[X25]: Fast select with no restriction on response
This patch is a follow up to patch 1 regarding "Selective Sub Address
matching with call user data". It allows use of the Fast-Select-Acceptance
optional user facility for X.25.
This patch just implements fast select with no restriction on response
(NRR). What this means (according to ITU-T Recomendation 10/96 section
6.16) is that if in an incoming call packet, the relevant facility bits are
set for fast-select-NRR, then the called DTE can issue a direct response to
the incoming packet using a call-accepted packet that contains
call-user-data. This patch allows such a response.
The called DTE can also respond with a clear-request packet that contains
call-user-data. However, this feature is currently not implemented by the
patch.
How is Fast Select Acceptance used?
By default, the system does not allow fast select acceptance (as before).
To enable a response to fast select acceptance,
After a listen socket in created and bound as follows
socket(AF_X25, SOCK_SEQPACKET, 0);
bind(call_soc, (struct sockaddr *)&locl_addr, sizeof(locl_addr));
but before a listen system call is made, the following ioctl should be used.
ioctl(call_soc,SIOCX25CALLACCPTAPPRV);
Now the listen system call can be made
listen(call_soc, 4);
After this, an incoming-call packet will be accepted, but no call-accepted
packet will be sent back until the following system call is made on the socket
that accepts the call
ioctl(vc_soc,SIOCX25SENDCALLACCPT);
The network (or cisco xot router used for testing here) will allow the
application server's call-user-data in the call-accepted packet,
provided the call-request was made with Fast-select NRR.
Signed-off-by: Shaun Pereira <spereira@tusc.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/x25/x25_facilities.c b/net/x25/x25_facilities.c
index a21bdb9..54278b9 100644
--- a/net/x25/x25_facilities.c
+++ b/net/x25/x25_facilities.c
@@ -17,6 +17,8 @@
* X.25 001 Split from x25_subr.c
* mar/20/00 Daniela Squassoni Disabling/enabling of facilities
* negotiation.
+ * apr/14/05 Shaun Pereira - Allow fast select with no restriction
+ * on response.
*/
#include <linux/kernel.h>
@@ -43,9 +45,31 @@
case X25_FAC_CLASS_A:
switch (*p) {
case X25_FAC_REVERSE:
- facilities->reverse = p[1] & 0x01;
- *vc_fac_mask |= X25_MASK_REVERSE;
- break;
+ if((p[1] & 0x81) == 0x81) {
+ facilities->reverse = p[1] & 0x81;
+ *vc_fac_mask |= X25_MASK_REVERSE;
+ break;
+ }
+
+ if((p[1] & 0x01) == 0x01) {
+ facilities->reverse = p[1] & 0x01;
+ *vc_fac_mask |= X25_MASK_REVERSE;
+ break;
+ }
+
+ if((p[1] & 0x80) == 0x80) {
+ facilities->reverse = p[1] & 0x80;
+ *vc_fac_mask |= X25_MASK_REVERSE;
+ break;
+ }
+
+ if(p[1] == 0x00) {
+ facilities->reverse
+ = X25_DEFAULT_REVERSE;
+ *vc_fac_mask |= X25_MASK_REVERSE;
+ break;
+ }
+
case X25_FAC_THROUGHPUT:
facilities->throughput = p[1];
*vc_fac_mask |= X25_MASK_THROUGHPUT;
@@ -122,7 +146,7 @@
if (facilities->reverse && (facil_mask & X25_MASK_REVERSE)) {
*p++ = X25_FAC_REVERSE;
- *p++ = !!facilities->reverse;
+ *p++ = facilities->reverse;
}
if (facilities->throughput && (facil_mask & X25_MASK_THROUGHPUT)) {
@@ -171,7 +195,7 @@
/*
* They want reverse charging, we won't accept it.
*/
- if (theirs.reverse && ours->reverse) {
+ if ((theirs.reverse & 0x01 ) && (ours->reverse & 0x01)) {
SOCK_DEBUG(sk, "X.25: rejecting reverse charging request");
return -1;
}