diff options
| -rw-r--r-- | include/linux/can.h | 111 | ||||
| -rw-r--r-- | include/linux/can/core.h | 64 | ||||
| -rw-r--r-- | include/linux/can/error.h | 93 | ||||
| -rw-r--r-- | net/Kconfig | 1 | ||||
| -rw-r--r-- | net/Makefile | 1 | ||||
| -rw-r--r-- | net/can/Kconfig | 17 | ||||
| -rw-r--r-- | net/can/Makefile | 6 | ||||
| -rw-r--r-- | net/can/af_can.c | 861 | ||||
| -rw-r--r-- | net/can/af_can.h | 122 | ||||
| -rw-r--r-- | net/can/proc.c | 533 |
10 files changed, 1809 insertions, 0 deletions
diff --git a/include/linux/can.h b/include/linux/can.h new file mode 100644 index 00000000000..d18333302cb --- /dev/null +++ b/include/linux/can.h @@ -0,0 +1,111 @@ +/* + * linux/can.h + * + * Definitions for CAN network layer (socket addr / CAN frame / CAN filter) + * + * Authors: Oliver Hartkopp <oliver.hartkopp@volkswagen.de> + * Urs Thuermann <urs.thuermann@volkswagen.de> + * Copyright (c) 2002-2007 Volkswagen Group Electronic Research + * All rights reserved. + * + * Send feedback to <socketcan-users@lists.berlios.de> + * + */ + +#ifndef CAN_H +#define CAN_H + +#include <linux/types.h> +#include <linux/socket.h> + +/* controller area network (CAN) kernel definitions */ + +/* 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 */ + +/* valid bits in CAN ID for frame formats */ +#define CAN_SFF_MASK 0x000007FFU /* standard frame format (SFF) */ +#define CAN_EFF_MASK 0x1FFFFFFFU /* extended frame format (EFF) */ +#define CAN_ERR_MASK 0x1FFFFFFFU /* omit EFF, RTR, ERR flags */ + +/* + * 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 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 + * + * bit 0-28 : error class mask (see include/linux/can/error.h) + * bit 29-31 : set to zero + */ +typedef __u32 can_err_mask_t; + +/** + * 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. + */ +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))); +}; + +/* particular protocols of the protocol family PF_CAN */ +#define CAN_RAW 1 /* RAW sockets */ +#define CAN_BCM 2 /* Broadcast Manager */ +#define CAN_TP16 3 /* VAG Transport Protocol v1.6 */ +#define CAN_TP20 4 /* VAG Transport Protocol v2.0 */ +#define CAN_MCNET 5 /* Bosch MCNet */ +#define CAN_ISOTP 6 /* ISO 15765-2 Transport Protocol */ +#define CAN_NPROTO 7 + +#define SOL_CAN_BASE 100 + +/** + * struct sockaddr_can - the sockaddr structure for CAN sockets + * @can_family: address family number AF_CAN. + * @can_ifindex: CAN network interface index. + * @can_addr: protocol specific address information + */ +struct sockaddr_can { + sa_family_t can_family; + int can_ifindex; + union { + /* transport protocol class address information (e.g. ISOTP) */ + struct { canid_t rx_id, tx_id; } tp; + + /* reserved for future CAN protocols address information */ + } can_addr; +}; + +/** + * struct can_filter - CAN ID based filter in can_register(). + * @can_id: relevant bits of CAN ID which are not masked out. + * @can_mask: CAN mask (see description) + * + * Description: + * A filter matches, when + * + * <received_can_id> & 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). + */ +struct can_filter { + canid_t can_id; + canid_t can_mask; +}; + +#define CAN_INV_FILTER 0x20000000U /* to be set in can_filter.can_id */ + +#endif /* CAN_H */ diff --git a/include/linux/can/core.h b/include/linux/can/core.h new file mode 100644 index 00000000000..e9ca210ffa5 --- /dev/null +++ b/include/linux/can/core.h @@ -0,0 +1,64 @@ +/* + * linux/can/core.h + * + * Protoypes and definitions for CAN protocol modules using the PF_CAN core + * + * Authors: Oliver Hartkopp <oliver.hartkopp@volkswagen.de> + * Urs Thuermann <urs.thuermann@volkswagen.de> + * Copyright (c) 2002-2007 Volkswagen Group Electronic Research + * All rights reserved. + * + * Send feedback to <socketcan-users@lists.berlios.de> + * + */ + +#ifndef CAN_CORE_H +#define CAN_CORE_H + +#include <linux/can.h> +#include <linux/skbuff.h> +#include <linux/netdevice.h> + +#define CAN_VERSION "20071116" + +/* increment this number each time you change some user-space interface */ +#define CAN_ABI_VERSION "8" + +#define CAN_VERSION_STRING "rev " CAN_VERSION " abi " CAN_ABI_VERSION + +#define DNAME(dev) ((dev) ? (dev)->name : "any") + +/** + * struct can_proto - CAN protocol structure + * @type: type argument in socket() syscall, e.g. SOCK_DGRAM. + * @protocol: protocol number in socket() syscall. + * @capability: capability needed to open the socket, or -1 for no restriction. + * @ops: pointer to struct proto_ops for sock->ops. + * @prot: pointer to struct proto structure. + */ +struct can_proto { + int type; + int protocol; + int capability; + struct proto_ops *ops; + struct proto *prot; +}; + +/* function prototypes for the CAN networklayer core (af_can.c) */ + +extern int can_proto_register(struct can_proto *cp); +extern void can_proto_unregister(struct can_proto *cp); + +extern int can_rx_register(struct net_device *dev, canid_t can_id, + canid_t mask, + void (*func)(struct sk_buff *, void *), + void *data, char *ident); + +extern void can_rx_unregister(struct net_device *dev, canid_t can_id, + canid_t mask, + void (*func)(struct sk_buff *, void *), + void *data); + +extern int can_send(struct sk_buff *skb, int loop); + +#endif /* CAN_CORE_H */ diff --git a/include/linux/can/error.h b/include/linux/can/error.h new file mode 100644 index 00000000000..d4127fd9e68 --- /dev/null +++ b/include/linux/can/error.h @@ -0,0 +1,93 @@ +/* + * linux/can/error.h + * + * Definitions of the CAN error frame to be filtered and passed to the user. + * + * Author: Oliver Hartkopp <oliver.hartkopp@volkswagen.de> + * Copyright (c) 2002-2007 Volkswagen Group Electronic Research + * All rights reserved. + * + * Send feedback to <socketcan-users@lists.berlios.de> + * + */ + +#ifndef CAN_ERROR_H +#define CAN_ERROR_H + +#define CAN_ERR_DLC 8 /* dlc for error frames */ + +/* error class (mask) in can_id */ +#define CAN_ERR_TX_TIMEOUT 0x00000001U /* TX timeout (by netdevice driver) */ +#define CAN_ERR_LOSTARB 0x00000002U /* lost arbitration / data[0] */ +#define CAN_ERR_CRTL 0x00000004U /* controller problems / data[1] */ +#define CAN_ERR_PROT 0x00000008U /* protocol violations / data[2..3] */ +#define CAN_ERR_TRX 0x00000010U /* transceiver status / data[4] */ +#define CAN_ERR_ACK 0x00000020U /* received no ACK on transmission */ +#define CAN_ERR_BUSOFF 0x00000040U /* bus off */ +#define CAN_ERR_BUSERROR 0x00000080U /* bus error (may flood!) */ +#define CAN_ERR_RESTARTED 0x00000100U /* controller restarted */ + +/* arbitration lost in bit ... / data[0] */ +#define CAN_ERR_LOSTARB_UNSPEC 0x00 /* unspecified */ + /* else bit number in bitstream */ + +/* error status of CAN-controller / data[1] */ +#define CAN_ERR_CRTL_UNSPEC 0x00 /* unspecified */ +#define CAN_ERR_CRTL_RX_OVERFLOW 0x01 /* RX buffer overflow */ +#define CAN_ERR_CRTL_TX_OVERFLOW 0x02 /* TX buffer overflow */ +#define CAN_ERR_CRTL_RX_WARNING 0x04 /* reached warning level for RX errors */ +#define CAN_ERR_CRTL_TX_WARNING 0x08 /* reached warning level for TX errors */ +#define CAN_ERR_CRTL_RX_PASSIVE 0x10 /* reached error passive status RX */ +#define CAN_ERR_CRTL_TX_PASSIVE 0x20 /* reached error passive status TX */ + /* (at least one error counter exceeds */ + /* the protocol-defined level of 127) */ + +/* error in CAN protocol (type) / data[2] */ +#define CAN_ERR_PROT_UNSPEC 0x00 /* unspecified */ +#define CAN_ERR_PROT_BIT 0x01 /* single bit error */ +#define CAN_ERR_PROT_FORM 0x02 /* frame format error */ +#define CAN_ERR_PROT_STUFF 0x04 /* bit stuffing error */ +#define CAN_ERR_PROT_BIT0 0x08 /* unable to send dominant bit */ +#define CAN_ERR_PROT_BIT1 0x10 /* unable to send recessive bit */ +#define CAN_ERR_PROT_OVERLOAD 0x20 /* bus overload */ +#define CAN_ERR_PROT_ACTIVE 0x40 /* active error announcement */ +#define CAN_ERR_PROT_TX 0x80 /* error occured on transmission */ + +/* error in CAN protocol (location) / data[3] */ +#define CAN_ERR_PROT_LOC_UNSPEC 0x00 /* unspecified */ +#define CAN_ERR_PROT_LOC_SOF 0x03 /* start of frame */ +#define CAN_ERR_PROT_LOC_ID28_21 0x02 /* ID bits 28 - 21 (SFF: 10 - 3) */ +#define CAN_ERR_PROT_LOC_ID20_18 0x06 /* ID bits 20 - 18 (SFF: 2 - 0 )*/ +#define CAN_ERR_PROT_LOC_SRTR 0x04 /* substitute RTR (SFF: RTR) */ +#define CAN_ERR_PROT_LOC_IDE 0x05 /* identifier extension */ +#define CAN_ERR_PROT_LOC_ID17_13 0x07 /* ID bits 17-13 */ +#define CAN_ERR_PROT_LOC_ID12_05 0x0F /* ID bits 12-5 */ +#define CAN_ERR_PROT_LOC_ID04_00 0x0E /* ID bits 4-0 */ +#define CAN_ERR_PROT_LOC_RTR 0x0C /* RTR */ +#define CAN_ERR_PROT_LOC_RES1 0x0D /* reserved bit 1 */ +#define CAN_ERR_PROT_LOC_RES0 0x09 /* reserved bit 0 */ +#define CAN_ERR_PROT_LOC_DLC 0x0B /* data length code */ +#define CAN_ERR_PROT_LOC_DATA 0x0A /* data section */ +#define CAN_ERR_PROT_LOC_CRC_SEQ 0x08 /* CRC sequence */ +#define CAN_ERR_PROT_LOC_CRC_DEL 0x18 /* CRC delimiter */ +#define CAN_ERR_PROT_LOC_ACK 0x19 /* ACK slot */ +#define CAN_ERR_PROT_LOC_ACK_DEL 0x1B /* ACK delimiter */ +#define CAN_ERR_PROT_LOC_EOF 0x1A /* end of frame */ +#define CAN_ERR_PROT_LOC_INTERM 0x12 /* intermission */ + +/* error status of CAN-transceiver / data[4] */ +/* CANH CANL */ +#define CAN_ERR_TRX_UNSPEC 0x00 /* 0000 0000 */ +#define CAN_ERR_TRX_CANH_NO_WIRE 0x04 /* 0000 0100 */ +#define CAN_ERR_TRX_CANH_SHORT_TO_BAT 0x05 /* 0000 0101 */ +#define CAN_ERR_TRX_CANH_SHORT_TO_VCC 0x06 /* 0000 0110 */ +#define CAN_ERR_TRX_CANH_SHORT_TO_GND 0x07 /* 0000 0111 */ +#define CAN_ERR_TRX_CANL_NO_WIRE 0x40 /* 0100 0000 */ +#define CAN_ERR_TRX_CANL_SHORT_TO_BAT 0x50 /* 0101 0000 */ +#define CAN_ERR_TRX_CANL_SHORT_TO_VCC 0x60 /* 0110 0000 */ +#define CAN_ERR_TRX_CANL_SHORT_TO_GND 0x70 /* 0111 0000 */ +#define CAN_ERR_TRX_CANL_SHORT_TO_CANH 0x80 /* 1000 0000 */ + +/* controller specific additional information / data[5..7] */ + +#endif /* CAN_ERROR_H */ diff --git a/net/Kconfig b/net/Kconfig index ab4e6da5012..58ed2f4199d 100644 --- a/net/Kconfig +++ b/net/Kconfig @@ -218,6 +218,7 @@ endmenu endmenu source "net/ax25/Kconfig" +source "net/can/Kconfig" source "net/irda/Kconfig" source "net/bluetooth/Kconfig" source "net/rxrpc/Kconfig" diff --git a/net/Makefile b/net/Makefile index bbe7d2a4148..b7a13643b54 100644 --- a/net/Makefile +++ b/net/Makefile @@ -34,6 +34,7 @@ obj-$(CONFIG_LAPB) += lapb/ obj-$(CONFIG_NETROM) += netrom/ obj-$(CONFIG_ROSE) += rose/ obj-$(CONFIG_AX25) += ax25/ +obj-$(CONFIG_CAN) += can/ obj-$(CONFIG_IRDA) += irda/ obj-$(CONFIG_BT) += bluetooth/ obj-$(CONFIG_SUNRPC) += sunrpc/ diff --git a/net/can/Kconfig b/net/can/Kconfig new file mode 100644 index 00000000000..8b92790747e --- /dev/null +++ b/net/can/Kconfig @@ -0,0 +1,17 @@ +# +# Controller Area Network (CAN) network layer core configuration +# + +menuconfig CAN + depends on NET + tristate "CAN bus subsystem support" + ---help--- + Controller Area Network (CAN) is a slow (up to 1Mbit/s) serial + communications protocol which was developed by Bosch in + 1991, mainly for automotive, but now widely used in marine + (NMEA2000), industrial, and medical applications. + More information on the CAN network protocol family PF_CAN + is contained in <Documentation/networking/can.txt>. + + If you want CAN support you should say Y here and also to the + specific driver for your controller(s) below. diff --git a/net/can/Makefile b/net/can/Makefile new file mode 100644 index 00000000000..4c7563c2ccb --- /dev/null +++ b/net/can/Makefile @@ -0,0 +1,6 @@ +# +# Makefile for the Linux Controller Area Network core. +# + +obj-$(CONFIG_CAN) += can.o +can-objs := af_can.o proc.o diff --git a/net/can/af_can.c b/net/can/af_can.c new file mode 100644 index 00000000000..5158e886630 --- /dev/null +++ b/net/can/af_can.c @@ -0,0 +1,861 @@ +/* + * af_can.c - Protocol family CAN core module + * (used by different CAN protocol modules) + * + * Copyright (c) 2002-2007 Volkswagen Group Electronic Research + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of Volkswagen nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * Alternatively, provided that this notice is retained in full, this + * software may be distributed under the terms of the GNU General + * Public License ("GPL") version 2, in which case the provisions of the + * GPL apply INSTEAD OF those given above. + * + * The provided data structures and external interfaces from this code + * are not restricted to be used by modules with a GPL compatible license. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH + * DAMAGE. + * + * Send feedback to <socketcan-users@lists.berlios.de> + * + */ + +#include <linux/module.h> +#include <linux/init.h> +#include <linux/kmod.h> +#include <linux/slab.h> +#include <linux/list.h> +#include <linux/spinlock.h> +#include <linux/rcupdate.h> +#include <linux/uaccess.h> +#include <linux/net.h> +#include <linux/netdevice.h> +#include <linux/socket.h> +#include <linux/if_ether.h> +#include <linux/if_arp.h> +#include <linux/skbuff.h> +#include <linux/can.h> +#include <linux/can/core.h> +#include <net/net_namespace.h> +#include <net/sock.h> + +#include "af_can.h" + +static __initdata const char banner[] = KERN_INFO + "can: controller area network core (" CAN_VERSION_STRING ")\n"; + +MODULE_DESCRIPTION("Controller Area Network PF_CAN core"); +MODULE_LICENSE("Dual BSD/GPL"); +MODULE_AUTHOR("Urs Thuermann <urs.thuermann@volkswagen.de>, " + "Oliver Hartkopp <oliver.hartkopp@volkswagen.de>"); + +MODULE_ALIAS_NETPROTO(PF_CAN); + +static int stats_timer __read_mostly = 1; +module_param(stats_timer, int, S_IRUGO); +MODULE_PARM_DESC(stats_timer, "enable timer for statistics (default:on)"); + +HLIST_HEAD(can_rx_dev_list); +static struct dev_rcv_lists can_rx_alldev_list; +static DEFINE_SPINLOCK(can_rcvlists_lock); + +static struct kmem_cache *rcv_cache __read_mostly; + +/* table of registered CAN protocols */ +static struct can_proto *proto_tab[CAN_NPROTO] __read_mostly; +static DEFINE_SPINLOCK(proto_tab_lock); + +struct timer_list can_stattimer; /* timer for statistics update */ +struct s_stats can_stats; /* packet statistics */ +struct s_pstats can_pstats; /* receive list statistics */ + +/* + * af_can socket functions + */ + +static int can_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) +{ + struct sock *sk = sock->sk; + + switch (cmd) { + + case SIOCGSTAMP: + return sock_get_timestamp(sk, (struct timeval __user *)arg); + + default: + return -ENOIOCTLCMD; + } +} + +static void can_sock_destruct(struct sock *sk) +{ + skb_queue_purge(&sk->sk_receive_queue); +} + +static int can_create(struct net *net, struct socket *sock, int protocol) +{ + struct sock *sk; + struct can_proto *cp; + char module_name[sizeof("can-proto-000")]; + int err = 0; + + sock->state = SS_UNCONNECTED; + + if (protocol < 0 || protocol >= CAN_NPROTO) + return -EINVAL; + + if (net != &init_net) + return -EAFNOSUPPORT; + + /* try to load protocol module, when CONFIG_KMOD is defined */ + if (!proto_tab[protocol]) { + sprintf(module_name, "can-proto-%d", protocol); + err = request_module(module_name); + + /* + * In case of error we only print a message but don't + * return the error code immediately. Below we will + * return -EPROTONOSUPPORT + */ + if (err == -ENOSYS) { + if (printk_ratelimit()) + printk(KERN_INFO "can: request_module(%s)" + " not implemented.\n", module_name); + } else if (err) { + if (printk_ratelimit()) + printk(KERN_ERR "can: request_module(%s)" + " failed.\n", module_name); + } + } + + spin_lock(&proto_tab_lock); + cp = proto_tab[protocol]; + if (cp && !try_module_get(cp->prot->owner)) + cp = NULL; + spin_unlock(&proto_tab_lock); + + /* check for available protocol and correct usage */ + + if (!cp) + return -EPROTONOSUPPORT; + + if (cp->type != sock->type) { + err = -EPROTONOSUPPORT; + goto errout; + } + + if (cp->capability >= 0 && !capable(cp->capability)) { + err = -EPERM; + goto errout; + } + + sock->ops = cp->ops; + + sk = sk_alloc(net, PF_CAN, GFP_KERNEL, cp->prot); + if (!sk) { + err = -ENOMEM; + goto errout; + } + + sock_init_data(sock, sk); + sk->sk_destruct = can_sock_destruct; + + if (sk->sk_prot->init) + err = sk->sk_prot->init(sk); + + if (err) { + /* release sk on errors */ + sock_orphan(sk); + sock_put(sk); + } + + errout: + module_put(cp->prot->owner); + return err; +} + +/* + * af_can tx path + */ + +/** + * can_send - transmit a CAN frame (optional with local loopback) + * @skb: pointer to socket buffer with CAN frame in data section + * @loop: loopback for listeners on local CAN sockets (recommended default!) + * + * Return: + * 0 on success + * -ENETDOWN when the selected interface is down + * -ENOBUFS on full driver queue (see net_xmit_errno()) + * -ENOMEM when local loopback failed at calling skb_clone() + * -EPERM when trying to send on a non-CAN interface + */ +int can_send(struct sk_buff *skb, int loop) +{ + int err; + + if (skb->dev->type != ARPHRD_CAN) { + kfree_skb(skb); + return -EPERM; + } + + if (!(skb->dev->flags & IFF_UP)) { + kfree_skb(skb); + return -ENETDOWN; + } + + skb->protocol = htons(ETH_P_CAN); + skb_reset_network_header(skb); + skb_reset_transport_header(skb); + + if (loop) { + /* local loopback of sent CAN frames */ + + /* indication for the CAN driver: do loopback */ + skb->pkt_type = PACKET_LOOPBACK; + + /* + * The reference to the originating sock may be required + * by the receiving socket to check whether the frame is + * its own. Example: can_raw sockopt CAN_RAW_RECV_OWN_MSGS + * Therefore we have to ensure that skb->sk remains the + * reference to the originating sock by restoring skb->sk + * after each skb_clone() or skb_orphan() usage. + */ + + if (!(skb->dev->flags & IFF_ECHO)) { + /* + * If the interface is not capable to do loopback + * itself, we do it here. + */ + struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC); + + if (!newskb) { + kfree_skb(skb); + return -ENOMEM; + } + + newskb->sk = skb->sk; + newskb->ip_summed = CHECKSUM_UNNECESSARY; + newskb->pkt_type = PACKET_BROADCAST; + netif_rx(newskb); + } + } else { + /* indication for the CAN driver: no loopback required */ + skb->pkt_type = PACKET_HOST; + } + + /* send to netdevice */ + err = dev_queue_xmit(skb); + if (err > 0) + err = net_xmit_errno(err); + + /* update statistics */ + can_stats.tx_frames++; + can_stats.tx_frames_delta++; + + return err; +} +EXPORT_SYMBOL(can_send); + +/* + * af_can rx path + */ + +static struct dev_rcv_lists *find_dev_rcv_lists(struct net_device *dev) +{ + struct dev_rcv_lists *d = NULL; + struct hlist_node *n; + + /* + * find receive list for this device + * + * The hlist_for_each_entry*() macros curse through the list + * using the pointer variable n and set d to the containing + * struct in each list iteration. Therefore, after list + * iteration, d is unmodified when the list is empty, and it + * points to last list element, when the list is non-empty + * but no match in the loop body is found. I.e. d is *not* + * NULL when no match is found. We can, however, use the + * cursor variable n to decide if a match was found. + */ + + hlist_for_each_entry_rcu(d, n, &can_rx_dev_list, list) { + if (d->dev == dev) + break; + } + + return n ? d : NULL; +} + +static struct hlist_head *find_rcv_list(canid_t *can_id, canid_t *mask, + struct dev_rcv_lists *d) +{ + canid_t inv = *can_id & CAN_INV_FILTER; /* save flag before masking */ + + /* filter error frames */ + if (*mask & CAN_ERR_FLAG) { + /* clear CAN_ERR_FLAG in list entry */ + *mask &= CAN_ERR_MASK; + return &d->rx[RX_ERR]; + } + + /* ensure valid values in can_mask */ + if (*mask & CAN_EFF_FLAG) + *mask &= (CAN_EFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG); + else + *mask &= (CAN_SFF_MASK | CAN_RTR_FLAG); + + /* reduce condition testing at receive time */ + *can_id &= *mask; + + /* inverse can_id/can_mask filter */ + if (inv) + return &d->rx[RX_INV]; + + /* mask == 0 => no condition testing at receive time */ + if (!(*mask)) + return &d->rx[RX_ALL]; + + /* use extra filterset for the subscription of exactly *ONE* can_id */ + if (*can_id & CAN_EFF_FLAG) { + if (*mask == (CAN_EFF_MASK | CAN_EFF_FLAG)) { + /* RFC: a use-case for hash-tables in the future? */ + return &d->rx[RX_EFF]; + } + } else { + if (*mask == CAN_SFF_MASK) + return &d->rx_sff[*can_id]; + } + + /* default: filter via can_id/can_mask */ + return &d->rx[RX_FIL]; +} + +/** + * can_rx_register - subscribe CAN frames from a specific interface + * @dev: pointer to netdevice (NULL => subcribe from 'all' CAN devices list) + * @can_id: CAN identifier (see description) + * @mask: CAN mask (see description) + * @func: callback function on filter match + * @data: returned parameter for callback function + * @ident: string for calling module indentification + * + * Description: + * Invokes the callback function with the received sk_buff and the given + * parameter 'data' on a matching receive filter. A filter matches, when + * + * <received_can_id> & 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). + * + * Return: + * 0 on success + * -ENOMEM on missing cache mem to create subscription entry + * -ENODEV unknown device + */ +int can_rx_register(struct net_device *dev, canid_t can_id, canid_t mask, + void (*func)(struct sk_buff *, void *), void *data, + char *ident) +{ + struct receiver *r; + struct hlist_head *rl; + struct dev_rcv_lists *d; + int err = 0; + + /* insert new receiver (dev,canid,mask) -> (func,data) */ + + r = kmem_cache_alloc(rcv_cache, GFP_KERNEL); + if (!r) + return -ENOMEM; + + spin_lock(&can_rcvlists_lock); + + d = find_dev_rcv_lists(dev); + if (d) { + rl = find_rcv_list(&can_id, &mask, d); + + r->can_id = can_id; + r->mask = mask; + r->matches = 0; + r->func = func; + r->data = data; + r->ident = ident; + + hlist_add_head_rcu(&r->list, rl); + d->entries++; + + can_pstats.rcv_entries++; + if (can_pstats.rcv_entries_max < can_pstats.rcv_entries) + can_pstats.rcv_entries_max = can_pstats.rcv_entries; + } else { + kmem_cache_free(rcv_cache, r); + err = -ENODEV; + } + + spin_unlock(&can_rcvlists_lock); + + return err; +} +EXPORT_SYMBOL(can_rx_register); + +/* + * can_rx_delete_device - rcu callback for dev_rcv_lists structure removal + */ +static void can_rx_delete_device(struct rcu_head *rp) +{ + struct dev_rcv_lists *d = container_of(rp, struct dev_rcv_lists, rcu); + + kfree(d); +} + +/* + * can_rx_delete_receiver - rcu callback for single receiver entry removal + */ +static void can_rx_delete_receiver(struct rcu_head *rp) +{ + struct receiver *r = container_of(rp, struct receiver, rcu); + + kmem_cache_free(rcv_cache, r); +} + +/** + * can_rx_unregister - unsubscribe CAN frames from a specific interface + * @dev: pointer to netdevice (NULL => unsubcribe from 'all' CAN devices list) + * @can_id: CAN identifier + * @mask: CAN mask + * @func: callback function on filter match + * @data: returned parameter for callback function + * + * Description: + * Removes subscription entry depending on given (subscription) values. + */ +void can_rx_unregister(struct net_device *dev, canid_t can_id, canid_t mask, + void (*func)(struct sk_buff *, void *), void *data) +{ + struct receiver *r = NULL; + struct hlist_head *rl; + struct hlist_node *next; + struct dev_rcv_lists *d; + + spin_lock(&can_rcvlists_lock); + + d = find_dev_rcv_lists(dev); + if (!d) { + printk(KERN_ERR "BUG: receive list not found for " + "dev %s, id %03X, mask %03X\n", + DNAME(dev), can_id, mask); + goto out; + } + + rl = find_rcv_list(&can_id, &mask, d); + + /* + * Search the receiver list for the item to delete. This should + * exist, since no receiver may be unregistered that hasn't + * been registered before. + */ + + hlist_for_each_entry_rcu(r, next, rl, list) { + if (r->can_id == can_id && r->mask == mask + && r->func == func && r->data == data) + break; + } + + /* + * Check for bugs in CAN protocol implementations: + * If no matching list item was found, the list cursor variable next + * will be NULL, while r will point to the last item of the list. + */ + + if (!next) { + printk(KERN_ERR "BUG: receive list entry not found for " + "dev %s, id %03X, mask %03X\n", + DNAME(dev), can_id, mask); + r = NULL; + d = NULL; + goto out; + } + + hlist_del_rcu(&r->list); + d->entries--; + + if (can_pstats.rcv_entries > 0) + can_pstats.rcv_entries--; + + /* remove device structure requested by NETDEV_UNREGISTER */ + if (d->remove_on_zero_entries && !d->entries) + hlist_del_rcu(&d->list); + else + d = NULL; + + out: + spin_unlock(&can_rcvlists_lock); + + /* schedule the receiver item for deletion */ + if (r) + call_rcu(&r->rcu, can_rx_delete_receiver); + + /* schedule the device structure for deletion */ + if (d) + call_rcu(&d->rcu, can_rx_delete_device); +} +EXPORT_SYMBOL(can_rx_unregister); + +static inline void deliver(struct sk_buff *skb, struct receiver *r) +{ + struct sk_buff *clone = skb_clone(skb, GFP_ATOMIC); + + if (clone) { + clone->sk = skb->sk; + r->func(clone, r->data); + r->matches++; + } +} + +static int can_rcv_filter(struct dev_rcv_lists *d, struct sk_buff *skb) +{ + struct receiver *r; + struct hlist_node *n; + int matches = 0; + struct can_frame *cf = (struct can_frame *)skb->data; + canid_t can_id = cf->can_id; + + if (d->entries == 0) + return 0; + + if (can_id & CAN_ERR_FLAG) { + /* check for error frame entries only */ + hlist_for_each_entry_rcu(r, n, &d->rx[RX_ERR], list) { + if (can_id & r->mask) { + deliver(skb, r); + matches++; + } + } + return matches; + } + + /* check for unfiltered entries */ + hlist_for_each_entry_rcu(r, n, &d->rx[RX_ALL], list) { + deliver(skb, r); + matches++; + } + + /* check for can_id/mask entries */ + hlist_for_each_entry_rcu(r, n, &d->rx[RX_FIL], list) { + if ((can_id & r->mask) == r->can_id) { + deliver(skb, r); + matches++; + } + } + + /* check for inverted can_id/mask entries */ + hlist_for_each_entry_rcu(r, n, &d->rx[RX_INV], list) { + if ((can_id & r->mask) != r->can_id) { + deliver(skb, r); + matches++; + } + } + + /* check CAN_ID specific entries */ + if (can_id & CAN_EFF_FLAG) { + hlist_for_each_entry_rcu(r, n, &d->rx[RX_EFF], list) { + if (r->can_id == can_id) { + deliver(skb, r); + matches++; + } + } + } else { + can_id &= CAN_SFF_MASK; + hlist_for_each_entry_rcu(r, n, &d->rx_sff[can_id], list) { + deliver(skb, r); + matches++; + } + } + + return matches; +} + +static int can_rcv(struct sk_buff *skb, struct net_device *dev, + struct packet_type *pt, struct net_device *orig_dev) +{ + struct dev_rcv_lists *d; + int matches; + + if (dev->type != ARPHRD_CAN || dev->nd_net != &init_net) { + kfree_skb(skb); + return 0; + } + + /* update statistics */ + can_stats.rx_frames++; + can_stats.rx_frames_delta++; + + rcu_read_lock(); + + /* deliver the packet to sockets listening on all devices */ + matches = can_rcv_filter(&can_rx_alldev_list, skb); + + /* find receive list for this device */ + d = find_dev_rcv_lists(dev); + if (d) + matches += can_rcv_filter(d, skb); + + rcu_read_unlock(); + + /* free the skbuff allocated by the netdevice driver */ + kfree_skb(skb); + + if (matches > 0) { + can_stats.matches++; + can_stats.matches_delta++; + } + + return 0; +} + +/* + * af_can protocol functions + */ + +/** + * can_proto_register - register CAN transport protocol + * @cp: pointer to CAN protocol structure + * + * Return: + * 0 on success + * -EINVAL invalid (out of range) protocol number + * -EBUSY protocol already in use + * -ENOBUF if proto_register() fails + */ +int can_proto_register(struct can_proto *cp) +{ + int proto = cp->protocol; + int err = 0; + + if (proto < 0 || proto >= CAN_NPROTO) { + printk(KERN_ERR "can: protocol number %d out of range\n", + proto); + return -EINVAL; + } + + spin_lock(&proto_tab_lock); + if (proto_tab[proto]) { + printk(KERN_ERR "can: protocol %d already registered\n", + proto); + err = -EBUSY; + goto errout; + } + + err = proto_register(cp->prot, 0); + if (err < 0) + goto errout; + + proto_tab[proto] = cp; + + /* use generic ioctl function if the module doesn't bring its own */ + if (!cp->ops->ioctl) + cp->ops->ioctl = can_ioctl; + + errout: + spin_unlock(&proto_tab_lock); + + return err; +} +EXPORT_SYMBOL(can_proto_register); + +/** + * can_proto_unregister - unregister CAN transport protocol + * @cp: pointer to CAN protocol structure + */ +void can_proto_unregister(struct can_proto *cp) +{ + int proto = cp->protocol; + + spin_lock(&proto_tab_lock); + if (!proto_tab[proto]) { + printk(KERN_ERR "BUG: can: protocol %d is not registered\n", + proto); + } + proto_unregister(cp->prot); + proto_tab[proto] = NULL; + spin_unlock(&proto_tab_lock); +} +EXPORT_SYMBOL(can_proto_unregister); + +/* + * af_can notifier to create/remove CAN netdevice specific structs + */ +static int can_notifier(struct notifier_block *nb, unsigned long msg, + void *data) +{ + struct net_device *dev = (struct net_device *)data; + struct dev_rcv_lists *d; + + if (dev->nd_net != &init_net) + return NOTIFY_DONE; + + if (dev->type != ARPHRD_CAN) + return NOTIFY_DONE; + + switch (msg) { + + case NETDEV_REGISTER: + + /* + * create new dev_rcv_lists for this device + * + * N.B. zeroing the struct is the correct initialization + * for the embedded hlist_head structs. + * Another list type, e.g. list_head, would require + * explicit initialization. + */ + + d = kzalloc(sizeof(*d), GFP_KERNEL); + if (!d) { + printk(KERN_ERR + "can: allocation of receive list failed\n"); + return NOTIFY_DONE; + } + d->dev = dev; |