WAN: new synchronous PPP implementation for generic HDLC.

Signed-off-by: Krzysztof Hałasa <khc@pm.waw.pl>

3 files changed, 606 insertions, 52 deletions

diff --git a/Documentation/networking/generic-hdlc.txt b/Documentation/networking/generic-hdlc.txt
index 31bc8b759b75..4eb3cc40b702 100644
--- a/Documentation/networking/generic-hdlc.txt
+++ b/Documentation/networking/generic-hdlc.txt
@@ -3,15 +3,15 @@ Krzysztof Halasa <khc@pm.waw.pl>
 
 
 Generic HDLC layer currently supports:
-1. Frame Relay (ANSI, CCITT, Cisco and no LMI).
+1. Frame Relay (ANSI, CCITT, Cisco and no LMI)
    - Normal (routed) and Ethernet-bridged (Ethernet device emulation)
      interfaces can share a single PVC.
    - ARP support (no InARP support in the kernel - there is an
      experimental InARP user-space daemon available on:
      http://www.kernel.org/pub/linux/utils/net/hdlc/).
-2. raw HDLC - either IP (IPv4) interface or Ethernet device emulation.
-3. Cisco HDLC.
-4. PPP (uses syncppp.c).
+2. raw HDLC - either IP (IPv4) interface or Ethernet device emulation
+3. Cisco HDLC
+4. PPP
 5. X.25 (uses X.25 routines).
 
 Generic HDLC is a protocol driver only - it needs a low-level driver
diff --git a/drivers/net/wan/Makefile b/drivers/net/wan/Makefile
index 102549605d09..cec16818a130 100644
--- a/drivers/net/wan/Makefile
+++ b/drivers/net/wan/Makefile
@@ -14,7 +14,7 @@ obj-$(CONFIG_HDLC_RAW)		+= hdlc_raw.o
 obj-$(CONFIG_HDLC_RAW_ETH)      += hdlc_raw_eth.o
 obj-$(CONFIG_HDLC_CISCO)        += hdlc_cisco.o
 obj-$(CONFIG_HDLC_FR)           += hdlc_fr.o
-obj-$(CONFIG_HDLC_PPP)          += hdlc_ppp.o   syncppp.o
+obj-$(CONFIG_HDLC_PPP)          += hdlc_ppp.o
 obj-$(CONFIG_HDLC_X25)          += hdlc_x25.o
 
 pc300-y                         := pc300_drv.o
diff --git a/drivers/net/wan/hdlc_ppp.c b/drivers/net/wan/hdlc_ppp.c
index 4efe9e6d32d5..72fae217f1c4 100644
--- a/drivers/net/wan/hdlc_ppp.c
+++ b/drivers/net/wan/hdlc_ppp.c
@@ -2,7 +2,7 @@
  * Generic HDLC support routines for Linux
  * Point-to-point protocol support
  *
- * Copyright (C) 1999 - 2006 Krzysztof Halasa <khc@pm.waw.pl>
+ * 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
@@ -18,87 +18,632 @@
 #include <linux/module.h>
 #include <linux/pkt_sched.h>
 #include <linux/poll.h>
-#include <linux/rtnetlink.h>
 #include <linux/skbuff.h>
 #include <linux/slab.h>
-#include <net/syncppp.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 ppp_state {
-        struct ppp_device pppdev;
-        struct ppp_device *syncppp_ptr;
-        int (*old_change_mtu)(struct net_device *dev, int new_mtu);
+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 ppp_state* state(hdlc_device *hdlc)
+static inline struct proto* get_proto(struct net_device *dev, u16 pid)
 {
-        return(struct ppp_state *)(hdlc->state);
+        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 int ppp_open(struct net_device *dev)
+static __be16 ppp_type_trans(struct sk_buff *skb, struct net_device *dev)
 {
-        hdlc_device *hdlc = dev_to_hdlc(dev);
-        int (*old_ioctl)(struct net_device *, struct ifreq *, int);
-        int result;
+        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);
 
-        dev->ml_priv = &state(hdlc)->syncppp_ptr;
-        state(hdlc)->syncppp_ptr = &state(hdlc)->pppdev;
-        state(hdlc)->pppdev.dev = dev;
+        case __constant_htons(PID_IPV6):
+                skb_pull(skb, sizeof(struct hdlc_header));
+                return htons(ETH_P_IPV6);
 
-        old_ioctl = dev->do_ioctl;
-        state(hdlc)->old_change_mtu = dev->change_mtu;
-        sppp_attach(&state(hdlc)->pppdev);
-        /* sppp_attach nukes them. We don't need syncppp's ioctl */
-        dev->do_ioctl = old_ioctl;
-        state(hdlc)->pppdev.sppp.pp_flags &= ~PP_CISCO;
-        dev->type = ARPHRD_PPP;
-        result = sppp_open(dev);
-        if (result) {
-                sppp_detach(dev);
-                return result;
+        default:
+                return htons(ETH_P_HDLC);
         }
+}
 
-        return 0;
+
+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_close(struct net_device *dev)
+static void ppp_tx_cp(struct net_device *dev, u16 pid, u8 code,
+                      u8 id, unsigned int len, const void *data)
 {
-        hdlc_device *hdlc = dev_to_hdlc(dev);
+        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
 
-        sppp_close(dev);
-        sppp_detach(dev);
+        ppp_hard_header(skb, dev, pid, NULL, NULL, 0);
 
-        dev->change_mtu = state(hdlc)->old_change_mtu;
-        dev->mtu = HDLC_MAX_MTU;
-        dev->hard_header_len = 16;
+        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- */
+};
+
 
-static __be16 ppp_type_trans(struct sk_buff *skb, struct net_device *dev)
+/* 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)
 {
-        return __constant_htons(ETH_P_WAN_PPP);
+        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 = {
-        .open           = ppp_open,
-        .close          = ppp_close,
+        .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) {
@@ -109,25 +654,35 @@ static int ppp_ioctl(struct net_device *dev, struct ifreq *ifr)
                 return 0; /* return protocol only, no settable parameters */
 
         case IF_PROTO_PPP:
-                if(!capable(CAP_NET_ADMIN))
+                if (!capable(CAP_NET_ADMIN))
                         return -EPERM;
 
-                if(dev->flags & IFF_UP)
+                if (dev->flags & IFF_UP)
                         return -EBUSY;
 
                 /* no settable parameters */
 
-                result=hdlc->attach(dev, ENCODING_NRZ,PARITY_CRC16_PR1_CCITT);
+                result = hdlc->attach(dev, ENCODING_NRZ,PARITY_CRC16_PR1_CCITT);
                 if (result)
                         return result;
 
-                result = attach_hdlc_protocol(dev, &proto,
-                                              sizeof(struct ppp_state));
+                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_off(dev);
+                netif_dormant_on(dev);
                 return 0;
         }
 
@@ -137,12 +692,11 @@ static int ppp_ioctl(struct net_device *dev, struct ifreq *ifr)
 
 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);