sys/netinet6/in6_offload.c

   1 /*      $NetBSD$        */
   2
   3 /*-
   4  * Copyright (c)2006 YAMAMOTO Takashi,
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  26  * SUCH DAMAGE.
  27  */
  28
  29 #include <sys/cdefs.h>
  30 __KERNEL_RCSID(0, "$NetBSD: in6_offload.c,v 1.3 2007/04/25 20:40:20 dyoung Exp $");
  31
  32 #include <sys/param.h>
  33 #include <sys/mbuf.h>
  34
  35 #include <net/if.h>
  36
  37 #include <netinet/in.h>
  38 #include <netinet/in_systm.h>
  39 #include <netinet/ip6.h>
  40 #include <netinet/tcp.h>
  41 #include <netinet6/in6_var.h>
  42 #include <netinet6/nd6.h>
  43 #include <netinet6/in6_offload.h>
  44
  45 struct ip6_tso_output_args {
  46         struct ifnet *ifp;
  47         struct ifnet *origifp;
  48         const struct sockaddr_in6 *dst;
  49         struct rtentry *rt;
  50 };
  51
  52 static int ip6_tso_output_callback(void *, struct mbuf *);
  53
  54 static int
  55 ip6_tso_output_callback(void *vp, struct mbuf *m)
  56 {
  57         struct ip6_tso_output_args *args = vp;
  58
  59         return nd6_output(args->ifp, args->origifp, m, args->dst, args->rt);
  60 }
  61
  62 int
  63 ip6_tso_output(struct ifnet *ifp, struct ifnet *origifp, struct mbuf *m,
  64     const struct sockaddr_in6 *dst, struct rtentry *rt)
  65 {
  66         struct ip6_tso_output_args args;
  67
  68         args.ifp = ifp;
  69         args.origifp = origifp;
  70         args.dst = dst;
  71         args.rt = rt;
  72
  73         return tcp6_segment(m, ip6_tso_output_callback, &args);
  74 }
  75
  76 /*
  77  * tcp6_segment: handle M_CSUM_TSOv6 by software.
  78  *
  79  * => always consume m.
  80  * => call output_func with output_arg for each segments.
  81  */
  82
  83 int
  84 tcp6_segment(struct mbuf *m, int (*output_func)(void *, struct mbuf *),
  85     void *output_arg)
  86 {
  87         int mss;
  88         int iphlen;
  89         int thlen;
  90         int hlen;
  91         int len;
  92         struct ip6_hdr *iph;
  93         struct tcphdr *th;
  94         uint32_t tcpseq;
  95         struct mbuf *hdr = NULL;
  96         struct mbuf *t;
  97         int error = 0;
  98
  99         KASSERT((m->m_flags & M_PKTHDR) != 0);
 100         KASSERT((m->m_pkthdr.csum_flags & M_CSUM_TSOv6) != 0);
 101
 102         m->m_pkthdr.csum_flags = 0;
 103
 104         len = m->m_pkthdr.len;
 105         KASSERT(len >= sizeof(*iph) + sizeof(*th));
 106
 107         if (m->m_len < sizeof(*iph)) {
 108                 m = m_pullup(m, sizeof(*iph));
 109                 if (m == NULL) {
 110                         error = ENOMEM;
 111                         goto quit;
 112                 }
 113         }
 114         iph = mtod(m, struct ip6_hdr *);
 115         iphlen = sizeof(*iph);
 116         KASSERT((iph->ip6_vfc & IPV6_VERSION_MASK) == IPV6_VERSION);
 117         KASSERT(iph->ip6_nxt == IPPROTO_TCP);
 118
 119         hlen = iphlen + sizeof(*th);
 120         if (m->m_len < hlen) {
 121                 m = m_pullup(m, hlen);
 122                 if (m == NULL) {
 123                         error = ENOMEM;
 124                         goto quit;
 125                 }
 126         }
 127         th = (void *)(mtod(m, char *) + iphlen);
 128         tcpseq = ntohl(th->th_seq);
 129         thlen = th->th_off * 4;
 130         hlen = iphlen + thlen;
 131
 132         mss = m->m_pkthdr.segsz;
 133         KASSERT(mss != 0);
 134         KASSERT(len > hlen);
 135
 136         t = m_split(m, hlen, M_NOWAIT);
 137         if (t == NULL) {
 138                 error = ENOMEM;
 139                 goto quit;
 140         }
 141         hdr = m;
 142         m = t;
 143         len -= hlen;
 144         KASSERT(len % mss == 0);
 145         while (len > 0) {
 146                 struct mbuf *n;
 147
 148                 n = m_dup(hdr, 0, hlen, M_NOWAIT);
 149                 if (n == NULL) {
 150                         error = ENOMEM;
 151                         goto quit;
 152                 }
 153                 KASSERT(n->m_len == hlen); /* XXX */
 154
 155                 t = m_split(m, mss, M_NOWAIT);
 156                 if (t == NULL) {
 157                         m_freem(n);
 158                         error = ENOMEM;
 159                         goto quit;
 160                 }
 161                 m_cat(n, m);
 162                 m = t;
 163
 164                 KASSERT(n->m_len >= hlen); /* XXX */
 165
 166                 n->m_pkthdr.len = hlen + mss;
 167                 iph = mtod(n, struct ip6_hdr *);
 168                 KASSERT((iph->ip6_vfc & IPV6_VERSION_MASK) == IPV6_VERSION);
 169                 iph->ip6_plen = htons(thlen + mss);
 170                 th = (void *)(mtod(n, char *) + iphlen);
 171                 th->th_seq = htonl(tcpseq);
 172                 th->th_sum = 0;
 173                 th->th_sum = in6_cksum(n, IPPROTO_TCP, iphlen, thlen + mss);
 174
 175                 error = (*output_func)(output_arg, n);
 176                 if (error) {
 177                         goto quit;
 178                 }
 179
 180                 tcpseq += mss;
 181                 len -= mss;
 182         }
 183
 184 quit:
 185         if (hdr != NULL) {
 186                 m_freem(hdr);
 187         }
 188         if (m != NULL) {
 189                 m_freem(m);
 190         }
 191
 192         return error;
 193 }