/* * LAPB release 002 * * This code REQUIRES 2.1.15 or higher/ NET3.038 * * 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 * LAPB 001 Jonathan Naulor Started Coding * LAPB 002 Jonathan Naylor New timer architecture. * 2000-10-29 Henner Eisen lapb_data_indication() return status. */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #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/inet.h> #include <linux/netdevice.h> #include <linux/skbuff.h> #include <linux/slab.h> #include <net/sock.h> #include <linux/uaccess.h> #include <linux/fcntl.h> #include <linux/mm.h> #include <linux/interrupt.h> #include <net/lapb.h> /* * State machine for state 0, Disconnected State. * The handling of the timer(s) is in file lapb_timer.c. */ static void lapb_state0_machine(struct lapb_cb *lapb, struct sk_buff *skb, struct lapb_frame *frame) { switch (frame->type) { case LAPB_SABM: lapb_dbg(1, "(%p) S0 RX SABM(%d)\n", lapb->dev, frame->pf); if (lapb->mode & LAPB_EXTENDED) { lapb_dbg(1, "(%p) S0 TX DM(%d)\n", lapb->dev, frame->pf); lapb_send_control(lapb, LAPB_DM, frame->pf, LAPB_RESPONSE); } else { lapb_dbg(1, "(%p) S0 TX UA(%d)\n", lapb->dev, frame->pf); lapb_dbg(0, "(%p) S0 -> S3\n", lapb->dev); lapb_send_control(lapb, LAPB_UA, frame->pf, LAPB_RESPONSE); lapb_stop_t1timer(lapb); lapb_stop_t2timer(lapb); lapb->state = LAPB_STATE_3; lapb->condition = 0x00; lapb->n2count = 0; lapb->vs = 0; lapb->vr = 0; lapb->va = 0; lapb_connect_indication(lapb, LAPB_OK); } break; case LAPB_SABME: lapb_dbg(1, "(%p) S0 RX SABME(%d)\n", lapb->dev, frame->pf); if (lapb->mode & LAPB_EXTENDED) { lapb_dbg(1, "(%p) S0 TX UA(%d)\n", lapb->dev, frame->pf); lapb_dbg(0, "(%p) S0 -> S3\n", lapb->dev); lapb_send_control(lapb, LAPB_UA, frame->pf, LAPB_RESPONSE); lapb_stop_t1timer(lapb); lapb_stop_t2timer(lapb); lapb->state = LAPB_STATE_3; lapb->condition = 0x00; lapb->n2count = 0; lapb->vs = 0; lapb->vr = 0; lapb->va = 0; lapb_connect_indication(lapb, LAPB_OK); } else { lapb_dbg(1, "(%p) S0 TX DM(%d)\n", lapb->dev, frame->pf); lapb_send_control(lapb, LAPB_DM, frame->pf, LAPB_RESPONSE); } break; case LAPB_DISC: lapb_dbg(1, "(%p) S0 RX DISC(%d)\n", lapb->dev, frame->pf); lapb_dbg(1, "(%p) S0 TX UA(%d)\n", lapb->dev, frame->pf); lapb_send_control(lapb, LAPB_UA, frame->pf, LAPB_RESPONSE); break; default: break; } kfree_skb(skb); } /* * State machine for state 1, Awaiting Connection State. * The handling of the timer(s) is in file lapb_timer.c. */ static void lapb_state1_machine(struct lapb_cb *lapb, struct sk_buff *skb, struct lapb_frame *frame) { switch (frame->type) { case LAPB_SABM: lapb_dbg(1, "(%p) S1 RX SABM(%d)\n", lapb->dev, frame->pf); if (lapb->mode & LAPB_EXTENDED) { lapb_dbg(1, "(%p) S1 TX DM(%d)\n", lapb->dev, frame->pf); lapb_send_control(lapb, LAPB_DM, frame->pf, LAPB_RESPONSE); } else { lapb_dbg(1, "(%p) S1 TX UA(%d)\n", lapb->dev, frame->pf); lapb_send_control(lapb, LAPB_UA, frame->pf, LAPB_RESPONSE); } break; case LAPB_SABME: lapb_dbg(1, "(%p) S1 RX SABME(%d)\n", lapb->dev, frame->pf); if (lapb->mode & LAPB_EXTENDED) { lapb_dbg(1, "(%p) S1 TX UA(%d)\n", lapb->dev, frame->pf); lapb_send_control(lapb, LAPB_UA, frame->pf, LAPB_RESPONSE); } else { lapb_dbg(1, "(%p) S1 TX DM(%d)\n", lapb->dev, frame->pf); lapb_send_control(lapb, LAPB_DM, frame->pf, LAPB_RESPONSE); } break; case LAPB_DISC: lapb_dbg(1, "(%p) S1 RX DISC(%d)\n", lapb->dev, frame->pf); lapb_dbg(1, "(%p) S1 TX DM(%d)\n", lapb->dev, frame->pf); lapb_send_control(lapb, LAPB_DM, frame->pf, LAPB_RESPONSE); break; case LAPB_UA: lapb_dbg(1, "(%p) S1 RX UA(%d)\n", lapb->dev, frame->pf); if (frame->pf) { lapb_dbg(0, "(%p) S1 -> S3\n", lapb->dev); lapb_stop_t1timer(lapb); lapb_stop_t2timer(lapb); lapb->state = LAPB_STATE_3; lapb->condition = 0x00; lapb->n2count = 0; lapb->vs = 0; lapb->vr = 0; lapb->va = 0; lapb_connect_confirmation(lapb, LAPB_OK); } break; case LAPB_DM: lapb_dbg(1, "(%p) S1 RX DM(%d)\n", lapb->dev, frame->pf); if (frame->pf) { lapb_dbg(0, "(%p) S1 -> S0\n", lapb->dev); lapb_clear_queues(lapb); lapb->state = LAPB_STATE_0; lapb_start_t1timer(lapb); lapb_stop_t2timer(lapb); lapb_disconnect_indication(lapb, LAPB_REFUSED); } break; } kfree_skb(skb); } /* * State machine for state 2, Awaiting Release State. * The handling of the timer(s) is in file lapb_timer.c */ static void lapb_state2_machine(struct lapb_cb *lapb, struct sk_buff *skb, struct lapb_frame *frame) { switch (frame->type) { case LAPB_SABM: case LAPB_SABME: lapb_dbg(1, "(%p) S2 RX {SABM,SABME}(%d)\n", lapb->dev, frame->pf); lapb_dbg(1, "(%p) S2 TX DM(%d)\n", lapb->dev, frame->pf); lapb_send_control(lapb, LAPB_DM, frame->pf, LAPB_RESPONSE); break; case LAPB_DISC: lapb_dbg(1, "(%p) S2 RX DISC(%d)\n", lapb->dev, frame->pf); lapb_dbg(1, "(%p) S2 TX UA(%d)\n", lapb->dev, frame->pf); lapb_send_control(lapb, LAPB_UA, frame->pf, LAPB_RESPONSE); break; case LAPB_UA: lapb_dbg(1, "(%p) S2 RX UA(%d)\n", lapb->dev, frame->pf); if (frame->pf) { lapb_dbg(0, "(%p) S2 -> S0\n", lapb->dev); lapb->state = LAPB_STATE_0; lapb_start_t1timer(lapb); lapb_stop_t2timer(lapb); lapb_disconnect_confirmation(lapb, LAPB_OK); } break; case LAPB_DM: lapb_dbg(1, "(%p) S2 RX DM(%d)\n", lapb->dev, frame->pf); if (frame->pf) { lapb_dbg(0, "(%p) S2 -> S0\n", lapb->dev); lapb->state = LAPB_STATE_0; lapb_start_t1timer(lapb); lapb_stop_t2timer(lapb); lapb_disconnect_confirmation(lapb, LAPB_NOTCONNECTED); } break; case LAPB_I: case LAPB_REJ: case LAPB_RNR: case LAPB_RR: lapb_dbg(1, "(%p) S2 RX {I,REJ,RNR,RR}(%d)\n", lapb->dev, frame->pf); lapb_dbg(1, "(%p) S2 RX DM(%d)\n", lapb->dev, frame->pf); if (frame->pf) lapb_send_control(lapb, LAPB_DM, frame->pf, LAPB_RESPONSE); break; } kfree_skb(skb); } /* * State machine for state 3, Connected State. * The handling of the timer(s) is in file lapb_timer.c */ static void lapb_state3_machine(struct lapb_cb *lapb, struct sk_buff *skb, struct lapb_frame *frame) { int queued = 0; int modulus = (lapb->mode & LAPB_EXTENDED) ? LAPB_EMODULUS : LAPB_SMODULUS; switch (frame->type) { case LAPB_SABM: lapb_dbg(1, "(%p) S3 RX SABM(%d)\n", lapb->dev, frame->pf); if (lapb->mode & LAPB_EXTENDED) { lapb_dbg(1, "(%p) S3 TX DM(%d)\n", lapb->dev, frame->pf); lapb_send_control(lapb, LAPB_DM, frame->pf, LAPB_RESPONSE); } else { lapb_dbg(1, "(%p) S3 TX UA(%d)\n", lapb->dev, frame->pf); lapb_send_control(lapb, LAPB_UA, frame->pf, LAPB_RESPONSE); lapb_stop_t1timer(lapb); lapb_stop_t2timer(lapb); lapb->condition = 0x00; lapb->n2count = 0; lapb->vs = 0; lapb->vr = 0; lapb->va = 0; lapb_requeue_frames(lapb); } break; case LAPB_SABME: lapb_dbg(1, "(%p) S3 RX SABME(%d)\n", lapb->dev, frame->pf); if (lapb->mode & LAPB_EXTENDED) { lapb_dbg(1, "(%p) S3 TX UA(%d)\n", lapb->dev, frame->pf); lapb_send_control(lapb, LAPB_UA, frame->pf, LAPB_RESPONSE); lapb_stop_t1timer(lapb); lapb_stop_t2timer(lapb); lapb->condition = 0x00; lapb->n2count = 0; lapb->vs = 0; lapb->vr = 0; lapb->va = 0; lapb_requeue_frames(lapb); } else { lapb_dbg(1, "(%p) S3 TX DM(%d)\n", lapb->dev, frame->pf); lapb_send_control(lapb, LAPB_DM, frame->pf, LAPB_RESPONSE); } break; case LAPB_DISC: lapb_dbg(1, "(%p) S3 RX DISC(%d)\n", lapb->dev, frame->pf); lapb_dbg(0, "(%p) S3 -> S0\n", lapb->dev); lapb_clear_queues(lapb); lapb_send_control(lapb, LAPB_UA, frame->pf, LAPB_RESPONSE); lapb_start_t1timer(lapb); lapb_stop_t2timer(lapb); lapb->state = LAPB_STATE_0; lapb_disconnect_indication(lapb, LAPB_OK); break; case LAPB_DM: lapb_dbg(1, "(%p) S3 RX DM(%d)\n", lapb->dev, frame->pf); lapb_dbg(0, "(%p) S3 -> S0\n", lapb->dev); lapb_clear_queues(lapb); lapb->state = LAPB_STATE_0; lapb_start_t1timer(lapb); lapb_stop_t2timer(lapb); lapb_disconnect_indication(lapb, LAPB_NOTCONNECTED); break; case LAPB_RNR: lapb_dbg(1, "(%p) S3 RX RNR(%d) R%d\n", lapb->dev, frame->pf, frame->nr); lapb->condition |= LAPB_PEER_RX_BUSY_CONDITION; lapb_check_need_response(lapb, frame->cr, frame->pf); if (lapb_validate_nr(lapb, frame->nr)) { lapb_check_iframes_acked(lapb, frame->nr); } else { lapb->frmr_data = *frame; lapb->frmr_type = LAPB_FRMR_Z; lapb_transmit_frmr(lapb); lapb_dbg(0, "(%p) S3 -> S4\n", lapb->dev); lapb_start_t1timer(lapb); lapb_stop_t2timer(lapb); lapb->state = LAPB_STATE_4; lapb->n2count = 0; } break; case LAPB_RR: lapb_dbg(1, "(%p) S3 RX RR(%d) R%d\n", lapb->dev, frame->pf, frame->nr); lapb->condition &= ~LAPB_PEER_RX_BUSY_CONDITION; lapb_check_need_response(lapb, frame->cr, frame->pf); if (lapb_validate_nr(lapb, frame->nr)) { lapb_check_iframes_acked(lapb, frame->nr); } else { lapb->frmr_data = *frame; lapb->frmr_type = LAPB_FRMR_Z; lapb_transmit_frmr(lapb); lapb_dbg(0, "(%p) S3 -> S4\n", lapb->dev); lapb_start_t1timer(lapb); lapb_stop_t2timer(lapb); lapb->state = LAPB_STATE_4; lapb->n2count = 0; } break; case LAPB_REJ: lapb_dbg(1, "(%p) S3 RX REJ(%d) R%d\n", lapb->dev, frame->pf, frame->nr); lapb->condition &= ~LAPB_PEER_RX_BUSY_CONDITION; lapb_check_need_response(lapb, frame->cr, frame->pf); if (lapb_validate_nr(lapb, frame->nr)) { lapb_frames_acked(lapb, frame->nr); lapb_stop_t1timer(lapb); lapb->n2count = 0; lapb_requeue_frames(lapb); } else { lapb->frmr_data = *frame; lapb->frmr_type = LAPB_FRMR_Z; lapb_transmit_frmr(lapb); lapb_dbg(0, "(%p) S3 -> S4\n", lapb->dev); lapb_start_t1timer(lapb); lapb_stop_t2timer(lapb); lapb->state = LAPB_STATE_4; lapb->n2count = 0; } break; case LAPB_I: lapb_dbg(1, "(%p) S3 RX I(%d) S%d R%d\n", lapb->dev, frame->pf, frame->ns, frame->nr); if (!lapb_validate_nr(lapb, frame->nr)) { lapb->frmr_data = *frame; lapb->frmr_type = LAPB_FRMR_Z; lapb_transmit_frmr(lapb); lapb_dbg(0, "(%p) S3 -> S4\n", lapb->dev); lapb_start_t1timer(lapb); lapb_stop_t2timer(lapb); lapb->state = LAPB_STATE_4; lapb->n2count = 0; break; } if (lapb->condition & LAPB_PEER_RX_BUSY_CONDITION) lapb_frames_acked(lapb, frame->nr); else lapb_check_iframes_acked(lapb, frame->nr); if (frame->ns == lapb->vr) { int cn; cn = lapb_data_indication(lapb, skb); queued = 1; /* * If upper layer has dropped the frame, we * basically ignore any further protocol * processing. This will cause the peer * to re-transmit the frame later like * a frame lost on the wire. */ if (cn == NET_RX_DROP) { pr_debug("rx congestion\n"); break; } lapb->vr = (lapb->vr + 1) % modulus; lapb->condition &= ~LAPB_REJECT_CONDITION; if (frame->pf) lapb_enquiry_response(lapb); else { if (!(lapb->condition & LAPB_ACK_PENDING_CONDITION)) { lapb->condition |= LAPB_ACK_PENDING_CONDITION; lapb_start_t2timer(lapb); } } } else { if (lapb->condition & LAPB_REJECT_CONDITION) { if (frame->pf) lapb_enquiry_response(lapb); } else { lapb_dbg(1, "(%p) S3 TX REJ(%d) R%d\n", lapb->dev, frame->pf, lapb->vr); lapb->condition |= LAPB_REJECT_CONDITION; lapb_send_control(lapb, LAPB_REJ, frame->pf, LAPB_RESPONSE); lapb->condition &= ~LAPB_ACK_PENDING_CONDITION; } } break; case LAPB_FRMR: lapb_dbg(1, "(%p) S3 RX FRMR(%d) %5ph\n", lapb->dev, frame->pf, skb->data); lapb_establish_data_link(lapb); lapb_dbg(0, "(%p) S3 -> S1\n", lapb->dev); lapb_requeue_frames(lapb); lapb->state = LAPB_STATE_1; break; case LAPB_ILLEGAL: lapb_dbg(1, "(%p) S3 RX ILLEGAL(%d)\n", lapb->dev, frame->pf); lapb->frmr_data = *frame; lapb->frmr_type = LAPB_FRMR_W; lapb_transmit_frmr(lapb); lapb_dbg(0, "(%p) S3 -> S4\n", lapb->dev); lapb_start_t1timer(lapb); lapb_stop_t2timer(lapb); lapb->state = LAPB_STATE_4; lapb->n2count = 0; break; } if (!queued) kfree_skb(skb); } /* * State machine for state 4, Frame Reject State. * The handling of the timer(s) is in file lapb_timer.c. */ static void lapb_state4_machine(struct lapb_cb *lapb, struct sk_buff *skb, struct lapb_frame *frame) { switch (frame->type) { case LAPB_SABM: lapb_dbg(1, "(%p) S4 RX SABM(%d)\n", lapb->dev, frame->pf); if (lapb->mode & LAPB_EXTENDED) { lapb_dbg(1, "(%p) S4 TX DM(%d)\n", lapb->dev, frame->pf); lapb_send_control(lapb, LAPB_DM, frame->pf, LAPB_RESPONSE); } else { lapb_dbg(1, "(%p) S4 TX UA(%d)\n", lapb->dev, frame->pf); lapb_dbg(0, "(%p) S4 -> S3\n", lapb->dev); lapb_send_control(lapb, LAPB_UA, frame->pf, LAPB_RESPONSE); lapb_stop_t1timer(lapb); lapb_stop_t2timer(lapb); lapb->state = LAPB_STATE_3; lapb->condition = 0x00; lapb->n2count = 0; lapb->vs = 0; lapb->vr = 0; lapb->va = 0; lapb_connect_indication(lapb, LAPB_OK); } break; case LAPB_SABME: lapb_dbg(1, "(%p) S4 RX SABME(%d)\n", lapb->dev, frame->pf); if (lapb->mode & LAPB_EXTENDED) { lapb_dbg(1, "(%p) S4 TX UA(%d)\n", lapb->dev, frame->pf); lapb_dbg(0, "(%p) S4 -> S3\n", lapb->dev); lapb_send_control(lapb, LAPB_UA, frame->pf, LAPB_RESPONSE); lapb_stop_t1timer(lapb); lapb_stop_t2timer(lapb); lapb->state = LAPB_STATE_3; lapb->condition = 0x00; lapb->n2count = 0; lapb->vs = 0; lapb->vr = 0; lapb->va = 0; lapb_connect_indication(lapb, LAPB_OK); } else { lapb_dbg(1, "(%p) S4 TX DM(%d)\n", lapb->dev, frame->pf); lapb_send_control(lapb, LAPB_DM, frame->pf, LAPB_RESPONSE); } break; } kfree_skb(skb); } /* * Process an incoming LAPB frame */ void lapb_data_input(struct lapb_cb *lapb, struct sk_buff *skb) { struct lapb_frame frame; if (lapb_decode(lapb, skb, &frame) < 0) { kfree_skb(skb); return; } switch (lapb->state) { case LAPB_STATE_0: lapb_state0_machine(lapb, skb, &frame); break; case LAPB_STATE_1: lapb_state1_machine(lapb, skb, &frame); break; case LAPB_STATE_2: lapb_state2_machine(lapb, skb, &frame); break; case LAPB_STATE_3: lapb_state3_machine(lapb, skb, &frame); break; case LAPB_STATE_4: lapb_state4_machine(lapb, skb, &frame); break; } lapb_kick(lapb); }