1/*
2 * Copyright (c) 1982, 1986, 1988, 1991, 1993
3 * The Regents of the University of California. 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 8.2 (Berkeley) 1/4/94
| 1/*
2 * Copyright (c) 1982, 1986, 1988, 1991, 1993
3 * The Regents of the University of California. 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 8.2 (Berkeley) 1/4/94
|
34 * $FreeBSD: head/sys/kern/uipc_mbuf.c 103552 2002-09-18 19:42:06Z phk $
| 34 * $FreeBSD: head/sys/kern/uipc_mbuf.c 103569 2002-09-18 22:33:52Z bmilekic $
|
35 */
36
37#include "opt_mac.h"
38#include "opt_param.h"
39
40#include <sys/param.h>
41#include <sys/systm.h>
42#include <sys/kernel.h>
43#include <sys/lock.h>
44#include <sys/mac.h>
45#include <sys/malloc.h>
46#include <sys/mbuf.h>
47#include <sys/sysctl.h>
48#include <sys/domain.h>
49#include <sys/protosw.h>
50
51int max_linkhdr;
52int max_protohdr;
53int max_hdr;
54int max_datalen;
55
56/*
57 * sysctl(8) exported objects
58 */
59SYSCTL_DECL(_kern_ipc);
60SYSCTL_INT(_kern_ipc, KIPC_MAX_LINKHDR, max_linkhdr, CTLFLAG_RW,
61 &max_linkhdr, 0, "");
62SYSCTL_INT(_kern_ipc, KIPC_MAX_PROTOHDR, max_protohdr, CTLFLAG_RW,
63 &max_protohdr, 0, "");
64SYSCTL_INT(_kern_ipc, KIPC_MAX_HDR, max_hdr, CTLFLAG_RW, &max_hdr, 0, "");
65SYSCTL_INT(_kern_ipc, KIPC_MAX_DATALEN, max_datalen, CTLFLAG_RW,
66 &max_datalen, 0, "");
67
68/*
69 * Copy mbuf pkthdr from "from" to "to".
70 * "from" must have M_PKTHDR set, and "to" must be empty.
71 * aux pointer will be moved to "to".
72 */
73void
74m_copy_pkthdr(struct mbuf *to, struct mbuf *from)
75{
76
77#if 0
78 KASSERT(to->m_flags & M_PKTHDR,
79 ("m_copy_pkthdr() called on non-header"));
80#endif
81#ifdef MAC
82 if (to->m_flags & M_PKTHDR)
83 mac_destroy_mbuf(to);
84#endif
85 to->m_data = to->m_pktdat;
86 to->m_flags = from->m_flags & M_COPYFLAGS;
87 to->m_pkthdr = from->m_pkthdr;
88#ifdef MAC
89 mac_init_mbuf(to, 1); /* XXXMAC no way to fail */
90 mac_create_mbuf_from_mbuf(from, to);
91#endif
92 from->m_pkthdr.aux = NULL;
93}
94
95/*
96 * Lesser-used path for M_PREPEND:
97 * allocate new mbuf to prepend to chain,
98 * copy junk along.
99 */
100struct mbuf *
101m_prepend(struct mbuf *m, int len, int how)
102{
103 struct mbuf *mn;
104
105 MGET(mn, how, m->m_type);
106 if (mn == NULL) {
107 m_freem(m);
108 return (NULL);
109 }
110 if (m->m_flags & M_PKTHDR) {
111 M_COPY_PKTHDR(mn, m);
112#ifdef MAC
113 mac_destroy_mbuf(m);
114#endif
115 m->m_flags &= ~M_PKTHDR;
116 }
117 mn->m_next = m;
118 m = mn;
119 if (len < MHLEN)
120 MH_ALIGN(m, len);
121 m->m_len = len;
122 return (m);
123}
124
125/*
126 * Make a copy of an mbuf chain starting "off0" bytes from the beginning,
127 * continuing for "len" bytes. If len is M_COPYALL, copy to end of mbuf.
128 * The wait parameter is a choice of M_TRYWAIT/M_DONTWAIT from caller.
129 * Note that the copy is read-only, because clusters are not copied,
130 * only their reference counts are incremented.
131 */
132struct mbuf *
133m_copym(struct mbuf *m, int off0, int len, int wait)
134{
135 struct mbuf *n, **np;
136 int off = off0;
137 struct mbuf *top;
138 int copyhdr = 0;
139
140 KASSERT(off >= 0, ("m_copym, negative off %d", off));
141 KASSERT(len >= 0, ("m_copym, negative len %d", len));
142 if (off == 0 && m->m_flags & M_PKTHDR)
143 copyhdr = 1;
144 while (off > 0) {
145 KASSERT(m != NULL, ("m_copym, offset > size of mbuf chain"));
146 if (off < m->m_len)
147 break;
148 off -= m->m_len;
149 m = m->m_next;
150 }
151 np = ⊤
152 top = 0;
153 while (len > 0) {
154 if (m == NULL) {
155 KASSERT(len == M_COPYALL,
156 ("m_copym, length > size of mbuf chain"));
157 break;
158 }
159 MGET(n, wait, m->m_type);
160 *np = n;
161 if (n == NULL)
162 goto nospace;
163 if (copyhdr) {
164 M_COPY_PKTHDR(n, m);
165 if (len == M_COPYALL)
166 n->m_pkthdr.len -= off0;
167 else
168 n->m_pkthdr.len = len;
169 copyhdr = 0;
170 }
171 n->m_len = min(len, m->m_len - off);
172 if (m->m_flags & M_EXT) {
173 n->m_data = m->m_data + off;
174 n->m_ext = m->m_ext;
175 n->m_flags |= M_EXT;
176 MEXT_ADD_REF(m);
177 } else
178 bcopy(mtod(m, caddr_t)+off, mtod(n, caddr_t),
| 35 */
36
37#include "opt_mac.h"
38#include "opt_param.h"
39
40#include <sys/param.h>
41#include <sys/systm.h>
42#include <sys/kernel.h>
43#include <sys/lock.h>
44#include <sys/mac.h>
45#include <sys/malloc.h>
46#include <sys/mbuf.h>
47#include <sys/sysctl.h>
48#include <sys/domain.h>
49#include <sys/protosw.h>
50
51int max_linkhdr;
52int max_protohdr;
53int max_hdr;
54int max_datalen;
55
56/*
57 * sysctl(8) exported objects
58 */
59SYSCTL_DECL(_kern_ipc);
60SYSCTL_INT(_kern_ipc, KIPC_MAX_LINKHDR, max_linkhdr, CTLFLAG_RW,
61 &max_linkhdr, 0, "");
62SYSCTL_INT(_kern_ipc, KIPC_MAX_PROTOHDR, max_protohdr, CTLFLAG_RW,
63 &max_protohdr, 0, "");
64SYSCTL_INT(_kern_ipc, KIPC_MAX_HDR, max_hdr, CTLFLAG_RW, &max_hdr, 0, "");
65SYSCTL_INT(_kern_ipc, KIPC_MAX_DATALEN, max_datalen, CTLFLAG_RW,
66 &max_datalen, 0, "");
67
68/*
69 * Copy mbuf pkthdr from "from" to "to".
70 * "from" must have M_PKTHDR set, and "to" must be empty.
71 * aux pointer will be moved to "to".
72 */
73void
74m_copy_pkthdr(struct mbuf *to, struct mbuf *from)
75{
76
77#if 0
78 KASSERT(to->m_flags & M_PKTHDR,
79 ("m_copy_pkthdr() called on non-header"));
80#endif
81#ifdef MAC
82 if (to->m_flags & M_PKTHDR)
83 mac_destroy_mbuf(to);
84#endif
85 to->m_data = to->m_pktdat;
86 to->m_flags = from->m_flags & M_COPYFLAGS;
87 to->m_pkthdr = from->m_pkthdr;
88#ifdef MAC
89 mac_init_mbuf(to, 1); /* XXXMAC no way to fail */
90 mac_create_mbuf_from_mbuf(from, to);
91#endif
92 from->m_pkthdr.aux = NULL;
93}
94
95/*
96 * Lesser-used path for M_PREPEND:
97 * allocate new mbuf to prepend to chain,
98 * copy junk along.
99 */
100struct mbuf *
101m_prepend(struct mbuf *m, int len, int how)
102{
103 struct mbuf *mn;
104
105 MGET(mn, how, m->m_type);
106 if (mn == NULL) {
107 m_freem(m);
108 return (NULL);
109 }
110 if (m->m_flags & M_PKTHDR) {
111 M_COPY_PKTHDR(mn, m);
112#ifdef MAC
113 mac_destroy_mbuf(m);
114#endif
115 m->m_flags &= ~M_PKTHDR;
116 }
117 mn->m_next = m;
118 m = mn;
119 if (len < MHLEN)
120 MH_ALIGN(m, len);
121 m->m_len = len;
122 return (m);
123}
124
125/*
126 * Make a copy of an mbuf chain starting "off0" bytes from the beginning,
127 * continuing for "len" bytes. If len is M_COPYALL, copy to end of mbuf.
128 * The wait parameter is a choice of M_TRYWAIT/M_DONTWAIT from caller.
129 * Note that the copy is read-only, because clusters are not copied,
130 * only their reference counts are incremented.
131 */
132struct mbuf *
133m_copym(struct mbuf *m, int off0, int len, int wait)
134{
135 struct mbuf *n, **np;
136 int off = off0;
137 struct mbuf *top;
138 int copyhdr = 0;
139
140 KASSERT(off >= 0, ("m_copym, negative off %d", off));
141 KASSERT(len >= 0, ("m_copym, negative len %d", len));
142 if (off == 0 && m->m_flags & M_PKTHDR)
143 copyhdr = 1;
144 while (off > 0) {
145 KASSERT(m != NULL, ("m_copym, offset > size of mbuf chain"));
146 if (off < m->m_len)
147 break;
148 off -= m->m_len;
149 m = m->m_next;
150 }
151 np = ⊤
152 top = 0;
153 while (len > 0) {
154 if (m == NULL) {
155 KASSERT(len == M_COPYALL,
156 ("m_copym, length > size of mbuf chain"));
157 break;
158 }
159 MGET(n, wait, m->m_type);
160 *np = n;
161 if (n == NULL)
162 goto nospace;
163 if (copyhdr) {
164 M_COPY_PKTHDR(n, m);
165 if (len == M_COPYALL)
166 n->m_pkthdr.len -= off0;
167 else
168 n->m_pkthdr.len = len;
169 copyhdr = 0;
170 }
171 n->m_len = min(len, m->m_len - off);
172 if (m->m_flags & M_EXT) {
173 n->m_data = m->m_data + off;
174 n->m_ext = m->m_ext;
175 n->m_flags |= M_EXT;
176 MEXT_ADD_REF(m);
177 } else
178 bcopy(mtod(m, caddr_t)+off, mtod(n, caddr_t),
|
179 (unsigned)n->m_len);
| 179 (u_int)n->m_len);
|
180 if (len != M_COPYALL)
181 len -= n->m_len;
182 off = 0;
183 m = m->m_next;
184 np = &n->m_next;
185 }
186 if (top == NULL)
187 mbstat.m_mcfail++; /* XXX: No consistency. */
188
189 return (top);
190nospace:
191 m_freem(top);
192 mbstat.m_mcfail++; /* XXX: No consistency. */
193 return (NULL);
194}
195
196/*
197 * Copy an entire packet, including header (which must be present).
198 * An optimization of the common case `m_copym(m, 0, M_COPYALL, how)'.
199 * Note that the copy is read-only, because clusters are not copied,
200 * only their reference counts are incremented.
201 * Preserve alignment of the first mbuf so if the creator has left
202 * some room at the beginning (e.g. for inserting protocol headers)
203 * the copies still have the room available.
204 */
205struct mbuf *
206m_copypacket(struct mbuf *m, int how)
207{
208 struct mbuf *top, *n, *o;
209
210 MGET(n, how, m->m_type);
211 top = n;
212 if (n == NULL)
213 goto nospace;
214
215 M_COPY_PKTHDR(n, m);
216 n->m_len = m->m_len;
217 if (m->m_flags & M_EXT) {
218 n->m_data = m->m_data;
219 n->m_ext = m->m_ext;
220 n->m_flags |= M_EXT;
221 MEXT_ADD_REF(m);
222 } else {
223 n->m_data = n->m_pktdat + (m->m_data - m->m_pktdat );
224 bcopy(mtod(m, char *), mtod(n, char *), n->m_len);
225 }
226
227 m = m->m_next;
228 while (m) {
229 MGET(o, how, m->m_type);
230 if (o == NULL)
231 goto nospace;
232
233 n->m_next = o;
234 n = n->m_next;
235
236 n->m_len = m->m_len;
237 if (m->m_flags & M_EXT) {
238 n->m_data = m->m_data;
239 n->m_ext = m->m_ext;
240 n->m_flags |= M_EXT;
241 MEXT_ADD_REF(m);
242 } else {
243 bcopy(mtod(m, char *), mtod(n, char *), n->m_len);
244 }
245
246 m = m->m_next;
247 }
248 return top;
249nospace:
250 m_freem(top);
251 mbstat.m_mcfail++; /* XXX: No consistency. */
252 return (NULL);
253}
254
255/*
256 * Copy data from an mbuf chain starting "off" bytes from the beginning,
257 * continuing for "len" bytes, into the indicated buffer.
258 */
259void
260m_copydata(const struct mbuf *m, int off, int len, caddr_t cp)
261{
| 180 if (len != M_COPYALL)
181 len -= n->m_len;
182 off = 0;
183 m = m->m_next;
184 np = &n->m_next;
185 }
186 if (top == NULL)
187 mbstat.m_mcfail++; /* XXX: No consistency. */
188
189 return (top);
190nospace:
191 m_freem(top);
192 mbstat.m_mcfail++; /* XXX: No consistency. */
193 return (NULL);
194}
195
196/*
197 * Copy an entire packet, including header (which must be present).
198 * An optimization of the common case `m_copym(m, 0, M_COPYALL, how)'.
199 * Note that the copy is read-only, because clusters are not copied,
200 * only their reference counts are incremented.
201 * Preserve alignment of the first mbuf so if the creator has left
202 * some room at the beginning (e.g. for inserting protocol headers)
203 * the copies still have the room available.
204 */
205struct mbuf *
206m_copypacket(struct mbuf *m, int how)
207{
208 struct mbuf *top, *n, *o;
209
210 MGET(n, how, m->m_type);
211 top = n;
212 if (n == NULL)
213 goto nospace;
214
215 M_COPY_PKTHDR(n, m);
216 n->m_len = m->m_len;
217 if (m->m_flags & M_EXT) {
218 n->m_data = m->m_data;
219 n->m_ext = m->m_ext;
220 n->m_flags |= M_EXT;
221 MEXT_ADD_REF(m);
222 } else {
223 n->m_data = n->m_pktdat + (m->m_data - m->m_pktdat );
224 bcopy(mtod(m, char *), mtod(n, char *), n->m_len);
225 }
226
227 m = m->m_next;
228 while (m) {
229 MGET(o, how, m->m_type);
230 if (o == NULL)
231 goto nospace;
232
233 n->m_next = o;
234 n = n->m_next;
235
236 n->m_len = m->m_len;
237 if (m->m_flags & M_EXT) {
238 n->m_data = m->m_data;
239 n->m_ext = m->m_ext;
240 n->m_flags |= M_EXT;
241 MEXT_ADD_REF(m);
242 } else {
243 bcopy(mtod(m, char *), mtod(n, char *), n->m_len);
244 }
245
246 m = m->m_next;
247 }
248 return top;
249nospace:
250 m_freem(top);
251 mbstat.m_mcfail++; /* XXX: No consistency. */
252 return (NULL);
253}
254
255/*
256 * Copy data from an mbuf chain starting "off" bytes from the beginning,
257 * continuing for "len" bytes, into the indicated buffer.
258 */
259void
260m_copydata(const struct mbuf *m, int off, int len, caddr_t cp)
261{
|
262 unsigned count;
| 262 u_int count;
|
263
264 KASSERT(off >= 0, ("m_copydata, negative off %d", off));
265 KASSERT(len >= 0, ("m_copydata, negative len %d", len));
266 while (off > 0) {
267 KASSERT(m != NULL, ("m_copydata, offset > size of mbuf chain"));
268 if (off < m->m_len)
269 break;
270 off -= m->m_len;
271 m = m->m_next;
272 }
273 while (len > 0) {
274 KASSERT(m != NULL, ("m_copydata, length > size of mbuf chain"));
275 count = min(m->m_len - off, len);
276 bcopy(mtod(m, caddr_t) + off, cp, count);
277 len -= count;
278 cp += count;
279 off = 0;
280 m = m->m_next;
281 }
282}
283
284/*
285 * Copy a packet header mbuf chain into a completely new chain, including
286 * copying any mbuf clusters. Use this instead of m_copypacket() when
287 * you need a writable copy of an mbuf chain.
288 */
289struct mbuf *
290m_dup(struct mbuf *m, int how)
291{
292 struct mbuf **p, *top = NULL;
293 int remain, moff, nsize;
294
295 /* Sanity check */
296 if (m == NULL)
297 return (NULL);
298 KASSERT((m->m_flags & M_PKTHDR) != 0, ("%s: !PKTHDR", __func__));
299
300 /* While there's more data, get a new mbuf, tack it on, and fill it */
301 remain = m->m_pkthdr.len;
302 moff = 0;
303 p = ⊤
304 while (remain > 0 || top == NULL) { /* allow m->m_pkthdr.len == 0 */
305 struct mbuf *n;
306
307 /* Get the next new mbuf */
308 MGET(n, how, m->m_type);
309 if (n == NULL)
310 goto nospace;
311 if (top == NULL) { /* first one, must be PKTHDR */
312 M_COPY_PKTHDR(n, m);
313 nsize = MHLEN;
314 } else /* not the first one */
315 nsize = MLEN;
316 if (remain >= MINCLSIZE) {
317 MCLGET(n, how);
318 if ((n->m_flags & M_EXT) == 0) {
319 (void)m_free(n);
320 goto nospace;
321 }
322 nsize = MCLBYTES;
323 }
324 n->m_len = 0;
325
326 /* Link it into the new chain */
327 *p = n;
328 p = &n->m_next;
329
330 /* Copy data from original mbuf(s) into new mbuf */
331 while (n->m_len < nsize && m != NULL) {
332 int chunk = min(nsize - n->m_len, m->m_len - moff);
333
334 bcopy(m->m_data + moff, n->m_data + n->m_len, chunk);
335 moff += chunk;
336 n->m_len += chunk;
337 remain -= chunk;
338 if (moff == m->m_len) {
339 m = m->m_next;
340 moff = 0;
341 }
342 }
343
344 /* Check correct total mbuf length */
345 KASSERT((remain > 0 && m != NULL) || (remain == 0 && m == NULL),
346 ("%s: bogus m_pkthdr.len", __func__));
347 }
348 return (top);
349
350nospace:
351 m_freem(top);
352 mbstat.m_mcfail++; /* XXX: No consistency. */
353 return (NULL);
354}
355
356/*
357 * Concatenate mbuf chain n to m.
358 * Both chains must be of the same type (e.g. MT_DATA).
359 * Any m_pkthdr is not updated.
360 */
361void
362m_cat(struct mbuf *m, struct mbuf *n)
363{
364 while (m->m_next)
365 m = m->m_next;
366 while (n) {
367 if (m->m_flags & M_EXT ||
368 m->m_data + m->m_len + n->m_len >= &m->m_dat[MLEN]) {
369 /* just join the two chains */
370 m->m_next = n;
371 return;
372 }
373 /* splat the data from one into the other */
374 bcopy(mtod(n, caddr_t), mtod(m, caddr_t) + m->m_len,
375 (u_int)n->m_len);
376 m->m_len += n->m_len;
377 n = m_free(n);
378 }
379}
380
381void
382m_adj(struct mbuf *mp, int req_len)
383{
384 int len = req_len;
385 struct mbuf *m;
386 int count;
387
388 if ((m = mp) == NULL)
389 return;
390 if (len >= 0) {
391 /*
392 * Trim from head.
393 */
394 while (m != NULL && len > 0) {
395 if (m->m_len <= len) {
396 len -= m->m_len;
397 m->m_len = 0;
398 m = m->m_next;
399 } else {
400 m->m_len -= len;
401 m->m_data += len;
402 len = 0;
403 }
404 }
405 m = mp;
406 if (mp->m_flags & M_PKTHDR)
407 m->m_pkthdr.len -= (req_len - len);
408 } else {
409 /*
410 * Trim from tail. Scan the mbuf chain,
411 * calculating its length and finding the last mbuf.
412 * If the adjustment only affects this mbuf, then just
413 * adjust and return. Otherwise, rescan and truncate
414 * after the remaining size.
415 */
416 len = -len;
417 count = 0;
418 for (;;) {
419 count += m->m_len;
420 if (m->m_next == (struct mbuf *)0)
421 break;
422 m = m->m_next;
423 }
424 if (m->m_len >= len) {
425 m->m_len -= len;
426 if (mp->m_flags & M_PKTHDR)
427 mp->m_pkthdr.len -= len;
428 return;
429 }
430 count -= len;
431 if (count < 0)
432 count = 0;
433 /*
434 * Correct length for chain is "count".
435 * Find the mbuf with last data, adjust its length,
436 * and toss data from remaining mbufs on chain.
437 */
438 m = mp;
439 if (m->m_flags & M_PKTHDR)
440 m->m_pkthdr.len = count;
441 for (; m; m = m->m_next) {
442 if (m->m_len >= count) {
443 m->m_len = count;
444 break;
445 }
446 count -= m->m_len;
447 }
448 while (m->m_next)
449 (m = m->m_next) ->m_len = 0;
450 }
451}
452
453/*
454 * Rearange an mbuf chain so that len bytes are contiguous
455 * and in the data area of an mbuf (so that mtod and dtom
456 * will work for a structure of size len). Returns the resulting
457 * mbuf chain on success, frees it and returns null on failure.
458 * If there is room, it will add up to max_protohdr-len extra bytes to the
459 * contiguous region in an attempt to avoid being called next time.
460 */
461struct mbuf *
462m_pullup(struct mbuf *n, int len)
463{
464 struct mbuf *m;
465 int count;
466 int space;
467
468 /*
469 * If first mbuf has no cluster, and has room for len bytes
470 * without shifting current data, pullup into it,
471 * otherwise allocate a new mbuf to prepend to the chain.
472 */
473 if ((n->m_flags & M_EXT) == 0 &&
474 n->m_data + len < &n->m_dat[MLEN] && n->m_next) {
475 if (n->m_len >= len)
476 return (n);
477 m = n;
478 n = n->m_next;
479 len -= m->m_len;
480 } else {
481 if (len > MHLEN)
482 goto bad;
483 MGET(m, M_DONTWAIT, n->m_type);
484 if (m == NULL)
485 goto bad;
486 m->m_len = 0;
487 if (n->m_flags & M_PKTHDR) {
488 M_COPY_PKTHDR(m, n);
489 n->m_flags &= ~M_PKTHDR;
490 }
491 }
492 space = &m->m_dat[MLEN] - (m->m_data + m->m_len);
493 do {
494 count = min(min(max(len, max_protohdr), space), n->m_len);
495 bcopy(mtod(n, caddr_t), mtod(m, caddr_t) + m->m_len,
| 263
264 KASSERT(off >= 0, ("m_copydata, negative off %d", off));
265 KASSERT(len >= 0, ("m_copydata, negative len %d", len));
266 while (off > 0) {
267 KASSERT(m != NULL, ("m_copydata, offset > size of mbuf chain"));
268 if (off < m->m_len)
269 break;
270 off -= m->m_len;
271 m = m->m_next;
272 }
273 while (len > 0) {
274 KASSERT(m != NULL, ("m_copydata, length > size of mbuf chain"));
275 count = min(m->m_len - off, len);
276 bcopy(mtod(m, caddr_t) + off, cp, count);
277 len -= count;
278 cp += count;
279 off = 0;
280 m = m->m_next;
281 }
282}
283
284/*
285 * Copy a packet header mbuf chain into a completely new chain, including
286 * copying any mbuf clusters. Use this instead of m_copypacket() when
287 * you need a writable copy of an mbuf chain.
288 */
289struct mbuf *
290m_dup(struct mbuf *m, int how)
291{
292 struct mbuf **p, *top = NULL;
293 int remain, moff, nsize;
294
295 /* Sanity check */
296 if (m == NULL)
297 return (NULL);
298 KASSERT((m->m_flags & M_PKTHDR) != 0, ("%s: !PKTHDR", __func__));
299
300 /* While there's more data, get a new mbuf, tack it on, and fill it */
301 remain = m->m_pkthdr.len;
302 moff = 0;
303 p = ⊤
304 while (remain > 0 || top == NULL) { /* allow m->m_pkthdr.len == 0 */
305 struct mbuf *n;
306
307 /* Get the next new mbuf */
308 MGET(n, how, m->m_type);
309 if (n == NULL)
310 goto nospace;
311 if (top == NULL) { /* first one, must be PKTHDR */
312 M_COPY_PKTHDR(n, m);
313 nsize = MHLEN;
314 } else /* not the first one */
315 nsize = MLEN;
316 if (remain >= MINCLSIZE) {
317 MCLGET(n, how);
318 if ((n->m_flags & M_EXT) == 0) {
319 (void)m_free(n);
320 goto nospace;
321 }
322 nsize = MCLBYTES;
323 }
324 n->m_len = 0;
325
326 /* Link it into the new chain */
327 *p = n;
328 p = &n->m_next;
329
330 /* Copy data from original mbuf(s) into new mbuf */
331 while (n->m_len < nsize && m != NULL) {
332 int chunk = min(nsize - n->m_len, m->m_len - moff);
333
334 bcopy(m->m_data + moff, n->m_data + n->m_len, chunk);
335 moff += chunk;
336 n->m_len += chunk;
337 remain -= chunk;
338 if (moff == m->m_len) {
339 m = m->m_next;
340 moff = 0;
341 }
342 }
343
344 /* Check correct total mbuf length */
345 KASSERT((remain > 0 && m != NULL) || (remain == 0 && m == NULL),
346 ("%s: bogus m_pkthdr.len", __func__));
347 }
348 return (top);
349
350nospace:
351 m_freem(top);
352 mbstat.m_mcfail++; /* XXX: No consistency. */
353 return (NULL);
354}
355
356/*
357 * Concatenate mbuf chain n to m.
358 * Both chains must be of the same type (e.g. MT_DATA).
359 * Any m_pkthdr is not updated.
360 */
361void
362m_cat(struct mbuf *m, struct mbuf *n)
363{
364 while (m->m_next)
365 m = m->m_next;
366 while (n) {
367 if (m->m_flags & M_EXT ||
368 m->m_data + m->m_len + n->m_len >= &m->m_dat[MLEN]) {
369 /* just join the two chains */
370 m->m_next = n;
371 return;
372 }
373 /* splat the data from one into the other */
374 bcopy(mtod(n, caddr_t), mtod(m, caddr_t) + m->m_len,
375 (u_int)n->m_len);
376 m->m_len += n->m_len;
377 n = m_free(n);
378 }
379}
380
381void
382m_adj(struct mbuf *mp, int req_len)
383{
384 int len = req_len;
385 struct mbuf *m;
386 int count;
387
388 if ((m = mp) == NULL)
389 return;
390 if (len >= 0) {
391 /*
392 * Trim from head.
393 */
394 while (m != NULL && len > 0) {
395 if (m->m_len <= len) {
396 len -= m->m_len;
397 m->m_len = 0;
398 m = m->m_next;
399 } else {
400 m->m_len -= len;
401 m->m_data += len;
402 len = 0;
403 }
404 }
405 m = mp;
406 if (mp->m_flags & M_PKTHDR)
407 m->m_pkthdr.len -= (req_len - len);
408 } else {
409 /*
410 * Trim from tail. Scan the mbuf chain,
411 * calculating its length and finding the last mbuf.
412 * If the adjustment only affects this mbuf, then just
413 * adjust and return. Otherwise, rescan and truncate
414 * after the remaining size.
415 */
416 len = -len;
417 count = 0;
418 for (;;) {
419 count += m->m_len;
420 if (m->m_next == (struct mbuf *)0)
421 break;
422 m = m->m_next;
423 }
424 if (m->m_len >= len) {
425 m->m_len -= len;
426 if (mp->m_flags & M_PKTHDR)
427 mp->m_pkthdr.len -= len;
428 return;
429 }
430 count -= len;
431 if (count < 0)
432 count = 0;
433 /*
434 * Correct length for chain is "count".
435 * Find the mbuf with last data, adjust its length,
436 * and toss data from remaining mbufs on chain.
437 */
438 m = mp;
439 if (m->m_flags & M_PKTHDR)
440 m->m_pkthdr.len = count;
441 for (; m; m = m->m_next) {
442 if (m->m_len >= count) {
443 m->m_len = count;
444 break;
445 }
446 count -= m->m_len;
447 }
448 while (m->m_next)
449 (m = m->m_next) ->m_len = 0;
450 }
451}
452
453/*
454 * Rearange an mbuf chain so that len bytes are contiguous
455 * and in the data area of an mbuf (so that mtod and dtom
456 * will work for a structure of size len). Returns the resulting
457 * mbuf chain on success, frees it and returns null on failure.
458 * If there is room, it will add up to max_protohdr-len extra bytes to the
459 * contiguous region in an attempt to avoid being called next time.
460 */
461struct mbuf *
462m_pullup(struct mbuf *n, int len)
463{
464 struct mbuf *m;
465 int count;
466 int space;
467
468 /*
469 * If first mbuf has no cluster, and has room for len bytes
470 * without shifting current data, pullup into it,
471 * otherwise allocate a new mbuf to prepend to the chain.
472 */
473 if ((n->m_flags & M_EXT) == 0 &&
474 n->m_data + len < &n->m_dat[MLEN] && n->m_next) {
475 if (n->m_len >= len)
476 return (n);
477 m = n;
478 n = n->m_next;
479 len -= m->m_len;
480 } else {
481 if (len > MHLEN)
482 goto bad;
483 MGET(m, M_DONTWAIT, n->m_type);
484 if (m == NULL)
485 goto bad;
486 m->m_len = 0;
487 if (n->m_flags & M_PKTHDR) {
488 M_COPY_PKTHDR(m, n);
489 n->m_flags &= ~M_PKTHDR;
490 }
491 }
492 space = &m->m_dat[MLEN] - (m->m_data + m->m_len);
493 do {
494 count = min(min(max(len, max_protohdr), space), n->m_len);
495 bcopy(mtod(n, caddr_t), mtod(m, caddr_t) + m->m_len,
|
496 (unsigned)count);
| 496 (u_int)count);
|
497 len -= count;
498 m->m_len += count;
499 n->m_len -= count;
500 space -= count;
501 if (n->m_len)
502 n->m_data += count;
503 else
504 n = m_free(n);
505 } while (len > 0 && n);
506 if (len > 0) {
507 (void) m_free(m);
508 goto bad;
509 }
510 m->m_next = n;
511 return (m);
512bad:
513 m_freem(n);
514 mbstat.m_mpfail++; /* XXX: No consistency. */
515 return (NULL);
516}
517
518/*
519 * Partition an mbuf chain in two pieces, returning the tail --
520 * all but the first len0 bytes. In case of failure, it returns NULL and
521 * attempts to restore the chain to its original state.
522 *
523 * Note that the resulting mbufs might be read-only, because the new
524 * mbuf can end up sharing an mbuf cluster with the original mbuf if
525 * the "breaking point" happens to lie within a cluster mbuf. Use the
526 * M_WRITABLE() macro to check for this case.
527 */
528struct mbuf *
529m_split(struct mbuf *m0, int len0, int wait)
530{
531 struct mbuf *m, *n;
| 497 len -= count;
498 m->m_len += count;
499 n->m_len -= count;
500 space -= count;
501 if (n->m_len)
502 n->m_data += count;
503 else
504 n = m_free(n);
505 } while (len > 0 && n);
506 if (len > 0) {
507 (void) m_free(m);
508 goto bad;
509 }
510 m->m_next = n;
511 return (m);
512bad:
513 m_freem(n);
514 mbstat.m_mpfail++; /* XXX: No consistency. */
515 return (NULL);
516}
517
518/*
519 * Partition an mbuf chain in two pieces, returning the tail --
520 * all but the first len0 bytes. In case of failure, it returns NULL and
521 * attempts to restore the chain to its original state.
522 *
523 * Note that the resulting mbufs might be read-only, because the new
524 * mbuf can end up sharing an mbuf cluster with the original mbuf if
525 * the "breaking point" happens to lie within a cluster mbuf. Use the
526 * M_WRITABLE() macro to check for this case.
527 */
528struct mbuf *
529m_split(struct mbuf *m0, int len0, int wait)
530{
531 struct mbuf *m, *n;
|
532 unsigned len = len0, remain;
| 532 u_int len = len0, remain;
|
533
534 for (m = m0; m && len > m->m_len; m = m->m_next)
535 len -= m->m_len;
536 if (m == NULL)
537 return (NULL);
538 remain = m->m_len - len;
539 if (m0->m_flags & M_PKTHDR) {
540 MGETHDR(n, wait, m0->m_type);
541 if (n == NULL)
542 return (NULL);
543 n->m_pkthdr.rcvif = m0->m_pkthdr.rcvif;
544 n->m_pkthdr.len = m0->m_pkthdr.len - len0;
545 m0->m_pkthdr.len = len0;
546 if (m->m_flags & M_EXT)
547 goto extpacket;
548 if (remain > MHLEN) {
549 /* m can't be the lead packet */
550 MH_ALIGN(n, 0);
551 n->m_next = m_split(m, len, wait);
552 if (n->m_next == NULL) {
553 (void) m_free(n);
554 return (NULL);
555 } else {
556 n->m_len = 0;
557 return (n);
558 }
559 } else
560 MH_ALIGN(n, remain);
561 } else if (remain == 0) {
562 n = m->m_next;
563 m->m_next = NULL;
564 return (n);
565 } else {
566 MGET(n, wait, m->m_type);
567 if (n == NULL)
568 return (NULL);
569 M_ALIGN(n, remain);
570 }
571extpacket:
572 if (m->m_flags & M_EXT) {
573 n->m_flags |= M_EXT;
574 n->m_ext = m->m_ext;
575 MEXT_ADD_REF(m);
576 n->m_data = m->m_data + len;
577 } else {
578 bcopy(mtod(m, caddr_t) + len, mtod(n, caddr_t), remain);
579 }
580 n->m_len = remain;
581 m->m_len = len;
582 n->m_next = m->m_next;
583 m->m_next = NULL;
584 return (n);
585}
586/*
587 * Routine to copy from device local memory into mbufs.
588 * Note that `off' argument is offset into first mbuf of target chain from
589 * which to begin copying the data to.
590 */
591struct mbuf *
592m_devget(char *buf, int totlen, int off, struct ifnet *ifp,
593 void (*copy)(char *from, caddr_t to, u_int len))
594{
595 struct mbuf *m;
596 struct mbuf *top = 0, **mp = ⊤
597 int len;
598
599 if (off < 0 || off > MHLEN)
600 return (NULL);
601
602 MGETHDR(m, M_DONTWAIT, MT_DATA);
603 if (m == NULL)
604 return (NULL);
605 m->m_pkthdr.rcvif = ifp;
606 m->m_pkthdr.len = totlen;
607 len = MHLEN;
608
609 while (totlen > 0) {
610 if (top) {
611 MGET(m, M_DONTWAIT, MT_DATA);
612 if (m == NULL) {
613 m_freem(top);
614 return (NULL);
615 }
616 len = MLEN;
617 }
618 if (totlen + off >= MINCLSIZE) {
619 MCLGET(m, M_DONTWAIT);
620 if (m->m_flags & M_EXT)
621 len = MCLBYTES;
622 } else {
623 /*
624 * Place initial small packet/header at end of mbuf.
625 */
626 if (top == NULL && totlen + off + max_linkhdr <= len) {
627 m->m_data += max_linkhdr;
628 len -= max_linkhdr;
629 }
630 }
631 if (off) {
632 m->m_data += off;
633 len -= off;
634 off = 0;
635 }
636 m->m_len = len = min(totlen, len);
637 if (copy)
| 533
534 for (m = m0; m && len > m->m_len; m = m->m_next)
535 len -= m->m_len;
536 if (m == NULL)
537 return (NULL);
538 remain = m->m_len - len;
539 if (m0->m_flags & M_PKTHDR) {
540 MGETHDR(n, wait, m0->m_type);
541 if (n == NULL)
542 return (NULL);
543 n->m_pkthdr.rcvif = m0->m_pkthdr.rcvif;
544 n->m_pkthdr.len = m0->m_pkthdr.len - len0;
545 m0->m_pkthdr.len = len0;
546 if (m->m_flags & M_EXT)
547 goto extpacket;
548 if (remain > MHLEN) {
549 /* m can't be the lead packet */
550 MH_ALIGN(n, 0);
551 n->m_next = m_split(m, len, wait);
552 if (n->m_next == NULL) {
553 (void) m_free(n);
554 return (NULL);
555 } else {
556 n->m_len = 0;
557 return (n);
558 }
559 } else
560 MH_ALIGN(n, remain);
561 } else if (remain == 0) {
562 n = m->m_next;
563 m->m_next = NULL;
564 return (n);
565 } else {
566 MGET(n, wait, m->m_type);
567 if (n == NULL)
568 return (NULL);
569 M_ALIGN(n, remain);
570 }
571extpacket:
572 if (m->m_flags & M_EXT) {
573 n->m_flags |= M_EXT;
574 n->m_ext = m->m_ext;
575 MEXT_ADD_REF(m);
576 n->m_data = m->m_data + len;
577 } else {
578 bcopy(mtod(m, caddr_t) + len, mtod(n, caddr_t), remain);
579 }
580 n->m_len = remain;
581 m->m_len = len;
582 n->m_next = m->m_next;
583 m->m_next = NULL;
584 return (n);
585}
586/*
587 * Routine to copy from device local memory into mbufs.
588 * Note that `off' argument is offset into first mbuf of target chain from
589 * which to begin copying the data to.
590 */
591struct mbuf *
592m_devget(char *buf, int totlen, int off, struct ifnet *ifp,
593 void (*copy)(char *from, caddr_t to, u_int len))
594{
595 struct mbuf *m;
596 struct mbuf *top = 0, **mp = ⊤
597 int len;
598
599 if (off < 0 || off > MHLEN)
600 return (NULL);
601
602 MGETHDR(m, M_DONTWAIT, MT_DATA);
603 if (m == NULL)
604 return (NULL);
605 m->m_pkthdr.rcvif = ifp;
606 m->m_pkthdr.len = totlen;
607 len = MHLEN;
608
609 while (totlen > 0) {
610 if (top) {
611 MGET(m, M_DONTWAIT, MT_DATA);
612 if (m == NULL) {
613 m_freem(top);
614 return (NULL);
615 }
616 len = MLEN;
617 }
618 if (totlen + off >= MINCLSIZE) {
619 MCLGET(m, M_DONTWAIT);
620 if (m->m_flags & M_EXT)
621 len = MCLBYTES;
622 } else {
623 /*
624 * Place initial small packet/header at end of mbuf.
625 */
626 if (top == NULL && totlen + off + max_linkhdr <= len) {
627 m->m_data += max_linkhdr;
628 len -= max_linkhdr;
629 }
630 }
631 if (off) {
632 m->m_data += off;
633 len -= off;
634 off = 0;
635 }
636 m->m_len = len = min(totlen, len);
637 if (copy)
|
638 copy(buf, mtod(m, caddr_t), (unsigned)len);
| 638 copy(buf, mtod(m, caddr_t), (u_int)len);
|
639 else
| 639 else
|
640 bcopy(buf, mtod(m, caddr_t), (unsigned)len);
| 640 bcopy(buf, mtod(m, caddr_t), (u_int)len);
|
641 buf += len;
642 *mp = m;
643 mp = &m->m_next;
644 totlen -= len;
645 }
646 return (top);
647}
648
649/*
650 * Copy data from a buffer back into the indicated mbuf chain,
651 * starting "off" bytes from the beginning, extending the mbuf
652 * chain if necessary.
653 */
654void
655m_copyback(struct mbuf *m0, int off, int len, caddr_t cp)
656{
657 int mlen;
658 struct mbuf *m = m0, *n;
659 int totlen = 0;
660
661 if (m0 == NULL)
662 return;
663 while (off > (mlen = m->m_len)) {
664 off -= mlen;
665 totlen += mlen;
666 if (m->m_next == NULL) {
667 n = m_get_clrd(M_DONTWAIT, m->m_type);
668 if (n == NULL)
669 goto out;
670 n->m_len = min(MLEN, len + off);
671 m->m_next = n;
672 }
673 m = m->m_next;
674 }
675 while (len > 0) {
676 mlen = min (m->m_len - off, len);
| 641 buf += len;
642 *mp = m;
643 mp = &m->m_next;
644 totlen -= len;
645 }
646 return (top);
647}
648
649/*
650 * Copy data from a buffer back into the indicated mbuf chain,
651 * starting "off" bytes from the beginning, extending the mbuf
652 * chain if necessary.
653 */
654void
655m_copyback(struct mbuf *m0, int off, int len, caddr_t cp)
656{
657 int mlen;
658 struct mbuf *m = m0, *n;
659 int totlen = 0;
660
661 if (m0 == NULL)
662 return;
663 while (off > (mlen = m->m_len)) {
664 off -= mlen;
665 totlen += mlen;
666 if (m->m_next == NULL) {
667 n = m_get_clrd(M_DONTWAIT, m->m_type);
668 if (n == NULL)
669 goto out;
670 n->m_len = min(MLEN, len + off);
671 m->m_next = n;
672 }
673 m = m->m_next;
674 }
675 while (len > 0) {
676 mlen = min (m->m_len - off, len);
|
677 bcopy(cp, off + mtod(m, caddr_t), (unsigned)mlen);
| 677 bcopy(cp, off + mtod(m, caddr_t), (u_int)mlen);
|
678 cp += mlen;
679 len -= mlen;
680 mlen += off;
681 off = 0;
682 totlen += mlen;
683 if (len == 0)
684 break;
685 if (m->m_next == NULL) {
686 n = m_get(M_DONTWAIT, m->m_type);
687 if (n == NULL)
688 break;
689 n->m_len = min(MLEN, len);
690 m->m_next = n;
691 }
692 m = m->m_next;
693 }
694out: if (((m = m0)->m_flags & M_PKTHDR) && (m->m_pkthdr.len < totlen))
695 m->m_pkthdr.len = totlen;
696}
697
698void
699m_print(const struct mbuf *m)
700{
701 int len;
702 const struct mbuf *m2;
703
704 len = m->m_pkthdr.len;
705 m2 = m;
706 while (len) {
707 printf("%p %*D\n", m2, m2->m_len, (u_char *)m2->m_data, "-");
708 len -= m2->m_len;
709 m2 = m2->m_next;
710 }
711 return;
712}
713
| 678 cp += mlen;
679 len -= mlen;
680 mlen += off;
681 off = 0;
682 totlen += mlen;
683 if (len == 0)
684 break;
685 if (m->m_next == NULL) {
686 n = m_get(M_DONTWAIT, m->m_type);
687 if (n == NULL)
688 break;
689 n->m_len = min(MLEN, len);
690 m->m_next = n;
691 }
692 m = m->m_next;
693 }
694out: if (((m = m0)->m_flags & M_PKTHDR) && (m->m_pkthdr.len < totlen))
695 m->m_pkthdr.len = totlen;
696}
697
698void
699m_print(const struct mbuf *m)
700{
701 int len;
702 const struct mbuf *m2;
703
704 len = m->m_pkthdr.len;
705 m2 = m;
706 while (len) {
707 printf("%p %*D\n", m2, m2->m_len, (u_char *)m2->m_data, "-");
708 len -= m2->m_len;
709 m2 = m2->m_next;
710 }
711 return;
712}
713
|
714unsigned
| 714u_int
|
715m_fixhdr(struct mbuf *m0)
716{
| 715m_fixhdr(struct mbuf *m0)
716{
|
717 unsigned len;
| 717 u_int len;
|
718
719 len = m_length(m0, NULL);
720 m0->m_pkthdr.len = len;
721 return (len);
722}
723
| 718
719 len = m_length(m0, NULL);
720 m0->m_pkthdr.len = len;
721 return (len);
722}
723
|
724unsigned
| 724u_int
|
725m_length(struct mbuf *m0, struct mbuf **last)
726{
727 struct mbuf *m;
| 725m_length(struct mbuf *m0, struct mbuf **last)
726{
727 struct mbuf *m;
|
728 unsigned len;
| 728 u_int len;
|
729
730 len = 0;
731 for (m = m0; m != NULL; m = m->m_next) {
732 len += m->m_len;
733 if (m->m_next == NULL)
734 break;
735 }
736 if (last != NULL)
737 *last = m;
738 return (len);
739}
| 729
730 len = 0;
731 for (m = m0; m != NULL; m = m->m_next) {
732 len += m->m_len;
733 if (m->m_next == NULL)
734 break;
735 }
736 if (last != NULL)
737 *last = m;
738 return (len);
739}
|