static
void dissect_pw_padding(tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree)
{
/* do not touch columns */
if (tree)
{
gint size;
proto_item* item;
size = tvb_reported_length_remaining(tvb, 0);
item = proto_tree_add_item(tree, proto_pw_padding, tvb, 0, -1, FALSE);
pwc_item_append_text_n_items(item,size,"byte");
{
proto_tree* tree_p;
tree_p = proto_item_add_subtree(item, ett);
call_dissector(dh_data, tvb, pinfo, tree_p);
item = proto_tree_add_int(tree_p, hf_padding_len, tvb, 0, 0, size);
PROTO_ITEM_SET_HIDDEN(item); /*allow filtering*/
}
}
return;
}
static
void dissect_pw_satop(tvbuff_t * tvb_original
,packet_info * pinfo
,proto_tree * tree
,pwc_demux_type_t demux)
{
const int encaps_size = 4; /*RTP header in encapsulation is not supported yet*/
gint packet_size;
gint payload_size;
gint padding_size;
int properties;
enum {
PAY_NO_IDEA = 0
,PAY_LIKE_E1
,PAY_LIKE_T1
,PAY_LIKE_E3_T3
,PAY_LIKE_OCTET_ALIGNED_T1
} payload_properties;
packet_size = tvb_reported_length_remaining(tvb_original, 0);
/*
* FIXME
* "4" below should be replaced by something like "min_packet_size_this_dissector"
* Also call to dissect_try_cw_first_nibble() should be moved before this block
*/
if (packet_size < 4) /* 4 is smallest size which may be sensible (for PWACH dissector) */
{
proto_item *item;
item = proto_tree_add_item(tree, proto, tvb_original, 0, -1, ENC_NA);
expert_add_info_format(pinfo, item, &ei_cw_packet_size_too_small,
"PW packet size (%d) is too small to carry sensible information"
,(int)packet_size);
col_set_str(pinfo->cinfo, COL_PROTOCOL, shortname);
col_set_str(pinfo->cinfo, COL_INFO, "Malformed: PW packet is too small");
return;
}
switch (demux)
{
case PWC_DEMUX_MPLS:
if (dissect_try_cw_first_nibble(tvb_original, pinfo, tree))
{
return;
}
break;
case PWC_DEMUX_UDP:
break;
default:
DISSECTOR_ASSERT_NOT_REACHED();
return;
}
/* check how "good" is this packet */
/* also decide payload length from packet size and CW */
properties = 0;
if (0 != (tvb_get_guint8(tvb_original, 0) & 0xf0 /*bits03*/))
{
properties |= PWC_CW_BAD_BITS03;
}
if (0 != (tvb_get_guint8(tvb_original, 0) & 0x03 /*rsv*/))
{
properties |= PWC_CW_BAD_RSV;
}
if (0 != (tvb_get_guint8(tvb_original, 1) & 0xc0 /*frag*/))
{
properties |= PWC_CW_BAD_FRAG;
}
{
/* RFC4553:
* [...MAY be used to carry the length of the SAToP
* packet (defined as the size of the SAToP header + the payload
* size) if it is less than 64 bytes, and MUST be set to zero
* otherwise... ]
*
* Note that this differs from RFC4385's definition of length:
* [ If the MPLS payload is less than 64 bytes, the length field
* MUST be set to the length of the PW payload...]
*
* We will use RFC4553's definition here.
*/
int cw_len;
gint payload_size_from_packet;
cw_len = tvb_get_guint8(tvb_original, 1) & 0x3f;
payload_size_from_packet = packet_size - encaps_size;
if (cw_len != 0)
{
gint payload_size_from_cw;
payload_size_from_cw = cw_len - encaps_size;
/*
* Assumptions for error case,
* will be overwritten if no errors found:
*/
payload_size = payload_size_from_packet;
padding_size = 0;
if (payload_size_from_cw < 0)
{
properties |= PWC_CW_BAD_PAYLEN_LT_0;
}
else if (payload_size_from_cw > payload_size_from_packet)
{
properties |= PWC_CW_BAD_PAYLEN_GT_PACKET;
}
else if (payload_size_from_packet >= 64)
{
properties |= PWC_CW_BAD_LEN_MUST_BE_0;
}
else /* ok */
{
payload_size = payload_size_from_cw;
padding_size = payload_size_from_packet - payload_size_from_cw; /* >=0 */
}
}
else
{
payload_size = payload_size_from_packet;
padding_size = 0;
}
}
if (payload_size == 0)
{
/*
* As CW.L it indicates that PW payload is invalid, dissector should
* not blame packets with bad payload (including "bad" or "strange" SIZE of
* payload) when L bit is set.
*/
if (0 == (tvb_get_guint8(tvb_original, 0) & 0x08 /*L bit*/))
{
properties |= PWC_PAY_SIZE_BAD;
}
}
/* guess about payload type */
if (payload_size == 256)
{
payload_properties = PAY_LIKE_E1;
}
else if (payload_size == 192)
{
payload_properties = PAY_LIKE_T1;
}
else if (payload_size == 1024)
{
payload_properties = PAY_LIKE_E3_T3;
}
else if ((payload_size != 0) && (payload_size % 25 == 0))
{
payload_properties = PAY_LIKE_OCTET_ALIGNED_T1;
}
else
{
payload_properties = PAY_NO_IDEA; /*we do not have any ideas about payload type*/
}
/* fill up columns*/
col_set_str(pinfo->cinfo, COL_PROTOCOL, shortname);
col_clear(pinfo->cinfo, COL_INFO);
if (properties & PWC_ANYOF_CW_BAD)
{
col_set_str(pinfo->cinfo, COL_INFO, "CW:Bad, ");
}
if (properties & PWC_PAY_SIZE_BAD)
{
col_append_str(pinfo->cinfo, COL_INFO, "Payload size:0 (Bad)");
}
else
{
col_append_fstr(pinfo->cinfo, COL_INFO, "TDM octets:%d", (int)payload_size);
}
if (padding_size != 0)
{
col_append_fstr(pinfo->cinfo, COL_INFO, ", Padding:%d", (int)padding_size);
}
{
proto_item* item;
item = proto_tree_add_item(tree, proto, tvb_original, 0, -1, ENC_NA);
pwc_item_append_cw(item,tvb_get_ntohl(tvb_original, 0),TRUE);
pwc_item_append_text_n_items(item,(int)payload_size,"octet");
{
proto_tree* tree2;
tree2 = proto_item_add_subtree(item, ett);
{
tvbuff_t* tvb;
proto_item* item2;
tvb = tvb_new_subset_length(tvb_original, 0, PWC_SIZEOF_CW);
item2 = proto_tree_add_item(tree2, hf_cw, tvb, 0, -1, ENC_NA);
pwc_item_append_cw(item2, tvb_get_ntohl(tvb, 0),FALSE);
{
proto_tree* tree3;
tree3 = proto_item_add_subtree(item2, ett);
{
proto_item* item3;
if (properties & PWC_CW_BAD_BITS03) /*display only if value is wrong*/
{
item3 = proto_tree_add_item(tree3, hf_cw_bits03, tvb, 0, 1, ENC_BIG_ENDIAN);
expert_add_info(pinfo, item3, &ei_cw_bits03);
}
proto_tree_add_item(tree3, hf_cw_l , tvb, 0, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(tree3, hf_cw_r , tvb, 0, 1, ENC_BIG_ENDIAN);
item3 = proto_tree_add_item(tree3, hf_cw_rsv, tvb, 0, 1, ENC_BIG_ENDIAN);
if (properties & PWC_CW_BAD_RSV)
{
expert_add_info(pinfo, item3, &ei_cw_rsv);
}
item3 = proto_tree_add_item(tree3, hf_cw_frg, tvb, 1, 1, ENC_BIG_ENDIAN);
if (properties & PWC_CW_BAD_FRAG)
{
expert_add_info(pinfo, item3, &ei_cw_frg);
}
item3 = proto_tree_add_item(tree3, hf_cw_len, tvb, 1, 1, ENC_BIG_ENDIAN);
if (properties & PWC_CW_BAD_PAYLEN_LT_0)
{
expert_add_info_format(pinfo, item3, &ei_payload_size_invalid,
"Bad Length: too small, must be > %d",
(int)encaps_size);
}
if (properties & PWC_CW_BAD_PAYLEN_GT_PACKET)
{
expert_add_info_format(pinfo, item3, &ei_payload_size_invalid,
"Bad Length: must be <= than PSN packet size (%d)",
(int)packet_size);
}
if (properties & PWC_CW_BAD_LEN_MUST_BE_0)
{
expert_add_info_format(pinfo, item3, &ei_payload_size_invalid,
"Bad Length: must be 0 if SAToP packet size (%d) is > 64",
(int)packet_size);
}
proto_tree_add_item(tree3, hf_cw_seq, tvb, 2, 2, ENC_BIG_ENDIAN);
}
}
}
}
/* payload */
if (properties & PWC_PAY_SIZE_BAD)
{
expert_add_info_format(pinfo, item, &ei_payload_size_invalid,
"SAToP payload: none found. Size of payload must be <> 0");
}
else if (payload_size == 0)
{
expert_add_info(pinfo, item, &ei_payload_size_invalid_undecoded);
}
else
{
proto_tree* tree2;
tree2 = proto_item_add_subtree(item, ett);
{
proto_item* item2;
tvbuff_t* tvb;
tvb = tvb_new_subset_length(tvb_original, PWC_SIZEOF_CW, payload_size);
item2 = proto_tree_add_item(tree2, hf_payload, tvb, 0, -1, ENC_NA);
pwc_item_append_text_n_items(item2,(int)payload_size,"octet");
{
proto_tree* tree3;
const char* s;
switch(payload_properties)
{
case PAY_LIKE_E1:
s = " (looks like E1)";
break;
case PAY_LIKE_T1:
s = " (looks like T1)";
break;
case PAY_LIKE_E3_T3:
s = " (looks like E3/T3)";
break;
case PAY_LIKE_OCTET_ALIGNED_T1:
s = " (looks like octet-aligned T1)";
break;
case PAY_NO_IDEA:
default:
s = "";
break;
}
proto_item_append_text(item2, "%s", s);
tree3 = proto_item_add_subtree(item2, ett);
call_data_dissector(tvb, pinfo, tree3);
item2 = proto_tree_add_int(tree3, hf_payload_l, tvb, 0, 0
,(int)payload_size); /* allow filtering */
PROTO_ITEM_SET_HIDDEN(item2);
}
}
}
/* padding */
if (padding_size > 0)
{
proto_tree* tree2;
tree2 = proto_item_add_subtree(item, ett);
{
tvbuff_t* tvb;
tvb = tvb_new_subset(tvb_original, PWC_SIZEOF_CW + payload_size, padding_size, -1);
call_dissector(pw_padding_handle, tvb, pinfo, tree2);
}
}
}
return;
}
static
void dissect_pw_cesopsn( tvbuff_t * tvb_original
,packet_info * pinfo
,proto_tree * tree
,pwc_demux_type_t demux)
{
const int encaps_size = 4; /*RTP header in encapsulation is not supported yet*/
gint packet_size;
gint payload_size;
gint padding_size;
int properties;
packet_size = tvb_reported_length_remaining(tvb_original, 0);
/*
* FIXME
* "4" below should be replaced by something like "min_packet_size_this_dissector"
* Also call to dissect_try_cw_first_nibble() should be moved before this block
*/
if (packet_size < 4) /* 4 is smallest size which may be sensible (for PWACH dissector) */
{
proto_item *item;
item = proto_tree_add_item(tree, proto, tvb_original, 0, -1, ENC_NA);
expert_add_info_format(pinfo, item, &ei_packet_size_too_small,
"PW packet size (%d) is too small to carry sensible information"
,(int)packet_size);
col_set_str(pinfo->cinfo, COL_PROTOCOL, shortname);
col_set_str(pinfo->cinfo, COL_INFO, "Malformed: PW packet is too small");
return;
}
switch (demux)
{
case PWC_DEMUX_MPLS:
if (dissect_try_cw_first_nibble(tvb_original, pinfo, tree))
{
return;
}
break;
case PWC_DEMUX_UDP:
break;
default:
DISSECTOR_ASSERT_NOT_REACHED();
return;
}
/* check how "good" is this packet */
/* also decide payload length from packet size and CW */
properties = PWC_PACKET_PROPERTIES_T_INITIALIZER;
if (0 != (tvb_get_guint8(tvb_original, 0) & 0xf0 /*bits03*/))
{
properties |= PWC_CW_BAD_BITS03;
}
if (0 != (tvb_get_guint8(tvb_original, 1) & 0xc0 /*frag*/))
{
properties |= PWC_CW_BAD_FRAG;
}
{
/* RFC5086:
* [LEN (bits (10 to 15) MAY be used to carry the length of the CESoPSN
* packet (defined as the size of the CESoPSN header + the payload size)
* if it is less than 64 bytes, and MUST be set to zero otherwise.
* Note: If fixed RTP header is used in the encapsulation, it is
* considered part of the CESoPSN header.]
*
* Note that this differs from RFC4385's definition of length:
* [ If the MPLS payload is less than 64 bytes, the length field
* MUST be set to the length of the PW payload...]
*
* We will use RFC5086's definition here.
*/
int cw_len;
gint payload_size_from_packet;
cw_len = tvb_get_guint8(tvb_original, 1) & 0x3f;
payload_size_from_packet = packet_size - encaps_size;
if (cw_len != 0)
{
gint payload_size_from_cw;
payload_size_from_cw = cw_len - encaps_size;
/*
* Assumptions for error case,
* will be overwritten if no errors found:
*/
payload_size = payload_size_from_packet;
padding_size = 0;
if (payload_size_from_cw < 0)
{
properties |= PWC_CW_BAD_PAYLEN_LT_0;
}
else if (payload_size_from_cw > payload_size_from_packet)
{
properties |= PWC_CW_BAD_PAYLEN_GT_PACKET;
}
else if (payload_size_from_packet >= 64)
{
properties |= PWC_CW_BAD_LEN_MUST_BE_0;
}
else /* ok */
{
payload_size = payload_size_from_cw;
padding_size = payload_size_from_packet - payload_size_from_cw; /* >=0 */
}
}
else
{
payload_size = payload_size_from_packet;
padding_size = 0;
}
}
{
guint8 cw_lm;
cw_lm = tvb_get_guint8(tvb_original, 0) & 0x0b /*l+mod*/;
if (NULL == try_val_to_str(cw_lm, vals_cw_lm))
{
properties |= PWC_CW_SUSPECT_LM;
}
{
guint8 l_bit, m_bits;
l_bit = (cw_lm & 0x08) >> 3;
m_bits = (cw_lm & 0x03) >> 0;
if ((l_bit == 0 && m_bits == 0x0) /*CESoPSN data packet - normal situation*/
||(l_bit == 0 && m_bits == 0x2) /*CESoPSN data packet - RDI on the AC*/ )
{
if ((payload_size == 0) || ((payload_size % 8) != 0))
{
properties |= PWC_PAY_SIZE_BAD;
}
}
else if (l_bit == 1 && m_bits == 0x0) /*TDM data is invalid; payload MAY be omitted*/
{
/*allow any size of payload*/
}
else /*reserved combinations*/
{
/*allow any size of payload*/
}
}
}
/* fill up columns*/
col_set_str(pinfo->cinfo, COL_PROTOCOL, shortname);
col_clear(pinfo->cinfo, COL_INFO);
if (properties & PWC_ANYOF_CW_BAD)
{
col_set_str(pinfo->cinfo, COL_INFO, "CW:Bad, ");
}
else if (properties & PWC_ANYOF_CW_SUSPECT)
{
col_append_str(pinfo->cinfo, COL_INFO, "CW:Suspect, ");
}
if (properties & PWC_PAY_SIZE_BAD)
{
col_append_str(pinfo->cinfo, COL_INFO, "Payload size:Bad, ");
}
col_append_fstr(pinfo->cinfo, COL_INFO, "TDM octets:%d", (int)payload_size);
if (padding_size != 0)
{
col_append_fstr(pinfo->cinfo, COL_INFO, ", Padding:%d", (int)padding_size);
}
{
proto_item* item;
item = proto_tree_add_item(tree, proto, tvb_original, 0, -1, ENC_NA);
pwc_item_append_cw(item,tvb_get_ntohl(tvb_original, 0),TRUE);
pwc_item_append_text_n_items(item,(int)payload_size,"octet");
{
proto_tree* tree2;
tree2 = proto_item_add_subtree(item, ett);
{
tvbuff_t* tvb;
proto_item* item2;
tvb = tvb_new_subset(tvb_original, 0, PWC_SIZEOF_CW, PWC_SIZEOF_CW);
item2 = proto_tree_add_item(tree2, hf_cw, tvb, 0, -1, ENC_NA);
pwc_item_append_cw(item2,tvb_get_ntohl(tvb, 0),FALSE);
{
proto_tree* tree3;
tree3 = proto_item_add_subtree(item, ett);
{
proto_item* item3;
if (properties & PWC_CW_BAD_BITS03) /*display only if value is wrong*/
{
item3 = proto_tree_add_item(tree3, hf_cw_bits03, tvb, 0, 1, ENC_BIG_ENDIAN);
expert_add_info(pinfo, item3, &ei_cw_bits03);
}
item3 = proto_tree_add_item(tree3, hf_cw_lm, tvb, 0, 1, ENC_BIG_ENDIAN);
if (properties & PWC_CW_SUSPECT_LM)
{
expert_add_info(pinfo, item3, &ei_cw_lm);
}
proto_tree_add_item(tree3, hf_cw_r, tvb, 0, 1, ENC_BIG_ENDIAN);
item3 = proto_tree_add_item(tree3, hf_cw_frg, tvb, 1, 1, ENC_BIG_ENDIAN);
if (properties & PWC_CW_BAD_FRAG)
{
expert_add_info(pinfo, item3, &ei_cw_frg);
}
item3 = proto_tree_add_item(tree3, hf_cw_len, tvb, 1, 1, ENC_BIG_ENDIAN);
if (properties & PWC_CW_BAD_PAYLEN_LT_0)
{
expert_add_info_format(pinfo, item3, &ei_pref_cw_len,
"Bad Length: too small, must be > %d",
(int)encaps_size);
}
if (properties & PWC_CW_BAD_PAYLEN_GT_PACKET)
{
expert_add_info_format(pinfo, item3, &ei_pref_cw_len,
"Bad Length: must be <= than PSN packet size (%d)",
(int)packet_size);
}
if (properties & PWC_CW_BAD_LEN_MUST_BE_0)
{
expert_add_info_format(pinfo, item3, &ei_pref_cw_len,
"Bad Length: must be 0 if CESoPSN packet size (%d) is > 64",
(int)packet_size);
}
proto_tree_add_item(tree3, hf_cw_seq, tvb, 2, 2, ENC_BIG_ENDIAN);
}
}
}
}
/* payload */
if (payload_size == 0)
{
if (properties & PWC_PAY_SIZE_BAD)
{
expert_add_info_format(pinfo, item, &ei_payload_size_invalid_error,
"CESoPSN payload: none found. Size of payload must be <> 0");
}
else
{
expert_add_info_format(pinfo, item, &ei_payload_size_invalid_undecoded,
"CESoPSN payload: omitted to conserve bandwidth");
}
}
else
{
proto_tree* tree2;
tree2 = proto_item_add_subtree(item, ett);
{
proto_item* item2;
tvbuff_t* tvb;
tvb = tvb_new_subset(tvb_original, PWC_SIZEOF_CW, payload_size, payload_size);
item2 = proto_tree_add_item(tree2, hf_payload, tvb, 0, -1, ENC_NA);
pwc_item_append_text_n_items(item2,(int)payload_size,"octet");
if (properties & PWC_PAY_SIZE_BAD)
{
expert_add_info_format(pinfo, item2, &ei_payload_size_invalid_error,
"CESoPSN packet payload size must be multiple of 8");
}
tree2 = proto_item_add_subtree(item2, ett);
call_dissector(data_handle, tvb, pinfo, tree2);
item2 = proto_tree_add_int(tree2, hf_payload_l, tvb, 0, 0
,(int)payload_size); /* allow filtering */
PROTO_ITEM_SET_HIDDEN(item2);
}
}
/* padding */
if (padding_size > 0)
{
proto_tree* tree2;
tree2 = proto_item_add_subtree(item, ett);
{
tvbuff_t* tvb;
tvb = tvb_new_subset(tvb_original, PWC_SIZEOF_CW + payload_size, padding_size, -1);
call_dissector(pw_padding_handle, tvb, pinfo, tree2);
}
}
}
return;
}
