1 /* $NetBSD: in_offload.c,v 1.5 2011/04/25 22:11:31 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 1.5 2011/04/25 22:11:31 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 int error; 57 58 KERNEL_LOCK(1, NULL); 59 error = (*ifp->if_output)(ifp, m, args->sa, args->rt); 60 KERNEL_UNLOCK_ONE(NULL); 61 return error; 62 } 63 64 int 65 ip_tso_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *sa, 66 struct rtentry *rt) 67 { 68 struct ip_tso_output_args args; 69 70 args.ifp = ifp; 71 args.sa = sa; 72 args.rt = rt; 73 74 return tcp4_segment(m, ip_tso_output_callback, &args); 75 } 76 77 /* 78 * tcp4_segment: handle M_CSUM_TSOv4 by software. 79 * 80 * => always consume m. 81 * => call output_func with output_arg for each segments. 82 */ 83 84 int 85 tcp4_segment(struct mbuf *m, int (*output_func)(void *, struct mbuf *), 86 void *output_arg) 87 { 88 int mss; 89 int iphlen; 90 int thlen; 91 int hlen; 92 int len; 93 struct ip *iph; 94 struct tcphdr *th; 95 uint16_t ipid; 96 uint32_t tcpseq; 97 struct mbuf *hdr = NULL; 98 struct mbuf *t; 99 int error = 0; 100 101 KASSERT((m->m_flags & M_PKTHDR) != 0); 102 KASSERT((m->m_pkthdr.csum_flags & M_CSUM_TSOv4) != 0); 103 104 m->m_pkthdr.csum_flags = 0; 105 106 len = m->m_pkthdr.len; 107 KASSERT(len >= sizeof(*iph) + sizeof(*th)); 108 109 if (m->m_len < sizeof(*iph)) { 110 m = m_pullup(m, sizeof(*iph)); 111 if (m == NULL) { 112 error = ENOMEM; 113 goto quit; 114 } 115 } 116 iph = mtod(m, struct ip *); 117 iphlen = iph->ip_hl * 4; 118 KASSERT(iph->ip_v == IPVERSION); 119 KASSERT(iphlen >= sizeof(*iph)); 120 KASSERT(iph->ip_p == IPPROTO_TCP); 121 ipid = ntohs(iph->ip_id); 122 123 hlen = iphlen + sizeof(*th); 124 if (m->m_len < hlen) { 125 m = m_pullup(m, hlen); 126 if (m == NULL) { 127 error = ENOMEM; 128 goto quit; 129 } 130 } 131 th = (void *)(mtod(m, char *) + iphlen); 132 tcpseq = ntohl(th->th_seq); 133 thlen = th->th_off * 4; 134 hlen = iphlen + thlen; 135 136 mss = m->m_pkthdr.segsz; 137 KASSERT(mss != 0); 138 KASSERT(len > hlen); 139 140 t = m_split(m, hlen, M_NOWAIT); 141 if (t == NULL) { 142 error = ENOMEM; 143 goto quit; 144 } 145 hdr = m; 146 m = t; 147 len -= hlen; 148 KASSERT(len % mss == 0); 149 while (len > 0) { 150 struct mbuf *n; 151 152 n = m_dup(hdr, 0, hlen, M_NOWAIT); 153 if (n == NULL) { 154 error = ENOMEM; 155 goto quit; 156 } 157 KASSERT(n->m_len == hlen); /* XXX */ 158 159 t = m_split(m, mss, M_NOWAIT); 160 if (t == NULL) { 161 m_freem(n); 162 error = ENOMEM; 163 goto quit; 164 } 165 m_cat(n, m); 166 m = t; 167 168 KASSERT(n->m_len >= hlen); /* XXX */ 169 170 n->m_pkthdr.len = hlen + mss; 171 iph = mtod(n, struct ip *); 172 KASSERT(iph->ip_v == IPVERSION); 173 iph->ip_len = htons(n->m_pkthdr.len); 174 iph->ip_id = htons(ipid); 175 th = (void *)(mtod(n, char *) + iphlen); 176 th->th_seq = htonl(tcpseq); 177 iph->ip_sum = 0; 178 iph->ip_sum = in_cksum(n, iphlen); 179 th->th_sum = 0; 180 th->th_sum = in4_cksum(n, IPPROTO_TCP, iphlen, thlen + mss); 181 182 error = (*output_func)(output_arg, n); 183 if (error) { 184 goto quit; 185 } 186 187 tcpseq += mss; 188 ipid++; 189 len -= mss; 190 } 191 192 quit: 193 if (hdr != NULL) { 194 m_freem(hdr); 195 } 196 if (m != NULL) { 197 m_freem(m); 198 } 199 200 return error; 201 } 202 203 void 204 ip_undefer_csum(struct mbuf *m, size_t hdrlen, int csum_flags) 205 { 206 const size_t iphdrlen = M_CSUM_DATA_IPv4_IPHL(m->m_pkthdr.csum_data); 207 uint16_t csum; 208 uint16_t ip_len; 209 uint16_t *csump; 210 211 KASSERT(m->m_flags & M_PKTHDR); 212 KASSERT((m->m_pkthdr.csum_flags & csum_flags) == csum_flags); 213 214 if (__predict_true(hdrlen + sizeof(struct ip) <= m->m_len)) { 215 struct ip *ip = (struct ip *)(mtod(m, uint8_t *) + hdrlen); 216 217 ip_len = ip->ip_len; 218 csump = &ip->ip_sum; 219 } else { 220 const size_t ip_len_offset = 221 hdrlen + offsetof(struct ip, ip_len); 222 223 m_copydata(m, ip_len_offset, sizeof(ip_len), &ip_len); 224 csump = NULL; 225 } 226 ip_len = ntohs(ip_len); 227 228 if (csum_flags & M_CSUM_IPv4) { 229 csum = in4_cksum(m, 0, hdrlen, iphdrlen); 230 if (csump != NULL) { 231 *csump = csum; 232 } else { 233 const size_t offset = hdrlen + 234 offsetof(struct ip, ip_sum); 235 236 m_copyback(m, offset, sizeof(uint16_t), &csum); 237 } 238 } 239 240 if (csum_flags & (M_CSUM_UDPv4|M_CSUM_TCPv4)) { 241 size_t l4offset = hdrlen + iphdrlen; 242 243 csum = in4_cksum(m, 0, l4offset, ip_len - l4offset - hdrlen); 244 if (csum == 0 && (csum_flags & M_CSUM_UDPv4) != 0) 245 csum = 0xffff; 246 247 l4offset += M_CSUM_DATA_IPv4_OFFSET(m->m_pkthdr.csum_data); 248 249 if (__predict_true(l4offset + sizeof(uint16_t) <= m->m_len)) { 250 *(uint16_t *)(mtod(m, char *) + l4offset) = csum; 251 } else { 252 m_copyback(m, l4offset, sizeof(csum), (void *) &csum); 253 } 254 } 255 256 m->m_pkthdr.csum_flags ^= csum_flags; 257 } 258