can: gw: add a per rule limitation of frame hops

Usually the received CAN frames can be processed/routed as much as 'max_hops' times (which is given at module load time of the can-gw module). Introduce a new configuration option to reduce the number of possible hops for a specific gateway rule to a value smaller then max_hops.

Oliver Hartkopp committed 13 years ago

Commit 391ac121 parent 11491082 files · +39 −5Browse files

Showing the changes to include/uapi/linux (1 of 2 files). Show all

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include/uapi/linux/can/gw.h+8−1

@@ -45,6 +45,7 @@ enum { · 44 unmodified lines
45	45	CGW_DST_IF, /* ifindex of destination network interface */
46	46	CGW_FILTER, /* specify struct can_filter on source CAN device */
47	47	CGW_DELETED, /* number of deleted CAN frames (see max_hops param) */
	48	+ CGW_LIM_HOPS, /* limit the number of hops of this specific rule */
48	49	__CGW_MAX
49	50	};
50	51
@@ -116,13 +117,19 @@ enum { · 65 unmodified lines
116	117	* Sets a CAN receive filter for the gateway job specified by the
117	118	* struct can_filter described in include/linux/can.h
118	119	*
119		− * CGW_MOD_XXX (length 17 bytes):
	120	+ * CGW_MOD_(AND\|OR\|XOR\|SET) (length 17 bytes):
120	121	* Specifies a modification that's done to a received CAN frame before it is
121	122	* send out to the destination interface.
122	123	*
123	124	* <struct can_frame> data used as operator
124	125	* <u8> affected CAN frame elements
125	126	*
	127	+ * CGW_LIM_HOPS (length 1 byte):
	128	+ * Limit the number of hops of this specific rule. Usually the received CAN
	129	+ * frame can be processed as much as 'max_hops' times (which is given at module
	130	+ * load time of the can-gw module). This value is used to reduce the number of
	131	+ * possible hops for this gateway rule to a value smaller then max_hops.
	132	+ *
126	133	* CGW_CS_XOR (length 4 bytes):
127	134	* Set a simple XOR checksum starting with an initial value into
128	135	* data[result-idx] using data[start-idx] .. data[end-idx]