Release 4.15 net/x25/x25_subr.c

/*
 *      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
 *      apr/04/15       Shaun Pereira           Fast select with no
 *                                              restriction on response.
 */


#define pr_fmt(fmt) "X25: " fmt

#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);
}


Contributors
Person
Tokens
Prop
Commits
CommitProp
Linus Torvalds (pre-git)
44
73.33%
3
37.50%
David S. Miller
8
13.33%
1
12.50%
Linus Torvalds
5
8.33%
1
12.50%
Arnaldo Carvalho de Melo
3
5.00%
3
37.50%
Total
60
100.00%
8
100.00%

/*
 * 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;
		}
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Linus Torvalds (pre-git)
86
87.76%
1
20.00%
David S. Miller
8
8.16%
1
20.00%
Arnaldo Carvalho de Melo
2
2.04%
2
40.00%
Linus Torvalds
2
2.04%
1
20.00%
Total
98
100.00%
5
100.00%



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;
	}
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Linus Torvalds (pre-git)
64
86.49%
1
20.00%
David S. Miller
8
10.81%
2
40.00%
Arnaldo Carvalho de Melo
2
2.70%
2
40.00%
Total
74
100.00%
5
100.00%

/*
 *      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;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Linus Torvalds (pre-git)
70
82.35%
1
20.00%
David S. Miller
8
9.41%
1
20.00%
Linus Torvalds
5
5.88%
1
20.00%
Arnaldo Carvalho de Melo
2
2.35%
2
40.00%
Total
85
100.00%
5
100.00%

/*
 *  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:
		pr_err("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);
			skb_put_data(skb, addresses, len);
			len     = x25_create_facilities(facilities,
					&x25->facilities,
					&x25->dte_facilities,
					x25->neighbour->global_facil_mask);
			skb_put_data(skb, facilities, len);
			skb_put_data(skb, 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->dte_facilities,
							x25->vc_facil_mask);
			skb_put_data(skb, facilities, len);

			/* 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) {
				skb_put_data(skb,
					     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);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Linus Torvalds (pre-git)
543
84.32%
3
25.00%
Shaun Pereira
45
6.99%
2
16.67%
Andrew Hendry
36
5.59%
1
8.33%
David S. Miller
8
1.24%
1
8.33%
Arnaldo Carvalho de Melo
5
0.78%
3
25.00%
Johannes Berg
5
0.78%
1
8.33%
Wang Weidong
2
0.31%
1
8.33%
Total
644
100.00%
12
100.00%

/*
 *      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;

	if (!pskb_may_pull(skb, X25_STD_MIN_LEN))
		return X25_ILLEGAL;
	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) {
			if (!pskb_may_pull(skb, X25_EXT_MIN_LEN))
				return X25_ILLEGAL;
			frame = skb->data;

			*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) {
			if (!pskb_may_pull(skb, X25_EXT_MIN_LEN))
				return X25_ILLEGAL;
			frame = skb->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;
		}
	}

	pr_debug("invalid PLP frame %02X %02X %02X\n",
	       frame[0], frame[1], frame[2]);

	return X25_ILLEGAL;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Linus Torvalds (pre-git)
440
86.79%
1
16.67%
Matthew Daley
55
10.85%
1
16.67%
David S. Miller
8
1.58%
1
16.67%
Arnaldo Carvalho de Melo
2
0.39%
2
33.33%
Wang Weidong
2
0.39%
1
16.67%
Total
507
100.00%
6
100.00%



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);
	}
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Linus Torvalds (pre-git)
87
76.99%
1
14.29%
Arnaldo Carvalho de Melo
14
12.39%
4
57.14%
David S. Miller
8
7.08%
1
14.29%
James Morris
4
3.54%
1
14.29%
Total
113
100.00%
7
100.00%

/*
 * 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);
	}
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Linus Torvalds
68
82.93%
1
16.67%
David S. Miller
8
9.76%
1
16.67%
Arnaldo Carvalho de Melo
4
4.88%
3
50.00%
Eric Dumazet
2
2.44%
1
16.67%
Total
82
100.00%
6
100.00%

Overall Contributors
Person
Tokens
Prop
Commits
CommitProp
Linus Torvalds (pre-git)
1353
79.68%
5
20.83%
Linus Torvalds
81
4.77%
2
8.33%
David S. Miller
66
3.89%
2
8.33%
Matthew Daley
55
3.24%
1
4.17%
Shaun Pereira
46
2.71%
2
8.33%
Arnaldo Carvalho de Melo
36
2.12%
6
25.00%
Andrew Hendry
36
2.12%
1
4.17%
Wang Weidong
11
0.65%
1
4.17%
Johannes Berg
5
0.29%
1
4.17%
James Morris
4
0.24%
1
4.17%
Tejun Heo
3
0.18%
1
4.17%
Eric Dumazet
2
0.12%
1
4.17%
Total
1698
100.00%
24
100.00%
Directory: net/x25

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