Logo Search packages:      
Sourcecode: linux version File versions  Download package

hdlc_fr.c

/*
 * Generic HDLC support routines for Linux
 * Frame Relay support
 *
 * Copyright (C) 1999 - 2006 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.
 *

            Theory of PVC state

 DCE mode:

 (exist,new) -> 0,0 when "PVC create" or if "link unreliable"
         0,x -> 1,1 if "link reliable" when sending FULL STATUS
         1,1 -> 1,0 if received FULL STATUS ACK

 (active)    -> 0 when "ifconfig PVC down" or "link unreliable" or "PVC create"
             -> 1 when "PVC up" and (exist,new) = 1,0

 DTE mode:
 (exist,new,active) = FULL STATUS if "link reliable"
                = 0, 0, 0 if "link unreliable"
 No LMI:
 active = open and "link reliable"
 exist = new = not used

 CCITT LMI: ITU-T Q.933 Annex A
 ANSI LMI: ANSI T1.617 Annex D
 CISCO LMI: the original, aka "Gang of Four" LMI

*/

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/poll.h>
#include <linux/errno.h>
#include <linux/if_arp.h>
#include <linux/init.h>
#include <linux/skbuff.h>
#include <linux/pkt_sched.h>
#include <linux/random.h>
#include <linux/inetdevice.h>
#include <linux/lapb.h>
#include <linux/rtnetlink.h>
#include <linux/etherdevice.h>
#include <linux/hdlc.h>

#undef DEBUG_PKT
#undef DEBUG_ECN
#undef DEBUG_LINK
#undef DEBUG_PROTO
#undef DEBUG_PVC

#define FR_UI                 0x03
#define FR_PAD                0x00

#define NLPID_IP        0xCC
#define NLPID_IPV6            0x8E
#define NLPID_SNAP            0x80
#define NLPID_PAD       0x00
#define NLPID_CCITT_ANSI_LMI  0x08
#define NLPID_CISCO_LMI       0x09


#define LMI_CCITT_ANSI_DLCI      0 /* LMI DLCI */
#define LMI_CISCO_DLCI        1023

#define LMI_CALLREF           0x00 /* Call Reference */
#define LMI_ANSI_LOCKSHIFT    0x95 /* ANSI locking shift */
#define LMI_ANSI_CISCO_REPTYPE      0x01 /* report type */
#define LMI_CCITT_REPTYPE     0x51
#define LMI_ANSI_CISCO_ALIVE  0x03 /* keep alive */
#define LMI_CCITT_ALIVE       0x53
#define LMI_ANSI_CISCO_PVCSTAT      0x07 /* PVC status */
#define LMI_CCITT_PVCSTAT     0x57

#define LMI_FULLREP           0x00 /* full report  */
#define LMI_INTEGRITY         0x01 /* link integrity report */
#define LMI_SINGLE            0x02 /* single PVC report */

#define LMI_STATUS_ENQUIRY      0x75
#define LMI_STATUS              0x7D /* reply */

#define LMI_REPT_LEN               1 /* report type element length */
#define LMI_INTEG_LEN              2 /* link integrity element length */

#define LMI_CCITT_CISCO_LENGTH        13 /* LMI frame lengths */
#define LMI_ANSI_LENGTH         14


typedef struct {
#if defined(__LITTLE_ENDIAN_BITFIELD)
      unsigned ea1:     1;
      unsigned cr:      1;
      unsigned dlcih:   6;
  
      unsigned ea2:     1;
      unsigned de:      1;
      unsigned becn:    1;
      unsigned fecn:    1;
      unsigned dlcil:   4;
#else
      unsigned dlcih:   6;
      unsigned cr:      1;
      unsigned ea1:     1;

      unsigned dlcil:   4;
      unsigned fecn:    1;
      unsigned becn:    1;
      unsigned de:      1;
      unsigned ea2:     1;
#endif
}__attribute__ ((packed)) fr_hdr;


typedef struct pvc_device_struct {
      struct net_device *frad;
      struct net_device *main;
      struct net_device *ether;     /* bridged Ethernet interface */
      struct pvc_device_struct *next;     /* Sorted in ascending DLCI order */
      int dlci;
      int open_count;

      struct {
            unsigned int new: 1;
            unsigned int active: 1;
            unsigned int exist: 1;
            unsigned int deleted: 1;
            unsigned int fecn: 1;
            unsigned int becn: 1;
            unsigned int bandwidth; /* Cisco LMI reporting only */
      }state;
}pvc_device;


struct frad_state {
      fr_proto settings;
      pvc_device *first_pvc;
      int dce_pvc_count;

      struct timer_list timer;
      unsigned long last_poll;
      int reliable;
      int dce_changed;
      int request;
      int fullrep_sent;
      u32 last_errors; /* last errors bit list */
      u8 n391cnt;
      u8 txseq; /* TX sequence number */
      u8 rxseq; /* RX sequence number */
};


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


static inline u16 q922_to_dlci(u8 *hdr)
{
      return ((hdr[0] & 0xFC) << 2) | ((hdr[1] & 0xF0) >> 4);
}


static inline void dlci_to_q922(u8 *hdr, u16 dlci)
{
      hdr[0] = (dlci >> 2) & 0xFC;
      hdr[1] = ((dlci << 4) & 0xF0) | 0x01;
}


static inline struct frad_state * state(hdlc_device *hdlc)
{
      return(struct frad_state *)(hdlc->state);
}


static __inline__ pvc_device* dev_to_pvc(struct net_device *dev)
{
      return dev->priv;
}


static inline pvc_device* find_pvc(hdlc_device *hdlc, u16 dlci)
{
      pvc_device *pvc = state(hdlc)->first_pvc;

      while (pvc) {
            if (pvc->dlci == dlci)
                  return pvc;
            if (pvc->dlci > dlci)
                  return NULL; /* the listed is sorted */
            pvc = pvc->next;
      }

      return NULL;
}


static pvc_device* add_pvc(struct net_device *dev, u16 dlci)
{
      hdlc_device *hdlc = dev_to_hdlc(dev);
      pvc_device *pvc, **pvc_p = &state(hdlc)->first_pvc;

      while (*pvc_p) {
            if ((*pvc_p)->dlci == dlci)
                  return *pvc_p;
            if ((*pvc_p)->dlci > dlci)
                  break;      /* the list is sorted */
            pvc_p = &(*pvc_p)->next;
      }

      pvc = kzalloc(sizeof(pvc_device), GFP_ATOMIC);
#ifdef DEBUG_PVC
      printk(KERN_DEBUG "add_pvc: allocated pvc %p, frad %p\n", pvc, dev);
#endif
      if (!pvc)
            return NULL;

      pvc->dlci = dlci;
      pvc->frad = dev;
      pvc->next = *pvc_p;     /* Put it in the chain */
      *pvc_p = pvc;
      return pvc;
}


static inline int pvc_is_used(pvc_device *pvc)
{
      return pvc->main || pvc->ether;
}


static inline void pvc_carrier(int on, pvc_device *pvc)
{
      if (on) {
            if (pvc->main)
                  if (!netif_carrier_ok(pvc->main))
                        netif_carrier_on(pvc->main);
            if (pvc->ether)
                  if (!netif_carrier_ok(pvc->ether))
                        netif_carrier_on(pvc->ether);
      } else {
            if (pvc->main)
                  if (netif_carrier_ok(pvc->main))
                        netif_carrier_off(pvc->main);
            if (pvc->ether)
                  if (netif_carrier_ok(pvc->ether))
                        netif_carrier_off(pvc->ether);
      }
}


static inline void delete_unused_pvcs(hdlc_device *hdlc)
{
      pvc_device **pvc_p = &state(hdlc)->first_pvc;

      while (*pvc_p) {
            if (!pvc_is_used(*pvc_p)) {
                  pvc_device *pvc = *pvc_p;
#ifdef DEBUG_PVC
                  printk(KERN_DEBUG "freeing unused pvc: %p\n", pvc);
#endif
                  *pvc_p = pvc->next;
                  kfree(pvc);
                  continue;
            }
            pvc_p = &(*pvc_p)->next;
      }
}


static inline struct net_device** get_dev_p(pvc_device *pvc, int type)
{
      if (type == ARPHRD_ETHER)
            return &pvc->ether;
      else
            return &pvc->main;
}


static int fr_hard_header(struct sk_buff **skb_p, u16 dlci)
{
      u16 head_len;
      struct sk_buff *skb = *skb_p;

      switch (skb->protocol) {
      case __constant_htons(NLPID_CCITT_ANSI_LMI):
            head_len = 4;
            skb_push(skb, head_len);
            skb->data[3] = NLPID_CCITT_ANSI_LMI;
            break;

      case __constant_htons(NLPID_CISCO_LMI):
            head_len = 4;
            skb_push(skb, head_len);
            skb->data[3] = NLPID_CISCO_LMI;
            break;

      case __constant_htons(ETH_P_IP):
            head_len = 4;
            skb_push(skb, head_len);
            skb->data[3] = NLPID_IP;
            break;

      case __constant_htons(ETH_P_IPV6):
            head_len = 4;
            skb_push(skb, head_len);
            skb->data[3] = NLPID_IPV6;
            break;

      case __constant_htons(ETH_P_802_3):
            head_len = 10;
            if (skb_headroom(skb) < head_len) {
                  struct sk_buff *skb2 = skb_realloc_headroom(skb,
                                                    head_len);
                  if (!skb2)
                        return -ENOBUFS;
                  dev_kfree_skb(skb);
                  skb = *skb_p = skb2;
            }
            skb_push(skb, head_len);
            skb->data[3] = FR_PAD;
            skb->data[4] = NLPID_SNAP;
            skb->data[5] = FR_PAD;
            skb->data[6] = 0x80;
            skb->data[7] = 0xC2;
            skb->data[8] = 0x00;
            skb->data[9] = 0x07; /* bridged Ethernet frame w/out FCS */
            break;

      default:
            head_len = 10;
            skb_push(skb, head_len);
            skb->data[3] = FR_PAD;
            skb->data[4] = NLPID_SNAP;
            skb->data[5] = FR_PAD;
            skb->data[6] = FR_PAD;
            skb->data[7] = FR_PAD;
            *(__be16*)(skb->data + 8) = skb->protocol;
      }

      dlci_to_q922(skb->data, dlci);
      skb->data[2] = FR_UI;
      return 0;
}



static int pvc_open(struct net_device *dev)
{
      pvc_device *pvc = dev_to_pvc(dev);

      if ((pvc->frad->flags & IFF_UP) == 0)
            return -EIO;  /* Frad must be UP in order to activate PVC */

      if (pvc->open_count++ == 0) {
            hdlc_device *hdlc = dev_to_hdlc(pvc->frad);
            if (state(hdlc)->settings.lmi == LMI_NONE)
                  pvc->state.active = netif_carrier_ok(pvc->frad);

            pvc_carrier(pvc->state.active, pvc);
            state(hdlc)->dce_changed = 1;
      }
      return 0;
}



static int pvc_close(struct net_device *dev)
{
      pvc_device *pvc = dev_to_pvc(dev);

      if (--pvc->open_count == 0) {
            hdlc_device *hdlc = dev_to_hdlc(pvc->frad);
            if (state(hdlc)->settings.lmi == LMI_NONE)
                  pvc->state.active = 0;

            if (state(hdlc)->settings.dce) {
                  state(hdlc)->dce_changed = 1;
                  pvc->state.active = 0;
            }
      }
      return 0;
}



static int pvc_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
{
      pvc_device *pvc = dev_to_pvc(dev);
      fr_proto_pvc_info info;

      if (ifr->ifr_settings.type == IF_GET_PROTO) {
            if (dev->type == ARPHRD_ETHER)
                  ifr->ifr_settings.type = IF_PROTO_FR_ETH_PVC;
            else
                  ifr->ifr_settings.type = IF_PROTO_FR_PVC;

            if (ifr->ifr_settings.size < sizeof(info)) {
                  /* data size wanted */
                  ifr->ifr_settings.size = sizeof(info);
                  return -ENOBUFS;
            }

            info.dlci = pvc->dlci;
            memcpy(info.master, pvc->frad->name, IFNAMSIZ);
            if (copy_to_user(ifr->ifr_settings.ifs_ifsu.fr_pvc_info,
                         &info, sizeof(info)))
                  return -EFAULT;
            return 0;
      }

      return -EINVAL;
}


static inline struct net_device_stats *pvc_get_stats(struct net_device *dev)
{
      return &dev_to_desc(dev)->stats;
}



static int pvc_xmit(struct sk_buff *skb, struct net_device *dev)
{
      pvc_device *pvc = dev_to_pvc(dev);
      struct net_device_stats *stats = pvc_get_stats(dev);

      if (pvc->state.active) {
            if (dev->type == ARPHRD_ETHER) {
                  int pad = ETH_ZLEN - skb->len;
                  if (pad > 0) { /* Pad the frame with zeros */
                        int len = skb->len;
                        if (skb_tailroom(skb) < pad)
                              if (pskb_expand_head(skb, 0, pad,
                                               GFP_ATOMIC)) {
                                    stats->tx_dropped++;
                                    dev_kfree_skb(skb);
                                    return 0;
                              }
                        skb_put(skb, pad);
                        memset(skb->data + len, 0, pad);
                  }
                  skb->protocol = __constant_htons(ETH_P_802_3);
            }
            if (!fr_hard_header(&skb, pvc->dlci)) {
                  stats->tx_bytes += skb->len;
                  stats->tx_packets++;
                  if (pvc->state.fecn) /* TX Congestion counter */
                        stats->tx_compressed++;
                  skb->dev = pvc->frad;
                  dev_queue_xmit(skb);
                  return 0;
            }
      }

      stats->tx_dropped++;
      dev_kfree_skb(skb);
      return 0;
}



static int pvc_change_mtu(struct net_device *dev, int new_mtu)
{
      if ((new_mtu < 68) || (new_mtu > HDLC_MAX_MTU))
            return -EINVAL;
      dev->mtu = new_mtu;
      return 0;
}



static inline void fr_log_dlci_active(pvc_device *pvc)
{
      printk(KERN_INFO "%s: DLCI %d [%s%s%s]%s %s\n",
             pvc->frad->name,
             pvc->dlci,
             pvc->main ? pvc->main->name : "",
             pvc->main && pvc->ether ? " " : "",
             pvc->ether ? pvc->ether->name : "",
             pvc->state.new ? " new" : "",
             !pvc->state.exist ? "deleted" :
             pvc->state.active ? "active" : "inactive");
}



static inline u8 fr_lmi_nextseq(u8 x)
{
      x++;
      return x ? x : 1;
}


static void fr_lmi_send(struct net_device *dev, int fullrep)
{
      hdlc_device *hdlc = dev_to_hdlc(dev);
      struct sk_buff *skb;
      pvc_device *pvc = state(hdlc)->first_pvc;
      int lmi = state(hdlc)->settings.lmi;
      int dce = state(hdlc)->settings.dce;
      int len = lmi == LMI_ANSI ? LMI_ANSI_LENGTH : LMI_CCITT_CISCO_LENGTH;
      int stat_len = (lmi == LMI_CISCO) ? 6 : 3;
      u8 *data;
      int i = 0;

      if (dce && fullrep) {
            len += state(hdlc)->dce_pvc_count * (2 + stat_len);
            if (len > HDLC_MAX_MRU) {
                  printk(KERN_WARNING "%s: Too many PVCs while sending "
                         "LMI full report\n", dev->name);
                  return;
            }
      }

      skb = dev_alloc_skb(len);
      if (!skb) {
            printk(KERN_WARNING "%s: Memory squeeze on fr_lmi_send()\n",
                   dev->name);
            return;
      }
      memset(skb->data, 0, len);
      skb_reserve(skb, 4);
      if (lmi == LMI_CISCO) {
            skb->protocol = __constant_htons(NLPID_CISCO_LMI);
            fr_hard_header(&skb, LMI_CISCO_DLCI);
      } else {
            skb->protocol = __constant_htons(NLPID_CCITT_ANSI_LMI);
            fr_hard_header(&skb, LMI_CCITT_ANSI_DLCI);
      }
      data = skb_tail_pointer(skb);
      data[i++] = LMI_CALLREF;
      data[i++] = dce ? LMI_STATUS : LMI_STATUS_ENQUIRY;
      if (lmi == LMI_ANSI)
            data[i++] = LMI_ANSI_LOCKSHIFT;
      data[i++] = lmi == LMI_CCITT ? LMI_CCITT_REPTYPE :
            LMI_ANSI_CISCO_REPTYPE;
      data[i++] = LMI_REPT_LEN;
      data[i++] = fullrep ? LMI_FULLREP : LMI_INTEGRITY;
      data[i++] = lmi == LMI_CCITT ? LMI_CCITT_ALIVE : LMI_ANSI_CISCO_ALIVE;
      data[i++] = LMI_INTEG_LEN;
      data[i++] = state(hdlc)->txseq =
            fr_lmi_nextseq(state(hdlc)->txseq);
      data[i++] = state(hdlc)->rxseq;

      if (dce && fullrep) {
            while (pvc) {
                  data[i++] = lmi == LMI_CCITT ? LMI_CCITT_PVCSTAT :
                        LMI_ANSI_CISCO_PVCSTAT;
                  data[i++] = stat_len;

                  /* LMI start/restart */
                  if (state(hdlc)->reliable && !pvc->state.exist) {
                        pvc->state.exist = pvc->state.new = 1;
                        fr_log_dlci_active(pvc);
                  }

                  /* ifconfig PVC up */
                  if (pvc->open_count && !pvc->state.active &&
                      pvc->state.exist && !pvc->state.new) {
                        pvc_carrier(1, pvc);
                        pvc->state.active = 1;
                        fr_log_dlci_active(pvc);
                  }

                  if (lmi == LMI_CISCO) {
                        data[i] = pvc->dlci >> 8;
                        data[i + 1] = pvc->dlci & 0xFF;
                  } else {
                        data[i] = (pvc->dlci >> 4) & 0x3F;
                        data[i + 1] = ((pvc->dlci << 3) & 0x78) | 0x80;
                        data[i + 2] = 0x80;
                  }

                  if (pvc->state.new)
                        data[i + 2] |= 0x08;
                  else if (pvc->state.active)
                        data[i + 2] |= 0x02;

                  i += stat_len;
                  pvc = pvc->next;
            }
      }

      skb_put(skb, i);
      skb->priority = TC_PRIO_CONTROL;
      skb->dev = dev;
      skb_reset_network_header(skb);

      dev_queue_xmit(skb);
}



static void fr_set_link_state(int reliable, struct net_device *dev)
{
      hdlc_device *hdlc = dev_to_hdlc(dev);
      pvc_device *pvc = state(hdlc)->first_pvc;

      state(hdlc)->reliable = reliable;
      if (reliable) {
            netif_dormant_off(dev);
            state(hdlc)->n391cnt = 0; /* Request full status */
            state(hdlc)->dce_changed = 1;

            if (state(hdlc)->settings.lmi == LMI_NONE) {
                  while (pvc) {     /* Activate all PVCs */
                        pvc_carrier(1, pvc);
                        pvc->state.exist = pvc->state.active = 1;
                        pvc->state.new = 0;
                        pvc = pvc->next;
                  }
            }
      } else {
            netif_dormant_on(dev);
            while (pvc) {           /* Deactivate all PVCs */
                  pvc_carrier(0, pvc);
                  pvc->state.exist = pvc->state.active = 0;
                  pvc->state.new = 0;
                  if (!state(hdlc)->settings.dce)
                        pvc->state.bandwidth = 0;
                  pvc = pvc->next;
            }
      }
}


static void fr_timer(unsigned long arg)
{
      struct net_device *dev = (struct net_device *)arg;
      hdlc_device *hdlc = dev_to_hdlc(dev);
      int i, cnt = 0, reliable;
      u32 list;

      if (state(hdlc)->settings.dce) {
            reliable = state(hdlc)->request &&
                  time_before(jiffies, state(hdlc)->last_poll +
                            state(hdlc)->settings.t392 * HZ);
            state(hdlc)->request = 0;
      } else {
            state(hdlc)->last_errors <<= 1; /* Shift the list */
            if (state(hdlc)->request) {
                  if (state(hdlc)->reliable)
                        printk(KERN_INFO "%s: No LMI status reply "
                               "received\n", dev->name);
                  state(hdlc)->last_errors |= 1;
            }

            list = state(hdlc)->last_errors;
            for (i = 0; i < state(hdlc)->settings.n393; i++, list >>= 1)
                  cnt += (list & 1);      /* errors count */

            reliable = (cnt < state(hdlc)->settings.n392);
      }

      if (state(hdlc)->reliable != reliable) {
            printk(KERN_INFO "%s: Link %sreliable\n", dev->name,
                   reliable ? "" : "un");
            fr_set_link_state(reliable, dev);
      }

      if (state(hdlc)->settings.dce)
            state(hdlc)->timer.expires = jiffies +
                  state(hdlc)->settings.t392 * HZ;
      else {
            if (state(hdlc)->n391cnt)
                  state(hdlc)->n391cnt--;

            fr_lmi_send(dev, state(hdlc)->n391cnt == 0);

            state(hdlc)->last_poll = jiffies;
            state(hdlc)->request = 1;
            state(hdlc)->timer.expires = jiffies +
                  state(hdlc)->settings.t391 * HZ;
      }

      state(hdlc)->timer.function = fr_timer;
      state(hdlc)->timer.data = arg;
      add_timer(&state(hdlc)->timer);
}


static int fr_lmi_recv(struct net_device *dev, struct sk_buff *skb)
{
      hdlc_device *hdlc = dev_to_hdlc(dev);
      pvc_device *pvc;
      u8 rxseq, txseq;
      int lmi = state(hdlc)->settings.lmi;
      int dce = state(hdlc)->settings.dce;
      int stat_len = (lmi == LMI_CISCO) ? 6 : 3, reptype, error, no_ram, i;

      if (skb->len < (lmi == LMI_ANSI ? LMI_ANSI_LENGTH :
                  LMI_CCITT_CISCO_LENGTH)) {
            printk(KERN_INFO "%s: Short LMI frame\n", dev->name);
            return 1;
      }

      if (skb->data[3] != (lmi == LMI_CISCO ? NLPID_CISCO_LMI :
                       NLPID_CCITT_ANSI_LMI)) {
            printk(KERN_INFO "%s: Received non-LMI frame with LMI DLCI\n",
                   dev->name);
            return 1;
      }

      if (skb->data[4] != LMI_CALLREF) {
            printk(KERN_INFO "%s: Invalid LMI Call reference (0x%02X)\n",
                   dev->name, skb->data[4]);
            return 1;
      }

      if (skb->data[5] != (dce ? LMI_STATUS_ENQUIRY : LMI_STATUS)) {
            printk(KERN_INFO "%s: Invalid LMI Message type (0x%02X)\n",
                   dev->name, skb->data[5]);
            return 1;
      }

      if (lmi == LMI_ANSI) {
            if (skb->data[6] != LMI_ANSI_LOCKSHIFT) {
                  printk(KERN_INFO "%s: Not ANSI locking shift in LMI"
                         " message (0x%02X)\n", dev->name, skb->data[6]);
                  return 1;
            }
            i = 7;
      } else
            i = 6;

      if (skb->data[i] != (lmi == LMI_CCITT ? LMI_CCITT_REPTYPE :
                       LMI_ANSI_CISCO_REPTYPE)) {
            printk(KERN_INFO "%s: Not an LMI Report type IE (0x%02X)\n",
                   dev->name, skb->data[i]);
            return 1;
      }

      if (skb->data[++i] != LMI_REPT_LEN) {
            printk(KERN_INFO "%s: Invalid LMI Report type IE length"
                   " (%u)\n", dev->name, skb->data[i]);
            return 1;
      }

      reptype = skb->data[++i];
      if (reptype != LMI_INTEGRITY && reptype != LMI_FULLREP) {
            printk(KERN_INFO "%s: Unsupported LMI Report type (0x%02X)\n",
                   dev->name, reptype);
            return 1;
      }

      if (skb->data[++i] != (lmi == LMI_CCITT ? LMI_CCITT_ALIVE :
                         LMI_ANSI_CISCO_ALIVE)) {
            printk(KERN_INFO "%s: Not an LMI Link integrity verification"
                   " IE (0x%02X)\n", dev->name, skb->data[i]);
            return 1;
      }

      if (skb->data[++i] != LMI_INTEG_LEN) {
            printk(KERN_INFO "%s: Invalid LMI Link integrity verification"
                   " IE length (%u)\n", dev->name, skb->data[i]);
            return 1;
      }
      i++;

      state(hdlc)->rxseq = skb->data[i++]; /* TX sequence from peer */
      rxseq = skb->data[i++]; /* Should confirm our sequence */

      txseq = state(hdlc)->txseq;

      if (dce)
            state(hdlc)->last_poll = jiffies;

      error = 0;
      if (!state(hdlc)->reliable)
            error = 1;

      if (rxseq == 0 || rxseq != txseq) { /* Ask for full report next time */
            state(hdlc)->n391cnt = 0;
            error = 1;
      }

      if (dce) {
            if (state(hdlc)->fullrep_sent && !error) {
/* Stop sending full report - the last one has been confirmed by DTE */
                  state(hdlc)->fullrep_sent = 0;
                  pvc = state(hdlc)->first_pvc;
                  while (pvc) {
                        if (pvc->state.new) {
                              pvc->state.new = 0;

/* Tell DTE that new PVC is now active */
                              state(hdlc)->dce_changed = 1;
                        }
                        pvc = pvc->next;
                  }
            }

            if (state(hdlc)->dce_changed) {
                  reptype = LMI_FULLREP;
                  state(hdlc)->fullrep_sent = 1;
                  state(hdlc)->dce_changed = 0;
            }

            state(hdlc)->request = 1; /* got request */
            fr_lmi_send(dev, reptype == LMI_FULLREP ? 1 : 0);
            return 0;
      }

      /* DTE */

      state(hdlc)->request = 0; /* got response, no request pending */

      if (error)
            return 0;

      if (reptype != LMI_FULLREP)
            return 0;

      pvc = state(hdlc)->first_pvc;

      while (pvc) {
            pvc->state.deleted = 1;
            pvc = pvc->next;
      }

      no_ram = 0;
      while (skb->len >= i + 2 + stat_len) {
            u16 dlci;
            u32 bw;
            unsigned int active, new;

            if (skb->data[i] != (lmi == LMI_CCITT ? LMI_CCITT_PVCSTAT :
                               LMI_ANSI_CISCO_PVCSTAT)) {
                  printk(KERN_INFO "%s: Not an LMI PVC status IE"
                         " (0x%02X)\n", dev->name, skb->data[i]);
                  return 1;
            }

            if (skb->data[++i] != stat_len) {
                  printk(KERN_INFO "%s: Invalid LMI PVC status IE length"
                         " (%u)\n", dev->name, skb->data[i]);
                  return 1;
            }
            i++;

            new = !! (skb->data[i + 2] & 0x08);
            active = !! (skb->data[i + 2] & 0x02);
            if (lmi == LMI_CISCO) {
                  dlci = (skb->data[i] << 8) | skb->data[i + 1];
                  bw = (skb->data[i + 3] << 16) |
                        (skb->data[i + 4] << 8) |
                        (skb->data[i + 5]);
            } else {
                  dlci = ((skb->data[i] & 0x3F) << 4) |
                        ((skb->data[i + 1] & 0x78) >> 3);
                  bw = 0;
            }

            pvc = add_pvc(dev, dlci);

            if (!pvc && !no_ram) {
                  printk(KERN_WARNING
                         "%s: Memory squeeze on fr_lmi_recv()\n",
                         dev->name);
                  no_ram = 1;
            }

            if (pvc) {
                  pvc->state.exist = 1;
                  pvc->state.deleted = 0;
                  if (active != pvc->state.active ||
                      new != pvc->state.new ||
                      bw != pvc->state.bandwidth ||
                      !pvc->state.exist) {
                        pvc->state.new = new;
                        pvc->state.active = active;
                        pvc->state.bandwidth = bw;
                        pvc_carrier(active, pvc);
                        fr_log_dlci_active(pvc);
                  }
            }

            i += stat_len;
      }

      pvc = state(hdlc)->first_pvc;

      while (pvc) {
            if (pvc->state.deleted && pvc->state.exist) {
                  pvc_carrier(0, pvc);
                  pvc->state.active = pvc->state.new = 0;
                  pvc->state.exist = 0;
                  pvc->state.bandwidth = 0;
                  fr_log_dlci_active(pvc);
            }
            pvc = pvc->next;
      }

      /* Next full report after N391 polls */
      state(hdlc)->n391cnt = state(hdlc)->settings.n391;

      return 0;
}


static int fr_rx(struct sk_buff *skb)
{
      struct net_device *frad = skb->dev;
      hdlc_device *hdlc = dev_to_hdlc(frad);
      fr_hdr *fh = (fr_hdr*)skb->data;
      u8 *data = skb->data;
      u16 dlci;
      pvc_device *pvc;
      struct net_device *dev = NULL;

      if (skb->len <= 4 || fh->ea1 || data[2] != FR_UI)
            goto rx_error;

      dlci = q922_to_dlci(skb->data);

      if ((dlci == LMI_CCITT_ANSI_DLCI &&
           (state(hdlc)->settings.lmi == LMI_ANSI ||
            state(hdlc)->settings.lmi == LMI_CCITT)) ||
          (dlci == LMI_CISCO_DLCI &&
           state(hdlc)->settings.lmi == LMI_CISCO)) {
            if (fr_lmi_recv(frad, skb))
                  goto rx_error;
            dev_kfree_skb_any(skb);
            return NET_RX_SUCCESS;
      }

      pvc = find_pvc(hdlc, dlci);
      if (!pvc) {
#ifdef DEBUG_PKT
            printk(KERN_INFO "%s: No PVC for received frame's DLCI %d\n",
                   frad->name, dlci);
#endif
            dev_kfree_skb_any(skb);
            return NET_RX_DROP;
      }

      if (pvc->state.fecn != fh->fecn) {
#ifdef DEBUG_ECN
            printk(KERN_DEBUG "%s: DLCI %d FECN O%s\n", frad->name,
                   dlci, fh->fecn ? "N" : "FF");
#endif
            pvc->state.fecn ^= 1;
      }

      if (pvc->state.becn != fh->becn) {
#ifdef DEBUG_ECN
            printk(KERN_DEBUG "%s: DLCI %d BECN O%s\n", frad->name,
                   dlci, fh->becn ? "N" : "FF");
#endif
            pvc->state.becn ^= 1;
      }


      if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) {
            dev_to_desc(frad)->stats.rx_dropped++;
            return NET_RX_DROP;
      }

      if (data[3] == NLPID_IP) {
            skb_pull(skb, 4); /* Remove 4-byte header (hdr, UI, NLPID) */
            dev = pvc->main;
            skb->protocol = htons(ETH_P_IP);

      } else if (data[3] == NLPID_IPV6) {
            skb_pull(skb, 4); /* Remove 4-byte header (hdr, UI, NLPID) */
            dev = pvc->main;
            skb->protocol = htons(ETH_P_IPV6);

      } else if (skb->len > 10 && data[3] == FR_PAD &&
               data[4] == NLPID_SNAP && data[5] == FR_PAD) {
            u16 oui = ntohs(*(__be16*)(data + 6));
            u16 pid = ntohs(*(__be16*)(data + 8));
            skb_pull(skb, 10);

            switch ((((u32)oui) << 16) | pid) {
            case ETH_P_ARP: /* routed frame with SNAP */
            case ETH_P_IPX:
            case ETH_P_IP:    /* a long variant */
            case ETH_P_IPV6:
                  dev = pvc->main;
                  skb->protocol = htons(pid);
                  break;

            case 0x80C20007: /* bridged Ethernet frame */
                  if ((dev = pvc->ether) != NULL)
                        skb->protocol = eth_type_trans(skb, dev);
                  break;

            default:
                  printk(KERN_INFO "%s: Unsupported protocol, OUI=%x "
                         "PID=%x\n", frad->name, oui, pid);
                  dev_kfree_skb_any(skb);
                  return NET_RX_DROP;
            }
      } else {
            printk(KERN_INFO "%s: Unsupported protocol, NLPID=%x "
                   "length = %i\n", frad->name, data[3], skb->len);
            dev_kfree_skb_any(skb);
            return NET_RX_DROP;
      }

      if (dev) {
            struct net_device_stats *stats = pvc_get_stats(dev);
            stats->rx_packets++; /* PVC traffic */
            stats->rx_bytes += skb->len;
            if (pvc->state.becn)
                  stats->rx_compressed++;
            netif_rx(skb);
            return NET_RX_SUCCESS;
      } else {
            dev_kfree_skb_any(skb);
            return NET_RX_DROP;
      }

 rx_error:
      dev_to_desc(frad)->stats.rx_errors++; /* Mark error */
      dev_kfree_skb_any(skb);
      return NET_RX_DROP;
}



static void fr_start(struct net_device *dev)
{
      hdlc_device *hdlc = dev_to_hdlc(dev);
#ifdef DEBUG_LINK
      printk(KERN_DEBUG "fr_start\n");
#endif
      if (state(hdlc)->settings.lmi != LMI_NONE) {
            state(hdlc)->reliable = 0;
            state(hdlc)->dce_changed = 1;
            state(hdlc)->request = 0;
            state(hdlc)->fullrep_sent = 0;
            state(hdlc)->last_errors = 0xFFFFFFFF;
            state(hdlc)->n391cnt = 0;
            state(hdlc)->txseq = state(hdlc)->rxseq = 0;

            init_timer(&state(hdlc)->timer);
            /* First poll after 1 s */
            state(hdlc)->timer.expires = jiffies + HZ;
            state(hdlc)->timer.function = fr_timer;
            state(hdlc)->timer.data = (unsigned long)dev;
            add_timer(&state(hdlc)->timer);
      } else
            fr_set_link_state(1, dev);
}


static void fr_stop(struct net_device *dev)
{
      hdlc_device *hdlc = dev_to_hdlc(dev);
#ifdef DEBUG_LINK
      printk(KERN_DEBUG "fr_stop\n");
#endif
      if (state(hdlc)->settings.lmi != LMI_NONE)
            del_timer_sync(&state(hdlc)->timer);
      fr_set_link_state(0, dev);
}


static void fr_close(struct net_device *dev)
{
      hdlc_device *hdlc = dev_to_hdlc(dev);
      pvc_device *pvc = state(hdlc)->first_pvc;

      while (pvc) {           /* Shutdown all PVCs for this FRAD */
            if (pvc->main)
                  dev_close(pvc->main);
            if (pvc->ether)
                  dev_close(pvc->ether);
            pvc = pvc->next;
      }
}


static void pvc_setup(struct net_device *dev)
{
      dev->type = ARPHRD_DLCI;
      dev->flags = IFF_POINTOPOINT;
      dev->hard_header_len = 10;
      dev->addr_len = 2;
}

static int fr_add_pvc(struct net_device *frad, unsigned int dlci, int type)
{
      hdlc_device *hdlc = dev_to_hdlc(frad);
      pvc_device *pvc = NULL;
      struct net_device *dev;
      int result, used;
      char * prefix = "pvc%d";

      if (type == ARPHRD_ETHER)
            prefix = "pvceth%d";

      if ((pvc = add_pvc(frad, dlci)) == NULL) {
            printk(KERN_WARNING "%s: Memory squeeze on fr_add_pvc()\n",
                   frad->name);
            return -ENOBUFS;
      }

      if (*get_dev_p(pvc, type))
            return -EEXIST;

      used = pvc_is_used(pvc);

      if (type == ARPHRD_ETHER)
            dev = alloc_netdev(sizeof(struct net_device_stats),
                           "pvceth%d", ether_setup);
      else
            dev = alloc_netdev(sizeof(struct net_device_stats),
                           "pvc%d", pvc_setup);

      if (!dev) {
            printk(KERN_WARNING "%s: Memory squeeze on fr_pvc()\n",
                   frad->name);
            delete_unused_pvcs(hdlc);
            return -ENOBUFS;
      }

      if (type == ARPHRD_ETHER) {
            memcpy(dev->dev_addr, "\x00\x01", 2);
                get_random_bytes(dev->dev_addr + 2, ETH_ALEN - 2);
      } else {
            *(__be16*)dev->dev_addr = htons(dlci);
            dlci_to_q922(dev->broadcast, dlci);
      }
      dev->hard_start_xmit = pvc_xmit;
      dev->get_stats = pvc_get_stats;
      dev->open = pvc_open;
      dev->stop = pvc_close;
      dev->do_ioctl = pvc_ioctl;
      dev->change_mtu = pvc_change_mtu;
      dev->mtu = HDLC_MAX_MTU;
      dev->tx_queue_len = 0;
      dev->priv = pvc;

      result = dev_alloc_name(dev, dev->name);
      if (result < 0) {
            free_netdev(dev);
            delete_unused_pvcs(hdlc);
            return result;
      }

      if (register_netdevice(dev) != 0) {
            free_netdev(dev);
            delete_unused_pvcs(hdlc);
            return -EIO;
      }

      dev->destructor = free_netdev;
      *get_dev_p(pvc, type) = dev;
      if (!used) {
            state(hdlc)->dce_changed = 1;
            state(hdlc)->dce_pvc_count++;
      }
      return 0;
}



static int fr_del_pvc(hdlc_device *hdlc, unsigned int dlci, int type)
{
      pvc_device *pvc;
      struct net_device *dev;

      if ((pvc = find_pvc(hdlc, dlci)) == NULL)
            return -ENOENT;

      if ((dev = *get_dev_p(pvc, type)) == NULL)
            return -ENOENT;

      if (dev->flags & IFF_UP)
            return -EBUSY;          /* PVC in use */

      unregister_netdevice(dev); /* the destructor will free_netdev(dev) */
      *get_dev_p(pvc, type) = NULL;

      if (!pvc_is_used(pvc)) {
            state(hdlc)->dce_pvc_count--;
            state(hdlc)->dce_changed = 1;
      }
      delete_unused_pvcs(hdlc);
      return 0;
}



static void fr_destroy(struct net_device *frad)
{
      hdlc_device *hdlc = dev_to_hdlc(frad);
      pvc_device *pvc = state(hdlc)->first_pvc;
      state(hdlc)->first_pvc = NULL; /* All PVCs destroyed */
      state(hdlc)->dce_pvc_count = 0;
      state(hdlc)->dce_changed = 1;

      while (pvc) {
            pvc_device *next = pvc->next;
            /* destructors will free_netdev() main and ether */
            if (pvc->main)
                  unregister_netdevice(pvc->main);

            if (pvc->ether)
                  unregister_netdevice(pvc->ether);

            kfree(pvc);
            pvc = next;
      }
}


static struct hdlc_proto proto = {
      .close            = fr_close,
      .start            = fr_start,
      .stop       = fr_stop,
      .detach           = fr_destroy,
      .ioctl            = fr_ioctl,
      .module           = THIS_MODULE,
};


static int fr_ioctl(struct net_device *dev, struct ifreq *ifr)
{
      fr_proto __user *fr_s = ifr->ifr_settings.ifs_ifsu.fr;
      const size_t size = sizeof(fr_proto);
      fr_proto new_settings;
      hdlc_device *hdlc = dev_to_hdlc(dev);
      fr_proto_pvc pvc;
      int result;

      switch (ifr->ifr_settings.type) {
      case IF_GET_PROTO:
            if (dev_to_hdlc(dev)->proto != &proto) /* Different proto */
                  return -EINVAL;
            ifr->ifr_settings.type = IF_PROTO_FR;
            if (ifr->ifr_settings.size < size) {
                  ifr->ifr_settings.size = size; /* data size wanted */
                  return -ENOBUFS;
            }
            if (copy_to_user(fr_s, &state(hdlc)->settings, size))
                  return -EFAULT;
            return 0;

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

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

            if (copy_from_user(&new_settings, fr_s, size))
                  return -EFAULT;

            if (new_settings.lmi == LMI_DEFAULT)
                  new_settings.lmi = LMI_ANSI;

            if ((new_settings.lmi != LMI_NONE &&
                 new_settings.lmi != LMI_ANSI &&
                 new_settings.lmi != LMI_CCITT &&
                 new_settings.lmi != LMI_CISCO) ||
                new_settings.t391 < 1 ||
                new_settings.t392 < 2 ||
                new_settings.n391 < 1 ||
                new_settings.n392 < 1 ||
                new_settings.n393 < new_settings.n392 ||
                new_settings.n393 > 32 ||
                (new_settings.dce != 0 &&
                 new_settings.dce != 1))
                  return -EINVAL;

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

            if (dev_to_hdlc(dev)->proto != &proto) { /* Different proto */
                  result = attach_hdlc_protocol(dev, &proto, fr_rx,
                                          sizeof(struct frad_state));
                  if (result)
                        return result;
                  state(hdlc)->first_pvc = NULL;
                  state(hdlc)->dce_pvc_count = 0;
            }
            memcpy(&state(hdlc)->settings, &new_settings, size);

            dev->hard_start_xmit = hdlc->xmit;
            dev->type = ARPHRD_FRAD;
            return 0;

      case IF_PROTO_FR_ADD_PVC:
      case IF_PROTO_FR_DEL_PVC:
      case IF_PROTO_FR_ADD_ETH_PVC:
      case IF_PROTO_FR_DEL_ETH_PVC:
            if (dev_to_hdlc(dev)->proto != &proto) /* Different proto */
                  return -EINVAL;

            if(!capable(CAP_NET_ADMIN))
                  return -EPERM;

            if (copy_from_user(&pvc, ifr->ifr_settings.ifs_ifsu.fr_pvc,
                           sizeof(fr_proto_pvc)))
                  return -EFAULT;

            if (pvc.dlci <= 0 || pvc.dlci >= 1024)
                  return -EINVAL;   /* Only 10 bits, DLCI 0 reserved */

            if (ifr->ifr_settings.type == IF_PROTO_FR_ADD_ETH_PVC ||
                ifr->ifr_settings.type == IF_PROTO_FR_DEL_ETH_PVC)
                  result = ARPHRD_ETHER; /* bridged Ethernet device */
            else
                  result = ARPHRD_DLCI;

            if (ifr->ifr_settings.type == IF_PROTO_FR_ADD_PVC ||
                ifr->ifr_settings.type == IF_PROTO_FR_ADD_ETH_PVC)
                  return fr_add_pvc(dev, pvc.dlci, result);
            else
                  return fr_del_pvc(hdlc, pvc.dlci, result);
      }

      return -EINVAL;
}


static int __init mod_init(void)
{
      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("Frame-Relay protocol support for generic HDLC");
MODULE_LICENSE("GPL v2");

Generated by  Doxygen 1.6.0   Back to index