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[/] [or1k_soc_on_altera_embedded_dev_kit/] [trunk/] [linux-2.6/] [linux-2.6.24/] [net/] [ax25/] [ax25_in.c] - Blame information for rev 17

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/*
 * This program 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.
 *
 * Copyright (C) Alan Cox GW4PTS (alan@lxorguk.ukuu.org.uk)
 * Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
 * Copyright (C) Joerg Reuter DL1BKE (jreuter@yaina.de)
 * Copyright (C) Hans-Joachim Hetscher DD8NE (dd8ne@bnv-bamberg.de)
 */
#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 <net/ax25.h>
#include <linux/inet.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <linux/netfilter.h>
#include <net/sock.h>
#include <net/tcp_states.h>
#include <asm/uaccess.h>
#include <asm/system.h>
#include <linux/fcntl.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
 
/*
 *      Given a fragment, queue it on the fragment queue and if the fragment
 *      is complete, send it back to ax25_rx_iframe.
 */
static int ax25_rx_fragment(ax25_cb *ax25, struct sk_buff *skb)
{
        struct sk_buff *skbn, *skbo;
 
        if (ax25->fragno != 0) {
                if (!(*skb->data & AX25_SEG_FIRST)) {
                        if ((ax25->fragno - 1) == (*skb->data & AX25_SEG_REM)) {
                                /* Enqueue fragment */
                                ax25->fragno = *skb->data & AX25_SEG_REM;
                                skb_pull(skb, 1);       /* skip fragno */
                                ax25->fraglen += skb->len;
                                skb_queue_tail(&ax25->frag_queue, skb);
 
                                /* Last fragment received ? */
                                if (ax25->fragno == 0) {
                                        skbn = alloc_skb(AX25_MAX_HEADER_LEN +
                                                         ax25->fraglen,
                                                         GFP_ATOMIC);
                                        if (!skbn) {
                                                skb_queue_purge(&ax25->frag_queue);
                                                return 1;
                                        }
 
                                        skb_reserve(skbn, AX25_MAX_HEADER_LEN);
 
                                        skbn->dev   = ax25->ax25_dev->dev;
                                        skb_reset_network_header(skbn);
                                        skb_reset_transport_header(skbn);
 
                                        /* Copy data from the fragments */
                                        while ((skbo = skb_dequeue(&ax25->frag_queue)) != NULL) {
                                                skb_copy_from_linear_data(skbo,
                                                          skb_put(skbn, skbo->len),
                                                                          skbo->len);
                                                kfree_skb(skbo);
                                        }
 
                                        ax25->fraglen = 0;
 
                                        if (ax25_rx_iframe(ax25, skbn) == 0)
                                                kfree_skb(skbn);
                                }
 
                                return 1;
                        }
                }
        } else {
                /* First fragment received */
                if (*skb->data & AX25_SEG_FIRST) {
                        skb_queue_purge(&ax25->frag_queue);
                        ax25->fragno = *skb->data & AX25_SEG_REM;
                        skb_pull(skb, 1);               /* skip fragno */
                        ax25->fraglen = skb->len;
                        skb_queue_tail(&ax25->frag_queue, skb);
                        return 1;
                }
        }
 
        return 0;
}
 
/*
 *      This is where all valid I frames are sent to, to be dispatched to
 *      whichever protocol requires them.
 */
int ax25_rx_iframe(ax25_cb *ax25, struct sk_buff *skb)
{
        int (*func)(struct sk_buff *, ax25_cb *);
        unsigned char pid;
        int queued = 0;
 
        if (skb == NULL) return 0;
 
        ax25_start_idletimer(ax25);
 
        pid = *skb->data;
 
        if (pid == AX25_P_IP) {
                /* working around a TCP bug to keep additional listeners
                 * happy. TCP re-uses the buffer and destroys the original
                 * content.
                 */
                struct sk_buff *skbn = skb_copy(skb, GFP_ATOMIC);
                if (skbn != NULL) {
                        kfree_skb(skb);
                        skb = skbn;
                }
 
                skb_pull(skb, 1);       /* Remove PID */
                skb->mac_header = skb->network_header;
                skb_reset_network_header(skb);
                skb->dev      = ax25->ax25_dev->dev;
                skb->pkt_type = PACKET_HOST;
                skb->protocol = htons(ETH_P_IP);
                netif_rx(skb);
                return 1;
        }
        if (pid == AX25_P_SEGMENT) {
                skb_pull(skb, 1);       /* Remove PID */
                return ax25_rx_fragment(ax25, skb);
        }
 
        if ((func = ax25_protocol_function(pid)) != NULL) {
                skb_pull(skb, 1);       /* Remove PID */
                return (*func)(skb, ax25);
        }
 
        if (ax25->sk != NULL && ax25->ax25_dev->values[AX25_VALUES_CONMODE] == 2) {
                if ((!ax25->pidincl && ax25->sk->sk_protocol == pid) ||
                    ax25->pidincl) {
                        if (sock_queue_rcv_skb(ax25->sk, skb) == 0)
                                queued = 1;
                        else
                                ax25->condition |= AX25_COND_OWN_RX_BUSY;
                }
        }
 
        return queued;
}
 
/*
 *      Higher level upcall for a LAPB frame
 */
static int ax25_process_rx_frame(ax25_cb *ax25, struct sk_buff *skb, int type, int dama)
{
        int queued = 0;
 
        if (ax25->state == AX25_STATE_0)
                return 0;
 
        switch (ax25->ax25_dev->values[AX25_VALUES_PROTOCOL]) {
        case AX25_PROTO_STD_SIMPLEX:
        case AX25_PROTO_STD_DUPLEX:
                queued = ax25_std_frame_in(ax25, skb, type);
                break;
 
#ifdef CONFIG_AX25_DAMA_SLAVE
        case AX25_PROTO_DAMA_SLAVE:
                if (dama || ax25->ax25_dev->dama.slave)
                        queued = ax25_ds_frame_in(ax25, skb, type);
                else
                        queued = ax25_std_frame_in(ax25, skb, type);
                break;
#endif
        }
 
        return queued;
}
 
static int ax25_rcv(struct sk_buff *skb, struct net_device *dev,
        ax25_address *dev_addr, struct packet_type *ptype)
{
        ax25_address src, dest, *next_digi = NULL;
        int type = 0, mine = 0, dama;
        struct sock *make, *sk;
        ax25_digi dp, reverse_dp;
        ax25_cb *ax25;
        ax25_dev *ax25_dev;
 
        /*
         *      Process the AX.25/LAPB frame.
         */
 
        skb_reset_transport_header(skb);
 
        if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL) {
                kfree_skb(skb);
                return 0;
        }
 
        /*
         *      Parse the address header.
         */
 
        if (ax25_addr_parse(skb->data, skb->len, &src, &dest, &dp, &type, &dama) == NULL) {
                kfree_skb(skb);
                return 0;
        }
 
        /*
         *      Ours perhaps ?
         */
        if (dp.lastrepeat + 1 < dp.ndigi)               /* Not yet digipeated completely */
                next_digi = &dp.calls[dp.lastrepeat + 1];
 
        /*
         *      Pull of the AX.25 headers leaving the CTRL/PID bytes
         */
        skb_pull(skb, ax25_addr_size(&dp));
 
        /* For our port addresses ? */
        if (ax25cmp(&dest, dev_addr) == 0 && dp.lastrepeat + 1 == dp.ndigi)
                mine = 1;
 
        /* Also match on any registered callsign from L3/4 */
        if (!mine && ax25_listen_mine(&dest, dev) && dp.lastrepeat + 1 == dp.ndigi)
                mine = 1;
 
        /* UI frame - bypass LAPB processing */
        if ((*skb->data & ~0x10) == AX25_UI && dp.lastrepeat + 1 == dp.ndigi) {
                skb_set_transport_header(skb, 2); /* skip control and pid */
 
                ax25_send_to_raw(&dest, skb, skb->data[1]);
 
                if (!mine && ax25cmp(&dest, (ax25_address *)dev->broadcast) != 0) {
                        kfree_skb(skb);
                        return 0;
                }
 
                /* Now we are pointing at the pid byte */
                switch (skb->data[1]) {
                case AX25_P_IP:
                        skb_pull(skb,2);                /* drop PID/CTRL */
                        skb_reset_transport_header(skb);
                        skb_reset_network_header(skb);
                        skb->dev      = dev;
                        skb->pkt_type = PACKET_HOST;
                        skb->protocol = htons(ETH_P_IP);
                        netif_rx(skb);
                        break;
 
                case AX25_P_ARP:
                        skb_pull(skb,2);
                        skb_reset_transport_header(skb);
                        skb_reset_network_header(skb);
                        skb->dev      = dev;
                        skb->pkt_type = PACKET_HOST;
                        skb->protocol = htons(ETH_P_ARP);
                        netif_rx(skb);
                        break;
                case AX25_P_TEXT:
                        /* Now find a suitable dgram socket */
                        sk = ax25_get_socket(&dest, &src, SOCK_DGRAM);
                        if (sk != NULL) {
                                bh_lock_sock(sk);
                                if (atomic_read(&sk->sk_rmem_alloc) >=
                                    sk->sk_rcvbuf) {
                                        kfree_skb(skb);
                                } else {
                                        /*
                                         *      Remove the control and PID.
                                         */
                                        skb_pull(skb, 2);
                                        if (sock_queue_rcv_skb(sk, skb) != 0)
                                                kfree_skb(skb);
                                }
                                bh_unlock_sock(sk);
                                sock_put(sk);
                        } else {
                                kfree_skb(skb);
                        }
                        break;
 
                default:
                        kfree_skb(skb); /* Will scan SOCK_AX25 RAW sockets */
                        break;
                }
 
                return 0;
        }
 
        /*
         *      Is connected mode supported on this device ?
         *      If not, should we DM the incoming frame (except DMs) or
         *      silently ignore them. For now we stay quiet.
         */
        if (ax25_dev->values[AX25_VALUES_CONMODE] == 0) {
                kfree_skb(skb);
                return 0;
        }
 
        /* LAPB */
 
        /* AX.25 state 1-4 */
 
        ax25_digi_invert(&dp, &reverse_dp);
 
        if ((ax25 = ax25_find_cb(&dest, &src, &reverse_dp, dev)) != NULL) {
                /*
                 *      Process the frame. If it is queued up internally it
                 *      returns one otherwise we free it immediately. This
                 *      routine itself wakes the user context layers so we do
                 *      no further work
                 */
                if (ax25_process_rx_frame(ax25, skb, type, dama) == 0)
                        kfree_skb(skb);
 
                ax25_cb_put(ax25);
                return 0;
        }
 
        /* AX.25 state 0 (disconnected) */
 
        /* a) received not a SABM(E) */
 
        if ((*skb->data & ~AX25_PF) != AX25_SABM &&
            (*skb->data & ~AX25_PF) != AX25_SABME) {
                /*
                 *      Never reply to a DM. Also ignore any connects for
                 *      addresses that are not our interfaces and not a socket.
                 */
                if ((*skb->data & ~AX25_PF) != AX25_DM && mine)
                        ax25_return_dm(dev, &src, &dest, &dp);
 
                kfree_skb(skb);
                return 0;
        }
 
        /* b) received SABM(E) */
 
        if (dp.lastrepeat + 1 == dp.ndigi)
                sk = ax25_find_listener(&dest, 0, dev, SOCK_SEQPACKET);
        else
                sk = ax25_find_listener(next_digi, 1, dev, SOCK_SEQPACKET);
 
        if (sk != NULL) {
                bh_lock_sock(sk);
                if (sk_acceptq_is_full(sk) ||
                    (make = ax25_make_new(sk, ax25_dev)) == NULL) {
                        if (mine)
                                ax25_return_dm(dev, &src, &dest, &dp);
                        kfree_skb(skb);
                        bh_unlock_sock(sk);
                        sock_put(sk);
 
                        return 0;
                }
 
                ax25 = ax25_sk(make);
                skb_set_owner_r(skb, make);
                skb_queue_head(&sk->sk_receive_queue, skb);
 
                make->sk_state = TCP_ESTABLISHED;
 
                sk->sk_ack_backlog++;
                bh_unlock_sock(sk);
        } else {
                if (!mine) {
                        kfree_skb(skb);
                        return 0;
                }
 
                if ((ax25 = ax25_create_cb()) == NULL) {
                        ax25_return_dm(dev, &src, &dest, &dp);
                        kfree_skb(skb);
                        return 0;
                }
 
                ax25_fillin_cb(ax25, ax25_dev);
        }
 
        ax25->source_addr = dest;
        ax25->dest_addr   = src;
 
        /*
         *      Sort out any digipeated paths.
         */
        if (dp.ndigi && !ax25->digipeat &&
            (ax25->digipeat = kmalloc(sizeof(ax25_digi), GFP_ATOMIC)) == NULL) {
                kfree_skb(skb);
                ax25_destroy_socket(ax25);
                if (sk)
                        sock_put(sk);
                return 0;
        }
 
        if (dp.ndigi == 0) {
                kfree(ax25->digipeat);
                ax25->digipeat = NULL;
        } else {
                /* Reverse the source SABM's path */
                memcpy(ax25->digipeat, &reverse_dp, sizeof(ax25_digi));
        }
 
        if ((*skb->data & ~AX25_PF) == AX25_SABME) {
                ax25->modulus = AX25_EMODULUS;
                ax25->window  = ax25_dev->values[AX25_VALUES_EWINDOW];
        } else {
                ax25->modulus = AX25_MODULUS;
                ax25->window  = ax25_dev->values[AX25_VALUES_WINDOW];
        }
 
        ax25_send_control(ax25, AX25_UA, AX25_POLLON, AX25_RESPONSE);
 
#ifdef CONFIG_AX25_DAMA_SLAVE
        if (dama && ax25->ax25_dev->values[AX25_VALUES_PROTOCOL] == AX25_PROTO_DAMA_SLAVE)
                ax25_dama_on(ax25);
#endif
 
        ax25->state = AX25_STATE_3;
 
        ax25_cb_add(ax25);
 
        ax25_start_heartbeat(ax25);
        ax25_start_t3timer(ax25);
        ax25_start_idletimer(ax25);
 
        if (sk) {
                if (!sock_flag(sk, SOCK_DEAD))
                        sk->sk_data_ready(sk, skb->len);
                sock_put(sk);
        } else
                kfree_skb(skb);
 
        return 0;
}
 
/*
 *      Receive an AX.25 frame via a SLIP interface.
 */
int ax25_kiss_rcv(struct sk_buff *skb, struct net_device *dev,
                  struct packet_type *ptype, struct net_device *orig_dev)
{
        skb->sk = NULL;         /* Initially we don't know who it's for */
        skb->destructor = NULL; /* Who initializes this, dammit?! */
 
        if (dev->nd_net != &init_net) {
                kfree_skb(skb);
                return 0;
        }
 
        if ((*skb->data & 0x0F) != 0) {
                kfree_skb(skb); /* Not a KISS data frame */
                return 0;
        }
 
        skb_pull(skb, AX25_KISS_HEADER_LEN);    /* Remove the KISS byte */
 
        return ax25_rcv(skb, dev, (ax25_address *)dev->dev_addr, ptype);
}

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Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

[/] [or1k_soc_on_altera_embedded_dev_kit/] [trunk/] [linux-2.6/] [linux-2.6.24/] [net/] [ax25/] [ax25_in.c] - Blame information for rev 17

Line No.	Rev	Author	Line
1	3	xianfeng	`/*`
2			`* This program is free software; you can redistribute it and/or modify`
3			`* it under the terms of the GNU General Public License as published by`
4			`* the Free Software Foundation; either version 2 of the License, or`
5			`* (at your option) any later version.`
6			`*`
7			`* Copyright (C) Alan Cox GW4PTS (alan@lxorguk.ukuu.org.uk)`
8			`* Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)`
9			`* Copyright (C) Joerg Reuter DL1BKE (jreuter@yaina.de)`
10			`* Copyright (C) Hans-Joachim Hetscher DD8NE (dd8ne@bnv-bamberg.de)`
11			`*/`
12			`#include <linux/errno.h>`
13			`#include <linux/types.h>`
14			`#include <linux/socket.h>`
15			`#include <linux/in.h>`
16			`#include <linux/kernel.h>`
17			`#include <linux/timer.h>`
18			`#include <linux/string.h>`
19			`#include <linux/sockios.h>`
20			`#include <linux/net.h>`
21			`#include <net/ax25.h>`
22			`#include <linux/inet.h>`
23			`#include <linux/netdevice.h>`
24			`#include <linux/skbuff.h>`
25			`#include <linux/netfilter.h>`
26			`#include <net/sock.h>`
27			`#include <net/tcp_states.h>`
28			`#include <asm/uaccess.h>`
29			`#include <asm/system.h>`
30			`#include <linux/fcntl.h>`
31			`#include <linux/mm.h>`
32			`#include <linux/interrupt.h>`
33
34			`/*`
35			`* Given a fragment, queue it on the fragment queue and if the fragment`
36			`* is complete, send it back to ax25_rx_iframe.`
37			`*/`
38			`static int ax25_rx_fragment(ax25_cb ax25, struct sk_buff skb)`
39			`{`
40			`struct sk_buff skbn, skbo;`
41
42			`if (ax25->fragno != 0) {`
43			`if (!(*skb->data & AX25_SEG_FIRST)) {`
44			`if ((ax25->fragno - 1) == (*skb->data & AX25_SEG_REM)) {`
45			`/* Enqueue fragment */`
46			`ax25->fragno = *skb->data & AX25_SEG_REM;`
47			`skb_pull(skb, 1); /* skip fragno */`
48			`ax25->fraglen += skb->len;`
49			`skb_queue_tail(&ax25->frag_queue, skb);`
50
51			`/* Last fragment received ? */`
52			`if (ax25->fragno == 0) {`
53			`skbn = alloc_skb(AX25_MAX_HEADER_LEN +`
54			`ax25->fraglen,`
55			`GFP_ATOMIC);`
56			`if (!skbn) {`
57			`skb_queue_purge(&ax25->frag_queue);`
58			`return 1;`
59			`}`
60
61			`skb_reserve(skbn, AX25_MAX_HEADER_LEN);`
62
63			`skbn->dev = ax25->ax25_dev->dev;`
64			`skb_reset_network_header(skbn);`
65			`skb_reset_transport_header(skbn);`
66
67			`/* Copy data from the fragments */`
68			`while ((skbo = skb_dequeue(&ax25->frag_queue)) != NULL) {`
69			`skb_copy_from_linear_data(skbo,`
70			`skb_put(skbn, skbo->len),`
71			`skbo->len);`
72			`kfree_skb(skbo);`
73			`}`
74
75			`ax25->fraglen = 0;`
76
77			`if (ax25_rx_iframe(ax25, skbn) == 0)`
78			`kfree_skb(skbn);`
79			`}`
80
81			`return 1;`
82			`}`
83			`}`
84			`} else {`
85			`/* First fragment received */`
86			`if (*skb->data & AX25_SEG_FIRST) {`
87			`skb_queue_purge(&ax25->frag_queue);`
88			`ax25->fragno = *skb->data & AX25_SEG_REM;`
89			`skb_pull(skb, 1); /* skip fragno */`
90			`ax25->fraglen = skb->len;`
91			`skb_queue_tail(&ax25->frag_queue, skb);`
92			`return 1;`
93			`}`
94			`}`
95
96			`return 0;`
97			`}`
98
99			`/*`
100			`* This is where all valid I frames are sent to, to be dispatched to`
101			`* whichever protocol requires them.`
102			`*/`
103			`int ax25_rx_iframe(ax25_cb ax25, struct sk_buff skb)`
104			`{`
105			`int (func)(struct sk_buff , ax25_cb *);`
106			`unsigned char pid;`
107			`int queued = 0;`
108
109			`if (skb == NULL) return 0;`
110
111			`ax25_start_idletimer(ax25);`
112
113			`pid = *skb->data;`
114
115			`if (pid == AX25_P_IP) {`
116			`/* working around a TCP bug to keep additional listeners`
117			`* happy. TCP re-uses the buffer and destroys the original`
118			`* content.`
119			`*/`
120			`struct sk_buff *skbn = skb_copy(skb, GFP_ATOMIC);`
121			`if (skbn != NULL) {`
122			`kfree_skb(skb);`
123			`skb = skbn;`
124			`}`
125
126			`skb_pull(skb, 1); /* Remove PID */`
127			`skb->mac_header = skb->network_header;`
128			`skb_reset_network_header(skb);`
129			`skb->dev = ax25->ax25_dev->dev;`
130			`skb->pkt_type = PACKET_HOST;`
131			`skb->protocol = htons(ETH_P_IP);`
132			`netif_rx(skb);`
133			`return 1;`
134			`}`
135			`if (pid == AX25_P_SEGMENT) {`
136			`skb_pull(skb, 1); /* Remove PID */`
137			`return ax25_rx_fragment(ax25, skb);`
138			`}`
139
140			`if ((func = ax25_protocol_function(pid)) != NULL) {`
141			`skb_pull(skb, 1); /* Remove PID */`
142			`return (*func)(skb, ax25);`
143			`}`
144
145			`if (ax25->sk != NULL && ax25->ax25_dev->values[AX25_VALUES_CONMODE] == 2) {`
146			`if ((!ax25->pidincl && ax25->sk->sk_protocol == pid) \|\|`
147			`ax25->pidincl) {`
148			`if (sock_queue_rcv_skb(ax25->sk, skb) == 0)`
149			`queued = 1;`
150			`else`
151			`ax25->condition \|= AX25_COND_OWN_RX_BUSY;`
152			`}`
153			`}`
154
155			`return queued;`
156			`}`
157
158			`/*`
159			`* Higher level upcall for a LAPB frame`
160			`*/`
161			`static int ax25_process_rx_frame(ax25_cb ax25, struct sk_buff skb, int type, int dama)`
162			`{`
163			`int queued = 0;`
164
165			`if (ax25->state == AX25_STATE_0)`
166			`return 0;`
167
168			`switch (ax25->ax25_dev->values[AX25_VALUES_PROTOCOL]) {`
169			`case AX25_PROTO_STD_SIMPLEX:`
170			`case AX25_PROTO_STD_DUPLEX:`
171			`queued = ax25_std_frame_in(ax25, skb, type);`
172			`break;`
173
174			`#ifdef CONFIG_AX25_DAMA_SLAVE`
175			`case AX25_PROTO_DAMA_SLAVE:`
176			`if (dama \|\| ax25->ax25_dev->dama.slave)`
177			`queued = ax25_ds_frame_in(ax25, skb, type);`
178			`else`
179			`queued = ax25_std_frame_in(ax25, skb, type);`
180			`break;`
181			`#endif`
182			`}`
183
184			`return queued;`
185			`}`
186
187			`static int ax25_rcv(struct sk_buff skb, struct net_device dev,`
188			`ax25_address dev_addr, struct packet_type ptype)`
189			`{`
190			`ax25_address src, dest, *next_digi = NULL;`
191			`int type = 0, mine = 0, dama;`
192			`struct sock make, sk;`
193			`ax25_digi dp, reverse_dp;`
194			`ax25_cb *ax25;`
195			`ax25_dev *ax25_dev;`
196
197			`/*`
198			`* Process the AX.25/LAPB frame.`
199			`*/`
200
201			`skb_reset_transport_header(skb);`
202
203			`if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL) {`
204			`kfree_skb(skb);`
205			`return 0;`
206			`}`
207
208			`/*`
209			`* Parse the address header.`
210			`*/`
211
212			`if (ax25_addr_parse(skb->data, skb->len, &src, &dest, &dp, &type, &dama) == NULL) {`
213			`kfree_skb(skb);`
214			`return 0;`
215			`}`
216
217			`/*`
218			`* Ours perhaps ?`
219			`*/`
220			`if (dp.lastrepeat + 1 < dp.ndigi) /* Not yet digipeated completely */`
221			`next_digi = &dp.calls[dp.lastrepeat + 1];`
222
223			`/*`
224			`* Pull of the AX.25 headers leaving the CTRL/PID bytes`
225			`*/`
226			`skb_pull(skb, ax25_addr_size(&dp));`
227
228			`/* For our port addresses ? */`
229			`if (ax25cmp(&dest, dev_addr) == 0 && dp.lastrepeat + 1 == dp.ndigi)`
230			`mine = 1;`
231
232			`/* Also match on any registered callsign from L3/4 */`
233			`if (!mine && ax25_listen_mine(&dest, dev) && dp.lastrepeat + 1 == dp.ndigi)`
234			`mine = 1;`
235
236			`/* UI frame - bypass LAPB processing */`
237			`if ((*skb->data & ~0x10) == AX25_UI && dp.lastrepeat + 1 == dp.ndigi) {`
238			`skb_set_transport_header(skb, 2); /* skip control and pid */`
239
240			`ax25_send_to_raw(&dest, skb, skb->data[1]);`
241
242			`if (!mine && ax25cmp(&dest, (ax25_address *)dev->broadcast) != 0) {`
243			`kfree_skb(skb);`
244			`return 0;`
245			`}`
246
247			`/* Now we are pointing at the pid byte */`
248			`switch (skb->data[1]) {`
249			`case AX25_P_IP:`
250			`skb_pull(skb,2); /* drop PID/CTRL */`
251			`skb_reset_transport_header(skb);`
252			`skb_reset_network_header(skb);`
253			`skb->dev = dev;`
254			`skb->pkt_type = PACKET_HOST;`
255			`skb->protocol = htons(ETH_P_IP);`
256			`netif_rx(skb);`
257			`break;`
258
259			`case AX25_P_ARP:`
260			`skb_pull(skb,2);`
261			`skb_reset_transport_header(skb);`
262			`skb_reset_network_header(skb);`
263			`skb->dev = dev;`
264			`skb->pkt_type = PACKET_HOST;`
265			`skb->protocol = htons(ETH_P_ARP);`
266			`netif_rx(skb);`
267			`break;`
268			`case AX25_P_TEXT:`
269			`/* Now find a suitable dgram socket */`
270			`sk = ax25_get_socket(&dest, &src, SOCK_DGRAM);`
271			`if (sk != NULL) {`
272			`bh_lock_sock(sk);`
273			`if (atomic_read(&sk->sk_rmem_alloc) >=`
274			`sk->sk_rcvbuf) {`
275			`kfree_skb(skb);`
276			`} else {`
277			`/*`
278			`* Remove the control and PID.`
279			`*/`
280			`skb_pull(skb, 2);`
281			`if (sock_queue_rcv_skb(sk, skb) != 0)`
282			`kfree_skb(skb);`
283			`}`
284			`bh_unlock_sock(sk);`
285			`sock_put(sk);`
286			`} else {`
287			`kfree_skb(skb);`
288			`}`
289			`break;`
290
291			`default:`
292			`kfree_skb(skb); /* Will scan SOCK_AX25 RAW sockets */`
293			`break;`
294			`}`
295
296			`return 0;`
297			`}`
298
299			`/*`
300			`* Is connected mode supported on this device ?`
301			`* If not, should we DM the incoming frame (except DMs) or`
302			`* silently ignore them. For now we stay quiet.`
303			`*/`
304			`if (ax25_dev->values[AX25_VALUES_CONMODE] == 0) {`
305			`kfree_skb(skb);`
306			`return 0;`
307			`}`
308
309			`/* LAPB */`
310
311			`/* AX.25 state 1-4 */`
312
313			`ax25_digi_invert(&dp, &reverse_dp);`
314
315			`if ((ax25 = ax25_find_cb(&dest, &src, &reverse_dp, dev)) != NULL) {`
316			`/*`
317			`* Process the frame. If it is queued up internally it`
318			`* returns one otherwise we free it immediately. This`
319			`* routine itself wakes the user context layers so we do`
320			`* no further work`
321			`*/`
322			`if (ax25_process_rx_frame(ax25, skb, type, dama) == 0)`
323			`kfree_skb(skb);`
324
325			`ax25_cb_put(ax25);`
326			`return 0;`
327			`}`
328
329			`/* AX.25 state 0 (disconnected) */`
330
331			`/* a) received not a SABM(E) */`
332
333			`if ((*skb->data & ~AX25_PF) != AX25_SABM &&`
334			`(*skb->data & ~AX25_PF) != AX25_SABME) {`
335			`/*`
336			`* Never reply to a DM. Also ignore any connects for`
337			`* addresses that are not our interfaces and not a socket.`
338			`*/`
339			`if ((*skb->data & ~AX25_PF) != AX25_DM && mine)`
340			`ax25_return_dm(dev, &src, &dest, &dp);`
341
342			`kfree_skb(skb);`
343			`return 0;`
344			`}`
345
346			`/* b) received SABM(E) */`
347
348			`if (dp.lastrepeat + 1 == dp.ndigi)`
349			`sk = ax25_find_listener(&dest, 0, dev, SOCK_SEQPACKET);`
350			`else`
351			`sk = ax25_find_listener(next_digi, 1, dev, SOCK_SEQPACKET);`
352
353			`if (sk != NULL) {`
354			`bh_lock_sock(sk);`
355			`if (sk_acceptq_is_full(sk) \|\|`
356			`(make = ax25_make_new(sk, ax25_dev)) == NULL) {`
357			`if (mine)`
358			`ax25_return_dm(dev, &src, &dest, &dp);`
359			`kfree_skb(skb);`
360			`bh_unlock_sock(sk);`
361			`sock_put(sk);`
362
363			`return 0;`
364			`}`
365
366			`ax25 = ax25_sk(make);`
367			`skb_set_owner_r(skb, make);`
368			`skb_queue_head(&sk->sk_receive_queue, skb);`
369
370			`make->sk_state = TCP_ESTABLISHED;`
371
372			`sk->sk_ack_backlog++;`
373			`bh_unlock_sock(sk);`
374			`} else {`
375			`if (!mine) {`
376			`kfree_skb(skb);`
377			`return 0;`
378			`}`
379
380			`if ((ax25 = ax25_create_cb()) == NULL) {`
381			`ax25_return_dm(dev, &src, &dest, &dp);`
382			`kfree_skb(skb);`
383			`return 0;`
384			`}`
385
386			`ax25_fillin_cb(ax25, ax25_dev);`
387			`}`
388
389			`ax25->source_addr = dest;`
390			`ax25->dest_addr = src;`
391
392			`/*`
393			`* Sort out any digipeated paths.`
394			`*/`
395			`if (dp.ndigi && !ax25->digipeat &&`
396			`(ax25->digipeat = kmalloc(sizeof(ax25_digi), GFP_ATOMIC)) == NULL) {`
397			`kfree_skb(skb);`
398			`ax25_destroy_socket(ax25);`
399			`if (sk)`
400			`sock_put(sk);`
401			`return 0;`
402			`}`
403
404			`if (dp.ndigi == 0) {`
405			`kfree(ax25->digipeat);`
406			`ax25->digipeat = NULL;`
407			`} else {`
408			`/* Reverse the source SABM's path */`
409			`memcpy(ax25->digipeat, &reverse_dp, sizeof(ax25_digi));`
410			`}`
411
412			`if ((*skb->data & ~AX25_PF) == AX25_SABME) {`
413			`ax25->modulus = AX25_EMODULUS;`
414			`ax25->window = ax25_dev->values[AX25_VALUES_EWINDOW];`
415			`} else {`
416			`ax25->modulus = AX25_MODULUS;`
417			`ax25->window = ax25_dev->values[AX25_VALUES_WINDOW];`
418			`}`
419
420			`ax25_send_control(ax25, AX25_UA, AX25_POLLON, AX25_RESPONSE);`
421
422			`#ifdef CONFIG_AX25_DAMA_SLAVE`
423			`if (dama && ax25->ax25_dev->values[AX25_VALUES_PROTOCOL] == AX25_PROTO_DAMA_SLAVE)`
424			`ax25_dama_on(ax25);`
425			`#endif`
426
427			`ax25->state = AX25_STATE_3;`
428
429			`ax25_cb_add(ax25);`
430
431			`ax25_start_heartbeat(ax25);`
432			`ax25_start_t3timer(ax25);`
433			`ax25_start_idletimer(ax25);`
434
435			`if (sk) {`
436			`if (!sock_flag(sk, SOCK_DEAD))`
437			`sk->sk_data_ready(sk, skb->len);`
438			`sock_put(sk);`
439			`} else`
440			`kfree_skb(skb);`
441
442			`return 0;`
443			`}`
444
445			`/*`
446			`* Receive an AX.25 frame via a SLIP interface.`
447			`*/`
448			`int ax25_kiss_rcv(struct sk_buff skb, struct net_device dev,`
449			`struct packet_type ptype, struct net_device orig_dev)`
450			`{`
451			`skb->sk = NULL; /* Initially we don't know who it's for */`
452			`skb->destructor = NULL; /* Who initializes this, dammit?! */`
453
454			`if (dev->nd_net != &init_net) {`
455			`kfree_skb(skb);`
456			`return 0;`
457			`}`
458
459			`if ((*skb->data & 0x0F) != 0) {`
460			`kfree_skb(skb); /* Not a KISS data frame */`
461			`return 0;`
462			`}`
463
464			`skb_pull(skb, AX25_KISS_HEADER_LEN); /* Remove the KISS byte */`
465
466			`return ax25_rcv(skb, dev, (ax25_address *)dev->dev_addr, ptype);`
467			`}`