2 * Generic HDLC support routines for Linux
3 * Point-to-point protocol support
5 * Copyright (C) 1999 - 2008 Krzysztof Halasa <khc@pm.waw.pl>
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms of version 2 of the GNU General Public License
9 * as published by the Free Software Foundation.
12 #include <linux/errno.h>
13 #include <linux/hdlc.h>
14 #include <linux/if_arp.h>
15 #include <linux/inetdevice.h>
16 #include <linux/init.h>
17 #include <linux/kernel.h>
18 #include <linux/module.h>
19 #include <linux/pkt_sched.h>
20 #include <linux/poll.h>
21 #include <linux/skbuff.h>
22 #include <linux/slab.h>
23 #include <linux/spinlock.h>
25 #define DEBUG_CP 0 /* also bytes# to dump */
27 #define DEBUG_HARD_HEADER 0
29 #define HDLC_ADDR_ALLSTATIONS 0xFF
30 #define HDLC_CTRL_UI 0x03
32 #define PID_LCP 0xC021
34 #define PID_IPCP 0x8021
35 #define PID_IPV6 0x0057
36 #define PID_IPV6CP 0x8057
38 enum {IDX_LCP
= 0, IDX_IPCP
, IDX_IPV6CP
, IDX_COUNT
};
39 enum {CP_CONF_REQ
= 1, CP_CONF_ACK
, CP_CONF_NAK
, CP_CONF_REJ
, CP_TERM_REQ
,
40 CP_TERM_ACK
, CP_CODE_REJ
, LCP_PROTO_REJ
, LCP_ECHO_REQ
, LCP_ECHO_REPLY
,
41 LCP_DISC_REQ
, CP_CODES
};
43 static const char *const code_names
[CP_CODES
] = {
44 "0", "ConfReq", "ConfAck", "ConfNak", "ConfRej", "TermReq",
45 "TermAck", "CodeRej", "ProtoRej", "EchoReq", "EchoReply", "Discard"
47 static char debug_buffer
[64 + 3 * DEBUG_CP
];
50 enum {LCP_OPTION_MRU
= 1, LCP_OPTION_ACCM
, LCP_OPTION_MAGIC
= 5};
66 struct net_device
*dev
;
67 struct timer_list timer
;
68 unsigned long timeout
;
69 u16 pid
; /* protocol ID */
71 u8 cr_id
; /* ID of last Configuration-Request */
76 struct proto protos
[IDX_COUNT
];
78 unsigned long last_pong
;
79 unsigned int req_timeout
, cr_retries
, term_retries
;
80 unsigned int keepalive_interval
, keepalive_timeout
;
81 u8 seq
; /* local sequence number for requests */
82 u8 echo_id
; /* ID of last Echo-Request (LCP) */
85 enum {CLOSED
= 0, STOPPED
, STOPPING
, REQ_SENT
, ACK_RECV
, ACK_SENT
, OPENED
,
86 STATES
, STATE_MASK
= 0xF};
87 enum {START
= 0, STOP
, TO_GOOD
, TO_BAD
, RCR_GOOD
, RCR_BAD
, RCA
, RCN
, RTR
, RTA
,
88 RUC
, RXJ_GOOD
, RXJ_BAD
, EVENTS
};
89 enum {INV
= 0x10, IRC
= 0x20, ZRC
= 0x40, SCR
= 0x80, SCA
= 0x100,
90 SCN
= 0x200, STR
= 0x400, STA
= 0x800, SCJ
= 0x1000};
93 static const char *const state_names
[STATES
] = {
94 "Closed", "Stopped", "Stopping", "ReqSent", "AckRecv", "AckSent",
97 static const char *const event_names
[EVENTS
] = {
98 "Start", "Stop", "TO+", "TO-", "RCR+", "RCR-", "RCA", "RCN",
99 "RTR", "RTA", "RUC", "RXJ+", "RXJ-"
103 static struct sk_buff_head tx_queue
; /* used when holding the spin lock */
105 static int ppp_ioctl(struct net_device
*dev
, struct ifreq
*ifr
);
107 static inline struct ppp
* get_ppp(struct net_device
*dev
)
109 return (struct ppp
*)dev_to_hdlc(dev
)->state
;
112 static inline struct proto
* get_proto(struct net_device
*dev
, u16 pid
)
114 struct ppp
*ppp
= get_ppp(dev
);
118 return &ppp
->protos
[IDX_LCP
];
120 return &ppp
->protos
[IDX_IPCP
];
122 return &ppp
->protos
[IDX_IPV6CP
];
128 static inline const char* proto_name(u16 pid
)
142 static __be16
ppp_type_trans(struct sk_buff
*skb
, struct net_device
*dev
)
144 struct hdlc_header
*data
= (struct hdlc_header
*)skb
->data
;
146 if (skb
->len
< sizeof(struct hdlc_header
))
147 return htons(ETH_P_HDLC
);
148 if (data
->address
!= HDLC_ADDR_ALLSTATIONS
||
149 data
->control
!= HDLC_CTRL_UI
)
150 return htons(ETH_P_HDLC
);
152 switch (data
->protocol
) {
153 case cpu_to_be16(PID_IP
):
154 skb_pull(skb
, sizeof(struct hdlc_header
));
155 return htons(ETH_P_IP
);
157 case cpu_to_be16(PID_IPV6
):
158 skb_pull(skb
, sizeof(struct hdlc_header
));
159 return htons(ETH_P_IPV6
);
162 return htons(ETH_P_HDLC
);
167 static int ppp_hard_header(struct sk_buff
*skb
, struct net_device
*dev
,
168 u16 type
, const void *daddr
, const void *saddr
,
171 struct hdlc_header
*data
;
172 #if DEBUG_HARD_HEADER
173 printk(KERN_DEBUG
"%s: ppp_hard_header() called\n", dev
->name
);
176 skb_push(skb
, sizeof(struct hdlc_header
));
177 data
= (struct hdlc_header
*)skb
->data
;
179 data
->address
= HDLC_ADDR_ALLSTATIONS
;
180 data
->control
= HDLC_CTRL_UI
;
183 data
->protocol
= htons(PID_IP
);
186 data
->protocol
= htons(PID_IPV6
);
191 data
->protocol
= htons(type
);
193 default: /* unknown protocol */
196 return sizeof(struct hdlc_header
);
200 static void ppp_tx_flush(void)
203 while ((skb
= skb_dequeue(&tx_queue
)) != NULL
)
207 static void ppp_tx_cp(struct net_device
*dev
, u16 pid
, u8 code
,
208 u8 id
, unsigned int len
, const void *data
)
211 struct cp_header
*cp
;
212 unsigned int magic_len
= 0;
220 if (pid
== PID_LCP
&& (code
== LCP_ECHO_REQ
|| code
== LCP_ECHO_REPLY
))
221 magic_len
= sizeof(magic
);
223 skb
= dev_alloc_skb(sizeof(struct hdlc_header
) +
224 sizeof(struct cp_header
) + magic_len
+ len
);
226 netdev_warn(dev
, "out of memory in ppp_tx_cp()\n");
229 skb_reserve(skb
, sizeof(struct hdlc_header
));
231 cp
= skb_put(skb
, sizeof(struct cp_header
));
234 cp
->len
= htons(sizeof(struct cp_header
) + magic_len
+ len
);
237 skb_put_data(skb
, &magic
, magic_len
);
239 skb_put_data(skb
, data
, len
);
242 BUG_ON(code
>= CP_CODES
);
245 for (i
= 0; i
< min_t(unsigned int, magic_len
+ len
, DEBUG_CP
); i
++) {
246 sprintf(ptr
, " %02X", skb
->data
[sizeof(struct cp_header
) + i
]);
249 printk(KERN_DEBUG
"%s: TX %s [%s id 0x%X]%s\n", dev
->name
,
250 proto_name(pid
), code_names
[code
], id
, debug_buffer
);
253 ppp_hard_header(skb
, dev
, pid
, NULL
, NULL
, 0);
255 skb
->priority
= TC_PRIO_CONTROL
;
257 skb_reset_network_header(skb
);
258 skb_queue_tail(&tx_queue
, skb
);
262 /* State transition table (compare STD-51)
264 TO+ = Timeout with counter > 0 irc = Initialize-Restart-Count
265 TO- = Timeout with counter expired zrc = Zero-Restart-Count
267 RCR+ = Receive-Configure-Request (Good) scr = Send-Configure-Request
268 RCR- = Receive-Configure-Request (Bad)
269 RCA = Receive-Configure-Ack sca = Send-Configure-Ack
270 RCN = Receive-Configure-Nak/Rej scn = Send-Configure-Nak/Rej
272 RTR = Receive-Terminate-Request str = Send-Terminate-Request
273 RTA = Receive-Terminate-Ack sta = Send-Terminate-Ack
275 RUC = Receive-Unknown-Code scj = Send-Code-Reject
276 RXJ+ = Receive-Code-Reject (permitted)
277 or Receive-Protocol-Reject
278 RXJ- = Receive-Code-Reject (catastrophic)
279 or Receive-Protocol-Reject
281 static int cp_table
[EVENTS
][STATES
] = {
282 /* CLOSED STOPPED STOPPING REQ_SENT ACK_RECV ACK_SENT OPENED
284 {IRC
|SCR
|3, INV
, INV
, INV
, INV
, INV
, INV
}, /* START */
285 { INV
, 0 , 0 , 0 , 0 , 0 , 0 }, /* STOP */
286 { INV
, INV
,STR
|2, SCR
|3 ,SCR
|3, SCR
|5 , INV
}, /* TO+ */
287 { INV
, INV
, 1 , 1 , 1 , 1 , INV
}, /* TO- */
288 { STA
|0 ,IRC
|SCR
|SCA
|5, 2 , SCA
|5 ,SCA
|6, SCA
|5 ,SCR
|SCA
|5}, /* RCR+ */
289 { STA
|0 ,IRC
|SCR
|SCN
|3, 2 , SCN
|3 ,SCN
|4, SCN
|3 ,SCR
|SCN
|3}, /* RCR- */
290 { STA
|0 , STA
|1 , 2 , IRC
|4 ,SCR
|3, 6 , SCR
|3 }, /* RCA */
291 { STA
|0 , STA
|1 , 2 ,IRC
|SCR
|3,SCR
|3,IRC
|SCR
|5, SCR
|3 }, /* RCN */
292 { STA
|0 , STA
|1 ,STA
|2, STA
|3 ,STA
|3, STA
|3 ,ZRC
|STA
|2}, /* RTR */
293 { 0 , 1 , 1 , 3 , 3 , 5 , SCR
|3 }, /* RTA */
294 { SCJ
|0 , SCJ
|1 ,SCJ
|2, SCJ
|3 ,SCJ
|4, SCJ
|5 , SCJ
|6 }, /* RUC */
295 { 0 , 1 , 2 , 3 , 3 , 5 , 6 }, /* RXJ+ */
296 { 0 , 1 , 1 , 1 , 1 , 1 ,IRC
|STR
|2}, /* RXJ- */
300 /* SCA: RCR+ must supply id, len and data
301 SCN: RCR- must supply code, id, len and data
302 STA: RTR must supply id
303 SCJ: RUC must supply CP packet len and data */
304 static void ppp_cp_event(struct net_device
*dev
, u16 pid
, u16 event
, u8 code
,
305 u8 id
, unsigned int len
, const void *data
)
307 int old_state
, action
;
308 struct ppp
*ppp
= get_ppp(dev
);
309 struct proto
*proto
= get_proto(dev
, pid
);
311 old_state
= proto
->state
;
312 BUG_ON(old_state
>= STATES
);
313 BUG_ON(event
>= EVENTS
);
316 printk(KERN_DEBUG
"%s: %s ppp_cp_event(%s) %s ...\n", dev
->name
,
317 proto_name(pid
), event_names
[event
], state_names
[proto
->state
]);
320 action
= cp_table
[event
][old_state
];
322 proto
->state
= action
& STATE_MASK
;
323 if (action
& (SCR
| STR
)) /* set Configure-Req/Terminate-Req timer */
324 mod_timer(&proto
->timer
, proto
->timeout
=
325 jiffies
+ ppp
->req_timeout
* HZ
);
327 proto
->restart_counter
= 0;
329 proto
->restart_counter
= (proto
->state
== STOPPING
) ?
330 ppp
->term_retries
: ppp
->cr_retries
;
332 if (action
& SCR
) /* send Configure-Request */
333 ppp_tx_cp(dev
, pid
, CP_CONF_REQ
, proto
->cr_id
= ++ppp
->seq
,
335 if (action
& SCA
) /* send Configure-Ack */
336 ppp_tx_cp(dev
, pid
, CP_CONF_ACK
, id
, len
, data
);
337 if (action
& SCN
) /* send Configure-Nak/Reject */
338 ppp_tx_cp(dev
, pid
, code
, id
, len
, data
);
339 if (action
& STR
) /* send Terminate-Request */
340 ppp_tx_cp(dev
, pid
, CP_TERM_REQ
, ++ppp
->seq
, 0, NULL
);
341 if (action
& STA
) /* send Terminate-Ack */
342 ppp_tx_cp(dev
, pid
, CP_TERM_ACK
, id
, 0, NULL
);
343 if (action
& SCJ
) /* send Code-Reject */
344 ppp_tx_cp(dev
, pid
, CP_CODE_REJ
, ++ppp
->seq
, len
, data
);
346 if (old_state
!= OPENED
&& proto
->state
== OPENED
) {
347 netdev_info(dev
, "%s up\n", proto_name(pid
));
348 if (pid
== PID_LCP
) {
349 netif_dormant_off(dev
);
350 ppp_cp_event(dev
, PID_IPCP
, START
, 0, 0, 0, NULL
);
351 ppp_cp_event(dev
, PID_IPV6CP
, START
, 0, 0, 0, NULL
);
352 ppp
->last_pong
= jiffies
;
353 mod_timer(&proto
->timer
, proto
->timeout
=
354 jiffies
+ ppp
->keepalive_interval
* HZ
);
357 if (old_state
== OPENED
&& proto
->state
!= OPENED
) {
358 netdev_info(dev
, "%s down\n", proto_name(pid
));
359 if (pid
== PID_LCP
) {
360 netif_dormant_on(dev
);
361 ppp_cp_event(dev
, PID_IPCP
, STOP
, 0, 0, 0, NULL
);
362 ppp_cp_event(dev
, PID_IPV6CP
, STOP
, 0, 0, 0, NULL
);
365 if (old_state
!= CLOSED
&& proto
->state
== CLOSED
)
366 del_timer(&proto
->timer
);
369 printk(KERN_DEBUG
"%s: %s ppp_cp_event(%s) ... %s\n", dev
->name
,
370 proto_name(pid
), event_names
[event
], state_names
[proto
->state
]);
375 static void ppp_cp_parse_cr(struct net_device
*dev
, u16 pid
, u8 id
,
376 unsigned int req_len
, const u8
*data
)
378 static u8
const valid_accm
[6] = { LCP_OPTION_ACCM
, 6, 0, 0, 0, 0 };
381 unsigned int len
= req_len
, nak_len
= 0, rej_len
= 0;
383 if (!(out
= kmalloc(len
, GFP_ATOMIC
))) {
384 dev
->stats
.rx_dropped
++;
385 return; /* out of memory, ignore CR packet */
388 for (opt
= data
; len
; len
-= opt
[1], opt
+= opt
[1]) {
389 if (len
< 2 || len
< opt
[1]) {
390 dev
->stats
.rx_errors
++;
392 return; /* bad packet, drop silently */
398 continue; /* MRU always OK and > 1500 bytes? */
400 case LCP_OPTION_ACCM
: /* async control character map */
401 if (!memcmp(opt
, valid_accm
,
404 if (!rej_len
) { /* NAK it */
405 memcpy(out
+ nak_len
, valid_accm
,
407 nak_len
+= sizeof(valid_accm
);
411 case LCP_OPTION_MAGIC
:
412 if (opt
[1] != 6 || (!opt
[2] && !opt
[3] &&
414 break; /* reject invalid magic number */
417 /* reject this option */
418 memcpy(out
+ rej_len
, opt
, opt
[1]);
423 ppp_cp_event(dev
, pid
, RCR_BAD
, CP_CONF_REJ
, id
, rej_len
, out
);
425 ppp_cp_event(dev
, pid
, RCR_BAD
, CP_CONF_NAK
, id
, nak_len
, out
);
427 ppp_cp_event(dev
, pid
, RCR_GOOD
, CP_CONF_ACK
, id
, req_len
, data
);
432 static int ppp_rx(struct sk_buff
*skb
)
434 struct hdlc_header
*hdr
= (struct hdlc_header
*)skb
->data
;
435 struct net_device
*dev
= skb
->dev
;
436 struct ppp
*ppp
= get_ppp(dev
);
438 struct cp_header
*cp
;
447 spin_lock_irqsave(&ppp
->lock
, flags
);
448 /* Check HDLC header */
449 if (skb
->len
< sizeof(struct hdlc_header
))
451 cp
= skb_pull(skb
, sizeof(struct hdlc_header
));
452 if (hdr
->address
!= HDLC_ADDR_ALLSTATIONS
||
453 hdr
->control
!= HDLC_CTRL_UI
)
456 pid
= ntohs(hdr
->protocol
);
457 proto
= get_proto(dev
, pid
);
459 if (ppp
->protos
[IDX_LCP
].state
== OPENED
)
460 ppp_tx_cp(dev
, PID_LCP
, LCP_PROTO_REJ
,
461 ++ppp
->seq
, skb
->len
+ 2, &hdr
->protocol
);
465 len
= ntohs(cp
->len
);
466 if (len
< sizeof(struct cp_header
) /* no complete CP header? */ ||
467 skb
->len
< len
/* truncated packet? */)
469 skb_pull(skb
, sizeof(struct cp_header
));
470 len
-= sizeof(struct cp_header
);
472 /* HDLC and CP headers stripped from skb */
474 if (cp
->code
< CP_CODES
)
475 sprintf(debug_buffer
, "[%s id 0x%X]", code_names
[cp
->code
],
478 sprintf(debug_buffer
, "[code %u id 0x%X]", cp
->code
, cp
->id
);
479 ptr
= debug_buffer
+ strlen(debug_buffer
);
480 for (i
= 0; i
< min_t(unsigned int, len
, DEBUG_CP
); i
++) {
481 sprintf(ptr
, " %02X", skb
->data
[i
]);
484 printk(KERN_DEBUG
"%s: RX %s %s\n", dev
->name
, proto_name(pid
),
492 pid
= ntohs(*(__be16
*)skb
->data
);
493 if (pid
== PID_LCP
|| pid
== PID_IPCP
||
495 ppp_cp_event(dev
, pid
, RXJ_BAD
, 0, 0,
499 case LCP_ECHO_REQ
: /* send Echo-Reply */
500 if (len
>= 4 && proto
->state
== OPENED
)
501 ppp_tx_cp(dev
, PID_LCP
, LCP_ECHO_REPLY
,
502 cp
->id
, len
- 4, skb
->data
+ 4);
506 if (cp
->id
== ppp
->echo_id
)
507 ppp
->last_pong
= jiffies
;
510 case LCP_DISC_REQ
: /* discard */
514 /* LCP, IPCP and IPV6CP */
517 ppp_cp_parse_cr(dev
, pid
, cp
->id
, len
, skb
->data
);
521 if (cp
->id
== proto
->cr_id
)
522 ppp_cp_event(dev
, pid
, RCA
, 0, 0, 0, NULL
);
527 if (cp
->id
== proto
->cr_id
)
528 ppp_cp_event(dev
, pid
, RCN
, 0, 0, 0, NULL
);
532 ppp_cp_event(dev
, pid
, RTR
, 0, cp
->id
, 0, NULL
);
536 ppp_cp_event(dev
, pid
, RTA
, 0, 0, 0, NULL
);
540 ppp_cp_event(dev
, pid
, RXJ_BAD
, 0, 0, 0, NULL
);
544 len
+= sizeof(struct cp_header
);
547 ppp_cp_event(dev
, pid
, RUC
, 0, 0, len
, cp
);
553 dev
->stats
.rx_errors
++;
555 spin_unlock_irqrestore(&ppp
->lock
, flags
);
556 dev_kfree_skb_any(skb
);
561 static void ppp_timer(struct timer_list
*t
)
563 struct proto
*proto
= from_timer(proto
, t
, timer
);
564 struct ppp
*ppp
= get_ppp(proto
->dev
);
567 spin_lock_irqsave(&ppp
->lock
, flags
);
568 switch (proto
->state
) {
573 if (proto
->restart_counter
) {
574 ppp_cp_event(proto
->dev
, proto
->pid
, TO_GOOD
, 0, 0,
576 proto
->restart_counter
--;
577 } else if (netif_carrier_ok(proto
->dev
))
578 ppp_cp_event(proto
->dev
, proto
->pid
, TO_GOOD
, 0, 0,
581 ppp_cp_event(proto
->dev
, proto
->pid
, TO_BAD
, 0, 0,
586 if (proto
->pid
!= PID_LCP
)
588 if (time_after(jiffies
, ppp
->last_pong
+
589 ppp
->keepalive_timeout
* HZ
)) {
590 netdev_info(proto
->dev
, "Link down\n");
591 ppp_cp_event(proto
->dev
, PID_LCP
, STOP
, 0, 0, 0, NULL
);
592 ppp_cp_event(proto
->dev
, PID_LCP
, START
, 0, 0, 0, NULL
);
593 } else { /* send keep-alive packet */
594 ppp
->echo_id
= ++ppp
->seq
;
595 ppp_tx_cp(proto
->dev
, PID_LCP
, LCP_ECHO_REQ
,
596 ppp
->echo_id
, 0, NULL
);
597 proto
->timer
.expires
= jiffies
+
598 ppp
->keepalive_interval
* HZ
;
599 add_timer(&proto
->timer
);
603 spin_unlock_irqrestore(&ppp
->lock
, flags
);
608 static void ppp_start(struct net_device
*dev
)
610 struct ppp
*ppp
= get_ppp(dev
);
613 for (i
= 0; i
< IDX_COUNT
; i
++) {
614 struct proto
*proto
= &ppp
->protos
[i
];
616 timer_setup(&proto
->timer
, ppp_timer
, 0);
617 proto
->state
= CLOSED
;
619 ppp
->protos
[IDX_LCP
].pid
= PID_LCP
;
620 ppp
->protos
[IDX_IPCP
].pid
= PID_IPCP
;
621 ppp
->protos
[IDX_IPV6CP
].pid
= PID_IPV6CP
;
623 ppp_cp_event(dev
, PID_LCP
, START
, 0, 0, 0, NULL
);
626 static void ppp_stop(struct net_device
*dev
)
628 ppp_cp_event(dev
, PID_LCP
, STOP
, 0, 0, 0, NULL
);
631 static void ppp_close(struct net_device
*dev
)
636 static struct hdlc_proto proto
= {
640 .type_trans
= ppp_type_trans
,
643 .module
= THIS_MODULE
,
646 static const struct header_ops ppp_header_ops
= {
647 .create
= ppp_hard_header
,
650 static int ppp_ioctl(struct net_device
*dev
, struct ifreq
*ifr
)
652 hdlc_device
*hdlc
= dev_to_hdlc(dev
);
656 switch (ifr
->ifr_settings
.type
) {
658 if (dev_to_hdlc(dev
)->proto
!= &proto
)
660 ifr
->ifr_settings
.type
= IF_PROTO_PPP
;
661 return 0; /* return protocol only, no settable parameters */
664 if (!capable(CAP_NET_ADMIN
))
667 if (dev
->flags
& IFF_UP
)
670 /* no settable parameters */
672 result
= hdlc
->attach(dev
, ENCODING_NRZ
,PARITY_CRC16_PR1_CCITT
);
676 result
= attach_hdlc_protocol(dev
, &proto
, sizeof(struct ppp
));
681 spin_lock_init(&ppp
->lock
);
682 ppp
->req_timeout
= 2;
683 ppp
->cr_retries
= 10;
684 ppp
->term_retries
= 2;
685 ppp
->keepalive_interval
= 10;
686 ppp
->keepalive_timeout
= 60;
688 dev
->hard_header_len
= sizeof(struct hdlc_header
);
689 dev
->header_ops
= &ppp_header_ops
;
690 dev
->type
= ARPHRD_PPP
;
691 call_netdevice_notifiers(NETDEV_POST_TYPE_CHANGE
, dev
);
692 netif_dormant_on(dev
);
700 static int __init
mod_init(void)
702 skb_queue_head_init(&tx_queue
);
703 register_hdlc_protocol(&proto
);
707 static void __exit
mod_exit(void)
709 unregister_hdlc_protocol(&proto
);
713 module_init(mod_init
);
714 module_exit(mod_exit
);
716 MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
717 MODULE_DESCRIPTION("PPP protocol support for generic HDLC");
718 MODULE_LICENSE("GPL v2");