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_empty(&scp->data_xmit_queue) ||
346 !skb_queue_empty(&scp->other_xmit_queue))
347 scp->persist = dn_nsp_persist(sk);
352 static inline unsigned char *dn_mk_common_header(struct dn_scp *scp, struct sk_buff *skb, unsigned char msgflag, int len)
354 unsigned char *ptr = skb_push(skb, len);
359 *((unsigned short *)ptr) = scp->addrrem;
361 *((unsigned short *)ptr) = scp->addrloc;
366 static unsigned short *dn_mk_ack_header(struct sock *sk, struct sk_buff *skb, unsigned char msgflag, int hlen, int other)
368 struct dn_scp *scp = DN_SK(sk);
369 unsigned short acknum = scp->numdat_rcv & 0x0FFF;
370 unsigned short ackcrs = scp->numoth_rcv & 0x0FFF;
375 scp->ackxmt_dat = acknum;
376 scp->ackxmt_oth = ackcrs;
380 /* If this is an "other data/ack" message, swap acknum and ackcrs */
382 unsigned short tmp = acknum;
387 /* Set "cross subchannel" bit in ackcrs */
390 ptr = (unsigned short *)dn_mk_common_header(scp, skb, msgflag, hlen);
392 *ptr++ = dn_htons(acknum);
393 *ptr++ = dn_htons(ackcrs);
398 static unsigned short *dn_nsp_mk_data_header(struct sock *sk, struct sk_buff *skb, int oth)
400 struct dn_scp *scp = DN_SK(sk);
401 struct dn_skb_cb *cb = DN_SKB_CB(skb);
402 unsigned short *ptr = dn_mk_ack_header(sk, skb, cb->nsp_flags, 11, oth);
405 cb->segnum = scp->numoth;
406 seq_add(&scp->numoth, 1);
408 cb->segnum = scp->numdat;
409 seq_add(&scp->numdat, 1);
411 *(ptr++) = dn_htons(cb->segnum);
416 void dn_nsp_queue_xmit(struct sock *sk, struct sk_buff *skb, int gfp, int oth)
418 struct dn_scp *scp = DN_SK(sk);
419 struct dn_skb_cb *cb = DN_SKB_CB(skb);
420 unsigned long t = ((scp->nsp_srtt >> 2) + scp->nsp_rttvar) >> 1;
423 dn_nsp_mk_data_header(sk, skb, oth);
426 * Slow start: If we have been idle for more than
427 * one RTT, then reset window to min size.
429 if ((jiffies - scp->stamp) > t)
430 scp->snd_window = NSP_MIN_WINDOW;
433 skb_queue_tail(&scp->other_xmit_queue, skb);
435 skb_queue_tail(&scp->data_xmit_queue, skb);
437 if (scp->flowrem_sw != DN_SEND)
440 dn_nsp_clone_and_send(skb, gfp);
444 int dn_nsp_check_xmit_queue(struct sock *sk, struct sk_buff *skb, struct sk_buff_head *q, unsigned short acknum)
446 struct dn_skb_cb *cb = DN_SKB_CB(skb);
447 struct dn_scp *scp = DN_SK(sk);
448 struct sk_buff *skb2, *list, *ack = NULL;
451 unsigned long reftime = cb->stamp;
452 unsigned long pkttime;
453 unsigned short xmit_count;
454 unsigned short segnum;
457 list = (struct sk_buff *)q;
458 while(list != skb2) {
459 struct dn_skb_cb *cb2 = DN_SKB_CB(skb2);
461 if (dn_before_or_equal(cb2->segnum, acknum))
464 /* printk(KERN_DEBUG "ack: %s %04x %04x\n", ack ? "ACK" : "SKIP", (int)cb2->segnum, (int)acknum); */
471 /* printk(KERN_DEBUG "check_xmit_queue: %04x, %d\n", acknum, cb2->xmit_count); */
473 /* Does _last_ packet acked have xmit_count > 1 */
475 /* Remember to wake up the sending process */
477 /* Keep various statistics */
478 pkttime = cb2->stamp;
479 xmit_count = cb2->xmit_count;
480 segnum = cb2->segnum;
481 /* Remove and drop ack'ed packet */
487 * We don't expect to see acknowledgements for packets we
490 WARN_ON(xmit_count == 0);
493 * If the packet has only been sent once, we can use it
494 * to calculate the RTT and also open the window a little
497 if (xmit_count == 1) {
498 if (dn_equal(segnum, acknum))
499 dn_nsp_rtt(sk, (long)(pkttime - reftime));
501 if (scp->snd_window < scp->max_window)
506 * Packet has been sent more than once. If this is the last
507 * packet to be acknowledged then we want to send the next
508 * packet in the send queue again (assumes the remote host does
509 * go-back-N error control).
521 void dn_nsp_send_data_ack(struct sock *sk)
523 struct sk_buff *skb = NULL;
525 if ((skb = dn_alloc_skb(sk, 9, GFP_ATOMIC)) == NULL)
529 dn_mk_ack_header(sk, skb, 0x04, 9, 0);
533 void dn_nsp_send_oth_ack(struct sock *sk)
535 struct sk_buff *skb = NULL;
537 if ((skb = dn_alloc_skb(sk, 9, GFP_ATOMIC)) == NULL)
541 dn_mk_ack_header(sk, skb, 0x14, 9, 1);
546 void dn_send_conn_ack (struct sock *sk)
548 struct dn_scp *scp = DN_SK(sk);
549 struct sk_buff *skb = NULL;
550 struct nsp_conn_ack_msg *msg;
552 if ((skb = dn_alloc_skb(sk, 3, sk->sk_allocation)) == NULL)
555 msg = (struct nsp_conn_ack_msg *)skb_put(skb, 3);
557 msg->dstaddr = scp->addrrem;
562 void dn_nsp_delayed_ack(struct sock *sk)
564 struct dn_scp *scp = DN_SK(sk);
566 if (scp->ackxmt_oth != scp->numoth_rcv)
567 dn_nsp_send_oth_ack(sk);
569 if (scp->ackxmt_dat != scp->numdat_rcv)
570 dn_nsp_send_data_ack(sk);
573 static int dn_nsp_retrans_conn_conf(struct sock *sk)
575 struct dn_scp *scp = DN_SK(sk);
577 if (scp->state == DN_CC)
578 dn_send_conn_conf(sk, GFP_ATOMIC);
583 void dn_send_conn_conf(struct sock *sk, int gfp)
585 struct dn_scp *scp = DN_SK(sk);
586 struct sk_buff *skb = NULL;
587 struct nsp_conn_init_msg *msg;
588 unsigned char len = scp->conndata_out.opt_optl;
590 if ((skb = dn_alloc_skb(sk, 50 + scp->conndata_out.opt_optl, gfp)) == NULL)
593 msg = (struct nsp_conn_init_msg *)skb_put(skb, sizeof(*msg));
595 msg->dstaddr = scp->addrrem;
596 msg->srcaddr = scp->addrloc;
597 msg->services = scp->services_loc;
598 msg->info = scp->info_loc;
599 msg->segsize = dn_htons(scp->segsize_loc);
601 *skb_put(skb,1) = len;
604 memcpy(skb_put(skb, len), scp->conndata_out.opt_data, len);
609 scp->persist = dn_nsp_persist(sk);
610 scp->persist_fxn = dn_nsp_retrans_conn_conf;
614 static __inline__ void dn_nsp_do_disc(struct sock *sk, unsigned char msgflg,
615 unsigned short reason, int gfp, struct dst_entry *dst,
616 int ddl, unsigned char *dd, __u16 rem, __u16 loc)
618 struct sk_buff *skb = NULL;
619 int size = 7 + ddl + ((msgflg == NSP_DISCINIT) ? 1 : 0);
622 if ((dst == NULL) || (rem == 0)) {
624 printk(KERN_DEBUG "DECnet: dn_nsp_do_disc: BUG! Please report this to SteveW@ACM.org rem=%u dst=%p\n", (unsigned)rem, dst);
628 if ((skb = dn_alloc_skb(sk, size, gfp)) == NULL)
631 msg = skb_put(skb, size);
637 *(__u16 *)msg = dn_htons(reason);
639 if (msgflg == NSP_DISCINIT)
643 memcpy(msg, dd, ddl);
647 * This doesn't go via the dn_nsp_send() function since we need
648 * to be able to send disc packets out which have no socket
651 skb->dst = dst_clone(dst);
656 void dn_nsp_send_disc(struct sock *sk, unsigned char msgflg,
657 unsigned short reason, int gfp)
659 struct dn_scp *scp = DN_SK(sk);
662 if (msgflg == NSP_DISCINIT)
663 ddl = scp->discdata_out.opt_optl;
666 reason = scp->discdata_out.opt_status;
668 dn_nsp_do_disc(sk, msgflg, reason, gfp, sk->sk_dst_cache, ddl,
669 scp->discdata_out.opt_data, scp->addrrem, scp->addrloc);
673 void dn_nsp_return_disc(struct sk_buff *skb, unsigned char msgflg,
674 unsigned short reason)
676 struct dn_skb_cb *cb = DN_SKB_CB(skb);
678 int gfp = GFP_ATOMIC;
680 dn_nsp_do_disc(NULL, msgflg, reason, gfp, skb->dst, ddl,
681 NULL, cb->src_port, cb->dst_port);
685 void dn_nsp_send_link(struct sock *sk, unsigned char lsflags, char fcval)
687 struct dn_scp *scp = DN_SK(sk);
690 int gfp = GFP_ATOMIC;
692 if ((skb = dn_alloc_skb(sk, DN_MAX_NSP_DATA_HEADER + 2, gfp)) == NULL)
695 skb_reserve(skb, DN_MAX_NSP_DATA_HEADER);
696 ptr = skb_put(skb, 2);
697 DN_SKB_CB(skb)->nsp_flags = 0x10;
701 dn_nsp_queue_xmit(sk, skb, gfp, 1);
703 scp->persist = dn_nsp_persist(sk);
704 scp->persist_fxn = dn_nsp_xmit_timeout;
707 static int dn_nsp_retrans_conninit(struct sock *sk)
709 struct dn_scp *scp = DN_SK(sk);
711 if (scp->state == DN_CI)
712 dn_nsp_send_conninit(sk, NSP_RCI);
717 void dn_nsp_send_conninit(struct sock *sk, unsigned char msgflg)
719 struct dn_scp *scp = DN_SK(sk);
720 struct nsp_conn_init_msg *msg;
722 unsigned char menuver;
723 struct dn_skb_cb *cb;
724 unsigned char type = 1;
725 int allocation = (msgflg == NSP_CI) ? sk->sk_allocation : GFP_ATOMIC;
726 struct sk_buff *skb = dn_alloc_skb(sk, 200, allocation);
732 msg = (struct nsp_conn_init_msg *)skb_put(skb,sizeof(*msg));
734 msg->msgflg = msgflg;
735 msg->dstaddr = 0x0000; /* Remote Node will assign it*/
737 msg->srcaddr = scp->addrloc;
738 msg->services = scp->services_loc; /* Requested flow control */
739 msg->info = scp->info_loc; /* Version Number */
740 msg->segsize = dn_htons(scp->segsize_loc); /* Max segment size */
742 if (scp->peer.sdn_objnum)
745 skb_put(skb, dn_sockaddr2username(&scp->peer, skb->tail, type));
746 skb_put(skb, dn_sockaddr2username(&scp->addr, skb->tail, 2));
748 menuver = DN_MENUVER_ACC | DN_MENUVER_USR;
749 if (scp->peer.sdn_flags & SDF_PROXY)
750 menuver |= DN_MENUVER_PRX;
751 if (scp->peer.sdn_flags & SDF_UICPROXY)
752 menuver |= DN_MENUVER_UIC;
754 *skb_put(skb, 1) = menuver; /* Menu Version */
756 aux = scp->accessdata.acc_userl;
757 *skb_put(skb, 1) = aux;
759 memcpy(skb_put(skb, aux), scp->accessdata.acc_user, aux);
761 aux = scp->accessdata.acc_passl;
762 *skb_put(skb, 1) = aux;
764 memcpy(skb_put(skb, aux), scp->accessdata.acc_pass, aux);
766 aux = scp->accessdata.acc_accl;
767 *skb_put(skb, 1) = aux;
769 memcpy(skb_put(skb, aux), scp->accessdata.acc_acc, aux);
771 aux = scp->conndata_out.opt_optl;
772 *skb_put(skb, 1) = aux;
774 memcpy(skb_put(skb,aux), scp->conndata_out.opt_data, aux);
776 scp->persist = dn_nsp_persist(sk);
777 scp->persist_fxn = dn_nsp_retrans_conninit;
779 cb->rt_flags = DN_RT_F_RQR;