diff options
Diffstat (limited to 'net/netrom/nr_in.c')
| -rw-r--r-- | net/netrom/nr_in.c | 290 |
1 files changed, 290 insertions, 0 deletions
diff --git a/net/netrom/nr_in.c b/net/netrom/nr_in.c new file mode 100644 index 000000000000..9c44b3794126 --- /dev/null +++ b/net/netrom/nr_in.c @@ -0,0 +1,290 @@ +/* + * 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) + * Copyright Darryl Miles G7LED (dlm@g7led.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 <net/ip.h> /* For ip_rcv */ +#include <asm/uaccess.h> +#include <asm/system.h> +#include <linux/fcntl.h> +#include <linux/mm.h> +#include <linux/interrupt.h> +#include <net/netrom.h> + +static int nr_queue_rx_frame(struct sock *sk, struct sk_buff *skb, int more) +{ + struct sk_buff *skbo, *skbn = skb; + struct nr_sock *nr = nr_sk(sk); + + skb_pull(skb, NR_NETWORK_LEN + NR_TRANSPORT_LEN); + + nr_start_idletimer(sk); + + if (more) { + nr->fraglen += skb->len; + skb_queue_tail(&nr->frag_queue, skb); + return 0; + } + + if (!more && nr->fraglen > 0) { /* End of fragment */ + nr->fraglen += skb->len; + skb_queue_tail(&nr->frag_queue, skb); + + if ((skbn = alloc_skb(nr->fraglen, GFP_ATOMIC)) == NULL) + return 1; + + skbn->h.raw = skbn->data; + + while ((skbo = skb_dequeue(&nr->frag_queue)) != NULL) { + memcpy(skb_put(skbn, skbo->len), skbo->data, skbo->len); + kfree_skb(skbo); + } + + nr->fraglen = 0; + } + + return sock_queue_rcv_skb(sk, skbn); +} + +/* + * State machine for state 1, Awaiting Connection State. + * The handling of the timer(s) is in file nr_timer.c. + * Handling of state 0 and connection release is in netrom.c. + */ +static int nr_state1_machine(struct sock *sk, struct sk_buff *skb, + int frametype) +{ + switch (frametype) { + case NR_CONNACK: { + struct nr_sock *nr = nr_sk(sk); + + nr_stop_t1timer(sk); + nr_start_idletimer(sk); + nr->your_index = skb->data[17]; + nr->your_id = skb->data[18]; + nr->vs = 0; + nr->va = 0; + nr->vr = 0; + nr->vl = 0; + nr->state = NR_STATE_3; + nr->n2count = 0; + nr->window = skb->data[20]; + sk->sk_state = TCP_ESTABLISHED; + if (!sock_flag(sk, SOCK_DEAD)) + sk->sk_state_change(sk); + break; + } + + case NR_CONNACK | NR_CHOKE_FLAG: + nr_disconnect(sk, ECONNREFUSED); + break; + + default: + break; + } + return 0; +} + +/* + * State machine for state 2, Awaiting Release State. + * The handling of the timer(s) is in file nr_timer.c + * Handling of state 0 and connection release is in netrom.c. + */ +static int nr_state2_machine(struct sock *sk, struct sk_buff *skb, + int frametype) +{ + switch (frametype) { + case NR_CONNACK | NR_CHOKE_FLAG: + nr_disconnect(sk, ECONNRESET); + break; + + case NR_DISCREQ: + nr_write_internal(sk, NR_DISCACK); + + case NR_DISCACK: + nr_disconnect(sk, 0); + break; + + default: + break; + } + return 0; +} + +/* + * State machine for state 3, Connected State. + * The handling of the timer(s) is in file nr_timer.c + * Handling of state 0 and connection release is in netrom.c. + */ +static int nr_state3_machine(struct sock *sk, struct sk_buff *skb, int frametype) +{ + struct nr_sock *nrom = nr_sk(sk); + struct sk_buff_head temp_queue; + struct sk_buff *skbn; + unsigned short save_vr; + unsigned short nr, ns; + int queued = 0; + + nr = skb->data[18]; + ns = skb->data[17]; + + switch (frametype) { + case NR_CONNREQ: + nr_write_internal(sk, NR_CONNACK); + break; + + case NR_DISCREQ: + nr_write_internal(sk, NR_DISCACK); + nr_disconnect(sk, 0); + break; + + case NR_CONNACK | NR_CHOKE_FLAG: + case NR_DISCACK: + nr_disconnect(sk, ECONNRESET); + break; + + case NR_INFOACK: + case NR_INFOACK | NR_CHOKE_FLAG: + case NR_INFOACK | NR_NAK_FLAG: + case NR_INFOACK | NR_NAK_FLAG | NR_CHOKE_FLAG: + if (frametype & NR_CHOKE_FLAG) { + nrom->condition |= NR_COND_PEER_RX_BUSY; + nr_start_t4timer(sk); + } else { + nrom->condition &= ~NR_COND_PEER_RX_BUSY; + nr_stop_t4timer(sk); + } + if (!nr_validate_nr(sk, nr)) { + break; + } + if (frametype & NR_NAK_FLAG) { + nr_frames_acked(sk, nr); + nr_send_nak_frame(sk); + } else { + if (nrom->condition & NR_COND_PEER_RX_BUSY) { + nr_frames_acked(sk, nr); + } else { + nr_check_iframes_acked(sk, nr); + } + } + break; + + case NR_INFO: + case NR_INFO | NR_NAK_FLAG: + case NR_INFO | NR_CHOKE_FLAG: + case NR_INFO | NR_MORE_FLAG: + case NR_INFO | NR_NAK_FLAG | NR_CHOKE_FLAG: + case NR_INFO | NR_CHOKE_FLAG | NR_MORE_FLAG: + case NR_INFO | NR_NAK_FLAG | NR_MORE_FLAG: + case NR_INFO | NR_NAK_FLAG | NR_CHOKE_FLAG | NR_MORE_FLAG: + if (frametype & NR_CHOKE_FLAG) { + nrom->condition |= NR_COND_PEER_RX_BUSY; + nr_start_t4timer(sk); + } else { + nrom->condition &= ~NR_COND_PEER_RX_BUSY; + nr_stop_t4timer(sk); + } + if (nr_validate_nr(sk, nr)) { + if (frametype & NR_NAK_FLAG) { + nr_frames_acked(sk, nr); + nr_send_nak_frame(sk); + } else { + if (nrom->condition & NR_COND_PEER_RX_BUSY) { + nr_frames_acked(sk, nr); + } else { + nr_check_iframes_acked(sk, nr); + } + } + } + queued = 1; + skb_queue_head(&nrom->reseq_queue, skb); + if (nrom->condition & NR_COND_OWN_RX_BUSY) + break; + skb_queue_head_init(&temp_queue); + do { + save_vr = nrom->vr; + while ((skbn = skb_dequeue(&nrom->reseq_queue)) != NULL) { + ns = skbn->data[17]; + if (ns == nrom->vr) { + if (nr_queue_rx_frame(sk, skbn, frametype & NR_MORE_FLAG) == 0) { + nrom->vr = (nrom->vr + 1) % NR_MODULUS; + } else { + nrom->condition |= NR_COND_OWN_RX_BUSY; + skb_queue_tail(&temp_queue, skbn); + } + } else if (nr_in_rx_window(sk, ns)) { + skb_queue_tail(&temp_queue, skbn); + } else { + kfree_skb(skbn); + } + } + while ((skbn = skb_dequeue(&temp_queue)) != NULL) { + skb_queue_tail(&nrom->reseq_queue, skbn); + } + } while (save_vr != nrom->vr); + /* + * Window is full, ack it immediately. + */ + if (((nrom->vl + nrom->window) % NR_MODULUS) == nrom->vr) { + nr_enquiry_response(sk); + } else { + if (!(nrom->condition & NR_COND_ACK_PENDING)) { + nrom->condition |= NR_COND_ACK_PENDING; + nr_start_t2timer(sk); + } + } + break; + + default: + break; + } + return queued; +} + +/* Higher level upcall for a LAPB frame - called with sk locked */ +int nr_process_rx_frame(struct sock *sk, struct sk_buff *skb) +{ + struct nr_sock *nr = nr_sk(sk); + int queued = 0, frametype; + + if (nr->state == NR_STATE_0) + return 0; + + frametype = skb->data[19]; + + switch (nr->state) { + case NR_STATE_1: + queued = nr_state1_machine(sk, skb, frametype); + break; + case NR_STATE_2: + queued = nr_state2_machine(sk, skb, frametype); + break; + case NR_STATE_3: + queued = nr_state3_machine(sk, skb, frametype); + break; + } + + nr_kick(sk); + + return queued; +} |