2 * Copyright (c) 2002, 2003 Sam Leffler, Errno Consulting
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * IPsec-specific mbuf routines.
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/malloc.h>
37 #include <sys/socket.h>
40 #include <netinet/in.h>
41 #include <netipsec/ipsec.h>
44 * Make space for a new header of length hlen at skip bytes
45 * into the packet. When doing this we allocate new mbufs only
46 * when absolutely necessary. The mbuf where the new header
47 * is to go is returned together with an offset into the mbuf.
48 * If NULL is returned then the mbuf chain may have been modified;
49 * the caller is assumed to always free the chain.
52 m_makespace(struct mbuf *m0, int skip, int hlen, int *off)
57 IPSEC_ASSERT(m0 != NULL, ("null mbuf"));
58 IPSEC_ASSERT(hlen < MHLEN, ("hlen too big: %u", hlen));
60 for (m = m0; m && skip > m->m_len; m = m->m_next)
65 * At this point skip is the offset into the mbuf m
66 * where the new header should be placed. Figure out
67 * if there's space to insert the new header. If so,
68 * and copying the remainder makes sense then do so.
69 * Otherwise insert a new mbuf in the chain, splitting
70 * the contents of m as needed.
72 remain = m->m_len - skip; /* data to move */
74 hlen + max_linkhdr < M_LEADINGSPACE(m)) {
76 * mbuf has enough free space at the beginning.
77 * XXX: which operation is the most heavy - copying of
78 * possible several hundred of bytes or allocation
79 * of new mbuf? We can remove max_linkhdr check
80 * here, but it is possible that this will lead
81 * to allocation of new mbuf in Layer 2 code.
84 bcopy(mtodo(m, hlen), mtod(m, caddr_t), skip);
87 } else if (hlen > M_TRAILINGSPACE(m)) {
88 struct mbuf *n0, *n, **np;
89 int todo, len, done, alloc;
98 n = m_getcl(M_NOWAIT, m->m_type, 0);
102 n = m_get(M_NOWAIT, m->m_type);
112 len = min(todo, len);
113 memcpy(n->m_data, mtod(m, char *) + skip + done, len);
119 if (hlen <= M_TRAILINGSPACE(m) + remain) {
120 m->m_len = skip + hlen;
128 n = m_get(M_NOWAIT, m->m_type);
135 if ((n->m_next = n0) == NULL)
145 m = n; /* header is at front ... */
146 *off = 0; /* ... of new mbuf */
148 IPSECSTAT_INC(ips_mbinserted);
151 * Copy the remainder to the back of the mbuf
152 * so there's space to write the new header.
154 bcopy(mtod(m, caddr_t) + skip,
155 mtod(m, caddr_t) + skip + hlen, remain);
159 m0->m_pkthdr.len += hlen; /* adjust packet length */
164 * m_pad(m, n) pads <m> with <n> bytes at the end. The packet header
165 * length is updated, and a pointer to the first byte of the padding
166 * (which is guaranteed to be all in one mbuf) is returned.
169 m_pad(struct mbuf *m, int n)
171 register struct mbuf *m0, *m1;
172 register int len, pad;
175 if (n <= 0) { /* No stupid arguments. */
176 DPRINTF(("%s: pad length invalid (%d)\n", __func__, n));
181 len = m->m_pkthdr.len;
185 while (m0->m_len < len) {
190 if (m0->m_len != len) {
191 DPRINTF(("%s: length mismatch (should be %d instead of %d)\n",
192 __func__, m->m_pkthdr.len,
193 m->m_pkthdr.len + m0->m_len - len));
199 /* Check for zero-length trailing mbufs, and find the last one. */
200 for (m1 = m0; m1->m_next; m1 = m1->m_next) {
201 if (m1->m_next->m_len != 0) {
202 DPRINTF(("%s: length mismatch (should be %d instead "
203 "of %d)\n", __func__,
205 m->m_pkthdr.len + m1->m_next->m_len));
214 if (pad > M_TRAILINGSPACE(m0)) {
215 /* Add an mbuf to the chain. */
216 MGET(m1, M_NOWAIT, MT_DATA);
219 DPRINTF(("%s: unable to get extra mbuf\n", __func__));
228 retval = m0->m_data + m0->m_len;
230 m->m_pkthdr.len += pad;
236 * Remove hlen data at offset skip in the packet. This is used by
237 * the protocols strip protocol headers and associated data (e.g. IV,
238 * authenticator) on input.
241 m_striphdr(struct mbuf *m, int skip, int hlen)
246 /* Find beginning of header */
247 m1 = m_getptr(m, skip, &roff);
251 /* Remove the header and associated data from the mbuf. */
253 /* The header was at the beginning of the mbuf */
254 IPSECSTAT_INC(ips_input_front);
256 if ((m1->m_flags & M_PKTHDR) == 0)
257 m->m_pkthdr.len -= hlen;
258 } else if (roff + hlen >= m1->m_len) {
262 * Part or all of the header is at the end of this mbuf,
263 * so first let's remove the remainder of the header from
264 * the beginning of the remainder of the mbuf chain, if any.
266 IPSECSTAT_INC(ips_input_end);
267 if (roff + hlen > m1->m_len) {
268 /* Adjust the next mbuf by the remainder */
269 m_adj(m1->m_next, roff + hlen - m1->m_len);
271 /* The second mbuf is guaranteed not to have a pkthdr... */
272 m->m_pkthdr.len -= (roff + hlen - m1->m_len);
275 /* Now, let's unlink the mbuf chain for a second...*/
279 /* ...and trim the end of the first part of the chain...sick */
280 m_adj(m1, -(m1->m_len - roff));
281 if ((m1->m_flags & M_PKTHDR) == 0)
282 m->m_pkthdr.len -= (m1->m_len - roff);
284 /* Finally, let's relink */
288 * The header lies in the "middle" of the mbuf; copy
289 * the remainder of the mbuf down over the header.
291 IPSECSTAT_INC(ips_input_middle);
292 bcopy(mtod(m1, u_char *) + roff + hlen,
293 mtod(m1, u_char *) + roff,
294 m1->m_len - (roff + hlen));
296 m->m_pkthdr.len -= hlen;
302 * Diagnostic routine to check mbuf alignment as required by the
303 * crypto device drivers (that use DMA).
306 m_checkalignment(const char* where, struct mbuf *m0, int off, int len)
309 struct mbuf *m = m_getptr(m0, off, &roff);
314 printf("%s (off %u len %u): ", where, off, len);
315 addr = mtod(m, caddr_t) + roff;
319 if (((uintptr_t) addr) & 3) {
320 printf("addr misaligned %p,", addr);
327 if (len && (mlen & 3)) {
328 printf("len mismatch %u,", mlen);
332 addr = m ? mtod(m, caddr_t) : NULL;
333 } while (m && len > 0);
334 for (m = m0; m; m = m->m_next)
335 printf(" [%p:%u]", mtod(m, caddr_t), m->m_len);