From: Oliver Hartkopp <socketcan@xxxxxxxxxxxx> CAN XL data frames contain an 8-bit virtual CAN network identifier (VCID). A VCID value of zero represents an 'untagged' CAN XL frame. To receive and send these optional VCIDs via CAN_RAW sockets a new socket option CAN_RAW_XL_VCID_OPTS is introduced to define/access VCID content: - tx: set the outgoing VCID value by the kernel (one fixed 8-bit value) - tx: pass through VCID values from the user space (e.g. for traffic replay) - rx: apply VCID receive filter (value/mask) to be passed to the user space With the 'tx pass through' option CAN_RAW_XL_VCID_TX_PASS all valid VCID values can be sent, e.g. to replay full qualified CAN XL traffic. The VCID value provided for the CAN_RAW_XL_VCID_TX_SET option will override the VCID value in the struct canxl_frame.prio defined for CAN_RAW_XL_VCID_TX_PASS when both flags are set. With a rx_vcid_mask of zero all possible VCID values (0x00 - 0xFF) are passed to the user space when the CAN_RAW_XL_VCID_RX_FILTER flag is set. Without this flag only untagged CAN XL frames (VCID = 0x00) are delivered to the user space (default). The 8-bit VCID is stored inside the CAN XL prio element (only in CAN XL frames!) to not interfere with other CAN content or the CAN filters provided by the CAN_RAW sockets and kernel infrastruture. Signed-off-by: Oliver Hartkopp <socketcan@xxxxxxxxxxxx> Link: https://lore.kernel.org/all/20240212213550.18516-1-socketcan@xxxxxxxxxxxx Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx> --- include/uapi/linux/can.h | 9 +++- include/uapi/linux/can/raw.h | 16 +++++++ net/can/af_can.c | 2 + net/can/raw.c | 93 ++++++++++++++++++++++++++++++++---- 4 files changed, 110 insertions(+), 10 deletions(-) diff --git a/include/uapi/linux/can.h b/include/uapi/linux/can.h index 939db2388208..e78cbd85ce7c 100644 --- a/include/uapi/linux/can.h +++ b/include/uapi/linux/can.h @@ -193,9 +193,14 @@ struct canfd_frame { #define CANXL_XLF 0x80 /* mandatory CAN XL frame flag (must always be set!) */ #define CANXL_SEC 0x01 /* Simple Extended Content (security/segmentation) */ +/* the 8-bit VCID is optionally placed in the canxl_frame.prio element */ +#define CANXL_VCID_OFFSET 16 /* bit offset of VCID in prio element */ +#define CANXL_VCID_VAL_MASK 0xFFUL /* VCID is an 8-bit value */ +#define CANXL_VCID_MASK (CANXL_VCID_VAL_MASK << CANXL_VCID_OFFSET) + /** * struct canxl_frame - CAN with e'X'tended frame 'L'ength frame structure - * @prio: 11 bit arbitration priority with zero'ed CAN_*_FLAG flags + * @prio: 11 bit arbitration priority with zero'ed CAN_*_FLAG flags / VCID * @flags: additional flags for CAN XL * @sdt: SDU (service data unit) type * @len: frame payload length in byte (CANXL_MIN_DLEN .. CANXL_MAX_DLEN) @@ -205,7 +210,7 @@ struct canfd_frame { * @prio shares the same position as @can_id from struct can[fd]_frame. */ struct canxl_frame { - canid_t prio; /* 11 bit priority for arbitration (canid_t) */ + canid_t prio; /* 11 bit priority for arbitration / 8 bit VCID */ __u8 flags; /* additional flags for CAN XL */ __u8 sdt; /* SDU (service data unit) type */ __u16 len; /* frame payload length in byte */ diff --git a/include/uapi/linux/can/raw.h b/include/uapi/linux/can/raw.h index 31622c9b7988..e024d896e278 100644 --- a/include/uapi/linux/can/raw.h +++ b/include/uapi/linux/can/raw.h @@ -65,6 +65,22 @@ enum { CAN_RAW_FD_FRAMES, /* allow CAN FD frames (default:off) */ CAN_RAW_JOIN_FILTERS, /* all filters must match to trigger */ CAN_RAW_XL_FRAMES, /* allow CAN XL frames (default:off) */ + CAN_RAW_XL_VCID_OPTS, /* CAN XL VCID configuration options */ }; +/* configuration for CAN XL virtual CAN identifier (VCID) handling */ +struct can_raw_vcid_options { + + __u8 flags; /* flags for vcid (filter) behaviour */ + __u8 tx_vcid; /* VCID value set into canxl_frame.prio */ + __u8 rx_vcid; /* VCID value for VCID filter */ + __u8 rx_vcid_mask; /* VCID mask for VCID filter */ + +}; + +/* can_raw_vcid_options.flags for CAN XL virtual CAN identifier handling */ +#define CAN_RAW_XL_VCID_TX_SET 0x01 +#define CAN_RAW_XL_VCID_TX_PASS 0x02 +#define CAN_RAW_XL_VCID_RX_FILTER 0x04 + #endif /* !_UAPI_CAN_RAW_H */ diff --git a/net/can/af_can.c b/net/can/af_can.c index 7343fd487dbe..707576eeeb58 100644 --- a/net/can/af_can.c +++ b/net/can/af_can.c @@ -865,6 +865,8 @@ static __init int can_init(void) /* check for correct padding to be able to use the structs similarly */ BUILD_BUG_ON(offsetof(struct can_frame, len) != offsetof(struct canfd_frame, len) || + offsetof(struct can_frame, len) != + offsetof(struct canxl_frame, flags) || offsetof(struct can_frame, data) != offsetof(struct canfd_frame, data)); diff --git a/net/can/raw.c b/net/can/raw.c index e6b822624ba2..cb8e6f788af8 100644 --- a/net/can/raw.c +++ b/net/can/raw.c @@ -91,6 +91,10 @@ struct raw_sock { int recv_own_msgs; int fd_frames; int xl_frames; + struct can_raw_vcid_options raw_vcid_opts; + canid_t tx_vcid_shifted; + canid_t rx_vcid_shifted; + canid_t rx_vcid_mask_shifted; int join_filters; int count; /* number of active filters */ struct can_filter dfilter; /* default/single filter */ @@ -134,10 +138,29 @@ static void raw_rcv(struct sk_buff *oskb, void *data) return; /* make sure to not pass oversized frames to the socket */ - if ((!ro->fd_frames && can_is_canfd_skb(oskb)) || - (!ro->xl_frames && can_is_canxl_skb(oskb))) + if (!ro->fd_frames && can_is_canfd_skb(oskb)) return; + if (can_is_canxl_skb(oskb)) { + struct canxl_frame *cxl = (struct canxl_frame *)oskb->data; + + /* make sure to not pass oversized frames to the socket */ + if (!ro->xl_frames) + return; + + /* filter CAN XL VCID content */ + if (ro->raw_vcid_opts.flags & CAN_RAW_XL_VCID_RX_FILTER) { + /* apply VCID filter if user enabled the filter */ + if ((cxl->prio & ro->rx_vcid_mask_shifted) != + (ro->rx_vcid_shifted & ro->rx_vcid_mask_shifted)) + return; + } else { + /* no filter => do not forward VCID tagged frames */ + if (cxl->prio & CANXL_VCID_MASK) + return; + } + } + /* eliminate multiple filter matches for the same skb */ if (this_cpu_ptr(ro->uniq)->skb == oskb && this_cpu_ptr(ro->uniq)->skbcnt == can_skb_prv(oskb)->skbcnt) { @@ -698,6 +721,19 @@ static int raw_setsockopt(struct socket *sock, int level, int optname, ro->fd_frames = ro->xl_frames; break; + case CAN_RAW_XL_VCID_OPTS: + if (optlen != sizeof(ro->raw_vcid_opts)) + return -EINVAL; + + if (copy_from_sockptr(&ro->raw_vcid_opts, optval, optlen)) + return -EFAULT; + + /* prepare 32 bit values for handling in hot path */ + ro->tx_vcid_shifted = ro->raw_vcid_opts.tx_vcid << CANXL_VCID_OFFSET; + ro->rx_vcid_shifted = ro->raw_vcid_opts.rx_vcid << CANXL_VCID_OFFSET; + ro->rx_vcid_mask_shifted = ro->raw_vcid_opts.rx_vcid_mask << CANXL_VCID_OFFSET; + break; + case CAN_RAW_JOIN_FILTERS: if (optlen != sizeof(ro->join_filters)) return -EINVAL; @@ -786,6 +822,21 @@ static int raw_getsockopt(struct socket *sock, int level, int optname, val = &ro->xl_frames; break; + case CAN_RAW_XL_VCID_OPTS: + /* user space buffer to small for VCID opts? */ + if (len < sizeof(ro->raw_vcid_opts)) { + /* return -ERANGE and needed space in optlen */ + err = -ERANGE; + if (put_user(sizeof(ro->raw_vcid_opts), optlen)) + err = -EFAULT; + } else { + if (len > sizeof(ro->raw_vcid_opts)) + len = sizeof(ro->raw_vcid_opts); + if (copy_to_user(optval, &ro->raw_vcid_opts, len)) + err = -EFAULT; + } + break; + case CAN_RAW_JOIN_FILTERS: if (len > sizeof(int)) len = sizeof(int); @@ -803,23 +854,41 @@ static int raw_getsockopt(struct socket *sock, int level, int optname, return 0; } -static bool raw_bad_txframe(struct raw_sock *ro, struct sk_buff *skb, int mtu) +static void raw_put_canxl_vcid(struct raw_sock *ro, struct sk_buff *skb) +{ + struct canxl_frame *cxl = (struct canxl_frame *)skb->data; + + /* sanitize non CAN XL bits */ + cxl->prio &= (CANXL_PRIO_MASK | CANXL_VCID_MASK); + + /* clear VCID in CAN XL frame if pass through is disabled */ + if (!(ro->raw_vcid_opts.flags & CAN_RAW_XL_VCID_TX_PASS)) + cxl->prio &= CANXL_PRIO_MASK; + + /* set VCID in CAN XL frame if enabled */ + if (ro->raw_vcid_opts.flags & CAN_RAW_XL_VCID_TX_SET) { + cxl->prio &= CANXL_PRIO_MASK; + cxl->prio |= ro->tx_vcid_shifted; + } +} + +static unsigned int raw_check_txframe(struct raw_sock *ro, struct sk_buff *skb, int mtu) { /* Classical CAN -> no checks for flags and device capabilities */ if (can_is_can_skb(skb)) - return false; + return CAN_MTU; /* CAN FD -> needs to be enabled and a CAN FD or CAN XL device */ if (ro->fd_frames && can_is_canfd_skb(skb) && (mtu == CANFD_MTU || can_is_canxl_dev_mtu(mtu))) - return false; + return CANFD_MTU; /* CAN XL -> needs to be enabled and a CAN XL device */ if (ro->xl_frames && can_is_canxl_skb(skb) && can_is_canxl_dev_mtu(mtu)) - return false; + return CANXL_MTU; - return true; + return 0; } static int raw_sendmsg(struct socket *sock, struct msghdr *msg, size_t size) @@ -829,6 +898,7 @@ static int raw_sendmsg(struct socket *sock, struct msghdr *msg, size_t size) struct sockcm_cookie sockc; struct sk_buff *skb; struct net_device *dev; + unsigned int txmtu; int ifindex; int err = -EINVAL; @@ -869,9 +939,16 @@ static int raw_sendmsg(struct socket *sock, struct msghdr *msg, size_t size) goto free_skb; err = -EINVAL; - if (raw_bad_txframe(ro, skb, dev->mtu)) + + /* check for valid CAN (CC/FD/XL) frame content */ + txmtu = raw_check_txframe(ro, skb, dev->mtu); + if (!txmtu) goto free_skb; + /* only CANXL: clear/forward/set VCID value */ + if (txmtu == CANXL_MTU) + raw_put_canxl_vcid(ro, skb); + sockcm_init(&sockc, sk); if (msg->msg_controllen) { err = sock_cmsg_send(sk, msg, &sockc); -- 2.43.0
