Move the new files to the same places as in automake.
[obnox/wireshark/wip.git] / wiretap / k12.c
index 1857a6f09b802baf0bcbd6bb377b3dadc23d2854..cabfd26935bc64569bea9fbfb281a655ac0e59db 100644 (file)
@@ -3,7 +3,7 @@
  *
  *  routines for importing tektronix k12xx *.rf5 files
  *
- *  Copyright (c) 2005, Luis E. Garia Ontanon <luis.ontanon@gmail.com>
+ *  Copyright (c) 2005, Luis E. Garia Ontanon <luis@ontanon.org>
  *
  * $Id$
  *
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  */
 
-/* #define DEBUG_K12 */
 #ifdef HAVE_CONFIG_H
 #include "config.h"
 #endif
 #include <stdlib.h>
 #include <string.h>
 #include <errno.h>
+
 #include "wtap-int.h"
 #include "wtap.h"
 #include "file_wrappers.h"
 #include "buffer.h"
 #include "k12.h"
 
-/*#define DEBUG_K12*/
+#include <wsutil/str_util.h>
+
+/*
+ * See
+ *
+ *  http://www2.tek.com/cmswpt/madownload.lotr?ct=MA&cs=mpm&ci=11284&lc=EN
+ *
+ * for some information about the file format.  You may have to fill in
+ * a form to download the document ("Recored File API Programmer Manual").
+ *
+ * Unfortunately, it describes an API that delivers records from an rf5
+ * file, not the raw format of an rf5 file, so, while it gives the formats
+ * of the records with various types, it does not indicate how those records
+ * are stored in the file.
+ */
+
+/* #define DEBUG_K12 */
 #ifdef DEBUG_K12
 #include <stdio.h>
 #include <ctype.h>
 #include <stdarg.h>
-
+#include <wsutil/file_util.h>
 
 FILE* dbg_out = NULL;
 char* env_file = NULL;
@@ -52,10 +68,10 @@ static unsigned debug_level = 0;
 
 void k12_fprintf(char* fmt, ...) {
     va_list ap;
-    
+
     va_start(ap,fmt);
     vfprintf(dbg_out, fmt, ap);
-    va_end(ap);    
+    va_end(ap);
 }
 
 #define CAT(a,b) a##b
@@ -67,39 +83,39 @@ void k12_fprintf(char* fmt, ...) {
 
 void k12_hexdump(guint level, gint64 offset, char* label, unsigned char* b, unsigned len) {
     static const char* c2t[] = {
-        "00","01","02","03","04","05","06","07","08","09","0a","0b","0c","0d","0e","0f", 
-        "10","11","12","13","14","15","16","17","18","19","1a","1b","1c","1d","1e","1f", 
-        "20","21","22","23","24","25","26","27","28","29","2a","2b","2c","2d","2e","2f", 
-        "30","31","32","33","34","35","36","37","38","39","3a","3b","3c","3d","3e","3f", 
-        "40","41","42","43","44","45","46","47","48","49","4a","4b","4c","4d","4e","4f", 
-        "50","51","52","53","54","55","56","57","58","59","5a","5b","5c","5d","5e","5f", 
-        "60","61","62","63","64","65","66","67","68","69","6a","6b","6c","6d","6e","6f", 
-        "70","71","72","73","74","75","76","77","78","79","7a","7b","7c","7d","7e","7f", 
-        "80","81","82","83","84","85","86","87","88","89","8a","8b","8c","8d","8e","8f", 
-        "90","91","92","93","94","95","96","97","98","99","9a","9b","9c","9d","9e","9f", 
-        "a0","a1","a2","a3","a4","a5","a6","a7","a8","a9","aa","ab","ac","ad","ae","af", 
-        "b0","b1","b2","b3","b4","b5","b6","b7","b8","b9","ba","bb","bc","bd","be","bf", 
-        "c0","c1","c2","c3","c4","c5","c6","c7","c8","c9","ca","cb","cc","cd","ce","cf", 
-        "d0","d1","d2","d3","d4","d5","d6","d7","d8","d9","da","db","dc","dd","de","df", 
-        "e0","e1","e2","e3","e4","e5","e6","e7","e8","e9","ea","eb","ec","ed","ee","ef", 
+        "00","01","02","03","04","05","06","07","08","09","0a","0b","0c","0d","0e","0f",
+        "10","11","12","13","14","15","16","17","18","19","1a","1b","1c","1d","1e","1f",
+        "20","21","22","23","24","25","26","27","28","29","2a","2b","2c","2d","2e","2f",
+        "30","31","32","33","34","35","36","37","38","39","3a","3b","3c","3d","3e","3f",
+        "40","41","42","43","44","45","46","47","48","49","4a","4b","4c","4d","4e","4f",
+        "50","51","52","53","54","55","56","57","58","59","5a","5b","5c","5d","5e","5f",
+        "60","61","62","63","64","65","66","67","68","69","6a","6b","6c","6d","6e","6f",
+        "70","71","72","73","74","75","76","77","78","79","7a","7b","7c","7d","7e","7f",
+        "80","81","82","83","84","85","86","87","88","89","8a","8b","8c","8d","8e","8f",
+        "90","91","92","93","94","95","96","97","98","99","9a","9b","9c","9d","9e","9f",
+        "a0","a1","a2","a3","a4","a5","a6","a7","a8","a9","aa","ab","ac","ad","ae","af",
+        "b0","b1","b2","b3","b4","b5","b6","b7","b8","b9","ba","bb","bc","bd","be","bf",
+        "c0","c1","c2","c3","c4","c5","c6","c7","c8","c9","ca","cb","cc","cd","ce","cf",
+        "d0","d1","d2","d3","d4","d5","d6","d7","d8","d9","da","db","dc","dd","de","df",
+        "e0","e1","e2","e3","e4","e5","e6","e7","e8","e9","ea","eb","ec","ed","ee","ef",
         "f0","f1","f2","f3","f4","f5","f6","f7","f8","f9","fa","fb","fc","fd","fe","ff"
     };
     unsigned i;
-       
+
     if (debug_level < level) return;
-    
-    fprintf(dbg_out,"%s(%.8llx,%.4x): ",label,offset,len);
-    
+
+    fprintf(dbg_out,"%s(%.8" G_GINT64_MODIFIER "x,%.4x): ",label,offset,len);
+
     for (i=0 ; i<len ; i++) {
-               
+
         if (!(i%32))
             fprintf(dbg_out,"\n");
         else if (!(i%4))
             fprintf(dbg_out," ");
-               
-        fprintf(dbg_out,c2t[b[i]]);
+
+        fprintf(dbg_out, "%s", c2t[b[i]]);
     }
-       
+
        fprintf(dbg_out,"\n");
 }
 
@@ -115,7 +131,7 @@ void k12_hexdump(guint level, gint64 offset, char* label, unsigned char* b, unsi
 /*
  * the 32 bits .rf5 file contains:
  *  an 8 byte magic number
- *  32bit lenght
+ *  32bit length
  *  32bit number of records
  *  other 0x200 bytes bytes of uncharted territory
  *     1 or more copies of the num_of_records in there
@@ -126,15 +142,15 @@ void k12_hexdump(guint level, gint64 offset, char* label, unsigned char* b, unsi
 
 static const guint8 k12_file_magic[] = { 0x00, 0x00, 0x02, 0x00 ,0x12, 0x05, 0x00, 0x10 };
 
-struct _k12_t {
+typedef struct {
     guint32 file_len;
     guint32 num_of_records; /* XXX: not sure about this */
-    
+
     GHashTable* src_by_id; /* k12_srcdsc_recs by input */
     GHashTable* src_by_name; /* k12_srcdsc_recs by stack_name */
 
     Buffer extra_info; /* Buffer to hold per packet extra information */
-};
+} k12_t;
 
 typedef struct _k12_src_desc_t {
     guint32 input;
@@ -145,6 +161,37 @@ typedef struct _k12_src_desc_t {
 } k12_src_desc_t;
 
 
+/*
+ * According to the Tektronix documentation, this value is a combination of
+ * a "group" code and a "type" code, with both being 2-byte values and
+ * with the "group" code followe by the "type" code.  The "group" values
+ * are:
+ *
+ *     0x0001 - "data event"
+ *     0x0002 - "text or L1 event"
+ *     0x0007 - "configuration event"
+ *
+ * and the "type" values are:
+ *
+ *  data events:
+ *     0x0020 - "frame" (i.e., "an actual packet")
+ *     0x0021 - "transparent frame"
+ *     0x0022 - "bit data (TRAU frame)"
+ *     0x0024 - "used to mark the frame which is a fragment"
+ *     0x0026 - "used to mark the frame which is a fragment"
+ *     0x0028 - "used to mark the frame which is generated by the LSA"
+ *     0x002A - "used to mark the frame which is generated by the LSA"
+ *
+ *  text or L1 events:
+ *     0x0030 - "text event"
+ *     0x0031 - "L1 event"
+ *     0x0032 - "L1 event (BAI)"
+ *     0x0033 - "L1 event (VX)"
+ *
+ *  configuration events:
+ *     0x0040 - Logical Data Source configuration event
+ *     0x0041 - Logical Link configuration event
+ */
 /* so far we've seen these types of records */
 #define K12_REC_PACKET        0x00010020 /* an actual packet */
 #define K12_REC_SRCDSC        0x00070041 /* port-stack mapping + more, the key of the whole thing */
@@ -152,24 +199,40 @@ typedef struct _k12_src_desc_t {
 #define K12_REC_STK_FILE      0x00070042 /* a dump of an stk file */
 #define K12_REC_SRCDSC2       0x00070043 /* another port-stack mapping */
 #define K12_REC_TEXT          0x00070044 /* a string containing something with a grammar (conditions/responses?) */
-#define K12_REC_START         0x00020030 /* a string containing human readable start time  */ 
+#define K12_REC_START         0x00020030 /* a string containing human readable start time  */
 #define K12_REC_STOP          0x00020031 /* a string containing human readable stop time */
 
-#define K12_MASK_PACKET       0xfffffff0  /* the last nibble in packet records somentimes change (not yet understood why) */
+/*
+ * According to the Tektronix documentation, packets, i.e. "data events",
+ * have several different group/type values, which differ in the last
+ * nibble of the type code.  For now, we just mask that nibble off; the
+ * format of the items are different, so we might have to treat different
+ * data event types differently.
+ */
+#define K12_MASK_PACKET       0xfffffff0
 
 /* offsets of elements in the records */
-#define K12_RECORD_LEN         0x0 /* uint32, in bytes */ 
+#define K12_RECORD_LEN         0x0 /* uint32, in bytes */
 #define K12_RECORD_TYPE        0x4 /* uint32, see above */
 #define K12_RECORD_FRAME_LEN   0x8 /* uint32, in bytes */
 #define K12_RECORD_SRC_ID      0xc /* uint32 */
 
+/*
+ * Some records from K15 files have a port ID of an undeclared
+ * interface which happens to be the only one with the first byte changed.
+ * It is still unknown how to recognize when this happens.
+ * If the lookup of the interface record fails we'll mask it
+ * and retry.
+ */
+#define K12_RECORD_SRC_ID_MASK 0x00ffffff
+
 /* elements of packet records */
 #define K12_PACKET_TIMESTAMP  0x18 /* int64 (8b) representing 1/2us since 01-01-1990 Z00:00:00 */
 
 #define K12_PACKET_FRAME      0x20 /* start of the actual frame in the record */
 
-#define K12_PACKET_OFFSET_VP  0x08 /* 2 bytes, big endian */ 
-#define K12_PACKET_OFFSET_VC  0x0a /* 2 bytes, big endian */ 
+#define K12_PACKET_OFFSET_VP  0x08 /* 2 bytes, big endian */
+#define K12_PACKET_OFFSET_VC  0x0a /* 2 bytes, big endian */
 #define K12_PACKET_OFFSET_CID 0x0c /* 1 byte */
 
 /* elements of the source description records */
@@ -194,254 +257,312 @@ typedef struct _k12_src_desc_t {
  *   Every about 0x2000 bytes 0x10 bytes are inserted in the file,
  *   even in the middle of a record.
  *   This reads the next record without the eventual 0x10 bytes.
- *   returns the lenght of the record + the stuffing (if any)
+ *   returns the length of the record + the stuffing (if any)
+ *
+ *   Returns number of bytes read on success, 0 on EOF, -1 on error;
+ *   if -1 is returned, *err is set to the error indication and, for
+ *   errors where that's appropriate, *err_info is set to an additional
+ *   error string.
  *
- * XXX: works at most with 0x1FFF bytes per record 
+ * XXX: works at most with 0x1FFF bytes per record
  */
-static gint get_record(guint8** bufferp, FILE* fh, gint64 file_offset) {
-       static guint8* buffer = NULL;
-       static guint buffer_len = 0x2000 ;
-    guint read;
-       guint last_read;
-    guint actual_len, left;
-       guint8 junk[0x14];
-       guint8* readp;
-       
-       /* where the next unknown 0x10 bytes are stuffed to the file */
-       gint64 junky_offset = 0x2000 - ( (file_offset - 0x200) % 0x2000 );
-       
-       K12_DBG(6,("get_record: ENTER: junky_offset=%lld, file_offset=%lld",junky_offset,file_offset));
-
-       /* no buffer is given, lets create it */
-       if (buffer == NULL) {
-               buffer = g_malloc(0x2000);
-               buffer_len = 0x2000;
-       }
-       
-       *bufferp = buffer;
-       
-       if  ( junky_offset == 0x2000 ) {
-               /* the lenght of the record is 0x10 bytes ahead from we are reading */
-               read = file_read(junk,1,0x14,fh);
-        
-        if (read == 2 && junk[0] == 0xff && junk[1] == 0xff) {
-            K12_DBG(1,("get_record: EOF"));            
+static gint get_record(guint8** bufferp, FILE_T fh, gint64 file_offset,
+                       int *err, gchar **err_info) {
+    static guint8* buffer = NULL;
+    static guint buffer_len = 0x2000 ;
+    guint bytes_read;
+    guint last_read;
+    guint left;
+    guint8 junk[0x14];
+    guint8* writep;
+#ifdef DEBUG_K12
+    guint actual_len;
+#endif
+
+    /* where the next unknown 0x10 bytes are stuffed to the file */
+    guint junky_offset = 0x2000 - (gint) ( (file_offset - 0x200) % 0x2000 );
+
+    K12_DBG(6,("get_record: ENTER: junky_offset=%" G_GINT64_MODIFIER "d, file_offset=%" G_GINT64_MODIFIER "d",junky_offset,file_offset));
+
+    /* no buffer is given, lets create it */
+    if (buffer == NULL) {
+        buffer = g_malloc(0x2000);
+        buffer_len = 0x2000;
+    }
+
+    *bufferp = buffer;
+
+    if  ( junky_offset == 0x2000 ) {
+        /* the length of the record is 0x10 bytes ahead from we are reading */
+        bytes_read = file_read(junk,0x14,fh);
+
+        if (bytes_read == 2 && junk[0] == 0xff && junk[1] == 0xff) {
+            K12_DBG(1,("get_record: EOF"));
             return 0;
-        } else if ( read < 0x14 ){
-            K12_DBG(1,("get_record: SHORT READ"));
+        } else if ( bytes_read < 0x14 ){
+            K12_DBG(1,("get_record: SHORT READ OR ERROR"));
+            *err = file_error(fh, err_info);
+            if (*err == 0) {
+                *err = WTAP_ERR_SHORT_READ;
+            }
             return -1;
         }
-               
-               memcpy(buffer,&(junk[0x10]),4);
-       } else {
-               /* the lenght of the record is right where we are reading */
-               read = file_read(buffer,1, 0x4, fh);
-               
-               if (read == 2 && buffer[0] == 0xff && buffer[1] == 0xff) {
+
+        memcpy(buffer,&(junk[0x10]),4);
+    } else {
+        /* the length of the record is right where we are reading */
+        bytes_read = file_read(buffer, 0x4, fh);
+
+        if (bytes_read == 2 && buffer[0] == 0xff && buffer[1] == 0xff) {
             K12_DBG(1,("get_record: EOF"));
             return 0;
-        } else if ( read != 0x4 ) {
-            K12_DBG(1,("get_record: SHORT READ"));
+        } else if ( bytes_read != 0x4 ) {
+            K12_DBG(1,("get_record: SHORT READ OR ERROR"));
+            *err = file_error(fh, err_info);
+            if (*err == 0) {
+                *err = WTAP_ERR_SHORT_READ;
+            }
             return -1;
         }
-       }
-       
-       actual_len = left = pntohl(buffer);
-       junky_offset -= 0x4;
-       
-       K12_DBG(5,("get_record: GET length=%d",left));
-
-       g_assert(left >= 4);
-       
-       while (left > buffer_len) *bufferp = buffer = g_realloc(buffer,buffer_len*=2);
-       
-       readp = buffer + 4;
-       left -= 4;
-       
-       do {
-               K12_DBG(6,("get_record: looping left=%d junky_offset=%lld",left,junky_offset));
-
-               if (junky_offset > left) {
-                       read += last_read = file_read(readp,1, left, fh);
-                       
-                       if ( last_read != left ) {
-                               K12_DBG(1,("get_record: SHORT READ"));
-                               return -1;
-                       } else {
-                               K12_HEXDMP(5,file_offset, "GOT record", buffer, actual_len);
-                               return read;
-                       }
-               } else {
-                       read += last_read = file_read(readp,1, junky_offset, fh);
-                       
-                       if ( last_read != junky_offset ) {
-                               K12_DBG(1,("get_record: SHORT READ, read=%d expected=%d",last_read, junky_offset));
-                               return -1;
-                       }
-                       
-                       readp += last_read;
-
-                       read += last_read = file_read(junk,1, 0x10, fh);
-                       
-                       if ( last_read != 0x10 ) {
-                               K12_DBG(1,("get_record: SHORT READ"));
-                               return -1;
-                       }
-                       
-                       left -= junky_offset;
-                       junky_offset = 0x2000;
-               }
-               
-       } while(left);
-       
-       K12_HEXDMP(5,file_offset, "GOT record", buffer, actual_len);
-       return read;
+    }
+
+    left = pntohl(buffer);
+#ifdef DEBUG_K12
+    actual_len = left;
+#endif
+    junky_offset -= 0x4;
+
+    K12_DBG(5,("get_record: GET length=%u",left));
+
+    /* XXX - Is WTAP_MAX_PACKET_SIZE */
+    if (left < 4 || left > WTAP_MAX_PACKET_SIZE) {
+        K12_DBG(1,("get_record: Invalid GET length=%u",left));
+        *err = WTAP_ERR_BAD_FILE;
+        *err_info = g_strdup_printf("get_record: Invalid GET length=%u",left);
+        return -1;
+    }
+
+    while (left > buffer_len) *bufferp = buffer = g_realloc(buffer,buffer_len*=2);
+
+    writep = buffer + 4;
+    left -= 4;
+
+    do {
+        K12_DBG(6,("get_record: looping left=%d junky_offset=%" G_GINT64_MODIFIER "d",left,junky_offset));
+
+        if (junky_offset > left) {
+            bytes_read += last_read = file_read(writep, left, fh);
+
+            if ( last_read != left ) {
+                K12_DBG(1,("get_record: SHORT READ OR ERROR"));
+                *err = file_error(fh, err_info);
+                if (*err == 0) {
+                    *err = WTAP_ERR_SHORT_READ;
+                }
+                return -1;
+            } else {
+                K12_HEXDMP(5,file_offset, "GOT record", buffer, actual_len);
+                return bytes_read;
+            }
+        } else {
+            bytes_read += last_read = file_read(writep, junky_offset, fh);
+
+            if ( last_read != junky_offset ) {
+                K12_DBG(1,("get_record: SHORT READ OR ERROR, read=%d expected=%d",last_read, junky_offset));
+                *err = file_error(fh, err_info);
+                if (*err == 0) {
+                    *err = WTAP_ERR_SHORT_READ;
+                }
+                return -1;
+            }
+
+            writep += last_read;
+
+            bytes_read += last_read = file_read(junk, 0x10, fh);
+
+            if ( last_read != 0x10 ) {
+                K12_DBG(1,("get_record: SHORT READ OR ERROR"));
+                *err = file_error(fh, err_info);
+                if (*err == 0) {
+                    *err = WTAP_ERR_SHORT_READ;
+                }
+                return -1;
+            }
+
+            left -= junky_offset;
+            junky_offset = 0x2000;
+        }
+
+    } while(left);
+
+    K12_HEXDMP(5,file_offset, "GOT record", buffer, actual_len);
+    return bytes_read;
 }
 
-static gboolean k12_read(wtap *wth, int *err, gchar **err_info _U_, gint64 *data_offset) {
+static gboolean k12_read(wtap *wth, int *err, gchar **err_info, gint64 *data_offset) {
+    k12_t *k12 = (k12_t *)wth->priv;
     k12_src_desc_t* src_desc;
     guint8* buffer = NULL;
     gint64 offset;
-    long len;
+    gint len;
     guint32 type;
-       guint32 src_id;
+    guint32 src_id;
     guint64 ts;
     guint32 extra_len;
-    
+
     offset = wth->data_offset;
-    
-    /* ignore the record if it isn't a packet */    
+
+    /* ignore the record if it isn't a packet */
     do {
-               K12_DBG(5,("k12_read: offset=%i",offset));
-               
+        K12_DBG(5,("k12_read: offset=%i",offset));
+
         *data_offset = offset;
-        
-        len = get_record(&buffer, wth->fh, offset);
-        
+
+        len = get_record(&buffer, wth->fh, offset, err, err_info);
+
         if (len < 0) {
-            *err = WTAP_ERR_SHORT_READ;
             return FALSE;
         } else if (len == 0) {
             *err = 0;
             return FALSE;
         }
-        
+
         type = pntohl(buffer + K12_RECORD_TYPE);
         src_id = pntohl(buffer + K12_RECORD_SRC_ID);
-               src_desc = g_hash_table_lookup(wth->capture.k12->src_by_id,GUINT_TO_POINTER(src_id));
+
+
+        if ( ! (src_desc = g_hash_table_lookup(k12->src_by_id,GUINT_TO_POINTER(src_id))) ) {
+            /*
+             * Some records from K15 files have a port ID of an undeclared
+             * interface which happens to be the only one with the first byte changed.
+             * It is still unknown how to recognize when this happens.
+             * If the lookup of the interface record fails we'll mask it
+             * and retry.
+             */
+            src_desc = g_hash_table_lookup(k12->src_by_id,GUINT_TO_POINTER(src_id&K12_RECORD_SRC_ID_MASK));
+        }
 
         K12_DBG(5,("k12_read: record type=%x src_id=%x",type,src_id));
-        
+
         offset += len;
-        
+
     } while ( ((type & K12_MASK_PACKET) != K12_REC_PACKET) || !src_id || !src_desc );
-    
+
     wth->data_offset = offset;
-    
+
+    wth->phdr.presence_flags = WTAP_HAS_TS;
+
     ts = pntohll(buffer + K12_PACKET_TIMESTAMP);
-    
+
     wth->phdr.ts.secs = (guint32) ((ts / 2000000) + 631152000);
     wth->phdr.ts.nsecs = (guint32) ( (ts % 2000000) * 500 );
-    
+
     K12_DBG(3,("k12_read: PACKET RECORD type=%x src_id=%x secs=%u nsecs=%u",type,src_id, wth->phdr.ts.secs,wth->phdr.ts.nsecs));
-    
+
     wth->phdr.len = wth->phdr.caplen = pntohl(buffer + K12_RECORD_FRAME_LEN) & 0x00001FFF;
     extra_len = len - K12_PACKET_FRAME - wth->phdr.caplen;
-    
+
     /* the frame */
     buffer_assure_space(wth->frame_buffer, wth->phdr.caplen);
     memcpy(buffer_start_ptr(wth->frame_buffer), buffer + K12_PACKET_FRAME, wth->phdr.caplen);
-    
+
     /* extra information need by some protocols */
-    buffer_assure_space(&(wth->capture.k12->extra_info), extra_len);
-    memcpy(buffer_start_ptr(&(wth->capture.k12->extra_info)),
+    buffer_assure_space(&(k12->extra_info), extra_len);
+    memcpy(buffer_start_ptr(&(k12->extra_info)),
            buffer + K12_PACKET_FRAME + wth->phdr.caplen, extra_len);
-    wth->pseudo_header.k12.extra_info = (void*)buffer_start_ptr(&(wth->capture.k12->extra_info));
+    wth->pseudo_header.k12.extra_info = (void*)buffer_start_ptr(&(k12->extra_info));
     wth->pseudo_header.k12.extra_length = extra_len;
 
     wth->pseudo_header.k12.input = src_id;
-    
-    K12_DBG(5,("k12_read: wth->pseudo_header.k12.input=%x wth->phdr.len=%i",wth->pseudo_header.k12.input,wth->phdr.len));
-        
-    if (src_desc) {
-        
-        K12_DBG(5,("k12_read: input_name='%s' stack_file='%s' type=%x",src_desc->input_name,src_desc->stack_file,src_desc->input_type));
-        wth->pseudo_header.k12.input_name = src_desc->input_name;
-        wth->pseudo_header.k12.stack_file = src_desc->stack_file;
-        wth->pseudo_header.k12.input_type = src_desc->input_type;
-        
-        switch(src_desc->input_type) {
-            case K12_PORT_ATMPVC:
-            if ((long)(K12_PACKET_FRAME + wth->phdr.len + K12_PACKET_OFFSET_CID) < len) {
-                wth->pseudo_header.k12.input_info.atm.vp =  pntohs(buffer + (K12_PACKET_FRAME + wth->phdr.caplen + K12_PACKET_OFFSET_VP));
-                wth->pseudo_header.k12.input_info.atm.vc =  pntohs(buffer + (K12_PACKET_FRAME + wth->phdr.caplen + K12_PACKET_OFFSET_VC));
-                wth->pseudo_header.k12.input_info.atm.cid =  *((unsigned char*)(buffer + K12_PACKET_FRAME + wth->phdr.len + K12_PACKET_OFFSET_CID));
-                break;
-            }
-            /* Fall through */
-            default:
-            memcpy(&(wth->pseudo_header.k12.input_info),&(src_desc->input_info),sizeof(src_desc->input_info));
+
+    K12_DBG(5,("k12_read: wth->pseudo_header.k12.input=%x wth->phdr.len=%i input_name='%s' stack_file='%s' type=%x",
+               wth->pseudo_header.k12.input,wth->phdr.len,src_desc->input_name,src_desc->stack_file,src_desc->input_type));\
+
+    wth->pseudo_header.k12.input_name = src_desc->input_name;
+    wth->pseudo_header.k12.stack_file = src_desc->stack_file;
+    wth->pseudo_header.k12.input_type = src_desc->input_type;
+
+    switch(src_desc->input_type) {
+        case K12_PORT_ATMPVC:
+        if ((long)(K12_PACKET_FRAME + wth->phdr.len + K12_PACKET_OFFSET_CID) < len) {
+            wth->pseudo_header.k12.input_info.atm.vp =  pntohs(buffer + (K12_PACKET_FRAME + wth->phdr.caplen + K12_PACKET_OFFSET_VP));
+            wth->pseudo_header.k12.input_info.atm.vc =  pntohs(buffer + (K12_PACKET_FRAME + wth->phdr.caplen + K12_PACKET_OFFSET_VC));
+            wth->pseudo_header.k12.input_info.atm.cid =  *((unsigned char*)(buffer + K12_PACKET_FRAME + wth->phdr.len + K12_PACKET_OFFSET_CID));
             break;
-            
         }
-    } else {
-        K12_DBG(5,("k12_read: NO RECORD FOUND"));
+        /* Fall through */
+        default:
+        memcpy(&(wth->pseudo_header.k12.input_info),&(src_desc->input_info),sizeof(src_desc->input_info));
+        break;
 
-        memset(&(wth->pseudo_header),0,sizeof(wth->pseudo_header));
-        wth->pseudo_header.k12.input_name = "unknown port";
-        wth->pseudo_header.k12.stack_file = "unknown stack file";
     }
-    
-    wth->pseudo_header.k12.stuff = wth->capture.k12;
-    
+
+    wth->pseudo_header.k12.stuff = k12;
+
     return TRUE;
 }
 
 
-static gboolean k12_seek_read(wtap *wth, gint64 seek_off, union wtap_pseudo_header *pseudo_header, guchar *pd, int length, int *err _U_, gchar **err_info _U_) {
+static gboolean k12_seek_read(wtap *wth, gint64 seek_off, union wtap_pseudo_header *pseudo_header, guint8 *pd, int length, int *err _U_, gchar **err_info) {
+    k12_t *k12 = (k12_t *)wth->priv;
     k12_src_desc_t* src_desc;
     guint8* buffer;
-    long len;
+    gint len;
     guint32 extra_len;
     guint32 input;
-    
+
     K12_DBG(5,("k12_seek_read: ENTER"));
-    
+
     if ( file_seek(wth->random_fh, seek_off, SEEK_SET, err) == -1) {
         K12_DBG(5,("k12_seek_read: SEEK ERROR"));
         return FALSE;
     }
-    
-    if ((len = get_record(&buffer, wth->random_fh, seek_off)) < 1) {
+
+    len = get_record(&buffer, wth->random_fh, seek_off, err, err_info);
+    if (len < 0) {
         K12_DBG(5,("k12_seek_read: READ ERROR"));
         return FALSE;
     }
-    
+    if (len < 1) {
+        K12_DBG(5,("k12_seek_read: SHORT READ"));
+        *err = WTAP_ERR_SHORT_READ;
+        return FALSE;
+    }
+
     memcpy(pd, buffer + K12_PACKET_FRAME, length);
 
     extra_len = len - K12_PACKET_FRAME - length;
-    buffer_assure_space(&(wth->capture.k12->extra_info), extra_len);
-    memcpy(buffer_start_ptr(&(wth->capture.k12->extra_info)),
+    buffer_assure_space(&(k12->extra_info), extra_len);
+    memcpy(buffer_start_ptr(&(k12->extra_info)),
            buffer + K12_PACKET_FRAME + length, extra_len);
-    wth->pseudo_header.k12.extra_info = (void*)buffer_start_ptr(&(wth->capture.k12->extra_info));
+    wth->pseudo_header.k12.extra_info = (void*)buffer_start_ptr(&(k12->extra_info));
     wth->pseudo_header.k12.extra_length = extra_len;
     if (pseudo_header) {
-        pseudo_header->k12.extra_info = (void*)buffer_start_ptr(&(wth->capture.k12->extra_info));
+        pseudo_header->k12.extra_info = (void*)buffer_start_ptr(&(k12->extra_info));
         pseudo_header->k12.extra_length = extra_len;
     }
-    
+
     input = pntohl(buffer + K12_RECORD_SRC_ID);
     K12_DBG(5,("k12_seek_read: input=%.8x",input));
-    
-    src_desc = g_hash_table_lookup(wth->capture.k12->src_by_id,GUINT_TO_POINTER(input));
-    
+
+    if ( ! (src_desc = g_hash_table_lookup(k12->src_by_id,GUINT_TO_POINTER(input))) ) {
+        /*
+         * Some records from K15 files have a port ID of an undeclared
+         * interface which happens to be the only one with the first byte changed.
+         * It is still unknown how to recognize when this happens.
+         * If the lookup of the interface record fails we'll mask it
+         * and retry.
+         */
+        src_desc = g_hash_table_lookup(k12->src_by_id,GUINT_TO_POINTER(input&K12_RECORD_SRC_ID_MASK));
+    }
+
     if (src_desc) {
         K12_DBG(5,("k12_seek_read: input_name='%s' stack_file='%s' type=%x",src_desc->input_name,src_desc->stack_file,src_desc->input_type));
         if (pseudo_header) {
             pseudo_header->k12.input_name = src_desc->input_name;
             pseudo_header->k12.stack_file = src_desc->stack_file;
             pseudo_header->k12.input_type = src_desc->input_type;
-            
+
             switch(src_desc->input_type) {
             case K12_PORT_ATMPVC:
                 if ((long)(K12_PACKET_FRAME + length + K12_PACKET_OFFSET_CID) < len) {
@@ -456,11 +577,11 @@ static gboolean k12_seek_read(wtap *wth, gint64 seek_off, union wtap_pseudo_head
                 break;
             }
         }
-        
+
         wth->pseudo_header.k12.input_name = src_desc->input_name;
         wth->pseudo_header.k12.stack_file = src_desc->stack_file;
         wth->pseudo_header.k12.input_type = src_desc->input_type;
-            
+
         switch(src_desc->input_type) {
             case K12_PORT_ATMPVC:
             if ((long)(K12_PACKET_FRAME + length + K12_PACKET_OFFSET_CID) < len) {
@@ -474,7 +595,7 @@ static gboolean k12_seek_read(wtap *wth, gint64 seek_off, union wtap_pseudo_head
             memcpy(&(wth->pseudo_header.k12.input_info),&(src_desc->input_info),sizeof(src_desc->input_info));
             break;
         }
-        
+
     } else {
         K12_DBG(5,("k12_seek_read: NO SRC_RECORD FOUND"));
 
@@ -487,16 +608,16 @@ static gboolean k12_seek_read(wtap *wth, gint64 seek_off, union wtap_pseudo_head
         memset(&(wth->pseudo_header.k12),0,sizeof(wth->pseudo_header.k12));
         wth->pseudo_header.k12.input_name = "unknown port";
         wth->pseudo_header.k12.stack_file = "unknown stack file";
-        
+
     }
-    
+
     if (pseudo_header) {
         pseudo_header->k12.input = input;
-        pseudo_header->k12.stuff = wth->capture.k12;
+        pseudo_header->k12.stuff = k12;
     }
-    
+
     wth->pseudo_header.k12.input = input;
-    wth->pseudo_header.k12.stuff = wth->capture.k12;
+    wth->pseudo_header.k12.stuff = k12;
 
     K12_DBG(5,("k12_seek_read: DONE OK"));
 
@@ -504,43 +625,42 @@ static gboolean k12_seek_read(wtap *wth, gint64 seek_off, union wtap_pseudo_head
 }
 
 
-static k12_t* new_k12_file_data() {
+static k12_t* new_k12_file_data(void) {
     k12_t* fd = g_malloc(sizeof(k12_t));
-    
+
     fd->file_len = 0;
     fd->num_of_records = 0;
     fd->src_by_name = g_hash_table_new(g_str_hash,g_str_equal);
     fd->src_by_id = g_hash_table_new(g_direct_hash,g_direct_equal);
 
     buffer_init(&(fd->extra_info), 100);
-    
+
     return fd;
 }
 
 static gboolean destroy_srcdsc(gpointer k _U_, gpointer v, gpointer p _U_) {
     k12_src_desc_t* rec = v;
-    
-    if(rec->input_name)
-        g_free(rec->input_name);
-    
-    if(rec->stack_file)
-        g_free(rec->stack_file);
-    
+
+    g_free(rec->input_name);
+    g_free(rec->stack_file);
     g_free(rec);
-    
+
     return TRUE;
 }
 
 static void destroy_k12_file_data(k12_t* fd) {
     g_hash_table_destroy(fd->src_by_id);
-    g_hash_table_foreach_remove(fd->src_by_name,destroy_srcdsc,NULL);    
+    g_hash_table_foreach_remove(fd->src_by_name,destroy_srcdsc,NULL);
     g_hash_table_destroy(fd->src_by_name);
     buffer_free(&(fd->extra_info));
     g_free(fd);
 }
 
 static void k12_close(wtap *wth) {
-    destroy_k12_file_data(wth->capture.k12);
+    k12_t *k12 = (k12_t *)wth->priv;
+
+    destroy_k12_file_data(k12);
+    wth->priv = NULL;  /* destroy_k12_file_data freed it */
 #ifdef DEBUG_K12
     K12_DBG(5,("k12_close: CLOSED"));
     if (env_file) fclose(dbg_out);
@@ -548,7 +668,7 @@ static void k12_close(wtap *wth) {
 }
 
 
-int k12_open(wtap *wth, int *err, gchar **err_info _U_) {
+int k12_open(wtap *wth, int *err, gchar **err_info) {
     k12_src_desc_t* rec;
     guint8 header_buffer[0x200];
     guint8* read_buffer;
@@ -561,18 +681,22 @@ int k12_open(wtap *wth, int *err, gchar **err_info _U_) {
     guint32 stack_len;
     guint i;
     k12_t* file_data;
-    
+
 #ifdef DEBUG_K12
     gchar* env_level = getenv("K12_DEBUG_LEVEL");
     env_file = getenv("K12_DEBUG_FILENAME");
-    if ( env_file ) dbg_out = fopen(env_file,"w");
+    if ( env_file ) dbg_out = ws_fopen(env_file,"w");
     else dbg_out = stderr;
     if ( env_level ) debug_level = strtoul(env_level,NULL,10);
     K12_DBG(1,("k12_open: ENTER debug_level=%u",debug_level));
 #endif
-    
-    if ( file_read(header_buffer,1,0x200,wth->fh) != 0x200 ) {
-        K12_DBG(1,("k12_open: FILE HEADER TOO SHORT"));
+
+    if ( file_read(header_buffer,0x200,wth->fh) != 0x200 ) {
+        K12_DBG(1,("k12_open: FILE HEADER TOO SHORT OR READ ERROR"));
+        *err = file_error(wth->fh, err_info);
+        if (*err != 0) {
+            return -1;
+        }
         return 0;
     } else {
         if ( memcmp(header_buffer,k12_file_magic,8) != 0 ) {
@@ -580,58 +704,70 @@ int k12_open(wtap *wth, int *err, gchar **err_info _U_) {
             return 0;
         }
     }
-    
+
     offset = 0x200;
-    
+
     file_data = new_k12_file_data();
-    
+
     file_data->file_len = pntohl( header_buffer + 0x8);
     file_data->num_of_records = pntohl( header_buffer + 0xC );
-    
+
     K12_DBG(5,("k12_open: FILE_HEADER OK: offset=%x file_len=%i records=%i",
             offset,
             file_data->file_len,
             file_data->num_of_records ));
-    
+
     do {
-        
-        len = get_record(&read_buffer, wth->fh, offset);
-        
-        if ( len <= 0 ) {
+
+        len = get_record(&read_buffer, wth->fh, offset, err, err_info);
+
+        if ( len < 0 ) {
             K12_DBG(1,("k12_open: BAD HEADER RECORD",len));
+            destroy_k12_file_data(file_data);
+            g_free(file_data);
             return -1;
         }
-        
-        
+        if (len == 0) {
+            K12_DBG(1,("k12_open: BAD HEADER RECORD",len));
+            *err = WTAP_ERR_SHORT_READ;
+            destroy_k12_file_data(file_data);
+            g_free(file_data);
+            return -1;
+        }
+
+
         type = pntohl( read_buffer + K12_RECORD_TYPE );
-        
+
         if ( (type & K12_MASK_PACKET) == K12_REC_PACKET) {
             /*
              * we are at the first packet record, rewind and leave.
              */
             if (file_seek(wth->fh, offset, SEEK_SET, err) == -1) {
                 destroy_k12_file_data(file_data);
+                g_free(file_data);
                 return -1;
             }
             K12_DBG(5,("k12_open: FIRST PACKET offset=%x",offset));
             break;
         } else if (type == K12_REC_SRCDSC || type == K12_REC_SRCDSC2 ) {
             rec = g_malloc0(sizeof(k12_src_desc_t));
-            
+
             rec_len = pntohl( read_buffer + K12_RECORD_LEN );
             extra_len = pntohs( read_buffer + K12_SRCDESC_EXTRALEN );
             name_len = pntohs( read_buffer + K12_SRCDESC_NAMELEN );
             stack_len = pntohs( read_buffer + K12_SRCDESC_STACKLEN );
-            
+
             rec->input = pntohl( read_buffer + K12_RECORD_SRC_ID );
-            
+
             K12_DBG(5,("k12_open: INTERFACE RECORD offset=%x interface=%x",offset,rec->input));
-            
+
             if (name_len == 0 || stack_len == 0
                 || 0x20 + extra_len + name_len + stack_len > rec_len ) {
                 g_free(rec);
                 K12_DBG(5,("k12_open: failed (name_len == 0 || stack_len == 0 "
                         "|| 0x20 + extra_len + name_len + stack_len > rec_len)  extra_len=%i name_len=%i stack_len=%i"));
+                destroy_k12_file_data(file_data);
+                g_free(file_data);
                 return 0;
             }
 
@@ -639,12 +775,12 @@ int k12_open(wtap *wth, int *err, gchar **err_info _U_) {
                 switch(( rec->input_type = pntohl( read_buffer + K12_SRCDESC_EXTRATYPE ) )) {
                     case K12_PORT_DS0S:
                         rec->input_info.ds0mask = 0x00000000;
-                        
+
                         for (i = 0; i < 32; i++) {
-                            rec->input_info.ds0mask |= ( *(read_buffer + K12_SRCDESC_DS0_MASK + i) == 0xff ) ? 0x1<<(31-i) : 0x0; 
+                            rec->input_info.ds0mask |= ( *(read_buffer + K12_SRCDESC_DS0_MASK + i) == 0xff ) ? 0x1<<(31-i) : 0x0;
                         }
-                        
-                            break;
+
+                        break;
                     case K12_PORT_ATMPVC:
                         rec->input_info.atm.vp = pntohs( read_buffer + K12_SRCDESC_ATM_VPI );
                         rec->input_info.atm.vc = pntohs( read_buffer + K12_SRCDESC_ATM_VCI );
@@ -656,19 +792,25 @@ int k12_open(wtap *wth, int *err, gchar **err_info _U_) {
                    don't have this information */
                 if (read_buffer[K12_SRCDESC_PORT_TYPE] >= 0x14
                     && read_buffer[K12_SRCDESC_PORT_TYPE] <= 0x17)
-                    /* For ATM2_E1DS1, ATM2_E3DS3, 
+                    /* For ATM2_E1DS1, ATM2_E3DS3,
                        ATM2_STM1EL and ATM2_STM1OP */
                     rec->input_type = K12_PORT_ATMPVC;
             }
 
+            /* XXX - this is assumed, in a number of places (not just in the
+               ascii_strdown_inplace() call below) to be null-terminated;
+               is that guaranteed (even with a corrupt file)?
+              Obviously not, as a corrupt file could contain anything
+              here; the Tektronix document says the strings "must end
+              with \0", but a bad file could fail to add the \0. */
             rec->input_name = g_memdup(read_buffer + K12_SRCDESC_EXTRATYPE + extra_len, name_len);
             rec->stack_file = g_memdup(read_buffer + K12_SRCDESC_EXTRATYPE + extra_len + name_len, stack_len);
-            
-            g_strdown(rec->stack_file);
-            
+
+            ascii_strdown_inplace (rec->stack_file);
+
             g_hash_table_insert(file_data->src_by_id,GUINT_TO_POINTER(rec->input),rec);
             g_hash_table_insert(file_data->src_by_name,rec->stack_file,rec);
-            
+
             offset += len;
             continue;
         } else {
@@ -676,7 +818,7 @@ int k12_open(wtap *wth, int *err, gchar **err_info _U_) {
             continue;
         }
     } while(1);
-    
+
     wth->data_offset = offset;
     wth->file_type = WTAP_FILE_K12;
     wth->file_encap = WTAP_ENCAP_K12;
@@ -684,44 +826,55 @@ int k12_open(wtap *wth, int *err, gchar **err_info _U_) {
     wth->subtype_read = k12_read;
     wth->subtype_seek_read = k12_seek_read;
     wth->subtype_close = k12_close;
-    wth->capture.k12 = file_data;
-    wth->tsprecision = WTAP_FILE_TSPREC_NSEC;    
+    wth->priv = (void *)file_data;
+    wth->tsprecision = WTAP_FILE_TSPREC_NSEC;
 
     return 1;
 }
 
+typedef struct {
+       guint32 file_len;
+       guint32 num_of_records;
+       guint32 file_offset;
+} k12_dump_t;
+
 int k12_dump_can_write_encap(int encap) {
-    
+
     if (encap == WTAP_ENCAP_PER_PACKET)
         return WTAP_ERR_ENCAP_PER_PACKET_UNSUPPORTED;
-    
+
     if (encap != WTAP_ENCAP_K12)
         return WTAP_ERR_UNSUPPORTED_ENCAP;
-    
+
     return 0;
 }
 
 static const gchar dumpy_junk[] = { 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 };
 
-static void k12_dump_record(wtap_dumper *wdh, long len,  guint8* buffer) {
-    long junky_offset = (0x2000 - ( (wdh->dump.k12->file_offset - 0x200) % 0x2000 )) % 0x2000;
-    
+static gboolean k12_dump_record(wtap_dumper *wdh, guint32 len,  guint8* buffer, int *err_p) {
+    k12_dump_t *k12 = (k12_dump_t *)wdh->priv;
+    guint32 junky_offset = (0x2000 - ( (k12->file_offset - 0x200) % 0x2000 )) % 0x2000;
+
     if (len > junky_offset) {
-        
-        if (junky_offset)
-            fwrite(buffer, 1, junky_offset, wdh->fh);
-        
-        fwrite(dumpy_junk, 1, 0x10, wdh->fh);
-        
-        fwrite(buffer+junky_offset, 1, len - junky_offset, wdh->fh);
-        
-        wdh->dump.k12->file_offset += len + 0x10;
+        if (junky_offset) {
+            if (! wtap_dump_file_write(wdh, buffer, junky_offset, err_p))
+                return FALSE;
+        }
+        if (! wtap_dump_file_write(wdh, dumpy_junk, 0x10, err_p))
+            return FALSE;
+
+        if (! wtap_dump_file_write(wdh, buffer+junky_offset, len - junky_offset, err_p))
+            return FALSE;
+
+        k12->file_offset += len + 0x10;
     } else {
-        fwrite(buffer, 1, len, wdh->fh);
-        wdh->dump.k12->file_offset += len;
+        if (! wtap_dump_file_write(wdh, buffer, len, err_p))
+            return FALSE;
+        k12->file_offset += len;
     }
-    
-    wdh->dump.k12->num_of_records++;
+
+    k12->num_of_records++;
+    return TRUE;
 }
 
 static void k12_dump_src_setting(gpointer k _U_, gpointer v, gpointer p) {
@@ -730,51 +883,52 @@ static void k12_dump_src_setting(gpointer k _U_, gpointer v, gpointer p) {
     guint32 len;
     guint offset;
     guint i;
-    
+    int   errxxx; /* dummy */
+
     union {
         guint8 buffer[0x2000];
-        
+
         struct {
             guint32 len;
             guint32 type;
             guint32 unk32_1;
             guint32 input;
-            
+
             guint16 unk32_2;
             guint16 color;
             guint32 unk32_3;
             guint32 unk32_4;
             guint16 unk16_1;
             guint16 extra_len;
-            
+
             guint16 name_len;
             guint16 stack_len;
-            
+
             struct {
                 guint32 type;
-                
+
                 union {
                     struct {
                         guint32 unk32;
                         guint8 mask[32];
                     } ds0mask;
-                    
+
                     struct {
                         guint8 unk_data[0x10];
                         guint16 vp;
                         guint16 vc;
                     } atm;
-                    
+
                     guint32 unk;
                 } desc;
             } extra;
         } record;
     } obj;
-    
+
     obj.record.type = g_htonl(K12_REC_SRCDSC);
     obj.record.unk32_1 = g_htonl(0x00000001);
     obj.record.input = g_htonl(src_desc->input);
-    
+
     obj.record.unk32_2 = g_htons(0x0000);
     obj.record.color = g_htons(0x060f);
     obj.record.unk32_3 = g_htonl(0x00000003);
@@ -785,13 +939,13 @@ static void k12_dump_src_setting(gpointer k _U_, gpointer v, gpointer p) {
         default:
             obj.record.unk32_4 = g_htonl(0x01000100);
     }
-    
+
     obj.record.unk16_1 = g_htons(0x0000);
-    obj.record.name_len = strlen(src_desc->input_name) + 1;
-    obj.record.stack_len = strlen(src_desc->stack_file) + 1;
-    
+    obj.record.name_len = (guint16) strlen(src_desc->input_name) + 1;
+    obj.record.stack_len = (guint16) strlen(src_desc->stack_file) + 1;
+
     obj.record.extra.type = g_htonl(src_desc->input_type);
-    
+
     switch (src_desc->input_type) {
         case K12_PORT_ATMPVC:
             obj.record.extra_len = g_htons(0x18);
@@ -812,29 +966,30 @@ static void k12_dump_src_setting(gpointer k _U_, gpointer v, gpointer p) {
             offset = 0x2c;
             break;
     }
-    
+
     memcpy(obj.buffer + offset,
            src_desc->input_name,
            obj.record.name_len);
-    
+
     memcpy(obj.buffer + offset + obj.record.name_len,
            src_desc->stack_file,
            obj.record.stack_len);
-    
+
     len = offset + obj.record.name_len + obj.record.stack_len;
     len += (len % 4) ? 4 - (len % 4) : 0;
-    
+
     obj.record.len = g_htonl(len);
     obj.record.name_len =  g_htons(obj.record.name_len);
     obj.record.stack_len = g_htons(obj.record.stack_len);
-    
-    k12_dump_record(wdh,len,obj.buffer);
+
+    k12_dump_record(wdh,len,obj.buffer, &errxxx); /* fwrite errs ignored: see k12_dump below */
 }
 
 static gboolean k12_dump(wtap_dumper *wdh, const struct wtap_pkthdr *phdr,
                          const union wtap_pseudo_header *pseudo_header,
-                         const guchar *pd, int *err _U_) {
-    long len;
+                         const guint8 *pd, int *err) {
+    k12_dump_t *k12 = (k12_dump_t *)wdh->priv;
+    guint32 len;
     union {
         guint8 buffer[0x2000];
         struct {
@@ -842,93 +997,94 @@ static gboolean k12_dump(wtap_dumper *wdh, const struct wtap_pkthdr *phdr,
             guint32 type;
             guint32 frame_len;
             guint32 input;
-            
+
             guint32 datum_1;
             guint32 datum_2;
             guint64 ts;
-            
+
             guint8 frame[0x1fc0];
         } record;
     } obj;
-    
-    if (wdh->dump.k12->num_of_records == 0) {
+
+    if (k12->num_of_records == 0) {
         k12_t* file_data = pseudo_header->k12.stuff;
+        /* XXX: We'll assume that any fwrite errors in k12_dump_src_setting will    */
+        /*      repeat during the final k12_dump_record at the end of k12_dump      */
+        /*      (and thus cause an error return from k12_dump).                     */
+        /*      (I don't see a reasonably clean way to handle any fwrite errors     */
+        /*       encountered in k12_dump_src_setting).                              */
         g_hash_table_foreach(file_data->src_by_id,k12_dump_src_setting,wdh);
     }
-    
     obj.record.len = 0x20 + phdr->len;
     obj.record.len += (obj.record.len % 4) ? 4 - obj.record.len % 4 : 0;
-    
+
     len = obj.record.len;
-    
+
     obj.record.len = g_htonl(obj.record.len);
-    
+
     obj.record.type = g_htonl(K12_REC_PACKET);
     obj.record.frame_len = g_htonl(phdr->len);
     obj.record.input = g_htonl(pseudo_header->k12.input);
-    
+
     obj.record.ts = GUINT64_TO_BE((((guint64)phdr->ts.secs - 631152000) * 2000000) + (phdr->ts.nsecs / 1000 * 2));
-    
+
     memcpy(obj.record.frame,pd,phdr->len);
-    
-    k12_dump_record(wdh,len,obj.buffer);
-    
-    /* XXX if OK */
-    return TRUE;
+
+    return k12_dump_record(wdh,len,obj.buffer, err);
 }
 
 static const guint8 k12_eof[] = {0xff,0xff};
 
 static gboolean k12_dump_close(wtap_dumper *wdh, int *err) {
+    k12_dump_t *k12 = (k12_dump_t *)wdh->priv;
     union {
         guint8 b[sizeof(guint32)];
         guint32 u;
     } d;
-    
-    fwrite(k12_eof, 1, 2, wdh->fh);
-    
+
+    if (! wtap_dump_file_write(wdh, k12_eof, 2, err))
+        return FALSE;
+
     if (fseek(wdh->fh, 8, SEEK_SET) == -1) {
         *err = errno;
         return FALSE;
     }
-    
-    d.u = g_htonl(wdh->dump.k12->file_len);
-    
-    fwrite(d.b, 1, 4, wdh->fh);
-    
-    d.u = g_htonl(wdh->dump.k12->num_of_records);
-    
-    fwrite(d.b, 1, 4, wdh->fh);
-    
+
+    d.u = g_htonl(k12->file_len);
+
+    if (! wtap_dump_file_write(wdh, d.b, 4, err))
+        return FALSE;
+
+    d.u = g_htonl(k12->num_of_records);
+
+    if (! wtap_dump_file_write(wdh, d.b, 4, err))
+        return FALSE;
+
     return TRUE;
 }
 
 
-gboolean k12_dump_open(wtap_dumper *wdh, gboolean cant_seek, int *err) {
-    
-    if (cant_seek) {
-        *err = WTAP_ERR_CANT_WRITE_TO_PIPE;
-        return FALSE;
-    }
-    
-    if ( fwrite(k12_file_magic, 1, 8, wdh->fh) != 8 ) {
-        *err = errno;
+gboolean k12_dump_open(wtap_dumper *wdh, int *err) {
+    k12_dump_t *k12;
+
+    if ( ! wtap_dump_file_write(wdh, k12_file_magic, 8, err)) {
         return FALSE;
     }
-    
+
     if (fseek(wdh->fh, 0x200, SEEK_SET) == -1) {
         *err = errno;
         return FALSE;
     }
-    
+
     wdh->subtype_write = k12_dump;
     wdh->subtype_close = k12_dump_close;
-    
-    wdh->dump.k12 = g_malloc(sizeof(k12_dump_t));
-    wdh->dump.k12->file_len = 0x200;
-    wdh->dump.k12->num_of_records = 0;
-    wdh->dump.k12->file_offset  = 0x200;
-    
+
+    k12 = (k12_dump_t *)g_malloc(sizeof(k12_dump_t));
+    wdh->priv = (void *)k12;
+    k12->file_len = 0x200;
+    k12->num_of_records = 0;
+    k12->file_offset  = 0x200;
+
     return TRUE;
 }