Linux-2.6.12-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!
diff --git a/net/decnet/dn_nsp_in.c b/net/decnet/dn_nsp_in.c
new file mode 100644
index 0000000..202dbde
--- /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;
+}
+