2 Copyright (C) Andrew Tridgell 1996
3 Copyright (C) Paul Mackerras 1996
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 2 of the License, or
8 (at your option) any later version.
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this program; if not, write to the Free Software
17 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
22 int csum_length=SUM_LENGTH;
26 int checksum_seed = 0;
29 a simple 32 bit checksum that can be upadted from either end
30 (inspired by Mark Adler's Adler-32 checksum)
32 uint32 get_checksum1(char *buf,int len)
38 for (i = 0; i < (len-4); i+=4) {
39 s2 += 4*(s1 + buf[i]) + 3*buf[i+1] + 2*buf[i+2] + buf[i+3];
40 s1 += (buf[i+0] + buf[i+1] + buf[i+2] + buf[i+3]);
42 for (; i < len; i++) {
43 s1 += buf[i]; s2 += s1;
45 return (s1 & 0xffff) + (s2 << 16);
49 static void sum_put(MDstruct *md,char *sum)
51 SIVAL(sum,0,md->buffer[0]);
52 if (csum_length <= 4) return;
53 SIVAL(sum,4,md->buffer[1]);
54 if (csum_length <= 8) return;
55 SIVAL(sum,8,md->buffer[2]);
56 if (csum_length <= 12) return;
57 SIVAL(sum,12,md->buffer[3]);
61 void get_checksum2(char *buf,int len,char *sum)
65 static char *buf1 = NULL;
70 buf1 = (char *)malloc(len+4);
72 if (!buf1) out_of_memory("get_checksum2");
79 SIVAL(buf1,len,checksum_seed);
83 for(i = 0; i + CSUM_CHUNK <= len; i += CSUM_CHUNK) {
84 MDupdate(&MD, buf1+i, CSUM_CHUNK*8);
87 MDupdate(&MD, buf1+i, (len-i)*8);
93 void file_checksum(char *fname,char *sum,off_t size)
97 struct map_struct *buf;
100 char tmpchunk[CSUM_CHUNK];
102 bzero(sum,csum_length);
104 fd = open(fname,O_RDONLY);
105 if (fd == -1) return;
107 buf = map_file(fd,size);
111 for(i = 0; i + CSUM_CHUNK <= len; i += CSUM_CHUNK) {
112 bcopy(map_ptr(buf,i,CSUM_CHUNK),tmpchunk,CSUM_CHUNK);
113 MDupdate(&MD, tmpchunk, CSUM_CHUNK*8);
117 bcopy(map_ptr(buf,i,len-i),tmpchunk,len-i);
118 MDupdate(&MD, tmpchunk, (len-i)*8);
128 void checksum_init(void)
134 static MDstruct sumMD;
135 static int sumresidue;
136 static char sumrbuf[CSUM_CHUNK];
144 void sum_update(char *p,int len)
148 i = MIN(CSUM_CHUNK-sumresidue,len);
149 bcopy(p,sumrbuf+sumresidue,i);
150 MDupdate(&sumMD, sumrbuf, (i+sumresidue)*8);
155 for(i = 0; i + CSUM_CHUNK <= len; i += CSUM_CHUNK) {
156 bcopy(p+i,sumrbuf,CSUM_CHUNK);
157 MDupdate(&sumMD, sumrbuf, CSUM_CHUNK*8);
162 bcopy(p+i,sumrbuf,sumresidue);
168 void sum_end(char *sum)
171 MDupdate(&sumMD, sumrbuf, sumresidue*8);
173 SIVAL(sum,0,sumMD.buffer[0]);
174 SIVAL(sum,4,sumMD.buffer[1]);
175 SIVAL(sum,8,sumMD.buffer[2]);
176 SIVAL(sum,12,sumMD.buffer[3]);
181 int main(int argc,char *argv[])
183 char sum[SUM_LENGTH];
188 for (i=1;i<argc;i++) {
190 if (stat(argv[i],&st) == 0) {
191 file_checksum(argv[i],sum,st.st_size);
192 for (j=0;j<SUM_LENGTH;j++)
193 printf("%02X",(unsigned char)sum[j]);
194 printf(" %s\n",argv[i]);