[linux-2.6-block.git] / drivers / net / wan / hdlc_ppp.c

/*
 * Generic HDLC support routines for Linux
 * Point-to-point protocol support
 *
 * Copyright (C) 1999 - 2008 Krzysztof Halasa <khc@pm.waw.pl>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of version 2 of the GNU General Public License
 * as published by the Free Software Foundation.
 */

#include <linux/errno.h>
#include <linux/hdlc.h>
#include <linux/if_arp.h>
#include <linux/inetdevice.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pkt_sched.h>
#include <linux/poll.h>
#include <linux/skbuff.h>
#include <linux/slab.h>
#include <linux/spinlock.h>

#define DEBUG_CP		0 /* also bytes# to dump */
#define DEBUG_STATE		0
#define DEBUG_HARD_HEADER	0

#define HDLC_ADDR_ALLSTATIONS	0xFF
#define HDLC_CTRL_UI		0x03

#define PID_LCP			0xC021
#define PID_IP			0x0021
#define PID_IPCP		0x8021
#define PID_IPV6		0x0057
#define PID_IPV6CP		0x8057

enum {IDX_LCP = 0, IDX_IPCP, IDX_IPV6CP, IDX_COUNT};
enum {CP_CONF_REQ = 1, CP_CONF_ACK, CP_CONF_NAK, CP_CONF_REJ, CP_TERM_REQ,
      CP_TERM_ACK, CP_CODE_REJ, LCP_PROTO_REJ, LCP_ECHO_REQ, LCP_ECHO_REPLY,
      LCP_DISC_REQ, CP_CODES};
#if DEBUG_CP
static const char *const code_names[CP_CODES] = {
	"0", "ConfReq", "ConfAck", "ConfNak", "ConfRej", "TermReq",
	"TermAck", "CodeRej", "ProtoRej", "EchoReq", "EchoReply", "Discard"
};
static char debug_buffer[64 + 3 * DEBUG_CP];
#endif

enum {LCP_OPTION_MRU = 1, LCP_OPTION_ACCM, LCP_OPTION_MAGIC = 5};

struct hdlc_header {
	u8 address;
	u8 control;
	__be16 protocol;
};

struct cp_header {
	u8 code;
	u8 id;
	__be16 len;
};


struct proto {
	struct net_device *dev;
	struct timer_list timer;
	unsigned long timeout;
	u16 pid;		/* protocol ID */
	u8 state;
	u8 cr_id;		/* ID of last Configuration-Request */
	u8 restart_counter;
};

struct ppp {
	struct proto protos[IDX_COUNT];
	spinlock_t lock;
	unsigned long last_pong;
	unsigned int req_timeout, cr_retries, term_retries;
	unsigned int keepalive_interval, keepalive_timeout;
	u8 seq;			/* local sequence number for requests */
	u8 echo_id;		/* ID of last Echo-Request (LCP) */
};

enum {CLOSED = 0, STOPPED, STOPPING, REQ_SENT, ACK_RECV, ACK_SENT, OPENED,
      STATES, STATE_MASK = 0xF};
enum {START = 0, STOP, TO_GOOD, TO_BAD, RCR_GOOD, RCR_BAD, RCA, RCN, RTR, RTA,
      RUC, RXJ_GOOD, RXJ_BAD, EVENTS};
enum {INV = 0x10, IRC = 0x20, ZRC = 0x40, SCR = 0x80, SCA = 0x100,
      SCN = 0x200, STR = 0x400, STA = 0x800, SCJ = 0x1000};

#if DEBUG_STATE
static const char *const state_names[STATES] = {
	"Closed", "Stopped", "Stopping", "ReqSent", "AckRecv", "AckSent",
	"Opened"
};
static const char *const event_names[EVENTS] = {
	"Start", "Stop", "TO+", "TO-", "RCR+", "RCR-", "RCA", "RCN",
	"RTR", "RTA", "RUC", "RXJ+", "RXJ-"
};
#endif

static struct sk_buff_head tx_queue; /* used when holding the spin lock */

static int ppp_ioctl(struct net_device *dev, struct ifreq *ifr);

static inline struct ppp* get_ppp(struct net_device *dev)
{
	return (struct ppp *)dev_to_hdlc(dev)->state;
}

static inline struct proto* get_proto(struct net_device *dev, u16 pid)
{
	struct ppp *ppp = get_ppp(dev);

	switch (pid) {
	case PID_LCP:
		return &ppp->protos[IDX_LCP];
	case PID_IPCP:
		return &ppp->protos[IDX_IPCP];
	case PID_IPV6CP:
		return &ppp->protos[IDX_IPV6CP];
	default:
		return NULL;
	}
}

static inline const char* proto_name(u16 pid)
{
	switch (pid) {
	case PID_LCP:
		return "LCP";
	case PID_IPCP:
		return "IPCP";
	case PID_IPV6CP:
		return "IPV6CP";
	default:
		return NULL;
	}
}

static __be16 ppp_type_trans(struct sk_buff *skb, struct net_device *dev)
{
	struct hdlc_header *data = (struct hdlc_header*)skb->data;

	if (skb->len < sizeof(struct hdlc_header))
		return htons(ETH_P_HDLC);
	if (data->address != HDLC_ADDR_ALLSTATIONS ||
	    data->control != HDLC_CTRL_UI)
		return htons(ETH_P_HDLC);

	switch (data->protocol) {
	case __constant_htons(PID_IP):
		skb_pull(skb, sizeof(struct hdlc_header));
		return htons(ETH_P_IP);

	case __constant_htons(PID_IPV6):
		skb_pull(skb, sizeof(struct hdlc_header));
		return htons(ETH_P_IPV6);

	default:
		return htons(ETH_P_HDLC);
	}
}


static int ppp_hard_header(struct sk_buff *skb, struct net_device *dev,
			   u16 type, const void *daddr, const void *saddr,
			   unsigned int len)
{
	struct hdlc_header *data;
#if DEBUG_HARD_HEADER
	printk(KERN_DEBUG "%s: ppp_hard_header() called\n", dev->name);
#endif

	skb_push(skb, sizeof(struct hdlc_header));
	data = (struct hdlc_header*)skb->data;

	data->address = HDLC_ADDR_ALLSTATIONS;
	data->control = HDLC_CTRL_UI;
	switch (type) {
	case ETH_P_IP:
		data->protocol = htons(PID_IP);
		break;
	case ETH_P_IPV6:
		data->protocol = htons(PID_IPV6);
		break;
	case PID_LCP:
	case PID_IPCP:
	case PID_IPV6CP:
		data->protocol = htons(type);
		break;
	default:		/* unknown protocol */
		data->protocol = 0;
	}
	return sizeof(struct hdlc_header);
}


static void ppp_tx_flush(void)
{
	struct sk_buff *skb;
	while ((skb = skb_dequeue(&tx_queue)) != NULL)
		dev_queue_xmit(skb);
}

static void ppp_tx_cp(struct net_device *dev, u16 pid, u8 code,
		      u8 id, unsigned int len, const void *data)
{
	struct sk_buff *skb;
	struct cp_header *cp;
	unsigned int magic_len = 0;
	static u32 magic;

#if DEBUG_CP
	int i;
	char *ptr;
#endif

	if (pid == PID_LCP && (code == LCP_ECHO_REQ || code == LCP_ECHO_REPLY))
		magic_len = sizeof(magic);

	skb = dev_alloc_skb(sizeof(struct hdlc_header) +
			    sizeof(struct cp_header) + magic_len + len);
	if (!skb) {
		printk(KERN_WARNING "%s: out of memory in ppp_tx_cp()\n",
		       dev->name);
		return;
	}
	skb_reserve(skb, sizeof(struct hdlc_header));

	cp = (struct cp_header *)skb_put(skb, sizeof(struct cp_header));
	cp->code = code;
	cp->id = id;
	cp->len = htons(sizeof(struct cp_header) + magic_len + len);

	if (magic_len)
		memcpy(skb_put(skb, magic_len), &magic, magic_len);
	if (len)
		memcpy(skb_put(skb, len), data, len);

#if DEBUG_CP
	BUG_ON(code >= CP_CODES);
	ptr = debug_buffer;
	*ptr = '\x0';
	for (i = 0; i < min_t(unsigned int, magic_len + len, DEBUG_CP); i++) {
		sprintf(ptr, " %02X", skb->data[sizeof(struct cp_header) + i]);
		ptr += strlen(ptr);
	}
	printk(KERN_DEBUG "%s: TX %s [%s id 0x%X]%s\n", dev->name,
	       proto_name(pid), code_names[code], id, debug_buffer);
#endif

	ppp_hard_header(skb, dev, pid, NULL, NULL, 0);

	skb->priority = TC_PRIO_CONTROL;
	skb->dev = dev;
	skb_reset_network_header(skb);
	skb_queue_tail(&tx_queue, skb);
}


/* State transition table (compare STD-51)
   Events                                   Actions
   TO+  = Timeout with counter > 0          irc = Initialize-Restart-Count
   TO-  = Timeout with counter expired      zrc = Zero-Restart-Count

   RCR+ = Receive-Configure-Request (Good)  scr = Send-Configure-Request
   RCR- = Receive-Configure-Request (Bad)
   RCA  = Receive-Configure-Ack             sca = Send-Configure-Ack
   RCN  = Receive-Configure-Nak/Rej         scn = Send-Configure-Nak/Rej

   RTR  = Receive-Terminate-Request         str = Send-Terminate-Request
   RTA  = Receive-Terminate-Ack             sta = Send-Terminate-Ack

   RUC  = Receive-Unknown-Code              scj = Send-Code-Reject
   RXJ+ = Receive-Code-Reject (permitted)
       or Receive-Protocol-Reject
   RXJ- = Receive-Code-Reject (catastrophic)
       or Receive-Protocol-Reject
*/
static int cp_table[EVENTS][STATES] = {
	/* CLOSED     STOPPED STOPPING REQ_SENT ACK_RECV ACK_SENT OPENED
	     0           1         2       3       4      5          6    */
	{IRC|SCR|3,     INV     , INV ,   INV   , INV ,  INV    ,   INV   }, /* START */
	{   INV   ,      0      ,  0  ,    0    ,  0  ,   0     ,    0    }, /* STOP */
	{   INV   ,     INV     ,STR|2,  SCR|3  ,SCR|3,  SCR|5  ,   INV   }, /* TO+ */
	{   INV   ,     INV     ,  1  ,    1    ,  1  ,    1    ,   INV   }, /* TO- */
	{  STA|0  ,IRC|SCR|SCA|5,  2  ,  SCA|5  ,SCA|6,  SCA|5  ,SCR|SCA|5}, /* RCR+ */
	{  STA|0  ,IRC|SCR|SCN|3,  2  ,  SCN|3  ,SCN|4,  SCN|3  ,SCR|SCN|3}, /* RCR- */
	{  STA|0  ,    STA|1    ,  2  ,  IRC|4  ,SCR|3,    6    , SCR|3   }, /* RCA */
	{  STA|0  ,    STA|1    ,  2  ,IRC|SCR|3,SCR|3,IRC|SCR|5, SCR|3   }, /* RCN */
	{  STA|0  ,    STA|1    ,STA|2,  STA|3  ,STA|3,  STA|3  ,ZRC|STA|2}, /* RTR */
	{    0    ,      1      ,  1  ,    3    ,  3  ,    5    ,  SCR|3  }, /* RTA */
	{  SCJ|0  ,    SCJ|1    ,SCJ|2,  SCJ|3  ,SCJ|4,  SCJ|5  ,  SCJ|6  }, /* RUC */
	{    0    ,      1      ,  2  ,    3    ,  3  ,    5    ,    6    }, /* RXJ+ */
	{    0    ,      1      ,  1  ,    1    ,  1  ,    1    ,IRC|STR|2}, /* RXJ- */
};


/* SCA: RCR+ must supply id, len and data
   SCN: RCR- must supply code, id, len and data
   STA: RTR must supply id
   SCJ: RUC must supply CP packet len and data */
static void ppp_cp_event(struct net_device *dev, u16 pid, u16 event, u8 code,
			 u8 id, unsigned int len, void *data)
{
	int old_state, action;
	struct ppp *ppp = get_ppp(dev);
	struct proto *proto = get_proto(dev, pid);

	old_state = proto->state;
	BUG_ON(old_state >= STATES);
	BUG_ON(event >= EVENTS);

#if DEBUG_STATE
	printk(KERN_DEBUG "%s: %s ppp_cp_event(%s) %s ...\n", dev->name,
	       proto_name(pid), event_names[event], state_names[proto->state]);
#endif

	action = cp_table[event][old_state];

	proto->state = action & STATE_MASK;
	if (action & (SCR | STR)) /* set Configure-Req/Terminate-Req timer */
		mod_timer(&proto->timer, proto->timeout =
			  jiffies + ppp->req_timeout * HZ);
	if (action & ZRC)
		proto->restart_counter = 0;
	if (action & IRC)
		proto->restart_counter = (proto->state == STOPPING) ?
			ppp->term_retries : ppp->cr_retries;

	if (action & SCR)	/* send Configure-Request */
		ppp_tx_cp(dev, pid, CP_CONF_REQ, proto->cr_id = ++ppp->seq,
			  0, NULL);
	if (action & SCA)	/* send Configure-Ack */
		ppp_tx_cp(dev, pid, CP_CONF_ACK, id, len, data);
	if (action & SCN)	/* send Configure-Nak/Reject */
		ppp_tx_cp(dev, pid, code, id, len, data);
	if (action & STR)	/* send Terminate-Request */
		ppp_tx_cp(dev, pid, CP_TERM_REQ, ++ppp->seq, 0, NULL);
	if (action & STA)	/* send Terminate-Ack */
		ppp_tx_cp(dev, pid, CP_TERM_ACK, id, 0, NULL);
	if (action & SCJ)	/* send Code-Reject */
		ppp_tx_cp(dev, pid, CP_CODE_REJ, ++ppp->seq, len, data);

	if (old_state != OPENED && proto->state == OPENED) {
		printk(KERN_INFO "%s: %s up\n", dev->name, proto_name(pid));
		if (pid == PID_LCP) {
			netif_dormant_off(dev);
			ppp_cp_event(dev, PID_IPCP, START, 0, 0, 0, NULL);
			ppp_cp_event(dev, PID_IPV6CP, START, 0, 0, 0, NULL);
			ppp->last_pong = jiffies;
			mod_timer(&proto->timer, proto->timeout =
				  jiffies + ppp->keepalive_interval * HZ);
		}
	}
	if (old_state == OPENED && proto->state != OPENED) {
		printk(KERN_INFO "%s: %s down\n", dev->name, proto_name(pid));
		if (pid == PID_LCP) {
			netif_dormant_on(dev);
			ppp_cp_event(dev, PID_IPCP, STOP, 0, 0, 0, NULL);
			ppp_cp_event(dev, PID_IPV6CP, STOP, 0, 0, 0, NULL);
		}
	}
	if (old_state != CLOSED && proto->state == CLOSED)
		del_timer(&proto->timer);

#if DEBUG_STATE
	printk(KERN_DEBUG "%s: %s ppp_cp_event(%s) ... %s\n", dev->name,
	       proto_name(pid), event_names[event], state_names[proto->state]);
#endif
}


static void ppp_cp_parse_cr(struct net_device *dev, u16 pid, u8 id,
			    unsigned int len, u8 *data)
{
	static u8 const valid_accm[6] = { LCP_OPTION_ACCM, 6, 0, 0, 0, 0 };
	u8 *opt, *out;
	unsigned int nak_len = 0, rej_len = 0;

	if (!(out = kmalloc(len, GFP_ATOMIC))) {
		dev->stats.rx_dropped++;
		return;	/* out of memory, ignore CR packet */
	}

	for (opt = data; len; len -= opt[1], opt += opt[1]) {
		if (len < 2 || len < opt[1]) {
			dev->stats.rx_errors++;
			return; /* bad packet, drop silently */
		}

		if (pid == PID_LCP)
			switch (opt[0]) {
			case LCP_OPTION_MRU:
				continue; /* MRU always OK and > 1500 bytes? */

			case LCP_OPTION_ACCM: /* async control character map */
				if (!memcmp(opt, valid_accm,
					    sizeof(valid_accm)))
					continue;
				if (!rej_len) { /* NAK it */
					memcpy(out + nak_len, valid_accm,
					       sizeof(valid_accm));
					nak_len += sizeof(valid_accm);
					continue;
				}
				break;
			case LCP_OPTION_MAGIC:
				if (opt[1] != 6 || (!opt[2] && !opt[3] &&
						    !opt[4] && !opt[5]))
					break; /* reject invalid magic number */
				continue;
			}
		/* reject this option */
		memcpy(out + rej_len, opt, opt[1]);
		rej_len += opt[1];
	}

	if (rej_len)
		ppp_cp_event(dev, pid, RCR_BAD, CP_CONF_REJ, id, rej_len, out);
	else if (nak_len)
		ppp_cp_event(dev, pid, RCR_BAD, CP_CONF_NAK, id, nak_len, out);
	else
		ppp_cp_event(dev, pid, RCR_GOOD, CP_CONF_ACK, id, len, data);

	kfree(out);
}

static int ppp_rx(struct sk_buff *skb)
{
	struct hdlc_header *hdr = (struct hdlc_header*)skb->data;
	struct net_device *dev = skb->dev;
	struct ppp *ppp = get_ppp(dev);
	struct proto *proto;
	struct cp_header *cp;
	unsigned long flags;
	unsigned int len;
	u16 pid;
#if DEBUG_CP
	int i;
	char *ptr;
#endif

	spin_lock_irqsave(&ppp->lock, flags);
	/* Check HDLC header */
	if (skb->len < sizeof(struct hdlc_header))
		goto rx_error;
	cp = (struct cp_header*)skb_pull(skb, sizeof(struct hdlc_header));
	if (hdr->address != HDLC_ADDR_ALLSTATIONS ||
	    hdr->control != HDLC_CTRL_UI)
		goto rx_error;

	pid = ntohs(hdr->protocol);
	proto = get_proto(dev, pid);
	if (!proto) {
		if (ppp->protos[IDX_LCP].state == OPENED)
			ppp_tx_cp(dev, PID_LCP, LCP_PROTO_REJ,
				  ++ppp->seq, skb->len + 2, &hdr->protocol);
		goto rx_error;
	}

	len = ntohs(cp->len);
	if (len < sizeof(struct cp_header) /* no complete CP header? */ ||
	    skb->len < len /* truncated packet? */)
		goto rx_error;
	skb_pull(skb, sizeof(struct cp_header));
	len -= sizeof(struct cp_header);

	/* HDLC and CP headers stripped from skb */
#if DEBUG_CP
	if (cp->code < CP_CODES)
		sprintf(debug_buffer, "[%s id 0x%X]", code_names[cp->code],
			cp->id);
	else
		sprintf(debug_buffer, "[code %u id 0x%X]", cp->code, cp->id);
	ptr = debug_buffer + strlen(debug_buffer);
	for (i = 0; i < min_t(unsigned int, len, DEBUG_CP); i++) {
		sprintf(ptr, " %02X", skb->data[i]);
		ptr += strlen(ptr);
	}
	printk(KERN_DEBUG "%s: RX %s %s\n", dev->name, proto_name(pid),
	       debug_buffer);
#endif

	/* LCP only */
	if (pid == PID_LCP)
		switch (cp->code) {
		case LCP_PROTO_REJ:
			pid = ntohs(*(__be16*)skb->data);
			if (pid == PID_LCP || pid == PID_IPCP ||
			    pid == PID_IPV6CP)
				ppp_cp_event(dev, pid, RXJ_BAD, 0, 0,
					     0, NULL);
			goto out;

		case LCP_ECHO_REQ: /* send Echo-Reply */
			if (len >= 4 && proto->state == OPENED)
				ppp_tx_cp(dev, PID_LCP, LCP_ECHO_REPLY,
					  cp->id, len - 4, skb->data + 4);
			goto out;

		case LCP_ECHO_REPLY:
			if (cp->id == ppp->echo_id)
				ppp->last_pong = jiffies;
			goto out;

		case LCP_DISC_REQ: /* discard */
			goto out;
		}

	/* LCP, IPCP and IPV6CP */
	switch (cp->code) {
	case CP_CONF_REQ:
		ppp_cp_parse_cr(dev, pid, cp->id, len, skb->data);
		goto out;

	case CP_CONF_ACK:
		if (cp->id == proto->cr_id)
			ppp_cp_event(dev, pid, RCA, 0, 0, 0, NULL);
		goto out;

	case CP_CONF_REJ:
	case CP_CONF_NAK:
		if (cp->id == proto->cr_id)
			ppp_cp_event(dev, pid, RCN, 0, 0, 0, NULL);
		goto out;

	case CP_TERM_REQ:
		ppp_cp_event(dev, pid, RTR, 0, cp->id, 0, NULL);
		goto out;

	case CP_TERM_ACK:
		ppp_cp_event(dev, pid, RTA, 0, 0, 0, NULL);
		goto out;

	case CP_CODE_REJ:
		ppp_cp_event(dev, pid, RXJ_BAD, 0, 0, 0, NULL);
		goto out;

	default:
		len += sizeof(struct cp_header);
		if (len > dev->mtu)
			len = dev->mtu;
		ppp_cp_event(dev, pid, RUC, 0, 0, len, cp);
		goto out;
	}
	goto out;

rx_error:
	dev->stats.rx_errors++;
out:
	spin_unlock_irqrestore(&ppp->lock, flags);
	dev_kfree_skb_any(skb);
	ppp_tx_flush();
	return NET_RX_DROP;
}


static void ppp_timer(unsigned long arg)
{
	struct proto *proto = (struct proto *)arg;
	struct ppp *ppp = get_ppp(proto->dev);
	unsigned long flags;

	spin_lock_irqsave(&ppp->lock, flags);
	switch (proto->state) {
	case STOPPING:
	case REQ_SENT:
	case ACK_RECV:
	case ACK_SENT:
		if (proto->restart_counter) {
			ppp_cp_event(proto->dev, proto->pid, TO_GOOD, 0, 0,
				     0, NULL);
			proto->restart_counter--;
		} else
			ppp_cp_event(proto->dev, proto->pid, TO_BAD, 0, 0,
				     0, NULL);
		break;

	case OPENED:
		if (proto->pid != PID_LCP)
			break;
		if (time_after(jiffies, ppp->last_pong +
			       ppp->keepalive_timeout * HZ)) {
			printk(KERN_INFO "%s: Link down\n", proto->dev->name);
			ppp_cp_event(proto->dev, PID_LCP, STOP, 0, 0, 0, NULL);
			ppp_cp_event(proto->dev, PID_LCP, START, 0, 0, 0, NULL);
		} else {	/* send keep-alive packet */
			ppp->echo_id = ++ppp->seq;
			ppp_tx_cp(proto->dev, PID_LCP, LCP_ECHO_REQ,
				  ppp->echo_id, 0, NULL);
			proto->timer.expires = jiffies +
				ppp->keepalive_interval * HZ;
			add_timer(&proto->timer);
		}
		break;
	}
	spin_unlock_irqrestore(&ppp->lock, flags);
	ppp_tx_flush();
}


static void ppp_start(struct net_device *dev)
{
	struct ppp *ppp = get_ppp(dev);
	int i;

	for (i = 0; i < IDX_COUNT; i++) {
		struct proto *proto = &ppp->protos[i];
		proto->dev = dev;
		init_timer(&proto->timer);
		proto->timer.function = ppp_timer;
		proto->timer.data = (unsigned long)proto;
		proto->state = CLOSED;
	}
	ppp->protos[IDX_LCP].pid = PID_LCP;
	ppp->protos[IDX_IPCP].pid = PID_IPCP;
	ppp->protos[IDX_IPV6CP].pid = PID_IPV6CP;

	ppp_cp_event(dev, PID_LCP, START, 0, 0, 0, NULL);
}

static void ppp_stop(struct net_device *dev)
{
	ppp_cp_event(dev, PID_LCP, STOP, 0, 0, 0, NULL);
}

static struct hdlc_proto proto = {
	.start		= ppp_start,
	.stop		= ppp_stop,
	.type_trans	= ppp_type_trans,
	.ioctl		= ppp_ioctl,
	.netif_rx	= ppp_rx,
	.module		= THIS_MODULE,
};

static const struct header_ops ppp_header_ops = {
	.create = ppp_hard_header,
};

static int ppp_ioctl(struct net_device *dev, struct ifreq *ifr)
{
	hdlc_device *hdlc = dev_to_hdlc(dev);
	struct ppp *ppp;
	int result;

	switch (ifr->ifr_settings.type) {
	case IF_GET_PROTO:
		if (dev_to_hdlc(dev)->proto != &proto)
			return -EINVAL;
		ifr->ifr_settings.type = IF_PROTO_PPP;
		return 0; /* return protocol only, no settable parameters */

	case IF_PROTO_PPP:
		if (!capable(CAP_NET_ADMIN))
			return -EPERM;

		if (dev->flags & IFF_UP)
			return -EBUSY;

		/* no settable parameters */

		result = hdlc->attach(dev, ENCODING_NRZ,PARITY_CRC16_PR1_CCITT);
		if (result)
			return result;

		result = attach_hdlc_protocol(dev, &proto, sizeof(struct ppp));
		if (result)
			return result;

		ppp = get_ppp(dev);
		spin_lock_init(&ppp->lock);
		ppp->req_timeout = 2;
		ppp->cr_retries = 10;
		ppp->term_retries = 2;
		ppp->keepalive_interval = 10;
		ppp->keepalive_timeout = 60;

		dev->hard_start_xmit = hdlc->xmit;
		dev->hard_header_len = sizeof(struct hdlc_header);
		dev->header_ops = &ppp_header_ops;
		dev->type = ARPHRD_PPP;
		netif_dormant_on(dev);
		return 0;
	}

	return -EINVAL;
}


static int __init mod_init(void)
{
	skb_queue_head_init(&tx_queue);
	register_hdlc_protocol(&proto);
	return 0;
}

static void __exit mod_exit(void)
{
	unregister_hdlc_protocol(&proto);
}


module_init(mod_init);
module_exit(mod_exit);

MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
MODULE_DESCRIPTION("PPP protocol support for generic HDLC");
MODULE_LICENSE("GPL v2");
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Generic HDLC support routines for Linux
	3	* Point-to-point protocol support
	4	*
e022c2f0	5	* Copyright (C) 1999 - 2008 Krzysztof Halasa <khc@pm.waw.pl>
1da177e4 LT	6	*
	7	* This program is free software; you can redistribute it and/or modify it
	8	* under the terms of version 2 of the GNU General Public License
	9	* as published by the Free Software Foundation.
	10	*/
	11
1da177e4	12	#include <linux/errno.h>
4dfce407	13	#include <linux/hdlc.h>
1da177e4	14	#include <linux/if_arp.h>
4dfce407	15	#include <linux/inetdevice.h>
1da177e4	16	#include <linux/init.h>
4dfce407 KH	17	#include <linux/kernel.h>
4dfce407 KH	18	#include <linux/module.h>
1da177e4	19	#include <linux/pkt_sched.h>
4dfce407	20	#include <linux/poll.h>
4dfce407 KH	21	#include <linux/skbuff.h>
4dfce407 KH	22	#include <linux/slab.h>
e022c2f0 KH	23	#include <linux/spinlock.h>
	24
	25	#define DEBUG_CP 0 /* also bytes# to dump */
	26	#define DEBUG_STATE 0
	27	#define DEBUG_HARD_HEADER 0
	28
	29	#define HDLC_ADDR_ALLSTATIONS 0xFF
	30	#define HDLC_CTRL_UI 0x03
	31
	32	#define PID_LCP 0xC021
	33	#define PID_IP 0x0021
	34	#define PID_IPCP 0x8021
	35	#define PID_IPV6 0x0057
	36	#define PID_IPV6CP 0x8057
	37
	38	enum {IDX_LCP = 0, IDX_IPCP, IDX_IPV6CP, IDX_COUNT};
	39	enum {CP_CONF_REQ = 1, CP_CONF_ACK, CP_CONF_NAK, CP_CONF_REJ, CP_TERM_REQ,
	40	CP_TERM_ACK, CP_CODE_REJ, LCP_PROTO_REJ, LCP_ECHO_REQ, LCP_ECHO_REPLY,
	41	LCP_DISC_REQ, CP_CODES};
	42	#if DEBUG_CP
	43	static const char *const code_names[CP_CODES] = {
	44	"0", "ConfReq", "ConfAck", "ConfNak", "ConfRej", "TermReq",
	45	"TermAck", "CodeRej", "ProtoRej", "EchoReq", "EchoReply", "Discard"
	46	};
	47	static char debug_buffer[64 + 3 * DEBUG_CP];
	48	#endif
	49
	50	enum {LCP_OPTION_MRU = 1, LCP_OPTION_ACCM, LCP_OPTION_MAGIC = 5};
	51
	52	struct hdlc_header {
	53	u8 address;
	54	u8 control;
	55	__be16 protocol;
	56	};
	57
	58	struct cp_header {
	59	u8 code;
	60	u8 id;
	61	__be16 len;
	62	};
	63
eb2a2fd9	64
e022c2f0 KH	65	struct proto {
	66	struct net_device *dev;
	67	struct timer_list timer;
	68	unsigned long timeout;
	69	u16 pid; /* protocol ID */
	70	u8 state;
	71	u8 cr_id; /* ID of last Configuration-Request */
	72	u8 restart_counter;
eb2a2fd9 KH	73	};
eb2a2fd9 KH	74
e022c2f0 KH	75	struct ppp {
	76	struct proto protos[IDX_COUNT];
	77	spinlock_t lock;
	78	unsigned long last_pong;
	79	unsigned int req_timeout, cr_retries, term_retries;
	80	unsigned int keepalive_interval, keepalive_timeout;
	81	u8 seq; /* local sequence number for requests */
	82	u8 echo_id; /* ID of last Echo-Request (LCP) */
	83	};
	84
	85	enum {CLOSED = 0, STOPPED, STOPPING, REQ_SENT, ACK_RECV, ACK_SENT, OPENED,
	86	STATES, STATE_MASK = 0xF};
	87	enum {START = 0, STOP, TO_GOOD, TO_BAD, RCR_GOOD, RCR_BAD, RCA, RCN, RTR, RTA,
	88	RUC, RXJ_GOOD, RXJ_BAD, EVENTS};
	89	enum {INV = 0x10, IRC = 0x20, ZRC = 0x40, SCR = 0x80, SCA = 0x100,
	90	SCN = 0x200, STR = 0x400, STA = 0x800, SCJ = 0x1000};
	91
	92	#if DEBUG_STATE
	93	static const char *const state_names[STATES] = {
	94	"Closed", "Stopped", "Stopping", "ReqSent", "AckRecv", "AckSent",
	95	"Opened"
	96	};
	97	static const char *const event_names[EVENTS] = {
	98	"Start", "Stop", "TO+", "TO-", "RCR+", "RCR-", "RCA", "RCN",
	99	"RTR", "RTA", "RUC", "RXJ+", "RXJ-"
	100	};
	101	#endif
	102
	103	static struct sk_buff_head tx_queue; /* used when holding the spin lock */
	104
eb2a2fd9 KH	105	static int ppp_ioctl(struct net_device dev, struct ifreq ifr);
eb2a2fd9 KH	106
e022c2f0 KH	107	static inline struct ppp* get_ppp(struct net_device *dev)
	108	{
	109	return (struct ppp *)dev_to_hdlc(dev)->state;
	110	}
eb2a2fd9	111
e022c2f0	112	static inline struct proto* get_proto(struct net_device *dev, u16 pid)
eb2a2fd9	113	{
e022c2f0 KH	114	struct ppp *ppp = get_ppp(dev);
	115
	116	switch (pid) {
	117	case PID_LCP:
	118	return &ppp->protos[IDX_LCP];
	119	case PID_IPCP:
	120	return &ppp->protos[IDX_IPCP];
	121	case PID_IPV6CP:
	122	return &ppp->protos[IDX_IPV6CP];
	123	default:
	124	return NULL;
	125	}
eb2a2fd9	126	}
1da177e4	127
e022c2f0 KH	128	static inline const char* proto_name(u16 pid)
	129	{
	130	switch (pid) {
	131	case PID_LCP:
	132	return "LCP";
	133	case PID_IPCP:
	134	return "IPCP";
	135	case PID_IPV6CP:
	136	return "IPV6CP";
	137	default:
	138	return NULL;
	139	}
	140	}
1da177e4	141
e022c2f0	142	static __be16 ppp_type_trans(struct sk_buff skb, struct net_device dev)
1da177e4	143	{
e022c2f0 KH	144	struct hdlc_header data = (struct hdlc_header)skb->data;
	145
	146	if (skb->len < sizeof(struct hdlc_header))
	147	return htons(ETH_P_HDLC);
	148	if (data->address != HDLC_ADDR_ALLSTATIONS \|\|
	149	data->control != HDLC_CTRL_UI)
	150	return htons(ETH_P_HDLC);
	151
	152	switch (data->protocol) {
	153	case __constant_htons(PID_IP):
	154	skb_pull(skb, sizeof(struct hdlc_header));
	155	return htons(ETH_P_IP);
1da177e4	156
e022c2f0 KH	157	case __constant_htons(PID_IPV6):
	158	skb_pull(skb, sizeof(struct hdlc_header));
	159	return htons(ETH_P_IPV6);
1da177e4	160
e022c2f0 KH	161	default:
e022c2f0 KH	162	return htons(ETH_P_HDLC);
1da177e4	163	}
e022c2f0	164	}
1da177e4	165
e022c2f0 KH	166
	167	static int ppp_hard_header(struct sk_buff skb, struct net_device dev,
	168	u16 type, const void daddr, const void saddr,
	169	unsigned int len)
	170	{
	171	struct hdlc_header *data;
	172	#if DEBUG_HARD_HEADER
	173	printk(KERN_DEBUG "%s: ppp_hard_header() called\n", dev->name);
	174	#endif
	175
	176	skb_push(skb, sizeof(struct hdlc_header));
	177	data = (struct hdlc_header*)skb->data;
	178
	179	data->address = HDLC_ADDR_ALLSTATIONS;
	180	data->control = HDLC_CTRL_UI;
	181	switch (type) {
	182	case ETH_P_IP:
	183	data->protocol = htons(PID_IP);
	184	break;
	185	case ETH_P_IPV6:
	186	data->protocol = htons(PID_IPV6);
	187	break;
	188	case PID_LCP:
	189	case PID_IPCP:
	190	case PID_IPV6CP:
	191	data->protocol = htons(type);
	192	break;
	193	default: /* unknown protocol */
	194	data->protocol = 0;
	195	}
	196	return sizeof(struct hdlc_header);
1da177e4 LT	197	}
	198
	199
e022c2f0 KH	200	static void ppp_tx_flush(void)
	201	{
	202	struct sk_buff *skb;
	203	while ((skb = skb_dequeue(&tx_queue)) != NULL)
	204	dev_queue_xmit(skb);
	205	}
1da177e4	206
e022c2f0 KH	207	static void ppp_tx_cp(struct net_device *dev, u16 pid, u8 code,
e022c2f0 KH	208	u8 id, unsigned int len, const void *data)
1da177e4	209	{
e022c2f0 KH	210	struct sk_buff *skb;
	211	struct cp_header *cp;
	212	unsigned int magic_len = 0;
	213	static u32 magic;
	214
	215	#if DEBUG_CP
	216	int i;
	217	char *ptr;
	218	#endif
	219
	220	if (pid == PID_LCP && (code == LCP_ECHO_REQ \|\| code == LCP_ECHO_REPLY))
	221	magic_len = sizeof(magic);
	222
	223	skb = dev_alloc_skb(sizeof(struct hdlc_header) +
	224	sizeof(struct cp_header) + magic_len + len);
	225	if (!skb) {
	226	printk(KERN_WARNING "%s: out of memory in ppp_tx_cp()\n",
	227	dev->name);
	228	return;
	229	}
	230	skb_reserve(skb, sizeof(struct hdlc_header));
	231
	232	cp = (struct cp_header *)skb_put(skb, sizeof(struct cp_header));
	233	cp->code = code;
	234	cp->id = id;
	235	cp->len = htons(sizeof(struct cp_header) + magic_len + len);
	236
	237	if (magic_len)
	238	memcpy(skb_put(skb, magic_len), &magic, magic_len);
	239	if (len)
	240	memcpy(skb_put(skb, len), data, len);
	241
	242	#if DEBUG_CP
	243	BUG_ON(code >= CP_CODES);
	244	ptr = debug_buffer;
	245	*ptr = '\x0';
	246	for (i = 0; i < min_t(unsigned int, magic_len + len, DEBUG_CP); i++) {
	247	sprintf(ptr, " %02X", skb->data[sizeof(struct cp_header) + i]);
	248	ptr += strlen(ptr);
	249	}
	250	printk(KERN_DEBUG "%s: TX %s [%s id 0x%X]%s\n", dev->name,
	251	proto_name(pid), code_names[code], id, debug_buffer);
	252	#endif
1da177e4	253
e022c2f0	254	ppp_hard_header(skb, dev, pid, NULL, NULL, 0);
3b04ddde	255
e022c2f0 KH	256	skb->priority = TC_PRIO_CONTROL;
	257	skb->dev = dev;
	258	skb_reset_network_header(skb);
	259	skb_queue_tail(&tx_queue, skb);
1da177e4 LT	260	}
	261
	262
e022c2f0 KH	263	/* State transition table (compare STD-51)
	264	Events Actions
	265	TO+ = Timeout with counter > 0 irc = Initialize-Restart-Count
	266	TO- = Timeout with counter expired zrc = Zero-Restart-Count
	267
	268	RCR+ = Receive-Configure-Request (Good) scr = Send-Configure-Request
	269	RCR- = Receive-Configure-Request (Bad)
	270	RCA = Receive-Configure-Ack sca = Send-Configure-Ack
	271	RCN = Receive-Configure-Nak/Rej scn = Send-Configure-Nak/Rej
	272
	273	RTR = Receive-Terminate-Request str = Send-Terminate-Request
	274	RTA = Receive-Terminate-Ack sta = Send-Terminate-Ack
	275
	276	RUC = Receive-Unknown-Code scj = Send-Code-Reject
	277	RXJ+ = Receive-Code-Reject (permitted)
	278	or Receive-Protocol-Reject
	279	RXJ- = Receive-Code-Reject (catastrophic)
	280	or Receive-Protocol-Reject
	281	*/
	282	static int cp_table[EVENTS][STATES] = {
	283	/* CLOSED STOPPED STOPPING REQ_SENT ACK_RECV ACK_SENT OPENED
	284	0 1 2 3 4 5 6 */
	285	{IRC\|SCR\|3, INV , INV , INV , INV , INV , INV }, /* START */
	286	{ INV , 0 , 0 , 0 , 0 , 0 , 0 }, /* STOP */
	287	{ INV , INV ,STR\|2, SCR\|3 ,SCR\|3, SCR\|5 , INV }, /* TO+ */
	288	{ INV , INV , 1 , 1 , 1 , 1 , INV }, /* TO- */
	289	{ STA\|0 ,IRC\|SCR\|SCA\|5, 2 , SCA\|5 ,SCA\|6, SCA\|5 ,SCR\|SCA\|5}, /* RCR+ */
	290	{ STA\|0 ,IRC\|SCR\|SCN\|3, 2 , SCN\|3 ,SCN\|4, SCN\|3 ,SCR\|SCN\|3}, /* RCR- */
	291	{ STA\|0 , STA\|1 , 2 , IRC\|4 ,SCR\|3, 6 , SCR\|3 }, /* RCA */
	292	{ STA\|0 , STA\|1 , 2 ,IRC\|SCR\|3,SCR\|3,IRC\|SCR\|5, SCR\|3 }, /* RCN */
	293	{ STA\|0 , STA\|1 ,STA\|2, STA\|3 ,STA\|3, STA\|3 ,ZRC\|STA\|2}, /* RTR */
	294	{ 0 , 1 , 1 , 3 , 3 , 5 , SCR\|3 }, /* RTA */
	295	{ SCJ\|0 , SCJ\|1 ,SCJ\|2, SCJ\|3 ,SCJ\|4, SCJ\|5 , SCJ\|6 }, /* RUC */
	296	{ 0 , 1 , 2 , 3 , 3 , 5 , 6 }, /* RXJ+ */
	297	{ 0 , 1 , 1 , 1 , 1 , 1 ,IRC\|STR\|2}, /* RXJ- */
	298	};
	299
1da177e4	300
e022c2f0 KH	301	/* SCA: RCR+ must supply id, len and data
	302	SCN: RCR- must supply code, id, len and data
	303	STA: RTR must supply id
	304	SCJ: RUC must supply CP packet len and data */
	305	static void ppp_cp_event(struct net_device *dev, u16 pid, u16 event, u8 code,
	306	u8 id, unsigned int len, void *data)
1da177e4	307	{
e022c2f0 KH	308	int old_state, action;
	309	struct ppp *ppp = get_ppp(dev);
	310	struct proto *proto = get_proto(dev, pid);
	311
	312	old_state = proto->state;
	313	BUG_ON(old_state >= STATES);
	314	BUG_ON(event >= EVENTS);
	315
	316	#if DEBUG_STATE
	317	printk(KERN_DEBUG "%s: %s ppp_cp_event(%s) %s ...\n", dev->name,
	318	proto_name(pid), event_names[event], state_names[proto->state]);
	319	#endif
	320
	321	action = cp_table[event][old_state];
	322
	323	proto->state = action & STATE_MASK;
	324	if (action & (SCR \| STR)) /* set Configure-Req/Terminate-Req timer */
	325	mod_timer(&proto->timer, proto->timeout =
	326	jiffies + ppp->req_timeout * HZ);
	327	if (action & ZRC)
	328	proto->restart_counter = 0;
	329	if (action & IRC)
	330	proto->restart_counter = (proto->state == STOPPING) ?
	331	ppp->term_retries : ppp->cr_retries;
	332
	333	if (action & SCR) /* send Configure-Request */
	334	ppp_tx_cp(dev, pid, CP_CONF_REQ, proto->cr_id = ++ppp->seq,
	335	0, NULL);
	336	if (action & SCA) /* send Configure-Ack */
	337	ppp_tx_cp(dev, pid, CP_CONF_ACK, id, len, data);
	338	if (action & SCN) /* send Configure-Nak/Reject */
	339	ppp_tx_cp(dev, pid, code, id, len, data);
	340	if (action & STR) /* send Terminate-Request */
	341	ppp_tx_cp(dev, pid, CP_TERM_REQ, ++ppp->seq, 0, NULL);
	342	if (action & STA) /* send Terminate-Ack */
	343	ppp_tx_cp(dev, pid, CP_TERM_ACK, id, 0, NULL);
	344	if (action & SCJ) /* send Code-Reject */
	345	ppp_tx_cp(dev, pid, CP_CODE_REJ, ++ppp->seq, len, data);
	346
	347	if (old_state != OPENED && proto->state == OPENED) {
	348	printk(KERN_INFO "%s: %s up\n", dev->name, proto_name(pid));
	349	if (pid == PID_LCP) {
	350	netif_dormant_off(dev);
	351	ppp_cp_event(dev, PID_IPCP, START, 0, 0, 0, NULL);
	352	ppp_cp_event(dev, PID_IPV6CP, START, 0, 0, 0, NULL);
	353	ppp->last_pong = jiffies;
	354	mod_timer(&proto->timer, proto->timeout =
	355	jiffies + ppp->keepalive_interval * HZ);
	356	}
	357	}
	358	if (old_state == OPENED && proto->state != OPENED) {
	359	printk(KERN_INFO "%s: %s down\n", dev->name, proto_name(pid));
	360	if (pid == PID_LCP) {
	361	netif_dormant_on(dev);
	362	ppp_cp_event(dev, PID_IPCP, STOP, 0, 0, 0, NULL);
	363	ppp_cp_event(dev, PID_IPV6CP, STOP, 0, 0, 0, NULL);
	364	}
	365	}
	366	if (old_state != CLOSED && proto->state == CLOSED)
	367	del_timer(&proto->timer);
	368
	369	#if DEBUG_STATE
	370	printk(KERN_DEBUG "%s: %s ppp_cp_event(%s) ... %s\n", dev->name,
	371	proto_name(pid), event_names[event], state_names[proto->state]);
372	#endif
1da177e4 LT	373	}
	374
	375
e022c2f0 KH	376	static void ppp_cp_parse_cr(struct net_device *dev, u16 pid, u8 id,
	377	unsigned int len, u8 *data)
	378	{
	379	static u8 const valid_accm[6] = { LCP_OPTION_ACCM, 6, 0, 0, 0, 0 };
	380	u8 opt, out;
	381	unsigned int nak_len = 0, rej_len = 0;
	382
	383	if (!(out = kmalloc(len, GFP_ATOMIC))) {
	384	dev->stats.rx_dropped++;
	385	return; /* out of memory, ignore CR packet */
	386	}
	387
	388	for (opt = data; len; len -= opt[1], opt += opt[1]) {
	389	if (len < 2 \|\| len < opt[1]) {
	390	dev->stats.rx_errors++;
	391	return; /* bad packet, drop silently */
	392	}
	393
	394	if (pid == PID_LCP)
	395	switch (opt[0]) {
	396	case LCP_OPTION_MRU:
	397	continue; /* MRU always OK and > 1500 bytes? */
	398
	399	case LCP_OPTION_ACCM: /* async control character map */
	400	if (!memcmp(opt, valid_accm,
	401	sizeof(valid_accm)))
	402	continue;
	403	if (!rej_len) { /* NAK it */
	404	memcpy(out + nak_len, valid_accm,
	405	sizeof(valid_accm));
	406	nak_len += sizeof(valid_accm);
	407	continue;
	408	}
	409	break;
	410	case LCP_OPTION_MAGIC:
	411	if (opt[1] != 6 \|\| (!opt[2] && !opt[3] &&
	412	!opt[4] && !opt[5]))
	413	break; /* reject invalid magic number */
	414	continue;
	415	}
	416	/* reject this option */
	417	memcpy(out + rej_len, opt, opt[1]);
	418	rej_len += opt[1];
	419	}
	420
	421	if (rej_len)
	422	ppp_cp_event(dev, pid, RCR_BAD, CP_CONF_REJ, id, rej_len, out);
	423	else if (nak_len)
	424	ppp_cp_event(dev, pid, RCR_BAD, CP_CONF_NAK, id, nak_len, out);
	425	else
	426	ppp_cp_event(dev, pid, RCR_GOOD, CP_CONF_ACK, id, len, data);
	427
	428	kfree(out);
	429	}
	430
	431	static int ppp_rx(struct sk_buff *skb)
	432	{
	433	struct hdlc_header hdr = (struct hdlc_header)skb->data;
	434	struct net_device *dev = skb->dev;
	435	struct ppp *ppp = get_ppp(dev);
	436	struct proto *proto;
	437	struct cp_header *cp;
	438	unsigned long flags;
	439	unsigned int len;
440	u16 pid;
441	#if DEBUG_CP
442	int i;
443	char *ptr;
444	#endif
445
446	spin_lock_irqsave(&ppp->lock, flags);
447	/* Check HDLC header */
448	if (skb->len < sizeof(struct hdlc_header))
449	goto rx_error;
450	cp = (struct cp_header*)skb_pull(skb, sizeof(struct hdlc_header));
451	if (hdr->address != HDLC_ADDR_ALLSTATIONS \|\|
452	hdr->control != HDLC_CTRL_UI)
453	goto rx_error;
454
455	pid = ntohs(hdr->protocol);
456	proto = get_proto(dev, pid);
457	if (!proto) {
458	if (ppp->protos[IDX_LCP].state == OPENED)
459	ppp_tx_cp(dev, PID_LCP, LCP_PROTO_REJ,
460	++ppp->seq, skb->len + 2, &hdr->protocol);
461	goto rx_error;
462	}
463
464	len = ntohs(cp->len);
465	if (len < sizeof(struct cp_header) /* no complete CP header? */ \|\|
466	skb->len < len /* truncated packet? */)
467	goto rx_error;
468	skb_pull(skb, sizeof(struct cp_header));
469	len -= sizeof(struct cp_header);
470
471	/* HDLC and CP headers stripped from skb */
472	#if DEBUG_CP
473	if (cp->code < CP_CODES)
474	sprintf(debug_buffer, "[%s id 0x%X]", code_names[cp->code],
475	cp->id);
476	else
477	sprintf(debug_buffer, "[code %u id 0x%X]", cp->code, cp->id);
478	ptr = debug_buffer + strlen(debug_buffer);
479	for (i = 0; i < min_t(unsigned int, len, DEBUG_CP); i++) {
480	sprintf(ptr, " %02X", skb->data[i]);
481	ptr += strlen(ptr);
482	}
483	printk(KERN_DEBUG "%s: RX %s %s\n", dev->name, proto_name(pid),
484	debug_buffer);
485	#endif
486
487	/* LCP only */
488	if (pid == PID_LCP)
489	switch (cp->code) {
490	case LCP_PROTO_REJ:
491	pid = ntohs((__be16)skb->data);
492	if (pid == PID_LCP \|\| pid == PID_IPCP \|\|
493	pid == PID_IPV6CP)
494	ppp_cp_event(dev, pid, RXJ_BAD, 0, 0,
495	0, NULL);
496	goto out;
497
498	case LCP_ECHO_REQ: /* send Echo-Reply */
499	if (len >= 4 && proto->state == OPENED)
500	ppp_tx_cp(dev, PID_LCP, LCP_ECHO_REPLY,
501	cp->id, len - 4, skb->data + 4);
502	goto out;
503
504	case LCP_ECHO_REPLY:
505	if (cp->id == ppp->echo_id)
506	ppp->last_pong = jiffies;
507	goto out;
508
509	case LCP_DISC_REQ: /* discard */
510	goto out;
511	}
512
513	/* LCP, IPCP and IPV6CP */
514	switch (cp->code) {
515	case CP_CONF_REQ:
516	ppp_cp_parse_cr(dev, pid, cp->id, len, skb->data);
517	goto out;
518
519	case CP_CONF_ACK:
520	if (cp->id == proto->cr_id)
521	ppp_cp_event(dev, pid, RCA, 0, 0, 0, NULL);
522	goto out;
523
524	case CP_CONF_REJ:
525	case CP_CONF_NAK:
526	if (cp->id == proto->cr_id)
527	ppp_cp_event(dev, pid, RCN, 0, 0, 0, NULL);
528	goto out;
529
530	case CP_TERM_REQ:
531	ppp_cp_event(dev, pid, RTR, 0, cp->id, 0, NULL);
532	goto out;
533
534	case CP_TERM_ACK:
535	ppp_cp_event(dev, pid, RTA, 0, 0, 0, NULL);
536	goto out;
537
538	case CP_CODE_REJ:
539	ppp_cp_event(dev, pid, RXJ_BAD, 0, 0, 0, NULL);
540	goto out;
541
542	default:
543	len += sizeof(struct cp_header);
544	if (len > dev->mtu)
545	len = dev->mtu;
546	ppp_cp_event(dev, pid, RUC, 0, 0, len, cp);
547	goto out;
548	}
549	goto out;
550
551	rx_error:
552	dev->stats.rx_errors++;
553	out:
554	spin_unlock_irqrestore(&ppp->lock, flags);
555	dev_kfree_skb_any(skb);
556	ppp_tx_flush();
557	return NET_RX_DROP;
558	}
559
560
561	static void ppp_timer(unsigned long arg)
562	{
563	struct proto proto = (struct proto )arg;
564	struct ppp *ppp = get_ppp(proto->dev);
565	unsigned long flags;
566
567	spin_lock_irqsave(&ppp->lock, flags);
568	switch (proto->state) {
569	case STOPPING:
570	case REQ_SENT:
571	case ACK_RECV:
572	case ACK_SENT:
573	if (proto->restart_counter) {
574	ppp_cp_event(proto->dev, proto->pid, TO_GOOD, 0, 0,
575	0, NULL);
576	proto->restart_counter--;
577	} else
578	ppp_cp_event(proto->dev, proto->pid, TO_BAD, 0, 0,
579	0, NULL);
580	break;
581
582	case OPENED:
583	if (proto->pid != PID_LCP)
584	break;
585	if (time_after(jiffies, ppp->last_pong +
586	ppp->keepalive_timeout * HZ)) {
587	printk(KERN_INFO "%s: Link down\n", proto->dev->name);
588	ppp_cp_event(proto->dev, PID_LCP, STOP, 0, 0, 0, NULL);
589	ppp_cp_event(proto->dev, PID_LCP, START, 0, 0, 0, NULL);
590	} else { /* send keep-alive packet */
591	ppp->echo_id = ++ppp->seq;
592	ppp_tx_cp(proto->dev, PID_LCP, LCP_ECHO_REQ,
593	ppp->echo_id, 0, NULL);
594	proto->timer.expires = jiffies +
595	ppp->keepalive_interval * HZ;
596	add_timer(&proto->timer);
597	}
598	break;
599	}
600	spin_unlock_irqrestore(&ppp->lock, flags);
601	ppp_tx_flush();
602	}
603
604
605	static void ppp_start(struct net_device *dev)
606	{
607	struct ppp *ppp = get_ppp(dev);
608	int i;
609
610	for (i = 0; i < IDX_COUNT; i++) {
611	struct proto *proto = &ppp->protos[i];
612	proto->dev = dev;
613	init_timer(&proto->timer);
614	proto->timer.function = ppp_timer;
615	proto->timer.data = (unsigned long)proto;
616	proto->state = CLOSED;
617	}
618	ppp->protos[IDX_LCP].pid = PID_LCP;
619	ppp->protos[IDX_IPCP].pid = PID_IPCP;
620	ppp->protos[IDX_IPV6CP].pid = PID_IPV6CP;
621
622	ppp_cp_event(dev, PID_LCP, START, 0, 0, 0, NULL);
623	}
624
625	static void ppp_stop(struct net_device *dev)
626	{
627	ppp_cp_event(dev, PID_LCP, STOP, 0, 0, 0, NULL);
628	}
1da177e4	629
eb2a2fd9	630	static struct hdlc_proto proto = {
e022c2f0 KH	631	.start = ppp_start,
e022c2f0 KH	632	.stop = ppp_stop,
eb2a2fd9 KH	633	.type_trans = ppp_type_trans,
eb2a2fd9 KH	634	.ioctl = ppp_ioctl,
e022c2f0	635	.netif_rx = ppp_rx,
eb2a2fd9 KH	636	.module = THIS_MODULE,
	637	};
	638
e022c2f0 KH	639	static const struct header_ops ppp_header_ops = {
	640	.create = ppp_hard_header,
	641	};
eb2a2fd9 KH	642
eb2a2fd9 KH	643	static int ppp_ioctl(struct net_device dev, struct ifreq ifr)
1da177e4 LT	644	{
1da177e4 LT	645	hdlc_device *hdlc = dev_to_hdlc(dev);
e022c2f0	646	struct ppp *ppp;
1da177e4 LT	647	int result;
	648
	649	switch (ifr->ifr_settings.type) {
	650	case IF_GET_PROTO:
eb2a2fd9 KH	651	if (dev_to_hdlc(dev)->proto != &proto)
eb2a2fd9 KH	652	return -EINVAL;
1da177e4 LT	653	ifr->ifr_settings.type = IF_PROTO_PPP;
	654	return 0; /* return protocol only, no settable parameters */
	655
	656	case IF_PROTO_PPP:
e022c2f0	657	if (!capable(CAP_NET_ADMIN))
1da177e4 LT	658	return -EPERM;
1da177e4 LT	659
e022c2f0	660	if (dev->flags & IFF_UP)
1da177e4 LT	661	return -EBUSY;
	662
	663	/* no settable parameters */
	664
e022c2f0	665	result = hdlc->attach(dev, ENCODING_NRZ,PARITY_CRC16_PR1_CCITT);
1da177e4 LT	666	if (result)
	667	return result;
	668
e022c2f0	669	result = attach_hdlc_protocol(dev, &proto, sizeof(struct ppp));
eb2a2fd9 KH	670	if (result)
eb2a2fd9 KH	671	return result;
e022c2f0 KH	672
	673	ppp = get_ppp(dev);
	674	spin_lock_init(&ppp->lock);
	675	ppp->req_timeout = 2;
	676	ppp->cr_retries = 10;
	677	ppp->term_retries = 2;
	678	ppp->keepalive_interval = 10;
	679	ppp->keepalive_timeout = 60;
	680
1da177e4	681	dev->hard_start_xmit = hdlc->xmit;
e022c2f0 KH	682	dev->hard_header_len = sizeof(struct hdlc_header);
e022c2f0 KH	683	dev->header_ops = &ppp_header_ops;
1da177e4	684	dev->type = ARPHRD_PPP;
e022c2f0	685	netif_dormant_on(dev);
1da177e4 LT	686	return 0;
	687	}
	688
	689	return -EINVAL;
	690	}
eb2a2fd9 KH	691
	692
	693	static int __init mod_init(void)
	694	{
e022c2f0	695	skb_queue_head_init(&tx_queue);
eb2a2fd9 KH	696	register_hdlc_protocol(&proto);
	697	return 0;
	698	}
	699
eb2a2fd9 KH	700	static void __exit mod_exit(void)
	701	{
	702	unregister_hdlc_protocol(&proto);
	703	}
	704
	705
	706	module_init(mod_init);
	707	module_exit(mod_exit);
	708
	709	MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
	710	MODULE_DESCRIPTION("PPP protocol support for generic HDLC");
	711	MODULE_LICENSE("GPL v2");