diff options
Diffstat (limited to 'epan/dissectors/packet-tplink-smarthome.c')
| -rw-r--r-- | epan/dissectors/packet-tplink-smarthome.c | 93 |
1 files changed, 65 insertions, 28 deletions
diff --git a/epan/dissectors/packet-tplink-smarthome.c b/epan/dissectors/packet-tplink-smarthome.c index e8e0a7f45d..e2f7e133b4 100644 --- a/epan/dissectors/packet-tplink-smarthome.c +++ b/epan/dissectors/packet-tplink-smarthome.c @@ -32,10 +32,12 @@ #include <config.h> #include <epan/packet.h> #include <epan/address.h> +#include <epan/conversation.h> #include <epan/wmem_scopes.h> #include "packet-tcp.h" -#define TPLINK_SMARTHOME_PORT 9999 /* TP-Link Smart Home devices use this port on both TCP and UDP */ +#define TPLINK_SMARTHOME_PORT 9999 /* Not IANA registered */ +/* TP-Link Smart Home devices use this port on both TCP and UDP */ #define FRAME_HEADER_LEN 4 /* 4 bytes of TCP frame length header info */ /* Prototypes */ @@ -44,13 +46,41 @@ void proto_reg_handoff_tplink_smarthome(void); void proto_register_tplink_smarthome(void); +static dissector_handle_t tplink_smarthome_handle; +static dissector_handle_t tplink_smarthome_message_handle; + /* Initialize the protocol and registered fields */ -static int proto_tplink_smarthome = -1; -static gint ett_tplink_smarthome = -1; /* Initialize the subtree pointers */ +static int proto_tplink_smarthome; +static gint ett_tplink_smarthome; /* Initialize the subtree pointers */ + +static int hf_tplink_smarthome_Len; +static int hf_tplink_smarthome_Msg; + +static gboolean +test_tplink_smarthome(packet_info *pinfo _U_, tvbuff_t *tvb, int offset, void *data _U_) +{ + guint8 key = 171; + guint8 c, d; + if (tvb_captured_length_remaining(tvb, offset) < 2) { + return FALSE; + } + + /* The message is always JSON, so test the first two characters. + * They must be {" or {}, as the protocol doesn't appear to + * have whitespace.). */ + c = tvb_get_guint8(tvb, offset); + d = c ^ key; + if (d != '{') { + return FALSE; + } + d = c ^ tvb_get_guint8(tvb, offset+1); + if (d != '"' && d != '}') { + return FALSE; + } -static int hf_tplink_smarthome_Len = -1; -static int hf_tplink_smarthome_Msg = -1; + return TRUE; +} static int dissect_tplink_smarthome_message(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, @@ -58,20 +88,24 @@ dissect_tplink_smarthome_message(tvbuff_t *tvb, packet_info *pinfo, proto_tree * { proto_item *ti; proto_tree *tplink_smarthome_tree; - gint8 start; + gint8 start = 0; + guint8 c, d; + guint8 key = 171; gint32 len = tvb_captured_length(tvb); - switch (pinfo->ptype) { /* look at the IP port type */ - case PT_UDP: /* UDP */ - if (len < 2) return 0; /* don't dissect unless it contains enough to hold minimum valid JSON i.e. '{}' */ - start = 0; /* and the JSON message starts immediately */ - break; - case PT_TCP: /* TCP */ - if (len < (4 + 2)) return 0; /* don't dissect unless it has the msg length plus minimal JSON */ - start = 4; /* and the JSON message starts after that */ - break; - default: - return 0; + switch (pinfo->ptype) { /* look at the IP port type */ + case PT_UDP: + start = 0; + break; + case PT_TCP: + start = 4; + break; + default: + return 0; + } + + if (!test_tplink_smarthome(pinfo, tvb, start, data)) { + return 0; } col_set_str(pinfo->cinfo, COL_PROTOCOL, "TPLINK-SMARTHOME"); /* show the protocol name of what we're dissecting */ @@ -82,10 +116,8 @@ dissect_tplink_smarthome_message(tvbuff_t *tvb, packet_info *pinfo, proto_tree * if (pinfo->ptype == PT_TCP) { proto_tree_add_item(tplink_smarthome_tree, hf_tplink_smarthome_Len, - tvb, 0, FRAME_HEADER_LEN, ENC_BIG_ENDIAN); /* decode the the 4 byte message length field pre-pended in a TCP message, */ + tvb, 0, FRAME_HEADER_LEN, ENC_BIG_ENDIAN); /* decode the 4 byte message length field pre-pended in a TCP message, */ } - guint8 c, d; - guint8 key = 171; gint i_offset = start; gint o_offset = 0; gint decode_len = len - start; @@ -127,12 +159,15 @@ get_tplink_smarthome_message_len(packet_info *pinfo _U_, tvbuff_t *tvb, int offs static int dissect_tplink_smarthome(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data) { - if (pinfo->ptype == PT_UDP) { - dissect_tplink_smarthome_message(tvb, pinfo, tree, data); - } else { - tcp_dissect_pdus(tvb, pinfo, tree, TRUE, FRAME_HEADER_LEN, - get_tplink_smarthome_message_len, dissect_tplink_smarthome_message, data); + conversation_t *conv = find_or_create_conversation(pinfo); + if (!conversation_get_proto_data(conv, proto_tplink_smarthome)) { + if (!test_tplink_smarthome(pinfo, tvb, FRAME_HEADER_LEN, data)) { + return 0; + } + conversation_add_proto_data(conv, proto_tplink_smarthome, GUINT_TO_POINTER(1)); } + tcp_dissect_pdus(tvb, pinfo, tree, TRUE, FRAME_HEADER_LEN, + get_tplink_smarthome_message_len, dissect_tplink_smarthome_message, data); return tvb_captured_length(tvb); } @@ -160,6 +195,10 @@ proto_register_tplink_smarthome(void) proto_tplink_smarthome = proto_register_protocol("TP-Link Smart Home Protocol", /* register the protocol name and description */ "TPLINK-SMARTHOME", "tplink-smarthome"); + tplink_smarthome_handle = register_dissector("tplink-smarthome", + dissect_tplink_smarthome, proto_tplink_smarthome); + tplink_smarthome_message_handle = register_dissector("tplink-smarthome-message", + dissect_tplink_smarthome_message, proto_tplink_smarthome); proto_register_field_array(proto_tplink_smarthome, hf, array_length(hf)); /* register the header fields */ proto_register_subtree_array(ett, array_length(ett)); /* and subtrees */ @@ -168,11 +207,9 @@ proto_register_tplink_smarthome(void) void proto_reg_handoff_tplink_smarthome(void) { - dissector_handle_t tplink_smarthome_handle; - tplink_smarthome_handle = create_dissector_handle(dissect_tplink_smarthome, proto_tplink_smarthome); dissector_add_uint_with_preference("tcp.port", TPLINK_SMARTHOME_PORT, tplink_smarthome_handle); - dissector_add_uint_with_preference("udp.port", TPLINK_SMARTHOME_PORT, tplink_smarthome_handle); + dissector_add_uint_with_preference("udp.port", TPLINK_SMARTHOME_PORT, tplink_smarthome_message_handle); } /* |