path: root/net/x25/x25_subr.c
diff options
authorShaun Pereira <spereira@tusc.com.au>2005-06-22 22:16:17 -0700
committerDavid S. Miller <davem@davemloft.net>2005-06-22 22:16:17 -0700
commitebc3f64b864fc16a594c2e63bf55a55c7d42084b (patch)
tree95040f32ad5902051527b91966118e565d48865b /net/x25/x25_subr.c
parent[X25]: Selective sub-address matching with call user data. (diff)
[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>
Diffstat (limited to 'net/x25/x25_subr.c')
1 files changed, 18 insertions, 5 deletions
diff --git a/net/x25/x25_subr.c b/net/x25/x25_subr.c
index c349bbd61684..7fd872ad0c20 100644
--- a/net/x25/x25_subr.c
+++ b/net/x25/x25_subr.c
@@ -19,6 +19,8 @@
* mar/20/00 Daniela Squassoni Disabling/enabling of facilities
* negotiation.
* jun/24/01 Arnaldo C. Melo use skb_queue_purge, cleanups
+ * apr/04/15 Shaun Pereira Fast select with no
+ * restriction on response.
#include <linux/kernel.h>
@@ -127,8 +129,12 @@ void x25_write_internal(struct sock *sk, int frametype)
len += 1 + X25_ADDR_LEN + X25_MAX_FAC_LEN +
- len += 1 + X25_MAX_FAC_LEN + X25_MAX_CUD_LEN;
+ case X25_CALL_ACCEPTED: /* fast sel with no restr on resp */
+ if(x25->facilities.reverse & 0x80) {
+ len += 1 + X25_MAX_FAC_LEN + X25_MAX_CUD_LEN;
+ } else {
+ len += 1 + X25_MAX_FAC_LEN;
+ }
@@ -203,9 +209,16 @@ void x25_write_internal(struct sock *sk, int frametype)
dptr = skb_put(skb, len);
memcpy(dptr, facilities, len);
- dptr = skb_put(skb, x25->calluserdata.cudlength);
- memcpy(dptr, x25->calluserdata.cuddata,
- x25->calluserdata.cudlength);
+ /* fast select with no restriction on response
+ allows call user data. Userland must
+ ensure it is ours and not theirs */
+ if(x25->facilities.reverse & 0x80) {
+ dptr = skb_put(skb,
+ x25->calluserdata.cudlength);
+ memcpy(dptr, x25->calluserdata.cuddata,
+ x25->calluserdata.cudlength);
+ }
x25->calluserdata.cudlength = 0;