static void
dissect_mime_encap(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
proto_item* item;
guint len;
/* XXX, COL_INFO */
col_set_str(pinfo->cinfo, COL_PROTOCOL, "MIME_FILE");
item = proto_tree_add_item(tree, proto_mime_encap, tvb, 0, -1, ENC_NA);
/* frames with nsec >= 1000000000 means errors :) */
if (pinfo->fd->abs_ts.nsecs >= 1000000000) {
proto_item_append_text(item, " (Error)");
/* return; */ /* dissect what we have */
}
len = tvb_length(tvb);
if (!pinfo->fd->flags.visited) {
if (len) {
tvbuff_t *cloned_tvb = tvb_clone(tvb);
if (!file_tvbs) {
file_tvbs = cloned_tvb;
whole_tvb = tvb_new_composite();
} else
tvb_add_to_chain(file_tvbs, cloned_tvb);
tvb_composite_append(whole_tvb, cloned_tvb);
} else
tvb_composite_finalize(whole_tvb);
}
/* End of file? */
if (!len && whole_tvb) {
/*
* Here we're doing some trick.
*
* We don't want to call dissectors with composite tvb, cause dissectors can create subsets or real data child
* on it, which would append to whole_tvb chain and would be freed only in mime_encap_init.
*
* So we create some tvb which pass all calls to whole_tvb, but chain with tvb (which is freed in dissection cleanup)
*/
tvbuff_t *tmp_tvb = tvb_new_chain(tvb, whole_tvb);
proto_item_append_text(item, " (Final)");
add_new_data_source(pinfo, tmp_tvb, "Whole file");
if (!dissector_try_heuristic(heur_subdissector_list, tmp_tvb, pinfo, tree, NULL)) {
proto_item_append_text(item, " (Unhandled)");
call_dissector(data_handle, tmp_tvb, pinfo, tree);
}
}
}
/* Decode and display the PDU Burst */
static void pdu_burst_decoder(proto_tree *tree, tvbuff_t *tvb, gint offset, gint length, packet_info *pinfo, gint burst_number, gint frag_type, gint frag_number)
{
fragment_head *pdu_frag;
tvbuff_t *pdu_tvb = NULL;
/* update the info column */
switch (frag_type)
{
case TLV_FIRST_FRAG:
col_append_sep_fstr(pinfo->cinfo, COL_INFO, NULL, "First TLV Fragment (%d)", frag_number);
break;
case TLV_LAST_FRAG:
col_append_sep_fstr(pinfo->cinfo, COL_INFO, NULL, "Last TLV Fragment (%d)", frag_number);
break;
case TLV_MIDDLE_FRAG:
col_append_sep_fstr(pinfo->cinfo, COL_INFO, NULL, "Middle TLV Fragment %d", frag_number);
break;
}
if(frag_type == TLV_NO_FRAG)
{ /* not fragmented PDU */
pdu_tvb = tvb_new_subset_length(tvb, offset, length);
}
else /* fragmented PDU */
{ /* add the fragment */
pdu_frag = fragment_add_seq(&pdu_reassembly_table, tvb, offset, pinfo, burst_number, NULL, frag_number - 1, length, ((frag_type==TLV_LAST_FRAG)?0:1), 0);
if(pdu_frag && frag_type == TLV_LAST_FRAG)
{
/* create the new tvb for defragmented frame */
pdu_tvb = tvb_new_chain(tvb, pdu_frag->tvb_data);
/* add the defragmented data to the data source list */
add_new_data_source(pinfo, pdu_tvb, "Reassembled WiMax PDU Frame");
}
else
{
pdu_tvb = NULL;
if(frag_type == TLV_LAST_FRAG)
{ /* update the info column */
col_append_sep_str(pinfo->cinfo, COL_INFO, ", ", "Incomplete PDU frame");
}
}
}
/* process the defragmented PDU burst */
if(pdu_tvb)
{
if(wimax_pdu_burst_handle)
{/* decode and display PDU Burst */
call_dissector(wimax_pdu_burst_handle, pdu_tvb, pinfo, tree);
}
else /* display PDU Burst info */
{ /* update the info column */
col_append_str(pinfo->cinfo, COL_INFO, "PDU Burst");
}
}
}
static int
dissect_gssapi_work(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
gboolean is_verifier, gssapi_encrypt_info_t* encrypt_info)
{
proto_item *volatile item;
proto_tree *volatile subtree;
volatile int return_offset = 0;
gssapi_conv_info_t *volatile gss_info;
gssapi_oid_value *oidvalue;
dissector_handle_t handle;
conversation_t *conversation;
tvbuff_t *oid_tvb;
int len, start_offset, oid_start_offset;
volatile int offset;
gint8 appclass;
gboolean pc, ind_field;
gint32 tag;
guint32 len1;
const char *oid;
fragment_head *fd_head=NULL;
gssapi_frag_info_t *fi;
tvbuff_t *volatile gss_tvb=NULL;
asn1_ctx_t asn1_ctx;
start_offset=0;
offset=0;
asn1_ctx_init(&asn1_ctx, ASN1_ENC_BER, TRUE, pinfo);
/*
* We don't know whether the data is encrypted, so say it's
* not, for now. The subdissector must set gssapi_data_encrypted
* if it is.
*/
encrypt_info->gssapi_data_encrypted = FALSE;
/*
* We need a conversation for later
*/
conversation = find_or_create_conversation(pinfo);
gss_info = (gssapi_conv_info_t *)conversation_get_proto_data(conversation, proto_gssapi);
if (!gss_info) {
gss_info = wmem_new(wmem_file_scope(), gssapi_conv_info_t);
gss_info->oid=NULL;
gss_info->do_reassembly=FALSE;
gss_info->frags=wmem_tree_new(wmem_file_scope());
conversation_add_proto_data(conversation, proto_gssapi, gss_info);
}
item = proto_tree_add_item(
tree, proto_gssapi, tvb, offset, -1, ENC_NA);
subtree = proto_item_add_subtree(item, ett_gssapi);
/*
* Catch the ReportedBoundsError exception; the stuff we've been
* handed doesn't necessarily run to the end of the packet, it's
* an item inside a packet, so if it happens to be malformed (or
* we, or a dissector we call, has a bug), so that an exception
* is thrown, we want to report the error, but return and let
* our caller dissect the rest of the packet.
*
* If it gets a BoundsError, we can stop, as there's nothing more
* in the packet after our blob to see, so we just re-throw the
* exception.
*/
TRY {
gss_tvb=tvb;
/* First of all, if it's the first time we see this packet
* then check whether we are in the middle of reassembly or not
*/
if( (!pinfo->fd->flags.visited)
&& (gss_info->do_reassembly)
&& (gssapi_reassembly) ){
fi=(gssapi_frag_info_t *)wmem_tree_lookup32(gss_info->frags, gss_info->first_frame);
if(!fi){
goto done;
}
wmem_tree_insert32(gss_info->frags, pinfo->num, fi);
fd_head=fragment_add(&gssapi_reassembly_table,
tvb, 0, pinfo, fi->first_frame, NULL,
gss_info->frag_offset,
tvb_captured_length(tvb), TRUE);
gss_info->frag_offset+=tvb_captured_length(tvb);
/* we need more fragments */
if(!fd_head){
goto done;
}
/* this blob is now fully reassembled */
gss_info->do_reassembly=FALSE;
fi->reassembled_in=pinfo->num;
gss_tvb=tvb_new_chain(tvb, fd_head->tvb_data);
add_new_data_source(pinfo, gss_tvb, "Reassembled GSSAPI");
}
/* We have seen this packet before.
* Is this blob part of reassembly or a normal blob ?
*/
if( (pinfo->fd->flags.visited)
&& (gssapi_reassembly) ){
fi=(gssapi_frag_info_t *)wmem_tree_lookup32(gss_info->frags, pinfo->num);
if(fi){
fd_head=fragment_get(&gssapi_reassembly_table,
pinfo, fi->first_frame, NULL);
if(fd_head && (fd_head->flags&FD_DEFRAGMENTED)){
if(pinfo->num==fi->reassembled_in){
proto_item *frag_tree_item;
gss_tvb=tvb_new_chain(tvb, fd_head->tvb_data);
add_new_data_source(pinfo, gss_tvb, "Reassembled GSSAPI");
show_fragment_tree(fd_head, &gssapi_frag_items, tree, pinfo, tvb, &frag_tree_item);
} else {
proto_item *it;
it=proto_tree_add_uint(tree, hf_gssapi_reassembled_in, tvb, 0, 0, fi->reassembled_in);
PROTO_ITEM_SET_GENERATED(it);
goto done;
}
}
}
}
/* Read header */
offset = get_ber_identifier(gss_tvb, offset, &appclass, &pc, &tag);
offset = get_ber_length(gss_tvb, offset, &len1, &ind_field);
if (!(appclass == BER_CLASS_APP && pc && tag == 0)) {
/* It could be NTLMSSP, with no OID. This can happen
for anything that microsoft calls 'Negotiate' or GSS-SPNEGO */
if ((tvb_captured_length_remaining(gss_tvb, start_offset)>7) && (tvb_strneql(gss_tvb, start_offset, "NTLMSSP", 7) == 0)) {
return_offset = call_dissector(ntlmssp_handle,
tvb_new_subset_remaining(gss_tvb, start_offset),
pinfo, subtree);
goto done;
}
/* Maybe it's new NTLMSSP payload */
if ((tvb_captured_length_remaining(gss_tvb, start_offset)>16) &&
((tvb_memeql(gss_tvb, start_offset, "\x01\x00\x00\x00", 4) == 0))) {
return_offset = call_dissector(ntlmssp_payload_handle,
tvb_new_subset_remaining(gss_tvb, start_offset),
pinfo, subtree);
encrypt_info->gssapi_data_encrypted = TRUE;
goto done;
}
if ((tvb_captured_length_remaining(gss_tvb, start_offset)==16) &&
((tvb_memeql(gss_tvb, start_offset, "\x01\x00\x00\x00", 4) == 0))) {
if( is_verifier ) {
return_offset = call_dissector(ntlmssp_verf_handle,
tvb_new_subset_remaining(gss_tvb, start_offset),
pinfo, subtree);
}
else if( encrypt_info->gssapi_encrypted_tvb ) {
return_offset = call_dissector_with_data(ntlmssp_data_only_handle,
tvb_new_subset_remaining(encrypt_info->gssapi_encrypted_tvb, 0),
pinfo, subtree, &encrypt_info->gssapi_decrypted_tvb);
encrypt_info->gssapi_data_encrypted = TRUE;
}
goto done;
}
/* Maybe it's new GSSKRB5 CFX Wrapping */
if ((tvb_captured_length_remaining(gss_tvb, start_offset)>2) &&
((tvb_memeql(gss_tvb, start_offset, "\04\x04", 2) == 0) ||
(tvb_memeql(gss_tvb, start_offset, "\05\x04", 2) == 0))) {
return_offset = call_dissector_with_data(spnego_krb5_wrap_handle,
tvb_new_subset_remaining(gss_tvb, start_offset),
pinfo, subtree, encrypt_info);
goto done;
}
/*
* If we do not recognise an Application class,
* then we are probably dealing with an inner context
* token or a wrap token, and we should retrieve the
* gssapi_oid_value pointer from the per-frame data or,
* if there is no per-frame data (as would be the case
* the first time we dissect this frame), from the
* conversation that exists or that we created from
* pinfo (and then make it per-frame data).
* We need to make it per-frame data as there can be
* more than one GSS-API negotiation in a conversation.
*
* Note! We "cheat". Since we only need the pointer,
* we store that as the data. (That's not really
* "cheating" - the per-frame data and per-conversation
* data code doesn't care what you supply as a data
* pointer; it just treats it as an opaque pointer, it
* doesn't dereference it or free what it points to.)
*/
oidvalue = (gssapi_oid_value *)p_get_proto_data(wmem_file_scope(), pinfo, proto_gssapi, 0);
if (!oidvalue && !pinfo->fd->flags.visited)
{
/* No handle attached to this frame, but it's the first */
/* pass, so it'd be attached to the conversation. */
oidvalue = gss_info->oid;
if (gss_info->oid)
p_add_proto_data(wmem_file_scope(), pinfo, proto_gssapi, 0, gss_info->oid);
}
if (!oidvalue)
{
proto_tree_add_expert_format(subtree, pinfo, &ei_gssapi_unknown_header, gss_tvb, start_offset, 0,
"Unknown header (class=%d, pc=%d, tag=%d)",
appclass, pc, tag);
return_offset = tvb_captured_length(gss_tvb);
goto done;
} else {
tvbuff_t *oid_tvb_local;
oid_tvb_local = tvb_new_subset_remaining(gss_tvb, start_offset);
if (is_verifier)
handle = oidvalue->wrap_handle;
else
handle = oidvalue->handle;
len = call_dissector_with_data(handle, oid_tvb_local, pinfo, subtree, encrypt_info);
if (len == 0)
return_offset = tvb_captured_length(gss_tvb);
else
return_offset = start_offset + len;
goto done; /* We are finished here */
}
}
/* Read oid */
oid_start_offset=offset;
offset=dissect_ber_object_identifier_str(FALSE, &asn1_ctx, subtree, gss_tvb, offset, hf_gssapi_oid, &oid);
oidvalue = gssapi_lookup_oid_str(oid);
/* Check if we need reassembly of this blob.
* Only try reassembly for OIDs we recognize
* and when we have the entire tvb
*
* SMB will sometimes split one large GSSAPI blob
* across multiple SMB/SessionSetup commands.
* While we should look at the uid returned in the response
* to the first SessionSetup and use that as a key
* instead for simplicity we assume there will not be several
* such authentication at once on a single tcp session
*/
if( (!pinfo->fd->flags.visited)
&& (oidvalue)
&& (tvb_captured_length(gss_tvb)==tvb_reported_length(gss_tvb))
&& (len1>(guint32)tvb_captured_length_remaining(gss_tvb, oid_start_offset))
&& (gssapi_reassembly) ){
fi=wmem_new(wmem_file_scope(), gssapi_frag_info_t);
fi->first_frame=pinfo->num;
fi->reassembled_in=0;
wmem_tree_insert32(gss_info->frags, pinfo->num, fi);
fragment_add(&gssapi_reassembly_table,
gss_tvb, 0, pinfo, pinfo->num, NULL,
0, tvb_captured_length(gss_tvb), TRUE);
fragment_set_tot_len(&gssapi_reassembly_table,
pinfo, pinfo->num, NULL, len1+oid_start_offset);
gss_info->do_reassembly=TRUE;
gss_info->first_frame=pinfo->num;
gss_info->frag_offset=tvb_captured_length(gss_tvb);
goto done;
}
/*
* Hand off to subdissector.
*/
if ((oidvalue == NULL) ||
!proto_is_protocol_enabled(oidvalue->proto)) {
/* No dissector for this oid */
proto_tree_add_item(subtree, hf_gssapi_token_object, gss_tvb, oid_start_offset, -1, ENC_NA);
return_offset = tvb_captured_length(gss_tvb);
goto done;
}
/* Save a pointer to the data for the OID for the
* GSSAPI protocol for this conversation.
*/
/*
* Now add the proto data ...
* but only if it is not already there.
*/
if(!gss_info->oid){
gss_info->oid=oidvalue;
}
if (is_verifier) {
handle = oidvalue->wrap_handle;
if (handle != NULL) {
oid_tvb = tvb_new_subset_remaining(gss_tvb, offset);
len = call_dissector_with_data(handle, oid_tvb, pinfo, subtree, encrypt_info);
if (len == 0)
return_offset = tvb_captured_length(gss_tvb);
else
return_offset = offset + len;
} else {
proto_tree_add_item(subtree, hf_gssapi_auth_verifier, gss_tvb, offset, -1, ENC_NA);
return_offset = tvb_captured_length(gss_tvb);
}
} else {
handle = oidvalue->handle;
if (handle != NULL) {
oid_tvb = tvb_new_subset_remaining(gss_tvb, offset);
len = call_dissector_with_data(handle, oid_tvb, pinfo, subtree, encrypt_info);
if (len == 0)
return_offset = tvb_captured_length(gss_tvb);
else
return_offset = offset + len;
} else {
proto_tree_add_item(subtree, hf_gssapi_auth_credentials, gss_tvb, offset, -1, ENC_NA);
return_offset = tvb_captured_length(gss_tvb);
}
}
done:
;
} CATCH_NONFATAL_ERRORS {
/*
* Somebody threw an exception that means that there
* was a problem dissecting the payload; that means
* that a dissector was found, so we don't need to
* dissect the payload as data or update the protocol
* or info columns.
*
* Just show the exception and then drive on to show
* the trailer, after noting that a dissector was found
* and restoring the protocol value that was in effect
* before we called the subdissector.
*/
show_exception(gss_tvb, pinfo, tree, EXCEPT_CODE, GET_MESSAGE);
} ENDTRY;
proto_item_set_len(item, return_offset);
return return_offset;
}
