in_offload.c revision 1.11
1 /* $NetBSD: in_offload.c,v 1.11 2018/07/11 06:25:05 maxv 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 1.11 2018/07/11 06:25:05 maxv 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/ip_var.h> 41 #include <netinet/tcp.h> 42 #include <netinet/in_offload.h> 43 44 /* 45 * Handle M_CSUM_TSOv4 in software. Split the TCP payload in chunks of 46 * size MSS, and send them. 47 */ 48 static int 49 tcp4_segment(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *sa, 50 struct rtentry *rt) 51 { 52 int mss; 53 int iphlen, thlen; 54 int hlen, len; 55 struct ip *ip; 56 struct tcphdr *th; 57 uint16_t ipid; 58 uint32_t tcpseq; 59 struct mbuf *hdr = NULL; 60 struct mbuf *t; 61 int error = 0; 62 63 KASSERT((m->m_flags & M_PKTHDR) != 0); 64 KASSERT((m->m_pkthdr.csum_flags & M_CSUM_TSOv4) != 0); 65 66 m->m_pkthdr.csum_flags = 0; 67 68 len = m->m_pkthdr.len; 69 KASSERT(len >= sizeof(*ip) + sizeof(*th)); 70 71 if (m->m_len < sizeof(*ip)) { 72 m = m_pullup(m, sizeof(*ip)); 73 if (m == NULL) { 74 error = ENOMEM; 75 goto quit; 76 } 77 } 78 ip = mtod(m, struct ip *); 79 iphlen = ip->ip_hl * 4; 80 KASSERT(ip->ip_v == IPVERSION); 81 KASSERT(iphlen >= sizeof(*ip)); 82 KASSERT(ip->ip_p == IPPROTO_TCP); 83 ipid = ntohs(ip->ip_id); 84 85 hlen = iphlen + sizeof(*th); 86 if (m->m_len < hlen) { 87 m = m_pullup(m, hlen); 88 if (m == NULL) { 89 error = ENOMEM; 90 goto quit; 91 } 92 } 93 th = (void *)(mtod(m, char *) + iphlen); 94 tcpseq = ntohl(th->th_seq); 95 thlen = th->th_off * 4; 96 hlen = iphlen + thlen; 97 98 mss = m->m_pkthdr.segsz; 99 KASSERT(mss != 0); 100 KASSERT(len > hlen); 101 102 t = m_split(m, hlen, M_NOWAIT); 103 if (t == NULL) { 104 error = ENOMEM; 105 goto quit; 106 } 107 hdr = m; 108 m = t; 109 len -= hlen; 110 KASSERT(len % mss == 0); 111 while (len > 0) { 112 struct mbuf *n; 113 114 n = m_dup(hdr, 0, hlen, M_NOWAIT); 115 if (n == NULL) { 116 error = ENOMEM; 117 goto quit; 118 } 119 KASSERT(n->m_len == hlen); /* XXX */ 120 121 t = m_split(m, mss, M_NOWAIT); 122 if (t == NULL) { 123 m_freem(n); 124 error = ENOMEM; 125 goto quit; 126 } 127 m_cat(n, m); 128 m = t; 129 130 KASSERT(n->m_len >= hlen); /* XXX */ 131 132 n->m_pkthdr.len = hlen + mss; 133 ip = mtod(n, struct ip *); 134 KASSERT(ip->ip_v == IPVERSION); 135 ip->ip_len = htons(n->m_pkthdr.len); 136 ip->ip_id = htons(ipid); 137 th = (void *)(mtod(n, char *) + iphlen); 138 th->th_seq = htonl(tcpseq); 139 ip->ip_sum = 0; 140 ip->ip_sum = in_cksum(n, iphlen); 141 th->th_sum = 0; 142 th->th_sum = in4_cksum(n, IPPROTO_TCP, iphlen, thlen + mss); 143 144 error = ip_if_output(ifp, n, sa, rt); 145 if (error) { 146 goto quit; 147 } 148 149 tcpseq += mss; 150 ipid++; 151 len -= mss; 152 } 153 154 quit: 155 if (hdr != NULL) { 156 m_freem(hdr); 157 } 158 if (m != NULL) { 159 m_freem(m); 160 } 161 162 return error; 163 } 164 165 int 166 ip_tso_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *sa, 167 struct rtentry *rt) 168 { 169 return tcp4_segment(ifp, m, sa, rt); 170 } 171 172 /* 173 * Compute now in software the IP and TCP/UDP checksums. Cancel the 174 * hardware offloading. 175 */ 176 void 177 in_undefer_cksum(struct mbuf *m, size_t hdrlen, int csum_flags) 178 { 179 const size_t iphdrlen = M_CSUM_DATA_IPv4_IPHL(m->m_pkthdr.csum_data); 180 uint16_t csum; 181 uint16_t ip_len; 182 uint16_t *csump; 183 184 KASSERT(m->m_flags & M_PKTHDR); 185 KASSERT((m->m_pkthdr.csum_flags & csum_flags) == csum_flags); 186 187 if (__predict_true(hdrlen + sizeof(struct ip) <= m->m_len)) { 188 struct ip *ip = (struct ip *)(mtod(m, uint8_t *) + hdrlen); 189 190 ip_len = ip->ip_len; 191 csump = &ip->ip_sum; 192 } else { 193 const size_t ip_len_offset = 194 hdrlen + offsetof(struct ip, ip_len); 195 196 m_copydata(m, ip_len_offset, sizeof(ip_len), &ip_len); 197 csump = NULL; 198 } 199 ip_len = ntohs(ip_len); 200 201 if (csum_flags & M_CSUM_IPv4) { 202 csum = in4_cksum(m, 0, hdrlen, iphdrlen); 203 if (csump != NULL) { 204 *csump = csum; 205 } else { 206 const size_t offset = hdrlen + 207 offsetof(struct ip, ip_sum); 208 209 m_copyback(m, offset, sizeof(uint16_t), &csum); 210 } 211 } 212 213 if (csum_flags & (M_CSUM_UDPv4|M_CSUM_TCPv4)) { 214 size_t l4offset = hdrlen + iphdrlen; 215 216 csum = in4_cksum(m, 0, l4offset, ip_len - l4offset - hdrlen); 217 if (csum == 0 && (csum_flags & M_CSUM_UDPv4) != 0) 218 csum = 0xffff; 219 220 l4offset += M_CSUM_DATA_IPv4_OFFSET(m->m_pkthdr.csum_data); 221 222 if (__predict_true(l4offset + sizeof(uint16_t) <= m->m_len)) { 223 *(uint16_t *)(mtod(m, char *) + l4offset) = csum; 224 } else { 225 m_copyback(m, l4offset, sizeof(csum), (void *)&csum); 226 } 227 } 228 229 m->m_pkthdr.csum_flags ^= csum_flags; 230 } 231 232 /* 233 * Compute now in software the TCP/UDP checksum. Cancel the hardware 234 * offloading. 235 */ 236 void 237 in_undefer_cksum_tcpudp(struct mbuf *m) 238 { 239 struct ip *ip; 240 uint16_t csum, offset; 241 242 KASSERT((m->m_flags & M_PKTHDR) != 0); 243 KASSERT((m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) != 0); 244 KASSERT((m->m_pkthdr.csum_flags & (M_CSUM_TCPv6|M_CSUM_UDPv6)) == 0); 245 246 ip = mtod(m, struct ip *); 247 offset = ip->ip_hl << 2; 248 249 csum = in4_cksum(m, 0, offset, ntohs(ip->ip_len) - offset); 250 if (csum == 0 && (m->m_pkthdr.csum_flags & M_CSUM_UDPv4) != 0) 251 csum = 0xffff; 252 253 offset += M_CSUM_DATA_IPv4_OFFSET(m->m_pkthdr.csum_data); 254 255 if ((offset + sizeof(uint16_t)) <= m->m_len) { 256 *(uint16_t *)(mtod(m, char *) + offset) = csum; 257 } else { 258 m_copyback(m, offset, sizeof(csum), (void *)&csum); 259 } 260 } 261
Indexes created Fri Sep 26 08:10:20 GMT 2025