Add support for cloning TVBs, move tvb_new() prototype to wtap-int.h

svn path=/trunk/; revision=50558

1 files changed, 169 insertions, 9 deletions

diff --git a/frame_tvbuff.c b/frame_tvbuff.c
index 5af5b3bc23..20635fd958 100644
--- a/frame_tvbuff.c
+++ b/frame_tvbuff.c
@@ -31,16 +31,119 @@
 #include <epan/tvbuff.h>
 
 #include "frame_tvbuff.h"
+#include "globals.h"
 
-/* XXX, to read data with wtap_seek_read() we need: 
- *    cf->wth, fdata->file_off, fdata->cap_len 
- *    add when ready to structure below
- */
+#include "wtap-int.h" /* for ->random_fh */
 
 struct tvb_frame {
 	struct tvbuff tvb;
+
+	Buffer *buf;         /* Packet data */
+
+	wtap *wth;           /**< Wiretap session */
+	gint64 file_off;     /**< File offset */
+
+	guint offset;
 };
 
+static gboolean
+frame_read(struct tvb_frame *frame_tvb, struct wtap_pkthdr *phdr, Buffer *buf)
+{
+	int    err;
+	gchar *err_info;
+
+	/* sanity check, capture file was closed? */
+	if (cfile.wth != frame_tvb->wth)
+		return FALSE;
+
+	if (!wtap_seek_read(frame_tvb->wth, frame_tvb->file_off, phdr, buf, frame_tvb->tvb.length, &err, &err_info)) {
+		switch (err) {
+			case WTAP_ERR_UNSUPPORTED_ENCAP:
+			case WTAP_ERR_BAD_FILE:
+				g_free(err_info);
+				break;
+		}
+		return FALSE;
+	}
+	return TRUE;
+}
+
+
+static void
+frame_invalidate(struct tvb_frame *frame_tvb)
+{
+	struct wtap_pkthdr phdr; /* Packet header */
+
+	if (frame_tvb->buf == NULL) {
+		frame_tvb->buf = (struct Buffer *) g_malloc(sizeof(struct Buffer));
+
+		/* XXX, register frame_tvb to some list which frees from time to time not used buffers :] */
+		buffer_init(frame_tvb->buf, frame_tvb->tvb.length);
+
+		if (!frame_read(frame_tvb, &phdr, frame_tvb->buf))
+			{ /* TODO: THROW(???); */ }
+	}
+
+	frame_tvb->tvb.real_data = buffer_start_ptr(frame_tvb->buf);
+}
+
+static void
+frame_free(tvbuff_t *tvb)
+{
+	struct tvb_frame *frame_tvb = (struct tvb_frame *) tvb;
+
+	if (frame_tvb->buf) {
+		buffer_free(frame_tvb->buf);
+
+		g_free(frame_tvb->buf);
+	}
+}
+
+static const guint8 *
+frame_get_ptr(tvbuff_t *tvb, guint abs_offset, guint abs_length _U_)
+{
+	struct tvb_frame *frame_tvb = (struct tvb_frame *) tvb;
+
+	frame_invalidate(frame_tvb);
+
+	return tvb->real_data + abs_offset;
+}
+
+static void *
+frame_memcpy(tvbuff_t *tvb, void *target, guint abs_offset, guint abs_length)
+{
+	struct tvb_frame *frame_tvb = (struct tvb_frame *) tvb;
+
+	frame_invalidate(frame_tvb);
+
+	return memcpy(target, tvb->real_data + abs_offset, abs_length);
+}
+
+static gint
+frame_find_guint8(tvbuff_t *tvb, guint abs_offset, guint limit, guint8 needle)
+{
+	struct tvb_frame *frame_tvb = (struct tvb_frame *) tvb;
+	const guint8 *result;
+
+	frame_invalidate(frame_tvb);
+
+	result = (const guint8 *)memchr(tvb->real_data + abs_offset, needle, limit);
+	if (result)
+		return (gint) (result - tvb->real_data);
+	else
+		return -1;
+}
+
+static gint
+frame_pbrk_guint8(tvbuff_t *tvb, guint abs_offset, guint limit, const guint8 *needles, guchar *found_needle)
+{
+	struct tvb_frame *frame_tvb = (struct tvb_frame *) tvb;
+
+	frame_invalidate(frame_tvb);
+
+	return tvb_pbrk_guint8(tvb, abs_offset, limit, needles, found_needle);
+}
+
 static gsize
 frame_sizeof(void)
 { 
@@ -50,23 +153,28 @@ frame_sizeof(void)
 static guint
 frame_offset(const tvbuff_t *tvb _U_, const guint counter)
 {
+	/* XXX: frame_tvb->offset */
 	return counter;
 }
 
+static tvbuff_t *frame_clone(tvbuff_t *tvb, guint abs_offset, guint abs_length);
+
 static const struct tvb_ops tvb_frame_ops = {
 	frame_sizeof,         /* size */
-	NULL,                 /* free */
+	frame_free,           /* free */
 	frame_offset,         /* offset */
-	NULL,                 /* get_ptr */
-	NULL,                 /* memcpy */
-	NULL,                 /* find_guint8 */
-	NULL,                 /* pbrk_guint8 */
+	frame_get_ptr,        /* get_ptr */
+	frame_memcpy,         /* memcpy */
+	frame_find_guint8,    /* find_guint8 */
+	frame_pbrk_guint8,    /* pbrk_guint8 */
+	frame_clone,          /* clone */
 };
 
 /* based on tvb_new_real_data() */
 tvbuff_t *
 frame_tvbuff_new(const frame_data *fd, const guint8 *buf)
 {
+	struct tvb_frame *frame_tvb;
 	tvbuff_t *tvb;
 
 	tvb = tvb_new(&tvb_frame_ops);
@@ -104,6 +212,21 @@ frame_tvbuff_new(const frame_data *fd, const guint8 *buf)
 	 */
 	tvb->ds_tvb = tvb;
 
+	frame_tvb = (struct tvb_frame *) tvb;
+
+	/* XXX, how to handle fd->file_off == -1 (edited packet) ?? */
+	/* don't care, reassemble code was doing whole copy of data, so it'll work the same */
+
+	/* XXX, wtap_can_seek() */
+	if (fd && cfile.wth && cfile.wth->random_fh) {
+		frame_tvb->wth = cfile.wth;
+		frame_tvb->file_off = fd->file_off;
+		frame_tvb->offset = 0;
+	} else
+		frame_tvb->wth = NULL;
+
+	frame_tvb->buf = NULL;
+
 	return tvb;
 }
 
@@ -112,3 +235,40 @@ frame_tvbuff_new_buffer(const frame_data *fd, Buffer *buf)
 {
 	return frame_tvbuff_new(fd, buffer_start_ptr(buf));
 }
+
+static tvbuff_t *
+frame_clone(tvbuff_t *tvb, guint abs_offset, guint abs_length)
+{
+	struct tvb_frame *frame_tvb = (struct tvb_frame *) tvb;
+
+	tvbuff_t *cloned_tvb;
+	struct tvb_frame *cloned_frame_tvb;
+
+	/* file not seekable */
+	if (!frame_tvb->wth)
+		return NULL;
+
+	abs_offset += frame_tvb->offset;
+
+	cloned_tvb = tvb_new(&tvb_frame_ops);
+
+	/* data will be read when needed */
+	cloned_tvb->real_data       = NULL;
+	cloned_tvb->length          = abs_length;
+	cloned_tvb->reported_length = abs_length; /* XXX? */
+	cloned_tvb->initialized     = TRUE;
+
+	/*
+	 * This is the top-level real tvbuff for this data source,
+	 * so its data source tvbuff is itself.
+	 */
+	cloned_tvb->ds_tvb = cloned_tvb;
+
+	cloned_frame_tvb = (struct tvb_frame *) cloned_tvb;
+	cloned_frame_tvb->wth = frame_tvb->wth;
+	cloned_frame_tvb->file_off = frame_tvb->file_off;
+	cloned_frame_tvb->offset = abs_offset;
+	cloned_frame_tvb->buf = NULL;
+
+	return cloned_tvb;
+}