]> rtime.felk.cvut.cz Git - can-eth-gw.git/blobdiff - kernel/canethgw.c
fixed bug: kernel_recvmsg NULL pointer
[can-eth-gw.git] / kernel / canethgw.c
index a3307bfe9dc5468287367b28723ea52aee984bbc..020f79ed75b8a266738f910465c28fccc094d3d6 100644 (file)
@@ -9,27 +9,86 @@
 #include <linux/net.h>
 #include <linux/can/core.h>
 #include <linux/can.h>
+#include <net/rtnetlink.h>
+#include <net/sock.h>
 #include "canethgw.h"
+#include <linux/completion.h>
+#include <linux/mutex.h>
+#include <net/inet_common.h>
+
+/**
+ * ToDo:
+ * [ ] encapsule module - check inputs
+ * [ ] refactor - chc .h
+ * [ ] dump callback
+ * [ ] rtnl vs nl functions
+ * [ ] stop threads
+ * [ ] change listening
+ * [ ] clean exit - threads, jobs
+ */
 
 MODULE_LICENSE( "GPL" );
 
+static int  gw_udp_recv( void* data );
+static void gw_udp_send( struct can_frame* cf, struct in_addr ipaddr, u16 port );
+static int  gw_can_recv( void* data );
+static void gw_can_send( struct can_frame* cf, int ifidx );
+static void cegw_thread_start( void );
+static void cegw_thread_stop( void );
+static int cegw_thread_restart( void* arg );
+
+#define CEGW_STOPPED 0
+#define CEGW_RUNNING 1
+
 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;
+static struct socket* udp_sock = NULL;
+static struct socket* can_sock = NULL;
+/* ToDo: protect with mutex */
+static int gw_state = CEGW_STOPPED;
 
-/***********************
- *   UDP
- ***********************/
+struct can_eth_gw
+{
+       int src_if_idx;
+       struct in_addr dst_addr;
+       unsigned short dst_port;
+       struct hlist_node list;
+};
 
-int gw_udp_recv( void* data )
+struct eth_can_gw
+{
+       int dst_if_idx;
+       struct hlist_node list;
+};
+
+HLIST_HEAD( can_eth_job );
+HLIST_HEAD( eth_can_job );
+
+struct 
+{
+       struct can_filter filter;
+       int can_idx;
+       /* bind on if */
+       struct in_addr eth_addr;
+       unsigned short eth_port;
+} cegw_setting;
+
+DECLARE_COMPLETION( udp_compl );
+DECLARE_COMPLETION( can_compl );
+DECLARE_COMPLETION( udp_fin );
+DECLARE_COMPLETION( can_fin );
+DEFINE_MUTEX( cegw_setting_mutex );
+/**/
+
+static 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);
+       struct eth_can_gw* job;
+       struct hlist_node* pos;
+       int can_ifidx;
+       int recv_size;
+       struct sockaddr_in udp_addr;
 
        mh.msg_name = NULL;
        mh.msg_namelen = 0;
@@ -39,27 +98,68 @@ int gw_udp_recv( void* data )
        mh.msg_controllen = 0;
        mh.msg_flags = 0;
 
+       mutex_lock( &cegw_setting_mutex );
+       udp_addr.sin_family = AF_INET;
+       udp_addr.sin_port = htons( cegw_setting.eth_port );
+       udp_addr.sin_addr = cegw_setting.eth_addr;
+       mutex_unlock( &cegw_setting_mutex );
+
+       if( sock_create_kern( PF_INET, SOCK_DGRAM, IPPROTO_UDP, &udp_sock) != 0 )
+       {
+               printk( KERN_ERR "error: can_sock creation failed\n" );
+               return -1;
+       }
+               
+       if( kernel_bind( udp_sock, (struct sockaddr*)&udp_addr, sizeof( udp_addr ) ) != 0 ) /* ref impl ?!? */
+       {
+               printk( "error: binding failed\n" );
+               sock_release( udp_sock );
+               return -1;
+       }
+
+       printk( "gw_udp_recv is complete\n" );
+       complete_all( &udp_compl ); /* ToDo: why _all? */
+       wait_for_completion( &can_compl );
+       printk( "gw_udp_recv continues\n" );
+
        while( 1 )
        {
-               if( kthread_should_stop() ) /* up() ?, recv is blocking */
+               if( gw_state == CEGW_STOPPED )
                        break;
-               kernel_recvmsg( udp_sock, &mh, &vec, 1, sizeof(cf), 0 ); /* todo: handle error */
+               vec.iov_base = &cf;
+               vec.iov_len = sizeof(cf);
+               recv_size = kernel_recvmsg( udp_sock, &mh, &vec, 1, sizeof(cf), 0 ); /* ToDo: handle error */
+               if( recv_size == 0 )
+               {
+                       continue;
+               }
+               printk( "yes" );
                printk( "received udp msg_id:%d\n", cf.can_id );
-               gw_can_send( &cf );
+               hlist_for_each_entry_rcu( job, pos, &eth_can_job, list )
+               {
+                       rcu_read_lock(); /**/
+                       can_ifidx = job->dst_if_idx;
+                       rcu_read_unlock();
+                       /* ToDo: from filter */
+                       gw_can_send( &cf, can_ifidx );
+               }
        }
 
+       sock_release( udp_sock );
+       complete_all( &udp_fin );
+       printk( "udp terminates\n" ); 
        return 0;
 }
 
-void gw_udp_send( struct can_frame* cf )
+inline static void gw_udp_send( struct can_frame* cf, struct in_addr ipaddr, u16 port )
 {
        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;
+       addr.sin_port = htons( port );
+       addr.sin_addr = ipaddr;
        
        mh.msg_name = &addr;
        mh.msg_namelen = sizeof( addr );
@@ -73,44 +173,91 @@ void gw_udp_send( struct can_frame* cf )
        kernel_sendmsg( udp_sock, &mh, &vec, 1, sizeof( *cf ) );
 }
 
-/***********************
- *   CAN
- ***********************/
+/**/
 
-int gw_can_recv( void* data )
+static int gw_can_recv( void* data )
 {
        struct msghdr mh;
        struct kvec vec;
        struct can_frame cf;
-       
-       mh.msg_name = NULL;
-       mh.msg_namelen = 0;
+       struct sockaddr_can ca;
+       struct can_eth_gw* job;
+       struct hlist_node* pos;
+       struct in_addr eth_addr;
+       u16 eth_port;
+       int recv_size;
+       struct sockaddr_can can_addr;
+
+       mh.msg_name = &ca;
+       mh.msg_namelen = sizeof( ca );
        mh.msg_control = NULL;
        mh.msg_controllen = 0;
        mh.msg_flags = 0;
-       
-       vec.iov_base = &cf;
-       vec.iov_len = sizeof( cf );
-       
+
+       can_addr.can_family = AF_CAN;
+       can_addr.can_ifindex = 0;
+
+       if( sock_create_kern( PF_CAN, SOCK_RAW, CAN_RAW, &can_sock) != 0 )
+       {
+               printk( KERN_ERR "error: can_sock creation failed\n" );
+               return -1;
+       }
+
+       if( kernel_bind( can_sock, (struct sockaddr*) &can_addr, sizeof(can_addr) ) != 0 )
+       {
+               printk( KERN_ERR "can_sock bind failed\n" );
+               sock_release( can_sock );
+               return -1;
+       }
+
+       printk( "gw_can_recv is complete\n" );
+       complete_all( &can_compl );
+       wait_for_completion( &udp_compl );
+       printk( "gw_can_recv continues\n" );
+
        while( 1 )
        {
-               if( kthread_should_stop() ) /**/
+               if( gw_state == CEGW_STOPPED ) /**/
                        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 );
+               vec.iov_base = &cf;
+               vec.iov_len = sizeof( cf );
+
+               recv_size = kernel_recvmsg( can_sock, &mh, &vec, 1, sizeof( cf ), 0 );
+               if( recv_size == 0 )
+               {
+                       continue;
+               }
+               printk( "received can msg_id:%d, from:%d\n", cf.can_id, ca.can_ifindex );
+               hlist_for_each_entry_rcu( job, pos, &can_eth_job, list )
+               {
+                       rcu_read_lock();
+                       eth_addr = job->dst_addr;
+                       eth_port = job->dst_port;
+                       rcu_read_unlock();
+                       printk( KERN_INFO "%x\n", eth_addr.s_addr );
+                       if( job->src_if_idx == ca.can_ifindex )
+                               gw_udp_send( &cf, eth_addr, eth_port );
+               }
        }
        
+       sock_release( can_sock );
+       complete_all( &can_fin );
+       printk( "can terminates\n" );
        return 0;
 }
 
-void gw_can_send( struct can_frame* cf )
+inline static void gw_can_send( struct can_frame* cf, int ifidx )
 {
        struct msghdr mh;
-       struct kvec vec;        
+       struct kvec vec;
+       struct sockaddr_can ca =
+       {
+               .can_family = AF_CAN,
+               .can_ifindex = ifidx
+       };
        
-       mh.msg_name = NULL;
-       mh.msg_namelen = 0;
+       mh.msg_name = &ca;
+       mh.msg_namelen = sizeof( ca );
        mh.msg_control = NULL;
        mh.msg_controllen = 0;
        mh.msg_flags = 0;
@@ -121,83 +268,288 @@ void gw_can_send( struct can_frame* cf )
        kernel_sendmsg( can_sock, &mh, &vec, 1, sizeof( *cf ) );
 }
 
-/***********************
- *   module init/exit
- ***********************/
+/* NetLink */
 
-static int __init cangw_init( void )
-{      
-       struct sockaddr_in udp_addr;
-       struct sockaddr_can can_addr;
-       int ifidx = 0;
+static int cegw_create_job( struct sk_buff* skb, struct nlmsghdr* nlh, void* arg )
+{
+       struct nlattr* tb[ CGW_MAX+1 ];
+       struct can_eth_gw* cethgw = NULL;
+       struct eth_can_gw* ecangw = NULL;
+       int err = 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 )
+       /* ToDo: size check
+       if (nlmsg_len(nlh) < sizeof(*r))
+               return -EINVAL;
+       */
+
+       err = nlmsg_parse( nlh, sizeof( struct rtmsg ), tb, CGW_MAX, NULL );
+       if( err < 0 )
        {
-               printk( KERN_ERR "error: vcan0 not found\n" );
-               return -1;
+               printk( KERN_ERR "error: nlmsg_parse\n" );
+               return err;
        }
-       ifidx = can_dev->ifindex;
-       dev_put( can_dev );
-       
-       if( sock_create_kern( PF_CAN, SOCK_RAW, CAN_RAW, &can_sock) != 0 )
+
+       if( tb[CGW_CMD_INFO] == NULL )
        {
-               printk( KERN_ERR "error: can_sock creation failed\n" );
-               return -1;
+               printk( "error: bad cmd\n" );
+               return -EINVAL;
        }
-       
-       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 )
+
+       switch( *(int*)nla_data( tb[CGW_CMD_INFO] ) )
        {
-               printk( KERN_ERR "can_sock bind failed\n" );
-               return -1;
+               case CEGW_LISTEN:
+                       if( gw_state == CEGW_RUNNING )
+                       {
+                               mutex_lock( &cegw_setting_mutex );
+                               cegw_setting.eth_addr = *(struct in_addr*)nla_data( tb[CGW_LISTEN_IP] );
+                               cegw_setting.eth_port = *(u16*)nla_data( tb[CGW_LISTEN_PORT] );
+                               mutex_unlock( &cegw_setting_mutex );
+                               kthread_run( cegw_thread_restart, NULL, "canethgw" );
+                       } else
+                       {
+                               mutex_lock( &cegw_setting_mutex );
+                               cegw_setting.eth_addr = *(struct in_addr*)nla_data( tb[CGW_LISTEN_IP] );
+                               cegw_setting.eth_port = *(u16*)nla_data( tb[CGW_LISTEN_PORT] );
+                               mutex_unlock( &cegw_setting_mutex );
+                               cegw_thread_start();
+                       }
+                       break;
+               case CGW_TYPE_CAN_ETH_UDP:
+                       printk( KERN_INFO "can:%d\n", *(int*)nla_data( tb[CGW_CAN_IF] ) );
+                       printk( KERN_INFO "eth addr:%x\n", *(u32*)nla_data( tb[CGW_ETH_IP] ) );
+                       printk( KERN_INFO "eth port:%hu\n", *(u16*)nla_data( tb[CGW_ETH_PORT] ) );
+                       cethgw = kmalloc( sizeof(struct can_eth_gw), GFP_KERNEL );
+                       if( cethgw == NULL )
+                       {
+                               printk( KERN_ERR "error: kmalloc\n" );
+                               break;
+                       }
+                       cethgw->src_if_idx = *(int*)nla_data( tb[CGW_CAN_IF] );
+                       cethgw->dst_addr = *(struct in_addr*)nla_data( tb[CGW_ETH_IP] );
+                       cethgw->dst_port = *(u16*)nla_data( tb[CGW_ETH_PORT] );
+                       
+                       hlist_add_head_rcu( &cethgw->list, &can_eth_job );
+                       break;
+               case CGW_TYPE_ETH_CAN_UDP:
+                       printk( KERN_INFO "can:%d\n", *(int*)nla_data( tb[CGW_CAN_IF] ) );
+                       ecangw = kmalloc( sizeof(struct eth_can_gw), GFP_KERNEL );
+                       if( ecangw == NULL )
+                       {
+                               printk( KERN_ERR "error: kmalloc\n" );
+                               break;
+                       }
+                       ecangw->dst_if_idx = *(int*)nla_data( tb[CGW_CAN_IF] );
+                       hlist_add_head_rcu( &ecangw->list, &eth_can_job );
+                       break;
+               default:
+                       printk( "default" );
+                       /* ToDo undef operation */
+                       break;
        }
+
+       return 0;
+}
+
+static int cegw_remove_job( struct sk_buff* skb, struct nlmsghdr* nlh, void* arg )
+{
+       struct rtmsg* r;
+       struct nlattr* tb[ CGW_MAX+1 ];
+       struct hlist_node* pos,* n;
+       struct can_eth_gw* ceth;
+       struct eth_can_gw* ecan;
+
+       int err = 0;
+
+       if( nlmsg_len(nlh) < sizeof(*r) )
+               return -EINVAL;
        
-       /* 2. create udp socket and bind to it */
-       if( sock_create_kern( PF_INET, SOCK_DGRAM, IPPROTO_UDP, &udp_sock ) != 0 )
+       r = nlmsg_data( nlh );
+
+       if( r->rtm_family != AF_CAN )
+               return -EPFNOSUPPORT;
+
+       /*
+       if( r->gwtype != CGW_TYPE_CAN_ETH_UDP )
+               return -EINVAL;
+       */
+       printk( "attrsize=%d\n", nlmsg_attrlen(nlh, sizeof(struct rtmsg)) );
+
+       err = nlmsg_parse( nlh, sizeof(struct rtmsg), tb, CGW_MAX, NULL );
+       if( err != 0 )
+               return -EINVAL;
+
+       if( tb[CGW_CMD_INFO] == NULL )
+               return -EINVAL;
+       
+       if( *(int*)nla_data( tb[CGW_CMD_INFO] ) == CEGW_FLUSH )
        {
-               printk( "error: udp_sock creation failed\n" );
-               sock_release( can_sock );
-               return -1;
+               hlist_for_each_entry_safe( ceth, pos, n, &can_eth_job, list )
+               {
+                       hlist_del( &ceth->list );
+                       kfree( ceth );
+               }
+               hlist_for_each_entry_safe( ecan, pos, n, &eth_can_job, list )
+               {
+                       hlist_del( &ecan->list );
+                       kfree( ecan );
+               }
        }
-       
-       udp_addr.sin_family = AF_INET;
-       udp_addr.sin_port = htons( 10501 );
-       udp_addr.sin_addr.s_addr = INADDR_ANY;
+       //      tb[]
+       return 0;
+}
 
-       if( udp_sock->ops->bind( udp_sock, (struct sockaddr*)&udp_addr, sizeof( udp_addr ) ) != 0 ) /* ref impl ?!? */
+static int cegw_dump_job( struct sk_buff* skb, struct netlink_callback* cb )
+{
+       struct can_eth_gw* ceth;
+       struct eth_can_gw* ecan;
+       struct hlist_node* pos;
+       struct nlmsghdr* nlh;
+       int idx = 0;
+       int s_idx = cb->args[0];
+       int ifidx, type;
+       struct in_addr dst_ip; 
+       unsigned short dst_port;
+
+       rcu_read_lock();
+       hlist_for_each_entry_rcu( ecan, pos, &eth_can_job, list )
        {
-               printk( "error: binding failed\n" );
-               sock_release( udp_sock );
-               sock_release( can_sock );
-               return -1;
+
+       //      if( idx < s_idx )
+       //              goto cont1;
+
+               nlh = nlmsg_put( skb, 0, 0, 0, 0, 0 );
+
+               ifidx = ecan->dst_if_idx;
+               type = CGW_TYPE_ETH_CAN_UDP;
+               nla_put( skb, CGW_TYPE, sizeof(type), &type );
+               nlh->nlmsg_len += NLA_HDRLEN + NLA_ALIGN( sizeof(type) );
+
+               nla_put( skb, CGW_CAN_IF, sizeof(ifidx), &ifidx ); /* ToDo return */
+               nlh->nlmsg_len += NLA_HDRLEN + NLA_ALIGN( sizeof(ifidx) );
+cont1:
+               idx++;
        }
+       rcu_read_unlock();
+
+       rcu_read_lock();
+       hlist_for_each_entry_rcu( ceth, pos, &can_eth_job, list )
+       {
+       //      if( idx < s_idx )
+       //              goto cont2;
        
-       /* 3. run bridging threads */
-       eth_to_can = kthread_run( gw_udp_recv, NULL, "cangw" );
-       can_to_eth = kthread_run( gw_can_recv, NULL, "cangw" );
+               nlh = nlmsg_put( skb, 0, 0, 0, 0, 0 );
 
-       /*
-       if( sock_create_kern( AF_CAN, SOCK_RAW, CAN_RAW, &can_sock ) != 0 )
-       {s
-               printk( "error: can_sock creation failed\n" );
+               ifidx = ceth->src_if_idx;
+               type = CGW_TYPE_CAN_ETH_UDP;
+               dst_ip = ceth->dst_addr;
+               dst_port = ceth->dst_port;
+
+               nla_put( skb, CGW_TYPE, sizeof(type), &type );
+               nlh->nlmsg_len += NLA_HDRLEN + NLA_ALIGN( sizeof(type) );
+
+               nla_put( skb, CGW_CAN_IF, sizeof(ifidx), &ifidx ); /* ToDo return */
+               nlh->nlmsg_len += NLA_HDRLEN + NLA_ALIGN( sizeof(ifidx) );
+
+               nla_put( skb, CGW_ETH_IP, sizeof(dst_ip), &dst_ip ); /* ToDo return */
+               nlh->nlmsg_len += NLA_HDRLEN + NLA_ALIGN( sizeof(dst_ip) );
+
+               nla_put( skb, CGW_ETH_PORT, sizeof(dst_port), &dst_port ); /* ToDo return */
+               nlh->nlmsg_len += NLA_HDRLEN + NLA_ALIGN( sizeof(dst_port) );
+       
+               //nla_put( skb, CGW_ETH_IP, sizeof() IP_ADDR  )
+cont2:
+               idx++;
        }
-       */
+       rcu_read_unlock();
+
+       /* ToDo nlmsg_cancel */
+       cb->args[0] = idx;
+
+       return skb->len;
+}
+
+static void cegw_thread_start( void )
+{
+       gw_state = CEGW_RUNNING;
+
+       INIT_COMPLETION( udp_compl );
+       INIT_COMPLETION( can_compl );
+       INIT_COMPLETION( udp_fin );
+       INIT_COMPLETION( can_fin );
+       
+       eth_to_can = kthread_run( gw_udp_recv, NULL, "canethgw" );
+       can_to_eth = kthread_run( gw_can_recv, NULL, "canethgw" );
        
+       printk( KERN_INFO "threads are running\n" );
+}
+
+/* ToDo: stop when no threads started */
+static void cegw_thread_stop( void )
+{
+       int how = SHUT_RDWR;
+       struct sock* sk = NULL;
+
+       /* be sure sockets exist */
+       wait_for_completion( &can_compl );
+       wait_for_completion( &udp_compl );
+       gw_state = CEGW_STOPPED;
+
+       sk = can_sock->sk;
+       how++;
+       lock_sock( sk );
+       sk->sk_shutdown |= how;
+       sk->sk_state_change( sk );
+       release_sock( sk );
+
+       kernel_sock_shutdown( udp_sock, SHUT_RDWR );
+
+       /* wait for shutdown to be able to reuse port */
+       wait_for_completion( &udp_fin );
+       wait_for_completion( &can_fin );
+}
+
+static int cegw_thread_restart( void* data )
+{
+       printk( "restart\n" );
+
+       cegw_thread_stop();
+       cegw_thread_start();
+
+       return 0;
+}
+
+/***********************
+ *   module init/exit
+ ***********************/
+
+static int __init cangw_init( void )
+{
+       /* subscribe to netlink */
+       if( __rtnl_register( PF_CAN, RTM_GETROUTE, NULL, cegw_dump_job, NULL ) != 0 )
+       {
+               printk( KERN_ERR "error: rtnl_register fail\n" );
+               return -1;
+       }
+       __rtnl_register( PF_CAN, RTM_NEWROUTE, cegw_create_job, NULL, NULL );
+       __rtnl_register( PF_CAN, RTM_DELROUTE, cegw_remove_job, NULL, NULL );
+
        return 0;
 }
 
 static void __exit cangw_exit( void )
 {
-       sock_release( udp_sock );
-       sock_release( can_sock );
-       
+       if( gw_state == CEGW_RUNNING )
+       {
+               cegw_thread_stop();
+               /* ToDo: frees mem_cache?    */
+               /*       udp must not exists */
+       }
+
+       /* ToDo: unregister netlink 
+        *       free jobs          */
        printk( "cangw: exit\n" );
-       //kthread_stop( ts );
 }
 
 module_init( cangw_init );
 module_exit( cangw_exit );
+