[PATCH] Generic HDLC update

The attached patch updates generic HDLC to version 1.18.
FR Cisco LMI production-tested. Please apply to Linux 2.6. Thanks.

Changes:
- doc updates
- added Cisco LMI support to Frame-Relay code
- cleaned hdlc_fr.c a bit, removed some orphaned #defines etc.
- fixed a problem with non-functional LMI in FR DCE mode.
- changed diagnostic messages to better conform to FR standards
- all protocols: information about carrier changes (DCD line) is now
  printed to kernel logs.

Signed-Off-By: Krzysztof Halasa <khc@pm.waw.pl>

2 files changed, 187 insertions, 149 deletions

diff --git a/drivers/net/wan/hdlc_fr.c b/drivers/net/wan/hdlc_fr.c
index 7f450b51a6cb..a5d6891c9d4c 100644
--- a/drivers/net/wan/hdlc_fr.c
+++ b/drivers/net/wan/hdlc_fr.c
@@ -2,7 +2,7 @@
  * Generic HDLC support routines for Linux
  * Frame Relay support
  *
- * Copyright (C) 1999 - 2003 Krzysztof Halasa <khc@pm.waw.pl>
+ * Copyright (C) 1999 - 2005 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
@@ -27,6 +27,10 @@
  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>
@@ -49,45 +53,41 @@
 #undef DEBUG_ECN
 #undef DEBUG_LINK
 
-#define MAXLEN_LMISTAT  20      /* max size of status enquiry frame */
-
-#define PVC_STATE_NEW    0x01
-#define PVC_STATE_ACTIVE 0x02
-#define PVC_STATE_FECN   0x08 /* FECN condition */
-#define PVC_STATE_BECN   0x10 /* BECN condition */
-
-
-#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_Q933       0x08
-
-
-#define LMI_DLCI                   0 /* LMI DLCI */
-#define LMI_PROTO               0x08
-#define LMI_CALLREF             0x00 /* Call Reference */
-#define LMI_ANSI_LOCKSHIFT      0x95 /* ANSI lockshift */
-#define LMI_REPTYPE                1 /* report type */
-#define LMI_CCITT_REPTYPE       0x51
-#define LMI_ALIVE                  3 /* keep alive */
-#define LMI_CCITT_ALIVE         0x53
-#define LMI_PVCSTAT                7 /* pvc status */
-#define LMI_CCITT_PVCSTAT       0x57
-#define LMI_FULLREP                0 /* full report  */
-#define LMI_INTEGRITY              1 /* link integrity report */
-#define LMI_SINGLE                 2 /* single pvc report */
+#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_LENGTH                13 /* standard LMI frame length */
-#define LMI_ANSI_LENGTH           14
+#define LMI_CCITT_CISCO_LENGTH    13 /* LMI frame lengths */
+#define LMI_ANSI_LENGTH           14
 
 
 typedef struct {
@@ -223,51 +223,34 @@ static inline struct net_device** get_dev_p(pvc_device *pvc, int type)
 }
 
 
-static inline u16 status_to_dlci(u8 *status, int *active, int *new)
-{
-        *new = (status[2] & 0x08) ? 1 : 0;
-        *active = (status[2] & 0x02) ? 1 : 0;
-
-        return ((status[0] & 0x3F) << 4) | ((status[1] & 0x78) >> 3);
-}
-
-
-static inline void dlci_to_status(u16 dlci, u8 *status, int active, int new)
-{
-        status[0] = (dlci >> 4) & 0x3F;
-        status[1] = ((dlci << 3) & 0x78) | 0x80;
-        status[2] = 0x80;
-
-        if (new)
-                status[2] |= 0x08;
-        else if (active)
-                status[2] |= 0x02;
-}
-
-
-
 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_ntohs(ETH_P_IP):
+        case __constant_ntohs(NLPID_CCITT_ANSI_LMI):
                 head_len = 4;
                 skb_push(skb, head_len);
-                skb->data[3] = NLPID_IP;
+                skb->data[3] = NLPID_CCITT_ANSI_LMI;
                 break;
 
-        case __constant_ntohs(ETH_P_IPV6):
+        case __constant_ntohs(NLPID_CISCO_LMI):
                 head_len = 4;
                 skb_push(skb, head_len);
-                skb->data[3] = NLPID_IPV6;
+                skb->data[3] = NLPID_CISCO_LMI;
                 break;
 
-        case __constant_ntohs(LMI_PROTO):
+        case __constant_ntohs(ETH_P_IP):
+                head_len = 4;
+                skb_push(skb, head_len);
+                skb->data[3] = NLPID_IP;
+                break;
+
+        case __constant_ntohs(ETH_P_IPV6):
                 head_len = 4;
                 skb_push(skb, head_len);
-                skb->data[3] = LMI_PROTO;
+                skb->data[3] = NLPID_IPV6;
                 break;
 
         case __constant_ntohs(ETH_P_802_3):
@@ -461,13 +444,14 @@ 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 = hdlc->state.fr.first_pvc;
-        int len = (hdlc->state.fr.settings.lmi == LMI_ANSI) ? LMI_ANSI_LENGTH
-                : LMI_LENGTH;
-        int stat_len = 3;
+        int lmi = hdlc->state.fr.settings.lmi;
+        int dce = hdlc->state.fr.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 (hdlc->state.fr.settings.dce && fullrep) {
+        if (dce && fullrep) {
                 len += hdlc->state.fr.dce_pvc_count * (2 + stat_len);
                 if (len > HDLC_MAX_MRU) {
                         printk(KERN_WARNING "%s: Too many PVCs while sending "
@@ -484,29 +468,31 @@ static void fr_lmi_send(struct net_device *dev, int fullrep)
         }
         memset(skb->data, 0, len);
         skb_reserve(skb, 4);
-        skb->protocol = __constant_htons(LMI_PROTO);
-        fr_hard_header(&skb, LMI_DLCI);
+        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;
         data[i++] = LMI_CALLREF;
-        data[i++] = hdlc->state.fr.settings.dce
-                ? LMI_STATUS : LMI_STATUS_ENQUIRY;
-        if (hdlc->state.fr.settings.lmi == LMI_ANSI)
+        data[i++] = dce ? LMI_STATUS : LMI_STATUS_ENQUIRY;
+        if (lmi == LMI_ANSI)
                 data[i++] = LMI_ANSI_LOCKSHIFT;
-        data[i++] = (hdlc->state.fr.settings.lmi == LMI_CCITT)
-                ? LMI_CCITT_REPTYPE : LMI_REPTYPE;
+        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++] = (hdlc->state.fr.settings.lmi == LMI_CCITT)
-                ? LMI_CCITT_ALIVE : LMI_ALIVE;
+        data[i++] = lmi == LMI_CCITT ? LMI_CCITT_ALIVE : LMI_ANSI_CISCO_ALIVE;
         data[i++] = LMI_INTEG_LEN;
         data[i++] = hdlc->state.fr.txseq =fr_lmi_nextseq(hdlc->state.fr.txseq);
         data[i++] = hdlc->state.fr.rxseq;
 
-        if (hdlc->state.fr.settings.dce && fullrep) {
+        if (dce && fullrep) {
                 while (pvc) {
-                        data[i++] = (hdlc->state.fr.settings.lmi == LMI_CCITT)
-                                ? LMI_CCITT_PVCSTAT : LMI_PVCSTAT;
+                        data[i++] = lmi == LMI_CCITT ? LMI_CCITT_PVCSTAT :
+                                LMI_ANSI_CISCO_PVCSTAT;
                         data[i++] = stat_len;
 
                         /* LMI start/restart */
@@ -523,8 +509,20 @@ static void fr_lmi_send(struct net_device *dev, int fullrep)
                                 fr_log_dlci_active(pvc);
                         }
 
-                        dlci_to_status(pvc->dlci, data + i,
-                                       pvc->state.active, pvc->state.new);
+                        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;
                 }
@@ -569,6 +567,8 @@ static void fr_set_link_state(int reliable, struct net_device *dev)
                         pvc_carrier(0, pvc);
                         pvc->state.exist = pvc->state.active = 0;
                         pvc->state.new = 0;
+                        if (!hdlc->state.fr.settings.dce)
+                                pvc->state.bandwidth = 0;
                         pvc = pvc->next;
                 }
         }
@@ -583,11 +583,12 @@ static void fr_timer(unsigned long arg)
         int i, cnt = 0, reliable;
         u32 list;
 
-        if (hdlc->state.fr.settings.dce)
+        if (hdlc->state.fr.settings.dce) {
                 reliable = hdlc->state.fr.request &&
                         time_before(jiffies, hdlc->state.fr.last_poll +
                                     hdlc->state.fr.settings.t392 * HZ);
-        else {
+                hdlc->state.fr.request = 0;
+        } else {
                 hdlc->state.fr.last_errors <<= 1; /* Shift the list */
                 if (hdlc->state.fr.request) {
                         if (hdlc->state.fr.reliable)
@@ -634,65 +635,88 @@ static void fr_timer(unsigned long arg)
 static int fr_lmi_recv(struct net_device *dev, struct sk_buff *skb)
 {
         hdlc_device *hdlc = dev_to_hdlc(dev);
-        int stat_len;
         pvc_device *pvc;
-        int reptype = -1, error, no_ram;
         u8 rxseq, txseq;
-        int i;
+        int lmi = hdlc->state.fr.settings.lmi;
+        int dce = hdlc->state.fr.settings.dce;
+        int stat_len = (lmi == LMI_CISCO) ? 6 : 3, reptype, error, no_ram, i;
 
-        if (skb->len < ((hdlc->state.fr.settings.lmi == LMI_ANSI)
-                        ? LMI_ANSI_LENGTH : LMI_LENGTH)) {
+        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[5] != (!hdlc->state.fr.settings.dce ?
-                             LMI_STATUS : LMI_STATUS_ENQUIRY)) {
-                printk(KERN_INFO "%s: LMI msgtype=%x, Not LMI status %s\n",
-                       dev->name, skb->data[2],
-                       hdlc->state.fr.settings.dce ? "enquiry" : "reply");
+        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;
         }
 
-        i = (hdlc->state.fr.settings.lmi == LMI_ANSI) ? 7 : 6;
+        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] !=
-            ((hdlc->state.fr.settings.lmi == LMI_CCITT)
-             ? LMI_CCITT_REPTYPE : LMI_REPTYPE)) {
-                printk(KERN_INFO "%s: Not a report type=%x\n",
+        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;
         }
-        i++;
 
-        i++;                            /* Skip length field */
+        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++];
+        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]!=
-            ((hdlc->state.fr.settings.lmi == LMI_CCITT)
-             ? LMI_CCITT_ALIVE : LMI_ALIVE)) {
-                printk(KERN_INFO "%s: Unsupported status element=%x\n",
-                       dev->name, skb->data[i]);
+        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;
         }
-        i++;
 
-        i++;                    /* Skip length field */
+        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++;
 
         hdlc->state.fr.rxseq = skb->data[i++]; /* TX sequence from peer */
         rxseq = skb->data[i++]; /* Should confirm our sequence */
 
         txseq = hdlc->state.fr.txseq;
 
-        if (hdlc->state.fr.settings.dce) {
-                if (reptype != LMI_FULLREP && reptype != LMI_INTEGRITY) {
-                        printk(KERN_INFO "%s: Unsupported report type=%x\n",
-                               dev->name, reptype);
-                        return 1;
-                }
+        if (dce)
                 hdlc->state.fr.last_poll = jiffies;
-        }
 
         error = 0;
         if (!hdlc->state.fr.reliable)
@@ -703,7 +727,7 @@ static int fr_lmi_recv(struct net_device *dev, struct sk_buff *skb)
                 error = 1;
         }
 
-        if (hdlc->state.fr.settings.dce) {
+        if (dce) {
                 if (hdlc->state.fr.fullrep_sent && !error) {
 /* Stop sending full report - the last one has been confirmed by DTE */
                         hdlc->state.fr.fullrep_sent = 0;
@@ -725,6 +749,7 @@ static int fr_lmi_recv(struct net_device *dev, struct sk_buff *skb)
                         hdlc->state.fr.dce_changed = 0;
                 }
 
+                hdlc->state.fr.request = 1; /* got request */
                 fr_lmi_send(dev, reptype == LMI_FULLREP ? 1 : 0);
                 return 0;
         }
@@ -739,7 +764,6 @@ static int fr_lmi_recv(struct net_device *dev, struct sk_buff *skb)
         if (reptype != LMI_FULLREP)
                 return 0;
 
-        stat_len = 3;
         pvc = hdlc->state.fr.first_pvc;
 
         while (pvc) {
@@ -750,24 +774,35 @@ static int fr_lmi_recv(struct net_device *dev, struct sk_buff *skb)
         no_ram = 0;
         while (skb->len >= i + 2 + stat_len) {
                 u16 dlci;
+                u32 bw;
                 unsigned int active, new;
 
-                if (skb->data[i] != ((hdlc->state.fr.settings.lmi == LMI_CCITT)
-                                     ? LMI_CCITT_PVCSTAT : LMI_PVCSTAT)) {
-                        printk(KERN_WARNING "%s: Invalid PVCSTAT ID: %x\n",
-                               dev->name, skb->data[i]);
+                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;
                 }
-                i++;
 
-                if (skb->data[i] != stat_len) {
-                        printk(KERN_WARNING "%s: Invalid PVCSTAT length: %x\n",
-                               dev->name, skb->data[i]);
+                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++;
 
-                dlci = status_to_dlci(skb->data + i, &active, &new);
+                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);
 
@@ -783,9 +818,11 @@ static int fr_lmi_recv(struct net_device *dev, struct sk_buff *skb)
                         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);
                         }
@@ -801,6 +838,7 @@ static int fr_lmi_recv(struct net_device *dev, struct sk_buff *skb)
                         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;
@@ -829,22 +867,15 @@ static int fr_rx(struct sk_buff *skb)
 
         dlci = q922_to_dlci(skb->data);
 
-        if (dlci == LMI_DLCI) {
-                if (hdlc->state.fr.settings.lmi == LMI_NONE)
-                        goto rx_error; /* LMI packet with no LMI? */
-
-                if (data[3] == LMI_PROTO) {
-                        if (fr_lmi_recv(ndev, skb))
-                                goto rx_error;
-                        else {
-                                dev_kfree_skb_any(skb);
-                                return NET_RX_SUCCESS;
-                        }
-                }
-
-                printk(KERN_INFO "%s: Received non-LMI frame with LMI DLCI\n",
-                       ndev->name);
-                goto rx_error;
+        if ((dlci == LMI_CCITT_ANSI_DLCI &&
+             (hdlc->state.fr.settings.lmi == LMI_ANSI ||
+              hdlc->state.fr.settings.lmi == LMI_CCITT)) ||
+            (dlci == LMI_CISCO_DLCI &&
+             hdlc->state.fr.settings.lmi == LMI_CISCO)) {
+                if (fr_lmi_recv(ndev, skb))
+                        goto rx_error;
+                dev_kfree_skb_any(skb);
+                return NET_RX_SUCCESS;
         }
 
         pvc = find_pvc(hdlc, dlci);
@@ -1170,7 +1201,8 @@ int hdlc_fr_ioctl(struct net_device *dev, struct ifreq *ifr)
 
                 if ((new_settings.lmi != LMI_NONE &&
                      new_settings.lmi != LMI_ANSI &&
-                     new_settings.lmi != LMI_CCITT) ||
+                     new_settings.lmi != LMI_CCITT &&
+                     new_settings.lmi != LMI_CISCO) ||
                     new_settings.t391 < 1 ||
                     new_settings.t392 < 2 ||
                     new_settings.n391 < 1 ||
diff --git a/drivers/net/wan/hdlc_generic.c b/drivers/net/wan/hdlc_generic.c
index 6ed064cb4469..a63f6a2cc4f7 100644
--- a/drivers/net/wan/hdlc_generic.c
+++ b/drivers/net/wan/hdlc_generic.c
@@ -1,7 +1,7 @@
 /*
  * Generic HDLC support routines for Linux
  *
- * Copyright (C) 1999 - 2003 Krzysztof Halasa <khc@pm.waw.pl>
+ * Copyright (C) 1999 - 2005 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
@@ -38,7 +38,7 @@
 #include <linux/hdlc.h>
 
 
-static const char* version = "HDLC support module revision 1.17";
+static const char* version = "HDLC support module revision 1.18";
 
 #undef DEBUG_LINK
 
@@ -126,10 +126,13 @@ void hdlc_set_carrier(int on, struct net_device *dev)
         if (!hdlc->open)
                 goto carrier_exit;
 
-        if (hdlc->carrier)
+        if (hdlc->carrier) {
+                printk(KERN_INFO "%s: Carrier detected\n", dev->name);
                 __hdlc_set_carrier_on(dev);
-        else
+        } else {
+                printk(KERN_INFO "%s: Carrier lost\n", dev->name);
                 __hdlc_set_carrier_off(dev);
+        }
 
 carrier_exit:
         spin_unlock_irqrestore(&hdlc->state_lock, flags);
@@ -157,8 +160,11 @@ int hdlc_open(struct net_device *dev)
 
         spin_lock_irq(&hdlc->state_lock);
 
-        if (hdlc->carrier)
+        if (hdlc->carrier) {
+                printk(KERN_INFO "%s: Carrier detected\n", dev->name);
                 __hdlc_set_carrier_on(dev);
+        } else
+                printk(KERN_INFO "%s: No carrier\n", dev->name);
 
         hdlc->open = 1;