// SPDX-License-Identifier: GPL-2.0-or-later /* * * Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk) * * Most of this code is based on the SDL diagrams published in the 7th ARRL * Computer Networking Conference papers. The diagrams have mistakes in them, * but are mostly correct. Before you modify the code could you read the SDL * diagrams as the code is not obvious and probably very easy to break.
*/ #include <linux/errno.h> #include <linux/filter.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 <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/fcntl.h> #include <linux/mm.h> #include <linux/interrupt.h> #include <net/rose.h>
/* * State machine for state 1, Awaiting Call Accepted State. * The handling of the timer(s) is in file rose_timer.c. * Handling of state 0 and connection release is in af_rose.c.
*/ staticint rose_state1_machine(struct sock *sk, struct sk_buff *skb, int frametype)
{ struct rose_sock *rose = rose_sk(sk);
case ROSE_CLEAR_REQUEST:
rose_write_internal(sk, ROSE_CLEAR_CONFIRMATION);
rose_disconnect(sk, ECONNREFUSED, skb->data[3], skb->data[4]);
rose_neigh_put(rose->neighbour); break;
default: break;
}
return 0;
}
/* * State machine for state 2, Awaiting Clear Confirmation State. * The handling of the timer(s) is in file rose_timer.c * Handling of state 0 and connection release is in af_rose.c.
*/ staticint rose_state2_machine(struct sock *sk, struct sk_buff *skb, int frametype)
{ struct rose_sock *rose = rose_sk(sk);
case ROSE_CLEAR_CONFIRMATION:
rose_disconnect(sk, 0, -1, -1);
rose_neigh_put(rose->neighbour); break;
default: break;
}
return 0;
}
/* * State machine for state 3, Connected State. * The handling of the timer(s) is in file rose_timer.c * Handling of state 0 and connection release is in af_rose.c.
*/ staticint rose_state3_machine(struct sock *sk, struct sk_buff *skb, int frametype, int ns, int nr, int q, int d, int m)
{ enum skb_drop_reason dr; /* ignored */ struct rose_sock *rose = rose_sk(sk); int queued = 0;
case ROSE_DATA: /* XXX */
rose->condition &= ~ROSE_COND_PEER_RX_BUSY; if (!rose_validate_nr(sk, nr)) {
rose_write_internal(sk, ROSE_RESET_REQUEST);
rose->condition = 0x00;
rose->vs = 0;
rose->vr = 0;
rose->va = 0;
rose->vl = 0;
rose->state = ROSE_STATE_4;
rose_start_t2timer(sk);
rose_stop_idletimer(sk); break;
}
rose_frames_acked(sk, nr); if (ns == rose->vr) {
rose_start_idletimer(sk); if (!sk_filter_trim_cap(sk, skb, ROSE_MIN_LEN, &dr) &&
__sock_queue_rcv_skb(sk, skb) == 0) {
rose->vr = (rose->vr + 1) % ROSE_MODULUS;
queued = 1;
} else { /* Should never happen ! */
rose_write_internal(sk, ROSE_RESET_REQUEST);
rose->condition = 0x00;
rose->vs = 0;
rose->vr = 0;
rose->va = 0;
rose->vl = 0;
rose->state = ROSE_STATE_4;
rose_start_t2timer(sk);
rose_stop_idletimer(sk); break;
} if (atomic_read(&sk->sk_rmem_alloc) >
(sk->sk_rcvbuf >> 1))
rose->condition |= ROSE_COND_OWN_RX_BUSY;
} /* * If the window is full, ack the frame, else start the * acknowledge hold back timer.
*/ if (((rose->vl + sysctl_rose_window_size) % ROSE_MODULUS) == rose->vr) {
rose->condition &= ~ROSE_COND_ACK_PENDING;
rose_stop_timer(sk);
rose_enquiry_response(sk);
} else {
rose->condition |= ROSE_COND_ACK_PENDING;
rose_start_hbtimer(sk);
} break;
default:
printk(KERN_WARNING "ROSE: unknown %02X in state 3\n", frametype); break;
}
return queued;
}
/* * State machine for state 4, Awaiting Reset Confirmation State. * The handling of the timer(s) is in file rose_timer.c * Handling of state 0 and connection release is in af_rose.c.
*/ staticint rose_state4_machine(struct sock *sk, struct sk_buff *skb, int frametype)
{ struct rose_sock *rose = rose_sk(sk);
case ROSE_CLEAR_REQUEST:
rose_write_internal(sk, ROSE_CLEAR_CONFIRMATION);
rose_disconnect(sk, 0, skb->data[3], skb->data[4]);
rose_neigh_put(rose->neighbour); break;
default: break;
}
return 0;
}
/* * State machine for state 5, Awaiting Call Acceptance State. * The handling of the timer(s) is in file rose_timer.c * Handling of state 0 and connection release is in af_rose.c.
*/ staticint rose_state5_machine(struct sock *sk, struct sk_buff *skb, int frametype)
{ if (frametype == ROSE_CLEAR_REQUEST) {
rose_write_internal(sk, ROSE_CLEAR_CONFIRMATION);
rose_disconnect(sk, 0, skb->data[3], skb->data[4]);
rose_neigh_put(rose_sk(sk)->neighbour);
}
return 0;
}
/* Higher level upcall for a LAPB frame */ int rose_process_rx_frame(struct sock *sk, struct sk_buff *skb)
{ struct rose_sock *rose = rose_sk(sk); int queued = 0, frametype, ns, nr, q, d, m;
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