FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_mbuf.c
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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