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Fix for chains containing interior mbufs with odd length.

This commit is contained in:
jonathan 1997-07-22 07:36:18 +00:00
parent 825760d107
commit a6c118666a
1 changed files with 25 additions and 8 deletions
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33
sys/arch/mips/mips/in_cksum.c
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@ -1,4 +1,4 @@
/* $NetBSD: in_cksum.c,v 1.1 1997/07/20 22:42:45 jonathan Exp $ */
/* $NetBSD: in_cksum.c,v 1.2 1997/07/22 07:36:18 jonathan Exp $ */
/*
* Copyright (c) 1993 Regents of the University of California.
@ -51,17 +51,18 @@ union memptr {
unsigned char *c;
};
static __inline u_int32_t fastsum __P((union memptr buf, int n, u_int sum));
static __inline u_int32_t fastsum __P((union memptr, int n, u_int sum, int odd));
u_int32_t
fastsum(buf, n, sum)
fastsum(buf, n, oldsum, odd)
union memptr buf;
int n;
unsigned int sum;
unsigned int oldsum;
{
unsigned long hilo = 0, high = 0;
unsigned long w0, w1;
register unsigned int sum = 0;
if (buf.u & 0x3) {
/* 16-bit-align. Have to do this first so short buffers done right. */
@ -178,9 +179,22 @@ fastsum(buf, n, sum)
/* handle trailing byte */
if (n > 0)
sum += *buf.c;
/*
* compensate for a trailing byte in previous mbuf
* by byteswapping the aligned sum of this mbuf.
*/
if (odd & 0x01) {
sum = (sum & 0xffff) + (sum >> 16);
sum = (sum & 0xffff) + (sum >> 16);
sum = oldsum + ((sum >> 8) & 0xff) + ((sum & 0xff) << 8);
} else {
/* add upper and lower halfwords together to get full sum */
sum = (sum & 0xffff) + (sum >> 16);
sum = oldsum + sum;
sum = (sum & 0xffff) + (sum >> 16);
}
/* fold carry from combining sums */
sum = (sum & 0xffff) + (sum >> 16);
return(sum);
}
@ -198,16 +212,19 @@ in_cksum(m, len)
register /*u_short **/ union memptr w;
register u_int32_t sum = 0;
register int mlen;
register int odd = 0;
for ( ; m && len; m = m->m_next) {
mlen = m->m_len;
if (mlen == 0)
continue;
if (mlen > len)
mlen = len;
w.s = mtod(m, u_short *);
sum = fastsum(w, mlen, sum);
w.c = mtod(m, u_char *);
sum = fastsum(w, mlen, sum, odd);
len -= mlen;
odd += mlen;
}
if (len != 0) {
printf("in_cksum: out of data, %d\n", len);