/* * X.25 Packet Layer 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 2.1.15 or higher * * 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 * X.25 001 Jonathan Naylor Started coding. * X.25 002 Jonathan Naylor Centralised disconnection code. * New timer architecture. * 2000-03-20 Daniela Squassoni Disabling/enabling of facilities * negotiation. * 2000-11-10 Henner Eisen Check and reset for out-of-sequence * i-frames. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* For ip_rcv */ #include #include #include #include #include #include static int x25_queue_rx_frame(struct sock *sk, struct sk_buff *skb, int more) { struct sk_buff *skbo, *skbn = skb; if (more) { sk->protinfo.x25->fraglen += skb->len; skb_queue_tail(&sk->protinfo.x25->fragment_queue, skb); skb_set_owner_r(skb, sk); return 0; } if (!more && sk->protinfo.x25->fraglen > 0) { /* End of fragment */ int len = sk->protinfo.x25->fraglen + skb->len; if ((skbn = alloc_skb(len, GFP_ATOMIC)) == NULL){ kfree_skb(skb); return 1; } skb_queue_tail(&sk->protinfo.x25->fragment_queue, skb); skbn->h.raw = skbn->data; skbo = skb_dequeue(&sk->protinfo.x25->fragment_queue); memcpy(skb_put(skbn, skbo->len), skbo->data, skbo->len); kfree_skb(skbo); while ((skbo = skb_dequeue(&sk->protinfo.x25->fragment_queue)) != NULL) { skb_pull(skbo, (sk->protinfo.x25->neighbour->extended) ? X25_EXT_MIN_LEN : X25_STD_MIN_LEN); memcpy(skb_put(skbn, skbo->len), skbo->data, skbo->len); kfree_skb(skbo); } sk->protinfo.x25->fraglen = 0; } skb_set_owner_r(skbn, sk); skb_queue_tail(&sk->receive_queue, skbn); if (!sk->dead) sk->data_ready(sk,skbn->len); return 0; } /* * State machine for state 1, Awaiting Call Accepted State. * The handling of the timer(s) is in file x25_timer.c. * Handling of state 0 and connection release is in af_x25.c. */ static int x25_state1_machine(struct sock *sk, struct sk_buff *skb, int frametype) { x25_address source_addr, dest_addr; switch (frametype) { case X25_CALL_ACCEPTED: x25_stop_timer(sk); sk->protinfo.x25->condition = 0x00; sk->protinfo.x25->vs = 0; sk->protinfo.x25->va = 0; sk->protinfo.x25->vr = 0; sk->protinfo.x25->vl = 0; sk->protinfo.x25->state = X25_STATE_3; sk->state = TCP_ESTABLISHED; /* * Parse the data in the frame. */ skb_pull(skb, X25_STD_MIN_LEN); skb_pull(skb, x25_addr_ntoa(skb->data, &source_addr, &dest_addr)); skb_pull(skb, x25_parse_facilities(skb, &sk->protinfo.x25->facilities, &sk->protinfo.x25->vc_facil_mask)); /* * Copy any Call User Data. */ if (skb->len >= 0) { memcpy(sk->protinfo.x25->calluserdata.cuddata, skb->data, skb->len); sk->protinfo.x25->calluserdata.cudlength = skb->len; } if (!sk->dead) sk->state_change(sk); break; case X25_CLEAR_REQUEST: x25_write_internal(sk, X25_CLEAR_CONFIRMATION); x25_disconnect(sk, ECONNREFUSED, skb->data[3], skb->data[4]); break; default: break; } return 0; } /* * State machine for state 2, Awaiting Clear Confirmation State. * The handling of the timer(s) is in file x25_timer.c * Handling of state 0 and connection release is in af_x25.c. */ static int x25_state2_machine(struct sock *sk, struct sk_buff *skb, int frametype) { switch (frametype) { case X25_CLEAR_REQUEST: x25_write_internal(sk, X25_CLEAR_CONFIRMATION); x25_disconnect(sk, 0, skb->data[3], skb->data[4]); break; case X25_CLEAR_CONFIRMATION: x25_disconnect(sk, 0, 0, 0); break; default: break; } return 0; } /* * State machine for state 3, Connected State. * The handling of the timer(s) is in file x25_timer.c * Handling of state 0 and connection release is in af_x25.c. */ static int x25_state3_machine(struct sock *sk, struct sk_buff *skb, int frametype, int ns, int nr, int q, int d, int m) { int queued = 0; int modulus; modulus = (sk->protinfo.x25->neighbour->extended) ? X25_EMODULUS : X25_SMODULUS; switch (frametype) { case X25_RESET_REQUEST: x25_write_internal(sk, X25_RESET_CONFIRMATION); x25_stop_timer(sk); sk->protinfo.x25->condition = 0x00; sk->protinfo.x25->vs = 0; sk->protinfo.x25->vr = 0; sk->protinfo.x25->va = 0; sk->protinfo.x25->vl = 0; x25_requeue_frames(sk); break; case X25_CLEAR_REQUEST: x25_write_internal(sk, X25_CLEAR_CONFIRMATION); x25_disconnect(sk, 0, skb->data[3], skb->data[4]); break; case X25_RR: case X25_RNR: if (!x25_validate_nr(sk, nr)) { x25_clear_queues(sk); x25_write_internal(sk, X25_RESET_REQUEST); x25_start_t22timer(sk); sk->protinfo.x25->condition = 0x00; sk->protinfo.x25->vs = 0; sk->protinfo.x25->vr = 0; sk->protinfo.x25->va = 0; sk->protinfo.x25->vl = 0; sk->protinfo.x25->state = X25_STATE_4; } else { x25_frames_acked(sk, nr); if (frametype == X25_RNR) { sk->protinfo.x25->condition |= X25_COND_PEER_RX_BUSY; } else { sk->protinfo.x25->condition &= ~X25_COND_PEER_RX_BUSY; } } break; case X25_DATA: /* XXX */ sk->protinfo.x25->condition &= ~X25_COND_PEER_RX_BUSY; if ((ns!=sk->protinfo.x25->vr) || !x25_validate_nr(sk, nr)) { x25_clear_queues(sk); x25_write_internal(sk, X25_RESET_REQUEST); x25_start_t22timer(sk); sk->protinfo.x25->condition = 0x00; sk->protinfo.x25->vs = 0; sk->protinfo.x25->vr = 0; sk->protinfo.x25->va = 0; sk->protinfo.x25->vl = 0; sk->protinfo.x25->state = X25_STATE_4; break; } x25_frames_acked(sk, nr); if (ns == sk->protinfo.x25->vr) { if (x25_queue_rx_frame(sk, skb, m) == 0) { sk->protinfo.x25->vr = (sk->protinfo.x25->vr + 1) % modulus; queued = 1; } else { /* Should never happen */ x25_clear_queues(sk); x25_write_internal(sk, X25_RESET_REQUEST); x25_start_t22timer(sk); sk->protinfo.x25->condition = 0x00; sk->protinfo.x25->vs = 0; sk->protinfo.x25->vr = 0; sk->protinfo.x25->va = 0; sk->protinfo.x25->vl = 0; sk->protinfo.x25->state = X25_STATE_4; break; } if (atomic_read(&sk->rmem_alloc) > (sk->rcvbuf / 2)) sk->protinfo.x25->condition |= X25_COND_OWN_RX_BUSY; } /* * If the window is full Ack it immediately, else * start the holdback timer. */ if (((sk->protinfo.x25->vl + sk->protinfo.x25->facilities.winsize_in) % modulus) == sk->protinfo.x25->vr) { sk->protinfo.x25->condition &= ~X25_COND_ACK_PENDING; x25_stop_timer(sk); x25_enquiry_response(sk); } else { sk->protinfo.x25->condition |= X25_COND_ACK_PENDING; x25_start_t2timer(sk); } break; case X25_INTERRUPT_CONFIRMATION: sk->protinfo.x25->intflag = 0; break; case X25_INTERRUPT: if (sk->urginline) { queued = (sock_queue_rcv_skb(sk, skb) == 0); } else { skb_set_owner_r(skb, sk); skb_queue_tail(&sk->protinfo.x25->interrupt_in_queue, skb); queued = 1; } if (sk->proc != 0) { if (sk->proc > 0) kill_proc(sk->proc, SIGURG, 1); else kill_pg(-sk->proc, SIGURG, 1); sock_wake_async(sk->socket, 3, POLL_PRI); } x25_write_internal(sk, X25_INTERRUPT_CONFIRMATION); break; default: printk(KERN_WARNING "x25: 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 x25_timer.c * Handling of state 0 and connection release is in af_x25.c. */ static int x25_state4_machine(struct sock *sk, struct sk_buff *skb, int frametype) { switch (frametype) { case X25_RESET_REQUEST: x25_write_internal(sk, X25_RESET_CONFIRMATION); case X25_RESET_CONFIRMATION: x25_stop_timer(sk); sk->protinfo.x25->condition = 0x00; sk->protinfo.x25->va = 0; sk->protinfo.x25->vr = 0; sk->protinfo.x25->vs = 0; sk->protinfo.x25->vl = 0; sk->protinfo.x25->state = X25_STATE_3; x25_requeue_frames(sk); break; case X25_CLEAR_REQUEST: x25_write_internal(sk, X25_CLEAR_CONFIRMATION); x25_disconnect(sk, 0, skb->data[3], skb->data[4]); break; default: break; } return 0; } /* Higher level upcall for a LAPB frame */ int x25_process_rx_frame(struct sock *sk, struct sk_buff *skb) { int queued = 0, frametype, ns, nr, q, d, m; if (sk->protinfo.x25->state == X25_STATE_0) return 0; frametype = x25_decode(sk, skb, &ns, &nr, &q, &d, &m); switch (sk->protinfo.x25->state) { case X25_STATE_1: queued = x25_state1_machine(sk, skb, frametype); break; case X25_STATE_2: queued = x25_state2_machine(sk, skb, frametype); break; case X25_STATE_3: queued = x25_state3_machine(sk, skb, frametype, ns, nr, q, d, m); break; case X25_STATE_4: queued = x25_state4_machine(sk, skb, frametype); break; } x25_kick(sk); return queued; } int x25_backlog_rcv(struct sock *sk, struct sk_buff *skb) { int queued; queued = x25_process_rx_frame(sk,skb); if(!queued) kfree_skb(skb); return 0; }
