From d6e640f9766e2fb9aa3853b4ff19e4d7d5d7e373 Mon Sep 17 00:00:00 2001 From: Oliver Hartkopp Date: Tue, 8 May 2012 22:20:33 +0200 Subject: can: update documentation wording error frames -> error messages As Heinz-Juergen Oertel pointed out 'CAN error frames' are a already defined term for the CAN protocol violation indication on the wire. To avoid confusion with the error messages created by CAN drivers available via CAN RAW sockets update the documentation and change the naming from 'error frames' to 'error messages' or 'error message frames'. Signed-off-by: Oliver Hartkopp Signed-off-by: Marc Kleine-Budde --- include/linux/can.h | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'include/linux/can.h') diff --git a/include/linux/can.h b/include/linux/can.h index 9a19bcb3eea..17334c09bd9 100644 --- a/include/linux/can.h +++ b/include/linux/can.h @@ -21,7 +21,7 @@ /* special address description flags for the CAN_ID */ #define CAN_EFF_FLAG 0x80000000U /* EFF/SFF is set in the MSB */ #define CAN_RTR_FLAG 0x40000000U /* remote transmission request */ -#define CAN_ERR_FLAG 0x20000000U /* error frame */ +#define CAN_ERR_FLAG 0x20000000U /* error message frame */ /* valid bits in CAN ID for frame formats */ #define CAN_SFF_MASK 0x000007FFU /* standard frame format (SFF) */ @@ -32,14 +32,14 @@ * Controller Area Network Identifier structure * * bit 0-28 : CAN identifier (11/29 bit) - * bit 29 : error frame flag (0 = data frame, 1 = error frame) + * bit 29 : error message frame flag (0 = data frame, 1 = error message) * bit 30 : remote transmission request flag (1 = rtr frame) * bit 31 : frame format flag (0 = standard 11 bit, 1 = extended 29 bit) */ typedef __u32 canid_t; /* - * Controller Area Network Error Frame Mask structure + * Controller Area Network Error Message Frame Mask structure * * bit 0-28 : error class mask (see include/linux/can/error.h) * bit 29-31 : set to zero @@ -97,7 +97,7 @@ struct sockaddr_can { * & mask == can_id & mask * * The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can - * filter for error frames (CAN_ERR_FLAG bit set in mask). + * filter for error message frames (CAN_ERR_FLAG bit set in mask). */ struct can_filter { canid_t can_id; -- cgit v1.2.3-70-g09d2 From 7c9416365c60f150ef8961a2855fafbc7394ad6b Mon Sep 17 00:00:00 2001 From: Oliver Hartkopp Date: Wed, 13 Jun 2012 20:04:33 +0200 Subject: canfd: add new data structures and constants - add new struct canfd_frame - check identical element offsets in struct can_frame and struct canfd_frame - new ETH_P_CANFD definition to tag CAN FD skbs correctly - add CAN_MTU and CANFD_MTU definitions for easy frame and mode detection - add CAN[FD]_MAX_[DLC|DLEN] helper constants to remove hard coded values - update existing struct can_frame with helper constants and comments Signed-off-by: Oliver Hartkopp Signed-off-by: Marc Kleine-Budde --- include/linux/can.h | 59 ++++++++++++++++++++++++++++++++++++++++++++---- include/linux/if_ether.h | 3 ++- net/can/af_can.c | 7 ++++++ 3 files changed, 63 insertions(+), 6 deletions(-) (limited to 'include/linux/can.h') diff --git a/include/linux/can.h b/include/linux/can.h index 17334c09bd9..1a66cf6112a 100644 --- a/include/linux/can.h +++ b/include/linux/can.h @@ -46,18 +46,67 @@ typedef __u32 canid_t; */ typedef __u32 can_err_mask_t; +/* CAN payload length and DLC definitions according to ISO 11898-1 */ +#define CAN_MAX_DLC 8 +#define CAN_MAX_DLEN 8 + +/* CAN FD payload length and DLC definitions according to ISO 11898-7 */ +#define CANFD_MAX_DLC 15 +#define CANFD_MAX_DLEN 64 + /** * struct can_frame - basic CAN frame structure - * @can_id: the CAN ID of the frame and CAN_*_FLAG flags, see above. - * @can_dlc: the data length field of the CAN frame - * @data: the CAN frame payload. + * @can_id: CAN ID of the frame and CAN_*_FLAG flags, see canid_t definition + * @can_dlc: frame payload length in byte (0 .. 8) aka data length code + * N.B. the DLC field from ISO 11898-1 Chapter 8.4.2.3 has a 1:1 + * mapping of the 'data length code' to the real payload length + * @data: CAN frame payload (up to 8 byte) */ struct can_frame { canid_t can_id; /* 32 bit CAN_ID + EFF/RTR/ERR flags */ - __u8 can_dlc; /* data length code: 0 .. 8 */ - __u8 data[8] __attribute__((aligned(8))); + __u8 can_dlc; /* frame payload length in byte (0 .. CAN_MAX_DLEN) */ + __u8 data[CAN_MAX_DLEN] __attribute__((aligned(8))); }; +/* + * defined bits for canfd_frame.flags + * + * As the default for CAN FD should be to support the high data rate in the + * payload section of the frame (HDR) and to support up to 64 byte in the + * data section (EDL) the bits are only set in the non-default case. + * Btw. as long as there's no real implementation for CAN FD network driver + * these bits are only preliminary. + * + * RX: NOHDR/NOEDL - info about received CAN FD frame + * ESI - bit from originating CAN controller + * TX: NOHDR/NOEDL - control per-frame settings if supported by CAN controller + * ESI - bit is set by local CAN controller + */ +#define CANFD_NOHDR 0x01 /* frame without high data rate */ +#define CANFD_NOEDL 0x02 /* frame without extended data length */ +#define CANFD_ESI 0x04 /* error state indicator */ + +/** + * struct canfd_frame - CAN flexible data rate frame structure + * @can_id: CAN ID of the frame and CAN_*_FLAG flags, see canid_t definition + * @len: frame payload length in byte (0 .. CANFD_MAX_DLEN) + * @flags: additional flags for CAN FD + * @__res0: reserved / padding + * @__res1: reserved / padding + * @data: CAN FD frame payload (up to CANFD_MAX_DLEN byte) + */ +struct canfd_frame { + canid_t can_id; /* 32 bit CAN_ID + EFF/RTR/ERR flags */ + __u8 len; /* frame payload length in byte */ + __u8 flags; /* additional flags for CAN FD */ + __u8 __res0; /* reserved / padding */ + __u8 __res1; /* reserved / padding */ + __u8 data[CANFD_MAX_DLEN] __attribute__((aligned(8))); +}; + +#define CAN_MTU (sizeof(struct can_frame)) +#define CANFD_MTU (sizeof(struct canfd_frame)) + /* particular protocols of the protocol family PF_CAN */ #define CAN_RAW 1 /* RAW sockets */ #define CAN_BCM 2 /* Broadcast Manager */ diff --git a/include/linux/if_ether.h b/include/linux/if_ether.h index 56d907a2c80..167ce5b363d 100644 --- a/include/linux/if_ether.h +++ b/include/linux/if_ether.h @@ -105,7 +105,8 @@ #define ETH_P_WAN_PPP 0x0007 /* Dummy type for WAN PPP frames*/ #define ETH_P_PPP_MP 0x0008 /* Dummy type for PPP MP frames */ #define ETH_P_LOCALTALK 0x0009 /* Localtalk pseudo type */ -#define ETH_P_CAN 0x000C /* Controller Area Network */ +#define ETH_P_CAN 0x000C /* CAN: Controller Area Network */ +#define ETH_P_CANFD 0x000D /* CANFD: CAN flexible data rate*/ #define ETH_P_PPPTALK 0x0010 /* Dummy type for Atalk over PPP*/ #define ETH_P_TR_802_2 0x0011 /* 802.2 frames */ #define ETH_P_MOBITEX 0x0015 /* Mobitex (kaz@cafe.net) */ diff --git a/net/can/af_can.c b/net/can/af_can.c index 6efcd37b4bd..c96140a1458 100644 --- a/net/can/af_can.c +++ b/net/can/af_can.c @@ -41,6 +41,7 @@ */ #include +#include #include #include #include @@ -824,6 +825,12 @@ static struct notifier_block can_netdev_notifier __read_mostly = { 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, can_dlc) != + offsetof(struct canfd_frame, len) || + offsetof(struct can_frame, data) != + offsetof(struct canfd_frame, data)); + printk(banner); memset(&can_rx_alldev_list, 0, sizeof(can_rx_alldev_list)); -- cgit v1.2.3-70-g09d2 From f057bbb6f9ed0fb61ea11105c9ef0ed5ac1a354d Mon Sep 17 00:00:00 2001 From: Rostislav Lisovy Date: Wed, 4 Jul 2012 05:32:03 +0200 Subject: net: em_canid: Ematch rule to match CAN frames according to their identifiers This ematch makes it possible to classify CAN frames (AF_CAN) according to their identifiers. This functionality can not be easily achieved with existing classifiers, such as u32, because CAN identifier is always stored in native endianness, whereas u32 expects Network byte order. Signed-off-by: Rostislav Lisovy Signed-off-by: Oliver Hartkopp Signed-off-by: Marc Kleine-Budde --- include/linux/can.h | 3 + include/linux/pkt_cls.h | 5 +- net/sched/Kconfig | 10 ++ net/sched/Makefile | 1 + net/sched/em_canid.c | 240 ++++++++++++++++++++++++++++++++++++++++++++++++ 5 files changed, 257 insertions(+), 2 deletions(-) create mode 100644 net/sched/em_canid.c (limited to 'include/linux/can.h') diff --git a/include/linux/can.h b/include/linux/can.h index 1a66cf6112a..018055efc03 100644 --- a/include/linux/can.h +++ b/include/linux/can.h @@ -38,6 +38,9 @@ */ typedef __u32 canid_t; +#define CAN_SFF_ID_BITS 11 +#define CAN_EFF_ID_BITS 29 + /* * Controller Area Network Error Message Frame Mask structure * diff --git a/include/linux/pkt_cls.h b/include/linux/pkt_cls.h index defbde203d0..38fbd4bc20a 100644 --- a/include/linux/pkt_cls.h +++ b/include/linux/pkt_cls.h @@ -451,8 +451,9 @@ enum { #define TCF_EM_U32 3 #define TCF_EM_META 4 #define TCF_EM_TEXT 5 -#define TCF_EM_VLAN 6 -#define TCF_EM_MAX 6 +#define TCF_EM_VLAN 6 +#define TCF_EM_CANID 7 +#define TCF_EM_MAX 7 enum { TCF_EM_PROG_TC diff --git a/net/sched/Kconfig b/net/sched/Kconfig index e7a8976bf25..4a5d2bd4f78 100644 --- a/net/sched/Kconfig +++ b/net/sched/Kconfig @@ -507,6 +507,16 @@ config NET_EMATCH_TEXT To compile this code as a module, choose M here: the module will be called em_text. +config NET_EMATCH_CANID + tristate "CAN Identifier" + depends on NET_EMATCH && CAN + ---help--- + Say Y here if you want to be able to classify CAN frames based + on CAN Identifier. + + To compile this code as a module, choose M here: the + module will be called em_canid. + config NET_CLS_ACT bool "Actions" ---help--- diff --git a/net/sched/Makefile b/net/sched/Makefile index 5940a1992f0..bcada751b4e 100644 --- a/net/sched/Makefile +++ b/net/sched/Makefile @@ -55,3 +55,4 @@ obj-$(CONFIG_NET_EMATCH_NBYTE) += em_nbyte.o obj-$(CONFIG_NET_EMATCH_U32) += em_u32.o obj-$(CONFIG_NET_EMATCH_META) += em_meta.o obj-$(CONFIG_NET_EMATCH_TEXT) += em_text.o +obj-$(CONFIG_NET_EMATCH_CANID) += em_canid.o diff --git a/net/sched/em_canid.c b/net/sched/em_canid.c new file mode 100644 index 00000000000..bfd34e4c1af --- /dev/null +++ b/net/sched/em_canid.c @@ -0,0 +1,240 @@ +/* + * em_canid.c Ematch rule to match CAN frames according to their CAN IDs + * + * This program is free software; you can distribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + * + * Idea: Oliver Hartkopp + * Copyright: (c) 2011 Czech Technical University in Prague + * (c) 2011 Volkswagen Group Research + * Authors: Michal Sojka + * Pavel Pisa + * Rostislav Lisovy + * Funded by: Volkswagen Group Research + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +#define EM_CAN_RULES_MAX 500 + +struct canid_match { + /* For each SFF CAN ID (11 bit) there is one record in this bitfield */ + DECLARE_BITMAP(match_sff, (1 << CAN_SFF_ID_BITS)); + + int rules_count; + int sff_rules_count; + int eff_rules_count; + + /* + * Raw rules copied from netlink message; Used for sending + * information to userspace (when 'tc filter show' is invoked) + * AND when matching EFF frames + */ + struct can_filter rules_raw[]; +}; + +/** + * em_canid_get_id() - Extracts Can ID out of the sk_buff structure. + */ +static canid_t em_canid_get_id(struct sk_buff *skb) +{ + /* CAN ID is stored within the data field */ + struct can_frame *cf = (struct can_frame *)skb->data; + + return cf->can_id; +} + +static void em_canid_sff_match_add(struct canid_match *cm, u32 can_id, + u32 can_mask) +{ + int i; + + /* + * Limit can_mask and can_id to SFF range to + * protect against write after end of array + */ + can_mask &= CAN_SFF_MASK; + can_id &= can_mask; + + /* Single frame */ + if (can_mask == CAN_SFF_MASK) { + set_bit(can_id, cm->match_sff); + return; + } + + /* All frames */ + if (can_mask == 0) { + bitmap_fill(cm->match_sff, (1 << CAN_SFF_ID_BITS)); + return; + } + + /* + * Individual frame filter. + * Add record (set bit to 1) for each ID that + * conforms particular rule + */ + for (i = 0; i < (1 << CAN_SFF_ID_BITS); i++) { + if ((i & can_mask) == can_id) + set_bit(i, cm->match_sff); + } +} + +static inline struct canid_match *em_canid_priv(struct tcf_ematch *m) +{ + return (struct canid_match *)m->data; +} + +static int em_canid_match(struct sk_buff *skb, struct tcf_ematch *m, + struct tcf_pkt_info *info) +{ + struct canid_match *cm = em_canid_priv(m); + canid_t can_id; + int match = 0; + int i; + const struct can_filter *lp; + + can_id = em_canid_get_id(skb); + + if (can_id & CAN_EFF_FLAG) { + for (i = 0, lp = cm->rules_raw; + i < cm->eff_rules_count; i++, lp++) { + if (!(((lp->can_id ^ can_id) & lp->can_mask))) { + match = 1; + break; + } + } + } else { /* SFF */ + can_id &= CAN_SFF_MASK; + match = (test_bit(can_id, cm->match_sff) ? 1 : 0); + } + + return match; +} + +static int em_canid_change(struct tcf_proto *tp, void *data, int len, + struct tcf_ematch *m) +{ + struct can_filter *conf = data; /* Array with rules */ + struct canid_match *cm; + struct canid_match *cm_old = (struct canid_match *)m->data; + int i; + + if (!len) + return -EINVAL; + + if (len % sizeof(struct can_filter)) + return -EINVAL; + + if (len > sizeof(struct can_filter) * EM_CAN_RULES_MAX) + return -EINVAL; + + cm = kzalloc(sizeof(struct canid_match) + len, GFP_KERNEL); + if (!cm) + return -ENOMEM; + + cm->rules_count = len / sizeof(struct can_filter); + + /* + * We need two for() loops for copying rules into two contiguous + * areas in rules_raw to process all eff rules with a simple loop. + * NB: The configuration interface supports sff and eff rules. + * We do not support filters here that match for the same can_id + * provided in a SFF and EFF frame (e.g. 0x123 / 0x80000123). + * For this (unusual case) two filters have to be specified. The + * SFF/EFF separation is done with the CAN_EFF_FLAG in the can_id. + */ + + /* Fill rules_raw with EFF rules first */ + for (i = 0; i < cm->rules_count; i++) { + if (conf[i].can_id & CAN_EFF_FLAG) { + memcpy(cm->rules_raw + cm->eff_rules_count, + &conf[i], + sizeof(struct can_filter)); + + cm->eff_rules_count++; + } + } + + /* append SFF frame rules */ + for (i = 0; i < cm->rules_count; i++) { + if (!(conf[i].can_id & CAN_EFF_FLAG)) { + memcpy(cm->rules_raw + + cm->eff_rules_count + + cm->sff_rules_count, + &conf[i], sizeof(struct can_filter)); + + cm->sff_rules_count++; + + em_canid_sff_match_add(cm, + conf[i].can_id, conf[i].can_mask); + } + } + + m->datalen = sizeof(struct canid_match) + len; + m->data = (unsigned long)cm; + + if (cm_old != NULL) { + pr_err("canid: Configuring an existing ematch!\n"); + kfree(cm_old); + } + + return 0; +} + +static void em_canid_destroy(struct tcf_proto *tp, struct tcf_ematch *m) +{ + struct canid_match *cm = em_canid_priv(m); + + kfree(cm); +} + +static int em_canid_dump(struct sk_buff *skb, struct tcf_ematch *m) +{ + struct canid_match *cm = em_canid_priv(m); + + /* + * When configuring this ematch 'rules_count' is set not to exceed + * 'rules_raw' array size + */ + if (nla_put_nohdr(skb, sizeof(struct can_filter) * cm->rules_count, + &cm->rules_raw) < 0) + return -EMSGSIZE; + + return 0; +} + +static struct tcf_ematch_ops em_canid_ops = { + .kind = TCF_EM_CANID, + .change = em_canid_change, + .match = em_canid_match, + .destroy = em_canid_destroy, + .dump = em_canid_dump, + .owner = THIS_MODULE, + .link = LIST_HEAD_INIT(em_canid_ops.link) +}; + +static int __init init_em_canid(void) +{ + return tcf_em_register(&em_canid_ops); +} + +static void __exit exit_em_canid(void) +{ + tcf_em_unregister(&em_canid_ops); +} + +MODULE_LICENSE("GPL"); + +module_init(init_em_canid); +module_exit(exit_em_canid); + +MODULE_ALIAS_TCF_EMATCH(TCF_EM_CANID); -- cgit v1.2.3-70-g09d2