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
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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 "opt_param.h"
35 #include <sys/param.h>
36 #include <sys/systm.h>
38 #include <sys/socket.h>
41 #include <netinet/in.h>
42 #include <netipsec/ipsec.h>
45 * Make space for a new header of length hlen at skip bytes
46 * into the packet. When doing this we allocate new mbufs only
47 * when absolutely necessary. The mbuf where the new header
48 * is to go is returned together with an offset into the mbuf.
49 * If NULL is returned then the mbuf chain may have been modified;
50 * the caller is assumed to always free the chain.
53 m_makespace(struct mbuf *m0, int skip, int hlen, int *off)
58 IPSEC_ASSERT(m0 != NULL, ("null mbuf"));
59 IPSEC_ASSERT(hlen < MHLEN, ("hlen too big: %u", hlen));
61 for (m = m0; m && skip > m->m_len; m = m->m_next)
66 * At this point skip is the offset into the mbuf m
67 * where the new header should be placed. Figure out
68 * if there's space to insert the new header. If so,
69 * and copying the remainder makes sense then do so.
70 * Otherwise insert a new mbuf in the chain, splitting
71 * the contents of m as needed.
73 remain = m->m_len - skip; /* data to move */
74 if (hlen > M_TRAILINGSPACE(m)) {
75 struct mbuf *n0, *n, **np;
76 int todo, len, done, alloc;
85 n = m_getcl(M_NOWAIT, m->m_type, 0);
89 n = m_get(M_NOWAIT, m->m_type);
100 memcpy(n->m_data, mtod(m, char *) + skip + done, len);
106 if (hlen <= M_TRAILINGSPACE(m) + remain) {
107 m->m_len = skip + hlen;
115 n = m_get(M_NOWAIT, m->m_type);
122 if ((n->m_next = n0) == NULL)
132 m = n; /* header is at front ... */
133 *off = 0; /* ... of new mbuf */
135 IPSECSTAT_INC(ips_mbinserted);
138 * Copy the remainder to the back of the mbuf
139 * so there's space to write the new header.
141 bcopy(mtod(m, caddr_t) + skip,
142 mtod(m, caddr_t) + skip + hlen, remain);
146 m0->m_pkthdr.len += hlen; /* adjust packet length */
151 * m_pad(m, n) pads <m> with <n> bytes at the end. The packet header
152 * length is updated, and a pointer to the first byte of the padding
153 * (which is guaranteed to be all in one mbuf) is returned.
156 m_pad(struct mbuf *m, int n)
158 register struct mbuf *m0, *m1;
159 register int len, pad;
162 if (n <= 0) { /* No stupid arguments. */
163 DPRINTF(("%s: pad length invalid (%d)\n", __func__, n));
168 len = m->m_pkthdr.len;
172 while (m0->m_len < len) {
177 if (m0->m_len != len) {
178 DPRINTF(("%s: length mismatch (should be %d instead of %d)\n",
179 __func__, m->m_pkthdr.len,
180 m->m_pkthdr.len + m0->m_len - len));
186 /* Check for zero-length trailing mbufs, and find the last one. */
187 for (m1 = m0; m1->m_next; m1 = m1->m_next) {
188 if (m1->m_next->m_len != 0) {
189 DPRINTF(("%s: length mismatch (should be %d instead "
190 "of %d)\n", __func__,
192 m->m_pkthdr.len + m1->m_next->m_len));
201 if (pad > M_TRAILINGSPACE(m0)) {
202 /* Add an mbuf to the chain. */
203 MGET(m1, M_NOWAIT, MT_DATA);
206 DPRINTF(("%s: unable to get extra mbuf\n", __func__));
215 retval = m0->m_data + m0->m_len;
217 m->m_pkthdr.len += pad;
223 * Remove hlen data at offset skip in the packet. This is used by
224 * the protocols strip protocol headers and associated data (e.g. IV,
225 * authenticator) on input.
228 m_striphdr(struct mbuf *m, int skip, int hlen)
233 /* Find beginning of header */
234 m1 = m_getptr(m, skip, &roff);
238 /* Remove the header and associated data from the mbuf. */
240 /* The header was at the beginning of the mbuf */
241 IPSECSTAT_INC(ips_input_front);
243 if ((m1->m_flags & M_PKTHDR) == 0)
244 m->m_pkthdr.len -= hlen;
245 } else if (roff + hlen >= m1->m_len) {
249 * Part or all of the header is at the end of this mbuf,
250 * so first let's remove the remainder of the header from
251 * the beginning of the remainder of the mbuf chain, if any.
253 IPSECSTAT_INC(ips_input_end);
254 if (roff + hlen > m1->m_len) {
255 /* Adjust the next mbuf by the remainder */
256 m_adj(m1->m_next, roff + hlen - m1->m_len);
258 /* The second mbuf is guaranteed not to have a pkthdr... */
259 m->m_pkthdr.len -= (roff + hlen - m1->m_len);
262 /* Now, let's unlink the mbuf chain for a second...*/
266 /* ...and trim the end of the first part of the chain...sick */
267 m_adj(m1, -(m1->m_len - roff));
268 if ((m1->m_flags & M_PKTHDR) == 0)
269 m->m_pkthdr.len -= (m1->m_len - roff);
271 /* Finally, let's relink */
275 * The header lies in the "middle" of the mbuf; copy
276 * the remainder of the mbuf down over the header.
278 IPSECSTAT_INC(ips_input_middle);
279 bcopy(mtod(m1, u_char *) + roff + hlen,
280 mtod(m1, u_char *) + roff,
281 m1->m_len - (roff + hlen));
283 m->m_pkthdr.len -= hlen;
289 * Diagnostic routine to check mbuf alignment as required by the
290 * crypto device drivers (that use DMA).
293 m_checkalignment(const char* where, struct mbuf *m0, int off, int len)
296 struct mbuf *m = m_getptr(m0, off, &roff);
301 printf("%s (off %u len %u): ", where, off, len);
302 addr = mtod(m, caddr_t) + roff;
306 if (((uintptr_t) addr) & 3) {
307 printf("addr misaligned %p,", addr);
314 if (len && (mlen & 3)) {
315 printf("len mismatch %u,", mlen);
319 addr = m ? mtod(m, caddr_t) : NULL;
320 } while (m && len > 0);
321 for (m = m0; m; m = m->m_next)
322 printf(" [%p:%u]", mtod(m, caddr_t), m->m_len);