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Get rid of the old XNS checksum code and implement it the IPX way.

Browse Source 
PR:		13374
Submitted by:	Boris Popov <bp@butya.kz>
This commit is contained in:
John Hay 1999-08-28 18:21:55 +00:00
parent 3dec6735e5
commit 01d3efc077
8 changed files with 85 additions and 213 deletions
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1
sys/netipx/ipx.h
View File

@ -95,6 +95,7 @@
#define SO_ALL_PACKETS 7
#define SO_MTU 8
#define SO_IPXTUN_ROUTE 9
#define SO_IPX_CHECKSUM 10
/*
* IPX addressing

217
sys/netipx/ipx_cksum.c
View File

@ -38,173 +38,76 @@
#include <sys/param.h>
#include <sys/mbuf.h>
#include <sys/libkern.h>
#include <netipx/ipx.h>
#include <netipx/ipx_var.h>
/*
* Checksum routine for Network Systems Protocol Packets (Big-Endian).
*
* This routine is very heavily used in the network
* code and should be modified for each CPU to be as fast as possible.
*/
#define ADDCARRY(x) { if ((x) > 65535) (x) -= 65535; }
#define FOLD(x) {l_util.l = (x); (x) = l_util.s[0] + l_util.s[1]; ADDCARRY(x);}
#define SUMADV sum += *w++
u_short
ipx_cksum(m, len)
struct mbuf *m;
int len;
{
register u_short *w;
register int sum = 0;
register int mlen = 0;
register int sum2;
ipx_cksum(struct mbuf *m, int len) {
u_int32_t sum = 0;
u_short *w;
u_char oldtc;
int mlen, words;
struct ipx *ipx;
union {
u_short s[2];
long l;
} l_util;
u_char b[2];
u_short w;
} buf;
for (;m != NULL && len; m = m->m_next) {
if (m->m_len == 0)
continue;
/*
* Each trip around loop adds in
* word from one mbuf segment.
*/
w = mtod(m, u_short *);
if (mlen == -1) {
/*
* There is a byte left from the last segment;
* ones-complement add it into the checksum.
*/
#if BYTE_ORDER == BIG_ENDIAN
sum += *(u_char *)w;
#else
sum += *(u_char *)w << 8;
#endif
sum += sum;
w = (u_short *)(1 + (char *)w);
mlen = m->m_len - 1;
len--;
FOLD(sum);
} else
mlen = m->m_len;
if (len < mlen)
mlen = len;
len -= mlen;
/*
* We can do a 16 bit ones complement sum using
* 32 bit arithmetic registers for adding,
* with carries from the low added
* into the high (by normal carry-chaining)
* so long as we fold back before 16 carries have occured.
*/
if (1 & (int) w)
goto uuuuglyy;
#ifndef TINY
/* -DTINY reduces the size from 1250 to 550, but slows it down by 22% */
while ((mlen -= 32) >= 0) {
sum += w[0]; sum += sum; sum += w[1]; sum += sum;
sum += w[2]; sum += sum; sum += w[3]; sum += sum;
sum += w[4]; sum += sum; sum += w[5]; sum += sum;
sum += w[6]; sum += sum; sum += w[7]; sum += sum;
FOLD(sum);
sum += w[8]; sum += sum; sum += w[9]; sum += sum;
sum += w[10]; sum += sum; sum += w[11]; sum += sum;
sum += w[12]; sum += sum; sum += w[13]; sum += sum;
sum += w[14]; sum += sum; sum += w[15]; sum += sum;
FOLD(sum);
w += 16;
ipx = mtod(m, struct ipx*);
oldtc = ipx->ipx_tc;
ipx->ipx_tc = 0;
w = &ipx->ipx_len;
len -= 2;
mlen = 2;
for(;;) {
mlen = imin(m->m_len - mlen, len);
words = mlen / 2;
len -= mlen & ~1;
while (words >= 16) {
SUMADV; SUMADV; SUMADV; SUMADV;
SUMADV; SUMADV; SUMADV; SUMADV;
SUMADV; SUMADV; SUMADV; SUMADV;
SUMADV; SUMADV; SUMADV; SUMADV;
words -= 16;
}
mlen += 32;
#endif
while ((mlen -= 8) >= 0) {
sum += w[0]; sum += sum; sum += w[1]; sum += sum;
sum += w[2]; sum += sum; sum += w[3]; sum += sum;
FOLD(sum);
w += 4;
while (words--)
SUMADV;
if (len == 0)
break;
mlen &= 1;
if (mlen) {
buf.b[0] = *(u_char*)w;
if (--len == 0) {
buf.b[1] = 0;
sum += buf.w;
break;
}
}
mlen += 8;
while ((mlen -= 2) >= 0) {
sum += *w++; sum += sum;
}
goto commoncase;
uuuuglyy:
#if BYTE_ORDER == BIG_ENDIAN
#define ww(n) (((u_char *)w)[n + n + 1])
#define vv(n) (((u_char *)w)[n + n])
#else
#if BYTE_ORDER == LITTLE_ENDIAN
#define vv(n) (((u_char *)w)[n + n + 1])
#define ww(n) (((u_char *)w)[n + n])
#endif
#endif
sum2 = 0;
#ifndef TINY
while ((mlen -= 32) >= 0) {
sum += ww(0); sum += sum; sum += ww(1); sum += sum;
sum += ww(2); sum += sum; sum += ww(3); sum += sum;
sum += ww(4); sum += sum; sum += ww(5); sum += sum;
sum += ww(6); sum += sum; sum += ww(7); sum += sum;
FOLD(sum);
sum += ww(8); sum += sum; sum += ww(9); sum += sum;
sum += ww(10); sum += sum; sum += ww(11); sum += sum;
sum += ww(12); sum += sum; sum += ww(13); sum += sum;
sum += ww(14); sum += sum; sum += ww(15); sum += sum;
FOLD(sum);
sum2 += vv(0); sum2 += sum2; sum2 += vv(1); sum2 += sum2;
sum2 += vv(2); sum2 += sum2; sum2 += vv(3); sum2 += sum2;
sum2 += vv(4); sum2 += sum2; sum2 += vv(5); sum2 += sum2;
sum2 += vv(6); sum2 += sum2; sum2 += vv(7); sum2 += sum2;
FOLD(sum2);
sum2 += vv(8); sum2 += sum2; sum2 += vv(9); sum2 += sum2;
sum2 += vv(10); sum2 += sum2; sum2 += vv(11); sum2 += sum2;
sum2 += vv(12); sum2 += sum2; sum2 += vv(13); sum2 += sum2;
sum2 += vv(14); sum2 += sum2; sum2 += vv(15); sum2 += sum2;
FOLD(sum2);
w += 16;
}
mlen += 32;
#endif
while ((mlen -= 8) >= 0) {
sum += ww(0); sum += sum; sum += ww(1); sum += sum;
sum += ww(2); sum += sum; sum += ww(3); sum += sum;
FOLD(sum);
sum2 += vv(0); sum2 += sum2; sum2 += vv(1); sum2 += sum2;
sum2 += vv(2); sum2 += sum2; sum2 += vv(3); sum2 += sum2;
FOLD(sum2);
w += 4;
}
mlen += 8;
while ((mlen -= 2) >= 0) {
sum += ww(0); sum += sum;
sum2 += vv(0); sum2 += sum2;
w++;
}
sum += (sum2 << 8);
commoncase:
if (mlen == -1) {
#if BYTE_ORDER == BIG_ENDIAN
sum += *(u_char *)w << 8;
#else
sum += *(u_char *)w;
#endif
}
FOLD(sum);
m = m->m_next;
if (m == NULL)
break;
w = mtod(m, u_short*);
if (mlen) {
buf.b[1] = *(u_char*)w;
sum += buf.w;
((u_char*)w)++;
if (--len == 0)
break;
}
}
if (mlen == -1) {
/* We had an odd number of bytes to sum; assume a garbage
byte of zero and clean up */
sum += sum;
FOLD(sum);
}
/*
* sum has already been kept to low sixteen bits.
* just examine result and exit.
*/
if(sum == 0xffff)
sum = 0;
ipx->ipx_tc = oldtc;
sum = (sum & 0xffff) + (sum >> 16);
if (sum >= 0x10000)
sum++;
if (sum)
sum = ~sum;
return (sum);
}

50
sys/netipx/ipx_input.c
View File

@ -130,9 +130,7 @@ ipxintr()
register struct mbuf *m;
register struct ipxpcb *ipxp;
struct ipx_ifaddr *ia;
register int i;
int len, s;
char oddshortpacket = 0;
next:
/*
@ -171,15 +169,6 @@ ipxintr()
ipx = mtod(m, struct ipx *);
len = ntohs(ipx->ipx_len);
if ((len < m->m_pkthdr.len) && (oddshortpacket = len & 1)) {
/*
* If this packet is of odd length, and the length
* inside the header is less than the received packet
* length, preserve garbage byte for possible checksum.
*/
len++;
}
/*
* Check that the amount of data in the buffers
* is as at least much as the IPX header would have us expect.
@ -197,9 +186,8 @@ ipxintr()
} else
m_adj(m, len - m->m_pkthdr.len);
}
if (ipxcksum && ((i = ipx->ipx_sum) != 0xffff)) {
ipx->ipx_sum = 0;
if (i != (ipx->ipx_sum = ipx_cksum(m, len))) {
if (ipxcksum && ipx->ipx_sum != 0xffff) {
if (ipx->ipx_sum != ipx_cksum(m, len)) {
ipxstat.ipxs_badsum++;
goto bad;
}
@ -274,9 +262,6 @@ ipxintr()
* Switch out to protocol's input routine.
*/
if (ipxp != NULL) {
if (oddshortpacket) {
m_adj(m, -1);
}
ipxstat.ipxs_delivered++;
if ((ipxp->ipxp_flags & IPXP_ALL_PACKETS) == 0)
switch (ipx->ipx_pt) {
@ -396,32 +381,15 @@ struct mbuf *m;
goto cleanup;
}
}
/* XXX
* I think the checksum generation is bogus. According to the NLSP
* spec the ipx_tc (hop count) field and the ipx_sum should be
* zero'ed before generating the checksum, ie. it should not be
* necesary to recompute it in the forwarding function.
/*
* We don't need to recompute checksum because ipx_tc field
* is ignored by checksum calculation routine, however
* it may be desirable to reset checksum if ipxcksum == 0
*/
/* need to adjust checksum */
if (ipxcksum && ipx->ipx_sum != 0xffff) {
union bytes {
u_char c[4];
u_short s[2];
long l;
} x;
register int shift;
x.l = 0;
x.c[0] = agedelta;
shift = (((((int)ntohs(ipx->ipx_len)) + 1) >> 1) - 2) & 0xf;
x.l = ipx->ipx_sum + (x.s[0] << shift);
x.l = x.s[0] + x.s[1];
x.l = x.s[0] + x.s[1];
if (x.l == 0xffff)
ipx->ipx_sum = 0;
else
ipx->ipx_sum = x.l;
} else
#if 0
if (!ipxcksum)
ipx->ipx_sum = 0xffff;
#endif
error = ipx_outputfl(m, &ipx_droute, flags);
if (error == 0) {

8
sys/netipx/ipx_outputfl.c
View File

@ -247,12 +247,8 @@ ipx_output_type20(m)
ipx->ipx_dna.x_net = dst.sipx_addr.x_net;
m1 = m_copym(m, 0, M_COPYALL, M_DONTWAIT);
if(ipx->ipx_sum != 0xffff) {
int len = ntohs(ipx->ipx_len);
ipx->ipx_sum = 0;
len = ((len - 1) | 1) + 1;
ipx->ipx_sum = ipx_cksum(m, len);
}
if(ipx->ipx_sum != 0xffff)
ipx->ipx_sum = ipx_cksum(m, ntohs(ipx->ipx_len));
if(m1) {
error = (*ifp->if_output)(ifp, m1,
(struct sockaddr *)&dst, NULL);

2
sys/netipx/ipx_pcb.c
View File

@ -66,6 +66,8 @@ ipx_pcballoc(so, head, p)
return (ENOBUFS);
bzero(ipxp, sizeof *ipxp);
ipxp->ipxp_socket = so;
if (ipxcksum)
ipxp->ipxp_flags |= IPXP_CHECKSUM;
insque(ipxp, head);
so->so_pcb = (caddr_t)ipxp;
return (0);

1
sys/netipx/ipx_pcb.h
View File

@ -64,6 +64,7 @@ struct ipxpcb {
#define IPXP_RAWIN 0x2 /* show headers on input */
#define IPXP_RAWOUT 0x4 /* show header on output */
#define IPXP_ALL_PACKETS 0x8 /* Turn off higher proto processing */
#define IPXP_CHECKSUM 0x10 /* use checksum on this socket */
#define IPX_WILDCARD 1

13
sys/netipx/ipx_usrreq.c
View File

@ -214,7 +214,7 @@ ipx_output(ipxp, m0)
m = mprev;
if ((m->m_flags & M_EXT) == 0 &&
(m->m_len + m->m_data < &m->m_dat[MLEN])) {
m->m_len++;
mtod(m, char*)[m->m_len++] = 0;
} else {
struct mbuf *m1 = m_get(M_DONTWAIT, MT_DATA);
@ -250,9 +250,7 @@ ipx_output(ipxp, m0)
ipx->ipx_len = htons((u_short)len);
if (ipxcksum) {
ipx->ipx_sum = 0;
len = ((len - 1) | 1) + 1;
if (ipxp->ipxp_flags & IPXP_CHECKSUM) {
ipx->ipx_sum = ipx_cksum(m, len);
} else
ipx->ipx_sum = 0xffff;
@ -333,6 +331,10 @@ ipx_ctloutput(so, sopt)
case SO_HEADERS_ON_INPUT:
mask = IPXP_RAWIN;
goto get_flags;
case SO_IPX_CHECKSUM:
mask = IPXP_CHECKSUM;
goto get_flags;
case SO_HEADERS_ON_OUTPUT:
mask = IPXP_RAWOUT;
@ -372,6 +374,9 @@ ipx_ctloutput(so, sopt)
mask = IPXP_RAWIN;
goto set_head;
case SO_IPX_CHECKSUM:
mask = IPXP_CHECKSUM;
case SO_HEADERS_ON_OUTPUT:
mask = IPXP_RAWOUT;
set_head:

6
sys/netipx/spx_usrreq.c
View File

@ -1081,11 +1081,7 @@ spx_output(cb, m0)
si->si_ack = htons(cb->s_ack);
if (ipxcksum) {
si->si_sum = 0;
len = ntohs(si->si_len);
if (len & 1)
len++;
si->si_sum = ipx_cksum(m, len);
si->si_sum = ipx_cksum(m, ntohs(si->si_len));
} else
si->si_sum = 0xffff;