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socketcan: work around libpcap bug, add CAN XL support. 

Change the "fd" gboolean in can_info_t to a guint, and give it a value
of 2 for CAN XL.  That preserves source and binary compatiility, at
least in the case where a plugin would never be handed a CAN XL frame.
Update code to treat it as such, to make it clearer what that code is
doing.

Add CAN XL support to the SocketCAN dissector - and to the
LINKTYPE_LINUX_SLL detector.  Note that the fields in the
LINKTYPE_CAN_SOCKETCAN header for CAN XL frames are *little-endian*, as
most if not all existing captures were probably done on little-endian
machines - libpcap does that so that LINKTYPE_CAN_SOCKETCAN doesn't
become one of those annoying link-layer types with *host-endian* (as in
"the byte order of the host that last processed this file") fields
(which require special processing in pcap/pcapng file readers *and* in
rpcap clients).

If the CANFD_FDF flag isn't set, treat the frame as CAN FD if it's
exactly 72 bytes long; this works around a libpcap 1.10.{2,3,4} bug
(which should be fixed in the next libpcap release) that inadvertantly
cleared that flag for CAN FD frames.
This commit is contained in:
Guy Harris 2024-02-09 10:58:06 -08:00
parent 127548227e
commit 6f0c9d4f0b
7 changed files with 325 additions and 136 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
epan/dissectors/packet-asam-cmp.c
View File

@ -1218,7 +1218,7 @@ dissect_asam_cmp_data_msg(tvbuff_t *tvb, packet_info *pinfo, proto_tree *root_tr
can_id = can_id | CAN_ERR_FLAG;
}
struct can_info can_info = { .id = can_id, .len = msg_payload_type_length, .fd = false, .bus_id = ht_interface_config_to_bus_id(interface_id) };
struct can_info can_info = { .id = can_id, .len = msg_payload_type_length, .fd = CAN_TYPE_CAN_CLASSIC, .bus_id = ht_interface_config_to_bus_id(interface_id) };
if (!socketcan_call_subdissectors(sub_tvb, pinfo, tree, &can_info, heuristic_first)) {
call_data_dissector(sub_tvb, pinfo, tree);
}
@ -1326,7 +1326,7 @@ dissect_asam_cmp_data_msg(tvbuff_t *tvb, packet_info *pinfo, proto_tree *root_tr
can_id = can_id | CAN_ERR_FLAG;
}
struct can_info can_info = { .id = can_id, .len = msg_payload_type_length, .fd = true, .bus_id = ht_interface_config_to_bus_id(interface_id) };
struct can_info can_info = { .id = can_id, .len = msg_payload_type_length, .fd = CAN_TYPE_CAN_FD, .bus_id = ht_interface_config_to_bus_id(interface_id) };
if (!socketcan_call_subdissectors(sub_tvb, pinfo, tree, &can_info, heuristic_first)) {
call_data_dissector(sub_tvb, pinfo, tree);
}

2
epan/dissectors/packet-ieee1722.c
View File

@ -2652,7 +2652,7 @@ static int dissect_1722_acf_can_common(tvbuff_t *tvb, packet_info *pinfo, proto_
}
can_info.len = (guint32)parsed.datalen;
can_info.fd = parsed.is_fd;
can_info.fd = parsed.is_fd ? CAN_TYPE_CAN_FD : CAN_TYPE_CAN_CLASSIC;
/* for practical reasons a remapping might be needed in the future */
can_info.bus_id = (guint16)parsed.bus_id;

11
epan/dissectors/packet-iso15765.c
View File

@ -938,10 +938,17 @@ dissect_iso15765_can(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void*
return 0;
}
if (can_info.fd) {
switch (can_info.fd) {
case CAN_TYPE_CAN_FD:
return dissect_iso15765(tvb, pinfo, tree, ISO15765_TYPE_CAN_FD, can_info.id, can_info.len);
} else {
case CAN_TYPE_CAN_CLASSIC:
return dissect_iso15765(tvb, pinfo, tree, ISO15765_TYPE_CAN, can_info.id, can_info.len);
default:
DISSECTOR_ASSERT_NOT_REACHED();
return tvb_captured_length(tvb);
}
}

1
epan/dissectors/packet-sll.h
View File

@ -22,6 +22,7 @@
#define LINUX_SLL_P_PPPHDLC 0x0007 /* PPP HDLC frames */
#define LINUX_SLL_P_CAN 0x000C /* Controller Area Network */
#define LINUX_SLL_P_CANFD 0x000D /* Controller Area Network flexible data rate */
#define LINUX_SLL_P_CANXL 0x000E /* Controller Area Network etended length */
#define LINUX_SLL_P_IRDA_LAP 0x0017 /* IrDA Link Access Protocol */
#define LINUX_SLL_P_ISI 0x00F5 /* Intelligent Service Interface */
#define LINUX_SLL_P_IEEE802154 0x00f6 /* 802.15.4 on monitor inteface */

405
epan/dissectors/packet-socketcan.c
View File

@ -74,6 +74,13 @@ static int hf_can_err_trx_canl;
static int hf_can_err_ctrl_specific;
static int hf_canxl_priority;
static int hf_canxl_vcid;
static int hf_canxl_secflag;
static int hf_canxl_sdu_type;
static int hf_canxl_len;
static int hf_canxl_acceptance_field;
static expert_field ei_can_err_dlc_mismatch;
static int hf_canfd_brsflag;
@ -81,9 +88,11 @@ static int hf_canfd_esiflag;
static gint ett_can;
static gint ett_can_fd;
static gint ett_can_xl;
static int proto_can;
static int proto_canfd;
static int proto_canxl;
static gboolean byte_swap = FALSE;
static gboolean heuristic_first = FALSE;
@ -103,11 +112,15 @@ static heur_dtbl_entry_t *heur_dtbl_entry;
#define CANFD_BRS 0x01 /* bit rate switch (second bitrate for payload data) */
#define CANFD_ESI 0x02 /* error state indicator of the transmitting node */
#define CANXL_LEN_OFFSET 6
#define CANXL_DATA_OFFSET 12
static dissector_table_t can_id_dissector_table = NULL;
static dissector_table_t can_extended_id_dissector_table = NULL;
static dissector_table_t subdissector_table = NULL;
static dissector_handle_t socketcan_classic_handle;
static dissector_handle_t socketcan_fd_handle;
static dissector_handle_t socketcan_xl_handle;
static dissector_handle_t socketcan_bigendian_handle;
@ -154,6 +167,19 @@ static const value_string can_err_trx_canl_vals[] = {
{ 0, NULL }
};
static const value_string canxl_sdu_type_vals[] = {
{ 0x00, "Reserved" },
{ 0x01, "Contend-based Adressing" },
{ 0x02, "Reserved for future use" },
{ 0x03, "Classical CAN/CAN FD mapped tunneling" },
{ 0x04, "IEEE 802.3 (MAC frame) tunneling" },
{ 0x05, "IEEE 802.3 (MAC frame) mapped tunneling" },
{ 0x06, "Classical CAN mapped tunneling" },
{ 0x07, "CAN FD mapped tunneling" },
{ 0xFF, "Reserved" },
{ 0, NULL }
};
/********* UATs *********/
/* Interface Config UAT */
@ -487,19 +513,24 @@ socketcan_call_subdissectors(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree
* 2) a given SocketCAN frame is known to contain a CAN FD
* packet based on information outside the SocketCAN header;
*
* 3) we don't know whether the given SocketCAN frame is a
* classic CAN packet or a CAN FD packet, and will have
* to check the CANFD_FDF bit in the "FD flags" field of
* the SocketCAN header to determine that.
* 3) a given SocketCAN frame is known to contain a CAN XL
* packet based on information outside the SocketCAN header;
*
* 4) we don't know whether the given SocketCAN frame is a
* classic CAN packet, a CAN FD packet, or a CAN XL packet,
* and will have to check the CANXL_XLF bit in the "Frame Length"
* field and the CANFD_FDF bit in the "FD flags" field of the
* SocketCAN header to determine that.
*/
typedef enum {
PACKET_TYPE_CAN,
PACKET_TYPE_CAN_FD,
PACKET_TYPE_CAN_XL,
PACKET_TYPE_UNKNOWN
} can_packet_type_t;
static int
dissect_socketcan_common(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, guint encoding, can_packet_type_t can_packet_type) {
dissect_socketcan_common(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, guint encoding, guint xl_encoding, can_packet_type_t can_packet_type) {
proto_tree *can_tree;
proto_item *ti;
guint8 frame_type;
@ -549,9 +580,15 @@ dissect_socketcan_common(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, gu
&hf_can_err_reserved,
NULL,
};
can_info.id = tvb_get_guint32(tvb, 0, encoding);
can_info.len = tvb_get_guint8(tvb, CAN_LEN_OFFSET);
static int * const canxl_prio_vcid_fields[] = {
&hf_canxl_priority,
&hf_canxl_vcid,
NULL,
};
static int * const canxl_flag_fields[] = {
&hf_canxl_secflag,
NULL,
};
/*
* If we weren't told the type of this frame, check
@ -574,145 +611,221 @@ dissect_socketcan_common(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, gu
* the code is older code that didn't support CAN FD.
*/
if (can_packet_type == PACKET_TYPE_UNKNOWN) {
guint8 frame_length;
guint8 fd_flags;
fd_flags = tvb_get_guint8(tvb, CANFD_FLAG_OFFSET);
if ((fd_flags & CANFD_FDF) && ((fd_flags & ~(CANFD_BRS | CANFD_ESI | CANFD_FDF)) == 0) &&
tvb_get_guint8(tvb, CANFD_FLAG_OFFSET + 1) == 0 &&
tvb_get_guint8(tvb, CANFD_FLAG_OFFSET + 2) == 0) {
can_packet_type = PACKET_TYPE_CAN_FD;
/*
* Check whether the frame has the CANXL_XLF flag set in what
* is in the location of the frame length field of a CAN classic
* or CAN FD frame; if so, then it's a CAN XL frame (and that
* field is the flags field of that frame).
*/
frame_length = tvb_get_guint8(tvb, CAN_LEN_OFFSET);
if (frame_length & CANXL_XLF) {
can_packet_type = PACKET_TYPE_CAN_XL;
} else {
can_packet_type = PACKET_TYPE_CAN;
/*
* This is a CAN classic or CAN FD frame.
* Check whether the flags field has the CANFD_FDF
* flag set, has no unknown flag bits set, and has
* no bits set in the two reserved fields. If so,
* it's a CAN FD frame; otherwise, it's either a
* CAN classic frame, or a frame where the CANFD_FDF
* flag is set but where that might just be because
* that field contains uninitialized junk rather
* than because it's a CAN FD frame, so we treat it
* as a CAN classic frame.
*/
fd_flags = tvb_get_guint8(tvb, CANFD_FLAG_OFFSET);
if ((fd_flags & CANFD_FDF) &&
((fd_flags & ~(CANFD_BRS | CANFD_ESI | CANFD_FDF)) == 0) &&
tvb_get_guint8(tvb, CANFD_FLAG_OFFSET + 1) == 0 &&
tvb_get_guint8(tvb, CANFD_FLAG_OFFSET + 2) == 0) {
can_packet_type = PACKET_TYPE_CAN_FD;
} else {
if (tvb_reported_length(tvb) == 72)
can_packet_type = PACKET_TYPE_CAN_FD;
else
can_packet_type = PACKET_TYPE_CAN;
}
}
}
can_info.fd = (can_packet_type == PACKET_TYPE_CAN_FD);
can_info.bus_id = get_bus_id(pinfo);
/* Error Message Frames are only encapsulated in Classic CAN frames */
if (can_packet_type == PACKET_TYPE_CAN && (can_info.id & CAN_ERR_FLAG)) {
frame_type = LINUX_CAN_ERR;
can_flags = can_err_flags;
} else if (can_info.id & CAN_EFF_FLAG) {
frame_type = LINUX_CAN_EXT;
can_info.id &= (CAN_EFF_MASK | CAN_FLAG_MASK);
can_flags = (can_packet_type == PACKET_TYPE_CAN_FD) ? can_ext_flags_fd : can_ext_flags;
} else {
frame_type = LINUX_CAN_STD;
can_info.id &= (CAN_SFF_MASK | CAN_FLAG_MASK);
can_flags = (can_packet_type == PACKET_TYPE_CAN_FD) ? can_std_flags_fd : can_std_flags;
}
if (can_packet_type == PACKET_TYPE_CAN_XL) {
can_info.fd = CAN_TYPE_CAN_XL;
col_set_str(pinfo->cinfo, COL_PROTOCOL, "CANXL");
col_clear(pinfo->cinfo, COL_INFO);
col_set_str(pinfo->cinfo, COL_PROTOCOL, (can_packet_type == PACKET_TYPE_CAN_FD) ? "CANFD" : "CAN");
col_clear(pinfo->cinfo, COL_INFO);
can_info.id = 0; /* XXX - is there an "ID" for XL frames? */
can_info.len = tvb_get_guint16(tvb, CANXL_LEN_OFFSET, xl_encoding);
guint32 effective_can_id = (can_info.id & CAN_EFF_FLAG) ? can_info.id & CAN_EFF_MASK : can_info.id & CAN_SFF_MASK;
char *id_name = (can_info.id & CAN_EFF_FLAG) ? "Ext. ID" : "ID";
col_add_fstr(pinfo->cinfo, COL_INFO, "%s: %d (0x%" PRIx32 "), Length: %d", id_name, effective_can_id, effective_can_id, can_info.len);
guint32 effective_can_id = 0; /* Again, XXX */
socketcan_set_source_and_destination_columns(pinfo, &can_info);
col_add_fstr(pinfo->cinfo, COL_INFO, "%s: %d (0x%" PRIx32 "), Length: %d", "ID", effective_can_id, effective_can_id, can_info.len);
ti = proto_tree_add_item(tree, proto_can, tvb, 0, -1, ENC_NA);
if (can_packet_type == PACKET_TYPE_CAN_FD) {
socketcan_set_source_and_destination_columns(pinfo, &can_info);
ti = proto_tree_add_item(tree, proto_can, tvb, 0, -1, ENC_NA);
proto_item_set_hidden(ti);
ti = proto_tree_add_item(tree, proto_canfd, tvb, 0, -1, ENC_NA);
}
can_tree = proto_item_add_subtree(ti, (can_packet_type == PACKET_TYPE_CAN_FD) ? ett_can_fd : ett_can);
ti = proto_tree_add_item(tree, proto_canxl, tvb, 0, -1, ENC_NA);
can_tree = proto_item_add_subtree(ti, ett_can_xl);
proto_item_append_text(can_tree, ", %s: %d (0x%" PRIx32 "), Length: %d", id_name, effective_can_id, effective_can_id, can_info.len);
proto_item_append_text(can_tree, ", %s: %d (0x%" PRIx32 "), Length: %d", "ID", effective_can_id, effective_can_id, can_info.len);
proto_tree_add_bitmask_list(can_tree, tvb, 0, 4, can_flags, encoding);
proto_tree_add_item(can_tree, hf_can_len, tvb, CAN_LEN_OFFSET, 1, ENC_NA);
proto_tree_add_bitmask_list(can_tree, tvb, 0, 4, canxl_prio_vcid_fields, xl_encoding);
proto_tree_add_bitmask_list(can_tree, tvb, 4, 1, canxl_flag_fields, xl_encoding);
proto_tree_add_item(can_tree, hf_canxl_sdu_type, tvb, 5, 1, ENC_NA);
proto_tree_add_item(can_tree, hf_can_len, tvb, CANXL_LEN_OFFSET, 2, xl_encoding);
proto_tree_add_item(can_tree, hf_canxl_acceptance_field, tvb, CANXL_LEN_OFFSET+2, 4, xl_encoding);
if (frame_type == LINUX_CAN_ERR && can_info.len != CAN_ERR_DLC) {
proto_tree_add_expert(tree, pinfo, &ei_can_err_dlc_mismatch, tvb, CAN_LEN_OFFSET, 1);
}
if (can_packet_type == PACKET_TYPE_CAN_FD) {
proto_tree_add_bitmask_list(can_tree, tvb, CANFD_FLAG_OFFSET, 1, canfd_flag_fields, ENC_NA);
proto_tree_add_item(can_tree, hf_can_reserved, tvb, CANFD_FLAG_OFFSET+1, 2, ENC_NA);
} else {
proto_tree_add_item(can_tree, hf_can_reserved, tvb, CANFD_FLAG_OFFSET, 3, ENC_NA);
}
if (frame_type == LINUX_CAN_ERR) {
int * const *flag;
const char *sepa = ": ";
col_set_str(pinfo->cinfo, COL_INFO, "ERR");
for (flag = can_err_flags; *flag; flag++) {
header_field_info *hfi;
hfi = proto_registrar_get_nth(**flag);
if (!hfi)
continue;
if ((can_info.id & hfi->bitmask & ~CAN_FLAG_MASK) == 0)
continue;
col_append_sep_str(pinfo->cinfo, COL_INFO, sepa, hfi->name);
sepa = ", ";
}
if (can_info.id & CAN_ERR_LOSTARB) {
proto_tree_add_item(can_tree, hf_can_err_lostarb_bit_number, tvb, CAN_DATA_OFFSET + 0, 1, ENC_NA);
}
if (can_info.id & CAN_ERR_CTRL) {
static int * const can_err_ctrl_flags[] = {
&hf_can_err_ctrl_rx_overflow,
&hf_can_err_ctrl_tx_overflow,
&hf_can_err_ctrl_rx_warning,
&hf_can_err_ctrl_tx_warning,
&hf_can_err_ctrl_rx_passive,
&hf_can_err_ctrl_tx_passive,
&hf_can_err_ctrl_active,
NULL,
};
proto_tree_add_bitmask_list(can_tree, tvb, CAN_DATA_OFFSET+1, 1, can_err_ctrl_flags, ENC_NA);
}
if (can_info.id & CAN_ERR_PROT) {
static int * const can_err_prot_error_type_flags[] = {
&hf_can_err_prot_error_type_bit,
&hf_can_err_prot_error_type_form,
&hf_can_err_prot_error_type_stuff,
&hf_can_err_prot_error_type_bit0,
&hf_can_err_prot_error_type_bit1,
&hf_can_err_prot_error_type_overload,
&hf_can_err_prot_error_type_active,
&hf_can_err_prot_error_type_tx,
NULL
};
proto_tree_add_bitmask_list(can_tree, tvb, CAN_DATA_OFFSET+2, 1, can_err_prot_error_type_flags, ENC_NA);
proto_tree_add_item(can_tree, hf_can_err_prot_error_location, tvb, CAN_DATA_OFFSET+3, 1, ENC_NA);
}
if (can_info.id & CAN_ERR_TRX) {
proto_tree_add_item(can_tree, hf_can_err_trx_canh, tvb, CAN_DATA_OFFSET+4, 1, ENC_NA);
proto_tree_add_item(can_tree, hf_can_err_trx_canl, tvb, CAN_DATA_OFFSET+4, 1, ENC_NA);
}
proto_tree_add_item(can_tree, hf_can_err_ctrl_specific, tvb, CAN_DATA_OFFSET+5, 3, ENC_NA);
} else {
tvbuff_t *next_tvb;
if (can_info.id & CAN_RTR_FLAG) {
col_append_str(pinfo->cinfo, COL_INFO, "(Remote Transmission Request)");
}
next_tvb = tvb_new_subset_length(tvb, CAN_DATA_OFFSET, can_info.len);
next_tvb = tvb_new_subset_length(tvb, CANXL_DATA_OFFSET, can_info.len);
if (!socketcan_call_subdissectors(next_tvb, pinfo, tree, &can_info, heuristic_first)) {
call_data_dissector(next_tvb, pinfo, tree);
}
}
if (tvb_captured_length_remaining(tvb, CAN_DATA_OFFSET+can_info.len) > 0) {
proto_tree_add_item(can_tree, hf_can_padding, tvb, CAN_DATA_OFFSET+can_info.len, -1, ENC_NA);
if (tvb_captured_length_remaining(tvb, CANXL_DATA_OFFSET+can_info.len) > 0) {
proto_tree_add_item(can_tree, hf_can_padding, tvb, CANXL_DATA_OFFSET+can_info.len, -1, ENC_NA);
}
} else {
can_info.id = tvb_get_guint32(tvb, 0, encoding);
can_info.len = tvb_get_guint8(tvb, CAN_LEN_OFFSET);
if (can_packet_type == PACKET_TYPE_CAN_FD) {
can_info.fd = CAN_TYPE_CAN_FD;
col_set_str(pinfo->cinfo, COL_PROTOCOL, "CANFD");
} else {
can_info.fd = CAN_TYPE_CAN_CLASSIC;
col_set_str(pinfo->cinfo, COL_PROTOCOL, "CAN");
}
col_clear(pinfo->cinfo, COL_INFO);
guint32 effective_can_id = (can_info.id & CAN_EFF_FLAG) ? can_info.id & CAN_EFF_MASK : can_info.id & CAN_SFF_MASK;
char *id_name = (can_info.id & CAN_EFF_FLAG) ? "Ext. ID" : "ID";
/* Error Message Frames are only encapsulated in Classic CAN frames */
if (can_packet_type == PACKET_TYPE_CAN && (can_info.id & CAN_ERR_FLAG)) {
frame_type = LINUX_CAN_ERR;
can_flags = can_err_flags;
} else if (can_info.id & CAN_EFF_FLAG) {
frame_type = LINUX_CAN_EXT;
can_info.id &= (CAN_EFF_MASK | CAN_FLAG_MASK);
can_flags = (can_packet_type == PACKET_TYPE_CAN_FD) ? can_ext_flags_fd : can_ext_flags;
} else {
frame_type = LINUX_CAN_STD;
can_info.id &= (CAN_SFF_MASK | CAN_FLAG_MASK);
can_flags = (can_packet_type == PACKET_TYPE_CAN_FD) ? can_std_flags_fd : can_std_flags;
}
col_add_fstr(pinfo->cinfo, COL_INFO, "%s: %d (0x%" PRIx32 "), Length: %d", id_name, effective_can_id, effective_can_id, can_info.len);
socketcan_set_source_and_destination_columns(pinfo, &can_info);
ti = proto_tree_add_item(tree, proto_can, tvb, 0, -1, ENC_NA);
if (can_packet_type == PACKET_TYPE_CAN_FD) {
proto_item_set_hidden(ti);
ti = proto_tree_add_item(tree, proto_canfd, tvb, 0, -1, ENC_NA);
}
can_tree = proto_item_add_subtree(ti, (can_packet_type == PACKET_TYPE_CAN_FD) ? ett_can_fd : ett_can);
proto_item_append_text(can_tree, ", %s: %d (0x%" PRIx32 "), Length: %d", id_name, effective_can_id, effective_can_id, can_info.len);
proto_tree_add_bitmask_list(can_tree, tvb, 0, 4, can_flags, encoding);
proto_tree_add_item(can_tree, hf_can_len, tvb, CAN_LEN_OFFSET, 1, ENC_NA);
if (frame_type == LINUX_CAN_ERR && can_info.len != CAN_ERR_DLC) {
proto_tree_add_expert(tree, pinfo, &ei_can_err_dlc_mismatch, tvb, CAN_LEN_OFFSET, 1);
}
if (can_packet_type == PACKET_TYPE_CAN_FD) {
proto_tree_add_bitmask_list(can_tree, tvb, CANFD_FLAG_OFFSET, 1, canfd_flag_fields, ENC_NA);
proto_tree_add_item(can_tree, hf_can_reserved, tvb, CANFD_FLAG_OFFSET+1, 2, ENC_NA);
} else {
proto_tree_add_item(can_tree, hf_can_reserved, tvb, CANFD_FLAG_OFFSET, 3, ENC_NA);
}
if (frame_type == LINUX_CAN_ERR) {
int * const *flag;
const char *sepa = ": ";
col_set_str(pinfo->cinfo, COL_INFO, "ERR");
for (flag = can_err_flags; *flag; flag++) {
header_field_info *hfi;
hfi = proto_registrar_get_nth(**flag);
if (!hfi)
continue;
if ((can_info.id & hfi->bitmask & ~CAN_FLAG_MASK) == 0)
continue;
col_append_sep_str(pinfo->cinfo, COL_INFO, sepa, hfi->name);
sepa = ", ";
}
if (can_info.id & CAN_ERR_LOSTARB) {
proto_tree_add_item(can_tree, hf_can_err_lostarb_bit_number, tvb, CAN_DATA_OFFSET + 0, 1, ENC_NA);
}
if (can_info.id & CAN_ERR_CTRL) {
static int * const can_err_ctrl_flags[] = {
&hf_can_err_ctrl_rx_overflow,
&hf_can_err_ctrl_tx_overflow,
&hf_can_err_ctrl_rx_warning,
&hf_can_err_ctrl_tx_warning,
&hf_can_err_ctrl_rx_passive,
&hf_can_err_ctrl_tx_passive,
&hf_can_err_ctrl_active,
NULL,
};
proto_tree_add_bitmask_list(can_tree, tvb, CAN_DATA_OFFSET+1, 1, can_err_ctrl_flags, ENC_NA);
}
if (can_info.id & CAN_ERR_PROT) {
static int * const can_err_prot_error_type_flags[] = {
&hf_can_err_prot_error_type_bit,
&hf_can_err_prot_error_type_form,
&hf_can_err_prot_error_type_stuff,
&hf_can_err_prot_error_type_bit0,
&hf_can_err_prot_error_type_bit1,
&hf_can_err_prot_error_type_overload,
&hf_can_err_prot_error_type_active,
&hf_can_err_prot_error_type_tx,
NULL
};
proto_tree_add_bitmask_list(can_tree, tvb, CAN_DATA_OFFSET+2, 1, can_err_prot_error_type_flags, ENC_NA);
proto_tree_add_item(can_tree, hf_can_err_prot_error_location, tvb, CAN_DATA_OFFSET+3, 1, ENC_NA);
}
if (can_info.id & CAN_ERR_TRX) {
proto_tree_add_item(can_tree, hf_can_err_trx_canh, tvb, CAN_DATA_OFFSET+4, 1, ENC_NA);
proto_tree_add_item(can_tree, hf_can_err_trx_canl, tvb, CAN_DATA_OFFSET+4, 1, ENC_NA);
}
proto_tree_add_item(can_tree, hf_can_err_ctrl_specific, tvb, CAN_DATA_OFFSET+5, 3, ENC_NA);
} else {
tvbuff_t *next_tvb;
if (can_info.id & CAN_RTR_FLAG) {
col_append_str(pinfo->cinfo, COL_INFO, "(Remote Transmission Request)");
}
next_tvb = tvb_new_subset_length(tvb, CAN_DATA_OFFSET, can_info.len);
if (!socketcan_call_subdissectors(next_tvb, pinfo, tree, &can_info, heuristic_first)) {
call_data_dissector(next_tvb, pinfo, tree);
}
}
if (tvb_captured_length_remaining(tvb, CAN_DATA_OFFSET+can_info.len) > 0) {
proto_tree_add_item(can_tree, hf_can_padding, tvb, CAN_DATA_OFFSET+can_info.len, -1, ENC_NA);
}
}
return tvb_captured_length(tvb);
@ -721,19 +834,33 @@ dissect_socketcan_common(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, gu
static int
dissect_socketcan_bigendian(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_) {
return dissect_socketcan_common(tvb, pinfo, tree,
byte_swap ? ENC_LITTLE_ENDIAN : ENC_BIG_ENDIAN, PACKET_TYPE_UNKNOWN);
byte_swap ? ENC_LITTLE_ENDIAN : ENC_BIG_ENDIAN,
byte_swap ? ENC_BIG_ENDIAN : ENC_LITTLE_ENDIAN,
PACKET_TYPE_UNKNOWN);
}
static int
dissect_socketcan_classic(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_) {
return dissect_socketcan_common(tvb, pinfo, tree,
byte_swap ? ENC_ANTI_HOST_ENDIAN : ENC_HOST_ENDIAN, PACKET_TYPE_CAN);
byte_swap ? ENC_ANTI_HOST_ENDIAN : ENC_HOST_ENDIAN,
byte_swap ? ENC_ANTI_HOST_ENDIAN : ENC_HOST_ENDIAN,
PACKET_TYPE_CAN);
}
static int
dissect_socketcan_fd(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_) {
return dissect_socketcan_common(tvb, pinfo, tree,
byte_swap ? ENC_ANTI_HOST_ENDIAN : ENC_HOST_ENDIAN, PACKET_TYPE_CAN_FD);
byte_swap ? ENC_ANTI_HOST_ENDIAN : ENC_HOST_ENDIAN,
byte_swap ? ENC_ANTI_HOST_ENDIAN : ENC_HOST_ENDIAN,
PACKET_TYPE_CAN_FD);
}
static int
dissect_socketcan_xl(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_) {
return dissect_socketcan_common(tvb, pinfo, tree,
byte_swap ? ENC_ANTI_HOST_ENDIAN : ENC_HOST_ENDIAN,
byte_swap ? ENC_ANTI_HOST_ENDIAN : ENC_HOST_ENDIAN,
PACKET_TYPE_CAN_XL);
}
void
@ -819,6 +946,18 @@ proto_register_socketcan(void) {
"Transceiver CANL status", "can.err.trx.canl", FT_UINT8, BASE_DEC, VALS(can_err_trx_canl_vals), 0xF0, NULL, HFILL } },
{ &hf_can_err_ctrl_specific, {
"Controller specific data", "can.err.ctrl_specific", FT_BYTES, SEP_SPACE, NULL, 0, NULL, HFILL } },
{ &hf_canxl_priority, {
"Priority", "canxl.priority", FT_UINT32, BASE_DEC, NULL, 0x0000FFFF, NULL, HFILL } },
{ &hf_canxl_vcid, {
"VCID", "canxl.vcid", FT_UINT32, BASE_DEC, NULL, 0x00FF0000, NULL, HFILL } },
{ &hf_canxl_secflag, {
"Simple Extended Context", "canxl.flags.sec", FT_BOOLEAN, 8, NULL, CANXL_SEC, NULL, HFILL } },
{ &hf_canxl_sdu_type, {
"SDU type", "canxl.sdu_type", FT_UINT8, BASE_HEX, VALS(canxl_sdu_type_vals), 0, NULL, HFILL } },
{ &hf_canxl_len, {
"Frame-Length", "canxl.len", FT_UINT16, BASE_DEC, NULL, 0x0, NULL, HFILL } },
{ &hf_canxl_acceptance_field, {
"Acceptance field", "canxl.acceptance_field", FT_UINT32, BASE_DEC_HEX, NULL, 0, NULL, HFILL } },
};
uat_t *can_interface_uat = NULL;
@ -827,7 +966,8 @@ proto_register_socketcan(void) {
/* Setup protocol subtree array */
static gint *ett[] = {
&ett_can,
&ett_can_fd
&ett_can_fd,
&ett_can_xl
};
static ei_register_info ei[] = {
@ -846,6 +986,11 @@ proto_register_socketcan(void) {
* or Busmaster capture that was saved as a pcap or pcapng file,
* as those use a linktype of LINKTYPE_WIRESHARK_UPPER_PDU with
* "can-hostendian" as the dissector name.
*
* "can-bigendian" is also a legacy name (fpr CAN XL frames, the
* fields in the header are in *little-endian* order); we keep it
* around for the same reason. It's used for the dissector for
* LINKTYPE_CAN_SOCKETCAN.
*/
socketcan_classic_handle = register_dissector("can-hostendian", dissect_socketcan_classic, proto_can);
socketcan_bigendian_handle = register_dissector("can-bigendian", dissect_socketcan_bigendian, proto_can);
@ -853,6 +998,9 @@ proto_register_socketcan(void) {
proto_canfd = proto_register_protocol("Controller Area Network FD", "CANFD", "canfd");
socketcan_fd_handle = register_dissector("canfd", dissect_socketcan_fd, proto_canfd);
proto_canxl = proto_register_protocol("Controller Area Network XL", "CANXL", "canxl");
socketcan_xl_handle = register_dissector("canxl", dissect_socketcan_xl, proto_canxl);
proto_register_field_array(proto_can, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
@ -938,6 +1086,7 @@ proto_reg_handoff_socketcan(void) {
dissector_add_uint("sll.ltype", LINUX_SLL_P_CAN, socketcan_classic_handle);
dissector_add_uint("sll.ltype", LINUX_SLL_P_CANFD, socketcan_fd_handle);
dissector_add_uint("sll.ltype", LINUX_SLL_P_CANXL, socketcan_xl_handle);
}
/*

36
epan/dissectors/packet-socketcan.h
View File

@ -14,16 +14,48 @@
#include <epan/packet_info.h>
#include <epan/proto.h>
/* Flags for CAN FD frames. */
/*
* Flags for CAN FD frames.
* They are in the FD Flags field of a CAN FD frame.
*
* CANFD_FDF is in that field. and always set, as well as being present
* but *never* set in what's at the location corresponding to that field
* in a CAN classic frame, so we can distingish between CAN classic and
* CAN FD frames by testing that bit.
*/
#define CANFD_BRS 0x01 /* Bit Rate Switch (second bitrate for payload data) */
#define CANFD_ESI 0x02 /* Error State Indicator of the transmitting node */
#define CANFD_FDF 0x04 /* FD flag - if set, this is an FD frame */
/*
* Flags for CAN XL frames.
* They are in the Flags field of a CAN XL frame.
*
* CANXL_XLF is in that field, and always set. as well as being present
* but *never* set in what's the location corresponding to that field
* in a CAN classic or CAN FD frame, so we can distinguish between CAN
* XL and CAN classic/CAN FD frames by testing that bit.
*/
#define CANXL_XLF 0x80 /* XL flag - if set, this is an XL frame */
#define CANXL_SEC 0x01 /* Simple Extended Content */
/*
* CAN frame type.
*
* CAN_TYPE_CAN_CLASSIC is 0, and CAN_TYPE_CAN_FD is 1, so that the
* fd field behaves, for CAN classic and CAN FD frames, the same way
* that it did when it was a gboolean field that was FALSE for CAN classic
* frames and TRUE for CAN FD frames.
*/
#define CAN_TYPE_CAN_CLASSIC 0
#define CAN_TYPE_CAN_FD 1
#define CAN_TYPE_CAN_XL 2
/* Structure that gets passed between dissectors. */
typedef struct can_info {
guint32 id;
guint32 len;
gboolean fd;
guint fd;
guint16 bus_id;
} can_info_t;

2
epan/dissectors/packet-tecmp.c
View File

@ -1878,7 +1878,7 @@ dissect_tecmp_log_or_replay_stream(tvbuff_t *tvb, packet_info *pinfo, proto_tree
payload_tvb = tvb_new_subset_length(sub_tvb, offset2, length2);
offset2 += length2;
can_info.fd = (data_type == TECMP_DATA_TYPE_CAN_FD_DATA);
can_info.fd = (data_type == TECMP_DATA_TYPE_CAN_FD_DATA) ? CAN_TYPE_CAN_FD : CAN_TYPE_CAN_CLASSIC;
can_info.len = length2;
can_info.bus_id = ht_interface_config_to_bus_id(interface_id);