On 03.08.2011 13:56, uprinz wrote: > > Hi Wolfgang, > > I know that the behavior is normal and under normal conditions everything is > working well. > > But I need to have the virtual slave accepted by the bus even the bus is > passive. Or even the physical bus is passive the master should see it active > if the slave is online. > > The thing is, that the master has some internal sensors that should be > treated like an external slave. > But reading all this, I believe that it would be fare more easy to rewrite > master to be master+slave and give the sensors to him.... > > Nevertheless I thought about setting master and slave to vcan0 and establish > sort of routing vcan0<->can0
Hi Ulrich, indeed we used a similar setup some time ago. The idea is to run the CAN applications on the virtual CAN interface (e.g. vcan0) and then cross-route the CAN frames between vcan0 <-> can0. Even if the can0 interface goes down/up the cross-route remains. Only when you remove can0, all routings from/to can0 are purged. To use the kernel-based CAN routing, you need to build the can-gw protocol which is based on the PF_CAN network layer stuff and currently only sits in the Berlios SVN: http://svn.berlios.de/wsvn/socketcan/trunk/kernel/2.6/net/can/gw.c?op=log&; You also need the configuration tool cangw which is in trunk/can-utils/cangw.c ---8<--- user@linux:~$ cangw -? Usage: cangw [options] Commands: -A (add a new rule) -D (delete a rule) -F (flush / delete all rules) -L (list all rules) Mandatory: -s <src_dev> (source netdevice) -d <dst_dev> (destination netdevice) Options: -t (preserve src_dev rx timestamp) -e (echo sent frames - recommended on vcanx) -f <filter> (set CAN filter) -m <mod> (set frame modifications) -x <from_idx>:<to_idx>:<result_idx>:<init_xor_val> (XOR checksum) -c <from>:<to>:<result>:<init_val>:<xor_val>:<crctab[256]> (CRC8 cs) -p <profile>:[<profile_data>] (CRC8 checksum profile & parameters) Values are given and expected in hexadecimal values. Leading 0s can be omitted. <filter> is a <value><mask> CAN identifier filter <can_id>:<can_mask> (matches when <received_can_id> & mask == can_id & mask) <can_id>~<can_mask> (matches when <received_can_id> & mask != can_id & mask) <mod> is a CAN frame modification instruction consisting of <instruction>:<can_frame-elements>:<can_id>.<can_dlc>.<can_data> - <instruction> is one of 'AND' 'OR' 'XOR' 'SET' - <can_frame-elements> is _one_ or _more_ of 'I'dentifier 'L'ength 'D'ata - <can_id> is an u32 value containing the CAN Identifier - <can_dlc> is an u8 value containing the data length code (0 .. 8) - <can_data> is always eight(!) u8 values containing the CAN frames data The max. four modifications are performed in the order AND -> OR -> XOR -> SET Example: cangw -A -s can0 -d vcan3 -e -f 123:C00007FF -m SET:IL:333.4.1122334455667788 Supported CRC 8 profiles: Profile '1' (1U8) - add one additional u8 value Profile '2' (16U8) - add u8 value from table[16] indexed by (data[1] & 0xF) Profile '3' (SFFID_XOR) - add u8 value (can_id & 0xFF) ^ (can_id >> 8 & 0xFF) ---8<--- The can-gw is pretty fast and efficient, so that you won't see any relevant timing differences. If you get any problems using can-gw or the cangw userspacetool please ask me. I'm always interested in feedback ;-) > > Is that an option, and if, how to do that? I googled for something like ip > route add vcan... Even if can-gw is using netlink i created a separate tool as all the CAN-stuff and filtering is so different to IP and other networking. Best regards, Oliver > No usable hits though. > > ----- > Best regards > Ulrich _______________________________________________ Socketcan-users mailing list [email protected] https://lists.berlios.de/mailman/listinfo/socketcan-users
