1 /* $NetBSD: in6_offload.c,v 1.13 2024/07/05 04:31:54 rin 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 1.13 2024/07/05 04:31:54 rin 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/ip6_var.h> 43 #include <netinet6/nd6.h> 44 #include <netinet6/in6_offload.h> 45 46 /* 47 * Handle M_CSUM_TSOv6 in software. Split the TCP payload in chunks of 48 * size MSS, and return mbuf chain consists of them. 49 */ 50 struct mbuf * 51 tcp6_segment(struct mbuf *m, int off) 52 { 53 int mss; 54 int iphlen; 55 int thlen; 56 int hlen; 57 int len; 58 struct ip6_hdr *iph; 59 struct tcphdr *th; 60 uint32_t tcpseq; 61 uint16_t phsum; 62 struct mbuf *hdr = NULL; 63 struct mbuf *m0 = NULL; 64 struct mbuf *prev = NULL; 65 struct mbuf *n, *t; 66 int nsegs; 67 68 KASSERT((m->m_flags & M_PKTHDR) != 0); 69 KASSERT((m->m_pkthdr.csum_flags & M_CSUM_TSOv6) != 0); 70 71 m->m_pkthdr.csum_flags = 0; 72 73 len = m->m_pkthdr.len; 74 KASSERT(len >= off + sizeof(*iph) + sizeof(*th)); 75 76 hlen = off + sizeof(*iph); 77 if (m->m_len < hlen) { 78 m = m_pullup(m, hlen); 79 if (m == NULL) 80 goto quit; 81 } 82 iph = (void *)(mtod(m, char *) + off); 83 iphlen = sizeof(*iph); 84 KASSERT((iph->ip6_vfc & IPV6_VERSION_MASK) == IPV6_VERSION); 85 KASSERT(iph->ip6_nxt == IPPROTO_TCP); 86 87 hlen = off + iphlen + sizeof(*th); 88 if (m->m_len < hlen) { 89 m = m_pullup(m, hlen); 90 if (m == NULL) 91 goto quit; 92 } 93 th = (void *)(mtod(m, char *) + off + iphlen); 94 tcpseq = ntohl(th->th_seq); 95 thlen = th->th_off * 4; 96 hlen = off + 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 goto quit; 105 hdr = m; 106 m = t; 107 108 len -= hlen; 109 KASSERT(len % mss == 0); 110 111 iph = (void *)(mtod(hdr, char *) + off); 112 iph->ip6_plen = htons(thlen + mss); 113 phsum = in6_cksum_phdr(&iph->ip6_src, &iph->ip6_dst, htonl(thlen + mss), 114 htonl(IPPROTO_TCP)); 115 116 for (nsegs = len / mss; nsegs > 0; nsegs--) { 117 if (nsegs > 1) { 118 n = m_dup(hdr, 0, hlen, M_NOWAIT); 119 if (n == NULL) 120 goto quit; 121 } else 122 n = hdr; 123 KASSERT(n->m_len == hlen); /* XXX */ 124 125 if (nsegs > 1) { 126 t = m_split(m, mss, M_NOWAIT); 127 if (t == NULL) { 128 m_freem(n); 129 goto quit; 130 } 131 } else 132 t = m; 133 m_cat(n, m); 134 m = t; 135 136 KASSERT(n->m_len >= hlen); /* XXX */ 137 138 if (m0 == NULL) 139 m0 = n; 140 141 if (prev != NULL) 142 prev->m_nextpkt = n; 143 144 n->m_pkthdr.len = hlen + mss; 145 n->m_nextpkt = NULL; /* XXX */ 146 147 th = (void *)(mtod(n, char *) + off + iphlen); 148 th->th_seq = htonl(tcpseq); 149 th->th_sum = phsum; 150 th->th_sum = in6_cksum(n, 0, off + iphlen, thlen + mss); 151 152 tcpseq += mss; 153 prev = n; 154 } 155 return m0; 156 157 quit: 158 m_freem(hdr); 159 m_freem(m); 160 for (m = m0; m != NULL; m = n) { 161 n = m->m_nextpkt; 162 m_freem(m); 163 } 164 165 return NULL; 166 } 167 168 int 169 ip6_tso_output(struct ifnet *ifp, struct ifnet *origifp, struct mbuf *m, 170 const struct sockaddr_in6 *dst, struct rtentry *rt) 171 { 172 struct mbuf *n; 173 int error = 0; 174 175 m = tcp6_segment(m, 0); 176 if (m == NULL) 177 return ENOMEM; 178 do { 179 n = m->m_nextpkt; 180 if (error == 0) 181 error = ip6_if_output(ifp, origifp, m, dst, rt); 182 else 183 m_freem(m); 184 m = n; 185 } while (m != NULL); 186 return error; 187 } 188 189 /* 190 * Compute now in software the IP and TCP/UDP checksums. Cancel the 191 * hardware offloading. 192 */ 193 void 194 in6_undefer_cksum(struct mbuf *m, size_t hdrlen, int csum_flags) 195 { 196 const size_t ip6_plen_offset = 197 hdrlen + offsetof(struct ip6_hdr, ip6_plen); 198 size_t l4hdroff; 199 size_t l4offset; 200 uint16_t plen; 201 uint16_t csum; 202 203 KASSERT(m->m_flags & M_PKTHDR); 204 KASSERT((m->m_pkthdr.csum_flags & csum_flags) == csum_flags); 205 KASSERT(csum_flags == M_CSUM_UDPv6 || csum_flags == M_CSUM_TCPv6); 206 207 if (__predict_true(hdrlen + sizeof(struct ip6_hdr) <= m->m_len)) { 208 plen = *(uint16_t *)(mtod(m, char *) + ip6_plen_offset); 209 } else { 210 m_copydata(m, ip6_plen_offset, sizeof(plen), &plen); 211 } 212 plen = ntohs(plen); 213 214 l4hdroff = M_CSUM_DATA_IPv6_IPHL(m->m_pkthdr.csum_data); 215 l4offset = hdrlen + l4hdroff; 216 csum = in6_cksum(m, 0, l4offset, 217 plen - (l4hdroff - sizeof(struct ip6_hdr))); 218 219 if (csum == 0 && (csum_flags & M_CSUM_UDPv6) != 0) 220 csum = 0xffff; 221 222 l4offset += M_CSUM_DATA_IPv6_OFFSET(m->m_pkthdr.csum_data); 223 224 if (__predict_true((l4offset + sizeof(uint16_t)) <= m->m_len)) { 225 *(uint16_t *)(mtod(m, char *) + l4offset) = csum; 226 } else { 227 m_copyback(m, l4offset, sizeof(csum), (void *) &csum); 228 } 229 230 m->m_pkthdr.csum_flags ^= csum_flags; 231 } 232 233 /* 234 * Compute now in software the TCP/UDP checksum. Cancel the hardware 235 * offloading. 236 */ 237 void 238 in6_undefer_cksum_tcpudp(struct mbuf *m) 239 { 240 uint16_t csum, offset; 241 242 KASSERT((m->m_pkthdr.csum_flags & (M_CSUM_UDPv6|M_CSUM_TCPv6)) != 0); 243 KASSERT((~m->m_pkthdr.csum_flags & (M_CSUM_UDPv6|M_CSUM_TCPv6)) != 0); 244 KASSERT((m->m_pkthdr.csum_flags 245 & (M_CSUM_UDPv4|M_CSUM_TCPv4|M_CSUM_TSOv4)) == 0); 246 247 offset = M_CSUM_DATA_IPv6_IPHL(m->m_pkthdr.csum_data); 248 csum = in6_cksum(m, 0, offset, m->m_pkthdr.len - offset); 249 if (csum == 0 && (m->m_pkthdr.csum_flags & M_CSUM_UDPv6) != 0) { 250 csum = 0xffff; 251 } 252 253 offset += M_CSUM_DATA_IPv6_OFFSET(m->m_pkthdr.csum_data); 254 if ((offset + sizeof(csum)) > m->m_len) { 255 m_copyback(m, offset, sizeof(csum), &csum); 256 } else { 257 *(uint16_t *)(mtod(m, char *) + offset) = csum; 258 } 259 } 260
Indexes created Sat Sep 20 22:09:52 GMT 2025