diff options
author | Ralf Baechle <ralf@linux-mips.org> | 1999-06-17 14:08:29 +0000 |
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committer | Ralf Baechle <ralf@linux-mips.org> | 1999-06-17 14:08:29 +0000 |
commit | 57d569635c05dc4ea9b9f1f8dcec69b9ddc989b2 (patch) | |
tree | 1f703abf7d95dcd50ee52da3b96eb1b4b2b4ea53 /net/decnet/dn_nsp_in.c | |
parent | 59223edaa18759982db0a8aced0e77457d10c68e (diff) |
The rest of 2.3.6.
Diffstat (limited to 'net/decnet/dn_nsp_in.c')
-rw-r--r-- | net/decnet/dn_nsp_in.c | 703 |
1 files changed, 703 insertions, 0 deletions
diff --git a/net/decnet/dn_nsp_in.c b/net/decnet/dn_nsp_in.c new file mode 100644 index 000000000..6d10df045 --- /dev/null +++ b/net/decnet/dn_nsp_in.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 (Input) + * + * 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: Add changes from Eduardo Serrat's patches. + * Steve Whitehouse: Put all ack handling code in a common routine. + * Steve Whitehouse: Put other common bits into dn_nsp_rx() + * Steve Whitehouse: More checks on skb->len to catch bogus packets + * Fixed various race conditions and possible nasties. + * Steve Whitehouse: Now handles returned conninit frames. + */ + +/****************************************************************************** + (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/config.h> +#include <linux/errno.h> +#include <linux/types.h> +#include <linux/socket.h> +#include <linux/in.h> +#include <linux/kernel.h> +#include <linux/sched.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 <net/sock.h> +#include <asm/segment.h> +#include <asm/system.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 <net/neighbour.h> +#include <net/dst.h> +#include <net/dn_nsp.h> +#include <net/dn_dev.h> +#include <net/dn_route.h> +#include <net/dn_raw.h> + + +/* + * For this function we've flipped the cross-subchannel bit + * if the message is an otherdata or linkservice message. Thus + * we can use it to work out what to update. + */ +static void dn_ack(struct sock *sk, struct sk_buff *skb, unsigned short ack) +{ + struct dn_scp *scp = &sk->protinfo.dn; + unsigned short type = ((ack >> 12) & 0x0003); + int wakeup = 0; + + /* printk(KERN_DEBUG "dn_ack: %hd 0x%04hx\n", type, ack); */ + + switch(type) { + case 0: /* ACK - Data */ + if (after(ack, scp->ackrcv_dat)) { + scp->ackrcv_dat = ack & 0x0fff; + wakeup |= dn_nsp_check_xmit_queue(sk, skb, &scp->data_xmit_queue, ack); + } + break; + case 1: /* NAK - Data */ + break; + case 2: /* ACK - OtherData */ + if (after(ack, scp->ackrcv_oth)) { + scp->ackrcv_oth = ack & 0x0fff; + wakeup |= dn_nsp_check_xmit_queue(sk, skb, &scp->other_xmit_queue, ack); + } + break; + case 3: /* NAK - OtherData */ + break; + } + + if (wakeup && !sk->dead) + sk->state_change(sk); +} + +/* + * This function is a universal ack processor. + */ +static int dn_process_ack(struct sock *sk, struct sk_buff *skb, int oth) +{ + unsigned short *ptr = (unsigned short *)skb->data; + int len = 0; + unsigned short ack; + + if (skb->len < 2) + return len; + + if ((ack = dn_ntohs(*ptr)) & 0x8000) { + skb_pull(skb, 2); + ptr++; + len += 2; + if ((ack & 0x4000) == 0) { + if (oth) + ack ^= 0x2000; + dn_ack(sk, skb, ack); + } + } + + if (skb->len < 2) + return len; + + if ((ack = dn_ntohs(*ptr)) & 0x8000) { + skb_pull(skb, 2); + len += 2; + if ((ack & 0x4000) == 0) { + if (oth) + ack ^= 0x2000; + dn_ack(sk, skb, ack); + } + } + + return len; +} + + +/* + * This function uses a slightly different lookup method + * to find its sockets, since it searches on object name/number + * rather than port numbers + */ +static int dn_conninit_rx(struct sk_buff *skb) +{ + struct sock *sk; + struct dn_skb_cb *cb = (struct dn_skb_cb *)skb->cb; + struct nsp_conn_init_msg *msg = (struct nsp_conn_init_msg *)skb->data; + struct sockaddr_dn addr; + unsigned char type = 0; + + memset(&addr, 0, sizeof(struct sockaddr_dn)); + + cb->src_port = msg->srcaddr; + cb->dst_port = msg->dstaddr; + cb->services = msg->services; + cb->info = msg->info; + cb->segsize = dn_ntohs(msg->segsize); + + skb_pull(skb, sizeof(*msg)); + + /* printk(KERN_DEBUG "username2sockaddr 1\n"); */ + if (dn_username2sockaddr(skb->data, skb->len, &addr, &type) < 0) + goto free_out; + + if (type > 1) + goto free_out; + + /* printk(KERN_DEBUG "looking for listener...\n"); */ + if ((sk = dn_sklist_find_listener(&addr)) == NULL) + return 1; + + /* printk(KERN_DEBUG "checking backlog...\n"); */ + if (sk->ack_backlog >= sk->max_ack_backlog) + goto free_out; + + /* printk(KERN_DEBUG "waking up socket...\n"); */ + sk->ack_backlog++; + skb_queue_tail(&sk->receive_queue, skb); + sk->state_change(sk); + + return 0; + +free_out: + kfree_skb(skb); + return 0; +} + +static void dn_nsp_conn_conf(struct sock *sk, struct sk_buff *skb) +{ + struct dn_skb_cb *cb = (struct dn_skb_cb *)skb->cb; + struct dn_scp *scp = &sk->protinfo.dn; + + if (skb->len < 3) + goto out; + + cb->services = *skb->data; + cb->info = *(skb->data+1); + skb_pull(skb, 2); + cb->segsize = dn_ntohs(*(__u16 *)skb->data); + skb_pull(skb, 2); + + /* + * FIXME: Check out services and info fields to check that + * we can talk to this kind of node. + */ + + if ((scp->state == DN_CI) || (scp->state == DN_CD)) { + scp->persist = 0; + scp->addrrem = cb->src_port; + sk->state = TCP_ESTABLISHED; + scp->state = DN_RUN; + + if (scp->mss > cb->segsize) + scp->mss = cb->segsize; + if (scp->mss < 230) + scp->mss = 230; + + if (skb->len > 0) { + unsigned char dlen = *skb->data; + if ((dlen <= 16) && (dlen <= skb->len)) { + scp->conndata_in.opt_optl = dlen; + memcpy(scp->conndata_in.opt_data, skb->data + 1, dlen); + } + } + dn_nsp_send_lnk(sk, DN_NOCHANGE); + if (!sk->dead) + sk->state_change(sk); + } + +out: + kfree_skb(skb); +} + +static void dn_nsp_conn_ack(struct sock *sk, struct sk_buff *skb) +{ + struct dn_scp *scp = &sk->protinfo.dn; + + if (scp->state == DN_CI) { + scp->state = DN_CD; + scp->persist = 0; + } + + kfree_skb(skb); +} + +static void dn_nsp_disc_init(struct sock *sk, struct sk_buff *skb) +{ + struct dn_scp *scp = &sk->protinfo.dn; + struct dn_skb_cb *cb = (struct dn_skb_cb *)skb->cb; + unsigned short reason; + + /* printk(KERN_DEBUG "DECnet: discinit %d\n", skb->len); */ + + if (skb->len < 2) + goto out; + + reason = dn_ntohs(*(__u16 *)skb->data); + skb_pull(skb, 2); + + scp->discdata_in.opt_status = reason; + scp->discdata_in.opt_optl = 0; + memset(scp->discdata_in.opt_data, 0, 16); + + if (skb->len > 0) { + unsigned char dlen = *skb->data; + if ((dlen <= 16) && (dlen <= skb->len)) { + scp->discdata_in.opt_optl = dlen; + memcpy(scp->discdata_in.opt_data, skb->data + 1, dlen); + } + } + + scp->addrrem = cb->src_port; + sk->state = TCP_CLOSE; + + /* printk(KERN_DEBUG "DECnet: discinit\n"); */ + + switch(scp->state) { + case DN_CI: + case DN_CD: + scp->state = DN_RJ; + break; + case DN_RUN: + sk->shutdown |= SHUTDOWN_MASK; + scp->state = DN_DN; + break; + case DN_DI: + scp->state = DN_DIC; + break; + } + + if (!sk->dead) + sk->state_change(sk); + + dn_destroy_sock(sk); + +out: + kfree_skb(skb); +} + +/* + * disc_conf messages are also called no_resources or no_link + * messages depending upon the "reason" field. + */ +static void dn_nsp_disc_conf(struct sock *sk, struct sk_buff *skb) +{ + struct dn_scp *scp = &sk->protinfo.dn; + unsigned short reason; + + if (skb->len != 2) + goto out; + + reason = dn_ntohs(*(__u16 *)skb->data); + + sk->state = TCP_CLOSE; + + switch(scp->state) { + case DN_CI: + scp->state = DN_NR; + break; + case DN_DR: + if (reason == NSP_REASON_DC) + scp->state = DN_DRC; + if (reason == NSP_REASON_NL) + scp->state = DN_CN; + break; + case DN_DI: + scp->state = DN_DIC; + break; + case DN_RUN: + sk->shutdown |= SHUTDOWN_MASK; + case DN_CC: + scp->state = DN_CN; + } + + if (!sk->dead) + sk->state_change(sk); + + dn_destroy_sock(sk); + +out: + kfree_skb(skb); +} + +static void dn_nsp_linkservice(struct sock *sk, struct sk_buff *skb) +{ + struct dn_skb_cb *cb = (struct dn_skb_cb *)skb->cb; + unsigned short segnum; + unsigned char lsflags; + char fcval; + + if (skb->len != 4) + goto out; + + cb->segnum = segnum = dn_ntohs(*(__u16 *)skb->data); + skb_pull(skb, 2); + lsflags = *(unsigned char *)skb->data; + skb_pull(skb, 1); + fcval = *(char *)skb->data; + + if (lsflags & 0xf0) + goto out; + + if (((sk->protinfo.dn.numoth_rcv + 1) & 0x0FFF) == (segnum & 0x0FFF)) { + sk->protinfo.dn.numoth_rcv += 1; + switch(lsflags & 0x03) { + case 0x00: + break; + case 0x01: + sk->protinfo.dn.flowrem_sw = DN_DONTSEND; + break; + case 0x02: + sk->protinfo.dn.flowrem_sw = DN_SEND; + dn_nsp_output(sk); + if (!sk->dead) + sk->state_change(sk); + } + + } + + dn_nsp_send_oth_ack(sk); + +out: + kfree_skb(skb); +} + +/* + * Copy of sock_queue_rcv_skb (from net/core/datagram.c) to + * queue other data segments. Also we send SIGURG here instead + * of the normal SIGIO, 'cos its out of band data. + */ +static __inline__ int dn_queue_other_skb(struct sock *sk, struct sk_buff *skb) +{ + struct dn_scp *scp = &sk->protinfo.dn; + + /* Cast skb->rcvbuf to unsigned... It's pointless, but reduces + number of warnings when compiling with -W --ANK + */ + if (atomic_read(&sk->rmem_alloc) + skb->truesize >= (unsigned)sk->rcvbuf +) + return -ENOMEM; + +#ifdef CONFIG_FILTER + if (sk->filter) + { + if (sk_filter(skb, sk->filter)) + return -EPERM; /* Toss packet */ + } +#endif /* CONFIG_FILTER */ + + skb_set_owner_r(skb, sk); + skb_queue_tail(&scp->other_receive_queue, skb); + + if (!sk->dead) { + struct socket *sock = sk->socket; + wake_up_interruptible(sk->sleep); + if (!(sock->flags & SO_WAITDATA) && sock->fasync_list) + kill_fasync(sock->fasync_list, SIGURG); + } + + return 0; +} + +static void dn_nsp_otherdata(struct sock *sk, struct sk_buff *skb) +{ + struct dn_scp *scp = &sk->protinfo.dn; + unsigned short segnum; + struct dn_skb_cb *cb = (struct dn_skb_cb *)skb->cb; + int queued = 0; + + if (skb->len < 2) + goto out; + + cb->segnum = segnum = dn_ntohs(*(__u16 *)skb->data); + skb_pull(skb, 2); + + if (((sk->protinfo.dn.numoth_rcv + 1) & 0x0fff) == (segnum & 0x0fff)) { + + if (dn_queue_other_skb(sk, skb) == 0) { + sk->protinfo.dn.numoth_rcv++; + scp->other_report = 0; + queued = 1; + } + } + + dn_nsp_send_oth_ack(sk); +out: + if (!queued) + kfree_skb(skb); +} + +static void dn_nsp_data(struct sock *sk, struct sk_buff *skb) +{ + int queued = 0; + unsigned short segnum; + struct dn_skb_cb *cb = (struct dn_skb_cb *)skb->cb; + struct dn_scp *scp = &sk->protinfo.dn; + + if (skb->len < 2) + goto out; + + cb->segnum = segnum = dn_ntohs(*(__u16 *)skb->data); + skb_pull(skb, 2); + + if (((sk->protinfo.dn.numdat_rcv + 1) & 0x0FFF) == + (segnum & 0x0FFF)) { + + if (sock_queue_rcv_skb(sk, skb) == 0) { + sk->protinfo.dn.numdat_rcv++; + queued = 1; + } + + if ((scp->flowloc_sw == DN_SEND) && dn_congested(sk)) { + scp->flowloc_sw = DN_DONTSEND; + dn_nsp_send_lnk(sk, DN_DONTSEND); + } + } + + dn_nsp_send_data_ack(sk); +out: + if (!queued) + kfree_skb(skb); +} + +/* + * If one of our conninit messages is returned, this function + * deals with it. It puts the socket into the NO_COMMUNICATION + * state. + */ +static void dn_returned_conninit(struct sk_buff *skb) +{ + struct dn_skb_cb *cb = (struct dn_skb_cb *)skb->cb; + struct sock *sk; + + cb->dst_port = cb->src_port; + cb->src_port = 0; + + if ((sk = dn_find_by_skb(skb)) != NULL) { + struct dn_scp *scp = &sk->protinfo.dn; + if (scp->state == DN_CI) { + scp->state = DN_NC; + sk->state = TCP_CLOSE; + if (!sk->dead) + sk->state_change(sk); + } + } + + kfree_skb(skb); +} + +int dn_nsp_rx(struct sk_buff *skb) +{ + struct dn_skb_cb *cb = (struct dn_skb_cb *)skb->cb; + struct sock *sk = NULL; + unsigned char *ptr = (unsigned char *)skb->data; + + skb->h.raw = skb->data; + cb->nsp_flags = *ptr++; + + if (decnet_debug_level & 1) + printk(KERN_DEBUG "dn_nsp_rx: Message type 0x%02x\n", (int)cb->nsp_flags); + +#ifdef CONFIG_DECNET_RAW + dn_raw_rx_nsp(skb); +#endif /* CONFIG_DECNET_RAW */ + + if (skb->len < 2) + goto free_out; + + if (cb->nsp_flags & 0x83) + goto free_out; + + /* + * Returned packets... + */ + if (cb->rt_flags & DN_RT_F_RTS) { + if ((cb->nsp_flags & 0x0c) == 0x08) { + switch(cb->nsp_flags & 0x70) { + case 0x10: + case 0x60: + dn_returned_conninit(skb); + goto out; + } + } + goto free_out; + } + + /* + * Filter out conninits and useless packet types + */ + if ((cb->nsp_flags & 0x0c) == 0x08) { + switch(cb->nsp_flags & 0x70) { + case 0x00: /* NOP */ + case 0x70: /* Reserved */ + case 0x50: /* Reserved, Phase II node init */ + goto free_out; + case 0x10: + case 0x60: + return dn_conninit_rx(skb); + } + } + + if (skb->len < 3) + goto free_out; + + /* + * Grab the destination address. + */ + cb->dst_port = *(unsigned short *)ptr; + cb->src_port = 0; + ptr += 2; + + /* + * If not a connack, grab the source address too. + */ + if (skb->len >= 5) { + cb->src_port = *(unsigned short *)ptr; + ptr += 2; + skb_pull(skb, 5); + } + + /* + * Find the socket to which this skb is destined. + */ + if ((sk = dn_find_by_skb(skb)) != NULL) { + struct dn_scp *scp = &sk->protinfo.dn; + int ret; + /* printk(KERN_DEBUG "dn_nsp_rx: Found a socket\n"); */ + + /* Reset backoff */ + scp->nsp_rxtshift = 0; + + bh_lock_sock(sk); + ret = 0; + if (sk->lock.users == 0) + ret = dn_nsp_backlog_rcv(sk, skb); + else + sk_add_backlog(sk, skb); + bh_unlock_sock(sk); + + return ret; + } + return 1; + +free_out: + kfree_skb(skb); +out: + return 0; +} + +/* + * This is the main receive routine for sockets. It is called + * from the above when the socket is not busy, and also from + * sock_release() when there is a backlog queued up. + */ +int dn_nsp_backlog_rcv(struct sock *sk, struct sk_buff *skb) +{ + struct dn_scp *scp = &sk->protinfo.dn; + struct dn_skb_cb *cb = (struct dn_skb_cb *)skb->cb; + + /* + * Control packet. + */ + if ((cb->nsp_flags & 0x0c) == 0x08) { + /* printk(KERN_DEBUG "control type\n"); */ + switch(cb->nsp_flags & 0x70) { + case 0x20: + dn_nsp_conn_conf(sk, skb); + break; + case 0x30: + dn_nsp_disc_init(sk, skb); + break; + case 0x40: + dn_nsp_disc_conf(sk, skb); + break; + } + + } else if (cb->nsp_flags == 0x24) { + /* + * Special for connacks, 'cos they don't have + * ack data or ack otherdata info. + */ + dn_nsp_conn_ack(sk, skb); + } else { + int other = 1; + + if ((cb->nsp_flags & 0x1c) == 0) + other = 0; + if (cb->nsp_flags == 0x04) + other = 0; + + /* + * Read out ack data here, this applies equally + * to data, other data, link serivce and both + * ack data and ack otherdata. + */ + dn_process_ack(sk, skb, other); + + /* + * If we've some sort of data here then call a + * suitable routine for dealing with it, otherwise + * the packet is an ack and can be discarded. All + * data frames can also kick a CC socket into RUN. + */ + if ((cb->nsp_flags & 0x0c) == 0) { + + if ((scp->state == DN_CC) && !sk->dead) { + scp->state = DN_RUN; + sk->state = TCP_ESTABLISHED; + sk->state_change(sk); + } + + if (scp->state != DN_RUN) + goto free_out; + + switch(cb->nsp_flags) { + case 0x10: /* LS */ + dn_nsp_linkservice(sk, skb); + break; + case 0x30: /* OD */ + dn_nsp_otherdata(sk, skb); + break; + default: + dn_nsp_data(sk, skb); + } + + } else { /* Ack, chuck it out here */ +free_out: + kfree_skb(skb); + } + } + + return 0; +} + |