Deprecate MCLGET() in favor of m_getcl() or m_getl() in order to
[dragonfly.git] / sys / kern / uipc_mbuf.c
CommitLineData
984263bc 1/*
0c33f36d 2 * Copyright (c) 2004 Jeffrey M. Hsu. All rights reserved.
66d6c637
JH
3 * Copyright (c) 2004 The DragonFly Project. All rights reserved.
4 *
5 * This code is derived from software contributed to The DragonFly Project
6 * by Jeffrey M. Hsu.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of The DragonFly Project nor the names of its
17 * contributors may be used to endorse or promote products derived
18 * from this software without specific, prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
24 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
25 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
26 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
27 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
28 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
29 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
30 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34/*
35 * Copyright (c) 2004 Jeffrey M. Hsu. All rights reserved.
36 *
37 * License terms: all terms for the DragonFly license above plus the following:
38 *
39 * 4. All advertising materials mentioning features or use of this software
40 * must display the following acknowledgement:
41 *
42 * This product includes software developed by Jeffrey M. Hsu
43 * for the DragonFly Project.
44 *
45 * This requirement may be waived with permission from Jeffrey Hsu.
46 * This requirement will sunset and may be removed on July 8 2005,
47 * after which the standard DragonFly license (as shown above) will
48 * apply.
49 */
50
51/*
984263bc
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52 * Copyright (c) 1982, 1986, 1988, 1991, 1993
53 * The Regents of the University of California. All rights reserved.
54 *
55 * Redistribution and use in source and binary forms, with or without
56 * modification, are permitted provided that the following conditions
57 * are met:
58 * 1. Redistributions of source code must retain the above copyright
59 * notice, this list of conditions and the following disclaimer.
60 * 2. Redistributions in binary form must reproduce the above copyright
61 * notice, this list of conditions and the following disclaimer in the
62 * documentation and/or other materials provided with the distribution.
63 * 3. All advertising materials mentioning features or use of this software
64 * must display the following acknowledgement:
65 * This product includes software developed by the University of
66 * California, Berkeley and its contributors.
67 * 4. Neither the name of the University nor the names of its contributors
68 * may be used to endorse or promote products derived from this software
69 * without specific prior written permission.
70 *
71 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
72 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
73 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
74 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
75 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
76 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
77 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
78 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
79 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
80 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
81 * SUCH DAMAGE.
82 *
8a3125c6 83 * @(#)uipc_mbuf.c 8.2 (Berkeley) 1/4/94
984263bc 84 * $FreeBSD: src/sys/kern/uipc_mbuf.c,v 1.51.2.24 2003/04/15 06:59:29 silby Exp $
50503f0f 85 * $DragonFly: src/sys/kern/uipc_mbuf.c,v 1.37 2005/05/29 10:08:36 hsu Exp $
984263bc
MD
86 */
87
88#include "opt_param.h"
89#include "opt_mbuf_stress_test.h"
90#include <sys/param.h>
91#include <sys/systm.h>
92#include <sys/malloc.h>
93#include <sys/mbuf.h>
94#include <sys/kernel.h>
95#include <sys/sysctl.h>
96#include <sys/domain.h>
97#include <sys/protosw.h>
0c33f36d 98#include <sys/uio.h>
ef0fdad1 99#include <sys/thread.h>
a2a5ad0d 100#include <sys/globaldata.h>
90775e29 101#include <sys/thread2.h>
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102
103#include <vm/vm.h>
104#include <vm/vm_kern.h>
105#include <vm/vm_extern.h>
106
107#ifdef INVARIANTS
108#include <machine/cpu.h>
109#endif
110
90775e29
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111/*
112 * mbuf cluster meta-data
113 */
114typedef struct mbcluster {
115 struct mbcluster *mcl_next;
116 int32_t mcl_magic;
117 int32_t mcl_refs;
118 void *mcl_data;
119} *mbcluster_t;
120
121typedef struct mbuf *mbuf_t;
122
123#define MCL_MAGIC 0x6d62636c
124
402ed7e1 125static void mbinit (void *);
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126SYSINIT(mbuf, SI_SUB_MBUF, SI_ORDER_FIRST, mbinit, NULL)
127
90775e29
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128static u_long mbtypes[MT_NTYPES];
129
984263bc 130struct mbstat mbstat;
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131int max_linkhdr;
132int max_protohdr;
133int max_hdr;
134int max_datalen;
135int m_defragpackets;
136int m_defragbytes;
137int m_defraguseless;
138int m_defragfailure;
139#ifdef MBUF_STRESS_TEST
140int m_defragrandomfailures;
141#endif
142
143int nmbclusters;
144int nmbufs;
145u_int m_mballoc_wid = 0;
146u_int m_clalloc_wid = 0;
147
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148SYSCTL_INT(_kern_ipc, KIPC_MAX_LINKHDR, max_linkhdr, CTLFLAG_RW,
149 &max_linkhdr, 0, "");
150SYSCTL_INT(_kern_ipc, KIPC_MAX_PROTOHDR, max_protohdr, CTLFLAG_RW,
151 &max_protohdr, 0, "");
152SYSCTL_INT(_kern_ipc, KIPC_MAX_HDR, max_hdr, CTLFLAG_RW, &max_hdr, 0, "");
153SYSCTL_INT(_kern_ipc, KIPC_MAX_DATALEN, max_datalen, CTLFLAG_RW,
154 &max_datalen, 0, "");
155SYSCTL_INT(_kern_ipc, OID_AUTO, mbuf_wait, CTLFLAG_RW,
156 &mbuf_wait, 0, "");
157SYSCTL_STRUCT(_kern_ipc, KIPC_MBSTAT, mbstat, CTLFLAG_RW, &mbstat, mbstat, "");
158SYSCTL_OPAQUE(_kern_ipc, OID_AUTO, mbtypes, CTLFLAG_RD, mbtypes,
159 sizeof(mbtypes), "LU", "");
b35fbf6c 160SYSCTL_INT(_kern_ipc, KIPC_NMBCLUSTERS, nmbclusters, CTLFLAG_RW,
984263bc 161 &nmbclusters, 0, "Maximum number of mbuf clusters available");
b35fbf6c 162SYSCTL_INT(_kern_ipc, OID_AUTO, nmbufs, CTLFLAG_RW, &nmbufs, 0,
984263bc
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163 "Maximum number of mbufs available");
164SYSCTL_INT(_kern_ipc, OID_AUTO, m_defragpackets, CTLFLAG_RD,
165 &m_defragpackets, 0, "");
166SYSCTL_INT(_kern_ipc, OID_AUTO, m_defragbytes, CTLFLAG_RD,
167 &m_defragbytes, 0, "");
168SYSCTL_INT(_kern_ipc, OID_AUTO, m_defraguseless, CTLFLAG_RD,
169 &m_defraguseless, 0, "");
170SYSCTL_INT(_kern_ipc, OID_AUTO, m_defragfailure, CTLFLAG_RD,
171 &m_defragfailure, 0, "");
172#ifdef MBUF_STRESS_TEST
173SYSCTL_INT(_kern_ipc, OID_AUTO, m_defragrandomfailures, CTLFLAG_RW,
174 &m_defragrandomfailures, 0, "");
175#endif
176
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177static int mcl_pool_count;
178static int mcl_pool_max = 20;
179static int mcl_free_max = 1000;
180static int mbuf_free_max = 5000;
181
182SYSCTL_INT(_kern_ipc, OID_AUTO, mcl_pool_max, CTLFLAG_RW, &mcl_pool_max, 0,
183 "Maximum number of mbufs+cluster in free list");
184SYSCTL_INT(_kern_ipc, OID_AUTO, mcl_pool_count, CTLFLAG_RD, &mcl_pool_count, 0,
185 "Current number of mbufs+cluster in free list");
186SYSCTL_INT(_kern_ipc, OID_AUTO, mcl_free_max, CTLFLAG_RW, &mcl_free_max, 0,
187 "Maximum number of clusters on the free list");
188SYSCTL_INT(_kern_ipc, OID_AUTO, mbuf_free_max, CTLFLAG_RW, &mbuf_free_max, 0,
189 "Maximum number of mbufs on the free list");
190
191static MALLOC_DEFINE(M_MBUF, "mbuf", "mbuf");
192static MALLOC_DEFINE(M_MBUFCL, "mbufcl", "mbufcl");
193
194static mbuf_t mmbfree;
195static mbcluster_t mclfree;
196static struct mbuf *mcl_pool;
197
198static void m_reclaim (void);
199static int m_mballoc(int nmb, int how);
200static int m_clalloc(int ncl, int how);
201static struct mbuf *m_mballoc_wait(int caller, int type);
202static void m_mclref(void *arg);
203static void m_mclfree(void *arg);
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204
205#ifndef NMBCLUSTERS
206#define NMBCLUSTERS (512 + maxusers * 16)
207#endif
208#ifndef NMBUFS
209#define NMBUFS (nmbclusters * 4)
210#endif
211
212/*
213 * Perform sanity checks of tunables declared above.
214 */
215static void
216tunable_mbinit(void *dummy)
217{
218
219 /*
220 * This has to be done before VM init.
221 */
222 nmbclusters = NMBCLUSTERS;
223 TUNABLE_INT_FETCH("kern.ipc.nmbclusters", &nmbclusters);
224 nmbufs = NMBUFS;
225 TUNABLE_INT_FETCH("kern.ipc.nmbufs", &nmbufs);
226 /* Sanity checks */
227 if (nmbufs < nmbclusters * 2)
228 nmbufs = nmbclusters * 2;
229
230 return;
231}
232SYSINIT(tunable_mbinit, SI_SUB_TUNABLES, SI_ORDER_ANY, tunable_mbinit, NULL);
233
234/* "number of clusters of pages" */
235#define NCL_INIT 1
236
237#define NMB_INIT 16
238
239/* ARGSUSED*/
240static void
8a3125c6 241mbinit(void *dummy)
984263bc 242{
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243 mmbfree = NULL;
244 mclfree = NULL;
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245 mbstat.m_msize = MSIZE;
246 mbstat.m_mclbytes = MCLBYTES;
247 mbstat.m_minclsize = MINCLSIZE;
248 mbstat.m_mlen = MLEN;
249 mbstat.m_mhlen = MHLEN;
250
c6339e39 251 crit_enter();
74f1caca 252 if (m_mballoc(NMB_INIT, MB_DONTWAIT) == 0)
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253 goto bad;
254#if MCLBYTES <= PAGE_SIZE
74f1caca 255 if (m_clalloc(NCL_INIT, MB_DONTWAIT) == 0)
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256 goto bad;
257#else
258 /* It's OK to call contigmalloc in this context. */
74f1caca 259 if (m_clalloc(16, MB_WAIT) == 0)
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260 goto bad;
261#endif
c6339e39 262 crit_exit();
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263 return;
264bad:
c6339e39 265 crit_exit();
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266 panic("mbinit");
267}
268
269/*
270 * Allocate at least nmb mbufs and place on mbuf free list.
90775e29
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271 * Returns the number of mbufs successfully allocated, 0 if none.
272 *
c6339e39 273 * Must be called while in a critical section.
984263bc 274 */
90775e29 275static int
8a3125c6 276m_mballoc(int nmb, int how)
984263bc 277{
1fd87d54 278 int i;
90775e29 279 struct mbuf *m;
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280
281 /*
90775e29
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282 * If we've hit the mbuf limit, stop allocating (or trying to)
283 * in order to avoid exhausting kernel memory entirely.
984263bc
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284 */
285 if ((nmb + mbstat.m_mbufs) > nmbufs)
286 return (0);
287
288 /*
90775e29
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289 * Attempt to allocate the requested number of mbufs, terminate when
290 * the allocation fails but if blocking is allowed allocate at least
291 * one.
984263bc 292 */
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293 for (i = 0; i < nmb; ++i) {
294 m = malloc(MSIZE, M_MBUF, M_NOWAIT|M_NULLOK|M_ZERO);
295 if (m == NULL) {
296 if (how == MB_WAIT) {
297 mbstat.m_wait++;
298 m = malloc(MSIZE, M_MBUF,
299 M_WAITOK|M_NULLOK|M_ZERO);
300 }
301 if (m == NULL)
302 break;
303 }
304 m->m_next = mmbfree;
305 mmbfree = m;
306 ++mbstat.m_mbufs;
307 ++mbtypes[MT_FREE];
308 how = MB_DONTWAIT;
984263bc 309 }
90775e29 310 return(i);
984263bc
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311}
312
313/*
90775e29 314 * Once mbuf memory has been exhausted and if the call to the allocation macros
74f1caca 315 * (or, in some cases, functions) is with MB_WAIT, then it is necessary to rely
984263bc
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316 * solely on reclaimed mbufs. Here we wait for an mbuf to be freed for a
317 * designated (mbuf_wait) time.
318 */
90775e29 319static struct mbuf *
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320m_mballoc_wait(int caller, int type)
321{
90775e29 322 struct mbuf *m;
984263bc 323
c6339e39 324 crit_enter();
984263bc 325 m_mballoc_wid++;
377d4740 326 if ((tsleep(&m_mballoc_wid, 0, "mballc", mbuf_wait)) == EWOULDBLOCK)
984263bc 327 m_mballoc_wid--;
c6339e39 328 crit_exit();
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329
330 /*
331 * Now that we (think) that we've got something, we will redo an
332 * MGET, but avoid getting into another instance of m_mballoc_wait()
333 * XXX: We retry to fetch _even_ if the sleep timed out. This is left
334 * this way, purposely, in the [unlikely] case that an mbuf was
335 * freed but the sleep was not awakened in time.
336 */
90775e29 337 m = NULL;
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338 switch (caller) {
339 case MGET_C:
90775e29 340 MGET(m, MB_DONTWAIT, type);
984263bc
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341 break;
342 case MGETHDR_C:
90775e29 343 MGETHDR(m, MB_DONTWAIT, type);
984263bc
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344 break;
345 default:
346 panic("m_mballoc_wait: invalid caller (%d)", caller);
347 }
348
c6339e39 349 crit_enter();
90775e29 350 if (m != NULL) { /* We waited and got something... */
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351 mbstat.m_wait++;
352 /* Wake up another if we have more free. */
353 if (mmbfree != NULL)
354 MMBWAKEUP();
355 }
c6339e39 356 crit_exit();
90775e29 357 return (m);
984263bc
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358}
359
360#if MCLBYTES > PAGE_SIZE
361static int i_want_my_mcl;
362
363static void
364kproc_mclalloc(void)
365{
366 int status;
367
c6339e39 368 crit_enter();
90775e29 369 for (;;) {
377d4740 370 tsleep(&i_want_my_mcl, 0, "mclalloc", 0);
984263bc 371
90775e29 372 while (i_want_my_mcl > 0) {
74f1caca 373 if (m_clalloc(1, MB_WAIT) == 0)
90775e29
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374 printf("m_clalloc failed even in thread context!\n");
375 --i_want_my_mcl;
984263bc
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376 }
377 }
90775e29 378 /* not reached */
c6339e39 379 crit_exit();
984263bc
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380}
381
bc6dffab 382static struct thread *mclallocthread;
984263bc
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383static struct kproc_desc mclalloc_kp = {
384 "mclalloc",
385 kproc_mclalloc,
bc6dffab 386 &mclallocthread
984263bc 387};
bc6dffab 388SYSINIT(mclallocthread, SI_SUB_KTHREAD_UPDATE, SI_ORDER_ANY, kproc_start,
984263bc
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389 &mclalloc_kp);
390#endif
391
392/*
90775e29
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393 * Allocate at least nmb mbuf clusters and place on mbuf free list.
394 * Returns the number of mbuf clusters successfully allocated, 0 if none.
395 *
c6339e39 396 * Must be called while in a critical section.
984263bc 397 */
90775e29 398static int
8a3125c6 399m_clalloc(int ncl, int how)
984263bc 400{
90775e29
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401 static int last_report;
402 mbcluster_t mcl;
403 void *data;
1fd87d54 404 int i;
984263bc
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405
406 /*
90775e29 407 * If we've hit the mbuf cluster limit, stop allocating (or trying to).
984263bc
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408 */
409 if ((ncl + mbstat.m_clusters) > nmbclusters)
90775e29 410 ncl = 0;
984263bc
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411
412 /*
90775e29
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413 * Attempt to allocate the requested number of mbuf clusters,
414 * terminate when the allocation fails but if blocking is allowed
415 * allocate at least one.
416 *
417 * We need to allocate two structures for each cluster... a
418 * ref counting / governing structure and the actual data. MCLBYTES
419 * should be a power of 2 which means that the slab allocator will
420 * return a buffer that does not cross a page boundary.
984263bc 421 */
90775e29
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422 for (i = 0; i < ncl; ++i) {
423 /*
424 * Meta structure
425 */
426 mcl = malloc(sizeof(*mcl), M_MBUFCL, M_NOWAIT|M_NULLOK|M_ZERO);
30803de3
MD
427 if (mcl == NULL) {
428 if (how == MB_WAIT) {
429 mbstat.m_wait++;
430 mcl = malloc(sizeof(*mcl),
431 M_MBUFCL, M_WAITOK|M_NULLOK|M_ZERO);
432 }
8bee47ad
MD
433 if (mcl == NULL)
434 break;
90775e29 435 }
984263bc 436
90775e29
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437 /*
438 * Physically contiguous data buffer.
439 */
984263bc 440#if MCLBYTES > PAGE_SIZE
90775e29
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441 if (how != MB_WAIT) {
442 i_want_my_mcl += ncl - i;
443 wakeup(&i_want_my_mcl);
444 mbstat.m_wait++;
445 data = NULL;
446 } else {
447 data = contigmalloc_map(MCLBYTES, M_MBUFCL,
448 M_WAITOK, 0ul, ~0ul, PAGE_SIZE, 0, kernel_map);
449 }
984263bc 450#else
90775e29
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451 data = malloc(MCLBYTES, M_MBUFCL, M_NOWAIT|M_NULLOK);
452 if (data == NULL) {
453 if (how == MB_WAIT) {
454 mbstat.m_wait++;
455 data = malloc(MCLBYTES, M_MBUFCL,
456 M_WAITOK|M_NULLOK);
457 }
458 }
984263bc 459#endif
90775e29
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460 if (data == NULL) {
461 free(mcl, M_MBUFCL);
462 break;
463 }
464 mcl->mcl_next = mclfree;
465 mcl->mcl_data = data;
466 mcl->mcl_magic = MCL_MAGIC;
467 mcl->mcl_refs = 0;
468 mclfree = mcl;
469 ++mbstat.m_clfree;
470 ++mbstat.m_clusters;
471 how = MB_DONTWAIT;
472 }
473
984263bc 474 /*
90775e29
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475 * If we could not allocate any report failure no more often then
476 * once a second.
984263bc 477 */
90775e29 478 if (i == 0) {
984263bc
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479 mbstat.m_drops++;
480 if (ticks < last_report || (ticks - last_report) >= hz) {
481 last_report = ticks;
482 printf("All mbuf clusters exhausted, please see tuning(7).\n");
483 }
984263bc 484 }
90775e29 485 return (i);
984263bc
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486}
487
488/*
90775e29
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489 * Once cluster memory has been exhausted and the allocation is called with
490 * MB_WAIT, we rely on the mclfree pointers. If nothing is free, we will
984263bc
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491 * sleep for a designated amount of time (mbuf_wait) or until we're woken up
492 * due to sudden mcluster availability.
c6339e39
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493 *
494 * Must be called while in a critical section.
984263bc 495 */
90775e29 496static void
984263bc
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497m_clalloc_wait(void)
498{
984263bc 499 /* If in interrupt context, and INVARIANTS, maintain sanity and die. */
90775e29
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500 KASSERT(mycpu->gd_intr_nesting_level == 0,
501 ("CLALLOC: CANNOT WAIT IN INTERRUPT"));
984263bc 502
90775e29
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503 /*
504 * Sleep until something's available or until we expire.
505 */
984263bc 506 m_clalloc_wid++;
377d4740 507 if ((tsleep(&m_clalloc_wid, 0, "mclalc", mbuf_wait)) == EWOULDBLOCK)
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508 m_clalloc_wid--;
509
510 /*
90775e29
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511 * Try the allocation once more, and if we see mor then two
512 * free entries wake up others as well.
984263bc 513 */
90775e29 514 m_clalloc(1, MB_WAIT);
90775e29
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515 if (mclfree && mclfree->mcl_next) {
516 MCLWAKEUP();
984263bc 517 }
90775e29 518}
984263bc 519
90775e29
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520/*
521 * Return the number of references to this mbuf's data. 0 is returned
522 * if the mbuf is not M_EXT, a reference count is returned if it is
523 * M_EXT|M_EXT_CLUSTER, and 99 is returned if it is a special M_EXT.
524 */
525int
526m_sharecount(struct mbuf *m)
527{
528 int count;
529
530 switch(m->m_flags & (M_EXT|M_EXT_CLUSTER)) {
531 case 0:
532 count = 0;
533 break;
534 case M_EXT:
535 count = 99;
536 break;
537 case M_EXT|M_EXT_CLUSTER:
538 count = ((mbcluster_t)m->m_ext.ext_arg)->mcl_refs;
539 break;
540 default:
541 panic("bad mbuf flags: %p", m);
542 count = 0;
543 }
544 return(count);
545}
546
547/*
548 * change mbuf to new type
549 */
550void
551m_chtype(struct mbuf *m, int type)
552{
c6339e39 553 crit_enter();
90775e29
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554 --mbtypes[m->m_type];
555 ++mbtypes[type];
556 m->m_type = type;
c6339e39 557 crit_exit();
984263bc
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558}
559
560/*
561 * When MGET fails, ask protocols to free space when short of memory,
562 * then re-attempt to allocate an mbuf.
563 */
564struct mbuf *
90775e29 565m_retry(int how, int t)
984263bc 566{
12496bdf 567 struct mbuf *m;
984263bc
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568
569 /*
570 * Must only do the reclaim if not in an interrupt context.
571 */
90775e29 572 if (how == MB_WAIT) {
ef0fdad1 573 KASSERT(mycpu->gd_intr_nesting_level == 0,
984263bc 574 ("MBALLOC: CANNOT WAIT IN INTERRUPT"));
984263bc
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575 m_reclaim();
576 }
577
c6339e39
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578 /*
579 * Try to pull a new mbuf out of the cache, if the cache is empty
580 * try to allocate a new one and if that doesn't work we give up.
581 */
582 crit_enter();
583 if ((m = mmbfree) == NULL) {
90775e29 584 m_mballoc(1, how);
c6339e39
MD
585 if ((m = mmbfree) == NULL) {
586 static int last_report;
587
588 mbstat.m_drops++;
589 crit_exit();
590 if (ticks < last_report ||
591 (ticks - last_report) >= hz) {
592 last_report = ticks;
593 printf("All mbufs exhausted, please see tuning(7).\n");
594 }
595 return (NULL);
984263bc
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596 }
597 }
c6339e39
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598
599 /*
600 * Cache case, adjust globals before leaving the critical section
601 */
602 mmbfree = m->m_next;
603 mbtypes[MT_FREE]--;
604 mbtypes[t]++;
605 mbstat.m_wait++;
606 crit_exit();
607
608 m->m_type = t;
609 m->m_next = NULL;
610 m->m_nextpkt = NULL;
611 m->m_data = m->m_dat;
612 m->m_flags = 0;
984263bc
MD
613 return (m);
614}
615
616/*
617 * As above; retry an MGETHDR.
618 */
619struct mbuf *
90775e29 620m_retryhdr(int how, int t)
984263bc 621{
12496bdf 622 struct mbuf *m;
984263bc
MD
623
624 /*
625 * Must only do the reclaim if not in an interrupt context.
626 */
90775e29 627 if (how == MB_WAIT) {
ef0fdad1 628 KASSERT(mycpu->gd_intr_nesting_level == 0,
984263bc 629 ("MBALLOC: CANNOT WAIT IN INTERRUPT"));
984263bc
MD
630 m_reclaim();
631 }
632
c6339e39
MD
633 /*
634 * Try to pull a new mbuf out of the cache, if the cache is empty
635 * try to allocate a new one and if that doesn't work we give up.
636 */
637 crit_enter();
638 if ((m = mmbfree) == NULL) {
90775e29 639 m_mballoc(1, how);
c6339e39
MD
640 if ((m = mmbfree) == NULL) {
641 static int last_report;
642
643 mbstat.m_drops++;
644 crit_exit();
645 if (ticks < last_report ||
646 (ticks - last_report) >= hz) {
647 last_report = ticks;
648 printf("All mbufs exhausted, please see tuning(7).\n");
649 }
650 return (NULL);
984263bc
MD
651 }
652 }
c6339e39
MD
653
654 /*
655 * Cache case, adjust globals before leaving the critical section
656 */
657 mmbfree = m->m_next;
658 mbtypes[MT_FREE]--;
659 mbtypes[t]++;
660 mbstat.m_wait++;
661 crit_exit();
662
663 m->m_type = t;
664 m->m_next = NULL;
665 m->m_nextpkt = NULL;
666 m->m_data = m->m_pktdat;
667 m->m_flags = M_PKTHDR;
668 m->m_pkthdr.rcvif = NULL;
669 SLIST_INIT(&m->m_pkthdr.tags);
670 m->m_pkthdr.csum_flags = 0;
984263bc
MD
671 return (m);
672}
673
674static void
8a3125c6 675m_reclaim(void)
984263bc 676{
1fd87d54
RG
677 struct domain *dp;
678 struct protosw *pr;
984263bc 679
c6339e39 680 crit_enter();
9c70fe43 681 SLIST_FOREACH(dp, &domains, dom_next) {
8a3125c6 682 for (pr = dp->dom_protosw; pr < dp->dom_protoswNPROTOSW; pr++) {
984263bc
MD
683 if (pr->pr_drain)
684 (*pr->pr_drain)();
8a3125c6
MD
685 }
686 }
c6339e39 687 crit_exit();
984263bc
MD
688 mbstat.m_drain++;
689}
690
691/*
c6339e39
MD
692 * Allocate an mbuf. If no mbufs are immediately available try to
693 * bring a bunch more into our cache (mmbfree list). A critical
694 * section is required to protect the mmbfree list and counters
695 * against interrupts.
984263bc
MD
696 */
697struct mbuf *
8a3125c6 698m_get(int how, int type)
984263bc 699{
12496bdf 700 struct mbuf *m;
12496bdf 701
c6339e39
MD
702 /*
703 * Try to pull a new mbuf out of the cache, if the cache is empty
704 * try to allocate a new one and if that doesn't work try even harder
705 * by calling m_retryhdr().
706 */
707 crit_enter();
708 if ((m = mmbfree) == NULL) {
90775e29 709 m_mballoc(1, how);
c6339e39
MD
710 if ((m = mmbfree) == NULL) {
711 crit_exit();
712 m = m_retry(how, type);
713 if (m == NULL && how == MB_WAIT)
714 m = m_mballoc_wait(MGET_C, type);
715 return (m);
716 }
12496bdf 717 }
c6339e39
MD
718
719 /*
720 * Cache case, adjust globals before leaving the critical section
721 */
722 mmbfree = m->m_next;
723 mbtypes[MT_FREE]--;
724 mbtypes[type]++;
725 crit_exit();
726
727 m->m_type = type;
728 m->m_next = NULL;
729 m->m_nextpkt = NULL;
730 m->m_data = m->m_dat;
731 m->m_flags = 0;
984263bc
MD
732 return (m);
733}
734
735struct mbuf *
8a3125c6 736m_gethdr(int how, int type)
984263bc 737{
12496bdf 738 struct mbuf *m;
12496bdf 739
c6339e39
MD
740 /*
741 * Try to pull a new mbuf out of the cache, if the cache is empty
742 * try to allocate a new one and if that doesn't work try even harder
743 * by calling m_retryhdr().
744 */
745 crit_enter();
746 if ((m = mmbfree) == NULL) {
90775e29 747 m_mballoc(1, how);
c6339e39
MD
748 if ((m = mmbfree) == NULL) {
749 crit_exit();
750 m = m_retryhdr(how, type);
751 if (m == NULL && how == MB_WAIT)
752 m = m_mballoc_wait(MGETHDR_C, type);
753 return(m);
754 }
12496bdf 755 }
c6339e39
MD
756
757 /*
758 * Cache case, adjust globals before leaving the critical section
759 */
760 mmbfree = m->m_next;
761 mbtypes[MT_FREE]--;
762 mbtypes[type]++;
763 crit_exit();
764
765 m->m_type = type;
766 m->m_next = NULL;
767 m->m_nextpkt = NULL;
768 m->m_data = m->m_pktdat;
769 m->m_flags = M_PKTHDR;
770 m->m_pkthdr.rcvif = NULL;
771 SLIST_INIT(&m->m_pkthdr.tags);
772 m->m_pkthdr.csum_flags = 0;
4d723e5a 773 m->m_pkthdr.fw_flags = 0;
984263bc
MD
774 return (m);
775}
776
777struct mbuf *
8a3125c6 778m_getclr(int how, int type)
984263bc 779{
1fd87d54 780 struct mbuf *m;
984263bc 781
90775e29
MD
782 if ((m = m_get(how, type)) != NULL) {
783 bzero(mtod(m, caddr_t), MLEN);
784 }
984263bc
MD
785 return (m);
786}
787
788/*
789 * m_getcl() returns an mbuf with an attached cluster.
790 * Because many network drivers use this kind of buffers a lot, it is
791 * convenient to keep a small pool of free buffers of this kind.
792 * Even a small size such as 10 gives about 10% improvement in the
793 * forwarding rate in a bridge or router.
794 * The size of this free list is controlled by the sysctl variable
795 * mcl_pool_max. The list is populated on m_freem(), and used in
796 * m_getcl() if elements are available.
797 */
984263bc
MD
798struct mbuf *
799m_getcl(int how, short type, int flags)
800{
984263bc
MD
801 struct mbuf *mp;
802
c6339e39 803 crit_enter();
984263bc
MD
804 if (flags & M_PKTHDR) {
805 if (type == MT_DATA && mcl_pool) {
806 mp = mcl_pool;
807 mcl_pool = mp->m_nextpkt;
90775e29 808 --mcl_pool_count;
c6339e39 809 crit_exit();
984263bc
MD
810 mp->m_nextpkt = NULL;
811 mp->m_data = mp->m_ext.ext_buf;
90775e29 812 mp->m_flags = M_PKTHDR|M_EXT|M_EXT_CLUSTER;
984263bc
MD
813 mp->m_pkthdr.rcvif = NULL;
814 mp->m_pkthdr.csum_flags = 0;
815 return mp;
90775e29 816 }
c6339e39 817 MGETHDR(mp, how, type);
90775e29 818 } else {
984263bc 819 MGET(mp, how, type);
90775e29 820 }
984263bc 821 if (mp) {
90775e29
MD
822 m_mclget(mp, how);
823 if ((mp->m_flags & M_EXT) == 0) {
984263bc
MD
824 m_free(mp);
825 mp = NULL;
826 }
827 }
c6339e39
MD
828 crit_exit();
829 return (mp);
984263bc
MD
830}
831
832/*
50503f0f
JH
833 * Allocate chain of requested length.
834 */
835struct mbuf *
836m_getc(int len, int how, int type)
837{
838 struct mbuf *n, *nfirst = NULL, **ntail = &nfirst;
839 int nsize;
840
841 while (len > 0) {
842 n = m_getl(len, how, type, 0, &nsize);
843 if (n == NULL)
844 goto failed;
845 n->m_len = 0;
846 *ntail = n;
847 ntail = &n->m_next;
848 len -= nsize;
849 }
850 return (nfirst);
851
852failed:
853 m_freem(nfirst);
854 return (NULL);
855}
856
857/*
858 * Allocate len-worth of mbufs and/or mbuf clusters (whatever fits best)
859 * and return a pointer to the head of the allocated chain. If m0 is
984263bc
MD
860 * non-null, then we assume that it is a single mbuf or an mbuf chain to
861 * which we want len bytes worth of mbufs and/or clusters attached, and so
50503f0f 862 * if we succeed in allocating it, we will just return a pointer to m0.
984263bc
MD
863 *
864 * If we happen to fail at any point during the allocation, we will free
865 * up everything we have already allocated and return NULL.
866 *
50503f0f 867 * Deprecated. Use m_getc() and m_cat() instead.
984263bc
MD
868 */
869struct mbuf *
50503f0f 870m_getm(struct mbuf *m0, int len, int how, int type)
984263bc 871{
50503f0f 872 struct mbuf *nfirst;
984263bc 873
50503f0f 874 nfirst = m_getc(len, how, type);
984263bc 875
50503f0f
JH
876 if (m0 != NULL) {
877 m_last(m0)->m_next = nfirst;
878 return (m0);
984263bc
MD
879 }
880
50503f0f 881 return (nfirst);
984263bc
MD
882}
883
884/*
90775e29 885 * m_mclget() - Adds a cluster to a normal mbuf, M_EXT is set on success.
b6650ec0 886 */
90775e29
MD
887void
888m_mclget(struct mbuf *m, int how)
b6650ec0 889{
90775e29 890 mbcluster_t mcl;
b6650ec0 891
90775e29 892 KKASSERT((m->m_flags & M_EXT_OLD) == 0);
b6650ec0 893
c6339e39
MD
894 /*
895 * Allocate a cluster, return if we can't get one.
896 */
897 crit_enter();
90775e29 898 if ((mcl = mclfree) == NULL) {
b6650ec0 899 m_clalloc(1, how);
90775e29
MD
900 if ((mcl = mclfree) == NULL) {
901 if (how == MB_WAIT) {
902 m_clalloc_wait();
903 mcl = mclfree;
904 }
c6339e39
MD
905 if (mcl == NULL) {
906 crit_exit();
907 return;
908 }
90775e29
MD
909 }
910 }
911
912 /*
c6339e39
MD
913 * We have a cluster, unlink it from the free list and set the ref
914 * count.
90775e29 915 */
90775e29
MD
916 KKASSERT(mcl->mcl_refs == 0);
917 mclfree = mcl->mcl_next;
918 mcl->mcl_refs = 1;
919 --mbstat.m_clfree;
c6339e39 920 crit_exit();
b6650ec0 921
90775e29 922 /*
c6339e39
MD
923 * Add the cluster to the mbuf. The caller will detect that the
924 * mbuf now has an attached cluster.
90775e29
MD
925 */
926 m->m_ext.ext_arg = mcl;
927 m->m_ext.ext_buf = mcl->mcl_data;
928 m->m_ext.ext_nref.new = m_mclref;
929 m->m_ext.ext_nfree.new = m_mclfree;
930 m->m_ext.ext_size = MCLBYTES;
931
932 m->m_data = m->m_ext.ext_buf;
933 m->m_flags |= M_EXT | M_EXT_CLUSTER;
b6650ec0
MD
934}
935
90775e29
MD
936static void
937m_mclfree(void *arg)
b6650ec0 938{
90775e29
MD
939 mbcluster_t mcl = arg;
940
941 KKASSERT(mcl->mcl_magic == MCL_MAGIC);
942 KKASSERT(mcl->mcl_refs > 0);
943 crit_enter();
944 if (--mcl->mcl_refs == 0) {
945 if (mbstat.m_clfree < mcl_free_max) {
946 mcl->mcl_next = mclfree;
947 mclfree = mcl;
948 ++mbstat.m_clfree;
949 MCLWAKEUP();
950 } else {
951 mcl->mcl_magic = -1;
952 free(mcl->mcl_data, M_MBUFCL);
953 free(mcl, M_MBUFCL);
954 --mbstat.m_clusters;
955 }
b6650ec0 956 }
90775e29 957 crit_exit();
b6650ec0
MD
958}
959
90775e29
MD
960static void
961m_mclref(void *arg)
b6650ec0 962{
90775e29
MD
963 mbcluster_t mcl = arg;
964
965 KKASSERT(mcl->mcl_magic == MCL_MAGIC);
966 crit_enter();
967 ++mcl->mcl_refs;
968 crit_exit();
b6650ec0
MD
969}
970
7eccf245
MD
971/*
972 * Helper routines for M_EXT reference/free
973 */
974static __inline void
975m_extref(const struct mbuf *m)
976{
90775e29 977 KKASSERT(m->m_ext.ext_nfree.any != NULL);
c6339e39 978 crit_enter();
90775e29
MD
979 if (m->m_flags & M_EXT_OLD)
980 m->m_ext.ext_nref.old(m->m_ext.ext_buf, m->m_ext.ext_size);
981 else
982 m->m_ext.ext_nref.new(m->m_ext.ext_arg);
c6339e39 983 crit_exit();
7eccf245
MD
984}
985
b6650ec0
MD
986/*
987 * m_free()
988 *
989 * Free a single mbuf and any associated external storage. The successor,
990 * if any, is returned.
984263bc 991 *
b6650ec0 992 * We do need to check non-first mbuf for m_aux, since some of existing
984263bc
MD
993 * code does not call M_PREPEND properly.
994 * (example: call to bpf_mtap from drivers)
995 */
984263bc 996struct mbuf *
b6650ec0 997m_free(struct mbuf *m)
984263bc 998{
b6650ec0
MD
999 struct mbuf *n;
1000
c6339e39 1001 crit_enter();
361af367 1002 KASSERT(m->m_type != MT_FREE, ("freeing free mbuf %p", m));
90775e29
MD
1003
1004 /*
1005 * Adjust our type count and delete any attached chains if the
1006 * mbuf is a packet header.
1007 */
b6650ec0
MD
1008 if ((m->m_flags & M_PKTHDR) != 0)
1009 m_tag_delete_chain(m, NULL);
90775e29
MD
1010
1011 /*
1012 * Place the mbuf on the appropriate free list. Try to maintain a
1013 * small cache of mbuf+cluster pairs.
1014 */
1015 n = m->m_next;
1016 m->m_next = NULL;
b6650ec0 1017 if (m->m_flags & M_EXT) {
90775e29
MD
1018 KKASSERT(m->m_ext.ext_nfree.any != NULL);
1019 if (mcl_pool_count < mcl_pool_max && m && m->m_next == NULL &&
1020 (m->m_flags & (M_PKTHDR|M_EXT_CLUSTER)) == (M_PKTHDR|M_EXT_CLUSTER) &&
1021 m->m_type == MT_DATA && M_EXT_WRITABLE(m) ) {
1022 KKASSERT(((mbcluster_t)m->m_ext.ext_arg)->mcl_magic == MCL_MAGIC);
1023 m->m_nextpkt = mcl_pool;
1024 mcl_pool = m;
1025 ++mcl_pool_count;
1026 m = NULL;
1027 } else {
1028 if (m->m_flags & M_EXT_OLD)
1029 m->m_ext.ext_nfree.old(m->m_ext.ext_buf, m->m_ext.ext_size);
1030 else
1031 m->m_ext.ext_nfree.new(m->m_ext.ext_arg);
1032 m->m_flags = 0;
1033 m->m_ext.ext_arg = NULL;
1034 m->m_ext.ext_nref.new = NULL;
1035 m->m_ext.ext_nfree.new = NULL;
1036 }
1037 }
1038 if (m) {
1039 --mbtypes[m->m_type];
1040 if (mbtypes[MT_FREE] < mbuf_free_max) {
1041 m->m_type = MT_FREE;
1042 mbtypes[MT_FREE]++;
1043 m->m_next = mmbfree;
1044 mmbfree = m;
1045 MMBWAKEUP();
1046 } else {
1047 free(m, M_MBUF);
1048 --mbstat.m_mbufs;
1049 }
b6650ec0 1050 }
c6339e39 1051 crit_exit();
984263bc
MD
1052 return (n);
1053}
1054
1055void
b6650ec0 1056m_freem(struct mbuf *m)
984263bc 1057{
c6339e39 1058 crit_enter();
90775e29
MD
1059 while (m)
1060 m = m_free(m);
c6339e39 1061 crit_exit();
984263bc
MD
1062}
1063
1064/*
df80f2ea 1065 * mbuf utility routines
984263bc
MD
1066 */
1067
1068/*
1069 * Lesser-used path for M_PREPEND:
1070 * allocate new mbuf to prepend to chain,
1071 * copy junk along.
1072 */
1073struct mbuf *
8a3125c6 1074m_prepend(struct mbuf *m, int len, int how)
984263bc
MD
1075{
1076 struct mbuf *mn;
1077
1078 MGET(mn, how, m->m_type);
1079 if (mn == (struct mbuf *)NULL) {
1080 m_freem(m);
1081 return ((struct mbuf *)NULL);
1082 }
1083 if (m->m_flags & M_PKTHDR)
1084 M_MOVE_PKTHDR(mn, m);
1085 mn->m_next = m;
1086 m = mn;
1087 if (len < MHLEN)
1088 MH_ALIGN(m, len);
1089 m->m_len = len;
1090 return (m);
1091}
1092
1093/*
1094 * Make a copy of an mbuf chain starting "off0" bytes from the beginning,
1095 * continuing for "len" bytes. If len is M_COPYALL, copy to end of mbuf.
74f1caca 1096 * The wait parameter is a choice of MB_WAIT/MB_DONTWAIT from caller.
984263bc
MD
1097 * Note that the copy is read-only, because clusters are not copied,
1098 * only their reference counts are incremented.
1099 */
1100#define MCFail (mbstat.m_mcfail)
1101
1102struct mbuf *
8a3125c6 1103m_copym(const struct mbuf *m, int off0, int len, int wait)
984263bc 1104{
1fd87d54
RG
1105 struct mbuf *n, **np;
1106 int off = off0;
984263bc
MD
1107 struct mbuf *top;
1108 int copyhdr = 0;
1109
1110 KASSERT(off >= 0, ("m_copym, negative off %d", off));
1111 KASSERT(len >= 0, ("m_copym, negative len %d", len));
1112 if (off == 0 && m->m_flags & M_PKTHDR)
1113 copyhdr = 1;
1114 while (off > 0) {
1115 KASSERT(m != NULL, ("m_copym, offset > size of mbuf chain"));
1116 if (off < m->m_len)
1117 break;
1118 off -= m->m_len;
1119 m = m->m_next;
1120 }
1121 np = &top;
1122 top = 0;
1123 while (len > 0) {
1124 if (m == 0) {
1125 KASSERT(len == M_COPYALL,
1126 ("m_copym, length > size of mbuf chain"));
1127 break;
1128 }
1129 MGET(n, wait, m->m_type);
1130 *np = n;
1131 if (n == 0)
1132 goto nospace;
1133 if (copyhdr) {
1134 if (!m_dup_pkthdr(n, m, wait))
1135 goto nospace;
1136 if (len == M_COPYALL)
1137 n->m_pkthdr.len -= off0;
1138 else
1139 n->m_pkthdr.len = len;
1140 copyhdr = 0;
1141 }
1142 n->m_len = min(len, m->m_len - off);
1143 if (m->m_flags & M_EXT) {
1144 n->m_data = m->m_data + off;
7eccf245 1145 m_extref(m);
984263bc 1146 n->m_ext = m->m_ext;
2915401a
MD
1147 n->m_flags |= m->m_flags &
1148 (M_EXT | M_EXT_OLD | M_EXT_CLUSTER);
7eccf245 1149 } else {
984263bc
MD
1150 bcopy(mtod(m, caddr_t)+off, mtod(n, caddr_t),
1151 (unsigned)n->m_len);
7eccf245 1152 }
984263bc
MD
1153 if (len != M_COPYALL)
1154 len -= n->m_len;
1155 off = 0;
1156 m = m->m_next;
1157 np = &n->m_next;
1158 }
1159 if (top == 0)
1160 MCFail++;
1161 return (top);
1162nospace:
1163 m_freem(top);
1164 MCFail++;
1165 return (0);
1166}
1167
1168/*
1169 * Copy an entire packet, including header (which must be present).
1170 * An optimization of the common case `m_copym(m, 0, M_COPYALL, how)'.
1171 * Note that the copy is read-only, because clusters are not copied,
1172 * only their reference counts are incremented.
1173 * Preserve alignment of the first mbuf so if the creator has left
1174 * some room at the beginning (e.g. for inserting protocol headers)
1175 * the copies also have the room available.
1176 */
1177struct mbuf *
8a3125c6 1178m_copypacket(struct mbuf *m, int how)
984263bc
MD
1179{
1180 struct mbuf *top, *n, *o;
1181
1182 MGET(n, how, m->m_type);
1183 top = n;
1184 if (!n)
1185 goto nospace;
1186
1187 if (!m_dup_pkthdr(n, m, how))
1188 goto nospace;
1189 n->m_len = m->m_len;
1190 if (m->m_flags & M_EXT) {
1191 n->m_data = m->m_data;
7eccf245 1192 m_extref(m);
984263bc 1193 n->m_ext = m->m_ext;
2915401a 1194 n->m_flags |= m->m_flags & (M_EXT | M_EXT_OLD | M_EXT_CLUSTER);
984263bc
MD
1195 } else {
1196 n->m_data = n->m_pktdat + (m->m_data - m->m_pktdat );
1197 bcopy(mtod(m, char *), mtod(n, char *), n->m_len);
1198 }
1199
1200 m = m->m_next;
1201 while (m) {
1202 MGET(o, how, m->m_type);
1203 if (!o)
1204 goto nospace;
1205
1206 n->m_next = o;
1207 n = n->m_next;
1208
1209 n->m_len = m->m_len;
1210 if (m->m_flags & M_EXT) {
1211 n->m_data = m->m_data;
7eccf245 1212 m_extref(m);
984263bc 1213 n->m_ext = m->m_ext;
2915401a
MD
1214 n->m_flags |= m->m_flags &
1215 (M_EXT | M_EXT_OLD | M_EXT_CLUSTER);
984263bc
MD
1216 } else {
1217 bcopy(mtod(m, char *), mtod(n, char *), n->m_len);
1218 }
1219
1220 m = m->m_next;
1221 }
1222 return top;
1223nospace:
1224 m_freem(top);
1225 MCFail++;
1226 return 0;
1227}
1228
1229/*
1230 * Copy data from an mbuf chain starting "off" bytes from the beginning,
1231 * continuing for "len" bytes, into the indicated buffer.
1232 */
1233void
8a3125c6 1234m_copydata(const struct mbuf *m, int off, int len, caddr_t cp)
984263bc 1235{
1fd87d54 1236 unsigned count;
984263bc
MD
1237
1238 KASSERT(off >= 0, ("m_copydata, negative off %d", off));
1239 KASSERT(len >= 0, ("m_copydata, negative len %d", len));
1240 while (off > 0) {
1241 KASSERT(m != NULL, ("m_copydata, offset > size of mbuf chain"));
1242 if (off < m->m_len)
1243 break;
1244 off -= m->m_len;
1245 m = m->m_next;
1246 }
1247 while (len > 0) {
1248 KASSERT(m != NULL, ("m_copydata, length > size of mbuf chain"));
1249 count = min(m->m_len - off, len);
1250 bcopy(mtod(m, caddr_t) + off, cp, count);
1251 len -= count;
1252 cp += count;
1253 off = 0;
1254 m = m->m_next;
1255 }
1256}
1257
1258/*
1259 * Copy a packet header mbuf chain into a completely new chain, including
1260 * copying any mbuf clusters. Use this instead of m_copypacket() when
1261 * you need a writable copy of an mbuf chain.
1262 */
1263struct mbuf *
8a3125c6 1264m_dup(struct mbuf *m, int how)
984263bc
MD
1265{
1266 struct mbuf **p, *top = NULL;
1267 int remain, moff, nsize;
1268
1269 /* Sanity check */
1270 if (m == NULL)
50503f0f 1271 return (NULL);
5e2195bf 1272 KASSERT((m->m_flags & M_PKTHDR) != 0, ("%s: !PKTHDR", __func__));
984263bc
MD
1273
1274 /* While there's more data, get a new mbuf, tack it on, and fill it */
1275 remain = m->m_pkthdr.len;
1276 moff = 0;
1277 p = &top;
1278 while (remain > 0 || top == NULL) { /* allow m->m_pkthdr.len == 0 */
1279 struct mbuf *n;
1280
1281 /* Get the next new mbuf */
50503f0f
JH
1282 n = m_getl(remain, how, m->m_type, top == NULL ? M_PKTHDR : 0,
1283 &nsize);
984263bc
MD
1284 if (n == NULL)
1285 goto nospace;
50503f0f 1286 if (top == NULL)
984263bc 1287 if (!m_dup_pkthdr(n, m, how))
50503f0f 1288 goto nospace0;
984263bc
MD
1289
1290 /* Link it into the new chain */
1291 *p = n;
1292 p = &n->m_next;
1293
1294 /* Copy data from original mbuf(s) into new mbuf */
50503f0f 1295 n->m_len = 0;
984263bc
MD
1296 while (n->m_len < nsize && m != NULL) {
1297 int chunk = min(nsize - n->m_len, m->m_len - moff);
1298
1299 bcopy(m->m_data + moff, n->m_data + n->m_len, chunk);
1300 moff += chunk;
1301 n->m_len += chunk;
1302 remain -= chunk;
1303 if (moff == m->m_len) {
1304 m = m->m_next;
1305 moff = 0;
1306 }
1307 }
1308
1309 /* Check correct total mbuf length */
1310 KASSERT((remain > 0 && m != NULL) || (remain == 0 && m == NULL),
50503f0f 1311 ("%s: bogus m_pkthdr.len", __func__));
984263bc
MD
1312 }
1313 return (top);
1314
1315nospace:
1316 m_freem(top);
50503f0f
JH
1317nospace0:
1318 mbstat.m_mcfail++;
1319 return (NULL);
984263bc
MD
1320}
1321
1322/*
1323 * Concatenate mbuf chain n to m.
1324 * Both chains must be of the same type (e.g. MT_DATA).
1325 * Any m_pkthdr is not updated.
1326 */
1327void
8a3125c6 1328m_cat(struct mbuf *m, struct mbuf *n)
984263bc 1329{
50503f0f 1330 m = m_last(m);
984263bc
MD
1331 while (n) {
1332 if (m->m_flags & M_EXT ||
1333 m->m_data + m->m_len + n->m_len >= &m->m_dat[MLEN]) {
1334 /* just join the two chains */
1335 m->m_next = n;
1336 return;
1337 }
1338 /* splat the data from one into the other */
1339 bcopy(mtod(n, caddr_t), mtod(m, caddr_t) + m->m_len,
1340 (u_int)n->m_len);
1341 m->m_len += n->m_len;
1342 n = m_free(n);
1343 }
1344}
1345
1346void
8a3125c6 1347m_adj(struct mbuf *mp, int req_len)
984263bc 1348{
1fd87d54
RG
1349 int len = req_len;
1350 struct mbuf *m;
1351 int count;
984263bc
MD
1352
1353 if ((m = mp) == NULL)
1354 return;
1355 if (len >= 0) {
1356 /*
1357 * Trim from head.
1358 */
1359 while (m != NULL && len > 0) {
1360 if (m->m_len <= len) {
1361 len -= m->m_len;
1362 m->m_len = 0;
1363 m = m->m_next;
1364 } else {
1365 m->m_len -= len;
1366 m->m_data += len;
1367 len = 0;
1368 }
1369 }
1370 m = mp;
1371 if (mp->m_flags & M_PKTHDR)
1372 m->m_pkthdr.len -= (req_len - len);
1373 } else {
1374 /*
1375 * Trim from tail. Scan the mbuf chain,
1376 * calculating its length and finding the last mbuf.
1377 * If the adjustment only affects this mbuf, then just
1378 * adjust and return. Otherwise, rescan and truncate
1379 * after the remaining size.
1380 */
1381 len = -len;
1382 count = 0;
1383 for (;;) {
1384 count += m->m_len;
1385 if (m->m_next == (struct mbuf *)0)
1386 break;
1387 m = m->m_next;
1388 }
1389 if (m->m_len >= len) {
1390 m->m_len -= len;
1391 if (mp->m_flags & M_PKTHDR)
1392 mp->m_pkthdr.len -= len;
1393 return;
1394 }
1395 count -= len;
1396 if (count < 0)
1397 count = 0;
1398 /*
1399 * Correct length for chain is "count".
1400 * Find the mbuf with last data, adjust its length,
1401 * and toss data from remaining mbufs on chain.
1402 */
1403 m = mp;
1404 if (m->m_flags & M_PKTHDR)
1405 m->m_pkthdr.len = count;
1406 for (; m; m = m->m_next) {
1407 if (m->m_len >= count) {
1408 m->m_len = count;
1409 break;
1410 }
1411 count -= m->m_len;
1412 }
1413 while (m->m_next)
1414 (m = m->m_next) ->m_len = 0;
1415 }
1416}
1417
1418/*
1419 * Rearange an mbuf chain so that len bytes are contiguous
9e4465af
MD
1420 * and in the data area of an mbuf (so that mtod will work for a structure
1421 * of size len). Returns the resulting mbuf chain on success, frees it and
1422 * returns null on failure. If there is room, it will add up to
1423 * max_protohdr-len extra bytes to the contiguous region in an attempt to
1424 * avoid being called next time.
984263bc
MD
1425 */
1426#define MPFail (mbstat.m_mpfail)
1427
1428struct mbuf *
8a3125c6 1429m_pullup(struct mbuf *n, int len)
984263bc 1430{
1fd87d54
RG
1431 struct mbuf *m;
1432 int count;
984263bc
MD
1433 int space;
1434
1435 /*
1436 * If first mbuf has no cluster, and has room for len bytes
1437 * without shifting current data, pullup into it,
1438 * otherwise allocate a new mbuf to prepend to the chain.
1439 */
1440 if ((n->m_flags & M_EXT) == 0 &&
1441 n->m_data + len < &n->m_dat[MLEN] && n->m_next) {
1442 if (n->m_len >= len)
1443 return (n);
1444 m = n;
1445 n = n->m_next;
1446 len -= m->m_len;
1447 } else {
1448 if (len > MHLEN)
1449 goto bad;
74f1caca 1450 MGET(m, MB_DONTWAIT, n->m_type);
984263bc
MD
1451 if (m == 0)
1452 goto bad;
1453 m->m_len = 0;
1454 if (n->m_flags & M_PKTHDR)
1455 M_MOVE_PKTHDR(m, n);
1456 }
1457 space = &m->m_dat[MLEN] - (m->m_data + m->m_len);
1458 do {
1459 count = min(min(max(len, max_protohdr), space), n->m_len);
1460 bcopy(mtod(n, caddr_t), mtod(m, caddr_t) + m->m_len,
1461 (unsigned)count);
1462 len -= count;
1463 m->m_len += count;
1464 n->m_len -= count;
1465 space -= count;
1466 if (n->m_len)
1467 n->m_data += count;
1468 else
1469 n = m_free(n);
1470 } while (len > 0 && n);
1471 if (len > 0) {
1472 (void) m_free(m);
1473 goto bad;
1474 }
1475 m->m_next = n;
1476 return (m);
1477bad:
1478 m_freem(n);
1479 MPFail++;
1480 return (0);
1481}
1482
1483/*
1484 * Partition an mbuf chain in two pieces, returning the tail --
1485 * all but the first len0 bytes. In case of failure, it returns NULL and
1486 * attempts to restore the chain to its original state.
1487 *
1488 * Note that the resulting mbufs might be read-only, because the new
1489 * mbuf can end up sharing an mbuf cluster with the original mbuf if
1490 * the "breaking point" happens to lie within a cluster mbuf. Use the
1491 * M_WRITABLE() macro to check for this case.
1492 */
1493struct mbuf *
8a3125c6 1494m_split(struct mbuf *m0, int len0, int wait)
984263bc 1495{
1fd87d54 1496 struct mbuf *m, *n;
984263bc
MD
1497 unsigned len = len0, remain;
1498
1499 for (m = m0; m && len > m->m_len; m = m->m_next)
1500 len -= m->m_len;
1501 if (m == 0)
1502 return (0);
1503 remain = m->m_len - len;
1504 if (m0->m_flags & M_PKTHDR) {
1505 MGETHDR(n, wait, m0->m_type);
1506 if (n == 0)
1507 return (0);
1508 n->m_pkthdr.rcvif = m0->m_pkthdr.rcvif;
1509 n->m_pkthdr.len = m0->m_pkthdr.len - len0;
1510 m0->m_pkthdr.len = len0;
1511 if (m->m_flags & M_EXT)
1512 goto extpacket;
1513 if (remain > MHLEN) {
1514 /* m can't be the lead packet */
1515 MH_ALIGN(n, 0);
1516 n->m_next = m_split(m, len, wait);
1517 if (n->m_next == 0) {
1518 (void) m_free(n);
1519 return (0);
1520 } else {
1521 n->m_len = 0;
1522 return (n);
1523 }
1524 } else
1525 MH_ALIGN(n, remain);
1526 } else if (remain == 0) {
1527 n = m->m_next;
1528 m->m_next = 0;
1529 return (n);
1530 } else {
1531 MGET(n, wait, m->m_type);
1532 if (n == 0)
1533 return (0);
1534 M_ALIGN(n, remain);
1535 }
1536extpacket:
1537 if (m->m_flags & M_EXT) {
984263bc 1538 n->m_data = m->m_data + len;
7eccf245
MD
1539 m_extref(m);
1540 n->m_ext = m->m_ext;
2915401a 1541 n->m_flags |= m->m_flags & (M_EXT | M_EXT_OLD | M_EXT_CLUSTER);
984263bc
MD
1542 } else {
1543 bcopy(mtod(m, caddr_t) + len, mtod(n, caddr_t), remain);
1544 }
1545 n->m_len = remain;
1546 m->m_len = len;
1547 n->m_next = m->m_next;
1548 m->m_next = 0;
1549 return (n);
1550}
50503f0f 1551
984263bc
MD
1552/*
1553 * Routine to copy from device local memory into mbufs.
50503f0f 1554 * Note: "offset" is ill-defined and always called as 0, so ignore it.
984263bc
MD
1555 */
1556struct mbuf *
50503f0f
JH
1557m_devget(char *buf, int len, int offset, struct ifnet *ifp,
1558 void (*copy)(volatile const void *from, volatile void *to, size_t length))
984263bc 1559{
50503f0f
JH
1560 struct mbuf *m, *mfirst = NULL, **mtail;
1561 int nsize, flags;
1562
1563 if (copy == NULL)
1564 copy = bcopy;
1565 mtail = &mfirst;
1566 flags = M_PKTHDR;
1567
1568 while (len > 0) {
1569 m = m_getl(len, MB_DONTWAIT, MT_DATA, flags, &nsize);
1570 if (m == NULL) {
1571 m_freem(mfirst);
1572 return (NULL);
984263bc 1573 }
50503f0f
JH
1574 m->m_len = min(len, nsize);
1575
1576 if (flags & M_PKTHDR) {
1577 if (len + max_linkhdr <= nsize)
1578 m->m_data += max_linkhdr;
1579 m->m_pkthdr.rcvif = ifp;
1580 m->m_pkthdr.len = len;
1581 flags = 0;
984263bc 1582 }
50503f0f
JH
1583
1584 copy(buf, m->m_data, (unsigned)m->m_len);
1585 buf += m->m_len;
1586 len -= m->m_len;
1587 *mtail = m;
1588 mtail = &m->m_next;
984263bc 1589 }
50503f0f
JH
1590
1591 return (mfirst);
984263bc
MD
1592}
1593
1594/*
1595 * Copy data from a buffer back into the indicated mbuf chain,
1596 * starting "off" bytes from the beginning, extending the mbuf
1597 * chain if necessary.
1598 */
1599void
8a3125c6 1600m_copyback(struct mbuf *m0, int off, int len, caddr_t cp)
984263bc 1601{
1fd87d54
RG
1602 int mlen;
1603 struct mbuf *m = m0, *n;
984263bc
MD
1604 int totlen = 0;
1605
1606 if (m0 == 0)
1607 return;
1608 while (off > (mlen = m->m_len)) {
1609 off -= mlen;
1610 totlen += mlen;
1611 if (m->m_next == 0) {
74f1caca 1612 n = m_getclr(MB_DONTWAIT, m->m_type);
984263bc
MD
1613 if (n == 0)
1614 goto out;
1615 n->m_len = min(MLEN, len + off);
1616 m->m_next = n;
1617 }
1618 m = m->m_next;
1619 }
1620 while (len > 0) {
1621 mlen = min (m->m_len - off, len);
1622 bcopy(cp, off + mtod(m, caddr_t), (unsigned)mlen);
1623 cp += mlen;
1624 len -= mlen;
1625 mlen += off;
1626 off = 0;
1627 totlen += mlen;
1628 if (len == 0)
1629 break;
1630 if (m->m_next == 0) {
74f1caca 1631 n = m_get(MB_DONTWAIT, m->m_type);
984263bc
MD
1632 if (n == 0)
1633 break;
1634 n->m_len = min(MLEN, len);
1635 m->m_next = n;
1636 }
1637 m = m->m_next;
1638 }
1639out: if (((m = m0)->m_flags & M_PKTHDR) && (m->m_pkthdr.len < totlen))
1640 m->m_pkthdr.len = totlen;
1641}
1642
1643void
1644m_print(const struct mbuf *m)
1645{
1646 int len;
1647 const struct mbuf *m2;
1648
1649 len = m->m_pkthdr.len;
1650 m2 = m;
1651 while (len) {
1652 printf("%p %*D\n", m2, m2->m_len, (u_char *)m2->m_data, "-");
1653 len -= m2->m_len;
1654 m2 = m2->m_next;
1655 }
1656 return;
1657}
1658
1659/*
1660 * "Move" mbuf pkthdr from "from" to "to".
1661 * "from" must have M_PKTHDR set, and "to" must be empty.
1662 */
1663void
1664m_move_pkthdr(struct mbuf *to, struct mbuf *from)
1665{
1666 KASSERT((to->m_flags & M_EXT) == 0, ("m_move_pkthdr: to has cluster"));
1667
1668 to->m_flags = from->m_flags & M_COPYFLAGS;
1669 to->m_data = to->m_pktdat;
1670 to->m_pkthdr = from->m_pkthdr; /* especially tags */
1671 SLIST_INIT(&from->m_pkthdr.tags); /* purge tags from src */
1672 from->m_flags &= ~M_PKTHDR;
1673}
1674
1675/*
1676 * Duplicate "from"'s mbuf pkthdr in "to".
1677 * "from" must have M_PKTHDR set, and "to" must be empty.
1678 * In particular, this does a deep copy of the packet tags.
1679 */
1680int
f15db79e 1681m_dup_pkthdr(struct mbuf *to, const struct mbuf *from, int how)
984263bc
MD
1682{
1683 to->m_flags = (from->m_flags & M_COPYFLAGS) | (to->m_flags & M_EXT);
1684 if ((to->m_flags & M_EXT) == 0)
1685 to->m_data = to->m_pktdat;
1686 to->m_pkthdr = from->m_pkthdr;
1687 SLIST_INIT(&to->m_pkthdr.tags);
1688 return (m_tag_copy_chain(to, from, how));
1689}
1690
1691/*
1692 * Defragment a mbuf chain, returning the shortest possible
1693 * chain of mbufs and clusters. If allocation fails and
1694 * this cannot be completed, NULL will be returned, but
1695 * the passed in chain will be unchanged. Upon success,
1696 * the original chain will be freed, and the new chain
1697 * will be returned.
1698 *
1699 * If a non-packet header is passed in, the original
1700 * mbuf (chain?) will be returned unharmed.
c8f5127a
JS
1701 *
1702 * m_defrag_nofree doesn't free the passed in mbuf.
984263bc
MD
1703 */
1704struct mbuf *
1705m_defrag(struct mbuf *m0, int how)
c8f5127a
JS
1706{
1707 struct mbuf *m_new;
1708
1709 if ((m_new = m_defrag_nofree(m0, how)) == NULL)
1710 return (NULL);
1711 if (m_new != m0)
1712 m_freem(m0);
1713 return (m_new);
1714}
1715
1716struct mbuf *
1717m_defrag_nofree(struct mbuf *m0, int how)
984263bc
MD
1718{
1719 struct mbuf *m_new = NULL, *m_final = NULL;
1720 int progress = 0, length;
1721
1722 if (!(m0->m_flags & M_PKTHDR))
1723 return (m0);
1724
1725#ifdef MBUF_STRESS_TEST
1726 if (m_defragrandomfailures) {
1727 int temp = arc4random() & 0xff;
1728 if (temp == 0xba)
1729 goto nospace;
1730 }
1731#endif
1732
1733 if (m0->m_pkthdr.len > MHLEN)
1734 m_final = m_getcl(how, MT_DATA, M_PKTHDR);
1735 else
1736 m_final = m_gethdr(how, MT_DATA);
1737
1738 if (m_final == NULL)
1739 goto nospace;
1740
1741 if (m_dup_pkthdr(m_final, m0, how) == NULL)
1742 goto nospace;
1743
1744 m_new = m_final;
1745
1746 while (progress < m0->m_pkthdr.len) {
1747 length = m0->m_pkthdr.len - progress;
1748 if (length > MCLBYTES)
1749 length = MCLBYTES;
1750
1751 if (m_new == NULL) {
1752 if (length > MLEN)
1753 m_new = m_getcl(how, MT_DATA, 0);
1754 else
1755 m_new = m_get(how, MT_DATA);
1756 if (m_new == NULL)
1757 goto nospace;
1758 }
1759
1760 m_copydata(m0, progress, length, mtod(m_new, caddr_t));
1761 progress += length;
1762 m_new->m_len = length;
1763 if (m_new != m_final)
1764 m_cat(m_final, m_new);
1765 m_new = NULL;
1766 }
1767 if (m0->m_next == NULL)
1768 m_defraguseless++;
984263bc 1769 m_defragpackets++;
c8f5127a
JS
1770 m_defragbytes += m_final->m_pkthdr.len;
1771 return (m_final);
984263bc
MD
1772nospace:
1773 m_defragfailure++;
1774 if (m_new)
1775 m_free(m_new);
1776 if (m_final)
1777 m_freem(m_final);
1778 return (NULL);
1779}
0c33f36d
JH
1780
1781/*
1782 * Move data from uio into mbufs.
1783 * A length of zero means copy the whole uio.
1784 */
1785struct mbuf *
1786m_uiomove(struct uio *uio, int wait, int len0)
1787{
1788 struct mbuf *head; /* result mbuf chain */
1789 struct mbuf *m; /* current working mbuf */
1790 struct mbuf **mp;
1791 int resid, datalen, error;
1792
1793 resid = (len0 == 0) ? uio->uio_resid : min(len0, uio->uio_resid);
1794
1795 head = NULL;
1796 mp = &head;
1797 do {
1798 if (resid > MHLEN) {
1799 m = m_getcl(wait, MT_DATA, head == NULL ? M_PKTHDR : 0);
1800 if (m == NULL)
1801 goto failed;
1802 if (m->m_flags & M_PKTHDR)
1803 m->m_pkthdr.len = 0;
1804 } else {
1805 if (head == NULL) {
1806 MGETHDR(m, wait, MT_DATA);
1807 if (m == NULL)
1808 goto failed;
1809 m->m_pkthdr.len = 0;
1810 /* Leave room for protocol headers. */
1811 if (resid < MHLEN)
1812 MH_ALIGN(m, resid);
1813 } else {
1814 MGET(m, wait, MT_DATA);
1815 if (m == NULL)
1816 goto failed;
1817 }
1818 }
1819 datalen = min(MCLBYTES, resid);
1820 error = uiomove(mtod(m, caddr_t), datalen, uio);
1821 if (error) {
1822 m_free(m);
1823 goto failed;
1824 }
1825 m->m_len = datalen;
1826 *mp = m;
1827 mp = &m->m_next;
1828 head->m_pkthdr.len += datalen;
1829 resid -= datalen;
1830 } while (resid > 0);
1831
1832 return (head);
1833
1834failed:
1835 if (head)
1836 m_freem(head);
1837 return (NULL);
1838}
df80f2ea 1839
50503f0f
JH
1840struct mbuf *
1841m_last(struct mbuf *m)
1842{
1843 while (m->m_next)
1844 m = m->m_next;
1845 return (m);
1846}
1847
df80f2ea
JH
1848/*
1849 * Return the number of bytes in an mbuf chain.
1850 * If lastm is not NULL, also return the last mbuf.
1851 */
1852u_int
1853m_lengthm(struct mbuf *m, struct mbuf **lastm)
1854{
1855 u_int len = 0;
1856 struct mbuf *prev = m;
1857
1858 while (m) {
1859 len += m->m_len;
1860 prev = m;
1861 m = m->m_next;
1862 }
1863 if (lastm != NULL)
1864 *lastm = prev;
1865 return (len);
1866}
1867
1868/*
1869 * Like m_lengthm(), except also keep track of mbuf usage.
1870 */
1871u_int
1872m_countm(struct mbuf *m, struct mbuf **lastm, u_int *pmbcnt)
1873{
1874 u_int len = 0, mbcnt = 0;
1875 struct mbuf *prev = m;
1876
1877 while (m) {
1878 len += m->m_len;
1879 mbcnt += MSIZE;
1880 if (m->m_flags & M_EXT)
1881 mbcnt += m->m_ext.ext_size;
1882 prev = m;
1883 m = m->m_next;
1884 }
1885 if (lastm != NULL)
1886 *lastm = prev;
1887 *pmbcnt = mbcnt;
1888 return (len);
1889}