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[/] [or1k/] [trunk/] [linux/] [linux-2.4/] [net/] [ax25/] [ax25_out.c] - Blame information for rev 1765

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/*
 *      AX.25 release 037
 *
 *      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.
 *
 *      Most of this code is based on the SDL diagrams published in the 7th
 *      ARRL Computer Networking Conference papers. The diagrams have mistakes
 *      in them, but are mostly correct. Before you modify the code could you
 *      read the SDL diagrams as the code is not obvious and probably very
 *      easy to break;
 *
 *      History
 *      AX.25 028a      Jonathan(G4KLX) New state machine based on SDL diagrams.
 *      AX.25 029       Alan(GW4PTS)    Switched to KA9Q constant names.
 *                      Jonathan(G4KLX) Only poll when window is full.
 *      AX.25 030       Jonathan(G4KLX) Added fragmentation to ax25_output.
 *                                      Added support for extended AX.25.
 *      AX.25 031       Joerg(DL1BKE)   Added DAMA support
 *                      Joerg(DL1BKE)   Modified fragmenter to fragment vanilla
 *                                      AX.25 I-Frames. Added PACLEN parameter.
 *                      Joerg(DL1BKE)   Fixed a problem with buffer allocation
 *                                      for fragments.
 *      AX.25 037       Jonathan(G4KLX) New timer architecture.
 *                      Joerg(DL1BKE)   Fixed DAMA Slave mode: will work
 *                                      on non-DAMA interfaces like AX25L2V2
 *                                      again (this behaviour is _required_).
 *                      Joerg(DL1BKE)   ax25_check_iframes_acked() returns a
 *                                      value now (for DAMA n2count handling)
 */
 
#include <linux/config.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/kernel.h>
#include <linux/sched.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 <asm/uaccess.h>
#include <asm/system.h>
#include <linux/fcntl.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
 
ax25_cb *ax25_send_frame(struct sk_buff *skb, int paclen, ax25_address *src, ax25_address *dest, ax25_digi *digi, struct net_device *dev)
{
        ax25_dev *ax25_dev;
        ax25_cb *ax25;
 
        /*
         * Take the default packet length for the device if zero is
         * specified.
         */
        if (paclen == 0) {
                if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL)
                        return NULL;
 
                paclen = ax25_dev->values[AX25_VALUES_PACLEN];
        }
 
        /*
         * Look for an existing connection.
         */
        if ((ax25 = ax25_find_cb(src, dest, digi, dev)) != NULL) {
                ax25_output(ax25, paclen, skb);
                return ax25;            /* It already existed */
        }
 
        if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL)
                return NULL;
 
        if ((ax25 = ax25_create_cb()) == NULL)
                return NULL;
 
        ax25_fillin_cb(ax25, ax25_dev);
 
        ax25->source_addr = *src;
        ax25->dest_addr   = *dest;
 
        if (digi != NULL) {
                if ((ax25->digipeat = kmalloc(sizeof(ax25_digi), GFP_ATOMIC)) == NULL) {
                        ax25_free_cb(ax25);
                        return NULL;
                }
                memcpy(ax25->digipeat, digi, sizeof(ax25_digi));
        }
 
        switch (ax25->ax25_dev->values[AX25_VALUES_PROTOCOL]) {
                case AX25_PROTO_STD_SIMPLEX:
                case AX25_PROTO_STD_DUPLEX:
                        ax25_std_establish_data_link(ax25);
                        break;
 
#ifdef CONFIG_AX25_DAMA_SLAVE
                case AX25_PROTO_DAMA_SLAVE:
                        if (ax25_dev->dama.slave)
                                ax25_ds_establish_data_link(ax25);
                        else
                                ax25_std_establish_data_link(ax25);
                        break;
#endif
        }
 
        ax25_insert_socket(ax25);
 
        ax25->state = AX25_STATE_1;
 
        ax25_start_heartbeat(ax25);
 
        ax25_output(ax25, paclen, skb);
 
        return ax25;                    /* We had to create it */
}
 
/*
 *      All outgoing AX.25 I frames pass via this routine. Therefore this is
 *      where the fragmentation of frames takes place. If fragment is set to
 *      zero then we are not allowed to do fragmentation, even if the frame
 *      is too large.
 */
void ax25_output(ax25_cb *ax25, int paclen, struct sk_buff *skb)
{
        struct sk_buff *skbn;
        unsigned char *p;
        int frontlen, len, fragno, ka9qfrag, first = 1;
        unsigned long flags;
 
        if ((skb->len - 1) > paclen) {
                if (*skb->data == AX25_P_TEXT) {
                        skb_pull(skb, 1); /* skip PID */
                        ka9qfrag = 0;
                } else {
                        paclen -= 2;    /* Allow for fragment control info */
                        ka9qfrag = 1;
                }
 
                fragno = skb->len / paclen;
                if (skb->len % paclen == 0) fragno--;
 
                frontlen = skb_headroom(skb);   /* Address space + CTRL */
 
                while (skb->len > 0) {
                        save_flags(flags);
                        cli();
 
                        if ((skbn = alloc_skb(paclen + 2 + frontlen, GFP_ATOMIC)) == NULL) {
                                restore_flags(flags);
                                printk(KERN_CRIT "AX.25: ax25_output - out of memory\n");
                                return;
                        }
 
                        if (skb->sk != NULL)
                                skb_set_owner_w(skbn, skb->sk);
 
                        restore_flags(flags);
 
                        len = (paclen > skb->len) ? skb->len : paclen;
 
                        if (ka9qfrag == 1) {
                                skb_reserve(skbn, frontlen + 2);
                                skbn->nh.raw = skbn->data + (skb->nh.raw - skb->data);
                                memcpy(skb_put(skbn, len), skb->data, len);
                                p = skb_push(skbn, 2);
 
                                *p++ = AX25_P_SEGMENT;
 
                                *p = fragno--;
                                if (first) {
                                        *p |= AX25_SEG_FIRST;
                                        first = 0;
                                }
                        } else {
                                skb_reserve(skbn, frontlen + 1);
                                skbn->nh.raw = skbn->data + (skb->nh.raw - skb->data);
                                memcpy(skb_put(skbn, len), skb->data, len);
                                p = skb_push(skbn, 1);
                                *p = AX25_P_TEXT;
                        }
 
                        skb_pull(skb, len);
                        skb_queue_tail(&ax25->write_queue, skbn); /* Throw it on the queue */
                }
 
                kfree_skb(skb);
        } else {
                skb_queue_tail(&ax25->write_queue, skb);          /* Throw it on the queue */
        }
 
        switch (ax25->ax25_dev->values[AX25_VALUES_PROTOCOL]) {
                case AX25_PROTO_STD_SIMPLEX:
                case AX25_PROTO_STD_DUPLEX:
                        ax25_kick(ax25);
                        break;
 
#ifdef CONFIG_AX25_DAMA_SLAVE
                /*
                 * A DAMA slave is _required_ to work as normal AX.25L2V2
                 * if no DAMA master is available.
                 */
                case AX25_PROTO_DAMA_SLAVE:
                        if (!ax25->ax25_dev->dama.slave) ax25_kick(ax25);
                        break;
#endif
        }
}
 
/*
 *  This procedure is passed a buffer descriptor for an iframe. It builds
 *  the rest of the control part of the frame and then writes it out.
 */
static void ax25_send_iframe(ax25_cb *ax25, struct sk_buff *skb, int poll_bit)
{
        unsigned char *frame;
 
        if (skb == NULL)
                return;
 
        skb->nh.raw = skb->data;
 
        if (ax25->modulus == AX25_MODULUS) {
                frame = skb_push(skb, 1);
 
                *frame = AX25_I;
                *frame |= (poll_bit) ? AX25_PF : 0;
                *frame |= (ax25->vr << 5);
                *frame |= (ax25->vs << 1);
        } else {
                frame = skb_push(skb, 2);
 
                frame[0] = AX25_I;
                frame[0] |= (ax25->vs << 1);
                frame[1] = (poll_bit) ? AX25_EPF : 0;
                frame[1] |= (ax25->vr << 1);
        }
 
        ax25_start_idletimer(ax25);
 
        ax25_transmit_buffer(ax25, skb, AX25_COMMAND);
}
 
void ax25_kick(ax25_cb *ax25)
{
        struct sk_buff *skb, *skbn;
        int last = 1;
        unsigned short start, end, next;
 
        if (ax25->state != AX25_STATE_3 && ax25->state != AX25_STATE_4)
                return;
 
        if (ax25->condition & AX25_COND_PEER_RX_BUSY)
                return;
 
        if (skb_peek(&ax25->write_queue) == NULL)
                return;
 
        start = (skb_peek(&ax25->ack_queue) == NULL) ? ax25->va : ax25->vs;
        end   = (ax25->va + ax25->window) % ax25->modulus;
 
        if (start == end)
                return;
 
        ax25->vs = start;
 
        /*
         * Transmit data until either we're out of data to send or
         * the window is full. Send a poll on the final I frame if
         * the window is filled.
         */
 
        /*
         * Dequeue the frame and copy it.
         */
        skb  = skb_dequeue(&ax25->write_queue);
 
        do {
                if ((skbn = skb_clone(skb, GFP_ATOMIC)) == NULL) {
                        skb_queue_head(&ax25->write_queue, skb);
                        break;
                }
 
                if (skb->sk != NULL)
                        skb_set_owner_w(skbn, skb->sk);
 
                next = (ax25->vs + 1) % ax25->modulus;
                last = (next == end);
 
                /*
                 * Transmit the frame copy.
                 * bke 960114: do not set the Poll bit on the last frame
                 * in DAMA mode.
                 */
                switch (ax25->ax25_dev->values[AX25_VALUES_PROTOCOL]) {
                        case AX25_PROTO_STD_SIMPLEX:
                        case AX25_PROTO_STD_DUPLEX:
                                ax25_send_iframe(ax25, skbn, (last) ? AX25_POLLON : AX25_POLLOFF);
                                break;
 
#ifdef CONFIG_AX25_DAMA_SLAVE
                        case AX25_PROTO_DAMA_SLAVE:
                                ax25_send_iframe(ax25, skbn, AX25_POLLOFF);
                                break;
#endif
                }
 
                ax25->vs = next;
 
                /*
                 * Requeue the original data frame.
                 */
                skb_queue_tail(&ax25->ack_queue, skb);
 
        } while (!last && (skb = skb_dequeue(&ax25->write_queue)) != NULL);
 
        ax25->condition &= ~AX25_COND_ACK_PENDING;
 
        if (!ax25_t1timer_running(ax25)) {
                ax25_stop_t3timer(ax25);
                ax25_calculate_t1(ax25);
                ax25_start_t1timer(ax25);
        }
}
 
void ax25_transmit_buffer(ax25_cb *ax25, struct sk_buff *skb, int type)
{
        struct sk_buff *skbn;
        unsigned char *ptr;
        int headroom;
 
        if (ax25->ax25_dev == NULL) {
                ax25_disconnect(ax25, ENETUNREACH);
                return;
        }
 
        headroom = ax25_addr_size(ax25->digipeat);
 
        if (skb_headroom(skb) < headroom) {
                if ((skbn = skb_realloc_headroom(skb, headroom)) == NULL) {
                        printk(KERN_CRIT "AX.25: ax25_transmit_buffer - out of memory\n");
                        kfree_skb(skb);
                        return;
                }
 
                if (skb->sk != NULL)
                        skb_set_owner_w(skbn, skb->sk);
 
                kfree_skb(skb);
                skb = skbn;
        }
 
        ptr = skb_push(skb, headroom);
 
        ax25_addr_build(ptr, &ax25->source_addr, &ax25->dest_addr, ax25->digipeat, type, ax25->modulus);
 
        skb->dev = ax25->ax25_dev->dev;
 
        ax25_queue_xmit(skb);
}
 
/*
 *      A small shim to dev_queue_xmit to add the KISS control byte, and do
 *      any packet forwarding in operation.
 */
void ax25_queue_xmit(struct sk_buff *skb)
{
        unsigned char *ptr;
 
        skb->protocol = htons(ETH_P_AX25);
        skb->dev      = ax25_fwd_dev(skb->dev);
 
        ptr  = skb_push(skb, 1);
        *ptr = 0x00;                    /* KISS */
 
        dev_queue_xmit(skb);
}
 
int ax25_check_iframes_acked(ax25_cb *ax25, unsigned short nr)
{
        if (ax25->vs == nr) {
                ax25_frames_acked(ax25, nr);
                ax25_calculate_rtt(ax25);
                ax25_stop_t1timer(ax25);
                ax25_start_t3timer(ax25);
                return 1;
        } else {
                if (ax25->va != nr) {
                        ax25_frames_acked(ax25, nr);
                        ax25_calculate_t1(ax25);
                        ax25_start_t1timer(ax25);
                        return 1;
                }
        }
        return 0;
}
 

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[/] [or1k/] [trunk/] [linux/] [linux-2.4/] [net/] [ax25/] [ax25_out.c] - Blame information for rev 1765

Line No.	Rev	Author	Line
1	1275	phoenix	`/*`
2			`* AX.25 release 037`
3			`*`
4			`* This code REQUIRES 2.1.15 or higher/ NET3.038`
5			`*`
6			`* This module:`
7			`* This module is free software; you can redistribute it and/or`
8			`* modify it under the terms of the GNU General Public License`
9			`* as published by the Free Software Foundation; either version`
10			`* 2 of the License, or (at your option) any later version.`
11			`*`
12			`* Most of this code is based on the SDL diagrams published in the 7th`
13			`* ARRL Computer Networking Conference papers. The diagrams have mistakes`
14			`* in them, but are mostly correct. Before you modify the code could you`
15			`* read the SDL diagrams as the code is not obvious and probably very`
16			`* easy to break;`
17			`*`
18			`* History`
19			`* AX.25 028a Jonathan(G4KLX) New state machine based on SDL diagrams.`
20			`* AX.25 029 Alan(GW4PTS) Switched to KA9Q constant names.`
21			`* Jonathan(G4KLX) Only poll when window is full.`
22			`* AX.25 030 Jonathan(G4KLX) Added fragmentation to ax25_output.`
23			`* Added support for extended AX.25.`
24			`* AX.25 031 Joerg(DL1BKE) Added DAMA support`
25			`* Joerg(DL1BKE) Modified fragmenter to fragment vanilla`
26			`* AX.25 I-Frames. Added PACLEN parameter.`
27			`* Joerg(DL1BKE) Fixed a problem with buffer allocation`
28			`* for fragments.`
29			`* AX.25 037 Jonathan(G4KLX) New timer architecture.`
30			`* Joerg(DL1BKE) Fixed DAMA Slave mode: will work`
31			`* on non-DAMA interfaces like AX25L2V2`
32			`* again (this behaviour is _required_).`
33			`* Joerg(DL1BKE) ax25_check_iframes_acked() returns a`
34			`* value now (for DAMA n2count handling)`
35			`*/`
36
37			`#include <linux/config.h>`
38			`#include <linux/errno.h>`
39			`#include <linux/types.h>`
40			`#include <linux/socket.h>`
41			`#include <linux/in.h>`
42			`#include <linux/kernel.h>`
43			`#include <linux/sched.h>`
44			`#include <linux/timer.h>`
45			`#include <linux/string.h>`
46			`#include <linux/sockios.h>`
47			`#include <linux/net.h>`
48			`#include <net/ax25.h>`
49			`#include <linux/inet.h>`
50			`#include <linux/netdevice.h>`
51			`#include <linux/skbuff.h>`
52			`#include <linux/netfilter.h>`
53			`#include <net/sock.h>`
54			`#include <asm/uaccess.h>`
55			`#include <asm/system.h>`
56			`#include <linux/fcntl.h>`
57			`#include <linux/mm.h>`
58			`#include <linux/interrupt.h>`
59
60			`ax25_cb ax25_send_frame(struct sk_buff skb, int paclen, ax25_address src, ax25_address dest, ax25_digi digi, struct net_device dev)`
61			`{`
62			`ax25_dev *ax25_dev;`
63			`ax25_cb *ax25;`
64
65			`/*`
66			`* Take the default packet length for the device if zero is`
67			`* specified.`
68			`*/`
69			`if (paclen == 0) {`
70			`if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL)`
71			`return NULL;`
72
73			`paclen = ax25_dev->values[AX25_VALUES_PACLEN];`
74			`}`
75
76			`/*`
77			`* Look for an existing connection.`
78			`*/`
79			`if ((ax25 = ax25_find_cb(src, dest, digi, dev)) != NULL) {`
80			`ax25_output(ax25, paclen, skb);`
81			`return ax25; /* It already existed */`
82			`}`
83
84			`if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL)`
85			`return NULL;`
86
87			`if ((ax25 = ax25_create_cb()) == NULL)`
88			`return NULL;`
89
90			`ax25_fillin_cb(ax25, ax25_dev);`
91
92			`ax25->source_addr = *src;`
93			`ax25->dest_addr = *dest;`
94
95			`if (digi != NULL) {`
96			`if ((ax25->digipeat = kmalloc(sizeof(ax25_digi), GFP_ATOMIC)) == NULL) {`
97			`ax25_free_cb(ax25);`
98			`return NULL;`
99			`}`
100			`memcpy(ax25->digipeat, digi, sizeof(ax25_digi));`
101			`}`
102
103			`switch (ax25->ax25_dev->values[AX25_VALUES_PROTOCOL]) {`
104			`case AX25_PROTO_STD_SIMPLEX:`
105			`case AX25_PROTO_STD_DUPLEX:`
106			`ax25_std_establish_data_link(ax25);`
107			`break;`
108
109			`#ifdef CONFIG_AX25_DAMA_SLAVE`
110			`case AX25_PROTO_DAMA_SLAVE:`
111			`if (ax25_dev->dama.slave)`
112			`ax25_ds_establish_data_link(ax25);`
113			`else`
114			`ax25_std_establish_data_link(ax25);`
115			`break;`
116			`#endif`
117			`}`
118
119			`ax25_insert_socket(ax25);`
120
121			`ax25->state = AX25_STATE_1;`
122
123			`ax25_start_heartbeat(ax25);`
124
125			`ax25_output(ax25, paclen, skb);`
126
127			`return ax25; /* We had to create it */`
128			`}`
129
130			`/*`
131			`* All outgoing AX.25 I frames pass via this routine. Therefore this is`
132			`* where the fragmentation of frames takes place. If fragment is set to`
133			`* zero then we are not allowed to do fragmentation, even if the frame`
134			`* is too large.`
135			`*/`
136			`void ax25_output(ax25_cb ax25, int paclen, struct sk_buff skb)`
137			`{`
138			`struct sk_buff *skbn;`
139			`unsigned char *p;`
140			`int frontlen, len, fragno, ka9qfrag, first = 1;`
141			`unsigned long flags;`
142
143			`if ((skb->len - 1) > paclen) {`
144			`if (*skb->data == AX25_P_TEXT) {`
145			`skb_pull(skb, 1); /* skip PID */`
146			`ka9qfrag = 0;`
147			`} else {`
148			`paclen -= 2; /* Allow for fragment control info */`
149			`ka9qfrag = 1;`
150			`}`
151
152			`fragno = skb->len / paclen;`
153			`if (skb->len % paclen == 0) fragno--;`
154
155			`frontlen = skb_headroom(skb); /* Address space + CTRL */`
156
157			`while (skb->len > 0) {`
158			`save_flags(flags);`
159			`cli();`
160
161			`if ((skbn = alloc_skb(paclen + 2 + frontlen, GFP_ATOMIC)) == NULL) {`
162			`restore_flags(flags);`
163			`printk(KERN_CRIT "AX.25: ax25_output - out of memory\n");`
164			`return;`
165			`}`
166
167			`if (skb->sk != NULL)`
168			`skb_set_owner_w(skbn, skb->sk);`
169
170			`restore_flags(flags);`
171
172			`len = (paclen > skb->len) ? skb->len : paclen;`
173
174			`if (ka9qfrag == 1) {`
175			`skb_reserve(skbn, frontlen + 2);`
176			`skbn->nh.raw = skbn->data + (skb->nh.raw - skb->data);`
177			`memcpy(skb_put(skbn, len), skb->data, len);`
178			`p = skb_push(skbn, 2);`
179
180			`*p++ = AX25_P_SEGMENT;`
181
182			`*p = fragno--;`
183			`if (first) {`
184			`*p \|= AX25_SEG_FIRST;`
185			`first = 0;`
186			`}`
187			`} else {`
188			`skb_reserve(skbn, frontlen + 1);`
189			`skbn->nh.raw = skbn->data + (skb->nh.raw - skb->data);`
190			`memcpy(skb_put(skbn, len), skb->data, len);`
191			`p = skb_push(skbn, 1);`
192			`*p = AX25_P_TEXT;`
193			`}`
194
195			`skb_pull(skb, len);`
196			`skb_queue_tail(&ax25->write_queue, skbn); /* Throw it on the queue */`
197			`}`
198
199			`kfree_skb(skb);`
200			`} else {`
201			`skb_queue_tail(&ax25->write_queue, skb); /* Throw it on the queue */`
202			`}`
203
204			`switch (ax25->ax25_dev->values[AX25_VALUES_PROTOCOL]) {`
205			`case AX25_PROTO_STD_SIMPLEX:`
206			`case AX25_PROTO_STD_DUPLEX:`
207			`ax25_kick(ax25);`
208			`break;`
209
210			`#ifdef CONFIG_AX25_DAMA_SLAVE`
211			`/*`
212			`* A DAMA slave is _required_ to work as normal AX.25L2V2`
213			`* if no DAMA master is available.`
214			`*/`
215			`case AX25_PROTO_DAMA_SLAVE:`
216			`if (!ax25->ax25_dev->dama.slave) ax25_kick(ax25);`
217			`break;`
218			`#endif`
219			`}`
220			`}`
221
222			`/*`
223			`* This procedure is passed a buffer descriptor for an iframe. It builds`
224			`* the rest of the control part of the frame and then writes it out.`
225			`*/`
226			`static void ax25_send_iframe(ax25_cb ax25, struct sk_buff skb, int poll_bit)`
227			`{`
228			`unsigned char *frame;`
229
230			`if (skb == NULL)`
231			`return;`
232
233			`skb->nh.raw = skb->data;`
234
235			`if (ax25->modulus == AX25_MODULUS) {`
236			`frame = skb_push(skb, 1);`
237
238			`*frame = AX25_I;`
239			`*frame \|= (poll_bit) ? AX25_PF : 0;`
240			`*frame \|= (ax25->vr << 5);`
241			`*frame \|= (ax25->vs << 1);`
242			`} else {`
243			`frame = skb_push(skb, 2);`
244
245			`frame[0] = AX25_I;`
246			`frame[0] \|= (ax25->vs << 1);`
247			`frame[1] = (poll_bit) ? AX25_EPF : 0;`
248			`frame[1] \|= (ax25->vr << 1);`
249			`}`
250
251			`ax25_start_idletimer(ax25);`
252
253			`ax25_transmit_buffer(ax25, skb, AX25_COMMAND);`
254			`}`
255
256			`void ax25_kick(ax25_cb *ax25)`
257			`{`
258			`struct sk_buff skb, skbn;`
259			`int last = 1;`
260			`unsigned short start, end, next;`
261
262			`if (ax25->state != AX25_STATE_3 && ax25->state != AX25_STATE_4)`
263			`return;`
264
265			`if (ax25->condition & AX25_COND_PEER_RX_BUSY)`
266			`return;`
267
268			`if (skb_peek(&ax25->write_queue) == NULL)`
269			`return;`
270
271			`start = (skb_peek(&ax25->ack_queue) == NULL) ? ax25->va : ax25->vs;`
272			`end = (ax25->va + ax25->window) % ax25->modulus;`
273
274			`if (start == end)`
275			`return;`
276
277			`ax25->vs = start;`
278
279			`/*`
280			`* Transmit data until either we're out of data to send or`
281			`* the window is full. Send a poll on the final I frame if`
282			`* the window is filled.`
283			`*/`
284
285			`/*`
286			`* Dequeue the frame and copy it.`
287			`*/`
288			`skb = skb_dequeue(&ax25->write_queue);`
289
290			`do {`
291			`if ((skbn = skb_clone(skb, GFP_ATOMIC)) == NULL) {`
292			`skb_queue_head(&ax25->write_queue, skb);`
293			`break;`
294			`}`
295
296			`if (skb->sk != NULL)`
297			`skb_set_owner_w(skbn, skb->sk);`
298
299			`next = (ax25->vs + 1) % ax25->modulus;`
300			`last = (next == end);`
301
302			`/*`
303			`* Transmit the frame copy.`
304			`* bke 960114: do not set the Poll bit on the last frame`
305			`* in DAMA mode.`
306			`*/`
307			`switch (ax25->ax25_dev->values[AX25_VALUES_PROTOCOL]) {`
308			`case AX25_PROTO_STD_SIMPLEX:`
309			`case AX25_PROTO_STD_DUPLEX:`
310			`ax25_send_iframe(ax25, skbn, (last) ? AX25_POLLON : AX25_POLLOFF);`
311			`break;`
312
313			`#ifdef CONFIG_AX25_DAMA_SLAVE`
314			`case AX25_PROTO_DAMA_SLAVE:`
315			`ax25_send_iframe(ax25, skbn, AX25_POLLOFF);`
316			`break;`
317			`#endif`
318			`}`
319
320			`ax25->vs = next;`
321
322			`/*`
323			`* Requeue the original data frame.`
324			`*/`
325			`skb_queue_tail(&ax25->ack_queue, skb);`
326
327			`} while (!last && (skb = skb_dequeue(&ax25->write_queue)) != NULL);`
328
329			`ax25->condition &= ~AX25_COND_ACK_PENDING;`
330
331			`if (!ax25_t1timer_running(ax25)) {`
332			`ax25_stop_t3timer(ax25);`
333			`ax25_calculate_t1(ax25);`
334			`ax25_start_t1timer(ax25);`
335			`}`
336			`}`
337
338			`void ax25_transmit_buffer(ax25_cb ax25, struct sk_buff skb, int type)`
339			`{`
340			`struct sk_buff *skbn;`
341			`unsigned char *ptr;`
342			`int headroom;`
343
344			`if (ax25->ax25_dev == NULL) {`
345			`ax25_disconnect(ax25, ENETUNREACH);`
346			`return;`
347			`}`
348
349			`headroom = ax25_addr_size(ax25->digipeat);`
350
351			`if (skb_headroom(skb) < headroom) {`
352			`if ((skbn = skb_realloc_headroom(skb, headroom)) == NULL) {`
353			`printk(KERN_CRIT "AX.25: ax25_transmit_buffer - out of memory\n");`
354			`kfree_skb(skb);`
355			`return;`
356			`}`
357
358			`if (skb->sk != NULL)`
359			`skb_set_owner_w(skbn, skb->sk);`
360
361			`kfree_skb(skb);`
362			`skb = skbn;`
363			`}`
364
365			`ptr = skb_push(skb, headroom);`
366
367			`ax25_addr_build(ptr, &ax25->source_addr, &ax25->dest_addr, ax25->digipeat, type, ax25->modulus);`
368
369			`skb->dev = ax25->ax25_dev->dev;`
370
371			`ax25_queue_xmit(skb);`
372			`}`
373
374			`/*`
375			`* A small shim to dev_queue_xmit to add the KISS control byte, and do`
376			`* any packet forwarding in operation.`
377			`*/`
378			`void ax25_queue_xmit(struct sk_buff *skb)`
379			`{`
380			`unsigned char *ptr;`
381
382			`skb->protocol = htons(ETH_P_AX25);`
383			`skb->dev = ax25_fwd_dev(skb->dev);`
384
385			`ptr = skb_push(skb, 1);`
386			`ptr = 0x00; / KISS */`
387
388			`dev_queue_xmit(skb);`
389			`}`
390
391			`int ax25_check_iframes_acked(ax25_cb *ax25, unsigned short nr)`
392			`{`
393			`if (ax25->vs == nr) {`
394			`ax25_frames_acked(ax25, nr);`
395			`ax25_calculate_rtt(ax25);`
396			`ax25_stop_t1timer(ax25);`
397			`ax25_start_t3timer(ax25);`
398			`return 1;`
399			`} else {`
400			`if (ax25->va != nr) {`
401			`ax25_frames_acked(ax25, nr);`
402			`ax25_calculate_t1(ax25);`
403			`ax25_start_t1timer(ax25);`
404			`return 1;`
405			`}`
406			`}`
407			`return 0;`
408			`}`
409