79 lines
2.2 KiB
Text
79 lines
2.2 KiB
Text
|
$NetBSD: patch-af,v 1.1 2006/03/30 13:51:29 salo Exp $
|
||
|
|
|
||
|
|
--- ars.c.orig 2003-07-28 11:00:54.000000000 +0200
|
||
|
|
+++ ars.c 2005-11-05 21:35:00.000000000 +0100
|
||
|
|
@@ -372,7 +372,7 @@
|
||
|
|
}
|
||
|
|
if (nbytes == 1) {
|
||
|
|
oddbyte = 0;
|
||
|
|
- *((u_int16_t *) &oddbyte) = *(u_int8_t *) buf;
|
||
|
|
+ *((u_int8_t *) &oddbyte) = *((u_int8_t *) buf);
|
||
|
|
sum += oddbyte;
|
||
|
|
}
|
||
|
|
sum = (sum >> 16) + (sum & 0xffff);
|
||
|
|
@@ -381,6 +381,13 @@
|
||
|
|
}
|
||
|
|
|
||
|
|
/* Multiple buffers checksum facility */
|
||
|
|
+/*
|
||
|
|
+ * Important facts about the checksum (sum = ~cksum, Ai are bytes):
|
||
|
|
+ * 1. sum(A0...A2i-1,A2i...A2n-1) = sum(A0...A2i-1) + sum(A2i...B2n-1),
|
||
|
|
+ * 2. sum(A0...A2i,A2i+1...A2n-1) = sum(A0...A2i,0) + sum(0,A2i+1...A2n-1)
|
||
|
|
+ * 3. sum(A0...A2n-1,A2n) = sum(A0...A2n-1,A2n,0) (ex definitiones)
|
||
|
|
+ * 4. sum(0,A0...Ak) = swap_bytes(sum(A0...Ak))
|
||
|
|
+ */
|
||
|
|
u_int16_t ars_multi_cksum(struct mc_context *c, int op, void *vbuf,
|
||
|
|
size_t nbytes)
|
||
|
|
{
|
||
|
|
@@ -394,38 +401,27 @@
|
||
|
|
c->old = 0;
|
||
|
|
return -ARS_OK;
|
||
|
|
} else if (op == ARS_MC_UPDATE) {
|
||
|
|
- if (c->oddbyte_flag) {
|
||
|
|
- u_int8_t *x = (u_int8_t*)&oddbyte;
|
||
|
|
- oddbyte = 0;
|
||
|
|
- *((u_int16_t *) &oddbyte) = c->oddbyte << 8;
|
||
|
|
- *((u_int16_t *) &oddbyte) |= *(u_int8_t *) buf;
|
||
|
|
- oddbyte = (x[0] << 8) | x[1]; /* fix endianess */
|
||
|
|
- c->old += oddbyte;
|
||
|
|
- nbytes--;
|
||
|
|
- c->oddbyte_flag = 0;
|
||
|
|
- /* We need to stay aligned -- bad slowdown, fix? */
|
||
|
|
- tmp = alloca(nbytes);
|
||
|
|
- memcpy(tmp, vbuf+1, nbytes);
|
||
|
|
- buf = tmp;
|
||
|
|
- }
|
||
|
|
- sum = c->old;
|
||
|
|
+ sum = 0;
|
||
|
|
while (nbytes > 1) {
|
||
|
|
sum += *buf++;
|
||
|
|
nbytes -= 2;
|
||
|
|
}
|
||
|
|
- c->old = sum;
|
||
|
|
if (nbytes == 1) {
|
||
|
|
- c->oddbyte = *(u_int8_t*) buf;
|
||
|
|
- c->oddbyte_flag++;
|
||
|
|
+ oddbyte = 0;
|
||
|
|
+ *((u_int8_t *) &oddbyte) = *((u_int8_t *) buf);
|
||
|
|
+ sum += oddbyte;
|
||
|
|
}
|
||
|
|
+ if (c->oddbyte_flag) {
|
||
|
|
+ /* reverse checksum endianness */
|
||
|
|
+ sum = (sum >> 16) + (sum & 0xffff);
|
||
|
|
+ sum += (sum >> 16);
|
||
|
|
+ sum = ((sum & 0xff00) >> 8) | ((sum & 0xff) << 8);
|
||
|
|
+ }
|
||
|
|
+ c->old += sum;
|
||
|
|
+ c->oddbyte_flag ^= (nbytes == 1 ? 1 : 0);
|
||
|
|
return -ARS_OK;
|
||
|
|
} else if (op == ARS_MC_FINAL) {
|
||
|
|
sum = c->old;
|
||
|
|
- if (c->oddbyte_flag == 1) {
|
||
|
|
- oddbyte = 0;
|
||
|
|
- *((u_int16_t *) &oddbyte) = c->oddbyte;
|
||
|
|
- sum += oddbyte;
|
||
|
|
- }
|
||
|
|
sum = (sum >> 16) + (sum & 0xffff);
|
||
|
|
sum += (sum >> 16);
|
||
|
|
return (u_int16_t) ~sum;
|