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Diffstat (limited to 'epan/dissectors/packet-tcp.c')
-rw-r--r--epan/dissectors/packet-tcp.c118
1 files changed, 88 insertions, 30 deletions
diff --git a/epan/dissectors/packet-tcp.c b/epan/dissectors/packet-tcp.c
index 83b0447ad5..f61e3bb12b 100644
--- a/epan/dissectors/packet-tcp.c
+++ b/epan/dissectors/packet-tcp.c
@@ -233,7 +233,7 @@ static int hf_tcp_option_ao_mac = -1;
static int hf_tcp_option_qs_rate = -1;
static int hf_tcp_option_qs_ttl_diff = -1;
static int hf_tcp_option_exp_data = -1;
-static int hf_tcp_option_exp_magic_number = -1;
+static int hf_tcp_option_exp_exid = -1;
static int hf_tcp_option_unknown_payload = -1;
static int hf_tcp_option_rvbd_probe_version1 = -1;
@@ -469,13 +469,14 @@ static gboolean tcp_no_subdissector_on_error = TRUE;
static gboolean tcp_reassemble_out_of_order = FALSE;
/*
- * FF: (draft-ietf-tcpm-experimental-options-03)
+ * FF: https://www.rfc-editor.org/rfc/rfc6994.html
* With this flag set we assume the option structure for experimental
- * codepoints (253, 254) has a magic number field (first field after the
- * Kind and Length). The magic number is used to differentiate different
- * experiments and thus will be used in data dissection.
+ * codepoints (253, 254) has an Experiment Identifier (ExID), which is
+ * the first 16-bit field after the Kind and Length.
+ * The ExID is used to differentiate different experiments and thus will
+ * be used in data dissection.
*/
-static gboolean tcp_exp_options_with_magic = TRUE;
+static gboolean tcp_exp_options_rfc6994 = TRUE;
/*
* This flag indicates which of Fast Retransmission or Out-of-Order
@@ -547,7 +548,28 @@ static gboolean read_seq_as_syn_cookie = FALSE;
#define TCPOLEN_TFO_MIN 2
#define TCPOLEN_RVBD_PROBE_MIN 3
#define TCPOLEN_RVBD_TRPY_MIN 16
-#define TCPOLEN_EXP_MIN 2
+#define TCPOLEN_EXP_MIN 4
+
+/*
+ * TCP Experimental Option Experiment Identifiers (TCP ExIDs)
+ * See: https://www.iana.org/assignments/tcp-parameters/tcp-parameters.xhtml#tcp-exids
+ * Wireshark only supports 16-bit ExIDs
+ */
+
+#define TCPEXID_TARR 0x00ac
+#define TCPEXID_HOST_ID 0x0348
+#define TCPEXID_ASC 0x0a0d
+#define TCPEXID_CAPABILITY 0x0ca0
+#define TCPEXID_EDO 0x0ed0
+#define TCPEXID_ENO 0x454e
+#define TCPEXID_SNO 0x5323
+#define TCPEXID_TS_INTERVAL 0x75ec /* 32-bit ExID: 0x75ecffee */
+#define TCPEXID_ACC_ECN_0 0xacc0
+#define TCPEXID_ACC_ECN_1 0xacc1
+#define TCPEXID_ACC_ECN 0xacce
+#define TCPEXID_SMC_R 0xe2d4 /* 32-bit ExID: 0xe2d4c3d9 */
+#define TCPEXID_FO 0xf989
+#define TCPEXID_LOW_LATENCY 0xf990
/*
* Multipath TCP subtypes
@@ -617,6 +639,24 @@ static const value_string tcp_option_kind_vs[] = {
};
static value_string_ext tcp_option_kind_vs_ext = VALUE_STRING_EXT_INIT(tcp_option_kind_vs);
+static const value_string tcp_exid_vs[] = {
+ { TCPEXID_TARR, "TCP ACK Rate Request" },
+ { TCPEXID_HOST_ID, "Host ID" },
+ { TCPEXID_ASC, "Autonomous System Compensation" },
+ { TCPEXID_CAPABILITY, "Capability Option" },
+ { TCPEXID_EDO, "Extended Data Offset" },
+ { TCPEXID_ENO, "Encryption Negotiation" },
+ { TCPEXID_SNO, "Service Number" },
+ { TCPEXID_TS_INTERVAL, "Timestamp Interval" },
+ { TCPEXID_ACC_ECN_0, "Accurate ECN - Order 0" },
+ { TCPEXID_ACC_ECN_1, "Accurate ECN - Order 1" },
+ { TCPEXID_ACC_ECN, "Accurate ECN" },
+ { TCPEXID_SMC_R, "Shared Memory communications over RMDA protocol" },
+ { TCPEXID_FO, "Fast Open" },
+ { TCPEXID_LOW_LATENCY, "Low Latency" },
+ { 0, NULL }
+};
+
/* not all of the hf_fields below make sense for TCP but we have to provide
them anyways to comply with the API (which was aimed for IP fragment
reassembly) */
@@ -4728,6 +4768,12 @@ tcp_info_append_uint(packet_info *pinfo, const char *abbrev, guint32 val)
col_append_str_uint(pinfo->cinfo, COL_INFO, abbrev, val, " ");
}
+static void
+tcp_info_append_hex_uint(packet_info *pinfo, const char *abbrev, guint32 val)
+{
+ col_append_fstr(pinfo->cinfo, COL_INFO, " %s=%X", abbrev, val);
+}
+
static gboolean
tcp_option_len_check(proto_item* length_item, packet_info *pinfo, guint len, guint optlen)
{
@@ -4842,32 +4888,44 @@ dissect_tcpopt_tfo(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* da
static int
dissect_tcpopt_exp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
{
- proto_item *item;
+ proto_item *length_item, *item;
proto_tree *exp_tree;
- guint16 magic;
+ guint16 exid;
+ guint8 kind;
gint offset = 0, optlen = tvb_reported_length(tvb);
item = proto_tree_add_item(tree, proto_tcp_option_exp, tvb, offset, -1, ENC_NA);
exp_tree = proto_item_add_subtree(item, ett_tcp_option_exp);
-
proto_tree_add_item(exp_tree, hf_tcp_option_kind, tvb, offset, 1, ENC_BIG_ENDIAN);
- proto_tree_add_item(exp_tree, hf_tcp_option_len, tvb, offset + 1, 1, ENC_BIG_ENDIAN);
- if (tcp_exp_options_with_magic && ((optlen - 2) > 0)) {
- magic = tvb_get_ntohs(tvb, offset + 2);
- proto_tree_add_item(exp_tree, hf_tcp_option_exp_magic_number, tvb,
- offset + 2, 2, ENC_BIG_ENDIAN);
- switch (magic) {
- case 0xf989: /* RFC7413, TCP Fast Open */
- dissect_tcpopt_tfo_payload(tvb, offset+2, optlen-2, pinfo, exp_tree, data);
- break;
- default:
- /* Unknown magic number */
- break;
+ kind = tvb_get_guint8(tvb, offset);
+ length_item = proto_tree_add_item(exp_tree, hf_tcp_option_len, tvb, offset + 1, 1, ENC_BIG_ENDIAN);
+ if (tcp_exp_options_rfc6994) {
+ if (optlen >= TCPOLEN_EXP_MIN) {
+ exid = tvb_get_ntohs(tvb, offset + 2);
+ proto_tree_add_item(exp_tree, hf_tcp_option_exp_exid, tvb,
+ offset + 2, 2, ENC_BIG_ENDIAN);
+ proto_item_append_text(item, ": %s", val_to_str_const(exid, tcp_exid_vs, "Unknown"));
+ switch (exid) {
+ case TCPEXID_FO:
+ dissect_tcpopt_tfo_payload(tvb, offset + 2, optlen - 2, pinfo, exp_tree, data);
+ break;
+ default:
+ if (optlen > TCPOLEN_EXP_MIN) {
+ proto_tree_add_item(exp_tree, hf_tcp_option_exp_data, tvb,
+ offset + TCPOLEN_EXP_MIN,
+ optlen - TCPOLEN_EXP_MIN, ENC_NA);
+ }
+ tcp_info_append_hex_uint(pinfo, "ExID", exid);
+ break;
+ }
+ } else {
+ expert_add_info_format(pinfo, length_item, &ei_tcp_opt_len_invalid,
+ "option length %u smaller than 4", optlen);
}
} else {
proto_tree_add_item(exp_tree, hf_tcp_option_exp_data, tvb,
offset + 2, optlen - 2, ENC_NA);
- tcp_info_append_uint(pinfo, "Expxx", TRUE);
+ tcp_info_append_uint(pinfo, "Exp", (kind == TCPOPT_EXP_FD) ? 1 : 2);
}
return tvb_captured_length(tvb);
}
@@ -8256,9 +8314,9 @@ proto_register_tcp(void)
{ "Data", "tcp.options.experimental.data", FT_BYTES,
BASE_NONE, NULL, 0x0, NULL, HFILL}},
- { &hf_tcp_option_exp_magic_number,
- { "Magic Number", "tcp.options.experimental.magic_number", FT_UINT16,
- BASE_HEX, NULL, 0x0, NULL, HFILL}},
+ { &hf_tcp_option_exp_exid,
+ { "Experiment Identifier", "tcp.options.experimental.exid", FT_UINT16,
+ BASE_HEX, &tcp_exid_vs, 0x0, NULL, HFILL}},
{ &hf_tcp_option_unknown_payload,
{ "Payload", "tcp.options.unknown.payload", FT_BYTES,
@@ -9118,10 +9176,10 @@ proto_register_tcp(void)
"Do not call any subdissectors for Retransmitted or OutOfOrder segments",
&tcp_no_subdissector_on_error);
- prefs_register_bool_preference(tcp_module, "dissect_experimental_options_with_magic",
- "TCP Experimental Options with a Magic Number",
- "Assume TCP Experimental Options (253, 254) have a Magic Number and use it for dissection",
- &tcp_exp_options_with_magic);
+ prefs_register_bool_preference(tcp_module, "dissect_experimental_options_rfc6994",
+ "TCP Experimental Options using the format of RFC 6994",
+ "Assume TCP Experimental Options (253, 254) have an Experiment Identifier and use it for dissection",
+ &tcp_exp_options_rfc6994);
prefs_register_bool_preference(tcp_module, "display_process_info_from_ipfix",
"Display process information via IPFIX",
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-27 17:02:19 +0000