linux-sg2042/net/x25/x25_subr.c

377 lines
9.2 KiB
C
Raw Normal View History

/*
* X.25 Packet Layer release 002
*
* This is ALPHA test software. This code may break your machine,
* randomly fail to work with new releases, misbehave and/or generally
* screw up. It might even work.
*
* This code REQUIRES 2.1.15 or higher
*
* This module:
* This module is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
* History
* X.25 001 Jonathan Naylor Started coding.
* X.25 002 Jonathan Naylor Centralised disconnection processing.
* mar/20/00 Daniela Squassoni Disabling/enabling of facilities
* negotiation.
* jun/24/01 Arnaldo C. Melo use skb_queue_purge, cleanups
[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>
2005-06-23 13:16:17 +08:00
* apr/04/15 Shaun Pereira Fast select with no
* restriction on response.
*/
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 16:04:11 +08:00
#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/skbuff.h>
#include <net/sock.h>
#include <net/tcp_states.h>
#include <net/x25.h>
/*
* This routine purges all of the queues of frames.
*/
void x25_clear_queues(struct sock *sk)
{
struct x25_sock *x25 = x25_sk(sk);
skb_queue_purge(&sk->sk_write_queue);
skb_queue_purge(&x25->ack_queue);
skb_queue_purge(&x25->interrupt_in_queue);
skb_queue_purge(&x25->interrupt_out_queue);
skb_queue_purge(&x25->fragment_queue);
}
/*
* This routine purges the input queue of those frames that have been
* acknowledged. This replaces the boxes labelled "V(a) <- N(r)" on the
* SDL diagram.
*/
void x25_frames_acked(struct sock *sk, unsigned short nr)
{
struct sk_buff *skb;
struct x25_sock *x25 = x25_sk(sk);
int modulus = x25->neighbour->extended ? X25_EMODULUS : X25_SMODULUS;
/*
* Remove all the ack-ed frames from the ack queue.
*/
if (x25->va != nr)
while (skb_peek(&x25->ack_queue) && x25->va != nr) {
skb = skb_dequeue(&x25->ack_queue);
kfree_skb(skb);
x25->va = (x25->va + 1) % modulus;
}
}
void x25_requeue_frames(struct sock *sk)
{
struct sk_buff *skb, *skb_prev = NULL;
/*
* Requeue all the un-ack-ed frames on the output queue to be picked
* up by x25_kick. This arrangement handles the possibility of an empty
* output queue.
*/
while ((skb = skb_dequeue(&x25_sk(sk)->ack_queue)) != NULL) {
if (!skb_prev)
skb_queue_head(&sk->sk_write_queue, skb);
else
skb_append(skb_prev, skb, &sk->sk_write_queue);
skb_prev = skb;
}
}
/*
* Validate that the value of nr is between va and vs. Return true or
* false for testing.
*/
int x25_validate_nr(struct sock *sk, unsigned short nr)
{
struct x25_sock *x25 = x25_sk(sk);
unsigned short vc = x25->va;
int modulus = x25->neighbour->extended ? X25_EMODULUS : X25_SMODULUS;
while (vc != x25->vs) {
if (nr == vc)
return 1;
vc = (vc + 1) % modulus;
}
return nr == x25->vs ? 1 : 0;
}
/*
* This routine is called when the packet layer internally generates a
* control frame.
*/
void x25_write_internal(struct sock *sk, int frametype)
{
struct x25_sock *x25 = x25_sk(sk);
struct sk_buff *skb;
unsigned char *dptr;
unsigned char facilities[X25_MAX_FAC_LEN];
unsigned char addresses[1 + X25_ADDR_LEN];
unsigned char lci1, lci2;
/*
* Default safe frame size.
*/
int len = X25_MAX_L2_LEN + X25_EXT_MIN_LEN;
/*
* Adjust frame size.
*/
switch (frametype) {
case X25_CALL_REQUEST:
len += 1 + X25_ADDR_LEN + X25_MAX_FAC_LEN + X25_MAX_CUD_LEN;
break;
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;
}
break;
case X25_CLEAR_REQUEST:
case X25_RESET_REQUEST:
len += 2;
break;
case X25_RR:
case X25_RNR:
case X25_REJ:
case X25_CLEAR_CONFIRMATION:
case X25_INTERRUPT_CONFIRMATION:
case X25_RESET_CONFIRMATION:
break;
default:
printk(KERN_ERR "X.25: invalid frame type %02X\n", frametype);
return;
}
if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL)
return;
/*
* Space for Ethernet and 802.2 LLC headers.
*/
skb_reserve(skb, X25_MAX_L2_LEN);
/*
* Make space for the GFI and LCI, and fill them in.
*/
dptr = skb_put(skb, 2);
lci1 = (x25->lci >> 8) & 0x0F;
lci2 = (x25->lci >> 0) & 0xFF;
if (x25->neighbour->extended) {
*dptr++ = lci1 | X25_GFI_EXTSEQ;
*dptr++ = lci2;
} else {
*dptr++ = lci1 | X25_GFI_STDSEQ;
*dptr++ = lci2;
}
/*
* Now fill in the frame type specific information.
*/
switch (frametype) {
case X25_CALL_REQUEST:
dptr = skb_put(skb, 1);
*dptr++ = X25_CALL_REQUEST;
len = x25_addr_aton(addresses, &x25->dest_addr,
&x25->source_addr);
dptr = skb_put(skb, len);
memcpy(dptr, addresses, len);
len = x25_create_facilities(facilities,
[X25]: allow ITU-T DTE facilities for x25 Allows use of the optional user facility to insert ITU-T (http://www.itu.int/ITU-T/) specified DTE facilities in call set-up x25 packets. This feature is optional; no facilities will be added if the ioctl is not used, and call setup packet remains the same as before. If the ioctls provided by the patch are used, then a facility marker will be added to the x25 packet header so that the called dte address extension facility can be differentiated from other types of facilities (as described in the ITU-T X.25 recommendation) that are also allowed in the x25 packet header. Facility markers are made up of two octets, and may be present in the x25 packet headers of call-request, incoming call, call accepted, clear request, and clear indication packets. The first of the two octets represents the facility code field and is set to zero by this patch. The second octet of the marker represents the facility parameter field and is set to 0x0F because the marker will be inserted before ITU-T type DTE facilities. Since according to ITU-T X.25 Recommendation X.25(10/96)- 7.1 "All networks will support the facility markers with a facility parameter field set to all ones or to 00001111", therefore this patch should work with all x.25 networks. While there are many ITU-T DTE facilities, this patch implements only the called and calling address extension, with placeholders in the x25_dte_facilities structure for the rest of the facilities. Testing: This patch was tested using a cisco xot router connected on its serial ports to an X.25 network, and on its lan ports to a host running an xotd daemon. It is also possible to test this patch using an xotd daemon and an x25tap patch, where the xotd daemons work back-to-back without actually using an x.25 network. See www.fyonne.net for details on how to do this. Signed-off-by: Shaun Pereira <spereira@tusc.com.au> Acked-by: Andrew Hendry <ahendry@tusc.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-22 16:01:31 +08:00
&x25->facilities,
&x25->dte_facilities,
x25->neighbour->global_facil_mask);
dptr = skb_put(skb, len);
memcpy(dptr, facilities, len);
dptr = skb_put(skb, x25->calluserdata.cudlength);
memcpy(dptr, x25->calluserdata.cuddata,
x25->calluserdata.cudlength);
x25->calluserdata.cudlength = 0;
break;
case X25_CALL_ACCEPTED:
dptr = skb_put(skb, 2);
*dptr++ = X25_CALL_ACCEPTED;
*dptr++ = 0x00; /* Address lengths */
len = x25_create_facilities(facilities,
&x25->facilities,
[X25]: allow ITU-T DTE facilities for x25 Allows use of the optional user facility to insert ITU-T (http://www.itu.int/ITU-T/) specified DTE facilities in call set-up x25 packets. This feature is optional; no facilities will be added if the ioctl is not used, and call setup packet remains the same as before. If the ioctls provided by the patch are used, then a facility marker will be added to the x25 packet header so that the called dte address extension facility can be differentiated from other types of facilities (as described in the ITU-T X.25 recommendation) that are also allowed in the x25 packet header. Facility markers are made up of two octets, and may be present in the x25 packet headers of call-request, incoming call, call accepted, clear request, and clear indication packets. The first of the two octets represents the facility code field and is set to zero by this patch. The second octet of the marker represents the facility parameter field and is set to 0x0F because the marker will be inserted before ITU-T type DTE facilities. Since according to ITU-T X.25 Recommendation X.25(10/96)- 7.1 "All networks will support the facility markers with a facility parameter field set to all ones or to 00001111", therefore this patch should work with all x.25 networks. While there are many ITU-T DTE facilities, this patch implements only the called and calling address extension, with placeholders in the x25_dte_facilities structure for the rest of the facilities. Testing: This patch was tested using a cisco xot router connected on its serial ports to an X.25 network, and on its lan ports to a host running an xotd daemon. It is also possible to test this patch using an xotd daemon and an x25tap patch, where the xotd daemons work back-to-back without actually using an x.25 network. See www.fyonne.net for details on how to do this. Signed-off-by: Shaun Pereira <spereira@tusc.com.au> Acked-by: Andrew Hendry <ahendry@tusc.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-22 16:01:31 +08:00
&x25->dte_facilities,
x25->vc_facil_mask);
dptr = skb_put(skb, len);
memcpy(dptr, facilities, len);
[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>
2005-06-23 13:16:17 +08:00
/* 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;
break;
case X25_CLEAR_REQUEST:
dptr = skb_put(skb, 3);
*dptr++ = frametype;
*dptr++ = x25->causediag.cause;
*dptr++ = x25->causediag.diagnostic;
break;
case X25_RESET_REQUEST:
dptr = skb_put(skb, 3);
*dptr++ = frametype;
*dptr++ = 0x00; /* XXX */
*dptr++ = 0x00; /* XXX */
break;
case X25_RR:
case X25_RNR:
case X25_REJ:
if (x25->neighbour->extended) {
dptr = skb_put(skb, 2);
*dptr++ = frametype;
*dptr++ = (x25->vr << 1) & 0xFE;
} else {
dptr = skb_put(skb, 1);
*dptr = frametype;
*dptr++ |= (x25->vr << 5) & 0xE0;
}
break;
case X25_CLEAR_CONFIRMATION:
case X25_INTERRUPT_CONFIRMATION:
case X25_RESET_CONFIRMATION:
dptr = skb_put(skb, 1);
*dptr = frametype;
break;
}
x25_transmit_link(skb, x25->neighbour);
}
/*
* Unpick the contents of the passed X.25 Packet Layer frame.
*/
int x25_decode(struct sock *sk, struct sk_buff *skb, int *ns, int *nr, int *q,
int *d, int *m)
{
struct x25_sock *x25 = x25_sk(sk);
unsigned char *frame = skb->data;
*ns = *nr = *q = *d = *m = 0;
switch (frame[2]) {
case X25_CALL_REQUEST:
case X25_CALL_ACCEPTED:
case X25_CLEAR_REQUEST:
case X25_CLEAR_CONFIRMATION:
case X25_INTERRUPT:
case X25_INTERRUPT_CONFIRMATION:
case X25_RESET_REQUEST:
case X25_RESET_CONFIRMATION:
case X25_RESTART_REQUEST:
case X25_RESTART_CONFIRMATION:
case X25_REGISTRATION_REQUEST:
case X25_REGISTRATION_CONFIRMATION:
case X25_DIAGNOSTIC:
return frame[2];
}
if (x25->neighbour->extended) {
if (frame[2] == X25_RR ||
frame[2] == X25_RNR ||
frame[2] == X25_REJ) {
*nr = (frame[3] >> 1) & 0x7F;
return frame[2];
}
} else {
if ((frame[2] & 0x1F) == X25_RR ||
(frame[2] & 0x1F) == X25_RNR ||
(frame[2] & 0x1F) == X25_REJ) {
*nr = (frame[2] >> 5) & 0x07;
return frame[2] & 0x1F;
}
}
if (x25->neighbour->extended) {
if ((frame[2] & 0x01) == X25_DATA) {
*q = (frame[0] & X25_Q_BIT) == X25_Q_BIT;
*d = (frame[0] & X25_D_BIT) == X25_D_BIT;
*m = (frame[3] & X25_EXT_M_BIT) == X25_EXT_M_BIT;
*nr = (frame[3] >> 1) & 0x7F;
*ns = (frame[2] >> 1) & 0x7F;
return X25_DATA;
}
} else {
if ((frame[2] & 0x01) == X25_DATA) {
*q = (frame[0] & X25_Q_BIT) == X25_Q_BIT;
*d = (frame[0] & X25_D_BIT) == X25_D_BIT;
*m = (frame[2] & X25_STD_M_BIT) == X25_STD_M_BIT;
*nr = (frame[2] >> 5) & 0x07;
*ns = (frame[2] >> 1) & 0x07;
return X25_DATA;
}
}
printk(KERN_DEBUG "X.25: invalid PLP frame %02X %02X %02X\n",
frame[0], frame[1], frame[2]);
return X25_ILLEGAL;
}
void x25_disconnect(struct sock *sk, int reason, unsigned char cause,
unsigned char diagnostic)
{
struct x25_sock *x25 = x25_sk(sk);
x25_clear_queues(sk);
x25_stop_timer(sk);
x25->lci = 0;
x25->state = X25_STATE_0;
x25->causediag.cause = cause;
x25->causediag.diagnostic = diagnostic;
sk->sk_state = TCP_CLOSE;
sk->sk_err = reason;
sk->sk_shutdown |= SEND_SHUTDOWN;
if (!sock_flag(sk, SOCK_DEAD)) {
sk->sk_state_change(sk);
sock_set_flag(sk, SOCK_DEAD);
}
}
/*
* Clear an own-rx-busy condition and tell the peer about this, provided
* that there is a significant amount of free receive buffer space available.
*/
void x25_check_rbuf(struct sock *sk)
{
struct x25_sock *x25 = x25_sk(sk);
if (atomic_read(&sk->sk_rmem_alloc) < (sk->sk_rcvbuf >> 1) &&
(x25->condition & X25_COND_OWN_RX_BUSY)) {
x25->condition &= ~X25_COND_OWN_RX_BUSY;
x25->condition &= ~X25_COND_ACK_PENDING;
x25->vl = x25->vr;
x25_write_internal(sk, X25_RR);
x25_stop_timer(sk);
}
}