Linux-2.6.12-rc2v2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 934 insertions, 0 deletions

diff --git a/net/decnet/dn_nsp_in.c b/net/decnet/dn_nsp_in.c
new file mode 100644
index 000000000000..202dbde9850d
--- /dev/null
+++ b/net/decnet/dn_nsp_in.c
@@ -0,0 +1,934 @@
+/*
+ * 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.
+ *     David S. Miller:  New socket locking
+ *    Steve Whitehouse:  Fixed lockup when socket filtering was enabled.
+ *         Paul Koning:  Fix to push CC sockets into RUN when acks are
+ *                       received.
+ *    Steve Whitehouse:
+ *   Patrick Caulfield:  Checking conninits for correctness & sending of error
+ *                       responses.
+ *    Steve Whitehouse:  Added backlog congestion level return codes.
+ *   Patrick Caulfield:
+ *    Steve Whitehouse:  Added flow control support (outbound)
+ *    Steve Whitehouse:  Prepare for nonlinear skbs
+ */
+
+/******************************************************************************
+    (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 <net/tcp.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 <linux/netfilter_decnet.h>
+#include <net/neighbour.h>
+#include <net/dst.h>
+#include <net/dn.h>
+#include <net/dn_nsp.h>
+#include <net/dn_dev.h>
+#include <net/dn_route.h>
+
+extern int decnet_log_martians;
+
+static void dn_log_martian(struct sk_buff *skb, const char *msg)
+{
+        if (decnet_log_martians && net_ratelimit()) {
+                char *devname = skb->dev ? skb->dev->name : "???";
+                struct dn_skb_cb *cb = DN_SKB_CB(skb);
+                printk(KERN_INFO "DECnet: Martian packet (%s) dev=%s src=0x%04hx dst=0x%04hx srcport=0x%04hx dstport=0x%04hx\n", msg, devname, cb->src, cb->dst, cb->src_port, cb->dst_port);
+        }
+}
+
+/*
+ * 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 = DN_SK(sk);
+        unsigned short type = ((ack >> 12) & 0x0003);
+        int wakeup = 0;
+
+        switch(type) {
+                case 0: /* ACK - Data */
+                        if (dn_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 (dn_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 && !sock_flag(sk, SOCK_DEAD))
+                sk->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;
+}
+
+
+/**
+ * dn_check_idf - Check an image data field format is correct.
+ * @pptr: Pointer to pointer to image data
+ * @len: Pointer to length of image data
+ * @max: The maximum allowed length of the data in the image data field
+ * @follow_on: Check that this many bytes exist beyond the end of the image data
+ *
+ * Returns: 0 if ok, -1 on error
+ */
+static inline int dn_check_idf(unsigned char **pptr, int *len, unsigned char max, unsigned char follow_on)
+{
+        unsigned char *ptr = *pptr;
+        unsigned char flen = *ptr++;
+
+        (*len)--;
+        if (flen > max)
+                return -1;
+        if ((flen + follow_on) > *len)
+                return -1;
+
+        *len -= flen;
+        *pptr = ptr + flen;
+        return 0;
+}
+
+/*
+ * Table of reason codes to pass back to node which sent us a badly
+ * formed message, plus text messages for the log. A zero entry in
+ * the reason field means "don't reply" otherwise a disc init is sent with
+ * the specified reason code.
+ */
+static struct {
+        unsigned short reason;
+        const char *text;
+} ci_err_table[] = {
+ { 0,             "CI: Truncated message" },
+ { NSP_REASON_ID, "CI: Destination username error" },
+ { NSP_REASON_ID, "CI: Destination username type" },
+ { NSP_REASON_US, "CI: Source username error" },
+ { 0,             "CI: Truncated at menuver" },
+ { 0,             "CI: Truncated before access or user data" },
+ { NSP_REASON_IO, "CI: Access data format error" },
+ { NSP_REASON_IO, "CI: User data format error" }
+};
+
+/*
+ * This function uses a slightly different lookup method
+ * to find its sockets, since it searches on object name/number
+ * rather than port numbers. Various tests are done to ensure that
+ * the incoming data is in the correct format before it is queued to
+ * a socket.
+ */
+static struct sock *dn_find_listener(struct sk_buff *skb, unsigned short *reason)
+{
+        struct dn_skb_cb *cb = DN_SKB_CB(skb);
+        struct nsp_conn_init_msg *msg = (struct nsp_conn_init_msg *)skb->data;
+        struct sockaddr_dn dstaddr;
+        struct sockaddr_dn srcaddr;
+        unsigned char type = 0;
+        int dstlen;
+        int srclen;
+        unsigned char *ptr;
+        int len;
+        int err = 0;
+        unsigned char menuver;
+
+        memset(&dstaddr, 0, sizeof(struct sockaddr_dn));
+        memset(&srcaddr, 0, sizeof(struct sockaddr_dn));
+
+        /*
+         * 1. Decode & remove message header
+         */
+        cb->src_port = msg->srcaddr;
+        cb->dst_port = msg->dstaddr;
+        cb->services = msg->services;
+        cb->info     = msg->info;
+        cb->segsize  = dn_ntohs(msg->segsize);
+
+        if (!pskb_may_pull(skb, sizeof(*msg)))
+                goto err_out;
+
+        skb_pull(skb, sizeof(*msg));
+
+        len = skb->len;
+        ptr = skb->data;
+
+        /*
+         * 2. Check destination end username format
+         */
+        dstlen = dn_username2sockaddr(ptr, len, &dstaddr, &type);
+        err++;
+        if (dstlen < 0)
+                goto err_out;
+
+        err++;
+        if (type > 1)
+                goto err_out;
+
+        len -= dstlen;
+        ptr += dstlen;
+
+        /*
+         * 3. Check source end username format
+         */
+        srclen = dn_username2sockaddr(ptr, len, &srcaddr, &type);
+        err++;
+        if (srclen < 0)
+                goto err_out;
+
+        len -= srclen;
+        ptr += srclen;
+        err++;
+        if (len < 1)
+                goto err_out;
+
+        menuver = *ptr;
+        ptr++;
+        len--;
+
+        /*
+         * 4. Check that optional data actually exists if menuver says it does
+         */
+        err++;
+        if ((menuver & (DN_MENUVER_ACC | DN_MENUVER_USR)) && (len < 1))
+                goto err_out;
+
+        /*
+         * 5. Check optional access data format
+         */
+        err++;
+        if (menuver & DN_MENUVER_ACC) {
+                if (dn_check_idf(&ptr, &len, 39, 1))
+                        goto err_out;
+                if (dn_check_idf(&ptr, &len, 39, 1))
+                        goto err_out;
+                if (dn_check_idf(&ptr, &len, 39, (menuver & DN_MENUVER_USR) ? 1 : 0))
+                        goto err_out;
+        }
+
+        /*
+         * 6. Check optional user data format
+         */
+        err++;
+        if (menuver & DN_MENUVER_USR) {
+                if (dn_check_idf(&ptr, &len, 16, 0))
+                        goto err_out;
+        }
+
+        /*
+         * 7. Look up socket based on destination end username
+         */
+        return dn_sklist_find_listener(&dstaddr);
+err_out:
+        dn_log_martian(skb, ci_err_table[err].text);
+        *reason = ci_err_table[err].reason;
+        return NULL;
+}
+
+
+static void dn_nsp_conn_init(struct sock *sk, struct sk_buff *skb)
+{
+        if (sk_acceptq_is_full(sk)) {
+                kfree_skb(skb);
+                return;
+        }
+
+        sk->sk_ack_backlog++;
+        skb_queue_tail(&sk->sk_receive_queue, skb);
+        sk->sk_state_change(sk);
+}
+
+static void dn_nsp_conn_conf(struct sock *sk, struct sk_buff *skb)
+{
+        struct dn_skb_cb *cb = DN_SKB_CB(skb);
+        struct dn_scp *scp = DN_SK(sk);
+        unsigned char *ptr;
+
+        if (skb->len < 4)
+                goto out;
+
+        ptr = skb->data;
+        cb->services = *ptr++;
+        cb->info = *ptr++;
+        cb->segsize = dn_ntohs(*(__u16 *)ptr);
+
+        if ((scp->state == DN_CI) || (scp->state == DN_CD)) {
+                scp->persist = 0;
+                scp->addrrem = cb->src_port;
+                sk->sk_state = TCP_ESTABLISHED;
+                scp->state = DN_RUN;
+                scp->services_rem = cb->services;
+                scp->info_rem = cb->info;
+                scp->segsize_rem = cb->segsize;
+
+                if ((scp->services_rem & NSP_FC_MASK) == NSP_FC_NONE)
+                        scp->max_window = decnet_no_fc_max_cwnd;
+
+                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_link(sk, DN_NOCHANGE, 0);
+                if (!sock_flag(sk, SOCK_DEAD))
+                        sk->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 = DN_SK(sk);
+
+        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 = DN_SK(sk);
+        struct dn_skb_cb *cb = DN_SKB_CB(skb);
+        unsigned short reason;
+
+        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->sk_state = TCP_CLOSE;
+
+        switch(scp->state) {
+                case DN_CI:
+                case DN_CD:
+                        scp->state = DN_RJ;
+                        sk->sk_err = ECONNREFUSED;
+                        break;
+                case DN_RUN:
+                        sk->sk_shutdown |= SHUTDOWN_MASK;
+                        scp->state = DN_DN;
+                        break;
+                case DN_DI:
+                        scp->state = DN_DIC;
+                        break;
+        }
+
+        if (!sock_flag(sk, SOCK_DEAD)) {
+                if (sk->sk_socket->state != SS_UNCONNECTED)
+                        sk->sk_socket->state = SS_DISCONNECTING;
+                sk->sk_state_change(sk);
+        }
+
+        /* 
+         * It appears that its possible for remote machines to send disc
+         * init messages with no port identifier if we are in the CI and
+         * possibly also the CD state. Obviously we shouldn't reply with
+         * a message if we don't know what the end point is.
+         */
+        if (scp->addrrem) {
+                dn_nsp_send_disc(sk, NSP_DISCCONF, NSP_REASON_DC, GFP_ATOMIC);
+        }
+        scp->persist_fxn = dn_destroy_timer;
+        scp->persist = dn_nsp_persist(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 = DN_SK(sk);
+        unsigned short reason;
+
+        if (skb->len != 2)
+                goto out;
+
+        reason = dn_ntohs(*(__u16 *)skb->data);
+
+        sk->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->sk_shutdown |= SHUTDOWN_MASK;
+                case DN_CC:
+                        scp->state = DN_CN;
+        }
+
+        if (!sock_flag(sk, SOCK_DEAD)) {
+                if (sk->sk_socket->state != SS_UNCONNECTED)
+                        sk->sk_socket->state = SS_DISCONNECTING;
+                sk->sk_state_change(sk);
+        }
+
+        scp->persist_fxn = dn_destroy_timer;
+        scp->persist = dn_nsp_persist(sk);
+
+out:
+        kfree_skb(skb);
+}
+
+static void dn_nsp_linkservice(struct sock *sk, struct sk_buff *skb)
+{
+        struct dn_scp *scp = DN_SK(sk);
+        unsigned short segnum;
+        unsigned char lsflags;
+        signed char fcval;
+        int wake_up = 0;
+        char *ptr = skb->data;
+        unsigned char fctype = scp->services_rem & NSP_FC_MASK;
+
+        if (skb->len != 4)
+                goto out;
+
+        segnum = dn_ntohs(*(__u16 *)ptr);
+        ptr += 2;
+        lsflags = *(unsigned char *)ptr++;
+        fcval = *ptr;
+
+        /*
+         * Here we ignore erronous packets which should really
+         * should cause a connection abort. It is not critical 
+         * for now though.
+         */
+        if (lsflags & 0xf8)
+                goto out;
+
+        if (seq_next(scp->numoth_rcv, segnum)) {
+                seq_add(&scp->numoth_rcv, 1);
+                switch(lsflags & 0x04) { /* FCVAL INT */
+                case 0x00: /* Normal Request */
+                        switch(lsflags & 0x03) { /* FCVAL MOD */
+                        case 0x00: /* Request count */
+                                if (fcval < 0) {
+                                        unsigned char p_fcval = -fcval;
+                                        if ((scp->flowrem_dat > p_fcval) &&
+                                            (fctype == NSP_FC_SCMC)) {
+                                                scp->flowrem_dat -= p_fcval;
+                                        }
+                                } else if (fcval > 0) {
+                                        scp->flowrem_dat += fcval;
+                                        wake_up = 1;
+                                }
+                                break;
+                        case 0x01: /* Stop outgoing data */
+                                scp->flowrem_sw = DN_DONTSEND;
+                                break;
+                        case 0x02: /* Ok to start again */
+                                scp->flowrem_sw = DN_SEND;
+                                dn_nsp_output(sk);
+                                wake_up = 1;
+                        }
+                        break;
+                case 0x04: /* Interrupt Request */
+                        if (fcval > 0) {
+                                scp->flowrem_oth += fcval;
+                                wake_up = 1;
+                        }
+                        break;
+                }
+                if (wake_up && !sock_flag(sk, SOCK_DEAD))
+                        sk->sk_state_change(sk);
+        }
+
+        dn_nsp_send_oth_ack(sk);
+
+out:
+        kfree_skb(skb);
+}
+
+/*
+ * Copy of sock_queue_rcv_skb (from sock.h) without
+ * bh_lock_sock() (its already held when this is called) which
+ * also allows data and other data to be queued to a socket.
+ */
+static __inline__ int dn_queue_skb(struct sock *sk, struct sk_buff *skb, int sig, struct sk_buff_head *queue)
+{
+        int err;
+        
+        /* Cast skb->rcvbuf to unsigned... It's pointless, but reduces
+           number of warnings when compiling with -W --ANK
+         */
+        if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >=
+            (unsigned)sk->sk_rcvbuf) {
+                err = -ENOMEM;
+                goto out;
+        }
+
+        err = sk_filter(sk, skb, 0);
+        if (err)
+                goto out;
+
+        skb_set_owner_r(skb, sk);
+        skb_queue_tail(queue, skb);
+
+        /* This code only runs from BH or BH protected context.
+         * Therefore the plain read_lock is ok here. -DaveM
+         */
+        read_lock(&sk->sk_callback_lock);
+        if (!sock_flag(sk, SOCK_DEAD)) {
+                struct socket *sock = sk->sk_socket;
+                wake_up_interruptible(sk->sk_sleep);
+                if (sock && sock->fasync_list &&
+                    !test_bit(SOCK_ASYNC_WAITDATA, &sock->flags))
+                        __kill_fasync(sock->fasync_list, sig, 
+                                    (sig == SIGURG) ? POLL_PRI : POLL_IN);
+        }
+        read_unlock(&sk->sk_callback_lock);
+out:
+        return err;
+}
+
+static void dn_nsp_otherdata(struct sock *sk, struct sk_buff *skb)
+{
+        struct dn_scp *scp = DN_SK(sk);
+        unsigned short segnum;
+        struct dn_skb_cb *cb = DN_SKB_CB(skb);
+        int queued = 0;
+
+        if (skb->len < 2)
+                goto out;
+
+        cb->segnum = segnum = dn_ntohs(*(__u16 *)skb->data);
+        skb_pull(skb, 2);
+
+        if (seq_next(scp->numoth_rcv, segnum)) {
+
+                if (dn_queue_skb(sk, skb, SIGURG, &scp->other_receive_queue) == 0) {
+                        seq_add(&scp->numoth_rcv, 1);
+                        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 = DN_SKB_CB(skb);
+        struct dn_scp *scp = DN_SK(sk);
+
+        if (skb->len < 2)
+                goto out;
+
+        cb->segnum = segnum = dn_ntohs(*(__u16 *)skb->data);
+        skb_pull(skb, 2);
+
+        if (seq_next(scp->numdat_rcv, segnum)) {
+                if (dn_queue_skb(sk, skb, SIGIO, &sk->sk_receive_queue) == 0) {
+                        seq_add(&scp->numdat_rcv, 1);
+                        queued = 1;
+                }
+
+                if ((scp->flowloc_sw == DN_SEND) && dn_congested(sk)) {
+                        scp->flowloc_sw = DN_DONTSEND;
+                        dn_nsp_send_link(sk, DN_DONTSEND, 0);
+                }
+        }
+
+        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_conn_init(struct sock *sk, struct sk_buff *skb)
+{
+        struct dn_scp *scp = DN_SK(sk);
+
+        if (scp->state == DN_CI) {
+                scp->state = DN_NC;
+                sk->sk_state = TCP_CLOSE;
+                if (!sock_flag(sk, SOCK_DEAD))
+                        sk->sk_state_change(sk);
+        }
+
+        kfree_skb(skb);
+}
+
+static int dn_nsp_no_socket(struct sk_buff *skb, unsigned short reason)
+{
+        struct dn_skb_cb *cb = DN_SKB_CB(skb);
+        int ret = NET_RX_DROP;
+
+        /* Must not reply to returned packets */
+        if (cb->rt_flags & DN_RT_F_RTS)
+                goto out;
+
+        if ((reason != NSP_REASON_OK) && ((cb->nsp_flags & 0x0c) == 0x08)) {
+                switch(cb->nsp_flags & 0x70) {
+                        case 0x10:
+                        case 0x60: /* (Retransmitted) Connect Init */
+                                dn_nsp_return_disc(skb, NSP_DISCINIT, reason);
+                                ret = NET_RX_SUCCESS;
+                                break;
+                        case 0x20: /* Connect Confirm */
+                                dn_nsp_return_disc(skb, NSP_DISCCONF, reason);
+                                ret = NET_RX_SUCCESS;
+                                break;
+                }
+        }
+
+out:
+        kfree_skb(skb);
+        return ret;
+}
+
+static int dn_nsp_rx_packet(struct sk_buff *skb)
+{
+        struct dn_skb_cb *cb = DN_SKB_CB(skb);
+        struct sock *sk = NULL;
+        unsigned char *ptr = (unsigned char *)skb->data;
+        unsigned short reason = NSP_REASON_NL;
+
+        if (!pskb_may_pull(skb, 2))
+                goto free_out;
+
+        skb->h.raw    = skb->data;
+        cb->nsp_flags = *ptr++;
+
+        if (decnet_debug_level & 2)
+                printk(KERN_DEBUG "dn_nsp_rx: Message type 0x%02x\n", (int)cb->nsp_flags);
+
+        if (cb->nsp_flags & 0x83) 
+                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:
+                                if (unlikely(cb->rt_flags & DN_RT_F_RTS))
+                                        goto free_out;
+                                sk = dn_find_listener(skb, &reason);
+                                goto got_it;
+                }
+        }
+
+        if (!pskb_may_pull(skb, 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 (pskb_may_pull(skb, 5)) {
+                cb->src_port = *(unsigned short *)ptr;
+                ptr += 2;
+                skb_pull(skb, 5);
+        }
+
+        /*
+         * Returned packets...
+         * Swap src & dst and look up in the normal way.
+         */
+        if (unlikely(cb->rt_flags & DN_RT_F_RTS)) {
+                unsigned short tmp = cb->dst_port;
+                cb->dst_port = cb->src_port;
+                cb->src_port = tmp;
+                tmp = cb->dst;
+                cb->dst = cb->src;
+                cb->src = tmp;
+        }
+
+        /*
+         * Find the socket to which this skb is destined.
+         */
+        sk = dn_find_by_skb(skb);
+got_it:
+        if (sk != NULL) {
+                struct dn_scp *scp = DN_SK(sk);
+                int ret;
+
+                /* Reset backoff */
+                scp->nsp_rxtshift = 0;
+
+                /*
+                 * We linearize everything except data segments here.
+                 */
+                if (cb->nsp_flags & ~0x60) {
+                        if (unlikely(skb_is_nonlinear(skb)) &&
+                            skb_linearize(skb, GFP_ATOMIC) != 0)
+                                goto free_out;
+                }
+
+                bh_lock_sock(sk);
+                ret = NET_RX_SUCCESS;
+                if (decnet_debug_level & 8)
+                        printk(KERN_DEBUG "NSP: 0x%02x 0x%02x 0x%04x 0x%04x %d\n",
+                                (int)cb->rt_flags, (int)cb->nsp_flags, 
+                                (int)cb->src_port, (int)cb->dst_port, 
+                                !!sock_owned_by_user(sk));
+                if (!sock_owned_by_user(sk))
+                        ret = dn_nsp_backlog_rcv(sk, skb);
+                else
+                        sk_add_backlog(sk, skb);
+                bh_unlock_sock(sk);
+                sock_put(sk);
+
+                return ret;
+        }
+
+        return dn_nsp_no_socket(skb, reason);
+
+free_out:
+        kfree_skb(skb);
+        return NET_RX_DROP;
+}
+
+int dn_nsp_rx(struct sk_buff *skb)
+{
+        return NF_HOOK(PF_DECnet, NF_DN_LOCAL_IN, skb, skb->dev, NULL, dn_nsp_rx_packet);
+}
+
+/*
+ * 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 = DN_SK(sk);
+        struct dn_skb_cb *cb = DN_SKB_CB(skb);
+
+        if (cb->rt_flags & DN_RT_F_RTS) {
+                if (cb->nsp_flags == 0x18 || cb->nsp_flags == 0x68)
+                        dn_returned_conn_init(sk, skb);
+                else
+                        kfree_skb(skb);
+                return NET_RX_SUCCESS;
+        }
+
+        /*
+         * Control packet.
+         */
+        if ((cb->nsp_flags & 0x0c) == 0x08) {
+                switch(cb->nsp_flags & 0x70) {
+                        case 0x10:
+                        case 0x60:
+                                dn_nsp_conn_init(sk, skb);
+                                break;
+                        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;
+
+                /* both data and ack frames can kick a CC socket into RUN */
+                if ((scp->state == DN_CC) && !sock_flag(sk, SOCK_DEAD)) {
+                        scp->state = DN_RUN;
+                        sk->sk_state = TCP_ESTABLISHED;
+                        sk->sk_state_change(sk);
+                }
+
+                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.
+                 */
+                if ((cb->nsp_flags & 0x0c) == 0) {
+
+                        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 NET_RX_SUCCESS;
+}
+