forked from osmocom/wireshark
manolito: refactor the message parsing
Use an offset variable, increment it as we walk through the packet. Use tvb_reported_length_remaining() to see if we have more data. Change-Id: I7048316ee418ff3e79e391295a29d9b221079847 Reviewed-on: https://code.wireshark.org/review/15485 Reviewed-by: Martin Kaiser <wireshark@kaiser.cx>
This commit is contained in:
Martin Kaiser
parent
e3a53fbd18
commit
55fdbd5346
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@ -49,7 +49,7 @@ static expert_field ei_manolito_type = EI_INIT;
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static int
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dissect_manolito(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* dissector_data _U_)
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{
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unsigned int offset;
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gint offset = 0;
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proto_item *ti;
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proto_tree *manolito_tree;
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@ -57,76 +57,77 @@ dissect_manolito(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* diss
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col_set_str(pinfo->cinfo, COL_PROTOCOL, "MANOLITO");
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ti = proto_tree_add_item(tree, proto_manolito, tvb, 0, -1, ENC_NA);
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ti = proto_tree_add_item(tree, proto_manolito, tvb, offset, -1, ENC_NA);
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manolito_tree = proto_item_add_subtree(ti, ett_manolito);
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/* MANOLITO packet header (network byte order) */
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proto_tree_add_item(manolito_tree,
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hf_manolito_checksum, tvb, 0, 4, ENC_BIG_ENDIAN);
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hf_manolito_checksum, tvb, offset, 4, ENC_BIG_ENDIAN);
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offset += 4;
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proto_tree_add_item(manolito_tree,
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hf_manolito_seqno, tvb, 4, 4, ENC_BIG_ENDIAN);
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hf_manolito_seqno, tvb, offset, 4, ENC_BIG_ENDIAN);
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offset += 4;
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proto_tree_add_item(manolito_tree,
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hf_manolito_src, tvb, 8, 4, ENC_BIG_ENDIAN);
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hf_manolito_src, tvb, offset, 4, ENC_BIG_ENDIAN);
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offset += 4;
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proto_tree_add_item(manolito_tree,
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hf_manolito_dest, tvb, 12, 4, ENC_BIG_ENDIAN);
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hf_manolito_dest, tvb, offset, 4, ENC_BIG_ENDIAN);
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offset += 4;
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if (tvb_reported_length(tvb) == 19) {
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packet_type = "Ping (truncated)";
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if (tvb_reported_length_remaining(tvb, offset) == 3) {
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proto_tree_add_item(manolito_tree,
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hf_manolito_options_short, tvb, 16, 3, ENC_BIG_ENDIAN);
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} else {
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proto_tree_add_item(manolito_tree,
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hf_manolito_options, tvb, 16, 4, ENC_BIG_ENDIAN);
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hf_manolito_options_short, tvb, offset, 3, ENC_BIG_ENDIAN);
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offset += 3;
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col_set_str(pinfo->cinfo, COL_INFO, "Ping (truncated)");
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return offset;
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}
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if (tvb_reported_length(tvb) <= 20) /* no payload, just headers */
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{
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proto_tree_add_item(manolito_tree,
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hf_manolito_options, tvb, 16, 4, ENC_BIG_ENDIAN);
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offset += 4;
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if (tvb_reported_length_remaining(tvb, offset) == 0) {
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col_set_str(pinfo->cinfo, COL_INFO, "Ping");
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} else {
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offset = 20; /* fields start here */
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return offset;
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}
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/* fields format: 2-byte name, optional NULL, 1-byte lenlen, */
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/* that many bytes(len or data), for NI,CN,VL is len, more */
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/* (that many bytes) data follows; else is raw data. */
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do
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/* fields format: 2-byte name, optional NULL, 1-byte lenlen, */
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/* that many bytes(len or data), for NI,CN,VL is len, more */
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/* (that many bytes) data follows; else is raw data. */
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do
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{
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guint16 field_name; /* 16-bit field name */
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guint8 dtype; /* data-type */
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guint8 length; /* length */
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int start; /* field starting location */
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char field_name_str[3]; /* printable name */
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const char *longname; /* human-friendly field name */
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start = offset;
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/* 2-byte field name */
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field_name = tvb_get_ntohs(tvb, offset);
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offset += 2;
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/* Identify the packet based on existing fields */
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/* Maybe using the options fields is a better idea...*/
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if (field_name == 0x434b) /* CK */
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packet_type = "Search Hit";
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if (field_name == 0x4e43) /* NC */
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packet_type = "User Information";
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if (field_name == 0x464e) /* FN - if only field */
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packet_type = "Search Query";
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if (field_name == 0x4944) /* ID ?? search by CK? */
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packet_type = "Search Query (by hash)";
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if (field_name == 0x5054) /* PT */
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packet_type = "Download Request";
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if (field_name == 0x4d45) /* ME */
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packet_type = "Chat";
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/* Find the long name of the field */
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switch(field_name)
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{
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guint16 field_name; /* 16-bit field name */
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guint8 dtype; /* data-type */
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guint8 length; /* length */
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int start; /* field starting location */
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char field_name_str[3]; /* printable name */
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const char *longname; /* human-friendly field name */
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start = offset;
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/* 2-byte field name */
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field_name = tvb_get_ntohs(tvb, offset);
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offset += 2;
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/* Identify the packet based on existing fields */
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/* Maybe using the options fields is a better idea...*/
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if (field_name == 0x434b) /* CK */
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packet_type = "Search Hit";
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if (field_name == 0x4e43) /* NC */
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packet_type = "User Information";
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if (field_name == 0x464e) /* FN - if only field */
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packet_type = "Search Query";
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if (field_name == 0x4944) /* ID ?? search by CK? */
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packet_type = "Search Query (by hash)";
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if (field_name == 0x5054) /* PT */
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packet_type = "Download Request";
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if (field_name == 0x4d45) /* ME */
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packet_type = "Chat";
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if (tvb_reported_length(tvb) == 20) /* no fields */
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packet_type = "Ping";
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/* Find the long name of the field */
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switch(field_name)
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{
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case 0x5346: longname = "Shared Files"; break; /* SF */
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case 0x534b: longname = "Shared Kilobytes"; break; /* SK */
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case 0x4e49: longname = "Network ID"; break; /* NI */
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@ -148,37 +149,37 @@ dissect_manolito(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* diss
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case 0x4944: longname = "Identification"; break; /* ID */
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case 0x4144: longname = "???"; break; /* AD */
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default: longname = "unknown"; break;
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}
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}
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/* 1-byte data type */
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/* 1-byte data type */
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#define MANOLITO_STRING 1
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#define MANOLITO_INTEGER 0
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dtype = tvb_get_guint8(tvb, offset);
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offset++;
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length = tvb_get_guint8(tvb, offset);
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offset++;
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dtype = tvb_get_guint8(tvb, offset);
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offset++;
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length = tvb_get_guint8(tvb, offset);
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offset++;
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/* convert the 16-bit integer field name to a string */
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/* XXX: changed this to use g_htons */
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field_name_str[0] = g_htons(field_name) & 0x00ff;
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field_name_str[1] = (g_htons(field_name) & 0xff00) >> 8;
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field_name_str[2] = 0;
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/* convert the 16-bit integer field name to a string */
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/* XXX: changed this to use g_htons */
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field_name_str[0] = g_htons(field_name) & 0x00ff;
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field_name_str[1] = (g_htons(field_name) & 0xff00) >> 8;
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field_name_str[2] = 0;
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if (dtype == MANOLITO_STRING)
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{
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guint8 *str;
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if (dtype == MANOLITO_STRING)
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{
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guint8 *str;
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str = tvb_get_string_enc(wmem_packet_scope(), tvb, offset, length, ENC_ASCII);
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proto_tree_add_string_format(manolito_tree, hf_manolito_string, tvb, start,
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str = tvb_get_string_enc(wmem_packet_scope(), tvb, offset, length, ENC_ASCII);
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proto_tree_add_string_format(manolito_tree, hf_manolito_string, tvb, start,
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4+length, str, "%s (%s): %s", (char*)field_name_str, longname, str);
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offset += length;
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} else if (dtype == MANOLITO_INTEGER) {
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gboolean len_ok = TRUE;
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guint64 n = 0;
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offset += length;
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} else if (dtype == MANOLITO_INTEGER) {
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gboolean len_ok = TRUE;
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guint64 n = 0;
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/* integers can be up to 5 bytes */
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switch(length)
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{
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/* integers can be up to 5 bytes */
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switch(length)
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{
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case 5:
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n = tvb_get_ntoh40(tvb, offset);
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break;
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@ -197,25 +198,23 @@ dissect_manolito(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* diss
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default:
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len_ok = FALSE;
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}
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if (len_ok) {
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ti = proto_tree_add_uint64_format(manolito_tree, hf_manolito_integer, tvb, start,
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4+length, n, "%s (%s): %" G_GINT64_MODIFIER "u",
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(char*)field_name_str, longname, n);
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}
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else {
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/* XXX - expert info */
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}
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offset += length;
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} else {
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proto_tree_add_expert_format(manolito_tree, pinfo, &ei_manolito_type,
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tvb, start, offset - start, "Unknown type %d", dtype);
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}
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} while(offset < tvb_reported_length(tvb));
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if (len_ok) {
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ti = proto_tree_add_uint64_format(manolito_tree, hf_manolito_integer, tvb, start,
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4+length, n, "%s (%s): %" G_GINT64_MODIFIER "u",
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(char*)field_name_str, longname, n);
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}
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else {
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/* XXX - expert info */
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}
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offset += length;
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} else {
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proto_tree_add_expert_format(manolito_tree, pinfo, &ei_manolito_type,
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tvb, start, offset - start, "Unknown type %d", dtype);
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}
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}
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} while(tvb_reported_length_remaining(tvb, offset));
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if (packet_type)
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{
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