ipsec_mbuf.c

Version: - FREEBSD - FREEBSD-13-STABLE - FREEBSD-13-0 - FREEBSD-12-STABLE - FREEBSD-12-0 - FREEBSD-11-STABLE - FREEBSD-11-0 - FREEBSD-10-STABLE - FREEBSD-10-0 - FREEBSD-9-STABLE - FREEBSD-9-0 - FREEBSD-8-STABLE - FREEBSD-8-0 - FREEBSD-7-STABLE - FREEBSD-7-0 - FREEBSD-6-STABLE - FREEBSD-6-0 - FREEBSD-5-STABLE - FREEBSD-5-0 - FREEBSD-4-STABLE - FREEBSD-3-STABLE - FREEBSD22 - l41 - OPENBSD - linux-2.6 - MK84 - PLAN9 - xnu-8792
SearchContext: - none - 3 - 10
    1 /*-
    2  * Copyright (c) 2002, 2003 Sam Leffler, Errno Consulting
    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  *
   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
   24  * SUCH DAMAGE.
   25  *
   26  * $FreeBSD$
   27  */
   28 
   29 /*
   30  * IPsec-specific mbuf routines.
   31  */
   32 
   33 #include "opt_ipsec.h"
   34 
   35 #include <sys/param.h>
   36 #include <sys/systm.h>
   37 #include <sys/malloc.h>
   38 #include <sys/mbuf.h>
   39 #include <sys/socket.h>
   40 
   41 #include <net/vnet.h>
   42 #include <netinet/in.h>
   43 #include <netipsec/ipsec.h>
   44 
   45 /*
   46  * Make space for a new header of length hlen at skip bytes
   47  * into the packet.  When doing this we allocate new mbufs only
   48  * when absolutely necessary.  The mbuf where the new header
   49  * is to go is returned together with an offset into the mbuf.
   50  * If NULL is returned then the mbuf chain may have been modified;
   51  * the caller is assumed to always free the chain.
   52  */
   53 struct mbuf *
   54 m_makespace(struct mbuf *m0, int skip, int hlen, int *off)
   55 {
   56         struct mbuf *m;
   57         unsigned remain;
   58 
   59         IPSEC_ASSERT(m0 != NULL, ("null mbuf"));
   60         IPSEC_ASSERT(hlen < MHLEN, ("hlen too big: %u", hlen));
   61 
   62         for (m = m0; m && skip > m->m_len; m = m->m_next)
   63                 skip -= m->m_len;
   64         if (m == NULL)
   65                 return (NULL);
   66         /*
   67          * At this point skip is the offset into the mbuf m
   68          * where the new header should be placed.  Figure out
   69          * if there's space to insert the new header.  If so,
   70          * and copying the remainder makes sense then do so.
   71          * Otherwise insert a new mbuf in the chain, splitting
   72          * the contents of m as needed.
   73          */
   74         remain = m->m_len - skip;               /* data to move */
   75         if (remain > skip &&
   76             hlen + max_linkhdr < M_LEADINGSPACE(m)) {
   77                 /*
   78                  * mbuf has enough free space at the beginning.
   79                  * XXX: which operation is the most heavy - copying of
   80                  *      possible several hundred of bytes or allocation
   81                  *      of new mbuf? We can remove max_linkhdr check
   82                  *      here, but it is possible that this will lead
   83                  *      to allocation of new mbuf in Layer 2 code.
   84                  */
   85                 m->m_data -= hlen;
   86                 bcopy(mtodo(m, hlen), mtod(m, caddr_t), skip);
   87                 m->m_len += hlen;
   88                 *off = skip;
   89         } else if (hlen > M_TRAILINGSPACE(m)) {
   90                 struct mbuf *n0, *n, **np;
   91                 int todo, len, done, alloc;
   92 
   93                 n0 = NULL;
   94                 np = &n0;
   95                 alloc = 0;
   96                 done = 0;
   97                 todo = remain;
   98                 while (todo > 0) {
   99                         if (todo > MHLEN) {
  100                                 n = m_getcl(M_NOWAIT, m->m_type, 0);
  101                                 len = MCLBYTES;
  102                         }
  103                         else {
  104                                 n = m_get(M_NOWAIT, m->m_type);
  105                                 len = MHLEN;
  106                         }
  107                         if (n == NULL) {
  108                                 m_freem(n0);
  109                                 return NULL;
  110                         }
  111                         *np = n;
  112                         np = &n->m_next;
  113                         alloc++;
  114                         len = min(todo, len);
  115                         memcpy(n->m_data, mtod(m, char *) + skip + done, len);
  116                         n->m_len = len;
  117                         done += len;
  118                         todo -= len;
  119                 }
  120 
  121                 if (hlen <= M_TRAILINGSPACE(m) + remain) {
  122                         m->m_len = skip + hlen;
  123                         *off = skip;
  124                         if (n0 != NULL) {
  125                                 *np = m->m_next;
  126                                 m->m_next = n0;
  127                         }
  128                 }
  129                 else {
  130                         n = m_get(M_NOWAIT, m->m_type);
  131                         if (n == NULL) {
  132                                 m_freem(n0);
  133                                 return NULL;
  134                         }
  135                         alloc++;
  136 
  137                         if ((n->m_next = n0) == NULL)
  138                                 np = &n->m_next;
  139                         n0 = n;
  140 
  141                         *np = m->m_next;
  142                         m->m_next = n0;
  143 
  144                         n->m_len = hlen;
  145                         m->m_len = skip;
  146 
  147                         m = n;                  /* header is at front ... */
  148                         *off = 0;               /* ... of new mbuf */
  149                 }
  150                 IPSECSTAT_INC(ips_mbinserted);
  151         } else {
  152                 /*
  153                  * Copy the remainder to the back of the mbuf
  154                  * so there's space to write the new header.
  155                  */
  156                 bcopy(mtod(m, caddr_t) + skip,
  157                     mtod(m, caddr_t) + skip + hlen, remain);
  158                 m->m_len += hlen;
  159                 *off = skip;
  160         }
  161         m0->m_pkthdr.len += hlen;               /* adjust packet length */
  162         return m;
  163 }
  164 
  165 /*
  166  * m_pad(m, n) pads <m> with <n> bytes at the end. The packet header
  167  * length is updated, and a pointer to the first byte of the padding
  168  * (which is guaranteed to be all in one mbuf) is returned.
  169  */
  170 caddr_t
  171 m_pad(struct mbuf *m, int n)
  172 {
  173         struct mbuf *m0, *m1;
  174         int len, pad;
  175         caddr_t retval;
  176 
  177         if (n <= 0) {  /* No stupid arguments. */
  178                 DPRINTF(("%s: pad length invalid (%d)\n", __func__, n));
  179                 m_freem(m);
  180                 return NULL;
  181         }
  182 
  183         len = m->m_pkthdr.len;
  184         pad = n;
  185         m0 = m;
  186 
  187         while (m0->m_len < len) {
  188                 len -= m0->m_len;
  189                 m0 = m0->m_next;
  190         }
  191 
  192         if (m0->m_len != len) {
  193                 DPRINTF(("%s: length mismatch (should be %d instead of %d)\n",
  194                         __func__, m->m_pkthdr.len,
  195                         m->m_pkthdr.len + m0->m_len - len));
  196 
  197                 m_freem(m);
  198                 return NULL;
  199         }
  200 
  201         /* Check for zero-length trailing mbufs, and find the last one. */
  202         for (m1 = m0; m1->m_next; m1 = m1->m_next) {
  203                 if (m1->m_next->m_len != 0) {
  204                         DPRINTF(("%s: length mismatch (should be %d instead "
  205                                 "of %d)\n", __func__,
  206                                 m->m_pkthdr.len,
  207                                 m->m_pkthdr.len + m1->m_next->m_len));
  208 
  209                         m_freem(m);
  210                         return NULL;
  211                 }
  212 
  213                 m0 = m1->m_next;
  214         }
  215 
  216         if (pad > M_TRAILINGSPACE(m0)) {
  217                 /* Add an mbuf to the chain. */
  218                 MGET(m1, M_NOWAIT, MT_DATA);
  219                 if (m1 == NULL) {
  220                         m_freem(m0);
  221                         DPRINTF(("%s: unable to get extra mbuf\n", __func__));
  222                         return NULL;
  223                 }
  224 
  225                 m0->m_next = m1;
  226                 m0 = m1;
  227                 m0->m_len = 0;
  228         }
  229 
  230         retval = m0->m_data + m0->m_len;
  231         m0->m_len += pad;
  232         m->m_pkthdr.len += pad;
  233 
  234         return retval;
  235 }
  236 
  237 /*
  238  * Remove hlen data at offset skip in the packet.  This is used by
  239  * the protocols strip protocol headers and associated data (e.g. IV,
  240  * authenticator) on input.
  241  */
  242 int
  243 m_striphdr(struct mbuf *m, int skip, int hlen)
  244 {
  245         struct mbuf *m1;
  246         int roff;
  247 
  248         /* Find beginning of header */
  249         m1 = m_getptr(m, skip, &roff);
  250         if (m1 == NULL)
  251                 return (EINVAL);
  252 
  253         /* Remove the header and associated data from the mbuf. */
  254         if (roff == 0) {
  255                 /* The header was at the beginning of the mbuf */
  256                 IPSECSTAT_INC(ips_input_front);
  257                 m_adj(m1, hlen);
  258                 if (m1 != m)
  259                         m->m_pkthdr.len -= hlen;
  260         } else if (roff + hlen >= m1->m_len) {
  261                 struct mbuf *mo;
  262                 int adjlen;
  263 
  264                 /*
  265                  * Part or all of the header is at the end of this mbuf,
  266                  * so first let's remove the remainder of the header from
  267                  * the beginning of the remainder of the mbuf chain, if any.
  268                  */
  269                 IPSECSTAT_INC(ips_input_end);
  270                 if (roff + hlen > m1->m_len) {
  271                         adjlen = roff + hlen - m1->m_len;
  272 
  273                         /* Adjust the next mbuf by the remainder */
  274                         m_adj(m1->m_next, adjlen);
  275 
  276                         /* The second mbuf is guaranteed not to have a pkthdr... */
  277                         m->m_pkthdr.len -= adjlen;
  278                 }
  279 
  280                 /* Now, let's unlink the mbuf chain for a second...*/
  281                 mo = m1->m_next;
  282                 m1->m_next = NULL;
  283 
  284                 /* ...and trim the end of the first part of the chain...sick */
  285                 adjlen = m1->m_len - roff;
  286                 m_adj(m1, -adjlen);
  287                 if (m1 != m)
  288                         m->m_pkthdr.len -= adjlen;
  289 
  290                 /* Finally, let's relink */
  291                 m1->m_next = mo;
  292         } else {
  293                 /*
  294                  * The header lies in the "middle" of the mbuf; copy
  295                  * the remainder of the mbuf down over the header.
  296                  */
  297                 IPSECSTAT_INC(ips_input_middle);
  298                 bcopy(mtod(m1, u_char *) + roff + hlen,
  299                       mtod(m1, u_char *) + roff,
  300                       m1->m_len - (roff + hlen));
  301                 m1->m_len -= hlen;
  302                 m->m_pkthdr.len -= hlen;
  303         }
  304         return (0);
  305 }
  306 
  307 /*
  308  * Diagnostic routine to check mbuf alignment as required by the
  309  * crypto device drivers (that use DMA).
  310  */
  311 void
  312 m_checkalignment(const char* where, struct mbuf *m0, int off, int len)
  313 {
  314         int roff;
  315         struct mbuf *m = m_getptr(m0, off, &roff);
  316         caddr_t addr;
  317 
  318         if (m == NULL)
  319                 return;
  320         printf("%s (off %u len %u): ", where, off, len);
  321         addr = mtod(m, caddr_t) + roff;
  322         do {
  323                 int mlen;
  324 
  325                 if (((uintptr_t) addr) & 3) {
  326                         printf("addr misaligned %p,", addr);
  327                         break;
  328                 }
  329                 mlen = m->m_len;
  330                 if (mlen > len)
  331                         mlen = len;
  332                 len -= mlen;
  333                 if (len && (mlen & 3)) {
  334                         printf("len mismatch %u,", mlen);
  335                         break;
  336                 }
  337                 m = m->m_next;
  338                 addr = m ? mtod(m, caddr_t) : NULL;
  339         } while (m && len > 0);
  340         for (m = m0; m; m = m->m_next)
  341                 printf(" [%p:%u]", mtod(m, caddr_t), m->m_len);
  342         printf("\n");
  343 }
Cache object: 8e936571640f04cbb50b44a89b8ff03f
[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]
This page is part of the FreeBSD/Linux Linux Kernel Cross-Reference, and was automatically generated using a modified version of the LXR engine.
FreeBSD/Linux Kernel Cross Reference sys/netipsec/ipsec_mbuf.c

FreeBSD/Linux Kernel Cross Reference
sys/netipsec/ipsec_mbuf.c
