Merge pull request #918 from dcaratti/gh189

mptcp: add support for MP_TCPRST

Author: mcr

print-mptcp.c

@@ -56,6 +56,7 @@
 #define MPTCP_SUB_PRIO 0x5
 #define MPTCP_SUB_FAIL 0x6
 #define MPTCP_SUB_FCLOSE 0x7
+#define MPTCP_SUB_TCPRST 0x8
 
 struct mptcp_option {
  nd_uint8_t kind;
@@ -182,6 +183,32 @@ struct mp_prio {
 
 #define MP_PRIO_B 0x01
 
+static const struct tok mp_tcprst_flags[] = {
+ { 0x08, "U" },
+ { 0x04, "V" },
+ { 0x02, "W" },
+ { 0x01, "T" },
+ { 0, NULL }
+};
+
+static const struct tok mp_tcprst_reasons[] = {
+ { 0x06, "Middlebox interference" },
+ { 0x05, "Unacceptable performance" },
+ { 0x04, "Too much outstanding data" },
+ { 0x03, "Administratively prohibited" },
+ { 0x02, "Lack of resources" },
+ { 0x01, "MPTCP-specific error" },
+ { 0x00, "Unspecified error" },
+ { 0, NULL }
+};
+
+struct mp_tcprst {
+ nd_uint8_t kind;
+ nd_uint8_t len;
+ nd_uint8_t sub_b;
+ nd_uint8_t reason;
+};
+
 static int
 dummy_print(netdissect_options *ndo _U_,
  const u_char *opt _U_, u_int opt_len _U_, u_char flags _U_)
@@ -454,6 +481,23 @@ mp_fast_close_print(netdissect_options *ndo,
  return 1;
 }
 
+static int
+mp_tcprst_print(netdissect_options *ndo,
+ const u_char *opt, u_int opt_len, u_char flags _U_)
+{
+ const struct mp_tcprst *mpr = (const struct mp_tcprst *)opt;
+
+ if (opt_len != 4)
+ return 0;
+
+ ND_PRINT(" flags [%s]", bittok2str_nosep(mp_tcprst_flags, "none",
+ GET_U_1(mpr->sub_b)));
+
+ ND_PRINT(" reason %s", tok2str(mp_tcprst_reasons, "unknown (0x%02x)",
+ GET_U_1(mpr->reason)));
+ return 1;
+}
+
 static const struct {
  const char *name;
  int (*print)(netdissect_options *, const u_char *, u_int, u_char);
@@ -466,6 +510,7 @@ static const struct {
  { "prio", mp_prio_print },
  { "fail", mp_fail_print },
  { "fast-close", mp_fast_close_print },
+ { "tcprst", mp_tcprst_print },
  { "unknown", dummy_print },
 };
 
@@ -482,7 +527,7 @@ mptcp_print(netdissect_options *ndo,
 
  opt = (const struct mptcp_option *) cp;
  subtype = MPTCP_OPT_SUBTYPE(GET_U_1(opt->sub_etc));
- subtype = ND_MIN(subtype, MPTCP_SUB_FCLOSE + 1);
+ subtype = ND_MIN(subtype, MPTCP_SUB_TCPRST + 1);
 
  ND_PRINT(" %u", len);
 

tests/TESTLIST

@@ -257,6 +257,7 @@ mptcp-v1	mptcp-v1.pcap	mptcp-v1.out
 mptcp-fclose	mptcp-fclose.pcap	mptcp-fclose.out
 mptcp-aa-v1	mptcp-aa-v1.pcap	mptcp-aa-v1.out
 mptcp-aa-echo	mptcp-aa-echo.pcap	mptcp-aa-echo.out
+mptcp-tcprst	mptcp-tcprst.pcap	mptcp-tcprst.out
 
 # TFO tests
 tfo	tfo-5c1fa7f9ae91.pcap	tfo.out

tests/mptcp-tcprst.out

@@ -0,0 +1,2 @@
+ 1 14:27:19.175792 IP 192.0.2.1.55739 > 192.168.76.28.8080: Flags [R.], seq 1, ack 2176696966, win 256, options [mptcp 4 tcprst flags [none] reason Unspecified error], length 0
+ 2 14:27:19.175964 IP 192.0.2.1.55739 > 192.168.76.28.8080: Flags [R.], seq 0, ack 1, win 256, options [mptcp 4 tcprst flags [T] reason MPTCP-specific error], length 0