diff options
Diffstat (limited to 'net/netrom/nr_subr.c')
| -rw-r--r-- | net/netrom/nr_subr.c | 283 |
1 files changed, 283 insertions, 0 deletions
diff --git a/net/netrom/nr_subr.c b/net/netrom/nr_subr.c new file mode 100644 index 000000000000..0627347b14b8 --- /dev/null +++ b/net/netrom/nr_subr.c @@ -0,0 +1,283 @@ +/* + * This program 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. + * + * Copyright Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk) + */ +#include <linux/errno.h> +#include <linux/types.h> +#include <linux/socket.h> +#include <linux/in.h> +#include <linux/kernel.h> +#include <linux/sched.h> +#include <linux/timer.h> +#include <linux/string.h> +#include <linux/sockios.h> +#include <linux/net.h> +#include <net/ax25.h> +#include <linux/inet.h> +#include <linux/netdevice.h> +#include <linux/skbuff.h> +#include <net/sock.h> +#include <net/tcp.h> +#include <asm/uaccess.h> +#include <asm/system.h> +#include <linux/fcntl.h> +#include <linux/mm.h> +#include <linux/interrupt.h> +#include <net/netrom.h> + +/* + * This routine purges all of the queues of frames. + */ +void nr_clear_queues(struct sock *sk) +{ + struct nr_sock *nr = nr_sk(sk); + + skb_queue_purge(&sk->sk_write_queue); + skb_queue_purge(&nr->ack_queue); + skb_queue_purge(&nr->reseq_queue); + skb_queue_purge(&nr->frag_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 nr_frames_acked(struct sock *sk, unsigned short nr) +{ + struct nr_sock *nrom = nr_sk(sk); + struct sk_buff *skb; + + /* + * Remove all the ack-ed frames from the ack queue. + */ + if (nrom->va != nr) { + while (skb_peek(&nrom->ack_queue) != NULL && nrom->va != nr) { + skb = skb_dequeue(&nrom->ack_queue); + kfree_skb(skb); + nrom->va = (nrom->va + 1) % NR_MODULUS; + } + } +} + +/* + * Requeue all the un-ack-ed frames on the output queue to be picked + * up by nr_kick called from the timer. This arrangement handles the + * possibility of an empty output queue. + */ +void nr_requeue_frames(struct sock *sk) +{ + struct sk_buff *skb, *skb_prev = NULL; + + while ((skb = skb_dequeue(&nr_sk(sk)->ack_queue)) != NULL) { + if (skb_prev == NULL) + skb_queue_head(&sk->sk_write_queue, skb); + else + skb_append(skb_prev, skb); + skb_prev = skb; + } +} + +/* + * Validate that the value of nr is between va and vs. Return true or + * false for testing. + */ +int nr_validate_nr(struct sock *sk, unsigned short nr) +{ + struct nr_sock *nrom = nr_sk(sk); + unsigned short vc = nrom->va; + + while (vc != nrom->vs) { + if (nr == vc) return 1; + vc = (vc + 1) % NR_MODULUS; + } + + return nr == nrom->vs; +} + +/* + * Check that ns is within the receive window. + */ +int nr_in_rx_window(struct sock *sk, unsigned short ns) +{ + struct nr_sock *nr = nr_sk(sk); + unsigned short vc = nr->vr; + unsigned short vt = (nr->vl + nr->window) % NR_MODULUS; + + while (vc != vt) { + if (ns == vc) return 1; + vc = (vc + 1) % NR_MODULUS; + } + + return 0; +} + +/* + * This routine is called when the HDLC layer internally generates a + * control frame. + */ +void nr_write_internal(struct sock *sk, int frametype) +{ + struct nr_sock *nr = nr_sk(sk); + struct sk_buff *skb; + unsigned char *dptr; + int len, timeout; + + len = NR_NETWORK_LEN + NR_TRANSPORT_LEN; + + switch (frametype & 0x0F) { + case NR_CONNREQ: + len += 17; + break; + case NR_CONNACK: + len += (nr->bpqext) ? 2 : 1; + break; + case NR_DISCREQ: + case NR_DISCACK: + case NR_INFOACK: + break; + default: + printk(KERN_ERR "NET/ROM: nr_write_internal - invalid frame type %d\n", frametype); + return; + } + + if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL) + return; + + /* + * Space for AX.25 and NET/ROM network header + */ + skb_reserve(skb, NR_NETWORK_LEN); + + dptr = skb_put(skb, skb_tailroom(skb)); + + switch (frametype & 0x0F) { + case NR_CONNREQ: + timeout = nr->t1 / HZ; + *dptr++ = nr->my_index; + *dptr++ = nr->my_id; + *dptr++ = 0; + *dptr++ = 0; + *dptr++ = frametype; + *dptr++ = nr->window; + memcpy(dptr, &nr->user_addr, AX25_ADDR_LEN); + dptr[6] &= ~AX25_CBIT; + dptr[6] &= ~AX25_EBIT; + dptr[6] |= AX25_SSSID_SPARE; + dptr += AX25_ADDR_LEN; + memcpy(dptr, &nr->source_addr, AX25_ADDR_LEN); + dptr[6] &= ~AX25_CBIT; + dptr[6] &= ~AX25_EBIT; + dptr[6] |= AX25_SSSID_SPARE; + dptr += AX25_ADDR_LEN; + *dptr++ = timeout % 256; + *dptr++ = timeout / 256; + break; + + case NR_CONNACK: + *dptr++ = nr->your_index; + *dptr++ = nr->your_id; + *dptr++ = nr->my_index; + *dptr++ = nr->my_id; + *dptr++ = frametype; + *dptr++ = nr->window; + if (nr->bpqext) *dptr++ = sysctl_netrom_network_ttl_initialiser; + break; + + case NR_DISCREQ: + case NR_DISCACK: + *dptr++ = nr->your_index; + *dptr++ = nr->your_id; + *dptr++ = 0; + *dptr++ = 0; + *dptr++ = frametype; + break; + + case NR_INFOACK: + *dptr++ = nr->your_index; + *dptr++ = nr->your_id; + *dptr++ = 0; + *dptr++ = nr->vr; + *dptr++ = frametype; + break; + } + + nr_transmit_buffer(sk, skb); +} + +/* + * This routine is called when a Connect Acknowledge with the Choke Flag + * set is needed to refuse a connection. + */ +void nr_transmit_refusal(struct sk_buff *skb, int mine) +{ + struct sk_buff *skbn; + unsigned char *dptr; + int len; + + len = NR_NETWORK_LEN + NR_TRANSPORT_LEN + 1; + + if ((skbn = alloc_skb(len, GFP_ATOMIC)) == NULL) + return; + + skb_reserve(skbn, 0); + + dptr = skb_put(skbn, NR_NETWORK_LEN + NR_TRANSPORT_LEN); + + memcpy(dptr, skb->data + 7, AX25_ADDR_LEN); + dptr[6] &= ~AX25_CBIT; + dptr[6] &= ~AX25_EBIT; + dptr[6] |= AX25_SSSID_SPARE; + dptr += AX25_ADDR_LEN; + + memcpy(dptr, skb->data + 0, AX25_ADDR_LEN); + dptr[6] &= ~AX25_CBIT; + dptr[6] |= AX25_EBIT; + dptr[6] |= AX25_SSSID_SPARE; + dptr += AX25_ADDR_LEN; + + *dptr++ = sysctl_netrom_network_ttl_initialiser; + + if (mine) { + *dptr++ = 0; + *dptr++ = 0; + *dptr++ = skb->data[15]; + *dptr++ = skb->data[16]; + } else { + *dptr++ = skb->data[15]; + *dptr++ = skb->data[16]; + *dptr++ = 0; + *dptr++ = 0; + } + + *dptr++ = NR_CONNACK | NR_CHOKE_FLAG; + *dptr++ = 0; + + if (!nr_route_frame(skbn, NULL)) + kfree_skb(skbn); +} + +void nr_disconnect(struct sock *sk, int reason) +{ + nr_stop_t1timer(sk); + nr_stop_t2timer(sk); + nr_stop_t4timer(sk); + nr_stop_idletimer(sk); + + nr_clear_queues(sk); + + nr_sk(sk)->state = NR_STATE_0; + + 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); + } +} |