| 1 | /* $NetBSD: xennet_checksum.c,v 1.3 2007/11/22 16:17:10 bouyer 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: xennet_checksum.c,v 1.3 2007/11/22 16:17:10 bouyer Exp $" ); |
| 31 | |
| 32 | #include <sys/types.h> |
| 33 | #include <sys/param.h> |
| 34 | |
| 35 | #include <net/if.h> |
| 36 | #include <net/if_dl.h> |
| 37 | #include <net/if_ether.h> |
| 38 | #include <net/if_vlanvar.h> |
| 39 | |
| 40 | #include <netinet/in.h> |
| 41 | #include <netinet/in_systm.h> |
| 42 | #include <netinet/ip.h> |
| 43 | #include <netinet/tcp.h> |
| 44 | #include <netinet/udp.h> |
| 45 | |
| 46 | #include <xen/xennet_checksum.h> |
| 47 | |
| 48 | static const void *m_extract(struct mbuf *, int, int, void *); |
| 49 | static void *m_extract_write(struct mbuf *, int, int, void *); |
| 50 | |
| 51 | static void *m_extract1(struct mbuf *, int, int, void *, int); |
| 52 | #define 1 |
| 53 | |
| 54 | static void * |
| 55 | (struct mbuf *m, int off, int len, void *buf, int flags) |
| 56 | { |
| 57 | void *result; |
| 58 | |
| 59 | KASSERT((m->m_flags & M_PKTHDR) != 0); |
| 60 | |
| 61 | if (m->m_pkthdr.len < off + len) { |
| 62 | result = NULL; |
| 63 | } else if (m->m_len >= off + len && |
| 64 | ((flags & MBUF_EXTRACT_WRITE) != 0 || !M_READONLY(m))) { |
| 65 | result = mtod(m, char *) + off; |
| 66 | } else { |
| 67 | m_copydata(m, off, len, buf); |
| 68 | result = buf; |
| 69 | } |
| 70 | |
| 71 | return result; |
| 72 | } |
| 73 | |
| 74 | static const void * |
| 75 | (struct mbuf *m, int off, int len, void *buf) |
| 76 | { |
| 77 | |
| 78 | return m_extract1(m, off, len, buf, 0); |
| 79 | } |
| 80 | |
| 81 | static void * |
| 82 | (struct mbuf *m, int off, int len, void *buf) |
| 83 | { |
| 84 | |
| 85 | return m_extract1(m, off, len, buf, MBUF_EXTRACT_WRITE); |
| 86 | } |
| 87 | |
| 88 | /* |
| 89 | * xennet_checksum_fill: fill TCP/UDP checksum |
| 90 | */ |
| 91 | |
| 92 | int |
| 93 | xennet_checksum_fill(struct mbuf **mp) |
| 94 | { |
| 95 | struct mbuf *m = *mp; |
| 96 | struct ether_header eh_store; |
| 97 | const struct ether_header *eh; |
| 98 | struct ip iph_store; |
| 99 | const struct ip *iph; |
| 100 | int ehlen; |
| 101 | int iphlen; |
| 102 | int iplen; |
| 103 | uint16_t etype; |
| 104 | uint8_t nxt; |
| 105 | int error = 0; |
| 106 | |
| 107 | eh = m_extract(m, 0, sizeof(*eh), &eh_store); |
| 108 | if (eh == NULL) { |
| 109 | return EINVAL; |
| 110 | } |
| 111 | etype = eh->ether_type; |
| 112 | if (etype == htobe16(ETHERTYPE_VLAN)) { |
| 113 | ehlen = ETHER_HDR_LEN + ETHER_VLAN_ENCAP_LEN; |
| 114 | } else if (etype == htobe16(ETHERTYPE_IP)) { |
| 115 | ehlen = ETHER_HDR_LEN; |
| 116 | } else { |
| 117 | return EINVAL; |
| 118 | } |
| 119 | |
| 120 | iph = m_extract(m, ehlen, sizeof(*iph), &iph_store); |
| 121 | if (iph == NULL) { |
| 122 | return EINVAL; |
| 123 | } |
| 124 | nxt = iph->ip_p; |
| 125 | iphlen = iph->ip_hl * 4; |
| 126 | iplen = ntohs(iph->ip_len); |
| 127 | if (ehlen + iplen != m->m_pkthdr.len) { |
| 128 | return EINVAL; |
| 129 | } |
| 130 | if (nxt == IPPROTO_UDP) { |
| 131 | struct udphdr uh_store; |
| 132 | struct udphdr *uh; |
| 133 | int ulen; |
| 134 | |
| 135 | uh = m_extract_write(m, ehlen + iphlen, sizeof(*uh), &uh_store); |
| 136 | ulen = ntohs(uh->uh_ulen); |
| 137 | if (ehlen + iphlen + ulen > m->m_pkthdr.len) { |
| 138 | return EINVAL; |
| 139 | } |
| 140 | m->m_len -= ehlen; |
| 141 | m->m_data += ehlen; |
| 142 | uh->uh_sum = 0; |
| 143 | uh->uh_sum = in4_cksum(m, nxt, iphlen, iplen - iphlen); |
| 144 | m->m_len += ehlen; |
| 145 | m->m_data -= ehlen; |
| 146 | if (uh != &uh_store) { |
| 147 | m = m_copyback_cow(m, ehlen + iphlen, sizeof(*uh), uh, |
| 148 | M_DONTWAIT); |
| 149 | if (m == NULL) { |
| 150 | error = ENOMEM; |
| 151 | } |
| 152 | } |
| 153 | } else if (nxt == IPPROTO_TCP) { |
| 154 | struct tcphdr th_store; |
| 155 | struct tcphdr *th; |
| 156 | int thlen; |
| 157 | |
| 158 | th = m_extract_write(m, ehlen + iphlen, sizeof(*th), &th_store); |
| 159 | thlen = th->th_off * 4; |
| 160 | if (ehlen + iphlen + thlen > m->m_pkthdr.len) { |
| 161 | return EINVAL; |
| 162 | } |
| 163 | m->m_len -= ehlen; |
| 164 | m->m_data += ehlen; |
| 165 | th->th_sum = 0; |
| 166 | th->th_sum = in4_cksum(m, nxt, iphlen, iplen - iphlen); |
| 167 | m->m_len += ehlen; |
| 168 | m->m_data -= ehlen; |
| 169 | if (th != &th_store) { |
| 170 | m = m_copyback_cow(m, ehlen + iphlen, sizeof(*th), th, |
| 171 | M_DONTWAIT); |
| 172 | if (m == NULL) { |
| 173 | error = ENOMEM; |
| 174 | } |
| 175 | } |
| 176 | } else { |
| 177 | error = EINVAL; |
| 178 | } |
| 179 | |
| 180 | *mp = m; |
| 181 | return error; |
| 182 | } |
| 183 | |