tests: virtio-9p: add version operation test
[qemu.git] / slirp / cksum.c
1 /*
2 * Copyright (c) 1988, 1992, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 * @(#)in_cksum.c 8.1 (Berkeley) 6/10/93
30 * in_cksum.c,v 1.2 1994/08/02 07:48:16 davidg Exp
31 */
32
33 #include "qemu/osdep.h"
34 #include "slirp.h"
35
36 /*
37 * Checksum routine for Internet Protocol family headers (Portable Version).
38 *
39 * This routine is very heavily used in the network
40 * code and should be modified for each CPU to be as fast as possible.
41 *
42 * XXX Since we will never span more than 1 mbuf, we can optimise this
43 */
44
45 #define ADDCARRY(x) (x > 65535 ? x -= 65535 : x)
46 #define REDUCE {l_util.l = sum; sum = l_util.s[0] + l_util.s[1]; \
47 (void)ADDCARRY(sum);}
48
49 int cksum(struct mbuf *m, int len)
50 {
51 register uint16_t *w;
52 register int sum = 0;
53 register int mlen = 0;
54 int byte_swapped = 0;
55
56 union {
57 uint8_t c[2];
58 uint16_t s;
59 } s_util;
60 union {
61 uint16_t s[2];
62 uint32_t l;
63 } l_util;
64
65 if (m->m_len == 0)
66 goto cont;
67 w = mtod(m, uint16_t *);
68
69 mlen = m->m_len;
70
71 if (len < mlen)
72 mlen = len;
73 #ifdef DEBUG
74 len -= mlen;
75 #endif
76 /*
77 * Force to even boundary.
78 */
79 if ((1 & (uintptr_t)w) && (mlen > 0)) {
80 REDUCE;
81 sum <<= 8;
82 s_util.c[0] = *(uint8_t *)w;
83 w = (uint16_t *)((int8_t *)w + 1);
84 mlen--;
85 byte_swapped = 1;
86 }
87 /*
88 * Unroll the loop to make overhead from
89 * branches &c small.
90 */
91 while ((mlen -= 32) >= 0) {
92 sum += w[0]; sum += w[1]; sum += w[2]; sum += w[3];
93 sum += w[4]; sum += w[5]; sum += w[6]; sum += w[7];
94 sum += w[8]; sum += w[9]; sum += w[10]; sum += w[11];
95 sum += w[12]; sum += w[13]; sum += w[14]; sum += w[15];
96 w += 16;
97 }
98 mlen += 32;
99 while ((mlen -= 8) >= 0) {
100 sum += w[0]; sum += w[1]; sum += w[2]; sum += w[3];
101 w += 4;
102 }
103 mlen += 8;
104 if (mlen == 0 && byte_swapped == 0)
105 goto cont;
106 REDUCE;
107 while ((mlen -= 2) >= 0) {
108 sum += *w++;
109 }
110
111 if (byte_swapped) {
112 REDUCE;
113 sum <<= 8;
114 if (mlen == -1) {
115 s_util.c[1] = *(uint8_t *)w;
116 sum += s_util.s;
117 mlen = 0;
118 } else
119
120 mlen = -1;
121 } else if (mlen == -1)
122 s_util.c[0] = *(uint8_t *)w;
123
124 cont:
125 #ifdef DEBUG
126 if (len) {
127 DEBUG_ERROR((dfd, "cksum: out of data\n"));
128 DEBUG_ERROR((dfd, " len = %d\n", len));
129 }
130 #endif
131 if (mlen == -1) {
132 /* The last mbuf has odd # of bytes. Follow the
133 standard (the odd byte may be shifted left by 8 bits
134 or not as determined by endian-ness of the machine) */
135 s_util.c[1] = 0;
136 sum += s_util.s;
137 }
138 REDUCE;
139 return (~sum & 0xffff);
140 }
141
142 int ip6_cksum(struct mbuf *m)
143 {
144 /* TODO: Optimize this by being able to pass the ip6_pseudohdr to cksum
145 * separately from the mbuf */
146 struct ip6 save_ip, *ip = mtod(m, struct ip6 *);
147 struct ip6_pseudohdr *ih = mtod(m, struct ip6_pseudohdr *);
148 int sum;
149
150 save_ip = *ip;
151
152 ih->ih_src = save_ip.ip_src;
153 ih->ih_dst = save_ip.ip_dst;
154 ih->ih_pl = htonl((uint32_t)ntohs(save_ip.ip_pl));
155 ih->ih_zero_hi = 0;
156 ih->ih_zero_lo = 0;
157 ih->ih_nh = save_ip.ip_nh;
158
159 sum = cksum(m, ((int)sizeof(struct ip6_pseudohdr))
160 + ntohl(ih->ih_pl));
161
162 *ip = save_ip;
163
164 return sum;
165 }