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/sched.h>
47 #include <linux/timer.h>
48 #include <linux/string.h>
49 #include <linux/sockios.h>
50 #include <linux/net.h>
51 #include <linux/netdevice.h>
52 #include <linux/inet.h>
53 #include <linux/route.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
->h
.raw
= skb
->data
;
86 dst
= sk_dst_check(sk
, 0);
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
, int pri
)
125 if ((skb
= alloc_skb(size
+ hdr
, pri
)) == NULL
)
128 skb
->protocol
= __constant_htons(ETH_P_DNA_RT
);
129 skb
->pkt_type
= PACKET_OUTGOING
;
132 skb_set_owner_w(skb
, sk
);
134 skb_reserve(skb
, hdr
);
140 * Wrapper for the above, for allocs of data skbs. We try and get the
141 * whole size thats been asked for (plus 11 bytes of header). If this
142 * fails, then we try for any size over 16 bytes for SOCK_STREAMS.
144 struct sk_buff
*dn_alloc_send_skb(struct sock
*sk
, size_t *size
, int noblock
, long timeo
, int *err
)
148 struct sk_buff
*skb
= NULL
;
153 if (signal_pending(current
)) {
154 *err
= sock_intr_errno(timeo
);
158 if (sk
->sk_shutdown
& SEND_SHUTDOWN
) {
167 space
= sk
->sk_sndbuf
- atomic_read(&sk
->sk_wmem_alloc
);
170 if ((sk
->sk_socket
->type
== SOCK_STREAM
) &&
171 (space
>= (16 + 11)))
176 set_bit(SOCK_ASYNC_NOSPACE
, &sk
->sk_socket
->flags
);
182 clear_bit(SOCK_ASYNC_WAITDATA
, &sk
->sk_socket
->flags
);
185 if ((sk
->sk_sndbuf
- atomic_read(&sk
->sk_wmem_alloc
)) <
193 if ((skb
= dn_alloc_skb(sk
, len
, sk
->sk_allocation
)) == NULL
)
203 * Calculate persist timer based upon the smoothed round
204 * trip time and the variance. Backoff according to the
205 * nsp_backoff[] array.
207 unsigned long dn_nsp_persist(struct sock
*sk
)
209 struct dn_scp
*scp
= DN_SK(sk
);
211 unsigned long t
= ((scp
->nsp_srtt
>> 2) + scp
->nsp_rttvar
) >> 1;
213 t
*= nsp_backoff
[scp
->nsp_rxtshift
];
216 if (t
> (600*HZ
)) t
= (600*HZ
);
218 if (scp
->nsp_rxtshift
< NSP_MAXRXTSHIFT
)
221 /* printk(KERN_DEBUG "rxtshift %lu, t=%lu\n", scp->nsp_rxtshift, t); */
227 * This is called each time we get an estimate for the rtt
230 static void dn_nsp_rtt(struct sock
*sk
, long rtt
)
232 struct dn_scp
*scp
= DN_SK(sk
);
233 long srtt
= (long)scp
->nsp_srtt
;
234 long rttvar
= (long)scp
->nsp_rttvar
;
238 * If the jiffies clock flips over in the middle of timestamp
239 * gathering this value might turn out negative, so we make sure
240 * that is it always positive here.
245 * Add new rtt to smoothed average
247 delta
= ((rtt
<< 3) - srtt
);
248 srtt
+= (delta
>> 3);
250 scp
->nsp_srtt
= (unsigned long)srtt
;
255 * Add new rtt varience to smoothed varience
258 rttvar
+= ((((delta
>0)?(delta
):(-delta
)) - rttvar
) >> 2);
260 scp
->nsp_rttvar
= (unsigned long)rttvar
;
264 /* printk(KERN_DEBUG "srtt=%lu rttvar=%lu\n", scp->nsp_srtt, scp->nsp_rttvar); */
268 * dn_nsp_clone_and_send - Send a data packet by cloning it
269 * @skb: The packet to clone and transmit
270 * @gfp: memory allocation flag
272 * Clone a queued data or other data packet and transmit it.
274 * Returns: The number of times the packet has been sent previously
276 static inline unsigned dn_nsp_clone_and_send(struct sk_buff
*skb
, int gfp
)
278 struct dn_skb_cb
*cb
= DN_SKB_CB(skb
);
279 struct sk_buff
*skb2
;
282 if ((skb2
= skb_clone(skb
, gfp
)) != NULL
) {
283 ret
= cb
->xmit_count
;
294 * dn_nsp_output - Try and send something from socket queues
295 * @sk: The socket whose queues are to be investigated
296 * @gfp: The memory allocation flags
298 * Try and send the packet on the end of the data and other data queues.
299 * Other data gets priority over data, and if we retransmit a packet we
300 * reduce the window by dividing it in two.
303 void dn_nsp_output(struct sock
*sk
)
305 struct dn_scp
*scp
= DN_SK(sk
);
307 unsigned reduce_win
= 0;
310 * First we check for otherdata/linkservice messages
312 if ((skb
= skb_peek(&scp
->other_xmit_queue
)) != NULL
)
313 reduce_win
= dn_nsp_clone_and_send(skb
, GFP_ATOMIC
);
316 * If we may not send any data, we don't.
317 * If we are still trying to get some other data down the
318 * channel, we don't try and send any data.
320 if (reduce_win
|| (scp
->flowrem_sw
!= DN_SEND
))
323 if ((skb
= skb_peek(&scp
->data_xmit_queue
)) != NULL
)
324 reduce_win
= dn_nsp_clone_and_send(skb
, GFP_ATOMIC
);
327 * If we've sent any frame more than once, we cut the
328 * send window size in half. There is always a minimum
329 * window size of one available.
333 scp
->snd_window
>>= 1;
334 if (scp
->snd_window
< NSP_MIN_WINDOW
)
335 scp
->snd_window
= NSP_MIN_WINDOW
;
339 int dn_nsp_xmit_timeout(struct sock
*sk
)
341 struct dn_scp
*scp
= DN_SK(sk
);
345 if (skb_queue_len(&scp
->data_xmit_queue
) || skb_queue_len(&scp
->other_xmit_queue
))
346 scp
->persist
= dn_nsp_persist(sk
);
351 static inline unsigned char *dn_mk_common_header(struct dn_scp
*scp
, struct sk_buff
*skb
, unsigned char msgflag
, int len
)
353 unsigned char *ptr
= skb_push(skb
, len
);
358 *((unsigned short *)ptr
) = scp
->addrrem
;
360 *((unsigned short *)ptr
) = scp
->addrloc
;
365 static unsigned short *dn_mk_ack_header(struct sock
*sk
, struct sk_buff
*skb
, unsigned char msgflag
, int hlen
, int other
)
367 struct dn_scp
*scp
= DN_SK(sk
);
368 unsigned short acknum
= scp
->numdat_rcv
& 0x0FFF;
369 unsigned short ackcrs
= scp
->numoth_rcv
& 0x0FFF;
374 scp
->ackxmt_dat
= acknum
;
375 scp
->ackxmt_oth
= ackcrs
;
379 /* If this is an "other data/ack" message, swap acknum and ackcrs */
381 unsigned short tmp
= acknum
;
386 /* Set "cross subchannel" bit in ackcrs */
389 ptr
= (unsigned short *)dn_mk_common_header(scp
, skb
, msgflag
, hlen
);
391 *ptr
++ = dn_htons(acknum
);
392 *ptr
++ = dn_htons(ackcrs
);
397 static unsigned short *dn_nsp_mk_data_header(struct sock
*sk
, struct sk_buff
*skb
, int oth
)
399 struct dn_scp
*scp
= DN_SK(sk
);
400 struct dn_skb_cb
*cb
= DN_SKB_CB(skb
);
401 unsigned short *ptr
= dn_mk_ack_header(sk
, skb
, cb
->nsp_flags
, 11, oth
);
404 cb
->segnum
= scp
->numoth
;
405 seq_add(&scp
->numoth
, 1);
407 cb
->segnum
= scp
->numdat
;
408 seq_add(&scp
->numdat
, 1);
410 *(ptr
++) = dn_htons(cb
->segnum
);
415 void dn_nsp_queue_xmit(struct sock
*sk
, struct sk_buff
*skb
, int gfp
, int oth
)
417 struct dn_scp
*scp
= DN_SK(sk
);
418 struct dn_skb_cb
*cb
= DN_SKB_CB(skb
);
419 unsigned long t
= ((scp
->nsp_srtt
>> 2) + scp
->nsp_rttvar
) >> 1;
422 dn_nsp_mk_data_header(sk
, skb
, oth
);
425 * Slow start: If we have been idle for more than
426 * one RTT, then reset window to min size.
428 if ((jiffies
- scp
->stamp
) > t
)
429 scp
->snd_window
= NSP_MIN_WINDOW
;
432 skb_queue_tail(&scp
->other_xmit_queue
, skb
);
434 skb_queue_tail(&scp
->data_xmit_queue
, skb
);
436 if (scp
->flowrem_sw
!= DN_SEND
)
439 dn_nsp_clone_and_send(skb
, gfp
);
443 int dn_nsp_check_xmit_queue(struct sock
*sk
, struct sk_buff
*skb
, struct sk_buff_head
*q
, unsigned short acknum
)
445 struct dn_skb_cb
*cb
= DN_SKB_CB(skb
);
446 struct dn_scp
*scp
= DN_SK(sk
);
447 struct sk_buff
*skb2
, *list
, *ack
= NULL
;
450 unsigned long reftime
= cb
->stamp
;
451 unsigned long pkttime
;
452 unsigned short xmit_count
;
453 unsigned short segnum
;
456 list
= (struct sk_buff
*)q
;
457 while(list
!= skb2
) {
458 struct dn_skb_cb
*cb2
= DN_SKB_CB(skb2
);
460 if (dn_before_or_equal(cb2
->segnum
, acknum
))
463 /* printk(KERN_DEBUG "ack: %s %04x %04x\n", ack ? "ACK" : "SKIP", (int)cb2->segnum, (int)acknum); */
470 /* printk(KERN_DEBUG "check_xmit_queue: %04x, %d\n", acknum, cb2->xmit_count); */
472 /* Does _last_ packet acked have xmit_count > 1 */
474 /* Remember to wake up the sending process */
476 /* Keep various statistics */
477 pkttime
= cb2
->stamp
;
478 xmit_count
= cb2
->xmit_count
;
479 segnum
= cb2
->segnum
;
480 /* Remove and drop ack'ed packet */
486 * We don't expect to see acknowledgements for packets we
489 WARN_ON(xmit_count
== 0);
492 * If the packet has only been sent once, we can use it
493 * to calculate the RTT and also open the window a little
496 if (xmit_count
== 1) {
497 if (dn_equal(segnum
, acknum
))
498 dn_nsp_rtt(sk
, (long)(pkttime
- reftime
));
500 if (scp
->snd_window
< scp
->max_window
)
505 * Packet has been sent more than once. If this is the last
506 * packet to be acknowledged then we want to send the next
507 * packet in the send queue again (assumes the remote host does
508 * go-back-N error control).
520 void dn_nsp_send_data_ack(struct sock
*sk
)
522 struct sk_buff
*skb
= NULL
;
524 if ((skb
= dn_alloc_skb(sk
, 9, GFP_ATOMIC
)) == NULL
)
528 dn_mk_ack_header(sk
, skb
, 0x04, 9, 0);
532 void dn_nsp_send_oth_ack(struct sock
*sk
)
534 struct sk_buff
*skb
= NULL
;
536 if ((skb
= dn_alloc_skb(sk
, 9, GFP_ATOMIC
)) == NULL
)
540 dn_mk_ack_header(sk
, skb
, 0x14, 9, 1);
545 void dn_send_conn_ack (struct sock
*sk
)
547 struct dn_scp
*scp
= DN_SK(sk
);
548 struct sk_buff
*skb
= NULL
;
549 struct nsp_conn_ack_msg
*msg
;
551 if ((skb
= dn_alloc_skb(sk
, 3, sk
->sk_allocation
)) == NULL
)
554 msg
= (struct nsp_conn_ack_msg
*)skb_put(skb
, 3);
556 msg
->dstaddr
= scp
->addrrem
;
561 void dn_nsp_delayed_ack(struct sock
*sk
)
563 struct dn_scp
*scp
= DN_SK(sk
);
565 if (scp
->ackxmt_oth
!= scp
->numoth_rcv
)
566 dn_nsp_send_oth_ack(sk
);
568 if (scp
->ackxmt_dat
!= scp
->numdat_rcv
)
569 dn_nsp_send_data_ack(sk
);
572 static int dn_nsp_retrans_conn_conf(struct sock
*sk
)
574 struct dn_scp
*scp
= DN_SK(sk
);
576 if (scp
->state
== DN_CC
)
577 dn_send_conn_conf(sk
, GFP_ATOMIC
);
582 void dn_send_conn_conf(struct sock
*sk
, int gfp
)
584 struct dn_scp
*scp
= DN_SK(sk
);
585 struct sk_buff
*skb
= NULL
;
586 struct nsp_conn_init_msg
*msg
;
587 unsigned char len
= scp
->conndata_out
.opt_optl
;
589 if ((skb
= dn_alloc_skb(sk
, 50 + scp
->conndata_out
.opt_optl
, gfp
)) == NULL
)
592 msg
= (struct nsp_conn_init_msg
*)skb_put(skb
, sizeof(*msg
));
594 msg
->dstaddr
= scp
->addrrem
;
595 msg
->srcaddr
= scp
->addrloc
;
596 msg
->services
= scp
->services_loc
;
597 msg
->info
= scp
->info_loc
;
598 msg
->segsize
= dn_htons(scp
->segsize_loc
);
600 *skb_put(skb
,1) = len
;
603 memcpy(skb_put(skb
, len
), scp
->conndata_out
.opt_data
, len
);
608 scp
->persist
= dn_nsp_persist(sk
);
609 scp
->persist_fxn
= dn_nsp_retrans_conn_conf
;
613 static __inline__
void dn_nsp_do_disc(struct sock
*sk
, unsigned char msgflg
,
614 unsigned short reason
, int gfp
, struct dst_entry
*dst
,
615 int ddl
, unsigned char *dd
, __u16 rem
, __u16 loc
)
617 struct sk_buff
*skb
= NULL
;
618 int size
= 7 + ddl
+ ((msgflg
== NSP_DISCINIT
) ? 1 : 0);
621 if ((dst
== NULL
) || (rem
== 0)) {
623 printk(KERN_DEBUG
"DECnet: dn_nsp_do_disc: BUG! Please report this to SteveW@ACM.org rem=%u dst=%p\n", (unsigned)rem
, dst
);
627 if ((skb
= dn_alloc_skb(sk
, size
, gfp
)) == NULL
)
630 msg
= skb_put(skb
, size
);
636 *(__u16
*)msg
= dn_htons(reason
);
638 if (msgflg
== NSP_DISCINIT
)
642 memcpy(msg
, dd
, ddl
);
646 * This doesn't go via the dn_nsp_send() function since we need
647 * to be able to send disc packets out which have no socket
650 skb
->dst
= dst_clone(dst
);
655 void dn_nsp_send_disc(struct sock
*sk
, unsigned char msgflg
,
656 unsigned short reason
, int gfp
)
658 struct dn_scp
*scp
= DN_SK(sk
);
661 if (msgflg
== NSP_DISCINIT
)
662 ddl
= scp
->discdata_out
.opt_optl
;
665 reason
= scp
->discdata_out
.opt_status
;
667 dn_nsp_do_disc(sk
, msgflg
, reason
, gfp
, sk
->sk_dst_cache
, ddl
,
668 scp
->discdata_out
.opt_data
, scp
->addrrem
, scp
->addrloc
);
672 void dn_nsp_return_disc(struct sk_buff
*skb
, unsigned char msgflg
,
673 unsigned short reason
)
675 struct dn_skb_cb
*cb
= DN_SKB_CB(skb
);
677 int gfp
= GFP_ATOMIC
;
679 dn_nsp_do_disc(NULL
, msgflg
, reason
, gfp
, skb
->dst
, ddl
,
680 NULL
, cb
->src_port
, cb
->dst_port
);
684 void dn_nsp_send_link(struct sock
*sk
, unsigned char lsflags
, char fcval
)
686 struct dn_scp
*scp
= DN_SK(sk
);
689 int gfp
= GFP_ATOMIC
;
691 if ((skb
= dn_alloc_skb(sk
, DN_MAX_NSP_DATA_HEADER
+ 2, gfp
)) == NULL
)
694 skb_reserve(skb
, DN_MAX_NSP_DATA_HEADER
);
695 ptr
= skb_put(skb
, 2);
696 DN_SKB_CB(skb
)->nsp_flags
= 0x10;
700 dn_nsp_queue_xmit(sk
, skb
, gfp
, 1);
702 scp
->persist
= dn_nsp_persist(sk
);
703 scp
->persist_fxn
= dn_nsp_xmit_timeout
;
706 static int dn_nsp_retrans_conninit(struct sock
*sk
)
708 struct dn_scp
*scp
= DN_SK(sk
);
710 if (scp
->state
== DN_CI
)
711 dn_nsp_send_conninit(sk
, NSP_RCI
);
716 void dn_nsp_send_conninit(struct sock
*sk
, unsigned char msgflg
)
718 struct dn_scp
*scp
= DN_SK(sk
);
719 struct nsp_conn_init_msg
*msg
;
721 unsigned char menuver
;
722 struct dn_skb_cb
*cb
;
723 unsigned char type
= 1;
724 int allocation
= (msgflg
== NSP_CI
) ? sk
->sk_allocation
: GFP_ATOMIC
;
725 struct sk_buff
*skb
= dn_alloc_skb(sk
, 200, allocation
);
731 msg
= (struct nsp_conn_init_msg
*)skb_put(skb
,sizeof(*msg
));
733 msg
->msgflg
= msgflg
;
734 msg
->dstaddr
= 0x0000; /* Remote Node will assign it*/
736 msg
->srcaddr
= scp
->addrloc
;
737 msg
->services
= scp
->services_loc
; /* Requested flow control */
738 msg
->info
= scp
->info_loc
; /* Version Number */
739 msg
->segsize
= dn_htons(scp
->segsize_loc
); /* Max segment size */
741 if (scp
->peer
.sdn_objnum
)
744 skb_put(skb
, dn_sockaddr2username(&scp
->peer
, skb
->tail
, type
));
745 skb_put(skb
, dn_sockaddr2username(&scp
->addr
, skb
->tail
, 2));
747 menuver
= DN_MENUVER_ACC
| DN_MENUVER_USR
;
748 if (scp
->peer
.sdn_flags
& SDF_PROXY
)
749 menuver
|= DN_MENUVER_PRX
;
750 if (scp
->peer
.sdn_flags
& SDF_UICPROXY
)
751 menuver
|= DN_MENUVER_UIC
;
753 *skb_put(skb
, 1) = menuver
; /* Menu Version */
755 aux
= scp
->accessdata
.acc_userl
;
756 *skb_put(skb
, 1) = aux
;
758 memcpy(skb_put(skb
, aux
), scp
->accessdata
.acc_user
, aux
);
760 aux
= scp
->accessdata
.acc_passl
;
761 *skb_put(skb
, 1) = aux
;
763 memcpy(skb_put(skb
, aux
), scp
->accessdata
.acc_pass
, aux
);
765 aux
= scp
->accessdata
.acc_accl
;
766 *skb_put(skb
, 1) = aux
;
768 memcpy(skb_put(skb
, aux
), scp
->accessdata
.acc_acc
, aux
);
770 aux
= scp
->conndata_out
.opt_optl
;
771 *skb_put(skb
, 1) = aux
;
773 memcpy(skb_put(skb
,aux
), scp
->conndata_out
.opt_data
, aux
);
775 scp
->persist
= dn_nsp_persist(sk
);
776 scp
->persist_fxn
= dn_nsp_retrans_conninit
;
778 cb
->rt_flags
= DN_RT_F_RQR
;