From 1a2467ed29302149d4d1253888ac1f1dfcc11d3f Mon Sep 17 00:00:00 2001 From: Oliver Hartkopp Date: Tue, 17 Mar 2015 20:30:54 +0100 Subject: [PATCH] candump: support new raw socket option to join the given CAN filters The CAN_RAW socket can set multiple CAN identifier specific filters that lead to multiple filters in the af_can.c filter processing. These filters are indenpendent from each other which leads to logical OR'ed filters when applied. This socket option joines the given CAN filters in the way that only CAN frames are passed to user space that matched *all* given CAN filters. The semantic for the applied filters is therefore changed to a logical AND. This is useful especially when the filterset is a combination of filters where the CAN_INV_FILTER flag is set in order to notch single CAN IDs or CAN ID ranges from the incoming traffic. Example: candump can0,100~7FF,200~7FF,400~7FF (logical OR'ed filters) candump can0,100~7FF,200~7FF,400~7FF,J (logical AND'ed filters) Signed-off-by: Oliver Hartkopp --- candump.c | 9 +++++++++ include/linux/can/raw.h | 1 + 2 files changed, 10 insertions(+) diff --git a/candump.c b/candump.c index a1146f5..eab9495 100644 --- a/candump.c +++ b/candump.c @@ -131,6 +131,7 @@ void print_usage(char *prg) fprintf(stderr, " : (matches when & mask == can_id & mask)\n"); fprintf(stderr, " ~ (matches when & mask != can_id & mask)\n"); fprintf(stderr, " # (set error frame filter, see include/linux/can/error.h)\n"); + fprintf(stderr, " [j|J] (join the given CAN filters - logical AND semantic)\n"); fprintf(stderr, "\nCAN IDs, masks and data content are given and expected in hexadecimal values.\n"); fprintf(stderr, "When can_id and can_mask are both 8 digits, they are assumed to be 29 bit EFF.\n"); fprintf(stderr, "Without any given filter all data frames are received ('0:0' default filter).\n"); @@ -218,6 +219,7 @@ int main(int argc, char **argv) int rcvbuf_size = 0; int opt, ret; int currmax, numfilter; + int join_filter; char *ptr, *nptr; struct sockaddr_can addr; char ctrlmsg[CMSG_SPACE(sizeof(struct timeval)) + CMSG_SPACE(sizeof(__u32))]; @@ -467,6 +469,7 @@ int main(int argc, char **argv) numfilter = 0; err_mask = 0; + join_filter = 0; while (nptr) { @@ -484,6 +487,8 @@ int main(int argc, char **argv) rfilter[numfilter].can_id |= CAN_INV_FILTER; rfilter[numfilter].can_mask &= ~CAN_ERR_FLAG; numfilter++; + } else if (*ptr == 'j' || *ptr == 'J') { + join_filter = 1; } else if (sscanf(ptr, "#%x", &err_mask) != 1) { fprintf(stderr, "Error in filter option parsing: '%s'\n", ptr); return 1; @@ -498,6 +503,10 @@ int main(int argc, char **argv) setsockopt(s[i], SOL_CAN_RAW, CAN_RAW_FILTER, rfilter, numfilter * sizeof(struct can_filter)); + if (join_filter) + setsockopt(s[i], SOL_CAN_RAW, CAN_RAW_JOIN_FILTERS, + &join_filter, sizeof(join_filter)); + free(rfilter); } /* if (nptr) */ diff --git a/include/linux/can/raw.h b/include/linux/can/raw.h index c7d8c33..c9e7c2e 100644 --- a/include/linux/can/raw.h +++ b/include/linux/can/raw.h @@ -57,6 +57,7 @@ enum { CAN_RAW_LOOPBACK, /* local loopback (default:on) */ CAN_RAW_RECV_OWN_MSGS, /* receive my own msgs (default:off) */ CAN_RAW_FD_FRAMES, /* allow CAN FD frames (default:off) */ + CAN_RAW_JOIN_FILTERS, /* all filters must match to trigger */ }; #endif