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>
54 #include <asm/system.h>
55 #include <linux/fcntl.h>
57 #include <linux/termios.h>
58 #include <linux/interrupt.h>
59 #include <linux/proc_fs.h>
60 #include <linux/stat.h>
61 #include <linux/init.h>
62 #include <linux/poll.h>
63 #include <linux/if_packet.h>
64 #include <net/neighbour.h>
68 #include <net/dn_nsp.h>
69 #include <net/dn_dev.h>
70 #include <net/dn_route.h>
73 static int nsp_backoff[NSP_MAXRXTSHIFT + 1] = { 1, 2, 4, 8, 16, 32, 64, 64, 64, 64, 64, 64, 64 };
75 static void dn_nsp_send(struct sk_buff *skb)
77 struct sock *sk = skb->sk;
78 struct dn_scp *scp = DN_SK(sk);
79 struct dst_entry *dst;
82 skb_reset_transport_header(skb);
85 dst = sk_dst_check(sk, 0);
93 memset(&fl, 0, sizeof(fl));
94 fl.oif = sk->sk_bound_dev_if;
95 fl.fld_src = dn_saddr2dn(&scp->addr);
96 fl.fld_dst = dn_saddr2dn(&scp->peer);
97 dn_sk_ports_copy(&fl, scp);
98 fl.proto = DNPROTO_NSP;
99 if (dn_route_output_sock(&sk->sk_dst_cache, &fl, sk, 0) == 0) {
100 dst = sk_dst_get(sk);
101 sk->sk_route_caps = dst->dev->features;
105 sk->sk_err = EHOSTUNREACH;
106 if (!sock_flag(sk, SOCK_DEAD))
107 sk->sk_state_change(sk);
112 * If sk == NULL, then we assume that we are supposed to be making
113 * a routing layer skb. If sk != NULL, then we are supposed to be
114 * creating an skb for the NSP layer.
116 * The eventual aim is for each socket to have a cached header size
117 * for its outgoing packets, and to set hdr from this when sk != NULL.
119 struct sk_buff *dn_alloc_skb(struct sock *sk, int size, gfp_t pri)
124 if ((skb = alloc_skb(size + hdr, pri)) == NULL)
127 skb->protocol = htons(ETH_P_DNA_RT);
128 skb->pkt_type = PACKET_OUTGOING;
131 skb_set_owner_w(skb, sk);
133 skb_reserve(skb, hdr);
139 * Calculate persist timer based upon the smoothed round
140 * trip time and the variance. Backoff according to the
141 * nsp_backoff[] array.
143 unsigned long dn_nsp_persist(struct sock *sk)
145 struct dn_scp *scp = DN_SK(sk);
147 unsigned long t = ((scp->nsp_srtt >> 2) + scp->nsp_rttvar) >> 1;
149 t *= nsp_backoff[scp->nsp_rxtshift];
152 if (t > (600*HZ)) t = (600*HZ);
154 if (scp->nsp_rxtshift < NSP_MAXRXTSHIFT)
157 /* printk(KERN_DEBUG "rxtshift %lu, t=%lu\n", scp->nsp_rxtshift, t); */
163 * This is called each time we get an estimate for the rtt
166 static void dn_nsp_rtt(struct sock *sk, long rtt)
168 struct dn_scp *scp = DN_SK(sk);
169 long srtt = (long)scp->nsp_srtt;
170 long rttvar = (long)scp->nsp_rttvar;
174 * If the jiffies clock flips over in the middle of timestamp
175 * gathering this value might turn out negative, so we make sure
176 * that is it always positive here.
181 * Add new rtt to smoothed average
183 delta = ((rtt << 3) - srtt);
184 srtt += (delta >> 3);
186 scp->nsp_srtt = (unsigned long)srtt;
191 * Add new rtt varience to smoothed varience
194 rttvar += ((((delta>0)?(delta):(-delta)) - rttvar) >> 2);
196 scp->nsp_rttvar = (unsigned long)rttvar;
200 /* printk(KERN_DEBUG "srtt=%lu rttvar=%lu\n", scp->nsp_srtt, scp->nsp_rttvar); */
204 * dn_nsp_clone_and_send - Send a data packet by cloning it
205 * @skb: The packet to clone and transmit
206 * @gfp: memory allocation flag
208 * Clone a queued data or other data packet and transmit it.
210 * Returns: The number of times the packet has been sent previously
212 static inline unsigned dn_nsp_clone_and_send(struct sk_buff *skb,
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 __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++ = dn_htons(acknum);
330 *ptr++ = dn_htons(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++) = dn_htons(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, *list, *ack = NULL;
389 unsigned long reftime = cb->stamp;
390 unsigned long pkttime;
391 unsigned short xmit_count;
392 unsigned short segnum;
395 list = (struct sk_buff *)q;
396 while(list != skb2) {
397 struct dn_skb_cb *cb2 = DN_SKB_CB(skb2);
399 if (dn_before_or_equal(cb2->segnum, acknum))
402 /* printk(KERN_DEBUG "ack: %s %04x %04x\n", ack ? "ACK" : "SKIP", (int)cb2->segnum, (int)acknum); */
409 /* printk(KERN_DEBUG "check_xmit_queue: %04x, %d\n", acknum, cb2->xmit_count); */
411 /* Does _last_ packet acked have xmit_count > 1 */
413 /* Remember to wake up the sending process */
415 /* Keep various statistics */
416 pkttime = cb2->stamp;
417 xmit_count = cb2->xmit_count;
418 segnum = cb2->segnum;
419 /* Remove and drop ack'ed packet */
425 * We don't expect to see acknowledgements for packets we
428 WARN_ON(xmit_count == 0);
431 * If the packet has only been sent once, we can use it
432 * to calculate the RTT and also open the window a little
435 if (xmit_count == 1) {
436 if (dn_equal(segnum, acknum))
437 dn_nsp_rtt(sk, (long)(pkttime - reftime));
439 if (scp->snd_window < scp->max_window)
444 * Packet has been sent more than once. If this is the last
445 * packet to be acknowledged then we want to send the next
446 * packet in the send queue again (assumes the remote host does
447 * go-back-N error control).
459 void dn_nsp_send_data_ack(struct sock *sk)
461 struct sk_buff *skb = NULL;
463 if ((skb = dn_alloc_skb(sk, 9, GFP_ATOMIC)) == NULL)
467 dn_mk_ack_header(sk, skb, 0x04, 9, 0);
471 void dn_nsp_send_oth_ack(struct sock *sk)
473 struct sk_buff *skb = NULL;
475 if ((skb = dn_alloc_skb(sk, 9, GFP_ATOMIC)) == NULL)
479 dn_mk_ack_header(sk, skb, 0x14, 9, 1);
484 void dn_send_conn_ack (struct sock *sk)
486 struct dn_scp *scp = DN_SK(sk);
487 struct sk_buff *skb = NULL;
488 struct nsp_conn_ack_msg *msg;
490 if ((skb = dn_alloc_skb(sk, 3, sk->sk_allocation)) == NULL)
493 msg = (struct nsp_conn_ack_msg *)skb_put(skb, 3);
495 msg->dstaddr = scp->addrrem;
500 void dn_nsp_delayed_ack(struct sock *sk)
502 struct dn_scp *scp = DN_SK(sk);
504 if (scp->ackxmt_oth != scp->numoth_rcv)
505 dn_nsp_send_oth_ack(sk);
507 if (scp->ackxmt_dat != scp->numdat_rcv)
508 dn_nsp_send_data_ack(sk);
511 static int dn_nsp_retrans_conn_conf(struct sock *sk)
513 struct dn_scp *scp = DN_SK(sk);
515 if (scp->state == DN_CC)
516 dn_send_conn_conf(sk, GFP_ATOMIC);
521 void dn_send_conn_conf(struct sock *sk, gfp_t gfp)
523 struct dn_scp *scp = DN_SK(sk);
524 struct sk_buff *skb = NULL;
525 struct nsp_conn_init_msg *msg;
526 __u8 len = (__u8)dn_ntohs(scp->conndata_out.opt_optl);
528 if ((skb = dn_alloc_skb(sk, 50 + len, gfp)) == NULL)
531 msg = (struct nsp_conn_init_msg *)skb_put(skb, sizeof(*msg));
533 msg->dstaddr = scp->addrrem;
534 msg->srcaddr = scp->addrloc;
535 msg->services = scp->services_loc;
536 msg->info = scp->info_loc;
537 msg->segsize = dn_htons(scp->segsize_loc);
539 *skb_put(skb,1) = len;
542 memcpy(skb_put(skb, len), scp->conndata_out.opt_data, len);
547 scp->persist = dn_nsp_persist(sk);
548 scp->persist_fxn = dn_nsp_retrans_conn_conf;
552 static __inline__ void dn_nsp_do_disc(struct sock *sk, unsigned char msgflg,
553 unsigned short reason, gfp_t gfp,
554 struct dst_entry *dst,
555 int ddl, unsigned char *dd, __le16 rem, __le16 loc)
557 struct sk_buff *skb = NULL;
558 int size = 7 + ddl + ((msgflg == NSP_DISCINIT) ? 1 : 0);
561 if ((dst == NULL) || (rem == 0)) {
563 printk(KERN_DEBUG "DECnet: dn_nsp_do_disc: BUG! Please report this to SteveW@ACM.org rem=%u dst=%p\n", dn_ntohs(rem), dst);
567 if ((skb = dn_alloc_skb(sk, size, gfp)) == NULL)
570 msg = skb_put(skb, size);
572 *(__le16 *)msg = rem;
574 *(__le16 *)msg = loc;
576 *(__le16 *)msg = dn_htons(reason);
578 if (msgflg == NSP_DISCINIT)
582 memcpy(msg, dd, ddl);
586 * This doesn't go via the dn_nsp_send() function since we need
587 * to be able to send disc packets out which have no socket
590 skb->dst = dst_clone(dst);
595 void dn_nsp_send_disc(struct sock *sk, unsigned char msgflg,
596 unsigned short reason, gfp_t gfp)
598 struct dn_scp *scp = DN_SK(sk);
601 if (msgflg == NSP_DISCINIT)
602 ddl = dn_ntohs(scp->discdata_out.opt_optl);
605 reason = dn_ntohs(scp->discdata_out.opt_status);
607 dn_nsp_do_disc(sk, msgflg, reason, gfp, sk->sk_dst_cache, ddl,
608 scp->discdata_out.opt_data, scp->addrrem, scp->addrloc);
612 void dn_nsp_return_disc(struct sk_buff *skb, unsigned char msgflg,
613 unsigned short reason)
615 struct dn_skb_cb *cb = DN_SKB_CB(skb);
617 gfp_t gfp = GFP_ATOMIC;
619 dn_nsp_do_disc(NULL, msgflg, reason, gfp, skb->dst, ddl,
620 NULL, cb->src_port, cb->dst_port);
624 void dn_nsp_send_link(struct sock *sk, unsigned char lsflags, char fcval)
626 struct dn_scp *scp = DN_SK(sk);
629 gfp_t gfp = GFP_ATOMIC;
631 if ((skb = dn_alloc_skb(sk, DN_MAX_NSP_DATA_HEADER + 2, gfp)) == NULL)
634 skb_reserve(skb, DN_MAX_NSP_DATA_HEADER);
635 ptr = skb_put(skb, 2);
636 DN_SKB_CB(skb)->nsp_flags = 0x10;
640 dn_nsp_queue_xmit(sk, skb, gfp, 1);
642 scp->persist = dn_nsp_persist(sk);
643 scp->persist_fxn = dn_nsp_xmit_timeout;
646 static int dn_nsp_retrans_conninit(struct sock *sk)
648 struct dn_scp *scp = DN_SK(sk);
650 if (scp->state == DN_CI)
651 dn_nsp_send_conninit(sk, NSP_RCI);
656 void dn_nsp_send_conninit(struct sock *sk, unsigned char msgflg)
658 struct dn_scp *scp = DN_SK(sk);
659 struct nsp_conn_init_msg *msg;
661 unsigned char menuver;
662 struct dn_skb_cb *cb;
663 unsigned char type = 1;
664 gfp_t allocation = (msgflg == NSP_CI) ? sk->sk_allocation : GFP_ATOMIC;
665 struct sk_buff *skb = dn_alloc_skb(sk, 200, allocation);
671 msg = (struct nsp_conn_init_msg *)skb_put(skb,sizeof(*msg));
673 msg->msgflg = msgflg;
674 msg->dstaddr = 0x0000; /* Remote Node will assign it*/
676 msg->srcaddr = scp->addrloc;
677 msg->services = scp->services_loc; /* Requested flow control */
678 msg->info = scp->info_loc; /* Version Number */
679 msg->segsize = dn_htons(scp->segsize_loc); /* Max segment size */
681 if (scp->peer.sdn_objnum)
684 skb_put(skb, dn_sockaddr2username(&scp->peer,
685 skb_tail_pointer(skb), type));
686 skb_put(skb, dn_sockaddr2username(&scp->addr,
687 skb_tail_pointer(skb), 2));
689 menuver = DN_MENUVER_ACC | DN_MENUVER_USR;
690 if (scp->peer.sdn_flags & SDF_PROXY)
691 menuver |= DN_MENUVER_PRX;
692 if (scp->peer.sdn_flags & SDF_UICPROXY)
693 menuver |= DN_MENUVER_UIC;
695 *skb_put(skb, 1) = menuver; /* Menu Version */
697 aux = scp->accessdata.acc_userl;
698 *skb_put(skb, 1) = aux;
700 memcpy(skb_put(skb, aux), scp->accessdata.acc_user, aux);
702 aux = scp->accessdata.acc_passl;
703 *skb_put(skb, 1) = aux;
705 memcpy(skb_put(skb, aux), scp->accessdata.acc_pass, aux);
707 aux = scp->accessdata.acc_accl;
708 *skb_put(skb, 1) = aux;
710 memcpy(skb_put(skb, aux), scp->accessdata.acc_acc, aux);
712 aux = (__u8)dn_ntohs(scp->conndata_out.opt_optl);
713 *skb_put(skb, 1) = aux;
715 memcpy(skb_put(skb,aux), scp->conndata_out.opt_data, aux);
717 scp->persist = dn_nsp_persist(sk);
718 scp->persist_fxn = dn_nsp_retrans_conninit;
720 cb->rt_flags = DN_RT_F_RQR;