babel: add support for babel rfc6126bis

RFC 6126 (Babel) is updated by RFC 6126bis.  This adds the
following features from 6126bis and related drafts:
      - Unicast (draft-ietf-babel-rfc6126bis-09)
      - Mandatory (draft-ietf-babel-rfc6126bis-09)
      - Unscheduled Hello (draft-ietf-babel-rfc6126bis-09)
      - HMAC, PC, Challenge Request and Reply (draft-ietf-babel-hmac-04)
      - Packet Trailer (draft-ietf-babel-rfc6126bis-09)

Bug: 15846
Change-Id: I83db9d68e3971a2adc6276882cb5c8d288eb8c98
Reviewed-on: https://code.wireshark.org/review/33564
Petri-Dish: Alexis La Goutte <alexis.lagoutte@gmail.com>
Tested-by: Petri Dish Buildbot
Reviewed-by: Anders Broman <a.broman58@gmail.com>

1 files changed, 242 insertions, 55 deletions

diff --git a/epan/dissectors/packet-babel.c b/epan/dissectors/packet-babel.c
index 790dc06ddc..6259a50a65 100644
--- a/epan/dissectors/packet-babel.c
+++ b/epan/dissectors/packet-babel.c
@@ -39,8 +39,17 @@ static int hf_babel_message_plen = -1;
 static int hf_babel_message_omitted = -1;
 static int hf_babel_message_metric = -1;
 static int hf_babel_message_hopcount = -1;
+static int hf_babel_message_index = -1;
+static int hf_babel_subtlv = -1;
+static int hf_babel_subtlv_type = -1;
+static int hf_babel_subtlv_diversity = -1;
 
 static gint ett_subtree = -1;
+static gint ett_packet_trailer = -1;
+static gint ett_unicast = -1;
+static gint ett_subtlv = -1;
+static gint ett_timestamp = -1;
+static gint ett_mandatory = -1;
 
 #define UDP_PORT_RANGE_BABEL "6696"
 
@@ -56,32 +65,57 @@ static gint ett_subtree = -1;
 #define MESSAGE_REQUEST     9
 #define MESSAGE_MH_REQUEST 10
 #define MESSAGE_TS_PC      11
-#define MESSAGE_HMAC       12
+#define MESSAGE_HMAC_OLD   12
 #define MESSAGE_SRC_UPDATE 13
 #define MESSAGE_SRC_REQUEST 14
-#define MESSAGE_SRC_SEQNO  15
+#define MESSAGE_SRC_SEQNO   15
+#define MESSAGE_HMAC    16
+#define MESSAGE_PC      17
+#define MESSAGE_CHALLENGE_REQUEST 18
+#define MESSAGE_CHALLENGE_REPLY 19
+
+/** sub-TLVs */
+#define MESSAGE_SUB_PAD1 0
+#define MESSAGE_SUB_PADN 1
+#define MESSAGE_SUB_DIVERSITY 2
+#define MESSAGE_SUB_TIMESTAMP 3
+
+/** mask for bits */
+#define UNICAST_FLAG 0x80
+#define MANDATORY_FLAG 128
 
 /** message string values listed in rfc7557 */
 static const value_string messages[] = {
-    { MESSAGE_PAD1,       "pad1"},
-    { MESSAGE_PADN,       "padn"},
-    { MESSAGE_ACK_REQ,    "ack-req"},
-    { MESSAGE_ACK,        "ack"},
-    { MESSAGE_HELLO,      "hello"},
-    { MESSAGE_IHU,        "ihu"},
-    { MESSAGE_ROUTER_ID,  "router-id"},
-    { MESSAGE_NH,         "nh"},
-    { MESSAGE_UPDATE,     "update"},
-    { MESSAGE_REQUEST,    "request"},
-    { MESSAGE_MH_REQUEST, "mh-request"},
-    { MESSAGE_TS_PC,      "ts/pc"},
-    { MESSAGE_HMAC,       "hmac" },
-    { MESSAGE_SRC_UPDATE, "source-specific-update"},
-    { MESSAGE_SRC_REQUEST,"source-specific-req"},
-    { MESSAGE_SRC_SEQNO,  "source-specific-seqno"},
+    { MESSAGE_PAD1,         "pad1"},
+    { MESSAGE_PADN,         "padn"},
+    { MESSAGE_ACK_REQ,      "ack-req"},
+    { MESSAGE_ACK,          "ack"},
+    { MESSAGE_HELLO,        "hello"},
+    { MESSAGE_IHU,          "ihu"},
+    { MESSAGE_ROUTER_ID,    "router-id"},
+    { MESSAGE_NH,           "nh"},
+    { MESSAGE_UPDATE,       "update"},
+    { MESSAGE_REQUEST,      "request"},
+    { MESSAGE_MH_REQUEST,   "mh-request"},
+    { MESSAGE_TS_PC,        "ts/pc (obsolete)"},
+    { MESSAGE_HMAC_OLD,     "hmac" },
+    { MESSAGE_SRC_UPDATE,   "source-specific-update"},
+    { MESSAGE_SRC_REQUEST,  "source-specific-req"},
+    { MESSAGE_SRC_SEQNO,    "source-specific-seqno"},
+    { MESSAGE_HMAC,         "hmac"},
+    { MESSAGE_PC,           "pc"},
+    { MESSAGE_CHALLENGE_REQUEST,  "challenge-request"},
+    { MESSAGE_CHALLENGE_REPLY,    "challenge-reply"},
     { 0, NULL}
 };
 
+static const value_string subtlvs[] = {
+    { MESSAGE_SUB_PAD1,       "sub-pad1"},
+    { MESSAGE_SUB_PADN,       "sub-padn"},
+    { MESSAGE_SUB_DIVERSITY,  "diversity"},
+    { MESSAGE_SUB_TIMESTAMP,  "timestamp"},
+    { 0, NULL}
+};
 
 static const value_string aes[] = {
     { 0, "Wildcard" },
@@ -138,6 +172,7 @@ network_prefix(int ae, int plen, unsigned int omitted,
 {
     guint      pb;
     unsigned char prefix[16];
+    int consumed = 0;
 
     if (plen >= 0)
         pb = (plen + 7) / 8;
@@ -161,8 +196,10 @@ network_prefix(int ae, int plen, unsigned int omitted,
             if (dp == NULL) return -1;
             memcpy(prefix, dp, 12 + omitted);
         }
-        if (pb > omitted)
+        if (pb > omitted) {
             tvb_memcpy(tvb, prefix + 12 + omitted, offset, pb - omitted);
+            consumed = pb - omitted;
+        }
         break;
     case 2:
         if (omitted > 16 || (pb > omitted && len < pb - omitted))
@@ -171,22 +208,26 @@ network_prefix(int ae, int plen, unsigned int omitted,
             if (dp == NULL) return -1;
             memcpy(prefix, dp, omitted);
         }
-        if (pb > omitted)
+        if (pb > omitted) {
             tvb_memcpy(tvb, prefix + omitted, offset, pb - omitted);
+            consumed = pb - omitted;
+        }
         break;
     case 3:
         if (pb > 8 && len < pb - 8) return -1;
         prefix[0] = 0xfe;
         prefix[1] = 0x80;
-        if (pb > 8)
+        if (pb > 8) {
             tvb_memcpy(tvb, prefix + 8, offset, pb - 8);
+            consumed = pb - 8;
+        }
         break;
     default:
         return -1;
     }
 
     memcpy(p_r, prefix, 16);
-    return 1;
+    return consumed;
 }
 
 static int
@@ -196,45 +237,109 @@ network_address(int ae, tvbuff_t *tvb, int offset, unsigned int len,
     return network_prefix(ae, -1, 0, tvb, offset, NULL, len, a_r);
 }
 
-static int
-dissect_babel(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_)
+static const char *
+format_timestamp(const guint32 i)
 {
-    proto_item    *ti;
-    unsigned char  v4_prefix[16] = {0}, v6_prefix[16] = {0};
-    int            i;
-    proto_tree    *babel_tree = NULL;
-    guint8         version;
-    guint16        bodylen;
-
-    if (tvb_captured_length(tvb) < 4)
-        return 0;
+    static char buf[sizeof("0000.000000s")];
+    g_snprintf(buf, sizeof(buf), "%u.%06us", i / 1000000, i % 1000000);
+    return buf;
+}
 
-    if (tvb_get_guint8(tvb, 0) != 42)
-        return 0;
-    version = tvb_get_guint8(tvb, 1);
+static int
+dissect_babel_subtlvs(tvbuff_t * tvb, guint8 type, guint8 beg, guint8 end,
+                      proto_tree *message_tree)
+{
+    proto_tree *channel_tree = NULL;
+    proto_item *sub_item;
+    guint8      subtype, sublen;
+    int i = 0;
+
+    while(beg < end) {
+        proto_tree *subtlv_tree = NULL;
+        subtype = tvb_get_guint8(tvb, beg);
+        sublen = tvb_get_guint8(tvb, beg+1);
+
+        sub_item =
+          proto_tree_add_uint_format(message_tree, hf_babel_subtlv,
+                                     tvb, beg, sublen, subtype,
+                                     "Sub TLV %s (%u)",
+                                     val_to_str_const(subtype, subtlvs, "unknown"),
+                                     subtype);
+
+        if (message_tree) {
+            subtlv_tree = proto_item_add_subtree(sub_item, ett_subtlv);
+            proto_tree_add_item(subtlv_tree, hf_babel_subtlv_type,
+                                tvb, beg+2, 1, ENC_BIG_ENDIAN);
+        }
 
-    col_set_str(pinfo->cinfo, COL_PROTOCOL, "Babel");
-    col_set_str(pinfo->cinfo, COL_INFO, "Babel");
+        if(subtype == MESSAGE_SUB_PAD1){
+            beg += sublen;
+            continue;
+        }
+        if ((MANDATORY_FLAG & subtype) != 0) {
+            proto_tree_add_subtree_format(subtlv_tree, tvb, beg+2, sublen,
+                                          ett_mandatory, NULL, "Mandatory");
+        }
 
-    if (version != 2) {
-        col_add_fstr(pinfo->cinfo, COL_INFO, "Version %u", version);
-        return 2;
+        switch(subtype) {
+            case MESSAGE_SUB_PADN:
+                break;
+            case MESSAGE_SUB_DIVERSITY: {
+                i = 0;
+                channel_tree = proto_tree_add_subtree_format(subtlv_tree, tvb,
+                                                             beg+2, 0, ett_subtlv,
+                                                             NULL, "Channel");
+                while(i < sublen) {
+                    proto_tree_add_item(channel_tree, hf_babel_subtlv_diversity,
+                                        tvb, beg+2+i, 1, ENC_BIG_ENDIAN);
+                    i++;
+                }
+            }
+                break;
+            case MESSAGE_SUB_TIMESTAMP:  {
+                if (type == MESSAGE_HELLO) {
+                    guint32 t1 = tvb_get_guint32(tvb, beg+2, ENC_BIG_ENDIAN);
+                    proto_tree_add_subtree_format(subtlv_tree, tvb, beg+2,
+                                                  sublen, ett_timestamp, NULL,
+                                                  "Timestamp : %s",
+                                                  format_timestamp(t1));
+                } else if (type == MESSAGE_IHU) {
+                    guint32 t1 = tvb_get_guint32(tvb, beg+2, ENC_BIG_ENDIAN);
+                    guint32 t2 = tvb_get_guint32(tvb, beg+6, ENC_BIG_ENDIAN);
+                    proto_tree_add_subtree_format(subtlv_tree, tvb, beg+2,
+                                                  sublen, ett_timestamp, NULL,
+                                                  "Timestamp origin : %s",
+                                                  format_timestamp(t1));
+                    proto_tree_add_subtree_format(subtlv_tree, tvb, beg+6,
+                                                  sublen, ett_timestamp, NULL,
+                                                  "Timestamp receive: %s",
+                                                  format_timestamp(t2));
+                } else {
+                    proto_tree_add_subtree_format(subtlv_tree, tvb, beg+2, sublen,
+                                                  ett_timestamp, NULL, "Bogus");
+                }
+            }
+              break;
+        }
+        beg += (sublen+2);
     }
+    return end-beg;
+}
 
-    if (tree) {
-        ti = proto_tree_add_item(tree, proto_babel, tvb, 0, -1, ENC_NA);
-        babel_tree = proto_item_add_subtree(ti, ett_babel);
 
-        proto_tree_add_item(babel_tree, hf_babel_magic, tvb, 0, 1, ENC_BIG_ENDIAN);
-        proto_tree_add_item(babel_tree, hf_babel_version, tvb, 1, 1, ENC_BIG_ENDIAN);
-        proto_tree_add_item(babel_tree, hf_babel_bodylen,
-                            tvb, 2, 2, ENC_BIG_ENDIAN);
-    }
+/* The following function is used to read the packet body and
+ the packet trailer */
+static int
+dissect_babel_body(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
+                   int offset, guint16 bodylen)
+{
+    proto_item *ti = NULL;
+    unsigned char  v4_prefix[16] = {0}, v6_prefix[16] = {0};
+    int            i;
 
-    bodylen = tvb_get_ntohs(tvb, 2);
 
-    i = 0;
-    while (i < bodylen) {
+    i = offset;
+    while (i-offset < bodylen) {
         guint8      type, len    = 0, total_length;
         proto_tree *message_tree = NULL;
         int         message      = 4 + i;
@@ -250,7 +355,7 @@ dissect_babel(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U
         col_append_fstr(pinfo->cinfo, COL_INFO, " %s",
                         val_to_str_const(type, messages, "unknown"));
 
-        ti = proto_tree_add_uint_format(babel_tree, hf_babel_message,
+        ti = proto_tree_add_uint_format(tree, hf_babel_message,
                                         tvb, message, total_length, type,
                                         "Message %s (%u)",
                                         val_to_str_const(type, messages, "unknown"),
@@ -270,7 +375,6 @@ dissect_babel(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U
         if (tree) {
             proto_tree_add_item(message_tree, hf_babel_message_length,
                                 tvb, message + 1, 1, ENC_BIG_ENDIAN);
-
             if (type == MESSAGE_PADN) {
             } else if (type == MESSAGE_ACK_REQ) {
                 proto_tree_add_item(message_tree, hf_babel_message_nonce,
@@ -281,10 +385,19 @@ dissect_babel(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U
                 proto_tree_add_item(message_tree, hf_babel_message_nonce,
                                     tvb, message + 2, 2, ENC_BIG_ENDIAN);
             } else if (type == MESSAGE_HELLO) {
+                guint8 unicast = tvb_get_guint8(tvb, 2);
+                proto_tree_add_subtree_format(message_tree,
+                                         tvb, message + 2, 2,
+                                         ett_unicast, NULL,
+                                         "Unicast : %u",
+                                         unicast);
                 proto_tree_add_item(message_tree, hf_babel_message_seqno,
                                     tvb, message + 4, 2, ENC_BIG_ENDIAN);
                 proto_tree_add_item(message_tree, hf_babel_message_interval,
                                     tvb, message + 6, 2, ENC_BIG_ENDIAN);
+                if(len > 6)
+                    dissect_babel_subtlvs(tvb, type, message + 8,
+                                          message + 2 + len, message_tree);
             } else if (type == MESSAGE_IHU) {
                 proto_tree    *subtree;
                 unsigned char  addr_str[16];
@@ -304,6 +417,9 @@ dissect_babel(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U
                                     tvb, message + 2, 1, ENC_BIG_ENDIAN);
                 proto_tree_add_item(subtree, hf_babel_message_prefix,
                                     tvb, message + 4, len - 2, ENC_NA);
+                if (rc < len - 6)
+                    dissect_babel_subtlvs(tvb, type, message + 8 + rc,
+                                          message + 2 + len, message_tree);
             } else if (type == MESSAGE_ROUTER_ID) {
                 proto_tree_add_item(message_tree, hf_babel_message_routerid,
                                     tvb, message + 4, 8, ENC_NA);
@@ -323,7 +439,6 @@ dissect_babel(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U
                 proto_tree_add_item(subtree, hf_babel_message_prefix,
                                     tvb, message + 4, len - 2, ENC_NA);
             } else if (type == MESSAGE_UPDATE) {
-
                 proto_tree    *subtree;
                 unsigned char  p[16];
                 guint8         ae    = tvb_get_guint8(tvb, message + 2);
@@ -364,6 +479,9 @@ dissect_babel(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U
                                     tvb, message + 5, 1, ENC_BIG_ENDIAN);
                 proto_tree_add_item(subtree, hf_babel_message_prefix,
                                     tvb, message + 12, len - 10, ENC_NA);
+                if (((guint8)rc) < len - 10)
+                    dissect_babel_subtlvs(tvb, type, message + 12 + rc,
+                                          message + 2 + len, message_tree);
             } else if (type == MESSAGE_REQUEST) {
                 proto_tree    *subtree;
                 unsigned char  p[16];
@@ -410,13 +528,61 @@ dissect_babel(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U
                                     tvb, message + 3, 1, ENC_BIG_ENDIAN);
                 proto_tree_add_item(subtree, hf_babel_message_prefix,
                                     tvb, message + 16, len - 14, ENC_NA);
+            } else if (type == MESSAGE_PC){
+                proto_tree_add_item(message_tree, hf_babel_message_index,
+                                    tvb, message + 2, 4, ENC_NA);
             }
         }
         i += len + 2;
     }
+    guint8 packet_len = tvb_reported_length(tvb) - bodylen - 4;
+    if ((offset == 0) && (packet_len != 0)) {
+        proto_tree * subtree;
+        subtree = proto_tree_add_subtree_format(tree, tvb, 4+bodylen, packet_len,
+                                                ett_packet_trailer, NULL,
+                                                "Packet Trailer (%u)", packet_len);
+        dissect_babel_body(tvb, pinfo, subtree, bodylen, packet_len);
+    }
     return i;
 }
 
+static int
+dissect_babel(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_)
+{
+    proto_item    *ti;
+    proto_tree    *babel_tree = NULL;
+    guint8         version;
+    guint16        bodylen;
+
+    if (tvb_captured_length(tvb) < 4)
+        return 0;
+
+    if (tvb_get_guint8(tvb, 0) != 42)
+        return 0;
+    version = tvb_get_guint8(tvb, 1);
+
+    col_set_str(pinfo->cinfo, COL_PROTOCOL, "Babel");
+    col_set_str(pinfo->cinfo, COL_INFO, "Babel");
+
+    if (version != 2) {
+        col_add_fstr(pinfo->cinfo, COL_INFO, "Version %u", version);
+        return 2;
+    }
+
+    if (tree) {
+        ti = proto_tree_add_item(tree, proto_babel, tvb, 0, -1, ENC_NA);
+        babel_tree = proto_item_add_subtree(ti, ett_babel);
+
+        proto_tree_add_item(babel_tree, hf_babel_magic, tvb, 0, 1, ENC_BIG_ENDIAN);
+        proto_tree_add_item(babel_tree, hf_babel_version, tvb, 1, 1, ENC_BIG_ENDIAN);
+        proto_tree_add_item(babel_tree, hf_babel_bodylen,
+                            tvb, 2, 2, ENC_BIG_ENDIAN);
+    }
+    bodylen = tvb_get_ntohs(tvb, 2);
+    return dissect_babel_body(tvb, pinfo, babel_tree, 0, bodylen);
+
+}
+
 void
 proto_register_babel(void)
 {
@@ -493,12 +659,33 @@ proto_register_babel(void)
           { "Hop Count", "babel.message.hopcount", FT_UINT8, BASE_DEC,
             NULL, 0, NULL, HFILL }
         },
+        { &hf_babel_message_index,
+          { "Index", "babel.message.index", FT_UINT32, BASE_DEC,
+          NULL, 0, NULL, HFILL }
+        },
+        { &hf_babel_subtlv,
+          { "Sub-TLV", "babel.subtlv", FT_UINT8, BASE_DEC,
+          NULL, 0, "Babel Sub-TLV", HFILL }
+        },
+        { &hf_babel_subtlv_type,
+          { "Sub-TLV Type", "babel.subtlv.type", FT_UINT8, BASE_DEC,
+          VALS(subtlvs), 0, NULL, HFILL }
+        },
+        { &hf_babel_subtlv_diversity,
+          { "Channel", "babel.subtlv.diversity.channel", FT_UINT8, BASE_DEC,
+          NULL, 0, NULL, HFILL  }
+        }
     };
 
     static gint *ett[] = {
         &ett_babel,
         &ett_message,
         &ett_subtree,
+        &ett_packet_trailer,
+        &ett_unicast,
+        &ett_subtlv,
+        &ett_timestamp,
+        &ett_mandatory
     };
 
     proto_babel =