/* * DECnet An implementation of the DECnet protocol suite for the LINUX * operating system. DECnet is implemented using the BSD Socket * interface as the means of communication with the user level. * * DECnet Network Services Protocol (Output) * * Author: Eduardo Marcelo Serrat * * Changes: * * Steve Whitehouse: Split into dn_nsp_in.c and dn_nsp_out.c from * original dn_nsp.c. * Steve Whitehouse: Updated to work with my new routing architecture. * Steve Whitehouse: Added changes from Eduardo Serrat's patches. * Steve Whitehouse: Now conninits have the "return" bit set. * Steve Whitehouse: Fixes to check alloc'd skbs are non NULL! * Moved output state machine into one function * Steve Whitehouse: New output state machine * Paul Koning: Connect Confirm message fix. * Eduardo Serrat: Fix to stop dn_nsp_do_disc() sending malformed packets. * Steve Whitehouse: dn_nsp_output() and friends needed a spring clean * Steve Whitehouse: Moved dn_nsp_send() in here from route.h */ /****************************************************************************** (c) 1995-1998 E.M. Serrat emserrat@geocities.com This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. *******************************************************************************/ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include static int nsp_backoff[NSP_MAXRXTSHIFT + 1] = { 1, 2, 4, 8, 16, 32, 64, 64, 64, 64, 64, 64, 64 }; static void dn_nsp_send(struct sk_buff *skb) { struct sock *sk = skb->sk; struct dn_scp *scp = DN_SK(sk); struct dst_entry *dst; struct flowidn fld; skb_reset_transport_header(skb); scp->stamp = jiffies; dst = sk_dst_check(sk, 0); if (dst) { try_again: skb_dst_set(skb, dst); dst_output(skb); return; } memset(&fld, 0, sizeof(fld)); fld.flowidn_oif = sk->sk_bound_dev_if; fld.saddr = dn_saddr2dn(&scp->addr); fld.daddr = dn_saddr2dn(&scp->peer); dn_sk_ports_copy(&fld, scp); fld.flowidn_proto = DNPROTO_NSP; if (dn_route_output_sock(&sk->sk_dst_cache, &fld, sk, 0) == 0) { dst = sk_dst_get(sk); sk->sk_route_caps = dst->dev->features; goto try_again; } sk->sk_err = EHOSTUNREACH; if (!sock_flag(sk, SOCK_DEAD)) sk->sk_state_change(sk); } /* * If sk == NULL, then we assume that we are supposed to be making * a routing layer skb. If sk != NULL, then we are supposed to be * creating an skb for the NSP layer. * * The eventual aim is for each socket to have a cached header size * for its outgoing packets, and to set hdr from this when sk != NULL. */ struct sk_buff *dn_alloc_skb(struct sock *sk, int size, gfp_t pri) { struct sk_buff *skb; int hdr = 64; if ((skb = alloc_skb(size + hdr, pri)) == NULL) return NULL; skb->protocol = htons(ETH_P_DNA_RT); skb->pkt_type = PACKET_OUTGOING; if (sk) skb_set_owner_w(skb, sk); skb_reserve(skb, hdr); return skb; } /* * Calculate persist timer based upon the smoothed round * trip time and the variance. Backoff according to the * nsp_backoff[] array. */ unsigned long dn_nsp_persist(struct sock *sk) { struct dn_scp *scp = DN_SK(sk); unsigned long t = ((scp->nsp_srtt >> 2) + scp->nsp_rttvar) >> 1; t *= nsp_backoff[scp->nsp_rxtshift]; if (t < HZ) t = HZ; if (t > (600*HZ)) t = (600*HZ); if (scp->nsp_rxtshift < NSP_MAXRXTSHIFT) scp->nsp_rxtshift++; /* printk(KERN_DEBUG "rxtshift %lu, t=%lu\n", scp->nsp_rxtshift, t); */ return t; } /* * This is called each time we get an estimate for the rtt * on the link. */ static void dn_nsp_rtt(struct sock *sk, long rtt) { struct dn_scp *scp = DN_SK(sk); long srtt = (long)scp->nsp_srtt; long rttvar = (long)scp->nsp_rttvar; long delta; /* * If the jiffies clock flips over in the middle of timestamp * gathering this value might turn out negative, so we make sure * that is it always positive here. */ if (rtt < 0) rtt = -rtt; /* * Add new rtt to smoothed average */ delta = ((rtt << 3) - srtt); srtt += (delta >> 3); if (srtt >= 1) scp->nsp_srtt = (unsigned long)srtt; else scp->nsp_srtt = 1; /* * Add new rtt varience to smoothed varience */ delta >>= 1; rttvar += ((((delta>0)?(delta):(-delta)) - rttvar) >> 2); if (rttvar >= 1) scp->nsp_rttvar = (unsigned long)rttvar; else scp->nsp_rttvar = 1; /* printk(KERN_DEBUG "srtt=%lu rttvar=%lu\n", scp->nsp_srtt, scp->nsp_rttvar); */ } /** * dn_nsp_clone_and_send - Send a data packet by cloning it * @skb: The packet to clone and transmit * @gfp: memory allocation flag * * Clone a queued data or other data packet and transmit it. * * Returns: The number of times the packet has been sent previously */ static inline unsigned dn_nsp_clone_and_send(struct sk_buff *skb, gfp_t gfp) { struct dn_skb_cb *cb = DN_SKB_CB(skb); struct sk_buff *skb2; int ret = 0; if ((skb2 = skb_clone(skb, gfp)) != NULL) { ret = cb->xmit_count; cb->xmit_count++; cb->stamp = jiffies; skb2->sk = skb->sk; dn_nsp_send(skb2); } return ret; } /** * dn_nsp_output - Try and send something from socket queues * @sk: The socket whose queues are to be investigated * * Try and send the packet on the end of the data and other data queues. * Other data gets priority over data, and if we retransmit a packet we * reduce the window by dividing it in two. * */ void dn_nsp_output(struct sock *sk) { struct dn_scp *scp = DN_SK(sk); struct sk_buff *skb; unsigned reduce_win = 0; /* * First we check for otherdata/linkservice messages */ if ((skb = skb_peek(&scp->other_xmit_queue)) != NULL) reduce_win = dn_nsp_clone_and_send(skb, GFP_ATOMIC); /* * If we may not send any data, we don't. * If we are still trying to get some other data down the * channel, we don't try and send any data. */ if (reduce_win || (scp->flowrem_sw != DN_SEND)) goto recalc_window; if ((skb = skb_peek(&scp->data_xmit_queue)) != NULL) reduce_win = dn_nsp_clone_and_send(skb, GFP_ATOMIC); /* * If we've sent any frame more than once, we cut the * send window size in half. There is always a minimum * window size of one available. */ recalc_window: if (reduce_win) { scp->snd_window >>= 1; if (scp->snd_window < NSP_MIN_WINDOW) scp->snd_window = NSP_MIN_WINDOW; } } int dn_nsp_xmit_timeout(struct sock *sk) { struct dn_scp *scp = DN_SK(sk); dn_nsp_output(sk); if (!skb_queue_empty(&scp->data_xmit_queue) || !skb_queue_empty(&scp->other_xmit_queue)) scp->persist = dn_nsp_persist(sk); return 0; } static inline __le16 *dn_mk_common_header(struct dn_scp *scp, struct sk_buff *skb, unsigned char msgflag, int len) { unsigned char *ptr = skb_push(skb, len); BUG_ON(len < 5); *ptr++ = msgflag; *((__le16 *)ptr) = scp->addrrem; ptr += 2; *((__le16 *)ptr) = scp->addrloc; ptr += 2; return (__le16 __force *)ptr; } static __le16 *dn_mk_ack_header(struct sock *sk, struct sk_buff *skb, unsigned char msgflag, int hlen, int other) { struct dn_scp *scp = DN_SK(sk); unsigned short acknum = scp->numdat_rcv & 0x0FFF; unsigned short ackcrs = scp->numoth_rcv & 0x0FFF; __le16 *ptr; BUG_ON(hlen < 9); scp->ackxmt_dat = acknum; scp->ackxmt_oth = ackcrs; acknum |= 0x8000; ackcrs |= 0x8000; /* If this is an "other data/ack" message, swap acknum and ackcrs */ if (other) { unsigned short tmp = acknum; acknum = ackcrs; ackcrs = tmp; } /* Set "cross subchannel" bit in ackcrs */ ackcrs |= 0x2000; ptr = (__le16 *)dn_mk_common_header(scp, skb, msgflag, hlen); *ptr++ = cpu_to_le16(acknum); *ptr++ = cpu_to_le16(ackcrs); return ptr; } static __le16 *dn_nsp_mk_data_header(struct sock *sk, struct sk_buff *skb, int oth) { struct dn_scp *scp = DN_SK(sk); struct dn_skb_cb *cb = DN_SKB_CB(skb); __le16 *ptr = dn_mk_ack_header(sk, skb, cb->nsp_flags, 11, oth); if (unlikely(oth)) { cb->segnum = scp->numoth; seq_add(&scp->numoth, 1); } else { cb->segnum = scp->numdat; seq_add(&scp->numdat, 1); } *(ptr++) = cpu_to_le16(cb->segnum); return ptr; } void dn_nsp_queue_xmit(struct sock *sk, struct sk_buff *skb, gfp_t gfp, int oth) { struct dn_scp *scp = DN_SK(sk); struct dn_skb_cb *cb = DN_SKB_CB(skb); unsigned long t = ((scp->nsp_srtt >> 2) + scp->nsp_rttvar) >> 1; cb->xmit_count = 0; dn_nsp_mk_data_header(sk, skb, oth); /* * Slow start: If we have been idle for more than * one RTT, then reset window to min size. */ if ((jiffies - scp->stamp) > t) scp->snd_window = NSP_MIN_WINDOW; if (oth) skb_queue_tail(&scp->other_xmit_queue, skb); else skb_queue_tail(&scp->data_xmit_queue, skb); if (scp->flowrem_sw != DN_SEND) return; dn_nsp_clone_and_send(skb, gfp); } int dn_nsp_check_xmit_queue(struct sock *sk, struct sk_buff *skb, struct sk_buff_head *q, unsigned short acknum) { struct dn_skb_cb *cb = DN_SKB_CB(skb); struct dn_scp *scp = DN_SK(sk); struct sk_buff *skb2, *n, *ack = NULL; int wakeup = 0; int try_retrans = 0; unsigned long reftime = cb->stamp; unsigned long pkttime; unsigned short xmit_count; unsigned short segnum; skb_queue_walk_safe(q, skb2, n) { struct dn_skb_cb *cb2 = DN_SKB_CB(skb2); if (dn_before_or_equal(cb2->segnum, acknum)) ack = skb2; /* printk(KERN_DEBUG "ack: %s %04x %04x\n", ack ? "ACK" : "SKIP", (int)cb2->segnum, (int)acknum); */ if (ack == NULL) continue; /* printk(KERN_DEBUG "check_xmit_queue: %04x, %d\n", acknum, cb2->xmit_count); */ /* Does _last_ packet acked have xmit_count > 1 */ try_retrans = 0; /* Remember to wake up the sending process */ wakeup = 1; /* Keep various statistics */ pkttime = cb2->stamp; xmit_count = cb2->xmit_count; segnum = cb2->segnum; /* Remove and drop ack'ed packet */ skb_unlink(ack, q); kfree_skb(ack); ack = NULL; /* * We don't expect to see acknowledgements for packets we * haven't sent yet. */ WARN_ON(xmit_count == 0); /* * If the packet has only been sent once, we can use it * to calculate the RTT and also open the window a little * further. */ if (xmit_count == 1) { if (dn_equal(segnum, acknum)) dn_nsp_rtt(sk, (long)(pkttime - reftime)); if (scp->snd_window < scp->max_window) scp->snd_window++; } /* * Packet has been sent more than once. If this is the last * packet to be acknowledged then we want to send the next * packet in the send queue again (assumes the remote host does * go-back-N error control). */ if (xmit_count > 1) try_retrans = 1; } if (try_retrans) dn_nsp_output(sk); return wakeup; } void dn_nsp_send_data_ack(struct sock *sk) { struct sk_buff *skb = NULL; if ((skb = dn_alloc_skb(sk, 9, GFP_ATOMIC)) == NULL) return; skb_reserve(skb, 9); dn_mk_ack_header(sk, skb, 0x04, 9, 0); dn_nsp_send(skb); } void dn_nsp_send_oth_ack(struct sock *sk) { struct sk_buff *skb = NULL; if ((skb = dn_alloc_skb(sk, 9, GFP_ATOMIC)) == NULL) return; skb_reserve(skb, 9); dn_mk_ack_header(sk, skb, 0x14, 9, 1); dn_nsp_send(skb); } void dn_send_conn_ack (struct sock *sk) { struct dn_scp *scp = DN_SK(sk); struct sk_buff *skb = NULL; struct nsp_conn_ack_msg *msg; if ((skb = dn_alloc_skb(sk, 3, sk->sk_allocation)) == NULL) return; msg = (struct nsp_conn_ack_msg *)skb_put(skb, 3); msg->msgflg = 0x24; msg->dstaddr = scp->addrrem; dn_nsp_send(skb); } void dn_nsp_delayed_ack(struct sock *sk) { struct dn_scp *scp = DN_SK(sk); if (scp->ackxmt_oth != scp->numoth_rcv) dn_nsp_send_oth_ack(sk); if (scp->ackxmt_dat != scp->numdat_rcv) dn_nsp_send_data_ack(sk); } static int dn_nsp_retrans_conn_conf(struct sock *sk) { struct dn_scp *scp = DN_SK(sk); if (scp->state == DN_CC) dn_send_conn_conf(sk, GFP_ATOMIC); return 0; } void dn_send_conn_conf(struct sock *sk, gfp_t gfp) { struct dn_scp *scp = DN_SK(sk); struct sk_buff *skb = NULL; struct nsp_conn_init_msg *msg; __u8 len = (__u8)le16_to_cpu(scp->conndata_out.opt_optl); if ((skb = dn_alloc_skb(sk, 50 + len, gfp)) == NULL) return; msg = (struct nsp_conn_init_msg *)skb_put(skb, sizeof(*msg)); msg->msgflg = 0x28; msg->dstaddr = scp->addrrem; msg->srcaddr = scp->addrloc; msg->services = scp->services_loc; msg->info = scp->info_loc; msg->segsize = cpu_to_le16(scp->segsize_loc); *skb_put(skb,1) = len; if (len > 0) memcpy(skb_put(skb, len), scp->conndata_out.opt_data, len); dn_nsp_send(skb); scp->persist = dn_nsp_persist(sk); scp->persist_fxn = dn_nsp_retrans_conn_conf; } static __inline__ void dn_nsp_do_disc(struct sock *sk, unsigned char msgflg, unsigned short reason, gfp_t gfp, struct dst_entry *dst, int ddl, unsigned char *dd, __le16 rem, __le16 loc) { struct sk_buff *skb = NULL; int size = 7 + ddl + ((msgflg == NSP_DISCINIT) ? 1 : 0); unsigned char *msg; if ((dst == NULL) || (rem == 0)) { if (net_ratelimit()) printk(KERN_DEBUG "DECnet: dn_nsp_do_disc: BUG! Please report this to SteveW@ACM.org rem=%u dst=%p\n", le16_to_cpu(rem), dst); return; } if ((skb = dn_alloc_skb(sk, size, gfp)) == NULL) return; msg = skb_put(skb, size); *msg++ = msgflg; *(__le16 *)msg = rem; msg += 2; *(__le16 *)msg = loc; msg += 2; *(__le16 *)msg = cpu_to_le16(reason); msg += 2; if (msgflg == NSP_DISCINIT) *msg++ = ddl; if (ddl) { memcpy(msg, dd, ddl); } /* * This doesn't go via the dn_nsp_send() function since we need * to be able to send disc packets out which have no socket * associations. */ skb_dst_set(skb, dst_clone(dst)); dst_output(skb); } void dn_nsp_send_disc(struct sock *sk, unsigned char msgflg, unsigned short reason, gfp_t gfp) { struct dn_scp *scp = DN_SK(sk); int ddl = 0; if (msgflg == NSP_DISCINIT) ddl = le16_to_cpu(scp->discdata_out.opt_optl); if (reason == 0) reason = le16_to_cpu(scp->discdata_out.opt_status); dn_nsp_do_disc(sk, msgflg, reason, gfp, sk->sk_dst_cache, ddl, scp->discdata_out.opt_data, scp->addrrem, scp->addrloc); } void dn_nsp_return_disc(struct sk_buff *skb, unsigned char msgflg, unsigned short reason) { struct dn_skb_cb *cb = DN_SKB_CB(skb); int ddl = 0; gfp_t gfp = GFP_ATOMIC; dn_nsp_do_disc(NULL, msgflg, reason, gfp, skb_dst(skb), ddl, NULL, cb->src_port, cb->dst_port); } void dn_nsp_send_link(struct sock *sk, unsigned char lsflags, char fcval) { struct dn_scp *scp = DN_SK(sk); struct sk_buff *skb; unsigned char *ptr; gfp_t gfp = GFP_ATOMIC; if ((skb = dn_alloc_skb(sk, DN_MAX_NSP_DATA_HEADER + 2, gfp)) == NULL) return; skb_reserve(skb, DN_MAX_NSP_DATA_HEADER); ptr = skb_put(skb, 2); DN_SKB_CB(skb)->nsp_flags = 0x10; *ptr++ = lsflags; *ptr = fcval; dn_nsp_queue_xmit(sk, skb, gfp, 1); scp->persist = dn_nsp_persist(sk); scp->persist_fxn = dn_nsp_xmit_timeout; } static int dn_nsp_retrans_conninit(struct sock *sk) { struct dn_scp *scp = DN_SK(sk); if (scp->state == DN_CI) dn_nsp_send_conninit(sk, NSP_RCI); return 0; } void dn_nsp_send_conninit(struct sock *sk, unsigned char msgflg) { struct dn_scp *scp = DN_SK(sk); struct nsp_conn_init_msg *msg; unsigned char aux; unsigned char menuver; struct dn_skb_cb *cb; unsigned char type = 1; gfp_t allocation = (msgflg == NSP_CI) ? sk->sk_allocation : GFP_ATOMIC; struct sk_buff *skb = dn_alloc_skb(sk, 200, allocation); if (!skb) return; cb = DN_SKB_CB(skb); msg = (struct nsp_conn_init_msg *)skb_put(skb,sizeof(*msg)); msg->msgflg = msgflg; msg->dstaddr = 0x0000; /* Remote Node will assign it*/ msg->srcaddr = scp->addrloc; msg->services = scp->services_loc; /* Requested flow control */ msg->info = scp->info_loc; /* Version Number */ msg->segsize = cpu_to_le16(scp->segsize_loc); /* Max segment size */ if (scp->peer.sdn_objnum) type = 0; skb_put(skb, dn_sockaddr2username(&scp->peer, skb_tail_pointer(skb), type)); skb_put(skb, dn_sockaddr2username(&scp->addr, skb_tail_pointer(skb), 2)); menuver = DN_MENUVER_ACC | DN_MENUVER_USR; if (scp->peer.sdn_flags & SDF_PROXY) menuver |= DN_MENUVER_PRX; if (scp->peer.sdn_flags & SDF_UICPROXY) menuver |= DN_MENUVER_UIC; *skb_put(skb, 1) = menuver; /* Menu Version */ aux = scp->accessdata.acc_userl; *skb_put(skb, 1) = aux; if (aux > 0) memcpy(skb_put(skb, aux), scp->accessdata.acc_user, aux); aux = scp->accessdata.acc_passl; *skb_put(skb, 1) = aux; if (aux > 0) memcpy(skb_put(skb, aux), scp->accessdata.acc_pass, aux); aux = scp->accessdata.acc_accl; *skb_put(skb, 1) = aux; if (aux > 0) memcpy(skb_put(skb, aux), scp->accessdata.acc_acc, aux); aux = (__u8)le16_to_cpu(scp->conndata_out.opt_optl); *skb_put(skb, 1) = aux; if (aux > 0) memcpy(skb_put(skb, aux), scp->conndata_out.opt_data, aux); scp->persist = dn_nsp_persist(sk); scp->persist_fxn = dn_nsp_retrans_conninit; cb->rt_flags = DN_RT_F_RQR; dn_nsp_send(skb); }