sys/netinet/in_offload.c

   1 /*      $NetBSD: in_offload.c,v 1.1 2006/11/25 18:41:36 yamt Exp $      */
   2
   3 /*-
   4  * Copyright (c)2005, 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: in_offload.c,v 1.1 2006/11/25 18:41:36 yamt 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/ip.h>
  40 #include <netinet/tcp.h>
  41 #include <netinet/in_offload.h>
  42
  43 struct ip_tso_output_args {
  44         struct ifnet *ifp;
  45         const struct sockaddr *sa;
  46         struct rtentry *rt;
  47 };
  48
  49 static int ip_tso_output_callback(void *, struct mbuf *);
  50
  51 static int
  52 ip_tso_output_callback(void *vp, struct mbuf *m)
  53 {
  54         struct ip_tso_output_args *args = vp;
  55         struct ifnet *ifp = args->ifp;
  56
  57         return (*ifp->if_output)(ifp, m, args->sa, args->rt);
  58 }
  59
  60 int
  61 ip_tso_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *sa,
  62     struct rtentry *rt)
  63 {
  64         struct ip_tso_output_args args;
  65
  66         args.ifp = ifp;
  67         args.sa = sa;
  68         args.rt = rt;
  69
  70         return tcp4_segment(m, ip_tso_output_callback, &args);
  71 }
  72
  73 /*
  74  * tcp4_segment: handle M_CSUM_TSOv4 by software.
  75  *
  76  * => always consume m.
  77  * => call output_func with output_arg for each segments.
  78  */
  79
  80 int
  81 tcp4_segment(struct mbuf *m, int (*output_func)(void *, struct mbuf *),
  82     void *output_arg)
  83 {
  84         int mss;
  85         int iphlen;
  86         int thlen;
  87         int hlen;
  88         int len;
  89         struct ip *iph;
  90         struct tcphdr *th;
  91         uint16_t ipid;
  92         uint32_t tcpseq;
  93         struct mbuf *hdr = NULL;
  94         struct mbuf *t;
  95         int error = 0;
  96
  97         KASSERT((m->m_flags & M_PKTHDR) != 0);
  98         KASSERT((m->m_pkthdr.csum_flags & M_CSUM_TSOv4) != 0);
  99
 100         m->m_pkthdr.csum_flags = 0;
 101
 102         len = m->m_pkthdr.len;
 103         KASSERT(len >= sizeof(*iph) + sizeof(*th));
 104
 105         if (m->m_len < sizeof(*iph)) {
 106                 m = m_pullup(m, sizeof(*iph));
 107                 if (m == NULL) {
 108                         error = ENOMEM;
 109                         goto quit;
 110                 }
 111         }
 112         iph = mtod(m, struct ip *);
 113         iphlen = iph->ip_hl * 4;
 114         KASSERT(iph->ip_v == IPVERSION);
 115         KASSERT(iphlen >= sizeof(*iph));
 116         KASSERT(iph->ip_p == IPPROTO_TCP);
 117         ipid = ntohs(iph->ip_id);
 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 ip *);
 168                 KASSERT(iph->ip_v == IPVERSION);
 169                 iph->ip_len = htons(n->m_pkthdr.len);
 170                 iph->ip_id = htons(ipid);
 171                 th = (void *)(mtod(n, char *) + iphlen);
 172                 th->th_seq = htonl(tcpseq);
 173                 iph->ip_sum = 0;
 174                 iph->ip_sum = in_cksum(n, iphlen);
 175                 th->th_sum = 0;
 176                 th->th_sum = in4_cksum(n, IPPROTO_TCP, iphlen, thlen + mss);
 177
 178                 error = (*output_func)(output_arg, n);
 179                 if (error) {
 180                         goto quit;
 181                 }
 182
 183                 tcpseq += mss;
 184                 ipid++;
 185                 len -= mss;
 186         }
 187
 188 quit:
 189         if (hdr != NULL) {
 190                 m_freem(hdr);
 191         }
 192         if (m != NULL) {
 193                 m_freem(m);
 194         }
 195
 196         return error;
 197 }