1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1990 The Regents of the University of California.
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 * 3. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 *
31 * from tahoe: in_cksum.c 1.2 86/01/05
32 * from: @(#)in_cksum.c 1.3 (Berkeley) 1/19/91
33 * from: Id: in_cksum.c,v 1.8 1995/12/03 18:35:19 bde Exp
34 * $FreeBSD: releng/12.0/sys/i386/include/in_cksum.h 326023 2017-11-20 19:43:44Z pfg $
35 */
36
37 #ifndef _MACHINE_IN_CKSUM_H_
38 #define _MACHINE_IN_CKSUM_H_ 1
39
40 #ifndef _SYS_CDEFS_H_
41 #error this file needs sys/cdefs.h as a prerequisite
42 #endif
43
44 /*
45 * MP safe (alfred)
46 */
47
48 #include <sys/cdefs.h>
49
50 #define in_cksum(m, len) in_cksum_skip(m, len, 0)
51
52 /*
53 * It it useful to have an Internet checksum routine which is inlineable
54 * and optimized specifically for the task of computing IP header checksums
55 * in the normal case (where there are no options and the header length is
56 * therefore always exactly five 32-bit words.
57 */
58 #if defined(__GNUCLIKE_ASM) && !defined(__INTEL_COMPILER)
59 #if defined(IPVERSION) && (IPVERSION == 4)
60 static __inline u_int
61 in_cksum_hdr(const struct ip *ip)
62 {
63 u_int sum = 0;
64
65 __asm(
66 "addl %1, %0\n"
67 "adcl %2, %0\n"
68 "adcl %3, %0\n"
69 "adcl %4, %0\n"
70 "adcl %5, %0\n"
71 "adcl $0, %0"
72 : "+r" (sum)
73 : "g" (((const u_int32_t *)ip)[0]),
74 "g" (((const u_int32_t *)ip)[1]),
75 "g" (((const u_int32_t *)ip)[2]),
76 "g" (((const u_int32_t *)ip)[3]),
77 "g" (((const u_int32_t *)ip)[4])
78 : "cc"
79 );
80 sum = (sum & 0xffff) + (sum >> 16);
81 if (sum > 0xffff)
82 sum -= 0xffff;
83
84 return ~sum & 0xffff;
85 }
86
87 static __inline void
88 in_cksum_update(struct ip *ip)
89 {
90 int __tmpsum;
91 __tmpsum = (int)ntohs(ip->ip_sum) + 256;
92 ip->ip_sum = htons(__tmpsum + (__tmpsum >> 16));
93 }
94 #endif
95
96 static __inline u_short
97 in_addword(u_short sum, u_short b)
98 {
99 __asm(
100 "addw %1, %0\n"
101 "adcw $0, %0"
102 : "+r" (sum)
103 : "g" (b)
104 : "cc"
105 );
106 return (sum);
107 }
108
109 static __inline u_short
110 in_pseudo(u_int sum, u_int b, u_int c)
111 {
112 __asm(
113 "addl %1, %0\n"
114 "adcl %2, %0\n"
115 "adcl $0, %0"
116 : "+r" (sum)
117 : "g" (b),
118 "g" (c)
119 : "cc"
120 );
121 sum = (sum & 0xffff) + (sum >> 16);
122 if (sum > 0xffff)
123 sum -= 0xffff;
124 return (sum);
125 }
126
127 #else
128 #if defined(IPVERSION) && (IPVERSION == 4)
129 #define in_cksum_update(ip) \
130 do { \
131 int __tmpsum; \
132 __tmpsum = (int)ntohs(ip->ip_sum) + 256; \
133 ip->ip_sum = htons(__tmpsum + (__tmpsum >> 16)); \
134 } while(0)
135
136 #endif
137 #endif
138
139 #ifdef _KERNEL
140 #if !defined(__GNUCLIKE_ASM) || defined(__INTEL_COMPILER)
141 #if defined(IPVERSION) && (IPVERSION == 4)
142 u_int in_cksum_hdr(const struct ip *ip);
143 #endif
144 u_short in_addword(u_short sum, u_short b);
145 u_short in_pseudo(u_int sum, u_int b, u_int c);
146 #endif
147 u_short in_cksum_skip(struct mbuf *m, int len, int skip);
148 #endif /* _KERNEL */
149
150 #endif /* _MACHINE_IN_CKSUM_H_ */
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