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 * 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, int gfp)
215 struct dn_skb_cb *cb = DN_SKB_CB(skb);
216 struct sk_buff *skb2;
219 if ((skb2 = skb_clone(skb, gfp)) != NULL) {
220 ret = cb->xmit_count;
231 * dn_nsp_output - Try and send something from socket queues
232 * @sk: The socket whose queues are to be investigated
233 * @gfp: The memory allocation flags
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 unsigned char *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 *((unsigned short *)ptr) = scp->addrrem;
298 *((unsigned short *)ptr) = scp->addrloc;
303 static unsigned short *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 = (unsigned short *)dn_mk_common_header(scp, skb, msgflag, hlen);
329 *ptr++ = dn_htons(acknum);
330 *ptr++ = dn_htons(ackcrs);
335 static unsigned short *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 unsigned short *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++) = dn_htons(cb->segnum);
353 void dn_nsp_queue_xmit(struct sock *sk, struct sk_buff *skb, int gfp, int oth)
355 struct dn_scp *scp = DN_SK(sk);
356 struct dn_skb_cb *cb = DN_SKB_CB(skb);
357 unsigned long t = ((scp->nsp_srtt >> 2) + scp->nsp_rttvar) >> 1;
360 dn_nsp_mk_data_header(sk, skb, oth);
363 * Slow start: If we have been idle for more than
364 * one RTT, then reset window to min size.
366 if ((jiffies - scp->stamp) > t)
367 scp->snd_window = NSP_MIN_WINDOW;
370 skb_queue_tail(&scp->other_xmit_queue, skb);
372 skb_queue_tail(&scp->data_xmit_queue, skb);
374 if (scp->flowrem_sw != DN_SEND)
377 dn_nsp_clone_and_send(skb, gfp);
381 int dn_nsp_check_xmit_queue(struct sock *sk, struct sk_buff *skb, struct sk_buff_head *q, unsigned short acknum)
383 struct dn_skb_cb *cb = DN_SKB_CB(skb);
384 struct dn_scp *scp = DN_SK(sk);
385 struct sk_buff *skb2, *list, *ack = NULL;
388 unsigned long reftime = cb->stamp;
389 unsigned long pkttime;
390 unsigned short xmit_count;
391 unsigned short segnum;
394 list = (struct sk_buff *)q;
395 while(list != skb2) {
396 struct dn_skb_cb *cb2 = DN_SKB_CB(skb2);
398 if (dn_before_or_equal(cb2->segnum, acknum))
401 /* printk(KERN_DEBUG "ack: %s %04x %04x\n", ack ? "ACK" : "SKIP", (int)cb2->segnum, (int)acknum); */
408 /* printk(KERN_DEBUG "check_xmit_queue: %04x, %d\n", acknum, cb2->xmit_count); */
410 /* Does _last_ packet acked have xmit_count > 1 */
412 /* Remember to wake up the sending process */
414 /* Keep various statistics */
415 pkttime = cb2->stamp;
416 xmit_count = cb2->xmit_count;
417 segnum = cb2->segnum;
418 /* Remove and drop ack'ed packet */
424 * We don't expect to see acknowledgements for packets we
427 WARN_ON(xmit_count == 0);
430 * If the packet has only been sent once, we can use it
431 * to calculate the RTT and also open the window a little
434 if (xmit_count == 1) {
435 if (dn_equal(segnum, acknum))
436 dn_nsp_rtt(sk, (long)(pkttime - reftime));
438 if (scp->snd_window < scp->max_window)
443 * Packet has been sent more than once. If this is the last
444 * packet to be acknowledged then we want to send the next
445 * packet in the send queue again (assumes the remote host does
446 * go-back-N error control).
458 void dn_nsp_send_data_ack(struct sock *sk)
460 struct sk_buff *skb = NULL;
462 if ((skb = dn_alloc_skb(sk, 9, GFP_ATOMIC)) == NULL)
466 dn_mk_ack_header(sk, skb, 0x04, 9, 0);
470 void dn_nsp_send_oth_ack(struct sock *sk)
472 struct sk_buff *skb = NULL;
474 if ((skb = dn_alloc_skb(sk, 9, GFP_ATOMIC)) == NULL)
478 dn_mk_ack_header(sk, skb, 0x14, 9, 1);
483 void dn_send_conn_ack (struct sock *sk)
485 struct dn_scp *scp = DN_SK(sk);
486 struct sk_buff *skb = NULL;
487 struct nsp_conn_ack_msg *msg;
489 if ((skb = dn_alloc_skb(sk, 3, sk->sk_allocation)) == NULL)
492 msg = (struct nsp_conn_ack_msg *)skb_put(skb, 3);
494 msg->dstaddr = scp->addrrem;
499 void dn_nsp_delayed_ack(struct sock *sk)
501 struct dn_scp *scp = DN_SK(sk);
503 if (scp->ackxmt_oth != scp->numoth_rcv)
504 dn_nsp_send_oth_ack(sk);
506 if (scp->ackxmt_dat != scp->numdat_rcv)
507 dn_nsp_send_data_ack(sk);
510 static int dn_nsp_retrans_conn_conf(struct sock *sk)
512 struct dn_scp *scp = DN_SK(sk);
514 if (scp->state == DN_CC)
515 dn_send_conn_conf(sk, GFP_ATOMIC);
520 void dn_send_conn_conf(struct sock *sk, int gfp)
522 struct dn_scp *scp = DN_SK(sk);
523 struct sk_buff *skb = NULL;
524 struct nsp_conn_init_msg *msg;
525 unsigned char len = scp->conndata_out.opt_optl;
527 if ((skb = dn_alloc_skb(sk, 50 + scp->conndata_out.opt_optl, gfp)) == NULL)
530 msg = (struct nsp_conn_init_msg *)skb_put(skb, sizeof(*msg));
532 msg->dstaddr = scp->addrrem;
533 msg->srcaddr = scp->addrloc;
534 msg->services = scp->services_loc;
535 msg->info = scp->info_loc;
536 msg->segsize = dn_htons(scp->segsize_loc);
538 *skb_put(skb,1) = len;
541 memcpy(skb_put(skb, len), scp->conndata_out.opt_data, len);
546 scp->persist = dn_nsp_persist(sk);
547 scp->persist_fxn = dn_nsp_retrans_conn_conf;
551 static __inline__ void dn_nsp_do_disc(struct sock *sk, unsigned char msgflg,
552 unsigned short reason, int gfp, struct dst_entry *dst,
553 int ddl, unsigned char *dd, __u16 rem, __u16 loc)
555 struct sk_buff *skb = NULL;
556 int size = 7 + ddl + ((msgflg == NSP_DISCINIT) ? 1 : 0);
559 if ((dst == NULL) || (rem == 0)) {
561 printk(KERN_DEBUG "DECnet: dn_nsp_do_disc: BUG! Please report this to SteveW@ACM.org rem=%u dst=%p\n", (unsigned)rem, dst);
565 if ((skb = dn_alloc_skb(sk, size, gfp)) == NULL)
568 msg = skb_put(skb, size);
574 *(__u16 *)msg = dn_htons(reason);
576 if (msgflg == NSP_DISCINIT)
580 memcpy(msg, dd, ddl);
584 * This doesn't go via the dn_nsp_send() function since we need
585 * to be able to send disc packets out which have no socket
588 skb->dst = dst_clone(dst);
593 void dn_nsp_send_disc(struct sock *sk, unsigned char msgflg,
594 unsigned short reason, int gfp)
596 struct dn_scp *scp = DN_SK(sk);
599 if (msgflg == NSP_DISCINIT)
600 ddl = scp->discdata_out.opt_optl;
603 reason = scp->discdata_out.opt_status;
605 dn_nsp_do_disc(sk, msgflg, reason, gfp, sk->sk_dst_cache, ddl,
606 scp->discdata_out.opt_data, scp->addrrem, scp->addrloc);
610 void dn_nsp_return_disc(struct sk_buff *skb, unsigned char msgflg,
611 unsigned short reason)
613 struct dn_skb_cb *cb = DN_SKB_CB(skb);
615 int gfp = GFP_ATOMIC;
617 dn_nsp_do_disc(NULL, msgflg, reason, gfp, skb->dst, ddl,
618 NULL, cb->src_port, cb->dst_port);
622 void dn_nsp_send_link(struct sock *sk, unsigned char lsflags, char fcval)
624 struct dn_scp *scp = DN_SK(sk);
627 int gfp = GFP_ATOMIC;
629 if ((skb = dn_alloc_skb(sk, DN_MAX_NSP_DATA_HEADER + 2, gfp)) == NULL)
632 skb_reserve(skb, DN_MAX_NSP_DATA_HEADER);
633 ptr = skb_put(skb, 2);
634 DN_SKB_CB(skb)->nsp_flags = 0x10;
638 dn_nsp_queue_xmit(sk, skb, gfp, 1);
640 scp->persist = dn_nsp_persist(sk);
641 scp->persist_fxn = dn_nsp_xmit_timeout;
644 static int dn_nsp_retrans_conninit(struct sock *sk)
646 struct dn_scp *scp = DN_SK(sk);
648 if (scp->state == DN_CI)
649 dn_nsp_send_conninit(sk, NSP_RCI);
654 void dn_nsp_send_conninit(struct sock *sk, unsigned char msgflg)
656 struct dn_scp *scp = DN_SK(sk);
657 struct nsp_conn_init_msg *msg;
659 unsigned char menuver;
660 struct dn_skb_cb *cb;
661 unsigned char type = 1;
662 int allocation = (msgflg == NSP_CI) ? sk->sk_allocation : GFP_ATOMIC;
663 struct sk_buff *skb = dn_alloc_skb(sk, 200, allocation);
669 msg = (struct nsp_conn_init_msg *)skb_put(skb,sizeof(*msg));
671 msg->msgflg = msgflg;
672 msg->dstaddr = 0x0000; /* Remote Node will assign it*/
674 msg->srcaddr = scp->addrloc;
675 msg->services = scp->services_loc; /* Requested flow control */
676 msg->info = scp->info_loc; /* Version Number */
677 msg->segsize = dn_htons(scp->segsize_loc); /* Max segment size */
679 if (scp->peer.sdn_objnum)
682 skb_put(skb, dn_sockaddr2username(&scp->peer, skb->tail, type));
683 skb_put(skb, dn_sockaddr2username(&scp->addr, skb->tail, 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 = 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;