Make sure the packet length isn't > WTAP_MAX_PACKET_SIZE.
[metze/wireshark/wip.git] / wiretap / k12.c
index 5ac6daac072bb4791e9ccad150228e39957d5035..b5558a0cf44667c9b78f47be4a715cd1cf234360 100644 (file)
@@ -3,9 +3,7 @@
  *
  *  routines for importing tektronix k12xx *.rf5 files
  *
- *  Copyright (c) 2005, Luis E. Garia Ontanon <luis.ontanon@gmail.com>
- *
- * $Id$
+ *  Copyright (c) 2005, Luis E. Garia Ontanon <luis@ontanon.org>
  *
  * Wiretap Library
  * Copyright (c) 1998 by Gilbert Ramirez <gram@alumni.rice.edu>
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 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://www.tek.com/manual/record-file-api-programmer-manual
+ *
+ * for some information about the file format.  You may have to fill in
+ * a form to download the document ("Record 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;
 
-static unsigned debug_level = 0;
+static unsigned int debug_level = 0;
 
-void k12_fprintf(char* fmt, ...) {
+void k12_fprintf(const 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
 #define K12_DBG(level,args) do { if (level <= debug_level) { \
-       fprintf(dbg_out,"%s:%d: ",CAT(__FI,LE__),CAT(__LI,NE__)); \
-       k12_fprintf args ; \
-       fprintf(dbg_out,"\n"); \
+            fprintf(dbg_out,"%s:%d: ",CAT(__FI,LE__),CAT(__LI,NE__));   \
+            k12_fprintf args ;                                          \
+            fprintf(dbg_out,"\n");                                      \
 } } while(0)
 
-void k12_hexdump(guint level, gint64 offset, char* label, unsigned char* b, unsigned len) {
+void k12_hex_ascii_dump(guint level, gint64 offset, const char* label, const unsigned char* b, unsigned int 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;
-       
+    unsigned int i, j;
+
     if (debug_level < level) return;
-    
-    fprintf(dbg_out,"%s(%.8llx,%.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(%.8" G_GINT64_MODIFIER "x,%.4x):\n",label,offset,len);
+
+    for (i=0 ; i<len ; i += 16) {
+        for (j=0; j<16; j++) {
+            if ((j%4)==0)
+                fprintf(dbg_out," ");
+            if ((i+j)<len)
+                fprintf(dbg_out, "%s", c2t[b[i+j]]);
+            else
+                fprintf(dbg_out, "  ");
+        }
+        fprintf(dbg_out, "    ");
+        for (j=0; j<16; j++) {
+            if ((i+j)<len)
+                fprintf(dbg_out, "%c", g_ascii_isprint(b[i+j]) ? b[i+j] : '.');
+        }
+        fprintf(dbg_out,"\n");
     }
-       
-       fprintf(dbg_out,"\n");
 }
 
-#define K12_HEXDMP(x,a,b,c,d) k12_hexdump(x,a,b,c,d)
+#define K12_HEX_ASCII_DUMP(x,a,b,c,d) k12_hex_ascii_dump(x,a,b,c,d)
+
+void k12_ascii_dump(guint level, guint8 *buf, guint32 len, guint32 buf_offset) {
+    guint32 i;
+
+    if (debug_level < level) return;
+
+    for (i = buf_offset; i < len; i++) {
+        if (g_ascii_isprint(buf[i]) || buf[i] == '\n' || buf[i] == '\t')
+            putc(buf[i], dbg_out);
+        else if (buf[i] == '\0')
+            fprintf(dbg_out, "(NUL)\n");
+    }
+}
+
+#define K12_ASCII_DUMP(x,a,b,c) k12_ascii_dump(x,a,b,c)
 
 #else
 #define K12_DBG(level,args) (void)0
-#define K12_HEXDMP(x,a,b,c,d)
+#define K12_HEX_ASCII_DUMP(x,a,b,c,d)
+#define K12_ASCII_DUMP(x,a,b,c)
 #endif
 
 
 
 /*
- * the 32 bits .rf5 file contains:
- *  an 8 byte magic number
- *  32bit lenght
- *  32bit number of records
- *  other 0x200 bytes bytes of uncharted territory
- *     1 or more copies of the num_of_records in there
- *  the records whose first 32bits word is the length
- *     they are stuffed by one to four words every 0x2000 bytes
- *  and a 2 byte terminator FFFF
+ * A 32-bit .rf5 file begins with a 512-byte file header, containing:
+ *
+ *  a 32-bit big-endian file header length, in bytes - always 512 in
+ *  the files we've seen;
+ *
+ *  4 unknown bytes, always 0x12 0x05 0x00 0x10;
+ *
+ *  a 32-bit big-endian file length, giving the total length of the file,
+ *  in bytes;
+ *
+ *  a 32-bit big-endian number giving the "page size" of the file, in
+ *  bytes, which is normally 8192;
+ *
+ *  20 unknown bytes;
+ *
+ *  a 32-bit count of the number of records in the file;
+ *
+ *  4 unknown bytes;
+ *
+ *  a 32-bit count of the number of records in the file;
+ *
+ *  464 unknown bytes;
+ *
+ * followed by a sequence of records containing:
+ *
+ *  a 32-bit big-endian record length;
+ *
+ *  a 32-bit big-endian record type;
+ *
+ *  a 32-bit big-endian frame length;
+ *
+ *  a 32-bit big-endian source ID.
+ *
+ * Every 8192 bytes, starting immediately after the 512-byte header,
+ * there's a 16-byte blob; it's not part of the record data.
+ * There's no obvious pattern to the data; it might be junk left
+ * in memory as the file was being written.
+ *
+ * There's a 16-bit terminator FFFF at the end.
+ *
+ * Older versions of the Wireshark .rf5 writing code incorrectly wrote
+ * the header - they put 512 in the file length field (counting only the
+ * header), put a count of records into the "page size" field, and wrote
+ * out zeroes in the rest of the header.  We detect those files by
+ * checking whether the rest of the header is zero.
  */
 
+/*
+ * We use the first 8 bytes of the file header as a magic number.
+ */
 static const guint8 k12_file_magic[] = { 0x00, 0x00, 0x02, 0x00 ,0x12, 0x05, 0x00, 0x10 };
 
-struct _k12_t {
+#define K12_FILE_HDR_LEN      512
+
+/*
+ * Offsets in the file header.
+ */
+#define K12_FILE_HDR_MAGIC_NUMBER   0x00
+#define K12_FILE_HDR_FILE_SIZE      0x08
+#define K12_FILE_HDR_PAGE_SIZE      0x0C
+#define K12_FILE_HDR_RECORD_COUNT_1 0x24
+#define K12_FILE_HDR_RECORD_COUNT_2 0x2C
+
+#define K12_FILE_BLOB_LEN     16
+
+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 */
+    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 */
+
+    guint8 *seq_read_buff;    /* read buffer for sequential reading */
+    guint seq_read_buff_len;  /* length of that buffer */
+    guint8 *rand_read_buff;   /* read buffer for random reading */
+    guint rand_read_buff_len; /* length of that buffer */
 
-    Buffer extra_info; /* Buffer to hold per packet extra information */
-};
+    Buffer extra_info;        /* Buffer to hold per packet extra information */
+} k12_t;
 
 typedef struct _k12_src_desc_t {
     guint32 input;
@@ -145,358 +232,525 @@ 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 */
+#define K12_REC_D0020         0x000d0020 /* an actual packet, seen in a k18 file */
 #define K12_REC_SCENARIO      0x00070040 /* what appears as the window's title */
+#define K12_REC_SRCDSC        0x00070041 /* port-stack mapping + more, the key of the whole thing */
 #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_FRAME_D0020 0x34 /* 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 */
 #define K12_SRCDESC_COLOR_FOREGROUND 0x12 /* 1 byte */
 #define K12_SRCDESC_COLOR_BACKGROUND 0x13 /* 1 byte */
 
-#define K12_SRCDESC_PORT_TYPE  0x1a   /* 1 byte */
-#define K12_SRCDESC_EXTRALEN   0x1e   /* uint16, big endian */
-#define K12_SRCDESC_NAMELEN    0x20   /* uint16, big endian */
-#define K12_SRCDESC_STACKLEN   0x22   /* uint16, big endian */
+#define K12_SRCDESC_PORT_TYPE  0x1a /* 1 byte */
+#define K12_SRCDESC_HWPARTLEN  0x1e /* uint16, big endian */
+#define K12_SRCDESC_NAMELEN    0x20 /* uint16, big endian */
+#define K12_SRCDESC_STACKLEN   0x22 /* uint16, big endian */
+
+/* Hardware part of the record */
+#define K12_SRCDESC_HWPART     0x24 /* offset of the hardware part */
 
-#define K12_SRCDESC_EXTRATYPE  0x24   /* uint32, big endian */
-#define K12_SRCDESC_ATM_VPI    0x38   /* uint16, big endian */
-#define K12_SRCDESC_ATM_VCI    0x3a   /* uint16, big endian */
+/* Offsets relative to the beginning of the hardware part */
+#define K12_SRCDESC_HWPARTTYPE 0    /* uint32, big endian */
 
-#define K12_SRCDESC_ATM_AAL    0x3c    /* 1 byte */
-#define K12_SRCDESC_DS0_MASK   0x3c    /* 1 byte */
+#define K12_SRCDESC_DS0_MASK   24   /* variable-length */
 
+#define K12_SRCDESC_ATM_VPI    20   /* uint16, big endian */
+#define K12_SRCDESC_ATM_VCI    22   /* uint16, big endian */
+#define K12_SRCDESC_ATM_AAL    24   /* 1 byte */
+
+/*
+ * A "stack file", as appears in a K12_REC_STK_FILE record, is a text
+ * file (with CR-LF line endings) with a sequence of lines, each of
+ * which begins with a keyword, and has white-space-separated tokens
+ * after that.
+ *
+ * They appear to be:
+ *
+ *   STKVER, which is followed by a number (presumably a version number
+ *   for the stack file format)
+ *
+ *   STACK, which is followed by a quoted string ("ProtocolStack" in one
+ *   file) and two numbers
+ *
+ *   PATH, which is followed by a non-quoted string giving the pathname
+ *   of the directory containing the stack file
+ *
+ *   HLAYER, which is followed by a quoted string, a path for something
+ *   (protocol module?), a keyword ("LOADED", in one file), and a
+ *   quoted string giving a description - this is probably a protocol
+ *   layer of some sort
+ *
+ *   LAYER, which has a similar syntax to HLAYER - the first quoted
+ *   string is a protocol name
+ *
+ *   RELATION, which has a quoted string giving a protocol name,
+ *   another quoted string giving a protocol name, and a condition
+ *   specifier of some sort, which probably says the second protocol
+ *   is layered atop the first protocol if the condition is true.
+ *   The first protocol can also be "BASE", which means that the
+ *   second protocol is the lowest-level protocol.
+ *   The conditions are:
+ *
+ *     CPLX, which may mean "complex" - it has parenthesized expressions
+ *     including "&", presumably a boolean AND, with the individual
+ *     tests being L:expr, where L is a letter such as "L", "D", or "P",
+ *     and expr is:
+ *
+ *        0x........ for L, where each . is a hex digit or a ?, presumably
+ *        meaning "don't care"
+ *
+ *        0;0{=,!=}0b........ for D, where . is presumably a bit or a ?
+ *
+ *        param=value for P, where param is something such as "src_port"
+ *        and value is a value, presumably to test, for example, TCP or
+ *        UDP ports
+ *
+ *     UNCOND, presumably meaning "always"
+ *
+ *     PARAM, followed by a parameter name (as with P:) and a value,
+ *     possibly followed by LAYPARAM and a hex value
+ *
+ *   DECKRNL, followed by a quoted string protocol name, un-quoted
+ *   "LSBF" or "MSBF" (Least/Most Significant Byte First?), and
+ *   an un-quoted string ending with _DK
+ *
+ *   LAYPARAM, followed by a quoted protocol name and a number (-2147221504
+ *   in one file, which is 0x80040000)
+ *
+ *   SPC_CONF, folloed by a number, a quoted string with numbers separated
+ *   by hyphens, and another number
+ *
+ *   CIC_CONF, with a similar syntax to SPC_CONF
+ *
+ *   LAYPOS, followed by a protocol name or "BASE" and 3 numbers.
+ *
+ * Most of this is probably not useful, but the RELATION lines with
+ * "BASE" could be used to figure out how to start the dissection
+ * (if we knew what "L" and "D" did), and *some* of the others might
+ * be useful if they don't match what's already in various dissector
+ * tables (the ones for IP and a higher-level protocol, for example,
+ * aren't very useful, as those are standardized, but the ones for
+ * TCP, UDP, and SCTP ports, and SCTP PPIs, might be useful).
+ */
 
 /*
  * get_record: Get the next record into a buffer
- *   Every about 0x2000 bytes 0x10 bytes are inserted in the file,
+ *   Every 8192 bytes 16 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)
+ *   This reads the next record without the eventual 16 bytes.
+ *   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 8191 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* writep;
-       
-       /* 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"));            
-            return 0;
-        } else if ( read < 0x14 ){
-            K12_DBG(1,("get_record: SHORT READ"));
-            return -1;
+static gint get_record(k12_t *file_data, FILE_T fh, gint64 file_offset,
+                       gboolean is_random, int *err, gchar **err_info) {
+    guint8 *buffer = is_random ? file_data->rand_read_buff : file_data->seq_read_buff;
+    guint buffer_len = is_random ? file_data->rand_read_buff_len : file_data->seq_read_buff_len;
+    guint total_read = 0;
+    guint left;
+    guint8* writep;
+#ifdef DEBUG_K12
+    guint actual_len;
+#endif
+
+    /*
+     * Where the next unknown 16 bytes are stuffed to the file.
+     * Following the file header, they appear every 8192 bytes,
+     * starting right after the file header, so if the file offset
+     * relative to the file header is a multiple of 8192, the
+     * 16-byte blob is there.
+     */
+    guint junky_offset = 8192 - (gint) ( (file_offset - K12_FILE_HDR_LEN) % 8192 );
+
+    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 = (guint8*)g_malloc(8192);
+        buffer_len = 8192;
+        if (is_random) {
+            file_data->rand_read_buff = buffer;
+            file_data->rand_read_buff_len = buffer_len;
+        } else {
+            file_data->seq_read_buff = buffer;
+            file_data->seq_read_buff_len = buffer_len;
         }
-               
-               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) {
-            K12_DBG(1,("get_record: EOF"));
-            return 0;
-        } else if ( read != 0x4 ) {
-            K12_DBG(1,("get_record: SHORT READ"));
+    }
+
+    if ( junky_offset == 8192 ) {
+        /*
+         * We're at the beginning of one of the 16-byte blobs,
+         * so we first need to skip the blob.
+         *
+         * XXX - what if the blob is in the middle of the record
+         * length?  If the record length is always a multiple of
+         * 4 bytes, that won't happen.
+         */
+        if ( ! file_skip( fh, K12_FILE_BLOB_LEN, err ) )
             return -1;
+        total_read += K12_FILE_BLOB_LEN;
+    }
+
+    /*
+     * Read the record length.
+     */
+    if ( !wtap_read_bytes( fh, buffer, 4, err, err_info ) )
+        return -1;
+    total_read += 4;
+
+    left = pntoh32(buffer + K12_RECORD_LEN);
+#ifdef DEBUG_K12
+    actual_len = left;
+#endif
+    junky_offset -= 4;
+
+    K12_DBG(5,("get_record: GET length=%u",left));
+
+    /*
+     * Record length must be at least large enough for the length
+     * and type, hence 8 bytes.
+     *
+     * XXX - is WTAP_MAX_PACKET_SIZE the right check for a maximum
+     * record size?  Should we report this error differently?
+     */
+    if (left < 8) {
+        *err = WTAP_ERR_BAD_FILE;
+        *err_info = g_strdup_printf("k12: Record length %u is less than 8 bytes long",left);
+        return -1;
+    }
+    if (left > WTAP_MAX_PACKET_SIZE) {
+        *err = WTAP_ERR_BAD_FILE;
+        *err_info = g_strdup_printf("k12: Record length %u is greater than the maximum %u",left,WTAP_MAX_PACKET_SIZE);
+        return -1;
+    }
+
+    /*
+     * XXX - calculate the lowest power of 2 >= left, rather than just
+     * looping.
+     */
+    while (left > buffer_len) {
+        buffer = (guint8*)g_realloc(buffer,buffer_len*=2);
+        if (is_random) {
+            file_data->rand_read_buff = buffer;
+            file_data->rand_read_buff_len = buffer_len;
+        } else {
+            file_data->seq_read_buff = buffer;
+            file_data->seq_read_buff_len = buffer_len;
         }
-       }
-       
-       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);
-       
-       writep = 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(writep,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(writep,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;
-                       }
-                       
-                       writep += 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;
+    }
+
+    writep = buffer + 4;
+    left -= 4;
+
+    /* Read the rest of the record. */
+    do {
+        K12_DBG(6,("get_record: looping left=%d junky_offset=%" G_GINT64_MODIFIER "d",left,junky_offset));
+
+        if (junky_offset > left) {
+            /*
+             * The next 16-byte blob is past the end of this record.
+             * Just read the rest of the record.
+             */
+            if ( !wtap_read_bytes( fh, writep, left, err, err_info ) )
+                return -1;
+            total_read += left;
+            break;
+        } else {
+            /*
+             * The next 16-byte blob is part of this record.
+             * Read up to the blob.
+             */
+            if ( !wtap_read_bytes( fh, writep, junky_offset, err, err_info ) )
+                return -1;
+
+            total_read += junky_offset;
+            writep += junky_offset;
+
+            /*
+             * Skip the blob.
+             */
+            if ( !file_skip( fh, K12_FILE_BLOB_LEN, err ) )
+                return -1;
+            total_read += K12_FILE_BLOB_LEN;
+
+            left -= junky_offset;
+            junky_offset = 8192;
+        }
+
+    } while(left);
+
+    K12_HEX_ASCII_DUMP(5,file_offset, "GOT record", buffer, actual_len);
+    return total_read;
 }
 
-static gboolean k12_read(wtap *wth, int *err, gchar **err_info _U_, gint64 *data_offset) {
-    k12_src_desc_t* src_desc;
-    guint8* buffer = NULL;
-    gint64 offset;
-    long len;
+static gboolean
+memiszero(const void *ptr, size_t count)
+{
+    const guint8 *p = (const guint8 *)ptr;
+
+    while (count != 0) {
+        if (*p != 0)
+            return FALSE;
+        p++;
+        count--;
+    }
+    return TRUE;
+}
+
+static void
+process_packet_data(struct wtap_pkthdr *phdr, Buffer *target, guint8 *buffer,
+                    gint len, k12_t *k12)
+{
     guint32 type;
-       guint32 src_id;
+    guint   buffer_offset;
     guint64 ts;
+    guint32 length;
     guint32 extra_len;
-    
-    offset = wth->data_offset;
-    
-    /* ignore the record if it isn't a packet */    
+    guint32 src_id;
+    k12_src_desc_t* src_desc;
+
+    phdr->rec_type = REC_TYPE_PACKET;
+    phdr->presence_flags = WTAP_HAS_TS;
+
+    ts = pntoh64(buffer + K12_PACKET_TIMESTAMP);
+
+    phdr->ts.secs = (guint32) ((ts / 2000000) + 631152000);
+    phdr->ts.nsecs = (guint32) ( (ts % 2000000) * 500 );
+
+    length = pntoh32(buffer + K12_RECORD_FRAME_LEN) & 0x00001FFF;
+    phdr->len = phdr->caplen = length;
+
+    type = pntoh32(buffer + K12_RECORD_TYPE);
+    buffer_offset = (type == K12_REC_D0020) ? K12_PACKET_FRAME_D0020 : K12_PACKET_FRAME;
+
+    ws_buffer_assure_space(target, length);
+    memcpy(ws_buffer_start_ptr(target), buffer + buffer_offset, length);
+
+    /* extra information need by some protocols */
+    extra_len = len - buffer_offset - length;
+    ws_buffer_assure_space(&(k12->extra_info), extra_len);
+    memcpy(ws_buffer_start_ptr(&(k12->extra_info)),
+           buffer + buffer_offset + length, extra_len);
+    phdr->pseudo_header.k12.extra_info = (guint8*)ws_buffer_start_ptr(&(k12->extra_info));
+    phdr->pseudo_header.k12.extra_length = extra_len;
+
+    src_id = pntoh32(buffer + K12_RECORD_SRC_ID);
+    K12_DBG(5,("process_packet_data: src_id=%.8x",src_id));
+    phdr->pseudo_header.k12.input = src_id;
+
+    if ( ! (src_desc = (k12_src_desc_t*)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 = (k12_src_desc_t*)g_hash_table_lookup(k12->src_by_id,GUINT_TO_POINTER(src_id&K12_RECORD_SRC_ID_MASK));
+    }
+
+    if (src_desc) {
+        K12_DBG(5,("process_packet_data: input_name='%s' stack_file='%s' type=%x",src_desc->input_name,src_desc->stack_file,src_desc->input_type));
+        phdr->pseudo_header.k12.input_name = src_desc->input_name;
+        phdr->pseudo_header.k12.stack_file = src_desc->stack_file;
+        phdr->pseudo_header.k12.input_type = src_desc->input_type;
+
+        switch(src_desc->input_type) {
+            case K12_PORT_ATMPVC:
+                if ((long)(buffer_offset + length + K12_PACKET_OFFSET_CID) < len) {
+                    phdr->pseudo_header.k12.input_info.atm.vp =  pntoh16(buffer + buffer_offset + length + K12_PACKET_OFFSET_VP);
+                    phdr->pseudo_header.k12.input_info.atm.vc =  pntoh16(buffer + buffer_offset + length + K12_PACKET_OFFSET_VC);
+                    phdr->pseudo_header.k12.input_info.atm.cid =  *((unsigned char*)(buffer + buffer_offset + length + K12_PACKET_OFFSET_CID));
+                    break;
+                }
+                /* Fall through */
+            default:
+                memcpy(&(phdr->pseudo_header.k12.input_info),&(src_desc->input_info),sizeof(src_desc->input_info));
+                break;
+        }
+    } else {
+        K12_DBG(5,("process_packet_data: NO SRC_RECORD FOUND"));
+
+        memset(&(phdr->pseudo_header.k12),0,sizeof(phdr->pseudo_header.k12));
+        phdr->pseudo_header.k12.input_name = "unknown port";
+        phdr->pseudo_header.k12.stack_file = "unknown stack file";
+    }
+
+    phdr->pseudo_header.k12.input = src_id;
+    phdr->pseudo_header.k12.stuff = k12;
+}
+
+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;
+    gint64 offset;
+    gint len;
+    guint32 type;
+    guint32 src_id;
+
+    offset = file_tell(wth->fh);
+
+    /* ignore the record if it isn't a packet */
     do {
-               K12_DBG(5,("k12_read: offset=%i",offset));
-               
+        if ( k12->num_of_records == 0 ) {
+            /* No more records */
+            *err = 0;
+            return FALSE;
+        }
+
+        K12_DBG(5,("k12_read: offset=%i",offset));
+
         *data_offset = offset;
-        
-        len = get_record(&buffer, wth->fh, offset);
-        
+
+        len = get_record(k12, wth->fh, offset, FALSE, err, err_info);
+
         if (len < 0) {
-            *err = WTAP_ERR_SHORT_READ;
+            /* read error */
             return FALSE;
         } else if (len == 0) {
-            *err = 0;
+            /* EOF */
+            *err = WTAP_ERR_SHORT_READ;
             return FALSE;
+        } else if (len < K12_RECORD_SRC_ID + 4) {
+            /* Record not large enough to contain a src ID */
+            *err = WTAP_ERR_BAD_FILE;
+            *err_info = g_strdup_printf("data record length %d too short", len);
+            return FALSE;
+        }
+        k12->num_of_records--;
+
+        buffer = k12->seq_read_buff;
+
+        type = pntoh32(buffer + K12_RECORD_TYPE);
+        src_id = pntoh32(buffer + K12_RECORD_SRC_ID);
+
+
+        if ( ! (src_desc = (k12_src_desc_t*)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 = (k12_src_desc_t*)g_hash_table_lookup(k12->src_by_id,GUINT_TO_POINTER(src_id&K12_RECORD_SRC_ID_MASK));
         }
-        
-        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));
 
         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;
-    
-    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 + 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_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));
-            break;
-            
-        }
-    } else {
-        K12_DBG(5,("k12_read: NO RECORD FOUND"));
 
-        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;
-    
+    } while ( ((type & K12_MASK_PACKET) != K12_REC_PACKET && (type & K12_MASK_PACKET) != K12_REC_D0020) || !src_id || !src_desc );
+
+    process_packet_data(&wth->phdr, wth->frame_buffer, buffer, len, 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_) {
-    k12_src_desc_t* src_desc;
+static gboolean k12_seek_read(wtap *wth, gint64 seek_off, struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info) {
+    k12_t *k12 = (k12_t *)wth->priv;
     guint8* buffer;
-    long len;
-    guint32 extra_len;
-    guint32 input;
-    
+    gint len;
+
     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(k12, wth->random_fh, seek_off, TRUE, err, err_info);
+    if (len < 0) {
         K12_DBG(5,("k12_seek_read: READ ERROR"));
         return FALSE;
+    } else if (len < K12_RECORD_SRC_ID + 4) {
+        /* Record not large enough to contain a src ID */
+        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 + 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_length = extra_len;
-    if (pseudo_header) {
-        pseudo_header->k12.extra_info = (void*)buffer_start_ptr(&(wth->capture.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) {
-        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) {
-                pseudo_header->k12.input_info.atm.vp =  pntohs(buffer + K12_PACKET_FRAME + length + K12_PACKET_OFFSET_VP);
-                pseudo_header->k12.input_info.atm.vc =  pntohs(buffer + K12_PACKET_FRAME + length + K12_PACKET_OFFSET_VC);
-                pseudo_header->k12.input_info.atm.cid =  *((unsigned char*)(buffer + K12_PACKET_FRAME + length + K12_PACKET_OFFSET_CID));
-                break;
-                }
-                /* Fall through */
-            default:
-                memcpy(&(pseudo_header->k12.input_info),&(src_desc->input_info),sizeof(src_desc->input_info));
-                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) {
-                wth->pseudo_header.k12.input_info.atm.vp =  pntohs(buffer + K12_PACKET_FRAME + length + K12_PACKET_OFFSET_VP);
-                wth->pseudo_header.k12.input_info.atm.vc =  pntohs(buffer + K12_PACKET_FRAME + length + K12_PACKET_OFFSET_VC);
-                wth->pseudo_header.k12.input_info.atm.cid =  *((unsigned char*)(buffer + K12_PACKET_FRAME + length + K12_PACKET_OFFSET_CID));
-            }
-            break;
-            /* Fall through */
-            default:
-            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"));
 
-        if (pseudo_header) {
-            memset(&(pseudo_header->k12),0,sizeof(pseudo_header->k12));
-            pseudo_header->k12.input_name = "unknown port";
-            pseudo_header->k12.stack_file = "unknown stack file";
-        }
+    buffer = k12->rand_read_buff;
 
-        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;
-    }
-    
-    wth->pseudo_header.k12.input = input;
-    wth->pseudo_header.k12.stuff = wth->capture.k12;
+    process_packet_data(phdr, buf, buffer, len, k12);
 
     K12_DBG(5,("k12_seek_read: DONE OK"));
 
@@ -504,43 +758,48 @@ static gboolean k12_seek_read(wtap *wth, gint64 seek_off, union wtap_pseudo_head
 }
 
 
-static k12_t* new_k12_file_data() {
-    k12_t* fd = g_malloc(sizeof(k12_t));
-    
+static k12_t* new_k12_file_data(void) {
+    k12_t* fd = g_new(k12_t,1);
+
     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);
+    fd->seq_read_buff = NULL;
+    fd->seq_read_buff_len = 0;
+    fd->rand_read_buff = NULL;
+    fd->rand_read_buff_len = 0;
+
+    ws_buffer_init(&(fd->extra_info), 100);
 
-    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);
-    
+    k12_src_desc_t* rec = (k12_src_desc_t*)v;
+
+    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));
+    ws_buffer_free(&(fd->extra_info));
+    g_free(fd->seq_read_buff);
+    g_free(fd->rand_read_buff);
     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);
@@ -548,233 +807,389 @@ static void k12_close(wtap *wth) {
 }
 
 
-int k12_open(wtap *wth, int *err, gchar **err_info _U_) {
+wtap_open_return_val k12_open(wtap *wth, int *err, gchar **err_info) {
     k12_src_desc_t* rec;
-    guint8 header_buffer[0x200];
+    guint8 header_buffer[K12_FILE_HDR_LEN];
     guint8* read_buffer;
     guint32 type;
     long offset;
     long len;
+    guint port_type;
     guint32 rec_len;
-    guint32 extra_len;
+    guint32 hwpart_len;
     guint32 name_len;
     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");
-    else dbg_out = stderr;
-    if ( env_level ) debug_level = strtoul(env_level,NULL,10);
+    if ( env_file ) {
+        dbg_out = ws_fopen(env_file,"w");
+        if (dbg_out == NULL) {
+                dbg_out = stderr;
+                K12_DBG(1,("unable to open K12 DEBUG FILENAME for writing!  Logging to standard error"));
+        }
+    }
+    else
+        dbg_out = stderr;
+    if ( env_level ) debug_level = (unsigned int)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"));
-        return 0;
-    } else {
-        if ( memcmp(header_buffer,k12_file_magic,8) != 0 ) {
-            K12_DBG(1,("k12_open: BAD MAGIC"));
-            return 0;
+
+    if ( !wtap_read_bytes(wth->fh,header_buffer,K12_FILE_HDR_LEN,err,err_info) ) {
+        K12_DBG(1,("k12_open: FILE HEADER TOO SHORT OR READ ERROR"));
+        if (*err != WTAP_ERR_SHORT_READ) {
+            return WTAP_OPEN_ERROR;
         }
+        return WTAP_OPEN_NOT_MINE;
+    }
+
+    if ( memcmp(header_buffer,k12_file_magic,8) != 0 ) {
+        K12_DBG(1,("k12_open: BAD MAGIC"));
+        return WTAP_OPEN_NOT_MINE;
     }
-    
-    offset = 0x200;
-    
+
+    offset = K12_FILE_HDR_LEN;
+
     file_data = new_k12_file_data();
-    
-    file_data->file_len = pntohl( header_buffer + 0x8);
-    file_data->num_of_records = pntohl( header_buffer + 0xC );
-    
+
+    file_data->file_len = pntoh32( header_buffer + 0x8);
+    if (memiszero(header_buffer + 0x10, K12_FILE_HDR_LEN - 0x10)) {
+        /*
+         * The rest of the file header is all zeroes.  That means
+         * this is a file written by the old Wireshark code, and
+         * a count of records in the file is at an offset of 0x0C.
+         */
+        file_data->num_of_records = pntoh32( header_buffer + 0x0C );
+    } else {
+        /*
+         * There's at least one non-zero byte in the rest of the
+         * header.  The value 8192 is at 0xC (page size?), and
+         * what appears to be the number of records in the file
+         * is at an offset of 0x24 and at an offset of 0x2c.
+         *
+         * If the two values are not the same, we fail; if that's
+         * the case, we need to see the file to figure out which
+         * of those two values, if any, is the count.
+         */
+        file_data->num_of_records = pntoh32( header_buffer + K12_FILE_HDR_RECORD_COUNT_1 );
+        if ( file_data->num_of_records != pntoh32( header_buffer + K12_FILE_HDR_RECORD_COUNT_2 ) ) {
+            *err = WTAP_ERR_BAD_FILE;
+            *err_info = g_strdup_printf("k12: two different record counts, %u at 0x%02x and %u at 0x%02x",
+                                        file_data->num_of_records,
+                                        K12_FILE_HDR_RECORD_COUNT_1,
+                                        pntoh32( header_buffer + K12_FILE_HDR_RECORD_COUNT_2 ),
+                                        K12_FILE_HDR_RECORD_COUNT_2 );
+            return WTAP_OPEN_ERROR;
+        }
+    }
+
     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 ) {
+        if ( file_data->num_of_records == 0 ) {
+            *err = WTAP_ERR_SHORT_READ;
+            destroy_k12_file_data(file_data);
+            return WTAP_OPEN_ERROR;
+        }
+
+        len = get_record(file_data, wth->fh, offset, FALSE, err, err_info);
+
+        if ( len < 0 ) {
             K12_DBG(1,("k12_open: BAD HEADER RECORD",len));
-            return -1;
+            destroy_k12_file_data(file_data);
+            return WTAP_OPEN_ERROR;
+        }
+        if ( len == 0 ) {
+            K12_DBG(1,("k12_open: BAD HEADER RECORD",len));
+            *err = WTAP_ERR_SHORT_READ;
+            destroy_k12_file_data(file_data);
+            return WTAP_OPEN_ERROR;
+        }
+
+        read_buffer = file_data->seq_read_buff;
+
+        rec_len = pntoh32( read_buffer + K12_RECORD_LEN );
+        if (rec_len < K12_RECORD_TYPE + 4) {
+            /* Record isn't long enough to have a type field */
+            *err = WTAP_ERR_BAD_FILE;
+            *err_info = g_strdup_printf("k12_open: record length %u < %u",
+                                        rec_len, K12_RECORD_TYPE + 4);
+            return WTAP_OPEN_ERROR;
         }
-        
-        
-        type = pntohl( read_buffer + K12_RECORD_TYPE );
-        
-        if ( (type & K12_MASK_PACKET) == K12_REC_PACKET) {
+        type = pntoh32( read_buffer + K12_RECORD_TYPE );
+
+        if ( (type & K12_MASK_PACKET) == K12_REC_PACKET ||
+             (type & K12_MASK_PACKET) == K12_REC_D0020) {
             /*
              * 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);
-                return -1;
+                return WTAP_OPEN_ERROR;
             }
             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 );
-            
+        }
+
+        switch (type) {
+
+        case K12_REC_SRCDSC:
+        case K12_REC_SRCDSC2:
+            rec = g_new0(k12_src_desc_t,1);
+
+            if (rec_len < K12_SRCDESC_HWPART) {
+                /*
+                 * Record isn't long enough to have the fixed-length portion
+                 * of the source descriptor field.
+                 */
+                *err = WTAP_ERR_BAD_FILE;
+                *err_info = g_strdup_printf("k12_open: source descriptor record length %u < %u",
+                                            rec_len, K12_SRCDESC_HWPART);
+                destroy_k12_file_data(file_data);
+                g_free(rec);
+                return WTAP_OPEN_ERROR;
+            }
+            port_type = read_buffer[K12_SRCDESC_PORT_TYPE];
+            hwpart_len = pntoh16( read_buffer + K12_SRCDESC_HWPARTLEN );
+            name_len = pntoh16( read_buffer + K12_SRCDESC_NAMELEN );
+            stack_len = pntoh16( read_buffer + K12_SRCDESC_STACKLEN );
+
+            rec->input = pntoh32( 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 ) {
+
+            if (name_len == 0) {
+                K12_DBG(5,("k12_open: failed (name_len == 0 in source description"));
+                destroy_k12_file_data(file_data);
+                g_free(rec);
+                return WTAP_OPEN_NOT_MINE;
+            }
+            if (stack_len == 0) {
+                K12_DBG(5,("k12_open: failed (stack_len == 0 in source description"));
+                destroy_k12_file_data(file_data);
+                g_free(rec);
+                return WTAP_OPEN_NOT_MINE;
+            }
+            if (rec_len < K12_SRCDESC_HWPART + hwpart_len + name_len + stack_len) {
+                /*
+                 * Record isn't long enough to have the full source descriptor
+                 * field, including the variable-length parts.
+                 */
+                *err = WTAP_ERR_BAD_FILE;
+                *err_info = g_strdup_printf("k12_open: source descriptor record length %u < %u (%u + %u + %u + %u)",
+                                            rec_len,
+                                            K12_SRCDESC_HWPART + hwpart_len + name_len + stack_len,
+                                            K12_SRCDESC_HWPART, hwpart_len, name_len, stack_len);
+                destroy_k12_file_data(file_data);
                 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"));
-                return 0;
+                return WTAP_OPEN_ERROR;
             }
 
-            if (extra_len)
-                switch(( rec->input_type = pntohl( read_buffer + K12_SRCDESC_EXTRATYPE ) )) {
+            if (hwpart_len) {
+                if (hwpart_len < 4) {
+                    /* Hardware part isn't long enough to have a type field */
+                    *err = WTAP_ERR_BAD_FILE;
+                    *err_info = g_strdup_printf("k12_open: source descriptor hardware part length %u < 4",
+                                                hwpart_len);
+                    destroy_k12_file_data(file_data);
+                    g_free(rec);
+                    return WTAP_OPEN_ERROR;
+                }
+                switch(( rec->input_type = pntoh32( read_buffer + K12_SRCDESC_HWPART + K12_SRCDESC_HWPARTTYPE ) )) {
                     case K12_PORT_DS0S:
+                        /* This appears to be variable-length */
                         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; 
+                        if (hwpart_len > K12_SRCDESC_DS0_MASK) {
+                            for (i = 0; i < hwpart_len - K12_SRCDESC_DS0_MASK; i++) {
+                                rec->input_info.ds0mask |= ( *(read_buffer + K12_SRCDESC_HWPART + K12_SRCDESC_DS0_MASK + i) == 0xff ) ? 1U<<(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 );
+                        if (hwpart_len < K12_SRCDESC_ATM_VCI + 2) {
+                            /* Hardware part isn't long enough to have ATM information */
+                            *err = WTAP_ERR_BAD_FILE;
+                            *err_info = g_strdup_printf("k12_open: source descriptor hardware part length %u < %u",
+                                                        hwpart_len,
+                                                        K12_SRCDESC_ATM_VCI + 2);
+                            destroy_k12_file_data(file_data);
+                            g_free(rec);
+                            return WTAP_OPEN_ERROR;
+                        }
+
+                        rec->input_info.atm.vp = pntoh16( read_buffer + K12_SRCDESC_HWPART + K12_SRCDESC_ATM_VPI );
+                        rec->input_info.atm.vc = pntoh16( read_buffer + K12_SRCDESC_HWPART + K12_SRCDESC_ATM_VCI );
                         break;
                     default:
                         break;
                 }
-            else {    /* Record viewer generated files
-                   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, 
+            } else {
+                /* Record viewer generated files don't have this information */
+                if (port_type >= 0x14
+                    && port_type <= 0x17) {
+                    /* For ATM2_E1DS1, ATM2_E3DS3,
                        ATM2_STM1EL and ATM2_STM1OP */
                     rec->input_type = K12_PORT_ATMPVC;
+                    rec->input_info.atm.vp = 0;
+                    rec->input_info.atm.vc = 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);
-            
+            if (read_buffer[K12_SRCDESC_HWPART + hwpart_len + name_len - 1] != '\0') {
+                *err = WTAP_ERR_BAD_FILE;
+                *err_info = g_strdup("k12_open: source descriptor record contains non-null-terminated link-layer name");
+                destroy_k12_file_data(file_data);
+                g_free(rec);
+                return WTAP_OPEN_ERROR;
+            }
+            if (read_buffer[K12_SRCDESC_HWPART + hwpart_len + name_len + stack_len - 1] != '\0') {
+                *err = WTAP_ERR_BAD_FILE;
+                *err_info = g_strdup("k12_open: source descriptor record contains non-null-terminated stack path");
+                destroy_k12_file_data(file_data);
+                g_free(rec);
+                return WTAP_OPEN_ERROR;
+            }
+            rec->input_name = (gchar *)g_memdup(read_buffer + K12_SRCDESC_HWPART + hwpart_len, name_len);
+            rec->stack_file = (gchar *)g_memdup(read_buffer + K12_SRCDESC_HWPART + hwpart_len + name_len, stack_len);
+
+            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 {
-            offset += len;
-            continue;
+            break;
+
+        case K12_REC_STK_FILE:
+            K12_DBG(1,("k12_open: K12_REC_STK_FILE"));
+            K12_DBG(1,("Field 1: 0x%08x",pntoh32( read_buffer + 0x08 )));
+            K12_DBG(1,("Field 2: 0x%08x",pntoh32( read_buffer + 0x0c )));
+            K12_ASCII_DUMP(1, read_buffer, rec_len, 16);
+            break;
+
+        default:
+            K12_DBG(1,("k12_open: RECORD TYPE 0x%08x",type));
+            break;
         }
+        offset += len;
+        file_data->num_of_records--;
     } while(1);
-    
-    wth->data_offset = offset;
-    wth->file_type = WTAP_FILE_K12;
+
+    wth->file_type_subtype = WTAP_FILE_TYPE_SUBTYPE_K12;
     wth->file_encap = WTAP_ENCAP_K12;
     wth->snapshot_length = 0;
     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->file_tsprec = WTAP_TSPREC_NSEC;
 
-    return 1;
+    return WTAP_OPEN_MINE;
 }
 
+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 WTAP_ERR_UNWRITABLE_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 = (8192 - ( (k12->file_offset - K12_FILE_HDR_LEN) % 8192 )) % 8192;
+
     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, K12_FILE_BLOB_LEN, err_p))
+            return FALSE;
+
+        if (! wtap_dump_file_write(wdh, buffer+junky_offset, len - junky_offset, err_p))
+            return FALSE;
+
+        k12->file_offset += len + K12_FILE_BLOB_LEN;
+        k12->file_len += len + K12_FILE_BLOB_LEN;
     } 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;
+        k12->file_len += 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) {
-    k12_src_desc_t* src_desc = v;
-    wtap_dumper *wdh = p;
+    k12_src_desc_t* src_desc = (k12_src_desc_t*)v;
+    wtap_dumper *wdh = (wtap_dumper *)p;
     guint32 len;
     guint offset;
     guint i;
-    
+    int   errxxx; /* dummy */
+
     union {
-        guint8 buffer[0x2000];
-        
+        guint8 buffer[8192];
+
         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 hwpart_len;
+
             guint16 name_len;
             guint16 stack_len;
-            
+
             struct {
                 guint32 type;
-                
+
                 union {
                     struct {
                         guint32 unk32;
                         guint8 mask[32];
                     } ds0mask;
-                    
+
                     struct {
-                        guint8 unk_data[0x10];
+                        guint8 unk_data[16];
                         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);
@@ -785,151 +1200,186 @@ 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);
+            obj.record.hwpart_len = g_htons(0x18);
             obj.record.extra.desc.atm.vp = g_htons(src_desc->input_info.atm.vp);
             obj.record.extra.desc.atm.vc = g_htons(src_desc->input_info.atm.vc);
             offset = 0x3c;
             break;
         case K12_PORT_DS0S:
-            obj.record.extra_len = g_htons(0x18);
+            obj.record.hwpart_len = g_htons(0x18);
             for( i=0; i<32; i++ ) {
                 obj.record.extra.desc.ds0mask.mask[i] =
                 (src_desc->input_info.ds0mask & (1 << i)) ? 0xff : 0x00;
             }
-                offset = 0x3c;
+            offset = 0x3c;
             break;
         default:
-            obj.record.extra_len = g_htons(0x08);
+            obj.record.hwpart_len = g_htons(0x08);
             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, gchar **err_info _U_) {
+    const union wtap_pseudo_header *pseudo_header = &phdr->pseudo_header;
+    k12_dump_t *k12 = (k12_dump_t *)wdh->priv;
+    guint32 len;
     union {
-        guint8 buffer[0x2000];
+        guint8 buffer[8192];
         struct {
             guint32 len;
             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) {
-        k12_t* file_data = pseudo_header->k12.stuff;
+
+    /* We can only write packet records. */
+    if (phdr->rec_type != REC_TYPE_PACKET) {
+        *err = WTAP_ERR_UNWRITABLE_REC_TYPE;
+        return FALSE;
+    }
+
+    if (k12->num_of_records == 0) {
+        k12_t* file_data = (k12_t*)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 = 0x20 + phdr->caplen;
     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.frame_len = g_htonl(phdr->caplen);
     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;
+
+    memcpy(obj.record.frame,pd,phdr->caplen);
+
+    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) {
+static gboolean k12_dump_finish(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 (fseek(wdh->fh, 8, SEEK_SET) == -1) {
-        *err = errno;
+
+    if (! wtap_dump_file_write(wdh, k12_eof, 2, err))
         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);
-    
+    k12->file_len += 2;
+
+    if (wtap_dump_file_seek(wdh, K12_FILE_HDR_FILE_SIZE, SEEK_SET, err) == -1)
+        return FALSE;
+
+    d.u = g_htonl(k12->file_len);
+
+    if (! wtap_dump_file_write(wdh, d.b, 4, err))
+        return FALSE;
+
+    if (wtap_dump_file_seek(wdh, K12_FILE_HDR_PAGE_SIZE, SEEK_SET, err) == -1)
+        return FALSE;
+
+    d.u = g_htonl(8192);
+
+    if (! wtap_dump_file_write(wdh, d.b, 4, err))
+        return FALSE;
+
+    if (wtap_dump_file_seek(wdh, K12_FILE_HDR_RECORD_COUNT_1, SEEK_SET, err) == -1)
+        return FALSE;
+
+    d.u = g_htonl(k12->num_of_records);
+
+    if (! wtap_dump_file_write(wdh, d.b, 4, err))
+        return FALSE;
+
+    if (wtap_dump_file_seek(wdh, K12_FILE_HDR_RECORD_COUNT_2, SEEK_SET, err) == -1)
+        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;
+
+    if (wtap_dump_file_seek(wdh, K12_FILE_HDR_LEN, SEEK_SET, err) == -1)
         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;
-    
+    wdh->subtype_finish = k12_dump_finish;
+
+    k12 = (k12_dump_t *)g_malloc(sizeof(k12_dump_t));
+    wdh->priv = (void *)k12;
+    k12->file_len = K12_FILE_HDR_LEN;
+    k12->num_of_records = 0;
+    k12->file_offset  = K12_FILE_HDR_LEN;
+
     return TRUE;
 }
 
-
+/*
+ * Editor modelines  -  http://www.wireshark.org/tools/modelines.html
+ *
+ * Local variables:
+ * c-basic-offset: 4
+ * tab-width: 8
+ * indent-tabs-mode: nil
+ * End:
+ *
+ * vi: set shiftwidth=4 tabstop=8 expandtab:
+ * :indentSize=4:tabSize=8:noTabs=true:
+ */