osmocom
/
wireshark
14
0
Fork 1
Code Issues Pull Requests Projects Releases Wiki Activity

STUN: Update some comments

This commit is contained in:
John Thacker 2022-06-25 21:50:32 -04:00
parent b5e1e63dd0
commit dda4af1fc5
1 changed files with 34 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

41
epan/dissectors/packet-stun.c
View File

@ -62,7 +62,7 @@ void proto_reg_handoff_stun(void);
/* Dissection relevant differences between STUN/TURN specification documents
*
* Aspect | MS-TURN 15.1 | RFC 3489 | RFC 5389 | RFC 8489 (*1) |
* Aspect | MS-TURN 18.0 | RFC 3489 | RFC 5389 | RFC 8489 (*1) |
* ===============================================================================================
* Message | 0b00+14-bit | 16-bit | 0b00+14-bit, type= | |
* Type | No class or method | No class or method | class+method | |
@ -84,14 +84,24 @@ void proto_reg_handoff_stun(void);
* -----------------------------------------------------------------------------------------------
* Password | Opaque | Deprecated | Deprecated | |
* -----------------------------------------------------------------------------------------------
* NONCE & | 0x0014 | 0x0015 | 0x0015 | |
* NONCE & | 0x0014 | 0x0015 (*2) | 0x0015 | |
* REALM | 0x0015 | 0x0014 | 0x0014 | |
* -----------------------------------------------------------------------------------------------
* TURN | RFC 5766/8656 or | N/A | RFC 5766/8656 | |
* Channels | Multiplexed TURN | | | |
* | Channels | | | |
* TURN | RFC 5766/8656 or | N/A | RFC 5766: | RFC 8656: |
* Channels | Multiplexed TURN | | 0x4000-0x7FFF used | 0x4000-0x4FFF used |
* | Channels (0xFF10) | | 0x8000-0xFFFF res. | 0x5000-0xFFFF res. |
* | | | Reserved MUST NOT | Reserved MUST be |
* | | | be rejected | dropped (collision)|
* -----------------------------------------------------------------------------------------------
* *1: Only where different from RFC 5389
* *2: NONCE & REALM were first defined in Internet-Drafts after RFC 3489 was
* published. Early drafts, up to draft-ietf-behave-rfc3489bis-02 and
* draft-rosenberg-midcom-turn-08, used 0x0014 for NONCE and 0x0015 for REALM.
* The attribute numbers were swapped in draft-ietf-behave-rfc3489bis-03 (when
* moved from the TURN spec to the STUN spec), the same version that added the
* fixed 32-bit magic. Since this dissector only handles packets with the magic
* (others are rejected and processed by the classicstun dissector instead),
* the swapped values are used for RFC 3489 mode here.
*/
enum {
@ -102,6 +112,12 @@ enum {
};
/* Auto-tuning. Default: NET_VER_5389; NET_VER_MS_TURN if MAGIC_COOKIE is found */
/* NET_VER_3489 is only useful for packets that conform specifically to
* draft-ietf-behave-rfc3849bis-03; i.e. that have the 32 bit magic so that they
* are not handled by classicstun instead, have the current (swapped) NONE and
* REALM attribute numbers, but do not have the attribute padding that was
* introduced in draft-ietf-behave-rfc3849bis-04.
*/
static gint stun_network_version = NET_VER_5389;
@ -833,6 +849,15 @@ dissect_stun_message(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, gboole
if (msg_type & 0xC000) {
/* two first bits not NULL => should be a channel-data message */
/* XXX: As of RFC 8656, Channel numbers outside the range 0x4000-0x4FFF
* MUST be dropped, whereas in RFC 5766 implementations MUST NOT drop
* reserved channel numbers. Rejecting such channel numbers (in particular
* the range 0x8000-0xBFFF) allows multiplexing with DTLS-SRTP on the
* same 5-tuple by preventing collisions. That would also allow us to
* set the conversation for non-heuristic STUN dissection on UDP if we
* see any STUN message, not just a TURN message type.
*/
/*
* If the packet is being dissected through heuristics, we never match
* TURN ChannelData because the heuristics are otherwise rather weak.
@ -864,7 +889,9 @@ dissect_stun_message(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, gboole
if (captured_length < STUN_HDR_LEN)
return 0;
/* Check if it is really a STUN message */
/* Check if it is really a STUN message - reject messages without the
* RFC 5389 Magic and let the classicstun dissector handle those.
*/
if ( tvb_get_ntohl(tvb, tcp_framing_offset + 4) != MESSAGE_COOKIE)
return 0;
@ -1055,7 +1082,7 @@ dissect_stun_message(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, gboole
const gchar *attribute_name_str;
/* According to [MS-TURN] section 2.2.2.8: "This attribute MUST be the
first attribute following the TURN message header in all TURN messages */
first attribute following the TURN message header in all TURN messages" */
if (stun_network_version == NET_VER_AUTO &&
offset < (STUN_HDR_LEN + msg_length) &&
tvb_get_ntohs(tvb, offset) == MAGIC_COOKIE) {