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v4.6
 
  1/*
  2 *	X.25 Packet Layer release 002
  3 *
  4 *	This is ALPHA test software. This code may break your machine, randomly fail to work with new
  5 *	releases, misbehave and/or generally screw up. It might even work.
  6 *
  7 *	This code REQUIRES 2.1.15 or higher
  8 *
  9 *	This module:
 10 *		This module is free software; you can redistribute it and/or
 11 *		modify it under the terms of the GNU General Public License
 12 *		as published by the Free Software Foundation; either version
 13 *		2 of the License, or (at your option) any later version.
 14 *
 15 *	History
 16 *	X.25 001	Jonathan Naylor	Started coding.
 17 *      2000-09-04	Henner Eisen	Prevent freeing a dangling skb.
 18 */
 19
 20#define pr_fmt(fmt) "X25: " fmt
 21
 22#include <linux/kernel.h>
 23#include <linux/netdevice.h>
 24#include <linux/skbuff.h>
 25#include <linux/slab.h>
 26#include <net/sock.h>
 27#include <linux/if_arp.h>
 28#include <net/x25.h>
 29#include <net/x25device.h>
 30
 31static int x25_receive_data(struct sk_buff *skb, struct x25_neigh *nb)
 32{
 33	struct sock *sk;
 34	unsigned short frametype;
 35	unsigned int lci;
 36
 37	if (!pskb_may_pull(skb, X25_STD_MIN_LEN))
 38		return 0;
 39
 40	frametype = skb->data[2];
 41	lci = ((skb->data[0] << 8) & 0xF00) + ((skb->data[1] << 0) & 0x0FF);
 42
 43	/*
 44	 *	LCI of zero is always for us, and its always a link control
 45	 *	frame.
 46	 */
 47	if (lci == 0) {
 48		x25_link_control(skb, nb, frametype);
 49		return 0;
 50	}
 51
 52	/*
 53	 *	Find an existing socket.
 54	 */
 55	if ((sk = x25_find_socket(lci, nb)) != NULL) {
 56		int queued = 1;
 57
 58		skb_reset_transport_header(skb);
 59		bh_lock_sock(sk);
 60		if (!sock_owned_by_user(sk)) {
 61			queued = x25_process_rx_frame(sk, skb);
 62		} else {
 63			queued = !sk_add_backlog(sk, skb, sk->sk_rcvbuf);
 64		}
 65		bh_unlock_sock(sk);
 66		sock_put(sk);
 67		return queued;
 68	}
 69
 70	/*
 71	 *	Is is a Call Request ? if so process it.
 72	 */
 73	if (frametype == X25_CALL_REQUEST)
 74		return x25_rx_call_request(skb, nb, lci);
 75
 76	/*
 77	 * 	Its not a Call Request, nor is it a control frame.
 78	 *	Can we forward it?
 79	 */
 80
 81	if (x25_forward_data(lci, nb, skb)) {
 82		if (frametype == X25_CLEAR_CONFIRMATION) {
 83			x25_clear_forward_by_lci(lci);
 84		}
 85		kfree_skb(skb);
 86		return 1;
 87	}
 88
 89/*
 90	x25_transmit_clear_request(nb, lci, 0x0D);
 91*/
 92
 93	if (frametype != X25_CLEAR_CONFIRMATION)
 94		pr_debug("x25_receive_data(): unknown frame type %2x\n",frametype);
 95
 96	return 0;
 97}
 98
 99int x25_lapb_receive_frame(struct sk_buff *skb, struct net_device *dev,
100			   struct packet_type *ptype, struct net_device *orig_dev)
101{
102	struct sk_buff *nskb;
103	struct x25_neigh *nb;
104
105	if (!net_eq(dev_net(dev), &init_net))
106		goto drop;
107
108	nskb = skb_copy(skb, GFP_ATOMIC);
109	if (!nskb)
110		goto drop;
111	kfree_skb(skb);
112	skb = nskb;
113
114	/*
115	 * Packet received from unrecognised device, throw it away.
116	 */
117	nb = x25_get_neigh(dev);
118	if (!nb) {
119		pr_debug("unknown neighbour - %s\n", dev->name);
120		goto drop;
121	}
122
123	if (!pskb_may_pull(skb, 1))
124		return 0;
 
 
125
126	switch (skb->data[0]) {
127
128	case X25_IFACE_DATA:
129		skb_pull(skb, 1);
130		if (x25_receive_data(skb, nb)) {
131			x25_neigh_put(nb);
132			goto out;
133		}
134		break;
135
136	case X25_IFACE_CONNECT:
137		x25_link_established(nb);
138		break;
139
140	case X25_IFACE_DISCONNECT:
141		x25_link_terminated(nb);
142		break;
143	}
144	x25_neigh_put(nb);
145drop:
146	kfree_skb(skb);
147out:
148	return 0;
149}
150
151void x25_establish_link(struct x25_neigh *nb)
152{
153	struct sk_buff *skb;
154	unsigned char *ptr;
155
156	switch (nb->dev->type) {
157	case ARPHRD_X25:
158		if ((skb = alloc_skb(1, GFP_ATOMIC)) == NULL) {
159			pr_err("x25_dev: out of memory\n");
160			return;
161		}
162		ptr  = skb_put(skb, 1);
163		*ptr = X25_IFACE_CONNECT;
164		break;
165
166#if IS_ENABLED(CONFIG_LLC)
167	case ARPHRD_ETHER:
168		return;
169#endif
170	default:
171		return;
172	}
173
174	skb->protocol = htons(ETH_P_X25);
175	skb->dev      = nb->dev;
176
177	dev_queue_xmit(skb);
178}
179
180void x25_terminate_link(struct x25_neigh *nb)
181{
182	struct sk_buff *skb;
183	unsigned char *ptr;
184
185#if IS_ENABLED(CONFIG_LLC)
186	if (nb->dev->type == ARPHRD_ETHER)
187		return;
188#endif
189	if (nb->dev->type != ARPHRD_X25)
190		return;
191
192	skb = alloc_skb(1, GFP_ATOMIC);
193	if (!skb) {
194		pr_err("x25_dev: out of memory\n");
195		return;
196	}
197
198	ptr  = skb_put(skb, 1);
199	*ptr = X25_IFACE_DISCONNECT;
200
201	skb->protocol = htons(ETH_P_X25);
202	skb->dev      = nb->dev;
203	dev_queue_xmit(skb);
204}
205
206void x25_send_frame(struct sk_buff *skb, struct x25_neigh *nb)
207{
208	unsigned char *dptr;
209
210	skb_reset_network_header(skb);
211
212	switch (nb->dev->type) {
213	case ARPHRD_X25:
214		dptr  = skb_push(skb, 1);
215		*dptr = X25_IFACE_DATA;
216		break;
217
218#if IS_ENABLED(CONFIG_LLC)
219	case ARPHRD_ETHER:
220		kfree_skb(skb);
221		return;
222#endif
223	default:
224		kfree_skb(skb);
225		return;
226	}
227
228	skb->protocol = htons(ETH_P_X25);
229	skb->dev      = nb->dev;
230
231	dev_queue_xmit(skb);
232}
v6.13.7
  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 *	X.25 Packet Layer release 002
  4 *
  5 *	This is ALPHA test software. This code may break your machine, randomly fail to work with new
  6 *	releases, misbehave and/or generally screw up. It might even work.
  7 *
  8 *	This code REQUIRES 2.1.15 or higher
  9 *
 
 
 
 
 
 
 10 *	History
 11 *	X.25 001	Jonathan Naylor	Started coding.
 12 *      2000-09-04	Henner Eisen	Prevent freeing a dangling skb.
 13 */
 14
 15#define pr_fmt(fmt) "X25: " fmt
 16
 17#include <linux/kernel.h>
 18#include <linux/netdevice.h>
 19#include <linux/skbuff.h>
 20#include <linux/slab.h>
 21#include <net/sock.h>
 22#include <linux/if_arp.h>
 23#include <net/x25.h>
 24#include <net/x25device.h>
 25
 26static int x25_receive_data(struct sk_buff *skb, struct x25_neigh *nb)
 27{
 28	struct sock *sk;
 29	unsigned short frametype;
 30	unsigned int lci;
 31
 32	if (!pskb_may_pull(skb, X25_STD_MIN_LEN))
 33		return 0;
 34
 35	frametype = skb->data[2];
 36	lci = ((skb->data[0] << 8) & 0xF00) + ((skb->data[1] << 0) & 0x0FF);
 37
 38	/*
 39	 *	LCI of zero is always for us, and its always a link control
 40	 *	frame.
 41	 */
 42	if (lci == 0) {
 43		x25_link_control(skb, nb, frametype);
 44		return 0;
 45	}
 46
 47	/*
 48	 *	Find an existing socket.
 49	 */
 50	if ((sk = x25_find_socket(lci, nb)) != NULL) {
 51		int queued = 1;
 52
 53		skb_reset_transport_header(skb);
 54		bh_lock_sock(sk);
 55		if (!sock_owned_by_user(sk)) {
 56			queued = x25_process_rx_frame(sk, skb);
 57		} else {
 58			queued = !sk_add_backlog(sk, skb, READ_ONCE(sk->sk_rcvbuf));
 59		}
 60		bh_unlock_sock(sk);
 61		sock_put(sk);
 62		return queued;
 63	}
 64
 65	/*
 66	 *	Is is a Call Request ? if so process it.
 67	 */
 68	if (frametype == X25_CALL_REQUEST)
 69		return x25_rx_call_request(skb, nb, lci);
 70
 71	/*
 72	 * 	Its not a Call Request, nor is it a control frame.
 73	 *	Can we forward it?
 74	 */
 75
 76	if (x25_forward_data(lci, nb, skb)) {
 77		if (frametype == X25_CLEAR_CONFIRMATION) {
 78			x25_clear_forward_by_lci(lci);
 79		}
 80		kfree_skb(skb);
 81		return 1;
 82	}
 83
 84/*
 85	x25_transmit_clear_request(nb, lci, 0x0D);
 86*/
 87
 88	if (frametype != X25_CLEAR_CONFIRMATION)
 89		pr_debug("x25_receive_data(): unknown frame type %2x\n",frametype);
 90
 91	return 0;
 92}
 93
 94int x25_lapb_receive_frame(struct sk_buff *skb, struct net_device *dev,
 95			   struct packet_type *ptype, struct net_device *orig_dev)
 96{
 97	struct sk_buff *nskb;
 98	struct x25_neigh *nb;
 99
100	if (!net_eq(dev_net(dev), &init_net))
101		goto drop;
102
103	nskb = skb_copy(skb, GFP_ATOMIC);
104	if (!nskb)
105		goto drop;
106	kfree_skb(skb);
107	skb = nskb;
108
109	/*
110	 * Packet received from unrecognised device, throw it away.
111	 */
112	nb = x25_get_neigh(dev);
113	if (!nb) {
114		pr_debug("unknown neighbour - %s\n", dev->name);
115		goto drop;
116	}
117
118	if (!pskb_may_pull(skb, 1)) {
119		x25_neigh_put(nb);
120		goto drop;
121	}
122
123	switch (skb->data[0]) {
124
125	case X25_IFACE_DATA:
126		skb_pull(skb, 1);
127		if (x25_receive_data(skb, nb)) {
128			x25_neigh_put(nb);
129			goto out;
130		}
131		break;
132
133	case X25_IFACE_CONNECT:
134		x25_link_established(nb);
135		break;
136
137	case X25_IFACE_DISCONNECT:
138		x25_link_terminated(nb);
139		break;
140	}
141	x25_neigh_put(nb);
142drop:
143	kfree_skb(skb);
144out:
145	return 0;
146}
147
148void x25_establish_link(struct x25_neigh *nb)
149{
150	struct sk_buff *skb;
151	unsigned char *ptr;
152
153	switch (nb->dev->type) {
154	case ARPHRD_X25:
155		if ((skb = alloc_skb(1, GFP_ATOMIC)) == NULL) {
156			pr_err("x25_dev: out of memory\n");
157			return;
158		}
159		ptr  = skb_put(skb, 1);
160		*ptr = X25_IFACE_CONNECT;
161		break;
162
 
 
 
 
163	default:
164		return;
165	}
166
167	skb->protocol = htons(ETH_P_X25);
168	skb->dev      = nb->dev;
169
170	dev_queue_xmit(skb);
171}
172
173void x25_terminate_link(struct x25_neigh *nb)
174{
175	struct sk_buff *skb;
176	unsigned char *ptr;
177
 
 
 
 
178	if (nb->dev->type != ARPHRD_X25)
179		return;
180
181	skb = alloc_skb(1, GFP_ATOMIC);
182	if (!skb) {
183		pr_err("x25_dev: out of memory\n");
184		return;
185	}
186
187	ptr  = skb_put(skb, 1);
188	*ptr = X25_IFACE_DISCONNECT;
189
190	skb->protocol = htons(ETH_P_X25);
191	skb->dev      = nb->dev;
192	dev_queue_xmit(skb);
193}
194
195void x25_send_frame(struct sk_buff *skb, struct x25_neigh *nb)
196{
197	unsigned char *dptr;
198
199	skb_reset_network_header(skb);
200
201	switch (nb->dev->type) {
202	case ARPHRD_X25:
203		dptr  = skb_push(skb, 1);
204		*dptr = X25_IFACE_DATA;
205		break;
206
 
 
 
 
 
207	default:
208		kfree_skb(skb);
209		return;
210	}
211
212	skb->protocol = htons(ETH_P_X25);
213	skb->dev      = nb->dev;
214
215	dev_queue_xmit(skb);
216}