1 /*-
2 * Copyright (c) 1990 The Regents of the University of California.
3 * 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 * 4. 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 * from tahoe: in_cksum.c 1.2 86/01/05
30 * from: @(#)in_cksum.c 1.3 (Berkeley) 1/19/91
31 * from: Id: in_cksum.c,v 1.8 1995/12/03 18:35:19 bde Exp
32 * $FreeBSD$
33 */
34
35 #ifndef _MACHINE_IN_CKSUM_H_
36 #define _MACHINE_IN_CKSUM_H_ 1
37
38 #ifndef _SYS_CDEFS_H_
39 #error this file needs sys/cdefs.h as a prerequisite
40 #endif
41
42 /*
43 * MP safe (alfred)
44 */
45
46 #include <sys/cdefs.h>
47
48 #define in_cksum(m, len) in_cksum_skip(m, len, 0)
49
50 /*
51 * It it useful to have an Internet checksum routine which is inlineable
52 * and optimized specifically for the task of computing IP header checksums
53 * in the normal case (where there are no options and the header length is
54 * therefore always exactly five 32-bit words.
55 */
56 #if defined(__GNUCLIKE_ASM) && !defined(__INTEL_COMPILER)
57 static __inline u_int
58 in_cksum_hdr(const struct ip *ip)
59 {
60 register u_int sum = 0;
61
62 __asm __volatile (
63 "addl %1, %0\n"
64 "adcl %2, %0\n"
65 "adcl %3, %0\n"
66 "adcl %4, %0\n"
67 "adcl %5, %0\n"
68 "adcl $0, %0"
69 : "+r" (sum)
70 : "g" (((const u_int32_t *)ip)[0]),
71 "g" (((const u_int32_t *)ip)[1]),
72 "g" (((const u_int32_t *)ip)[2]),
73 "g" (((const u_int32_t *)ip)[3]),
74 "g" (((const u_int32_t *)ip)[4])
75 );
76 sum = (sum & 0xffff) + (sum >> 16);
77 if (sum > 0xffff)
78 sum -= 0xffff;
79
80 return ~sum & 0xffff;
81 }
82
83 static __inline void
84 in_cksum_update(struct ip *ip)
85 {
86 int __tmpsum;
87 __tmpsum = (int)ntohs(ip->ip_sum) + 256;
88 ip->ip_sum = htons(__tmpsum + (__tmpsum >> 16));
89 }
90
91 static __inline u_short
92 in_addword(u_short sum, u_short b)
93 {
94 /* __volatile is necessary because the condition codes are used. */
95 __asm __volatile (
96 "addw %1, %0\n"
97 "adcw $0, %0"
98 : "+r" (sum)
99 : "r" (b)
100 );
101 return (sum);
102 }
103
104 static __inline u_short
105 in_pseudo(u_int sum, u_int b, u_int c)
106 {
107 /* __volatile is necessary because the condition codes are used. */
108 __asm __volatile (
109 "addl %1, %0\n"
110 "adcl %2, %0\n"
111 "adcl $0, %0"
112 : "+r" (sum)
113 : "g" (b),
114 "g" (c)
115 );
116 sum = (sum & 0xffff) + (sum >> 16);
117 if (sum > 0xffff)
118 sum -= 0xffff;
119 return (sum);
120 }
121
122 #else
123 #define in_cksum_update(ip) \
124 do { \
125 int __tmpsum; \
126 __tmpsum = (int)ntohs(ip->ip_sum) + 256; \
127 ip->ip_sum = htons(__tmpsum + (__tmpsum >> 16)); \
128 } while(0)
129
130 #endif
131
132 #ifdef _KERNEL
133 #if !defined(__GNUCLIKE_ASM) || defined(__INTEL_COMPILER)
134 u_int in_cksum_hdr(const struct ip *ip);
135 u_short in_addword(u_short sum, u_short b);
136 u_short in_pseudo(u_int sum, u_int b, u_int c);
137 #endif
138 u_short in_cksum_skip(struct mbuf *m, int len, int skip);
139 #endif /* _KERNEL */
140
141 #endif /* _MACHINE_IN_CKSUM_H_ */
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