Release 4.11 net/decnet/dn_nsp_in.c

/*
 * 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/errno.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/kernel.h>
#include <linux/timer.h>
#include <linux/string.h>
#include <linux/sockios.h>
#include <linux/net.h>
#include <linux/netdevice.h>
#include <linux/inet.h>
#include <linux/route.h>
#include <linux/slab.h>
#include <net/sock.h>
#include <net/tcp_states.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) {
		char *devname = skb->dev ? skb->dev->name : "???";
		struct dn_skb_cb *cb = DN_SKB_CB(skb);
		net_info_ratelimited("DECnet: Martian packet (%s) dev=%s src=0x%04hx dst=0x%04hx srcport=0x%04hx dstport=0x%04hx\n",
				     msg, devname,
				     le16_to_cpu(cb->src),
				     le16_to_cpu(cb->dst),
				     le16_to_cpu(cb->src_port),
				     le16_to_cpu(cb->dst_port));
	}
}

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Linus Torvalds (pre-git)
69
81.18%
2
33.33%
Steven Whitehouse
8
9.41%
1
16.67%
Harvey Harrison
4
4.71%
1
16.67%
Linus Torvalds
3
3.53%
1
16.67%
Joe Perches
1
1.18%
1
16.67%
Total
85
100.00%
6
100.00%

/*
 * 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);
}

Contributors
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Linus Torvalds (pre-git)
157
93.45%
1
16.67%
Arnaldo Carvalho de Melo
4
2.38%
2
33.33%
Linus Torvalds
3
1.79%
1
16.67%
James Morris
2
1.19%
1
16.67%
David S. Miller
2
1.19%
1
16.67%
Total
168
100.00%
6
100.00%

/*
 * This function is a universal ack processor.
 */


static int dn_process_ack(struct sock *sk, struct sk_buff *skb, int oth)
{
	__le16 *ptr = (__le16 *)skb->data;
	int len = 0;
	unsigned short ack;

	if (skb->len < 2)
		return len;

	if ((ack = le16_to_cpu(*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 = le16_to_cpu(*ptr)) & 0x8000) {
		skb_pull(skb, 2);
		len += 2;
		if ((ack & 0x4000) == 0) {
			if (oth)
				ack ^= 0x2000;
			dn_ack(sk, skb, ack);
		}
	}

	return len;
}


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Linus Torvalds (pre-git)
176
97.78%
1
33.33%
Steven Whitehouse
2
1.11%
1
33.33%
Harvey Harrison
2
1.11%
1
33.33%
Total
180
100.00%
3
100.00%

/**
 * 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;
}

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100.00%

/*
 * 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  = le16_to_cpu(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;
}


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Steven Whitehouse
5
1.08%
1
16.67%
Linus Torvalds
3
0.65%
1
16.67%
Harvey Harrison
1
0.22%
1
16.67%
Total
462
100.00%
6
100.00%



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);
}

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6
11.32%
2
50.00%
Total
53
100.00%
4
100.00%



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 = le16_to_cpu(*(__le16 *)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) {
			u16 dlen = *skb->data;
			if ((dlen <= 16) && (dlen <= skb->len)) {
				scp->conndata_in.opt_optl = cpu_to_le16(dlen);
				skb_copy_from_linear_data_offset(skb, 1,
					      scp->conndata_in.opt_data, dlen);
			}
		}
		dn_nsp_send_link(sk, DN_NOCHANGE, 0);
		if (!sock_flag(sk, SOCK_DEAD))
			sk->sk_state_change(sk);
	}

out:
	kfree_skb(skb);
}

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Linus Torvalds (pre-git)
199
73.43%
1
10.00%
Linus Torvalds
54
19.93%
2
20.00%
Arnaldo Carvalho de Melo
10
3.69%
3
30.00%
Steven Whitehouse
4
1.48%
2
20.00%
Harvey Harrison
2
0.74%
1
10.00%
James Morris
2
0.74%
1
10.00%
Total
271
100.00%
10
100.00%



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);
}

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5.66%
1
50.00%
Total
53
100.00%
2
100.00%



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 = le16_to_cpu(*(__le16 *)skb->data);
	skb_pull(skb, 2);

	scp->discdata_in.opt_status = cpu_to_le16(reason);
	scp->discdata_in.opt_optl   = 0;
	memset(scp->discdata_in.opt_data, 0, 16);

	if (skb->len > 0) {
		u16 dlen = *skb->data;
		if ((dlen <= 16) && (dlen <= skb->len)) {
			scp->discdata_in.opt_optl = cpu_to_le16(dlen);
			skb_copy_from_linear_data_offset(skb, 1, scp->discdata_in.opt_data, dlen);
		}
	}

	scp->addrrem = cb->src_port;
	sk->sk_state = TCP_CLOSE;

	switch (scp->state) {
	case DN_CI