1 /* $NetBSD: in6_offload.c,v 1.5 2010/12/11 22:37:47 matt Exp $ */ 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 1.5 2010/12/11 22:37:47 matt 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 } 194 195 void 196 ip6_undefer_csum(struct mbuf *m, size_t hdrlen, int csum_flags) 197 { 198 KASSERT(m->m_flags & M_PKTHDR); 199 KASSERT((m->m_pkthdr.csum_flags & csum_flags) == csum_flags); 200 KASSERT(csum_flags == M_CSUM_UDPv6 || csum_flags == M_CSUM_TCPv6); 201 202 const size_t ip6_plen_offset = hdrlen + offsetof(struct ip6_hdr, ip6_plen); 203 uint16_t plen; 204 205 if (__predict_true(hdrlen + sizeof(struct ip6_hdr) <= m->m_len)) { 206 plen = *(uint16_t *)(mtod(m, char *) + ip6_plen_offset); 207 } else { 208 m_copydata(m, ip6_plen_offset, sizeof(plen), &plen); 209 } 210 211 const size_t l4hdroff = M_CSUM_DATA_IPv6_HL(m->m_pkthdr.csum_data); 212 size_t l4offset = hdrlen + l4hdroff; 213 uint16_t csum = in6_cksum(m, 0, l4offset, plen - l4hdroff); 214 215 if (csum == 0 && (csum_flags & M_CSUM_UDPv6) != 0) 216 csum = 0xffff; 217 218 l4offset += M_CSUM_DATA_IPv6_OFFSET(m->m_pkthdr.csum_data); 219 220 if (__predict_true((l4offset + sizeof(uint16_t)) <= m->m_len)) { 221 *(uint16_t *)(mtod(m, char *) + l4offset) = csum; 222 } else { 223 m_copyback(m, l4offset, sizeof(csum), (void *) &csum); 224 } 225 226 m->m_pkthdr.csum_flags ^= csum_flags; 227 } 228