diff options
| -rw-r--r-- | Documentation/networking/can.txt | 20 | ||||
| -rw-r--r-- | include/uapi/linux/can/raw.h | 1 | ||||
| -rw-r--r-- | net/can/raw.c | 31 |
3 files changed, 49 insertions, 3 deletions
diff --git a/Documentation/networking/can.txt b/Documentation/networking/can.txt index 0a2859a8ee7e..5abad1e921ca 100644 --- a/Documentation/networking/can.txt +++ b/Documentation/networking/can.txt @@ -22,7 +22,8 @@ This file contains 4.1.3 RAW socket option CAN_RAW_LOOPBACK 4.1.4 RAW socket option CAN_RAW_RECV_OWN_MSGS 4.1.5 RAW socket option CAN_RAW_FD_FRAMES - 4.1.6 RAW socket returned message flags + 4.1.6 RAW socket option CAN_RAW_JOIN_FILTERS + 4.1.7 RAW socket returned message flags 4.2 Broadcast Manager protocol sockets (SOCK_DGRAM) 4.2.1 Broadcast Manager operations 4.2.2 Broadcast Manager message flags @@ -601,7 +602,22 @@ solution for a couple of reasons: CAN FD frames by checking if the device maximum transfer unit is CANFD_MTU. The CAN device MTU can be retrieved e.g. with a SIOCGIFMTU ioctl() syscall. - 4.1.6 RAW socket returned message flags + 4.1.6 RAW socket option CAN_RAW_JOIN_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 (see 4.1.1). + + 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. + + 4.1.7 RAW socket returned message flags When using recvmsg() call, the msg->msg_flags may contain following flags: diff --git a/include/uapi/linux/can/raw.h b/include/uapi/linux/can/raw.h index 78ec76fd89a6..8735f1080385 100644 --- a/include/uapi/linux/can/raw.h +++ b/include/uapi/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 /* !_UAPI_CAN_RAW_H */ diff --git a/net/can/raw.c b/net/can/raw.c index 0c8d537b59b8..31b9748cbb4e 100644 --- a/net/can/raw.c +++ b/net/can/raw.c @@ -77,6 +77,7 @@ MODULE_ALIAS("can-proto-1"); struct uniqframe { ktime_t tstamp; const struct sk_buff *skb; + unsigned int join_rx_count; }; struct raw_sock { @@ -87,6 +88,7 @@ struct raw_sock { int loopback; int recv_own_msgs; int fd_frames; + int join_filters; int count; /* number of active filters */ struct can_filter dfilter; /* default/single filter */ struct can_filter *filter; /* pointer to filter(s) */ @@ -132,10 +134,21 @@ static void raw_rcv(struct sk_buff *oskb, void *data) /* eliminate multiple filter matches for the same skb */ if (this_cpu_ptr(ro->uniq)->skb == oskb && ktime_equal(this_cpu_ptr(ro->uniq)->tstamp, oskb->tstamp)) { - return; + if (ro->join_filters) { + this_cpu_inc(ro->uniq->join_rx_count); + /* drop frame until all enabled filters matched */ + if (this_cpu_ptr(ro->uniq)->join_rx_count < ro->count) + return; + } else { + return; + } } else { this_cpu_ptr(ro->uniq)->skb = oskb; this_cpu_ptr(ro->uniq)->tstamp = oskb->tstamp; + this_cpu_ptr(ro->uniq)->join_rx_count = 1; + /* drop first frame to check all enabled filters? */ + if (ro->join_filters && ro->count > 1) + return; } /* clone the given skb to be able to enqueue it into the rcv queue */ @@ -311,6 +324,7 @@ static int raw_init(struct sock *sk) ro->loopback = 1; ro->recv_own_msgs = 0; ro->fd_frames = 0; + ro->join_filters = 0; /* alloc_percpu provides zero'ed memory */ ro->uniq = alloc_percpu(struct uniqframe); @@ -604,6 +618,15 @@ static int raw_setsockopt(struct socket *sock, int level, int optname, break; + case CAN_RAW_JOIN_FILTERS: + if (optlen != sizeof(ro->join_filters)) + return -EINVAL; + + if (copy_from_user(&ro->join_filters, optval, optlen)) + return -EFAULT; + + break; + default: return -ENOPROTOOPT; } @@ -668,6 +691,12 @@ static int raw_getsockopt(struct socket *sock, int level, int optname, val = &ro->fd_frames; break; + case CAN_RAW_JOIN_FILTERS: + if (len > sizeof(int)) + len = sizeof(int); + val = &ro->join_filters; + break; + default: return -ENOPROTOOPT; } |