![Gustavo A. R. Silva](/assets/img/avatar_default.png)
Make use of the swap macro and remove unnecessary variable tmp. This makes the code easier to read and maintain. This code was detected with the help of Coccinelle. Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com> Signed-off-by: David S. Miller <davem@davemloft.net>
915 lines
21 KiB
C
915 lines
21 KiB
C
/*
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* DECnet An implementation of the DECnet protocol suite for the LINUX
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* operating system. DECnet is implemented using the BSD Socket
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* interface as the means of communication with the user level.
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*
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* DECnet Network Services Protocol (Input)
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*
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* Author: Eduardo Marcelo Serrat <emserrat@geocities.com>
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*
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* Changes:
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*
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* Steve Whitehouse: Split into dn_nsp_in.c and dn_nsp_out.c from
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* original dn_nsp.c.
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* Steve Whitehouse: Updated to work with my new routing architecture.
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* Steve Whitehouse: Add changes from Eduardo Serrat's patches.
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* Steve Whitehouse: Put all ack handling code in a common routine.
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* Steve Whitehouse: Put other common bits into dn_nsp_rx()
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* Steve Whitehouse: More checks on skb->len to catch bogus packets
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* Fixed various race conditions and possible nasties.
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* Steve Whitehouse: Now handles returned conninit frames.
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* David S. Miller: New socket locking
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* Steve Whitehouse: Fixed lockup when socket filtering was enabled.
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* Paul Koning: Fix to push CC sockets into RUN when acks are
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* received.
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* Steve Whitehouse:
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* Patrick Caulfield: Checking conninits for correctness & sending of error
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* responses.
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* Steve Whitehouse: Added backlog congestion level return codes.
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* Patrick Caulfield:
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* Steve Whitehouse: Added flow control support (outbound)
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* Steve Whitehouse: Prepare for nonlinear skbs
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*/
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/******************************************************************************
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(c) 1995-1998 E.M. Serrat emserrat@geocities.com
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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*******************************************************************************/
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#include <linux/errno.h>
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#include <linux/types.h>
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#include <linux/socket.h>
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#include <linux/in.h>
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#include <linux/kernel.h>
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#include <linux/timer.h>
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#include <linux/string.h>
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#include <linux/sockios.h>
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#include <linux/net.h>
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#include <linux/netdevice.h>
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#include <linux/inet.h>
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#include <linux/route.h>
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#include <linux/slab.h>
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#include <net/sock.h>
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#include <net/tcp_states.h>
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#include <linux/fcntl.h>
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#include <linux/mm.h>
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#include <linux/termios.h>
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#include <linux/interrupt.h>
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#include <linux/proc_fs.h>
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#include <linux/stat.h>
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#include <linux/init.h>
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#include <linux/poll.h>
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#include <linux/netfilter_decnet.h>
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#include <net/neighbour.h>
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#include <net/dst.h>
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#include <net/dn.h>
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#include <net/dn_nsp.h>
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#include <net/dn_dev.h>
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#include <net/dn_route.h>
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extern int decnet_log_martians;
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static void dn_log_martian(struct sk_buff *skb, const char *msg)
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{
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if (decnet_log_martians) {
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char *devname = skb->dev ? skb->dev->name : "???";
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struct dn_skb_cb *cb = DN_SKB_CB(skb);
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net_info_ratelimited("DECnet: Martian packet (%s) dev=%s src=0x%04hx dst=0x%04hx srcport=0x%04hx dstport=0x%04hx\n",
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msg, devname,
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le16_to_cpu(cb->src),
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le16_to_cpu(cb->dst),
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le16_to_cpu(cb->src_port),
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le16_to_cpu(cb->dst_port));
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}
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}
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/*
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* For this function we've flipped the cross-subchannel bit
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* if the message is an otherdata or linkservice message. Thus
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* we can use it to work out what to update.
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*/
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static void dn_ack(struct sock *sk, struct sk_buff *skb, unsigned short ack)
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{
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struct dn_scp *scp = DN_SK(sk);
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unsigned short type = ((ack >> 12) & 0x0003);
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int wakeup = 0;
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switch (type) {
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case 0: /* ACK - Data */
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if (dn_after(ack, scp->ackrcv_dat)) {
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scp->ackrcv_dat = ack & 0x0fff;
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wakeup |= dn_nsp_check_xmit_queue(sk, skb,
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&scp->data_xmit_queue,
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ack);
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}
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break;
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case 1: /* NAK - Data */
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break;
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case 2: /* ACK - OtherData */
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if (dn_after(ack, scp->ackrcv_oth)) {
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scp->ackrcv_oth = ack & 0x0fff;
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wakeup |= dn_nsp_check_xmit_queue(sk, skb,
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&scp->other_xmit_queue,
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ack);
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}
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break;
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case 3: /* NAK - OtherData */
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break;
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}
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if (wakeup && !sock_flag(sk, SOCK_DEAD))
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sk->sk_state_change(sk);
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}
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/*
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* This function is a universal ack processor.
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*/
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static int dn_process_ack(struct sock *sk, struct sk_buff *skb, int oth)
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{
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__le16 *ptr = (__le16 *)skb->data;
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int len = 0;
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unsigned short ack;
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if (skb->len < 2)
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return len;
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if ((ack = le16_to_cpu(*ptr)) & 0x8000) {
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skb_pull(skb, 2);
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ptr++;
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len += 2;
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if ((ack & 0x4000) == 0) {
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if (oth)
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ack ^= 0x2000;
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dn_ack(sk, skb, ack);
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}
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}
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if (skb->len < 2)
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return len;
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if ((ack = le16_to_cpu(*ptr)) & 0x8000) {
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skb_pull(skb, 2);
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len += 2;
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if ((ack & 0x4000) == 0) {
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if (oth)
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ack ^= 0x2000;
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dn_ack(sk, skb, ack);
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}
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}
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return len;
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}
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/**
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* dn_check_idf - Check an image data field format is correct.
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* @pptr: Pointer to pointer to image data
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* @len: Pointer to length of image data
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* @max: The maximum allowed length of the data in the image data field
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* @follow_on: Check that this many bytes exist beyond the end of the image data
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*
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* Returns: 0 if ok, -1 on error
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*/
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static inline int dn_check_idf(unsigned char **pptr, int *len, unsigned char max, unsigned char follow_on)
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{
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unsigned char *ptr = *pptr;
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unsigned char flen = *ptr++;
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(*len)--;
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if (flen > max)
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return -1;
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if ((flen + follow_on) > *len)
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return -1;
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*len -= flen;
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*pptr = ptr + flen;
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return 0;
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}
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/*
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* Table of reason codes to pass back to node which sent us a badly
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* formed message, plus text messages for the log. A zero entry in
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* the reason field means "don't reply" otherwise a disc init is sent with
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* the specified reason code.
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*/
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static struct {
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unsigned short reason;
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const char *text;
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} ci_err_table[] = {
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{ 0, "CI: Truncated message" },
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{ NSP_REASON_ID, "CI: Destination username error" },
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{ NSP_REASON_ID, "CI: Destination username type" },
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{ NSP_REASON_US, "CI: Source username error" },
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{ 0, "CI: Truncated at menuver" },
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{ 0, "CI: Truncated before access or user data" },
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{ NSP_REASON_IO, "CI: Access data format error" },
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{ NSP_REASON_IO, "CI: User data format error" }
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};
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/*
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* This function uses a slightly different lookup method
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* to find its sockets, since it searches on object name/number
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* rather than port numbers. Various tests are done to ensure that
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* the incoming data is in the correct format before it is queued to
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* a socket.
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*/
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static struct sock *dn_find_listener(struct sk_buff *skb, unsigned short *reason)
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{
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struct dn_skb_cb *cb = DN_SKB_CB(skb);
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struct nsp_conn_init_msg *msg = (struct nsp_conn_init_msg *)skb->data;
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struct sockaddr_dn dstaddr;
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struct sockaddr_dn srcaddr;
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unsigned char type = 0;
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int dstlen;
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int srclen;
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unsigned char *ptr;
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int len;
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int err = 0;
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unsigned char menuver;
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memset(&dstaddr, 0, sizeof(struct sockaddr_dn));
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memset(&srcaddr, 0, sizeof(struct sockaddr_dn));
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/*
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* 1. Decode & remove message header
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*/
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cb->src_port = msg->srcaddr;
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cb->dst_port = msg->dstaddr;
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cb->services = msg->services;
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cb->info = msg->info;
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cb->segsize = le16_to_cpu(msg->segsize);
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if (!pskb_may_pull(skb, sizeof(*msg)))
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goto err_out;
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skb_pull(skb, sizeof(*msg));
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len = skb->len;
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ptr = skb->data;
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/*
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* 2. Check destination end username format
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*/
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dstlen = dn_username2sockaddr(ptr, len, &dstaddr, &type);
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err++;
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if (dstlen < 0)
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goto err_out;
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err++;
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if (type > 1)
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goto err_out;
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len -= dstlen;
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ptr += dstlen;
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/*
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* 3. Check source end username format
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*/
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srclen = dn_username2sockaddr(ptr, len, &srcaddr, &type);
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err++;
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if (srclen < 0)
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goto err_out;
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len -= srclen;
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ptr += srclen;
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err++;
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if (len < 1)
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goto err_out;
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menuver = *ptr;
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ptr++;
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len--;
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/*
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* 4. Check that optional data actually exists if menuver says it does
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*/
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err++;
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if ((menuver & (DN_MENUVER_ACC | DN_MENUVER_USR)) && (len < 1))
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goto err_out;
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/*
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* 5. Check optional access data format
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*/
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err++;
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if (menuver & DN_MENUVER_ACC) {
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if (dn_check_idf(&ptr, &len, 39, 1))
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goto err_out;
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if (dn_check_idf(&ptr, &len, 39, 1))
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goto err_out;
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if (dn_check_idf(&ptr, &len, 39, (menuver & DN_MENUVER_USR) ? 1 : 0))
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goto err_out;
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}
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/*
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* 6. Check optional user data format
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*/
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err++;
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if (menuver & DN_MENUVER_USR) {
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if (dn_check_idf(&ptr, &len, 16, 0))
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goto err_out;
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}
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/*
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* 7. Look up socket based on destination end username
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*/
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return dn_sklist_find_listener(&dstaddr);
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err_out:
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dn_log_martian(skb, ci_err_table[err].text);
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*reason = ci_err_table[err].reason;
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return NULL;
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}
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static void dn_nsp_conn_init(struct sock *sk, struct sk_buff *skb)
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{
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if (sk_acceptq_is_full(sk)) {
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kfree_skb(skb);
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return;
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}
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sk->sk_ack_backlog++;
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skb_queue_tail(&sk->sk_receive_queue, skb);
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sk->sk_state_change(sk);
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}
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static void dn_nsp_conn_conf(struct sock *sk, struct sk_buff *skb)
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{
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struct dn_skb_cb *cb = DN_SKB_CB(skb);
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struct dn_scp *scp = DN_SK(sk);
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unsigned char *ptr;
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if (skb->len < 4)
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goto out;
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ptr = skb->data;
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cb->services = *ptr++;
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cb->info = *ptr++;
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cb->segsize = le16_to_cpu(*(__le16 *)ptr);
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if ((scp->state == DN_CI) || (scp->state == DN_CD)) {
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scp->persist = 0;
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scp->addrrem = cb->src_port;
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sk->sk_state = TCP_ESTABLISHED;
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scp->state = DN_RUN;
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scp->services_rem = cb->services;
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scp->info_rem = cb->info;
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scp->segsize_rem = cb->segsize;
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if ((scp->services_rem & NSP_FC_MASK) == NSP_FC_NONE)
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scp->max_window = decnet_no_fc_max_cwnd;
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if (skb->len > 0) {
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u16 dlen = *skb->data;
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if ((dlen <= 16) && (dlen <= skb->len)) {
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scp->conndata_in.opt_optl = cpu_to_le16(dlen);
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skb_copy_from_linear_data_offset(skb, 1,
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scp->conndata_in.opt_data, dlen);
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}
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}
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dn_nsp_send_link(sk, DN_NOCHANGE, 0);
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if (!sock_flag(sk, SOCK_DEAD))
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sk->sk_state_change(sk);
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}
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out:
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kfree_skb(skb);
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}
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static void dn_nsp_conn_ack(struct sock *sk, struct sk_buff *skb)
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{
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struct dn_scp *scp = DN_SK(sk);
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if (scp->state == DN_CI) {
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scp->state = DN_CD;
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scp->persist = 0;
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}
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kfree_skb(skb);
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}
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static void dn_nsp_disc_init(struct sock *sk, struct sk_buff *skb)
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{
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struct dn_scp *scp = DN_SK(sk);
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struct dn_skb_cb *cb = DN_SKB_CB(skb);
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unsigned short reason;
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if (skb->len < 2)
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goto out;
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reason = le16_to_cpu(*(__le16 *)skb->data);
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skb_pull(skb, 2);
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scp->discdata_in.opt_status = cpu_to_le16(reason);
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scp->discdata_in.opt_optl = 0;
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memset(scp->discdata_in.opt_data, 0, 16);
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if (skb->len > 0) {
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u16 dlen = *skb->data;
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if ((dlen <= 16) && (dlen <= skb->len)) {
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scp->discdata_in.opt_optl = cpu_to_le16(dlen);
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skb_copy_from_linear_data_offset(skb, 1, scp->discdata_in.opt_data, dlen);
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}
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}
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scp->addrrem = cb->src_port;
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sk->sk_state = TCP_CLOSE;
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switch (scp->state) {
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case DN_CI:
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case DN_CD:
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scp->state = DN_RJ;
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sk->sk_err = ECONNREFUSED;
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break;
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case DN_RUN:
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sk->sk_shutdown |= SHUTDOWN_MASK;
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scp->state = DN_DN;
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break;
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case DN_DI:
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scp->state = DN_DIC;
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break;
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}
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if (!sock_flag(sk, SOCK_DEAD)) {
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if (sk->sk_socket->state != SS_UNCONNECTED)
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sk->sk_socket->state = SS_DISCONNECTING;
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sk->sk_state_change(sk);
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}
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/*
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* It appears that its possible for remote machines to send disc
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* init messages with no port identifier if we are in the CI and
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* possibly also the CD state. Obviously we shouldn't reply with
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* a message if we don't know what the end point is.
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*/
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if (scp->addrrem) {
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dn_nsp_send_disc(sk, NSP_DISCCONF, NSP_REASON_DC, GFP_ATOMIC);
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}
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scp->persist_fxn = dn_destroy_timer;
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scp->persist = dn_nsp_persist(sk);
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out:
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kfree_skb(skb);
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}
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/*
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* disc_conf messages are also called no_resources or no_link
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* messages depending upon the "reason" field.
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*/
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static void dn_nsp_disc_conf(struct sock *sk, struct sk_buff *skb)
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{
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struct dn_scp *scp = DN_SK(sk);
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unsigned short reason;
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if (skb->len != 2)
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goto out;
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reason = le16_to_cpu(*(__le16 *)skb->data);
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sk->sk_state = TCP_CLOSE;
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switch (scp->state) {
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case DN_CI:
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scp->state = DN_NR;
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break;
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case DN_DR:
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if (reason == NSP_REASON_DC)
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scp->state = DN_DRC;
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if (reason == NSP_REASON_NL)
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scp->state = DN_CN;
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break;
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case DN_DI:
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scp->state = DN_DIC;
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break;
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case DN_RUN:
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sk->sk_shutdown |= SHUTDOWN_MASK;
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case DN_CC:
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scp->state = DN_CN;
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}
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if (!sock_flag(sk, SOCK_DEAD)) {
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if (sk->sk_socket->state != SS_UNCONNECTED)
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sk->sk_socket->state = SS_DISCONNECTING;
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sk->sk_state_change(sk);
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}
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scp->persist_fxn = dn_destroy_timer;
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scp->persist = dn_nsp_persist(sk);
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out:
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kfree_skb(skb);
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}
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|
|
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 = le16_to_cpu(*(__le16 *)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 int)sk->sk_rcvbuf) {
|
|
err = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
err = sk_filter(sk, skb);
|
|
if (err)
|
|
goto out;
|
|
|
|
skb_set_owner_r(skb, sk);
|
|
skb_queue_tail(queue, skb);
|
|
|
|
if (!sock_flag(sk, SOCK_DEAD))
|
|
sk->sk_data_ready(sk);
|
|
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 = le16_to_cpu(*(__le16 *)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 = le16_to_cpu(*(__le16 *)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 net *net, struct sock *sk2,
|
|
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_reset_transport_header(skb);
|
|
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 = *(__le16 *)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 = *(__le16 *)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)) {
|
|
swap(cb->dst_port, cb->src_port);
|
|
swap(cb->dst, cb->src);
|
|
}
|
|
|
|
/*
|
|
* 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);
|
|
|
|
/* Reset backoff */
|
|
scp->nsp_rxtshift = 0;
|
|
|
|
/*
|
|
* We linearize everything except data segments here.
|
|
*/
|
|
if (cb->nsp_flags & ~0x60) {
|
|
if (unlikely(skb_linearize(skb)))
|
|
goto free_out;
|
|
}
|
|
|
|
return sk_receive_skb(sk, skb, 0);
|
|
}
|
|
|
|
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(NFPROTO_DECNET, NF_DN_LOCAL_IN,
|
|
&init_net, NULL, 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;
|
|
}
|
|
|