ce_gw_main.c File Reference

Control Area Network - Ethernet - Gateway - Device. More...

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/types.h>
#include <linux/skbuff.h>
#include "ce_gw_dev.h"
#include "ce_gw_netlink.h"
#include <uapi/linux/can.h>
#include <uapi/linux/if_arp.h>
#include <linux/can/core.h>
#include <linux/can/error.h>
#include <linux/slab.h>
#include <linux/if_ether.h>
#include <linux/netdevice.h>
#include <linux/crc32.h>
#include "ce_gw_main.h"
#include <net/ip.h>
#include <asm-generic/errno-base.h>
#include <asm-generic/errno.h>
#include <linux/can/dev.h>

Include dependency graph for ce_gw_main.c:

Go to the source code of this file.

static struct kmem_cache *ce_gw_job_cache	__read_mostly
static int	job_count = 1
	MODULE_DESCRIPTION ("Control Area Network - Ethernet - Gateway")
	MODULE_LICENSE ("GPL")
	MODULE_AUTHOR ("Fabian Raab <fabian.raab@tum.de>, ""Stefan Smarzly <stefan.smarzly@in.tum.de>")
	MODULE_ALIAS ("can_eth_gateway")
	HLIST_HEAD (ce_gw_job_list)
static void	list_jobs ()
	Some helper tools for testing. More...
static void	test_send_can_to_eth (struct net_device *ethdev)
	Keep these files only during development. More...
static void	test_get_vcan_netdev (void)
	Keep these files only during development. More...
static void	test_hash_list (void)
	Keep these files only during development. More...
struct hlist_head *	ce_gw_get_job_list (void)
	getter for HLIST_HEAD(ce_gw_job_list) More...
struct can_frame *	ce_gw_alloc_can_frame (void)
	allocates memory for the can frame More...
void	ce_gw_free_can_frame (struct can_frame *memory)
	frees memory allocated for can_frame More...
struct canfd_frame *	ce_gw_alloc_canfd_frame (void)
	allocates memory for a canfd frame More...
void	ce_gw_free_canfd_frame (struct canfd_frame *memory)
	frees memory allocated for can_frame More...
struct can_frame *	ce_gw_get_header_can (canid_t can_id, __u8 can_dlc, __u8 *payload)
	builds a can header in SFF (standart frame format) or EFF (extended frame formate) with the given information More...
struct canfd_frame *	ce_gw_get_header_canfd (canid_t id, __u8 len, __u8 flags, __u8 res0, __u8 res1, __u8 *data)
void	ce_gw_can2net (struct sk_buff *eth_skb, struct sk_buff *can_skb, struct net_device *eth_dev, struct net_device *can_dev, unsigned char *mac_dst, unsigned char *mac_src)
	for CE_GW_TYPE_NET: copy CAN-Frame into ethernet payload More...
struct sk_buff *	ce_gw_can2net_alloc (struct sk_buff *can_skb, struct net_device *eth_dev, struct net_device *can_dev, unsigned char *mac_dst, unsigned char *mac_src)
	for CE_GW_TYPE_NET: copy CAN-Frame into ethernet payload and allocate More...
struct sk_buff *	ce_gw_net2can_alloc (struct sk_buff *eth_skb, struct net_device *can_dev)
	for CE_GW_TYPE_NET: Copy the can-frame from eth_skb to a new can skb. More...
void	ce_gw_canfd2net (struct sk_buff *eth_skb, struct sk_buff *can_skb, struct net_device *eth_dev, struct net_device *can_dev, unsigned char *mac_dst, unsigned char *mac_src)
	for CE_GW_TYPE_NET: copy CAN-Frame into ethernet payload More...
struct sk_buff *	ce_gw_canfd2net_alloc (struct sk_buff *can_skb, struct net_device *eth_dev, struct net_device *can_dev, unsigned char *mac_dst, unsigned char *mac_src)
	for CE_GW_TYPE_NET: copy canfd-Frame into ethernet payload and allocate More...
struct sk_buff *	ce_gw_net2canfd_alloc (struct sk_buff *eth_skb, struct net_device *can_dev, struct net_device *eth_dev)
	for CE_GW_TYPE_NET: Copy the canfd-frame from eth_skb to a new can skb. More...
struct sk_buff *	ce_gw_can_to_eth (unsigned char *dest, unsigned char *source, __be16 type, struct sk_buff *can_buffer, struct net_device *dev)
	converts sk buffer including can frame into sk buffer including ethernet_frame More...
struct sk_buff *	ce_gw_canfd_to_eth (unsigned char *dest, unsigned char *source, __be16 type, struct sk_buff *canfd_skb, struct net_device *dev)
	converts sk buffer including canfd frame into sk buffer including ethernet frame More...
struct sk_buff *	ce_gw_eth_to_can (canid_t id, struct sk_buff *eth_buff, struct net_device *dev)
	converst sk_buffer including an ethernet frame to sk_buffer including a can_frame More...
struct sk_buff *	ce_gw_eth_to_canfd (canid_t id, __u8 flags, __u8 res0, __u8 res1, struct sk_buff *eth_skb, struct net_device *dev)
	converst sk buffer including an ethernet frame to sk buffer including a canfd frame More...
static __u8	ce_gw_get_ip_version (void *payload)
	Reads the first 4 bytes of IP-Header and detects the version. More...
void	ce_gw_can_rcv (struct sk_buff *can_skb, void *data)
	The gateway function for incoming CAN frames Receive CAN frame –> process –> send to ETH dev (skbuffer, struct receiver->data) More...
void	ce_gw_eth_rcv (struct sk_buff *eth_skb, void *data)
	The gateway function for incoming ETH frames Receive skb from ETH dev –> process –> send to CAN bus. More...
static int	ce_gw_register_can_src (struct ce_gw_job *gwj)
static void	ce_gw_unregister_can_src (struct ce_gw_job *gwj)
static int	ce_gw_register_eth_src (struct ce_gw_job *gwj)
static void	ce_gw_unregister_eth_src (struct ce_gw_job *gwj)
int	ce_gw_create_route (int src_ifindex, int dst_ifindex, enum ce_gw_type rt_type, u32 flags)
int	ce_gw_remove_route (u32 id)
static int __init	ce_gw_init_module (void)
	Will be automatic called at module init. More...
static void __exit	ce_gw_cleanup (void)
	Will be automatically called on module remove. More...
	module_init (ce_gw_init_module)
	module_exit (ce_gw_cleanup)

Detailed Description

Control Area Network - Ethernet - Gateway - Device.

Author

Stefan Smarzly (stefa.nosp@m.n.sm.nosp@m.arzly.nosp@m.@in..nosp@m.tum.d.nosp@m.e)

Fabian Raab (fabia.nosp@m.n.ra.nosp@m.ab@tu.nosp@m.m.de)

Date

May, 2013

Copyright

GNU Public License v3 or higher

Definition in file ce_gw_main.c.

Function Documentation

int ce_gw_create_route	(	int	src_ifindex,
		int	dst_ifindex,
		enum ce_gw_type	rt_type,
		u32	flags
	)

Definition at line 916 of file ce_gw_main.c.

References ce_gw_job::can_rcv_filter, ce_gw_has_min_mtu(), ce_gw_is_registered_dev(), ce_gw_register_can_src(), ce_gw_register_eth_src(), ce_gw_job::dev, ce_gw_job::dropped_frames, ce_gw_job::dst, ce_gw_job::flags, ce_gw_job::handled_frames, ce_gw_job::id, job_count, ce_gw_job::list, ce_gw_job::src, and ce_gw_job::type.

Referenced by ce_gw_netlink_add().

{
    int err = 0;

    struct ce_gw_job *gwj;
    gwj = kmem_cache_alloc(ce_gw_job_cache, GFP_KERNEL);

    gwj->id = job_count++;
    gwj->handled_frames = 0;
    gwj->dropped_frames = 0;

    err = -ENODEV;
    gwj->src.dev = dev_get_by_index(&init_net, src_ifindex);
    gwj->dst.dev = dev_get_by_index(&init_net, dst_ifindex);
    if (!gwj->src.dev || !gwj->dst.dev)
        goto clean_exit;

    if (ce_gw_has_min_mtu(gwj->src.dev, rt_type, flags) == false ||
        ce_gw_has_min_mtu(gwj->dst.dev, rt_type, flags) == false) {
        err = -EOPNOTSUPP;
        goto clean_exit;
    }

    gwj->type = rt_type;
    gwj->flags = flags;

    /* TEST: pre-filled values */
    gwj->can_rcv_filter.can_id = 0x42A;
    gwj->can_rcv_filter.can_mask = 0; /* allow all frames */

    /*
     * Depending on routing direction: register at source device
     */
    if (gwj->src.dev->type == ARPHRD_CAN &&
        ce_gw_is_registered_dev(gwj->dst.dev) == 0) {
        /*      && gwj->dst.dev->type == ARPHRD_ETHER) {*/
        /* CAN source --> ETH destination (cegw virtual dev) */
        err = ce_gw_register_can_src(gwj);
    } else if (ce_gw_is_registered_dev(gwj->src.dev) == 0 &&
               gwj->dst.dev->type == ARPHRD_CAN) {
        /* ETH source (cegw virtual dev) --> CAN destination */
        err = ce_gw_register_eth_src(gwj);
    } else {
        /* Undefined routing setup */
        goto clean_exit;
    }

    if (!err)
        hlist_add_head_rcu(&gwj->list, &ce_gw_job_list);

clean_exit:
    if (err) {
        printk(KERN_ERR "ce_gw: Src or dst device not found or "
               "not compatible (CAN<->CEGW ETH), exit.\n");
        if (gwj->src.dev)
            dev_put(gwj->src.dev);
        if (gwj->dst.dev)
            dev_put(gwj->dst.dev);
        kmem_cache_free(ce_gw_job_cache, gwj);
    }

    return err;
}

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struct canfd_frame* ce_gw_get_header_canfd ( canid_t  id, __u8  len, __u8  flags, __u8  res0, __u8  res1, __u8 *  data  )

read

Definition at line 201 of file ce_gw_main.c.

References ce_gw_alloc_canfd_frame().

                                                  {
    struct canfd_frame *canfd = ce_gw_alloc_canfd_frame();
    if (canfd == NULL) {
        printk (KERN_ERR "ce_gw_main.c: kmalloc failed in function"
                "ce_gw_get_header_canfd\n");
        return NULL;
    }

    canfd->can_id = id;
    canfd->len = len;
    canfd->flags = flags;
    canfd->__res0 = res0;
    canfd->__res1 = res1;
    *(u64 *)canfd->data = *(u64 *)data;

    return canfd;
}

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struct hlist_head * ce_gw_get_job_list ( void  )

read

getter for HLIST_HEAD(ce_gw_job_list)

Returns

Pointer to ce_gw_job_list.

Definition at line 157 of file ce_gw_main.c.

Referenced by ce_gw_netlink_list().

                                            {
    return &ce_gw_job_list;
}

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static int ce_gw_register_can_src ( struct ce_gw_job *  gwj )

inlinestatic

Definition at line 888 of file ce_gw_main.c.

References ce_gw_job::can_rcv_filter, ce_gw_can_rcv(), ce_gw_job::dev, and ce_gw_job::src.

Referenced by ce_gw_create_route().

{
    return can_rx_register(gwj->src.dev, gwj->can_rcv_filter.can_id,
                           gwj->can_rcv_filter.can_mask, ce_gw_can_rcv,
                           gwj, "ce_gw");
}

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static int ce_gw_register_eth_src ( struct ce_gw_job *  gwj )

inlinestatic

Definition at line 903 of file ce_gw_main.c.

References ce_gw_dev_job_src_add().

Referenced by ce_gw_create_route().

{
    ce_gw_dev_job_src_add(gwj);
    return 0;
}

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int ce_gw_remove_route

(

u32

id

)

Definition at line 982 of file ce_gw_main.c.

References ce_gw_job::can_rcv_filter, ce_gw_unregister_can_src(), ce_gw_unregister_eth_src(), ce_gw_job::dev, ce_gw_job::dst, ce_gw_job::id, ce_gw_job::list, and ce_gw_job::src.

Referenced by ce_gw_cleanup(), ce_gw_dev_unregister(), and ce_gw_netlink_del().

{
    pr_info("ce_gw: unregister CAN ETH GW routes\n");
    struct ce_gw_job *gwj = NULL;
    struct hlist_node *n, *nx;

    hlist_for_each_entry_safe(gwj, n, nx, &ce_gw_job_list, list) {
        if (gwj->id != id && id)
            continue;

        pr_debug("Removing routing src device: %s, id %x, mask %x\n",
                 gwj->src.dev->name, gwj->can_rcv_filter.can_id,
                 gwj->can_rcv_filter.can_mask);
        hlist_del(&gwj->list);
        /* TODO: Unregister destination device (only for cegw eth) */
        if (gwj->src.dev->type == ARPHRD_CAN)
            ce_gw_unregister_can_src(gwj);
        else
            ce_gw_unregister_eth_src(gwj);
        dev_put(gwj->src.dev);
        dev_put(gwj->dst.dev);
        kmem_cache_free(ce_gw_job_cache, gwj);
    }

    return 0; /* TODO: error, when no suitable entry was found */
}

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static void ce_gw_unregister_can_src ( struct ce_gw_job *  gwj )

inlinestatic

Definition at line 895 of file ce_gw_main.c.

References ce_gw_job::can_rcv_filter, ce_gw_can_rcv(), ce_gw_job::dev, and ce_gw_job::src.

Referenced by ce_gw_remove_route().

{
    return can_rx_unregister(gwj->src.dev, gwj->can_rcv_filter.can_id,
                             gwj->can_rcv_filter.can_mask,
                             ce_gw_can_rcv, gwj);
}

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static void ce_gw_unregister_eth_src ( struct ce_gw_job *  gwj )

inlinestatic

Definition at line 910 of file ce_gw_main.c.

References ce_gw_dev_job_remove().

Referenced by ce_gw_remove_route().

{
    ce_gw_dev_job_remove(gwj);
}

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HLIST_HEAD

(

ce_gw_job_list

)

static void list_jobs ( void  )

static

Some helper tools for testing.

Definition at line 1069 of file ce_gw_main.c.

References ce_gw_job::dev, ce_gw_job::dst, ce_gw_job::id, and ce_gw_job::src.

Referenced by ce_gw_init_module().

{
    struct ce_gw_job *gwj = NULL;
    struct hlist_node *n, *nx;

    pr_info("Routing jobs\n"
            "------------\n");
    hlist_for_each_entry_safe(gwj, n, nx, &ce_gw_job_list, list) {
        pr_info("ID: %i, input dev: %s, output dev: %s\n",
                gwj->id, gwj->src.dev->name, gwj->dst.dev->name);
    }
    if (!gwj)
        pr_info("No ce_gw routing jobs found!\n");
}

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MODULE_ALIAS

(

"can_eth_gateway"

)

MODULE_AUTHOR	(	"Fabian Raab <fabian.raab@tum.de>	,
		""Stefan Smarzly< stefan.smarzly @in.tum.de >"
	)

MODULE_DESCRIPTION

(

"Control Area Network - Ethernet - Gateway"

)

 _______________________________________________________
|                                                       |
|       CAN Ethernet Gateway Kernel Module (ce_gw)      |
|_______________________________________________________|
|                                                       |
|           Ethernet Frame    +----------------------+  |  CAN Frame
|           +-----o---------->|CAN - Ethernet Gateway|<-+-------o----+
|           |                 |     ce_gw_main.c     |  |            |
|           |                 +----------------------+  |            v
|           v                                           |       +----------+
| +--------------------+                                |       |CAN Device|
| |virtual Ethernet dev|                                |       |  can.c   |
| |('cegw#' Interface) |         +---------------+      |       +----------+
| |    ce_gw_dev.c     |         |Netlink Server |      |            ^
| +--------------------+         |ce_gw_netlink.c|      |            |
|           ^                    +---------------+      |            v
|           |                            ^              |       +----------+
|___________|____________________________|______________|       |CAN Driver|
            |                            o Netlink Frame        +----------+
            v            Kernelspace     |                           ^
          +----+       __________________|_____________              |
          | OS |         Userspace       |                           v
          +----+                         v                       +-------+
                                +------------------+             |CAN NIC|
                                |  Netlink Client  |             +-------+
                                |    netlink.c     |
                                |(can-eth-gw-utils)|
                                +------------------+

Diagramm witch shows the relation and Packet transmission between the components of this kernel module (ce_gw) and others of the OS.

    +------------------+             /--------------------------------------\
    |   <<Ethernet>>   |             |ce_gw_job has Ethernet as dest and CAN|
    |struct net_device |             |as source OR has Ethernet as src and  |
    +------------------+             |CAN as dst. hlist_node annotations are|
+-->|       ....       |             |Members of the structs where the arrow|
|   +------------------+             |points to. The hlist structs are not  |
|           |                        |directly represented here and are so  |
|           |void *priv              |simplyfied.                           |
|           |                        \--------------------------------------/
|           v
|   +---------------------+        struct hlist_head ce_gw_job_list
|   |struct ce_gw_job_info|                       |
|   +---------------------+                       |
|   |                     |    struct hlist_node  |
|   +---------------------+        list         \ |
|                 | | struct                     \|
|         struct  | |hlist_head                   |     +------------------+
|       hlist_head| | job_src                     |     |     <<CAN>>      |
|         job_dst | |                             |     |struct net_device |
|                 | |\                            |     +------------------+
|                 | | struct hlist_node           |     |       ....       |
|                 | |/   list_dev                 |     +------------------+
|                 | /                             |               ^
|                 |/|                             |0...*          |
| struct          | |       0...*                 v               | struct
|net_device       | +--------->+----------------------+           |net_device
| *dev            +----------->|  struct ce_gw_job    |           | *dev
|                        0...* +----------------------+           |
|        +-------------+       |struct rcu_head rcu   |      +-------------+
|        |   union     |       |u32 id                |      |   union     |
+--------+-------------+       |enum ce_gw_type type  |      +-------------+
         |             |<>-----|u32 flags             |----<>|             |
         +-------------+  dst/ |u32 handled_frames    | src/ +-------------+
                          src  |u32 dropped_frames    | dst
                               |union { struct can_   |
                               |filter can_rcv_filter}|
                               +----------------------+

This is an UML Klass Diagramm witch shows the main routing Management lists.

module_exit

(

ce_gw_cleanup

)

module_init

(

ce_gw_init_module

)

MODULE_LICENSE

(

"GPL"

)

static void test_get_vcan_netdev ( void  )

static

Keep these files only during development.

Definition at line 1100 of file ce_gw_main.c.

{
    struct net_device *dev;
    char vcandev[] = "vcan1";

    pr_debug("cegw testing: Try finding vcan0 net_device.\n");
    /* use dev_get_by_index for ifindex */
    if ((dev = __dev_get_by_name(&init_net, vcandev)) == NULL) {
        pr_debug("cegw testing: %s not found.\n", vcandev);
        return;
    }
    /* Getting infos from vcan device */
    pr_debug("cegw testing: %s found!\n", vcandev);
    pr_debug("type: %i, ifindex: %i\n", dev->type, dev->ifindex);

}

static void test_hash_list ( void  )

static

Keep these files only during development.

Definition at line 1120 of file ce_gw_main.c.

References ce_gw_job::dropped_frames, and ce_gw_job::list.

{
    struct ce_gw_job *gwj1 = kmem_cache_alloc(ce_gw_job_cache, GFP_KERNEL);
    gwj1->dropped_frames = 25;
    struct ce_gw_job *gwj2 = kmem_cache_alloc(ce_gw_job_cache, GFP_KERNEL);
    gwj2->dropped_frames = 250;
    /* dynamic alloc, dangerous when out of scope*/
    struct ce_gw_job gwj3 = {
        .dropped_frames = 555
    };

    hlist_add_head(&gwj1->list, &ce_gw_job_list);
    hlist_add_head(&gwj2->list, &ce_gw_job_list);
    hlist_add_head(&gwj3.list, &ce_gw_job_list);

    struct ce_gw_job *gwj = NULL;
    struct hlist_node *n, *nx;

    hlist_for_each_entry(gwj, n, &ce_gw_job_list, list) {
        pr_debug("cegw hashtest: List entry %i\n", gwj->dropped_frames);
    }

}

static void test_send_can_to_eth ( struct net_device *  ethdev )

static

Keep these files only during development.

Definition at line 1087 of file ce_gw_main.c.

{
    struct sk_buff *skb;

    skb = netdev_alloc_skb(ethdev, sizeof(struct ethhdr) +
                           sizeof(struct can_frame));
    skb_reserve(skb, sizeof(struct ethhdr));

}

Variable Documentation

struct kmem_cache* ce_gw_job_cache __read_mostly

static

Definition at line 148 of file ce_gw_main.c.

int job_count = 1

static

Definition at line 149 of file ce_gw_main.c.

Referenced by ce_gw_create_route().