diff options
Diffstat (limited to 'net/decnet/dn_nsp_out.c')
| -rw-r--r-- | net/decnet/dn_nsp_out.c | 703 |
1 files changed, 703 insertions, 0 deletions
diff --git a/net/decnet/dn_nsp_out.c b/net/decnet/dn_nsp_out.c new file mode 100644 index 000000000..a1779de6b --- /dev/null +++ b/net/decnet/dn_nsp_out.c @@ -0,0 +1,703 @@ +/* + * 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 <emserrat@geocities.com> + * + * 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 <linux/errno.h> +#include <linux/types.h> +#include <linux/socket.h> +#include <linux/in.h> +#include <linux/kernel.h> +#include <linux/timer.h> +#include <linux/string.h> +#include <linux/sockios.h> +#include <linux/net.h> +#include <linux/netdevice.h> +#include <linux/inet.h> +#include <linux/route.h> +#include <linux/slab.h> +#include <net/sock.h> +#include <linux/fcntl.h> +#include <linux/mm.h> +#include <linux/termios.h> +#include <linux/interrupt.h> +#include <linux/proc_fs.h> +#include <linux/stat.h> +#include <linux/init.h> +#include <linux/poll.h> +#include <linux/if_packet.h> +#include <net/neighbour.h> +#include <net/dst.h> +#include <net/flow.h> +#include <net/dn.h> +#include <net/dn_nsp.h> +#include <net/dn_dev.h> +#include <net/dn_route.h> + + +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(&init_net, skb->sk, 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 int 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 int 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) + swap(acknum, ackcrs); + + /* Set "cross subchannel" bit in ackcrs */ + ackcrs |= 0x2000; + + ptr = 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 = skb_put(skb, 3); + msg->msgflg = 0x24; + msg->dstaddr = scp->addrrem; + + dn_nsp_send(skb); +} + +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 = 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_u8(skb, len); + + if (len > 0) + skb_put_data(skb, 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)) { + net_dbg_ratelimited("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(&init_net, skb->sk, 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_dst_get(sk), 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 = 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_u8(skb, menuver); /* Menu Version */ + + aux = scp->accessdata.acc_userl; + skb_put_u8(skb, aux); + if (aux > 0) + skb_put_data(skb, scp->accessdata.acc_user, aux); + + aux = scp->accessdata.acc_passl; + skb_put_u8(skb, aux); + if (aux > 0) + skb_put_data(skb, scp->accessdata.acc_pass, aux); + + aux = scp->accessdata.acc_accl; + skb_put_u8(skb, aux); + if (aux > 0) + skb_put_data(skb, scp->accessdata.acc_acc, aux); + + aux = (__u8)le16_to_cpu(scp->conndata_out.opt_optl); + skb_put_u8(skb, aux); + if (aux > 0) + skb_put_data(skb, 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); +} |