canethgw (kernel space) first commit

Routes all from can to udp and vice versa. Listens
on udp port 10501, sends to 10502.

diff --git a/kernel/Makefile b/kernel/Makefile
new file mode 100644 (file)
index 0000000..b7a37f6
--- /dev/null
+++ b/kernel/Makefile
@@ -0,0 +1,12 @@
+obj-m += canethgw.o
+
+all:
+       make -C /lib/modules/`uname -r`/build M=`pwd`
+install:
+       make -C /lib/modules/`uname -r`/build M=`pwd` modules_install
+clean:
+       make -C /lib/modules/`uname -r`/build M=`pwd` clean
+test:
+       modprobe -r canethgw
+       modprobe canethgw
+

diff --git a/kernel/canethgw.c b/kernel/canethgw.c
new file mode 100644 (file)
index 0000000..a3307bf
--- /dev/null
+++ b/kernel/canethgw.c
@@ -0,0 +1,203 @@
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/kthread.h>
+#include <linux/sched.h>
+#include <linux/delay.h>
+#include <linux/wait.h>
+#include <linux/netdevice.h>
+#include <linux/socket.h>
+#include <linux/net.h>
+#include <linux/can/core.h>
+#include <linux/can.h>
+#include "canethgw.h"
+
+MODULE_LICENSE( "GPL" );
+
+static struct task_struct* eth_to_can, * can_to_eth;
+static struct socket* udp_sock;
+static struct socket* can_sock;
+static struct net_device* can_dev;
+
+/***********************
+ *   UDP
+ ***********************/
+
+int gw_udp_recv( void* data )
+{
+       struct can_frame cf;
+       struct kvec vec;
+       struct msghdr mh;
+
+       vec.iov_base = &cf;
+       vec.iov_len = sizeof(cf);
+
+       mh.msg_name = NULL;
+       mh.msg_namelen = 0;
+       mh.msg_iov = NULL;
+       mh.msg_iovlen = 0;
+       mh.msg_control = NULL;
+       mh.msg_controllen = 0;
+       mh.msg_flags = 0;
+
+       while( 1 )
+       {
+               if( kthread_should_stop() ) /* up() ?, recv is blocking */
+                       break;
+               kernel_recvmsg( udp_sock, &mh, &vec, 1, sizeof(cf), 0 ); /* todo: handle error */
+               printk( "received udp msg_id:%d\n", cf.can_id );
+               gw_can_send( &cf );
+       }
+
+       return 0;
+}
+
+void gw_udp_send( struct can_frame* cf )
+{
+       struct msghdr mh;
+       struct sockaddr_in addr;
+       struct kvec vec;
+       
+       addr.sin_family = AF_INET;
+       addr.sin_port = htons( 10502 );
+       addr.sin_addr.s_addr = 0x0100007f;
+       
+       mh.msg_name = &addr;
+       mh.msg_namelen = sizeof( addr );
+       mh.msg_control = NULL;
+       mh.msg_controllen = 0;
+       mh.msg_flags = 0;
+       
+       vec.iov_base = cf;
+       vec.iov_len = sizeof( *cf );
+       
+       kernel_sendmsg( udp_sock, &mh, &vec, 1, sizeof( *cf ) );
+}
+
+/***********************
+ *   CAN
+ ***********************/
+
+int gw_can_recv( void* data )
+{
+       struct msghdr mh;
+       struct kvec vec;
+       struct can_frame cf;
+       
+       mh.msg_name = NULL;
+       mh.msg_namelen = 0;
+       mh.msg_control = NULL;
+       mh.msg_controllen = 0;
+       mh.msg_flags = 0;
+       
+       vec.iov_base = &cf;
+       vec.iov_len = sizeof( cf );
+       
+       while( 1 )
+       {
+               if( kthread_should_stop() ) /**/
+                       break;
+               kernel_recvmsg( can_sock, &mh, &vec, 1, sizeof( cf ), 0 );
+               printk( "received can msg_id:%d\n", cf.can_id );
+               gw_udp_send( &cf );
+       }
+       
+       return 0;
+}
+
+void gw_can_send( struct can_frame* cf )
+{
+       struct msghdr mh;
+       struct kvec vec;        
+       
+       mh.msg_name = NULL;
+       mh.msg_namelen = 0;
+       mh.msg_control = NULL;
+       mh.msg_controllen = 0;
+       mh.msg_flags = 0;
+       
+       vec.iov_base = cf;
+       vec.iov_len = sizeof( *cf );
+       
+       kernel_sendmsg( can_sock, &mh, &vec, 1, sizeof( *cf ) );
+}
+
+/***********************
+ *   module init/exit
+ ***********************/
+
+static int __init cangw_init( void )
+{      
+       struct sockaddr_in udp_addr;
+       struct sockaddr_can can_addr;
+       int ifidx = 0;
+       
+       /* 1. create can socket and bind to it */
+       can_dev = dev_get_by_name( &init_net, "vcan0" ); /* net ns?, release counter! */
+       if( can_dev == NULL )
+       {
+               printk( KERN_ERR "error: vcan0 not found\n" );
+               return -1;
+       }
+       ifidx = can_dev->ifindex;
+       dev_put( can_dev );
+       
+       if( sock_create_kern( PF_CAN, SOCK_RAW, CAN_RAW, &can_sock) != 0 )
+       {
+               printk( KERN_ERR "error: can_sock creation failed\n" );
+               return -1;
+       }
+       
+       can_addr.can_family = AF_CAN;
+       can_addr.can_ifindex = ifidx;
+       
+       if( can_sock->ops->bind( can_sock, (struct sockaddr*) &can_addr, sizeof(can_addr) ) != 0 )
+       {
+               printk( KERN_ERR "can_sock bind failed\n" );
+               return -1;
+       }
+       
+       /* 2. create udp socket and bind to it */
+       if( sock_create_kern( PF_INET, SOCK_DGRAM, IPPROTO_UDP, &udp_sock ) != 0 )
+       {
+               printk( "error: udp_sock creation failed\n" );
+               sock_release( can_sock );
+               return -1;
+       }
+       
+       udp_addr.sin_family = AF_INET;
+       udp_addr.sin_port = htons( 10501 );
+       udp_addr.sin_addr.s_addr = INADDR_ANY;
+
+       if( udp_sock->ops->bind( udp_sock, (struct sockaddr*)&udp_addr, sizeof( udp_addr ) ) != 0 ) /* ref impl ?!? */
+       {
+               printk( "error: binding failed\n" );
+               sock_release( udp_sock );
+               sock_release( can_sock );
+               return -1;
+       }
+       
+       /* 3. run bridging threads */
+       eth_to_can = kthread_run( gw_udp_recv, NULL, "cangw" );
+       can_to_eth = kthread_run( gw_can_recv, NULL, "cangw" );
+
+       /*
+       if( sock_create_kern( AF_CAN, SOCK_RAW, CAN_RAW, &can_sock ) != 0 )
+       {s
+               printk( "error: can_sock creation failed\n" );
+       }
+       */
+       
+       return 0;
+}
+
+static void __exit cangw_exit( void )
+{
+       sock_release( udp_sock );
+       sock_release( can_sock );
+       
+       printk( "cangw: exit\n" );
+       //kthread_stop( ts );
+}
+
+module_init( cangw_init );
+module_exit( cangw_exit );

diff --git a/kernel/canethgw.h b/kernel/canethgw.h
new file mode 100644 (file)
index 0000000..2005bab
--- /dev/null
+++ b/kernel/canethgw.h
@@ -0,0 +1,5 @@
+int  gw_udp_recv( void* data );
+void gw_udp_send( struct can_frame* cf );
+int  gw_can_recv( void* data );
+void gw_can_send( struct can_frame* cf );
+