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15637ed4 RG |
1 | /* |
2 | * Copyright (c) 1982, 1986, 1988, 1991 Regents of the University of California. | |
3 | * All rights reserved. | |
4 | * | |
5 | * Redistribution and use in source and binary forms, with or without | |
6 | * modification, are permitted provided that the following conditions | |
7 | * are met: | |
8 | * 1. Redistributions of source code must retain the above copyright | |
9 | * notice, this list of conditions and the following disclaimer. | |
10 | * 2. Redistributions in binary form must reproduce the above copyright | |
11 | * notice, this list of conditions and the following disclaimer in the | |
12 | * documentation and/or other materials provided with the distribution. | |
13 | * 3. All advertising materials mentioning features or use of this software | |
14 | * must display the following acknowledgement: | |
15 | * This product includes software developed by the University of | |
16 | * California, Berkeley and its contributors. | |
17 | * 4. Neither the name of the University nor the names of its contributors | |
18 | * may be used to endorse or promote products derived from this software | |
19 | * without specific prior written permission. | |
20 | * | |
21 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND | |
22 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
23 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
24 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE | |
25 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
26 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
27 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
28 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
29 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
30 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
31 | * SUCH DAMAGE. | |
32 | * | |
33 | * @(#)uipc_mbuf.c 7.19 (Berkeley) 4/20/91 | |
34 | * | |
35 | * PATCHES MAGIC LEVEL PATCH THAT GOT US HERE | |
36 | * -------------------- ----- ---------------------- | |
37 | * CURRENT PATCH LEVEL: 1 00009 | |
38 | * -------------------- ----- ---------------------- | |
39 | * | |
40 | * 31 Aug 92 Wolfgang Solfrank Fixed mbuf allocation code | |
41 | */ | |
42 | ||
43 | #include "param.h" | |
44 | #include "proc.h" | |
45 | #include "malloc.h" | |
46 | #define MBTYPES | |
47 | #include "mbuf.h" | |
48 | #include "kernel.h" | |
49 | #include "syslog.h" | |
50 | #include "domain.h" | |
51 | #include "protosw.h" | |
52 | #include "vm/vm.h" | |
53 | ||
54 | extern vm_map_t mb_map; | |
55 | struct mbuf *mbutl; | |
56 | char *mclrefcnt; | |
57 | ||
58 | mbinit() | |
59 | { | |
60 | int s; | |
61 | ||
62 | #if CLBYTES < 4096 | |
63 | #define NCL_INIT (4096/CLBYTES) | |
64 | #else | |
65 | #define NCL_INIT 1 | |
66 | #endif | |
67 | s = splimp(); | |
68 | if (m_clalloc(NCL_INIT, M_DONTWAIT) == 0) | |
69 | goto bad; | |
70 | splx(s); | |
71 | return; | |
72 | bad: | |
73 | panic("mbinit"); | |
74 | } | |
75 | ||
76 | /* | |
77 | * Allocate some number of mbuf clusters | |
78 | * and place on cluster free list. | |
79 | * Must be called at splimp. | |
80 | */ | |
81 | /* ARGSUSED */ | |
82 | m_clalloc(ncl, how) /* 31 Aug 92*/ | |
83 | register int ncl; | |
84 | { | |
85 | int npg, mbx; | |
86 | register caddr_t p; | |
87 | register int i; | |
88 | static int logged; | |
89 | ||
90 | npg = ncl * CLSIZE; | |
91 | /* 31 Aug 92*/ | |
92 | p = (caddr_t)kmem_malloc(mb_map, ctob(npg), !(how&M_DONTWAIT)); | |
93 | if (p == NULL) { | |
94 | if (logged == 0) { | |
95 | logged++; | |
96 | log(LOG_ERR, "mb_map full\n"); | |
97 | } | |
98 | return (0); | |
99 | } | |
100 | ncl = ncl * CLBYTES / MCLBYTES; | |
101 | for (i = 0; i < ncl; i++) { | |
102 | ((union mcluster *)p)->mcl_next = mclfree; | |
103 | mclfree = (union mcluster *)p; | |
104 | p += MCLBYTES; | |
105 | mbstat.m_clfree++; | |
106 | } | |
107 | mbstat.m_clusters += ncl; | |
108 | return (1); | |
109 | } | |
110 | ||
111 | /* | |
112 | * When MGET failes, ask protocols to free space when short of memory, | |
113 | * then re-attempt to allocate an mbuf. | |
114 | */ | |
115 | struct mbuf * | |
116 | m_retry(i, t) | |
117 | int i, t; | |
118 | { | |
119 | register struct mbuf *m; | |
120 | ||
121 | m_reclaim(); | |
122 | #define m_retry(i, t) (struct mbuf *)0 | |
123 | MGET(m, i, t); | |
124 | #undef m_retry | |
125 | return (m); | |
126 | } | |
127 | ||
128 | /* | |
129 | * As above; retry an MGETHDR. | |
130 | */ | |
131 | struct mbuf * | |
132 | m_retryhdr(i, t) | |
133 | int i, t; | |
134 | { | |
135 | register struct mbuf *m; | |
136 | ||
137 | m_reclaim(); | |
138 | #define m_retryhdr(i, t) (struct mbuf *)0 | |
139 | MGETHDR(m, i, t); | |
140 | #undef m_retryhdr | |
141 | return (m); | |
142 | } | |
143 | ||
144 | m_reclaim() | |
145 | { | |
146 | register struct domain *dp; | |
147 | register struct protosw *pr; | |
148 | int s = splimp(); | |
149 | ||
150 | for (dp = domains; dp; dp = dp->dom_next) | |
151 | for (pr = dp->dom_protosw; pr < dp->dom_protoswNPROTOSW; pr++) | |
152 | if (pr->pr_drain) | |
153 | (*pr->pr_drain)(); | |
154 | splx(s); | |
155 | mbstat.m_drain++; | |
156 | } | |
157 | ||
158 | /* | |
159 | * Space allocation routines. | |
160 | * These are also available as macros | |
161 | * for critical paths. | |
162 | */ | |
163 | struct mbuf * | |
164 | m_get(how, type) /* 31 Aug 92*/ | |
165 | int how, type; | |
166 | { | |
167 | register struct mbuf *m; | |
168 | ||
169 | MGET(m, how, type); | |
170 | return (m); | |
171 | } | |
172 | ||
173 | struct mbuf * | |
174 | m_gethdr(how, type) /* 31 Aug 92*/ | |
175 | int how, type; | |
176 | { | |
177 | register struct mbuf *m; | |
178 | ||
179 | MGETHDR(m, how, type); | |
180 | return (m); | |
181 | } | |
182 | ||
183 | struct mbuf * | |
184 | m_getclr(how, type) /* 31 Aug 92*/ | |
185 | int how, type; | |
186 | { | |
187 | register struct mbuf *m; | |
188 | ||
189 | MGET(m, how, type); | |
190 | if (m == 0) | |
191 | return (0); | |
192 | bzero(mtod(m, caddr_t), MLEN); | |
193 | return (m); | |
194 | } | |
195 | ||
196 | struct mbuf * | |
197 | m_free(m) | |
198 | struct mbuf *m; | |
199 | { | |
200 | register struct mbuf *n; | |
201 | ||
202 | MFREE(m, n); | |
203 | return (n); | |
204 | } | |
205 | ||
206 | m_freem(m) | |
207 | register struct mbuf *m; | |
208 | { | |
209 | register struct mbuf *n; | |
210 | ||
211 | if (m == NULL) | |
212 | return; | |
213 | do { | |
214 | MFREE(m, n); | |
215 | } while (m = n); | |
216 | } | |
217 | ||
218 | /* | |
219 | * Mbuffer utility routines. | |
220 | */ | |
221 | ||
222 | /* | |
223 | * Lesser-used path for M_PREPEND: | |
224 | * allocate new mbuf to prepend to chain, | |
225 | * copy junk along. | |
226 | */ | |
227 | struct mbuf * | |
228 | m_prepend(m, len, how) | |
229 | register struct mbuf *m; | |
230 | int len, how; | |
231 | { | |
232 | struct mbuf *mn; | |
233 | ||
234 | MGET(mn, how, m->m_type); | |
235 | if (mn == (struct mbuf *)NULL) { | |
236 | m_freem(m); | |
237 | return ((struct mbuf *)NULL); | |
238 | } | |
239 | if (m->m_flags & M_PKTHDR) { | |
240 | M_COPY_PKTHDR(mn, m); | |
241 | m->m_flags &= ~M_PKTHDR; | |
242 | } | |
243 | mn->m_next = m; | |
244 | m = mn; | |
245 | if (len < MHLEN) | |
246 | MH_ALIGN(m, len); | |
247 | m->m_len = len; | |
248 | return (m); | |
249 | } | |
250 | ||
251 | /* | |
252 | * Make a copy of an mbuf chain starting "off0" bytes from the beginning, | |
253 | * continuing for "len" bytes. If len is M_COPYALL, copy to end of mbuf. | |
254 | * The wait parameter is a choice of M_WAIT/M_DONTWAIT from caller. | |
255 | */ | |
256 | int MCFail; | |
257 | ||
258 | struct mbuf * | |
259 | m_copym(m, off0, len, wait) | |
260 | register struct mbuf *m; | |
261 | int off0, wait; | |
262 | register int len; | |
263 | { | |
264 | register struct mbuf *n, **np; | |
265 | register int off = off0; | |
266 | struct mbuf *top; | |
267 | int copyhdr = 0; | |
268 | ||
269 | if (off < 0 || len < 0) | |
270 | panic("m_copym"); | |
271 | if (off == 0 && m->m_flags & M_PKTHDR) | |
272 | copyhdr = 1; | |
273 | while (off > 0) { | |
274 | if (m == 0) | |
275 | panic("m_copym"); | |
276 | if (off < m->m_len) | |
277 | break; | |
278 | off -= m->m_len; | |
279 | m = m->m_next; | |
280 | } | |
281 | np = ⊤ | |
282 | top = 0; | |
283 | while (len > 0) { | |
284 | if (m == 0) { | |
285 | if (len != M_COPYALL) | |
286 | panic("m_copym"); | |
287 | break; | |
288 | } | |
289 | MGET(n, wait, m->m_type); | |
290 | *np = n; | |
291 | if (n == 0) | |
292 | goto nospace; | |
293 | if (copyhdr) { | |
294 | M_COPY_PKTHDR(n, m); | |
295 | if (len == M_COPYALL) | |
296 | n->m_pkthdr.len -= off0; | |
297 | else | |
298 | n->m_pkthdr.len = len; | |
299 | copyhdr = 0; | |
300 | } | |
301 | n->m_len = MIN(len, m->m_len - off); | |
302 | if (m->m_flags & M_EXT) { | |
303 | n->m_data = m->m_data + off; | |
304 | mclrefcnt[mtocl(m->m_ext.ext_buf)]++; | |
305 | n->m_ext = m->m_ext; | |
306 | n->m_flags |= M_EXT; | |
307 | } else | |
308 | bcopy(mtod(m, caddr_t)+off, mtod(n, caddr_t), | |
309 | (unsigned)n->m_len); | |
310 | if (len != M_COPYALL) | |
311 | len -= n->m_len; | |
312 | off = 0; | |
313 | m = m->m_next; | |
314 | np = &n->m_next; | |
315 | } | |
316 | if (top == 0) | |
317 | MCFail++; | |
318 | return (top); | |
319 | nospace: | |
320 | m_freem(top); | |
321 | MCFail++; | |
322 | return (0); | |
323 | } | |
324 | ||
325 | /* | |
326 | * Copy data from an mbuf chain starting "off" bytes from the beginning, | |
327 | * continuing for "len" bytes, into the indicated buffer. | |
328 | */ | |
329 | m_copydata(m, off, len, cp) | |
330 | register struct mbuf *m; | |
331 | register int off; | |
332 | register int len; | |
333 | caddr_t cp; | |
334 | { | |
335 | register unsigned count; | |
336 | ||
337 | if (off < 0 || len < 0) | |
338 | panic("m_copydata"); | |
339 | while (off > 0) { | |
340 | if (m == 0) | |
341 | panic("m_copydata"); | |
342 | if (off < m->m_len) | |
343 | break; | |
344 | off -= m->m_len; | |
345 | m = m->m_next; | |
346 | } | |
347 | while (len > 0) { | |
348 | if (m == 0) | |
349 | panic("m_copydata"); | |
350 | count = MIN(m->m_len - off, len); | |
351 | bcopy(mtod(m, caddr_t) + off, cp, count); | |
352 | len -= count; | |
353 | cp += count; | |
354 | off = 0; | |
355 | m = m->m_next; | |
356 | } | |
357 | } | |
358 | ||
359 | /* | |
360 | * Concatenate mbuf chain n to m. | |
361 | * Both chains must be of the same type (e.g. MT_DATA). | |
362 | * Any m_pkthdr is not updated. | |
363 | */ | |
364 | m_cat(m, n) | |
365 | register struct mbuf *m, *n; | |
366 | { | |
367 | while (m->m_next) | |
368 | m = m->m_next; | |
369 | while (n) { | |
370 | if (m->m_flags & M_EXT || | |
371 | m->m_data + m->m_len + n->m_len >= &m->m_dat[MLEN]) { | |
372 | /* just join the two chains */ | |
373 | m->m_next = n; | |
374 | return; | |
375 | } | |
376 | /* splat the data from one into the other */ | |
377 | bcopy(mtod(n, caddr_t), mtod(m, caddr_t) + m->m_len, | |
378 | (u_int)n->m_len); | |
379 | m->m_len += n->m_len; | |
380 | n = m_free(n); | |
381 | } | |
382 | } | |
383 | ||
384 | m_adj(mp, req_len) | |
385 | struct mbuf *mp; | |
386 | { | |
387 | register int len = req_len; | |
388 | register struct mbuf *m; | |
389 | register count; | |
390 | ||
391 | if ((m = mp) == NULL) | |
392 | return; | |
393 | if (len >= 0) { | |
394 | /* | |
395 | * Trim from head. | |
396 | */ | |
397 | while (m != NULL && len > 0) { | |
398 | if (m->m_len <= len) { | |
399 | len -= m->m_len; | |
400 | m->m_len = 0; | |
401 | m = m->m_next; | |
402 | } else { | |
403 | m->m_len -= len; | |
404 | m->m_data += len; | |
405 | len = 0; | |
406 | } | |
407 | } | |
408 | m = mp; | |
409 | if (mp->m_flags & M_PKTHDR) | |
410 | m->m_pkthdr.len -= (req_len - len); | |
411 | } else { | |
412 | /* | |
413 | * Trim from tail. Scan the mbuf chain, | |
414 | * calculating its length and finding the last mbuf. | |
415 | * If the adjustment only affects this mbuf, then just | |
416 | * adjust and return. Otherwise, rescan and truncate | |
417 | * after the remaining size. | |
418 | */ | |
419 | len = -len; | |
420 | count = 0; | |
421 | for (;;) { | |
422 | count += m->m_len; | |
423 | if (m->m_next == (struct mbuf *)0) | |
424 | break; | |
425 | m = m->m_next; | |
426 | } | |
427 | if (m->m_len >= len) { | |
428 | m->m_len -= len; | |
429 | if ((mp = m)->m_flags & M_PKTHDR) | |
430 | m->m_pkthdr.len -= len; | |
431 | return; | |
432 | } | |
433 | count -= len; | |
434 | if (count < 0) | |
435 | count = 0; | |
436 | /* | |
437 | * Correct length for chain is "count". | |
438 | * Find the mbuf with last data, adjust its length, | |
439 | * and toss data from remaining mbufs on chain. | |
440 | */ | |
441 | m = mp; | |
442 | if (m->m_flags & M_PKTHDR) | |
443 | m->m_pkthdr.len = count; | |
444 | for (; m; m = m->m_next) { | |
445 | if (m->m_len >= count) { | |
446 | m->m_len = count; | |
447 | break; | |
448 | } | |
449 | count -= m->m_len; | |
450 | } | |
451 | while (m = m->m_next) | |
452 | m->m_len = 0; | |
453 | } | |
454 | } | |
455 | ||
456 | /* | |
457 | * Rearange an mbuf chain so that len bytes are contiguous | |
458 | * and in the data area of an mbuf (so that mtod and dtom | |
459 | * will work for a structure of size len). Returns the resulting | |
460 | * mbuf chain on success, frees it and returns null on failure. | |
461 | * If there is room, it will add up to max_protohdr-len extra bytes to the | |
462 | * contiguous region in an attempt to avoid being called next time. | |
463 | */ | |
464 | int MPFail; | |
465 | ||
466 | struct mbuf * | |
467 | m_pullup(n, len) | |
468 | register struct mbuf *n; | |
469 | int len; | |
470 | { | |
471 | register struct mbuf *m; | |
472 | register int count; | |
473 | int space; | |
474 | ||
475 | /* | |
476 | * If first mbuf has no cluster, and has room for len bytes | |
477 | * without shifting current data, pullup into it, | |
478 | * otherwise allocate a new mbuf to prepend to the chain. | |
479 | */ | |
480 | if ((n->m_flags & M_EXT) == 0 && | |
481 | n->m_data + len < &n->m_dat[MLEN] && n->m_next) { | |
482 | if (n->m_len >= len) | |
483 | return (n); | |
484 | m = n; | |
485 | n = n->m_next; | |
486 | len -= m->m_len; | |
487 | } else { | |
488 | if (len > MHLEN) | |
489 | goto bad; | |
490 | MGET(m, M_DONTWAIT, n->m_type); | |
491 | if (m == 0) | |
492 | goto bad; | |
493 | m->m_len = 0; | |
494 | if (n->m_flags & M_PKTHDR) { | |
495 | M_COPY_PKTHDR(m, n); | |
496 | n->m_flags &= ~M_PKTHDR; | |
497 | } | |
498 | } | |
499 | space = &m->m_dat[MLEN] - (m->m_data + m->m_len); | |
500 | do { | |
501 | count = min(min(max(len, max_protohdr), space), n->m_len); | |
502 | bcopy(mtod(n, caddr_t), mtod(m, caddr_t) + m->m_len, | |
503 | (unsigned)count); | |
504 | len -= count; | |
505 | m->m_len += count; | |
506 | n->m_len -= count; | |
507 | space -= count; | |
508 | if (n->m_len) | |
509 | n->m_data += count; | |
510 | else | |
511 | n = m_free(n); | |
512 | } while (len > 0 && n); | |
513 | if (len > 0) { | |
514 | (void) m_free(m); | |
515 | goto bad; | |
516 | } | |
517 | m->m_next = n; | |
518 | return (m); | |
519 | bad: | |
520 | m_freem(n); | |
521 | MPFail++; | |
522 | return (0); | |
523 | } |