TVB API deprecations and cleanup

- rename tvb_length and similar to tvb_captured_length and similar; leave
  #defines in place for backwards-compat, but mark them clearly as deprecated in
  code comments and in checkAPI
- remove tvb_get_string as C code and just leave a #define in place for
  backwards-compat; mark it clearly as deprecated in code comment and checkAPI
- update READMEs and sample dissector for all of the above
- while in the neighbourhood, make checkAPI skip (and warn) for missing files
  instead of bailing on the whole check, so subsequent files still get checked

Change-Id: I32fc437896ca86ca73e9b49d5f50400adf8ec5ad
Reviewed-on: https://code.wireshark.org/review/311
Reviewed-by: Evan Huus <eapache@gmail.com>

2 files changed, 35 insertions, 37 deletions

diff --git a/epan/tvbuff.c b/epan/tvbuff.c
index a0371a7423..123e7ec473 100644
--- a/epan/tvbuff.c
+++ b/epan/tvbuff.c
@@ -304,7 +304,7 @@ tvb_new_octet_aligned(tvbuff_t *tvb, guint32 bit_offset, gint32 no_of_bits)
 	right = 8 - left; /* for right-shifting */
 
 	if (no_of_bits == -1) {
-		datalen = tvb_length_remaining(tvb, byte_offset);
+		datalen = tvb_captured_length_remaining(tvb, byte_offset);
 		remaining_bits = 0;
 	} else {
 		datalen = no_of_bits >> 3;
@@ -326,7 +326,7 @@ tvb_new_octet_aligned(tvbuff_t *tvb, guint32 bit_offset, gint32 no_of_bits)
  	* if non extra byte is available, the last shifted byte requires
  	* special treatment
  	*/
-	if (tvb_length_remaining(tvb, byte_offset) > datalen) {
+	if (tvb_captured_length_remaining(tvb, byte_offset) > datalen) {
 		data = tvb_get_ptr(tvb, byte_offset, datalen + 1);
 
 		/* Do this allocation AFTER tvb_get_ptr() (which could throw an exception) */
@@ -390,7 +390,7 @@ tvb_clone(tvbuff_t *tvb)
 }
 
 guint
-tvb_length(const tvbuff_t *tvb)
+tvb_captured_length(const tvbuff_t *tvb)
 {
 	DISSECTOR_ASSERT(tvb && tvb->initialized);
 
@@ -398,7 +398,7 @@ tvb_length(const tvbuff_t *tvb)
 }
 
 gint
-tvb_length_remaining(const tvbuff_t *tvb, const gint offset)
+tvb_captured_length_remaining(const tvbuff_t *tvb, const gint offset)
 {
 	guint abs_offset, rem_length;
 	int exception;
@@ -413,7 +413,7 @@ tvb_length_remaining(const tvbuff_t *tvb, const gint offset)
 }
 
 guint
-tvb_ensure_length_remaining(const tvbuff_t *tvb, const gint offset)
+tvb_ensure_captured_length_remaining(const tvbuff_t *tvb, const gint offset)
 {
 	guint abs_offset, rem_length;
 	int   exception;
@@ -2475,16 +2475,6 @@ tvb_get_string_enc(wmem_allocator_t *scope, tvbuff_t *tvb, const gint offset,
 }
 
 /*
- * Get an ASCII string; this should not be used in new code.
- */
-guint8 *
-tvb_get_string(wmem_allocator_t *scope, tvbuff_t *tvb, const gint offset,
-			     const gint length)
-{
-	return tvb_get_ascii_string(scope, tvb, offset, length);
-}
-
-/*
  * These routines are like the above routines, except that they handle
  * null-terminated strings.  They find the length of that string (and
  * throw an exception if the tvbuff ends before we find the null), and
@@ -2949,7 +2939,7 @@ tvb_find_line_end(tvbuff_t *tvb, const gint offset, int len, gint *next_offset,
 	guchar found_needle = 0;
 
 	if (len == -1)
-		len = tvb_length_remaining(tvb, offset);
+		len = tvb_captured_length_remaining(tvb, offset);
 	/*
 	 * XXX - what if "len" is still -1, meaning "offset is past the
 	 * end of the tvbuff"?
@@ -3065,7 +3055,7 @@ tvb_find_line_end_unquoted(tvbuff_t *tvb, const gint offset, int len, gint *next
 	int      linelen;
 
 	if (len == -1)
-		len = tvb_length_remaining(tvb, offset);
+		len = tvb_captured_length_remaining(tvb, offset);
 	/*
 	 * XXX - what if "len" is still -1, meaning "offset is past the
 	 * end of the tvbuff"?
@@ -3203,7 +3193,7 @@ tvb_skip_wsp(tvbuff_t *tvb, const gint offset, const gint maxlength)
 	guint8 tempchar;
 
 	/* Get the length remaining */
-	tvb_len = tvb_length(tvb);
+	tvb_len = tvb_captured_length(tvb);
 	end     = offset + maxlength;
 	if (end >= tvb_len)
 	{
@@ -3238,7 +3228,7 @@ tvb_skip_guint8(tvbuff_t *tvb, int offset, const int maxlength, const guint8 ch)
 	int end, tvb_len;
 
 	/* Get the length remaining */
-	tvb_len = tvb_length(tvb);
+	tvb_len = tvb_captured_length(tvb);
 	end     = offset + maxlength;
 	if (end >= tvb_len)
 		end = tvb_len;
@@ -3294,7 +3284,7 @@ tvb_bcd_dig_to_wmem_packet_str(tvbuff_t *tvb, const gint offset, const gint len,
 		dgt = &Dgt1_9_bcd;
 
 	if (len == -1) {
-		length = tvb_length(tvb);
+		length = tvb_captured_length(tvb);
 		if (length < offset) {
 			return "";
 		}
diff --git a/epan/tvbuff.h b/epan/tvbuff.h
index be7db043f3..9e15612105 100644
--- a/epan/tvbuff.h
+++ b/epan/tvbuff.h
@@ -221,18 +221,29 @@ WS_DLL_PUBLIC tvbuff_t *tvb_new_composite(void);
 WS_DLL_PUBLIC void tvb_composite_finalize(tvbuff_t *tvb);
 
 
-/* Get total length of buffer */
-WS_DLL_PUBLIC guint tvb_length(const tvbuff_t *tvb);
+/* Get amount of captured data in the buffer (which is *NOT* necessarily the
+ * length of the packet). You probably want tvb_reported_length instead. */
+WS_DLL_PUBLIC guint tvb_captured_length(const tvbuff_t *tvb);
+
+/* DEPRECATED, do not use in new code, call tvb_captured_length directly! */
+#define tvb_length tvb_captured_length
 
 /** Computes bytes to end of buffer, from offset (which can be negative,
  * to indicate bytes from end of buffer). Function returns 0 if offset is
- * either at the end of the buffer or out of bounds. No exception is thrown. */
-WS_DLL_PUBLIC gint tvb_length_remaining(const tvbuff_t *tvb, const gint offset);
+ * either at the end of the buffer or out of bounds. No exception is thrown.
+ * You probably want tvb_reported_length_remaining instead. */
+WS_DLL_PUBLIC gint tvb_captured_length_remaining(const tvbuff_t *tvb, const gint offset);
+
+/* DEPRECATED, do not use in new code, call tvb_captured_length_remaining directly! */
+#define tvb_length_remaining tvb_captured_length_remaining
 
 /** Same as above, but throws an exception if the offset is out of bounds. */
-WS_DLL_PUBLIC guint tvb_ensure_length_remaining(const tvbuff_t *tvb,
+WS_DLL_PUBLIC guint tvb_ensure_captured_length_remaining(const tvbuff_t *tvb,
     const gint offset);
 
+/* DEPRECATED, do not use in new code, call tvb_ensure_captured_length_remaining directly! */
+#define tvb_ensure_length_remaining tvb_ensure_captured_length_remaining
+
 /* Checks (w/o throwing exception) that the bytes referred to by
  * 'offset'/'length' actually exist in the buffer */
 WS_DLL_PUBLIC gboolean tvb_bytes_exist(const tvbuff_t *tvb, const gint offset,
@@ -472,23 +483,20 @@ extern gchar *tvb_format_stringzpad_wsp(tvbuff_t *tvb, const gint offset,
  *
  * Throws an exception if the tvbuff ends before the string does.
  *
- * tvb_get_string() handles 7-bit ASCII strings, with characters
- *                   with the 8th bit set are converted to the
- *                   Unicode REPLACEMENT CHARACTER.
+ * Takes a string encoding as well, and converts to UTF-8 from the encoding,
+ * possibly mapping some characters to the Unicode REPLACEMENT CHARACTER.
  *
- * tvb_get_string_enc() takes a string encoding as well, and converts to UTF-8
- *                   from the encoding, possibly mapping some characters
- *                   to the REPLACEMENT CHARACTER.
- *
- * If scope is set to NULL it is the user's responsibility to g_free()
- * the memory allocated by tvb_memdup(). Otherwise memory is
- * automatically freed when the scope lifetime is reached.
+ * If scope is set to NULL it is the user's responsibility to wmem_free()
+ * the memory allocated. Otherwise memory is automatically freed when the scope
+ * lifetime is reached.
  */
-WS_DLL_PUBLIC guint8 *tvb_get_string(wmem_allocator_t *scope, tvbuff_t *tvb,
-    const gint offset, const gint length);
 WS_DLL_PUBLIC guint8 *tvb_get_string_enc(wmem_allocator_t *scope,
     tvbuff_t *tvb, const gint offset, const gint length, const guint encoding);
 
+/* DEPRECATED, do not use in new code, call tvb_get_string_enc directly! */
+#define tvb_get_string(SCOPE, TVB, OFFSET, LENGTH) \
+    tvb_get_string_enc(SCOPE, TVB, OFFSET, LENGTH, ENC_ASCII)
+
 /**
  * Given a tvbuff, a bit offset, and a number of characters, allocate
  * a buffer big enough to hold a non-null-terminated string of no_of_chars