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-rw-r--r--net/netrom/nr_subr.c279
1 files changed, 279 insertions, 0 deletions
diff --git a/net/netrom/nr_subr.c b/net/netrom/nr_subr.c
new file mode 100644
index 000000000..e2d2af924
--- /dev/null
+++ b/net/netrom/nr_subr.c
@@ -0,0 +1,279 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *
+ * Copyright Jonathan Naylor G4KLX (g4klx@g4klx.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>
+
+/*
+ * This routine purges all of the queues of frames.
+ */
+void nr_clear_queues(struct sock *sk)
+{
+ struct nr_sock *nr = nr_sk(sk);
+
+ skb_queue_purge(&sk->sk_write_queue);
+ skb_queue_purge(&nr->ack_queue);
+ skb_queue_purge(&nr->reseq_queue);
+ skb_queue_purge(&nr->frag_queue);
+}
+
+/*
+ * This routine purges the input queue of those frames that have been
+ * acknowledged. This replaces the boxes labelled "V(a) <- N(r)" on the
+ * SDL diagram.
+ */
+void nr_frames_acked(struct sock *sk, unsigned short nr)
+{
+ struct nr_sock *nrom = nr_sk(sk);
+ struct sk_buff *skb;
+
+ /*
+ * Remove all the ack-ed frames from the ack queue.
+ */
+ if (nrom->va != nr) {
+ while (skb_peek(&nrom->ack_queue) != NULL && nrom->va != nr) {
+ skb = skb_dequeue(&nrom->ack_queue);
+ kfree_skb(skb);
+ nrom->va = (nrom->va + 1) % NR_MODULUS;
+ }
+ }
+}
+
+/*
+ * Requeue all the un-ack-ed frames on the output queue to be picked
+ * up by nr_kick called from the timer. This arrangement handles the
+ * possibility of an empty output queue.
+ */
+void nr_requeue_frames(struct sock *sk)
+{
+ struct sk_buff *skb, *skb_prev = NULL;
+
+ while ((skb = skb_dequeue(&nr_sk(sk)->ack_queue)) != NULL) {
+ if (skb_prev == NULL)
+ skb_queue_head(&sk->sk_write_queue, skb);
+ else
+ skb_append(skb_prev, skb, &sk->sk_write_queue);
+ skb_prev = skb;
+ }
+}
+
+/*
+ * Validate that the value of nr is between va and vs. Return true or
+ * false for testing.
+ */
+int nr_validate_nr(struct sock *sk, unsigned short nr)
+{
+ struct nr_sock *nrom = nr_sk(sk);
+ unsigned short vc = nrom->va;
+
+ while (vc != nrom->vs) {
+ if (nr == vc) return 1;
+ vc = (vc + 1) % NR_MODULUS;
+ }
+
+ return nr == nrom->vs;
+}
+
+/*
+ * Check that ns is within the receive window.
+ */
+int nr_in_rx_window(struct sock *sk, unsigned short ns)
+{
+ struct nr_sock *nr = nr_sk(sk);
+ unsigned short vc = nr->vr;
+ unsigned short vt = (nr->vl + nr->window) % NR_MODULUS;
+
+ while (vc != vt) {
+ if (ns == vc) return 1;
+ vc = (vc + 1) % NR_MODULUS;
+ }
+
+ return 0;
+}
+
+/*
+ * This routine is called when the HDLC layer internally generates a
+ * control frame.
+ */
+void nr_write_internal(struct sock *sk, int frametype)
+{
+ struct nr_sock *nr = nr_sk(sk);
+ struct sk_buff *skb;
+ unsigned char *dptr;
+ int len, timeout;
+
+ len = NR_TRANSPORT_LEN;
+
+ switch (frametype & 0x0F) {
+ case NR_CONNREQ:
+ len += 17;
+ break;
+ case NR_CONNACK:
+ len += (nr->bpqext) ? 2 : 1;
+ break;
+ case NR_DISCREQ:
+ case NR_DISCACK:
+ case NR_INFOACK:
+ break;
+ default:
+ printk(KERN_ERR "NET/ROM: nr_write_internal - invalid frame type %d\n", frametype);
+ return;
+ }
+
+ skb = alloc_skb(NR_NETWORK_LEN + len, GFP_ATOMIC);
+ if (!skb)
+ return;
+
+ /*
+ * Space for AX.25 and NET/ROM network header
+ */
+ skb_reserve(skb, NR_NETWORK_LEN);
+
+ dptr = skb_put(skb, len);
+
+ switch (frametype & 0x0F) {
+ case NR_CONNREQ:
+ timeout = nr->t1 / HZ;
+ *dptr++ = nr->my_index;
+ *dptr++ = nr->my_id;
+ *dptr++ = 0;
+ *dptr++ = 0;
+ *dptr++ = frametype;
+ *dptr++ = nr->window;
+ memcpy(dptr, &nr->user_addr, AX25_ADDR_LEN);
+ dptr[6] &= ~AX25_CBIT;
+ dptr[6] &= ~AX25_EBIT;
+ dptr[6] |= AX25_SSSID_SPARE;
+ dptr += AX25_ADDR_LEN;
+ memcpy(dptr, &nr->source_addr, AX25_ADDR_LEN);
+ dptr[6] &= ~AX25_CBIT;
+ dptr[6] &= ~AX25_EBIT;
+ dptr[6] |= AX25_SSSID_SPARE;
+ dptr += AX25_ADDR_LEN;
+ *dptr++ = timeout % 256;
+ *dptr++ = timeout / 256;
+ break;
+
+ case NR_CONNACK:
+ *dptr++ = nr->your_index;
+ *dptr++ = nr->your_id;
+ *dptr++ = nr->my_index;
+ *dptr++ = nr->my_id;
+ *dptr++ = frametype;
+ *dptr++ = nr->window;
+ if (nr->bpqext) *dptr++ = sysctl_netrom_network_ttl_initialiser;
+ break;
+
+ case NR_DISCREQ:
+ case NR_DISCACK:
+ *dptr++ = nr->your_index;
+ *dptr++ = nr->your_id;
+ *dptr++ = 0;
+ *dptr++ = 0;
+ *dptr++ = frametype;
+ break;
+
+ case NR_INFOACK:
+ *dptr++ = nr->your_index;
+ *dptr++ = nr->your_id;
+ *dptr++ = 0;
+ *dptr++ = nr->vr;
+ *dptr++ = frametype;
+ break;
+ }
+
+ nr_transmit_buffer(sk, skb);
+}
+
+/*
+ * This routine is called to send an error reply.
+ */
+void __nr_transmit_reply(struct sk_buff *skb, int mine, unsigned char cmdflags)
+{
+ struct sk_buff *skbn;
+ unsigned char *dptr;
+ int len;
+
+ len = NR_NETWORK_LEN + NR_TRANSPORT_LEN + 1;
+
+ if ((skbn = alloc_skb(len, GFP_ATOMIC)) == NULL)
+ return;
+
+ skb_reserve(skbn, 0);
+
+ dptr = skb_put(skbn, NR_NETWORK_LEN + NR_TRANSPORT_LEN);
+
+ skb_copy_from_linear_data_offset(skb, 7, dptr, AX25_ADDR_LEN);
+ dptr[6] &= ~AX25_CBIT;
+ dptr[6] &= ~AX25_EBIT;
+ dptr[6] |= AX25_SSSID_SPARE;
+ dptr += AX25_ADDR_LEN;
+
+ skb_copy_from_linear_data(skb, dptr, AX25_ADDR_LEN);
+ dptr[6] &= ~AX25_CBIT;
+ dptr[6] |= AX25_EBIT;
+ dptr[6] |= AX25_SSSID_SPARE;
+ dptr += AX25_ADDR_LEN;
+
+ *dptr++ = sysctl_netrom_network_ttl_initialiser;
+
+ if (mine) {
+ *dptr++ = 0;
+ *dptr++ = 0;
+ *dptr++ = skb->data[15];
+ *dptr++ = skb->data[16];
+ } else {
+ *dptr++ = skb->data[15];
+ *dptr++ = skb->data[16];
+ *dptr++ = 0;
+ *dptr++ = 0;
+ }
+
+ *dptr++ = cmdflags;
+ *dptr++ = 0;
+
+ if (!nr_route_frame(skbn, NULL))
+ kfree_skb(skbn);
+}
+
+void nr_disconnect(struct sock *sk, int reason)
+{
+ nr_stop_t1timer(sk);
+ nr_stop_t2timer(sk);
+ nr_stop_t4timer(sk);
+ nr_stop_idletimer(sk);
+
+ nr_clear_queues(sk);
+
+ nr_sk(sk)->state = NR_STATE_0;
+
+ sk->sk_state = TCP_CLOSE;
+ sk->sk_err = reason;
+ sk->sk_shutdown |= SEND_SHUTDOWN;
+
+ if (!sock_flag(sk, SOCK_DEAD)) {
+ sk->sk_state_change(sk);
+ sock_set_flag(sk, SOCK_DEAD);
+ }
+}
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