diff options
Diffstat (limited to 'net/x25/x25_dev.c')
| -rw-r--r-- | net/x25/x25_dev.c | 207 |
1 files changed, 207 insertions, 0 deletions
diff --git a/net/x25/x25_dev.c b/net/x25/x25_dev.c new file mode 100644 index 000000000000..36fc3bf6d882 --- /dev/null +++ b/net/x25/x25_dev.c @@ -0,0 +1,207 @@ +/* + * 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. + * 2000-09-04 Henner Eisen Prevent freeing a dangling skb. + */ + +#include <linux/config.h> +#include <linux/kernel.h> +#include <linux/netdevice.h> +#include <linux/skbuff.h> +#include <net/sock.h> +#include <linux/if_arp.h> +#include <net/x25.h> + +static int x25_receive_data(struct sk_buff *skb, struct x25_neigh *nb) +{ + struct sock *sk; + unsigned short frametype; + unsigned int lci; + + frametype = skb->data[2]; + lci = ((skb->data[0] << 8) & 0xF00) + ((skb->data[1] << 0) & 0x0FF); + + /* + * LCI of zero is always for us, and its always a link control + * frame. + */ + if (lci == 0) { + x25_link_control(skb, nb, frametype); + return 0; + } + + /* + * Find an existing socket. + */ + if ((sk = x25_find_socket(lci, nb)) != NULL) { + int queued = 1; + + skb->h.raw = skb->data; + bh_lock_sock(sk); + if (!sock_owned_by_user(sk)) { + queued = x25_process_rx_frame(sk, skb); + } else { + sk_add_backlog(sk, skb); + } + bh_unlock_sock(sk); + return queued; + } + + /* + * Is is a Call Request ? if so process it. + */ + if (frametype == X25_CALL_REQUEST) + return x25_rx_call_request(skb, nb, lci); + + /* + * Its not a Call Request, nor is it a control frame. + * Let caller throw it away. + */ +/* + x25_transmit_clear_request(nb, lci, 0x0D); +*/ + + if (frametype != X25_CLEAR_CONFIRMATION) + printk(KERN_DEBUG "x25_receive_data(): unknown frame type %2x\n",frametype); + + return 0; +} + +int x25_lapb_receive_frame(struct sk_buff *skb, struct net_device *dev, + struct packet_type *ptype) +{ + struct sk_buff *nskb; + struct x25_neigh *nb; + + nskb = skb_copy(skb, GFP_ATOMIC); + if (!nskb) + goto drop; + kfree_skb(skb); + skb = nskb; + + /* + * Packet received from unrecognised device, throw it away. + */ + nb = x25_get_neigh(dev); + if (!nb) { + printk(KERN_DEBUG "X.25: unknown neighbour - %s\n", dev->name); + goto drop; + } + + switch (skb->data[0]) { + case 0x00: + skb_pull(skb, 1); + if (x25_receive_data(skb, nb)) { + x25_neigh_put(nb); + goto out; + } + break; + case 0x01: + x25_link_established(nb); + break; + case 0x02: + x25_link_terminated(nb); + break; + } + x25_neigh_put(nb); +drop: + kfree_skb(skb); +out: + return 0; +} + +void x25_establish_link(struct x25_neigh *nb) +{ + struct sk_buff *skb; + unsigned char *ptr; + + switch (nb->dev->type) { + case ARPHRD_X25: + if ((skb = alloc_skb(1, GFP_ATOMIC)) == NULL) { + printk(KERN_ERR "x25_dev: out of memory\n"); + return; + } + ptr = skb_put(skb, 1); + *ptr = 0x01; + break; + +#if defined(CONFIG_LLC) || defined(CONFIG_LLC_MODULE) + case ARPHRD_ETHER: + return; +#endif + default: + return; + } + + skb->protocol = htons(ETH_P_X25); + skb->dev = nb->dev; + + dev_queue_xmit(skb); +} + +void x25_terminate_link(struct x25_neigh *nb) +{ + struct sk_buff *skb; + unsigned char *ptr; + +#if defined(CONFIG_LLC) || defined(CONFIG_LLC_MODULE) + if (nb->dev->type == ARPHRD_ETHER) + return; +#endif + if (nb->dev->type != ARPHRD_X25) + return; + + skb = alloc_skb(1, GFP_ATOMIC); + if (!skb) { + printk(KERN_ERR "x25_dev: out of memory\n"); + return; + } + + ptr = skb_put(skb, 1); + *ptr = 0x02; + + skb->protocol = htons(ETH_P_X25); + skb->dev = nb->dev; + dev_queue_xmit(skb); +} + +void x25_send_frame(struct sk_buff *skb, struct x25_neigh *nb) +{ + unsigned char *dptr; + + skb->nh.raw = skb->data; + + switch (nb->dev->type) { + case ARPHRD_X25: + dptr = skb_push(skb, 1); + *dptr = 0x00; + break; + +#if defined(CONFIG_LLC) || defined(CONFIG_LLC_MODULE) + case ARPHRD_ETHER: + kfree_skb(skb); + return; +#endif + default: + kfree_skb(skb); + return; + } + + skb->protocol = htons(ETH_P_X25); + skb->dev = nb->dev; + + dev_queue_xmit(skb); +} |