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278 lines
5.9 KiB
278 lines
5.9 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/* |
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* |
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* Copyright Jonathan Naylor G4KLX ([email protected]) |
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*/ |
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#include <linux/errno.h> |
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#include <linux/types.h> |
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#include <linux/socket.h> |
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#include <linux/in.h> |
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#include <linux/kernel.h> |
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#include <linux/timer.h> |
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#include <linux/string.h> |
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#include <linux/sockios.h> |
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#include <linux/net.h> |
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#include <linux/slab.h> |
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#include <net/ax25.h> |
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#include <linux/inet.h> |
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#include <linux/netdevice.h> |
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#include <linux/skbuff.h> |
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#include <net/sock.h> |
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#include <net/tcp_states.h> |
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#include <linux/uaccess.h> |
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#include <linux/fcntl.h> |
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#include <linux/mm.h> |
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#include <linux/interrupt.h> |
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#include <net/netrom.h> |
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/* |
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* This routine purges all of the queues of frames. |
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*/ |
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void nr_clear_queues(struct sock *sk) |
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{ |
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struct nr_sock *nr = nr_sk(sk); |
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skb_queue_purge(&sk->sk_write_queue); |
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skb_queue_purge(&nr->ack_queue); |
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skb_queue_purge(&nr->reseq_queue); |
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skb_queue_purge(&nr->frag_queue); |
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} |
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/* |
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* This routine purges the input queue of those frames that have been |
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* acknowledged. This replaces the boxes labelled "V(a) <- N(r)" on the |
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* SDL diagram. |
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*/ |
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void nr_frames_acked(struct sock *sk, unsigned short nr) |
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{ |
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struct nr_sock *nrom = nr_sk(sk); |
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struct sk_buff *skb; |
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/* |
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* Remove all the ack-ed frames from the ack queue. |
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*/ |
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if (nrom->va != nr) { |
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while (skb_peek(&nrom->ack_queue) != NULL && nrom->va != nr) { |
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skb = skb_dequeue(&nrom->ack_queue); |
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kfree_skb(skb); |
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nrom->va = (nrom->va + 1) % NR_MODULUS; |
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} |
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} |
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} |
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/* |
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* Requeue all the un-ack-ed frames on the output queue to be picked |
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* up by nr_kick called from the timer. This arrangement handles the |
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* possibility of an empty output queue. |
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*/ |
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void nr_requeue_frames(struct sock *sk) |
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{ |
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struct sk_buff *skb, *skb_prev = NULL; |
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while ((skb = skb_dequeue(&nr_sk(sk)->ack_queue)) != NULL) { |
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if (skb_prev == NULL) |
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skb_queue_head(&sk->sk_write_queue, skb); |
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else |
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skb_append(skb_prev, skb, &sk->sk_write_queue); |
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skb_prev = skb; |
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} |
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} |
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/* |
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* Validate that the value of nr is between va and vs. Return true or |
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* false for testing. |
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*/ |
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int nr_validate_nr(struct sock *sk, unsigned short nr) |
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{ |
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struct nr_sock *nrom = nr_sk(sk); |
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unsigned short vc = nrom->va; |
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while (vc != nrom->vs) { |
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if (nr == vc) return 1; |
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vc = (vc + 1) % NR_MODULUS; |
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} |
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return nr == nrom->vs; |
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} |
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/* |
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* Check that ns is within the receive window. |
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*/ |
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int nr_in_rx_window(struct sock *sk, unsigned short ns) |
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{ |
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struct nr_sock *nr = nr_sk(sk); |
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unsigned short vc = nr->vr; |
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unsigned short vt = (nr->vl + nr->window) % NR_MODULUS; |
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while (vc != vt) { |
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if (ns == vc) return 1; |
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vc = (vc + 1) % NR_MODULUS; |
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} |
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return 0; |
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} |
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/* |
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* This routine is called when the HDLC layer internally generates a |
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* control frame. |
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*/ |
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void nr_write_internal(struct sock *sk, int frametype) |
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{ |
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struct nr_sock *nr = nr_sk(sk); |
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struct sk_buff *skb; |
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unsigned char *dptr; |
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int len, timeout; |
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len = NR_NETWORK_LEN + NR_TRANSPORT_LEN; |
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switch (frametype & 0x0F) { |
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case NR_CONNREQ: |
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len += 17; |
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break; |
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case NR_CONNACK: |
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len += (nr->bpqext) ? 2 : 1; |
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break; |
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case NR_DISCREQ: |
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case NR_DISCACK: |
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case NR_INFOACK: |
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break; |
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default: |
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printk(KERN_ERR "NET/ROM: nr_write_internal - invalid frame type %d\n", frametype); |
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return; |
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} |
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if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL) |
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return; |
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/* |
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* Space for AX.25 and NET/ROM network header |
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*/ |
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skb_reserve(skb, NR_NETWORK_LEN); |
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dptr = skb_put(skb, skb_tailroom(skb)); |
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switch (frametype & 0x0F) { |
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case NR_CONNREQ: |
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timeout = nr->t1 / HZ; |
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*dptr++ = nr->my_index; |
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*dptr++ = nr->my_id; |
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*dptr++ = 0; |
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*dptr++ = 0; |
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*dptr++ = frametype; |
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*dptr++ = nr->window; |
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memcpy(dptr, &nr->user_addr, AX25_ADDR_LEN); |
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dptr[6] &= ~AX25_CBIT; |
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dptr[6] &= ~AX25_EBIT; |
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dptr[6] |= AX25_SSSID_SPARE; |
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dptr += AX25_ADDR_LEN; |
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memcpy(dptr, &nr->source_addr, AX25_ADDR_LEN); |
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dptr[6] &= ~AX25_CBIT; |
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dptr[6] &= ~AX25_EBIT; |
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dptr[6] |= AX25_SSSID_SPARE; |
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dptr += AX25_ADDR_LEN; |
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*dptr++ = timeout % 256; |
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*dptr++ = timeout / 256; |
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break; |
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case NR_CONNACK: |
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*dptr++ = nr->your_index; |
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*dptr++ = nr->your_id; |
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*dptr++ = nr->my_index; |
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*dptr++ = nr->my_id; |
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*dptr++ = frametype; |
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*dptr++ = nr->window; |
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if (nr->bpqext) *dptr++ = sysctl_netrom_network_ttl_initialiser; |
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break; |
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case NR_DISCREQ: |
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case NR_DISCACK: |
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*dptr++ = nr->your_index; |
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*dptr++ = nr->your_id; |
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*dptr++ = 0; |
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*dptr++ = 0; |
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*dptr++ = frametype; |
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break; |
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case NR_INFOACK: |
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*dptr++ = nr->your_index; |
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*dptr++ = nr->your_id; |
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*dptr++ = 0; |
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*dptr++ = nr->vr; |
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*dptr++ = frametype; |
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break; |
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} |
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nr_transmit_buffer(sk, skb); |
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} |
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/* |
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* This routine is called to send an error reply. |
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*/ |
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void __nr_transmit_reply(struct sk_buff *skb, int mine, unsigned char cmdflags) |
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{ |
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struct sk_buff *skbn; |
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unsigned char *dptr; |
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int len; |
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len = NR_NETWORK_LEN + NR_TRANSPORT_LEN + 1; |
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if ((skbn = alloc_skb(len, GFP_ATOMIC)) == NULL) |
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return; |
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skb_reserve(skbn, 0); |
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dptr = skb_put(skbn, NR_NETWORK_LEN + NR_TRANSPORT_LEN); |
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skb_copy_from_linear_data_offset(skb, 7, dptr, AX25_ADDR_LEN); |
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dptr[6] &= ~AX25_CBIT; |
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dptr[6] &= ~AX25_EBIT; |
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dptr[6] |= AX25_SSSID_SPARE; |
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dptr += AX25_ADDR_LEN; |
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skb_copy_from_linear_data(skb, dptr, AX25_ADDR_LEN); |
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dptr[6] &= ~AX25_CBIT; |
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dptr[6] |= AX25_EBIT; |
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dptr[6] |= AX25_SSSID_SPARE; |
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dptr += AX25_ADDR_LEN; |
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*dptr++ = sysctl_netrom_network_ttl_initialiser; |
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if (mine) { |
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*dptr++ = 0; |
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*dptr++ = 0; |
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*dptr++ = skb->data[15]; |
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*dptr++ = skb->data[16]; |
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} else { |
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*dptr++ = skb->data[15]; |
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*dptr++ = skb->data[16]; |
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*dptr++ = 0; |
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*dptr++ = 0; |
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} |
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*dptr++ = cmdflags; |
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*dptr++ = 0; |
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if (!nr_route_frame(skbn, NULL)) |
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kfree_skb(skbn); |
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} |
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void nr_disconnect(struct sock *sk, int reason) |
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{ |
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nr_stop_t1timer(sk); |
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nr_stop_t2timer(sk); |
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nr_stop_t4timer(sk); |
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nr_stop_idletimer(sk); |
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nr_clear_queues(sk); |
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nr_sk(sk)->state = NR_STATE_0; |
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sk->sk_state = TCP_CLOSE; |
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sk->sk_err = reason; |
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sk->sk_shutdown |= SEND_SHUTDOWN; |
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if (!sock_flag(sk, SOCK_DEAD)) { |
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sk->sk_state_change(sk); |
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sock_set_flag(sk, SOCK_DEAD); |
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} |
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}
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