Adding upstream version 4.2.2.upstream/4.2.2

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 273 insertions, 0 deletions

diff --git a/epan/dissectors/packet-vssmonitoring.c b/epan/dissectors/packet-vssmonitoring.c
new file mode 100644
index 00000000..fa5f5e53
--- /dev/null
+++ b/epan/dissectors/packet-vssmonitoring.c
@@ -0,0 +1,273 @@
+/* packet-vssmonitoring.c
+ * Routines for dissection of VSS Monitoring timestamp and portstamp
+ *
+ * Copyright VSS Monitoring 2011
+ *
+ * 20111205 - First edition by Sake Blok (sake.blok@SYN-bit.nl)
+ *
+ * Wireshark - Network traffic analyzer
+ * By Gerald Combs <gerald@wireshark.org>
+ * Copyright 1998 Gerald Combs
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "config.h"
+
+#include <epan/packet.h>
+#include <epan/prefs.h>
+
+
+#define VSS_NS_MASK     0x3fffffff
+#define CLKSRC_SHIFT    30
+
+#define CLKSRC_LOCAL    0
+#define CLKSRC_NTP      1
+#define CLKSRC_GPS      2
+#define CLKSRC_PTP      3
+
+static const value_string clksrc_vals[] = {
+  { CLKSRC_LOCAL,       "Not Synced" },
+  { CLKSRC_NTP,         "NTP" },
+  { CLKSRC_GPS,         "GPS" },
+  { CLKSRC_PTP,         "PTP" },
+  { 0,                  NULL }
+};
+
+void proto_register_vssmonitoring(void);
+void proto_reg_handoff_vssmonitoring(void);
+
+static int proto_vssmonitoring = -1;
+
+static int hf_vssmonitoring_time = -1;
+static int hf_vssmonitoring_clksrc = -1;
+static int hf_vssmonitoring_srcport = -1;
+
+static gint ett_vssmonitoring = -1;
+
+static gboolean vss_dissect_portstamping_only = FALSE;
+static gboolean vss_two_byte_portstamps = FALSE;
+
+static int
+dissect_vssmonitoring(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_)
+{
+  proto_tree    *ti = NULL;
+  proto_tree    *vssmonitoring_tree = NULL;
+  guint         offset = 0;
+
+  guint         trailer_len;
+  guint         portstamp_len = (vss_two_byte_portstamps) ? 2 : 1;
+  nstime_t      vssmonitoring_time;
+  guint8        vssmonitoring_clksrc = 0;
+  guint32       vssmonitoring_srcport = 0;
+
+  struct tm     *tmp;
+
+
+  /* First get the length of the trailer */
+  trailer_len = tvb_reported_length(tvb);
+
+  /* The trailer length is a sum (of any combination) of:
+   * timestamp (8 bytes)
+   * port stamp (1 or 2 bytes)
+   * fcs (4 bytes)
+   *
+   * Our caller might pass in the trailer with FCS included, so we check for
+   * a trailer with a length that includes one or more of a time stamp,
+   * a 1-byte or 2-byte port stamp, and optionally an FCS.
+   *
+   * See
+   *
+   *    https://web.archive.org/web/20160402091604/http://www.vssmonitoring.com/resources/feature-brief/Port-and-Time-Stamping.pdf
+   *
+   * which speaks of 2-byte port stamps as being for a "future release".
+   *
+   * Iris Packet Broker user manuals when VSS Monitoring was owned by
+   * Tektronix also mentioned only a 1-byte port stamp.
+   *
+   * VSS Monitoring has since been acquired by NetScout.
+   * Products released in 2019:
+   * https://www.netscout.com/sites/default/files/2019-01/PFSPDS_002_EN-1803-nGenius-4200-Series-Packet-Flow-Switch.pdf
+   * https://www.netscout.com/sites/default/files/2019-12/PFSPDS_003_EN-1901%20-%20nGenius%206010%20Packet%20Flow%20Switch.pdf
+   * mention both Port Stamping and VLAN tagging under "traffic port tagging,"
+   * and also note separately that up to _256_ ports can be meshed together
+   * across hardware to act as a single device.
+   *
+   * Products released in 2021:
+   * https://www.netscout.com/sites/default/files/2021-07/PFSPDS_021_EN-2102%20-%20nGenius%207000%20Series%20Packet%20Flow%20Switches.pdf
+   * https://www.netscout.com/sites/default/files/2021-07/PFSPDS_022_EN-2102%20-%20nGenius%205000%20Series%20Packet%20Flow%20Switches.pdf
+   * mention only VLAN tagging, and not Port Stamping in the port tagging
+   * feature section.
+   *
+   * VSS Monitoring has apparently never released a product with 2 byte
+   * port stamps, and it seems going forward that port stamping is going
+   * to be deprecrated in favor of VLAN tagging.
+   *
+   * So by default we'll assume port stamps are 1 byte, with 2 bytes
+   * port stamps supported via preference (disabled by default.)
+   *
+   * This means a trailer length must not be more than 14 bytes,
+   * and:
+   *
+   *    must not be 3 modulo 4 (as it can't have both a 1-byte
+   *    and a 2-byte port stamp);
+   *
+   *    can only be either 1 or 2 module 4, depending on the size
+   *    of port stamp we accept;
+   *
+   *    if it's less than 8 bytes, must not be 0 modulo 4 (as
+   *    it must have a 1-byte or 2-byte port stamp, given that
+   *    it has no timestamp).
+   */
+  if ( trailer_len > 12 + portstamp_len )
+    return 0;
+
+  if ( (trailer_len & 3) != 0 && (trailer_len & 3) != portstamp_len )
+    return 0;
+
+  /*
+   * If we have a time stamp, check it for validity.
+   */
+  if ( trailer_len >= 8 ) {
+    vssmonitoring_time.secs  = tvb_get_ntohl(tvb, offset);
+    vssmonitoring_time.nsecs = tvb_get_ntohl(tvb, offset + 4);
+    vssmonitoring_clksrc     = (guint8)(((guint32)vssmonitoring_time.nsecs) >> CLKSRC_SHIFT);
+    vssmonitoring_time.nsecs &= VSS_NS_MASK;
+
+      /* Probably padding passed to this dissector (e.g., a 802.1Q tagged
+       * packet where the minimum frame length was increased to account
+       * for the tag, see IEEE Std 802.1Q-2014 G.2.3 "Minimum PDU Size")
+       * FIXME: Should be made even stricter.
+       */
+      if (vssmonitoring_time.secs == 0)
+        return 0;
+      /* The timestamp will be based on the uptime until the TAP is completely
+       * booted, this takes about 60s, but use 1 hour to be sure
+       */
+      if (vssmonitoring_time.secs > 3600) {
+
+        /* Check whether the timestamp in the PCAP header and the VSS-Monitoring
+         * differ less than 30 days, otherwise, this might not be a VSS-Monitoring
+         * timestamp
+         */
+        if ( vssmonitoring_time.secs > pinfo->abs_ts.secs ) {
+          if ( vssmonitoring_time.secs - pinfo->abs_ts.secs > 2592000 ) /* 30 days */
+            return 0;
+        } else {
+          if ( pinfo->abs_ts.secs - vssmonitoring_time.secs > 2592000 ) /* 30 days */
+            return 0;
+        }
+      }
+
+      /* The nanoseconds field should be less than 1000000000
+       */
+      if ( vssmonitoring_time.nsecs >= 1000000000 )
+        return 0;
+  } else if (!vss_dissect_portstamping_only || (trailer_len & 3) == 0) {
+    /* No timestamp, so we need a port stamp and be willing to accept
+     * packets with port stamping but not time stamping.
+     *
+     * Unfortunately, the port stamp can be zero or any other value, so
+     * this means that a one-byte or two-byte all-zero trailer that's just
+     * padding can be misinterpreted as a VSS monitoring trailer, among
+     * other false positives, so we disable that by default.
+     */
+    return 0;
+  }
+
+  /* All systems are go, lets dissect the VSS-Monitoring trailer */
+  if (tree) {
+    ti = proto_tree_add_item(tree, proto_vssmonitoring,
+             tvb, 0, (trailer_len & 0xb), ENC_NA);
+    vssmonitoring_tree = proto_item_add_subtree(ti, ett_vssmonitoring);
+  }
+
+  /* Do we have a timestamp? */
+  if ( trailer_len >= 8 ) {
+    if (tree) {
+      proto_tree_add_time(vssmonitoring_tree, hf_vssmonitoring_time, tvb, offset, 8, &vssmonitoring_time);
+      proto_tree_add_uint(vssmonitoring_tree, hf_vssmonitoring_clksrc, tvb, offset + 4, 1, vssmonitoring_clksrc);
+
+      tmp = localtime(&vssmonitoring_time.secs);
+      if (tmp)
+        proto_item_append_text(ti, ", Timestamp: %02d:%02d:%02d.%09ld",
+            tmp->tm_hour, tmp->tm_min, tmp->tm_sec,(long)vssmonitoring_time.nsecs);
+      else
+        proto_item_append_text(ti, ", Timestamp: <Not representable>");
+    }
+    offset += 8;
+  }
+
+  /* Do we have a port stamp? */
+  if ( (trailer_len & 3) == portstamp_len) {
+    if (tree) {
+      proto_tree_add_item_ret_uint(vssmonitoring_tree, hf_vssmonitoring_srcport, tvb, offset, portstamp_len, ENC_BIG_ENDIAN, &vssmonitoring_srcport);
+      proto_item_append_text(ti, ", Source Port: %d", vssmonitoring_srcport);
+    }
+    offset += portstamp_len;
+  }
+
+  return offset;
+}
+
+void
+proto_register_vssmonitoring(void)
+{
+  static hf_register_info hf[] = {
+    { &hf_vssmonitoring_time, {
+        "Time Stamp", "vssmonitoring.time",
+        FT_ABSOLUTE_TIME, ABSOLUTE_TIME_LOCAL, NULL, 0x0,
+        "VSS Monitoring Time Stamp", HFILL }},
+
+    { &hf_vssmonitoring_clksrc, {
+        "Clock Source", "vssmonitoring.clksrc",
+        FT_UINT8, BASE_DEC, VALS(clksrc_vals), 0x0,
+        "VSS Monitoring Clock Source", HFILL }},
+
+    { &hf_vssmonitoring_srcport, {
+        "Src Port", "vssmonitoring.srcport",
+        FT_UINT16, BASE_DEC, NULL, 0x0,
+        "VSS Monitoring Source Port", HFILL }}
+  };
+
+  static gint *ett[] = {
+    &ett_vssmonitoring
+  };
+
+  module_t *vssmonitoring_module;
+
+  proto_vssmonitoring = proto_register_protocol("VSS Monitoring Ethernet trailer", "VSS Monitoring", "vssmonitoring");
+  proto_register_field_array(proto_vssmonitoring, hf, array_length(hf));
+  proto_register_subtree_array(ett, array_length(ett));
+
+  vssmonitoring_module = prefs_register_protocol(proto_vssmonitoring, NULL);
+
+  prefs_register_obsolete_preference(vssmonitoring_module, "use_heuristics");
+  prefs_register_bool_preference(vssmonitoring_module, "dissect_portstamping_only",
+      "Dissect trailers with only port stamping",
+      "Whether the VSS Monitoring dissector should attempt to dissect trailers with no timestamp, only port stamping.  Note that this can result in a large number of false positives.",
+      &vss_dissect_portstamping_only);
+  prefs_register_bool_preference(vssmonitoring_module, "two_byte_portstamps",
+      "Two byte port stamps",
+      "Whether the VSS Monitoring dissector should assume that the port stamp is two bytes, instead of the standard one byte.",
+      &vss_two_byte_portstamps);
+}
+
+void
+proto_reg_handoff_vssmonitoring(void)
+{
+  heur_dissector_add("eth.trailer", dissect_vssmonitoring, "VSS Monitoring ethernet trailer", "vssmonitoring_eth", proto_vssmonitoring, HEURISTIC_ENABLE);
+}
+
+/*
+ * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
+ *
+ * Local Variables:
+ * c-basic-offset: 2
+ * tab-width: 8
+ * indent-tabs-mode: nil
+ * End:
+ *
+ * ex: set shiftwidth=2 tabstop=8 expandtab:
+ * :indentSize=2:tabSize=8:noTabs=true:
+ */