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-rw-r--r--net/lapb/lapb_in.c556
1 files changed, 556 insertions, 0 deletions
diff --git a/net/lapb/lapb_in.c b/net/lapb/lapb_in.c
new file mode 100644
index 000000000..38ae23c09
--- /dev/null
+++ b/net/lapb/lapb_in.c
@@ -0,0 +1,556 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * LAPB release 002
+ *
+ * This code REQUIRES 2.1.15 or higher/ NET3.038
+ *
+ * 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);
+}
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