (ifp->if_snd_tag_alloc == NULL) 1590 return (EOPNOTSUPP); 1591 return (ifp->if_snd_tag_alloc(ifp, params, mstp)); 1592 } 1593 1594 void 1595 m_snd_tag_init(struct m_snd_tag *mst, struct ifnet *ifp, 1596 const struct if_snd_tag_sw *sw) 1597 { 1598 1599 if_ref(ifp); 1600 mst->ifp = ifp; 1601 refcount_init(&mst->refcount, 1); 1602 mst->sw = sw; 1603 counter_u64_add(snd_tag_count, 1); 1604 } 1605 1606 void 1607 m_snd_tag_destroy(struct m_snd_tag *mst) 1608 { 1609 struct ifnet *ifp; 1610 1611 ifp = mst->ifp; 1612 mst->sw->snd_tag_free(mst); 1613 if_rele(ifp); 1614 counter_u64_add(snd_tag_count, -1); 1615 } 1616 1617 void 1618 m_rcvif_serialize(struct mbuf *m) 1619 { 1620 u_short idx, gen; 1621 1622 M_ASSERTPKTHDR(m); 1623 idx = m->m_pkthdr.rcvif->if_index; 1624 gen = m->m_pkthdr.rcvif->if_idxgen; 1625 m->m_pkthdr.rcvidx = idx; 1626 m->m_pkthdr.rcvgen = gen; 1627 if (__predict_false(m->m_pkthdr.leaf_rcvif != NULL)) { 1628 idx = m->m_pkthdr.leaf_rcvif->if_index; 1629 gen = m->m_pkthdr.leaf_rcvif->if_idxgen; 1630 } else { 1631 idx = -1; 1632 gen = 0; 1633 } 1634 m->m_pkthdr.leaf_rcvidx = idx; 1635 m->m_pkthdr.leaf_rcvgen = gen; 1636 } 1637 1638 struct ifnet * 1639 m_rcvif_restore(struct mbuf *m) 1640 { 1641 struct ifnet *ifp, *leaf_ifp; 1642 1643 M_ASSERTPKTHDR(m); 1644 NET_EPOCH_ASSERT(); 1645 1646 ifp = ifnet_byindexgen(m->m_pkthdr.rcvidx, m->m_pkthdr.rcvgen); 1647 if (ifp == NULL || (ifp->if_flags & IFF_DYING)) 1648 return (NULL); 1649 1650 if (__predict_true(m->m_pkthdr.leaf_rcvidx == (u_short)-1)) { 1651 leaf_ifp = NULL; 1652 } else { 1653 leaf_ifp = ifnet_byindexgen(m->m_pkthdr.leaf_rcvidx, 1654 m->m_pkthdr.leaf_rcvgen); 1655 if (__predict_false(leaf_ifp != NULL && (leaf_ifp->if_flags & IFF_DYING))) 1656 leaf_ifp = NULL; 1657 } 1658 1659 m->m_pkthdr.leaf_rcvif = leaf_ifp; 1660 m->m_pkthdr.rcvif = ifp; 1661 1662 return (ifp); 1663 } 1664 1665 /* 1666 * Allocate an mbuf with anonymous external pages. 1667 */ 1668 struct mbuf * 1669 mb_alloc_ext_plus_pages(int len, int how) 1670 { 1671 struct mbuf *m; 1672 vm_page_t pg; 1673 int i, npgs; 1674 1675 m = mb_alloc_ext_pgs(how, mb_free_mext_pgs); 1676 if (m == NULL) 1677 return (NULL); 1678 m->m_epg_flags |= EPG_FLAG_ANON; 1679 npgs = howmany(len, PAGE_SIZE); 1680 for (i = 0; i < npgs; i++) { 1681 do { 1682 pg = vm_page_alloc_noobj(VM_ALLOC_NODUMP | 1683 VM_ALLOC_WIRED); 1684 if (pg == NULL) { 1685 if (how == M_NOWAIT) { 1686 m->m_epg_npgs = i; 1687 m_free(m); 1688 return (NULL); 1689 } 1690 vm_wait(NULL); 1691 } 1692 } while (pg == NULL); 1693 m->m_epg_pa[i] = VM_PAGE_TO_PHYS(pg); 1694 } 1695 m->m_epg_npgs = npgs; 1696 return (m); 1697 } 1698 1699 /* 1700 * Copy the data in the mbuf chain to a chain of mbufs with anonymous external 1701 * unmapped pages. 1702 * len is the length of data in the input mbuf chain. 1703 * mlen is the maximum number of bytes put into each ext_page mbuf. 1704 */ 1705 struct mbuf * 1706 mb_mapped_to_unmapped(struct mbuf *mp, int len, int mlen, int how, 1707 struct mbuf **mlast) 1708 { 1709 struct mbuf *m, *mout; 1710 char *pgpos, *mbpos; 1711 int i, mblen, mbufsiz, pglen, xfer; 1712 1713 if (len == 0) 1714 return (NULL); 1715 mbufsiz = min(mlen, len); 1716 m = mout = mb_alloc_ext_plus_pages(mbufsiz, how); 1717 if (m == NULL) 1718 return (m); 1719 pgpos = (char *)(void *)PHYS_TO_DMAP(m->m_epg_pa[0]); 1720 pglen = PAGE_SIZE; 1721 mblen = 0; 1722 i = 0; 1723 do { 1724 if (pglen == 0) { 1725 if (++i == m->m_epg_npgs) { 1726 m->m_epg_last_len = PAGE_SIZE; 1727 mbufsiz = min(mlen, len); 1728 m->m_next = mb_alloc_ext_plus_pages(mbufsiz, 1729 how); 1730 m = m->m_next; 1731 if (m == NULL) { 1732 m_freem(mout); 1733 return (m); 1734 } 1735 i = 0; 1736 } 1737 pgpos = (char *)(void *)PHYS_TO_DMAP(m->m_epg_pa[i]); 1738 pglen = PAGE_SIZE; 1739 } 1740 while (mblen == 0) { 1741 if (mp == NULL) { 1742 m_freem(mout); 1743 return (NULL); 1744 } 1745 KASSERT((mp->m_flags & M_EXTPG) == 0, 1746 ("mb_copym_ext_pgs: ext_pgs input mbuf")); 1747 mbpos = mtod(mp, char *); 1748 mblen = mp->m_len; 1749 mp = mp->m_next; 1750 } 1751 xfer = min(mblen, pglen); 1752 memcpy(pgpos, mbpos, xfer); 1753 pgpos += xfer; 1754 mbpos += xfer; 1755 pglen -= xfer; 1756 mblen -= xfer; 1757 len -= xfer; 1758 m->m_len += xfer; 1759 } while (len > 0); 1760 m->m_epg_last_len = PAGE_SIZE - pglen; 1761 if (mlast != NULL) 1762 *mlast = m; 1763 return (mout); 1764 }
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