[CAN]: Add PF_CAN core module
Oliver Hartkopp [Fri, 16 Nov 2007 23:52:17 +0000 (15:52 -0800)]
This patch adds the CAN core functionality but no protocols or drivers.
No protocol implementations are included here.  They come as separate
patches.  Protocol numbers are already in include/linux/can.h.

Signed-off-by: Oliver Hartkopp <oliver.hartkopp@volkswagen.de>
Signed-off-by: Urs Thuermann <urs.thuermann@volkswagen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/can.h [new file with mode: 0644]
include/linux/can/core.h [new file with mode: 0644]
include/linux/can/error.h [new file with mode: 0644]
net/Kconfig
net/Makefile
net/can/Kconfig [new file with mode: 0644]
net/can/Makefile [new file with mode: 0644]
net/can/af_can.c [new file with mode: 0644]
net/can/af_can.h [new file with mode: 0644]
net/can/proc.c [new file with mode: 0644]

diff --git a/include/linux/can.h b/include/linux/can.h
new file mode 100644 (file)
index 0000000..d183333
--- /dev/null
@@ -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 (file)
index 0000000..e9ca210
--- /dev/null
@@ -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 (file)
index 0000000..d4127fd
--- /dev/null
@@ -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 */
index ab4e6da..58ed2f4 100644 (file)
@@ -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"
index bbe7d2a..b7a1364 100644 (file)
@@ -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 (file)
index 0000000..8b92790
--- /dev/null
@@ -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 (file)
index 0000000..4c7563c
--- /dev/null
@@ -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 (file)
index 0000000..5158e88
--- /dev/null
@@ -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;
+
+               spin_lock(&can_rcvlists_lock);
+               hlist_add_head_rcu(&d->list, &can_rx_dev_list);
+               spin_unlock(&can_rcvlists_lock);
+
+               break;
+
+       case NETDEV_UNREGISTER:
+               spin_lock(&can_rcvlists_lock);
+
+               d = find_dev_rcv_lists(dev);
+               if (d) {
+                       if (d->entries) {
+                               d->remove_on_zero_entries = 1;
+                               d = NULL;
+                       } else
+                               hlist_del_rcu(&d->list);
+               } else
+                       printk(KERN_ERR "can: notifier: receive list not "
+                              "found for dev %s\n", dev->name);
+
+               spin_unlock(&can_rcvlists_lock);
+
+               if (d)
+                       call_rcu(&d->rcu, can_rx_delete_device);
+
+               break;
+       }
+
+       return NOTIFY_DONE;
+}
+
+/*
+ * af_can module init/exit functions
+ */
+
+static struct packet_type can_packet __read_mostly = {
+       .type = __constant_htons(ETH_P_CAN),
+       .dev  = NULL,
+       .func = can_rcv,
+};
+
+static struct net_proto_family can_family_ops __read_mostly = {
+       .family = PF_CAN,
+       .create = can_create,
+       .owner  = THIS_MODULE,
+};
+
+/* notifier block for netdevice event */
+static struct notifier_block can_netdev_notifier __read_mostly = {
+       .notifier_call = can_notifier,
+};
+
+static __init int can_init(void)
+{
+       printk(banner);
+
+       rcv_cache = kmem_cache_create("can_receiver", sizeof(struct receiver),
+                                     0, 0, NULL);
+       if (!rcv_cache)
+               return -ENOMEM;
+
+       /*
+        * Insert can_rx_alldev_list for reception on all devices.
+        * This struct is zero initialized which is correct for the
+        * embedded hlist heads, the dev pointer, and the entries counter.
+        */
+
+       spin_lock(&can_rcvlists_lock);
+       hlist_add_head_rcu(&can_rx_alldev_list.list, &can_rx_dev_list);
+       spin_unlock(&can_rcvlists_lock);
+
+       if (stats_timer) {
+               /* the statistics are updated every second (timer triggered) */
+               setup_timer(&can_stattimer, can_stat_update, 0);
+               mod_timer(&can_stattimer, round_jiffies(jiffies + HZ));
+       } else
+               can_stattimer.function = NULL;
+
+       can_init_proc();
+
+       /* protocol register */
+       sock_register(&can_family_ops);
+       register_netdevice_notifier(&can_netdev_notifier);
+       dev_add_pack(&can_packet);
+
+       return 0;
+}
+
+static __exit void can_exit(void)
+{
+       struct dev_rcv_lists *d;
+       struct hlist_node *n, *next;
+
+       if (stats_timer)
+               del_timer(&can_stattimer);
+
+       can_remove_proc();
+
+       /* protocol unregister */
+       dev_remove_pack(&can_packet);
+       unregister_netdevice_notifier(&can_netdev_notifier);
+       sock_unregister(PF_CAN);
+
+       /* remove can_rx_dev_list */
+       spin_lock(&can_rcvlists_lock);
+       hlist_del(&can_rx_alldev_list.list);
+       hlist_for_each_entry_safe(d, n, next, &can_rx_dev_list, list) {
+               hlist_del(&d->list);
+               kfree(d);
+       }
+       spin_unlock(&can_rcvlists_lock);
+
+       kmem_cache_destroy(rcv_cache);
+}
+
+module_init(can_init);
+module_exit(can_exit);
diff --git a/net/can/af_can.h b/net/can/af_can.h
new file mode 100644 (file)
index 0000000..18f91e3
--- /dev/null
@@ -0,0 +1,122 @@
+/*
+ * 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>
+ *
+ */
+
+#ifndef AF_CAN_H
+#define AF_CAN_H
+
+#include <linux/skbuff.h>
+#include <linux/netdevice.h>
+#include <linux/list.h>
+#include <linux/rcupdate.h>
+#include <linux/can.h>
+
+/* af_can rx dispatcher structures */
+
+struct receiver {
+       struct hlist_node list;
+       struct rcu_head rcu;
+       canid_t can_id;
+       canid_t mask;
+       unsigned long matches;
+       void (*func)(struct sk_buff *, void *);
+       void *data;
+       char *ident;
+};
+
+enum { RX_ERR, RX_ALL, RX_FIL, RX_INV, RX_EFF, RX_MAX };
+
+struct dev_rcv_lists {
+       struct hlist_node list;
+       struct rcu_head rcu;
+       struct net_device *dev;
+       struct hlist_head rx[RX_MAX];
+       struct hlist_head rx_sff[0x800];
+       int remove_on_zero_entries;
+       int entries;
+};
+
+/* statistic structures */
+
+/* can be reset e.g. by can_init_stats() */
+struct s_stats {
+       unsigned long jiffies_init;
+
+       unsigned long rx_frames;
+       unsigned long tx_frames;
+       unsigned long matches;
+
+       unsigned long total_rx_rate;
+       unsigned long total_tx_rate;
+       unsigned long total_rx_match_ratio;
+
+       unsigned long current_rx_rate;
+       unsigned long current_tx_rate;
+       unsigned long current_rx_match_ratio;
+
+       unsigned long max_rx_rate;
+       unsigned long max_tx_rate;
+       unsigned long max_rx_match_ratio;
+
+       unsigned long rx_frames_delta;
+       unsigned long tx_frames_delta;
+       unsigned long matches_delta;
+};
+
+/* persistent statistics */
+struct s_pstats {
+       unsigned long stats_reset;
+       unsigned long user_reset;
+       unsigned long rcv_entries;
+       unsigned long rcv_entries_max;
+};
+
+/* function prototypes for the CAN networklayer procfs (proc.c) */
+extern void can_init_proc(void);
+extern void can_remove_proc(void);
+extern void can_stat_update(unsigned long data);
+
+/* structures and variables from af_can.c needed in proc.c for reading */
+extern struct timer_list can_stattimer;    /* timer for statistics update */
+extern struct s_stats    can_stats;        /* packet statistics */
+extern struct s_pstats   can_pstats;       /* receive list statistics */
+extern struct hlist_head can_rx_dev_list;  /* rx dispatcher structures */
+
+#endif /* AF_CAN_H */
diff --git a/net/can/proc.c b/net/can/proc.c
new file mode 100644 (file)
index 0000000..520fef5
--- /dev/null
@@ -0,0 +1,533 @@
+/*
+ * proc.c - procfs support for Protocol family CAN core module
+ *
+ * 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/proc_fs.h>
+#include <linux/list.h>
+#include <linux/rcupdate.h>
+#include <linux/can/core.h>
+
+#include "af_can.h"
+
+/*
+ * proc filenames for the PF_CAN core
+ */
+
+#define CAN_PROC_VERSION     "version"
+#define CAN_PROC_STATS       "stats"
+#define CAN_PROC_RESET_STATS "reset_stats"
+#define CAN_PROC_RCVLIST_ALL "rcvlist_all"
+#define CAN_PROC_RCVLIST_FIL "rcvlist_fil"
+#define CAN_PROC_RCVLIST_INV "rcvlist_inv"
+#define CAN_PROC_RCVLIST_SFF "rcvlist_sff"
+#define CAN_PROC_RCVLIST_EFF "rcvlist_eff"
+#define CAN_PROC_RCVLIST_ERR "rcvlist_err"
+
+static struct proc_dir_entry *can_dir;
+static struct proc_dir_entry *pde_version;
+static struct proc_dir_entry *pde_stats;
+static struct proc_dir_entry *pde_reset_stats;
+static struct proc_dir_entry *pde_rcvlist_all;
+static struct proc_dir_entry *pde_rcvlist_fil;
+static struct proc_dir_entry *pde_rcvlist_inv;
+static struct proc_dir_entry *pde_rcvlist_sff;
+static struct proc_dir_entry *pde_rcvlist_eff;
+static struct proc_dir_entry *pde_rcvlist_err;
+
+static int user_reset;
+
+static const char rx_list_name[][8] = {
+       [RX_ERR] = "rx_err",
+       [RX_ALL] = "rx_all",
+       [RX_FIL] = "rx_fil",
+       [RX_INV] = "rx_inv",
+       [RX_EFF] = "rx_eff",
+};
+
+/*
+ * af_can statistics stuff
+ */
+
+static void can_init_stats(void)
+{
+       /*
+        * This memset function is called from a timer context (when
+        * can_stattimer is active which is the default) OR in a process
+        * context (reading the proc_fs when can_stattimer is disabled).
+        */
+       memset(&can_stats, 0, sizeof(can_stats));
+       can_stats.jiffies_init = jiffies;
+
+       can_pstats.stats_reset++;
+
+       if (user_reset) {
+               user_reset = 0;
+               can_pstats.user_reset++;
+       }
+}
+
+static unsigned long calc_rate(unsigned long oldjif, unsigned long newjif,
+                              unsigned long count)
+{
+       unsigned long rate;
+
+       if (oldjif == newjif)
+               return 0;
+
+       /* see can_stat_update() - this should NEVER happen! */
+       if (count > (ULONG_MAX / HZ)) {
+               printk(KERN_ERR "can: calc_rate: count exceeded! %ld\n",
+                      count);
+               return 99999999;
+       }
+
+       rate = (count * HZ) / (newjif - oldjif);
+
+       return rate;
+}
+
+void can_stat_update(unsigned long data)
+{
+       unsigned long j = jiffies; /* snapshot */
+
+       /* restart counting in timer context on user request */
+       if (user_reset)
+               can_init_stats();
+
+       /* restart counting on jiffies overflow */
+       if (j < can_stats.jiffies_init)
+               can_init_stats();
+
+       /* prevent overflow in calc_rate() */
+       if (can_stats.rx_frames > (ULONG_MAX / HZ))
+               can_init_stats();
+
+       /* prevent overflow in calc_rate() */
+       if (can_stats.tx_frames > (ULONG_MAX / HZ))
+               can_init_stats();
+
+       /* matches overflow - very improbable */
+       if (can_stats.matches > (ULONG_MAX / 100))
+               can_init_stats();
+
+       /* calc total values */
+       if (can_stats.rx_frames)
+               can_stats.total_rx_match_ratio = (can_stats.matches * 100) /
+                       can_stats.rx_frames;
+
+       can_stats.total_tx_rate = calc_rate(can_stats.jiffies_init, j,
+                                           can_stats.tx_frames);
+       can_stats.total_rx_rate = calc_rate(can_stats.jiffies_init, j,
+                                           can_stats.rx_frames);
+
+       /* calc current values */
+       if (can_stats.rx_frames_delta)
+               can_stats.current_rx_match_ratio =
+                       (can_stats.matches_delta * 100) /
+                       can_stats.rx_frames_delta;
+
+       can_stats.current_tx_rate = calc_rate(0, HZ, can_stats.tx_frames_delta);
+       can_stats.current_rx_rate = calc_rate(0, HZ, can_stats.rx_frames_delta);
+
+       /* check / update maximum values */
+       if (can_stats.max_tx_rate < can_stats.current_tx_rate)
+               can_stats.max_tx_rate = can_stats.current_tx_rate;
+
+       if (can_stats.max_rx_rate < can_stats.current_rx_rate)
+               can_stats.max_rx_rate = can_stats.current_rx_rate;
+
+       if (can_stats.max_rx_match_ratio < can_stats.current_rx_match_ratio)
+               can_stats.max_rx_match_ratio = can_stats.current_rx_match_ratio;
+
+       /* clear values for 'current rate' calculation */
+       can_stats.tx_frames_delta = 0;
+       can_stats.rx_frames_delta = 0;
+       can_stats.matches_delta   = 0;
+
+       /* restart timer (one second) */
+       mod_timer(&can_stattimer, round_jiffies(jiffies + HZ));
+}
+
+/*
+ * proc read functions
+ *
+ * From known use-cases we expect about 10 entries in a receive list to be
+ * printed in the proc_fs. So PAGE_SIZE is definitely enough space here.
+ *
+ */
+
+static int can_print_rcvlist(char *page, int len, struct hlist_head *rx_list,
+                            struct net_device *dev)
+{
+       struct receiver *r;
+       struct hlist_node *n;
+
+       rcu_read_lock();
+       hlist_for_each_entry_rcu(r, n, rx_list, list) {
+               char *fmt = (r->can_id & CAN_EFF_FLAG)?
+                       "   %-5s  %08X  %08x  %08x  %08x  %8ld  %s\n" :
+                       "   %-5s     %03X    %08x  %08lx  %08lx  %8ld  %s\n";
+
+               len += snprintf(page + len, PAGE_SIZE - len, fmt,
+                               DNAME(dev), r->can_id, r->mask,
+                               (unsigned long)r->func, (unsigned long)r->data,
+                               r->matches, r->ident);
+
+               /* does a typical line fit into the current buffer? */
+
+               /* 100 Bytes before end of buffer */
+               if (len > PAGE_SIZE - 100) {
+                       /* mark output cut off */
+                       len += snprintf(page + len, PAGE_SIZE - len,
+                                       "   (..)\n");
+                       break;
+               }
+       }
+       rcu_read_unlock();
+
+       return len;
+}
+
+static int can_print_recv_banner(char *page, int len)
+{
+       /*
+        *                  can1.  00000000  00000000  00000000
+        *                 .......          0  tp20
+        */
+       len += snprintf(page + len, PAGE_SIZE - len,
+                       "  device   can_id   can_mask  function"
+                       "  userdata   matches  ident\n");
+
+       return len;
+}
+
+static int can_proc_read_stats(char *page, char **start, off_t off,
+                              int count, int *eof, void *data)
+{
+       int len = 0;
+
+       len += snprintf(page + len, PAGE_SIZE - len, "\n");
+       len += snprintf(page + len, PAGE_SIZE - len,
+                       " %8ld transmitted frames (TXF)\n",
+                       can_stats.tx_frames);
+       len += snprintf(page + len, PAGE_SIZE - len,
+                       " %8ld received frames (RXF)\n", can_stats.rx_frames);
+       len += snprintf(page + len, PAGE_SIZE - len,
+                       " %8ld matched frames (RXMF)\n", can_stats.matches);
+
+       len += snprintf(page + len, PAGE_SIZE - len, "\n");
+
+       if (can_stattimer.function == can_stat_update) {
+               len += snprintf(page + len, PAGE_SIZE - len,
+                               " %8ld %% total match ratio (RXMR)\n",
+                               can_stats.total_rx_match_ratio);
+
+               len += snprintf(page + len, PAGE_SIZE - len,
+                               " %8ld frames/s total tx rate (TXR)\n",
+                               can_stats.total_tx_rate);
+               len += snprintf(page + len, PAGE_SIZE - len,
+                               " %8ld frames/s total rx rate (RXR)\n",
+                               can_stats.total_rx_rate);
+
+               len += snprintf(page + len, PAGE_SIZE - len, "\n");
+
+               len += snprintf(page + len, PAGE_SIZE - len,
+                               " %8ld %% current match ratio (CRXMR)\n",
+                               can_stats.current_rx_match_ratio);
+
+               len += snprintf(page + len, PAGE_SIZE - len,
+                               " %8ld frames/s current tx rate (CTXR)\n",
+                               can_stats.current_tx_rate);
+               len += snprintf(page + len, PAGE_SIZE - len,
+                               " %8ld frames/s current rx rate (CRXR)\n",
+                               can_stats.current_rx_rate);
+
+               len += snprintf(page + len, PAGE_SIZE - len, "\n");
+
+               len += snprintf(page + len, PAGE_SIZE - len,
+                               " %8ld %% max match ratio (MRXMR)\n",
+                               can_stats.max_rx_match_ratio);
+
+               len += snprintf(page + len, PAGE_SIZE - len,
+                               " %8ld frames/s max tx rate (MTXR)\n",
+                               can_stats.max_tx_rate);
+               len += snprintf(page + len, PAGE_SIZE - len,
+                               " %8ld frames/s max rx rate (MRXR)\n",
+                               can_stats.max_rx_rate);
+
+               len += snprintf(page + len, PAGE_SIZE - len, "\n");
+       }
+
+       len += snprintf(page + len, PAGE_SIZE - len,
+                       " %8ld current receive list entries (CRCV)\n",
+                       can_pstats.rcv_entries);
+       len += snprintf(page + len, PAGE_SIZE - len,
+                       " %8ld maximum receive list entries (MRCV)\n",
+                       can_pstats.rcv_entries_max);
+
+       if (can_pstats.stats_reset)
+               len += snprintf(page + len, PAGE_SIZE - len,
+                               "\n %8ld statistic resets (STR)\n",
+                               can_pstats.stats_reset);
+
+       if (can_pstats.user_reset)
+               len += snprintf(page + len, PAGE_SIZE - len,
+                               " %8ld user statistic resets (USTR)\n",
+                               can_pstats.user_reset);
+
+       len += snprintf(page + len, PAGE_SIZE - len, "\n");
+
+       *eof = 1;
+       return len;
+}
+
+static int can_proc_read_reset_stats(char *page, char **start, off_t off,
+                                    int count, int *eof, void *data)
+{
+       int len = 0;
+
+       user_reset = 1;
+
+       if (can_stattimer.function == can_stat_update) {
+               len += snprintf(page + len, PAGE_SIZE - len,
+                               "Scheduled statistic reset #%ld.\n",
+                               can_pstats.stats_reset + 1);
+
+       } else {
+               if (can_stats.jiffies_init != jiffies)
+                       can_init_stats();
+
+               len += snprintf(page + len, PAGE_SIZE - len,
+                               "Performed statistic reset #%ld.\n",
+                               can_pstats.stats_reset);
+       }
+
+       *eof = 1;
+       return len;
+}
+
+static int can_proc_read_version(char *page, char **start, off_t off,
+                                int count, int *eof, void *data)
+{
+       int len = 0;
+
+       len += snprintf(page + len, PAGE_SIZE - len, "%s\n",
+                       CAN_VERSION_STRING);
+       *eof = 1;
+       return len;
+}
+
+static int can_proc_read_rcvlist(char *page, char **start, off_t off,
+                                int count, int *eof, void *data)
+{
+       /* double cast to prevent GCC warning */
+       int idx = (int)(long)data;
+       int len = 0;
+       struct dev_rcv_lists *d;
+       struct hlist_node *n;
+
+       len += snprintf(page + len, PAGE_SIZE - len,
+                       "\nreceive list '%s':\n", rx_list_name[idx]);
+
+       rcu_read_lock();
+       hlist_for_each_entry_rcu(d, n, &can_rx_dev_list, list) {
+
+               if (!hlist_empty(&d->rx[idx])) {
+                       len = can_print_recv_banner(page, len);
+                       len = can_print_rcvlist(page, len, &d->rx[idx], d->dev);
+               } else
+                       len += snprintf(page + len, PAGE_SIZE - len,
+                                       "  (%s: no entry)\n", DNAME(d->dev));
+
+               /* exit on end of buffer? */
+               if (len > PAGE_SIZE - 100)
+                       break;
+       }
+       rcu_read_unlock();
+
+       len += snprintf(page + len, PAGE_SIZE - len, "\n");
+
+       *eof = 1;
+       return len;
+}
+
+static int can_proc_read_rcvlist_sff(char *page, char **start, off_t off,
+                                    int count, int *eof, void *data)
+{
+       int len = 0;
+       struct dev_rcv_lists *d;
+       struct hlist_node *n;
+
+       /* RX_SFF */
+       len += snprintf(page + len, PAGE_SIZE - len,
+                       "\nreceive list 'rx_sff':\n");
+
+       rcu_read_lock();
+       hlist_for_each_entry_rcu(d, n, &can_rx_dev_list, list) {
+               int i, all_empty = 1;
+               /* check wether at least one list is non-empty */
+               for (i = 0; i < 0x800; i++)
+                       if (!hlist_empty(&d->rx_sff[i])) {
+                               all_empty = 0;
+                               break;
+                       }
+
+               if (!all_empty) {
+                       len = can_print_recv_banner(page, len);
+                       for (i = 0; i < 0x800; i++) {
+                               if (!hlist_empty(&d->rx_sff[i]) &&
+                                   len < PAGE_SIZE - 100)
+                                       len = can_print_rcvlist(page, len,
+                                                               &d->rx_sff[i],
+                                                               d->dev);
+                       }
+               } else
+                       len += snprintf(page + len, PAGE_SIZE - len,
+                                       "  (%s: no entry)\n", DNAME(d->dev));
+
+               /* exit on end of buffer? */
+               if (len > PAGE_SIZE - 100)
+                       break;
+       }
+       rcu_read_unlock();
+
+       len += snprintf(page + len, PAGE_SIZE - len, "\n");
+
+       *eof = 1;
+       return len;
+}
+
+/*
+ * proc utility functions
+ */
+
+static struct proc_dir_entry *can_create_proc_readentry(const char *name,
+                                                       mode_t mode,
+                                                       read_proc_t *read_proc,
+                                                       void *data)
+{
+       if (can_dir)
+               return create_proc_read_entry(name, mode, can_dir, read_proc,
+                                             data);
+       else
+               return NULL;
+}
+
+static void can_remove_proc_readentry(const char *name)
+{
+       if (can_dir)
+               remove_proc_entry(name, can_dir);
+}
+
+/*
+ * can_init_proc - create main CAN proc directory and procfs entries
+ */
+void can_init_proc(void)
+{
+       /* create /proc/net/can directory */
+       can_dir = proc_mkdir("can", init_net.proc_net);
+
+       if (!can_dir) {
+               printk(KERN_INFO "can: failed to create /proc/net/can . "
+                      "CONFIG_PROC_FS missing?\n");
+               return;
+       }
+
+       can_dir->owner = THIS_MODULE;
+
+       /* own procfs entries from the AF_CAN core */
+       pde_version     = can_create_proc_readentry(CAN_PROC_VERSION, 0644,
+                                       can_proc_read_version, NULL);
+       pde_stats       = can_create_proc_readentry(CAN_PROC_STATS, 0644,
+                                       can_proc_read_stats, NULL);
+       pde_reset_stats = can_create_proc_readentry(CAN_PROC_RESET_STATS, 0644,
+                                       can_proc_read_reset_stats, NULL);
+       pde_rcvlist_err = can_create_proc_readentry(CAN_PROC_RCVLIST_ERR, 0644,
+                                       can_proc_read_rcvlist, (void *)RX_ERR);
+       pde_rcvlist_all = can_create_proc_readentry(CAN_PROC_RCVLIST_ALL, 0644,
+                                       can_proc_read_rcvlist, (void *)RX_ALL);
+       pde_rcvlist_fil = can_create_proc_readentry(CAN_PROC_RCVLIST_FIL, 0644,
+                                       can_proc_read_rcvlist, (void *)RX_FIL);
+       pde_rcvlist_inv = can_create_proc_readentry(CAN_PROC_RCVLIST_INV, 0644,
+                                       can_proc_read_rcvlist, (void *)RX_INV);
+       pde_rcvlist_eff = can_create_proc_readentry(CAN_PROC_RCVLIST_EFF, 0644,
+                                       can_proc_read_rcvlist, (void *)RX_EFF);
+       pde_rcvlist_sff = can_create_proc_readentry(CAN_PROC_RCVLIST_SFF, 0644,
+                                       can_proc_read_rcvlist_sff, NULL);
+}
+
+/*
+ * can_remove_proc - remove procfs entries and main CAN proc directory
+ */
+void can_remove_proc(void)
+{
+       if (pde_version)
+               can_remove_proc_readentry(CAN_PROC_VERSION);
+
+       if (pde_stats)
+               can_remove_proc_readentry(CAN_PROC_STATS);
+
+       if (pde_reset_stats)
+               can_remove_proc_readentry(CAN_PROC_RESET_STATS);
+
+       if (pde_rcvlist_err)
+               can_remove_proc_readentry(CAN_PROC_RCVLIST_ERR);
+
+       if (pde_rcvlist_all)
+               can_remove_proc_readentry(CAN_PROC_RCVLIST_ALL);
+
+       if (pde_rcvlist_fil)
+               can_remove_proc_readentry(CAN_PROC_RCVLIST_FIL);
+
+       if (pde_rcvlist_inv)
+               can_remove_proc_readentry(CAN_PROC_RCVLIST_INV);
+
+       if (pde_rcvlist_eff)
+               can_remove_proc_readentry(CAN_PROC_RCVLIST_EFF);
+
+       if (pde_rcvlist_sff)
+               can_remove_proc_readentry(CAN_PROC_RCVLIST_SFF);
+
+       if (can_dir)
+               proc_net_remove(&init_net, "can");
+}