diff options
Diffstat (limited to 'net/netrom/nr_out.c')
| -rw-r--r-- | net/netrom/nr_out.c | 243 |
1 files changed, 243 insertions, 0 deletions
diff --git a/net/netrom/nr_out.c b/net/netrom/nr_out.c new file mode 100644 index 000000000..2ebdd743d --- /dev/null +++ b/net/netrom/nr_out.c @@ -0,0 +1,243 @@ +/* + * NET/ROM 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 1.2.1 or higher/ NET3.029 + * + * 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 + * NET/ROM 001 Jonathan(G4KLX) Cloned from ax25_out.c + */ + +#include <linux/config.h> +#ifdef CONFIG_NETROM +#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 <asm/segment.h> +#include <asm/system.h> +#include <linux/fcntl.h> +#include <linux/mm.h> +#include <linux/interrupt.h> +#include <net/netrom.h> + +int nr_output(struct sock *sk, struct sk_buff *skb) +{ + skb_queue_tail(&sk->write_queue, skb); /* Throw it on the queue */ + + if (sk->nr->state == NR_STATE_3) + nr_kick(sk); + + return 0; +} + +/* + * This procedure is passed a buffer descriptor for an iframe. It builds + * the rest of the control part of the frame and then writes it out. + */ +static void nr_send_iframe(struct sock *sk, struct sk_buff *skb) +{ + unsigned char *dptr; + + if (skb == NULL) + return; + + dptr = skb->data + 34; + + *dptr++ = sk->nr->vs; + *dptr++ = sk->nr->vr; + + nr_transmit_buffer(sk, skb); +} + +void nr_send_nak_frame(struct sock *sk) +{ + struct sk_buff *skb, *skbn; + + if ((skb = skb_peek(&sk->nr->ack_queue)) == NULL) + return; + + if ((skbn = skb_clone(skb, GFP_ATOMIC)) == NULL) + return; + + nr_send_iframe(sk, skbn); + + sk->nr->condition &= ~ACK_PENDING_CONDITION; + sk->nr->vl = sk->nr->vr; + sk->nr->t1timer = 0; +} + +void nr_kick(struct sock *sk) +{ + struct sk_buff *skb, *skbn; + int last = 1; + unsigned short start, end, next; + + del_timer(&sk->timer); + + start = (skb_peek(&sk->nr->ack_queue) == NULL) ? sk->nr->va : sk->nr->vs; + end = (sk->nr->va + sk->window) % NR_MODULUS; + + if (!(sk->nr->condition & PEER_RX_BUSY_CONDITION) && + start != end && + skb_peek(&sk->write_queue) != NULL) { + + sk->nr->vs = start; + + /* + * Transmit data until either we're out of data to send or + * the window is full. + */ + do { + /* + * Dequeue the frame and copy it. + */ + skb = skb_dequeue(&sk->write_queue); + + if ((skbn = skb_clone(skb, GFP_ATOMIC)) == NULL) { + skb_queue_head(&sk->write_queue, skb); + return; + } + + next = (sk->nr->vs + 1) % NR_MODULUS; + last = (next == end); + + /* + * Transmit the frame copy. + */ + nr_send_iframe(sk, skbn); + + sk->nr->vs = next; + + /* + * Requeue the original data frame. + */ + skb_queue_tail(&sk->nr->ack_queue, skb); + + } while (!last && skb_peek(&sk->write_queue) != NULL); + + sk->nr->vl = sk->nr->vr; + sk->nr->condition &= ~ACK_PENDING_CONDITION; + + if (sk->nr->t1timer == 0) { + sk->nr->t1timer = sk->nr->t1 = nr_calculate_t1(sk); + } + } + + nr_set_timer(sk); +} + +void nr_transmit_buffer(struct sock *sk, struct sk_buff *skb) +{ + unsigned char *dptr; + + dptr = skb->data + 16; + + *dptr++ = AX25_P_NETROM; + + memcpy(dptr, &sk->nr->source_addr, sizeof(ax25_address)); + dptr[6] &= ~LAPB_C; + dptr[6] &= ~LAPB_E; + dptr[6] |= SSID_SPARE; + dptr += 7; + + memcpy(dptr, &sk->nr->dest_addr, sizeof(ax25_address)); + dptr[6] &= ~LAPB_C; + dptr[6] |= LAPB_E; + dptr[6] |= SSID_SPARE; + dptr += 7; + + *dptr++ = nr_default.ttl; + + skb->arp = 1; + + if (!nr_route_frame(skb, NULL)) { + kfree_skb(skb, FREE_WRITE); + + sk->state = TCP_CLOSE; + sk->err = ENETUNREACH; + if (!sk->dead) + sk->state_change(sk); + sk->dead = 1; + } +} + +/* + * The following routines are taken from page 170 of the 7th ARRL Computer + * Networking Conference paper, as is the whole state machine. + */ + +void nr_nr_error_recovery(struct sock *sk) +{ + nr_establish_data_link(sk); +} + +void nr_establish_data_link(struct sock *sk) +{ + sk->nr->condition = 0x00; + sk->nr->n2count = 0; + + nr_write_internal(sk, NR_CONNREQ); + + sk->nr->t2timer = 0; + sk->nr->t1timer = sk->nr->t1 = nr_calculate_t1(sk); +} + +/* + * Never send a NAK when we are CHOKEd. + */ +void nr_enquiry_response(struct sock *sk) +{ + int frametype = NR_INFOACK; + + if (sk->nr->condition & OWN_RX_BUSY_CONDITION) { + frametype += NR_CHOKE_FLAG; + } else { + if (skb_peek(&sk->nr->reseq_queue) != NULL) { + frametype += NR_NAK_FLAG; + } + } + + nr_write_internal(sk, frametype); + + sk->nr->vl = sk->nr->vr; + sk->nr->condition &= ~ACK_PENDING_CONDITION; +} + +void nr_check_iframes_acked(struct sock *sk, unsigned short nr) +{ + if (sk->nr->vs == nr) { + nr_frames_acked(sk, nr); + nr_requeue_frames(sk); + nr_calculate_rtt(sk); + sk->nr->t1timer = 0; + sk->nr->n2count = 0; + } else { + if (sk->nr->va != nr) { + nr_frames_acked(sk, nr); + nr_requeue_frames(sk); + sk->nr->t1timer = sk->nr->t1 = nr_calculate_t1(sk); + } + } +} + +#endif |