2 * DECnet An implementation of the DECnet protocol suite for the LINUX
3 * operating system. DECnet is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
6 * DECnet Network Services Protocol (Input)
8 * Author: Eduardo Marcelo Serrat <emserrat@geocities.com>
12 * Steve Whitehouse: Split into dn_nsp_in.c and dn_nsp_out.c from
14 * Steve Whitehouse: Updated to work with my new routing architecture.
15 * Steve Whitehouse: Add changes from Eduardo Serrat's patches.
16 * Steve Whitehouse: Put all ack handling code in a common routine.
17 * Steve Whitehouse: Put other common bits into dn_nsp_rx()
18 * Steve Whitehouse: More checks on skb->len to catch bogus packets
19 * Fixed various race conditions and possible nasties.
20 * Steve Whitehouse: Now handles returned conninit frames.
21 * David S. Miller: New socket locking
22 * Steve Whitehouse: Fixed lockup when socket filtering was enabled.
23 * Paul Koning: Fix to push CC sockets into RUN when acks are
26 * Patrick Caulfield: Checking conninits for correctness & sending of error
28 * Steve Whitehouse: Added backlog congestion level return codes.
30 * Steve Whitehouse: Added flow control support (outbound)
31 * Steve Whitehouse: Prepare for nonlinear skbs
34 /******************************************************************************
35 (c) 1995-1998 E.M. Serrat emserrat@geocities.com
37 This program is free software; you can redistribute it and/or modify
38 it under the terms of the GNU General Public License as published by
39 the Free Software Foundation; either version 2 of the License, or
42 This program is distributed in the hope that it will be useful,
43 but WITHOUT ANY WARRANTY; without even the implied warranty of
44 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
45 GNU General Public License for more details.
46 *******************************************************************************/
48 #include <linux/errno.h>
49 #include <linux/types.h>
50 #include <linux/socket.h>
52 #include <linux/kernel.h>
53 #include <linux/timer.h>
54 #include <linux/string.h>
55 #include <linux/sockios.h>
56 #include <linux/net.h>
57 #include <linux/netdevice.h>
58 #include <linux/inet.h>
59 #include <linux/route.h>
60 #include <linux/slab.h>
62 #include <net/tcp_states.h>
63 #include <asm/system.h>
64 #include <linux/fcntl.h>
66 #include <linux/termios.h>
67 #include <linux/interrupt.h>
68 #include <linux/proc_fs.h>
69 #include <linux/stat.h>
70 #include <linux/init.h>
71 #include <linux/poll.h>
72 #include <linux/netfilter_decnet.h>
73 #include <net/neighbour.h>
76 #include <net/dn_nsp.h>
77 #include <net/dn_dev.h>
78 #include <net/dn_route.h>
80 extern int decnet_log_martians;
82 static void dn_log_martian(struct sk_buff *skb, const char *msg)
84 if (decnet_log_martians && net_ratelimit()) {
85 char *devname = skb->dev ? skb->dev->name : "???";
86 struct dn_skb_cb *cb = DN_SKB_CB(skb);
87 printk(KERN_INFO "DECnet: Martian packet (%s) dev=%s src=0x%04hx dst=0x%04hx srcport=0x%04hx dstport=0x%04hx\n",
88 msg, devname, le16_to_cpu(cb->src), le16_to_cpu(cb->dst),
89 le16_to_cpu(cb->src_port), le16_to_cpu(cb->dst_port));
94 * For this function we've flipped the cross-subchannel bit
95 * if the message is an otherdata or linkservice message. Thus
96 * we can use it to work out what to update.
98 static void dn_ack(struct sock *sk, struct sk_buff *skb, unsigned short ack)
100 struct dn_scp *scp = DN_SK(sk);
101 unsigned short type = ((ack >> 12) & 0x0003);
105 case 0: /* ACK - Data */
106 if (dn_after(ack, scp->ackrcv_dat)) {
107 scp->ackrcv_dat = ack & 0x0fff;
108 wakeup |= dn_nsp_check_xmit_queue(sk, skb, &scp->data_xmit_queue, ack);
111 case 1: /* NAK - Data */
113 case 2: /* ACK - OtherData */
114 if (dn_after(ack, scp->ackrcv_oth)) {
115 scp->ackrcv_oth = ack & 0x0fff;
116 wakeup |= dn_nsp_check_xmit_queue(sk, skb, &scp->other_xmit_queue, ack);
119 case 3: /* NAK - OtherData */
123 if (wakeup && !sock_flag(sk, SOCK_DEAD))
124 sk->sk_state_change(sk);
128 * This function is a universal ack processor.
130 static int dn_process_ack(struct sock *sk, struct sk_buff *skb, int oth)
132 __le16 *ptr = (__le16 *)skb->data;
139 if ((ack = le16_to_cpu(*ptr)) & 0x8000) {
143 if ((ack & 0x4000) == 0) {
146 dn_ack(sk, skb, ack);
153 if ((ack = le16_to_cpu(*ptr)) & 0x8000) {
156 if ((ack & 0x4000) == 0) {
159 dn_ack(sk, skb, ack);
168 * dn_check_idf - Check an image data field format is correct.
169 * @pptr: Pointer to pointer to image data
170 * @len: Pointer to length of image data
171 * @max: The maximum allowed length of the data in the image data field
172 * @follow_on: Check that this many bytes exist beyond the end of the image data
174 * Returns: 0 if ok, -1 on error
176 static inline int dn_check_idf(unsigned char **pptr, int *len, unsigned char max, unsigned char follow_on)
178 unsigned char *ptr = *pptr;
179 unsigned char flen = *ptr++;
184 if ((flen + follow_on) > *len)
193 * Table of reason codes to pass back to node which sent us a badly
194 * formed message, plus text messages for the log. A zero entry in
195 * the reason field means "don't reply" otherwise a disc init is sent with
196 * the specified reason code.
199 unsigned short reason;
202 { 0, "CI: Truncated message" },
203 { NSP_REASON_ID, "CI: Destination username error" },
204 { NSP_REASON_ID, "CI: Destination username type" },
205 { NSP_REASON_US, "CI: Source username error" },
206 { 0, "CI: Truncated at menuver" },
207 { 0, "CI: Truncated before access or user data" },
208 { NSP_REASON_IO, "CI: Access data format error" },
209 { NSP_REASON_IO, "CI: User data format error" }
213 * This function uses a slightly different lookup method
214 * to find its sockets, since it searches on object name/number
215 * rather than port numbers. Various tests are done to ensure that
216 * the incoming data is in the correct format before it is queued to
219 static struct sock *dn_find_listener(struct sk_buff *skb, unsigned short *reason)
221 struct dn_skb_cb *cb = DN_SKB_CB(skb);
222 struct nsp_conn_init_msg *msg = (struct nsp_conn_init_msg *)skb->data;
223 struct sockaddr_dn dstaddr;
224 struct sockaddr_dn srcaddr;
225 unsigned char type = 0;
231 unsigned char menuver;
233 memset(&dstaddr, 0, sizeof(struct sockaddr_dn));
234 memset(&srcaddr, 0, sizeof(struct sockaddr_dn));
237 * 1. Decode & remove message header
239 cb->src_port = msg->srcaddr;
240 cb->dst_port = msg->dstaddr;
241 cb->services = msg->services;
242 cb->info = msg->info;
243 cb->segsize = le16_to_cpu(msg->segsize);
245 if (!pskb_may_pull(skb, sizeof(*msg)))
248 skb_pull(skb, sizeof(*msg));
254 * 2. Check destination end username format
256 dstlen = dn_username2sockaddr(ptr, len, &dstaddr, &type);
269 * 3. Check source end username format
271 srclen = dn_username2sockaddr(ptr, len, &srcaddr, &type);
287 * 4. Check that optional data actually exists if menuver says it does
290 if ((menuver & (DN_MENUVER_ACC | DN_MENUVER_USR)) && (len < 1))
294 * 5. Check optional access data format
297 if (menuver & DN_MENUVER_ACC) {
298 if (dn_check_idf(&ptr, &len, 39, 1))
300 if (dn_check_idf(&ptr, &len, 39, 1))
302 if (dn_check_idf(&ptr, &len, 39, (menuver & DN_MENUVER_USR) ? 1 : 0))
307 * 6. Check optional user data format
310 if (menuver & DN_MENUVER_USR) {
311 if (dn_check_idf(&ptr, &len, 16, 0))
316 * 7. Look up socket based on destination end username
318 return dn_sklist_find_listener(&dstaddr);
320 dn_log_martian(skb, ci_err_table[err].text);
321 *reason = ci_err_table[err].reason;
326 static void dn_nsp_conn_init(struct sock *sk, struct sk_buff *skb)
328 if (sk_acceptq_is_full(sk)) {
333 sk->sk_ack_backlog++;
334 skb_queue_tail(&sk->sk_receive_queue, skb);
335 sk->sk_state_change(sk);
338 static void dn_nsp_conn_conf(struct sock *sk, struct sk_buff *skb)
340 struct dn_skb_cb *cb = DN_SKB_CB(skb);
341 struct dn_scp *scp = DN_SK(sk);
348 cb->services = *ptr++;
350 cb->segsize = le16_to_cpu(*(__le16 *)ptr);
352 if ((scp->state == DN_CI) || (scp->state == DN_CD)) {
354 scp->addrrem = cb->src_port;
355 sk->sk_state = TCP_ESTABLISHED;
357 scp->services_rem = cb->services;
358 scp->info_rem = cb->info;
359 scp->segsize_rem = cb->segsize;
361 if ((scp->services_rem & NSP_FC_MASK) == NSP_FC_NONE)
362 scp->max_window = decnet_no_fc_max_cwnd;
365 u16 dlen = *skb->data;
366 if ((dlen <= 16) && (dlen <= skb->len)) {
367 scp->conndata_in.opt_optl = cpu_to_le16(dlen);
368 skb_copy_from_linear_data_offset(skb, 1,
369 scp->conndata_in.opt_data, dlen);
372 dn_nsp_send_link(sk, DN_NOCHANGE, 0);
373 if (!sock_flag(sk, SOCK_DEAD))
374 sk->sk_state_change(sk);
381 static void dn_nsp_conn_ack(struct sock *sk, struct sk_buff *skb)
383 struct dn_scp *scp = DN_SK(sk);
385 if (scp->state == DN_CI) {
393 static void dn_nsp_disc_init(struct sock *sk, struct sk_buff *skb)
395 struct dn_scp *scp = DN_SK(sk);
396 struct dn_skb_cb *cb = DN_SKB_CB(skb);
397 unsigned short reason;
402 reason = le16_to_cpu(*(__le16 *)skb->data);
405 scp->discdata_in.opt_status = cpu_to_le16(reason);
406 scp->discdata_in.opt_optl = 0;
407 memset(scp->discdata_in.opt_data, 0, 16);
410 u16 dlen = *skb->data;
411 if ((dlen <= 16) && (dlen <= skb->len)) {
412 scp->discdata_in.opt_optl = cpu_to_le16(dlen);
413 skb_copy_from_linear_data_offset(skb, 1, scp->discdata_in.opt_data, dlen);
417 scp->addrrem = cb->src_port;
418 sk->sk_state = TCP_CLOSE;
424 sk->sk_err = ECONNREFUSED;
427 sk->sk_shutdown |= SHUTDOWN_MASK;
435 if (!sock_flag(sk, SOCK_DEAD)) {
436 if (sk->sk_socket->state != SS_UNCONNECTED)
437 sk->sk_socket->state = SS_DISCONNECTING;
438 sk->sk_state_change(sk);
442 * It appears that its possible for remote machines to send disc
443 * init messages with no port identifier if we are in the CI and
444 * possibly also the CD state. Obviously we shouldn't reply with
445 * a message if we don't know what the end point is.
448 dn_nsp_send_disc(sk, NSP_DISCCONF, NSP_REASON_DC, GFP_ATOMIC);
450 scp->persist_fxn = dn_destroy_timer;
451 scp->persist = dn_nsp_persist(sk);
458 * disc_conf messages are also called no_resources or no_link
459 * messages depending upon the "reason" field.
461 static void dn_nsp_disc_conf(struct sock *sk, struct sk_buff *skb)
463 struct dn_scp *scp = DN_SK(sk);
464 unsigned short reason;
469 reason = le16_to_cpu(*(__le16 *)skb->data);
471 sk->sk_state = TCP_CLOSE;
478 if (reason == NSP_REASON_DC)
480 if (reason == NSP_REASON_NL)
487 sk->sk_shutdown |= SHUTDOWN_MASK;
492 if (!sock_flag(sk, SOCK_DEAD)) {
493 if (sk->sk_socket->state != SS_UNCONNECTED)
494 sk->sk_socket->state = SS_DISCONNECTING;
495 sk->sk_state_change(sk);
498 scp->persist_fxn = dn_destroy_timer;
499 scp->persist = dn_nsp_persist(sk);
505 static void dn_nsp_linkservice(struct sock *sk, struct sk_buff *skb)
507 struct dn_scp *scp = DN_SK(sk);
508 unsigned short segnum;
509 unsigned char lsflags;
512 char *ptr = skb->data;
513 unsigned char fctype = scp->services_rem & NSP_FC_MASK;
518 segnum = le16_to_cpu(*(__le16 *)ptr);
520 lsflags = *(unsigned char *)ptr++;
524 * Here we ignore erronous packets which should really
525 * should cause a connection abort. It is not critical
531 if (seq_next(scp->numoth_rcv, segnum)) {
532 seq_add(&scp->numoth_rcv, 1);
533 switch(lsflags & 0x04) { /* FCVAL INT */
534 case 0x00: /* Normal Request */
535 switch(lsflags & 0x03) { /* FCVAL MOD */
536 case 0x00: /* Request count */
538 unsigned char p_fcval = -fcval;
539 if ((scp->flowrem_dat > p_fcval) &&
540 (fctype == NSP_FC_SCMC)) {
541 scp->flowrem_dat -= p_fcval;
543 } else if (fcval > 0) {
544 scp->flowrem_dat += fcval;
548 case 0x01: /* Stop outgoing data */
549 scp->flowrem_sw = DN_DONTSEND;
551 case 0x02: /* Ok to start again */
552 scp->flowrem_sw = DN_SEND;
557 case 0x04: /* Interrupt Request */
559 scp->flowrem_oth += fcval;
564 if (wake_up && !sock_flag(sk, SOCK_DEAD))
565 sk->sk_state_change(sk);
568 dn_nsp_send_oth_ack(sk);
575 * Copy of sock_queue_rcv_skb (from sock.h) without
576 * bh_lock_sock() (its already held when this is called) which
577 * also allows data and other data to be queued to a socket.
579 static __inline__ int dn_queue_skb(struct sock *sk, struct sk_buff *skb, int sig, struct sk_buff_head *queue)
584 /* Cast skb->rcvbuf to unsigned... It's pointless, but reduces
585 number of warnings when compiling with -W --ANK
587 if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >=
588 (unsigned)sk->sk_rcvbuf) {
593 err = sk_filter(sk, skb);
598 skb_set_owner_r(skb, sk);
599 skb_queue_tail(queue, skb);
601 if (!sock_flag(sk, SOCK_DEAD))
602 sk->sk_data_ready(sk, skb_len);
607 static void dn_nsp_otherdata(struct sock *sk, struct sk_buff *skb)
609 struct dn_scp *scp = DN_SK(sk);
610 unsigned short segnum;
611 struct dn_skb_cb *cb = DN_SKB_CB(skb);
617 cb->segnum = segnum = le16_to_cpu(*(__le16 *)skb->data);
620 if (seq_next(scp->numoth_rcv, segnum)) {
622 if (dn_queue_skb(sk, skb, SIGURG, &scp->other_receive_queue) == 0) {
623 seq_add(&scp->numoth_rcv, 1);
624 scp->other_report = 0;
629 dn_nsp_send_oth_ack(sk);
635 static void dn_nsp_data(struct sock *sk, struct sk_buff *skb)
638 unsigned short segnum;
639 struct dn_skb_cb *cb = DN_SKB_CB(skb);
640 struct dn_scp *scp = DN_SK(sk);
645 cb->segnum = segnum = le16_to_cpu(*(__le16 *)skb->data);
648 if (seq_next(scp->numdat_rcv, segnum)) {
649 if (dn_queue_skb(sk, skb, SIGIO, &sk->sk_receive_queue) == 0) {
650 seq_add(&scp->numdat_rcv, 1);
654 if ((scp->flowloc_sw == DN_SEND) && dn_congested(sk)) {
655 scp->flowloc_sw = DN_DONTSEND;
656 dn_nsp_send_link(sk, DN_DONTSEND, 0);
660 dn_nsp_send_data_ack(sk);
667 * If one of our conninit messages is returned, this function
668 * deals with it. It puts the socket into the NO_COMMUNICATION
671 static void dn_returned_conn_init(struct sock *sk, struct sk_buff *skb)
673 struct dn_scp *scp = DN_SK(sk);
675 if (scp->state == DN_CI) {
677 sk->sk_state = TCP_CLOSE;
678 if (!sock_flag(sk, SOCK_DEAD))
679 sk->sk_state_change(sk);
685 static int dn_nsp_no_socket(struct sk_buff *skb, unsigned short reason)
687 struct dn_skb_cb *cb = DN_SKB_CB(skb);
688 int ret = NET_RX_DROP;
690 /* Must not reply to returned packets */
691 if (cb->rt_flags & DN_RT_F_RTS)
694 if ((reason != NSP_REASON_OK) && ((cb->nsp_flags & 0x0c) == 0x08)) {
695 switch(cb->nsp_flags & 0x70) {
697 case 0x60: /* (Retransmitted) Connect Init */
698 dn_nsp_return_disc(skb, NSP_DISCINIT, reason);
699 ret = NET_RX_SUCCESS;
701 case 0x20: /* Connect Confirm */
702 dn_nsp_return_disc(skb, NSP_DISCCONF, reason);
703 ret = NET_RX_SUCCESS;
713 static int dn_nsp_rx_packet(struct sk_buff *skb)
715 struct dn_skb_cb *cb = DN_SKB_CB(skb);
716 struct sock *sk = NULL;
717 unsigned char *ptr = (unsigned char *)skb->data;
718 unsigned short reason = NSP_REASON_NL;
720 if (!pskb_may_pull(skb, 2))
723 skb_reset_transport_header(skb);
724 cb->nsp_flags = *ptr++;
726 if (decnet_debug_level & 2)
727 printk(KERN_DEBUG "dn_nsp_rx: Message type 0x%02x\n", (int)cb->nsp_flags);
729 if (cb->nsp_flags & 0x83)
733 * Filter out conninits and useless packet types
735 if ((cb->nsp_flags & 0x0c) == 0x08) {
736 switch(cb->nsp_flags & 0x70) {
738 case 0x70: /* Reserved */
739 case 0x50: /* Reserved, Phase II node init */
743 if (unlikely(cb->rt_flags & DN_RT_F_RTS))
745 sk = dn_find_listener(skb, &reason);
750 if (!pskb_may_pull(skb, 3))
754 * Grab the destination address.
756 cb->dst_port = *(__le16 *)ptr;
761 * If not a connack, grab the source address too.
763 if (pskb_may_pull(skb, 5)) {
764 cb->src_port = *(__le16 *)ptr;
770 * Returned packets...
771 * Swap src & dst and look up in the normal way.
773 if (unlikely(cb->rt_flags & DN_RT_F_RTS)) {
774 __le16 tmp = cb->dst_port;
775 cb->dst_port = cb->src_port;
783 * Find the socket to which this skb is destined.
785 sk = dn_find_by_skb(skb);
788 struct dn_scp *scp = DN_SK(sk);
791 scp->nsp_rxtshift = 0;
794 * We linearize everything except data segments here.
796 if (cb->nsp_flags & ~0x60) {
797 if (unlikely(skb_linearize(skb)))
801 return sk_receive_skb(sk, skb, 0);
804 return dn_nsp_no_socket(skb, reason);
811 int dn_nsp_rx(struct sk_buff *skb)
813 return NF_HOOK(NFPROTO_DECNET, NF_DN_LOCAL_IN, skb, skb->dev, NULL,
818 * This is the main receive routine for sockets. It is called
819 * from the above when the socket is not busy, and also from
820 * sock_release() when there is a backlog queued up.
822 int dn_nsp_backlog_rcv(struct sock *sk, struct sk_buff *skb)
824 struct dn_scp *scp = DN_SK(sk);
825 struct dn_skb_cb *cb = DN_SKB_CB(skb);
827 if (cb->rt_flags & DN_RT_F_RTS) {
828 if (cb->nsp_flags == 0x18 || cb->nsp_flags == 0x68)
829 dn_returned_conn_init(sk, skb);
832 return NET_RX_SUCCESS;
838 if ((cb->nsp_flags & 0x0c) == 0x08) {
839 switch(cb->nsp_flags & 0x70) {
842 dn_nsp_conn_init(sk, skb);
845 dn_nsp_conn_conf(sk, skb);
848 dn_nsp_disc_init(sk, skb);
851 dn_nsp_disc_conf(sk, skb);
855 } else if (cb->nsp_flags == 0x24) {
857 * Special for connacks, 'cos they don't have
858 * ack data or ack otherdata info.
860 dn_nsp_conn_ack(sk, skb);
864 /* both data and ack frames can kick a CC socket into RUN */
865 if ((scp->state == DN_CC) && !sock_flag(sk, SOCK_DEAD)) {
867 sk->sk_state = TCP_ESTABLISHED;
868 sk->sk_state_change(sk);
871 if ((cb->nsp_flags & 0x1c) == 0)
873 if (cb->nsp_flags == 0x04)
877 * Read out ack data here, this applies equally
878 * to data, other data, link serivce and both
879 * ack data and ack otherdata.
881 dn_process_ack(sk, skb, other);
884 * If we've some sort of data here then call a
885 * suitable routine for dealing with it, otherwise
886 * the packet is an ack and can be discarded.
888 if ((cb->nsp_flags & 0x0c) == 0) {
890 if (scp->state != DN_RUN)
893 switch(cb->nsp_flags) {
895 dn_nsp_linkservice(sk, skb);
898 dn_nsp_otherdata(sk, skb);
901 dn_nsp_data(sk, skb);
904 } else { /* Ack, chuck it out here */
910 return NET_RX_SUCCESS;