From e4ba6dbc3f1e76890b22773807ea37fe8fa2b1bc Mon Sep 17 00:00:00 2001
From: Daniel Baumann <daniel.baumann@progress-linux.org>
Date: Wed, 10 Apr 2024 22:34:10 +0200
Subject: Adding upstream version 4.2.2.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
---
 epan/tvbuff_zstd.c | 110 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 110 insertions(+)
 create mode 100644 epan/tvbuff_zstd.c

(limited to 'epan/tvbuff_zstd.c')

diff --git a/epan/tvbuff_zstd.c b/epan/tvbuff_zstd.c
new file mode 100644
index 0000000..0ce65c0
--- /dev/null
+++ b/epan/tvbuff_zstd.c
@@ -0,0 +1,110 @@
+/* tvbuff_zstd.c
+ * Copyright 2022, Kevin Albertson <kevin.eric.albertson [AT] gmail.com>
+ *
+ * Wireshark - Network traffic analyzer
+ * By Gerald Combs <gerald@wireshark.org>
+ * Copyright 1998 Gerald Combs
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+/*
+ * Decompress ZSTD: http://facebook.github.io/zstd/
+ */
+
+#include "config.h"
+
+#ifdef HAVE_ZSTD
+#include <zstd.h>
+#endif
+
+#include "proto.h" // DISSECTOR_ASSERT_HINT
+#include "tvbuff.h"
+
+#include "tvbuff-int.h" // tvb_add_to_chain
+
+#define MAX_LOOP_ITERATIONS 100
+
+tvbuff_t *tvb_uncompress_zstd(tvbuff_t *tvb, const int offset, int comprlen)
+{
+#ifndef HAVE_ZSTD
+    // Cast to void to silence unused warnings.
+    (void)tvb;
+    (void)offset;
+    (void)comprlen;
+    return NULL;
+#else
+    ZSTD_inBuffer input = {tvb_memdup(NULL, tvb, offset, comprlen), comprlen, 0};
+    ZSTD_DStream *zds = ZSTD_createDStream();
+    size_t rc = 0;
+    uint8_t *uncompr = NULL;
+    size_t uncompr_len = 0;
+    bool ok = false;
+    int count = 0;
+
+    // ZSTD does not consume the last byte of the frame until it has flushed all of the decompressed data of the frame.
+    // Therefore, loop while there is more input.
+    ZSTD_outBuffer output = {g_malloc(ZSTD_DStreamOutSize()), ZSTD_DStreamOutSize(), 0};
+    while (input.pos < input.size && count < MAX_LOOP_ITERATIONS)
+    {
+        rc = ZSTD_decompressStream(zds, &output, &input);
+        if (ZSTD_isError(rc))
+        {
+            goto end;
+        }
+
+        if (output.pos > 0)
+        {
+            if (!uncompr)
+            {
+                DISSECTOR_ASSERT (uncompr_len == 0);
+                uncompr = g_malloc(output.pos);
+            } else {
+                uncompr = g_realloc(uncompr, uncompr_len + output.pos);
+            }
+            memcpy (uncompr + uncompr_len, output.dst, output.pos);
+            uncompr_len += output.pos;
+            // Reset the output buffer.
+            output.pos = 0;
+        }
+        count++;
+        DISSECTOR_ASSERT_HINT(count < MAX_LOOP_ITERATIONS, "MAX_LOOP_ITERATIONS exceeded");
+    }
+    if (rc > 0)
+    {
+        // There is extra data that was not decompressed.
+        goto end;
+    }
+
+    ok = true;
+end:
+    g_free((void *)output.dst);
+    wmem_free(NULL, (void *)input.src);
+    ZSTD_freeDStream(zds);
+    if (ok)
+    {
+        tvbuff_t *uncompr_tvb;
+        uncompr_tvb = tvb_new_real_data (uncompr, (guint)uncompr_len, (guint)uncompr_len);
+        tvb_set_free_cb (uncompr_tvb, g_free);
+        return uncompr_tvb;
+    }
+
+    if (uncompr)
+    {
+        g_free (uncompr);
+    }
+
+    return NULL;
+#endif /* HAVE_ZSTD */
+}
+
+tvbuff_t *tvb_child_uncompress_zstd(tvbuff_t *parent, tvbuff_t *tvb, const int offset, int comprlen)
+{
+    tvbuff_t *uncompressed = tvb_uncompress_zstd(tvb, offset, comprlen);
+    if (!uncompressed)
+    {
+        return uncompressed;
+    }
+    tvb_add_to_chain(parent, uncompressed);
+    return uncompressed;
+}
-- 
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