Remove PC98 loader.
[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 $
5e2195bf 85 * $DragonFly: src/sys/kern/uipc_mbuf.c,v 1.33 2005/02/17 13:59:36 joerg Exp $
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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
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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
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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,
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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.
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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.
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284 */
285 if ((nmb + mbstat.m_mbufs) > nmbufs)
286 return (0);
287
288 /*
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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);
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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
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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);
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341 break;
342 case MGETHDR_C:
90775e29 343 MGETHDR(m, MB_DONTWAIT, type);
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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);
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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)
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374 printf("m_clalloc failed even in thread context!\n");
375 --i_want_my_mcl;
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376 }
377 }
90775e29 378 /* not reached */
c6339e39 379 crit_exit();
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380}
381
bc6dffab 382static struct thread *mclallocthread;
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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,
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389 &mclalloc_kp);
390#endif
391
392/*
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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{
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401 static int last_report;
402 mbcluster_t mcl;
403 void *data;
1fd87d54 404 int i;
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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;
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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 */
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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
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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
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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
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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
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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 /*
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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) {
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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/*
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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
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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
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497m_clalloc_wait(void)
498{
984263bc 499 /* If in interrupt context, and INVARIANTS, maintain sanity and die. */
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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 /*
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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);
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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;
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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"));
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575 m_reclaim();
576 }
577
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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);
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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();
8a3125c6
MD
681 for (dp = domains; dp; dp = dp->dom_next) {
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/*
833 * struct mbuf *
834 * m_getm(m, len, how, type)
835 *
836 * This will allocate len-worth of mbufs and/or mbuf clusters (whatever fits
837 * best) and return a pointer to the top of the allocated chain. If m is
838 * non-null, then we assume that it is a single mbuf or an mbuf chain to
839 * which we want len bytes worth of mbufs and/or clusters attached, and so
840 * if we succeed in allocating it, we will just return a pointer to m.
841 *
842 * If we happen to fail at any point during the allocation, we will free
843 * up everything we have already allocated and return NULL.
844 *
845 */
846struct mbuf *
847m_getm(struct mbuf *m, int len, int how, int type)
848{
849 struct mbuf *top, *tail, *mp, *mtail = NULL;
850
851 KASSERT(len >= 0, ("len is < 0 in m_getm"));
852
90775e29
MD
853 mp = m_get(how, type);
854 if (mp == NULL) {
984263bc 855 return (NULL);
90775e29
MD
856 } else if (len > MINCLSIZE) {
857 m_mclget(mp, how);
984263bc
MD
858 if ((mp->m_flags & M_EXT) == 0) {
859 m_free(mp);
860 return (NULL);
861 }
862 }
863 mp->m_len = 0;
864 len -= M_TRAILINGSPACE(mp);
865
90775e29
MD
866 if (m != NULL) {
867 for (mtail = m; mtail->m_next != NULL; mtail = mtail->m_next)
868 ;
869 } else {
984263bc 870 m = mp;
90775e29 871 }
984263bc
MD
872
873 top = tail = mp;
874 while (len > 0) {
90775e29 875 mp = m_get(how, type);
984263bc
MD
876 if (mp == NULL)
877 goto failed;
878
879 tail->m_next = mp;
880 tail = mp;
881 if (len > MINCLSIZE) {
90775e29 882 m_mclget(mp, how);
984263bc
MD
883 if ((mp->m_flags & M_EXT) == 0)
884 goto failed;
885 }
886
887 mp->m_len = 0;
888 len -= M_TRAILINGSPACE(mp);
889 }
890
891 if (mtail != NULL)
892 mtail->m_next = top;
893 return (m);
984263bc
MD
894failed:
895 m_freem(top);
896 return (NULL);
897}
898
899/*
90775e29 900 * m_mclget() - Adds a cluster to a normal mbuf, M_EXT is set on success.
b6650ec0 901 */
90775e29
MD
902void
903m_mclget(struct mbuf *m, int how)
b6650ec0 904{
90775e29 905 mbcluster_t mcl;
b6650ec0 906
90775e29 907 KKASSERT((m->m_flags & M_EXT_OLD) == 0);
b6650ec0 908
c6339e39
MD
909 /*
910 * Allocate a cluster, return if we can't get one.
911 */
912 crit_enter();
90775e29 913 if ((mcl = mclfree) == NULL) {
b6650ec0 914 m_clalloc(1, how);
90775e29
MD
915 if ((mcl = mclfree) == NULL) {
916 if (how == MB_WAIT) {
917 m_clalloc_wait();
918 mcl = mclfree;
919 }
c6339e39
MD
920 if (mcl == NULL) {
921 crit_exit();
922 return;
923 }
90775e29
MD
924 }
925 }
926
927 /*
c6339e39
MD
928 * We have a cluster, unlink it from the free list and set the ref
929 * count.
90775e29 930 */
90775e29
MD
931 KKASSERT(mcl->mcl_refs == 0);
932 mclfree = mcl->mcl_next;
933 mcl->mcl_refs = 1;
934 --mbstat.m_clfree;
c6339e39 935 crit_exit();
b6650ec0 936
90775e29 937 /*
c6339e39
MD
938 * Add the cluster to the mbuf. The caller will detect that the
939 * mbuf now has an attached cluster.
90775e29
MD
940 */
941 m->m_ext.ext_arg = mcl;
942 m->m_ext.ext_buf = mcl->mcl_data;
943 m->m_ext.ext_nref.new = m_mclref;
944 m->m_ext.ext_nfree.new = m_mclfree;
945 m->m_ext.ext_size = MCLBYTES;
946
947 m->m_data = m->m_ext.ext_buf;
948 m->m_flags |= M_EXT | M_EXT_CLUSTER;
b6650ec0
MD
949}
950
90775e29
MD
951static void
952m_mclfree(void *arg)
b6650ec0 953{
90775e29
MD
954 mbcluster_t mcl = arg;
955
956 KKASSERT(mcl->mcl_magic == MCL_MAGIC);
957 KKASSERT(mcl->mcl_refs > 0);
958 crit_enter();
959 if (--mcl->mcl_refs == 0) {
960 if (mbstat.m_clfree < mcl_free_max) {
961 mcl->mcl_next = mclfree;
962 mclfree = mcl;
963 ++mbstat.m_clfree;
964 MCLWAKEUP();
965 } else {
966 mcl->mcl_magic = -1;
967 free(mcl->mcl_data, M_MBUFCL);
968 free(mcl, M_MBUFCL);
969 --mbstat.m_clusters;
970 }
b6650ec0 971 }
90775e29 972 crit_exit();
b6650ec0
MD
973}
974
90775e29
MD
975static void
976m_mclref(void *arg)
b6650ec0 977{
90775e29
MD
978 mbcluster_t mcl = arg;
979
980 KKASSERT(mcl->mcl_magic == MCL_MAGIC);
981 crit_enter();
982 ++mcl->mcl_refs;
983 crit_exit();
b6650ec0
MD
984}
985
7eccf245
MD
986/*
987 * Helper routines for M_EXT reference/free
988 */
989static __inline void
990m_extref(const struct mbuf *m)
991{
90775e29 992 KKASSERT(m->m_ext.ext_nfree.any != NULL);
c6339e39 993 crit_enter();
90775e29
MD
994 if (m->m_flags & M_EXT_OLD)
995 m->m_ext.ext_nref.old(m->m_ext.ext_buf, m->m_ext.ext_size);
996 else
997 m->m_ext.ext_nref.new(m->m_ext.ext_arg);
c6339e39 998 crit_exit();
7eccf245
MD
999}
1000
b6650ec0
MD
1001/*
1002 * m_free()
1003 *
1004 * Free a single mbuf and any associated external storage. The successor,
1005 * if any, is returned.
984263bc 1006 *
b6650ec0 1007 * We do need to check non-first mbuf for m_aux, since some of existing
984263bc
MD
1008 * code does not call M_PREPEND properly.
1009 * (example: call to bpf_mtap from drivers)
1010 */
984263bc 1011struct mbuf *
b6650ec0 1012m_free(struct mbuf *m)
984263bc 1013{
b6650ec0
MD
1014 struct mbuf *n;
1015
c6339e39 1016 crit_enter();
361af367 1017 KASSERT(m->m_type != MT_FREE, ("freeing free mbuf %p", m));
90775e29
MD
1018
1019 /*
1020 * Adjust our type count and delete any attached chains if the
1021 * mbuf is a packet header.
1022 */
b6650ec0
MD
1023 if ((m->m_flags & M_PKTHDR) != 0)
1024 m_tag_delete_chain(m, NULL);
90775e29
MD
1025
1026 /*
1027 * Place the mbuf on the appropriate free list. Try to maintain a
1028 * small cache of mbuf+cluster pairs.
1029 */
1030 n = m->m_next;
1031 m->m_next = NULL;
b6650ec0 1032 if (m->m_flags & M_EXT) {
90775e29
MD
1033 KKASSERT(m->m_ext.ext_nfree.any != NULL);
1034 if (mcl_pool_count < mcl_pool_max && m && m->m_next == NULL &&
1035 (m->m_flags & (M_PKTHDR|M_EXT_CLUSTER)) == (M_PKTHDR|M_EXT_CLUSTER) &&
1036 m->m_type == MT_DATA && M_EXT_WRITABLE(m) ) {
1037 KKASSERT(((mbcluster_t)m->m_ext.ext_arg)->mcl_magic == MCL_MAGIC);
1038 m->m_nextpkt = mcl_pool;
1039 mcl_pool = m;
1040 ++mcl_pool_count;
1041 m = NULL;
1042 } else {
1043 if (m->m_flags & M_EXT_OLD)
1044 m->m_ext.ext_nfree.old(m->m_ext.ext_buf, m->m_ext.ext_size);
1045 else
1046 m->m_ext.ext_nfree.new(m->m_ext.ext_arg);
1047 m->m_flags = 0;
1048 m->m_ext.ext_arg = NULL;
1049 m->m_ext.ext_nref.new = NULL;
1050 m->m_ext.ext_nfree.new = NULL;
1051 }
1052 }
1053 if (m) {
1054 --mbtypes[m->m_type];
1055 if (mbtypes[MT_FREE] < mbuf_free_max) {
1056 m->m_type = MT_FREE;
1057 mbtypes[MT_FREE]++;
1058 m->m_next = mmbfree;
1059 mmbfree = m;
1060 MMBWAKEUP();
1061 } else {
1062 free(m, M_MBUF);
1063 --mbstat.m_mbufs;
1064 }
b6650ec0 1065 }
c6339e39 1066 crit_exit();
984263bc
MD
1067 return (n);
1068}
1069
1070void
b6650ec0 1071m_freem(struct mbuf *m)
984263bc 1072{
c6339e39 1073 crit_enter();
90775e29
MD
1074 while (m)
1075 m = m_free(m);
c6339e39 1076 crit_exit();
984263bc
MD
1077}
1078
1079/*
1080 * Mbuffer utility routines.
1081 */
1082
1083/*
1084 * Lesser-used path for M_PREPEND:
1085 * allocate new mbuf to prepend to chain,
1086 * copy junk along.
1087 */
1088struct mbuf *
8a3125c6 1089m_prepend(struct mbuf *m, int len, int how)
984263bc
MD
1090{
1091 struct mbuf *mn;
1092
1093 MGET(mn, how, m->m_type);
1094 if (mn == (struct mbuf *)NULL) {
1095 m_freem(m);
1096 return ((struct mbuf *)NULL);
1097 }
1098 if (m->m_flags & M_PKTHDR)
1099 M_MOVE_PKTHDR(mn, m);
1100 mn->m_next = m;
1101 m = mn;
1102 if (len < MHLEN)
1103 MH_ALIGN(m, len);
1104 m->m_len = len;
1105 return (m);
1106}
1107
1108/*
1109 * Make a copy of an mbuf chain starting "off0" bytes from the beginning,
1110 * continuing for "len" bytes. If len is M_COPYALL, copy to end of mbuf.
74f1caca 1111 * The wait parameter is a choice of MB_WAIT/MB_DONTWAIT from caller.
984263bc
MD
1112 * Note that the copy is read-only, because clusters are not copied,
1113 * only their reference counts are incremented.
1114 */
1115#define MCFail (mbstat.m_mcfail)
1116
1117struct mbuf *
8a3125c6 1118m_copym(const struct mbuf *m, int off0, int len, int wait)
984263bc 1119{
1fd87d54
RG
1120 struct mbuf *n, **np;
1121 int off = off0;
984263bc
MD
1122 struct mbuf *top;
1123 int copyhdr = 0;
1124
1125 KASSERT(off >= 0, ("m_copym, negative off %d", off));
1126 KASSERT(len >= 0, ("m_copym, negative len %d", len));
1127 if (off == 0 && m->m_flags & M_PKTHDR)
1128 copyhdr = 1;
1129 while (off > 0) {
1130 KASSERT(m != NULL, ("m_copym, offset > size of mbuf chain"));
1131 if (off < m->m_len)
1132 break;
1133 off -= m->m_len;
1134 m = m->m_next;
1135 }
1136 np = &top;
1137 top = 0;
1138 while (len > 0) {
1139 if (m == 0) {
1140 KASSERT(len == M_COPYALL,
1141 ("m_copym, length > size of mbuf chain"));
1142 break;
1143 }
1144 MGET(n, wait, m->m_type);
1145 *np = n;
1146 if (n == 0)
1147 goto nospace;
1148 if (copyhdr) {
1149 if (!m_dup_pkthdr(n, m, wait))
1150 goto nospace;
1151 if (len == M_COPYALL)
1152 n->m_pkthdr.len -= off0;
1153 else
1154 n->m_pkthdr.len = len;
1155 copyhdr = 0;
1156 }
1157 n->m_len = min(len, m->m_len - off);
1158 if (m->m_flags & M_EXT) {
1159 n->m_data = m->m_data + off;
7eccf245 1160 m_extref(m);
984263bc 1161 n->m_ext = m->m_ext;
2915401a
MD
1162 n->m_flags |= m->m_flags &
1163 (M_EXT | M_EXT_OLD | M_EXT_CLUSTER);
7eccf245 1164 } else {
984263bc
MD
1165 bcopy(mtod(m, caddr_t)+off, mtod(n, caddr_t),
1166 (unsigned)n->m_len);
7eccf245 1167 }
984263bc
MD
1168 if (len != M_COPYALL)
1169 len -= n->m_len;
1170 off = 0;
1171 m = m->m_next;
1172 np = &n->m_next;
1173 }
1174 if (top == 0)
1175 MCFail++;
1176 return (top);
1177nospace:
1178 m_freem(top);
1179 MCFail++;
1180 return (0);
1181}
1182
1183/*
1184 * Copy an entire packet, including header (which must be present).
1185 * An optimization of the common case `m_copym(m, 0, M_COPYALL, how)'.
1186 * Note that the copy is read-only, because clusters are not copied,
1187 * only their reference counts are incremented.
1188 * Preserve alignment of the first mbuf so if the creator has left
1189 * some room at the beginning (e.g. for inserting protocol headers)
1190 * the copies also have the room available.
1191 */
1192struct mbuf *
8a3125c6 1193m_copypacket(struct mbuf *m, int how)
984263bc
MD
1194{
1195 struct mbuf *top, *n, *o;
1196
1197 MGET(n, how, m->m_type);
1198 top = n;
1199 if (!n)
1200 goto nospace;
1201
1202 if (!m_dup_pkthdr(n, m, how))
1203 goto nospace;
1204 n->m_len = m->m_len;
1205 if (m->m_flags & M_EXT) {
1206 n->m_data = m->m_data;
7eccf245 1207 m_extref(m);
984263bc 1208 n->m_ext = m->m_ext;
2915401a 1209 n->m_flags |= m->m_flags & (M_EXT | M_EXT_OLD | M_EXT_CLUSTER);
984263bc
MD
1210 } else {
1211 n->m_data = n->m_pktdat + (m->m_data - m->m_pktdat );
1212 bcopy(mtod(m, char *), mtod(n, char *), n->m_len);
1213 }
1214
1215 m = m->m_next;
1216 while (m) {
1217 MGET(o, how, m->m_type);
1218 if (!o)
1219 goto nospace;
1220
1221 n->m_next = o;
1222 n = n->m_next;
1223
1224 n->m_len = m->m_len;
1225 if (m->m_flags & M_EXT) {
1226 n->m_data = m->m_data;
7eccf245 1227 m_extref(m);
984263bc 1228 n->m_ext = m->m_ext;
2915401a
MD
1229 n->m_flags |= m->m_flags &
1230 (M_EXT | M_EXT_OLD | M_EXT_CLUSTER);
984263bc
MD
1231 } else {
1232 bcopy(mtod(m, char *), mtod(n, char *), n->m_len);
1233 }
1234
1235 m = m->m_next;
1236 }
1237 return top;
1238nospace:
1239 m_freem(top);
1240 MCFail++;
1241 return 0;
1242}
1243
1244/*
1245 * Copy data from an mbuf chain starting "off" bytes from the beginning,
1246 * continuing for "len" bytes, into the indicated buffer.
1247 */
1248void
8a3125c6 1249m_copydata(const struct mbuf *m, int off, int len, caddr_t cp)
984263bc 1250{
1fd87d54 1251 unsigned count;
984263bc
MD
1252
1253 KASSERT(off >= 0, ("m_copydata, negative off %d", off));
1254 KASSERT(len >= 0, ("m_copydata, negative len %d", len));
1255 while (off > 0) {
1256 KASSERT(m != NULL, ("m_copydata, offset > size of mbuf chain"));
1257 if (off < m->m_len)
1258 break;
1259 off -= m->m_len;
1260 m = m->m_next;
1261 }
1262 while (len > 0) {
1263 KASSERT(m != NULL, ("m_copydata, length > size of mbuf chain"));
1264 count = min(m->m_len - off, len);
1265 bcopy(mtod(m, caddr_t) + off, cp, count);
1266 len -= count;
1267 cp += count;
1268 off = 0;
1269 m = m->m_next;
1270 }
1271}
1272
1273/*
1274 * Copy a packet header mbuf chain into a completely new chain, including
1275 * copying any mbuf clusters. Use this instead of m_copypacket() when
1276 * you need a writable copy of an mbuf chain.
1277 */
1278struct mbuf *
8a3125c6 1279m_dup(struct mbuf *m, int how)
984263bc
MD
1280{
1281 struct mbuf **p, *top = NULL;
1282 int remain, moff, nsize;
1283
1284 /* Sanity check */
1285 if (m == NULL)
1286 return (0);
5e2195bf 1287 KASSERT((m->m_flags & M_PKTHDR) != 0, ("%s: !PKTHDR", __func__));
984263bc
MD
1288
1289 /* While there's more data, get a new mbuf, tack it on, and fill it */
1290 remain = m->m_pkthdr.len;
1291 moff = 0;
1292 p = &top;
1293 while (remain > 0 || top == NULL) { /* allow m->m_pkthdr.len == 0 */
1294 struct mbuf *n;
1295
1296 /* Get the next new mbuf */
1297 MGET(n, how, m->m_type);
1298 if (n == NULL)
1299 goto nospace;
1300 if (top == NULL) { /* first one, must be PKTHDR */
1301 if (!m_dup_pkthdr(n, m, how))
1302 goto nospace;
1303 nsize = MHLEN;
1304 } else /* not the first one */
1305 nsize = MLEN;
1306 if (remain >= MINCLSIZE) {
1307 MCLGET(n, how);
1308 if ((n->m_flags & M_EXT) == 0) {
1309 (void)m_free(n);
1310 goto nospace;
1311 }
1312 nsize = MCLBYTES;
1313 }
1314 n->m_len = 0;
1315
1316 /* Link it into the new chain */
1317 *p = n;
1318 p = &n->m_next;
1319
1320 /* Copy data from original mbuf(s) into new mbuf */
1321 while (n->m_len < nsize && m != NULL) {
1322 int chunk = min(nsize - n->m_len, m->m_len - moff);
1323
1324 bcopy(m->m_data + moff, n->m_data + n->m_len, chunk);
1325 moff += chunk;
1326 n->m_len += chunk;
1327 remain -= chunk;
1328 if (moff == m->m_len) {
1329 m = m->m_next;
1330 moff = 0;
1331 }
1332 }
1333
1334 /* Check correct total mbuf length */
1335 KASSERT((remain > 0 && m != NULL) || (remain == 0 && m == NULL),
5e2195bf 1336 ("%s: bogus m_pkthdr.len", __func__));
984263bc
MD
1337 }
1338 return (top);
1339
1340nospace:
1341 m_freem(top);
1342 MCFail++;
1343 return (0);
1344}
1345
1346/*
1347 * Concatenate mbuf chain n to m.
1348 * Both chains must be of the same type (e.g. MT_DATA).
1349 * Any m_pkthdr is not updated.
1350 */
1351void
8a3125c6 1352m_cat(struct mbuf *m, struct mbuf *n)
984263bc
MD
1353{
1354 while (m->m_next)
1355 m = m->m_next;
1356 while (n) {
1357 if (m->m_flags & M_EXT ||
1358 m->m_data + m->m_len + n->m_len >= &m->m_dat[MLEN]) {
1359 /* just join the two chains */
1360 m->m_next = n;
1361 return;
1362 }
1363 /* splat the data from one into the other */
1364 bcopy(mtod(n, caddr_t), mtod(m, caddr_t) + m->m_len,
1365 (u_int)n->m_len);
1366 m->m_len += n->m_len;
1367 n = m_free(n);
1368 }
1369}
1370
1371void
8a3125c6 1372m_adj(struct mbuf *mp, int req_len)
984263bc 1373{
1fd87d54
RG
1374 int len = req_len;
1375 struct mbuf *m;
1376 int count;
984263bc
MD
1377
1378 if ((m = mp) == NULL)
1379 return;
1380 if (len >= 0) {
1381 /*
1382 * Trim from head.
1383 */
1384 while (m != NULL && len > 0) {
1385 if (m->m_len <= len) {
1386 len -= m->m_len;
1387 m->m_len = 0;
1388 m = m->m_next;
1389 } else {
1390 m->m_len -= len;
1391 m->m_data += len;
1392 len = 0;
1393 }
1394 }
1395 m = mp;
1396 if (mp->m_flags & M_PKTHDR)
1397 m->m_pkthdr.len -= (req_len - len);
1398 } else {
1399 /*
1400 * Trim from tail. Scan the mbuf chain,
1401 * calculating its length and finding the last mbuf.
1402 * If the adjustment only affects this mbuf, then just
1403 * adjust and return. Otherwise, rescan and truncate
1404 * after the remaining size.
1405 */
1406 len = -len;
1407 count = 0;
1408 for (;;) {
1409 count += m->m_len;
1410 if (m->m_next == (struct mbuf *)0)
1411 break;
1412 m = m->m_next;
1413 }
1414 if (m->m_len >= len) {
1415 m->m_len -= len;
1416 if (mp->m_flags & M_PKTHDR)
1417 mp->m_pkthdr.len -= len;
1418 return;
1419 }
1420 count -= len;
1421 if (count < 0)
1422 count = 0;
1423 /*
1424 * Correct length for chain is "count".
1425 * Find the mbuf with last data, adjust its length,
1426 * and toss data from remaining mbufs on chain.
1427 */
1428 m = mp;
1429 if (m->m_flags & M_PKTHDR)
1430 m->m_pkthdr.len = count;
1431 for (; m; m = m->m_next) {
1432 if (m->m_len >= count) {
1433 m->m_len = count;
1434 break;
1435 }
1436 count -= m->m_len;
1437 }
1438 while (m->m_next)
1439 (m = m->m_next) ->m_len = 0;
1440 }
1441}
1442
1443/*
1444 * Rearange an mbuf chain so that len bytes are contiguous
9e4465af
MD
1445 * and in the data area of an mbuf (so that mtod will work for a structure
1446 * of size len). Returns the resulting mbuf chain on success, frees it and
1447 * returns null on failure. If there is room, it will add up to
1448 * max_protohdr-len extra bytes to the contiguous region in an attempt to
1449 * avoid being called next time.
984263bc
MD
1450 */
1451#define MPFail (mbstat.m_mpfail)
1452
1453struct mbuf *
8a3125c6 1454m_pullup(struct mbuf *n, int len)
984263bc 1455{
1fd87d54
RG
1456 struct mbuf *m;
1457 int count;
984263bc
MD
1458 int space;
1459
1460 /*
1461 * If first mbuf has no cluster, and has room for len bytes
1462 * without shifting current data, pullup into it,
1463 * otherwise allocate a new mbuf to prepend to the chain.
1464 */
1465 if ((n->m_flags & M_EXT) == 0 &&
1466 n->m_data + len < &n->m_dat[MLEN] && n->m_next) {
1467 if (n->m_len >= len)
1468 return (n);
1469 m = n;
1470 n = n->m_next;
1471 len -= m->m_len;
1472 } else {
1473 if (len > MHLEN)
1474 goto bad;
74f1caca 1475 MGET(m, MB_DONTWAIT, n->m_type);
984263bc
MD
1476 if (m == 0)
1477 goto bad;
1478 m->m_len = 0;
1479 if (n->m_flags & M_PKTHDR)
1480 M_MOVE_PKTHDR(m, n);
1481 }
1482 space = &m->m_dat[MLEN] - (m->m_data + m->m_len);
1483 do {
1484 count = min(min(max(len, max_protohdr), space), n->m_len);
1485 bcopy(mtod(n, caddr_t), mtod(m, caddr_t) + m->m_len,
1486 (unsigned)count);
1487 len -= count;
1488 m->m_len += count;
1489 n->m_len -= count;
1490 space -= count;
1491 if (n->m_len)
1492 n->m_data += count;
1493 else
1494 n = m_free(n);
1495 } while (len > 0 && n);
1496 if (len > 0) {
1497 (void) m_free(m);
1498 goto bad;
1499 }
1500 m->m_next = n;
1501 return (m);
1502bad:
1503 m_freem(n);
1504 MPFail++;
1505 return (0);
1506}
1507
1508/*
1509 * Partition an mbuf chain in two pieces, returning the tail --
1510 * all but the first len0 bytes. In case of failure, it returns NULL and
1511 * attempts to restore the chain to its original state.
1512 *
1513 * Note that the resulting mbufs might be read-only, because the new
1514 * mbuf can end up sharing an mbuf cluster with the original mbuf if
1515 * the "breaking point" happens to lie within a cluster mbuf. Use the
1516 * M_WRITABLE() macro to check for this case.
1517 */
1518struct mbuf *
8a3125c6 1519m_split(struct mbuf *m0, int len0, int wait)
984263bc 1520{
1fd87d54 1521 struct mbuf *m, *n;
984263bc
MD
1522 unsigned len = len0, remain;
1523
1524 for (m = m0; m && len > m->m_len; m = m->m_next)
1525 len -= m->m_len;
1526 if (m == 0)
1527 return (0);
1528 remain = m->m_len - len;
1529 if (m0->m_flags & M_PKTHDR) {
1530 MGETHDR(n, wait, m0->m_type);
1531 if (n == 0)
1532 return (0);
1533 n->m_pkthdr.rcvif = m0->m_pkthdr.rcvif;
1534 n->m_pkthdr.len = m0->m_pkthdr.len - len0;
1535 m0->m_pkthdr.len = len0;
1536 if (m->m_flags & M_EXT)
1537 goto extpacket;
1538 if (remain > MHLEN) {
1539 /* m can't be the lead packet */
1540 MH_ALIGN(n, 0);
1541 n->m_next = m_split(m, len, wait);
1542 if (n->m_next == 0) {
1543 (void) m_free(n);
1544 return (0);
1545 } else {
1546 n->m_len = 0;
1547 return (n);
1548 }
1549 } else
1550 MH_ALIGN(n, remain);
1551 } else if (remain == 0) {
1552 n = m->m_next;
1553 m->m_next = 0;
1554 return (n);
1555 } else {
1556 MGET(n, wait, m->m_type);
1557 if (n == 0)
1558 return (0);
1559 M_ALIGN(n, remain);
1560 }
1561extpacket:
1562 if (m->m_flags & M_EXT) {
984263bc 1563 n->m_data = m->m_data + len;
7eccf245
MD
1564 m_extref(m);
1565 n->m_ext = m->m_ext;
2915401a 1566 n->m_flags |= m->m_flags & (M_EXT | M_EXT_OLD | M_EXT_CLUSTER);
984263bc
MD
1567 } else {
1568 bcopy(mtod(m, caddr_t) + len, mtod(n, caddr_t), remain);
1569 }
1570 n->m_len = remain;
1571 m->m_len = len;
1572 n->m_next = m->m_next;
1573 m->m_next = 0;
1574 return (n);
1575}
1576/*
1577 * Routine to copy from device local memory into mbufs.
1578 */
1579struct mbuf *
8a3125c6
MD
1580m_devget(char *buf, int totlen, int off0, struct ifnet *ifp,
1581 void (*copy) (char *from, caddr_t to, u_int len))
984263bc 1582{
1fd87d54 1583 struct mbuf *m;
984263bc 1584 struct mbuf *top = 0, **mp = &top;
1fd87d54
RG
1585 int off = off0, len;
1586 char *cp;
984263bc
MD
1587 char *epkt;
1588
1589 cp = buf;
1590 epkt = cp + totlen;
1591 if (off) {
1592 cp += off + 2 * sizeof(u_short);
1593 totlen -= 2 * sizeof(u_short);
1594 }
74f1caca 1595 MGETHDR(m, MB_DONTWAIT, MT_DATA);
984263bc
MD
1596 if (m == 0)
1597 return (0);
1598 m->m_pkthdr.rcvif = ifp;
1599 m->m_pkthdr.len = totlen;
1600 m->m_len = MHLEN;
1601
1602 while (totlen > 0) {
1603 if (top) {
74f1caca 1604 MGET(m, MB_DONTWAIT, MT_DATA);
984263bc
MD
1605 if (m == 0) {
1606 m_freem(top);
1607 return (0);
1608 }
1609 m->m_len = MLEN;
1610 }
1611 len = min(totlen, epkt - cp);
1612 if (len >= MINCLSIZE) {
74f1caca 1613 MCLGET(m, MB_DONTWAIT);
984263bc
MD
1614 if (m->m_flags & M_EXT)
1615 m->m_len = len = min(len, MCLBYTES);
1616 else
1617 len = m->m_len;
1618 } else {
1619 /*
1620 * Place initial small packet/header at end of mbuf.
1621 */
1622 if (len < m->m_len) {
1623 if (top == 0 && len + max_linkhdr <= m->m_len)
1624 m->m_data += max_linkhdr;
1625 m->m_len = len;
1626 } else
1627 len = m->m_len;
1628 }
1629 if (copy)
1630 copy(cp, mtod(m, caddr_t), (unsigned)len);
1631 else
1632 bcopy(cp, mtod(m, caddr_t), (unsigned)len);
1633 cp += len;
1634 *mp = m;
1635 mp = &m->m_next;
1636 totlen -= len;
1637 if (cp == epkt)
1638 cp = buf;
1639 }
1640 return (top);
1641}
1642
1643/*
1644 * Copy data from a buffer back into the indicated mbuf chain,
1645 * starting "off" bytes from the beginning, extending the mbuf
1646 * chain if necessary.
1647 */
1648void
8a3125c6 1649m_copyback(struct mbuf *m0, int off, int len, caddr_t cp)
984263bc 1650{
1fd87d54
RG
1651 int mlen;
1652 struct mbuf *m = m0, *n;
984263bc
MD
1653 int totlen = 0;
1654
1655 if (m0 == 0)
1656 return;
1657 while (off > (mlen = m->m_len)) {
1658 off -= mlen;
1659 totlen += mlen;
1660 if (m->m_next == 0) {
74f1caca 1661 n = m_getclr(MB_DONTWAIT, m->m_type);
984263bc
MD
1662 if (n == 0)
1663 goto out;
1664 n->m_len = min(MLEN, len + off);
1665 m->m_next = n;
1666 }
1667 m = m->m_next;
1668 }
1669 while (len > 0) {
1670 mlen = min (m->m_len - off, len);
1671 bcopy(cp, off + mtod(m, caddr_t), (unsigned)mlen);
1672 cp += mlen;
1673 len -= mlen;
1674 mlen += off;
1675 off = 0;
1676 totlen += mlen;
1677 if (len == 0)
1678 break;
1679 if (m->m_next == 0) {
74f1caca 1680 n = m_get(MB_DONTWAIT, m->m_type);
984263bc
MD
1681 if (n == 0)
1682 break;
1683 n->m_len = min(MLEN, len);
1684 m->m_next = n;
1685 }
1686 m = m->m_next;
1687 }
1688out: if (((m = m0)->m_flags & M_PKTHDR) && (m->m_pkthdr.len < totlen))
1689 m->m_pkthdr.len = totlen;
1690}
1691
1692void
1693m_print(const struct mbuf *m)
1694{
1695 int len;
1696 const struct mbuf *m2;
1697
1698 len = m->m_pkthdr.len;
1699 m2 = m;
1700 while (len) {
1701 printf("%p %*D\n", m2, m2->m_len, (u_char *)m2->m_data, "-");
1702 len -= m2->m_len;
1703 m2 = m2->m_next;
1704 }
1705 return;
1706}
1707
1708/*
1709 * "Move" mbuf pkthdr from "from" to "to".
1710 * "from" must have M_PKTHDR set, and "to" must be empty.
1711 */
1712void
1713m_move_pkthdr(struct mbuf *to, struct mbuf *from)
1714{
1715 KASSERT((to->m_flags & M_EXT) == 0, ("m_move_pkthdr: to has cluster"));
1716
1717 to->m_flags = from->m_flags & M_COPYFLAGS;
1718 to->m_data = to->m_pktdat;
1719 to->m_pkthdr = from->m_pkthdr; /* especially tags */
1720 SLIST_INIT(&from->m_pkthdr.tags); /* purge tags from src */
1721 from->m_flags &= ~M_PKTHDR;
1722}
1723
1724/*
1725 * Duplicate "from"'s mbuf pkthdr in "to".
1726 * "from" must have M_PKTHDR set, and "to" must be empty.
1727 * In particular, this does a deep copy of the packet tags.
1728 */
1729int
f15db79e 1730m_dup_pkthdr(struct mbuf *to, const struct mbuf *from, int how)
984263bc
MD
1731{
1732 to->m_flags = (from->m_flags & M_COPYFLAGS) | (to->m_flags & M_EXT);
1733 if ((to->m_flags & M_EXT) == 0)
1734 to->m_data = to->m_pktdat;
1735 to->m_pkthdr = from->m_pkthdr;
1736 SLIST_INIT(&to->m_pkthdr.tags);
1737 return (m_tag_copy_chain(to, from, how));
1738}
1739
1740/*
1741 * Defragment a mbuf chain, returning the shortest possible
1742 * chain of mbufs and clusters. If allocation fails and
1743 * this cannot be completed, NULL will be returned, but
1744 * the passed in chain will be unchanged. Upon success,
1745 * the original chain will be freed, and the new chain
1746 * will be returned.
1747 *
1748 * If a non-packet header is passed in, the original
1749 * mbuf (chain?) will be returned unharmed.
1750 */
1751struct mbuf *
1752m_defrag(struct mbuf *m0, int how)
1753{
1754 struct mbuf *m_new = NULL, *m_final = NULL;
1755 int progress = 0, length;
1756
1757 if (!(m0->m_flags & M_PKTHDR))
1758 return (m0);
1759
1760#ifdef MBUF_STRESS_TEST
1761 if (m_defragrandomfailures) {
1762 int temp = arc4random() & 0xff;
1763 if (temp == 0xba)
1764 goto nospace;
1765 }
1766#endif
1767
1768 if (m0->m_pkthdr.len > MHLEN)
1769 m_final = m_getcl(how, MT_DATA, M_PKTHDR);
1770 else
1771 m_final = m_gethdr(how, MT_DATA);
1772
1773 if (m_final == NULL)
1774 goto nospace;
1775
1776 if (m_dup_pkthdr(m_final, m0, how) == NULL)
1777 goto nospace;
1778
1779 m_new = m_final;
1780
1781 while (progress < m0->m_pkthdr.len) {
1782 length = m0->m_pkthdr.len - progress;
1783 if (length > MCLBYTES)
1784 length = MCLBYTES;
1785
1786 if (m_new == NULL) {
1787 if (length > MLEN)
1788 m_new = m_getcl(how, MT_DATA, 0);
1789 else
1790 m_new = m_get(how, MT_DATA);
1791 if (m_new == NULL)
1792 goto nospace;
1793 }
1794
1795 m_copydata(m0, progress, length, mtod(m_new, caddr_t));
1796 progress += length;
1797 m_new->m_len = length;
1798 if (m_new != m_final)
1799 m_cat(m_final, m_new);
1800 m_new = NULL;
1801 }
1802 if (m0->m_next == NULL)
1803 m_defraguseless++;
1804 m_freem(m0);
1805 m0 = m_final;
1806 m_defragpackets++;
1807 m_defragbytes += m0->m_pkthdr.len;
1808 return (m0);
1809nospace:
1810 m_defragfailure++;
1811 if (m_new)
1812 m_free(m_new);
1813 if (m_final)
1814 m_freem(m_final);
1815 return (NULL);
1816}
0c33f36d
JH
1817
1818/*
1819 * Move data from uio into mbufs.
1820 * A length of zero means copy the whole uio.
1821 */
1822struct mbuf *
1823m_uiomove(struct uio *uio, int wait, int len0)
1824{
1825 struct mbuf *head; /* result mbuf chain */
1826 struct mbuf *m; /* current working mbuf */
1827 struct mbuf **mp;
1828 int resid, datalen, error;
1829
1830 resid = (len0 == 0) ? uio->uio_resid : min(len0, uio->uio_resid);
1831
1832 head = NULL;
1833 mp = &head;
1834 do {
1835 if (resid > MHLEN) {
1836 m = m_getcl(wait, MT_DATA, head == NULL ? M_PKTHDR : 0);
1837 if (m == NULL)
1838 goto failed;
1839 if (m->m_flags & M_PKTHDR)
1840 m->m_pkthdr.len = 0;
1841 } else {
1842 if (head == NULL) {
1843 MGETHDR(m, wait, MT_DATA);
1844 if (m == NULL)
1845 goto failed;
1846 m->m_pkthdr.len = 0;
1847 /* Leave room for protocol headers. */
1848 if (resid < MHLEN)
1849 MH_ALIGN(m, resid);
1850 } else {
1851 MGET(m, wait, MT_DATA);
1852 if (m == NULL)
1853 goto failed;
1854 }
1855 }
1856 datalen = min(MCLBYTES, resid);
1857 error = uiomove(mtod(m, caddr_t), datalen, uio);
1858 if (error) {
1859 m_free(m);
1860 goto failed;
1861 }
1862 m->m_len = datalen;
1863 *mp = m;
1864 mp = &m->m_next;
1865 head->m_pkthdr.len += datalen;
1866 resid -= datalen;
1867 } while (resid > 0);
1868
1869 return (head);
1870
1871failed:
1872 if (head)
1873 m_freem(head);
1874 return (NULL);
1875}