2010-06-29 20:15 keltezéssel, Martin Holste írta:
> Yep, I was looking at the latest 11 release SRPM I could find, which
> was still libnet-1.1.2.1-140.22. In one of the previous threads on
> this mailing list, a very valuable link was provided which has the
> exact source code needed for the patch:
> http://www.securityfocus.com/archive/89/384197/30/90/threaded .
>
OK. Instead of just checking dates, I inspected now the SuSE patches
more closely. Another patch is already applied to src/libnet_checksum.c
in the patch called libnet-1.1.2.1-strict-aliasing-fix.diff which
replaces the libnet_in_cksum() function with another one. The relevant
part of the patch is:
---
src/libnet_checksum.c
+++
src/libnet_checksum.c
@@ -58,6 +58,27
@@
return
(sum);
}
+#include
<assert.h>
+/* same as above, just takes *u_int32_t
*/
+int
+libnet_in_cksum32(u_int32_t *addr32, int
len)
+{
+ int
sum;
+
+ sum =
0;
+
+ while (len >
3)
+
{
+ sum += (*addr32) >>
16;
+ sum += (*addr32) &
0x0000ffff;
+ len -=
4;
+
addr32++;
+
}
+ assert(len ==
0);
+
+ return
(sum);
+}
+
int
libnet_toggle_checksum(libnet_t *l, libnet_ptag_t ptag, int mode)
{
@@ -173,7 +194,7 @@
}
else
{
- sum = libnet_in_cksum((u_int16_t *)&iph_p->ip_src, 8);
+ sum = libnet_in_cksum32((u_int32_t *)&iph_p->ip_src, 8);
}
sum += ntohs(IPPROTO_TCP + len);
sum += libnet_in_cksum((u_int16_t *)tcph_p, len);
@@ -191,7 +212,7 @@
}
else
{
- sum = libnet_in_cksum((u_int16_t *)&iph_p->ip_src, 8);
+ sum = libnet_in_cksum32((u_int32_t *)&iph_p->ip_src, 8);
}
sum += ntohs(IPPROTO_UDP + len);
sum += libnet_in_cksum((u_int16_t *)udph_p, len);
With my limited C knowledge I don't know how much is this different from
the one on securityfocus.com. Did you test 11.X that the problem is
still there?
Bye,
CzP