Aren/NetBSD
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Fix a bug so that MD-optimized in4_cksum() now works.

Browse Source 
While here; rewrite header checksum calculation in assembler.
This commit is contained in:
ragge 2001-04-28 09:36:01 +00:00
parent 862125c057
commit 8f8a96a056
1 changed files with 45 additions and 26 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

71
sys/arch/vax/vax/in4_cksum.c
View File

@ -1,4 +1,4 @@
/* $NetBSD: in4_cksum.c,v 1.1 2000/06/07 19:31:33 matt Exp $ */
/* $NetBSD: in4_cksum.c,v 1.2 2001/04/28 09:36:01 ragge Exp $ */
/*
* Copyright (C) 1999 WIDE Project.
@ -74,6 +74,15 @@
#include <netinet/ip.h>
#include <netinet/ip_var.h>
#ifdef CKSUMDEBUG
int in4_cksum_md_debug(struct mbuf *m, u_int8_t nxt, int off, int len);
#define in4_cksum in4_cksum_md_debug
#include <netinet/in4_cksum.c>
#undef in4_cksum
#undef ADDCARRY
#undef REDUCE
#endif
/*
* Checksum routine for Internet Protocol family headers.
* This is only for IPv4 pseudo header checksum.
@ -84,6 +93,7 @@
* This implementation is VAX version.
*/
#define REDUCE {sum = (sum & 0xffff) + (sum >> 16);}
#define ADDCARRY {if (sum > 0xffff) sum -= 0xffff;}
#define ADVANCE(n) {w += n; mlen -= n;}
@ -104,39 +114,43 @@ in4_cksum(struct mbuf *m, u_int8_t nxt, int off, int len)
u_int32_t sum = 0;
int mlen = 0;
int byte_swapped = 0;
#ifdef CKSUMDEBUG
int debugrv = in4_cksum_md_debug(m, nxt, off, len);
#endif
if (off > 0) {
struct ipovly ipov;
/* pseudo header */
if (off < sizeof(struct ipovly))
panic("in4_cksum: offset too short");
if (m->m_len < sizeof(struct ip))
panic("in4_cksum: bad mbuf chain");
bzero(&ipov, sizeof(ipov));
ipov.ih_len = htons(len);
ipov.ih_pr = nxt;
ipov.ih_src = mtod(m, struct ip *)->ip_src;
ipov.ih_dst = mtod(m, struct ip *)->ip_dst;
w = (u_int8_t *)&ipov;
#ifdef DIAGNOSTIC
if (off < sizeof(struct ipovly))
panic("in4_cksum: offset too short");
if (m->m_len < sizeof(struct ip))
panic("in4_cksum: bad mbuf chain");
#endif
/* assumes sizeof(ipov) == 20 */
ADDL; ADWC; ADWC; ADWC;
ADWC; ADDC;
__asm __volatile("
movzwl 16(ap),%0 # mov len to sum
addb2 8(ap),%0 # add proto to sum
rotl $8,%0,%0 # htons, carry is preserved
adwc 12(%2),%0 # add src ip
adwc 16(%2),%0 # add dst ip
adwc $0,%0 # clean up carry
" : "=r" (sum) : "0" (sum), "r" (mtod(m, void *)));
/* skip unnecessary part */
while (m && off > 0) {
if (m->m_len > off)
break;
off -= m->m_len;
m = m->m_next;
}
/* skip unnecessary part */
while (m && off > 0) {
if (m->m_len > off)
break;
off -= m->m_len;
m = m->m_next;
}
for (;m && len; m = m->m_next) {
if ((mlen = m->m_len) == 0)
continue;
w = mtod(m, u_int8_t *) + off;
off = 0;
w = mtod(m, u_int8_t *);
if (off) {
w += off;
mlen -= off;
off = 0;
}
if (len < mlen)
mlen = len;
len -= mlen;
@ -207,5 +221,10 @@ in4_cksum(struct mbuf *m, u_int8_t nxt, int off, int len)
}
REDUCE;
ADDCARRY;
#ifdef CKSUMDEBUG
if ((sum ^ 0xffff) != debugrv)
printf("in4_cksum: rv != debugrv (rv %x debugrv %x)\n",
(sum ^ 0xffff), debugrv);
#endif
return (sum ^ 0xffff);
}