diff options
Diffstat (limited to 'packet-fr.c')
| -rw-r--r-- | packet-fr.c | 204 |
1 files changed, 158 insertions, 46 deletions
diff --git a/packet-fr.c b/packet-fr.c index 33a011ee3d..1a1ea85a7a 100644 --- a/packet-fr.c +++ b/packet-fr.c @@ -3,7 +3,7 @@ * * Copyright 2001, Paul Ionescu <paul@acorp.ro> * - * $Id: packet-fr.c,v 1.13 2001/03/29 08:05:06 guy Exp $ + * $Id: packet-fr.c,v 1.14 2001/03/30 10:51:50 guy Exp $ * * Ethereal - Network traffic analyzer * By Gerald Combs <gerald@zing.org> @@ -47,6 +47,8 @@ #include <string.h> #include <glib.h> #include "packet.h" +#include "packet-fr.h" +#include "packet-osi.h" #include "packet-llc.h" #include "packet-chdlc.h" #include "xdlc.h" @@ -101,21 +103,47 @@ static const true_false_string ea_string = { "More Follows" }; +/* + * This isn't the same as "nlpid_vals[]"; 0x08 is Q.933, not Q.931, + * and 0x09 is LMI, not Q.2931. + */ +static const value_string fr_nlpid_vals[] = { + { NLPID_NULL, "NULL" }, + { NLPID_T_70, "T.70" }, + { NLPID_X_633, "X.633" }, + { NLPID_Q_931, "Q.933" }, + { NLPID_LMI, "LMI" }, + { NLPID_Q_2119, "Q.2119" }, + { NLPID_SNAP, "SNAP" }, + { NLPID_ISO8473_CLNP, "CLNP" }, + { NLPID_ISO9542_ESIS, "ESIS" }, + { NLPID_ISO10589_ISIS, "ISIS" }, + { NLPID_ISO10747_IDRP, "IDRP" }, + { NLPID_ISO9542X25_ESIS, "ESIS (X.25)" }, + { NLPID_ISO10030, "ISO 10030" }, + { NLPID_ISO11577, "ISO 11577" }, + { NLPID_COMPRESSED, "Data compression protocol" }, + { NLPID_IP, "IP" }, + { NLPID_PPP, "PPP" }, + { 0, NULL }, +}; + dissector_table_t fr_subdissector_table; +static void dissect_fr_nlpid(tvbuff_t *tvb, int offset, packet_info *pinfo, + proto_tree *tree, proto_item *ti, + proto_tree *fr_tree, guint8 fr_ctrl); static void dissect_lapf(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree); static void dissect_fr_xid(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree); static void dissect_fr(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) { - proto_item *ti; + proto_item *ti = NULL; proto_tree *fr_tree = NULL; guint16 fr_header,fr_type,offset=2; /* default header length of FR is 2 bytes */ guint16 address; char buf[32]; - guint8 fr_nlpid,fr_ctrl; - - CHECK_DISPLAY_AS_DATA(proto_fr, tvb, pinfo, tree); + guint8 fr_ctrl; pinfo->current_proto = "Frame Relay"; if (check_col(pinfo->fd, COL_PROTOCOL)) @@ -144,7 +172,7 @@ static void dissect_fr(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) col_add_fstr(pinfo->fd, COL_INFO, "DLCI %u", address); if (tree) { - ti = proto_tree_add_protocol_format(tree, proto_fr, tvb, 0, 4, "Frame Relay"); + ti = proto_tree_add_protocol_format(tree, proto_fr, tvb, 0, 3, "Frame Relay"); fr_tree = proto_item_add_subtree(ti, ett_fr); decode_bitfield_value(buf, fr_header, FRELAY_DLCI, 16); @@ -168,48 +196,10 @@ static void dissect_fr(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) proto_tree_add_text(fr_tree, tvb, offset, 1, "Unnumbered Information"); } offset++; - fr_nlpid = tvb_get_guint8 (tvb,offset); - if (fr_nlpid == 0) { - if (tree) - proto_tree_add_text(fr_tree, tvb, offset, 1, "Padding"); - offset++; - fr_nlpid=tvb_get_guint8( tvb,offset); - } - if (tree) - proto_tree_add_uint(fr_tree, hf_fr_nlpid, tvb, offset, 1, fr_nlpid ); - offset++; SET_ADDRESS(&pinfo->dl_src, AT_DLCI, 2, (guint8*)&address); - if (fr_nlpid == NLPID_SNAP) { - dissect_snap(tvb, offset, pinfo, tree, fr_tree, fr_ctrl, - hf_fr_oui, hf_fr_snaptype, hf_fr_pid, 0); - return; - } - - /* - * XXX - we should just call "dissect_osi()" here, but - * some of the routines "dissect_osi()" calls themselves put - * the NLPID into the tree, and not everything registered with - * "fr.ietf" is also registered with "osinl". - * - * We'd need to figure out what to do with the NLPID. - * "dissect_osi()" is registered with the "llc.dsap" dissector - * table, so if it were to put the NLPID into the protocol - * tree it'd have to create its own subtree for it - not all its - * callers can do that for it (without knowing whether they're - * going to call it or not, and the LLC dissector doesn't). - * - * Currently, it hands the NLPID as part of the tvbuff to - * the sub-dissectors it calls; if none of them need to look - * at it, we could perhaps have it put the NLPID into the - * tree and *not* have the subdissectors expect it - that's - * what would have to be done for IP, for example, as IP, - * unlike CLNP, doesn't expect an NLPID as the first byte. - */ - if (!dissector_try_port(fr_subdissector_table,fr_nlpid, tvb_new_subset(tvb,offset,-1,-1), pinfo, tree)) - dissect_data(tvb_new_subset(tvb,offset,-1,-1), 0, pinfo, tree); - return; + dissect_fr_nlpid(tvb, offset, pinfo, tree, ti, fr_tree, fr_ctrl); } else { if (address == 0) { /* this must be some sort of lapf on DLCI 0 for SVC */ @@ -234,6 +224,128 @@ static void dissect_fr(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) } } + +void dissect_fr_uncompressed(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) +{ + proto_item *ti = NULL; + proto_tree *fr_tree = NULL; + + CHECK_DISPLAY_AS_DATA(proto_fr, tvb, pinfo, tree); + + pinfo->current_proto = "Frame Relay"; + if (check_col(pinfo->fd, COL_PROTOCOL)) + col_set_str(pinfo->fd, COL_PROTOCOL, "FR"); + if (check_col(pinfo->fd, COL_INFO)) + col_clear(pinfo->fd, COL_INFO); + + if (tree) { + ti = proto_tree_add_protocol_format(tree, proto_fr, tvb, 0, 4, "Frame Relay"); + fr_tree = proto_item_add_subtree(ti, ett_fr); + } + dissect_fr_nlpid(tvb, 0, pinfo, tree, ti, fr_tree, XDLC_U); +} + +static void dissect_fr_nlpid(tvbuff_t *tvb, int offset, packet_info *pinfo, + proto_tree *tree, proto_item *ti, + proto_tree *fr_tree, guint8 fr_ctrl) +{ + guint8 fr_nlpid; + tvbuff_t *next_tvb; + + fr_nlpid = tvb_get_guint8 (tvb,offset); + if (fr_nlpid == 0) { + if (tree) + proto_tree_add_text(fr_tree, tvb, offset, 1, "Padding"); + offset++; + if (ti != NULL) { + /* Include the padding in the top-level protocol tree item. */ + proto_item_set_len(ti, proto_item_get_len(ti) + 1); + } + fr_nlpid=tvb_get_guint8( tvb,offset); + } + + /* + * OSI network layer protocols consider the NLPID to be part + * of the frame, so we'll pass it as part of the payload and, + * if the protocol is one of those, add it as a hidden item here. + */ + next_tvb = tvb_new_subset(tvb,offset,-1,-1); + if (dissector_try_port(osinl_subdissector_table, fr_nlpid, next_tvb, + pinfo, tree)) { + /* + * Yes, we got a match. Add the NLPID as a hidden item, + * so you can, at least, filter on it. + */ + if (tree) + proto_tree_add_uint_hidden(fr_tree, hf_fr_nlpid, + tvb, offset, 1, fr_nlpid ); + return; + } + + /* + * All other protocols don't. + * + * XXX - not true for Q.933 and LMI, but we don't yet have a + * Q.933 dissector (it'd be similar to the Q.931 dissector, + * but I don't think it'd be identical, although it's less + * different than is the Q.2931 dissector), and the LMI + * dissector doesn't yet put the protocol discriminator + * (NLPID) into the tree. + * + * Note that an NLPID of 0x08 for Q.933 could either be a + * Q.933 signaling message or a message for a protocol + * identified by a 2-octet layer 2 protocol type and a + * 2-octet layer 3 protocol type, those protocol type + * octets having the values from octets 6, 6a, 7, and 7a + * of a Q.931 low layer compatibility information element + * (section 4.5.19 of Q.931; Q.933 says they have the values + * from a Q.933 low layer compatibility information element, + * but Q.933 low layer compatibility information elements + * don't have protocol values in them). + * + * Assuming that, as Q.933 seems to imply, that Q.933 messages + * look just like Q.931 messages except where it explicitly + * says they differ, then the octet after the NLPID would, + * in a Q.933 message, have its upper 4 bits zero (that's + * the length of the call reference value, in Q.931, and + * is limited to 15 or fewer octets). As appears to be the case, + * octet 6 of a Q.931 low layer compatibility element has the + * 0x40 bit set, so you can distinguish between a Q.933 + * message and an encapsulated packet by checking whether + * the upper 4 bits of the octet after the NLPID are zero. + * + * To handle this, we'd handle Q.933's NLPID specially, which + * we'd want to do anyway, so that we give it a tvbuff that + * includes the NLPID. + */ + if (tree) + proto_tree_add_uint(fr_tree, hf_fr_nlpid, tvb, offset, 1, fr_nlpid ); + offset++; + if (ti != NULL) { + /* Include the NLPID in the top-level protocol tree item. */ + proto_item_set_len(ti, proto_item_get_len(ti) + 1); + } + + switch (fr_nlpid) { + + case NLPID_SNAP: + if (ti != NULL) { + /* Include the SNAP header in the top-level protocol tree item. */ + proto_item_set_len(ti, proto_item_get_len(ti) + 5); + } + dissect_snap(tvb, offset, pinfo, tree, fr_tree, fr_ctrl, + hf_fr_oui, hf_fr_snaptype, hf_fr_pid, 0); + return; + + default: + next_tvb = tvb_new_subset(tvb,offset,-1,-1); + if (!dissector_try_port(fr_subdissector_table,fr_nlpid, + next_tvb, pinfo, tree)) + dissect_data(next_tvb, 0, pinfo, tree); + break; + } +} + static void dissect_lapf(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) { proto_tree_add_text(tree, tvb, 0, 0, "Frame relay lapf not yet implemented"); @@ -274,7 +386,7 @@ void proto_register_fr(void) FRELAY_EA, "Extended Address" }}, { &hf_fr_nlpid, { "NLPID", "fr.nlpid", FT_UINT8, BASE_HEX, - VALS(nlpid_vals), 0x0, "FrameRelay Encapsulated Protocol NLPID" }}, + VALS(fr_nlpid_vals), 0x0, "FrameRelay Encapsulated Protocol NLPID" }}, { &hf_fr_oui, { "Organization Code", "fr.snap.oui", FT_UINT24, BASE_HEX, VALS(oui_vals), 0x0, ""}}, |