3 * DECnet An implementation of the DECnet protocol suite for the LINUX
4 * operating system. DECnet is implemented using the BSD Socket
5 * interface as the means of communication with the user level.
7 * DECnet Network Services Protocol (Output)
9 * Author: Eduardo Marcelo Serrat <emserrat@geocities.com>
13 * Steve Whitehouse: Split into dn_nsp_in.c and dn_nsp_out.c from
15 * Steve Whitehouse: Updated to work with my new routing architecture.
16 * Steve Whitehouse: Added changes from Eduardo Serrat's patches.
17 * Steve Whitehouse: Now conninits have the "return" bit set.
18 * Steve Whitehouse: Fixes to check alloc'd skbs are non NULL!
19 * Moved output state machine into one function
20 * Steve Whitehouse: New output state machine
21 * Paul Koning: Connect Confirm message fix.
22 * Eduardo Serrat: Fix to stop dn_nsp_do_disc() sending malformed packets.
23 * Steve Whitehouse: dn_nsp_output() and friends needed a spring clean
24 * Steve Whitehouse: Moved dn_nsp_send() in here from route.h
27 /******************************************************************************
28 (c) 1995-1998 E.M. Serrat emserrat@geocities.com
30 This program is free software; you can redistribute it and/or modify
31 it under the terms of the GNU General Public License as published by
32 the Free Software Foundation; either version 2 of the License, or
35 This program is distributed in the hope that it will be useful,
36 but WITHOUT ANY WARRANTY; without even the implied warranty of
37 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
38 GNU General Public License for more details.
39 *******************************************************************************/
41 #include <linux/errno.h>
42 #include <linux/types.h>
43 #include <linux/socket.h>
45 #include <linux/kernel.h>
46 #include <linux/timer.h>
47 #include <linux/string.h>
48 #include <linux/sockios.h>
49 #include <linux/net.h>
50 #include <linux/netdevice.h>
51 #include <linux/inet.h>
52 #include <linux/route.h>
53 #include <linux/slab.h>
55 #include <asm/system.h>
56 #include <linux/fcntl.h>
58 #include <linux/termios.h>
59 #include <linux/interrupt.h>
60 #include <linux/proc_fs.h>
61 #include <linux/stat.h>
62 #include <linux/init.h>
63 #include <linux/poll.h>
64 #include <linux/if_packet.h>
65 #include <net/neighbour.h>
69 #include <net/dn_nsp.h>
70 #include <net/dn_dev.h>
71 #include <net/dn_route.h>
74 static int nsp_backoff
[NSP_MAXRXTSHIFT
+ 1] = { 1, 2, 4, 8, 16, 32, 64, 64, 64, 64, 64, 64, 64 };
76 static void dn_nsp_send(struct sk_buff
*skb
)
78 struct sock
*sk
= skb
->sk
;
79 struct dn_scp
*scp
= DN_SK(sk
);
80 struct dst_entry
*dst
;
83 skb_reset_transport_header(skb
);
86 dst
= sk_dst_check(sk
, 0);
89 skb_dst_set(skb
, dst
);
94 memset(&fl
, 0, sizeof(fl
));
95 fl
.oif
= sk
->sk_bound_dev_if
;
96 fl
.fld_src
= dn_saddr2dn(&scp
->addr
);
97 fl
.fld_dst
= dn_saddr2dn(&scp
->peer
);
98 dn_sk_ports_copy(&fl
, scp
);
99 fl
.proto
= DNPROTO_NSP
;
100 if (dn_route_output_sock(&sk
->sk_dst_cache
, &fl
, sk
, 0) == 0) {
101 dst
= sk_dst_get(sk
);
102 sk
->sk_route_caps
= dst
->dev
->features
;
106 sk
->sk_err
= EHOSTUNREACH
;
107 if (!sock_flag(sk
, SOCK_DEAD
))
108 sk
->sk_state_change(sk
);
113 * If sk == NULL, then we assume that we are supposed to be making
114 * a routing layer skb. If sk != NULL, then we are supposed to be
115 * creating an skb for the NSP layer.
117 * The eventual aim is for each socket to have a cached header size
118 * for its outgoing packets, and to set hdr from this when sk != NULL.
120 struct sk_buff
*dn_alloc_skb(struct sock
*sk
, int size
, gfp_t pri
)
125 if ((skb
= alloc_skb(size
+ hdr
, pri
)) == NULL
)
128 skb
->protocol
= htons(ETH_P_DNA_RT
);
129 skb
->pkt_type
= PACKET_OUTGOING
;
132 skb_set_owner_w(skb
, sk
);
134 skb_reserve(skb
, hdr
);
140 * Calculate persist timer based upon the smoothed round
141 * trip time and the variance. Backoff according to the
142 * nsp_backoff[] array.
144 unsigned long dn_nsp_persist(struct sock
*sk
)
146 struct dn_scp
*scp
= DN_SK(sk
);
148 unsigned long t
= ((scp
->nsp_srtt
>> 2) + scp
->nsp_rttvar
) >> 1;
150 t
*= nsp_backoff
[scp
->nsp_rxtshift
];
153 if (t
> (600*HZ
)) t
= (600*HZ
);
155 if (scp
->nsp_rxtshift
< NSP_MAXRXTSHIFT
)
158 /* printk(KERN_DEBUG "rxtshift %lu, t=%lu\n", scp->nsp_rxtshift, t); */
164 * This is called each time we get an estimate for the rtt
167 static void dn_nsp_rtt(struct sock
*sk
, long rtt
)
169 struct dn_scp
*scp
= DN_SK(sk
);
170 long srtt
= (long)scp
->nsp_srtt
;
171 long rttvar
= (long)scp
->nsp_rttvar
;
175 * If the jiffies clock flips over in the middle of timestamp
176 * gathering this value might turn out negative, so we make sure
177 * that is it always positive here.
182 * Add new rtt to smoothed average
184 delta
= ((rtt
<< 3) - srtt
);
185 srtt
+= (delta
>> 3);
187 scp
->nsp_srtt
= (unsigned long)srtt
;
192 * Add new rtt varience to smoothed varience
195 rttvar
+= ((((delta
>0)?(delta
):(-delta
)) - rttvar
) >> 2);
197 scp
->nsp_rttvar
= (unsigned long)rttvar
;
201 /* printk(KERN_DEBUG "srtt=%lu rttvar=%lu\n", scp->nsp_srtt, scp->nsp_rttvar); */
205 * dn_nsp_clone_and_send - Send a data packet by cloning it
206 * @skb: The packet to clone and transmit
207 * @gfp: memory allocation flag
209 * Clone a queued data or other data packet and transmit it.
211 * Returns: The number of times the packet has been sent previously
213 static inline unsigned dn_nsp_clone_and_send(struct sk_buff
*skb
,
216 struct dn_skb_cb
*cb
= DN_SKB_CB(skb
);
217 struct sk_buff
*skb2
;
220 if ((skb2
= skb_clone(skb
, gfp
)) != NULL
) {
221 ret
= cb
->xmit_count
;
232 * dn_nsp_output - Try and send something from socket queues
233 * @sk: The socket whose queues are to be investigated
235 * Try and send the packet on the end of the data and other data queues.
236 * Other data gets priority over data, and if we retransmit a packet we
237 * reduce the window by dividing it in two.
240 void dn_nsp_output(struct sock
*sk
)
242 struct dn_scp
*scp
= DN_SK(sk
);
244 unsigned reduce_win
= 0;
247 * First we check for otherdata/linkservice messages
249 if ((skb
= skb_peek(&scp
->other_xmit_queue
)) != NULL
)
250 reduce_win
= dn_nsp_clone_and_send(skb
, GFP_ATOMIC
);
253 * If we may not send any data, we don't.
254 * If we are still trying to get some other data down the
255 * channel, we don't try and send any data.
257 if (reduce_win
|| (scp
->flowrem_sw
!= DN_SEND
))
260 if ((skb
= skb_peek(&scp
->data_xmit_queue
)) != NULL
)
261 reduce_win
= dn_nsp_clone_and_send(skb
, GFP_ATOMIC
);
264 * If we've sent any frame more than once, we cut the
265 * send window size in half. There is always a minimum
266 * window size of one available.
270 scp
->snd_window
>>= 1;
271 if (scp
->snd_window
< NSP_MIN_WINDOW
)
272 scp
->snd_window
= NSP_MIN_WINDOW
;
276 int dn_nsp_xmit_timeout(struct sock
*sk
)
278 struct dn_scp
*scp
= DN_SK(sk
);
282 if (!skb_queue_empty(&scp
->data_xmit_queue
) ||
283 !skb_queue_empty(&scp
->other_xmit_queue
))
284 scp
->persist
= dn_nsp_persist(sk
);
289 static inline __le16
*dn_mk_common_header(struct dn_scp
*scp
, struct sk_buff
*skb
, unsigned char msgflag
, int len
)
291 unsigned char *ptr
= skb_push(skb
, len
);
296 *((__le16
*)ptr
) = scp
->addrrem
;
298 *((__le16
*)ptr
) = scp
->addrloc
;
300 return (__le16 __force
*)ptr
;
303 static __le16
*dn_mk_ack_header(struct sock
*sk
, struct sk_buff
*skb
, unsigned char msgflag
, int hlen
, int other
)
305 struct dn_scp
*scp
= DN_SK(sk
);
306 unsigned short acknum
= scp
->numdat_rcv
& 0x0FFF;
307 unsigned short ackcrs
= scp
->numoth_rcv
& 0x0FFF;
312 scp
->ackxmt_dat
= acknum
;
313 scp
->ackxmt_oth
= ackcrs
;
317 /* If this is an "other data/ack" message, swap acknum and ackcrs */
319 unsigned short tmp
= acknum
;
324 /* Set "cross subchannel" bit in ackcrs */
327 ptr
= (__le16
*)dn_mk_common_header(scp
, skb
, msgflag
, hlen
);
329 *ptr
++ = cpu_to_le16(acknum
);
330 *ptr
++ = cpu_to_le16(ackcrs
);
335 static __le16
*dn_nsp_mk_data_header(struct sock
*sk
, struct sk_buff
*skb
, int oth
)
337 struct dn_scp
*scp
= DN_SK(sk
);
338 struct dn_skb_cb
*cb
= DN_SKB_CB(skb
);
339 __le16
*ptr
= dn_mk_ack_header(sk
, skb
, cb
->nsp_flags
, 11, oth
);
342 cb
->segnum
= scp
->numoth
;
343 seq_add(&scp
->numoth
, 1);
345 cb
->segnum
= scp
->numdat
;
346 seq_add(&scp
->numdat
, 1);
348 *(ptr
++) = cpu_to_le16(cb
->segnum
);
353 void dn_nsp_queue_xmit(struct sock
*sk
, struct sk_buff
*skb
,
356 struct dn_scp
*scp
= DN_SK(sk
);
357 struct dn_skb_cb
*cb
= DN_SKB_CB(skb
);
358 unsigned long t
= ((scp
->nsp_srtt
>> 2) + scp
->nsp_rttvar
) >> 1;
361 dn_nsp_mk_data_header(sk
, skb
, oth
);
364 * Slow start: If we have been idle for more than
365 * one RTT, then reset window to min size.
367 if ((jiffies
- scp
->stamp
) > t
)
368 scp
->snd_window
= NSP_MIN_WINDOW
;
371 skb_queue_tail(&scp
->other_xmit_queue
, skb
);
373 skb_queue_tail(&scp
->data_xmit_queue
, skb
);
375 if (scp
->flowrem_sw
!= DN_SEND
)
378 dn_nsp_clone_and_send(skb
, gfp
);
382 int dn_nsp_check_xmit_queue(struct sock
*sk
, struct sk_buff
*skb
, struct sk_buff_head
*q
, unsigned short acknum
)
384 struct dn_skb_cb
*cb
= DN_SKB_CB(skb
);
385 struct dn_scp
*scp
= DN_SK(sk
);
386 struct sk_buff
*skb2
, *n
, *ack
= NULL
;
389 unsigned long reftime
= cb
->stamp
;
390 unsigned long pkttime
;
391 unsigned short xmit_count
;
392 unsigned short segnum
;
394 skb_queue_walk_safe(q
, skb2
, n
) {
395 struct dn_skb_cb
*cb2
= DN_SKB_CB(skb2
);
397 if (dn_before_or_equal(cb2
->segnum
, acknum
))
400 /* printk(KERN_DEBUG "ack: %s %04x %04x\n", ack ? "ACK" : "SKIP", (int)cb2->segnum, (int)acknum); */
405 /* printk(KERN_DEBUG "check_xmit_queue: %04x, %d\n", acknum, cb2->xmit_count); */
407 /* Does _last_ packet acked have xmit_count > 1 */
409 /* Remember to wake up the sending process */
411 /* Keep various statistics */
412 pkttime
= cb2
->stamp
;
413 xmit_count
= cb2
->xmit_count
;
414 segnum
= cb2
->segnum
;
415 /* Remove and drop ack'ed packet */
421 * We don't expect to see acknowledgements for packets we
424 WARN_ON(xmit_count
== 0);
427 * If the packet has only been sent once, we can use it
428 * to calculate the RTT and also open the window a little
431 if (xmit_count
== 1) {
432 if (dn_equal(segnum
, acknum
))
433 dn_nsp_rtt(sk
, (long)(pkttime
- reftime
));
435 if (scp
->snd_window
< scp
->max_window
)
440 * Packet has been sent more than once. If this is the last
441 * packet to be acknowledged then we want to send the next
442 * packet in the send queue again (assumes the remote host does
443 * go-back-N error control).
455 void dn_nsp_send_data_ack(struct sock
*sk
)
457 struct sk_buff
*skb
= NULL
;
459 if ((skb
= dn_alloc_skb(sk
, 9, GFP_ATOMIC
)) == NULL
)
463 dn_mk_ack_header(sk
, skb
, 0x04, 9, 0);
467 void dn_nsp_send_oth_ack(struct sock
*sk
)
469 struct sk_buff
*skb
= NULL
;
471 if ((skb
= dn_alloc_skb(sk
, 9, GFP_ATOMIC
)) == NULL
)
475 dn_mk_ack_header(sk
, skb
, 0x14, 9, 1);
480 void dn_send_conn_ack (struct sock
*sk
)
482 struct dn_scp
*scp
= DN_SK(sk
);
483 struct sk_buff
*skb
= NULL
;
484 struct nsp_conn_ack_msg
*msg
;
486 if ((skb
= dn_alloc_skb(sk
, 3, sk
->sk_allocation
)) == NULL
)
489 msg
= (struct nsp_conn_ack_msg
*)skb_put(skb
, 3);
491 msg
->dstaddr
= scp
->addrrem
;
496 void dn_nsp_delayed_ack(struct sock
*sk
)
498 struct dn_scp
*scp
= DN_SK(sk
);
500 if (scp
->ackxmt_oth
!= scp
->numoth_rcv
)
501 dn_nsp_send_oth_ack(sk
);
503 if (scp
->ackxmt_dat
!= scp
->numdat_rcv
)
504 dn_nsp_send_data_ack(sk
);
507 static int dn_nsp_retrans_conn_conf(struct sock
*sk
)
509 struct dn_scp
*scp
= DN_SK(sk
);
511 if (scp
->state
== DN_CC
)
512 dn_send_conn_conf(sk
, GFP_ATOMIC
);
517 void dn_send_conn_conf(struct sock
*sk
, gfp_t gfp
)
519 struct dn_scp
*scp
= DN_SK(sk
);
520 struct sk_buff
*skb
= NULL
;
521 struct nsp_conn_init_msg
*msg
;
522 __u8 len
= (__u8
)le16_to_cpu(scp
->conndata_out
.opt_optl
);
524 if ((skb
= dn_alloc_skb(sk
, 50 + len
, gfp
)) == NULL
)
527 msg
= (struct nsp_conn_init_msg
*)skb_put(skb
, sizeof(*msg
));
529 msg
->dstaddr
= scp
->addrrem
;
530 msg
->srcaddr
= scp
->addrloc
;
531 msg
->services
= scp
->services_loc
;
532 msg
->info
= scp
->info_loc
;
533 msg
->segsize
= cpu_to_le16(scp
->segsize_loc
);
535 *skb_put(skb
,1) = len
;
538 memcpy(skb_put(skb
, len
), scp
->conndata_out
.opt_data
, len
);
543 scp
->persist
= dn_nsp_persist(sk
);
544 scp
->persist_fxn
= dn_nsp_retrans_conn_conf
;
548 static __inline__
void dn_nsp_do_disc(struct sock
*sk
, unsigned char msgflg
,
549 unsigned short reason
, gfp_t gfp
,
550 struct dst_entry
*dst
,
551 int ddl
, unsigned char *dd
, __le16 rem
, __le16 loc
)
553 struct sk_buff
*skb
= NULL
;
554 int size
= 7 + ddl
+ ((msgflg
== NSP_DISCINIT
) ? 1 : 0);
557 if ((dst
== NULL
) || (rem
== 0)) {
559 printk(KERN_DEBUG
"DECnet: dn_nsp_do_disc: BUG! Please report this to SteveW@ACM.org rem=%u dst=%p\n", le16_to_cpu(rem
), dst
);
563 if ((skb
= dn_alloc_skb(sk
, size
, gfp
)) == NULL
)
566 msg
= skb_put(skb
, size
);
568 *(__le16
*)msg
= rem
;
570 *(__le16
*)msg
= loc
;
572 *(__le16
*)msg
= cpu_to_le16(reason
);
574 if (msgflg
== NSP_DISCINIT
)
578 memcpy(msg
, dd
, ddl
);
582 * This doesn't go via the dn_nsp_send() function since we need
583 * to be able to send disc packets out which have no socket
586 skb_dst_set(skb
, dst_clone(dst
));
591 void dn_nsp_send_disc(struct sock
*sk
, unsigned char msgflg
,
592 unsigned short reason
, gfp_t gfp
)
594 struct dn_scp
*scp
= DN_SK(sk
);
597 if (msgflg
== NSP_DISCINIT
)
598 ddl
= le16_to_cpu(scp
->discdata_out
.opt_optl
);
601 reason
= le16_to_cpu(scp
->discdata_out
.opt_status
);
603 dn_nsp_do_disc(sk
, msgflg
, reason
, gfp
, sk
->sk_dst_cache
, ddl
,
604 scp
->discdata_out
.opt_data
, scp
->addrrem
, scp
->addrloc
);
608 void dn_nsp_return_disc(struct sk_buff
*skb
, unsigned char msgflg
,
609 unsigned short reason
)
611 struct dn_skb_cb
*cb
= DN_SKB_CB(skb
);
613 gfp_t gfp
= GFP_ATOMIC
;
615 dn_nsp_do_disc(NULL
, msgflg
, reason
, gfp
, skb_dst(skb
), ddl
,
616 NULL
, cb
->src_port
, cb
->dst_port
);
620 void dn_nsp_send_link(struct sock
*sk
, unsigned char lsflags
, char fcval
)
622 struct dn_scp
*scp
= DN_SK(sk
);
625 gfp_t gfp
= GFP_ATOMIC
;
627 if ((skb
= dn_alloc_skb(sk
, DN_MAX_NSP_DATA_HEADER
+ 2, gfp
)) == NULL
)
630 skb_reserve(skb
, DN_MAX_NSP_DATA_HEADER
);
631 ptr
= skb_put(skb
, 2);
632 DN_SKB_CB(skb
)->nsp_flags
= 0x10;
636 dn_nsp_queue_xmit(sk
, skb
, gfp
, 1);
638 scp
->persist
= dn_nsp_persist(sk
);
639 scp
->persist_fxn
= dn_nsp_xmit_timeout
;
642 static int dn_nsp_retrans_conninit(struct sock
*sk
)
644 struct dn_scp
*scp
= DN_SK(sk
);
646 if (scp
->state
== DN_CI
)
647 dn_nsp_send_conninit(sk
, NSP_RCI
);
652 void dn_nsp_send_conninit(struct sock
*sk
, unsigned char msgflg
)
654 struct dn_scp
*scp
= DN_SK(sk
);
655 struct nsp_conn_init_msg
*msg
;
657 unsigned char menuver
;
658 struct dn_skb_cb
*cb
;
659 unsigned char type
= 1;
660 gfp_t allocation
= (msgflg
== NSP_CI
) ? sk
->sk_allocation
: GFP_ATOMIC
;
661 struct sk_buff
*skb
= dn_alloc_skb(sk
, 200, allocation
);
667 msg
= (struct nsp_conn_init_msg
*)skb_put(skb
,sizeof(*msg
));
669 msg
->msgflg
= msgflg
;
670 msg
->dstaddr
= 0x0000; /* Remote Node will assign it*/
672 msg
->srcaddr
= scp
->addrloc
;
673 msg
->services
= scp
->services_loc
; /* Requested flow control */
674 msg
->info
= scp
->info_loc
; /* Version Number */
675 msg
->segsize
= cpu_to_le16(scp
->segsize_loc
); /* Max segment size */
677 if (scp
->peer
.sdn_objnum
)
680 skb_put(skb
, dn_sockaddr2username(&scp
->peer
,
681 skb_tail_pointer(skb
), type
));
682 skb_put(skb
, dn_sockaddr2username(&scp
->addr
,
683 skb_tail_pointer(skb
), 2));
685 menuver
= DN_MENUVER_ACC
| DN_MENUVER_USR
;
686 if (scp
->peer
.sdn_flags
& SDF_PROXY
)
687 menuver
|= DN_MENUVER_PRX
;
688 if (scp
->peer
.sdn_flags
& SDF_UICPROXY
)
689 menuver
|= DN_MENUVER_UIC
;
691 *skb_put(skb
, 1) = menuver
; /* Menu Version */
693 aux
= scp
->accessdata
.acc_userl
;
694 *skb_put(skb
, 1) = aux
;
696 memcpy(skb_put(skb
, aux
), scp
->accessdata
.acc_user
, aux
);
698 aux
= scp
->accessdata
.acc_passl
;
699 *skb_put(skb
, 1) = aux
;
701 memcpy(skb_put(skb
, aux
), scp
->accessdata
.acc_pass
, aux
);
703 aux
= scp
->accessdata
.acc_accl
;
704 *skb_put(skb
, 1) = aux
;
706 memcpy(skb_put(skb
, aux
), scp
->accessdata
.acc_acc
, aux
);
708 aux
= (__u8
)le16_to_cpu(scp
->conndata_out
.opt_optl
);
709 *skb_put(skb
, 1) = aux
;
711 memcpy(skb_put(skb
,aux
), scp
->conndata_out
.opt_data
, aux
);
713 scp
->persist
= dn_nsp_persist(sk
);
714 scp
->persist_fxn
= dn_nsp_retrans_conninit
;
716 cb
->rt_flags
= DN_RT_F_RQR
;
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