No seek-read routines use the length argument, so eliminate it from

wtap_seek_read().

svn path=/trunk/; revision=54570

50 files changed, 93 insertions, 149 deletions

diff --git a/wiretap/5views.c b/wiretap/5views.c
index 48d0c7a750..5ff61101dc 100644
--- a/wiretap/5views.c
+++ b/wiretap/5views.c
@@ -104,8 +104,7 @@ typedef struct
 static gboolean _5views_read(wtap *wth, int *err, gchar **err_info,
     gint64 *data_offset);
 static gboolean _5views_seek_read(wtap *wth, gint64 seek_off,
-    struct wtap_pkthdr *phdr, Buffer *buf, int length,
-    int *err, gchar **err_info);
+    struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info);
 static int _5views_read_header(wtap *wth, FILE_T fh, t_5VW_TimeStamped_Header *hdr,
     struct wtap_pkthdr *phdr, int *err, gchar **err_info);
 
@@ -243,7 +242,7 @@ _5views_read(wtap *wth, int *err, gchar **err_info, gint64 *data_offset)
 
 static gboolean
 _5views_seek_read(wtap *wth, gint64 seek_off, struct wtap_pkthdr *phdr,
-    Buffer *buf, int length _U_, int *err, gchar **err_info)
+    Buffer *buf, int *err, gchar **err_info)
 {
 	t_5VW_TimeStamped_Header TimeStamped_Header;
 
diff --git a/wiretap/aethra.c b/wiretap/aethra.c
index 3f7dc450bd..c684014706 100644
--- a/wiretap/aethra.c
+++ b/wiretap/aethra.c
@@ -117,8 +117,7 @@ typedef struct {
 static gboolean aethra_read(wtap *wth, int *err, gchar **err_info,
     gint64 *data_offset);
 static gboolean aethra_seek_read(wtap *wth, gint64 seek_off,
-    struct wtap_pkthdr *phdr, Buffer *buf, int length,
-    int *err, gchar **err_info);
+    struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info);
 static gboolean aethra_read_rec_header(wtap *wth, FILE_T fh, struct aethrarec_hdr *hdr,
     struct wtap_pkthdr *phdr, int *err, gchar **err_info);
 
@@ -278,7 +277,7 @@ found:
 
 static gboolean
 aethra_seek_read(wtap *wth, gint64 seek_off, struct wtap_pkthdr *phdr,
-    Buffer *buf, int length _U_, int *err, gchar **err_info)
+    Buffer *buf, int *err, gchar **err_info)
 {
 	struct aethrarec_hdr hdr;
 
diff --git a/wiretap/ascendtext.c b/wiretap/ascendtext.c
index 5c8636f7da..8a2e4b48ac 100644
--- a/wiretap/ascendtext.c
+++ b/wiretap/ascendtext.c
@@ -79,7 +79,7 @@ static const ascend_magic_string ascend_magic[] = {
 static gboolean ascend_read(wtap *wth, int *err, gchar **err_info,
 	gint64 *data_offset);
 static gboolean ascend_seek_read(wtap *wth, gint64 seek_off,
-	struct wtap_pkthdr *phdr, Buffer *buf, int len,
+	struct wtap_pkthdr *phdr, Buffer *buf,
 	int *err, gchar **err_info);
 
 /* Seeks to the beginning of the next packet, and returns the
@@ -256,7 +256,7 @@ static gboolean ascend_read(wtap *wth, int *err, gchar **err_info,
 }
 
 static gboolean ascend_seek_read(wtap *wth, gint64 seek_off,
-	struct wtap_pkthdr *phdr, Buffer *buf, int len _U_,
+	struct wtap_pkthdr *phdr, Buffer *buf,
 	int *err, gchar **err_info)
 {
   ascend_t *ascend = (ascend_t *)wth->priv;
diff --git a/wiretap/ber.c b/wiretap/ber.c
index 31fe4e1c12..93ae4bac1f 100644
--- a/wiretap/ber.c
+++ b/wiretap/ber.c
@@ -90,7 +90,7 @@ static gboolean ber_read(wtap *wth, int *err, gchar **err_info, gint64 *data_off
 }
 
 static gboolean ber_seek_read(wtap *wth, gint64 seek_off, struct wtap_pkthdr *phdr _U_,
-			      Buffer *buf, int length _U_, int *err, gchar **err_info)
+			      Buffer *buf, int *err, gchar **err_info)
 {
   /* there is only one packet */
   if(seek_off > 0) {
diff --git a/wiretap/btsnoop.c b/wiretap/btsnoop.c
index 1cc9ae897a..69aaf1d108 100644
--- a/wiretap/btsnoop.c
+++ b/wiretap/btsnoop.c
@@ -78,8 +78,7 @@ static const gint64 KUnixTimeBase = G_GINT64_CONSTANT(0x00dcddb30f2f8000); /* of
 static gboolean btsnoop_read(wtap *wth, int *err, gchar **err_info,
     gint64 *data_offset);
 static gboolean btsnoop_seek_read(wtap *wth, gint64 seek_off,
-    struct wtap_pkthdr *phdr, Buffer *buf, int length,
-    int *err, gchar **err_info);
+    struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info);
 static gboolean btsnoop_read_record(wtap *wth, FILE_T fh,
     struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info);
 
@@ -174,8 +173,7 @@ static gboolean btsnoop_read(wtap *wth, int *err, gchar **err_info,
 }
 
 static gboolean btsnoop_seek_read(wtap *wth, gint64 seek_off,
-    struct wtap_pkthdr *phdr, Buffer *buf, int length _U_,
-    int *err, gchar **err_info)
+    struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info)
 {
 	if (file_seek(wth->random_fh, seek_off, SEEK_SET, err) == -1)
 		return FALSE;
diff --git a/wiretap/camins.c b/wiretap/camins.c
index c143567f71..43b30214c9 100644
--- a/wiretap/camins.c
+++ b/wiretap/camins.c
@@ -310,8 +310,7 @@ camins_read(wtap *wth, int *err, gchar **err_info, gint64 *data_offset)
 
 static gboolean
 camins_seek_read(wtap *wth, gint64 seek_off,
-    struct wtap_pkthdr *pkthdr, Buffer *buf, int length _U_,
-    int *err, gchar **err_info)
+    struct wtap_pkthdr *pkthdr, Buffer *buf, int *err, gchar **err_info)
 {
     if (-1 == file_seek(wth->random_fh, seek_off, SEEK_SET, err))
         return FALSE;
diff --git a/wiretap/catapult_dct2000.c b/wiretap/catapult_dct2000.c
index 41fdd3904f..6aca8106a5 100644
--- a/wiretap/catapult_dct2000.c
+++ b/wiretap/catapult_dct2000.c
@@ -109,8 +109,8 @@ static gboolean catapult_dct2000_read(wtap *wth, int *err, gchar **err_info,
                                       gint64 *data_offset);
 static gboolean catapult_dct2000_seek_read(wtap *wth, gint64 seek_off,
                                            struct wtap_pkthdr *phdr,
-                                           Buffer *buf, int length,
-                                           int *err, gchar **err_info);
+                                           Buffer *buf, int *err,
+                                           gchar **err_info);
 static void catapult_dct2000_close(wtap *wth);
 
 static gboolean catapult_dct2000_dump(wtap_dumper *wdh, const struct wtap_pkthdr *phdr,
@@ -451,7 +451,7 @@ catapult_dct2000_read(wtap *wth, int *err, gchar **err_info,
 static gboolean
 catapult_dct2000_seek_read(wtap *wth, gint64 seek_off,
                            struct wtap_pkthdr *phdr, Buffer *buf,
-                           int len _U_, int *err, gchar **err_info)
+                           int *err, gchar **err_info)
 {
     gint64 offset = 0;
     int length;
diff --git a/wiretap/commview.c b/wiretap/commview.c
index 310131a01a..4283a6f44b 100644
--- a/wiretap/commview.c
+++ b/wiretap/commview.c
@@ -84,8 +84,7 @@ static gboolean commview_read(wtap *wth, int *err, gchar **err_info,
 			      gint64 *data_offset);
 static gboolean commview_seek_read(wtap *wth, gint64 seek_off,
 				   struct wtap_pkthdr *phdr,
-				   Buffer *buf, int length, int *err,
-				   gchar **err_info);
+				   Buffer *buf, int *err, gchar **err_info);
 static gboolean commview_read_header(commview_header_t *cv_hdr, FILE_T fh,
 				     int *err, gchar **err_info);
 static gboolean commview_dump(wtap_dumper *wdh,	const struct wtap_pkthdr *phdr,
@@ -198,7 +197,7 @@ commview_read(wtap *wth, int *err, gchar **err_info, gint64 *data_offset)
 
 static gboolean
 commview_seek_read(wtap *wth, gint64 seek_off, struct wtap_pkthdr *phdr,
-		   Buffer *buf, int length _U_, int *err, gchar **err_info)
+		   Buffer *buf, int *err, gchar **err_info)
 {
 	if(file_seek(wth->random_fh, seek_off, SEEK_SET, err) == -1)
 		return FALSE;
diff --git a/wiretap/cosine.c b/wiretap/cosine.c
index 9a5976a9bc..a13a71e002 100644
--- a/wiretap/cosine.c
+++ b/wiretap/cosine.c
@@ -171,8 +171,7 @@ static gboolean cosine_check_file_type(wtap *wth, int *err, gchar **err_info);
 static gboolean cosine_read(wtap *wth, int *err, gchar **err_info,
 	gint64 *data_offset);
 static gboolean cosine_seek_read(wtap *wth, gint64 seek_off,
-	struct wtap_pkthdr *phdr, Buffer *buf,
-	int len, int *err, gchar **err_info);
+	struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info);
 static int parse_cosine_rec_hdr(struct wtap_pkthdr *phdr, const char *line,
 	int *err, gchar **err_info);
 static gboolean parse_cosine_hex_dump(FILE_T fh, struct wtap_pkthdr *phdr,
@@ -315,7 +314,7 @@ static gboolean cosine_read(wtap *wth, int *err, gchar **err_info,
 /* Used to read packets in random-access fashion */
 static gboolean
 cosine_seek_read(wtap *wth, gint64 seek_off, struct wtap_pkthdr *phdr,
-	Buffer *buf, int len _U_, int *err, gchar **err_info)
+	Buffer *buf, int *err, gchar **err_info)
 {
 	int	pkt_len;
 	char	line[COSINE_LINE_LENGTH];
diff --git a/wiretap/csids.c b/wiretap/csids.c
index ff80ce5e1a..2df917ef9b 100644
--- a/wiretap/csids.c
+++ b/wiretap/csids.c
@@ -49,8 +49,7 @@ typedef struct {
 static gboolean csids_read(wtap *wth, int *err, gchar **err_info,
 	gint64 *data_offset);
 static gboolean csids_seek_read(wtap *wth, gint64 seek_off,
-	struct wtap_pkthdr *phdr, Buffer *buf, int len,
-	int *err, gchar **err_info);
+	struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info);
 static gboolean csids_read_packet(FILE_T fh, csids_t *csids,
 	struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info);
 
@@ -164,7 +163,6 @@ csids_seek_read(wtap *wth,
 		 gint64 seek_off,
 		 struct wtap_pkthdr *phdr,
 		 Buffer *buf,
-		 int len _U_,
 		 int *err,
 		 gchar **err_info)
 {
diff --git a/wiretap/daintree-sna.c b/wiretap/daintree-sna.c
index f35e3cedc9..d2adfd0376 100644
--- a/wiretap/daintree-sna.c
+++ b/wiretap/daintree-sna.c
@@ -83,8 +83,7 @@ static gboolean daintree_sna_read(wtap *wth, int *err, gchar **err_info,
 	gint64 *data_offset);
 
 static gboolean daintree_sna_seek_read(wtap *wth, gint64 seek_off,
-	struct wtap_pkthdr *phdr, Buffer *buf, int len, int *err,
-	gchar **err_info);
+	struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info);
 
 static gboolean daintree_sna_scan_header(struct wtap_pkthdr *phdr,
 	char *readLine, char *readData, int *err, gchar **err_info);
@@ -168,7 +167,7 @@ daintree_sna_read(wtap *wth, int *err, gchar **err_info, gint64 *data_offset)
  * Wireshark opens the capture file for random access when displaying user-selected packets */
 static gboolean
 daintree_sna_seek_read(wtap *wth, gint64 seek_off, struct wtap_pkthdr *phdr,
-	Buffer *buf, int len _U_, int *err, gchar **err_info)
+	Buffer *buf, int *err, gchar **err_info)
 {
 	char readLine[DAINTREE_MAX_LINE_SIZE];
 	char readData[READDATA_BUF_SIZE];
diff --git a/wiretap/dbs-etherwatch.c b/wiretap/dbs-etherwatch.c
index 3aeb1b4122..f346456083 100644
--- a/wiretap/dbs-etherwatch.c
+++ b/wiretap/dbs-etherwatch.c
@@ -89,8 +89,7 @@ static const char dbs_etherwatch_rec_magic[]  =
 static gboolean dbs_etherwatch_read(wtap *wth, int *err, gchar **err_info,
 	gint64 *data_offset);
 static gboolean dbs_etherwatch_seek_read(wtap *wth, gint64 seek_off,
-	struct wtap_pkthdr *phdr, Buffer *buf, int len,
-	int *err, gchar **err_info);
+	struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info);
 static gboolean parse_dbs_etherwatch_packet(struct wtap_pkthdr *phdr, FILE_T fh,
 	Buffer* buf, int *err, gchar **err_info);
 static guint parse_single_hex_dump_line(char* rec, guint8 *buf,
@@ -218,8 +217,7 @@ static gboolean dbs_etherwatch_read(wtap *wth, int *err, gchar **err_info,
 /* Used to read packets in random-access fashion */
 static gboolean
 dbs_etherwatch_seek_read(wtap *wth, gint64 seek_off,
-	struct wtap_pkthdr *phdr, Buffer *buf, int len _U_,
-	int *err, gchar **err_info)
+	struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info)
 {
 	if (file_seek(wth->random_fh, seek_off - 1, SEEK_SET, err) == -1)
 		return FALSE;
diff --git a/wiretap/dct3trace.c b/wiretap/dct3trace.c
index c298dd3f60..b9fb0d531a 100644
--- a/wiretap/dct3trace.c
+++ b/wiretap/dct3trace.c
@@ -78,8 +78,7 @@ static const char dct3trace_magic_end[]  = "</dump>";
 static gboolean dct3trace_read(wtap *wth, int *err, gchar **err_info,
 	gint64 *data_offset);
 static gboolean dct3trace_seek_read(wtap *wth, gint64 seek_off,
-	struct wtap_pkthdr *phdr, Buffer *buf, int len,
-	int *err, gchar **err_info);
+	struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info);
 
 /*
  * Following 3 functions taken from gsmdecode-0.7bis, with permission - http://wiki.thc.org/gsm
@@ -361,8 +360,7 @@ static gboolean dct3trace_read(wtap *wth, int *err, gchar **err_info,
 
 /* Used to read packets in random-access fashion */
 static gboolean dct3trace_seek_read(wtap *wth, gint64 seek_off,
-	struct wtap_pkthdr *phdr, Buffer *buf, int len _U_,
-	int *err, gchar **err_info)
+	struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info)
 {
 	if (file_seek(wth->random_fh, seek_off, SEEK_SET, err) == -1)
 	{
diff --git a/wiretap/erf.c b/wiretap/erf.c
index ee41894641..7eebe0a44a 100644
--- a/wiretap/erf.c
+++ b/wiretap/erf.c
@@ -70,7 +70,7 @@ static gboolean erf_read(wtap *wth, int *err, gchar **err_info,
                          gint64 *data_offset);
 static gboolean erf_seek_read(wtap *wth, gint64 seek_off,
                               struct wtap_pkthdr *phdr, Buffer *buf,
-                              int length, int *err, gchar **err_info);
+                              int *err, gchar **err_info);
 
 static const struct {
   int erf_encap_value;
@@ -309,7 +309,7 @@ static gboolean erf_read(wtap *wth, int *err, gchar **err_info,
 
 static gboolean erf_seek_read(wtap *wth, gint64 seek_off,
                               struct wtap_pkthdr *phdr, Buffer *buf,
-                              int length _U_, int *err, gchar **err_info)
+                              int *err, gchar **err_info)
 {
   erf_header_t erf_header;
   guint32      packet_size;
diff --git a/wiretap/eyesdn.c b/wiretap/eyesdn.c
index 0c520b934d..66897b81df 100644
--- a/wiretap/eyesdn.c
+++ b/wiretap/eyesdn.c
@@ -95,8 +95,7 @@ static const unsigned char eyesdn_hdr_magic[]  =
 static gboolean eyesdn_read(wtap *wth, int *err, gchar **err_info,
 	gint64 *data_offset);
 static gboolean eyesdn_seek_read(wtap *wth, gint64 seek_off,
-	struct wtap_pkthdr *phdr, Buffer *buf, int len,
-	int *err, gchar **err_info);
+	struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info);
 static int read_eyesdn_rec(FILE_T fh, struct wtap_pkthdr *phdr, Buffer* buf,
 	int *err, gchar **err_info);
 
@@ -171,7 +170,7 @@ static gboolean eyesdn_read(wtap *wth, int *err, gchar **err_info,
 /* Used to read packets in random-access fashion */
 static gboolean
 eyesdn_seek_read(wtap *wth, gint64 seek_off, struct wtap_pkthdr *phdr,
-	Buffer *buf, int len _U_, int *err, gchar **err_info)
+	Buffer *buf, int *err, gchar **err_info)
 {
 	if (file_seek(wth->random_fh, seek_off, SEEK_SET, err) == -1)
 		return FALSE;
diff --git a/wiretap/hcidump.c b/wiretap/hcidump.c
index 6530a1207a..055e1179ed 100644
--- a/wiretap/hcidump.c
+++ b/wiretap/hcidump.c
@@ -83,8 +83,7 @@ static gboolean hcidump_read(wtap *wth, int *err, gchar **err_info,
 }
 
 static gboolean hcidump_seek_read(wtap *wth, gint64 seek_off,
-    struct wtap_pkthdr *phdr, Buffer *buf, int length _U_,
-    int *err, gchar **err_info)
+    struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info)
 {
 	if (file_seek(wth->random_fh, seek_off, SEEK_SET, err) == -1)
 		return FALSE;
diff --git a/wiretap/i4btrace.c b/wiretap/i4btrace.c
index d6d1074ffe..9de2a858eb 100644
--- a/wiretap/i4btrace.c
+++ b/wiretap/i4btrace.c
@@ -38,8 +38,7 @@ typedef struct {
 static gboolean i4btrace_read(wtap *wth, int *err, gchar **err_info,
     gint64 *data_offset);
 static gboolean i4btrace_seek_read(wtap *wth, gint64 seek_off,
-    struct wtap_pkthdr *phdr, Buffer *buf, int length,
-    int *err, gchar **err_info);
+    struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info);
 static int i4b_read_rec(wtap *wth, FILE_T fh, struct wtap_pkthdr *phdr,
     Buffer *buf, int *err, gchar **err_info);
 
@@ -124,7 +123,7 @@ static gboolean i4btrace_read(wtap *wth, int *err, gchar **err_info,
 
 static gboolean
 i4btrace_seek_read(wtap *wth, gint64 seek_off, struct wtap_pkthdr *phdr,
-    Buffer *buf, int length _U_, int *err, gchar **err_info)
+    Buffer *buf, int *err, gchar **err_info)
 {
 	if (file_seek(wth->random_fh, seek_off, SEEK_SET, err) == -1)
 		return FALSE;
diff --git a/wiretap/ipfix.c b/wiretap/ipfix.c
index 53ffa032e7..eaf11c930d 100644
--- a/wiretap/ipfix.c
+++ b/wiretap/ipfix.c
@@ -92,8 +92,7 @@ ipfix_read(wtap *wth, int *err, gchar **err_info,
     gint64 *data_offset);
 static gboolean
 ipfix_seek_read(wtap *wth, gint64 seek_off,
-    struct wtap_pkthdr *phdr, Buffer *buf, int length,
-    int *err, gchar **err_info);
+    struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info);
 static void
 ipfix_close(wtap *wth);
 
@@ -302,7 +301,7 @@ ipfix_read(wtap *wth, int *err, gchar **err_info, gint64 *data_offset)
 /* classic wtap: seek to file position and read packet */
 static gboolean
 ipfix_seek_read(wtap *wth, gint64 seek_off, struct wtap_pkthdr *phdr,
-    Buffer *buf, int length _U_, int *err, gchar **err_info)
+    Buffer *buf, int *err, gchar **err_info)
 {
     /* seek to the right file position */
     if (file_seek(wth->random_fh, seek_off, SEEK_SET, err) == -1) {
diff --git a/wiretap/iptrace.c b/wiretap/iptrace.c
index 49c139f8b6..ea1bef4998 100644
--- a/wiretap/iptrace.c
+++ b/wiretap/iptrace.c
@@ -36,14 +36,12 @@
 static gboolean iptrace_read_1_0(wtap *wth, int *err, gchar **err_info,
     gint64 *data_offset);
 static gboolean iptrace_seek_read_1_0(wtap *wth, gint64 seek_off,
-    struct wtap_pkthdr *phdr, Buffer *buf, int packet_size,
-    int *err, gchar **err_info);
+    struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info);
 
 static gboolean iptrace_read_2_0(wtap *wth, int *err, gchar **err_info,
     gint64 *data_offset);
 static gboolean iptrace_seek_read_2_0(wtap *wth, gint64 seek_off,
-    struct wtap_pkthdr *phdr, Buffer *buf, int packet_size,
-    int *err, gchar **err_info);
+    struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info);
 
 static int iptrace_read_rec_header(FILE_T fh, guint8 *header, int header_len,
     int *err, gchar **err_info);
@@ -247,8 +245,7 @@ static gboolean iptrace_read_1_0(wtap *wth, int *err, gchar **err_info,
 }
 
 static gboolean iptrace_seek_read_1_0(wtap *wth, gint64 seek_off,
-    struct wtap_pkthdr *phdr, Buffer *buf, int packet_size _U_,
-    int *err, gchar **err_info)
+    struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info)
 {
 	if (file_seek(wth->random_fh, seek_off, SEEK_SET, err) == -1)
 		return FALSE;
@@ -443,8 +440,7 @@ static gboolean iptrace_read_2_0(wtap *wth, int *err, gchar **err_info,
 }
 
 static gboolean iptrace_seek_read_2_0(wtap *wth, gint64 seek_off,
-    struct wtap_pkthdr *phdr, Buffer *buf, int packet_size _U_,
-    int *err, gchar **err_info)
+    struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info)
 {
 	if (file_seek(wth->random_fh, seek_off, SEEK_SET, err) == -1)
 		return FALSE;
diff --git a/wiretap/iseries.c b/wiretap/iseries.c
index 2a7686467f..561c9830cf 100644
--- a/wiretap/iseries.c
+++ b/wiretap/iseries.c
@@ -185,8 +185,7 @@ static gboolean iseries_read (wtap * wth, int *err, gchar ** err_info,
                               gint64 *data_offset);
 static gboolean iseries_seek_read (wtap * wth, gint64 seek_off,
                                    struct wtap_pkthdr *phdr,
-                                   Buffer * buf, int len, int *err,
-                                   gchar ** err_info);
+                                   Buffer * buf, int *err, gchar ** err_info);
 static gboolean iseries_check_file_type (wtap * wth, int *err, gchar **err_info,
                                          int format);
 static gint64 iseries_seek_next_packet (wtap * wth, int *err, gchar **err_info);
@@ -462,7 +461,7 @@ iseries_seek_next_packet (wtap * wth, int *err, gchar **err_info)
  */
 static gboolean
 iseries_seek_read (wtap * wth, gint64 seek_off, struct wtap_pkthdr *phdr,
-                   Buffer * buf, int len _U_, int *err, gchar ** err_info)
+                   Buffer * buf, int *err, gchar ** err_info)
 {
 
   /* seek to packet location */
diff --git a/wiretap/k12.c b/wiretap/k12.c
index cb9e22e5cb..10687f8412 100644
--- a/wiretap/k12.c
+++ b/wiretap/k12.c
@@ -687,7 +687,7 @@ static gboolean k12_read(wtap *wth, int *err, gchar **err_info, gint64 *data_off
 }
 
 
-static gboolean k12_seek_read(wtap *wth, gint64 seek_off, struct wtap_pkthdr *phdr, Buffer *buf, int length _U_, int *err, gchar **err_info) {
+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;
     gint len;
diff --git a/wiretap/k12text.l b/wiretap/k12text.l
index 077d5c6246..ebec0ac7b9 100644
--- a/wiretap/k12text.l
+++ b/wiretap/k12text.l
@@ -291,7 +291,7 @@ k12text_read(wtap *wth, int *err, char ** err_info, gint64 *data_offset)
 }
 
 static gboolean
-k12text_seek_read(wtap *wth, gint64 seek_off, struct wtap_pkthdr *phdr, Buffer *buf, int length _U_, int *err, char **err_info)
+k12text_seek_read(wtap *wth, gint64 seek_off, struct wtap_pkthdr *phdr, Buffer *buf, int *err, char **err_info)
 {
 	if ( file_seek(wth->random_fh, seek_off, SEEK_SET, err) == -1) {
 		return FALSE;
diff --git a/wiretap/lanalyzer.c b/wiretap/lanalyzer.c
index 0ff70265ef..97f9764411 100644
--- a/wiretap/lanalyzer.c
+++ b/wiretap/lanalyzer.c
@@ -275,8 +275,7 @@ typedef struct {
 static gboolean lanalyzer_read(wtap *wth, int *err, gchar **err_info,
     gint64 *data_offset);
 static gboolean lanalyzer_seek_read(wtap *wth, gint64 seek_off,
-    struct wtap_pkthdr *phdr, Buffer *buf, int length,
-    int *err, gchar **err_info);
+    struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info);
 static gboolean lanalyzer_dump_close(wtap_dumper *wdh, int *err);
 
 int lanalyzer_open(wtap *wth, int *err, gchar **err_info)
@@ -574,8 +573,7 @@ static gboolean lanalyzer_read(wtap *wth, int *err, gchar **err_info,
 }
 
 static gboolean lanalyzer_seek_read(wtap *wth, gint64 seek_off,
-    struct wtap_pkthdr *phdr, Buffer *buf, int length _U_, int *err,
-    gchar **err_info)
+    struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info)
 {
 	if (file_seek(wth->random_fh, seek_off, SEEK_SET, err) == -1)
 		return FALSE;
diff --git a/wiretap/libpcap.c b/wiretap/libpcap.c
index dd246cd65f..8de8724236 100644
--- a/wiretap/libpcap.c
+++ b/wiretap/libpcap.c
@@ -68,8 +68,7 @@ static libpcap_try_t libpcap_try(wtap *wth, int *err);
 static gboolean libpcap_read(wtap *wth, int *err, gchar **err_info,
     gint64 *data_offset);
 static gboolean libpcap_seek_read(wtap *wth, gint64 seek_off,
-    struct wtap_pkthdr *phdr, Buffer *buf, int length,
-    int *err, gchar **err_info);
+    struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info);
 static int libpcap_read_header(wtap *wth, FILE_T fh, int *err, gchar **err_info,
     struct pcaprec_ss990915_hdr *hdr);
 static void adjust_header(wtap *wth, struct pcaprec_hdr *hdr);
@@ -604,7 +603,7 @@ static gboolean libpcap_read(wtap *wth, int *err, gchar **err_info,
 
 static gboolean
 libpcap_seek_read(wtap *wth, gint64 seek_off, struct wtap_pkthdr *phdr,
-    Buffer *buf, int length _U_, int *err, gchar **err_info)
+    Buffer *buf, int *err, gchar **err_info)
 {
 	if (file_seek(wth->random_fh, seek_off, SEEK_SET, err) == -1)
 		return FALSE;
diff --git a/wiretap/mime_file.c b/wiretap/mime_file.c
index 1925d174df..d1e25083f1 100644
--- a/wiretap/mime_file.c
+++ b/wiretap/mime_file.c
@@ -148,7 +148,7 @@ mime_read(wtap *wth, int *err, gchar **err_info, gint64 *data_offset)
 }
 
 static gboolean
-mime_seek_read(wtap *wth, gint64 seek_off, struct wtap_pkthdr *phdr, Buffer *buf, int length _U_, int *err, gchar **err_info)
+mime_seek_read(wtap *wth, gint64 seek_off, struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info)
 {
 	/* there is only one packet */
 	if (seek_off > 0) {
diff --git a/wiretap/mp2t.c b/wiretap/mp2t.c
index 2df745b9e1..a7102c0ea2 100644
--- a/wiretap/mp2t.c
+++ b/wiretap/mp2t.c
@@ -130,7 +130,7 @@ mp2t_read(wtap *wth, int *err, gchar **err_info, gint64 *data_offset)
 
 static gboolean
 mp2t_seek_read(wtap *wth, gint64 seek_off, struct wtap_pkthdr *phdr,
-        Buffer *buf, int length _U_, int *err, gchar **err_info)
+        Buffer *buf, int *err, gchar **err_info)
 {
     mp2t_filetype_t *mp2t;
 
diff --git a/wiretap/mpeg.c b/wiretap/mpeg.c
index 62d929af83..dcccd6ade1 100644
--- a/wiretap/mpeg.c
+++ b/wiretap/mpeg.c
@@ -233,7 +233,7 @@ mpeg_read(wtap *wth, int *err, gchar **err_info, gint64 *data_offset)
 
 static gboolean
 mpeg_seek_read(wtap *wth, gint64 seek_off,
-		struct wtap_pkthdr *phdr, Buffer *buf, int length _U_,
+		struct wtap_pkthdr *phdr, Buffer *buf,
 		int *err, gchar **err_info)
 {
 	if (file_seek(wth->random_fh, seek_off, SEEK_SET, err) == -1)
diff --git a/wiretap/netmon.c b/wiretap/netmon.c
index bf5eec3cee..ad1aacb8f6 100644
--- a/wiretap/netmon.c
+++ b/wiretap/netmon.c
@@ -180,8 +180,7 @@ static const int netmon_encap[] = {
 static gboolean netmon_read(wtap *wth, int *err, gchar **err_info,
     gint64 *data_offset);
 static gboolean netmon_seek_read(wtap *wth, gint64 seek_off,
-    struct wtap_pkthdr *phdr, Buffer *buf, int length,
-    int *err, gchar **err_info);
+    struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info);
 static gboolean netmon_read_atm_pseudoheader(FILE_T fh,
     union wtap_pseudo_header *pseudo_header, int *err, gchar **err_info);
 static int netmon_read_rec_trailer(FILE_T fh, int trlr_size, int *err,
@@ -748,8 +747,7 @@ again:
 
 static gboolean
 netmon_seek_read(wtap *wth, gint64 seek_off,
-    struct wtap_pkthdr *phdr, Buffer *buf, int length _U_,
-    int *err, gchar **err_info)
+    struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info)
 {
 	netmon_t *netmon = (netmon_t *)wth->priv;
 
diff --git a/wiretap/netscaler.c b/wiretap/netscaler.c
index b1cc5d1263..477a871e58 100644
--- a/wiretap/netscaler.c
+++ b/wiretap/netscaler.c
@@ -577,11 +577,11 @@ static gboolean nstrace_read_v20(wtap *wth, int *err, gchar **err_info,
                                  gint64 *data_offset);
 static gboolean nstrace_seek_read_v10(wtap *wth, gint64 seek_off,
                                       struct wtap_pkthdr *phdr,
-                                      Buffer *buf, int length,
+                                      Buffer *buf,
                                       int *err, gchar **err_info);
 static gboolean nstrace_seek_read_v20(wtap *wth, gint64 seek_off,
                                       struct wtap_pkthdr *phdr,
-                                      Buffer *buf, int length,
+                                      Buffer *buf,
                                       int *err, gchar **err_info);
 static void nstrace_close(wtap *wth);
 
@@ -1142,8 +1142,7 @@ static gboolean nstrace_read_v20(wtap *wth, int *err, gchar **err_info, gint64 *
 #undef PACKET_DESCRIBE
 
 static gboolean nstrace_seek_read_v10(wtap *wth, gint64 seek_off,
-    struct wtap_pkthdr *phdr, Buffer *buf, int length _U_,
-    int *err, gchar **err_info)
+    struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info)
 {
     nspr_hd_v10_t hdr;
     int bytes_read;
@@ -1234,8 +1233,7 @@ static gboolean nstrace_seek_read_v10(wtap *wth, gint64 seek_off,
     }while(0)
 
 static gboolean nstrace_seek_read_v20(wtap *wth, gint64 seek_off,
-    struct wtap_pkthdr *phdr, Buffer *buf, int length _U_,
-    int *err, gchar **err_info)
+    struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info)
 {
     nspr_hd_v20_t hdr;
     int bytes_read;
diff --git a/wiretap/netscreen.c b/wiretap/netscreen.c
index 80ef74cc19..8b911b446c 100644
--- a/wiretap/netscreen.c
+++ b/wiretap/netscreen.c
@@ -73,7 +73,7 @@ static gboolean netscreen_read(wtap *wth, int *err, gchar **err_info,
 	gint64 *data_offset);
 static gboolean netscreen_seek_read(wtap *wth, gint64 seek_off,
 	struct wtap_pkthdr *phdr, Buffer *buf,
-	int len, int *err, gchar **err_info);
+	int *err, gchar **err_info);
 static int parse_netscreen_rec_hdr(struct wtap_pkthdr *phdr, const char *line,
 	char *cap_int, gboolean *cap_dir, char *cap_dst,
 	int *err, gchar **err_info);
@@ -241,7 +241,7 @@ static gboolean netscreen_read(wtap *wth, int *err, gchar **err_info,
 /* Used to read packets in random-access fashion */
 static gboolean
 netscreen_seek_read(wtap *wth, gint64 seek_off,
-	struct wtap_pkthdr *phdr, Buffer *buf, int len _U_,
+	struct wtap_pkthdr *phdr, Buffer *buf,
 	int *err, gchar **err_info)
 {
 	int		pkt_len;
diff --git a/wiretap/nettl.c b/wiretap/nettl.c
index ee193592d9..e869fb711f 100644
--- a/wiretap/nettl.c
+++ b/wiretap/nettl.c
@@ -181,7 +181,7 @@ static gboolean nettl_read(wtap *wth, int *err, gchar **err_info,
 		gint64 *data_offset);
 static gboolean nettl_seek_read(wtap *wth, gint64 seek_off,
 		struct wtap_pkthdr *phdr, Buffer *buf,
-		int length, int *err, gchar **err_info);
+		int *err, gchar **err_info);
 static gboolean nettl_read_rec(wtap *wth, FILE_T fh, struct wtap_pkthdr *phdr,
 		Buffer *buf, int *err, gchar **err_info);
 static gboolean nettl_dump(wtap_dumper *wdh, const struct wtap_pkthdr *phdr,
@@ -320,7 +320,7 @@ static gboolean nettl_read(wtap *wth, int *err, gchar **err_info,
 
 static gboolean
 nettl_seek_read(wtap *wth, gint64 seek_off, struct wtap_pkthdr *phdr,
-		Buffer *buf, int length _U_, int *err, gchar **err_info)
+		Buffer *buf, int *err, gchar **err_info)
 {
     if (file_seek(wth->random_fh, seek_off, SEEK_SET, err) == -1)
 	return FALSE;
diff --git a/wiretap/network_instruments.c b/wiretap/network_instruments.c
index 6b7fc7ff78..2e9f340288 100644
--- a/wiretap/network_instruments.c
+++ b/wiretap/network_instruments.c
@@ -101,8 +101,7 @@ static void init_gmt_to_localtime_offset(void)
 static gboolean observer_read(wtap *wth, int *err, gchar **err_info,
     gint64 *data_offset);
 static gboolean observer_seek_read(wtap *wth, gint64 seek_off,
-    struct wtap_pkthdr *phdr, Buffer *buf, int length,
-    int *err, gchar **err_info);
+    struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info);
 static int read_packet_header(FILE_T fh, union wtap_pseudo_header *pseudo_header,
     packet_entry_header *packet_header, int *err, gchar **err_info);
 static gboolean process_packet_header(wtap *wth,
@@ -312,8 +311,7 @@ static gboolean observer_read(wtap *wth, int *err, gchar **err_info,
 
 /* Reads a packet at an offset. */
 static gboolean observer_seek_read(wtap *wth, gint64 seek_off,
-    struct wtap_pkthdr *phdr, Buffer *buf, int length _U_,
-    int *err, gchar **err_info)
+    struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info)
 {
     union wtap_pseudo_header *pseudo_header = &phdr->pseudo_header;
     packet_entry_header packet_header;
diff --git a/wiretap/netxray.c b/wiretap/netxray.c
index 1aaaf8879c..189c70a04c 100644
--- a/wiretap/netxray.c
+++ b/wiretap/netxray.c
@@ -407,8 +407,7 @@ typedef struct {
 static gboolean netxray_read(wtap *wth, int *err, gchar **err_info,
     gint64 *data_offset);
 static gboolean netxray_seek_read(wtap *wth, gint64 seek_off,
-    struct wtap_pkthdr *phdr, Buffer *buf, int length,
-    int *err, gchar **err_info);
+    struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info);
 static int netxray_process_rec_header(wtap *wth, FILE_T fh,
     struct wtap_pkthdr *phdr, int *err, gchar **err_info);
 static void netxray_guess_atm_type(wtap *wth, struct wtap_pkthdr *phdr,
@@ -1089,7 +1088,7 @@ reread:
 
 static gboolean
 netxray_seek_read(wtap *wth, gint64 seek_off,
-		  struct wtap_pkthdr *phdr, Buffer *buf, int length _U_,
+		  struct wtap_pkthdr *phdr, Buffer *buf,
 		  int *err, gchar **err_info)
 {
 	if (file_seek(wth->random_fh, seek_off, SEEK_SET, err) == -1)
diff --git a/wiretap/ngsniffer.c b/wiretap/ngsniffer.c
index 64ba7e3232..0e33072ca7 100644
--- a/wiretap/ngsniffer.c
+++ b/wiretap/ngsniffer.c
@@ -514,8 +514,7 @@ static int process_rec_header2_v145(wtap *wth, unsigned char *buffer,
 static gboolean ngsniffer_read(wtap *wth, int *err, gchar **err_info,
     gint64 *data_offset);
 static gboolean ngsniffer_seek_read(wtap *wth, gint64 seek_off,
-    struct wtap_pkthdr *phdr, Buffer *buf, int packet_size,
-    int *err, gchar **err_info);
+    struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info);
 static int ngsniffer_process_record(wtap *wth, gboolean is_random,
     guint *padding, struct wtap_pkthdr *phdr, Buffer *buf, int *err,
     gchar **err_info);
@@ -1126,8 +1125,7 @@ ngsniffer_read(wtap *wth, int *err, gchar **err_info, gint64 *data_offset)
 
 static gboolean
 ngsniffer_seek_read(wtap *wth, gint64 seek_off,
-    struct wtap_pkthdr *phdr, Buffer *buf, int packet_size _U_,
-    int *err, gchar **err_info)
+    struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info)
 {
 	int	ret;
 
diff --git a/wiretap/packetlogger.c b/wiretap/packetlogger.c
index e905f8bed0..f3709b6917 100644
--- a/wiretap/packetlogger.c
+++ b/wiretap/packetlogger.c
@@ -50,8 +50,7 @@ static gboolean packetlogger_read(wtap *wth, int *err, gchar **err_info,
 				  gint64 *data_offset);
 static gboolean packetlogger_seek_read(wtap *wth, gint64 seek_off,
 				       struct wtap_pkthdr *phdr,
-				       Buffer *buf, int length, int *err,
-				       gchar **err_info);
+				       Buffer *buf, int *err, gchar **err_info);
 static gboolean packetlogger_read_header(packetlogger_header_t *pl_hdr,
 					 FILE_T fh, int *err, gchar **err_info);
 static gboolean packetlogger_read_packet(FILE_T fh, struct wtap_pkthdr *phdr,
@@ -107,7 +106,7 @@ packetlogger_read(wtap *wth, int *err, gchar **err_info, gint64 *data_offset)
 
 static gboolean
 packetlogger_seek_read(wtap *wth, gint64 seek_off, struct wtap_pkthdr *phdr,
-		       Buffer *buf, int length _U_, int *err, gchar **err_info)
+		       Buffer *buf, int *err, gchar **err_info)
 {
 	if(file_seek(wth->random_fh, seek_off, SEEK_SET, err) == -1)
 		return FALSE;
diff --git a/wiretap/pcapng.c b/wiretap/pcapng.c
index 0824114559..86be49d20d 100644
--- a/wiretap/pcapng.c
+++ b/wiretap/pcapng.c
@@ -62,8 +62,7 @@ pcapng_read(wtap *wth, int *err, gchar **err_info,
     gint64 *data_offset);
 static gboolean
 pcapng_seek_read(wtap *wth, gint64 seek_off,
-    struct wtap_pkthdr *phdr, Buffer *buf, int length,
-    int *err, gchar **err_info);
+    struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info);
 static void
 pcapng_close(wtap *wth);
 
@@ -2388,7 +2387,7 @@ got_packet:
 /* classic wtap: seek to file position and read packet */
 static gboolean
 pcapng_seek_read(wtap *wth, gint64 seek_off,
-    struct wtap_pkthdr *phdr, Buffer *buf, int length _U_,
+    struct wtap_pkthdr *phdr, Buffer *buf,
     int *err, gchar **err_info)
 {
         pcapng_t *pcapng = (pcapng_t *)wth->priv;
diff --git a/wiretap/peekclassic.c b/wiretap/peekclassic.c
index 6873953ec4..5bed0bee6c 100644
--- a/wiretap/peekclassic.c
+++ b/wiretap/peekclassic.c
@@ -143,15 +143,13 @@ typedef struct {
 static gboolean peekclassic_read_v7(wtap *wth, int *err, gchar **err_info,
     gint64 *data_offset);
 static gboolean peekclassic_seek_read_v7(wtap *wth, gint64 seek_off,
-    struct wtap_pkthdr *phdr, Buffer *buf, int length,
-    int *err, gchar **err_info);
+    struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info);
 static int peekclassic_read_packet_v7(wtap *wth, FILE_T fh,
     struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info);
 static gboolean peekclassic_read_v56(wtap *wth, int *err, gchar **err_info,
     gint64 *data_offset);
 static gboolean peekclassic_seek_read_v56(wtap *wth, gint64 seek_off,
-    struct wtap_pkthdr *phdr, Buffer *buf, int length,
-    int *err, gchar **err_info);
+    struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info);
 static gboolean peekclassic_read_packet_v56(wtap *wth, FILE_T fh,
     struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info);
 
@@ -392,8 +390,7 @@ static gboolean peekclassic_read_v7(wtap *wth, int *err, gchar **err_info,
 }
 
 static gboolean peekclassic_seek_read_v7(wtap *wth, gint64 seek_off,
-    struct wtap_pkthdr *phdr, Buffer *buf, int length _U_,
-    int *err, gchar **err_info)
+    struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info)
 {
 	if (file_seek(wth->random_fh, seek_off, SEEK_SET, err) == -1)
 		return FALSE;
@@ -516,8 +513,7 @@ static gboolean peekclassic_read_v56(wtap *wth, int *err, gchar **err_info,
 }
 
 static gboolean peekclassic_seek_read_v56(wtap *wth, gint64 seek_off,
-    struct wtap_pkthdr *phdr, Buffer *buf, int length _U_,
-    int *err, gchar **err_info)
+    struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info)
 {
 	if (file_seek(wth->random_fh, seek_off, SEEK_SET, err) == -1)
 		return FALSE;
diff --git a/wiretap/peektagged.c b/wiretap/peektagged.c
index bceb21bb9c..972c9a78d7 100644
--- a/wiretap/peektagged.c
+++ b/wiretap/peektagged.c
@@ -128,8 +128,7 @@ typedef struct {
 static gboolean peektagged_read(wtap *wth, int *err, gchar **err_info,
     gint64 *data_offset);
 static gboolean peektagged_seek_read(wtap *wth, gint64 seek_off,
-    struct wtap_pkthdr *phdr, Buffer *buf, int length,
-    int *err, gchar **err_info);
+    struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info);
 
 static int wtap_file_read_pattern (wtap *wth, const char *pattern, int *err,
 				gchar **err_info)
@@ -660,8 +659,7 @@ static gboolean peektagged_read(wtap *wth, int *err, gchar **err_info,
 
 static gboolean
 peektagged_seek_read(wtap *wth, gint64 seek_off,
-    struct wtap_pkthdr *phdr, Buffer *buf, int length _U_,
-    int *err, gchar **err_info)
+    struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info)
 {
     if (file_seek(wth->random_fh, seek_off, SEEK_SET, err) == -1)
 	return FALSE;
diff --git a/wiretap/pppdump.c b/wiretap/pppdump.c
index b3738757f1..c873fa2ea9 100644
--- a/wiretap/pppdump.c
+++ b/wiretap/pppdump.c
@@ -100,8 +100,7 @@ typedef enum {
 static gboolean pppdump_read(wtap *wth, int *err, gchar **err_info,
 	gint64 *data_offset);
 static gboolean pppdump_seek_read(wtap *wth, gint64 seek_off,
-	struct wtap_pkthdr *phdr, Buffer *buf, int len,
-	int *err, gchar **err_info);
+	struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info);
 
 /*
  * Information saved about a packet, during the initial sequential pass
@@ -723,7 +722,6 @@ pppdump_seek_read(wtap *wth,
 		 gint64 seek_off,
 		 struct wtap_pkthdr *phdr,
 		 Buffer *buf,
-		 int len _U_,
 		 int *err,
 		 gchar **err_info)
 {
diff --git a/wiretap/radcom.c b/wiretap/radcom.c
index d462bbd992..40af08306a 100644
--- a/wiretap/radcom.c
+++ b/wiretap/radcom.c
@@ -89,8 +89,7 @@ struct radcomrec_hdr {
 static gboolean radcom_read(wtap *wth, int *err, gchar **err_info,
 	gint64 *data_offset);
 static gboolean radcom_seek_read(wtap *wth, gint64 seek_off,
-	struct wtap_pkthdr *phdr, Buffer *buf, int length,
-	int *err, gchar **err_info);
+	struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info);
 static gboolean radcom_read_rec(wtap *wth, FILE_T fh, struct wtap_pkthdr *phdr,
 	Buffer *buf, int *err, gchar **err_info);
 static gboolean radcom_read_rec_data(FILE_T fh, guint8 *pd, int length,
@@ -290,7 +289,7 @@ static gboolean radcom_read(wtap *wth, int *err, gchar **err_info,
 
 static gboolean
 radcom_seek_read(wtap *wth, gint64 seek_off,
-		 struct wtap_pkthdr *phdr, Buffer *buf, int length _U_,
+		 struct wtap_pkthdr *phdr, Buffer *buf,
 		 int *err, gchar **err_info)
 {
 	if (file_seek(wth->random_fh, seek_off, SEEK_SET, err) == -1)
diff --git a/wiretap/snoop.c b/wiretap/snoop.c
index 558690b9f1..fb9253706b 100644
--- a/wiretap/snoop.c
+++ b/wiretap/snoop.c
@@ -89,8 +89,7 @@ struct shomiti_trailer {
 static gboolean snoop_read(wtap *wth, int *err, gchar **err_info,
     gint64 *data_offset);
 static gboolean snoop_seek_read(wtap *wth, gint64 seek_off,
-    struct wtap_pkthdr *phdr, Buffer *buf, int length,
-    int *err, gchar **err_info);
+    struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info);
 static int snoop_read_packet(wtap *wth, FILE_T fh, struct wtap_pkthdr *phdr,
     Buffer *buf, int *err, gchar **err_info);
 static gboolean snoop_read_atm_pseudoheader(FILE_T fh,
@@ -495,8 +494,7 @@ static gboolean snoop_read(wtap *wth, int *err, gchar **err_info,
 
 static gboolean
 snoop_seek_read(wtap *wth, gint64 seek_off,
-    struct wtap_pkthdr *phdr, Buffer *buf, int length _U_,
-    int *err, gchar **err_info)
+    struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info)
 {
 	if (file_seek(wth->random_fh, seek_off, SEEK_SET, err) == -1)
 		return FALSE;
diff --git a/wiretap/stanag4607.c b/wiretap/stanag4607.c
index ed02bd5bea..ae3a5c25d1 100644
--- a/wiretap/stanag4607.c
+++ b/wiretap/stanag4607.c
@@ -159,7 +159,7 @@ static gboolean stanag4607_read(wtap *wth, int *err, gchar **err_info, gint64 *d
 
 static gboolean stanag4607_seek_read(wtap *wth, gint64 seek_off,
                                struct wtap_pkthdr *phdr,
-                               Buffer *buf, int length _U_, int *err, gchar **err_info)
+                               Buffer *buf, int *err, gchar **err_info)
 {
   if (file_seek(wth->random_fh, seek_off, SEEK_SET, err) == -1)
     return FALSE;
diff --git a/wiretap/tnef.c b/wiretap/tnef.c
index 22cced79a8..8aeafaec51 100644
--- a/wiretap/tnef.c
+++ b/wiretap/tnef.c
@@ -83,7 +83,7 @@ static gboolean tnef_read(wtap *wth, int *err, gchar **err_info, gint64 *data_of
 
 static gboolean tnef_seek_read(wtap *wth, gint64 seek_off,
                                struct wtap_pkthdr *phdr,
-                               Buffer *buf, int length _U_, int *err, gchar **err_info)
+                               Buffer *buf, int *err, gchar **err_info)
 {
   /* there is only one packet */
   if(seek_off > 0) {
diff --git a/wiretap/toshiba.c b/wiretap/toshiba.c
index d35b2c8023..4d537833b8 100644
--- a/wiretap/toshiba.c
+++ b/wiretap/toshiba.c
@@ -110,8 +110,7 @@ static const char toshiba_rec_magic[]  = { '[', 'N', 'o', '.' };
 static gboolean toshiba_read(wtap *wth, int *err, gchar **err_info,
 	gint64 *data_offset);
 static gboolean toshiba_seek_read(wtap *wth, gint64 seek_off,
-	struct wtap_pkthdr *phdr, Buffer *buf, int len,
-	int *err, gchar **err_info);
+	struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info);
 static gboolean parse_single_hex_dump_line(char* rec, guint8 *buf,
 	guint byte_offset);
 static gboolean parse_toshiba_packet(FILE_T fh, struct wtap_pkthdr *phdr,
@@ -236,7 +235,7 @@ static gboolean toshiba_read(wtap *wth, int *err, gchar **err_info,
 /* Used to read packets in random-access fashion */
 static gboolean
 toshiba_seek_read(wtap *wth, gint64 seek_off,
-	struct wtap_pkthdr *phdr, Buffer *buf, int len _U_,
+	struct wtap_pkthdr *phdr, Buffer *buf,
 	int *err, gchar **err_info)
 {
 	if (file_seek(wth->random_fh, seek_off - 1, SEEK_SET, err) == -1)
diff --git a/wiretap/visual.c b/wiretap/visual.c
index 8c70495f9c..d73fa2515a 100644
--- a/wiretap/visual.c
+++ b/wiretap/visual.c
@@ -163,8 +163,7 @@ struct visual_write_info
 static gboolean visual_read(wtap *wth, int *err, gchar **err_info,
     gint64 *data_offset);
 static gboolean visual_seek_read(wtap *wth, gint64 seek_off,
-    struct wtap_pkthdr *phdr, Buffer *buf, int packet_size,
-    int *err, gchar **err_info);
+    struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info);
 static gboolean visual_read_packet(wtap *wth, FILE_T fh,
     struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info);
 static gboolean visual_dump(wtap_dumper *wdh, const struct wtap_pkthdr *phdr,
@@ -307,8 +306,7 @@ static gboolean visual_read(wtap *wth, int *err, gchar **err_info,
 
 /* Read packet header and data for random access. */
 static gboolean visual_seek_read(wtap *wth, gint64 seek_off,
-    struct wtap_pkthdr *phdr, Buffer *buf, int len _U_,
-    int *err, gchar **err_info)
+    struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info)
 {
     /* Seek to the packet header */
     if (file_seek(wth->random_fh, seek_off, SEEK_SET, err) == -1)
diff --git a/wiretap/vms.c b/wiretap/vms.c
index 50582940be..b8c4f703bc 100644
--- a/wiretap/vms.c
+++ b/wiretap/vms.c
@@ -144,8 +144,7 @@ to handle them.
 static gboolean vms_read(wtap *wth, int *err, gchar **err_info,
     gint64 *data_offset);
 static gboolean vms_seek_read(wtap *wth, gint64 seek_off,
-    struct wtap_pkthdr *phdr, Buffer *buf, int len,
-    int *err, gchar **err_info);
+    struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info);
 static gboolean parse_single_hex_dump_line(char* rec, guint8 *buf,
     long byte_offset, int in_off, int remaining_bytes);
 static gboolean parse_vms_packet(FILE_T fh, struct wtap_pkthdr *phdr,
@@ -282,7 +281,7 @@ static gboolean vms_read(wtap *wth, int *err, gchar **err_info,
 /* Used to read packets in random-access fashion */
 static gboolean
 vms_seek_read(wtap *wth, gint64 seek_off, struct wtap_pkthdr *phdr,
-    Buffer *buf, int len _U_, int *err, gchar **err_info)
+    Buffer *buf, int *err, gchar **err_info)
 {
     if (file_seek(wth->random_fh, seek_off - 1, SEEK_SET, err) == -1)
         return FALSE;
diff --git a/wiretap/vwr.c b/wiretap/vwr.c
index 11a3d51e0d..fde668f997 100644
--- a/wiretap/vwr.c
+++ b/wiretap/vwr.c
@@ -624,7 +624,7 @@ static void         setup_defaults(vwr_t *, guint16);
 
 static gboolean     vwr_read(wtap *, int *, gchar **, gint64 *);
 static gboolean     vwr_seek_read(wtap *, gint64, struct wtap_pkthdr *phdr,
-                                  Buffer *, int, int *, gchar **);
+                                  Buffer *, int *, gchar **);
 
 static gboolean     vwr_read_rec_header(vwr_t *, FILE_T, int *, int *, int *, gchar **);
 static gboolean     vwr_process_rec_data(FILE_T fh, int rec_size,
@@ -732,8 +732,7 @@ static gboolean vwr_read(wtap *wth, int *err, gchar **err_info, gint64 *data_off
 /* read a random frame in the middle of a file; the start of the PLCP frame is @ seek_off */
 
 static gboolean vwr_seek_read(wtap *wth, gint64 seek_off,
-    struct wtap_pkthdr *phdr, Buffer *buf, int pkt_size _U_,
-    int *err, gchar **err_info)
+    struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info)
 {
     vwr_t *vwr = (vwr_t *)wth->priv;
     int    rec_size, IS_TX;
diff --git a/wiretap/wtap-int.h b/wiretap/wtap-int.h
index 5804e3c90e..fe1ca9d8aa 100644
--- a/wiretap/wtap-int.h
+++ b/wiretap/wtap-int.h
@@ -45,7 +45,7 @@ int wtap_fstat(wtap *wth, ws_statb64 *statb, int *err);
 typedef gboolean (*subtype_read_func)(struct wtap*, int*, char**, gint64*);
 typedef gboolean (*subtype_seek_read_func)(struct wtap*, gint64,
                                            struct wtap_pkthdr *, Buffer *buf,
-                                           int, int *, char **);
+                                           int *, char **);
 /**
  * Struct holding data of the currently read file.
  */
diff --git a/wiretap/wtap.c b/wiretap/wtap.c
index 2d515721a1..64fbcf8d69 100644
--- a/wiretap/wtap.c
+++ b/wiretap/wtap.c
@@ -1035,9 +1035,7 @@ wtap_buf_ptr(wtap *wth)
 
 gboolean
 wtap_seek_read(wtap *wth, gint64 seek_off,
-	struct wtap_pkthdr *phdr, Buffer *buf, int len,
-	int *err, gchar **err_info)
+	struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info)
 {
-	return wth->subtype_seek_read(wth, seek_off, phdr, buf, len,
-		err, err_info);
+	return wth->subtype_seek_read(wth, seek_off, phdr, buf, err, err_info);
 }
diff --git a/wiretap/wtap.h b/wiretap/wtap.h
index 6027559737..d9dbae6e03 100644
--- a/wiretap/wtap.h
+++ b/wiretap/wtap.h
@@ -1279,8 +1279,7 @@ gboolean wtap_read(wtap *wth, int *err, gchar **err_info,
 
 WS_DLL_PUBLIC
 gboolean wtap_seek_read (wtap *wth, gint64 seek_off,
-	struct wtap_pkthdr *phdr, Buffer *buf, int len,
-	int *err, gchar **err_info);
+	struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info);
 
 /*** get various information snippets about the current packet ***/
 WS_DLL_PUBLIC