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alistair23-linux/net/netrom/nr_in.c
Thomas Gleixner 2874c5fd28 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 
Based on 1 normalized pattern(s):

  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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:32 -07:00

303 lines
6.8 KiB
C
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// SPDX-License-Identifier: GPL-2.0-or-later
/*
*
* 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/timer.h>
#include <linux/string.h>
#include <linux/sockios.h>
#include <linux/net.h>
#include <linux/slab.h>
#include <net/ax25.h>
#include <linux/inet.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <net/sock.h>
#include <net/tcp_states.h>
#include <linux/uaccess.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;
skb_reset_transport_header(skbn);
while ((skbo = skb_dequeue(&nr->frag_queue)) != NULL) {
skb_copy_from_linear_data(skbo,
skb_put(skbn, skbo->len),
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;
case NR_RESET:
if (sysctl_netrom_reset_circuit)
nr_disconnect(sk, ECONNRESET);
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);
/* fall through */
case NR_DISCACK:
nr_disconnect(sk, 0);
break;
case NR_RESET:
if (sysctl_netrom_reset_circuit)
nr_disconnect(sk, ECONNRESET);
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;
case NR_RESET:
if (sysctl_netrom_reset_circuit)
nr_disconnect(sk, ECONNRESET);
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;
}
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